1.Progresses of TGF-β-Smad signaling pathways and epithelial-mesenchymal transition in stented blood vessel stenosis
Chinese Journal of Interventional Imaging and Therapy 2017;14(3):182-185
There is a high risk of re-stenosis after implanting blood vessels stent,the processes involves the transforming growth factor-β (TGF-β)-Smad signaling pathways,epithelial-mesenchymal transition (EMT) and so on.The function of TGF-β-Smad signal pathways and EMT in vascular stent re-stenosis and the relevant mechanism were reviewed in this paper.
2.Advances in parallel artificial membrane permeability assay and its applications.
Yifan WU ; Hui LIU ; Jingman NI
Acta Pharmaceutica Sinica 2011;46(8):890-5
With the development of drug discovery, more and more candidate compounds need to be studied. Methods that can screen compound rapidly received significant attention. Parallel artificial membrane permeability assay (PAMPA) as a powerful tool has been applied to drug studies. It uses an artificial lipid membrane to mimic the barrier for drug permeability studies. This article introduces the establishment and characteristics of PAMPA, as well as its applications in screening compounds. It can be used as models (e.g. predicting the ability of compound in gastro-intestinal absorption, blood-brain barrier transportation and skin penetration) by changing the component of artificial lipid membrane. PAMPA has advantages in high throughput selection of valuable compound with low cost, versatile, low dose, and good reproducibility.
3.DATA ANALYSIS OF RADIORECEPTOR ASSAY WITH MICROCOMPUTER
Jiang LIU ; Yifan FU ; Xiawen WANG
Journal of Chongqing Medical University 1987;0(01):-
A BASIC program was written to analyse the data from radioreceptor assay by microcomputer. Concentrations of ligand, total binding, nonspecific binding, specific binding and the ratio of specific binding (number of receptor sites) to free ligand content were calculated for each point. The receptor binding affinity constant and binding capacity were obtained by Sca-tchard analysis. Results and graphs can be displayed on the screen and/ or printed out by using a graphic printer
4.The study of the colorimetric characteristics of the cobalt-chrome alloys abutments covered by four different all-ceramic crowns by using dental spectrophotometer.
Yifan CHEN ; Hongchun LIU ; Yukun MENG ; Yonglie CHAO ; Changhong LIU
West China Journal of Stomatology 2015;33(3):226-229
OBJECTIVEThis study aims to evaluate the optical data of the different sites of the cobalt-chrome (Co-Cr) alloy abutments covered by four different all-ceramic crowns and the color difference between the crowns and target tab using a digital dental spectrophotometer.
METHODSTen Co-Cr alloy abutments were made and tried in four different groups of all-ceramic crowns, namely, Procera aluminia, Procera zirconia, Lava zirconia (Lava-Zir), and IPS E.max glass-ceramic lithium disilicate-reinforced monolithic. The color data of the cervical, body, and incisal sites of the samples were recorded and analyzed by dental spectrophotometer. The CIE L*, a*, b* values were again measured after veneering. The color difference between the abutments covered by all-ceramic crowns and A2 dentine shade tab was evaluated.
RESULTSThe L* and b* values of the abutments can be increased by all of the four groups of all-ceramic copings, but a* values were decreased in most groups. A statistical difference was observed among four groups. After being veneered, the L* values of all the copings declined slightly, and the values of a*, b* increased significantly. When compared with A2 dentine shade tab, the ΔE of the crowns was below 4.
CONCLUSIONFour ceramic copings were demonstrated to promote the lightness and hue of the alloy abutments effecttively. Though the colorimetric baseline of these copings was uneven, veneer porcelain can efficiently decrease the color difference between the samples and thee target.
Ceramics ; Chromium Alloys ; Cobalt ; Color ; Colorimetry ; Crowns ; Dental Materials ; Dental Porcelain ; Dental Prosthesis Design ; Humans ; Metal Ceramic Alloys ; Titanium ; Zirconium
5.Enantioselective determinination of R-warfarin/S-warfarin in human plasma using liquid chromatography-tandem mass spectrometry and its application in a drug-drug interaction study.
Shu JIN ; Yifan ZHANG ; Xiaoyan CHEN ; Ke LIU ; Dafang ZHONG
Acta Pharmaceutica Sinica 2012;47(1):105-9
To study the drug-drug interaction of morinidazole and warfarin and its application, a sensitive and rapid liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of R-warfarin/S-warfarin in human plasma. In a random, two-period crossover study, 12 healthy volunteers received a single oral dose of 5 mg racemic warfarin in the absence and presence of morinidazole. Blood samples were collected according to a pre-designed time schedule. R-warfarin, S-warfarin and methyclothiazide were extracted with ethylether : methylenechloride (3 : 2), then separated on a Astec Chirobiotic V (150 mm x 4.6 mm ID, 5 microm) column using 5 mmol x L(-1) ammonium acetate (pH 4.0) - acetonitrile as mobile phase at a flow-rate of 1.5 mL x min(-1). The mobile phase was splitted and 0.5 mL x min(-1) was introduced into MS. A tandem mass spectrometer equipped with electrospray ionization source was used as detector and operated in the negative ion mode. Quantification was performed using multiple reaction monitoring (MRM). The resolution of warfarin enantiomers is 1.56. The linear calibration curves for R-warfarin and S-warfarin both were obtained in the concentration range of 5 - 1 000 ng x mL(-1). Intra- and inter-day relative standard deviation (RSD) for R-warfarin and S-warfarin over the entire concentration range across three validation runs was both less than 10%, and relative error (RE) ranged from -4.9% to 0.7%, separately. The method herein described is effective and convenient, and suitable for the study of metabolic interaction between morinidazole and warfarin. The results showed that coadministration of warfarin with morinidazole did not affect the pharmacokinetics of either R-warfarin or S-warfarin.
6.Synthesis and characterization of lanthanum-incorporated hydroxyapatite coatings
Weiwei LOU ; Yiwen DONG ; Yifan JIN ; Jinsong LIU
Chinese Journal of Tissue Engineering Research 2014;(8):1224-1230
BACKGROUND:Hydroxyapatite-coated titanium substrates improve the biocompatibility and have the property of intimating ossteointegration with host bonebed. However, hydroxyapatite lacks the necessary mechanical strength and degrades easily in the extracelular fluids, which may affect the stability of the titanium implant.
OBJECTIVE:To study the synthesis and characterization of lanthanum-incorporated hydroxyapatite coatings.
METHODS: Lanthanum-incorporated hydroxyapatite coatings were prepared by hydroxyapatite and 10%, 20% and 30% lanthanum, respectively, by means of sol-gel, which were then deposited on titanium substrates with dip-withdrawal technique. Surface morphology and crystaline microstructure of the coatings were observed by scanning electron microscope. The presence of functional groups for the obtained samples was performed by Fourier transform infrared absorption spectroscopy and X-ray diffraction. The Ca2+ concentration released from the coatings was measured by atomic absorption spectrometry for analysis of degradation property.
RESULTS AND CONCLUSION: With the increase of lanthanum content, the diffraction peak and crystalinity of lanthanum-incorporated hydroxyapatite coatings were increased, but the whole structure of lanthanum-incorporated hydroxyapatites had little changes. The crystal structure maintained stable with charge balance. The lanthanum-incorporated hydroxyapatite coatings showed uniform and high-dense structure and were free of cracks, indicating the coatings had good bonding strength. Under the simulated biological environment, based on the determination of Ca2+ release from the coatings, we can conclude the lanthanum-incorporated hydroxyapatite coatings have a stronger acidoresistance.
7.Stress relaxation characteristics in brachial plexus of experimental animals using function as description method
Yaping Lü ; Yifan LIU ; Yunhe LI ; Peng LI
Chinese Journal of Tissue Engineering Research 2009;13(52):10321-10324
BACKGROUND:The brachial plexus injury anastomosis suture technique is necessary to understand the mechanics characteristic of brachial plexus nerve stress relaxation.Previous studies mainly focused on single tension mechanics of brechial plexus nerve,but few studies concerning stress relaxation and creeping elasticity.OBJECTIVE:To observe and analyze experimental animal brachial plexus nerve stress relaxation mechanics characteristic in the description manner of function,to provide experimental parameters for clinic.DESIGN,TIME AND SETTING:The experimental observations to use function as a way to describe from 1~(st) to 10~(th_ March,2007 at the Experimental Center of Jilin University.MATERIALS:The experimental male Sprague Dawley rats aged 6 months were provided by Changchun Gaoxin Medicine Animal Experimentation Center.METHODS:The stress relaxation experiment was performed in Experimental animal Brachial plexus Nerve on the the electronic universal testing machine (Shimadzu,Japan).The stress relaxation experiment strain increased speed was 1%/s,setting time of 7 200 seconds.100 empirical data were collected and disposed by one-way linear regression analysis.MAIN OUTCOME MEASURES:The stress relaxation data and curve,the Stress and time change rule were measured.RESULTS:The stress relaxation quantity of animal brachial plexus nerve test specimen at 7 200 s was 0.316 MPa.Stress relaxation curve changed with logarithm.Stress relaxation changed rapidly at 600 seconds,decreased gradually,and reached a balance level at 7 200 seconds.CONCLUSION:The stress relaxation curve changed with the logarithm relations.Brachial plexus has visco-elastic mechanical properties.
8.Study on the GC fingerprints of volatile oil in ultramicro-powder of Houttuynia cordata
Youlin HUANG ; Zhucan LIN ; Suhua GUO ; Jiancheng LIU ; Yifan HUANG
China Journal of Traditional Chinese Medicine and Pharmacy 2005;0(12):-
Objective:To establish a GC fingerprint analysis method for identification of volatile oil in ultramicro-powder of Houttuynia cordata from different habitats, then to control the quality sensitively.Methods: GC was used to analyze the volatile constituents of ultramicro-powder of Houttuynia cordata from 12 different habitats;SPDTM-1CapillaryColumn(30m?0.32mm?0.25?m),temperature programming and FID detector were applied.Results: The mutual mode of GC fingerprints was set up and the similar degrees to the volatile oil from of different habitats were compared.Conclusion:The GC fingerprints of volatile oil in ultramicro-powder can be used to identify the Houttuynia cordata from different habitats and evaluate its quality.
9.Shear mechanical properties of lumbar trabecular bone in aged people
Yaping Lü ; Yunhe LI ; Yifan LIU ; Hongshun MA
Chinese Journal of Tissue Engineering Research 2010;14(9):1595-1598
BACKGROUND:Shear mechanical properties of lumbar trabecular bone should be understood in treating osteoporosis,bone remodeling,bone reconstruction,as well as the choice of fracture fixed equipment.OBJECTIVE:To explore whether the shear mechanical properties of lumbar trabecular bone is different in young and aged normal fresh cadavers.METHODS:Experimental samples were from 4 normal fresh corpse,aged 22,28,70 and 75 years,were provided by Department of Anatomy,Norman Bethune Medical University.Spinal column thoracic vertebra L_2-L_5 specimen were obtained from corpse within 1 hour and cut into 40 min×5 mm×5 mm pieces.The specimen were tested on electronic universal testing machine with speed of 5 mm/min,the shear load,stress,strain and other data would be printed automatically,and the morphology of fracture surface was observed.RESULTS AND CONCLUSION:Majority of the fracture surfaces were comminuted,minority were transverse or oblique fracture.The macroscopic observation showed that trabecular arranged compact in the thoracic vertebra cancellous bone of the youth group,which was sparse arrangement and presented with senile osteoporosis in the aged group.The shear force,shear stress and strain of the youth group was greater than that of the aged group[(37.19±3.25),(28.34±3.42) N;(1.49+0.13),(1.13±0.14) MPa;(1.40±0.50)%,(0.90±0.20)%,P<0.05].It demonstrated that the impact mechanics properties of thoracic vertebra cancellous bone are different between the youth and aged groups.
10.Current situation and analysis of clinical application of auricular acupoint sticking therapy
Yanting YANG ; Qinfeng HUANG ; Yifan JIA ; Jie LIU ; Xiaopeng MA
Journal of Acupuncture and Tuina Science 2016;14(2):141-148
Objective: By the bibliometrical analysis and evaluation of acupuncture theses on auricular acupoint sticking from 2005 to 2014, the analysis was processed from multiple aspects including the types and numbers of diseases and effective rates of various diseases, in order to objectively reflect the general situation of clinical application of ear point embedding method in the recent years. Methods: By the bibliometrical analysis, the literature on auricular acupoint sticking in the recent ten years was counted up, analyzed and categorized. Results and Conclusion: Auricular acupoint sticking is used clinically for diseases of 16 systems, including 130 diseases. 74 diseases were singularly treated with auricular acupoint sticking, including the advantageous disease category like insomnia, constipation and obesity, and secondary advantageous disease category like dysmenorrhea, myopia, allergic rhinitis, post-operative pain and acne vulgaris.