Spatial and temporal trends and drivers of fractional vegetation cover in Heilongjiang Province, China during 1990-2020.

Fractional vegetation cover (FVC) is a quantitative indicator for vegetation growth conditions and ecosystem change. Clarifying the spatial and temporal trends and driving factors of FVC is an important research content of global and regional ecological environment. Based on Google Earth Engine (GEE) cloud computing platform, we estimated FVC in Heilongjiang Province from 1990 to 2020 using the pixel dichotomous model. We analyzed the temporal and spatial trends and drivers of FVC using Mann-Kendall mutation test, Sen's slope analysis with Mann-Kendall significance test, correlation analysis, and structural equation model. The results showed that the estimated FVC based on the pixel dichotomous model had high accuracy (R2>0.7, root mean square error <0.1, relative root mean square error <14%). From 1990 to 2020, the annual average FVC in Heilongjiang was 0.79, with a fluctuating upward trend (0.72-0.85) and an average annual growth rate of 0.4%. The annual average FVC at the municipal administrative districts level also showed different levels of increase of FVC. The area with extremely high FVC dominated the Heilongjiang Province with a gradual increase proportion. The area with increasing trend of FVC accounted for 67.4% of the total area, whereas the area with decreasing trend only accounted for 26.2%, and the rest remained unchanged. The correlation of human activity factor on annual average FVC was higher than that of growing season monthly average meteorological factor. The human activity factor was the main driver for FVC change in Heilongjiang Province, followed by land use type. The total effect of monthly average meteorological factor during the growing season on FVC change was negative. The results would serve as technical support for long-term FVC monitoring and driving force analysis in Heilongjiang Province, and provide a reference for ecological environment restoration and protection, as well as the formulation of related land use policy.

A study on the enrichment mechanism of three nitrophenol isomers in environmental water samples by charge transfer supramolecular-mediated hollow fiber liquid-phase microextraction.

To explore the mechanism of extraction and enrichment of three nitrophenol isomers by charge-transfer supramolecular synergistic three-phase microextraction system, a charge transfer supramolecular-mediated hollow fiber liquid-phase microextraction (CTSM-HF-LPME) combined with high-performance liquid chromatography-ultraviolet detector (HPLC-UV) method was established for the determination of real environmental water samples. In this study, the three nitrophenols (NPs) formed charge-transfer supramolecules with electron-rich hollow fibers, which promoted the transport of NPs in the three-phase extraction system and greatly increased the EFs of NPs. The relationships between the EFs of NPs and their solubility, pKa, apparent partition coefficient, equilibrium constant, and structural property parameters were investigated and discussed. At the same time, most of factors affecting the EFs of NPs were investigated and optimized, such as the type of extraction solvent, pH value of sample phase and acceptor phase, extraction time, and stirring speed. Under optimal conditions, the EFs of o-nitrophenol, m-nitrophenol, and p-nitrophenol were 163, 145, and 87, respectively. With good linearity in the range of 5 × 10-7 ~ 1 µg/mL, and the limit of detection of 0.1 pg/mL, the relative standard deviations of the method precision were lower than 7.4%, and the average recoveries were between 98.6 and 106.4%. This method had good selectivity and sensitivity, satisfactory precision, and accuracy and had been successfully applied to the trace detection of real water samples.

Solvent terminated natural deep eutectic solvent microextraction for concentration of curcuminoids in Curcumae Longae Rhizoma and turmeric tea.

A novel solvent terminated microextraction method based on a natural deep eutectic solvent (L-menthol and lactic acid at a molar ratio of 1:2) coupled with high-performance liquid chromatography was proposed, which was utilized for the separation and enrichment of bisdemethoxycurcumin, demethoxycurcumin and curcumin in Curcumae Longae Rhizoma and turmeric tea. The effects of independent parameters on extraction efficiency were optimized by single-factor analysis. Subsequently, four predominated parameters affecting the extraction procedure, including extractant volume, salt concentration, demulsifier consumption, and demulsification time, were further evaluated by a central composite design. Under the optimized conditions, the linear ranges of calibration curves were 0.005-0.5 µg/mL for bisdemethoxycurcumin, 0.004-0.4 µg/mL for demethoxycurcumin, and 0.0045-0.45 µg/mL for curcumin, respectively. In addition, the developed method provided low detection limits (0.1-0.4 ng/mL) and high enrichment factors (279-350). Its intra-day and inter-day precision were carried out by relative standard deviation ranging from 2.2 to 9.2%. Finally, the applicability of this method was assessed by the analysis of Curcumae Longae Rhizoma and turmeric tea samples. The results showed that these samples were detected successfully and the spiked recoveries over the range of 85.3-108.9% with relative standard deviations of 1.6-8.9% were attained, indicating its high relative recoveries with good precision in real sample analysis.

Vortex-assisted dispersive liquid-phase microextraction for the analysis of main active compounds from Zi-Cao-Cheng-Qi decoction based on a hydrophobic deep eutectic solvent.

In this study, a vortex-assisted hydrophobic deep eutectic solvent dispersive liquid-phase microextraction was developed and used for the extraction and preconcentration of six main active compounds in Zi-Cao-Cheng-Qi decoction. The deep eutectic solvent, prepared by mixing tetrabutylammonium chloride and hexanoic acid at a molar ratio of 1:1, was added to the sample solution containing the analytes. In the absence of disperser, the extractant was rapidly dispersed into fine droplets by the aid of vortex and adequately contacted with the analytes. Some key parameters affecting the approach including extraction solvent type and volume, sample phase pH, extraction time, centrifugation time, and salt concentration were investigated and optimized. Under the optimum conditions, enrichment factors of the target analytes were in the range of 3-330. The calibration graphs were linear with a correlation coefficient (r) ≥ 0.9929. The detection limits were 0.3-0.9 ng/mL, and the satisfactory precisions (relative standard deviations, 0.5-8.9%) and accuracies (relative recoveries, 91.1-102.2%) were also obtained. The developed method was rapid (only 2 min), eco-friendly, effective, and easy to operate. And it has been successfully applied to simultaneous extraction, enrichment, and determination of the main active compounds in a traditional Chinese medicinal formula coupled with high-performance liquid chromatography.

Determination of teicoplanin in human plasma by reverse micelle mediated dispersive liquid-liquid microextraction with high performance liquid chromatography.

A reverse micelle mediated dispersive liquid-liquid microextraction (RM-DLLME) combined with high performance liquid chromatography-ultraviolet detector (HPLC-UV) was developed for extraction and determination of 5 A2 components of teicoplanin (TA2-1, TA2-2, TA2-3, TA2-4, TA2-5) in human plasma, and the mechanism of RM-DLLME was analysed and explored. In this method, 80 µL of the reverse micelle solution of cetylpyridinium chloride/n-hexanol (15 mmol/L) was used as the extraction solvent for the separation, extraction and enrichment of the teicoplanin in plasma sample. All factors affecting the extraction efficiencies of the target analytes, such as the amounts of acetonitrile and chloroform, the type and volume of reverse micelle solution, pH and volume of sample phase, dispersant, salt addition, extraction mode and time, centrifugation rate and time, were investigated and optimized. Under the optimum conditions, the 5 A2 components of teicoplanin achieved effective enrichment with the enrichment factors of 228-347 and obtained good linearity in the range of 0.8375-100.5 µg/mL with correlation coefficients higher than 0.9960. The limits of detection were ranged between 0.5025-3.015 µg/mL. Relative standard deviation values of the method precisions were lower than 10.6% and the average recoveries were in the range of 82.7-111.3%. The determination results of the method were demonstrated with favorable characteristics, such as high enrichment, good selectivity and sensitivity, satisfactory precision and accuracy, and this method could be employed to analysis of the teicoplanin in human plasma samples.

Numerical analysis for the vertical bearing capacity of composite pile foundation system in liquefiable soil under sine wave vibration.

Composite pile foundation has been widely used in ground engineering. This composite pile foundation system has complex pile-soil interactions under seismic loading. The calculation of vertical bearing capacity of composite pile foundation is still an unsolved problem if the soil around piles is partially or completely liquefied under seismic loading. We have completed indoor shaking table model tests to measure the vertical bearing capacity in a liquefiable soil foundation under seismic loading. This paper will use a numerical approach to analyze the change of this vertical bearing capacity under seismic loading. Firstly, the Goodman contact element is improved to include the Rayleigh damping. Such an improvement can well describe the reflection and absorption of seismic waves at the interface of soil and piles. Secondly, the Biot's dynamic consolidation theory incorporated an elastoplastic model is applied to simulate the soil deformation and the generation and accumulation of pore water pressure under seismic loading. Thirdly, after verification with our indoor shaking table test data, this approach is used to investigate the effects of pile spacing on liquefaction resistance of the composite pile foundation in liquefiable soil. The time histories of pore water pressure ratio (PPR') are calculated for the liquefiable soil and the vertical bearing capacity in partially liquefied soil is calculated and compared with our indoor shaking table test data at the 3D, 3.5D, 4D, 5D and 6D cases (D is the pile diameter). It is found that the pile spacing has some influence on the extent of soil liquefaction between piles. The vertical bearing capacity varies with liquefaction extent of inter-pile soil. The optimization of pile spacing varies with liquefaction extent. These results may provide some reference for the design of composite pile foundation under seismic loading.

Self-assembled supramolecular dispersive liquid-phase microextraction for concentration and determination of anthraquinone compounds in Rhubarb.

Self-assembled supramolecular dispersive liquid-phase microextraction combined with high-performance liquid chromatography was developed and introduced for simultaneous extraction and determination of the trace level rhein, chrysophanol, and physcion in Rhubarb. Compared with conventional dispersive liquid-phase microextraction, the proposed method used a self-assembled ternary supramolecular consisting of the mixed extraction solvent (heptanol and nonanol) and dispersant (acetone) to achieve high enrichment factors of target analytes. Several factors affecting performance were investigated and optimized, including the mixed extraction solvent, type and volume of the dispersant, the pH of sample phase, salt concentration, shaking time, volume of sample phase, centrifugation time, and rate. Meanwhile, the method mechanism of self-assembled supramolecular dispersive liquid-phase microextraction was analyzed and described. Under the optimized extraction conditions, the enrichment factors of rhein, chrysophanol, and physcion were 116.5, 325.9, and 356.1, respectively. Good linearities (r ≥ 0.9952) for all analytes, low limits of detection (less than 0.04 ng/mL), satisfactory precisions (0.1-8.9%), and accuracies (recoveries, 88.2-104.1%) were achieved. The experimental results showed that the approach was simple, fast, with short extraction time, high enrichment factors, good linearities, and low limits of detection.

Comparison of three-phase hollow fiber liquid-phase microextraction based on reverse micelle with conventional two-phase hollow fiber liquid-phase microextraction and their applications for analysis of cinnamic acids in traditional Chinese medicines.

A novel three-phase hollow fiber liquid-phase microextraction was developed based on reverse micelle as extraction solvent and acceptor phase, and compared with conventional two-phase hollow fiber liquid-phase microextraction. Both procedures were used in the extraction and concentration of four cinnamic acids (caffeic acid, p-hydroxycinnamic acid, ferulic acid, and cinnamic acid) in traditional Chinese medicines prior to high-performance liquid chromatography analysis. Parameters affecting the two procedures were investigated and optimized to obtain the optimum enrichment factors. The mechanism of the developed procedure was explored and elucidated by comparison with conventional two-phase hollow fiber liquid-phase microextraction. Under the optimized conditions, the analytes' enrichment factors were between 50 and 118 for the proposed procedure, and 31-96 for conventional two-phase mode. Satisfactory linear ranges (r2  ≥ 0.99), detection limits (0.1-0.6 ng/mL), precisions (<9.2%), and accuracies (recoveries: 80-123.1%) were observed for the two procedures. The results showed that the enrichment capacity of the proposed procedure for the cinnamic acids is better than that of conventional two-phase procedure, and both are eco-friendly, simple, and effective for the enrichment and detection of cinnamic acids in traditional Chinese medicines.

Ballpoint connector-protected salt-oil-salt liquid phase microextraction for concentration and enrichment of trace anthraquinone compounds in rhubarb.

This study proposed a new ballpoint connector-protected salt-oil-salt liquid phase microextraction for extraction and enrichment of trace rhein and chrysophanol in rhubarb prior to determination of the analytes by high performance liquid chromatography. In this study, a handy ballpoint connector (between ballpoint tip and ink chamber) was used as extraction device, in which its cavity was filled with n-octanol, and the bare n-octanol in its two opening ends was covered with a thin layer of sodium chloride film. The design subtly assembled salt film onto ballpoint connector for extraction and enrichment, which greatly improved the enrichment factors of the target analytes. Moreover, the novel procedure and its extraction mechanism were described and analyzed, and several crucial parameters reflecting the extraction effect were investigated and optimized. Under optimum conditions, high enrichment factors (247 and 127), good linearities with r ≥ 0.9998, limits of detection (0.6-1.1 ng/mL), relative standard deviations of intra- and interday (2.2-8.8% and 4.3-8.9%), and average recoveries (97.6-98.1%), were obtained, respectively. The proposed method can not only eliminate the negative effects from viscosity and ion strength at high salt concentration of sample phase, but also make salting-out effect be focused on small area so as to maximize the extraction effect.

Three-phase hollow-fiber liquid-phase microextraction based on deep eutectic solvent as acceptor phase for extraction and preconcentration of main active compounds in a traditional Chinese medicinal formula.

A three-phase hollow-fiber liquid-phase microextraction based on deep eutectic solvent as acceptor phase was developed and coupled with high-performance capillary electrophoresis for the simultaneous extraction, enrichment, and determination of main active compounds (hesperidin, honokiol, shikonin, magnolol, emodin, and ß,ß'-dimethylacrylshikonin) in a traditional Chinese medicinal formula. In this procedure, two hollow fibers, impregnated with n-heptanol/n-nonanol (7:3, v/v) mixture in wall pores as the extraction phase and a combination (9:1, v/v) of methyltrioctylammonium chloride/glycerol (1:3, n/n) and methanol in lumen as the acceptor phase, were immersed in the aqueous sample phase. The target analytes in the sample solution were first extracted through the organic phase, and further back-extracted to the acceptor phase during the stirring process. Important extraction parameters such as types and composition of extraction solvent and deep eutectic solvent, sample phase pH, stirring rate, and extraction time were investigated and optimized. Under the optimal conditions, detection limits were 0.3-0.8 ng/mL with enrichment factors of 6-114 for the analytes and linearities of 0.001-13 µg/mL (r2 ≥ 0.9901). The developed method was successfully applied to the simultaneous extraction and concentration of the main active compounds in a formula of Zi-Cao-Cheng-Qi decoction with the major advantages of convenience, effectiveness, and environmentally friendliness.

Sodium dodecyl sulfate sensitized switchable solvent liquid-phase microextraction for the preconcentration of protoberberine alkaloids in Rhizoma coptidis.

A sodium dodecyl sulfate sensitized switchable solvent liquid-phase microextraction method was developed and applied to the preconcentration of active alkaloids in Rhizoma coptidis followed by high performance liquid chromatography determination. Before extraction, nonionic triethylamine was converted to its cationic form in the presence of carbon dioxide. Then, the ionic solvent carrying target analytes was once more reverted to its nonionic form by adding sodium hydroxide, as well as phase separation and analytes enrichment were realized simultaneously. Several parameters affecting the approach, such as concentration of sodium dodecyl sulfate, extraction solvent volume, sodium hydroxide concentration, sample phase pH, injection solvent type, and extraction time, were investigated and optimized. The possible microextraction mechanism of double micelle supramolecular inclusion was explored. Under the optimum conditions, the enrichment factors of four protoberberine alkaloids were from 101.8 to 152.0. The linear ranges (with r2  ≥ 0.990) were 0.032-4.23, 0.031-4.33, 0.0026-10.04, and 0.0013-4.13 µg/mL for epiberberine, coptisine, palmatine, and berberine, respectively. The detection limits were in the range of 0.16-0.32 ng/mL. Satisfactory accuracies (recoveries 98.8-104.6%) and precisions (RSDs 1.9-10.9%) were also obtained. The results showed that the approach is rapid, effective, eco-friendly, and easy-to-handle for the enrichment and detection of active alkaloids in Rhizoma coptidis.

[Protective Effects of Intraventricular Transplanted Human Umbilical Cord-derived Mesenchymal Stem Cells on Hypoxic Ischemic Brain Damages in Rats].

OBJECTIVES: To determine the therapeutic effect and protective mechanism of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on newborn rats with hypoxia ischemic brain damage (HIBD). METHODS: Umbilical cord (3-4 cm) was collected from a healthy male infant for preparation of hUC-MSCs using explants technique. The hUC-MSCs were cultured and labeled with BrdU. The differentiation function of MSCs was identified. Healthy SPF grade neonatal SD rats were randomly divided into sham (n =30), HIBD (n =36) and hUC-MSCs treated HIBD (n =32) groups. BrdU-labeled hUC-MSCs were injected into the right ventricle of the rats in the hUC-MSCs treatment group 24 h after successful induction of HIBD. The growth and development of the rats were recorded. The neurological behavior of the rats were evaluated with Longa score method 3 weeks after hUC-MSCs transplantation. The survival, migration, differentiation and pro-differentiation of the transplanted hUC-MSCs were measured using immunological fluorescence method. RESULTS: Rats in the hUC-MSCs treatment group had significant higher weight gain and lower Longa scores (at the second and the third week post transplantation) than those in the HIBD group (P<0.05). BrdU positive cells were found in brain tissues 3 weeks after transplantation, and they were mainly distributed in the damaged hippocampus and cerebral cortex. Three weeks after transplantation, the total signal strength of glial fibrillary acidic protein (GFAP) or neuron-specific enclase (NSE) gradually increased. CONCLUSION: Transplanted hUC-MSCs can migrate brain damages through differentiating into neuron-like cells and promoting endogenous neurological differentiations.

Graphene/dodecanol floating solidification microextraction for the preconcentration of trace levels of cinnamic acid derivatives in traditional Chinese medicines.

A novel graphene/dodecanol floating solidification microextraction followed by HPLC with diode-array detection has been developed to extract trace levels of four cinnamic acid derivatives in traditional Chinese medicines. Several parameters affecting the performance were investigated and optimized. Also, possible microextraction mechanism was analyzed and discussed. Under the optimum conditions (amount of graphene in dodecanol: 0.25 mg/mL; volume of extraction phase: 70 µL; pH of sample phase: 3; extraction time: 30  min; stirring rate: 1000 rpm; salt amount: 26.5% NaCl; volume of sample phase: 10 mL, and without dispersant addition), the enrichment factors of four cinnamic acid derivatives ranged from 26 to 112, the linear ranges were 1.0 × 10-2 -10.0 µg/mL for caffeic acid, 1.3 × 10-3 -1.9 µg/mL for p-hydroxycinnamic acid, 2.8 × 10-3 -4.1 µg/mL for ferulic acid, and 2.7 × 10-3 -4.1 µg/mL for cinnamic acid, with r2 ≥ 0.9993. The detection limits were found to be in the range of 0.1-1.0 ng/mL, and satisfactory recoveries (92.5-111.2%) and precisions (RSDs 1.1-9.5%) were also achieved. The results showed that the approach is simple, effective and sensitive for the preconcentration and determination of trace levels of cinnamic acid derivatives in Chinese medicines. The proposed method was compared with conventional dodecanol floating solidification microextraction and other extraction methods.

Development of a novel hollow-fiber liquid-phase microextraction based on oil-in-salt and its comparison with conventional one.

A novel hollow-fiber liquid-phase microextraction based on oil-in-salt was proposed and introduced for the simultaneous extraction and enrichment of the main active compounds of hesperidin, honokiol, shikonin, magnolol, emodin, and ß,ß'-dimethylacrylshikonin in a formula of Zi-Cao-Cheng-Qi decoction and the single herb, Fructus Aurantii Immaturus, Cortex Magnoliae Officinalis, Radix et Rhizoma, and Lithospermum erythrorhizon, composing the formula prior to their analysis by high-performance liquid chromatography. The results obtained by the proposed procedure were compared with those obtained by conventional hollow-fiber liquid-phase microextraction, and the proposed procedure mechanism was described. In the procedure, a hollow-fiber segment was first immersed in organic solvent to fill the solvent in the fiber lumen and wall pore, and then the fiber was again immersed into sodium chloride solution to cover a thin salt membrane on the fiber wall pore filling organic solvent. Under the optimum conditions, the enrichment factors of the analytes were 0.6-109.4, linearities were 0.002-12 µg/mL with r2  ≥ 0.9950, detection limits were 0.6-12 ng/mL, respectively. The results showed that oil-in-salt hollow-fiber liquid-phase microextraction is a simple and effective sample pretreatment procedure and suitable for the simultaneous extraction and concentration of trace-level active compounds in traditional Chinese medicine.

[Effect of Berberine on the Insulin Resistance and TLR4/IKKbeta/NF-kappaB Signaling Pathways in Skeletal Muscle of Obese Rats with Insulin Resistance].

OBJECTIVE: To explore the possible mechanism of berberine improve insulin resistance in skeletal muscle of obese rats. METHODS: Forty Wistar rats were divided into normal control group (NC group, n =10) and high fat food group (HF group, n=30). After the obese model rats established successfully, the rats of NC group (n=10) and HF group (n=10) were sacrificed. The level of fasting plasma endotoxin (ET) was detected. The expression of Toll-like receptor 4 (TLR4) mRNA in skeletal muscle were detected by real time quantitative PCR. The expression of TLR4, IkappaB kinase beta (IKKbeta), phospho-IKKbeta(Ser181) (p-IKKbeta(Ser181)), nuclear factor-kappaB (NF-kappaB), tumor necrosis factor-alpha (TNF-alpha), insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phospho-IRS-1(Ser307) (p-IRS-1(ser307)) and the tyrosine phosphorylation of IR and IRS-1 (p-IR(Tyr) and p-IRS-1(Tyr)) protein in skeletal muscle were detected by Western blot. The twenty HF group rats were randomly divided into two group: the fat model control group (FC group, n=10) were fed with high fat diet and distilled water. The fat berberine group (FB group, n=10) were fed with high fat diet and berberine. All rats were sacrificed after effective interventions of eight weeks. The same indexes as the first part of experiment were detected. Results The results showed that the level of ET was increased. The TLR4/IKKneta/NF-kappaB signaling pathway is activated and the expression of TNF-alpha was increased of the skeletal muscle in obese rats. However, the insulin signaling pathways of the skeletal muscle in obese rats was inhibited. Berberine could reduce the level of ET of obese rats, down-regulate the TLR4/IKKbeta/NF- kappaB inflammation signaling pathway and improve insulin resistance of skeletal muscle in obese rats. CONCLUSION: Our study revealed that berberine could reduce the level of ET of obese rats, down-regulate the TLR4/IKKbeta/NF-kappaB inflammation signaling pathway in skeletal muscle and berberine can improve insulin resistance of skeletal muscle through inhibiting the active of the TLR4/IKKbeta/NF-kappaB signaling pathway.

[Umbilical Cord-derived Mesenchymal Stem Cells Grafts for Neonatal Rats Model of HIBD: the Mechanism of PI3K/Akt Signaling Pathway].

OBJECTIVE: To investigate the role of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) signaling pathway for umbilical cord-derived mesenchymal stem cells (UC-MSCs) treating in neonatal rats with hypoxia-ischemia brain damage (HIBD). METHODS: P10 SD rats were divided into sham group, MSCs group, inhibitor (LY 294002) group (LY group) and HIBD group randomly. To establish a neonatal rat model of HIBD, UC-MSCs labeled with Brd U were transplanted into the lateral ventricle of rats. At 24 and 48 h after transplantation, the number of apoptotic cells was detected by TUNEL, while the expression of caspase3 protein and phosphorylation of Akt (P-Akt) were quantified by Western blot. RESULTS: At 24 and 48 h after transplantation, both the apoptotic cells and caspase3 protein expression in MSCs group were less than those in LY group and HIBD group (P<0. 05), while the expression of P-Akt was higher than those in LY group and HIBD group (P<0.05), and with the passage of time after transplantation, the expression of each index showed a downward trend. CONCLUSION: The apoptotic cells of brain and the expression of caspase3 protein decrease, while the expression of P-Akt increase. PI3K/Akt signaling pathway may be an important mechanism for UC-MSCs transplantation in HIBD rats.

Rapid screening of different types of antitumor compound groups from traditional chinese medicine by hollow fiber cell fishing with high performance liquid chromatography.

A novel hollow fiber cell fishing with high performance liquid chromatography (HFCF-HPLC) was extended and used to screen flavonoid and anthraquinone active compound groups simultaneously from traditional Chinese medicines (TCMs). In this study, three cells (MCF-7, SGC7901, and MADB-106) were seeded on the inner wall of the hollow fiber employed to screen bioactive components from TCM water decoction. The variables influencing HFCFHPLC, such as cell seeding time, screening stirring rate and time, and active compound concentration, were investigated and optimized. The surface property of the hollow fiber seeded with cells, the cell survival rate under different conditions, the nonspecific binding between active centers in the fiber and the target compounds, and the repeatability and recovery of HFCF-HPLC were analyzed and validated. Certain structures of the compounds fished by HFCF-HPLC were identified after comparing the retention times of the reference substances. To verify preliminarily the binding site between the bioactive components and cells, we separated the cell membrane and cell organelle from live MCF-7 cells. We then employed the cell membrane, cell organelle, and the whole cells to screen simultaneously the active compounds. The cell fishing factor of the active compound was calculated and discussed as the index of cell-drug binding ability in HFCFHPLC. Tamoxifen as a positive control and indomethacin as a negative control were screened by HFCF-HPLC to verify the method. The results indicate that HFCF-HPLC is an effective and reliable method for the screening and analysis of bioactive components. Moreover, this method can be applied to predict bioactive candidates in TCMs.

[Intracerebral transplantation of human umbilical cord-derived mesenchymal stem cells in neonatal rat model of hypoxic-ischemic brain damage: protective effect to injured brain].

OBJECTIVE: To study the brain protection and the possible mechanism of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in neonatal rat model of hypoxic-ischemic brain damage (HIBD). METHODS: Successfully establishing a neonatal rat model of HIBD, hUC-MSCs labeled with BrdU were transplanted into the lateral ventricle 24 hours after HIBD. The number of apoptotic cells and the expression of Caspase-3 were detected by TUNEL and Western blot respectively at 24 and 48 hours after transplantation. The neurological functions of HIBD rats were evaluated by Longa score, and the survival, differentiation and pro-differentiation effects of hUC-MSCs were identified by immunofluorescence at 1 to 3 weeks after transplantation. RESULTS: At 24 and 48 hours after transplantation, apoptotic cells and Caspase-3 expression in the MSCs group were less than in the HIBD group (P<0.05). At 2 and 3 weeks after transplantation, the Longa score in the MSCs group was lower than in the HIBD group (P<0.05). After transplantation, positive cells labeled with BrdU were seen in the brain tissue. The expression levels of glial fibrillary acidic protein (GFAP) and neuron specific esterase (NSE) in the MSCs group were higher than in the HIBD and sham-operated control groups (P<0.05), and increased gradually with the transplantation time (P<0.05). CONCLUSIONS: hUC-MSCs transplantation in HIBD rats can inhibit Caspase-3 expression and reduce apoptotic cells in the early stage, and in the later period, the survival hUC-MSCs can differentiate into neural-like cells and promote the differentiation of endogenous neural-like cells, providing protective effects to brain.

[Application of oxytocin antagonists in thaw embryo transfer].

OBJECTIVE: To study the effects of oxytocin antagonists-atosiban on pregnancy outcome after thaw embryo transfer (TET). METHODS: Between Jul. and Dec. 2012, a total of 120 women undergoing TET in Reproductive Medical Center, General Hospital of Tianjin Medical University were randomly allocated into atosiban and control group. They were all transferred 2 or 3 top quality embryos at phase of 7-8 cells . Patients in atosiban group were administered by intravenous administration of atosiban before 30 minutes of embryo transfer with a total administered dose of 37.5 mg. In the control group, no special treatment was given before embryo transfer. All patients in 2 groups underwent progesterone luteal support regularly after embryo transfer, then the clinical rate of pregnancy, implantation and early abortion was compared. RESULTS: The clinical pregnancy rate per cycle and implantation rate per transfer were 60% (36/60) and 30.0% (48/160) in the atosiban group, which were higher than 42% (25/60) and 20.3% (31/153) in the control group (all P < 0.05). Early abortion rate was 6% (2/36) in the atosiban group, which was no statistical difference comapring with control group [16% (4/25), P > 0.05]. CONCLUSION: It was suggested that atosiban treatment before embryo transfer can improve the outcome of pregnancy, and increase clinical pregnancy rate and implantation rate after TET.

A new ionic liquid-water-organic solvent three phase microextraction for simultaneous preconcentration flavonoids and anthraquinones from traditional Chinese prescription.

A novel technique, ionic liquid-water-organic solvent three phase microextraction (ILWOS-3p-ME) was developed and introduced for simultaneous preconcentration and determination of flavonoids and anthraquinones in Chinese herbal formula and its preparations. This technique was performed in one step by using a syringe. High performance liquid chromatography with an UV-detector (HPLC/UV) was subsequently conducted. Two solvents with different densities (organic solvent and ionic liquid with densities less than and higher than water, respectively) were separately placed in a syringe, which was used as an extraction device. A cloudy emulsion was formed by manually shaking the syringe. The mixture was allowed to stand for several minutes; afterward, the emulsion readily separated into three phases: an upper organic solvent extraction phase; a middle aqueous sample phase; and a lower ionic liquid extraction phase. Both the upper and lower layers were transferred to a small Eppendorf (EP) tube. Conducting ILWOS-3P-ME with HPLC/UV, we simultaneously determined the bioactive components of flavonoids and anthraquinones in traditional Chinese medicine. ILWOS-3P-ME is a simple, rapid, practical, and effective method to extract and preconcentrate of different types of trace bioactive components from traditional Chinese medicine simultaneously.