Nuclear sap

When we examine a cell in its resting stage we find the nucleus more or less spherical in shape, surrounded by a nuclear membrane and containing a nuclear network, nuclear sap and one or more nucleoli. The nuclear network consists of a colorless network of linin adhering to which are numerous minute granules called chromatin which take the stain of a basic dye. Surrounding the nucleus is the cytoplasm. 

The nucleolus is a web of threads with no surrounding membrane, and is rich in RNA. The nuclear sap contains chromatin threads which, at mitosis, become more densely organized and are seen as chromosomes (DNA+proteins). The total length of DNA in a nucleus is about 1 m, made up of about 3X10 nucleotides each with a molecular weight of about 350. F. Sanger has compared the amount of information stored in this quantity of DNA to that available in a large library. 

Skaer. R. J., and Whytock, S. (1977). Chromatin-like artifacts from nuclear sap.7. CellSd. 26,301-310. 

The 400 A particles may also be observed in the nuclear sap and in the region of the nuclear pores. They occupy the same place in the nucleus as the rapidly labeled nuclear RNA (Felling, 1964) detected radioautographically. The particles described are sensitive both to RNase and to proteases, which is an indication of their ribonucleoprotein nature. 

It is not clear whether this degradation is a result of the action of the proteins of the particles themselves or whether some free enzymes of the nuclear sap are involved. It should be pointed out that crude 308 particles have some RNase activity. Lukanidin (1969) (see also Georgiev, 1967) has found that after urea treatment the latent RNase is activated and that this leads to the degradation of the RNA of the particles. 

This process has not yet been studied at all, and the mechanism of the movement of macromolecules from chromosomes to the cytoplasm is quite unclear. The only useful information is based on electron microscopic observations. One can observe particles presumably containing D-RNA, such as Beerman granules or perichromatin granules, interchromatin granules, and helices in different parts of the nucleus. They may be bound to chromatin threads or lie freely in the nuclear sap or even be in contact with the nuclear membrane. These pictures may reflect the movement of the particles from chromatin to the nuclear membrane (Beerman and Bahr, 1954 Stevens and Swift, 1966, Monneron and Bernhard, 1969). As all these types of particles are of ribonucleoprotein nature and have many properties similar to those of isolated nuclear D-RNP, it is possible to suggest that D-RNA moves to the nuclear membrane in a complex with informofers. 

Dettlaff et al. (1964) first reported that nuclear sap taken from the GV of toad c-ocytes in the process of dissolution could induce maturation when injected back into other unstimulated oocytes. Recently, these kinds of experiments have been repeated and considerably extended using Rana pipiens (Smith and Ecker, 1971 Masui and Markert, 1971). In our original experiments, animal hemisphere cytoplasm, taken from oocytes in the process of GV dissolution, induced maturation in more than 90% of the recipient oocytes which had not been exposed to exogenous progesterone, while animal hemisphere cytoplasm from first meiotic metaphase donors induced 100% of the recipient oocytes to mature (Smith and Ecker, 1971). However, neither the time of appearance of this intracellular inducer nor the role of the GV in its appearance was specified. Subsequently, Masui and Markert (1971) reported that, when the volume of injected cytoplasm was kept constant, the frequency of maturation in recipient oocytes increased with time after donor oocytes were exposed to progesterone. Gytoplasmic inducer activity was first detected... 

The cellular nudeus, during interphase, consists prindpally of a nuclear sap or caryolymph, a nudeolus and certain chromatin filaments or chro-monemata which condense into chromosomes during mitosis. 

That the cytoplasmic nucleic acid is present in the mitochondria, the micro-eomes, and the non-sedimentable cell-sap is also known.117 The nuclear ribonucleic acid has been reported to be associated with the nucleolus and the chromosomes.118 It is known, moreover, that the ribonucleic acids of the different parts of the cell are biochemically distinct, since they become labeled with P32 at different rates.119 In liver cells, the nuclear ribonucleic acid is also chemically distinct from the cytoplasmic material, since the two differ in composition.120 It is clear, therefore, that ribonucleic acids prepared from whole cells are likely to be mixtures of various molecular species. 

Historically, a classic example of an evaporation process is the production of table salt. Maple syrup has traditionally been produced by evaporation of sap. Concentration of black liquor from pulp and paper processing constitutes a large-volume present application. Evaporators are also employed in such disparate uses as desalination of seawater, nuclear fuel reprocessing, radioactive waste treatment,preparation of boiler feed waters, and production of sodium hydroxide. They are used to concentrate stillage waste in fermentation processes, waste brines, inorganic salts in fertilizer production, and rinse liquids used in metal finishing, as well as in the production of sugar, vitamin C, caustic soda, dyes, and juice concentrates, and for solvent recovery in pharmaceutical processes. 

Good practice in the management of safety at nuclear facilities is addressed in a number of International Atomic Energy Agency (IAEA) publications. Examples include GS-R-3, the Management Systems of Facilities and Activities (Reference 9.1), draft Safety Guide 349, the Application of the Management System for Nuclear Installations (Reference 9.2), and the HSE S ety Assessment Principles (SAPs) (MSI to MS4 of Reference 9.3). 

The management of radiation protection in the UK is governed by the Ionising Radiation Regulations 1999 (Reference 12.2) and also the principles and criteria presented in the Nil Safety Assessment Principles (SAPs) for Nuclear Facilities (Reference 12.3). 

The water potential in SAP has been studied using relaxation time measurement by nuclear magnetic resonance spectroscopy (NMR), and for measurement on freezing and melting temperature, differential scanning calorimetry (DSC) was used [8, 9]. It has been found that the majority of water held by SAP (98-99%) is free water. Semibound water and bound water are known to be 1 to 1.5 kg/kg dry SAP. 

Since the SANS scattering intensity is generally described as depending, in part, on differences in the interaction energies sap of the hydrogenated and deuterated species, the random partial deuterium substitution leads to an additional interaction randomness that cannot presently be treated with the theory developed here. (The random partial deuteration presumably likewise affects the nuclear reaction analysis data.)... 

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