Effect of intragastric feeding with qualitatively different mixtures on the microflora composition of the intestines in rats

Rats of four groups each holding 6-8 animals were changed over to intragastric nutrition with different mixtures one week after cannula implantation into the stomach. The observation period constituted 15 days. The rats of two other groups were kept on oral feeding with a common diet. As compared to oral feeding, intragastric one led to alterations in the cecum microflora. More profound hydrolysis of the nutrients contained by the mixture produced a more demonstrable increase in the number of enterobacteria, enterococci, staphylococci, and lactobacilli. Intragastric feeding with a mixture without nitrogenous component sharply reduced the number of lactobacilli in the cecum contents.     

Hybrid Link/Path-Based Design for Translucent Photonic Network Dimensioning

The advancement of ultralong-haul transmission technology has dramatically enhanced the all-optical reaches. However, the actual situations of installed fiber and sites for terrestrial network often prevent implementing a purely transparent network, and thus, opaque reshaping retiming regenerating (3R) regeneration is required to guarantee optical signal reachability. Since 3R regenerators based on optical/electrical/optical conversion tend to dominate the total network costs, an efficient network design method that allocates a minimum number of 3R regenerators to optimum locations is essential to build a cost-effective photonic network. In this paper, we propose such a network-dimensioning method by combining the advantages of link-based and path-based design approaches. It first guarantees optical signal reachability for any possible traffic demand in each segmented linear link. After combining all the links, excessive regenerators are eliminated based on the optical signal quality check with -factor calculation for each wavelength path. A trial design of a large-scale mesh network demonstrated a significant cost savings of more than 30% in comparison with a conventional link-based design. In the trial, the impact of fiber loss coefficient over the total network cost was investigated quantitatively, addressing the importance of such quantitative modeling and analysis.     

Use of biocompatible calcium-phosphate glass ceramic BGC in surgical treatment of maxillary cysts

The possibility of using the granulated form of biocompatible material made of calcium-phosphate glass ceramic BGC for treatment of maxillary cysts was demonstrated.     

Stable operation range for laser diodes with an integrated passivecavity in the presence of external optical feedback

It is shown that a laser diode with an integrated passive cavity yields higher tolerable levels of feedback from distant reflections than an equivalent long solitary laser diode. To ensure this high tolerance for external feedback, the internal feedback level in the integrated passive cavity must be of the order of about 10%. Then the laser diode remains stable up to external feedback levels in excess of 1% even if the internal reflection phase is not carefully adjusted. External reflections from a cleaved fiber end are then not sufficient to drive the laser into coherence collapse, if realistic coupling efficiencies between laser diode and fiber are taken into account. The low feedback sensitivity is explained by the combination of the long effective length of the laser and a high relaxation resonance frequency. Therefore, quantum-well laser diodes with a long length and a high relaxation resonance frequency are likewise expected to exhibit low feedback sensitivity     

Effects of arylthio-and arylseleno(methoxy)methanes on acid corrosion of CT 3 steel

The effects of various arylthio-and arylseleno(methoxy)methanes on corrosion of CT3 steel in sulfuric and hydrochloric acid solutions were studied by gravimetric and voltammetric methods. Some compounds of theses classes were found to be effective inhibitors of the acid corrosion of CT3 steel. The presence of the-X-CH₂-O-CH₃ groups (X = S or Se) in aromatic amines and their derivatives enhanced their inhibitive properties. However, because these groups are highly hydrophobic, the molecules of inhibitors should contain other fragments that ensure sufficient solubility. Original Russian Text ? I.N. Chernyad’ev, A.B. Shein, A.N. Nedugov, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 285–289.     

Countercurrent water-heating system with a heat exchanger in a solar energy collector loop

The counter current heat exchanger theory with periodic inlet temperatures has been applied to analyze the thermal performance of a water heating system. The theoretical results obtained are in agreement with the experimental data reported in the literature.