523 research outputs found
3-Amino-4,6-dimethylthieno[2,3-b]pyridine-2-carbonitrile
The molecule of the title compound, C10H9N3S, is almost planar, with a dihedral angle of 1.38 (4)° between the thiophene and pyridine rings. In the crystal packing, molecules are linked into layers parallel to the ab plane by intermolecular N—H⋯N hydrogen bonds and by π⋯π stacking interactions involving adjacent pyridine and thiophene rings with a centroid–centroid distance of 3.537 (3) Å
Tyrosine phosphorylation of HPK1 by activated Src promotes ischemic brain injury in rat hippocampal CA1 region
AbstractHematopoietic progenitor kinase 1 (HPK1) is a hematopoietic cell-restricted member of the Ste20 serine/threonine kinase super family. We recently reported that HPK1 is involved in c-Jun NH2-terminal kinase (JNK) signaling pathway by sequential activation of MLK3–MKK7–JNK3 after cerebral ischemia. Here, we used 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo [3,4-d] pyrimidine (PP2) and MK801 to investigate the events upstream of HPK1 in ischemic brain injury. Immunoprecipitation and immunoblot results showed that PP2 and MK801 significantly decreased the activation of Src, HPK1, MLK3, JNK3 and c-Jun, respectively, during ischemia/reperfusion. Histology and TUNEL staining showed PP2 or MK801 protects against neuron death after brain ischemia. We speculate that this unique signaling pathway through the tyrosine phosphorylation of HPK1 promotes ischemic brain injury by activated Src via N-methyl-d-aspartate receptor and, ultimately, the activation of the MLK3–MKK7–JNK3 pathway after cerebral ischemia
Multi-axis fatigue loading system of wind turbine blade and vibration coupling characteristics
This paper presents a new method which focuses on the multi-axis fatigue loading mode for wind turbine blade and aims to shorten the fatigue loading cycle. The whole test scheme is design for the measurement of fatigue loading system. The two leading sources of fatigue loading system are asymmetric arrangement in the space. In addition, its vibration mathematical model is derived according to the Lagrange equation. The numerical simulation model is developed by means of Matlab Simulink. The vibration coupling characteristics including motor revolution speed, phase and amplitude of wind turbine blade is obtained. Moreover, the trajectory of wind turbine blade is obtained. Finally, a multi-axis fatigue loading platform for small wind turbine blade is built for the proposed study. The on-site test showed that if the revolution speeds of the two loading sources is the same as the natural frequency of wind turbine blade, the revolution speed, the phase angle of motor and the blade trajectory were relative changed smoothly. Thus, the amplitude of blade is state and the largest. Otherwise when the revolution speed of motor is different with the natural frequency of blade, the revolution speeds and phase angle of the two loading sources fluctuated largely. The above conclusion provided the theoretical basis for the subsequent decoupling control algorithm of multi-axis fatigue loading test
RHΔgra17Δnpt1 strain of Toxoplasma gondii elicits protective immunity against acute, chronic and congenital toxoplasmosis in mice
In the present study, a dense granule protein 17 (gra17) and novel putative transporter (npt1) double deletion mutant of Toxoplasma gondii RH strain was engineered. The protective efficacy of vaccination using RHΔgra17Δnpt1 tachyzoites against acute, chronic, and congenital toxoplasmosis was studied in a mouse model. Immunization using RHΔgra17Δnpt1 induced a strong humoral and cellular response, as indicated by the increased levels of anti-T. gondii specific IgG, interleukin 2 (IL-2), IL-10, IL-12, and interferon-gamma (IFN-γ). Vaccinated mice were protected against a lethal challenge dose (103 tachyzoites) of wild-type homologous (RH) strain and heterologous (PYS and TgC7) strains, as well as against 100 tissue cysts or oocysts of Pru strain. Vaccination also conferred protection against chronic infection with 10 tissue cysts or oocysts of Pru strain, where the numbers of brain cysts in the vaccinated mice were significantly reduced compared to those detected in the control (unvaccinated + infected) mice. In addition, vaccination protected against congenital infection with 10 T. gondii Pru oocysts (administered orally on day 5 of gestation) as shown by the increased litter size, survival rate and the bodyweight of pups born to vaccinated dams compared to those born to unvaccinated + infected dams. The brain cyst burden of vaccinated dams was significantly lower than that of unvaccinated dams infected with oocysts. Our data show that T. gondii RHΔgra17Δnpt1 mutant strain can protect mice against acute, chronic, and congenital toxoplasmosis by balancing inflammatory response with immunogenicity
(S,R,Rp)-N,N-Dimethyl-1-{2-[(1-phenylethyl)aminomethyl]ferrocenyl}ethanamine
The title chiral ferrocene compound, [Fe(C5H5)(C18H25N2)], contains one planar and two central chiral centers. It is of interest with respect to asymmetric catalysis. The absolute configuration of the planar chirality is Rp at the ferrocene group and those of the two C chiral centers are R at the CH carbon of the ethanamine unit and S at the CH carbon of the phenylethylamino substituent. In the ferrocenyl unit, the cyclopentadienyl (Cp) rings are planar, with maximum deviations of 0.002 (2) Å for the substituted and 0.008 (3) Å for the unsubstituted Cp ring. The dihedral angle between the ring planes is 2.12 (15)° and the rings are twisted slightly from an eclipsed conformation by 7.06–7.60°
Isolation of deoxynivalenol-transforming bacteria from the chicken intestines using the approach of PCR-DGGE guided microbial selection
<p>Abstract</p> <p>Background</p> <p>Contamination of grains with trichothecene mycotoxins, especially deoxynivalenol (DON), has been an ongoing problem for Canada and many other countries. Mycotoxin contamination creates food safety risks, reduces grain market values, threatens livestock industries, and limits agricultural produce exports. DON is a secondary metabolite produced by some <it>Fusarium </it>species of fungi. To date, there is a lack of effective and economical methods to significantly reduce the levels of trichothecene mycotoxins in food and feed, including the efforts to breed <it>Fusarium </it>pathogen-resistant crops and chemical/physical treatments to remove the mycotoxins. Biological approaches, such as the use of microorganisms to convert the toxins to non- or less toxic compounds, have become a preferred choice recently due to their high specificity, efficacy, and environmental soundness. However, such approaches are often limited by the availability of microbial agents with the ability to detoxify the mycotoxins. In the present study, an approach with PCR-DGGE guided microbial selection was developed and used to isolate DON -transforming bacteria from chicken intestines, which resulted in the successful isolation of several bacterial isolates that demonstrated the function to transform DON to its de-epoxy form, deepoxy-4-deoxynivalenol (DOM-1), a product much less toxic than DON.</p> <p>Results</p> <p>The use of conventional microbiological selection strategies guided by PCR-DGGE (denaturing gradient gel electrophoresis) bacterial profiles for isolating DON-transforming bacteria has significantly increased the efficiency of the bacterial selection. Ten isolates were identified and isolated from chicken intestines. They were all able to transform DON to DOM-1. Most isolates were potent in transforming DON and the activity was stable during subculturing. Sequence data of partial 16S rRNA genes indicate that the ten isolates belong to four different bacterial groups, Clostridiales, <it>Anaerofilum</it>, <it>Collinsella</it>, and <it>Bacillus</it>.</p> <p>Conclusions</p> <p>The approach with PCR-DGGE guided microbial selection was effective in isolating DON-transforming bacteria and the obtained bacterial isolates were able to transform DON.</p
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