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Ullah S, Syed NM, Gang T, Noor RS, Ahmad S, Waqas MM, Shah AN, Ullah S. Recent global warming as a proximate cause of deforestation and forest degradation in northern Pakistan. PLoS One 2022; 17:e0260607. [PMID: 35061707 PMCID: PMC8782284 DOI: 10.1371/journal.pone.0260607] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 11/12/2021] [Indexed: 02/05/2023] Open
Abstract
Instrumental climatological records such as weather stations data of northern areas of Pakistan are not sufficient to assess the forest extreme events reliably. To understand the past climatic variability, tree ring width based climatic reconstruction is the best alternative to trace climate variability that goes back in time. Quercus Incana is the most sensitive species to drought and climatic variation in northern Pakistan. However, very little research quantifies the rate of ongoing climatic changes. A total of 65 tree cores were collected from two sites to understand the radial growth of Q. Incana to extreme drought events. The radial growth is mainly affected by high temperatures during May-July. In addition, radial growth exhibits a positive correlation with February-June precipitation while it is negatively correlated with the September precipitation. The radial growth decrease, particularly in harsh climatic conditions. The reconstructed tree ring record was strongly coherent with the May-June self-calibrated Palmer drought severity index (scPDSI) and reliable in reconstructing drought variability for the period 1750-2014. During the past 264 years, wet periods were found during 1980-2010, 1812-1836, and 1754-1760, while dry periods were found during 1896-1922, 1864-1876, and 1784-1788. Our reconstruction explains 39.8% of the scPDSI variance. The extreme drought and wet years we arrived at were in close agreement with the drought and wet periods that occurred in northern Pakistan. Wavelet analysis revealed drought variability at periodicities of 2.2-2.5, 3.3, 3-4, 16.7, 16.8, and 68-78.8 years. Hence it is concluded that deforestation and forest degradation rate increased with extreme drought and wet years. Overall, the variation of drought in northern Pakistan seems to have been affected due to El Nino south oscillation, Pacific decadal oscillation, or Atlantic multi-decadal oscillations.
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Affiliation(s)
- Saif Ullah
- College of Economics & Management, Northeast Forestry University, Harbin, China
| | - Nizami Moazzam Syed
- Department of Forestry & Wildlife, Management, University of Haripur, Haripur, Pakistan
| | - Tian Gang
- College of Economics & Management, Northeast Forestry University, Harbin, China
| | - Rana Shahzad Noor
- Department of Agriculture, Biological, Environment and Energy Engineering, College of Engineering, Northeast Agricultural University, Harbin, China
- Faculty of Agricultural Engineering and Technology, PMAS-Arid Agriculture University, Rawalpindi, Pakistan
| | - Sarir Ahmad
- Department of Forestry & Wildlife, Management, University of Haripur, Haripur, Pakistan
| | - Muhammad Mohsin Waqas
- Department of Agricultural Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, Punjab, Pakistan
| | - Adnan Noor Shah
- Department of Agricultural Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, Punjab, Pakistan
| | - Sami Ullah
- Department of Chemistry, College of Science, King Khalid University, Abha, Saudi Arabia
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Xu HM, Zhang KY, Bai SP, Ding XM, Wang JP, Peng HW, Xuan Y, Su ZW, Gang T, Zeng QF. Dietary resistant potato starch improves growth performance and feather development in Pekin ducks fed a low phosphorus diet. Poult Sci 2021; 100:100947. [PMID: 33518311 PMCID: PMC7936172 DOI: 10.1016/j.psj.2020.12.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/10/2020] [Accepted: 12/15/2020] [Indexed: 11/28/2022] Open
Abstract
This study investigated whether dietary resistant potato starch (RPS) inclusion could ameliorate the negative impact of a low nonphytate phosphorus (nPP) diet on growth performance, feather growth, feather follicles (FF) development, and carcass traits by improving nutrient utilization and cecal microbiome fermentation capacity in Pekin ducks. The experiment was performed with a 2 × 2 randomized block design with 2 levels of RPS (0 or 12%) and 2 levels of nPP (low or normal, low: 0.22% at 1–14 d and 0.18% at 15–35 d of age; normal: 0.40% at 1–14 d and 0.35% at 15–35 d of age) for a total of 4 treatments, each with 8 replicate pens per treatment of 12 birds per pen. As regards growth performance and carcass traits, RPS inclusion markedly increased (P < 0.05) BW of 14 and 35 d, BWG and FI of 1–14 d, 15–35 d, and 1–35 d as well as abdominal fat and breast meat percentage of 35 d in ducks fed low nPP diets; moreover, RSP inclusion significantly reduced (P < 0.05) mortality in ducks fed low nPP diets. As regards feather growth and follicles development of 35 d, RPS inclusion significantly increased (P < 0.05) the fourth primary feather length, absolute feather weight, and the density of primary FF in the back skin in ducks fed low nPP diets. In regard to nutrition utilization, RPS supplementation significantly increased (P < 0.05) the availability of DM, CP, and energy, as well as dietary AME at 35 d of age in ducks fed low nPP diets. However, RPS supplementation had no effect (P > 0.05) on the concentration of cecal short-chain fatty acids and the activities of cecal phytase and cellulase in ducks fed low nPP diets. These results indicate that RPS can improve nutrient availability to ameliorate the negative effects on performance and feather development caused by a low nPP diet in Pekin ducks.
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Affiliation(s)
- H M Xu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - K Y Zhang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - S P Bai
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - X M Ding
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - J P Wang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - H W Peng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - Y Xuan
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - Z W Su
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - T Gang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130
| | - Q F Zeng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition of, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130.
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Mueller F, Schouten RN, Brauns M, Gang T, Lim WH, Lai NS, Dzurak AS, van der Wiel WG, Zwanenburg FA. Erratum: "Printed circuit board metal powder filters for low electron temperatures" [Rev. Sci. Instrum. 84, 044706 (2013)]. Rev Sci Instrum 2016; 87:079903. [PMID: 27475615 DOI: 10.1063/1.4959151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Filipp Mueller
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, AE 7500, The Netherlands
| | - Raymond N Schouten
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, GA 2600, The Netherlands
| | - Matthias Brauns
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, AE 7500, The Netherlands
| | - Tian Gang
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, AE 7500, The Netherlands
| | - Wee Han Lim
- ARC Centre of Excellence for Quantum Computation and Communication Technology, The University of New South Wales, Sydney 2052, Australia
| | - Nai Shyan Lai
- ARC Centre of Excellence for Quantum Computation and Communication Technology, The University of New South Wales, Sydney 2052, Australia
| | - Andrew S Dzurak
- ARC Centre of Excellence for Quantum Computation and Communication Technology, The University of New South Wales, Sydney 2052, Australia
| | - Wilfred G van der Wiel
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, AE 7500, The Netherlands
| | - Floris A Zwanenburg
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, AE 7500, The Netherlands
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Ataç D, Gang T, Yilmaz MD, Bose SK, Lenferink ATM, Otto C, de Jong MP, Huskens J, van der Wiel WG. Tuning the Kondo effect in thin Au films by depositing a thin layer of Au on molecular spin-dopants. Nanotechnology 2013; 24:375204. [PMID: 23975183 DOI: 10.1088/0957-4484/24/37/375204] [Citation(s) in RCA: 1] [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: 06/02/2023]
Abstract
We report on the tuning of the Kondo effect in thin Au films containing a monolayer of cobalt(II) terpyridine complexes by altering the ligand structure around the Co(2+) ions by depositing a thin Au capping layer on top of the monolayer on Au by magnetron sputtering (more energetic) and e-beam evaporation (softer). We show that the Kondo effect is slightly enhanced with respect to that of the uncapped film when the cap is deposited by evaporation, and significantly enhanced when magnetron sputtering is used. The Kondo temperature (TK) increases from 3 to 4.2/6.2 K for the evaporated/sputtered caps. X-ray absorption spectroscopy and surface-enhanced Raman spectroscopy investigation showed that the organic ligands remain intact upon Au e-beam evaporation; however, sputtering inflicts significant change in the Co(2+) electronic environment. The location of the monolayer-on the surface or embedded in the film-has a small effect. However, the damage of Co-N bonds induced by sputtering has a drastic effect on the increase of the impurity-electron interaction. This opens up the way for tuning of the magnetic impurity states, e.g. spin quantum number, binding energy with respect to the host Fermi energy, and overlap via the ligand structure around the ions.
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Affiliation(s)
- D Ataç
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
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Mueller F, Schouten RN, Brauns M, Gang T, Lim WH, Lai NS, Dzurak AS, van der Wiel WG, Zwanenburg FA. Printed circuit board metal powder filters for low electron temperatures. Rev Sci Instrum 2013; 84:044706. [PMID: 23635219 DOI: 10.1063/1.4802875] [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] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the characterisation of printed circuit boards (PCB) metal powder filters and their influence on the effective electron temperature which is as low as 22 mK for a quantum dot in a silicon MOSFET structure in a dilution refrigerator. We investigate the attenuation behaviour (10 MHz-20 GHz) of filter made of four metal powders with a grain size below 50 μm. The room-temperature attenuation of a stainless steel powder filter is more than 80 dB at frequencies above 1.5 GHz. In all metal powder filters, the attenuation increases with temperature. Compared to classical powder filters, the design presented here is much less laborious to fabricate and specifically the copper powder PCB-filters deliver an equal or even better performance than their classical counterparts.
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Affiliation(s)
- Filipp Mueller
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
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Veldhorst M, Snelder M, Hoek M, Gang T, Guduru VK, Wang XL, Zeitler U, van der Wiel WG, Golubov AA, Hilgenkamp H, Brinkman A. Josephson supercurrent through a topological insulator surface state. Nat Mater 2012; 11:417-421. [PMID: 22344327 DOI: 10.1038/nmat3255] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 01/25/2012] [Indexed: 05/31/2023]
Abstract
The long-sought yet elusive Majorana fermion is predicted to arise from a combination of a superconductor and a topological insulator. An essential step in the hunt for this emergent particle is the unequivocal observation of supercurrent in a topological phase. Here, direct evidence for Josephson supercurrents in superconductor (Nb)-topological insulator (Bi(2)Te(3))-superconductor electron-beam fabricated junctions is provided by the observation of clear Shapiro steps under microwave irradiation, and a Fraunhofer-type dependence of the critical current on magnetic field. Shubnikov-de Haas oscillations in magnetic fields up to 30 T reveal a topologically non-trivial two-dimensional surface state. This surface state is attributed to mediate the ballistic Josephson current despite the fact that the normal state transport is dominated by diffusive bulk conductivity. The lateral Nb-Bi(2)Te(3)-Nb junctions hence provide prospects for the realization of devices supporting Majorana fermions.
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Gang T, Yilmaz MD, Ataç D, Bose SK, Strambini E, Velders AH, de Jong MP, Huskens J, van der Wiel WG. Tunable doping of a metal with molecular spins. Nat Nanotechnol 2012; 7:232-236. [PMID: 22306840 DOI: 10.1038/nnano.2012.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/23/2011] [Indexed: 05/31/2023]
Abstract
The mutual interaction of localized magnetic moments and their interplay with itinerant conduction electrons in a solid are central to many phenomena in condensed-matter physics, including magnetic ordering and related many-body phenomena such as the Kondo effect, the Ruderman-Kittel-Kasuya-Yoshida interaction and carrier-induced ferromagnetism in diluted magnetic semiconductors. The strength and relative importance of these spin phenomena are determined by the magnitude and sign of the exchange interaction between the localized magnetic moments and also by the mean distance between them. Detailed studies of such systems require the ability to tune the mean distance between the localized magnetic moments, which is equivalent to being able to control the concentration of magnetic impurities in the host material. Here, we present a method for doping a gold film with localized magnetic moments that involves depositing a monolayer of a metal terpyridine complex onto the film. The metal ions in the complexes can be cobalt or zinc, and the concentration of magnetic impurities in the gold film can be controlled by varying the relative amounts of cobalt complexes (which carry a spin) and zinc complexes (which have zero spin). Kondo and weak localization measurements demonstrate that the magnetic impurity concentration can be systematically varied up to ∼800 ppm without any sign of inter-impurity interaction. Moreover, we find no evidence for the unwanted clustering that is often produced when using alternative methods.
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Affiliation(s)
- T Gang
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands
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Abstract
Controlled assembly of ferromagnetic nanoparticles on surfaces is of crucial importance for a range of spintronic and data storage applications. Here, we present a novel method for assembling monolayers of ferromagnetic FePt nanoparticles on silicon oxide substrates using "click chemistry". Reaction of alkyne-functionalized FePt nanoparticles with azide-terminated self-assembled monolayers (SAMs), on silicon oxide, leads to the irreversible attachment of magnetic nanoparticles to the surface via triazole linkers. Based on this covalent interaction, well-packed monolayers of FePt nanoparticles were prepared and nanoparticle patterns are generated on surfaces via microcontact printing (μCP).
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Affiliation(s)
- Sachin Kinge
- Laboratory of Supramolecular Chemistry and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
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Gang T, Yildirim O, Kinge S, Duan X, Reinhoudt DN, Blank DHA, Rijnders G, van der Wiel WG, Huskens J. Nano-patterned monolayer and multilayer structures of FePtAu nanoparticles on aluminum oxide prepared by nanoimprint lithography and nanomolding in capillaries. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm11559f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yildirim O, Gang T, Kinge S, Reinhoudt DN, Blank DH, van der Wiel WG, Rijnders G, Huskens J. Monolayer-directed assembly and magnetic properties of FePt nanoparticles on patterned aluminum oxide. Int J Mol Sci 2010; 11:1162-79. [PMID: 20480007 PMCID: PMC2869229 DOI: 10.3390/iijms11031162] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 03/03/2010] [Indexed: 11/23/2022] Open
Abstract
FePt nanoparticles (NPs) were assembled on aluminum oxide substrates, and their ferromagnetic properties were studied before and after thermal annealing. For the first time, phosph(on)ates were used as an adsorbate to form self-assembled monolayers (SAMs) on alumina to direct the assembly of NPs onto the surface. The Al2O3 substrates were functionalized with aminobutylphosphonic acid (ABP) or phosphonoundecanoic acid (PNDA) SAMs or with poly(ethyleneimine) (PEI) as a reference. FePt NPs assembled on all of these monolayers, but much less on unmodified Al2O3, which shows that ligand exchange at the NPs is the most likely mechanism of attachment. Proper modification of the Al2O3 surface and controlling the immersion time of the modified Al2O3 substrates into the FePt NP solution resulted in FePt NPs assembly with controlled NP density. Alumina substrates were patterned by microcontact printing using aminobutylphosphonic acid as the ink, allowing local NP assembly. Thermal annealing under reducing conditions (96%N2/4%H2) led to a phase change of the FePt NPs from the disordered FCC phase to the ordered FCT phase. This resulted in ferromagnetic behavior at room temperature. Such a process can potentially be applied in the fabrication of spintronic devices.
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Affiliation(s)
- Oktay Yildirim
- Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
- Inorganic Materials Science, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Tian Gang
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Sachin Kinge
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
- Supramolecular Chemistry & Technology, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - David N. Reinhoudt
- Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
- Supramolecular Chemistry & Technology, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Dave H.A. Blank
- Inorganic Materials Science, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Wilfred G. van der Wiel
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
- Authors to whom correspondence should be addressed; E-Mails:
(W.G.W.);
(G. R.);
(J.H.); Tel.: +31-53-4892873 (W.G.W.); +31-53-4892618 (G.R.); +31-53-4892995 (J.H.); Fax: +31-53-4893343 (W.G.W.); +31-53-4893595 (G.R.); +31-53-4894645 (J.H.)
| | - Guus Rijnders
- Inorganic Materials Science, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
- Authors to whom correspondence should be addressed; E-Mails:
(W.G.W.);
(G. R.);
(J.H.); Tel.: +31-53-4892873 (W.G.W.); +31-53-4892618 (G.R.); +31-53-4892995 (J.H.); Fax: +31-53-4893343 (W.G.W.); +31-53-4893595 (G.R.); +31-53-4894645 (J.H.)
| | - Jurriaan Huskens
- Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
- Authors to whom correspondence should be addressed; E-Mails:
(W.G.W.);
(G. R.);
(J.H.); Tel.: +31-53-4892873 (W.G.W.); +31-53-4892618 (G.R.); +31-53-4892995 (J.H.); Fax: +31-53-4893343 (W.G.W.); +31-53-4893595 (G.R.); +31-53-4894645 (J.H.)
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Kinge S, Gang T, Naber WJM, Boschker H, Rijnders G, Reinhoudt DN, van der Wiel WG. Low-temperature solution synthesis of chemically functional ferromagnetic FePtAu nanoparticles. Nano Lett 2009; 9:3220-3224. [PMID: 19691342 DOI: 10.1021/nl901465s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Magnetic nanoparticles are of great scientific and technological interest. The application of ferromagnetic nanoparticles for high-density data storage has great potential, but energy efficient synthesis of uniform, isolated, and patternable nanoparticles that remain ferromagnetic at room temperature is not trivial. Here, we present a low-temperature solution synthesis method for FePtAu nanoparticles that addresses all those issues and therefore can be regarded as an important step toward applications. We show that the onset of the chemically ordered face-centered tetragonal (L1(0)) phase is obtained for thermal annealing temperatures as low as 150 degrees C. Large uniaxial magnetic anisotropy (10(7) erg/cm(3)) and a high long-range order parameter have been obtained. Our low-temperature solution annealing leaves the organic ligands intact, so that the possibility for postanneal monolayer formation and chemically assisted patterning on a surface is maintained.
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Affiliation(s)
- Sachin Kinge
- Strategic Research Orientation NanoElectronics, Laboratory of Supramolecular Chemistry and Technology, Faculty of Science and Technology, and Inorganic Materials Science Group, Faculty of Science and Technology, MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
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Hu R, Yin CL, Wu N, Cui GY, Meng H, Wu XG, Luo HS, Gang T, Hu S, Shi J, Lin JK, Feng H. Traditional Chinese herb Dihuang Yinzi (DY) plays neuroprotective and anti-dementia role in rats of ischemic brain injury. J Ethnopharmacol 2009; 121:444-450. [PMID: 19000752 DOI: 10.1016/j.jep.2008.09.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 08/21/2008] [Accepted: 09/30/2008] [Indexed: 05/27/2023]
Abstract
AIM OF THE STUDY Traditional Chinese herb Dihuang Yinzi (DY) is well known to treat neurological diseases by traditional Chinese medical practitioners. This study is to elucidate its neuroprotective and anti-dementia role in ischemic brain injury. MATERIALS AND METHODS The effects of DY on the pathohistological changes, lactate dehydrogenase (LDH) release, Morris water maze task, expression of synaptophysin (SYP) and extracellular signal-regulated protein kinase (ERK) of hippocampi of rats with ischemic brain injury were investigated. RESULTS This study showed that DY not only significantly decreased the number of TUNEL-positive cells but also reduced the LDH release of hippocampus of model rat. Morris water maze test showed that the ability of learning and memory of rats dramatically impaired after ischemic brain injury. However, DY ameliorated the impairment of learning and memory of ischemic rats. Furthermore, western blotting and immunohistochemical data showed that the expression of extracellular regulated protein and synaptophysin, which correlates with synaptic formation and function, decreased after ischemic insult. However, DY inhibited the reduction of ERK an SYP expression in a dose-dependent way. CONCLUSION These results suggest that DY possesses neuroprotective and anti-dementia properties, at least in part, by preventing the loss of neural cells and synapses in ischemic brain injury.
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Affiliation(s)
- Rong Hu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Gaotanyan 29, Chongqing 400038, People's Republic of China
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Ludden MJW, Ling XY, Gang T, Bula WP, Gardeniers HJGE, Reinhoudt DN, Huskens J. Multivalent binding of small guest molecules and proteins to molecular printboards inside microchannels. Chemistry 2008; 14:136-42. [PMID: 18000928 DOI: 10.1002/chem.200701250] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [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: 12/13/2022]
Abstract
Beta-Cyclodextrin (beta-CD) monolayers have been immobilized in microchannels. The host-guest interactions on the beta-CD monolayers inside the channels were comparable to the interactions on beta-CD monolayers on planar surfaces, and a divalent fluorescent guest attached with a comparable binding strength. Proteins were attached to these monolayers inside microchannels in a selective manner by employing a strategy that uses streptavidin and orthogonal linker molecules. The design of the chip, which involved a large channel that splits into four smaller channels, allowed the channels to be addressed separately and led to the selective immobilization of antibodies. Experiments with labeled antibodies showed the selective immobilization of these antibodies in the separate channels.
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Affiliation(s)
- Manon J W Ludden
- Molecular Nanofabrication group MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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Chen Z, Gang T, Wang Y, Chen X, Guan C, Zhang J, Sun Z, Zhang K, Zhao B, Yang B. A simple method of preparing Ag nanoparticles coated silica colloidal crystals and polymer-Ag nanoparticles composite macroporous films. Colloids Surf A Physicochem Eng Asp 2006. [DOI: 10.1016/j.colsurfa.2005.11.010] [Citation(s) in RCA: 11] [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: 11/30/2022]
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Chen Z, Chen X, Zheng L, Gang T, Cui T, Zhang K, Yang B. A simple and controlled method of preparing uniform Ag midnanoparticles on Tollens-soaked silica spheres. J Colloid Interface Sci 2005; 285:146-51. [PMID: 15797407 DOI: 10.1016/j.jcis.2004.11.056] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Accepted: 11/24/2004] [Indexed: 10/25/2022]
Abstract
Ag midnanoparticles (midnanoparticles are those particles whose diameters are in the range from 20 to 80 nm) with average size of 30-50 nm and tunable packing densities were formed on the surface of preformed Tollens-soaked silica spheres by a simple and controlled method. The process mainly involved two steps. In the first step the absorption of Ag(NH3)2(+) ions occurred on the silica spheres and in the second step Ag(NH3)2(+) ions on the silica spheres were reduced to Ag midnanoparticles in the presence of glucose solution. The amount of Ag midnanoparticles on the silica spheres could easily be tuned by varying the washing times in the process of preparing the Tollens-soaked silica spheres. The washing process also effectively avoided the reduction of Ag(NH3)2(+) ions and the nucleation of Ag particles in solution and easily produced more uniform Ag midnanoparticles on the silica spheres. Attributing to the uniform Ag midnanoparticles, the Ag midnanoparticle-coated silica spheres show unique optical properties in the UV-vis absorption spectra. The resulting Ag midnanoparticle-coated silica spheres were characterized with transmission electron microscopy, UV-vis-IR recording spectrophotometry, and X-ray photoelectron spectroscopy.
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Affiliation(s)
- Zhimin Chen
- Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China
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Zhilin Q, Gang H, Benkun M, Gang T. Spatiotemporally periodic patterns in symmetrically coupled map lattices. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1994; 50:163-170. [PMID: 9961953 DOI: 10.1103/physreve.50.163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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