Animal lectins as cell adhesion molecules

Protein-carbohydrate interaction is exploited in cell adhesion mechanisms besides the recognition of peptide motifs. The sugar code thus significantly contributes to the intriguing specificity of cellular selection of binding partners. Focusing on two classes of lectins (selectins and galectins), it is evident that their functionality for mediation of adhesive contacts is becoming increasingly appreciated, as is the integration of this type of interaction with other recognition modes to yield the noted specificity. The initial contact formation between leukocytes and activated endothelium makes use of selectins to guide lymphocyte trafficking. In addition to the three selectins which bind a distinct array of ligands, galectin-1 and galectin-3 and possibly other members of this family are involved in cell-cell or cell-matrix interactions. This review summarizes structural and functional aspects of these two classes of endogenous lectins relevant for cell adhesion

Self-Policing: Dissemination and Adoption of Police Eyewitness Policies in Virginia

Professional policing organizations emphasize the importance of the adoption of sound police policies and procedures, but traditionally doing so has been left to individual agencies. State and local government typically does not closely regulate police, and neither federal constitutional rulings nor state law typically sets out in any detail the practices that police should follow. Thus, law enforcement agencies must themselves draft and disseminate policy. This paper presents the results of studies used to assess the adoption of eyewitness identification policies by law enforcement agencies in Virginia. Policymakers were focused on this problem because Virginia experienced a series of DNA exonerations in cases involving eyewitness misidentifications. In 2005, lawmakers enacted a law that required agencies to have some written policy in place. However, there was little guidance on what that policy should be. To remedy this problem, the state law enforcement policy agency, the Virginia Department of Criminal Justice Services (DCJS) promulgated, in 2011, a detailed model policy on eyewitness procedure. Nevertheless, as reported in a 2013 study, those model practices were only haltingly adopted. In particular, many agencies did not use blind or blinded lineups, in which the administrator does not know which photo is that of a suspect or cannot view which photo the eyewitness is examining. In Fall 2018, all of the over-three hundred law enforcement agencies in Virginia had their policies on this subject requested, using the state freedom of information law. The results show that there has now been widespread adoption of the DCJS model policy. Improved eyewitness identification practices have been adopted by the vast majority of agencies, including large and small agencies. This Article concludes by asking what contributed to the extensive dissemination of a model police policy, and what its implications are for improving police policy and practice without the use of regulation

Preparation and Crystal Structure of Diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II)

The crystal structure of the coordination polymer diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II) was determined by X-ray diffraction. The copper atoms are connected to chains over the bridging 5,5'-bistetrazolato ligand. The energetic properties of the compound were investigated, such as thermal behavior and sensitivities (shock, friction, electrical spark)

1-Nitrimino-5-azidotetrazole: Extending Energetic Tetrazole Chemistry

Azide and nitrimino functions are among the most energetic substituents that can be introduced to the skeleton to enhance the energetic properties of a compound. In this study, we report the successful synthesis of a compound that combines both, azide and nitrimino substituents directly attached to one tetrazole scaffold. 1-Nitrimino-5-azidotetrazole is prepared by nitration of 1-amino-5-azidotetrazole. Subsequent salination with ammonia and guanidinium carbonate yields two highly energetic derivatives. All energetic compounds, as well as the intermediate steps of an alternatively developed synthesis strategy, were analysed and characterized in detail. In addition to multinuclear NMR and IR spectroscopy, crystal structures of all key compounds were measured. The sensitivities (friction, impact, electrostatic discharge and thermal) were determined accordingly. In addition, the detonation parameters of all energetic substances were calculated with the EXPLO5 code, which was fed with the enthalpy of formation (atomization method based on CBS-4M) and the crystallographic densities