Aboveground nitrogen in relation to estimated total plant uptake in maize and bean

The main objective of this field study was to estimate the total plant uptake of soil mineral N in maize (Zea mays L.) and common bean (Phaseolus vulgaris L.) grown in crop rotations under different N content in Nicaragua. Secondary objectives were to estimate the fraction of the measured soil mineral N content taken up in this way, and to determine how the measured N in plant aboveground parts was related to the total mineral N uptake. A large variation in N content was obtained by using data from fertilisation experiments. Plant total N uptake was estimated as the residual N in a mass balance calculation of soil mineral N. Mineral N content in the top 0–0.3 m soil layer in the field cultivations and in tubes isolated from root uptake, and N content in aboveground plant parts were measured every 30 days. Estimated plant total uptake of soil mineral N varied considerably (2.5–14 g N m⁻² 30 day⁻¹) over periods and N treatments. The range of variation was similar for maize and bean. The fraction of the soil mineral N that was taken up by the plant daily varied more in maize (about 0.03–0.12 day⁻¹) than in bean (about 0.05–0.08 day⁻¹). Our results suggest that monthly changes in N in aboveground plant parts were linearly related to plant total N uptake during the same period. Aboveground plant N constituted between about 55% and 80% of total uptake of soil mineral N in maize depending on period within season, whereas for bean it was more constant and smaller (about 40%).     

小注塑机--大业绩

加工厂家中小型注塑机越来越普遍，其给生产和单位成本所赋予的优势并非总是那么明显清晰，本文中加工厂家对使用小型机的经验作了报告。     

Die massenspektrometrische Fragmentierung von Neopentylpolyolestern III Neopentylglycoldifettsäureester

Mass Spectrometric Fragmentation of Neopentylpolyolesters, Part III: Fatty Acid Diesters of Neopentylglycole The fragmentation of the homologous fatty acid diesters of neopentylglycole (C₂ to C₁₈) upon electron impact was investigated. Main fragments arise by M-RCOO and M-RCOOH. Cyclic acetal structures for these ions are postulated. Subsequent fragmentation was elucidated by DADI-measurements and high resolution measurements. The influence of the length of the fatty acid chain upon the fragmentation is discussed. Esters of branched fatty acids can be distinguished from esters of n-fatty acids by characteristic ions.     

Refining Genotypes and Phenotypes in KCNA2-Related Neurological Disorders

Pathogenic variants in KCNA2, encoding for the voltage-gated potassium channel K_v1.2, have been identified as the cause for an evolving spectrum of neurological disorders. Affected individuals show early-onset developmental and epileptic encephalopathy, intellectual disability, and movement disorders resulting from cerebellar dysfunction. In addition, individuals with a milder course of epilepsy, complicated hereditary spastic paraplegia, and episodic ataxia have been reported. By analyzing phenotypic, functional, and genetic data from published reports and novel cases, we refine and further delineate phenotypic as well as functional subgroups of KCNA2-associated disorders. Carriers of variants, leading to complex and mixed channel dysfunction that are associated with a gain- and loss-of-potassium conductance, more often show early developmental abnormalities and an earlier onset of epilepsy compared to individuals with variants resulting in loss- or gain-of-function. We describe seven additional individuals harboring three known and the novel KCNA2 variants p.(Pro407Ala) and p.(Tyr417Cys). The location of variants reported here highlights the importance of the proline(405)–valine(406)–proline(407) (PVP) motif in transmembrane domain S6 as a mutational hotspot. A novel case of self-limited infantile seizures suggests a continuous clinical spectrum of KCNA2-related disorders. Our study provides further insights into the clinical spectrum, genotype–phenotype correlation, variability, and predicted functional impact of KCNA2 variants.     

Biocompatibility of Lithium Disilicate and Zirconium Oxide Ceramics with Different Surface Topographies for Dental Implant Abutments

Gingivafibroblasts were cultured on lithium disilicate, on zirconia dioxide, and on titanium with two different surface roughnesses (0.2 µm and 0.07 µm); Proliferation (MTT), Living/Dead staining, cytotoxicity (LDH), proliferation (FGF2), and inflammation (TNFα) were analyzed after 1 day and 21 days. Furthermore, alteration in cell morphology (SEM) was analyzed. The statistical analysis was performed by a Kruskal–Wallis test. The level of significance was set at p < 0.05. There were no distinct differences in cellular behavior between the tested roughness. There were slight differences between tested materials. Cells grown on zirconia dioxide showed higher cytotoxic effects. Cells grown on lithium disilicate showed less expression of TNFα compared to those grown on zirconia dioxide or titanium. These effects persisted only during the first time span. The results indicate that the two tested high-strength ceramics and surface properties are biologically suitable for transmucosal implant components. The findings may help clinicians to choose the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.     

Sex Pheromone of <Emphasis Type=BoldItalic>Agriotes acuminatus</Emphasis> (Stephens, 1830) (Coleoptera: Elateridae)

The click beetle species Agriotes acuminatus is distributed in open deciduous forests throughout a large area in Europe. In order to identify its sex pheromone, gland extracts of female beetles were investigated by using GC/MS. Neryl butanoate and 2,6-dimethyl-(Z,E)-2,6-octadien-1,8-diol dihexanoate, in a ratio of approximately 1:5, were the only volatile compounds present in the extracts. Structures of both esters were confirmed by synthesis. Field experiments revealed a strong attraction of A. acuminatus males towards neryl butanoate, which could be synergistically enhanced by addition of 2,6-dimethyl-(Z,E)-2,6-octadien-1,8-diol dihexanoate. The latter compound alone did not show any attractive effect. While all Agriotes spp. investigated to date use geranyl and/or (E,E)-farnesyl esters as sex pheromones, the nerol derivatives of A. acuminatus are the first (Z)-2-configurated pheromones within this genus.     

Efficient and damage-free ultrashort pulsed laser cutting of polymer intraocular lens implants

Ophthalmic intraocular lenses are conventionally machined by diamond tools. A promising alternative approach is contour cutting by ultrashort pulsed laser micromachining. To improve process knowledge, a parametric study of picosecond and femtosecond laser machining of medical grade hydrophilic copolymers and PMMA is carried out. Material removal rates and machining quality with respect to main process parameters are determined. Reasons for chipping and formation of heat affected zones are identified and an optimized process strategy is derived. By choosing a defined pulse overlap, heat accumulation is kept minimal while increasing absorptivity through incubation avoids chipping.     

Improving the thickness accuracy of cold rolled narrow strip by piezoelectric roll gap control at high rolling speed

Particularly in fast rolling mills, conventional actuators reach their dynamic limits, when longitudinal thickness variations of the incoming strip shall be reduced with high accuracy by model-predictive roll gap control. Accordingly, the applicability of highly dynamic piezoelectric actuators in combination with electromechanical spindles and a high frequency precision measurement of the thickness in front of the roll gap was examined. Rolling tests in a cold rolling mill for narrow slit strips show that this novel concept is suitable to provide the required dynamic actuation especially at high rolling speed.     

Modification of zeolite surfaces by Grignard reagent

New microporous hybrid organic/inorganic materials were obtained by modification of zeolites using chlorination of their surface, followed by treatment with a Grignard reagent. Loading of butyl groups and retained crystallinity of ZSM-5 type zeolites was higher than for zeolites Y. In contrast to zeolites Y, the lattice parameters of zeolites ZSM-5 increased after surface modification. The obtained hybrid materials on the basis of high-silica zeolites possess a high degree of crystallinity at increased hydrophobicity.