The significant risk factors defined should be addressed preoperatively to decrease the risk for SSI. Wound surveillance in the post-discharge period is necessary for correct estimation of SSI rates.

No abstract

Bei der Hydroformylierung von Acrylnitril (I) mit Synthesegas in Methanol unter Druck mit Kobaltcarbonylverbindungen als Katalysatoren entstehen als Hauptprodukte β‐Cyanpropionaldehyd (II) und sein Dimethylacetal (III).

The authors conducted a number of studies of the air in the operating room, dressing room, and wards, and checked the sterility of surgical staff hands, dressing material, instruments, and sterile solutions. Based on their findings, the authors believe that strict isolation of purulent patients is desirable.

Plastic forming of bodies is one of the main industrial methods of obtaining silicon carbide products. This method accounts for approximately 60% of their total production. Selection of the composition of the bodies used for obtaining highquality preforms is based on ensuring the maximum packing density of the polyfraction silicon carbide by optimizing its granulometrie composition and determining the appropriate filler-to-binder ratio experimentally.This paper deals with a study of.the filler-plasticizer systems as applied to the bodies based on polycrystalline silicon carbide and aims at determining the conditions required for obtaining dense packing in the cured preforms and establishing the relation between these conditions and the technological features of production of the silicon carbide products.Resol phenol-formaldehyde resin (PFR) is used as a binder in the plastic bodies. It not only bonds the filler grains and plasticizes the body but also gives a dense coke residue due to thermal destruction during the subsequent stages of the process [ 1]. In order to increase the content of the coke residue and to improve the plasticizing ability of the binder, commercial-grade carbon is introduced into the body. At the present time, the P-803 commercial-grade carbon (GOST 7885-86) is being used independently of the quantity and the granulometric composition of the original silicon carbode. Besides this, silicon can be introduced as one of the carbide-formers into the binder.We carried out thermogravimetric studies on the systems consisting of commercial-grade carbon and bakelite,* commercial-grade carbon and silicon carbide, and bakelite and silicon carbide. With respect to the thermal effects, the jointly cured systems differ from the original components and the mechanical mixtures (Fig. 1). This can be attributed to the chemical interaction of PFR with the filler and commercial-grade carbon during the curing process. The conclusions drawn from the data of thermogravimetric analysis regarding the superficial interaction of the binder and the filler agree with the results of EPRspectroscopy of the PFR-oxide systems [2]. In this investigation, the PFR-based binder mixed with commercial-grade carbon or with its substituting product is treated as a plasticizer having specific properties. Figure 2 shows the micrographs of the cured preforms of the silicon carbide products obtained according to the method of plastic forming maintaining different contents of primary silicon carbide (SIC'). It can be seen that virtually each and every filler grain is isolated from the other grains and that the intergranular spaces are filled with the plasticizer; the presence of pores is also observed. The significant increase of the pore size with increasing quantity of silicon carbide in the original charge indicates deficiency of the binder.In order to determine the analytical form of the relationship between the parameters characterizing the structural features of the filler-plasticizer system, we shall examine the relative differenc...