In recent years, tremendous progress has been made in the development of rare-earth ion doped tellurite glass laser sources, ranging from watt and multiwatt level fiber lasers to nanowatt level microsphere lasers. Significant success has been achieved in extending the spectral range of tellurite fiber lasers generating at wavelengths beyond 2 μm as well as in theoretical understanding. This review is aimed at discussing the state of the art of neodymium-, erbium-, thulium-, and holmium-doped tellurite glass fiber and microsphere lasers.

In recent years, compound glass microsphere resonator devices have attracted increasing interest and have been widely used in sensing, microsphere lasers, and nonlinear optics. Compared with traditional silica resonators, compound glass microsphere resonators have many significant and attractive properties, such as high-Q factor, an ability to achieve high rare earth ion, wide infrared transmittance and low phonon energy. This review provides a summary and a critical assessment of the fabrication and the optical characterization of compound glasses and the related fabrication and applications of compound glass microsphere resonators.

The restriction of normal blood flow is the cause of many diseases including stroke and coronary artery diseases. To study the consequences of vessel blockade, previous models mainly focused on major arteries and have been well studied. However, the sequela from interruption of capillary vessels by microemboli was less well characterized. In this study, we exploited polystyrene microspheres as a mimicry of microemboli and found that microspheres of this size can be trapped in capillary vessels of all organs without causing apparent acute morbidities of the host. Interestingly, we accidentally found significantly increased recruitment of monocyte to the brain vasculature expressing low levels of Ly6C expression, but not to other organs. Further study revealed the spleen is the major origin of the recruited monocyte. Most importantly, VCAM-1 which is constitutively expressed on mouse brain vasculature orchestrates the recruitment of monocyte. Blockade of VCAM-1 in mice can substantially reduce monocyte recruitment. Interestingly, monocytes get activated through TNF- signaling which likely happens in the spleen instead of the brain. Collectively, we found a unique monocyte recruitment strategy in the brain comparing to other orangs, in response to capillary blockade induced by polystyrene microspheres.

Imperatorin is a chemical compound belong to Linear furan coumarins. Imperatorin is attracting considerable attention because of its anti-tumor, antibacterial, anti-inflammatory, anticoagulant and inhibition of myocardial hypetrophy and other pharmacological efficacy. However, imperatorin has limited water solubility and preferable lipid solubility, we decided to design and synthesize imperatorin lipid microsphere, to optimize preparation conditions. The aim was to develop and formulate imperatorin lipid microsphere through nano emulsion technology and apply the response surface-central composite design to optimize the imperatorin lipid microsphere formulation. Influence of content of amount of egg lecithin(A), amount of poloxamer188(B), soybean oil for injection accounted for the total percentage of oil phase(C) were investigated. Integrated effect of dependent variables including particle size(Y₁), polydispersity index(Y₂), Zeta potentials(Y₃), drug loading(Y₄), encapsulation efficiency(Y₅). Data of overall desirabiities were fitted to a second-order polynomial equation, through which three dimensional response surface graphs were described. Optimum experimental conditions were calculated by Design-Expert 8.06. Results indicated that the optimum preparation conditions were as follows: egg lecithin amount 1.39 g, poloxamer188 amount 0.21 g, soybean oil for injection amount 10.57%. Preparation of imperatorin lipid microsphere according to the optimum experimental conditions resulted in an overall desirability of 0.7286, while the particele size (168±0.54) nm, polydispersity index (PDI) (0.138±0.02), Zeta potentials (−43.5±0.5) mV, drug loading (0.833±0.27) mg·mL⁻¹, encapsulation efficiency (90±1.27)%. The difference between observed and predicted values of the overall desirability of the optimum formulation was in range from 2.4% to 4.3%. Subsequently, using the Scanning electron microscopy to observe the micromorphology of imperatorin lipid microsphere, the result shows that round globular of relatively uniform and sizes within 200nm.The proliferation study of imperatorin lipid microsphere on MDA-MB-231 was investigated by MTT method. Furthermore, pharmacokinetics in Sprague Dawley rats were evaluated using orbital bleeding. A sensitive and reliable liquid chromatography with High Performance Liquid Chromatography (HPLC) method was established and validated for the quantification of imperatorin in rat plasma samples. The data were calculated by DAS (Drug and statistics) pharmacokinetic software version3.2.6 (China). Results demonstrated that imperatorin lipid microsphere can significantly enhance the bioavailability of imperatorin and can significantly inhibit MDA-MB-231 cell proliferating. In conclusion, our results suggersted that the response surface-central composite design is suitable for the optimized lipid microspere formulation. Imperatorin Lipid microsphere can improve the bioavailability of imperatorin and inhibit the proliferation of MDA-MB-231 than that of imperatorin.

The objective of this study aimed to develop biodegradable calcium alginate microspheres carrying doxorubicin (Dox) at the micrometer-scale for sustained-release and the capacity of pH regulatory for transarterial chemoembolization. Ultrasonic atomization and CaCl2 cross-linking technologies were used to prepare the microspheres. A 4 by 5 experiment was first designed to identify imperative parameters. The concentration of CaCl2 and the flow rate of the pump were found to be critical to generate microspheres with a constant volume median diameter (~ 39 m) across 5 groups with different alginate:NaHCO3 ratios using each corresponding flow rate. In each group, the encapsulation efficiency was positively correlated to the Dox-loaded efficiency. Fourier-transform infrared spectroscopy showed that NaHCO3 and Dox were step-by-step incorporated into the calcium alginate microspheres successfully. Microspheres containing alginate:NaHCO3 = 1 exhibited rough and porous surfaces, high Young’s modulus and hardness. In each group with the same alginate:NaHCO3 ratio, the swelling rates of microspheres were higher in PBS containing 10% FBS compared to those in PBS alone. Microspheres with relative high NaHCO3 concentrations in PBS containing 10% FBS maintained better physiological pH and higher accumulated Dox release ratios. In two distinct hepatocellular carcinoma-derived cell lines, treatments with microspheres carrying Dox demonstrated that the cell viabilities decreased in groups with relative high NaHCO3 ratios in time- and dose-dependent manners. Our results suggested that biodegradable alginate microspheres containing relative high NaHCO3 concentrations improved the cytotoxicity effects in vitro.

In order to study the hydrothermal behavior of cotton fiber, the carbonization process and structural evolution of discarded cotton fiber (WCF) under hydrothermal conditions were discussed use microcrystalline cellulose (MCC) and glucose as model compounds. The results showed that high temperature was beneficial to the hydrolysis of discarded cotton fiber, and the yield of the sugar was 4.5% which was lower than that of MCC 6.51%. WFC and MCC are carbonized in 240~260 ℃ and 220~240 ℃ respectively, while the carbonation temperature of glucose is lower than 220 ℃. The quality ratio of C/O in WCF and glucose hydrothermal products is 5.79 and 5.85 respectively; three kinds of hydrothermal carbonization products have similar crystal structure and oxygen-containing functional groups, and the WCF carbonization products contain a lot of irregular particles while the main products of glucose carbonization are 0.5 μm carbon microspheres (CMCC). The results show that glucose is an important intermediate product of WCF hydrolysis carbonation, and there are two main paths of cotton fiber hydrothermal carbonization: some cotton fibers are completely hydrolyzed into glucose and the nucleation is formed, and then the carbon microspheres are grown; for the other part, the glucose ring of the polysaccharide oligosaccharide formed by the incomplete hydrolysis of cotton fiber in the hydrothermal environment of high temperature and pressure breaks, then forms the particulate matters.

We propose the physical proof-of-concept of a new simple miniature pressure sensor based on the whispering gallery modes (WGMs) optically excited in a dielectric microsphere placed near a flexible reflective membrane, which acts as an ambient pressure sensing element. WGMs excitation is carried out by free-space coupling of optical radiation to a microsphere. The distinctive feature of proposed sensor design is double excitation of optical eigenmodes by forward and backward propagating radiation reflected from a membrane that causes WGMs interference in particle volume. The optical intensity of resulting resonant field established in the microsphere carries information about the exact position of the pressure-loaded reflecting membrane. The sensitivity of the proposed sensor strongly depends on the quality factor of the excited resonant mode, as well as geometrical and mechanical parameters of the flexible membrane. We propose to register not the displacement of the position of the WGM resonance, but the change in its amplitude under the influence of the change in the distance between the sphere and the mirror under the influence of pressure. Important advantages of the proposed sensor are miniature design (linear sensor dimensions depends only on the membrane diameter) and the absence of a mechanical contact of pressure-sensitive element with WGM resonator.

Rapid haemostasis during surgery is essential when one wants to reduce the duration of opera-tions, reduce the need for transfusions, and above all when one wants to achieve better patient management. The use of haemostatic agents, sealants and adhesives improves the haemostatic process by offering several advantages, especially in vascular surgery. These agents vary widely in their mechanism of action, composition, ease of application, adhesion to wet or dry tissue, im-munogenicity and cost. The most used are cyanoacrylate-based glues (Glubran 2) or polysaccharide hydrogel-microsphere powder (AristaTMAH). This work is based on a retrospective study carried out on a sample of patients with different vascular diseases (FAV, pseudoaneurysm and PICC application) in which two different haemostatic sealants were used. The aim was to assess the safety, the advantages and the ability of both sealants to activate the haemostatic process at the affected site, also in relation to their chemical-physical characteristics. The obtained results showed that the application of Glubran 2 and AristaTMAH as surgical wound closure systems is effective and safe as the success achieved was ≥94% on anastomoses of FAV; 100% on stabilization of Picc catheters; ≤95% on pseudoaneurysms.

Tissue engineering is an emerging field of research due to its growing impact on the regeneration of tissue injured from damage and organ failure. Small hydrogel microspheres containing regenerative cells and stimulators can be used as building blocks to regenerate tissue by injecting them into damaged areas; a microneedle is used to minimize the incision and any associated infections. To address the need for production of a large number of microspheres for use in tissue engineering, we developed a 3D coaxial multi-nozzle flow-focusing device fabricated via a simple 3D-printing method that demonstrates a high rate of microsphere production per nozzle. This device has six coaxial microscale nozzles that produce hydrogel microspheres. Two individual parts—the inlet and nozzle—can be made separately by a 3D printer and bonded together using uncured photo-curable resin as glue. The dimensions of the microspheres are between 100 μm and 1200 μm. They are produced by adjusting the flow rate ratio between the dispersed and continuous media. A flow rate ratio of 180 demonstrated the highest microsphere production rate of 2.12e+5 microspheres per sec (0.25 mL/min). This microsphere production rate per nozzle is four times higher than that of currently available devices.

This study presents of the microsphere-based fiber-optic sensor with the ZnO ALD coating thickness of 100 nm and 200 nm for temperature measurements. Metrological properties of the sensor were investigated over the temperature range of 100°C to 300°C, with a 10°C step. The interferometric signal is used to control whether the microstructure is intact. Spectrum shift of a reflected signal is used to conclude changes in measured parameter for the sensor with a 100 nm coating, while the reflected signal intensity is an indicator during measurements executed by a sensor with a 200 nm coating. With changing temperature, the peak position or intensity of a reflected signal also changes. The R2 coefficient of the presented sensors indicates a linear fit of over 0.99 to the obtained data. The sensitivity of the sensors, investigated in this study, equals 103.5 nW/°C and 0.019 nm/°C for ZnO thickness of 200 nm and 100 nm, respectively.

Single-particle inductively coupled plasma mass spectrometry (spICP-MS) has been used for particle size measurement of diverse types of individual nanoparticles and micrometer-sized carbon-based particles, such as microplastics. However, its applicability to the measurement of micrometer-sized non-carbon-based particles such as silica (SiO2) is unclear. In this study, the applicability of spICP-MS to particle size measurement of non-porous/mesoporous SiO2 micro-spheres with a nominal diameter of 5.0 µm or smaller was investigated. Particle sizes of these microspheres were measured using both spICP-MS based on a conventional calibration approach using an ion standard solution and scanning electron microscopy (SEM) as a reference technique and the results were compared. The particle size distributions obtained using both techniques were in agreement within analytical uncertainty. The applicability of this technique to the detection of metal-containing protein-binding mesoporous SiO2 microspheres was also investigated. Bound iron (Fe)-containing proteins (i.e., lactoferrin and transferrin) of mesoporous SiO2 microspheres were detected using Fe as a presence marker for the proteins. Thus, spICP-MS is applicable to the particle size measurement of large-sized and non-porous/mesoporous SiO2 microspheres; it has considerable potential for element-based detection and qualification of bound proteins of mes-oporous SiO2 microspheres in a variety of applications.

One of the problems, which make it difficult to solve the mystery of the origin of life, would be how life emerged in chemically complex messy environments on the primitive Earth. It is considered that three main points contributed to open the way to the emergence of life. (1) A characteristic inherent in [GADV]-amino acids, which are easily produced with prebiotic means. (2) Protein 0th-order structure or [GADV]-amino acid composition generating water-soluble globular protein with some flexibility, which can be produced even by random joining of [GADV]-amino acids. (3) Formation of versatile [GADV]-microspheres, which can grow, divide, proliferate even without genetic system, was the emergence of proto-life. (4) [GADV]-microspheres with a higher proliferation ability than others could be selected. The proto-Dawin evolution made it possible to proceed forward to creation of the core life system composed of (GNC)n gene, anticodon stem-loop tRNA or AntiC-SL tRNA (GNC genetic code) and [GADV]-protein. (5) Eventually, the first genuine life with the core life system emerged. Thus, the formation processes of [GADV]-protein and (GNC)n gene in chemically complex messy environments were the steps to the emergence of genuine life.