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1.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33558418

RESUMO

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.


Assuntos
Arqueologia , Cavernas/química , DNA Antigo/análise , Fósseis , Sedimentos Geológicos/análise , Migração Humana/história , Datação Radiométrica/métodos , China , História Antiga , Humanos
2.
J Anat ; 242(5): 927-952, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36680380

RESUMO

The vertebrate trigeminal nerve is the primary mediator of somatosensory information from nerve endings across the face, extending nerve branches through bony canals in the face and mandibles, terminating in sensory receptors. Reptiles evolved several extreme forms of cranial somatosensation in which enhanced trigeminal tissues are present in species engaging in unique mechanosensory behaviors. However, morphology varies by clade and ecology among reptiles. Few lineages approach the extreme degree of tactile somatosensation possessed by crocodylians, the only remaining members of a clade that underwent an ecological transition from the terrestrial to semiaquatic habitat, also evolving a specialized trigeminal system. It remains to be understood how trigeminal osteological correlates inform how adaptations for enhanced cranial sensation evolved in crocodylians. Here we identify an increase in sensory abilities in Early Jurassic crocodylomorphs, preceding the transitions to a semiaquatic habitat. Through quantification of trigeminal neurovascular canal branching patterns in an extant phylogenetic bracket we quantify and identify morphologies associated with sensory behaviors in representative fossil taxa, we find stepwise progression of increasing neurovascular canal density, complexity, and distribution from the primitive archosaurian to the derived crocodilian condition. Model-based inferences of sensory ecologies tested on quantified morphologies of extant taxa with known sensory behaviors indicate a parallel increase in sensory abilities among pseudosuchians. These findings establish patterns of reptile trigeminal ecomorphology, revealing evolutionary patterns of somatosensory ecology.


Assuntos
Jacarés e Crocodilos , Evolução Biológica , Animais , Filogenia , Nervo Trigêmeo , Crânio/anatomia & histologia
3.
Nano Lett ; 21(12): 5308-5315, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34076433

RESUMO

Friction and wear are the main reasons for decreasing the lifetime of moving mechanical components and causing energy loss. It is desirable to achieve macroscale superlubricity on industrial materials for minimizing friction. Herein, the two-dimensional material black phosphorus (BP) is prepared as an oil-based nanoadditive in oleic acid (OA) and shown to produce macroscale superlubricity at the steel/steel contact under high pressure. Experiments and molecular dynamics simulation reveal that BP quickly captures the carboxylic group and, as a result of the high contact pressure and heat, OA decomposes to release passivating species and recombines to form amorphous carbon giving rise to a composite solid tribofilm with BP. The OA and passivating groups adsorb onto the solid tribofilm to produce the passivating layer, thus resulting in macroscale superlubricity. The findings provide fundamental insight into the nature of tribochemical mechanisms and suggest a new approach to achieve macroscale superlubricity of industrial materials.


Assuntos
Fósforo , Aço , Fricção
4.
J Nanobiotechnology ; 19(1): 140, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001157

RESUMO

Synergistic chemo-photodynamic therapy has garnered attention in the field of cancer treatment. Here, a pH cascade-responsive micellar nanoplatform with nucleus-targeted ability, for effective synergistic chemo-photodynamic cancer treatment, was fabricated. In this micellar nanoplatform, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (Por), a photodynamic therapy (PDT) agent was utilized for carrying the novel anticancer drug GNA002 to construct a hydrophobic core, and cyclic RGD peptide (cRGD)-modified polyethylene glycol (PEG) (cRGD-PEG) connected the cell-penetrating peptide hexaarginine (R6) through a pH-responsive hydrazone bond (cRGD-PEG-N = CH-R6) to serve as a hydrophilic shell for increasing blood circulation time. After passively accumulating in tumor sites, the self-assembled GNA002-loaded nanoparticles were actively internalized into cancer cells via the cRGD ligands. Once phagocytosed by lysosomes, the acidity-triggered detachment of the cRGD-PEG shell led to the formation of R6-coated secondary nanoparticles and subsequent R6-mediated nucleus-targeted drug delivery. Combined with GNA002-induced nucleus-specific chemotherapy, reactive oxygen species produced by Por under 532-nm laser irradiation achieved a potent synergistic chemo-photodynamic cancer treatment. Moreover, our in vitro and in vivo anticancer investigations revealed high cancer-suppression efficacy of this ideal multifunctional nanoplatform, indicating that it could be a promising candidate for synergistic anticancer therapy.


Assuntos
Antineoplásicos/uso terapêutico , Portadores de Fármacos/química , Neoplasias/terapia , Fotoquimioterapia/métodos , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Lisossomos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/química , Peptídeos Cíclicos , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis/química , Espécies Reativas de Oxigênio
5.
Proc Natl Acad Sci U S A ; 114(41): 10930-10935, 2017 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-28973883

RESUMO

Beaks are innovative structures characterizing numerous tetrapod lineages, including birds, but little is known about how developmental processes influenced the macroevolution of these important structures. Here we provide evidence of ontogenetic vestigialization of alveoli in two lineages of theropod dinosaurs and show that these are transitional phenotypes in the evolution of beaks. One of the smallest known caenagnathid oviraptorosaurs and a small specimen of the Early Cretaceous bird Sapeornis both possess shallow, empty vestiges of dentary alveoli. In both individuals, the system of vestiges connects via foramina with a dorsally closed canal homologous to alveoli. Similar morphologies are present in Limusaurus, a beaked theropod that becomes edentulous during ontogeny; and an analysis of neontological and paleontological evidence shows that ontogenetic reduction of the dentition is a relatively common phenomenon in vertebrate evolution. Based on these lines of evidence, we propose that progressively earlier postnatal and embryonic truncation of odontogenesis corresponds with expansion of rostral keratin associated with the caruncle, and these progenesis and peramorphosis heterochronies combine to drive the evolution of edentulous beaks in nonavian theropods and birds. Following initial apomorphic expansion of rostral keratinized epithelia in perinatal toothed theropods, beaks appear to inhibit odontogenesis as they grow postnatally, resulting in a sequence of common morphologies. This sequence is shifted earlier in development through phylogeny until dentition is absent at hatching, and odontogenesis is inhibited by beak formation in ovo.


Assuntos
Bico/anatomia & histologia , Evolução Biológica , Aves/anatomia & histologia , Dinossauros/anatomia & histologia , Odontogênese/fisiologia , Crânio/anatomia & histologia , Dente/anatomia & histologia , Animais , Bico/fisiologia , Aves/fisiologia , Dinossauros/fisiologia , Fósseis , Morfogênese , Paleontologia , Filogenia , Crânio/fisiologia , Dente/fisiologia
6.
J Environ Sci (China) ; 51: 305-314, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28115142

RESUMO

In this study, a new and facile route was employed for synthesis of polyamidine with abundant cations and attractive five-membered ringlike structural unit. N-vinylformamide and acrylonitrile copolymerized firstly to form intermediates, and the intermediates were processed with hydrochloric acid to produce polyamidine. A series of polymerization conditions (e.g. polymerization time, temperature and dosage of initiator) were optimized through productivity, viscosity and cationic degree as evaluation. SEM analysis illustrated that the amidinization process could reduce the size of spaces between molecular and created compact structure, which would contribute to good flocculation performance and high viscosity. FT-IR, XPS and NMR spectra presented a rather clear structure of polyamidine. 34.3% of sludge was sedimentated through the flocculation of polyamidine in the early stages. In contrast, only 6.8% of sludge was sedimentated by polyacrylamide. The moisture content in dehydrated floc could be reduced to 77.7% when 60mg/L polyamidine was added. These results demonstrated that the polyamidine showed a great potential in the practical application of sludge dewatering.


Assuntos
Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Acrilonitrila/química , Cátions , Dessecação/métodos , Floculação , Polimerização , Polímeros , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade
7.
BMC Evol Biol ; 16(1): 236, 2016 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-27793089

RESUMO

BACKGROUND: Turtles (Testudinata) are a successful lineage of vertebrates with about 350 extant species that inhabit all major oceans and landmasses with tropical to temperate climates. The rich fossil record of turtles documents the adaptation of various sub-lineages to a broad range of habitat preferences, but a synthetic biogeographic model is still lacking for the group. RESULTS: We herein describe a new species of fossil turtle from the Late Jurassic of Xinjiang, China, Sichuanchelys palatodentata sp. nov., that is highly unusual by plesiomorphically exhibiting palatal teeth. Phylogenetic analysis places the Late Jurassic Sichuanchelys palatodentata in a clade with the Late Cretaceous Mongolochelys efremovi outside crown group Testudines thereby establishing the prolonged presence of a previously unrecognized clade of turtles in Asia, herein named Sichuanchelyidae. In contrast to previous hypotheses, M. efremovi and Kallokibotion bajazidi are not found within Meiolaniformes, a clade that is here reinterpreted as being restricted to Gondwana. CONCLUSIONS: A revision of the global distribution of fossil and recent turtle reveals that the three primary lineages of derived, aquatic turtles, including the crown, Paracryptodira, Pan-Pleurodira, and Pan-Cryptodira can be traced back to the Middle Jurassic of Euramerica, Gondwana, and Asia, respectively, which resulted from the primary break up of Pangaea at that time. The two primary lineages of Pleurodira, Pan-Pelomedusoides and Pan-Chelidae, can similarly be traced back to the Cretaceous of northern and southern Gondwana, respectively, which were separated from one another by a large desert zone during that time. The primary divergence of crown turtles was therefore driven by vicariance to the primary freshwater aquatic habitat of these lineages. The temporally persistent lineages of basal turtles, Helochelydridae, Meiolaniformes, Sichuanchelyidae, can similarly be traced back to the Late Mesozoic of Euramerica, southern Gondwana, and Asia. Given the ambiguous phylogenetic relationships of these three lineages, it is unclear if their diversification was driven by vicariance as well, or if they display a vicariance-like pattern. The clean, primary signal apparent among early turtles is secondarily obliterated throughout the Late Cretaceous to Recent by extensive dispersal of continental turtles and by multiple invasions of marine habitats.


Assuntos
Fósseis , Internacionalidade , Filogeografia , Tartarugas/classificação , Exoesqueleto/anatomia & histologia , Animais , China , Paleontologia , Filogenia , Crânio/anatomia & histologia , Fatores de Tempo , Dente
8.
BMC Ecol Evol ; 24(1): 46, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627692

RESUMO

BACKGROUND: Tooth replacement patterns of early-diverging ornithischians, which are important for understanding the evolution of the highly specialized dental systems in hadrosaurid and ceratopsid dinosaurs, are poorly known. The early-diverging neornithischian Jeholosaurus, a small, bipedal herbivorous dinosaur from the Early Cretaceous Jehol Biota, is an important taxon for understanding ornithischian dental evolution, but its dental morphology was only briefly described previously and its tooth replacement is poorly known. RESULTS: CT scanning of six specimens representing different ontogenetic stages of Jeholosaurus reveals significant new information regarding the dental system of Jeholosaurus, including one or two replacement teeth in nearly all alveoli, relatively complete tooth resorption, and an increase in the numbers of alveoli and replacement teeth during ontogeny. Reconstructions of Zahnreihen indicate that the replacement pattern of the maxillary dentition is similar to that of the dentary dentition but with a cyclical difference. The maxillary tooth replacement rate in Jeholosaurus is probably 46 days, which is faster than that of most other early-diverging ornithischians. During the ontogeny of Jeholosaurus, the premaxillary tooth replacement rate slows from 25 days to 33 days with similar daily dentine formation. CONCLUSIONS: The tooth replacement rate exhibits a decreasing trend with ontogeny, as in Alligator. In a phylogenetic context, fast tooth replacement and multi-generation replacement teeth have evolved at least twice independently in Ornithopoda, and our analyses suggest that the early-diverging members of the major ornithischian clades exhibit different tooth replacement patterns as an adaption to herbivory.


Assuntos
Dinossauros , Dente , Animais , Filogenia , Dinossauros/anatomia & histologia , Herbivoria , Fósseis , Dente/diagnóstico por imagem , Dente/cirurgia , Dente/anatomia & histologia
9.
Anat Rec (Hoboken) ; 307(5): 1897-1917, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37772730

RESUMO

Tyrannosaurus has been an exemplar organism in feeding biomechanical analyses. An adult Tyrannosaurus could exert a bone-splintering bite force, through expanded jaw muscles and a robust skull and teeth. While feeding function of adult Tyrannosaurus has been thoroughly studied, such analyses have yet to expand to other tyrannosauroids, especially early-diverging tyrannosauroids (Dilong, Proceratosaurus, and Yutyrannus). In our analysis, we broadly assessed the cranial and feeding performance of tyrannosauroids at varying body sizes. Our sample size included small (Proceratosaurus and Dilong), medium-sized (Teratophoneus), and large (Tarbosaurus, Daspletosaurus, Gorgosaurus, and Yutyrannus) tyrannosauroids, and incorporation of tyrannosaurines at different ontogenetic stages (small juvenile Tarbosaurus, Raptorex, and mid-sized juvenile Tyrannosaurus). We used jaw muscle force calculations and finite element analysis to comprehend the cranial performance of our tyrannosauroids. Scaled subtemporal fenestrae areas and calculated jaw muscle forces show that broad-skulled tyrannosaurines (Tyrannosaurus, Daspletosaurus, juvenile Tyrannosaurus, and Raptorex) exhibited higher jaw muscle forces than other similarly sized tyrannosauroids (Gorgosaurus, Yutyrannus, and Proceratosaurus). The large proceratosaurid Yutyrannus exhibited lower cranial stress than most adult tyrannosaurids. This suggests that cranial structural adaptations of large tyrannosaurids maintained adequate safety factors at greater bite force, but their robust crania did not notably decrease bone stress. Similarly, juvenile tyrannosaurines experienced greater cranial stress than similarly-sized earlier tyrannosauroids, consistent with greater adductor muscle forces in the juveniles, and with crania no more robust than in their small adult predecessors. As adult tyrannosauroid body size increased, so too did relative jaw muscle forces manifested even in juveniles of giant adults.


Assuntos
Força de Mordida , Fósseis , Fenômenos Biomecânicos , Crânio/anatomia & histologia , Músculo Esquelético
10.
Zootaxa ; 3640: 242-57, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26000415

RESUMO

This paper describes a new oviraptorid dinosaur taxon, Ganzhousaurus nankangensis gen. et sp. nov., based on a specimen collected from the Upper Cretaceous Nanxiong Formation of Nankang County, Ganzhou City, Jiangxi Province, southern China. This new taxon is distinguishable from other oviraptorids based on the following unique combination of primitive and derived features: relatively shallow dentary; absence of fossa or pneumatopore on lateral surface of dentary; weakly downturned anterior mandibular end; shallow depression immediately surrounding anterior margin of external mandibular fenestra; external mandibular fenestra subdivided by anterior process of surangular; dentary posteroventral process slightly twisted and positioned on mandibular ventrolateral surface; shallow longitudinal groove along medial surface of dentary posteroventral process; angular anterior process wider transversely than deep dorsoventrally; sharp groove along ventrolateral surface of angular anterior process; ventral border of external mandibular fenestra formed mainly by angular; ventral flange along distal half of metatarsal II; and arctometatarsal condition absent. Phylogenetic analysis places Ganzhousaurus nankangensis gen. et sp. nov. in the clade Oviraptoridae, together with Oviraptor, Citipati, Rinchenia and the unnamed Zamyn Khondt oviraptorid.


Assuntos
Dinossauros/classificação , Animais , China , Dinossauros/anatomia & histologia , Fósseis , Mandíbula/anatomia & histologia
11.
J Colloid Interface Sci ; 633: 628-639, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36481423

RESUMO

Photothermal evaporation using solar energy is a sustainable way to produce fresh water from seawater. Aiming to explore functional materials as a solar-energized evaporator with enhanced evaporation rate and pollutant tolerance, this study was to synthesize a self-floating composite graphene aerogel (GA) doped with Enteromorpha and modified polyethylene glycol (PEG), named as PEGA using solar energy for desalination. Physio-chemical properties and evaporative mechanism of PEGA were experimentally investigated and analyzed with respect to molecular weight, PEG dosage, and ratio of Enteromorpha and graphene oxide. Experimental data revealed that the modification of PEG improved hydrophilic functional ability of PEGA, resulting in increasing the evaporation rate and photothermal conversion efficiency up to 2.55 kg/(m2·h) and 105.71 %, respectively. The ion removal rate of seawater exceeds 99.99 % via the PEGA conducted solar evaporation. Furthermore, PEGA possessed an excellent property of salinity emulsion pollution tolerance. Particularly, the evaporation rate of the PEG-modified biomass-based aerogel was 2.84 kg/(m2·h) in a 15 wt% NaCl solution (1 sun, 6 h) and 2.50 kg/(m2·h) at 1 h. The formation of hydrogen bonds between -OH of PEG and water molecules assist to conduct water along the graphene matrix to improve water evaporation. The cost of the graphene aerogel modified by Enteromorpha was reduced by 38.88 % less than the original graphene aerogel. The results from this study will greatly promote the application of graphene aerogel for desalination via solar evaporation.


Assuntos
Poluentes Ambientais , Grafite , Energia Solar , Biomassa , Polietilenoglicóis
12.
Elife ; 112022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35441592

RESUMO

The dental system of ceratopsids is among the most specialized structure in Dinosauria by the presence of tooth batteries and high-angled wear surfaces. However, the origin of this unique dental system is poorly understood due to a lack of relevant knowledge in early-diverging ceratopsians. Here, we study the dental system of three earliest-diverging Chinese ceratopsians: Yinlong and Hualianceratops from the early Late Jurassic of Xinjiang and Chaoyangsaurus from the Late Jurassic of Liaoning Province. By micro-computed tomographic analyses, our study has revealed significant new information regarding the dental system, including no more than five replacement teeth in each jaw quadrant; at most one replacement tooth in each alveolus; nearly full resorption of the functional tooth root; and occlusion with low-angled, concave wear facets. Yinlong displays an increase in the number of maxillary alveoli and a decrease in the number of replacement teeth during ontogeny as well as the retention of functional tooth remnants in the largest individual. Chaoyangsaurus and Hualianceratops have slightly more replacement teeth than Yinlong. In general, early-diverging ceratopsians display a relatively slow tooth replacement rate and likely use gastroliths to triturate foodstuffs. The difference in dietary strategy might have influenced the tooth replacement pattern in later-diverging ceratopsians.


Assuntos
Dinossauros , Dente , Animais , Dieta , Dinossauros/anatomia & histologia , Fósseis , Odontogênese , Dente/diagnóstico por imagem
13.
Nat Commun ; 12(1): 3890, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162868

RESUMO

The transformation of the bird skull from an ancestral akinetic, heavy, and toothed dinosaurian morphology to a highly derived, lightweight, edentulous, and kinetic skull is an innovation as significant as powered flight and feathers. Our understanding of evolutionary assembly of the modern form and function of avian cranium has been impeded by the rarity of early bird fossils with well-preserved skulls. Here, we describe a new enantiornithine bird from the Early Cretaceous of China that preserves a nearly complete skull including the palatal elements, exposing the components of cranial kinesis. Our three-dimensional reconstruction of the entire enantiornithine skull demonstrates that this bird has an akinetic skull indicated by the unexpected retention of the plesiomorphic dinosaurian palate and diapsid temporal configurations, capped with a derived avialan rostrum and cranial roof, highlighting the highly modular and mosaic evolution of the avialan skull.


Assuntos
Evolução Biológica , Aves/anatomia & histologia , Dinossauros/anatomia & histologia , Fósseis , Crânio/anatomia & histologia , Animais , Osso e Ossos/anatomia & histologia , China , Plumas/anatomia & histologia
14.
Nanoscale ; 13(9): 4774-4784, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33576757

RESUMO

GNA002, a novel EZH2 inhibitor, exhibits significant anticancer efficiency in solid malignant tumor therapy; however, its poor water solubility and low enrichment at tumor sites limit its clinical application and translation. In this study, an original pH-sensitive nanocarrier (cyclo (RGDyCSH) (cRGD)-poly (ethylene glycol) (PEG)-hydrazine (Hyd)-hexa-arginine (R6)-stearic acid (SA)) was designed to precisely deliver GNA002 into the nuclei of cancer cells. The PEG-modified hydrophilic shell of the spherical GNA002-loaded nanoparticles with a mean size of 143.13 ± 0.20 nm effectively facilitated the passive target of tumor tissues and prolonged the blood circulation time. Meanwhile, cRGD was used as the active targeting ligand, which promoted the accumulation of the nanoparticles in cancer cells via ανß3-receptor-mediated endocytosis. Furthermore, the acidic environment of lysosomes triggered the rupture of the pH-sensitive hydrazine bond and the rapid formation of penetrating peptide R6-shelled secondary nanoparticles, thus enabling the lysosomal escape of the nanoparticles and the ultimate R6-mediated nuclear-targeted delivery of GNA002. Consequently, the nuclear-enriched GNA002 effectively enhanced the cytotoxicity against cancer cells both in vitro and in vivo, thus providing an original and promising drug delivery system for the targeted delivery of GNA002.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas , Linhagem Celular Tumoral , Doxorrubicina , Concentração de Íons de Hidrogênio , Peptídeos , Polietilenoglicóis
15.
Environ Sci Pollut Res Int ; 28(26): 34584-34597, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33651293

RESUMO

Preferential removal of phosphate from aqueous was conducted by a novel biomass-based nanocomposite (EP-N+-Zr) with encapsulated hydrous zirconium oxide, and the biopolymer EP-N+-Zr features were described. EP-N+-Zr exhibited high selective sequestration toward phosphate when humic acid or other competing anions (Cl-, SO42-, NO3-, ClO4-) coexisted at relatively high levels. Such excellent performance of EP-N+-Zr was attributed to its specific two site structures; the embedded HZO nanoparticles and quaternary ammonia groups [N+(CH2CH3)3Cl-] bonded inside the biomass-Enteromorpha prolifera, which facilitated preferable capture towards phosphate through specific affinity and nonspecific preconcentration of phosphate ions on the basis of the ion exchange, respectively. The maximum adsorption capacity of phosphate (20 °C) as calculated by Langmuir model was 88.5 mg(P)/g. Regeneration tests showed that EP-N+-Zr could be recycled at least five times without noticeable capacity losses using binary NaOH-NaCl as eluent.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Adsorção , Biopolímeros , Concentração de Íons de Hidrogênio , Cinética , Fosfatos , Poluentes Químicos da Água/análise , Zircônio
16.
Nature ; 430(7003): 1021-4, 2004 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-15329719

RESUMO

The skull of living crocodylians is highly solidified and the jaw closing muscles are enlarged, allowing for prey capture by prolonged crushing between the jaws. Living species are all semi-aquatic, with sprawling limbs and a broad body that moves mainly from side-to-side; however, fossils indicate that they evolved from terrestrial forms. The most cursorial of these fossils are small, gracile forms often grouped together as the Sphenosuchia, with fully erect, slender limbs; their relationships, however, are poorly understood. A new crocodylomorph from deposits in northwestern China of the poorly known Middle Jurassic epoch possesses a skull with several adaptations typical of living crocodylians. Postcranially it is similar to sphenosuchians but with even greater adaptations for cursoriality in the forelimb. Here we show, through phylogenetic analysis, that it is the closest relative of the large group Crocodyliformes, including living crocodylians. Thus, important features of the modern crocodylian skull evolved during a phase when the postcranial skeleton was evolving towards greater cursoriality, rather than towards their current semi-aquatic habitus.


Assuntos
Jacarés e Crocodilos/anatomia & histologia , Evolução Biológica , Fósseis , Crânio/anatomia & histologia , Jacarés e Crocodilos/classificação , Jacarés e Crocodilos/fisiologia , Animais , China , Arcada Osseodentária/anatomia & histologia , Filogenia , Fatores de Tempo
17.
Cell Death Discov ; 6: 47, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32566254

RESUMO

Long-term administration of nitrogen-containing bisphosphonates increases the risk of detrimental side effects, such as bisphosphonate-related osteonecrosis of the jaw (BRONJ). BRONJ development is associated with inflammation, but its pathophysiology remains unknown. Here, we examined whether histone methylation is responsible for zoledronic acid (Zol)-induced inflammatory responses. We found that Kdm6a and Kdm6b markedly increased interleukin 1ß expression and Gasdermin D cleavage, which are both activated by Caspase 1, in macrophages. Inhibitors of Kdm6a and Kdm6b robustly abolished Zol-enhanced interleukin 1ß synthesis and secretion from macrophages. When Kdm6a and Kdm6b were pharmacologically inhibited in vivo, poor healing of the alveolar socket and inflammatory responses were ameliorated in Zol-treated mice. Taken together, we showed the pathologic role of Kdm6a and Kdm6b in Zol-promoted inflammatory responses and demonstrated that Kdm6a and Kdm6b are potential therapeutic targets for the treatment of BRONJ.

18.
Naturwissenschaften ; 96(9): 1051-8, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19488730

RESUMO

Little is known about the evolution of large-bodied theropod dinosaurs during the Early to mid Cretaceous in Asia. Prior to this time, Asia was home to an endemic fauna of basal tetanurans, whereas terminal Cretaceous ecosystems were dominated by tyrannosaurids, but the intervening 60 million years left a sparse fossil record. Here, we redescribe the enigmatic large-bodied Chilantaisaurus maortuensis from the Turonian of Inner Mongolia, China. We refer this species to a new genus, Shaochilong, and analyze its systematic affinities. Although Shaochilong has previously been allied with several disparate theropod groups (Megalosauridae, Allosauridae, Tyrannosauroidea, Maniraptora), we find strong support for a derived carcharodontosaurid placement. As such, Shaochilong is the first unequivocal Asian member of Carcharodontosauridae, which was once thought to be restricted to Gondwana. The discovery of an Asian carcharodontosaurid indicates that this clade was cosmopolitan in the Early to mid Cretaceous and that Asian large-bodied theropod faunas were no longer endemic at this time. It may also suggest that the ascent of tyrannosaurids into the large-bodied dinosaurian predator niche was a late event that occurred towards the end of the Cretaceous, between the Turonian and the Campanian.


Assuntos
Dinossauros/anatomia & histologia , Animais , Ásia , Evolução Biológica , Dinossauros/classificação , Forame Magno/anatomia & histologia , Fósseis , Osso Frontal/anatomia & histologia , Maxila/anatomia & histologia , Osso Nasal/anatomia & histologia , Paleontologia , Filogenia , Coluna Vertebral/anatomia & histologia , Tempo
19.
Sci Rep ; 9(1): 5026, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30903000

RESUMO

Therizinosaurian theropods evolved many highly specialized osteological features in association with their bulky proportions, which were unusual in the context of the generally gracile Theropoda. Here we report a new therizinosaur, Lingyuanosaurus sihedangensis gen. et sp. nov., based on a specimen recovered from the Lower Cretaceous Jehol Group of Lingyuan, Liaoning Province, China, which displays a combination of plesiomorphic and derived features. Most notably, the specimen is characterized by posterior dorsal vertebrae with a complex and unusual laminar structure; an ilium with a highly dorsoventrally expanded preacetabular process showing only slight lateral flaring of the ventral margin, a strongly anterodorsally inclined iliac blade, a small postacetabular process with a strongly concave dorsal margin, and a relatively robust pubic peduncle with a posteroventrally facing distal articular surface; a straight and robust femur with a small lesser trochanter; and a tibia that is longer than the femur. Phylogenetic analysis places Lingyuanosaurus in an intermediate position within Therizinosauria, i.e., between the early-branching therizinosaurs such as Falcarius, Jianchangosaurus, and Beipiaosaurus and the late-branching ones such as Alxasaurus and Therizinosaurus. This new therizinosaur sheds additional light on the evolution of major therizinosaurian characteristics, including particularly the distinctive pelvic girdle and hindlimb morphology seen in this group.


Assuntos
Dinossauros/anatomia & histologia , Fósseis , Membro Posterior/anatomia & histologia , Coluna Vertebral/anatomia & histologia , Dente/anatomia & histologia , Animais , Evolução Biológica , Biota , China , Dinossauros/classificação , Dinossauros/genética , Fêmur/anatomia & histologia , Filogenia , Tíbia/anatomia & histologia
20.
Chemosphere ; 215: 214-226, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30317092

RESUMO

In this work, four alkaline lignin (AL) based flocculants with distinct molecular weight, chain architectures and charge densities (denoted as AL-g-DMC1, AL-g-DMC2, AL-GTA1 and AL-GTA2) were prepared from paper mill sludge, which were designed via graft copolymerization of dimethyl diallyl ammonium chloride (DMC) or etherification of 2, 3-epoxypropyl trimethyl ammonium chloride (GTA). The characteristics of the aforementioned flocculants were evaluated by a series of analysis technologies, which essentially confirmed the successful introduction of quaternary ammonium groups onto the AL. The flocculation performances of the four synthesized lignin-based polymers as the coagulant aids for PAC were investigated in disperse dye (DY) wastewater treatment, and the effects of dosages, initial pH, coexisting ions, humic acid (HA) or kaolin particles were also studied. The results indicated that branched copolymers with high molecular weight like AL-g-DMC1 and AL-g-DMC2 exerted excellent color removals and satisfactory floc properties in comparison with linear polymers with low molecular weight (AL-GTA1 and AL-GTA2). Furthermore, AL-g-DMC1 and AL-g-DMC2 exhibited remarkable tolerance on pH alteration and coexisting ions owing to their strong bridging action.


Assuntos
Águas Residuárias/química , Purificação da Água/métodos , Corantes/isolamento & purificação , Floculação , Lignina/química , Peso Molecular , Polímeros/química , Esgotos/química , Poluentes Químicos da Água/isolamento & purificação
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