Malaysian tualang honey possesses strong antioxidant and anti‐inflammatory properties. Here, we evaluated the effect of tualang honey on early biomarkers of photocarcinogenesis employing PAM212 mouse keratinocyte cell line. Keratinocytes were treated with tualang honey (1.0%, v/v) before a single UVB (150 mJ cm?2) irradiation. We found that the treatment of tualang honey inhibited UVB‐induced DNA damage, and enhanced repair of UVB‐mediated formation of cyclobutane pyrimidine dimers and 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine. Treatment of tualang honey inhibited UVB‐induced nuclear translocation of NF‐κB and degradation of IκBα in murine keratinocyte cell line. The treatment of tualang honey also inhibited UVB‐induced inflammatory cytokines and inducible nitric oxide synthase protein expression. Furthermore, the treatment of tualang honey inhibited UVB‐induced COX‐2 expression and PGE2 production. Taken together, we provide evidence that the treatment of tualang honey to keratinocytes affords substantial protection from the adverse effects of UVB radiation via modulation in early biomarkers of photocarcinogenesis and provide suggestion for its photochemopreventive potential. 相似文献
Complexes [Sb(2Ac4oClPh)Cl2] (1), [Sb(2Ac4oFPh)Cl2] (2), [Sb(2Ac4oNO2Ph)Cl2] (3), [Sb(2Bz4oClPh)Cl2] (4), [Sb(2Bz4oFPh)Cl2] (5) and [Sb(2Bz4oNO2Ph)Cl2] (6) were obtained with 2-acetylpyridine-N(4)-ortho-chlorophenyl thiosemicarbazone (H2Ac4oClPh) and its N(4)-ortho-fluor (H2Ac4oFPh) and N(4)-ortho-nitro (H2Ac4oNO2Ph) analogues, and with the corresponding 2-benzoylpyridine-derived thiosemicarbazones (H2Bz4oClPh, H2Bz4oFPh, H2Bz4oNO2Ph). The studied compounds are excellent inhibitors of Trypanosoma cruzi growth. H2Bz4oClPh and complexes (4) and (1) were the most trypanosomicidal.Upon coordination of H2Ac4oClPh to antimony(III) in 1, the therapeutic index (TI) goes from 10.58 to 14.35. However, the best values of TI were found for H2Bz4oClPh (TI = 1240) and H2Ac4oNO2Ph (TI = 773). Structure-activity relationship (SAR) studies did not allow the establishment of correlations between the anti-trypanosomal activity and physico-chemical parameters, but correlations were found between the cytotoxicities and physico-chemical properties. 相似文献
We discuss the problem whether the time evolution in quantum physics should be represented by the time-symmetric unitary-group evolution, i.e., whether time t extends over???∞?<?t?<?+∞ or it is more realistic to describe quantum systems by a mathematical theory, for which time t starts from a finite value t0: t0?≤?t?<?+∞, for which the mathematicians would choose t0?=?0,1 but which could be any finite value. If the quantum system in the lab should be described by some kind of quantum theory, one should also admit the possibility that the solution of the dynamical equations needs to be found under boundary conditions that admit a semigroup evolution. It is remarkable that results in lab experiments indicate the existence of an ensemble of finite beginnings of time $ t_0^{(i) } $ for an ensemble of individual quanta. 相似文献
Oil tankers play a fundamental role in every offshore petroleum supply chain and due to its high price, it is essential to optimize its use. Since this optimization requires handling detailed operational aspects, complete optimization models are typically intractable. Thus, a usual approach is to solve a tactical level model prior to optimize the operational details. In this case, it is desirable that tactical models are as precise as possible to avoid too severe adjustments in the next optimization level. In this paper, we study tactical models for a crude oil transportation problem by tankers. We did our work on the top of a previous paper found in the literature. The previous model considers inventory capacities and discrete lot sizes to be transported, aiming to meet given demands over a finite time horizon. We compare several formulations for this model using 50 instances from the literature and proposing 25 new harder ones. A column generation-based heuristic is also proposed to find good feasible solutions with less computational burden than the heuristics of the commercial solver used. 相似文献
The synthesis of a novel fused hexacyclic electron rich monomer incorporating thieno[3,2‐b]thiophene is reported and characterized by single crystal X‐ray diffraction. Suzuki co‐polymerization with benzothiadiazole (BT) afforded a novel low band‐gap polymer P4TBT with high molecular weights and good solution processability. Bulk heterojunction solar cell devices using the P4TBT and [70]PCBM gave power conversion efficiencies of 2.5%. Top‐gate, bottom‐contact field effect transistors (FETs) using P4TBT displayed high hole mobilities of 0.07 cm2 · Vs−1 demonstrating the suitability of the novel monomer and polymer for use in high performing organic electronic devices.
Grinding them down: By using a tailor‐made additive, even in the absence of racemization in solution, abrasive grinding can yield an enantiopure solid state. This novel chiral resolution technique is based on an asymmetric bifurcation in the crystal size distribution as a result of stereoselective hampered crystal growth. R=o‐tolyl.
X-ray structure determinations of mesitylene- and dimesitylmethane-derived compounds bearing bromomethyl units (compounds 1-3) show that the crystal packing of the molecules is characterized by the presence of C-H?Br interactions, such as BrCH2?Br, CH3?Br, and CPhH?Br. In addition, C-Br?Br and C-Br?π interactions determine the crystal packing. The bromomethyl groups play a major role in the packing of 1-3. 相似文献
90Sr was measured in environmental samples in Upper Austria in the year 2005. After the nuclear weapon tests the average deposition of 90Sr in Austria amounted to 3.3 kBq/m². In 1986 the average deposition was 0.9 kBq/m² [1]. To assess the actual condition in soil, grass and cereals 90Sr was measured in these samples. For all samples oxalate precipitation was conducted and strontium specific columns (Eichrom Industries, Inc.) were used. The calcium concentration in these samples was determined to estimate the amount of resin needed for the preparation. For grass and cereal samples columns were packed with the 100–150 μm resin to gain a lower limit of detection LLD below 2 and below 0.1 Bq/kgdry matter respectively. The prepacked 2 mL columns with particle size 100–150 μm were used for soil (LLD below 2 Bq/kgdry matter). After digestion of soil samples, hydroxide precipitation was used as an additional separation step. The 90Sr was measured by liquid scintillation counting. For quality control reasons, first the initial strontium concentration in the sample was determined then a strontium carrier solution was added and after the separation steps the chemical recovery was determined by ICP-MS. Thus, no radioactive tracer and just a small amount of the measuring solution were needed. The results are presented and discussed. These results will be used as reference for further 90Sr analyses which will be conducted in a 5 year period to detect any radiological impact of the nuclear power plant Temelin on the environment of Austria. 相似文献
In the present work, it is proposed, for the first time, an on-line automatic renewable molecularly imprinted solid-phase
extraction (MISPE) protocol for sample preparation prior to liquid chromatographic analysis. The automatic microscale procedure
was based on the bead injection (BI) concept under the lab-on-valve (LOV) format, using a multisyringe burette as propulsion
unit for handling solutions and suspensions. A high precision on handling the suspensions containing irregularly shaped molecularly
imprinted polymer (MIP) particles was attained, enabling the use of commercial MIP as renewable sorbent. The features of the
proposed BI-LOV manifold also allowed a strict control of the different steps within the extraction protocol, which are essential
for promoting selective interactions in the cavities of the MIP. By using this on-line method, it was possible to extract
and quantify riboflavin from different foodstuff samples in the range between 0.450 and 5.00 mg L−1 after processing 1,000 μL of sample (infant milk, pig liver extract, and energy drink) without any prior treatment. For milk
samples, LOD and LOQ values were 0.05 and 0.17 mg L−1, respectively. The method was successfully applied to the analysis of two certified reference materials (NIST 1846 and BCR
487) with high precision (RSD < 5.5%). Considering the downscale and simplification of the sample preparation protocol and
the simultaneous performance of extraction and chromatographic assays, a cost-effective and enhanced throughput (six determinations
per hour) methodology for determination of riboflavin in foodstuff samples is deployed here. 相似文献