Direct enhancement

The magnitude of the indirect nOe effect depends on the geometry of the three-spin system. It is maximum with a linear geometry of the spin system (0 = 180°). When 0 decreases, the distance also decreases, and the direct enhancement at C becomes more and more significant. At 0 = 78°, the direct and indirect nOe effects become equal. With smaller values of 0, the direct contribution rapidly starts to dominate the nOe at C, and a strong positive enhancement results. This means that indirect nOe effects are to be expected mainly when the spins are close to having a linear geometry. 

Broxmeyer HE, Kohli L, Kim CH, et al. Stromal cell-derived factor-l/CXCL12 directly enhances survival/antiapoptosis of myeloid progenitor cells through CXCR4 and G(alpha)i proteins and enhances engraftment of competitive, repopulating stem cells. J Leukoc Biol 2003 73(5) 630-638. 

The GABA-gated chloride ion channel is modulated by several classes of drugs that bind to allosteric sites on the receptor complex the benzodiazepines, barbiturates and related intravenous general anesthetics such as etomidate and propofol, as well as anesthetic steroids and endogenous neurosteroids. It appears that some types of GABAa receptor are directly enhanced by ethanol and volatile general anesthetics (Fig. 16-2) [7,8,20]. 

In addition to direct enhancement of channel activity, PTKs can indirectly increase GABA-evoked inhibitory current by recruiting intracellular GABAaR to the surface of postsynaptic membrane. Insulin has been shown to increase surface expression GABAaR in transfected human embryonic kidney cells. In central neurons insulin rapidly increases the expression of functional postsynaptic GABAaR in a tyrosine kinase-dependent manner, resulting in an increase in the amplitude of the miniature inhibitory postsynaptic currents. 

Ruby, C., Funatake, C., and Kerkvliet, N. I., 2,3,7,8-Tetrachlorodibenzo-p-dioxin directly enhances maturation and apoptosis of dendritic cells in vitro, J. Immunotoxicol., 1, 159,2004. 

In addition to containing protein-protein interaction motifs, E3-substrate specificity may be affected by post-translational modifications. In particular, phosphorylation can alter E3-substrate interactions. One example is p53 where certain phosphorylations inhibit its direct binding to Mdm2, while others indirectly enhance their association by promoting nuclear localization of p53 [104-106]. Phosphorylation also directly enhances substrate interactions, as exemplified by the Cbls, which include phospho-tyrosine binding domains (see below) [107]. 

Besides their influence on APCs, evidence accumulates that mast cells are also able to directly enhance the activity of T cells. This was reported... 

S. L. Friedman and M. J. P. Arthur, Activation of cultured rat hepatic lipocytes by Kupffer cell conditioned medium. Direct enhancement of matrix synthesis and stimulation of cell proliferation via induction of platelet-derived growth factor receptors, J. Clin. Invest. 84 1780-1785 (1989). 

Hobson J, Gilks B, Wright J, et al. 1988. Direct enhancement by cigarette smoke of asbestos fiber penetration and asbestos-induced epithelial proliferation in rat tracheal explants. J Natl Cancer Inst 80 518-521. 

Colossal magnetoresistance studies of ceramics have demonstrated no significant influence of ceramic density on the magnetoresistance at H = 1.5T. However, ceramics obtained by the solid state synthesis method and containing inclusions of lanthanum-doped manganese oxide displayed substantially higher magnetoresistance values. This effect was later used for directed enhancement of low field... 

The MeOH extract from the rhizomes of Iris tectorum (Iridaceae) gave a spiroiridal triterpenoid, 28-deacetylbelamcandal (7). This substance stimulated differentiation of human promyelocytic leukaemia (HL-60) cells. It inhibited the specific [ HJPDBu binding to PKC, similarly to TPA in a dose-dependent fashion. In addition, 28-deacetylbelamcandal directly enhanced PKC activity [30],... 

It may be that ultrasonic enhancement of mass transport sweeps the intermediate radicals that have escaped the electrode back to the electrode surface where they are further oxidized, although this would depend upon radical lifetimes. Direct enhancement of the second electron transfer to give the cation while species remain in first contact with the electrode would be complicated by the decarboxylation step after the first electron transfer, and also by an observation of weak electrochemiluminescence (ECL) from the electrolysis cell in phenylacetate electrooxidation (see Section 5.2) [215]. This is enhanced by ultrasound, as are a number of other ECL systems. This suggests that at least a proportion of the reaction pathway involves benzyl radicals which escape the electrode, although the sonoelectrochemilumines-cence reaction conditions of low carboxylate concentration, low current density, and presence of electrolyte salt are different to those for the preparative electrolyses. 

Some packages directly enhance consumption or further preparation of the product. Probably, the most famous example is the TV dinner, which allowed meals to go from the freezer to the oven to the table. Later, the metal tray was replaced by a plastic one, permitting even faster food preparation in the microwave oven. Many packages make it easy for us to use the products they contain (e.g., squeezable bottles, reclosable liquid board containers, plastic bottles with handles, and pop-up dispenser tops). 

Arterial flow into the corpora is enhanced by acetylcholine-mediated vasodilation. Acetylcholine does not directly enhance arterial flow to the corpora or increase sinusoidal filling of the corporal tissue. Rather, acetylcholine is a co-neurotransmitter, which works along with other nonpeptidinergic intracellular neurotransmitters— including cyclic guanosine monophosphate (cGMP), cyclic adenosine monophosphate (cAMP), or vasoactive intestinal polypeptide— to produce vasodilation. 

One may conclude that laser action is 1.8 time less efficient with respect to photo action, monitored for the same [AIBN]0. (See table 1). It may be the result of the fact that in the case of laser stimulation the concentration of formed excited molecules is 107 S times more than in the case of photo excitation.This results in increase of quenching rate (spontanous and concentration). Apart in the case of laser stimulation one cannot exclude sharp enhance of Si—>Ti inter combination conversion, resulting in direct enhance of populations number on Ti level [31]. The nondependence of kQ in ChB and VA on solvent nature once more underlines the AIBN importance as quencher. 

Another strategy is to directly enhance dopamine function as well as the activities of B-cell lymphoma protein 2 (Bcl-2), which is another important component that may play a role, eventually, in the resolution of depression. Examples of various non-selective enhancers of dopamine that also stimulate Bcl-2 are pergolide, ropinirole, and selegiline, while pramipexole may directly enhance Bcl-2. The antidepressant effect exhibited by enhanced dopaminergic transmission is thought to be at least partially related to increased dopaminergic transmission in limbic structures (e.g. the nucleus accumbens). - ... 

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