What's the difference between chemical and mechanical?

Chemical


Definition:

  • (a.) Pertaining to chemistry; characterized or produced by the forces and operations of chemistry; employed in the processes of chemistry; as, chemical changes; chemical combinations.
  • (n.) A substance used for producing a chemical effect; a reagent.

Example Sentences:

  • (1) Brain and ganglia of embryonic Periplaneta americana were grown for 2 to 3 weeks in a chemically defined medium.
  • (2) Stimulation of human leukocytes with various chemical mediators such as TPA, f-Met-Leu-Phe, LTB4, etc.
  • (3) This suggested that the chemical effects produced by shock waves were either absent or attenuated in the cells, or were inherently less toxic than those of ionizing irradiation.
  • (4) At 36 h postsurgery, RBCs were examined by 23Na-NMR by using dysprosium tripolyphosphate as a chemical shift reagent.
  • (5) The absorption of ingested Pb is modified by its chemical and physical form, by interaction with dietary minerals and lipids and by the nutritional status of the individual.
  • (6) Changes in cardiac adenosine triphosphate (ATP), phosphocreatine (PCr) and inorganic phosphate (Pi) were followed and intracellular pH (pHi) was estimated from the chemical shift of Pi.
  • (7) Maximal aberration yields were observed for 2,4-diaminotoluene, 2,6-diaminotoluene and cytosine beta-D-arabinofuranoside from 17 to 21 h, eugenol from 15 to 21 h, cadmium sulfate from 15 to 24 h and 2-aminobiphenyl, from 17 to 24 h. For adriamycin at 1 microM, the % aberrant cells remained elevated throughout the period from 9 to 29 h, while small increases at 0.1 microM ADR were found only at 13 and at 25 h. For most chemicals the maximal aberration yield occurred at a different time for each concentration tested.
  • (8) 2.39pm BST The European Union called for a "thorough and immediate" investigation of the alleged chemical attack.
  • (9) "With hyperspectral imaging, you can tell the chemical content of a cake just by taking a photo of it.
  • (10) The deactivated columns had the residual silanols on the silica gel chemically inactivated to reduce the interaction with basic groups or analytes.
  • (11) A sperm whale myoglobin gene containing multiple unique restriction sites has been constructed in pUC 18 by sequential assembly of chemically synthesized oligonucleotide fragments.
  • (12) On the basis of obtained data on the uniformity of chemical compounds of the secretion of glands belonging to different groups their common origin has been suggested.
  • (13) In spite of important differences in size, chemical composition, polymer density, and configuration, biological macromolecules indeed manifest some of the essential physical-chemical properties of gels.
  • (14) In contrast sham-hemodialysis in group CA and group PS, respectively, did not result in significant increases in amino acid efflux from the leg implying that the protein catabolic effect of blood membrane contact depends on the chemical properties of dialysis membranes.
  • (15) We investigated this suppression quantitatively, using a chemical assay for cell-bound and dissolved capsular polysaccharide.
  • (16) We previously established that the binding constant (Ka) of this receptor site for the chemically synthesized model AGE, 2-(2-furoyl)-4(5)-(2-furanyl)-1H- imidazole-butyric acid (FFI-BA), on cells of the mouse macrophagelike cell line RAW 264.7 is identical to that for AGE proteins.
  • (17) They included lectins such as wheat germ agglutinin (WGA), concanavalin A and phytohemagglutinin, and a chemical cross-linker, glutaraldehyde, in addition to anti-IL-2R monoclonal antibodies, HIEI and H-47.
  • (18) The reduction of such potentials can be explained in terms of collision between the antidromic volleys and those elicited orthodromically by chemical and thermic stimulation.
  • (19) In certain cases, the effects of these substances are enhanced, in others, they are inhibited by compounds that were isolated from natural sources or prepared by chemical synthesis.
  • (20) The use of gaseous insecticides in the chemical control of T. infestans is discussed.

Mechanical


Definition:

  • (a.) Pertaining to, governed by, or in accordance with, mechanics, or the laws of motion; pertaining to the quantitative relations of force and matter, as distinguished from mental, vital, chemical, etc.; as, mechanical principles; a mechanical theory; mechanical deposits.
  • (a.) Of or pertaining to a machine or to machinery or tools; made or formed by a machine or with tools; as, mechanical precision; mechanical products.
  • (a.) Done as if by a machine; uninfluenced by will or emotion; proceeding automatically, or by habit, without special intention or reflection; as, mechanical singing; mechanical verses; mechanical service.
  • (a.) Made and operated by interaction of forces without a directing intelligence; as, a mechanical universe.
  • (a.) Obtained by trial, by measurements, etc.; approximate; empirical. See the 2d Note under Geometric.
  • (n.) A mechanic.

Example Sentences:

  • (1) Such a signal must be due to a small ferromagnetic crystal formed when the nerve is subjected to pressure, such as that due to mechanical injury.
  • (2) These data suggest that the hybrid is formed by the same mechanism in the absence and presence of the urea step.
  • (3) Some common eye movement deficits, and concepts such as 'the neural integrator' and the 'velocity storage mechanism', for which anatomical substrates are still sought, are introduced.
  • (4) We have investigated the effect of methimazole (MMI) on cell-mediated immunity and ascertained the mechanisms of immunosuppression produced by the drug.
  • (5) One hour after direct mechanical cardiomassage (DMCM) a moderately pronounced edema of the intercellular spaces in the basal compartment of the seminiferous epithelium, normal content of lactate and succinate dehydrogenases, and a certain decrease in the activity of glucose-6-phosphate dehydrogenases and NAD- and NADP-diaphorases were noted.
  • (6) It is concluded that amlodipine reduces myocardial ischemic injury by mechanism(s) that may involve a reduction in myocardial oxygen demand as well as by positively influencing transmembrane Ca2+ fluxes during ischemia and reperfusion.
  • (7) Models able to describe the events of cellular growth and division and the dynamics of cell populations are useful for the understanding of functional control mechanisms and for the theoretical support for automated analysis of flow cytometric data and of cell volume distributions.
  • (8) The following is a brief review of the history, mechanism of action, and potential adverse effects of neuromuscular blockers.
  • (9) However, the mechanism of the inhibitory action is still somewhat uncertain.
  • (10) It also provides mechanical support for the collateral ligaments during valgus or varus stress of the knee.
  • (11) We studied the hemodynamic changes caused by bronchoscopy under LA in mechanically ventilated patients and the effect of LA on the endoscopic decline in arterial pO2.
  • (12) Together these observations suggest that cytotactin is an endogenous cell surface modulatory protein and provide a possible mechanism whereby cytotactin may contribute to pattern formation during development, regeneration, tumorigenesis, and wound healing.
  • (13) Dilutional studies comparing the mechanism of inhibition of monoamine oxidase produced by Gerovital H3 and by ipronizid demonstrated that Gerovital H3 was a reversible inhibitor of monoamine oxidase.
  • (14) To investigate the mechanism of enhanced responsiveness of cholesterol-enriched human platelets, we compared stimulation by surface-membrane-receptor (thrombin) and post-receptor (AlF4-) G-protein-directed pathways.
  • (15) Based on our results, we propose the following hypotheses for the neurochemical mechanisms of motion sickness: (1) the histaminergic neuron system is involved in the signs and symptoms of motion sickness, including vomiting; (2) the acetylcholinergic neuron system is involved in the processes of habituation to motion sickness, including neural store mechanisms; and (3) the catecholaminergic neuron system in the brain stem is not related to the development of motion sickness.
  • (16) Thus, mechanical restitution of the ventricle is a dynamic process that can be assessed using an elastance-based approach in the in situ heart.
  • (17) The mechanism by which pertussis toxin (PT) breaks the unresponsiveness of delayed-type hypersensitivity (DTH) to sheep red blood cells (SRBC) was examined in B10 mice.
  • (18) 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.
  • (19) The macrophage-derived product, interleukin 1 (IL 1) is thought to play an important regulatory role in the proliferation of T lymphocytes; however, its mechanism of action is unknown.
  • (20) Adding a layer of private pensions, it was thought, does not involve Government mechanisms and keeps the money in the private sector.