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To address the problems of fringe compression in optical mirror measurement, this article shows a method for phase measuring deflectometry (PMD) of spiral fringes in polar coordinates. This method modulates the phase in two linearly independent directions in polar coordinates. Furthermore, spiral stripes have the unique property of spiral arms increasing with radius. It can solve the fringe compression problem at the convex mirror’s edge. Due to the periodicity of angles in polar coordinates, phase errors occur where the phase is zero. Therefore, this study studies a solution of extracting the wrapped phase boundary instead of the absolute phase boundary and dealing with the phase error points, effectively solving this problem. When the tangential and radial gradient data of the surface under test (SUT) were obtained, we used an accurate calculation for Zernike polynomial surface reconstruction in polar coordinates. This algorithm no longer uses the traditional Cartesian pixel arrangement to obtain the sampling points but reconstructs the horizontal and vertical pixels. The polar pixel matrix is used to obtain the fan pixel arrangement. On that basis, the geometric and numerical errors of traditional pixel arrangements can be avoided using Zernike polynomial surface reconstruction in polar coordinates. The experimental results demonstrate that the proposed method can improve measurement accuracy.

Biplanar deflectometry based on transparent screens (TSs) does not necessitate any movement of the screen or the addition of a spectroscope, mitigating the issues of complex calibration processes and reduced accuracy. This method usually only requires the calibration of the thickness $d$ and refractive index $\eta $ of the TS. However, traditional refraction parameter calibration methods require repeatedly moving the camera or standard flat mirror (Sfm), making the calibration process complex; to address this issue, the current article proposes a novel calibration method for the refractive parameters of TSs, which analyzes the optical path model of camera detection light refracting on TSs through inverse ray tracing. The mathematical model of the incident vector related to TS thickness $d$ and refractive index $\eta $ is also constructed. The refraction parameters of the TS can be obtained by inputting a known incident vector (constructed by a Sfm) into the model. This method does not necessitate repeated movement of the camera or the Sfm; the refraction parameters $d$ and $\eta $ of the TS can be calibrated in the calibration stage, greatly reducing the calibration complexity. Finally, a spherical mirror with a radius of curvature of 1000 mm is measured. The root-mean-square error (RMSE) is $3.56~\mu \text{m}$ when considering the effect of refraction, and $8.55~\mu \text{m}$ without considering the effect of refraction, which proves the effectiveness of the proposed method.

Optical microresonators supported whispering gallery modes (WGMs) are one of the most cost-effective platforms for optical frequency comb generated due to their advantages of ultra-high quality (Q) factor and ultra-low mode volume. In this paper, we report a portable and robust packaged silica spherical microcavity by melting the end of a standard single-mode fiber with ultra-high Q factor up to ${10}^8$, and theoretically and experimentally demonstrate a broadband optical frequency comb (OFC) generation including Kerr OFC and stimulated Raman comb. Kerr OFCs are separated by one, two, eight and twelve free spectral ranges corresponding to 1.4, 2.8, 11.2, and 16.8 nm, respectively. The transition between Kerr OFC and stimulated Raman comb is achieved by changing the pump laser power and the detuning frequency resulting from gain competition between modulation instability and Raman gain. Benefitting from the dispersion control and ultra-high Q factor persistence in our packaged microcavity, OFC can be adjusted continuously covering from S-band to C-band, L-band and U-band. We also explain these results by numerical simulations using a model framework combined with the Lugiato-Lefever equation and Raman response function.

Phase measuring deflectometry (PMD) is widely used to measure the surface of specular objects. The planar screen used in traditional PMD systems has the drawbacks of a small field of view of measurement and a large virtual image depth range. This problem can be effectively solved by using the curved screen. As the arc structure of the curved screen is different to the planar structure required in Zhang’s method, the existing methods mainly rely on the stereo vision of two cameras to obtain the screen position. This article presents a novel PMD based on a curved screen and single camera. A method of calibrating a curved screen by constructing a virtual planar screen is presented. The method only needs one camera to calibrate the curved screen directly with high accuracy. In addition, the change from planar screen to curved screen makes the traditional phase–gradient–height relation invalid. Based on the comprehensive analysis of space optical path models, a novel phase–gradient–height relation is presented. The relation is a general formula. It can be used for any curved screen, including the planar screen. Simulation and quantitative comparison experiments verify the accuracy and reliability of the proposed calibration method. The measurement results of concave mirror show that the proposed method has higher accuracy and a larger field of view in measuring specular objects than the traditional methods.

This study aimed to investigate the efficacy of colistin both alone and in combination with either meropenem or levofloxacin against CRAB clinical isolates. The OXA carbapenemase genes and multilocus sequence typing were detected after 35 CRAB isolates biochemical identification. Then, the minimum inhibitory concentrations, minimum bactericidal concentrations, antibiotic interactions of the test antibiotics, and synergistic effects were determined by the checkerboard method and time-kill assays. The chromosomal gene blaOXA-51-likewas detected in all isolates, and blaOXA-23-likeand blaOXA-24-likewere present in 91.4% and 25.7% of the isolates, respectively. The combination of colistin and meropenem displayed the highest rate of synergy (51.4%) against the 35 isolates, while the colistin-levofloxacin combination showed a higher rate of indifference interaction (22.9%) than that of the colistin-meropenem (8.6%) combination. The synergistic effect of colistin against the CRAB isolates was confirmed. The combination of colistin with meropenem is recommended against CRAB isolates.

Graphene membranes with subnanopores are considered to be the next-generation materials for water desalination and ion separation, while their performance is mainly determined by the relative ion selectivity of the pores. However, the origin of this phenomenon has been controversial in the past few years, which strongly limits the development of related applications. Here, using direct Au ion bombardment, we fabricated the desired subnanopores with average diameters of 0.8 ± 0.16 nm in monolayer graphene. The pores showed the ability to sieve K+, Na+, Li+, Cs+, Mg2+, and Ca2+cations, and the observed K+/Mg2+selectivity ratio was over 4. With further molecular dynamics simulations, we demonstrated that the ion selectivity is primarily attributed to the dehydration process of ions that can be quantitatively described by the ion-dependent free-energy barriers. Hopefully, this work is helpful in further enhancing the ion selectivity of graphene nanopores and also presenting a new paradigm for improving the performance of other nanoporous atomically thin membranes, such as MXenes and MoS2.

Salinity gradient energy is a kind of the Gibbs free energy of mixing, and it is a clean, sustainable, and renewable energy source which is projected of the capacity to generate about 2.6 TW of electricity from all rivers flowing into the sea. However, the current technology to convert the salinity gradient energy to electricity suffers from low conversion efficiency, which results in a low output power density. In this work, we develop a new type of the graphene reverse electrodialysis (GRED) device which can efficiently convert the salinity gradient energy into electricity. The GRED device is fabricated based on a simple and straightforward ion irradiation perforation approach, and it is demonstrated to exhibit a record-high energy conversion efficiency of 39% and a record-high output power density of 27 W/m2at room temperature, manifesting its high promise for the clean energy harvesting from the salinity gradient. Theoretical simulations based on molecular dynamics and continuum theory further show that the charge at the pore edge is of crucial importance for achieving high ion selectivity. In light of this finding, we show that the output power density of GRED can be further boosted to 126 W/m2if it is operated at a slightly elevated temperature of 47 °C, for which the heating could be from industrial thermal waste in a practical sense.

Supramolecular electronics provide an opportunity to introduce molecular assemblies into electronic devices through a combination of noncovalent interactions such as [π···π] and hydrogen-bonding interactions. The fidelity and dynamics of noncovalent interactions hold considerable promise when it comes to building devices with controllable and reproducible switching functions. Here, we demonstrate a strategy for building electronically robust switches by harnessing two different noncovalent interactions between a couple of pyridine derivatives. The single-supermolecule switch is turned ON when compressing the junction enabling [π···π] interactions to dominate the transport, while the switch is turned OFF by stretching the junction to form hydrogen-bonded dimers, leading to a dramatic decrease in conductance. The robustness and reproducibility of these single-supermolecule switches were achieved by modulating the junction with Ångström precision at frequencies of up to 190 Hz while obtaining high ON/OFF ratios of ∼600. The research presented herein opens up an avenue for designing robust bistable mechanoresponsive devices which will find applications in the building of integrated circuits for microelectromechanical systems.

The blade is a key component of the aero-engine. As the blade must have a precise size, accurate shape, the three-dimensional profiling measurement of the blade is very important. Its complexity and diversity bring considerable difficulty to the measurement. The optical triangulation method is used in the profiling measurement of the blade in the paper. The coded technique based on gray-code combined with the phase-shift method is used. The three-dimensional point cloud of blade is obtained in this method. A high accuracy of three-dimensional profiling measurement of the blade is achieved, and the measurement accuracy reaches 0.05 mm.

To evaluate the potential of dynamic CT enhanced by iohexol or a novel macromolecular contrast agent, PEG12000-Gen4-triiodo, to monitor microvascular changes in tumors treated with the angiogenesis inhibitor bevacizumab.

To evaluate the potential of quantitative assays of vascular characteristics based on dynamic contrast-enhanced magnetic resonance imaging (MRI) using a macromolecular contrast medium (MMCM) to search for and measure effects of dimethyl sulfoxide (DMSO) on cancer vasculature with microscopic correlations.

We sought to compare magnetic resonance imaging (MRI) enhancement using 4 novel macromolecular polyethyleneglycol (PEG)-based cascade-polymer gadolinium contrast agents (macromolecular contrast media) in normal soft tissues and a breast cancer model.

The purpose of this study was to design, synthesize, and initially characterize a representative set of novel constructs for large-molecular radiographic/computed tomography (CT) contrast agents, intended for a primarily intravascular distribution. A new assembly of well-known and biocompatible components consists of paired, symmetrical dendritic polylysines initiated from both ends of a poly(ethylene glycol) (PEG) core, yielding an array of multiple free amino groups to which were conjugated highly soluble and stable triiodophthalamide (“triiodo”) moieties. An array of six dendritic contrast agents was synthesized originally, using three different PEG cores (3, 6, 12 kDa) with t-Boc lysine-generated dendrimer “amplifiers” (from three to five generations) containing 16 to 64 amino groups for conjugation with reactive triiodo moieties. A clinically used, nonionic, small molecular CT contrast agent, iobitridol, was derivatized via a hydroxyl protection/deprotection strategy, introducing a new carboxyl group available for conjugation to the lysine amino groups of dendrimers. Final products were purified by size exclusion chromatography and characterized by NMR, UV, HPLC, and elemental analysis. Preliminary evaluations were conducted for physicochemical characterization and in vivo CT contrast enhancement in a rat model. All six iodinated PEG-core dendrimer conjugates were synthesized in good yields, with a high degree of size monodispersity, large apparent molecular weight, favored physicochemical properties. A representative compound, PEG12000-carbamate-Gen4-IOB conjugate, 27% (w%) rich in iodine, demonstrated a desirable strong and persistent intravascular enhancement with a monoexponential blood half-life of approximately 35 min assayed by dynamic CT imaging and also showed high water solubility (>550 mg/mL at 25 °C), large apparent molecular size (comparable to a 143-kDa protein), high hydrophilicity (butanol−water partition coefficient 0.015), and stability to autoclaving conditions. This study showed the synthetic feasibility, desired basic characteristics, and potential utility for CT contrast enhancement achieved with a new type of iodinated, large-molecular PEG-core dendritic construct. Further development of this class of macromolecular contrast agents will be required to define the optimal formulation, pharmacology, safety profile, and the full range of diagnostic applications including tumor microvascular quantitative characterization by CT imaging.

We sought to compare the ability of 3 ultrasmall superparamagnetic iron oxides (USPIOs) to detect and characterize antigen-induced arthritis with MR imaging.

The objective of this study was to evaluate computed tomography (CT) enhancement characteristics for a new iodinated macromolecular contrast medium (MMCM), PEG12000-Gen4-triiodo, for angiographic effect and for assessment of abnormal vascular permeability in cancer.

Macromolecular contrast medium-enhanced magnetic resonance imaging was applied to monitor the effect of matrix metalloprotease (MMP) inhibition on microvascular characteristics of human breast cancers implanted in athymic rats. Twice-daily intraperitoneal administration of Prinomastat over 1.5 days induced significant declines in MRI-assayed microvascular permeabilities (p<0.05); but this leak suppression effect had extinguished by the 10thday of MMP treatment using the same dose and time schedule. Results demonstrate that Prinomastat produces a rapid but transient decrease in tumor vascular permeability. Contrast-enhanced MRI using macromolecular contrast medium may prove useful as a biomarker for the dynamic MMP biological effect in cancers.

The structure of a mimetic of sialyl Lewis^X, namely 3-[2-(α-D-mannopyranosyloxy)phenyl]phenylacetic acid, was coupled to diethylenetriaminepentaacetic acid (DTPA) via a flexible alkyl spacer and the amide linkage. The overall yield of the eleven-step synthesis starting from 3-bromophenylacetic acid was 4−8%. This new ligand is expected to target inflammation sites through specific interactions with selectins, the adhesion molecules expressed on the vascular endothelium in pathological conditions. In particular, complexation of the DTPA moiety with gadolinium or radionuclides could produce contrast agents for medical imaging. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

The grating fringe on the reference plane is broadened in the intersecting axis system because of oblique-angle projection. In order to solve this problem, we study the theoretical model of the temporal phase unwrapping method based on the fringe cycle correction. We also study the 3D shape measurement theoretical model of the larger complex objects after considering the coordinate deviation and lens distortion. Experimental results demonstrate that the fringe cycle on the reference plane can be corrected to a constant value, the lens distortion can be corrected, and 3D shape of larger complex objects can be accurately measured.