Porcine enamel matrix derivative enhances the formation of reparative dentine and dentine bridges during wound healing of amputated rat molars

We examined the biological effects of porcine enamel matrix derivative (EMD; Emdogain) on the formation of reparative dentine and dentine bridges in rat molars after pulp amputation. The pulp chambers of upper molars of Wistar rats were perforated and the amputated pulp surfaces were directly capped with either EMD or its carrier propylene glycol alginate (PGA) as control. The cavities were then restored with glass-ionomer cement. On post-amputation days 4-30, the dissected maxillae were examined by light and electron microscopy. In PGA-capped pulp, reparative dentine had been formed over the dentine walls under the prepared cavity on day 7 post-amputation and its thickness extended until day 30. On day 30, as well as reparative dentine formation, diffuse calcification had occurred beneath the amputated wound surfaces. Dentine bridge formation under the amputated coronal pulp surface was observed in 18.2% of amputated pulp on day 30. In EMD-capped pulp, reparative dentine had already been formed by odontoblast-like cells over the dentine walls, already on day 4 post-amputation, and its thickness extended until day 30. The Ca and P weight % and Ca/P ratio of reparative dentine matrix were similar to those of pre-existing dentine matrix, and these values were not different between PGA and EMD-capped pulp. Dentine bridge formation was observed in 27.3% of EMD-capped pulp on day 30. Our results suggest that EMD enhances the formation of both reparative dentine and dentine bridges during wound healing of amputated rat molar pulp.     

Effects of steroid hormones on vascular functions

The purpose of this review is to present reported findings of effects of steroids on vascular function and to discuss the biological significance in vascular physiology and pathology. Steroid hormones play various roles in vascular functions through the specific receptor localized in the endothelium and underlying vascular smooth muscle cells (VSMCs). Estrogen replacement therapy in postmenopausal women is in general associated with a reduction in mortality from cardiovascular disease and the beneficial effects of estrogens are caused by modulation of lipid metabolism, expression of leukocyte adhesion molecules, and migration of VSMCs in the vascular wall. Estrogens also play a role as vasodilators through an increment in nitric oxide (NO) production in endothelium or modulation of calcium homeostasis in VSMCs. Some progestin molecules partially oppose the effects of estrogens on vascular functions, but striking differences exist among the types of molecules. Testosterone shows a vasorelaxant response, but detailed actions of androgens on vascular functions remain unknown. Glucocorticoids act on vasoconstriction through reduced prostacyclin production, increased alpha-adrenoceptor numbers, and inhibition of NO synthase, while mineralocorticoids induce hypertrophy and hyperplasia of VSMCs and perivascular fibrosis and cause peripheral vascular resistance, in addition to changes in vascular electrocyte permeability. Some rapid actions of steroids are mediated by "nongenomic" responses in vascular tissues. Recent studies have also demonstrated that steroid-producing or -metabolizing enzymes are expressed in the vascular wall, suggesting the local regulation of steroids in the vascular system. Thus, steroid hormones greatly influence vascular functions and an understanding of the mechanisms may provide new means to prevent vascular diseases.     

A novel anionic surfactant templating route for synthesizing mesoporous silica with unique structure

Anionic surfactants are used in greater volume than any other surfactants because of their highly potent detergency and low cost of manufacture. However, they have not been used as templates for synthesizing mesoporous silica. Here we show a templating route for preparing mesoporous silicas based on self-assembly of anionic surfactants and inorganic precursors. We use aminosilane or quaternized aminosilane as co-structure-directing agent (CSDA), which is different from previous pathways. The alkoxysilane site of CSDA is co-condensed with inorganic precursors; the ammonium site of CSDA, attached to silicon atoms incorporated into the wall, electrostatically interacts with the anionic surfactants to produce well-ordered anionic-surfactant-templated mesoporous silicas (AMS). These have new structures with periodic modulations as well as two-dimensional hexagonal and lamellar phases. The periodic modulations may be caused by the coexistence of micelles that differ in size or curvature, possibly owing to local chirality. These mesoporous silicas provide a new family of mesoporous materials as well as shedding light on the structural behaviour of anionic surfactants.     

Future prospect of remote Cat-CVD on the basis of the production, transportation and detection of H atoms

The future prospect of remote Cat-CVD, in which the decomposition and the deposition chambers are separated, is discussed on the basis of the absolute density measurements of H atoms. It is now well recognized that uniform deposition is possible on a large area without plasma damages by Cat-CVD. However, we may not overlook the demerits in Cat-CVD. One of the demerits is the poisoning of the catalyzer surfaces by the material gases, both temporary and permanent. One technique to overcome this problem is remote Cat-CVD. The question is how to separate the decomposition and deposition areas. If the separation is not enough, there should be back diffusion of the material gases, which will poison the catalyzers. If the separation is too tight, radicals may not effuse out from the decomposition chamber. These problems are discussed and it is shown that SiO₂ coating to reduce the radical recombination rates on walls is promising. The possibility of the polytetrafluoroethene coating by Cat-CVD is also discussed.     

Rules for robust generation of accurate reduced-order models forhigh-speed coupled interconnections

Recently, robust algorithms have been established fur passive order reduction of electrical models of complex interconnection networks. However, very little is known about the way the order of the reduced model should be chosen to ensure accuracy in subsequent transient simulation studies, in this paper, a rule is derived for the selection of the order of the reduced model for interconnections modeled as transmission lines. It is shown that pulse rise time, interconnection length, and physical properties impact the order of the reduced model. The proposed rule is validated through numerical studies involving both analytic and numerical results from the frequency- and time-domain response of multiconductor transmission line circuits     

Effects of polyglycerol esters of fatty acids and ethylene‐vinyl acetate co‐polymer on crystallization behavior of biodiesel

Biodiesel fuels (BDF) have many problems in the cold due to their crystallization properties. In particular, precipitation of large crystals of high‐melting fractions in BDF at low temperatures remarkably changes cold flow property of BDF and, thereby, it increases the values of cold filter plugging point. In this study, we evaluated polyglycerol esters of fatty acids (PGE) and ethylene‐vinyl acetate co‐polymer (EVA) as chemical additives to improve the cold flow property of palm oil‐based FAME (PFME). The results of solid fat content measurement indicate that the simultaneous addition of PGE and EVA showed synergistic effects on suppression of crystallization of PFME, however such effect was not observed when EVA was used alone. DSC thermograms indicated that the PGE additives not only decreased the crystallization temperature but also kinetically suppressed the crystal growth. Polarized light microscopy showed that the simultaneous addition of PGE and EVA led to the formation of considerably small and fine‐dispersed crystals of PFME. These results indicate that combined effects of PGE and EVA caused the formation of fine‐dispersed PFME crystals, which could improve the viscous properties of palm oil‐based BDF at relatively cold temperatures.     

Serologic evidence that streptococcal superantigens are not involved in the pathogenesis of Kawasaki disease

We retrospectively reviewed 11 patients with culture-proven Acanthamoeba keratitis who presented at the National Taiwan University Hospital between 1989 and 1996. We assessed predisposing factors, initial diagnosis, clinical presentation, treatment, and outcome. A history of contact lens-wear, poor contact lens hygiene, intractable eye pain, and ring infiltrates in the cornea were the most prominent characteristics and clinical manifestations. Acanthamoeba keratitis was often misdiagnosed, with herpetic keratitis (7/11) being the most common initial diagnosis from referring hospitals. These patients were usually treated on the basis of the inaccurate diagnosis for more than 1 month (range 1-8 mo) before referral. All patients ultimately received penetrating keratoplasty because of poor response to delayed medical treatment. We suggest that inadequate contact lens hygiene may be important in Acanthamoeba keratitis. This condition is often misdiagnosed and, as early diagnosis is a major factor for successful medical treatment in such patients, awareness in clinical practice is critical.     

A robot language for parts handling based on hierarchical structure of verbs

An operation-level robot language for parts handling has been developed, in which stress is laid on the systematization of the hierarchical structure of verbs (and verb phases) and the realization of and interpreter of the language for controlling a robot arm. In this research, the circumstances are defined as a robot arm, shelves (work benches), boxes and objects on a floor. In the user's programming, eighteen verbs can be utilized: [Level 3] place on, stack on, lift down, carry, direct to, put in, put out, push and draw; [Level 2] have, lift and put; [Level 1] go, raise, lower, seize (grip), detach and turn. In the system, a verb module is reduced to a sequence of the verb modules immediately one level below it, and a series of control commands to a robot controller is automatically generated.     

Difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing

We examined the difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing. The detection limits were measured by using a magneto-resistive sensor. Comparing the frequency of an applied magnetic field, the detection limit at 50 Hz is deeper than that at 1 kHz. Comparing the sample structure, the detection limit in the multi-layered samples is deeper than that in the continuous samples. These results are likely due to the differences in the skin depth and conductivity of the sample.