Three-dimensional printing-based electro-millifluidic devices for fabricating multi-compartment particles

In this work, we demonstrate the use of stereolithographic 3D printing to fabricate millifluidic devices, which are used to engineer particles with multiple compartments. As the 3D design is directly transferred to the actual prototype, this method accommodates 3D millimeter-scaled features that are difficult to achieve by either lithographic-based microfabrication or traditional macrofabrication techniques. We exploit this approach to produce millifluidic networks to deliver multiple fluidic components. By taking advantage of the laminar flow, the fluidic components can form liquid jets with distinct patterns, and each pattern has clear boundaries between the liquid phases. Afterwards, droplets with controlled size are fabricated by spraying the liquid jet in an electric field, and subsequently converted to particles after a solidification step. As a demonstration, we fabricate calcium alginate particles with structures of (1) slice-by-slice multiple lamellae, (2) concentric core-shells, and (3) petals surrounding the particle centers. Furthermore, distinct hybrid particles combining two or more of the above structures are also obtained. These compartmentalized particles impart spatially dependent functionalities and properties. To show their applicability, various ingredients, including fruit juices, drugs, and magnetic nanoparticles are encapsulated in the different compartments as proof-of-concepts for applications, including food, drug delivery, and bioassays. Our 3D printed electro-millifluidic approach represents a convenient and robust method to extend the range of structures of functional particles.published_or_final_versio

A possible mechanism to tune magneto-electroluminescence in organic light-emitting diodes through adjusting the triplet exciton density

At 15 K, the high field decay of magneto-electroluminescence (MEL) in tris (8-hydroxyquinoine) aluminum (Alq 3)-based organic light-emitting diodes is greatly suppressed by mixing hole transport material N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl) benzidine (NPB) into Alq 3 emission layer. The positive correlation between the MEL decay and the triplet exciton density indicates the reduced triplet exciton density is the major contributing factor. The change of triplet exciton density and then the MEL upon NPB mixing may result from the strengths change of charge-triplets interaction, in which the injected charges flowing through the exciton formation zone without forming static space charges play the most important role. © 2011 American Institute of Physics.published_or_final_versio

Ethnic differences in susceptibilities to A(H1N1) flu: An epidemic parameter indicating a weak viral virulence

The current A(H1N1) flu has showed sub-population dependent susceptibility and fatality as early as April and May of 2009 in its first wave of spreading. After the pandemic outbreak spreads globally for more than seven months, the subpopulation dependence of this flu, including ethnicity, age and genderselectivity, has been recognized by several research groups. This paper attempts to discussed how to identify ethnic selectivity from the released data by WHO relevant to this ongoing flu, review some recently published papers describing the presence of ethnic differences in susceptibilities to the H1N1flu virus and further raised an argument that ethnic differences in  susceptibilities to a virus might be a piece of evidence reflecting a weak virulence of that specific virus

The expression patterns of nogo-A, myelin associated glycoprotein and oligodendrocyte myelin glycoprotein in the retina after ocular hypertension : the expression of myelin proteins in the retina in glaucoma

Nogo-A, a major myelin inhibitory protein, inhibits axon growth and synaptic function in the central nervous system. Glaucoma is a progressive neuropathy as a result of retinal ganglion cell (RGC) death. Synaptic degeneration is thought to be an early pathology of neurodegeneration in glaucoma and precedes RGC loss. Here experimental ocular hypertension model was induced in adult rats with laser coagulation of the episcleral and limbal veins. The expression of Nogo-A, myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp) in the retina was investigated using immunohistochemistry and Western blotting. We found that Nogo-A was expressed in the RGCs and upregulated after the induction of ocular hypertension. OMgp was only expressed in the inner plexiform layer. There was no MAG expression in the retina. Our data provided, for the first time, the expression patterns of three myelin proteins in the adult retina and suggested an important role of Nogo-A in the RGC death and synaptic degeneration in glaucoma. © 2011 Springer Science+Business Media, LLC.postprin

Biological impacts of 'hot-spot' mutations of hepatitis B virus X proteins are genotype B and C differentiated

AIM: To investigate the biological impacts of “hot-spot” mutations on genotype B and C HBV X proteins (HBx). METHODS: Five types of “hot-spot” mutations of genotype B or C HBV X genes, which sequentially lead to the amino acid substitutions of HBx as I127T, F132Y, K130M+V131I, I127T+K130M+V131I, or K130M+V131I+F132Y, respectively, were generated by means of site-directed mutagenesis. To evaluate the anti-proliferative effects, HBx or related mutants’ expression vectors were transfected separately to the Chang cells by lipofectamine, and the cells were cultured in hygromycin selective medium for 14 d, drug-resistant colonies were fixed with cold methanol, stained with Giemsa dyes and scored (increase of the colonies indicated the reduction of the anti-proliferation activity, and vice versa). Different types of HBx expression vectors were co-transfected separately with the reporter plasmid pCMVβ to Chang cells, which were lysed 48 h post-transfection and the intra-cellular β-galactosidase activities were monitored (increase of the β-galactosidase activities indicated the reduction of the transactivation activity, and vice versa). All data obtained were calculated by paired-samples t-test. RESULTS: As compared to standard genotype B HBx, mutants of I127T and I127T+K130M+V131I showed higher transactivation and anti-proliferative activities, while the mutants of F132Y, K130M+V131I, and K130M+V131I+F132Y showed lower activities. As compared to standard genotype C HBx, I127T mutant showed higher transactivation activity, while the other four types of mutants showed no differences. With regard to anti-proliferative activity, compared to standard genotype C HBx, F132Y and K130M+V131I mutants showed lower activities, and K130M+V131I +F132Y mutant, on the other hand, showed higher activity, while the mutants of I127T and I127T+K130M+V131I showed no differences. CONCLUSION: “Hot-spot” mutations affect the anti-proliferation and transactivation activities of genotype B and/or C HBx, and the biological impacts of most “hot-spot” mutations on HBx are genotype B and C differentiated.published_or_final_versio

Local Stabilization for Multiple Input-Delay Systems subject to Saturating Actuators: The Continuous-time Case

National Natural Science Foundation of China under Grants 61773156, 61873148, and 61933007; Natural Science Foundation of Henan Province of China under Grant 202300410159; Program for Science and Technology Innovation Talents in the Universities of Henan Province of China under Grant 19HASTIT028; Royal Society of the U.K.; Alexander von Humboldt Foundation of Germany

Synchronization Control for Discrete-Time-Delayed Dynamical Networks with Switching Topology under Actuator Saturations

10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 61773156, 61873148, 61673141 and 61933007); 10.13039/501100018551-Program for Science and Technology Innovation Talents in the Universities of Henan Province of China (Grant Number: 19HASTIT028); 10.13039/501100010029-Research Fund for the Taishan Scholar Project of Shandong Province of China; 10.13039/501100000288-Royal Society of the U.K.; 10.13039/100005156-Alexander von Humboldt Foundation of Germany

Au/n-ZnO rectifying contact fabricated with hydrogen peroxide pretreatment

Au contacts were deposited on n -type ZnO single crystals with and without hydrogen peroxide pretreatment for the ZnO substrate. The Au/ZnO contacts fabricated on substrates without H2 O2 pretreatment were Ohmic and those with H2 O2 pretreatment were rectifying. With an aim of fabricating a good quality Schottky contact, the rectifying property of the Au/ZnO contact was systemically investigated by varying the treatment temperature and duration. The best performing Schottky contact was found to have an ideality factor of 1.15 and a leakage current of ∼ 10-7 A cm-2. A multispectroscopic study, including scanning electron microscopy, positron annihilation spectroscopy, deep level transient spectroscopy, x-ray photoelectron spectroscopy, and photoluminescence, showed that the H2 O2 treatment removed the OH impurity and created Zn-vacancy related defects hence decreasing the conductivity of the ZnO surface layer, a condition favorable for forming good Schottky contact. However, the H2 O2 treatment also resulted in a deterioration of the surface morphology, leading to an increase in the Schottky contact ideality factor and leakage current in the case of nonoptimal treatment time and temperature. © 2008 American Institute of Physics.published_or_final_versio

Hydrogen peroxide treatment induced rectifying behavior of Aun-ZnO contact

Conversion of the Aun-ZnO contact from Ohmic to rectifying with H2 O2 pretreatment was studied systematically using I-V measurements, x-ray photoemission spectroscopy, positron annihilation spectroscopy, and deep level transient spectroscopy. H2 O2 treatment did not affect the carbon surface contamination or the EC -0.31 eV deep level, but it resulted in a significant decrease of the surface OH contamination and the formation of vacancy-type defects (Zn vacancy or vacancy cluster) close to the surface. The formation of a rectifying contact can be attributed to the reduced conductivity of the surface region due to the removal of OH and the formation of vacancy-type defects. © 2007 American Institute of Physics.published_or_final_versio