1.Time-frequency analysis of ECG signals
Zhen LEI ; Yiping CHEN ; Yan TANG
Chinese Medical Equipment Journal 2004;0(08):-
In this paper,a time-frequency approach is used for the recognition and analysis of ECG signals for a normal or an abnormal patient.An iterative deconvolution procedure is applied to calculate the time-frequency representations.This method can enhance the resolutions of the signals.
2.Effects of recombinant human relaxin-2 on hepatic stellate cell proliferation, synthesis of Collagen Ⅰ,and mRNA expressions of TGF-β1 and CTGF in vitro
Zhen CHEN ; Junwang XU ; Su YAN ; Ke CHEN ; Xiude FAN
Journal of Xi'an Jiaotong University(Medical Sciences) 2017;38(1):44-47,57
ABSTRACT:Objective To validate that relaxin can resist hepatic fibrosis at the cellular level and explore its molecular mechanism in order to provide experimental basis for the treatment of liver cirrhosis.Methods Cultured HSC-T6s were treated with different concentrations (20,50 and 100 ng/mL)of recombinant human relaxin-2 (RLX-2).The proliferation of HSC-T6 was measured by MTT colorimetric assay.The content of type Ⅰcollagen in the cell culture supernatant of each group was detected by ELISA at 48 h of drug intervention;RT-PCR was used to detect the mRNA expressions of CTGF and TGF-β1 in HSC-T6 at 48 h of drug intervention.Results RLX-2 inhibited the proliferation of HSC and reduced type Ⅰ collagen content of HSC cells.It also inhibited the CTGF mRNA expression of HSC,but did not have a significant effect on the expression of TGF-β1 mRNA. Conclusion In the experiment of culturing HSC-T6 in vitro,RLX-2 may play a role in rat liver fibrosis by inhibiting cell proliferation and type Ⅰ collagen and CTGF mRNA expressions.
3.Automatically feeding strategy for 1,3-propanediol fermentation of Klebsiella pneumoniae LDH526.
Jinhai HUANG ; Zhen CHEN ; Yan SUN ; Dehua LIU
Chinese Journal of Biotechnology 2015;31(10):1520-1527
1,3-propanediol is an important chemical used as building block for the synthesis of highly promising polyesters such as polytrimethylene terephthalate. A genetically modified Klebsiella pneumoniae LDH526 can use glycerol as sole carbon source and produce 1,3-propanediol with the titer above 90 g/L. A key factor affecting the production of 1,3-propanediol by the mutant K. pneumoniae is the accurate control of the feeding of glycerol. To generate a robust and reproducible fermentation process of 1,3-propanediol, we designed and optimized an automatically feeding strategy of glycerol based on fermentation kinetics. By coupling the substrate feeding rate with easily observed variables -pH and fermentation time, we have achieved self-starting glycerol feeding and dynamic control of the glycerol concentration during the fermentation process. This automated system allowed us to generate a reproducible, consistent and operator-independent process from lab-scale to production scale. The final concentration of 1,3-propanediol was above 95 g/L after 72 h.
Culture Media
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Fermentation
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Glycerol
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Industrial Microbiology
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methods
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Klebsiella pneumoniae
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growth & development
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Propylene Glycol
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Propylene Glycols
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metabolism
4.Comparison of radiobiological models for evaluation of radiotherapy treatment planning of breast cancer
Weibing ZHOU ; Yan FENG ; Jiayi CHEN ; Zhen ZHANG
Chinese Journal of Radiation Oncology 2008;17(4):293-297
Objective To find an appropriate r3diobiological model for analyzing the biological effect of the radiotherapy for breast cancer by comparing different results computed by various types of radiobiological models. Methods DVHs database simulating breast conserving radiotherapy was set up,based on clinical DVHs data of the heart.the lung and PTV of 22 patients with early breast cancer given conventional tangential radiotherapy.Two models assessing NTCP of radiation pneumonitis and cardiac mortality and four models assessing TCP were compared by analyzing the effects of the parameters and DVH database input methods on the results. Results When mean irradiation dose of the whole lung was 30 Gy.the incidence of radiation pneumonitis was 32%and 54%predicted by NTCP-RSM model and NTCP-Lyman model,respectively.When 1%cardiac mortality of radiation was assumed,28 Gy and 40 Gy isodose should cover the heart assessed by the two models.The mean TCP were 21.1%.80.8%.38.4%and 41.0%when assessed by LQ-Poisson-TCP,Zaider-TCP,Poisson-TCP and Logit-TCP models,respectively.Setting various differential DVH(dDVH)bins had very few effect on the NTCP/TCP results in a certain model.Adopting physical dose or LQED2 affected the results with greater resu]ts for physical dose.Variation in α or β value,tumor cell density and D50 had significant effect upon TCP results in LQ-Poisson-TCP(P:0.000). Conclusions NTCP-Lyman model is better for predicting the incidence of radiation pneumonitis while NTCP-RSM model is better for predicting radiation-induced cardiac mortality.LQ-Poisson-TCP is the best TCP model for clinical application.Parameters selected for model can significantly affect the results.It is imporrant to understand the distinct characteristics of different models.
5.Fermentation research of new type recombinant human tumor necrosis factor alpha
Zhen YAN ; Yingqi ZHANG ; Min LI ; Changqing CHEN
Chinese Journal of Biochemical Pharmaceutics 2001;22(2):64-67
Purpose The aim is to establish fermentation process of new type recombinant human necrosis factor (nrhTNF)α.Methods The optimized host cell,culture medium and induction time were deternined according to the growth and expression specificity of nrhTNF on test tube and flask shaker. Then fed-batch culture was carried out on 5 L automatic fermentor.Results The expression of nrhTNF in fermentor could keep in a higher level of about 50% of total bacterial proteins when fermented to around A600nm 30,with a fermentation time of 12 h to 13 h.Conclusion A short cycle,high expression and stabilized fermentation process was established.
6.Malignant granular cell tumor of the urinary bladder.
Yan-zhen ZHUANG ; Xian-yi JIANG ; Pei-qiong CHEN
Chinese Journal of Pathology 2006;35(3):188-188
Cystectomy
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Fatal Outcome
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Female
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Glial Fibrillary Acidic Protein
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metabolism
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Granular Cell Tumor
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pathology
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secondary
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surgery
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Humans
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Immunohistochemistry
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Middle Aged
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S100 Proteins
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metabolism
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Urinary Bladder
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chemistry
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pathology
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surgery
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Urinary Bladder Neoplasms
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metabolism
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pathology
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surgery
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Vaginal Neoplasms
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metabolism
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secondary
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surgery
7.Clinical analysis of pin-shaped bipolar plasmakinetic electrode used in transurethral en bloc resection of non muscle-invasive bladder urothelial carcinoma
Wei YAN ; Ludong QIAO ; Zhen DU ; Shan CHEN
Chinese Journal of Urology 2016;37(9):672-676
Objective To introduce the surgery procedure of pin-shaped bipolar plasmakinetic transurethral en bloc resection of non muscle-invasive bladder urothelial carcinoma and investigate the clinical outcomes.Methods 42 cases of non muscle-invasive bladder urothelial carcinoma who received bipolar plasmakinetic transurethral en bloc resection from May 2015 to March 2016 were recruited in the present study.Male 29 cases, female 13 cases, average age 52-82 years old, average (65.6 ±12.3) years old.Wide basal tumors were noticed by preoperative cystoscopy, bladder tumors were confirmed by tumor biopsy.Full-thickness specimens were obtained in procedures, including tumor, mucosa, lamina propria layer, muscular layer, to accurately assess tumor infiltration depth and staging.Results All 42 cases were done by this procedure successfully.A total of 65 pieces of tumors were excised:36 in lateral wall, 19 in posterior wall, 10 in bladder triangle.Tumor diameter ranged from 0.5 to 3.5 cm, with an average (2.1 ± 0.6) cm.Postoperative pathological stages were clear:16 cases were Ta stage and 49 cases were T1 stage ( of which 32 were T1 G3 ) .Intraoperative obturator nerve reflex happened in 2 cases.Followed up for 2-11 months, average 6 months.Tumor recurrence in 3 cases, no progression case.Conclusions Pin-shaped bipolar plasmakinetic electrode transurethral en bloc resection of non muscle-invasive bladder urothelial carcinoma is safe and reliable and should be recommended in management of non muscle-invasive bladder urothelial carcinoma.Full-thickness postoperative specimens can provide accurately judgement of the depth of tumor invasion and pathological staging.
8.New studies on adjunctive therapies for osteomyelitis
Zhen WANG ; Yan ZHANG ; Yancheng ZHU ; Xusheng QIU ; Yixin CHEN
Chinese Journal of Orthopaedic Trauma 2016;18(12):1064-1068
Osteomyelitis,particularly chronic one,is still a huge challenge to orthopedic surgeons.The current treatment for osteomyelitis centers on sensitive antibiotic coverage and surgical debridement of nonviable tissue.However,treatment failure and recurrence are common.Recently,adjunctive therapies such as hyperbaric oxygenation have been widely applied in treatment of osteomyelitis to promote sanative effect on osteomyelitis.In this review,we will outline the rationales and current status of potential adjunctive therapies in osteomyelitis management.
9.Research progress on enlargement of medicinal resources of Paridis Rhizome.
Li CHENG ; Yan ZHEN ; Min CHEN ; Lu-qi HUANG
China Journal of Chinese Materia Medica 2015;40(16):3121-3124
Currently, as an important raw material of Chinese traditional patent medicines, Paridis Rhizome is in great demand, which led to its price increases. In order to protect the wild resources and satisfy market demand of Paridis rhizome, the researches in various directions were conducted, involved its chemical composition, pharmacological action, clinical application, resource investigation, artificial cultivation, etc. Herein, the chemical studies of genus Paridis Rhizome, aerial parts of Paridis Rhizome gummy and starchy Paridis Rhizome, and the studies of endophyte in Paridis Rhizome were reviewed and analyzed in order to explore the substitutes of Paridis Rhizome, and provide the reference for the enlargement of medicinal resources of Paridis Rhizome. It manifests that the steroidal saponins, the important chemical compositions in Paridis Rhizome were tested in genus Paridis Rhizome, aerial parts of Paridis Rhizome, gummy Paridis Rhizome and the endophyte in Paridis Rhizome. However, the further experimental studies and clinical verification works should be carried out to confirm the final substitute.
Animals
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Drug Therapy
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Drugs, Chinese Herbal
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chemistry
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pharmacology
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Humans
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Liliaceae
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chemistry
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growth & development
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Rhizome
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chemistry
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growth & development
10.Research concerning the effect of analgesics on fracture healing
Zhen WANG ; Yan ZHANG ; Yancheng ZHU ; Xusheng QIU ; Yixin CHEN
Chinese Journal of Orthopaedic Trauma 2017;19(5):457-460
Analgesics are widely used in fracture patients before and after operation.The analgesics frequently used include non-steroidal anti-inflammatory drugs,as well as central nerve and local medications.Recently,researches report that some analgesics may inhibit fracture healing,which has attracted much attention from orthopedic surgeons.However,there are researchers who hold opposite opinions.Accordingly,this paper reviews the progress in research concerning the effect of analgesics on fracture healing.