Detecting xylene gas is an important means of avoiding human harm from gas poisoning. A precise measurement demands that the gas sensor used must have high sensitivity, high selectivity, and low ...working temperature. To meet these requirements, in this study, Sn2+-doped NiO flower-like microspheres (SNM) with different amounts of Sn2+ synthesized by a one-step hydrothermal process were investigated. The responses of gas sensors based on different Sn2+-doped NiO materials for various targeting gases were fully characterized. It was found that all of the synthesized materials exhibited the best gas response at a working temperature of 180 degrees, which was much lower than the previously reported working temperature range of 300–500 degrees. When exposed to 10 ppm xylene, the 8 at% Sn2+-doped NiO sensor (mol ratio) exhibited the highest response, with a value of 30 (Rg/Ra). More significantly, the detection limit of the 8 at% Sn2+-doped NiO sensor for xylene is down in the ppb level. The Sn2+-doped NiO material also exhibits excellent selectivity for other gases with long-term stability and repeatability. The significant improvement in the response to xylene can theoretically be attributed to a decrease in the intrinsic hole carrier concentration, higher amounts of adsorbed oxygen and active sites.
Fast, sensitive, and precise detection of nitric oxide (NO) is critical to many applications in environmental monitoring and early disease diagnosis via respiratory testing. An effective detection ...system requires a sensor to detect NO gas at the parts per billion (ppb) level, and this system should possess a high degree of anti-interference selectivity. To achieve these targets, a series of gas sensor thin films based on intrinsic WO
, one-additive-doped WO
(prepared by doping In
O
or Nb
O
), and two-additive-doped WO
(synthesized by doping with In
O
and Nb
O
) oxides were successfully grown. By analyzing the properties of sensitivity, selectivity, responsiveness, and recovery time of the gas sensors, we found that WO
-1wt%In
O
-1wt%Nb
O
has overwhelming advantages over intrinsic WO
, WO
-In
O
, and WO
-Nb
O
. A sensing response value of 2.4 was observed for NO concentrations as low as 20 ppb from the WO
-1wt%In
O
-1wt%Nb
O
sensor. With 100 ppb NO gas, the WO
-1wt%In
O
-1wt%Nb
O
sensor achieved a high response of 56.1 at 70 °C, which is a state-of-the-art performance for NO detection at low working temperature settings. WO
-1wt%In
O
-1wt%Nb
O
also yields significantly improved selectivity and stability over intrinsic WO
, WO
-In
O
, and WO
-Nb
O
. Studies on the sensing mechanism show that the grain size, rather than the n-n heterostructure effect, plays a dominant role in the observed results. By decreasing the grain size so that it is close to the thickness of the space-charge layer, the sensing response is enhanced. Although room remains to further improve the sensing properties, the performance of WO
-1wt%In
O
-1wt%Nb
O
is sufficient for implementation in low-content NO detection devices.
Fast, sensitive, and precise detection of nitric oxide (NO) is critical to many applications in environmental monitoring and early disease diagnosis via respiratory testing. An effective detection ...system requires a sensor to detect NO gas at the parts per billion (ppb) level, and this system should possess a high degree of anti-interference selectivity. To achieve these targets, a series of gas sensor thin films based on intrinsic WO3, one-additive-doped WO3 (prepared by doping In2O3 or Nb2O5), and two-additive-doped WO3 (synthesized by doping with In2O3 and Nb2O5) oxides were successfully grown. By analyzing the properties of sensitivity, selectivity, responsiveness, and recovery time of the gas sensors, we found that WO3-1wt%In2O3-1wt%Nb2O5 has overwhelming advantages over intrinsic WO3, WO3-In2O3, and WO3-Nb2O5. A sensing response value of 2.4 was observed for NO concentrations as low as 20 ppb from the WO3-1wt%In2O3-1wt%Nb2O5 sensor. With 100 ppb NO gas, the WO3-1wt%In2O3-1wt%Nb2O5 sensor achieved a high response of 56.1 at 70 °C, which is a state-of-the-art performance for NO detection at low working temperature settings. WO3-1wt%In2O3-1wt%Nb2O5 also yields significantly improved selectivity and stability over intrinsic WO3, WO3-In2O3, and WO3-Nb2O5. Studies on the sensing mechanism show that the grain size, rather than the n–n heterostructure effect, plays a dominant role in the observed results. By decreasing the grain size so that it is close to the thickness of the space-charge layer, the sensing response is enhanced. Although room remains to further improve the sensing properties, the performance of WO3-1wt%In2O3-1wt%Nb2O5 is sufficient for implementation in low-content NO detection devices.
Detecting xylene gas is an important means of avoiding human harm from gas poisoning. A precise measurement demands that the gas sensor used must have high sensitivity, high selectivity, and low ...working temperature. To meet these requirements, in this study, Sn
-doped NiO flower-like microspheres (SNM) with different amounts of Sn
synthesized by a one-step hydrothermal process were investigated. The responses of gas sensors based on different Sn
-doped NiO materials for various targeting gases were fully characterized. It was found that all of the synthesized materials exhibited the best gas response at a working temperature of 180 degrees, which was much lower than the previously reported working temperature range of 300-500 degrees. When exposed to 10 ppm xylene, the 8 at% Sn
-doped NiO sensor (mol ratio) exhibited the highest response, with a value of 30 (R
/R
). More significantly, the detection limit of the 8 at% Sn
-doped NiO sensor for xylene is down in the ppb level. The Sn
-doped NiO material also exhibits excellent selectivity for other gases with long-term stability and repeatability. The significant improvement in the response to xylene can theoretically be attributed to a decrease in the intrinsic hole carrier concentration, higher amounts of adsorbed oxygen and active sites.
TWENTY-ONE-YEAR-OLD Du Tiewang was in the spotlight at the 10th Far East and South Pacific Games for the Disabled (FESPIC) held in Bangkok, Thailand, earlier this year. He snatched a gold medal in ...the long jump competition at 5.99 metres,only one centimetre away from the world record. His years of hard work has paid off. Du was born into a peasant family in Wudi County of Shandong Province in 1978. At the age of 6 he lost his arms in an accident, which has completely changed his life.
CRISPR-Cas9 has become a powerful and popular gene editing tool. However, successful application of this tool in the lab can still be quite daunting to many newcomers to molecular biology, mostly ...because it is a relatively lengthy process involving multiple steps with variations of each step. Here, we provide a reliable, stepwise, and newcomer-friendly protocol to knock out a target gene in wild-type human fibroblasts. This protocol involves sgRNA design using CRISPOR, construction of an "all-in-one" vector expressing both sgRNA and Cas9 using Golden Gate cloning, streamlined production of high-titer lentiviruses in 1 week after molecular cloning, and transduction of cells to generate a knockout cell pool. We further introduce a protocol for lentiviral transduction of ex vivo mouse embryonic salivary epithelial explants. In summary, our protocol is useful for new researchers to apply CRISPR-Cas9 to generate stable gene knockout cells and tissue explants using lentivirus. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. Basic Protocol 1: sgRNA design Basic Protocol 2: Cloning sgRNA in plasmid vector containing Cas9 encoding sequence using golden gate cloning Basic Protocol 3: Lentivirus packaging Basic Protocol 4: Lentivirus transduction of cells Basic Protocol 5: Lentivirus transduction of salivary gland epithelial buds.
We have discovered that basement membrane and its major components can induce rapid, strikingly robust fibronectin organization. In this new matrix assembly mechanism, α5β1 integrin-based focal ...adhesions slide actively on the underlying matrix toward the ventral cell center through the dynamic shortening of myosin IIA-associated actin stress fibers to drive rapid fibronectin fibrillogenesis distal to the adhesion. This mechanism contrasts with classical fibronectin assembly based on stable or fixed-position focal adhesions containing αVβ3 integrins plus α5β1 integrin translocation into proximal fibrillar adhesions. On basement membrane components, these sliding focal adhesions contain standard focal adhesion constituents but completely lack classical αVβ3 integrins. Instead, peripheral α3β1 or α2β1 adhesions mediate initial cell attachment but over time are switched to α5β1 integrin-based sliding focal adhesions to assemble fibronectin matrix. This basement-membrane-triggered mechanism produces rapid fibronectin fibrillogenesis, providing a mechanistic explanation for the well-known widespread accumulation of fibronectin at many organ basement membranes.
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•Basement membrane matrix molecules can rapidly induce robust fibronectin assembly•A contractile actomyosin winch drives focal adhesion sliding and matrix assembly•Integrin switching mediates focal adhesion dynamics and fibronectin matrix assembly
Lu et al. report that basement membranes can induce robust cellular fibronectin assembly using a contractile actomyosin winch, pulling on sliding focal adhesions to generate abundant fibronectin fibrils. This process involves integrin switching and can help to explain the widespread accumulation of fibronectin at many organ basement membranes.
Summary
This review describes how direct visualization of the dynamic interactions of cells with different extracellular matrix microenvironments can provide novel insights into complex biological ...processes. Recent studies have moved characterization of cell migration and invasion from classical 2D culture systems into 1D and 3D model systems, revealing multiple differences in mechanisms of cell adhesion, migration and signalling—even though cells in 3D can still display prominent focal adhesions. Myosin II restrains cell migration speed in 2D culture but is often essential for effective 3D migration. 3D cell migration modes can switch between lamellipodial, lobopodial and/or amoeboid depending on the local matrix environment. For example, “nuclear piston” migration can be switched off by local proteolysis, and proteolytic invadopodia can be induced by a high density of fibrillar matrix. Particularly, complex remodelling of both extracellular matrix and tissues occurs during morphogenesis. Extracellular matrix supports self‐assembly of embryonic tissues, but it must also be locally actively remodelled. For example, surprisingly focal remodelling of the basement membrane occurs during branching morphogenesis—numerous tiny perforations generated by proteolysis and actomyosin contractility produce a microscopically porous, flexible basement membrane meshwork for tissue expansion. Cells extend highly active blebs or protrusions towards the surrounding mesenchyme through these perforations. Concurrently, the entire basement membrane undergoes translocation in a direction opposite to bud expansion. Underlying this slowly moving 2D basement membrane translocation are highly dynamic individual cell movements. We conclude this review by describing a variety of exciting research opportunities for discovering novel insights into cell‐matrix interactions.
Human-machine systems required a deep understanding of human behaviors. Most existing research on action recognition has focused on discriminating between different actions, however, the quality of ...executing an action has received little attention thus far. In this paper, we study the quality assessment of driving behaviors and present WiQ, a system to assess the quality of actions based on radio signals. This system includes three key components, a deep neural network based learning engine to extract the quality information from the changes of signal strength, a gradient-based method to detect the signal boundary for an individual action, and an activity-based fusion policy to improve the recognition performance in a noisy environment. By using the quality information, WiQ can differentiate a triple body status with an accuracy of 97%, whereas for identification among 15 drivers, the average accuracy is 88%. Our results show that, via dedicated analysis of radio signals, a fine-grained action characterization can be achieved, which can facilitate a large variety of applications, such as smart driving assistants.
Liu, J.; Xing, L.; Shao, C.; Li, S.; Huang, M.; Weng, J., and Fu, C., 2023. Update to the Quaternary stratigraphic division in Xiaoshao Plain, Zhejiang, China. Journal of Coastal Research, 39(5), ...984–997. Charlotte (North Carolina), ISSN 0749-0208. Establishing a reliable chronological framework of Quaternary sedimentary stratigraphy contributes to a more comprehensive understanding of the evolutionary patterns of sedimentary environments and predicts their trends. Local exploration standards are essential indicators in the construction of a chronological framework for Quaternary sedimentary stratigraphy. However, many of the local standards introduced today lack detailed field investigations and comprehensive and in-depth analyses of geological investigations in local areas and still need further improvement. For these areas, there are significant differences in understanding between different researchers, and the absence of appropriate and uniform local standards will lead to misjudgment of geological conditions and cause much inconvenience in the design, construction, and management of engineering and construction projects. On the basis of this, Xiaoshao Plain in Zhejiang Province, China serves as a research subject and samples were collected by drilling and coring. The Quaternary stratigraphy of Xiaoshao Plain is tentatively divided into nine major layers and 22 sublayers following the local standard of Zhejiang Province's Code for Geotechnical Engineering Investigation of Engineering Construction (DB33/1065-2009) introduced in 2009. The geological age of some of the strata in the area and changes in the depositional environment were further explored through accelerator mass spectrometry (AMS) 14C testing and microsomal paleontological fossil identification. Thus, the large stratigraphy of the Quaternary sedimentary strata of Xiaoshao Plain in the Zhejiang local standard is supplemented. Finally, in combination with the existing regional engineering geological survey report, the stratigraphic substratum of the area has been reclassified (the study divides it into 36 substrata). This study provides new ideas for the improvement of local standards for geological surveys and guidance for engineering construction development in Xiaoshao Plain.
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