Compiling real-time programs with timing constraint refinement andstructural code motion

We present a programming language called TCEL (Time-Constrained Event Language), whose semantics are based on time-constrained relationships between observable events. Such a semantics infers only those timing constraints necessary to achieve real-time correctness, without overconstraining the system. Moreover, an optimizing compiler can exploit this looser semantics to help tune the code, so that its worst-case execution time is consistent with its real-time requirements. In this paper we describe such a transformation system, which works in two phases. First, the TCEL source code is translated into an intermediate representation. Then an instruction-scheduling algorithm rearranges selected unobservable operations and synthesizes tasks guaranteed to respect the original event-based constraints     

Antihyperglycemic activities of cryptolepine analogues: an ethnobotanical lead structure isolated from Cryptolepis sanguinolenta

Cryptolepine (1) is a rare example of a natural product whose synthesis was reported prior to its isolation from nature. In the previous paper we reported the discovery of cryptolepine's antihyperglycemic properties. As part of a medicinal chemistry program designed to optimize natural product lead structures originating from our ethnobotanical and ethnomedical field research, a series of substituted and heterosubstituted cryptolepine analogues was synthesized. Antihyperglycemic activity was measured in vitro and in an NIDDM mouse model to generate the first structure-bioactivity study about the cryptolepine nucleus.     

Structures and antimicrobial activity of peniophorin A and B, two polyacetylenic antibiotics from Peniophora affinis Burt

Two polyacetylenic antibiotics, peniophorin A and B, have been isolated from a strain of Peniophora affinis. Both have antibacterial and antifungal activity, but B is 3 to 20 times more active than A. Gram-positive cocci and a strain of Proteus vulgaris were especially susceptible to these two antibiotics. Both peniophorins contained an aromatic ring; B was an acid, and A was neutral. Peniophorin B was shown to be 2-(1-oxo-2,4-pentadiynl)phenyl acetic acid. The structure of A was only partially elucidated; it is suspected to be 6-[2-(1-oxo-2,4-pentadiynl)phenyl]5-methoxy-3-oxo-4-hexene-1-ol.     

5.1--Use of an oscillating laser as a heterodyne receiver preamplifier

In this paper the results of a study of the amplification characteristics of lasers for signals injected near their frequencies of oscillation are reported. An approximate theoretical treatment is given which indicates that substantial amplification will occur under conditions for which the anisotropy of the laser cavity is small, the polarization state of the injected signal is orthogonal to that of the primary oscillation, and the two signals are critically coupled. For like polarization of these signals, postive amplification occurs only for substantially reduced laser excitation or increased cavity loss. The experimental observations are in qualitative agreement with the theoretical predictions with gains as high as 600 having been observed for orthogonal polarizations near critical coupling. The optical bandwidth appears to be at least several MHz.     

Protection against UVA damage and effects on neutrophil-derived reactive oxygen species by beta-carotene

OBJECTIVE: Phagocyte-derived reactive oxygen species (ROS) are involved in microbicidal activities as well as in tissue damage at sites of inflammation. Carotenoids play an important function in protecting cells from oxidant damage. We investigated the in vitro and in vivo effect of 13-cis and 9-cis-beta-carotene on human neutrophils. METHODS: Neutrophils from healthy donors in the presence of 0.25 mumol/L-1 mumol/l beta-carotene and from subjects under beta-carotene supplementation and UVA or UVA/B exposure were stimulated by opsonized zymosan and the generation of ROS was measured by electron spin resonance spectroscopy. RESULTS: Our in vitro results show different effects of the two isomers on stimulated neutrophils. 9-cis-beta-carotene did not produce any change, whereas 13-cis-beta-carotene significantly and concentration-dependent inhibited the ROS generation by stimulated neutrophils. Further, in a controlled study, we were able to demonstrate an in vivo protective effect of beta-carotene on neutrophils against UVA damage by beta-carotene supplemented subjects.     

Quality assurance of serial tomotherapy for head and neck patient treatments

PURPOSE: A commercial serial tomotherapy intensity-modulated radiation therapy (IMRT) treatment planning (Peacock, NOMOS Corp., Sewickley, PA) and delivery system is in clinical use. The dose distributions are highly conformal, with large dose gradients often surrounding critical structures, and require accurate localization and dose delivery. Accelerator and patient-specific quality assurance (QA) procedures have been developed that address the localization, normalization, and delivery of the IMRT dose distributions. METHODS AND MATERIALS: The dose distribution delivered by serial tomotherapy is highly sensitive to the accuracy of the longitudinal couch motion. There is also an unknown sensitivity of the dose distribution on the dynamic mutlileaf collimator alignment. QA procedures were implemented that assess these geometric parameters. Evaluations of patient positioning accuracy and stability were conducted by exposing portal films before (single exposure) and after (single or double exposure) treatments. The films were acquired with sequential exposures using the largest available fixed multileaf portal (3.36 x 20 cm2). Comparison was made against digitally reconstructed radiographs generated using independent software and appropriate beam geometries. The delivered dose was verified using homogeneous cubic phantoms. Radiographic film was used to determine the localization accuracy of the delivered isodose distributions, and ionization chambers and thermoluminescent dosimetry (TLD) chips were used to verify absolute dose at selected points. Ionization chamber measurements were confined to the target dose regions and TLD measurements were obtained throughout the irradiated volumes. Because many more TLD measurements were made, a statistical evaluation of the measured-to-calculated dose ratio was possible. RESULTS: The accelerator QA techniques provided adequate monitoring of the geometric patient movement and dynamic multileaf collimator alignment and positional stability. The absolute delivered dose as measured with the ionization chamber varied from 0.94 to 0.98. Based on these measurements, the delivered monitor units for both subsequent QA measurements and patient treatments were adjusted by the ratio of measured to calculated dose. TLD measurements showed agreement, on average, with the ionization chamber measurements. The distribution of TLD measurements in the high-dose regions indicated that measured doses agreed within 4.2% standard deviation of the calculated doses. In the low-dose regions, the measured doses were on average 5% greater than the calculated doses, due to a lack of leakage dose in the dose calculation algorithm. CONCLUSIONS: The QA system provided adequate determination of the geometric and dosimetric quantities involved in the use of IMRT for the head and neck. Ionization chamber and TLD measurements provided accurate determination of the absolute delivered dose throughout target volumes and critical structures, and radiographic film yielded precise dose distribution localization verification. Portal film acquisition and subsequent portal film analysis using 3.36 x 20 cm2 portals proved useful in the evaluation of patient immobilization quality. Adequate bony landmarks were imaged when carefully selected portals were used.     

TMD warning sign: cephalometrics

The significance of predisposing factors to TMD is quite evident when considering the prevalence of orthodontic relapse and with the occurrence of TMD related symptoms observed in previously treated orthodontic patients. In using the Modified Sassouni Plus Cephalometric Analysis, the clinician now possesses an invaluable tool that is readily available without adding to the examination expense. The invaluable information gained from cephalometric evaluation should not, however, be used to replace other diagnostic TMJ radiographs. If a joint problem is suspected, one should follow the normal protocol for the examination of the temporomandibular joints.     

Effect of prostaglandin endoperoxide analogue on canine renal function, hemodynamics and renin release

We studied the effect of a stable, cyclic ether analogue of prostaglandin endoperoxide (EPA) on canine renal function, hemodynamics, and renin release. Infusion of EPA into one renal artery decreased renal blood flow in a dose dependent manner. At a dose of 10(-7) g/kg/min the renal blood flow decreased from a baseline of 384 to 267 ml/min/100 g. This flow decrease was unaltered by phentolamine and saralasin, but was potentiated by prior treatment with indomethacin. Urine flow, glomerular filtration rate, sodium, and potassium excretion all decreased in a dose dependent manner; however, neigher fractional excretion of sodium nor free water clearance showed any significant change, making direct tubular effects of EPA unlikely. EPA caused a significant increase in renin release that was completely blocked by prior treatment with indomethacin. We conclude that EPA is a potent renal vasoconstrictor and that this vasoconstriction is responsible for the renal functional changes observed. Renin release is not a direct effect of EPA but probably is secondary to an endogenously generated prostaglandin. Since EPA mimics the effects of natural prostaglandin endoperoxides on smooth muscle in vitro, it is possible that prostaglandin endoperoxide-induced vasoconstriction in vivo modulates the effects of their vasodilatory products, prostaglandin E2 and I2.     

Drug deaths

In the Federal Republic of Germany there exist no statistical datas concerning death related to drug dependence until now. We propose to define death in connexion with drug dependence as the death of a drug dependent person caused by direct or indirect effect of the drug used. We first report on several international investigations; then the results of our own investigation in 40 cases of death in connexion with drug dependence in the district of Nordbaden are presented in detail. As a result it seems necessary to register drug dependent persons and to isolate those who are resistent to any therapy and thus represent a focus for further expansion of drug consuming.