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The composition of the traditional Chinese medicine compound preparation is complex, while the content of each active ingredient is extremely low, which brings difficulties to the plasma concentration detection. In this study, the magnetic covalent‐organic frameworks were synthesized by a simple one‐step Schiff base reaction and applied for the specific extraction of trace angoroside C in rat plasma prior to ultra‐high‐performance liquid chromatography–tandem mass spectrometry detection. The synthesized magnetic covalent‐organic frameworks have high magnetic responsiveness (35.67 emu·g–1), large surface area (110.9 m2·g–1), and strong stability. The as‐prepared material can quickly extract angoroside C from plasma with high extraction efficiency, be easily separated with a magnet afterward, and can be reused for at least five times. The established method was systematically validated showing good linearity (0.1–5 ng·ml–1), low limit of quantification (0.1 ng·ml–1), good accuracy (93.18–105.36%), and good precision (percentage relative standard deviation 3.60–10.90%). Finally, the method was used to the pharmacokinetic study of trace angoroside C in rats after oral administration of Xuanbo Shuangsheng Granule. [ABSTRACT FROM AUTHOR]

Sodium zirconium cyclosilicate (SZC) is an effective potassium binder for patients with hyperkalemia. This single‐center, open‐label, phase I study (NCT03283267) characterized the pharmacodynamics and safety of SZC in Chinese individuals. Twenty‐two healthy Chinese adults (mean age, 33.5 years) randomized 1:1 received daily oral SZC 5 or 10 g for 4 days, following 4 days on a low‐sodium, high‐potassium diet (continued throughout the study). End points were mean change from baseline in 24‐hour urinary potassium (primary) and sodium excretion, and serum potassium concentration. Urinary potassium excretion significantly decreased with SZC 5 g (mean change [mmol], –13.0; P <.001) and 10 g (–15.4; P <.001). Although urinary sodium excretion decreased significantly with SZC 5 g (–11.5; P =.030), there was no significant change with SZC 10 g (–5.1; P =.299). Serum potassium concentrations decreased significantly with SZC 5 g (–0.14; P =.031) and 10 g (–0.20; P =.002). All treatment‐emergent adverse events were mild, and none were considered causally related to SZC. Over 4 days, the pharmacodynamics and safety of SZC were consistent in healthy Chinese adults with global studies and patients of Japanese ethnicity. [ABSTRACT FROM AUTHOR]

Aims Methods Results Conclusions The present study aimed to quantitatively investigate the potential drug–drug interaction (DDI) mechanism between meropenem (MEPM) and valproic acid (VPA).In the present study, we firstly developed a physiologically based pharmacokinetic (PBPK) model of MEPM and VPA. The verified PBPK model was then used to quantitatively investigate the potential DDI between MEPM and VPA. The effect of genetic polymorphisms of acylpeptide hydrolase (APEH) on DDI was also evaluated.In our simulation, the plasma concentration of hydrolysate of VPAG decreased to 63% when combined with MEPM. Total plasma concentration of VPA before carbapenem use was 53.61 mg/L, whereas it was 45.42 mg/L during carbapenem use. The inhibition of hydrolysis of VPAG by MEPM alone could not result in a rapid and substantial decrease in the plasma concentration of VPA. Parameter sensitivity analysis showed that the changes of absorption played an important role in the maximum plasma concentration (Cmax) of VPA, whereas area under the plasma concentration–time profile (AUC) was more susceptible to elimination changes. In addition, a decrease in APEH activity had little impact on the plasma pharmacokinetics of VPA.The DDI between MEPM and VPA might be a comprehensive result of multiple factors. On the basis of our simulation, interval medication of MEPM injection and VPA immediate release tablet at 4–6 h timed interval was recommended, or intravenous administration of VPA solution was preferred when combination regimen was necessary in a clinical setting. [ABSTRACT FROM AUTHOR]

More than 60 million children have been left behind in rural China by parents going to work in cities. Given the effects of child–parent separation (CPS) on development, this phenomenon has drawn considerable governmental and academic attention in recent years. Outlining developments with reference to relevant studies, this review characterizes the perspectives used to explore and understand this phenomenon in terms of three major paradigms: (1) the diagnostic approach, which takes for granted the assumption that CPS would be the only cause of negative effects observed among left‐behind children (LBC), and has focused primarily on measuring psychological and behavioral disorders among these "problematic kids"; (2) the advanced diagnostic approach, which refines the previous approach by incorporating theories and techniques developed outside of China, elaborating on the early approach by bringing into consideration more factors and exploring the interactions between CPS and these factors, particularly social ones; (3) the sociologically oriented approach, which provides the research with a much broader framework in terms of how to orient the phenomenon of LBC, especially the transformation of China's social and economic systems during the last 30 years of urbanization, where the reproduction of labor has been based on a "splitting family structure," such that problems associated with the phenomenon of LBC cannot be solved without systematic social and economic changes. Based on these analyses, future directions for research on LBC in China are also discussed. [ABSTRACT FROM AUTHOR]

This article investigates the potential of fMRI to test assumptions about different components in models of complex cognitive tasks. If the components of a model can be associated with specific brain regions, one can make predictions for the temporal course of the BOLD response in these regions. An event-locked procedure is described for dealing with temporal variability and bringing model runs and individual data trials into alignment. Statistical methods for testing the model are described that deal with the scan-to-scan correlations in the errors of measurement of the BOLD signal. This approach is illustrated using a “sacrificial” ACT-R model that involves mapping 6 modules onto 6 brain regions in an experiment from Ravizza, Anderson, and Carter (in press) concerned with equation solving. The model's visual encoding predicted the BOLD response in the fusiform gyrus, its controlled retrieval predicted the BOLD response in the lateral inferior prefrontal cortex, and its subgoal setting predicted the BOLD response in the anterior cingulate cortex. On the other hand, its motor programming failed to predict anticipatory activation in the motor cortex, its representational changes failed to predicted the pattern of activity in the posterior parietal cortex, and its procedural component failed to predict an initial spike in caudate. The results illustrate the power of such data to direct the development of a theory of complex problem solving, both at the level of a specific task model as well as at the level of the cognitive architecture. [ABSTRACT FROM AUTHOR]

A method to extract the subject's overt verbal response from the obscuring acoustic noise in an fMRI scan is developed by applying active noise cancellation with a conventional MRI microphone. Since the EPI scanning and its accompanying acoustic noise in fMRI are repetitive, the acoustic noise in one time segment was used as a reference noise in suppressing the acoustic noise in subsequent segments. However, the acoustic noise from the scanner was affected by the subject's movements, so the reference noise was adaptively adjusted as the scanner's acoustic properties varied in time. This method was successfully applied to a cognitive fMRI experiment with overt verbal responses. Magn Reson Med 53:739-744, 2005. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]