6,527 research outputs found
Evaluation of analgesic, anti-inflammatoryand antipyretic activities of the ethanol extract from Speranskia tuberculate
Background: Speranskia tuberculata (Bunge) Baill, has been used to prevent and treat many diseases in Chinese folk medicine, nevertheless, few investigations had been reported.Materials and Methods: Animals were orally administered STE at the doses of 125, 250, 500 mg/kg. The analgesic effect was estimated in mice by hot-plate test and the acetic acid-induced writhing test. The anti-inflammatory effect was assessed using rat paw edema model elicited by fresh egg white and the mouse ear edema model caused by dimethylbenzene. The antipyretic effect was determined using the lipopolysaccharide (LPS)-induced rat fever model. In addition, the acute oral toxicity of STE was studied.Results: STE significantly and dose-dependently reduced the number of writhing responses in mice, prolonged reaction time of mice against heat stimulation, depressed egg white-induced paw edema in rats and the dimethylbenzene-caused ear edema in mice, but did not alleviate LPS-induced pyrexia in rats. No death of mice was observed when orally administered STE up to 52.8 g/kg (approximately 2080 times of clinical dose used).Conclusion: STE possesses evident analgesic and anti-inflammatory activities, but has no antipyretic effect. Furthermore STE has a favorable safety. These findings support the applications of Speranskia tuberculata as an analgesic and anti-inflammatory drug in folk medicine.Key Words: Herb, pain, inflammation, Pyrexia, Safet
Linear Confinement for Mesons and Nucleons in AdS/QCD
By using a new parametrization of the dilaton field and including a cubic
term in the bulk scalar potential, we realize linear confinement in both meson
and nucleon sectors within the framework of soft-wall AdS/QCD. At the same time
this model also correctly incorporate chiral symmetry breaking. We compare our
resulting mass spectra with experimental data and find good agreement between
them.Comment: 14 pages, published version in JHE
Elemental distribution within the long-period stacking ordered structure in a Mg-Gd-Zn-Mn alloy
High angle annular dark field scanning transmission electron microscope imaging and electron energy loss spectroscopy was used to elucidate the elemental distribution (Gd, Zn, Mn) within the long-period stacking ordered (LPSO) structure in a Mg-15Gd-0.8Zn-0.8Mn (wt%) alloy. While Gd and Zn enrichment was observed within the LPSO structure, no significant enrichment in Mn was observed. After averaging over a large region, a very weak Mn signal was resolved but no significant variations in Mn signal were observed over this region, suggesting that Mn is indeed present. These results provide useful information to support the future development of high performance Mg alloys
Phase-transition induced giant negative electrocaloric effect in a lead-free relaxor ferroelectric thin film
The electrocaloric (EC) effect has been widely investigated during the past decade due to the potential applications in commercial solid state refrigeration devices. The positive EC effect in lead-based materials has been significantly enhanced from 12 K to 40 K since it is observed in 2006, but the negative EC effect still stays at a very low level of about −10 K, which limits further enhancement of cooling efficiency, especially when we attempt to combine both negative and positive EC effect in one cooling cycle. Due to the toxicity of lead, lead-free materials are always sought after to replace lead-containing materials. In this study, a giant negative EC effect (maximum ΔT ∼ −42.5 K) comparable to the best positive EC effects reported so far is demonstrated for 0.5(Ba0.8Ca0.2)TiO3–0.5Bi(Mg0.5Ti0.5)O3 lead-free relaxor ferroelectric thin films prepared by using a sol–gel method. An electric-field induced structural phase transition (nanoscale tetragonal and orthorhombic to rhombohedral) along the out-of-plane [111] direction plays a key role in developing the giant negative EC effect. This breakthrough will pave the way for practical applications of next-generation refrigeration devices with high cooling efficiency in one cycle by utilizing and combining both the giant negative and positive EC effects
Global high-resolution drought indices for 1981-2022
Droughts are among the most complex and devastating natural hazards globally. High-resolution datasets of drought metrics are essential for monitoring and quantifying the severity, duration, frequency, and spatial extent of droughts at regional and particularly local scales. However, current global drought indices are available only at a coarser spatial resolution (>50 km). To fill this gap, we developed four high-resolution (5 km) gridded drought records based on the standardized precipitation evaporation index (SPEI) covering the period 1981–2022. These multi-scale (1–48 months) SPEI indices are computed based on monthly precipitation (P) from the Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS, version 2) and Multi-Source Weighted-Ensemble Precipitation (MSWEP, version 2.8), and potential evapotranspiration (PET) from the Global Land Evaporation Amsterdam Model (GLEAM, version 3.7a) and hourly Potential Evapotranspiration (hPET). We generated four SPEI records based on all possible combinations of P and PET datasets: CHIRPS_GLEAM, CHIRPS_hPET, MSWEP_GLEAM, and MSWEP_hPET. These drought records were evaluated globally and exhibited excellent agreement with observation-based estimates of SPEI, root zone soil moisture, and vegetation health indices. The newly developed high-resolution datasets provide more detailed local information and can be used to assess drought severity for particular periods and regions and to determine global, regional, and local trends, thereby supporting the development of site-specific adaptation measures. These datasets are publicly available at the Centre for Environmental Data Analysis (CEDA; https://doi.org/10.5285/ac43da11867243a1bb414e1637802dec) (Gebrechorkos et al., 2023)
Double In Situ Approach for the Preparation of Polymer Nanocomposite with Multi-functionality
A novel one-step synthetic route, the double in situ approach, is used to produce both TiO2nanoparticles and polymer (PET), and simultaneously forming a nanocomposite with multi-functionality. The method uses the release of water during esterification to hydrolyze titanium (IV) butoxide (Ti(OBu)4) forming nano-TiO2in the polymerization vessel. This new approach is of general significance in the preparation of polymer nanocomposites, and will lead to a new route in the synthesis of multi-functional polymer nanocomposites
In-Vivo Biodistribution and Safety of 99mTc-LLP2A-HYNIC in Canine Non-Hodgkin Lymphoma
Theranostic agents are critical for improving the diagnosis and treatment of non-Hodgkin Lymphoma (NHL). The peptidomimetic LLP2A is a novel peptide receptor radiotherapy candidate for treating NHL that expresses the activated α4β1 integrin. Tumor-bearing dogs are an excellent model of human NHL with similar clinical characteristics, behavior, and compressed clinical course. Canine in vivo imaging studies will provide valuable biodistribution and affinity information that reflects a diverse clinical population of lymphoma. This may also help to determine potential dose-limiting radiotoxicity to organs in human clinical trials. To validate this construct in a naturally occurring model of NHL, we performed in-vivo molecular targeted imaging and biodistribution in 3 normal dogs and 5 NHL bearing dogs. 99mTc-LLP2A-HYNIC-PEG and 99mTc-LLP2A-HYNIC were successfully synthesized and had very good labeling efficiency and radiochemical purity. 99mTc-LLP2A-HYNIC and 99mTc-LLP2A-HYNIC-PEG had biodistribution in keeping with their molecular size, with 99mTc-LLP2A-HYNIC-PEG remaining longer in the circulation, having higher tissue uptake, and having more activity in the liver compared to 99mTc-LLP2A-HYNIC. 99mTc-LLP2A-HYNIC was mainly eliminated through the kidneys with some residual activity. Radioactivity was reduced to near-background levels at 6 hours after injection. In NHL dogs, tumor showed moderately increased activity over background, with tumor activity in B-cell lymphoma dogs decreasing after chemotherapy. This compound is promising in the development of targeted drug-delivery radiopharmaceuticals and may contribute to translational work in people affected by non-Hodgkin lymphoma
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From Haloes to Galaxies. II. The Fundamental Relations in Star Formation and Quenching
Star formation and quenching are two of the most important processes in
galaxy formation and evolution. We explore in the local Universe the
interrelationships among key integrated galaxy properties, including stellar
mass , star formation rate (SFR), specific SFR (sSFR), molecular gas mass
, star formation efficiency (SFE) of the molecular gas and
molecular gas to stellar mass ratio . We aim to identify the most
fundamental scaling relations among these key galaxy properties and their
interrelationships. We show the integrated -SFR, SFR- and
- relation can be simply transformed from the -sSFR,
SFE- and SFE-sSFR relation, respectively. The transformation, in
principle, can increase or decrease the scatter of each relation.
Interestingly, we find the latter three relations all have significantly
smaller scatter than the former three corresponding relations. We show the
probability to achieve the observed small scatter by accident is extremely
close to zero. This suggests that the smaller scatters of the latter three
relations are driven by a more fundamental physical connection among these
quantities. We then show the large scatters in the former relations are due to
their systematic dependence on other galaxy properties, and on star formation
and quenching process. We propose the sSFR--SFE relation as the
Fundamental Formation Relation (FFR), which governs the star formation and
quenching process, and provides a simple framework to study galaxy evolution.
Other scaling relations, including integrated Kennicutt-Schmidt law,
star-forming main sequence and molecular gas main sequence, can all be derived
from the FFR.STFC
ER
Local Optical Probe of Motion and Stress in a multilayer graphene NEMS
Nanoelectromechanical systems (NEMSs) are emerging nanoscale elements at the
crossroads between mechanics, optics and electronics, with significant
potential for actuation and sensing applications. The reduction of dimensions
compared to their micronic counterparts brings new effects including
sensitivity to very low mass, resonant frequencies in the radiofrequency range,
mechanical non-linearities and observation of quantum mechanical effects. An
important issue of NEMS is the understanding of fundamental physical properties
conditioning dissipation mechanisms, known to limit mechanical quality factors
and to induce aging due to material degradation. There is a need for detection
methods tailored for these systems which allow probing motion and stress at the
nanometer scale. Here, we show a non-invasive local optical probe for the
quantitative measurement of motion and stress within a multilayer graphene NEMS
provided by a combination of Fizeau interferences, Raman spectroscopy and
electrostatically actuated mirror. Interferometry provides a calibrated
measurement of the motion, resulting from an actuation ranging from a
quasi-static load up to the mechanical resonance while Raman spectroscopy
allows a purely spectral detection of mechanical resonance at the nanoscale.
Such spectroscopic detection reveals the coupling between a strained
nano-resonator and the energy of an inelastically scattered photon, and thus
offers a new approach for optomechanics
From Haloes to Galaxies. III. The Gas Cycle of Local Galaxy Populations
In Dou et al. (2021), we introduced the Fundamental Formation Relation (FFR), a tight relation between specific SFR (sSFR), H2 star formation efficiency (SFEH2 ), and the ratio of H2 to stellar mass. Here we show that atomic gas H i does not follow a similar FFR as H2. The relation between SFEHI and sSFR shows significant scatter and strong systematic dependence on all of the key galaxy properties that we have explored. The dramatic difference between H i and H2 indicates that different processes (e.g., quenching by different mechanisms) may have very different effects on the H i in different galaxies and hence produce different SFEHI-sSFR relations, while the SFEH2 -sSFR relation remains unaffected. The facts that SFEH2 -sSFR relation is independent of other key galaxy properties, and that sSFR is directly related to the cosmic time and acts as the cosmic clock, make it natural and very simple to study how different galaxy populations (with different properties and undergoing different processes) evolve on the same SFEH2 -sSFR ∼ t relation. In the gas regulator model (GRM), the evolution of a galaxy on the SFEH2 -sSFR(t) relation is uniquely set by a single mass-loading parameter λnet,H2 . This simplicity allows us to accurately derive the H2 supply and removal rates of the local galaxy populations with different stellar masses, from star-forming galaxies to the galaxies in the process of being quenched. This combination of FFR and GRM, together with the stellar metallicity requirement, provide a new powerful tool to study galaxy formation and evolution.ERC
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