Objective:To establish a rapid and precise dose measurement method with EBT4 film and ensure its measurement accuracy to be within the required range through strict operational procedures for the purpose of addressing the two essential issues of poor measurement accuracy and timeliness of EBT film under FLASH conditions.Methods:After storing under different humidity conditions for a certain period of time, the film was exposed to radiation for analyzing the influence of air humidity on the intrinsic performance of EBT film. By means of repeated scanning operations and the film angle rotation, the influences of repeated scanning and film placement angle were analuzed. Parabolic correction method was used to reduce the spatial position influence during the scanning process. By analying the relationship between net optical density (netOD) and absorbed dose through the comparison of three fitting method, the optimal fitting curve was selected. After irradiation of the same batch of films for 5 min and 24 h, the film doses were calibrated and then compared with ionization chamber-measured result. The rapid and precise film dosimetry method was used to measure both the percentage depth dose from X-rays at ultra-high dose rate and the dose distribution at a depth of 2 cm in water.Results:Air humidity had the greatest influence on the intrinsic performance of EBT film (approximately 20%). The average deviation of repeated scans is within 0.5%. The angle at which the film is placed significantly affected the readouts of the film with the maximum influence approximately 70%. The net optical density combined with polynomial fitting can control the fitting residuals of 1-16 Gy within 3%. The change rate of light channels at 5 min already mostly met the requirements of the rapid mode (< 0.5%). Compared with the measurement result obtained using the reference ionization chamber, the deviations of the 5 min or 24 h dose calibration curves were all within 2%.Conclusions:The EBT4 film can be employed as a precise dosimeter to quickly measure the FLASH radiation dose. Rapid and precise FLASH dose measurements can meet the stringent requirements of both preclinical and clinical FLASH research.

Objective:To establish a rapid and precise dose measurement method with EBT4 film and ensure its measurement accuracy to be within the required range through strict operational procedures for the purpose of addressing the two essential issues of poor measurement accuracy and timeliness of EBT film under FLASH conditions.Methods:After storing under different humidity conditions for a certain period of time, the film was exposed to radiation for analyzing the influence of air humidity on the intrinsic performance of EBT film. By means of repeated scanning operations and the film angle rotation, the influences of repeated scanning and film placement angle were analuzed. Parabolic correction method was used to reduce the spatial position influence during the scanning process. By analying the relationship between net optical density (netOD) and absorbed dose through the comparison of three fitting method, the optimal fitting curve was selected. After irradiation of the same batch of films for 5 min and 24 h, the film doses were calibrated and then compared with ionization chamber-measured result. The rapid and precise film dosimetry method was used to measure both the percentage depth dose from X-rays at ultra-high dose rate and the dose distribution at a depth of 2 cm in water.Results:Air humidity had the greatest influence on the intrinsic performance of EBT film (approximately 20%). The average deviation of repeated scans is within 0.5%. The angle at which the film is placed significantly affected the readouts of the film with the maximum influence approximately 70%. The net optical density combined with polynomial fitting can control the fitting residuals of 1-16 Gy within 3%. The change rate of light channels at 5 min already mostly met the requirements of the rapid mode (< 0.5%). Compared with the measurement result obtained using the reference ionization chamber, the deviations of the 5 min or 24 h dose calibration curves were all within 2%.Conclusions:The EBT4 film can be employed as a precise dosimeter to quickly measure the FLASH radiation dose. Rapid and precise FLASH dose measurements can meet the stringent requirements of both preclinical and clinical FLASH research.

OBJECTIVES: The plateau environment is characterized by low oxygen partial pressure, leading to the reduction of oxygen carrying capacity in alveoli and the reduction of available oxygen in tissues, and thus causing tissue damage. Cilostazol is a phosphodiesterase III inhibitor that has been reported to increase the oxygen release of hemoglobin (Hb) in tissues. This study aims to explore the anti-hypoxic activity of cilostazol and its anti-hypoxic effect. METHODS: A total of 40 male BALB/C mice were randomly divided into a low-dose cilostazol (6.5 mg/kg) group, a medium-dose (13 mg/kg) group, a high-dose (26 mg/kg) group, and a control group. The atmospheric airtight hypoxia experiment was used to investigate the anti-hypoxic activity of cilostazol and to screen the optimal dosage. Twenty-four male Wistar rats were randomly divided into a normoxia control group, a hypoxia model group, an acetazolamide (22.33 mg/kg) group, and a cilostazol (9 mg/kg) group. After 3 days of hypoxia in the 4 010 m high altitude, blood from the abdominal aorta was collected to determine blood gas indicators, the levels of IL-6 and TNF-α in plasma were determined by enzyme-linked immunosorbent assay, and the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutataione (GSH) were measured. The degree of pathological damage for rat tissues was observed with HE staining. RESULTS: Compared with the control group, the survival time of mice in the low, medium, and high dose group of cilostazol was significantly prolonged, and the survival time of mice in the medium dose group was the longest, with an extension rate at 29.34%, so the medium dose was the best dose. Compared with the hypoxia model group, the P50 (oxygen partial pressure at Hb oxygen saturation of 50%) value of rats in the cilostazol group was significantly increased by 1.03%; Hb and Hct were significantly reduced by 8.46% and 8.43%, and the levels of IL-6 and TNF-α in plasma were reduced by 50.65% and 30.77%. The MDA contents in heart, brain, lung, liver, and kidney tissues were reduced by 37.12%, 29.55%, 25.00%, 39.34%, and 21.47%, respectively. The SOD activities were increased by 94.93%, 9.14%, 9.42%, 13.29%, and 20.80%, respectively. The GSH contents were increased by 95.24%, 28.62%, 28.57%, 20.80%, and 44.00%, respectively. The results of HE staining showed that compared with the hypoxia model group, cilostazol significantly improved the damage of heart, lung, and kidney tissues in rats after hypoxia. CONCLUSIONS Cilostazol can significantly improve the oxidative stress and inflammatory reaction caused by rapid altitude hypoxia, and it has a significant protective effect on tissue damage caused by hypoxia, suggesting that it has obvious anti-hypoxic activity.
Altitude Sickness ; Animals ; Cilostazol/therapeutic use* ; Hypoxia/drug therapy* ; Interleukin-6/pharmacology* ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; Oxygen ; Rats ; Rats, Wistar ; Superoxide Dismutase/metabolism* ; Tumor Necrosis Factor-alpha/pharmacology*

Low oxygen partial pressure is the main cause of acute mountain sickness.Hemoglobin plays a crucial physiological role in the binding, utilization, transportation and release of oxygen in the body. To increase the capacity of oxygen binding of hemoglobin or the capacity of oxygen supply in tissues can help alleviate altitude sickness. However, increasing hemoglobin content has certain limitations. Using techniques from molecular biology, researchers are looking for endogenous or exogenous substances that can regulate the conformation of hemoglobin to increase oxygen uptake in the alveoli, or the availability of alveolar oxygen in the tissues. At present, the research on allosteric modulators to improve the affinity of hemoglobin has made some progress, and research on applying this mechanism to plateau hypoxia is also underway. This article reviews the relationship between hemoglobin and hypoxia, the structure of hemoglobin and the role of various allosteric modulators in hypoxia, which would provide information for finding new substances regulating the conformation of hemoglobin.

An ultra performance convergence chromatographic ( UPC2 ) method was established for the attribution analysis of the main peaks as well as the quantitative determination of echinacoside andβ-ecdyserone in Bushen Jiannao Grains. The samples were extracted with ethanol and separated on Waters ACQUITY UPC2TM BEH column (100 mm × 3. 00 mm, 1. 7 μm), with a gradient supercritical CO2-0. 05%phosphoric acid-methanol solvent system at 40 ℃. The flow rate was 0. 8 mL/min, the detection wavelength was set at 248 nm and the injection volume was 1 μL. Results showed that all the main peaks in the fingerprint were clearly attributed. The peak named 12 wasβ-ecdyserone with the content of 380μg/g and the peak named 15 was echinacoside with the content of 9. 562 mg/g. The method was simple, eco-friendly, accurate and reliable compared with HPLC and UPLC.

SHG was sulfated by chlorosulfonic acid-pyridine method, and six samples which we got were prepared in different reaction conditions. There is a characteristic absorption peak near 260 nm in UV spectra and there are two characteristic absorption peaks near 1240 cm(-1) and 810 cm(-1) in the FT-IR. Degree of sulfation (DS) was calculated by elemental analysis and turbidimetry. Under the same conditions the absorption peaks become strong with the DS increase. The anticoagulant activity of SHG and sulfated modification samples was evaluated by the classic coagulant assays of prothrombin time (PT), activated partial thrombin time (APTT) live enzymes, and plasma thrombin time (TT). Results show that sulfated SHG has a good anticoagulant activity in vitro, and DS increased activity within a certain range.

OBJECTIVETo determine such molecular characteristic parameters as absolute molecular weight, molecular weight distribution, root-mean-square turning radius (Rg) and polydispersity index (Mw/Mn) of four components contained in Hedysari Radix polysaccharide 3 (HPS-3) and map weight-average molecular weight (Mw) with root-mean-square turning radius (Rg), in order to calculate conformations of the four components at solution state.

METHODThe gel permeation chromatography-multi angle laser light scatting (GPC-MALLS) was adopted, with 0.1 mol x L(-1) NaNO3 contained 0.02% NaN3 as the mobilephase, Ultrahydrogel 1000 connected in series with Ultrahydrogel500.

RESULTAmong the four components of HPS-3, HPS-3-C showed the highest weight average molecular weight of 1.986 x 10(5) g x mol(-1), followed by HPS-3-B 1.113 x 10(5) g x mol(-1) and HPS-3-D 8.457 x 10(4) g x mol(-1) HPS-3-A showed the lowest weight average molecular weight of 1. 223 x 10(4) g x mol(-1) but the highest square radius of gyration, that is 55.5 nm. HPS-3-D had the widest range of molecular weight distribution in four components, with the polydispersity index (Mw/Mn) of 2.543. In the mobile phase, HPS-3-A was globular structure, HPS-3-C was random coil, HPS-3-B and HPS-3-D were both highly branched structure.

CONCLUSIONThe results provided necessary basis for further studies on molecular characteristics of the four components contained in HPS-3 and their relationship with bioactivity.

Chromatography, Gel ; Drugs, Chinese Herbal ; chemistry ; Lasers ; Light ; Polysaccharides ; chemistry ; Scattering, Radiation

OBJECTIVETo determine bergapten's concentration in plasma and observe its pharmacokinetics in rats using a combined LC-MS/MS analytical method.

METHODBlood samples were separated on a Hypersil ODS column (4.6 mm x 250 mm, 5 mm) at a temperature of 30 degrees C, and mobile phase consisted of water and methanol (22.5: 77.5) at a flow rate of 0.8 mL x min(-1).

RESULTThe methodological study showed a good linear relationship of 8.12-162.4 g x L(-1) (r = 0.9999). The inner and inter-days relative standard deviations were both less than 10% , indicating legitimate precise and accuracy to the requirement of biological sample analysis.

CONCLUSIONThe method is suitable for in vivo quantitative analysis for bergapten due to its accuracy, sensitivity and specificity. The pharmacokinetic process in rats forms a two-compartment model with first-order absorption.

Animals ; Chromatography, Liquid ; Male ; Methoxsalen ; analogs & derivatives ; blood ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Reference Values ; Reproducibility of Results ; Sensitivity and Specificity ; Tandem Mass Spectrometry ; Time Factors

A simple and accurate high-performance liquid chromatography（HPLC）coupled with diode array detector（DAD）and evaporative light scattering detector（ELSD）was established for the determination of six bioactive compounds in Zhenqi Fuzheng preparation（ZFP）.The monitoring wavelengths were 254,275 and 328 nm.Under the optimum conditions,good separation was achieved,and the assay was fully validated in respect of precision,repeatability and accuracy.The proposed method was successfully applied to quantify the six ingredients in 31 batches of ZFP samples and evaluate the variation by hierarchical cluster analysis（HCA）,which demonstrated significant variations on the content of these compounds in the samples from different manufacturers with different preparation procedures.The developed HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of this preparation.

An approach was proposed to evaluate preparation technology by means of fingerprint-peak matching technology of high performance liquid chromatography with diode array detector (HPLC-DAD).Similarity and hierarchical clustering analysis (HCA) were applied to identify the 15 batches of Xiaochaihu granules from different manufacturers and our laboratory,and peak pattern matching between the composite formulae and Radix Bupleuri Chinensis,which was one of the main ingredients of Xiaochaihu granules,was utilized to evaluate the preparation technology of Xiaochaihu granules via the indexes of the relative deviation of retention time (RT) and UV spectrum feature similarity of their corresponding peaks.Eleven matching peaks were found between Xiaochalhu granules and Radix Bupleuri Chinensis.However,the saikosaponin A and saikosaponin D,which are the important active components in Radix Bupleuri Chinensis,were not found in Xiaochaihu granules from any manufacturers.The peak areas of 11 characteristic peaks of Xiaochaihu granules samples formed a matrix of 11 × 15.The result of HCA showed that Xiaochaihu granules samples were divided into four kinds of category.Xiaochaihu granules samples from the same manufacturer were basically clustered of the same category.The results suggested that the saikosaponin A and saikosaponin D are prone to structural transformation under the condition of decoction and in the presence of the organic acidic components.These active components,existing in raw herb,might transform to a series of non-active secondary saikosaponin due to unfavourable preparation technology.So the conventional decoction-based preparation technology of Xiaochaihu granules might greatly affect its quality and therapeutic effectiveness. This study demonstrates that fingerprint-peak matching technology can not only be used for quality control of this composite formulae,but also provide some guidance for preparation technology of Xiaochaihu granules.