Real-Time PCR Technique and Its Application in Quantification of Plant Nucleic Acid Molecules

Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of initial template copy numbers as PCR products are generated. This technique significantly simplifies and accelerates the process of producing reproducible quantification of nucleic acid molecules. It not only is a sensitive, accurate and rapid quantitative method, but it also provides an easier way to calculate the absolute starting copy number of nucleic acid molecules to be tested. Together with molecular bio-techniques, like microarray, real-time PCR will play a very important role in many aspects of molecular life science such as functional gene analysis and disease molecular diagnostics. This review introduces the detailed principles and application of the real-time PCR technique, describes a recently developed system for exact quantification of AUX/IAA genes In Arabidopsis, and discusses the problems with the real-time PCR process.

Comparative study on efficacy of three sperm-separation techniques

Aim: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) andother two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy ratein intrauterine insemination (IUI) with sperm preparations isolated by these methods. Methods: The effectivenessof the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradientmethods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormalsemen contaminated with microorganisms and other impurities) was evaluated and compared. The microorganisms to beremoved included bacteria, vires, Chlamydia trachomaticum, Ureaplsama urealyticum, etc. The spouse pregnancyrates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients werealso compared. Results: The quality (including the percentages of normal form, normal-chromatin and motilesperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher ( P< 0.01) as compared with those by the other two methods. The Wang's tube method was also more effective in remov-ing microorganisms and other impurities. The method provided a higher IUI pregnancy rate than the other two spermseparation techniques ( P < 0.05). Conclusion: The real-time sperm separation technique is the most effectivemethod so far available in isolating high-quality sperm samples to be used in assisted reproduction.

Clinical significance and influencing factors of linked color imaging technique in real-time diagnosis of active Helicobacter pylori infection

Background:Determining the Helicobacter pylori (H. pylori) infection state during the gastroscopic process is important but still challenging. The linked color imaging (LCI) technique might emphasize the mucosal color change after H. pylori infection, which might help the diagnosis. In the present study, we aimed to compare the LCI technique with traditional white light imaging (WLI) endoscopy for diagnosing active H. pylori infection.Methods:We collected and analyzed gastroscopic images from 103 patients in our hospital from November 2017 to March 2018, including both LCI and WLI modes. All images were randomly disordered and independently evaluated by four endoscopists who were blinded to the H. pylori status of patients. In addition, the H. pylori state was determined by both rapid urease test and pathology staining. The sensitivity, specificity, positive prediction value (PPV), and negative prediction value (NPV) were calculated for the detection of H. pylori infection. Moreover, the kappa value and interclass correlation coefficient (ICC) were used to evaluate the inter-observer variety by SPSS 24.0 software.Results:Of the 103 enrolled patients, 27 of them were positive for H. pylori infection, while the 76 patients were negative. In total, 388 endoscopic images were selected, including 197 WLI and 191 LCI. The accuracy rate for H. pylori evaluation in the corpus LCI group was significantly higher than other groups (81.2% vs. 64.3%-76.5%, χ2 = 34.852, P < 0.001). Moreover, the corpus LCI group had the optimal diagnostic power with the sensitivity of 85.41% (95% confidence interval [CI]: 76.40%-91.51%), the specificity of 79.71% (95% CI: 74.38%-84.19%), the PPV of 59.42% (95% CI: 50.72%-67.59%), and the NPV of 94.02% (95% CI: 89.95%-96.56%), respectively. The kappa values between different endoscopists were higher with LCI than with WLI (0.433-0.554 vs. 0.331-0.554). Consistently, the ICC value was also higher with LCI than with WLI (0.501 [95% CI: 0.429-0.574] vs. 0.397 [95% CI: 0.323-0.474]). We further analyzed the factors that might lead to misjudgment, revealing that active inflammation might disturb WLI judgment (accuracy rate: 58.70% vs. 76.16%, χ2 = 21.373, P < 0.001). Atrophy and intestinal metaplasia might affect the accuracy of the LCI results (accuracy rate: 66.96% vs. 73.47%, χ2 = 2.027;68.42% vs. 73.53 %, χ2 = 1.594, respectively);however, without statistical significance (P = 0.154 and 0.207, respectively).Conclusions:The application of LCI at the corpus to identify H. pylori infection is reliable and superior to WLI. The inter-observer variability is lower with LCI than with WLI.

Real-time and dynamic transduction technique for simultaneous detection of O_2 and CO_2

OXYGEN and carbon dioxide are the coexistent gases closely related to life processes. In our pre-

计算机病毒与反病毒技术的发展

本文对目前计算机病毒的特征、种类、特点、危害进行了新的认识 。

Multiplex qPCR for serodetection and serotyping of hepatitis viruses: A brief review

The present review describes the current status of multiplex quantitative real time polymerase chain reaction(q PCR) assays developed and used globally for detection and subtyping of hepatitis viruses in body fluids. Several studies have reported the use of multiplex q PCR for the detection of hepatitis viruses, including hepatitis A virus(HAV), hepatitis B virus(HBV), hepatitis C virus(HCV), hepatitis D virus(HDV), and hepatitis E virus(HEV). In addition, multiplex q PCR has also been developed for genotyping HBV, HCV, and HEV subtypes. Although a single step multiplex q PCR assay for all six hepatitis viruses, i.e., A to G viruses, is not yet reported, it may be available in the near future as the technologies continue to advance. All studies use a conserved region of the viral genome as the basis of amplification and hydrolysis probes as the preferred chemistries for improved detection. Based on a standard plot prepared using varying concentrations of template and the observed threshold cycle value, it is possible to determine the linear dynamic range and to calculate an exact copy number of virus in the specimen. Advantages of multiplex q PCR assay over singleplex or other molecular techniques in samples from patients with co-infection include fast results, low cost, and a single step investigation process.

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons pro- mote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons （sensory neurons） from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteo- genic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the prolifera- tion of bone marrow mesenchymal stem cell-derived osteoblasts at B and 5 days of co-culture, as observed by fluorescence microscopy. The levels of mRNAs for osteogenic differentiation-re- lated factors （including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2） in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which pro- vides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.

Real-time optimization using gradient adaptive selection and classification from infrared sensors measurement for esterification oleic acid with glycerol

Purpose-The production of glycerol derivatives by the esterification process is subject to many constraints related to the yield of the production target and the lack of process efficiency.An accurate monitoring and controlling of the process can improve production yield and efficiency.The purpose of this paper is to propose a real-time optimization(RTO)using gradient adaptive selection and classification from infrared sensor measurement to cover various disturbances and uncertainties in the reactor.Design/methodology/approach-The integration of the esterification process optimization using self-optimization(SO)was developed with classification process was combined with necessary condition optimum(NCO)as gradient adaptive selection,supported with laboratory scaled medium wavelength infrared(mid-IR)sensors,and measured the proposed optimization system indicator in the batch process.Business Process Modeling and Notation(BPMN 2.0)was built to describe the tasks of SO workflow in collaboration with NCO as an abstraction for the conceptual phase.Next,Stateflow modeling was deployed to simulate the three states of gradient-based adaptive control combined with support vector machine(SVM)classification and Arduino microcontroller for implementation.Findings-This new method shows that the real-time optimization responsiveness of control increased product yield up to 13 percent,lower error measurement with percentage error 1.11 percent,reduced the process duration up to 22 minutes,with an effective range of stirrer rotation set between 300 and 400 rpm and final temperature between 200 and 210℃ which was more efficient,as it consumed less energy.Research limitations/implications-In this research the authors just have an experiment for the esterification process using glycerol,but as a development concept of RTO,it would be possible to apply for another chemical reaction or system.Practical implications-This research introduces new development of an RTO approach to optimal control and as such marks the starting point for more research of its properties.As the methodology is generic,it can be applied to different optimization problems for a batch system in chemical industries.Originality/value-The paper presented is original as it presents the first application of adaptive selection based on the gradient value of mid-IR sensor data,applied to the real-time determining control state by classification with the SVM algorithm for esterification process control to increase the efficiency.

Implementation of Dynamic Line Rating in a Sub-Transmission System for Wind Power Integration

Based on conventional static line rating method, the actual current carrying capability of overhead conductors cannot be judged. Due to continuous increment in electricity demand and the difficulties associated with new line constructions, the overhead lines are therefore required to be rated based on a method that should establish their real-time capability in terms of electricity transmission. The method used to determine the real-time ampacity of overhead conductors not only can enhance their transmission capacity but can also help in allowing excessive renewable generation in the electricity network. In this research work, the issues related to analyzing an impact of wind power on periodical loading of overhead line as well as finding its static and dynamic ampacities with line current are investigated in detail. Moreover, the investigation related to finding a suitable location for the construction of a 60 MW wind farm is taken on board. Thereafter, the wind park is integrated with a regional grid, owned by Fortum Distribution AB. In addition to that, the electricity generated from the wind park is also calculated in this project. Later on, the work is devoted to finding the static and dynamic line ratings for “VL3” overhead conductor by using IEEE-738-2006 standard. Furthermore, the project also deals with finding the line current and making its comparison with maximum capacity of overhead conductor (VL3) for loading it in such a way that no any violation of safe ground clearance requirements is observed at all. Besides, the line current, knowing the conductor temperature when it transmits the required electricity in the presence of wind power generation is also an important factor to be taken into consideration. Therefore, based on real-time ambient conditions with actual line loading and with the help of IEEE-738-2006 standard, the conductor temperature is also calculated in this project. At the end, an economic analysis is performed to evaluate the financial advantages related to applying the dynamic line ratings approach in place of traditional static line ratings technique across an overhead conductor (VL3) and to know how much beneficial it is to temporarily postpone the rebuilding and/or construction of a new transmission line. Furthermore, an economic analysis related to wind power system is taken into consideration as well to get familiar with the costs related to building and connecting a 60 MW wind farm with the regional grid.

关于高校校园网安全若干问题的思考

针对校园网安全的特点,本文着重讨论防火墙、VLAN技术、防病毒技术和访问控制等方面的安全策略,逐步探索校园网安全管理问题的经验,提出加强校园网的安全管理工作的的建议,以期加强校园网安全管理策略,建立起一套适合校园网的安全体系。