Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to es...Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to establish a rapid detection method of Pss for the diagnosis and prevention of this disease.In order to robust and accurately diagnose the rice bacterial leaf brown spot disease in the field and laboratory,an assay system for the Pss was developed in this study,and the specific sequence of hrcN was used as the target,based on loop-mediated isothermal amplification(LAMP).The best detection system was MgSO 48 mmol·L^(-1),Bst DNA polymerase 8 U,dNTP 1.4 mmol·L^(-1),the ratio of internal and outer primers was 2:1,the reaction temperature was 63℃,the reaction time was 45 min,and the lowest sensitivity was 104 CFU·mL^(-1).This results provided an accurate and robust method for laboratory and field diagnosis of bacterial leaf brown spot disease of rice.展开更多
The integrity of the chromosomes for two WIL2-derived lymphoblastoid cell lines (TK6 and WTK1) in the presence and absence of ionizing radiation was analyzed by Multiplex Ligation-Dependent Probe Amplification (MLPA)....The integrity of the chromosomes for two WIL2-derived lymphoblastoid cell lines (TK6 and WTK1) in the presence and absence of ionizing radiation was analyzed by Multiplex Ligation-Dependent Probe Amplification (MLPA). The TK6 cell line has the native p53 tumor-suppressor gene, whereas WTK1 cells contain a p53 mutation. Each cell line was isolated pre- and post-irradiation (2 and 3 Gy) and analyzed by MLPA. The impact of irradiation on these two cell lines was investigated using probes that target specific regions on chromosomes associated with subtelomeric regions. Results indicate that WTK1 and TK6 are impacted differently after irradiation, and that each cell line presents its own unique MLPA profile. The most notable differences are the appearance of a number of probes in the post-irradiated MLPA profile that are not present in the controls, and two unique probe signals only seen in WTK1 cells. These results build on our previous studies that indicate how different human cell lines can be affected by radiation in significantly different ways depending on the presence or absence of wild type p53.展开更多
Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainl...Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainly focuses on blast center distance but neglects the amplification effect of blasting vibration waves by terraced terrain,from which the calculated blasting vibration velocities are smaller than the actual values,affecting the safety of the project.To address this issue,our model introduces the influences of slope and time into Sadowski formula to measure safety through blast vibration displacement.In the northern section of the open-pit quartz mine in Jinchang City,Gansu Province,China,the data of a continuous blasting slope project are referred to.Our findings reveal a noticeable vibration amplification effect during blasting when a multi-stage slope platform undergoes a sudden cross-sectional change near the upper overhanging surface.The amplification vibration coefficient increases with height,while vibration waves within rocks decrease from bottom to top.Conversely,platforms without distinct crosssectional changes exhibit no pronounced amplification during blasting.In addition,the vibration intensity decreases with distance as the rock height difference change propagates.The results obtained by the proposed blast vibration displacement equation incorporating slope shape influence closely agree with real-world scenarios.According to Pearson correlation coefficient(PPMCC)analysis,the average accuracy rate of our model is 88.84%,which exceeds the conventional Sadowski formula(46.92%).展开更多
BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related mortality worldwide.Mesenchymal-epithelial transition factor(MET)gene participates in multiple tumor ...BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related mortality worldwide.Mesenchymal-epithelial transition factor(MET)gene participates in multiple tumor biology and shows clinical potential for pharmacological manipulation in tumor treatment.MET amplification has been reported in CRC,but data are very limited.Investigating pathological values of MET in CRC may provide new therapeutic and genetic screening options in future clinical practice.AIM To determine the pathological significance of MET amplification in CRC and to propose a feasible screening strategy.METHODS A number of 205 newly diagnosed CRC patients undergoing surgical resection without any preoperative therapy at Shenzhen Cancer Hospital of Chinese Academy of Medical Sciences were recruited.All patients were without RAS/RAF mutation or microsatellite instability-high.MET amplification and c-MET protein expression were analyzed using fluorescence in situ hybridization(FISH)and immunohistochemistry(IHC),respectively.Correlations between MET aberration and pathological features were detected using the chi-squared test.Progression free survival(PFS)during the two-year follow-up was detected using the Kaplan-Meier method and log rank test.The results of MET FISH and IHC were com pared using one-way ANOVA.RESULTS Polysomy-induced MET amplification was observed in 14.4%of cases,and focal MET amplification was not detected.Polysomy-induced MET amplification was associated with a higher frequency of lymph node metastasis(LNM)(P<0.001)and higher tumor budding grade(P=0.02).In the survival analysis,significant difference was detected between patients with amplified-and non-amplified MET in a two-year follow-up after the first diagnosis(P=0.001).C-MET scores of 0,1+,2+,and 3+were observed in 1.4%,24.9%,54.7%,and 19.0%of tumors,respectively.C-MET overexpression correlated with higher frequency of LNM(P=0.002),but no significant difference of PFS was detected between patients with different protein levels.In terms of concordance between MET FISH and IHC results,MET copy number showed no difference in c-MET IHC 0/1+(3.35±0.18),2+(3.29±0.11)and 3+(3.58±0.22)cohorts,and the MET-to-CEP7 ratio showed no difference in three groups(1.09±0.02,1.10±0.01,and 1.09±0.03).CONCLUSION In CRC,focal MET amplification was a rare event.Polysomy-induced MET amplification correlated with adverse pathological characteristics and poor prognosis.IHC was a poor screening tool for MET amplification.展开更多
Grovers algorithm is a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The Amplitude Amplification in Grovers algorithm is T = O(N). This paper intr...Grovers algorithm is a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The Amplitude Amplification in Grovers algorithm is T = O(N). This paper introduces two new algorithms for Amplitude Amplification in Grovers algorithm with a time complexity of T = O(logN), aiming to improve efficiency in quantum computing. The difference between Grovers algorithm and our first algorithm is that the Amplitude Amplification ratio in Grovers algorithm is an arithmetic series and ours, a geometric one. Because our Amplitude Amplification ratios converge much faster, the time complexity is improved significantly. In our second algorithm, we introduced a new concept, Amplitude Transfer where the marked state is transferred to a new set of qubits such that the new qubit state is an eigenstate of measurable variables. When the new qubit quantum state is measured, with high probability, the correct solution will be obtained.展开更多
This article analyzes and discusses the working principle and problems encountered by various servo amplification devices used in the on-site continuous adjustment system,analyzes and discusses the application of the ...This article analyzes and discusses the working principle and problems encountered by various servo amplification devices used in the on-site continuous adjustment system,analyzes and discusses the application of the servo mechanism,and analyzes the mechanism of the servo device's implementation of the"positioning"func-tion on the control device.Intended to guide the continuous adjustment process in controlling the function/accuracy of actuator equipment and application debugging,ensuring the safe and stable operation of production equipment and facilities.展开更多
Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leadin...Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.展开更多
Pectobacterium carotovorum is the causal agent of bacterial soft rot in a wide range of vegetable host species.Once P.carotovorum infects the plant,the spread of the disease is difficult to control.In this study,a rap...Pectobacterium carotovorum is the causal agent of bacterial soft rot in a wide range of vegetable host species.Once P.carotovorum infects the plant,the spread of the disease is difficult to control.In this study,a rapid and sensitive method based on loop-mediated isothermal amplification(LAMP)was developed for detecting P.carotovorum in celery with soft rot using a primer set designed from the pmrA conserved sequence of P.carotovorum.The specificity of the LAMP primer set for P.carotovorum was extensively validated on both P.carotovorum strains and nontarget strains.The sensitivity was 1 pg of P.carotovorum genomic DNA,which demonstrated 10 times more sensitive than the conventional PCR assay.LAMP was also used to detect P.carotovorum in bacterial suspension.The lowest detection concentration was 104 CFU·mL^−1.In addition,a LAMP assay,in conjunction with a crude DNA extraction method,was successfully performed on P.carotovorum-infected samples derived from both artificially and naturally infected plants.In summary,the LAMP assay established in this study constitutes a simple,sensitive,and rapid method for the detection of P.carotovorum,and has potential application in the control of celery soft rot disease through early detection.展开更多
[ Objective ] This study was to investigate the creditability of applying loop-mediated isothermal amplification method (LAMP) to detect Staphylococcus aureus in dairy products. [ Methods] The primers for heat resis...[ Objective ] This study was to investigate the creditability of applying loop-mediated isothermal amplification method (LAMP) to detect Staphylococcus aureus in dairy products. [ Methods] The primers for heat resistant nuclease gene (nuc) of Staphylococcus aureus were designed for establishing the LAMP method for rapidly detecting Staphylococcus aureus. [ Results ] The results of LAMP detection on Staphylococcus aureus in various dairy products were completely identical with that by bacterial isolation test; meanwhile it has a high specificity and a 10-fold sensitivity over the hemi-nested PCR. [ Conclusion] LAMP can be used for the detection of Staphylococcus aureus in dairy products.展开更多
A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for human enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) infection was further evaluated. The one step reaction was perfor...A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for human enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) infection was further evaluated. The one step reaction was performed in a single tube at 65?C for 45 min for EV71 and 35 min for CVA16. The detection limits of RT-LAMP assays for both EV71 and CVA16 were 0.1 of a 50% tissue culture infective dose (TCID50) per reaction, based on 10—Fold dilutions of a titrated EV71 or CVA16 strain. The specific assay showed there were no cross-reactions with Coxsackievirus A (CVA) viruses (CVA 2, 4, 5, 7, 9, 10, 14, and 25), Coxsackievirus B (CVB) viruses (CVB 1, 2, 3, 4, and 5) or ECHO viruses (ECHO 3, 6, 11, and 19). In parallel with commercial quantitative real-time polymerase chain reaction (qRT-PCR) diagnostic kits for EV71 and CVA16, the RT-LAMP assay was evaluated with 515 clinical specimens, the results showed the RT-LAMP assay and the qRT-PCR assay were in complete agreement for 513/515 (99.6%) of the specimens. Two samples with discrepant results from two methods were further verified by nested reverse transcription polymerase chain reaction (nRT-PCR) assay and sequencing to be true positives for CVA16. In conclusion, RT-LAMP assay is demonstrated to be a sensitive and specific assay and have a great potential for the rapid and visual screening of EV71 and CVA16 in China, especially in those resource-limited hospitals and rural clinics of provincial and municipal regions.展开更多
A loop-mediated isothermal amplification (LAMP) assay was designed and evaluated for rapid de- tection of the toxic microalgae Alexandrium catenella and A. minutum, which can produce paralytic shellfish poisoning (...A loop-mediated isothermal amplification (LAMP) assay was designed and evaluated for rapid de- tection of the toxic microalgae Alexandrium catenella and A. minutum, which can produce paralytic shellfish poisoning (PSP). Two sets of four specific primers targeting these two species were derived from the sequence of internal transcribed spacer (ITS) of ribosomal DNA. The method worked well in less than an hour under isothermal conditions of 65℃. LAMP specificity was validated in closely related algae as a comparison, suggesting the strict specificity of the LAMP primers. Two visual inspection approaches were feasible to interpret the positive or negative results. The detection lim- its of A. catenella and A. minutum samples using the LAMP assay were found to be 5.6 and 4.5 pg DNA, respectively. The sensitivity of this LAMP assay was 10 or 100-fold higher than Polymerase Chain Reaction (PCR) method in detecting the two microalgae. These characteristics of species specificity, sensitivity, and rapidity suggest that this method has the potentiality in the monitoring of red tide caused by A. catenella and A. minutum.展开更多
Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.hist...Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.histolytica hemolysin gene HLY6.Genomic DNA of E.histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions.Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.Results:Positive LAMP reactions turned turbid while negative ones remained clear.Upon addition of a fluorescent dye,all positive reactions turned green while the negative control remained orange under ambient light After elecrophoresis in 1.5% agarose gels,a ladder of multiple bands of different sizes can be oliserved in positive samples while no bands were detected in the negative control.The sensitivity of the assay was found to be S parasites per reaction which corresponds to approximately 1S.8 ng/μL DNA.The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species,Entamoeba dispar. and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.Conclusions:The I.AMP assay we have developed enables the detection of E.histolytica with rapidity and ease,therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.展开更多
Vibrio vulnificus is an estuarine bacterial pathogen for human.The rapid,specific and sensitive detection of V.vulnificus is urgently needed for early disease diagnosis and timely treatment of V.vulnificus infection.I...Vibrio vulnificus is an estuarine bacterial pathogen for human.The rapid,specific and sensitive detection of V.vulnificus is urgently needed for early disease diagnosis and timely treatment of V.vulnificus infection.In the study,a loop-mediated isothermal amplification(LAMP) technique was developed for V.vulnificus detection with a set of primers,composed of two out primers and two inner primers targeted to vvh A gene.The optimal amplification temperature was 63°C and the reaction only took 35 min.The amplification products could not only be detected by agarose gel electrophoresis with ladder-like pattern bands,but also could be visualized using calcein with naked eye directly.Forty-five strains were tested for the specificity of LAMP assay,and all the V.vulnificus strains were identified correctly while other strains were negative results.The sensitive of the new LAMP assay was 100-fold more sensitive than the conventional PCR.Meanwhile,all the V.vulnificus strains were detected correctly in spiked,clinical and environmental samples by the new LAMP assay.Compared with other well-known techniques,the new LAMP assay targeted to vvh A gene was extremely rapid,simple,sensitive and specific for V.vulnificus identification.展开更多
A set of universal loop-mediated isothermal amplification (LAMP) primers targeting the flo gene was designed to detect Borrelia burgdorferi sensu lato (B. burgdorferi s.I.) in human samples. The sensitivity of LAM...A set of universal loop-mediated isothermal amplification (LAMP) primers targeting the flo gene was designed to detect Borrelia burgdorferi sensu lato (B. burgdorferi s.I.) in human samples. The sensitivity of LAMP was 20 copies/reaction, and the assay did not detect false positives among 11 other related bacteria. A positive LAMP result was obtained for 9 of the 24 confirmed cases and for 12 of 94 suspected cases. The positive rate of LAMP was the same as that of nested PCR. The LAMP is a useful diagnostic method that can be developed for rapid detection of B. burgdorferi s.I. in human sera. Combination of the LAMP and nested PCR was more sensitive for detecting B. burgdorferi s.I. in human serum samples.展开更多
Viral hemorrhagic septicemia virus(VHSV) and marine birnavirus(MABV) are the causative pathogens for some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economi...Viral hemorrhagic septicemia virus(VHSV) and marine birnavirus(MABV) are the causative pathogens for some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of pathogen infection. The loop-mediated isothermal amplification(LAMP) of DNA is currently one of the most commonly used molecular diagnostic tools, as it is simple, quick, and easy to amplify target DNA under isothermal conditions. In the present study, a novel and highly specific LAMP assay for the sensitive and rapid detection of VHSV and MABV infection in fish was developed. Using a set of synthesized primers matching a specific region of the genome, the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficient detection of VHSV and MABV infection in the wild fish, Paralichthys olivaceus. Our results demonstrate the simplicity and convenience of this method for the detection of viral infection in aquatic organisms.展开更多
A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for rapid visual detection of Murray valley encephalitis virus (MVEV) infection. The reaction was performed in...A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for rapid visual detection of Murray valley encephalitis virus (MVEV) infection. The reaction was performed in one step in a single tube at 63 ~C for 60 min with the addition of the hydroxynaphthol blue (HNB) dye prior to amplification. The detection limit of the RT-LAMP assay was 100 copies per reaction based on 10-fold dilutions of in vitro transcribed RNA derived from a synthetic MVEV DNA template. No cross-reaction was observed with other encephalitis-associated viruses. The assay was further evaluated using spiked cerebrospinal fluid sample with pseudotype virus containing the NS5 gene of MVEV.展开更多
Plague caused by Yersinia pestis is one of the infectious diseases subject to the International Health Regulations (IHR). Permanent monitoring of the focal plague areas is mandatory in order to enable prompt control m...Plague caused by Yersinia pestis is one of the infectious diseases subject to the International Health Regulations (IHR). Permanent monitoring of the focal plague areas is mandatory in order to enable prompt control measures to prevent the spread of the disease. Therefore, the availability of efficient diagnosis tests is of paramount importance. Here, we describe a loop-mediated isothermal amplification (LAMP)-based procedure for rapid Y. pestis detection. We constructed a set of LAMP primers, which were used in assays to establish the reaction conditions that would lead to the quick visualization of the results by evaluating the test tube with the naked eye. The primers were specifically designed to target the caf1 gene located on pFra/Tox (pMT), a prototypical plasmid of Y. pestis. The LAMP procedure was performed at 65°C for 45 min in a water bath and allowed for the detection of at least 10 pg of bacterial DNA. Due to its simplicity, specificity, sensitivity and rapidity, the LAMP technique is an additional tool that may be implemented in routine plague diagnoses, especially in emergencies.展开更多
Loop-mediated isothermal ampliifcation (LAMP) is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chin...Loop-mediated isothermal ampliifcation (LAMP) is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chinese giant salamander ranavirus(CGSRV) was developed from culture isolates and clinical samples. The LAMP assay was developed by designing one set of four speciifc primers, targeting the major capsid protein (MCP) gene of CGSRV. Reaction time and temperature were optimal for 40 min at 62°C. The developed LAMP assay is speciifc and highly sensitive for CGSRV detection, the detection limit could reach about 5 copies of cloned viral genomic fragments. The sensitivity of the LAMP assay was about 1000 and 10-fold higher than that of both conventional and nested PCR, respectively. The LAMP ampliifcation produces a typical ladder-like pattern of products on an agarose gel that can be visually inspected after addition of ethidium bromide. The LAMP assay was evaluated further with clinical samples, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for the detection of CGSRV.展开更多
Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method, which amplifies DNA with high specificity, sensitivity, rapidity and efficiency under isothermal conditions using a set of fo...Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method, which amplifies DNA with high specificity, sensitivity, rapidity and efficiency under isothermal conditions using a set of four specially designed primers and a Bst DNA polymerase with strand displacement activity. The basic principle, characteristics, development of LAMP and its applications are summarized in this article.展开更多
When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses....When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses.Even test samples without any pretreatment can be used as template.This feature suggests that LAMP is superior to PCR in developing point-of-care test strategies.In this study,using Stx1 gene from E.coli as model,we verified that viable cells,dead cells and extracellular DNA could function as template in the LAMP assay.In the incubation at 63℃,viable bacteria in the LAMP reaction mixture lysed completely within 2 min,providing DNA template for nucleic acid amplification.The Stx1 gene in diluted culture medium,spiked tap water,spiked seawater and real seawater all could be detected,with or without the step of DNA extraction.We found that the complex substances in real sample(e.g.natural seawater)exhibited considerable inhibitory effect on the sensitivity of the LAMP assay.These outcomes are meaningful for building a point-of-care strategy by employing the LAMP assay for environmental monitoring,bio-resource surveys,food safety,etc.in particular those based on environmental DNA.展开更多
基金Supported by the Natural Science Foundation of Heilongjiang Province(Topic C2017032)Heilongjiang Province Applied Technology Research and Development Program(Topic GA19B104)the National Key Research and Development Program(Topic 2018YFD0300105)。
文摘Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to establish a rapid detection method of Pss for the diagnosis and prevention of this disease.In order to robust and accurately diagnose the rice bacterial leaf brown spot disease in the field and laboratory,an assay system for the Pss was developed in this study,and the specific sequence of hrcN was used as the target,based on loop-mediated isothermal amplification(LAMP).The best detection system was MgSO 48 mmol·L^(-1),Bst DNA polymerase 8 U,dNTP 1.4 mmol·L^(-1),the ratio of internal and outer primers was 2:1,the reaction temperature was 63℃,the reaction time was 45 min,and the lowest sensitivity was 104 CFU·mL^(-1).This results provided an accurate and robust method for laboratory and field diagnosis of bacterial leaf brown spot disease of rice.
文摘The integrity of the chromosomes for two WIL2-derived lymphoblastoid cell lines (TK6 and WTK1) in the presence and absence of ionizing radiation was analyzed by Multiplex Ligation-Dependent Probe Amplification (MLPA). The TK6 cell line has the native p53 tumor-suppressor gene, whereas WTK1 cells contain a p53 mutation. Each cell line was isolated pre- and post-irradiation (2 and 3 Gy) and analyzed by MLPA. The impact of irradiation on these two cell lines was investigated using probes that target specific regions on chromosomes associated with subtelomeric regions. Results indicate that WTK1 and TK6 are impacted differently after irradiation, and that each cell line presents its own unique MLPA profile. The most notable differences are the appearance of a number of probes in the post-irradiated MLPA profile that are not present in the controls, and two unique probe signals only seen in WTK1 cells. These results build on our previous studies that indicate how different human cell lines can be affected by radiation in significantly different ways depending on the presence or absence of wild type p53.
文摘Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainly focuses on blast center distance but neglects the amplification effect of blasting vibration waves by terraced terrain,from which the calculated blasting vibration velocities are smaller than the actual values,affecting the safety of the project.To address this issue,our model introduces the influences of slope and time into Sadowski formula to measure safety through blast vibration displacement.In the northern section of the open-pit quartz mine in Jinchang City,Gansu Province,China,the data of a continuous blasting slope project are referred to.Our findings reveal a noticeable vibration amplification effect during blasting when a multi-stage slope platform undergoes a sudden cross-sectional change near the upper overhanging surface.The amplification vibration coefficient increases with height,while vibration waves within rocks decrease from bottom to top.Conversely,platforms without distinct crosssectional changes exhibit no pronounced amplification during blasting.In addition,the vibration intensity decreases with distance as the rock height difference change propagates.The results obtained by the proposed blast vibration displacement equation incorporating slope shape influence closely agree with real-world scenarios.According to Pearson correlation coefficient(PPMCC)analysis,the average accuracy rate of our model is 88.84%,which exceeds the conventional Sadowski formula(46.92%).
基金the National Natural Science Foundation of China,No.82002829.
文摘BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related mortality worldwide.Mesenchymal-epithelial transition factor(MET)gene participates in multiple tumor biology and shows clinical potential for pharmacological manipulation in tumor treatment.MET amplification has been reported in CRC,but data are very limited.Investigating pathological values of MET in CRC may provide new therapeutic and genetic screening options in future clinical practice.AIM To determine the pathological significance of MET amplification in CRC and to propose a feasible screening strategy.METHODS A number of 205 newly diagnosed CRC patients undergoing surgical resection without any preoperative therapy at Shenzhen Cancer Hospital of Chinese Academy of Medical Sciences were recruited.All patients were without RAS/RAF mutation or microsatellite instability-high.MET amplification and c-MET protein expression were analyzed using fluorescence in situ hybridization(FISH)and immunohistochemistry(IHC),respectively.Correlations between MET aberration and pathological features were detected using the chi-squared test.Progression free survival(PFS)during the two-year follow-up was detected using the Kaplan-Meier method and log rank test.The results of MET FISH and IHC were com pared using one-way ANOVA.RESULTS Polysomy-induced MET amplification was observed in 14.4%of cases,and focal MET amplification was not detected.Polysomy-induced MET amplification was associated with a higher frequency of lymph node metastasis(LNM)(P<0.001)and higher tumor budding grade(P=0.02).In the survival analysis,significant difference was detected between patients with amplified-and non-amplified MET in a two-year follow-up after the first diagnosis(P=0.001).C-MET scores of 0,1+,2+,and 3+were observed in 1.4%,24.9%,54.7%,and 19.0%of tumors,respectively.C-MET overexpression correlated with higher frequency of LNM(P=0.002),but no significant difference of PFS was detected between patients with different protein levels.In terms of concordance between MET FISH and IHC results,MET copy number showed no difference in c-MET IHC 0/1+(3.35±0.18),2+(3.29±0.11)and 3+(3.58±0.22)cohorts,and the MET-to-CEP7 ratio showed no difference in three groups(1.09±0.02,1.10±0.01,and 1.09±0.03).CONCLUSION In CRC,focal MET amplification was a rare event.Polysomy-induced MET amplification correlated with adverse pathological characteristics and poor prognosis.IHC was a poor screening tool for MET amplification.
文摘Grovers algorithm is a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The Amplitude Amplification in Grovers algorithm is T = O(N). This paper introduces two new algorithms for Amplitude Amplification in Grovers algorithm with a time complexity of T = O(logN), aiming to improve efficiency in quantum computing. The difference between Grovers algorithm and our first algorithm is that the Amplitude Amplification ratio in Grovers algorithm is an arithmetic series and ours, a geometric one. Because our Amplitude Amplification ratios converge much faster, the time complexity is improved significantly. In our second algorithm, we introduced a new concept, Amplitude Transfer where the marked state is transferred to a new set of qubits such that the new qubit state is an eigenstate of measurable variables. When the new qubit quantum state is measured, with high probability, the correct solution will be obtained.
文摘This article analyzes and discusses the working principle and problems encountered by various servo amplification devices used in the on-site continuous adjustment system,analyzes and discusses the application of the servo mechanism,and analyzes the mechanism of the servo device's implementation of the"positioning"func-tion on the control device.Intended to guide the continuous adjustment process in controlling the function/accuracy of actuator equipment and application debugging,ensuring the safe and stable operation of production equipment and facilities.
基金We thank the Natural Science Foundation of Hubei Province of China(2023AFB330)the China Postdoctoral Science Foundation(2022M721275)the Hubei Provincial Market Supervision Administration Science and Technology Program Project(Hbscjg-KJ2021002)for financial support.
文摘Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.
基金the earmarked fund for Beijing Innovation Consortium of Agriculture Research System(Grant No.BAIC-2019)Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture,P.R.China,and Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(Grant No.CAAS-ASTIPIVFCAAS).
文摘Pectobacterium carotovorum is the causal agent of bacterial soft rot in a wide range of vegetable host species.Once P.carotovorum infects the plant,the spread of the disease is difficult to control.In this study,a rapid and sensitive method based on loop-mediated isothermal amplification(LAMP)was developed for detecting P.carotovorum in celery with soft rot using a primer set designed from the pmrA conserved sequence of P.carotovorum.The specificity of the LAMP primer set for P.carotovorum was extensively validated on both P.carotovorum strains and nontarget strains.The sensitivity was 1 pg of P.carotovorum genomic DNA,which demonstrated 10 times more sensitive than the conventional PCR assay.LAMP was also used to detect P.carotovorum in bacterial suspension.The lowest detection concentration was 104 CFU·mL^−1.In addition,a LAMP assay,in conjunction with a crude DNA extraction method,was successfully performed on P.carotovorum-infected samples derived from both artificially and naturally infected plants.In summary,the LAMP assay established in this study constitutes a simple,sensitive,and rapid method for the detection of P.carotovorum,and has potential application in the control of celery soft rot disease through early detection.
文摘[ Objective ] This study was to investigate the creditability of applying loop-mediated isothermal amplification method (LAMP) to detect Staphylococcus aureus in dairy products. [ Methods] The primers for heat resistant nuclease gene (nuc) of Staphylococcus aureus were designed for establishing the LAMP method for rapidly detecting Staphylococcus aureus. [ Results ] The results of LAMP detection on Staphylococcus aureus in various dairy products were completely identical with that by bacterial isolation test; meanwhile it has a high specificity and a 10-fold sensitivity over the hemi-nested PCR. [ Conclusion] LAMP can be used for the detection of Staphylococcus aureus in dairy products.
文摘A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for human enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) infection was further evaluated. The one step reaction was performed in a single tube at 65?C for 45 min for EV71 and 35 min for CVA16. The detection limits of RT-LAMP assays for both EV71 and CVA16 were 0.1 of a 50% tissue culture infective dose (TCID50) per reaction, based on 10—Fold dilutions of a titrated EV71 or CVA16 strain. The specific assay showed there were no cross-reactions with Coxsackievirus A (CVA) viruses (CVA 2, 4, 5, 7, 9, 10, 14, and 25), Coxsackievirus B (CVB) viruses (CVB 1, 2, 3, 4, and 5) or ECHO viruses (ECHO 3, 6, 11, and 19). In parallel with commercial quantitative real-time polymerase chain reaction (qRT-PCR) diagnostic kits for EV71 and CVA16, the RT-LAMP assay was evaluated with 515 clinical specimens, the results showed the RT-LAMP assay and the qRT-PCR assay were in complete agreement for 513/515 (99.6%) of the specimens. Two samples with discrepant results from two methods were further verified by nested reverse transcription polymerase chain reaction (nRT-PCR) assay and sequencing to be true positives for CVA16. In conclusion, RT-LAMP assay is demonstrated to be a sensitive and specific assay and have a great potential for the rapid and visual screening of EV71 and CVA16 in China, especially in those resource-limited hospitals and rural clinics of provincial and municipal regions.
基金The Science and Technology Commission of Shanghai Municipality under contract Nos 06235810108DZ1980802 and 10JC1418600a special research fund for the national non-profit institutes (East China Sea Fisheries Research Institute) under contract Nos 2007M22 and 2007Z01
文摘A loop-mediated isothermal amplification (LAMP) assay was designed and evaluated for rapid de- tection of the toxic microalgae Alexandrium catenella and A. minutum, which can produce paralytic shellfish poisoning (PSP). Two sets of four specific primers targeting these two species were derived from the sequence of internal transcribed spacer (ITS) of ribosomal DNA. The method worked well in less than an hour under isothermal conditions of 65℃. LAMP specificity was validated in closely related algae as a comparison, suggesting the strict specificity of the LAMP primers. Two visual inspection approaches were feasible to interpret the positive or negative results. The detection lim- its of A. catenella and A. minutum samples using the LAMP assay were found to be 5.6 and 4.5 pg DNA, respectively. The sensitivity of this LAMP assay was 10 or 100-fold higher than Polymerase Chain Reaction (PCR) method in detecting the two microalgae. These characteristics of species specificity, sensitivity, and rapidity suggest that this method has the potentiality in the monitoring of red tide caused by A. catenella and A. minutum.
基金supported financially by a research grant from the Natural Sciences Research Institute,University of the Philippines ) BIO 1 l-l-05) to W.L.R.
文摘Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.histolytica hemolysin gene HLY6.Genomic DNA of E.histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions.Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.Results:Positive LAMP reactions turned turbid while negative ones remained clear.Upon addition of a fluorescent dye,all positive reactions turned green while the negative control remained orange under ambient light After elecrophoresis in 1.5% agarose gels,a ladder of multiple bands of different sizes can be oliserved in positive samples while no bands were detected in the negative control.The sensitivity of the assay was found to be S parasites per reaction which corresponds to approximately 1S.8 ng/μL DNA.The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species,Entamoeba dispar. and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.Conclusions:The I.AMP assay we have developed enables the detection of E.histolytica with rapidity and ease,therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.
基金The Major PLA Research Project of "The 12th Five-Year Plan" for Medical Science Development under contract No.BWS12J014the Primary Research & Development Plan of Shandong Province under contract No.2016GSF121036
文摘Vibrio vulnificus is an estuarine bacterial pathogen for human.The rapid,specific and sensitive detection of V.vulnificus is urgently needed for early disease diagnosis and timely treatment of V.vulnificus infection.In the study,a loop-mediated isothermal amplification(LAMP) technique was developed for V.vulnificus detection with a set of primers,composed of two out primers and two inner primers targeted to vvh A gene.The optimal amplification temperature was 63°C and the reaction only took 35 min.The amplification products could not only be detected by agarose gel electrophoresis with ladder-like pattern bands,but also could be visualized using calcein with naked eye directly.Forty-five strains were tested for the specificity of LAMP assay,and all the V.vulnificus strains were identified correctly while other strains were negative results.The sensitive of the new LAMP assay was 100-fold more sensitive than the conventional PCR.Meanwhile,all the V.vulnificus strains were detected correctly in spiked,clinical and environmental samples by the new LAMP assay.Compared with other well-known techniques,the new LAMP assay targeted to vvh A gene was extremely rapid,simple,sensitive and specific for V.vulnificus identification.
基金funded by the National Key Science and Technology Projects of China(2012ZX10004219 and 2013ZX10004001)
文摘A set of universal loop-mediated isothermal amplification (LAMP) primers targeting the flo gene was designed to detect Borrelia burgdorferi sensu lato (B. burgdorferi s.I.) in human samples. The sensitivity of LAMP was 20 copies/reaction, and the assay did not detect false positives among 11 other related bacteria. A positive LAMP result was obtained for 9 of the 24 confirmed cases and for 12 of 94 suspected cases. The positive rate of LAMP was the same as that of nested PCR. The LAMP is a useful diagnostic method that can be developed for rapid detection of B. burgdorferi s.I. in human sera. Combination of the LAMP and nested PCR was more sensitive for detecting B. burgdorferi s.I. in human serum samples.
基金The grants from the Korea Institute of Ocean Science and Technology under contract No.PE99315
文摘Viral hemorrhagic septicemia virus(VHSV) and marine birnavirus(MABV) are the causative pathogens for some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of pathogen infection. The loop-mediated isothermal amplification(LAMP) of DNA is currently one of the most commonly used molecular diagnostic tools, as it is simple, quick, and easy to amplify target DNA under isothermal conditions. In the present study, a novel and highly specific LAMP assay for the sensitive and rapid detection of VHSV and MABV infection in fish was developed. Using a set of synthesized primers matching a specific region of the genome, the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficient detection of VHSV and MABV infection in the wild fish, Paralichthys olivaceus. Our results demonstrate the simplicity and convenience of this method for the detection of viral infection in aquatic organisms.
基金supported by the Scientific Research Project of General Administration of Quality Supervision,Inspection and Quarantine of P.R.C(2011IK132)the China Mega-Project for Infectious Disease(2013ZX10004-001)
文摘A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for rapid visual detection of Murray valley encephalitis virus (MVEV) infection. The reaction was performed in one step in a single tube at 63 ~C for 60 min with the addition of the hydroxynaphthol blue (HNB) dye prior to amplification. The detection limit of the RT-LAMP assay was 100 copies per reaction based on 10-fold dilutions of in vitro transcribed RNA derived from a synthetic MVEV DNA template. No cross-reaction was observed with other encephalitis-associated viruses. The assay was further evaluated using spiked cerebrospinal fluid sample with pseudotype virus containing the NS5 gene of MVEV.
文摘Plague caused by Yersinia pestis is one of the infectious diseases subject to the International Health Regulations (IHR). Permanent monitoring of the focal plague areas is mandatory in order to enable prompt control measures to prevent the spread of the disease. Therefore, the availability of efficient diagnosis tests is of paramount importance. Here, we describe a loop-mediated isothermal amplification (LAMP)-based procedure for rapid Y. pestis detection. We constructed a set of LAMP primers, which were used in assays to establish the reaction conditions that would lead to the quick visualization of the results by evaluating the test tube with the naked eye. The primers were specifically designed to target the caf1 gene located on pFra/Tox (pMT), a prototypical plasmid of Y. pestis. The LAMP procedure was performed at 65°C for 45 min in a water bath and allowed for the detection of at least 10 pg of bacterial DNA. Due to its simplicity, specificity, sensitivity and rapidity, the LAMP technique is an additional tool that may be implemented in routine plague diagnoses, especially in emergencies.
基金supported by the Sichuan Technology Support Planning (No. 2014 NZ0027)
文摘Loop-mediated isothermal ampliifcation (LAMP) is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chinese giant salamander ranavirus(CGSRV) was developed from culture isolates and clinical samples. The LAMP assay was developed by designing one set of four speciifc primers, targeting the major capsid protein (MCP) gene of CGSRV. Reaction time and temperature were optimal for 40 min at 62°C. The developed LAMP assay is speciifc and highly sensitive for CGSRV detection, the detection limit could reach about 5 copies of cloned viral genomic fragments. The sensitivity of the LAMP assay was about 1000 and 10-fold higher than that of both conventional and nested PCR, respectively. The LAMP ampliifcation produces a typical ladder-like pattern of products on an agarose gel that can be visually inspected after addition of ethidium bromide. The LAMP assay was evaluated further with clinical samples, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for the detection of CGSRV.
基金General Administrationof Quality Supervision, Inspection and Quarantine of China(HK001-2007).
文摘Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method, which amplifies DNA with high specificity, sensitivity, rapidity and efficiency under isothermal conditions using a set of four specially designed primers and a Bst DNA polymerase with strand displacement activity. The basic principle, characteristics, development of LAMP and its applications are summarized in this article.
文摘When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses.Even test samples without any pretreatment can be used as template.This feature suggests that LAMP is superior to PCR in developing point-of-care test strategies.In this study,using Stx1 gene from E.coli as model,we verified that viable cells,dead cells and extracellular DNA could function as template in the LAMP assay.In the incubation at 63℃,viable bacteria in the LAMP reaction mixture lysed completely within 2 min,providing DNA template for nucleic acid amplification.The Stx1 gene in diluted culture medium,spiked tap water,spiked seawater and real seawater all could be detected,with or without the step of DNA extraction.We found that the complex substances in real sample(e.g.natural seawater)exhibited considerable inhibitory effect on the sensitivity of the LAMP assay.These outcomes are meaningful for building a point-of-care strategy by employing the LAMP assay for environmental monitoring,bio-resource surveys,food safety,etc.in particular those based on environmental DNA.