Extraction of essential oil from the aerial parts of Artemisia frigida Willd by way of hydrodistillation

This study aims to determine the optimum conditions for extraction of essential oil compounds in the aerial parts of Artemisia frigida Willd. Method: the considered extraction method is hydro-distillation, using a Clevenger apparatus. The effect of particle size of raw material, soaking time, liquid to plant material ratio and extraction time on essential oil yield were investigated through both single factor and multi-factor experiments. Results: In the single factor experiment, the influences of the following factors on essential oil extraction were studied; particle size 0.825 mm, soaking time 2 h, and liquid to plant material ratio 12:1. Under the multi-factor experiment, the influences of multiple factors of extraction conditions on essential oil were considered, particularly, extraction time (C)>soaking time (A)>liquid to plant material ratio. Conclusion: For extraction of essential oil from the aerial parts of Artemisia frigida Willd, the following optimum extraction parameters were identified: 2h of soaking time, 10:1 liquid to solid ratio, and 8h of extraction time

Anti-inflammatory effects, nuclear magnetic resonance identification, and high-performance liquid chromatography isolation of the total flavonoids from Artemisia frigida

AbstractThe aerial parts of Artemisia frigida Willd. are used to treat joint swelling, renal heat, abnormal menstruation, and sore carbuncle. The anti-inflammatory effects of A. frigida have been well-known in folk medicine, suggesting that components extracted from A. frigida could potentially treat inflammatory disease. With the aim of discovering bioactive compounds, in this study, we extracted total flavonoids from the aerial parts of A. frigida and investigated their anti-inflammatory effects against inflammation induced by carrageenan and egg albumin in rats. At the doses studied, total flavonoids (100 mg/kg, 200 mg/kg, and 400 mg/kg) and some isolated compounds (30 mg/kg) showed significant and dose-dependent anti-inflammatory effects. According to the high-performance liquid chromatography analysis of the total flavonoids from A. frigida, there are five major compounds, namely, 5-hydroxy-3′,4′-dimethoxy-7-O-β-d-glucuronide (F1), 5-hydroxy-3′,4′,5′-trimethoxy-7-O-β-d-glucuronide (F2), 5,7,3′-trihydroxy-6,4′-dimethoxyflavone (F3), 5,3′-dihydroxy-6,7,4′-trimethoxyflavone (F4), and 5,3′-dihydroxy-3,6,7,4′-tetramethoxyflavone (F5), which may explain the anti-inflammatory activity

Extraction of auroral oval boundaries from UVI images: A new FLICM clustering-based method and its evaluation

Based on the fuzzy local information c-means (FLICM) clustering algorithm, a new method is developed for extracting the equatorward and poleward boundaries of the auroral oval from images acquired by the Ultraviolet Imager (UVI) aboard the POLAR satellite. First, the method iteratively segments the UVI image with the FLICM clustering algorithm, according to an integrity criterion for the segmented auroral oval. Then, possible gaps in the extracted auroral oval are filled, based on prior knowledge of its shape. To evaluate the method objectively, the extracted boundaries are compared with the precipitating electron boundaries determined from DMSP satellite precipitation particle data. The evaluation results demonstrate that the proposed method generates more accurate auroral boundaries than traditional methods

Critical roles of edge turbulent transport in the formation of high-field-side high-density front and density limit disruption in J-TEXT tokamak

This article presents an in-depth study of the sequence of events leading to density limit disruption in J-TEXT tokamak plasmas, with an emphasis on boudary turbulent transport and the high-field-side high-density (HFSHD) front. These phenomena were extensively investigated by using Langmuir probe and Polarimeter-interferometer diagnostics

Validation of the plasma-wall self-organization model for density limit in ECRH-assisted start-up of Ohmic discharges on J-TEXT

A recently developed plasma-wall self-organization (PWSO) model predicts a significantly enhanced density limit, which may be attainable in tokamaks with ECRH-assisted ohmic startup and sufficiently high initial neutral density. Experiments have been conducted on J-TEXT to validate such a density limit scenario based on this model. Experimental results demonstrate that increasing the pre-filled gas pressure or ECRH power during the startup phase can effectively enhance plasma purity and raise the density limit at the flat-top. Despite the dominant carbon fraction in the wall material, some discharges approach the edge of the density-free regime of the 1D model of PWSO.Comment: 17 pages, 8 figure

Protective effects of ginsenosides Rg1 and Rb1 against cognitive impairment induced by simulated microgravity in rats

Microgravity experienced during space flight is known to exert several negative effects on the learning ability and memory of astronauts. Few effective strategies are currently available to counteract these effects. Rg1 and Rb1, the major steroidal components of ginseng, have shown potent neuroprotective effects with a high safety profile. The present study aimed to investigate the effects of Rg1 and Rb1 on simulated microgravity-induced learning and memory dysfunction and its underlying mechanism in the hindlimb suspension (HLS) rat model. Administration of Rg1 (30 and 60 μmol/kg) and Rb1 (30 and 60 μmol/kg) for 2 weeks resulted in a significant amelioration of impaired spatial and associative learning and memory caused by 4-week HLS exposure, measured using the Morris water maze and Reward operating conditioning reflex (ROCR) tests, respectively. Furthermore, Rg1 and Rb1 administration alleviated reactive oxygen species production and enhanced antioxidant enzyme activities in the prefrontal cortex (PFC). Rg1 and Rb1 also assisted in the recovery of mitochondrial complex I (NADH dehydrogenase) activities, increased the expression of Mfn2 and decreased the fission marker dynamin-related protein (Drp)-1expression. Additionally, Rg1 and Rb1 treatment increased the SYN, and PSD95 protein expressions and decreased the ratio of Bax:Bcl-2 and reduced the expression of cleaved caspase-3 and cytochrome C. Besides these, the BDNF-TrkB/PI3K-Akt pathway was also activated by Rg1 and Rb1 treatment. Altogether, Rg1 and Rb1 treatment attenuated cognitive deficits induced by HLS, mitigated mitochondrial dysfunction, attenuated oxidative stress, inhibited apoptosis, increased synaptic plasticity, and restored BDNF-TrkB/PI3K-Akt signaling

Macronuclear Genome Sequence of the Ciliate Tetrahymena thermophila, a Model Eukaryote

The ciliate Tetrahymena thermophila is a model organism for molecular and cellular biology. Like other ciliates, this species has separate germline and soma functions that are embodied by distinct nuclei within a single cell. The germline-like micronucleus (MIC) has its genome held in reserve for sexual reproduction. The soma-like macronucleus (MAC), which possesses a genome processed from that of the MIC, is the center of gene expression and does not directly contribute DNA to sexual progeny. We report here the shotgun sequencing, assembly, and analysis of the MAC genome of T. thermophila, which is approximately 104 Mb in length and composed of approximately 225 chromosomes. Overall, the gene set is robust, with more than 27,000 predicted protein-coding genes, 15,000 of which have strong matches to genes in other organisms. The functional diversity encoded by these genes is substantial and reflects the complexity of processes required for a free-living, predatory, single-celled organism. This is highlighted by the abundance of lineage-specific duplications of genes with predicted roles in sensing and responding to environmental conditions (e.g., kinases), using diverse resources (e.g., proteases and transporters), and generating structural complexity (e.g., kinesins and dyneins). In contrast to the other lineages of alveolates (apicomplexans and dinoflagellates), no compelling evidence could be found for plastid-derived genes in the genome. UGA, the only T. thermophila stop codon, is used in some genes to encode selenocysteine, thus making this organism the first known with the potential to translate all 64 codons in nuclear genes into amino acids. We present genomic evidence supporting the hypothesis that the excision of DNA from the MIC to generate the MAC specifically targets foreign DNA as a form of genome self-defense. The combination of the genome sequence, the functional diversity encoded therein, and the presence of some pathways missing from other model organisms makes T. thermophila an ideal model for functional genomic studies to address biological, biomedical, and biotechnological questions of fundamental importance

Ground state description of bound polarons in parabolic quantum wires

The Feynman-Haken variational path integral theory is, for the first time, generalized to calculate the ground-state energy of an electron coupled simultaneously to a Coulomb potential and to a longitudinal-optical (LO) phonon field in parabolic quantum wires. It is shown that the polaronic correction to the ground-state energy is more sensitive to the electron-phonon coupling constant than the Coulomb binding parameter and monotonically stronger as the effective wire radius decreases. We apply our calculations to several semiconductor quantum wires and find that the polaronic correction can be considerably large

A unilateral external fixator combined with bone transport and tibio-talar fusion for the treatment of severe postoperative infection of peri-ankle fractures: retrospective analysis of 32 cases

Abstract Background To investigate the clinical effects of a unilateral external fixator combined with bone transport and tibio-talar fusion in the treatment of severe postoperative infection of peri-ankle fractures. Methods The clinical data of 32 patients (22 men and 10 women) with severe postoperative infection of peri-ankle fractures were retrospectively analyzed. Patients’ age ranged from 26 to 62 (mean, 42 ± 9.5) years old. The types of fractures were distal tibia fracture (25 cases), distal tibia and fibula fracture (5 cases), and talus fracture (2 cases). All patients underwent treatment with unilateral external fixation combined with bone transport and tibio-talar fusion. 6 patients with severe infection received two-stage treatment involving focal debridement and external fixation, osteotomy, and bone transport. The remaining 26 patients underwent debridement, external fixation, and osteotomy simultaneously. The length of bone transport, total fixation time of the external fixator, and postoperative complications were recorded for all patients. The efficacy of the treatment was assessed using the American Association of Foot and Ankle Society (AOFAS) ankle–hindfoot score. Results Patients were followed up for 16–36 months, with an average follow-up time of 24 months. The length of tibia bone transport ranged from 5 to 15 cm, with a mean length of 8.5 cm. The external fixator was applied for 12–24 months, with an average duration of 16 months. One patient suffered from refracture at tibio-talar fusion site, and one patient had external fixation pin-tract infection. No complications, such as recurrent infections (especially the MRSA infection), poor mineralization, refracture, iatrogenic nerve damage or fusion failure, were found in the remaining patients. The preoperative AOFAS ankle–hindfoot function score was 40.0 ± 3.8 (range, 30–52) points, and it increased to 75.0 ± 3.0 (range, 67–78) points at the last follow-up. Conclusion A unilateral external fixator combined with bone transport and tibio-talar fusion is an effective method for treating severe postoperative infection of peri-ankle fractures. This approach is capable of reconstructing large bone defects that remain after clearing the infected lesion. Additionally, it provides stability to the ankle, enhances ankle–hindfoot function, and improves the patient’s quality of life

ECS Solid State Lett.

Pd catalysts supported on carbon black and Ti4O7 were prepared and used as electrocatalysts for formic acid electrooxidation. The structure and morphology were characterized by XRD and TEM. CV results show that Pd/Ti4O7 possesses a higher catalytic activity than Pd/C. XPS analyzes suggest that the higher content of metallic Pd caused by Ti4O7 contributes to the better catalytic performance. Based on the good electrocatalytic performance of Pd/Ti4O7, Pd catalyst supported on PDDA-functionalized Ti4O7 was prepared and exhibited a better catalytic activity. The improvement results from the further increase of metallic Pd content due to the presence of PDDA. (C) 2014 The Electrochemical Society. All rights reserved.Pd catalysts supported on carbon black and Ti4O7 were prepared and used as electrocatalysts for formic acid electrooxidation. The structure and morphology were characterized by XRD and TEM. CV results show that Pd/Ti4O7 possesses a higher catalytic activity than Pd/C. XPS analyzes suggest that the higher content of metallic Pd caused by Ti4O7 contributes to the better catalytic performance. Based on the good electrocatalytic performance of Pd/Ti4O7, Pd catalyst supported on PDDA-functionalized Ti4O7 was prepared and exhibited a better catalytic activity. The improvement results from the further increase of metallic Pd content due to the presence of PDDA. (C) 2014 The Electrochemical Society. All rights reserved