3,082 research outputs found
Response of Gaussian-modulated guided wave in aluminum: An analytical, numerical, and experimental study
The application of guided-wave ultrasonic testing in structural health monitoring has been widely accepted. Comprehensive experimental works have been performed in the past but their validation with possible analytical and numerical solutions still requires serious efforts. In this paper, behavior and detection of the Gaussian-modulated sinusoidal guided-wave pulse traveling in an aluminum plate are presented. An analytical solution is derived for sensing guided wave at a given distance from the actuator. This solution can predict the primary wave modes separately. Numerical analysis is also carried out in COMSOLÂź Multiphysics software. An experimental setup comprising piezoelectric transducers is used for the validation. Comparison of experimental results with those obtained from analytical and numerical solutions shows close agreement
Involvement of soluble proteins in growth and metabolic adjustments of drought-stressed Calligonum mongolicum seedlings under nitrogen addition
The planting of seedlings is the most effective measure for vegetation restoration. However, this practice is challenging in desert ecosystems where water and nutrients are scarce. Calligonum mongolicum is a sand-fixing pioneer shrub species, and its adaptive strategy for nitrogen (N) deposition and drought is poorly understood. Thus, in a pot experiment, we studied the impacts of four N levels (0, 3, 6, 9 gN·mâ2·yearâ1) under drought or a well-watered regime on multiple eco-physiological responses of 1-year-old C. mongolicum seedlings. Compared to well-watered conditions, drought considerably influenced seedling growth by impairing photosynthesis, osmolyte accumulation and activity of superoxide dismutase and enzymes related to N metabolism. Nitrogen addition improved the productivity of drought-stressed seedlings, as revealed by increased water use efficiency, enhanced superoxide dismutase and nitrite reductase activity and elevated N and phosphorus (P) levels in seedlings. Nevertheless, the addition of moderate to high levels of N (6â9 gN·mâ2·yearâ1) impaired net photosynthesis, osmolyte accumulation and nitrate reductase activity. N addition and water regimes did not markedly change the N:P ratios of aboveground parts; while more biomass and nutrients were allocated to fine roots to assimilate the insufficient resources. Soluble protein in assimilating shoots might play a vital role in adaptation to the desert environment. The response of C. mongolicum seedlings to N addtion and drought involved an interdependency between soluble protein and morphological, physiological and biochemical processes. These findings provide an important reference for vegetation restoration in arid lands under global change.Fil: Zhang, Z.. Chinese Academy of Sciences; RepĂșblica de China. Cele National Station of Observation and Research for Desert-Grassland Ecosystems; ChinaFil: Tariq, A.. Chinese Academy of Sciences; RepĂșblica de China. Cele National Station of Observation and Research for Desert-Grassland Ecosystems; ChinaFil: Zeng, F.. Chinese Academy of Sciences; RepĂșblica de China. Cele National Station of Observation and Research for Desert-Grassland Ecosystems; ChinaFil: Chai, X.. Chinese Academy of Sciences; RepĂșblica de China. Cele National Station of Observation and Research for Desert-Grassland Ecosystems; ChinaFil: Graciano, Corina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FisiologĂa Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de FisiologĂa Vegetal; Argentin
Sustainable digital economy and trade adjusted carbon emissions: Evidence from China's provincial data
The importance of the digital economy and trade adjusted emissions is of great importance to study, especially in case of China. Since China is the leading exporter of the world and achieving high economic growth consecutively for the last 2-3 decades, this study, unlike past studies, evaluates the importance of digital economy, exports, imports and gross domestic product on trade adjusted carbon emissions for China. This is the only study that incorporates the importance of digital economy on trade adjusted carbon emissions for provincial data of China. This study determines whether the digital economy is a viable source of green economy. Research and development will simply replace a physical resource, flows through energy and transportation networks? This question is answered by using updated data, especially for digital economy. This study uses panel data for the Chinese provinces to investigate the impact of the digital economy in limiting CO2 emissions, taking into account GDP, exports and imports as control variables. Using method of moments quantile regression, we find a negative impact of digital economy and exports on consumption-based carbon emissions. Moreover, we find that GDP, and imports amplify consumption-based carbon emissions. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Decoupled and Descattered Monopole MIMO Antenna Array with Orthogonal Radiation Patterns
This chapter introduces a novel design concept to reduce mutual coupling among closely-spaced antenna elements of a MIMO array. This design concept significantly reduces the complexity of traditional/existing design approaches such as metamaterials, defected ground plane structures, soft electromagnetic surfaces, parasitic elements, matching and decoupling networks using a simple, yet a novel design alternative. The approach is based on a planar single decoupling element, consisting of a rectangular metallic ring resonator printed on one face of an ungrounded substrate. The decoupling structure surrounds a two-element vertical monopole antenna array fed by a coplanar waveguide structure. The design is shown both by simulations and measurements to reduce the mutual coupling by at least 20 dB, maintain the impedance bandwidth over which S11, is less than â10 dB, and reduce the envelope correlation coefficient to below 0.001. The boresight of the far-field radiation patterns of the two vertical monopole wire antennas operating at 2.4 GHz and separated by 8 mm (λo/16), where λo is the free-space wavelength at 2.45 GHz, is shown to be orthogonal and inclined by 45° with respect to the horizontal (azimuthal) plane while maintaining the shape of the isolated single antenna element
Immunomodulatory Effects of Psyllium Extract on Helicobacter pylori Interaction With Gastric Epithelial Cells.
Natural plant product Psyllium has anti-inflammatory activity that can modulate the function of cytokines. We determined the effect of Psylliumhusk extract on interleukin (IL)-8 and NF-ÎșB secretion by gastric epithelial cells in response to Helicobacter pylori Human gastricadenocarcinoma cell line (AGS) cells were pretreated with Psyllium extract in different concentrations before H pylori infection. Cell culture supernatant was analyzed for IL-8 and NF-ÎșB by ELISA. RNA from cells was used for real-time polymerase chain reaction for messenger RNA expression of IL-8. Psyllium extract 5 and 10 ÎŒg/mL markedly (P \u3c .001) lowered basal IL-8 by 64.71% and 74.51%, respectively, and H pylori-stimulated IL-8 was also (P \u3c .001) lowered by 41.67% and 66.67%, respectively. Psyllium 5 and 10 ÎŒg/mL also reduced (P \u3c .0001) cagA-positive H pylori-induced IL-8 mRNA expression by 42.3% and 67.6%, respectively. Psyllium also reduced (P = .0001) NF-ÎșB in response to H pylori strains confirming its role as an anti-inflammatory agent
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Development and characterisation of semi-crystalline composite granules: the effect of particle chemistry and the electrostatic charging
This study investigated the surface of semi-crystalline composite granules produced via a novel mechano-chemical process and assessed the effect of electrostatic charging. Ibuprofen (IBU), a model drug with low solubility and known associated processing challenges was loaded in composite granules to improve its processibility and dissolution rates. Synthetic amorphous mesoporous magnesium alumina metasilicate (MAS) was co-processed with hydrophilic HPMC polymer in the presence of polyethylene glycol 2000 (PEG) and deionised water. The solid state analyses conducted by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) revealed the existence of semi-crystalline IBU in the complex composite structures. Dynamic vapour sorption (DVS) study showed the water sorption and desorption profiles of the manufactured composite granules as well as the effect of water on the solid-state stability of IBU in various formulations. Advanced surface analysis conducted via energy dispersive X-ray (EDS) revealed homogenous distribution of the drug/excipients on the surface of the granules while atomic force microscopy (AFM) complemented the findings. The electrostatic charge analysis showed variable charge property which is affected by the size of the particles/granules. As expected, the in vitro dissolution study showed about 5 fold increase in the release rates of IBU compared to that of the bulk drug. The mechano-chemical processing has been demonstrated as an efficient technique to develop semi-crystalline composite granules with enhanced dissolution rates of water insoluble drugs
Identification of avian Mycoplasma species in commercial broilers and layers with respiratory symptoms in Balochistan
Among many avian mycoplasmas, only the Mycoplasmas gallisepticum (MG) and Mycoplasmas synoviae (MS) are responsible for causing respiratory disease in commercial poultry. This study reported for the very first time the serological occurrence of M. gallisepticum and M. synoviae in blood samples (n = 600) from sixty flocks (n = 42 broiler and n = 18 layer flocks) with respiratory symptoms in Quetta, Pishin and Kuchlak districts of Balochistan, Pakistan. Sera were tested for MG and MS antibody responses by serum plate agglutination (SPA) test and by enzyme-linked immunosorbant assay (ELISA) Synbiotics kit. It was found that M. gallisepticum antibodies in broiler flocks detected by SPA and by ELISA tests were 10.47 and 19.76%, whereas M. synoviae were 7.86 and 11.19%, respectively. In layer flocks the MG and MS antibodies detected by SPA and ELISA were 19.44, 31.66 and 8.8, 25%, respectively. The overall antibodies of MG and MS in both broiler and layer flocks tested by SPA and ELISA was found to be 13.16, 23.33 and 8.16, 15.33%, respectively. In broiler and layer flocks the presence of antibodies against both M. gallisepticum and M. synoviae were found in tested flocks with respiratory symptoms. Further studies on prevalence and diagnosis of both the M. gallisepticum and M. synoviae in causing respiratory disease in commercial broilers and layers in Balochistan are required.Key words: Mycoplasma, broilers, serum plate agglutination, enzyme-linked immunosorbent assay
HIF-independent synthetic lethality between CDK4/6 inhibition and VHL loss across species
This is the author accepted manuscript. The final version is available from AAAS via the DOI in this recordData and materials availability: The full dataset of the dsRNA screen in Drosophila S2R+cells
is available at www.flyrnai.org/screensummary. All other data needed to evaluate the
conclusions in the paper are present in the paper or the Supplementary Materials.Inactivation of the VHL tumor suppressor gene is the signature initiating event in clear cell renal cell carcinoma (ccRCC), the most common form of kidney cancer, and causes the accumulation of hypoxia-inducible factor 2α (HIF-2α). HIF-2α inhibitors are effective in some ccRCC cases, but both de novo and acquired resistance have been observed in the laboratory and in the clinic. Here, we identified synthetic lethality between decreased activity of cyclin-dependent kinases 4 and 6 (CDK4/6) and VHL inactivation in two species (human and Drosophila) and across diverse human ccRCC cell lines in culture and xenografts. Although HIF-2α transcriptionally induced the CDK4/6 partner cyclin D1, HIF-2α was not required for the increased CDK4/6 requirement of VHLâ/â ccRCC cells. Accordingly, the antiproliferative effects of CDK4/6 inhibition were synergistic with HIF-2α inhibition in HIF-2αâdependent VHLâ/â ccRCC cells and not antagonistic with HIF-2α inhibition in HIF-2αâindependent cells. These findings support testing CDK4/6 inhibitors as treatments for ccRCC, alone and in combination with HIF-2α inhibitors.National Cancer InstituteDana-Farber Cancer InstituteHoward Hughes Medical InstituteNational Institute of General Medical Science
Minimum Atom-Bond Sum-Connectivity Index of Trees With a Fixed Order and/or Number of Pendent Vertices
Let be the degree of a vertex of a graph . The atom-bond
sum-connectivity (ABS) index of a graph is the sum of the numbers
over all edges of . This paper gives the
characterization of the graph possessing the minimum ABS index in the class of
all trees of a fixed number of pendent vertices; the star is the unique
extremal graph in the mentioned class of graphs. The problem of determining
graphs possessing the minimum ABS index in the class of all trees with
vertices and pendent vertices is also addressed; such extremal trees have
the maximum degree when , and the balanced double star is
the unique such extremal tree for the case .Comment: 20 pages, 4 figure
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