Soil inorganic carbon storage pattern in China

Soils with pedogenic carbonate cover about 30% (3.44 × 10⁶ km²) of China, mainly across its arid and semiarid regions in the Northwest. Based on the second national soil survey (1979–1992), total soil inorganic carbon (SIC) storage in China was estimated to be 53.3±6.3 PgC (1 Pg=10¹⁵ g) to the depth investigated to 2 m. Soil inorganic carbon storages were 4.6, 10.6, 11.1, and 20.8 Pg for the depth ranges of 0–0.1, 0.1–0.3, 0.3–0.5, and 0.5–1 m, respectively. Stocks for 0.1, 0.3, 0.5, and 1 m of depth accounted for 8.7%, 28.7%, 49.6%, and 88.9% of total SIC, respectively. In contrast with soil organic carbon (SOC) storage, which is highest under 500–800 mm yr⁻¹ of mean precipitation, SIC storage peaks where mean precipitation is <400 mm yr⁻¹. The amount and vertical distribution of SIC was related to climate and land cover type. Content of SIC in each incremental horizon was positively related with mean annual temperature and negatively related with mean annual precipitation, with the magnitude of SIC content across land cover types showing the following order: desert, grassland >shrubland, cropland >marsh, forest, meadow. Densities of SIC increased generally with depth in all ecosystem types with the exception of deserts and marshes where it peaked in intermediate layers (0.1–0.3 m for first and 0.3–0.5 m for latter). Being an abundant component of soil carbon stocks in China, SIC dynamics and the process involved in its accumulation or loss from soils require a better understanding.     

Effects of water stress on gas exchange of field grown <Emphasis Type="Italic">Zea mays</Emphasis> L. in Southern Italy: an analysis at canopy and leaf level

Zea mays is cultivated in the Mediterranean regions where summer drought may lead to photoinhibition when irrigation is not available. In this work the response of maize to water stress was evaluated by gas exchange measurements at the canopy and leaf level. Leaf gas exchange was assessed before, during and after water stress, while canopy turbulent fluxes of mass and energy were performed on a continuous basis. In the early growth period, a linear increment of net ecosystem photosynthetic rate (P _NE) to incoming of photosynthetic photon flux density (PPFD) was found and net leaf photosynthetic rate (P _NL) showed the tendency to saturate under high irradiance. During water stress, the relationship between P _NE and PPFD became curvilinear and both P _NE and P _NL saturated in a range between 1,000 and 1,500 μmol (photons) m⁻² s⁻¹. Leaf water potential (ψ_l) dropped from −1.50 to −1.88 MPa during water stress, indicating that leaf and canopy gas exchanges were limited by stomatal conductance. With the restoration of irrigation, P _NE, P _NL and ψ_l showed a recovery, and P _NE and P _NL reached the highest values of whole study period. Leaf area index (LAI) reached a value of 3.0 m² m⁻². The relationship between P _NE and PPFD remained curvilinear and P _NE values were lower than those of a typical well-irrigated maize crop. The recovery in P _NE and P _NL after stress, and ψ_l values during stress indicate that the photosynthetic apparatus was not damaged while soil moisture stress after-effects resulted in a sub-optimal LAI values, which in turn depressed P _NE.     

The required role of endogenously produced lipoxin A4 and annexin-1 for the production of IL-10 and inflammatory hyporesponsiveness in mice

The appropriate development of an inflammatory response is central for the ability of a host to deal with any infectious insult. However, excessive, misplaced, or uncontrolled inflammation may lead to acute or chronic diseases. The microbiota plays an important role in the control of inflammatory responsiveness. In this study, we investigated the role of lipoxin A4 and annexin-1 for the IL-10-dependent inflammatory hyporesponsiveness observed in germfree mice. Administration of a 15-epi-lipoxin A4 analog or an annexin-1-derived peptide to conventional mice prevented tissue injury, TNF-alpha production, and lethality after intestinal ischemia/reperfusion. This was associated with enhanced IL-10 production. Lipoxin A4 and annexin-1 failed to prevent reperfusion injury in IL-10-deficient mice. In germfree mice, there was enhanced expression of both lipoxin A4 and annexin-1. Blockade of lipoxin A4 synthesis with a 5-lipoxygenase inhibitor or Abs against annexin-1 partially prevented IL-10 production and this was accompanied by partial reversion of inflammatory hyporesponsiveness in germfree mice. Administration of BOC-1, an antagonist of ALX receptors (at which both lipoxin A4 and annexin-1 act), or simultaneous administration of 5-lipoxygenase inhibitor and anti-annexin-1 Abs, was associated with tissue injury, TNF-alpha production, and lethality similar to that found in conventional mice. Thus, our data demonstrate that inflammatory responsiveness is tightly controlled by the presence of the microbiota and that the innate capacity of germfree mice to produce IL-10 is secondary to their endogenous greater ability to produce lipoxin A4 and annexin-1.     

小黄皮叶挥发油的化学成分

利用水蒸气蒸馏法提取小黄皮叶挥发油,运用毛细管气相色谱-质谱联用法对挥发油进行了分析,分离出40个峰,鉴定了其中的37种成分,所鉴定成分占挥发油总量的99.87%,其主要化学成分为单萜及倍半萜类化合物。     

Human and rat monoamine oxidase-A are differentially inhibited by (S)-4-alkylthioamphetamine derivatives: insights from molecular modeling studies

Four enantiomerically pure (S)-4-alkylthioamphetamine derivatives were evaluated as monoamine oxidase (MAO) inhibitors using the human and rat isoforms of the enzyme. Molecular dockings were performed in order to gain insights regarding the binding mode of these inhibitors. All compounds were potent and selective MAO-A inhibitors although different rank orders of potencies were observed against the enzymes from different species. This behavior can be rationalized on the basis of different binding modes to each enzyme, as determined in silico. These findings further support the concept that MAO inhibitory activity of novel compounds, determined with enzymes from diverse mammalian species, should be considered with caution if human MAO is the final target to be addressed.     

Evolutionary conservation of plant gibberellin signalling pathway components

Background:  

Gibberellins (GA) are plant hormones that can regulate germination, elongation growth, and sex determination. They ubiquitously occur in seed plants. The discovery of gibberellin receptors, together with advances in understanding the function of key components of GA signalling in Arabidopsis and rice, reveal a fairly short GA signal transduction route. The pathway essentially consists of GID1 gibberellin receptors that interact with F-box proteins, which in turn regulate degradation of downstream DELLA proteins, suppressors of GA-controlled responses.     

Angiogenesis and lipoxins

Angiogenesis, the growth of new capillaries from pre-existing ones, occurs through dynamic functions of the endothelial cells (EC), including migration, proliferation and maturation, which are essential to achieve an organized formation of the vessel sprout. Aspirin-triggered lipoxins (ATL), the 15R enantiomeric counterparts of native lipoxins, are endogenous lipid mediators generated within the vascular lumen during multicellular responses, which display potent and well-described immunomodulatory actions. Here we present some of the findings regarding the inhibition of EC responses in vitro and in vivo by these novel compounds and the modulation of fundamental steps of the angiogenic process, identifying previously unappreciated vascular actions of locally generated ATL and their longer acting synthetic analogs.     

Characterization of microsatellite DNA markers in a critically endangered species,Mekong giant catfish,Pangasianodon gigas

Microsatellite DNA markers for a critically endangered Mekong giant catfish (Pangasianodon gigas Roberts and Vidthayanon, 1991) were developed from fin clips collected from captive fish using (GT)₁₅ probe. The number of alleles per locus ranged from two to four. The expected heterozygosities ranged from 0.13 to 0.68. Also, these primers were successfully amplified in four closely related species, Pangasius bocourti, Pangasius conchophilus, Pangasius larnaudii and Pangasius sanitwongsei with the number of alleles per locus ranged from 1 to 13, 1 to 16, 1 to 12 and 1 to 4, respectively. These markers should prove to be very useful for the evaluation of genetic diversity for this species and other related Pangasius species.     

大苞藤黄化学成分研究及其互变异构体超高效液相色谱质谱联用分析

从大苞藤黄枝叶的混合粉碎物中分离到11个化合物,运用光谱手段分别鉴定为neobractatin(1),brasixanthone B (2),5-O-methylxanthone V1 (3),10-O-methylmacluraxanthone (4),isobractatin (5),xanthone V1(6),xerophenone A (7),xerophenone B (8),bractatin (9),macluraxanthone (10)和3-O-methylneobractatin (11).本文首次应用超高效液相色谱-质谱联用技术分离了异构体7和8并测定了其精确分子量.其中化合物6～8为首次从该植物中发现.     

无陪护老年病人住院期间护理需求的质性研究

目的:了解无陪护老年病人在住院期间的护理需求。方法:采用质性研究中现象学研究的半结构化、面对面、深度访谈方法采访11位内科无陪护老年病人,之后依据Claizzit的现象学资料7步分析法分析、整理资料。结果:无陪护老年病人住院期间的需求涉及病室、护理人员、陪护人员三方面。结论:无陪护老年病人住院期间有着其特殊需求,无陪护的原因主要有经济因素及陪护人员综合素质较低、无统一管理等,所以除了医院在护理工作中针对这类病人给予一些特殊照护外,呼吁政府建立规范的陪护人员培训及管理机构,为广大患者提供正规、专业化的陪护。