Решение задач управления при алмазно-искровом шлифовании сверхтвёрдых материалов

Представлено решение задачи управления, когда по требуемой чертежом шероховатости определяются различные сочетания режимов обработки, которые гарантируют получения необходимого качества поверхности. Результаты исследования проверены при обработке сверхтвёрдых материалов методом алмазно-искрового шлифования.Presented the solution to management tasks, when required by the drawing of roughness are determined by various combinations of processing modes, which guarantee obtaining the necessary surface quality. The study tested the processing of superhard materials by diamond–spark grinding

Toward tailored care for families with multiple problems:A quasi-experimental study on effective elements of care

Several effective interventions have been developed for families with multiple problems (FMP), but knowledge is lacking as to which specific practice and program elements of these interventions deliver positive outcomes. The aim of this study is to assess the degree to which practice and program elements (contents of and structure in which care is provided) contribute to the effectiveness of interventions for FMP in general and for subgroups with child and/or parental psychiatric problems, intellectual disabilities, or substance use. We performed a quasi-experimental study on the effectiveness of practice and program elements provided in attested FMP interventions. Using self-report questionnaires, we measured primary (child's internalizing and externalizing problems) and secondary (parental stress and social contacts) outcomes at the beginning, end, and three months thereafter. By means of Latent Profile Analysis, we identified groups of families receiving similar combinations of practice elements ("profiles"), and we calculated propensity scores. Next, we assessed how practice element profiles and program elements affected improvement in outcomes, and whether these effects were moderated by subgroup characteristics. We found three practice element profiles (explorative/supportive, action-oriented, and their combination), which were equally effective. Regarding program elements, effects were enhanced by more frequent telephone contact between visits and more frequent intervision. Effectiveness of practice and program elements varied for specific FMP subgroups. Variations in the content of care for FMP do not affect its effectiveness, but variations in the structure of the care do. This finding can help to further improve effective interventions

Intragenic and structural variation in the SMN locus and clinical variability in spinal muscular atrophy

Clinical severity and treatment response vary significantly between patients with spinal muscular atrophy. The approval of therapies and the emergence of neonatal screening programmes urgently require a more detailed understanding of the genetic variants that underlie this clinical heterogeneity. We systematically investigated genetic variation other than SMN2 copy number in the SMN locus. Data were collected through our single-centre, population-based study on spinal muscular atrophy in the Netherlands, including 286 children and adults with spinal muscular atrophy Types 1-4, including 56 patients from 25 families with multiple siblings with spinal muscular atrophy. We combined multiplex ligation-dependent probe amplification, Sanger sequencing, multiplexed targeted resequencing and digital droplet polymerase chain reaction to determine sequence and expression variation in the SMN locus. SMN1, SMN2 and NAIP gene copy number were determined by multiplex ligation-dependent probe amplification. SMN2 gene variant analysis was performed using Sanger sequencing and RNA expression analysis of SMN by droplet digital polymerase chain reaction. We identified SMN1-SMN2 hybrid genes in 10% of spinal muscular atrophy patients, including partial gene deletions, duplications or conversions within SMN1 and SMN2 genes. This indicates that SMN2 copies can vary structurally between patients, implicating an important novel level of genetic variability in spinal muscular atrophy. Sequence analysis revealed six exonic and four intronic SMN2 variants, which were associated with disease severity in individual cases. There are no indications that NAIP1 gene copy number or sequence variants add value in addition to SMN2 copies in predicting the clinical phenotype in individual patients with spinal muscular atrophy. Importantly, 95% of spinal muscular atrophy siblings in our study had equal SMN2 copy numbers and structural changes (e.g. hybrid genes), but 60% presented with a different spinal muscular atrophy type, indicating the likely presence of further inter- and intragenic variabilities inside as well as outside the SMN1 locus. SMN2 gene copies can be structurally different, resulting in inter- and intra-individual differences in the composition of SMN1 and SMN2 gene copies. This adds another layer of complexity to the genetics that underlie spinal muscular atrophy and should be considered in current genetic diagnosis and counselling practices

Modular and predictable assembly of porous organic molecular crystals

Nanoporous molecular frameworks are important in applications such as separation, storage and catalysis. Empirical rules exist for their assembly but it is still challenging to place and segregate functionality in three-dimensional porous solids in a predictable way. Indeed, recent studies of mixed crystalline frameworks suggest a preference for the statistical distribution of functionalities throughout the pores rather than, for example, the functional group localization found in the reactive sites of enzymes. This is a potential limitation for 'one-pot' chemical syntheses of porous frameworks from simple starting materials. An alternative strategy is to prepare porous solids from synthetically preorganized molecular pores. In principle, functional organic pore modules could be covalently prefabricated and then assembled to produce materials with specific properties. However, this vision of mix-and-match assembly is far from being realized, not least because of the challenge in reliably predicting three-dimensional structures for molecular crystals, which lack the strong directional bonding found in networks. Here we show that highly porous crystalline solids can be produced by mixing different organic cage modules that self-assemble by means of chiral recognition. The structures of the resulting materials can be predicted computationally, allowing in silico materials design strategies. The constituent pore modules are synthesized in high yields on gram scales in a one-step reaction. Assembly of the porous co-crystals is as simple as combining the modules in solution and removing the solvent. In some cases, the chiral recognition between modules can be exploited to produce porous organic nanoparticles. We show that the method is valid for four different cage modules and can in principle be generalized in a computationally predictable manner based on a lock-and-key assembly between modules