1
|
Dull JT, He X, Viereck J, Ai Q, Ramprasad R, Otani MC, Sorli J, Brandt JW, Carrow BP, Tinoco AD, Loo YL, Risko C, Rangan S, Kahn A, Rand BP. Thin-Film Organic Heteroepitaxy. Adv Mater 2023; 35:e2302871. [PMID: 37394983 DOI: 10.1002/adma.202302871] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/16/2023] [Indexed: 07/04/2023]
Abstract
Incorporating crystalline organic semiconductors into electronic devices requires understanding of heteroepitaxy given the ubiquity of heterojunctions in these devices. However, while rules for commensurate epitaxy of covalent or ionic inorganic material systems are known to be dictated by lattice matching constraints, rules for heteroepitaxy of molecular systems are still being written. Here, it is found that lattice matching alone is insufficient to achieve heteroepitaxy in molecular systems, owing to weak intermolecular forces that describe molecular crystals. It is found that, in addition, the lattice matched plane also must be the lowest energy surface of the adcrystal to achieve one-to-one commensurate molecular heteroepitaxy over a large area. Ultraviolet photoelectron spectroscopy demonstrates the lattice matched interface to be of higher electronic quality than a disordered interface of the same materials.
Collapse
Affiliation(s)
- Jordan T Dull
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Xu He
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Jonathan Viereck
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, Piscataway, NJ, 08854, USA
| | - Qianxiang Ai
- Department of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, KY, 40506, USA
| | - Ritika Ramprasad
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Maria Clara Otani
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Jeni Sorli
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Jason W Brandt
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Brad P Carrow
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Arthur D Tinoco
- Department of Chemistry, University of Puerto Rico-Río Piedras Campus, San Juan, PR, 00925, USA
| | - Yueh-Lin Loo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Chad Risko
- Department of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, KY, 40506, USA
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, Piscataway, NJ, 08854, USA
| | - Antoine Kahn
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Barry P Rand
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, 08544, USA
- Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, 08544, USA
| |
Collapse
|
2
|
Bisht RS, Park J, Yu H, Wu C, Tilak N, Rangan S, Park TJ, Yuan Y, Das S, Goteti U, Yi HT, Hijazi H, Al-Mahboob A, Sadowski JT, Zhou H, Oh S, Andrei EY, Allen MT, Kuzum D, Frano A, Dynes RC, Ramanathan S. Spatial Interactions in Hydrogenated Perovskite Nickelate Synaptic Networks. Nano Lett 2023; 23:7166-7173. [PMID: 37506183 DOI: 10.1021/acs.nanolett.3c02076] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
A key aspect of how the brain learns and enables decision-making processes is through synaptic interactions. Electrical transmission and communication in a network of synapses are modulated by extracellular fields generated by ionic chemical gradients. Emulating such spatial interactions in synthetic networks can be of potential use for neuromorphic learning and the hardware implementation of artificial intelligence. Here, we demonstrate that in a network of hydrogen-doped perovskite nickelate devices, electric bias across a single junction can tune the coupling strength between the neighboring cells. Electrical transport measurements and spatially resolved diffraction and nanoprobe X-ray and scanning microwave impedance spectroscopic studies suggest that graded proton distribution in the inhomogeneous medium of hydrogen-doped nickelate film enables this behavior. We further demonstrate signal integration through the coupling of various junctions.
Collapse
Affiliation(s)
- Ravindra Singh Bisht
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Jaeseoung Park
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Haoming Yu
- School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Chen Wu
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Nikhil Tilak
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Sylvie Rangan
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Tae J Park
- School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yifan Yuan
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Sarmistha Das
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Uday Goteti
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Hee Taek Yi
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Hussein Hijazi
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Abdullah Al-Mahboob
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Jerzy T Sadowski
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Seongshik Oh
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Eva Y Andrei
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Monica T Allen
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Duygu Kuzum
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Alex Frano
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Robert C Dynes
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Shriram Ramanathan
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, New Jersey 08854, United States
| |
Collapse
|
3
|
Bruevich V, Kasaei L, Rangan S, Hijazi H, Zhang Z, Emge T, Andrei EY, Bartynski RA, Feldman LC, Podzorov V. Intrinsic (Trap-Free) Transistors Based on Epitaxial Single-Crystal Perovskites. Adv Mater 2022; 34:e2205055. [PMID: 36026556 DOI: 10.1002/adma.202205055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/07/2022] [Indexed: 06/15/2023]
Abstract
The first experimental realization of the intrinsic (not dominated by defects) charge conduction regime in lead-halide perovskite field-effect transistors (FETs) is reported. The advance is enabled by: i) a new vapor-phase epitaxy technique that results in large-area single-crystalline cesium lead bromide (CsPbBr3 ) films with excellent structural and surface properties, including atomically flat surface morphology, essentially free from defects and traps at the level relevant to device operation; ii) an extensive materials analysis of these films using a variety of thin-film and surface probes certifying the chemical and structural quality of the material; and iii) the fabrication of nearly ideal (trap-free) FETs with characteristics superior to any reported to date. These devices allow the investigation of the intrinsic FET and (gated) Hall-effect carrier mobilities as functions of temperature. The intrinsic mobility is found to increase on cooling from ≈30 cm2 V-1 s-1 at room temperature to ≈250 cm2 V-1 s-1 at 50 K, revealing a band transport limited by phonon scattering. Establishing the intrinsic (phonon-limited) mobility provides a solid test for theoretical descriptions of carrier transport in perovskites, reveals basic limits to the technology, and points to a path for future high-performance perovskite electronic devices.
Collapse
Affiliation(s)
- Vladimir Bruevich
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Leila Kasaei
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Sylvie Rangan
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Hussein Hijazi
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Zhenyuan Zhang
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Thomas Emge
- Wright-Rieman Laboratories, Rutgers University, 610 Taylor Road, Piscataway, NJ, 08854, USA
| | - Eva Y Andrei
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Robert A Bartynski
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Leonard C Feldman
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Vitaly Podzorov
- Dept. of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| |
Collapse
|
4
|
|
5
|
Gismondi P, Kuzmin A, Unsworth C, Rangan S, Khalid S, Saha D. Understanding the Adsorption of Rare-Earth Elements in Oligo-Grafted Mesoporous Carbon. Langmuir 2022; 38:203-210. [PMID: 34962813 DOI: 10.1021/acs.langmuir.1c02403] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Rare-earth elements (REEs) are 17 elements of the periodic table primarily consisting of lanthanides. In modern society, the usage of REEs is ubiquitous in almost all modern gadgets and therefore efficient recovery and separation of REEs are of high importance. Selective adsorption and chelation of REEs in solid sorbents is a unique and sustainable process for their recovery. In this work, single-stranded oligos with 100 units of thymine were grafted onto carboxylated mesoporous carbon to synthesize a sorbent with phosphorus and oxygen functionalities. The sorbent was characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy-energy-dispersive X-ray spectroscopy. Three different REEs with varying atomic radii and densities, Lu, Dy, and La, were adsorbed onto the carbon from aqueous solutions. It was observed that the adsorbed amounts increased with the increase in the atomic radius or decrease in the atomic density. Calculation of the distribution coefficients for all the equilibrium adsorption amounts suggested that adsorption is more effective in the lower concentration region. The L3-edge X-ray absorption near-edge structure confirmed a 3+ oxidation state of REEs in the adsorbed phase. Extended X-ray absorption fine structure (EXAFS) confirmed the binding of REEs with oxygen functionalities in the adsorbed phase. The radial distribution functions calculated from the EXAFS data suggest a longer RE-O distance for La compared to those for Lu and Dy. The coordination numbers and Debye-Waller factors have typical values of about 8-9 atoms and 0.01-0.02 Å2, respectively.
Collapse
Affiliation(s)
- Pasquale Gismondi
- Chemical Engineering Department, Widener University, 1 University Place, Chester, Pennsylvania 19013, United States
| | - Alexei Kuzmin
- Institute of Solid State Physics, University of Latvia, Kengaraga Street 8, Riga LV-1063, Latvia
| | - Colin Unsworth
- Chemical Engineering Department, Widener University, 1 University Place, Chester, Pennsylvania 19013, United States
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Syed Khalid
- NSLS-II, Brookhaven National Laboratory, Rochester Avenue, Upton, New York 11973, United States
| | - Dipendu Saha
- Chemical Engineering Department, Widener University, 1 University Place, Chester, Pennsylvania 19013, United States
| |
Collapse
|
6
|
Affiliation(s)
- Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Jonathan Viereck
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Robert A. Bartynski
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| |
Collapse
|
7
|
Chen Y, Viereck J, Harmer R, Rangan S, Bartynski RA, Galoppini E. Helical Peptides Design for Molecular Dipoles Functionalization of Wide Band Gap Oxides. J Am Chem Soc 2020; 142:3489-3498. [PMID: 31977205 DOI: 10.1021/jacs.9b12001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The use of helical hexapeptides to establish a surface dipole layer on a TiO2 substrate, with the goal of influencing the energy levels of a coadsorbed chromophore, is explored. Two helical hexapeptides, synthesized from 2-amino isobutyric acid (Aib) residues, were protected at the N-terminus with a carboxybenzyl group (Z) and at the C-terminus carried either a carboxylic acid or an isophthalic acid (Ipa) anchor group to form Z-(Aib)6-COOH or Z-(Aib)6-Ipa, respectively. Using a combination of vibrational and photoemission spectroscopies, bonding of the two peptides to TiO2 surfaces (either nanostructured or single-crystal TiO2(110)) was found to be highly dependent on the anchor group, with Ipa establishing a monolayer much more efficiently than COOH. Furthermore, a monolayer of Z-(Aib)6-Ipa on TiO2(110) was exposed for different binding times to a solution of a zinc tetraphenylporphyrin (ZnTPP) derivative terminated with an Ipa anchor group (ZnTPP-P-Ipa). Photoemission spectroscopy revealed that ZnTPP-P-Ipa partly displaced Z-(Aib)6-Ipa, forming a coadsorbed monolayer on the oxide surface. The presence of the peptide molecular dipole shifted the HOMO levels of the ZnTPP group to lower energy by ∼300 meV, in accordance with a simple parallel plate capacitor model. These results suggest that a mixed-layer approach, involving coadsorption of a strong molecular dipole compound with a chromophore, is a versatile method to shift the energy levels of such chromophores with respect to the band edges of the substrate.
Collapse
Affiliation(s)
- Yuan Chen
- Chemistry Department , Rutgers University , 73 Warren Street , Newark , New Jersey 07102 , United States
| | - Jonathan Viereck
- Department of Physics and Astronomy and Laboratory for Surface Modification , Rutgers University , 136 Frelinghuysen Road , Piscataway , New Jersey 08854 , United States
| | - Ryan Harmer
- Chemistry Department , Rutgers University , 73 Warren Street , Newark , New Jersey 07102 , United States
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification , Rutgers University , 136 Frelinghuysen Road , Piscataway , New Jersey 08854 , United States
| | - Robert A Bartynski
- Department of Physics and Astronomy and Laboratory for Surface Modification , Rutgers University , 136 Frelinghuysen Road , Piscataway , New Jersey 08854 , United States
| | - Elena Galoppini
- Chemistry Department , Rutgers University , 73 Warren Street , Newark , New Jersey 07102 , United States
| |
Collapse
|
8
|
Rangan S, Ruggieri C, Bartynski R, Martínez JI, Flores F, Ortega J. Adsorption Geometry and Energy Level Alignment at the PTCDA/TiO2(110) Interface. J Phys Chem B 2017. [DOI: 10.1021/acs.jpcb.7b04227] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sylvie Rangan
- Department of Physics
and Astronomy and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8019, United States
| | - Charles Ruggieri
- Department of Physics
and Astronomy and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8019, United States
| | - Robert Bartynski
- Department of Physics
and Astronomy and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8019, United States
| | - José Ignacio Martínez
- Department of Surfaces, Coatings and Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz
3, ES-28049 Madrid, Spain
| | - Fernando Flores
- Departamento de Física Teórica
de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, ES-28049 Madrid, Spain
| | - José Ortega
- Departamento de Física Teórica
de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, ES-28049 Madrid, Spain
| |
Collapse
|
9
|
Affiliation(s)
- Aleksandra B. Biedron
- Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Eric L. Garfunkel
- Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Edward W. Castner
- Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA
| |
Collapse
|
10
|
Martínez JI, Flores F, Ortega J, Rangan S, Ruggieri CM, Bartynski RA. Unveiling universal trends for the energy level alignment in organic/oxide interfaces. Phys Chem Chem Phys 2017; 19:24412-24420. [DOI: 10.1039/c7cp03853d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Organic/oxide interfaces exhibit an energy-level-alignment universal behaviour when a bias is applied. Coulomb-blockade regime is ruled by the organic electronegativity.
Collapse
Affiliation(s)
- José I. Martínez
- Materials Science Factory
- Dept. Surfaces
- Coatings and Molecular Astrophysics
- Institute of Material Science of Madrid (ICMM-CSIC)
- E-28049 Madrid
| | - Fernando Flores
- Dept. Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC)
- Universidad Autónoma de Madrid
- ES-28049 Madrid
- Spain
| | - José Ortega
- Dept. Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC)
- Universidad Autónoma de Madrid
- ES-28049 Madrid
- Spain
| | - Sylvie Rangan
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers
- The State University of New Jersey
- Piscataway
- USA
| | - Charles M. Ruggieri
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers
- The State University of New Jersey
- Piscataway
- USA
| | - Robert A. Bartynski
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers
- The State University of New Jersey
- Piscataway
- USA
| |
Collapse
|
11
|
Rangan S, Kalyanikar M, Duan J, Liu G, Bartynski RA, Andrei EY, Feldman L, Garfunkel E. Nanoscale Internal Fields in a Biased Graphene-Insulator-Semiconductor Structure. J Phys Chem Lett 2016; 7:3434-3439. [PMID: 27530545 DOI: 10.1021/acs.jpclett.6b01806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Measuring and understanding electric fields in multilayered materials at the nanoscale remains a challenging problem impeding the development of novel devices. At this scale, it is far from obvious that materials can be accurately described by their intrinsic bulk properties, and considerations of the interfaces between layered materials become unavoidable for a complete description of the system's electronic properties. Here, a general approach to the direct measurement of nanoscale internal fields is proposed. Small spot X-ray photoemission was performed on a biased graphene/SiO2/Si structure in order to experimentally determine the potential profile across the system, including discontinuities at the interfaces. Core levels provide a measure of the local potential and are used to reconstruct the potential profile as a function of the depth through the stack. It is found that each interface plays a critical role in establishing the potential across the dielectric, and the origin of the potential discontinuities at each interface is discussed.
Collapse
Affiliation(s)
| | - Malathi Kalyanikar
- Department of Chemistry and Chemical Biology, Rutgers University , 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | | | - Gang Liu
- Institute for Advanced Materials, Devices and Nanotechnology, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States
| | | | | | - Leonard Feldman
- Institute for Advanced Materials, Devices and Nanotechnology, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States
| | - Eric Garfunkel
- Department of Chemistry and Chemical Biology, Rutgers University , 610 Taylor Road, Piscataway, New Jersey 08854, United States
- Institute for Advanced Materials, Devices and Nanotechnology, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States
| |
Collapse
|
12
|
Rangan S, Ruggieri C, Bartynski R, Martínez JI, Flores F, Ortega J. Densely-packed ZnTPPs Monolayer on the Rutile TiO 2(110)-(1×1) Surface: Adsorption Behavior and Energy Level Alignment. J Phys Chem C Nanomater Interfaces 2016; 120:4430-4437. [PMID: 26998188 PMCID: PMC4793616 DOI: 10.1021/acs.jpcc.5b12736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The adsorption of a densely packed Zinc(II) tetraphenylporphyrin monolayer on a rutile TiO2(110)-(1×1) surface has been studied using a combination of experimental and theoretical methods, aimed at analyzing the relation between adsorption behavior and barrier height formation. The adsorption configuration of ZnTPP was determined from scanning tunnel microscopy (STM) imaging, density functional theory (DFT) calculations and STM image simulation. The corresponding energy alignment was experimentally determined from X-ray and UV-photoemission spectroscopies and inverse photoemission spectroscopy. These results were found in good agreement with an appropriately corrected DFT model, pointing to the importance of local bonding and intermolecular interactions in the establishment of barrier heights.
Collapse
Affiliation(s)
- Sylvie Rangan
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (USA)
| | - Charles Ruggieri
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (USA)
| | - Robert Bartynski
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (USA)
| | - José Ignacio Martínez
- Dept. Surfaces, Coatings and Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, E-28049 Madrid (Spain)
| | - Fernando Flores
- Dept. Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, ES-28049 Madrid (Spain)
| | - José Ortega
- Dept. Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, ES-28049 Madrid (Spain)
| |
Collapse
|
13
|
Martínez JI, Flores F, Ortega J, Rangan S, Ruggieri C, Bartynski R. Chemical Interaction, Space-charge Layer and Molecule Charging Energy for a TiO 2/TCNQ Interface. J Phys Chem C Nanomater Interfaces 2015; 119:22086-22091. [PMID: 26877826 PMCID: PMC4746741 DOI: 10.1021/acs.jpcc.5b07045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Three driving forces control the energy level alignment between transition-metal oxides and organic materials: the chemical interaction between the two materials, the organic electronegativity and the possible space charge layer formed in the oxide. This is illustrated in this study by analyzing experimentally and theoretically a paradigmatic case, the TiO2(110) / TCNQ interface: due to the chemical interaction between the two materials, the organic electron affinity level is located below the Fermi energy of the n-doped TiO2. Then, one electron is transferred from the oxide to this level and a space charge layer is developed in the oxide inducing an important increase in the interface dipole and in the oxide work-function.
Collapse
Affiliation(s)
- José I. Martínez
- Dept. Surfaces, Coatings and Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, E-28049 Madrid (Spain)
| | - Fernando Flores
- Dept. Condensed Matter Theoretical Physics and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, ES-28049 Madrid (Spain)
| | - José Ortega
- Dept. Condensed Matter Theoretical Physics and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, ES-28049 Madrid (Spain)
| | - Sylvie Rangan
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (USA)
| | - Charles Ruggieri
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (USA)
| | - Robert Bartynski
- Dept. Physics and Astronomy, and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (USA)
| |
Collapse
|
14
|
Kulkarni P, Kudale A, Arasu K, Lab M, Darby W, Rangan S. Tuberculosis knowledge and awareness in tribal-dominant districts of Jharkhand, India: implications for ACSM. Public Health Action 2015; 4:189-94. [PMID: 26400809 DOI: 10.5588/pha.14.0036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 06/27/2014] [Indexed: 11/10/2022] Open
Abstract
SETTING Forty hard-to-reach villages in the East and West Singhbhum Districts of Jharkhand State, India. OBJECTIVES To document knowledge and awareness of tuberculosis (TB) among the general population, understand gender differences and inform intervention activities for the improvement of TB control programmes in tribal-dominant hard-to-reach areas in India. DESIGN A cross-sectional community-based survey was carried out among 825 respondents using population proportionate sampling. RESULTS Most of the respondents were in the 18-35 years age group, tribal and married; 44% were illiterate. The study shows poor knowledge about TB symptoms, causes, modes of transmission and moderate awareness about government TB services. Correct knowledge about the cause of TB was negligible: half of the respondents reported local liquor as the cause, 61% considered TB as transmissible and one third considered sharing of food as the mode of transmission. Awareness about the availability of free treatment services at government health facilities was high, but awareness about DOTS was low. Significant gender differences were observed in knowledge and awareness levels. CONCLUSION Study findings point to the importance of urgent intensification of culturally congruent and gender-sensitive advocacy, communication and social mobilisation activities.
Collapse
Affiliation(s)
- P Kulkarni
- The Maharashtra Association of Anthropological Sciences-Centre for Health Research and Development, Pune, India
| | - A Kudale
- The Maharashtra Association of Anthropological Sciences-Centre for Health Research and Development, Pune, India
| | - K Arasu
- Alternative for India Development, India, Jamshedpur, India
| | - M Lab
- Target Tuberculosis, Brighton, United Kingdom
| | - W Darby
- Target Tuberculosis, Brighton, United Kingdom
| | - S Rangan
- The Maharashtra Association of Anthropological Sciences-Centre for Health Research and Development, Pune, India
| |
Collapse
|
15
|
Deibert BJ, Zhang J, Smith PF, Chapman KW, Rangan S, Banerjee D, Tan K, Wang H, Pasquale N, Chen F, Lee K, Dismukes GC, Chabal YJ, Li J. Surface and Structural Investigation of a MnO
x
Birnessite‐Type Water Oxidation Catalyst Formed under Photocatalytic Conditions. Chemistry 2015; 21:14218-28. [DOI: 10.1002/chem.201501930] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Benjamin J. Deibert
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Jingming Zhang
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Paul F. Smith
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Karena W. Chapman
- X‐ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (USA)
| | - Sylvie Rangan
- Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Debasis Banerjee
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Kui Tan
- Department of Material Science & Engineering, University of Texas at Dallas, Richardson, TX 75080 (USA)
| | - Hao Wang
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Nicholas Pasquale
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Feng Chen
- Department of Chemistry, Biochemistry, and Physics, Rider University, Lawrenceville, NJ 08648 (USA)
| | - Ki‐Bum Lee
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - G. Charles Dismukes
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
- The Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| | - Yves J. Chabal
- Department of Material Science & Engineering, University of Texas at Dallas, Richardson, TX 75080 (USA)
| | - Jing Li
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA)
| |
Collapse
|
16
|
Bartynski AN, Gruber M, Das S, Rangan S, Mollinger S, Trinh C, Bradforth SE, Vandewal K, Salleo A, Bartynski RA, Bruetting W, Thompson ME. Symmetry-Breaking Charge Transfer in a Zinc Chlorodipyrrin Acceptor for High Open Circuit Voltage Organic Photovoltaics. J Am Chem Soc 2015; 137:5397-405. [DOI: 10.1021/jacs.5b00146] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Mark Gruber
- Institute
for Physics, Augsburg University, 86135 Augsburg, Germany
| | | | - Sylvie Rangan
- Department
of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Sonya Mollinger
- Department
of Materials Science and Engineering, Stanford University, Palo Alto, California 94305, United States
| | | | | | - Koen Vandewal
- Department
of Materials Science and Engineering, Stanford University, Palo Alto, California 94305, United States
| | - Alberto Salleo
- Department
of Materials Science and Engineering, Stanford University, Palo Alto, California 94305, United States
| | - Robert A. Bartynski
- Department
of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | | | | |
Collapse
|
17
|
Ngo KT, Rochford J, Fan H, Batarseh A, Chitre K, Rangan S, Bartynski RA, Galoppini E. Photoelectrochemical properties of porphyrin dyes with a molecular dipole in the linker. Faraday Discuss 2015; 185:497-506. [DOI: 10.1039/c5fd00082c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The electronic properties of three porphyrin–bridge–anchor photosensitizers are reported with (1a, 1e, 3a and 3e) or without (2a and 2e) an intramolecular dipole in the bridge. The presence and orientation of the bridge dipole is hypothesized to influence the photovoltaic properties due to variations in the intrinsic dipole at the semiconductor–molecule interface. Electrochemical studies of the porphyrin–bridge–anchor dyes self-assembled on mesoporous nanoparticle ZrO2 films, show that the presence or direction of the bridge dipole does not have an observable effect on the electronic properties of the porphyrin ring. Subsequent photovoltaic measurements of nanostructured TiO2 semiconductor films in dye sensitized solar cells show a reduced photocurrent for photosensitizers 1a and 3a containing a bridge dipole. However, cooperative increased binding of the 1a + 3a co-sensitized device demonstrates that dye packing overrides any differences due to the presence of the small internal dipole.
Collapse
Affiliation(s)
- Ken T. Ngo
- Department of Chemistry
- University of Massachusetts Boston
- Boston
- USA
| | | | - Hao Fan
- Department of Chemistry
- Rutgers University
- Newark
- USA
| | | | - Keyur Chitre
- Department of Chemistry
- Rutgers University
- Newark
- USA
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification
- Rutgers University
- Piscataway
- USA
| | - Robert A. Bartynski
- Department of Physics and Astronomy and Laboratory for Surface Modification
- Rutgers University
- Piscataway
- USA
| | | |
Collapse
|
18
|
Thorpe R, Rangan S, Whitcomb R, Basaran AC, Saerbeck T, Schuller IK, Bartynski RA. The solid state conversion reaction of epitaxial FeF2(110) thin films with lithium studied by angle-resolved X-ray photoelectron spectroscopy. Phys Chem Chem Phys 2015; 17:15218-25. [DOI: 10.1039/c5cp01150g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An epitaxial FeF2(110) thin film was exposed to Li as a high-purity analogue of a Li-ion battery discharge. The stoichiometry and morphology of the film were then characterized by ARXPS.
Collapse
Affiliation(s)
- Ryan Thorpe
- Department of Physics and Astronomy and Laboratory for Surface Modification
- Rutgers University
- Piscataway
- USA
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification
- Rutgers University
- Piscataway
- USA
| | - Ryan Whitcomb
- Department of Applied Physics
- University of Michigan
- Ann Arbor
- USA
| | - Ali C. Basaran
- Department of Physics and Center for Advanced Nanoscience
- University of California San Diego
- La Jolla
- USA
| | - Thomas Saerbeck
- Department of Physics and Center for Advanced Nanoscience
- University of California San Diego
- La Jolla
- USA
| | - Ivan K. Schuller
- Department of Physics and Center for Advanced Nanoscience
- University of California San Diego
- La Jolla
- USA
| | - Robert A. Bartynski
- Department of Physics and Astronomy and Laboratory for Surface Modification
- Rutgers University
- Piscataway
- USA
| |
Collapse
|
19
|
Neri B, Vannini A, Tassi R, Brugia M, Rangan S, Rediti M, Cerullo C. The efficacy and tolerability of a sunitinib 3-week administration schedule in metastatic renal cell carcinoma patients: report of three cases. Oncol Res 2013; 20:259-64. [PMID: 23581233 DOI: 10.3727/096504013x13589503482851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Sunitinib, an orally multitargeted tyrosine kinase inhibitor and standard first-line treatment for metastatic renal cell carcinoma, is usually administered on a 6-week schedule. Toxicities reported with this drug are usually of moderate grade, which results in good treatment tolerability and patients' compliance. However, in some cases high-grade or prolonged toxicities require temporary treatment interruption or dose adjustment, possibly resulting in reduced treatment efficacy. We describe three cases of metastatic renal cell carcinoma patients (a 53-year-old male, a 70-year-old woman, and a 65-year-old woman) who received a shortened 3-week sunitinib administration schedule, 2 weeks daily administration followed by 1 week of rest (2/1) due to toxicities developed on the classic 6-week schedule, which would have required a temporary treatment interruption or a dose reduction. Treatment was generally well tolerated with manageable toxicities. A 3-week administration schedule of sunitinib may represent a valid alternative for managing toxicity while maintaining the planned dose intensity over a 6-weeks period of time. Sunitinib may thus be administered using a flexible dosing schedule to meet individual patient needs, achieving better tolerability and maintaining significant response to treatment.
Collapse
Affiliation(s)
- B Neri
- Department of Oncology, Centre of Experimental and Clinical Oncology, AOU-Careggi, Florence University, Florence, Italy.
| | | | | | | | | | | | | |
Collapse
|
20
|
Ciftlikli E, Lallo J, Lee EM, Rangan S, Senanayake S, Hinch B. Competing pathways for isocyanate loss from Cu(001) with co-adsorbed oxygen. J Catal 2012. [DOI: 10.1016/j.jcat.2012.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
21
|
Ghosh R, Hara Y, Alibabaei L, Hanson K, Rangan S, Bartynski R, Meyer TJ, Lopez R. Increasing photocurrents in dye sensitized solar cells with tantalum-doped titanium oxide photoanodes obtained by laser ablation. ACS Appl Mater Interfaces 2012; 4:4566-4570. [PMID: 22869506 DOI: 10.1021/am300938g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Laser ablation is employed to produce vertically aligned nanostructured films of undoped and tantalum-doped TiO(2) nanoparticles. Dye-sensitized solar cells using the two different materials are compared. Tantalum-doped TiO(2) photoanode show 65% increase in photocurrents and around 39% improvement in overall cell efficiency compared to undoped TiO(2). Electrochemical impedance spectroscopy, Mott-Schottky analysis and open circuit voltage decay is used to investigate the cause of this improved performance. The enhanced performance is attributed to a combination of increased electron concentration in the semiconductor and a reduced electron recombination rate.
Collapse
Affiliation(s)
- Rudresh Ghosh
- Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina, USA
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Ciftlikli EZ, Lee EYM, Lallo J, Rangan S, Senanayake SD, Hinch BJ. Implementation of new TPD analysis techniques in the evaluation of second order desorption kinetics of cyanogen from Cu(001). Langmuir 2010; 26:18742-18749. [PMID: 21090656 DOI: 10.1021/la102304m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The interactions of cyanide species with a copper (001) surface were studied with temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Adsorbed cyanide species (CN(a)) undergo recombinative desorption evolving molecular cyanogen (C(2)N(2)). As the adsorbed CN species charge upon adsorption, mutually repulsive dipolar interactions lead to a marked desorption energy reduction with increasing CN(a) coverages. Two new TPD analysis approaches were developed, which used only accurately discernible observables and which do not assume constant desorption energies, E(d), and pre-exponential values, ν. These two approaches demonstrated a linear variation of E(d) with instantaneous coverage. The first approach involved an analysis of the variations of desorption peak asymmetry with initial CN coverages. The second quantitative approach utilized only temperatures and intensities of TPD peaks, together with deduced surface coverages at the peak maxima, also as a function of initial surface coverages. Parameters derived from the latter approach were utilized as initial inputs for a comprehensive curve fit analysis technique. Excellent fits for all experimental desorption curves were produced in simulations. The curve fit analysis confirms that the activation energy of desorption of 170-180 kJ/mol at low coverage decreases by up to 14-15 kJ/mol at CN saturation.
Collapse
Affiliation(s)
- Erkan Z Ciftlikli
- Department of Chemistry and Chemical Biology, Rutgers, the State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | | | | | | | | | | |
Collapse
|
23
|
Tassi R, Muto A, Rangan S, Vannini A, Politi L, Neri B. Response and safety of sunitinib in a heavily pre-treated metastatic non-small cell lung carcinoma patient. Anticancer Res 2010; 30:5169-5173. [PMID: 21187507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
BACKGROUND The activity of sunitinib, a multitargeted tyrosine kinase inhibitor with antiangiogenic and antitumor activities, has been explored in several solid malignancies such as breast, lung, prostate and pancreatic cancer. Currently it is approved for the treatment of metastatic renal cell carcinoma and gastrointestinal stromal tumors. Non-small cell lung cancer usually presents at an advanced or metastatic stage at diagnosis. Treatment options are limited for this disease, therefore symptom palliation and patient's quality of life are primary objectives of therapy. CASE REPORT We describe the case of a patient (male, 67 years old) with heavily pre-treated metastatic non-small cell lung carcinoma who received sunitinib according to the following 3-week schedule: 50 mg daily for 2 weeks followed by a 1-week rest. The patient completed six months of therapy achieving a major disease response without high-grade toxicities. CONCLUSION In this case, sunitinib shows promising single-agent activity in pretreated non-small cell lung cancer, with a good toxicity profile and flexible administration schedule.
Collapse
Affiliation(s)
- R Tassi
- Department of Oncology, Centre of Experimental and Clinical Oncology, Florence University, Florence, Italy
| | | | | | | | | | | |
Collapse
|
24
|
Wang Y, Biradar AV, Wang G, Sharma KK, Duncan CT, Rangan S, Asefa T. Controlled Synthesis of Water-Dispersible Faceted Crystalline Copper Nanoparticles and Their Catalytic Properties. Chemistry 2010; 16:10735-43. [DOI: 10.1002/chem.201000354] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
25
|
Gmitter AJ, Badway F, Rangan S, Bartynski RA, Halajko A, Pereira N, Amatucci GG. Formation, dynamics, and implication of solid electrolyte interphase in high voltage reversible conversion fluoride nanocomposites. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b923908a] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
26
|
Neri B, Cipriani G, Grifoni R, Molinara E, Pantaleo P, Rangan S, Vannini A, Tonelli P, Valeri A, Pantalone D, Taddei A, Bechi P. Gemcitabine Plus Irinotecan as First-Line Weekly Therapy in Locally Advanced and/or Metastatic Pancreatic Cancer. Oncol Res 2009; 17:559-64. [DOI: 10.3727/096504009789745610] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
27
|
Neri B, Molinara E, Pantaleo P, Rangan S, Crisci A, Della Melina A, Raugei A, Villari D, Nicitat G. Weekly administration of docetaxel and epirubicin as first-line treatment for hormone-refractory prostate carcinoma. Oncol Res 2009; 17:565-70. [PMID: 19806787 DOI: 10.3727/096504009789745539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Androgen-independent prostate carcinoma (AICP) is one of the tumors that continue to respond poorly to chemotherapy. Recently, protocols based on the use of docetaxel have significantly improved survival for patients in this disease. In other types of neoplastic disease, combined therapy with taxanes and anthracycline derivatives has been shown to produce additive effects in terms of growth inhibition, and superior tolerability when associated with weekly administration schedules. These findings prompted us to examine the tolerability and efficacy of weekly treatment of AICP with docetaxel (DOX) plus epirubicin (EPI). We enrolled 35 chemotherapy-naive men with AICP (mean age 72 years, range 68-77) and normal hepatic, renal, and cardiac function. The chemotherapy protocol provided for the IV administration of DOX (30 mg/m2) and EPI (30 mg/m2) on days 1, 8, and 15 every 28 days. Treatment was continued for 6 months or until disease progression and/or unacceptable toxicity was observed. Serum levels of prostate-specific antigen (PSA) were monitored in all patients, and reductions from baseline values of >50% were considered indicative of positive responses to treatment. Thirty-four patients were included in the analysis of toxicity, and objective responses to treatment were assessed in the 28 patients with measurable lesions. Nineteen patients (56%) experienced PSA reductions of >50% that persisted for more than 4 weeks. The response to therapy was classified as complete in 1 of the 28 patients (4%) with measurable disease (at the lymph node level). Thirteen others (13/28, 46%) had partial responses, in nine (32%) the disease remained unchanged, and progression was observed in the remaining five (18%); overall response rate was 50% (CR + PR). Of the 27 patients with pain at the time of enrollment, 16 (59%) experienced pain reduction during treatment. The median time to disease progression was 11.7 months (95% CI: 7.7-15.7) while the median survival time was 18.7 months (95% CI: 12.3-25.1). During the study, four patients developed grade 3 anemia and leukopenia, which was reversible in all cases. Lower grades of asthenia, nausea, vomiting, diarrhea, and peripheral edema were also observed. There were no cases of cardiotoxic effects. Alopecia was frequent but reversible in all cases. The results of this preliminary study indicate that the combined administration of DOX and EPI for treatment of AIPC is effective and well tolerated. The weekly administration of the drug combination appears to be a promising approach to the treatment of these tumors.
Collapse
Affiliation(s)
- B Neri
- Department of Oncology, Center for Experimental and Clinical Oncology, University of Florence, Florence, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Chaudhuri S, Rangan S, Veyan JF, Muckerman JT, Chabal YJ. Formation and Bonding of Alane Clusters on Al(111) Surfaces Studied by Infrared Absorption Spectroscopy and Theoretical Modeling. J Am Chem Soc 2008; 130:10576-87. [DOI: 10.1021/ja800136k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Santanu Chaudhuri
- Applied Sciences Laboratory and Institute for Shock Physics, Washington State University, Spokane, Washington 99210-1495, Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, and Chemistry Department and Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973-5000
| | - Sylvie Rangan
- Applied Sciences Laboratory and Institute for Shock Physics, Washington State University, Spokane, Washington 99210-1495, Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, and Chemistry Department and Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973-5000
| | - Jean-Francois Veyan
- Applied Sciences Laboratory and Institute for Shock Physics, Washington State University, Spokane, Washington 99210-1495, Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, and Chemistry Department and Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973-5000
| | - James T. Muckerman
- Applied Sciences Laboratory and Institute for Shock Physics, Washington State University, Spokane, Washington 99210-1495, Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, and Chemistry Department and Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973-5000
| | - Yves J. Chabal
- Applied Sciences Laboratory and Institute for Shock Physics, Washington State University, Spokane, Washington 99210-1495, Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, and Chemistry Department and Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973-5000
| |
Collapse
|
29
|
Kelkar-Khambete A, Kielmann K, Pawar S, Porter J, Inamdar V, Datye A, Rangan S. India's Revised National Tuberculosis Control Programme: looking beyond detection and cure. Int J Tuberc Lung Dis 2008; 12:87-92. [PMID: 18173883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
SETTING Pune District, Maharashtra State, India. OBJECTIVES To examine delays experienced by patients in accessing directly observed treatment. DESIGN Data were collected from 117 new sputum-positive patients using a semi-structured interview schedule. RESULTS Patient delays as well as diagnostic and treatment delays, which reflect the performance of a National TB Programme, were minimal. Provider delays, however, contributed significantly to delayed entry into India's Revised National TB Control Programme (RNTCP). Patients had to resort to multiple contacts with providers due to limitations of these providers in diagnosing or directing patients to the RNTCP. Patients who consulted a private provider participating in the public-private mix (PPM) were more likely to be suspected (OR 2.63, 90% CI 1.04-6.64) and referred (OR 6.8, 95%CI 2.08-22.21) to the RNTCP. Once the patients entered the RNTCP, the response of the system was rapid, with diagnosis offered and treatment initiated within on average 7 days. CONCLUSION Interventions aimed at providers to encourage early suspicion and referral to the RNTCP, such as the PPM, are more important in improving patient access to TB care than those focusing on reducing patient delays.
Collapse
Affiliation(s)
- A Kelkar-Khambete
- Maharashtra Association of Anthropological Sciences, Centre for Health Research and Development, Pune, India
| | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Hypothyroidism is a common disorder, which is mainly treated in primary rather than secondary care. Once daily thyroxine replacement restores euthyroidism in most patients; some patients, however, remain hypothyroid despite adequate thyroxine replacement. Non-compliance is the most common cause of lack of response to thyroxine treatment. We describe two cases of primary hypothyroidism in which daily thyroxine treatment did not restore biochemical euthyroidism but once weekly thyroxine treatment was successful. In addition we review the evidence and discuss the differential diagnosis of lack of response to thyroxine treatment. Once weekly thyroxine treatment can be a safe, well-tolerated, and effective therapy for patients with non-compliance.
Collapse
Affiliation(s)
- S Rangan
- Department of Diabetes and Endocrinology, Royal Shrewsbury Hospital, Shrewsbury, UK
| | | | | | | |
Collapse
|
31
|
Abstract
The development of Grave's ophthalmopathy (GO) following radioiodine (RI) treatment for Grave's thyrotoxicosis, though controversial, is well described. The development of ophthalmopathy following RI treatment for toxic nodular goitre is much less recognised. We report a 49 year-old female patient who developed thyrotoxicosis and GO after receiving RI treatment for toxic nodular goitre and we also review the relevant literature.
Collapse
Affiliation(s)
- A A Tahrani
- Royal Shrewsbury Hospital, Mytton Oak Road, Shrewsbury, UK.
| | | | | |
Collapse
|
32
|
Rangan S, Singh PK, Tahrani AA, Varughese GI. Diabetes mellitus and cardiovascular risk factors: more insights revisited. Int J Clin Pract 2007; 61:1055-6. [PMID: 17504368 DOI: 10.1111/j.1742-1241.2007.01370.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
33
|
Rangan S, Bournel F, Gallet JJ, Kubsky S, Le Guen K, Dufour G, Rochet F, Sirotti F, Piaszenski G, Funke R, Kneppe M, Köhler U. Surface Reactions of 3-Butenenitrile on the Si(001)-2 × 1 Surface at Room Temperature. J Phys Chem B 2005; 109:12899-908. [PMID: 16852601 DOI: 10.1021/jp051725y] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using a combination of local -- scanning tunneling microscopy -- and spatially integrated, but chemically sensitive probes -- X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure spectroscopy -- we have examined how 3-butenenitrile reacts with the Si(001)-2 x 1 surface at room temperature. Electron spectroscopies indicate three different nitrogen chemical bonds: a Si-C=N-Si bond, a C=C=N cumulative double bond, and a CN moiety datively bonded to a silicon atom. All molecular imprints detected by scanning tunneling microscopy (STM) involve two adjacent silicon dimers in the same row. The three geometries we propose -- a double di-sigma bonding via the CN and the C=C, a cumulative double bond formation associated with alphaC-H bond dissociation, and a di-sigma vinyl bonding plus a CN datively bonded to a silicon atom -- are all compatible with electron spectroscopies and data. Real-time Auger yield kinetic measurements show that the double di-sigma bonding geometry is unstable when exposed to a continuous flux of 3-butenenitrile molecules, as the Si-C=N-Si unit transforms into a CN moiety. A model is proposed to explain this observation.
Collapse
Affiliation(s)
- Sylvie Rangan
- Laboratoire de Chimie Physique Matière et Rayonnement, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
In February 1999, the Revised National Tuberculosis (TB) Control Programme (RNTCP) was implemented in the city of Mumbai after a pilot phase of 5 years. The city has a population of more than 12 million people and an estimated annual TB incidence of 21,000 cases, 8000 of these being infectious. This paper describes a partnership between the TB programme and a Non Governmental Organization (NGO), which began with a methodological analysis of the problems faced by the programme to help identify other key organizations, who might usefully be involved. The work focussed on "networking" to ensure the optimum use of existing resources. The problems encountered affected all levels of TB control from access to drug supply and treatment. The major issues related to an inadequate public health infrastructure resulting in poor technical and administrative support to field staff. There was confusion over roles of the health personnel in the TB programme and the public health facility, as well as poor technical performance. Partnerships were found to be useful in addressing the following areas: (1) the implementation of an external quality assurance scheme for sputum microscopy through involvement of microbiologists from large hospitals and research organizations; (2) training and capacity strengthening of programme and public health facility staff through innovative training and team building exercises organized by the programme, NGOs and the private sector; (3) development of Information, Education and Communication (IEC) material through partnerships with NGOs, and (4) the involvement of local NGOs and private doctors to increase case finding and to improve access to direct observation of treatment (DOT). The paper discusses the lessons learnt in this process and identifies some of the key issues in urban TB control, for consideration by policy makers.
Collapse
Affiliation(s)
- S Rangan
- Centre for Health Research and Development, 64 Anand Park, Baner Road, Aundh, Pune 411 007, India.
| | | | | | | | | |
Collapse
|
35
|
Uplekar MW, Rangan S, Weiss MG, Ogden J, Borgdorff MW, Hudelson P. Attention to gender issues in tuberculosis control. Int J Tuberc Lung Dis 2001; 5:220-4. [PMID: 11326820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Although a seventy per cent excess of male over female TB cases are reported globally each year, the reasons for this difference are unclear. Generally, women in poor countries confront more barriers than men in accessing health care services. Yet, research is lacking to explain the impact of gender inequalities in access to care on reported sex ratios for TB. A review of the limited available literature and field visits to TB programmes offered insights and suggested a framework to study gender differentials in TB. This paper considers the role of gender at various steps in effective TB care. A research strategy to study and account for gender differences in TB control is proposed.
Collapse
Affiliation(s)
- M W Uplekar
- World Health Organisation, Geneva, Switzerland.
| | | | | | | | | | | |
Collapse
|
36
|
Wattanamano P, Clayton JL, Kopicko JJ, Kissinger P, Elliot S, Jarrott C, Rangan S, Beilke MA. Comparison of three assays for cytomegalovirus detection in AIDS patients at risk for retinitis. J Clin Microbiol 2000; 38:727-32. [PMID: 10655375 PMCID: PMC86188 DOI: 10.1128/jcm.38.2.727-732.2000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to determine the sensitivity and specificity of three different methods of cytomegalovirus (CMV) detection for AIDS patients at risk for CMV retinitis. Patients with CD4(+) counts of <100/microl and negative baseline screening eye examinations were tested for CMV infection by (i) pp65 antigenemia expression in leukocytes, (ii) the Digene Hybrid Capture CMV DNA System, and (iii) the Roche Amplicor Qualitative PCR Test. The incidence of CMV retinitis in our study of 296 patients at the Medical Center of Louisiana-New Orleans HIV Outpatient Clinic was 7. 2 per 100 person-years (a total of 20 episodes in 18 patients from April 1997 to February 1999). Receiver operating characteristic curves were calculated for each assay to determine optimal cutoff points which maximized the sensitivity and specificity of each assay. The sensitivities of the assays compared to the eye examinations were 80% for the pp65 antigenemia assay (cutoff, >0 cell per 1.5 x 10(5) leukocytes), 85% for the Digene assay (cutoff, 1,400 genome copies/ml of whole blood), and 60% for the Amplicor assay. The specificities of the assays were 84, 84, and 87%, respectively. The Digene assay with a cutoff of >/=1,400 genome copies/ml gave optimal sensitivity and specificity and was found to have predictive values equal to those of the more technically cumbersome antigenemia assay.
Collapse
Affiliation(s)
- P Wattanamano
- Section of Infectious Diseases, Tulane University School of Medicine, and Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana 70112, USA
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
Bacterial meningitis is an important cause of acquired sensorineural deafness in childhood. Deafness following meningitis may be progressive. Previous reports have shown deterioration in hearing up to 12 years after the illness. We present two cases of sensorineural deafness following meningitis. Severe to profound sensorineural hearing losses were detected immediately after meningitis in these patients. The hearing subsequently deteriorated in both cases. Deterioration in hearing thresholds occurred 17 years after the illness in one case. In the other patient the hearing got progressively worse three years after meningitis. She subsequently required a cochlear implant.
Collapse
Affiliation(s)
- V Jayarajan
- Department of Audiological Medicine, Royal Surrey County Hospital, Guildford, UK
| | | |
Collapse
|
38
|
Ogden J, Rangan S, Uplekar M, Porter J, Brugha R, Zwi A, Nyheim D. Shifting the paradigm in tuberculosis control: illustrations from India. Int J Tuberc Lung Dis 1999; 3:855-61. [PMID: 10524581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Drawing on literature from India and key contributions from social science, this paper asks and attempts to answer the question 'who is to blame for treatment failures in TB'? Some key lessons emerge: effective tuberculosis control cannot be achieved so long as the disease is considered in isolation from the social processes that maintain it, create the conditions facilitating its spread and act as barriers to care. Insights into the economic and social burdens incurred with a diagnosis of TB are essential to understand why many patients, especially the most disadvantaged, are unable to comply with treatment regimens. TB and health care interventions need to be appropriate to the health service contexts in which they are applied, and sensitive to the competing demands, needs and priorities of people's lives. The paper argues for the need to reorient TB control programmes towards enabling patients to obtain care. The problem of access emerges as central to people's ability to obtain and maintain appropriate therapy. Examples and characteristics of successful non-governmental projects, from which policy makers, programmers and practitioners could learn, are outlined and contrasted with more rigid directly observed treatment approaches. We conclude that treatment failures are not patient failures, and that TB control programmes need to address the social dimensions of TB, and adhere to the principles of good TB care, with the same commitment that is devoted to ensuring patients follow treatment guidelines. We suggest a paradigm shift away from a focus on diseased patients towards enabling health in the community.
Collapse
Affiliation(s)
- J Ogden
- Department of Public Health & Policy, London School of Hygiene & Tropical Medicine, UK.
| | | | | | | | | | | | | |
Collapse
|
39
|
Uplekar M, Juvekar S, Morankar S, Rangan S, Nunn P. Tuberculosis patients and practitioners in private clinics in India. Int J Tuberc Lung Dis 1998; 2:324-9. [PMID: 9559404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
SETTING Rural and urban areas of Maharashtra, a large state in Western India. OBJECTIVE To understand tuberculosis (TB) management practices among private medical practitioners (PPs) and the treatment behaviour of the patients they manage. DESIGN Prospective study of help-seeking patterns and treatment behaviour among 173 pulmonary TB patients diagnosed in private clinics, and the TB management practices of 122 PPs treating these patients. RESULTS The first source of help for 86% of patients was a PP. The diagnostic and treatment practices of PPs were inadequate; 15% did not consider sputum examination to be necessary, and 79 different treatment regimens were prescribed by 105 reporting PPs. Sixty-seven percent of the patients diagnosed in private clinics remained with the private sector, and the rest shifted to public health services within six months of treatment. The treatment adherence rate among the patients in private clinics was 59%. There were discrepancies between the reported management practices of the PPs and what their patients actually followed. CONCLUSION The study identifies and highlights the need to educate PPs and their TB patients, and indicates ways in which PPs could be meaningfully involved in efforts to revitalize the national TB control programme.
Collapse
Affiliation(s)
- M Uplekar
- Foundation for Research in Community Health, Worli, Mumbai, India
| | | | | | | | | |
Collapse
|
40
|
Abstract
Over three quarters of the 8 million registered doctors in India are engaged in private medical practice. In urban and rural areas alike people prefer private doctors to public health services for their health care needs. A majority of patients and those with suspected tuberculosis also report first to private doctors. Nevertheless private doctors seem to be alienated from national efforts towards control of tuberculosis, there being no well-defined role for them in the National Tuberculosis Programme. This study of private doctors practising in the low income areas of a metropolis of India reports on the knowledge of private doctors about diagnosis and treatment of tuberculosis and their awareness and perceptions about the public health services available for tuberculosis control. The study reveals gaps and weaknesses in the private doctors' reported practice of managing lung tuberculosis, the most important and persistent problem of public health concern in India. The need for organized efforts towards involving private doctors in disease control programmes wherein their curative functions could contribute significantly is stressed.
Collapse
Affiliation(s)
- M W Uplekar
- Foundation for Research in Community Health, Worli, Bombay, India
| | | |
Collapse
|
41
|
Rangan S, Uplekar M. Community health awareness among recent medical graduates of Bombay. Natl Med J India 1993; 6:60-4. [PMID: 8477210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Since Independence in 1947, the need for reorientation of our western-style, hospital-based, urban-oriented medical education has been well recognized and much discussed but little action has been taken to make it more community-based. Against a background of 40 years of debate, we conducted a study of 342 medical graduates commencing their internship training in one government and two municipal medical colleges to assess the effects of medical education on them. METHODS A questionnaire was administered to examine recent interns' awareness of some aspects of community health, their perceptions of the concept of Primary Health Care and their knowledge of rational prescriptions for minor ailments and for major illnesses of public health importance. RESULTS We found a lack of basic health information among recent medical graduates, an apathy towards matters of public health importance, and gaps in their knowledge of curative care and rational prescribing. CONCLUSION We suggest that there is a need not only to effect changes in the curriculum but also to assess whether these changes might lead to the making of doctors more suited to work in our villages.
Collapse
Affiliation(s)
- S Rangan
- Foundation for Research in Community Health, Maharashtra, India
| | | |
Collapse
|
42
|
Abstract
The occurrence of adult T-cell leukemia-lymphoma in two New Orleans patients, one native-born, the other originally from Honduras, is reported. Both exhibited an unusual feature. One patient was diagnosed following an atypical episode of sinusitis and demonstrated lymphomatous infiltration of the nasopharynx. A second patient had a fulminant course complicated by severe diarrhea and was found to have both tumor involvement and cytomegalovirus inclusions in the colon. Both had high titers of antibodies to HTLV-I. A cell line with T-lymphocyte characteristics was established from the peripheral blood of the first patient. Such studies may help better establish the clinical course, detection, and epidemiologic features of this difficult disease.
Collapse
|