A new oxa-cage natural product daphniacetal A (1) was isolated from
Daphniphyllum macropodum Miq. Its structure and relative configuration were established based on spectroscopic data and the ...single-crystal X-ray diffraction crystallography. Compound
1 was also synthesized for determination of its absolute configuration and evaluation of antioxidant effects.
The purpose of this study was to evaluate the role of 18F fluorodeoxyglucose positron emission tomography (FDG-PET) in influencing salvage treatment decision making for locally persistent ...nasopharyngeal carcinoma (NPC).
A total of 33 NPC patients with histologic persistence at nasopharynx 1 to 6 weeks after a full course of radiotherapy underwent both computed tomography (CT) and FDG-PET/CT simulation at the same treatment position. The salvage treatment decisions, with regard to the decision to offer salvage treatment and the definition of gross tumor volume (GTV), were made before knowledge of the FDG-PET findings. Subsequently the salvage treatment decisions were made again based on the FDG-PET findings and compared with the pre-FDG-PET decisions.
All 33 patients were referred for salvage treatment in the pre-FDG-PET decision. After knowledge of the FDG-PET results, the decision to offer salvage treatment was withdrawn in 4 of 33 patients (12.1%), as no abnormal uptake of FDG was found at nasopharynx. Spontaneous remission was observed in repeat biopsies and no local recurrence was found in these 4 cases. For the remaining 29 patients, GTV based on FDG-PET was smaller than GTV based on CT in 24 (82.8%) cases and was greater in 5 (17.2%) cases, respectively. The target volume had to be significantly modified in 9 of 29 patients (31%), as GTV based on FDG-PET images failed to be enclosed by the treated volume in the salvage treatment plan performed based on GTV based on CT simulation images.
Use of FDG-PET was found to influence the salvage treatment decision making for locally persistent NPC by identifying patients who were not likely to benefit from additional treatment and by improving accuracy of GTV definition in salvage treatment planning.
The discharge of recombinant DNA waste from biological laboratories into the eco-system may be one of the pathways resulting in horizontal gene transfer or “gene pollution”. Heating at 100 °C for ...5–10 min is a common method for treating recombinant DNA waste in biological research laboratories in China. In this study, we evaluated the effectiveness and the safety of the thermo-treatment method in the disposal of recombinant DNA waste. Quantitative PCR, plasmid transformation and electrophoresis technology were used to evaluate the decay/denaturation efficiency during the thermo-treatment process of recombinant plasmid, pET-28b. Results showed that prolonging thermo-treatment time could improve decay efficiency of the plasmid, and its decay half-life was 2.7–4.0 min during the thermo-treatment at 100 °C. However, after 30 min of thermo-treatment some transforming activity remained. Higher ionic strength could protect recombinant plasmid from decay during the treatment process. These results indicate that thermo-treatment at 100 °C cannot decay and inactivate pET-28b completely. In addition, preliminary results showed that thermo-treated recombinant plasmids were not degraded completely in a short period when they were discharged into an aquatic environment. This implies that when thermo-treated recombinant DNAs are discharged into the eco-system, they may have enough time to re-nature and transform, thus resulting in gene diffusion.
This paper is concerned with evolution equations of fractional order Dαu(t)=Au(t); u(0)=u0, u′(0)=0, where A is a differential operator corresponding to a coercive polynomial taking values in a ...sector of angle less than π and 1<α<2. We show that such equations are well posed in the sense that there always exists an α-times resolvent family for the operator A.
Telomeres are shortened with each cell division and play an important role in maintaining chromosomal integrity and function. Telomerase, responsible for telomere synthesis, is activated in 90% of ...human tumor cells but seldom in normal somatic cells. Zidovudine (AZT) is a reverse transcriptase inhibitor. In this study, we have investigated the effects of γ-radiation in combination with AZT on telomerase activity (TA), telomere length, DNA single-strand breaks (SSBs), DNA double-strand breaks (DSBs), and the changes in radiosensitivity of human malignant glioma cell line U251. The results showed that the TA was suppressed by AZT but enhanced by irradiation, resulting in a deceleration of restored rate of shortened telomere, decreased repair rate of DNA strand breaks, and increased radiosensitivity of U251 cells. Our results suggested that telomerase activity and telomere length may serve as markers for estimating the efficacy of cancer radiotherapy and reverse transcriptase inhibitors, such as AZT, may be used clinically as a new radiosensitizer in cancer radiotherapy.
Cocatalyst design is a key approach to acquire high solar-energy conversion efficiency for photocatalytic hydrogen evolution. Here a new in situ vapor-phase (ISVP) growth method is developed to ...construct the cocatalyst of 2D PtS nanorectangles (a length of ∼7 nm, a width of ∼5 nm) on the surface of g-C3N4 nanosheets. The 2D PtS nanorectangles/g-C3N4 nanosheets (PtS/CN) show an unusual metal sulfide–support interaction (MSSI), which is evidenced by atomic resolution HAADF-STEM, synchrotron-based GIXRD, XPS and DFT calculations. The effect of MSSI contributes to the optimization of geometrical structure and energy-band structure, acceleration of charge transfer, and reduction of hydrogen adsorption free energy of PtS/CN, thus yielding excellent stability and an ultrahigh photocatalytic H2 evolution rate of 1072.6 μmol h−1 (an apparent quantum efficiency of 45.7% at 420 nm), up to 13.3 and 1532.3 times by contrast with that of Pt nanoparticles/g-C3N4 nanosheets and g-C3N4 nanosheets, respectively. This work will provide a new platform for designing high-efficiency photocatalysts for sunlight-driven hydrogen generation.
Summary Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists are increasingly used in patients with diabetes, and some studies have suggested a beneficial effect on organ fibrosis, but ...their effects on dermal cell growth and extracellular matrix (ECM) turnover are unknown. To investigate the effect of the PPAR-γ agonist troglitazone on cell growth and matrix production in human dermal fibroblasts (HDF), HDF were cultured and grown in a different concentration of troglitazone. PPAR-γ expression and matrix production were measured in HDF in the presence of troglitazone. The mRNA expressions of TGF-β1, collagen I (Col I) and fibronectin (FN) were determined by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). The protein of transforming growth factor-β1 (TGF-β1) was determined by enzyme-linked immunosorbent assay (ELISA) and proteins of Col I and FN were determined by Western blotting. The mRNA expression of TGF-β1, Col I and FN were significantly decreased in HDF in 15–30 μmol l−1 troglitazone compared to the control group with Dulbecco's modified Eagle's medium ( P < 0.01). An obvious decrease of TGF-β1 protein was found in troglitazone-treated groups as compared to the control group ( P < 0.05). Exposure of HDF to troglitazone reduced col I secretion ( P < 0.05), and fibronectin secretion ( P < 0.05). This study suggests that PPAR-γ agonist will provide a novel approach with therapeutic potential in dermal fibrosis, such as hypertrophic scar, keloid and so on.
![Influence of [18F] fluorode...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0360-3016/small "Influence of [18F] fluorodeoxyglucose positron emission tomography on salvage treatment decision making for locally persistent nasopharyngeal carcinoma")
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