Raman spectroscopy for forensic body fluid analysis has received some attention due to the nondestructive nature and potential application for identification at the crime scene; however, its usage has been limited by low detection sensitivity. Surface enhanced Raman scattering (SERS) was evaluated for blood identification for forensic applications. Specifically, a SERS-active substrate was fabricated, composed of nickel nanotips coated with Ag nanoparticles. Compared with a conventional substrate, the SERS substrate enhanced Raman scattering by more than two orders of magnitude and allowed blood to be identified to a dilution of 1:100,000. Blood was also successfully detected by swabbing the SERS substrate directly on mock evidence. Most importantly, Raman spectra obtained by swabbing the SERS substrate on blood stains were free of luminescence even when blood was deposited on luminescent fabrics. The nondestructive character, simplicity of sample preparation, and high sensitivity make SERS a prime candidate for field and laboratory-based blood identification.

Loss of function mutations in the receptor tyrosine kinase TrkB pathway resulted in hyperphagia and morbid obesity in human and rodents. Conversely, peripheral or central stimulation of TrkB by its natural ligands BDNF or NT4 reduced body weight and food intake in mice, supporting the idea that TrkB is a key anorexigenic signal downstream of the melanocortin-4 receptor (Mc4r) system. Here we show that in non-human primates TrkB agonists were anorexigenic when applied centrally, but surprisingly orexigenic, leading to gain in appetite, body weight, fat deposits and serum leptin levels, when given peripherally. The orexigenic and pro-obesity effects of peripherally administered TrkB agonists appear to be dose dependent, not associated with fluid retention nor with evidence of receptor down regulation. Our findings revealed that TrkB signaling exerts dual control on energy homeostasis in the primates that could be targeted for the treatment of either wasting disorders or obesity.

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Canadian science has embraced mass spectrometry with much purpose and enthusiasm for more than 50 years. Arthur Dempster in the early 1900s was the first Canadian to do so (although his work was conducted in the U.S.), and this early tradition was continued by people like Harry Duckworth, Larkin Kerwin, Harry Thode, Charles McDowell, Fred Lossing, and Harold Schiff. This is the first of four issues planned for Mass Spectrometry Reviews that will highlight more recent contributions to the development and application of mass spectrometry ''made in Canada,'' within the larger context of advances originating with our international colleagues. Future issues will address instrumental and methodological developments as well as environmental, biological and medical applications. This first issue will focus on the use of mass spectrometry for the elucidation of fundamental aspects of ions including their structures, stabilities, and chemical reactivities. Emphasis is given to the mechanisms of rovibrational and electronic excitation and to fundamental aspects of energy transfer initiated by collisional activation. Collision-induced dissociation is applied by Alex Harrision in the fragmentation of protonated and multiply-protonated peptides produced by soft ionization. The achievements of this technique in peptide sequencing are well known, but challenges remain in our understanding of the structures and formation mechanisms of b-ions. Alan Hopkinson has chosen to focus on radical cations of amino acids and peptides produced by the collision-induced dissociation of ternary metal complexes, and has explored the driving forces for the fragmentation of these ions using primarily DFT calculations. Diethard Bohme highlights achievements made in the gas-phase ion chemistry of the famous buckminsterfullerene molecule and how these have provided new insights into, and opened new doors of discovery of, fundamental aspects of ion chemistry, especially chemistry involving multiply charged ions. John Holmes draws on his vast experience to provide the reader with an appreciation of empirical relationships between the thermodynamics and physical properties of ions, as well as valuable guidance in the evaluation and estimation of thermochemical properties of ions and molecules.While it is true that recent impressive advances have moved mass spectrometry from the highly specialized applications that interested the pioneers to its status as a ubiquitous enabling technology in modern science, our knowledge of the structures and reactions of gaseous ions still leaves much to be desired. Hopefully this volume will serve as a useful snapshot of the current state of the art, albeit with a distinct Canadian flavor.