The Design And Clinical Use Of A Reflective Brachial Photoplethysmograph

This report concerns the design and clinical use of a reflective brachial photoplethysmograph. A plethysmograph is an instrument to obtain tracings showing volume changes of a part of the body. Originally this related to volume variations due to blood circulation within the body part of interest. The instrument is said to have been invented by Mosso of Turin around 1870 [1], known in Italian as a "pletismografo", and first reported in Scientific American in July 1872. A photoplethysmograph is an optical detector that indicates the volume of blood in or passing through an area of tissue. By placing the photoplethysmograph at or near the site of a human artery the pulse waveform can be detected and measured. The photoplethysmograph can be transmissive or reflective. There are a variety of sites around the body that are commonly used for detecting the pulse waveform including the finger, the ear lobe, and the foot. The device developed in this work is a reflective detector that uses the brachial artery as a photoplethysmographic site. There appear to be no prior indications in academic or patent literature of this site being used with this type of detector and consequently the authors believe this device to be novel and worthy of reporting to the research community

Electrocardiograph and photoplethysmograph superimposition as an investigative tool for circulatory function

This paper set out to examine the usefulness of the electrocardiograph (ECG) and photoplethysmograph (PPG) superimposition as an investigative tool for circulatory function. Further, a system was constructed and an experimental protocol established to examine this proposition. The three main components of circulatory function are pulse rate, arterial compliance and blood pressure. These components are each interrelated, and these relationships are the subject of much research. It was decided, focusing on blood pressure, to examine the superimposition information with regard to systolic, diastolic and mean blood pressure. Data was collected, conclusions were drawn and interesting possibilities for further work emerged

7,11,15,28-Tetra­methyl-1,21,23,25-tetra­kis(2-phenyl­ethyl)resorcin[4]arene ethyl acetate clathrate

The title compound, C68H64O8·C4H8O2, is a new resorcin­[4]arene cavitand synthetic precursor, obtained by alkyl­ation of a previously reported resorcin[4]arene. The additional alkyl bridges significantly rigidify the structure and enforce a ‘bowl’ shape on the mol­ecular cavity. In the crystal structure, the mol­ecule lies on a crystallographic mirror plane, and a single ethyl acetate mol­ecule (also lying on the mirror plane) is present within the compound cavity, illustrating the host capabilities of the mol­ecule

(1R,3S)-Methyl 2-benzyl-6,7-dimeth­oxy-1-phenyl-1,2,3,4-tetra­hydro­isoquinoline-3-carboxyl­ate

In the title compound, C26H27NO4, a precursor to novel chiral catalysts, the N-containing six-membered ring assumes a half-boat conformation. Various C—H⋯π interactions and intermolecular short contacts (C⋯H = 2.81–2.90 Å) link the mol­ecules together in the crystal structure

Guanine a-carboxy nucleoside phosphonate (G-a-CNP) shows a different inhibitory kinetic profile against the DNA polymerases of human immunodeficiency virus (HIV) and herpes viruses

α-Carboxy nucleoside phosphonates (α-CNPs) are modified nucleotides that represent a novel class of nucleotide-competing reverse transcriptase (RT) inhibitors (NcRTIs). They were designed to act directly against HIV-1 RT without the need for prior activation (phosphorylation). In this respect, they differ from the nucleoside or nucleotide RTIs [N(t)RTIs] that require conversion to their triphosphate forms before being inhibitory to HIV-1 RT. The guanine derivative (G-α-CNP) has now been synthesized and investigated for the first time. The (L)-(+)-enantiomer of G-α-CNP directly and competitively inhibits HIV-1 RT by interacting with the substrate active site of the enzyme. The (D)-(−)-enantiomer proved inactive against HIV-1 RT. In contrast, the (+)- and (−)-enantiomers of G-α-CNP inhibited herpes (i.e. HSV-1, HCMV) DNA polymerases in a non- or uncompetitive manner, strongly indicating interaction of the (L)-(+)- and the (D)-(−)-G-α-CNPs at a location different from the polymerase substrate active site of the herpes enzymes. Such entirely different inhibition profile of viral polymerases is unprecedented for a single antiviral drug molecule. Moreover, within the class of α-CNPs, subtle differences in their sensitivity to mutant HIV-1 RT enzymes were observed depending on the nature of the nucleobase in the α-CNP molecules. The unique properties of the α-CNPs make this class of compounds, including G-α-CNP, direct acting inhibitors of multiple viral DNA polymerases

X-Ray Crystallography and Isothermal Titration Calorimetry Studies of the Salmonella Zinc Transporter ZntB

SummaryThe ZntB Zn2+ efflux system is important for maintenance of Zn2+ homeostasis in Enterobacteria. We report crystal structures of ZntB cytoplasmic domains from Salmonella enterica serovar Typhimurium (StZntB) in dimeric and physiologically relevant homopentameric forms at 2.3 Å and 3.1 Å resolutions, respectively. The funnel-like structure is similar to that of the homologous Thermotoga maritima CorA Mg2+ channel and a Vibrio parahaemolyticus ZntB (VpZntB) soluble domain structure. However, the central α7 helix forming the inner wall of the StZntB funnel is oriented perpendicular to the membrane instead of the marked angle seen in CorA or VpZntB. Consequently, the StZntB funnel pore is cylindrical, not tapered, which may represent an “open” form of the ZntB soluble domain. Our crystal structures and isothermal titration calorimetry data indicate that there are three Zn2+ binding sites in the full-length ZntB, two of which could be involved in Zn2+ transport

Redetermination of chlorido(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)gold(I) dichloride trihydrate at 173 K

The redetermined structure of the title compound, [AuCl(C15H11N3)]Cl2·3H2O, at 173 (2) K is reported. The structure displays O—H⋯Cl and O—H⋯O hydrogen bonding. The distance of one of the chloride ions from the gold(I) atom [5.047 (1) Å] differs from that determined previously