BACKGROUND Prior studies have noted great variability in the plasma levels of risperidone(RIS).Plasma concentrations of RIS and its active moiety are highly variable and depend on absorption,metabolism,and other predi...BACKGROUND Prior studies have noted great variability in the plasma levels of risperidone(RIS).Plasma concentrations of RIS and its active moiety are highly variable and depend on absorption,metabolism,and other predictors of metabolic dysregulation;however,these factors are poorly understood and the association between metabolic change and change in psychopathology is uncertain.AIM To ascertain the characteristics of chronic schizophrenic patients treated with RIS,and to assess their relationship with plasma RIS levels.METHODS This was a descriptive cross-sectional study of 50 patients with a diagnosis of schizophrenic psychosis treated with RIS in a psychiatric service.The plasma concentrations of RIS and its metabolite 9-hydroxyrisperidone were determined by high performance liquid chromatography.The patients’demographic and clinical characteristics,and psychopathologies were assessed,and the associations between clinical variables and plasma levels of RIS were explored.RESULTS Male patients received higher doses of RIS than female ones,but plasma concentrations of RIS and risperidone+9-hydroxyrisperidone(active moiety)were higher in female patients.Age and the mean scores of the general psychopathology subscale of the Positive and Negative Syndrome Scale(PANSS)were significantly positively correlated with plasma concentrations of risperidone+9-hydroxyrisperidone adjusted for weight and dose in all 50 subjects.In male subjects,we found a statistically significant positive correlation between the concentrations of risperidone+9-hydroxyrisperidone in plasma/(dose×kg)and age,mean PANSS negative subscale scores,mean PANSS general psychopathology subscale scores,and mean PANSS total scores.CONCLUSION Long-term use of RIS should be closely monitored in older patients and females to minimize the risk of high concentrations which could induce side effects.展开更多
In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were system...In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate.展开更多
A method for determination of lycopene concentration in dog plasma wasestablished. Methods RP-HPLC was used; the mobile phase consisted of methanol-acetonitrile-methylenechloride (40:30:30, V/V) , the wavelength of de...A method for determination of lycopene concentration in dog plasma wasestablished. Methods RP-HPLC was used; the mobile phase consisted of methanol-acetonitrile-methylenechloride (40:30:30, V/V) , the wavelength of detection was 472 nm, the column temperature wasambient temperature, and the flow rate was 1.0 mL·min^(-1). Results The standard curve was linearin the range from 0.012 4 to 0.496 μg·mL^(-1) with r=0.9992. The average extraction recovery was97.6% +-4.2%. The intra-day and inter-day RSD were 1.52% -4.95% and 2.31% -7.38%, respectively.Conclusion This method is sensitive, rapid, reproducible, and of good selectivity for the analysisof lycopene in dog plasma.展开更多
Background: This study was designed to evaluate the efficacy of DL-selenomethionine (DL^SeMet) supplementation on growth performance, antioxidant status, plasma selenium (Se) concentration, and immune function of...Background: This study was designed to evaluate the efficacy of DL-selenomethionine (DL^SeMet) supplementation on growth performance, antioxidant status, plasma selenium (Se) concentration, and immune function of weaning pigs. 216 weaning pigs were randomly allocated to 6 treatments with 6 replicates each according to a complete randomized block design. Each replicate had six pigs. Diet of group one was corn-soybean basal diet without any additional Se supplement. Group 2 was supplemented with 0.3 mg/kg of Se from sodium selenite. Groups 3-6 were supplemented with 0.1, 0.3, 0.5, and 0.7 mg/kg of Se from DL-SeMet, respectively. The trial lasted for 42 days. Results: Pigs supplemented with 0.3 and 0.7 mg/kg DL-SeMet obtained better feed gain ratio (P 〈 0.05). The best antioxidant ability (serum, liver, and muscle) was shown in 0.1-0.3 mg/kg DL-SeMet groups (P〈 0.05). The plasma Se concentration increased as the dietary DL-SeMet level elevated. The immunity among groups was not affected. Conclusions: DL-SeMet supplementation in the diet significantly improved the growth performance, antioxidant ability and plasma Se content of weaning pigs. DL-SeMet can replace sodium selenite in the diet of weaning pigs.展开更多
Objectives To study the relationship between plasma hemoglobin concentration and estimated glomerular filtration rate (eGFR) in elderly patients with ischemic cardiomyopathy (ICM).Methods Clinical data of patients...Objectives To study the relationship between plasma hemoglobin concentration and estimated glomerular filtration rate (eGFR) in elderly patients with ischemic cardiomyopathy (ICM).Methods Clinical data of patients with coronary heart disease who were discharged from The First Affiliated Hospital,Chongqing Medical University between 2005 and 2007 were analyzed retrospectively. Echocardiography results,plasma hemoglobin and creatinine concentration were abstracted from the medical records.The study included 235 Chinese Hart patients with age 60 years and older with angiography confirmed coronary heart disease,silent myocardial ischemia or angina pectoris,of whom 154 had ICM defined as left ventricular end-diastolic diameter (LVDd),male≥56 mm,female≥51 mm (63. 51±7.70 mm) measured by M-mode echocardiography.The differences in plasma hemoglobin concentration were analyzed retrospec- tively between patients with and without ICM,and between patients with an eGFR【60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> and those with an eGFR≥60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup>.Results There were no significant differences in plasma hemoglobin concentration and eGFR between ICM and non-ICM group (118.49±20.52 g·L<sup>-1</sup> vs.115.80±23.32 g·L<sup>-1</sup> and 75.13±24.21 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> vs.79.09±28.41 ml·min<sup>- 1</sup>·1.73m<sup>-2</sup>,respectively,both P】0.05).However,in both ICM and non-ICM groups,plasma hemoglobin concentration was lower in those with an eGFR【60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> compared with compared with those with an eGFR≥60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> group (112. 29±18.61 g·L<sup>-1</sup> vs.119.92±20.74L<sup>-1</sup>,P【0.05);plasma hemoglobin concentration was related positively to eGFR.Conclusions There were no significant changes in plasma hemoglobin concentration and eGFR;however,plasma hemoglobin concentration was related to eGFR significantly positively in elderly patients with ICM due to coronary heart展开更多
Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide.The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina(APS)coatings on AZ31B magnesium alloy was investigate...Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide.The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina(APS)coatings on AZ31B magnesium alloy was investigated using immersion corrosion test in NaCl solutions of different chloride ion concentrations viz.,0.01 M,0.2 M,0.6 M and 1 M.The corroded surface was characterized by an optical microscope and X-ray diffraction.The results showed that the corrosion deterioration of uncoated and coated samples were significantly influenced by chloride ion concentration.The uncoated magnesium and alumina coatings were found to offer a superior corrosion resistance in lower chloride ion concentration NaCl solutions(0.01 M and 0.2 M NaCl).On the other hand the coatings and Mg alloy substrate were found to be highly susceptible to localized damage,and could not provide an effective corrosion protection in solutions containing higher chloride concentrations(0.6 M and 1 M).It was found that the corrosion resistance of the ceramic coatings and base metal gets deteriorated with the increase in the chloride concentrations.展开更多
Two materials, pure Fe and pure Al, were nitrided in a pulse plasma nitriding facility. The nitrogen profiles in surface layers and the surface phase structures of specimens nitrided at 500℃ for 8 h for Fe and for 6 ...Two materials, pure Fe and pure Al, were nitrided in a pulse plasma nitriding facility. The nitrogen profiles in surface layers and the surface phase structures of specimens nitrided at 500℃ for 8 h for Fe and for 6 h for Al were measured using the glow discharge spectrometry and an X-ray diffractometer, respectively. XRD results indicate that the compound layer with hcp crystal structure (AIN) was formed on the top of Al substrate. During nitriding of Fe, the compound layer growth conforms to parabolic law and the surface nitrogen concentration change little with increasing the nitriding time. The surface nitrogen content of nitrided Al specimens is less than theoretical value 34.17 wt pct of AIN. The mathematical models of nitrogen concentration profiles in the surface layer of nitrided Al specimen have been established based on the research of the kinetics of pulse plasma nitriding of Fe and the nitrogen concentration profiles were also simulated. Results show that the predicted curves agree basically with the experimental data.展开更多
Due to the nature of ultra-short-acting opioid remifentanil of high time-varying,complex compartment model and low-accuracy of plasma concentration prediction,the traditional estimation method of population pharmacoki...Due to the nature of ultra-short-acting opioid remifentanil of high time-varying,complex compartment model and low-accuracy of plasma concentration prediction,the traditional estimation method of population pharmacokinetics parameters,nonlinear mixed effects model(NONMEM),has the abuses of tedious work and plenty of man-made jamming factors.The Elman feedback neural network was built.The relationships between the patients’plasma concentration of remifentanil and time,patient’age,gender,lean body mass,height,body surface area,sampling time,total dose,and injection rate through network training were obtained to predict the plasma concentration of remifentanil,and after that,it was compared with the results of NONMEM algorithm.In conclusion,the average error of Elman network is 6.34%,while that of NONMEM is 18.99%.The absolute average error of Elman network is 27.07%,while that of NONMEM is 38.09%.The experimental results indicate that Elman neural network could predict the plasma concentration of remifentanil rapidly and stably,with high accuracy and low error.For the characteristics of simple principle and fast computing speed,this method is suitable to data analysis of short-acting anesthesia drug population pharmacokinetic and pharmacodynamics.展开更多
High expression of fibrinogen and platelets are often observed in non–small cell lung cancer(NSCLC) patients with local regional or distant metastasis. However, the role of these factors remains unclear. The aims of ...High expression of fibrinogen and platelets are often observed in non–small cell lung cancer(NSCLC) patients with local regional or distant metastasis. However, the role of these factors remains unclear. The aims of this study were to evaluate the prognostic significance of plasma fibrinogen concentration and platelet count, as well as to determine the overall survival of NSCLC patients with brain metastases. A total of 275 NSCLC patients with brain metastasis were enrolled into this study. Univariate analysis showed that high plasma fibrinogen concentration was associated with age ≥ 65 years(P = 0.011), smoking status(P = 0.009), intracranial symptoms(P = 0.022), clinical T category(P = 0.010), clinical N category(P = 0.003), increased partial thromboplastin time(P < 0.001), and platelet count(P < 0.001). Patients with low plasma fibrinogen concentration demonstrated longer overall survival compared with those with high plasma fibrinogen concentration(median, 17.3 months versus 11.1 months; P ≤ 0.001). A similar result was observed for platelet counts(median, 16.3 months versus 11.4 months; P = 0.004). Multivariate analysis showed that both plasma fibrinogen concentration and platelet count were independent prognostic factors for NSCLC with brain metastases(R2 = 1.698, P < 0.001 and R2 = 1.699, P < 0.001, respectively). Our results suggest that high plasma fibrinogen concentration and platelet count indicate poor prognosis for NSCLC patients with brain metastases. Thus, these two biomarkers might be independent prognostic predictors for this subgroup of NSCLC patients.展开更多
In this study, a novel approach to measure the absolute cytoplasmic Caconcentration([Ca]cyt) using the Caindicator fluo-3 AM was established. The parameters associated with the probe fluo-3 AM were optimized to accura...In this study, a novel approach to measure the absolute cytoplasmic Caconcentration([Ca]cyt) using the Caindicator fluo-3 AM was established. The parameters associated with the probe fluo-3 AM were optimized to accurately determine fluorescence intensity from the Ca-bound probe. Using three optimized parameters(final concentration of 6 m M probe,incubation time of 135 min, loading probe before plasma treatment), the maximum fluorescence intensity(F?=?527.8 a.u.) and the minimum fluorescence intensity(F?=?63.8 a.u.) were obtained in a saturated Casolution or a solution of lacking Ca. Correspondingly, the maximum [Ca]cytinduced by cold plasma was 1232.5 n M. Therefore, the Caindicator fluo-3 AM was successfully applied to measure the absolute [Ca]cytin Saccharomyces cerevisiae stimulated by cold plasma at atmospheric air pressure.展开更多
Introduction: 5-Fluorouracil (5-FU) is the basis of most combination chemotherapies for gastrointestinal tumors. It is generally well tolerated, but side-effects might require dose-adjustment. As adverse events are no...Introduction: 5-Fluorouracil (5-FU) is the basis of most combination chemotherapies for gastrointestinal tumors. It is generally well tolerated, but side-effects might require dose-adjustment. As adverse events are not specific to the 5-FU component of the chemotherapy-combination, i.e. neutropenia, diarrhea or cardiotoxicity, the knowledge of 5-FU serum levels might help to attribute these side effects to the 5-FU compound. The optimal concentration-range (AUC, area under the curve) has been described to be within 20-25 mgh/l. The aim of this study was to analyse the intra- and interindividual variability of 5-FU AUC-levels in patients with 5-FU infusion therapy. Methods: 230 blood samples were obtained from 31 different gastrointestinal cancer patients (esophagus (8), stomach (10), ileum (1), colorectum (12)) treated with 5-FU-infusional regimes, based on a 24- or 48-hour AIO treatment-schedule. 5-FU plasma concentrations were measured using an immunolinked Elisa assay (Saladax 5-FU PCMTM). Intra- and interindividual differences were analysed before (0 h;n = 115), at 2 - 3 hours after the start of infusional 5-FU treatment (n = 19) (early sampling) and towards the end of the infusion (n = 96) (late sampling). Results: Early blood sampling resulted in low 5-FU plasma concentrations (541 ± 127 g/ml) due to saline prefilling (2 - 3 ml) of the Baxter pump. Blood sampling at the later time-point resulted in reproducible values (971 ± 81 ng/ml). 5-FU concentrations were dose-dependent with low intra- and interindividual variability. However, care has to be taken, as the results can be influenced by inaccurate blood sampling: too early or late sampling (when the folfusor-pump is empty), delayed centrifugation of the tube or hemolysis. Conclusions: With critical analysis of the measurements and correct performance of blood sampling, the measurement of 5-FU plasma concentrations with the immunoassay may in the future allow to optimize 5-FU dosing and to identify the cause of toxicity. Changes of 5-FU clearance in long-term therapy still have to be studied.展开更多
Antiretroviral therapy in HIV patients is known for its negative effect on the cardiovascular system. One of the major adverse events in patients on lopinavir is increasing lipids. Hyperlipidaemia together with chroni...Antiretroviral therapy in HIV patients is known for its negative effect on the cardiovascular system. One of the major adverse events in patients on lopinavir is increasing lipids. Hyperlipidaemia together with chronic inflammation by HIV-infection itself makes these patients prone for cardiovascular diseases.The purpose of this study (a sub study within the FREE-study) was to determine if higher plasma lopinavir (LPV) concentrations lead to increase of serum lipids. Plasma drug concentrations were analysed up to week 24 in a prospective cohort of HIV antiretroviral therapy naive patients who started on a regimen of zidovudine, lamivudine and ritonavir-boosted lopinavir (FREE study). Prospectively we measured plasma lopinavir concentrations from baseline to week 24 in 72 naive HIV-patients starting on lopinavir (59 males and 13 females). A total of 210 samples were analysed, with at least 2 samples in every patient. Mean LPV trough concentration was 4.3 mg/L (± 2.1). The median intra-subject variation in LPV level was 38% (range 4% - 111%). Serum lipids were not correlated to LPV plasma concentrations possibly due to the wide intra-individual variability in LPV trough levels. Monitoring of plasma lopinavir and subsequent dose adjustment of LPV will not be useful to prevent hyperlipidaemia in HIV-patients treated with lopinavir.展开更多
Purpose: Little research has been reported to date on the usefulness of olprinone in pediatric cardiac surgery, and no standard pediatric infusion protocol is currently established. Our study sought to confirm that th...Purpose: Little research has been reported to date on the usefulness of olprinone in pediatric cardiac surgery, and no standard pediatric infusion protocol is currently established. Our study sought to confirm that the regimen described herein rapidly achieves the requisite plasma olprinone concentrations. Methods: For the purposes of our study, we enrolled 13 patients: 7 biventricular repair candidates and 6 Fontan-type operation candidates. We administered a continuous infusion of olprinone to our study subjects at 0.3 μg/kg/min with no loading dose starting approximately 30 minutes (min) before weaning from cardiopulmonary bypass (CPB). We performed blood sampling at 15, 30, 45, 60, 90, and 120 min after the start of infusion and at the same elapsed intervals after separation from CPB. We measured plasma olprinone concentrations using ultra-fast liquid chromatography. Results: We observed effective plasma olpri-none concentrations (>20 ng/ml) at 30 min after weaning from CPB, or at 60 min after the start of infusion. Conclusion: We conclude that continuous olprinone infusion at 0.3 μg/kg/min without a loading dose initiated immediately after the release of aortic cross-clamping or immediately after the completion of all surgical procedures quickly and reliably achieves effective plasma concentrations.展开更多
Therapeutic plasma concentrations of EFV (efavirenz) are between 1,000 ng/mL and 4,000 ng/mL. Concentrations below 1000 ng/mL are associated with higher risk of treatment failure, and concentrations above 4,000 ng/m...Therapeutic plasma concentrations of EFV (efavirenz) are between 1,000 ng/mL and 4,000 ng/mL. Concentrations below 1000 ng/mL are associated with higher risk of treatment failure, and concentrations above 4,000 ng/mL are associated with toxicity. The aim of the study was to appreciate EFV plasmas concentrations profile and the association between plasma levels and various characteristics in Beninese patients treated by a 600 mg standard daily-dose. Blood samples were collected and EFV plasma levels were measured by liquid chromatography coupled with mass spectrometry detection in HIV-infected patients receiving EFV in combination with other antiretroviral drugs for at least 14 days. Adverse effects occurring during treatment were collected through a questionnaire. An over-exposure to EFV among Beninese HIV patients were observed, with 46.4% of patients presenting EFV concentration above 4,000 ng/mL, although adverse effects were tolerated indicating that antiretroviral treatment is safe. The measurement of plasma concentration at the steady-state could contribute to early detection of treatment failure and adapt treatment in subjects presenting serious adverse effects within context of therapeutic drug monitoring.展开更多
In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plas...In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge(DBD)for applications in plasma medicine.The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen.One of the emitted wavelengths is an important resonance wavelength of nitric oxide(λ = 226.2 nm).By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength,and measuring the change in intensity by the absorbing plasma,the concentration of nitric oxide inside the plasma can be calculated.The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm,so that a distance of about 10 cm to the respiratory tract is enough to conform to the VDI Guideline 2310.展开更多
The chickens used in this study were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasma very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. ...The chickens used in this study were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasma very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experimental results showed that there was a close relationship between plasma VLDL concentration and egg composition traits, and a positive phenotypic correlation trend was found between 29-week plasma VLDL concentration and 44-week yolk weight, and the genetic correlation coefficient was 0.234. Both the phenotypic and genetic correlations between 29-week plasma VLDL concentration and albumen weight were negative. Significant positive phenotypie correlations were, however, observed between yolk ratio, or the yolk/albumen ratio and 29-week plasma VLDL concentration, and their genetic correlation coefficients were 0.250 and 0.223, respectively.展开更多
The chickens studied were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasima very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experi...The chickens studied were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasima very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experiment results showed that the phenotypic correlations between 29-week or 50-week plasma VLDL concentration and egg production (EP) were positive in the early stage of laying period, but those in the latter stage were negative. Selection for low plasma VLDL concentration will decrease the EP in the early stage of laying period but increase the one in the latter stage. There was a significant negative phenotypic correlation between the age at first egg (AFE) and 18-week body weight (BW). The phenotypic correlation between 29-week plasma VLDL concentration and the AFE was negative. AFE was influenced by BW and body fatness as well. There was significant positive phenotypic correlation between plasima VLDL concentration and body weights (BWs) at the same stage in laying period and the phenotypic correlation was also positive between 29-week plasma VLDL concentration and the BW at middle stage of laying period, indicating that selection for low plasma VLDL concentration would reduce BWs at various stages to different degree.展开更多
Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparat...Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative(microfracture) or replacement(autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration,with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma(PRP) and bone marrow aspirate concentrate(BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.展开更多
To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride (Ber. H), chlorogenic acid (Chlo. A), and baicalin (Bai), their concentr...To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride (Ber. H), chlorogenic acid (Chlo. A), and baicalin (Bai), their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations (MICs). Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL^-1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL^-1, respectively. Their MICs to E. coli were, respectively, 1.0×10^3, 3.75 × 10^3, and 6.75 ×10^3μg mL^-1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.展开更多
The thermal pyrolysis of natural gas as a clean hydrogen production route is examined. The concept of a double-walled reactor tube is proposed and implemented. Preliminary experiments using an external plasma heating ...The thermal pyrolysis of natural gas as a clean hydrogen production route is examined. The concept of a double-walled reactor tube is proposed and implemented. Preliminary experiments using an external plasma heating source are carried out to validate this concept. The results point out the efficient CH4 dissociation above 1850 K (CH4 conversion over 90%) and the key influence of the gas residence time. Simulations are performed to predict the conversion rate of CH4 at the reactor outlet, and are consistent with experimental tendencies. A solar reactor prototype featuring four independent double-walled tubes is then developed. The heat in high temperature process required for the endothermic reaction of natural gas pyrolysis is supplied by concentrated solar energy. The tubes are heated uniformly by radiation using the blackbody effect of a cavity-receiver absorbing the concentrated solar irradiation through a quartz window. The gas composition at the reactor outlet, the chemical conversion of CH4, and the yield to H2 are determined with respect to reaction temperature, inlet gas flow-rates, and feed gas composition. The longer the gas residence time, the higher the CH4 conversion and H2 yield, whereas the lower the amount of acetylene. A CH4 conversion of 99% and H2 yield of about 85% are measured at 1880 K with 30% CH4 in the feed gas (6 L/min injected and residence time of 18 ms), A temperature increase from 1870 K to 1970 K does not improve the H2 yield.展开更多
基金Supported by Shanghai Civil Administration Bureau,No.8-2-50.
文摘BACKGROUND Prior studies have noted great variability in the plasma levels of risperidone(RIS).Plasma concentrations of RIS and its active moiety are highly variable and depend on absorption,metabolism,and other predictors of metabolic dysregulation;however,these factors are poorly understood and the association between metabolic change and change in psychopathology is uncertain.AIM To ascertain the characteristics of chronic schizophrenic patients treated with RIS,and to assess their relationship with plasma RIS levels.METHODS This was a descriptive cross-sectional study of 50 patients with a diagnosis of schizophrenic psychosis treated with RIS in a psychiatric service.The plasma concentrations of RIS and its metabolite 9-hydroxyrisperidone were determined by high performance liquid chromatography.The patients’demographic and clinical characteristics,and psychopathologies were assessed,and the associations between clinical variables and plasma levels of RIS were explored.RESULTS Male patients received higher doses of RIS than female ones,but plasma concentrations of RIS and risperidone+9-hydroxyrisperidone(active moiety)were higher in female patients.Age and the mean scores of the general psychopathology subscale of the Positive and Negative Syndrome Scale(PANSS)were significantly positively correlated with plasma concentrations of risperidone+9-hydroxyrisperidone adjusted for weight and dose in all 50 subjects.In male subjects,we found a statistically significant positive correlation between the concentrations of risperidone+9-hydroxyrisperidone in plasma/(dose×kg)and age,mean PANSS negative subscale scores,mean PANSS general psychopathology subscale scores,and mean PANSS total scores.CONCLUSION Long-term use of RIS should be closely monitored in older patients and females to minimize the risk of high concentrations which could induce side effects.
基金China Scholarship Council for the award of fellowship and funding(No.202006370022).
文摘In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate.
文摘A method for determination of lycopene concentration in dog plasma wasestablished. Methods RP-HPLC was used; the mobile phase consisted of methanol-acetonitrile-methylenechloride (40:30:30, V/V) , the wavelength of detection was 472 nm, the column temperature wasambient temperature, and the flow rate was 1.0 mL·min^(-1). Results The standard curve was linearin the range from 0.012 4 to 0.496 μg·mL^(-1) with r=0.9992. The average extraction recovery was97.6% +-4.2%. The intra-day and inter-day RSD were 1.52% -4.95% and 2.31% -7.38%, respectively.Conclusion This method is sensitive, rapid, reproducible, and of good selectivity for the analysisof lycopene in dog plasma.
基金supported by NOVUS Intl.(MO.USA)The authors are grateful to the company for supplying fund and DL-SeMet samples
文摘Background: This study was designed to evaluate the efficacy of DL-selenomethionine (DL^SeMet) supplementation on growth performance, antioxidant status, plasma selenium (Se) concentration, and immune function of weaning pigs. 216 weaning pigs were randomly allocated to 6 treatments with 6 replicates each according to a complete randomized block design. Each replicate had six pigs. Diet of group one was corn-soybean basal diet without any additional Se supplement. Group 2 was supplemented with 0.3 mg/kg of Se from sodium selenite. Groups 3-6 were supplemented with 0.1, 0.3, 0.5, and 0.7 mg/kg of Se from DL-SeMet, respectively. The trial lasted for 42 days. Results: Pigs supplemented with 0.3 and 0.7 mg/kg DL-SeMet obtained better feed gain ratio (P 〈 0.05). The best antioxidant ability (serum, liver, and muscle) was shown in 0.1-0.3 mg/kg DL-SeMet groups (P〈 0.05). The plasma Se concentration increased as the dietary DL-SeMet level elevated. The immunity among groups was not affected. Conclusions: DL-SeMet supplementation in the diet significantly improved the growth performance, antioxidant ability and plasma Se content of weaning pigs. DL-SeMet can replace sodium selenite in the diet of weaning pigs.
基金the Medical Science & Technology Research fund of Health Bureau of Chongqing City,China [No.2004(53)04-2-154]the Nature Science Research fund of Chongqing Science & Technology Com-mission of Chongqing City,China (No.CSTC,2007BB5276).
文摘Objectives To study the relationship between plasma hemoglobin concentration and estimated glomerular filtration rate (eGFR) in elderly patients with ischemic cardiomyopathy (ICM).Methods Clinical data of patients with coronary heart disease who were discharged from The First Affiliated Hospital,Chongqing Medical University between 2005 and 2007 were analyzed retrospectively. Echocardiography results,plasma hemoglobin and creatinine concentration were abstracted from the medical records.The study included 235 Chinese Hart patients with age 60 years and older with angiography confirmed coronary heart disease,silent myocardial ischemia or angina pectoris,of whom 154 had ICM defined as left ventricular end-diastolic diameter (LVDd),male≥56 mm,female≥51 mm (63. 51±7.70 mm) measured by M-mode echocardiography.The differences in plasma hemoglobin concentration were analyzed retrospec- tively between patients with and without ICM,and between patients with an eGFR【60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> and those with an eGFR≥60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup>.Results There were no significant differences in plasma hemoglobin concentration and eGFR between ICM and non-ICM group (118.49±20.52 g·L<sup>-1</sup> vs.115.80±23.32 g·L<sup>-1</sup> and 75.13±24.21 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> vs.79.09±28.41 ml·min<sup>- 1</sup>·1.73m<sup>-2</sup>,respectively,both P】0.05).However,in both ICM and non-ICM groups,plasma hemoglobin concentration was lower in those with an eGFR【60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> compared with compared with those with an eGFR≥60 ml·min<sup>-1</sup>·1.73m<sup>-2</sup> group (112. 29±18.61 g·L<sup>-1</sup> vs.119.92±20.74L<sup>-1</sup>,P【0.05);plasma hemoglobin concentration was related positively to eGFR.Conclusions There were no significant changes in plasma hemoglobin concentration and eGFR;however,plasma hemoglobin concentration was related to eGFR significantly positively in elderly patients with ICM due to coronary heart
文摘Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide.The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina(APS)coatings on AZ31B magnesium alloy was investigated using immersion corrosion test in NaCl solutions of different chloride ion concentrations viz.,0.01 M,0.2 M,0.6 M and 1 M.The corroded surface was characterized by an optical microscope and X-ray diffraction.The results showed that the corrosion deterioration of uncoated and coated samples were significantly influenced by chloride ion concentration.The uncoated magnesium and alumina coatings were found to offer a superior corrosion resistance in lower chloride ion concentration NaCl solutions(0.01 M and 0.2 M NaCl).On the other hand the coatings and Mg alloy substrate were found to be highly susceptible to localized damage,and could not provide an effective corrosion protection in solutions containing higher chloride concentrations(0.6 M and 1 M).It was found that the corrosion resistance of the ceramic coatings and base metal gets deteriorated with the increase in the chloride concentrations.
基金The authors acknowledge financial support from the National Natural Science Foundation of China under grant No.50071020 for this work.
文摘Two materials, pure Fe and pure Al, were nitrided in a pulse plasma nitriding facility. The nitrogen profiles in surface layers and the surface phase structures of specimens nitrided at 500℃ for 8 h for Fe and for 6 h for Al were measured using the glow discharge spectrometry and an X-ray diffractometer, respectively. XRD results indicate that the compound layer with hcp crystal structure (AIN) was formed on the top of Al substrate. During nitriding of Fe, the compound layer growth conforms to parabolic law and the surface nitrogen concentration change little with increasing the nitriding time. The surface nitrogen content of nitrided Al specimens is less than theoretical value 34.17 wt pct of AIN. The mathematical models of nitrogen concentration profiles in the surface layer of nitrided Al specimen have been established based on the research of the kinetics of pulse plasma nitriding of Fe and the nitrogen concentration profiles were also simulated. Results show that the predicted curves agree basically with the experimental data.
基金Project(31200748)supported by the National Natural Science Foundation of China
文摘Due to the nature of ultra-short-acting opioid remifentanil of high time-varying,complex compartment model and low-accuracy of plasma concentration prediction,the traditional estimation method of population pharmacokinetics parameters,nonlinear mixed effects model(NONMEM),has the abuses of tedious work and plenty of man-made jamming factors.The Elman feedback neural network was built.The relationships between the patients’plasma concentration of remifentanil and time,patient’age,gender,lean body mass,height,body surface area,sampling time,total dose,and injection rate through network training were obtained to predict the plasma concentration of remifentanil,and after that,it was compared with the results of NONMEM algorithm.In conclusion,the average error of Elman network is 6.34%,while that of NONMEM is 18.99%.The absolute average error of Elman network is 27.07%,while that of NONMEM is 38.09%.The experimental results indicate that Elman neural network could predict the plasma concentration of remifentanil rapidly and stably,with high accuracy and low error.For the characteristics of simple principle and fast computing speed,this method is suitable to data analysis of short-acting anesthesia drug population pharmacokinetic and pharmacodynamics.
基金supported by grants from Ministry of Science and Technology Projects of China(No.2012AA021502)Provincial Science and Technology Projects of Guangdong(No.2012B031800295)
文摘High expression of fibrinogen and platelets are often observed in non–small cell lung cancer(NSCLC) patients with local regional or distant metastasis. However, the role of these factors remains unclear. The aims of this study were to evaluate the prognostic significance of plasma fibrinogen concentration and platelet count, as well as to determine the overall survival of NSCLC patients with brain metastases. A total of 275 NSCLC patients with brain metastasis were enrolled into this study. Univariate analysis showed that high plasma fibrinogen concentration was associated with age ≥ 65 years(P = 0.011), smoking status(P = 0.009), intracranial symptoms(P = 0.022), clinical T category(P = 0.010), clinical N category(P = 0.003), increased partial thromboplastin time(P < 0.001), and platelet count(P < 0.001). Patients with low plasma fibrinogen concentration demonstrated longer overall survival compared with those with high plasma fibrinogen concentration(median, 17.3 months versus 11.1 months; P ≤ 0.001). A similar result was observed for platelet counts(median, 16.3 months versus 11.4 months; P = 0.004). Multivariate analysis showed that both plasma fibrinogen concentration and platelet count were independent prognostic factors for NSCLC with brain metastases(R2 = 1.698, P < 0.001 and R2 = 1.699, P < 0.001, respectively). Our results suggest that high plasma fibrinogen concentration and platelet count indicate poor prognosis for NSCLC patients with brain metastases. Thus, these two biomarkers might be independent prognostic predictors for this subgroup of NSCLC patients.
基金supported by National Natural Science Foundation of China (Grant Nos. 21246012, 21306015 and 21476032)
文摘In this study, a novel approach to measure the absolute cytoplasmic Caconcentration([Ca]cyt) using the Caindicator fluo-3 AM was established. The parameters associated with the probe fluo-3 AM were optimized to accurately determine fluorescence intensity from the Ca-bound probe. Using three optimized parameters(final concentration of 6 m M probe,incubation time of 135 min, loading probe before plasma treatment), the maximum fluorescence intensity(F?=?527.8 a.u.) and the minimum fluorescence intensity(F?=?63.8 a.u.) were obtained in a saturated Casolution or a solution of lacking Ca. Correspondingly, the maximum [Ca]cytinduced by cold plasma was 1232.5 n M. Therefore, the Caindicator fluo-3 AM was successfully applied to measure the absolute [Ca]cytin Saccharomyces cerevisiae stimulated by cold plasma at atmospheric air pressure.
文摘Introduction: 5-Fluorouracil (5-FU) is the basis of most combination chemotherapies for gastrointestinal tumors. It is generally well tolerated, but side-effects might require dose-adjustment. As adverse events are not specific to the 5-FU component of the chemotherapy-combination, i.e. neutropenia, diarrhea or cardiotoxicity, the knowledge of 5-FU serum levels might help to attribute these side effects to the 5-FU compound. The optimal concentration-range (AUC, area under the curve) has been described to be within 20-25 mgh/l. The aim of this study was to analyse the intra- and interindividual variability of 5-FU AUC-levels in patients with 5-FU infusion therapy. Methods: 230 blood samples were obtained from 31 different gastrointestinal cancer patients (esophagus (8), stomach (10), ileum (1), colorectum (12)) treated with 5-FU-infusional regimes, based on a 24- or 48-hour AIO treatment-schedule. 5-FU plasma concentrations were measured using an immunolinked Elisa assay (Saladax 5-FU PCMTM). Intra- and interindividual differences were analysed before (0 h;n = 115), at 2 - 3 hours after the start of infusional 5-FU treatment (n = 19) (early sampling) and towards the end of the infusion (n = 96) (late sampling). Results: Early blood sampling resulted in low 5-FU plasma concentrations (541 ± 127 g/ml) due to saline prefilling (2 - 3 ml) of the Baxter pump. Blood sampling at the later time-point resulted in reproducible values (971 ± 81 ng/ml). 5-FU concentrations were dose-dependent with low intra- and interindividual variability. However, care has to be taken, as the results can be influenced by inaccurate blood sampling: too early or late sampling (when the folfusor-pump is empty), delayed centrifugation of the tube or hemolysis. Conclusions: With critical analysis of the measurements and correct performance of blood sampling, the measurement of 5-FU plasma concentrations with the immunoassay may in the future allow to optimize 5-FU dosing and to identify the cause of toxicity. Changes of 5-FU clearance in long-term therapy still have to be studied.
文摘Antiretroviral therapy in HIV patients is known for its negative effect on the cardiovascular system. One of the major adverse events in patients on lopinavir is increasing lipids. Hyperlipidaemia together with chronic inflammation by HIV-infection itself makes these patients prone for cardiovascular diseases.The purpose of this study (a sub study within the FREE-study) was to determine if higher plasma lopinavir (LPV) concentrations lead to increase of serum lipids. Plasma drug concentrations were analysed up to week 24 in a prospective cohort of HIV antiretroviral therapy naive patients who started on a regimen of zidovudine, lamivudine and ritonavir-boosted lopinavir (FREE study). Prospectively we measured plasma lopinavir concentrations from baseline to week 24 in 72 naive HIV-patients starting on lopinavir (59 males and 13 females). A total of 210 samples were analysed, with at least 2 samples in every patient. Mean LPV trough concentration was 4.3 mg/L (± 2.1). The median intra-subject variation in LPV level was 38% (range 4% - 111%). Serum lipids were not correlated to LPV plasma concentrations possibly due to the wide intra-individual variability in LPV trough levels. Monitoring of plasma lopinavir and subsequent dose adjustment of LPV will not be useful to prevent hyperlipidaemia in HIV-patients treated with lopinavir.
文摘Purpose: Little research has been reported to date on the usefulness of olprinone in pediatric cardiac surgery, and no standard pediatric infusion protocol is currently established. Our study sought to confirm that the regimen described herein rapidly achieves the requisite plasma olprinone concentrations. Methods: For the purposes of our study, we enrolled 13 patients: 7 biventricular repair candidates and 6 Fontan-type operation candidates. We administered a continuous infusion of olprinone to our study subjects at 0.3 μg/kg/min with no loading dose starting approximately 30 minutes (min) before weaning from cardiopulmonary bypass (CPB). We performed blood sampling at 15, 30, 45, 60, 90, and 120 min after the start of infusion and at the same elapsed intervals after separation from CPB. We measured plasma olprinone concentrations using ultra-fast liquid chromatography. Results: We observed effective plasma olpri-none concentrations (>20 ng/ml) at 30 min after weaning from CPB, or at 60 min after the start of infusion. Conclusion: We conclude that continuous olprinone infusion at 0.3 μg/kg/min without a loading dose initiated immediately after the release of aortic cross-clamping or immediately after the completion of all surgical procedures quickly and reliably achieves effective plasma concentrations.
文摘Therapeutic plasma concentrations of EFV (efavirenz) are between 1,000 ng/mL and 4,000 ng/mL. Concentrations below 1000 ng/mL are associated with higher risk of treatment failure, and concentrations above 4,000 ng/mL are associated with toxicity. The aim of the study was to appreciate EFV plasmas concentrations profile and the association between plasma levels and various characteristics in Beninese patients treated by a 600 mg standard daily-dose. Blood samples were collected and EFV plasma levels were measured by liquid chromatography coupled with mass spectrometry detection in HIV-infected patients receiving EFV in combination with other antiretroviral drugs for at least 14 days. Adverse effects occurring during treatment were collected through a questionnaire. An over-exposure to EFV among Beninese HIV patients were observed, with 46.4% of patients presenting EFV concentration above 4,000 ng/mL, although adverse effects were tolerated indicating that antiretroviral treatment is safe. The measurement of plasma concentration at the steady-state could contribute to early detection of treatment failure and adapt treatment in subjects presenting serious adverse effects within context of therapeutic drug monitoring.
文摘In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge(DBD)for applications in plasma medicine.The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen.One of the emitted wavelengths is an important resonance wavelength of nitric oxide(λ = 226.2 nm).By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength,and measuring the change in intensity by the absorbing plasma,the concentration of nitric oxide inside the plasma can be calculated.The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm,so that a distance of about 10 cm to the respiratory tract is enough to conform to the VDI Guideline 2310.
文摘The chickens used in this study were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasma very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experimental results showed that there was a close relationship between plasma VLDL concentration and egg composition traits, and a positive phenotypic correlation trend was found between 29-week plasma VLDL concentration and 44-week yolk weight, and the genetic correlation coefficient was 0.234. Both the phenotypic and genetic correlations between 29-week plasma VLDL concentration and albumen weight were negative. Significant positive phenotypie correlations were, however, observed between yolk ratio, or the yolk/albumen ratio and 29-week plasma VLDL concentration, and their genetic correlation coefficients were 0.250 and 0.223, respectively.
文摘The chickens studied were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasima very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experiment results showed that the phenotypic correlations between 29-week or 50-week plasma VLDL concentration and egg production (EP) were positive in the early stage of laying period, but those in the latter stage were negative. Selection for low plasma VLDL concentration will decrease the EP in the early stage of laying period but increase the one in the latter stage. There was a significant negative phenotypic correlation between the age at first egg (AFE) and 18-week body weight (BW). The phenotypic correlation between 29-week plasma VLDL concentration and the AFE was negative. AFE was influenced by BW and body fatness as well. There was significant positive phenotypic correlation between plasima VLDL concentration and body weights (BWs) at the same stage in laying period and the phenotypic correlation was also positive between 29-week plasma VLDL concentration and the BW at middle stage of laying period, indicating that selection for low plasma VLDL concentration would reduce BWs at various stages to different degree.
文摘Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative(microfracture) or replacement(autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration,with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma(PRP) and bone marrow aspirate concentrate(BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.
基金supported by a grant from Beijing Natural Science Foundation, China (6021001)agrant from Learning Innovative Group Programs of Beijing Education Committee, China (5090245)
文摘To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride (Ber. H), chlorogenic acid (Chlo. A), and baicalin (Bai), their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations (MICs). Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL^-1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL^-1, respectively. Their MICs to E. coli were, respectively, 1.0×10^3, 3.75 × 10^3, and 6.75 ×10^3μg mL^-1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.
基金European FP6 research project SOLHYCARB (Contract SES-CT-2006-19770)
文摘The thermal pyrolysis of natural gas as a clean hydrogen production route is examined. The concept of a double-walled reactor tube is proposed and implemented. Preliminary experiments using an external plasma heating source are carried out to validate this concept. The results point out the efficient CH4 dissociation above 1850 K (CH4 conversion over 90%) and the key influence of the gas residence time. Simulations are performed to predict the conversion rate of CH4 at the reactor outlet, and are consistent with experimental tendencies. A solar reactor prototype featuring four independent double-walled tubes is then developed. The heat in high temperature process required for the endothermic reaction of natural gas pyrolysis is supplied by concentrated solar energy. The tubes are heated uniformly by radiation using the blackbody effect of a cavity-receiver absorbing the concentrated solar irradiation through a quartz window. The gas composition at the reactor outlet, the chemical conversion of CH4, and the yield to H2 are determined with respect to reaction temperature, inlet gas flow-rates, and feed gas composition. The longer the gas residence time, the higher the CH4 conversion and H2 yield, whereas the lower the amount of acetylene. A CH4 conversion of 99% and H2 yield of about 85% are measured at 1880 K with 30% CH4 in the feed gas (6 L/min injected and residence time of 18 ms), A temperature increase from 1870 K to 1970 K does not improve the H2 yield.