126
|
Liu Y, Ma D, Ji C. Zinc fingers and homeoboxes family in human diseases. Cancer Gene Ther 2015; 22:223-6. [PMID: 25857360 DOI: 10.1038/cgt.2015.16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/07/2015] [Accepted: 02/09/2015] [Indexed: 12/13/2022]
Abstract
The zinc-fingers and homeoboxes (ZHX) family is a group of nuclear homodimeric transcriptional repressors that interact with a subunit of nuclear factor-Y (NF-YA) and contain two C2H2-type zinc fingers and five homeobox DNA-binding domains. The members of ZHX family form homodimers or heterodimers with other members or a subunit of NF-YA to repress transcription. ZHX family members function in hematopoietic cell development and differentiation, and neural progenitor maintenance. Dysfunction of ZHX family members correlates with the development and progression of various diseases, including hepatocellular carcinoma (HCC), hematological diseases, neurological diseases and glomerular diseases. Furthermore, low expression of ZHX is associated with poor prognosis in malignancies. This review provides an update on the role of ZHX family in development and its function in cancer, with special emphasis on HCC and hematological malignant diseases.
Collapse
|
127
|
Jin Z, Chan H, Ning J, Lu K, Ma D. The role of hydrogen sulfide in pathologies of the vital organs and its clinical application. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2015; 66:169-179. [PMID: 25903948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/15/2015] [Indexed: 06/04/2023]
Abstract
Hydrogen sulfide (H(2)S) is one of the more recently recognised gaseous transmitters that have been shown to be involved in a large range of cellular functions. While H(2)S generally has pro-survival and anti-apoptotic effects, at higher concentrations, this effect is reversed and it becomes anti-proliferative and pro-apoptotic instead. H(2)S is also involved in a number of organ specific functions such as thermoregulation, modulating myocardial activity and broncho-dilation. H(2)S has organ protective effects in ischaemia, acting as a vasodilator and negative inotrope to reduce blood pressure. H(2)S generally has a protective effect in acute inflammation and oxidative stress from causes such as allergy and toxins. In chronic organ pathology, low H(2)S levels have been observed in a number of different diseases, while there is evidence that H(2)S may be beneficial in a number of chronic organ degenerations. A number of studies on human tissue and cell line conducted in the recent years shows H(2)S exerting largely similar effects in humans as those in animals. This may indicate that the pharmacological potential of H(2)S modulators could have therapeutic value in a large range of acute conditions such as ischaemia, toxin exposure as well as chronic conditions such as hypertension, lung diseases and neurodegenerative disease.
Collapse
|
128
|
Dinca LE, De Marchi F, MacLeod JM, Lipton-Duffin J, Gatti R, Ma D, Perepichka DF, Rosei F. Pentacene on Ni(111): room-temperature molecular packing and temperature-activated conversion to graphene. NANOSCALE 2015; 7:3263-3269. [PMID: 25619890 DOI: 10.1039/c4nr07057g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We investigate, using scanning tunnelling microscopy, the adsorption of pentacene on Ni(111) at room temperature and the behaviour of these monolayer films with annealing up to 700 °C. We observe the conversion of pentacene into graphene, which begins from as low as 220 °C with the coalescence of pentacene molecules into large planar aggregates. Then, by annealing at 350 °C for 20 minutes, these aggregates expand into irregular domains of graphene tens of nanometers in size. On surfaces where graphene and nickel carbide coexist, pentacene shows preferential adsorption on the nickel carbide phase. The same pentacene to graphene transformation was also achieved on Cu(111), but at a higher activation temperature, producing large graphene domains that exhibit a range of moiré superlattice periodicities.
Collapse
|
129
|
Ma D, Yao H. Transpalatal screw traction: a simple technique for the management of sagittal fractures of the maxilla and palate. Int J Oral Maxillofac Surg 2015; 44:671. [PMID: 25682462 DOI: 10.1016/j.ijom.2015.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 01/21/2015] [Indexed: 11/25/2022]
|
130
|
Ma D, Fang Q, Wang P, Gao R, Sun J, Li Y, Hu XY, Wang JS. Downregulation of HO-1 promoted apoptosis induced by decitabine via increasing p15INK4B promoter demethylation in myelodysplastic syndrome. Gene Ther 2015; 22:287-96. [DOI: 10.1038/gt.2015.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 11/08/2014] [Accepted: 12/16/2014] [Indexed: 11/09/2022]
|
131
|
Gifford G, Sim J, Horne A, Ma D. Health status, late effects and long-term survivorship of allogeneic bone marrow transplantation: a retrospective study. Intern Med J 2015; 44:139-47. [PMID: 24320824 DOI: 10.1111/imj.12336] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 11/09/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Survival after allogeneic haemopoietic stem cell transplantation (allo-HSCT) has improved because of advancements in allo-HSCT. Allo-HSCT has been performed in Australia since the late 1970s. However, there are few published data about health problems of allo-HSCT survivors in Australia. AIMS Identify health issues in long-term survivors of allo-HSCT in an Australian centre to manage better and prevent long-term complications. METHODS The health records of all patients of allo-HSCT in a single centre from January 2000 to December 2007 and survived beyond 2 years were assessed. RESULTS Ninety-nine of the 200 allo-HSCT patients survived beyond 2 years, and the median time from allo-HSCT was 74 months. Twenty-eight per cent died at a median of 37 months after allo-HSCT because of relapsed malignancy (12%), stroke (1%), infection (3%), chronic graft versus host disease (9%), secondary malignancy (2%) and unknown cause (1%). Ninety-one per cent reported one or more chronic health conditions. Health issues were chronic graft versus host disease (70%); respiratory (66%), ophthalmic (40%), bone (33%), and renal (26%) problems; and malignancies (14% skin, 3% solid organ). Seventy-nine per cent resumed vocation at full or reduced capacity 2 years after allo-HSCT. Clinicians identified 40% with quality of life (QOL) issues, but survivors' self-reported QOL was comparable with the general Australian population. CONCLUSION This study shows that allo-HSCT patients are living with high burdens of chronic diseases that warrant lifelong surveillance and engagement with healthcare. Structured, multi-disciplinary care as recommended by published guidelines for allo-HSCT survivors may reduce long-term effects and improve their outcomes.
Collapse
|
132
|
Gao R, Ma D, Wang P, Sun J, Wang J, Fang Q. Role of heme oxygenase-1 in demethylating effects on SKM-1 cells induced by decitabine. GENETICS AND MOLECULAR RESEARCH 2015; 14:17788-98. [DOI: 10.4238/2015.december.22.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
133
|
Buggy DJ, Borgeat A, Cata J, Doherty DG, Doornebal CW, Forget P, Gottumukkala V, Gottschalk A, Gupta A, Gupta K, Hales TG, Hemmings HC, Hollmann MW, Kurz A, Ma D, Parat MO, Sessler DI, Shorten G, Singleton P. Consensus statement from the BJA Workshop on Cancer and Anaesthesia. Br J Anaesth 2015; 114:2-3. [PMID: 25104229 DOI: 10.1093/bja/aeu262] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
134
|
Luo X, Zhao H, Hennah L, Ning J, Liu J, Tu H, Ma D. Impact of isoflurane on malignant capability of ovarian cancer in vitro. Br J Anaesth 2014; 114:831-9. [PMID: 25501719 DOI: 10.1093/bja/aeu408] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Metastatic recurrence of ovarian cancer is the foremost cause of postoperative mortality. With recent research indicating that inhalation of anaesthetics may influence cancer cell behaviour, this study investigated the effects of isoflurane on the expression of tumorigenic markers and proliferative capacity in ovarian cancer cells. METHODS Ovarian cancer (SK-OV3) cells were cultured and then exposed to 2% isoflurane for 2 h. The expression of markers involved in cell proliferation, angiogenesis, and migration were assessed up to 24 h after treatment using immunofluorescence staining, western blotting, and flow cytometry. The effects of isoflurane on in vitro angiogenesis and migration were also determined. RESULTS Isoflurane exposure significantly increased insulin-like growth factor (IGF)-1 and IGF-1R expression, cell cycle progression, and cell proliferation in SK-OV3 cells. Increased expression of the angiogenic markers vascular endothelial growth factor (VEGF) by 56% (P<0.05) and angiopoietin-1 by 62% (P<0.05) was also observed 24 h after isoflurane exposure together with an enhanced in vitro angiogenesis. Cell migration was significantly increased after exposure to isoflurane together with increased production of both matrix metalloproteinases 2 and 9 (both P<0.05) by almost five-fold relative to control. These effects were abolished when IGF-1R signalling was blocked either by neutralizing antibody or by small interfering RNA. CONCLUSIONS Our data indicate that isoflurane increases the malignant potential of ovarian cancer cells through the up-regulation of markers associated with the cell cycle, proliferation, and angiogenesis. This study warrants further investigations.
Collapse
|
135
|
Stoica GM, Stoica AD, An K, Ma D, Vogel SC, Carpenter JS, Wang XL. Extracting grain-orientation-dependent data fromin situtime-of-flight neutron diffraction. I. Inverse pole figures. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576714023036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The problem of calculating the inverse pole figure (IPF) is analyzed from the perspective of the application of time-of flight neutron diffraction toin situmonitoring of the thermomechanical behavior of engineering materials. On the basis of a quasi-Monte Carlo (QMC) method, a consistent set of grain orientations is generated and used to compute the weighting factors for IPF normalization. The weighting factors are instrument dependent and were calculated for the engineering materials diffractometer VULCAN (Spallation Neutron Source, Oak Ridge National Laboratory). The QMC method is applied to face-centered cubic structures and can be easily extended to other crystallographic symmetries. Examples include 316LN stainless steelin situloaded in tension at room temperature and an Al–2%Mg alloy, substantially deformed by cold rolling andin situannealed up to 653 K.
Collapse
|
136
|
Badve C, Yu A, Ma D, Jiang Y, Deshmane A, Gulani V, Sunshine J, Sloan A, Griswold M. NI-07 * MAGNETIC RESONANCE FINGERPRINTING OF BRAIN TUMORS: INITIAL CLINICAL RESULTS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou264.7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
137
|
Ma D, Sarkaria J, Peng S, Byron S, Craig D, Carpten J, Berens M, O'Neill B, Schroeder M, Tran N. GE-19 * GENOMICS GUIDED THERAPEUTIC APPROACH FOR THE TREATMENT OF GLIOBLASTOMA MULTIFORME (GBM) USING NEXT GENERATION SEQUENCING (NGS) TECHNOLOGIES. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou256.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
138
|
Ma D, Galanis E, Peller P, Ligon K, Giannini C, Sarkaria J. BI-20 * GENETIC PROFILING FOR EARLY EVEROLIMUS SENSITIVITY IN NEWLY DIAGNOSED GLIOBLASTOMA PATIENTS ENROLLED ON NCCTG N057K. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou239.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
139
|
Stoica G, Stoica A, Miller M, Ma D. Temperature-dependent elastic anisotropy and mesoscale deformation in a nanostructured ferritic alloy. Nat Commun 2014; 5:5178. [DOI: 10.1038/ncomms6178] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 09/08/2014] [Indexed: 11/09/2022] Open
|
140
|
Cui L, Xu S, Ma D, Wu B. Response to the 'Letter to the editor by Xu JL'. Int Endod J 2014; 47:1000. [PMID: 25203172 DOI: 10.1111/iej.12285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
141
|
Ma D, Miao XX, Jiang GH, Bai HB, Chen ZQ. An Experimental Investigation of Permeability Measurement of Water Flow in Crushed Rocks. Transp Porous Media 2014. [DOI: 10.1007/s11242-014-0385-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
142
|
Kim T, Xu R, Yau T, Ma B, Pan H, Xu J, Bai Y, Chi Y, Wang L, Yeh K, Bi F, Cheng Y, Le A, Lin J, Liu T, Ma D, Shapiro J, Kalmus J, Qin S, Li J. Concur: a Randomized, Placebo-Controlled Phase 3 Study of Regorafenib (Reg) Monotherapy in Asian Patients with Previously Treated Metastatic Colorectal Cancer (Mcrc). Ann Oncol 2014. [DOI: 10.1093/annonc/mdu333.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
143
|
Ma D, Guo X, Yao H, Chen J. Transpalatal screw traction: a simple technique for the management of sagittal fractures of the maxilla and palate. Int J Oral Maxillofac Surg 2014; 43:1465-7. [PMID: 25156084 DOI: 10.1016/j.ijom.2014.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 04/13/2014] [Accepted: 07/23/2014] [Indexed: 11/19/2022]
Abstract
Sagittal fractures of the maxilla and palate are uncommon in clinical practice. Current methods for the management of such fractures have advantages and limitations. The authors present the simple and practical technique of bilateral transpalatal screw traction to manage this fracture type.
Collapse
|
144
|
Hu ZC, Tang B, Guo D, Zhang J, Liang YY, Ma D, Zhu JY. Expression of insulin-like growth factor-1 receptor in keloid and hypertrophic scar. Clin Exp Dermatol 2014; 39:822-8. [PMID: 25154292 PMCID: PMC4232319 DOI: 10.1111/ced.12407] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Keloid and hypertrophic scar (HS) are two pathological forms of excessive dermal fibrosis, which are due to aberrant wound-healing responses. Accumulating evidence suggests that aberrant activity of growth factors and increased numbers of growth factor receptors play an important role in the formation of pathological scar. AIM We examined the expression level of insulin-like growth factor-1 receptor (IGF-IR) in keloid, HS and normal skin. METHODS IGF-IR expression was analyzed by immunohistochemistry, real-time PCR and western blotting on tissues and fibroblasts from 30 patients, comprising 10 patients with keloid and 20 with HS (10 with immature and 10 with mature HS), and from 10 age-matched and sex-matched healthy controls. RESULTS Immunoreactivity to IGF-IR was found in dermal fibroblasts of keloid (90%), immature HS, (80%) and mature HS (30%), but not in normal skin. There was no statistically significant difference in immunoreactivity scores between keloid and immature HS, but there was a significant difference (P < 0.01) between mature and immature HS. Real-time PCR and western blot analysis confirmed that there was high expression of IGF-IR in keloid and immature HS fibroblasts, but not in mature HS or normal skin fibroblasts. IGF-IR was expressed in the overlying epidermis, and there was no significant difference between the groups. CONCLUSIONS IGF-IR may be involved in the pathogenesis of keloid and HS. Given that IGF-IR are predominantly expressed on dermal fibroblasts, targeting of IGF-IR in fibroblasts may be of benefit to prevent scarring.
Collapse
|
145
|
Huang H, Benzonana LL, Zhao H, Watts HR, Perry NJS, Bevan C, Brown R, Ma D. Prostate cancer cell malignancy via modulation of HIF-1α pathway with isoflurane and propofol alone and in combination. Br J Cancer 2014; 111:1338-49. [PMID: 25072260 PMCID: PMC4183852 DOI: 10.1038/bjc.2014.426] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/23/2014] [Accepted: 07/03/2014] [Indexed: 12/17/2022] Open
Abstract
Background: Surgery is considered to be the first line treatment for solid tumours. Recently, retrospective studies reported that general anaesthesia was associated with worse long-term cancer-free survival when compared with regional anaesthesia. This has important clinical implications; however, the mechanisms underlying those observations remain unclear. We aim to investigate the effect of anaesthetics isoflurane and propofol on prostate cancer malignancy. Methods: Prostate cancer (PC3) cell line was exposed to commonly used anaesthetic isoflurane and propofol. Malignant potential was assessed through evaluation of expression level of hypoxia-inducible factor-1α (HIF-1α) and its downstream effectors, cell proliferation and migration as well as development of chemoresistance. Results: We demonstrated that isoflurane, at a clinically relevant concentration induced upregulation of HIF-1α and its downstream effectors in PC3 cell line. Consequently, cancer cell characteristics associated with malignancy were enhanced, with an increase of proliferation and migration, as well as development of chemoresistance. Inhibition of HIF-1α neosynthesis through upper pathway blocking by a PI-3K-Akt inhibitor or HIF-1α siRNA abolished isoflurane-induced effects. In contrast, the intravenous anaesthetic propofol inhibited HIF-1α activation induced by hypoxia or CoCl2. Propofol also prevented isoflurane-induced HIF-1α activation, and partially reduced cancer cell malignant activities. Conclusions: Our findings suggest that modulation of HIF-1α activity by anaesthetics may affect cancer recurrence following surgery. If our data were to be extrapolated to the clinical setting, isoflurane but not propofol should be avoided for use in cancer surgery. Further work involving in vivo models and clinical trials is urgently needed to determine the optimal anaesthetic regimen for cancer patients.
Collapse
|
146
|
Cui J, He W, Yi B, Zhao H, Lu K, Ruan H, Ma D. mTOR pathway is involved in ADP-evoked astrocyte activation and ATP release in the spinal dorsal horn in a rat neuropathic pain model. Neuroscience 2014; 275:395-403. [PMID: 24976516 DOI: 10.1016/j.neuroscience.2014.06.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/10/2014] [Accepted: 06/13/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND ATP/ADP-evoked spinal astrocyte activation plays a vital role in the development of neuropathic pain. We aim to investigate the role of mammalian target of rapamycin (mTOR) pathway on the spinal astrocyte activation in the neuropathic pain development in rats. METHODS Sprague Dawley (SD) rats were subjected to chronic constriction of the sciatic nerve (CCI). Rapamycin or ADP was intrathecally injected daily to explore their effects on spinal astrocyte activation and pain development. Expression of glial fibrillary acidic protein (GFAP) and mTOR in the spinal dorsal horn was assessed by immunohistochemistry. Von Frey hairs and Hargreaves paw withdrawal test were conducted to evaluate mechanical allodynia and thermal sensitivity, respectively. Firefly luciferase ATP assay was used to assess the change of ATP level in cerebrospinal fluid (CSF) and medium of cultured astrocytes. RESULTS GFAP expression was enhanced in the ipsilateral spinal dorsal horn from day 3 after surgery. GFAP and mTOR expression in the rat spinal dorsal horn on post-surgical day 14 was enhanced by daily intrathecal injection of ADP, which was inhibited by rapamycin. Rapamycin decreased lower mechanical pain threshold and the thermal withdrawal latency. Intrathecal injection of ADP enhanced the ATP release, which was partially inhibited by rapamycin. Study of cultured astrocytes indicated that ATP could be released from astrocytes. CONCLUSION Our data demonstrated that ADP enhanced neuropathic pain in CCI rats, which was inhibited by rapamycin. This study indicates that targeting mTOR pathway could serve as a novel therapeutic strategy in neuropathic pain management.
Collapse
|
147
|
Dinca LE, MacLeod JM, Lipton-Duffin J, Fu C, Ma D, Perepichka DF, Rosei F. Tip-induced C-H activation and oligomerization of thienoanthracenes. Chem Commun (Camb) 2014; 50:8791-3. [PMID: 24967741 DOI: 10.1039/c4cc03719g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The tip of a scanning tunneling microscope (STM) can be used to dehydrogenate freely-diffusing tetrathienoanthracene (TTA) molecules on Cu(111), trapping the molecules into metal-coordinated oligomeric structures. The process proceeds at bias voltages above ~3 V and produces organometallic structures identical to those resulting from the thermally-activated cross-coupling of a halogenated analogue. The process appears to be substrate dependent: no oligomerization was observed on Ag(111) or HOPG. This approach demonstrates the possibility of controlled synthesis and nanoscale patterning of 2D oligomer structures on selected surfaces.
Collapse
|
148
|
Li HX, Gao JE, Wu Y, Jiao ZB, Ma D, Stoica AD, Wang XL, Ren Y, Miller MK, Lu ZP. Enhancing glass-forming ability via frustration of nano-clustering in alloys with a high solvent content. Sci Rep 2014; 3:1983. [PMID: 23760427 PMCID: PMC3680804 DOI: 10.1038/srep01983] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/24/2013] [Indexed: 11/18/2022] Open
Abstract
The glass-forming ability (GFA) of alloys with a high-solvent content such as soft magnetic Fe-based and Al-based alloys is usually limited due to strong formation of the solvent-based solid solution phase. Herein, we report that the GFA of soft magnetic Fe-based alloys (with >70 at.% Fe to ensure large saturation magnetization) could be dramatically improved by doping with only 0.3 at.% Cu which has a positive enthalpy of mixing with Fe. It was found that an appropriate Cu addition could enhance the liquid phase stability and crystallization resistance by destabilizing the α-Fe nano-clusters due to the necessity to redistribute the Cu atoms. However, excessive Cu doping would stimulate nucleation of the α-Fe nano-clusters due to the repulsive nature between the Fe and Cu atoms, thus deteriorating the GFA. Our findings provide new insights into understanding of glass formation in general.
Collapse
|
149
|
Zhao H, Fan Z, Liang H, Selopal GS, Gonfa BA, Jin L, Soudi A, Cui D, Enrichi F, Natile MM, Concina I, Ma D, Govorov AO, Rosei F, Vomiero A. Controlling photoinduced electron transfer from PbS@CdS core@shell quantum dots to metal oxide nanostructured thin films. NANOSCALE 2014; 6:7004-7011. [PMID: 24839954 DOI: 10.1039/c4nr01562b] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
N-type metal oxide solar cells sensitized by infrared absorbing PbS quantum dots (QDs) represent a promising alternative to traditional photovoltaic devices. However, colloidal PbS QDs capped with pure organic ligand shells suffer from surface oxidation that affects the long term stability of the cells. Application of a passivating CdS shell guarantees the increased long term stability of PbS QDs, but can negatively affect photoinduced charge transfer from the QD to the oxide and the resulting photoconversion efficiency (PCE). For this reason, the characterization of electron injection rates in these systems is very important, yet has never been reported. Here we investigate the photoelectron transfer rate from PbS@CdS core@shell QDs to wide bandgap semiconducting mesoporous films using photoluminescence (PL) lifetime spectroscopy. The different electron affinity of the oxides (SiO2, TiO2 and SnO2), the core size and the shell thickness allow us to fine tune the electron injection rate by determining the width and height of the energy barrier for tunneling from the core to the oxide. Theoretical modeling using the semi-classical approximation provides an estimate for the escape time of an electron from the QD 1S state, in good agreement with experiments. The results demonstrate the possibility of obtaining fast charge injection in near infrared (NIR) QDs stabilized by an external shell (injection rates in the range of 110-250 ns for TiO2 films and in the range of 100-170 ns for SnO2 films for PbS cores with diameters in the 3-4.2 nm range and shell thickness around 0.3 nm), with the aim of providing viable solutions to the stability issues typical of NIR QDs capped with pure organic ligand shells.
Collapse
|
150
|
Li J, Qin S, Yau T, Ma B, Pan H, Xu J, Bai Y, Chi Y, Wang L, Yeh K, Bi F, Cheng Y, Le A, Lin J, Liu T, Ma D, Kappeler C, Kalmus J, Xu R, Kim T. Concur: A Randomized, Double-Blind, Placebo-Controlled Phase 3 Study of Regorafenib Monotherapy in Asian Patients with Previously Treated Metastatic Colorectal Cancer (MCRC). Ann Oncol 2014. [DOI: 10.1093/annonc/mdu193.23] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|