Tensile strength is one of the important mechanical properties of concrete, but it is difficult to measure accurately due to the brittle nature of concrete in tension. The three widely used test methods for measuring the tensile strength of concrete each have their shortcomings: the direct tension test equipment is not easy to set up, particularly for alignment, and there are no standard test specifications; the tensile strengths obtained from the test method of splitting tensile strength (American Society for Testing and Materials, ASTM C496) and that of flexural strength of concrete (ASTM C78) are significantly different from the actual tensile strength owing to mechanisms of methodologies and test setup. The objective of this research is to develop a new concrete tensile strength test method that is easy to conduct and the result is close to the direct tension strength.
View Article and Find Full Text PDFSecond branchial cleft cysts are almost always located in the neck; thus, their presence in the nasopharynx is extremely rare. A 44-year-old man was referred to our department because a cystic mass was fortuitously found in the right lateral nasopharyngeal wall during transnasal esophagogastroscopy. He had suffered from intermittent right-sided nasal obstruction since childhood.
View Article and Find Full Text PDFThe synthesis of cyanophycin, a biodegradable polymer, is directed by cyanophycin synthetase. Polymerase chain reaction (PCR) cloned the gene cphA coding for cyanophycin synthetase from Synechocystis sp. PCC 6803 into pET-21b followed by transformation into two Escherichia coli hosts.
View Article and Find Full Text PDFDysphagia can result from a variety of causes, including central nervous and peripheral nervous system, myogenic, and structural disorders. A 76-year-old man underwent anterior cervical disketomy and fusion 10 years ago, with progressive dysphagia noted 2 years ago. Endoscopy showed an oropharyngeal tumor, and lateral plain film evaluation of the neck revealed a cervical plate extrusion.
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