拮抗剂方案中应用促性腺激素释放激素激动剂诱发卵母细胞成熟后不同黄体支持方案对妊娠结局的影响——一项提前终止的前瞻随机临床对照研究

目的 (1)在促性腺激素释放激素拮抗剂(GnRH-ant)方案中应用促性腺激素释放激素激动剂(GnRH-a)诱发卵母细胞最终成熟后,在黄体支持方案中比较孕激素+人绒毛膜促性腺激素(HCG)和孕激素+雌激素两种不同的黄体支持方案对妊娠结局的影响;(2)在GnRH-ant方案中比较添加高纯度人绝经期促性腺激素(HP-HMG)和添加人重组黄体生成素(rLH)对妊娠结局的影响.方法 前瞻随机对照的临床实验.对照组32例,添加rLH,GnRH-a诱发卵母细胞最终成熟后12h添加1,000 IU、35 h添加500 IU HCG,取卵后应用孕激素;实验Ⅰ组37例,添加HP-HMG,黄体支持方案同对照组;实验Ⅱ组33例,添加HP-HMG,取卵后应用孕激素和雌激素.结果 对照组、实验Ⅰ组和实验Ⅱ组的新鲜周期胚胎移植周期临床妊娠率分别是38.10％、23.08％和8.70％,实验Ⅱ组新鲜周期临床妊娠率明显低于本中心质控标准,该临床实验提前终止.对照组、实验Ⅰ组和实验Ⅱ组未妊娠者已有33例进行了冷冻胚胎移植周期,其临床妊娠率分别为50.00％,63.64％和57.14％.三组均无中重度卵巢过度刺激综合征(OHSS)发生.结论 拮抗剂方案中应用GnRH-a诱发卵母细胞成熟可以避免中重度OHSS的发生,且不影响胚胎质量.GnRH激动剂诱发卵母细胞成熟对黄体功能和内膜容受性存在不利影响,单纯补充雌孕激素无法替代HCG的作用.     

N-Acetylcysteine for Preventing Pump-Induced Oxidoinflammatory Response During Cardiopulmonary Bypass

Purpose To investigate the effect of N-acetylcysteine on preventing pump-induced oxidoinflammatory response during cardiopulmonary bypass (CPB).Methods Forty patients undergoing coronary artery bypass grafting (CABG) were randomly divided into a study group (n = 20), given 50mgkg^–1 N-acetylcysteine intravenously for 3 days, and a control group (n = 20) given saline. Serum samples were collected for measurement of myeloperoxidase (MPO), malondialdehyde (MDA), interleukin-6, ₁-acid glycoprotein (AAGP), and C-reactive protein (CRP) during surgery and postoperatively.Results The MPO and MDA values showed a similar pattern during and after CPB in the study group, with significantly less variance than in the control group. Interleukin-6 showed similar patterns in the two groups, but the data from 30min after the start of CPB and from 6h post-CPB were significantly different. The AAGP and CRP values were both elevated during CPB in the two groups without a significant difference, but 6 and 24h post-CPB, the values were significantly higher in the control group than in the study group.Conclusions N-Acetylcysteine decreased pump-induced oxidoinflammatory response during CPB, suggesting that it could be a novel therapy for assisting in the prevention of CBP-induced oxidoinflammatory damage.     

High temporal resolution phase contrast MRI with multiecho acquisitions.

Velocity imaging with phase contrast (PC) MRI is a noninvasive tool for quantitative blood flow measurement in vivo. A shortcoming of conventional PC imaging is the reduction in temporal resolution as compared to the corresponding magnitude imaging. For the measurement of velocity in a single direction, the temporal resolution is halved because one must acquire two differentially flow-encoded images for every PC image frame to subtract out non-velocity-related image phase information. In this study, a high temporal resolution PC technique which retains both the spatial resolution and breath-hold length of conventional magnitude imaging is presented. Improvement by a factor of 2 in the temporal resolution was achieved by acquiring the differentially flow-encoded images in separate breath-holds rather than interleaved within a single breath-hold. Additionally, a multiecho readout was incorporated into the PC experiment to acquire more views per unit time than is possible with the single gradient-echo technique. A total improvement in temporal resolution by approximately 5 times over conventional PC imaging was achieved. A complete set of images containing velocity data in all three directions was acquired in four breath-holds, with a temporal resolution of 11.2 ms and an in-plane spatial resolution of 2 mm x 2 mm.     

k-space filtering in 2D gradient-echo breath-hold hyperpolarized 3He MRI: spatial resolution and signal-to-noise ratio considerations.

In this work some of the factors that can influence the signal-to-noise ratio (SNR) and spatial resolution in MR images of inhaled hyperpolarized gases are systematically addressed. In particular, the effects of RF depletion of longitudinal polarization and image gradient diffusion dephasing were assessed in terms of their contribution to a k-space filter. By means of theoretical simulations and a novel method of experimental validation using a variable transverse magnetization of the 1H signal, systematic quantitative and qualitative investigations of the effects of k-space filtering intrinsic to imaging of hyperpolarized gas were made. A 2D gradient-echo image is considered for a range of flip angles with centric, sequential, and half-Fourier Cartesian phase-encoding strategies, and the results are assessed in terms of SNR and spatial resolution in the reconstructed images. Centric phase encoding was found to give the best SNR at higher flip angles, with a trade-off in spatial resolution compared to sequential phase encoding. A half-Fourier approach potentially offers increased SNR through the use of higher flip angles without compromising the spatial resolution, which is comparable to that achieved with sequential encoding.     

含精氨酰-甘氨酰-天冬氨酰序列短肽的合成及应用研究进展

精氨酰－甘氨酰－天冬氨酸（RGD）是具有生物活性的短肽序列之一，它是大多数细胞表面粘附分子能识别的配体上的最小氨基酸序列，在内皮细胞的识别，抗血栓，抑制肿瘤，治疗烧伤和皮肤溃疡等方面有重要的作用，本文综述了近年来国内外对含RGD序列短肽的合成及其应用研究进展。     

Measurement of vessel wall strain using cine phase contrast MRI

PURPOSE: To determine the feasibility of using magnetic resonance imaging (MRI) to non-invasively measure strain in the aortic wall. MATERIALS AND METHODS: Cine phase contrast MRI was used to measure the velocity of the aortic wall and calculate changes in circumferential strain over the cardiac cycle. A deformable vessel phantom was used for initial testing and in vitro validation. Ultrasonic sonomicrometer crystals were attached to the vessel wall and used as a gold standard. RESULTS: In the in vitro validation, MRI-calculated wall displacements were within 0.02 mm of the sonomicrometer measurements when maximal displacement was 0.28 mm. The measured maximum strain in vitro was 0.02. The in vivo results were on the same order as prior results using ultrasound echo-tracking. CONCLUSION: Results of in vivo studies and measurement of cyclic strain in human thoracic and abdominal aortas demonstrate the feasibility of the technique.     

原发性肝癌肿瘤边缘螺旋CT肝双期扫描的表现

目的 :探讨原发性肝癌 (PHCC)边缘螺旋CT肝双期扫描表现特点。材料和方法 :回顾性分析 84例经临床、DSA及病理证实的PHCC边缘肝双期扫描表现。结果 :肝癌边缘形态分为四个类型 :( 1)边缘清楚型 ( 19例 ) ,6例肝动脉期边缘见强化肿瘤血管 ,3例门静脉期边缘部分强化 ;( 2 )完整包膜型 ( 14例 ) ,包膜环形强化门静脉期多见 ;( 3)边缘不清型( 2 7例 ) ,2 4例肝动脉边缘见强化肿瘤血管 ,7例门静脉期边缘部分强化 ;( 4 )混合型 ( 2 4例 )。结论 :螺旋CT肝双期扫描可较好显示PHCC边缘形态特点及血供 ,对了解其生物学特性、介入治疗效果预测有一定临床价值。     

Reactivation during encoding supports the later discrimination of similar episodic memories

Episodic memory is characterized by remembering events as unique combinations of features. Even when some features of events overlap, we are later often able to discriminate among them. Here we ask whether hippocampally mediated reactivation of an earlier event when a similar one occurs supports subsequent memory that two similar but not identical events occurred (mnemonic discrimination). In two experiments, participants viewed objects (Experiment 1) or scenes (Experiment 2) during functional MRI (fMRI). After scanning, participants had to remember whether repeated items had been identical or similar. In Experiment 2, representational similarity between the 1st and 2nd presentation predicted participants' ability to remember that the presentations were different, suggesting that the first item was reactivated while viewing the second. A similar but weaker result was found in Experiment 1 that did not survive correction for multiple comparisons. Furthermore, both experiments yielded evidence that the hippocampus was involved in reactivation; hippocampal pattern similarity (and, in Experiment 2, hippocampal activity during the 2nd presentation) correlated with pattern similarity in several regions of visual cortex. These results provide the first fMRI evidence that hippocampally mediated reactivation contributes to the later memory that two similar, but different events occurred. © 2016 Wiley Periodicals, Inc.     

基于双气相配准定量CT在无症状吸烟者肺小气道病变中的应用

目的 采用CT双气相配准技术对无症状吸烟者的肺小气道病变进行定量分析,并探讨其与肺功能的相关性.资料与方法前瞻性收集延安大学附属医院2019年9月—2020年10月正常健康体检不吸烟者34例、低吸烟指数者28例和高吸烟指数者33例,行呼、吸双相CT扫描,将原始数据导入数字肺定量分析软件进行配准并小气道分析,得出CT定量...     

钆塞酸二钠增强MRI肝胆期高信号病变影像表现与特征分析

目的 探讨钆塞酸二钠（Gd-EOB-DTPA）增强MRI肝胆期高信号病变的影像学特征并进行分型。方法 回顾性纳入经手术病理或典型影像表现及临床随访证实为肝脏局灶性病变的病人124例,平均年龄（55.1±15.8）岁。分析肝脏局灶性病变124个,包括肝细胞癌（HCC）52个、胆管细胞癌（ICC）7个、混合型肝细胞癌-胆管癌（cHCC-CC）4个、转移瘤（HM）6个、局灶性结节增生（FNH）及FNH样变42个、肝腺瘤（HCA）2个、异型增生结节（DN）5个、肝海绵状血管瘤（CHL）6个。所有病人均行肝脏Gd-EOB-DTPA增强MRI检查,观察分析肝胆期高信号病变特征并对其进行分型。同一病变中不同分型间占比的比较采用Fisher确切概率检验。计算肝胆期病灶-肝脏信号强度比（LLR）,不同病变间LLR的比较采用Kruskal-Wallis检验。结果 HCC、ICC、HM、FNH/FNH样变和DN病变中不同分型间占比的差异均有统计学意义（均P<0.05）。HCC病灶中28个可见包膜（53.85%）,各分型中Ⅱb型最多（23/52,44.23%）;ICC病灶中Ⅱa型和Ⅲ型最多（均为3/7,...