419 research outputs found
Development of Functional Microfold (M) Cells from Intestinal Stem Cells in Primary Human Enteroids.
Background & aimsIntestinal microfold (M) cells are specialized epithelial cells that act as gatekeepers of luminal antigens in the intestinal tract. They play a critical role in the intestinal mucosal immune response through transport of viruses, bacteria and other particles and antigens across the epithelium to immune cells within Peyer's patch regions and other mucosal sites. Recent studies in mice have demonstrated that M cells are generated from Lgr5+ intestinal stem cells (ISCs), and that infection with Salmonella enterica serovar Typhimurium increases M cell formation. However, it is not known whether and how these findings apply to primary human small intestinal epithelium propagated in an in vitro setting.MethodsHuman intestinal crypts were grown as monolayers with growth factors and treated with recombinant RANKL, and assessed for mRNA transcripts, immunofluorescence and uptake of microparticles and S. Typhimurium.ResultsFunctional M cells were generated by short-term culture of freshly isolated human intestinal crypts in a dose- and time-dependent fashion. RANKL stimulation of the monolayer cultures caused dramatic induction of the M cell-specific markers, SPIB, and Glycoprotein-2 (GP2) in a process primed by canonical WNT signaling. Confocal microscopy demonstrated a pseudopod phenotype of GP2-positive M cells that preferentially take up microparticles. Furthermore, infection of the M cell-enriched cultures with the M cell-tropic enteric pathogen, S. Typhimurium, led to preferential association of the bacteria with M cells, particularly at lower inoculum sizes. Larger inocula caused rapid induction of M cells.ConclusionsHuman intestinal crypts containing ISCs can be cultured and differentiate into an epithelial layer with functional M cells with characteristic morphological and functional properties. This study is the first to demonstrate that M cells can be induced to form from primary human intestinal epithelium, and that S. Typhimurium preferentially infect these cells in an in vitro setting. We anticipate that this model can be used to generate large numbers of M cells for further functional studies of these key cells of intestinal immune induction and their impact on controlling enteric pathogens and the intestinal microbiome
Magnifier or refractor? Exploring the impact of geographical indication on people’s perception of the value of cultural ecosystem services based on the SolVES model
Purpose/SignificanceTo a certain extent, geographical indication (GI) protects the ecosystem of product origin, but there is still a lack of quantitative evidence on its cultural spillover effect. The mechanism of the impact of geo-certified landscapes on people’s perceived value of cultural ecosystem services (CESs) should be explored.Methods/ProceduresIn this study, two urban forest parks, Changqing and Zhongshan, which differ mainly in terms of geo-certified landscapes, were selected in Beihai, Guangxi. Basically, homogeneous volunteers were recruited, and photos of value labels were collected from their independent visits to two parks. The SolVES model was used to explore the effect of the presence or absence of geo-certified landscapes in urban park ecosystems on people’s CESs needs and the relation to the spatial context of the landscape.Results/ConclusionsThe results show that GI significantly enhance people’s perception of human CESs value of landscape elements, and clarifies the correspondence perception relationship between CESs value types and each landscape element. In addition to the spillover effect on humanistic value perception, GI also attracts and transfers people’s esthetic attention to the natural landscape itself to a certain extent. And these two effects will also spread to the ecosystem that the landscape belongs to
Future Healthy Oil: Precision Nutrition and Moderate Processing
Oil is a significant source of fatty acids and various trace functional components, and plays a vital role in regulating human health. The macro- and micro-components in oils are closely related to nutritional health. This paper introduces the future development goals and strategies of healthy oils from two aspects of precise nutrition and moderate processing. Firstly, precise nutrition based on life cycle and physiological state is a priority research area of lipid science. On the other hand, moderate processing will retain nutrients such as vitamin E, phytosterols, and squalene to a greater extent, and avoid the formation of risk factors such as trans fatty acids, 3-chloropropanol esters, and glycidyl esters. Moderate processing not only ensures the safety of oil, but also reduces the loss of healthy and beneficial fat concomitants, which is the development direction of oil engineering research. Therefore, under the dual demands of nutrition and safety, accurate nutrition and moderate processing of oils will help the implementation of "Healthy China" and "Double- Carbon" strategies. Future healthy oils will not only provide basic nutrition and flavor, but also give specific health functions to people with different life cycles, such as infants, children, adolescents, adults and the elderly, and maintain the homeostasis of people with different physiological states including pregnant and lactating women
Intestinal Subepithelial Myofibroblasts Support in vitro and in vivo Growth of Human Small Intestinal Epithelium
The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs) and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth
Altered spontaneous brain activity patterns in patients with unilateral acute open globe injury using amplitude of low-frequency fluctuation: a functional magnetic resonance imaging study
Modelling environmental changes and effects on wild-caught species in Queensland. Environmental drivers.
We report on the findings of a collaborative research project that was designed to identify and measure the effects of environmental drivers on the abundance and population dynamics of key Queensland fishery species. The project was co-funded by the Commonwealth Government’s Fisheries Research and Development Corporation (FRDC) and carried out by a multi-disciplinary team of scientists from the University of Queensland (UQ), the Queensland Department of Agriculture and Fisheries (DAF) and the Australian Institute of Marine Science (AIMS). The research team applied modern statistical, data science and modelling techniques in combination with biological insights into the life cycles of the three target species.
Background
With increasing evidence that environmental conditions in the marine environment are changing rapidly, it is becoming ever more important to understand how these changes may impact on the population dynamics and abundance of important fish stocks. Understanding the influence of environmental conditions can provide greater certainty that the risk of overfishing (under adverse environmental conditions) or under harvesting (under favourable conditions) are accounted for by resource managers.
This project aimed to identify the environmental factors which may be influencing the recruitment, catchability or productivity of Snapper, Pearl Perch, and Spanner Crab stocks in Queensland. Results from this work will support sustainable management of Queensland’s fisheries by directly informing the assessment and management of these key species within Queensland waters
Altered spontaneous brain activity pattern in patients with late monocular blindness in middle-age using amplitude of low-frequency fluctuation: a resting-state functional MRI study
A Miniature Fiber Optic Refractive Index Sensor Built in a MEMS-Based Microchannel
A small, highly sensitive, and electromagnetic interference (EMI)-immune refractive index (RI) sensor based on the Fabry-Perot (FP) interferometer is presented. The sensor’s FP cavity was fabricated by aligning two metal-deposited, single-mode optical fiber endfaces inside a microchannel on a silicon chip. The mirrors on the fiber endfaces were made of thermal-deposited metal films, which provided the high finesse necessary to produce a highly sensitive sensor. Microelectromechanical systems (MEMS) fabrication techniques, specifically photolithography and deep dry etching, were used to precisely control the profile and depth of the microchannel on the silicon chip with an accuracy of 2 μm. The RI change within the FP cavity was determined by demodulating the transmission spectrum phase shift. The sensitivity and finesse of the transmission spectrum were controlled by adjusting the cavity length and the thickness of the deposited metal. Our experimental results showed that the sensor’s sensitivity was 665.90 nm/RIU (RI Unit), and the limit of detection was 6 × 10−6 RIU. Using MEMS fabrication techniques to fabricate these sensors could make high yield mass production a real possibility. Multiple sensors could be integrated on a single small silicon chip to simultaneously measure RI, temperature, and biomolecule targets
The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys
We present new quasars discovered in the vicinity of the Andromeda and
Triangulum galaxies with the LAMOST during the 2010 and 2011 observational
seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m
telescope, XSTPS optical, and WISE near infrared photometric data. We present
509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along
the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new
quasars discovered in an area of ~100 sq. deg that covers the central region
and the southeastern halo of M31 in the 2010 commissioning datasets. These 526
new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to
3.2. They represent a significant increase of the number of identified quasars
in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in
this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0
respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars
provide an invaluable collection with which to probe the kinematics and
chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars
are now known with locations within 2.5 deg of M31, of which 73 are newly
discovered. Tens of quasars are now known to be located behind the Giant
Stellar Stream, and hundreds behind the extended halo and its associated
substructures of M31. The much enlarged sample of known quasars in the vicinity
of M31 and M33 can potentially be utilized to construct a perfect astrometric
reference frame to measure the minute PMs of M31 and M33, along with the PMs of
substructures associated with the Local Group of galaxies. Those PMs are some
of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte
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