Search

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Through the investigation of the spot imprinting defect of electrophoretic, the main reason found for the defect was that the phosphating film was not intact and there were speckles on its surface. The gantry type electrophoresis line phosphating system was improved and the resulting system consisted of phosphating tank body and tank bottom washing system, phosphating slag removal system, phosphating circulating heating system, side circulating system and tank outlet spraying system. This system was an independent and stable phosphating system. The overall circulating mixing speed of tank liquor, the mixing uniformity and the slag removal efficiency were significantly improved, and the phosphating film on the surface of the product was uniform and intact, which ensured the flatness and uniformity of the electrophoretic film, and effectively improved the product qualification rate.

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peach is an important fruit tree species in China, which is widely distributed and ranks the fourth in fruit production. However, there are few varieties suitable for southern cultivation. Through resource surveys in specimen garden of Guangxi University, a new bud sport germplasm was found on a branch of Taiwan precocious peach tree, named ‘May Red'. Its main biological characteristics, botanical traits, fruit economic traits and so on were observed and analyzed. At the same time, SRAP molecular markers were used to detect the differences between ‘May Red' and Taiwan precocious peach. The results showed that the maturity of ‘May Red' was about 20 d earlier than that of Taiwan precocious peach, matured in mid-May with large fruit, smaller nucleus and higher edible rate. Moreover, the color was uniform, the soluble solids content was significantly increased, and it maintained the advantages of low cold requirement, excellent qua-lity and excellent flavor of Taiwan precocious peach. It belonged to especially early maturing and high quality germplasm resources. The specific bands of 1 200 bp in ‘May Red' DNA samples were amplified by SRAP primers me9/em5 by agarose electrophoresis, which indicates that ‘May Red' are mutated at the DNA genetic level and belongs to a new especially early maturing germplasm resource. The discovery of ‘May red' will provide important materials for the breeding of especially early maturing peach varieties. It will help to optimize the cultivation structure of different mature varieties and promote the economic benefit of southern peach planting industry. [ABSTRACT FROM AUTHOR]

Microchip electrophoresis (MCE) is widely applied in food, environment, medicine, and other fields, owing to its high separation efficiency, low consumption of reagents and samples, and ease of integrating multiple operating units. Polymer microchip materials like cycloolefin copolymer (COC) are low-cost and easy to fabricate. However, their practical applications are limited by the non-specific adsorption on channel surface during electrophoresis and the instability of electroosmotic flow. These shortcomings can be solved by COC surface modification. In this study, a static coating and dynamic/static coating combined strategy was used to develop a channel-surface-modified COC microchip. Combined with laser-induced fluorescence (LIF) detection, a MCE-LIF separation and analysis method was developed for detecting functional components in health care products. The separation performance of MCE was improved by the static coating microchannel surface modification method. The static coating was constructed by hydrophobic amino acid adsorption, glutaraldehyde immobilization, and hydrophilic amino acid functionalization on the COC microchannel surface. The separation performance of MCE was improved by microchannel surface modification combined with dynamic/static coating. The static coating was constructed by valine adsorption, carboxyl activation, and ethylenediamine functionalization on the COC microchannel surface. The dynamic coating is automatically formed by introducing a buffer solution containing hydroxypropyl methylcellulose and sodium dodecyl sulfate into the microchannel. The physical and chemical properties of surface-modified microchannels and the factors governing electrophoretic separation were studied. Combined with LIF detection, the MCE-LIF separation and analysis of lysine and γ -aminobutyric acid present in children's health care products, as well as aspartic acid and taurine in sport drinks, were developed. The recoveries of lysine and γ -aminobutyric acid in children's health care products were 84.8%-118%, and the relative standard deviations (RSDs) were less than 7.2% ( n =3). The recoveries of aspartic acid and taurine in sport drinks were 97.5%-118%, and the RSDs were less than 6.4% ( n =3). The analysis results are consistent with the HPLC results, and the method has potential for application in the separation and analysis of anionic amino acids in health care products.

Electrophoresis titration (ET) based on the moving reaction boundary (MRB) theory can detect the analyte contents in different samples by converting content signals into distance signals. However, this technique is only suitable for on-site qualitative testing, and accurate quantification relies on complex optical equipment and computers. Hence, applying this method to real-time point-of-care testing (POCT) is challenging. In this study, we developed a smartphone-based ET system based on a visual technique to achieve real-time quantitative detection. First, we developed a portable quantitative ET device that can connect to a smartphone; this device consisted of five components, namely, an ET chip, a power module, a microcontroller, a liquid crystal display screen, and a Bluetooth module. The device measured 10 cm×15 cm×2.5 cm, weighed 300 g, and was easy to hold. Thus, it is suitable for on-site testing with a run time of only 2-4 min. An assistant mobile software program was also developed to control the device and perform ET. The colored electrophoresis boundary can be captured using the smartphone camera, and quantitative detection results can be obtained in real time. Second, we proposed a quantitative algorithm based on ET channels. The software was used to recognize the boundary migration distance of three channels, a standard curve based on two given contents of the standards was established using the two-point method, and the content of the test sample was calculated. Human serum albumin (HSA) and uric acid (UA) were used as a model protein and biosample, respectively, to test the performance of the detection system. For HSA detection, different HSA solutions were mixed with a polyacrylamide gel (PAG) stock solution, phenolphthalein was added as an indicator, and sodium persulfate and tetramethyl ethylenediamine (TEMED) were used to promote polymerization to form a gel. For UA detection, agarose gel was filled into the ET channel, the UA sample, urate oxidase, and leucomalachite green were added into the anode cell and incubated for 20 min. ET was then performed. The fitting goodness ( R 2 ) values of HSA and UA were 0.9959 and 0.9935, respectively, with a linear range of 0.5-35.0 g/L and a log-linear range of 100-4000 μmol/L. The limits of detection for HSA and UA were 0.05 g/L and 50 μmol/L, respectively, and the corresponding relative standard deviations (RSDs) were not greater than 2.87% and 3.21%, respectively. These results demonstrate that the detection system has good accuracy and sensitivity. Clinical samples collected from healthy volunteers were used as target blood samples, and the developed system was used to measure serum total protein and UA levels. Serum samples from five volunteers were selected, standard curves of total serum protein and UA were established, and the test results were compared with hospital standard testing results. The relative errors for serum total protein and UA were less than 6.03% and 6.21%, respectively, and the corresponding RSDs were less than 3.72% and 5.84%, respectively. These findings verify the accuracy and reliability of the proposed detection system. The smartphone-based ET detection system introduced in this paper presents several advantages. First, it enables the portable real-time detection of total serum protein and UA. Second, compared with traditional ET strategies based on colored boundaries, it does not rely on optical detection equipment or computers to obtain quantitative detection results; as such, it can reduce the complexity of the operation and provide portability and real-time metrics. Third, the detection of two biomarkers, serum total protein and UA, is achieved on the same device, thereby improving the multitarget detection potential of the ET method. These advantages render the developed method a promising detection platform for clinical applications and real-time POCT.

Objective To estimate the accuracy and stability of capillary electrophoresis fragment analysis and clone sequencing in detecting dynamic mutations of spinocerebellar ataxia (SCA). Methods Capillary electrophoresis fragment analysis and clone sequencing were used in detecting trinucleotide repeated sequence of 14 SCA patients (3 cases of SCA2, 2 cases of SCA7, 7 cases of SCA8 and 2 cases of SCA17). Results Capillary electrophoresis fragment analysis of 3 SCA2 cases showed the expanded cytosine-adenine-guanine (CAG) repeats were 31, 30 and 32, and the copy numbers of 3 clone sequencing for 3 colonies in each case were 37/40/40, 37/38/39 and 38/39/40 respectively. Capillary electrophoresis fragment analysis of 2 SCA7 cases showed the expanded CAG repeats were 57 and 34, and the copy numbers of repeats were 69, 74, 75 in 3 colonies of one case, and was 45 in the other case. For the 7 SCA8 cases with the expanded cytosine-thymine-adenine (CTA)/cytosine-thymine-guanine (CTG) repeats of 99, 111, 104, 92, 89, 104 and 75, the results of clone sequencing were 97, 116, 104, 90, 90, 102 and 76 respectively. For 2 SCA17 cases with the short/expanded CAG repeats of 37/50 and 36/45, the results of clone sequencing were 51/50/52 and 45/44 for 3 and 2 colonies. Conclusions Although the higher mobility of polymerase chain reaction (PCR) products containing dynamic mutation in the capillary electrophoresis fragment analysis might cause the deviation for analysis of copy numbers, the deviation was predictable and the results were repeatable. The clone sequencing results showed obvious instability, especially for SCA2 and SCA7 genes, which might owing to their simple CAG repeats. Consequently, clone sequencing is not suited for detection of dynamic mutation, not to mention the quantitative criteria of dynamic mutation sequencing. [ABSTRACT FROM AUTHOR]

The sensitivity, accuracy, and efficiency of fluorescent particle detection can be improved by purifying the fluorescent-dye-labeled particles. In this study, an in-site model of electrophoretic elution (EE) was developed for the facile and efficient removal of unconjugated fluorescent dyes after labeling reactions, thereby facilitating the sensitive fluorescent imaging of proteins captured by microbeads. First, bovine serum albumin (BSA) and magnetic beads (MBs) were chosen as the model protein and particles, respectively, and an MBs-BSA complex was synthesized by mixing the beads with the BSA solution. Second, excessive fluorescein isothiocyanate (FITC) was added to the EP tube with MBs-BSA suspension for the fluorescent labeling of BSA, and a labeled compound was obtained after 8-h incubation in the dark at 4 ℃. The unpurified MBs-BSA FITC was obtained by removing the supernatant, leaving 5 μL of the residual solution in the EP tube. The obtained MBs-BSA FITC solution was added to a 50-μL phosphate buffer solution (PBST, containing 0.01% Triton X-100, pH 7.4). Third, gel suspension was prepared by mixing the MBs-BSA FITC solution with the low-gelling-temperature agarose gel (10 g/L) and filled into an electrophoresis channel. To demonstrate the high efficiency of the in-site model of EE for removing excessive FITC, a 10-mm hydrogel segment was prepared using MBs-BSA FITC sandwiched between two blank hydrogels and filled into a 50-mm-long electrophoresis tube (outer diameter: 5 mm; inner diameter: 3 mm) for the EE. Subsequently, the filled channel was set in an electrophoresis device to construct the in-site EE model. The particle size of the MBs was larger than the pore size of the gel, and the fluorescent beads were physically immobilized in the gel while the excessive FITC was removed from the channel by electrophoresis. Before an EE run, the original fluorescence image of the target gel was captured using a CCD camera. After the 30-min EE (50 V, 6 mA, pH 7.4 PBS), the fluorescence image was also recorded by the CCD camera. The fluorescent images were converted to a grayscale intensity map. To simplify the calculation, a simple fluorescent image analysis method was developed. The side view of the grayscale intensity map is a two-dimensional plot of peaks. Each peak indicates a fluorescent spot at a given position along the length of the channel when the distribution density of the particles is low, and the peak value is the grayscale intensity of the fluorescent spot. The statistical peak numbers and values can be used to approximate fluorescent spots on the image. After image processing and calculations, 27.8% of the average grayscale intensity of the fluorescent spot was retained, comparing the average gray value of the bright spot before and after EE, and 97.6% of excessive FITC in the channel was cleared, obtained by calculating the decreased background fluorescence grayscale intensity after EE. The particle-to-background signal ratio (P/B ratio, PBr) increased from 1.08 to 12.2 after EE with an exposure time of 1.35 s. In addition, different exposure times were explored during the fluorescence detection. Increasing the exposure time from 1.35 to 2.35 s enhanced PBr from 12.2 to 15.5, which could effectively increase the signal-to-noise ratio. An appropriate increase in exposure time also allowed the detection of many weak fluorescent particles that were previously undetectable, indicating increased sensitivity of the fluorescence detection. The EE model has the following advantages: (i) increase in specificity by eluting FITC absorbed to the surface of beads; (ii) high efficiency in the removal of free FITC with more than 97% clearance; (iii) rapid decrease in noise in the mass hydrogel (within 30 min). This method can be used in beads/spots-based immunoassay in gel, immuno-electrophoresis, and fluorescent staining of protein/nucleic acid bands in gel electrophoresis.

Background and objective Silicon nanoparticles are widely used in daily life. Therefore, they attract increased attention because of their potential biotoxicity to the lungs when inhaled. The aims of this study are to explore the organism distribution and genotoxicity of silica nanoparticles in human bronchial epithelial cells (BEAS-2B). Methods The biodistribution of silica with different particle sizes in human bronchial epithelial cells was observed by transmission electron microscopy (TEM). DNA damage was detected by single-cell gel electrophoresis (comet assay). Results TEM revealed that SiO2 nanoparticles with different sizes can be uptaken by cells and be localized in the cytoplasm and the nucleus. Compared with micro-silica, nano-silica in BEAS-2B cells can inflict more severe DNA damage (P<0.05). Conclusion The particle size of silica nanoparticles can be used to determine their distribution in biological cells. Compared with micro-silica, nano-silica has higher genotoxicity. [ABSTRACT FROM AUTHOR]

Free-flow electrophoresis (FFE) is an all-liquid-phase electrophoresis technique without any supporting media, which has both analytical and preparative functions. Compared to other electrophoresis techniques, FFE has been used for the separation of peptides, proteins, cells, and microorganisms due to its advantages of mild separation environment, high recovery, and sustainable separation. Both the online detection of the characteristic parameters for each component solution and the real-time control of the progress of the separation experiment are of considerable importance for the study of FFE separation. Since the existing FFE devices do not have the online detection function, there are obvious deficiencies in their practicability. The absence of online detection function not only made it impossible to track the progress of the separation experiment in real time, but also made it difficult to detect the properties of the component solutions, which still require offline testing after separation. In this study, a multi-channel capacitively coupled contactless conductivity detection (MC-C 4 D) device has been developed to solve this problem, and an automatic measurement software has also been developed. The MC-C 4 D device used a parallel time-sharing contactless conductivity detection technique. It consisted of several contactless conductivity detection modules arranged in parallel, which in turn consisted of a number of contactless conductivity cells that were switched on/off by analog multiplexers for detecting the conductivity of the solution flowing through the cells in real time. The number of cells was equal to the number of components of the FFE. The components were connected to each of the FFE flow channels, such that the MC-C 4 D device could be used to measure the conductivity of the solution flowing through each channel in parallel online. To verify the performance of the MC-C 4 D device, calibration was conducted by using potassium chloride (KCl) standard solutions on MC-C 4 D device. The experimental data showed that the detection range of MC-C 4 D was 0.015-2.5 mS/cm, and the limit of detection (LOD) was 0.002 mS/cm. The intra-day relative standard deviation (RSD, n =3) was 2.31%, the measurement relative error (RE) was 3.03%, and the measurement difference between channels was 1.60%. All these data validated that the device had the advantages of wide detection range, low LOD, good repeatability, high accuracy, and low variation between channels. The MC-C 4 D device was also applied to reciprocating free-flow isoelectric focusing (RFFIEF) electrophoresis for real-time online detection of the conductivity of each component solution during protein focusing. At the start of isoelectric focusing, when the ions had not reached equilibrium loading in the electric field and the pH gradient had not yet been fully developed, there was little difference in conductivity between the different channels and the channel conductivity curve was relatively flat. As the experiment progressed, the proteins gradually started to enrich the anodic end. As the proteins accumulated towards the isoelectric point, their own net charge gradually decreased, and thus, the conductivity of the solution in the channels near the anodic region also decreased. Under sufficient isoelectric focusing, protein enrichment was evident. In the focusing region, the conductivity of the solution in the corresponding channel decreased further. There was also an increase in the conductivity of the solution in the corresponding channel due to the accumulation of ions near the electrode ends. These results showed that the MC-C 4 D device not only enabled real-time online detection of the conductivity of each component solution in FFE, but also aided in mastering the progress of separation experiment in RFFIEF, thus improving the practicality of the FFE device. Thus, the MC-C 4 D device, which had the advantages of good performance, small size, simple circuit system, easy installation and commissioning, and low cost, could play an important role in multi-channel measurement, online inspection, and process monitoring.

Background and objective Chemotherapy plays an important role in the comprehensive therapy of lung cancer. However, the drug-resistance often causes the failure of the chemotherapy. The aim of this study is to identify differently expressed protein before and after cisplatin resistance of human lung adenocarcinoma cell A549 by proteomic analysis. Methods Cisplatin-resistant cell strain A549/CDDP was established by combining gradually increasing concentration of cisplatin with large dosage impact. Comparative proteomic analysis of A549 and A549/CDDP were carried out by means of two-dimensional gel electrophoresis. The differentially expressed proteins were detected and identified by MALDI-TOF mass spectrometry. Results Eighty-two differentially expressed proteins were screened by analysis the electrophoretic maps of A549 and A549/CDDP. Six differential proteins were analyzed by peptide mass fingerprinting. Glucose regulating protein 75, ribosomal protein S4, mitochondrial ATP synthase F1 complex beta subunit and immunoglobulin heavy chain variable region were identified. All four differentially expressed proteins were over-expressed in A549/CDDP, whereas low-expressed or no-expressed in A549. Conclusion These differentially expressed proteins give some clues to elucidate the mechanism of lung cancer cell resistant of cisplatin, providing the basis of searching for potential target of chemotherapy of lung cancer. [ABSTRACT FROM AUTHOR]

The novel coronavirus disease 2019 (COVID-19) outbreak has brought to light unprecedented challenges to global public health security. Researchers have devoted their efforts to in-depth research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to bring the epidemic under control as rapidly as possible. Among the many areas of burgeoning SARS-CoV-2 related research, various analytical technologies have been applied to the advancement of virus detection, and development of vaccines and innovative therapies. Separation technologies with the merits of simple operation, high separation efficiency, and high selectivity, have become widely used and are key to progress in life science, medicine, pharmaceutical discovery and development, and other fields. Separation technologies have played an irreplaceable role in the isolation, detection, diagnosis, treatment, and prevention of this novel coronavirus. In this review, an overview of the relevant literature is presented from ISI Web of Science spanning Jan. 1st, 2020-Dec. 31, 2020, using "SARS-CoV-2" or "COVID-19" as keywords. The top 20 research directions are summarized, based on papers published in high impact international journals (e. g. Nature , Science , and Cell ). Incorporating the impact of published papers, this review summarizes the primary separation technologies applied in these coronavirus studies, and discusses contributions of the following six technologies: affinity chromatography and size exclusion chromatography, liquid chromatography, magnetic bead separation technology, centrifugal technology, micro/nano-separation technology, and electrophoresis. First, affinity chromatography and size exclusion chromatography are discussed, which are the most frequently used protein purification techniques in Nature , Science , and Cell . The SARS-CoV-2 related proteins purified by affinity chromatography and size exclusion chromatography are summarized, and their applications in coronavirus transmission, infection mechanisms, and drug screening are introduced. Subsequently, high performance liquid chromatography (HPLC) is introduced, which is mainly employed for assessing the purity of candidate drugs. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) incorporates the strengths of HPLC and MS, offering both high separation efficiency and structural analysis capabilities with extended applications. LC-MS/MS has been applied to characterization of the binding of SARS-CoV-2 related proteins to potential inhibitors, and to metabolic analyses of candidate drugs. In SARS-CoV-2 nucleic acid tests, magnetic bead separation technology plays a crucial role in the separation of novel coronaviruses. In combination with other analytical techniques, magnetic bead separation technology can be applied to cytological analyses and immunological detection by functionalization of bead surfaces. Centrifugal technology is undoubtedly the most basic separation technology. It has been employed in almost all SARS-CoV-2 related researches. By controlling centrifugation speed, centrifugal technology can rapidly isolate virus particles or cultured cells from complex samples. Micro-nano separation technologies, such as microfluidics, offer advantages including small size, low sample consumption, rapid diffusion, and large surface area. In general, microfluidic technologies are often used in combination with other technologies to realize highly sensitive detection of SARS-CoV-2 related proteins. Finally, the applications of electrophoresis are introduced, which commonly engages in the analysis of polymerase chain reaction (PCR) products. In novel coronavirus studies, the application of electrophoresis has been relatively limited but has potential with further development to contribute significantly to future research. In conclusion, this review summarizes the contributions of six primary separation technologies to novel coronavirus studies, including epidemic detection and prevention, analyzes the main problems facing coronavirus detection efforts, and discusses the role of separation technologies in addressing these problems, with the aim of providing references for broader application of separation technologies.

Linear electroseparations in vacuum, gas phase and liquid phase have created mass spectrometry, ion mobility spectrometry, electrophoresis and capillary electrophoresis. However, they have not systematized yet, developing independently, with their own theory, not related to each other. In this paper, unified motion equations were derived from the second law of Newtonian mechanics combined with electrostatic theory. From them, the general sub-equations of motion and measurement modes of all the above-mentioned methods were deduced and discussed briefly. These equations are not only helpful to systematize these existing methods but also are usable to deduce and discover novel electro-separation modes.

A new portable method for the detection of horseradish peroxidase (HRP) is reported in this paper. Visualized and quantitative detection of HRP was achieved based on the theory of electrophoresis titration (ET) and redox reaction boundary (RB). The ET-RB model was built on the 3,3',5,5'-tetramethyl benzidine chromogenic system because it significantly increases the efficiency of the chromogenic reaction and can react with L-ascorbic acid. A series of experiments were performed on a tiny and portable titration chip based on the material of polymethyl methacrylate designed for the developed model. The composition of the titration gel was optimized to ensure higher detection sensitivity and stable detection performance. The experimental results manifested a log-linear relationship between the moving distance of the RB and the HRP concentration. The dynamic range of the developed method ranged from 0.002 to 0.073 mg/L, and the detection could be accomplished within 10 min. Visualized and quantitative detection could be realized by reading the moving distance of the colored boundary with the naked eyes instead of using any signal-reading device or analyzing instrument. Thus, this method has great potential for further application to the development of a real-time detection method for various target substances based on the detection of peroxidase activity.

Objective: To evaluate the role of combined detections of routine blood test, serum iron and hemoglobin electrophoresis in screening thalassemia in non- high incidence area. Methods: Peripheral blood and serum samples of 1 000 outpatients from the department of hematology and the department of gynecology and obstetrics were obtained. Common mutations of thalassemia were detected by using GAP- PCR and reverse dot blotting, and Sanger sequencing was performed to discover rare mutations of α- and β- thalassemia. Routine blood test, serum iron and hemoglobin electrophoresis were also performed for every patient. Results: Among 1 000 samples, 225(22.5%)are detected as α-thalassemia, 403(40.3%)β-thalassemia and 15(1.5%)composite thalassemia. Among 225 α-thalassemia patients, 28 were silent, 138 were intermedia, and 59 were HbH disease. Of 403 β-thalassemia, 390 were carriers, 7 were double heterozygote, and 6 were homozygote. In all samples, there were 357 patients detected with no common mutations, 38 patients had higher result values for both MCV and MCH and none detected with thalassemia gene. There were 48 patients who had higher serum iron but normal or lower MCV, 42 of them(87.5%)had thalassemia gene. Furthermore, 38 patients showed abnormal hemoglobin electrophoresis, 35 of them were HbH disease, while the other 3 were HbF- related thalassemia. Five patients showed abnormal hemoglobin electrophoresis, lower MCV and MCH, as well as higher serum iron, had no frequent mutation but rare ones. Conclusion: Patients with higher MCV and MCH can mostly be excluded to have thalassemia, while higher serum iron represents thalassemia possibility and can provide a preliminary indication of thalassemia type, and last but not least abnormal hemoglobin electrophoresis indicates the disease. It is recommended to further carry out sequencing of rare mutations for those who had abnormal results in the combined screening, and detected with no frequent mutation. Combination of these three examinations can improve the detection efficiency of patients with thalassemia.

Preparative electromigration techniques are a category of separation and preparation techniques based on differential electromigration principle. These techniques are widely applied in biomacromolecule and proteome researches. Related techniques mainly include preparative electrophoresis, preparative electrochromatography, preparative isoelectric focusing and free flow electrophoresis and so on. We review each kind of the preparative electromigration techniques on its apparatus designs, applications, advantages and disadvantages in detail. Microscale preparative electrophoresis is a hot spot in recent years. Its high resolution, high recovery and high efficiency make it a more prominent role in the biological sample analysis. In this review, we focus on some advances in microscale preparative electrophoresis and also give an outlook on preparative electromigration techniques in the future.

Secretome (secreted proteins) has been arousing considerable attention because of its potential to develop novel biomarkers for the early detection and diagnosis of diseases. Like other proteome systems, a secretome generally consists of thousands of proteins with a wide dynamic range of abundance. The effective way to decrease the complexity of the analyte is to combine different prefractionation methods with orthogonal separation capabilities. The newly appeared OFFGEL fractionation system provides the ability to separate the peptides into discrete liquid fractions according to their differences in isoelectric point (pI), and has demonstrated high efficiency and repeatability for the analysis of the complex proteins. Here the OFFGEL fractionation system was evaluated for the separation of peptides digests from secreted proteins of hepatocellular carcinoma cells (HCC), using a 12-wells device encompassing the pH range of 3 - 10. In combination with the online reversed phase liquid chromatography and mass spectrometry, peptides from the digestion of MHCC97L secreted proteins were separated and identified. Preliminary results showed that nearly 80% of the peptides identified were specific to one fraction, and 40% of the proteins were obtained from the fractions 1 -3 from the acid end. The average of peptide pI values distributed in each fraction is consistent with the theoretical pIs, and the pI distribution of the peptides focused on the low pH range showed a smaller deviation. Finally, 2 995 proteins were identified from secretome of MHCC97L cell lines. Thus the data show that the OFFGEL system provides a highly valuable tool to fractionate peptides from complex protein samples.

Objective: To establish an effective method for purification of Helicobacter pylori UreB fragment and conduct functional analysis of the purified protein., Methods: The protein fragment expression was induced by IPTG and the expressed protein was purified through affinity chromatography and ion-exchange chromatography. The purity of the fragment was determined by high-performance liquid chromatography (HPLC), and the specific biological activity of the purified fragment was assayed by urease activity inhibition test., Results: The protein fragment was highly expressed in E. coli with a purity over 91%. The protein fragment showed highly specific biological activity and the specific antibody induced by this fragment in rabbits could inhibit the activity of urease in a dose-dependent manner., Conclusion: The UreB fragment with high purity and biological activity can be applied for further studies.

Objective: To investigate the effect of bortezomib alone and in combination with arsenic trioxide on apoptosis of HL-60 cells., Methods: HL-60 cells were treated with bortezomib alone or in combination with arsenic trioxide for 12 to 48 h and the cell proliferation was analyzed with MTT assay, and cell apoptosis detected by DNA gel electrophoresis, fluorescence microscopy and flow cytometry., Results: At the concentrations of 10 to 50 nmol/L, bortezomib effectively inhibited HL-60 cell proliferation, and induced cell apoptosis. A 12-hour bortezomib treatment at 10 nmol/L was sufficient to induce cell apoptosis, and prolonged treatment or increased concentration significantly increased HL-60 cell apoptotic rate. Combined treatment of the cells with bortezomib (10 nmol/L) and arsenic trioxide (15 micromol/L) resulted in an even higher cell apoptosis rate than that induced by the respective agent alone., Conclusion: Bortezomib can induce HL-60 cell apoptosis in a time- and dose-dependent manner, and a synergistic effect can be observed of bortezomib and arsenic trioxide in apoptosis induction.

DFPase can hydrolyze the P-F bond of diisopropyl phosphate fluoride (DFP) to produce diisopropyl phosphate and HF. In this article, the activity of two kinds of DFPase from porcine liver was assayed by the methods of titration and F- ion sensitive electrode. The results showed that the activity of large molecular DFPase can be determined by both methods, but the activity of small molecular DFPase can only be determined by the titration and cannot be determined by F- ion sensitive electrode. The isotachophoresis analysis of the products of DFP hydrolyzed by the large and small molecular DFPase was studied. The results showed that the small molecular enzyme could catalyze the hydrolysis of DFP, but without the production of F- ion, and that this enzyme is one kind of phosphoesterase that hydrolyzed P-OR bond of DFP.

A multiparametric analysis was made to demonstrate that brief period of ischemia can initiate extensive loss in a rat kidney through the process of apoptosis during early reperfusion. Microscopic examination of mouse renal tissues subject to a 5, 30, or 45 minute period of complete ischemia showed the presence of apoptotic bodies both within and occasionally between renal tubular, appearing as early 6 hours after reperfusion and increasing in numbers at 12 hours. Furthermore, DNA extracted from such reperfusion renal tissue demonstrated the appearance of a distinct "ladder pattern" of DNA fragments after electrophoresis in agarose gels. It was suggested that renal reperfusion injury after ischemia can initiate a form of cell death-apoptosis that is drastically different from cellular necrosis induced by prolonged severe ischemia.