Skeleton of a Cretaceous mammal from Madagascar reflects long-term insularity.

The fossil record of mammaliaforms (mammals and their closest relatives) of the Mesozoic era from the southern supercontinent Gondwana is far less extensive than that from its northern counterpart, Laurasia1,2. Among Mesozoic mammaliaforms, Gondwanatheria is one of the most poorly known clades, previously represented by only a single cranium and isolated jaws and teeth1-5. As a result, the anatomy, palaeobiology and phylogenetic relationships of gondwanatherians remain unclear. Here we report the discovery of an articulated and very well-preserved skeleton of a gondwanatherian of the latest age (72.1-66 million years ago) of the Cretaceous period from Madagascar that we assign to a new genus and species, Adalatherium hui. To our knowledge, the specimen is the most complete skeleton of a Gondwanan Mesozoic mammaliaform that has been found, and includes the only postcranial material and ascending ramus of the dentary known for any gondwanatherian. A phylogenetic analysis including the new taxon recovers Gondwanatheria as the sister group to Multituberculata. The skeleton, which represents one of the largest of the Gondwanan Mesozoic mammaliaforms, is particularly notable for exhibiting many unique features in combination with features that are convergent on those of therian mammals. This uniqueness is consistent with a lineage history for A. hui of isolation on Madagascar for more than 20 million years.

Fast determination of aristolochic acid I (AAI) in traditional Chinese medicine soup with magnetic solid-phase extraction by high performance liquid chromatography.

In this paper, a novel core-shell structure magnetic microsphere Fe3O4@SiO2-TPM@StVp(Fe3O4@SiO2-3-(trimethoxysilyl)propyl methacrylate@styrene and n-vinylpyrrolidone) was successfully synthesized and used as a magnetic solid-phase extraction adsorbent for extraction of aristolochic acid I (AAI) in traditional Chinese medicine soup. The prepared Fe3O4@SiO2-TPM@StVp was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and Fourier-transform infrared spectroscopy (FT-IR). The microspheres have various advantages of excellent hydrophilicity and π-electron system, which is very suitable for determining target analytes followed by high performance liquid chromatography (HPLC). The main factors, including the pH of samples, amount of adsorbent, adsorption time, elution solvent and desorption time, were optimized. Under optimal conditions, the proposed method showed a wide linear range of 0.4-10 µg/mL and a good correlation coefficient (R2 = 0.9918). The pretreatment procedure was achieved within 10 min. The recoveries of aristolochic acid I in real samples range from 80.9% to 89.6% with relative standard deviations less than 4.9%, highlighting the accuracy of this method.

Integrated hearing and chewing modules decoupled in a Cretaceous stem therian mammal.

On the basis of multiple skeletal specimens from Liaoning, China, we report a new genus and species of Cretaceous stem therian mammal that displays decoupling of hearing and chewing apparatuses and functions. The auditory bones, including the surangular, have no bone contact with the ossified Meckel's cartilage; the latter is loosely lodged on the medial rear of the dentary. This configuration probably represents the initial morphological stage of the definitive mammalian middle ear. Evidence shows that hearing and chewing apparatuses have evolved in a modular fashion. Starting as an integrated complex in non-mammaliaform cynodonts, the two modules, regulated by similar developmental and genetic mechanisms, eventually decoupled during the evolution of mammals, allowing further improvement for more efficient hearing and mastication.

The synthesis of Zr-metal-organic framework functionalized magnetic graphene nanocomposites as an adsorbent for fast determination of multi-pesticide residues in tobacco samples.

In this paper, a simple and reliable method has been established to determine the residues of nine pesticides in tobacco by using GC-MS coupled with magnetic solid phase extraction. A novel magnetic Zr-MOF nanocomposite based on graphene was synthesized, and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy and N2 adsorption-desorption measurements. The prepared material has the advantage of large surface area (178 m2/g), good magnetic response and high thermal stability, which is shown to be suited for the fast enrichment of multi-pesticides in tobacco matrix. The extraction conditions including amount of adsorbent, adsorption time, eluting solvent as well as desorption time were investigated. The whole process of pretreatment is accomplished within 10 min. This method shows low limit of detection, wide linear range and good reproducibility (relative standard deviations <12.7%), satisfactory recoveries were obtained, ranging from 57.9% to 126.3% for tobacco samples.

Synthesis of polydopamine-functionalized magnetic graphene and carbon nanotubes hybrid nanocomposites as an adsorbent for the fast determination of 16 priority polycyclic aromatic hydrocarbons in aqueous samples.

A novel adsorbent made of polydopamine-functionalized magnetic graphene and carbon nanotubes hybrid nanocomposite was synthesized and applied to determine 16 priority polycyclic aromatic hydrocarbons by magnetic solid phase extraction in water samples. FTIR spectroscopy, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy consistently indicate that the synthesized adsorbents are made of core-shell nanoparticles well dispersed on the surface of graphene and carbon nanotubes. The major factors affecting the extraction efficiency, including the pH value of samples, the amount of adsorbent, adsorption time and desorption time, type and volume of desorption solvent, were systematically optimized. Under the optimum extraction conditions, a linear response was obtained for polycyclic aromatic hydrocarbons between concentrations of 10 and 500 ng/L with the correlation coefficients ranging from 0.9958 to 0.9989, and the limits of detection (S/N = 3) were between 0.1 and 3.0 ng/L. Satisfactory results were also obtained when applying these magnetic graphene/carbon nanotubes/polydopamine hybrid nanocomposites to detect polycyclic aromatic hydrocarbons in several environmental aqueous samples.

Magnetic solid-phase extraction of phthalate esters (PAEs) in apparel textile by core-shell structured Fe3O4@silica@triblock-copolymer magnetic microspheres.

In this paper, novel core-shell structured magnetic Fe3O4/silica nanocomposites with triblock-copolymer grafted on their surface (Fe3O4@SiO2@MDN) were successfully fabricated by combining a sol-gel method with a seeded aqueous-phase radical copolymerization approach. Owing to the excellent characteristics of the strong magnetic responsivity, outstanding hydrophilicity and abundant π-electron system, the obtained core-shell structured microspheres showed great potential as a magnetic solid phase extraction (MSPE) adsorbent. Several kinds of phthalate esters (PAEs) were selected as model analytes to systematically evaluate the applicability of adsorbents for extraction followed by gas chromatography-mass spectrometry (GC-MS) analyses. Various parameters, including adsorbents amounts, adsorption time, species of eluent, and desorption time were optimized. Under the optimized conditions, Validation experiments such as recovery, reproducibility, and limit of detection were carried on and showed satisfactory results. The analysis method showed excellent linearity with a wide range of 0.2-10mg/kg (R(2)>0.9974) and low limits of detection (LOD) of 0.02-0.09 mg/kg (S/N=3). Ultimately, the novel magnetic adsorbents were successfully employed to detect the PAEs in apparel textile samples. And the results indicated that this novel approach brought forward in the present work offered an attractive alternative for rapid, efficient and sensitive MSPE for PAEs compounds.

Development of alpha-lipoic acid encapsulated chitosan monodispersed particles using an electrospray system: synthesis, characterisations and anti-inflammatory evaluations.

This study demonstrates the feasibility of using a single-capillary electrospray (ES) system to generate novel alpha-lipoic acid encapsulated poly(ethylene oxide)-chitosan (ALA/PEO/CS) particles with a monodispersed diameter. Scanning electron microscopic images (SEM) and dynamic light scattering (DLS) results indicate that the ES system can generate either a dry powder or a homogeneous water-based suspension of ALA/PEO/CS particles. The SEM images revealed that the ALA/PEO/CS particles have a spherical shape with a diameter of approximately 707 ± 66.68 nm, and DLS showed that the ALA/PEO/CS particles suspended in deionised water have a diameter of 734.5 nm. In addition, zeta potential studies were performed using a zetasizer instrument and showed positively electric surface potential of 57.7 ± 0.5 mV, which was attributed to chitosan. Based on the DLS and zeta potential studies, we concluded that the excellent dispersity and stability of the ALA/PEO/CS suspension is attributed to the reduction in particle size and electrostatic repulsion between these tiny particles. Finally, we used lipopolysaccharide (LPS)-induced nitrite formation in Raw 264.7 macrophages as a model for in vitro anti-inflammation evaluation. We find that the anti-inflammatory ability of the ALA/PEO/CS particles is superior to that of free ALA solution in macrophage cells, which is attributed to the more efficiently intracellular delivery. The confocal image results prove that the uptake of ALA/PEO/CS particles by the LPS-treated Raw 264.7 macrophages is possibly initiated by the interaction with cell-surface molecules through electrostatic interactions, followed by endocytosis of the attached particles.

Determination of lomerizine in human plasma by liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study.

A rapid, sensitive and selective high performance liquid chromatography-electrospray ionization-tandem mass spectrometry method (HPLC-ESI-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of lomerizine in human plasma. Protein precipitation process was used to extract lomerizine from human plasma. Plasma samples were separated by HPLC on an Agela Venusil XBP Phenyl column (100 mm × 2.1 mm, 5 µm) using a mobile phase consisting of methanol-2mM ammonium acetate-formic acid (70:30:0.1, v/v/v) and the flow rate was set at 0.35 mL/min. The total run time was 4.0 min and the elution of lomerizine was at 1.9 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective [M+H](+) ions m/z 469.2→181.0 for lomerizine and m/z 405.2→202.9 for the I.S. The calibration curve was linear over the range of 0.1-25 ng/mL (r(2)>0.99) with a limit of quantitation (LOQ) of 0.1 ng/mL. The intra- and inter-day precision (relative standard deviation, RSD) values were below 9.65% and the mean accuracy was from 99.00 to 103.00% at four quality control levels. Lomerizine was stable during stability studies, i.e., long term, auto-sampler and freeze/thaw cycles. The method was successfully applied for the evaluation of pharmacokinetics of lomerizine after single oral doses of 10 mg lomerizine to 18 healthy volunteers.

Determination of organic pollutants in coking wastewater by dispersive liquid-liquid microextraction/GC/MS.

A method based on dispersive liquid-liquid microextraction coupled with GC/MS was developed for quantitative analysis of the major organic pollutants listed in the United States Environmental Protection Agency method 8270 and the 15 European-priority polycyclic aromatic hydrocarbons in coking wastewater. The major parameters such as extraction solvent, dispersive solvent, solution pH, and extraction time were systematically optimized. The optimum extraction conditions were found to be: 15 µL mixture of 2:1 v/v carbon tetrachloride and chlorobenzene as the extraction solvent, 0.75 mL ACN as the dispersive solvent, solution pH of 8, and extraction time of 2 min. For the major pollutants listed in the United States Environmental Protection Agency 8270, the linear ranges were 0.1 to 100 mg/L, the enrichment factors ranged from 452 to 685, and the relative recoveries ranged from 67.5 to 103.5% with RSDs of 4.0-9.1% (n = 5) at the concentrations of 10 mg/L under the optimum extraction conditions. For the 15 polycyclic aromatic hydrocarbons, the linear ranges were 0.1 to 100 µg/L, the enrichment factors ranged from 645 to 723, and the relative recoveries ranged from 94.5 to 107.6% with RSDs of 4.6-9.0% (n = 5) at the concentrations of 10 µg/L. The usefulness of the developed method was demonstrated by applying it in the analysis of real-world coking wastewater samples.

Identification and functional analysis of variant haplotypes in the 5'-flanking region of protein phosphatase 2A-Bδ gene.

Serine-threonine protein phosphatase 2A (PP2A) is a trimeric holoenzyme that plays an integral role in the regulation of cell growth, differentiation, and apoptosis. The substrate specificity and (sub)cellular localization of the PP2A holoenzymes are highly regulated by interaction with a family of regulatory B subunits (PP2A-Bs). The regulatory subunit PP2A-B/PR55δ (PP2A-Bδ) is involving in the dephosphorylation of PP2A substrates and is crucial for controlling entry into and exit from mitosis. The molecular mechanisms involved in the regulation of expression of PP2A-Bδ gene (PPP2R2D) remain largely unknown. To explore genetic variations in the 5'-flanking region of PPP2R2D gene as well as their frequent haplotypes in the Han Chinese population and determine whether such variations have an impact on transcriptional activity, DNA samples were collected from 70 healthy Chinese donors and sequenced for identifying genetic variants in the 5'-flanking region of PPP2R2D. Four genetic variants were identified in the 1836 bp 5'-flanking region of PPP2R2D. Linkage disequilibrium (LD) patterns and haplotype profiles were constructed for the genetic variants. Using serially truncated human PPP2R2D promoter luciferase constructs, we found that a 601 bp (-540 nt to +61 nt) fragment constitutes the core promoter region. The subcloning of individual 5'-flanking fragment revealed the existence of three haplotypes in the distal promoter of PPP2R2D. The luciferase reporter assay showed that different haplotypes exhibited distinct promoter activities. The EMSA revealed that the -462 G>A variant influences DNA-protein interactions involving the nuclear factor 1 (NF1). In vitro reporter gene assay indicated that cotransfection of NF1/B expression plasmid could positively regulate the activity of PPP2R2D proximal promoter. Introduction of exogenous NF1/B expression plasmid further confirmed that the NF1 involves in the regulation of PPP2R2D gene expression. Our findings suggest that functional genetic variants and their haplotypes in the 5'-flanking region of PPP2R2D are critical for transcriptional regulation of PP2A-Bδ.

Derivatization followed by gas chromatography-mass spectrometry for quantification of ethyl carbamate in alcoholic beverages.

A sensitive and rapid analytical methodology based on derivatization followed by gas chromatography-mass spectrometry (GC-MS) was developed for the quantitative determination of the toxic contaminant ethyl carbamate (EC, urethane, C(2)H(5)OCONH(2)) in alcoholic samples. EC was extracted using liquid-liquid extraction technique, and then silylated with bis-(trimethylsilyl)trifluoroacetamide, analysed finally by GC-MS. The isopropyl carbamate was used as the internal standard for quantitative analysis of EC in alcoholic samples. In this work, the sample extraction and derivatization reaction conditions were investigated, and the optimal extraction conditions obtained were: pH 9 and solvent of ethyl acetate, and the derivatization conditions were: derivatization reaction temperature of 80°C and time duration of 30 min. With the optimal conditions, the method validations were also studied. In the validation studies, EC exhibited good linearity with a regression coefficient of 0.9999. The limit of detection and limit of quantification were 0.30 and 5.0 µg/kg, respectively. The precision was less than 8.4%. Finally, the proposed technique was successfully applied to the analysis of EC in 35 kinds of alcoholic samples. The experimental results have demonstrated that the proposed technique is a fast, reliable and low-cost method for determination of EC in alcoholic samples.

Identification and functional analyses of polymorphism haplotypes of protein phosphatase 2A-Aα gene promoter.

The serine-threonine protein phosphatase 2A (PP2A) is a heterotrimeric enzyme family that plays an essential regulatory role in cell growth, differentiation, and apoptosis. Mutations in the genes encoding PP2A-Aα/ß subunits are associated with tumorigenesis and other human diseases. To explore whether genetic variations in the promoter region of the PP2A-Aα gene (PPP2R1A) and their frequent haplotypes in the Han Chinese population have an impact on transcriptional activity, we collected DNA samples from 63 healthy Chinese donors and searched for genetic variations in the 5'-flanking promoter region of PPP2R1A (PPP2R1Ap). Haplotypes were characterized by Haploview analysis and individual subcloning. A set of molecular and functional experiments was performed using reporter genes and electrophoretic mobility shifting assay (EMSA). Seven genetic variations were identified within the promoter locus (2038bp) of PPP2R1A. Linkage disequilibrium (LD) patterns and haplotype profiles were analyzed using the identified genetic variants. Using serially truncated human PPP2R1A promoter luciferase constructs, we found that a 685bp (-448nt to +237nt) fragment around the transcription start site (TSS) was the core promoter region. Individual subcloning revealed the existence of six haplotypes in this proximal promoter region of PPP2R1Ap. Using luciferase reporter assays, we found that different haplotypes bearing different variant alleles exhibit distinct promoter activities. The EMSA revealed that the -241 -/G variant influences DNA-protein interactions involving the transcription factor NF-κB, which may regulate the activity of the PPP2R1A proximal promoter. Our findings suggest that functional genetic variants in the proximal promoter of the PP2A-Aα gene and their haplotypes are critical in the regulation of transcriptional activation.

New basal eutherian mammal from the Early Cretaceous Jehol biota, Liaoning, China.

A new genus and species of eutherian mammal, Acristatherium yanensis gen. et sp. nov., is described from the Early Cretaceous Jehol biota, China. The new taxon is based on a partial skull that is preserved in three dimensions from the Lujiatun bed of the Yixian Formation and dated 123.2+/-1.0 Ma. Its right upper and lower dentitions are nearly complete and it has a dental formula 4.1.5.3/3.1.5.3. The new mammal reveals several craniodental characteristics of Early Cretaceous eutherians previously unknown in fossil records of therians, such as a possible vestige of the septomaxilla. The craniodental features of the new taxon are compared with those of relevant Early Cretaceous eutherians and therians. Phylogenetic analyses based on a data matrix containing 70 taxa and 408 characters place A. yanensis as the most basal eutherian in the selected group. The morphological differences between Acristatherium and Eomaia indicate that eutherians already had a significant degree of generic diversification ca 125 Ma.

A Mesozoic gliding mammal from northeastern China.

Gliding flight has independently evolved many times in vertebrates. Direct evidence of gliding is rare in fossil records and is unknown in mammals from the Mesozoic era. Here we report a new Mesozoic mammal from Inner Mongolia, China, that represents a previously unknown group characterized by a highly specialized insectivorous dentition and a sizable patagium (flying membrane) for gliding flight. The patagium is covered with dense hair and supported by an elongated tail and limbs; the latter also bear many features adapted for arboreal life. This discovery extends the earliest record of gliding flight for mammals to at least 70 million years earlier in geological history, and demonstrates that early mammals were diverse in their locomotor strategies and lifestyles; they had experimented with an aerial habit at about the same time as, if not earlier than, when birds endeavoured to exploit the sky.

Large Mesozoic mammals fed on young dinosaurs.

Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China. An adult individual of R. robustus was the size of a Virginia opossum. Here we report a new species of the genus, represented by a skeleton with most of the skull and postcranium preserved in articulation. The new species is 50% larger than R. robustus in skull length. In addition, stomach contents associated with a skeleton of R. robustus reveal remains of a juvenile Psittacosaurus, a ceratopsian dinosaur. Our discoveries constitute the first direct evidence that some triconodont mammals were carnivorous and fed on small vertebrates, including young dinosaurs, and also show that Mesozoic mammals had a much greater range of body sizes than previously known. We suggest that Mesozoic mammals occupied diverse niches and that some large mammals probably competed with dinosaurs for food and territory.

Rapid determination of volatile compounds emitted from Chimonanthus praecox flowers by HS-SPME-GC-MS.

A novel rapid, simple and solvent-free method was developed for determination of the volatile compounds from the flowers of Chimonanthus praecox Link using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The SPME conditions were firstly optimized and applied to sampling of the volatile compounds emitted from living Chimonanthus praecox L. flowers and excised Chimonanthus praecox L. flowers. Thirty-one compounds emitted from living flowers were identified for the first time, which mainly included 4-methyl-1,3-pentadiene (2.0%), a-phellandrene (4.7%), benzyl methanol (11.1%), trans-linalool oxide (furanyl ring) (5.3%), a-linalool (36.0%), methyl salicylate (24.5%) and acetic acid benzyl ester (5.9%). Comparing the emission from living flowers and excised flowers, twenty-eight compounds were found to be detected in the two emissions, and three compounds, n-pentadecane, n-cetane and n-heptadecane, were only found in the emission from the living flowers, which shows that they might be biomarker compounds.

Chemical composition of the essential oils of two Alpinia species from Hainan Island, China.

The essential oils of two Alpinia species, ie. A. hainanensis and A. katsumadai, from Hainan Island, China were analyzed by using GC-MS. The major constituents in the leaf oil of A. hainanensis were ocimene (27.4%), beta-pinene (10.1%), 9-octadecenoic acid (6.5%), n-hexadecanoic acid (5.8%), 9,12-octadecadienoic acid (5.4%), and terpinen (4.3%). The oil constituents obtained from the flowers of A. hainanensis were ocimene (39.8%), beta-pinene (17.7%), terpinene (5.5%), p-menth-1-en-ol (4.9%), caryophyllene (4.9%), and phellandrene (4.4%). In A. katsumadai, the major constituents in the leaf oil were p-menth-1-en-ol (22.0%), terpinen (19.0%), 4-carene (9.1%), 1,8-cineole (8.3%), and camphor (5.6%). The major constituents in the flower oil were p-menth-1-en-ol (21.3%), 1,8-cineole (20.2%), terpinen (12.6%), phellandrene (7.0%), 4-carene (6.4%), and beta-pinene (5.2%).

A euprimate skull from the early Eocene of China.

The debut of undoubted euprimates (primates of modern aspect) was in the early Eocene, about 55 Myr ago. Since their first appearance, the earliest euprimates can be distinguished as Cantius, Donrussellia and Teilhardina. Nonetheless, the earliest euprimates are primarily known from isolated teeth or fragmentary jaws. Here we describe a partially preserved euprimate skull with nearly complete upper and lower dentition, which represents a new species of Teilhardina and constitutes the first discovery of the genus in Asia. The new species is from the upper section of Lingcha Formation, Hunan Province, China, with an estimated age of 54.97 Myr ago. Morphology and phylogeny analyses reveal that the new species is the most primitive species of Teilhardina, positioned near the root of euprimate radiation. This discovery of the earliest euprimate skull known to date casts new light on the debate concerning the adaptive origin of euprimates, and suggests that the last common ancestor of euprimates was probably a small, diurnal, visually oriented predator.

Application of HS-SPME and GC-MS to characterization of volatile compounds emitted from Osmanthus flowers.

Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was developed for characterization of volatile compounds emitted from two varieties Osmanthus flowers of O. fragrans var. latifolius and O. fragrans var. thunbergii. The SPME parameters were studied, the optimum conditions of a 65 microm carbowax/divinylbenzene (CW/DVB), extraction temperature of 22 degrees C and extraction time of 10 min were obtained and applied to extraction of the volatile emissions. Fourteen compounds released from both varieties of Osmanthus flowers were separated and identified by GC-MS, which mainly included alpha-linalool, beta-linalool, trans-linalool oxide, cis-linalool oxide, alpha-lonone, beta-lonone, capraldehyde and decalactone. By comparing their peak areas, we found that the sums of the fourteen compounds from the two Osmanthus flowers were very close, while the relative contents of individual volatile compounds in the two emissions were very different. The relative content of alpha-linalool and beta-linalool in O. fragrans var. latifolius were 39.46% and 0.51%, while in O. fragrans var. thunbergii were 9.53% and 27.71%. Due to their different relative contents, the two varieties of flower have different fragrances.

Rapid diagnosis of phenylketonuria and other aminoacidemias by quantitative analysis of amino acids in neonatal blood spots by gas chromatography-mass spectrometry.

A new method for quantifying specific amino acids in small volumes of plasma and whole blood has been developed. Volatile derivatives of amino acids are analyzed by gas chromatography-mass spectrometry. The method only takes a few minutes to perform and requires minimal sample preparation. The accurate assay of phenylalanine, tyrosine and other amino acids in dried blood spots could be used for neonatal screening for phenylketonuria and other aminoacidemias. Because of the low cost, this neonatal screening method is suited to application in developing countries such as China.