The relationship between myenteric neuronal denervation, smooth muscle thickening and epithelial cell proliferation in the rat colon

The aim of the present experiment was to (i) study the healing after 3 and 7 months of bone defects filled with cancellous bovine bone mineral and (ii) compare the healing around implants placed in normal bone and in defects filled with bovine bone mineral. 5 beagle dogs, about 1-year-old, were used. At baseline, extractions of all mandibular left and right premolars were performed. Bone defects were prepared in the left mandibular quadrant. The defect was immediately filled with natural bovine cancellous bone mineral particles (Bio-Oss, Geistlich Sons Ltd. Wolhusen, Switzerland). No resective surgery was performed in the right jaw quadrant. In both quadrants the flaps were adjusted to allow full coverage of the edentulous ridge and sutured. 3 months later, 2 dogs (group I) were euthanized and biopsies from the premolar regions obtained and prepared for histologic analysis. The 3 remaining dogs (group II) were at this time interval (3 months) subjected to implant installation in the premolar region of both the right and left mandibular jaw quadrants. 2 fixtures of the ITI Dental Implant System (Straumann, Waldenburg, Switzerland; solid-screw; 8 x 3.3 mm) were installed in each side. The fixtures in the test side were placed within the previously grafted defect area, while the fixtures in the control side were placed in normally healed extraction sites. A 4 month period of plaque control was initiated. At the end of this period, a clinical examination including assessment of plaque and soft tissue inflammation was performed and radiographs obtained from the implant sites. Biopsies were harvested and 4 tissue samples were yielded per dog, each including the implant and the surrounding soft and hard peri-implant tissues. The biopsies were processed for ground sectioning or "fracture technique" and the sections produced were subjected to histological examination. The volume of the hard tissue that was occupied by clearly identified Bio-Oss particles was reduced between the 3- and 7-month intervals. This indicates that with time, Bio-Oss becomes integrated and subsequently replaced by newly formed bone. In other words, this xenograft fulfils the criteria of an osteoconductive material. It was also observed that 4 months after implant installation, the titanium/hard tissue interface at test and control sites exhibited, from both a quantitative and qualitative aspect, a similar degree of "osseointegration".     

Magnetic and mössbauer study of rare-earth-substituted M-, W- and X-type hexagonal ferrites

The effects of substitution of Ba²⁺ ions for some trivalent rare-earth ions on the magnetic properties and phase formation of M-, W- and X-type hexaferrites are studied. The compounds considered were: Ba_1-RE_x/2Na_x/2Fe₁₂O₁₉ with RE = gadolinium, lanthanum, lutetium, samarium and 0.0 x 0.3; Ba_0.9La_0.05Na_0.05Zn₂Fe₁₆O₂₇ and Ba_1.9La_0.05Na_0.05Zn₂Fe₂₈O₄₆. The samples were prepared by standard ceramic procedures and have been investigated by thermomagnetic analysis, X-ray diffraction, Mössbauer spectroscopy, scanning electron microscope and magnetic measurements. Monophasic BaRE _x/2-M compounds were found for 0.0x<0.2 giving an indication of the solubility range of the rare-earth (RE) atoms in this phase. The intrinsic magnetic properties and the coercive field are lowered with the exception of the lanthanum-substituted hexaferrite. No significant differences in the phase formation and magnetic properties were observed for the W- and X-type hexaferrites.     

Renal and cardiac complications of drug abuse

The case is presented of a young man who, after prolonged intravenous narcotic administration, developed subacute bacterial endocarditis involving the aortic valve, and rapidly progressive glomerulonephritis. After treatment of and recovery from renal failure, persistent proteinuria was shown to be caused by focal glomerulosclerosis. The association of these lesions with "mainlining" is reviewed.     

Influence of pressure and crystallization rate on the surface microhardness of high-density polyethylene

The indentation microhardnessMH of high-density polyethylene crystallized at different pressuresp and crystallization rates _c has been investigated. The results confirm thatMH is an increasing function of lamellar thickness and therefore of density. The rate of increase depends on the crystallization conditionsp and _c. Crystallization at high pressure leads toMH values considerably higher than those of samples prepared under atmospheric pressure. The results are discussed in terms of compressed amorphous regions contributing to an elastic release after removal of the indenter. For samples crystallized under different pressures the hardness value turns out to be nearly independent of the elastic modulusE. For samples crystallized at different rates _c there is a steady decrease of microhardness with increasing _c (decrease of lamellar thickness) but no simple relationship withE. With higher rates _c the appearance of strained tie molecules provokes a rapid increase ofE whileMH decreases further because the crystals become smaller.     

Responses of laboratory-strain Mexican fruit flies,Anastrepha ludens,to combinations of fermenting fruit odor and male-produced pheromone in laboratory bioassays

The attractiveness toA. ludens adults of a combination of odor of fermented chapote fruit and pheromone was compared to attractiveness of both chapote and pheromone in laboratory bioassays. The chemical treatments were tested on 2-day-old and 10- to 12-day-old (sexually immature and mature, respectively), virgin and mated, nonstarved and starved, males and females during the early afternoon when flies were sexually inactive and the late afternoon when sexually mature flies were sexually active. The chapote-pheromone combination was equal to chapote odor alone in attractiveness to males and mated females. Pheromone partially inhibited attraction of immature females to chapote odor. Chapote odor almost completely inhibited attraction of sexually active females to pheromone. The potential for using a combination of chapote and pheromone as a trap bait is discussed.     

Thermoanalytical and rheological characterization of automotive mineral lubricants after thermal degradation

This work aims to characterize thermal degradation process of automotive mineral lubricants, in relation to its rheological and thermoanalytical properties. Lubricants were degraded at temperatures varying from 150 to 210 °C, and times of 1–48 h. After degradation, oils were characterized by infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), rheologic measurements and thermal analysis (TG/DSC). IR and NMR spectra indicated oxidation reaction products. TG curves indicated a decrease in the temperature of decomposition start after degradation. DSC curves indicated a decrease in the peak related to hydrocarbon combustion after degradation. In general, the increase in degradation temperature led to an increase of the lubricants viscosity, besides thixotropy appearance for some samples.     

Interesterification of sesame oil and a fully hydrogenated fat using an immobilized lipase catalyst in both batch and continuous‐flow processes

Lipase‐mediated interesterification of sesame oil and a fully hydrogenated soybean oil was studied at 70 °C in both a batch reactor (BR) and a continuous‐flow packed‐bed reactor (PBR) using four different initial weight ratios of substrates (90 : 10, 80 : 20, 70 : 30 and 60 : 40) with Lipozyme TL IM (Thermomyces lanuginosa) as the biocatalyst. Reaction rates were determined by following the dependence of the profile of the product triacylglycerols (TAG) on the reaction time (BR) or the space time (PBR) via RP‐HPLC‐ELSD. Product TAG identities were confirmed by HPLC‐APCI‐MS. Primary differences between the performances of the two reactors were the maximum level of net hydrolysis (ca. 3 and 10 wt‐% lower acylglycerols at equilibrium for the PBR and BR, respectively), the time or space time required to approach quasi‐equilibrium conditions, and less migration of acyl groups in the PBR trials. For the BR trials, quasi‐equilibrium conditions were approached in 4–6 h, while for the PBR trials short space times (15 min to 2 h) were sufficient to produce effluent compositions similar to equilibrium BR compositions. The predominant TAG families formed by interesterification were LLS, PSO, PSL, SSL, and SSO (L = linoleic; S = stearic; P = palmitic; O = oleic). Oxidative stabilities, melting profiles and solid fat contents were determined for selected reaction products.     

Transesterification of brazilian vegetable oils with methanol over ion-exchange resins

The transesterification of several Brazilian vegetable oils with methanol was carried out at 60°C in the presence of several ion-exchange resins having different structures. The vegetable oils used were from Babassu coconut, corn, palm, palm kernel, and soybean. The effect of the methanol/oil mole ratio and the influences of the structure of the ion-exchange resin and the type of vegetable oil used on the catalytic activity of the ionexchange resins were investigated. The resins used were Amberlyst 15, Amberlyst 31, Amberlyst 35, and Amberlyst 36. Amberlyst 15 produced the best results for the transesterification of vegetable oils. The methyl ester yield is higher for palm kernel oil and Babassu coconut oil than for soybean oil, probably owing to their higher content of shorter-chain FA. Therefore, it was shown that the catalytic activity of the resin depends on the FA composition of the vegetable oil employed.