Harbin Institute of Technology

About: Harbin Institute of Technology is a education organization based out in Harbin, China. It is known for research contribution in the topics: Microstructure & Control theory. The organization has 88259 authors who have published 109297 publications receiving 1603393 citations. The organization is also known as: HIT.

A swarm of slippery micropropellers penetrates the vitreous body of the eye

Abstract: The intravitreal delivery of therapeutic agents promises major benefits in the field of ocular medicine. Traditional delivery methods rely on the random, passive diffusion of molecules, which do not allow for the rapid delivery of a concentrated cargo to a defined region at the posterior pole of the eye. The use of particles promises targeted delivery but faces the challenge that most tissues including the vitreous have a tight macromolecular matrix that acts as a barrier and prevents its penetration. Here, we demonstrate novel intravitreal delivery microvehicles—slippery micropropellers—that can be actively propelled through the vitreous humor to reach the retina. The propulsion is achieved by helical magnetic micropropellers that have a liquid layer coating to minimize adhesion to the surrounding biopolymeric network. The submicrometer diameter of the propellers enables the penetration of the biopolymeric network and the propulsion through the porcine vitreous body of the eye over centimeter distances. Clinical optical coherence tomography is used to monitor the movement of the propellers and confirm their arrival on the retina near the optic disc. Overcoming the adhesion forces and actively navigating a swarm of micropropellers in the dense vitreous humor promise practical applications in ophthalmology.

A Novel Method.

Abstract: Parameter selection is one of the most important parts for nearly all the control strategies. Traditionally, controller parameters are chosen by utilizing trial and error, which is always tedious and time consuming. Moreover, such method is highly dependent on the experience of researchers, which means that it is hard to be popularized. In this light, this paper proposes a novel parameter searching approach by utilizing uniform design (UD) algorithm. By which the satisfactory controller parameters under a performance index could be selected. In this end, two simulation examples are conducted to verify the effectiveness of proposed scheme. Simulation results show that this novel approach, as compared to other intelligent tuning algorithms, excels in efficiency and time saving.

Enhanced catalytic degradation of methylene blue by α-Fe2O3/graphene oxide via heterogeneous photo-Fenton reactions

Abstract: Novel hybrid nanostructures or nanocomposites are receiving increasing attention due to their newly evolved properties. In this work, α-Fe 2 O 3 anchored to graphene oxide (GO) nanosheet (α-Fe 2 O 3 @GO) was synthesized through a facile hydrolysis process and its photo-catalytic performances and durability in heterogeneous Fenton system were fully evaluated. The decolorization rates of methylene blue in α-Fe 2 O 3 @GO + H 2 O 2 + UV system within a wide pH range were approximately 2.9-fold that of classical Degussa P25 TiO 2 + UV and 2.4-fold that of α-Fe 2 O 3 + H 2 O 2 + UV. This enhanced decolorization of methylene blue (MB) in α-Fe 2 O 3 @GO + H 2 O 2 + UV system were attributed to the unique incorporation of GO into the catalyst which not only mediated the morphology of active sites α-Fe 2 O 3 nanoparticles but also offered high electron conductivity and electrostatic attraction between negatively charged GO with positively charged MB. High efficiencies of degradation were achieved on various surface charged organic pollutants (around 96–100%), such as cationic compounds of MB and rhodamine B (RhB), anionic compound Orange II (OII) and Orange G (OG), neutral compounds of phenol, 2-nitrophenol (2-NP) and endocrine disrupting compound 17β-estradiol (E2). The dominant reactive oxygen species (ROS) responsible for decolorization, such as hydroxyl radicals ( OH) and superoxide anion radicals (O 2 − ) generated by activation of H 2 O 2 on the surface of α-Fe 2 O 3 @GO were detected and quantified by free radical quenching methods. The possible degradation mechanism of MB involved the rupture of phenothiazine ring by desulfurization and the rupture of phenyl ring due to the attack of ROS, which was analyzed by LC/MS/MS. The reduction of MB and its intermediates was consistent with the decreasing trend of the acute toxicity towards luminous bacteria with the increasing irradiation time. The results lay a foundation for highly effective and durable photo-Fenton technologies for organic wastewater within wider pH ranges than the conventional photo-Fenton reaction.