摘要:

AbstractThe transport of aqueous urea, glucose, and sucrose through the cellulose membrane, Curophane, is described in terms of permeation and frictional coefficients. As for other cellulose materials, hydraulic flow for Cuprophane is predominantly of a capillary nature. While Cuprophane is relatively selective, reflecting more of these solutes than most other cellulose membranes, the observed flow rates through this very thin membrane are quite high. These permeation properties for Cuprophane are accommodated by the frictional description of membrane transport. The data are discussed and compared with other available data on related cellulose systems.

ISSN:0021-9304    

DOI:10.1002/jbm.820050102

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe factor which plays the most important part in surgery of the liver is the liver suture. The considerable tenderness of the hepatic parenchyma causes the sutures to cut through easily, which leads to further complications. Therefore, in their experimental work carried out in rabbits, the authors used Hydron (USA trade‐mark) foils reinforced with polyester netting to serve as bolsters for anchoring the sutures, and to prevent them from cutting through the parenchyma of the operated gland. In addition, the spongy Hydron was tried out to aid the peritonealization process of the resection‐wound surface of the li

ISSN:0021-9304    

DOI:10.1002/jbm.820050103

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe compatibility of implanted ceramic materials with autogenous bone, and the subsequently noted influence of the ceramic on the rate of new bone formation, were investigated to evaluate such materials for use in orthopedic implants. Three ceramic materials, aluminium oxide (Al2O3), zirconium oxide (ZrO2), and calcium aluminate (yCaO · xAl2O3) were tested. These were placed in the femurs of rhesus monkeys for periods of 50, 100, and 350 days. Definite compatability between the autogenous bone and the materials was exhibited for the implant time periods evaluated. No toxicogenic activity was noted in any of the biochemical, biomedical, and ceramographic evolutions. An added benefit resulted from the calcium aluminate composition, which was fabricated as a two‐phase oxide material to make it slightly soluble in the body fluids. In the 50‐ and 100‐ day implants, the bone penetrated the ceramic for distances up to 100 μ while the ceramic dissolved and the pores enlarged. In addition, the mineralization in the area of the calcium aluminate was greater than that found around the other ceramics. Radiographs over the entire 350‐day implant period confirmed the increased callus formation around all of the materials with no signs of rejection evident in the surrounding osseous or soft tissues. After 350 days the entire pore area of the calcium aluminate ceramic was infiltrated with a columnar substance which on the basis of scanning electron microscope procedures was considered to be mineralize

ISSN:0021-9304    

DOI:10.1002/jbm.820050104

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractA series ofDL‐methionine/L‐leucine copolymers was prepared from the corespondingN‐carboxy‐anhydrides. The copolymers formed clear flexible films having low water vapor transmission rates. Peroxide oxidation of the pendant methyl‐theioethyl groups to methyl‐sulfinoethyl groups enhanced the hydrophilic properties of the membranes, and the water vapor transmission rates rapidly increased with an increase in the number of pendant methyl‐sulfinoethyl groups. Increasing the leucine content of the membranes produced a 13‐fold increase in the carbon dioxide permeability and a 6‐fold increase in oxygen permeability, whereas, an increase in the methionine content doubled the carbon dioxide‐oxygen separation factor.Synthetic poly (α‐amino acids) are very similar to naturally occurring proteins with respect to composition and conformation. Because of these similarities, they are being considered in aerosol spray bandages, synthetic skin applications and as coatings for plastic prostheses. The unusual permeability characteristics of theDL‐methionine/L‐leucine copolymers make them interesting membranes for possible use in artificial kidney mach

ISSN:0021-9304    

DOI:10.1002/jbm.820050105

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe flexural tests on 37 whole equine metacarpus bones are described and the results are given in terms of fundamental material properties as a function of age. The moduli of elasticity, rupture, and failure increase then decrease with increasing age. The rupture and failure deformations decrease with age. The stiffness and fragility indices increase with age. Averaging the data for all ages, the modulus of rupture was 35 ksi, the deflection at rupture was 0.22 inches, and the modulus of elasticity was 1.7 × 10 psi. The flexural rupture strength is about twice the uniaxial compression strength and about five times greater than the torsional strength for whole bone tests. The moduli of elasticity are about the same for flexure and uniaxial compression, and about five times greater than the torsional modulus of rigidity for whole equine bone

ISSN:0021-9304    

DOI:10.1002/jbm.820050106

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractA porous ceramic, in the form of small discs, has been implanted into the upper tibiae of adult mongrel dogs in survival experiments. A similar sized disc of a metal (vitallium, titanium, or stainless steel) was also implanted, for comparison, into each tibia. The tissue specimens were studied by microangiography and correlated histology. At the 4‐month, and longer, intervals, the specimens were sectioned with the ceramic discin situ. Injected capillaries were then observed to have penetrated the ceramic.The metals became surrounded by a shell of new‐bone, lined by a fibrous membrane of varying thickness. The ceramic implants, on the other hand, appeared to have remained inert within the cancellous area of the tibiae, not surrounded by either a membrane or an osseous shell.Implications of these findings were discussed and further experiments, some of which are in progress, were propo

ISSN:0021-9304    

DOI:10.1002/jbm.820050107

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractSeveral new surgical techniques in which artificial adhesives are used have been developed. Perforated eyeballs were glued, plastic windows were glued to hazy and opaque corneas, and techniques of retinal surgery wth a minimum use of sutures have been developed.The expanding artificial implant is also described. This is a plastic that imbibes body fluids, swelling to a predetermined volume. Upon swelling, it can fill a cavity or it can produce a deformation in the surrounding tissues. Such a plastic is being investigated as a vitreous substitute. It is also being used to buckle the wall of the eye which carries the blood supply to the retina to reapproximate these layers in order to restore the retina's sensitivity to light. The main feature of this development is that a relatively large implant can be introduced into an organ or tissue through a small incision.

ISSN:0021-9304    

DOI:10.1002/jbm.820050108

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe plasminogen levels and the reactivities of plasmas in two commonly used blood coagulation tests have been compared for man and seven mammals. The plasmas of three nonhuman primates in general reacted as did human plasma in tests for plasminogen activation and in reactivity in the partial thromboplastin time test. The dog had the highest level of plasminogen, and the goat the lowest, of the eight species tested. Overall, the pig appeared to have the most reactive blood coagulation mechanism, clotting the fastest and lysing the slowest, while man's was among the least reactive in clotting and intermediate in lytic activity of those tested. Aside from the nonhuman primates, the calf's clotting and lytic mechanisms resembled those of man more nearly than did those of the other mammals tested. The influence of these species differences on selection of animals forin vivoevaluation of blood vascular prosthetic materials and devices is discussed.

ISSN:0021-9304    

DOI:10.1002/jbm.820050109

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820050101

出版商:Interscience Publishers, a division of John Wiley&Sons, Inc.    

年代:1971

数据来源: WILEY