Dalian University of Technology

About: Dalian University of Technology is a education organization based out in Dalian, China. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 60890 authors who have published 71921 publications receiving 1188356 citations. The organization is also known as: Dàlián Lǐgōng Dàxué.

Microencapsulation of Bacteriophage Felix O1 into Chitosan-Alginate Microspheres for Oral Delivery

Abstract: This paper reports the development of microencapsulated bacteriophage Felix O1 for oral delivery using a chitosan-alginate-CaCl2 system. In vitro studies were used to determine the effects of simulated gastric fluid (SGF) and bile salts on the viability of free and encapsulated phage. Free phage Felix O1 was found to be extremely sensitive to acidic environments and was not detectable after a 5-min exposure to pHs below 3.7. In contrast, the number of microencapsulated phage decreased by 0.67 log units only, even at pH 2.4, for the same period of incubation. The viable count of microencapsulated phage decreased only 2.58 log units during a 1-h exposure to SGF with pepsin at pH 2.4. After 3 h of incubation in 1 and 2% bile solutions, the free phage count decreased by 1.29 and 1.67 log units, respectively, while the viability of encapsulated phage was fully maintained. Encapsulated phage was completely released from the microspheres upon exposure to simulated intestinal fluid (pH 6.8) within 6 h. The encapsulated phage in wet microspheres retained full viability when stored at 4°C for the duration of the testing period (6 weeks). With the use of trehalose as a stabilizing agent, the microencapsulated phage in dried form had a 12.6% survival rate after storage for 6 weeks. The current encapsulation technique enables a large proportion of bacteriophage Felix O1 to remain bioactive in a simulated gastrointestinal tract environment, which indicates that these microspheres may facilitate delivery of therapeutic phage to the gut.

A Color‐Tunable Europium Complex Emitting Three Primary Colors and White Light

Abstract: The manufacture of new full-color displays is one of the main tasks in flat-panel display systems and lighting technology. Different applications place different demands on emitted light: in some cases a white-light source is needed, and in others pure colors are necessary. Thus, white emission should ideally be composed of three (blue, green, and red) or two (blue and yellow) primary colors and cover the whole visible range from 400 to 700 nm, and the emitter should have the ability to emit the primary colors simultaneously with equal intensities to produce white light and the pure colors separately in a tunable way. Considerable interest exists for such color-tunable materials, which can be used to define or modify environments, moods, and brands. Traditional methods of such white light generation typically rely on mixing various primary colors from different emitting materials. An alternative approach for the generation of efficient (white) light sources is to use a single-component emitter, which can have advantages such as greater stability, better reproducibility, no phase separation, and simpler fabrication processes. 8] Although a few materials show white-light emission as a single-emitting component, none has been reported to produce well-separated blue, green, and red emissions beside white light. Since energy transfer typically quenches one or more of the emission pathways and thereby restricts the transitions that define the output spectrum, the design of color tunable single-component emitters requires readily tailorable different fluorophores and fine-tuning of the energy-transfer processes between the different fluorophores. On the other hand, lanthanide-containing materials, which exhibit excellent sharp-emission luminescence properties with suitable sensitization, have attracted considerable interest and been effectively used in designing white-emitting nanoparticles. With judiciously chosen red(Eu, Pr, Sm), green(Tb, Er), and blue-emissive (Tm , Ce, Dy) ions doped in an suitable host, it is possible to obtain phosphors which emit across the entire visible spectrum with high color purity. Specifically, an Eu-containing singlecomponent complex has been reported to offer white-light emission in a carefully designed system which only allows partial energy transfer between the sensitizing fluorophore and the Eu center. Herein we report the design and synthesis of a new fluorophore that exhibits tunable emission of three primary colors (blue, green, and red) and white light, by combining an Eu moiety as the origin of red light with an organic ligand that comprises a blue-emitting coumarin fluorophore and a green-emitting Rhodamine 6G fluorophore. Coumarin-Rhodamine CR1 was synthesized by reaction of 7-diethylamino-2-oxo-2H-chromen-3-carboxylic chloride and N-(Rhodamine-6G)lactamethylenediamine and recrystallized from ethanol as yellow crystals. Single-crystal X-ray structural analysis confirms the coexistence of two fluorophores in CR1 (Supporting Information Figure S1), whereby the Rhodamine 6G moiety is in a luminescence-inactive ringclosed tautomeric form. Europium compound CR1-Eu (1) was prepared by refluxing ligand CR1 and [Eu(tta)3] in THF (tta = 1,1,1-trifluoro-3-(2-thenoyl)acetone) and purified by recrystallization as an amorphous yellow powder. Elemental analysis and H NMR spectroscopic characterization suggest the chemical formula [Eu(tta)2(CR1)2](tta) for 1 (Figure 1).

Metal–organic frameworks and their derivatives as electrocatalysts for the oxygen evolution reaction

Abstract: Electrochemical water splitting is an appealing and promising approach for energy conversion and storage. As a key half-reaction of electricity-driven water splitting, the oxygen evolution reaction (OER) is a sluggish process due to the transfer of four protons and four electrons. Therefore, development of low-cost and robust OER electrocatalysts is of great importance for improving the efficiency of water splitting. Based on the merits of high surface area, rich pore structure, diverse composition and well-defined metal centers, metal-organic frameworks (MOFs) and their derivatives have been widely exploited as OER electrocatalysts. Herein, the current progress on MOFs and their derivatives for OER electrolysis is summarized, highlighting the design principle, synthetic methods and performance for MOF-based materials. In addition, the structure-performance relationships of MOFs and their derivatives toward the OER are discussed, providing valuable insights into rationally developing OER catalysts with high efficiency. The current scientific and technological challenges and future perspectives towards the purpose of sustainable industrial applications are addressed at the end.