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1.
Antioxidants (Basel) ; 10(7)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34356378

RESUMO

Two low-molecular-weight polysaccharides (GLP-1 and GLP-2) were purified from Ganoderma leucocontextum fruiting bodies, and their physicochemical properties and antioxidant activities were investigated and compared in this study. The results showed that GLP-1 and GLP-2 were mainly composed of mannose, glucose, galactose, xylose, and arabinose, with weight-average molecular weights of 6.31 and 14.07 kDa, respectively. Additionally, GLP-1 and GLP-2 had a similar chain conformation, crystal structure, and molecular surface morphology. Moreover, GLP-1 exhibited stronger antioxidant activities than GLP-2 in five different assays: 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radical, superoxide anion radical, ferric reducing antioxidant power (FRAP), and oxygen radical antioxidant capacity (ORAC). The main linkage types of GLP-1 were found to be →4)-α-D-Glcp-(1→, →4)-ß-D-Glcp-(1→, →3)-ß-D-Glcp-(1→, →6)-ß-D-Galp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and Glcp-(1→ by methylation analysis and nuclear magnetic resonance (NMR) spectroscopy. In addition, GLP-1 could protect NIH3T3 cells against tert-butyl hydroperoxide (tBHP)-induced oxidative damage by increasing catalase (CAT) and glutathione peroxidase (GSH-Px) activities, elevating the glutathione/oxidized glutathione (GSH/GSSG) ratio, and decreasing the malondialdehyde (MDA) level. These findings indicated that GLP-1 could be explored as a potential antioxidant agent for application in functional foods.

2.
Science ; 372(6548)2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34140356

RESUMO

Echolocation is the use of reflected sound to sense features of the environment. Here, we show that soft-furred tree mice (Typhlomys) echolocate based on multiple independent lines of evidence. Behavioral experiments show that these mice can locate and avoid obstacles in darkness using hearing and ultrasonic pulses. The proximal portion of their stylohyal bone fuses with the tympanic bone, a form previously only seen in laryngeally echolocating bats. Further, we found convergence of hearing-related genes across the genome and of the echolocation-related gene prestin between soft-furred tree mice and echolocating mammals. Together, our findings suggest that soft-furred tree mice are capable of echolocation, and thus are a new lineage of echolocating mammals.


Assuntos
Ecolocação , Roedores/fisiologia , Animais , Evolução Biológica , Osso e Ossos/anatomia & histologia , Quirópteros/anatomia & histologia , Quirópteros/fisiologia , Genoma , Audição/genética , Laringe/anatomia & histologia , Laringe/fisiologia , Mamíferos/anatomia & histologia , Mamíferos/genética , Mamíferos/fisiologia , Roedores/anatomia & histologia , Roedores/genética , Transportadores de Sulfato/genética , Osso Temporal/anatomia & histologia
3.
BMC Ecol Evol ; 21(1): 89, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34011264

RESUMO

BACKGROUND: The speckled-pelage brush-furred rats (Lophuromys flavopunctatus group) have been difficult to define given conflicting genetic, morphological, and distributional records that combine to obscure meaningful accounts of its taxonomic diversity and evolution. In this study, we inferred the systematics, phylogeography, and evolutionary history of the L. flavopunctatus group using maximum likelihood and Bayesian phylogenetic inference, divergence times, historical biogeographic reconstruction, and morphometric discriminant tests. We compiled comprehensive datasets of three loci (two mitochondrial [mtDNA] and one nuclear) and two morphometric datasets (linear and geometric) from across the known range of the genus Lophuromys. RESULTS: The mtDNA phylogeny supported the division of the genus Lophuromys into three primary groups with nearly equidistant pairwise differentiation: one group corresponding to the subgenus Kivumys (Kivumys group) and two groups corresponding to the subgenus Lophuromys (L. sikapusi group and L. flavopunctatus group). The L. flavopunctatus group comprised the speckled-pelage brush-furred Lophuromys endemic to Ethiopia (Ethiopian L. flavopunctatus members [ETHFLAVO]) and the non-Ethiopian ones (non-Ethiopian L. flavopunctatus members [NONETHFLAVO]) in deeply nested relationships. There were distinctly geographically structured mtDNA clades among the NONETHFLAVO, which were incongruous with the nuclear tree where several clades were unresolved. The morphometric datasets did not systematically assign samples to meaningful taxonomic units or agree with the mtDNA clades. The divergence dating and ancestral range reconstructions showed the NONETHFLAVO colonized the current ranges over two independent dispersal events out of Ethiopia in the early Pleistocene. CONCLUSION: The phylogenetic associations and divergence times of the L. flavopunctatus group support the hypothesis that paleoclimatic impacts and ecosystem refugia during the Pleistocene impacted the evolutionary radiation of these rodents. The overlap in craniodental variation between distinct mtDNA clades among the NONETHFLAVO suggests unraveling underlying ecomorphological drivers is key to reconciling taxonomically informative morphological characters. The genus Lophuromys requires a taxonomic reassessment based on extensive genomic evidence to elucidate the patterns and impacts of genetic isolation at clade contact zones.


Assuntos
DNA Mitocondrial , Ecossistema , Animais , Teorema de Bayes , DNA Mitocondrial/genética , Etiópia , Filogenia , Ratos
4.
Zool Res ; 42(1): 100-107, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33258336

RESUMO

In this study, we reassessed the taxonomic position of Typhlomys (Rodentia: Platacanthomyidae) from Huangshan, Anhui, China, based on morphological and molecular evidence. Results suggested that Typhlomys is comprised of up to six species, including four currently recognized species ( Typhlomys cinereus, T. chapensis, T. daloushanensis, and T. nanus), one unconfirmed candidate species, and one new species ( Typhlomys huangshanensis sp. nov.). Morphological analyses further supported the designation of the Huangshan specimens found at mid-elevations in the southern Huangshan Mountains (600 m to 1 200 m a.s.l.) as a new species.


Assuntos
Roedores/anatomia & histologia , Roedores/genética , Distribuição Animal , Animais , Feminino , Masculino , Roedores/classificação , Especificidade da Espécie
5.
Zool Res ; 41(6): 670-683, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-32918407

RESUMO

The interpretation of patterns of biodiversity requires the disentanglement of geographical and environmental variables. Disjunct alpine communities are geographically isolated from one another but experience similar environmental impacts. Isolated homogenous habitats may promote speciation but constrain functional trait variation. In this study, we examined the hypothesis that dispersal limitation promotes taxonomic divergence, whereas habitat similarity in alpine mountains leads to functional convergence. We performed standardized field investigation to sample non-volant small mammals from 18 prominent alpine sites in the Three Parallel Rivers area. We estimated indices quantifying taxonomic and functional alpha- and beta-diversity, as well as beta-diversity components. We then assessed the respective importance of geographical and environmental predictors in explaining taxonomic and functional compositions. No evidence was found to show that species were more functionally similar than expected in local assemblages. However, the taxonomic turnover components were higher than functional ones (0.471±0.230 vs. 0.243±0.215), with nestedness components showing the opposite pattern (0.063±0.054 vs. 0.269±0.225). This indicated that differences in taxonomic compositions between sites occurred from replacement of functionally similar species. Geographical barriers were the key factor influencing both taxonomic total dissimilarity and turnover components, whereas functional beta-diversity was primarily explained by climatic factors such as minimum temperature of the coldest month. Our findings provide empirical evidence that taxonomic and functional diversity patterns can be independently driven by different ecological processes. Our results point to the importance of clarifying different components of beta-diversity to understand the underlying mechanisms of community assembly. These results also shed light on the assembly rules and ecological processes of terrestrial mammal communities in extreme environments.


Assuntos
Genoma Mitocondrial , Presbytini/genética , Distribuição Animal , Animais , Ásia , DNA/genética , Fezes/química , Feminino , Masculino , Filogenia , Especificidade da Espécie
6.
Carbohydr Polym ; 249: 116874, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32933694

RESUMO

Ganoderma leucocontextum is a new species of Ganoderma discovered in 2014. Up to now, the structural characteristics and immunoregulatory activity of its polysaccharides remain virtually unknown. In this study, a water-soluble polysaccharide termed, GLP-3, was purified from G. leucocontextum by ultrafiltration and column chromatography. The results revealed that GLP-3 mainly consisted of glucose (92.7 %) and its weight average molecular weight was 159.7 kDa. The structural analysis indicated that the backbone of GLP-3 was →4)-α-D-Glcp-(1→4,6)-ß-D-Glcp-(1→ with a ß-Glcp-(1→ branch. Atomic force microscopy and Congo red experiments revealed that GLP-3 might possess a globular structure with triple-helix conformation in water. Moreover, GLP-3 was recognized by toll-like receptor 2 (TLR2) and exerted immunomodulatory effects via activating mitogen-activated protein kinases (MAPKs), phosphatidylinositol-3-kinase (PI3K)/Akt and nuclear factor-κB (NF-κB) signaling pathways in RAW 264.7 macrophages. Collectively, these results suggested that GLP-3 could be developed as a potential functional food ingredient for immunomodulation.


Assuntos
Carpóforos/química , Ganoderma/química , Imunomodulação , Macrófagos/imunologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Animais , Macrófagos/efeitos dos fármacos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Células RAW 264.7 , Transdução de Sinais , Receptor 2 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
7.
Plant Physiol Biochem ; 155: 549-559, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32846390

RESUMO

Flavonoid biosynthesis is a crucial secondary metabolism process for tea plants. Its metabolism is affected by multiple environmental factors, especially light. Shade, also known as dark stress (DS), is generally used during cultivation to improve tea quality by influencing the flavonoid accumulation. To explore the molecular mechanisms of flavonoid biosynthesis under DS, metabolomics and transcriptomics (METR) analyses were performed in tea callus via culturing the plants in vitro using 12 h light/12 h dark cycles (A) or completely dark (B) conditions for 30 days. In total, 161 differential metabolic products (DMPs) and 3592 differential expression genes (DEGs) were identified. The major flavonoids including epicatechin gallate, catechin gallate, gallocatechin-catechin, cyanidin 3-O-glucoside and the total of catechin, anthocyanin and proanthocyanidin contents were all remarkably down-regulated in tea callus under DS. Meanwhile, 9 genes including CsPAL, Cs4CL, CsCHS, CsFLS, CsDFR, CsANS, CsLAR, CsANR, and CsUFGT determined to be responsible for the flavonoid biosynthesis. In addition, 2 transcription factors (TFs) including CsMYBT1 and CsMYBT2 verified to play key role in regulation the flavonoid biosynthesis. These results helped us further understand the underlying molecular mechanism of flavonoid metabolism in tea plants.


Assuntos
Camellia sinensis , Escuridão , Flavonoides/biossíntese , Camellia sinensis/metabolismo , Camellia sinensis/efeitos da radiação , Catequina , Regulação da Expressão Gênica de Plantas , Metaboloma , Proteínas de Plantas/metabolismo , Transcriptoma
8.
Appl Opt ; 59(2): 459-462, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32225331

RESUMO

A void-free bonding technique was demonstrated for a large slab Nd: YAG crystal with a bonding surface dimension of ∼160mm×70mm. By using the novel fluxless oxide layer removal technology, the indium-oxide barrier problem was resolved. With the help of electrochemical-polished indium solder and a plasma-cleaned heat sink, the solderability of the indium was enhanced; in particular, the contact angle of the solder was improved from 51° to 31°. With the largest-bonding-size slab, a single-slab laser created a maximum output power of 7.3 kW under an absorbed pump power of 12.8 kW, corresponding to an optical to optical efficiency of 57% and a slope conversion of 67.8%. By detecting the wavefront of the interferometer before and after bonding, the RMS of wavefront was 0.192λ and 0.434λ (λ=633nm), respectively. To the best of our knowledge, this is the largest void-free bonding size for a laser slab and the highest output power achieved from a single-slab crystal laser oscillator.

9.
Opt Express ; 28(6): 8056-8063, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32225438

RESUMO

An adjustable slab-aberration compensator (ASAC) with the ability to compensate the large magnitude inherent wavefront aberrations in the slab width direction is proposed and experimentally demonstrated. The ASAC has a size of 130mm×45mm (effective aperture of 75mm×28mm) and 11 actuators along the length with a contact spacing of 8 mm. The design is optimized by simulations in terms of the mirror's coupling coefficient with the contact areas, mechanical properties of the driving units, and the mirror thickness. The initial surface figure of the ASAC has PV and RMS values of 55 nm and 10 nm, and the dynamic range is 30 µm. In our experiments, a 20 kW Nd: YAG quasi-continuous wave (QCW) slab laser is further compensated by the ASAC system. The beam quality increases from 15× to 3.5× diffraction limit at 20 kW output after correction. Besides, the proposed ASAC can maintain the surface shape after power shutdown and have good thermal stability. The temperature rise of the ASAC is less than 7 °C in the 20 kW laser correction experiment.

10.
Ecol Evol ; 10(5): 2545-2558, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32185000

RESUMO

Understanding the species diversity patterns along elevational gradients is critical for biodiversity conservation in mountainous regions. We examined the elevational patterns of species richness and turnover, and evaluated the effects of spatial and environmental factors on nonvolant small mammals (hereafter "small mammal") predicted a priori by alternative hypotheses (mid-domain effect [MDE], species-area relationship [SAR], energy, environmental stability, and habitat complexity]) proposed to explain the variation of diversity. We designed a standardized sampling scheme to trap small mammals at ten elevational bands across the entire elevational gradient on Yulong Mountain, southwest China. A total of 1,808 small mammals representing 23 species were trapped. We observed the hump-shaped distribution pattern of the overall species richness along elevational gradient. Insectivores, rodents, large-ranged species, and endemic species richness showed the general hump-shaped pattern but peaked at different elevations, whereas the small-ranged species and endemic species favored the decreasing richness pattern. The MDE and the energy hypothesis were supported, whereas little support was found for the SAR, the environmental stability hypothesis, and the habitat complexity. However, the primary driver(s) for richness patterns differed among the partitioning groups, with NDVI (the normalized difference vegetation index) and MDE being the most important variables for the total richness pattern. Species turnover for all small mammal groups increased with elevation, and it supported a decrease in community similarity with elevational distance. Our results emphasized for increased conservation efforts in the higher elevation regions of the Yulong Mountain.

11.
Opt Lett ; 45(5): 1136-1139, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32108789

RESUMO

A 24.6 kW quasi-continuous-wave (QCW) Nd-doped yttrium aluminum garnet (Nd:YAG) slab laser is proposed in this Letter. The laser is based on a stable-unstable hybrid cavity. A stable and an unstable resonator were constructed along orthogonal directions in the aperture of the slab. Due to features of the hybrid cavity, the slab laser achieves both high efficiency of power extraction with excellent beam quality and compactness with simplicity. Average output power of 24.6 kW with 47% optical-to-optical efficiency is achieved in the experiment. The beam quality of the output beam is 1.5 times diffraction limits after correction of adaptive optics. The repetition frequency and pulse width of the laser are 400 Hz and 200 µs.

12.
Food Res Int ; 129: 108854, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32036895

RESUMO

Cocoa tea (Camellia ptilophylla), a natural gallocatechin gallate (GCG)-rich and low caffeine-containing tea species, has been recently reported to possess various bioactivities. However, the anti-colon cancer effects of Cocoa tea and its underlying mechanisms remain virtually unknown. This study aimed to assess the anti-proliferative and pro-apoptotic effects of water extract of Cocoa tea (CWE) on human colon cancer HCT116 cells compared with Yunnan Daye tea (YWE). Primarily, CWE showed stronger anti-proliferation and apoptosis induction than YWE. Moreover, reduction of mitochondrial membrane potential (MMP), up-regulation of Bax/Bcl-2 ratio, release of cytochrome c, activation of caspase-9 and -3, and cleavage of poly (ADP-ribose) polymerase (PARP) were observed, suggesting that mitochondrial apoptotic pathway was activated by CWE. Furthermore, CWE-induced apoptosis in HCT116 cells was dependent on the generation of intracellular reactive oxygen species (ROS) and down-regulation of phosphatidylinositol-3-kinase (PI3K)/Akt pathway. Pretreatment with ROS scavenger N-acetyl cysteine (NAC) attenuated the impact of CWE on mitochondria-related apoptosis proteins, and partially recovered the inhibition of Akt phosphorylation. These results indicated that ROS generation mediated mitochondrial dysfunction and inactivation of PI3K/Akt pathway in CWE-induced HCT116 cell apoptosis. Additionally, CWE significantly inhibited tumor growth in HCT116 tumor-bearing mice, suggesting that Cocoa tea could act as a potential functional beverage to prevent or treat colorectal cancer.


Assuntos
Apoptose/efeitos dos fármacos , Camellia/classificação , Mitocôndrias/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Bebidas/análise , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética
13.
Int J Biol Macromol ; 152: 605-615, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32087224

RESUMO

Selenium nanoparticles (SeNPs), a novel selenium form, have attracted worldwide attention due to their bioactivities and low toxicity. This study aimed to assess the physicochemical characterization, storage stability, and anti-proliferative activities of SeNPs stabilized by Polyporus umbellatus polysaccharide (PUP). Results showed that orange-red, zero-valent, amorphous and spherical SeNPs with mean diameter of approximately 82.5 nm were successfully prepared by using PUP as a capping agent. PUP-SeNPs solution stored at 4 °C in dark condition could be stable for at least 84 days. Moreover, PUP-SeNPs treatment inhibited four cancer cell lines proliferation in a dose-dependent manner, while no significant cytotoxicity towards three normal cell lines was observed. Comparing with the other cancer cell lines (HepG2, Hela, and HT29), PUP-SeNPs displayed the most sensitive towards MDA-MB-231 cells with an IC50 value of 6.27 µM. Furthermore, PUP-SeNPs significantly up-regulated Bax/Bcl-2 ratio, promoted cytochrome c release, increased caspase-9, -8 and -3 activities, and poly (ADP-ribose) polymerase cleavage, suggesting that mitochondria-mediated and death receptor-mediated apoptotic pathways were activated in MDA-MB-231 cells. Besides, PUP-SeNPs possessed better anti-proliferative activity than selenomethionine as well as lower cytotoxicity than sodium selenite. Taken together, PUP-SeNPs have strong potential as a dietary supplement for application in cancer chemoprevention, especially breast cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , Nanopartículas/química , Polyporus/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Selênio/química , Selênio/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Células HEK293 , Células HT29 , Células HeLa , Células Hep G2 , Humanos , Camundongos , Mitocôndrias/efeitos dos fármacos , Células NIH 3T3
14.
Int J Biol Macromol ; 151: 247-256, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32057881

RESUMO

Food-grade Pickering emulsions have attracted lots of researchers' attention. As one type of food-grade particles, tea water-insoluble protein nanoparticles (TWIPN) from tea residues were utilized to prepare Pickering emulsions at an oil-water ratio of 6: 4 (v/v) via high-pressure homogenization (HPH). Characteristics and rheological behavior of TWIPN-stabilized Pickering emulsions (TWIPNPE) were analyzed. The size of TWIPNPE significantly decreased with the increase of homogenization pressure (0-80 MPa) and homogenization times. However, the droplet size of TWIPNPE at 120 MPa significantly increased compared to that at 80 MPa. Furthermore, the droplet size and zeta potential of TWIPNPE prepared at a fixed homogenization pressure of 40 MPa reduced in comparison with those prepared via high-speed homogenization at the same TWIPN concentration (0.5-4.0%). Besides, the emulsions prepared at the TWIPN concentration of 3.0% and 4.0% had no creaming within 50 days. Additionally, HPH improved the gel-like behavior of TWIPNPE. These results suggest that the TWIPNPE have the potential for preparing the high viscoelastic system for the food industry to expand the utility of tea leave byproducts.


Assuntos
Emulsões , Nanopartículas/química , Proteínas de Plantas/química , Pressão , Reologia , Chá/química , Água/química , Tamanho da Partícula , Solubilidade
15.
Zool Res ; 40(1): 53-60, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30581186

RESUMO

The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals (hereafter 'small mammals') on Mt. Kenya, the second tallest mountain in Africa, using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern (Chogoria) and western (Sirimon) slopes. A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights. Abundance was highest at mid-elevations on both slopes. However, species richness and distribution patterns differed between the two slopes. More species were recorded on Chogoria (24) than on Sirimon (17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation (2 800 m a.s.l.), whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya's mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of small mammal diversity in mountain habitats in Africa.


Assuntos
Distribuição Animal , Biodiversidade , Mamíferos , Altitude , Animais , Quênia , Densidade Demográfica
16.
Zool Res ; 40(1): 3-52, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30348934

RESUMO

Kenya has a rich mammalian fauna. We reviewed recently published books and papers including the six volumes of Mammals of Africa to develop an up-to-date annotated checklist of all mammals recorded from Kenya. A total of 390 species have been identified in the country, including 106 species of rodents, 104 species of bats, 63 species of even-toed ungulates (including whales and dolphins), 36 species of insectivores and carnivores, 19 species of primates, five species of elephant shrews, four species of hyraxes and odd-toed ungulates, three species of afrosoricids, pangolins, and hares, and one species of aardvark, elephant, sirenian and hedgehog. The number of species in this checklist is expected to increase with additional surveys and as the taxonomic status of small mammals (e.g., bats, shrews and rodents) becomes better understood.


Assuntos
Distribuição Animal , Biodiversidade , Mamíferos , Animais , Quênia
17.
Zool Res ; 39(5): 335-347, 2018 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-29695683

RESUMO

Hedgehogs in the genus Mesechinus (Family Erinaceidae), which include two currently recognized species (M. dauuricus and M. hughi), are distributed from northeast Mongolia to the upper Amur Basin in Russia and adjacent areas in northeast and northern China. In recent years, a population of Mesechinus hedgehogs was discovered from Mt. Gaoligong, southwestern Yunnan, China, far from the known distribution range of the genus. Furthermore, these hedgehogs are the only known population to be distributed at elevations higher than 2 100 m and in sympatry with gymnures. To evaluate the taxonomic status of these hedgehogs, we examined specimens representing Mesechinus taxa in China and further conducted morphometric and karyotypic analyses. Our results supported the existence of four species in China. Specifically, we identified the hedgehogs from Mt. Gaoligong as a new species, Mesechinus wangi sp. nov., and recognized M. miodon, previously considered as a synonym of either M. dauuricus or M. hughi, as a distinct species. Interestingly, we observed a supernumerary M4 on all specimens of Mesechinus wangi sp. nov., which is an extremely rare event in the evolution of mammalian dentition.


Assuntos
Ouriços-Cacheiros/classificação , Animais , China , Demografia , Ecossistema , Ouriços-Cacheiros/anatomia & histologia , Ouriços-Cacheiros/genética , Cariotipagem , Mongólia , Sibéria
18.
Carbohydr Polym ; 184: 164-170, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29352907

RESUMO

Microcrystalline cellulose (MCC) was prepared from Oolong tea waste by acid hydrolysis in the present study. Based on the single factor experiment results, the hydrolysis conditions were optimized by an orthogonal L9(3)4 experiment. Results showed that the degree of polymerization (DP) and yield of MCC were strongly influenced by the time and temperature of hydrolysis, the concentration of HCl and the ratio of acid to material. Under optimal conditions (acid to materials ratio 1:20, HCl concentration 1.5 mol/L, 65 °C, 90 min), the yield and DP of the tea waste MCC were 86.7% and 145, respectively. Fourier transform-infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis indicated that tea waste MCC had cellulosic structure and was cellulose I type. Scanning electron microscopy (SEM) showed that MCC had shorter fibers with some holes on the rough surface. The MCC prepared from tea waste had good thermal stability.

19.
J Food Sci ; 83(2): 517-524, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29337349

RESUMO

Zijuan tea (Camellia sinensis var. assamica) is a unique anthocyanin-rich tea cultivar in China. Although chemical component analysis of Zijuan tea and extraction technology of anthocyanins was widely documented, its functional properties have not been extensively explored. In this study, the anti-inflammatory, antiproliferative, and methylglyoxal (MGO) trapping activities of water extract (ZWE) and ethyl acetate extract (ZEE) of Zijuan tea were investigated for the 1st time. Results showed that ZWE and ZEE exhibited inhibitory effects on nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 production as well as inducible nitric oxide synthase protein (iNOS) expression in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Moreover, Zijuan tea extracts exerted stronger antiproliferative activity against HCT-116 cells compared with HepG2 and MDA-MB-231 cells, and thus could induce apoptosis in HCT-116 cells in a dose-dependent manner. Furthermore, Zijuan tea extracts were effective in trapping MGO under simulated physiological conditions, and the T1/2 (the time for 50% MGO remaining) values of ZWE and ZEE were 3.69 and 6.20 min, respectively. Additionally, the contents of total phenolics and catechins in ZEE were 685.43 ± 16.00 and 454.96 ± 4.21 mg/g extract, respectively, and in ZWE were 422.59 ± 12.09 and 307.29 ± 0.85 mg/g extract, respectively. Therefore, ZEE exhibited better anti-inflammatory, antiproliferative, and MGO trapping properties than ZWE may be mainly attributed to its higher (P < 0.05) content of total phenolics, expecially catechins. These results suggest that Zijuan tea could be a potential natural resource for the development of functional tea beverage. PRACTICAL APPLICATION: This study revealed that Zijuan tea extracts possessed anti-inflammatory, antiproliferative, and methylglyoxal trapping potentials in vitro. With high anthocyanins and polyphenols, Zijuan tea can be developed into a healthy tea beverage or used as a natural component to reduce the level of methylglyoxal in Maillard reaction.


Assuntos
Anti-Inflamatórios/farmacologia , Camellia sinensis/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Aldeído Pirúvico/química , Animais , Antocianinas/química , Antocianinas/farmacologia , Anti-Inflamatórios/química , Catequina/química , Catequina/farmacologia , Proliferação de Células/efeitos dos fármacos , Células HCT116 , Humanos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Óxido Nítrico/imunologia , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/imunologia , Compostos Fitoquímicos/química , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologia , Células RAW 264.7 , Chá/química , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
20.
Sci Rep ; 7(1): 13277, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-29038588

RESUMO

The species richness patterns of small mammals and the processes shaping them in two gradients of a mountain with different spatial and climatic characteristics were examined using standard sampling scheme. We trapped 2,006 small mammals representing 37 species, along elevational gradients on both western and eastern slopes of the Ailao Mountains, Southwest China. Using mid-domain effect model, model selection and model averaging, we examined the effects of slope, area, mean annual temperature (MAT), mean annual humidity (MAH), productivity, plant species richness (PSR) and the mid-domain effect (MDE) on the patterns of small mammal diversity. The hump-shaped patterns were favored along the elevational gradient, but shapes of diversity curves were different on the contrasting slopes. Area and productivity were the most important factors in explaining the variation of total species richness. However, for each specific group of small mammals (i.e. insectivores vs. rodents, large-ranged vs. small-ranged species, endemic vs. non-endemic species), the peaks of species richness and their primary drivers varied. The major explanatory factors for richness pattern of each small mammal group were not significantly different between the slopes, suggesting the existence of the general underlying mechanisms on two slopes of a mountain.


Assuntos
Biodiversidade , Ecossistema , Meio Ambiente , Mamíferos , Animais , China , Evolução Molecular , Modelos Teóricos , Seleção Genética
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