(n.) The act or process of penetrating, piercing, or entering; also, the act of mentally penetrating into, or comprehending, anything difficult.
(n.) Acuteness; insight; sharp discoverment; sagacity; as, a person of singular penetration.
Example Sentences:
(1) The penetration of (22)Na was not prevented by the presence of metabolic inhibitors or by 500 mm NaCl in the suspending medium.
(2) Content of cyclic nucleoside monophosphates was decreased in all the eye tissues in experimental toxico-allergic uveitis as well as penetration of cAMP into the fluid of anterior chamber of the eye.
(3) After four years of existence, many evaluations were able to show the qualities of this system regarding root canal penetration, cleaning and shaping.
(4) testosterone, fentanyl, nicotine) may ultimately be administered in this way, important questions pertaining to pharmacology (tolerance), toxicity (irritation, sensitisation) and dose sufficiency (penetration enhancement) remain.
(5) The automatic half of both the motor which advances the trepan as well as the second motor which rotates the trepan is triggered by the sudden change in electrical resistance between the trepan and the patient's internal body fluid, at the final stage of penetration.
(6) Thus, although ferric-enterochelin cannot penetrate the cell surface from outside, the complex that is formed within the envelope is transported normally into the cell.
(7) Major limitations of the conventional sperm penetration assay are the inability to assess several aspects of sperm function (zona binding and penetration) and the absence of human ovulatory products known to influence fertilization.
(8) The cercaria, microcercous in type, is liberated and actively penetrates a second terrestrial pulmonate where development to the free metacercarial stage takes place in the pericardial cavity.
(9) The incomplete penetrance of the neoplastic phenotype and the monoclonality of lymphoid tumors suggest that tumor formation in v-fps mice requires genetic or epigenetic events in addition to expression of the P130gag-fps protein-tyrosine kinase.
(10) All of these factors make morbidity and mortality associated with penetrating injuries low.
(11) The treatment led to decreased spinnbarkeit, arborization and sperum penetration in the cervical mucus.
(12) The penetration coefficient, determined by the surface tension, contact angle and viscosity, is a measure of the ability of a liquid to penetrate into a capillary space, such as interproximal regions, gingival pockets and pores.
(13) The rational surgical methods of treatment in 85 patients with suppurative hepatic echinococcosis penetrating into the abdomen cavity are presented.
(14) This apparent lack of centrosomal staining was not due to problems associated with penetration of the antibody probes, since staining adjacent to and within the centriolar cylinder was observed when phosphoprotein antigens recognized by the MPM-2 antibody were localized.
(15) Both types of oral cleft, cleft palate (CP) and cleft lip with or without CP (CLP), segregate in these families together with lower lip pits or fistulae in an autosomal dominant mode with high penetrance estimated to be K = .89 and .99 by different methods.
(16) Cefuzoname seems to be among the middle ranks of beta-lactam agents as far as penetration rate is concerned; however, when its potent antibacterial activity and broad spectrum are taken into account, the concentrations in CSF in patients with meningitis seem worth examining.
(17) The time of sperm penetration in the mouse eggs, however, was delayed for one-half to one hour when ejaculated sperm were used.
(18) Enzymatic lability does not, however, play as important a role as lipophilicity in the corneal and conjunctival penetration of cycloalkyl and aryl ester prodrugs.
(19) No infection threads were found to penetrate either root hairs or the nodule cells.
(20) Kinetic studies showed that significant inhibition of virus production occurred when the inhibitor was added to infected cultures up to 5 h after virus penetration.
Polyspermy
Definition:
(n.) Fullness of sperm, or seed; the passage of more than one spermatozoon into the vitellus in the impregnation of the ovum.
Example Sentences:
(1) The relation of these layers to the movements of the spermatozoon, to the activation of the egg, to the block to polyspermy, and to each other are discussed.
(2) The incidence of polyspermy, which did not exceed 5% in Series I and reached 58% in Series II, was dependent on the genotype of both gametes.
(3) Microscopic examinations of eggs stained with aceto-orcein or the DNA fluorochrome bisbenzimide and direct observations on isolated sperm aster complexes show that halothane induces polyspermy (multiple sperm entry) when present at fertilization.
(4) The purine inhibits the detachment of the vitelline layer from the sea-urchin egg plasma membrane after fertilization and this effect leads to polyspermy.
(5) The eggs of the surf clam Spisula solidissima have a built-in mechanism that prevents polyspermy: the eggs show a 70 percent decrease in sperm receptivity 5 seconds after fertilization, and become completely resistant to sperm by 15 seconds.
(6) When inseminated with sperm of the newt, Cynops pyrrhogaster, mature Bufo oocytes exhibited polyspermy accompanied by a gradual hyperpolarization and a slowly developing positive plateau, without the fast spike that occurs in self-species fertilization.
(7) The zona pellucida block to polyspermy is very effective since only one sperm penetrated the zona pellucida in 72.8% of the 876 fertilized eggs examined.
(8) The fertilizing capacity of sperm was evaluated after 0, 24, and 30 h of incubation by adding oocytes to the culture and determining the incidences of fertilization and polyspermy.
(9) Thus, universal roles of zona hardening in the block to polyspermy and in oviductal interaction with embryos have been discounted.
(10) The change in distribution of labelled macromolecules on the zona surface may be a prerequisite for successful sperm-zona binding and the specific association of labelled glycoconjugates in the region of the egg plasma membrane may be involved in the preparation of the egg surface for sperm-egg interactions involving cortical granule exocytosis and the block to polyspermy.
(11) Correction of polyspermy through pronucleus extraction in the absence of membrane relaxants was applied to 25 polyspermic human zygotes.
(12) The present study was undertaken to determine what type(s) of block(s) to polyspermy exist in Chaetopterus.
(13) As a step toward defining in molecular terms the sperm-triggered block to polyspermy reaction established by the egg at fertilization, vitelline (VE) and fertilization (FE) envelopes were isolated from eggs of the Sounth African clawed toad Xenopus laevis and some of their physicochemical properties determined.
(14) In A. callosa, fertilization in low Na+ SW causes a 60% decline in enzyme release and a similar increase in the number of sperm remaining on the VC at 4 min as well as a great increase in polyspermy.
(15) It is proposed that the hyperpolarization of the egg membrane in response to fertilization constitutes a long-lasting electrical block to polyspermy in crab eggs.
(16) The consequences of interactions between porcine sperm, eggs, and oviduct cells before and during fertilization in vitro (IVF) has been examined with particular reference to the block to polyspermy.
(17) This block to polyspermy is inactivated by GlcNAc (2mM) or 150 mM-Na+ (choline substituted) SW.
(18) Zona cutting was associated with a low loss of oocytes (less than 1%), no increase in polyspermy and normal development in vitro and in vivo after fertilization.
(19) Comparisons with data from animals, and measures aimed at preventing polyspermy are suggested.
(20) Polyspermy increased significantly with 10 mM GR in oocyte incubation medium.