Highly sensitive magnetite nano clusters for MR cell imaging

High sensitivity and suitable sizes are essential for magnetic iron oxide contrast agents for cell imaging. In this study, we have fabricated highly MR sensitive magnetite nanoclusters (MNCs) with tunable sizes. These clusters demonstrate high MR sensitivity. Especially, water suspensions of the MNCs with average size of 63 nm have transverse relaxivity as high as 630 s-1mM-1, which is among the most sensitive iron oxide contrast agents ever reported. Importantly, such MNCs have no adverse effects on cells (RAW 264.7). When used for cell imaging, they demonstrate much higher efficiency and sensitivity than those of SHU555A (Resovist), a commercially available contrast agent, both in vitro and in vivo, with detection limits of 3,000 and 10,000 labeled cells, respectively. The studied MNCs are sensitive for cell imaging and promising for MR cell tracking in clinics

BMP Signaling Mediated by BMPR1A in Osteoclasts Negatively Regulates Osteoblast Mineralization Through Suppression of Cx43

Osteoblasts and osteoclasts are well orchestrated through different mechanisms of communication during bone remodeling. Previously, we found that osteoclast‐specific disruption of one of the BMP receptors, Bmpr1a, results in increased osteoblastic bone formation in mice. We hypothesized that BMPR1A signaling in osteoclasts regulates production of either membrane bound proteins or secreted molecules that regulated osteoblast differentiation. In our current study, we co‐cultured wild‐type osteoblasts with either control osteoclasts or osteoclasts lacking BMPR1A signaling activity. We found that loss of Bmpr1a in osteoclasts promoted osteoblast mineralization in vitro. Further, we found that the expression of Cx43/Gja1 in the mutant osteoclasts was increased, which encoded for one of the gap junction proteins connexin 43/gap junction alpha 1. Knockdown of Gja1 in the mutant osteoclasts for Bmpr1a reduced osteoblastic mineralization when co‐cultured. Our findings suggest that GJA1 may be one of the downstream targets of BMPR1A signaling in osteoclasts that mediates osteoclast–osteoblast communication during bone remodeling. J. Cell. Biochem. 118: 605–614, 2017. © 2016 Wiley Periodicals, Inc.Disruption of Bmpr1a in osteoclasts promoted osteoblast mineralization when co‐cultured. Up‐regulation of gap junction Cx43/Gja1 in mutant osteoclasts is responsible for the enhanced osteoblast function.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135668/1/jcb25746_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135668/2/jcb25746.pd

Z-source matrix rectifier

This paper presents a novel Z-source matrix rectifier(ZSMR). To overcome the inherent disadvantage that the voltage transfer ratio for traditional matrix rectifier cannot be more than 0.866, a Z-source network has been combined with the matrix rectifier. The proposed rectifier realizes a voltage-boost function and the Z-source network also serves as power storage and guarantees double filtration grade at the output of the rectifier. The open-circuit zero state is required to obtain the voltage-boost function and ensure the output angle of the current vector to be invariant to obtain the expected power factor. In addition, to widely extend the voltage transfer ratio of the proposed rectifier, this paper presents the switched-inductor matrix rectifier(SL-ZSMR) and tapped-inductor matrix rectifier(TL-ZSMR). The corresponding circuit topologies, control strategies and operating principles are introduced. Both simulation and experiment results are shown to verify the theoretical analysis

Intermediate coherent-phase(PB) states of radiation fields and their nonclassical properties

Intermediate states interpolating coherent states and Pegg-Barnett phase states are investigated using the ladder operator approach. These states reduce to coherent and Pegg-Barnett phase states in two different limits. Statistical and squeezing properties are studied in detail.Comment: 9 pages, 3 EPS figures, use epsf.sty. Accepted for publication in Phys.Lett.

Preparation of Phase Homogeneous Mn-Zn Ferrite Powder by Spray Pyrolysis

Two kinds of aqueous precursor solutions are used to synthesize Mn-Zn ferrite powders: (i) nitrate (NO) precursor-derived from solutions of Mn(NO3)2, Zn(NO3)2, and Fe(NO3)3; and (ii) acetate (AC) precursor-derived from solutions of Mn(CH3COOO)2, Zn(CHCH3COOO)2, and Fe(NO3)3. The composition of the powders synthesized from the precursor AC is very uniform, whereas powders derived from the precursor NO have Mn and Zn segregated on the particle surfaces. In addition, the powders synthesized from precursor AC are solid spherical particles with fine porosity, whereas many hollow and fragmented particles are observed in the powder derived from precursor NO. Overall, the properties of Mn-Zn ferrite cores prepared from the precursor AC are superior to those prepared from the precursor NO. The reasons for the differences are explained and described in detail. The AC precursor powders synthesized by spray pyrolysis produced Mn-Zn ferrite cores with good magnetic properties

Delivering hydrophilic and hydrophobic chemotherapeutics simultaneously by magnetic mesoporous silica nanoparticles to inhibit cancer cells

Using nanoparticles to deliver chemotherapeutics offers new opportunities for cancer therapy, but challenges still remain when they are used for the delivery of multiple drugs, especially for the synchronous delivery of hydrophilic and hydrophobic drugs in combination therapies. In this paper, we developed an approach to deliver hydrophilic–hydrophobic anticancer drug pairs by employing magnetic mesoporous silica nanoparticles (MMSNs). We prepared 50 nm-sized MMSNs with uniform pore size and evaluated their capability for the loading of two combinations of chemotherapeutics, namely doxorubicin–paclitaxel and doxorubicin–rapamycin, by means of sequential adsorption from the aqueous solution of doxorubicin and nonaqueous solutions of paclitaxel or rapamycin. Experimental results showed that the present strategy successfully realized the co-loading of hydrophilic and hydrophobic drugs with high-loading content and widely tunable ratio range. We elaborate on the theory behind the molecular interaction between the silica hydroxyl groups and drug molecules, which underlie the controllable loading, and the subsequent release of the drug pairs. Then we demonstrate that the multidrug-loaded MMSNs could be easily internalized by A549 human pulmonary adenocarcinoma cells, and produce enhanced tumor cell apoptosis and growth inhibition as compared to single-drug loaded MMSNs. Our study thus realized simultaneous and dose-tunable delivery of hydrophilic and hydrophobic drugs, which were endowed with improved anticancer efficacy. This strategy could be readily extended to other chemotherapeutic combinations and might have clinically translatable significance

Deletion of BMP receptor type IB decreased bone mass in association with compromised osteoblastic differentiation of bone marrow mesenchymal progenitors

We previously found that disruption of two type I BMP receptors, Bmpr1a and Acvr1, respectively, in an osteoblast-specific manner, increased bone mass in mice. BMPR1B, another BMP type I receptor, is also capable of binding to BMP ligands and transduce BMP signaling. However, little is known about the function of BMPR1B in bone. In this study, we investigated the bone phenotype in Bmpr1b null mice and the impacts of loss of Bmpr1b on osteoblasts and osteoclasts. We found that deletion of Bmpr1b resulted in osteopenia in 8-week-old male mice, and the phenotype was transient and gender specific. The decreased bone mass was neither due to the changes in osteoblastic bone formation activity nor osteoclastic bone resorption activity in vivo. In vitro differentiation of Bmpr1b null osteoclasts was increased but resorption activity was decreased. Calvarial pre-osteoblasts from Bmpr1b mutant showed comparable differentiation capability in vitro, while they showed increased BMP-SMAD signaling in culture. Different from calvarial pre-osteoblasts, Bmpr1b mutant bone marrow mesenchymal progenitors showed compromised differentiation in vitro, which may be a reason for the osteopenic phenotype in the mutant mice. In conclusion, our results suggested that BMPR1B plays distinct roles from BMPR1A and ACVR1 in maintaining bone mass and transducing BMP signaling