8 research outputs found
The transformation of tryptophan to aspartic acid in peptides
The tryptophan side chain is transformed by in situ generated ruthenium(VIII), to that of aspartic acid, in good yields; a multi-step degradation sequence is suggested on the basis of the transformations of tetrahydrocarbazole to adipic acid, valine to isobutyric acid, and phenylalanine to phenylacetic acid
Oxidative transformations of coded aromatic amino acids with 4-t-butyl lodylbenzene
A study of the action of 4-t-butyl iodylbenzene (1) on the side chains of the four coded aromatic amino acids has shown that tryptophan is transformed to kynurenine, arising from (1) in the role of an ozone equivalent, histidien to Îł-formamido glutamine, by pathways similar to those delineated for histidine catabolism, tyrosine to 3,4-dihydroxy-phenylalanine quinone, and phenylalanine recovered unchanged
Figure 1: Layers of system abstraction
This paper describes the general problems in providing system software support for multimedia applications. We specifically focus on applications which have digital continuous media (DCM) I/O components, and the type of support that must be provided by the network software and operating system. DCM applications have large bandwidth and low delay requirements. We discuss network software support to meet these requirements, such as resource reservation schemes based on parameterized requests for some level of quality of service. Most likely, DCM communications will be long-lived, which suggests that connections are the appropriate network construct for such communications. Regarding the operating system, we describe issues of real-time resource scheduling, synchronization of processes and temporally related DCM flows, shared memory, and the need for a modular, uniform I/O abstraction. Finally, we present design principles based on the concepts of moving processes to data and separating d..
The chemical simulation of the "ATP-Imidazole" cycle
The synthetic strategy inherent in the "ATP-Imidazole" cycle and centred around the vicinal disposition of -NH2 and -CONH2 functions, has been demonstrated with anthranilamide (2) and 1-benzyl-5-aminoimidazole-4-carboxamide (1) as regeneratable carriers involving specifically N-alkylated quinazolin-4-ones, hypoxanthines and adenines, as key intermediates. The isolation and characterization of the enamine (22) coupled with other observations has made it possible to rationalize the pathways involved in these cyclic operations. The practical utility of the synthetic strategy using regeneratable carriers has been illustrated with the synthesis of a range of 1,5-disubstituted imidazoles. whilst pathways leading to specific N-alkylation in the Natural cycle and in simulation studies are comparable, the subsequent events take place in a reverse order, primarily because of the divergence in the hydrolytic profile of the alkylated substrates. The action of dilute alkali on 3-alkylated quinazolin-4-ones leads to 2-3 rather than 3-4 bond rupture. Endeavours to promote the latter path, by blocking the 2 position gave unexpected results. 2-Methyl-3-phenacyl quinazolin-4-one gave with dilute alkali the novel aromatic tricyclic system (32) from trans-annular cyclization. On the other hand, the 2-blocked 3-benzamido quinazolin-4-ones (33) and (34) gave triazoles (35) and (36) arising from the desired 3-4 rupture followed by cyclization initiated by the resulting amidine unit. 2-Phenyl-3-benzamidoquinazolin-4-one (34) with distilled water at 200°C gave a number of products which have been identified and their formation explained
Operating System and Window System Research for Distributed Multi-media Applications: A Status Report
We are currently researching general operating system and window system mechanisms necessary to support distributed multi-media applications, specifically applications which have audio and video I/O components. Digital audio and motion video I/O have such high bandwidth and low delay requirements that special underlying software support mechanisms are needed. Our goal is to determine how functionality is divided between the window system and the operating system, and what types of mechanisms support this functionality. As a first step toward achieving this goal, we are building a distributed real-time I/O-intensive application: multi-media conferencing. These conferences are between geographically distributed users on personal workstations connected by high-speed networks. These conferences include the presentation of real-time digital audio and video I/O of the participants so that they may effectively collaborate despite their physical separation. From the experience we gain by buil..
Network and Operating System Support for Multimedia Applications
This paper describes the general problems in providing system software support for multimedia applications. We specifically focus on applications which have digital continuous media (DCM) I/O components, and the type of support that must be provided by the network software and operating system. DCM applications have large bandwidth and low delay requirements. We discuss network software support to meet these requirements, such as resource reservation schemes based on parameterized requests for some level of quality of service. Most likely, DCM communications will be long-lived, which suggests that connections are the appropriate network construct for such communications. Regarding the operating system, we describe issues of real-time resource scheduling, synchronization of processes and temporally related DCM flows, shared memory, and the need for a modular, uniform I/O abstraction. Finally, we present design principles based on the concepts of moving processes to data and separating d..
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Accrual to Clinical Trials (ACT): A Clinical and Translational Science Award Consortium Network.
The Accrual to Clinical Trials (ACT) network is a federated network of sites from the National Clinical and Translational Science Award (CTSA) Consortium that has been created to significantly increase participant accrual to multi-site clinical trials. The ACT network represents an unprecedented collaboration among diverse CTSA sites. The network has created governance and regulatory frameworks and a common data model to harmonize electronic health record (EHR) data, and deployed a set of Informatics for Integrating Biology and the Bedside (i2b2) data repositories that are linked by the Shared Health Research Information Network (SHRINE) platform. It provides investigators the ability to query the network in real time and to obtain aggregate counts of patients who meet clinical trial inclusion and exclusion criteria from sites across the United States. The ACT network infrastructure provides a basis for cohort discovery and for developing new informatics tools to identify and recruit participants for multi-site clinical trials
International Nosocomial Infection Control Consortiu (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module
We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care–associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line–associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN