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Background/Objectives: Laser Doppler flowmetry enables rapid and simple measurement of microcirculation. However, variations in probe configuration can influence signal acquisition, making it essential to understand each probe’s characteristics when selecting equipment for specific physiological assessments. Therefore, this study aimed to compare perfusion measurements obtained with single-fiber (VP1T) and multi-fiber (VP1T/7) probes and to evaluate the effects of normalization strategies. Methods: Nine healthy female volunteers were recruited. Probes were positioned on the palmar aspects of the index and middle fingers of both hands while participants underwent a standardized brachial artery occlusion protocol. Data are presented as mean ± standard error of the mean. Correlations were assessed using Pearson’s correlation coefficient. Coefficients of variation (CV) and intraclass correlation coefficients were calculated. Baseline normalization was applied to measurements. Statistical analyses were performed using Student’s t-test, with significance set at p < 0.05. Results: Analysis of the full protocol revealed significant positive correlations between probes, indicating consistent temporal perfusion patterns. The VP1T/7 probe yielded significantly higher perfusion values than the VP1T probe, although both exhibited similar CVs. Inter-probe reliability was good, and intra-probe reproducibility ranged from good to excellent, particularly for the VP1T/7 probe. During the reperfusion phase, significant differences were observed only for ipsilateral measurements obtained with the VP1T probe. Normalization effectively reduced variability, and significant differences during reperfusion were detected with both probes. Conclusions: Although the multi-fiber probe consistently recorded higher perfusion values, normalization was essential to reduce variability and to enhance the detection of microvascular reactivity parameters.

Functional near-infrared spectroscopy (fNIRS) is an imaging technique that relies on the principle of shining near-infrared light through tissue to detect changes in hemodynamic activation. An important methodological issue encountered is the creation of optimized probe geometry for fNIRS recordings. Here, across three experiments, we describe and validate a processing pipeline designed to create an optimized, yet scalable probe geometry based on selected regions of interest (ROIs) from the functional magnetic resonance imaging (fMRI) literature. In experiment 1, we created a probe geometry optimized to record changes in activation from target ROIs important for visual working memory. Positions of the sources and detectors of the probe geometry on an adult head were digitized using a motion sensor and projected onto a generic adult atlas and a segmented head obtained from the subject's MRI scan. In experiment 2, the same probe geometry was scaled down to fit a child's head and later digitized and projected onto the generic adult atlas and a segmented volume obtained from the child's MRI scan. Using visualization tools and by quantifying the amount of intersection between target ROIs and channels, we show that out of 21 ROIs, 17 and 19 ROIs intersected with fNIRS channels from the adult and child probe geometries, respectively. Further, both the adult atlas and adult subject-specific MRI approaches yielded similar results and can be used interchangeably. However, results suggest that segmented heads obtained from MRI scans be used for registering children's data. Finally, in experiment 3, we further validated our processing pipeline by creating a different probe geometry designed to record from target ROIs involved in language and motor processing. •New processing pipeline was developed for creating optimal and scalable probe geometry for fNIRS.•Probe geometry was created for an adult head and a child's head for investigating visual working memory.•At least 17 regions of interest intersected with channels from adult and child probe geometries.•Processing pipeline was validated for another study investigating motor and language functions.

In the last decade, DNA-based tension sensors have made significant contributions to the study of the importance of mechanical forces in many biological systems. Albeit successful, one shortcoming of these techniques is their inability to reversibly measure receptor forces in a higher regime (that is, >20 pN), which limits our understanding of the molecular details of mechanochemical transduction in living cells. Here, we developed a reversible shearing DNA-based tension probe (RSDTP) for probing molecular piconewton-scale forces between 4 and 60 pN transmitted by cells. Using these probes, we can easily distinguish the differences in force-bearing integrins without perturbing adhesion biology and reveal that a strong force-bearing integrin cluster can serve as a ‘mechanical pivot’ to maintain focal adhesion architecture and facilitate its maturation. The benefits of the RSDTP include a high dynamic range, reversibility and single-molecule sensitivity, all of which will facilitate a better understanding of the molecular mechanisms of mechanobiology. Li et al. develop reversible shearing DNA-based tension probes to quantify molecular piconewton-scale forces, estimate the number of mechanically active receptors with single-molecule sensitivity and study mechanisms of force transduction in live cells.

Spin-ordered electronic states in hydrogen-terminated zigzag nanographene give rise to magnetic quantum phenomena 1 , 2 that have sparked renewed interest in carbon-based spintronics 3 , 4 . Zigzag graphene nanoribbons (ZGNRs)—quasi one-dimensional semiconducting strips of graphene bounded by parallel zigzag edges—host intrinsic electronic edge states that are ferromagnetically ordered along the edges of the ribbon and antiferromagnetically coupled across its width 1 , 2 , 5 . Despite recent advances in the bottom-up synthesis of GNRs featuring symmetry protected topological phases 6 – 8 and even metallic zero mode bands 9 , the unique magnetic edge structure of ZGNRs has long been obscured from direct observation by a strong hybridization of the zigzag edge states with the surface states of the underlying support 10 – 15 . Here, we present a general technique to thermodynamically stabilize and electronically decouple the highly reactive spin-polarized edge states by introducing a superlattice of substitutional N-atom dopants along the edges of a ZGNR. First-principles GW calculations and scanning tunnelling spectroscopy reveal a giant spin splitting of low-lying nitrogen lone-pair flat bands by an exchange field (~850 tesla) induced by the ferromagnetically ordered edge states of ZGNRs. Our findings directly corroborate the nature of the predicted emergent magnetic order in ZGNRs and provide a robust platform for their exploration and functional integration into nanoscale sensing and logic devices 15 – 21 . Decoupling spin-polarized edge states using substitutional N-atom dopants along the edges of a zigzag graphene nanoribbon (ZGNR) reveals giant spin splitting of a N-dopant edge state, and supports the predicted emergent magnetic order in ZGNRs.

The spatial resolutions of even the most sensitive isotope analysis techniques based on light or ion probes are limited to a few hundred nanometres. Although vibrational spectroscopy using electron probes has achieved higher spatial resolution 1 – 3 , the detection of isotopes at the atomic level 4 has been challenging so far. Here we show the unambiguous isotopic imaging of 12 C carbon atoms embedded in 13 C graphene and the monitoring of their self-diffusion via atomic-level vibrational spectroscopy. We first grow a domain of 12 C carbon atoms in a pre-existing crack of 13 C graphene, which is then annealed at 600 degrees Celsius for several hours. Using scanning transmission electron microscopy–electron energy loss spectroscopy, we obtain an isotope map that confirms the segregation of 12 C atoms that diffused rapidly. The map also indicates that the graphene layer becomes isotopically homogeneous over 100-nanometre regions after 2 hours. Our results demonstrate the high mobility of carbon atoms during growth and annealing via self-diffusion. This imaging technique can provide a fundamental methodology for nanoisotope engineering and monitoring, which will aid in the creation of isotope labels and tracing at the nanoscale. Vibrational electron energy-loss spectroscopy is used to distinguish two stable isotopes of carbon and to monitor their diffusion with subnanometre spatial resolution.

This article discusses one of the possible roles that gender could have in the Agree operation (Chomsky 2000, 2001). Based on the analysis of the PCC in Spanish developed in Camacho Ramírez (2024), in which, in the context of a ditransitive verb, gender would be necessary to guide the other probes of v* toward a specific goal, it is proposed here that gender should also guide the probes of the v* of a transitive verb.

Indenofluorenes are non-benzenoid conjugated hydrocarbons that have received great interest owing to their unusual electronic structure and potential applications in nonlinear optics and photovoltaics. Here we report the generation of unsubstituted indeno[1,2- a ]fluorene on various surfaces by the cleavage of two C–H bonds in 7,12-dihydroindeno[1,2- a ]fluorene through voltage pulses applied by the tip of a combined scanning tunnelling microscope and atomic force microscope. On bilayer NaCl on Au(111), indeno[1,2- a ]fluorene is in the neutral charge state, but it exhibits charge bistability between neutral and anionic states on the lower-workfunction surfaces of bilayer NaCl on Ag(111) and Cu(111). In the neutral state, indeno[1,2- a ]fluorene exhibits one of two ground states: an open-shell π -diradical state, predicted to be a triplet by density functional and multireference many-body perturbation theory calculations, or a closed-shell state with a para -quinodimethane moiety in the as -indacene core. We observe switching between open- and closed-shell states of a single molecule by changing its adsorption site on NaCl. Switching the magnetic state of a polycyclic conjugated hydrocarbon in a reversible and controlled manner is challenging. Now, by means of single-molecule scanning probe microscopy, an indenofluorene isomer on ultrathin NaCl films has been shown to adopt both open- and closed-shell states. Furthermore, bidirectional switching between the two states is achieved by changing the adsorption site of the molecule.

Water exists in high- and low-density amorphous ice forms (HDA and LDA), which could correspond to the glassy states of high-(HDL) and low-density liquid (LDL) in the metastable part of the phase diagram. However, the nature of both the glass transition and the high-to-low-density transition are debated and new experimental evidence is needed. Here we combine wide-angle X-ray scattering (WAXS) with X-ray photon-correlation spectroscopy (XPCS) in the small-angle X-ray scattering (SAXS) geometry to probe both the structural and dynamical properties during the high-to-low-density transition in amorphous ice at 1 bar. By analyzing the structure factor and the radial distribution function, the coexistence of two structurally distinct domains is observed at T = 125 K. XPCS probes the dynamics in momentum space, which in the SAXS geometry reflects structural relaxation on the nanometer length scale. The dynamics of HDA are characterized by a slow component with a large time constant, arising from viscoelastic relaxation and stress release from nanometer-sized heterogeneities. Above 110 K a faster, strongly temperature-dependent component appears, with momentum transfer dependence pointing toward nanoscale diffusion. This dynamical component slows down after transition into the low-density form at 130 K, but remains diffusive. The diffusive character of both the high- and low-density forms is discussed among different interpretations and the results are most consistent with the hypothesis of a liquid–liquid transition in the ultraviscous regime.

Reliable spatially resolved compositional analysis through atom probe tomography requires an accurate placement of the detected ions within the three-dimensional reconstruction. Unfortunately, for heterogeneous systems, traditional reconstruction protocols are prone to position some ions incorrectly. This stems from the use of simplified projection laws which treat the emitter apex as a spherical cap, although the actual shape may be far more complex. For instance, sampled materials with compositional heterogeneities are known to develop local variations in curvature across the emitter due to their material phase specific evaporation fields. This work provides three pivotal precursors to improve the spatial accuracy of the reconstructed volume in such cases. First, we show scanning probe microscopy enables the determination of the local curvature of heterogeneous emitters, thus providing the essential information for a more advanced reconstruction considering the actual shape. Second, we demonstrate the cyclability between scanning probe characterization and atom probe analysis. This is a key ingredient of more advanced reconstruction protocols whereby the characterization of the emitter topography is executed at multiple stages of the atom probe analysis. Third, we show advances in the development of an electrostatically driven reconstruction protocol which are expected to enable reconstruction based on experimental tip shapes.