Janus Group

Despite her reservations, M assigns Bond to investigate the Janus Group. She later admits if you think I don t have the balls to send a man to die, your instincts serve you wrongf (ibid). Bond s view on the opposite sex changes here, as where he would previously regard women as disposable pleasures rather than meaningM pursuits (ibid, 2006), now it is a woman who endows him with a missiom... 

The synthetic route for making the Janus nanoparticles first consists in the emulsion polymerization of styrene in the presence of silica nanoparticles surface-modified by polymerizable groups. Snowman-like hybrid nanostructures are thus obtained with 85% yield in which the... 

Figure 1.29 TEM images of Janus silica nanoparticles (diameter 100 nm) in which the amine grafted area is decorated by gold nanocolloids, the remaining area being functionalized by methyl groups. (Reproduced from ref. 54, with permission.)...

Cytokines all function using a group of transmembrane receptors embedded in the plasma membranes of target cells. The receptors have no tyrosine kinase activity but associate with and activate kinases known as Janus kinases (JAKs). These kinases phosphory-late tyrosine side chains in their receptors, and the phosphorylated receptors activate transcription factors of the STAT (signal transducer-activators of transcription) group.186-195 The specificity of cytokine action results from a combination of receptor recognition and recognition of the various STAT molecules by different JAKs.111 Cytokines have a variety of structures. Many are helix bundles or have (3 sheet structures (Fig. 30-6). 

Considering tridentate sites, 2,6-diaminopyridine and uracil are complementary single site groups (see Sections 9.4.2 and 9.4.3 below). On the other hand barbituric acid (BA) and 2,4,6-triaminopyrimidine (TAP) or -triazine (TAT) are Janus molecules containing two identical recognition sites while 168 is plerotopic by virtue of its two complementary sites (see Section 9.4.4). 

Monomeric transition metal complexes (silver and rhodium) of these Janus bis-carbenes were synthesised by standard procedures, either with reaction of the bis-imidazolium salt with silver(l) oxide or by preparing the free carbene by proton abstraction with LDA and subsequent reaction with [Rh(cod)Cl]2 [379] (see Figure 3.121). If the wingtip group is... 

Complementary dendritic hexamers based on a central scaffold made up of linked pentaerythritol and tri(hydroxymethyl)amino methane units have been found to also exhibit liquid-crystalline properties. This star-shaped scaffold was used to create supermolecules containing two different hemispheres, referred to thereafter as Janus supermolecular Hquid crystals (Fig. 76) [323,324]. One of the hemisphere contains three cyanobiphenyl end-groups, whereas the other lobe consists of three chiral phenyl benzoate mesogenic moieties laterally attached. The type of mesophase observed (N ... 

To further emphasize the double face (Janus face) of the molecule, it has been recently demonstrated that the transfer of a NO group to cysteine sulfhydryls on proteins, known as S-nitrosylation, is a ubiquitous regulatory reaction. It represents a form of redox modulation in diverse tissues. Nitrosylated proteins are relevant in many processes ranging from signal transduction, DNA repair, host defence, and blood pressure control to ion channel regulation and neurotransmission [56]. 

The synthesis of polyelectrolytes with well-defined architectures, however, has imposed many challenges to the polymer chemists. Many polymerization techniques are not tolerable to the ionic functional groups. In most cases, preparation of polyelectrolytes involves the protection and deprotection of the ionic groups in the monomer. For polyelectrolytes with different architectures, various synthetic strategies are required. Recently, we have synthesized various complex architectures containing polyelectrolytes with different nonlinear topologies, such as combshaped [22], hyperbranched [23-25], Janus-type [26], stars [27, 28] and brushes [29-31],... 

Fig. 3. Steric control in cyclic hexamer formation from Janus-type DAD/ADA recognition groups 5 and 6...

Janus recognition groups expressing 1-dimensional motifs may also be combined to form jS-networks (Fig. 16). Modular covalent combination of... 

Fig. 16. Components bearing homotopic Janus-type recognition groups for the generation of tape motifs...

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