[Investigation on bupleurum resources in northwest area of Hubei Province].

OBJECTIVE: To investigate the species and the distribution of Bupleurum genus in northwest of Hubei province and provide basis for the standardization planting of Bupleurum in the region. METHODS: Investigated and collected specimens on the spot, com- pared them with literatures and specimen collected before. RESULTS: The main species of Bupleurum plants was B. marginatum, only very few of them was B. scorzonerifolium, no B. chinense was found in northwest of Hubei province. CONCLUSION: B. marginatum is the mainstream species of Bupleurum plants and the roots of B. marginatum are the actual source of commodity with the name of "Beichaihu (the roots of B. chinense)" in northwest of Hubei province.

Pharmacokinetic and tissue distribution study of eight volatile constituents in rats orally administrated with the essential oil of Artemisiae argyi Folium by GC-MS/MS.

Artemisia argyi is commonly used as a remedy for gynecological and respiratory disease in traditional Chinese medicine. The essential oil is considered as the major active ingredients of A. argyi, mainly composed of eucalyptol, α-thujone, camphor, borneol, bornyl acetate, eugenol, ß-caryophyllene, and caryophyllene oxide, while limited study addresses the in vivo disposition of these volatile ingredients. In present study, a rapid, sensitive and selective GC-MS/MS method has been developed and validated for the quantification of the eight volatile constituents in rat plasma and tissues after orally dosing with the essential oil of Artemisiae Argyi Folium (AAEO) using naphthalene as an internal standard (IS). The analytes were extracted from biosamples by liquid-liquid extraction with hexane/ethyl acetate. The GC separation was achieved on a TG-5SILMS column (30 m × 0.25 mm, 0.25 µm film thickness) and MS detection was performed on selective reaction monitoring (SRM) mode. The assay had a lower limit of quantification (LLOQ) less than 2 ng/ml for the analytes with good linearity (r ≥ 0.9907). Their disposition profile in rat plasma and tissues was characterized after orally giving AAEO, and the data revealed the analytes underwent rapid absorption from GI tract and were mainly transferred to the liver, heart, kidney, lung, and spleen with prompt elimination. The results provided a meaningful basis for guiding the pharmacodynamic study and clinical applications of this herbal medicine.

Efficient synthesis and biological evaluation of some 2,4-diamino-furo[2,3-d]pyrimidine derivatives.

The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, reacted with ammonia to give ethyl 3,4-dihydro-6-methyl-4-oxo-2-arylamino-furo[2,3-d]pyrimidine-5-carboxylate 3. Further reaction of 3 with POCl(3) and various amines generated ethyl 4-alkylamino-2-arylamino-6-methyl-furo[2,3-d]pyrimidine-5-carboxylate 5 in good yields. Their structures were confirmed by (1)H NMR, EI-Ms, IR and elemental analysis. Compound 5b was further analyzed by single crystal X-ray diffraction. Compound 5 exhibited cytotoxicity against two lung cancer cell lines. For example, compound 5a showed the best inhibition activities against A459 with IC(50) 0.8µM.

[Nitrogen and Phosphorus Removal from Low C/N Municipal Wastewater Treated by a SPNDPR System with Different Aeration and Aerobic Times].

An anaerobic (180 min)/aerobic operated sequencing batch reactor (SBR) fed with urban sewage was optimized by regulating the aeration quantity to investigate the deep-level nitrogen (N) and phosphorus (P) removal. The amount of aeration was regulated by adjusting the volume of gas per unit volume of reactor passed in unit time, when the unit is L·(min·L)-1, from 0.125 L·(min·L)-1 gradually to 0.025 L·(min·L)-1, and aerobic times from 3 h to 6 h. The experimental results show that the effluent NH4+-N, NO2--N, NO3--N, and PO43--P concentrations of the optimized SPNDPR system were 0, 8.62, 0.06, and 0.03 mg·L-1. The effluent TN concentration was about 9.22 mg·L-1, and the TN removal efficiency was up to 87.08%. When the aeration quantity was decreased from 0.125 L·(min·L)-1 to 0.100 L·(min·L)-1; then decreased to 0.075 L·(min·L)-1, the nitrification rate of the system recovered and stabilized at 0.16 mg·(L·min)-1. However, when the aeration quantity continuously decreased to 0.050 L·(min·L)-1 and then to 0.025 L·(min·L)-1, the nitrification rate decreased to 0.09 mg·(L·min)-1 and 0.06 mg·(L·min)-1. With reduction of the aeration quantity[from 0.125 L·(min·L)-1 to 0.100, 0.075, 0.050 and 0.025 L·(min·L)-1] and extension of aerobic time (from 3 h to 6 h), the TN removal efficiency increased gradually from 62.82% to 87.08%, and the SND efficiency increased from 19.57% to 72.11%. It was proven that reducing the aeration quantity can enhance the SPND function and deep denitrification by the system was realized. By enhancing the anaerobic intracellular carbon storage and aerobic phosphorus uptake, denitrifying phosphorus removal, partial nitrification, and endogenous nitrification were achieved. The SPNDPR system, after reducing aeration and prolonging aerobic time, was able to realize deep-level denitrification and dephosphorization using low C/N urban sewage.

[Effect of the Influent C/P Ratio on the Nutrient Removal Characteristics of the SNEDPR System].

This study focuses on the nitrogen (N) and phosphorus (P) removal characteristics in a simultaneous nitrification-endogenous denitrification and phosphorus removal (SNEDPR) system at different influent C/P ratios. An extended anaerobic/low aerobic (dissolved oxygen:0.5-1.0 mg·L-1) sequencing batch reactor (SBR) fed with municipal sewage was studied by adjusting different C/P ratios (10, 15, 20, 30, and 60). The experimental results show that the proper reduction of the influent C/P ratio (C/P ratio reduced from 60 to 30) enhances the competitive advantages of phosphorus-accumulating organisms (PAOs) in the SNEDPR system. The highest phosphorus removal efficiency was achieved at a C/P ratio of 30, with the anaerobic phosphorus release rate (PRR) and aerobic phosphorus uptake rate (PUR, used as P/MLSS) reaching 3.5 mg·(g·h)-1 and 4.2 mg·(g·h)-1 respectively, and an average effluent PO43--P concentration below 0.3 mg·L-1. The percentage of PAOs contributing to the storage of endogenesis carbon (PPAO, An) reached 88.1%. However, a poor phosphorus removal performance was observed with further reduction of the influent C/P ratios to 10; both the PO43--P removal efficiency and PPAO, An decreased from 38.1% and 82.4% to 3.1% and 5.3%, respectively. The PRR and PUR were 0.2 mg·(g·h)-1 and 0.24 mg·(g·h)-1, respectively. The COD removal performance was not affected by the decreasing influent C/P ratios; the average COD removal efficiency stabilized at 85%. In addition, the nitrification performance became worse with decreasing C/P ratios (from 60 to 20) because the effluent NH4+-N and NO2--N concentrations increased from 0 and 6.9 mg·L-1 to 5.1 mg·L-1 and 16.2 mg·L-1, respectively. The nitrificaton performance recovered when the C/P ratios further decreased to 10, but the nitrite accumulation was disturbed as both the effluent NH4+-N and NO2--N concentrations reduced to 0. The effluent NO3--N concentration increased from 0.08 mg·L-1 to 14.1 mg·L-1. The SNED efficiency first decreased from 62.1% to 36.4% and then increased to 56.4%. The advantageous competition of glycogen accumulating organisms (GAOs) improved when the influent C/P ratio was lower than 15. The enhancement of the endogenous denitrification ability of GAOs might explain the recovery denitrification performance of the system when the influent C/P ratios decreased from 20 to 10.

[Effect of Different Sludge Retention Time (SRT) Operations on the Nutrient Removal Characteristics of a SNEDPR System].

This study focuses on the nitrogen (N) and phosphorus (P) removal characteristics in a simultaneous nitrification endogenous denitrification and phosphorus removal (SNEDPR) system operating at different sludge retention time (SRT). Four extended anaerobic/low aerobic (dissolved oxygen:0.5-1.0 mg·L-1)-operated sequencing batch reactors (SBRs) fed with municipal sewage were studied at different SRT of 5, 10, 15, and 25 d. The experimental results show that a shorter SRT at an SRT ≥ 10 d enhances the competitive advantage of PAOs in the system and an efficient phosphorus removal performance of the SNEDPR system was achieved at a SRT of 10 d and 15 d. Especially at an SRT of 10 d; the average PPAOs, An was 68.4%, the PRA and PUA reached 31.9 and 34.3 mg·L-1, respectively. The nitrification performance of the system was not affected by SRT changes. The most efficient nitrogen removal performance was achieved at a SRT of 15 d, with a high average TN removal and SNED efficiencies reaching 89.6% and 71.8%, respectively. At a SRT ≥ 10 d, the COD removal performance of the SNEDPR system was also not affected by SRT changes. The COD removal efficiencies were higher than 78%. However, when the SRT was shortened to 5 d, the C, N, and P performances of the system worsened due to the loss of biomass; the SNED and PO43--P removal efficiencies were as low as 5.7% and 0.5%, respectively. In addition, at an SRT=15 d, the sludge-settling performance of the system was the best. The SV and SVI were 20% and 64 mL·g-1, respectively, and the sludge concentration increased with the extension of the SRT. Under long SRT (25 d) operation, the system showed a good resistance to shock loads, but the sedimentation performance of the sludge deteriorated.

[Characteristics of Ammonia Adsorption and Kinetics by Nitrifying Sludge Immobilized Pellets].

In order to explore the characteristics and mechanisms of ammonia adsorption by both nitrifying sludge waterborne polyurethane (WPU)-immobilized pellets and nitrifying sludge polyvinyl alcohol-sodium alginate (PVA-SA)-immobilized pellets, the ammonia adsorption characteristics of immobilized pellets under different initial ammonia concentrations, and the influences of temperature, pH, and salinity on ammonia adsorption were studied respectively. Moreover, the adsorption isotherms, thermodynamics, and kinetics model analysis were employed to investigate the adsorption process. The adsorption capacity increased as the initial ammonia concentration increased. The optimal pH was 7.0, and salinity and temperature exhibited an inhibitory effect on adsorption. The adsorption capacity for nitrifying sludge-immobilized pellets was higher than the pellets with no sludge; the adsorption capacity of WPU pellets was higher than that of PVA-SA pellets. The thermodynamics demonstrated that the adsorption process was a spontaneous exothermic process and that low temperature favored ammonia adsorption. The process was fitted to the Langmuir and Freundlich isotherm. It exhibited multilevel adsorption at higher energy (Freundlich isotherm) and single adsorption at lower energy by electrostatic force (Langmuir isotherm). Additionally, the process was consistent with the pseudo-second-order kinetic model, as it explained that chemical adsorption was the primary mechanism of ammonia adsorption by immobilized pellets.

[Nitrite Accumulation Characteristics of Partial Denitrification in Different Sludge Sources Using Sodium Acetate as Carbon Source].

In order to explore the characteristics of nitrite accumulation during the operational period of partial denitrification in different sludge sources using sodium acetate as a carbon source, No.1 SBR and No.2 SBR were used to inoculate with surplus sludge taken separately from a secondary sedimentation tank of a sewage treatment plant and simultaneous nitrification and denitrifying phosphorus removal system. By reasonably controlling the initial nitrate concentration and anoxic time, partial denitrification was realized. The carbon and nitrogen removal characteristics under different initial COD and NO3--N concentrations were investigated. The results showed that, using sodium acetate as the carbon source, the partial denitrification process in No.1 SBR and No.2 SBR sludge successfully began in 21 d and 20 d, respectively. The accumulation of NO2--N and nitrite accumulation rate (NAR) in reactors were maintained at high levels (12.61 mg·L-1, 79.76% and 13.85 mg·L-1, 87.60%, respectively). When the initial NO3--N concentration of No.2 SBR was 20 mg·L-1 and the initial COD concentration increased from 60 mg·L-1 to 140 mg·L-1, the operation time for achieving the highest NO2--N accumulation in the system was shortened from 160 min to 6 min. The NO3--N ratio of the denitrification rate (in VSS) increased from 3.84 mg·(g·h)-1 to 7.35 mg·(g·h)-1. Increased initial COD concentration was beneficial to the accumulation of NO2--N during partial denitrification. When the initial COD concentration of No.2 SBR was 100 mg·L-1 and the initial NO3--N concentration increased from 20 mg·L-1 to 30 mg·L-1, NAR was maintained above 90% and up to 100% (the initial NO3--N concentration was 25 mg·L-1). When the initial NO3--N concentration was ≥ 35 mg·L-1, insufficient COD caused NO3--N to be completely reduced to NO2--N. Under different initial COD concentrations (80, 100, or 120 mg·L-1) and different initial NO3--N concentrations (20, 25, 30, or 40 mg·L-1), the nitrogen and carbon removal and partial denitrification performance of the No.2 SBR was better than that of No.1 SBR.

[Operating Characteristics of a DPR-SNED System Treating Low C/N Municipal Wastewater and Nitrate-containing Sewage].

In order to realize the simultaneous treatment of low C/N municipal wastewater and high nitrate wastewater, a sequencing batch reactor (SBR), inoculated with activated sludge, was used to initiate the denitrifying phosphorus removal coupled with simultaneous nitrification and endogenous denitrification (DPR-SNED). The anaerobic/anoxic/hypoxic durations and dissolved oxygen (DO) concentration were appropriately controlled, and the nitrogen and phosphorus removal characteristics were examined. The experimental results demonstrated that, in the anaerobic/hypoxia operation mode, with an anaerobic duration of 3 h and DO concentration of 0.5-1.0 mg·L-1, the simultaneous nitrification of phosphorus removal (SNEDPR) system successfully began in 60 d. The effluent PO43--P concentration was below 0.5 mg·L-1, the nutrient and COD removal efficiencies were stably maintained above 90% and 80%, respectively, and the SNED efficiency and CODins efficiency reached 70% and 95%, respectively. When the operation mode was anaerobic/anoxic/hypoxic and nitrate-containing sewage was added at the beginning of the anoxic stage, DPR-SNED was achieved with the effluent PO43--P concentration<0.5 mg·L-1, nutrient and COD removal efficiencies above 88% and 90%, respectively, and SNED efficiency and CODins efficiency maintained at 62% and 90%, respectively. After the successful initiation of DPR-SNED, enhanced intracellular carbons storage was achieved by phosphorus-and glycogen-accumulating organisms using the limited carbons in raw municipal wastewater to provide sufficient carbon sources for subsequent nutrient removal. In addition, the endogenous partial denitrification ensured the efficient nitrogen removal performance of the DPR-SNED system at low C/N conditions (average 4).

[Simultaneous Nitrogen and Phosphorus Removal Characteristics of An Anaerobic/Aerobic Operated SPNDPR System Treating Low C/N Urban Sewage].

This study focused on the nitrogen (N) and phosphorus (P) removal performance optimization of simultaneous partial nitrification-endogenous denitrification and phosphorus removal (SPNDPR) systems. An anaerobic (180 min)/aerobic operated sequencing batch reactor (SBR) fed with domestic wastewater was used for investigating the startup and optimization of SPNDPR by regulating the aeration rate and aerobic duration time. The experimental results showed that at an aerobic aeration rate of 0.8 L·min-1 and aerobic duration time of 150 min, the effluent PO43--P concentration was about 1.5 mg·L-1, with the effluent NH4+-N and NO3--N concentrations gradually decreasing from 10.28 and 8.14 mg·L-1 to 0 and 2.27 mg·L-1, respectively, and effluent NO2--N concentration increasing to 1.81 mg·L-1. When the aeration rate was increased to 1.0 L·min-1 and the aerobic duration time was shortened to 120 min, the phosphorus removal and partial nitrification-endogenous performance of the system gradually increased, but the total nitrogen (TN) removal performance initially decreased and then gradually increased. The final effluent PO43--P and NH4+-N were stably below 0.5 and 1.0 mg·L-1, respectively, aerobic nitrite accumulation and simultaneous nitrification-endogenous denitrification (SND) efficiencies were 98.65 and 44.20%, respectively, and TN removal efficiency was 79.78%. The concurrence of aerobic phosphorus absorption, denitrifying phosphorus removal, partial nitrification, and nitrification-endogenous in the aerobic stage of the SPNDPR system ensured the simultaneous removal of N and P from low C/N wastewater.

Combination therapy versus pharmacotherapy, endoscopic variceal ligation, or the transjugular intrahepatic portosystemic shunt alone in the secondary prevention of esophageal variceal bleeding: a meta-analysis of randomized controlled trials.

Patients with liver cirrhosis and variceal hemorrhage are at increased risk of rebleeding. We performed a meta-analysis toassess the clinical efficacy of combination therapy (pharmacotherapy and endoscopic variceal ligation (EVL)) compared with pharmacotherapy, EVL, or transjugular intrahepatic portosystemic shunt (TIPS) alone in the prevention of rebleeding and mortality. A literature search of MEDLINE, EMBASE, and the Cochrane Controlled Trials Register, up until November 2016, identified relevant randomized controlled trials. Data analysis was performed using Stata 12.0. Regarding overall mortality, combination therapy was as effective as EVL, pharmacotherapy, and TIPS (relative risk (RR) = 0.62, 95% confidence interval (CI): 0.36-1.08, RR=1.05, 95% CI: 0.68-1.63, and RR=1.39, 95% CI: 0.92-2.09, respectively). Combination therapy was as effective as EVL and pharmacotherapy alone in reducing blood-related mortality (RR=0.43, 95% CI: 0.15-1.25, and RR=0.42, 95% CI: 0.17-1.06), whereas TIPS was more effective than combination therapy (RR=5.66, 95% CI: 1.02-31.40). This was also the case for rebleeding; combination therapy was more effective than EVL and pharmacotherapy alone (RR=0.57, 95% CI: 0.41-0.79, and RR=0.65, 95% CI: 0.48-0.88), whereas TIPS was more effective than combination therapy (RR=9.42, 95% CI: 2.99-29.65). Finally, regarding rebleeding from esophageal varices, combination therapy was as effective as EVL alone (RR=0.59, 95% CI: 0.33-1.06) and was more effective than pharmacotherapy alone (RR=0.58, 95% CI: 0.40-0.85), although was less effective than TIPS (RR=2.20, 95% CI: 1.22-3.99). TIPS was recommended as the first choice of therapy in the secondary prevention of esophageal variceal bleeding.

Effects of quercetin nanoliposomes on C6 glioma cells through induction of type III programmed cell death.

BACKGROUND: Quercetin has been shown to induce apoptosis in a number of cancer cell lines, but a quercetin-loaded nanoliposomal formulation with enhanced antitumor activity in C6 glioma cells and its effect on cancer cell death has not been well studied. The aim of this study was to examine if quercetin-loaded liposomes (QUE-NL) has enhanced cytotoxic effects and if such effects involve type III programmed cell death in C6 glioma cells. METHODS: C6 glioma cells were treated with QUE-NL and assayed for cell survival, apoptosis, and necrosis. Levels of reactive oxygen species production and loss of mitochondrial membrane potential (ΔΨm) were also determined by flow cytometry assay to assess the effects of QUE-NL. ATP levels and lactate dehydrogenase activity were measured, and Western blotting was used to assay cytochrome C release and caspase expression. RESULTS: QUE-NL induced type III (necrotic) programmed cell death in C6 glioma cells in a dose-dependent and time-dependent manner. High concentrations of QUE-NL induced cell necrosis, which is distinct from apoptosis and autophagy, whereas liposomes administered alone induced neither significant apoptosis nor necrosis in C6 glioma cells. QUE-NL-induced ΔΨm loss and cytochrome C release had no effect on caspase activation, but decreased ATP levels and increased lactate dehydrogenase activity indicated that QUE-NL stimulated necrotic cell death. CONCLUSION: C6 glioma cells treated with QUE-NL showed a cellular pattern associated with necrosis without apoptosis and was independent of caspase activity. Nonapoptotic cell death induced by high concentrations of QUE-NL for controlling caspase-independent type III programmed cell death may provide the basis for novel therapeutic approaches to overcome avoidance of apoptosis by malignant cells.