[Objective] The aim of this study is to isolate Chlorella vulgaris(chlorella)and extract its genomic DNA.[Method] Both the dilution method and drip method were employed to isolate chlorella from lake water samples;the...[Objective] The aim of this study is to isolate Chlorella vulgaris(chlorella)and extract its genomic DNA.[Method] Both the dilution method and drip method were employed to isolate chlorella from lake water samples;the conditions for culturing chlorella were optimized and its genomic DNA was extracted by improved CTAB method and SDS method.[Result] The proper conditions for chlorella culture were as following:temperature 20-25 ℃,illumination 4.39-5.86 W/m2 and rotational speed 100-150r/min;improved CTAB method was suitable for extracting genomic DNA from chlorella.[Conclusion] The study is helpful to study the chlorella at molecular level and promote the exploitation and utilization of chlorella resources.展开更多
[Objective] This study aimed at comparing the four extraction methods of genomic DNA from Clematis fasciculiflora Franch and determining the optimal extraction method for extracting the genomic DNA from Clematis fasci...[Objective] This study aimed at comparing the four extraction methods of genomic DNA from Clematis fasciculiflora Franch and determining the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch.[Method] Leavies of Clematis fasciculiflora Franch were used as materials for comparing the purity and concentration of extracted DNA and extracting time among the four extraction methods of genomic DNA including improved CTAB method Ⅰ,improved CTAB method Ⅱ,improved CTAB method Ⅲ and improved SDS method.[Result] The four extraction methods could all be successfully used for extracting the genomic DNA from Clematis fasciculiflora Franch.The purity of genomic DNA was the highest using improved CTAB method Ⅰ,with the longest extracting time;while the concentration of genomic DNA was the maximum using the improved SDS method,with the shortest extracting time and relatively low purity;the extracting time of improved CTAB method Ⅲ was the shortest.[Conclusion] This study had established the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch and supported for the further research using molecular biological methods.展开更多
[Objective] The study was to explore the most effective and feasible method for sugarcane stalks RNA extraction.[Method] SDS extraction method,kit extraction method and GHCL extraction method were used to extract the ...[Objective] The study was to explore the most effective and feasible method for sugarcane stalks RNA extraction.[Method] SDS extraction method,kit extraction method and GHCL extraction method were used to extract the sugarcane RNA in stalks,and the quality of the extracted RNA was compared.[Result] RNA extracted by kit extraction method had a high-yield,the bands were clear and RNA had a good integrity,there was no significant degradation of RNA,and the OD260 nm/OD280 nm value was closed to 2.0.[Conclusion] Kit extraction method was the effectively method to extract sugarcane RNA,and this study had provided a theoretical basis for the molecular biology study of sugarcane.展开更多
[Objective] This study was to find out a quick,simple,and low-cost method for the extraction of sorghum genomic DNA.[Method] Four plant genomic DNA extraction methods based on CTAB,including liquid nitrogen grinding m...[Objective] This study was to find out a quick,simple,and low-cost method for the extraction of sorghum genomic DNA.[Method] Four plant genomic DNA extraction methods based on CTAB,including liquid nitrogen grinding method（method I）,buffer grinding method（method II）,drying grinding method（method III）and directly grinding method（method IV）,were used to extract the sorghum genomic DNA from leaves;further the quantity and quality of the yielded DNA were detected by gel electrophoresis,SSR-PCR and SRAP-PCR.[Result] These four methods performed no remarkable difference in DNA product.The method I and method II produced DNA with higher purity and better integrity,which,especially from method I,is effective for SRAP-PCR and SSR-PCR.While the DNA extracted via method III and method IV had less integrality and lower purity,and only effective in SSR-PCR.[Conclusion] Enough amount of sorghum genomic DNA to perform tens of PCR could be quickly extracted using all these four methods.The DNA obtained via method I and method II had a broader application spectrum（SRAP,RAPD,ISSR and SSR）than that via method III and method IV which is only proper for PCR targeting small DNA fragments（SSR）.展开更多
To rapidly obtain high-quality genomic DNA from Chenopodium quinoa Willd, the genomic DAN in different tissues （leaves, stems and roots） of Chenopodi- um quinoa Willd was extracted by modified CTAB method, SDS metho...To rapidly obtain high-quality genomic DNA from Chenopodium quinoa Willd, the genomic DAN in different tissues （leaves, stems and roots） of Chenopodi- um quinoa Willd was extracted by modified CTAB method, SDS method and high- salt Iow-pH method, respectively. The quality and yield of extracted DNA was deter- mined using agarose gel electrophoresis and UV spectrophotometry. At the same time, the PCR-SSR and SSCP molecular detection was also performed. The results showed that the gel test strips, without obvious decomposition, of all the extraction methods were relatively obvious; the genomic DNA yield extracted by modified CTAB method was highest, followed by that by SDS method, and the genomic DNA extracted by high-salt Iow-pH method was lowest： the genomic DNA yields extracted by different methods from Chenopodium quinoa Wiltd leaves were all high- er than those from roots and stems; the quality of Chenopodium quinoa Willd ge- nomic DNA extracted by modified CTAB method and high-salt Iow-pH method was better, and polyphenols, polysaccharides and other impurities were removed more completely. The PCR-SSR and SSCP detection results showed that the genomic DNA extracted by different methods from different tissues of Chenopodium quinoa Willd all could be better amplified, and high-quality strips could be obtained. So the Chenopodium quinoa Willd genomic DNA extracted by the three methods all can be used for subsequent molecular biology research.展开更多
[Objective] The aim of this study was to compare three RNA extraction methods and thus find out the suitable one for isolating intact and high quality total RNA from Pinus bungeana.[Method] Employing three extraction ...[Objective] The aim of this study was to compare three RNA extraction methods and thus find out the suitable one for isolating intact and high quality total RNA from Pinus bungeana.[Method] Employing three extraction methods of Trizol,RNeasy Mini Kit,LiCl precipitation,total RNAs of P.bungeana were extracted from pine leaf samples,and their integrity and purity were detected via agarose gel electrophoresis and spectrophotometry for a comparative study.[Result] Among the three extraction methods,LiCl precipitation method demonstrated higher yield and better integrity of total extracted RNA,with OD260/OD280 ratio between 1.8-2.0 and clear 28 S and 18 S bands in electrophoresis pattern.[Conclusion] LiCl precipitation method could be used to extract highly pure and intact total RNA from P.bungeana.展开更多
Endoscopic submucosal dissection(ESD)has been developed as a treatment for superficial gastrointestinal neoplasms,which can achieve en bloc resection regardless of the lesion size.However,ESD is technically difficult ...Endoscopic submucosal dissection(ESD)has been developed as a treatment for superficial gastrointestinal neoplasms,which can achieve en bloc resection regardless of the lesion size.However,ESD is technically difficult because endoscopists cannot bring their hand into the gastrointestinal tract,unlike surgeons in regular surgery.It is difficult to obtain sufficient tension in the dissection plane and a good field of vision.Therefore,ESD is associated with a long procedure time and a high risk of adverse events in comparison with endoscopic mucosal resection.Traction methods have been developed to provide sufficient tension for the dissection plane and a good field of vision during the ESD procedure.However,traction direction is limited in most traction methods,resulting in insufficient effect in some cases.Although traction direction is considered important,there have been few investigations of its effect.In the first half of this review,important traction methods are discussed,including traction direction.In second half,appropriate traction methods for each organ are considered.Other important considerations for traction method,such as ability to adjust traction strength,interference between traction device and endoscope,and the need for specialized devices are also discussed.展开更多
Endoscopic mucosal resection(EMR) is problematic with regard to en bloc and curable resection rates.Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissecti...Endoscopic mucosal resection(EMR) is problematic with regard to en bloc and curable resection rates.Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissection(ESD), which has overcome some EMR problems, and has become the standard treatment for gastrointestinal tumors. However, ESD is technically difficult. Procedure time is longer and complications such as intraoperative perforation and bleeding occur more frequently than in EMR. Recently various traction methods have been introduced to facilitate ESD procedures, such as clip with line, external forceps, clip and snare, internal traction, double scope, and magnetic anchor. Each method must be used appropriately according to the anatomical characteristics. In this review we discuss recently proposed traction methods for ESD based on the characteristics of various anatomical sites.展开更多
Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
Endoscopic submucosal dissection(ESD)procedure has a longer procedure time and higher perforation rate than endoscopic mucosal resection owing to technical complications,including a poor field of vision and inadequate...Endoscopic submucosal dissection(ESD)procedure has a longer procedure time and higher perforation rate than endoscopic mucosal resection owing to technical complications,including a poor field of vision and inadequate tension for the submucosal dissection plane.Various traction devices were developed to secure the visual field and provide adequate tension for the dissection plane.Two randomized controlled trials demonstrated that traction devices reduce colorectal ESD procedure time compared with conventional ESD(C-ESD),but they had limitations,including a single-center fashion.The CONNECT-C trial was the first multicenter randomized controlled trial comparing the C-ESD and traction device-assisted ESD(T-ESD)for colorectal tumors.In the T-ESD,one of the device-assisted traction methods(S-O clip,clip-with-line,and clip pulley)was chosen according to the operator’s discretion.The median ESD procedure time(primary endpoint)was not significantly different between C-ESD and T-ESD.For lesions≥30 mm in diameter or in cases treated by nonexpert operators,the median ESD procedure time tended to be shorter in T-ESD than in C-ESD.Although T-ESD did not reduce ESD procedure time,the CONNECT-C trial results suggest that T-ESD is effective for larger lesions and nonexpert operators in colorectal ESD.Compared with esophageal and gastric ESD,colorectal ESD has some difficulties,including poor endoscope maneuverability,which may be associated with prolonged ESD procedure time.T-ESD may not effectively improve these issues,but a balloon-assisted endoscope and underwater ESD may be promising options and these methods can be combined with T-ESD.展开更多
Jujube is rich in nutrients and functional active ingredients. For example,jujube flavonoids have significant anti-oxidation,anticancer,antibacterial and anti-inflammatory functions. This paper elaborated the advances...Jujube is rich in nutrients and functional active ingredients. For example,jujube flavonoids have significant anti-oxidation,anticancer,antibacterial and anti-inflammatory functions. This paper elaborated the advances in the studies about the extraction methods,purification methods,antioxidant properties,stability and antibacterial effects of jujube flavonoids,in order to provide a certain reference for the study of jujube flavonoids.展开更多
We applied the projection and contraction method to nonlinear complementarity problem (NCP). Moveover, we proposed an inexact implicit method for (NCP) and proved the convergence.
Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly ...Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses.展开更多
The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytica...The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well.展开更多
Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vi...Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.展开更多
The identification of the traction acting on a portion of the surface of an anisotropic solid is very important in structural health monitoring and optimal design of structures. The traction can be determined using in...The identification of the traction acting on a portion of the surface of an anisotropic solid is very important in structural health monitoring and optimal design of structures. The traction can be determined using inverse methods in which displacement or strain measurements are taken at several points on the body. This paper presents an inverse method based on the method of fundamental solutions for the traction identification problem in two-dimensional anisotropic elasticity. The method of fundamental solutions is an efficient boundary-type meshless method widely used for analyzing various problems. Since the problem is linear, the sensitivity analysis is simply performed by solving the corresponding direct problem several times with different loads. The effects of important parameters such as the number of measurement data, the position of the measurement points, the amount of measurement error, and the type of measurement, i.e., displacement or strain, on the results are also investigated. The results obtained show that the presented inverse method is suitable for the problem of traction identification. It can be concluded from the results that the use of strain measurements in the inverse analysis leads to more accurate results than the use of displacement measurements. It is also found that measurement points closer to the boundary with unknown traction provide more reliable solutions. Additionally, it is found that increasing the number of measurement points increases the accuracy of the inverse solution. However, in cases with a large number of measurement points, further increasing the number of measurement data has little effect on the results.展开更多
Molecular microbiological methods, such as competetive PCR, real-time PCR, denaturing gradient gel electrophoresis (DGGE) and large-scale parallel-pyrosequencing, require the extraction of sufficient quantity of high ...Molecular microbiological methods, such as competetive PCR, real-time PCR, denaturing gradient gel electrophoresis (DGGE) and large-scale parallel-pyrosequencing, require the extraction of sufficient quantity of high quality DNA from microbiologically and chemically complex matrices. Due to difficulties in the field to standardize/select the optimum DNA preservation-extraction methods in view of laboratories differences, this article attempts to present a straight-forward mathematical framework for comparing some of the most commonly used methods. To this end, as a case study, the problem of selecting an optimum sample preservation-DNA extraction strategy for obtaining total bacterial DNA from swine feces was considered. Two sample preservation methods (liquid nitrogen and RNAlater?) and seven extraction techniques were paired and compared under six quantitative DNA analysis criteria: yield of extraction, purity of extracted DNA (A260/280 and A 260/230 ratios), duration of extraction, degradation degree of DNA, and cost. From a practical point of view, it is unlikely that a single sample preservation-DNA extraction strategy can be optimum for all selected criteria. Hence, a systematic multi-criteria decision-making (MCDM) approach was used to compare the methods. As a result, the ZR Fecal DNA MiniPrepTM DNA extraction kit for samples preserved either with liquid nitrogen or RNAlater? were identified as potential optimum solutions for obtaining total bacterial DNA from swine feces. Considering the need for practicality for in situ applications, we would recommend liquid nitrogen as sample preservation method, along with the ZR Fecal DNA MiniPrepTM kit. Total bacterial DNA obtained by this strategy can be suitable for downstream PCR-based DNA analyses of swine feces.展开更多
Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillat...Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction （HDE） and solvent-free microwave extraction （SME） oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME （56.7%） and HDIE （60.0%） oils were significantly different （P〈0.05） from those of sea water （63.3%） and chloramphenicol （15.0%）. Larva lethality was different significantly （P〈0.05） between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration （LC50） of the oils was 〉 1000 mg/ml recommended as an index for non-toxicity which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.展开更多
[ Objective ] The paper was to screen the better extraction method for herbicidal active substances of Eupatorium adenophorum. [ Method ] Three com- mon extraction methods, Soxhlet extraction, ultrasonic extraction an...[ Objective ] The paper was to screen the better extraction method for herbicidal active substances of Eupatorium adenophorum. [ Method ] Three com- mon extraction methods, Soxhlet extraction, ultrasonic extraction and conventional extraction method, were used to prepare E. adenophorum extracts, and the herblcidal activity of E. adenophorum extracts extracted by 3 methods was studied by seed germination method. [ Result] The extraction rate of Soxhlet extraction was the highest of （22.54 ± 0.48 ）%, and the herbicidal activities of E. adenophorum extracted by Soxhlet extraction was relatively stronger. [ Conclusion] Soxhlet extraction was the better extraction method for herbicidal active substances of E. adenophorum.展开更多
Different traction devices that can provide a visual field and attain appropriate tension at the dissection plane during endoscopic submucosal dissection(ESD)have been developed.Clip-with-line(CWL)is a classic tractio...Different traction devices that can provide a visual field and attain appropriate tension at the dissection plane during endoscopic submucosal dissection(ESD)have been developed.Clip-with-line(CWL)is a classic traction device that can offer per-oral traction toward the direction where the line is drawn.A multicenter randomized controlled trial(CONNECT-E trial)comparing the conventional ESD and CWL-assisted ESD(CWL-ESD)for large esophageal tumors was conducted in Japan.This study showed that CWL-ESD was associated with a shorter procedure time(defined as the time from initiating submucosal injection to completing tumor removal)without increasing the risk of adverse events.Multivariate analysis revealed that whole-circumferential lesion and abdominal esophageal lesion were independent risk factors for technical difficulties,which were defined as a procedure time of>120 min,perforation,piecemeal resection,inadvertent incision(any accidental incision caused by the electrosurgical knife within the marked area),or handover to another operator.Therefore,techniques other than CWL should be considered for these lesions.Several studies have shown the usefulness of endoscopic submucosal tunnel dissection(ESTD)for such lesions.A randomized controlled trial conducted at five Chinese institutions showed that compared with the conventional ESD,ESTD had a significantly reduced median procedure time for lesions covering≥1/2 of the esophageal circumference.In addition,a propensity score matching analysis conducted at a single Chinese institution showed that compared with the conventional ESD,ESTD had a shorter mean resection time for lesions at the esophagogastric junction.With the appropriate use of CWL-ESD and ESTD,esophageal ESD can be performed more efficiently and safely.Moreover,the combination of these two methods may be effective.展开更多
基金Supported by the High-level Talents Start-up Fund of Shihezi University(07002-500002061401)~~
文摘[Objective] The aim of this study is to isolate Chlorella vulgaris(chlorella)and extract its genomic DNA.[Method] Both the dilution method and drip method were employed to isolate chlorella from lake water samples;the conditions for culturing chlorella were optimized and its genomic DNA was extracted by improved CTAB method and SDS method.[Result] The proper conditions for chlorella culture were as following:temperature 20-25 ℃,illumination 4.39-5.86 W/m2 and rotational speed 100-150r/min;improved CTAB method was suitable for extracting genomic DNA from chlorella.[Conclusion] The study is helpful to study the chlorella at molecular level and promote the exploitation and utilization of chlorella resources.
基金Supported by Applied Basic Research Project of Yunnan Province(2010ZC089)the948Project of National Forestry Bureau(2008-4-11)+1 种基金Sharing Platform Project of Provincial and Ministerial Key Subject,Key Laboratory and School Laboratory of Provincial Colleges and Universities in Yunnan ProvinceScience and Technology Innovation Fund of Southwest Forestry University~~
文摘[Objective] This study aimed at comparing the four extraction methods of genomic DNA from Clematis fasciculiflora Franch and determining the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch.[Method] Leavies of Clematis fasciculiflora Franch were used as materials for comparing the purity and concentration of extracted DNA and extracting time among the four extraction methods of genomic DNA including improved CTAB method Ⅰ,improved CTAB method Ⅱ,improved CTAB method Ⅲ and improved SDS method.[Result] The four extraction methods could all be successfully used for extracting the genomic DNA from Clematis fasciculiflora Franch.The purity of genomic DNA was the highest using improved CTAB method Ⅰ,with the longest extracting time;while the concentration of genomic DNA was the maximum using the improved SDS method,with the shortest extracting time and relatively low purity;the extracting time of improved CTAB method Ⅲ was the shortest.[Conclusion] This study had established the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch and supported for the further research using molecular biological methods.
基金Supported by Schools Fund of Hainan University(hd09xm62 )Higher Education Research Foundation Program of Hainan Provin-cial Education Department (Hjkj2010-17)Technology Foundation Program of South China Tropical Agricultural University(Rnd0710)~~
文摘[Objective] The study was to explore the most effective and feasible method for sugarcane stalks RNA extraction.[Method] SDS extraction method,kit extraction method and GHCL extraction method were used to extract the sugarcane RNA in stalks,and the quality of the extracted RNA was compared.[Result] RNA extracted by kit extraction method had a high-yield,the bands were clear and RNA had a good integrity,there was no significant degradation of RNA,and the OD260 nm/OD280 nm value was closed to 2.0.[Conclusion] Kit extraction method was the effectively method to extract sugarcane RNA,and this study had provided a theoretical basis for the molecular biology study of sugarcane.
基金Supported by Key Technology R&D Program of Tianjin(10ZCKFNC00100)National Key Technology R&D Program(2007BAD42B03)~~
文摘[Objective] This study was to find out a quick,simple,and low-cost method for the extraction of sorghum genomic DNA.[Method] Four plant genomic DNA extraction methods based on CTAB,including liquid nitrogen grinding method（method I）,buffer grinding method（method II）,drying grinding method（method III）and directly grinding method（method IV）,were used to extract the sorghum genomic DNA from leaves;further the quantity and quality of the yielded DNA were detected by gel electrophoresis,SSR-PCR and SRAP-PCR.[Result] These four methods performed no remarkable difference in DNA product.The method I and method II produced DNA with higher purity and better integrity,which,especially from method I,is effective for SRAP-PCR and SSR-PCR.While the DNA extracted via method III and method IV had less integrality and lower purity,and only effective in SSR-PCR.[Conclusion] Enough amount of sorghum genomic DNA to perform tens of PCR could be quickly extracted using all these four methods.The DNA obtained via method I and method II had a broader application spectrum（SRAP,RAPD,ISSR and SSR）than that via method III and method IV which is only proper for PCR targeting small DNA fragments（SSR）.
基金Supported by National Natural Science Foundation of China(31301372)Key Project of Science and Technology Plan of Zhejiang Province(2011C12030)Innovation Training Project of Zhejiang Agriculture and Forestry University(201301004)~~
文摘To rapidly obtain high-quality genomic DNA from Chenopodium quinoa Willd, the genomic DAN in different tissues （leaves, stems and roots） of Chenopodi- um quinoa Willd was extracted by modified CTAB method, SDS method and high- salt Iow-pH method, respectively. The quality and yield of extracted DNA was deter- mined using agarose gel electrophoresis and UV spectrophotometry. At the same time, the PCR-SSR and SSCP molecular detection was also performed. The results showed that the gel test strips, without obvious decomposition, of all the extraction methods were relatively obvious; the genomic DNA yield extracted by modified CTAB method was highest, followed by that by SDS method, and the genomic DNA extracted by high-salt Iow-pH method was lowest： the genomic DNA yields extracted by different methods from Chenopodium quinoa Wiltd leaves were all high- er than those from roots and stems; the quality of Chenopodium quinoa Willd ge- nomic DNA extracted by modified CTAB method and high-salt Iow-pH method was better, and polyphenols, polysaccharides and other impurities were removed more completely. The PCR-SSR and SSCP detection results showed that the genomic DNA extracted by different methods from different tissues of Chenopodium quinoa Willd all could be better amplified, and high-quality strips could be obtained. So the Chenopodium quinoa Willd genomic DNA extracted by the three methods all can be used for subsequent molecular biology research.
基金Supported by National Program on Key Basic Research Project(2009CB119204)~~
文摘[Objective] The aim of this study was to compare three RNA extraction methods and thus find out the suitable one for isolating intact and high quality total RNA from Pinus bungeana.[Method] Employing three extraction methods of Trizol,RNeasy Mini Kit,LiCl precipitation,total RNAs of P.bungeana were extracted from pine leaf samples,and their integrity and purity were detected via agarose gel electrophoresis and spectrophotometry for a comparative study.[Result] Among the three extraction methods,LiCl precipitation method demonstrated higher yield and better integrity of total extracted RNA,with OD260/OD280 ratio between 1.8-2.0 and clear 28 S and 18 S bands in electrophoresis pattern.[Conclusion] LiCl precipitation method could be used to extract highly pure and intact total RNA from P.bungeana.
文摘Endoscopic submucosal dissection(ESD)has been developed as a treatment for superficial gastrointestinal neoplasms,which can achieve en bloc resection regardless of the lesion size.However,ESD is technically difficult because endoscopists cannot bring their hand into the gastrointestinal tract,unlike surgeons in regular surgery.It is difficult to obtain sufficient tension in the dissection plane and a good field of vision.Therefore,ESD is associated with a long procedure time and a high risk of adverse events in comparison with endoscopic mucosal resection.Traction methods have been developed to provide sufficient tension for the dissection plane and a good field of vision during the ESD procedure.However,traction direction is limited in most traction methods,resulting in insufficient effect in some cases.Although traction direction is considered important,there have been few investigations of its effect.In the first half of this review,important traction methods are discussed,including traction direction.In second half,appropriate traction methods for each organ are considered.Other important considerations for traction method,such as ability to adjust traction strength,interference between traction device and endoscope,and the need for specialized devices are also discussed.
文摘Endoscopic mucosal resection(EMR) is problematic with regard to en bloc and curable resection rates.Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissection(ESD), which has overcome some EMR problems, and has become the standard treatment for gastrointestinal tumors. However, ESD is technically difficult. Procedure time is longer and complications such as intraoperative perforation and bleeding occur more frequently than in EMR. Recently various traction methods have been introduced to facilitate ESD procedures, such as clip with line, external forceps, clip and snare, internal traction, double scope, and magnetic anchor. Each method must be used appropriately according to the anatomical characteristics. In this review we discuss recently proposed traction methods for ESD based on the characteristics of various anatomical sites.
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
文摘Endoscopic submucosal dissection(ESD)procedure has a longer procedure time and higher perforation rate than endoscopic mucosal resection owing to technical complications,including a poor field of vision and inadequate tension for the submucosal dissection plane.Various traction devices were developed to secure the visual field and provide adequate tension for the dissection plane.Two randomized controlled trials demonstrated that traction devices reduce colorectal ESD procedure time compared with conventional ESD(C-ESD),but they had limitations,including a single-center fashion.The CONNECT-C trial was the first multicenter randomized controlled trial comparing the C-ESD and traction device-assisted ESD(T-ESD)for colorectal tumors.In the T-ESD,one of the device-assisted traction methods(S-O clip,clip-with-line,and clip pulley)was chosen according to the operator’s discretion.The median ESD procedure time(primary endpoint)was not significantly different between C-ESD and T-ESD.For lesions≥30 mm in diameter or in cases treated by nonexpert operators,the median ESD procedure time tended to be shorter in T-ESD than in C-ESD.Although T-ESD did not reduce ESD procedure time,the CONNECT-C trial results suggest that T-ESD is effective for larger lesions and nonexpert operators in colorectal ESD.Compared with esophageal and gastric ESD,colorectal ESD has some difficulties,including poor endoscope maneuverability,which may be associated with prolonged ESD procedure time.T-ESD may not effectively improve these issues,but a balloon-assisted endoscope and underwater ESD may be promising options and these methods can be combined with T-ESD.
基金Supported by Science and Technology Planning Project of Cangzhou City,Hebei Province(162204001)
文摘Jujube is rich in nutrients and functional active ingredients. For example,jujube flavonoids have significant anti-oxidation,anticancer,antibacterial and anti-inflammatory functions. This paper elaborated the advances in the studies about the extraction methods,purification methods,antioxidant properties,stability and antibacterial effects of jujube flavonoids,in order to provide a certain reference for the study of jujube flavonoids.
基金Supported by the National Natural Science Foundation of China (No. 202001036)
文摘We applied the projection and contraction method to nonlinear complementarity problem (NCP). Moveover, we proposed an inexact implicit method for (NCP) and proved the convergence.
文摘Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses.
基金supported by the National Natural Science Foundation of China(12172023).
文摘The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well.
基金funded by the National Natural Science Foundation of China(No.41962016)the Natural Science Foundation of NingXia(Nos.2023AAC02023,2023A1218,and 2021AAC02006).
文摘Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.
基金funded by Vice Chancellor of Research at Shiraz University(grant 3GFU2M1820).
文摘The identification of the traction acting on a portion of the surface of an anisotropic solid is very important in structural health monitoring and optimal design of structures. The traction can be determined using inverse methods in which displacement or strain measurements are taken at several points on the body. This paper presents an inverse method based on the method of fundamental solutions for the traction identification problem in two-dimensional anisotropic elasticity. The method of fundamental solutions is an efficient boundary-type meshless method widely used for analyzing various problems. Since the problem is linear, the sensitivity analysis is simply performed by solving the corresponding direct problem several times with different loads. The effects of important parameters such as the number of measurement data, the position of the measurement points, the amount of measurement error, and the type of measurement, i.e., displacement or strain, on the results are also investigated. The results obtained show that the presented inverse method is suitable for the problem of traction identification. It can be concluded from the results that the use of strain measurements in the inverse analysis leads to more accurate results than the use of displacement measurements. It is also found that measurement points closer to the boundary with unknown traction provide more reliable solutions. Additionally, it is found that increasing the number of measurement points increases the accuracy of the inverse solution. However, in cases with a large number of measurement points, further increasing the number of measurement data has little effect on the results.
文摘Molecular microbiological methods, such as competetive PCR, real-time PCR, denaturing gradient gel electrophoresis (DGGE) and large-scale parallel-pyrosequencing, require the extraction of sufficient quantity of high quality DNA from microbiologically and chemically complex matrices. Due to difficulties in the field to standardize/select the optimum DNA preservation-extraction methods in view of laboratories differences, this article attempts to present a straight-forward mathematical framework for comparing some of the most commonly used methods. To this end, as a case study, the problem of selecting an optimum sample preservation-DNA extraction strategy for obtaining total bacterial DNA from swine feces was considered. Two sample preservation methods (liquid nitrogen and RNAlater?) and seven extraction techniques were paired and compared under six quantitative DNA analysis criteria: yield of extraction, purity of extracted DNA (A260/280 and A 260/230 ratios), duration of extraction, degradation degree of DNA, and cost. From a practical point of view, it is unlikely that a single sample preservation-DNA extraction strategy can be optimum for all selected criteria. Hence, a systematic multi-criteria decision-making (MCDM) approach was used to compare the methods. As a result, the ZR Fecal DNA MiniPrepTM DNA extraction kit for samples preserved either with liquid nitrogen or RNAlater? were identified as potential optimum solutions for obtaining total bacterial DNA from swine feces. Considering the need for practicality for in situ applications, we would recommend liquid nitrogen as sample preservation method, along with the ZR Fecal DNA MiniPrepTM kit. Total bacterial DNA obtained by this strategy can be suitable for downstream PCR-based DNA analyses of swine feces.
文摘Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction （HDE） and solvent-free microwave extraction （SME） oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME （56.7%） and HDIE （60.0%） oils were significantly different （P〈0.05） from those of sea water （63.3%） and chloramphenicol （15.0%）. Larva lethality was different significantly （P〈0.05） between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration （LC50） of the oils was 〉 1000 mg/ml recommended as an index for non-toxicity which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.
基金Supported by Youth Fund Project of Yunnan Agricultural University
文摘[ Objective ] The paper was to screen the better extraction method for herbicidal active substances of Eupatorium adenophorum. [ Method ] Three com- mon extraction methods, Soxhlet extraction, ultrasonic extraction and conventional extraction method, were used to prepare E. adenophorum extracts, and the herblcidal activity of E. adenophorum extracts extracted by 3 methods was studied by seed germination method. [ Result] The extraction rate of Soxhlet extraction was the highest of （22.54 ± 0.48 ）%, and the herbicidal activities of E. adenophorum extracted by Soxhlet extraction was relatively stronger. [ Conclusion] Soxhlet extraction was the better extraction method for herbicidal active substances of E. adenophorum.
文摘Different traction devices that can provide a visual field and attain appropriate tension at the dissection plane during endoscopic submucosal dissection(ESD)have been developed.Clip-with-line(CWL)is a classic traction device that can offer per-oral traction toward the direction where the line is drawn.A multicenter randomized controlled trial(CONNECT-E trial)comparing the conventional ESD and CWL-assisted ESD(CWL-ESD)for large esophageal tumors was conducted in Japan.This study showed that CWL-ESD was associated with a shorter procedure time(defined as the time from initiating submucosal injection to completing tumor removal)without increasing the risk of adverse events.Multivariate analysis revealed that whole-circumferential lesion and abdominal esophageal lesion were independent risk factors for technical difficulties,which were defined as a procedure time of>120 min,perforation,piecemeal resection,inadvertent incision(any accidental incision caused by the electrosurgical knife within the marked area),or handover to another operator.Therefore,techniques other than CWL should be considered for these lesions.Several studies have shown the usefulness of endoscopic submucosal tunnel dissection(ESTD)for such lesions.A randomized controlled trial conducted at five Chinese institutions showed that compared with the conventional ESD,ESTD had a significantly reduced median procedure time for lesions covering≥1/2 of the esophageal circumference.In addition,a propensity score matching analysis conducted at a single Chinese institution showed that compared with the conventional ESD,ESTD had a shorter mean resection time for lesions at the esophagogastric junction.With the appropriate use of CWL-ESD and ESTD,esophageal ESD can be performed more efficiently and safely.Moreover,the combination of these two methods may be effective.
