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1.
Nano Lett ; 24(38): 11847-11852, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39264273

RESUMO

The pseudomagnetic field effect may offer unique opportunities for the emergence of intriguing phenomena. To date, investigations into pseudomagnetic field effects on phonons have been limited to sound waves in metamaterials. The revelation of this exotic effect on the atomic vibration of natural materials remains elusive. Our simulations of twisted graphene nanoribbons reveal well-defined Landau spectra and sublattice polarization of phonon states, mimicking the behavior of Dirac Fermions in magnetic fields. Both valley-specified helical edge currents and snake orbits are obtained. Analysis of dynamics indicates that phonon Landau states have extended lifetimes, which are crucial for the realization of Landau-level lasing. Our findings demonstrate the occurrence of the phonon pseudomagnetic field effect in natural materials, which has important implications for the mechanical tuning of phonon quantum states at the atomic scale.

2.
Nano Lett ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38607185

RESUMO

The enhanced Coulomb interaction in two-dimensional semiconductors leads to tightly bound electron-hole pairs known as excitons. The large binding energy of excitons enables the formation of Rydberg excitons with high principal quantum numbers (n), analogous to Rydberg atoms. Rydberg excitons possess strong interactions among themselves as well as sensitive responses to external stimuli. Here, we probe Rydberg exciton resonances through photocurrent spectroscopy in a monolayer WSe2 p-n junction formed by a split-gate geometry. We show that an external in-plane electric field not only induces a large Stark shift of Rydberg excitons up to quantum principal number 3 but also mixes different orbitals and brightens otherwise dark states such as 3p and 3d. Our study provides an exciting platform for engineering Rydberg excitons for new quantum states and quantum sensing.

3.
Opt Express ; 32(6): 9343-9361, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571171

RESUMO

Many chlorophyll-a (Chl-a) remote sensing estimation algorithms have been developed for inland water, and they are proposed always based on some ideal assumptions, which are difficult to meet in complex inland waters. Based on MIE scattering theory, this study calculated the optical properties of mineral particles under different size distribution and refractive index conditions, and the Hydrolight software was employed to simulate remote sensing reflectance in the presence of different mineral particles. The findings indicated that the reflectance is significantly influenced by the slope (j) of particle size distribution function and the imaginary part (n') of the refractive index, with the real part (n) having a comparatively minor impact. Through both a simulated dataset containing 18,000 entries and an in situ measured dataset encompassing 2183 data from hundreds of lakes worldwide, the sensitivities of band ratio (BR), fluorescence baseline height (FLH), and three-band algorithms (TBA) to mineral particles were explored. It can be found that BR showed the best tolerance to mineral particles, followed by TBA. However, when the ISM concentration is less than 30 g m-3, the influence of CDOM cannot be ignored. Additionally, a dataset of over 400 entries is necessary for developing the BR algorithm to mitigate the incidental errors arising from differences in data magnitude. And if the amount of developing datasets is less than 400 but greater than 200, the TBA algorithm is more likely to obtain more stable accuracy.

4.
Mol Pharm ; 21(9): 4476-4489, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39106303

RESUMO

In this study, we prepared bionic selenium-baicalein nanoparticles (ACM-SSe-BE) for the targeted treatment of nonsmall cell lung cancer. Due to the coating of the A549 membrane, the system has homologous targeting capabilities, allowing for the preparation of target tumor cells. The borate ester bond between selenium nanoparticles (SSe) and baicalein (BE) is pH-sensitive and can break under acidic conditions in the tumor microenvironment to achieve the targeted release of BE at the tumor site. Moreover, SSe further enhances the antitumor effect of BE by increasing the production of ROS in tumor cells. Transmission electron microscopy (TEM) images and dynamic light scattering (DLS) showed that the ACM-SSe-BE had a particle size of approximately 155 ± 2 nm. FTIR verified the successful coupling of SSe and BE. In vitro release experiments indicated that the cumulative release of ACM-SSe-BE at pH 5.5 after 24 h was 69.39 ± 1.07%, which was less than the 20% release at pH 7.4, confirming the pH-sensitive release of BE in ACM-SSe-BE. Cell uptake experiments and in vivo imaging showed that ACM-SSe-BE had good targeting ability. The results of MTT, flow cytometry, Western blot, and cell immunofluorescence staining demonstrated that ACM-SSe-BE promoted A549 cell apoptosis and inhibited cell proliferation. The in vivo antitumor results were consistent with those of the cell experiments. These results clearly suggested that ACM-SSe-BE will be a promising bionic nanosystem for the treatment of nonsmall cell lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Flavanonas , Neoplasias Pulmonares , Nanopartículas , Selênio , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Nanopartículas/química , Selênio/química , Flavanonas/química , Flavanonas/farmacologia , Flavanonas/administração & dosagem , Flavanonas/uso terapêutico , Animais , Células A549 , Camundongos , Apoptose/efeitos dos fármacos , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Camundongos Nus , Concentração de Íons de Hidrogênio , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular Tumoral , Camundongos Endogâmicos BALB C , Liberação Controlada de Fármacos
5.
Environ Res ; 237(Pt 1): 116898, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37591322

RESUMO

Water clarity is a critical parameter of water, it is typically measured using the setter disc depth (SDD). The accurate estimation of SDD for optically varying waters using remote sensing remains challenging. In this study, a water classification algorithm based on the Landsat 5 TM/Landsat 8 OLI satellite was used to distinguish different water types, in which the waters were divided into two types by using the ad(443)/ap(443) ratio. Water type 1 refers to waters dominated by phytoplankton, while water type 2 refers to waters dominated by non-algal particles. For the different water types, a specific algorithm was developed based on 994 in situ water samples collected from Chinese inland lakes during 42 cruises. First, the Rrs(443)/Rrs(655) ratio was used for water type 1 SDD estimation, and the band combination of (Rrs(443)/Rrs(655) - Rrs(443)/Rrs(560)) was proposed for water type 2. The accuracy assessment based on an independent validation dataset proved that the proposed algorithm performed well, with an R2 of 0.85, mean absolute percentage error (MAPE) of 25.98%, and root mean square error (RMSE) of 0.23 m. To demonstrate the applicability of the algorithm, it was extensively evaluated using data collected from Lake Erie and Lake Huron, and the estimation accuracy remained satisfactory (R2 = 0.87, MAPE = 28.04%, RMSE = 0.76 m). Furthermore, compared with existing empirical and semi-analytical SDD estimation algorithms, the algorithm proposed in this paper showed the best performance, and could be applied to other satellite sensors with similar band settings. Finally, this algorithm was successfully applied to map SDD levels of 107 lakes and reservoirs located in the Middle-Lower Yangtze Plain (MLYP) from 1984 to 2020 at a 30 m spatial resolution, and it was found that 53.27% of the lakes and reservoirs in the MLYP generally show an upward trend in SDD. This research provides a new technological approach for water environment monitoring in regional and even global lakes, and offers a scientific reference for water environment management of lakes in the MLYP.

6.
J Neurophysiol ; 127(2): 397-404, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34986062

RESUMO

Whether pinocembrin (PCN) could be used to alleviate hip fracture-induced pain is investigated in this research. Aged rats with hip fractures were treated with vehicle or 80 mg/kg/day PCN from week 3 to week 4. Then, hind paw mechanical allodynia, unweighting, warmth, and thickness were measured. The microglia and astrocytes activation and proliferation markers in the spinal dorsal horn were detected with real-time PCR and immunofluorescence staining. The relative expression of substance P and its receptor, tachykinin receptor 1 (Tacr1), was detected with enzyme-linked immunosorbent assay (ELISA) and Western blots. The antinociceptive effect of Tacr1 inhibitor LY303870 was also testified. PCN alleviated hip fracture-induced hind paw nociceptive (allodynia and unweighting) and vascular changes (warmth and thickness) in aged rats with diminished microglia and astrocytes activation and proliferation in the spinal dorsal horn. Upregulated substance P and Tacr1 were induced after hip fracture, which could be reversed by PCN treatment. Furthermore, LY303870 treatment partially reversed both spinal nociceptive sensitization and vascular changes after hip fracture. Substance P signaling contributes to the nociceptive and vascular changes observed in the hip fracture, which could be alleviated by PCN.NEW & NOTEWORTHY Substance P signaling contributes to the nociceptive and vascular changes observed in hip fracture, which could be alleviated by PCN.


Assuntos
Envelhecimento , Flavanonas/farmacologia , Fraturas do Quadril/tratamento farmacológico , Antagonistas dos Receptores de Neurocinina-1/farmacologia , Dor/tratamento farmacológico , Substância P/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Flavanonas/administração & dosagem , Fraturas do Quadril/complicações , Fraturas do Quadril/metabolismo , Indóis/farmacologia , Masculino , Antagonistas dos Receptores de Neurocinina-1/administração & dosagem , Dor Nociceptiva/tratamento farmacológico , Dor Nociceptiva/etiologia , Dor Nociceptiva/metabolismo , Dor/etiologia , Dor/metabolismo , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
7.
Cancer Control ; 29: 10732748221099227, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35499497

RESUMO

BACKGROUND: The overall incidence and mortality of gastric cancer have steadily declined in the United States over the past few decades, but it is still a serious disease burden for patients. Therefore, it is of great significance to evaluate the latest survival rate of gastric cancer. METHODS: Based on the Surveillance, Epidemiology, and End Results database, this study analyzed the age-standardized relative survival rates and survival trends of gastric cancer cases in 2007-2011 and 2012-2016 using period analysis, and the survival rate 2017-2021 was predicted using a generalized linear model based on the period analysis. RESULTS: During 2007-2016, the 5-year relative survival rate of patients with gastric cancer continued to rise, and the same trend was observed in 2017-2021. The 5-year overall age-standardized relative survival rates in 2007-2011, 2012-2016, and 2017-2021 were 38.3%, 40.6%, and 42.9%, respectively. However, despite these favorable trends, the overall relative survival of patients with gastric cancer remains at a low level. There were significant differences in the relative survival rates of patients with gastric cancer in terms of age, sex, race, primary site, stage, and socioeconomic status. Notably, the survival rate of patients with distant-stage gastric cancer remains very low (10%). CONCLUSION: We found that the survival rate of patients with gastric cancer showed different degrees of improvement in each subgroup. However, the overall relative survival rate of patients with gastric cancer remains low. Analyzing the changes of patients with gastric cancer in the last 10 years will be helpful in predicting the changing trend of cancer in the future. It also provides a scientific basis for relevant departments to formulate effective tumor prevention and control measures.


Assuntos
Neoplasias Gástricas , Bases de Dados Factuais , Humanos , Incidência , Classe Social , Neoplasias Gástricas/patologia , Taxa de Sobrevida , Estados Unidos/epidemiologia
8.
Cancer Control ; 29: 10732748221135447, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36256588

RESUMO

BACKGROUND: The rapid increase in the detection rate of thyroid cancer over the past few decades has caused some unexpected economic burdens. However, that of papillary thyroid carcinoma (PTC) seems to have had the opposite trend, which is worthy of further comprehensive exploration. METHODS: The Surveillance, Epidemiology, and End Results 18 database was used to identify patients with PTC diagnosed during 2003-2017. The incidence trends were analyzed using joinpoint analysis and an age-period-cohort model. RESULTS: The overall PTC incidence rate increased from 9.9 to 16.1 per 100 000 between 2003 and 2017. The joinpoint analysis indicated that the incidence growth rate began to slow down in 2009 (annual percentage change [APC] = 3.1%, 95% confidence interval [CI] = 1.9%-4.4%). After reaching its peak in 2015, it began to decrease by 2.8% (95% CI = -4.6% to -1.0%) per year. The stratified analysis indicated that the incidence patterns of different sexes, age groups, races, and tumor stages and sizes had similar downward trends, including for the localized (APC = -4.5%, 95% CI = -7% to -1.9%) and distant (APC = -1.3%, 95% CI = -2.7% to -.1%) stages, and larger tumors (APC = -4%, 95% CI = -12% to 4.7%). The age-period-cohort model indicated a significant period effect on PTC, which gradually weakened after 2008-2012. The cohort effect indicates that the risk of late birth cohorts is gradually stabilizing and lower than that of early birth cohorts. CONCLUSION: The analysis results of the recent downward trend and period effect for the incidence of each subgroup further support the important role of correcting overdiagnosis in reducing the prevalence of PTC. Future research needs to analyze more-recent data to verify these downward trends.


Assuntos
Neoplasias da Glândula Tireoide , Humanos , Estados Unidos/epidemiologia , Câncer Papilífero da Tireoide/epidemiologia , Incidência , Programa de SEER , Neoplasias da Glândula Tireoide/patologia , Grupos Raciais
9.
BMC Surg ; 22(1): 250, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768816

RESUMO

PURPOSE: The aim of this study was to explore the efficacy of sternoclavicular hook plate for treatment of proximal clavicle fracture with dislocation of sternoclavicular joint. METHODS: Between October 2016 and December 2020, 16 cases (9 male and 7 female patient, with a mean age of (42 ± 10) years) of proximal clavicle fracture with dislocation of sternoclavicular joint were included in the study. Injured side, injury mechanism, time to surgery, Complications and duration of follow-up were recorded. The outcomes were evaluated with radiographic assessment, American Shoulder and Elbow Surgeons' Form (ASES). All the patients were evaluated on postoperative 3rd, 6th, and 12th months. RESULTS: According to the ASES scoring system, the average score was 49 ± 4 (preoperative score), 87 ± 5 (3 months follow-up), 88 ± 3 (6 months follow-up) and 91 ± 3 (12 months follow-up). Statistics differences was showed between preoperative and 3,6,12 months follow-up score of ASES score (p < 0.001). The postoperative physical function was better than the preoperative function. Internal fixation failure and fracture non-union complications in two patients. CONCLUSION: Our study indicates that open reduction and sternoclavicular hook plate fixation for the treatment of traumatic sternoclavicular fracture is a safe, relatively straightforward surgical procedure that can lead to satisfactory outcomes.


Assuntos
Fraturas Ósseas , Luxações Articulares , Articulação Esternoclavicular , Adulto , Placas Ósseas , Clavícula/cirurgia , Feminino , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Pessoa de Meia-Idade , Articulação Esternoclavicular/lesões , Articulação Esternoclavicular/cirurgia , Resultado do Tratamento
10.
J Environ Manage ; 310: 114734, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35220103

RESUMO

Cyanobacterial blooms are one of the most severe ecological problems affecting lakes. The vertical migration of cyanobacteria in the water column increases the uncertainty in the formation and disappearance of blooms, which may be closely associated with light, temperature, and wind speed. However, it is difficult to quantitatively evaluate the influencing factors of cyanobacteria vertical movement in natural environment compared to the laboratory experimental environment. Besides, both field survey and laboratory experiment method have the difficulties in determining the diurnal vertical migration of cyanobacteria at the synoptic lake scale. In this study, based on the diurnal dynamics of cyanobacterial bloom intensity (CBI) observed by the Geostationary Ocean Color Imager (GOCI) from 2011 to 2019, the daily variations, floating rate, and sinking rate of Microcystis aeruginosa were calculated in the natural environment. Then, the effects of light, temperature, and wind speed on the vertical migration of M. aeruginosa were analysed from the perspectives of day, night, and season. The results are as follows: the records of three typical patterns of diurnal CBI exhibited strong seasonal variability from the 9-year statistics; at night, the buoyancy recovery rate of cyanobacterial colonies increased with temperature, so that at temperature >15 °C and wind speed <3 m s-1, CBI reached the maximum of the whole day at 08:16; the sinking rate of M. aeruginosa was positively correlated with the cumulated light energy at both synoptic and pixel scale; the upward migration speed of M. aeruginosa was positively correlated with the maximum wind speed of the day before cyanobacterial bloom. Therefore, the severer cyanobacterial blooms were often observed by satellite images after strong winds. The analysis of diurnal variation, floating rate, and sinking rate of M. aeruginosa will expand our knowledge for further understanding the formation mechanism of cyanobacterial blooms and for improving the accuracy of model simulation to predict the hourly changes in cyanobacterial blooms in Lake Taihu.


Assuntos
Cianobactérias , Microcystis , China , Monitoramento Ambiental/métodos , Eutrofização , Lagos
11.
BMC Musculoskelet Disord ; 22(1): 991, 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34836534

RESUMO

INTRODUCTION: The purpose is based on anatomical basis, combined with three-dimensional measurement, to guide the clinical repositioning of proximal humeral fractures, select the appropriate pin entry point and angle, and simulate surgery. METHODS: 11 fresh cadaveric specimens were collected, the distance of the marked points around the shoulder joint was measured anatomically, and the vertical distance between the inferior border of the acromion and the superior border of the axillary nerve, the vertical distance between the apex of the humeral head and the superior border of the axillary nerve, the vertical distance between the inferior border of the acromion and the superior border of the anterior rotator humeral artery, and the vertical distance between the apex of the humeral head and the superior border of the anterior rotator humeral artery were marked on the 3D model based on the anatomical data to find the relative safety zone for pin placement. RESULTS: Contralateral data can be used to guide the repositioning and fixation of that side of the proximal humerus fracture, and uniform data cannot be used between male and female patients. For lateral pining, the distance of the inferior border of the acromion from the axillary nerve (5.90 ± 0.43) cm, range (5.3-6.9) cm, was selected for pining along the medial axis of the humeral head, close to the medial cervical cortex, and the pining angle was measured in the coronal plane (42.84 ± 2.45)°, range (37.02° ~ 46.31°), and in the sagittal plane (28.24 ± 2.25)°, range (19.22° ~ 28.51°). The pin was advanced laterally in front of the same level of the lateral approach point to form a cross-fixed support with the lateral pin, and the pin angle was measured in the coronal plane (36.14 ± 1.75)°, range (30.32° ~ 39.61°), and in the sagittal plane (28.64 ± 1.37)°, range (22.82° ~ 32.11°). Two pins were taken at the greater humeral tuberosity for fixation, with the proximal pin at an angle (159.26 ± 1.98) to the coronal surface of the humeral stem, range (155.79° ~ 165.08°), and the sagittal angle (161.76 ± 2.15)°, with the pin end between the superior surface of the humeral talus and the inferior surface of the humeral talus. The distal needle of the greater humeral tuberosity was parallel to the proximal approach trajectory, and the needle end was on the inferior surface of the humeral talus. CONCLUSION: Based on the anatomical data, we can accurately identify the corresponding bony structures of the proximal humerus and mark the location of the pin on the 3D model for pin placement, which is simple and practical to meet the relevant individual parameters.


Assuntos
Fraturas do Úmero , Fraturas do Ombro , Idoso , Fixadores Externos , Feminino , Fixação de Fratura , Humanos , Cabeça do Úmero , Úmero/diagnóstico por imagem , Úmero/cirurgia , Masculino , Ombro , Fraturas do Ombro/diagnóstico por imagem , Fraturas do Ombro/cirurgia
12.
Nano Lett ; 20(10): 7635-7641, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32902286

RESUMO

A strong Coulomb interaction could lead to a strongly bound exciton with high-order excited states, similar to the Rydberg atom. The interaction of giant Rydberg excitons can be engineered for a correlated ordered exciton array with a Rydberg blockade, which is promising for realizing quantum simulation. Monolayer transition metal dichalcogenides, with their greatly enhanced Coulomb interaction, are an ideal platform to host the Rydberg excitons in two dimensions. Here, we employ helicity-resolved magneto-photocurrent spectroscopy to identify Rydberg exciton states up to 11s in monolayer WSe2. Notably, the radius of the Rydberg exciton at 11s can be as large as 214 nm, orders of magnitude larger than the 1s exciton. The giant valley-polarized Rydberg exciton not only provides an exciting platform to study the strong exciton-exciton interaction and nonlinear exciton response but also allows the investigation of the different interplay between the Coulomb interaction and Landau quantization, tunable from a low- to high-magnetic-field limit.

13.
Bull Environ Contam Toxicol ; 106(4): 608-613, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33491127

RESUMO

Based on a typical residential area, this paper studies the characteristics of pollutant concentration changes in two rainfall runoffs and the first flush effect of rainfall. In rainfall runoff, the concentrations of seven pollutants (CODMn, TN, DTN, NH3-N, TP, DTP, and PO43-) increased during the initial rainfall period and decreased in the later period. Rainfall causes the erosion of pollutants on the underlying surface so that water pollution begins when rainfall runoff occurs, and the pollution level drops over time. The seven pollutants all experience this first flush effect, of which, rainfall has the strongest scouring effect on NH3-N produced by domestic sewage. The significant excess of pollutants in rainfall runoff should be considered by management departments. In addition, the existence of the first flush effect makes it possible in theory to partially intercept rainfall runoff to control water pollution, thereby reducing the cost of pollution control.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , China , Cidades , Monitoramento Ambiental , Chuva , Movimentos da Água , Poluentes Químicos da Água/análise
14.
Phys Rev Lett ; 124(22): 227001, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32567912

RESUMO

Second-order topological superconductors host Majorana corner and hinge modes in contrast to conventional edge and surface modes in two and three dimensions. However, the realization of such second-order corner modes usually demands unconventional superconducting pairing or complicated junctions or layered structures. Here we show that Majorana corner modes could be realized using a 2D quantum spin Hall insulator in proximity contact with an s-wave superconductor and subject to an in-plane Zeeman field. Beyond a critical value, the in-plane Zeeman field induces opposite effective Dirac masses between adjacent boundaries, leading to one Majorana mode at each corner. A similar paradigm also applies to 3D topological insulators with the emergence of Majorana hinge states. Avoiding complex superconductor pairing and material structure, our scheme provides an experimentally realistic platform for implementing Majorana corner and hinge states.

15.
J Environ Manage ; 262: 110321, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250804

RESUMO

Globally, some vegetation has grown significantly over the past decades, but the climate benefits remain unclear, especially in the temperate regions. Understanding the biophysical effects and identifying the potential of vegetation will help to mitigate climate change. Here, we propose a vegetation-adjusted temperature index to understand how terrestrial vegetation growth in China affects the air temperature for 2001-2013, based on satellite-derived normalized difference vegetation index, near-surface air temperature (Ta) and the land surface temperature. Grassland growth and cropland growth are found to cool the Ta by -0.08 ± 0.32 °C (mean ± one standard deviation) and -0.06 ± 0.28 °C, respectively. Forest growth results in net climate warming by 0.05 ± 0.29 °C. Biophysical effects, elevation and background climate are used to explain the climate impacts of vegetation. Results show that the biophysical effects dominate the climate impact. More specifically, evapotranspiration (ET) controls the daytime climate impact, and at night, an indirect effect of albedo (the release of daytime heat storage) dominates it. Lower precipitation, temperature and elevation reinforce the warming potential. Moreover, the effects of albedo and ET on climate are nonlinear. During the day, although lower albedo absorbs more incoming radiation, it releases more extra heat per unit ET that can compensate for the increased incoming radiation. At night, the warming effect reflects the release of daytime heat storage. Overall, tropical vegetation growth (-0.04 ± 0.10 °C) and warm temperate vegetation growth (-0.08 ± 0.15 °C) achieve the climatic benefits. Overall, the method proposed contributes to quantitatively evaluate the role of afforestation plan on regional climate cooling, and provides some policy/practical implications for future afforestation projects. Future afforestation projects should carefully consider the biophysical process and background climate to mitigate climate change.


Assuntos
Mudança Climática , Florestas , China , Temperatura
16.
Opt Express ; 27(24): 34838-34856, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31878664

RESUMO

Water optical clustering based on water color information is important for many ecological and environmental application studies, both regionally and globally. The fuzzy clustering method avoids the sharp boundaries in type-memberships produced by hard clustering methods, and thus presents its advantages. However, to make good use of the fuzzy clustering methods on water color spectra data sets, the determination of the fuzzifier parameter (m) of FCM (fuzzy c-means) is the key factor. Usually, the m is set to 2 by default. Unfortunately, this method assigned some membership degrees to non-belonging water type, failing to obtain the unitarity of cluster structure in some cases, especially in inland eutrophic water. To overcome this shortcoming, we proposed an improved FCM method (namely FCM-m) for water color spectra classification by optimizing the fuzzifier parameter. We collected an inland data set containing 1280 in situ spectral data and co-measured water quality parameters with a wide range of biogeochemical variability in China. Using FCM-m, seven spectrally distinct water optical clusters on Sentinel-3 OLCI (Ocean and Land Colour Imager) bands were obtained with the optimized fuzzifier (m=1.36), and the well-performed clustering result is assessed by the validated index (Fuzzy Silhouette Index=0.513). Also, the FCM-m-based soft classification framework was successfully applied to the atmospherically corrected OLCI images, which was evaluated by previous case studies. Besides, by testing FCM-m on three coastal and oceanic data sets, we verified that the optimized m should be adjusted based on the data set itself, and in general, the value gradually approaches 1 with the increase of the band number (or dimension). Finally, the effect of the improved method was tested by Chlorophyll-a concentration estimation. The results show that the algorithm------- blending by FCM-m performs better than that by original FCM, which is mainly because the FCM-m reduces the estimation error from non-belonging clusters by a stricter membership value assignation. To sum up, we believe that FCM-m is an adaptive algorithm, whose R codes are available at https://github.com/bishun945, and needs to be tested by more public data sets.

17.
18.
Nano Lett ; 18(5): 3032-3037, 2018 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-29676154

RESUMO

Manipulation of magnons opens an attractive direction in the future energy-efficient information processing devices. Such quasi-particles can transfer and process information free from the troublesome Ohmic loss in conventional electronic devices. Here, we propose to realize topologically protected magnon modes using the interface between the patterned ferrimagnetic insulator thin films of different configurations without the Dzyaloshinskii-Moriya interaction. The interface thus behaves like a perfect waveguide to conduct the magnon modes lying in the band gap. These modes are immune to backscattering even in sharply bent tracks, robust against the disorders, and maintain a high degree of coherence during propagation. We design a magnonic Mach-Zehnder interferometer, which realizes a continuous change of magnon signal with varying external magnetic field or driving frequency. Our results pave a new way for realizing topologically protected magnon waveguide and finally achieving a scalable low-dissipation spintronic devices and even the magnonic integrated circuit.

19.
Nanotechnology ; 29(21): 215202, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29517491

RESUMO

Tunable transport properties and Fano resonances are predicted in a circular bilayer phosphorene nanoring. The conductance exhibits Fano resonances with varying incident energy and applied perpendicular magnetic field. These Fano resonance peaks can be accurately fitted with the well known Fano curves. When a magnetic field is applied to the nanoring, the conductance oscillates periodically with magnetic field which is reminiscent of the Aharonov-Bohm effect. Fano resonances are tightly related to the discrete states in the central nanoring, some of which are tunable by the magnetic field.

20.
BMC Cardiovasc Disord ; 18(1): 95, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769019

RESUMO

BACKGROUND: Hong Kong (HK) and Guangzhou (GZ) are cities in China with different healthcare systems. This study aimed to compare 30-day and 6-month mortality and characteristics of patients with suspected cardiac chest pain admitted to two emergency departments (ED) in HK and GZ. METHODS: A prospective observational study enrolled patients with suspected cardiac chest pain presenting to EDs in the Prince of Wales Hospital (PWH), HK and the Second Affiliated Hospital of Guangzhou Medical University (AHGZMU),GZ. The primary outcome was 30-day and 6-month mortality. RESULTS: In total, 996 patients were recruited, 407 cases from GZ and 589 cases from HK.The 30-day and 6-month mortality of chest patients were 3.7% and 4.7% in GZand 0.3% and 1.9% in HK, respectively. Serum creatinine level (Cr) was an independent factor for 30-day mortality whilst Cr and systolic blood pressure (SBP) were independent factors for 6-month mortality. In Cox regression analysis, unadjusted and adjusted hazard ratios for 30-day and 6-month mortality in GZ were significantly increased. CONCLUSION: The 30-day and 6-month mortality of patients with suspected cardiac chest pain in Guangzhou were higher than in Hong Kong due to due to different baseline clinical characteristics of patients and different distributions of diagnoses, which were associated with different healthcare systems. Serum creatinine and SBP were independent factors for 30-day and 6-month mortality.


Assuntos
Angina Pectoris/diagnóstico , Angina Pectoris/mortalidade , Serviço Hospitalar de Cardiologia , Serviço Hospitalar de Emergência , Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde , Idoso , Idoso de 80 Anos ou mais , Angina Pectoris/sangue , Angina Pectoris/fisiopatologia , Biomarcadores/sangue , Pressão Sanguínea , Comorbidade , Creatinina/sangue , Feminino , Frequência Cardíaca , Hong Kong/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo
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