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1.
J Biol Chem ; 295(16): 5461-5469, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32184352

RESUMO

Telomeres are specific nucleoprotein structures that are located at the ends of linear eukaryotic chromosomes and play crucial roles in genomic stability. Telomere DNA consists of simple repeats of a short G-rich sequence: TTAGGG in mammals and TTTAGGG in most plants. In recent years, the mammalian telomeric G-rich repeats have been shown to form G-quadruplex (G4) structures, which are crucial for modulating telomere functions. Surprisingly, even though plant telomeres are essential for plant growth, development, and environmental adaptions, only few reports exist on plant telomeric G4 DNA (pTG4). Here, using bulk and single-molecule assays, including CD spectroscopy, and single-molecule FRET approaches, we comprehensively characterized the structure and dynamics of a typical plant telomeric sequence, d[GGG(TTTAGGG)3]. We found that this sequence can fold into mixed G4s in potassium, including parallel and antiparallel structures. We also directly detected intermediate dynamic transitions, including G-hairpin, parallel G-triplex, and antiparallel G-triplex structures. Moreover, we observed that pTG4 is unfolded by the AtRecQ2 helicase but not by AtRecQ3. The results of our work shed light on our understanding about the existence, topological structures, stability, intermediates, unwinding, and functions of pTG4.

2.
Biochem Biophys Res Commun ; 524(4): 1057-1063, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32067740

RESUMO

Adherens junction-associated protein-1 (AJAP1), also called SHREW1, was first discovered as a novel component of adherens junctions in 2004. In later studies, AJAP1 was found to suppress invasion and predict recurrence of some tumors. Apart from its function as a putative tumor suppressor, AJAP1 is still poorly understood. Schwenk et al. recently found that AJAP1 was tightly associated with the γ-Aminobutyric acid type B receptor subunit 1(GABABR1). It is well known that GABABR plays a vital role in epilepsy as an inhibitory transmitter receptor. Structurally adjacent, possibly functionally interacting, therefore, we hypothesize that AJAP1 participates in the onset and progression of epilepsy. We designed this experiment to investigate the expression and location of AJAP1 in temporal lobe epilepsy (TLE) patients and kainic acid(KA)-induced epilepsy animal models by immunofluorescence and Western blot analyses. We overexpressed and inhibited AJAP1 through lentiviruses in KA-induced models and observed the corresponding effects on epileptic animals. Double-label immunofluorescence showed that AJAP1 was expressed mainly in neurons. Western blot analysis revealed that AJAP1 expression was downregulated in the neocortex of TLE patients and the hippocampus and neocortex of epileptic animal models. The overexpression of AJAP1 can reduce the frequency of spontaneous seizures, whereas the inhibition of AJAP1 expression can increase the incidence rate. Our study demonstrated that AJAP1 may be involved in the pathogenic process of epilepsy and may represent a novel antiepileptic target.

3.
Food Chem ; 317: 126422, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32088402

RESUMO

Myosin light chain isoform 1 (MLC1) is reported to be a novel allergen in crayfish (Procambarus clarkii). However, little information is available about its allergic epitopes. In this study, recombinant crayfish MLC1 (rMLC1) was expressed and confirmed by mass spectrometry. Circular dichroic analysis and serological test were performed for the measuring of structural and immunological properties of rMLC1. Specific-protein-A-enriched IgG raised in rabbits against purified rMLC1 was used to screen a phage display random peptide library. Nine MLC1 mimotope clones were identified among 16 random clones after biopanning. Five conformational epitopes were identified with the program LocaPep, and mapped into 3 epitope regions at the antibody-binding interface of MLC1. MLC1 of crayfish showed high primary and secondary structure identity to MLC of other allergenic species, its epitopes were located in the structure conserved regions, and its cross-reactivity among related species was indicated by immunological assays.

4.
Neuroimage ; 206: 116226, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31593792

RESUMO

Accurate prediction of individuals' brain age is critical to establish a baseline for normal brain development. This study proposes to model brain development with a novel non-negative projective dictionary learning (NPDL) approach, which learns a discriminative representation of multi-modal neuroimaging data for predicting brain age. Our approach encodes the variability of subjects in different age groups using separate dictionaries, projecting features into a low-dimensional manifold such that information is preserved only for the corresponding age group. The proposed framework improves upon previous discriminative dictionary learning methods by incorporating orthogonality and non-negativity constraints, which remove representation redundancy and perform implicit feature selection. We study brain development on multi-modal brain imaging data from the PING dataset (N = 841, age = 3-21 years). The proposed analysis uses our NDPL framework to predict the age of subjects based on cortical measures from T1-weighted MRI and connectome from diffusion weighted imaging (DWI). We also investigate the association between age prediction and cognition, and study the influence of gender on prediction accuracy. Experimental results demonstrate the usefulness of NDPL for modeling brain development.

5.
Sci Total Environ ; 694: 133547, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756821

RESUMO

A slope failure of roughly 26,000 m3 occurred on September 7th, 2017 in the upper layer of a north-facing slope at Autumn Pasture in Zhimei Village, Chenduo County, Tibetan Autonomous Prefecture of Yushu (34°07'02.26″N, 96°37'10.90″E). Field investigations have indicated there is no continuous or discontinuous permafrost found in this area. The earth slope is susceptible to seasonal frost in freezing season and heavy rainfall in raining season. Hence, we hypothesized that the slope failure was induced by increasing pore water pressure at the basal surface, which resulted from the combined effect of a frozen upper layer and accumulated infiltrated soil water. With the accessible meteorological data from National Oceanic and Atmospheric Administration (NOAA), numerical software (CoupModel) was used to simulate the hydro-thermal state of the source area in order to explore the influence of atmospheric change and the triggering mechanism of slope failure. The simulation results indicate that an unexpected cold snap promoted the freezing process of the shallow soil layer, and the drainage of liquid water was impeded by this frozen layer. Accumulated downslope water at source area, namely the slope toe, led to the increasing of pore water pressure in the deeper parts of the soil. The source area is located in the catchment area, where water accumulated from surrounding slopes. Increased gravity of the upper layer resulting from downslope infiltrating soil water, and decreased shear strength of basal surface both contributed to the slope instability. The failure illustrated the influence of seasonal frost and sustained precipitation on mass wasting in Qinghai-Tibet Plateau (QTP).

6.
Adv Sci (Weinh) ; 6(18): 1901084, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31572648

RESUMO

Since the first intercalation of layered silicates by using supercritical CO2 as a processing medium, considerable efforts have been dedicated to intercalating and exfoliating layered two-dimensional (2D) materials in various supercritical fluids (SCFs) to yield single- and few-layer nanosheets. Here, recent work in this area is highlighted. Motivating factors for enhancing exfoliation efficiency and product quality in SCFs, mechanisms for exfoliation and dispersion in SCFs, as well as general metrics applied to assess quality and processability of exfoliated 2D materials are critically discussed. Further, advances in formation and application of 2D material-based composites with assistance from SCFs are presented. These discussions address chemical transformations accompanying SCF processing such as doping, covalent surface modification, and heterostructure formation. Promising features, challenges, and routes to expanding SCF processing techniques are described.

7.
J Environ Radioact ; 208-209: 106008, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31419761

RESUMO

Channelization significantly affects soil erosion in river floodplains. The object of this study was to use 137Cs as a tracer to determine the 137Cs inventory and derived soil erosion rates under various land use types in a catchment on channelized river floodplain in the lower reaches of Yangtze River, China. Sampling was carried out to establish a137Cs reference inventory in a 70-year old paddy field located on the shoulder-slope of a local hill. The mean reference inventory of 137Cs was 1275 Bq m-2, whereas the 137Cs inventory within the catchment ranged from 284 to 1150 Bq m-2 and the soil erosion rates from -33.3 to -2.4 t ha-1 yr-1, respectively. The dominated land use of paddy in cultivated soils contributed relative low soil erosion. Bamboo and castanea mollissima were preferential for local land uses in uncultivated soils in comparison with woodland and Pinnus massoniana. The rates of soil erosion rates in old tea garden were higher than that in new tea garden. Overall, severe soil erosion and no deposition in the entire catchment occurred in the entire catchment due to the human-induced channelization in the 1970s. Our results suggest that restricting farmland being returned to tea plantations, thereby maintaining the current land use types would reduce soil erosion in river floodplain in the future.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo/análise , Radioisótopos de Césio/análise , China , Fenômenos Geológicos , Rios/química
8.
Biochemistry ; 58(38): 3955-3959, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31468963

RESUMO

Guanine (G) quadruplexes (G4s) can be formed by G-rich sequences when stabilized by the binding of cations (typically K+ or Na+) and play an essential role in replication, recombination, transcription, and telomere maintenance. Understanding of the G4 folding process is crucial for determining their cellular functions. However, G4-K+ interactions and folding pathways are still not well understood. By using human telomeric G4 (hTG4) as an example, two binding states corresponding to two K+ cations binding to hTG4 were distinguished clearly and fitted precisely. The basic binding parameters during G4-K+ interactions were measured and calculated by taking advantage of microscale thermophoresis (MST), which monitors the changes in charge and size at the same time. The G-hairpin and G-triplex have been suggested as intermediates during G4 folding and unfolding. We further analyzed the equilibrium dissociation constants of 10 possible folding intermediates using MST; thus, the energetically favorable folding/unfolding pathways were proposed. The results might not only shed new light on G4-K+ interactions and G4 folding pathways but also provide an example for experimentally studying DNA-ion interactions.

9.
Ecol Evol ; 9(9): 5219-5235, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31110674

RESUMO

Northwestern China has a wealth of endemic species, which has been hypothesized to be affected by the complex paleoclimatic and paleogeographic history during Quaternary. In this paper, we used Gymnocarpos przewalskii as a model to address the evolutionary history and current population genetic structure of species in northwestern China. We employed two chloroplast DNA fragments (rps16 and psbB-psbI), one nuclear DNA fragment (ITS), and simple sequence repeat (SSRs) to investigate the spatial genetic pattern of G. przewalskii. High genetic diversity (cpDNA: h S = 0.330, h T = 0.866; ITS: h S = 0.458, h T = 0.872) was identified in almost all populations, and most of the population have private haplotypes. Moreover, multimodal mismatch distributions were observed and estimates of Tajima's D and Fu's FS tests did not identify significantly departures from neutrality, indicating that recent expansion of G. przewalskii was rejected. Thus, we inferred that G. przewalskii survived generally in northwestern China during the Pleistocene. All data together support the genotypes of G. przewalskii into three groups, consistent with their respective geographical distributions in the western regions-Tarim Basin, the central regions-Hami Basin and Hexi Corridor, and the eastern regions-Alxa Desert and Wulate Prairie. Divergence among most lineages of G. przewalskii occurred in the Pleistocene, and the range of potential distributions is associated with glacial cycles. We concluded that climate oscillation during Pleistocene significantly affected the distribution of the species.

10.
J Agric Food Chem ; 67(17): 4958-4966, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30966750

RESUMO

The mud crab ( Scylla paramamosain) is widely consumed but can cause a severe food allergic reaction. To reduce allergenicity to arginine kinase (AK), site-directed mutagenesis was used to destroy disulfide bonds or mutate critical amino acids of conformational epitopes. Three hypoallergenic mutant AKs (mAK1, mAK2, and mAK3) were generated, with the immunoreactivity decreasing by 54.2, 40.1, and 71.4%, respectively. In comparison to recombinant AK (rAK), the structure of mAKs was clearly changed. Additionally, antisense peptides were designed on the basis of linear epitopes and pepsin-cutting sites of AK. Five peptide aptamers were screened by molecular docking and then analyzed by the immunoglobulin E inhibition enzyme-linked immunosorbent assay and human Laboratory of Allergic Diseases 2 mast cell degranulation assay. The peptide aptamers could significantly inhibit allergenicity of rAK and mAKs, and the inhibitory effect of peptide aptamer 3 was slightly better than the others. These results provide synergistic methods to reduce allergenicity to AK, which could be applied to other shellfish allergens.


Assuntos
Aptâmeros de Peptídeos/genética , Arginina Quinase/genética , Arginina Quinase/imunologia , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Braquiúros/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Adolescente , Adulto , Alérgenos/química , Alérgenos/genética , Alérgenos/imunologia , Sequência de Aminoácidos , Animais , Aptâmeros de Peptídeos/imunologia , Arginina Quinase/química , Proteínas de Artrópodes/química , Braquiúros/enzimologia , Braquiúros/genética , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Feminino , Humanos , Imunoglobulina E/imunologia , Masculino , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Adulto Jovem
11.
Mikrochim Acta ; 186(4): 264, 2019 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-30929090

RESUMO

The presented voltammetric mercury(II) sensor is based on the specific interaction between Hg(II) ion and thymine-thymine base pairs. Reduced graphene oxide is functionalized with gold nanorods and then loaded with thionine and streptavidin (RGO@AuNR-TH-SA). A T-rich thiolated DNA (S1) is firstly immobilized on a gold electrode. In the presence of Hg (II), the T-rich biotin-DNA (biotin-S2) binds to S1 via T-Hg(II)-T interaction. Then, the RGO@AuNR-TH-SA is linked to the gold electrode by specific binding between SA and biotin-S2. This produces an electrochemical signal (at -0.208 V vs. Ag/AgCl) of TH that depends on the concentration of Hg (II). The peak current increases linearly in the 1 to 200 nM Hg (II) concentration range, and the detection limit is 0.24 nM. The sensor is highly selective for Hg (II) over other environmentally relevant metal ions, even at concentration ratios of >1000. Graphical abstract Schematic representation of a voltammetric biosensor for mercury(II) using reduced graphene oxide@gold nanorods (RGO@AuNRs) and thymine-Hg(II)-thymine interaction. It is based on the fact that RGO@AuNR can strongly adsorb thionine (TH) and streptavidin to realize the signal amplification.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Grafite/química , Mercúrio/análise , Nanotubos/química , Timina/química , Pareamento de Bases , DNA/genética , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Ouro/química , Ácidos Nucleicos Imobilizados/química , Limite de Detecção , Fenotiazinas/química , Reprodutibilidade dos Testes , Estreptavidina/química , Poluentes Químicos da Água/análise
12.
PLoS One ; 14(2): e0211696, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30730930

RESUMO

Tugarinovia (Family Asteraceae) is a monotypic genus. It's sole species, Tugarinovia mongolica Iljin, is distributed in the northern part of Inner Mongolia, with one additional variety, Tugarinovia mongolica var ovatifolia, which is distributed in the southern part of Inner Mongolia. The species has a limited geographical range and declining populations. To understand the phylogeographic structure of T. mongolica, we sequenced two chloroplast DNA regions (psbA-trnH and psbK-psbI) from 219 individuals of 16 populations, and investigated the genetic variation and phylogeographic patterns of T. mongolica. The results identified a total of 17 (H1-H17) chloroplast haplotypes. There were no haplotypes shared between the northern (T. mongolica) and southern groups (T. mongolica var. ovatifolia), and they formed two distinct lineages. The regional split was also supported by AMOVA and BEAST analyses. AMOVA showed the main variation that occurred between the two geographic groups. The time of divergence of the two groups can be dated to the early Pleistocene epoch, when climate fluctuations most likely resulted in the allopatric divergence of T. mongolica. The formation of the desert blocked genetic flow and enhanced the divergence of the northern and southern groups. Our results indicate that the genetic differences between T. mongolica and T. mongolica var. ovatifolia are consistent with previously proposed morphological differences. We speculate that the dry, cold climate and the expansion of the desert during the Quaternary resulted in the currently observed distribution of extant populations of T. mongolica. In the northern group, the populations Chuanjinsumu, Wuliji and Yingen displayed the highest genetic diversity and should be given priority protection. The southern group showed a higher genetic drift (FST = 1, GST = 1), and the inbreeding load (HS = 0) required protection for each population. Our results propose that the protection of T. mongolica should be implemented through in situ and ex situ conservation practices to increase the effective population size and genetic diversity.


Assuntos
Asteraceae/genética , China , Clima , DNA de Cloroplastos/genética , DNA de Plantas/genética , Fluxo Gênico/genética , Variação Genética/genética , Genética Populacional/métodos , Haplótipos/genética , Filogenia , Filogeografia/métodos , Análise de Sequência de DNA/métodos
13.
PeerJ ; 7: e6264, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30697480

RESUMO

Climatic fluctuations during the Quaternary significantly affect many species in their intraspecific divergence and population structure across northwest China. In order to investigate the impact of climate change on herbaceous plants, we studied Panzerina lanata (Lamiaceae), a widely distributed species. Sequences of two chloroplast DNA (cpDNA) intergenic spacers (trnH-psbA and rpoB-trnC) and a nuclear ribosomal region (nrDNA, ITS) were generated from 27 populations of Panzerina lanata and resulted in the identification of seven chloroplast haplotypes and thirty-two nuclear haplotypes. We applied AMOVA, neutrality test and mismatch distribution analysis to estimate genetic differentiation and demographic characteristics. The divergence times of the seven cpDNA haplotypes were estimated using BEAST. Our results revealed high levels of genetic diversity (cpDNA: Hcp = 0.6691, H T = 0.673; nrDNA: Hnr = 0.5668, H T = 0.577). High level of genetic differentiation (G ST = 0.950) among populations was observed in the cpDNA sequences, while the genetic differentiation values (G ST = 0.348) were low in nuclear sequences. AMOVA results revealed major genetic variation among the three groups: northern, central, and eastern group. However, the genetic differentiation in ITS data was not found. The species distribution modeling and demographic analysis indicated that P. lanata had not experienced recent range expansion. The occurrence of divergence between seven cpDNA haplotypes, probably during Pleistocene, coincides with aridification and expansion of the desert across northwest China that resulted in species diversification and habitat fragmentation. In addition, we discovered that the deserts and the Helan Mountains acted as effective geographic barriers that promoting the intraspecific diversity of P. lanata.

14.
Artigo em Inglês | MEDLINE | ID: mdl-30296228

RESUMO

In recent years, approaches based on nonlocal self similarity and global structure regularization have led to significant improvements in image restoration. Nonlocal self similarity exploits the repetitiveness of small image patches as a powerful prior in the reconstruction process. Likewise, global structure regularization is based on the principle that the structure of objects in the image is represented by a relatively small portion of pixels. Enforcing this structural information to be sparse can thus reduce the occurrence of reconstruction artifacts. So far, most image restoration approaches have considered one of these two strategies, but not both. This paper presents a novel image restoration method that combines nonlocal self similarity and global structure sparsity in a single efficient model. Group of similar patches are reconstructed simultaneously, via an adaptive regularization technique based on the weighted nuclear norm. Moreover, global structure is preserved using an innovative strategy, which decomposes the image into a smooth component and a sparse residual, the latter regularized using l1 norm. An optimization technique, based on the Alternating Direction Method of Multipliers (ADMM) algorithm, is used to recover corrupted images efficiently. The performance of the proposed method is evaluated on two important image restoration tasks: image completion and super-resolution. Experimental results show our method to outperform state-of-the-art approaches for these tasks, for various types and levels of image corruption.

15.
J Agric Food Chem ; 66(34): 9127-9137, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30107732

RESUMO

Mud crab ( Scylla serrata), which is widely consumed, can cause severe allergic symptoms. Eight linear epitopes and seven conformational epitopes of tropomyosin (TM) from S. serrata were identified using phage display. The conformational epitopes were formed based on the coiled-coil structure of TM. Most of the epitopes were located in the regions where primary structures were conserved among crustacean TM. Twelve synthetic peptides were designed according to the epitopes and trypsin-cutting sites of TM, among them, three synthetic peptides (including one linear epitope and two conformational epitopes) were recognized by all of the patient sera using inhibitory dot blotting. A triple-variant (R90A-E164A-Y267A) was constructed based on the critical amino acids of the TM epitope. The IgE-binding activity of the triple-variant was significantly reduced compared with that of native TM. The results of phage display and site-directed mutagenesis offered new information regarding conformational epitopes of TM.


Assuntos
Alérgenos/genética , Alérgenos/imunologia , Bacteriófagos/genética , Braquiúros/imunologia , Epitopos/imunologia , Tropomiosina/genética , Tropomiosina/imunologia , Alérgenos/química , Animais , Bacteriófagos/metabolismo , Braquiúros/genética , Mapeamento de Epitopos , Epitopos/química , Epitopos/genética , Hipersensibilidade Alimentar/imunologia , Humanos , Imunoglobulina E/imunologia , Mutagênese Sítio-Dirigida , Tropomiosina/química
16.
Sci Total Environ ; 616-617: 296-304, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29121578

RESUMO

Organic carbon (OC) buried in lake sediment is an important component of the global carbon cycle. The impact of eutrophication on OC burial in lakes should be addressed due to worldwide lake eutrophication. Fourteen 210Pb- and 137Cs-dated sediment cores taken in Dianchi Lake (China) in August 2006 (seven cores) and July 2014 (seven cores) were analyzed to evaluate the response of the organic carbon accumulation rate (OCAR) to eutrophication and algal blooms over the past hundred years. The mean value of OCAR before eutrophication occurred in 1979, 16.62±7.53 (mean value±standard deviation), increased to 54.33±27.29gm-2yr-1 after eutrophication. It further increased to 61.98±28.94gm-2yr-1 after algal blooms occurred (1989). The accumulation rate of organic nitrogen (ONAR) is coupled with OCAR. The high loss rate of OC and organic nitrogen (ON) leads to a long-term burial efficiency of only 10% and 5% of OC and ON. However, this efficiency can still lead to an increase in OCAR by a factor of 4.55 during algal blooms in Dianchi Lake. Dianchi Lake stored 1.26±0.32 Tg carbon and 0.071±0.018 Tg nitrogen, including 0.94±0.23 Tg OC and 0.32±0.14 Tg inorganic carbon, 0.066±0.018 Tg ON, 0.002±0.001 Tg nitrate nitrogen (NO3-N) and 0.003±0.001 Tg ammonium nitrogen (NH4-N) between 1900 and 2012.


Assuntos
Carbono/análise , Eutrofização , Sedimentos Geológicos/química , Lagos/química , Nitrogênio/análise , Fitoplâncton , Sepultamento , China , Monitoramento Ambiental , Fósforo
17.
PLoS One ; 12(9): e0178389, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28931016

RESUMO

The Tianshan Mountains play a significant role in the Central Asian flora and vegetation. Lagochilus has a distribution concentration in Tianshan Mountains and Central Asia. To investigate generic spatiotemporal evolution, we sampled most Lagochilus species and sequenced six cpDNA locations (rps16, psbA-trnH, matK, trnL-trnF, psbB-psbH, psbK-psbI). We employed BEAST Bayesian inference for dating, and S-DIVA, DEC, and BBM for ancestral area/biome reconstruction. Our results clearly show that the Tianshan Mountains, especially the western Ili-Kirghizia Tianshan, as well as Sunggar and Kaschgar, was the ancestral area. Ancestral biome was mainly in the montane steppe zone of valley and slope at altitudes of 1700-2700 m, and the montane desert zone of foothill and front-hill at 1000-1700 m. Here two sections Inermes and Lagochilus of the genus displayed "uphill" and "downhill" speciation process during middle and later Miocene. The origin and diversification of the genus were explained as coupled with the rapid uplift of the Tianshan Mountains starting in late Oligocene and early Miocene ca. 23.66~19.33 Ma, as well as with uplift of the Qinghai-Tibetan Plateau (QTP) and Central Asian aridification.


Assuntos
Ecossistema , Lamiaceae/genética , Teorema de Bayes , DNA de Plantas/química , DNA de Plantas/classificação , DNA de Plantas/isolamento & purificação , DNA de Plantas/metabolismo , Evolução Molecular , Variação Genética , Quirguistão , Filogenia , Análise de Sequência de DNA
18.
Sci Total Environ ; 603-604: 390-400, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28633116

RESUMO

Increased organic carbon and nitrogen accumulation rates (OCAR and ONAR) in lake sediment significantly regulate the global carbon cycle. However, the reasons for and contributors to the increased OCAR and ONAR are unclear. Seven sediment cores, collected in July 2014 from Dianchi Lake, China, were used to evaluate the effects of autochthonous and allochthonous sources on OCAR and ONAR. The results indicate that OCAR and ONAR increased by factors of 4.33 and 7.34 over the past hundred years (1900-2000), particularly after algal blooms began to occur frequently (beginning in the 1980s). Dianchi stored 0.467±0.0055Tg (mean value±standard deviation) organic carbon (OC) and 0.033±0.0004Tg organic nitrogen (ON) after 1986, which is almost equal to the total storage of OC and ON from 1900 to 1985 (OC, 0.468±0.0022Tg; ON, 0.032±0.0002Tg). OCAR and ONAR increases were due to increasing autochthonous production and allochthonous loading. Examination of the increased OCAR, which was estimated from a newly developed multi-source mixing model, suggests that >90% of increased OCAR was caused by allochthonous sources (such as intensified cultivation, land-use cover change, etc.) in southern and eastern Dianchi and that >70% of the increased OCAR was due to autochthonous sources in western and northern Dianchi Lake. The significant spatial and temporal variation in the contributors to increased OCAR indicates complicated migration and transformation of OC in inland lakes. Land use cover change around Dianchi and the occurrence of algal blooms regulate the contributions of allochthonous and autochthonous sources to the increased OC and ON.

19.
Chem Commun (Camb) ; 53(41): 5625-5628, 2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28480916

RESUMO

Three cationic conjugated polyelectrolytes (CPEs) with a common poly(p-phenylene ethynylene) backbone and different galactose-containing side chains were designed and synthesized. These CPEs were characterized and their application in targeted hepatoma cell imaging was demonstrated.


Assuntos
Alquinos/química , Carcinoma Hepatocelular/patologia , Éteres/química , Galactose/química , Neoplasias Hepáticas/patologia , Imagem Óptica , Alquinos/síntese química , Linhagem Celular Tumoral , Éteres/síntese química , Células HeLa , Células Hep G2 , Humanos , Estrutura Molecular , Polieletrólitos/síntese química , Polieletrólitos/química
20.
J Agric Food Chem ; 65(4): 950-963, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28072528

RESUMO

Triosephosphate isomerase (TIM) is a key enzyme in glycolysis and has been identified as an allergen in saltwater products. In this study, TIM with a molecular mass of 28 kDa was purified from the freshwater crayfish (Procambarus clarkii) muscle. A 90-kDa protein that showed IgG/IgE cross-reactivity with TIM was purified and identified as filamin C (FLN c), which is an actin-binding protein. TIM showed similar thermal and pH stability with better digestion resistance compared with FLN c. The result of the surface plasmon resonance (SPR) experiment demonstrated the infinity of anti-TIM polyclonal antibody (pAb) to both TIM and FLN c. Five linear and 3 conformational epitopes of TIM, as well as 9 linear and 10 conformational epitopes of FLN c, were mapped by phage display. Epitopes of TIM and FLN c demonstrated the sharing of certain residues; the occurrence of common epitopes in the two allergens accounts for their cross-reactivity.


Assuntos
Alérgenos/imunologia , Astacoidea/imunologia , Filaminas/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Frutos do Mar/análise , Triose-Fosfato Isomerase/imunologia , Alérgenos/química , Alérgenos/genética , Sequência de Aminoácidos , Animais , Astacoidea/química , Astacoidea/enzimologia , Astacoidea/genética , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Feminino , Filaminas/química , Filaminas/genética , Humanos , Imunoglobulina E/imunologia , Dados de Sequência Molecular , Coelhos , Alinhamento de Sequência , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/genética
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