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1.
Int J Mol Sci ; 22(3)2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33503808

RESUMEN

Neutrophils produce hypochlorous acid (HOCl) as well as other reactive oxygen species as part of a natural innate immune response in the human body; however, excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. Comparison of the in vitro anti-hypochlorite activities of a novel betalain-rich red beetroot (Beta vulgaris L.) extract with its pure betalainic pigments revealed that the extract had the highest anti-hypochlorite activity, far exceeding the activity of all of the betalainic derivatives and selected reference antioxidants. This suggests that it may be an important food-based candidate for management of inflammatory conditions induced by excessive HOCl production. Among all pigments studied, betanidin exhibited the highest activity across the pH range.


Asunto(s)
Beta vulgaris/química , Betacianinas/química , Betalaínas/química , Colorantes/química , Ácido Hipocloroso/química , Pigmentos Biológicos/química , Extractos Vegetales/química , Cromatografía Liquida , Humanos , Estructura Molecular , Oxidación-Reducción , Hipoclorito de Sodio/química , Espectrometría de Masa por Ionización de Electrospray , Análisis Espectral , Espectrometría de Masas en Tándem
2.
J BUON ; 23(4): 958-964, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30358199

RESUMEN

PURPOSE: This study aimed to investigate the outcomes of hepatocellular carcinoma (HCC) patients after curative microwave ablation (MWA) with and without diabetes mellitus (DM). METHODS: A total of 308 patients with HCC were retrospectively studied from 2005 to 2012 over an 8-year period. They were all successfully treated by MWA. Progression-free survival (PFS) and overall survival (OS) were analyzed according to the status of DM. The presence of other comorbidities and tumor status were studied using multivariate analysis. RESULTS: Significant differences were observed both for 1-, 3-, 5- year's PFS rates (DM: 63.8, 23.0 and 15.8 vs non-DM: 72.7, 43.6 and 30.8%; p=0.013) and OS rates (DM: 87.3, 75.1 and 49.5% vs non-DM: 97.9, 82.9 and 70.5%; p=0.045) between patients with and without DM. Cox multivariate analysis identified the following factors significantly associated with PFS: (hazard ration (HR): 1.191, 95% CI: 1.051-1,349, p=0.006), AFP (HR:1.000, 95% CI: 1.000-1.000, p=0.022), alcohol abuse (>100g/d vs ≤100g/d, HR:1.579, 95% CI:1.128- 2.212, p=0.008), mean fasting plasma glucose level after initial therapy for HCC(>7.0 / ≤7.0, HR:2.728, 95%CI:1.414- 5.265, p=0.003); and the followings associated with OS:Child-Pugh classification A against B, C (risk 1.692, 95%CI 1.065-2.689, P=0.026), tumor diameter (risk 1.251. 95% CI 1.021-1.534, P=0.031), and AFP (risk 1.000. 95% CI 1.000- 1.000, P=0.000). CONCLUSION: DM may affect the HCC progression and overall survival in patients undergoing curative MWA. A good control of the glucose levels after ablation may be important for improving the prognosis of HCC.


Asunto(s)
Técnicas de Ablación/métodos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/cirugía , Diabetes Mellitus/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/cirugía , Microondas/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Diabetes Mellitus/patología , Femenino , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Pronóstico , Estudios Retrospectivos , Resultado del Tratamiento
3.
Opt Lett ; 42(2): 358-361, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-28081112

RESUMEN

It is found that the optimum annealing temperature is about 1000°C for the infrared emission of defect states at room temperature on black silicon (BS) prepared by using a nanosecond-pulsed laser. In addition, it is observed that the suitable annealing time is 6∼8 min at 1000°C for the emission on the BS. The crystallizing proceeding in annealing on the BS can be used to explain the above annealing effect. It is interesting that the emission band becomes intensive and broader on the BS prepared in oxygen atmosphere than that prepared in vacuum in the analysis of photoluminescence spectra, where the electronic states localized at the defects from D1 to D4 doped with oxygen play an important role in the emission with the broader band which are obviously enhanced in the room temperature.

4.
Int J Hyperthermia ; 30(5): 306-11, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25144820

RESUMEN

PURPOSE: This study was designed to describe the technical essentials of microwave ablation (MWA) for tumours adjacent to the liver marginal angle (LMA) and to determine the feasibility, safety and efficacy of this approach. MATERIALS AND METHODS: A total of 22 patients with primary or metastatic liver tumours adjacent to the LMA were enrolled. There were 19 small tumours (≤3 cm) and three larger tumours (>3 cm) with maximum diameters ranging from 0.7-2.7 cm (mean 1.7 ± 0.6 cm) and 4.7-6.6 cm (mean 5.4 ± 1.0 cm), respectively. For small tumours the entire acute angle was segmentally blocked utilising MWA. For larger tumours, the feeding arteries were initially blocked with ethanol before conformal ablation. Artificial ascites, real-time monitoring, small ethanol doses, colour Doppler flow imaging or contrast enhanced ultrasound guidance was used as an additional technique to assist with ablation. Contrast imaging was performed to evaluate the ablative efficacy. Treatment responses, local tumour progression (LTP) and complications were recorded. RESULTS: All patients achieved a complete response. LTP was identified in two cases (9.1%) during the 4.5 month median follow-up period (range 2-29 months). A total of five additional sessions were performed, and secondary effectiveness was achieved in patients with LTP. No major complications were observed. CONCLUSIONS: Percutaneous MWA is a new promising technique for tumours adjacent to the LMA, especially in cases with small tumours. Technical improvements to this procedure are expected to improve the results for large tumours abutting the LMA.


Asunto(s)
Técnicas de Ablación/métodos , Carcinoma Hepatocelular/cirugía , Neoplasias Hepáticas/cirugía , Microondas/uso terapéutico , Adulto , Anciano , Líquido Ascítico , Carcinoma Hepatocelular/diagnóstico por imagen , Femenino , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Ultrasonografía
5.
Int J Gen Med ; 17: 1493-1498, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38655006

RESUMEN

Objective: To investigate the risk factors for the development of portal hypertension in patients with decompensated cirrhosis and analyze their prognosis. Methods: Patients with decompensated cirrhosis who were admitted to our hospital and Qu fu People's Hospital from June 2022 to June 2023 were included in this study. Among them, there were 45 male and 15 female patients, with a median age of 56 (range: 35-77) years. A comparative analysis was performed between Group A (hepatic venous pressure gradient, HVPG <16 mmHg) and Group B (HVPG ≥16 mmHg) patients, along with various clinical outcomes. Multivariate analysis was conducted to explore the risk factors influencing the occurrence of portal hypertension and adverse prognosis in patients with cirrhosis. Results: In Group A patients with portal hypertension, we observed lower levels of aspartate aminotransferase, laminin, serum hyaluronic acid, type III procollagen N-terminal peptide, total bile acids, and cholylglycine acid compared to Group B. On the other hand, levels of alanine aminotransferase, white blood cells, and serum albumin were higher in Group A than in Group B. These differences between the groups were statistically significant (P < 0.05). Multivariate analysis of the aforementioned risk factors indicated that low white blood cell count, high cholylglycine acid levels, and high serum hyaluronic acid levels were identified as independent risk factors for the occurrence of difficult-to-control complications in decompensated portal hypertension among patients with liver cirrhosis (P < 0.05). Conclusion: Liver cirrhosis patients with portal hypertension and multiple risk factors like low white blood cell count and high liver transaminase levels should be cautious regarding the progression of portal hypertension when combined with splenomegaly, liver fibrosis, and bile stasis, as it often indicates a poor prognosis.

6.
Analyst ; 138(11): 3264-70, 2013 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-23612188

RESUMEN

In this study, a boron-dipyrromethene (BODIPY)-based fluorescent chemosensor CBS was developed for metal ion sensing. It was found that CBS containing an NSe2 moiety exhibited high selectivity for Cu(2+) detection while CBS in the presence of Cu(2+) displayed significant fluorescence enhancement. However, the metal ions Ag(+), Ca(2+), Co(2+), Cr(3+), Fe(2+), Fe(3+), Hg(2+), K(+), Mg(2+), Mn(2+), Ni(2+), Pb(2+), and Zn(2+) produced only minor changes in the fluorescence values of the system. The binding constant (Ka) of Cu(2+) binding to CBS was found to be 7.28 × 10(3) M(-1). The binding ratio of CBS-Cu(2+) complexes was determined from the Job plot to be 1 : 1. The maximum fluorescence enhancement caused by Cu(2+) binding to CBS was observed over the pH range 5.0-9.0. Additionally, the methyl thiazolyl tetrazolium (MTT) assay demonstrated the CBS to have low cytotoxicity. Confocal fluorescence microscopy imaging using RAW264.7 cells showed that CBS could be used as an effective fluorescent probe for detecting Cu(2+) in living cells.


Asunto(s)
Quelantes/química , Técnicas de Química Analítica/instrumentación , Cobre/análisis , Imagen Molecular/métodos , Compuestos de Organoselenio/química , Animales , Compuestos de Boro/química , Línea Celular , Supervivencia Celular , Color , Cobre/química , Ratones , Modelos Moleculares , Conformación Molecular , Espectrometría de Fluorescencia
7.
J Fluoresc ; 23(6): 1139-45, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23821065

RESUMEN

A new pyrene-based chemosensor (1) exhibits excellent selectivity for Fe(3+) ions over a wide range of tested metal ions Ag(+), Ca(2+), Cd(2+), Co(2+), Cu(2+), Fe(2+), Hg(2+), K(+), Mg(2+), Mn(2+), Ni(2+), Pb(2+), and Zn(2+). The binding of Fe(3+) to chemosensor 1 produces an emission band at 507 nm due to the formation of a Py-Py* excimer that is induced by Fe(3+)-binding. The binding ratio of 1-Fe(3+) was determined to be 1:1 from a Job plot. The association constant of 1-Fe(3+) complexes was found to be 1.27 × 10(4) M(-1) from a Benesi-Hildebrand plot. In addition, fluorescence microscopy experiments show that 1 can be used as a fluorescent probe for detecting Fe(3+) in living cells.


Asunto(s)
Compuestos Férricos/análisis , Colorantes Fluorescentes/química , Pirenos/química , Colorantes Fluorescentes/síntesis química , Células HeLa , Humanos , Iones/análisis , Estructura Molecular , Pirenos/síntesis química , Teoría Cuántica , Espectrometría de Fluorescencia/instrumentación , Células Tumorales Cultivadas
8.
J Fluoresc ; 22(1): 253-9, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21870075

RESUMEN

A new pyrene derivative (chemosensor 1) containing a picolinohydrazide moiety exhibits high selectivity for Cu(2+) ion detection in mixed aqueous media (CH(3)OH:H(2)O = 7:3). Significant fluorescence enhancement was observed with chemosensor 1 in the presence of Cu(2+). However, the metal ions Ag(+), Ca(2+), Cd(2+), Co(2+), Cu(2+), Fe(2+), Fe(3+), Hg(2+), K(+), Mg(2+), Mn(2+), Ni(2+), Pb(2+), and Zn(2+) produced only minor changes in fluorescence for the system. The apparent association constant (K(a)) of Cu(2+) binding in chemosensor 1 was found to be 2.75*10(3) M(-1). The maximum fluorescence enhancement caused by Cu(2+) binding in chemosensor 1 was observed over the pH range 5-8. Moreover, by means of fluorescence microscopy experiments, it is demonstrated that 1 can be used as a fluorescent probe for detecting Cu(2+) in living cells.


Asunto(s)
Técnicas de Química Analítica/instrumentación , Cobre/análisis , Cobre/química , Colorantes Fluorescentes/química , Imagen Molecular/métodos , Pirenos/química , Supervivencia Celular , Células HeLa , Humanos , Espectrometría de Fluorescencia
9.
Ying Yong Sheng Tai Xue Bao ; 33(6): 1511-1517, 2022 Jun.
Artículo en Zh | MEDLINE | ID: mdl-35729127

RESUMEN

To select the tree species assembly model for improving the productivity in south subtropical plantations, we carried out an experiment following a random block design with eight native tree species across a richness gradient of 1, 2, 4, and 6 species. The effects of tree species diversity and species mixing with different functional identities on the young tree growth were investigated in the 5th year of the experiment. The results showed that tree growth was not positively correlated with tree species richness. The growth of fast-growing tree species (Pinus massoniana and Mytilaria laosensis) in the monoculture was 2.5-4.5 times of the valuable broadleaved tree species (Castanopsis hystrix and Erythrophleum fordii) monoculture. Tree growth was significantly increased by 51.5%-132.8% in the conifer and broadleaved tree species mixing plantations and in the fast-growing and nitrogen fixation tree species mixing plantations, when two tree species or four tree species were mixed. There was no significant difference in tree growth among different tree species mixed types, when six tree species were mixed. The contents of soil nitrogen, phosphorus and organic matter were the main factors affecting tree growth. The results indicated that young tree growth could be improved through the selecting conifer and broadleaved tree species mixing, fast-growing and nitrogen fixation tree species mixing in south subtropical plantations.


Asunto(s)
Pinus , Árboles , China , Nitrógeno/análisis , Fósforo , Suelo
10.
J Fluoresc ; 21(4): 1599-605, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21274600

RESUMEN

A new 7-nitrobenz-2-oxa-1,3-diazole (NBD) derived fluorescent probe (1) exhibiting high selectivity for Cu(2+) detection, produced significant fluorescence quenching in the presence of Cu(2+) ion, while the metal ions Ca(2+), Cd(2+), Co(2+), Fe(2+), Hg(2+), Mg(2+), Mn(2+), Ni(2+) and Zn(2+) produced only minor changes in fluorescence. The apparent association constant (K (a)) for Cu(2+) binding in chemosensor 1 was found to be 1.22 × 10(3) M(-1). The maximum fluorescence quenching activity caused by Cu(2+) binding to 1 was observed over the pH range 6-10.


Asunto(s)
Cobre/análisis , Colorantes Fluorescentes/química , Oxadiazoles/química , Fluorescencia , Colorantes Fluorescentes/síntesis química , Iones/análisis , Estructura Molecular , Oxadiazoles/síntesis química , Espectrometría de Fluorescencia
11.
Sci Rep ; 11(1): 8388, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33863928

RESUMEN

Some interesting phenomena have been observed in the laser reflecting Talbot magnification (LRTM) effect discovered at first, in which the high-order nonlinear imaging and the plasmonic structures imaging occur. The LRTM effect images were obtained on the 1D and 2D photonic crystals fabricated by using nanosecond pulsed laser etching on silicon surface, where the high-order nonlinear imaging on the 1D and 2D photonic crystals was observed interestingly. The theory result is consistent with the experimental one, which exhibits that the suitable wave-front shape of injection beam selected in optical route can effectively enlarge the magnification rate and elevate the resolution of the Talbot image. Especially the periodic plasmonic structures on silicon surface have been observed in the LRTM effect images, which have a good application in the online detection of pulsed laser etching process. The temporary reflecting Talbot images exhibit that the electrons following with photonic frequency float on plasma surface to form electronic crystal observed on silicon at first, which is similar with the Wigner crystal structure.

12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(10): 2758-61, 2010 Oct.
Artículo en Zh | MEDLINE | ID: mdl-21137415

RESUMEN

NDVI based on NOAA/AVHRR from 1982 to 2003 are used to monitor variable rules for the growing season in spring of vegetation in the north-south transect of eastern China (NSTEC). The following, mainly, are included: (1) The changing speed of greenness period in spring of most regions in NSTEC is slow and correlation with the year is not distinct; (2) The regions in which greenness period in spring distinctly change mainly presented an advance; (3) The regions in which inter-annual fluctuation of greenness period in spring is over 10 days were found in 3 kinds of areas: the area covered with agricultural vegetation types; the areas covered with evergreen vegetation types; the areas covered with steppe vegetation types; (4) changes of vegetation greenness period in spring have spatio-temporal patterns.


Asunto(s)
Agricultura , Estaciones del Año , China , Monitoreo del Ambiente/métodos , Plantas , Análisis Espacio-Temporal
13.
Ultrasound Med Biol ; 46(3): 582-588, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31917043

RESUMEN

We aimed to evaluate whether subcapsular injection of ultrasonic contrast agent (UCA) can distinguish between benign and malignant lymph node (LN) lesions exhibiting homogeneous enhancement in intravenous contrast-enhanced ultrasound (CEUS) images. From November 2012 to July 2015, 32 patients with superficial lymphadenopathy exhibiting homogeneous enhancement after intravenous CEUS were enrolled. A small amount of UCA was injected into LNs using a subcapsular approach, and perfusion characteristics were recorded. Using the pathology identified via core needle biopsy as the gold standard, we calculated the sensitivity, specificity and accuracy of the technique in terms of distinguishing between benign and malignant LN lesions. Pathology revealed 23 cases of true benign and 9 cases of true malignant LN lesions; the former included 2 cases of tuberculosis and 21 cases of reactive hyperplasia, and the latter included 7 lymphomas and 2 metastases. Subcapsular CEUS diagnosed 24 benign and 8 malignant LN lesions. Most lymphomas (6 of 7, 85.7%) exhibited heterogeneous perfusion, with lymphatic tract distortion in the absence of interruption. Reactive hyperplasia LNs manifested as diffuse homogeneous or brush-like perfusion from the subcapsular region to the center, without lymphatic tract distortion. Metastatic LNs had lymphatic tract interruptions. The sensitivity, specificity, consistency and positive and negative predictive values were 77.8%, 95.6%, 90.6%, 87.5% and 91.7%, respectively. For LNs exhibiting uniform enhancement in intravenous CEUS imaging, subcapsular CEUS may help to distinguish between benign and malignant lesions. In particular, lymphatic distortion without interruption may specifically indicate a lymphoma.


Asunto(s)
Medios de Contraste/administración & dosificación , Ganglios Linfáticos/diagnóstico por imagen , Linfadenopatía/diagnóstico por imagen , Metástasis Linfática/diagnóstico por imagen , Adulto , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Inyecciones Intralesiones , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Ultrasonografía/métodos , Adulto Joven
14.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1494-1502, 2019 May.
Artículo en Zh | MEDLINE | ID: mdl-31107004

RESUMEN

To better understand the eco-physiological characteristics of dominant tree species in Korean pine broad-leaved forests, and to provide fundamental data for modelling and predicting carbon dynamics of forest ecosystems, we measured leaf CO2 assimilation rate versus intercellular CO2 concentration curves of four canopy dominant tree species in a Korean pine broad-leaved forest, in situ, for the first time, using a canopy crane in the Changbai Mountain Forest Ecosystem Research Station. Several important photosynthetic parameters were fitted with the FvCB model. Photosynthe-tic rate (A), maximum carboxylation rate (Vc max) and stomatal conductance (gs) were lowest in Pinus koraiensis (Pk), while stomatal limitation on photosynthesis (Ls) was highest in Pk. There were significant variations of photosynthetic characteristics among the three broad-leaved tree species [i.e., Fraxinus mandshurica (Fm), Quercus mongolica (Qm) and Tilia amurensis (Ta)]. The rank of tree species with respect to area-based Vc max was: Fm (83.2 µmol·m-2·s-1) and Qm (89.3 µmol·m-2·s-1) > Ta (68.4 µmol·m-2·s-1) and Pk (68.8 µmol·m-2·s-1) (P<0.05), and their rank with respect to mass-based Vc max was: Fm (1.36 µmol·g-1·s-1) > Qm (1.03 µmol·g-1·s-1) > Ta (0.90 µmol·g-1·s-1) > Pk (0.42 µmol·g-1·s-1) (P<0.05). From July to September, A value significantly declined in Fm and Qm, but remained stable in Ta and Pk. By contrast, Vc max significantly decreased in all tree species from July to September. Our results indicated that seasonal variation of Vcmax should be taken into consideration in the modelling and predicting of forest ecosystem carbon dynamics in northeastern China.


Asunto(s)
Pinus , Árboles , China , Bosques , Fotosíntesis
15.
Technol Cancer Res Treat ; 18: 1533033819857767, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31390948

RESUMEN

PURPOSE: To develop a fusion imaging system that combines ultrasound and computed tomography for real-time tumor tracking and to validate the accuracy of performing registration via this approach during a specific breathing phase. MATERIALS AND METHODS: The initial part of the experimental study was performed using iodized oil injection in pig livers and was focused on determining the accuracy of registration. Eight points (A1-4 and B1-4) at different positions and with different target sizes were selected as target points. During respiratory motion, we used our self-designed system to perform the procedure either with (experimental group, E) or without (control group, C) the respiratory monitoring module. The registration errors were then compared between the 2 groups and within group E. The second part of this study was designed as a preliminary clinical study and was performed in 18 patients. Screening was performed to determine the combination of points on the body surface that provided the highest sensitivity to respiratory motion. Registration was performed either with (group E) or without (group C) the respiratory monitoring module. Registration errors were compared between the 2 groups. RESULTS: In part 1 of this study, there were fewer registration errors at each point in group E than at the corresponding points in group C (P < .01). In group E, there were more registration errors at points A1 and B1 than at the other points (P < .05). There was no significant difference in registration errors among the remaining points. During part 2 of the study, there was a significant difference in the registration errors between the 2 groups (P < .01). CONCLUSIONS: Real-time fusion registration is feasible and can be accurately performed during respiratory motions when using this system.


Asunto(s)
Neoplasias Hepáticas/diagnóstico por imagen , Hígado/diagnóstico por imagen , Imagen Multimodal/métodos , Respiración/efectos de los fármacos , Animales , Humanos , Aceite Yodado/farmacología , Neoplasias Hepáticas/fisiopatología , Masculino , Persona de Mediana Edad , Porcinos , Tomografía Computarizada por Rayos X , Ultrasonografía
16.
J Integr Plant Biol ; 50(2): 210-20, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18713444

RESUMEN

Both the photosynthetic light curves and CO(2) curves of Juglans regia L. and Ziziphus jujuba Mill. var. spinosa in three seasons were measured using a LI-6400 portable photosynthesis system. The maximal net photosynthetic rate (A(max)), apparent quantum efficiency(phi), maximal carboxylation rate (V(cmax)) and water use efficiency (WUE) of the two species were calculated based on the curves. The results showed that A(max) of J. regia reached its maximum at the late-season, while the highest values of A(max) of Z. jujuba occurred at the mid-season. The A(max) of J. regia was more affected by relative humidity (RH) of the atmosphere, while that of Z. jujuba was more affected by the air temperature. Light saturation point (LSP) and Light compensation point (LCP) of J. regia had a higher correlation with RH of the atmosphere, those of Z. jujuba, however, had a higher correlation with air temperature. V(cmax) of both J. regia and Z. jujuba had negative correlation with RH of the atmosphere. WUE of J. regia would decrease with the rise of the air temperature while that of Z. jujuba increased. Thus it could be seen that RH, temperature and soil moisture had main effect on photosynthesis and WUE of J. regia and Z. jujuba. Incorporating data on the physiological differences among tree species into forest carbon models will greatly improve our ability to predict alterations to the forest carbon budgets under various environmental scenarios such as global climate change, or with differing species composition.


Asunto(s)
Ambiente , Juglans/fisiología , Fotosíntesis , Estaciones del Año , Agua/metabolismo , Ziziphus/fisiología , Dióxido de Carbono/metabolismo , Juglans/efectos de la radiación , Luz , Fotosíntesis/efectos de la radiación , Transpiración de Plantas/efectos de la radiación , Análisis de Regresión , Ziziphus/efectos de la radiación
17.
Ying Yong Sheng Tai Xue Bao ; 29(6): 1779-1786, 2018 Jun.
Artículo en Zh | MEDLINE | ID: mdl-29974685

RESUMEN

To examine the effects of altered precipitation pattern on the mechanism of forest soil carbon (C) emission under climate change scenarios, we established plots with 50% reduction in throughfall in a subtropical Pinus massoniana plantation. The effects of throughfall reduction on the mineralization of both soil and aggregate-associated organic C were quantified by laboratory incubation at constant temperature. The results showed that the cumulative mineralization of organic C in the 1-2 mm aggregates was higher than that in other sizes of aggregates. In the dry and wet seasons, the surface soil water content in the throughfall reduction plots was 82.1% and 82.7% of that in the control, but the mass fractions of 0.106-0.25 mm soil aggregates in the throughfall reduction plots increased by 1.8% and 4.2% than the control, respectively. The throughfall reduction treatment significantly reduced the mineralization rate of labile C pools (k1) of soil and micro-aggregates in the dry season, increased the mineralization rate of recalcitrant C pool (k2) of soil and <1 mm aggregates, and had no significant effects on the cumulative mineralization of soil organic C. Results from the correlation analyses revealed significant and positive correlations between k1 of soil and that of the micro-aggregates and between k2 of soil and that of the 0.25-1 mm aggregates. Under the influence of aggregate structure, water condition and soil organic carbon content, the throughfall reduction suppressed the mineralization of labile organic C while stimulated that of recalcitrant organic C.


Asunto(s)
Carbono/análisis , Pinus , Suelo/química , Agricultura , Bosques , Temperatura
18.
Ying Yong Sheng Tai Xue Bao ; 29(7): 2330-2338, 2018 Jul.
Artículo en Zh | MEDLINE | ID: mdl-30039672

RESUMEN

To better predict and evaluate responses of tree growth and forest productivity to the changes of precipitation pattern and seasonal drought under global climate change scenarios, throughfall reduction experiments including 50% of throughfall and natural rainfall (control) treatments were conducted in Castanopsis hystrix and Pinus massoniana plantations of warm subtropical region over a three-year period (2015-2017). Diameter at breast height (DBH), litterfall production and leaf area index of both plantations were investigated, respectively. The results showed that throughfall reduction resulted in a 31.8% decrease of annual increment of DBH of C. hystrix in 2017 and had no significant impact on that of P. massoniana. Leaf area index under throughfall reduction decreased by 8.8% in C. hystrix plantation and decreased by 7.2% or remained unchanged in P. massoniana plantation. Branch litterfall in 2015 and total litterfall in 2017 of C. hystrix increased by 29.6% and 35.8% by throughfall reduction, but leaf litterfall of other tree species (except for P. massoniana) in P. massoniana plantation declined by 50.7% in 2015, with no significant difference for other litterfall components. In conclusion, throughfall reduction had consequences of drought stress in both C. hystrix and P. massoniana plantations, with inter-annual variation and inter-specific differences.


Asunto(s)
Cambio Climático , Sequías , Fagaceae/crecimiento & desarrollo , Pinus/crecimiento & desarrollo , Animales , China , Bosques , Lluvia , Suelo
19.
Ying Yong Sheng Tai Xue Bao ; 29(6): 1753-1758, 2018 Jun.
Artículo en Zh | MEDLINE | ID: mdl-29974682

RESUMEN

Soil microbial residues are important components of soil stable carbon (C) pools. How N-fixing tree species influence microbial residues in soil aggregates in larch plantations is still unclear. To determine the effects of N-fixing tree species on the distribution of microbial residues in different aggregates, we compared the distribution of amino sugars, biomarker of microbial residues, among aggregates in a pure larch (Larix kaempferi) plantation and a mixed plantation of larch (Larix kaempferi) and alder (Alnus sibirica) in eastern Liaoning Province. The results showed that alder did not affect the distribution of amino sugars, but significantly increased amino sugars content in soil aggregates. The total amino sugars in different soil aggregates were enriched by 130%-170% in the mixed larch plantation compared with those in pure larch plantation. The contributions of glucosamine, galactosamine and muramic acid to the increases of total amino sugars caused by alder introduction were 66.5%-66.9%, 30.0%-30.6% and 2.5%-3.2%, respectively. Alder introduction significantly accelerated the glucosamine/muramic acid ratios in >2000 µm and <250 µm aggregates, but not in 250-2000 µm aggregates. Moreover, alder introduction increased the microbial contribution to soil organic C in all aggregates, but did not influence this contribution among aggregates, indicating that the effects of alder introduction on microbial contribution to aggregates were homogeneous.


Asunto(s)
Alnus/fisiología , Amino Azúcares/metabolismo , Amino Azúcares/fisiología , Fijación del Nitrógeno , Microbiología del Suelo , Carbono , China , Larix , Suelo , Azúcares , Árboles
20.
Sci Rep ; 7(1): 7221, 2017 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-28775274

RESUMEN

We have fabricated the multiple nanolayers impuritied on silicon pillars for Si solar cells to pick up photons in ultraviolet and infrared region of solar spectra, in which the localized states originated from nanosilicon doped with oxygen are built to avoid Auger recombination, and some interesting quantum phenomena in the localized states have been observed. The quantum effect of photo-generated carriers has been observed in I-V curve measurement on the photovoltaic sample prepared in oxygen by using nanosecond pulsed laser. More interesting, the twin states of quantum vibration are measured in the localized states originated from the impuritied nanosilicon, which provides a stable reservoir for electrons in the photovaltaic system. It should be noted that the amplitude change of the quantum vibration occurs under magnetic field with 0.33T on the sample prepared in oxygen, owing to the electron spin in the localized states. The photoluminescence (PL) spectra measured from 300 nm to 1700 nm exhibit the localized states in various regions in the photovoltaic system, in which the electrons can stand in the localized states with longer lifetime to be uneasy into Auger recombination.

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