Visual Detection of Vibrio parahaemolyticus using Combined CRISPR/Cas12a and Recombinase Polymerase Amplification / 生物医学与环境科学（英文）

Objective@#To establish an ultra-sensitive, ultra-fast, visible detection method for Vibrio parahaemolyticus (VP) .@*Methods@#We established a new method for detecting the tdh and trh genes of VP using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 12a (CRISPR/Cas12a) combined with recombinase polymerase amplification and visual detection (CRISPR/Cas12a-VD).@*Results@#CRISPR/Cas12a-VD accurately detected target DNA at concentrations as low as 10 -18 M (single molecule detection) within 30 min without cross-reactivity against other bacteria. When detecting pure cultures of VP, the consistency of results reached 100% compared with real-time PCR. The method accurately analysed pure cultures and spiked shrimp samples at concentrations as low as 10 2 CFU/g.@*Conclusion@#The novel CRISPR/Cas12a-VD method for detecting VP performed better than traditional detection methods, such as real-time PCR, and has great potential for preventing the spread of pathogens.

Effects of soybean isoflavones on the energy metabolism of swimming mice / 中国应用生理学杂志

OBJECTIVE@#To establish an animal model for loaded swimming, so as to investigate the energy metabolism effects of soybean isoflavones (SI) on swimming mice.@*METHODS@#Thirty male Kunming mice were randomly divided into three groups:normal control, swimming group, and swimming+SI group. The normal control group mice were fed a basic AIN-93M diet, the SI groups were supplied with soybean isoflavones(4 g/kg).Two weeks later, the mice were forced to swim for an hour,and then all the mice were killed, the samples of blood, liver and muscles of hind were collected.The serum contents of lactic acid(Lac), the activities of lactic dehydrogenase (LDH), succinate dehydrogenase (SDH), creatine kinase (CK) and ATPase were measured.@*RESULTS@#Compared with normal control,the serum content of Lac was significantly improved in the group of the swimming control and SI(<0.05),the activity of LDH in the serum was obviously improved in the group of the swimming control and SI, and the activity of CK and SDH were both significantly improved in the group of the swimming control and SI except the activity of SDH in the liver of the group SI; compared with the swimming control,the serum contents of Lac,the activities of LDH, ATPase, SDH, CK were obviously improved(<0.05).@*CONCLUSIONS@#Soybean isoflavones can improve the energy metabolism,antioxidant capacity of the swimming mice.

High sensitive ELISA for detection of atrazion / 中国应用生理学杂志

OBJECTIVES@#To set up ELISA for detection of atrazine with high precision.@*METHODS@#The reaction condition of indirect-ELISA was optimized, including atrazine-ovalbumin(AT-OVA) concentration and primary antibody concentration, organic solvent, goat anti-rat immunoglobin G-horseradish peroxidase(IgG-HRP) concentration. The actual samples were detected by the ELISA method established in our laboratory. Then the ELISA method was compared with the HPLC.@*RESULTS@#The specification curve of indirect-ELISA was set up after optimization. The relation coefficient R=0.9958. The limit of detection (LOD) was 1.972 ng/ml. The percent recovery of the actual samples was in range of 80%~120%. The ELISA detection sensitivity was higher than the HPLC in the range of 0 ng/ml~6 ng/ml atrazine.@*CONCLUSIONS@#The ELISA to detect atrazine has good specificity and high precision. And it can be applied in testing real atrazine samples replacing of the large-scale instrument.

Efficient Detection of Environmental Estrogens Bisphenol A and Estradiol By Sensing System Based on AuNP-AuNP-UCNP Triple Structure / 分析化学

A sensing system based on AuNP-AuNP-UCNP triple structure for efficient detection of dual targets was constructed. In the preparation of triple structure, the gold nanoparticles (AuNPs) and upconversion nanoparticles (NaYF4: Yb, Er, Gd, UCNPs) were synthesized and surface modified. Then the two nanoparticles and their aptamers were connected to form two kinds of optical fluorescent probes. A nucleic acid sequence that matches with two aptamers was designed, rendering the probes to get close based on the principle of complementary base pairing. On the basis of this, a sensing system with a triple structure was prepared,and its connecting effect was characterized by TEM. With this system, dual targets of bisphenol A and estradiol were efficiently and conveniently detected through quantitative determination by fluorescence and UV spectrophotometer. At reaction temperature of 30℃ and pH=7.8,this method exhibited good linear range for determination of bisphenol A and estradiol from 2 ng/mL to 200 ng/mL and from 10 ng/mL to 150 ng/mL, with limits of detection of 0.2 ng/mL and 0.5 ng/mL, respectively. This sensing system with the triple structure owned better specificity to structural and functional analogues, and showed good repeatability and stability. What's more,this sensing system was applied in actual water detection,with the recoveries between 86.1% and 107. 4%, and the relative standard deviation below 6. 8%. This method showed promising applications in other environmental estrogens in water samples.

Purification of monoclonal antibody to clenbuterol and its biology identity / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To identify the self-preparation monoclonal antibody which target to clenbuterol, and set up the standard curve to clenbuterol (CL) detection.</p><p><b>METHODS</b>The affinity constants and activity of the monoclonal antibody which target to CL were determined by ELISA. ELISA was also used to confirm whether the monoclonal antibody had any across-reaction with BSA and CL analogues. The rat ascites which contains the monoclonal antibody target to CL was purified by (NH4)2SO4 salt-out method and further by affinity column. At last, the CL detection standard curve which based on indirect competition ELISA was established.</p><p><b>RESULTS</b>The ELISA experiment showed that the antibody titer was 10(6) and the monoclonal antibody affinity constants was 2.90 x 10(10) L/mol. The result of the indirect competition ELISA confirmed that the monoclonal antibody had no cross-reaction with BSA and a few kind of CL analogue. CL detection standard curve based on indirect competition ELISA was established, which R2 was 0.9812, and the lowest detectable limit was 1.0 ng/ml.</p><p><b>CONCLUSION</b>The standard curve based on indirectly competitioning ELISA was established. The self-preparation monoclonal antibody which target to CL has high affinity and high specific to CL, which had established the foundation to the advanced development of the CL immune test paper and CL ELISA kit.</p>

Development of a high-throughput suspension microarray technology for detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-beta-estradiol / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish a novel suspension microarray technology for the detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-beta-estradiol (CAP, CL and E2).</p><p><b>METHODS</b>The three conjugates that veterinary drug coupled with bovine serum albumin (BSA) were synthesized and identified by ultraviolet (UV) spectrophotometry and mass spectrum. The veterinary drug conjugates were immobilized on the polystyrene fluorescent microspheres/beads. There were competitive reactions between the veterinary drugs in the aqueous phase and that on the beads for combination with their specific biotinylated monoclonal antibodies. The optimum amount of the veterinary drug conjugates and the antibodies were optimized and selected. The detective standard curves were plotted. The specificity and the unknown samples were also determined by grouping according to different concentrations of the interferes and the samples. Meantime, the different microstructures of the surfaces of the beads were also observed by scanning electron microscope.</p><p><b>RESULTS</b>Couplings were completed between small molecular veterinary drugs and BSA. The amounts of the three conjugates and the antibodies were optimized. The detective standard curves of the suspension array and their corresponding coefficients of determination (R2) were good (R2 > 0.99). The detection ranges of the three veterinary drugs were (40.00 - 6.25) x 10(5) ng/L, (50.00-7.81) x 10(5) ng/L and 1.00 x 10(3) - 7.29 x 10(5) ng/L respectively. Simultaneously, the specific detection of the suspension microarray was excellent and did not indicate significant cross-reactions. Errors between the found and the real are in the range of 8.09% - 17.03%. It can be considered that the relative standard deviations were relatively small. Successful couplings were also directly confirmed by the observation for microstructures of the surfaces of the beads by scanning of electron microscope and laid good foundation for the following responses.</p><p><b>CONCLUSION</b>The high-throughput suspension microarray should provide a novel method for multi-analysis of the veterinary drugs and have a wide applicative prospects with simple operation, sensitive, rapid and low cost.</p>

Preparation and activity analysis of RGD-mSAK (K130T, K135R) / 生物工程学报

In order to construct RGD-mSAK mutant with reduced immunogenicity, and identify its biological activity after purification, mSAK gene fragment was amplified by over-lapping extension PCR. Then the gene was inserted into the prokaryotic expression vector pBV220 with P(R)P(L) promoters after confirmed by DNA sequencing; the expression plasmid pBV220-RGD-mSAK was constructed, and then was transformed into E. coli. DH5alpha. After temperature induction, the mutant Staphylokinase was over-expressed and much of protein was in the supernate of lysate, which is over 50% of total protein in the host. The protein was isolated and purified in Q-Sepharose FF, Sephacryl S-200 and SP, high purity protein was obtained and its purity was over 98%. The thrombolysis activity of the RGD-mSAK protein is 1.68 x 10(5) u/mg by fibrin plate assay, which is slightly higher than that of the wild-type, and antiserum titers raised against this protein in guinea pigs were much lower than those of wild-type SAK, determined by ELISA. In anti-platelets aggregation assay in vitro, the RGD-mSAK protein has obvious inhibition activity of platelet aggregation in low concentration comparing to the control group and wild-type SAK group. So the RGD-mSAK protein is a low immunogenicity, bi-function molecular with both thrombolysis activity and anti-embolism activity. It provided the basis for further research of RGD-SAK.

Differentiation of rat neural stem cells and its relationship with environment / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the differentiation fates of rat neural stem cells (NSCs) in different environmental conditions.</p><p><b>METHODS</b>NSCs derived from 16-day-old rat embryo were proliferated in vitro and implanted into the brain of rats with intra-cerebral hemorrhage. At the same time some NSCs were co-cultured in vitro with Schwann cells derived from newborn rats. MAP-2, GFAP and GalC (which are the specific markers of neural cells, astrocytes and oligodendrocytes respectively), BrdU and beta-tubulin were detected by immunohistochemical and immunofluorescent methods.</p><p><b>RESULTS</b>BrdU positive cells that were implanted into the brain distributed around the hemorrhagic area. The majority of them were GFAP positive astrocytes while a few of them were beta-tubulin positive neural cells or GalC positive oligodendrocytes. After being co-cultured with Schwann cells in vitro, NSCs are predominately shown beta-tubulin and MAP-2 positive, and only a minority of them were GFAP or GalC positive.</p><p><b>CONCLUSIONS</b>The hemorrhagic environment in vivo induces NSCs to differentiate mainly into astrocytes while co-culture with Schwann cells in vitro induce the majority of NSCs to differentiate into neural cells.</p>

Cranioplasty with Titanium mesh:110 case analysis / 中国康复理论与实践

@#Objective To evaluate the cranioplasty with Titanium mesh.Methods Clinical studies of 110 cases who accepted cranioplasty with Titanium mesh (2000-2001) were reviewed retrospectively.Results A satisfactory moulding with no complication occurred in 91%(100/110). The most common recent complication of cranioplasty with Titanium was subcutaneous hematoma(19/110); the next was epidural hematoma(3/110), intracerebral hematoma(3/110) and brain contusion(1/110). 69 cases more than 1 year after cranioplasty were followed, no one appeared long term complications such as infection, exposure or mobilization of the mending material.Conclusion The results of cranioplasty with Titanium mesh are satisfactory, the recent complications of the operation are mainly related to incompletely hemostasis, the long term complication occurred rarely.