Soil carbon dioxide (CO2) efflux of two shrubs in response to plant density in the northern Loess Plateau of China

Although plant density should affect soil carbon dioxide (CO2) efflux and carbon cycling in semi-arid regions, the effects of plant density on soil CO2 efflux are not well known. This study was performed to investigate the responses of soil CO2 efflux of two dominant shrubs (Caragana korshinkii and Salix psammophila) to plant density in the northern Loess Plateau of China. Two plant density treatments, low and high, were included for C. korshinkii (average 20,000 plants ha-1 and average 66,667 plants ha-1) and S. psammophila (average 9,583 plants ha-1 and average 31,250 plants ha-1). Soil CO2 efflux was measured every other day with an Ultra-light portable photosynthesis system (CI-340, CID Inc., USA) from July to October 2009. Soil CO2 efflux with high plant density was significantly larger than that with low plant density for both shrub species. Plant density did not change the temporal pattern of CO2 efflux during the study period. Our results indicated that root biomass and aboveground biomass were the significant biotic factors mediating the response of soil CO2 efflux to plant density for the two shrubs. Moreover, both soil water contents in the 0 - 6 cm soil layer and in deeper soil layer partly regulated the responses of soil CO2 efflux to the shrub density treatments in the semi-arid region.Key words: Plant density, semi-arid, shrub, soil CO2 efflux

Redetermination of 2,4′-methyl­ene­diphenol

In the previous determination [Finn & Musti (1950 ▶). J. Soc. Chem. Ind. (London), 69, S849] of the title compound, C13H12O2, the three-dimensional coordinates and displacement parameters were not reported. This redetermination at room temperature reveals that the dihedral angle between the benzene rings is 79.73 (6)°. In the crystal, inter­molecular O—H⋯O hydrogen bonds between adjacent mol­ecules result in two-dimensional wave-like supra­molecular motifs parallel to the ab plane

Soil carbon dioxide (CO2) efflux of two shrubs in response to plant density in the northern Loess Plateau of China

Although plant density should affect soil carbon dioxide (CO2) efflux and carbon cycling in semi-arid regions, the effects of plant density on soil CO2 efflux are not well known. This study was performed to investigate the responses of soil CO2 efflux of two dominant shrubs (Caragana korshinkii and Salix psammophila) to plant density in the northern Loess Plateau of China. Two plant density treatments, low and high, were included for C. korshinkii (average 20,000 plants ha-1 and average 66,667 plants ha-1) and S. psammophila (average 9,583 plants ha-1 and average 31,250 plants ha-1). Soil CO2 efflux was measured every other day with an Ultra-light portable photosynthesis system (CI-340, CID Inc., USA) from July to October 2009. Soil CO2 efflux with high plant density was significantly larger than that with low plant density for both shrub species. Plant density did not change the temporal pattern of CO2 efflux during the study period. Our results indicated that root biomass and aboveground biomass were the significant biotic factors mediating the response of soil CO2 efflux to plant density for the two shrubs. Moreover, both soil water contents in the 0 - 6 cm soil layer and in deeper soil layer partly regulated the responses of soil CO2 efflux to the shrub density treatments in the semi-arid region

Effects of aminoguanidine on retinal apoptosis in mice with oxygen-induced retinopathy

<b>AIM:</b> To explore the protective effects of aminoguanidine (AG) on retinal apoptosis in mice with oxygen-induced retinopathy (OIR).<b>METHODS</b>:A total of 80 C57BL/6J mice, aged 7 days, were randomly divided into four groups:normal, high oxygen, high oxygen saline and high oxygen treated with AG. In the normal group, mice were housed in normoxic conditions from postnatal day P7 to P17. Mice in the other 3 groups were placed under hyperoxic conditions (75±2%O2) in an oxygen-regulated chamber for 5 days and subsequently placed in normoxic conditions for 5 days. Mice in the AG group were treated once daily, from P12 to P17, with AG hemisulfate (100mg/kg body weight, intraperitoneally) dissolved in physiological saline. An equivalent amount of 0.9% physiological saline was administered, as above, to mice in the high oxygen saline group. Ten mice were randomly selected from each group on P14 and on P17, euthanized and the retinas examined. Apoptotic cells in the retina were detected using the terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method. The expression of nitric oxide synthase (iNOS) in the retina was detected by immunohistochemistry and changes in rod cells were observed using electron microscopy.<b>RESULTS</b>:TUNEL-positive cells and iNOS immunoreactive neurons were present in the inner nuclear and ganglion cell retinal layers of mice in the high oxygen group. The number of TUNEL-positive cells was significantly greater in the high oxygen group compared with the normal group (<i>t</i>=-20.81, <i>P</i>14d <0.05; <i>t</i>=-15.05, <i>P</i>17d<0.05). However, the number of TUNEL-positive cells in the AG treatment group was significantly lower (<i>t</i>=-13.21, <i>P</i>14d<0.05; <i>t</i>=-6.61,<i>P</i>17d <0.05) compared with the high oxygen group. The expression of iNOS was significantly higher in the high oxygen group compared with the normal group (<i>t</i>=-21.95, <i>P</i>14d<0.05; <i>t</i>=-17.30, <i>P</i>17d<0.05). However, the expression of iNOS in the AG treatment group was significantly lower (<i>t</i>=-12.17,<i>P</i>14d<0.05; <i>t</i>=-10.30,<i>P</i>17d<0.05) compared with the high oxygen group. The outer segments of the rods were disorganized and short in the high oxygen group. Rod morphology appeared to be slightly improved in the AG group.<b>CONCLUSION</b>:AG may protect retinal neurons in OIR by inhibiting apoptosis. The mechanism may be related to iNOS

In vitro antioksidacijska, citotoksična i antidijabetička aktivnost hidrolizata proteina iz Reevesove barske kornjače (Chinemys reevesii)

Research background. Cardiovascular diseases and diabetes are the biggest causes of death globally. Bioactive peptides derived from many food proteins using enzymatic proteolysis and food processing have a positive impact on the prevention of these diseases. The bioactivity of Chinese pond turtle muscle proteins and their enzymatic hydrolysates has not received much attention, thus this study aims to investigate their antioxidant, antidiabetic and cytotoxic activities. Experimental approach. Chinese pond turtle muscles were hydrolysed using four proteolytic enzymes (Alcalase, Flavourzyme, trypsin and bromelain) and the degrees of hydrolysis were measured. High-performance liquid chromatography (HPLC) was conducted to explore the amino acid profiles and molecular mass distribution of the hydrolysates. The antioxidant activities were evaluated using various in vitro tests, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), hydroxyl radical scavenging activity, reducing capacity, chelating Fe2+ and lipid peroxide inhibition activity. Antidiabetic activity was evaluated using α-amylase inhibition and α-glucosidase inhibition assays. Besides, cytotoxic effect of hydrolysates on human colon cancer (HT-29) cells was assessed. Results and conclusions. The amino acid composition of the hydrolysates revealed higher mass fractions of glutamic, aspartic, lysine, hydroxyproline and hydrophobic amino acids. Significantly highest inhibition of lipid peroxidation was achieved when hydrolysate obtained with Alcalase was used. Protein hydrolysate produced with Flavourzyme had the highest radical scavenging activity measured by DPPH (68.32%), ABTS (74.12%) and FRAP (A700 nm=0.300) assays, α-glucosidase (61.80%) inhibition and cytotoxic effect (82.26%) on HT-29 cell line at 550 µg/mL. Hydrolysates obtained with trypsin and bromelain had significantly highest (p<0.05) hydroxyl radical scavenging (92.70%) and Fe2+ metal chelating (63.29%) activities, respectively. The highest α-amylase (76.89%) inhibition was recorded when using hydrolysates obtained with bromelain and Flavourzyme. Novelty and scientific contribution. Enzymatic hydrolysates of Chinese pond turtle muscle protein had high antioxidant, cytotoxic and antidiabetic activities. The findings of this study indicated that the bioactive hydrolysates or peptides from Chinese pond turtle muscle protein can be potential ingredients in pharmaceuticals and functional food formulations.Pozadina istraživanja. Kardiovaskularne bolesti i dijabetes najčešći su uzroci smrti na svijetu. Bioaktivni peptidi dobiveni proteolizom i preradom hrane imaju pozitivan učinak na prevenciju tih bolesti. Biološka aktivnost proteina iz mišića Reevesove barske kornjače i njihovih hidrolizata nije dovoljno istražena, stoga je svrha ovoga rada bila ispitati njihovu antioksidacijsku, antidijabetičku i citotoksičnu aktivnost. Eksperimentalni pristup. Mišići Reevesove barske kornjače hidrolizirani su pomoću proteolitičkih enzima (Alcalase, Flavourzyme, tripsin i bromelain), te su mjereni stupnjevi hidrolize proteina. Aminokiselinski sastav i distribucija molekularne mase hidrolizata ispitani su pomoću visokodjelotvorne tekućinske kromatografije. Antioksidacijska aktivnost određena je različitim testovima in vitro, uključujući sposobnost uklanjanja 1,1-difenil-2-pikrilhidrazila (DPPH), 2,2’-azino-bis(3-etilbenzotiazolin-6-sumporne kiseline) (ABTS) i hidroksil radikala, keliranja Fe2+ i inhibicije lipidne peroksidacije. Antidijabetička aktivnost ispitana je testovima inhibicije α-amilaze i α-glukozidaze. Osim toga, analiziran je citotoksični učinak hidrolizata na stanice tumora debelog crijeva (HT-29). Rezultati i zaključci. Analizom aminokiselinskog sastava hidrolizata pronađeni su veći maseni udjeli glutaminske i asparaginske kiseline, lizina, hidroksiprolina te hidrofobnih aminokiselina od onih u nehidroliziranim proteinima. Hidrolizat proteina dobiven pomoću proteolitičkog enzima Alcalase bitno je inhibirao peroksidaciju lipida. Pri koncentraciji od 550 µg/mL, hidrolizat proteina dobiven pomoću enzima Flavourzyme imao je najveću sposobnost uklanjanja slobodnih radikala mjerenu pomoću DPPH (68,32 %), ABTS (74,12 %) i FRAP (A700 nm=0,300) metoda, inhibicije α-glukozidaze (61,80 %) te najveći citotoksični učinak na stanične linije HT-29 (82.26 %). Hidrolizat proteina dobiven pomoću tripsina imao je znatnu (p<0,05) aktivnost uklanjanja hidroksilnih radikala (92,70 %), a onaj dobiven pomoću bromelaina najveću aktivnost keliranja Fe2+ (63,29 %). Najveća inhibicija α-amilaze postignuta je pomoću hidrolizata proteina dobivenih djelovanjem bromelaina i enzima Flavourzyme. Novina i znanstveni doprinos. Hidrolizati proteina mišića Reevesove barske kornjače dobiveni enzimskom hidrolizom imali su veliku antioksidacijsku, citotoksičnu i antidijabetičku aktivnost. Rezultati istraživanja pokazuju da se ti hidrolizati ili peptidi zbog svojih bioaktivnih svojstava mogu upotrijebiti kao sastojak u farmaceutskim i funkcionalnim prehrambenim proizvodima

Extensive tRNA gene changes in synthetic Brassica napus

Allopolyploidization, where two species come together to form a new species, plays a major role in speciation and genome evolution. Transfer RNAs (abbreviated tRNA) are typically 73-94 nucleotides in length, and are indispensable in protein synthesis, transferring amino acids to the cell protein synthesis machinery (ribosome). To date, the regularity and function of tRNA gene sequence variation during the process of allopolyploidization have not been well understood. In this study, the inter-tRNA gene corresponding to tRNA amplification polymorphism method was used to detect changes in tRNA gene sequences in the progeny of interspecific hybrids between Brassica rapa and B. oleracea, mimicking the original B. napus (canola) species formation event. Cluster analysis showed that tRNA gene variation during allopolyploidization did not appear to have a genotypic basis. Significant variation occurred in the early generations of synthetic B. napus (F and F generations), but fewer alterations were observed in the later generation (F). The variation-prone tRNA genes tended to be located in AT-rich regions. BlastN analysis of novel tRNA gene variants against a Brassica genome sequence database showed that the variation of these tRNA-gene-associated sequences in allopolyploidization might result in variation of gene structure and function, e.g., metabolic process and transport

Dynamic expression of cytokine and transcription factor genes during experimental Fasciola gigantica infection in buffaloes

Background Determining the mechanisms involved in the immune-pathogenesis of the tropical liver fluke, Fasciola gigantica, is crucial to the development of any effective therapeutic intervention. Here, we examined the differential gene expression of cytokines and transcription factors in the liver of F. gigantica-infected buffaloes, over the course of infection. Methods Water buffaloes (swamp type) were infected orally with 500 F. gigantica encysted metacercariae. Liver tissue samples were collected 3, 10, 28, 42, 70 and 98 days post-infection (dpi). Levels of gene expression of nine cytokines (IFN-γ, TGF-β, IL-1β, IL-4, IL-6, IL-10, IL-12B, IL-13 and IL-17A) and four transcription factors (T-bet, GATA-3, Foxp3 and ROR-γτ) were determined using quantitative real-time PCR (qRT-PCR). We evaluated any correlation between gene expression of these immune-regulatory factors and the severity of liver pathology. Results Histopathological examination revealed that cellular infiltration, hemorrhage and fibrosis without calcification in the liver parenchyma of infected buffaloes, increased over the course of infection. This progressive pathology was attributed to dysregulated and excessive inflammatory responses induced by infection. The early infection phase (3–10 dpi) was marked by a generalized immunosuppression and elevated TGF-β expression in order to facilitate parasite colonization. A mixed Th1/Th2 immune response was dominant from 28 to 70 dpi, to promote parasite survival while minimizing host tissue damage. During late infection (98 dpi), the response was biased towards Th1/Treg in order to inhibit the host’s Th2 protective response and promote chronic infection. Both IL-10 and IL-17A and the Th17/Treg balance, played key roles in mediating the inflammatory and immunoregulatory mechanisms in the liver during chronic fasciolosis. Conclusions Our data showed distinct CD4+ T helper (Th) polarization and cytokine dysregulation in response to F. gigantica infection in water buffaloes over the course of infection. Characterizing the temporal expression profiles for host immune genes during infection should provide important information for defining how F. gigantica adapts and survives in the liver of buffaloes and how host immune responses influence F. gigantica pathogenicity