Heart cockle shells transmit sunlight to photosymbiotic algae using bundled fiber optic cables and condensing lenses.

Many animals convergently evolved photosynthetic symbioses. In bivalves, giant clams (Cardiidae: Tridacninae) gape open to irradiate their symbionts, but heart cockles (Cardiidae: Fraginae) stay closed because sunlight passes through transparent windows in their shells. Here, we show that heart cockles (Corculum cardissa and spp.

The broad antibacterial activity of a small synthetic receptor for cellular phosphatidylglycerol lipids.

A small receptor molecule composed of a porphyrin core with tetrakis-ammonium glycine pickets (liptin 3e) appears to target anionic phosphatidylglycerol (PG) lipid head groups through multifunctional binding-pocket complementarity. Although a major component of bacterial cell membranes, PG is not widely found in animal cells, making PG potentially selective for bacterial targeting. Growth of microbial isolates was monitored in liquid cultures treated with liptin 3e by dilution plate counts and turbidity.

Comparison of temperature and doping dependence of elastoresistivity near a putative nematic quantum critical point.

Strong electronic nematic fluctuations have been discovered near optimal doping for several families of Fe-based superconductors, motivating the search for a possible link between these fluctuations, nematic quantum criticality, and high temperature superconductivity. Here we probe a key prediction of quantum criticality, namely power-law dependence of the associated nematic susceptibility as a function of composition and temperature approaching the compositionally tuned putative quantum critical point. To probe the 'bare' quantum critical point requires suppression of the superconducting state, which we achieve by using large magnetic fields, up to 45 T, while performing elastoresistivity measurements to follow the nematic susceptibility.

Sources of error in clinical measurement of the amplitude of accommodation.

Measurement of the amplitude of accommodation is established as a procedure in a routine optometric eye examination. However, clinical methods of measurement of this basic optical function have several sources of error. They are numerous and diverse, and include depth of focus, reaction time, instrument design, specification of the measurement end-point, specification of the reference point of measurement, measurement conditions, consideration of refractive error, and psychological factors.

A Review of Depth of Focus in Measurement of the Amplitude of Accommodation.

The aim of this review is to investigate the role of depth of focus (DoF) as a potential confounding variable in the measurement of the amplitude of accommodation (AoA). The role of DoF in human vision is briefly summarised, and it is noted that the prevalent method of measuring AoA is the push-up method. Factors influencing the effect of DoF on the push-up and other methods of measuring AoA are reviewed in detail.

Ultrasonic frequency analysis for estimating pH in albumin-rich biofluids.

Ultrasound is known as a non-invasive imaging modality capable of propagating through highly scattering media such as tissue, blood, and other biological fluids, yet currently provides little chemical information. We have developed a straightforward and rapid methodology for estimating pH in albumin-rich biofluids based on analysis of ultrasonic frequencies. Albumin is the most abundant protein in serum and undergoes conformational changes with pH.

Developing a targeting system for bacterial membranes: measuring receptor-phosphatidylglycerol interactions with (1)H NMR, ITC and fluorescence correlation spectroscopy.

An ammonium picket porphyrin that targets bacterial membranes has been prepared and shown to bind to phosphatidylglycerol (PG), a bacterial lipid, when the lipid was in solution, contained within synthetic membrane vesicles, or when in Gram-negative and Gram-positive bacterial membranes. The multifunctional receptor was designed to interact with both the phosphate anion portion and neutral glycerol portion of the lipid headgroup. The receptor's affinity and selectivity for binding to surfactant vesicles or lipid vesicles that contain PG within their membranes was directly measured using fluorescence correlation spectroscopy (FCS).

(11)C-MK-8278 PET as a tool for pharmacodynamic brain occupancy of histamine 3 receptor inverse agonists.

Unlabelled: The histamine 3 (H3) receptor is a presynaptic autoreceptor in the central nervous system that regulates the synthesis and release of histamine and modulates the release of other major neurotransmitters. H3 receptor inverse agonists (IAs) may be efficacious in the treatment of various central nervous system disorders, including excessive daytime sleepiness, attention deficit hyperactivity disorder, Alzheimer disease, ethanol addiction, and obesity.

Methods: Using PET and a novel high-affinity and selective radioligand (11)C-MK-8278, we studied the tracer biodistribution, quantification, and brain H3 receptor occupancy (RO) of MK-0249 and MK-3134, 2 potential IA drugs targeting cerebral H3 receptors, in 6 healthy male subjects (age, 19-40 y).

Synthesis and characterization of picket porphyrin receptors that bind phosphatidylglycerol, an anionic phospholipid found in bacterial membranes.

The lipid binding ability of four urea-picket porphyrins designed to bind to both the phosphate anion portion as well as the glycerol hydroxyl groups of phosphatidylglycerol (PG) has been investigated. Isothermal titration calorimetry (ITC) and (1)H NMR were used to determine the receptor's stoichiometry of binding, association constants, and both the enthalpy and entropy of binding with the PG anion. Spectral evidence shows that the phosphate anion portion of PG is hydrogen bonded to the urea groups of the receptors.

Early prediction of macrosomia based on an analysis of second trimester amniotic fluid by capillary electrophoresis.

Aim: To identify, using capillary electrophoresis and chemometrics, early biomarkers in human amniotic fluid of large-for-gestational-age (LGA) infants.

Materials & Methods: Second trimester amniotic fluid samples, obtained from mothers undergoing age-related amniocentesis, were analyzed by capillary electrophoresis. Electropherogram data were aligned using correlation-optimized warping.

Prediction of gestational diabetes mellitus based on an analysis of amniotic fluid by capillary electrophoresis.

Aim: To detect gestational diabetes mellitus biomarkers in human amniotic fluid collected for age-related genetic testing using capillary electrophoresis and a sophisticated data analysis methodology.

Materials & Methods: Amniotic fluid samples were separated by capillary electrophoresis. Samples were classified using a genetic algorithm with Bayesian benefit function.

Simultaneous determination of alcohol and carbohydrate content in commercial beverages by ultrasound frequency analysis.

Controlling the composition of commercial beverages is critical for quality control. Rapid on-line measurements would allow optimization in real time. We have developed a methodology to monitor the volume fraction of ethanol and the carbohydrate concentrations in liquid mixtures using ultrasound frequency analysis.

Use of near-infrared spectroscopic analysis of second trimester amniotic fluid to assess preterm births.

This pilot study investigated the possibility that metabolomic differences exist in second trimester of women delivering at term (≥37 weeks, n = 216) and preterm (≤35 weeks, n = 11). For this retrospective study, biobanked AF samples underwent near-infrared (NIR) spectral analysis using wavelengths from 700 to 1050 nm. Spectral data was compressed then optimized by multilinear regression to create a calibration model.

Determination of volume fractions in multicomponent mixtures using ultrasound frequency analysis.

Controlling the composition of mixtures is critical for quality control in a wide variety of applications. There is a need for rapid, on-site measurements to optimize processes in real time. Ultrasound easily penetrates opaque samples and containers, yet currently provides minimal chemical information.

Initial structural studies of charged receptors that bind to inorganic phosphate anion and to an anionic phospholipid found in bacterial membranes.

ITC titration studies of a family of bis-ammonium receptors based upon a scaffold of two bis-linked phenol rings show that several of the receptors bind to both dihydrogenphosphate and phosphatidylglycerol anions in a similar binding motif. Thermodynamic properties determined from ITC show that anion binding is entropy driven. Job plots determined from (1)H NMR clearly demonstrate that anion-receptor binding stoichiometry is dependent on the receptor's length of its bis-amine linkage.

Ultrasonic quantification using smart hydrogel sensors.

Analyte quantification in samples with extensive matrix effects can be challenging using conventional analytical techniques. Ultrasound has been shown to easily penetrate samples that can be difficult to measure optically or electrochemically, though it provides little chemical information. Recent ultrasound contrast agents provide highly localized contrast within a sample based on concentration.

Ultrasonic frequency analysis of antibody-linked hydrogel biosensors for rapid point of care testing.

Analyte quantification in highly scattering media such as tissue, blood, and other biological fluids is challenging using conventional spectroscopic methods. Ultrasound easily penetrates these opaque samples, yet currently provides little chemical information. We have developed a general approach for creating hydrogel biosensors based on antibody-linked cellulose polymers.

Fetal exposure to altered amniotic fluid glucose, insulin, and insulin-like growth factor-binding protein 1 occurs before screening for gestational diabetes mellitus.

Objective: We explored the possibility that perturbations in amniotic fluid glucose, insulin, and insulin-like growth factor-binding protein 1(IGFBP1) and/or metabolic acids exist before routine screening for GDM.

Research Design And Methods: We selected consenting mother-infant pairs (n = 408) who met our inclusion criteria (singleton pregnancy, no genetic abnormalities, and no preexisting diabetes) and for whom sufficient amniotic fluid and appropriate medical information were available. We compared birth outcomes and second trimester amniotic fluid glucose, insulin, IGFBP1 concentrations, and amniotic fluid lactic, β-hydroxybutyric, and uric acids of mothers with gestational diabetes mellitus (GDM) (n = 52) with those of mothers with no diagnosis of GDM at >24 weeks (n = 356).

Near-infrared spectroscopy of blood plasma for diagnosis of sporadic Alzheimer's disease.

There are currently no accepted blood-based biomarkers of sporadic Alzheimer's disease (AD). Augmented oxidative stress has been implicated in both neural and peripheral AD tissues. In this study, we determined whether short-wavelength near-infrared (NIR) spectrophotometry of blood plasma differentiates mild sporadic AD from normal aging.

A convenient, one-step synthesis of benzyl (Ar) ureas of the type ArCH(2)NHCONHR from Ar and R(1)OCH(2)NHCONHR via ureidoalkylation.

A method for the one-step C-ureidoalkylation of phenol, anisole, or aniline rings furnishing ArCH(2)NHCONHR (Ar = benzyl) products in moderate to good yields is described. With phenol ring systems, higher yields were attained when the reaction was worked up with an acidic ethanethiol addition to cleave any O-ureidoalkylation products that formed during the reaction.

Identification and quantitation of human amniotic fluid components using capillary zone electrophoresis.

A capillary electrophoresis method was used to measure albumin, immunoglobulin G (IgG), transferrin, and uric acid in 230 amniotic fluid (AF) samples collected at 15.15+/-0.06 weeks gestation.

Two similar dibenzo cyclic ethers with dissimilar conformations.

Two dibenzo cyclic ether compounds, 6,12-dibromodibenzo[d,i]-1,2,3,6,7,8-hexahydro-1,3-dioxecin (systematic name: 8,16-dibromo-2,4-dioxatricyclo[12.4.0.

Measurement of lactate in whole human blood with near-infrared transmission spectroscopy.

We have evaluated the potential of near-infrared spectroscopy (NIRS) as a technique for rapid analysis of lactate in whole blood. To test the NIRS technique, a comparison was made with a standard clinical method using whole blood samples taken from five exercising human subjects at three different stage of exercise. To expand lactate concentration within the physiological range, standard additions method was used to generate 45 unique data points.

Noninvasive metabolomic profiling of embryo culture media using proton nuclear magnetic resonance correlates with reproductive potential of embryos in women undergoing in vitro fertilization.

Objective: To identify biomarkers associated with reproductive outcome using proton nuclear magnetic resonance ((1)H NMR) metabolomic profiling of embryo culture media.

Design: Retrospective study.

Setting: An academic assisted reproductive technology (ART) program; a university research center.

Second trimester amniotic fluid transferrin and uric acid predict infant birth outcomes.

Objective: To establish whether second trimester amniotic fluid protein and/or uric acid concentrations were associated with and predictive of infant birth weight and/or gestational age.

Methods: Second trimester amniotic fluid samples (n = 230) in mothers undergoing age-related amniocentesis for genetic testing were collected and quantified using capillary zone electrophoresis (CZE) for albumin, IgG, transferrin and uric acid. Maternal characteristics (prepregnancy weight and height, parity, ethnicity, smoking status) and infant birth weight, gestational age and gender were obtained from questionnaires and maternal obstetrical chart review.