220 research outputs found
Mean Field Effects In The Quark-Gluon Plasma
A transport model based on the mean free path approach for an interacting
meson system at finite temperatures is discussed. A transition to a quark gluon
plasma is included within the framework of the MIT bag model. The results
obtained compare very well with Lattice QCD calculations when we include a mean
field in the QGP phase due to the Debye color screening. In particular the
cross over to the QGP at about 175 MeV temperature is nicely reproduced. We
also discuss a possible scenario for hadronization which is especially
important for temperatures below the QGP phase transition
Toxicological evaluation of precocene II isolated from Ageratum conyzoides L. (Asteraceae) in Sprague Dawley rats
Precocene II (6,7-dimethoxy-2,2-dimethyl-2-chromene) was the main constituent isolated from Ageratum
conyzoides L. and reportedly possessed antifungal activity. The study investigated the isolation,
purification and toxicological effects of precocene II from A. conyzoides in Sprague Dawley rats.
Precocene II was isolated from the petroleum ether fraction of the plant and the structure was
determined by 1H-,13C-,DEPT-NMR and MS spectral techniques. Three groups of eight rats per group
were used for the study. While groups B and C were respectively administered with 25 and 50 mg/kg of
precocene II in 0.25% CMC-Na for 11 days by gastric intubation, group A was administered with 0.25%
CMC-Na and served as the control group. After the last treatment, animals were fasted overnight and on
the 12th day, they were injected intravenously with 0.2 ml/kg body weight of phenobarbital. Animals
were subsequently dissected from the abdominal region; blood was collected from the pulmonary vein
into EDTA anti-coagulated and non anti-coagulated tubes. The liver, kidney and spleen tissues were
extracted into separate bottles for histopathological examinations. Results from hematological study
indicated that the white blood cell (WBC), red blood cell (RBC), plateletcrit (PCT) and mean corpuscular hemoglobin count (MCHC) were significantly higher across the treated groups. Biochemical result showed that serum glucose level was significantly reduced in the treated groups. No apparent damage was noticed in the liver, kidney and spleen tissues. The result therefore suggests that precocene II
possesses hypoglycemic property and could alter some hematopoietic elements but was not toxic to the liver, kidney and spleen tissues
A new norlignan from Taxodium ascendens
A new norlignan, (2R,3R,4S,5S)-2,4-bis(4-hydroxyphenyl)-3,5-dihydroxy-tetrahydropyran (1),
together with 9 known compounds were isolated from the branches and leaves of Taxodium
ascendens. Their structures were mainly determined on the basis of MS, IR, 1D and 2D NMR
spectral evidences. Methanol extract showed inhibitory activity on carbonic anhydrase II with
an IC50 value of 4.27 μg/ml, acetone extract and methanol extract inhibited activity of cathepsin
B with IC50 values of 2.12 and 3.71 μg/ml, respectively.
Kinetic description of hadron-hadron collisions
A transport model based on the mean free path approach to describe pp
collisions is proposed. We assume that hadrons can be treated as bags of
partons similarly to the MIT bag model. When the energy density in the
collision is higher than a critical value, the bags break and partons are
liberated. The partons expand and can make coalescence to form new hadrons. The
results obtained compare very well with available data and some prediction for
higher energies collisions are discussed. Based on the model we suggest that a
QGP could already be formed in the pp collisions at high energies
13c-(2-Chloroethoxy)-1,13c-dihydro-2,3-epoxydibenzo[a,kl]xanthan-1-one
The title compound, C22H15ClO4, containing three chiral C atoms, is an intermediate in the design of chiral alcohols. In the crystal structure, a chain structure is generated through C—H⋯O contacts and an intramolecular C—H⋯O interaction also occurs. The dihedral angle between the benzene ring and the naphthalene system is 16.5°
Identification of 10 SUMOylation-Related Genes From Yellow Catfish Pelteobagrus fulvidraco, and Their Transcriptional Responses to Carbohydrate Addition in vivo and in vitro
SUMOylation is a kind of important post-translational modification. In the present study, we identified 10 key genes involved in SUMOylation and deSUMOylation (sumo1, sumo2, sumo3, sae1, uba2, ubc9, pias1, senp1, senp2, and senp3) in yellow catfish Pelteobagrus fulvidraco, investigated their tissue expression patterns and transcriptional responses to carbohydrate addition both in vivo and in vitro. All of these members shared similar domains to their orthologous genes of other vertebrates. Their mRNAs were widely expressed in all the tested tissues, but at variable levels. Dietary carbohydrate levels differentially influenced the mRNA levels of these genes in liver, muscle, testis, and ovary of yellow catfish. Their mRNA levels in primary hepatocytes were differentially responsive to glucose addition. Our study would contribute to our understanding into the molecular basis of SUMOylation modification and into the potential SUMOylation function in the carbohydrate utilization in fish
Biochemical, haematological and histopathological studies of extract of Ageratum conyzoides L. in Sprague Dawley rats
This study was conducted to evaluate the safety potential of the leaf extract of Ageratum conyzoides Linnaeus in Sprague Dawley (SD) rats using biochemical, haematological and histological indices of toxicity. Four groups of seven male SD rats per group were used for the study. To group A was administered 0.25% CMC-Na/ kg body weight and was used as the control group, while groups B, C and D were respectively administered with 500, 1000 and 1500 mg/kg body weight of the ethanolic leaf extract of A. conyzoides by gastric intubation for 14 days. Animals were subsequently anaesthetized, blood samples were collected for biochemical and haematological assays; organs were isolated and weighed, while the liver, kidney and spleen were processed for histopathological studies. Aspartate
amino transferase, lactate dehydrogenase, creatine kinase and alkaline phosphatase were significantly (p < 0.05) reduced in the groups treated with 1000 and 1500 mg/kg body weight of the extract. Furthermore, there was a significant (p < 0.05) elevation in white blood cell count, mean platelet volume and % platelet distribution width. Histopathological studies indicated various degrees of hepatocellular necrosis in all the treated groups accompanied by significant increases in the weight of liver and spleen. The results showed that the ethanolic leaf extract of A. conyzoides significantly alters the
biomarkers of cardiac and skeletal muscle disorders, and higher doses could induce liver cell injury
Oxyphyllones A and B, novel sesquiterpenes with an unusual 4,5-secoeudesmane skeleton from Alpinia oxyphylla
Two novel 4,5-secoeudesmane sesquiterpenoids, oxyphyllones A (1) and B (2) were isolated from the fruits of Alpinia
oxyphylla. Their structures were established by spectroscopic methods including 1D and 2D NMR spectra. These two compounds
are the first example of naturally occurring sesquiterpenoids with a 4,5-secoeudesmane skeleton in the family of Zingiberaceae and
oxyphyllone A (1) is the first 4,5-secoeudesmane type of 13-norsesquiterpenoid. Compounds 1 and 2 exhibited no cytotoxicities
against three cancer cell lines at 10 mg/mL
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