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951.
In 1974 in California, 72,645 patients were admitted to hospital for backache. In 50 percent of these patients there was a diagnosis compatible with discogenic disease. Surgical treatment was done in 27 percent of the patients admitted to hospital. Total figures were determined for hospital costs and the costs of physician-related services. Costs for surgical treatment exceeded medical costs. Extrapolated to a national scale, it appears that the national cost for patients in hospital because of backache in 1974 was $1.38 billion. This does not include outpatient care expense or loss of income.  相似文献   
952.
Cerebrosides containing either threo- or erythro-[3-3-H]sphingosine were synthesized by a new procedure. Glucopyranosyl or galactopyranosyl ceramides were converted to their 3-keto derivatives with 2,3-dichloro-5,6-dicyanobenzoquinone and reduced with 3-H-labeled sodium borohydride. The resulting tritiated cerebrosides, which contained erythro- and threo-sphingosines in the ratio of 84:16, were deacylated with butanol-KOH, and the erythro- and threo-psychosines were separated by silica gel column chromatography and reacylated with lignoceroyl chloride.  相似文献   
953.
Henneguya sebasta sp. n. was found on the bulbus and truncus arteriosus and in the heart chambers of 7 species of marine rockfish, Sebastes, from central and southern California. The incidence of this parasite may be of economic interest to the sport and commercial fisheries because of its possible pathogenicity.  相似文献   
954.
955.
Summary Bioprocessing for successful industrial application on the technical scale needs a clearly-defined and well-developed research methodology. This paper intends to contribute to such activity by developing a paradigm from an integrating mode of thinking and working applied to the interdisciplinary field of biotechnology. Bioprocesses are considered as an interactive combination of metabolic mechanisms in the cells and physical transport mechanisms in the bioreactor. The basis for a systematic approach in analysis and design is to quantify and simplify the bioprocesses through kinetic and balance equations.  相似文献   
956.
Chromatin condensation begins as the multilayered structure (MLS) in Phaeoceros reaches its maximally structured differentiation. As nuclear elongation and chromatin condensation proceed, the S2–4 strata disappear, and the nuclear beak extends between the S1 and the nearly spherical anterior mitochondrion. In a mature sperm the mitochondrion is elongate and lies completely anterior to the blunt front end of the nucleus. The 12 S1 tubules extend over the anterior mitochondrion and nucleus, but their number becomes reduced to five at the level where the nucleus' midportion is constricted. The anterior ends of the S1 tubules lie embedded in a rather conical osmiophilic crest. Flagellar insertion is restricted to the extreme anterior tip of the S1 tubules. The locomotory apparatus in Phaeoceros is compared with that of other bryophytes.  相似文献   
957.
958.
Fibroblasts cultured from the skin of four mentally retarded patients with argininosuccinic aciduria were markedly deficient in argininosuccinase activity.This work was supported by U.S. Public Health Service grants NB-05096 and CA-04670.  相似文献   
959.
960.
Bioprocess engineering at present concentrates on the enormous problems in the environment. What is therefore needed is a sound methodology, which should be based on the interactions between the physiology of biological reaction networks and physical processes in the environment and which should be an analogy to bioreactor performance. The conventional methodology is empirically oriented, using pilot plant data for the experimental estimates of process economics, where all further details are elucidated following the mechanistic approach on the microscopic level based on assumed mechanisms (causalities). According to the new view, the new systems-based methodology uses mathematical models as approximations and includes all the interactions. Pilot plant data are needed for model falsification, using analogies on the formal macroscopic level. Bioreactor scale-up as one application is a more rapid procedure of reasonable accuracy, where both the biokinetics as well as the fluid dynamics are quantified using formal macroscopic analogies. Model consistency and plausibility are the basic criteria when using model computer simulations as a decisive aid, while experiments lose their central role and are on longer the basis for evaluating the scientific work; they are simply the basis of the researcher's intuition. Another typical feature of complex systems is that model parameters are interdependent. The final decisive fact will be the mental experiment (“thinking” with the left and right side of the brain), which can be supported using computer simulations. This evolutionary interplay between the three realities of thinking, experimenting and simulating leads to a holistic progress towards the better understanding of highly complex systems. It offers the solution to the problems, which is needed in future.  相似文献   
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