Application of a WGM optical fiber probe fabricated by 3D printing technology for glucose concentration measurement

This study proposes a method for manufacturing a whispering gallery mode (WGM) optical fiber probe used for measuring glucose. The principle of the WGM optical fiber probe consists of the bending interference that occurs between the core mode and cladding mode. 3D printing technology was used to create a mold for the optical fiber sensor so that the bent optical fiber sensor was fixed within the mold to ensure a stable bend radius. This method of fabrication allows for easier installation and replacement of the resulting optical fiber compared to WGM optical fiber sensors fabricated by traditional methods. The results of the concentration test showed that as the glucose aqueous solution concentration increased from 0 to 10%, the wavelength was red shifted and the transmission loss gradually increased. At a bend radius of 3.1 mm and an etching diameter of 46 μm, the wavelength sensitivity was 1.475 nm/% and the R-squared value was 0.983, indicating an extremely high sensitivity. These results confirm that the WGM optical fiber probe created in this study can be used to measure glucose concentrations with high sensitivity, and that it is relatively easy to manufacture, install, and replace. Therefore, the proposed WGM optical fiber probe exhibits good performance and is suitable for use as a glucose concentration sensor.     

NEW STRAIN GRADIENT THEORY AND ANALYSIS

A new strain gradient theory which is based on energy nonlocal model is proposed in this paper, and the theory is applied to investigate the size effects in thin metallic wire torsion, ultra-thin beam bending and micro-indentation of polycrystalline copper. First, an energy nonlocal model is suggested. Second, based on the model, a new strain gradient theory is derived. Third, the new theory is applied to analyze three representative experiments.     

Nitrate and perchlorate salts of a silver(I) complex from 5-methyl-2-(2,3-diaza-4-(5-methyl-2-thienyl)buta-1,3-dienyl)thiophene

Bis(5-methyl-2-(2,3-diaza-4-(5-methyl-2-thienyl)buta-1,3-dienyl)thiophene) silver(I) complex was synthesized in high yield by refluxing 5-methyl-2-(2,3-diaza-4-(5-methyl-2-thienyl)buta-1,3-dienyl)thiophene (L) with silver nitrate or silver perchlorate in anhydrous acetonitrile. The product thus formed was well characterized by NMR, IR, UV–Vis and mass spectroscopies as well as elemental analysis and electrochemical analysis. Molecular structures of compounds L, [L₂Ag]NO₃ and [L₂Ag]ClO₄ were determined by single crystal X-ray diffraction analysis. It was found that the C=N double bond of the ligand rotated during the course of ligand coordination in the case of the perchlorate salt but not in the case of the nitrate salt.     

The synthesis and properties of side‐chain liquid‐crystal polymers with a chiral center

The synthesis and mesomorphic properties of six monomers and six side‐chain liquid‐crystal polymers with a chiral center are described. The polysiloxanes were prepared by the hydrosilation of monomers with poly(hydromethylsiloxane)s. Most of the polymers exhibit a wide range of the chiral smectic C phase (SmC*). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1609–1617, 2000     

Recent progress on the chiral unitary approach to meson meson and meson baryon interactions

We report on recent progress on the chiral unitary approach, analogous to the effective range expansion in Quantum Mechanics, which is shown to have a much larger convergence radius than ordinary chiral perturbation theory, allowing one to reproduce data for meson meson interaction up to 1.2 GeV. Applications to physical processes so far unsuited for a standard chiral perturbative approach are presented. Results for the extension of these ideas to the meson baryon sector are discussed, together with applications to kaons in a nuclear medium and K⁻ atoms.     

Micro FTIR Mapping of Nanometer Ferroelectric Polymer Films

Summary: Highly crystalline ferroelectric polymer films [vinyidene fluoride and trifluoroethylene, β‐P(VDF‐TrFE), 260–15 nm thick] were characterized with FTIR reflectance‐transmission microspectroscopy (FTIR‐RTM) mapping technique (400 µm × 400 µm spatial resolution). The amorphous and crystalline fractions were identified locally. FTIR‐RTM maps (1 cm² area) provided a unique in‐depth view of the ultrathin films. Lower film thickness suppressed growth of the crystalline phase. Increased content of amorphous phase lead to non‐uniform films with degraded ferroelectric behavior.

FTIR‐RTM maps of the distribution of the amorphous phase in the 80 and 35 nm films.     

Comprehensive profiles and diagnostic value of menopausal-specific gut microbiota in premenopausal breast cancer

In Western countries, breast cancer tends to occur in older postmenopausal women. However, in Asian countries, the proportion of younger premenopausal breast cancer patients is increasing. Increasing evidence suggests that the gut microbiota plays a critical role in breast cancer. However, studies on the gut microbiota in the context of breast cancer have mainly focused on postmenopausal breast cancer. Little is known about the gut microbiota in the context of premenopausal breast cancer. This study aimed to comprehensively explore the gut microbial profiles, diagnostic value, and functional pathways in premenopausal breast cancer patients. Here, we analyzed 267 breast cancer patients with different menopausal statuses and age-matched female controls. The α-diversity was significantly reduced in premenopausal breast cancer patients, and the β-diversity differed significantly between breast cancer patients and controls. By performing multiple analyses and classification, 14 microbial markers were identified in the different menopausal statuses of breast cancer. Bacteroides fragilis was specifically found in young women of premenopausal statuses and Klebsiella pneumoniae in older women of postmenopausal statuses. In addition, menopausal-specific microbial markers could exhibit excellent discriminatory ability in distinguishing breast cancer patients from controls. Finally, the functional pathways differed between breast cancer patients and controls. Our findings provide the first evidence that the gut microbiota in premenopausal breast cancer patients differs from that in postmenopausal breast cancer patients and shed light on menopausal-specific microbial markers for diagnosis and investigation, ultimately providing a noninvasive approach for breast cancer detection and a novel strategy for preventing premenopausal breast cancer.Subject terms: Bacterial genetics, Breast cancer     

Size and Shape Effects of Near-Infrared Light-Activatable Cu2(OH)PO4 Nanostructures on Phototherapeutic Destruction of Drug-Resistant Hypoxia Tumors

Development of simple, robust, and noninvasive therapeutic approaches to treat cancers and improve survival rates is a grand challenge in clinical biomedicine. In particular, the sizes and shape of the nanomaterials play a vital role in dictating their biodistribution and clearance pathways. It remains elusive how the size and shape of a nanomaterial affect its therapeutic efficacy in cancer diagnosis and treatments. To tackle the above problem, the effects of size and shape of Cu₂(OH)PO₄ nanostructures (nanosheets and quantum dots) on the photodynamic therapy (PDT) in destroying malignant drug-resistant lung tumors and on combating the tumor hypoxia problem are investigated and compared. The photocatalytic mechanism of Cu₂(OH)PO₄ nanostructures mainly involves the generation of reactive oxygen species (ROS), such as hydroxyl radical (^·OH) and singlet oxygen (¹O₂). Under an oxygen deprivation condition, Cu₂(OH)PO₄ nanosheets still can generate OH radicals to kill cancer cells upon near-infrared (NIR) light irradiation. Overall, in vitro and in vivo experiments show that Cu₂(OH)PO₄ nanosheets can overcome tumor hypoxia problems and effectively mediate dual modal PDT and photothermal therapeutic (PTT) effects on destruction of NCI-H23 lung tumors in mice using ultralow doses (350 mW cm⁻²) of NIR (915 nm) light.