Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.
To study the Chinese ancient five-element theory, one of the philosophical foundations of Traditional Chinese Medicine (TCM) theory construction, from the perspective of comtemporary cognitive science, and to reveal the important functions of five-element theory in the construction of TCM theory.
To investigate the guidance role of preoperative nutritional risk screening in perioperative nutrition support for colorectal cancer patients in order to provide evidence for the rational clinical application of nutrition support.
DNA origami represents a class of highly programmable macromolecules that can go through conformational changes in response to external signals. Here we show that a two-dimensional origami rectangle can be effectively folded into a short, cylindrical tube by connecting the two opposite edges through the hybridization of linker strands and that this process can be efficiently reversed via toehold-mediated strand displacement. The reconfiguration kinetics was experimentally studied as a function of incubation temperature, initial origami concentration, missing staples, and origami geometry. A kinetic model was developed by introducing the j factor to describe the reaction rates in the cyclization process. We found that the cyclization efficiency (j factor) increases sharply with temperature and depends strongly on the structural flexibility and geometry. A simple mechanical model was used to correlate the observed cyclization efficiency with origami structure details. The mechanical analysis suggests two sources of the energy barrier for DNA origami folding: overcoming global twisting and bending the structure into a circular conformation. It also provides the first semiquantitative estimation of the rigidity of DNA interhelix crossovers, an essential element in structural DNA nanotechnology. This work demonstrates efficient DNA origami reconfiguration, advances our understanding of the dynamics and mechanical properties of self-assembled DNA structures, and should be valuable to the field of DNA nanotechnology.
Dysregulated microRNAs (miRNAs) have been reported to be associated with pancreatic cancer (PaC), suggesting that they may serve as useful novel diagnostic biomarkers for PaC. Various studies have been performed to investigate the diagnostic value of miRNAs for PaC but have obtained conflicting results. Therefore, this meta-analysis aims to comprehensively and quantitatively evaluate the potential diagnostic value of miRNAs for PaC. We systematically searched PubMed, Embase, Google Scholar, Cochrane Library, and Chinese National Knowledge Infrastructure for publications concerning the diagnostic value of miRNAs for PaC without language restriction. The quality of each study was scored using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The summary receiver operator characteristic curve and other parameters were applied to check the overall test performance. Heterogeneity was tested with the I (2) test and publication bias was tested with the Deek's funnel plot asymmetry test. This meta-analysis included 18 articles with a total of 2,036 patients and 1,444 controls. The pooled sensitivity was 82 % (95 % CI, 78-86 %); the specificity was 77 % (95 % CI, 73-81 %); the PLR was 3.6 (95 % CI, 3.0-4.4); the NLR was 0.23 (95 % CI, 0.18-0.29); the DOR was 16 (95 % CI, 10-24); and the AUC was 0.86 (95 % CI, 0.83-0.89). Subgroups analyses were also performed and revealed that there were significant differences between some subgroups: the multiple-miRNAs profiling-based assays, non-blood-based assays, and healthy control-based studies all showed higher accuracies in diagnosing PaC than that of their counterparts. This meta-analysis suggests that the use of miRNAs has potential diagnostic value with a relatively high sensitivity and specificity for PaC, particularly the use of multiple miRNAs for discriminating PaC patients from healthy individuals. More prospective studies on the diagnostic value of miRNAs for PaC are needed in the future.
The dynamic reconfiguration of a hierarchically assembled tubular structure is demonstrated using the DNA origami technique. Short cylindrical DNA origami monomers are synthesized and linked into elongated tubules, which can then be disassembled via toehold-mediated strand displacement. The disassembled subunits are subsequently linked into tubules of a different chirality. The reconfiguration is performed with the subunits carrying dumbbell hairpin DNA oligonucleotides or gold nanoparticles (AuNPs). The reconfiguration of higher order origami structures presented here is useful for constructing dynamic nanostructures that exceed the size limit of single DNA origami and may facilitate the study of molecular or particle interactions by tuning their relative distance and organization.
Maternal behavior in rats is a highly motivated and well-organized social behavior. Given the known roles of serotonin (5-HT) in emotion, motivation, social behavior, and major depression - and its known interaction with dopamine - it is likely that serotonin also plays a crucial role in this behavior. So far, there are surprisingly few studies focusing on 5-HT in maternal behavior, except for maternal aggression. In the present study, we examined the effects of 5-HT2C receptor agonism and 5-HT2A receptor antagonism on maternal behavior in postpartum female rats. We hypothesized that activation of 5-HT2C receptors and blockade of 5-HT2A receptors would produce a functionally equivalent disruption of maternal behavior because these two receptor subtypes often exert opposite effects on various brain functions and psychological processes relevant to rat maternal behavior. On postpartum Days 5, 7, and 9, Sprague-Dawley mother rats were given a single injection of 0.9% NaCl solution, the 5-HT2C agonist MK212 (0.5, 1.0 or 2.0mg/kg, ip), or the 5-HT2A antagonist MDL100907 (0.05, 0.5 or 2.0mg/kg, ip). Maternal behavior was tested 30min before and 30min, 120min, 240min after injection. Acute injection of MK212 significantly disrupted pup retrieval, pup licking, pup nursing, and nest building in a dose-dependent fashion. At the tested doses, MDL100907 had little effect on various components of rat maternal behavior. Across the 3days of testing, no apparent sensitization or tolerance associated with repeated administration of MK212 and MDL100907 was found. We concluded that rat maternal performance is critically dependent on 5-HT2C receptors, while the role of 5-HT2A receptors is still inconclusive. Possible behavioral mechanisms of actions of 5-HT2C receptor in maternal behavior are discussed.
A novel optical platform based on DNA aptamer-functionalized SWCNTs (a-SWCNTs) is developed for multiplexed detection of plasma porphyrins. We have investigated the interactions of a-SWCNTs with heme (FePP), protoporphyrin (PP), coproporphyrin (CP), and uroporphyrin (UP). Two interaction mechanisms, specific binding, and nonspecific adsorption between porphyrins and a-SWCNTs are proposed based on observed optical signal modulations. The optical transduction signals are used to formulate a multiplexed detection strategy for the four porphyrin species without a laborious separation process. The detection scheme is sensitive, selective, and can readily be used for porphyrin detection in plasma samples when combined with a solvent extraction method. Our optical platform offers novel analytical tools for probing the surface chemistry at the porphyrin/a-SWCNTs interface, showing great promise for both research and clinical applications.
Intracellular protein motors have evolved to perform specific tasks critical to the function of cells such as intracellular trafficking and cell division. Kinesin and dynein motors, for example, transport cargoes in living cells by walking along microtubules powered by adenosine triphosphate hydrolysis. These motors can make discrete 8 nm centre-of-mass steps and can travel over 1 µm by changing their conformations during the course of adenosine triphosphate binding, hydrolysis and product release. Inspired by such biological machines, synthetic analogues have been developed including self-assembled DNA walkers that can make stepwise movements on RNA/DNA substrates or can function as programmable assembly lines. Here, we show that motors based on RNA-cleaving DNA enzymes can transport nanoparticle cargoes-CdS nanocrystals in this case-along single-walled carbon nanotubes. Our motors extract chemical energy from RNA molecules decorated on the nanotubes and use that energy to fuel autonomous, processive walking through a series of conformational changes along the one-dimensional track. The walking is controllable and adapts to changes in the local environment, which allows us to remotely direct go and stop actions. The translocation of individual motors can be visualized in real time using the visible fluorescence of the cargo nanoparticle and the near-infared emission of the carbon-nanotube track. We observed unidirectional movements of the molecular motors over 3 µm with a translocation velocity on the order of 1 nm min(-1) under our experimental conditions.
CD13 (CD13/aminopeptidase N, APN, or CD13/APN) is a widely expressed type II membrane-bound metalloprotease. It is often overexpressed on cancer cells and expressed on CD4(+)CD25(hi) Treg cell subpopulation with higher suppressive ability. It has been determined to be a promising target in cancer diagnosis and therapy. In this study, a functional anti-human CD13 monoclonal antibody, MAb 9E4, was obtained and the specificity of this MAb was verified by flow cytometry. This MAb effectively recognized the CD13 molecule expressed on a series of malignant cell lines. Furthermore, we demonstrated that MAb 9E4 suppresses the suppressive function of Treg cells. This functional anti-human CD13 MAb provides a valuable tool for further study targeting the CD13 positive Treg cells.
A new laser differential confocal lens refractive index measurement is proposed, which uses the absolute zero of the differential confocal axial intensity curve to precisely identify the positions of the objective when the measurement pencil is focused on the vertex of the test lens and the reflector with or without the test lens in the measurement light-path, and then uses aberration compensation and ray tracing facet iterative calculation to obtain the refractive index of the test lens, thereby achieving the high-precision noncontact measurement of lens refractive index. The theoretical analyses and preliminary experiments indicate that the accuracy of the approach can reach about 2.5×10(-4).
Novel platinum nanowheels were synthesized by the reduction of aqueous platinum complex with ascorbic acid in the presence of disk-like bicelles. The platinum nanowheels possess thickened centers and flared edges that are connected by dendritic platinum nanosheets. This structural complexity can be attributed to the inhomogeneous micro-environment of the templating bicelles consisting of a central bi-layer region and a high curvature rim. The formation mechanism of the nanowheels was investigated by imaging nanostructures at different stages of the reaction. The templating bicelles were also imaged by TEM with the aid of negative staining. The variation of reaction parameters including platinum concentration, temperature, and total concentration of surfactants (CTAB + FC7) led to other types of platinum nanostructures, such as circular dendritic nanosheets with a tunable diameter and rectangular dendritic nanosheets. Interestingly, under irradiation by a TEM electron beam, the dendritic nanosheet portion of the nanowheels transforms into a metastable holey sheet. In addition, the platinum nanowheels have an electrochemical active surface area comparable to that of ETEK platinum black and thus are expected to have potential applications in catalysis.
Porphyrin nanotubes were formed by the ionic self-assembly of tetrakis(4-sulfonatophenyl) porphyrin diacid (H(4)TPPS(4)(2-)) and Sn(IV) tetra(4-pyridyl) porphyrin (Sn(OH(-))(X)TPyP(4+/5+) [X = OH(-) or H(2)O]) at pH 2.0. As reported previously, the tubes are hollow as revealed by transmission electron microscopy, approximately 60 nm in diameter, and can be up to several micrometres long. The absorption spectrum of the porphyrin nanotubes presents monomer-like Soret bands, as well as two additional red-shifted bands characteristic of porphyrin J-aggregates (offset face-to-face stacks). To elucidate the origin of the J-aggregate bands and the internal interactions of the porphyrins, the resonance Raman spectra have been obtained for the porphyrin nanotubes with excitations near resonance with the Soret J-aggregate band and the monomer-like bands. The resonance Raman data reveal that the Sn porphyrins are not electronically coupled to the J-aggregates within the tubes, which are formed exclusively by H(4)TPPS(4)(2-). This suggests that the internal structure of the nanotubes has H(4)TPPS(4)(2-) in aggregates that are similar to the widely studied H(4)TPPS(4)(2-) self-aggregates and that are segregated from the Sn porphyrins. Possible internal structures of the nanotubes and mechanisms for their formation are discussed.
Runt-related transcription factor 3 (RUNX3) is a well known gene for its functions in gastric cancer suppression, but the effect of its genetic variations on the risk of gastric cancer remains unclear. In this study, ten tagging single nucleotide polymorphisms (tSNPs) of the RUNX3 gene were selected and genotyped in a hospital-based case-control study of 312 gastric cancer patients and 329 cancer-free controls in a Chinese population. In the single-locus analysis, three RUNX3 intronic tSNPs associated with significantly increased risk of gastric cancer were observed: the SNP3 rs11249206 CC genotype (adjusted odds ratio [OR] = 1.75, 95% confidence interval [CI] = 1.03-2.99), compared with the TT genotype; the SNP7 rs760805 AA genotype (adjusted OR = 1.82, 95% CI = 1.14-2.92), compared with the TT genotype; and the SNP8 rs2236852 GG genotype (adjusted OR = 1.69, 95% CI = 1.05-2.72), compared with the AA genotype. In the combined analyses of these three tSNPs, we found that the combined genotypes with four to six variant (risk) alleles (i.e. SNP3 C, SNP7 A, and SNP8 G alleles) were associated with an increased risk of gastric cancer compared with those with one to three variant (risk) alleles (adjusted OR = 2.00, 95% CI = 1.41-2.85), and this increased risk was more pronounced among subgroups of age > or =65 years, never smokers, and never drinkers. However, no significant association was observed in the clinicopathological features analyses. In conclusion, the RUNX3 genetic variants may modulate the risk of gastric cancer in a Chinese population. Further larger and functional studies are warranted to validate the findings.
Under electron-beam irradiation, dendritic platinum nanosheets structurally evolve into metastable "holey" nanosheets. Monte Carlo simulations of this structural transformation agree well with electron microscope images detailing the ripening process. The experiments and simulations show that nanoscale holes of a critical size are persistent and give holey sheets their morphological stability and sustained high surface area. Platinum nanostructures composed of these holey nanosheets exhibit improved durability in electrocatalytic reactions due to their remarkable ripening resistance.
Gastric cancer (GC) is one of the most common cancers and the leading cause of cancer-related deaths globally. The discovery of microRNAs (miRNAs) provides a new avenue for GC diagnostic and treatment regiments. Currently, a large number of miRNAs have been reported to be associated with the progression of GC, among which miR-378 has been examined to be downregulated in GC tissues and several cell lines. However, the function of miR-378 on GC cells and the mechanisms were less known. Here we found that ectopic expression of miR-378 could inhibit cell proliferation, cell cycle progression, cell migration as well as invasion, and induced cell apoptosis in GC cell line MGC-803. Moreover, we found that oncogene mitogen-activated protein kinase 1 (MAPK1) was a target gene of miR-378 in GC cells, and the tumor-suppressive role of miR-378 might be achieved by the direct interaction with MAPK1. Taken together, our results showed that miR-378 might act as tumor suppressors in GC, and it may provide novel diagnostic and therapeutic options for human GC clinical operation in the future.
The role of costimulatory molecules expressed on lymphocytes and thyrocytes in hyperthyroidism has attracted increasing attention and research has shown a close correlation between variant expression of these molecules on lymphocytes and thyrocytes and the development of GD.
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