A few bioinformatics tools have been used to find out conserved regions as probes. We have developed a system based on a heuristic method with web interfaces to find out conserved regions against microbial genomes. The system runs in real time by using relative entropy in limited narrow regions and detecting similar regions between pair regions with local alignment. The system could be useful to find out conserved regions as genome-wide scale.
Computational Biology ; Entropy ; Genome

BACKGROUND: Sevoflurane has been reported to associate with epileptiform activity during a rapidly increasing concentration, but desflurane isn't associated. This study was designed to compare the measured hypnotic levels by using EEG-entropy and bispectral index (BIS) among propofol target-controlled infusion (TCI), sevoflurane and desflurane anesthesia. METHODS: Sixty-five patients undergoing total hysterectomy were studied. Thirty patients were anesthetized with propofol TCI, twenty patients with sevoflurane, and fifteen patients with desflurane anesthesia. BIS, response entropy (RE), state entropy (SE), and hemodynamic variables were collected on the effect site concentrations of 1.5-10.0micro/ml for propofol TCI group. On the other hand, those data were collected on the end-tidal concentrations of 1.0-6.0 vol% for sevoflurane group and, 1.0-13.0 vol% for desflurane group. RESULTS: In propofol TCI group, there was a strong correlation between the measured hypnotic levels and the effect site concentrations of 1.5-10.0micro/ml. Furthermore, the measured values were significantly lower than previous corresponding values on 3.0-4.0 and 8.0micro/ml of the effect site concentrations. In sevoflurane group, the measured hypnotic levels increased paradoxically on the end-tidal concentration of 2.0-5.0 vol%. In desflurane group, the measured hypnotic levels showed ceiling effect in the concentration ranges of 3.0-12.0 vol%. CONCLUSIONS: The measured values by using EEG-entropy and BIS with propofol TCI were considered as useful indices of hypnotic level because of showing a strong correlation. However, those values didn't reflect real clinical hypnotic levels well partly with sevoflurane anesthesia because the measured hypnotic levels increased paradoxically. And it should be considered that those values showed ceiling effect from 3.0 vol% onward with desflurane anesthesia.
Anesthesia* ; Entropy ; Hand ; Hemodynamics ; Humans ; Hysterectomy ; Propofol*

The linear analysis for heart rate variability (HRV), including time domain method, frequency domain method and time-frequency analysis, has reached a lot of consensus. The non-linear analysis has also been widely applied in biomedical and clinical researches. However, for non-linear HRV analysis, especially for short-term non-linear HRV analysis, controversy still exists, and a unified standard and conclusion has not been formed. This paper reviews and discusses three short-term non-linear HRV analysis methods (fractal dimension, entropy and complexity) and their principles, progresses and problems in clinical application in detail, in order to provide a reference for accurate application in clinical medicine.
Electrocardiography ; Entropy ; Fractals ; Heart Rate ; Humans

Vigilance is defined as the ability to maintain attention for prolonged periods of time. In order to explore the variation of brain vigilance in work process, we designed addition and subtraction experiment with numbers of three digits to induce the vigilance to change, combined it with psychomotor vigilance task (PVT) to measure this process of electroencephalogram (EEG), extracted and analyzed permutation entropy (PE) of 11 cases of subjects' EEG and made a brief comparison with nonlinear parameter sample entropy (SE). The experimental results showed that: PE could well reflect the dynamic changes of EEG when vigilance decreases, and has advantages of fast arithmetic speed, high noise immunity, and low requirements for EEG length. This can be used as a measure of the brain vigilance indicators.
Attention ; Brain ; physiology ; Electroencephalography ; Entropy ; Humans ; Mathematics

Geographic distribution of Polyporus umbellatus was predicted by using distribution records. Based on 42 distribution records from 12 provinces and bioclimatic data (1950-2000), georaphic distribution of P. umbellatus was modeled using Maxent. The results showed thatthe Receiver Operating Characteristic (ROC) curve analysis method was used to assess the accuracy of MAXENT model and the area under ROC curve (AUC) value of MAXENT was 0. 960 which suggested that the result of assessment was dependable. The geographic distribution pattern of were divided into three distribution block based on distribution values of 0.5-0.8: small area of Heilongjiang, Jilin, Liaoning and Hebei province, the board area of Yunnan, Guizhou and Sichuan, the southeast area of Tibet and the most area of Shanxi and Shannxi, the southeast board area of Shannxi, Gansu and Ningxia. Jackknife Test showed that average precipitation in warm seasons had the greatest contribution to the distribution gain of P. umbellatus, followed by mean temperature of driest quarter and annual mean temperature. The object suggests the potential distribution areasof P. umbellatus which is useful for the habitat conservation and introduction of P. umbellatus.
China ; Ecosystem ; Entropy ; Polyporus ; growth & development

EEG represents the electric activity of neurons in human brain; it is of course repeatedly used for studying and analyzing the brain activity and the status of brain function. In this paper, we analyzed the patients' and normal persons' EEG in different physiological state, with the aid of two algorithms as a complexity measure. One is Kc complexity defined by Kaspar and Schuster, the other is a new statistical method to measure complexity sequences-Approximate entropy (ApEn). In our work, we analyzed two groups of persons' EEG. Six subjects in 4 different experimental condition are reported. From the results we can discriminate the different state of brain effectively: normal, being injured, and various thinking state. The result suggests that the two algorithms as a complexity measure could be regarded as valued methods in the study of EEG time series and clinical diagnosis.
Algorithms ; Brain ; physiology ; Electroencephalography ; Entropy ; Humans

All the collected original electroencephalograph (EEG) signals were the subjects to low-frequency and spike noise. According to this fact, we in this study performed denoising based on the combination of wavelet transform and independent component analysis (ICA). Then we used three characteristic parameters, complexity, approximate entropy and wavelet entropy values, to calculate the preprocessed EEG data. We then made a distinguishing judge on the EEG state by the state change rate of the characteristic parameters. Through the anesthesia and non-anesthesia EEG data processing results showed that each of the three state change rates could reach about 50.5%, 21.6%, 19.5%, respectively, in which the performance of wavelet entropy was the highest. All of them could be used as a foundation in the quantified research of depth of anesthesia based on EEG analysis.
Anesthesia ; Electroencephalography ; Entropy ; Humans ; Wavelet Analysis

Using the 260 geographical distribution records of Polygonatum cyrtonema in China, combined with 53 environmental factors, the maximum entropy modeling(MaxEnt) was used to study the ecological factors affecting the suitability distribution of P. cyrtonema. The ArcGIS software was used to predict the potential distribution of the population of P. cyrtonema. The dominant factors were chosen by using the Jackknife test and the Receiver Operating Characteristic(ROC) curve was used to evaluate the simulation. The results showed that high value of area under curve(AUC) denoted good results, which significantly differed from random predictions. Based on the evaluation criterion, the accuracies of the predictions of P. cyrtonema potential distribution in the current periods were excellent. The main environmental factors affecting the suitable growth of P. cyrtonema were the monthly precipitation, the wettest monthly precipitation, the annual average temperature range and the precipitation of November, March, February, April, May and October. There are 9 environmental factors in soil type. The potential fitness of P. cyrtonema in China is high, mainly concentra-ted in Hunan, western Hubei, Guangdong, northeastern Guangxi, southeastern Guizhou, Jiangxi, southwestern Anhui, Fujian, Zhejiang, Shaanxi, southwestern Henan and Chongqing. The growth distribution of the potential distribution area of P. cyrtonema was divided, and the zoning map of the growth suitability of P. cyrtonema was formed. Through the comparative analysis of the potential distribution range based on MaxEnt and the distribution range of literature records, the understanding of the distribution range of P. cyrtonema was expanded.
China ; Ecology ; Entropy ; Polygonatum ; Research Design ; Soil

Huocao(a traditional Chinese herbal medicine) moxibustion is a characteristic technology in Yi medicine suitable for cold-dampness diseases. Huocao, as the moxibustion material, is confusedly used in clinical practice and little is known about its quality control. In this study, UPLC method was used to establish the chemical fingerprint of non-volatile components in Huocao, and the contents of eight phenolic acids such as chlorogenic acid were determined. Multivariate statistical analysis was performed to obtain the indicator components of Huocao for quality evaluation, and thus a comprehensive evaluation system for the quality of Huocao was built. The UPLC fingerprints of 49 batches of Huocao were established, and there were 20 common peaks, of which eight phenolic acids including neochlorogenic acid and chlorogenic acid were identified. Except for three batches of Huocao, the similarity of the other 46 batches was higher than 0.89, suggesting that the established fingerprint method could be used for quality control of the medicinal herb. The correlation coefficient between entropy weight score of the eight phenolic acids and comprehensive fingerprint score in Huocao was 0.875(P<0.01), which indicated that the eight phenolic acids could be used as indicator components for the quality evaluation of Huocao. Furthermore, in multivariate statistical analysis on the common peaks of fingerprint and the contents of the eight phenolic acids, chlorogenic acid, isochlorogenic acid A and isochlorogenic acid C were screened to be the indicator components. The results revealed that the proposed method achieved a simple and accurate quality control of Huocao based on UPLC fingerprint and multi-component content determination, which provided useful data for establishing the quality standard of Huocao.
Chlorogenic Acid ; Entropy ; Hydroxybenzoates ; Quality Control

BACKGROUND: Postoperative myocardial ischemia has been regarded as one of the major predictors of adverse cardiac outcomes after noncardiac surgery in high risk patients. Many schemes have been proposed to stratify the potential risk of this patient group in more noninvasive and cost-effective ways and analysis of heart rate variability (HRV) is one of them. To uncover the underlying changes in HRV with postoperative myocardial ischemia five analytical methods were introduced; SDNN (standard deviation of normal to normal intervals), SDANN (standard deviation of the mean of normal RR intervals for each 5 min period of the entire electrocardiographic recording), RMSSD (root mean square successive difference, the squre root of the mean of the sum of the squares of differences between adjacent normal RR intervals over the entire electrocardiographic recording), PNN50 (percent of difference between adjacent normal RR intervals that are greater than 50 ms computed over the entire electrocardiographic recording) for linear time domain analysis and approximate entropy for nonlinear complexity analysis. METHODS: Sixteen vascular surgical patients were monitored by an ambulatory electrocardiogram preoperatively and during the first postoperative day (POD1). HRV values analyzed by five different measures were compared between a control group (C group) of eight patients with no postoperative ischemia and a postoperative ischemic group (PI group) of eight with ischemia on POD1. RESULTS: Approximate entropy was the only measure of HRV which was significantly lower in PI group than that of C group (P< 0.01) on POD1. CONCLUSIONS: Approximate entropy, a complexity measure could provide more sensitive information about the physiologic changes associated with postoperative ischemia which could not be obtained from the conventional HRV measures. Time domain analyses can be used as adjuvant measures providing information about the cardiac autonomic regulation.
Electrocardiography ; Entropy* ; Heart Rate* ; Heart* ; Humans ; Ischemia ; Myocardial Ischemia