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find Keyword "phase" 39 results
  • THE EXPERIMENTAL STUDY OF CULTURE OF PERIOSTEAL OSTEOBLAST ON BIOACTIVE MATERIALS

    Abstract A new type of artificial material could possibly be produced by combination of osteoblast with bioactive material in culture, and thus, make the material "alive" . To study the behavior of osteoblast cultured with bioactive materials, the osteoblasts were isolated from the periosteum of Newzeland Rabbits tibia, and cultured in RPMI1640 medium. After 13 subcultures, the cells were identified as osteoblast in vitro by electron microscope, AKP activity and detection of mineral deposition ability. The osteoblasts were subcultured with three bioactive materials: bioactive glass ceramics (BGC), hydroxyapatite (HA), and double phase hydroxyapatite (HA/TCP). After incubationfor 48 hours, scan electron microscope, 3H-TDR, XRD, RS and EDXAwere performed. The results showed that the osteoblasts grew on the HA/TCR had a higher proliferation rate and better osteoblastoid shape than those grew on BCG and HA. Themechanism of the growth of osteoblasts on bioactive materials was discussed, and the factors influencing the growth of osteoblast were analyzed.

    Release date:2016-09-01 11:11 Export PDF Favorites Scan
  • Preparation and osteogenic properties of poly (L-lactic acid)/lecithin porous scaffolds with open pore structure

    ObjectiveTo investigate the preparation and osteogenic properties of poly (L-lactic acid)(PLLA)/lecithin porous scaffolds with open pore structure.MethodsPLLA/lecithin porous scaffolds with different lecithin contents (0, 5%, 10%, 20%, 30%, 40%, 50%) were prepared by thermally induced phase separation (groups A, B, C, D, E, F, and G, respectively). Scanning electron microscopy (SEM) was used to observe the surface morphology of the scaffolds. Wide-angle X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to detect the crystallinity of the scaffolds. The water uptake ability of the scaffolds was measured. The cell growth and viability of bone marrow mesenchymal stem cells (BMSCs) of mouse on each scaffold was assessed by cell counting kit 8 (CCK-8) method. The osteogenic differentiation ability of BMSCs on each scaffold was evaluated by alkaline phosphatase (ALP) activity. Finally, a critical-size rat calvarial bone defect model was used to evaluate the osteogenesis of the scaffolds in vivo. Micro-CT was used to reconstruct the three-dimensional model of the defect area, and the bone volume and bone mineral density were quantitatively analyzed.ResultsSEM results showed that the lecithin could slightly reduce the pore size; when lecithin content was 50%, platelet-like structure could be observed on the scaffolds. Wide angle XRD and DSC showed that the crystallinity of scaffolds gradually decreased with the increase of lecithin content. The water uptake ability test showed that the hydrophilicity of scaffolds increased with the increase of lecithin content. CCK-8 assay showed that cell activity gradually increased with the increase of culture time. After 7 days of culture, the absorbance (A) value of groups C, D, E, and F were significantly higher than that of groups A, B, and G (P<0.05), but no significant difference was found among groups C, D, E, and F (P>0.05). After 14 days of osteogenic induction, with the increase of lecithin content, there was a significant difference in ALP activity of each group. The ALP activity in groups D, E, F, and G were significantly higher than that in groups A, B, and C (P<0.05).In vivo, the results of Micro-CT examination and bone volume and bone mineral density showed that the scaffolds with 30% lecithin had the best repairing effect.ConclusionPrepared by thermally induced phase separation, the cytocompatibility, osteogenic differentiation, and bone repair ability of the PLLA/lecithin porous scaffold is obviously better than that of pure PLLA scaffold. PLLA/lecithin porous scaffold with suitable lecithin content is a promising scaffold material for bone tissue engineering.

    Release date:2018-09-03 10:13 Export PDF Favorites Scan
  • Research on mental fatigue information transmission integration mechanism based on theta-gamma phase amplitude coupling

    Mental fatigue is a subjective fatigue state caused by long-term brain activity, which is the core of health problems among brainworkers. However, its influence on the process of brain information transmission integration is not clear. In this paper, phase amplitude coupling (PAC) between theta and gamma rhythm was used to study the electroencephalogram (EEG) data recorded before and after mental fatigue, so as to explain the effect of mental fatigue on brain information transmission mechanism. The experiment used a 4-hour professional English reading to induce brain fatigue. EEG signals of 14 male undergraduate volunteers before and after mental fatigue were recorded by Neuroscan EEG system. Phase amplitude coupling value was calculated and analyzed. t test was used to compare the results between two states. The results showed that theta phase of more than 90% of the electrodes in the whole brain area jointly modulated gamma amplitude of the right central area and the right parietal area, and the coupling effect among different brain regions significantly decreased (P < 0.05) when participants had felt mental fatigue. This paper shows that phase amplitude coupling can explain the influence of mental fatigue on information transmission mechanism. It could be an important indicator for mental fatigue detection. On the other hand, the results also provide a new measure to evaluate the effect of neuromodulation in relieving mental fatigue.

    Release date:2018-10-19 03:21 Export PDF Favorites Scan
  • Clinical Analysis on Perioperative Death of Endovascular Repair for Acute Aortic Dissection

    Objective To analyze the reasons for the perioperative death of endovascular repair of acute aortic dissection (AD). Methods The clinical data of 176 patients with acute AD and received endovascular repair from July 2001 to October 2012 were analyzed retrospectively. Results Among 176 patients with acute AD, 8 patients died during perioperatively, received endovascular repair in 1-5 days after admission (mean 2.4 d), and all of them admitted before 2008. Two cases were type A and 6 cases were type B. All cases with hypertension and 3 cases with pleural effusion. Three cases died on the day of operation, among them 2 cases occurred in 1 h after operation, the other 1 case occurred in 2 h after operation. Four cases died in 2 days after operation and 1 case died in 4 days after operation. Four cases died of rupture of the aortic dissection, 2 cases died of cerebral infarction, 1 case died of multiple organ failure, and 1 case died of gastrointestinal bleeding. Conclusion To avoid performing endovascular repair during the acute phase and improving operation skills may help to avoid the occurrence of perioperative death.

    Release date:2016-09-08 10:24 Export PDF Favorites Scan
  • Analysis of Technical Keypoints of The Second-Phase Diaplasis Treatment after Hartmann Operation

    Objective To discuss the technical keypoints of the second-phase diaplasis treatment after Hartmann operation. Methods Twenty-one cases of the second-phase diaplasis operation of Hartmann operation in this hospital from January 2003 to December 2007 were analysed retrospectively. Results In this group, stapler technique was used in 15 cases, anastomotic ring was used in 3 cases, and one-layer suture was used in 3 cases. The time of these operations was between 118 min and 240 min (mean 164 min). Neither stomal leak nor stomal stenosis occurred, acute ileus occurred in 2 cases, and both recovered after the treatments of gastrointestinal decompression, inhibition of secretion digestive juice and reoperation. Acute retension of urine occurred in 1 case after urine catheter removed. The symptoms disappeared after excises of bladder function. These cases were followed up for 3-36 months (mean 20 months). All the patients recovered to normal function of defecation. Conclusion The technical keypoints of the second-phase diaplasis treatment after Hartmann operation are how to find and liberate the end of the distal colon. It will affect the prognosis and the occurrence of complications after this operation.

    Release date:2016-09-08 11:07 Export PDF Favorites Scan
  • Interpretation of the statistical analysis plan (SAP) extended reporting guidelines and their enlightenment for the design of early stage clinical studies of new drugs

    The utilisation of statistical analysis plan (SAP) has the potential to enhance the reliability, transparency, and impartiality of statistical analysis procedures in the context of clinical studies. These plans are primarily designed for late phase clinical studies, namely phase Ⅱ and phase Ⅲ randomised controlled trials. The extended SAP reporting guidelines for early phase clinical studies, i.e., phase Ⅰ clinical studies and phase Ⅱ non-randomised controlled trials, have been expanded from the original reporting guidelines in six key areas: trial purpose, design, Bayesian statistics, data simulation, sample size, and the application of ICH E9 (R1). The expanded reporting guidelines facilitate the standardisation of SAP for early phase clinical trials, enhance the transparency and reproducibility of early phase clinical studies, and thereby improve the quality of early phase clinical studies. This, in turn, plays a pivotal role in later phase clinical studies.

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  • Evidence-Based Treatment of a Patient with Chronic-Phase Chronic Myeloid Leukemia by Imatinib

    Objective We intended to get good understanding of the current role of imatinib (or glivec) in the treatment of a patient with chronic-phase chronic myeloid leukemia. Methods We attempted to find the current best evidence of imatinib for treating chronic myeloid leukemia in chronic phase by searching ACP Journal Club (1991 -Jun, 2005 ), The Cochrane Library(Issue 2, 2005 )and MEDLINE(1990 -Jun, 2005 ) and further critically appraised the available evidence. Results Imatinib appeared to be more effective than current standard drag treatments in terms of hematologic and cytogenetic response with better quality of life and fewer side effects. However, there was uncertainty concerning long term outcomes. Given the current evidence together with our clinical experience and considering the patient and his family members' values and preference, imatinib (400 mg qd) was administered to him. No obvious adverse effects occurred with 3 months follow-up. Conclusions Imatinib is effective and well tolerated in the treatment of chronic myeloid leukemia in chronic phase. Further researches on long-term follow-up data from imatinib trials are definitely needed.

    Release date:2016-09-07 02:25 Export PDF Favorites Scan
  • A design of raster plot for illustrating dynamic neuronal activity during deep brain stimulation

    Deep brain stimulation (DBS), which usually utilizes high frequency stimulation (HFS) of electrical pulses, is effective for treating many brain disorders in clinic. Studying the dynamic response of downstream neurons to HFS and its time relationship with stimulus pulses can reveal important mechanisms of DBS and advance the development of new stimulation modes (e.g., closed-loop DBS). To exhibit the dynamic neuronal firing and its relationship with stimuli, we designed a two-dimensional raster plot to visualize neuronal activity during HFS (especially in the initial stage of HFS). Additionally, the influence of plot resolution on the visualization effect was investigated. The method was then validated by investigating the neuronal responses to the axonal HFS in the hippocampal CA1 region of rats. Results show that the new design of raster plot is able to illustrate the dynamics of indexes (such as phase-locked relationship and latency) of single unit activity (i.e., spikes) during periodic pulse stimulations. Furthermore, the plots can intuitively show changes of neuronal firing from the baseline before stimulation to the onset dynamics during stimulation, as well as other information including the silent period of spikes immediately following the end of HFS. In addition, by adjusting resolution, the raster plot can be adapted to a large range of firing rates for clear illustration of neuronal activity. The new raster plot can illustrate more information with a clearer image than a regular raster plot, and thereby provides a useful tool for studying neuronal behaviors during high-frequency stimulations in brain.

    Release date:2019-04-15 05:31 Export PDF Favorites Scan
  • Cross-sectional Study on the Relationship between Syndromes of Traditional Chinese Medicine and Lung Function in Patients with Chronic Obstructive Pulmonary Disease at Stable Phase

    Objective?To investigate the relationship between syndromes of traditional Chinese medicine (TCM) and lung function in patients with chronic obstructive pulmonary disease (COPD) at stable phase. MethodsBased on diagnostic criterion of TCM, five groups of symptoms of TCM about stable COPD were established including lung Qi deficiency, lung and spleen Qi deficiency, lung and kidney Qi deficiency, lung Spleen Kidney Qi deficiency, and deficiency of both Qi and Yin. A total of 300 cases which were up to the standard were differentiated into 5 groups by the symptoms. Some basic details and lung function of the patients were recorded, and then statistical analysis was performed to analyze the differences of lung function among groups. ResultsForced expiratory volume in the first second in descending order was lung Qi deficiency group, lung and spleen Qi deficiency group, lung and kidney Qi deficiency group, and lung spleen kidney Qi deficiency group (P<0.05). ConclusionThese findings suggest that with the progressing of COPD, the symptom type of TCM for COPD patients at stable phase may vary from lung Qi deficiency to lung and spleen Qi deficiency, or to lung and kidney Qi deficiency, and even lung, spleen and kidney Qi deficiency. Lung function tests help reveal substance and pathogenesis of TCM syndromes of patients with stable COPD, and provide evidence for the clinical syndrome.

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  • 99Tcm-MIBI SPECT Dual-Phase Imaging, B-Ultrasound, and CT in The Diagnostic Value of Primary Hyperparathyroidism

    ObjectiveTo investigate the significance of 99Tcm-MIBI SPECT dual-phase imaging, B-ultrasound and CT in the diagnosis of primary hyperparathyroidism, and its relationship with the level of serum calcium (CA). MethodsThe clinical data of 73 patients with parathyroid dysfunction (serum parathyroid hormone (PTH) > 130 pg/mL) were retrospectively analyzed. The 99Tcm-MIBI SPECT double phase imaging were performed in 73 cases, 63 cases underwent cervical B-ultrasound examination, and 16 cases underwent CT examination. According to the serum calcium (CA) levels, the patients were divided into CA < 2.7 mmol/L group and CA > 2.7 mmol/L group, and the postoperative pathological examination and followed-up results were as the standard, the sensitivity, specificity, positive predictive value, and negative predictive value of 99Tcm-MIBI SPECT dual-phase imaging, B-ultrasound and CT for diagnosis of PHPT in different serum CA levels were compared. ResultsThe sensitivity of 99Tcm-MIBI SPECT dual-phase imaging, B-ultrasound and CT examination for diagnosis of PHPT was 87.6%, 81.8% and 35.7%, respectively; the specificity was 87.5%, 75.5% and 50.0%, respectively; the positive predictive value was 98.2%, 93.7% and 83.3%, respectively; and the negative predictive value was 46.7%, 33.3% and 10%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of 99Tcm-MIBI SPECT dual-phase imaging and B-ultrasound examination for diagnosis of PHPT were significantly higher than those of CT examination(P < 0.05). The sensitivity, specificity, positive predictive value and negative predictive value of 99Tcm-MIBI SPECT dual-phase imaging for diagnosis of PHPT were higher than those of B-ultrasound examination, but the difference was not statistically significant (P > 0.05). In the CA < 2.7 mmol/L group, the sensitivity of 99Tcm-MIBI SPECT dual-phase imaging, B-ultrasound and CT examination for diagnosis of PHPT was 91.1%, 84.7% and 37.9%, respectively; the specificity was 80.2%, 72.9% and 49.7%, respectively; the positive predictive value was 96.8%, 96.0% and 79.4%, respectively; and the negative predictive value was 50.0%, 37.5% and 10.0%. In the CA > 2.7 mmol/L group, The sensitivity of 99Tcm-MIBI SPECT dual-phase imaging, B-ultrasound and CT examination for diagnosis of PHPT was 87.9%, 83.9% and 42.8%, respectively; the specificity was 83.3%, 79.2% and 50.0%, respectively; the positive predictive value was 96.9%, 94.1% and 75.0%, respectively; and the negative predictive value was 50.0%, 40.5% and 20.0%. There were no significant difference in the diagnostic accuracy between the 3 methods and the level of serum CV in different levels. ConclusionsThe diagnostic accuracy of 99Tcm-MIBI SPECT dual-phase imaging and B-ultrasound examination for diagnosis of PHPT patients with PTH > 130 pg/mL (especially parathyroid adenoma) were higher than that of CT examination, and it is not associated with the serum CA concentration.

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