Rational design of agarose/dextran composite microspheres with tunable core-shell microstructures for chromatographic application.

A new type of core-shell microsphere was prepared by a pre-crosslinking method, consisting of cross-linked agarose microspheres as the core and agarose-dextran as the shell. After optimizing the preparation process, the microspheres with a uniform particle size were obtained and characterized using cryo-scanning electron microscopy to determine their surface and cross-sectional morphology. Results from flow rate-pressure and chromatographic performance tests showed that the core-shell agarose microspheres were supported by the core microspheres and composed of composite polysaccharides, forming an interpenetrating polymer network structure as a hard shell. The core-shell agarose microspheres showed a 300.5 % increase in linear flow rate compared to composite polysaccharide microspheres prepared from shell materials and a 141.5 % increase compared to 6 % agarose microspheres. Additionally, the large pore structure of the shell combined with the fine pore structure of the core improved the material separation efficiency in the range of 0.1-2000 kDa. These findings suggest that core-shell natural polysaccharide microspheres have great potential as a separation chromatographic medium.

Bio-based active packaging: Gallic acid modified agarose coatings in grass carp (Ctenopharyngodon idellus) preservation.

Antioxidant and antimicrobial agarose coatings were developed by grafting gallic acid through the carbodiimide coupling method. Structural characterization revealed that the carboxyl group of gallic acid was successfully grafted onto the C6-OH of D-galactose in agarose, with the highest observed grafting ratio being 13.73 %. The grafting of gallic acid significantly increased the antioxidant and bacteriostatic activities of the agarose. As the grafting ratio of gallic acid-modified agarose (GaAg) increased from 0 to 13.73 %, the scavenging ratio of DPPH and the inhibition ratio of ß-carotene bleaching were observed to increase from 0 % to 65.92 % and 6.89 % to 73.46 %, respectively. GaAg exhibited up to 100 % inhibition of Escherichia coli and Staphylococcus aureus. The physicochemical properties of gel strength, viscosity, gelling temperature and melting temperature decreased to 971.3 g/cm2, 17.9 mPa·s, 31.7 °C and 84.1 °C, respectively. The gel contact angle was increased from 22.1° to 73.6°. Fish preservation tests have demonstrated that it effectively inhibited bacterial growth, prevented fat oxidation, blocked light, reduced moisture loss, and enhanced the overall quality of grass carp (Ctenopharyngodon idellus) fillets during refrigeration, which was more effective than native agarose in extending the shelf life of fish. Therefore, GaAg holds promise as an aquatic product preservative.

Sensitive and Specific Detection of Carcinoembryonic Antigens Using Toroidal Metamaterial Biosensors Integrated with Functionalized Gold Nanoparticles.

Carcinoembryonic antigen (CEA) is a biomarker that is highly expressed in cancer patients. Label-free, highly sensitive, and specific detection of CEA biomarkers can therefore greatly aid in the early detection and screening of cancer. This study presents a toroidal metamaterial biosensor integrated with functionalized gold nanoparticles (AuNPs) that demonstrated highly sensitive and specific detection of CEA using terahertz (THz) time-domain spectroscopy. In the biosensor, a closed-loop magnetic field formed an electrical confinement, resulting in a high sensitivity (287.8 GHz/RIU) and an ultrahigh quality factor (15.04). In addition, the integrated AuNPs with high refractive indices significantly enhanced the sensing performance of the biosensor. To explore the quantitative and qualitative detection of CEA, CEA biomarkers with various concentrations and four types of proteins were measured by the designed biosensor, achieving a limit of detection of 0.17 ng and high specificity. Even more significant, the proposed AuNP-integrated THz toroidal metamaterial biosensor demonstrates exceptional potential for use in technologies for cancer diagnosis and monitoring.

Superhydrophilic Wrinkle-Free Cotton Fabrics via Plasma and Nanofluid Treatment.

We demonstrate in this study a wrinkle-free, superhydrophilic cotton fabric (contact angle ∼0°) by uniformly attaching specially engineered nanoparticles to plasma-pretreated cotton fabric. Because of their highly charged nature, the nanoparticles are firmly anchored on the fabric via electrostatic interactions, as confirmed by microscopy and chemical analyses. The durability of wetting behavior and wrinkle-free property of the nanoparticle-coated fabrics were evaluated via aging, laundering, and abrasion tests. The strongly attached coatings are stable enough to maintain their superhydrophilic nature even after 60 days of aging at room temperature, 50 laundering cycles, and 25 000 abrasion cycles. Moreover, the nanoparticle-coated superhydrophilic fabrics exhibit great wrinkle-recovery property, tensile strength, and abrasion resistance performance up to 25 000 abrasion cycles.

[An introduction to the transmission of modern western medicine in southwestern borderland].

Yunnan is located in the southwestern border of China, neighboring South Asia and Southeast Asia. Since the end ofthe 19th century, the western medicine was introduced into Yunnan Province along with the arrival of missionaries, exerting great influence on local medicine in Yunnan, even in inland China, and has become an integral part of Chinese modern medical history. Initially, the missionaries who knew only a little medical knowledge and treated the patients effectively during their missionary work with the western medicines they carried, so as to develop the believers. At the beginning of the 20th century, Catholic Church and Christian Church began to establish Church Hospitals in Yunnan, including the "Dafashi Hospital (French Consulate Hospital)" set up in 1901, and "Fudian Hospital (French Government Hospital)" established in 1902, and many Hospitals set up in Yunnan Province. The Church Hospitals also established medical schools and nurse schools all over Yunnan, which promoted modern medical education in Yunnan, and had profound influence on modern education of western medicine in this Provence.

Sponges with covalently tethered amines for high-efficiency carbon capture.

Adsorption using solid amine sorbents is an attractive emerging technology for energy-efficient carbon capture. Current syntheses for solid amine sorbents mainly based on physical impregnation or grafting-to methods (for example, aminosilane-grafting) lead to limited sorbent performance in terms of stability and working capacity, respectively. Here we report a family of solid amine sorbents using a grafting-from synthesis approach and synthesized by cationic polymerization of oxazolines on mesoporous silica. The sorbent with high amount of covalently tethered amines shows fast adsorption rate, high amine efficiency and sorbent capacity well exceeding the highest value reported to date for low-temperature carbon dioxide sorbents under simulated flue gas conditions. The demonstrated efficiency of the new amine-immobilization chemistry may open up new avenues in the development of advanced carbon dioxide sorbents, as well as other nitrogen-functionalized systems.

Magnetostrictive particle based biosensors for in situ and real-time detection of pathogens in water.

Biosensors for in situ detection of pathogenic bacteria in liquid are developed using magnetostrictive particles (MSP) as the sensor platform. The sensing elements used are phage E2 against Salmonella typhimurium, monoclonal antibody against Listeria monocytogenes, polyclonal antibody against Escherichia coli, and polyclonal antibody against Staphylococcus aureus, respectively. These biosensors were characterized in cultures with different populations ranging from 5 × 10(1) to 5 × 10(8) cfu/mL. It is found that the MSP-based biosensors work well in water and have a rapid response with a response time in minutes, which makes the MSP-based sensors suitable for in situ and real-time detection of pathogenic bacteria in liquid. The experimental results show that all MSP-phage and MSP-antibody biosensors in size of 1.0 mm × 0.3 mm × 15 µm exhibit a detection limit better than 100 cfu/mL. Based on the Hill plot, it is concluded that each bacterial cell is bound onto the sensor surface through about four-to-five sites. When the cultures with low population (<10(6) cfu/mL) are tested, both MSP-phage and MSP-antibody sensors exhibit the similar response. However, the phage-MSP sensors exhibit a higher capability in the capture of target bacterial cell.

Synthesis and carbon dioxide sorption of layered double hydroxide/silica foam nanocomposites with hierarchical mesostructure.

Layered double hydroxides (LDHs) with a hierarchical mesostructure are successfully synthesized on mesoporous silica foams by simple impregnation and hydrothermal treatment. The as-synthesized LDH/silica foam nanocomposites show well-defined mesostructures with high surface areas, large pore volumes, and mesopores of 6-7 nm. The nanocomposites act as carbon dioxide (CO2 ) sorbents under simulated flue gas conditions. They also exhibit significantly enhanced CO2 capacities under high-pressure conditions and high CO2 /N2 and CO2 /CH4 selectivities.

Facile synthesis and application of a carbon foam with large mesopores.

By combining elements of hard- and soft-templating, a facile synthesis method for carbon foams with large mesopores has been demonstrated. A commercial Pluronic surfactant was used as the structure-directing agent as well as the carbon precursor. No micelle swelling agent or post treatment is necessary to enlarge mesopores. As such this method requires fewer synthesis steps and is highly scalable. The as-synthesized meso-carbons showed potential applications in the fields of carbon oxide capture and lithium-sulfur batteries.

Successful implementation of the stepwise layer-by-layer growth of MOF thin films on confined surfaces: mesoporous silica foam as a first case study.

Here we report the successful growth of highly crystalline homogeneous MOF thin films of HKUST-1 and ZIF-8 on mesoporous silica foam, by employing a layer-by-layer (LBL) method. The ability to control and direct the growth of MOF thin films on confined surfaces, using the stepwise LBL method, paves the way for new prospective applications of such hybrid systems.

Magnetostrictive Microcantilever as an Advanced Transducer for Biosensors.

The magnetostrictive microcantilever (MSMC) as a high-performance transducer was introduced for the development of biosensors. The principle and characterization of MSMC are presented. The MSMC is wireless and can be easily actuated and sensed using magnetic field/signal. More importantly, the MSMC exhibits a high Q value and works well in liquid. The resonance behavior of MSMC is characterized in air at different pressures and in different liquids, respectively. It is found that the Q value of the MSMC in water reaches about 40. Although the density and viscosity of the surrounding media affect the resonance frequency and the Q value of MSMC, the density has a stronger influence on the resonance frequency and the viscosity has a stronger influence on the Q value, which result in that, for MSMC in air at pressure of less than 100 Pa, the resonance frequency of MSMC is almost independent of the pressure, while the Q value increases with decreasing pressure. MSMC array was developed and characterized. It is experimentally demonstrated that the characterization of an MSMC array is as simple as the characterization of a single MSMC. A filamentous phage against Salmonella typhimurium was utilized as bio-recognition unit to develop an MSMC based biosensor. The detection of S. typhimurium in water demonstrated that the MSMC works well in liquid.