LIVIVO - Search results -

Search results

Result 1 - 10 of total 57

Search options

Article ; Online: Epigallocatechin gallate inhibits SNARE‐dependent membrane fusion by blocking trans‐SNARE assembly

Min Zhu / Han Xu / Yuting Jiang / Haijia Yu / Yinghui Liu

FEBS Open Bio, Vol 12, Iss 12, Pp 2111-

2022 Volume 2121

Abstract: Insulin secretion is a signal‐triggered process that requires membrane fusion between the secretory granules and plasma membrane in pancreatic β cells. The exocytosis of insulin is mediated by target‐soluble N‐ethylmaleimide sensitive factor attachment ... ...

Abstract	Insulin secretion is a signal‐triggered process that requires membrane fusion between the secretory granules and plasma membrane in pancreatic β cells. The exocytosis of insulin is mediated by target‐soluble N‐ethylmaleimide sensitive factor attachment protein receptors (SNAREs) on the plasma membrane and vesicle‐SNAREs on the vesicles, which assemble into a quaternary trans‐SNARE complex to initiate the fusion. Expression of fusion proteins is reduced in the islets of patients with type II diabetes, indicating that SNARE‐mediated fusion defect is closely related to insulin‐based metabolic diseases. Previous studies have suggested that epigallocatechin gallate (EGCG) has an inhibitory effect on membrane fusion. In the present study, we performed in vitro reconstitution assays to unravel the molecular mechanisms of EGCG in SNARE‐mediated insulin secretory vesicle fusion. Our data show that EGCG efficiently inhibits insulin secretory SNARE‐mediated membrane fusion. Mechanistic studies indicated that EGCG blocks the formation of the trans‐SNARE complex. Furthermore, calcium/synaptotagmin‐7‐stimulated fusion kinetics were largely reduced by EGCG, confirming that it is a potential regulator of SNARE‐dependent insulin secretion. Our findings suggest that the trans‐SNARE complex might be a promising target for controlling SNARE‐dependent vesicle fusion.
Keywords	EGCG ; exocytosis ; insulin secretion ; membrane fusion ; SNARE ; synaptotagmin ; Biology (General) ; QH301-705.5
Subject code	571
Language	English
Publishing date	2022-12-01T00:00:00Z
Publisher	Wiley
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: A New Perspective on Four Decades of Changes in Arctic Sea Ice from Satellite Observations

Xuanji Wang / Yinghui Liu / Jeffrey R. Key / Richard Dworak

Remote Sensing, Vol 14, Iss 8, p

2022 Volume 1846

Abstract: Arctic sea ice characteristics have been changing rapidly and significantly in the last few decades. Using a long-term time series of sea ice products from satellite observations—the extended AVHRR Polar Pathfinder (APP-x)—trends in sea ice concentration, ...

Abstract	Arctic sea ice characteristics have been changing rapidly and significantly in the last few decades. Using a long-term time series of sea ice products from satellite observations—the extended AVHRR Polar Pathfinder (APP-x)—trends in sea ice concentration, ice extent, ice thickness, and ice volume in the Arctic from 1982 to 2020 are investigated. Results show that the Arctic has become less ice-covered in all seasons, especially in summer and autumn. Arctic sea ice thickness has been decreasing at a rate of −3.24 cm per year, resulting in an approximate 52% reduction in thickness from 2.35 m in 1982 to 1.13 m in 2020. Arctic sea ice volume has been decreasing at a rate of −467.7 km 3 per year, resulting in an approximate 63% reduction in volume, from 27,590.4 km 3 in 1982 to 10,305.5 km 3 in 2020. These trends are further examined from a new perspective, where the Arctic Ocean is classified into open water, perennial, and seasonal sea ice-covered areas based on sea ice persistence. The loss of the perennial sea ice-covered area is a major factor in the total sea ice loss in all seasons. If the current rates of sea ice changes in extent, concentration, and thickness continue, the Arctic is expected to have ice-free summers by the early 2060s.
Keywords	sea ice ; cryosphere ; arctic ocean ; arctic sea ice change ; arctic climate change ; remote sensing retrieval ; Science ; Q
Language	English
Publishing date	2022-04-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: A Blended Sea Ice Concentration Product from AMSR2 and VIIRS

Richard Dworak / Yinghui Liu / Jeffrey Key / Walter N. Meier

Remote Sensing, Vol 13, Iss 2982, p

2021 Volume 2982

Abstract: An effective blended Sea-Ice Concentration (SIC) product has been developed that utilizes ice concentrations from passive microwave and visible/infrared satellite instruments, specifically the Advanced Microwave Scanning Radiometer-2 (AMSR2) and the ... ...

Abstract	An effective blended Sea-Ice Concentration (SIC) product has been developed that utilizes ice concentrations from passive microwave and visible/infrared satellite instruments, specifically the Advanced Microwave Scanning Radiometer-2 (AMSR2) and the Visible Infrared Imaging Radiometer Suite (VIIRS). The blending takes advantage of the all-sky capability of the AMSR2 sensor and the high spatial resolution of VIIRS, though it utilizes only the clear sky characteristics of VIIRS. After both VIIRS and AMSR2 images are remapped to a 1 km EASE-Grid version 2, a Best Linear Unbiased Estimator (BLUE) method is used to combine the AMSR2 and VIIRS SIC for a blended product at 1 km resolution under clear-sky conditions. Under cloudy-sky conditions the AMSR2 SIC with bias correction is used. For validation, high spatial resolution Landsat data are collocated with VIIRS and AMSR2 from 1 February 2017 to 31 October 2019. Bias, standard deviation, and root mean squared errors are calculated for the SICs of VIIRS, AMSR2, and the blended field. The blended SIC outperforms the individual VIIRS and AMSR2 SICs. The higher spatial resolution VIIRS data provide beneficial information to improve upon AMSR2 SIC under clear-sky conditions, especially during the summer melt season, as the AMSR2 SIC has a consistent negative bias near and above the melting point.
Keywords	Arctic ; sea ice concentration ; melting ice ; high spatial resolution ; blending technique ; best-linear unbiased estimator ; Science ; Q
Subject code	290
Language	English
Publishing date	2021-07-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Assessment of AMSR2 Ice Extent and Ice Edge in the Arctic Using IMS

Yinghui Liu / Sean Helfrich / Walter N. Meier / Richard Dworak

Remote Sensing, Vol 12, Iss 1582, p

2020 Volume 1582

Abstract: This work assesses the AMSR2 (the Advanced Microwave Scanning Radiometer 2) ice extent and ice edge in the Arctic using the ice extent products of NOAA’s Interactive Multisensor Snow and Ice Mapping System (IMS) from the period of July 2015 to July 2019. ...

Abstract	This work assesses the AMSR2 (the Advanced Microwave Scanning Radiometer 2) ice extent and ice edge in the Arctic using the ice extent products of NOAA’s Interactive Multisensor Snow and Ice Mapping System (IMS) from the period of July 2015 to July 2019. Daily values and monthly means of four statistical scores (hit rate, false alarm ratio, false alarm rate, and Hanssen-Kuiper Skill Score) over the Arctic Ocean show distinct annual cycles. IMS ice edges often extend further south compared to those from AMSR2, with up to 100 km differences over the Beaufort, Chukchi, and East Siberian Seas in August and September.
Keywords	sea ice ; sea ice extent ; sea ice edge ; AMSR2 ; IMS ; Arctic ; Science ; Q
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Endoplasmic Reticulum–Plasma Membrane Contact Sites

Chenlu Li / Tiantian Qian / Ruyue He / Chun Wan / Yinghui Liu / Haijia Yu

Frontiers in Cell and Developmental Biology, Vol

Regulators, Mechanisms, and Physiological Functions

2021 Volume 9

Abstract: The endoplasmic reticulum (ER) forms direct membrane contact sites with the plasma membrane (PM) in eukaryotic cells. These ER-PM contact sites play essential roles in lipid homeostasis, ion dynamics, and cell signaling, which are carried out by protein- ... ...

Abstract	The endoplasmic reticulum (ER) forms direct membrane contact sites with the plasma membrane (PM) in eukaryotic cells. These ER-PM contact sites play essential roles in lipid homeostasis, ion dynamics, and cell signaling, which are carried out by protein-protein or protein-lipid interactions. Distinct tethering factors dynamically control the architecture of ER-PM junctions in response to intracellular signals or external stimuli. The physiological roles of ER-PM contact sites are dependent on a variety of regulators that individually or cooperatively perform functions in diverse cellular processes. This review focuses on proteins functioning at ER-PM contact sites and highlights the recent progress in their mechanisms and physiological roles.
Keywords	membrane contact sites (MCSs) ; endoplasmic reticulum (ER) ; plasma membrane ; tether ; lipid transfer ; enzyme ; Biology (General) ; QH301-705.5
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Ice Surface Temperature Retrieval from a Single Satellite Imager Band

Yinghui Liu / Richard Dworak / Jeffrey Key

Remote Sensing, Vol 10, Iss 12, p

2018 Volume 1909

Abstract: Current methods for estimating the surface temperature of sea and lake ice—the ice surface temperature (IST)—utilize two satellite imager thermal bands (11 and 12 μm) at moderate spatial resolution. These “split-window„ or dual-band methods have been ... ...

Abstract	Current methods for estimating the surface temperature of sea and lake ice—the ice surface temperature (IST)—utilize two satellite imager thermal bands (11 and 12 μm) at moderate spatial resolution. These “split-window„ or dual-band methods have been shown to have low biases and uncertainties. A single-band algorithm would be useful for satellite imagers that have only the 11 μm band at high resolution, such as the Visible Infrared Imaging Radiometer Suite (VIIRS), or that do not have a fully functional 12 μm band, such as the Thermal Infrared Sensor onboard the Landsat 8. This study presents a method for single-band IST retrievals, and validation of the retrievals using IST measurements from an airborne infrared radiation pyrometer during the NASA IceBridge campaign in the Arctic. Results show that IST with a single thermal band from the VIIRS has comparable performance to IST with the VIIRS dual-band (split-window) method, with a bias of 0.22 K and root-mean-square error of 1.03 K.
Keywords	sea ice ; ice surface temperature ; Suomi NPP ; JPSS ; remote sensing ; Science ; Q
Subject code	290
Language	English
Publishing date	2018-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Robust SiO 2 –Al 2 O 3 /Agarose Composite Aerogel Beads with Outstanding Thermal Insulation Based on Coal Gangue

Jie Gu / Chao Ji / Rui Fu / Xin Yang / Zhichen Wan / Lishuo Wen / Qiqi Song / Yinghui Liu / Yaxiong Wang / Huazheng Sai

Gels, Vol 8, Iss 165, p

2022 Volume 165

Abstract: Advanced SiO 2 –Al 2 O 3 aerogel materials have outstanding potential in the field of thermal insulation. Nevertheless, the creation of a mechanically robust and low-cost SiO 2 –Al 2 O 3 aerogel material remains a considerable challenge. In this study, ... ...

Abstract	Advanced SiO 2 –Al 2 O 3 aerogel materials have outstanding potential in the field of thermal insulation. Nevertheless, the creation of a mechanically robust and low-cost SiO 2 –Al 2 O 3 aerogel material remains a considerable challenge. In this study, SiO 2 –Al 2 O 3 aerogel based on coal gangue, which is a type of zero-cost inorganic waste, was constructed in porous agarose aerogel beads, followed by simple chemical vapor deposition of trimethylchlorosilane to fabricate SiO 2 –Al 2 O 3 /agarose composite aerogel beads (SCABs). The resulting SCABs exhibited a unique nanoscale interpenetrating network structure, which is lightweight and has high specific surface area (538.3 m 2 /g), hydrophobicity (approximately 128°), and excellent thermal stability and thermal insulation performance. Moreover, the compressive strength of the SCABs was dramatically increased by approximately a factor of ten compared to that of native SiO 2 –Al 2 O 3 aerogel beads. The prepared SCABs not only pave the way for the design of a novel aerogel material for use in thermal insulation without requiring expensive raw materials, but also provide an effective way to comprehensively use coal gangue.
Keywords	aerogel materials ; composite materials ; SiO 2 –Al 2 O 3 ; coal gangue ; mechanical properties ; thermal properties ; Science ; Q ; Chemistry ; QD1-999 ; Inorganic chemistry ; QD146-197 ; General. Including alchemy ; QD1-65
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: A novel fluorogenic reporter substrate for 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-2 (PLCγ2)

Ramya Visvanathan / Tadanobu Utsuki / Daniel E. Beck / Emma Lendy / Kuai-lin Sun / Yinghui Liu / Kirk W. Hering / Andrew Mesecar / Zhong-Yin Zhang / Karson S. Putt

SLAS Discovery, Vol 28, Iss 4, Pp 170-

Application to high-throughput screening for activators to treat Alzheimer's disease

2023 Volume 179

Abstract: A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's ... ...

Abstract	A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease (LOAD) and therefore, activation of wild-type PLCγ2 has been suggested as a potential therapeutic target for the prevention and treatment of LOAD. Additionally, PLCγ2 has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLCγ2 activity have been identified. Here, pharmacological inhibition may provide a therapeutic effect. In order to facilitate our investigation of the activity of PLCγ2, we developed an optimized fluorogenic substrate to monitor enzymatic activity in aqueous solution. This was accomplished by first exploring the spectral properties of various “turn-on” fluorophores. The most promising turn-on fluorophore was incorporated into a water-soluble PLCγ2 reporter substrate, which we named C8CF3-coumarin. The ability of PLCγ2 to enzymatically process C8CF3-coumarin was confirmed, and the kinetics of the reaction were determined. Reaction conditions were optimized to identify small molecule activators, and a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) was performed with the goal of identifying small molecule activators of PLCγ2. The optimized screening conditions allowed identification of potential PLCγ2 activators and inhibitors, thus demonstrating the feasibility of this approach for high-throughput screening.
Keywords	Alzheimer's disease ; Phospholipase C ; PLCG2 ; C8CF3-coumarin ; Turn-on fluorophore ; High throughput screening ; Medicine (General) ; R5-920 ; Biotechnology ; TP248.13-248.65
Subject code	540
Language	English
Publishing date	2023-06-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Insights into the molecular mechanism of dehalogenation catalyzed by D-2-haloacid dehalogenase from crystal structures

Yayue Wang / Yanbin Feng / Xupeng Cao / Yinghui Liu / Song Xue

Scientific Reports, Vol 8, Iss 1, Pp 1-

2018 Volume 9

Abstract: Abstract D-2-haloacid dehalogenases (D-DEXs) catalyse the hydrolytic dehalogenation of D-2-haloacids, releasing halide ions and producing the corresponding 2-hydroxyacids. A structure-guided elucidation of the catalytic mechanism of this dehalogenation ... ...

Abstract	Abstract D-2-haloacid dehalogenases (D-DEXs) catalyse the hydrolytic dehalogenation of D-2-haloacids, releasing halide ions and producing the corresponding 2-hydroxyacids. A structure-guided elucidation of the catalytic mechanism of this dehalogenation reaction has not been reported yet. Here, we report the catalytic mechanism of a D-DEX, HadD AJ1 from Pseudomonas putida AJ1/23, which was elucidated by X-ray crystallographic analysis and the H218O incorporation experiment. HadD AJ1 is an α-helical hydrolase that forms a homotetramer with its monomer including two structurally axisymmetric repeats. The product-bound complex structure was trapped with L-lactic acid in the active site, which is framed by the structurally related helices between two repeats. Site-directed mutagenesis confirmed the importance of the residues lining the binding pocket in stabilizing the enzyme-substrate complex. Asp205 acts as a key catalytic residue and is responsible for activating a water molecule along with Asn131. Then, the hydroxyl group of the water molecule directly attacks the C2 atom of the substrate to release the halogen ion instead of forming an enzyme-substrate ester intermediate as observed in L-2-haloacid dehalogenases. The newly revealed structural and mechanistic information on D-DEX may inspire structure-based mutagenesis to engineer highly efficient haloacid dehalogenases.
Keywords	Medicine ; R ; Science ; Q
Subject code	540
Language	English
Publishing date	2018-01-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Application of a Convolutional Neural Network for the Detection of Sea Ice Leads

Jay P. Hoffman / Steven A. Ackerman / Yinghui Liu / Jeffrey R. Key / Iain L. McConnell

Remote Sensing, Vol 13, Iss 4571, p

2021 Volume 4571

Abstract: Despite accounting for a small fraction of the surface area in the Arctic, long and narrow sea ice fractures, known as “leads”, play a critical role in the energy flux between the ocean and atmosphere. As the volume of sea ice in the Arctic has declined ... ...

Abstract	Despite accounting for a small fraction of the surface area in the Arctic, long and narrow sea ice fractures, known as “leads”, play a critical role in the energy flux between the ocean and atmosphere. As the volume of sea ice in the Arctic has declined over the past few decades, it is increasingly important to monitor the corresponding changes in sea ice leads. A novel approach has been developed using artificial intelligence (AI) to detect sea ice leads using satellite thermal infrared window data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS). In this new approach, a particular type of convolutional neural network, a U-Net, replaces a series of conventional image processing tests from our legacy algorithm. Results show the new approach has a high detection accuracy with F1 Scores on the order of 0.7. Compared to the legacy algorithm, the new algorithm shows improvement, with more true positives, fewer false positives, fewer false negatives, and better agreement between satellite instruments.
Keywords	leads ; sea ice ; MODIS ; VIIRS ; convolutional neural network ; U-Net ; Science ; Q
Subject code	290
Language	English
Publishing date	2021-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED