Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Front Plant Sci ; 15: 1386109, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38708391

RESUMEN

Compared to conventional irrigation and fertilization, the Water-fertilizer coupling can significantly enhance the efficiency of water and fertilizer utilization, thereby promoting crop growth and increasing yield. Targeting the challenges of poor crop growth, low yield, and inefficient water and fertilizer utilization in the arid region of northwest China under conventional irrigation and fertilization practices. Therefore, a two-year on-farm experiment in 2022 and 2023 was conducted to study the effects of water-fertilizer coupling regulation on pumpkin growth, yield, water consumption (ET), and water and fertilizer use efficiency. Simultaneously the comprehensive evaluation of multiple objectives was carried out using principal component analysis (PCA) methods, so as to propose an suitable water-fertilizer coupling regulation scheme for the region. The experiment was set up as a two-factor trial using water-fertilizer integration technology under three irrigation volume (W1 = 37.5 mm, W2 = 45.5 mm, W3 = 52.5mm) and three organic fertilizer application amounts (F1 = 3900-300 kg ha-1, F2 = 4800-450 kg·ha-1, F3 = 5700-600 kg·ha-1), with the traditional irrigation and fertilization scheme from local farmers as control treatments (CK). The results indicated that irrigation volume and organic fertilizer application significantly affected pumpkin growth, yield, and water and fertilizer use efficiency (P<0.05). Pumpkin yield increased with increasing irrigation volume. Increasing organic fertilizer levels within a certain range benefited pumpkin plant growth, dry matter accumulation, and yield, however, excessive application beyond a certain level had inhibited effects on those. The increased fertilizer application under the same irrigation volume enhanced the efficiency of water and fertilizer utilization. However excessive irrigation only resulted in inefficient water consumption, reducing the water and fertilizer use efficiency. The Comprehensive evaluation by PCA revealed that the F2W3 treatment outperformed all the others, effectively addressing the triple objectives of increasing production, improving efficiency, and promoting green production. Therefore, F2W3 (Irrigation volume: 52.5 mm; Fertilizer application amounts: 4800-450 kg/ha-1) as a water and fertilizer management scheme for efficient pumpkin production in the arid region of northwest China.

2.
Biol Pharm Bull ; 46(8): 1041-1048, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37532555

RESUMEN

Thyroid cancer (TC) is the most common malignant tumor of endocrine system and head and neck. Ononin is an isoflavone component, which exhibited great antioxidant and anti-inflammatory activities. This study was conducted to explore the functions of ononin in the TC progression. The cell counting kit-8 (CCK8) assay was applied for the cell viability determination. The cell death and apoptosis rate were analyzed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining and flow cytometry. The quantitative real-time PCR (qRT-PCR) and Western blot assays were performed for the relative expressions determination. Lactate dehydrogenase (LDH) release assay was used to assess cytotoxicity. Ononin treatment prominently inhibited the cell viability and induced the cell apoptosis of the TC cells. Besides, caspase 3 (CASP3) was down-regulated and CD274 was up-regulated in TC. Ononin treatment prominently decreased the CD274 levels and increased the CASP3 levels in the TC cells. Additionally, ononin treatment dramatically enhanced the LDH release of the cytotoxicity of T cells. What is more, CASP3 overexpression or CD274 knockdown promoted the role of ononin in TC cells. Ononin treatment induced the cell death of the TC cells through regulating the CASP3 and CD274 expressions.


Asunto(s)
Isoflavonas , Neoplasias de la Tiroides , Humanos , Caspasa 3/metabolismo , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/patología , Apoptosis , Proliferación Celular , Línea Celular Tumoral , Antígeno B7-H1
3.
Ann Vasc Surg ; 87: 529-537, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36064130

RESUMEN

BACKGROUND: Diabetic foot (DF) is a prevalent metabolic infection. DF wounds are the basis for all cases of nontraumatic lower limb amputations in diabetes. DF care approaches include debridement of wound, pressure relief in the wounded area, proper wound, infection, and ischemia management. However, there is a need for research to develop more effective therapeutic approaches. This study investigated the effectivity and safety of autologous platelet-rich gel combined with conventional treatment and traditional Chinese medicine (TCM) in DF ulcer therapy. METHODS: Sixty DF ulcer patients were divided into treatment and control groups of 30 patients each. The treatment group involved a combination of autologous platelet-rich gel, conventional treatment, and TCM. The control group was only treated with a combination of conventional therapy and TCM. Laboratory variables, including platelets, hemoglobin (Hb), albumin, and HbA1c, were analyzed and compared between the treatment and the control groups at baseline and endpoint. Healing area, volume, and rates were compared in both groups. RESULTS: Basic patients' data and the wound conditions had no significant difference between the treatment and the control group. The treatment and control groups cure rates were 93.3% vs. 50%, respectively. The healing rate per 2 weeks was significantly higher in the treatment than in the control group (0.78 ± 0.05 vs. 0.43 ± 0.04). There was no statistically significant difference in the platelets, Hb, albumin, and HbA1c levels in the treatment and control groups. CONCLUSIONS: Autologous platelet-rich gel combined with conventional treatment and TCM is effective and safe for DF ulcer treatment.


Asunto(s)
Diabetes Mellitus , Pie Diabético , Plasma Rico en Plaquetas , Humanos , Pie Diabético/diagnóstico , Pie Diabético/terapia , Medicina Tradicional China , Hemoglobina Glucada , Úlcera , Resultado del Tratamiento , Albúminas
4.
Opt Lett ; 47(6): 1331-1334, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35290306

RESUMEN

A lamellar multilayer grating in a conical diffraction mounting was proposed as a beam splitter for X-ray free-electron lasers. Theoretical calculations demonstrated that the distribution of diffraction efficiency can be adjusted by optimizing the groove depth or d-spacing. A Cr/C multilayer lamellar grating with a line density of approximately 2500 L/mm was fabricated. The performance of the element was measured in the Optics Beamline PM-1 (BESSY-II) at an energy of 1500 eV. A five-order diffraction pattern was recognized, and the diffraction efficiencies of the -/+first-order were approximately 12.6 and 4.4%, respectively. The asymmetric distribution of diffraction efficiency can be caused by the different sidewall angles of the grating groove.

5.
Opt Express ; 26(8): 9972-9983, 2018 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-29715942

RESUMEN

This paper examines the characteristics of magneto-optical images of weld defects under alternating magnetic field excitation. Weld defects such as non-penetration, surface cracks and sub-surface cracks were detected by a magneto-optical imaging method. Magneto-optical imaging nondestructive testing experiments under alternating magnetic field excitation were carried out to detect the weld defects. Image processing methods which include contrast enhancement of original image, fused image, contrast enhancement of fused image were applied to extract the defect information of the magneto-optical images. What's more, the difference among the magneto-optical images of weld defects was obtained by contrast analysis. Experimental results show that non-penetration welding images possess significant differences in brightness and darkness, and this difference in cracks is smaller than non-penetrating ones. Under the same excitation conditions, the leakage flux of welds with non-penetration is stronger than that of weld cracks.

6.
Nanoscale ; 8(39): 17278-17284, 2016 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-27714077

RESUMEN

Recent advances in graphene photonics reveal promising applications in the technologically important terahertz spectrum, where graphene-based active terahertz metamaterial modulators have been experimentally demonstrated. However, the sensitivity of the atomically thin graphene monolayer towards sharp Fano resonant terahertz metasurfaces remains unexplored. Here, we demonstrate thin-film sensing of the graphene monolayer with a high quality factor terahertz Fano resonance in metasurfaces consisting of a two-dimensional array of asymmetric resonators. A drastic change in the transmission amplitude of the Fano resonance was observed due to strong interactions between the monolayer graphene and the tightly confined electric fields in the capacitive gaps of the Fano resonator. The deep-subwavelength sensing of the atomically thin monolayer graphene further highlights the extreme sensitivity of the resonant electric field excited at the dark Fano resonance, allowing the detection of an analyte that is λ/1 000 000 thinner than the free space wavelength.

7.
J Synchrotron Radiat ; 23(Pt 4): 1035-45, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27359154

RESUMEN

An undulator-based vacuum ultraviolet (VUV) beamline (BL03U), intended for combustion chemistry studies, has been constructed at the National Synchrotron Radiation Laboratory (NSRL) in Hefei, China. The beamline is connected to the newly upgraded Hefei Light Source (HLS II), and could deliver photons in the 5-21 eV range, with a photon flux of 10(13) photons s(-1) at 10 eV when the beam current is 300 mA. The monochromator of the beamline is equipped with two gratings (200 lines mm(-1) and 400 lines mm(-1)) and its resolving power is 3900 at 7.3 eV for the 200 lines mm(-1) grating and 4200 at 14.6 eV for the 400 lines mm(-1) grating. The beamline serves three endstations which are designed for respective studies of premixed flame, fuel pyrolysis in flow reactor, and oxidation in jet-stirred reactor. Each endstation contains a reactor chamber, an ionization chamber where the molecular beam intersects with the VUV light, and a home-made reflectron time-of-flight mass spectrometer. The performance of the beamline and endstations with some preliminary results is presented here. The ability to detect reactive intermediates (e.g. H, O, OH and hydroperoxides) is advantageous in combustion chemistry research.

8.
Light Sci Appl ; 5(5): e16076, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-30167164

RESUMEN

Metamaterials based on effective media can be used to produce a number of unusual physical properties (for example, negative refraction and invisibility cloaking) because they can be tailored with effective medium parameters that do not occur in nature. Recently, the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements '0' and '1,' which possess opposite phase responses. Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves. We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements. By encoding the elements with elaborately designed coding sequences (both 1-bit and 2-bit sequences), the x- and y-polarized waves can be anomalously reflected or independently diffused in three dimensions. The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface, and the results are consistent with the measured results. We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions, thus providing powerful control of differently polarized electromagnetic waves. The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.

9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(6): 1751-5, 2015 Jun.
Artículo en Chino | MEDLINE | ID: mdl-26601403

RESUMEN

As an important optical splitting element, grating is used in many different spectrometers and spectrographs. Spherical varied-line-spacing grating (SVLSG) is easily combined with array detectors to get a wide wavelength range of spectrums in one time, because it can focus the spectrums in approximately a plane. Therefore, it's widely used in many spectral instruments. We usually only know the central groove density of a commercial grating and its mounting parameters, while its line spacing parameters are unknown. Moreover, the mounting parameters are optimized within the whole using wavelength range of the grating. However, in most circumstances only part of the wavelength range is used. Therefore, the mounting parameters are not optimized for the needed wavelength range. Under this condition, in this article we developed a method based on the focusing theory of the flat-field grating and the mounting parameters the manufacture provided to deduce the line spacing parameters of the grating. With these parameters, we can optimize the detector position according to the wavelength range we need and ray tracing can be done to test the optical system. In this article we developed a high spectral resolution ultraviolet spectrograph, covering a wavelength range of 230-280 nm. The grating used in this spectrograph has a central groove density of 1 200 lines x mm(-1) and a designed wavelength range of 170-500 nm. We deduced the line spacing parameters of the grating and optimized the detector mounting parameters. Hollow cathode lamps of different elements were used to calibrate the spectrograph and test the spectral resolution of it. Wavelength calibration of the spectrograph has been done with the parameter fitting method, and the calibration accuracy is better than 0.01 nm. Results show the spectral resolution of the spectral graph is about 0.08 nm at 280.20 nm.

10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(2): 304-8, 2015 Feb.
Artículo en Chino | MEDLINE | ID: mdl-25970882

RESUMEN

The present paper presents an auto-focus laser-induced breakdown spectroscopy (LIBS) remote measuring system. This system contains a Schwarzschild telescope, which consists of a convex mirror and a concave mirror. The two spherical mirrors are coaxially placed. The convex mirror is mounted on a motorized linear translation stage. With this motorized linear translation stage, the convex mirror can move along the optical axis to change the spacing between the convex mirror and the concave mirror. Therefore the focal length can be adjusted to focus the laser on samples at different distances and collect the plasma spectra. The advantages of the telescope system include, firstly, the light path of laser focusing and spectra signal collection is the same, which make it easier for mounting and collimation; secondly, the light path of the telescope uses total reflection type, which is fit for the detection in ultra-violate region; finally, the telescope consists of only two spherical mirrors which are relatively easier to manufacture. Within the translation range of the motorized linear translation stage, the focal length of the telescope in this paper can be adjusted from 1.5 to 3.6 m. The diameter of the focusing spot varies from 0.5 to 1.0 mm. Utilizing this telescope system, LIBS experiments were conducted using copper sample. And the characteristic lines of Cu element (Cu I 223.01 nm, Cu I 224.43 nm) obtained are used for the auto focusing. By investigating the relation of the area of spectral lines covered and the spacing between the mirrors, the optimal laser focusing location was obtained. The LIBS experiment results show that the system functions well, fulfilling the demand of remote ablation of sample and LIBS spectral measuring, and the telescope is able to auto-focus the laser on samples at different position to perform remote LIBS experiment.

11.
Nat Commun ; 6: 7082, 2015 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-25959596

RESUMEN

Controlling the propagation properties of the terahertz waves in graphene holds great promise in enabling novel technologies for the convergence of electronics and photonics. A diode is a fundamental electronic device that allows the passage of current in just one direction based on the polarity of the applied voltage. With simultaneous optical and electrical excitations, we experimentally demonstrate an active diode for the terahertz waves consisting of a graphene-silicon hybrid film. The diode transmits terahertz waves when biased with a positive voltage while attenuates the wave under a low negative voltage, which can be seen as an analogue of an electronic semiconductor diode. Here, we obtain a large transmission modulation of 83% in the graphene-silicon hybrid film, which exhibits tremendous potential for applications in designing broadband terahertz modulators and switchable terahertz plasmonic and metamaterial devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...