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Underground longwall mining results in both vertical and horizontal ground displacements. Although major studies have been conducted to evaluate vertical displacement component (subsidence), the overall examination of the horizontal displacement of the ground surface has been limited. In this study, investigations were conducted to evaluate the behavior of horizontal ground displacement due to longwall mining. As the magnitude and direction of horizontal ground displacement depend on the surface topography, both flat and rugged terrains were considered in the study. A correlation was developed between horizontal ground displacement and other site and displacement parameters by studying subsidence data of a mined area in the State of Wyoming as well as data collected from other underground mines in other mining regions. Based on the results, in flat grounds, the induced horizontal ground displacements are essentially perpendicular to the subsidence contours with the maximum value typically between 0.20 and 0.35 of the maximum subsidence. An empirical correlation was suggested to determine the horizontal ground displacement using ground subsidence data. For rugged terrains, correlations of the measured horizontal displacements were difficult to find but appear to be related to induced slope instability. Based on these findings, these displacements are directed down slope and have a greater magnitude than the displacements determined in flat terrains. [ABSTRACT FROM AUTHOR]

Various composite materials are now used as artificial tissue substitutes, and are defining new frontiers in tissue engineering. In the present study, composite membranes based on silk fibroin (SF) were fabricated to form a synthetic periosteum. The fabricated membranes were physicochemically characterized by their morphology, porosity, biocompatibility, biodegradability, chemical structure, and mechanical properties. Following the addition of polycaprolactone (PCL) to the silk fibers, there was a 3-5-fold increase in the elongation at break compared with the pure silk membranes, and surface wettability was retained. The degradation time of the SF within the membranes was also prolonged by adding PCL. Compared with pure PCL membranes or plastic culture plates, the SF-based membranes significantly enhanced the cellular viability and osteogenic differentiation capability of MC3T3-E1 cells. Higher expression levels of osteogenic differentiation markers (runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and osteopontin (OP)) further supported the use of the SF component in bone-related applications. A non-rigid internal fixation (non-RIF) fracture model that healed via endochondral bone formation was created, and fracture callus samples were collected to perform micro-computed tomography, histology, and immunohistochemistry analyses at 8 weeks after surgery. A smaller bone volume accompanied by a mineralized bony callus was observed in SF/PCL membrane-treated rats. Immunohistochemistry also indicated that the SF/PCL membrane-treated rats exhibited increased osteocalcin expression but reduced collagen type X expression. These findings could lead to an alternative strategy for treating comminuted fractures with enhanced intramembranous ossification and reduced endochondral ossification. [ABSTRACT FROM AUTHOR]

The stool of patients both undergoing and not undergoing antibiotic treatment was examined for aerobic faecal bacterial flora (quality and quantity) in an intensive care unit. The bacterial flora in the stool of patients not undergoing antibiotic treatment was generally normal. In patients undergoing antibiotic treatment the faecal bacterial flora showed changes as a result of the use of the antibiotic. Under cephalosporin treatment alone (cefotaxime, cefazolin) E. coli was still to be found. In patients being treated with a combination of two or three antibiotics the frequency of occurrence of E. coli was markedly reduced. Pseudomonas aeruginosa were however substantially more often detected showing increased resistance. The wider the antibiotic spectrum, the more facultative pathogenic microorganisms in the faeces increase, especially Pseudomonas aeruginosa, which can then become an important source for nosocomial infections. [ABSTRACT FROM AUTHOR]

The article presents a study acute toxicity of Molyhibit 100, a sodium molybdate dehydrate, to pink shrimp (Penaeus duorarum), mysid shrimp (Mysidopsis bahia) and American oyster (Crassostrea virginica). The study uses graphic and linear regression to calculate the EC50 of oysters. Results suggests that Molyhibit 100 has less impact on marine environment.