基于Farquhar改进模型的北亚热带森林常见树种光合限速因子研究

为探讨北亚热带地区植物的光合限速因子,利用改进的Farquhar模型研究了9种常见树种的光合特性。结果表明,与常绿树种相比,落叶树种枫香(Liquidambar formosana)和乌桕(Sapium sebiferum)的最大净光合速率(Pmax)和表观羧化速率(CE)较大;核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)活性是他们的光合限速因子。地带性树种青冈栎(Cyclobalanopsis glauca)的Pmax和CE在常绿木本植物中最大,青冈较强的光合能力可能是来源于Vcmax和TPU。耐阴灌木八角金盘(Fatsia japonica)和美人茶(Camellia uraku)的Pmax较小,其光合限速因子是叶肉细胞导度和呼吸速率。低光照下植物较低的光合能力是由于较小的叶肉导度(gm)和TPU导致的;有效光合辐射短时间的降低使得物种的gm平均减少了60.14%。因此,不同树种在不同环境条件下的光合限速因子不尽相同,应根据树种不同的光合生理特性来合理布局,科学育林。     

Quantifying the Volumetric Performance Metrics of Supercapacitors

Nanostructured materials have greatly improved the performance of electrochemical energy storage devices because of the increased activity and surface area. However, nanomaterials (e.g., nanocarbons) normally possess low packing density, and thus occupy more space which restricts their suitability for making electrochemical devices as compact as possible. This has resulted in their low volumetric performance (capacitance, energy density, and power density), which is a practical obstacle for the application of nanomaterials in mobile and on‐board energy storage devices. While rating electrode materials for supercapacitors, their volumetric performance is equally important as the gravimetric metrics and more reliable in particular for systems with limited space. However, the adopted criteria for measuring the volumetric performance of supercapacitors vary in the literature. Identifying the appropriate performance criteria for the volumetric values will set a universal ground for valid comparison. Here, the authors discuss the rationale for quantifying the volumetric performance metrics of supercapacitors from the three progressive levels of materials, electrodes, and devices. It is hoped that these thoughts will be of value for the general community in energy storage research.     

Progress and Challenges for Live-cell Imaging of Genomic Loci Using CRISPR-based Platforms

Chromatin conformation,localization,and dynamics are crucial regulators of cellular behaviors. Although fluorescence in situ hybridization-based techniques have been widely utilized for investigating chromatin architectures in healthy and diseased states,the requirement for cell fix-ation precludes the comprehensive dynamic analysis necessary to fully understand chromatin activ-ities. This has spurred the development and application of a variety of imaging methodologies for visualizing single chromosomal loci in the native cellular context. In this review,we describe currently-available approaches for imaging single genomic loci in cells,with special focus on clus-tered regularly interspaced short palindromic repeats (CRISPR)-based imaging approaches. In addition,we discuss some of the challenges that limit the application of CRISPR-based genomic imaging approaches,and potential solutions to address these challenges. We anticipate that,with continued refinement of CRISPR-based imaging techniques,significant understanding can be gained to help decipher chromatin activities and their relevance to cellular physiology and pathogenesis.     

CUL4B regulates autophagy via JNK signaling in diffuse large B-cell lymphoma

Aberrant expression of CUL4B was identified in various types of solid cancers. Cumulative evidences support the oncogenic role of CUL4B in cancers, including regulation of cell proliferation and signal transduction. However, its clinical value and potential pathogenic mechanism in diffuse large B-cell lymphoma (DLBCL) have not been described previously. Therefore, we hypothesize that overexpressed CUL4B may contribute to the pathogenesis of DLBCL. The aim of this study is to assess the expression and the biological function of CUL4B in DLBCL progression. In our study, CUL4B overexpression was observed in DLBCL tissues, and its upregulation was closely associated with poor prognosis in patients. Furthermore, the functional roles of CUL4B was detected both in vitro and in vivo. We demonstrated that silencing CUL4B could not only induce cell proliferation inhibition, cell cycle arrest, and motility attenuation of DLBCL cells in vitro, but also decrease tumor growth in DLBCL xenografts mice. In addition, we identi?ed that CUL4B may act as a potent inductor of JNK phosphorylation in regulation of autophagy. Our findings demonstrated a significant role of CUL4B in the development and progression of DLBCL. CUL4B may act as a useful biomarker and a novel therapeutic target in DLBCL.     

Seco-4-methyl-DCK derivatives as potent chemosensitizers

Twenty-five seco-4-methyl-DCK derivatives were designed, synthesized and evaluated for chemoreversal activity when combined with paclitaxel or vincristine in two drug-resistant cancer cell lines (A2780/T and KB-V) respectively. Most of the new compounds displayed moderate to significant MDR reversal activities in the P-gp overexpressing A2780/T and KB-V cells. Especially, compounds 7o and 7y showed the most potent chemosensitization activities with more than 496 and 735 reversal ratios at a concentration of 10?μM. Unexpectedly the newly synthesized compounds did not show chemosensitization activities observed in a non-P-gp overexpressing cisplatin resistant human ovarian cancer cell line (A2780/CDDP), implying that the MDR reversal effects might be associated with P-gp overexpression. Moreover, these compounds did not exhibit significant antiproliferative activities against nontumorigenic cell lines (HUVEC, HOSEC and T29) compared to the positive control verapamil at the tested concentration, which suggested better safety than verapamil. The pharmacological actions of the compounds will be studied further to explore their merit for development as novel candidates to overcome P-gp mediated MDR cancer.     

Effects of climate change and fishing on the Pearl River Estuary ecosystem and fisheries

Reviews in Fish Biology and Fisheries - Climate change poses a challenge to the management of marine ecosystems and fisheries. Estuarine ecosystems in particular are exposed to a broad range of...