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 study the positive rates of oligoclonal bands(OCB)and the IgG index in patients with multiple sclerosis(MS)and in other nervous system disorders(OND).Methods Cerebrospinal fluid(CSF)and serum were collected from 54 patients with MS,271 patients with OND including 62 patients with infections of central nervous system and 209 patients with non-infections.The OCB and IgG index of CSF and serum were detected.Results The positive rate of OCB was 35.2% in MS,8.9% in OND(P<0.05),in which 24.2% in infections of central nervous system(P>0.05),4.5% in non-infections of central nervous system.The positive rate of IgG index was 83.3% in MS,78.2% in OND(P>0.05).Conclusion OCB is helpful to diagnose MS if infection diseases have be excluded,while IgG index can be referenced.

Objective; To evaluate the effects of gingival shade guide in visual shade-matching in vitro models. Methods; 42 tabs of Shofu NCC shade guide were adopted for color measuring. Each tab was fixed in the middle of Gingiva-Indicator, Guray(1,2,3,4) respectively and located in a black box. The measurements were made using the Shadepilot instrument. The color parameters ( CIE1976L * a * b * ) of cervical, body, incisal area of each tab were recorded. The color difference A E value in the same position of each tab was calculated between non-gingival shade guide group and Gumyl ,2,3,4 groups with Shadepilot software. Results; The AE value in the same position of 42 tabs between non-gingival shade guide group and 4 gingival shade guide groups were; cervical (2.93±0.79)NBS,body(0.51±0.27)NBS and incisal(0.61 ±0.29)NBS. In the cervical, body and incisal area, there was no statistically difference among Gumyl ,2,3,4 groups on affecting shade of tabs(P >0. 05). Conclusion; The gingival color has an effect on the cervical shade of tabs, and it can be recognized by human eyes, while gingival color has little effect on the shade of body and incisal area.

Background and purpose:Metformin is known to be an insulin sensitization agent and is a fi rst line treatment for patients with type 2 diabetes. Recent clinical studies have revealed that metformin treatment has been associated with reduced cancer risk,which indicated that metformin may be a potential anti-neoplastic agent. We investigated the effects of antidiabetic drug metformin on proliferation and apoptosis in human lung adenocarcinoma cell line A549 in vitro and explored the possible underlying mechanisms. Methods:A549 cells were treated with 0.5 mmol/L,2 mmol/L and 8 mmol/L metformin for 48 hrs. Growth inhibition rates of the cells were measured by MTT assay. Cell apoptosis were detected by ? ow cytometery(FCM). Expressions of three genes including p53,Bcl-2 and Bax mRNA in the cells were measured by Real-Time PCR. Results:The proliferation of A549 cells was inhibited by metformin in a dose-dependent manner. The Inhibition rates of metformin at dosage of 0.5 mmol/L,2 mmol/L and 8 mmol/L group were (29?5)%,(68?3)% and (84.1?2.6)%,respectively. Apoptosis was induced when the cells were treated with moderate to high concentrations of metformin.The percentage of cells in early and late stage of apoptosis was increased from (1.1?0.3)% and (1.78?0.22)% in controlled group to (2.1?0.5)% and (9?4)% in metformin 8 mmol/ L group,respectively. The expressions of p53,Bcl-2 and Bax mRNA were all up-regulated after metformin treatment while the Bcl-2/Bax ratio was signifi cantly decreased. Conclusion:Metformin can inhibit the proliferation of human adenocarcinoma cancer cell line A549 and induce cell apoptosis with moderate to high drug concentrations in vitro,which may partly be attributed to the up-regulation of p53 and down-regulation of the Bcl-2/Bax ratio.

The manuscript introduced the overview, training objectives, policy advantages, training process,curriculum, examination of the Australian College in Rural and Remote Medicine and further contrasted that with China's domestics.The authors held that Australia's training is better targeted due to its colleges tailored to this end;the training duration for general practitioners of rural and remote areas is longer,and the training schedule is reasonable;the curriculum design and training content are more targeted;and the homogeneous training is better achieved as its examination is run by the college in a standardized manner.The authors therefore hold that China should develop detailed regulations for general practitioners from rural and remote areas and explore the feasibility of setting up second-level disciplines institutes for internal medicine, surgery, gynecology and obstetrics, pediatrics and general at national and provincial level.

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 analyze the feature and cause of stumps of amputees after Wenchuan earthquake,and study the effects of rehabilitation treatment for stumps.Methods Fifty-two cases with stump limbs post-amputation were evaluated,including stump skin status,stump shape,stump length,stump swelling,range of motion (ROM)of joint and strength of stump,and were treated with physical therapy,stump moulding and kinesiotherapy.Results The incidences of stump ulcer,stump swelling,conical stump,short stump and limitation of ROM of joint in all 52 cases were 76%,73%,34%,40%and 42%respectively.After rehabilitation treatment stump ulcers healed,stump swelling eliminated;stump shape,ROM of joint and muscle strength improved obviously.All poor stumps could be fit with the prosthetic limb and get good function.Conclusion The incidences of poor stump limb post·amputation after earthquake were high.Rehabilitation treatment can improve the stump condition.Early comprehensive rehabilitative intervention after amputation is important for fitting the prosthetic limb tO the stump.

Objective To study the morphology of normal liver and tumors by breathing motion of hepatocellular carcinoma patients,through comparing the modified demons algorithm and FFD algorithm based on B-spline,and combing four-dimensional computed tomography (4DCT).Methods The 4DCT images of 8 HCC patients were segmented into 10-series which were named CT0,CT10 … CT80,CT90 according to the respiratory phases,CT0 and CT50 are defined to be end-inhale and end-exhale respectively.CT50 was chosen as the reference image.We used the modified demons algorithm and FFD algorithm based on B-spline to deform the images.Linear interpolation was used in both mode 1 and mode 2.The normalized mutual information (NMI),Hausdorff distance (dH) and registration speed were used to verify the registration performance.Results The average NMI for the end-inhale and end-exhale images of 8 HCC patients after demons registration in mode 1 improved 4.75％ with FFD algorithm based on B-spline(P =0.002).And the difference of dH after demons reduced 15.2％ comparing with FFD model algorithm (P =0.02).In addition,demons algorithm has the absolute advantage in registration speed(P =0.036).Conclusions The breathing movement for deformation of normal liver and tumor targets is significant.These two algorithms can achieve the registration of 4DCT images and the modified demons registration can deform 4DCT images effectively.

Objective To explore mechanical property changes of methyl vinyl silicone rubber modified by ferric nanoparticles and its dispersed phase.Methods Mechanical properties such as Shore A hardness,tensile strength,elongation at break,tearing rate of permanent deformation and tearing strength of pre-prepared ironic nanoparticle enhanced silicone rubber and carbon-coated ferric particle reinforced silicone rubber were tested according to national standards.A thermal field emission scanning electron microscope (TFE-SEM) was used to investigate the morphology of both surface and fracture of the composite materials and to observe the dispersion of ferric nanoparticles in them.Results Mean values of Shore A hardness,tensile strength,elongation at break,tearing permanent deformation rate and tear strength of modified composites increased with the increasing amounts of ferric nanoparticles,however,when the quota of ironic nanoparticles in the composite formula were greater than 17 phr,carbon-coated ferric nanoparticles more than 19 phr,the mean values of tensile strength of two composites stopped increasing and presented the declining trend.When the quota of ferric nanoparticles in the formula exceeding 15 phr,the mean values of elongation at break and tear strength began to decrease in the formula ratio of silicone rubber/ferric nanoparticles up to 85:15,while the Shore A hardness of samples increased all the way.Ferric nanoparticles dispersed evenly on the surface of composites.Nanopowder aggregation in the fracture surface of both composites could be observed at the formula ratio of 85:15 of silicone rubber/iron nanoparticle and 87:13 of silicone rubber/carbon-coated iron specimen.Conclusion Effect of iron nanapareticles and carbon-coated ferric nanoparticles on the mechanical properties of the reinforced methyl vinyl silicone rubber depends on the nanoparticle size,additive amount and agglomeration.

Objective To investigate a new method for detecting fetal cardiac arrhythmia.Methods Used two kinds of superposition:①left ventricular outflow tract color flow image with right atrium wall motion curves superposition,②left ventricular outflow tract color flow image with left ventricular inflow tract colour flow image superposition,167 cases of fetal arrhythmia were detected.Results Among them,84 fetuses with atrial premature heat,39 with ventricular premature beat,23 with temporal sinus bradycardia,12 with sinus tachycardia,4 with Ⅱ°atrioventricular block(AVB),2 with Ⅲ°AVB,3 with atrial fibrillation.Conclusions Using superposition of M-mode echocardiagraphy with color Doppler imaging to diagnose fetal cardiac arrhythmia is easier and more accurate.