Atomic force microscopy studies on two-step nucleation and epitaxial growth

Continues advancement and rapid development of techniques operating at the nanoscale open new opportunities to revise and question commonly accepted nucleation and crystal growth theories. Atomic Force Microscopy (AFM) has been successfully involved in various aspects of active pharmaceutical ingredient (API) characterisation including crystal growth, stability of solid dispersions, surface morphology, phase changes and dissolution [1]. Recent studies conducted on proteins crystallisation at nanoscale show new evidence disproving generally accepted Classical Nuclea/on Theory (CNT)[2]. Currently, ‘dense liquid droplets’ seen in protein crystallisation and ‘pre-nucleation clusters’ [3] seen mostly in inorganic salt crystallisation, are two main concepts of non-classical nucleation theory, although no significant progress has been made towards better understanding of mechanisms controlling heterogeneous nucleation in small organic molecules systems, what is in particular interest, as an epitaxial ordering phenomenon is frequently used to enhance nucleation rates and control properties of materials. Our studies present a new light on heteronucleation and the epitaxial growth mechanisms based epitaxial growth of olanzapine dihydrate D on the surface of olanzapine form I (OZPN I) both in high humidity conditions and water solu*on. Results obtained from Peak Force Quan/ta/ve Nanomechanical Mapping Atomic Force Microscopy (PF- QNM-AFM) [4] indicate the presence of intermediate dense liquid-like phase in process of dihydrate D nucleation

An exploration of ebook selection behavior in academic library collections

Academic libraries have offered ebooks for some time, however little is known about how readers interact with them while making relevance decisions. In this paper we seek to address that gap by analyzing ebook transaction logs for books in a university library

Engineering an endocrine Neo-Pancreas by repopulation of a decellularized rat pancreas with islets of Langerhans

Decellularization of pancreata and repopulation of these non-immunogenic matrices with islets and endothelial cells could provide transplantable, endocrine Neo- Pancreata. In this study, rat pancreata were perfusion decellularized and repopulated with intact islets, comparing three perfusion routes (Artery, Portal Vein, Pancreatic Duct). Decellularization effectively removed all cellular components but conserved the pancreas specific extracellular matrix. Digital subtraction angiography of the matrices showed a conserved integrity of the decellularized vascular system but a contrast emersion into the parenchyma via the decellularized pancreatic duct. Islets infused via the pancreatic duct leaked from the ductular system into the peri- ductular decellularized space despite their magnitude. TUNEL staining and Glucose stimulated insulin secretion revealed that islets were viable and functional after the process. We present the first available protocol for perfusion decellularization of rat pancreata via three different perfusion routes. Furthermore, we provide first proof-of-concept for the repopulation of the decellularized rat pancreata with functional islets of Langerhans. The presented technique can serve as a bioengineering platform to generate implantable and functional endocrine Neo-Pancreata

Get a GRIP on Comprehension

Durkin\u27s research (1978-79) has indicated that much more time is spent testing reading comprehension than teaching it. Consequently, all reading comprehension skills need to be taught by the teacher to the students in the classroom. Since making inferences is a necessary comprehension skill when reading across the curriculum (Gordon, 1985), it also must be taught. However, many children find it difficult to make inferences because they are required not only to derive a conclusion from the facts or premises found in their reading materials, but in many cases, they must go beyond the text to their own knowledge and experiences for information. Thus, prior knowledge which student bring to the text, as well as their sensitivity to the text information, are essential aspects of inferential comprehension

Microdeletion of target sites for insulator protein CTCF in a chromosome 11p15 imprinting center in Beckwith-Wiedemann syndrome and Wilms' tumor

We have analyzed several cases of Beckwith-Wiedemann syndrome (BWS) with Wilms' tumor in a familial setting, which give insight into the complex controls of imprinting and gene expression in the chromosome 11p15 region. We describe a 2.2-kbp microdeletion in the H19/insulin-like growth factor 2 (IGF2)-imprinting center eliminating three target sites of the chromatin insulator protein CTCF that we believe here is necessary, but not sufficient, to cause BWS and Wilms' tumor. Maternal inheritance of the deletion is associated with IGF2 loss of imprinting and up-regulation of IGF2 mRNA. However, in at least one affected family member a second genetic lesion (a duplication of maternal 11p15) was identified and accompanied by a further increase in IGF2 rnRNA levels 35-fold higher than control values. Our results suggest that the combined effects of the H19//GF2-imprinting center microdeletion and 11p15 chromosome duplication were necessary for manifestation of BWS

Raman Spectroscopy of Bronze Disease on WWII Artifacts

Patina is a film that forms on bronze or similar metals over a long period of time due to an oxidation reaction. If cuprous chloride in copper alloys are present, it reacts with water to create hydrochloric acid. Hydrochloric acid in the presence of metals will cause corrosions of the bronze and over time it will completely eat away at the metal. This reaction, known as Bronze Disease, is different than patina. Patina can act as a coat and preserver for metals. The University of Northern Iowa’s Museum is experiencing Bronze Disease on artifacts in the WWII collection. The Bronze Disease is destroying the artifacts and causing them to fall apart. If these artifacts go untreated the Bronze Disease will cause complete destruction to the artifacts until they are unrecognizable.https://scholarworks.uni.edu/chemanaly_fa2018/1006/thumbnail.jp

Independent effects of sham laparotomy and anesthesia on hepatic microRNA expression in rats

Background: Studies on liver regeneration following partial hepatectomy (PH) have identified several microRNAs (miRNAs) that show a regulated expression pattern. These studies involve major surgery to access the liver, which is known to have intrinsic effects on hepatic gene expression and may also affect miRNA screening results. We performed two-third PH or sham laparotomy (SL) in Wistar rats to investigate the effect of both procedures on miRNA expression in liver tissue and corresponding plasma samples by microarray and qRT-PCR analyses. As control groups, non-treated rats and rats undergoing anesthesia only were used. Results: We found that 49 out of 323 miRNAs (15%) were significantly deregulated after PH in liver tissue 12 to 48 hours postoperatively (>20% change), while 45 miRNAs (14%) were deregulated following SL. Out of these miRNAs, 10 miRNAs were similarly deregulated after PH and SL, while one miRNA showed opposite regulation. In plasma, miRNA upregulation was observed for miR-133a and miR-133b following PH and SL, whereas miR-100 and miR-466c were similarly downregulated following anesthesia and surgery. Conclusions: We show that miRNAs are indeed regulated by sham laparotomy and anesthesia in rats. These findings illustrate the critical need for finding appropriate control groups in experimental surgery

Discovering the Unfindable: The Tension Between Findability and Discoverability in a Bookshop Designed for Serendipity

Serendipity is a key aspect of user experience, particularly in the context of information acquisition - where it is known as information encountering. Unexpectedly encountering interesting or useful information can spark new insights while surprising and delighting. However, digital environments have been designed primarily for goal-directed seeking over loosely-directed exploration, searching over discovering. In this paper we examine a novel physical environment - a bookshop designed primarily for serendipity - for cues as to how information encountering might be helped or hindered by digital design. Naturalistic observations and interviews revealed it was almost impossible for participants to find specific books or topics other than by accident. But all unexpectedly encoun-tered interesting books, highlighting a tension between findability and discoverability. While some of the bookshop’s design features enabled information en-countering, others inhibited it. However, encountering was resilient, as it occurred despite participants finding it hard to understand the purpose of even those features that did enable it. Findings suggest the need to consider how transparent or opaque the purpose of design features should be and to balance structure and lack of it when designing digital environments for findability and discoverability

Stride Warrior Lite: An Ultra-Lightweight Mobility Device with Storage Options, a padded seat, and handles that adjust to the custom comfort and needs for people with mobility concerns

The Stride Warrior Lite is a walker that takes into account the needs of people with limited mobility. Few carbon fiber walkers and mobility devices exist in the market today; those that are on the market tend to be extremely more expensive than traditional aluminum alternatives. This product aims to serve as a carbon fiber walker that can be manufactured more economically than competitors, while still weighing less than 10 pounds. The majority of the design is manufactured from carbon fiber/epoxy filament-wound tubes, with 3D-printed connectors and steel pins. While the product also includes a cane holder, storage box, and padded seat, the most revolutionary part of the design is the adjustable handles, where the user may adjust the angle to find the most comfortable and ergonomic position. With a focus on being lightweight and ergonomic, the Stride Warrior Lite will prioritize the needs of those with limited mobility, while meeting the strict guidelines for medical devices and being less expensive than competing products

Do metastable polymorphs always grow faster? Measuring and comparing growth kinetics of three polymorphs of tolfenamic acid

The phenomenon of molecular crystal polymorphism is of central importance for all those industries that rely on crystallisation for the manufacturing of their products. Computational methods for the evaluation of thermodynamic properties of polymorphs have become incredibly accurate and a priori prediction of crystal structures is becoming routine. The computational study and prediction of the kinetics of crystallisation impacting polymorphism, however, have received considerably less attention despite their crucial role in directing crystallisation outcomes. This is mainly due to the lack of available experimental data, as nucleation and growth kinetics of polymorphs are generally difficult to measure. On the one hand, the determination of overall nucleation and growth kinetics through batch experiments suffers from unwanted polymorphic transformations or the absence of experimental conditions under which several polymorphs can be nucleated. On the other hand, growth rates of polymorphs obtained from measurements of single crystals are often only recorded along a few specific crystal dimensions, thus lacking information about overall growth and rendering an incomplete picture of the problem. In this work, we measure the crystal growth kinetics of three polymorphs (I, II and IX) of tolfenamic acid (TFA) in isopropanol solutions, with the intention of providing a meaningful comparison of their growth rates. First, we analyse the relation between the measured growth rates and the crystal structures of the TFA polymorphs. We then explore ways to compare their relative growth rates and discuss their significance when trying to determine which polymorph grows faster. Using approximations for describing the volume of TFA crystals, we show that while crystals of the metastable TFA-II grow the fastest at all solution concentrations, crystals of the metastable TFA-IX become kinetically competitive as the driving force for crystallisation increases. Overall, both metastable forms TFA-II and TFA-IX grow faster than the stable TFA-I