1.Spectrophotometric Determination of Iodide with 〔I2Br〕--BasicTriarylmethane Dye System in Aqueous Solution
Chinese Journal of Analytical Chemistry 2001;29(3):323-326
The reaction conditions, the spectrophotometric characteristics, and the analytical properties of the ion-association complex of 〔I2Br〕- with the basic triarylmethane dye such as ethyl violet (EV), crystal violet (CV), and victoria blue 4R (VB4R) in the presence of polyvinyl alcohol (PVA) were studied. The results showed that the color of the solutions would change obviously when the above ion-association complexes were formed in dilute phosphoric acid solution. The molar absorptivities (ε) of different systems are between 2.6×104 and 6.2×104 L*mol-1*cm-1. The sensitivity of the ethyl violet system is the highest among them. Beer′s law is obeyed in the range of 0~1.6 mg/L I- for ethyl violet system, 0~1.4 mg/L for crystal violet system, and 0~0.8 mg/L I- for victoria blue 4R system, respectively. The method can be applied to direct determination of iodide in aqueous solution. The method has good selectivity. A large amounts of halide ions, some other inorganic acid group ions and amount of common metal ions don′t interfere the determination of I-. This method was used to determine I- in kelp, laver and soy bean with satisfactory results
2.Investigation of 64-slice computed tomography angiography in diagnosis of coronary artery disease
Mingyu LU ; Chuanfen LIU ; Jian LIU
Chinese Journal of Interventional Cardiology 1993;0(02):-
0.05).Conclusion 64-slice CT provided a high diagnostic accuracy in assessing coronary artery stenosis.
3.Efficacy of pedicle screw instrument for treatment of irreducible atlantoaxial dislocation
Mingyu ZHAI ; Chunping WANG ; Yuqiang LIU
Orthopedic Journal of China 2006;0(04):-
[Objective]To explore the surgical feasibility and clinical outcome of pedicle screw instrument for treatment of irreducible atlantoaxial dislocation and to choose an effective method of internal fixation.[Method]From June 2003 to February 2009,14 pationts with atlas dislocation followed by upper cervical cord compression were treated surgically with oral anterior soft tissue release combined with posterior reduction and pedicle screw instrument.Preoperative CT,MRI and radiographs as well as intraoperative screw placement and bone graft were administered in all pationts.Only cervical collars were used as external support for 3 months in occipitocervical fusion.[Result]All screws were successfully placed in atlas and axis.Forteen patients were followed up for an average of 18 months.Bone fusion was achieved in all cases with no complications of nerve,internal fixation failure and redislocation.Neurological recovery was significantly improved in 12 cases and took a turn for better in 2 cases.[Conclusion]Pedicle screw instrument in atlas and axis has the advantages of direct screw placement,short-segment fusion,intraoperative reduction and high fusion rate.It is a better alternative for atlantoaxial dislocation.
4.Stability of ferulic acid and its existing form in Ligusticum chuanxiong and Angelica sinensis
Mingyu DING ; Shuaiwu MA ; Deli LIU
Chinese Traditional and Herbal Drugs 1994;0(01):-
Object To investigate the isomer transition reaction of ferulic acid and the existing form of ferulic acid in Ligusticum chuanxiong Hort. and Angelica sinensis (Oliv.) Diels. Methods HPLC and HPLC-MS were used to confirm the isomer transition of ferulic acid. Results The trans-ferulic acid was translated into cis-ferulic acid partly when its solution was deposited under some routine conditions,and the trans- and cis-ferulic acids could coexist in the Chinese medicinal materials,L. chuanxiong and A. sinensis. Conclusion The trans-ferulic acid is stable thermodynamicly,but could be translated into cis-ferulic acid partly and slowly.
5.Streptococcus sanguis and Actinomycetes viscosus in oral biofilm foromation observed by sanning confocal laser microscopy
Mingyu LI ; Zheng LIU ; Cailian ZHU
Journal of Practical Stomatology 2000;0(05):-
砄bjective:To observe streptococcus sanguis (S.s) and Actinomycetes viscosus (A.v) in oral plaque biofilm formation.Methods:20 ml of saliva obtained from a health adult was centrifuged at 4 ℃ and 10 000 r/min for 10 min.The supernatant was disinfected in 60 ℃ water bath for 30 min.Glass coverslips in the size of 24 mm?24 mm were immersed into the saliva supernatant for 2 h to obtain biofilm.100 ?l of S.s ATCC 34 and A.v ATCC 19246 mixture cultured in TSB at the density of 10 5~6 CFU/ml was added into 20 ml of TSB,and then,the coverslips with biofilm were put into the mixture.The biofilm and bacteria were observed by scanning confocal laser microscopy at various times.Resuts:The biofilm reached the thickness of 15.4 ?m in 8 h and the clumps of the bacteria were mostly in the midle layer of the biofilm.The biofilm increased to 34.3 ?m in 16 h and became tassle like in 48 h.Conclusion: S.s and A.v may play some roles in the oral biofilm formation.
6.Establishment of an artificial biofilm mouth model for antimicrobial sensitivity tests
Mingyu LI ; Zheng LIU ; Cailian ZHU
Journal of Practical Stomatology 1995;0(04):-
Objective: To develop a new antimicrobial sensitivity test model for oral products in vitro. Methods: An artificial biofilm mouth model for antimicrobial sensitivity test was established by modified LKB chromatography chamber. Using sodium fluoride and tea polyphenol as antimicrobial agents and Streptococcus mutans as target, various methodologies on the sensitivity tests were compared. Results: Agar diffusion, agar dilution and broth macro-dilution were more sensitive than modeling biofilms method. The modeling biofilm assay resulted in MIC values of fluoride or tea polyphenol against S. mutans 32 and 12 times higher respectively than the MIC values generated by broth macro-dilution method. Conclusion :The biofilm artificial mouth model may simulate the environment for oral products test.
7.Three-dimension reconstruction of brain by Visualization Toolkit
Na WEI ; Yu WANG ; Mingyu LIU
Chinese Journal of Rehabilitation Theory and Practice 2005;11(3):167-169
ObjectiveTo implement two typical algorithms, Marching Cubes and Ray-casting, of medical image 3-D visualization using Visualization Toolkit (VTK) with VC++.MethodsSkull and scarfskin of brain were reconstructed based on CT data. Results and ConclusionVTK is a powerful tool with many advantages, such as easy to use, fast, good interaction ability, good results for image reconstruction and so on.
8.Relation between dissection structure of umbilical cord artery, blood flow indices and fetus′ growth
Heyi LIU ; Mingyu LIU ; Shuyan LIU ; Al ET
Chinese Journal of Ultrasonography 1997;0(06):-
Objective To study the relation between the dissection structure of umbilical cord artery and blood flow indices and fetus′ growth. Methods By color Doppler ultrasound, the diameter of umbilical cord and umbilical artery and umbilical vein was measured to compute surface area. The umbilical cord was divided into three parts: placenta affixing part, floating part and umbilical surrounding part.Their blood flow indices were measured and compared. Results Umbilical cord′s diameter in 21-40 weeks′ gestation was ( 1.25 ? 0.21 ) to ( 1.50 ? 0.18 )cm, surface area was ( 1.26 ? 0.13 ) to ( 1.83 ? 0.47 )cm 2.Umbilical artery′s diameter was ( 0.28 ? 0.06 ) to ( 0.40 ? 0.09 )cm, its surface area was ( 0.06 ? 0.03 ) to ( 0.14 ? 0.06 )cm 2.Umbilical vein′s diameter was ( 0.54 ? 0.11 ) to ( 0.79 ? 0.11 )cm, its surface area was ( 0.25 ? 0.02 ) to ( 0.49 ? 0.15 )cm 2. Before 25 weeks′ gestation, the blood flow indices of umbilical artey of placenta affixing part were lower than those of other two parts(P 0.05 ).Conclusions The diameter and surface area of umbilical and umbilical artery and umbilical vein were growing in pace with gestation, biparietal diameter,frontoccipital diameter, and heand circumference of the fetus,the blood flow indices of umbilical artery goes down continuously.The blood flow indices of umbilical artery of placenta affixing part reflect the fetus′ growth.
9.Evaluation of Antioxidant Activity of Flaxseed Extracts by 2, 2-Diphenyl-1-picrylhydrazyl-High Performance Liquid Chromatography Assay
Mingyu LIU ; Min LI ; Juanjuan CHEN ; Xian GUO ; Xiaojun YAN
Chinese Journal of Analytical Chemistry 2015;(2):245-250
The free radical scavenging effect of flaxseed was screened by HPLC-DPPH ( 2 , 2-diphenyl-1-picrylhydrazyl-high performance liquid chromatography assay ) and colorimetric DPPH methods. To test the effectiveness of the approach, three Lignans ( secoisolariciresinol diglucoside ( SDG ) , secoisolariciresinol ( SECO) and enterodiol( ED) ) with antioxidative properties were investigated both in monomer and mixture. HPLC conditions were optimized using following methods: Waters XBridge C18 was used as stationary phase, acetonil/H2 O was used as mobile phase and detective wavelength was set at 280 nm. Antioxidant activity of standards was investigated by reaction with or without DPPH radical for 20 min as sample and control, respectively. Both of them were analyzed by high performance liquid chromatography. According to the changes of amount of sample and control, the antioxidant activities of standards were calculated as following order:SDG>SECO>ED. Based on above DPPH-HPLC assay and UPLC-Q-TOF-MS, antioxidants extracted from flaxseed were separated, identified and screened. The radical scavenging activities were in the following order:SDG isomer (5)>SDG (4)>7α-[(β-D-glupyranosyl) oxy]-1-methoxyisolariciresinol (1)>(6R,7R, 8S)-1-methoxyisolariciresinol (2)>herbacetindiglucoside (3). It indicated that the HPLC-DPPH assay could be successfully used for the antioxidant activity screening of complex flaxseed extract.
10.Application value of dynamic changes of serum smooth muscle myosin heavy chain level in diagnosis and prognosis of aortic dissection
Wenzhong CHEN ; Mingyu QIU ; Yanxian LAI ; Jindong ZHOU ; Kai LIU
Chinese Journal of Postgraduates of Medicine 2014;37(25):37-40
Objective To observe the change of serum smooth muscle myosin heavy chain (smMHC) level in the patients with aortic dissection (AD),and evaluate the effect of smMHC in the early diagnosis and prognosis of AD.Methods Forty-two patients with AD were selected as AD group,30 healthy subjects were selected as control group.Blood samples were collected at four time periods (within 3 h of onset,6 h,12 h,24 h),and serum smMHC level were measured by enzyme-linked immunosorbent assay.Results Serum smMHC level of AD group,which collected (within 3 h of onset,6 h,12 h) were significantly higher than that of control group [(88.6 ±21.7),(59.4 ± 18.7),(41.3 ± 10.7) ng/L vs.(17.2 ± 8.3) ng/L,P < 0.01].There was no significant difference between the serum smMHC level of AD group and control group at 24 h after onset [(18.9 ±9.5) ng/L vs.(17.2 ±8.3) ng/L,P > 0.05].Serum smMHC level of Stanford A type group (25 cases) was higher than that of Stanford B type group (17 cases) within 3 h of onset [(95.4 ± 17.8) ng/L vs.(78.5 ± 18.3) ng/L,P<0.01],and there was no significant difference bewteen the two groups which collected at 6,12 h and 24 h after onset (P > 0.05).Preoperative serum smMHC level was significantly higher than that after intracavitary isolation operation [(58.6 ± 15.9) ng/L vs.(30.1 ± 12.5) ng/L,P < 0.01].Serum smMHC level decreased rapidly after the operation,and there was no significant difference between the two grougs when 12 h after operation [(18.7 ± 8.9) ng/L vs.(17.2 ± 8.3) ng/L,P > 0.05].The serum smMHC level of the deaths (7 cases),which collected within 3 h of onset,6 h,12 h,was significantly higher than that of the survivors (35 cases) [(101.2 ± 20.7) ng/L vs.(86.1 ± 18.9) ng/L,(65.2 ± 16.7) ng/L vs.(58.2 ± 14.2) ng/L,(50.4 ± 10.8) ng/L vs.(39.5 ± 8.3) ng/L,P < 0.05],and there was no significant difference at 24 h after onset (P > 0.05).Detecting serum smMHC level within 3 h of onset,the area under the receiver operating characteristic curve was 0.913,with 51.7 ng/L as a diagnostic critical value,sensitivity and specificity respectively was 88.1% (37/42) and 96.7% (29/30).When detecting at 6 h after onset,the area under the curve was 0.865,with 38.5 ng/L as a diagnostic critical value,sensitivity and specificity respectively was 90.4%(38/42) and 90.0% (27/30).Conclusions The level of serum smMHC in patients with AD increase rapidly after onset,and detecting serum smMHC level within 6 h of onset have important clinical significance in early diagnosis and prognosis of AD.