Optimization of the longitudinal-torsional ultrasonic step-like horn design for milling tool applications via the tool load account

Ultrasonic horns are used in the ultrasonic-assisted milling and cutting tools. However, the interaction with tool end vibrations deteriorates the horn performance. In this study, the amplification coefficients and vibration node locations of an ultrasonic horn were determined via the 1D wave theory and optimized by the tool load effect account. By arranging spiral grooves at the straight part of the ultrasonic horn, a longitudinal-torsional modal converter was introduced. This made it possible to convert longitudinal vibrations into longitudinal-torsional coupled ones by the superposition of incident and reflected longitudinal waves with reflected transverse ones at grooves. Orthogonal L9 (33) tests with parameters of spiral grooves as variables were designed and conducted, and longitudinal-torsional ratios (LTR) of the milling tool end under different conditions were assessed using the commercial ANSYS software package. The in-depth analysis of simulation results implies that the LTR values are controlled by the following influence factors in the decreasing order: helical angle, number of grooves, and groove width. Single-factor tests indicate that LTR exhibits an initial drop and a further rise with the helical angle, attaining its minimal value at 30°; it drops with the number of grooves n, and remains practically unchanged with the groove width variation. Finally, the vibration tests of the proposed horn with the optimized parameters corroborated its feasibility and demonstrated its excellent performance in the ultrasonic-assisted milling tool application

In-silico design of novel 4-aminoquinolinyl analogs as potential anti-malaria agents using quantitative structure– activity relationships and ADMET approach

Purpose: To design and screen for potential anti-malaria agents based on a series of 4-aminoquinolinyl analogues.Methods: Molecular fingerprint analysis was used for molecular partitioning of training and test sets. Acquired training sets were used for CoMFA and CoMSIA model construction after good alignment was achieved. Partial least squares analysis combined with external validation were used for  model evaluation. Deep analysis of acquired contour maps was performed to summarize the substituent property requirements for further rational molecular design. Using the chosen models, activity prediction and subsequent ADMET investigation were performed to discover novel designed  compounds with the desired properties.Results: Three different set partitions for model establishment were obtained using fingerprint-based selection. Partition 02 offered an optimal CoMFA model (r2 = 0.964, q2 = 0.605 and r2pred = 0.6362) and the best CoMSIA model (r2 = 0.955, q2 = 0.585 and r2 pred = 0.6403). Based on contour map analysis, a series of compounds were designed for activity prediction. Two of the compounds (wmx09, wmx25) were chosen for their ideal predicted biological activities. Subsequent ADMET investigation indicated that these compoundss have acceptable drug-like characteristics.Conclusion: The screening reveals that compounds wmx09 and wmx25 have strong potential as antimalaria agents. Keywords: Malaria, 4-Aminoquinolinyl, Molecular fingerprint, QSAR, ADME

Excessive Accumulation of Chinese Fir Litter Inhibits Its Own Seedling Emergence and Early Growth—A Greenhouse Perspective

Litter accumulation can strongly influence plants’ natural regeneration via both physical and chemical mechanisms, but the relative influence of each mechanism on seedling establishment remains to be elucidated. Chinese fir (Cunninghamia lanceolata) is one of the most important commercial plantations in southern China, but its natural regeneration is poor, possibly due to its thick leaf litter accumulation. We used natural and plastic litter to study the effects of Chinese fir litter on its own seedling emergence and early growth, as well as to assess whether the effect is physical or chemical in nature. Results showed that high litter amount (800 g·m−2) significantly reduced seedling emergence and the survival rate for both natural and plastic litter. Low litter amount (200 g·m−2) exerted a slightly positive effect on root mass, leaf mass, and total mass, while high litter amount significantly inhibited root mass, leaf mass, and total mass for both natural and plastic litter. Root-mass ratio was significantly lower, and leaf-mass ratio was significantly greater under high litter cover than under control for both natural and plastic litter. Although the root/shoot ratio decreased with increasing litter amount, such effect was only significant for high litter treatment for both natural and plastic litter. Seedling robustness (aboveground biomass divided by seedling height) decreased with increasing litter amount, with high litter treatment generating the least robust seedlings. Because plastic and natural litter did not differ in their effects on seedling emergence and growth, the litter layer’s short-term influence is primarily physical. These data indicated that as litter cover increased, the initial slightly positive effects on seedling emergence and early growth could shift to inhibitory effects. Furthermore, to penetrate the thick litter layer, Chinese fir seedlings allocated more resources towards stems and aboveground growth at the expense of their roots. This study provided experimental evidence of litter amount as a key ecological factor affecting seedling development and subsequent natural regeneration of Chinese fir

Therapeutic Effects of Water Extract of Arisaema Erubescens Tubers on Type II Collagen-induced Arthritis in Rats

Purpose: To investigate the anti-arthritic activity of the water extract of Rhizoma Arisaematis (WERA) using collagen II (CII)-induced arthritis (CIA) rat model.Methods: CIA was induced in male Sprague-Dawley rat by intra dermal injection of bovine collagen type II (C II) in Freund’s complete adjuvant (cFA). The rats were treated daily for 21 consecutive days with WERA at doses of 100, 200, and 400 mg/kg. Methotrexate (MTX) was used as positive control, and administered at a dose of 3 mg/kg intraperitoneally in two-weekly cycles for 3 weeks. Severity of arthritis was evaluated by arthritic scores, including paw swelling, arthritic score, body weight, thymus index and spleen index. The levels of IL-1β, IL-6, IL-10 and TNF-α in serum were also measured.Results: The results revealed that WERA significantly inhibited paw edema (p-value < 0.01), decreased arthritis scores (p-value < 0.01) and spleen index (p-value < 0.05), and alleviated the weight loss of CIA rats. Furthermore, the pro-inflammatory cytokines of TNF-α (19.3%, 60.5% and 73.9%, respectively), IL- 1β (7.9%, 41.1% and 52.7%, respectively) and IL-6 (26.6%, 48.0% and 72.2%, respectively) were remarkably attenuated in serum of all WERA treated rats, however, IL-10 (72.4% and 39.1%, respectively) was markedly increased at doses of 200 and 400 mg/kg of WERA.Conclusion: The results demonstrate that WERA exerts therapeutic effects in collagen--induced arthritis of rats by decreasing the levels of TNF-α, IL-1β, IL-6 and IL-10 in serum, and therefore may be an effective candidate drug for the treatment of human rheumatoid arthritis.Keywords: Rhizoma Arisaematis, Rheumatoid arthritis, Inflammatory, Cytokines, Freund’s complete adjuvan

Effect of Arisaema erubescens (Wall) Schott rhizome extract on rheumatoid arthritis

Purpose: To investigate the anti-arthritic activity of the water extract of Rhizoma Arisaematis (WERA) using a collagen II -induced arthritis (CIA) rat model.Methods: CIA was induced in male Sprague-Dawley rats by intradermal injection of bovine collagen II in Complete Freund’s Adjuvant. The rats were treated with daily oral doses of WERA (100, 200, and 400 mg/kg) for 21 consecutive days. Methotrexate (MTX, 3 mg/kg), used as a positive control, was administered orally 2 times/week for 3 weeks. The severity of arthritis was evaluated using indices of paw swelling, arthritic score, body weight, thymus index, and spleen index. In addition, the serum levels of IL-1β, IL-6, IL-10, and TNF-α were measured.Results: All doses of WERA significantly inhibited paw edema (p < 0.01), decreased arthritis scores (p < 0.01) and spleen index (p < 0.05), and alleviated the weight loss associated with CIA in rats. Furthermore, TNF-α, IL-1β, and IL-6 serum levels were significantly decreased (p < 0.05) by all doses of WERA. By contrast, IL-10 serum levels were markedly increased (p < 0.05).Conclusion: WERA exerts therapeutic effects in CIA in rats by decreasing the serum levels of TNF-α, IL-1β, IL-6 and IL-10, suggesting WERA may be an effective candidate drug for treating human rheumatoid arthritis.Keywords: Rhizoma Arisaematis, Rheumatoid arthritis, Inflammatory, Cytokines, Freund’s complete adjuvan

catena-Poly[[[tetra­aqua­cobalt(II)]-μ-4,4′-bipyridine-κ2 N:N′] 2-[4-(2-carboxyl­ato­eth­yl)phen­oxy]acetate]

In the title complex, {[Co(C10H8N2)(H2O)4](C11H10O5)}n, the unique CoII ion lies on an inversion center and is coordinated by two N atoms from two 4,4′-bipyridine ligands and four O atoms from four water mol­ecules in a slightly distorted octa­hedral coordination geometry. The 4,4′-bipyridine ligands bridge CoII ions into a one-dimensional chain structure. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link cations and anions into a three-dimensional network. The dianions are completely disordered about an inversion center

Determination of heavy metals in chinese prickly ash from different production areas using inductively coupled plasma-mass spectrometry

Purpose: To determine the heavy metal content of Chinese prickly ash (CPA) produced in various areas of China.Methods: CPA samples collected from different production areas in China were subjected to microwave digestion, and the contents of copper (Cu), nickel (Ni), chromium (Cr), lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), tin (Sn), and antimony (Sb) were determined by inductively coupled plasma-mass spectrometry (ICP-MS).Results: Heavy metal levels in the CPA samples followed the order: Cu (3.29-24.17 mg/kg) > Cr (0.04-7.33 mg/kg) > Ni (0.88-6.86 mg/kg) > Pb (0.00-3.84 mg/kg) > As (0.0011-1.08 mg/kg) > Cd (0.029-0.211 mg/kg) > Sb (0.03-0.21 mg/kg) > Sn (0.00-0.15 mg/kg) > Hg (0.000-0.032 mg/kg). Metal-to-metal correlation studies showed that there were significant correlations between Cu-Cr (p = -4.02), Cu-Ni (p = 0.561), Cu-As (p = 0.554) and Ni-As (p = 0.428) at the 0.01 level. Also, some metal-to-metal correlations were observed in Pb-Cr (p = 0.351), Pb-Cu (p = -0.310), Sb-Cd (p = 0.322), Sb-Hg (p = 0.311) and Cd-Sn (p = 0.309) at the 0.05 level. The highest concentrations of Pb and As in CPA exceeded the maximum permissible limits in China. Based on current safety standards, the concentrations of heavy metals in these CPA samples mean they are safe for human consumption.Conclusions: The status of heavy metal concentrations of CPA should be further investigated in Sichuan, Shaanxi, Shanxi and Jiangsu. In addition, ICP-MS is a reliable and rapid technique for the determination of the heavy metals in CPA.Keywords: Chinese prickly ash, Heavy metals, Inductively-coupled plasma-mass spectrometry, Food safet