No abstract

A simple, rapid, and efficient method, vortex-assisted extraction followed by dispersive liquid-liquid microextraction (DLLME) has been developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in sediment samples prior to analysis by high performance liquid chromatography fluorescence detection. Acetonitrile was used as collecting solvent for the extraction of PAHs from sediment by vortex-assisted extraction. In DLLME, PAHs were rapidly transferred from acetonitrile to dichloromethane. Under the optimum conditions, the method yields a linear calibration curve in the concentration range from 10 to 2100 ng g(-1) for fluorene, anthracene, chrysene, benzo[k]fluoranthene, and benzo[a]pyrene, and 20 to 2100 ng g(-1) for other target analytes. Coefficients of determinations ranged from 0.9986 to 0.9994. The limits of detection, based on signal-to-noise ratio of three, ranged from 2.3 to 6.8 ng g(-1) . Reproducibility and recoveries was assessed by extracting a series of six independent sediment samples, which were spiked with different concentration levels. Finally, the proposed method was successfully applied in analyses of real nature sediment samples. The proposed method extended and improved the application of DLLME to solid samples, which greatly shorten the extraction time and simplified the extraction process.

A guided bone regeneration membrane is a pivotal therapeutic modality used to maintain sufficient space for bone regeneration, which is of great significance in curing alveolar bone defects. Metformin has been found to possess the ability of promoting osteogenic differentiation of bone mesenchymal stem cells. To develop guided bone regeneration membranes with better osteoinductive ability, metformin was incorporated into polycaprolactone/chitosan nanofibrous membranes by electrospinning technique, followed by glutaraldehyde crosslinking to reinforce chitosan stability in aqueous solutions. The fabricated nanofibrous membranes were then characterized by scanning electron microscope, Fourier transform infrared spectroscopy, water contact angle testing, mechanical properties test, and drug release test. Furthermore, rats bone mesenchymal stem cells were seeded on membranes for the evaluation of the effect of metformin-loaded polycaprolactone/chitosan nanofibrous membranes on cell morphology, alkaline phosphate activity, and osteogenic mineralization in vitro. Our results showed that nanofibers were fabricated successfully with smooth surface free from beads formation. The crosslinked-polycaprolactone/chitosan/metformin membranes had a more appropriate water contact angle of 44.25 ± 1.37° and the drug release curve of metformin featured early sudden release and slow release in the later stage over a 23-day period. Besides, in vitro studies suggested that the crosslinked-polycaprolactone/chitosan/metformin membrane was more suitable for cell adhesion, proliferation, and osteogenic differentiation of bone mesenchymal stem cells. Consequently, the metformin-loaded polycaprolactone/chitosan nanofibrous membranes would be promoted for bone regeneration as guided bone regeneration membranes.

Olmsted syndrome (OS) is a rare keratinization disorder, typically characterized by two primary diagnostic hallmarks—mutilating palmoplanter and periorificial keratoderma. However, there’s a growing body of literature reporting on the phenotypic diversity of OS, including the absence of aforementioned hallmarks and the presence of some unusual clinical features. Here we presented an atypical familial case of OS that could be confused with Huriez syndrome due to the presence of a scleodactyly-like appearance and tapered fingers in the proband. We ruled out this possibility and made a definitive diagnosis of OS based on clinical features and a genetic assay. Recently, mutations in TRPV3 associated with autosomal dominant or recessive OS continued to be reported, thus conducing to clarifying the underlying relationship between the genotype and phenotype of OS. So we further explored the genotype-phenotype correlation by integrating functionl assays with in silico predictions. Our research not only redefined the phenotypic spectrum of OS, but also provided concrete molecular insights into how mutations in a single gene can lead to significant differences in the severity of this rare disease.

Epidermolysis bullosa (EB) is a heritable blistering disorder. We performed a next‐generation sequencing‐based multigene panel test and successfully predicted 100% of the EB types, including, 36 EB simplex (EBS), 13 junctional EB (JEB), 86 dystrophic EB (DEB), and 3 Kindler EB. Chinese JEB and recessive DEB (RDEB) patients have relatively mild phenotypes; for severe type separately accounts for 45.5% and 23.8%, respectively. We identified 96 novel and 49 recurrent pathogenic variants in 11 genes, although we failed to detect the second mutation in one JEB and five RDEB patients. We identified one novel p.E475K mosaic mutation in the clinically normal mother of one out of 13 EBS patients with KRT5 mutations, one recurrent p.G2034R mosaic mutation, and one novel p.G2043R mosaic mutation in the clinically normal relatives of two out of 19 dominant DEB patients. This study shows that next‐generation technology could be an effective tool in diagnosing EB.