It is difficult to select the appropriate ventilation mode in clinical mechanical ventilation. This paper presents a nonlinear multi-compartment lung model to solve the difficulty. The purpose is to optimize respiratory airflow patterns and get the minimum of the work of inspiratory phrase and lung volume acceleration, minimum of the elastic potential energy and rapidity of airflow rate changes of expiratory phrase. Sigmoidal function is used to smooth the respiratory function of nonlinear equations. The equations are established to solve nonlinear boundary conditions BVP, and finally the problem was solved with gradient descent method. Experimental results showed that lung volume and the rate of airflow after optimization had good sensitivity and convergence speed. The results provide a theoretical basis for the development of multivariable controller monitoring critically ill mechanically ventilated patients.
Exhalation ; Humans ; Lung ; physiology ; Models, Biological ; Nonlinear Dynamics ; Pulmonary Ventilation ; Respiration ; Respiration, Artificial ; Tidal Volume

AIM: To study fingerprint and characteristic components of the essential oil of processed Rhizoma Kaempferiae in order to control quality. METHODS: The fingerprint and characteristic components of the essential oil of 10 samples were determined by GC-MS. RESULTS: trans-Ethyl-p-methoxycinnamate,cis-Ethyl-p-methoxycinnamate,trans-Ethylcinnamate,n-Pentadecane,3-Carene,Borneol, 8-Heptadecene,Cyperene,Heptadecane,Globulol,Eucalyptol,cis-Methyl-p-methoxycinnamate and Eucarvone were gained in 10 samples,and relative contents of 13 components added up to 94.5%-98.2% of the total essential oil.The retention time and peak area of 13 components had built the characteristic fingerprint of essential oil of processed Rhizoma Kaempferiae. CONCLUSION: The commercial samples collected from various sources shows a strong similarity.The method has a good repeatability and can be used to control quality of processed Rhizoma Kaempferiae.

Objective: To describe the status of cognition about colorectal cancer and the screening and its relevant factors among first degree relatives of hereditary colorectal cancer patients in Guangzhou. Methods: Totally 274 subjects were investigated by a self-designed demographic questionnaire and the Chinese version of Cognitive Questionnaire for Colorectal Cancer and were analyzed by chisquare test, rank sum test and logistic regressive. Results: 60.2% (165/274) cases had a high level of cognition about colorectal cancer, 23.7% (65/274) had middle level of cognition about colorectal cancer and 16.0% (44/274) had a low level of cognition about colorectal cancer. Multivariate logistic regression analysis showed that age, sex, degree of education, marital status, family income, medical insurance and the number of cancer patients in his family were related factors (P<0.05). People who were young, female, highly educated, high family income, single, public/urban health insurance, commercial insurance and with more than 4 relatives suffering from colorectal cancer have higher cognitive level. Conclusions The level of cognition about colorectal cancer among first degree relatives of hereditary colorectal cancer patients was a little high. Medical staff should pay attention to relevant factors of health belief in subjects and develop targeted intervention to improve the level of cognition among these subjects and to promote their screening behavior.

OBJECTIVES: The incidence of infertility is increasing, more than 30% of them having related abnormal tubal patency. Four-dimensional (4D) hysterosalpingo-contrast sonography (HyCoSy) overcomes the shortcomings of 3D HyCoSy in the diagnosis of tubal patency, showing high specificity and accuracy. In addition, 4D HyCoSy discards iodine allergy and X-ray radiation and possesses easy-operating, contributing to good acceptance in clinical practice. However, there is no research to explore the imaging standards related to the possibility of natural pregnancy after 4D HyCoSy. If a predictive model of postoperative natural pregnancy was established using the analysis of clinical data combined with imaging characteristics of 4D HyCoSy of patients with tubal factor infertility, clinical decision-making can be wisely guided in the future. This study aims to establish a predictive model of natural pregnancy after 4D HyCoSy based on clinical data and imaging characteristics of patients with tubal factor in fertility. METHODS: A retrospective study was conducted for patients who were diagnosed with tubal factor infertility in Hunan Guangxiu Hospital from February 2017 to May 2018. The patients ought to possess complete 4D HyCoSy imaging data and at least one-side-unobstructed fallopian tube. General clinical data and imaging data were collected. Pregnancy outcome was followed up till 3 months after 4D HyCoSy. According to pregnancy outcome, patients were divided into a pregnancy group and a non-pregnancy group. Binary logistic regression was used to analyze the correlation between various variables and natural pregnancy after 4D HyCoSy. The variables with significant difference (P<0.05) in single-factor logistic regression were included in the natural pregnancy probability prediction model. The classification accuracy was further verified with 10-fold cross-validation. RESULTS: A total of 1 085 patients with clinically suspected tubal factor infertility who met the requirements and followed the doctors' prescription were collected. Clinical characteristics (age and duration of infertility) and 4D HyCoSy imaging characteristics (thickness of endometrium from the 3rd to the 7th day after the end of menstruation, visualization of the left fallopian tube, the diffusion of contrast agent around the left ovary, and the diffusion of contrast agent around the right ovary) were independent predictors for natural pregnancy 3 months after 4D HyCoSy. A natural pregnancy probability prediction model was established with the area under the curve (AUC) verified by the 10-fold cross-validation all greater than 0.75, and the best AUC was 0.868. The Q value obtained by the prediction model was the probability of natural pregnancy, and the cutoff value was 0.5. When the Q value was greater than 0.5, it was recommended to attempt natural pregnancy for 3 months, and when the Q value was less than 0.5, in vitro fertilization was adviced. CONCLUSIONS A predictive model for the evaluating probability of natural pregnancy in women with tubal factor infertility after 4D HyCoSy is successfully established based on the analysis for clinical data and imaging characteristics. This model shows a great potential in assisting clinical decision making.
Humans ; Female ; Pregnancy ; Contrast Media ; Retrospective Studies