Correlation between surface features and hygroscopicities of Achyranthis bidentatae Radix extract powders added with different excipients / 中成药

AIM To investigate the correlation between surface features and hygroscopicities of Achyranthis bidentatae Radix extract powders added with different excipients.METHODS Achyranthis bidentatae Radix aqueous extract was added with crospovidone CL-SF,maltodextrin DE11-14,β-cyclodextrin,Arabic gum,dextrin,mannitol,soluble starch and lactose,respectively,after which extract powders were prepared,and hygroscopicities and morphological changes were determined.Then the surface features of various extract powders were compared by double exponential model.RESULTS Compared with other excipients,soluble starch and β-cyclodextrin could reduce the saturated moisture content of the extract powders more obviously,and crospovidone CL-SF exhibited the strongest inhibitory effect on powder synechia after moisture absorption.No direct relationship between hygroscopicities and specific surface area or pore volume was observed,but specific surface area,pore volume and average particle size demonstrated positive correlations with model parameter A1.CONCLUSION Addition of proper excipients can improve the surface features and hygroscopicities of Achyranthis bidentatae Radix extract powders.

Stretched-exponential model of DWI in differentiating malignant and benign breast lesions / 中国医学影像技术

Objective To investigate the value of stretched-exponential model of DWI in differential diagnosis of benign and malignant breast lesions.Methods Totally 58 patients with 63 breast lesions (33 benign,30 malignant lesions) were enrolled.All the patients underwent multiple b value DWI and dynamic contrast enhancement MRI (DCE-MRI) scans.The values of ADC,DDC and water molecular diffusion heterogeneity index (α) were calculated,and the time signal intensity curve (TIC) was obtained.All the parameters were compared between benign and malignant breast lesions.The diagnostic performance of different parameters was evaluated with ROC curve.Results ADC,DDC and α value of malignant lesions was (1.01±0.19)×10-3 mm2/s,(0.89±0.23)×10-3 mm2/s and 0.75±0.09,while of benign lesions was (1.41±0.27)× 10-3 mm2/s,(1.49±0.29)× 10-3mm2/s and 0.87±0.07,respectively.All 3 parameters in malignant lesions were lower than those in benign lesions (all P＜0.01).Taking 1.22 × 10-3 mm2/s as the optimal threshold,the area under the curve (AUC) of DDC was the largest as 0.958,and the corresponding diagnostic sensitivity and specificity was 96.67％ and 81.82％,respectively.AUC value was 0.976 by combining DDC with TIC,and the corresponding diagnostic sensitivity and specificity was 93.33％ and 93.94％,respectively.Conclusion The stretched-exponential model DWI can differentiate breast lesions,and diagnostic performance of combination of DDC and TIC is better than ADC or DCE.

Evaluation of Two Fitting Methods Applied for Thin-Layer Drying of Cape Gooseberry Fruits

ABSTRACT Drying data of cape gooseberry was used to compare two fitting methods: namely 2-step and 1-step methods. Literature data was also used to confirm the results. To demonstrate the applicability of these methods, two primary models (Page, Two-term-exponential) were selected. Linear equation was used as secondary model. As well-known from the previous modelling studies on drying, 2-step method required at least two regressions: One is primary model and one is secondary (if you have only one environmental condition such as temperature). On the other hand, one regression was enough for 1-step method. Although previous studies on kinetic modelling of drying of foods were based on 2-step method, this study indicated that 1-step method may also be a good alternative with some advantages such as drawing an informative figure and reducing time of calculations.

Imaging of peripheral tissue perfusion parameters in murine hindlimbs using fluorescence reflectance imaging / 国际生物医学工程杂志

Objective To reconstruct the perfusion parameters of murine hindlimbs peripheral tissue by using fluorescence reflectance imaging technique. Methods BALB/c mice were injected with intravenous bolus injection of indocyanine green (ICG) (10μg) into the tail vein. Time-series fluorescence intensity images were obtained for 200 s immediately after the injection. After the serial imaging, silhouette images of the mice were taken under white light to obtain the region of interest (ROI) of the murine hindlimbs. Bi-exponential model was applied to analyze the dynamic fluorescence parameters and the peripheral tissue perfusion parameter images were reconstructed. Results The fitted perfusion curves obtained from bi-exponential model were in good agreement with the measured ones. The parametric images which reflected the vascular sufficiency of murine hindlimbs were reconstructed. Conclusions A novel method for parametric images of murine hindlimbs peripheral tissue blood perfusion is proposed in this paper, which is noninvasive with higher resolution and little damage to biological tissues.

A kind of exponential model of seasickness habituation / 医用生物力学

Objective To provide a quantitative analysis tool by building a mathematical model of seasickness habituation to make adaptive training plans scientifically for anti-seasickness purpose. Methods Based on the regular pattern of seasickness habituation, an exponential model of motion sickness incidence (MSI) was established to extract such seasickness habituation parameters as anti-motion sickness incidence (AMSI) and anti-motion sickness rate (μ) through making the seasickness habituation data fitting into the corresponding training, and the effects of AMSI and μ on MSI was also simulated. Results The data from two marine adaptive trainings were well fitted with the MSI model, and the fitting results of AMSI and μ were 0.87 and 0.048 for intermittent training, or 0.81 and 0.34 for continuous training. Effects of seasickness habituation training would be enhanced by increasing the value of AMSI and μ. Conclusions The present model of MSI is suitable for evaluating the effect of training on anti-seasickness and making the optimal strategy for such seasickness habituation training.

Comparação entre diferentes métodos de análise do componente lento do consumo de oxigênio: uma abordagem no domínio muito intenso de exercício / Comparison between different methods of analysis of slow component of oxygen uptake: a view in severe exercise domain

O objetivo do presente estudo foi comparar, em domínio muito intenso de exercício, diferentes técnicas utilizadas para medir a amplitude do componente lento (CL) da cinética do consumo de oxigênio. Dez ciclistas treinados, do gênero masculino [média ± DP (idade: 25 ± 3,6 anos, massa corporal: 67,2 ± 4,5kg, altura: 174,8 ± 6,5cm e VO2max: 62,4 ± 3,1ml.kg¹.min¹)], realizaram duas idênticas transições de carga constante (intensidade de 75 por centodelta: 75 por cento da diferença entre o VO2 no limiar de lactato e o VO2max) em dias diferentes. O CL foi calculado a partir de diferentes métodos: (1) modelo biexponencial [VO2(t) = VO2base + A1 (1 e-(t-TA1/t1)) + A2 (1 e(tTA2/t2))], (2) intervalos predeterminados (o deltaVO26-2: diferença do VO2 entre o segundo e o sexto minuto de exercício e o deltaVO263: diferença do VO2 entre o terceiro e o sexto minuto de exercício) e (3) diferença entre o VO2 obtido no final do exercício e o valor obtido a partir de um ajuste monoexponencial do "componente primário" (tempo predeterminado de 120s) (CL6"CP"). Todos os métodos foram comparados entre si. Os resultados demonstraram significante subestimação do CL obtido pelo método de intervalos predeterminados (deltaVO26-2: 432 ± 126ml.min¹ e deltaVO263: 279 ± 88ml.min¹) quando comparado com o modelo biexponencial (676 ± 136ml.min¹) e ao CL6"CP" [(719 ± 265ml.min¹ (p < 0,05)]. Não houve diferenças significativas entre as outras comparações. Os resultados sugerem que a utilização de tempos predeterminados pode subestimar o CL quando comparado com o modelo biexponencial e com o CL6"CP".

The objective of the present study was to compare in severe exercise domain, different techniques used for measuring the amplitude of the slow component (SC) of oxygen uptake kinetics. Ten trained cyclists, male (age: 25 ± 3.6 years, body mass: 67.2 ± 4.5 kg, height: 174.8 ± 6.5 cm and VO2max: 62.4 ± 3.1 mL.kg¹.min¹), performed two identical bouts transitions at constant load [mean ± SD (intensity 75 percentdelta: 75 percent of the difference between the VO2 lactate threshold and the VO2max)] in different days. The SC was calculated from different methods: (1) bi-exponential model [VO2(t) = VO2base + A1 (1 e(tTA1/t1)) + A2 (1 e(tTA2/t2))], (2) predetermined intervals (deltaVO262: difference between the second min VO2 and the end VO2; deltaVO263: difference between the third min VO2 and the end VO2) and (3) difference between the end VO2 and the value obtained from a mono-exponential adjustment of the "primary component" (predetermined time of 120 s) (SC6"PC"). All the methods were compared among themselves. The results showed a significant underestimation of the SC obtained by method of predetermined intervals (deltaVO262: 432 ± 126 ml.min¹ and deltaVO26-3: 279 ± 88 ml.min-1) when compared with bi-exponential model (676 ± 136 ml.min-1) and SC6-"PC" [(719 ± 265 ml.min-1 (p < 0.05)]. There was not significant difference among the other comparison. The results suggest that the use of predetermined time may underestimate the SC when compared with bi-exponential model and SC6"PC".

Respiratory respones to sinusoidal work load in man. Relationships among amplitude respones, phase response and aerobic capacity / 体力科学

Amplitude and phase response of ventilation (V<SUB>E</SUB>), carbon dioxide output (VCO<SUB>2</SUB>) and oxygen uptake (VO<SUB>2</SUB>) during sinusoidally varying work load for periods (T) of 1-16 min were studied in six healthy men. The relationships between these parameters and aerobic capacity (VO<SUB>2</SUB>max, ATVO<SUB>2</SUB>) were also examined. The results and conclusions obtained were as follows:<BR>(1) The relationship between the period (T) of exercise and amplitude response of VO<SUB>2</SUB>, VCO<SUB>2</SUB> and V<SUB>E</SUB> was well described by first-order exponential models. However, the relationship between the period of exercise and the phase shift (phase responses of VO<SUB>2</SUB>, VCO<SUB>2</SUB>, and V<SUB>E</SUB>) was better described by complex models comprising a first-order exponential function and a linear equation. This can be explained by Karpman's threshold theory.<BR>(2) High negative correlations were observed between the steady-state amplitude (A) of phase response or the time constants (r) of amplitude response and VO<SUB>2</SUB>max, and ATVO<SUB>2</SUB>. Significantly high negative correlations for all gas exchange parameters may be more rapid in individuals with greater aerobic capacity.<BR>(3) A close relationship between the response of VCO<SUB>2</SUB> and V<SUB>E</SUB> was demonstrated by a higher correlation coefficient than that between VO<SUB>2</SUB> and VCO<SUB>2</SUB> or between VO<SUB>2</SUB> and V<SUB>E</SUB>. This can be partly, but not completely, explained by the cardiodynamic theory.