Preparation and Magnetic Manipulation of Fe3O4/Acrylic Resin Core-Shell Microspheres.

Core-shell microspheres refer to duo-layer or multilayer microspheres, which are widely used in drug delivery, microreactors, etc. Accurate manipulation of microspheres is a research hot spot, while traditional manipulation methods including ultrasonic manipulation and laser manipulation still face some limitations. In this study, magnetic core-shell microspheres were adopted to realize the accurate manipulation of microspheres. Combined with microfluidic technology, polystyrene sulfonic acid (PSSA)/Fe3O4 magnetic fluid was utilized as the core material and photosensitive acrylic resin became the shell material. After UV curing, a magnetic core-shell microsphere with an average size of 55 µm could be achieved, and the diameter was uniform and controllable. By adjusting the flow rate of the dispersed phase, the dual-core microspheres with different core particle sizes that ranged from 9.3 to 28.4 µm could be prepared. Experimental results showed that the prepared Fe3O4/acrylic resin core-shell microspheres can be used as functionalized microspheres that have good magnetic response properties and self-assembly ability. In addition, the magnetic manipulation and self-assembly of the prepared core-shell microspheres were presented with different external magnetic fields. The magnetic core-shell microspheres have shown great potential in the fields of biomedical engineering and targeted delivery of drugs.

SMAD6 is frequently mutated in nonsyndromic radioulnar synostosis.

PURPOSE: Radioulnar synostosis (RUS) can be syndromic or nonsyndromic. The genetic basis for several RUS syndromes have been reported. However, the genetic cause of nonsyndromic RUS (nsRUS) remains unknown. METHODS: We performed Giemsa (GTG) banding, Sanger sequencing, and exome sequencing on patients (n = 140) and families (n = 11) who suffered from RUS. RESULTS: GTG banding identified 10% RUS sporadic cases affected by sex chromosome aneuploidy. Sanger sequencing on candidate genes revealed noggin (NOG) rarely mutated in nsRUS. Exome sequencing identified 16 loss-of-function (LOF) and 6 missense variants (minor allele frequency [MAF] < 0.0001) in 22/117 nsRUS sporadic patients. Genetic association analysis found a significant association between SMAD6-LOF variants and nsRUS risk (odds ratio [OR] = 430, 95% confidence interval [CI]: 238-780, P < 0.000001). SMAD6 mutated in nsRUS was further confirmed by direct Sanger sequencing of SMAD6-coding regions on other unrelated cohorts of nsRUS cases or families. In summary, we detected 27 SMAD6 rare variants in nsRUS, most of which were LOF variants, 4 were de novo, and 3 were transmitted in families with autosomal dominant inheritance. CONCLUSION: As an intracellular bone morphogenetic protein (BMP) antagonist gene, SMAD6 is frequently mutated in nsRUS. NOG, which encodes an extracellular BMP antagonist, is rarely mutated in nsRUS. This work is the first genetic study on nsRUS.

Correction: SMAD6 is frequently mutated in nonsyndromic radioulnar synostosis.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Disparate dynamic viscoelastic responses of wheat flour doughs coated with different oils for preventing water evaporation during time sweeps and their mechanisms decoupled.

Various non-volatile oils are currently applied in order to prevent water evaporation from exposed surface of dough during oscillatory measurements. A systemic understanding of their effectiveness in controlling water loss and ensuring accuracy of rheological measurements is necessary. In this work, three kinds of coating oils (vaseline, dimethyl silicone oil and low viscosity silicone oil) were selected to minimize water evaporation from dough of 37%, 42% and 47% water content subjected to time sweep tests under oscillatory mode. Evolution patterns of the storage modulus, loss modulus and loss factor with time were followed, and the mechanisms responsible for the response patterns were decoupled. Disparate dynamic viscoelastic responses were found for the same dough coated with different oils. Spontaneous de-structuring of dough combined with thixotropic effect contributed to the decrease of dynamic modulus and increase of the loss factor with time. Dynamic vapor sorption tests showed that water evaporation did occur for the dough even coated with non-volatile oils including vaseline. Water evaporation led to an accelerated increase in dynamic modulus with time, while had a very limited impact on loss factor. Oil invasion only played a minor role in the decrease in dynamic modulus. The measured modulus was actually a sum of the positive and negative contributions. Vaseline was observed as an effective coating oil for rheological measurements of dough, especially with high water content.

Reaction-diffusion approach to modeling water diffusion in glutinous rice flour particles during dynamic vapor adsorption.

Dynamic vapor sorption (DVS) method is now widely adopted to determine water diffusion properties in food materials using a sheet or bulk particles as test samples. The Fickian second law with an instant equilibrium boundary condition, although commonly used, can not accurately model the water adsorption kinetics during DVS tests. Dynamic water adsorption of glutinous rice flour was measured at 30 °C and eleven relative humidity steps, and modeled using the Fickian second law with three kinds of boundary condition. Results indicated that the boundary conditions had great impacts on the predicted values especially for the initial section in the DVS curves, and that modifying boundary conditions could not improve the fitness of the final section which characterized a continuing slight increase of water concentration. A reaction-diffusion model, which assumes two diffusible water populations and describes water transport as a competition between diffusion and reversible adsorption on solid matrix, was developed and found to be able to capture the features of water diffusion in the whole adsorption duration. Implementation of the reaction-diffusion approach to glutinous rice flour indicated that diffusion of the Langmuir water became very slow when its adsorption reached equilibrium, while the diffusion of the non-Langmuir water slowed down when water clustering occurred, at the same time the rates of the surface adsorption and bulk adsorption began to decrease. The model developed in this work would help to deepen our mechanistic understanding of water diffusion during a isothermal adsorption.

The complete mitochondrial genome of large odorous frog, Odorrana graminea (Amphibia: Ranidae) and phylogenetic analysis.

The mitochondrial genome of Odorrana graminea was sequenced and analyzed. The complete mitochondrial genome is 18,106 bp in length, including 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 21 transfer RNA genes, and a control region (D-loop). All PCGs are initiated by ATN codons, except for GTG for COI and ND5. Five PCGs use a common stop codon of TAA or TAG, whereas COI terminats with AGG as stop codon; ND6 with AGA; the other six ends with an incomplete stop codon (a single stop nucleotide T). The analysis results based on Bayesian inference method provide a useful resource for the phylogenetic studies of superfamily Ranoidea.

Identification and Characterization of a Metalloprotein Involved in Gallium Internalization in Pseudomonas aeruginosa.

Gallium nitrate (Ganite) is a potential drug for the treatment of Pseudomonas aeruginosa infection. CRISPR/Cas9-based gene mutagenesis studies reveal that siderophore pyochelin-facilitated uptake and an ABC transporter are two major Ga3+ internalization pathways in Pseudomonas aeruginosa (P. aeruginosa). Crystal structures reveal that Ga3+ and Fe3+ occupy exactly the same metal site of HitA, a periplasmic iron-binding protein of the ABC transporter system. The study provides a molecular basis for Ga3+ internalization by P. aeruginosa and facilitates gallium-based antimicrobial drug development.

Comparative urbanization of birds in China and Europe based on birds associated with trees.

Urbanization effects on living organisms are spatially heterogeneous. Here we quantified the abundance of birds per tree in forested urban and rural habitats for 85,829 trees mainly in China and Europe. A population model was based on the assumption that: 1) birds have a normally distributed habitat preference; 2) an increase in population size linked to the habitat preference; 3) a population size dependent on the habitat preference; and 4) the removal of a certain fraction of individuals giving rise to extinction. We tested for large-scale differences in the impact of urbanization on the frequency distribution of the difference in abundance between urban and rural habitats in China and parts of Europe. The difference in the frequency distribution of urban population density of birds in trees minus rural population density of birds in trees in China and Europe was statistically significant, suggesting that the abundance of birds differed between trees in urban and rural habitats, but more so in China than in Europe. We hypothesize that more pronounced differences in China than in Europe may have arisen due to the Four Pests Campaign in 1958-1962 that resulted in death of hundreds of millions of birds (mainly tree sparrows Passer montanus, but also numerous other less common species that were starting to become urbanized around 1960). Species that were less common in 1960 could not sustain reductions in population size in urban areas and hence these species are still rare or absent in urban areas today 60 years later.