Search

Lycium barbarum, a famous Chinese medicinal herb, has a long history of use as a traditional remedy for male infertility. Polysaccharides are the most important functional constituent in L. barbarum fruits. We systematically investigated the effect of L. barbarum polysaccharides (LBP) on rat testis damage induced by a physical factor (43 degrees C heat exposure), on DNA damage of mouse testicular cells induced by a chemical factor (H2O2), and on sexual behavior and reproductive function of hemicastrated male rats. The results showed that LBP provided a protective effect against the testicular tissue damage induced by heat exposure. When compared with negative control, a suitable concentration of LBP significantly increased testis and epididymis weights, improved superoxide dismutase (SOD) activity, and raised sexual hormone levels in the damaged rat testes. LBP had a dose-dependent protective effect against DNA oxidative damage of mouse testicular cells induced by H2O2. LBP improved the copulatory performance and reproductive function of hemicastrated male rats, such as shortened penis erection latency and mount latency, regulated secretion of sexual hormones and increased hormone levels, raised accessory sexual organ weights, and improved sperm quantity and quality. The present findings support the folk reputation of L. barbarum fruits as an aphrodisiac and fertility-facilitating agent, and provide scientific evidence for a basis for the extensive use of L. barbarum fruits as a traditional remedy for male infertility in China.

A high performance liquid chromatographic (HPLC) method was established for the simultaneous determination of three main pollutants (josamycin, theophylline and paracetamol) in pharmaceutical waste water. The three drug residues were concentrated with a SepPak C18 solid-phase extracted column, and eluted with methanol. The HPLC separation was performed on a Hypersil ODS column (200 mm x 4.6 mm i.d.) with a gradient eluting system of 0.025 mol/LKH2PO4-H3PO4 (pH 2.75)-methanol. The detection wavelengths were 230 nm for josamycin, 272 nm for theophylline, and 243 nm for paracetamol. The linear ranges of the drugs were 0.1-100 mg/L with correlation coefficients between 0.9993 and 0.9995. The recoveries were more than 93%, and relative standard deviations (n = 6) were less than 2.1%. The detection limits (S/N = 3) were less than 1.0 microg/L.

To investigate the protective effect of lycium barbarum polysaccharides (LBP) on DNA oxidative damage of testicle cells induced by hydrogen peroxide (H2O2). The single cell gel electrophoresis(SCGE) was used to detect the breakage of DNA strand and analyze LBP protection against oxidation damage in testicle cells treated by different concentrations of LBP for 1 hour firstly, and then cultured with 100 mumol/L H2O2 for 25 min. The results showed that a certain moment action by H2O2 could induce the breakage of DNA strand. The pretreatment of LBP (50, 100, 200, 400 micrograms/ml) significantly decreased the frequencies of cells with tail moment and the tail length of testicle cells treated by H2O2. It is suggested that LBP itself could not cause the oxidation damage, but it could clean out the free-radical and restrain the DNA damage of testicle cells caused by the oxidative stress.

A method for the determination of 16 functional components of ginkgo dietary supplement tea such as catechin, vitexin, puerarin, isoflavoues aglycone, silymarin, quercetin, luteolin, apigenin, naringenin, hesperitin dihydrochalcone, kaempferol, hesperitin, isorhamnetin, baicalein, nobiletin and tangeretin by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was proposed. The conditions of chromatography and mass spectrometry were optimized. The 16 flavonoids were separated on a C18 chromatographic column with acetonitrile and water (additional 0.1% formic acid) as mobile phases under gradient elution at a flow rate of 0.25 mL/min. The determination was conducted by tandem mass spectrometry in positive ESI mode under multiple reaction monitoring (MRM) mode. Good linearities for all the compounds, with correlation coefficients over 0.996, were acquired. The recoveries were in the range of 70.9% to 100.0% (n = 6), while the relative standard deviations (RSDs) were less than 10%. The results showed that the nine flavonoids, which were kaempferol, quercetin, hesperitin, vitexin, luteolin, catechin, apigenin, naringenin and isorhamnetin, were higher in contents among the 16 flavonoids in real samples, and they constituted up to 99.6% of the total flavonoids. The contents of these nine flavonoids can be considered as the quality control index of the ginkgo dietary supplement tea. The method proved to be rapid, selective, sensitive and stable, and it can be applied to control the quality of the ginkgo dietary supplement tea.

A novel multiresidue analytical method has been developed and validated for the determination of five classes of veterinary drugs including 18 β-lactams, 15 quinolones, 21 sulfonamides, 3 sulfonamide potentiators and 6 antiparasitics in meat using dispersive solid-phase extraction (dispersive-SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The analytes were extracted with a vortex mixer by 0.1 mol/L Na2 EDTA solution and acetonitrile containing 1% (v/v) acetic acid, and then the extracts were purified using dispersive-SPE with C18 sorbent. Electrospray ionization mass spectrometry was operated in positive mode using dynamic multiple reaction monitoring (DMRM) for the qualitative and quantitative analysis of the 63 analytes after the separation on a Poroshell EC-C18 column (100 mm x 2.1 mm, 2.4 µm). The correlation coefficients of linear calibration curves were over 0.99 in the corresponding concentration ranges. The average recoveries of the 63 analytes ranged from 62.2% to 112.0%, and the relative standard deviations (RSDs) were 3.1%-16.3% in spiked meat (pork, beef and chicken muscle) at three levels. The limits of detection (LODs, S/N ≥ 3) and the limits of quantification (LOQs, S/N ≥ 10) were 0.1-3.0 µg/kg and 0.5-10.0 µg/kg, respectively. The method is simple, rapid, sensitive, reliable and suitable for the determination of residues in animal products.

To explore and evaluate the effect of radio frequency ablation (RFA) in treatment of hepatic VX(2) tumor in rabbits.The hepatoma was treated with RFA in rabbits. The complete necrotic rate of the tumors, pathological changes, CT images and the animals' survival time were observed.(1) ALT in serum increased significantly on the first day and decreased to the control level during 4th-7th day following RFA. (2) On the second week, CT scans showed that complete necrotic foci became larger, and the density of which was asymmetrical. Enhanced CT scans showed no obvious intensification inside; however, ringed intensification appeared along edges of the foci. Biopsy showed that the dark necrotic tissue was surrounded by ringed granulation tissue. Incomplete necrotic tumor foci resembled the complete necrotic foci in no enhanced CT images; however, asymmetrical intensification was observed in enhanced CT scans in the incomplete necrotic foci. Macroscopic observation showed irregular tumor tissue between the necrotic tissue and the peripheral normal tissue. Biopsy showed tumor recurrence in it. (3) Compared with the control, survival time of the animals was longer, and metastases rate in lungs and the fatality rate were lower in the treatment group.RFA, with little injury, is an effective method in the treatment of hepatoma. Enhanced CT scans are consistent with pathological morphometrics of the tumor foci after RFA. The enhanced CT scan is a valuable check-up, which could be used to observe the therapeutic effect after RFA.

Li-rich layered cathode materials Li1.2(Mn0.4Co0.4)O2 with excellent crystal structure and enhanced electrochemical performance were synthesized by a facile compound molten salt method with different molar ratios of mineralizer NaOH to transition metals R (0, 2.5, 5 and 10). The effects of the molar ratio of NaOH to R on the morphology, selective orientation growth, and electrochemical properties of the as-prepared material were investigated through X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge–discharge tests. With the introduction of NaOH into the molten salt reaction system, the crystals grew along the [0001] crystal axis predominantly and the particle morphology changed from hexagonal tablets to columns, which resulted in enhanced electrochemical performance by facilitating Li ion migration. The initial capacity increased from 220 mA h g−1 (R = 0) to 258 mA h g−1 (R = 5), and the capacity retention improved from 70.0% (R = 0) to 89.9% (R = 5) at a current density of 0.1 C after 50 cycles. Furthermore, by using high resolution TEM (HRTEM) and electron energy loss spectroscopy (EELS), the crystal local structure variation and Mn ion valence reduction (Mn4+ to Mn3+) were investigated, which are relevant to the capacity loss after charge–discharge cycling. Our work demonstrated that the prepared particle crystal structure was improved in NaOH flux, and the additional formation of a spinel-like structure was remarkably suppressed during cycling, which contributed to the improved electrochemical properties.

Using comprehensive transmission electron microscopy (TEM) techniques, the associations between the Mn dopant content, microstructure and improved rate performance of LiFe(1−x)MnxPO4 (0 ≤ x ≤ 0.5) were well established. Via the synergistic mechanism including both templating and chelating effects contributed by cetyltrimethyl ammonium bromide (CTAB) and citric acid, a series of LiFe(1−x)MnxPO4 (0 ≤ x ≤ 0.5) olivine crystals with adjustable Mn doping content were synthesized. No impurity phase was detected. Accidentally, a novel type of roughness phenomenon at the particle boundaries of LiFe(1−x)MnxPO4 particles was observed, which depended on citric acid chelation. At the atomic level, the Mn ions were confirmed to be homogeneously substituted at the iron sites, which were furthermore examined by the combined analysis of electron energy loss spectroscopy (EELS), high angle annular dark-field (HAADF) imaging, magnetic susceptibility measurements and X-ray diffraction (XRD). Li/Fe antisite defects were found in the doped LiFe(1−x)MnxPO4 rather than in pure LiFePO4 by HAADF-EELS acquired from a single-atom column at high spatial resolution. The rate performance of LiFe0.9Mn0.1PO4 and LiFe0.8Mn0.2PO4 was improved compared to that of LiFePO4. Our findings might provide new insights into the understanding of Li-ion battery cathode materials with Mn dopant from a microstructural point of view.

The local distribution of old disk neutron stars is approximated with a 1D model, in which the steady state distribution in the direction perpendicular to the Galactic plane is calculated, assuming a variety of the initial radio pulsar positions and velocities, and various Galactic potentials. It is found that the local distribution of old neutron stars is dominated by those that were born with very low velocities. The high-velocity neutron stars spend most of their lifetime far in the Galactic halo and do not contribute much to the local density. Therefore, the rms velocity at birth is not a good indicator of the scale height of the old population. The most likely half-density scale height for the old disk neutron stars is approximately 350 pc, the same as for the old disk G, K, and M stars. If gamma-ray bursts originate on old disk neutron stars, then 350 pc should also be the scale height for the bursters.