Dissolution of USP prednisone calibrator tablets: effects of stirring conditions and particle size distribution

We investigate the effect of stirring conditions on the dissolution of United States Pharmacopoeial Convention (USP) prednisone calibrator tablets. The experiments are performed in an automated USP-II dissolution test apparatus. For this study we use a special paddle-propeller, which can be changed from an ordinary paddle to either a pulling or pushing propeller by changing the angle of the paddle blades. According to the dissolution curves obtained we find that the fastest dissolution, and hence best stirring at a certain stirring frequency, is obtained when the blades of the paddle-propeller is about +30°. This setting corresponds to a pushing, downward flow in the centre of the vessel. We show that the shape of the dissolution curves is similar to that expected from a mix of two different fractions of particles, provided that the stirring is sufficiently intense: one fraction, approximately 60 wt.%, with small particles, and one fraction with large particles. The weight of a large particle is about 100–250 times that of a small. We derive a mathematical expression, based on the cube root law, for the dissolution curves. The expression is fitted to the experimental dissolution curves to investigate the variation of key parameters with stirring and temperature.     

基于联机分析处理OLAP技术的医院运营分析管理系统实现与应用

目的:基于联机分析处理(OLAP)技术的医院临床数据中心和信息集成平台的建设,构建应用服务于决策人员的医院运营分析管理系统,优化临床医疗服务质量。方法:采用微软SQL Server数据集成服务(Microsoft SSIS)和微软SQL Server数据分析服务(Microsoft SSAS),以联机事务处理(OLATP)过程设计符合医院专科特色的医院运营数据模型,建设基于OLAP技术的医院运营数据分析管理系统。结果:医院运营管理系统实现了从医院、科室和个人的多维度的联动数据分析,真正意义上实现了数据的结构清晰,来源追溯明确,能够细化地追踪分析从关键绩效指标(KPI)到每一个患者信息,以及每一个收费结算项目的细化追踪及分析,并可追溯解决从各项目终末指标值的趋势分析到发现的数据源头问题的追溯得以解决。结论:通过医院运营管理系统为医院决策层提供了可靠的管理指标数据支撑,有效优化临床医疗服务水平,提高对患者的服务质量。     

Heaviness perception

Weight/aperture (W/A) and weight/square aperture (W/A²) rather than weight (W) previously emerged as possible heaviness models for when a cube is haptically held by thumb–index finger grasp. This is based on the convincing evidence that discernment of a cubes heaviness depends on the integration of sensory information about W and size of finger aperture (A). The present study, therefore, determined which model would be the best predictor for subject-perceived heaviness. Fifteen subjects were asked to judge whether the second of a pair of cubes was heavier, lighter, or identical to the first in 3×3 (density × weight) conditions. The subject responses were compared with the expected responses for each of the possible heaviness models as well as W. The percentage of consistent trials, i.e., subject response matched the expected response, was then compared among the three models and conditions within each model. The results indicated that subject responses were significantly more consistent with the expected responses determined from W/A compared with those determined from W or W/A², suggesting W/A as a best predictor of perceived heaviness by finger-grasp perception. W/A², however, reflected subject responses almost as accurately as W/A could and was, therefore, discussed as one of possible heaviness models when subjects perceive heaviness with different sensory modality.Due to an error in the citation line, this revised PDF (published in December 2003) deviates from the printed version, and is the correct and authoritative version of the paper.     

3D Cube FLAIR plus HyperSense compressed sensing is superior to 2D T2WI FLAIR scanning regarding image quality,spatial resolution,detection rate for cortical microinfarcts

3-dimention (3D) Cube isotropic volumetric magnetic resonance imaging (MRI) facilitates comprehensive recognition of microinfarcts while it takes long scanning time. HyperSense compressed sensing is an emerging technique for accelerating MRI acquisition to reduce scanning time, while its application along with 3D Cube MRI for microinfarcts is seldom reported. Therefore, this study aimed to investigate the efficiency of 3D Cube FLAIR plus HyperSense compressed sensing technique versus conventional 2-dimention (2D) FLAIR scanning in the detection of cortical microinfarcts (CMIs).Totally 59 patients with cerebrovascular disease were enrolled then scanned by 3D Cube FLAIR plus HyperSense compressed sensing and 2D T2WI FLAIR sequences. The image quality scores, signal-to-noise ratio (SNR) for gray matter (GM), SNR for white matter (WM), their contrast-to-noise ratio (WM-to-GM CNR), detected number of CMIs were evaluated.3D Cube FLAIR plus HyperSense showed a dramatically increased scores of uniformity, artifact, degree of lesion displacement, and overall image quality compared to 2D T2WI FLAIR. Meanwhile, it exhibited similar SNRwm and SNRgm, but a higher WM-to-GM contrast-to-noise ratio compared with 2D T2WI FLAIR. Furthermore, the scanning time of 3D Cube FLAIR plus HyperSense and 2D T2WI FLAIR were both set as 2.5 minutes. Encouragingly, 244 CMIs were detected by 3D Cube FLAIR plus HyperSense, which was higher compared to 2D T2WI FLAIR (106 detected CMIs).3D Cube FLAIR plus HyperSense compressed sensing is superior to 2D T2WI FLAIR scanning regarding image quality, spatial resolution, detection rate for CMIs; meanwhile, it does not increase the scanning time. These findings may contribute to early detection and treatment of stroke.     

比较3D各向同性FSE脉冲序列CubeT2与传统2D FSE序列成像质量的差异

目的通过对比分析3D各向同性FSE脉冲序列CubeT2与传统2D FSE序列在颅脑成像质量的差异,探讨更加有效的成像方式。方法收集2017年6月～2019年3月35例来我院行颅脑平扫的患者,分别进行CubeT2序列和常规轴位T2WI序列扫描,然后由两位高级职称影像诊断医师运用感兴趣区(ROI)技术测量计算患者同一层面脑白质信噪比、脑白质与脑灰质对比噪声比,对比CubeT2在成像中的优势。结果 35例受检者分别接受两组序列扫描,CubeT2序列图像脑白质的SNR与常规轴位T2WI序列SNR相比,差异有统计学意义(P0.05);CubeT2序列脑灰质与脑白质CNR与常规轴位T2WI序列相比,差异有统计学意义(P0.05),CubeT2序列获得的病灶数量和信号强度高于常规轴位T2WI序列。结论与2D FSE相比,CubeT2获得的任意平面重建图像在颅脑疾病诊断具有更重要的价值,可作为常规序列的补充。     

Imaging of the wrist at 1.5 Tesla using isotropic three-dimensional fast spin echo cube

Purpose:

To compare three‐dimensional fast spin echo Cube (3D‐FSE‐Cube) with conventional 2D‐FSE in MR imaging of the wrist.

Materials and Methods:

The wrists of 10 volunteers were imaged in a 1.5 Tesla MRI scanner using an eight‐channel wrist coil. The 3D‐FSE‐Cube images were acquired in the coronal plane with 0.5‐mm isotropic resolution. The 2D‐FSE images were acquired in both coronal and axial planes for comparison. An ROI was placed in fluid, cartilage, and muscle for SNR analysis. Comparable coronal and axial images were selected for each sequence, and paired images were randomized and graded for blurring, artifact, anatomic details, and overall image quality by three blinded musculoskeletal radiologists.

Results:

SNR of fluid, cartilage and muscle at prescribed locations were higher using 3D‐FSE‐Cube, without reaching statistical significance. Fluid–cartilage CNR was also higher with 3D‐FSE‐Cube, but not statistically significant. Blurring, artifact, anatomic details, and overall image quality were significantly better on coronal 3D‐FSE‐Cube images (P < 0.001), but significantly better on axial 2D‐FSE images compared with axial 3D‐FSE‐Cube reformats (P < 0.01).

Conclusion:

Isotropic data from 3D‐FSE‐Cube allows reformations in arbitrary scan planes, which may make multiple 2D acquisitions unnecessary, and improve depiction of complex wrist anatomy. However, axial reformations suffer from blurring, likely due to T2 decay during the long echo train, limiting overall image quality in this plane. J. Magn. Reson. Imaging 2011;33:908–915. © 2011 Wiley‐Liss, Inc.     

3D-FSE Cube序列在垂体微腺瘤诊断中的应用价值

目的 评价3D-FSE Cube序列对垂体微腺瘤的诊断价值.方法 对47例垂体微腺瘤的2D-FSE、3D-FSE Cube序列图像进行评分,评价指标如下:①病变与正常垂体的分界;②正常垂体与海绵窦分界;③垂体柄显示;④总体图像质量;⑤磁化率伪影.并计算2组检出率.图像评分应用Wilcoxon符号秩检验.评价者间一致性采用Kappa值表示.P＜0.05有统计学意义.结果 3D-FSE Cube序列在图像质量方面优于2D-FSE序列(P＜0.05),T1 WI的磁化率伪影明显比2D-FSE序列少(P＜0.01).3D-FSE Cube、2D-FSE序列对垂体微腺瘤的总检出率分别为100％(47/47)、85.1％(40/47),其中T1WI的检出率分别为97.9％(46/47)、57.4％(27/47).评价者间一致性较高,T1WI、T2WI的k值分别为0.86、0.88.结论 3D-FSE Cube序列显示垂体微腺瘤明显优于2D-FSE序列,扫描时间缩短20～27s,具有重要的临床应用价值.     

磁共振Bravo序列与Cube Flair序列对肺癌脑转移患者的应用比较

目的比较分析3D Bravo及3D Cube Flair两种MR增强扫描序列对肺癌脑转移检出能力的优劣,优化肺癌脑转移病例的MR检查方案。方法回顾分析25例临床确诊的肺癌患者的MR检查结果,患者MR检查时同时行3D Bravo 及3D Cube Flair两种MR增强扫描序列,比较两者的病灶显示能力并作统计分析。结果3D Cube flair共检出135个病灶,其中脑膜转移灶78个、脑内转移灶57个;3D Bravo共检出91个病灶,其中脑膜转移灶36、脑内转移灶55个。脑膜转移者两种扫描序列相比P＜0.01,有明显差异;脑内转移者两种扫描序列相比P＞0.05,无差异。结论3D Cube Flair增强扫描序列在早期判断肺癌脑转移尤其是早期脑膜转移具有较高应用价值,与3D Bravo扫描序列联合应用对诊断价值更高。