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排序方式: 共有4103条查询结果,搜索用时 15 毫秒
1.
《Medical engineering & physics》2014,36(6):786-792
The key point to calculate augmentation index (AIx) related to cardiovascular diseases is the precise identification of the shoulder point. The commonly used method for extracting the shoulder point is to calculate the fourth derivative of the pulse waveform by numerical differentiation. However, this method has a poor anti-noise capability and is computationally intensive. The aims of this study were to develop a new method based on the 2nd-order B-spline wavelet for calculating AIx, and to compare it with numerical differentiation and Savitzky–Golay digital differentiator (SGDD). All the three methods were applied to pulse waveforms derived from 60 healthy subjects. There was a significantly high correlation between the proposed method and numerical differentiation (r = 0.998 for carotid pulses, and r = 0.997 for radial pulses), as well as between the proposed method and the SGDD (r = 0.995 for carotid pulses, and r = 0.993 for radial pulses). In addition, the anti-noise capability of the proposed method was evaluated by adding simulated noise (>10 Hz) on pulse waveforms. The results showed that the proposed method was advantageous in noise tolerance than the other two methods. These findings indicate that the proposed method can quickly and accurately calculate AIx with a good anti-noise capability. 相似文献
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目的 采用非标志点法构建三维头颅的正中矢状面(MSP),建立技术流程,评价其准确性.方法 选取30名志愿者CT数据,采用非标志点法(实验组)和传统方法(对照组)分别构建头颅的正中矢状面.实验法采用Mimics 11.0软件,通过CT三维重建,镜像,本体-镜像数据配准等步骤构建MSP.对照组手工选取鼻根点、蝶鞍中心点和枕骨大孔最前点构建MSP.由10位正颌外科高年资医生,采用双盲法对实验组、对照组MSP构建结果进行主观评分.采用SPSS 17.0软件进行统计学分析.结果 实验法构建MSP平均得分为84.4±10.9,对照法构建MSP平均得分为66.2±29.2.实验法得分高于对照法,差异具有统计学意义(P<0.001).结论 基于本体-镜像关联法和迭代最近点算法配准的非标质点法能够构建三维头颅的MSP,其准确性优于传统点构建法方法,具有临床可行性. 相似文献
4.
《Acta biomaterialia》2014,10(2):968-974
Nanoscale surface modification of biomedical implant materials offers enhanced biological activity concerning protein adsorption and cell adherence. Nanoporous anodic alumina oxide (AAO) layers were prepared by electrochemical oxidation of thin Al-seed layers in 0.22 M C2H2O4, applying anodization voltages of 20–60 V. The AAO layers are characterized by a mean pore diameter varying from 15 to 40 nm, a mean pore distance of 40–130 nm, a total porosity of ∼10% and a thickness of 560 ± 40 nm. Zeta potential and isoelectric point (iep) were derived from streaming potential measurements and correlated to the topology variation of the nanoporous AAO layers. With decreasing pore diameter a shift of iep from ∼7.9 (pore diameter 40 nm) to ∼6.7 (pore diameter 15 nm) was observed. Plain alumina layers, however, possess an iep of ∼9. Compared to the plain alumina surface an enhanced adherence and activity of hFOB cells was observed on the nanoporous AAO after 24 h culture with a maximum at a pore size of 40 nm. The topology-induced change of the electrochemical surface state may have a strong impact on protein adsorption as well as on cell adhesion, which offers a high potential for the development of bioactive AAO coatings on various biomaterial substrates. 相似文献
5.
Wen-Ke Cai Jia-Ji Lin Gong-Hao He Hua Wang Jun-Hua Lu Guang-Shun Yang 《International journal of clinical and experimental pathology》2014,7(11):7890-7898
To investigate the appropriate cutoff point of CA19-9 for prognosis and other potential prognostic factors that may affect survival of patients with hilar cholangiocarcinoma (HC) after radical surgery. 168 patients who had undergone radical surgery for hilar cholangiocarcinoma and resultant macroscopic curative resection (R0 and R1) were discreetly selected for analyses. Categorized versions were used in univariate model to determine the appropriate cutoff point of CA19-9. CA19-9 and other clinicopathologic factors were analyzed for influence on survival by univariate and multivariate methods. The strongest univariate predictor among the categorized preoperative CA19-9 measures was CA19-9 less than 150 IU/L (P = 0.000). In univariate analysis, tumor size, Bismuth-Corlette classification, portal vein invasion, Lymph node metastasis, resection margin and preoperative CA19-9 levels were identified as significant prognostic factors. In multivariable analysis, lymph node metastasis, resection margin and preoperative CA19-9 levels were independent prognostic factors. our results demonstrated that preoperative CA19-9 levels was also an independent prognostic factor for hilar cholangiocarcinoma, and the most discriminative cutoff point of CA19-9 for prognosis proved to be at 150 U/ml. 相似文献
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《Journal of pediatric urology》2014,10(4):744-748
ObjectiveWe report new hydronephrosis or VUR (vesicoureteral reflux) in patients with end filling pressures >40 cm for at least 1 year after bladder neck surgery without augmentation for neurogenic incontinence.MaterialsConsecutive children with neurogenic sphincteric incompetency had bladder neck surgery without augmentation. Postoperative renal sonography and fluoroscopic urodynamics were done at 6 months, 12 months, and then annually. Those with sustained end fill pressures >40 cm for ≥1 year were included as participants in the study.ResultsOf 79 patients, 17 (22%) had end fill pressures >40 cm for at least 1 year despite anticholinergics, with follow-up a mean of 39 months. New hydronephrosis or VUR developed in six (35%). All new hydronephrosis resolved with medical treatment, as did two out of three new VUR cases. The other patient with VUR had successful Dx/HA (dextranomer hyaluronic acid) injection.ConclusionsDespite sustained pressures >40 cm, upper tract changes developed in only 35% of patients, and resolved with medical management or minimally invasive interventions. End pressures should not be used as an independent indication for augmentation. 相似文献
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María Fernanda Urquiza Inés Carretero Paola Rita Cano Carabajal Rodolfo Agustín Pasqualini María Macarena Felici Rodolfo Sergio Pasqualini Carlos José Quintans 《Journal of assisted reproduction and genetics》2014,31(11):1553-1555
ObjectiveTo report a birth of a healthy girl after long-term oocyte cryopreservation by slow cooling in sodium depleted medium.DesignClinical application.SettingUniversity Affiliated, Private IVF center.PatientA 38-year-old woman received embryos from IVF by intracytoplasmic sperm injection (ICSI) with her own oocytes that were cryopreserved by slow freezing in a low-sodium medium 14 years and 6 months before, when she was 24 years old.Result(s)From six metaphase-II oocytes thawed, two survived, one was fertilized after ICSI and a cleaving embryo was transferred on day 3. A single term pregnancy was achieved, ending with the delivery of a healthy girl.Conclusion(s)Cryopreservation after slow freezing in a sodium depleted medium maintained the developmental competence of oocytes after long-term storage and resulted in a successful live birth. As far as is known, this case represents, up to date, the longest storage period of cryopreserved human oocytes resulting in a live birth. 相似文献
9.
《Gynécologie, obstétrique & fertilité》2014,42(10):721-724
This work aims to show, from data available in the literature and our own experience, how embryos’ vitrification change and/or improve the management of infertile couples. In all, 652 cycles of frozen-thawed embryo transfers (FET) following vitrification were prospectively included and compared with 1126 FETs from slow freezing (SF) method. Primary end points were the (i) survival rate (SR) (% of embryos with > 50% post-thaw intact blastomeres) and (ii) intact survival rate (ISR) (% of embryos with 100% post-thaw intact blastomeres). Secondary end point was the clinical pregnancy rate (CPR) defined as the presence of an intra uterine gestational sac with positive foetal heart beat. In all, 1097 and 2408 embryos have been thawed following vitrification and SF, respectively. We observed a highly significant increase of SR and ISR respectively when thawing concerned vitrified embryos rather than those from SF method (97.0% vs. 72.7%, P < 10−4; 91.5% vs. 49.8%, P < 10−4). Furthermore, CPR were of 26.5% (73/652) and of 18.1% (204/1126) following FETs performed after vitrification or SF and thawing (P = 0.0002), respectively. At the blastocyst stage, ISR was significantly improved following vitrification compared to SF (94.5% vs. 21.4%, P < 10−4). In the study period, vitrification (i) reduced the mean number of fresh transferred embryos (1.5 vs. 1.6; P = 0.08) and (ii) increased the rate of FETs at the blastocyst stage when compared with the control period (18.1% vs 2.5%., P < 10−4). Embryo vitrification preserves all embryos from an ART cycle because of its excellent results regarding ISR at all stages of embryo development. This procedure allows a significant increase of pregnancy rates after thawing. In addition, there is a trend for increasing ART cycles performed using extended culture embryo and vitrification. The expected improvement of the cumulative birth rate at the blastocyst stage following vitrification remains to be demonstrated in a prospective randomized study. 相似文献
10.
目的:探讨感染性畸形中央尖应用3种不同糊剂治疗的临床效果。方法:将150例(161颗)感染性畸形中央尖患者按照随机数字表法随机分为3组,每组50例。以接受氢氧化钙糊剂治疗者为A组(54颗患牙),以接受抗生素糊剂治疗者为B组(55颗患牙),以接受Vitapex糊剂治疗者为C组(52颗患牙)。对比3组感染治疗情况及感染治疗总有效率。结果:治疗后红肿消退、咀嚼功能正常及牙周病变消失时间B组为(4.22±1.15)天、(7.11±1.62)天及(8.12±2.17)天,C组为(4.16±1.11)天、(6.92±1.06)天及(8.15±2.11)天,均低于A组的为(7.25±2.16)天、(9.26±2.71)天及(10.16±3.25)天(P0.05),而B组与C组比较未见统计学差异(P0.05)。同时B组及C组感染治疗总有效率分别为88.00%及94.00%明显优于A组的64.00%(P0.05),B组与C组比较未见统计学差异(P0.05)。同时1年随访显示,B组及C组龋齿发生率明显低于A组(P0.05)。结论:抗生素糊剂及Vitapex糊剂均可显著提高感染性畸形中央尖患牙的临床治疗效果,并可降低患者龋齿的发生率。 相似文献