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Olshanetsky EB, Gusev GM, Levin AD, Kvon ZD, Mikhailov NN. Multifractal Conductance Fluctuations of Helical Edge States. Phys Rev Lett 2023; 131:076301. [PMID: 37656853 DOI: 10.1103/physrevlett.131.076301] [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] [Received: 03/10/2023] [Accepted: 07/23/2023] [Indexed: 09/03/2023]
Abstract
Two-dimensional topological insulators are characterized by the bulk gap and one-dimensional helical states running along the edges. The theory predicts the topological protection of the helical transport from coherent backscattering. However, the unexpected deviations of the conductance from the quantized value and localization of the helical modes are generally observed in long samples. Moreover, at millikelvin temperatures significant mesoscopic fluctuations are developed as a function of the electron energy. Here we report the results of an experimental study of the transport in a HgTe quantum well with an inverted energy spectrum that reveal a multifractality of the conductance fluctuations in the helical edge state dominated transport regime. We attribute observed multifractality to mesoscopic fluctuations of the electron wave function or local density of states at the spin quantum Hall transition. We have shown that the mesoscopic two-dimensional topological insulator provides a highly tunable experimental system in which to explore the physics of the Anderson transition between topological states.
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Affiliation(s)
- E B Olshanetsky
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - G M Gusev
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, SP, Brazil
| | - A D Levin
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, SP, Brazil
| | - Z D Kvon
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - N N Mikhailov
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
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2
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Tran TT, Jung J, Garcia L, DeShields JB, Cerrato DC, Penner MH, Tomasino E, Levin AD, Zhao Y. Impact of functional spray coatings on smoke volatile phenol compounds and Pinot noir grape growth. J Food Sci 2023; 88:367-380. [PMID: 36533941 DOI: 10.1111/1750-3841.16435] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/18/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
The frequency and intensity of wildfires have been increasing over the last 50 years and negatively impacted the wine industry. Previous methods of smoke mitigation during grape processing have shown little impact in reducing smoke taint in wines. Therefore, a novel method of using edible spray coatings for vineyard application was developed to help prevent volatile smoke phenol uptake in wine grapes. Four cellulose nanofiber-based coating suspensions incorporated with chitosan and/or β-cyclodextrin were evaluated. Films derived from the coating suspensions were exposed to volatile phenols found in wildfire smoke (guaiacol, 4-methyl guaiacol, m-cresol, o-cresol, p-cresol, syringol, and 4-methyl syringol) and evaluated with ultraviolet-visible spectroscopy where the results indicated that the coatings could uptake smoke phenols in varying degrees. The coatings were also applied in a vineyard at three different application times during grape growth: pea-sized, pre-bunch closure, and both at pea-sized and pre-bunch closure. The results showed that the application time did not have a significant (p < 0.05) effect on berry size, weight, °Brix, pH, or titratable acidity. The type of coating, time of application and washing were found to impact the number of volatile phenols in the grapes after a smoke event. Results from this study indicated that edible coatings could help mitigate smoke uptake in wine grapes without sacrificing the growth and key composition parameters of wine grapes. PRACTICAL APPLICATION: This research provides a novel spray coating that can be applied to wine grapes in the vineyard to potentially mitigate volatile smoke compounds in wine grapes without impacting fruit growth and key compositional parameters of wine grapes, thus maintaining high quality of wines for consumers. Results from this study can also be potentially applied to other agricultural commodities to solve the issues caused by the wildfire smoke.
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Affiliation(s)
- Trung T Tran
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Jooyeoun Jung
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Lindsay Garcia
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Joseph B DeShields
- Department of Horticulture, Oregon State University, Corvallis, Oregon, USA.,Southern Oregon Research and Extension Center, Oregon State University, Central Point, Oregon, USA
| | - D Cole Cerrato
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Michael H Penner
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Elizabeth Tomasino
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Alexander D Levin
- Department of Horticulture, Oregon State University, Corvallis, Oregon, USA.,Southern Oregon Research and Extension Center, Oregon State University, Central Point, Oregon, USA
| | - Yanyun Zhao
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
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Gusev GM, Levin AD, Kozlov DA, Kvon ZD, Mikhailov NN. Quantum Transport of Dirac Fermions in HgTe Gapless Quantum Wells. Nanomaterials (Basel) 2022; 12:nano12122047. [PMID: 35745386 PMCID: PMC9229369 DOI: 10.3390/nano12122047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 01/27/2023]
Abstract
We study the transport properties of HgTe quantum wells with critical well thickness, where the band gap is closed and the low energy spectrum is described by a single Dirac cone. In this work, we examined both macroscopic and micron-sized (mesoscopic) samples. In micron-sized samples, we observe a magnetic-field-induced quantized resistance (~h/2e) at Landau filling factor ν=0, corresponding to the formation of helical edge states centered at the charge neutrality point (CNP). In macroscopic samples, the resistance near a zero Landau level (LL) reveals strong oscillations, which we attribute to scattering between the edge ν=0 state and bulk ν≠0 hole LL. We provide a model taking an empirical approach to construct a LL diagram based on a reservoir scenario, formed by the heavy holes.
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Affiliation(s)
- Gennady M. Gusev
- Instituto de Física, Universidade de São Paulo, Sao Paulo 135960-170, Brazil;
- Correspondence: ; Tel.: +55-11-3091-6878
| | - Alexander D. Levin
- Instituto de Física, Universidade de São Paulo, Sao Paulo 135960-170, Brazil;
| | - Dmitry A. Kozlov
- Institute of Semiconductor Physics, 630090 Novosibirsk, Russia; (D.A.K.); (Z.D.K.); (N.N.M.)
| | - Ze D. Kvon
- Institute of Semiconductor Physics, 630090 Novosibirsk, Russia; (D.A.K.); (Z.D.K.); (N.N.M.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Nikolay N. Mikhailov
- Institute of Semiconductor Physics, 630090 Novosibirsk, Russia; (D.A.K.); (Z.D.K.); (N.N.M.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
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Levin AD, KC AN. Water Deficits Do Not Improve Fruit Quality in Grapevine Red Blotch Virus-Infected Grapevines ( Vitis vinifera L.). Front Plant Sci 2020; 11:1292. [PMID: 32973850 PMCID: PMC7472797 DOI: 10.3389/fpls.2020.01292] [Citation(s) in RCA: 2] [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] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/07/2020] [Indexed: 06/11/2023]
Abstract
Although deficit irrigation is used to improve fruit quality in healthy grapevines, it can potentially amplify negative effects of viral disease and reduce fruit quality in Grapevine Red Blotch Virus (GRBV) infected grapevines. Therefore, a 2-year field experiment was conducted to understand the interaction between GRBV infection and water deficits on disease development and vine physiology. Well-watered (WW) vines were irrigated at 100% of estimated crop evapotranspiration (ETc), while water deficit (WD) vines received water at 66 and 50% ETc in 2017 and 2018, respectively. Healthy (GRBV-) and infected (GRBV+) vines were confirmed by PCR assays. There were no significant effects of water deficits on foliar symptom onset in either year, but more severe water deficits in 2018 resulted in a more rapid symptom progression. GRBV+ vines had a higher Ψstem compared to GRBV- vines, but the effects of virus only appeared post-veraison and corresponded to decreased leaf gas exchange. In general, vine vegetative and reproductive growth were not reduced in GRBV+ vines. Yields were highest in WW/GRBV+ vines due to larger clusters containing larger berries. Consistent treatment effects on berry primary chemistry were limited to sugars, with no interactions between factors. Water deficits were able to somewhat increase berry anthocyanin concentration in GRBV+ fruit, but the effects were dependent on year. By comparison, virus status and water deficits interacted on skin tannins concentration such that they were decreased in WD/GRBV+ vines, but increased in WD/GRBV- vines. Water deficits had no effect on seed phenolics, with only virus status having a significant diminution. Although keeping GRBV+ vines well-watered may mitigate some of the negative effects of GRBD, these results suggest that water deficits will not improve overall fruit quality in GRBV+ vines. Ultimately, the control of fruit ripening imparted by GRBV infection seems to be stronger than abiotic control imparted by water deficits.
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Affiliation(s)
- Alexander D. Levin
- Department of Horticulture, Oregon State University, Corvallis, OR, United States
- Southern Oregon Research and Extension Center, Oregon State University, Central Point, OR, United States
| | - Achala N. KC
- Southern Oregon Research and Extension Center, Oregon State University, Central Point, OR, United States
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States
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Levy BT, Hoffman RM, Daly JM, Xu Y, Crockett SD, Shokar NK, Dawson JD, Reuland DS, Zuckerman MJ, Levin AD. Diagnostic Performance of Four Fecal Immunochemical Tests for Detecting Advanced Colorectal Neoplasia: Preliminary Results. Cancer Epidemiol Biomarkers Prev 2019. [DOI: 10.1158/1055-9965.epi-19-0085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
Screening programs based on fecal blood testing have been shown in randomized controlled trials to reduce colorectal cancer incidence and mortality. Professional organizations highly recommend screening average-risk patients with fecal immunochemical testing (FIT). Many patients find these stool tests more acceptable than colonoscopy and stool testing may be the preferred option for areas with limited endoscopic resources. However, the diagnostic performance of FIT testing, particularly for CLIA-waived point-of-care (POC) tests, has not been well studied. Purpose: We are comparing the diagnostic accuracy of 4 FIT tests, one automated (AUTO) and 3 POC, for detecting advanced neoplasia (advanced adenomas and carcinomas) using colonoscopy as a gold standard. Methods. We are enrolling subjects ages 50 to 85 at 3 academic medical centers in Iowa, Texas, and North Carolina who were scheduled for a screening or surveillance colonoscopy. Each subject completed 4 different FIT tests on a single stool specimen. Based on colonoscopy results, we calculated sensitivity, specificity, and predictive values. We used PROC GLIMMIX models in SAS to compare sensitivity and specificity across the different tests, accounting for the within-patient correlation. Results: We currently have 641 subjects who completed FIT and colonoscopy. Mean age is 61.2 (±7.5) years, 63% women, 63% non-Hispanic white, and 31% Hispanic. We found advanced neoplasia, including 5 carcinomas, in 68 subjects. The sensitivities for detecting these neoplasia were 3%, 22%, 28%, and 16% (AUTO), respectively. Corresponding positive predictive values were 18%, 21%, 33%, and 24% (AUTO). Specificities were 97%, 89%, 90%, and 94% (AUTO), respectively, and corresponding negative predictive values were 89%, 91%, 92%, and 90% (AUTO). We found statistically significant differences in sensitivity (P < 0.01) and specificity (P < 0.01) across tests. Conclusions: Early data suggest that FIT products may vary in their sensitivity and specificity for detecting advanced colorectal neoplasia. This variability could have important impacts on the effectiveness of efforts to limit the burden of colorectal cancer by increasing population-based screening rates through fecal blood testing.
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Levin AD, Williams LE, Matthews MA. A continuum of stomatal responses to water deficits among 17 wine grape cultivars (Vitis vinifera). Funct Plant Biol 2019; 47:11-25. [PMID: 31615618 DOI: 10.1071/fp19073] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/19/2019] [Indexed: 06/10/2023]
Abstract
Vitis vinifera L. cultivars have been previously classified as isohydric, near-isohydric, anisohydric or isohydrodynamic, depending on the study. To test the hypothesis that V. vinifera cultivars' stomatal behaviour can be separated into distinct classes, 17 cultivars grown in a replicated field trial were subjected to three irrigation treatments to manipulate vine water status across multiple years. Predawn (ΨPD) and midday (Ψl) leaf water potential and midday stomatal conductance (gs) were measured regularly throughout several seasons. The relationship of gs to Ψl was best modelled as a sigmoidal function and maximum stomatal conductance (gmax), water status at the onset of stomatal closure (Ψl95), sensitivity of closure (gsensitivity) and water status at the end of closure (Ψl25) were compared. There were no significant differences in gmax among cultivars. Cultivar-specific responses of gs to Ψl were broadly distributed along a continuum based on the relationship between Ψl95 and gsensitivity. Season-long cultivar mean Ψl values were positively related to Ψl25. In general, cultivars responded similarly to one another at high and low water status, but their stomatal behaviour differed at moderate water deficits. The results show that V. vinifera cultivars possess both iso- and anisohydric stomatal behaviours that depend on the intensity of water deficits, and call into question previous classifications assuming a single behaviour.
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Affiliation(s)
- Alexander D Levin
- Department of Horticulture, Oregon State University, Corvallis, OR 97331, USA; and Southern Oregon Research and Extension Center, 569 Hanley Road., Central Point, OR 97502, USA; and Corresponding author.
| | - Larry E Williams
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; and Kearney Agricultural Research and Extension Center, 9240 S. Riverbend Avenue., Parlier, CA 93648, USA
| | - Mark A Matthews
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
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Levin AD, Momtaz ZS, Gusev GM, Raichev OE, Bakarov AK. Microwave-Induced Magneto-Oscillations and Signatures of Zero-Resistance States in Phonon-Drag Voltage in Two-Dimensional Electron Systems. Phys Rev Lett 2015; 115:206801. [PMID: 26613460 DOI: 10.1103/physrevlett.115.206801] [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] [Received: 05/07/2015] [Indexed: 06/05/2023]
Abstract
We observe the phonon-drag voltage oscillations correlating with the resistance oscillations under microwave irradiation in a two-dimensional electron gas in perpendicular magnetic field. This phenomenon is explained by the influence of dissipative resistivity modified by microwaves on the phonon-drag voltage perpendicular to the phonon flux. When the lowest-order resistance minima evolve into zero-resistance states, the phonon-drag voltage demonstrates sharp features suggesting that current domains associated with these states can exist in the absence of external dc driving.
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Affiliation(s)
- A D Levin
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, Brazil
| | - Z S Momtaz
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, Brazil
| | - G M Gusev
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, Brazil
| | - O E Raichev
- Institute of Semiconductor Physics, NAS of Ukraine, Prospekt Nauki 41, 03028 Kyiv, Ukraine
| | - A K Bakarov
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
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8
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Olshanetsky EB, Kvon ZD, Gusev GM, Levin AD, Raichev OE, Mikhailov NN, Dvoretsky SA. Persistence of a two-dimensional topological insulator state in wide HgTe quantum wells. Phys Rev Lett 2015; 114:126802. [PMID: 25860765 DOI: 10.1103/physrevlett.114.126802] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Indexed: 06/04/2023]
Abstract
Our experimental studies of electron transport in wide (14 nm) HgTe quantum wells confirm the persistence of a two-dimensional topological insulator state reported previously for narrower wells, where it was justified theoretically. Comparison of local and nonlocal resistance measurements indicate edge state transport in the samples of about 1 mm size at temperatures below 1 K. Temperature dependence of the resistances suggests an insulating gap of the order of a few meV. In samples with sizes smaller than 10 μm a quasiballistic transport via the edge states is observed.
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Affiliation(s)
- E B Olshanetsky
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
| | - Z D Kvon
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - G M Gusev
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, São Paulo, Brazil
| | - A D Levin
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, São Paulo, Brazil
| | - O E Raichev
- Institute of Semiconductor Physics, NAS of Ukraine, Prospekt Nauki 41, 03028 Kyiv, Ukraine
| | - N N Mikhailov
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
| | - S A Dvoretsky
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
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Chekanov AV, Baranova OA, Levin AD, Solov'eva ÉI, Fedin AI, Kazarinov KD. [Study of the influence of gold nanoparticles on activation of human blood neutrophils]. Biofizika 2013; 58:495-500. [PMID: 24159819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Activation of neutrophils in the presence of gold nanoparticles is accompanied by the formation of free radical peroxidation products recording the flash of chemiluminescence. The basis for the activation mechanism has its origins most likely in the influence of the gold particles on the surface membrane potential of neutrophils. Investigation of changes in the fluorescence intensity of the negatively charged ANS probe on the surface of model membranes by adding different concentrations of gold nanoparticles indicates the change in the membrane surface charge density that can cause cell activation.
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10
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Gusev GM, Levin AD, Kvon ZD, Mikhailov NN, Dvoretsky SA. Quantum hall effect in n-p-n and n-2D topological insulator-n junctions. Phys Rev Lett 2013; 110:076805. [PMID: 25166393 DOI: 10.1103/physrevlett.110.076805] [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] [Received: 10/11/2012] [Indexed: 06/03/2023]
Abstract
We have studied quantized transport in HgTe wells with inverted band structure corresponding to the two-dimensional topological insulator phase (2D TI) with locally controlled density allowing n-p-n and n-2D TI-n junctions. The resistance reveals the fractional plateau 2h/e(2) in the n-p-n regime in the presence of the strong perpendicular magnetic field. We found that in the n-2D TI-n regime the plateaux in resistance in not universal and results from the edge state equilibration at the interface between chiral and helical edge modes. We provided the simple model describing the resistance quantization in n-2D TI-n regime.
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Affiliation(s)
- G M Gusev
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, SP, Brazil
| | - A D Levin
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, SP, Brazil
| | - Z D Kvon
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
| | - N N Mikhailov
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
| | - S A Dvoretsky
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
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11
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Gusev GM, Olshanetsky EB, Kvon ZD, Levin AD, Mikhailov NN, Dvoretsky SA. Nonlocal transport near charge neutrality point in a two-dimensional electron-hole system. Phys Rev Lett 2012; 108:226804. [PMID: 23003639 DOI: 10.1103/physrevlett.108.226804] [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] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Indexed: 06/01/2023]
Abstract
Nonlocal resistance is studied in a two-dimensional system with a simultaneous presence of electrons and holes in a 20 nm HgTe quantum well. A large nonlocal electric response is found near the charge neutrality point in the presence of a perpendicular magnetic field. We attribute the observed nonlocality to the edge state transport via counterpropagating chiral modes similar to the quantum spin Hall effect at a zero magnetic field and graphene near a Landau filling factor ν=0.
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Affiliation(s)
- G M Gusev
- Instituto de Física da Universidade de São Paulo, 135960-170, São Paulo, SP, Brazil
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Abstract
BACKGROUND Local drug delivery has transformed medicine, yet it remains unclear how drug efficacy depends on physicochemical properties and delivery kinetics. Most therapies seek to prolong release, yet recent studies demonstrate sustained clinical benefit following local bolus endovascular delivery. OBJECTIVES The purpose of the current study was to examine interplay between drug dose, diffusion and binding in determining tissue penetration and effect. METHODS We introduce a quantitative framework that balances dose, saturable binding and diffusion, and measured the specific binding parameters of drugs to target tissues. RESULTS Model reduction techniques augmented by numerical simulations revealed that impact of saturable binding on drug transport and retention is determined by the magnitude of a binding potential, B(p), ratio of binding capacity to product of equilibrium dissociation constant and accessible tissue volume fraction. At low B(p) (< 1), drugs are predominantly free and transport scales linearly with concentration. At high B(p) (> 40), drug transport exhibits threshold dependence on applied surface concentration. CONCLUSIONS In this paradigm, drugs and antibodies with large B(p) penetrate faster and deeper into tissues when presented at high concentrations. Threshold dependence of tissue transport on applied surface concentration of paclitaxel and rapamycin may explain threshold dose dependence of in vivo biological efficacy of these drugs.
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Affiliation(s)
- A R Tzafriri
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Ivanov AA, Kalinin NL, Gromakovskaia ET, Levin AD, Podrez EA. [Immunochemical properties of immunoglobulin G conjugated with dextran]. Biull Eksp Biol Med 1988; 106:78-80. [PMID: 2456794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Antigen-binding activity and effector functions of immunoglobulin G from horse and rabbit sera have been investigated, using hemagglutination, kinetic immune lysis, immune lysis in microplates and rosette-forming test with peritoneal mononuclear cells of mice, after their conjugation with dextran, MW 35-50 kD. The formation of conjugates of two types has been demonstrated: protein-dextran and protein-dextran-protein. It has been revealed that protein-dextran-protein conjugates have high specific antigen-binding activity, as compared to native IgG from rabbit sera specific for SRBC, while interactions with the complement system and Fc receptors is depressed.
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Batanov GV, Stepanov VS, Trifonov SI, Levin AD. [Evaluation of the biological action of UHF radiation on immunity indices]. Gig Sanit 1987:35-7. [PMID: 3692189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Ivanov AA, Kalinin NL, Ulanova AM, Boĭko MI, Levin AD. [Anaphylactogenicity of dextran-conjugated serum globulins]. Biull Eksp Biol Med 1987; 103:719-22. [PMID: 2439145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Active anaphylaxis in 238 guinea-pigs has revealed a decrease in the anaphylactogenic activity of horse blood serum IgG conjugates with dextran and of serum treated with dextran according to Diaferm method. The conjugates were used for a challenge injection. The sensitizing activity of dextran-conjugated proteins was higher than that of native proteins. The effect was most pronounced with 150,000 D dextran used as a matrix. A lower increase in sensitizing protein activity and a decrease in anaphylactogenic activity were achieved with dextran matrix of the molecular weight of 35-50 D and protein/dextran ratio from 1:6 to 1:9.
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Petrov RV, Gus'kova AK, Danilova NB, Dozmorov IM, Levin AD. [Comparative characteristics of the changes in blood lymphocyte subpopulations in chronic lympholeukemia]. Gematol Transfuziol 1984; 29:21-8. [PMID: 6397394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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17
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Aleksandrova NP, Il'in SG, Levin AD. [Rheological properties of the blood in acute venous thrombosis]. Kardiologiia 1978; 18:136-8. [PMID: 691955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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