AIM To compare the new methods which can be used fo r soring the stages of rat sleep. METHODS Cortical EEG and hippocampal potential(HP) were collected by implanted electrodes in freely moving rats. Gravity frequency (f g) and the complexities(Kc,C 1), were calculated. According to the characteristics of each stage and by studying the histogram of f g, Kc and C 1, the stages of rat sleep were distinguished. RESULTS The methods of f g, Kc and C 1 can distinguish the Waking, nonrapid eye movement(NREM) and REM sleep well. Comparing the results of visual and our analysis, the rate of accordance is above 85%, and the analysis based on the complexity measure is more believable than that based on the f g. CONCLUSION The gravity frequency and the complexities of Kc,C 1 can be used to distinguish the different stages of rat sleep.

OBJECTIVE To study the mechanisms of quinolones resistance in Escherichia coli.METHODS Forty E.coli clinical isolates were randomly collected from clinical specimens at the Tianjin First Central Hospital from Mar 2004 to Dec 2005.Then we detected the susceptibility to antibiotics in 40 clinical isolates of E.coli by MICs and K-B disk diffusion method.In order to investigate the mutations in the target genes,we amplified the QRDR of gyrA and parC by PCR.Later we analyzed the PCR products by single strand conformation polymorphism analysis(SSCP).In the meantime,the PCR products of marOR region were sequenced to detect the possible gene changes which contributed to the increasing expression of MarA and then lead to the Mar phenotype.RESULTS The alterations in gyrA were found in all quinolones-resistante strains.Asp87→Asn and Ala84→Pro were found besides the common amino acid alteration.The alterations in parC were found in thirty-six strains resistant to quinolones.There were no parC alterations in ECO24 which was nalidixic acid-resistant and ofloxacin/gatifloxacin-susceptible.ECO11 Which was resistant to quinolones only had no gene changes in marOR region.Six gene changes in marOR region were found in ECO5 which was resistant to mutiple antibodies.The alteration in 1879 bp changed the terminator.CONCLUSIONS The alterations in gyrA and parC are responsible for the resistant phenotypes in E.coli.That is,the alterations in the gyrA are primarily responsible for resistance to quinolones,and the alterations in the parC may play a complemental role in enhancing resistance to fluoroquinolones.Moreover,the randomly collected strains resistant to quinolones,have found some mutations in marOR.It may be play certain roles in multiple antibiotic resistance of E.coli.

OBJECTIVETo establish a method for determination of 7-ethyl-10-hydroxycamptothecin (SN-38) in microdialysates from rat brain.

METHODSThe concentrations of SN-38 were measured by LC-MS/MS method with Agilent Eclipse Plus C18 (2.1 mm ×100 mm, 1.8 μm) reversed phase column using acetonitrile-0.1% methanoic acid as mobile phase with gradient elution at a flow rate of 0.3 ml/min and temperature at 35 degree. Multiple reaction monitoring using the precursor to product ion combinations of m/z 393.1→349.1 was performed to detect SN-38 in microdialysates from rat brain.

RESULTSBlank microdialysate had non-interference. The method was linear over the concentration range of 0.1015-1015 ng/ml (r=0.9995); and the lower limit of quantification (LOQ) was 0.1015 ng/ml. The recovery of assay for SN-38 ranged from 97.54%-100.60%. The intra- and inter-day precision and stability were both well. The concentrations of SN-38 in brain microdialysates presented pharmacokinetics process and achieved the peak after 220 min.

CONCLUSIONThe fully validated LC-MS/MS analytical method has high specificity and sensibility, which can be used effectively to analyze SN-38 in microdialysates from rat brain.

Animals ; Brain Chemistry ; Camptothecin ; analogs & derivatives ; analysis ; Chromatography, Liquid ; methods ; Male ; Microdialysis ; Rats ; Rats, Sprague-Dawley ; Sensitivity and Specificity ; Tandem Mass Spectrometry ; methods

OBJECTIVETo establish the automatic X-ray cephalometric analysis system to simplify cephalometric steps and to provide a convenient and reliable method for cephalometric analysis.

METHODSThe system which was programmed by visual-c language, and graphics and image processing techniques and artificial intelligence were used. The techniques related to computer digital image processing and pattern recognition such as Median filtering, Histogram equalization, Laplacian and Canny edge detection were introduced. It could automatically outline the contour lines of the hard and soft tissues by establishing the templates of the variable anatomical structures.

RESULTSThe following functions were established: (1) automatically outlining the contour lines of the soft tissues. (2) automatically recognizing, measuring and analysing the landmarks of soft tissues. (3) automatically recognizing porion, sella and the landmarks of the mandible. (4) automatically building the contour lines of the hard tissues. In brief, the system used the more advanced methods, calculated more precisely and saved more time and energy than other systems.

CONCLUSIONThe system is a more convenient and precise tool in cephalometry.

Cephalometry ; methods ; Humans ; Image Processing, Computer-Assisted ; Jaw ; anatomy & histology ; diagnostic imaging ; Orthodontics ; methods ; Radiography ; Sensitivity and Specificity

Objective·To construct C-shaped cartilage rings by rabbit auricular cartilage-derived chondrocytes combing with both electrospun gelatin/ polycaprolactone(GT/PCL) nanofibrous membranes and 3D printed supporters for repairing tracheal cartilage defects.Methods·Primary chondrocytes were isolated from rabbit auricular cartilage with methods of trypsin enzyme digestion and collagenase enzyme digestion.After proliferation in vitro,the chondrocytes of passage 2 were harvested for further experiments.Ultrafine composite fibers of GT/PCL were fabricated via electrospinning.The electrospun GT/PCL membranes were tailored into rectangle shape,the length of which is 12 cm and the width is 2.5 cm.Chondrocytes were seeded on membrane at a density of 1 × 108 cells/mL.Then the membrane were rolled onto a 3D printed supporter of poly(DL-lactide-ε-caprolactone) (PLCL) material to construct a C-shaped cartilage-like complex.After 8 weeks of subcutaneous incubation in vivo,gross inspection and paraffin section staining were applied for evaluation.Results·After 8 weeks of culture in vivo,mature cartilage-like tissue were formed with open-cylindrical bellow appearance and pecific mechanical property.C-shaped rings arranged at regular intervals on the inner surface of tissue,which were similar to the normal structure of tracheal cartilages.Histological and immunohistological staining showed a large number of typical lacunar structures and extracellular matrix secretions.Conclusion·It is feasible to construct tissue engineered C-shaped cartilage tissue by combing chondrocytes with GT/PCL membrane and 3D printed PLCL supporter for tracheal cartilage repair.

OBJECTIVETo investigate the pharmacokinetics of Danshensu with in vivo microdialysis in freely moving rat's jugular vein.

METHODthree days after a microdialysis probe introducer was implanted into the jugular vein, a microdialysis probe was introduced to the blood vessel, and began to sample following a single intravenous injection (40 mg x kg(-1)) or a single oral dose (40 mg x kg(-1)) of Danshensu. All the samples were analyzed with HPLC. The concentration of Danshensu in blood were calculated according to the recovery of microdialysis probe and the concentration in dialysates. Pharmacokinetic parameters were than calculated with the concentration-time curve.

RESULTFor intravenous administration, t(1/2 zeta) = (69.62 +/- 33.42) min, AUC(0-infinity) = (3416.24 +/- 779.80) min x mg x L(-1), MRT(0-infinity) = (38.15 +/- 8.61) min, and for oral administration, Cmax = (7.42 +/- 3.08) mg x L(-1), tmax = (31.50 +/- 8.57) min, t(1/2 zeta) = (83.25 +/- 37.35) min, AUC(0-infinity) = (793.19 +/- 101.32) min x mg x L(-1), MRT(0-infinity) = (125.89 +/- 58.27) min. The oral bioavailability of Danshensu F = 22.56%.

CONCLUSIONIn vivo microdialysis in freely moving rat's jugular vein is a useful tool to obtain a complete set of free drug concentrations to determine reliable pharmacokinetic parameters.

Animals ; Area Under Curve ; Jugular Veins ; cytology ; metabolism ; Lactates ; pharmacokinetics ; Male ; Microdialysis ; Motor Activity ; Rats ; Rats, Sprague-Dawley

By constructing the genomic DNA library of Meiothermus ruber CBS-01, the genes of trehalose phosphate synthase (TPS) and trehalose phosphate phosphatase (TPP) involved in trehalose synthesis were cloned. The genes were cloned into the plasmid pET21a, and expressed in Escherichia coli Rosetta gami (DE3). The activities of these two purified enzymes were confirmed by thin layer chromatography (TLC). Meanwhile, we tested the cellular compatible solutes of M. ruber CBS-01 under different environmental pressure, and found that under hyperosmotic pressure, this strain can accumulate trhalose-6-phosphate, but not trehalose. These results can give more insight to future research in the roles of TPS/TPP and TreS pathway.
Bacterial Proteins ; genetics ; metabolism ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Glucosyltransferases ; genetics ; metabolism ; Phosphoric Monoester Hydrolases ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; isolation & purification ; metabolism ; Thermus ; enzymology ; genetics ; Trehalose ; biosynthesis

Objective: To explore the commonalities and differences between primary school students and teachers in beliefs of myopia prevention and control, in order to provide a theoretical basis for the education programs of myopia prevention and control. Methods: Convenient sampling method was used to select 14 students and 16 teachers from grades 3 and 4 in two elementary schools in Hangzhou for one to one in depth interviews, and the results were coded and analyzed by using Nvivo 11.0 software. Results: There were commonalities in the perceived severity, benefits and barriers of myopia prevention and control beliefs among students and teachers, and the common keywords had been mentioned for 114 times, the commonalities of perceived severity, benefits and barriers were more obvious among them; there were differences in the specific attributions of perceived susceptibility, severity and barriers among students and teachers，the difference keywords had been mentioned for 63 times, the differences of perceived susceptibility, severity and barriers were more obvious among them. Conclusion There were commonalities in the perceived susceptibility, severity, benefits and barriers of myopia prevention and control beliefs between students and teachers; there were differences in the aspects of perceived susceptibility, severity and barriers between students and teachers. Adverse health outcomes of myopia and associated prevention knowledge should be enhanced among students. schools should carry out health education activities to improve the ability of teachers and students to prevent and control myopia; the government should implement the "double reduction" policy and improve the safety insurance system for outdoor activities.

OBJECTIVE: Early bolting of Saposhnikovia divaricata has seriously hindered its medicinal value and sustainable development of resources. The molecular mechanism of bolting and flowering of S. divaricata is still unclear and worth of research. In our study, we explored the transcriptome of the genes related to the bolting and flowering of S. divaricata. METHODS: The transcriptome library was constructed, sequenced, assembled and annotated from the bolting and unbolting leaves of S. divaricata by high-throughput sequencing at the bud and flowering stage. Focus on the pathways related to bolting and flowering in plants, and exploring genes. The expression of seven candidate genes was verified by real-time fluorescence quantitative PCR (qRT-PCR). RESULTS: Transcriptome results showed that 249 889 422 high-quality clean reads were obtained. A total of 67 866 unigenes were assembled with an average length of 948.1 bp. Trinity de Novo assembly produced 67 866 unigenes with an average length of 948.1 bp. Among 993 differentially expressed genes, 484 genes were significantly up-regulated and 509 genes were down-regulated in the SdM group. A total of 79 GO terms were significantly enriched for differentially expressed genes. KEGG results showed that 11 154 unigenes were enriched in 89 pathways. And 21 candidate genes related to bolting and flowering of S. divaricata were excavated. The qRT-PCR results showed that expression trends of HDA9, PHYB, AP2, TIR1, Hsp90, CaM, and IAA7 were consistent with transcriptomic sequencing results. In addition, RNA-seq had identified 10 740 transcription factors and classified them into 58 families by their conserved domains. Further studies showed that the transcription factors regulating the flowering of S. divaricata were mainly distributed in the NAC, MYB_related, HB-other, ARF, and AP2 families. CONCLUSION Based on the results of this study, it was found that the plant hormone signal transduction pathway was one of the decisive factors to control bolting and flowering. Among them, auxin related genes IAA and TIR1 are the key genes in the bolting and flowering process of S. divaricata.

As the main factor leading to foodborne illnesses, foodborne pathogens have been attached great importance by people. The development of simple, rapid, high-sensitivity and low-cost food-borne pathogen detection methods is of great significance in reducing the incidence of foodborne diseases. Biosensor technology is a new micro-analysis technology developed by multi-disciplinary cross-infiltration. It has the characteristics of high sensitivity and fast analysis speed, and is widely used in the detection of food-borne pathogens. This paper introduces the basic principles of biosensors, summarizes the application of common biosensors in the detection of foodborne pathogens, and prospects for future development.
Biosensing Techniques ; Food Microbiology ; Foodborne Diseases ; Humans