Magnetic-field-assisted optical fiber quantum temperature sensor with enhanced sensitivity.

In recent years, utilizing nitrogen-vacancy color centers in diamond for temperature sensing has drawn great attention. However, increasing the sensitivity has encountered challenges due to the intrinsic temperature-dependent energy level shift, i.e., temperature responsivity, being limited to -74 kHz/K. In this Letter, we take advantage of the magnetic field to regulate the energy level to enhance temperature sensitivity. The sensor is formed by adhering a micron-sized diamond on the end face of an optical fiber, and a small magnet is mounted at a certain distance with the diamond exploiting a cured polydimethylsiloxane block as the bridge. The temperature change leads to the variation of the distance between the diamond and the magnet, thus affecting the magnetic strength felt by the diamond. This finally contributes an additional temperature-induced energy level shift, giving rise to an enhanced sensitivity. Experimental results demonstrated the proposed scheme and achieved a 4.2-fold improvement in the temperature responsivity and a 2.1-fold enhancement in sensitivity. Moreover, the diamond and the fiber-optic integrated structure improve the portability of the sensor.

One-Pot Preparation of HCPT@IRMOF-3 Nanoparticles for pH-Responsive Anticancer Drug Delivery.

Metal-organic frameworks (MOFs) are considered to be promising materials for drug delivery. In this work, a Zinc-based MOF nanocomposite IRMOF-3 was introduced as a drug carrier for 10-hydroxycamptothecine (HCPT). Without an extra drug-loading process, a nanoscale drug delivery material HCPT@IRMOF-3 was prepared via one-pot synthesis. The composition and structure of the material were investigated, and the drug release character was measured. Compared with preparing IRMOF-3 first and loading the drug, the one-pot-prepared HCPT@IRMOF-3 exhibited a higher drug-loading capacity. The material presented pH-responsive release. The HCPT release rate at pH 5.0 was significantly higher than that at pH 7.4. The cytotoxicity experiments showed that IRMOF-3 was non-toxic, and HCPT@IRMOF-3 exhibited notable cytotoxicity to Hela and SH-SY5Y cells. One-pot synthesis is a simple and rapid method for the preparation of an MOF drug delivery system, and IRMOF-3 can be potentially used in pH-responsive drug delivery systems.

Increasing the amount of phosphoric acid enhances the suitability of Bradford assay for proteomic research.

The Bradford assay is one of the most commonly used methods for protein quantification. However, in proteomic research, the lysis buffer generally used for dissolving proteins can cause some interference to the assay. The dye reagent of classical Bradford assay contains 8.50% (w/v) phosphoric acid, which is an important factor relating to the color yield of the assay. In this study, the phosphoric acid content in dye reagent was increased to 9.35% (w/v), 10.20% (w/v), and 11.05% (w/v) to evaluate the changes of interference and the effects of lysis buffer on the interaction between proteins and dye reagent. Results show that lysis buffer not only causes background interference but also affects the protein-dye chromogenic process. Analysis of different components in the lysis buffer showed that carrier ampholyte is the main factor that introduces interference to the Bradford assay. Detergents are well-known interfering compounds in the Bradford assay, but CHAPS and octyl b-D-glucopyranoside only cause slight interference. When the amount of phosphoric acid was increased from 8.50%(w/v) to 10.20% (w/v), the sensitivity of the Bradford assay to proteins in lysis buffer was increased, and the interference delivered by lysis buffer was considerably reduced.

[Study on HPLC fingerprint of Hedyotis chrysotricha].

OBJECTIVE: To establish HPLC fingerprint of Hedyotis chrysotricha. METHODS: Hypersil BDS C18 (250 mm x 4.6 mm, 5 microm) column was used with methanol and 0.1% acetic acid solution as mobile phase in gradient mode, the flow rate was 1.0 mL/ min. The detection wavelength was 345 nm and the temperature of the column was set at 30 degrees C. Using ursolic acid as the reference standard, the mutual mode of Hedyotis chrysotricha containing nine common peaks was set up. The similarity of Hedyotis chrysotricha from different habitats was analyzed. RESULTS: The fingerprints of Hedyotis chrysotricha from different habitats were similar, but also had habitat characteristics. CONCLUSION: The HPLC fingerprint can be used for identification and quality control of Hedyotis chrysotricha.

[HPLC fingerprint of Calendula officinalis flower].

OBJECTIVE: To establish an HPLC fingerprint of Calendula officinalis flower for its quality control. METHODS: Hypersil ODS C18 column (250 mm x 4.6 mm, 5 µm) was used with acetonitrile and water as mobile phase in a gradient mode at the flow rate of 1.0 mL/min. The detection wavelength was 220 nm and the temperature of column was set at 35 degrees C. The similarity was analyzed with the Estimating System of Similarity on the Chinese Medicine Fingerprint Chromatogram. RESULTS: The HPLC fingerprint of Calendula officinalis flower containing eleven peaks was set up. The similarity of Calendula officinalis flower from different habitats was greater than 0.90. CONCLUSION: This method is easy and reliable, which can be used to judge the habitat and control the quality of Calendula officinalis flower.

Ternary Blends from Biological Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), Poly(propylene carbonate) and Poly(vinyl acetate) with Balanced Properties.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) has gained significant attention because of its biodegradability and sustainability. However, its expanded application in some fields is limited by the brittleness and low melt viscoelasticity. In this work, poly(vinyl acetate) (PVAc) was introduced into PHBH/poly(propylene carbonate) (PPC) blends via melt compounding with the aim of obtaining a good balance of properties. Dynamic mechanical analysis results suggested that PPC and PHBH were immiscible. PVAc was miscible with both a PHBH matrix and PPC phase, while it showed better miscibility with PHBH than with PPC. Therefore, PVAc was selectively localized in a PHBH matrix, reducing interfacial tension and refining dispersed phase morphology. The crystallization rate of PHBH slowed down, and the degree of crystallinity decreased with the introduction of PPC and PVAc. Moreover, the PVAc phase significantly improved the melt viscoelasticity of ternary blends. The most interesting result was that the remarkable enhancement of toughness for PHBH/PPC blends was obtained by adding PVAc without sacrificing the strength markedly. Compared with the PHBH/PPC blend, the elongation at the break and yield strength of the PHBH/PPC/10PVAc blend increased by 1145% and 7.9%, respectively. The combination of high melt viscoelasticity, toughness and strength is important for the promotion of the practical application of biological PHBH.

Dual-Phase Mixed Protonic-Electronic Conducting Hydrogen Separation Membranes: A Review.

Owing to the excellent properties of high selectivity, high thermal stability, and low cost, in the past twenty years, mixed protonic-electronic conducting hydrogen separation membranes have received extensive attention. In particular, dual-phase mixed protonic-electronic conducting membranes with high ambipolar conductivity are more attractive because of the high hydrogen permeability. This paper aimed to present a review of research activities on the dual-phase membranes, in which the components, the characteristics, and the performances of different dual-phase membranes are introduced. The key issues that affect the membrane performance such as the elimination of the inter-phase reaction, the combination mode of the phases, the phase ratio, and the membrane configuration were discussed. The current problems and future trends were simply recommended.

Nanodiamond-Based Optical-Fiber Quantum Probe for Magnetic Field and Biological Sensing.

Owing to the unique electronic spin properties, nitrogen-vacancy (NV) centers hosted in diamond have emerged as a powerful quantum tool for detecting various physical parameters and biological species. In this work, an optical-fiber quantum probe, configured by chemically modifying nanodiamonds on the surface of a cone fiber tip, is developed. Based on the continuous-wave optically detected magnetic resonance method and lock-in amplification technique, it is found that the sensing performance of probes can be engineered by varying the nanodiamond dispersion concentration and modification duration during the chemical modification process. Combined with a pair of magnetic flux concentrators, the magnetic field detection sensitivity has reached 0.57 nT/Hz1/2@1 Hz, a new record among the fiber magnetometers based on nanodiamonds. Taking Gd3+ as the demo, the capability of probes in paramagnetic species detection is also demonstrated experimentally. Our work provides a new approach to develop NV centers as quantum probes featuring high integration, multifunction, high sensitivity, etc.

Neutrophil mediated postoperative photoimmunotherapy against melanoma skin cancer.

Surgery is the primary treatment option for most melanoma; however, high tumor recurrence rate after surgical resection becomes the main cause of death in cancer patients. The development of efficient drug delivery nanosystems to inhibit postoperative tumor recurrence becomes very necessary. In the present study, IR780 molecules and TRP-2 peptide were encapsulated in the hydrophobic shell and hydrophilic interior of TAT peptide functionalized liposomes to form TLipIT NPs, which were further internalized into neutrophils (NEs) to achieve TLipIT/NEs. After being intravenously injected into postoperative B16F10-bearing mice, TLipIT/NEs could actively migrate toward the inflamed residual tumor and release TLipIT through neutrophil extracellular traps (NETs). Under NIR laser irradiation, the TLipIT exhibited both photothermal and photodynamic effects to induce immunogenic cell death for maturation of DCs, and simultaneously, to release TRP-2 peptide as a melanoma associated antigen to further strengthen the maturation of DCs, both of which prompts the activation of T cells and induces potent immune responses. TLipIT/NEs hold great potential for the inhibition of postoperative tumor recurrence.