Background and Aim
Irritable bowel syndrome (IBS) is a highly prevalent chronic functional gastrointestinal disorder. Recent studies have showed increasing important role of gut microbiota in the ...pathophysiological changes of IBS. Our study aims to elaborate the association between intestinal flora with the genesis and the development of IBS.
Methods
Illumina high‐throughput sequencing technology was applied to investigate microbial communities of IBS patients and healthy donors. Stool specimens from the IBS‐D patients were equally premixed and implanted into germ free C57B/6 mice to construct IBS animal model, and the normal group was also transplanted with normal premixed feces. The post‐transplant defecation and intra‐epithelial lymphocyte counts were evaluated. Microbial communities were also checked by the illumina high‐throughput sequencing technology.
Results
Fifteen genuses significantly different were found expressed in the gut flora of IBS patients, and six genuses showed significantly different abundances between the stool specimens of mice of IBS group and normal group. Among these differences, Parasutterella expression was remarkably different in both screening and validation experiments and also related to chronic intestinal inflammation; therefore, Parasutterella expression is considered in association with the development and progression of IBS.
Conclusion
Parasutterella may be related with the genesis and development of IBS and also associated with chronic intestinal inflammation in IBS patients.
It is difficult to accurately estimate species richness if there are many almost undetectable species in a hyper‐diverse community. Practically, an accurate lower bound for species richness is ...preferable to an inaccurate point estimator. The traditional nonparametric lower bound developed by Chao (1984, Scandinavian Journal of Statistics 11, 265–270) for individual‐based abundance data uses only the information on the rarest species (the numbers of singletons and doubletons) to estimate the number of undetected species in samples. Applying a modified Good–Turing frequency formula, we derive an approximate formula for the first‐order bias of this traditional lower bound. The approximate bias is estimated by using additional information (namely, the numbers of tripletons and quadrupletons). This approximate bias can be corrected, and an improved lower bound is thus obtained. The proposed lower bound is nonparametric in the sense that it is universally valid for any species abundance distribution. A similar type of improved lower bound can be derived for incidence data. We test our proposed lower bounds on simulated data sets generated from various species abundance models. Simulation results show that the proposed lower bounds always reduce bias over the traditional lower bounds and improve accuracy (as measured by mean squared error) when the heterogeneity of species abundances is relatively high. We also apply the proposed new lower bounds to real data for illustration and for comparisons with previously developed estimators.
Stochastic DNA walkers capable of traversing on three-dimensional (3D) tracks have received great deal of attention. However, DNA walker-based biosensors exhibit limited amplification efficiency ...because of their slow walking kinetics and low processivity. Herein, by taking advantage of the high processivity of a DNA rolling machine, a sensitive ratiometric DNA nanomachine biosensor is designed. The biosensor is constructed with hairpin-loaded Au nanoparticles (NPs) (hpDNA@AuNPs) as a DNA walker and AgNCs-decorated magnetic NPs (AgNCs@MNPs) as a DNA rolling machine. In the presence of target DNA, exonuclease III (Exo III)-powered DNA walker is activated to accomplish first-stage amplification via a burnt-bridge mechanism, generating a great deal of toehold-loaded AuNPs (Toehold@AuNPs) to hybridize with magnetic nanoparticles loaded with silver-nanoclusters-labeled DNA (AgNCs@MNPs) with the assistance of Exo III. These trigger rapid rolling of AuNPs on the AgNCs@MNPs surface and release free AgNCs, converting the biological signal into a mass spectrometric signal ratio (107Ag/197Au) with detection by ICP-MS. A linear range of 0.5–500 fmol L–1 is achieved with a detection limit of 119 amol L–1 for the p53 gene. The practical applicability of the biosensor has been demonstrated in the accurate assay of the p53 gene in the human blood.
Public support has long been considered crucial for the vitality and survival of democracy. Although the determinants of citizens' support for democracy have been extensively studied, current ...literature puts emphasis on domestic factors. While another body of scholarship has documented the propensity of political diffusion, most studies focus on aggregate outcomes, and citizens' attitudes within this tendency have received less attention. Extending the research on the influence of domestic performance on public attitudes and verifying the micro-foundation underlying political diffusion, we argue that economic performance of other countries can similarly shape citizens' support for democracy. Using a sample of more than 90 democratic countries across the globe over the past three decades, we find that citizens in democratic countries are more likely to view democracy as the ideal regime type when there is a positive correlation between the level of democracy and economic growth across proximate countries, either geographically or culturally defined. We also show that the effects of proximate foreign democracies' economic performance in boosting democratic support are particularly evident in countries where citizens have greater access to external information, as they are more aware of the political systems and economic conditions of foreign countries.
A broad variety of unactivated acyclic and alicyclic substrates cleanly undergo site‐selective alkenylation of unactivated C(sp3)−H bonds with 1,2‐bis(phenylsulfonyl)ethene in the presence of ...persulfate. This simple transformation furnishes (E)‐2‐alkylvinylphenylsulfones in up to 88 % yield. In contrast with the previously reported decatungstate protocol, the current method is applicable to alkenylation of sterically hindered C−H bonds. This important advantage significantly broadens the substrate scope, and is attributed to the compact size of the sulfate radical employed in the C−H activation and cleavage.
Reported here is a new protocol using persulfate anion for site‐selective C(sp3)−H alkenylation with 1,2‐bis(phenylsulfonyl)ethene. As shown, the alkenylation of (3aR)‐(+)‐sclareolide occurs site‐selectively at C8 in spite of the presence of 18 types of C(sp3)−H bonds in the molecule. The hydrogen‐atom transfer reaction by the sulfate radical follows radical polar effects, akin to the decatungstate anion but with a more controlled steric effect.
Site‐selective C(sp3)‐H alkenylation was achieved under photo‐irradiation in the presence of a catalytic amount of decatungstate anion, W10O324−. In this reaction, the radical addition/β‐scission ...sequence is successfully combined with photocatalytic C(sp3)‐H functionalization. The reaction using weaker C−H bonds such as those in THF revealed that the benzenesulfonyl radical itself underwent HAT directly from the C−H bond, and a decatungstate anion participated in a chain‐repairing step.
Interfacial self‐assembly is a powerful organizational force for fabricating functional nanomaterials, including nanocarriers, for imaging and drug delivery. Herein, the interfacial self‐assembly of ...pH‐responsive metal–phenolic networks (MPNs) on the liquid–liquid interface of oil‐in‐water emulsions is reported. Oleic acid emulsions of 100–250 nm in diameter are generated by ultrasonication, to which poly(ethylene glycol) (PEG)‐based polyphenolic ligands are assembled with simultaneous crosslinking by metal ions, thus forming an interfacial MPN. PEG provides a protective barrier on the emulsion phase and renders the emulsion low fouling. The MPN‐coated emulsions have a similar size and dispersity, but an enhanced stability when compared with the uncoated emulsions, and exhibit a low cell association in vitro, a blood circulation half‐life of ≈50 min in vivo, and are nontoxic to healthy mice. Furthermore, a model anticancer drug, doxorubicin, can be encapsulated within the emulsion phase at a high loading capacity (≈5 fg of doxorubicin per emulsion particle). The MPN coating imparts pH‐responsiveness to the drug‐loaded emulsions, leading to drug release at cell internalization pH and a potent cell cytotoxicity. The results highlight a straightforward strategy for the interfacial nanofabrication of pH‐responsive emulsion–MPN systems with potential use in biomedical applications.
Low‐fouling, biodegradable oil‐in‐water emulsions with diameters of 100–250 nm are produced by the self‐assembly of metal–phenolic networks at the interface of emulsions. The coated emulsions are stable and exhibit a high drug‐loading capacity and offer promise as a therapeutic nanocarrier.
This study tests the relationship between democracy and population health. Some studies argue that democracies are more likely than authoritarian regimes to provide public goods and, thus, enhance ...health. However, recent research has challenged this argument and identified good governance as the crucial determinant of human development. Using a newly collected dataset covering 173 countries from 1900 to 2012, our analyses show that across models with various specifications, democratic elections have consistent effects on health outcomes even when other important factors, including good governance, are taken into account. There are some nuances in this relationship. First, the impact of electoral democracy tends to persist over time. Furthermore, the positive effects are particularly salient once the quality of elections has achieved a certain threshold. Our results also suggest that previous studies yielded mixed results in part because the commonly used governance indicators are only available for relatively short time periods, and the sample does not reflect the entire range of variation in measures of both democracy and governance.
Extracellular vesicles (EVs) are released by nearly all cell types as part of normal cell physiology, transporting biological cargo, including nucleic acids and proteins, across the cell membrane. In ...pathological states such as cancer, EV-derived cargo may mirror the altered state of the cell of origin. Exosomes are the smaller, 50–150 nanometer-sized EVs released from fusion of multivesicular endosomes with the plasma membrane. Exosomes play important roles in cell-cell communication and participate in multiple cancer processes, including invasion and metastasis. Therefore, proteomic analysis of exosomes is a promising approach to discover potential cancer biomarkers, even though it is still at an early stage. Herein, we critically review the advances in exosome isolation methods and their compatibility with mass spectrometry (MS)-based proteomic analysis, as well as studies of exosomes in pathogenesis and progression of prostate and bladder cancer, two common urologic cancers whose incidence rates continue to rise annually. As urological tumors, both urine and blood samples are feasible for noninvasive or minimally invasive analysis. A better understanding of the biological cargo and functions of exosomes via high-throughput proteomics will help provide new insights into complex alterations in cancer and provide potential therapeutic targets and personalized treatment for patients.
Using both a cross-national data set on parties’ accountability strategies and public opinion survey data, this article provides a systematic analysis of how parties’ reliance on clientelistic ...strategies correlates with citizen evaluations of regime performance. Our analyses suggest that in systems where parties in general rely more heavily on clientelism, principles of democratic equality are undermined, and citizens on average express a lower level of satisfaction. In addition to democratic norms, material benefits are also closely related to citizens’ regime evaluations. Within countries, supporters of parties that make substantial clientelistic efforts are more satisfied than other citizens, because they are likely to be beneficiaries of this accountability mode. This within-country gap between clientelistic and non-clientelistic parties’ supporters widens where the clientelistic parties deliver benefits more effectively and in countries with lower overall democratic quality.
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