Confocal imaging of laminar and turbulent mixing in a microscale multi-inlet vortex nanoprecipitation reactor

Mass production of functional nanoparticles may be realized through flash nanoprecipiation in microscale reactors such as the multi-inlet vortex reactor (MIVR). A comprehensive understanding of mixing in the MIVR is required for process control and reactor design. Mixing in the MIVR is studied using a technique coupling laser induced fluorescence with confocal laser scanning microscopy. It is shown to provide meaningful qualitative and statistical data of the scalar field for analysis and comparison with numerical simulations. Data were collected for four flow rates, showing that mixing is incomplete even at the highest flow rate

A microscale multi-inlet vortex nanoprecipitation reactor: Turbulence measurement and simulation

Microscale reactors capable of generating turbulent flow are used in Flash NanoPrecipitation, an approach to produce functional nanoparticles with unique optical, mechanical and chemical properties. Microreactor design and optimization could be greatly enhanced by developing reliable computational models of the nanoprecipitation process. A microscale multi-inlet vortex nanoprecipitation reactor was investigated using microscopic particle image velocimetry and computational fluid dynamics. Velocity data such as the mean velocity and turbulent kinetic energy displayed good agreement between experiment and simulation over flow conditions ranging from fully laminar to turbulent, demonstrating the accuracy of the simulation model over the entire turbulent transition range

Perturbation theory for a stochastic process with Ornstein-Uhlenbeck noise

The Ornstein-Uhlenbeck process may be used to generate a noise signal with a finite correlation time. If a one-dimensional stochastic process is driven by such a noise source, it may be analysed by solving a Fokker-Planck equation in two dimensions. In the case of motion in the vicinity of an attractive fixed point, it is shown how the solution of this equation can be developed as a power series. The coefficients are determined exactly by using algebraic properties of a system of annihilation and creation operators.Comment: 7 pages, 0 figure

Molecular brewing: molecular structural effects involved in barley malting and mashing

Ten barley samples containing varied protein contents were subject to malting followed by mashing to investigate molecular effects of both barley starch and starch- protein interactions on malting and mashing performances, and the underlying mechanism. Starch granular changes were examined using differential scanning calorimetry and scanning electron microscopy. The molecular fine structures of amylose and amylopectin from unmalted and malted grain were obtained using size-exclusion chromatography. The results showed that both amylose and amylopectin polymers were hydrolyzed at the same time during malting. Protein and amylose content in both unmalted and malted barley significant negatively correlated with fermentable sugar content after mashing. While protein content is currently the main criterion for choosing malting varieties, this study shows that information about starch molecular structure is also useful for determining the release of fermentable sugars, an important functional property. This provides brewers with some new methods to choose malting barley

The Passing of Print

This paper argues that ephemera is a key instrument of cultural memory, marking the things intended to be forgotten. This important role means that when ephemera survives, whether accidentally or deliberately, it does so despite itself. These survivals, because they evoke all those other objects that have necessarily been forgotten, can be described as uncanny. The paper is divided into three main sections. The first situates ephemera within an uncanny economy of memory and forgetting. The second focuses on ephemera at a particular historical moment, the industrialization of print in the nineteenth century. This section considers the liminal place of newspapers and periodicals in this period, positioned as both provisional media for information as well as objects of record. The third section introduces a new configuration of technologies – scanners, computers, hard disks, monitors, the various connections between them – and considers the conditions under which born-digital ephemera can linger and return. Through this analysis, the paper concludes by considering digital technologies as an apparatus of memory, setting out what is required if we are not to be doubly haunted by the printed ephemera within the digital archive

Conditional statistics of passive-scalar mixing in a confined wake flow

Experimental results for conditional statistics in a confined turbulent wake were compared to the linear model and the transported probability density function (PDF) model for predicting the velocity conditioned on scalar mixture fraction and to a linear model for predicting the scalar mixture fraction conditioned on velocity. For velocity conditioned on scalar mixture fraction, the linear model was found to accurately predict the conditional transverse velocity, but for the conditional streamwise velocity, agreement between the experiments and the linear model was poor. The transverse conditional velocity was accurately predicted by the transported PDF model, but for the streamwise conditional velocity, a modified transported PDF model that incorporated two components of the scalar diffusivity tensor had to be used. Finally, it was found that a linear model for predicting the fluctuating scalar conditioned on velocity performed poorly due to the strongly non-Gaussian scalar PDF at the downstream locations investigated

Helicobacter pylori Infection Induces Anemia, Depletes Serum Iron Storage, and Alters Local Iron-Related and Adult Brain Gene Expression in Male INS-GAS Mice

Iron deficiency anemia (IDA) affects > 500 million people worldwide, and is linked to impaired cognitive development and function in children. Helicobacter pylori, a class 1 carcinogen, infects about half of the world’s population, thus creating a high likelihood of overlapping risk. This study determined the effect of H. pylori infection on iron homeostasis in INS-GAS mice. Two replicates of INS-GAS/FVB male mice (n = 9-12/group) were dosed with H. pylori (Hp) strain SS1 or sham dosed at 6–9 weeks of age, and were necropsied at 27–29 weeks of age. Hematologic and serum iron parameters were evaluated, as was gene expression in gastric and brain tissues. Serum ferritin was lower in Hp SS1-infected mice than uninfected mice (p < 0.0001). Infected mice had a lower red blood cell count (p<0.0001), hematocrit (p < 0.001), and hemoglobin concentration (p <0.0001) than uninfected mice. Relative expression of gastric hepcidin antimicrobial peptide (Hamp) was downregulated in mice infected with Hp SS1 compared to sham-dosed controls (p<0.001). Expression of bone morphogenic protein 4 (Bmp4), a growth factor upstream of hepcidin, was downregulated in gastric tissue of Hp SS1-infected mice (p<0.001). Hp SS1-infected mice had downregulated brain expression of tyrosine hydroxylase (Th) (p = 0.02). Expression of iron-responsive genes involved in myelination (myelin basic protein (Mbp) and proteolipid protein 2 (Plp2)) was downregulated in infected mice (p = 0.001 and p = 0.02). Expression of synaptic plasticity markers (brain derived neurotrophic factor 3 (Bdnf3), Psd95 (a membrane associated guanylate kinase), and insulin-like growth factor 1 (Igf1)) was also downregulated in Hp SS1-infected mice (p = 0.09, p = 0.04, p = 0.02 respectively). Infection of male INS-GAS mice with Hp SS1, without concurrent dietary iron deficiency, depleted serum ferritin, deregulated gastric and hepatic expression of iron regulatory genes, and altered iron-dependent neural processes. The use of Hp SS1-infected INS-GAS mice will be an appropriate animal model for further study of the effects of concurrent H. pylori infection and anemia on iron homeostasis and adult iron-dependent brain gene expression

Bringing high-grade arteriovenous malformations under control: clinical outcomes following multimodality treatment in children.

OBJECTIVE:Brain arteriovenous malformations (AVMs) consist of dysplastic blood vessels with direct arteriovenous shunts that can hemorrhage spontaneously. In children, a higher lifetime hemorrhage risk must be balanced with treatment-related morbidity. The authors describe a collaborative, multimodal strategy resulting in effective and safe treatment of pediatric AVMs. METHODS:A retrospective analysis of a prospectively maintained database was performed in children with treated and nontreated pediatric AVMs at the University of California, San Francisco, from 1998 to 2017. Inclusion criteria were age ≤ 18 years at time of diagnosis and an AVM confirmed by a catheter angiogram. RESULTS:The authors evaluated 189 pediatric patients with AVMs over the study period, including 119 ruptured (63%) and 70 unruptured (37%) AVMs. The mean age at diagnosis was 11.6 ± 4.3 years. With respect to Spetzler-Martin (SM) grade, there were 38 (20.1%) grade I, 40 (21.2%) grade II, 62 (32.8%) grade III, 40 (21.2%) grade IV, and 9 (4.8%) grade V lesions. Six patients were managed conservatively, and 183 patients underwent treatment, including 120 resections, 82 stereotactic radiosurgery (SRS), and 37 endovascular embolizations. Forty-four of 49 (89.8%) high-grade AVMs (SM grade IV or V) were treated. Multiple treatment modalities were used in 29.5% of low-grade and 27.3% of high-grade AVMs. Complete angiographic obliteration was obtained in 73.4% of low-grade lesions (SM grade I-III) and in 45.2% of high-grade lesions. A periprocedural stroke occurred in a single patient (0.5%), and there was 1 treatment-related death. The mean clinical follow-up for the cohort was 4.1 ± 4.6 years, and 96.6% and 84.3% of patients neurologically improved or remained unchanged in the ruptured and unruptured AVM groups following treatment, respectively. There were 16 bleeding events following initiation of AVM treatment (annual rate: 0.02 events per person-year). CONCLUSIONS:Coordinated multidisciplinary evaluation and individualized planning can result in safe and effective treatment of children with AVMs. In particular, it is possible to treat the majority of high-grade AVMs with an acceptable safety profile. Judicious use of multimodality therapy should be limited to appropriately selected patients after thorough team-based discussions to avoid additive morbidity. Future multicenter studies are required to better design predictive models to aid with patient selection for multimodal pediatric care, especially with high-grade AVMs