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1.
Acta Crystallogr C Struct Chem ; 75(Pt 2): 213-220, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30720461

RESUMO

For the first time, a new langbeinite-type phosphate, namely potassium terbium tantalum tris(phosphate), K2Tb1.5Ta0.5(PO4)3, has been prepared successfully using a high-temperature flux method and has been structurally characterized by single-crystal X-ray diffraction. The results show that its structure can be described as a three-dimensional open framework of [Tb1.5Ta0.5(PO4)3]∞ interconnected by K+ ions. The TbIII and TaV cations in the structure are disordered and occupy the same crystallographic sites. The IR spectrum, the UV-Vis spectrum, the morphology and the Eu3+-activated photoluminescence spectroscopic properties were studied. A series of Eu3+-doped phosphors, i.e. K2Tb1.5-xTa0.5(PO4)3:xEu3+ (x = 0.01, 0.03, 0.05, 0.07, 0.10), were prepared via a solid-state reaction and the photoluminescence properties were studied. The results show that under near-UV excitation, the luminescence colour can be tuned from green through yellow to red by simply adjusting the Eu3+ concentration from 0 to 0.1, because of the efficient Tb3+→Eu3+ energy-transfer mechanism.

2.
Ying Yong Sheng Tai Xue Bao ; 29(5): 1660-1666, 2018 May.
Artigo em Chinês | MEDLINE | ID: mdl-29797900

RESUMO

To clarify the effects of protease inhibitors on the activities of midgut proteases in Callosobruchus chinensis (L.) larvae, the inhibitory effects of four kinds of protease inhibitors on the activities of midgut proteases of C. chinensis larvae were examined in vitro and in feeding conditions with indoor artificial insect inoculation. The activities of total protease, trypsin-like enzyme and chymotrypsin-like enzyme in the midgut of C. chinensis larvae fed on artificial mung bean that contained different contents of mung bean types in inhibitor (MBTI) were examined. The results showed that those four protease inhibitors had significant inhibitory effects on the activities of total protease, trypsin-like enzyme and chymotrypsin-like enzyme in C. chinensis larvae. The inhibitory effect was more significant when the concentration was higher. Among those inhibitors, the inhibitory effect of 20 µg·mL-1 MBTI on three kinds of enzyme activities was the strongest, with reduction of 62.5%, 41.2% and 38.7%, respectively. Ovomucoid inhibitor (OI) had the lowest inhibitory effect. The activities of three enzymes in the midgut were also inhibited by C. chinensis larvae fed with artificial mung bean containing different inhibitors. The activities of three enzymes increased with the prolongation of the instar after feeding, but they were significantly lower than that in control. The inhibitory effect of MBTI was the strongest. The inhibitory effect on the activities of total protease and trypsin-like enzyme was gradually enhanced with the increases of MBTI contents when C. chinensis larvae were fed with artificial mung bean with different contents MBTI. The inhibitory effect on chymotrypsin-like enzyme activity was not significant. When the content of MBTI was up to 20%, the activity of chymotrypsin-like enzyme was obviously inhibited.


Assuntos
Besouros/enzimologia , Sistema Digestório/enzimologia , Peptídeo Hidrolases/metabolismo , Animais , Larva , Inibidores de Proteases , Tripsina
3.
Inorg Chem ; 57(3): 1455-1463, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29308885

RESUMO

By functionalization of the achiral carboxylate-based pyridine-N ligand 2,2'-bipyridine-3,3'-dicarboxylate (H2bpda) with N-oxide groups, the axially chiral ligand 2,2'-bipyridine-3,3'-dicarboxylate 1,1'-dioxide (H2bpdado) has been obtained. On the basis of H2bpdado and auxiliary N-donor ligands, two isostructural 3D dynamic porous Cu(II) metal-organic frameworks (MOFs), {[Cu0.5(bpdado)0.5(L)0.5]·3H2O}n (L = 1,2-bis(4-pyridyl)ethane (bpa), trans-1,2-bis(4-pyridyl)ethene (bpe) for 1 and 2, respectively), have been synthesized, which contain N-oxide "open donor sites" (ODSs) and carboxyl sites on the pore surfaces. The modification of pyridine-N into the N-oxide group not only transforms the nonporous structure into a porous framework but also endows the N-oxide group with unique charge-separated plus electron-rich character, which may provide an enhanced affinity toward CO2 molecules. Interestingly, both 1 and 2 present reversible structural transformation upon dehydration and rehydration. The adsorption properties of 1 and 2 have been investigated by N2, H2, CH4, and CO2 gases, and they reveal evident adsorption for CO2 and CH4. Both MOFs have high CO2 uptake, CO2 sorption affinity, and sorption selectivities of CO2 over CH4 and N2. Remarkably, 1' and 2' exhibit intriguingly comparable temperature-dependent CO2 sorption behaviors that can probably be attributed to the difference in bpa and bpe. First, at 195 K, 1' and 2' exhibit stepwise adsorption and hysteretic desorption behavior for CO2, but in the second step, the isotherms of 2' display a starting pressure greater than that of 1'. Then, at 298 K, their CO2 isotherms all show nonclassical type I adsorption, while peculiarly, at 273 K, the CO2 isotherm of 1' still exhibits uncommon stepwise adsorption but that of 2' does not. Thus, these temperature-dependent CO2 sorption behaviors indicate that there exist different threshold temperatures and pressures of channel expansion for 1' and 2'.

4.
Gene ; 518(2): 360-7, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23333605

RESUMO

Farnesyl pyrophosphate synthase (FPPS EC 2.5.1.10) catalyzes the production of farnesyl pyrophosphate (FPP), which is a key precursor for many sesquiterpenoids such as floral scent and defense volatiles against herbivore attack. Here we report a new full-length cDNA encoding farnesyl diphosphate synthase from Hedychium coronarium. The open reading frame for full-length HcFPPS encodes a protein of 356 amino acids, which is 1068 nucleotides long with calculated molecular mass of 40.7 kDa. Phylogenetic tree analysis indicates that HcFPPS belongs to the plant FPPS super-family and has strong relationship with FPPS from Musa acuminata. Expression of the HcFPPS gene in Escherichia coli yielded FPPS activity. Tissue-specific and developmental analyses of the HcFPPS mRNA and corresponding volatile sesquiterpenoid levels in H. coronarium flowers revealed that the HcFPPS might play a regulatory role in floral volatile sesquiterpenoid biosynthesis. The emission of the FPP-derived volatile terpenoid correlates with strong expression of HcFPPS induced by mechanical wounding and Udaspes folus-damage in leaves, which suggests that HcFPPS may have an important ecological function in H. coronarium vegetative organ.


Assuntos
Regulação da Expressão Gênica de Plantas , Geraniltranstransferase/genética , Sesquiterpenos/metabolismo , Zingiberaceae/enzimologia , Zingiberaceae/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Flores/genética , Flores/metabolismo , Geraniltranstransferase/metabolismo , Herbivoria , Dados de Sequência Molecular , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fosfatos de Poli-Isoprenil/biossíntese , RNA Mensageiro/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Zingiberaceae/metabolismo
6.
Exp Ther Med ; 2(5): 977-984, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22977608

RESUMO

The aim of the present study was to investigate the effects of glucocorticoids (GCs) on appetite and gene expression of the hypothalamic appetite regulatory peptides, neuropeptide Y (NPY), agouti-related protein (AGRP) and cocaine and amphetamine-regulated transcript (CART), in non-obese and obese rats. Both non-obese and obese rats were randomly assigned to three groups: normal saline, low- and high-dose GC groups (NSG, LDG and HDG, respectively), which received an intraperitoneal injection with normal saline (0.2 ml/100 g) or hydrocortisone sodium succinate at 5 and 15 mg/kg, respectively, for 20 days. The expression levels of NPY, AGRP and CART mRNA in the hypothalamus were measured by real-time quantitative PCR. Non-obese and obese rats were found to undergo weight loss after GC injection, and a higher degree of weight loss was observed in the HDG rats. The average and cumulative food intakes in the obese and non-obese rats injected with high-dose GC were lower compared to that in the NSG (p<0.05). mRNA expression levels of the orexigenic neuropeptides, NPY and AGRP, and the anorexigenic neuropeptide, CART, were significantly lower in the HDG than levels in the NSG for both the obese and non-obese rats (p<0.05). GC treatment decreased appetite and body weight, induced apparent glucolipid metabolic disturbances and hyperinsulinemia, while down-regulated mRNA expression levels of the orexigenic neuropeptides, NPY and AGRP, and anorexigenic neuropeptide, CART, in the hypothalamus in the rats. The mechanism which induces this neuropeptide expression requires further study.

7.
Steroids ; 75(12): 853-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20471407

RESUMO

OBJECTIVE: Accumulating evidence suggests that adiponectin plays an important role in the genesis of obesity and insulin resistance. Although it has been shown that glucocortocoids (GC) inhibit adiponectin expression in vitro, there exist discrepant results in vivo. In this study, we observe the effect of GC on the serum adiponectin level and adiponectin expression in white adipose tissue (WAT) in male SD rats. METHODS: An obese rat model was made by a high-fat diet. Both non-obese and obese rats were randomly divided into normal saline (intraperitoneal injection with normal saline 0.2ml/100gday for 20 days, NS), a low dose GC group (intraperitoneal injection with hydrocortisone sodium succinate 5mg/kgday for 20 days, LDG) and a high dose GC group, respectively (intraperitoneal injection with hydrocortisone sodium succinate 15mg/kgday for 20 days, HDG). Serum adiponectin levels were detected by ELISA and the adiponectin mRNA level was assayed by Northern blot. RESULTS: The serum adiponectin level significantly decreased after 80 days of the high-fat diet (P<0.05), while it was not decreased after 80 days of the chow diet (P>0.05). The serum adioponectin levels in both the non-obese and obese rats were significantly decreased after a 20-day GC injection period (P<0.01). The adiponectin mRNA levels in epididymal fat after high dose GC injection, in both non-obese and obese rats were also decreased (P<0.001). CONCLUSIONS: A high-fat diet decreased serum adiponectin levels in the rat. GC decreased serum adiponectin levels, and this might be due to inhibited adiponectin mRNA expression in WAT. High-fat diet and GC have a synergistic effect on inhibiting adiponectin expression in rats.


Assuntos
Adipócitos Brancos/efeitos dos fármacos , Adipócitos Brancos/metabolismo , Adiponectina/sangue , Adiponectina/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hidrocortisona/análogos & derivados , Animais , Peso Corporal/efeitos dos fármacos , Cruzamento , Gorduras na Dieta/efeitos adversos , Hidrocortisona/farmacologia , Masculino , Obesidade/sangue , Obesidade/etiologia , Obesidade/genética , Obesidade/fisiopatologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(7): 1777-80, 2009 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-19798938

RESUMO

A noval all fiber optic Fourier transform spectrometer based on single mode fiber Mach-Zehnder interferometer is reported. The authors designed a piezoelectric optical phase modulator with two centimeter scan scale, which was used to replace the moving mirror of traditonal Fourier transform spectrometer. The 1 310 nm DFB laser was used as reference light source to make equal interval sampling of test light source's interferogram, and to eliminate errors of nonlinear modulation. Through making the inverse Fourier transform to test light source's interferogram, the authors obtained the spectrum of test source. The spectrum of ASE broadband light source was measured by FFTS system, and the experiment result agrees with that tested by grating spectrometer. Finally, the authors utilized fiber grating as sample to measure the resolution of FFTS system, and the spectral resolution is 0.78 cm(-1).

9.
Artigo em Chinês | MEDLINE | ID: mdl-15599032

RESUMO

Effects of phosphorus deficiency on alternative respiratory pathway and its relation with O(-.)(2) production were investigated in two lines of suspension-cultured tobacco cells which have different tolerances to P deficiency. Oxford cells were shown to be much more tolerant than K326. There were no apparent differences in inorganic and total phosphorous content between the two cell lines. The capacity and activity of alternative respiratory pathway were decreased by P deficiency in K326 cells but were little influenced in Oxford cells. Under either P-deficient or sufficient condition, the capacity and activity of alternative respiratory pathway were always higher in Oxford than in K326. When mitochondria were isolated and used for the same study, similar results were obtained as described above. The expression of AOX at protein level was induced by P deficiency in both lines to similar extents. O(-.)(2) content in K326 cells was significantly higher under P deficiency but little affected in Oxford. It is suggested that alternative respiratory pathway may be associated with tolerance of tobacco cells to P deficiency and may play a role in scavenging reactive oxygen species.


Assuntos
Consumo de Oxigênio , Fósforo/deficiência , Tabaco/metabolismo , Divisão Celular , Proteínas Mitocondriais , Oxirredutases/análise , Fósforo/análise , Proteínas de Plantas , Superóxidos/metabolismo , Suspensões , Tabaco/citologia
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