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The successful use of a microband electrode printed on a silicon internal reflection element to perform time resolved infrared spectroscopy is described. Decreasing the critical dimension of the microband electrode to several hundred micrometers provides a sub-microsecond time constant in a Kretschmann configured spectroelectrochemical cell. The high brilliance of synchrotron sourced infrared radiation has been combined with a specially designed horizontal attenuated total reflectance (ATR) microscope to focus the infrared beam on the microband electrode. The first use of a sub-microsecond time constant working electrode for ATR surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) is reported. Measurements show that the advantage afforded by the high brilliance of the synchrotron source is at least partially offset by increased noise from the experimental floor. The test system was the potential induced desorption of an adsorbed monolayer of 4-methoxypyridine (MOP) as measured using step-scan interferometry. Based on diffusion considerations alone, the expected time scale of the process was less than 10 microseconds but was experimentally measured to be three orders of magnitude slower. A defect-mediated dissolution of the condensed film is speculated to be the underlying cause of the unexpected slow kinetics.

Physicochemical, functional, and nutritional properties of flours from six navy bean varieties cultivated in two different locations in Manitoba, Canada were evaluated. The effect of genotype was found insignificant for protein content, ash content, zeta potential, and surface hydrophobicity among physicochemical properties (p > 0.05). For protein content, total starch content, and zeta potential of navy bean flours, environmental factors were found significant (p 0.05). In vitro protein digestibility results varied by genotype. Although in vitro protein digestibility corrected amino acid score values were significantly affected by genotype, environment, and their interactions similar to slowly digestible starch. The current study established a better understanding of the varietal effects of genotype and environment on a wide range of properties of navy bean flours.

Study question What is the reproductive outcome from ovarian tissue transplantation (OTT) from a single, experienced center. Summary answer The overall delivery rate was 41% (16/39) per woman and a total of 20 children to 39 women is expected. What is known already Ovarian tissue cryopreservation (OTC) is a well-established procedure for fertility preservation in girls and young women prior to gonadotoxic treatment and has shown to be a safe and promising method to restore fertility, with more than 200 healthy children born worldwide. Initial recovery of endocrine function is very high, although the longevity of the grafted tissue varies. The success of OTT is multifactorial, and important factors such as high age and poor ovarian reserve at OTC, as well as pelvic radiation are known to impair the chances of success. Study design, size, duration This is a single center, combined retro- and prospective cohort study including 40 women undergoing a total of 53 OTTs from the Fertility Clinic at Rigshospitalet University Hospital of Copenhagen, Denmark between 2003 and 2021. Participants/materials, setting, methods All women, who underwent OTT, were included in the study. End of follow up was December 31st, 2021. Information about diagnoses, gonadotoxic treatment, gynecologic (incl. endocrine parameters) and obstetric history was retrieved from medical records. Permission to obtain retrospective data from 1999 to 2020 was given by the Danish Patient Safety Authorities (jrn 3-3013-2790/1) and prospective data-collection was given by informed consent from the patients from 2020 and onwards. Main results and the role of chance Mean age at OTC was 28.5+5.5 years. Indications for OTC were malignant (n = 34) or benign diseases (n = 6). Mean time to first OTT was 4.2 years and mean age 33.0+5.4 years. At OTT, 19 women had POI (FSH>25 IU/L and amenorrhea), 10 were perimenopausal (intermittent FSH >25 IU/L) and 11 were low responders (AMH From 39 women with a pregnancy wish, 11 (28%) gave birth to a total of 15 children. In addition, 5 pregnancies are currently ongoing in the last trimester. The overall delivery rate was 51% (20/39) (including 5 ongoing) and 41% (16/39) per woman. Of 20 deliveries, 60% were conceived naturally and 40% from ART. Nineteen children were delivered following the first OTT. Four women had 2 children, of whom one had her second child following the second OTT. Initial activation of the grafted tissue, defined by a drop of FSH to Data on endocrine function of the grafted tissue will be presented at the meeting. Limitations, reasons for caution This study is based on information from medical records in public Danish hospitals, where information of all deliveries in Denmark is available. Pregnancies and deliveries outside Denmark might therefore not be included, why the total number could be slightly underestimated. Wider implications of the findings OTC with OTT is an efficient and encouraging way to restore fertility in a selected group of young women with a high risk of infertility following gonadotoxic treatment. Further, our data, from a specialized and experienced center, shows a good chance of livebirth and initial recovery of endocrine function. Trial registration number 3-3013-2790/1

A large amount of annual global carbon input is reported from pyrogenic organic matter (POM) production, motivating numerous research studies. Given that tetrabromobisphenol A (TBBPA) can be frequently exposed to possible fire scenarios, the potential long-term threats to the local environment are tied to the influence of interactions between POM and TBBPA. This study revealed the impacts of aging on POM and explored the contributions of surface alterations to the immobilization capacity of TBBPA. The freeze–thaw aging altered that surface with relatively low roughness, including both physical and chemical changes. Moreover, considering the surface alterations occurring during the aging process, the results based on asymmetrical factorial analysis showed that soil ions and dissolvable organic matter (DOM) play specific roles in TBBPA immobilization. The results further revealed that the introduction of DOM can create a different immobilization mechanism, in which the DOM can have a “throttling” effect that reduces the efficiency of active functional groups. However, in phototoxicity experiments, the vegetation exhibited vulnerability under the influence of POM to the toxic effects of TBBPA. These results suggest that sites with POM, whether manufactured or naturally produced, could be vulnerable to contaminants that hinder the growth of local vegetation.

Experimental results are reported to explain important aspects of why the classic gelator 1:3,2:4-dibenzylidene sorbitol (DBS) and five of its derivatives do or do not form gels in 23 solvents cove...

A dual infrared frequency comb spectrometer with heterodyne detection has been used to perform time-resolved electrochemical attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS). The measurement of the potential dependent desorption of a monolayer of a pyridine derivative (4-dimethylaminopyridine, DMAP) with time resolution as high as 4 μs was achieved without the use of step-scan interferometry. An analysis of the detection limit of the method as a function of both time resolution and measurement coadditions is provided and compared to step-scan experiments of an equivalent system. Dual frequency comb spectroscopy is shown to be highly amenable to time-resolved ATR-SEIRAS. Microsecond resolved spectra can be obtained with high spectral resolution and fractional monolayer detection limits in a total experimental duration that is 2 orders of magnitude less than the equivalent step-scan experiment.

There are substantial individual differences (resilience and vulnerability) in performance resulting from sleep loss and psychosocial stress, but predictive potential biomarkers remain elusive. Similarly, marked changes in the cardiovascular system from sleep loss and stress include an increased risk for cardiovascular disease. It remains unknown whether key hemodynamic markers, including left ventricular ejection time (LVET), stroke volume (SV), heart rate (HR), cardiac index (CI), blood pressure (BP), and systemic vascular resistance index (SVRI), differ in resilient vs. vulnerable individuals and predict differential performance resilience with sleep loss and stress. We investigated for the first time whether the combination of total sleep deprivation (TSD) and psychological stress affected a comprehensive set of hemodynamic measures in healthy adults, and whether these measures differentiated neurobehavioral performance in resilient and vulnerable individuals. Thirty-two healthy adults (ages 27–53; 14 females) participated in a 5-day experiment in the Human Exploration Research Analog (HERA), a high-fidelity National Aeronautics and Space Administration (NASA) space analog isolation facility, consisting of two baseline nights, 39 h TSD, and two recovery nights. A modified Trier Social Stress Test induced psychological stress during TSD. Cardiovascular measure collection [SV, HR, CI, LVET, BP, and SVRI] and neurobehavioral performance testing (including a behavioral attention task and a rating of subjective sleepiness) occurred at six and 11 timepoints, respectively. Individuals with longer pre-study LVET (determined by a median split on pre-study LVET) tended to have poorer performance during TSD and stress. Resilient and vulnerable groups (determined by a median split on average TSD performance) showed significantly different profiles of SV, HR, CI, and LVET. Importantly, LVET at pre-study, but not other hemodynamic measures, reliably differentiated neurobehavioral performance during TSD and stress, and therefore may be a biomarker. Future studies should investigate whether the non-invasive marker, LVET, determines risk for adverse health outcomes.

The long-term environmental effects of pyrogenic carbon have recently raised many concerns in terms of the fate and transport of emerging pollutants. This study explored the surface changes of geometric structure, functional groups, and site-energy distribution on pyrogenic carbon surfaces throughout a long-term physical aging process. Through synchrotron-based FTIR analysis, a homo-functionalization process was found to be the result of the consolidation of oxygen-containing groups with aromatic structures and the antagonization of other active hydroxyl groups in surface formation. Kinetic studies of TBBPA immobilization on pyrogenic carbon surfaces revealed a coverage process where TBBPA–humic acid, pyrogenic carbon–humic acid and pyrogenic carbon–TBBPA interactions can be formed. Isotherm analysis further indicated that the coverage process of natural organic matter (NOM) can enhance the processes of multilayer adsorption and thermodynamic alteration. Moreover, the results exhibited that site energies were dominated by OC–OH⋯OC–OH hydrogen bonds from NOM linkages, and O–H⋯O–H hydrogen bonds for TBBPA interactions were weakened by NOM coverage. Understanding such TBBPA interactions on carbonaceous porous materials will not only enrich the understanding of the transport of ionic pollutants under complex environmental conditions, but also support the evaluation of long-term environmental impacts of both naturally and artificially produced pyrogenic carbons.

The study explored the chronic toxicity of triclosan to green microalga Chlorococcum sp. under multiple interactions among multiple environmental conditions. This is the first study on chronic algal toxicity to combine synchrotron-based Fourier transform infrared spectromicroscopy, factorial analysis, principal component analysis, and stepwise-cluster analysis. Such a combination helps to reveal the toxic mechanism at the molecular level and explore the inner correlationship among multiple environmental conditions. In the 120-h test, nitrogen content became the most significant factor of the physiochemical properties. Some insignificant factors in the 48-h test became significant in the 120-h test. Temperature * nitrogen content, temperature * phosphorus content, and pH * phosphorus content were the most significant two-order interactions. Temperature * pH * NaCl concentration and temperature * NaCl concentration * phosphorus content were the most significant three-order interactions. More high-order interactions became significant in the 120-h test, indicating the complexity and impacts of all the factors may increase when time was extended. The chronic toxicity of triclosan presented more distinguishable variations among treatments based on biochemical alterations. These results demonstrate that the sensitivity and fragility of algae to triclosan can be amplified with time extension. Long-term exposure can be applied to better evaluate and predict the environmental toxicity behavior of triclosan. It can also help with environmental evaluation and risk management of real-world triclosan toxicity.

The heterogeneity of metal island films electrodeposited on conductive metal oxide modified internal reflection elements is shown to provide a variable attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) response. A self-assembled monolayer of a ferrocene-terminated thiol monolayer (FcC11SH) was formed on the gold islands covering a single substrate, which was measured using both a conventional spectrometer and a custom-built horizontal microscope. Cyclic voltammetry and ATR-SEIRAS results reveal that the FcC11SH-modified substrate undergoes a reversible electron transfer and an associated re-orientation of both the ferrocene/ferrocenium headgroup and the hydrocarbon backbone. The magnitude of the absorption signal arising from the redox changes in the monolayer, as well as the IR signature arising from the ingress/egress of the perchlorate counterions, is shown to depend significantly on the size of the infrared beam spot when using a conventional Fourier transform infrared spectrometer. By performing equivalent measurements on a horizontal microscope, the primary cause of the differences in the signal level is found to be the heterogeneity in the density of gold islands on the conductive metal oxide., Graphical Abstract

White matter degeneration in the central nervous system (CNS) has been correlated with a decline in cognitive function during aging. Ultrastructural examination of the aging human brain shows a loss of myelin, yet little is known about molecular and biochemical changes that lead to myelin degeneration. In this study, we investigate myelination across the lifespan in C57BL/6 mice using electron microscopy and Fourier transform infrared (FTIR) spectroscopic imaging to better understand the relationship between structural and biochemical changes in CNS white matter tracts. A decrease in the number of myelinated axons was associated with altered lipid profiles in the corpus callosum of aged mice. FTIR spectroscopic imaging revealed alterations in functional groups associated with phospholipids, including the lipid acyl, lipid ester and phosphate vibrations. Biochemical changes in white matter were observed prior to structural changes and most predominant in the anterior regions of the corpus callosum. This was supported by biochemical analysis of fatty acid composition that demonstrated an overall trend towards increased monounsaturated fatty acids and decreased polyunsaturated fatty acids with age. To further explore the molecular mechanisms underlying these biochemical alterations, gene expression profiles of lipid metabolism and oxidative stress pathways were investigated. A decrease in the expression of several genes involved in glutathione metabolism suggests that oxidative damage to lipids may contribute to age-related white matter degeneration.

In this study, the effect of wrinkled gold wires and films geometries on the surface plasmon response of these systems is studied. This investigation is conducted using electron energy loss spectroscopy (EELS) to map surface plasmon activities with high spatial and energy resolution. Metallic nanoparticle boundary element method (MNPBEM) simulations and polarization modulation infrared (PM-IR) microscopy are utilized as complementary methods. According to experimental results and simulations, wrinkled structures demonstrate a broadband surface plasmon response which is directly resulting from their geometrical complexities.

The performance of low-cost, microgroove silicon (Si)-based internal reflection elements (μ-groove IREs) for infrared chemical imaging of microfluidic devices is described. A custom-designed, horizontal microscope coupled with an imaging focal plane array area detector is described. After characterizing the inherent distortions of the microscope under wide field illumination, a checkerboard pattern lithographically printed on the principal reflection surface was imaged to determine the spatial resolution of the experimental setup which was approximately 14 μm per pixel. The image contains different regions of varying quality. Geometric ray tracing indicates that the different components in the image are caused by multiple beam paths through the μ-groove IRE. Regions of high image quality can be selected to cover a field of view with lateral dimensions of several hundred micrometers. Proof of concept chemical imaging with μ-groove IREs is demonstrated through the successful mapping of isotope exchange between two co-laminar flows of water and heavy water in a single microfluidic channel. A prospective on how imaging quality with near diffraction limited spatial resolution could be achieved is also provided.

Epithelial surfaces form critical barriers to the outside world and are continuously renewed by adult stem cells1. Whereas dynamics of epithelial stem cells during homeostasis are increasingly well understood, how stem cells are redirected from a tissue-maintenance program to initiate repair after injury remains unclear. Here we examined infection by Heligmosomoides polygyrus, a co-evolved pathosymbiont of mice, to assess the epithelial response to disruption of the mucosal barrier. H. polygyrus disrupts tissue integrity by penetrating the duodenal mucosa, where it develops while surrounded by a multicellular granulomatous infiltrate2. Crypts overlying larvae-associated granulomas did not express intestinal stem cell markers, including Lgr53, in spite of continued epithelial proliferation. Granuloma-associated Lgr5- crypt epithelium activated an interferon-gamma (IFN-γ)-dependent transcriptional program, highlighted by Sca-1 expression, and IFN-γ-producing immune cells were found in granulomas. A similar epithelial response accompanied systemic activation of immune cells, intestinal irradiation, or ablation of Lgr5+ intestinal stem cells. When cultured in vitro, granuloma-associated crypt cells formed spheroids similar to those formed by fetal epithelium, and a sub-population of H. polygyrus-induced cells activated a fetal-like transcriptional program, demonstrating that adult intestinal tissues can repurpose aspects of fetal development. Therefore, re-initiation of the developmental program represents a fundamental mechanism by which the intestinal crypt can remodel itself to sustain function after injury.

This study investigated the toxicity of triclosan to the green microalga Chlorococcum sp. under multiple environmental stressors. The interactions between triclosan and environmental stressors were explored through full two-way factorial, synchrotron-based Fourier transform infrared spectromicroscopy and principal component analyses. Phosphorus concentration, pH * phosphorus concentration, and temperature * pH * NaCl concentration were the most statistically significant factors under triclosan exposure. The variation of those factors would have a huge impact on biophysiological performances. It is interesting to find Chlorococcum sp. may become more resistant against triclosan in phosphorus-enriched environment. Besides, particular significant factors from multiple environmental stressors showed the impacts of triclosan on the corresponding response of Chlorococcum sp. owing to the specific structure and performance of biomolecular components. Moreover, two high-order interactions of temperature * pH * NaCl concentration and temperature * pH * NaCl concentration * phosphorus concentration had more contributions than others at the subcellular level, which could be attributed to the interactive complexity of biomolecular components. Due to cellular self-regulation mechanism and short exposure time, the biophysiological changes of Chlorococcum sp. were undramatic. These findings can help reveal the interactive complexity among triclosan and multiple environmental stressors. It is suggested that multiple environmental stressors should be considered during ecological risk assessment and management of emerging pollutants.

To determine the age of menopause after premenopausal unilateral oophorectomy (UO) and to establish whether UO at a young age leads to menopause at a younger age than if UO occurs at an older age.A cohort of 28 731 women, of whom 17 781 (62%) were menopausal, was investigated. Information on menopause was obtained from self-reported questionnaires. Surgical data were obtained from the National Patient Register to avoid recollection bias. Age of menopause after UO/not UO was determined using Kaplan-Meier curves. Cox regression was used to identify factors of importance for early menopause.UO was performed in 1148 women. Women with UO after the age of 45 years, premenopausal hysterectomy, bilateral oophorectomy and cancer were excluded, leaving 236 in the analysis. Menopause occurred 1.8 years earlier after UO compared to women with two intact ovaries (mean 49.5 vs. 51.3 years), and younger age at UO was significantly linearly correlated to younger age at menopause. UO (hazard ratio 1.23) and smoking (hazard ratio 1.12) significantly decreased the age of menopause.Premenopausal unilateral oophorectomy significantly reduces the age of menopause by 1.8 years. Younger age at UO leads to significantly younger age at menopause.

The high spatial resolution provided by synchrotron generated infrared (IR) radiation has been used to map spatiotemporal concentration profiles in the diffusion layer around a working electrode. An IR spectroelectrochemcial cell employing an inlaid band electrode has been developed that eliminates geometric issues with previous designs. The new cell was used to follow the diffusion layers produced by the reduction of ferricyanide and the oxidation of hydroquinone. Differences between the diffusion coefficients of ferricyanide and ferrocyanide determined here and the accepted literature are caused by the water-structure forming properties of different supporting electrolytes. The diffusion coefficients of hydroquinone and p- benzoquinone determined by diffusion layer mapping have been shown to be self-consistent with independently determined diffusion coefficients as measured using hydrodynamic linear sweep voltammetry. The consistency of the diffusion coefficients achieved for all species demonstrates that the spectroelectrochemical cell design allows for accurate monitoring of concentration profiles of species within electrochemical diffusion layers.

The immobilization of tetrabromobisphenol A (TBBPA) by pinecone-derived biochars at solid-liquid interface was investigated in this study. The surface structures and functional groups of biochars produced at different temperatures were characterized through synchrotron-assisted FTIR analysis. The adsorption isotherms were well described by the Langmuir model. The adsorption capacity of TBBPA varied as pH and TBBPA initial concentration changed and the molecular form of TBBPA predominated in pH 5–7 played an important role. The influences of inorganic fertilizer ions ( NH 4 + , PO 4 3 - and NO 3 - ) on the immobilization of TBBPA by pinecone biochars were revealed through fractional-factorial assisted analysis. The results indicated the main effects include negative effects of PO 4 3 - , positive effects of NH 4 + and insignificant effects of NO 3 - ions in immobilization and there are interactions among these ions, pH and biochar properties. The results of this study can help understand migration patterns of TBBPA and analyze the immobilization on biochars in the presence of inorganic fertilizer ions. It will have important implications for risk assessment and site remediation regarding overall environmental performance.

Modern hyperspectral imaging techniques can easily satisfy the representative statistical sampling requirements for any study providing large volume datasets. The job of understanding the collected...

Introduction There are substantial individual differences (resilience and vulnerability) in neurobehavioral performance from psychosocial stress and sleep loss. However, the time course of heart rate variability (HRV) across baseline, total sleep deprivation (TSD), the combination of TSD + psychological stress, and recovery has not been investigated; in addition, it remains unknown whether HRV and blood pressure (BP) differ in resilient vs. vulnerable individuals and predict individual differences in cognitive performance. Methods Thirty-one healthy adults (ages 27–53; mean±SD, 35.4±7.1y; 14 females) participated in a five-day experiment consisting of two 8h time-in-bed (TIB) baseline nights, 39h TSD, and two 8h-10h TIB recovery nights. A modified Trier Social Stress Test (TSST) induced psychological stress on the TSD day. Systolic and diastolic BP and HRV (derived from echocardiographic R-R interval) were obtained at six time points (pre-study, baseline, during TSD, during TSD after the TSST, after recovery, and post-study). Cognitively resilient (n=15) and vulnerable (n=16) groups were defined by a median split on 10-minute Psychomotor Vigilance Test (PVT) TSD performance [total lapses (>500ms response time) and errors]. Repeated measures ANOVA and post-hoc comparisons corrected for multiple testing, examined BP and HRV across time points between groups. Results HRV showed a significant time*group interaction: while resilient individuals had significantly lower HRV at pre-study compared to vulnerable individuals, their HRV increased above that of vulnerable individuals with TSD and with TSD + psychological stress. By contrast, systolic and diastolic BP did not show significant time*group interactions and did not predict cognitive vulnerability during TSD. Conclusion HRV differed between resilient and vulnerable individuals across TSD, psychological stress and recovery sleep and predicted individual differences in cognitive performance, whereby lower HRV during full-rested conditions predicted resilience to TSD and TSD + psychological stress. HRV, but not BP, is a reliable biomarker of sleep deprivation, psychological stress, and neurobehavioral vulnerability. Support NASA NNX14AN49G.

Steel pycnometers are used to determine density of liquids and gases at different temperatures and pressures. In order to determine this density with reliability, it is necessary to define the mass and the volume of this artifact with the best possible accuracy. This work proposes a methodology for calibrating this artifact, using the gravimetric method, in the pressure range from 1 bar (0.1 MPa) up to 96 bar (9.6 MPa), at the temperature of 20 °C, using Ethanol Pa (with 95% purity in volume). The results of uncertainty of volume for ambient conditions are shown here. The pycnometer volume equation was developed in the pressure range of 1 bar (0.1 MPa) up to 96 bar (9.6 MPa) for the temperature of 20 °C, whose uncertainty found was 0.055 cm3 (0.006%).

The use of synchrotron-sourced infrared radiation to map the electrochemical activity of a binary metal (Pt and Ni) alloy is demonstrated. The alloy is created in such a way that its metal concentration varies along one of its dimensions thus creating a continuum of electrocatalyst compositions on a single electrode. Localized methanol oxidation activity is determined spectroscopically by measuring the rate of CO2 production at variable positions along the alloy concentration gradient using an infrared microscope. Numerical simulations of the kinetically controlled reaction demonstrate that qualitative assessment of relative reaction rates is possible as long as the reaction is followed on time scales smaller than those that lead to diffusional broadening. Characterization of the alloy before and after electrochemical experiments reveals significant levels of base metal leaching. Highly dealloyed regions of the sample show the highest rates of methanol activity and have a final Ni atomic composition of ap...

Characterization of surface adsorbed species using infrared (IR) spectroscopy provides valuable information concerning interfacial chemical and physical processes. However, in situ infrared studies of surface areas approaching the IR diffraction limit, such as micrometer scale electrodes, require a hitherto unrealized means to obtain high signal-to-noise (S/N) spectra from femtomole quantities of adsorbed molecules. A major methodological breakthrough is described that couples the high brilliance of synchrotron-sourced infrared microscopy with attenuated total reflection surface enhanced infrared spectroscopy (ATR-SEIRAS). The method is shown to allow the spectral measurement of a monolayer of 4-methoxypyridine (MOP) adsorbed on a surface enhancing gold film electrode under fully operational electrochemistry conditions. A factor of 15 noise improvement is achieved with small apertures using synchrotron IR relative to a thermal IR source. The very low noise levels allow the measurement of high quality IR spectra of 2.5 fmol of molecules confined to a 125 μm

International audience; Molecular plasmonics relies on the development of conductive nanostructures to yield large local electromagnetic enhancement enabling the detection of molecules located in their vicinity. Although various spectroscopic techniques benefit from such enhancement, performing different spectroscopic measurements on the same platform, remains a challenge. As such, the rational design of structures capable of enhancement effects over a large spectral range, particularly from the visible to the mid-infrared, is of great interest. Herein, we have developed a series of metallic patterns, consisting of superimposed arrays of gold nanoprisms, that have the potential for surface-enhanced Raman spectroscopy (SERS), surface-enhanced fluorescence (SEF), and surface-enhanced infrared absorption (SEIRA). We first demonstrate that a modified version of the nanosphere lithography method can be used to fabricate such platforms. Patterns with selected sizes can further be produced by electron-beam lithography with virtually no defects, thus yielding tunable and precise optical resonances from the visible to the mid-infrared range. The hexagonal lattices were composed of smaller prisms (0.25 mu m prism base length) incorporated for SERS and SEF applications and larger triangles (1-2 mu m base size) for SEIRA purposes. The superimposed patterns display regions that are compatible with SEF, SERS, and SEIRA, thus opening promising applications for multispectral detection of molecules.

Introduction Individuals show robust resilience and vulnerability in neurobehavioral performance to sleep loss and stress. For the first time, we investigated the time course of two cardiovascular measurements, stroke volume (SV) and cardiac index (CI), both derived from echocardiography, across baseline, total sleep deprivation (TSD), the combination of TSD+psychological stress, and recovery. We also determined whether these variables differ in resilient vs. vulnerable individuals and whether they predict differential vulnerability in cognitive performance. Methods Thirty-one healthy adults (ages 27–53; mean±SD, 35.4±7.1y; 14 females) participated in a five-day experiment consisting of two 8h time-in-bed (TIB) baseline nights, 39h TSD, and two 8h-10h TIB recovery nights. A modified Trier Social Stress Test (TSST) was conducted on the TSD day to induce psychological stress. Echocardiographic measures of SV and CI were obtained at six time points (pre-study, baseline, during TSD, during TSD after the TSST, after recovery, and post-study). A median split of TSD performance [total lapses (>500 ms response time) and errors] on the 10-minute Psychomotor Vigilance Test (PVT), defined cognitively resilient (n=15) and vulnerable (n=16) groups. Repeated measures ANOVA and post-hoc comparisons corrected for multiple testing, examined SV and CI across time points between groups. Results There was a significant time*group interaction for SV: cognitively resilient individuals had greater SV during the five-day experiment. In addition, in both resilient and vulnerable individuals, SV increased with TSD and with TSD+psychological stress compared with baseline. Like SV, there was a significant time*group interaction for CI: resilient individuals had greater CI at all points of the experiment. Conclusion SV and CI differed between resilient and vulnerable individuals across TSD, psychological stress and recovery sleep. Greater SV and greater CI at baseline predicted resilience to TSD and TSD+psychological stress. CI and SV are novel physiological biomarkers of sleep loss, stress, and individual differences in cognitive performance. Support NASA NNX14AN49G.

We report the design and performance of a 3-electrode device for real time in situ scanning transmission X-ray microscopy studies of electrochemical processes under both static (sealed, non-flow) conditions and with a continuous flow of electrolytes. The device was made using a combination of silicon microfabrication and 3D printing technologies. The performance is illustrated by results of a study of copper deposition and stripping at a gold working electrode. X-ray absorption spectromicroscopy at the Cu 2p edge was used to follow the evolution as a function of potential and time of the spatial distributions of Cu(0) and Cu(i) species electro-deposited from an aqueous solution of copper sulphate. The results are interpreted in terms of competing mechanisms for the reduction of Cu(ii).

A custom-designed optical configuration compatible with the use of micromachined multigroove internal reflection elements (μ-groove IREs) for attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and imaging applications in microfluidic devices is described. The μ-groove IREs consist of several face-angled grooves etched into a single, monolithic silicon chip. The optical configuration permits individual grooves to be addressed by focusing synchrotron sourced IR light through a 150 µm pinhole aperture, restricting the beam spot size to a dimension smaller than that of the groove walls. The effective beam spot diameter at the ATR sampling plane is determined through deconvolution of the measured detector response and found to be 70 µm. The μ-groove IREs are highly compatible with standard photolithographic techniques as demonstrated by printing a 400 µm wide channel in an SU-8 film spin-coated on the IRE surface. Attenuated total reflection FT-IR mapping as a function of sample position across the channel illustrates the potential application of this approach for rapid prototyping of microfluidic devices.

Synchrotron infrared (SIR) radiation has been employed to map the diffusion layer surrounding a platinum working electrode. A thin-cavity transmission cell containing a raised, 12 μm platinum working electrode is employed to generate a two-dimensional diffusion space. The use of a prototypical redox system, i.e. the diffusion controlled reduction of ferricyanide (Ox) and concurrent production of ferrocyanide (Red), allows for a proof of principle evaluation of the viability of SIR for simultaneous mapping (in time and space) of the concentrations of species in the diffusion layer. Diffusion coefficients for the two species in the redox couple are extracted by comparing the experimental results with numerical simulations using finite elements. Absolute values of D Ox = 4.5 X 10 −6 cm 2 s −1 and D Red = 3.6 X 10 −6 cm 2 s −1 have been obtained which are systematically lower by about 30% than those independently determined from electrochemical measurements in the 0.10 M NaF supporting electrolyte. However, their ratio is in excellent agreement with accepted values. Deviations are attributed to heterogeneity in the SIR beam's intensity profile as well as difficulties in accurately accounting for the working electrode's pronounced edge effects. Implications for future IR spectroelectrochemical studies of chemical reactions in electrochemically generated diffusion layers are discussed.

This study explored the adsorption of Tetrabromobisphenol A (TBBPA) on pinecone-derived activated charcoal. The interactions between TBBPA and activated-charcoal surface, as well as the corresponding effects of functionality and adsorption capacities, were investigated through synchrotron FTIR, kinetics and surface functionality analyses. It was found that multiple acid functional groups and their interactive effects played important roles. The adsorption on activated charcoal from Yellow pinecone was favored by the surface with high polarity, low aromaticity, and low surface area. In comparison, adsorption on activated charcoal from Scot pinecone was favored by the surface with high aromaticity and high surface area. The adsorption capacity and removal efficiency were significantly dependent upon the contents of acid functional groups on charcoal surface. This study showed that the newly presented evidence of interactions between oxygen-containing functional groups and TBBPA will be helpful for exploring the treatment and transport of such a contaminant in the environment.

The result of interfacing step-scan spectroelectrochemistry with an IR microscope and synchrotron infrared (SIR) radiation is provided here. An external reflectance cell containing a 25 μm gold ultramicroelectrode is employed to achieve an electrochemical time constant less than one microsecond. The use of a prototypical electrochemical system, i.e., the mass-transport controlled reduction of ferricyanide, allows for a proof of principle evaluation of the viability of SIR for step-scan spectroelectrochemistry. An analysis of the importance of accounting for synchrotron source variation over the prolonged duration of a step-scan experiment is provided. Modeling of the material flux in the restricted diffusion space afforded by the external reflectance cell allows the quantitative IR results to be compared to theoretical predictions. The results indicate that only at very short times does linear diffusion within the cavity dominate the electrode response and the majority of the transient signal operates under conditions of quasi-hemispherical diffusion. The analytical information provided by the IR signal is found to be considerably less than that derived from the current response due the latter's pronounced edge effects. The results provide a detection limit of 36 fmol for step-scan SIR measurements of ferrocyanide. Implications for future IR spectroelectrochemical studies in the microsecond domain are discussed.

Acquisition of Legionnaires' disease is a serious complication of hospitalization. Rapid determination of whether or not the infection is caused by strains of Legionella pneumophila in the hospital environment is crucial to avoid further cases. This study investigated the use of whole-genome sequencing to identify the source of infection in hospital-acquired Legionnaires' disease. Phylogenetic analyses showed close relatedness between one patient isolate and a strain found in hospital water, confirming suspicion of nosocomial infection. It was found that whole-genome sequencing can be a useful tool in the investigation of hospital-acquired Legionnaires' disease.

Metallic nanostructures that exhibit tailored optical resonances spanning from the near to mid-infrared spectral range are of particular interest for spectroscopic and optical measurements in these spectral domains that can benefit from localized surface-enhancement effects. Plasmon resonances shifted in the near or mid-infrared range could be used to further enhance the excitation and/or the emission of an optical process. Surface-enhanced infrared absorption (SEIRA) is one of such processes and can particularly benefit from plasmon-enhanced local fields yielding an increase in sensitivity towards the detection of an analyte. Herein, we have fabricated a series of gold dendritic nanostructures, prepared by electron-beam lithography, that exhibit plasmon resonances spanning the near and mid-infrared spectral regions. We explore the influence of the number of branches of the dendritic structures, as well as the length of each generation together with the overall effect of the shape and symmetry on the resulting optical

Synchrotron infrared radiation has been successfully coupled through an infrared (IR) microscope to a thin-cavity external reflectance cell to study the diffusion controlled redox of a ferrocyanide solution. Excellent signal-to-noise ratios were achieved even at aperture settings close to the diffraction limit. Comparisons of noise levels as a function of aperture size demonstrate that this can be attributed to the high brilliance of synchrotron radiation relative to a conventional thermal source. Time resolved spectroscopic studies of diffusion controlled redox behavior have been measured and compared to purely electrochemical responses of the thin-cavity cell. Marked differences between the two measurements have been explained by analyzing diffusion in both the axial (linear) and radial dimensions. Whereas both terms contribute to the measured current and charge, only species that originate in the volume element above the electrode and diffuse in the direction perpendicular to the electrode surface are interrogated by IR radiation. Implications for the use of ultramicroelectrodes and synchrotron IR (SIR) to study electrochemical processes in the submillisecond time domain are discussed.

Although substantial information can be obtained from electrochemical measurements, much greater detail concerning molecular structure can be obtained by coupling such measurements with molecular spectroscopy. To this end, electrochemical and in situ surface enhanced infrared spectroscopy (SEIRAS) was performed to analyze 1,4-benzoquinone (BQ) terminated self-assembled monolayers. Monolayers were derived via the Michael addition of BQ to a pre-formed mixed monolayer composed of methyl and thiol terminated functionalities. This approach resulted in relatively robust but non-ideal redox-active monolayers. Spectroscopic and electrochemical measurements have allowed us to determine the pH dependence of both the apparent formal potential and the heterogeneous standard rate constant for proton coupled electron transfer (PCET) for this 2e−/2H+ redox system. While the former is in excellent agreement with predictions of step-wise PCET, the latter deviates from the expected kinetic response.

In this Letter, the received date should have been 23 March 2017 instead of 13 April 2018. Authors R.M.K. and O.D.K. were incorrectly denoted as ‘equally contributing’ authors. The labels for ‘control’ and ‘IFNγ’ in Extended Data Fig. 4g were reversed. These have been corrected online.

This work presents partial result of an introductory investigation on parameters of influence for the multiphase flow measurement reliability, which is going on in the Brazilian National Metrology Institute - Inmetro. Studies were performed with air-water mixture flowing inside a horizontal pipe. The flow pattern map of the experimental bench is identified, and parameters that influence for the flow pattern formation are analysed. Paper aims to disseminate knowledge on metrological bias on multiphase flow measurement. A brief overview on this theme is presented, along with the latest results of this research line at Inmetro.

Reliable pressure measurements are essential in all activities of society and industry. Indeed, the concern with traceability has notably improved and has received considerable interest due to the intensification of international trade, the need for environmental issues, safety and health requirements, for example in medical instruments, as well as devices for measuring the flow of Fluids Based on the pressure change. Differential pressure sensors are widely used in fluid flow processes, such as for monitoring the flow conditions and to determine flowrate or fluid velocity (example are the Pitot tube, Venturi, orifice plate etc.). This study focused on the precise generation of differential pressures in the range of 500 kPa to 20 MPa using gas-operated twin pressure balances. The metrological characteristics of a differential pressure manometer were evaluated.

The electrochemical reduction of benzoquinone involves a coupled transfer of protons and electrons. Theoretical treatments of proton-coupled electron transfer (PCET) indicate that both thermodynamic (apparent formal potential) and kinetic (apparent standard heterogeneous rate constants) quantities should be highly pH-dependent. Although there are several reports of quinone-derivatized self-assembled monolayers (SAMs) in the literature, no systematic studies on the pH dependence of the PCET kinetics have been reported. In this work, we outline a method to produce SAM-aminobenzoquinone monolayers starting from diluted monolayers of an amine-terminated SAM. The electroactive monolayer behaves as a nearly ideal Nernstian system (no interactions between redox centers). In neutral to weakly acidic electrolytes, the aminobenzoquinone can be reduced in a kinetically slow, two-electron, two-proton (2e2H) process, but in lower pH solutions, the observed reaction is consistent with an overall 2e3H transfer. Kinetic ...

Cyclic voltammetry and Fourier transform infrared external reflection spectroscopy (FTIR-ERS) have been used to study self-assembled monolayers of 4-mercaptobenzoic acid (4-MBA) formed on gold surfaces. Electrochemical studies demonstrate that the carboxylic acid head group of 4-MBA can be protonated or deprotonated by application of an electric potential to the gold substrate. This effect is highly dependent on the pH of the electrolyte in accordance with models previously developed for acid-terminated monolayers. The voltammetric response decreases with prolonged exposure to moderate strength electrolytes as cations exchange with the acid terminus. The formation of either sodium or potassium carboxylate salts occurs relatively slowly but the presence of Ca 2+ ions in the electrolyte immediately quenches the electric-field driven protonation/deprotonation process. The latter process leads to a very stable carboxylate salt film, which cannot be reprotonated by prolonged exposure to the pure incubating solvent. FTIR-ERS studies demonstrate that the observed electrochemical response of the 4-MBA SAMs is related to the degree of hydrogen bonding in the monolayer film. The addition of ultrapure acetic acid to the incubating solution leads to a film with reduced levels of intermolecular hydrogen bonding between MBA molecules. Electrochemically, the voltammetric peaks associated with the protonation/depronation process are greatly attenuated when the self-assembled films are formed from solutions containing 4-MBA and acetic acid.

An azimuthal rotatable sample cell, an electrochemical cell and a controlled humidity cell for in-situ scanning transmission X-ray microscopy (STXM) were developed at UVSOR-III Synchrotron (Okazaki, Japan). By using these sample cells, the polarization dependence of sodium titanate nanoribbons, in-situ electrochemistry of 0.1M FeSO4 solution, and in-situ morphological change of a functional polymer with changing humidity were successfully measured.