The Missing Link

Agnew, J.B., Chemical Kinetics-The Missing Link in Reactor Design, Paper B8a, at CHEMECA 85. 

Thus methanation was one of the missing links which needed to be resolved before we could seriously consider coal gasification as a possible solution to our future gas needs. Fortunately, we feel this link is being satisfied as evidenced, for example, by the results of some of the chapters in this volume. 

When dmg regulatory responsibilities are divided, there is no unity of command over dmg regulatory functions. The missing links resulting from fragmentation and delegation... 

The missing link between the constitution of a molecule and its 3D structure in computahonal chemistry is a technique capable of automatically generating 3D models starhng from the connectivity information of a given molecule. Due to its basic role, 3D structure generation is one of the fundamental problems in computahonal chemistry. As a consequence, in recent years a number of automahc 3D model builders and conformer generators have become available. For two comprehensive reviews, see Refs. [3, 4]. 

Flier, J. S. The missing link with obesity Nature 409 292-293, 2001. 

In the Zr-catalyzed cyclic carbometallation discussed above, a tandem process consisting of (i) transmetallation and (ii) P-H abstraction provides the missing link in the catalytic cycle. In a series of recent examples reported by Takahashi [206—208] and Hoveyda [209—214], the missing link has been provided by a process consisting of (i) [5-elimination or deheterometallation (Pattern 10), (ii) transmetallation, and (iii) P-H abstraction (Scheme 1.62). Some of these reactions have been developed into enantioselective C—C bond-forming processes, as discussed below. 

Gullo, F., Ales, E., Rosati, B., Lecchi, M., Masi, A., Guasti, L., Cano-Abad, M.F., Arcangeli, A., Lopez, M.G. and Wanke, E. (2003) ERG K+ channel blockade enhances firing and epinephrine secretion in rat chromaffin cells the missing link to LQT2-related sudden death FASEB Journal, 17, 330-332. 

Weerapura, M Nattel, S Chartier, D Caballero, R. and Herbert, T.E. (2002) A comparison of currents carried by HERG, with and without coexpression of MiRPl, and the native rapid delayed rectifier current. Is MiRPl the missing link The Journal of Physiology, 540 (Pt 1), 15-27. 

M. K. Hellerstein, In vivo measurement of fluxes through metabolic pathways The missing link in functional genomics and pharmaceutical research. Annu. Rev. Nutr. 23, 379 402 (2003). 

Metal Clusters The Missing Link Between Single Atoms... 

A similar pattern has always been discussed for rhodium, with hydri-dotetracarbonylrhodium H-Rh(CO)4 as a real catalyst species. The equilibria between Rh4(CO)i2 and the extremely unstable Rh2(CO)s were measured by high pressure IR and compared to the respective equilibria of cobalt [15,16]. But it was only recently that the missing link in rhodium-catalyzed hydroformylation, the formation of the mononuclear hydridocomplex under high pressure conditions, has been proven. Even the equilibria with the precursor cluster Rh2(CO)8 could be determined quantitatively by special techniques [17]. Recent reviews on active cobalt and rhodium complexes, also ligand-modified, and on methods for the necessary spectroscopic in situ methods are given in [18,19]. 

Schlosser PM, Kedderis GL, Lovem MR, et al. 1998. Identification of benzene oxide The missing link in benzene metabolism. CUT Activities 18 1-8. 

Process Sampling Theory of Sampling the Missing Link in Process Analytical Technologies (PAT)... 

This chapter deals with the necessity of representative sampling in the context of PAT. All PAT sensors need to be calibrated with respect to relevant, reliable reference data (Y data). This presupposes that representative samples are at hand for this characterization - but sampled howl Additionally, X signals (X measurements) need to be qualified as representative of the same volume as was extracted for Y characterization, or at least a sufficiently well-matching volume. How does one demonstrate this in a quantitative manner If the quality of both X and Y data involved is suspect, how can a multivariate calibration be expected to be trustworthy This also includes the issue regarding proper validation of the chemometric multivariate calibration(s) involved, which can only be resolved based on proper understanding of the phenomenon of heterogeneity. The TOS delivers answers to all these issues. The TOS constitutes the missing link in PAT. 

H. Zehender, F. le Goff, N. Lehmann, I. Filipuzzi, L. M. Mayr SpeedScreen the missing link between genomics and lead discovery, J. Biomol. Screen. 2004, 9, 498-505. 

One task awaiting molecular astronomy is to find the missing links that separate 11-atom molecules from PAHs and fullerenes with 20 to 60 atoms, whilst a whole world lies between the most evolved molecules and a simple dust grain which contains, at the lowest estimate, 1 billion atoms. 

Schreiber SL. (2005) Small molecules The missing link in the central dogma. Nat. Chem. Biol. 1 64-66. 

The LSD and PW91-GGA system-averaged holes agree at zero interelec-tronic separation, where both are nearly exact. In Sect. 2.3, we discuss how the near-universality of this on-top hole density provides the missing link between real atoms and molecules and the uniform electron gas. Except very close to the nucleus, the local on-top hole density is also accurately represented by LSD, even in the classically-forbidden tail region of the electron density [18]. 

As mentioned above, LSD yields a reasonable description of the exchange-correlation hole, because it satisfies several exact conditions. However, since the correlation hole satisfies a zero sum rule, the scale of the hole must be set by its value at some value of . The local approximation is most accurate at points near the electron. In fact, while not exact at m = 0, LSD is highly accurate there. Thus the on-top hole provides the missing link between the uniform electron gas and real atoms and molecules [18]. 

It is entirely unexpected that even after heating, in other words only one hour before crysallization, no sign of crystallization appeared. In our next study we would like to find the missing link between the hydrogel and the crystal. 

Figure 2.3 The relation between the compartmentalistic approach and the prebiotic RNA world and the missing link (items 1 and 2).

It seems that there is a missing link between the scenarios of the prebiotic RNA-world and the compartmentalishc approach and the missing link is how to make RNA by a prebiotic sequence or network of internalized reactions. 

In a way, the missing link appears to be the aim of a few distinct research groups, who are inquiring into the possibility of prebiotic metabolic pathways prior to enzymes. There is a rather complex kaleidoscope of authors and views, and it is useful to distinguish between the following main trains of thought. 

Extension of this line of reasoning suggests that there should be a stepwise mechanism based on the SN2 configuration. Thus, just as a concerted E2/E1 pathway finally turns into a stepwise El pathway, the E2H/E2C pathway is predicted, in the limit, to lead to a radical anion intermediate which then undergoes elimination. We have termed this, as yet undiscovered pathway, the E2C-I (I = intermediate) pathway (Pross and Shaik, 1982a). The E2C-I pathway constitutes the missing link in the chain of potential elimination processes based on three intermediate configurations (Fig. 26g). 

Martin W (2005) The missing link between hydrogenosomes and mitochondria. Trends Microbiol 13 457-459... 

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