In this paper, we describe the fabrication and characterization of solution-processed CH 3 NH 3 PbI 3 photodetectors that combine a high photoconductive gain with a broad spectral response, ranging from the UV to the NIR. Benefi tting from the trapped-hole-induced electron injection, the CH 3 NH 3 PbI 3 photodetector works as a photodiode in the dark and shows large photoconductive gain under illumination. The maximum device gain reached 489 ± 6 at a very low driving voltage of −1 V.The devices studied here have a layered inverted structure ( Figure 1 a) where indium tin oxide (ITO) is the cathode, CH 3 NH 3 PbI 3 is the active layer, 4,4′-bis[(p-trichlorosilylpropylphenyl)phenylamino]-biphenyl (TPD-Si 2 ) serves as the hole transporting/electron blocking layer, molybdenum trioxide (MoO 3 ) is used for anode work function modifi cation, and silver (Ag) as the anode. The CH 3 NH 3 PbI 3 layers were prepared by thermal-annealing induced interdiffusion of the two perovskite precursors (PbI 2 , CH 3 NH 3 I) by way of a method that has recently been developed in our group to fabricate very effi cient solar cells with high yield. [ 8 ] In short, lead iodide (PbI 2 ) fi lms were deposited fi rst on ITO/glass substrates by spin-coating. A second layer consisting of methylammonium iodide (CH 3 NH 3 I) (hereafter MAI) was then spin-coated on top of the dried PbI 2 fi lm, followed by thermal annealing at 105 °C for 60 min. Scanning electron microscopy (SEM) measurements ( Figure S1, Supporting Information) showed that the interdiffusion method allows the preparation of CH 3 NH 3 PbI 3 fi lms on ITO that are continuous and uniform, which is particularly important for obtaining leakage-free photodetectors. The absorption curve in Figure 1 b shows that the CH 3 NH 3 PbI 3 fi lms have a broad absorption spectrum that ranges from 300 nm (UV) to 800 nm (NIR).The photo-and dark-current densities-voltage ( J -V ) curves of CH 3 NH 3 PbI 3 photodetectors (Figure 1 c) show a transition from a diode-rectifying behavior in the dark, to photoconduction under illumination. Under illumination, both the forward and the reverse bias currents increased dramatically, with the reverse bias current increasing more sharply than the forward bias current. The rectifying effect completely disappeared, and an ohmic conduction behavior (symmetrical photocurrent with respect to the y -axis) was observed when exposing the device to white light irradiation (10 mW cm −2 ). For comparison, the J -V curve of a high performance solar cell (where exactly the same CH 3 NH 3 PbI 3 fabrication procedure was applied) with almost 100% external quantum effi ciency under the same light intensity is also shown in Figure 1 c. The reference photovoltaic (PV) device has a structure of ITO/PEDOT:PSS/ MAPbI 3 /[6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) (20 nm)/C 60 (20 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (8 nm)/aluminium (Al) (100 nm). [ 8 ] Although Weak light sensing in the ultraviolet (UV), visible, and nearinfrared (NIR) range has a wide ...

photodetector; the corresponding responsivity and normalized detectivity were 0.5 A/W and 2.3 × 10 9 Jones, respectively. [ 19 ] It is reasonable to anticipate a better detector performance if the photon-to-current conversion effi ciency can be further improved.In this manuscript, we report a PbS-based NIR hybrid photodetector with an EQE above 100% by the integration of zinc oxide (ZnO) QDs to induce a photoconductive gain. The active layer of the photodetector can be prepared by a single cycle of spin-coating. Moreover, the photodetector shows a tenfold higher responsivity than that of commercial SiC and Si photodetectors in the UV-visible range at room temperature.The structure of the dual-QD hybrid photodetector is presented in Figure 1 a. The device structure is similar to bulk heterojunction solar cells with indium tin oxide (ITO) and aluminium used as the anode and cathode, respectively. Both PbS and ZnO QDs were introduced into the polymer blends. The PbS QDs in this study were synthesized by a hot-injection technique involving the quick injection of bis(trimethylsilylsulphide) into a hot lead precursor. [21][22][23] The average diameter of PbS QDs was about 3.3 nm (maximum 3.7 nm), calculated from the absorption curve. Ligand exchange was processed in the solution phase, and the obtained butylamine-capped PbS QDs were dissolved in 1,2-dichlorobenzene (DCB).ZnO QDs were prepared by the hydrolysis method developed by Pacholski, [24][25][26] where ZnO QDs are obtained by quickly adding potassium hydroxide solution into zinc acetate methanol solution. The diameter of the ZnO QDs was approximately 5 nm and the obtained ZnO QDs were also dissolved in DCB. The synthesis method is highly reproducible and reliable, and the ZnO QD solution is almost transparent and can be kept at room temperature for more than three weeks.The polymer blend consists of hole conductor P3HT and electron conductor PCBM which has been extensively studied in an organic solar cell. [ 27,28 ] ZnO QDs and PbS QDs were mixed with a P3HT:PCBM polymer blend separately, and then mixed together right before the coating of the quartenary blend fi lms to avoid the aggregation of ZnO and PbS QDs. Solvent and post-thermal annealing were performed in order to obtain an optimized fi lm morphology for better carrier separation and transportation in a polymer matrix (see the Experimental Section for details). Optical sensing from the ultraviolet (UV) to the near infrared (NIR) range have broad applications including imaging, telecommunications, biomedicine, environmental monitoring and defence sensing. [1][2][3] It is desirable to have a photodetector with a response spectrum covering a broad spectral range from UV to NIR. However, commercially available solid-state photodetectors have relatively narrow response spectra. For example, silicon photodetectors are only good for the visible/ NIR range, while high-end photodetectors made of SiC are generally selected for UV sensing. Organic/polymer photodetectors are attractive low-cost, uncooled candidates ...

BackgroundMesenchymal stem cells (MSCs) are the most promising cell types for bone regeneration and repair due to their osteogenic potential. MSC differentiation is precisely regulated and orchestrated by the mechanical and molecular signals from the extracellular environment, involving complex pathways regulated at both the transcriptional and post-transcriptional levels. However, the potential role of long noncoding RNA (lncRNA) in the osteogenic differentiation of human MSCs remains largely unclear.MethodsHere, we undertook the survey of differential coding and noncoding transcript expression profiling and functional network analysis during osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs) using human whole transcriptome microarray. The key pathways, mRNAs, and lncRNAs controlling osteogenic differentiation of BMSCs were identified by further bioinformatic analysis. The role of lncRNA in the osteogenic differentiation of MSCs was verified by lncRNA overexpression or knockdown methods.ResultsA total of 1269 coding transcripts with 648 genes significantly upregulated and 621 genes downregulated, and 1408 lncRNAs with 785 lncRNAs significantly upregulated and 623 lncRNAs downregulated were detected along with osteogenic differentiation. Bioinformatic analysis identified that several pathways may be associated with osteogenic differentiation potentials of BMSCs, such as the MAPK signaling pathway, the Jak-STAT signaling pathway, the Toll-like receptor signaling pathway, and the TGF-beta signaling pathway, etc. Bioinformatic analysis also revealed 13 core regulatory genes including seven mRNAs (GPX3, TLR2, BDKRB1, FBXO5, BRCA1, MAP3K8, and SCARB1), and six lncRNAs (XR_111050, NR_024031, FR374455, FR401275, FR406817, and FR148647). Based on the analysis, we identified one lncRNA, XR_111050, that could enhance the osteogenic differentiation potentials of MSCs.ConclusionsThe potential regulatory mechanisms were identified using bioinformatic analyses. We further predicted the interactions of differentially expressed coding and noncoding genes, and identified core regulatory factors by co-expression networks during osteogenic differentiation of BMSCs. Our results could lead to a better understanding of the molecular mechanisms of genes and lncRNAs, and their cooperation underlying MSC osteogenic differentiation and bone formation. We identified that one lncRNA, XR_111050, could be a potential target for bone tissue engineering.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-017-0485-6) contains supplementary material, which is available to authorized users.

Our results have identified a new function of SFRP2 and shed new light on the molecular mechanism underlying directed differentiation of stem cells of dental origin.

A variety of osteolytic factors have been identified from breast cancer cells leading to osteolysis, but less is known about which factor plays an essential role in the initiation process prior to the overt vicious osteolytic cycle. Here, we present in vitro and in vivo evidences to clarify the role of interleukin-11 (IL-11) as an essential contributor to breast cancer bone metastasis mediated osteolysis. Animal studies showed that bone specific metastatic BoM-1833 cells induce earlier onset of osteolysis and faster tumor growth compared with MCF7 and parental MDA-MB-231 cells in BALB/c-nu/nu nude mice. IL-11 was further screened and identified as the indispensable factor secreted by BoM-1833 cells inducing osteoclastogenesis independently of receptor activator of nuclear factor κB ligand (RANKL). Mechanistic investigation revealed that the JAK1/STAT3 signaling pathway as a downstream effector of IL-11, STAT3 activation further induces the expression of c-Myc, a necessary factor required for osteoclastogenesis. By inhibiting STAT3 phosphorylation, AG-490 was shown effective in reducing osteolysis and tumor growth in the metastatic niche. Overall, our results revealed the essential role and the underlying molecular mechanism of IL-11 in breast cancer bone metastasis mediated osteolysis. STAT3 targeting through AG-490 is a potential therapeutic strategy for mitigating osteolysis and tumor growth of bone metastatic breast cancer.