棕背(鼠平)在不同郁闭度林地下的数量及对预防幼林鼠害的意义

黑龙江省林区林木鼠害危及多种树种(图1-a、b),冬季啃食幼树树皮损失严重。(舒凤梅1975、1979)。为害鼠种主要为棕背(鼠平)(Clethrionomys rufocanus),其他各种鼠为红背(鼠平)(C.rutilus)、东方田鼠(Microtus fortis)、大林姬鼠(Apodemus Peninsulae)、黑线姬鼠（A.agrarius）和花鼠(Eutamias sibiricus)。以往多采用化学药物防治。本工作发现该鼠的数量与林地郁闭度有密切关系,故而探讨了利用调整鼠类栖息环境,预防林木鼠害发生的途径。     

Roles of the ERK, JNK/AP-1/cyclin D1-CDK4 pathway in silica-induced cell cycle changes in human embryo lung fibroblast cells

Silica is a potent occupational fibrogenic agent capable of inducing lung fibrosis and many other lung diseases. Our current study focused on the signalling pathways regulating cell cycle changes in HELF (human embryo lung fibroblast) after silica (α-quartz) exposure. Our results showed silica exposure could lead to cell cycle changes. The cell cycle alternations were accompanied with overexpression of cyclin D1 and CDK4 (cyclin-dependent kinase 4) in a time-dependent manner. Silica exposure also decreased E2F-4 expression in HELF. These changes were blocked by overexpression of dominant-negative mutants of ERK (extracellular signal-regulated protein kinase) or the JNK (stress-activated c-Jun NH2-terminal kinase), respectively. Moreover, pretreatment of cells with curcumin, an activation of AP-1 (activator protein-1) inhibitor, inhibited silica-induced cell cycle alteration, the decreased expression of E2F-4 and overexpression of cyclin D1 and CDK4. Furthermore, both antisense cyclin D1 and antisense CDK4 can block silica-induced cell cycle changes. These results suggest that silica exposure can induce cell cycle changes, which may be mediated through ERK, JNK/AP-1/cyclin D1-CDK4-dependent pathway.     

A simple preparation method of crystals of soybean hull peroxidase

Soybean hull peroxidase (SHP) was crystallised from an enzyme solution with low purity by a simple method. The enzyme solution was purified by cooperation salting out of acetone and ammonium sulphate, and lumpy crystals were obtained with the size of about 40 × 30 μm when ammonium sulphate was quickly added to the enzyme solution. The crystal was examined and confirmed to be an SHP crystal by the method of activity test. The result shows that, though the purity of the enzyme solution was not high, crystals could be formed when the enzyme solution rapidly reached to a degree of supersaturation, which was different from the traditional methods of protein crystallisation. Additionally, a purification method of acetone and ammonium sulphate fractional salting out was also studied, in which the procedure was simplified, and a satisfactory purification effect was obtained.     

松萎蔫病发生区和未发生区油松根部真菌群落研究

植物根部真菌群落结构和多样性与植物的抗病性和病害的危害程度相互影响。为揭示松萎蔫病与松树根部真菌群落的相互作用,该研究对陕西省商洛市柞水县松萎蔫病发生区和未发生区油松的根尖活性、根部外生菌根真菌(ECMF)和深色有隔内生真菌(DSE)的侵染率进行分析,并通过油松根部可培养真菌的分离和鉴定,分析了两地油松根部真菌的群落结构及多样性。结果显示:(1)松萎蔫病未发生区油松根部的活性根尖比、菌根根尖比和ECMF的侵染率均显著高于发生区,而DSE的侵染率和微菌核密度却低于松萎蔫病发生区,ECMF的侵染率在两个样区油松根部都显著高于DSE。(2)从两个样区油松根部共分离到131个菌株,根据形态和分子学特征最终鉴定为23种真菌,其中DSE占绝对优势,且Phialocephala fortinii和Cryptosporiopsis ericae为油松根部分离真菌的优势种。(3)两个样区真菌的群落组成存在明显差异,共有真菌仅5种。(4)松萎蔫病未发生区真菌群落的丰富度(17)和多样性(2.012 0)、以及ECMF的相对丰度(8%)都高于松萎蔫病发生区(分别为11、1.197 9和1.6%),而DSE的相对丰度(70%)却明显低于发生区(82.7%)。研究表明,松萎蔫病的发生影响了油松根部的活性、菌根的形成、ECMF和DSE的侵染,以及根部真菌的群落组成和多样性。该文首次报道了DSE与松萎蔫病的关系,但分离真菌对油松松萎蔫病抗性的影响有待进一步研究。     

Prognostic Value of Tumor-Infiltrating FoxP3+ T Cells in Gastrointestinal Cancers: A Meta Analysis

Purpose

Tumor-infiltrating FoxP3⁺ T cells have been reported in various human tumors, which impaired cell-mediated immunity and promoted disease progression. However, its prognostic value for survival in patients with different gastrointestinal cancers [hepatocellular carcinoma (HCC), colorectal cancer (CRC), gastric cancer (GC)] remains controversial.

Methods

Relevant literature was searched using PubMed, Embase, Cochrane, Ovid Medline and Chinese wanfang databases. A meta-analysis was conducted to estimate pooled survival and recurrence ratios. The odds ratio (OR) and 95% confidence intervals (CI) were calculated employing fixed- or random-effects models depending on the heterogeneity of the included trials.

Results

For HCC and GC, the overall survival at 1, 3 and 5-year of high FoxP3⁺ T cells infiltration patients were lower than low FoxP3⁺ T cells infiltration patients (P<0.05). The recurrences at 1, 3 and 5-year of high FoxP3⁺ T cells infiltration patients were higher than low FoxP3⁺ T cells infiltration patients (P<0.001). But for CRC, the overall survival at 1, 3 and 5-year of high FoxP3⁺ T cells infiltration patients were higher than low FoxP3⁺ T cells infiltration patients (P<0.001). There were no differences in 1, 3 and 5-year recurrences between high and low FoxP3⁺ T cells infiltration patients (P>0.05).

Conclusions

Our findings suggested that tumor-infiltrating FoxP3⁺ T cells were a factor for a poor prognosis for HCC and GC, but a good prognosis for CRC.     

生物表面活性剂生产及应用研究进展

生物表面活性剂主要是由微生物代谢产生的,具有疏水基团和亲水基团的两亲性物质,它们能显著降低表面与界面张力。与化学表面活性剂相比,生物表面活性剂具有毒性低、生物兼容性好、可降解等优点,在众多领域具有良好的应用前景,但生物表面活性剂的高生产成本限制了商业化发展。本文旨在分析微生物表面活性剂的生产,重点是生产过程和代谢途径的优化,以探索产量与成本的关键因素,为生物表面活性剂商业化发展提供解决方案。     

Multi-Proxy Temperature Reconstruction from the West Qinling Mountains,China, for the Past 500 Years

A total of 290 tree-ring samples, collected from six sites in the West Qinling Mountains of China, were used to develop six new standard tree-ring chronologies. In addition, 73 proxy records were assembled in collaboration with Chinese and international scholars, from 27 publically available proxy records and 40 tree-ring chronologies that are not available in public datasets. These records were used to reconstruct annual mean temperature variability in the West Qinling Mountains over the past 500 years (AD 1500–1995), using a modified point-by-point regression (hybrid PPR) method. The results demonstrate that the hybrid PPR method successfully integrates the temperature signals from different types of proxies, and that the method preserves a high degree of low-frequency variability. The reconstruction shows greater temperature variability in the West Qinling Mountains than has been found in previous studies. Our temperature reconstruction for this region shows: 1) five distinct cold periods, at approximately AD 1520–1535, AD 1560–1575, AD 1610–1620, AD 1850–1875 and AD 1965–1985, and four warm periods, at approximately AD 1645–1660, AD 1705–1725, AD 1785–1795 and AD 1920–1945; 2) that in this region, the 20^th century was not the warmest period of the past 500 years; and 3) that a dominant and persistent oscillation of ca. 64 years is significantly identified in the 1640–1790 period.     

The Role of Active Oxide Species for Electrochemical Water Oxidation on the Surface of 3d‐Metal Phosphides

Transition metal phosphides (TMPs) have recently been utilized as promising electrocatalysts for oxygen evolution reaction (OER) in alkaline media. The metal oxides or hydroxides formed on their surface during the OER process are hypothesized to play an important role. However, their exact role is yet to be elucidated. Here unambiguous justification regarding the active role of oxo(hydroxo) species on O‐Ni_(1?x)Fe_xP₂ nanosheet with pyrite structure is shown. These O‐Ni_(1?x)Fe_xP₂ (x = 0.25) nanosheets demonstrate greatly improved OER performance than their corresponding hydroxide and oxide counterparts do. From density function theory (DFT) calculations, it is found that the introduction of iron into the pyrite‐phased NiP₂ alters OER steps occurred on the surface. Notably, the partially oxidized surface of O‐Ni_(1?x)Fe_xP₂ nanosheets is vital to improve the local environment and accelerate the reaction steps. This study sheds light on the OER mechanism of the 3d TMP electrocatalyst and opens up a way to develop efficient and low‐cost electrocatalysts.     

Isolation and characterization of heavy polycyclic aromatic hydrocarbon-degrading bacteria adapted to electrokinetic conditions

Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria capable of growing under electrokinetic conditions were isolated using an adjusted acclimation and enrichment procedure based on soil contaminated with heavy PAHs in the presence of an electric field. Their ability to degrade heavy PAHs under an electric field was individually investigated in artificially contaminated soils. The results showed that strains PB4 (Pseudomonas fluorescens) and FB6 (Kocuria sp.) were the most efficient heavy PAH degraders under electrokinetic conditions. They were re-inoculated into a polluted soil from an industrial site with a PAH concentration of 184.95 mg kg^?1. Compared to the experiments without an electric field, the degradation capability of Pseudomonas fluorescens and Kocuria sp. was enhanced in the industrially polluted soil under electrokinetic conditions. The degradation extents of total PAHs were increased by 15.4 and 14.0 % in the electrokinetic PB4 and FB6 experiments (PB4 + EK and FB6 + EK) relative to the PB4 and FB6 experiments without electrokinetic conditions (PB4 and FB6), respectively. These results indicated that P. fluorescens and Kocuria sp. could efficiently degrade heavy PAHs under electrokinetic conditions and have the potential to be used for the electro-bioremediation of PAH-contaminated soil, especially if the soil is contaminated with heavy PAHs.     

Chronopharmacology and Mechanism of Antitumor Effect of Erlotinib in Lewis Tumor-Bearing Mice

The epidermal growth factor receptor (EGFR), a ubiquitously expressed receptor tyrosine kinase, is recognized as a key mediator of tumorigenesis in many human epithelial tumors. Erlotinib is tyrosine kinase inhibitor approved by FDA for use in oncology. It inhibits the intracellular phosphorylation of tyrosine kinase associated with the EGFR to restrain the development of the tumor. To investigate the antitumor effect of erlotinib at different dosing times and the underlying molecular mechanism via the PI3K/AKT pathway, we established a mouse model of Lewis lung cancer xenografts. The tumor-bearing mice were housed four or five per cage under standardized light-dark cycle conditions (light on at 7:00 AM, 500 Lux, off at 7:00 PM, 0 Lux) with food and water provided ad libitum. The mice were observed for quality of life, their body weight and tumor volume measured, and the tumor growth curves drawn. After being bled, the mice were sacrificed by cervical dislocation. The tumor masses were removed at different time points and weighed. The mRNA expression of EGFR, AKT, Cyclin D1 and CDK-4 were assayed by quantitative real-time PCR (qRT-PCR). Protein expression levels of AKT, P-AKT and Cyclin D1 were determined by Western blot analysis. The results suggest that erlotinib has a significant antitumor effect on xenografts of non-small cell lung cancer in mice, and its efficacy and toxicity is dependent on the time of day of administration. Its molecular mechanism of action might be related to the EGFR-AKT-Cyclin D1-CDK-4 pathway which plays a crucial role in the development of pathology. Therefore, our findings suggest that the time of day of administration of Erlotinib may be a clinically important variable.