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931.
932.
933.
The methods producing cold molecules from cold atoms tend to leave molecular ensembles with substantial residual internal energy. For instance, cesium molecules initially formed via photoassociation of cold cesium atoms are in several vibrational levels nu of the electronic ground state. We applied a broadband femtosecond laser that redistributes the vibrational population in the ground state via a few electronic excitation/spontaneous emission cycles. The laser pulses are shaped to remove the excitation frequency band of the nu = 0 level, preventing re-excitation from that state. We observed a fast and efficient accumulation ( approximately 70% of the initially detected molecules) in the lowest vibrational level, nu = 0, of the singlet electronic state. The validity of this incoherent depopulation pumping method is very general and opens exciting prospects for laser cooling and manipulation of molecules.  相似文献   
934.
重组卡介苗感染树突细胞的研究   总被引:1,自引:1,他引:1  
在体内外试验中 ,树突细胞 (DC)均能摄取表达大肠杆菌麦芽糖结合蛋白 (MalE)的重组卡介苗 (rBCG·MalE)。应用流式细胞术测得荧光标记的rBCG·MalE在体内感染DC的水平在 1 % 2 % ,与感染巨噬细胞 (MΦ)的水平相当。体外抗原提呈试验结果显示 ,DC和MΦ能吞噬、加工rBCG·MalE并向T细胞杂交瘤FBU·B1 1提呈MalE蛋白抗原表位 ,而在体内试验中 ,从rBCG·MalE免疫小鼠脾脏中纯化的DC ,可检测到MalE表位MHCⅡ复合物 ,而纯化的MΦs却测不到。这表明DC在起始抗分枝杆菌的免疫保护中发挥关键作用。  相似文献   
935.
A 13-year-old spayed female mixed breed dog was referred for impaired ambulation, limb tremors, back pain, hypergammaglobulinemia on cellulose acetate electrophoresis, and mild proteinuria. Conventional radiology and magnetic resonance imaging (MRI) suggested multifocal neoplastic bone lesions. At the referral examination, lameness and bright red mucous membranes were observed. Severe erythrocytosis, a monoclonal peak in the β-2 globulin detected by capillary zone electrophoresis, severe proteinuria, bone marrow infiltration of plasma cells, and low serum erythropoietin concentrations were reported. The final diagnosis was multiple myeloma associated with severe primary erythrocytosis. This presentation in a dog is interesting because the combination of both disorders is rare in humans and has not been reported in dogs.Key clinical message:Although rare, multiple myeloma and primary erythrocytosis can occur together in dogs.  相似文献   
936.

The demand for cocoa has increased over the past years following the growth of cocoa-based products linked to the rise in living standard in highly populated countries. Cacao industry is therefore currently facing the dilemma of producing more cacao while ensuring its sustainability. Cacao monocrops and agroforestry systems (AFS) are two contrasting ways to produce cocoa, yet their impact on yields, contribution to farmer livelihood, cocoa quality remains understudied. Therefore, we reviewed existing literature comparing (1) monocrop cacao farming systems with (2) simple or (3) complex AFS. We found 19 comparisons of the cocoa yields in monocrops and simple AFS and 20 comparisons of monocrop and complex AFS. Three main research findings derive from this work. First, in about one third of cases, cacao trees yield more (or equally) in AFS than in monocrops. However, when considering only simple AFS, cacao trees yield more or equal to cacao monocrop in 52% of the cases. Second, cocoa AFS yields an average of 14% less than cacao monocrop. Yet, on average simple AFS yielded 2% less than cacao monocrops. Finally, there are too little elements to draw conclusions about the nexus between cocoa quality and cacao tree cultivation system.

  相似文献   
937.
Anthocyanins are important dietary components that play significant roles in human health because of their antioxidant and anti‐inflammatory properties. In the present study nine anthocyanin‐pigmented spring wheat lines grown at two sites in central Saskatchewan, Canada, were evaluated in terms of anthocyanin composition in comparison with four wheat checks over a two‐year period. The genotypes studied were blue‐aleurone and purple‐pericarp wheat. The anthocyanin pigments were quantified and identified with liquid chromatography and mass spectrometry. Two anthocyanin profiles were identified in the breeding lines, namely, blue profile and purple profile. Wheat lines with a purple profile had overall higher anthocyanin concentrations and more pigments than the blue‐aleurone lines. The purple profile was also characterized by the presence of acylated anthocyanins containing malonyl and succinyl substituents, but no acylated pigments were found in the blue profile. Delphinidin was the dominant aglycone in the blue profile, whereas cyanidin was the principal anthocyanidin in the purple profile. Genotype and interactions among genotype, year, and location were found to significantly influence content and composition of anthocyanin pigments. These differences in anthocyanin content and composition reflect various color characteristics and bioactivity for purple or blue wheat when utilized.  相似文献   
938.
The Waxy (Wx) gene in hexaploid wheat (Triticum aestivum L.) encodes granule‐bound starch synthase (GBSS1), which is involved in the synthesis of amylose, a mostly linear glucan polymer that makes up ∼25% of wheat starch. A null mutation of the Wx gene in each of the three genomes is associated with starch almost entirely consisting of the branched glucan polymer amylopectin (waxy starch), with corresponding changes in functionality. However, the rheological behavior of partially waxy starch remains unclear. The objective of this study was to characterize flour and baking quality in 16 near‐isogenic lines, null at the Wx locus on zero, one, two, or all three genomes, grown in four different environments. Across allelic groups, significant variations in amylose concentrations, flour paste viscosity, loaf structure and texture, dough stability, and proximate variables were observed. Because waxy wheat starch has greater water absorbance and resistance to retrogradation than normal starch, its inclusion in flour blends has been suggested as a means of improving the texture and appearance of bakery products and noodles. The results indicate that wheat encoding <3 functional homeologs of GBSS1 produces starch that has potential in the production of certain food items, such as Asian noodles. However, further research is necessary to determine the optimal amylose‐to‐amylopectin ratio to improve baking quality.  相似文献   
939.
The objective of this study was to develop a predictive model for travel speed of softwood sawlog timber transport (STT) vehicles over a range of forest and provincial roads of varying condition for the South African forestry industry. Data was accumulated from both the Eastern Cape/KwaZulu-Natal and Mpumalanga forest regions of South Africa. Vehicle location and payload data were collected remotely using a combination of GPS tracking and remotely sensed data. Road condition, including road width, was assessed for each identified road segment in-field according to a visual condition indicator (VCI) index. Two STT contractors were selected from each forest region transporting pine sawlogs directly from compartment roadside landings to either a processing plant or log storage area. Five STT vehicle types, representative of transport operations in the two forest regions, were assessed. Principal component analysis was conducted to determine the degree of communality between the respective predictor variables combining road width and VCI as one factor, and truck maximum power and the percentage of (legal) maximum payload as a second factor. Comparisons of the correlations between average speed and the respective predictor variables showed that road width and percentage of maximum (legal) payload had the highest correlations. Multiple linear regression of these two factor variables were used in the model showing both variables as significant (p < 0.05) with an adjusted r2 value of 0.52.  相似文献   
940.
Mechanised harvesting operations are becoming more prevalent in South Africa, with the realisation that motor- manual and manual harvesting operations pose significant health and safety risks to workers. However, the potential damage caused by single-grip harvester feed rollers and delimbing knives on the log surface during debranching and debarking of eucalypts pulp logs may negatively affect fibre recovery as opposed to manually debarked logs, which show little or no log surface damage. Compared with manual debarking, this study investi- gated the influence of two mechanised debarking treatments on wood fibre loss on eucalypt log assortments debarked by harvester head feed rollers and delimbing knives. The two mechanised debarking treatments consisted of three and five feed roller passes along the stem surface. In addition to quantifying the magnitude of this fibre loss, a financial evaluation was done to calculate the value of these losses. The three- and five-pass debarking treatments caused significant fibre losses of 1.425 green tonnes per hectare (gt ha?1) and 2.275 gt ha?1, respec- tively, as opposed to manually debarked logs, which produced no fibre losses. Wood fibre losses in terms of total potential (or available) wood mass for three- and five-pass mechanically debarked trees were 1.06% and 1.70%, respectively. These represent a fibre value loss of R441.75 ha?1 and R705.25 ha?1 for three- and five-pass operations, respectively. For the 6.48 million gt y?1 currently mechanically debarked for the South African pulp and paper industry, this equates to fibre value losses of R21.36 million and R34.10 million annually for three- and five-pass operations, respectively.  相似文献   
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