Mechanical properties and transition temperatures of crosslinked-oriented gelatin

 This second part of a systematic study of the properties of crosslinked-oriented gelatin involves the effects of orientation and water content on the glass transition temperature T _g and on the melting behavior. The samples were the same as those in the preceding study, and their transition temperatures were determined by both differential scanning calorimetry and dynamic mechanical thermal analysis. The crosslinked gelatin which had been room-conditioned showed two transition temperatures: the lower one was attributed to T _g of the water-plasticized gelatin, and the higher one was interpreted as T _g of dried gelatin superimposed by melting. A rather unusual situation arose because of the fact that the T _g and melting temperatures T _m (217 and 230 ^°C, respectively) are so similar. Using water as plasticizer not only decreases T _g but produces imperfect crystallites which melt below the T _g of the system. The presence of the amorphous phase in the glassy state would presumably make it essentially impossible to define a melting point or crystallization temperature in the normal manner, as an equilibrium between crystalline and amorphous phases. Received: 8 October 1996 Accepted: 2 November 1995     

Sonochemistry on primordial Earth--its potential role in prebiotic molecular evolution

Sonochemical processes are known to occur in nature and have occurred ever since there was liquid water on Earth. We advance a hypothesis that complex carbonaceous compounds, the probable precursors of life, were produced from simple primordial molecules by sonochemical processes in breaking waves of primordial seas or oceans. Our calculations show that these processes were much more common on Earth than other pathways, suggested for the formation of prebiotic complex carbonaceous compounds. The high occurrence rate of sonochemical events in breaking sea waves and the qualitative difference between sonochemical processes and other shock phenomena might have enabled formation of a variety of complex carbonaceous compounds, including amino acids, nucleotides and nucleosides, the precursors of RNA or DNA.     

The Impact of Compaction and Sand Migration on Permeability and Non-Darcy Coefficient from Pore-Scale Simulations

Transport in Porous Media - Compaction and sand migration are important problems in loosely consolidated and unconsolidated high-rate gas reservoirs, and proppants in the hydraulic fractures. Their...     

On ramification in the compositum of function fields

The aim of this paper is twofold: Firstly, we generalize well-known formulas for ramification and different exponents in cyclic extensions of function fields over a field K (due to H. Hasse) to extensions E = F(y), where y satisfies an equation of the form f(y) = u · g(y) with polynomials f(y), g(y) ∈ K[y] and u ∈ F. This result depends essentially on Abhyankar’s Lemma which gives information about ramification in a compositum E = E ₁ E ₂ of finite extensions E ₁, E ₂ over a function field F. Abhyankar’s Lemma does not hold if both extensions E ₁/F and E ₂/F are wildly ramified. Our second objective is a generalization of Abhyankar’s Lemma if E ₁/F and E ₂/F are cyclic extensions of degree p = char(K). This result may be useful for the study of wild towers of function fields over finite fields.     

Synthesis of morphine-d5 and codeine-d8

The synthesis of morphine labeled with deuterium in the N-methyl group and at positions 1 and 6 is described. Reduction of N-carboethoxy-1-bromonorcodeinone (IV) with lithium aluminum deuteride in tetrahydrofuran-d₅ yielded the codeine-d₅. O-Demethylation with sodium propylmercaptide-dimethyl formamide afforded morphine-d₅, which could be remethylated with perdeuterioiodomethane to give codeine-d₈. The labeled compounds are useful as standards for field ionization mass spectrometric analysis.     

Small Complete Caps from Singular Cubics

New families of complete caps in finite Galois spaces are obtained. For most pairs with and , they turn out to be the smallest known complete caps in . Our constructions rely on the bicovering properties of certain plane arcs contained in plane cubic curves with a cusp.     

Bicovering arcs and small complete caps from elliptic curves

Bicovering arcs in Galois affine planes of odd order are a powerful tool for the construction of complete caps in spaces of arbitrarily higher dimensions. The aim of this paper is to investigate whether the arcs contained in elliptic cubic curves are bicovering. As a result, bicovering k-arcs in AG(2,q) of size k≤q/3 are obtained, provided that q?1 has a prime divisor m with 7<m<(1/8)q ^1/4. Such arcs produce complete caps of size kq ^(N?2)/2 in affine spaces of dimension N≡0(mod4). When q=p ^h with p prime and h≤8, these caps are the smallest known complete caps in AG(N,q), N≡0(mod4).     

A Review of HER4 (ErbB4) Kinase,Its Impact on Cancer,and Its Inhibitors

HER4 is a receptor tyrosine kinase that is required for the evolution of normal body systems such as cardiovascular, nervous, and endocrine systems, especially the mammary glands. It is activated through ligand binding and activates MAPKs and PI3K/AKT pathways. HER4 is commonly expressed in many human tissues, both adult and fetal. It is important to understand the role of HER4 in the treatment of many disorders. Many studies were also conducted on the role of HER4 in tumors and its tumor suppressor function. Mostly, overexpression of HER4 kinase results in cancer development. In the present article, we reviewed the structure, location, ligands, physiological functions of HER4, and its relationship to different cancer types. HER4 inhibitors reported mainly from 2016 to the present were reviewed as well.