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1.
Zhonghua Wei Chang Wai Ke Za Zhi ; 27(1): 47-53, 2024 Jan 25.
Artículo en Chino | MEDLINE | ID: mdl-38262900

RESUMEN

Objective: In this study, we aimed to compare the short-term safety of two digestive tract reconstruction techniques, laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis, following radical resection of Siewert Type II adenocarcinoma of the esophagogastric junction. Methods: In this retrospective cohort study, we analyzed relevant clinical data of 139 patients who had undergone radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. These included 89 patients treated at the First Affiliated Hospital of Air Force Medical University from November 2021 to July 2023, 36 patients treated at the First Affiliated Hospital of Xi'an Jiaotong University from December 2020 to June 2021, and 14 patients treated at the Yuncheng Central Hospital in Shanxi Province from September 2021 to November 2022. The group consisted of 107 men (77.0%) and 32 women (23.0%) of mean age 62.5±9.3 years. Forty-eight patients underwent laparoscopic total abdominal overlap anastomosis (overlap group), and 91 laparoscopic-assisted end-to-side anastomosis (end-to-side group). Clinical data, surgical information, pathological findings, postoperative recovery, and related complications were compared between the two groups. Results: There were no significant differences in general clinical data between the overlap and end-to-side anastomosis groups (all P>0.05), indicating comparability. There was no significant difference in operation time (267.2±60.1 minutes vs. 262.8±70.6 minutes, t=0.370, P=0.712). However, the intraoperative blood loss in the overlap group (100 [50, 100] mL) was significantly lower compared to the end-to-side group (100[50, 175] mL, Z=2.776, P=0.005). Compared to the end-to-side group, longer distances between the tumor and distal resection margin proximal(1.7±1.0 cm vs. 1.3±0.9 cm, t=2.487, P=0.014) and the tumor and distal resection margin (9.5±2.9 cm vs. 7.9±3.5 cm, t=2.667, P=0.009) were achieved in the overlap group. Compared with the end-to-side group, the overlap group achieved significantly earlier postoperative ambulation (1.0 [1.0, 2.0] days vs. 2.0 [1.0, 3.0] days, Z=3.117, P=0.002), earlier time to first drink (4.7±2.6 days vs. 6.2±3.0 days, t=2.851, P=0.005), and earlier time to first meal (6.0±2.7 days vs. 7.1±3.0 days, t=2.170, P=0.032). However, the hospitalization costs were higher in the overlap group (113, 105.5±37, 766.3) yuan vs. (97, 250.2±27, 746.9) yuan; this difference is significant (t=2.818, P=0.006). There were no significant differences between the two groups in postoperative hospital stay, total number of lymph nodes cleared, or time to first postoperative flatus (all P>0.05). The incidence of surgery-related complications was 22.9%(11/48) in the overlap group and 19.8% (18/91) in the end-to-side group; this difference is not significant (χ²=0.187, P=0.831). Further comparison of complications using the Clavien-Dindo classification also showed no significant differences (Z=0.406, P=0.685). Conclusions: Both laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis are feasible for radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. Laparoscopic total abdominal overlap anastomosis achieves longer proximal and distal resection margins and better postoperative recovery; however, end-to-side anastomosis is more cost-effective.


Asunto(s)
Adenocarcinoma , Neoplasias Esofágicas , Márgenes de Escisión , Masculino , Humanos , Femenino , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Anastomosis Quirúrgica , Unión Esofagogástrica
2.
Zhonghua Zhong Liu Za Zhi ; 42(1): 50-54, 2020 Jan 23.
Artículo en Chino | MEDLINE | ID: mdl-32023769

RESUMEN

Objective: To explore the clinical features and risk factors of hepatic injury due to immune checkpoint inhibitors (CPI) therapy in malignant tumor. Methods: Data of 112 patients (64 men and 48 women) who received CPI between January 2016 and March 2019 in Chinese Academy of Medical Sciences and Peking Union Medical College Shenzhen Hospital, and Huazhong University of Science and Techology Union Shenzhen Hospital were retrospectively collected. The median age of these patients was 60 years. Results: Hepatic adverse events were observed in 30 patients out of 112 patients (26.8%). Among them, the incidence of grade 3-5 hepatic adverse events were 7.14% (8/112). The median time of hepatic adverse event occurrence was 3 weeks (2-30) after undergoing therapy. The results of univariate and multivariate analyses showed that liver cancer was attributed to the CPI induced hepatitis (P<0.05). Patients with severe hepatic injury got almost complete resolution after receiving methlprednisolone for 4 to 6 weeks. Conclusion: Live cancer is the risk factor of CPI-related hepatic adverse events.


Asunto(s)
Inmunoterapia , Hepatopatías , Neoplasias , Femenino , Humanos , Inmunoterapia/efectos adversos , Hígado , Hepatopatías/etiología , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Estudios Retrospectivos , Factores de Riesgo
3.
Sci Rep ; 6: 38670, 2016 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-27934924

RESUMEN

In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells.

4.
Sci Rep ; 6: 28118, 2016 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-27301609

RESUMEN

Novel behavior has been observed at the interface of LaAlO3/SrTiO3 heterostructures such as two dimensional metallic conductivity, magnetic scattering and superconductivity. However, both the origins and quantification of such behavior have been complicated due to an interplay of mechanical, chemical and electronic factors. Here chemical and strain profiles near the interface of LaAlO3/SrTiO3 heterostructures are correlated. Conductive and insulating samples have been processed, with thicknesses respectively above and below the commonly admitted conductivity threshold. The intermixing and structural distortions within the crystal lattice have been quantitatively measured near the interface with a depth resolution of unit cell size. A strong link between intermixing and structural distortions at such interfaces is highlighted: intermixing was more pronounced in the hetero-couple with conductive interface, whereas in-plane compressive strains extended deeper within the substrate of the hetero-couple with the insulating interface. This allows a better understanding of the interface local mechanisms leading to the conductivity.

5.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 30(9): 702-706;711, 2016 May 05.
Artículo en Chino | MEDLINE | ID: mdl-29771017

RESUMEN

Objective: To observe the effect of normal saline with intranasal corticosteroids in the treatment of allergic rhinitis(AR).Method:Two hundred and seventy-three outpatients with severe persistent allergic rhinitis were participated in this study.All patients were randomly divided into three groups, and were treated for 12 weeks using three different therapies, respectively. Symptom assessment of each patient were performed before treatment, 4 weeks, 8 weeks, and 12 weeks after treatment, respectively. The content of symptom assessment includes visual analogue scale, rhinoconjunctivitis quality of life questionnaire, symptoms scores and endoscopy examination scores.Result:Efficacy of intranasal corticosteroids combined with normal saline nasal irrigation in the treatment of AR is better than that of intranasal corticosteroids only, and is almost equivalent to intranasal corticosteroids combined with antihistamines.Conclusion:Long-term application of intranasal corticosteroids in combination with normal saline irrigation can effectively control and mitigate symptoms of severe persistent AR patients, and improve the patient's quality of life. This combination therapy is a better choice for the patient who is not satisfied with the single use of intranasal corticosteroids.


Asunto(s)
Glucocorticoides/administración & dosificación , Lavado Nasal (Proceso) , Rinitis Alérgica/terapia , Cloruro de Sodio/administración & dosificación , Administración Intranasal , Administración Oral , Quimioterapia Combinada , Humanos , Mucosa Nasal/metabolismo , Calidad de Vida , Resultado del Tratamiento
6.
Genet Mol Res ; 14(3): 10273-80, 2015 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-26345965

RESUMEN

This study investigated the effects of stable transfection of the exogenous wild-type DCC gene on growth of the human colorectal carcinoma cell line SW1116 in vitro. The DCC gene was amplified from normal human colon tissue by reverse transcription-polymerase chain reaction and used to construct a recombinant expression plasmid, pcDNA3.1(+)-DCC. DCC-negative SW1116 cells were transfected with pcDNA3.1(+)-DCC. Cell viability was tested by the methyl thiazolyl tetrazolium (MTT) assay. Immunofluorescence staining was used to determine the effects of pcDNA3.1(+)-DCC on carcinoembryonic antigen (CEA) expression in transfected cells. The number of cells in the population transfected with pcDNA3.1(+)-DCC was lower than in that transfected with the control pcDNA3.1(+) plasmid or in normal cells (t1 = 3.645, P1 < 0.05, t2 = 3.132, P2 < 0.05) at 3-6 days after transfection, and the proliferation rate of pcDNA3.1(+)-DCC transfected cells was also lower (t1 = 2.134, P2 < 0.05; t2 = 2.736, P2 < 0.05). The total viability of pcDNA3.1(+)-DCC transfected cells was lower than that of normal cells (t1 = 3.053, P1 < 0.05) at 2-6 days after transfection, and of control-transfected cells (t2 = 2.816, P2 < 0.05) after 2, 4, 5, and 6 days. The population of pcDNA3.1(+)-DCC transfected colored of green fluorescent cells and their fluorescent intensities were lower than those of control-transfected and normal cells. Therefore, the transfected DCC gene can suppress cell proliferation and lead to downregulation of CEA expression in SW1116 cells, which might weaken its infiltration and metastasis abilities.


Asunto(s)
Antígeno Carcinoembrionario/metabolismo , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Receptores de Superficie Celular/genética , Proteínas Supresoras de Tumor/genética , Recuento de Células , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular/genética , Receptor DCC , Técnica del Anticuerpo Fluorescente , Humanos , Plásmidos/metabolismo , Receptores de Superficie Celular/metabolismo , Transfección , Proteínas Supresoras de Tumor/metabolismo
7.
Water Sci Technol ; 71(12): 1806-14, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26067500

RESUMEN

The Dragon lake diversion channel (DLDC) is the only river that recharges Dragon Lake, an artificial lake in China. This paper examines the main factors influencing water quality by investigating point source and non-point source pollutants along the main route. Based on the complicated system of rivers and desilting basins, a three-dimensional water quality model using environmental fluid dynamics code (EFDC) was developed. The model of DLDC was calibrated and verified using observed data. The error ranges of river water level, total phosphorus, total nitrogen and chemical oxygen demand were within 5%, 10%, 16% and 20%, respectively, all of which meet the precision requirement. The model was employed to predict the concentrations of pollutants in the main stream under current pollution loads within a year and a flood lasting for 24 hours. The results revealed that the main pollution sources that influence the water quality of waterways were the point sources followed by the non-point pollution sources. Water quality improved when large water quantities were delivered and this trend can be described as dilution. The water quality of the Dongfeng main channel meets the requirement; however, the water quality of the Dongfeng River is somewhat poor, and the water quality of the Wei River is seriously contaminated. To address these problems, we suggest that the Dongfeng River and Wei River adopt a culvert under its riverbeds.


Asunto(s)
Monitoreo del Ambiente/métodos , Lagos/química , Modelos Teóricos , Ríos/química , Contaminantes Químicos del Agua/análisis , Análisis de la Demanda Biológica de Oxígeno , China , Nitrógeno/análisis , Fósforo/análisis , Calidad del Agua
8.
Chem Commun (Camb) ; 50(93): 14647-50, 2014 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-25314259

RESUMEN

LiFSI and LiTFSI are combined to form a binary-salt electrolyte with higher ionic conductivity and lower viscosity for a Li-S battery. A high capacity and stable cycle performance of the sulfur-based composite with high sulfur content are realized in the electrolyte, accompanied simultaneously by the homogeneous lithium deposition on the anode.

9.
J Chem Phys ; 140(17): 174707, 2014 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-24811655

RESUMEN

We investigate the electronic properties of bilayer MoS2 exposed to an external electric field by using first-principles calculations. It is found that a larger interlayer distance, referring to that by standard density functional theory (DFT) with respect to that by DFT with empirical dispersion corrections, makes indirect-direct band gap transition possible by electric control. We show that external electric field effectively manipulates the valence band contrast between the K- and Γ-valleys by forming built-in electric dipole fields, which realizes an indirect-direct transition before a semiconductor-metal transition happens. Our results provide a novel efficient access to tune the electronic properties of two-dimensional layered materials.

10.
Phys Rev Lett ; 110(24): 249702, 2013 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-25165971

RESUMEN

A reply to the comment by A. Yu. Kuntsevich and V. M. Pudalov.

11.
Water Sci Technol ; 65(8): 1454-60, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22466593

RESUMEN

To study the spatial and temporal trends of water quality in the Yuqiao Reservoir (Ji County, Tianjin) in China, water quality data for ten physical and chemical parameters from three monitoring stations (S1, S2 and S3) was collected from 1989 to 2007 and from an other three stations (S4, S5 and S6) during the period of 1999-2007. A one-way ANOVA was employed to evaluate the spatial variation of water quality for each station. The results showed that there were statistically significant spatial differences for most water quality parameters except temperature and dissolved oxygen in the entire reservoir, and the concentrations of most parameters were higher in the uppermost part of the reservoir. The temporal trend study was conducted using the Seasonal-Kendall's test. The results revealed improving trends of water quality from 1989 to 2007, including a reduction of total phosphorous, temperature and biochemical oxygen demand and an increase of dissolved oxygen. High N:P ratios, ranging from 52.61 to 78.75, indicated that the reservoir was a phosphorous-limited environment. This study suggests long-term spatial and temporal variations of water quality in the Yuqiao Reservoir, which could be informative for water quality managers and scientists.


Asunto(s)
Calidad del Agua , Abastecimiento de Agua , China , Geografía , Factores de Tiempo
12.
Phys Rev Lett ; 108(10): 106404, 2012 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-22463433

RESUMEN

We present the transport and capacitance measurements of 10 nm wide GaAs quantum wells with hole densities around the critical point of the 2D metal-insulator transition (critical density p(c) down to 0.8 × 10(10)/cm2, r(s) ∼ 36). For metallic hole density p(c) < p < p(c) + 0.15 × 10(10)/cm2, a reentrant insulating phase (RIP) is observed between the ν = 1 quantum Hall state and the zero-field metallic state and it is attributed to the formation of pinned Wigner crystal. Through studying the evolution of the RIP versus 2D hole density, we show that the RIP is incompressible and continuously connected to the zero-field insulator, suggesting a similar origin for these two phases.

13.
Phys Chem Chem Phys ; 14(4): 1339-42, 2012 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-22160103

RESUMEN

Nickel phosphide-embedded graphene, prepared by the hydrothermal reaction of red phosphorus, nickel chloride, and graphene oxide in a mixture of ethylene glycol-water, is investigated as the counter electrode of DSSCs. It is demonstrated that the DSSC with the nickel phosphide-embedded graphene as the new counter electrode presents an excellent performance competing with that of the Pt electrode.

14.
Ir J Med Sci ; 180(4): 865-72, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21748440

RESUMEN

INTRODUCTION: Prostate cancer cells can switch from an androgen-dependent state to an androgen-independent state after a continuous androgen ablation therapy. However, the molecular mechanisms underlying this switch are still unclear. Therefore, we explored the change in androgen receptor (AR)-related gene expression during this transition in a novel cell model. MATERIAL AND METHODS: Prostate cancer cells were continuously treated with competitive androgen receptor inhibitor hydroxyflutamide for 1.5 years, which yielded an flutamide-insensitive LNCaP subline, LNCaP-flu, as confirmed by MTT assays, flow cytometry, and electron microscopy. We analyzed the differences in gene expression in LNCaP-flu cells and LNCaP cells using gene chips and follow-up RT-PCR. RESULTS: Over 2,428 genes were differentially expressed between these cell lines: 1,194 were down-regulated and 1,234 were up-regulated. Three genes in particular were considered related to the androgen-dependent transition: NCOR1, TIF2 (NCOA2), and ARA70 (NCOA4). There were no apparent changes in expression of the androgen receptor or prostate-specific antigen. CONCLUSION: ARs and associated coregulators play a central role in the flutamide-insensitive transition of prostate cancer cells. Although AR expression does not change during this transition, the change in AR coregulators may be a critical factor in the development of antiandrogen insensitivity.


Asunto(s)
Resistencia a Antineoplásicos/genética , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , ARN Mensajero/metabolismo , Antagonistas de Andrógenos/uso terapéutico , Flutamida/análogos & derivados , Flutamida/uso terapéutico , Expresión Génica , Perfilación de la Expresión Génica , Humanos , Masculino , Co-Represor 1 de Receptor Nuclear/genética , Coactivador 2 del Receptor Nuclear/genética , Coactivadores de Receptor Nuclear/genética , Neoplasias de la Próstata/tratamiento farmacológico , Células Tumorales Cultivadas
15.
Chem Commun (Camb) ; (44): 6720-2, 2009 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-19885457

RESUMEN

TiN nanotube arrays, prepared by the anodization of metallic Ti foil substrate and subsequent simple nitridation in an ammonia atmosphere, were investigated as low-cost counter electrodes in dye-sensitized solar cells for the first time. It is found that the highly ordered TiN nanotube arrays on the metallic Ti foil substrate show an excellent performance, comparable with typical Pt counter electrodes.


Asunto(s)
Fuentes Generadoras de Energía , Nanotubos/química , Energía Solar , Titanio/química , Colorantes , Electrodos , Nanotecnología/métodos
16.
Phytomedicine ; 15(5): 386-8, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-17977703

RESUMEN

The EtOAc extract of Rabdosia coetsa showed angiotensin-converting enzyme (ACE) inhibitory activity. Bioassay-guided isolation of this extract yielded ethyl caffeate (1), rosmarinic acid (2) and methyl rosmarinate (3), which inhibited ACE activity by 32.42%, 55.19% and 39.50% respectively, at the concentration of 10 microg/ml.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Isodon/química , Extractos Vegetales/farmacología , Animales , Ácidos Cafeicos/química , Ácidos Cafeicos/farmacología , Cinamatos/química , Cinamatos/farmacología , Depsidos/química , Depsidos/farmacología , Pulmón/enzimología , Peptidil-Dipeptidasa A/efectos de los fármacos , Peptidil-Dipeptidasa A/aislamiento & purificación , Peptidil-Dipeptidasa A/metabolismo , Extractos Vegetales/química , Conejos , Ácido Rosmarínico
17.
J Phys Chem B ; 110(30): 14754-60, 2006 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-16869583

RESUMEN

Spinel Zn2SnO4 particles with the cubic shape are prepared via a hydrothermal reaction under mild conditions. The hydrothermal conditions, such as alkaline concentration, reaction temperature, and duration time, have an important influence on the product structure and the performance of the electrode prepared with the product. The optimized product is cube-shaped Zn2SnO4 crystalline, which is prepared with 0.4 M of NaOH solution at 200 degrees C for 24 h. These cube-shaped Zn2SnO4 particles with the spinel structure exhibit a large electrochemical capacity of 988 mA h/g and a relatively good capacity retention as anode materials for Li-ion battery. The structures of the as-prepared product and specimens taken from the electrodes after charging-discharging cycles are analyzed by X-ray diffraction, scanning electron microscopy, and transition electron microscopy techniques. In particular, it is found for the first time that the spinel Zn2SnO4 structure exists to a great extent after the first cycle and contributes to the extremely high reversible capacity during the following cycles.

18.
J Phys Chem B ; 110(4): 1614-20, 2006 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-16471724

RESUMEN

Praseodymium hydroxide nanorods were synthesized by a two-step approach: First, metallic praseodymium was used to form praseodymium chloride, which reacted subsequently with KOH solution to produce praseodymium hydroxide. In the second step the hydroxide was treated with a concentrated alkaline solution at 180 degrees C for 45 h, yielding nanorods as shown by the scanning and transmission electron microscopy images. The results of X-ray diffraction and energy-dispersive X-ray spectroscopy experiments indicate that these nanorods are pure praseodymium hydroxide with a hexagonal structure, which can be converted into praseodymium oxide (Pr6O11) nanorods of a face-centered cubic structure after calcination at 600 degrees C for 2 h in air. Gold was loaded on the praseodymium oxide nanorods using HAuCl4 as the gold source, and NaBH4 was used to reduce the gold species to metallic nanoparticles with sizes of 8-12 nm on the nanorod surface. These Au/Pr6O11 nanorods exhibit superior catalytic activity for CO oxidation.

19.
J Am Chem Soc ; 127(18): 6730-6, 2005 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-15869295

RESUMEN

Titanate nanofibers of various sizes and layered structure were prepared from inorganic titanium compounds by hydrothermal reactions. These fibers are different from "refractory" mineral substances because of their dimension, morphology, and significant large ratio of surface to volume, and, surprisingly, they are highly reactive. We found, for the first time, that phase transitions from the titanate nanostructures to TiO(2) polymorphs take place readily in simple wet-chemical processes at temperatures close to ambient temperature. In acidic aqueous dispersions, the fibers transform to anatase and rutile nanoparticles, respectively, but via different mechanisms. The titanate fibers prepared at lower hydrothermal temperatures transform to TiO(2) polymorphs at correspondingly lower temperatures because they are thinner, possess a larger surface area and more defects, and possess a less rigid crystal structure, resulting in lower stability. The transformations are reversible: in this case, the obtained TiO(2) nanocrystals reacted with concentrate NaOH solution, yielding hollow titanate nanotubes. Consequently, there are reversible transformation pathways for transitions between the titanates and the titanium dioxide polymorphs, via wet-chemical reactions at moderate temperatures. The significance of these findings arises because such transitions can be engineered to produce numerous delicate nanostructures under moderate conditions. To demonstrate the commercial application potential of these processes, we also report titanate and TiO(2) nanostructures synthesized directly from rutile minerals and industrial-grade rutiles by a new scheme of hydrometallurgical reactions.

20.
Phys Rev Lett ; 94(8): 086402, 2005 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-15783911

RESUMEN

We have studied the temperature dependent phonon emission rate P(T) of a strongly interacting (r(s) > or =22) dilute 2D GaAs hole system using a standard carrier heating technique. In the still poorly understood metallic state, we observe that P(T) changes from P(T) approximately T5 to P(T) approximately T7 above 100 mK, indicating a crossover from screened piezoelectric (PZ) coupling to screened deformation potential (DP) coupling for hole-phonon scattering. Quantitative comparison with theory shows that the long range PZ coupling between holes and phonons has the expected magnitude; however, in the metallic state, the short range DP coupling between holes and phonons is almost 20 times stronger than expected from theory. The density dependence of P(T) shows that it is easier to cool low-density 2D holes in GaAs than higher density 2D hole systems.

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