(n.) The shadow cast, in an eclipse, where the light is partly, but not wholly, cut off by the intervening body; the space of partial illumination between the umbra, or perfect shadow, on all sides, and the full light.
(n.) The part of a picture where the shade imperceptibly blends with the light.
Example Sentences:
(1) Our analysis showed that the interpolation errors are proportional to the curvature of the dose distribution and are relatively high in regions on either side of, but not including, the steepest part of the penumbra.
(2) Analysis of the penumbra width of cross dose distributions, as a function of field sizes, allowed us to postulate that the dmax shift could be due to the phantom scattered photons, which in turn were generated by the collimator scattered photons.
(3) If true, this is the first demonstration of the ischemic penumbra by MR imaging and may reflect our use of Wistar rats, a new image analysis technique, and ultra-high resolution MR imaging.
(4) The combination for this applicator of sharp penumbra and low out-of-field dose leads to reduced lung and opposite breast doses.
(5) An extracellular acidosis that occurs in the penumbra zone was investigated in vitro as to its role in the formation of cytotoxic cell swelling.
(6) The ischemic thresholds for the initial increase in CMRG and the complete depletion of ATP content represent the metabolic equivalent of the penumbra zone and provide a basis for the evaluation of therapeutic procedures for the treatment of stroke.
(7) If the entire cross-section is blocked, the point will be in the umbra of the shadow; if only a portion of the light is blocked, the point will be in the penumbra of the shadow.
(8) The mechanisms involved in this sequence of events and the role of pH changes in the development of the so-called "ischaemic penumbra" are discussed.
(9) In the light of these findings, we suggest that use of a selective antagonist of LTs may be helpful in reducing the ischemic penumbra during acute cerebral ischemia by controlling the vasogenic edema.
(10) Opening the hinge adjustment restores field flatness, without changing penumbra or the inverse square law behavior of the teletherapy unit.
(11) The area of "penumbra" could be estimated in regions with CBF value just above this threshold.
(12) In the penumbra zone, comparable trends were noted in OER and CMRO2 but the difference in the changes between the two groups did not reach statistical significance.
(13) The agreement is within experimental errors both in the penumbra region and along the central ray of the asymmetric field.
(14) These results confirm the concept of a metabolic penumbra.
(15) These wedges were designed to increase the penumbra width at the field junction from about 1.5 to about 3.5 cm, to achieve dose uniformity.
(16) These studies suggest that 1) the expression of 72-kd heat-shock protein in neurons precedes the development of ischemic cellular alterations detectable by conventional hematoxylin and eosin light microscopy methods; 2) there is a hierarchy of cell types and anatomic sites that express 72-kd heat-shock protein, and this hierarchy reflects cellular and anatomic vulnerability to ischemic cell damage; and 3) 72-kd heat-shock protein induction in neurons bordering a necrotic ischemic core may be the morphological equivalent of the ischemic penumbra.
(17) While within the penumbra, some direct sunlight falls on the Moon but little darkening of the disc will be noticed until a few minutes before the Moon begins to enter the umbra at 19:23.
(18) Measurements with the diode interfaced to an X-Y recorder required only a fraction of the time required with the chambers, minimizing error due to change in machine output, and permitted resolution of isodose lines in the penumbra.
(19) A typical spot has a central dark umbra, surrounded by a lighter penumbra.
(20) The rate in the penumbra differed (P = .01) from that in the predicted low-dose region, where scotoma did not increase with time.
Uncertainly
Definition:
(adv.) In an uncertain manner.
Example Sentences:
(1) However, the mechanism of the inhibitory action is still somewhat uncertain.
(2) Of course the job is not done and we will continue to remain vigilant to all risks, particularly when the global economic situation is so uncertain,” the chancellor said in a statement.
(3) The functional significance of these early changes in the nodal region is uncertain.
(4) Preservation of dopaminergic and H1 neurotransmission, probably within the blood barrier, is needed to allow the neuroendocrine transduction of cholinergic inputs, whereas the role of 5-HT neurotransmission remains uncertain.
(5) The nature of these infiltrative foci remains uncertain; however, they are unlikely to have been of neoplastic origin and may be due to interleukin-2-induced lymphocytic infiltration.
(6) Whether or not any alteration in disease progression will accrue from demonstrated local downstaging is, of course, uncertain.
(7) Similarly, it appears that acute hydronephrosis or worsening of an existing hydronephrosis has been somewhat overlooked as a possible cause of uncertain abdominal pain during pregnancy.
(8) In 11 patients, the electrophysiological mechanism remained uncertain.
(9) The nature of the cystatin C-immunoreactive substance in some of these vascular lesions is uncertain, but it might conceivably play an additional important role in the pathogenesis of brain hemorrhage in these cases.
(10) The mechanism of action is still uncertain but it is believed by some workers to be similar to that of a beta-adrenergic stimulator.
(11) Assays of drug levels in blood and of other biochemical characteristics of psychiatric patients are being proposed for clinical application, although their utility in practice remains uncertain.
(12) In 26 patients, including the two reported here, etiology was uncertain (idiopathic aneurysm of the left ventricle) in as much as malformation or an infectious disease might have been the underlying cause.
(13) Instead of inevitable defeat there is uncertain cop-out.
(14) The aetiology remains at present uncertain and therefore rational therapeutic strategies are difficult to plan.
(15) It was concluded that (1) there is a group of patients whose histories of poliomyelitis are uncertain, and (2) the lack of clear evidence for previous denervation after extensive electrodiagnostic testing is a valid means for excluding the diagnosis of postpoliomyelitis syndrome.
(16) Although approximately 24,000 adolescents were questioned, the investigations together provide an uncertain picture of the habits as these are not representative for Danish adolescents.
(17) McCall said the outlook remained uncertain: “The economic and operating environment remains uncertain, following the high levels of disruption and more recently the UK’s referendum decision to leave the EU, as well as the recent events in Turkey and Nice, which have affected consumer confidence.
(18) The significance of this event is uncertain; cleaved NGF demonstrates bioactivity and no function has been attributed to the octapeptide produced (NGF-OP; Ser-Ser-Thr-His-Pro-Val-Phe-His).
(19) While the histogenesis of these tumors remain uncertain, it is necessary to recognize that these aggressive neoplasms may occur primarily in the skin.
(20) Estimates of the number of eventual TA-AIDS cases to be seen are considerably more uncertain and require additional assumptions about the incubation distribution.