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1.
J Med Chem ; 67(14): 12055-12067, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38959380

RESUMEN

PCSK9 has been recognized as an efficient target for hyperlipidemia and related cardiovascular/cerebrovascular diseases. However, PCSK9 inhibitors in the clinic are all biological products, and no small molecules are available yet. In the current work, we discovered that the crude extract of Euphorbia esula (E. esula) promoted LDL uptake in vitro and then obtained 8 new and 12 known jatrophane diterpenoids by activity-guided isolation. After summarized their structure-activity relationship of PCSK9 inhibition, we selected compound 11 (C11) with potent activity and high abundance to investigate its mechanism and in vivo efficacy. Mechanistically, C11 bound with HNF1α to influence its nuclear distribution and subsequently inhibit PCSK9 transcription, thereby enhancing LDLR and promoting LDL uptake. Moreover, C11 demonstrated obvious lipid-lowering activity in HFD mouse model. In conclusion, we first revealed the novel application of E. esula in the discovery of a lipid-lowering candidate and highlighted the potential of C11 in the treatment of hyperlipidemia.


Asunto(s)
Diterpenos , Euphorbia , Proproteína Convertasa 9 , Euphorbia/química , Diterpenos/farmacología , Diterpenos/química , Diterpenos/aislamiento & purificación , Animales , Proproteína Convertasa 9/metabolismo , Proproteína Convertasa 9/genética , Humanos , Ratones , Relación Estructura-Actividad , Masculino , Hiperlipidemias/tratamiento farmacológico , Hiperlipidemias/metabolismo , Células Hep G2 , Ratones Endogámicos C57BL , Transcripción Genética/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Inhibidores de PCSK9
2.
Int J Biol Macromol ; 275(Pt 1): 133425, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38936582

RESUMEN

Yeast ß-glucan (BYG) possesses extremely low solubility that has limited its applications. In this study, we hydrolyzed BYG using snail enzyme to obtain hydrolyzed yeast ß-glucan (HBYG) with desirable water solubility and hypoglycemic activity. On the basis of HBYG, HBYG­chromium(III) complex (HBYG-Cr) was synthesized. The molecular weight of the complex was 4.41 × 104 Da, and the content of trivalent chromium was 8.95 %. The hydroxyl groups of HBYG participated in the coordination and formed the chromium complex. The space conformations of HBYG exhibited remarkable changes after complex formation. HBYG-Cr existed mainly in an amorphous state and presented good dispersibility, and the surface was uneven. The hypoglycemic activity of HBYG-Cr was studied in db/db and C57 mice. The results showed that HBYG-Cr had good hypoglycemic activity. Histopathological studies demonstrated that the liver, kidney, pancreas, and skeletal muscle in the treatment group were significantly improved compared with those in the diabetic model group. The sub-acute toxicity of HBYG-Cr was studied in KM mice and the results indicated that the complex did not cause adverse reactions or toxic side effects. This study broadened the application of yeast ß-glucan and provided an important reference for the development of hypoglycemic functional foods and drugs.


Asunto(s)
Cromo , Hipoglucemiantes , beta-Glucanos , Animales , beta-Glucanos/química , beta-Glucanos/farmacología , Hipoglucemiantes/farmacología , Hipoglucemiantes/química , Cromo/química , Cromo/toxicidad , Ratones , Hidrólisis , Diabetes Mellitus Experimental/tratamiento farmacológico , Masculino , Saccharomyces cerevisiae/efectos de los fármacos , Glucemia/efectos de los fármacos , Solubilidad
3.
ACS Appl Mater Interfaces ; 16(11): 14072-14081, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38442356

RESUMEN

Conventional luminescent solar concentrators (LSCs) usually only have the ability to absorb solar energy and convert it to electricity but are not able to regulate the transmitted light. Herein, a multistate thermoresponsive smart window (SW) based on LSC has been fabricated, in which the stimuli-responsive host layer consists of polydimethylsiloxane (PDMS) and ethylene glycol solution (EGS) microdroplets stacking with LSC layer-based on near-infrared (NIR) CuInSe2-xSx/ZnS core/shell quantum dots (QDs) and PDMS matrix. As-synthesized CISSe/ZnS QDs with broad NIR absorption in LSC exhibit controllable emission spectra over 833-1088 nm and high photoluminescence (PL) quantum yield from 45 to 83%. Coupling with Si solar cells as a reference, optimized LSC-SW devices with dimensions of 5 × 5 × 0.9 cm3 exhibit higher power conversion efficiency (PCE) of 1.19-1.36% with increased temperature from 0 to 50 °C than those of sole LSC and SW devices. The corresponding visible light transmissions are regulated from 75.1 to 48.1% accordingly. The improvement of PCEs in an opaque state is mainly due to enhanced absorption of QDs originating from rescattered photons from the EGS/PDMS layer, leading to more emitted photons reaching photovoltaics. This work is expected to bring up new opportunities for applications in greenhouses, building facades, and energy-efficient smart windows.

4.
Nat Prod Res ; 37(4): 571-578, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35616360

RESUMEN

Five new glycosylated phenolic derivatives, rotundosides A-E (1-5), and three known glycosides (6-8) were isolated from the 95% alcohol extract of the bark of Ilex rotunda. Their structures were elucidated by extensive spectroscopic analysis and comparison with the literature data. All new compounds possessed a [5-O-(E)-caffeoyl]-ß-D-apiofuranosyl-(1→6)-ß-D-glucopyranosyl group. The anti-inflammatory properties of all isolated compounds were evaluated using a modified nitric oxide (NO) production in lipopolysaccharide (LPS)-induced leukemia cells in mouse macrophage (RAW264.7) method. Compound 8, dracunculifoside H, showed significant anti-inflammatory activity in vitro.


Asunto(s)
Ilex , Ratones , Animales , Estructura Molecular , Ilex/química , Corteza de la Planta/química , Glicósidos/química , Antiinflamatorios/química , Fenoles/análisis
5.
Adv Mater ; 35(5): e2206574, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36056776

RESUMEN

Semitransparent perovskite solar cells (ST-PSCs) are ideal candidates for building-integrated photovoltaics (BIPV) and tandem solar cells (TSCs) owing to their tunable bandgap and high visible transparency. The best power conversion efficiency (PCE) of ST-PSCs is close to 15% with an average visible transmittance of over 20%, which still lags far behind the PCE of normal opaque PSCs. This can be attributed to the poor light utilization efficiency (LUE) of ST-PSCs. Herein, the pivotal routes for maximizing LUE of ST-PSCs in terms of photon propagation management and carrier kinetics regulation are systematically rationalized. First, the fundamental theoretical analyses on optical processes and electronic properties are provided. Then, insights on photon propagation management measures and carrier kinetics regulation strategies are provided. Furthermore, a summary of the promising commercial application of ST-PSCs in BIPV and TSCs is provided. Finally, the main progress of ST-PSCs is briefly summarized, and the directions for the commercialization of ST-PSCs are proposed.

6.
J Nat Prod ; 85(5): 1294-1303, 2022 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-35561431

RESUMEN

Seven new hexasaccharide resin glycosides, named calysepins I-VII (1-7), with 27-membered rings, were obtained from the aerial parts of Calystegia sepium. Their structures with absolute configuration were established on the basis of spectroscopic data interpretation analysis and the use of chemical methods. They were defined as hexasaccharides composed of one d-quinovose, four d-glucose, and one l-rhamnose unit, and their sugar moieties were partially acylated by (2S)-methylbutanoic acid in 1-7 and (2R,3R)-nilic acid in 1-5 and 7, which mainly differed at the positions of acylation. Additionally, calysepin IV (4) exhibited cytotoxicity against A549 cells with an IC50 value of 5.2 µM.


Asunto(s)
Antineoplásicos , Calystegia , Convolvulus , Calystegia/química , Glicósidos/química , Glicósidos/farmacología , Estructura Molecular , Resinas de Plantas/química
7.
RSC Adv ; 11(12): 7025-7036, 2021 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-35423197

RESUMEN

We investigated the short- and medium-range structural features of sodium aluminosilicate glasses with various P2O5 (0-7 mol%) content and Al/Na ratios ranging from 0.667 to 2.000 by using molecular dynamics simulations. The local environment evolution of network former cations (Si, Al, P) and the extent of clustering behavior of modifiers (Na+) is determined through pair distribution function (PDF), total correlation function (TDF), coordination number (CN), Q x n distribution and oxygen speciation analysis. We show that Al-O-P and Si-O-Al linkage is preferred over other connections as compared to a random model and that Si-O-Si linkage is promoted by the P2O5 addition, which is related to structural heterogeneity and generates well-separated silicon-rich and aluminum-phosphorus-rich regions. Meanwhile, due to the relatively high propensity of Al to both Si and P, heterogeneity can be partly overcome with high Al content. A small amount of Si-O-P linkages have been detected at the interface of separated regions. Clustering of Na+ is also observed and intensified with the addition of P2O5. Based on the simulated structural information, a modified random network model for P2O5-bearing sodium aluminosilicate glass has been proposed, which could be useful to optimize the mobility of sodium ions and design novel functional glass compositions.

8.
ACS Appl Mater Interfaces ; 12(4): 4366-4372, 2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-31867946

RESUMEN

A hybrid Li-air battery uses a protected lithium anode and a porous air cathode in an aqueous electrolyte, based on a 4-e oxygen reduction reaction/oxygen evolution reaction (ORR/OER). It avoids the insoluble and insulating Li2O2 product in a typical nonaqueous Li-air battery, and it owns unique advantages. A bifunctional cathode catalyst is crucial to battery performance. Here, we synthesize an ultrathin N-doped graphene-encapsulated nanosphere Co-Ni alloy (Co-Ni@NG). It has hierarchical architecture consisting of a uniform Co-Ni nanoalloy coated with a thin layer of N-doped graphene, showing high activity, high stability, and lower overpotential between the ORR and OER (0.55 V between onset potentials). It exhibited a discharge/charge voltage gap of 0.55 V at a current density of 1.4 mA cm-2, which is much smaller than the commercial Pt/C catalyst. It delivered an energy density of 3158 Wh kg-1 and a power density as high as 134.2 W m-2 at a current density of 7 mA cm-2. The graphene shells protect the alloy catalyst and improve the durability of the catalyst. One hundred cycles were demonstrated without significant deterioration. It was testified as a promising energy storage system with high energy density, efficiency, reliability, and durability.

9.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117381, 2020 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-31412311

RESUMEN

In this work, a novel Ag/AgBr/ZnO SERS substrate was prepared by calcinating spin-coated zinc acetate on glass slides in the presence of ethanolamine (EA), followed by the process of impregnating-precipitation-photoreduction treatment. The SERS performances of Ag/AgBr/ZnO substrates were evaluated using aqueous crystal violet (CV) and Rhodamine 6G (R6G) as target analytes. The effects of initial immersion precursor concentration and irradiation time on the SERS performance were systematically studied. The as-prepared SERS substrate exhibited good chemical detection sensitivity, reproducibility and reusability. The optimal Ag/AgBr/ZnO (10 mM-30 min) substrates were capable of detecting 10-12 M CV and 10-11 M R6G aqueous solutions. The quantitative detection by the SERS substrate was investigated by constructing a linear corresponding calibration plot. The Ag/AgBr/ZnO SERS substrate was regenerated by a simple visible light driven photocatalytic process. A plausible Z-scheme visible light photocatalytic mechanism seems to account for the Ag-ZnO-AgBr system. This SERS substrate can be separated from the reaction easily, and the results indicated that the film was reusable for eight times without significantly losing the SERS efficiency, each time accompanied by a simple photo-driven regeneration. This study reveals that the Ag/AgBr/ZnO film on glass is practically applicable as an ultra-highly sensitive SERS substrate that can be readily regenerated.

10.
Ying Yong Sheng Tai Xue Bao ; 30(9): 2892-2902, 2019 Sep.
Artículo en Chino | MEDLINE | ID: mdl-31529863

RESUMEN

We analyzed the changes of net primary productivity (NPP) and net ecosystem productivity (NEP) of Quercus spp. forest and Robinia pseudoacacia plantation under different future climate scenarios in Shaanxi Province during 2015-2100, using the process-based dynamic vegetation model-LPJ-GUESS. The results showed that compared with the benchmark period (1961-1990), NPP of Quercus spp. forest and R. pseudoacacia plantation in northern Shaanxi would decrease by 4.9%-29.5% and 22.5%-56.2% respectively, while that in Guanzhong and southern Shaanxi would increase by 13.0%-49.0% and 21.3%-62.9% respectively in the future. The NPP of Quercus spp. forest and R. pseudoacacia plantation under the RCP8.5 scenario was the highest, followed by that under the RCP4.5 and RCP2.6 scenarios. Those two types of forest would be carbon sink in three subregions in the future. Quercus spp. forest would have stronger carbon sink function in nor-thern Shaanxi and Guanzhong, while R. pseudoacacia plantation would have stronger carbon sink function in Southern Shaanxi. Under different RCP scenarios, the NEP variation range of R. pseu-doacacia plantation was greater than that of Quercus spp. forest in three subregions.


Asunto(s)
Cambio Climático , Bosques , Secuestro de Carbono , China , Ecosistema
11.
Respir Med Case Rep ; 28: 100896, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31360632

RESUMEN

Patients of clinically amyopathic dermatomyositis associated with rapidly progressive interstitial pneumonia (CADM-RFIP) with positive anti-MDA5 antibody usually presents rapid deterioration and traditional therapy such as cyclophosphamide combined with high-dose prednisone pulse therapy shows no clear benefit at whiles. However, blood purification combined with traditional therapy works according to the literature. We herein report two CADM-RFIP patients administered with DNA immunoadsorption combined with traditional therapy and then reviewed the literature of blood purification in CADM-RFIP patients at home and abroad to date. We emphasize blood purification such as DNA immunoadsorption could apply in the early stage of CADM-RFIP, which can decrease inflammation and allow us more time to control the condition better.

12.
Ying Yong Sheng Tai Xue Bao ; 29(2): 412-420, 2018 Feb.
Artículo en Chino | MEDLINE | ID: mdl-29692054

RESUMEN

This study analyzed the dynamics of net primary productivity (NPP) of Pinus tabuliformis forest under future climate scenarios in Shaanxi Province during 2015-2100, using a dynamic vegetation model (LPJ-GUESS). The results showed that in the 2015-2100 period, annual mean temperature of this region would significantly increase by 0.12, 0.23 and 0.54 ℃·10 a-1 under RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively, while the annual precipitation would have no significant change under climate scenarios except RCP4.5, under which it would significantly increase by 14.36 mm·10 a-1. Compared with the NPP of P. tabuliformis forest in the historical period (1961-1990), it would increase by 1.6%-29.6% in the future period, and the enhancement could reach 45.4% at the end of this century (2071-2100) under RCP8.5 scenario. The NPP under the RCP8.5 scenario was the highest, followed by the RCP4.5 and RCP2.6 scenarios. During 2015-2100, the NPP in the northern Shaanxi region would significantly decrease with the rate of 41.00 and 21.00 g C·m-2·10 a-1 under the RCP2.6 and RCP4.5 scenarios, respectively, implying that this area has the potentiality to be carbon source.


Asunto(s)
Cambio Climático , Pinus , China , Ecosistema , Bosques , Dinámica Poblacional
13.
J Nanosci Nanotechnol ; 18(4): 3012-3017, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29442988

RESUMEN

Silver nanowires with high yield, uniform size and high aspect ratio were successfully synthesized by a simple and effective polyol method under low temperature and quiescent conditions, adopting CuCl2·2H2O as the nucleation control agent for the first time. The synthesized silver nanowires were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectroscopy (DRS). The results indicate that the silver nanowires were composed of face-centered cubic structure of pure metallic silver with high crystallinity. And the silver nanowires have an average length of 80~100 µm and an average diameter of 40~80 nm. Thus, the aspect ratio of the nanowires was greater than 1000. In addition, the influence on the morphology and structure of the silver nanowires were investigated for reaction temperature, mole ratio of PVP:AgNO3, molecular weight of PVP and mole ratio of control agent CuCl2 · 2H2O:AgNO3. Finally, the optimum reaction condition were obtained for the preparation of the silver nanowires with high aspect ratio.

14.
Toxicol Appl Pharmacol ; 309: 111-20, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27507327

RESUMEN

The present study was aimed at exploring the protective effects of Salvianolic acid B (SalB) against paraquat (PQ)-induced lung injury in mice. Lung fibrotic injuries were induced in mice by a single intragastrical administration of 300mg/kg PQ, then the mice were administrated with 200mg/kg, 400mg/kg SalB, 100mg/kg vitamin C (Vit C) and dexamethasone (DXM) for 14days. PQ-triggered structure distortion, collagen overproduction, excessive inflammatory infiltration, pro-inflammatory cytokine release, and oxidative stress damages in lung tissues and mortality of mice were attenuated by SalB in a dose-dependent manner. Furthermore, SalB was noted to enhance the expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and reduce expression of the reactive oxygen species-generating enzyme Nox4 [NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase-4]. SalB also inhibited the increasing expression of transforming growth factor (TGF)-ß1 and the phosphorylation of its downstream target Smad3 which were enhanced by PQ. These results suggest that SalB may exert protective effects against PQ-induced lung injury and pulmonary fibrosis. Its mechanisms involve the mediation of Nrf2/Nox4 redox balance and TGF-ß1/Smad3 signaling.


Asunto(s)
Benzofuranos/farmacología , Herbicidas/toxicidad , Pulmón/efectos de los fármacos , NADPH Oxidasas/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Paraquat/toxicidad , Proteína smad3/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Animales , Mediadores de Inflamación/metabolismo , Pulmón/metabolismo , Pulmón/patología , Masculino , Ratones , NADPH Oxidasa 4 , Oxidación-Reducción , Estrés Oxidativo
15.
Int J Clin Exp Pathol ; 8(9): 11230-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26617847

RESUMEN

Here, we reported two cases of nonspecific interstitial pneumonia overlap organizing pneumonia (NSIP/OP) with lung-dominant connective tissue disease (LD-ILD). The first case is a patient with hands of chapped skin, right-sided pleuritic chest discomfort, weakness, positive ANA and antibodies to Ro/SS-A (+++) and Ro-52 (++). In the second case, there were Reynaud's disease, and nucleolus-ANA increased (1:800). Chest high resolution CT scan in both cases showed ground-glass opacifications, predominantly in basal and subpleural region and the pathologic manifestation were correlated with NSIP/OP, which were previously discovered in Sjogren syndrome, PM/DM and other rheumatic diseases. The two cases of NSIP/OP with LD-CTD we reported expand disease spectrum of NSIP/OP pathological types in ILD. However, it is necessary to process large-scale studies.


Asunto(s)
Enfermedades del Tejido Conjuntivo/patología , Enfermedades Pulmonares Intersticiales/patología , Pulmón/patología , Adulto , Biopsia , Enfermedades del Tejido Conjuntivo/diagnóstico por imagen , Enfermedades del Tejido Conjuntivo/tratamiento farmacológico , Enfermedades del Tejido Conjuntivo/fisiopatología , Femenino , Volumen Espiratorio Forzado , Glucocorticoides/uso terapéutico , Humanos , Pulmón/diagnóstico por imagen , Pulmón/efectos de los fármacos , Pulmón/fisiopatología , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Enfermedades Pulmonares Intersticiales/tratamiento farmacológico , Enfermedades Pulmonares Intersticiales/fisiopatología , Masculino , Metilprednisolona/uso terapéutico , Capacidad de Difusión Pulmonar , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Capacidad Vital , Adulto Joven
16.
Fitoterapia ; 103: 63-70, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25796351

RESUMEN

Nine new lignans (1-8, 13) and five known ones (9-12, 14) have been isolated from the roots of Schisandra sphenanthera and were tested for their capacity to scavenge 2,2-diphenyl-1-Picryl-hydrazyl (DPPH). Of these lignans tested, compounds 1, 7, 8 and 13 exhibited noteworthy antioxidant activity with IC50 values of 92, 115, 35 and 48 µg/mL, respectively. The anti-oxidative haemolysis of human red blood cells (RBCs) activity of the most active compound 8, which is similar to that of vitamin C, was evaluated.


Asunto(s)
Eritrocitos/efectos de los fármacos , Lignanos/química , Raíces de Plantas/química , Schisandra/química , Depuradores de Radicales Libres/química , Hemólisis , Humanos , Concentración 50 Inhibidora , Lignanos/aislamiento & purificación , Estructura Molecular
17.
Eur J Med Chem ; 94: 284-97, 2015 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-25771034

RESUMEN

Several novel series of sesquiterpene mustards (SMs) bearing nitrogen mustard and glutathione (GSH)-reactive α-methylene-γ-butyrolactone groups were successfully prepared for the first time and showed excellent antiproliferative activities in vitro. Among them, compounds 2e and 2g displayed the highest antiproliferative properties with IC50 values ranging from 2.5 to 8.7 µM. The selectivity of these two compounds was evaluated by SRB method against human cancer and normal hepatic cells (HepG2 and L02). The induction of apoptosis and effects on the cell cycle distribution with compounds 2e and 2g were investigated by Hoechst 33,258 staining and flow cytometry, which exhibited that they could induce selective cell apoptosis and cell cycle arrest in HepG2 and L02 cells. In addition, further investigation showed that compounds 2e and 2g could obviously inhibit the proliferation of HepG2 cells by inducing significant DNA cross-linking and depleting GSH in cell media. The good cytotoxicity and selectivity of compounds 2e and 2g pointed them as promising leads for anticancer drug design.


Asunto(s)
Antineoplásicos/farmacología , Diseño de Fármacos , Mecloretamina/química , Mecloretamina/farmacología , Sesquiterpenos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Células HeLa , Células Hep G2 , Humanos , Mecloretamina/síntesis química , Estructura Molecular , Sesquiterpenos/síntesis química , Sesquiterpenos/química , Relación Estructura-Actividad
18.
Ying Yong Sheng Tai Xue Bao ; 25(3): 711-7, 2014 Mar.
Artículo en Chino | MEDLINE | ID: mdl-24984487

RESUMEN

A pot experiment was conducted to study the influences of different NaCl concentrations (0, 50, 100, 200, 400 mmol x L(-1)) on the growth, leaf hydrogen peroxide (H2O2), malonaldehyde (MDA) content, superoxide dismutases (SOD), catalases (CAT), peroxidase (POD), ascorbate peroxidase (APX) enzymes activity, water potential, soluble sugar and proline contents of Nitraria roborowskii. The results showed that the growth of N. roborowskii was not affected at lower NaCl concentrations (< or = 50 mmol L(-1)), while the SOD, POD, CAT and APX activities in leaves of N. roborowskii were increased. However, higher NaCl concentrations (> 50 mmol x L(-1)) restrained the growth parameters of crown area, number of branches, dry mass of leaf, branch and lateral root, and remarkably reduced the SOD, POD and CAT activities, soluble sugar and proline contents in leaves of N. roborowskii. H2O2 and MDA contents in leaves were increased and water potential was reduced with increasing NaCl concentrations.


Asunto(s)
Magnoliopsida/fisiología , Salinidad , Cloruro de Sodio , Estrés Fisiológico , Ascorbato Peroxidasas , Catalasa , Colorantes , Peróxido de Hidrógeno , Magnoliopsida/crecimiento & desarrollo , Malondialdehído , Peroxidasas , Hojas de la Planta/química , Raíces de Plantas , Prolina , Superóxido Dismutasa , Agua
19.
Ying Yong Sheng Tai Xue Bao ; 25(2): 367-73, 2014 Feb.
Artículo en Chino | MEDLINE | ID: mdl-24830234

RESUMEN

This study estimated the spatial distribution of the aboveground biomass of shrubs in the Tianlaochi catchment of Qilian Mountains based on the field survey and remote sensing data. A relationship model of the aboveground biomass and its feasibly measured factors (i. e. , canopy perimeter and plant height) was built. The land use was classified by object-oriented technique with the high resolution image (GeoEye-1) of the study area, and the distribution of shrub coverage was extracted. Then the total aboveground biomass of shrubs in the study area was estimated by the relationship model with the distribution of shrub coverage. The results showed that the aboveground biomass of shrubs in the study area was 1.8 x 10(3) t and the aboveground biomass per unit area was 1598.45 kg x m(-2). The distribution of shrubs mainly was at altitudes of 3000-3700 m, and the aboveground biomass of shrubs on the sunny slope (1.15 x 10(3) t) was higher than that on the shady slope (0.65 x 10(3) t).


Asunto(s)
Ecosistema , Plantas , Altitud , Biomasa , China , Luz , Tecnología de Sensores Remotos , Análisis Espacial
20.
J Phys Chem B ; 118(19): 5177-83, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24779999

RESUMEN

Sodium phosphosilicate glasses exhibit unique properties with mixed network formers, and have various potential applications. However, proper understanding on the network structures and property-oriented methodology based on compositional changes are lacking. In this study, we have developed an extended topological constraint theory and applied it successfully to analyze the composition dependence of glass transition temperature (Tg) and hardness of sodium phosphosilicate glasses. It was found that the hardness and Tg of glasses do not always increase with the content of SiO2, and there exist maximum hardness and Tg at a certain content of SiO2. In particular, a unique glass (20Na2O-17SiO2-63P2O5) exhibits a low glass transition temperature (589 K) but still has relatively high hardness (4.42 GPa) mainly due to the high fraction of highly coordinated network former Si((6)). Because of its convenient forming and manufacturing, such kind of phosphosilicate glasses has a lot of valuable applications in optical fibers, optical amplifiers, biomaterials, and fuel cells. Also, such methodology can be applied to other types of phosphosilicate glasses with similar structures.

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