[Discrimination of Lactarius and Russula Mushrooms with FTIR and Two-Dimensional Correlation Infrared Spectroscopy].

Tri-step infrared spectroscopy method of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy was firstly used to discriminate six species of mushrooms belonging to the genus Lactarius and Russula. The absorption bands of the original spectrum were very similar, which were composed by protein and polysaccharides, but tiny differences were observed at the position, shape and absorption intensities of peaks. Second derivative infrared spectroscopy technology was applied to study 6 species of the samples, there were obvious differences in the range of 1 800～1 400 and 1 200～800 cm-1. Two-dimensional correlation infrared spectroscopy can improve the resolution of spectra. Therefore two-dimensional correlation infrared spectroscopy was used to study 6 kinds of mushrooms. The results showed that there are three auto-peaks in the Lactarius, four in the Russula and significant differences in the number, intensity of auto-peaks and cross peaks were observed in the range of 1 690~1 420 cm-1. In addition, the peaks quantity, position, intensity of auto-peaks and cross peaks were different in the range of 1 110~920 cm-1. It demonstrates that tri-step infrared spectroscopy technology of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy is a rapid and effective method for discriminating Lactarius and Russula.

[Discrimination of Seven Species of Boletus with Fourier Transform Infrared Spectroscopy].

Fourier transform infrared spectroscopy, two-dimensional correlation infrared spectroscopy and principal component analysis were used to discriminate seven species of boletus belonging to the same genus. The results showed that the absorption bands of original spectra were similar, which were mainly composed of the absorption bands of protein and polysaccharides, but tiny differences were still observed at the position and intensities of peaks. Two-dimensional correlation infrared spectroscopy technology was applied to study the sample. It showed that there are 6 auto-peaks in the Boletus brunneissimus Chiu and Boletus bicolor, 5 auto-peaks in the Boletus speciosus, 4 auto-peaks in the Boletus griseus Forst and Boletus calopus, only 3 in the Boletus edulis and Boletus aereus in the range of 1 680~1 300 cm-1. The significant differences in the position, intensity of auto-peaks and cross peaks were still observed in the range of 1 680~1 300 cm-1. Same significant differences were observed in the range of 1 150~920 cm-1. Principal component analysis was conducted on boletus with second derivative infrared spectra in the range of 1 800~800 cm-1. All the samples were distinguished and the classification accuracy of principal component analysis is up to 100%. It is demonstrated that Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy or principal component analysis is a rapid and effective method for discriminating mushrooms.

[Effect of degradation succession process on the temperature sensitivity of ecosystem respiration in alpine Potentilla fruticosa scrub meadow].

Grazing is one of the main artificial driving forces for the degradation succession process of alpine meadow. In order to quantitatively study the temperature sensitivity of alpine meadow ecosystem respiration in different degradation stages, we conducted the research in Haibei Alpine Meadow Ecosystem Research Station, CAS from July 2003 to July 2004. The static chamber-chromatography methodology was used to observe the seasonal changes of alpine scrub ecosystem respiration flux during different degradation stages. The results showed that: (1) The seasonal changes of ecosystem respiration flux in different degradation stages of alpine shrub presented a unimodal curve. The maximum appeared in August and the minimum appeared during the period from October to next April. The degradation succession process significantly decreased the ecosystem respiratory CO2 release rate. The respiratory rate ranges of alpine Potentilla fruticosa scrub (GG), Kobresia capillifolia meadow (GC) and bare land (GL) were 34.21-1 168.23, 2.30-1 112.38 and 20.40-509.72 mg (m2 x h)(-1), respectively. The average respiration rate of GG was 1.29 and 2.56 times of that of GC and GL, respectively; (2) Temperature was the main factor that affected the ecosystem respiration rate, and contributed 25% - 79% of the variation of the ecosystem respiration. The degradation succession process significantly changed the correlation between ecosystem respiration rate and temperature. The correlation (R2) between ecosystem respiration rate and each temperature indicator (T(s), T(d) and T(a)) was reduced by 47.23%, 46.95% and 55.28%, respectively when the ground vegetation disappeared and the scrub was degraded into secondary bare land; (3) The difference of Q10 between warm and cool seasons was significant (P < 0.05), and the value of cold season was larger than that of warm season. Degradation succession process apparently changed the temperature sensitivity of ecosystem respiration. The Q10 values of GG, GC and GL were 2.38, 2.91 and 1.62, respectively. Q10 of GC was increased by 22.26% and that of GL was decreased by 31.93% compared with that of GG.

Preparation of polydopamine nanocapsules in a miscible tetrahydrofuran-buffer mixture.

A miscible tetrahydrofuran-tris buffer mixture has been used to fabricate polydopamine hollow capsules with a size of 200 nm and with a shell thickness of 40 nm. An unusual non-emulsion soft template mechanism has been disclosed to explain the formation of capsules. The results indicate that the capsule structure is highly dependent on the volume fraction of tetrahydrofuran as well as the solvent, and the shell thickness of capsules can be controlled by adjusting the reaction time and dopamine concentration.

Role of G protein-coupled estrogen receptor 1 in modulating transforming growth factor-ß stimulated mesangial cell extracellular matrix synthesis and migration.

Estrogen has been demonstrated to exert beneficial effects on kidney; however, the role of G protein-coupled estrogen receptor 1 (GPER) is still uncertain. In the present study, we investigated the effect of 17ß-estradiol and GPER agonist Fulvestrant on extracellular matrix production under transforming growth factor-ß1 (TGF-ß1) stimulation in human and rat mesangial cells. As a result, 17ß-estradiol and Fulvestrant inhibit TGF-ß1-induced type IV collagen and fibronectin expression in a dose-dependent manner, by suppressing acute Smad2/3 phosphorylation and Smad4 complex formation. Furthermore, estrogen and Fulvestrant also down-regulate Smad signaling by promoting ubiquitin/proteasome-dependent Smad2 degradation. These effects could be abrogated by receptor antagonist G-15 or GPER gene knockdown. GPER is also required for estrogen and Fulvestrant to regulate mesangial cell migration in response to TGF-ß1. To conclude, GPER is crucial in modulating glomerular mesangial cell function including extracellular matrix production and migration.

Icariin attenuates high glucose-induced type IV collagen and fibronectin accumulation in glomerular mesangial cells by inhibiting transforming growth factor-ß production and signalling through G protein-coupled oestrogen receptor 1.

Icariin has been shown to attenuate diabetic nephropathy in rats by decreasing transforming growth factor-ß (TGF-ß) and type IV collagen expression, but its mode of action in glomerular mesangial cells is uncertain. The present study aimed to investigate the effect of icariin on excess mesangial type IV collagen and fibronectin accumulation induced by high glucose, and to determine the mechanism underlying its protective effects. Under high-glucose conditions, icariin diminished type IV collagen and fibronectin accumulation, as well as TGF-ß production in human and rat mesangial cells. Mesangial cells treated with icariin after TGF-ß1 exposure expressed less type IV collagen and fibronectin than those without icariin treatment, suggesting inhibition by icariin of TGF-ß1 downstream pathways. On TGF-ß1 stimulation, icariin inhibited TGF-ß canonical Smad signalling and extracellular signal-regulated kinase (ERK)1/2 signalling by decreasing Smad2/3 and ERK1/2 phosphorylation in a dose-dependent manner. U0126, which blocked the ERK1/2 pathway, exerted an additive effect on the icariin suppression of type IV collagen and fibronectin expression, enhancing the beneficial effects of icariin. The G protein-coupled oestrogen receptor 1 (GPER) antagonist, G-15, abolished the icariin-induced inhibition of type IV collagen, and fibronectin overproduction and TGF-ß signalling. Treatment of cells with fulvestrant, a downregulator of the oestrogen receptor, enhanced the action of icariin. In conclusion, icariin decreased type IV collagen and fibronectin accumulation induced by high glucose in mesangial cells by inhibiting TGF-ß production, as well as Smad and ERK signalling in a GPER-dependent manner.

[The responses of photosynthesis to strong light in the medicinal plants Anisodus tanguticus (Maxim.) Pascher and Rheum tanguticum Maxim. on the Qinghai-Tibet Plateau].

Photosynthetic electron transport and light energy allocation were studied in the alpine plants Anisodus tanguticus (Maxim.) Pascher and Rheum tanguticum Maxim. ex Balf on the Qinghai-Tibet Plateau by using gas exchange and chlorophyll fluorescence. The results indicated that apparent quantum yield (AQY) of leaves of A. tanguticus was marginally higher than that of R. tanguticum although it had a lower maximum net photosynthetic rate (Pmax). The net photosynthetic rate (P(n)) of A. tanguticus was higher than R. tanguticum within the range of middle photosynthetic photon flux density (PPFD). However, the P(n) in R. tanguticum increased concomitantly with PPFD and did not appear to show light saturation of P(n) even under 2000 micromol m(-2) s(-1) which is similar to full light in summer (Fig.1). Increasing the PPFD to 1200 micromol m(-2) s(-1) decreased the ratio of carboxylation rate to total photosynthetic electron flow rate (J(C)/J(F)) although increased the ratio of photorespiration (J(O)/J(F)) for both species. Both J(C)/J(F) and J(O)/J(F) stabilized with a PPFD of more than 1200 micromol m(-2) s(-1) (Fig.2). The changes in the ratios of Rubisco oxygenation to carboxylation (V(O)/V(C)) were similar to changes to J(O)/J(F) (Fig.3). The increase of thermal energy dissipation (D) in A. tanguticus was higher than R. tanguticum with increased PPFD (Fig.4). It can be concluded that the two species adopt different mechanisms to cope with increased solar radiation. Increasing the fractions of PSII thermal energy dissipation and electron transport through photorespiration were the main adaptations in A. tanguticus. Enhancement of photosynthetic capacity with increased PPFD to balance the higher light energy absorbed by leaves is considered the main adaptation for R. tanguticum.