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#34561309   // To Up

Beyond the hockey stick: Climate lessons from the Common Era.

More than two decades ago, my coauthors, Raymond Bradley and Malcolm Hughes, and I published the now iconic "hockey stick" curve. It was a simple graph, derived from large-scale networks of diverse climate proxy ("multiproxy") data such as tree rings, ice cores, corals, and lake sediments, that captured the unprecedented nature of the warming taking place today. It became a focal point in the debate over human-caused climate change and what to do about it. Yet, the apparent simplicity of the hockey stick curve betrays the dynamicism and complexity of the climate history of past centuries and how it can inform our understanding of human-caused climate change and its impacts. In this article, I discuss the lessons we can learn from studying paleoclimate records and climate model simulations of the "Common Era," the period of the past two millennia during which the "signal" of human-caused warming has risen dramatically from the background of natural variability.
Michael E Mann

2085 related Products with: Beyond the hockey stick: Climate lessons from the Common Era.

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#34560495   2021/09/11 To Up

Poplar tree (Populus balsamifera L.) as indicator of mercury emission from a point source.

The article provides original data on the ecological and geochemical characteristics of the distribution of Hg in the leaves and annual rings of balsam poplar (P. balsamifera L.) in the zone of influence of lithium production (Novosibirsk). In 2017 high Hg concentration (1300 ng/g) in the poplar leaves was recorded in the northeastern part of the city near the industrial facility of the lithium plant. The investigation showed a clear trend of increased Hg accumulation in the poplar leaves during the growing season. The maximum average Hg content was detected in the leaf litter in 2006 (1153-2425 ng/g). However, the average Hg content in the soil is 294 ng/g, which is significantly lower than the threshold limit value (2100 ng/g). Studies of changes in the content of Hg with the height of the crown of the tree revealed an increase in the upwind side of the emission source, the concentration of Hg in the leaves is on average 1.5 times higher than on the side of the "wind shadow". Hg in poplar leaves, leaf litter, and soils is mainly found in free and physically bonded forms - the most mobile, prone to increased migration, transformation and methylation under environmental conditions. According to the Hg content in the poplar cores, an increase in the Hg input near the source was established with the beginning of Li production - in the period 1967-1985 years (441 ng/g) with a subsequent decrease to 6 ng/g in 2000-2017.
D V Yusupov, E E Lyapina, E M Tursunalieva, N A Osipova, N V Baranovskaya

2820 related Products with: Poplar tree (Populus balsamifera L.) as indicator of mercury emission from a point source.

100ul50ul 100ul 100ul50ul 100ul 100ul 100ul100ug50ul50μl 100ul

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#34560225   2021/09/21 To Up

Assessing Dentists' Knowledge and Experience in Restoring Endodontically Treated Teeth Using Post & Cores.

The restoration of endodontically, heavily filled teeth has been a challenge for the dental profession for decades. The aims of this study were to investigate dentists' experience and knowledge in the use of post & core when restoring endodontically treated teeth.
K Shankla, R Sambrook, P Fine, R Blizard, A Leung

1981 related Products with: Assessing Dentists' Knowledge and Experience in Restoring Endodontically Treated Teeth Using Post & Cores.



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#34559969   2021/09/24 To Up

Core-Doped [(CdCo)S(SPh)] Clusters from a Self-Assembly Route.

The incorporation of substitutional Co impurities in [CdS(SPh)] (Cd) molecular clusters prepared by the self-assembly method where NaS is the sulfur precursor and a redox method where elemental S is the sulfur precursor is studied. The Co ions provide unique spectroscopic and chemical handles to monitor dopant speciation during cluster formation and determine what role, if any, other cluster species play during Cd cluster formation. In contrast to the redox method that produces exclusively surface-exchanged Co-doped Cd (Co:Cd), the preparation of Cd by the self-assembly method in the presence of Co ions results in Co incorporation at both the surface and core sites of the Cd cluster. Electrospray ionization mass spectrometry (ESI-MS) analysis of the dopant distribution for the self-assembly synthesis of Co:Cd is consistent with a near-Poissonian distribution for all nominal dopant concentrations albeit with reduced actual Co incorporation. At a nominal Co concentration of 50%, we observe incorporation of up to seven Co ions within the Cd self-assembled cluster compared to a maximum of only four Co dopants in the Cd redox clusters. The observation of up to seven Co dopants must involve substitution of at least three core sites within the Cd cluster. Electronic absorption spectra of the Co ligand field transition in the heavily doped Co:Cd clusters display clear deviation with the surface-doped Co-doped Cd clusters prepared by the redox method. We hypothesize that the coordination of Co and S ions in solution prior to cluster formation, which is possible only with the self-assembly method, is critical to the doping of Co ions within the Cd cores.
Jillian E Denhardt, Kevin R Kittilstved

1928 related Products with: Core-Doped [(CdCo)S(SPh)] Clusters from a Self-Assembly Route.

100 µg100ug Lyophilized100ug Lyophilized 0.1 mg 1 mg100 0.2 mg 1 mg100ug Lyophilized100 µg

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#34557737   2021/01/19 To Up

Small Molecular NIR-II Fluorophores for Cancer Phototheranostics.

Phototheranostics integrates deep-tissue imaging with phototherapy (containing photothermal therapy and photodynamic therapy), holding great promise in early diagnosis and precision treatment of cancers. Recently, second near-infrared (NIR-II) fluorescence imaging exhibits the merits of high accuracy and specificity, as well as real-time detection. Among the NIR-II fluorophores, organic small molecular fluorophores have shown superior properties in the biocompatibility, variable structure, and tunable emission wavelength than the inorganic NIR-II materials. What's more, some small molecular fluorophores also display excellent cytotoxicity when illuminated with the NIR laser. This review summarizes the progress of small molecular NIR-II fluorophores with different central cores for cancer phototheranostics in the past few years, focusing on the molecular structures and phototheranostic performances. Furthermore, challenges and prospects of future development toward clinical translation are discussed.
Hanming Dai, Qing Shen, Jinjun Shao, Wenjun Wang, Fan Gao, Xiaochen Dong

1222 related Products with: Small Molecular NIR-II Fluorophores for Cancer Phototheranostics.

20 ug 2x5L 1L

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#34557262   2021/09/01 To Up

Nd-Doped Lanthanum Oxychloride Nanocrystals as Nanothermometers.

The development of optical nanothermometers operating in the near-infrared (NIR) is of high relevance toward temperature measurements in biological systems. We propose herein the use of Nd-doped lanthanum oxychloride nanocrystals as an efficient system with intense photoluminescence under NIR irradiation in the first biological transparency window and emission in the second biological window with excellent emission stability over time under 808 nm excitation, regardless of Nd concentration, which can be considered as a particular strength of our system. Additionally, surface passivation through overgrowth of an inert LaOCl shell around optically active LaOCl/Nd cores was found to further enhance the photoluminescence intensity and also the lifetime of the 1066 nm, F to I transition, without affecting its (ratiometric) sensitivity toward temperature changes. As required for biological applications, we show that the obtained (initially hydrophobic) nanocrystals can be readily transferred into aqueous solvents with high, long-term stability, through either ligand exchange or encapsulation with an amphiphilic polymer.
Carlos Renero-Lecuna, Ada Herrero, Dorleta Jimenez de Aberasturi, Miriam Martínez-Flórez, Rafael Valiente, Mikhail Mychinko, Sara Bals, Luis M Liz-Marzán

1378 related Products with: Nd-Doped Lanthanum Oxychloride Nanocrystals as Nanothermometers.

100 μg 1KG1 kit1 kit100200 assays100 assays10 assays100ug Lyophilized50 mg

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#34556734   2021/09/23 To Up

Polycyclic aromatic hydrocarbons in permafrost peatlands.

The concentrations of 15 individual PAHs in 93 peat cores have been determined by using high-performance liquid chromatography methods. In the profile the qualitative and quantitative composition of PAHs was non-uniform estimated in a wide range: from 112 to 3673 ng/g with mean 1214 ± 794 ng/g. Among 15 identified individual PAHs, the main contribution to their total amount was made by heavy highly condensed PAHs in the Eastern European peat plateaus, in particular, 6-nuclear benzo[ghi]perylene (1021 ± 707 ng/g), whereas in West Siberian permafrost peatlands, light PAHs were dominating, mostly naphthalene and phenanthrene (211 ± 87 and 64 ± 25 ng/g, respectively). The grass-equisetum peat contained the maximum of heavy PAHs and the dwarf shrub-grass-the minimum. In grass-dwarf shrub, grass-moss and moss peat, the share of 2-nuclear PAHs was most significant: naphthalene and fluorene, as well as 6-nuclear benzo[ghi]perylene. The presence of benzo[ghi]perylene in the entire peat strata, including its permafrost layer, was a marker of the anaerobic conditions that persisted throughout the Holocene and they were necessary for the synthesis of this compound.
Alexander Pastukhov, Sergey Loiko, Dmitry Kaverin

2567 related Products with: Polycyclic aromatic hydrocarbons in permafrost peatlands.

2 Pieces/Box100 μg5mg100ug LyophilizedInhibitor100ug Lyophilized50ul100

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#34556238   2021/07/31 To Up

A terahertz time-domain super-resolution imaging method using a local-pixel graph neural network for biological products.

The low image acquisition speed of terahertz (THz) time-domain imaging systems limits their application in biological products analysis. In the current study, a local pixel graph neural network was built for THz time-domain imaging super-resolution. The method could be applied to the analysis of any heterogeneous biological products as it only required a small number of sample images for training and particularly it focused on THz feature frequencies. The graph network applied the Fourier transform to graphs extracted from low-resolution (LR) images bringing an invariance of rotation and flip for local pixels, and the network then learnt the relationship between the state of graphs and the corresponding pixels to be reconstructed. With wood cores and seeds as examples, the images of these samples were captured by a THz time-domain imaging system for training and analysed by the method, achieving the root mean square error (RMSE) of pixels of 0.0957 and 0.1061 for the wood core and seed images, respectively. In addition, the reconstructed high-resolution (HR) images, LR images and true HR images at several feature frequencies were also compared in the current study. Results indicated that the method could not only reconstruct the spatial details and the useful signals from high noise signals at high feature frequencies but could also operate super-resolution in both spatial and spectral aspects.
Tong Lei, Brian Tobin, Zihan Liu, Shu-Yi Yang, Da-Wen Sun

2606 related Products with: A terahertz time-domain super-resolution imaging method using a local-pixel graph neural network for biological products.

100μg100μg100Tests100μg 100 UG100tests100ul100ug200 purifications5 mg10ìg

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#34555912   // To Up

A Prosthetically Guided Technique for Cast Post-and-Core Fabrication.

Despite it being an older, conventional production method, the cast metal post and core is still often considered the best option for the restoration of severely damaged teeth. The direct technique for fabrication of cast post-and-core patterns, however, can pose challenges due to the inefficiencies and guesswork involved in creating an appropriate form and dimension for the core segment. This article presents an enhanced technique for cast post-and-core fabrication in reference to the desired dimensions of the final restoration. As the authors demonstrate, the procedure involves creation of an accurate and passive pattern of each post space. Bis-acrylic composite resin is then injected into a putty impression of the idealized wax-up and seated on the prepared post patterns. A preparation of the abutments is then performed by creating the cores according to the desired dimensions of the final restoration. The major advantages of this technique include a more efficient workflow and a reduction in the number of adjustments needed after insertion.
Jason D Lee, Mona Khan, Sang J Lee

1355 related Products with: A Prosthetically Guided Technique for Cast Post-and-Core Fabrication.



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