1,9-seco-Bicyclic Polyprenylated Acylphloroglucinols from Hypericum uralum.

Hyperuralones C-H (1-6), six new 1,9-seco-bicyclic polyprenylated acylphloroglucinols (1,9-seco-BPAPs) derived from the normal polyprenylated acylphloroglucinols with a bicyclo[3.3.1]nonane-2,4,9-trione core, together with six known analogues, were isolated from the aerial parts of Hypericum uralum. The structures of 1-6 were elucidated on the basis of the interpretation of NMR and MS spectroscopic data. The structure of attenuatumione B, a known compound isolated from H. attenuatum, was revised to that of a 1,9-seco-BPAP by NMR spectroscopic analysis and previous biomimetic synthesis methods. The inhibitory activities of these isolates on acetylcholinesterase were tested, and compounds 1 and 2 exhibited moderate activities with IC50 values of 9.6 and 7.1 µM, respectively.

Bioactive polyprenylated acylphloroglucinol derivatives from Hypericum cohaerens.

Nine new polyprenylated acylphloroglucinol derivatives, hypercohins B-J (1-9), and nine known analogues were isolated from the aerial parts of Hypericum cohaerens. The structures of 1-9 were elucidated based on spectroscopic analysis, and the absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of these isolates on acetylcholinesterase and five human tumor cell lines were tested, and hypercohins B-D (1-3) exhibited moderate inhibitory activity (IC50 5.8-17.9 µM) against the tested tumor cell lines.

Aircraft engine nozzle guide vane surface temperature optimization.

An optimization method based on the sensitivity of global and local geometric parameters is proposed to improve the cooling efficiency of E3 engine nozzle guide vane. For 29 geometric parameters that affect the vane maximum temperature in the cooling design, the sensitivity ranking of them is firstly obtained by the DOE method. Then the most influential parameters including the diameter or location of the film cooling hole are selected as the optimization variables to decrease the maximum surface temperature of the nozzle guide vane. On this basis, to further reduce the local temperature downstream the pressure side, a new duck-paw type film cooling hole is applied. The duck-paw type film cooling hole was produced with the adjoint method through identifying the sensitivity of the geometric boundary parameters of the film cooling holes. Compared to the cylindrical holes, the duck-paw shaped film cooling hole can greatly improve the cooling efficiency under the same conditions. The duck-paw type film cooling holes are applied to the last two rows of film cooling holes located on the pressure side of nozzle guide vane. Three-dimensional conjugate flow and heat transfer analysis results show that the maximum temperature of the optimized cooling structure vane is reduced by 39K, and the average temperature decreases by nearly 20K.

Investigation on toxicity mechanism of halogenated aromatic disinfection by-products to zebrafish based on molecular docking and QSAR model.

Halogenated aromatic disinfection by-products (DBPs) are a new type of DBPs that have been detected in various water bodies. Previous studies have shown that most of them can induce in vivo toxicity in aquatic organisms. In this study, in order to further investigate the toxic effects and mechanisms of aromatic DBPs, the toxicity and ecological risks of 10 halogenated aromatic DBPs were assessed using the model organism zebrafish. It was found that the toxicity of DBPs was related to the number, type, and position of halogen and the type of substituent, and the 24 h-toxicity value of DBPs in this experiment could replace their 96 h-toxicity value to reduce the test time and save the test cost. Halogenated phenol and halogenated nitrophenol were more toxic, but the current ecological risks of DBPs were relatively low. In addition, the toxicity mechanism of DBPs was analyzed based on molecular docking and quantitative structure-activity relationship (QSAR) models. The molecular docking results showed that all 10 DBPs could bind to zebrafish's catalase (CAT), cytochrome P450 (CYP450), p53, and acetylcholinesterase (AChE), thereby affecting their normal life activities. QSAR models indicated that the toxicity of halogenated aromatic DBPs to zebrafish mainly depended on their hydrophobicity (log D), the interaction with CAT (ECAT), and hydrogen bonding acidity (A).

T-S-Fuzzy-Model-Based Approximation and Controller Design for General Nonlinear Systems.

This paper presents a novel approach to control general nonlinear systems based on Takagi-Sugeno (T-S) fuzzy dynamic models. It is first shown that a general nonlinear system can be approximated by a generalized T-S fuzzy model to any degree of accuracy on any compact set. It is then shown that the stabilization problem of the general nonlinear system can be solved as a robust stabilization problem of the developed T-S fuzzy system with the approximation errors as the uncertainty term. Based on a piecewise quadratic Lyapunov function, the robust semiglobal stabilization and H∞ control of the general nonlinear system are formulated in the form of linear matrix inequalities. Simulation results are provided to illustrate the effectiveness of the proposed approaches.

α-Glucosidase inhibitive diarylheptanoids from Ottelia acuminata var. acuminata, a traditional vegetable of Bai Nationality in Yunnan.

Diabetes is an urgent health issue characterized by ethnic and regional variations, and is inseparable from the different dietary habits. It is worthy to note that the incidence of diabetes in Bai nationality has been reported to be much lower than Han in China. As a daily vegetable of Bai, the phytochemical and antidiabetic study of Ottelia acuminata var. acuminata had not been carried out. In this study, 41 metabolites with diverse diarylheptanoid (six new ones, Otteacumienes A-F), flavone, sesquiterpenoid, coumarin, lignan, polyacetylene, and alkaloid skeletons were characterized from O. acuminata var. acuminata. Among them, the racemic nature of 3 was characterized by chiral resolution and calculated ECD methods. The biological study revealed diarylheptanoids showed significant α-glucosidase inhibitory activities with 5 as the most effective one (60-fold stronger than acarbose). Molecular docking studies indicated that these structures have different binding cavities with acarbose. This study demonstrated that O. acuminata var. acuminata might correlated with the low incidence diabetes of Bai and the diarylheptanoids may have potential therapeutic value for diabetes mellitus.

Sensitivity of PET/MR images in liver metastases from colorectal carcinoma.

Our aim was to evaluate the sensitivity of positron emission tomography/magnetic resonance image (PET/MRI) in the detection of liver metastases in patients from colorectal cancer as compared with computed tomography (CT), magnetic resonance imaging (MRI), PET and PET/CT images. From April 2008 to April 2010, twenty-four patients (mean age 56.5±10.5 years) with liver metastases from colorectal cancer diagnosed by pathology were retrospectively studied as above. All image data were respectively collected and fused. PET/CT and PET/MRI fusion images were successfully performed with a PET-MR-CT robot transmission-fusion imaging system. Pathologic findings and clinical follows-up were performed as referenced standards. Images were reviewed independently by at least three experts. We found a total number of 121 metastatic lesions and 35 of them, with a maximum diameter less than 1cm. According to a per-lesion analysis, the sensitivity on liver metastases was 64.5%, 80.2% and 54.5% on CT, MRI and PET, respectively. Based on reconstruction imaging analysis, PET/CT and PET/MRI showed sensitivities of 84.2% and 98.3%. Sensitivity comparison of PET/MRI had superior sensitivity of 98.08%. Paired data analysis (McNemar) resulted a type I error which equated to 0.05. There was a statistically significant difference between CT and MRI or PET for the detection of patients with liver metastatic lesions (P<0.05). However, PET/MRI can efficiently detect more metastatic lesions than PET/CT (P<0.05) among those with diameter <1cm. In conclusion, PET/MRI was a quite efficient diagnostic modality compared to conventional imaging modalities and should be considered the procedure of choice in the detection of liver metastatic lesions from colorectal cancer.

Interaction between hydrogen sulfide and nitric oxide on cardiac protection in rats with metabolic syndrome.

OBJECTIVE: To investigate the interaction between hydrogen sulfide (H2S)/cystathionine gamma-lyase (CSE) system and nitric oxide (NO)/nitric oxide synthase (NOS) system on cardiac protection in metabolic syndrome (MS) rats. METHODS: Forty one male Sprague-Dawley rats were randomly divided into 6 groups: control group, MS group, H2S donor group, CSE inhibitor group, NOS inhibitor group, and NO donor group. The MS rat model was established by a high-fat diet of 16 weeks. Rats in control and MS groups were subjected to normal saline and the other four groups were respectively subjected to sodium hydrosulfide (NaHS, 56 µmol/kg), D,L-propargylglycine (PPG, 37.5 mg/kg), Nψ-nitro-L-arginine methyl ester (L-NAME, 18 mg/kg), L-Arginine (500 mg/kg) every day. Four weeks later, the obesity indices, blood sugar of oral glucose tolerance test in each time point (0,30,60, and 120 minutes) and blood lipids (cholesterol, triglyceride, high density lipoprotein, low density lipoprotein) were measured. The computer-based electrophysiological recorder system was used to measure the changes of the left ventricular systolic pressure (LVSP), the left ventricular end diastolic pressure (LVEDP), the maximal rate of pressure increase in the contraction phase (+dP/dtmax), and the maximal rate of pressure decrease in the diastole phase (-dP/dtmax). H2S and NO concentration in plasma and myocardium, as well as CSE, constitutive NOS (cNOS), and inducible NOS (iNOS) activities in myocardium were measured with colorimetric method. Reverse transcription-polymerase chain reaction was used to assess the gene expression of CSE and endothelial NOS (eNOS) mRNAs. RESULTS: Compared with control group, the obesity indices, blood sugar at each time point, and blood lipids significantly increased in MS group (P<0.05). H2S and NO concentration in plasma and myocardium, CSE and cNOS activities in myocardium, the expressions of CSE mRNA and eNOS mRNA, and the myocardial function significantly decreased in MS group (P<0.05). Compared with MS group, NO concentration in plasma and myocardium, cNOS and iNOS activities in myocardium, and the expression of eNOS mRNA significantly increased in CSE inhibitor group (P<0.05). However, activities of cNOS and iNOS in myocardium and the expression of eNOS mRNA were significantly decreased in H2S donor group (P<0.01), while the myocardial function significantly increased (P<0.05). H2S concentration in plasma and myocardium, and the expression of CSE mRNA significantly increased in NOS inhibitor group (P<0.05). However, in NO donor group, the CSE activity in myocardium and the expression of CSE mRNA significantly decreased (P<0.05). And the myocardial function was improved significantly (P<0.05). CONCLUSIONS: Both the H2S/CSE and NO/NOS systems appear to have a mutual down-regulation effect on myocardium in MS rats. Meanwhile, exogenous H2S and NO supplement is cardioprotective in rat model of MS.

High-precision half-life measurement of 123Xe and 125Xe for fuel areal density diagnosing in inertial confinement fusion.

The half-lives of 123Xe and 125Xe are important to diagnose deuterium-tritium (DT) fuel areal density in inertial confinement fusion (ICF). In this work, those two half-lives have been measured with HPGe γ-ray spectrometers using the reference source method. Data have been recorded over seven half-lives with three independent measurements for 123Xe and two for 125Xe. New values of 123Xe (2.040 ± 0.009) h and 125Xe (17.048 ± 0.032) h have been determined with significant reduction of the uncertainty compared to the currently recommended value of (2.08 ± 0.02) and (16.9 ± 0.2) h, respectively.

Half-life determination of 88Rb using the 4πß and 4πßγ-coincidence methods.

Samples of 88Rb were produced by the irradiation of U3O8. A series of procedures were applied to extract pure radioactive solution of 88Rb. Experimental data was recorded by a 4πßγ-coincidence measurement system. Two rounds of experiments were performed to obtain four sets of measurement data. The measured half-life of 88Rb obtained from the average of the 4πß and 4πßγ-coincidence methods was 17.78 ± 0.05 min, in good agreement with previously reported values but with a significantly reduced uncertainty.

Half-life determination of 77Kr using the reference source method.

Samples of 77Kr were produced by (n, 2n) reaction with a DT accelerator, the decay of 77Kr has been tracked by the reference source method with three High-Purity Germanium (HPGe) detectors. Experimental data were recorded at regular time intervals during measurements covering more than 600 min. The determined half-life of 77Kr is 71.25 (42) min, which indicated that the most recent values reported in the 1970s and the value recommended by Evaluated Nuclear Structure Data File (ENSDF) may be biased.

[Epidemiological features and changing patterns of intestinal parasitic diseases in Jiangxi Province].

OBJECTIVE: To understand the epidemiological features and changing patterns of intestinal parasitic diseases in Jiangxi Province from 1989 to 2014, so as to provide scientific evidence for formulating the preventive and control strategy for intestinal parasitic diseases. METHODS: The data regarding the status of intestinal parasitic diseases in Jiangxi Province were captured from the 1989 national survey on the distribution of human parasites in China and the 2014 national survey on major human parasitic diseases in China, and the status of human intestinal parasite infections was compared between the two surveys in Jiangxi Province. RESULTS: The prevalence rate of human intestinal parasite infections was 79.59% and 9.64% in Jiangxi Province in 1989 and 2014, with a decline rate of 87.89% during the 25-year period (χ2 = 30 870.5, P < 0.01). There were 24 and 20 species of human intestinal parasites detected in Jiangxi Province in 1989 and 2014, respectively, with totally 26 species detected during the two surveys. In Jiangxi Province, the 3 most highly prevalent human intestinal parasites included Ascaris lumbricoides (71.06%), hookworm (17.61%) and Enterobius vermicularis (17.59%) in 1989, and E. vermicularis (13.73%), hookworm (4.66%), whipworm (0.95%) in 2014. A higher rate of human intestinal parasite infections was found in females than in males in both surveys in Jiangxi Province (P < 0.01), and the prevalence of human intestinal parasite infections reduced by 82.50% to 95.31% in different age groups in Jiangsu Province during the 25-year period. CONCLUSIONS: The prevalence of human intestinal parasite infections shows a remarkable decline tendency in Jiangxi Province, and soil-transmitted nematodes remain the main species of human intestinal parasites in Jiangxi Province.

Positron imaging for verification of irradiation field during radiotherapy.

AIM OF STUDY: The present study was designed to investigate the application of positron images from photonuclear reactions to verify the location of targeted radiation in vivo. MATERIALS AND METHODS: The phantom study was conducted with distilled water, porcine muscle, porcine adipose tissue, and graphite; these subjects were irradiated separately with 50 MV photons generated by an MM50 Racetrack Microtron. The positron emission activity was measured using a Geiger counter, and the radioactive decay curves for each of the irradiated materials were then established. The positron emission tomography (PET) images of the three tissue models were also achieved using the same radiation conditions. The in vivo PET imaging study was also conducted in tumor-bearing rabbits. RESULTS: Our results demonstrated that the PET imaging could be used to verify the position of the irradiation field in vivo. The dose distribution images of photonuclear reactions of 11 C and 15 O were uniform, using 2-Gy 50 MV photons. CONCLUSIONS: The factors influencing the half-life of radiation activity in various tissues were different from the first order kinetic reaction in physics.

[Current status of human hookworm infection in Jiangxi Province in 2014].

OBJECTIVE: To understand the status of human hookworm (Ancylostoma duodenale or Necator americanus) infection in Jiangxi Province. METHODS: A stratified cluster random sampling was conducted based on the geographical location and economic condition in 2014. Kato-Katz's thick smear method was used for stool examinations, and filter paper cultivation was conducted for distinguishing the species of hookworms. RESULTS: A total of 21 615 persons were involved in the investigation, and there were 1 095 persons infected with hookworm with the prevalence of 5.07% (standardized rate of 4.05%). The infection rate of hookworm in Nanfeng County was the highest (13.96%). Most of the infected people had low worm burden (95.43%). The infection rate of hookworm of the female was higher than that of the male (χ2 = 28.03, P < 0.05). The prevalence increased with the age, while the infection rate of hookworm in people at ages of 75 years and higher was the highest (14.79%). Housewife was the highest risk occupation with the infection rate of 7.55%. The differences of infection rates among different educational level groups were significant (χ2 = 135.88, P < 0.05). The prevalence rates of hookworm in different landforms were significantly different (χ2 = 34.37, P < 0.05). The priority species was N. americanus (80.41%) in Jiangxi Province. CONCLUSIONS: The infection rate of hookworm decreases obviously in Jiangxi Province. The high risk groups of hookworm infection are the people with low educational level, female and elder age-group.

[Investigation of Enterobius vermicularis infection in children in Jiangxi Province in 2014].

OBJECTIVE: To know the status of Enterobius vermicularis infection in children in Jiangxi Province in 2014, so as to provide the evidence for the formulation of prevention and control measures. METHODS: A survey was performed according to the scheme of the 3rd Principal Human Parasites of Jiangxi Province in 2014. Based on the ecological regions, a stratified cluster sampling method was applied by the economic and geographic situation. There were 84 survey sites from 28 counties, and the basic data were also collected in the different investigation sites, and the round-end tube adhesive cellophane anal swab was used to examine E. vermicularis eggs for the children aged 3-6 years. RESULTS: A total of 1 486 children aged 3-6 years were detected, the E. vermicularis infection rate was 13.73% (204/1 486), and the infection rates were 13.89% (114/821) and 13.53% (90/665) in the male and female, respectively. The infection rate in the different age groups showed a gradual rise then fall trend, the lowest infection rate was 10.05% (38/378) in the 3-year age group, and the highest infection rate was 18.24% (81/444) in the 5-year age group. The infection rates in the high, medium and low-income survey sites were 13.79% (87/631), 17.23% (51/296), and 11.81% (66/559), respectively. The E. vermicularis infection rates in the 4 ecological regions were from 12.34% to 17.74%, but there was no significant difference among the different ecological regions (P > 0.05). CONCLUSIONS: The status of E. vermicularis infection in children in Jiangxi Province is relatively serious, and therefore, the parasitic disease control sectors should continue to strengthen the monitoring and control work of E. vermicularis infection in children.

[Epidemiological survey on clonorchiasis and awareness of prevention and control knowledge in Xinfeng County of Jiangxi Province].

OBJECTIVE: To understand the epidemic status of clonorchiasis and awareness of prevention and control knowledge in Xinfeng County of Jiangxi Province, so as to provide the evidences for control measures. METHODS: The baseline survey was carried out with a clue in vestigation of raw-fish eating behavior in potential endemic areas in 2016.The residents were examined by stool tests. The metacercariae of Clonorchis sinensis in fish, the rediae and cercariae in freshwater mollusk were detected. The feces samples of cats, dogs and pigs were collected and examined by sedimentation technique. Meanwhile, the epidemic factors, health knowledge and behavior were also surveyed. RESULTS: The residents in 26 villages had the habit of eating raw freshwater fish, and 19.51% of the respondents had this habit. The average infection rates of the population, Parafossarulus striatulus, freshwater fishes and reservoir hosts were 21.56%, 0, 8.24% and 2.27%, respectively. The infection rate of the population increased with age. There was a significant positive correlation between the behavior and the infection rate of the population (r = 0.88, P < 0.01). Only 11.46% of the respondents knew that eating raw-fish might cause C. sinensis infection, and 5.28% of them knew that C. sinensis was harmful to health. CONCLUSIONS: Twenty-six villages in five townships were endemic areas of clonorchiasis in Xinfeng County. The permanent solution of prevention and control of clonorchiasis is to strengthen the health education and change the habit of raw-fish eating gradually.

[Role of new strategy in transmission control of schistosomiasis in Poyang Lake region].

OBJECTIVE: To evaluate the role of new strategy in the transmission control of schistosomiasis in Poyang Lake region. METHODS: The information and epidemic data of schistosomiasis control were collected and analyzed in Poyang Lake region from 2005 to 2016. RESULTS: After eleven years of carrying out the new strategy, thirteen counties achieved the objective of transmission control in Poyang Lake region. In 2016, the number of schistosomiasis cases and human infection rate were 10 301 and 0.03%, decreased by 89.64% and 99.45% compared with those in 2005, respectively. The number of cattle and schistosome -infected cattle were 68 152 and 5, decreased by 50.84% and 99.83% compared with those in 2005, respectively. The average density of Oncomelania hupensis snails was decreased by 61.52%. No schistosome-infected snails were found since 2014. CONCLUSIONS: The new strategy accurately locates the key points and targets of schistosomiasis transmission chain, which has controlled the human and animal's fecal eggs from polluting grassland, and cut off the transmission chain, reduced both the infection rates of human and animal and the re-infection risk, and promoted to achieve the target of schistosomiasis transmission control in Poyang Lake region.

[Trends of soil-transmitted nematode infections in Jiangxi Province].

OBJECTIVE: To analyze the status and trends of soil-transmitted nematode infections in Jiangxi Province from 1989 to 2014, so as to provide the evidence for generating the strategy of soil-transmitted nematode prevention and control. METHODS: The data of three epidemiological surveys on human parasitic diseases (in 1989, 2002 and 2014) were classified and analyzed. The stool examination by Kato-Katz's thick smear method was adopted for the investigation of soil-transmitted nematode infections. RESULTS: The total infection rate of soil-transmitted nematodes decreased by 91.89% from 77.67% in 1989 to 6.30% in 2014, in which the infection rate of Ascaris lumbricoides decreased by 98.78% from 71.11% to 0.87%, the infection rate of Trichuris trichiura decreased by 96.80% from 29.67% to 0.95%, and the infection rate of hookworm declined by 73.57% from 17.63% to 4.66%. The infection rates of soil-transmitted nematodes in the female were higher than those in the male in three surveys. In different ecological districts, the infection rates of soil-transmitted nematodes in the female were also higher than those in the male, except in Zhe-Min Ecological District in 2002 and 2014. A declined trend of the infection was showed in all age-groups in the three surveys, but it slowed down by the growth of age, i.e., the reduction rate was 97.03% in the age group of < 10 years while 80.62% in the age group of >70 years. In 2014, the number of persons infected with soil-transmitted nematodes occupied 65.4% of the whole number of persons infected with intestinal parasites. CONCLUSIONS: The mean infection rates of soil-transmitted nematodes decrease obviously in human population in different ecological districts, but the soil-transmitted nematodes are still the main species in intestinal parasite infections. The sequence of dominant species changes from A. lumbricoides, hookworm and T. trichiura in 1989 to hookworm, T. trichiura and A. lumbricoides in 2014. The rural female and elder people are the key population, while hookworm is the key species for the prevention and control of soil-transmitted nematodes.

[Analysis of results of technique competition for parasitic disease diagnosis in Class A tertiary hospitals in Jiangxi Province, 2015].

OBJECTIVE: To understand the capability of parasitic disease diagnosis among professionals from the clinic laboratory of Class A tertiary hospitals in Jiangxi Province. METHODS: The teams that took part in the competition were formed from 20 Class A tertiary hospitals, with 2 contestants per team. The competition contents included written examination and skill operation. The written examination involved the life cycle of parasites, immunological basis, detecting techniques, etiological diagnosis etc., and the skill operation involved making and dying thin and thick blood smears, making Kato-Katz's fecal thick smears, as well as microscopic examinations of smears. RESULTS: A total of 40 participants took part in the competition. Their total average score was 97.3±22.4 with the pass rate of 15.0%, in which the mean score of theoretical knowledge was 56.6±12.8 with the pass rate of 52.5%, and the mean score of skill operation was 40.8±12.4 with the pass rate of 5.0%. In the written examination, the scoring rate of the life cycle of soil-transmitted helminths was the highest (90.0%), and the rate of the basic knowledge of food-borne parasites was the lowest (31.5%). Both the pass rates of blood smear making and examination were higher than those of Kato-Katz's thick smears, and the differences were statistically significant (both P < 0.05). The detection rates of Plasmodium vivax, Plasmodium falciparum, Plasmodium ovale and negative slides of the contestants were 38.8%, 45.0%, 35.0% and 25.0% respectively. As to the microscopic examination of helminth eggs, the detection rate of Trichuris trichiura egg was the highest (87.5%), and the rate of the Sparganum mansoni egg was the lowest (2.5%). The scores of Kato-Katz's thick smear making and examination of the contestants from the provincial level hospitals were higher than those from the city level hospitals (both P < 0.05), and the score of those from teaching hospitals in Kato-Katz's thick smear making was higher than that of those from non-teaching hospitals (P < 0.05). CONCLUSIONS: The technique level of professionals from the clinic laboratory of the Class A tertiary hospitals cannot meet the needs of the diagnosis of parasitic diseases in Jiangxi Province, which should arouse the attention of the health authorities and hospitals.