A theoretical approach on membrane characterization: the deduction of fine structural details of asymmetric nanofiltration membranes

In this study, the effects of polymer concentration on the performances and fine structural details of asymmetric nanofiltration (NF) membranes were investigated. Based on the well known models/equations on pore flow, solution diffusion and extended Nernst–Planck, the experimental data (electrolyte/ions rejection) has been modeled. Spielger– Kedem equations were used to determine the membranes parameters such as reflection coefficient, solute permeability and steric hindrance effects. Employing steric hindrance pore model (SHP) model and Teorell–Meyer Sievers (TMS) model, important membranes structural details in terms of effective pore radius, effective charge density and ratio of effective membrane thickness to membrane porosity have been measured. From the modeling results, it was found that the polymer concentration can influence the membrane performances by varying of structural details. Through the observation using scanning electron microscopy (SEM), it was shown that the produced membranes exhibited a finger-like structure. According to the results obtained from the modeling, these membranes are in range of the commercially available NF membranes

Correction to: De novo variants in SNAP25 cause an early-onset developmental and epileptic encephalopathy.

Unfortunately, in the first sentence in the abstract, a spelling mistake was introduced during the production process after our proofreading. The wording was changed from “aims” to “aimsed.” Heather M. McLaughlin was not listed among the authors. The original article has been corrected

De novo variants in <em>SNAP25</em> cause an early-onset developmental and epileptic encephalopathy.

Purpose: This study aimsed to provide a comprehensive description of the phenotypic and genotypic spectrum of SNAP25 developmental and epileptic encephalopathy (SNAP25-DEE) by reviewing newly identified and previously reported individuals. Methods: Individuals harboring heterozygous missense or loss-of-function variants in SNAP25 were assembled through collaboration with international colleagues, matchmaking platforms, and literature review. For each individual, detailed phenotyping, classification, and structural modeling of the identified variant were performed. Results: The cohort comprises 23 individuals with pathogenic or likely pathogenic de novo variants in SNAP25. Intellectual disability and early-onset epilepsy were identified as the core symptoms of SNAP25-DEE, with recurrent findings of movement disorders, cerebral visual impairment, and brain atrophy. Structural modeling for all variants predicted possible functional defects concerning SNAP25 or impaired interaction with other components of the SNARE complex. Conclusion: We provide a comprehensive description of SNAP25-DEE with intellectual disability and early-onset epilepsy mostly occurring before the age of two years. These core symptoms and additional recurrent phenotypes show an overlap to genes encoding other components or associated proteins of the SNARE complex such as STX1B, STXBP1, or VAMP2. Thus, these findings advance the concept of a group of neurodevelopmental disorders that may be termed “SNAREopathies.”

Genome-wide studies of verbal declarative memory in nondemented older people: The cohorts for heart and aging research in genomic epidemiology consortium

Background Memory performance in older persons can reflect genetic influences on cognitive function and dementing processes. We aimed to identify genetic contributions to verbal declarative memory in a community setting. Methods We conducted genome-wide association studies for paragraph or word list delayed recall in 19 cohorts from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium, comprising 29,076 dementia- and stroke-free individuals of European descent, aged ≥45 years. Replication of suggestive associations (p < 5 × 10−6) was sought in 10,617 participants of European descent, 3811 African-Americans, and 1561 young adults. Results rs4420638, near APOE, was associated with poorer delayed recall performance in discovery (p = 5.57 × 10−10) and replication cohorts (p = 5.65 × 10−8). This association was stronger for paragraph than word list delayed recall and in the oldest persons. Two associations with specific tests, in subsets of the total sample, reached genome-wide significance in combined analyses of discovery and replication (rs11074779 [HS3ST4], p = 3.11 × 10−8, and rs6813517 [SPOCK3], p = 2.58 × 10−8) near genes involved in immune response. A genetic score combining 58 independent suggestive memory risk variants was associated with increasing Alzheimer disease pathology in 725 autopsy samples. Association of memory risk loci with gene expression in 138 human hippocampus samples showed cis-associations with WDR48 and CLDN5, both related to ubiquitin metabolism. Conclusions This largest study to date exploring the genetics of memory function in ~40,000 older individuals revealed genome-wide associations and suggested an involvement of immune and ubiquitin pathways