What's the difference between atom and nucleus?

Atom


Definition:

  • (n.) An ultimate indivisible particle of matter.
  • (n.) An ultimate particle of matter not necessarily indivisible; a molecule.
  • (n.) A constituent particle of matter, or a molecule supposed to be made up of subordinate particles.
  • (n.) The smallest particle of matter that can enter into combination; one of the elementary constituents of a molecule.
  • (n.) Anything extremely small; a particle; a whit.
  • (v. t.) To reduce to atoms.

Example Sentences:

  • (1) It has been conformed that catalase from bovine liver eliminates only the pro R hydrogen atom from ethanol.
  • (2) The results demonstrated that K2PtCl4 was bound to a greater degree than CDDP in this system with 3-5 and 1-2 platinum atoms respectively, bound per transferrin molecule.
  • (3) Richard Bull Woodbridge, Suffolk • Why does Britain need Chinese money to build a new atomic generator ( Letters , 20 October)?
  • (4) The bond distances of Cu to Cl(1), Cl(2), N(3) and N(3') atoms are 2.299 (1), 2.267 (1), 1.985 (4) and 1.996 (3) A, respectively.
  • (5) The common atoms of the [3Fe-4S] and [4Fe-4S] cores agree within 0.1 A; the three common cysteinyl S gamma ligand atoms agree within 0.25 A.
  • (6) This result was confirmed by atomic absorption spectroscopy, which indicated a stoicheiometry for copper and manganese of approx.
  • (7) The inter-molecular similarity measure used is the number of atoms in the 3-D common substructure (CS) between the two molecules which are being compared.
  • (8) The risks are determined, mainly by expert committees, from the steadily growing information on exposed human populations, especially the survivors of the atomic bombs dropped in Japan in 1945.
  • (9) All N and O atoms except N(3) and O(4') participate in a three-dimensional hydrogen-bonding system.
  • (10) This suggestion is supported by EPR studies, which show that the iron atoms in Fe(III)L-globin are in two low electronic states.
  • (11) The molar refractivity has been shown to be a superior parameter for the description of the activity of sulphonamides than the sum of electronegativities of atoms making up a heterocyclic substituent in the sulphonamide molecule and molecular weight of the substituent.
  • (12) Binding to HSA occurs primarily with the imidazolidine and thiazolidine groups of levamisole as it has been demonstrated by selective changes in the relaxation times and the chemical shifts of the protons attached to the carbon atoms.
  • (13) Each repeat unit contains thirty amino acids and is thought to bind a zinc atom using two cysteines and two histidines as ligands.
  • (14) NADP+ bound at the C8 atom in the adenine moiety proved to be the most efficient ligand whereas that bound at the C3 atom of the ribose moiety was relatively inefficient.
  • (15) This structure is further characterized by approaches of both the carbonyl and the furan O atoms to ring H atoms with separations which are slightly less than the sum of the relevant van der Waals radii.
  • (16) The magnitude of improvement achieved is dependent upon field size, SSD, the atomic number of the foil material, and foil thickness.
  • (17) For the liver enzyme, the logarithm of the inhibition constant was linearly related to the number of carbon atoms in the saturated fatty acids whereas the muscle enzyme, which was generally more strongly inhibited, showed a nonlinear dependence.
  • (18) Results obtained from a such study are here compared with levels obtained from a comparative determination of the metals in the mosses by three other techniques: Differential pulse anodic stripping voltammetry (DPASV), Direct current plasma (atomic emission) spectroscopy (DCPS) and X-ray fluorescence (XRF) spectroscopy.
  • (19) It was hypothesized that the observed activity variation of the paracetamol analogues was based on the relative abilities of these compounds to undergo H atom loss at the phenolic oxygen, and on the relative stabilities of the resulting free-radical species.
  • (20) The resulting family of structures has a mean backbone rmsd of 0.63 A (N, C alpha, C', O atoms), excluding the segments containing residues 45-59 and 84-88.

Nucleus


Definition:

  • (n.) A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively.
  • (n.) The body or the head of a comet.
  • (n.) An incipient ovule of soft cellular tissue.
  • (n.) A whole seed, as contained within the seed coats.
  • (n.) A body, usually spheroidal, in a cell or a protozoan, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see Nucleoplasm). See Cell division, under Division.
  • (n.) The tip, or earliest part, of a univalve or bivalve shell.
  • (n.) The central part around which additional growths are added, as of an operculum.
  • (n.) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks.

Example Sentences:

  • (1) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
  • (2) The present results provide no evidence for a clear morphological substrate for electrotonic transmission in the somatic efferent portion of the primate oculomotor nucleus.
  • (3) In the caudal spinal trigeminal nucleus (Vc), the collaterals of one half of the periodontium afferent fibers terminated mainly in lamina V at the rostral and middle levels of Vc.
  • (4) It is concluded that in the mouse model the ability of buspirone to reduce the aversive response to a brightly illuminated area may reflect an anxiolytic action, that the dorsal raphe nucleus may be an important locus of action, and that the effects of buspirone may reflect an interaction at 5-hydroxytryptamine receptors.
  • (5) hypoglossal nucleus), whereas in other areas the angiotensinogen gene was expressed only in a certain population of glial cells.
  • (6) Local application of 8-OH-DPAT (0-5 micrograms) into the median raphe nucleus, facilitated male rat sexual behavior, as evidenced by a decrease in number of intromissions preceding ejaculation and in time to ejaculation.
  • (7) In addition, lightly immunostained cells were distinguished in the caudal portion of the hypothalamic arcuate nucleus, area of tuber cinereum, retrochiasmatic area, and rostral portion of the paraventricular thalamic nucleus after colchicine treatment.
  • (8) Arising of the nucleus from a polyheteronomous nucleoid of proeukaryotes.
  • (9) It is possible that the IgE that linked abnormally with the propofol had specific binding sites for the phenyl nucleus and the isopropyl groups, which are present in propofol and many other drugs.
  • (10) We conclude that neuronal activities in the region of the retrofacial nucleus are important both in the integration of stimuli from the central chemoreceptors and in defining the discharge patterns of respiratory neurons.
  • (11) A 68 year-old man with a history of right thalamic hemorrhage demonstrated radiologically in the pulvinar and posterior portion of the dorsomedian nucleus developed a clinical picture of severe physical sequelae associated with major affective, behavioral and psychic disorders.
  • (12) While the heaviest anterogradely labeled ascending projections were observed to the contralateral ventral posterolateral nucleus of the thalamus, pars oralis (VPLo), efferent projections were also observed to the contralateral ventrolateral thalamic nucleus (VLc) and central lateral (CL) nucleus of the thalamic intralaminar complex, magnocellular (and to a lesser extent parvicellular) red nucleus, nucleus of Darkschewitsch, zona incerta, nucleus of the posterior commissure, lateral intermediate layer and deep layer of the superior colliculus, dorsolateral periaqueductal gray, contralateral nucleus reticularis tegmenti pontis and basilar pontine nuclei (especially dorsal and peduncular), and dorsal (DAO) and medial (MAO) accessory olivary nuclei, ipsilateral lateral (external) cuneate nucleus (LCN) and lateral reticular nucleus (LRN), and to a lesser extent the caudal medial vestibular nucleus (MVN) and caudal nucleus prepositus hypoglossi (NPH), and dorsal medullary raphe.
  • (13) In contrast to this, adrenalectomy decreased ANP levels markedly in the organum vasculosum laminae terminalis and preoptic periventricular nucleus, which are reportedly involved in the central regulation of salt and water homeostasis.
  • (14) The shape of the nucleus changes from ovoid to a distinctive, radially splayed lobulated structure.
  • (15) Immunocytochemical analysis also suggested that bFGF immunoreactivity was present in the nucleus as well as the cytoplasm of astrocytes and CA2 neurons.
  • (16) The effect of Y-516 on the hyperactivity induced by dopamine injected bilaterally into the nucleus accumbens was compared with those of clocapramine (CCP), haloperidol (HPD) and chlorpromazine (CPZ).
  • (17) Moderately differentiated tumor revealed a wider range of nucleus size, less clustering (coefficient--3.59) and more hyperchromatic (70.1%) and "bare" (49.4%) nuclei and large nucleoli (22.2%).
  • (18) The majority of intensively stained and densely packed cells have been observed in tv nucleus.
  • (19) Following electrical stimulation of the hypothalamic paraventricular nucleus (PVN) area, 21% of the neurons were orthodromically excited, 6% were inhibited and 2.5% were antidromically activated.
  • (20) Proenkephalin A-related immunoreactive neuronal perikarya were detected in the central gray, reticular formation, nucleus raphes, trapezoid body, nucleus parabrachialis lateralis and medialis, nucleus spinalis nervi trigemini, nucleus dorsalis nervi vagi, and in the nucleus tractus solitarii.