Obstructive sleep apnea affects lacrimal gland function

Purpose: To determine the effect of obstructive sleep apnea syndrome (OSA) on lacrimal gland function and its mechanism. Methods: Male mice aged seven to eight weeks were housed in cages with cyclic intermittent hypoxia to mimic OSA, and the control group was kept in a normal environment. Slit-lamp observation, fluorescein staining, and corneal sensitivity detection are used to assess cornea changes. Tear secretion was detected by phenol red cotton thread, and the pathological changes of lacrimal gland were observed by hematoxylin and eosin staining, oil red O staining, cholesterol and triglyceride kits, immunofluorescence staining, immunohistochemical staining, real-time polymerase chain reaction, transmission electron microscopy, and Western blot. Results: Studies revealed a decreased tear secretion, corneal epithelial defects and corneal hypersensitivity. Myoepithelial cell damage, abnormal lipid accumulation, reduced cell proliferation, increased apoptosis and inflammatory cell infiltration in the lacrimal gland were also seen. Hifα and NF-κB signaling pathways, moreover, were activated, while Pparα was downregulated, in the lacrimal glands of OSA mice. Fenofibrate treatment significantly alleviated pathological changes of the lacrimal gland induced by OSA. Conclusion: OSA disturbs the Hifα/Pparα/NF-κB signaling axis, which affects lacrimal gland structure and function and induces dry eye

Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

The effect of 0.02–0.37 strain on the precipitation law of O phase colonies in Ti2AlNb-based alloy during aging

O phase is the main strengthening phase of the lightweight high-temperature structural material—Ti2AlNb-based alloy, its morphology, size and distribution have significant impact on the mechanical properties of the alloy. This paper obtained different deformation areas with strains within the range of 0.02–0.37 in Ti2AlNb-based alloy sample through tensile deformation and precisely characterized strain values with DIC technique. The results indicate that while the strain was larger than 0.04, O phases would precipitate at the B2 grain boundary in the form of phase colony, whereas others precipitated in B2 grains appeared as fine granule. Phase colony structure, with its size reaching to dozens of micrometers, was composed of lamellar O phase. Within the strain range of 0.08–0.24, the precipitation amount of the O phase colonies was correlated linearly with strain level. It increased with the accumulating of strain. Within the strain range of 0.24–0.37, the amount of the O phase colonies no longer increased and stabilized at 15%. The mechanism of strain promoting precipitation of O phase colonies at the B2 grain boundary is shown as follow. Deformation made B2 matrix store a lot of geometrically necessary dislocations (GND), which led atoms in deformation area arrange in disorder and thus provided sufficient nucleate sites for O phase, promoting the concentrated nucleate of the O phase in this area and formed phase colony structure. The GND density at the B2 grain boundary was noticeable higher than that inside grain, thus O phase colonies primarily formed at grain boundary

A study of the sharp yield point of a Ti-22Al-25Nb alloy

Ti-22Al-25Nb alloy containing 0.2 wt. % hydrogen exhibits a sharp yield point on the stress-strain curve when it is tested above 960 °C. The main reason for this phenomenon can be attributed to the unidirectional crystal orientation and low level of lattice distortion above 960 °C, so that the dislocations tend to move in parallel directions with greater mobility and the stress can be rapidly released. Furthermore, strips of brittle α2 phase can cause stress concentration at the grain boundaries before plastic deformation occurs. Fracturing occurs at the strips of α2 phase when micro-deformation occurs, so that the accumulated stresses are rapidly released

Microstructure and High-Temperature Properties of TC31 Alloy Manufactured by Laser Melting Deposition

This paper presents a comprehensive study conducted to optimize the mechanical properties for a laser-melting-deposition fabricated TC31 (Ti-Al-Sn-Zr-Mo-Nb-W-Si) alloy, which is a newly developed high-temperature alloy used in the aerospace industry. The results showed that the laser melting deposition (LMD)-built sample exhibited columnar structures with very fine α-laths inside. Annealing and solution treatment resulted in an α+β lamellar structure consisting of α-laths and β-films, of which thicknesses depended on the temperature. Solution treatment and subsequent aging did not significantly change the lamellar structure. However, aging at 650 °C led to the formation of nanoscale α precipitates within the remaining β, while aging at 750 °C resulted in coarse α precipitates. The solution-treated samples exhibited the best combination of strength and ductility at room temperature, ultimate tensile strength of 1047 MPa, and elongation of 13.0%, which is superior to the wrought TC31 counterparts. The sample after solution treatment at 980 °C and subsequent aging at 650 °C obtained an attractive combination of strength and ductility both at room temperature and high temperature due to the synergistic effect of the soft α + β lamellar structure and hard fine α precipitates. These findings provide valuable information on developments of LMD-built TC31 alloy for aerospace applications and shed light on AM of other titanium alloys with desirable high-temperature properties

Microstructure and High-Temperature Properties of TC31 Alloy Manufactured by Laser Melting Deposition

This paper presents a comprehensive study conducted to optimize the mechanical properties for a laser-melting-deposition fabricated TC31 (Ti-Al-Sn-Zr-Mo-Nb-W-Si) alloy, which is a newly developed high-temperature alloy used in the aerospace industry. The results showed that the laser melting deposition (LMD)-built sample exhibited columnar structures with very fine α-laths inside. Annealing and solution treatment resulted in an α+β lamellar structure consisting of α-laths and β-films, of which thicknesses depended on the temperature. Solution treatment and subsequent aging did not significantly change the lamellar structure. However, aging at 650 °C led to the formation of nanoscale α precipitates within the remaining β, while aging at 750 °C resulted in coarse α precipitates. The solution-treated samples exhibited the best combination of strength and ductility at room temperature, ultimate tensile strength of 1047 MPa, and elongation of 13.0%, which is superior to the wrought TC31 counterparts. The sample after solution treatment at 980 °C and subsequent aging at 650 °C obtained an attractive combination of strength and ductility both at room temperature and high temperature due to the synergistic effect of the soft α + β lamellar structure and hard fine α precipitates. These findings provide valuable information on developments of LMD-built TC31 alloy for aerospace applications and shed light on AM of other titanium alloys with desirable high-temperature properties

Porous Framework Materials for Bioimaging and Cancer Therapy

Cancer remains one of the most pressing diseases in the world. Traditional treatments, including surgery, chemotherapy, and radiotherapy still show certain limitations. Recently, numerous cancer treatments have been proposed in combination with novel materials, such as photothermal therapy, chemodynamic therapy, immunotherapy, and a combination of therapeutic approaches. These new methods have shown significant advantages in reducing side effects and synergistically enhancing anti-cancer efficacy. In addition to the above approaches, early diagnosis and in situ monitoring of lesion areas are also important for reducing side effects and improving the success rate of cancer therapy. This depends on the decent use of bioimaging technology. In this review, we mainly summarize the recent advances in porous framework materials for bioimaging and cancer therapy. In addition, we present future challenges relating to bioimaging and cancer therapy based on porous framework materials

Porous Framework Materials for Bioimaging and Cancer Therapy

Cancer remains one of the most pressing diseases in the world. Traditional treatments, including surgery, chemotherapy, and radiotherapy still show certain limitations. Recently, numerous cancer treatments have been proposed in combination with novel materials, such as photothermal therapy, chemodynamic therapy, immunotherapy, and a combination of therapeutic approaches. These new methods have shown significant advantages in reducing side effects and synergistically enhancing anti-cancer efficacy. In addition to the above approaches, early diagnosis and in situ monitoring of lesion areas are also important for reducing side effects and improving the success rate of cancer therapy. This depends on the decent use of bioimaging technology. In this review, we mainly summarize the recent advances in porous framework materials for bioimaging and cancer therapy. In addition, we present future challenges relating to bioimaging and cancer therapy based on porous framework materials