(n.) A carpentry obstruction, stockade, or other obstacle made in a passage in order to stop an enemy.
(n.) A fortress or fortified town, on the frontier of a country, commanding an avenue of approach.
(n.) A fence or railing to mark the limits of a place, or to keep back a crowd.
(n.) An any obstruction; anything which hinders approach or attack.
(n.) Any limit or boundary; a line of separation.
Example Sentences:
(1) Here we have asked whether protection from blood-borne antigens afforded by the blood-brain barrier is related to the lack of MHC expression.
(2) We conclude that chloramphenicol resistance encoded by Tn1696 is due to a permeability barrier and hypothesize that the gene from P. aeruginosa may share a common ancestral origin with these genes from other gram-negative organisms.
(3) The findings clearly reveal that only the Sertoli-Sertoli junctional site forms a restrictive barrier.
(4) This suggests that a physiological mechanism exists which can increase the barrier pressure to gastrooesophageal reflux during periods of active secretion of the stomach, as occurs in digestion.
(5) Comparison of the 50% binding concentrations of the compounds for the various PBPs of the five strains with their antibacterial activity indicates that the different antibiotics are excluded to a greater or lesser degree by the outer membrane permeability barrier and that the exclusion is most pronounced in P. aeruginosa.
(6) 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.
(7) Their levels in urine are a useful indicator of the integrity of membrane barriers of the kidney glomerular capillary wall.
(8) The IgG index (formula: see text) corrects for the influence of serum protein abnormalities as well as a bloodbrain barrier damage and is, therefore, a better measure for the presence of an IgG elevation in CSF due to IgG synthesis, when compared with other IgG quotients commonly used.
(9) In the far east is the arid, depressed country leading down Hell’s Canyon, which bottoms out at the Snake River, which the wolves crossed when they moved from Idaho, and which they now treat more as a crosswalk than a barrier.
(10) No signs of the blood-brain barrier disruption were observed.
(11) Although no anatomical 'barrier' has been described, it has been suggested that the gel mucus and epithelial phospholipids are constituents.
(12) Despite their wide dispersion, Vmax and the stereological determinations correlated strongly at 2 mo of age, confirming that Vmax is a robust indicator of the surface area of the air-blood barrier.
(13) Developmental changes are delineated, with particular reference to recent work on the ovine blood-brain barrier.
(14) Features of barrier island physiography and ecology were studied relative to selective bait deployment and site biosecurity.
(15) This study sought to determine if and why barriers to the over-the-counter purchase of syringes in the St. Louis metropolitan area might exist, given that no ordinance prohibits such a sale there.
(16) It is suggested that the intercalated disc functioned as a barrier to the freezing process.
(17) To explain some of these results a theoretical model is presented to demonstrate that while short circuiting can block the passive ionic movement, it will cause an increase in the energy consumption of the system and introduce certain important changes in the ionic barriers and e.m.fs.
(18) Our results show that paramagnetic enhancement with T1-weighted imaging adds specificity and enables rapid assessment of abnormalities of the blood-brain barrier.
(19) A functional impairment of the amino acid transport systems at the level of the blood-brain barrier seems to play a crucial role in causing deleterious modifications of the synaptic neurotransmission in the central nervous system.
(20) There was a significant correlation between the lesion index and the PD reduction, although the integrity of the resting gastric mucosal barrier remained unaltered.
Obstacle
Definition:
(v.) That which stands in the way, or opposes; anything that hinders progress; a hindrance; an obstruction, physical or moral.
Example Sentences:
(1) Since the first is balked by the obstacle of deficit reduction, emphasis has turned to the second.
(2) If women psychiatrists are to fill some of the positions in Departments of Psychiatry, which will fall vacant over the next decade, much more attention must be paid to eliminating or diminishing the multiple obstacles for women who chose a career in academic psychiatry.
(3) Counselors who serve pregnant US teens face a number of obstacles in communicating adoption as a positive alternative.
(4) A major obstacle to the characterization of the latter two mechanisms has been the lack of suitable model systems expressing only a single nucleoside transport activity.
(5) These observations suggest that refractive anomalies such as anisometropia that limit high frequency spatial resolution and binocular integration can present a major obstacle to the postnatal development of binocular vision.
(6) The initiation of clinical trials on islet transplantation as a possible therapeutic approach for human diabetes had been blocked by 2 major obstacles.
(7) Venous ectasias and varices which can be encountered, associated with DVA constitute an acquired feature in relation to a venous outlet obstacle.
(8) Despite these obstacles, new technologies, coupled with educational efforts, should allow the computer to emerge as a crucial aid to clinicians in the decade ahead.
(9) Yet experience has disclosed an obstacle to understanding the relationship between cervical cancer and OC use--cervical cancer may be caused by the human papilloma virus transmitted by sexual intercourse.
(10) In this paper something is given of their evolution, diversity, aims and activities; and of the important role they now play in many instances, as well as some of the obstacles to collaboration, co-ordination and integration at different levels of operation--internationally, nationally and locally.
(11) It is no obstacle to perform pre- and postoperative radio- and chemotherapy.
(12) Obstacles to successful treatment include an erratic schedule, mistrust of authority, and uncooperative or aggressive behavior.
(13) One of the main obstacles for the introduction of PCR method to identify HIV1 proviral DNA in routine diagnostic laboratories is the use of radiolabelled oligodeoxynucleotide probes.
(14) Digital culture has hardly helped, adding revenge porn, trolls and stranger-shaming to the list of uncomfortable modern obstacles.
(15) She feared her chances of being offered a place would be diminished by a Brexit vote, and the practical considerations like a visa and funding would be more of an obstacle.
(16) It goes without saying that this won't be easy to achieve, and there are many obstacles to be overcome.
(17) Armstrong recognised no obstacle to his ambitions – not morality, not the law.
(18) Where foreign policy and defence are concerned, Britain’s desire to be taken very seriously is the chief obstacle to it being taken more seriously.
(19) The presence of calcifications within the thyroid cartilage is the major obstacle to US imaging of the larynx and is directly related to age; indeed, only 40% of subjects can be examined at the age of 70.
(20) Facebook Twitter Pinterest Britain needs to talk about the R-word: racism It is also a wakeup call to those who recognise racism only when it is played out like a scene from Django Unchained , those who think that racism has to be some vulgar incident perpetrated only by the backward, ignorant and poorly educated, those who believe that racism has to be an act, rather than a complicated and intangible framework that sets up obstacles.