Cofactor engineering, a vital part of metabolism engineering, changes the redox cofactor regeneration approach. Its main goal is to rebuild the components of metabolic products. The bioconversion of xylose for the production of ethanol is being studied intensively because ethanol is an alternative energy source and a potential liquid fuel. Saccharomyces cerevisiae has been traditionally used in producing ethanol from fermentable sugars but it cannot utilize xylose, only its isomer xylulose. Introduction of the xylose fermentation pathway from Pichia stipitis into S. cerevisiae enables xylose utilization in recombinant S. cerevisiae, but the ethanol yields of xylose fermentation with recombinant S. cerevisiae has been low and large amounts of the byproduct xylitol are produced. The major reason is that the catabolism of xylose with the fungal pathway leads an imbalance of redox cofactor. The process of the catabolism of xylose requires NADPH and NAD~+, both of which have to be regenerated in separated processes. More and more attention has therefore focused on the redox cofactor balance in S. cerevisia. The research progress of cofactor engineering to solve the imbalance of redox cofactor in xylose metabolism recombinant S. cerevisiae was introduced. This included expression of transhydrogenase, increasing the utilization of NADPH, and achieving the anaerobic reoxidation of NADH. Reversing the cofactor specificity of enzymes is another effective way.

Carcinoma in Situ ; pathology ; Colorectal Neoplasms ; pathology ; Humans ; Lymphatic Metastasis ; Rectum ; pathology

Objective To evaluate the damage to the brochial plexus produced by pulsed radiofrequency (PRF)and radiofrequency thermocoagulation(RFTC).Methods Fifty-five male Wistar rats weighing 250-300 g were randomly divided into 3 groups:groupⅠPRF(n=25):groupⅡRFTC(n=25)and groupⅢnormal control(n=5).The animals were anesthetized with intraperitoneal chloral hydrate.The left brochial plexus was exposed and PRF or RFTC was applied to the left brochial plexus.The voltage and current of the minimal stimulation which elecited muscle twitching and the impedance before and after operation were recorded in group PRF and RFTC.The nerve function was scored according to Tarloo(0=flaccid paresis,5=normal gait)before and at 3d after operation.The animals were killed and the left brachial plexus was removed immediately and at 1, 7,14,30 d after operation(n=5 at each time point)for determination of histopathological changes using microscope.Results The impedance and Tarlov score were significantly decreased after operation as compared to the baseline values before operation in group RFTC and were also significantly lower than in group PRF. Microscopic examination showed that the myelinated nerve fibers exhibited Wallerian degeneration and axon regeneration and the cytochondria in cylindraxile were severely injured or disappeared in group RFTC.The myelinated nerve fibers and the cytochondria in cylindraxile were significantly less injured after operation in group PRF than in group RFTC and returned to normal at 7 d and 30 d respectively.Conclusion The injury to brachial plexus produced by PRF is slighter than that produced by RFTC.

Objective To construct PPAR?and PPAR?response element (PPRE)-controlled luciferase expression vectors,and to determine whether the traditional Chinese medicine emodin activates PPAR?and improves the glucose uptake by HepG2 hepatocytes.Methods (1) PPAR?and PPRE luciferase expression vectors were constructed and were applied to screen more than 20 ingredients of the traditional Chinese medicine. (2) HepG2 cells were incubated with emodin which can activate PPAR?and PPRE luciferase activity,and the PPAR?mRNA expression level was evaluated by RT-PCR/Southern blot.(3) PPAR?and glucose transporter 2 (Glut2) proteins were determined by Western blot analysis in HepG2 cells treated with emodin.(4) The glucose uptake rate was measured using 2-deoxy-[~3H]-D-glucose in HepG2 cells after treatment with emodin.Results (1) Emodin stimulated luciferase activity controlled by PPRE in dose-dependent manner at concentrations of 0.04 to 180?mol/L in COS-7 cells.The highest value was about 4 folds of control in the cells treated with 90?mol/L emodin (P

Three primer were designed based on the consevered area of the genetic of the ATCC VR-2332 strain and LV strain. And the nest RT-PCR of testing porcine reproductive and respiratory syndrome virus were developed. The nest RT-PCR against ATCC VR-2332 strain, LV strain and B13 strain were done by this method.The DNA fragment were obtained specially from the three strains isolated from different region. The size were 430bp (430bp) , 410bp (413bp) and 410 bp (413bp) separately. But the DNA fragment were not obtained from HCV, PPV and PRV. Its sensitivity was 10-2 TCID50. It's sensitivity increased 10000 times than one step RT-PCR. It should make the method of testing porcine reproductive and respiratory syndrome virus more sensitive, fast and accurate.

A nest RT-PCR/restriction test has been developed in order to distinguish the lapinised vaccine strain from field isolates of classical swine fever virus. The restriction enzyme cut sites mapping of the major coding sequence of E2 gene lapinised vaccine strain and ShiMen strain of classical swine fever virus have been compared. Ten and sixteen unique restriction markers have been found in the lapinised vaccine strain and ShiMen strain. The restriction enzyme cut sites mapping of the twenty six unique restriction marker in the major coding sequence of E2 gene of 17 classical swine fever field isolates have been analyzed. Only 3 sites (HgaI、Hin8I及Hsp92I) are present in the lapinised vaccine strain sequence. Two pans of nested primers and a criteria of analysis have been designed for HgaI restriction marker site. The tests have been conducted first on the lapinised vaccine strain and ShiMen strain of classical swine fever virus resulting in predicted restrection patterns. Finally, the tests have been applied to 5 field isolates of different gene group analyzed by phylogenetic study. The result showed that only HCLV strain gene can be cut to 2 fragment by Hgal , and ShiMen strain and 5 field isolates cant be cut At the same time the sensitivity and specificity of nest RT-PCR have been tested. The sensitivity is 0. 2MLD. The specific fragment of BDV and BVDV were not obtained by the nest RT-PCR. These results showed that the development of the nest RT-PCR/restriction tests is very important for the control and perish of classical swine fever in china.

Objective To investigate the mechanism of fluoroquinolone resistance in clinical isolates of Enterococcus faecium. Methods The MICs of six fluoroquinolones(norfloxacin,ciprofloxacin,ofloxacin,levofloxacin,gatifloxacin and moxifloxacin) against 35 clinical isolates of E.faecium from eight hospitals in Tianjin were determined by agar dilution method in the absence or presence of multidrug resistance efflux pump inhibitor reserpine.The quinolone-resistance determining region(QRDR)of parC and gyrA were amplified and sequenced.Results No less than twofold decrease in MIC values of the six fluoroquinolones in the presence of reserpine was observed in 35,29,1,0,6 and 2 of the 35 strains of E.faecium respectively.One fluoro- quinolone-susceptible isolate and five fluoroquinolone-resistant isolates were selected randomly to analyze the QRDR of parC and gyrA.All five fluoroquinolone-resistant isolates had single amino acid alteration in both GyrA and ParC.Ser-80 in ParC was substituted by lie(4 isolates)or Arg(1 isolates).Glu-87 in GyrA was replaced by Lys(2 isolates)or Gly(2 isolates). The other one had an Ser-83-to-Ile substitution.The one fluoroquinolone-suseeptible isolate had no alteration in the QRDR of either ParC or GyrA.Conclusions Both target alteration and active efflux are responsible for the resistance to fluoroquinolone in clinical isolates of E.faecium.

Objective To examine the neural basis of item memory and source memory with fMRI approach.Methods Eight male and eight female healthy fight-handed native Chinese speakers were involved in this study.The item memory and source memory task were conducted with 504 highly frequent Chinese double-character words in the Block-designed experiment.Participants underwent such a double- round procedure as fMRI scanning following study.The fMRI data collected from a GE 1.5T MRI system were analyzed to generate corresponding activation maps for females and males respectively(P20)using statistical parametric mapping software(SPM).Results For females,item memory task activated the bilateral dorsolateral prefrontal cortex(BA6,the number of activated voxel clusters was 62 or 11 in the left and the right,respectively),source memory more activated the left dorsolateral prefrontal cortex(BA6/46,the number was 59).For males,item memory activated the right dorsolateral prefrontal cortex(BA6/46,the number was 64),source memory activated the bilateral dorsolateral prefrontal cortex(BA6,9 and 40 in the left and the right).Conclusion On the neural basis of item or source memory,there exists dissociation,which is that right dorsolateral prefrontal areas are more activated by item memory while left dorsolateral prefrontal areas by source memory.For the difference of gender,it is suggested that left dorsolateral prefrontal areas(BA6/46)are more activated in females while right dorsolateral prefrontal cortex(BA6/46)more in males.

This paper introduces the nursing care of two children with type 1 diabetes during continuous glucose monitoring. In addition to psychological care,diet instruction and insulin therapy,the nurses actively communicated with the children and their parents,introduced the principle and advantages of continuous glucose monitoring system (CGMS) to promote the children and parents to cooperate with the medical staff. Moreover,the insert site of CGMS was changed from inferior abdomen to up-per lateral buttock according to the physiological character of children. As a result,the CGMS was completed successfully in the 2 eases,which provided reliable reference for the regulation of treatment plan.

AIM: To evaluate the safety, efficacy and stability of posterior chamber phakic intraocular lens ( ICL ) implanation and clear lens extraction for the correction of high myopia.
METHODS: The study enrolled 56 cases ( 100 eyes ) of high myopia. Group I comprised 32 cases ( 58 eyes ) receiving ICL implantation and Group II comprised 24 cases (42 eyes) undergoing clear lens extraction. In this study, we evaluated the two groups of subject's the visual and refractive results, intraocular pressure ( IOP ) , endothelial cell density ( ECD ) , anterior chamber depth ( ACD) , lens transparency, the surgical complications as well as visual adverse symptoms before and after surgery.
RESULTS: The postoperative subjects in group I and group II were followed, uncorrected vision acuity ( UCVA)>0. 5 were 69. 0% in group I and 71. 4% in group II after 3mo. UCVA>0. 5 were 72. 4% in group I and 73. 8% in group II after 1a. Predictability of the manifest spherical equivalent refraction within±1. 00D was achieved in 62. 1%of eyes in group I and 57. 1% in group II after 1a. The central vault of the ICL ( distance from posterior surface of ICL to the crystalline lens ) measured with anterior segment optical coherence tomography ( AS-OCT ) was 0. 35-0. 54 (0. 40±0. 16) mm. Twelve point one percent of eyes in group I and 7. 1% of eyes in group II had transient mild increase in IOP. Here were statistically significant differences between preoperative and postoperative ECD (P<0. 001 ). Complications of surgery: 1 eye had ICL spontaneous rotation, 2 eyes had anterior subcapsular cataract, 4 eyes noticed halos around lights at night in group I. Three eyes had posterior capsule mild opacification, 3 eyes noticed halos around lights at night, 12 eyes had difficulty in near vision in group II.
CONCLUSION: ICL implantation and clear lens extraction are effective, safe and predictable surgical option for the management of high myopia. No severe complications occurred, but its long time effect and safety still need more time to prove.