水分胁迫对小麦叶片光合作用的影响及其与抗旱性的关系

在水分胁迫初期,两个小麦品种叶片光合速率,气孔导度和细胞间隙CO_2浓度降低,气孔限制值增加,光合速率的降低主要是气孔因素的限制。中度到严重水分胁迫使叶片光合速率、气孔导度和气孔限制值降低,细胞间隙CO_2浓度明显增加,且叶圆片放氧能力,叶绿体Hill反应、叶绿素荧光强度和表观量子产额降低,此时光合速率的降低主要是叶肉细胞光合活性的下降引起的。抗旱性弱的郑引一号叶肉细胞光合活性比抗旱性强的丰抗13更容易受到水分胁迫的影响。     

The outcome of radiation therapy as a primary treatment in orbital lymphoma: a systematic review

BackgroundThe extranodal marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) is the most common orbital and adnexal lymphomas. Radiotherapy is one of the most preferred treatment options for orbital lymphomas since they are localized and radiation sensitive. The objective of this study is to evaluate how radiation therapy affected the outcome of orbital MALT lymphoma.Materials and methodsPRISMA guideline was used to conduct this systematic review of electronic databases (PubMed, EMBASE and Cochrane Library), then we assessed the quality of evidence of each paper.ResultsTwenty-five studies were finally included. 94% studies were intended for definitive therapy and almost all of the studies used external radiation sources. The total doses given to the tumor bed ranged from 4 Gy to 55 Gy and were divided into three groups: ultra-low dose (4–6 Gy), standard-dose (24–30.6 Gy), and high-dose (> 30.6 Gy). 75–90% patients showed CR and local relapse was only reported at 3.5–5%. Higher 5-year PFS was reported in the patients group with lens shielding (90.1% vs. 82.1%) and an increase in Meiboscore after RT courses. Toxicities, including dry eye and cataract, were reported in several patients. Acute toxicities subsided gradually over a few months with artificial tears. The risk of early cataract formation increases in patients who received > 30 Gy and lower in the IMRT group.ConclusionRT is a successful primary definitive therapy for low-grade orbital MALT lymphoma, with a high survival rate, low recurrence rate, and typically acceptable toxicity.     

Alkaloid diversity in eleven species of Ormosia and in Clathrotropis macrocarpa (Leguminosae-Papilionoideae)

Quinolizidine alkaloids were surveyed using gas chromatography (GC) and combined mass spectroscopy (MS) in bark or leaves of eleven species ofOrmosia Jackson as well as inClathrotropis macrocarpa Ducke from tropical forests in Latin America. A list of detected alkaloids, with their MS fragmentation patterns and GC retention indices, is given, as are the distribution of alkaloids among the samples and their detected concentrations. Alkaloid diversity inOrmosia was high, and the taxonomic distribution of specific alkaloids was not congruent with morphological taxonomic criteria: Of 143 alkaloids apparent in 14 samples, 65 were observed in only one sample, and no single alkaloid was common to all samples. Within a species, alkaloid concentrations were inconsistent and therefore cannot be used as a taxonomic character. This was shown for leaf alkaloid concentrations of two neighboring conspecific trees in the same habitat. Hemos analizado mediante cromatografia de gases (CG) y espectrometría de masas (EM) la composición en alcaloides quinolizidínicos de muestras de corteza y hojas de once especies deOrmosia Jackson y deClathrotropis macrocarpa Ducke, procedentes de las selvas de Latinoamérica. Presentamos una lista completa de los alcaloides detectados incluyendo sus fragmentos en EM y su índice de retención en CG. También presentamos la distribución de los alcaloides en las muestras y su concentración. La variedad de alcaloides era alta y su distribución por especies no se ajustó con criterios taxonómicos morfológicos: De los 143 alcaloides detectados en 14 muestras, 65 alcaloides estaban presentes en una sola muestra y ningún en todas las muestras. La concentración de los alcaloides en una especie no fue consistente y por lo tanto no puede utilizarse como carácter taxonómico. Esta conclusión proviene del análisis de la concentración de alcaloides en hojas de dos árboles de la misma especie en el mismo hábitat.     

Distribution of quinolizidine alkaloid types in nine Ormosia species (Leguminosae-Papilionoideae)

Quinolizidine alkaloids were surveyed in 22 plant samples, representing nineOrmosia species and up to five different plant parts per species, using combined gas chromatography and mass spectroscopy. The detected alkaloids were classified into 40 structural types. There was a remarkable degree of dissimilarity of alkaloid-type profiles between any two plant samples, including those obtained from the same species and even from a single tree. The similarity of alkaloid-type profiles among the studied samples varied between 0% and 79% (Jaccard similarity coefficient). Of chemotaxonomic interest was the finding of acosmine inO. isthmensis, which previously had been reported only from the related genusAcosmium. Furthermore, the alkaloid-type profile ofO. panamensis seeds was distinct from that of all other samples, supporting the hypothesis that this species is only distantly related to the other Latin AmericanOrmosia species.     

Evaluating sustainability impacts of critical mineral extractions: Integration of life cycle sustainability assessment and SDGs frameworks

The extraction of critical minerals used in clean technologies has profound impacts on sustainable development goals (SDGs). Life cycle sustainability assessment (LCSA) is used to evaluate the sustainability impacts of products and services, but few frameworks exist to support SDGs assessment for the “green minerals” extraction. Here, we propose a mining-specific framework identifying linkages between LCSA and SDGs, along with a process to integrate methods and data. As a proof of concept, we assess the LCSA performance and local-community level SDG impacts of a nickel mining project in Indonesia. Integrating remote sensing, media sources, stakeholder's data, and expert opinion, we find that LCSA encompasses all 17 goals but only a subset of targets and indicators. The study highlights the need to incorporate indigenous people's perspectives in both LCSA and SDG assessments, and points to priority areas for improving life cycle sustainability and SDG outcomes: fighting corruption, protecting cultural heritage, and reducing greenhouse gas emissions. We suggest that this framework can inform corporate social responsibility activities, as well as consumer choices for low-carbon technologies.     

Kinetics of sequential reaction of hydrolysis and sugar degradation of rice husk in ethanol production: effect of catalyst concentration

This study focuses on kinetics of rice husk hydrolysis using sulfuric acid catalyst to produce sugars. The experiments were conducted at various catalyst concentrations. It turned out that during hydrolysis, degradation of sugars was encountered. The kinetics was expressed with both homogeneous and heterogeneous models. At catalyst concentration of higher than 0.44 N, heterogeneous model works better than homogeneous model, while at the lower, both models work well. In the heterogeneous model, it is observed that the mass transfer of sulfuric acid in the particles and the hydrolysis reaction control the rate of hydrolysis. The mass transfer can be described by Fick's law with the effective diffusivity of 1.4×10(-11) cm2/s, while the hydrolysis and sugar degradation rate constants follow Arrhenius equations. In addition, it was experimentally observed that the sugars produced can be converted to ethanol by fermentation using yeast.