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find Keyword "分布" 69 results
  • Time Distribution in the Occurrence of Acute Aortic Dissection

    【摘要】 目的 研究急性主动脉夹层时间分布规律。 方法 回顾性研究我院2000年1月-2010年12月所有急性主动脉夹层患者的时间资料,分析其月份、季节、周以及时刻分布特点。 结果 急性主动脉夹层月份分布高峰点为1月4日,高峰段为9月21日~次年4月19日(Plt;0.05);季节分布以冬春季较多(Plt;0.05);周分布无高峰点及高峰段(Pgt;0.05);时刻分布高峰点为上午10点及下午4点。 结论 急性主动脉夹层具有明显的时间分布规律,我们应该在该病的高峰时间更加重视其发生的可能,从而减少误诊,改善预后。【Abstract】 Objective To investigate the features of time distribution in the occurrence of acute aortic dissection (AAD).  Methods We retrospectively analyzed all the databases of AAD in our hospital between January 1, 2000 and December 31, 2010, and studied the monthly, seasonal, weekly, and circadian distribution of the cases. Results In terms of monthly distribution, the occurrence of AAD peaked at January 4th with the high frequency in the period of September 21st to April 19th of the next year (Plt;0.05). According to the seasonal distribution, the occurrence of AAD peaked in winter and spring (Plt;0.05). There was no peak time in weekly distribution (Pgt;0.05). In accordance with circadian distribution, the occurrence of AAD peaked at 10 and 16 o’clock (Plt;0.05). Conclusion Because of the obvious rhythm of time distribution of AAD, We can pay more attention to the diagnosis of AAD especially in the peak time, thus reducing the mistakes in diagnosis and improving the prognosis.

    Release date:2016-09-08 09:25 Export PDF Favorites Scan
  • ANALYSIS OF hBMSCs SPATIAL DISTRIBUTION AND GENE EXPRESSION IN BIOCORAL SCAFFOLD WITH DIFFERENT SEEDING METHODS

    Objective To compare the effect of two different methods of cell seeding on spatial distribution and gene expression of hBMSCs in biocoral scaffold in vitro cultures. Methods The composite of hBMSCs and biocoral scaffold was prepared by traditional seeding (group A) and fibrin glue seeding (group B). The seeding efficiency was measured after 30 minutes of incubation in group B and after 3 hours in group A. At 2, 7, 14 and 21 days after culture, the samples were harvestedand the serial longitudinal sections were cut for each embedded composite. The sections were stained with DAPI and were measured using fluorescence microscope with apotome under serial optical sections. The cell number in every 10 × objective field was automatically measured by AxioVision image analysis software and levels (from seeding surface to bottom L1-L5) or columns (from centre to margin) for comparing cell distribution were set up. The specific osteogenic genes [osteonectin (ON), core binding factor α1 (Cbfα1), osteocalcin (OC)] expression was measured by RT-PCR. Results The seeding efficiency was significantly higher in group B (88.32% ± 4.2%) than in group A (66.51% ± 12.33%, P lt; 0.01). At 2 days after culture, the cell number from L1 to L4 decreased gradully in two groups (P lt; 0.05); in the cell number of different columns, there was no significant difference in group A (Pgt; 0.05) whereas significant difference in group B (P lt; 0.05); there was no significant difference in gene expression between two groups (P gt; 0.05). At 7 days after culture, the cell number was less than that at 2 days in group A and there was significant difference among levels (P lt; 0.05). The cell number and osteogenic gene expression increased sharply and there appeared uniform cell distribution in group B (P gt; 0.05). The gene expression of ON and Cbfα1 in group B was higher than that in group A (Plt; 0.05). At 14 days after culture, the cell number in levels or columns in group A decreased sharply and was less than that at 7 days (P lt; 0.05); whereas the cell number was similar to that at 7 days in group B (P gt; 0.05). The OC gene expression reached the highest level in group B at 14 days. The gene expression was higher in group B than in group A (P lt; 0.05). At 21 days after culture, there was significant difference in the cell number among levels and in the gene expression between group A and group B (P lt; 0.05); there was no significant difference in the cell number among columns in two groups (Pgt; 0.05). In addition, the cell number of most levels and columns in group B was more than that in group A at 7, 14 and 21 days after culture (P lt; 0.05). Conclusion More uniform cell distribution with rapid prol iferation and osteogenic differentiation is available in different levels or columns of scaffold by fibrin glue seeding than by traditional seeding.

    Release date:2016-09-01 09:07 Export PDF Favorites Scan
  • Associations of preoperative red cell distribution width with mortality and morbidity in patients underwent liver transplantation: a retrospectively observational study

    ObjectiveTo investigate the associations of preoperative red cell distribution width (RDW) with mortality and morbidity in patients underwent liver transplantation. MethodsThis investigation was a retrospective study, the patients underwent liver transplantation met the inclusion criteria from June 2017 to May 2020 in the West China Hospital of Sichuan University were enrolled. The patients were divided into RDW≤14.5% group and RDW>14.5% group according to the normal RDW critical value (14.5%). The propensity score matching (PSM) was used to adjust the baseline characteristics. The primary outcome was 1-year mortality. The secondary outcomes included 1-year survival, 30-day mortality, incidence of early allograft dysfunction, acute kidney injury, renal replacement therapy, and pulmonary complications, as well as ICU stay and postoperative hospital stay. ResultsA total of 303 patients who met the analysis conditions were included. After PSM, 57 patients in each group were matched. There were no significant differences between the two groups in the baseline data such as the gender, age, body mass index (BMI), initial diagnosis, MELD score, Child-Pugh grade of the recipients, and the gender, age, and BMI of the donors (P>0.05). The 1-year [22.8% (13/57) versus 5.3% (3/57), χ2=7.27, P=0.007] and 30-day [15.8% (9/57) versus 3.5% (2/57), χ2=4.93, P=0.026] mortality of the patients with RDW >14.5% were higher than that of the patients with RDW ≤14.5% . The Kaplan-Meier survival curve showed that the 1-year survival of the patients with RDW ≤14.5% after liver transplantation was better than that of the patients with RDW >14.5% [hazard ratio=4.75, 95%CI (1.78, 12.67), P=0.007], but there were no significant differences between the two groups in the incidence of early graft dysfunction, acute renal injury, renal replacement therapy, and pulmonary complications, as well as postoperative hospital stay and ICU stay (P>0.05). ConclusionPreliminary results of this study indicate that preoperative RDW of patients underwent allogeneic liver transplantation is associated with1-year mortality, 30-day mortality, and 1-year survival.

    Release date:2022-06-08 01:57 Export PDF Favorites Scan
  • THREE-DIMENSIONAL FINITE ELEMENT INVESTIGATION OF LATERAL MASS SCREW FIXATION AND TRANSARTICULAR SCREW FIXATION IN LOWER CERVICAL SPINE

    Objective To establ ish sophisticated three-dimensional finite element model of the lower cervical spine and reconstruct lower cervical model by different fixation systems after three-column injury, and to research the stress distribution of the internal fixation reconstructed by different techniques. Methods The CT scan deta were obtained from a 27-year-old normal male volunteer. Mimics 10.01, Geomagic Studio10.0, HyperMesh10.0, and Abaqus 6.9.1 softwares were usedto obtain the intact model (C3-7), the model after three-column injury, and the models of reconstructing the lower cervical spine after three-column injury through different fixation systems, namely lateral mass screw fixation (LSF) and transarticular screw fixation (TSF). The skull load of 75 N and torsion preload of 1.0 N•m were simulated on the surface of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity of internal fixation system was evaluated. Results The intact model of C3-7 was successfully establ ished, which consisted of 177 944 elements and 35 668 nodes. The results of the biomechanic study agreed well with the available cadaveric experimental data, suggesting that they were accord with normal human body parameters and could be used in the experimental research. The finite element models of the lower cervical spine reconstruction after three-column injury were establ ished. The stress concentrated on the connection between rod and screw in LSF and on the middle part of screw in TSF. The peak values of Von Mises stress in TSF were higher than those in LSF under all conditions. Conclusion For the reconstruction of lower cervical spine, TSF has higher risk of screw breakage than LSF.

    Release date:2016-09-01 09:04 Export PDF Favorites Scan
  • 摆位系统误差对乳腺癌调强放射治疗剂量分布的影响

    目的探究摆位系统误差对乳腺癌患者实施调强放射治疗的剂量学影响。 方法2012年10月对一典型乳腺癌改良根治术后患者分别设计常规三维适形切线野(CRT)、多野静态调强(s-IMRT)、旋转调强(VMAT)3种不同治疗技术的计划,在计划中将治疗中心点向患者左、右、腹、背、头、脚方向分别平移3、6 mm模拟2种不同程度的系统误差,共计39个计划与原计划进行比较,观察不同治疗技术间、不同平移距离,不同方向上的靶区及主要危及器官患侧肺和心脏的剂量变化。 结果对于3 mm摆位系统误差,靶区D95%于向背侧s-IMRT降低4.0%,VMAT降低3.5%,向右(患侧)s-IMRT降低3.0%,VMAT降低2.8%,其余均方向降低且<1.6%。对于主要危及器官,系统误差对s-IMRT技术的患侧肺接受20 Gy剂量的体积影响大,对VMAT技术的患侧肺接受10 Gy剂量的体积影响大。除此外,对主要危及器官患侧肺及其他剂量参数影响均小(3 mm<3%,6 mm<6%)。系统误差对3D-CRT技术的影响小(3 mm<3%,6 mm<6%)。6 mm的系统误差对靶区及危及器官的影响与3 mm趋势一致,仅变化程度更大,两种调强技术的靶区D95%降低>5%。 结论对乳腺癌改良根治术后的呈弧段状、位于胸廓表面的放射治疗靶区,s-IMRT和VMAT方式的调强治疗技术对治疗摆位系统误差的影响程度相当,但较CRT技术更敏感,其中以向患者背侧、健侧方向偏移影响最大。改良根治术后乳腺癌调强治疗的实施需要有较三维治疗更高的位置精度保证。

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  • From Grid Cells to Place Cells: A Gauss Distribution Activation Function Model

    It has been found that in biological studies, the simple linear superposition mathematical model cannot be used to express the feature mapping relationship from multiple activated grid cells' grid fields to a single place cell's place field output in the hippocampus of the cerebral cortex of rodents. To solve this problem, people introduced the Gauss distribution activation function into the area. We in this paper use the localization properties of the function to deal with the linear superposition output of grid cells' input and the connection weights between grid cells and place cells, which filters out the low activation rate place fields. We then obtained a single place cell field which is consistent with biological studies. Compared to the existing competitive learning algorithm place cell model, independent component analysis method place cell model, Bayesian positon reconstruction method place cell model, our experimental results showed that the model on the neurophysiological basis can not only express the feature mapping relationship between multiple activated grid cells grid fields and a single place cell's place field output in the hippocampus of the cerebral cortex of rodents, but also make the algorithm simpler, the required grid cells input less and the accuracy rate of the output of a single place field higher.

    Release date:2016-12-19 11:20 Export PDF Favorites Scan
  • Photoelectric guided navigation unilateral puncture of the percutaneous kyphoplasty in treatment of thoracolumbar osteoporotic vertebral compression fracture

    ObjectiveTo evaluate the safety of photoelectric guided navigation unilateral puncture of the percutaneous kyphoplasty (PKP) in the treatment of thoracolumbar osteoporotic vertebral compression fracture (OVCF).MethodsA randomized controlled clinical research was performed between June 2015 and January 2017. Eighty-five cases of OVCF were treated with photoelectric guided navigation unilateral puncture of the PKP (trial group, 43 cases) or C arm fluoroscopy unilateral puncture of the PKP (control group, 42 cases) respectively. There was no significant difference in gender, age, disease duration, segmental fracture, AO classification, bone mineral density, and preoperative visual analogue scale (VAS) score between 2 groups (P>0.05). The concordance rate of puncture path and design path, the incidence of pedicle wall breaking, the incidence of bone cement leakage, and the rate of bone cement distribution center were observed and calculated on postoperative CT images; the intraoperative X-ray exposure frequency, frequency of puncture, operation time, VAS scores before operation and at 2 days after operation, and postoperative blood vessel or nerve injury were recorded and compared.ResultsThe intraoperative X-ray exposure frequency and puncture frequency in trial group were significantly less than those in control group (P<0.05), but there was no significant difference in operation time between 2 groups (t=0.440, P=0.661). The VAS scores of 2 groups at 2 days after operation were significantly improved when compared with preoperative ones (P<0.05), but there was no significant difference in VAS score at 2 days after operation between 2 groups (t=0.406, P=0.685). All the patients were followed up 6-18 months (mean, 10 months). No blood vessel or nerve injury occurred in 2 groups. The incidence of pedicle wall breaking, the incidence of bone cement leakage, the concordance rate of puncture path and design path, and the rate of bone cement distribution center in trial group were 2.33% (1/43), 2.33% (1/43), 86.05% (37/43), and 88.37% (38/43) respectively, all showing significant differences when compared with those of control group [19.05% (8/42), 21.43% (9/42), 45.24% (19/42), and 50.00% (21/42) respectively] (P<0.05).ConclusionIntraoperative photoelectric guided navigation unilateral puncture of the PKP can improve the success rate of target puncture and reduce the incidence of pedicle wall breaking effectively, and achieve better bone cement distribution and better security.

    Release date:2018-02-07 03:21 Export PDF Favorites Scan
  • The Effect of Anatomical Distribution of Multiple Tumors for HCC Patients Meeting The Milan Criteria after Hepatic Resection

    ObjectiveTo exclusively compare the short-and long-term outcomes of hepatic resection (HR) patients with multifocal tumors meeting the Milan criteria between locating in same and different sections. MethodsA total of 219 consecutive HR patients with multifocal tumors meeting the Milan criteria were divided into group SS (n=97, same section) and group DS (n=122, different sections) according to their anatomical location (Couinaud's segmentation). ResultsThe 1-, 3-, and 5-year overall survival (OS) and recurrence-free survival (RFS) rates were significantly higher in the group SS than those in the group DS (P < 0.05). The subgroup analysis showed that patients with 2 tumors and those undergoing en bloc resection were associated with better OS and RFS (P < 0.05). ConclusionsFor HCC patients with multifocal tumors meeting the Milan criteria, those with tumors locating in same hepatic section may have better longterm survival and lower HCC recurrence rates than those locating in different sections after HR.

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  • Current research status of blood routine indexes in predicting severity of acute pancreatitis

    ObjectiveTo summarize the blood routine indexes and predictive systems that can predict the severity of acute pancreatitis (AP). MethodThe recent domestic and foreign literatures on the predictive value of blood routine indexes for the severity of AP were reviewed.ResultsFrom the current research results at domestic and foreign, independent blood routine indexes such as red blood cell distribution width, average platelet volume, hematocrit (TCT), platelet (PLT) count, platelet distribution width, percentage of immature granulocytes (IG%), and some blood routine calculation indexes such as neutrophil to lymphocyte ratio (NLR), PLT to lymphocyte ratio (PLR), red blood cell distribution width to PLT ratio (RPR), neutrophil-monocyte product, and so on, all had different predictive value for the severity of AP. In addition, multiple prediction modes such as blood routine indexes combined with some serological indexes or other scoring systems could also be used to predict the severity of AP. In general, the predictive value of the NLR, IG%, and HCT on the severity of AP had been unanimously recognized by researchers. However, the conclusions of related studies on the predictive values of PLT, PLR, and RPR on the severity of AP were still controversial. ConclusionsAt present, there are a variety of blood routine indexes can be used to predict severity of AP, but their predictive values are different. Further researches are still needed.

    Release date:2022-03-01 03:44 Export PDF Favorites Scan
  • EFFECT OF METAL IONS Co2+ AND Cr3+ ON OSTEOBLAST APOPTOSIS, CELL CYCLE DISTRIBUTION, AND SECRETION OF ALKALINE PHOSPHATASE

    Objective Metal wear products cause the aseptic loosening of joint prosthesis. To investigate the effect of metal ions Co2+ and Cr3+ on the osteoblast apoptosis, cell cycle distribution, and secretion of alkal ine phosphatase (ALP), and to search a method to prevent and treat aseptic loosening. Methods The mouse calvarial osteoblasts (MC3T3-E1) were cultured in vitro to 3-5 generations (5 × 105 cells/ mL) and divided into 2 groups: the experimental group and the controlgroup. The osteoblasts were cultured in α-MEM medium containing 10%FBS (the control group), and the mixed solution ofCoCl2 and CrCl3 was added after the osteoblasts cultured in α-MEM medium containing 10%FBS attached completely (the experimental group). At 12, 24, and 48 hours after culture, the osteoblast apoptosis and the cell cycle distribution were assessed by flow cytometry; and ELISA method was appl ied to detect ALP content in serum supernatant. Results At 12, 24, and 48 hours after culture, the apoptosis rates in the experimental group (13.90% ± 0.52%, 14.80% ± 0.41%, and 13.40% ± 0.26%) were significantly higher than those in the control group (8.56% ± 0.31%, 8.19% ± 0.24%, and 2.15% ± 0.11%), (P lt; 0.05); G2M (dividing phase) distribution ratio significantly decreased and G0G1 (dormancy stage) distribution ratio significantly increased when compared with those in the control group (P lt; 0.05); and the absorbency (A) values of ALP were 0.955 ± 0.052, 0.624 ± 0.041, and 0.498 ± 0.026 in the exprimental group, and were 1.664 ± 0.041, 1.986 ± 0.024, and 2.192 ± 0.041 in the control group, showing significant differences between 2 groups (P lt; 0.05). Conclusion Metal ions Co2+ and Cr3+ have a marked effect on osteoblasts cell cycle distribution, which can make most of the cells to be in dormancy stage (G0G1), up-regulate the apoptosis rate and inhibit the releasion of ALP from osteoblasts.

    Release date:2016-08-31 05:41 Export PDF Favorites Scan
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