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1.
BMC Pulm Med ; 19(1): 262, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31878900

RESUMO

BACKGROUND: Our study aimed to verify the prognostic value of circulating tumor cells (CTCs) prior to initial treatment on survival of non-small cell lung cancer (NSCLC) by using meta-analysis and system review of published studies. MATERIALS AND METHODS: The PubMed, EMBASE and Cochrane Library were searched, respectively, to identify all studies that addressed the issues of CTCs prior to initial treatment and progression-free survival (PFS) and overall survival (OS). Finally, ten citations were included for analysis and assessment of publication bias by using review manager 5.3 statistical software and STATA 15.0. RESULTS: Randomized model analyzing multivariate Cox Proportional Hazards Regression indicated that higher abundance of CTCs significantly predicts poorer prognosis of lung cancer cases basing both on PFS (Z = 2.31, P = 0.02) and OS of advanced cases (Z = 2.44, P = 0.01), and systematic study aslo indicated the similar results. CONCLUSION: High CTCs prior to initial treatment can predict shorter PFS and OS in NSCLC, and further studies are warranted in the future.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31706575

RESUMO

Lpg0189 is a type II secretion system-dependent extracellular protein with unknown function from Legionella pneumophila. Herein, we determined the crystal structure of Lpg0189 at 1.98 Šresolution by using single-wavelength anomalous diffraction (SAD). Lpg0189 folds into a novel chair-shaped architecture, with two sheets roughly perpendicular to each other. Bioinformatics analysis suggests Lpg0189 and its homologues are unique to Legionellales and evolved divergently. The interlinking structural and bioinformatics studies provide a better understanding of this hypothetical protein.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31727364

RESUMO

Laccases (benzenediol: oxygen oxidoreductases, EC1.10.3.2) can oxidize various substrates, and those which are tolerant to and even activated by salts have attracted a lot of attention due to their application potential in certain industries. The mechanism of the salt activation of laccases is awaiting to be elucidated yet. Our previous study (Li, Xie et al. 2018) supposed that the salt activation of marine laccase Lac15 might be attributed to Cl- ion specifically binding to some local sites to interfere substrate binding and/or electron transfer. In this study, we found two sites whose mutations resulted in elimination of the salt activation of Lac15's activity towards catechol and dopamine respectively, and revealed that the mutations affected the activity by altering both Em and kcat, demonstrating the supposed mechanism. A model for the salt activation of laccases was accordingly proposed, albeit some details are to be elucidated.

4.
Se Pu ; 37(11): 1157-1161, 2019 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642267

RESUMO

A method using ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of nine B vitamins in peptone. The samples were extracted with water. The analytes were separated on a Syncronis C18 column (100 mm×2.1 mm, 1.7 µm). The nine B vitamins were detected by ESI-MS/MS under the multiple reaction monitoring (MRM) mode, and the analysis was completed in 8 min. Quantification analysis was performed by using the external standard method. The correlation coefficients (R2) of the nine B vitamins in their linear ranges were greater than 0.999. The limits of detection were 0.09-1.67 µg/L. The relative standard deviations of the method were less than 3% (n=6). The mean recoveries of the nine B vitamins were 80.2%-103.9% at different spiked levels. The method is simple, accurate and sensitive, and is suitable for the determination of the nine B vitamins in peptone.


Assuntos
Peptonas/química , Complexo Vitamínico B/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem
5.
Cell Biol Int ; 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31498515

RESUMO

Acute lung injury (ALI) caused by sepsis occurs early and the condition is severe, and is also an important reason for accelerating the death of patients. Increasing evidence has identified long non-coding RNA (lncRNA) metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) as a regulator of ALI. However, the potential mechanism underlying MALAT1 on ALI still needs further identification. To explore the mechanisms of gene regulation expression mediated by MALAT1 through miR-149/MyD88 in lung injury inflammation, we constructed a lung injury inflammatory model using the lipopolysaccharides (LPS)-induced method and quantificated the cytokines and signaling cascade molecules as well as miR-149. The MALAT1, myeloid differentiation factor 88 (MyD88), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 levels were significantly increased, and the nuclear factor-κB (NF-κB) pathway was activated, but the miR-149 level was decreased in the LPS-induced ALI model. miR-149 directly targeted both lncRNA MALAT1 and the MyD88 gene. Knockdown of MALAT1 down-regulated the levels of MyD88, TNF-α, IL-1ß, and IL-6, and inhibited the NF-κB pathway. However, MALAT1 knockdown up-regulated the expression of miR-149. Overexpression of miR-149 down-regulated MyD88, TNF-α, IL-1ß, and IL-6 levels, and inhibited the NF-κB pathway. MALAT1 acts as a pro-inflammatory factor in ALI via the miR-149/MyD88/NF-κB axis and is therefore a potential novel therapeutic target for ALI treatment.

6.
Zhongguo Zhong Yao Za Zhi ; 44(12): 2637-2643, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359734

RESUMO

To investigate the effect of Fuyanshu Capsules combined with Western medicine antibiotics on symptoms and inflammatory factors IL-10 and IL-1ß in patients with pelvic inflammatory disease and its possible mechanism. Totally 112 patients with pelvic inflammatory disease of damp-heat stagnation treated since April 2017 to April 2018 were randomly divided into treatment group( group A,57 cases) and control group( group B,55 cases). The treatment group was given Fuyanshu Capsules for 56 d,and levofloxacin hydrochloride tablets and metronidazole tablets for 14 d. The control group was given Fuyanshu Capsules as its analogue. The curative rate,effective rate and inefficiency,serum IL-10 and IL-1ß levels were compared between the two groups. The curative effect was evaluated with McCormack score and traditional Chinese medicine( TCM) syndrome score. The recurrence rate and chronic pelvic pain were followed up after one menstrual cycle. It was found that the curative rate and effective rate of group A were higher than those of group B after treatment. After 28 d of treatment,there was a difference in the effective rate of TCM syndrome score between group A and group B( 62. 71% vs 8. 47%,P < 0. 01). After 56 d of treatment,serum IL-10 increased,while IL-1ß decreased in group A,which was significantly different from that in group B( P<0. 01). The recurrence rate of PID and chronic pelvic pain in group A were significantly lower than those in group B( P<0. 01). The results showed that Fuyanshu Capsules combined with levofloxacin and metronidazole could alleviate the clinical symptoms and signs of chronic pelvic inflammation of damp-heat stagnation type,reduce the recurrence rate of pelvic inflammation,relieve pelvic pain,and alleviate the inflammation status of patients by regulating the expression of IL-10 and IL-1ß in peripheral serum.


Assuntos
Antibacterianos/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Doença Inflamatória Pélvica/tratamento farmacológico , Cápsulas , Feminino , Humanos , Interleucina-10/sangue , Interleucina-1beta/sangue , Levofloxacino , Medicina Tradicional Chinesa , Metronidazol
7.
Dalton Trans ; 48(29): 10824-10833, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31204751

RESUMO

Rare earth-doped Ba3La(VO4)3 phosphors with tunable emitting colors were firstly explored and their photoluminescence properties were systematically investigated. The experimental results show that the Ba3La(VO4)3 phosphors exhibit high-brightness self-activated emission and enable us to sensitize the luminescence of rare earth activators. Under near-ultraviolet (UV) excitation, both the broadband emission from VO43- groups and the sharp peak emissions from Eu3+ ions are observed in Ba3La(VO4)3:Eu3+ phosphors. Modulation of the emitting color from green to red can be realized by adjusting the Eu3+ doping concentration, which is assigned to an efficient energy transfer from VO43- to Eu3+ ions. Notably, the optical thermometry of Ba3La(VO4)3:Eu3+ was characterized based on the fluorescence intensity ratio of VO43- and Eu3+ emissions in the 298-573 K range, with the maximum absolute and relative sensitivities of 0.0515 K-1 and 1.77% K-1 at 298 K. In addition, similar phenomena were observed in Sm3+ and Dy3+-doped Ba3La(VO4)3 phosphors. These results verify a feasible strategy for varying the emission color and realizing optical thermometry in the single-component phosphors by adjusting the energy transfer between the host and the activator. It provides new possibilities for the design of multifunctional materials for white light-emitting diodes and non-contact thermometry.

8.
Inorg Chem ; 58(12): 8245-8252, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31145602

RESUMO

The optical thermometry properties of LuVO4:Yb3+/Er3+@SiO2 nanoparticles (NPs) are studied in detail. In order to avoid the overheating effect for biological tissue caused by 980 nm radiation, 915 nm is employed as the excitation wavelength to investigate the upconversion (UC) and optical thermometry properties of the as-prepared NPs. In the visible region, the fluorescence intensity ratio (FIR) of the 2H11/2 and 4S3/2 levels of Er3+ is utilized to measure the temperature. The relative sensitivity SR in this case can be written as 1077/ T2, which is higher than that of ß-NaYF4:Yb3+/Er3+ NPs, ß-NaLuF4:Yb3+/Er3+ NPs, YVO4:Yb3+/Er3+ NPs, etc. In the near-infrared (NIR) region, an anomalous enhancement of the 4I13/2 → 4I15/2 transition with increasing temperature is observed. What is more, the FIR of peak 2 (located at 1496 nm) to peak 1 (located at 1527 nm) is changed regularly with increasing temperature, which can also be used to measure the temperature. The combination of the visible and NIR regions for optical thermometry can provide a self-referenced temperature determination to make measurement of the temperature more precise. In addition, the UC mechanism is also investigated, especially the population route of the 4F9/2 level of Er3+. Through analysis of the decay curves, we propose that the dominant way for populating the Er3+ 4F9/2 level is energy transfer from the Yb3+ 2F5/2 level to the Er3+ 4I13/2 level. All of the results reveal the potential application of LuVO4:Yb3+/Er3+@SiO2 NPs for dual-mode optical thermometry.

9.
World J Clin Cases ; 7(6): 691-704, 2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30968034

RESUMO

As an irreversible and perennial process, aging is accompanied by functional and morphological declines in organs. Generally, aging liver exhibits a decline in volume and hepatic blood flow. Even with a preeminent regenerative capacity to restore its functions after liver cell loss, its biosynthesis and metabolism abilities decline, and these are difficult to restore to previous standards. Apoptosis is a programmed death process via intrinsic and extrinsic pathways, in which Bcl-2 family proteins and apoptosis-related genes, such as p21 and p53, are involved. Apoptosis inflicts both favorable and adverse influences on liver aging. Apoptosis eliminates transformed abnormal cells but promotes age-related liver diseases, such as nonalcoholic fatty liver disease, liver fibrosis, cirrhosis, and liver cancer. We summarize the roles of apoptosis in liver aging and age-related liver diseases.

10.
Inorg Chem ; 58(6): 3780-3788, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30810033

RESUMO

A series of lanthanide organic complexes, namely, [Ln2PDC3(H2O)3]H2O (Ln = Eu, Tb, Eu xTb2- x, H2PDC: pyridine-3,5-dicarboxylic acid), were synthesized via hydrothermal method. Eu-PDC was characterized by single-crystal X-ray diffraction. The powder X-ray diffraction, Fourier transform infrared spectra, and thermogravimetric analysis illustrate that Eu-PDC, Tb-PDC, and Eu xTb2- x-PDC complexes are isostructural. All the complexes exhibit strong emission even though water molecules coordinated in the structure. Tunable emission color from green, yellow to red is realized by adjusting the Eu/Tb ratio in mixed Eu xTb2- x-PDC complexes. Energy transfer from Tb3+ to Eu3+ is discussed in detail via fluorescence decay and time resolution spectra. The detailed energy transfer process sees that the emitting color of Eu0.15Tb1.85-PDC shifts from green to orange in a time interval of 153-790 µs. In addition, temperature-dependent emission of the Eu0.05Tb1.95-PDC complex indicates that it is a potential solid state material for a luminescence thermometer in the range of 293-333 K. The temperature resolution is less than 0.16 K. The optical properties of the EuTb-PDC complex indicate that it is a multifunctional luminescent material with promising applications in temperature sensing, time resolution imaging, lighting, and displaying.

11.
Neurosci Biobehav Rev ; 98: 177-184, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30648559

RESUMO

With aging, various factors deteriorate the normal sleep process that is essential for the restoration of functional and physical performance. Due to aging-related diseases, life changes, or aging itself, disturbances in normal sleep cycles can profoundly affect healthy aging. To understand the interconnections between aging and the factors influencing sleep, with emerging evidence accumulated in recent years, this study elaborates on the roles of aging in sleep from four perspectives: cortical thinning, white matter degeneration, neurotransmitter dysregulation, and circadian disorganization. In brief, with aging, cortical thinning can be induced by the deposition of neurotoxic substances, and white matter degeneration can be induced by vascular abnormalities. These alterations emerging in the brain jointly disrupt sleep spindles and slow waves, leading to sleep disturbances. Age-related dysregulation in neurotransmitters (including galanin, orexin, serotonin, and adenosine) directly impairs the sleep modulation system. Disorganization in the circadian system consisting of suprachiasmatic nucleus dysfunction, reduced light transmission, and local circadian clock disruption collectively interrupts circadian rhythms, also causing sleep disturbances in the older. Of note is the bidirectional relationship between aging and sleep, which required us to examine this issue from different perspectives.


Assuntos
Envelhecimento/fisiologia , Ritmo Circadiano/fisiologia , Sono/fisiologia , Núcleo Supraquiasmático/fisiologia , Animais , Encéfalo/fisiologia , Relógios Circadianos/fisiologia , Humanos
12.
Proc Natl Acad Sci U S A ; 115(44): 11209-11214, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30327342

RESUMO

Old-age mortality decline has driven recent increases in lifespans, but there is no agreement about trends in the age pattern of old-age deaths. Some argue that old-age deaths should become compressed at advanced ages, others argue that old-age deaths should become more dispersed with age, and yet others argue that old-age deaths are consistent with little change in dispersion. However, direct analysis of old-age deaths presents unusual challenges: Death rates at the oldest ages are always noisy, published life tables must assume an asymptotic age pattern of deaths, and the definition of "old-age" changes as lives lengthen. Here we use robust percentile-based methods to overcome some of these challenges and show, for five decades in 20 developed countries, that old-age survival follows an advancing front, like a traveling wave. The front lies between the 25th and 90th percentiles of old-age deaths, advancing with nearly constant long-term shape but annual fluctuations in speed. The existence of this front leads to several predictions that we verify, e.g., that advances in life expectancy at age 65 y are highly correlated with the advance of the 25th percentile, but not with distances between higher percentiles. Our unexpected result has implications for biological hypotheses about human aging and for future mortality change.


Assuntos
Expectativa de Vida/tendências , Mortalidade/tendências , Idoso , Causas de Morte , Morte , Feminino , Previsões , Saúde Global/estatística & dados numéricos , Humanos , Tábuas de Vida , Masculino
13.
Br J Cancer ; 118(10): 1337-1348, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29717200

RESUMO

BACKGROUND: Chemerin, a known chemoattractant, participates in multiple biological events. However, its role in cancer remains largely unknown. METHODS: Chemerin expression was evaluated by real-time PCR, western blot and immunohistochemistry. Forced expression, RNAi, immunoprecipitation, etc. were used in function and mechanism study. Mouse models of extrahepatic and intrahepatic metastasis were employed to evaluate the therapeutic potential of chemerin. RESULTS: Chemerin expression was significantly downregulated in hepatocellular carcinoma, and associated with poor prognosis of HCC patients. Forced expression of chemerin inhibited in vitro migration, invasion and in vivo metastasis of HCC cells. Administration of chemerin effectively suppressed extrahepatic and intrahepatic metastases of HCC cells, resulting in prolonged survival of tumour-bearing nude mice. Chemerin upregulated expression and phosphatase activity of PTEN by interfering with PTEN-CMKLR1 interaction, leading to weakened ubiquitination of PTEN and decreased p-Akt (Ser473) level, which was responsible for suppressed migration, invasion and metastasis of HCC cells. Positive correlation between chemerin and PTEN, and reverse correlation between chemerin and p-Akt (Ser473) were also observed in HCC clinical samples and intrahepatic mouse model in vivo. CONCLUSIONS: Our study has revealed the suppressive role and therapeutic potential of chemerin in HCC metastasis, providing both a prognostic marker and drug candidate for HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Quimiocinas/administração & dosagem , Peptídeos e Proteínas de Sinalização Intercelular/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , PTEN Fosfo-Hidrolase/genética , Receptores de Quimiocinas/genética , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Movimento Celular , Proliferação de Células , Quimiocinas/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica , Proteína Oncogênica v-akt/genética , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Sensors (Basel) ; 18(3)2018 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-29518959

RESUMO

The GaoFen-3 (GF-3) satellite, launched on 10 August 2016, is the first C-band polarimetric synthetic aperture radar (PolSAR) satellite in China. The PolSAR system of GF-3 can collect a significant wealth of information for geophysical research and applications. Being used for related applications, GF-3 PolSAR images must be of good quality. It is necessary to evaluate the quality of polarimetric data and achieve the normalized quality monitoring during 8-year designed life of GF-3. In this study, a new quality assessment method of PolSAR data based on common distributed targets is proposed, and the performance of the method is analyzed by simulations and GF-3 experiments. We evaluate the quality of GF-3 PolSAR data by this method. Results suggest that GF-3 antenna is highly isolated, and the quality of calibrated data satisfies the requests of quantitative applications.

15.
Artigo em Inglês | MEDLINE | ID: mdl-28915467

RESUMO

Luminescence of defects and/or impurities is important for phosphors. One broad emission band centered at 785nm was observed in (Y0.97Ce0.03)3(Al1-xCrx)5O12 (x=0.005, 0.01, 0.03, 0.06, 0.09), (YAG:Ce,Cr) nano-particles synthesized by polymer-assisted sol-gel method in this work. In order to study the source of this wide emission band, the crystalline phase structure of the phosphors was examined by X-ray diffraction (XRD). No obvious diffraction peaks due to impurity phase were observed even though the calcining temperature of the samples arrived at 1400°C. The anti-site defects were excluded. No detectable signals of impurities were obtained by X-ray Photoelectron Spectroscopy (XPS) or inductively coupled plasma mass spectrometry (ICP-MS). Based on the photo-luminescence results of YAG:Ce,Cr, YAG:Ce and YAG:Fe phosphors, the wide emission band is attributed to the 4T1(4G)→6A1(6S) transition from the trace impurity of Fe3+. The excitation band at 280nm is assigned to Fe3+-O2- charge transfer band.

16.
Oncotarget ; 8(60): 102640-102652, 2017 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-29254277

RESUMO

Various changes in the liver during aging can reduce hepatic function and promote liver injury. Aging is associated with high morbidity and a poor prognosis in patients with various liver diseases, including nonalcoholic fatty liver disease, hepatitis C and liver cancer, as well as with surgeries such as partial hepatectomy and liver transplantation. In addition, apoptosis increases with liver aging. Because apoptosis is involved in regeneration, fibrosis and cancer prevention during liver aging, and restoration of the appropriate level of apoptosis can alleviate the adverse effects of liver aging, it is important to understand the mechanisms underlying this process. Herein, we elaborate on the causes of apoptosis during liver aging, with a focus on oxidative stress, genomic instability, lipotoxicity, endoplasmic reticulum stress, dysregulation of nutrient sensing, and liver stem/progenitor cell activity.

17.
Inorg Chem ; 56(22): 13955-13961, 2017 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-29095599

RESUMO

The red upconversion (UC) emission of Eu3+ ions in Lu2O3: Yb3+/Eu3+ powders was successfully enhanced by tridoping Ho3+ ions in the matrix, which is due to the bridging function of Ho3+ ions. The experiment data manifest that, in Yb3+/Eu3+/Ho3+ tridoped system, the Ho3+ ions are first populated to the green emitting level 5F4/5S2 through the energy transfer (ET) processes from the excited Yb3+ ions. Subsequently, the Ho3+ ions at 5F4/5S2 level can transfer their energy to the Eu3+ ions at the ground state, resulting in the population of Eu3+5D0 level. With the assistance of the bridging function of Ho3+ ion, this ET process is more efficient than the cooperative sensitization process between Yb3+ ion and Eu3+ ion. Compared with Lu2O3: 5 mol % Yb3+/1 mol % Eu3+, the UC intensity of Eu3+5D0→7F2 transition in Lu2O3: 5 mol % Yb3+/1 mol % Eu3+/0.5 mol % Ho3+ is increased by a factor of 8.

18.
Inorg Chem ; 56(15): 9194-9199, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28699751

RESUMO

The monochromaticity improvement of green upconversion (UC) in Lu2O3:Yb3+/Ho3+ powders has been successfully realized by tridoping Eu3+. The integral area ratio of green emission to red emission of Ho3+ increases 4.3 times with increasing Eu3+ doping concentration from 0 to 20 mol %. The energy transfer (ET) mechanism in the Yb3+/Ho3+/Eu3+ tridoping system has been investigated carefully by visible and near-infrared (NIR) emission spectra along with the decay curves, revealing the existence of ET from the Ho3+5F4/5S2 level tothe Eu3+5D0 level and ET from the Ho3+5I6 level to the Eu3+7F6 level. In addition, the population routes of the red-emitting Ho3+5F5 level in the Yb3+/Ho3+ codoped system under 980 nm wavelength excitation have also been explored. The ET process from the Yb3+2F5/2 level to the Ho3+5I7 level and the cross-relaxation process between two nearby Ho3+ ions in the 5F4/5S2 level and 5I7 level, respectively, have been demonstrated to be the dominant approaches for populating the Ho3+5F5 level. The multiphonon relaxation process originating from the Ho3+5F4/5S2 level is useless to populate the Ho3+5F5 level. As the energy level gap between the Ho3+5I7 level and Ho3+5I8 level matches well with that between Eu3+7F6 level and Eu3+7F0 level, the energy of the Ho3+5I7 level can be easily transferred to the Eu3+7F6 level by an approximate resonant ET process, resulting in a serious decrease in the red UC emission intensity. Since this ET process is more efficient than the ET from the Ho3+5F4/5S2 level to the Eu3+5D0 level as well as the ET from the Ho3+5I6 level to the Eu3+7F6 level, the integral area ratio of green emission to red emission of Ho3+ has been improved significantly.

19.
Inorg Chem ; 56(3): 1498-1503, 2017 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-28098986

RESUMO

A high-temperature solid-state method was used to synthesize the Ho3+- and Yb3+-codoped cubic Lu2O3 powders. The crystal structures of the as-prepared powders were characterized by X-ray diffraction. The energy-transfer (ET) phenomenon between Ho3+ ions and Yb3+ ions was verified by the steady-state spectra including visible and near-infrared (NIR) regions. Beyond that, the decay curves were also measured to certify the existence of the ET process. The downconversion phenomena appeared when the samples were excited by 446 nm wavelength corresponding to the transition of Ho3+: 5I8→5G6/5F1. On the basis of the analysis of the relationship between the initial transfer rate of Ho3+: 5F3 level and the Yb3+ doping concentration, it indicates that the ET from 5F3 state of Ho3+ ions to 2F5/2 state of Yb3+ ions is mainly through a two-step ET process, not the long-accepted cooperative ET process. In addition, a 62% ET efficiency can be achieved in Lu2O3: 1% Ho3+/30% Yb3+. Unlike the common situations in which the NIR photons are all emitted by the acceptors Yb3+, the sensitizers Ho3+ also make contributions to the NIR emission upon 446 nm wavelength excitation. Meanwhile, the 5I5→5I8 transition and 5F4/5S2→5I6 transition of Ho3+ as well as the 2F5/2→2F7/2 transition of Yb3+ match well with the optimal spectral response of crystalline silicon solar cells. The current research indicates that Lu2O3: Ho3+/Yb3+ is a promising material to improve conversion efficiency of crystalline silicon solar cell.

20.
Chin Med J (Engl) ; 129(9): 1072-7, 2016 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-27098793

RESUMO

BACKGROUND: Gaucher's disease (GD) is an autosomal recessive disorder caused by a deficiency of acid ß-glucosidase (glucocerebrosidase [GBA]) that results in the accumulation of glucocerebroside within macrophages. Many mutations have been reported to be associated with this disorder. This study aimed to discover more mutations and provide data for the genetic pattern of the gene, which will help the development of quick and accurate genetic diagnostic tools for this disease. METHODS: Genomic DNA was obtained from peripheral blood leukocytes of the patient and Sanger sequencing is used to sequence GBA gene. Sequence alignments of mammalian ß-GBA (GCase) and three-dimensional protein structure prediction of the mutation were made. A construct of this mutant and its compound heterozygous counterpart were used to measure GCase in vitro. RESULTS: GCase is relatively conserved at p.T219A. This novel mutation differs from its wild-type in structure. Moreover, it also causes a reduction in GCase enzyme activity. CONCLUSION: This novel mutation (c.655A>G, p.T219A) is a pathogenic missense mutation, which contributes to GD.


Assuntos
Doença de Gaucher/genética , Glucosilceramidase/genética , Mutação de Sentido Incorreto , Pré-Escolar , Glucosilceramidase/química , Humanos , Masculino , Modelos Moleculares , Estrutura Terciária de Proteína , Análise de Sequência de DNA
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