For engineering an efficient butanol-producing Escherichia coli strain, many efforts have been paid on the known genes or pathways based on current knowledge. However, many genes in the genome could also contribute to butanol production in an unexpected way. In this work, we used Tn5 transposon to construct a mutant library including 1 196 strains in a previously engineered butanol-producing E. coli strain. To screen the strains with improved titer of butanol production, we developed a high-throughput method for pyruvate detection based on dinitrophenylhydrazine reaction using 96-well microplate reader, because pyruvate is the precursor of butanol and its concentration is inversely correlated with butanol in the fermentation broth. Using this method, we successfully screened three mutants with increased butanol titer. The insertion sites of Tn5 transposon was in the ORFs of pykA, tdk, and cadC by inverse PCR and sequencing. These found genes would be efficient targets for further strain improvement. And the genome scanning strategy described here will be helpful for other microbial cell factory construction.
Butanols ; chemistry ; DNA Transposable Elements ; Escherichia coli ; metabolism ; Fermentation ; Gene Library ; Hydrazines ; Industrial Microbiology ; Mutagenesis ; Open Reading Frames ; Organisms, Genetically Modified ; Polymerase Chain Reaction ; Pyruvic Acid ; chemistry

Objective To investigate the expression and significance of MMP-3 in knee joint synovium of different stage in osteoarthritis (OA) patients. Methods MMP-3 protein were detected by immunohistochemical method in knee synovial tissues from 90 OA patients (the OA group) and OA group was divided into 3 subgroups according to Kellgren and LawrenceX-ray diagnosing standards: the gradeⅠ(n = 30), gradeⅡ (n = 30) and grade Ⅲ subgroups (n = 30). 30 patients were enrolled as control group. Immunohistochemistry was used to detect the expression of MMP-3 protein in the tissue. Results The expression level of MMP-3 protein in OA group was significantly higher that in the normal synovium (P < 0.05). There existed significant difference in the expression of MMP-3 protein between the grade Ⅲ subgroup and the gradeⅠ, or Ⅱsubgroups (P < 0.05). The expression of MMP-3 protein related positively to the severity of OA (r = 0.912, P < 0.05). Conclusion The expression of MMP-3 protein related closely to the pathogenic mechanism of OA. It may serve as an important indicator of early diagnosis and the activity of OA.

Background and purpose: Trichostatin A (TSA), an antifungal antibiotic with cytostatic and differentiating properties in mammalian cell culture, is a potent and specific inhibitor of histone deacetylase (HDAC). This study was aimed to investigate the influence of trichostatin A on the growth of human lung adenocacinoma cells in vitro, and to explore the mechanisms involved. Methods: MTT assay was employed to evaluate the inhibitory effect of TSA (0.1, 0.2,0.4 μmol/L) on the growth of human NCI-H1299 cancer cells. The cell cycle distribution and apoptotic ratio were determined by flow cytometry. The acetyl level of histone H4 after TSA treatment was detected by Western blot;the mRNA level of Bax,Bcl-2,p21 and cyelinBl was measured by Real-time PCR. Results: TSA inhibited the growth of NCI-H1299 cells in a dose-and time-dependent manner. Flow cytometry showed that the cells were blocked at G_2/M phase and cell apoptosis was increased compared to the control. TSA significantly increased the acetyl level of histone H4, induced p21 and Bax expression, and inhibited the expression of cyclin BI and Bcl-2. Conclusion: TSA inhibits the growth of lung cancer cells in vitro through inducing cell apoptosis and cell cycle arrest, which might be related to its regulatory effects on the acetyl blot of histone and the expression of p21, Bax, Bcl-2 and cyclinBl.

At present, the existing problem in nasal feeding perfusion apparatus is laborious and instability. Designing the rolling type perfusion apparatus by using a roller pump, the problem is solved. Compared with the traditional perfusion apparatus, the advantage lies in liquid carrying only need once and simulating human swallowing process. Through testing and verification, the apparatus can be used in nasal feeding perfusion for elderly or patients.
Aged ; Enteral Nutrition ; instrumentation ; Humans ; Nose ; Surgical Tape

Clostridium acetobutylicum, a biofuel-butanol producer, has attracted worldwide interests. Strain improvement is important for the process of biobutanol industrialization where efficient genetic modification systems are essential. In this review, the history of genetic modification systems of C. acetobutylicum was introduced, and the types and principles of these systems and their disadvantages are summarized and analysed. The development of updated genetic modification systems for C. acetobutylicum is also proposed.
Biofuels ; Butanols ; analysis ; metabolism ; Clostridium acetobutylicum ; genetics ; Gene Expression Regulation, Bacterial ; Genetic Engineering ; Genetic Techniques

Objective To investigate the iodine nutritional status,thyroid function and the prevalence of thyroid nodules of residents using non-iodized salt in Ningbo City,Zhejiang Province.Methods In 2011,using typical sampling method,6 villages/communities consumption of non-iodized salt were selected as study fields and residents aged 6-70 were selected as study subjects in Ningbo.Urinary iodine detection,thyroid ultrasound examination and tests of thyroid function [free triiodothyronine (FT3),free thyroxine (FT4),thyroid stimulating hormone (TSH),thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb)] were performed in all participants.Urinary iodine concentration (UIC) was determined by arsenic cerium catalytic spectrophotometry,and thyroid function was monitored by chemiluminescence method.Results A total of 1 177 residents agreed to participate in the study,482 were male,and 695 were female (including 2 pregnant women).The participants' mean age was (48.54 ± 13.98) years.The median UIC in all participants was 90.36 μg/L,and the proportions with a UIC ＜ 100μg/L was 56.07％ (660/1 177).Furthermore,the median UIC in male was 97.05 μg/L and in female was 83.84 μg/L,there was a significant difference in UICs between male and female (Z =-2.99,P ＜ 0.05).Similarly,significant difference in UICs was observed among age groups (x2 =99.34,P ＜ 0.01).Among the participants,19.88％ had thyroid nodules,with standardized prevalence rate of 13.95％.Furthermore,in male,11.83％ had thyroid nodules,with standardized prevalence rate of 8.11％,and in female was 25.47％,with standardized prevalence rate of 19.83％,there was a significant difference in the detection rate of thyroid nodules between male and female (x2 =33.25,P ＜ 0.01).Likewise,significant difference in the detection rate of thyroid nodules was observed among age groups (x2=49.65,P＜ 0.01),and there was a positive and significant correlation between the detection rate of thyroid nodules and increasing age (x2trend =44.22,P ＜ 0.01).Conclusions The residents who using non-iodized salt in Ningbo City are in the status of iodine deficiency.The detection rate of thyroid nodules is higher in female than in male and it has increased with age.

Objective To evaluate the effects of leptin on brain injury and long-term cognitive function in rats undergoing orthotopic liver transplantation. Methods Ninety clean-grade male Sprague-Dawley rats, aged 3 months, weighing 200-250 g, were divided into 3 groups by a random number table method: sham operation group ( S group) , liver ischemia-reperfusion ( I∕R) group ( I∕R group) and lep-tin group ( L group) , with 18 rats in each group. Orthotopic liver transplantation was performed to estab-lish the model of liver I∕R injury in I∕R and L groups. Leptin 1 mg∕kg was intraperitoneally injected at the onset of ischemia in L group, and the equal volume of normal saline was given instead of leptin in S and I∕R groups. Twelve rats in each group were sacrificed at 3 days after operation, and brains were removed for ex-amination of the pathological changes in hippocampal CA1 region ( with a light microscope) and for determi-nation of apoptosis in hippocampal neurons ( by TUNEL assay) and expression of aquaporin 4 ( AQP4) and protein kinase C ( PKC) in the hippocampus ( by Western blot) . The apoptosis rate was calculated. The remaining 6 rats in each group underwent a Morris water maze test at 30 days after surgery to evaluate long-term cognitive function. Results Compared with S group, the apoptosis rate of hippocampal neurons was significantly increased, the expression of AQP4 and PKC was up-regulated, the escape latency was pro-longed, and the time of staying at the platform quadrant was shortened in I∕R and L groups (P<0. 05). Compared with I∕R group, the apoptosis rate of hippocampal neurons was significantly decreased, the ex-pression of AQP4 and PKC was down-regulated, the escape latency was shortened, and the time of staying at the platform quadrant was prolonged in L group (P<0. 05). Conclusion Leptin can reduce the brain damage in rats undergoing orthotopic liver transplantation, the mechanism may be related to down-regulating the expression of PKC and AQP4, and leptin can also improve long-term cognitive function after orthotopic liver transplantation in rats.

The paper analyzes the current status and existing problems of citation retrieval work, puts forward the design principle, overall structure and function of cited references integration tools, demonstrates the key technologies of system realization.An integrated retrieval platform for online literature citations is constructed for the following functions:one-stop retrieval of various citation databases, automatic removal of duplications, so as to reduce the burden of staffs and improve efficiency effectively.

Objective To investigate the prevalence of thyroid nodules among residents of Ningbo City and to explore the risk factors for thyroid nodules.Methods Totally 3 596 residents aged 6-70 were selected by multistage stratified cluster random sampling in Ningbo City,2011.Thyroid ultrasound examination was performed in all participants,while salt iodine and urinary iodine were measured.Possible risk factors for thyroid nodules were analyzed by single factor and multi-factor logistic regression.Results The prevalence rate of thyroid nodules in residents of Ningbo City was 22.66％ (815/3 596),with standardized prevalence rate of 17.69％.Female [(odds ratio (OR) =2.06,95％ confidence interval (CI) =1.74-2.43],groups of aged 18-(OR =3.42,95％ CI =1.22-9.61),aged 40-(OR =13.06,95％ CI =4.80-35.51),aged 65-(OR =16.67,95％ CI =5.97-46.54) and occasional consumption of seafood habits (less than twice per week,OR =1.23,95％ CI =1.02-1.49) were significant associated with thyroid nodules.Conclusions There is no link Letween iodine nutrition and thyroid nodules.It is demonstrated that female and aged ≥ 18 groups have higher risk of thyroid nodules; frequent consumption of seafood seems to be a protective factor.

Objective To develop a spatio-temporal model of mountainous Oncomelania hupensis snails based on the Bayes-ian model,and to analyze and identify the spatio-temporal pattern at a village scale. Methods The data including the intensity and spatial distribution of live and infected snails from 2000 to 2006 and the village boundary were collected. The independent and interactive spatio-temporal models were established,and then the best fitness model was selected to analyze the spatio-temporal pattern of live and infected snails. Results The interactive model of live snails and the independent model of infected snails were relative fitness models,and the models showed 95%CI(confidence interval)of the spatial and temporal coefficient included ze-ro,and indicated that the spatial and temporal correlation of live and infected snails was not significant at a village scale. Conclu-sion There is no significant spatial and temporal correlation of live and infected mountainous snails at a village scale,and the fur-thermore study should be carried out at a small scale.