Digital X-ray photography has been applied to clinical medicine in recent 3years.This paper introduces the development situation of the flat detectors for digital X-ray photography.The technical indexes and structure differences of the detectors are presented in this paper.

The paper is aimed to study the enzymatic hydrolysis of the activatable cell-penetrating peptide (ACPP) that was designed and synthesized. The ACPP was composed of three parts, polyanionic sequence peptide, peptide sequence that specifically cleaved by matrix metalloproteinase (MMP) and cell penetrating peptide (CPP). The ACPP was hydrolyzed by type IV collagenase (MMP-2/9) under the condition of 37 degrees C and was monitored by reversed-phase high performance liquid chromatography (RP-HPLC). The efflux of peak was collected and detected by matrix assisted laser desorption ionization orthogonal time of flight mass spectrometry (MALDIO-TOF-MS) to speculate the sequences of the peptide fragments. The results indicated that the ACPP could be cleaved by type IV collagenase at target site as predicted, released CPP. The half life of the cleavage was about 4 h. Meanwhile, the peptide fragments may be cleaved again at other sites by type IV collagenase.

Objective To observe the biomechanics of the anterior and posterior interosseous talo-calcaneal ligaments (ITCLs) . Methods Load-displacement characteristics of the subtalar joint were studied in 12 cadaver specimens whose ankle joints were mutilated. The ankle articular surfaces of the talus and the post-calcaneus were exposed. Bone blocks were then embedded in polymethylmethacrylate. The an-terior ITCLs were abscised in 6 of them, and the posterior ITCLs in the other 6. A multi-functional biome-chanical machine was used to perform the biomechanical tests on the specimens. Results When the anterior ITCLs were cut, the tali moved to the anterior-lateral side. When the posterior ITCLs were cut, the tali mostly moved to the anterior-interior side. Conclusions The anterior and posterior ITCLs have dif-ferent roles in maintaining stability of the subtalar joint. Since the posterior ITCLs seem more important than the anterior ones, they should have priority in ITCL reconstruction.

Objective: Introduce Internet and wireless communication technology into radiology image remote diagnosis system, develop a new system combined with PACS. Material and Methods: Used ASP.NET technology under VS. NET2005, and used JAVA to develop the image APPLET, Web server used 11S5.0, database used Microsoft SQL Server. Also need a SMS Modern to send message online. Results: Offer two ways to access medical image remote diagnosis system: Interact and wireless networks. Wherever a doctor he is, as long as has a computer or mobile phones can be connected to Interact or wireless network, can login diagnosis system, browse the patients' images, do some image processing, and also can send reports. Conclusions: The system can be put into practice, lifting the restrictions in time and place of remote diagnosis system, it try in full-development of telemedicine. Although at present reports of this form does not have legal effectiveness, this paper provided a new idea for development of medical image remote diagnosis system.

Objective To design a new X-ray sensor of iono-chamber type to achieve automatic exposure control(AEC) of the X-ray machine. Methods We designed the chamber acording to the ionization theory and the requirements of automatic exposure control. Results (1) The device had double-negative poles, so the distance between positive and negative poles was 1/2 shorter and its test-volume was equal to odd-negative pole. (2)It had good property of electromagnetism-resistance because of the double shielded design by double-negative poles and screen-rings.(3) Iono-chamber was made of low-density material, so it had low absorb-ratio of X-ray and could not form image on film. Conclusion The property of the device was steady and reliable. It had applying and spreading value.

Cyclic amp receptor protein (CRP) is a global transcriptional factor in many prokaryotes, capable of governing nearly half of the total genes in Escherichia coli. Through the method of error-prone PCR or DNA shuffling, we can first obtain CRP mutant library and then get the expected cell phenotype with enhanced resistance. In this article, we reviewed the following desired phenotype: enhanced tolerance towards oxidative stress, improved osmotolerance, enhanced organic solvent (toluene) tolerance, improved acetate tolerance of E. coli fermentation and improved ethanol tolerance during bio-ethanol production. We then concluded that CRP can also be applied in other host cells to get desired phenotypes. Last, we predicted potential applications of mutant CRP transcriptional factor.
Cyclic AMP Receptor Protein ; biosynthesis ; DNA Shuffling ; Escherichia coli ; metabolism ; Fermentation ; Metabolic Engineering

In order to construct a recombinant plasmid containing short hairpin RNA (shRNA) targeting survivin and to investigate its effect on survivin expression and cell apoptosis of human retinoblastoma cell line Hxo-rb44 in vitro, RNA interference plasmid pSIRENS that can express shRNA of survivin was designed, constructed, and transfected into human retinoblastoma cell line Hxo-rb44. Survivin and c-Myc expression was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Apoptosis of Hxo-rb44 cells was assayed by Honchest33258 staining and cell growth curve was drawn. The results showed that the oligonucleotide targeting survivin was identified in pSIRENS plasmid. After pSIRENS plasmid transfected, survivin and c-Myc expression in Hxo-rb44 cells was decreased significantly. Apoptotic rate of cells was up-regulated from (3.5+/-1.29) % to (36.1+/-19.66) %. The proliferation ability of Hxo-rb44 cells was inhibited. No significant effects on survivin expression and apoptosis of the cells were found when negative control plasmid was transfected. In conclusion, the plasmid containing shRNA targeting survivin was constructed successfully. It could inhibit efficiently the expression of survivin and c-Myc in human retinoblastoma cell Hxo-rb44 in vitro. The inhibition of the expression of c-Myc might be involved in the apoptosis of Hxo-rb44 cells.

Objective To evaluate the ability of showing the pancreatic diseases on various MRI sequences. Methods Eighty-four subjects included 50 normal individuals and 34 patients(22 patients investigated for pancreatic neoplasia and 12 pancreatitis) were presented. The MR protocol included conventional SE T1WI, FSE T2WI, Pre-and post-contrast T1-weighted fat-suppressed and GRE imaging. Results The best diagnostic information was provided by T1-weighted fatsuppressed imaging before and after gadolinium enhancement on 27 of 34 cases with abnormal pan creas, followed by immediately postcontrast GRE images. Precontrast GRE imaging better showed the features of a cute pancreatitis. FSE T2WI obviously exhibited islet cell tumor and metastases of liver from pancreatic adenocarcino ma. Conclusion The standard MR protocol included T1-weighted fat-suppressed image and dynamic GRE imaging.

Objective To investigate the expression of TMS1/ASC gene induced by gemcitabine(GEM) in pancreatic carcinoma cell line PANC-1.To study the relationship between cysteine aspartase(caspase-1),nuclear factor-κB(NF-κB) and the expression of TMS1/ASC.Methods The pancreatic carcinoma cell line PANC-1 was cultured in Dnlbecco's modification of Eagle's medium(DMEM).Methyl thiazolyl tetrazolium (MTT)method was used to measure the effect of GEM at different time points(24,48 h)at different concentrations(1,2,4,8,16 μg/ml) on growth of PANC-l.RT-PCR was used to detect the expression of TMS1/ASC mRNA stimulated by medium alone and by GEM(4.27μg/ml)for 24 h and 48 h.Western blot analysis was performed with inhibitory protein of NF-κB multiclonal antibody,caspase-1 multiclonal antibody and β-actin monoclonal antibody to observe the expression of β-actin,caspase-1 and IκBα in GEM group and in the control group.The activation state of caspase-1 and NF-κB was examined.Results GEM inhibited the growth of PANC-1 cells in a concentrationand-time-dependent manners and its half maximal inhibitory concentration(IC50)was 4.27 μg/ml on 24 h.The expression of TMS1/ASC was 0.3 ±0.004 and 0.63 ±0.007 respectively in GEM group while it was 0.1 ±0.001 and 0.21 ± 0.006 in the control group on 24h and 48h.The difference between the 2 groups at the same time point had statistical significance (P ＜ 0.01).Western blot showed that GEM caused the activation of caspase-1.The expression of IκBα had no obvious differencebetween the 2 groups.GEM couldn't induce the activation of NF-κB.Conclusions GEM can inhibit proliferation of PANC-1 cells and induce their apoptosis.The drug sensitivity decreased with prolongation of exposure time.GEM might induce and increase the expression of TMS1/ASC,which might influence the apoptosis of the cells later.The apoptosis of PANC-1 cells induced by GEM is dependent of caspase-1 signaling pathway and independent of NF-κB signaling pathway.