Correlation between interfacial energy and phase diagram in ceramic-metal systems

Estimates of interfacial energies between ceramics (MX) and liquid metals (A) have been arrived at by employing an improved version of the Becker’s model for interfacial energy calculations at liquid metal-liquid metal interfaces to calculate the total energy of interatomic bonds across an interface. The results of such an approximation yield values that are very close to the experimental values; for instance, the estimated value for Al₂O₃/lFe is 2 J · m⁻², which compares well with the experimental data ranging from 1.9 to 2.3 J · m⁻². It is suggested that interfacial energies depend on two terms: (1) the formation energy of MX and (2) the pairwise interaction energies between M and A atoms and X atoms and vacant interstitial sites. It is also found that the calculated interfacial energies in eutectic systems (carbides-metal, etc.) are generally low, while those in the monotectic systems (oxides-metal, etc.) are generally high.     

Phase equilibria in the Cu-Fe-Mo and Cu-Fe-Nb systems

Phase equilibria in the Cu-Fe portion of the Cu-Fe-Mo and the Cu-Fe-Nb systems, in the temperature ranges 1073 to 1573 K and 1373 to 1573 K, respectively, were determined by metallography and scanning electron microscopy-energy dispersive x-ray methods. Based on the present experimental data combined with the previous assessments of the component binary systems, thermodynamic calculations of phase equilibria were carried out adopting the subregular solution model to describe the Gibbs energies of the liquid, bcc, and fcc phases. The evaluated thermodynamic parameters lead to a better fit between calculations and experimental data in both the Cu-Fe-Mo and Cu-Fe-Nb systems.     

PEGylated antibody in organic media

Antibodies were covalently conjugated with poly(ethylene glycol) (PEG) and the properties of the PEGylated antibodies in organic media were investigated. Two types of monoclonal antibody were used in this study. One was a monoclonal antibody (abzyme) that was prepared against a hapten mimicking a transition state of hydrolysis. Another was a monoclonal antibody against estrogen, which is not soluble in water. By electrophoresis and mass spectral analysis, the covalent conjugation with PEG chains was confirmed. The PEGylated antibodies bound to antigens and the PEGylated abzyme catalyzed a hydrolysis reaction in an aqueous solution. The PEGylated antibodies were soluble in dichloromethane and acetone and interacted with antigen either in dichloromethane or in acetone. In conclusion, PEGylated antibodies can be employed as analytical tools for water-insoluble analytes.     

The changes of gap junctions between pituitary folliculo‐stellate cells during the postnatal development of zucker fatty and lean rats

We investigated the effect of leptin on the postnatal development of gap junctions between folliculo‐stellate cells by using Zucker fatty (fa/fa) rats that have defects of the functional leptin receptor. Male Zucker fatty rats (fa/fa) and male Zucker lean rats (+/+) were used at each of the following postnatal ages: 20, 30, 40, 50, 60, 70, 80, 90 days, and 1 year. On one of the aforementioned dates, the anterior pituitary glands were prepared for observation by transmission electron microscopy. We quantified the number of follicles and gap junctions, and calculated the rate of occurrence as the ratio of the number of gap junctions existing between folliculo‐stellate cells per intersected follicular profile. In Zucker lean male rats, the number of gap junctions remained relatively constant from days 50 to 90 (0.44 ± 0.02 to 0.49 ± 0.03), and was similar in 1 year old rats (0.47 ± 0.03). These data were statistically higher compared to Zucker fatty male rats. In Zucker fatty male rats, very few gap junctions were observed in 30‐day‐old rats (0.04 ± 0.01: mean ± SE). This disruption of gap junction formation persisted, and the number of gap junctions remained constant and showed a low level from days 40 to 90 (0.11 ± 0.02 to 0.17 ± 0.02); this finding was similar in 1‐year‐old rats (0.17 ± 0.02). These observations indicate that the effect of leptin over the gap junction formation within the anterior pituitary glands was directly mediated by interaction with the functional leptin receptor present on the folliculo‐stellate cells. Microsc. Res. Tech. 77:31–36, 2014. © 2013 Wiley Periodicals, Inc.     

Surveillance study for clinical stage I testicular seminomas and nonseminomatous germ cell tumors

Intravenous immunoglobulin (IVIG) (Octagam), was used to determine the effect on hyperacute rejection in an ex vivo xenograft model. Six pig kidneys were perfused with IVIG and fresh human AB blood, and six control pig kidneys were simultaneously perfused with albumin and blood from the same donation. The survival of the IVIG-perfused xenografts (median, 6.5 h) was significantly (P = 0.03) longer than the albumin-perfused xenografts (median, 3.5 h). Complement was activated in both groups. The administration of IVIG to the perfused blood resulted in immediate and significantly higher complement activation in the fluid phase as compared with the albumin group. At rejection the fluid phase complement activation was higher in the IVIG group than in the albumin group for C1rs/C1inh complexes, C4bc, Bb and TCC. At the time of rejection both the albumin and the IVIG group demonstrated interstitial tubular haemorrhage, vasculitis or necrosis of glomerular capillaries and glomerular microthrombi. IgM, C1q, C3c, C4 and fibrin were located in arteries and glomeruli and IgG in the interstitium in both groups at rejection. The fluid phase findings are consistent with a modulatory effect of IVIG on complement activation by deviating the classical pathway activation towards the fluid phase. The prolonged survival of the IVIG-perfused kidneys suggests that IVIG may be useful to dampen hyperacute rejection.     

Glial cell line-derived neurotrophic factor/neurturin-induced differentiation and its enhancement by retinoic acid in primary human neuroblastomas expressing c-Ret, GFR alpha-1, and GFR alpha-2

Neuroblastomas often undergo spontaneous differentiation and/or regression in vivo, which is at least partly regulated by the signals through neurotrophins and their receptors. Recently, glial cell line-derived neurotrophic factor (GDNF) and a second family member, neurturin (NTN), have been found to mediate their signals by binding to a heterotetrameric complex of c-Ret tyrosine kinase receptors and glycosylphosphatidylinositol-linked proteins, GFR alpha-1 (GDNFR-alpha) or GFR alpha-2 (TrnR2/GDNFR-beta/NTNR-alpha/RETL2). Here, we studied the effect of GDNF and NTN on human neuroblastomas in the short-term primary culture system, as well as the expression of c-Ret, GFR alpha-1, GFR alpha-2, GDNF, and NTN. GDNF (1-100 ng/ml) induced morphological differentiation in 34 of 38 primary neuroblastomas and an accompanying increase in c-Fos induction. These effects were markedly enhanced by treatment with 5 microM all-trans-retinoic acid. Although GDNF alone induced a rather weak differentiation independent of the disease stages, the enhancement of neurite outgrowth induced by treatment with both GDNF and all-trans-retinoic acid was significantly correlated with younger age (less than 1 year; P = 0.0039), non-stage 4 diseases (P = 0.0023), a single copy of N-myc (P = 0.027), and high levels of TRK-A expression (P = 0.0062). To examine the expression levels of GFR alpha-1, we cloned a short form of the human GFR alpha-1 gene with a 15-bp deletion by screening a human adult substantia nigra cDNA library. Many primary neuroblastomas expressed c-Ret, GFR alpha-1, and GFR alpha-2 as well as their ligands, GDNF and NTN, suggesting the presence of a paracrine or autocrine signaling system within the tumor tissue. The effect of NTN on primary culture cells of neuroblastoma was similar to that of GDNF. These imply that the GDNF(NTN)/c-Ret/GFR alpha-1(GFR alpha-2) signaling may have an important role in regulating the growth, differentiation, and cell death of neuroblastomas.     

Assessment of a new ventricular contractile index obtained with transoesophageal echocardiography before and after cardiopulmonary bypass in cardiac surgical patients

Normal liver can tolerate even a right trisegmentectomy with caudate resection which results' in a reduction of liver volume by 80%, while a decompensated cirrhotic liver cannot tolerate even partial hepatic resection. This can be ascribed to decreased functional volume and the deterioration of individual hepatocyte function, which is caused and amplified by inappropriate intraoperative procedures and postoperative management. Problems related to liver diseases, including liver cirrhosis, jaundice and chronic active hepatitis, operative techniques and postoperative management should be considered during hepatic resection. Pathophysiology and tactics for handling these problems will be described.     

A method of power system simulation considering armature transients of synchronous machines

This paper presents a new method of simulating transient responses of multimachine power systems following a large disturbance. The conventional model used in the simulation is composed mainly of synchronous machine models in which the armature transients are neglected, and steady-state transmission system equations. This is because it is very difficult to treat the transmission system and the armature circuits of synchronous machines as differential equations. Naturally, the model cannot evaluate the effects of these neglected transients. The new method proposed herein uses the new synchronous machine model and the steady-state transmission system model. The former is obtained by modifying slightly the conventional armature-transient neglected model. Thus the resultant simulation model has almost the same structure as the conventional one. However, it can evaluate approximately the effects of armature transients on the dynamical behavior of the synchronous machines. For example, it can evaluate easily the angular backswing following a three-phase short-circuit fault. In addition, the new method can also estimate the maximum values of developed torque, induced voltage and armature current of synchronous machines at the moment when the disturbance occurred and when it was cleared.     

Lymphatic absorption of structured glycerolipids containing medium-chain fatty acids and linoleic acid,and their effect on cholesterol absorption in rats

The effects of various structured triglycerides containing medium-chain (caprylic or capric acids) and long-chain (linoleic acid) fatty acids on fatty acid and cholesterol absorption were studied in lymph-cannulated rats. A considerable portion of capric and caprylic acid was absorbed through the lymph duct, although to a lesser extent than was linoleic acid. Capric and linoleic acid located at the 2-position of 2-decanoyl-1,3-dilinoleoyl-glycerol (18∶2/10∶0/18∶2) and 2-linoleoyl-1,3-didecanoyl-glycerol (10∶0/18∶2/10∶0), respectively, tended to be absorbed more efficiently than those located at the 1- and 3-position or those from tricaprin (10∶0/10∶0/10∶0) or trilinolein (18∶2/18∶2/18∶2). A similar trend was observed when the medium-chain fatty acid was caprylic acid instead of capric acid. Caprylic acid absorption from 2-octanoyl-1,3-dilinoleoylglycerol (18∶2/8∶0/18∶2) was significantly greater (p<0.05) than from 2-linoleoyl-1,3-dioctanoyl-glycerol (8∶0/18∶2/8∶0) or tricaprylin (8∶0/8∶0/8∶0). Preferential absorption of caprylic and linoleic acid was not observed when the 1 to 2 and the 2 to 1 mixtures of 8∶0/8∶0/8∶0 and 18∶2/18∶2/18∶2, respectively, were administered. The structured lipids did not affect the lymphatic absorption of cholesterol. The results suggest that structured triglycerides composed of medium-chain fatty acids and linoleic acid may be more useful for the treatment of lipid malabsorption than are mixtures of medium-chain triglyceride (MCT) and long-chain triglycride (LCT).