Modeling in Frequency Domain Used for Assessment of In Vivo Dissolution Profile

Purpose. To present a model-dependent approach for the assessment of the in vivo drug dissolution profile based on in vitrodata for the multiple unit dosage form, as an alternative to the numerical method proposed in the study by Hayashi et al, Pharm. Res. 12:1333–1337 (1995). Methods. The data for aspirin granules administered to healthy subjects obtained in the above mentioned study were re-evaluated. The subject dissolution system was considered to consist of two subsystems connected in series, i.e. the subsystem describing the gastric-emptying process and the subsystem describing the intestinal dissolution process. The frequency response method was used to model the subject dissolution system. Results. The model in vivodissolution profile of aspirin, assessed as the integral of the model weighting function of the subject dissolution system, was in agreement with the in vivo cumulative absorption profile calculated by the Wagner-Nelson method. Conclusions. Comparison of dynamic properties of the subject dissolution system with the subsystem describing the gastric-emptying process yielded quantitative confirmation of the decisive role of the gastric-emptying process in the in vivodrug dissolution after administration in the multi unit dosage form.     

基于广义逆的无谱逆反卷积算法

在时域循环卷积运算实现反卷积方法的基础上，基于广义逆的概念提出了一种改进算法，该算法不仅可以有效地避开无谱逆问题，而且运算量增加较少，易于编程实现。     

Significance of beaten copper appearance on skull radiographs in children with isolated sagittal synostosis

Aims and Objectives The significance of beaten copper appearance (BCA) on skull radiographs in children following surgery for isolated sagittal craniosynostosis has not been studied. This study was designed to look for any correlation between BCA and symptoms suggestive of intracranial hypertension in this group of patients. Materials and Methods Forty-eight consecutive children, who were operated for isolated sagittal synostosis from1987 to 2000 and had postoperative skull radiographs, were included. Patients were divided into: (a) BCA group (n = 20), consisting of children who had beaten copper appearance on skull radiographs at last follow up, and (b) Non-BCA group (n = 28), consisting of children who did not have this finding. Records were reviewed to look for symptoms suggestive of intracranial hypertension, such as headache, head banging, and irritability. Results Median age at surgery was 4.8 months for BCA group and 4 months for the non-BCA group. Follow up ranged from 4 to 156 months with a mean of 36.2 months. Total of 28.6% (n = 6) of the children with follow up radiographs done at ≤18 months of age had BCA. The incidence of BCA increased to 83.3% in children with skull radiographs performed after 48 months of age. In 18 (90%) children, the BCA was ‘diffuse’ with 5 (25%) children having the maximum possible score of 8. In the BCA group, 45% (n = 9) had symptoms compared to 10.7% (n = 3) in the control group (p = 0.0068). Conclusions This study suggests a significant number of children with BCA on radiographs develop symptoms suggestive of raised ICP following surgical treatment in infancy and prolonged follow up may be warranted in this group of patients.     

采用修正正交分段线性函数求解时滞系统和卷积的方法

应用修正正交分段线性函数的时滞和反向特性，推导出求解时滞系统和卷积的公式。数字仿真表明，它具有计算简单，精度高的优点。     

Comparison of Simulated and in-Vivo Plasma Levels of Cilastatin Following Intravenous in-Line Drug Administration

The primary objective of this work was to establish a method to simulate the plasma levels of cilastatin, a model drug, following an intravenous in-line delivery scheme. In-vivo data in dogs obtained from this work were used to demonstrate the validity of the proposed approach. The in-line drug delivery system consists of a drug containing device which is placed between a large volume parenteral and a patient. Numerous advantages have been identified for this automatic in-line reconstitution delivery system. The numerical convolution integral algorithm was used in this work to perform plasma profile simulation. The results indicated that the simulated cilastatin plasma profile following in-line delivery closely agreed with the in-vivo data.     

基于卷积神经网络和Transformer的肝脏CT图像分割方法

针对现有的卷积神经网络在肝脏图像分割上精度较低的问题,提出了一种以U-Net网络模型为基础的分割算法。将多头自注意力机制引入到U-Net网络的跳跃连接中,在编码器部分使用空洞卷积,采用混合损失函数从而提高分割精度。在LITS数据集上通过实验结果表明,利用本文方法进行肝脏分割与传统U-Net方法相比Dice系数提升3.3%,平均交并比提升了2.4%,平均像素准确率提升了3.66%。     

Pharmacodynamic Analysis of Analgesic Clinical Trials Using Empirical Methods

Data from analgesic clinical trials have characteristics such as ordered categorical longitudinal responses with repeated measures, delay of effect with respect to analgesic plasma concentration, and right-hand censoring of response due to remedication. In order to determine the concentration-effect relationship of such data, we propose convolving an empirical function for plasma concentration, in the form of broken lines which connect each pair of neighboring observations, with a monoexponential function, to generate effect site concentration Effect site concentration and time are used, simultaneously, as independent variables in the fit of the model for the logit of the probability of having a specific pain relief (PR) score at each time point pre-remedication, via maximum likelihood. Using corresponding effect site concentration, the probabilities of having specific PR scores post-remedication are predicted via the concentration-response relationship established. The overall (pre- and post-remedication) predictions and corresponding standard errors for the responses are then estimated. Inference of the PR scoring, using a posterior method, is proposed. An illustration using real data is used to demonstrate these methods.     

褶合曲线法测定血清中奥沙普秦的浓度

目的：测定血中奥沙普秦的浓度。方法：采用计算机辅助褶合光谱法，结合计算机信息处理技术，应用其单组分定量分析功能系统，对血清中奥沙普秦的浓度进行测定。结果：线性范围是0—28mg.L^-1，回收率为100．0％，RSD为0．014％(n＝5)。结论：本法简便，结果准确，重现性好，可用于血清中奥沙普秦的测定。     

褶合曲线分析法同时测定小儿复方苯巴比妥片中四组分的含量

目的：不经分离同时测定小儿复方苯巴比妥片中四组分的含量。方法：以褶合光谱为基础，结合当前最优秀的数值计算法——偏最小二乘法(PLS法)利用计算机信息处理技术的褶合曲线分析法。结果：小儿复方苯巴比妥片中阿司匹林、非那西丁、咖啡因和苯巴比妥四组分的平均回收率及相对标准偏差(RSD)分别为99．75，0．92％；100．47，0．56％；99．82，1．12％；100．08，0．86％。结论：该方法可以用于小儿复方苯巴比妥片剂的质量监控。     

应用体内外相关性模型研究红霉素缓释微囊的体内外相关性

 目的 对红霉素缓释微囊的体内外相关性进行了研究,并对模型在预测体内数据方面的性能进行了考察。方法 应用美国缓、控释制剂专业委员会推荐的水平A、水平B两种体内外相关的模型。收集红霉素缓释微囊12 h的体外溶出数据。同时以家兔为实验动物,灌服微囊后收集血药浓度。应用水平A相关性模型,采用反卷积方法获得体内吸收百分数,并与体外溶出百分数进行比较。同时进一步运用基本的和扩展的卷积-反卷积方法对微囊的体内外相关性进行研究。对水平B相关性模型在药物相关性研究上的应用也进行了考察。结果 水平A模型和水平B模型都得到比较好的结果。结论 两种模型都能刻画体内外的相关性,水平A相关性模型可以得到较水平B相关性模型更多的关于药物体内外相关性的信息。