Search results for: Reactivity
#33080558 2020/10/13 To Up
Sources of nitric oxide during the outbreak of Ulva prolifera in coastal waters of the Yellow Sea off Qingdao.Nitric oxide (NO) has been identified as a key physiological modulator and signaling molecule in animals and plants. However, due to its high reactivity, our knowledge of its production and consumption pathways in the ocean remain limited. Laboratory experiments showed that Ulva prolifera can produce NO, producing as much as 0.44 ± 0.04 nmol h g. During the growth period, U. prolifera released NO, but during the decay period NO was absorbed by U. prolifera and bacteria. Furthermore, field investigations examined NO concentrations in the coastal waters of the Yellow Sea off Qingdao, where the U. prolifera green tide occurred in summer 2018. The average concentrations of NO in the surface seawater were 70.2 ± 38.2 pmol L and 18.9 ± 10.3 pmol L in the late- and after-bloom periods, respectively. NO release by U. prolifera was the primary contributor to the high NO concentrations during the late-bloom period. The study area was a net source of NO to the atmosphere during the study period, with average NO sea-air fluxes from the Qingdao coastal waters being 1.5 × 10 mol m s and 0.4 × 10 mol m s in the late- and after-bloom periods, respectively. This study concluded that the coastal waters of the Yellow Sea off Qingdao contributed more NO to the atmosphere during the bloom of U. prolifera than afterward.
Ke-Ke Wang, Ye Tian, Pei-Feng Li, Chun-Ying Liu, Gui-Peng Yang
1357 related Products with: Sources of nitric oxide during the outbreak of Ulva prolifera in coastal waters of the Yellow Sea off Qingdao.1 5 G96tests100
#33080460 2020/09/18 To Up
Lymph-directed nitric oxide increases immune cell access to lymph-borne nanoscale solutes.Lymph nodes (LNs) are immune organs housing high concentrations of lymphocytes, making them critical targets for therapeutic immunomodulation in a wide variety of diseases. While there is great interest in targeted drug delivery to LNs, many nanoscale drug delivery carriers have limited access to parenchymal resident immune cells compared to small molecules, limiting their efficacy. Nitric oxide (NO) is a potent regulator of vascular and lymphatic transport and a promising candidate for modulating nanocarrier access to LNs, but its lymphatic accumulation is limited by its low molecular weight and high reactivity. In this work, we employ S-nitrosated nanoparticles (SNO-NP), a lymphatic-targeted delivery system for controlled NO release, to investigate the effect of NO application on molecule accumulation and distribution within the LN. We evaluated the LN accumulation, spatial distribution, and cellular distribution of a panel of fluorescent tracers after intradermal administration alongside SNO-NP or a small molecule NO donor. While SNO-NP did not alter total tracer accumulation in draining lymph nodes (dLNs) or affect active cellular transport of large molecules from the injection site, its application enhanced the penetration of nanoscale 30 nm dextrans into the LN and their subsequent uptake by LN-resident lymphocytes, while nontargeted NO delivery did not. These results further extended to a peptide-conjugated NP drug delivery system, which showed enhanced uptake by B cells and dendritic cells when administered alongside SNO-NP. Together, these results highlight the utility of LN-targeted NO application for the enhancement of nanocarrier access to therapeutically relevant LN-resident immune cells, making NO a potentially useful tool for improving LN drug delivery and immune responses.
Lauren F Sestito, Susan N Thomas
2557 related Products with: Lymph-directed nitric oxide increases immune cell access to lymph-borne nanoscale solutes.100 2 x 96 well plate100
#33080288 2020/10/17 To Up
Psychophysiological correlates of anxious apprehension: Trait worry is associated with startle response to threat.Worry is a form of repetitive negative thought that is closely associated with anxiety disorders. Worry has been described as anxious apprehension and conceptualized as reflecting heightened anticipation of potentially threatening future events. However, it is unclear whether people who tend to worry show heightened physiological reactivity when anticipating threat, especially if the threat is uncertain. In the current study, community participants (n = 52) completed a threat anticipation task featuring uncertain threat, certain threat, and safety while the startle response to auditory probes was measured. Self-reported tendency to worry was assessed using the Penn State Worry Questionnaire, and anxiety disorder status was assessed via a clinical interview. A repeated-measures general linear model showed a main effect of threat level on the startle response, as well as a significant three-way interaction among threat level, worry, and anxiety disorder status. Follow-up tests showed that higher worry was associated with blunted startle responses to threat but particularly to uncertain threat among participants with a history of anxiety disorders. Worry did not moderate startle responding in participants without a history of anxiety disorders. These results indicate that psychophysiological correlates of worry depend on clinical status and suggest that trait worry is associated with physiological blunting to threat in individuals with a history of anxiety disorders, particularly when threat is uncertain. Implications for theoretical models of worry are discussed.
Ashleigh V Rutherford, Ema Tanovic, Daniel E Bradford, Jutta Joormann
1574 related Products with: Psychophysiological correlates of anxious apprehension: Trait worry is associated with startle response to threat.200 ug200 ug100 ug200 ug100 ug200 ug1 g100 ug1 mg200 ug100 ug200 ug
#33080137 2020/10/20 To Up
Cobalt Phosphide Nanoflake-Induced Flower-like Sulfur for High Redox Kinetics and Fast Ion Transfer in Lithium-Sulfur Batteries.S
Congyu Qi, Zheng Li, Changzhi Sun, Chunhua Chen, Jun Jin, Zhaoyin Wen
1060 related Products with: Cobalt Phosphide Nanoflake-Induced Flower-like Sulfur for High Redox Kinetics and Fast Ion Transfer in Lithium-Sulfur Batteries.4 Arrays/Slide50 ul2 Pieces/Box4 Membranes/Box2 Pieces/Box4 Membranes/Box4 Arrays/Slide400Tests
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#33079531 2020/10/20 To Up
Efficient Synthesis of Structured Phospholipids Containing Short-Chain Fatty Acids over a Sulfonated Zn-SBA-15 Catalyst.Catalytic production of structured phospholipids (SPLs) containing short-chain fatty acids (SCFAs) in an efficient heterogeneous manner is of great importance from the standpoint of food engineering. Herein, a bifunctionalized sulfonated Zn-SBA-15 catalyst was studied for SPL synthesis through interesterification of soybean lecithin with ethyl propionate or methyl butyrate. Various characterization techniques such as pyridine Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy were conducted to determine the physicochemical properties, so as to build the possible structure-reactivity relationship of the catalyst. In screening tests with commercial Amberlyst-15 or other SBA-15-type materials, the as-prepared sample showed promising catalytic performance probably owing to its mesoporous structure and cooperative role of Brönsted and Lewis acid sites. Notably, the sample was easily separated and recycled without obvious deactivation. In general, the investigated catalyst was regarded as one of the promising alternatives to otherwise expensive biocatalysts for SCFA-containing SPL production.
Jianghua Zhang, Ke Cheng, Hongyan Li, Fawen Yin, Qiaoe Wang, Li Cui, Shasha Yang, Jinggang Nie, Dayong Zhou, Beiwei Zhu
2680 related Products with: Efficient Synthesis of Structured Phospholipids Containing Short-Chain Fatty Acids over a Sulfonated Zn-SBA-15 Catalyst.1,000 tests10 100ug100ug100ug5 mg1001 g50 ug100 mg 1 G
#33078936 2020/10/20 To Up
Chemical Activation of Water Molecule by Collision with Spin-Orbit-State-Selected Vanadium Cation: Quantum-Electronic-State Control of Chemical Reactivity.We have obtained absolute integral cross sections (σ's) for the reactions of spin-orbit-state-selected vanadium cations, V[aD( = 0, 2), aF( = 1, 2), and aF( = 2, 3)], with a water molecule (HO) in the center-of-mass collision energy range = 0.1-10.0 eV. On the basis of these state-selected σ curves (σ versus plots) observed, three reaction product channels, VO + H, VH + OH, and VOH + H, from the V + HO reaction are unambiguously identified. Contrary to the previous guided ion beam study of the V(aD) + DO reaction, we have observed the formation of the VO + H channel from the V(aD) + HO ground reactant state at low 's (<3.0 eV). No spin-orbit -state dependences for the σ curves of individual electronic states are discernible, indicating that spin-orbit interactions are weak with little effect on chemical reactivity of the titled reaction. For the three product channels identified, the triplet σ(aF) values are overwhelmingly higher than the quintet σ(aD) and σ(aF) values, showing that the reaction is governed by a "weak quintet-triplet spin crossing" mechanism, favoring the conservation of total electron spins. The σ curves for exothermic product channels are found to exhibit a rapid decreasing profile as is increased, an observation consistent with the prediction of the charge-dipole and induced-dipole orbiting model. This experiment shows that the V + HO reaction can be controlled effectively to produce predominantly the VO + H channel via the V(aF) + HO reaction at low 's (≤0.1 eV) and that the ion-molecule reaction dynamics can be altered readily by selecting the electronic state of V cation. On the basis of the measured thresholds for the σ(aD, aF, and aF: VH) and σ(aD, aF, and aF: VOH) curves, we have deduced upper bound values of 2.6 ± 0.2 and 4.3 ± 0.3 eV for the 0 K bond dissociation energies, (V-H) and (V-OH), respectively. After correcting for the kinetic energy distribution resulting from the Doppler broadening effect of the HO molecule, we obtain (V-H) = 2.2 ± 0.2 eV and (V-OH) = 4.0 ± 0.3 eV, which are in agreement with determinations obtained by σ curve simulations.
Yuntao Xu, Yih-Chung Chang, Matthew Parziale, Anna Wannenmacher, Cheuk-Yiu Ng
2902 related Products with: Chemical Activation of Water Molecule by Collision with Spin-Orbit-State-Selected Vanadium Cation: Quantum-Electronic-State Control of Chemical Reactivity.100ug Lyophilized1ml1 g1 ml500Tests 5 G 50 UG100ug Lyophilized 50 UG
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#33078769 2020/10/20 To Up
Applications of diazaphospholene hydrides in chemical catalysis.Diazaphospholenes have recently emerged as main-group hydride transfer catalysts. This review will briefly summarize the common structural variants of diazaphospholenes, and the properties that make them superb hydride transfer catalysts, followed by a critical examination of the various preparative routes toward diazaphospholenes. Finally, an in-depth examination of the reactivity of diazaphospholenes in contemporary catalysis, including asymmetric catalysis will be undertaken.
Alexander W H Speed1 ml100 100 1000100 μg100ug Lyophilized100 μg1 g1 Set
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#33078501 2020/10/20 To Up
Cangrelor PK / PD Analysis in Post-Operative Neonatal Cardiac Patients at Risk for Thrombosis.Systemic-to-pulmonary artery shunt thrombosis is a significant cause of early postoperative mortality in neonates after palliation of congenital heart disease (CHD). In the context of thromboprophylaxis, an optimal therapeutic strategy has yet to be established prior to aspirin administration. Cangrelor, a fast-acting, reversible P2Y inhibitor, may fill this unmet need.
Diana Vargas, Hairu Zhou, Xinren Yu, Scott Diamond, Justin Yeh, Vivekanand Allada, Ganga Krishnamurthy, Mary Price, Beverly Allen, James Alexander, Joseph Schmidhofer, Jacqueline Kreutzer, Julie Vincent, Victor Morell, Emile Bacha, Thomas Diacovo
2865 related Products with: Cangrelor PK / PD Analysis in Post-Operative Neonatal Cardiac Patients at Risk for Thrombosis.100 μg1 Set1 Set0.1mg1 Set 5 G20 1 Set1 Set100ul1 Set
#33077946 2020/10/19 To Up
Modifying macrophages at the periphery has the capacity to change microglial reactivity and to extend ALS survival.Microglia and peripheral macrophages have both been implicated in amyotrophic lateral sclerosis (ALS), although their respective roles have yet to be determined. We now show that macrophages along peripheral motor neuron axons in mouse models and patients with ALS react to neurodegeneration. In ALS mice, peripheral myeloid cell infiltration into the spinal cord was limited and depended on disease duration. Targeted gene modulation of the reactive oxygen species pathway in peripheral myeloid cells of ALS mice, using cell replacement, reduced both peripheral macrophage and microglial activation, delayed symptoms and increased survival. Transcriptomics revealed that sciatic nerve macrophages and microglia reacted differently to neurodegeneration, with abrupt temporal changes in macrophages and progressive, unidirectional activation in microglia. Modifying peripheral macrophages suppressed proinflammatory microglial responses, with a shift toward neuronal support. Thus, modifying macrophages at the periphery has the capacity to influence disease progression and may be of therapeutic value for ALS.
Aude Chiot, Sakina Zaïdi, Charlène Iltis, Matthieu Ribon, Félix Berriat, Lorenzo Schiaffino, Ariane Jolly, Pierre de la Grange, Michel Mallat, Delphine Bohl, Stéphanie Millecamps, Danielle Seilhean, Christian S Lobsiger, Séverine Boillée
2004 related Products with: Modifying macrophages at the periphery has the capacity to change microglial reactivity and to extend ALS survival.100 assays100 assays50 µg96 100ul1 kit(96 Wells)5 mg100 IU
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