WorldWideScience

Sample records for kaempferia parviflora electronic

  1. Aphrodisiac Activity of Kaempferia parviflora

    Directory of Open Access Journals (Sweden)

    Jintanaporn Wattanathorn

    2012-01-01

    Full Text Available Problem statement: The increasing prevalence of sexual dysfunction and the limitation of therapeutic efficacy nowadays give rise to the requirement of novel therapeutic strategy. Kaempferia parviflora or Krachai-Dun has been long term used in Thai traditional folklore to treat this condition. Unfortunately, no scientific document is available until now. Therefore, this study was undertaken to determine the effect of this medicinal plant on male sexual behavior of aging rats subjected to stress. Approach: Aging rats were divided into 2 groups; the vehicle+stress and the K.parviflora+stress. All animals were administered the assigned substance 45 m before they were subjected to the 12-hr stress exposure for 3 weeks. They were determined male sexual behaviors including both latency and frequency of mounting, intromission and ejaculation behaviors after single dose and every week until the end of experimental period. In order to investigate the possible underlying mechanism, we also determined the alteration of DA1-immunopositive stained neurons density in hypothalamus. Results: Our results showed that after the single administration of the plant extract, the intromission frequency increased, it was also found the rats subjected K.parviflora treatment significantly increased the frequency of mounting, intromission and ejaculation while decreased the latencies of all sexual behaviors mentioned earlier. Moreover, K.parviflora also increased D1-immunopositive stained neurons density in hypothalamus. Therefore, the aphrodisiac activity of K.parviflora might be attributed in part to the enhanced dopaminergic function in hypothalamus. Conclusion: Present findings provide experimental evidence that the crude extract of K.parviflora can enhance male sexual behaviors. Therefore, it will be further developed as the functional food or health product for men especially for men who are risk for sexual dysfunction.

  2. Bioactive flavonoids from Kaempferia parviflora.

    Science.gov (United States)

    Yenjai, Chavi; Prasanphen, Khanchara; Daodee, Supawadee; Wongpanich, Varima; Kittakoop, Prasat

    2004-01-01

    Nine flavonoids (1-9) have been isolated from Kaempferia parviflora. Among these, 5,7,4'-trimethoxyflavone (8) and 5,7,3',4'-tetramethoxyflavone (9) exhibited antiplasmodial activity against Plasmodium falciparum, with IC50 values of 3.70 and 4.06 microg/ml, respectively. 3,5,7,4'-Tetramethoxyflavone (7) and compound 8 possessed antifungal activity against Candida albicans with respective IC50 values of 39.71 and 17.63 microg/ml, and also showed mild antimycobacterial activity with the minimum inhibitory concentrations (MIC) of 200 and 50 microg/ml, respectively. However, none of the isolated compounds demonstrated cytotoxicity against KB, BC and NCI-H187 cell lines.

  3. Phenolic glycosides from Kaempferia parviflora.

    Science.gov (United States)

    Azuma, Toshiaki; Tanaka, Yasuo; Kikuzaki, Hiroe

    2008-11-01

    Three phenolic glycosides were isolated together with two known flavonol glycosides from the H2O-soluble fraction of rhizomes of Kaempferia parviflora. Their structures were determined to be rel-(5aS,10bS)-5a,10b-dihydro-1,3,5a,9-tetrahydroxy-8-methoxy-6H-benz[b]indeno[1,2-d]furan-6-one 5a-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside] (1), its rel-5aS,10bR isomer (2), and (2R,3S,4S)-3-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-d-glucopyranosyl]-3'-O-methyl-ent-epicatechin-(2alpha-->O-->3,4alpha-->4)-(5aS,10bS)-5a,10b-dihydro-1,3,5a,9-tetrahydroxy-8-methoxy-6H-benz[b]indeno[1,2-d]furan-6-one 5a-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside] (3). The structures were elucidated on the basis of analyses of chemical and spectroscopic evidence.

  4. Suppression of benign prostate hyperplasia by Kaempferia parviflora rhizome

    OpenAIRE

    Kazuya Murata; Hirotaka Hayashi; Shinichi Matsumura; Hideaki Matsuda

    2013-01-01

    Background: Kaempferia parviflora rhizome is used as a folk medicine in Thailand for the treatment of various symptoms. In the present study, the inhibitory activities of extract from K. parviflora rhizome against 5a-reductase (5aR) were subjected. Furthermore, the effects of the extract from K. parviflorar hizome in benign prostate hyperplasia (BPH) were studied using the model mice. Materials and Methods: Preparations of extracts from the rhizomes of K. parviflora, Curcuma zedoaria and Zing...

  5. Anti-gastric ulcer effect of Kaempferia parviflora.

    Science.gov (United States)

    Rujjanawate, C; Kanjanapothi, D; Amornlerdpison, D; Pojanagaroon, S

    2005-10-31

    Kaempferia parviflora is a Zingiberaceous plant, which has been reputed for its beneficial medicinal effects. The present study was undertaken to evaluate the Kaempferia parviflora ethanolic extract (KPE) for its anti-gastric ulcer activity by experimental models. Oral administration of the KPE at 30, 60 and 120 mg/kg significantly inhibited gastric ulcer formation induced by indomethacin, HCl/EtOH and water immersion restraint-stress in rats. In pylorus-ligated rats, pretreatment with the KPE had no effect on gastric volume, pH and acidity output. In ethanol-induced ulcerated rats, gastric wall mucus was significantly preserved by the KPE pretreatment at doses of 60 and 120 but not at 30 mg/kg. The findings indicate that the ethanolic extract of Kaempferia parviflora possesses gastroprotective potential which is related partly to preservation of gastric mucus secretion and unrelated to the inhibition of gastric acid secretion.

  6. Suppression of benign prostate hyperplasia by Kaempferia parviflora rhizome

    Directory of Open Access Journals (Sweden)

    Kazuya Murata

    2013-01-01

    Full Text Available Background: Kaempferia parviflora rhizome is used as a folk medicine in Thailand for the treatment of various symptoms. In the present study, the inhibitory activities of extract from K. parviflora rhizome against 5a-reductase (5aR were subjected. Furthermore, the effects of the extract from K. parviflorar hizome in benign prostate hyperplasia (BPH were studied using the model mice. Materials and Methods: Preparations of extracts from the rhizomes of K. parviflora, Curcuma zedoaria and Zingiber officinale, and methoxyflavones isolated from K. parviflora was used for 5aR inhibition assay. The effects of K. parviflora extract on growth suppression for the prostates and seminal vesicles were performed based on the Hershberger′s method. The K. parviflora extract was administered to castrated mice for 14 days. Results: K. parviflora extract showed more potent inhibitory activity on 5aR than C. zedoaria and Z. officinale extracts. The active principles were identified as 3,5,7,3′,4′-pentamethoxyflavone and 5,7,3′,4′-tetramethoxyflavone by activity guided fractionation. Furthermore, K. parviflora extract suppressed the weights of prostates and seminal vesicles in BPH model rats by daily administration for 14 days. Conclusion: These results indicate that K. parviflora extract can be a promising agent for the treatment of BPH.

  7. Suppression of benign prostate hyperplasia by Kaempferia parviflora rhizome.

    Science.gov (United States)

    Murata, Kazuya; Hayashi, Hirotaka; Matsumura, Shinichi; Matsuda, Hideaki

    2013-10-01

    Kaempferia parviflora rhizome is used as a folk medicine in Thailand for the treatment of various symptoms. In the present study, the inhibitory activities of extract from K. parviflora rhizome against 5α-reductase (5αR) were subjected. Furthermore, the effects of the extract from K. parviflorar hizome in benign prostate hyperplasia (BPH) were studied using the model mice. Preparations of extracts from the rhizomes of K. parviflora, Curcuma zedoaria and Zingiber officinale, and methoxyflavones isolated from K. parviflora was used for 5αR inhibition assay. The effects of K. parviflora extract on growth suppression for the prostates and seminal vesicles were performed based on the Hershberger's method. The K. parviflora extract was administered to castrated mice for 14 days. K. parviflora extract showed more potent inhibitory activity on 5αR than C. zedoaria and Z. officinale extracts. The active principles were identified as 3,5,7,3',4'-pentamethoxyflavone and 5,7,3',4'-tetramethoxyflavone by activity guided fractionation. Furthermore, K. parviflora extract suppressed the weights of prostates and seminal vesicles in BPH model rats by daily administration for 14 days. These results indicate that K. parviflora extract can be a promising agent for the treatment of BPH.

  8. Anti-allergic activity of compounds from Kaempferia parviflora.

    Science.gov (United States)

    Tewtrakul, Supinya; Subhadhirasakul, Sanan; Kummee, Sopa

    2008-02-28

    Kaempferia parviflora is one of the plants in the Zingiberaceae family, locally known in Thai as kra-chai-dam. In Thai traditional medicine, the decoction of Kaempferia parviflora powder with alcohol has been reported to cure allergy, asthma, impotence, gout, diarrhea, dysentery, peptic ulcer and diabetes. Therefore, the present study aimed to investigate anti-allergic substances from this plant. Bioassay-guided fractionation led to the isolation of seven methoxyflavone derivatives (1-7) from Kaempferia parviflora extract and they were identified on the basis of spectroscopic methods. Among the compounds tested, 5-hydroxy-3,7,3',4'-tetramethoxyflavone (5) possessed the highest anti-allergic activity against antigen-induced beta-hexosaminidase release as a marker of degranulation in RBL-2H3 cells with an IC(50) value of 8.0 microM, followed by 5-hydroxy-7-methoxyflavone (2, IC(50)=20.6 microM) and 5-hydroxy-7,4'-dimethoxyflavone (4, IC(50)=26.0 microM), whereas others showed moderate activities (IC(50)=37.5-66.5 microM). Structure-activity trends of 7-methoxyflavone derivatives on anti-allergic activity can be summarized as follows: (1) substitution with vicinal methoxyl groups at positions 3' and 4' conferred higher activity than only one methoxylation, (2) methoxylation at position 3 reduced activity and (3) methoxylation at position 5 showed higher activity than hydroxylation. Compounds 2, 4 and 5 were also determined for their mechanisms on ionomycin-induced beta-hexosaminidase release. The results indicated that the mechanism on inhibition of cell degranulation of compounds 2 and 5 mainly involve the inhibition of Ca(2+) influx to the cells, whereas that of 4 may be partly due to this inhibition. In regards to the active constituents for anti-allergic activity of Kaempferia parviflora, 5-hydroxy-3,7,3',4'-tetramethoxyflavone (5), 5-hydroxy-7-methoxyflavone (2) and 5-hydroxy-7,4'-dimethoxyflavone (4) are responsible for anti-allergic effect of this plant. The

  9. Modulatory effects of Kaempferia parviflora extract on mouse hepatic cytochrome P450 enzymes.

    Science.gov (United States)

    Mekjaruskul, Catheleeya; Jay, Michael; Sripanidkulchai, Bungorn

    2012-06-14

    Kaempferia parviflora is a herbal plant, the extracts of which are commonly used as alternative medicines. It widely uses as aphrodisiac, anti-inflammation, anti-microbacterial, and anti-peptic ulcer. In order to obtain an effective utilization and safety of the herb, the influence of Kaempferia parviflora on hepatic CYP450 metabolizing enzymes including CYP1A1, CYP1A2, CYP2B, CYP2E1, and CYP3A was investigated. The impact of Kaempferia parviflora on CYP450 both in vitro and in vivo was examined by using ethoxyresorufin O-dealkylation, methoxyresorufin O-dealkylation, pentoxyresorufin O-dealkylation, p-nitrophenol hydroxylation, and erythromycin N-demethylation assays, respectively. In vitro studies using non-induced mouse hepatic microsomes in the presence or absence of Kaempferia parviflora extract showed that Kaempferia parviflora extract altered CYP1A1, CYP1A2, CYP2B, and CYP2E1 activities by non-competitive, mixed-competitive, competitive, and uncompetitive mechanisms, respectively. Among these enzymes, CYP1A2 was affected by Kaempferia parviflora based on the highest value of V(max) (15.276±0.206 nmol/min) and lowest of K(i) value (0.008±0.002 μg/ml). In addition, the plant extract also modulated CYP2B activity based on the low K(m) value (1.599±0.147 pmol). For in vivo studies, mice were orally treated with 250 mg/kg of Kaempferia parviflora extract for 7, 14, and 21 days. The results demonstrated that Kaempferia parviflora extract significantly induced CYP1A1, CYP1A2 enzyme activities following short-term treatment. CYP2B enzyme activities were markedly increased all Kaempferia parviflora extract treatment timepoints, whereas Kaempferia parviflora extract significantly enhanced CYP2E1 activity only after long-term treatment. However, Kaempferia parviflora extract did not affect the CYP3A enzyme activity. Kaempferia parviflora extract modulated several CYP450 enzyme activities, thus, its utilization with drugs or other herbs should raise concern for

  10. Improvement in blood fluidity by Kaempferia parviflora rhizome.

    Science.gov (United States)

    Murata, Kazuya; Deguchi, Takahiro; Fujita, Takanori; Matsuda, Hideaki

    2013-10-01

    Improvement in blood fluidity leads to the prevention of various lifestyle-related diseases. A raw material for improving blood fluidity has been long desired in the research area of functional and supplemental foods. We successfully showed an improvement in blood fluidity by the Zingiberaceae plant, Kaempferia parviflora. The rhizome of the plant reduced the blood passage time through a micro slit using a disseminated intravascular coagulation model. The mechanism was attributed to the activation of fibrinolysis, as demonstrated by elongation of the euglobulin lysis time and an in-vitro fibrinolysis assay. The active principles were determined to be methoxyflavones. The results show that the rhizome of K. parviflora is a promising candidate preventive agent for treating lifestyle-related diseases.

  11. Kaempferia parviflora Extract Exhibits Anti-cancer Activity against HeLa Cervical Cancer Cells

    National Research Council Canada - National Science Library

    Saranyapin Potikanond; Siriwoot Sookkhee; Mingkwan Na Takuathung; Pitchaya Mungkornasawakul; Nitwara Wikan; Duncan R. Smith; Wutigri Nimlamool

    2017-01-01

    Kaempferia parviflora (KP) has been traditionally used as a folk remedy to treat several diseases including cancer, and several studies have reported cytotoxic activities of extracts of KP against a number of different cancer cell lines...

  12. A thermostable lectin from the rhizomes of Kaempferia parviflora.

    Science.gov (United States)

    Konkumnerd, Wichchulada; Karnchanatat, Aphichart; Sangvanich, Polkit

    2010-08-30

    Kaempferia parviflora, or black galingale (Kra-Chai-Dam), belongs to the Zingiberaceae family and is used as both a food ingredient and a medicinal plant. There are diverse reports on the biological activities of compounds extracted from the plant, such as antimalarial, antifungal and an effective sexual-enhancing role, but not on the lectins. A lectin was isolated from the rhizomes of Kaempferia parviflora using affinity chromatography on Concanavalin A followed by gel filtration chromatography on Sephacryl S-100. The molecular weight of the purified lectin was about 41.7 kDa. This lectin showed haemagglutinating activity against erythrocytes from several sources, with the highest level being against those from rabbits. Moreover, the lectin was thermostable, with significant haemagglutinating activity detectable up to 75 degrees C. The results of trypsin digestion and liquid chromatography/tandem mass spectrometry analysis suggested that this protein could be a member of the lectin/endochitnase1 family. A lectin that showed thermotolerant haemagglutinating activity against erythrocytes from several sources was successfully purified from K. paviflora rhizomes. Peptide sequence analysis indicated that this lectin is similar to lectin/endochitinase 1 (Urtica dioica) or Hevein-like protein (Hevea brasiliensis). Copyright (c) 2010 Society of Chemical Industry.

  13. Clinical Effects of Krachaidum (Kaempferia parviflora): A Systematic Review.

    Science.gov (United States)

    Saokaew, Surasak; Wilairat, Preyanate; Raktanyakan, Paranya; Dilokthornsakul, Piyameth; Dhippayom, Teerapon; Kongkaew, Chuenjid; Sruamsiri, Rosarin; Chuthaputti, Anchalee; Chaiyakunapruk, Nathorn

    2016-09-30

    Kaempferia parviflora (Krachaidum) is a medicinal plant in the family Zingiberaceae. Its rhizome has been used as folk medicine for many centuries. A number of pharmacological studies of Krachaidum had claimed benefits for various ailments. Therefore, this study aimed to systematically search and summarize the clinical evidences of Krachaidum in all identified indications. Of 683 records identified, 7 studies were included. From current clinical trials, Krachaidum showed positive benefits but remained inconclusive since small studies were included. Even though results found that Krachaidum significantly increased hand grip strength and enhanced sexual erotic stimuli, these were based on only 2 studies and 1 study, respectively. With regard to harmful effects, we found no adverse events reported even when Krachaidum 1.35 g/day was used. Therefore, future studies of Krachaidum are needed with regards to both safety and efficacy outcomes. © The Author(s) 2016.

  14. Modulation of function of multidrug resistance associated-proteins by Kaempferia parviflora extracts and their components

    OpenAIRE

    Patanasethanont, Denpong; NAGAI, Junya; Matsuura, Chie; Fukui, Kyoko; Sutthanut, Khaetthareeya; Sripanidkulchai, Bung-Orn; Yumoto, Ryoko; Takano, Mikihisa

    2007-01-01

    In this study, the effects of extracts and flavone derivatives from the rhizome of Kaempferia parviflora on multidrug resistance associated-proteins (MRP)-mediated transport in A549 cells were examined. The cells employed express MRP1 and MRP2, but not P-glycoprotein. The cellular accumulation of calcein, an MRP substrate, was significantly increased by various MRP inhibitors without being affected by verapamil, a typical P-glycoprotein inhibitor. Ethanol and aqueous extracts from Kaempferia ...

  15. Effects of Kaempferia parviflora extracts and their flavone constituents on P-glycoprotein function

    OpenAIRE

    Patanasethanont, Denpong; NAGAI, Junya; Yumoto, Ryoko; MURAKAMI, TERUO; Sutthanut, Khaetthareeya; Sripanidkulchai, Bung-Orn; Yenjai, Chavi; Takano, Mikihisa

    2006-01-01

    The purpose of this study was to examine the effects of extracts and flavone derivatives from the rhizome of Kaempferia parviflora on P-glycoprotein (P-gp)-mediated transport in LLC-GA5-COL150, a transfectant cell line of a porcine kidney epithelial cell line LLC-PK1 with human MDR1 cDNA. Ethanol extract obtained from Kaempferia parviflora rhizome significantly increased the accumulation of rhodamine 123 and daunorubicin, P-gp substrates, in LLC-GA5-COL150 cells, but not in LLC-PK1 cells. The...

  16. Improved dissolution of Kaempferia parviflora extract for oral administration by preparing solid dispersion via solvent evaporation

    Directory of Open Access Journals (Sweden)

    Yotsanan Weerapol

    2017-03-01

    Full Text Available Kaempferia parviflora, a plant in the family Zingiberaceae, has been used in Thai traditional medicines for treating hypertension and promoting longevity with good health and well-being. However, its limited aqueous solubility and low dissolution restrict its bioavailability. The aim of the study was therefore to improve the dissolution rate of K. parviflora extracted with dichloromethane (KPD by solid dispersions. Different water-soluble polymers were applied to improve dissolution of KPD. The solid dispersions in different ratios were prepared by solvent evaporation method. Only hydroxypropyl methylcellulose (HPMC and polyvinyl alcohol-polyethylene glycol grafted copolymer (PVA-co-PEG could be used to produce homogeneous, powdered solid dispersions. Physical characterization by scanning electron microscopy, hot stage microscopy, differential scanning calorimetry and powder X-ray diffractometry, in comparison with corresponding physical mixtures, showed the changes in solid state during the formation of solid dispersions. Dissolution of a selected marker, 5,7,4′-trimethoxyflavone (TMF, from KPD/HPMC and KPD/PVA-co-PEG solid dispersions was significantly improved, compared with pure KPD. The dissolution enhancement by solid dispersion was influenced by both type and content of polymers. The stability of KPD/HPMC and KPD/PVA-co-PEG solid dispersions was also good after 6-month storage in both long-term and accelerated conditions. These results identified that the KPD/HPMC and KPD/PVA-co-PEG solid dispersions were an effective new approach for pharmaceutical application of K. parviflora.

  17. Antimicrobial activity of the ethanol extract and compounds from the rhizomes of Kaempferia parviflora

    OpenAIRE

    Sopa Kummee; Supinya Tewtrakul; Sanan Subhadhirasakul

    2008-01-01

    The antimicrobial activity of the ethanol extract of Kaempferia parviflora was tested against human pathogens,including bacteria, yeast and dermatophyte fungi, using the agar disc diffusion. The ethanol extract exhibited strong antifungalactivity against dermatophytes with clear zone values from 10.7-19.8 mm at concentration of 2 mg/disc. However,ethanol extract showed no activities against all bacteria and yeast tested. The ethanol extract and seven compounds of K.parviflora were further stu...

  18. Solid lipid nanoparticles for topical administration of Kaempferia parviflora extracts.

    Science.gov (United States)

    Sutthanut, Khaetthareeya; Lu, Xiuling; Jay, Michael; Sripanidkulchai, Bungorn

    2009-04-01

    Extracts of Kaempferia parviflora (KP) were formulated in solid lipid nanoparticles (SLNs) in order to enhance their transdermal permeability. The KP extracts were entrapped within SLNs by adding them to a melted mixture of oils, surfactants and PEGylating agents and subsequently forming an oil-in-water microemulsion at an elevated temperature. Cooling of this microemulsion resulted in the formation of SLNs. The formulation with the optimum properties was composed of stearyl alcohol as the nanoparticle matrix and Tocopheryl Polyethylene Glycol Succinate (TPGS) as the surfactant. Particle sizes of 82-108 nm were obtained with entrapment efficiencies as high as 87%. The release of the flavonoids from the SLN matrix was measured after suspending them in a Phosphate Buffered Saline (PBS)/Tween 80 solution and demonstrated biphasic patterns. Permeability studies using a skin model composed of human-derived epidermal keratinocytes were conducted in which a topically applied KP extract-loaded SLN was compared to a KP-hydroxypropyl methylcellulose/Tween 80 gel formulation containing KP extract. The amount of total KP flavonoids in the SLNs and gel that had permeated through the skin after 25 hours (95.57 +/- 9.08 and 81.04 +/- 5.82 g, respectively) were found to be significantly different (P < 0.05). In addition, the flux values of three of the flavonoids were greater when incorporated in SLNs.

  19. Effect of Kaempferia parviflora extract on knee osteoarthritis.

    Science.gov (United States)

    Kobayashi, Hiroko; Suzuki, Ryo; Sato, Kei; Ogami, Takatoshi; Tomozawa, Hiroshi; Tsubata, Masahito; Ichinose, Koji; Aburada, Masaki; Ochiai, Wataru; Sugiyama, Kiyoshi; Shimada, Tsutomu

    2017-08-19

    Knee osteoarthritis (OA) is becoming more prevalent worldwide due to increases in the numbers of elderly and obese patients. Currently, pharmaceutical medicines used for the treatment of OA are for symptomatic therapy and therefore new therapeutic agents are needed. Kaempferia parviflora (KP) is a plant growing naturally in Southeast Asia and has various pharmacological effects including an anti-inflammatory effect, but no effect on OA has yet been reported. We therefore conducted a search for the effects KP and the active components of KP extract (KPE) exert on OA as well as its mechanism of action. Results from a study of KPE using the monoiodoacetic acid rat OA model revealed that KPE reduced the pain threshold and severity of osteoarthritic cartilage lesions. The mechanism of action and active components were then investigated using IL-1β-treated human knee-derived chondrocytes. KPE, as well as 5,7-dimethoxyflavone and 5,7,4'-trimethoxyflavone, which are key constituents of KPE and highly absorbable into the body, reduced the expression of matrix metalloproteinases (MMPs), which are the main extracellular matrix enzymes that degrade collagen within cartilage. As mentioned above, KPE acted to suppress OA and 5,7-dimethoxyflavone and 5,7,4'-trimethoxyflavone were shown to be involved as part of KPE's mechanism that inhibits MMPs.

  20. Anticholinesterase activity of 7-methoxyflavones isolated from Kaempferia parviflora.

    Science.gov (United States)

    Sawasdee, Pattara; Sabphon, Chalisa; Sitthiwongwanit, Duangporn; Kokpol, Udom

    2009-12-01

    The rhizome of Kaempferia parviflora or kra-chai-dum (in Thai) is used traditionally as a folk medicine. The preliminary cholinesterase inhibitory screening of this plant extract exhibited significant acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Thirteen known methoxyflavones (1-13) were isolated and their structures were completely elucidated based on NMR analysis and compared with literature reports. Minor compounds 12-13 were reported for the first time from this species. The cholinesterase inhibitory test results showed that the highest potential inhibitors toward AChE and BChE were 5,7,4'-trimethoxyflavone (6) and 5,7-dimethoxyflavone (7), respectively, with the percentage inhibitory activity varying over 43-85%. The structure-activity relationship study led to the conclusion that compounds bearing 5,7-dimethoxy groups and a free substituent at C-3 had a significant inhibitory effect at a concentration of 0.1 mg/mL, but those bearing a 5-hydroxyl group reduced the inhibitory potency. On the other hand, flavones bearing a 3'- or 5'-methoxy group did not influence the inhibitory effect. Interestingly, 5,7-dimethoxyflavone (7) exhibited strong selectivity for BChE over AChE which may be of great interest to modify as a treatment agent for Alzheimer's disease. Copyright (c) 2009 John Wiley & Sons, Ltd.

  1. Pharmacokinetic interaction between Kaempferia parviflora extract and sildenafil in rats.

    Science.gov (United States)

    Mekjaruskul, Catheleeya; Sripanidkulchai, Bungorn

    2015-04-01

    Kaempferia parviflora (KP) is a plant widely used in Southeast Asia. Its major compounds are 3,5,7,3',4'-pentamethoxyflavone (PMF), 5,7,4'-trimethoxylflavone (TMF), and 5,7-dimethoxyflavone (DMF). This study investigated the effect of KP extract on the blood levels and pharmacokinetics of sildenafil co-administration in rats. Rats were randomly assigned to four groups. Groups 1, 2, and 3 were given sildenafil 20 mg/kg daily for 9 days. On days 4-9 of each treatment period, the treated rats received KP extract (250 mg/kg) and vehicle (groups 2 and 3, respectively). Group 4 received KP extract only (250 mg/kg daily for 9 days). Daily blood concentrations of sildenafil, PMF, TMF, and DMF were determined by HPLC to evaluate the daily blood level interactions. Additional blood samples were collected at various times on the last day of treatment to evaluate the pharmacokinetic interactions. The KP extract decreased blood levels of sildenafil on the first day of co-administration by 95 % but the percentage reduction was insignificant on subsequent days. When co-administered with KP extract, the area under the curve (AUC), maximum concentration (C max), and half-life (T 1/2) of sildenafil were decreased by 60-65, 40-52, and 32-54 %, respectively, with the elimination rate constant (K e) increased by 37-77 %. In addition, PMF, TMF, and DMF concentrations and their AUC, C max, T max, K e, and T 1/2 values were changed after co-administration of KP extract and sildenafil.

  2. Suppression of adipocyte hypertrophy by polymethoxyflavonoids isolated from Kaempferia parviflora.

    Science.gov (United States)

    Okabe, Yui; Shimada, Tsutomu; Horikawa, Takumi; Kinoshita, Kaoru; Koyama, Kiyotaka; Ichinose, Koji; Aburada, Masaki; Takahashi, Kunio

    2014-05-15

    We previously demonstrated that ethyl acetate extracts of Kaempferia parviflora Wall. Ex Baker (KPE) improve insulin resistance in TSOD mice and showed that its components induce differentiation and adipogenesis in 3T3-L1 preadipocytes. The present study was undertaken to examine whether KPE and its isolated twelve components suppress further lipid accumulation in 3T3-L1 mature adipocytes. KPE reduced intracellular triglycerides in mature adipocytes, as did two of its components, 3,5,7,3',4'-pentamethoxyflavone and 5,7,4'-trimethoxyflavone. Shrinkage of lipid droplets in mature adipocytes was observed, and mRNA expression levels of adipose tissue triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) were up-regulated by these two polymethoxyflavonoids (PMFs). Furthermore, the protein expression level of ATGL and the release level of glycerol into the cell culture medium increased. In contrast, the peroxisome proliferator-activated receptor γ (PPARγ) agonist, troglitazone, did not decrease intracellular triglycerides in mature adipocytes, and the mRNA expression level of PPARγ was not up-regulated in mature adipocytes treated with the two active PMFs. Therefore, suppression of lipid accumulation in mature adipocytes is unlikely to be enhanced by transcriptional activation of PPARγ. These results suggest that KPE and its active components enhance lipolysis in mature adipocytes by activation of ATGL and HSL independent of PPARγ transcription, thus preventing adipocyte hypertrophy. On the other hand, the full hydroxylated flavonoid quercetin did not show the suppressive effects of lipid accumulation in mature adipocyte in the same conditions. Consequently, methoxy groups in the flavones are important for the activity. Copyright © 2014 Elsevier GmbH. All rights reserved.

  3. Ethanolic rhizome extract from Kaempferia parviflora Wall. ex. Baker induces apoptosis in HL-60 cells.

    Science.gov (United States)

    Banjerdpongchai, Ratana; Suwannachot, Kittiphan; Rattanapanone, Viboon; Sripanidkulchai, Bungorn

    2008-01-01

    Kaempferia parviflora Wall. ex. Baker is a Thai herb containing many flavonoids that have anti-inflammatory, anti-allergic and antioxidant activities. The objective of this study was to demonstrate apoptotic effects of Kaempferia parviflora Wall. ex. Baker rhizome ethanolic extract on HL-60 cells in vitro. The extract suppressed HL-60 cell growth and decreased cell viability in a dose- and time-dependent manner. Apoptotic cell death was demonstrated by changes in cell morphology, externalization of phosphatidylserine on the cell surface, loss in mitochondrial transmembrane potential and activation of caspase 3. Apoptosis induced by K. parviflora Wall. ex. Baker rhizome ethanolic extract was enhanced by treatment with paclitaxel or doxorubicin, and inhibitors of Akt, PI3-K and MEK.

  4. Effect of Kaempferia parviflora Extract on Physical Fitness of Soccer Players: A Randomized Double-Blind Placebo-Controlled Trial

    OpenAIRE

    Promthep, Kreeta; Eungpinichpong, Wichai; Sripanidkulchai, Bungorn; Chatchawan, Uraiwan

    2015-01-01

    Background Physical fitness is a fundamental prerequisite for soccer players. Kaempferia parviflora is an herbal plant that has been used in some Asian athletes with the belief that it might prevent fatigue and improve physical fitness. This study aimed to determine the effects of Kaempferia parviflora on the physical fitness of soccer players. Material/Methods Sixty soccer players who routinely trained at a sports school participated in a double-blind placebo-controlled trial and were random...

  5. Effects of Kaempferia parviflora extracts and their flavone constituents on P-glycoprotein function.

    Science.gov (United States)

    Patanasethanont, Denpong; Nagai, Junya; Yumoto, Ryoko; Murakami, Teruo; Sutthanut, Khaetthareeya; Sripanidkulchai, Bung-Orn; Yenjai, Chavi; Takano, Mikihisa

    2007-01-01

    The purpose of this study was to examine the effects of extracts and flavone derivatives from the rhizome of Kaempferia parviflora on P-glycoprotein (P-gp)-mediated transport in LLC-GA5-COL150, a transfectant cell line of a porcine kidney epithelial cell line LLC-PK1 with human MDR1 cDNA. Ethanol extract obtained from Kaempferia parviflora rhizome significantly increased the accumulation of rhodamine 123 and daunorubicin, P-gp substrates, in LLC-GA5-COL150 cells, but not in LLC-PK1 cells. The aqueous extract also increased the accumulation in LLC-GA5-COL150 cells with lower potency than the ethanol extract. The effects of flavone derivatives isolated from the rhizome of Kaempferia parviflora on P-gp function were examined. Among six flavones tested, 3,5,7,3',4'-pentamethoxyflavone most potently increased the accumulation of rhodamine 123 and daunorubicin in LLC-GA5-COL150 cells in a concentration-dependent manner. In addition, 5,7-dimethoxyflavone to lesser degree increased rhodamine 123 accumulation in LLC-GA5-COL150 cells. In contrast, the other four flavone derivatives had no significant effect on the accumulation of rhodamine 123 in LLC-GA5-COL150 cells in a concentration range tested. These results indicate that extracts and flavone derivatives from the rhizome of Kaempferia parviflora can inhibit P-gp function, which may be useful for overcoming P-gp-mediated multidrug resistance and improving the oral bioavailability of anticancer agents. (c) 2006 Wiley-Liss, Inc. and the American Pharmacists Association.

  6. Anti-inflammatory mechanism of Kaempferia parviflora in murine macrophage cells (RAW 264.7) and in experimental animals.

    Science.gov (United States)

    Sae-wong, Chutha; Tansakul, Pimpimon; Tewtrakul, Supinya

    2009-07-30

    The rhizomes of Kaempferia parviflora Wall. ex Baker have been used in Thailand for treatment of gout, apthous ulcer, peptic ulcer and abscesses. In our previous study, the crude ethanol extract of Kaempferia parviflora and its compound (5, 5-hydroxy-3,7,3',4'-tetramethoxyflavone), was reported to show nitric oxide (NO) inhibition in RAW 264.7 cells. The present study is thus investigated the anti-inflammatory mechanism of Kaempferia parviflora extract and compound 5 against inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expressions. The extract of Kaempferia parviflora and its compound were tested against NO and prostaglandin E(2) (PGE(2)) releases using RAW264.7 cells as well as studied on anti-inflammatory activity in carrageenan-induced rat paw edema and acute toxicity in mice. The results revealed that the ethanol extract of Kaempferia parviflora markedly inhibited PGE(2) release with an IC(50) value of 9.2 microg/ml. This plant extract and compound 5 also suppressed mRNA expression of iNOS in dose-dependent manners, whereas COX-2 mRNA expression was partly affected. According to the in vivo study, chloroform and hexane fractions greater decreased rat paw edema than ethanol, ethyl acetate and water fractions. The mechanisms for anti-inflammatory activity of Kaempferia parviflora and compound 5 are mainly due to the inhibition of iNOS mRNA expression but partly through that of COX-2 mRNA.

  7. Efficacy of Kaempferia parviflora in a mouse model of obesity-induced dermatopathy.

    Science.gov (United States)

    Hidaka, Moeko; Horikawa, Kazumasa; Akase, Tomoko; Makihara, Hiroko; Ogami, Takatoshi; Tomozawa, Hiroshi; Tsubata, Masahito; Ibuki, Ai; Matsumoto, Yutaka

    2017-01-01

    Obesity results from excessive energy intake and physical inactivity, and predisposes one to various diseases. One of these reasons is that enlargement of adipocytes raises the lipid metabolic abnormalities that affect various organs. The skin is one such organ, and it has been reported that subcutaneous adipocyte cells secrete various factors and these factors are involved in reduction of dermal collagen fibers and fragility of the skin in obesity. The present study explored the efficacy of Kaempferia parviflora (KP) in preventing obesity-induced dermatopathy. We used Tsumura Suzuki obese diabetes (TSOD) mice as an obesity model. TSOD mice were fed a standard diet (MF) mixed with either an ethanol extract from KP (KPE), polymethoxyflavonoid-rich extract from KP (PMF), or polymethoxyflavonoid-poor extract from KP (X). We then evaluated the effect of these three KP fractions on aging-like skin damage induced by UVB irradiation. KPE and PMF caused a significant decrease of mouse body weight, and suppressed the increase in the thickness of the subcutaneous fat layer. In addition, KPE shifted the frequency of subcutaneous adipocyte sizes towards smaller cells possibly via its polypharmacological actions. Scanning electron microscopy revealed that the stereostructure of the collagenous fibers in the dermis was better retained in the KPE and PMF groups, in that order. These results offer the first evidence that KPE can attenuate obesity-induced dermatopathy more effectively than PMF, suggesting that KPE (or KP) might be a candidate supplement for preventing obesity-related skin disorders.

  8. Effect of Kaempferia parviflora Wall. ex. Baker on sexual activity of male rats and its toxicity.

    Science.gov (United States)

    Sudwan, Paiwan; Saenphet, Kanokporn; Saenphet, Supap; Suwansirikul, Songkiet

    2006-01-01

    Kaempferia parviflora Wall. Ex. Baker (Krachaidum) has long been used among Thai men for sexual enhancement. The aim of this study was to determine the effect of K. parviflora ethanolic extract on the sexual behavior of male rats and its toxicity. The experiment was divided into three groups of rats given K. parviflora extract at doses of 60, 120, and 240 mg/kg BW for 60 days, whilst a control group received distilled water at 1 ml/day per oral. The results showed that all groups of male rats had significantly higher courtship behavior during the first 10-minute period of observation than in the 2nd and 3rd 10-minute periods, except those receiving the highest dose of K. parviflora. They revealed the same amount of courtship behavior throughout a whole 30-minute period, which was significantly lower than the control group. There was no significant difference between treated and control groups in other sexual behaviors; mount frequency (MF), intromission frequency (IF), mount latency (ML), or intromission latency (IL). Toxicological study revealed no significant difference of hemoglobin, WBC or differential cell count. All dosages had no effect on kidney and liver function, according to the normal values of blood urea nitrogen (BUN), creatinine (Crea), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Nevertheless, the histopathological study showed a morphological change in the liver. It was concluded that K. parviflora extract at 240 mg/kg BW reduced the time in the first 10 mintues of rat courtship behavior and the use of high and chronic doses of K. parviflora in humans should be considered inadvisable.

  9. Screening Neuropharmacological Activities of Kaempferia parviflora (Krachai Dam in Healthy Adult Male Rats

    Directory of Open Access Journals (Sweden)

    Thaneeya Hawiset

    2011-01-01

    Full Text Available Problem statement: Although the global prevalence of psychological disorders is increasing continually, the efficacies of therapeutic strategies are still very limited. Oxidative stress has been implicated in the pathogenesis of psychiatric disorders and substance possessing antioxidant activity can alleviate the mentioned conditions. Therefore, we hypothesized that Kaempferia parviflora, a medicinal plant claimed for nerve tonic, also possessed the neuropharmacological activities which provide the advantage for psychiatric disorders. Approach: Adult male Wistar rats, weighing 180-220 grams, were orally given the ethanolic extract of K. parviflora at doses of 150, 200 and 250 mg kg-1 BW once daily for 2 weeks. Then, they were determined the neuropharmacological activities including anxiolytic, anti-depression like behavior and cognitive enhancement after single dose, 1 and 2 weeks of treatment. Results: K. parviflora possessed anti-depression like behavior and cognitive enhancement at all treatment duration. Unfortunately, this substance failed to show anxiolytic like activity. Conclusion: Our results suggested that K. parviflora might be used as a novel therapeutic strategy for psychiatric disorder and cognitive enhancement. However, further investigations about precise underlying mechanism are still required.

  10. Modulation of function of multidrug resistance associated-proteins by Kaempferia parviflora extracts and their components.

    Science.gov (United States)

    Patanasethanont, Denpong; Nagai, Junya; Matsuura, Chie; Fukui, Kyoko; Sutthanut, Khaetthareeya; Sripanidkulchai, Bung-orn; Yumoto, Ryoko; Takano, Mikihisa

    2007-07-02

    In this study, the effects of extracts and flavone derivatives from the rhizome of Kaempferia parviflora on multidrug resistance associated-proteins (MRP)-mediated transport in A549 cells were examined. The cells employed express MRP1 and MRP2, but not P-glycoprotein. The cellular accumulation of calcein, an MRP substrate, was significantly increased by various MRP inhibitors without being affected by verapamil, a typical P-glycoprotein inhibitor. Ethanol and aqueous extracts from K. parviflora rhizome increased the accumulation of calcein and doxorubicin in A549 cells in a concentration-dependent manner. The inhibitory potency of the ethanol extract for MRP function was greater than that of the aqueous extract. Among six flavone derivatives isolated from K. parviflora rhizome, 5,7-dimethoxyflavone exhibited a maximal stimulatory effect on the accumulation of doxorubicin in A549 cells. The accumulation of doxorubicin was increased by four flavone derivatives without 5-hydroxy group, but not by the other two flavone derivatives with 5-hydroxy group. In addition, 5,7-dimethoxyflavone and 3,5,7,3',4'-pentamethoxyflavone decreased resistance to doxorubicin in A549 cells. These findings indicate that extracts and flavone derivatives from the rhizome of K. parviflora suppress MRP function, and therefore may be useful as modulators of multidrug resistance in cancer cells.

  11. Antimicrobial activity of the ethanol extract and compounds from the rhizomes of Kaempferia parviflora

    Directory of Open Access Journals (Sweden)

    Sopa Kummee

    2008-07-01

    Full Text Available The antimicrobial activity of the ethanol extract of Kaempferia parviflora was tested against human pathogens,including bacteria, yeast and dermatophyte fungi, using the agar disc diffusion. The ethanol extract exhibited strong antifungalactivity against dermatophytes with clear zone values from 10.7-19.8 mm at concentration of 2 mg/disc. However,ethanol extract showed no activities against all bacteria and yeast tested. The ethanol extract and seven compounds of K.parviflora were further studied using agar dilution method against dermatophytes. It was found that the ethanol extract of K.parviflora exhibited strong anti-fungal activity against Trichophyton rubrum, Trichophyton mentagrophytes and Microsporumgypseum with MIC values of 62.5, 125 and 250 mg/ml, respectively. Only compound 6 (3, 5, 7-trimethoxyflavone present inthis extract showed appreciable anti-fungal activity with MIC values of 250 mg/ml against these three dermatophytes.According to the obtained results, compound 6 could be responsible only in part of the antifungal effect of theEtOH extract. The antifungal activity of the EtOH extract of K. parviflora supports its traditional use for the treatment ofdermatophyte infections

  12. Structures of two new phenolic glycosides, kaempferiaosides A and B, and hepatoprotective constituents from the rhizomes of Kaempferia parviflora.

    Science.gov (United States)

    Chaipech, Saowanee; Morikawa, Toshio; Ninomiya, Kiyofumi; Yoshikawa, Masayuki; Pongpiriyadacha, Yutana; Hayakawa, Takao; Muraoka, Osamu

    2012-01-01

    Two new phenolic glycosides, kaempferiaosides A and B were isolated from the rhizomes of Kaempferia parviflora (Zingiberaceae) together with 24 known compounds. Their structures including absolute stereochemistry were elucidated on the basis of chemical and spectroscopic evidence. Among the isolates, 5,3'-dihydroxy-3,7,4'-trimethoxyflavone showed higher activity than silybin, a commercial hepatoprotective agent.

  13. No effect of acute ingestion of Thai ginseng (Kaempferia parviflora) on sprint and endurance exercise performance in humans.

    Science.gov (United States)

    Wasuntarawat, Chanchira; Pengnet, Sirinat; Walaikavinan, Nutchanon; Kamkaew, Natakorn; Bualoang, Tippaporn; Toskulkao, Chaivat; McConell, Glenn

    2010-09-01

    Thai ginseng, Kaempferia parviflora, is widely believed among the Mong hill tribe to reduce perceived effort and improve physical work capacity. Kaempferia parviflora is consumed before their daily work. Therefore, we conducted an acute study on the effects of K. parviflora on repeated bouts of sprint exercise and on endurance exercise time to exhaustion. Two studies were conducted in college males using a randomized, double-blind, crossover design. Ninety minutes after consumption of K. parviflora or a starch placebo, participants in study 1 (n = 19) completed three consecutive maximum 30-s sprint cycling Wingate tests, separated by 3 min recovery, while participants in study 2 (n = 16) performed submaximal cycling exercise to exhaustion. Peak and mean power output decreased with successive Wingate tests, while percent fatigue and blood lactate concentration increased after the third Wingate test (P parviflora. There was also no effect of K. parviflora on time to exhaustion, rating of perceived exertion or heart rate during submaximal exercise. Our results indicate that acute ingestion of K. parviflora failed to improve exercise performance during repeated sprint exercise or submaximal exercise to exhaustion. However, chronic effects or actions in other populations cannot be excluded.

  14. Effect of Kaempferia parviflora Extract on Physical Fitness of Soccer Players: A Randomized Double-Blind Placebo-Controlled Trial.

    Science.gov (United States)

    Promthep, Kreeta; Eungpinichpong, Wichai; Sripanidkulchai, Bungorn; Chatchawan, Uraiwan

    2015-05-06

    Physical fitness is a fundamental prerequisite for soccer players. Kaempferia parviflora is an herbal plant that has been used in some Asian athletes with the belief that it might prevent fatigue and improve physical fitness. This study aimed to determine the effects of Kaempferia parviflora on the physical fitness of soccer players. Sixty soccer players who routinely trained at a sports school participated in a double-blind placebo-controlled trial and were randomly allocated to the treatment group or the placebo group. The participants in both groups were given either 180 mg of Kaempferia parviflora extract in capsules or a placebo once daily for 12 weeks. Baseline data were collected using the following 6 tests of physical performance: a sit-and-reach test, a hand grip strength test, a back-and-leg strength test, a 40-yard technical test, a 50-metre sprint test, and a cardiorespiratory fitness test. All of the tests were performed every 4 weeks throughout the 12-week study period. The study showed that after treatment with Kaempferia parviflora, the right-hand grip strength was significantly increased at weeks 4, 8, and 12. The left-hand grip strength was significantly increased at week 8. However, the back-and-leg strength, the 40-yard technical test, the sit-and-reach test, the 50-metre sprint test, and the cardiorespiratory fitness test results of the treatment group were not significantly different from those of the placebo group. Taking Kaempferia parviflora supplements for 12 weeks may significantly enhance some physical fitness components in soccer players.

  15. Potent SIRT1 enzyme-stimulating and anti-glycation activities of polymethoxyflavonoids from Kaempferia parviflora.

    Science.gov (United States)

    Nakata, Asami; Koike, Yuka; Matsui, Hirofumi; Shimadad, Tsutomu; Aburada, Masaki; Yang, Jinwei

    2014-09-01

    The SIRT1 enzyme-stimulating and anti-glycation activities of Kaempferia parviflora extract and its main polymethoxyflavonoids were evaluated in vitro. K. parviflora extract elevated SIRT1 catalytic activity by eight- and 17-fold at 20 μg/mL and 100 μg/mL, respectively, compared with vehicle only. Two major polymethoxyflavonoids, 3,5,7,3',4'-pentamethoxyflavone (4) and 5,7,4'-trimethoxyflavone (5), were isolated from this extract and are four- and fivefold more potent than resveratrol, hitherto the strongest known natural SIRT1 activator. In addition, the anti-glycation activity of K. parviflora extract was observed to be seven times more effective than aminoguanidine, a clinical anti-diabetes drug. 3,5,7,3',4'-Pentamethoxyflavone (4) and 5,7,4'-trimethoxyflavone (5) showed the strongest anti-glycation activity among the tested polymethoxyflavonoids. Further comparison of the activity of these structurally related polymethoxyflavonoids revealed a possible structure-activity relationship, in particular, for the contribution of methoxy moieties.

  16. Preventive effect of Kaempferia parviflora ethyl acetate extract and its major components polymethoxyflavonoid on metabolic diseases.

    Science.gov (United States)

    Shimada, Tsutomu; Horikawa, Takumi; Ikeya, Yukinobu; Matsuo, Hirotaka; Kinoshita, Kaoru; Taguchi, Takaaki; Ichinose, Koji; Takahashi, Kunio; Aburada, Masaki

    2011-12-01

    Previously, we reported that rhizome powder of Kaempferia parviflora Wall. Ex. Baker prevented obesity and a range of metabolic diseases. In this study, to clarify which molecular mechanisms and active ingredients of K. parviflora have an anti-obesity effect, we investigated the effect of ethyl acetate extract of K. parviflora (KPE) on TSOD mice, a spontaneously obese Type II diabetes model, and on pancreatic lipase. In the TSOD groups, KPE showed a suppressive effect on body weight increase and visceral fat accumulation and also showed preventive effects on symptoms related to insulin resistance, hypertension and fatty liver. In addition, KPE also suppressed body weight increase and food intake in TSNO mice groups, which served as reference animals, at an early stage of administration. Searching for the ingredients in KPE revealed that KPE contains at least 12 kinds of polymethoxyflavonoid (PMF). Furthermore, KPE and its component PMFs showed an inhibitory effect on pancreatic lipase. The above results suggest that KPE has a preventive effect on obesity and various metabolic diseases. The mechanisms of action probably involve inhibition of pancreatic lipase by the PMFs in KPE. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Transdermal permeation of Kaempferia parviflora methoxyflavones from isopropyl myristate-based vehicles.

    Science.gov (United States)

    Tuntiyasawasdikul, Sarunya; Limpongsa, Ekapol; Jaipakdee, Napaphak; Sripanidkulchai, Bungorn

    2014-08-01

    Kaempferia parviflora (K. parviflora) rhizomes have long been used in traditional folk medicines and as general health-promoting agents. Several biological activities of K. parviflora, especially its anti-inflammatory effect, are due to its major constituents, methoxyflavones. However, the oral bioavailability of these methoxyflavones has been shown to be low. The aim of this study was to investigate the permeation behaviors of K. parviflora methoxyflavones from isopropyl myristate (IPM)-based vehicles. We studied the effects of ethanol and propylene glycol (PG) as the hydrophilic, solvent-type vehicles as well as fatty acids as the permeation enhancers. A permeation experiment was performed in vitro, using side-by-side diffusion cells through the full thickness of pig ear skin. The solubility and permeation of methoxyflavones were able to be modified by choice and ratio of vehicles. The ethanol/IPM vehicle was shown to be more effective in enhancing the solubility and permeation of methoxyflavones when compared to the PG/IPM vehicle. Regarding an optimal balance between solubility or affinity to vehicle and skin to vehicle partition coefficient, the ethanol/IPM vehicle in the ratio of 1:9 maximized the flux. Among the investigated fatty acids, oleic acid showed the greatest enhancing effect on the permeation of methoxyflavones, indicating that saturated fatty acids are less effective than unsaturated fatty acids. Long chain fatty acids increased diffusion coefficient parameter and shortened the lag time. The number of carbon atoms and double bonds of fatty acids did not show direct relation to the profile of permeation of methoxyflavones.

  18. Immunotoxicity activity of sesquiterpenoids from black galingale (Kaempferia parviflora Wall. Ex. Baker) against Aedes aegypti L.

    Science.gov (United States)

    Moon, Hyung-In; Cho, Sang-Buem; Lee, Jun-Hyeong; Paik, Hyun-Dong; Kim, Soo-Ki

    2011-06-01

    The roots of black galingale (Kaempferia parviflora) were chloroform-extracted and the isolated two sesquiterpene and immunotoxicity effects were studied. The structures and stereochemistry of these compounds were established on the basis of analysis of spectra including UV, MS, (1)H-NMR, and (13)C-NMR as follows: 1 (4α-acetoxycadina-2,9-diene-1,8-dione), 2 (1α,3α,4β-trihydroxy-9-cadinen-8-one). Compound 2 had a significant toxic effect against early fourth-stage larvae of Aedes aegypti L. with an LC(50) value of 0.7 μM and an LC(90) value of 3.8 μM. The results could be useful in search for newer, safer, and more effective natural immunotoxicity agents against A. aegypti.

  19. Structural modification of 5,7-dimethoxyflavone from Kaempferia parviflora and biological activities.

    Science.gov (United States)

    Yenjai, Chavi; Wanich, Suchana; Pitchuanchom, Siripit; Sripanidkulchai, Bungon

    2009-09-01

    5,7-Dimethoxyflavone, a major compound from Kaempferia parviflora, was used as a starting material for structural modification. Seven flavonoid derivatives have been synthesized from this flavone. Two new oxime derivatives 4 and 6 exhibited cytotoxicity against HepG2 cell line with IC50 values of 36.38 and 25.34 microg/mL, respectively, and against T47D cell line with IC50 values of 41.66 and 22.94 microg/mL, respectively. Compound 7 showed cytotoxicity against HepG2 and T47D cell lines with IC50 values of 21.36 and 25.00 microg/mL, respectively. Compounds 6 and 7 showed cytotoxicity nearly equal to the tamoxifen standard. In addition, oxime 6 exhibited antifungal activity against Candida albicans with an IC50 value of 48.98 microg/mL.

  20. Effects of Kaempferia parviflora rhizomes dichloromethane extract on vascular functions in middle-aged male rat.

    Science.gov (United States)

    Yorsin, Somruedee; Kanokwiroon, Kanyanatt; Radenahmad, Nisaudah; Jansakul, Chaweewan

    2014-10-28

    In Thai traditional medicine, rhizomes of Kaempferia parviflora (KP) have been used for treating hypertension and for the promotion of longevity with good health and well being. Ageing is one of the most important risk factors for development of cardiovascular disease. To investigate whether a 6 weeks oral administration of a dichloromethane extract of fresh rhizomes of Kaempferia parviflora (KPD) had any effects on vascular functions, on the accumulation of lipid, as well as on any signs of gross organ toxicity in middle-aged rats. Fresh rhizomes of Kaempferia parviflora were first macerated twice with 95% ethanol to remove the dark color before extracting three times with 100% dichloromethane. The dichloromethane extract was evaporated under reduced pressure to obtain the dried Kaempferia parviflora dichloromethane extract (KPD). The rats were orally administered with the KPD at a dosage of 100mg/kg body weight, or with the same volume of the vehicle (tween 80, 0.2g: carboxy-methylcellulose sodium, 0.2g: distilled water 10 ml) once or twice a day for 6 weeks. Vascular functions were studied on isolated thoracic aorta and the mesenteric artery. The vascular eNOS enzyme was measured by Western blot analysis. Blood chemistry was measured by enzymatic methods. Liver cell lipid accumulation was measured using oil red O staining. A 6 weeks treatment of KPD once a day had no significant effects on any of the studied parameters. When the KPD was given twice a day, the contractile responses to phenylephrine of the thoracic aorta and mesenteric artery were lower than the vehicle control group, and this effect was abolished by N(G)-nitro-l-arginine or by removal of the vascular endothelium. Vasorelaxation to acetylcholine, but not to glyceryl trinitrate, by the thoracic aortic and mesenteric ring precontracted with phenylephrine was higher from the KPD treated rats than those from the vehicle control groups. Western blot analysis showed a higher quantity of thoracic- and

  1. Cytotoxicity against KB and NCI-H187 cell lines of modified flavonoids from Kaempferia parviflora.

    Science.gov (United States)

    Yenjai, Chavi; Wanich, Suchana

    2010-05-01

    Flavones 1-4 isolated from Kaempferia parviflora were used for structural modification. Sixteen flavonoid derivatives, including four new derivatives, were synthesized and evaluated for cytotoxicity against KB and NCI-H187 cell lines. Flavanones 2a-4a demonstrated higher cytotoxic activity than the parent compounds. Cytotoxicity against KB cell line of oxime 1c was about 7 times higher than the ellipticine standard. Interestingly, oximes 1c and 2c exhibited highly potent cytotoxicity against NCI-H187 cell line with IC(50) values of 0.014 and 0.23 microM, respectively. Oximes 4c and 5c showed strong cytotoxicity against NCI-H187 cell line with IC(50) values of 4.04 and 2.32 microM, respectively. 2010 Elsevier Ltd. All rights reserved.

  2. Kaempferia parviflora ethanolic extract promoted nitric oxide production in human umbilical vein endothelial cells.

    Science.gov (United States)

    Wattanapitayakul, Suvara K; Suwatronnakorn, Maneewan; Chularojmontri, Linda; Herunsalee, Angkana; Niumsakul, Somchit; Charuchongkolwongse, Suphan; Chansuvanich, Nuchattra

    2007-04-04

    The rhizomes of Kaempferia parviflora (KP) (Zingiberaceae) have been used in Thai traditional medicine for health promotion and for the treatment of digestive disorders and gastric ulcer. This study investigated effect of KP on endothelial function. Studies in human umbilical vein endothelial cells (HUVEC) showed that KP dose-dependently increased nitrite concentrations in culture media after 48 h incubation. eNOS mRNA and protein expression were also enhanced. The induction of eNOS mRNA was detected at 4 h and plateau at 48 h while iNOS expression was not observed. These data demonstrate that KP has a great potential for a supplemental use in vascular endothelial health promotion.

  3. Amino and nitro derivatives of 5,7-dimethoxyflavone from Kaempferia parviflora and cytotoxicity against KB cell line.

    Science.gov (United States)

    Wanich, Suchana; Yenjai, Chavi

    2009-09-01

    Structural modification of 5,7-dimethoxyflavone isolated from Kaempferia parviflora furnished two nitro and seven amino derivatives. Among these, six new (3, 5-6, 8-10) and three known (2, 4, 7) flavonoid derivatives were synthesized. All compounds were evaluated for cytotoxicity against KB cell line using colorimetric method. Compounds 6 and 8 exhibited strong cytotoxicity with IC50 values of 6.80 and 5.84 microg/mL, respectively.

  4. Kaempferia parviflora extract increases energy consumption through activation of BAT in mice.

    Science.gov (United States)

    Yoshino, Susumu; Kim, Minji; Awa, Riyo; Kuwahara, Hiroshige; Kano, Yuriko; Kawada, Teruo

    2014-11-01

    Kaempferia parviflora (KP) is a member of the ginger family and is known in Thailand as Thai ginseng, Krachai Dam or Black Ginger. TheK. parviflora extract (KPE) was previously reported to have a number of physiological effects; however, the antiobesity effects of KPE and its mechanisms remain to be elucidated. In this study, we conducted KPE feeding experiments (low dose: 0.5% KPE, high dose: 1.0% KPE) in mice to examine the antiobesity effects. For both 0.5% KPE and 1.0% KPE, 7 weeks' feeding of KPE contained in a high-fat diet (HFD) significantly decreased body weight gain, intraabdominal fat accumulation, and plasma triglyceride and leptin levels. Concurrently, KPE administration increased oxygen consumption in mice fed on a HFD. We also found that 1.0% KPE feeding significantly increased the uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT). Moreover, KPE administration increased urinary noradrenaline secretion levels. These results demonstrate that KPE promotes energy metabolism by activation of BAT, at both doses and up-regulation of UCP1 protein at a high dose. Although numerous challenges remain, the present study demonstrated that KPE suppresses HFD-induced obesity through increased energy metabolism.

  5. Identification and evaluation of anti-inflammatory compounds from Kaempferia parviflora.

    Science.gov (United States)

    Horigome, Satoru; Yoshida, Izumi; Tsuda, Aiko; Harada, Teppei; Yamaguchi, Akihiro; Yamazaki, Kumiko; Inohana, Shuichi; Isagawa, Satoshi; Kibune, Nobuyuki; Satoyama, Toshiya; Katsuda, Shin-ichi; Suzuki, Shinobu; Watai, Masatoshi; Hirose, Naoto; Mitsue, Takahiro; Shirakawa, Hitoshi; Komai, Michio

    2014-01-01

    The rhizome of Kaempferia parviflora has been used in traditional Thai medicine. In this study, we identified and compared specific compounds from the hexane extract of K. parviflora with those from other Zingiberaceous plants by using gas chromatography-mass spectrometry. We identified 5,7-dimethoxyflavone (DMF), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (TMF), estimated 3,5,7-trimethoxyflavone, 5-hydroxy-7,4'-dimethoxyflavone, 3,5,7,4'-tetramethoxyflavone, and investigated their anti-inflammatory effects in rat basophilic leukemia (RBL-2H3) cells stimulated with an IgE antigen or a calcium ionophore. We found that DMF and TMF more potently inhibited antigen-induced degranulation than did nobiletin, a well-known anti-inflammatory agent. In addition, compared to RBL-2H3 cells stimulated with a calcium ionophore, those treated with DMF and TMF showed more marked inhibition of the degranulation and the production and mRNA expression of inflammatory mediators. These results suggest that DMF and TMF inhibit an early step in the high-affinity IgE receptor signaling cascade rather than intracellular calcium release and protein kinase C activation.

  6. The effects of Kaempferia parviflora on anti- internalization activity of ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... proton pump inhibitor (PPI) and two antibiotics of. *Corresponding ... transmission electron microscope revealed spiral H. pylori in the gastric lumen and ..... The close relationship between the elevated invading efficiency and ...

  7. Kaempferia parviflora Extract Exhibits Anti-cancer Activity against HeLa Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Saranyapin Potikanond

    2017-09-01

    Full Text Available Kaempferia parviflora (KP has been traditionally used as a folk remedy to treat several diseases including cancer, and several studies have reported cytotoxic activities of extracts of KP against a number of different cancer cell lines. However, many aspects of the molecular mechanism of action of KP remain unclear. In particular, the ability of KP to regulate cancer cell growth and survival signaling is still largely unexplored. The current study aimed to investigate the effects of KP on cell viability, cell migration, cell invasion, cell apoptosis, and on signaling pathways related to growth and survival of cervical cancer cells, HeLa. We discovered that KP reduced HeLa cell viability in a concentration-dependent manner. The potent cytotoxicity of KP against HeLa cells was associated with a dose-dependent induction of apoptotic cell death as determined by flow cytometry and observation of nuclear fragmentation. Moreover, KP-induced cell apoptosis was likely to be mediated through the intrinsic apoptosis pathway since caspase 9 and caspase 7, but not BID, were shown to be activated after KP exposure. Based on the observation that KP induced apoptosis in HeLa cell, we further investigated the effects of KP at non-cytotoxic concentrations on suppressing signal transduction pathways relevant to cell growth and survival. We found that KP suppressed the MAPK and PI3K/AKT signaling pathways in cells activated with EGF, as observed by a significant decrease in phosphorylation of ERK1/2, Elk1, PI3K, and AKT. The data suggest that KP interferes with the growth and survival of HeLa cells. Consistent with the inhibitory effect on EGF-stimulated signaling, KP potently suppressed the migration of HeLa cells. Concomitantly, KP was demonstrated to markedly inhibit HeLa cell invasion. The ability of KP in suppressing the migration and invasion of HeLa cells was associated with the suppression of matrix metalloproteinase-2 production. These data strongly

  8. Kaempferia parviflora Extract Exhibits Anti-cancer Activity against HeLa Cervical Cancer Cells.

    Science.gov (United States)

    Potikanond, Saranyapin; Sookkhee, Siriwoot; Na Takuathung, Mingkwan; Mungkornasawakul, Pitchaya; Wikan, Nitwara; Smith, Duncan R; Nimlamool, Wutigri

    2017-01-01

    Kaempferia parviflora (KP) has been traditionally used as a folk remedy to treat several diseases including cancer, and several studies have reported cytotoxic activities of extracts of KP against a number of different cancer cell lines. However, many aspects of the molecular mechanism of action of KP remain unclear. In particular, the ability of KP to regulate cancer cell growth and survival signaling is still largely unexplored. The current study aimed to investigate the effects of KP on cell viability, cell migration, cell invasion, cell apoptosis, and on signaling pathways related to growth and survival of cervical cancer cells, HeLa. We discovered that KP reduced HeLa cell viability in a concentration-dependent manner. The potent cytotoxicity of KP against HeLa cells was associated with a dose-dependent induction of apoptotic cell death as determined by flow cytometry and observation of nuclear fragmentation. Moreover, KP-induced cell apoptosis was likely to be mediated through the intrinsic apoptosis pathway since caspase 9 and caspase 7, but not BID, were shown to be activated after KP exposure. Based on the observation that KP induced apoptosis in HeLa cell, we further investigated the effects of KP at non-cytotoxic concentrations on suppressing signal transduction pathways relevant to cell growth and survival. We found that KP suppressed the MAPK and PI3K/AKT signaling pathways in cells activated with EGF, as observed by a significant decrease in phosphorylation of ERK1/2, Elk1, PI3K, and AKT. The data suggest that KP interferes with the growth and survival of HeLa cells. Consistent with the inhibitory effect on EGF-stimulated signaling, KP potently suppressed the migration of HeLa cells. Concomitantly, KP was demonstrated to markedly inhibit HeLa cell invasion. The ability of KP in suppressing the migration and invasion of HeLa cells was associated with the suppression of matrix metalloproteinase-2 production. These data strongly suggest that KP may slow

  9. Kaempferia parviflora extract ameliorates the cognitive impairments and the reduction in cell proliferation induced by valproic acid treatment in rats.

    Science.gov (United States)

    Welbat, Jariya Umka; Chaisawang, Pornthip; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanun; Sripanidkulchai, Bungorn; Wigmore, Peter

    2016-07-01

    Kaempferia parviflora is a herbal plant whose rhizomes are used in traditional medicine. Investigations of this plant have shown it to have antidepressant activity and to improve learning and memory in animal models. The aim of the present investigation was to determine whether K. parviflora could protect the brain from the impairments in cognition and hippocampal neurogenesis which are caused by valproic acid (VPA). Male Sprague Dawley rats (180-200g) were given once daily K. parviflora extract (100mg/kg) via oral gavage for 21 days. Rats received twice daily intraperitoneal injections of valproic acid (300mg/kg) from days 8 to 21 of the experiment. Spatial memory was tested using the novel object location (NOL) test five days after the end of treatment. Cell proliferation in the sub granular zone (SGZ) of the dentate gyrus was quantified by immunohistochemistry and levels of doublecortin (DCX) were determined by Western blotting. Co-treatment of VPA and K. parviflora prevented the cognitive decline and reduction in proliferating cells caused by VPA. Furthermore, co-treatment significantly increased DCX protein levels within the hippocampus. These findings demonstrate that K. parviflora is able to prevent the brain from VPA-induced the impairments of spatial memory and proliferating cells within the SGZ. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. A monolithic drug-in-adhesive patch of methoxyflavones from Kaempferia parviflora: in vitro and in vivo evaluation.

    Science.gov (United States)

    Tuntiyasawasdikul, Sarunya; Limpongsa, Ekapol; Jaipakdee, Napaphak; Sripanidkulchai, Bungorn

    2015-01-30

    The aim of this study was to design and develop a suitable monolithic drug-in-adhesive type patch of methoxyflavones from Kaempferia parviflora (K. parviflora) using acrylic polymer Durotak(®) 87-2852. The absence of interaction between components in K. parviflora extract and the adhesive polymer was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Thirteen K. parviflora patches with different extract loading and permeation enhancers were prepared by the solvent evaporation technique. All formulations showed good physicochemical properties, good stability and satisfactory adhesive properties. The effect of K. parviflora loading and permeation enhancers on methoxyflavones transport across porcine ear skin was also evaluated. The permeation of methoxyflavones increased with the amount of K. parviflora. Among the permeation enhancers investigated, oleic acid increased permeation flux of total methoxyflavones by 1.25 fold compared to the control; whereas menthol shortened the lag time. When oleic acid and menthol were combined, the maximum flux of methoxyflavones and shortest lag time were observed, suggesting a synergistic effect of menthol with oleic acid. The optimal patch formulation contained 15% K. parviflora, 3% oleic acid and 3% of menthol, and this was evaluated via an in vivo pharmacokinetic study using rats. The maximum plasma drug concentration (Cmax) of total methoxyflavones was 218.08ng/ml with Tmax at 8h. The concentrations of methoxyflavones in plasma continued to increase until the end of the experiment, indicating a sustained release into the systemic circulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Antiobesity effects of Kaempferia parviflora in spontaneously obese type II diabetic mice.

    Science.gov (United States)

    Akase, Tomoko; Shimada, Tsutomu; Terabayashi, Susumu; Ikeya, Yukinobu; Sanada, Hiromi; Aburada, Masaki

    2011-01-01

    Kaempferia parviflora Wall. Ex Baker (KP) has been used as a folk medicine in Laos and Thailand to lower blood glucose levels, improve blood flow, and increase vitality. This study investigated the preventive effects of KP on obesity and its downstream symptoms (various metabolic disorders) using Tsumura, Suzuki, Obese Diabetes (TSOD) mice, a multifactorial genetic disease animal model in which metabolic diseases develop spontaneously, similar to metabolic syndrome in humans, and Tsumura, Suzuki, Non-Obesity (TSNO) mice as the corresponding control mice. When feed that was mixed with KP (1 or 3%) was given ad libitum to TSOD and TSNO mice for 8 weeks, body weight increase, visceral fat accumulation, lipid metabolism abnormalities, hyperinsulinemia, glucose intolerance, insulin resistance, hypertension, and peripheral neuropathy were suppressed in TSOD mice, but no marked differences were observed in TSNO mice. Because KP had preventive effects on metabolic diseases, including antiobesity effects, only in obese animals, we propose that KP will be extremely valuable as a medicine or component of food in alternative health care.

  12. Enhancement of aphrodisiac activity in male rats by ethanol extract of Kaempferia parviflora and exercise training.

    Science.gov (United States)

    Chaturapanich, G; Chaiyakul, S; Verawatnapakul, V; Yimlamai, T; Pholpramool, C

    2012-05-01

    This study aimed to investigate the effects of Kaempferia parviflora extract (KD) and exercise training on reproductive function in male rats. Sexually mature males were assigned to four groups: control, KD70 (received 70 mg kg(-1) day(-1) for 4 weeks), Ex (exercise training for 4 weeks), Ex + KD70 (exercise training with KD 70 mg kg(-1) day(-1)). At the end of treatment regimes, sexual behaviours including mount latency (ML), mount frequency (MF), ejaculation latency (EL), post-ejaculation latency (PEL), number of mount within 30 min (MF(30)) and number of ejaculation (NEL) were assessed by a video camera, and fertility was tested by natural mating. Results showed that KD had no effect on the weights of reproductive organs, liver, kidneys and levator ani muscle. On the other hand, the weights of epididymis, seminal vesicles, prostate gland and levator ani muscle were significantly increased in the Ex and Ex+KD70 groups. ML and EL were shortened in all treatment groups, but PEL was decreased only in KP70 group. Only Ex and Ex + KD70 groups exhibited lower MF and higher NEL whilst MF(30) were not changed in all groups. None of the treatments altered male fertility. It is concluded that KD enhanced sexual motivation whereas exercise training promoted both sexual motivation and performance. © 2011 Blackwell Verlag GmbH.

  13. Xanthine oxidase inhibitory activities and crystal structures of methoxyflavones from Kaempferia parviflora rhizome.

    Science.gov (United States)

    Nakao, Kikuyo; Murata, Kazuya; Deguchi, Takahiro; Itoh, Kimihisa; Fujita, Takanori; Higashino, Masayuki; Yoshioka, Yuri; Matsumura, Shin-Ichi; Tanaka, Rika; Shinada, Tetsuro; Ohfune, Yasufumi; Matsuda, Hideaki

    2011-01-01

    Kaempferia parviflora (KP), a Zingiberaceae plant, is used as a folk medicine in Thailand for the treatment of various symptoms, including general pains, colic gastrointestinal disorders, and male impotence. In this study, the inhibitory activities of KP against xanthine oxidase (XOD) were investigated. The extract of KP rhizomes showed more potent inhibitory activity (38% at 500 µg/ml) than those of the other Zingiberaceae plants tested. Ten methoxyflavones were isolated from the KP extract as the major chemical components and their chemical structures were elucidated by X-ray crystallography. The structurally confirmed methoxyflavones were subjected to the XOD inhibitory test. Among them, 3,5,7,4',5'-pentamethoxyflavone and 3',4',5,7-tetramethoxyflavone showed inhibitory activities (IC(50) of 0.9 and >4 mM, respectively) and their modes of inhibition are clarified as competitive/non-competitive mixed type. To the best of our knowledge, this is the first report to present the inhibitory activities of KP, 3,5,7,4',5'-pentamethoxyflavone and 3',4',5,7-tetramethoxyflavone against XOD.

  14. Effect of Kaempferia parviflora on sexual performance in streptozotocin-induced diabetic male rats.

    Science.gov (United States)

    Lert-Amornpat, T; Maketon, C; Fungfuang, W

    2017-03-10

    Kaempferia parviflora Wall. Ex.Baker or Krachidum (KP) has been used locally in medicine and food. It has been claimed that KP has aphrodisia properties; however, no scientific data in support of this function in diabetic model have been reported. This study aimed to investigate the efficacy of KP on sexual behaviour and sperm parameter in streptozotocin (STZ)-induced diabetic male rats. Diabetes was induced in twenty male rats by STZ and divided into four groups: diabetic control group, and 3 treatment groups where KP was dose at 140, 280 and 420 mg/kg orally once a day for 6 weeks. Five normal control rats were treated with vehicle. The body weight, blood glucose, food intake, epididymal sperm parameter, sexual behaviour and serum testosterone level were evaluated. The results showed that KP treatment has no effect on the body weight, blood glucose and food intake in diabetic rats. A significant increase in sperm density in diabetic rats was observed (p < .05) at highest dose of KP. Furthermore, KP treatment demonstrated a significant recovery of sexual behaviour and serum testosterone levels in diabetic rats. These results confirm that KP exhibits aphrodisiac properties that improve the sperm density, testosterone level and sexual performance of STZ-induced diabetic rats. © 2017 The Authors. Andrologia Published by Blackwell Verlag GmbH.

  15. Inhibition of viral proteases by Zingiberaceae extracts and flavones isolated from Kaempferia parviflora.

    Science.gov (United States)

    Sookkongwaree, K; Geitmann, M; Roengsumran, S; Petsom, A; Danielson, U H

    2006-08-01

    In order to identify novel lead compounds with antiviral effect, methanol and aqueous extracts of eight medicinal plants in the Zingiberaceae family were screened for inhibition of proteases from human immunodeficiency virus type 1 (HIV-1), hepatitis C virus (HCV) and human cytomegalovirus (HCMV). In general, the methanol extracts inhibited the enzymes more effectively than the aqueous extracts. HIV-1 protease was strongly inhibited by the methanol extract of Alpinia galanga. This extract also inhibited HCV and HCMV proteases, but to a lower degree. HCV protease was most efficiently inhibited by the extracts from Zingiber officinale, with little difference between the aqueous and the methanol extracts. Many of the methanol extracts inhibited HCMV protease, but the aqueous extracts showed weak inhibition. In a first endeavor to identify the active constituents, eight flavones were isolated from the black rhizomes of Kaempferia parviflora. The most effective inhibitors, 5-hydroxy-7-methoxyflavone and 5,7-dimethoxyflavone, inhibited HIV-1 protease with IC50 values of 19 microM. Moreover, 5-hydroxy-3,7-dimethoxyflavone inhibited HCV protease and HCMV protease with IC50 values of 190 and 250 microM, respectively.

  16. Kaempferia parviflora extract increases whole-body energy expenditure in humans: roles of brown adipose tissue.

    Science.gov (United States)

    Matsushita, Mami; Yoneshiro, Takeshi; Aita, Sayuri; Kamiya, Tomoyasu; Kusaba, Nobutaka; Yamaguchi, Kazuya; Takagaki, Kinya; Kameya, Toshimitsu; Sugie, Hiroki; Saito, Masayuki

    2015-01-01

    Kaempferia parviflora extract (KP) has been reported to have a preventive effect on obesity in mice, probably by increasing energy expenditure (EE). The aims of the current study were to examine the acute effects of KP ingestion on whole-body EE in humans and to analyze its relation to the activity of brown adipose tissue (BAT), a site of non-shivering thermogenesis. After an oral ingestion of an ethanol extract of KP, EE increased significantly, showing a maximal increase of 229±69 kJ/d at 60 min, while it did not change after placebo ingestion. To evaluate BAT activity, the subjects underwent fluorodeoxyglucose-positron emission tomography, and divided into two groups with high- and low-BAT activities. A similar and greater response of EE to KP ingestion was observed in the high-BAT group (351±50 kJ/d at 60 min), but not in the low activity group. Placebo ingestion did not cause any significant EE change in either group. These results indicate that a single oral ingestion of the KP extract can potentially increase whole-body EE probably through the activation of BAT in healthy men, and may be useful as an anti-obesity regimen.

  17. Effects of Kaempferia parviflora Wall. Ex. Baker on electrophysiology of the swine hearts.

    Science.gov (United States)

    Weerateerangkul, Punate; Surinkaew, Sirirat; Chattipakorn, Siriporn C; Chattipakorn, Nipon

    2013-01-01

    Pre-clinical studies in swine have demonstrated that a supratherapeutic concentration of sildenafil citrate decreased defibrillation efficacy and facilitated cardiac arrhythmia. We therefore, decided to investigate the effects of Kaempferia parviflora (KP) extract on these parameters in the swine heart. The underlying assumption was that in the heart, KP might be producing effects similar to sildanafil citrate as KP has long been used in southeast Asian traditional medicine to correct erectile dysfunction. The study was conducted as the defibrillation study, and ventricular fibrillation (VF) induction study. In both studies, the defibrillation threshold (DFT), the upper limit of vulnerability (ULV) and VF threshold were determined before and after KP extract administration. In both studies KP extract at high concentrations (100 and 50 mg/kg) significantly increased the DFT and ULV, without altering the VF threshold. At these concentrations, systolic and diastolic blood pressures were also attenuated. High concentrations of KP extract attenuated defibrillation efficacy and increased cardiac vulnerability to arrhythmia in a normal swine heart. When used in appropriate concentrations, its blood pressure lowering effect may be useful in hypertensive states. Further studies need to be done to elucidate its mechanism of action.

  18. New flav-3-en-3-ol glycosides, kaempferiaosides C and D, and acetophenone glycosides, kaempferiaosides E and F, from the rhizomes of Kaempferia parviflora.

    Science.gov (United States)

    Chaipech, Saowanee; Morikawa, Toshio; Ninomiya, Kiyofumi; Yoshikawa, Masayuki; Pongpiriyadacha, Yutana; Hayakawa, Takao; Muraoka, Osamu

    2012-07-01

    Two new flav-3-en-3-ol glycosides, kaempferiaosides C (3) and D(4), and two new acetophenone glycosides, kaempferiaosides E (5) and F (6), were isolated from the Thai natural medicine Krachai Dum, the rhizomes of Kaempferia parviflora Wall. ex Baker. Their structures were established mainly on the basis of 1D and 2D NMR spectral data.

  19. EFFICACY ASSESSMENT OF KAEMPFERIA PARVIFLORA FOR THE MANAGEMENT OF ERECTILE DYSFUNCTION

    Directory of Open Access Journals (Sweden)

    Panakaporn Wannanon

    2012-01-01

    Full Text Available Age-related decline in erectile function is a noted phenomenon worldwide. A variety of medicinal plants have been identified as having strong aphrodisiac properties along with the ability to improve erectile functioning. Kaempferia Parviflora (KP has famous as a Thai Viagra and use it to increase male impotency. However, there is limited scientific evidence regarding the efficacy of this herb on this issue in aging healthy men. This study therefore investigated the effect of KP extract administration on erectile response of male elderly volunteers. Total 45 male healthy elderly volunteers will be divided into 3 separated groups including placebo and the different doses of ethanolic extracts of KP (25 and 90 mg once daily at a period of 2 months. The erectile function tests including the response latency time to visual erotic stimuli, size and length of penis both in flaccid and erection states were assessed after single administration, 1 and 2 months of treatment. In order to investigate the possible underlying mechanism, we also determined the alteration of testosterone, FSH and LH concentrations. KP at a dose of 90 mg day-1 treated group exhibited a significant enhanced all parameters after 1 and 2 months of treatment. Moreover, the penile length at erection states and the response latency to sexual erotic stimuli appeared to be the parameters that showed significant changes during the delay period. Unfortunately, our study failed to show the significant changes on hormones concentration. Our study clearly demonstrates that KP is a potential resource for the development of nutraceutical compound against aged related male erectile dysfunction.

  20. Simultaneous identification and quantitation of 11 flavonoid constituents in Kaempferia parviflora by gas chromatography.

    Science.gov (United States)

    Sutthanut, K; Sripanidkulchai, B; Yenjai, C; Jay, M

    2007-03-02

    Kaempferia parviflora (Krachaidum; KD) is a Thai herb, the rhizomes of which have been used in folk medicine and ritual ceremonies. The increasing use of KD has led to concerns regarding the variation of quality, potency and efficacy of KD products. A gas chromatographic method was developed and validated using 11 flavonoids that had been fully characterized as reference. Limits of detection ranged from a low of 0.1 ppm to a high of 1.0 ppm. The limits of quantitation were a low of 0.5 ppm (5-hydroxy-3,7-dimethoxyflavone) to a high of 3.0 ppm (5,7,4'-trimethoxyflavone and 5,7,3',4'-tetramethoxyflavone). Precision of intra- and inter-day analyses gave a RSD range of 3.02-8.25 and 2.84-12.37, respectively. The diversity of flavonoid content and their distribution profiles in KD samples from 12 different origins was investigated using the validated method. Total flavonoid content in these samples ranged from 23.86 to 60.98 mg/g. Two of the compounds, 5,7-dimethoxyflavone and 5,7,4'-trimethoxyflavone, emerged as major constituents. Samples contained as much as 21.68 and 9.88 mg/g, respectively. Two distinct patterns of the distribution of the flavonoids, as characterized by the ratio of these two compounds in the KD rhizome samples, were observed. This method is expected to be useful in the quantitative and qualitative analyses of the flavonoid content of KD samples and as a quality control assessment of KD raw materials and products.

  1. Effects of Kaempferia parviflora extracts on reproductive parameters and spermatic blood flow in male rats.

    Science.gov (United States)

    Chaturapanich, G; Chaiyakul, S; Verawatnapakul, V; Pholpramool, C

    2008-10-01

    Krachaidum (KD, Kaempferia parviflora Wall. Ex. Baker), a native plant of Southeast Asia, is traditionally used to enhance male sexual function. However, only few scientific data in support of this anecdote have been reported. The present study investigated the effects of feeding three different extracts of KD (alcohol, hexane, and water extracts) for 3-5 weeks on the reproductive organs, the aphrodisiac activity, fertility, sperm motility, and blood flow to the testis of male rats. Sexual performances (mount latency, mount frequency, ejaculatory latency, post-ejaculatory latency) and sperm motility were assessed by a video camera and computer-assisted sperm analysis respectively, while blood flow to the testis was measured by a directional pulsed Doppler flowmeter. The results showed that all extracts of KD had virtually no effect on the reproductive organ weights even after 5 weeks. However, administration of the alcohol extract at a dose of 70 mg/kg body weight (BW)/day for 4 weeks significantly decreased mount and ejaculatory latencies when compared with the control. By contrast, hexane and water extracts had no influence on any sexual behavior parameters. All types of extracts of KD had no effect on fertility or sperm motility. On the other hand, alcohol extract produced a significant increase in blood flow to the testis without affecting the heart rate and mean arterial blood pressure. In a separate study, an acute effect of alcohol extract of KD on blood flow to the testis was investigated. Intravenous injection of KD at doses of 10, 20, and 40 mg/kg BW caused dose-dependent increases in blood flow to the testis. The results indicate that alcohol extract of KD had an aphrodisiac activity probably via a marked increase in blood flow to the testis.

  2. Effect of daily treatment with Thai herb, Kaempferia parviflora, in Hershberger assay using castrated immature rats.

    Science.gov (United States)

    Trisomboon, Hataitip; Watanabe, Gen; Wetchasit, Phongphat; Taya, Kazuyoshi

    2007-04-01

    The aim of the present study was to investigate the testosterone-like effect of Kaempferia parviflora (KP). Castrated immature rats were randomized and divided into two groups (control and KP-treatment groups). The rats (n=7-8) were treated daily for 5 days by oral route with water in the control group and 1,000 mg/kg of KP in the treatment group. All rats were decapitated 24 h after their last dose and then blood samples were collected for assay of serum FSH, LH, testosterone, progesterone and corticosterone levels. The seminal vesicles plus coagulating glands, ventral prostate, levator ani muscle plus bulbocavernosus muscle, glans penis, kidneys and the adrenal glands were collected and weighed for organ wet weight. Body weight and weight of food intake were recorded throughout the study period. The results show that relative body weight gain in the KP-treatment group was significantly increased 24 and 48 h after the first dose (P<0.05) and then was indistinguishable from the control group. There were no significant differences in the relative reproductive and non-reproductive organ weights between the groups, although all organ weights, except for the glans penis, tended to increase in the KP-treatment group. The serum testosterone levels were significantly increased in the KP-treatment group. There were no significant differences in the serum FSH, LH, progesterone, or corticosterone levels between the groups, even though the serum progesterone level tended to increase and serum LH level tended to decrease in the KP-treatment group. The present study indicates that KP has no testosterone-like effect on reproduction in male rats.

  3. Pharmacokinetics, bioavailability, tissue distribution, excretion, and metabolite identification of methoxyflavones in Kaempferia parviflora extract in rats.

    Science.gov (United States)

    Mekjaruskul, Catheleeya; Jay, Michael; Sripanidkulchai, Bungorn

    2012-12-01

    Kaempferia parviflora (KP) is an herbal plant in the family of Zingiberaceae. KP mainly contains methoxyflavones, especially 5,7-dimethoxyflavone (DMF), 5,7,4'-trimethoxyflavone (TMF), and 3,5,7,3',4'-pentamethoxyflavone (PMF). The present study was designed to characterize the pharmacokinetics, including bioavailability, distribution, excretion, and identification of metabolites after administration of a KP ethanolic extract. Male rats were orally or intravenously administered a 250 mg/kg concentration of a KP extract, and blood samples were obtained at selected times to determine pharmacokinetic parameters of PMF, TMF, and DMF. For distribution and excretion studies, the organs, urine, and feces samples were collected at various times after oral administration of a larger (750 mg/kg) dose of KP extract. Methoxyflavones in the biological samples were quantified by high-performance liquid chromatography-UV, and the metabolites in urine and feces were further identified by using liquid chromatography-tandem mass spectrometry. After oral administration, concentrations of the three methoxyflavones quickly approached their maximal concentration, ranging from 0.55 to 0.88 μg/ml within 1 to 2 h after administration, and then were gradually excreted with half-lives of 3 to 6 h. The methoxyflavones showed low oral bioavailability of 1 to 4%. Three methoxyflavones were detected at their highest levels in liver followed by kidney. They were also found in lung, testes, and brain. After absorption, organ distribution, and metabolism, the components of KP were mainly eliminated through urine in the forms of demethylated, sulfated, and glucuronidated products and as demethylated metabolites in the feces. The parent compounds were found to have 0.79, 1.76, and 3.10% dose recovery in urine and 1.06, 1.77, and 0.96% dose recovery in feces for PMF, TMF, and DMF, respectively. These studies are the first to describe the pharmacokinetics of KP extract to provide the information on

  4. Possible mechanisms of vasorelaxation for 5,7-dimethoxyflavone from Kaempferia parviflora in the rat aorta.

    Science.gov (United States)

    Tep-Areenan, Patcharin; Sawasdee, Pattara; Randall, Michael

    2010-10-01

    The present study investigated the vascular effects of 5,7-dimethoxyflavone (DMF), isolated from the rhizomes of Kaempferia parviflora (KP), on rat isolated aortic rings and its possible mechanisms. DMF (1-100 μM) caused concentration-dependent relaxations in aortic rings precontracted with methoxamine. This effect was significantly reduced by removal of the endothelium, and after pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 300 μM), indomethacin (10 μM) and 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ, 10 μM), but not 9-(tetrahydro-2-furanyl)-9H-purine-6-amine (SQ22536, 100 μM). Relaxant responses to DMF were significantly inhibited by high KCl (60 mM) in both endothelium-intact and -denuded rings. In addition, the relaxations to DMF were significantly reduced by pretreatment with tetraethylammonium (TEA, 5 mM), glibenclamide (10 μM), 4-aminopyridine (1 mM) or barium chloride (10 μM). Preincubation with DMF (10 and 100 μM) for 30 min significantly inhibited the contractile responses to CaCl(2) in a Ca(2+)-free, high K(+) buffer. The present study demonstrated that DMF causes endothelium-dependent relaxation that is partly mediated by NO-cGMP and cyclooxygenase pathways. Interestingly, DMF-induced responses are mainly due to increasing K(+) efflux, and inhibition of Ca(2+) influx from the extracellular space. The vasodilator effects of DMF provide experimental support for the potential use of KP as a medical plant in the treatment of cardiovascular diseases. Copyright © 2010 John Wiley & Sons, Ltd.

  5. The protective effect of Kaempferia parviflora extract on UVB-induced skin photoaging in hairless mice.

    Science.gov (United States)

    Park, Ji-Eun; Pyun, Hee-Bong; Woo, Seon Wook; Jeong, Jae-Hong; Hwang, Jae-Kwan

    2014-10-01

    Chronic skin exposure to ultraviolet (UV) light increases reactive oxygen species (ROS) and stimulates the expression of matrix metalloproteinases (MMPs) through c-Jun and c-Fos activation. These signaling cascades induce the degradation of extracellular matrix (ECM) components, resulting in photoaging. This study evaluated the preventive effect of the ethanol extract of Kaempferia parviflora Wall. ex. Baker (black ginger) on UVB-induced photoaging in vivo. To investigate the antiphotoaging effect of K. parviflora extract (KPE), UVB-irradiated hairless mice administered oral doses of KPE (100 or 200 mg/kg/day) for 13 weeks. In comparison to the UVB control group, KPE significantly prevented wrinkle formation and the loss of collagen fibers with increased type I, III, and VII collagen genes (COL1A1, COL3A1, and COL7A1). The decrease in wrinkle formation was associated with a significant reduction in the UVB-induced expression of MMP-2, MMP-3, MMP-9, and MMP-13 via the suppression of c-Jun and c-Fos activity. KPE also increased the expression of catalase, which acts as an antioxidant enzyme in skin. In addition, expression of inflammatory mediators, such as nuclear factor kappa B (NF-κB), interleukin-1β (IL-1β), and cyclooxygenase-2 (COX-2), was significantly reduced by KPE treatment. The results show that oral administration of KPE significantly prevents UVB-induced photoaging in hairless mice, suggesting its potential as a natural antiphotoaging material. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Oral administration of Kaempferia parviflora did not disturb male reproduction in rats.

    Science.gov (United States)

    Trisomboon, Hataitip; Tohei, Atsushi; Malaivijitnond, Suchinda; Watanabe, Gen; Taya, Kazuyoshi

    2008-10-01

    To investigate the androgenic effect of Kaempferia parviflora (KP), a Thai herbal plant, adult male rats were randomized into control and KP-treatment groups. Rats were treated orally with water in the control group and with 1,000 mg/kg/day of KP in the treatment group for 45 days. Blood samples were collected on days 10, 20, 30 and 45 for measurement of the serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, progesterone and corticosterone levels. The reproductive and non-reproductive organs were dissected on day 45 and weighed. Mating behavior was also observed on days 20 and 30. Body weight was measured throughout the study period. The results showed that KP induced an increase in body weight compared with the controls. There were no significant differences in the weights of either reproductive (testis, seminal vesicle plus coagulating gland, levator ani muscle plus bulbocarvernosus muscle and glans penis, except the prostate gland) or non-reproductive organs (kidney, adrenal gland and gastracnemius muscle). There were no significant differences in serum levels of either FSH or LH between the two groups. The serum testosterone and progesterone levels were insignificantly lower in the KP group during the first 30 days. The serum corticosterone levels in the KP group were lower than those in the controls throughout the study period and were significantly low on days 20 and 30. There were no significant changes in mating behavior in the rats treated with KP. Although KP affected the body weight and serum corticosterone level, it did not affect mating behavior, reproductive and non-reproductive organ weights or hormones related to the reproductive system in the adult male rats. Therefore, we conclude that the testosterone-like effect of KP did not disturb the hypothalamic-pituitary-testicular axis or male reproduction.

  7. Effects of ethyl acetate extract of Kaempferia parviflora on brown adipose tissue.

    Science.gov (United States)

    Kobayashi, Hiroko; Horiguchi-Babamoto, Emi; Suzuki, Mio; Makihara, Hiroko; Tomozawa, Hiroshi; Tsubata, Masahito; Shimada, Tsutomu; Sugiyama, Kiyoshi; Aburada, Masaki

    2016-01-01

    We have previously reported the effects of Kaempferia parviflora (KP), including anti-obesity, preventing various metabolic diseases, and regulating differentiation of white adipose cells. In this study we used Tsumura, Suzuki, Obese Diabetes (TSOD) mice--an animal model of spontaneous obese type II diabetes--and primary brown preadipocytes to examine the effects of the ethyl acetate extract of KP (KPE) on brown adipose tissue, which is one of the energy expenditure organs. TSOD mice were fed with MF mixed with either KPE 0.3 or 1% for 8 weeks. Computed tomography images showed that whitening of brown adipocytes was suppressed in the interscapular tissue of the KPE group. We also examined mRNA expression of uncoupling protein 1 (UCP-1) and β3-adrenalin receptor (β3AR) in brown adipose tissue. As a result, mRNA expression of UCP-1 significantly increased in the KPE 1% treatment group, indicating that KPE activated brown adipose tissue. We then evaluated the direct effects of KPE on brown adipocytes using primary brown preadipocytes isolated from interscapular brown adipocytes in ICR mice. Triacylglycerol (TG) accumulation in primary brown preadipocytes was increased by KPE in a dose-dependent manner. Each mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ), UCP-1, and β3AR exhibited an upward trend compared with the control group. Moreover, some polymethoxyflavonoids (PMFs), the main compound in KP, also increased TG accumulation. This study therefore showed that KPE enhanced the thermogenesis effect of brown adipocytes as well as promoted the differentiation of brown adipocyte cells.

  8. Effects of Kaempferia parviflora Wall. Ex Baker on endothelial dysfunction in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Malakul, Wachirawadee; Thirawarapan, Suwan; Ingkaninan, Kornkanok; Sawasdee, Pattara

    2011-01-27

    The aim of the present study was to investigate an ethanolic extract of Kaempferia parviflora (KPE) reduces oxidative stress and preserves endothelial function in aortae from diabetic rats. Diabetes was induced in Sprague-Dawley rats by streptozotocin (STZ) treatment (55 mg/kg i.v.). Vascular reactivity and superoxide generation were assessed in aortic rings using standard organ bath techniques and lucigenin-enhanced chemiluminescence, respectively. Eight weeks after STZ treatment blood glucose was elevated compared to citrate treated control rats and there was an increased aortic generation of superoxide anion. In aortic rings acetylcholine-induced relaxation was impaired whereas endothelium-independent relaxation to sodium nitroprusside was unaffected. When aortic rings were acutely exposed to KPE (1, 10 and 100 μg/ml) there was a significant reduction in the detection of superoxide anion and enhanced relaxation to acetylcholine. Two separate groups of rats (control and diabetic) were orally administered daily with KPE (100 mg/kg body weight) for 4 weeks. KPE treatment reduced superoxide generation and increased the nitrite levels in diabetic aortae, and enhanced acetylcholine-induced relaxation. In the presence of N(G)-nitro-L-arginine (L-NNA), the relaxation to acetylcholine in aortic rings of diabetic rats was only partially inhibited, but was totally abolished in aortic rings from the KPE-treated diabetic rats. Indomethacin did not affect relaxation to acetylcholine in aortic rings of any group. These results suggest that KPE, acutely in vitro or after 4 weeks administration in vivo, reduces oxidant stress, increases NO bioavailability and preserves endothelium-dependent relaxation in aortae from diabetic rats. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  9. Simultaneous quantitative analysis of 12 methoxyflavones with melanogenesis inhibitory activity from the rhizomes of Kaempferia parviflora.

    Science.gov (United States)

    Ninomiya, Kiyofumi; Matsumoto, Taku; Chaipech, Saowanee; Miyake, Sohachiro; Katsuyama, Yushi; Tsuboyama, Akihiro; Pongpiriyadacha, Yutana; Hayakawa, Takao; Muraoka, Osamu; Morikawa, Toshio

    2016-04-01

    A methanol extract from the rhizomes of Kaempferia parviflora Wall. ex Baker (Zingiberaceae) has shown inhibitory effects against melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells (IC50 = 9.6 μg/mL). Among 25 flavonoids and three acetophenones isolated previously (1-28), several constituents including 5-hydroxy-7,3',4'-trimethoxyflavone (6, IC50 = 8.8 μM), 5,7,3',4'-tetramethoxyflavone (7, 8.6 μM), 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (12, 2.9 μM), and 5-hydroxy-3,7,3',4'-tetramethoxyflavone (13, 3.5 μM) showed inhibitory effects without notable cytotoxicity at the effective concentrations. Compounds 6, 7, 12, and 13 inhibited the expression of tyrosinase, tyrosine-related protein (TRP)-1, and TRP-2 mRNA, which could be the mechanism of their melanogenesis inhibitory activity. In addition, a quantitative analytical method for 12 methoxyflavones (1, 2, 4-11, 13, and 14) in the extract was developed using HPLC. The optimal condition for separation and detection of these constituents were achieved on an ODS column (3 μm particle size, 2.1 mm i.d. × 100 mm) with MeOH-0.1 % aqueous acetic acid solvent systems as the mobile phase, and the detection and quantitation limits of the method were estimated to be 0.08-0.66 ng and 0.22-2.00ng, respectively. The relative standard deviation values of intra- and interday precision were lower than 0.95 and 1.08 %, respectively, overall mean recoveries of all flavonoids were 97.9-102.9 %, and the correlation coefficients of all the calibration curves showed good linearity within the test ranges. For validation of the protocol, extracts of three kinds of the plant's rhizomes collected from different regions in Thailand (Leoi, Phetchabun, and Chiang Mai provinces) were evaluated. The results indicated that the assay was reproducible, precise, and could be readily utilized for the quality evaluation of the plant materials.

  10. The ethanolic extract of Kaempferia parviflora reduces ischaemic injury in rat isolated hearts.

    Science.gov (United States)

    Malakul, Wachirawadee; Ingkaninan, Kornkanok; Sawasdee, Pattara; Woodman, Owen L

    2011-09-01

    The ethanolic extract of Kaempferia parviflora (KPE) has been reported to contain a range of flavonoids and to enhance endothelial synthesis of NO. We investigated the vascular relaxant, antioxidant and cardioprotective activities of KPE. Vascular function was assessed in rat aortic rings and superoxide generation determined using lucigenin enhanced chemiluminescence. Ischaemia and reperfusion were induced in rat isolated, perfused hearts. KPE caused vasorelaxation (R(max) 102 ± 2%), which was partly inhibited by removal of the endothelium (R(max) 91 ± 1%) or by N(G)-nitro-l-arginine (L-NNA, R(max) 83 ± 3%) or 1H-[1,2,4] oxadiazolo[4,3-a]quinoxaline-1-one (ODQ, R(max) 80 ± 2%). In addition KPE caused concentration-dependent inhibition of the contractile response to exogenous Ca(2+). KPE (10(-3)M) also significantly inhibited superoxide radical generation induced by of xanthine/xanthine oxidase (2.3 ± 0.4% of control) to a similar extent to the xanthine oxidase inhibitor allopurinol (10(-4)M, 1.6 ± 0.5%) or by rat isolated aorta in the presence of NADPH (30.0 ± 6.3% of control) similarly to the NADPH oxidase inhibitor diphenyliodonium (5 × 10(-6)M, 23.1 ± 5.6%). In the presence of oxidant stress generated by pyrogallol endothelium-dependent relaxation of rat aortic rings was impaired (ACh R(max) control 99 ± 1%; pyrogallol 44 ± 5%), an effect that was significantly reduced by KPE (10(-4)M, ACh R(max) 82 ± 4%). In addition, KPE was found to attenuate the ventricular dysfunction caused by 20 min global ischaemia and 30 min reperfusion (I/R) in rat isolated hearts (dP/dt IR 1016 ± 242, IR+KPE 2238±233 mm Hg/s). KPE is an effective vasodilator and antioxidant that is able to prevent myocardial ischaemia-reperfusion injury. We suggest that KPE may be useful as an adjunct to thrombolytic therapy in the management of reperfusion injury. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors

    Science.gov (United States)

    Temkitthawon, Prapapan; Hinds, Thomas R.; Beavo, Joseph A.; Viyoch, Jarupa; Suwanborirux, Khanit; Pongamornkul, Wittaya; Sawasdee, Pattara; Ingkaninan, Kornkanok

    2014-01-01

    Aim of the study A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors. Materials and methods Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM. Results From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC50 = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition. Conclusions Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors. PMID:21884777

  12. Positive Modulation Effect of 8-Week Consumption of Kaempferia parviflora on Health-Related Physical Fitness and Oxidative Status in Healthy Elderly Volunteers

    OpenAIRE

    Jintanaporn Wattanathorn; Supaporn Muchimapura; Terdthai Tong-Un; Narisara Saenghong; Wipawee Thukhum-Mee; Bungorn Sripanidkulchai

    2012-01-01

    Health-related physical fitness declines as the age advances. Oxidative stress is reported to contribute the crucial role on this phenomenon. This condition is also enhanced by antioxidant. Therefore, we aimed to determine the effect of Kaempferia parviflora, a plant reputed for antifatigue, longevity promotion, and antioxidant effects, on health-related quality physical fitness and oxidative status of the healthy elderly volunteers. Total 45 subjects had been randomized to receive placebo or...

  13. Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors.

    Science.gov (United States)

    Temkitthawon, Prapapan; Hinds, Thomas R; Beavo, Joseph A; Viyoch, Jarupa; Suwanborirux, Khanit; Pongamornkul, Wittaya; Sawasdee, Pattara; Ingkaninan, Kornkanok

    2011-10-11

    A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors. Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM. From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC(50) = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition. Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Positive Modulation Effect of 8-Week Consumption of Kaempferia parviflora on Health-Related Physical Fitness and Oxidative Status in Healthy Elderly Volunteers

    Directory of Open Access Journals (Sweden)

    Jintanaporn Wattanathorn

    2012-01-01

    Full Text Available Health-related physical fitness declines as the age advances. Oxidative stress is reported to contribute the crucial role on this phenomenon. This condition is also enhanced by antioxidant. Therefore, we aimed to determine the effect of Kaempferia parviflora, a plant reputed for antifatigue, longevity promotion, and antioxidant effects, on health-related quality physical fitness and oxidative status of the healthy elderly volunteers. Total 45 subjects had been randomized to receive placebo or K. parviflora extract at doses of 25 or 90 mg once daily for 8 weeks. They were determined baseline data of physical performance using 30 sec chair stand test, hand grip test, 6 min walk test, and tandem test. Serum oxidative stress markers including malondialdehde (MDA level and the activities of superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px were also assayed. All assessments were performed every 4 weeks throughout the 8-week study period. The results showed that K. parviflora increased performance in 30-second chair stand test and 6 min walk test together with the increased all scavenger enzymes activities and the decreased MDA level. Therefore, K. parviflora can enhance physical fitness partly via the decreased oxidative stress. In conclusion, K. parviflora is the potential health supplement for elderly. However, further study is required.

  15. Positive Modulation Effect of 8-Week Consumption of Kaempferia parviflora on Health-Related Physical Fitness and Oxidative Status in Healthy Elderly Volunteers.

    Science.gov (United States)

    Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Tong-Un, Terdthai; Saenghong, Narisara; Thukhum-Mee, Wipawee; Sripanidkulchai, Bungorn

    2012-01-01

    Health-related physical fitness declines as the age advances. Oxidative stress is reported to contribute the crucial role on this phenomenon. This condition is also enhanced by antioxidant. Therefore, we aimed to determine the effect of Kaempferia parviflora, a plant reputed for antifatigue, longevity promotion, and antioxidant effects, on health-related quality physical fitness and oxidative status of the healthy elderly volunteers. Total 45 subjects had been randomized to receive placebo or K. parviflora extract at doses of 25 or 90 mg once daily for 8 weeks. They were determined baseline data of physical performance using 30 sec chair stand test, hand grip test, 6 min walk test, and tandem test. Serum oxidative stress markers including malondialdehde (MDA) level and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were also assayed. All assessments were performed every 4 weeks throughout the 8-week study period. The results showed that K. parviflora increased performance in 30-second chair stand test and 6 min walk test together with the increased all scavenger enzymes activities and the decreased MDA level. Therefore, K. parviflora can enhance physical fitness partly via the decreased oxidative stress. In conclusion, K. parviflora is the potential health supplement for elderly. However, further study is required.

  16. Pharmacological activity of Kaempferia parviflora extract against human bile duct cancer cell lines.

    Science.gov (United States)

    Leardkamolkarn, Vijittra; Tiamyuyen, Sunida; Sripanidkulchai, Bung-orn

    2009-01-01

    A crude ethanol extract of Kaemperia parviflora Wall. Ex Baker and a purified compound, 5,7,4-trimethoxyflavone (KP.8.10), were evaluated for pharmacological effects on human cholangiocarcinoma cell lines (HuCCA-1 and RMCCA-1). The cells were incubated with various concentrations of extract for various time periods and metabolic activity (MTT assay) was assessed for cell viability. The results showed a dose-dependent effect of both crude ethanol extract and the pure compound. CC50s for the crude extract on HuCCA-1 and RMCCA-1 cells were 46.1 microg/ml and 62.0 microg/ml, respectively. Values for the pure compound could not be determined because of solubility problems. Interestingly, K. parviflora ethanol extract and KP.8.10 at low concentrations (10-20 microg/ml and 2.5-5 microg/ml, respectively) markedly reduced rhHGF-induced invasion by HuCCA-1 and RMCCA-1 cells across matrix-coated transwell plates. Higher concentrations of K. parviflora ethanol extract (60 and 80 microg/ml) and KP.8.10 (20 microg /ml) dramatically changed the cellular morphology and caused death in both cell types. KP.8.10 further exhibited progressive action via caspase-3 mitochondrial enzyme activation, enhancing cellular toxicity in a time-dose dependent fashion. Therefore, 5,7,4-trimethoxyflavone appeared to be a bioactive component of K. parviflora extract capable of exerting anti-cancer action. The results suggested a benefit of this edible plant in prevention and treatment of cholangiocarcinoma.

  17. Induction of apoptosis in the human Leukemic U937 cell line by Kaempferia parviflora Wall.ex.Baker extract and effects of paclitaxel and camptothecin.

    Science.gov (United States)

    Banjerdpongchai, Ratana; Chanwikruy, Yupa; Rattanapanone, Viboon; Sripanidkulchai, Bungorn

    2009-01-01

    Kaempferia parviflora Wall.ex.Baker is a Thai medicinal herb that has high antioxidant and anti-inflammatory activities. Apoptotic effects of the herbal extract alone and in combination with chemotherapeutic drugs, paclitaxel and camptothecin, were here studied in the human promonocytic leukemic U937 cell line. K. parviflora extract suppressed cell proliferation and decreased cell viability in a dose- and time-dependent manner as assessed using the trypan blue exclusion assay. Staining of extract-treated cells with propidium iodide and examination under a fluorescence microscope showed condensed nuclei and apoptotic bodies. Mitochondrial transmembrane potential (MTP) decreased after treatment and the number of cells with decreased MTP also increased. Furthermore, activation of caspase-3 was found in herbal extract-treated cells. When the extract was combined with paclitaxel, an additive effect on U937 cell apoptosis was obtained, whereas camptothecin exerted an antagonistic effect.

  18. Suppressive effects of methoxyflavonoids isolated from Kaempferia parviflora on inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells.

    Science.gov (United States)

    Sae-Wong, Chutha; Matsuda, Hisashi; Tewtrakul, Supinya; Tansakul, Pimpimon; Nakamura, Seikou; Nomura, Yukiko; Yoshikawa, Masayuki

    2011-07-14

    The rhizomes of Kaempferia parviflora Wall. ex Baker have been traditionally used in Thailand to treat abscesses, gout, and peptic ulcers. Previously, we reported that the chloroform fraction of a Kaempferia parviflora extract had an inhibitory effect on rat paw-edema. In the present study, we isolated the constituents of this fraction and investigated the anti-inflammatory mechanism against nitric oxide (NO) production, tumor necrosis factor-α (TNF-α) and the expression of inducible nitric oxide synthase (iNOS) as well as phosphorylated extracellular signal-regulated kinase (p-ERK), and phosphorylated c-Jun N-terminal kinase (p-JNK). In addition, effects of trimethylapigenin (4) on the enzyme activities of protein kinases possibly leading to iNOS expression were examined to clarify the targets. The chloroform fraction was isolated using silica gel column chromatography and HPLC. Isolated compounds were tested against NO and TNF-α using RAW264.7 cells. Cytotoxicity and iNOS, p-ERK and p-JNK expression were also examined. Three active components, 5,7-dimethoxyflavone (2), trimethylapigenin (4), and tetramethylluteolin (5), markedly inhibited the production of NO in lipopolysaccharide (LPS)-activated RAW264.7 cells. Compounds 2, 4, and 5 moderately inhibited production of TNF-α. Compounds 2, 4, and 5 strongly inhibited expression of iNOS mRNA and iNOS protein in a dose-dependent manner, but did not inhibit p-ERK or p-JNK protein expression. The most active compound, 4, did not inhibit the enzyme activity of inhibitor of κB kinases or mitogen-activated protein kinases, but inhibited that of spleen tyrosine kinase (SYK). The mechanism responsible for the anti-inflammatory activity of methoxyflavonoids from the chloroform fraction of the rhizomes of Kaempferia parviflora is mainly the inhibition of iNOS expression, and the inhibition of SYK by 4 may be involved in the suppression of LPS-induced signaling in macrophages. Copyright © 2011 Elsevier Ireland Ltd. All

  19. Effects of compounds from Kaempferia parviflora on nitric oxide, prostaglandin E2 and tumor necrosis factor-alpha productions in RAW264.7 macrophage cells.

    Science.gov (United States)

    Tewtrakul, Supinya; Subhadhirasakul, Sanan

    2008-10-30

    Kaempferia parviflora Wall. ex Baker, is one of the plants in the Zingiberaceae family, locally known in Thai as kra-chai-dam. The rhizome of this plant has been used for treatment of gout, apthous ulcer and abscesses. Since K. parviflora rhizomes have long been used for treatment of inflammation and possessed marked nitric oxide (NO) inhibitory activity (IC(50)=7.8microg/ml), we thus investigated the inhibitory activity of compounds isolated from this plant against lipopolysaccharide (LPS)-induced NO release in RAW264.7 cells. From bioassay-guided fractionation of K. parviflora, seven methoxyflavones were isolated from the hexane fraction and were tested for their anti-inflammatory effects. Among the isolated compounds, compound 5 (5-hydroxy-3,7,3',4'-tetramethoxyflavone) exhibited the highest activity against NO release with an IC(50) value of 16.1microM, followed by 4 (IC(50)=24.5microM) and 3 (IC(50)=30.6microM). Compound 5 was also tested on LPS-induced prostaglandin E(2) (PGE(2)) and tumor necrosis factor-alpha (TNF-alpha) releases from RAW264.7 cells. It was revealed that 5 showed appreciable inhibitory effect on PGE(2) release (IC(50)=16.3microM), but inactive on TNF-alpha (IC(50)>100microM). These findings may support the use in Thai traditional medicine of K. parviflora for treatment of inflammatory-related diseases through the inhibition of NO and PGE(2) releases but partly due to that of TNF-alpha.

  20. Kaempferia parviflora rhizome extract and Myristica fragrans volatile oil increase the levels of monoamine neurotransmitters and impact the proteomic profiles in the rat hippocampus: Mechanistic insights into their neuroprotective effects

    Directory of Open Access Journals (Sweden)

    Waluga Plaingam

    2017-10-01

    Full Text Available Potentially useful in the treatment of neurodegenerative disorders, Kaempferia parviflora and Myristica fragrans have been shown to possess a wide spectrum of neuropharmacological activities and neuroprotective effects in vivo and in vitro. In this study, we determined whether and how K. parviflora ethanolic extract and M. fragrans volatile oil could influence the levels of neurotransmitters and the whole proteomic profile in the hippocampus of Sprague Dawley (SD rats. The effects of K. parviflora and M. fragrans on protein changes were analyzed by two-dimensional gel electrophoresis (2D-gel, and proteins were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS. The target proteins were then confirmed by Western blot. The levels of neurotransmitters were evaluated by reversed-phase high-performance liquid chromatography (RP-HPLC. The results showed that K. parviflora, M. fragrans and fluoxetine (the control drug for this study increased serotonin, norepinephrine and dopamine in the rat hippocampus compared to that of the vehicle-treated group. Our proteomic data showed that 37 proteins in the K. parviflora group were up-regulated, while 14 were down-regulated, and 27 proteins in the M. fragrans group were up-regulated, while 16 were down-regulated. In the fluoxetine treatment group, we found 29 proteins up-regulated, whereas 14 proteins were down-regulated. In line with the proteomic data, the levels of GFAP, PDIA3, DPYSL2 and p-DPYSL2 were modified in the SD rat groups treated with K. parviflora, M. fragrans and fluoxetine as confirmed by Western blot. K. parviflora and M. fragrans mediated not only the levels of monoamine neurotransmitters but also the proteomic profiles in the rat hippocampus, thus shedding light on the mechanisms targeting neurodegenerative diseases.

  1. Standardized Kaempferia parviflora Extract Inhibits Intrinsic Aging Process in Human Dermal Fibroblasts and Hairless Mice by Inhibiting Cellular Senescence and Mitochondrial Dysfunction

    Directory of Open Access Journals (Sweden)

    Ji-Eun Park

    2017-01-01

    Full Text Available Intrinsic skin aging is a complex biological phenomenon mainly caused by cellular senescence and mitochondrial dysfunction. This study evaluated the inhibitory effect of Kaempferia parviflora Wall ex. Baker ethanol extract (KPE on H2O2-stimulated cellular senescence and mitochondrial dysfunction both in vitro and in vivo. KPE significantly increased cell growth and suppressed senescence-associated β-galactosidase activation. KPE inhibited the expression of cell-cycle inhibitors (p53, p21, p16, and pRb and stimulated the expression of cell-cycle activators (E2F1 and E2F2. H2O2-induced hyperactivation of the phosphatidylinositol 3-kinase/protein kinase B (AKT signaling pathway was suppressed by KPE through regulated expression of forkhead box O3a (FoxO3a and mammalian target of rapamycin (mTOR. KPE attenuated inflammatory mediators (interleukin-6 (IL-6, IL-8, nuclear factor kappa B (NF-κB, and cyclooxygenase-2 (COX-2 and increased the mRNA expression of PGC-1α, ERRα, NRF1, and Tfam, which modulate mitochondrial biogenesis and function. Consequently, reduced ATP levels and increased ROS level were also reversed by KPE treatment. In hairless mice, KPE inhibited wrinkle formation, skin atrophy, and loss of elasticity by increasing the collagen and elastic fibers. The results indicate that KPE prevents intrinsic aging process in hairless mice by inhibiting cellular senescence and mitochondrial dysfunction, suggesting its potential as a natural antiaging agent.

  2. Effects of Kaempferia parviflora Wall. Ex. Baker and sildenafil citrate on cGMP level, cardiac function, and intracellular Ca2+ regulation in rat hearts.

    Science.gov (United States)

    Weerateerangkul, Punate; Palee, Siripong; Chinda, Kroekkiat; Chattipakorn, Siriporn C; Chattipakorn, Nipon

    2012-09-01

    Although Kaempferia parviflora extract (KPE) and its flavonoids have positive effects on the nitric oxide (NO) signaling pathway, its mechanisms on the heart are still unclear. Because our previous studies demonstrated that KPE decreased defibrillation efficacy in swine similar to that of sildenafil citrate, the phosphodiesterase-5 inhibitor, it is possible that KPE may affect the cardiac NO signaling pathway. In the present study, the effects of KPE and sildenafil citrate on cyclic guanosine monophosphate (cGMP) level, modulation of cardiac function, and Ca transients in ventricular myocytes were investigated. In a rat model, cardiac cGMP level, cardiac function, and Ca transients were measured before and after treatment with KPE and sildenafil citrate. KPE significantly increased the cGMP level and decreased cardiac function and Ca transient. These effects were similar to those found in the sildenafil citrate-treated group. Furthermore, the nonspecific NOS inhibitor could abolish the effects of KPE and sildenafil citrate on Ca transient. KPE has positive effect on NO signaling in the heart, resulting in an increased cGMP level, similar to that of sildenafil citrate. This effect was found to influence the physiology of normal heart via the attenuation of cardiac function and the reduction of Ca transient in ventricular myocytes.

  3. Standardized Kaempferia parviflora Extract Inhibits Intrinsic Aging Process in Human Dermal Fibroblasts and Hairless Mice by Inhibiting Cellular Senescence and Mitochondrial Dysfunction.

    Science.gov (United States)

    Park, Ji-Eun; Woo, Seon Wook; Kim, Mi-Bo; Kim, Changhee; Hwang, Jae-Kwan

    2017-01-01

    Intrinsic skin aging is a complex biological phenomenon mainly caused by cellular senescence and mitochondrial dysfunction. This study evaluated the inhibitory effect of Kaempferia parviflora Wall ex. Baker ethanol extract (KPE) on H2O2-stimulated cellular senescence and mitochondrial dysfunction both in vitro and in vivo. KPE significantly increased cell growth and suppressed senescence-associated β-galactosidase activation. KPE inhibited the expression of cell-cycle inhibitors (p53, p21, p16, and pRb) and stimulated the expression of cell-cycle activators (E2F1 and E2F2). H2O2-induced hyperactivation of the phosphatidylinositol 3-kinase/protein kinase B (AKT) signaling pathway was suppressed by KPE through regulated expression of forkhead box O3a (FoxO3a) and mammalian target of rapamycin (mTOR). KPE attenuated inflammatory mediators (interleukin-6 (IL-6), IL-8, nuclear factor kappa B (NF-κB), and cyclooxygenase-2 (COX-2)) and increased the mRNA expression of PGC-1α, ERRα, NRF1, and Tfam, which modulate mitochondrial biogenesis and function. Consequently, reduced ATP levels and increased ROS level were also reversed by KPE treatment. In hairless mice, KPE inhibited wrinkle formation, skin atrophy, and loss of elasticity by increasing the collagen and elastic fibers. The results indicate that KPE prevents intrinsic aging process in hairless mice by inhibiting cellular senescence and mitochondrial dysfunction, suggesting its potential as a natural antiaging agent.

  4. Polymethoxyflavonoids from Kaempferia parviflora induce adipogenesis on 3T3-L1 preadipocytes by regulating transcription factors at an early stage of differentiation.

    Science.gov (United States)

    Horikawa, Takumi; Shimada, Tsutomu; Okabe, Yui; Kinoshita, Kaoru; Koyama, Kiyotaka; Miyamoto, Ken-ichi; Ichinose, Koji; Takahashi, Kunio; Aburada, Masaki

    2012-01-01

    We previously reported that Kaempferia parviflora WALL. ex BAKER (KP) and its ethyl acetate extract (KPE) improve various metabolic disorders in obesity-model mice. However the mechanism is not certain, and, in this study, in order to elucidate the mechanism of the suppressive effect of KP on fat accumulation, we focused on adipocytes, which are closely linked to metabolic diseases. The finding was that KPE and its components, 3,5,7,4'-tetramethoxyflavone and 3,5,7,3',4'-pentamethoxyflavone, strongly induced differentiation of 3T3-L1 preadipocytes to adipocytes. The above two polymethoxyflavonoids (PMFs) also induced adiponectin mRNA levels, and release of adiponectin into the medium. In addition, these PMFs enhanced the expression of peroxisome proliferator-activated receptor γ (PPARγ), but did not show PPARγ ligand activity. We then investigated the expression of the differentiation-regulator located upstream of PPARγ. Expression of CCAAT/enhancer-binding protein (C/EBP) β and -δ mRNA, a transcriptional regulator of PPARγ, was induced, and expression of GATA-2 mRNA, a down-regulator of adipogenesis, was suppressed by these PMFs. These functions of the KP PMFs that enhance adipogenesis and secretion of adiponectin are, to some extent at least, involved in the mechanisms of anti-metabolic disorders effects.

  5. Inhibitory effects of Kaempferia parviflora extract on monocyte adhesion and cellular reactive oxygen species production in human umbilical vein endothelial cells.

    Science.gov (United States)

    Horigome, Satoru; Yoshida, Izumi; Ito, Shihomi; Inohana, Shuichi; Fushimi, Kei; Nagai, Takeshi; Yamaguchi, Akihiro; Fujita, Kazuhiro; Satoyama, Toshiya; Katsuda, Shin-Ichi; Suzuki, Shinobu; Watai, Masatoshi; Hirose, Naoto; Mitsue, Takahiro; Shirakawa, Hitoshi; Komai, Michio

    2017-04-01

    The rhizome of Kaempferia parviflora (KP) is used in traditional Thai medicine. In this study, we investigated the effects of an ethanol KP extract and two of its components [5,7-dimethoxyflavone (DMF) and 5-hydroxy-3,7,3',4'-tetramethoxyflavone (TMF)] on monocyte adhesion and cellular reactive oxygen species (ROS) production in human umbilical vein endothelial cells (HUVECs), which provide an in vitro model of events relevant to the development and progression of atherosclerosis. RAW264.7 mouse macrophage-like cells were incubated with various concentrations of KP extract or polymethoxyflavonoids and stimulated with lipopolysaccharide prior to measuring nitrite levels in the culture media. Monocyte adhesion was evaluated by measuring the fluorescently labeled human monocytic leukemia THP-1 cells that is attached to tumor necrosis factor-α (TNF-α)-stimulated HUVECs. Cellular ROS production was assessed by measuring cellular antioxidant activity using pyocyanin-stimulated HUVECs. KP extract and DMF reduced nitrite levels (as indicator of nitric oxide production) in LPS-stimulated RAW264.7 cells and also inhibited THP-1 cell adhesion to HUVECs. These treatments induced mRNA expression of endothelial nitric oxide synthase in TNF-α-stimulated HUVECs and downregulated that of various cell adhesion molecules, inflammatory mediators, and endothelial function-related genes. Angiotensin-converting enzyme activity was inhibited by KP extract in vitro. Furthermore, KP extract, DMF, and TMF inhibited the production of cellular ROS in pyocyanin-stimulated HUVECs. KP extract, DMF, and TMF showed potential anti-inflammatory and antioxidant effects in these in vitro models, properties that would inhibit the development and progression of atherosclerosis.

  6. Novel formulation strategies for enhancing oral delivery of methoxyflavones in Kaempferia parviflora by SMEDDS or complexation with 2-hydroxypropyl-β-cyclodextrin.

    Science.gov (United States)

    Mekjaruskul, Catheleeya; Yang, Yu-Tsai; Leed, Marina G D; Sadgrove, Matthew P; Jay, Michael; Sripanidkulchai, Bungorn

    2013-03-10

    The Kaempferia parviflora (KP) plant contains several methoxyflavones including 5,7-dimethoxyflavone (DMF), 5,7,4'-trimethoxyflavone (TMF), and 3,5,7,3',4'-pentamethoxyflavone (PMF). Ethanolic extracts of KP have shown various pharmacological effects and have been used as an aphrodisiac, a antimicrobial agent and for the treatment of inflammation, and peptic ulcers. Given its poor water solubility and low oral bioavailability (1-4%), there are limitations to the utilization of KP. Accordingly, self-microemulsifying drug delivery system (SMEDDS) and cyclodextrin (CD) complex formulations were developed to improve the oral absorption of methoxyflavones. Polyoxyethylene castor oil (53.3%), propylene glycol (26.7%), and triglyceride of coconut oil (20%) were combined to form KP-SMEDDS. A complex of 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) and KP was prepared by lyophilization. The developed formulations were then evaluated for their physicochemical properties, in vitro dissolution tests, permeability through Caco-2 cells, and in vivo oral absorption in rats by using PMF, TMF, and DMF as the markers for quantitation. The results showed that KP-SMEDDS and KP-2-HP-β-CD complex improved the dissolution rate of methoxyflavones in both 0.1N HCl and 0.2M PBS pH 6.8 compared to KP dissolved in a solution of propylene glycol, PEG 400, ethanol, and water. KP-SMEDDS and KP-2-HP-β-CD formulations showed about 10- and 3.5-fold greater Papp values of methoxyflavones in Caco-2 cells. The oral bioavailability values of KP-SMEDDS formulations were higher than those of KP (25.38-, 42.00-, and 26.01-fold for PMF, TMF, and DMF, respectively). For the KP-2-HP-β-CD complex, oral bioavailability values were 21.63-, 34.20-, and 22.90-fold greater than those of KP, respectively. Therefore, these two novel formulations, KP-SMEDDS and KP-2-HP-β-CD, were successfully developed to improve the dissolution rate, drug permeability through Caco-2 cells and oral bioavailability of

  7. Genetic variation of Kaempferia (Zingiberaceae) in Thailand based on chloroplast DNA (psbA-trnH and petA-psbJ) sequences.

    Science.gov (United States)

    Techaprasan, J; Klinbunga, S; Ngamriabsakul, C; Jenjittikul, T

    2010-10-05

    Genetic variation and species authentication of 71 Kaempferia accessions (representing 15 recognized, six new, and four unidentified species) found indigenously in Thailand were examined by determining chloroplast psbA-trnH and partial petA-psbJ spacer sequences. Ten closely related species (Boesenbergia rotunda, Gagnepainia godefroyi, G. thoreliana, Globba substrigosa, Smithatris myanmarensis, S. supraneanae, Scaphochlamys biloba, S. minutiflora, S. rubescens, and Stahlianthus sp) were also included. After sequence alignments, 1010 and 865 bp in length were obtained for the respective chloroplast DNA sequences. Intraspecific sequence variation was not observed in Kaempferia candida, K. angustifolia, K. laotica, K. galanga, K. pardi sp nov., K. bambusetorum sp nov., K. albomaculata sp nov., K. minuta sp nov., Kaempferia sp nov. 1, and G. thoreliana, for which more than one specimen was available. In contrast, intraspecific sequence polymorphisms were observed in various populations of K. fallax, K. filifolia, K. elegans, K. pulchra, K. rotunda, K. marginata, K. parviflora, K. larsenii, K. roscoeana, K. siamensis, and G. godefroyi. A strict consensus tree based on combined psbA-trnH and partial petA-psbJ sequences revealed four major groups of Kaempferia species. We suggest that the genus Kaempferia is a polyphyletic group, as K. candida was distantly related and did not group with other Kaempferia species. Polymorphic sites and indels of psbA-trnH and petA-psbJ can be used as DNA barcodes for species diagnosis of most Kaempferia and outgroup species. Nuclear DNA polymorphism should be examined to determine if there has been interspecific hybridization and chloroplast DNA introgression in these taxa.

  8. Metabolism of Kaempferia parviflora polymethoxyflavones by human intestinal bacterium Bautia sp. MRG-PMF1.

    Science.gov (United States)

    Kim, Mihyang; Kim, Nayoung; Han, Jaehong

    2014-12-24

    Poylmethoxyflavones (PMFs) are major bioactive flavonoids, which exhibit various biological activities, such as anticancer effects. The biotransformation of PMFs and characterization of a PMF-metabolizing human intestinal bacterium were studied herein for the first time. Hydrolysis of aryl methyl ether functional groups by human fecal samples was observed from the bioconversion of various PMFs. Activity-guided screening for PMF-metabolizing intestinal bacteria under anaerobic conditions resulted in the isolation of a strict anaerobic bacterium, which was identified as Blautia sp. MRG-PMF1. The isolated MRG-PMF1 was able to metabolize various PMFs to the corresponding demethylated flavones. The microbial conversion of bioactive 5,7-dimethoxyflavone (5,7-DMF) and 5,7,4'-trimethoxyflavone (5,7,4'-TMF) was studied in detail. 5,7-DMF and 5,7,4'-TMF were completely metabolized to 5,7-dihydroxyflavone (chrysin) and 5,7,4'-trihydroxyflavone (apigenin), respectively. From a kinetics study, the methoxy group on the flavone C-7 position was found to be preferentially hydrolyzed. 5-Methoxychrysin, the intermediate of 5,7-DMF metabolism by Blautia sp. MRG-PMF1, was isolated and characterized by nuclear magnetic resonance spectroscopy. Apigenin was produced from the sequential demethylation of 5,7,4'-TMF, via 5,4'-dimethoxy-7-hydroxyflavone and 7,4'-dihydroxy-5-methoxyflavone (thevetiaflavone). Not only demethylation activity but also deglycosylation activity was exhibited by Blautia sp. MRG-PMF1, and various flavonoids, including isoflavones, flavones, and flavanones, were found to be metabolized to the corresponding aglycones. The unprecedented PMF demethylation activity of Blautia sp. MRG-PMF1 will expand our understanding of flavonoid metabolism in the human intestine and lead to novel bioactive compounds.

  9. Effects of Kaempferia parviflora Wall. Ex. Baker on electrophysiology of the swine hearts

    Directory of Open Access Journals (Sweden)

    Punate Weerateerangkul

    2013-01-01

    Interpretation & conclusions: High concentrations of KP extract attenuated defibrillation efficacy and increased cardiac vulnerability to arrhythmia in a normal swine heart. When used in appropriate concentrations, its blood pressure lowering effect may be useful in hypertensive states. Further studies need to be done to elucidate its mechanism of action.

  10. Spectroscopic and Antibacterial Studies of Anisotropic Gold Nanoparticles Synthesized Using Malva parviflora

    Science.gov (United States)

    Zayed, M. F.; Eisa, W. H.; Hezma, A. M.

    2017-01-01

    Anisotropic gold nanoparticles (Au NPs) have been synthesized via a green route with the aid of Malva parviflora ( M. parviflora) extract. Their UV-vis-NIR spectra exhibit a near infrared absorption feature, which is due to the one-dimensional growth of Au NPs. The images of transmission electron microscopy (TEM) show that the Au NPs are triangular in shape. The formation of Au anisotropic nanoparticles was found to depend on the extract quantity. The Au NPs show good antibacterial activity against the Gram-positive bacteria Bacillus subtilis and Enterococcus faecalis.

  11. Cytochemical characterization of plastidal inclusions in Abutilon mosaic-infected Malva parviflora mesophyll cells.

    Science.gov (United States)

    Jeske, H; Werz, G

    1980-10-15

    Electron microscopy of plastids from mesophyll cells of Malva parviflora infected with the Abutilon mosaic virus revealed elongated "chains of pearls" with subunits of 7.5 nm in diameter. Paracrystalline inclusions of the chains of pearls studied by means of cytochemical techniques gave evidence of the presence of DNA.

  12. Composition of the essential oils of Kaempferia rotunda L. and Kaempferia angustifolia Roscoe rhizomes from Indonesia

    NARCIS (Netherlands)

    Woerdenbag, HJ; Windono, T; Bos, R; Riswan, S; Quax, WJ

    2004-01-01

    The volatile constituents of rhizomes (main rhizome, lateral parts) of two medicinally used Indonesian plants of the family Zingiberaceae, Kaempferia rotunda L. and K. angustifolia Roscoe, were investigated by GC and GC-MS (EI) analysis. A total of 75 compounds were identified. The most abundant con

  13. Domesticated proboscidea parviflora: a potential oilseed crop for arid lands

    Energy Technology Data Exchange (ETDEWEB)

    Berry, J.; Bretting, P.K.; Nabhan, G.P.; Weber, C.

    1981-01-01

    Wild and domesticated Proboscidea parviflora were evaluated as oilseed crops for arid lands through chemical and biological analyses. Domesticated plants grown in the Sonoran desert bore seed containing 35-40 per cent oil and 23-27 per cent protein. Yield per hectare was estimated at 1000 kg of oil and 675 kg of protein, quantities which compare favourably with other crops. An ephemeral life cycle and certain characteristics of the fruit and seed allow this plant to grow in xeric habitats unsuitable for many other plants. Several Proboscidea species hybridize with P. parviflora and could be used in future crop breeding. Rapid germination and higher oil and protein content of seed make the domesticated P. parviflora superior to the wild form as a crop. Domesticated P. parviflora thus shows promise as an oilseed crop for the Sonoran Desert and possibly for other arid regions. (Refs. 22).

  14. Malva parviflora extract assisted green synthesis of silver nanoparticles

    Science.gov (United States)

    Zayed, Mervat F.; Eisa, Wael H.; Shabaka, A. A.

    2012-12-01

    Five plant leaf extracts (Malva parviflora, Beta vulgaris subsp. Vulgaris, Anethum graveolens, Allium kurrat and Capsicum frutescens) were screened for their bioreduction behavior for synthesis of silver nanoparticles. M. parviflora (Malvaceae) was found to exhibit the best reducing and protecting action in terms of synthesis rate and monodispersity of the prepared silver nanoparticles. Our measurements indicate that biosynthesis of Ag nanoparticles by M. parviflora produces Ag nanoparticles with the diameters in the range of 19-25 nm. XRD studies reveal a high degree of crystallinity and monophasic Ag nanoparticles of face-centered cubic structure. FTIR analysis proved that particles are reduced and stabilized in solution by the capping agent that is likely to be proteins secreted by the biomass. The present process is an excellent candidate for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive.

  15. Anti-allergic activity of some selected plants in the genus Boesenbergia and Kaempferia

    Directory of Open Access Journals (Sweden)

    Fameera Madaka

    2011-06-01

    Full Text Available Ethanolic and water extracts from the rhizomes of eight selected Zingiberaceous plants, including Boesenbergiathorelii, Boesenbergia sp 1, Boesenbergia sp 2, Boesenbergia sp 3, Kaempferia angustifolia, Kaempferia marginata,Kaempferia rotunda and Kaempferia sp were tested for their anti-allergic activities using the rat basophilic leukemia strain2H3 (RBL-2H3 cell line. Both the ethanolic (EtOH and water extracts of Boesenbergia thorelii exhibited the most potentanti-allergic effects against antigen-induced â-hexosaminidase release as a marker of degranulation in RBL-2H3 cells, withIC50 values of 23.0 and 26.3 g/ml, respectively. Other extracts also had some activity from Boesenbergia sp 2 (EtOH, IC50 =38.3 g/ml, Kaempferia marginata (water, IC50 = 38.4 g/ml, Boesenbergia sp 3 (EtOH, IC50 = 49.4 g/ml and Kaempferiaangustifolia (water, IC50 = 55.6 g/ml, whereas other Boesenbergia and Kaempferia spp had little or no activity. These findingssupport the use of Boesenbergia thorelii for the treatment of allergies and allergy-related diseases.

  16. Biomass structure of exotic invasive plant Galinsona parviflora

    Institute of Scientific and Technical Information of China (English)

    Shuyan QI; Wenduo XU; Yan WEN

    2008-01-01

    Galinsona parviflora (Asteraceae) is a wide-spread annual weed that is invasive,colonizing new ground where it is able to persist.We studied the bio-mass structure of the G.Parviflora population at the module level by using the methods of field plot invest-igation and weighing at 10 sample plots.Modular bio-mass was calculated and used for analysis of relation-ships between various modules.The results show that there was a positive correlation between plant height and modular biomass,between stem biomass and root biomass,stem biomass and capitulum biomass,above-ground biomass and underground biomass,and lastly,stem biomass and leaf biomass.The preferred model which measured all the relationships was a power func-tion model with absolute coefficients(R2) ranging from 0.6303 to 0.9782.

  17. The Chemical Constituents of Diterpenoids from Kaempferia marginata Carey

    Institute of Scientific and Technical Information of China (English)

    YuJingguang; YuDonglei; SunLan; ZhangShu; ZhengCaicheng; ChenYuheng

    2001-01-01

    Marginatol (1), a new isopimarene diterpenoid, and five known compounds 8(14),15-sandera-copimaradiene-1α,9α-diol (2), 8(14), 15-sanderacopimaradene-1α 6β,9α-triol (3), germacrone (4), trans-ethyl p-methoxycinnamate (5) and n-pentadecane (6) were isolated from the hexane extract of Kaempferia marginata Carey.The structure of marginatol (1) was established as 8(14),15-isopimaradiene-6α-ol on the basis of spectral data (IR,MS,1h--1H 13C-1H NOESY and HMBC). Compounds 2, 3 and 4 were isolated for the first time from thisplant.

  18. The spread of Impatiens parviflora DC. in Central European oak forests – another stage of invasion?

    Directory of Open Access Journals (Sweden)

    Kamila Reczyńska

    2015-12-01

    Full Text Available In this study, we examine the pattern of occurrence of Impatiens parviflora in Central European oak forests over time and its ecological requirements within these types of communities. Research was based on phytosociological data collected in 3776 relevés. A modified TWINSPAN algorithm were used to distinguish the groups of oak forests. The ecological preferences of the I. parviflora and studied communities as well as differences between invaded and non-invaded vegetation plots were analyzed using mean weighted Ellenberg indicator values (EIVs. Finally, both the temporal pattern of I. parviflora participation and changes in its coverage in the studied communities were analyzed. Our study confirmed a high adaptability of this species with respect to temperature, moisture, soil reaction and nutrients and determined its broad ecological optimum in oak forests. However, it also revealed both a greater sensitivity of some communities within Central European oak forests to the invasion of I. parviflora and differences in habitat conditions between invaded and non-invaded vegetation plots. This suggests that the habitat niche of I. parviflora within oak forests is not accidental. The analysis of temporal changes in the frequency of I. parviflora confirmed a 20% increase in relevés over the last 50 years. However, we did not identify any statistically significant rise in the coverage of I. parviflora in oak forests specifically during the studied period.

  19. OPTIMASI YIELD ETIL P METOKSISINAMAT PADA EKSTRAKSI OLEORESIN KENCUR (Kaempferia galanga) MENGGUNAKAN PELARUT ETANOL

    OpenAIRE

    Eko Setyawan; Pandhu Putratama; Asriningtyas Ajeng; Wara Dyah Pita Rengga

    2013-01-01

    Kencur (Kaempferia galanga L.) banyak digunakan sebagai bahan baku obat tradisional (jamu), fitofarmaka, industri kosmetika, industri makanan, dan industri insektisida. Minyak atsiri rimpang kencur mengandung etil sinnamat dan metil p-metoksi sinamat (EPMS). Ekstraksi oleoresin kencur dilakukan dengan etanol sebagai pelarut. Optimasi yield EPMS diteliti terhadap perbandingan massa serbuk kering kencur dan etanol dan waktu ekstraksi. Perbandingan kencur : etanol yang digunakan adalah 1 : 2, 1 ...

  20. Hepatoprotective activity of methanolic extract of Malva parviflora against paracetamol-induced hepatotoxicity in mice

    Directory of Open Access Journals (Sweden)

    Tauqeer Hussain Mallhi

    2014-08-01

    Full Text Available Malva parviflora (cheeseweed is traditionally used as hepatoprotective. The current study was conducted to determine its hepatoprotective activity of aqueous methanolic extract of whole plant. Two doses of plant (250 mg/kg and 500 mg/kg were administered in paracetamol intoxicated mice and results were compared with silymarin. Observational parameters were ALT, AST, ALP and total bilirubin. The results showed that the extract of M. parviflora produced significant (p<0.001 reduction in liver enzymes and total bilirubin. Results were supported by histopathological investigation, phytochemical screening and detection of hepatoprotective constituents (kaempferol and apigenin by HPLC. So, the current study showed that aqueous methanolic extract of M. parviflora possesses hepatoprotective activity.

  1. Potent heterologous antifungal proteins from cheeseweed (Malva parviflora).

    Science.gov (United States)

    Wang, X; Bunkers, G J

    2000-12-20

    Two novel antifungal proteins were purified and characterized from cheeseweed (Malva parviflora). Both proteins, designated CW-1 and CW-2, are composed of two different subunits of 5000 and 3000 Da, respectively. These proteins possess very potent antifungal activities, and more interestingly the inhibition is fungicidal instead of fungistatic. At low salt condition, the IC(50) of CW-1 and CW-2 against Fusarium graminearum (Fg) is 2.5 ppm. At high salt condition which diminishes the antifungal activity of many antifungal proteins, both CW-1 and CW-2 still maintain potent activity against Fg with IC(50) of 10 ppm. The two subunits could be separated by gel filtration in the presence of 6 M urea, but their antifungal activity cannot be recovered after the removal of urea. Amino acid sequence analysis indicates that both subunits of CW-1 show homology to 2S albumin, whereas the two subunits of CW-2 have homology to vicilin protein from cotton. To our knowledge, this is the first report of isolation and characterization of heterologous antifungal proteins from any source.

  2. New phytoconstituents from the aerial parts of Fumaria parviflora Lam

    Directory of Open Access Journals (Sweden)

    Mohammad Jameel

    2014-01-01

    Full Text Available Fumaria parviflora Lam. (Fumariaceae is an annual herb found throughout the world. Traditionally it has great significance in various disorders. In folk medicine of Turkey it is used against hepato-biliary dysfunction and imported from Iran. In Charaka and Sushruta, it is recommended for treatment of fevers, blood disorders, chronic skin diseases, urinary diseases and cough. The compounds were isolated from methanolic extract of the plants by column chromatography using silica gel (60-120 mesh as stationary phase and structure of the isolated compounds have been established on the basis of spectral data analysis and chemical reactions. Phytochemical investigation of its aerial parts led to the isolation of five new compounds characterized as (5αH,11αH-8-oxo-homoiridolide (1, n-docosanyl-2-O-β-D-glucopyranosyl salicylate (2, 2-methyl-6-hydroxymethylenedodecan-10-oyl-12, 15-olide14-O-β-D-xylopyranoside (3, 4-oxo-stigmast-5-en-3β-ol-D-glucopyranoside (4 and salicylic acid-O-β-D-xylopyranoside (5 along with the known compounds α-D-glucopyranosyl hexadecanoate (6 and α-D-glucopyranosyl- (2 → 1ʹ-α-D-glucopyranoside (7. The isolated compounds are useful as they will provide essential data and information for the further researchers and development of effective analytical marker for identity, purity and quality control of this traditional plant in future.

  3. Effects of mulching tolerant plant straw on soil surface on growth and cadmium accumulation of Galinsoga parviflora.

    Directory of Open Access Journals (Sweden)

    Lijin Lin

    Full Text Available Pot and field experiments were conducted to study the effects of mulching with straw of cadmium (Cd tolerant plants (Ranunculus sieboldii, Mazus japonicus, Clinopodium confine and Plantago asiatica on growth and Cd accumulation of Galinsoga parviflora in Cd-contaminated soil. In the pot experiment, mulching with M. japonicus straw increased the root biomass, stem biomass, leaf biomass, shoot biomass, plant height and activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase of G. parviflora compared with the control, whereas mulching with straws of R. sieboldii, C. confine and P. asiatica decreased these parameters. Straws of the four Cd-tolerant plants increased the Cd content in roots of G. parviflora compared with the control. However, only straws of M. japonicus and P. asiatica increased the Cd content in shoots of G. parviflora, reduced the soil pH, and increased the soil exchangeable Cd concentration. Straw of M. japonicus increased the amount of Cd extraction in stems, leaves and shoots of G. parviflora by 21.11%, 29.43% and 24.22%, respectively, compared with the control, whereas straws of the other three Cd-tolerant plants decreased these parameters. In the field experiment, the M. japonicus straw also increased shoot biomass, Cd content in shoots, and amount of Cd extraction in shoots of G. parviflora compared with the control. Therefore, straw of M. japonicus can be used to improve the Cd extraction ability of G. parviflora from Cd-contaminated soil.

  4. Pollination biology of Habenaria parviflora (Orchidaceae: Habenariinae in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Singer

    2001-01-01

    Full Text Available Se estudió la biologia floral de Habenaria parviflora (Orchidaceae: Habenariinae en Picinguaba, Estado de São Paulo, sudeste del Brasil, con la finalidad de incrementar el conocimiento sobre la biología de la polinización y morfología funcional de este género de Orquídeas terrestres. Estas plantas son autocompatibles, pero polinizador-dependientes. Los polinizadores registrados fueron hembras de Tipúlidos (Diptera: Tipulidae y polillas Pyralidae (Lepidoptera: Pyralidae. El mecanismo de polinización es el mismo, independientemente del tipo de polinizador: los polinarios se fijan a la probóscide de los polinizadores a través de su viscidio en forma de guante, y son removidos cuando los insectos dejan las flores. Cuando visita otra flor, un insecto que lleva polinários los rozará contra las superfícies estigmáticas, dejando acúmulos de másulas, efectuando así la polinización. Hasta donde se sabe, este tipo de fijación de polinarios es informado por primera vez para el género Habenaria y es una clara consecuencia de la morfología del viscidio. El viscidio involuto, en forma de guante, es una característica única entre las especies neotropicales del género Habenaria. Los caracteres florales que favorecen la polinización cruzada son discutidos brevemente. Éste es también hasta donde sabemos, el primer registro de polinización de orquídeas por Tipúlidos (Tipulidae en los neotrópicos

  5. In vitro antimicrobial activity on clinical microbial strains and antioxidant properties of Artemisia parviflora

    Directory of Open Access Journals (Sweden)

    Ahameethunisa Abdul R

    2012-11-01

    Full Text Available Abstract Background Artemisia parviflora leaf extracts were evaluated for potential antimicrobial and antioxidant properties. Antimicrobial susceptibility assay was performed against ten standard reference bacterial strains. Antioxidant activity was analyzed using the ferric thiocyanate and 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH assays. Radical scavenging activity and total phenolic content were compared. Phytochemical analyses were performed to identify the major bioactive constitution of the plant extract. Results Hexane, methanol and ethyl acetate extracts of A. parviflora leaves exhibited good activity against the microorganisms tested. The n-hexane extract of A. parviflora showed high inhibition of the growth of Pseudomonas aeruginosa, Escherichia coli and Shigella flexneri. Methanol extract showed strong radical scavenging and antioxidant activity, other extracts showed moderate antioxidant activity. The major derivatives present in the extracts are of terpenes, steroids, phenols, flavonoids, tannins and volatile oil. Conclusions The results obtained with n-hexane extract were particularly significant as it strongly inhibited the growth of P. aeruginosa, E. coli and S. flexneri. The major constituent of the n-hexane extract was identified as terpenes. Strong antioxidant activity could be observed with all the individual extracts. The antimicrobial and antioxidant property of the extracts were attributed to the secondary metabolites, terpenes and phenolic compounds present in A. parviflora and could be of considerable interest in the development of new drugs.

  6. PENGARUH FREKUENSI IRIGASI DAN WAKTU PEMBERIAN AIR TERHADAP PERTUMBUHAN DAN PRODUKSI KENCUR (Kaempferia galangal L.

    Directory of Open Access Journals (Sweden)

    Eko Sulistyono

    2011-09-01

    Full Text Available The research was conducted to result F factor value (fraction of available water that could be absorbed by Kaempferia galangal L.. This value was needed for determining irrigation frequency.  Factorial experiment was arranged in Randomized Block Design with three replications.  The first factor was irrigation frequency included irrigation until field capacity every 2, 4, 6, 8 days respectively, irrigation every 2 days until 75%, 50%, and 25% of available water respectively.  The second factor was irrigation time included from planting, 2 weeks before harvesting, and 4 weeks before harvesting until harvesting respectively. Interaction between irrigation frequency and irrigation time effected plant height, leaf area index, evapotranspiration, but did not affect yield.  Treatment that resulted the highest plant, the biggest leaf area index and the least evapotranspiration was irrigation until field capacity every 6 days from 4 weeks before harvesting until harvesting. The research resulted F factor value (fraction of available water that could be absorbed by Kaempferia galangal L. as much as 48%.

  7. Occurrence and dynamics of Impatiens parviflora depending on various environmental conditions in the protected areas in Slovakia

    Directory of Open Access Journals (Sweden)

    Bobuľská Lenka

    2016-06-01

    Full Text Available Biological invasion as one of the main threats to natural ecosystems has big economic impact on conservation of nature. Studies of the population biology of invasive species may allow more precise focus on specific plant and soil characteristics involved in invasiveness. The aim of the study was to investigate the relationship between selected biological population characteristics of Impatiens parviflora and a few chosen chemical and physical soil features. Sites were selected because of the poor mapping of invasive plants in the protected natural areas and their interactions with specific soil characteristics. Research on I. parviflora was realised during a vegetation season in three forest nature reserves in Prešov district, Slovakia. Some population biological characteristics of I. parviflora as one of the most invasive plant species in Slovakia and Central Europe were surveyed. The correlation between the numbers of plants was analysed, as well as select population biological characteristics of I. parviflora (plant height, width of the largest leaf and the number of flowers/fruits on some select chemical and physical soil attributes (soil pH, bulk density, porosity and soil moisture were analysed. The results suggest that biological characteristics of I. parviflora in three different microhabitats – a meadow (a habitat without tree vegetation, a habitat close to the stumps and a habitat under dense tree vegetation seemed to influence the selected soil parameters. Our results showed that I. parviflora prefers acidic and non-compacted soil conditions. Sunlight and soil moisture do not show statistically significant differences on any biological characteristic of the population. The results also suggest that the autecology of I. parviflora in Western and Central Europe is not very well known and deserves further study.

  8. Hypoglycemic Activity of Fumaria parviflora in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Arash Khaki

    2013-02-01

    Full Text Available Purpose: Fumaria parviflora Lam (Fumariaceae has been used in traditional medicine in the treatment of several diseases such as diabetes. The present work was designed to evaluate the hypoglycaemic effects of methanolic extract (ME of F. parviflora in normal and streptozotocin-induced diabetic rats. Methods: The rats used were allocated in six (I, II, III, IV, V and VI experimental groups (n=5. Group I rats served as ‘normal control’ animals received distilled water and group II rats served as ‘diabetic control’ animals. Diabetes mellitus was induced in groups II, V and VI rats by intraperitoneal single injection of streptozotocin (STZ, 55 mg kg-1. Group V and VI rats were addi-tionally treated with ME (150 mg kg-1 day-1 and 250 mg kg-1 day-1, i.p. respectively 24 hour post STZ injection, for seven consecutive days. Groups III and IV rats received only ME 150 mg kg-1 day-1 and 250 mg kg-1 day-1, i.p. respectively for seven days. The levels of blood glucose were determined using a Glucometer. Results: Administra-tion of F. parviflora extract showed a potent glucose lowering effect only on streptozo-tocin (STZ induced diabetic rats below 100 mg/dl (P<0.001. However, no significant differences in the blood glucose levels were recorded between diabetic rats received 125 or 250 mg/kg of plant extracts. Conclusion: The findings of the study indicated that F. parviflora has significant hypoglycemic effect on STZ-induced diabetic rats with no effects on blood glucose levels of normal rats.

  9. In vitro and in vivo anthelmintic activity of extracts from Artemisia parviflora and A. sieversiana

    Directory of Open Access Journals (Sweden)

    Irum S.

    2017-09-01

    Full Text Available In the northern areas of Pakistan, the use of Artemisia based therapeutics is a common practice. Plants of genus Artemisia are known to possess anthelmintic and therapeutic effect. Infections caused by gastrointestinal nematodes are major threat to livestock industry across the world resulting in loss of production and indirect economic losses due to high cost of anthelmintic drugs. Present study was carried out to evaluate in vitro and in vivo effect of Artemisia sieversiana and Artemisia parviflora on Haemonchus contortus, a parasitic nematode of small ruminants. Methanolic plant extract was tested against three different developmental stages using an egg hatch assay, infective larvae and adult worm motility assay. Different concentrations were used for the bioassays and post exposure mortality was recorded after 8 hr for adult worms and infective larvae, while egg inhibition percentage was observed after 27 hr. A highly significant ability to inhibit the egg hatching (100 % was recorded for both plant extracts while, the highest activity for adult worm assay and larvicidal assay was 90 % for A. sieversiana. The highest activity for adult motility and larvicidal assay for A. parviflora was 89 % and 86.6 % respectively. For in vivo trials maximum parentage reduction was 77.0 % for A. sieversiana and 73.6 % for A. parviflora. It is concluded that selected plant extracts were effective in reducing worm burden in animals.

  10. Evaluation of hypoglycemic activity of the leaves of Malva parviflora in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Perez Gutierrez, Rosa Martha

    2012-04-01

    Malva parviflora (MP), known in Mexico by the name of "quesitos" or "malva", is popular due to its culinary and medicinal properties. Diabetic rats were treated with the hexane, chloroform and methanol extracts of the M. parviflora leaves for 28 days and a set of biochemical parameters were studied including: glucose level, total cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. We also looked into liver function by determining glucose-6-phosphatase, glucokinase and hexokinase activities, and the effect of the extracts on insulin level and protein glycation. As a result we found that with the hexane extract the blood glucose level, serum biochemical parameters, hepatic enzymes, thiobarbituric acid reactive substances, glycosylated hemoglobin, advanced glycation end products, and insulin level were restored in streptozotocin induced diabetic rats to nearly normal levels. We conclude that the hexane extract of M. parviflora leaves can efficiently inhibit insulin resistance, lipid abnormalities and oxidative stress, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in diabetes pathogenesis.

  11. Hepatoprotective Effects of Ixora parviflora Extract against Exhaustive Exercise-Induced Oxidative Stress in Mice

    Directory of Open Access Journals (Sweden)

    Chi-Chang Huang

    2013-09-01

    Full Text Available Ixora parviflora, a species of the Rubiaceae, is rich in polyphenols and flavonoids, and has been traditionally used as a folk medicine. An I. parviflora extract (IPE has great antioxidant activity in vitro, including a scavenging effect on superoxide radicals, reducing power, and ferrous ion-chelating ability. However, whether IPE is efficacious against oxidative damage in vivo is not known. The purpose of this study was to determine the protective effects of IPE treatment on hepatic oxidative stress and antioxidant defenses after exhaustive exercise in mice. Fifty male C57BL/6 mice (6 week old were randomly divided into five groups and designated a sedentary control with vehicle (C, and exhaustive exercise with vehicle (IPE0, low dosage (IPE10, medium dosage (IPE50 and high dosage (IPE100 of IPE at 0, 10, 50, and 100 mg/kg, respectively. After a single bout of exhaustive swimming exercise challenge, levels of blood ammonia and creatine kinase (CK, and hepatic superoxide dismutase (SOD protein expression, thiobarbituric acid-reactive substance (TBARS, and gp91phox, p22phox, and p47phox subunits of nicotinamide adenine dinucleotide phosphate (NADPH oxidase expressions in the IPE0 group were significantly affected compared to those of the C group, but they were all significantly inhibited by the IPE treatments. Results of the present in vivo study in mice indicate that I. parviflora extract possesses antioxidative and hepatoprotective potential following exhaustive exercise.

  12. Evaluación nutricional y sensorial del aceite de Proboscidea parviflora (uña de gato

    Directory of Open Access Journals (Sweden)

    Vázquez-Moreno, L.

    2003-03-01

    Full Text Available The seed of Proboscidea parviflora (cat´s claw has shown a great nutritional potential due to the good nutritional quality presented by its flour. In order to integrate the study of the seeds and to know a use for the oil, it was considered of interest to valuate biologically the crude oil and to sensory evaluate the patatoes fried in oil P. parviflora refined. Seeds of Proboscidea parviflora have shown a great potential due to the good nutritional quality of its flour. As part of the integral study, here is presented a crude oil biological evaluation and a sensorial evaluation of potatoes fried in refined P. parviflora oil. Diets were prepared adding 8, 11 and 16 % of crude oil and PER, NPR and the apparent digestibilty were determinated. PER values for each percentage were 2.7, 3.1 and 3 % respectively. While digestibilities were of 97, 98 and 97 % for each level of oil addition (there was not significative difference of PProboscidea parviflora presented good digestibility and high PER values comparable to the corn oil.La semilla de Proboscidea parviflora (uña de gato ha mostrado un gran potencial alimenticio debido, a la buena calidad nutricional que ha presentado la harina. Con el fin de integrar más el estudio de la semilla y de conocer el uso del aceite, se consideró de interés valorar biológicamente el aceite crudo y evaluar sensorialmente patatas fritas en aceite refinado de P. parviflora (uña de gato. El aceite de Proboscidea parviflora (uña de gato, fue evaluado con adición de 8, 11 y 16 % de aceite crudo en las dietas, mediante los ensayos de PER, NPR y digestibilidad aparente. Realízándose también el análisis sensorial de las patatas fritas en el aceite refinado. Obteniéndose un PER de 2.7, 3.1 y 3 % para cada nivel de aceite, valores altos con diferencia significativa de PProboscidea parviflora (uña de gato presentó buena digestibilidad, PER alto y comparable a la del aceite de maíz.

  13. A New Abietene Diterpene and Other Constituents from Kaempferia angustifolia Rosc.

    Directory of Open Access Journals (Sweden)

    Abdul Manaf Ali

    2011-04-01

    Full Text Available A new abietene diterpene, kaempfolienol (5S,6S,7S,9S,10S,11R,13S-abiet-8(14-enepenta-6,7,9,11,13-ol, 1, was isolated from a rhizome extract of Kaempferia angustifolia Rosc. along with the known compounds crotepoxide, boesenboxide, zeylenol, 2′-hydroxy-4,4′,6′-trimethoxychalcone, (24S-24-methyl-5α-lanosta-9(11,25-dien-3β-ol, β-sitosterol and β-sitosterol-3-O-β-D-glucopyranoside. The structures of all compounds were elucidated on the basis of mass spectroscopic and NMR data. Zeylenol (2, the major constituent of the plant, was derivatized into diacetate, triacetate and epoxide derivatives through standard organic reactions. The cytotoxic activity of compounds 1, 2 and the zeylenol derivatives was evaluated against the HL-60, MCF-7, HT-29 and HeLa cell lines.

  14. Anti-inflammatory effect of Fumaria parviflora leaves based on TNF-α, IL-1, IL-6 and antioxidant potential

    Science.gov (United States)

    Rizvi, Waseem; Fayazuddin, Mohammad; Singh, Ompal; Syed, Shariq Naeem; Moin, Shagufta; Akhtar, Kafil; Kumar, Anil

    2017-01-01

    Objective: In this study, we evaluated anti-inflammatory activity of leaves of Fumaria parviflora (F. parviflora) and underlying mechanisms by using in vivo models of inflammation. Material and Methods: Albino Wistar rats of either sex weighing 150 - 200 g were used. Soxhlet ethanol and aqueous extracts of leaves of F. parviflora (EFP and AFP) were prepared. The anti-inflammatory activity was studied using carrageenan-induced paw edema method and cotton pellet granuloma method. Levels of cytokines such as TNF-α, IL-6 and IL-1 and activity of antioxidant enzymes including catalase (CAT) and glutathione peroxidase (GPx) were estimated. Results: Leaves of F. parviflora demonstrated significant (p<0.001) decrease in paw edema in carrageenan-induced paw edema method. It diminished the serum tumour necrosis factor-α (TNF-α), IL-6 and IL-1 levels and also significantly attenuated the malondialdehyde (MDA) levels. The activity of CAT and GPx was increased in paw tissue. It also demonstrated significant decrease in granuloma formation in cotton pellet-induced granuloma method. Conclusion: Leaves of F. parviflora possess anti-inflammatory activity as they inhibit various cytokines and have antioxidant effects and free radical scavenging activity. PMID:28265545

  15. Utilization of the invasive plant Impatiens parviflora DC. by the snail Columella edentula Draparnaud in oak-hornbeam forests

    Directory of Open Access Journals (Sweden)

    Renata Piskorz

    2011-01-01

    Full Text Available This study investigated the extend to which the snail Columella edentula is more strongly associated with the small balsam Impatiens parviflora than with other plants in the herb layer of an oak-hornbeam forest, and to interpret the character of the interaction Impatiens parviflora - Columella edentula. Numbers of C. edentula and rates of colonization were compared on various plant species under natural and laboratory conditions. Seasonal variation in snail abundance on I. parviflora was observed on permanent plots. The leaf injuries caused by C. edentula were localized in respect of the morphological and anatomical structure of leaves. The results show that I. parviflora is one of the plant species of the herb layer that are most abundantly colonized by this snail in oak-hornbeam forest. Snail finds a plant particularly suitable as a place for resting. The most favoured attachment site is on the underside of the leaf, along the midrib, which provides the highest and relatively stable humidity, as well as protection from direct sunlight and predators. I. parviflora is also a food for the snails, but they do not eat these fragments of leaves where calcium carbonate is accumulated.

  16. Activity of Kaempferia pandurata (Roxb.) rhizome ethanol extract against MRSA, MRCNS, MSSA, Bacillus subtilis and Salmonella typhi.

    Science.gov (United States)

    Sukandar, Elin Yulinah; Sunderam, Nethiyakalyani; Fidrianny, Irda

    2014-01-01

    Temu kunci (Kaempferia pandurata (Roxb.)) has a number of benefits and one of these is antibacterial. The rhizome is said to have antibacterial activity against Streptococcus mutans, Lactocillus sp. and Candida albicans. The aim of the study is to test the antibacterial activity of Kaempferia pandurata (Roxb.) rhizome ethanol extract on methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase negative Staphylococci (MRCNS), methicillin-sensitive Staphylococcus aureus (MSSA), Bacillus subtilis and Salmonella typhi. Antimicrobial activity of the extract was assayed by the microdilution method using Mueller Hinton Broth with sterilized 96 round-bottomed microwells to determine the Minimum Inhibitory Concentration (MIC) as well as to determine the time-kill activity. The MIC of the extract was 16 ppm for both Bacillus subtilis and MRSA; 8 ppm for both MSSA and Salmonella typhi and 4 ppm for MRCNS. Ethanol extract of Kaempferia pandurata (Roxb.) showed antibacterial activity against all the tested bacteria and was the most potent against MRCNS, with MIC 4 ppm. The killing profile test of the extract displayed bactericidal activity at 8-16 ppm against MRSA, MSSA, Bacillus subtilis and Salmonella typhi and bacteriostatic activity at 4 ppm towards MRCNS.

  17. Neuroprotective Effect of Ethanol Extract of Leaves of Malva parviflora against Amyloid-β- (Aβ-) Mediated Alzheimer's Disease.

    Science.gov (United States)

    Aslam, Muhammad; Sial, Ali Akbar

    2014-01-01

    Malva parviflora L. possesses significant antioxidant potential. This study was conducted to evaluate the neuroprotective effect of ethanol extract of the leaves of Malva parviflora against amyloid-β- (Aβ-) mediated Alzheimer's disease. In Morris water maze model, the extract significantly restored the defected memory of amyloid-β injected mice (P < 0.01). The reduced levels of brain antioxidant enzymes such as glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase were also restored significantly to similar levels as seen in normal control mice (P < 0.01). The levels of lipid peroxidase were decreased significantly in treatment group mice when compared to Alzheimer group mice (P < 0.01). So, this study showed that ethanol extract of the leaves of Malva parviflora possesses neuroprotective activity in mice.

  18. [Effect of Invasive Herb Species on the Structure of Soil Yeast Complexes in Mixed Forests Exemplified by Impatiens parviflora DC].

    Science.gov (United States)

    Glushakova, A M; Kachalkin, A V; Chernov, I Yu

    2015-01-01

    Yeast abundance and diversity in a mixed forest sod-podzol soil under Impatiens parviflora DC plants was studied in comparison with unimpaired aboriginal herbaceous plants typical of the Mid-Russian secondary, after-forest meadow. The study was carried out throughout the vegetation period. Standard microbiological plating techniques revealed 36 yeast species. Typical pedobiotic (Cryptococcus podzolicus, Wickerhamomyces anomalus) and eurybiotic yeast species (Rhodotorula mucilaginosa) predominated in both biotopes. The relative abundance of the autochthonous soil yeast species Cryptococcus podzolicus was higher in the soil under aboriginal herbs than under Impatiens parviflora. Sites with aboriginal vegetation were also characterized by high abundance of the pedogamous species Schwanniomyces castelli and Torulaspora delbrueckii. The share of yeastlike Trichosporon fungi with high hydrolytic activity was considerably higher under adventitious plants Impatiens parviflora, as well as in the previously studied soil under Heracleum sosnowskyi.

  19. Generic status of Quisqualis (Combretaceae, with notes on the taxonomy and distribution of Q. parviflora

    Directory of Open Access Journals (Sweden)

    M. Jordaan

    2011-12-01

    Full Text Available The taxonomic status of Quisqualis L., a genus closely related to and sometimes considered congeneric with Combretum Loefl., is discussed. The genus Quisqualis is maintained to accommodate selected African, Indian, Asian and Malesian species (including Q. indica L. and Q. parviflora Sond.. Diagnostic characters for Quisqualis include: leaves with abundant subepidermal crystalliferous idioblasts, each containing a large druse of calcium oxalate; leaves, stems and flowers with stalked glands but no scales; persistent petiole bases that develop into curved spines; petals well developed; hypanthium tubular or cylindrical, usually longer than 20 mm; stamens and style not or scarcely exserted; style adnate to hypanthium for more than half its length. Quisqualis shares a number of morphological similarities with Combretum Loefl. subgen. Cacoucia (Aubl. Exell & Stace sect. Poivrea (Comm. ex DC. G.Don. Some species of Combretaceae from West, West Central and East Africa have the style adnate to the upper hypanthium and display features reminiscent of both Quisqualis and Combretum. These species also have characters of their own and in the past were placed in different sections under Combretum. It is suggested that at least some of these species may be best classified in genera distinct from Combretum and Quisqualis, one of which is Campylogyne Hemsley. Combretum s.str. is defined on the basis of a combination of characters and includes species of which the upper hypanthium is variable in shape, but when tubular or cylindrical, then always shorter than 20 mm. Other diagnostic characters include: stamens exserted well beyond petals; style exserted and free, but when shortly adnate to upper hypanthium (only at the base or for a short distance, then stamens long-exserted. It is suggested that different pollination strategies have developed independently in the Combretum–Quisqualis clade, resulting in convergent morphological trends in floral morphology

  20. Species and tissue-specificity of prokinetic, laxative and spasmodic effects of Fumaria parviflora

    Directory of Open Access Journals (Sweden)

    Najeeb-ur-Rehman

    2012-03-01

    Full Text Available Abstract Background Fumaria parviflora Linn. (Fumariaceae, is a small branched annual herb found in many parts of the world including Saudi Arabia and Pakistan. This study was designed to provide pharmacological basis for the medicinal use of Fumaria parviflora in gut motility disorders. Methods The in-vivo prokinetic and laxative assays were conducted in mice. Isolated intestinal preparations (ileum and jejunum from different animal species (mouse, guinea-pig and rabbit were separately suspended in tissue baths containing Tyrode's solution bubbled with carbogen and maintained at 37°C. The spasmogenic responses were recorded using isotonic transducers coupled with PowerLab data acquisition system. Results The aqueous-methanol extract of Fumaria parviflora (Fp.Cr, which tested positive for the presence of alkaloids, saponins, tannins and anthraquinones showed partially atropine-sensitive prokinetic and laxative activities in the in-vivo in mice at 30 and 100 mg/kg. In the in-vitro studies, Fp.Cr (0.01-1 mg/ml caused a concentration-dependent atropine-sensitive stimulatory effect both in mouse tissues (jejunum and ileum, and rabbit jejunum but had no effect in rabbit ileum. In guinea-pig tissues (ileum and jejunum, the crude extract showed a concentration-dependent stimulatory effect with higher efficacy in ileum and the effect was partially blocked by atropine, indicating the involvement of more than one types of gut-stimulant components (atropine-sensitive and insensitive. This could be a plausible reason for the greater efficacy of Fp.Cr in gut preparations of guinea-pig than in rabbit or mouse. Conclusions This study shows the prokinetic, laxative and spasmodic effects of the plant extract partially mediated through cholinergic pathways with species and tissue-selectivity, and provides a sound rationale for the medicinal use of Fumaria parviflora in gut motility disorders such as, indigestion and constipation. This study also suggests using

  1. OPTIMASI YIELD ETIL P METOKSISINAMAT PADA EKSTRAKSI OLEORESIN KENCUR (Kaempferia galanga MENGGUNAKAN PELARUT ETANOL

    Directory of Open Access Journals (Sweden)

    Eko Setyawan

    2013-05-01

    Full Text Available Kencur (Kaempferia galanga L. banyak digunakan sebagai bahan baku obat tradisional (jamu, fitofarmaka, industri kosmetika, industri makanan, dan industri insektisida. Minyak atsiri rimpang kencur mengandung etil sinnamat dan metil p-metoksi sinamat (EPMS. Ekstraksi oleoresin kencur dilakukan dengan etanol sebagai pelarut. Optimasi yield EPMS diteliti terhadap perbandingan massa serbuk kering kencur dan etanol dan waktu ekstraksi. Perbandingan kencur : etanol yang digunakan adalah 1 : 2, 1 : 3, dan 1 : 4. Waktu operasi yang digunakan adalah 2 s.d 5 jam. Tahapan proses ekstraksi oleoresin kencur adalah preparasi bahan, ekstraksi, evaporasi dan pemurnian. Oleoresin hasil ekstraksi dianalisis dengan uji GC-MS untuk mengetahui kandungan EPMS dan kandungan minyak atsiri lain dalam oleoresin kencur. Oleoresin hasil ekstraksi berwarna coklat tua dengan yield antara 6-8%. Kandungan EPMS dalam oleoresin bervariasi antara 67,77 hingga 87,57%. Massa oleoresin optimal hasil ekstraksi adalah 6,09 gram pada perbandingan kencur dan etanol 1:4 selama 4 jam. Pendekatan persamaan hasil ekperimen ekstraksi kencur dan etanol menghasilkan titik optimal EPMS pada waktu ekstraksi 3,62 dengan massa EPMS 6,04 gram Lesser galangal (Kaempferia galanga L. is widely used as a traditional medicine (herbal medicine, fitofarmaka, cosmetics industry, food industry, and insecticide industry. The essential oils in the Lesser galangal contain ethyl sinnamat and methyl p-methoxy cinnamic (EPMS. The oleoresin extraction of Lesser galangal was performed using ethanol as a solvent. Optimization of the EPMS yield was investigated to dry powder mass ratio of Lesser galangal and ethanol as well as the extraction time. The ratio of Lesser galangal : ethanol was  varied from 1: 2, 1: 3 and 1: 4. The chosen operating time were 2 to 5 hours. The procedure of the oleoresin extraction process of Lesser galangal includes the preparation of materials, extraction, evaporation and

  2. Thiaminase activities and thiamine content of Pteridium aquilinum, Equisetum ramosissimum, Malva parviflora, Pennisetum clandestinum and Medicago sativa.

    Science.gov (United States)

    Meyer, P

    1989-06-01

    Thiaminase type 1 and 2 activities and thiamine content of five plants were determined. Of these Pteridium aquilinum and Equisetum ramosissimum were found to have considerably more thiaminase activity and lower thiamine content than Malva parviflora, Pennisetum clandestinum and Medicago sativa.

  3. Leaf photosynthetic and solar-tracking responses of mallow, Malva parviflora, to photon flux density.

    Science.gov (United States)

    Greer, Dennis H; Thorpe, Michael R

    2009-10-01

    Malva parviflora L. (mallow) is a species that occupies high-light habitats as a weedy invader in orchards and vineyards. Species of the Malvaceae are known to solar track and anecdotal evidence suggests this species may also. How M. parviflora responds physiologically to light in comparison with other species within the Malvaceae remains unknown. Tracking and photosynthetic responses to photon flux density (PFD) were evaluated on plants grown in greenhouse conditions. Tracking ability was assessed in the growth conditions and by exposing leaves to specific light intensities and measuring changes in the angle of the leaf plane. Light responses were also determined by photosynthesis and chlorophyll fluorescence. Leaves followed a heliotropic response which was highly PFD-dependent, with tracking rates increasing in a curvilinear pattern. Maximum tracking rates were up to 20 degrees h(-1) and saturated for light above 1,300 micromol (photons) m(-2) s(-1). This high-light saturation, both for tracking (much higher than the other species), and for photosynthesis, confirmed mallow as a high-light demanding species. Further, because there was no photoinhibition, the leaves could capture the potential of an increased carbon gain in higher irradiance by resorting to solar tracking. Modelling suggested the tracking response could increase the annual carbon gain by as much as 25% compared with leaves that do not track the sun. The various leaf attributes associated with solar tracking, therefore, help to account for the success of this species as a weed in many locations worldwide.

  4. Pharmacognostic studies of stem, roots and leaves of Malva parviflora L.

    Institute of Scientific and Technical Information of China (English)

    Shehla Akbar; Uzma Hanif; Jaffar Ali; Saiqa Ishtiaq

    2014-01-01

    Objective:To establish quality control parameters of a locally occurring medicinal plant, Malva parviflora which is utilized as folk medicine in Sialkot area in Pakistan. Methods:In pharmacognostic studies different types of evaluations were carried out that focus on microscopic, macroscopic, fluorescence analysis and organoleptic evaluations. Results:The distinguishing characters of stem were the presence of parenchyma, cork cells, irregular shape calcium oxalate crystals, simple and compound starch granules and fusiform fibers with pits. Root microscopic characters were presence of simple and spherical starch granules with rounded or slit hilum, groups of lignified xylem fibers, reticulate vessels, and sieve tissues. Leaves microscopy indicated the presence of paracytic stomata, lignified fibers having pits, spiral and annular vessels, numerous sclereids while in fruit microscopy epicarp, thin walled cells endocarp, thin walled parenchyma and collenchyma of mesocarp and abundant thick walled endospermic cells containing aleurone grains and micro rosette crystals. Macroscopic study of leaves showed, 5-7 lobed reniform-shape, glabrous-surface, reticulate-venation in the leaves. Macroscopic features of roots showed type of root-taproot, surface-glabrous and stem was 1-10 dm tall simple to branched and may be prostrate or ascending. Similarly fruit was of schizocarp type. Conclusions: This study provides the scientific data for the proper identification and establishment of standards for the use of Malva parviflora.

  5. Effects of Kaempferia galanga L. and ethyl-p-methoxycinnamate (EPMC

    Directory of Open Access Journals (Sweden)

    Wanna Sirisangtragul

    2011-08-01

    Full Text Available Kaempferia galanga L. (K. galanga L., belonging to the Zingiberaceae family, has been widely used in Thai traditionalmedicine for treatment of hypertension, asthma, rheumatism, indigestion, cold and headache and relief abdominal pain.This study aimed to investigate the effect of dichloromethane extract of K. galanga L. (DEK and its major component ethylp-methoxycinnamate (EPMC on hepatic microsomal cytochrome P450s enzyme activities in mice. After oral administrationwith DEK (100 mg/kg which is equivalent to EPMC 80 mg/kg, EPMC (120 and 160 mg/kg for 28 consecutive days, themicrosomal P450 content decreased. The CYP1A1 and CYP2B activities significantly increased, whereas CYP2E1 activity wassignificant inhibited only at the highest concentration of EPMC (160 mg/kg. None of the treatments did affect CYP1A2 andCYP3A4 activity when compared to the control group. The results indicated that K. galanga L. and its active compound,EPMC may participate in herbal-drug interaction and may also increase risk of toxicity and chemical carcinogenesis fromdrugs and compounds that are metabolized via CYP1A1, CYP2B and CYP2E1.

  6. Phytochemicals from Kaempferia angustifolia Rosc. and Their Cytotoxic and Antimicrobial Activities

    Directory of Open Access Journals (Sweden)

    Sook Wah Tang

    2014-01-01

    Full Text Available Phytochemical investigation on rhizomes of Kaempferia angustifolia has afforded a new abietene diterpene, kaempfolienol (1 along with crotepoxide (2, boesenboxide (3, 2′-hydroxy-4,4′,6′-trimethoxychalcone (4, zeylenol (5, 6-methylzeylenol (6, (24S-24-methyl-5α-lanosta-9(11, 25-dien-3β-ol (7, sucrose, β-sitosterol, and its glycoside (8. The structures of the compounds were elucidated on the basis of spectroscopic methods (IR, MS, and NMR. Isolation of 6-methylzeylenol (6, (24S-24-methyl-5α-lanosta-9(11, 25-dien-3β-ol (7, and β-sitosterol-3-O-β-D-glucopyranoside (8 from this plant species has never been reported previously. The spectroscopic data of (7 is firstly described in this paper. Cytotoxic screening indicated that most of the pure compounds tested showed significant activity with (4 showing the most potent activity against HL-60 (human promyelocytic leukemia and MCF-7 (human breast cancer cell lines. However, all extracts and most of the pure compounds tested were found to be inactive against HT-29 (human colon cancer and HeLa (human cervical cancer cell lines. Similarly, none of the extracts or compounds showed activity in the antimicrobial testing.

  7. Chemogeography and antimicrobial activity of essential oils from Geijera parviflora and Geijera salicifolia (Rutaceae): two traditional Australian medicinal plants.

    Science.gov (United States)

    Sadgrove, Nicholas J; Gonçalves-Martins, Maximilien; Jones, Graham L

    2014-08-01

    Essential oils were hydrodistilled from 27 specimens of Geijera parviflora Lindl., (Rutaceae) and nine specimens of Geijera salicifolia Schott, collected over a wide geographic range in New South Wales, Queensland and South Australia. Essential oils were produced by traditional hydrodistillation and characterised using GC-MS. From one specimen a serendipitous discovery was made of bioactive coumarins dissolved in the hydrosol, which were the coumarins isopsoralen, xanthyletine and osthole. These coumarins were not present in the essential oil from that specimen. Using essential oil composition from all specimens, principal component analysis (PCA) demonstrated nine clusters for G. parviflora and three for G. salicifolia. Some clusters are representative of previously described chemotypes and some are reflective of possible chemotypes requiring more comprehensive sampling for confirmation. Thus, another three or four possible chemotypes of G. parviflora and one of G. salicifolia have been tentatively identified. Using micro-titre plate broth dilution assays, antibacterial and antifungal activity of all chemotypes was investigated. In this regard, the 'green oil' chemotype, restricted to G. parviflora, with major components linalool, geijerene/pregeijerene, 1,8-cineol and bicyclogermacrene, demonstrated the highest antimicrobial and free radical scavenging activity. Thus, in the light of traditional use reports of local analgaesia and bioactivity demonstrated in the current study, oils from select chemotypes of G. parviflora may be useful in suitably compounded lotions and creams designed for topical antimicrobial applications and local pain relief. In addition, because major components are known for insecticidal activities, such lotions may also be useful as topically applied insect repellents.

  8. タイ天然薬物Phayom(Shorea roxburghii)およびKrachai Dum (Kaempferia parviflora)からの難治性疾患治療薬先導物質の探索

    OpenAIRE

    チャイペック, サワニ

    2012-01-01

    学位の種類:薬学  学位授与年月日:平成24年3月22日  主査:村岡, 修 教授  報告番号:甲第1080号  学内授与番号:薬第100号 NDL書誌ID:024187500

  9. Ethyl p-methoxycinnamate from Kaempferia galanga inhibits angiogenesis through tyrosine kinase

    Directory of Open Access Journals (Sweden)

    Juni Ekowati

    2015-04-01

    Full Text Available Background Many tumors express on their receptor tyrosine kinases vascular endothelial growth factor activity associated with angiogenesis. Inhibition of angiogenesis through reduction of tyrosine kinase activity is a promising strategy for cancer therapy. The present study aimed to determine the mechanism and potency of ethyl p-methoxycinnamate (EPMC isolated from Kaempferia galanga as angiogenesis inhibitor. Methods A laboratory experimental study was conducted using chorio-allantoic membranes (CAMs of nine-day old chicken eggs induced by 60ng basic fibroblast growth factor (bFGF. Ethyl p-methoxycinnamate (EPMC potency was determined at dosages of 30, 60, 90 and 120 mg and compared with celecoxib 60 mg as reference drug and one negative bFGF-induced control group. Neovascularization and endothelial cell count in CAM blood vessels were evaluated. To predict the antiangiogenic mechanism of EPMC, a docking study was performed with the Molegro Virtual Docker program on tyrosine kinase as receptor (PDB 1XKK. Results Angiogenesis stimulation by bFGF was prevented significantly (p<0.05 by EPMC at dosages of 30, 60, 90 and 120 mg and this activity was dose dependent. Molecular docking showed interaction between EPMC functional groups and tyrosine kinase amino acids at Met766, Met793, Thr854, Thr790, Gln791 and Ala743. There was an association between EPMC antiangiogenic activity and docking study results. Conclusions Ethyl p-methoxycinnamate is a potential new angiogenesis inhibitor through interaction with tyrosine kinase. EPMC could be a promising therapeutic agent for treatment of angiogenesis-related diseases.

  10. Structure elucidation of β-sitosterol with antibacterial activity from the root bark of Malva parviflora.

    Science.gov (United States)

    Ododo, Mesfin Medihin; Choudhury, Manash Kumar; Dekebo, Ahmed Hussen

    2016-01-01

    The powder of root bark of Malva parviflora (Malvaceae) was successively extracted with petroleum ether (b.p. 60-80 °C), chloroform and ethanol. The chloroform extract showed antibacterial activity against Staphylococcus aureus and Escherichia coli, whereas the ethanolic extract showed antibacterial activity against only S. aureus. The chloroform extract, after column chromatographic separation on silica gel using petroleum ether:chloroform (3:1) as eluent, furnished 98 mg of white crystalline compound. The yield of the compound is 0.316 % (w/w). The compound has a melting point of 134-136 °C and the Rf value 0.56 in benzene:chloroform:acetone (1:15:1) on silica gel TLC. The compound was characterized as β-sitosterol by physical properties, chemical test, spectral analysis (FTIR, NMR and MS) and comparing the data obtained from the literature.

  11. RESPUESTAS ORGANOGÉNICAS in vitro DE Nolina parviflora (H.B.K.) Hemsl

    OpenAIRE

    Andrés Flores García; José Guadalupe Álvarez Moctezuma; José Luis Rodríguez de la O; Alejandro Corona Ambris

    2009-01-01

    Dentro de la familia Nolinaceae se encuentra Nolina parviflora (H.B.K.) Hemsl. (sotolín), planta arborescente que se ubica en zonas cálidas y secas de los estados de Hidalgo, México, Puebla, San Luís Potosí y Veracruz. Se ha reportado un uso medicinal y de ornato para el género, además de guardar importancia por ser eslabón de materia prima que contribuye a la economía de los productores de algunas zonas áridas y semiáridas de nuestro país. La especie guardaba la incógnita de su propagación i...

  12. Geographic variation in the flood-induced fluctuating temperature requirement for germination in Setaria parviflora seeds.

    Science.gov (United States)

    Mollard, F P O; Insausti, P

    2011-07-01

    Our aim was to search for specific seed germinative strategies related to flooding escape in Setaria parviflora, a common species across the Americas. For this purpose, we investigated induction after floods, in relation to fluctuating temperature requirements for germination in seeds from mountain, floodplain and successional grasslands. A laboratory experiment was conducted in which seeds were imbibed or immersed in water at 5°C. Seeds were also buried in flood-prone and upland grasslands and exhumed during the flooding season. Additionally, seeds were buried in flooded or drained grassland mesocosms. Germination of exhumed seeds was assayed at 25°C or at 20°C/30°C in the dark or in the presence of red light pulses. After submergence or soil flooding, a high fraction (>32%) of seeds from the floodplain required fluctuating temperatures to germinate. In contrast, seeds from the mountains showed maximum differences in germination between fluctuating and constant temperature treatment only after imbibition (35%) or in non-flooded soil conditions (40%). The fluctuating temperature requirement was not clearly related to the foregoing conditions in the successional grassland seeds. Maximum germination could also be attained with red light pulses to seeds from mountain and successional grasslands. Results show that the fluctuating temperature requirement might help floodplain seeds to germinate after floods, indicating a unique feature of the dormancy of S. parviflora seeds from floodplains, which suggests an adaptive advantage aimed at postponing emergence during inundation periods. In contrast, the fluctuating temperature required for germination among seeds from mountain and successional grasslands show its importance for gap detection. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Muerte celular inducida por condiciones ambientales adversas en Calibrachoa parviflora (Petunia

    Directory of Open Access Journals (Sweden)

    Daniela Montes Berrueta

    2012-03-01

    Full Text Available Se ha descrito que condiciones ambientales extremas tales como altas temperaturas, luz ultravioleta y el efecto invernadero, alteran la tasa de crecimiento de las plantas. En este trabajo se investigó el efecto agudo de dos condiciones ambientales extremas tales como la limitación de nutrientes y la acidificación del suelo con ácido sulfúrico, un compuesto comúnmente depositado en los suelos como consecuencia de la llamada lluvia ácida, sobre la tasa de muerte y proliferación celular en petunias (Calibrachoa parviflora. Para tales efectos, grupos de petunias fueron sometidas a tres condiciones diferentes: grupo A o control, mantenida en condiciones óptimas y de suministro de nutrientes, grupo B en ausencia de nutrientes y de luz natural, y grupo C expuestas a agua acidificada con ácido sulfúrico. En un seguimiento hasta 72 horas, se analizaron muestras de pétalos, hojas y tallos de cada una de las plantas y, posterior a la extracción de los núcleos, estos fueron teñidos con ioduro de propidio, un agente intercalante del ADN, y analizados mediante citometría de flujo y microscopía de fluorescencia. Los resultados muestran que ambas condiciones extremas generan un desbalance en el proceso de muerte/sobrevida de las petunias, pero a diferencia de las plantas del grupo B, las plantas del grupo C no incrementaron la tasa de proliferación celular. Estos resultados sugieren que las plantas que crecen en suelos ácidos pierden la capacidad compensatoria ante la señal de estrés que se genera a consecuencia de la exposición aguda a concentraciones tóxicas de ácido sulfúrico. Cell death induced by adverse environmental conditions in Calibrachoa parviflora (petunia Abstract It has been previously reported that extreme environmental conditions such as high temperatures, ultraviolet light and the greenhouse effect, alter the rate of growth in plants. In this study we investigated the acute effect of two extreme environmental conditions

  14. SYNTHESIS OF p-METHOXY-CYNNAMIL- p-METOXYCINAMATE FROM ETHYL p-METHOXYCINAMAT WAS ISOLATED FROM DRIED RHIZOME Kaempferia Galanga L AS SUNSCREEN COMPOUND

    Directory of Open Access Journals (Sweden)

    Titik Taufikkurohmah

    2010-06-01

    Full Text Available Synthesis of p-methoxy-cynnamil-p-methoxy-cinnamate, (PMS2O from ethyl-p-methoxy-cinnamate (EPMS from dry rhizome of kaempferia galanga L as sunscreen compound have been done. Isolation of EPMS was done by percholation using ethanol 96 % and recrystallitation using methanol to have 2.2 % yield. Hydrolysis of EPMS using alcoholic KOH resulted methoxycinnamic acid (APMS of 90.26 % yield. Reduction EPMS using lithium aluminium hydride in dry ether would give p-methoxycinnamoyl alcohol (PMS-OH of 41.98 % yield. Then reaction of p-methoxycinnamoyl chloride (PMS-Cl and PMS-OH in chloroform would produce p-methoxycinnamoyl p-methoxycinnamate ((PMS2O of 1.77 % yield. All compound were identified by TLC and several spectrometry methodes i.e. U.V Vis, IR, 1H-NMR and GC-MS   Keywords: esther cinnamate, sunscreen, Kaempferia galanga.

  15. Isolation and physico-chemical characterization of Butea parviflora seed oil

    Directory of Open Access Journals (Sweden)

    Kaki, S. S.

    2016-09-01

    Full Text Available The seeds of Butea parviflora were investigated for oil extraction and the oil was studied for complete physico-chemical properties. The fatty acid profile of the seed oil showed oleic acid (18:1 at 27.5%, linoleic acid (18:2 at 26.4%, palmitic acid (16:0 at 16.1% and behenic acid (22:0 at 14.1% as the major fatty acids. The physico-chemical characteristics of the seed oil were studied for parameters such as free fatty acids (0.71%, iodine value (76.2 g/100g, peroxide value (5.95 ppm, saponification value (177.32 mg KOH/g, unsaponifiable matter (0.82%, phosphorous content (197 ppm, triglyceride analysis, tocols, specific gravity and refractive index following standard procedures.Se ha estudiado la extracción de aceite de semillas de Butea parviflora así como las características físico-químicas completas del aceite. El perfil de ácidos grasos está compuesto de un 27,5% de ácido oleico (18:1, 26,4% de ácido linoleico (18:2, 16,1% de ácido palmítico (16:0 y 14.1% de behénico (22:0 como principales ácidos grasos. Se han estudiado las características físico-químicas del aceite de las semilla tales como los ácidos grasos libres (0,71%, índice de yodo (76,2 g/100 g, índice de peróxido (5,95 ppm, índice de saponificación (177,32 mg KOH/g, materia insaponificable (0,82%, contenido en fósforo (197 ppm, análisis de triglicéridos, gravedad específica e índice de refracción, siguiendo los protocolos recogidos en procedimientos estandarizados.

  16. The effect of wood ant Formica rufa nests on distribution and growth of Impatients parviflora

    Science.gov (United States)

    Holec, Michal; Holcová, Diana; Frouz, Jan

    2016-04-01

    The effect of wood ants Formica rufa on distribution of introduces invasive jewelweed Impatiens parviflora was studied in oak forest in North west of the Czech Republic. Jewelweed occured only rarely in the forest floor, the average density was 3.2 plant m-2 here while on and around the ant nest mounds the jewelweed density reached 85.4 plant m-2. Jevelweed growing on the nest mounds were also significantly taller, bigger, with more flowers and produced more seeds that plants in surrounding forest floor. Better growth of jevelweed in ant nests apparently corresponds with significantly higher content of nitrates and available phosporus in the nest compare to forest floor. Seed collection experiment show that ants do not selectively collect jevelweed seeds but may collect them randomly in about the same rates as other organic material. This non targeted collection however may be sufficient to make sure that some seeds get close or in to the nest where population can grow vigorously due to suitable soil conditions.

  17. Purification and characterization of three antifungal proteins from cheeseweed (Malva parviflora).

    Science.gov (United States)

    Wang, X; Bunkers, G J; Walters, M R; Thoma, R S

    2001-04-20

    Three potent antimicrobial proteins were purified from cheeseweed (Malva parviflora) seeds. These antimicrobial proteins, named CW-3, CW-4, and CW-5, showed different antimicrobial spectrum and potency compared to the two heterologous antimicrobial proteins (CW-1 and CW-2) purified previously. CW-3 and CW-4 possess antimicrobial activities against Phytophthora infestans (Pi), but not Fusarium graminearum (Fg). A database search indicated that CW-3 shares high homology to cotton vicilin, an abundant seed storage protein. CW-4 shares homology to 2S albumin, another seed storage protein from cotton. CW-5 has antimicrobial activity against Fg, but no activity against Pi was observed at protein concentration up to 50 ppm. Under low salt condition, CW-5 showed potent antimicrobial activity against Fg, but under high salt condition, the antimicrobial activity was drastically diminished. Database search indicated that CW-5 has high homology to a lipid transfer protein from grape. The IC(50) values of the three purified antimicrobial proteins under both low and high salt conditions were determined. The isolation of five antimicrobial proteins for the first time from a single plant source provides further understanding of the plant innate defense system and insight on how plants evolve their complex and complementary antimicrobial system that is important in the early stage of development.

  18. Antioxidant Activity of Flavonoids Isolated From the Fruits of Xylopia parviflora (A. Rich. Benth

    Directory of Open Access Journals (Sweden)

    AT Tchinda

    2014-10-01

    Full Text Available The present study evaluates the antioxidant activity of the different flavonoids of the fruits of Xylopia parviflora used in Cameroon as spice in common traditional dishes. The fruits were successively extracted with hexane and methanol. The isolation of flavonoids was guided by the DPPH-TLC technique. The methanol crude extract and isolated compounds were screened for antioxidant and free radical scavenging activities using DPPH radical-scavenging, β-carotene/linoleic acid and ferric reducing antioxidant power (FRAP assays. The total phenolic content of the methanol crude extract was determined by Folin–Ciocalteu method. The DPPH-TLC technique led to the isolation of (+-catechin (1, kaempferol 3-O-arabinofuranoside (2 and quercetin 3-O-arabinofuranoside (3 identified by NMR and mass spectra analysis. In the colorimetric DPPH test, compound 1 had the same activity (EC50 8.1µg/ml as butylated hydroxytoluene (BHT used as standard while compound 3 and the methanol crude extract were less active (EC50 17.2µg/ml. Compound 2 was completely inactive. The total phenolic content of the fruit extracts was 113.03 mg gallic acid equivalents per g of extract. In the carotene bleaching test at the highest concentration of 100µg/mL, the order of inhibition of β-carotene discoloration was BHT > crude extract > quercetin 3-O-arabinofuranoside (3 > catechin (1 > kaempferol 3-O- arabinofuranoside (2. In the reducing power assay, compound 3 was more active at concentrations 40-100µg/mL. The HPLC analysis of the methanol crude extract revealed the presence of compounds 1-3 and unidentified phenolic compounds. The antioxidant activity of the methanol extract is probably due to the presence of compounds 1 and 3.

  19. Screening of a new cadmium hyperaccumulator, Galinsoga parviflora, from winter farmland weeds using the artificially high soil cadmium concentration method.

    Science.gov (United States)

    Lin, Lijin; Jin, Qian; Liu, Yingjie; Ning, Bo; Liao, Ming'an; Luo, Li

    2014-11-01

    A new method, the artificially high soil cadmium (Cd) concentration method, was used to screen for Cd hyperaccumulators among winter farmland weeds. Galinsoga parviflora was the most promising remedial plant among 5 Cd accumulators or hyperaccumulators. In Cd concentration gradient experiments, as soil Cd concentration increased, root and shoot biomass decreased, and their Cd contents increased. In additional concentration gradient experiments, superoxide dismutase and peroxidase activities increased with soil Cd concentrations up to 75 mg kg(-1) , while expression of their isoenzymes strengthened. Catalase (CAT) activity declined and CAT isoenzyme expression weakened at soil Cd concentrations less than 50 mg kg(-1) . The maxima of Cd contents in shoots and roots were 137.63 mg kg(-1) and 105.70 mg kg(-1) , respectively, at 100 mg kg(-1) Cd in soil. The root and shoot bioconcentration factors exceeded 1.0, as did the translocation factor. In a field experiment, total extraction of Cd by shoots was 1.35 mg m(-2) to 1.43 mg m(-2) at soil Cd levels of 2.04 mg kg(-1) to 2.89 mg kg(-1) . Therefore, the artificially high soil Cd concentration method was effective for screening Cd hyperaccumulators. Galinsoga parviflora is a Cd hyperaccumulator that could be used to efficiently remediate Cd-contaminated farmland soil.

  20. Composition and cytotoxic activity of essential oils from Xylopia aethiopica (Dunal) A. Rich, Xylopia parviflora (A. Rich) Benth.) and Monodora myristica (Gaertn) growing in Chad and Cameroon

    Science.gov (United States)

    2014-01-01

    Background Cancer has become a global public health problem and the search for new control measures is urgent. Investigation of plant products such as essential oils from Monodora myristica, Xylopia aethiopica and Xylopia parviflora might lead to new anticancer therapy. In this study, we have investigated the antineoplastic activity of essential oils from fruits of these plants growing in Chad and Cameroon. Methods The essential oils obtained by hydrodistillation of fruits of Monodora myristica, Xylopia aethiopica and Xylopia parviflora collected in Chad and Cameroon were analyzed by GC-FID and GC-MS and investigated for their antiproliferative activity against the breast cancer cell line (MCF7). Results Overall, monoterpenes were mostly found in the six essential oils. Oils from X. aethiopica and X. parviflora from Chad and Cameroon mainly contain β-pinene at 24.6%, 28.2%, 35.7% and 32.9% respectively. Monodora myristica oils from both origins contain mainly α-phellandrene at 52.7% and 67.1% respectively. The plant origin did not significantly influence the chemical composition of oils. The six essential oils exerted cytotoxic activity against cancer (MCF-7) and normal cell lines (ARPE-19), with more pronounced effect on neoplastic cells in the majority of cases. The highest selectivity was obtained with the essential oils of X. parviflora from Chad and Cameroon (5.87 and 5.54) which were more cytotoxic against MCF-7 than against normal cell line (ARPE-19) with IC50 values of 0.155 μL/mL and 0.166 μL/mL respectively. Conclusions Essential oils from fruits of Monodora myristica, Xylopia aethiopica and Xylopia parviflora have shown acceptable antineoplastic potency, and might be investigated further in this regard. PMID:24708588

  1. Antibacterial activity of Kaempferia rotunda rhizome lectin and its induction of apoptosis in Ehrlich ascites carcinoma cells.

    Science.gov (United States)

    Kabir, Syed Rashel; Reza, Md Abu

    2014-03-01

    The tuberous rhizome Kaempferia rotunda Linn. has been used as food and traditional medicinal plant, and the purified K. rotunda lectin (KRL) showed antiproliferative activity against Ehrlich ascites carcinoma cells [1]. In the present study, KRL showed agglutination activity against Escherichia coli and Staphylococcus aureus, with partial inhibition of their growth. MTT assay was used to investigate the effect of KRL on EAC cells in vitro in RPMI-1640 medium, and it was found that lectin inhibited 6.2-50.5% cell growth at the range of 7.5-120 μg/ml protein concentration. The cell cycle arrest at G0/G1 phase of EAC cells was also determined by flow cytometry after treatment with lectin. The apoptotic cell morphological changes of the treated EAC cells were confirmed by fluorescence and optical microscope. In the presence of caspase-3 inhibitor, the cell growth inhibition of the lectin was reduced significantly. RT-PCR was used to evaluate the expression of apoptosis-related genes, bcl-2, bcl-X, and bax. Bax gene expression was intensively increased with the despaired of bcl-X gene expression and significant decrease of bcl-2 gene expression in the cells treated with KRL. Thus, lectin induced apoptotic cell death in Ehrlich ascites carcinoma cells.

  2. Mode of Action Temu Kunci (Kaempferia pandurata Essential Oil on E. coli K1.1 Cell Determined by Leakage of Material Cell and Salt Tolerance Assays

    Directory of Open Access Journals (Sweden)

    MIKSUSANTI

    2008-06-01

    Full Text Available The essential oil of Kaempferia pandurata consist of terpen and oxygenated terpen that exhibits broad-spectrum antimicrobial activity. It’s mode of action against the gram-negative bacterium E. coli K1.1 has been investigated using a range of treatments. The mode action of the essential oil were analyzed by it’s ability to leakage E. coli K1.1 cell, to change permeability of the cell, and to alter salt tolerance of the cell. Ion leakage from the cell were analyzed by atomic absorption spectrophotometer. Salt tolerance assays was conducted by investigating the ability of E. coli K1.1 treated with temu kunci essential oil to grow on NA supplemented with NaCl. Protein and acid nucleic leakage were analyzed by UV spectrophotometer. There were inorganic compound leakage (potassium, calcium ion and organic compound leakage (nucleic acid, protein from cytoplasmic membrane, after exposing this organism to essential oil of Kaempferia pandurata. The more concentration of oil added, the more leakage was observed due to the loss of absorbing material such as nucleic acid (260 nm and protein (280 nm, the loss of potassium and calcium ion, and loss of the salt tolerance of E. coli K1.1.

  3. Protective effect of the methanolic extract of malva parviflora l. leaves on acetic acid-induced ulcerative colitis in rats

    Directory of Open Access Journals (Sweden)

    Aisha Dugani

    2016-01-01

    Full Text Available Background/Aims: Inflammatory bowel disease (IBD is a general term describing chronic, idiopathic relapsing, inflammatory conditions of the gastrointestinal tract of unknown etiology. Previous studies have indicated that Malva parviflora leaf extract possesses anti-inflammatory, antioxidant, and antiulcerogenic activity. activity. This work aimed to investigatee the anti-inflammatory effect of the methanolic (MEMP and aqueous (AEMP extracts of M. parviflora leaves on acetic acid-induced colitis in rats. Materials and Methods: 42 male Wistar albino rats were divided into seven groups (n = 6. Group I: Normal saline control group with no colitis; Group II: Acetic acid colitis group; Group III: 100 mg/kg/5 d MEMP; Group IV: 200 mg/kg/5 d.MEMP; Group V: 100 mg/kg/5 d AEMP; Group VI: 200 mg/kg/5 d AEMP; Group VII: Prednisolone group (2 mg/kg/5 d. Treatments were followed by induction of colitis using intrarectal instillation of 2 mL of 4% acetic acid. Colon damage was evaluated macroscopically (spleen weight/body weight, colon weight/length ratio and the histological changes were also recorded. Results: The results of this study showed that acetic acid caused severe inflammation of the colon and a significant increase in spleen weight/body weight, and an increase in colon weight/length ratio compared with normal control group. Pretreatment with MEMP and AEMP for 5 days followed by induction of colitis resulted in a significant attenuation of spleen weight and colon weight/length ratio compared with acetic acid control group. Methanolic extract provided better anticolitic effect than aqueous extract; the effect was prominent at the dose of 200 mg/kg. Histopathological findings confirmed the protective effect of the MEMP. Conclusion: In conclusion, MEMP could ameliorate mucosal damage in experimentally induced colitis when given orally.

  4. Antioxidant Activity of Ixora parviflora in a Cell/Cell-Free System and in UV-Exposed Human Fibroblasts

    Directory of Open Access Journals (Sweden)

    Hsiu-Mei Chiang

    2011-07-01

    Full Text Available Polyphenols and flavonoids possess a variety of biological activities including antioxidant and anti-tumor activities. Ixora parviflora is a member of the flavonoid-rich Rubiaceae family of flowering plants and used as folk medicine in India. The aim of this study was to investigate the antioxidant activity of Ixora parviflora extract (IPE in a cell-free system and erythrocytes, and the ability of IPE to inhibit reactive oxygen species (ROS generation in human fibroblasts (Hs68 after ultraviolet (UV exposure. Various in vitro antioxidant assays were employed in this study. The extraction yield of IPE was 17.4 ± 3.9%, the total phenolic content of IPE was 26.2 μg gallic acid equivalent (GAE/mg leaves dry weight and the total flavonoids content was 54.2 ± 4.4 μg quercetin equvalent (QE/mg extract. The content of chlorogenic acid was 9.7 ± 1.2 mg/g extract. IPE at 1000 μg/mL exhibited a reducing capacity of 90.5 ± 0.6%, a 1,1-diphenyl-2-picrylhydrazy (DPPH radical scavenging activity of 96.0 ± 0.4%, a ferrous chelating activity of 72.2 ± 3.5%, a hydroxyl radical scavenging activity of 96.8 ± 1.4%, and a hydrogen peroxide scavenging activity of 99.5 ± 3.3%. IPE at 500 μg/mL also possessed inhibitory activity against 2,2'-azobis (2-methylpropionamidine dihydrochloride (AAPH-induced hemolysis of erythrocytes (89.4 ± 1.8% and resulted in a 52.9% reduction in ROS generation in UV-exposed fibroblasts. According to our findings, IPE is a potent antioxidant and a potential anti-photoaging agent.

  5. Repellent and insecticidal effects of the essential oil of Kaempferia galanga rhizomes to Liposcelis bostrychophila (Psocoptera: Liposcelidae).

    Science.gov (United States)

    Liu, Xin Chao; Liang, Yan; Shi, Wang Peng; Liu, Qi Zhi; Zhou, Ligang; Liu, Zhi Long

    2014-08-01

    The aim of this research was to determine chemical composition and repellent and insecticidal activities of the essential oil of Kaempferia galanga L. rhizomes against the booklouse, Liposcelis bostrychophila Badonnel, and to isolate insecticidal or repellent constituents from the oil. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. Twenty-eight components of the oil were identified. The major compounds in the oil were ethyl-rho-methoxycinnamate (38.6%), ethyl cinnamate (23.2%), 1,8-cineole (11.5%), trans-cinnamaldehyde (5.3%), and borneol (5.2%). Based on bioactivity-guided fractionation, four active constituents were isolated from the oil and identified as 1,8-cineole, ethyl cinnamate, ethyl rho-methoxycinnamate, and trans-cinnamaldehyde. The essential oil exhibited contact toxicity against the booklouse with an LC50 value of 68.6 microg/cm2. Ethyl cinnamate (LC50 = 21.4 microg/cm2) exhibited stronger contact toxicity than ethyl rho-methoxycinnamate and trans-cinnamaldehyde (LC50 = 44.6 and 43.4 microg/cm2, respectively) while 1,8-cineole showed weak acute toxicity. The essential oil also possessed fumigant toxicity against the booklouse with a LC50 value of 1.5 mg/liter air. 1,8-Cineole and trans-cinnamaldehyde (LC50 = 1.1 and 1.3 mg/liter, respectively) possessed stronger fumigant toxicity against the booklouse than ethyl cinnamate and ethyl rho-methoxycinnamate (LC50 = 10.2 and 10.2 mg/liter air, respectively). trans-Cinnamaldehyde was strongly repellent to booklice, whereas ethyl cinnamate and ethyl rho-methoxycinnamate were weakly repellent and 1,8-cineole did not repel booklice. The results indicate that the essential oil and its constituent compounds have potential for development into natural insecticides or fumigants and repellents for control of insects in stored grains.

  6. Evaluation of yield, quality and antioxidant activity of essential oil of in vitro propagated Kaempferia galangaLinn

    Institute of Scientific and Technical Information of China (English)

    Suprava Sahoo; Reena Parida; Sikha Singh; Rabindra N Padhy; Sanghamitra Nayak

    2014-01-01

    Objective:To determine chemical constituents and antioxidant properties of essential oil from rhizome of the medicinal plant,Kaempferia galanga(K. galanga)Linn.(Zingiberaceae) in conventionally propagated(CP) andin vitro propagated(IVP) plants.Methods:In vitro(micro) propagation ofK. galanga was done by inoculating explants on toMurashige andSkoog agar medium, supplemented with suitable combinations of phytohormones; the regenerants were transferred to soil for further growth.Essential oil preparations of bothCP andIVP rhizomes grown in soil, obtained by the hydro-distillation method were analyzed by gas chromatography-mass spectrometry.Antioxidant activities of essential oil samples were monitored. Results:Maximum numbers of regenerated shoots were found in the medium supplemented with1 mg/L benzyl adenine and0.5 mg/L indole-3-acetic acid.A total of6 compounds were identified from rhizomes fromCP andIVP plants that yielded96.9% and97.81% of the total oil contents, respectively.The major compound of rhizome oil identified fromCP andIVP rhizomes was ethyl p-methoxy cinnamate in quantities,82.01% and71.77%, respectively, without any compositional variation.Antioxidant properties of essential oil preparations were assessed by the2,2-diphenyl-1-picrylhydrazyl(DPPH) and hydrogen peroxide radical scavenging assays.Moreover, antioxidant activities of rhizome-oil fromIVP plants were better than that ofCP oil samples.Conclusions:As IVP rhizomes had better oil yield, those could be used for a large scale commercial propagation for sustainable use of essential oil.The principal chemical in the essential oil, ethyl p-methoxy cinnamate could help apothecary, for several ailments.

  7. Activity of panduratin A isolated from Kaempferia pandurata Roxb. against multi-species oral biofilms in vitro.

    Science.gov (United States)

    Yanti; Rukayadi, Yaya; Lee, Kwan-Hyoung; Hwang, Jae-Kwan

    2009-03-01

    The formation of dental biofilm caused by oral bacteria on tooth surfaces is the primary step leading to oral diseases. This study was performed to investigate the preventive and reducing effects of panduratin A, isolated from Kaempferia pandurata Roxb., against multi-species oral biofilms consisting of Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus. Minimum inhibitory concentration (MIC) of panduratin A was determined by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution assay. Prevention of biofilm formation was performed on 96-well microtiter plates by coating panduratin A in mucin at 0.5-40 microg/ml, followed by biofilm formation at 37 degrees C for 24 h. The reducing effect on the preformed biofilm was tested by forming the biofilm at 37 degrees C for 24 h, followed by treatment with panduratin A at 0.2-10 microg/ml for up to 60 min. Panduratin A showed a MIC of 1 microg/ml for multi-species strains. Panduratin A at 2 x MIC for 8 h exhibited bactericidal activity against multi-species planktonic cells for 8 h. At 8 x MIC, panduratin A was able to prevent biofilm formation by > 50%. Biofilm mass was reduced by > 50% after exposure to panduratin A at 10 microg/ml for 15 min. Panduratin A showed a dose-dependent effect in preventing and reducing the biofilm. These results suggest that panduratin A is applicable as a natural anti-biofilm agent to eliminate oral bacterial colonization during early dental plaque formation.

  8. Evaluation, prediction and optimization the ultrasound-assisted extraction method using response surface methodology: antioxidant and biological properties of Stachys parviflora L.

    OpenAIRE

    2016-01-01

    Objective(s): To optimize the extraction method using response surface methodology, extract the phenolic compounds, and identify the antioxidant and biological properties of Stachys parviflora L. extracts. Materials and Methods: Maceration and ultrasound-assisted extraction (UAE) (4, 7, 10 min treatment time, 40, 70, 100 % high-intensity and 60, 80, 100 % (v v-1) methanol purity) were applied to obtain the extracts. SEM was conducted to provide the microstructure of the extracted plant. MICs ...

  9. Evaluation of the potential of Pontederia parviflora Alexander in the absorption of copper (Cu and its effects on tissues = Avaliação do potencial de pontederia parviflora Alexander na absorção de cobre (Cu e efeitos nos tecidos

    Directory of Open Access Journals (Sweden)

    Graziela Custodio Balassa

    2010-07-01

    Full Text Available The study sought to evaluate the potential of the aquatic macrophytePontederia parviflora Alexander in the absorption of copper (Cu and possible variations in its tissues after 21 days of exposure to this metal. The concentration of Cu was analyzed in the solution and in the vegetal tissues (stem, root and leaves. The experiment was set up in triplicates with weekly measurements of pH, temperature and DO. The results indicated that P. parviflora reduced 96% of Cu in the solution and the root was the vegetal tissue, which accumulated more Cu. Values of pH, DO and temperature were in accordance with the metabolic activities of the plants. In the anatomic analyses, dark spots were identified in the vascular bundles and in the epidermis of the aerial parts, highlighting the variation resulting from the presence of this substance. However, these variations were not sufficient to damage the development of the individuals. P. parviflora showed high capacity of extraction and storage of the metal, being a good alternative to aquatic environments with high concentrations of Cu. O estudo avaliou o potencial da macrófita aquática Pontederia parviflora Alexander na absorção de cobre (Cu e possíveis alterações nos tecidos, após 21 dias de exposição. O teor do metal foi analisado na solução e nos tecidos vegetais (caule, raiz e folhas. O experimento foi montado em triplicatas com medidas semanais dopH, temperatura e OD. Os resultados mostraram que P. parviflora reduziu 96% do Cu na solução e a porção vegetal que acumulou mais o metal foi a radicular. O pH, OD e temperatura apresentaram valores condizentes com as atividades metabólicas das plantas. Nas análises anatômicas, foram identificadas manchas escuras nos feixes vasculares e na epiderme das partes aéreas, evidenciando a alteração provocada pela presença da substância. No entanto essas alterações não foram suficientes para prejudicar o desenvolvimento dos indivíduos. P

  10. Efeito do fogo na produção de frutos de Qualea parviflora Mart. (Vochysiaceae em cerrado sensu stricto

    Directory of Open Access Journals (Sweden)

    Alexandre Cesar Palermo

    2012-08-01

    Full Text Available Entre os muitos efeitos causados por queimadas nas espécies arbóreas nativas do Cerrado, a alteração da produção de frutos tem destaque, pois implica diretamente na manutenção de populações locais. O objetivo deste trabalho foi investigar o efeito de uma queimada prescrita na produção de frutos de Qualea parviflora Mart. em área de Cerrado sensu stricto em Brasília, DF. Foram utilizadas duas áreas de Cerrado sensu stricto, uma submetida a regime de queima bienal em agosto (queimada e outra protegida contra a queima há 14 anos (controle. Em cada área, 10 indivíduos reprodutivos foram selecionados e a sua produção de botões florais, flores e frutos, acompanhada durante 22 meses. Dois meses após uma queimada prescrita em 26 de agosto de 2008, a produção de estruturas reprodutivas foi maior na área queimada do que na área-controle. Contudo, a proporção de botões que geram flores e frutos ("fruit set" foi a mesma nas duas áreas. Na estação reprodutiva seguinte, um ano após a queima não houve produção de inflorescências na área queimada. No entanto, na área-controle a produção de frutos foi maior do que no período anterior. A ausência de produção de flores nos indivíduos da área queimada um ano após o fogo sugere que Q. parviflora pode necessitar de mais de um ano para retornar ao seu ciclo normal de reprodução, indicando que os efeitos de médio e de longo prazo devem ser considerados ao se usar o fogo como instrumento de manejo para redução do combustível em áreas de Cerrado.

  11. Study on antioxidantive activity of extracts from Kaempferia galanga L.%山奈提取物抗氧化性能研究

    Institute of Scientific and Technical Information of China (English)

    王锐; 何嵋; 周云; 刘磊; 刘忠荣

    2011-01-01

    分别利用DPPH·法和碘量法测试山奈(Kaempferia galanga L.)提取物的抗氧化活性.结果表明,山奈 的乙酸乙酯提取物(EAK)和正丁醇提取物(BK)具有良好的抗氧化活性.在碘量法测试中,0.04%的EAK抗氧化作用最强,且超过0.02%的BHT;在对DPPH自由基清除试验中,BK的效果最好,清除DPPH自由基的EC50值为1.13 mg/mL,是BHT的61%.

  12. Identification and evaluation of counter-irritant potential of crude extract of Malva parviflora L. by WHO recommended methods.

    Science.gov (United States)

    Ishtiaq, Saiqa; Hassan, Syed Saeed-ul; Niaz, Uzma; Saeed, Muhammad Asif

    2012-07-01

    Plenty of medicinal plants are available in Pakistan and are in human use as herbal medicines from ancient time. Present work is based on the evaluation of the use of Malva parviflora in skin irritation problems. For this purpose, powdered plant material (The aerial part and roots separately) was extracted by using successive solvent extraction method using petroleum ether, chloroform and methanol. Resulting three crude fractions were subjected to counter-irritant investigations on rabbit's ear. Petroleum ether fraction exhibited prominent counter-irritant potential. Five compounds named, as MP-1, MP-2, MP-3, MP-4 and MP-5 were isolated from petroleum ether extract by column and thin layer chromatography. These compounds were subjected to UV spectrophotometer for detection of absorption of light, then FTIR for specific functional group identification and counter-irritant potentials was evaluated on rabbit's ear skin. The MP-1 and MP-2 exhibited excellent counter-irritant activity in different dilutions than others. However, dilution 100 μg/ml showed maximum activity.

  13. Volatile oil from striped African pepper (Xylopia parviflora, Annonaceae) possesses notable chemopreventive, anti-inflammatory and antimicrobial potential.

    Science.gov (United States)

    Woguem, Verlaine; Fogang, Hervet P D; Maggi, Filippo; Tapondjou, Léon A; Womeni, Hilaire M; Quassinti, Luana; Bramucci, Massimo; Vitali, Luca A; Petrelli, Dezemona; Lupidi, Giulio; Papa, Fabrizio; Vittori, Sauro; Barboni, Luciano

    2014-04-15

    Fruits of Xylopia parviflora, well known as striped African pepper, are sold in the Cameroonian markets as a flavouring ingredient to make traditional soups. The essential oil hydrodistilled from fruits was analysed for in vitro biological activities, namely cytotoxic, anti-inflammatory, antimicrobial and antioxidant, by MTT, nitric oxide inhibitory assay, agar disc diffusion method, and DPPH and ABTS assays. The essential oil composition, analysed by GC and GC-MS, was dominated by monoterpene hydrocarbons (50.0%) responsible for the pepper odour, such as β-pinene (34.0%) and α-pinene (10.3%). The oil induced a strong inhibitory effect on tumour cells MDA-MB 231 and HCT116, with inhibition values close to those of cisplatin. A dose-dependent decrease in NO production was noted in RAW 264.7 macrophages treated with the oil, revealing a promising anti-inflammatory potential. The essential oil showed a measurable antimicrobial activity against all the species tested, while the radical scavenging activity was low.

  14. Variation in antibacterial and anti-inflammatory activity of different growth forms of Malva parviflora and evidence for synergism of the anti-inflammatory compounds.

    Science.gov (United States)

    Shale, T L; Stirk, W A; van Staden, J

    2005-01-01

    Malva parviflora leaves and roots were collected from five sites within the Qacha's Nek District in Lesotho. These plants had two distinct growth forms--upright and prostrate. Hexane, methanol and water extracts were made from the plant material and tested for antibacterial and anti-inflammatory activity using the disc diffusion and cyclooxygenase-1 (Cox-1) bioassays, respectively. Hexane, methanol and water extracts made from Malva parviflora with a prostrate growth form inhibited the growth of Gram-positive and Gram-negative bacteria, while extracts made from plants with an upright growth form inhibited the growth of Gram-positive bacteria only. Cox-1 anti-inflammatory activity of hexane, methanol and water extracts did not show any variation between the two growth forms. The hexane extracts of both the leaves and roots were the most inhibitory. The water extracts had the least inhibitory activity. Bioassay-guided fractionation of the root dichloromethane extract showed that Cox-1 anti-inflammatory activity was caused by at least two compounds that acted synergistically to produce the biological effect.

  15. Caracterización fisicoquímica del aceite crudo y refinado de la semilla de Proboscidea parviflora (Uña de gato

    Directory of Open Access Journals (Sweden)

    Vázquez Moreno, L.

    1993-02-01

    Full Text Available Searching for seeds as new sources of oleaginous that can cover the national needs, it was studied the oil of Proboscidea parviflora. This oil was extracted from the seed with hexane in a Soxhlet apparatus, and its physical and chemical properties were determined, as well as the fatty acid composition by gas chromatography, in crude and refined oil. After a simple refining and deodorization process, the extracted oil had good quality with a high percentage of insatured fatty acids.En la búsqueda de semillas que sirvan como nuevas fuentes de oleaginosas para cubrir las necesidades existentes a nivel nacional, se estudió el aceite de Proboscidea parviflora. El aceite se extrajo de la semilla con hexano en un aparato Soxhlet. Se le determinaron sus propiedades físicas y químicas, así como el perfil de ácidos grasos por cromatografía de gases, tanto del aceite crudo como del refinado. Después de un proceso sencillo de refinación y desodorización, el aceite resultó ser de buena calidad con un grado de insaturación relativamente alto.

  16. 广东阳春双滘原产地产品沙姜的特征元素%Characteristic Elements ofKaempferia Galanga L. from Yangchun in Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    刘慧; 常向阳; 付善明; 陈南; 赵晓峰; 张红英

    2011-01-01

    植物特征元素及其组合能一定程度上反映特定区域对该地植被生长产生的影响.为了探讨元素及其组合能否作为原产地产品的元素指纹标记,分析了广东阳春双滘地区沙姜与土壤中十多种元素的含量、相关性及元素吸收系数.该研究中微量元素在沙姜和土壤中均具有较好的传承性;沙姜对各种元素的吸收具有差异性,沙姜与土壤中元素也具有一定的相关性;通过权重分析初步认定该区域沙姜特征元素为Mn、Zn、Mg、Sr、Cu、Ni、Fe.区域地球化学背景对原产地产品的影响值得深入探讨.%The characteristic elements and their assembly of plant can indicate the effect of special geochemical environment on the local plant. In this paper fourteen trace elements in soil and Kaempferia Galangal L samples were measured to explore the feasibility of characteristic elements as the fingerprinting marker of products of origin in Shuangjiao of Yangchun region. The results showed that: there was a significant correlation between the contents of trace elements in soil and in plant; the absorptive capacities ofKaempferia Galangal L. to trace elements were different; Mg Mn, Zn, Sb, Fo, Cu and Sr were the characteristic elements of Kaempferia Galangal L. by weight analysis. Effect of regional geochemical background on the products of origin should be further explored.

  17. Evaluation, prediction and optimization the ultrasound-assisted extraction method using response surface methodology: antioxidant and biological properties of Stachys parviflora L.

    Directory of Open Access Journals (Sweden)

    Davoud Salarbashi

    2016-05-01

    Full Text Available Objective(s:To optimize the extraction method using response surface methodology, extract the phenolic compounds, and identify the antioxidant and biological properties of Stachys parviflora L.  extracts. Materials and Methods: Maceration and ultrasound-assisted extraction (UAE (4, 7, 10 min treatment time, 40, 70, 100 % high-intensity and 60, 80, 100 % (v v-1 methanol purity were applied to obtain the extracts. SEM was conducted to provide the microstructure of the extracted plant. MICs (colorimetric assay, MFCs (colony diameter, total phenolic content, total flavonoid content, radical scavenging capacity and extraction efficiency were determined. HPLC analysis was applied to measure the existent phenolic compounds. Results: A quadratic model (4 min treatment time, 74.5 % high-intensity and 74.2 % solvent purity was suggested as the best (TPC: 20.89 mg GAE g-1 d.m., TFC: 6.22 mg QEs g-1 d.m., DPPH IC50: 21.86 µg ml-1 and EE: 113.65 mg g-1 d.m. UAE extraction model. The optimized UAE extract was generally more effective against Gram-positive microorganisms (MIC: 10-20; MBC: 10-40 (mg ml-1 than Gram-negative ones (MIC: 40; MBC: >40 (mg ml-1. Moreover, it (MGI: 2.32-100 % revealed more anti-mold activity than maceration (MGI: Conclusion: RSM optimization was successfully applied for UAE from S. parviflora. The considerable antioxidant and biological properties were attributed to the phenolic compounds.

  18. HPLC法测定山柰药材中山柰素的含量%Content Determination of Kaempferol in Kaempferia galanga by HPLC

    Institute of Scientific and Technical Information of China (English)

    李刚; 封传华; 张静; 徐兰; 陶晓璇

    2016-01-01

    目的:建立测定山柰药材中山柰素含量的方法。方法:采用高效液相色谱法。色谱柱为Diamonsil ODS2 C18,流动相为甲醇-0.4%磷酸溶液,流速为1 ml/min,检测波长为367 nm,柱温为30℃,进样量为10μl。结果:山柰素的检测质量浓度线性范围为0.00158~0.158 mg/ml;精密度、稳定性、重复性试验的RSD<3%;加样回收率为95.52%~99.32%,RSD=1.47%(n=6)。结论:该方法操作简单、结果准确、重复性较好,可用于山柰药材中山柰素的含量测定。%OBJECTIVE:To establish a method for the content determination of kaempferol in Kaempferia galanga. METH-ODS:HPLC was performed on the column of Diamonsil ODS2 C18 with mobile phase of methanol-0.4% Phosphoric acid solution at a flow rate of 1 ml/min,detection wavelength was 367 nm,column temperature was 30℃,and injection volume was 10 μl. RE-SULTS:The linear range of kaempferol was 0.001 58-0.158 mg/ml;RSDs of precision,stability and reproducibility tests were low-er than 3%;recovery was 95.52%-99.32%(RSD=1.47%,n=6). CONCLUSIONS:The method is simple,accurate and reproduc-ible,and can be used for the content determination of kaempferol in K. galanga.

  19. 海南三七(姜科)的食源性欺骗传粉%Food-deceptive pollination in Kaempferia rotunda ( Zingiberaceae)

    Institute of Scientific and Technical Information of China (English)

    路国辉; 李新亮; 武文华; 刘宗莉; 王英强

    2012-01-01

    Most animal pollinated plants for the success of reproduction have evolved a variety of floral morphological characters to attract pollinators, such as providing nectar, pollen, brood sites for the pollinators. However, non-rewarding flowers by deceptive pollination are found in 146 genera from 33 angiosperm families. These deceptive pollination patterns mainly appear in highly evolved orchid family which is renowned for its enormous diversity of pollination mechanisms. Recently,many kinds of pollination mechanisms and breeding systems were found in Zingiberaceae, such as delayed selfing mechanism,flexistyly and self-pollination by sliding pollen. Here a food-deceptive pollination mechanism in Kaempferia rotunda which was a new addition to the pollination systems in Zingiberaceae was reported. The pollination biology of K. rotunda was investigated in Nonghua,Guangxi Province in 2006 and South China Normal University Botanical Garden in 2007. The brilliant purple flowers open in the morning at about 5:30 - 6:00 and wither at 17:00 -18:00, lasting for about 11 -12 h. During an thesis, both pollen viability and stigma receptivity remained at a high level(>90%). The mean P/0 ratio was 82. 20±47. 89(n = 20). Our observations showed that carpenter bee(Xylocopa sp. )was the main pollinator, and visits flowers only for nectar. However, the flowers produce no nectar. We speculated that K. rotunda exploited food deceptive mechanism to attract pollinators. Breeding system experiments showed that there was rare fruit set in Nonghua population of K. rotunda, which indicated K. rotunda might abandon sexual reproduction for some form of clonal reproduction.%有花植物为繁殖成功,进化出各种各样的花部特征来吸引传粉者,如为传粉者提供花蜜、花粉、栖息地等,然而在33科146属的被子植物中也存在着不提供任何报酬而欺骗昆虫为其传粉的现象.这种欺骗性传粉模式主要出现在高度进化的具有多样化传粉模

  20. Relaxant mechanisms of 3, 5, 7, 30, 40-pentamethoxyflavone on isolated human cavernosum

    DEFF Research Database (Denmark)

    Jansakul, Chaweewan; Tachanaparuksa, Kuldej; Mulvany, Michael J.

    2012-01-01

    We have investigated effects and mechanisms responsible for the activity of 3, 5, 7, 30, 40-pentamethoxyflavone (PMF) on isolated human cavernosum. PMF is the major flavone isolated from Kaempferia parviflora claimed to act as an aphrodisiac. PMF caused relaxation of phenylephrine precontracted h...

  1. Effects of Applying Accumulator Straw in Soil on Growth and Cadmium Accumulation of Galinsoga parviflora%土施富集植物秸秆对牛膝菊生长及镉积累的影响

    Institute of Scientific and Technical Information of China (English)

    汤福义; 林立金; 廖进秋; 廖明安; 何静; 杨代宇; 张潇

    2015-01-01

    To study the allelopathy effects of accumulator straw on hyperaccumulator,a pot experiment was con-ducted to study the effects of applying accumulators (Conyza canadensis,Cardamine hirsuta,Eclipta prostrata and Nasturtium officinale)straws in soil on growth and cadmium accumulation of Galinsoga parviflora under cadmium pollution.The results were as follows:Compared with non-application (control),the application of C.canadensis and C.hirsute straws improved the roots,stems,leaves,shoots and whole plants biomasses of G.parviflora,and the plant height and antioxidant enzymes (SOD,POD and CAT)activity of G.parviflora also increased.The straws of E.pros-trate and N.officinale reduced the biomass,plant height and antioxidant enzyme activity of G.parviflora.The straws of C.canadensis,C.hirsuta,E.prostrata and N.officinale improved cadmium content in shoots of G.parviflora,which improved 1 2.01 %,9.55%,22.03% and 5.39% respectively compared with control,but only C.canadensis and C.hirsuta straws improved the cadmium accumulation in shoots of G.parviflora (which improved by 35.78% and 1 1 .77% respectively compared with control).C.canadensis and C.hirsuta straws increased soil catalase activity, soil urease activity and soil invertase activity,and the straws of E.prostrata and N.officinale reduced soil activity. Therefore,the applying C.canadensis and C.hirsuta straws in soil could improve cadmium contaminated soil remedy ability of G.parviflora,and C.canadensis straw was the best one.%为研究富集植物秸秆对超富集植物的化感作用,通过盆栽试验,研究了镉污染条件下,土施4种镉富集植物(小飞蓬、碎米荠、旱莲草和豆瓣菜)秸秆对牛膝菊生长及镉积累的影响。结果表明:与未施用相比,施用小飞蓬和碎米荠秸秆提高了牛膝菊根系、茎秆、叶片、地上部分及整株生物量,也提高了牛膝菊株高和抗氧化酶(SOD、POD 和CAT)活性,但施用旱莲草和豆瓣菜秸秆

  2. Efeito do espaçamento no desenvolvimento de Poecilanthe parviflora Benth (coração-de-negro aos 42 anos, em Bauru, SP. Effect of the spacing in the development of Poecilanthe parviflora Benth. (coração-de-negro of 42 year-old grown, in Bauru, SP.

    Directory of Open Access Journals (Sweden)

    Israel Luiz de LIMA

    2010-06-01

    Full Text Available No Brasil, plantios de espécies nativas visando à exploração comercial são raros, devido ao crescimento lento e à falta de informações silviculturais e oferta de sementes e mudas de boa qualidade. Dessa forma, no ano de 1964 foi implantado umexperimento visando avaliar os efeitos do espaçamento no desenvolvimento de Poecilanthae parviflora, que é uma espécie de crescimento lento, na Estação Ecológica de Bauru, SP. O delineamento experimental utilizado foi em blocos ao acaso, comcinco tratamentos e cinco repetições. Os tratamentos constituíram-se dos seguintes espaçamentos: 1,0 m x 1,0 m; 1,5 m x 1,5 m; 2,0 m x 2,0 m; 2,5 m x 2,5 m e 3,0 m x 3,0 m, tendo sido avaliados o diâmetro à altura do peito, altura total, volume individual, volume por hectare e a sobrevivência. Os resultados demonstraram que os espaçamentos não influenciaram asobrevivência, mas produziram efeitos no diâmetro à altura do peito, altura total, volume individual e volume por hectare. Com o aumento do espaçamento, houvemaior incremento nos valores das três primeiras variáveis, ocorrendo o inverso na última. Possivelmente, o uso de espaçamentos iniciais mais adensados e o emprego de desbastes seletivos e sucessivos resultariamemmaior proporção de madeira e melhor qualidade.In Brazil, planting of native species aiming at the commercial exploration is rare, due to the slow growth, the lack of silvicultural information and supply of seeds and seedling of superior quality. On account of this, in 1964 an experiment aiming to evaluate the effects of planting spacings on growing of Poecilanthae parviflora, which is a species of slow growth, was implanted in the Ecological Station of Bauru, SP. The trial was established in a complete-randomized block-design, with five treatments and five repetitions. The treatments consisted of the following spacings: 1.0 m x 1.0 m; 1.5 m x 1.5 m; 2.0 m x 2.0 m; 2.5 m x 2.5 m and 3.0 m x 3.0 m, which were evaluated at

  3. Anti-allergic activity of some selected plants in the Zingiberaceae family.

    Science.gov (United States)

    Tewtrakul, Supinya; Subhadhirasakul, Sanan

    2007-02-12

    Ethanolic and water extracts, together with volatile oils from the rhizomes of six selected Zingiberaceous plants, including Curcuma mangga, Kaempferia galanga, Kaempferia parviflora, Zingiber cassumunar, Zingiber officinale and Zingiber zerumbet were investigated for their anti-allergic activities using a RBL-2H3 cell line. The ethanolic (EtOH) extract of Kaempferia parviflora exhibited the most potent anti-allergic effect against antigen-induced beta-hexosaminidase release as a marker of degranulation in RBL-2H3 cells, with an IC(50) value of 10.9 microg/ml, followed by Zingiber cassumunar (EtOH, IC(50)=12.9 microg/ml) and Curcuma mangga (water, IC(50)=36.1 microg/ml). The volatile oils of these six plants were apparently inactive (IC(50)>100 microg/ml). The crude extracts were also tested on beta-hexosaminidase activity to clarify whether their effects were due to the inhibition of enzyme activity or of degranulation. As a result, the plant extracts were inactive against the enzyme activity of beta-hexosaminidase. These findings support the use in Thai traditional medicine of these selected Zingiberaceous plants, especially Kaempferia parviflora and Zingiber cassumunar, for treatment of allergy and allergic-related diseases.

  4. Temperature dependence of violaxanthin de-epoxidation and non-photochemical fluorescence quenching in intact leaves of Gossypium hirsutum L. and Malva parviflora L.

    Science.gov (United States)

    Bilger, W; Björkman, O

    1991-05-01

    The temperature dependence of the rate of de-epoxidation of violaxanthin to zeaxanthin was determined in leaves of chilling-sensitive Gossypium hirsutum L. (cotton) and chilling-resistant Malva parviflora L. by measurements of the increase in absorbance at 505 nm (ΔA 505) and in the contents of antheraxanthin and zeaxanthin that occur upon exposure of predarkened leaves to excessive light. A linear relationship between ΔA 505 and the decrease in the epoxidation state of the xanthophyll-cycle pigment pool was obtained over the range 10-40° C. The maximal rate of de-epoxidation was strongly temperature dependent; Q10 measured around the temperature at which the leaf had developed was 2.1-2.3 in both species. In field-grown Malva the rate of de-epoxidation at any given measurement temperature was two to three times higher in leaves developed at a relatively low temperature in the early spring than in those developed in summer. Q10 measured around 15° C was in the range 2.2-2.6 in both kinds of Malva leaves, whereas it was as high as 4.6 in cotton leaves developed at a daytime temperature of 30° C. Whereas the maximum (initial) rate of de-epoxidation showed a strong decrease with decreased temperature the degree of de-epoxidation reached in cotton leaves after a 1-2 · h exposure to a constant photon flux density increased with decreased temperature as the rate of photosynthesis decrease. The zeaxanthin content rose from 2 mmol · (mol chlorophyll)(-1) at 30° C to 61 mmol · (mol Chl)(-1) at 10° C, corresponding to a de-epoxidation of 70% of the violaxanthin pool at 10° C. The degree of de-epoxidation at each temperature was clearly related to the amount of excessive light present at that temperature. The relationship between non-photochemical quenching of chlorophyll fluorescence and zeaxanthin formation at different temperatures was determined for both untreated control leaves and for leaves in which zeaxanthin formation was prevented by dithiothreitol

  5. Caffeoylquinic acid derivatives from Bidens parviflora and their antihistamine release activites%小花鬼针草中咖啡酰奎宁酸类成分及其抑制组胺释放活性

    Institute of Scientific and Technical Information of China (English)

    王珏; 王乃利; 姚新生; 北中進

    2006-01-01

    目的研究小花鬼针草Bidens parviflora全株的化学成分,并通过抑制组胺释放活性方法寻找生物活性化合物.方法采用硅胶、Sephadex LH-20和ODS柱色谱分离化合物,运用1D NMR,2D NMR等波谱法鉴定了化学结构,通过组胺抑制实验探讨抗炎活性.结果分离鉴定6种咖啡酰奎宁酸类化合物及其甲酯,分别是3,5-二氧咖啡酰奎宁酸(3,5-di-O-caffeoylquinic acid,Ⅰ)、3,4-二氧咖啡酰奎宁酸(3,4-di-O-caffeoylquinic acid,Ⅱ)、4,5-二氧咖啡酰奎宁酸(4,5-di-O-caffeoylquinic acid,Ⅲ)、4-氧-咖啡酰奎宁酸(4-O-caffeoylquinic acid,Ⅳ)、5-氧-咖啡酰奎宁酸(5-O-caffeoylquinic acid,Ⅴ)、4-[3-(3,4-二羟基苯基)-丙烯酰氧基]-2,3-二羟基-2-甲基-丁酸{4-[3-(3,4-dihydroxy-phenyl)-acryloyloxy]-2,3-dihydroxy-2-methyl-butyric acid,Ⅵ}.结论所有化合物均为首次从该植物中分得,化合物Ⅵ为新化合物.这些化合物显示一定的抑制组织胺释放活性.%Objective Based on the activities of antihistamine release to study the compounds from Bidens parvi-flora and find biological active compounds. Methods The chemical constituents from B.parviflora were isolated by silica gel and Sphadex LH-20 column chromatographies and purified by preparative HPLC. The chemical structures had been identified by physiochemical properties and spectroscopic methods. Results Six caffeoylquinic acid derivatives were identified as 3, 5-di-O-caffeoylquinic acid ( Ⅰ ),3, 4-di-O-caffeoylquinic acid ( Ⅱ ), 4, 5-di-O-caffeoylquinic acid ( Ⅲ ), 4-O-caffeoylquinic acid ( Ⅳ ), 5-O-caffeoylquinic acid ( Ⅴ ), 4-[3-(3, 4-dihydroxy-phenyl)-acryloyloxy]-2, 3-dihydroxy-2-methyl-butyric acid ( Ⅵ ). Conclusion Compounds Ⅰ - Ⅵ are first obtained from B. parviflora and Ⅵ is new one. Some of the compounds exhibit the activities in antiallergic assays. Moreover, the structure-activity relationships of these compounds have been also discussed in this paper.

  6. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  7. Study on Megasporogenesis, Microsporogenesis and Development of Female and Male Gametophytes in Galinsona parviflora Car.%牛膝菊大、小孢子发生和雌、雄配子体的发育

    Institute of Scientific and Technical Information of China (English)

    胡铁锋

    2012-01-01

    通过石蜡切片技术对牛膝菊大小孢子发生和雌雄配子体发育过程进行研究,结果表明,牛膝菊花药4室,花药壁发育为简化型。由表皮、药室内壁和绒毡层组成。绒毡层于小孢子四分体时期开始变形,其细胞原生质体向药室中移动为变形绒毡层。小孢子孢原为多细胞,小孢子母细胞减数分裂产生四面体型的小孢子四分体。四分体胞质分裂为连续型,偶见同时型。成熟花粉2-细胞型。子房1室,每室1个倒生胚珠,具单珠被,薄珠心。大孢子母细胞减数分裂形成的4个大孢子呈直线形排列,其中合点端的大孢子为功能大孢子,蓼型胚囊。%This paper studies the megasporogensis,microsporogenisis and development of female and male ga- metophyte by paraffin wax of the meiosis of megaspore and microspore mother cells and the developmental processes of Galinsona parviflora Cav. 1 The results indicates that the anther has four chambers. The develop- ment of anther wall is primitive type which is composed of epidermis, endothecium and amoeboid tapetum. The tapetum begins to vary at the stage of tetrad with the cytoplasm moving into the anther cell. The cytokinesis of microspore mother cell in meiosis is simultaneous and continuous, and the tetrad are tetrahedral. The mature pollen grain is 2-celled. The ovary has 1 locule and there is l anatropous ovule in each locule. The ovule is unitegmic and tenuinucellatae. The megaspore mother cells are developed cal cell which undergoes meitotic division and forms a linear tetrad. The directly by a hypodermal archcspori- embryo sac is of Polygonum type.

  8. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    In the fields of power conversion devices and broadcasting/communication amplifiers, high power, high frequency and low losses are desirable. Further, for electronic elements in aerospace/aeronautical/geothermal surveys, etc., heat resistance to 500degC is required. Devices which respond to such hard specifications are called hard electronic devices. However, with Si which is at the core of the present electronics, the specifications cannot fully be fulfilled because of the restrictions arising from physical values. Accordingly, taking up new device materials/structures necessary to construct hard electronics, technologies to develop these to a level of IC were examined and studied. They are a technology to make devices/IC of new semiconductors such as SiC, diamond, etc. which can handle higher temperature, higher power and higher frequency than Si and also is possible of reducing losses, a technology to make devices of hard semiconducter materials such as a vacuum microelectronics technology using ultra-micro/high-luminance electronic emitter using negative electron affinity which diamond, etc. have, a technology to make devices of oxides which have various electric properties, etc. 321 refs., 194 figs., 8 tabs.

  9. Electronic Cigarettes

    Science.gov (United States)

    ... New FDA Regulations Text Size: A A A Electronic Cigarettes Electronic cigarettes (e-cigarettes) are battery operated products designed ... more about: The latest news and events about electronic cigarettes on this FDA page Electronic cigarette basics ...

  10. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  11. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  12. Ambient Electronics

    Science.gov (United States)

    Sekitani, Tsuyoshi; Someya, Takao

    2012-10-01

    We report the recent research progress and future prospects of flexible and printed electronics, focusing on molecular electronic material-based thin-film transistors, which are expected to usher in a new era of electronics.

  13. Electron cooling

    Science.gov (United States)

    Meshkov, I.; Sidorin, A.

    2004-10-01

    The brief review of the most significant and interesting achievements in electron cooling method, which took place during last two years, is presented. The description of the electron cooling facilities-storage rings and traps being in operation or under development-is given. The applications of the electron cooling method are considered. The following modern fields of the method development are discussed: crystalline beam formation, expansion into middle and high energy electron cooling (the Fermilab Recycler Electron Cooler, the BNL cooler-recuperator, cooling with circulating electron beam, the GSI project), electron cooling in traps, antihydrogen generation, electron cooling of positrons (the LEPTA project).

  14. Electron Microscopy.

    Science.gov (United States)

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  15. Electron Microscopy.

    Science.gov (United States)

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  16. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  17. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  18. Electronic Prescribing

    Science.gov (United States)

    ... Do you prescribe electronically?” For more information about electronic prescribing, call 1-800-MEDICARE (1-800-633- ... TTY users should call 1-877-486-2048 . Electronic eRx Prescribing I went to the pharmacy, and ...

  19. Basic electronics

    CERN Document Server

    Holbrook, Harold D

    1971-01-01

    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  20. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

    2015-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information P

  1. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  2. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  3. Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Slavko Đerić

    2016-12-01

    Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

  4. Chlorophyll Fluorescence Characteristics of Elaeagnus angustifolia L. And Grewia biloba G. Don var. Parviflora (Bge.)Hand.-Mazz. Seedlings under Drought Stress%干旱胁迫下沙枣和孩儿拳头叶绿素荧光特性研究

    Institute of Scientific and Technical Information of China (English)

    孙景宽; 张文辉; 陆兆华; 刘新成

    2009-01-01

    以沙枣和孩儿拳头2年生盆栽苗为材料,采用称重控水的方法设置对照(土壤含水量为25.6%~27.2%),轻度胁迫(19.2%~20.8%),中度胁迫(12.8%~14.4%),重度胁迫(6.4%~8.0%)4个梯度,研究了干旱胁迫对沙枣和孩儿拳头色素含量和叶绿素荧光特性的影响.结果表明:(1)随着干旱胁迫的加剧,两物种叶绿素a含量,叶绿素a/b比值,总叶绿素含量呈下降趋势,且叶绿素a对干旱胁迫的反应较叶绿素b敏感,但两物种叶绿素b含量和胡萝卜素含量变化规律不一致.(2)随着干旱胁迫的加剧,孩儿拳头F_m、F_v呈下降趋势,沙枣相反,但两物种F_0呈增加趋势,F_v/F_0、F_v/F_m呈下降趋势,F_v/F_m差异不显著;PhiPS2、ETR、qP先升高后降低,NPQ则先降低后升高.(3)虽然两物种表现出较强的抗旱性,但在重度干旱胁迫下(6.4%、~8.0%),光合色素含量、叶绿素荧光参数受到较大影响,推测此时的土壤水分含量为两物种光合色素、光系统Ⅱ的耐受极限;物种间相比,孩儿拳头更为敏感,在今后的园林管护中,要根据土壤水分状况和物种间的差异做好园林灌溉.%Elaeagnus angustifolia L. and Grewia biloba v ar. parviflora( Bge. ) Hand. -Mazz. 2-year-old seedlings as materials, using weighing method to set up control ( soil moisture 25. 6 % ~27. 2 % ) , light stress (19. 2 %~ 20. 8% ) , moderate stress (12.8%~14.4%), severe stress (6. 4% ~ 8. 0% ) , the effects of drought stress on pigment content and Chlorophyll fluorescence characteristics of E. angustifolia L. and G. biloba G. Don var. parv-iflora( Bge. )Hand. -Mazz. seedlings were studied. The results showed; ( 1 ) Along with the increasing degree of drought stress, the content of chlorophyll a, value of chlorophyll a/b, content of total chlorophyll of two species decreased, and the response of chlorophyll a to drought stress more is sensitive than chlorophyll b, but content of chlorophyll b and content of carotinoid of

  5. Micropower electronics

    CERN Document Server

    Keonjian, Edward

    1964-01-01

    Micropower Electronics deals with the operation of modern electronic equipment at micropower levels and the problems associated with micropower electronics. Topics covered include the relations between minimum required power density and frequency response for semiconductor triode amplifiers; physical realization of digital logic circuits; micropower microelectronic subsystems; and metal-oxide-semiconductor field-effect devices for micropower logic circuitry. This book is comprised of 10 chapters and begins with an analysis of fundamental relationships and basic requirements pertinent to the ph

  6. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  7. Paper electronics.

    Science.gov (United States)

    Tobjörk, Daniel; Österbacka, Ronald

    2011-05-03

    Paper is ubiquitous in everyday life and a truly low-cost substrate. The use of paper substrates could be extended even further, if electronic applications would be applied next to or below the printed graphics. However, applying electronics on paper is challenging. The paper surface is not only very rough compared to plastics, but is also porous. While this is detrimental for most electronic devices manufactured directly onto paper substrates, there are also approaches that are compatible with the rough and absorptive paper surface. In this review, recent advances and possibilities of these approaches are evaluated and the limitations of paper electronics are discussed.

  8. Electron holography

    CERN Document Server

    Tonomura, Akira

    1993-01-01

    Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text

  9. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  10. Electronic Photography

    Science.gov (United States)

    Payne, Meredith Lindsay

    1995-01-01

    The main objective was to assist in the production of electronic images in the Electronic Photography Lab (EPL). The EPL is a new facility serving the electronic photographic needs of the Langley community. The purpose of the Electronic Photography lab is to provide Langley with access to digital imaging technology. Although the EPL has been in operation for less than one year, almost 1,000 images have been produced. The decision to establish the lab was made after careful determination of the centers needs for electronic photography. The LaRC community requires electronic photography for the production of electronic printing, Web sites, desktop publications, and its increased enhancement capabilities. In addition to general use, other considerations went into the planning of the EPL. For example, electronic photography is much less of a burden on the environment compared to conventional photography. Also, the possibilities of an on-line database and retrieval system could make locating past work more efficient. Finally, information in an electronic image is quantified, making measurements and calculations easier for the researcher.

  11. Electron Bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, John W.; Miller, Anne-Frances; Jones, Anne K.; King, Paul W.; Adams, Michael W. W.

    2016-04-01

    Electron bifurcation is the recently recognized third mechanism of biological energy conservation. It simultaneously couples exergonic and endergonic oxidation-reduction reactions to circumvent thermodynamic barriers and minimize free energy loss. Little is known about the details of how electron bifurcating enzymes function, but specifics are beginning to emerge for several bifurcating enzymes. To date, those characterized contain a collection of redox cofactors including flavins and iron-sulfur clusters. Here we discuss the current understanding of bifurcating enzymes and the mechanistic features required to reversibly partition multiple electrons from a single redox site into exergonic and endergonic electron transfer paths.

  12. 芳香植物广陈皮和山奈中有翅桃蚜驱避物质的化学鉴定%Chemical Analysis of Active Volatile Components in Two Aroma Plants,Citrus chachiensis and Kaempferia galanga,Responsible for Repelling Alate Myzus persicae (Sulzer)

    Institute of Scientific and Technical Information of China (English)

    李为争; 庄丽; 付国需; 杨雷; 李慧玲; 原国辉

    2012-01-01

    Two aroma plants,Citrus chachiensis kneel and Kaempferia galanga root,were previously shown to repel alate Myzus persicae ( Sulzer). In this paper, the active components were identified via Soxlet extraction, condensation, column chromatography, and gas chromatography-mass spectrometry (GC-MS). Both Soxlet extracts retained the repellent effectiveness of their corresponding origins, but bioassay of the sequential binary combinations indicates that C. chachiensis extract and K. galangal extract exhibited additive or weak antagonistic interaction. The Soxlet extracts were subjected to bioassay-guided column chromatography using petroleum ether and diethyl ether as solvent system, totally 11 fractions were collected from each extract. Among C. chachiensis fractions,only one fraction (rinsed with 3: 7 volume ratio of petroleum ether and diethyl ether) showed extremely significant repellence;among K. galangal fractions,the one rinsed by equal volume of petroleum ether and diethyl ether showied the strongest repellence, whose repellent percentage reached to 45.56% ,and the 7:3 and 2:8 fractions also showed relatively low activity. GC-MS analysis indicates that the major volatile of C. chachiensis active fraction was D-limonene (39.07% ) ,and that of K. galangal were trans ethyl p-methoxy cinnamate (70.22% ) and cis ethyl p-methoxy cinnamate (19. 55% ), further bioassay confirmed the activities of D-limonene and trans ethyl p-methoxy cinnamate, and the two compounds also exhibited additive interaction as their origins.%芳香植物广陈皮和山奈的挥发物对有翅桃蚜具有较强的驱避作用,本试验采用提取、浓缩、柱层析和GC-MS等技术鉴定了其中的活性成分.生物测定结果表明,索氏提取法能够保留原始材料的驱避效果,且广陈皮和山奈的索氏提取物存在加成效应或微弱的拮抗效应.分别采用梯度混合的石油醚-乙醚混合淋洗剂对两种材料的索氏提取物进行柱

  13. Printed Electronics

    Science.gov (United States)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2016-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  14. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  15. Electronic diagrams

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Diagrams is a ready reference and general guide to systems and circuit planning and in the preparation of diagrams for both newcomers and the more experienced. This book presents guidelines and logical procedures that the reader can follow and then be equipped to tackle large complex diagrams by recognition of characteristic 'building blocks' or 'black boxes'. The goal is to break down many of the barriers that often seem to deter students and laymen in learning the art of electronics, especially when they take up electronics as a spare time occupation. This text is comprised of nin

  16. Digital electronics

    CERN Document Server

    Morris, John

    2013-01-01

    An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th

  17. Electronic identity

    CERN Document Server

    de Andrade, Norberto Nuno Gomes; Argles, David

    2014-01-01

    With the increasing availability of electronic services, security and a reliable means by which identity is verified is essential.Written by Norberto Andrade the first chapter of this book provides an overview of the main legal and regulatory aspects regarding electronic identity in Europe and assesses the importance of electronic identity for administration (public), business (private) and, above all, citizens. It also highlights the role of eID as a key enabler of the economy.In the second chapter Lisha Chen-Wilson, David Argles, Michele Schiano di Zenise and Gary Wills discuss the user-cent

  18. Stretchable electronics

    CERN Document Server

    Someya, Takao

    2012-01-01

    With its comprehensive coverage this handbook and ready reference brings together some of the most outstanding scientists in the field to lay down the undisputed knowledge on how to make electronics stretchable.As such, it focuses on gathering and evaluating the materials, designs, models and technologies that enable the fabrication of fully elastic electronic devices which can sustain high strain. Furthermore, it provides a review of those specific applications that directly benefit from highly compliant electronics, including transistors, photonic devices and sensors. In addition to stre

  19. Starting electronics

    CERN Document Server

    Brindley, Keith

    2005-01-01

    Starting Electronics is unrivalled as a highly practical introduction for hobbyists, students and technicians. Keith Brindley introduces readers to the functions of the main component types, their uses, and the basic principles of building and designing electronic circuits. Breadboard layouts make this very much a ready-to-run book for the experimenter; and the use of multimeter, but not oscilloscopes, puts this practical exploration of electronics within reach of every home enthusiast's pocket. The third edition has kept the simplicity and clarity of the original. New material

  20. Polymer electronics

    CERN Document Server

    Geoghegan, Mark

    2013-01-01

    Polymer electronics is the science behind many important new developments in technology, such as the flexible electronic display (e-ink) and many new developments in transistor technology. Solar cells, light-emitting diodes, and transistors are all areas where plastic electronics is likely to, or is already having, a serious impact on our daily lives. With polymer transistors and light-emitting diodes now being commercialised, there is a clear need for a pedagogic text thatdiscusses the subject in a clear and concise fashion suitable for senior undergraduate and graduate students. The content

  1. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  2. Electronic Elections

    DEFF Research Database (Denmark)

    Schürmann, Carsten

    2009-01-01

    Electronic voting technology is a two edged sword. It comes with many risks but brings also many benefits. Instead of flat out rejecting the technology as uncontrollably dangerous, we advocate in this paper a different technological angle that renders electronic elections trustworthy beyond...... the usual levels of doubt. We exploit the trust that voters currently have into the democratic process and model our techniques around that observation accordingly. In particular, we propose a technique of trace emitting computations to record the individual steps of an electronic voting machine...... for a posteriori validation on an acceptably small trusted computing base. Our technology enables us to prove that an electronic elections preserves the voter’s intent, assuming that the voting machine and the trace verifier are independent....

  3. Electronic plants

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  4. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    'electronic signature' means data attached to, incorporated in, or logically ... See Cwele v S 2012 4 All SA 497 (SCA); Mohlabeng v Minister of Safety and Security ... ZAKZPHC 51 (2 September 2010); Delta Finance, a Division of Wesbank, ...

  5. Electron Microprobe

    Data.gov (United States)

    Federal Laboratory Consortium — The JEOL JXA-8600 is a conventional hairpin filament thermal emission electron microprobe that is more than 20 years old. It is capable of performing qualitative and...

  6. Electronic commerce

    OpenAIRE

    Veselková, Zdeňka

    2012-01-01

    The thesis deals with a description of electronic commerce from its beginning up to present situation in this area. It explains basic terms connected with electronic commerce and it summarizes the relevant legislation. Moreover it describes e-contracts and rights and duties of both contractual parties. The main view is the view of Internet retailer, which is reflected in the practical part focused on concrete problems of retailers.

  7. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  8. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...

  9. Electron Spectroscopy

    Science.gov (United States)

    Siegbahn, Kai

    Wilhelm Conrad Röntgen's discovery of X radiation in 1895 in Wörzburg resulted in an immediate break-through not only in physics but also in Society, the latter mainly because of its sensational radiological applications. Within a short time it furthermore indirectly led to the discovery of radioactivity by Henri Becquerel. The discovery of X radiation opened the gate to modern atomic physics, and radioactivity to nuclear physics. Later on, the discovery of X-ray diffraction by Laue, Friedrich and Knipping in 1912 initiated the field of X-ray spectroscopy with its fundamental contributions to atomic and crystal structures. Secondary electrons were early observed in the scattered radiation when X-rays were hitting a sample. The development of the corresponding electron spectroscopy had to wait a much longer time for its maturity. A survey of electron spectroscopy is presented.

  10. Electronic Commerce

    Energy Technology Data Exchange (ETDEWEB)

    Laird, N. [NRG Information Services Inc., Calgary, AB (Canada)

    1995-11-01

    The concept of electronic commerce in the gas industry was discussed. It was defined as the integration of communication technology, advanced information processing capability and business standards, to improve effectiveness of the business process. Examples of electronic data interchange from the automotive, airline, and banking industry were given. The objective of using this technology in the gas industry was described as the provision of one electronic facility to make seamless contractual and operational arrangements for moving natural gas across participating pipelines. The benefit of seamless integration - one readily available standard system used by several companies - was highlighted. A list of value-added services such as the free movement of bulletins, directories, nominations,and other documents was provided.

  11. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  12. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    ) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  13. Isolation of nematicidal constituents from essential oil of Kaempferia ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), ... Cambodia, Malaysia and India, but is also widely ... long history of fragrance use to help ... of Genetics and Physiology, Hebei Academy of.

  14. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due...

  15. Superconducting electronics

    NARCIS (Netherlands)

    Rogalla, Horst

    1994-01-01

    During the last decades superconducting electronics has been the most prominent area of research for small scale applications of superconductivity. It has experienced quite a stormy development, from individual low frequency devices to devices with high integration density and pico second switching

  16. Electronic Portfolios.

    Science.gov (United States)

    Purves, Alan C.

    1996-01-01

    Outlines three forms of electronic portfolio based on a student's work, a class project about a specific topic, and a class seminar on a broad topic. Discusses logistical problems of management, access, and cross-referencing; technical problems of input, access, and copying; and theoretical issues of the lack of realia, of ownership and copyright,…

  17. Electronic Money.

    Science.gov (United States)

    Schilling, Tim

    Thirty years ago a cashless society was predicted for the near future; paper currency and checks would be an antiquated symbol of the past. Consumers would embrace a new alternative for making payments: electronic money. But currency is still used for 87% of payments, mainly for "nickel and dime" purchases. And checks are the payment…

  18. Electronic spectroscopies

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Schoonheydt, R.A.

    2000-01-01

    Diffuse reflectance spectroscopy (DRS) in the ultraviolet, visible and near-infrared region is a versatile spectroscopic technique, as both d-d and charge transfer transitions of supported TMI can be probed. One of the advantages of electronic spectroscopy is that the obtained information is

  19. Electronic Homework.

    Science.gov (United States)

    Lee, Fong-lok; Heyworth, Rex M.

    The Electronic Homework assistant system is composed of two components: the Computer Tutor and the Homework Administrator. The Computer Tutor is an intelligent tutoring system that can provide personal assistance like supplying hints, checking errors, providing remediation and prioritizing problems. The Homework Administrator is a teacher's…

  20. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due to po...

  1. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e...

  2. Electronic detectors for electron microscopy.

    Science.gov (United States)

    Faruqi, A R; McMullan, G

    2011-08-01

    Electron microscopy (EM) is an important tool for high-resolution structure determination in applications ranging from condensed matter to biology. Electronic detectors are now used in most applications in EM as they offer convenience and immediate feedback that is not possible with film or image plates. The earliest forms of electronic detector used routinely in transmission electron microscopy (TEM) were charge coupled devices (CCDs) and for many applications these remain perfectly adequate. There are however applications, such as the study of radiation-sensitive biological samples, where film is still used and improved detectors would be of great value. The emphasis in this review is therefore on detectors for use in such applications. Two of the most promising candidates for improved detection are: monolithic active pixel sensors (MAPS) and hybrid pixel detectors (of which Medipix2 was chosen for this study). From the studies described in this review, a back-thinned MAPS detector appears well suited to replace film in for the study of radiation-sensitive samples at 300 keV, while Medipix2 is suited to use at lower energies and especially in situations with very low count rates. The performance of a detector depends on the energy of electrons to be recorded, which in turn is dependent on the application it is being used for; results are described for a wide range of electron energies ranging from 40 to 300 keV. The basic properties of detectors are discussed in terms of their modulation transfer function (MTF) and detective quantum efficiency (DQE) as a function of spatial frequency.

  3. Electronic Aggression

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Aggression is no longer limited to the school yard. New forms of electronic media, such as blogs, instant messaging, chat rooms, email, text messaging, and the internet are providing new arenas for youth violence to occur.  Created: 11/20/2007 by National Center for Injury Prevention and Control, Division of Violence Prevention.   Date Released: 11/28/2007.

  4. Interacting Electrons

    Science.gov (United States)

    Martin, Richard M.; Reining, Lucia; Ceperley, David M.

    2016-06-01

    Preface; Part I. Interacting Electrons: Beyond the Independent-Particle Picture: 1. The many electron problem: introduction; 2. Signatures of electron correlation; 3. Concepts and models for interacting electrons; Part II. Foundations of Theory for Many-Body Systems: 4. Mean fields and auxiliary systems; 5. Correlation functions; 6. Many-body wavefunctions; 7. Particles and quasi-particles; 8. Functionals in many-particle physics; Part III. Many-Body Green's Function Methods: 9. Many-body perturbation theory: expansion in the interaction; 10. Many-body perturbation theory via functional derivatives; 11. The RPA and the GW approximation for the self-energy; 12. GWA calculations in practice; 13. GWA calculations: illustrative results; 14. RPA and beyond: the Bethe-Salpeter equation; 15. Beyond the GW approximation; 16. Dynamical mean field theory; 17. Beyond the single-site approximation in DMFT; 18. Solvers for embedded systems; 19. Characteristic hamiltonians for solids with d and f states; 20. Examples of calculations for solids with d and f states; 21. Combining Green's functions approaches: an outlook; Part IV. Stochastic Methods: 22. Introduction to stochastic methods; 23. Variational Monte Carlo; 24. Projector quantum Monte Carlo; 25. Path integral Monte Carlo; 26. Concluding remarks; Part V. Appendices: A. Second quantization; B. Pictures; C. Green's functions: general properties; D. Matsubara formulation for Green's functions for T ̸= 0; E. Time-ordering, contours, and non-equilibrium; F. Hedin's equations in a basis; G. Unique solutions in Green's function theory; H. Properties of functionals; I. Auxiliary systems and constrained search; J. Derivation of the Luttinger theorem; K. Gutzwiller and Hubbard approaches; References; Index.

  5. ELECTRON GUN

    Science.gov (United States)

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  6. Basic electronics

    CERN Document Server

    Tayal, DC

    2010-01-01

    The second edition of this book incorporates the comments and suggestions of my friends and students who have critically studied the first edition. In this edition the changes and additions have been made and subject matter has been rearranged at some places. The purpose of this text is to provide a comprehensive and up-to-date study of the principles of operation of solid state devices, their basic circuits and application of these circuits to various electronic systems, so that it can serve as a standard text not only for universities and colleges but also for technical institutes. This book

  7. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  8. Electronic Router

    Science.gov (United States)

    Crusan, Jason

    2005-01-01

    Electronic Router (E-Router) is an application program for routing documents among the cognizant individuals in a government agency or other organization. E-Router supplants a prior 14 NASA Tech Briefs, May 2005 system in which paper documents were routed physically in packages by use of paper slips, packages could be lost, routing times were unacceptably long, tracking of packages was difficult, and there was a need for much photocopying. E-Router enables a user to create a digital package to be routed. Input accepted by E-Router includes the title of the package, the person(s) to whom the package is to be routed, attached files, and comments to reviewers. Electronic mail is used to notify reviewers of needed actions. The creator of the package can, at any time, see the status of the package in the routing structure. At the end of the routing process, E-Router keeps a record of the package and of approvals and/or concurrences of the reviewers. There are commercial programs that perform the general functions of E-Router, but they are more complicated. E-Router is Web-based, easy to use, and does not require the installation or use of client software.

  9. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    2013-01-01

    Practical Electronics Handbook, Third Edition provides the frequently used and highly applicable principles of electronics and electronic circuits.The book contains relevant information in electronics. The topics discussed in the text include passive and active discrete components; linear and digital I.C.s; microprocessors and microprocessor systems; digital-analogue conversions; computer aids in electronics design; and electronic hardware components.Electronic circuit constructors, service engineers, electronic design engineers, and anyone with an interest in electronics will find the book ve

  10. Environ: E00353 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00353 Kaempferia galanga rhizome Crude drug Kaempferia galanga [TAX:97750] Zingibe...raceae (ginger family) Kaempferia galanga rhizome Crude drugs [BR:br08305] Monocot plants Zingiberaceae (ginger family) E00353 Kaempferia galanga rhizome ...

  11. Electronic Preprints

    Science.gov (United States)

    Hanisch, R.

    1999-12-01

    Despite the tremendous advances in electronic publications and the increasing rapidity with which papers are now moving from acceptance into ``print,'' preprints continue to be an important mode of communication within the astronomy community. The Los Alamos e-preprint service, astro-ph, provides for rapid and cost-free (to authors and readers) dissemination of manuscripts. As the use of astro-ph has increased the number of paper preprints in circulation to libraries has decreased, and institutional preprint series appear to be waning. It is unfortunate, however, that astro-ph does not function in collaboration with the refereed publications. For example, there is no systematic tracking of manuscripts from preprint to their final, published form, and as a centralized archive it is difficult to distribute the tracking and maintenance functions. It retains documents that have been superseded or have become obsolete. We are currently developing a distributed preprint and document management system which can support both distributed collections of preprints (e.g., traditional institutional preprint series), can link to the LANL collections, can index other documents in the ``grey'' literature (observatory reports, telescope and instrument user's manuals, calls for proposals, etc.), and can function as a manuscript submission tool for the refereed journals. This system is being developed to work cooperatively with the refereed literature so that, for example, links to preprints are updated to links to the final published papers.

  12. Sustainable Management of Electronics

    Science.gov (United States)

    To provide information on EPAs strategy for electronics stewardship, certified electronics recyclers and the Challenge; as well as where to donate unwanted electronics, how to calculate benefits, and what's going on with electronics mgmt in their states.

  13. EDITORIAL: Synaptic electronics Synaptic electronics

    Science.gov (United States)

    Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique

    2013-09-01

    Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic electronics', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the

  14. Electronic Mimosa

    Science.gov (United States)

    Gupta, Sanjay; Datta, Meera S.; Rana, Vivek; Grover, Shailesh

    1996-04-01

    This paper describes the design of a low-cost, 2D, electromagnetic tracking device for personal computers. This interface makes use of the well-known principle of electromagnetic induction to locate the position of a transmitter in an x-y plane. This device has a ring which is worn by the user on the index finger. The computer monitor is overlaid with a transparent screen equipped with tuned electromagnetic sensors. These sensors pick up the signals transmitted by the transmitter coil on the finger. The receiver circuit extracts the envelope of the received signal and digitizes it. These digitized values of x and y axis signals are read by the computer through the standard parallel port. The system software running on the computer calculates the x and y co-ordinates of the transmitter coil and displays a cursor at that location. The transmitter also has a button which can be used like a mouse button. This keypress information is also transmitted by the electromagnetic means. The device driver for this tracker replaces the standard mouse driver. Hence most applications which use a mouse can also use this tracker. Its name `Mimosa' indicates that the user need not touch the screen (Mimosa Pudica is the Latin name of a plant whose leaves wilt when touched). Presently work is on to achieve uniform sensitivity over the entire screen and reducing transmitter power consumption. In order to demonstrate its working, a small, 3D game was written. The player has to reach a pre-defined location after traversing through a maze. The paper describes the interface electronics, system software, mechanical design and the sample application.

  15. Carbon Nanotube Electron Gun

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  16. Nano-Electronics and Bio-Electronics

    Science.gov (United States)

    Srivastava, Deepak; Kwak, Dochan (Technical Monitor)

    2001-01-01

    Viewgraph presentation on Nano-Electronics and Bio-Electronics is discussed. Topics discussed include: NASA Ames nanotechnology program, Potential Carbon Nanotube (CNT) application, CNT synthesis,Computational Nanotechnology, and protein nanotubes.

  17. Electronics for LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance.

  18. Interface Electronic Circuitry for an Electronic Tongue

    Science.gov (United States)

    Keymeulen, Didier; Buehler, Martin

    2007-01-01

    Electronic circuitry has been developed to serve as an interface between an electronic tongue and digital input/output boards in a laptop computer that is used to control the tongue and process its readings. Electronic tongues can be used for a variety of purposes, including evaluating water quality, analyzing biochemicals, analyzing biofilms, and measuring electrical conductivities of soils.

  19. Electron beam focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  20. Electronics and Information

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Previously founded as CCPITMachinery and Electronics Sub-council and CCOIC Machinery and Electronics Chamber of Corn-merce in June, 1988, CCPIT Electronics Sub-Council and CCOIC Electronics Chamber of Commerce were established in May, 1993, and then renamed as CCPIT Electronics and Information Industry Sub-council and CCOIC Electronics and Infor-mation Industry Chamber of Commerce (CCPITECC) in September 1999.

  1. Electronic Correlations in Electron Transfer Systems

    Science.gov (United States)

    Bulla, Ralf; Tornow, Sabine; Anders, Frithjof

    Electron transfer processes play a central role in many chemical and biological systems. Already the transfer of a single electron from the donor to the acceptor can be viewed as a complicated many-body problem, due to the coupling of the electron to the infinitely many environmental degrees of freedom, realized by density fluctuations of the solvent or molecular vibrations of the protein matrix. We focus on the quantum mechanical modelling of two-electron transfer processes whose dynamics is governed by the Coulomb interaction between the electrons as well as the environmental degrees of freedoms represented by a bosonic bath. We identify the regime of parameters in which concerted transfer of the two electrons occurs and discuss the influence of the Coulomb repulsion and the coupling strength to the environment on the electron transfer rate. Calculations are performed using the non-perturbative numerical renormalization group approach for both equilibrium and non-equilibrium properties.

  2. Electron Microscopy Center (EMC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Electron Microscopy Center (EMC) at Argonne National Laboratory develops and maintains unique capabilities for electron beam characterization and applies those...

  3. Investigations on Electronic Materials

    OpenAIRE

    E. Pugnor; T. Kormány

    1982-01-01

    Electronics has been described as a materials oriented technology. In this sense a short review is given concerning: the connection of materials characterization to the design and processing of electronic components; the most important materials characterization methods used for electronic materials; the strategy of organizing a complete material characterization system for selected electronic components.

  4. Electron-attachment processes

    Science.gov (United States)

    Christophorou, L. G.; McCorkle, D. L.; Christodoulides, A. A.

    Topics covered include: modes of production of negative ions, techniques for the study of electron attachment processes, dissociative electron attachment to ground state molecules, dissociative electron attachment to hot molecules (effects of temperature on dissociative electron attachment), molecular parent negative ions, and negative ions formed by ion pair processes and by collisions of molecules with ground state and Rydberg atoms.

  5. Electronic Health Records

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Electronic Health Records KidsHealth > For Teens > Electronic Health Records Print A A A What's in ... t happen overnight, they are coming. Understanding EHRs Electronic health records (EHR) — also called electronic medical records ( ...

  6. Introduction to electronics

    CERN Document Server

    CERN. Geneva

    2005-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  7. Introduction to Electronics course

    CERN Document Server

    CERN. Geneva HR-RFA

    2006-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  8. Electronic Health Records

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Electronic Health Records KidsHealth > For Teens > Electronic Health Records A A A What's in this ... t happen overnight, they are coming. Understanding EHRs Electronic health records (EHR) — also called electronic medical records ( ...

  9. Introduction to Electronic Marketing.

    Science.gov (United States)

    Dilbeck, Lettie

    These materials for a five-unit course were developed to introduce secondary and postsecondary students to the use of electronic equipment in marketing. The units cover the following topics: electronic marketing as a valid marketing approach; telemarketing; radio electronic media marketing; television electronic media marketing; and cable TV…

  10. Hybrid printed electronics

    NARCIS (Netherlands)

    Koetse, M.; Smits, E.; Rubingh, E.; Teunissen, P.; Kusters, R.; Abbel, R.; Brand, J. van den

    2016-01-01

    Although many electronic functionalities can be realized by printed or organic electronics, short-term marketable products often require robust, reproducible, and nondisturbing technologies. In this chapter we show how hybrid electronics, a combination of printed circuitry, thin-film electronics,

  11. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  12. Electronics engineer's reference book

    CERN Document Server

    Mazda, F F

    1989-01-01

    Electronics Engineer's Reference Book, Sixth Edition is a five-part book that begins with a synopsis of mathematical and electrical techniques used in the analysis of electronic systems. Part II covers physical phenomena, such as electricity, light, and radiation, often met with in electronic systems. Part III contains chapters on basic electronic components and materials, the building blocks of any electronic design. Part IV highlights electronic circuit design and instrumentation. The last part shows the application areas of electronics such as radar and computers.

  13. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  14. Electronics engineer's reference book

    CERN Document Server

    Turner, L W

    1976-01-01

    Electronics Engineer's Reference Book, 4th Edition is a reference book for electronic engineers that reviews the knowledge and techniques in electronics engineering and covers topics ranging from basics to materials and components, devices, circuits, measurements, and applications. This edition is comprised of 27 chapters; the first of which presents general information on electronics engineering, including terminology, mathematical equations, mathematical signs and symbols, and Greek alphabet and symbols. Attention then turns to the history of electronics; electromagnetic and nuclear radiatio

  15. Single electron-ics with carbon nanotubes

    NARCIS (Netherlands)

    Götz, G.T.J.

    2010-01-01

    We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for

  16. Electron-electron interactions in disordered systems

    CERN Document Server

    Efros, AL

    1985-01-01

    ``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

  17. VIRTUAL ELECTRONIC COMPONENTS OF THE ELECTRONIC EQUIPMENT

    Directory of Open Access Journals (Sweden)

    E. Lazarevich

    2013-01-01

    Full Text Available The article is present new idea of the creation, developments and improvements of the electronic equipment of complex systems by means of the virtual electronic components. The idea of the virtual electronic components is a presentation and perception of the creation and developments of the equipment on two forming: real – in the manner of standard marketed block of the intellectual property and image – in the manner of virtual component. The real component in most cases slows the development of the electronic equipment. The imaginary component is the «locomotive» of development of the electronic equipment. The Imaginary component contains the scientific has brushed against developer. The scientific has brushed against developer reveals of itself in the manner of virtual component on the modern level of the design rates of microelectronics.

  18. Electron transporting semiconducting polymers in organic electronics.

    Science.gov (United States)

    Zhao, Xingang; Zhan, Xiaowei

    2011-07-01

    Significant progress has been achieved in the preparation of semiconducting polymers over the past two decades, and successful commercial devices based on them are slowly beginning to enter the market. However, most of the conjugated polymers are hole transporting, or p-type, semiconductors that have seen a dramatic rise in performance over the last decade. Much less attention has been devoted to electron transporting, or n-type, materials that have lagged behind their p-type counterparts. Organic electron transporting materials are essential for the fabrication of organic p-n junctions, organic photovoltaic cells (OPVs), n-channel organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs) and complementary logic circuits. In this critical review we focus upon recent developments in several classes of electron transporting semiconducting polymers used in OLEDs, OFETs and OPVs, and survey and analyze what is currently known concerning electron transporting semiconductor architecture, electronic structure, and device performance relationships (87 references).

  19. Relaxant mechanisms of 3, 5, 7, 30, 40-pentamethoxyflavone on isolated human cavernosum

    DEFF Research Database (Denmark)

    Jansakul, Chaweewan; Tachanaparuksa, Kuldej; Mulvany, Michael J.

    2012-01-01

    We have investigated effects and mechanisms responsible for the activity of 3, 5, 7, 30, 40-pentamethoxyflavone (PMF) on isolated human cavernosum. PMF is the major flavone isolated from Kaempferia parviflora claimed to act as an aphrodisiac. PMF caused relaxation of phenylephrine precontracted...... did not significantly inhibit the relaxant activity of glyceryltrinitrate or acetylcholine on human cavernosal strips precontracted with phenylephrine. In contrast, sildenafil (phosphodiesterase inhibitor) potentiated the relaxant activity of glyceryl trinitrate but not of acetylcholine. In normal...... of nitric oxide, and had no effect as a KATP- or KCa channel opener, a phosphodiesterase inhibitor, a store-operated Ca2þ channel blocker or a Rho-kinase inhibitor. Therefore, these studies suggest that PMF causes relaxation of human cavernosum through voltagedependent Ca2þ channels and other mechanisms...

  20. Search for new type of PPARγ agonist-like anti-diabetic compounds from medicinal plants.

    Science.gov (United States)

    Matsuda, Hisashi; Nakamura, Seikou; Yoshikawa, Masayuki

    2014-01-01

    Potent ligands of peroxisome proliferator-activated receptor γ (PPARγ) such as thiazolidinediones (pioglitazone, troglitazone, etc.) improve insulin sensitivity by increasing the levels of adiponectin, an important adipocytokine associated with insulin sensitivity in adipose tissue. Several constituents from medicinal plants were recently reported to show PPARγ agonist-like activity in 3T3-L1 cells, but did not show agonistic activity at the receptor site different from thiazolidinediones. Our recent studies on PPARγ agonist-like constituents, such as hydrangenol and hydrangeic acid from the processed leaves of Hydrangea macrophylla var. thunbergii, piperlonguminine and retrofractamide A from the fruit of Piper chaba, and tetramethylkaempferol and pentamethylquercetin from the rhizomes of Kaempferia parviflora, are reviewed.

  1. Electronics for dummies

    CERN Document Server

    Shamieh

    2015-01-01

    Explore the basic concepts of electronics, build your electronics workbench, and begin creating fun electronics projects right away! Electronics For Dummies, 3rd Edition is your guide to the world of electronics. Spanning circuitry, wiring, robotics, transmitters, amplifiers, and more, this book demystifies electricity basics and beyond. The third edition offers new content revised to reflect the latest advancements in the electronics field, and it offers full color project examples to spark your creativity and inspire you to put your new skills to use! Packed with projects that can be comple

  2. High energy electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Parkhomchuk, V. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)

    1997-09-01

    High energy electron cooling requires a very cold electron beam. The questions of using electron cooling with and without a magnetic field are presented for discussion at this workshop. The electron cooling method was suggested by G. Budker in the middle sixties. The original idea of the electron cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both electron and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.

  3. RHIC electron lenses upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Binello, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Costanzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Pikin, A. I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Shrey, T. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tan, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  4. Electronic Commerce and Competitive Procurement

    Science.gov (United States)

    1991-06-01

    Explains the application of electronic commerce techniques (electronic data interchange (EDI), electronic mail (E-mail), electronic bulletin boards...purchase procedures of the Federal Acquisition Regulation (FAR). Changes to the FAR to recognize electronic commerce are recommended. Also discussed...are opportunities to use electronic commerce and small business and legal considerations of electronic commerce . This report describes how electronic

  5. Certified Electronics Recyclers

    Science.gov (United States)

    Learn how EPA encourages all electronics recyclers become certified by demonstrating to an accredited, independent third-party auditor and that they meet specific standards to safely recycle and manage electronics.

  6. Chapter 9: Electronics

    OpenAIRE

    Spieler, Helmuth G

    2008-01-01

    Sophisticated front-end electronics are a key part of practically all modern radiation detector systems. This chapter introduces the basic principles and their implementation. Topics include signal acquisition, electronic noise, pulse shaping (analog and digital), and data readout techniques.

  7. Chapter 9: Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Grupen, Claus; Shwartz, Boris A.

    2006-12-19

    Sophisticated front-end electronics are a key part of practically all modern radiation detector systems. This chapter introduces the basic principles and their implementation. Topics include signal acquisition, electronic noise, pulse shaping (analog and digital), and data readout techniques.

  8. Presidential Electronic Records Library

    Data.gov (United States)

    National Archives and Records Administration — PERL (Presidential Electronic Records Library) used to ingest and provide internal access to the Presidential electronic Records of the Reagan, Bush, and Clinton...

  9. THE ELECTRONIC SIGNATURE

    Directory of Open Access Journals (Sweden)

    Voiculescu Madalina Irena

    2009-05-01

    Full Text Available Article refers to significance and the digital signature in electronic commerce. Internet and electronic commerce open up many new opportunities for the consumer, yet, the security (or perceived lack of security of exchanging personal and financial data

  10. Electronic Submission of Labels

    Science.gov (United States)

    Pesticide registrants can provide draft and final labels to EPA electronically for our review as part of the pesticide registration process. The electronic submission of labels by registrants is voluntary but strongly encouraged.

  11. Chapter 9: Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Grupen, Claus; Shwartz, Boris A.

    2006-12-19

    Sophisticated front-end electronics are a key part of practically all modern radiation detector systems. This chapter introduces the basic principles and their implementation. Topics include signal acquisition, electronic noise, pulse shaping (analog and digital), and data readout techniques.

  12. Laboratory Handbook Electronics

    CERN Multimedia

    1966-01-01

    Laboratory manual 1966 format A3 with the list of equipment cables, electronic tubes, chassis, diodes transistors etc. One of CERN's first material catalogue for construction components for mechanical and electronic chassis.

  13. Electron shuttles in biotechnology.

    Science.gov (United States)

    Watanabe, Kazuya; Manefield, Mike; Lee, Matthew; Kouzuma, Atsushi

    2009-12-01

    Electron-shuttling compounds (electron shuttles [ESs], or redox mediators) are essential components in intracellular electron transfer, while microbes also utilize self-produced and naturally present ESs for extracellular electron transfer. These compounds assist in microbial energy metabolism by facilitating electron transfer between microbes, from electron-donating substances to microbes, and/or from microbes to electron-accepting substances. Artificially supplemented ESs can create new routes of electron flow in the microbial energy metabolism, thereby opening up new possibilities for the application of microbes to biotechnology processes. Typical examples of such processes include halogenated-organics bioremediation, azo-dye decolorization, and microbial fuel cells. Herein we suggest that ESs can be applied widely to create new microbial biotechnology processes.

  14. Electronics materials research

    Science.gov (United States)

    1982-01-01

    The electronic materials and is aimed at the establishment of quantitative relationships underlying crystal growth parameters, materials properties, electronic characteristics and device applications. The overall program evolves about the following main thrust areas: (1) crystal growth novel approaches to engineering of semiconductor materials; (2) investigation of materials properties and electronic characteristics on a macro and microscale; (3) surface properties and surface interactions with the bulk and ambients; (4) electronic properties controlling device applications and device performance.

  15. Thermography of electronic devices

    OpenAIRE

    Panfilova S. P.; Vlasov A. I.; Gridnev V. N.; Chervinsky A. S.

    2007-01-01

    The possibility of application of thermography to diagnose the electronic devices is analyzed in the article. Typical faults of electronic devices which can be found by means of thermography are given. Advantages of noncontact thermal inspection in comparison with the contact one are described. Some features of thermography of electronic devices are considered. Thermography apparatus is viewed and some pieces of advice about choosing it for electronic devices diagnosis are given. An example o...

  16. Electronics and computer acronyms

    CERN Document Server

    Brown, Phil

    1988-01-01

    Electronics and Computer Acronyms presents a list of almost 2,500 acronyms related to electronics and computers. The material for this book is drawn from a number of subject areas, including electrical, electronics, computers, telecommunications, fiber optics, microcomputers/microprocessors, audio, video, and information technology. The acronyms also encompass avionics, military, data processing, instrumentation, units, measurement, standards, services, organizations, associations, and companies. This dictionary offers a comprehensive and broad view of electronics and all that is associated wi

  17. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  18. Mechanical Engineering for Electronics.

    OpenAIRE

    Was, Loïc

    2012-01-01

    Schlumberger drilling tools are exposed to very hard loading conditions (shocks, vibrations, thermal cycling) while performing a job. As these tools are full of electronics, issues can quickly come from electronics failure. Mechanisms of failure occurring in electronics are very complex but can be predicted in some cases. The first part of the thesis describes in which context mechanical engineering applied to electronics is used in Schlumberger. The different kinds of failure which will be i...

  19. Handbook on electronic commerce

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M. [Illinois Univ., Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology; Blanning, R. [Vanderbilt Univ., Nashville, TN (United States). Owen Graduate School of Management; Strader, T. [Iowa State Univ., Ames, IA (United States). Management Information Systems; Whinston, A. [eds.] [Texas Univ., Austin, TX (United States). Dept. of Management Science and Information Systems

    2000-07-01

    The world is undergoing a revolution to a digital economy, with pronounced implications for corporate strategy, marketing, operations, information systems, customer services, global supply-chain management, and product distribution. This handbook examines the aspects of electronic commerce, including electronic storefront, on-line business, consumer interface, business-to-business networking, digital payment, legal issues, information product development, and electronic business models. Indispensable for academics, students and professionals who are interested in Electronic Commerce and Internet Business. (orig.)

  20. Atomicity in Electronic Commerce,

    Science.gov (United States)

    1996-01-01

    tremendous demand for the ability to electronically buy and sell goods over networks. Electronic commerce has inspired a large variety of work... commerce . It then briefly surveys some major types of electronic commerce pointing out flaws in atomicity. We pay special attention to the atomicity...problems of proposals for digital cash. The paper presents two examples of highly atomic electronic commerce systems: NetBill and Cryptographic Postage Indicia.

  1. Syringe-injectable electronics.

    Science.gov (United States)

    Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M

    2015-07-01

    Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

  2. Technology of Electronic Signatur

    OpenAIRE

    2004-01-01

    An electronic signature uses a hash of message and an asymetrical algorithm of encryption for its generation. During verification of message on receiver side the hash of original message must be identical with the hash of received message. Electronic message is secured autentization of author and integrity of transmission date. By electronic signature it is possible to sign everything what is in digital form.

  3. ELECTRONS IN NONPOLAR LIQUIDS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLROYD,R.A.

    2002-10-22

    Excess electrons can be introduced into liquids by absorption of high energy radiation, by photoionization, or by photoinjection from metal surfaces. The electron's chemical and physical properties can then be measured, but this requires that the electrons remain free. That is, the liquid must be sufficiently free of electron attaching impurities for these studies. The drift mobility as well as other transport properties of the electron are discussed here as well as electron reactions, free-ion yields and energy levels, Ionization processes typically produce electrons with excess kinetic energy. In liquids during thermalization, where this excess energy is lost to bath molecules, the electrons travel some distance from their geminate positive ions. In general the electrons at this point are still within the coulombic field of their geminate ions and a large fraction of the electrons recombine. However, some electrons escape recombination and the yield that escapes to become free electrons and ions is termed G{sub fi}. Reported values of G{sub fi} for molecular liquids range from 0.05 to 1.1 per 100 eV of energy absorbed. The reasons for this 20-fold range of yields are discussed here.

  4. Syringe injectable electronics

    Science.gov (United States)

    Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-01-01

    Seamless and minimally-invasive three-dimensional (3D) interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating syringe injection and subsequent unfolding of submicrometer-thick, centimeter-scale macroporous mesh electronics through needles with a diameter as small as 100 micrometers. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with > 90% device yield. We demonstrate several applications of syringe injectable electronics as a general approach for interpenetrating flexible electronics with 3D structures, including (i) monitoring of internal mechanical strains in polymer cavities, (ii) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (iii) in vivo multiplexed neural recording. Moreover, syringe injection enables delivery of flexible electronics through a rigid shell, delivery of large volume flexible electronics that can fill internal cavities and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics. PMID:26053995

  5. Arduino electronics blueprints

    CERN Document Server

    Wilcher, Don

    2015-01-01

    This book is intended for those who want to learn about electronics and coding by building amazing devices and gadgets with Arduino. If you are an experienced developer who understands the basics of electronics, then you can quickly learn how to build smart devices using Arduino. The only experience needed is a desire to learn about electronics, circuit breadboarding, and coding.

  6. Electron measurement in PHENIX

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, Y. [Univ. of Tokyo, Tanashi (Japan)

    1995-07-15

    Electron Measurement in PHENIX detector at RHIC is discussed. The yield and S/N ratio at vector meson peaks ({phi}, {omega}, {rho}{sup o}, and J/{psi}) are evaluated. The electrons from open charm decay, and its consequence to the di-electron measurements is discussed.

  7. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  8. Polarized Electron Source Developments

    Energy Technology Data Exchange (ETDEWEB)

    Charles K. Sinclair

    1990-02-23

    Presently, only two methods of producing beams of polarized electrons for injection into linear accelerators are in use. Each of these methods uses optical pumping by circularly polarized light to produce electron polarization. In one case, electron polarization is established in metastable helium atoms, while in the other case, the polarized electrons are produced in the conduction band of appropriate semiconductors. The polarized electrons are liberated from the helium metastable by chemi-ionization, and from the semiconductors by lowering the work function at the surface of the material. Developments with each of these sources since the 1988 Spin Physics Conference are reviewed, and the prospects for further improvements discussed.

  9. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  10. Ultracold Ordered Electron Beam

    Science.gov (United States)

    Habs, D.; Kramp, J.; Krause, P.; Matl, K.; Neumann, R.; Schwalm, D.

    1988-01-01

    We have started an experimental program to develop an ultracold electron beam, which can be used together with a standard electron cooling device in the Heidelberg Test Storage Ring TSR. In contrast to the standard-type design using electron beam extraction from a heated cathode, the ultracold beam is produced by photoemission of electrons from a cooled semiconductor crystal irradiated with an intense near-infrared laser light beam. Adiabatic acceleration is expected to provide ordering of the electron beam itself. Besides the cooling of ion beams to extremely low temperatures, with the aim of obtaining crystallization, the ultracold beam will constitute an excellent target for atomic physics experiments.

  11. Ultracold ordered electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Habs, D.; Kramp, J.; Krause, P.; Matl, K.; Neumann, R.; Schwalm, D.

    1988-01-01

    We have started an experimental program to develop an ultracold electron beam, which can be used together with a standard electron cooling device in the Heidelberg Test Storage Ring TSR. In contrast to the standard-type design using electron beam extraction beam extraction from a heated cathode, the ultracold beam is produced by photoemission of electrons from a cooled semiconductor crystal irradiated with an intense near-infrared laser light beam. Adiabatic acceleration is expected to provide ordering of the electron beam itself. Besides the cooling of ion beams to extremely low temperatures, with the aim of obtaining crystallization, the ultracold beam will constitute an excellent target for atomic physics experiments.

  12. Electronic equipment packaging technology

    CERN Document Server

    Ginsberg, Gerald L

    1992-01-01

    The last twenty years have seen major advances in the electronics industry. Perhaps the most significant aspect of these advances has been the significant role that electronic equipment plays in almost all product markets. Even though electronic equipment is used in a broad base of applications, many future applications have yet to be conceived. This versatility of electron­ ics has been brought about primarily by the significant advances that have been made in integrated circuit technology. The electronic product user is rarely aware of the integrated circuits within the equipment. However, the user is often very aware of the size, weight, mod­ ularity, maintainability, aesthetics, and human interface features of the product. In fact, these are aspects of the products that often are instrumental in deter­ mining its success or failure in the marketplace. Optimizing these and other product features is the primary role of Electronic Equipment Packaging Technology. As the electronics industry continues to pr...

  13. Advanced adhesives in electronics

    CERN Document Server

    Bailey, C

    2011-01-01

    Adhesives are widely used in the manufacture of electronic devices to act as passive and active components. Recently there has been considerable interest in the use of conductive adhesives. This book reviews key types of conductive adhesives, processing methods, properties and the way they can be modelled as well as potential applications.$bAdhesives for electronic applications serve important functional and structural purposes in electronic components and packaging, and have developed significantly over the last few decades. Advanced adhesives in electronics reviews recent developments in adhesive joining technology, processing and properties. The book opens with an introduction to adhesive joining technology for electronics. Part one goes on to cover different types of adhesive used in electronic systems, including thermally conductive adhesives, isotropic and anisotropic conductive adhesives and underfill adhesives for flip-chip applications. Part two focuses on the properties and processing of electronic ...

  14. Electron crystallography and aquaporins.

    Science.gov (United States)

    Schenk, Andreas D; Hite, Richard K; Engel, Andreas; Fujiyoshi, Yoshinori; Walz, Thomas

    2010-01-01

    Electron crystallography of two-dimensional (2D) crystals can provide information on the structure of membrane proteins at near-atomic resolution. Originally developed and used to determine the structure of bacteriorhodopsin (bR), electron crystallography has recently been applied to elucidate the structure of aquaporins (AQPs), a family of membrane proteins that form pores mostly for water but also other solutes. While electron crystallography has made major contributions to our understanding of the structure and function of AQPs, structural studies on AQPs, in turn, have fostered a number of technical developments in electron crystallography. In this contribution, we summarize the insights electron crystallography has provided into the biology of AQPs, and describe technical advancements in electron crystallography that were driven by structural studies on AQP 2D crystals. In addition, we discuss some of the lessons that were learned from electron crystallographic work on AQPs.

  15. Automotive electronics design fundamentals

    CERN Document Server

    Zaman, Najamuz

    2015-01-01

    This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

  16. Medan Electronic Mall Arsitektur Ikonik

    OpenAIRE

    David,, A.

    2014-01-01

    With present the Medan Electronic Mall is intended to meet the needs of electronic goods from electronic of communication, Office Electronics, Household Electronics, Hobbies or electronic game, Medan Electronic Mall also hosts for the people of North Sumatra Province especially for people of Medan City to get particular information will be the development of electronic goods and also enjoy all kinds of things related to electronics such as Game Center, Cyber/Virtual Game, Internet...

  17. Engineered phages for electronics.

    Science.gov (United States)

    Cui, Yue

    2016-11-15

    Phages are traditionally widely studied in biology and chemistry. In recent years, engineered phages have attracted significant attentions for functionalization or construction of electronic devices, due to their specific binding, catalytic, nucleating or electronic properties. To apply the engineered phages in electronics, these are a number of interesting questions: how to engineer phages for electronics? How are the engineered phages characterized? How to assemble materials with engineered phages? How are the engineered phages micro or nanopatterned? What are the strategies to construct electronics devices with engineered phages? This review will highlight the early attempts to address these questions and explore the fundamental and practical aspects of engineered phages in electronics, including the approaches for selection or expression of specific peptides on phage coat proteins, characterization of engineered phages in electronics, assembly of electronic materials, patterning of engineered phages, and construction of electronic devices. It provides the methodologies and opens up ex-cit-ing op-por-tu-ni-ties for the development of a variety of new electronic materials and devices based on engineered phages for future applications.

  18. Scanning ultrafast electron microscopy.

    Science.gov (United States)

    Yang, Ding-Shyue; Mohammed, Omar F; Zewail, Ahmed H

    2010-08-24

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability.

  19. Scanning ultrafast electron microscopy

    Science.gov (United States)

    Yang, Ding-Shyue; Mohammed, Omar F.; Zewail, Ahmed H.

    2010-01-01

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability. PMID:20696933

  20. Metamaterials for Ballistic Electrons

    CERN Document Server

    Dragoman, D; Dragoman, Daniela; Dragoman, Mircea

    2007-01-01

    The paper presents a metamaterial for ballistic electrons, which consists of a quantum barrier formed in a semiconductor with negative effective electron mass. This barrier is the analogue of a metamaterial for electromagnetic waves in media with negative electrical permittivity and magnetic permeability. Besides applications similar to those of optical metamaterials, a nanosized slab of a metamaterial for ballistic electrons, sandwiched between quantum wells of positive effective mass materials, reveals unexpected conduction properties, e.g. single or multiple room temperature negative differential conductance regions at very low voltages and with considerable peak-to-valley ratios, while the traversal time of ballistic electrons can be tuned to larger or smaller values than in the absence of the metamaterial slab. Thus, slow and fast electrons, analogous to slow and fast light, occur in metamaterials for ballistic electrons.

  1. Electrons in Nanostructures

    DEFF Research Database (Denmark)

    Flindt, Christian

    2007-01-01

    or a few electrons. Such few-electron devices are expected to form the building blocks of future electrical circuits and it is thus necessary to develop a thorough theoretical understanding of the physics of electrons in nanostructures. Re- garding applications there is a particular interest......-based communication. The statistical description of electron transport through nanostructures is based on rate equations, and the primary contribution of the thesis in that respect is the development of a method that allows for the calculation of the distribution of electrons passing through a device. The method......This thesis concerns theoretical aspects of electrons in man-made nanostruc- tures. Advances in nanofabrication technology during recent decades have made it possible to produce electrical devices on the nano-scale, whose func- tionality is determined by the quantum mechanical nature of a single...

  2. Single electron spintronics.

    Science.gov (United States)

    Dempsey, Kari J; Ciudad, David; Marrows, Christopher H

    2011-08-13

    Single electron electronics is now well developed, and allows the manipulation of electrons one-by-one as they tunnel on and off a nanoscale conducting island. In the past decade or so, there have been concerted efforts in several laboratories to construct single electron devices incorporating ferromagnetic components in order to introduce spin functionality. The use of ferromagnetic electrodes with a non-magnetic island can lead to spin accumulation on the island. On the other hand, making the dot also ferromagnetic introduces new physics such as tunnelling magnetoresistance enhancement in the cotunnelling regime and manifestations of the Kondo effect. Such nanoscale islands are also found to have long spin lifetimes. Conventional spintronics makes use of the average spin-polarization of a large ensemble of electrons: this new approach offers the prospect of accessing the quantum properties of the electron, and is a candidate approach to the construction of solid-state spin-based qubits.

  3. Electron transfer in proteins

    DEFF Research Database (Denmark)

    Farver, O; Pecht, I

    1991-01-01

    Electron migration between and within proteins is one of the most prevalent forms of biological energy conversion processes. Electron transfer reactions take place between active centers such as transition metal ions or organic cofactors over considerable distances at fast rates and with remarkable...... specificity. The electron transfer is attained through weak electronic interaction between the active sites, so that considerable research efforts are centered on resolving the factors that control the rates of long-distance electron transfer reactions in proteins. These factors include (in addition......-containing proteins. These proteins serve almost exclusively in electron transfer reactions, and as it turns out, their metal coordination sites are endowed with properties uniquely optimized for their function....

  4. Nanocrystals for electronics.

    Science.gov (United States)

    Panthani, Matthew G; Korgel, Brian A

    2012-01-01

    Semiconductor nanocrystals are promising materials for low-cost large-area electronic device fabrication. They can be synthesized with a wide variety of chemical compositions and size-tunable optical and electronic properties as well as dispersed in solvents for room-temperature deposition using various types of printing processes. This review addresses research progress in large-area electronic device applications using nanocrystal-based electrically active thin films, including thin-film transistors, light-emitting diodes, photovoltaics, and thermoelectrics.

  5. Technology of Electronic Signatur

    Directory of Open Access Journals (Sweden)

    Jaroslav Sadovsky

    2004-01-01

    Full Text Available An electronic signature uses a hash of message and an asymetrical algorithm of encryption for its generation. During verification of message on receiver side the hash of original message must be identical with the hash of received message. Electronic message is secured autentization of author and integrity of transmission date. By electronic signature it is possible to sign everything what is in digital form.

  6. Modern electronic materials

    CERN Document Server

    Watkins, John B

    2013-01-01

    Modern Electronic Materials focuses on the development of electronic components. The book first discusses the history of electronic components, including early developments up to 1900, developments up to World War II, post-war developments, and a comparison of present microelectric techniques. The text takes a look at resistive materials. Topics include resistor requirements, basic properties, evaporated film resistors, thick film resistors, and special resistors. The text examines dielectric materials. Considerations include basic properties, evaporated dielectric materials, ceramic dielectri

  7. Field emission electron source

    Science.gov (United States)

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  8. Introduction to electronics

    CERN Document Server

    Korneff, Theodore

    1966-01-01

    Introduction to Electronics focuses on the study of electronics and electronic devices. Composed of 14 chapters, the book starts with discussions on dc circuits, including resistance, voltmeter, ammeter, galvanometer, internal resistance, and positive and negative currents. This topic is followed by discussions on ac circuits, particularly addressing voltage and current, average power, resistive load, complex plane, and parallel circuits. Discussions also focus on filters and tuned circuits, diodes, and power supplies. Particularly given attention are the processes, diagrams, and analyses

  9. ETHICS AND ELECTRONIC VOTING

    OpenAIRE

    2014-01-01

    13 pages; International audience; In the first part, we will define the main properties of a democratic election, providing a typology of electronic devices and give a view on some legal documents pertaining to the matter. In the second part, the ethics of voting will be evaluated: our methodology is detailed, followed by an examination of pure paper-based elections, paperless electronic voting and verifiable electronic voting. The new concept of legally operative transparency is defined and ...

  10. Electronic collection management

    CERN Document Server

    Mcginnis, Suzan D

    2013-01-01

    Build and manage your collection of digital resources with these successful strategies! This comprehensive volume is a practical guide to the art and science of acquiring and organizing electronic resources. The collections discussed here range in size from small college libraries to large research libraries, but all are facing similar problems: shrinking budgets, increasing demands, and rapidly shifting formats. Electronic Collection Management offers new ideas for coping with these issues. Bringing together diverse aspects of collection development, Electronic Collection

  11. Introduction to printed electronics

    CERN Document Server

    Suganuma, Katsuaki

    2014-01-01

    This book describes in detail modern technologies for printed electronics, explaining how nanotechnology and modern printing technology are merging to revolutionize electronics fabrication of thin, lightweight, large, and inexpensive products. Readers will benefit from the explanations of materials, devices and circuits used to design and implement the latest applications of printed electronics, such as thin flexible OLED displays, organic solar cells, OLED lighting, smart wallpaper, sensors, logic, memory and more.

  12. Electronic signal conditioning

    CERN Document Server

    NEWBY, BRUCE

    1994-01-01

    At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

  13. Flying Electronic Warfare Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides NP-3D aircraft host platforms for Effectiveness of Navy Electronic Warfare Systems (ENEWS) Program antiship missile (ASM) seeker simulators used...

  14. Smart Electronic Textiles.

    Science.gov (United States)

    Weng, Wei; Chen, Peining; He, Sisi; Sun, Xuemei; Peng, Huisheng

    2016-05-17

    This Review describes the state-of-the-art of wearable electronics (smart textiles). The unique and promising advantages of smart electronic textiles are highlighted by comparing them with the conventional planar counterparts. The main kinds of smart electronic textiles based on different functionalities, namely the generation, storage, and utilization of electricity, are then discussed with an emphasis on the use of functional materials. The remaining challenges are summarized together with important new directions to provide some useful clues for the future development of smart electronic textiles.

  15. Electronic Wallets in Danger

    Directory of Open Access Journals (Sweden)

    Jean-Michel Sahut

    2006-10-01

    Full Text Available The erratic development of electronic wallets (EW illustrates thedifficulties of their adoption by the general public and shopkeepersalike. With exceptions, such as Proton in Europe and Octopus in Asia,a lot of electronic wallets are likely to disappear in the next fewyears. Yet the key factors of success are known by banks which oftenchoose to ignore them. However, the strategic change taken by some inorder to bring a fresh start to electronic wallets like Moneo couldreverse the tendency. Nevertheless, it will still be necessary to waitseveral years before seeing electronic wallets really imposethemselves as a credible alternative to payments in cash.

  16. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  17. Fundamentals of electronics

    CERN Document Server

    Schubert, Thomas F

    2015-01-01

    This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to

  18. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

    High-Power Electronics, Volume 2 presents the electronic processes in devices of the magnetron type and electromagnetic oscillations in different systems. This book explores the problems of electronic energetics.Organized into 11 chapters, this volume begins with an overview of the motion of electrons in a flat model of the magnetron, taking into account the in-phase wave and the reverse wave. This text then examines the processes of transmission of electromagnetic waves of various polarization and the wave reflection from grids made of periodically distributed infinite metal conductors. Other

  19. Electron correlation in molecules

    CERN Document Server

    Wilson, S

    2007-01-01

    Electron correlation effects are of vital significance to the calculation of potential energy curves and surfaces, the study of molecular excitation processes, and in the theory of electron-molecule scattering. This text describes methods for addressing one of theoretical chemistry's central problems, the study of electron correlation effects in molecules.Although the energy associated with electron correlation is a small fraction of the total energy of an atom or molecule, it is of the same order of magnitude as most energies of chemical interest. If the solution of quantum mechanical equatio

  20. Flying Electronic Warfare Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides NP-3D aircraft host platforms for Effectiveness of Navy Electronic Warfare Systems (ENEWS) Program antiship missile (ASM) seeker simulators used...

  1. Electronics pocket book

    CERN Document Server

    Parr, E A

    1981-01-01

    Electronics Pocket Book, Fourth Edition is a nonmathematical presentation of the many varied topics covered by electronics. The book tackles electron physics, electronic components (i.e. resistors, capacitors, and conductors), integrated circuits, and the principles of a.c. and d.c. amplifiers. The text also discusses oscillators, digital circuits, digital computers, and optoelectronics (i.e., sensors, emitters, and devices that utilize light). Communications (such as line and radio communications, transmitters, receivers, and digital techniques); the principles and examples of servosystems; a

  2. Flexible Electronics Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Flexible Electronics Research Facility designs, synthesizes, tests, and fabricates materials and devices compatible with flexible substrates for Army information...

  3. Electron Transfer Chain Catalysis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Electron-transfer chain (ETC) catalysis belongs to the family of chain reactions where the electron is the catalyst. The ETC mechanism could be initiated by chemical activation, electrochemistry, or photolysis. If this pathway is applied to the preparation of organometallic complexes, it utilizes the greatly enhanced reactivity of organometallic 17e and 19e radicals. The chemical propagation is followed by the cross electron-transfer while the electron-transfer step is also followed by the chemical propagation, creating a loop in which reactants are facilely transformed into products. Interestingly the overall reaction is without any net redox change.

  4. Electron Transfer Chain Catalysis

    Institute of Scientific and Technical Information of China (English)

    LIU; LingKang

    2001-01-01

    Electron-transfer chain (ETC) catalysis belongs to the family of chain reactions where the electron is the catalyst. The ETC mechanism could be initiated by chemical activation, electrochemistry, or photolysis. If this pathway is applied to the preparation of organometallic complexes, it utilizes the greatly enhanced reactivity of organometallic 17e and 19e radicals. The chemical propagation is followed by the cross electron-transfer while the electron-transfer step is also followed by the chemical propagation, creating a loop in which reactants are facilely transformed into products. Interestingly the overall reaction is without any net redox change.  ……

  5. Nanosecond electron microscopes

    Science.gov (United States)

    Bostanjoglo; Elschner; Mao; Nink; Weingartner

    2000-04-01

    Combining electron optics, fast electronics and pulsed lasers, a transmission and a photoelectron emission microscope were built, which visualize events in thin films and on surfaces with a time resolution of several nanoseconds. The high-speed electron microscopy is capable to track fast laser-induced processes in metals below the ablation threshold, which are difficult to detect by other imaging techniques. The material response to nano- and femtosecond laser pulses was found to be very different. It was dominated by thermo/chemocapillary flow and chemical reactions in the case of nanosecond pulses, and by mechanical deformations and non-thermal electron emission after a femtosecond pulse.

  6. Electron caustic lithography

    Directory of Open Access Journals (Sweden)

    S. M. Kennedy

    2012-06-01

    Full Text Available A maskless method of electron beam lithography is described which uses the reflection of an electron beam from an electrostatic mirror to produce caustics in the demagnified image projected onto a resist–coated wafer. By varying the electron optics, e.g. via objective lens defocus, both the morphology and dimensions of the caustic features may be controlled, producing a range of bright and tightly focused projected features. The method is illustrated for line and fold caustics and is complementary to other methods of reflective electron beam lithography.

  7. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  8. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  9. (Pulsed electron beam precharger)

    Energy Technology Data Exchange (ETDEWEB)

    Finney, W.C. (ed.); Shelton, W.N.

    1990-01-01

    This report discusses the following topics on electron beam guns: Precharger Modification; Installation of Charge vs. Radius Apparatus; High Concentration Aerosol Generation; and Data Acquisition and Analysis System.

  10. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  11. Electronics Environmental Benefits Calculator

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Electronics Environmental Benefits Calculator (EEBC) was developed to assist organizations in estimating the environmental benefits of greening their purchase,...

  12. Electronic Service Statistics - Quarterly Report

    Data.gov (United States)

    Social Security Administration — This is a quarterly report that compares electronic data vs non-electronic data for electronic services. Report contains six main sections namely, electronic access,...

  13. Optical Electronics. Electronics Module 9. Instructor's Guide.

    Science.gov (United States)

    Franken, Bill

    This module is the ninth of 10 modules in the competency-based electronics series. Introductory materials include a listing of competencies addressed in the module, a parts/equipment list, and a cross reference table of instructional materials. Five instructional units cover: fiber optic cable; optical coupler; lasers and masers; optical displays;…

  14. Antimicrobial, antioxidant activities and chemical composition of selected Thai spices

    Directory of Open Access Journals (Sweden)

    Juraithip Wungsintaweekul

    2010-12-01

    Full Text Available Nine volatile oils and six methanol extracts from Ocimum americanum, O. basilicum, O. sanctum, Citrus hystrix,Alpinia galanga, Curcuma zedoaria, Kaempferia parviflora and Zingiber cassumunar were assessed for antimicrobial andantioxidant activities. The volatile oils and extracts were investigated against eight bacteria and three fungi. The resultsillustrated that O. americanum volatile oil exhibited broad spectrum activity against tested bacteria with the MICs ranging1.4-3.6 mg/ml and Candida spp. with the MICs ranging from 0.5-0.6 mg/ml. The O. sanctum volatile oil showed a considerableactivity against only Candida spp. with the MICs ranging from 0.8-1.4 mg/ml. Interestingly, growth of Mycobacteriumphlei was inhibited by the volatiles of O. americanum, C. hystrix peel, and C. zedoaria with MIC of 1.7, 3.5 and 1.2 mg/ml,respectively. For antioxidant activity evaluation, the methanol extracts of C. hystrix (leaf and peel and K. parviflora hadpotent antioxidant activity by the radical-scavenging DPPH method with IC50 of 24.6, 66.3 and 61.5 mg/ml, respectively.GC-MS analysis revealed the typical chemical profiles of the volatile oils. The major component showed the characteristicsof the volatile oils and was probably responsible for the antimicrobial effect.

  15. Notes on Electronic Lexicography

    CERN Document Server

    Parvanov, Yavor

    2011-01-01

    These notes are a continuation of topics covered by V. Selegej in his article "Electronic Dictionaries and Computational lexicography". How can an electronic dictionary have as its object the description of closely related languages? Obviously, such a question allows multiple answers.

  16. Managing electronic records

    CERN Document Server

    McLeod, Julie

    2005-01-01

    For records management courses, this book covers the theory and practice of managing electronic records as business and information assets. It focuses on the strategies, systems and procedures necessary to ensure that electronic records are appropriately created, captured, organized and retained over time to meet business and legal requirements.

  17. STEP electronic system design

    Science.gov (United States)

    Couch, R. H.; Johnson, J. W.

    1984-01-01

    The STEP electronic system design is discussed. The purpose of the design is outlined. The electronic system design is summarized and it is found that: an effective conceptual system design is developed; the design represents a unique set of capabilities; makes efficient use of available orbiter resources; the system capabilities exceed identified potential experiment needs.

  18. Electron tunnel sensor technology

    Science.gov (United States)

    Waltman, S. B.; Kaiser, W. J.

    1989-01-01

    The recent development of Scanning Tunneling Microscopy technology allows the application of electron tunneling to position detectors for the first time. The vacuum tunnel junction is one of the most sensitive position detection mechanisms available. It is also compact, simple, and requires little power. A prototype accelerometer based on electron tunneling, and other sensor applications of this promising new technology are described.

  19. Electron scattering violates parity

    CERN Multimedia

    2004-01-01

    Parity violation has been observed in collisions between electrons at the Stanford Linear Accelerator Center (SLAC) in the US. The resuls, which are in agreement with the Stanford Model of particle physics, also provide a new measurement of the weak charge of the electron (½ page)

  20. Pulsed Plasma Electron Sources

    Science.gov (United States)

    Krasik, Yakov

    2008-11-01

    Pulsed (˜10-7 s) electron beams with high current density (>10^2 A/cm^2) are generated in diodes with electric field of E > 10^6 V/cm. The source of electrons in these diodes is explosive emission plasma, which limits pulse duration; in the case E Hadas and Ya. E. Krasik, Europhysics Lett. 82, 55001 (2008).

  1. Electron transfer in peptides.

    Science.gov (United States)

    Shah, Afzal; Adhikari, Bimalendu; Martic, Sanela; Munir, Azeema; Shahzad, Suniya; Ahmad, Khurshid; Kraatz, Heinz-Bernhard

    2015-02-21

    In this review, we discuss the factors that influence electron transfer in peptides. We summarize experimental results from solution and surface studies and highlight the ongoing debate on the mechanistic aspects of this fundamental reaction. Here, we provide a balanced approach that remains unbiased and does not favor one mechanistic view over another. Support for a putative hopping mechanism in which an electron transfers in a stepwise manner is contrasted with experimental results that support electron tunneling or even some form of ballistic transfer or a pathway transfer for an electron between donor and acceptor sites. In some cases, experimental evidence suggests that a change in the electron transfer mechanism occurs as a result of donor-acceptor separation. However, this common understanding of the switch between tunneling and hopping as a function of chain length is not sufficient for explaining electron transfer in peptides. Apart from chain length, several other factors such as the extent of the secondary structure, backbone conformation, dipole orientation, the presence of special amino acids, hydrogen bonding, and the dynamic properties of a peptide also influence the rate and mode of electron transfer in peptides. Electron transfer plays a key role in physical, chemical and biological systems, so its control is a fundamental task in bioelectrochemical systems, the design of peptide based sensors and molecular junctions. Therefore, this topic is at the heart of a number of biological and technological processes and thus remains of vital interest.

  2. Single particle electron microscopy

    NARCIS (Netherlands)

    Boekema, Egbert J.; Folea, Mihaela; Kouril, Roman; Kouřil, Roman

    2009-01-01

    Electron microscopy (EM) in combination with image analysis is a powerful technique to study protein structures at low, medium, and high resolution. Since electron micrographs of biological objects are very noisy, improvement of the signal-to-noise ratio by image processing is an integral part of EM

  3. Electronic Mail Connections.

    Science.gov (United States)

    Tucker, Susan A.

    1987-01-01

    Provides an overview of new developments in electronic mail, including the interconnection of online networks, some on an international level; and news on system upgrades of specific information services. The growth of the electronic mail industry and possible future trends are discussed and a glossary of technical terms is included. (CLB)

  4. Electronically Controlled Resistor Bank

    Science.gov (United States)

    Ross, Walter L.

    1987-01-01

    Resistance quickly varied in small steps over wide range. Device with no moving parts provides variable electrical resistance. Used with analog or digital circuity to provide electronic selection of large number of resistance values for testing, simulation, control, or other purposes. Nearest electromechanical equivalent of all-electronic device is potentiometer driven by servomotor.

  5. Electronics and Lithuanian Terminology

    Directory of Open Access Journals (Sweden)

    Stasys Zajankauskas

    2011-04-01

    Full Text Available It is found that the vacuum triode, transistor, monolithic circuit and microprocessor were the most important inventions of traditional electronics. Thus, the origins of the traditional electronics should be associated with the invention of the vacuum triode, but not with the invention of vacuum diode. It is shown that the science of electronics is not as young as computer science or up-to-date information technologies: electronics, including active electronics, had already celebrated the centenary, and the period of 2004–2008 is the period of numerous already solid jubilees. Thus, the terminology of electronics is not at initial stage of evolution as well – general terms should be already systematized and normalized. However, Lithuanian terms for electronic devices invented before tens of years and terms for old-defined notions associated with these devices are still varying, some are worsened. Especially, the incorrectly motivated terms used for variations of transistors and microcircuits are analyzed in the article. It is motivated which terms are preferable, systematic and exact. The paper is dedicated to the 50th anniversary of monolithic circuit, as well as the 60th anniversary of transistor, the 40th jubilee of microprocessor and centenary of electronics.

  6. Electronically Induced Phase Transformations

    Science.gov (United States)

    1980-12-01

    ries (w hen the Slater free-electron exchange is used). A systematic the active researcher. study of relativistic electron densities and isomer...comp:wrees aux mesures actuelles d’effet dHvA d’Arko et Schirber. Le calu; du facteur de forme neutronique en presence d’un champ magnetique est en bon

  7. Green and biodegradable electronics

    Directory of Open Access Journals (Sweden)

    Mihai Irimia-Vladu

    2012-07-01

    Full Text Available We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials suggest they will be useful in biofunctional electronics; demonstrating functions that would be inaccessible for traditional inorganic compounds. Such materials may lead to fully biodegradable and even biocompatible/biometabolizable electronics for many low-cost applications. This review highlights recent progress in these classes of material, covering substrates and insulators, semiconductors, and finally conductors.

  8. LEIR electron cooler status

    CERN Document Server

    Tranquille, G; Parkhomchuk, V; Prieto, V; Sautier, R

    2006-01-01

    The electron cooler for LEIR is the first of a new generation of coolers being commissioned for fast phase space cooling of ion beams in storage rings. It is a stateof- the-art cooler incorporating all the recent developments in electron cooling technology (adiabatic expansion, electrostatic bend, variable density electron beam) and is designed to deliver up to 600 mA of electron current for the cooling and stacking of Pb54+ ions in the frame of the ions for LHC project. In this paper we present our experience with the commissioning of the new device as well as the first results of ion beam cooling with a high-intensity variable-density electron beam.

  9. Electron Cyclotron Emission Radiometer

    Science.gov (United States)

    Morales, Cristina

    2009-11-01

    There is much interest in studying plasmas that generate hot electrons. The goal of this project is to develop a wide band electron cyclotron radiometer to measure the non-Maxwellian rapid rises in electron temperature. These rapid increases in temperature will then be correlated to instabilities in the plasma. This project explores a type of noncontact temperature measurement. We will attempt to show the feasibility of electron cyclotron emissions to measure the Maryland Centrifugal Experiment's electron plasma temperature. The radiometer has been designed to have 100dB of gain and a sensitivity of 24mV/dB given by its logarithmic amplifier. If successful, this radiometer will be used as a diagnostic tool in later projects such as the proposed experiment studying magnetic reconnection using solar flux loops.

  10. Practical electronics for inventors

    CERN Document Server

    Scherz, Paul

    2013-01-01

    Spark your creativity and gain the electronics skills required to transform your innovative ideas into functioning gadgets. This hands-on, updated guide outlines electrical principles and provides thorough, easy-to-follow instructions, schematics, and illustrations. Findout how to select components, safely assemble circuits, perform error tests, and build plug-and-play prototypes. Practical Electronics for Inventors, Third Edition, features all-new chapters on sensors, microcontrollers, modular electronics, and the latest software tools. Coverage includes: Resistors, capacitors, inductors, and transformers Diodes, transistors, and integrated circuits Optoelectronics, solar cells, and phototransistors Sensors, GPS modules, and touch screens Op amps, regulators, and power supplies Digital electronics, LCD displays, and logic gates Microcontrollers and prototyping platforms, including Arduino DC motors, RC servos, and stepper motors Microphones, audio amps, and speakers Modular electronics and prototyping.

  11. Simulations of Gaussian electron guns for RHIC electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  12. Electronic Collection Management and Electronic Information Services

    Science.gov (United States)

    2003-04-01

    TITLE: Electronic Information Management for PfP Nations [La gestion electronique des informations pour les pays du PfP] To order the complete...banking and securities trading. E- commerce has moved into many other areas and it is now possible to purchase a wide variety of goods and services on line...include interactive e- commerce and e-governance services as well as various organizational database management needs (including registrations, membership

  13. Electron Cooling of RHIC

    CERN Document Server

    Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

    2005-01-01

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

  14. Dissociative Electron Attachment

    Science.gov (United States)

    Arreola, Esmeralda; Esmeralda Arreola Collaboration; Leigh Hargreaves Collaboration

    Since the pioneering work of Boudiaffa et al., it has been understood that electrons, even with energies near or below the ionization threshold, are capable of initiating strand-breaks in human DNA. This discovery raised important questions for cancer treatments, since sub-ionizing electrons are known to be the most copiously produced secondary product of radiation therapy. But even to date these factors are largely excluded from dosimetry calculations. This lack of inclusion is, at least in part, certainly due to the dearth of fundamental data describing low-energy electron interactions with nucleotide molecules that form the basis of DNA. Understanding of how such slow electrons are able to damage DNA remains incomplete, but the strongly peaked nature of Boudiaffa et al.'s data gives strong hints at resonantly driven collision processes. DNA damage is therefore most likely driven by ``dissociative electron attachment'' (DEA). DEA is a rather complicated process to model due to the coupling of electronic and nuclear degrees of freedom in the molecule. At the California State University Fullerton, we are currently commissioning a new spectrometer to study dissociation channels, reaction rates and orientation effects in DEA collisions between slow electrons and nucleotide molecules. At the meeting we will present design parameters and commissioning data for this new apparatus.

  15. Electron heat flux instability

    Science.gov (United States)

    Saeed, Sundas; Sarfraz, M.; Yoon, P. H.; Lazar, M.; Qureshi, M. N. S.

    2017-02-01

    The heat flux instability is an electromagnetic mode excited by a relative drift between the protons and two-component core-halo electrons. The most prominent application may be in association with the solar wind where drifting electron velocity distributions are observed. The heat flux instability is somewhat analogous to the electrostatic Buneman or ion-acoustic instability driven by the net drift between the protons and bulk electrons, except that the heat flux instability operates in magnetized plasmas and possesses transverse electromagnetic polarization. The heat flux instability is also distinct from the electrostatic counterpart in that it requires two electron species with relative drifts with each other. In the literature, the heat flux instability is often called the 'whistler' heat flux instability, but it is actually polarized in the opposite sense to the whistler wave. This paper elucidates all of these fundamental plasma physical properties associated with the heat flux instability starting from a simple model, and gradually building up more complexity towards a solar wind-like distribution functions. It is found that the essential properties of the instability are already present in the cold counter-streaming electron model, and that the instability is absent if the protons are ignored. These instability characteristics are highly reminiscent of the electron firehose instability driven by excessive parallel temperature anisotropy, propagating in parallel direction with respect to the ambient magnetic field, except that the free energy source for the heat flux instability resides in the effective parallel pressure provided by the counter-streaming electrons.

  16. Aerogels for electronics

    Energy Technology Data Exchange (ETDEWEB)

    Hrubesh, L.W.

    1994-10-01

    In addition to their other exceptional properties, aerogels also exhibit unusual dielectric and electronic properties due to their nano-sized structures and high porosities. For example, aerogels have the lowest dielectric constants measured for a solid material (having values approaching 1.0); they have exceptionally high dielectric resistivities and strengths (i.e., ability to insulate very high voltages); they exhibit low dielectric loss at microwave frequencies; and some aerogels are electrically conductive and photoconductive. These properties are being exploited to provide the next generation of materials for energy storage, low power consumption, and ultra-fast electronics. We are working toward adapting these unusual materials for microelectronic applications, particularly, making thin aerogel films for dielectric substrates and for energy storage devices such as supercapacitors. Measurements are presented in this paper for the dielectric and electronic properties of aerogels, including the dielectric constant, loss factor, dielectric and electrical conductivity, volume resistivity, and dielectric strength. We also describe methods to form and characterize thin aerogel films which are being developed for numerous electronic applications. Finally, some of the electronic applications proposed for aerogels are presented. Commercialization of aerogels for electronics must await further feasibility, prototype development, and cost studies, but they are one of the key materials and are sure to have a major impact on future electronics.

  17. Coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko,V.

    2009-05-04

    Cooling intense high-energy hadron beams remains a major challenge in modern accelerator physics. Synchrotron radiation is still too feeble, while the efficiency of two other cooling methods, stochastic and electron, falls rapidly either at high bunch intensities (i.e. stochastic of protons) or at high energies (e-cooling). In this talk a specific scheme of a unique cooling technique, Coherent Electron Cooling, will be discussed. The idea of coherent electron cooling using electron beam instabilities was suggested by Derbenev in the early 1980s, but the scheme presented in this talk, with cooling times under an hour for 7 TeV protons in the LHC, would be possible only with present-day accelerator technology. This talk will discuss the principles and the main limitations of the Coherent Electron Cooling process. The talk will describe the main system components, based on a high-gain free electron laser driven by an energy recovery linac, and will present some numerical examples for ions and protons in RHIC and the LHC and for electron-hadron options for these colliders. BNL plans a demonstration of the idea in the near future.

  18. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  19. Power Electronics for Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Blaabjerg, Frede

    2016-01-01

    A microgrid (MG) is a stand-alone or grid-connected hybrid renewable system that uses distributed renewable and nonrenewable energy sources and energy storage systems (ESSs) to supply power to local loads. The system is ordinarily based on power electronics, with interface converters allowing...... a continuous supply of power in the presence of variable RES production. This chapter describes some specific features of DC MGs in terms of power architecture, control, and protection. It also reviews several uncommon power electronic interfaces. Regarding control, operation without critical communication...... are explained in this chapter. The chapter concludes with a review of power electronic intensive protection solutions for DC MGs....

  20. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H

    1969-01-01

    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  1. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  2. Consulting in Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Florentina Loredana Tache

    2010-10-01

    Full Text Available Economic development of electronic services provide advice and many agents of existingreferral systems to recommend and provide products, information and customized views of thecommunity through a personalized interaction in real time. Distributed systems of autonomous agentsare becoming increasingly important in electronic comet because the basic decisions of agents adviceon trust and reputation are taken in a similar way human society. If these decisions will be as a realconsumer protection, when new aspects of online consumer legislation will become usefulinformation in advice and consulting of electronic commerce.

  3. Electron Beam Materials Irradiators

    Science.gov (United States)

    Cleland, Marshall R.

    2012-06-01

    Radiation processing is a well established method for enhancing the properties of materials and commercial products by treating them with ionizing energy in the form of high-energy electrons, X-rays, and gamma rays. Beneficial effects include polymerizing, cross-linking, grafting and degrading plastics, sterilizing single-use medical devices, disinfecting and disinfesting fresh foods, purifying drinking water, treating wastewater and other toxic waste materials that harm the environment, and many other applications that are still being evaluated. Industrial electron accelerators of several types have been developed and are being used for these applications. More than 1800 electron accelerators are presently installed in facilities worldwide for these purposes.

  4. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  5. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  6. Principles of quantum electronics

    CERN Document Server

    Marcuse, Dietrich

    1980-01-01

    Principles of Quantum Electronics focuses on the concept of quantum electronics as the application of quantum theory to engineering problems. It examines the principles that govern specific quantum electronics devices and presents their theoretical applications to typical problems. Comprised of 10 chapters, this book starts with an overview of the Dirac formulation of quantum mechanics. This text then considers the derivation of the formalism of field quantization and discusses the properties of photons and phonons. Other chapters examine the interaction between the electromagnetic field and c

  7. VLSI electronics microstructure science

    CERN Document Server

    1982-01-01

    VLSI Electronics: Microstructure Science, Volume 4 reviews trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the silicon-on-insulator for VLSI and VHSIC, X-ray lithography, and transient response of electron transport in GaAs using the Monte Carlo method. The technology and manufacturing of high-density magnetic-bubble memories, metallic superlattices, challenge of education for VLSI, and impact of VLSI on medical signal processing are also elaborated. This text likewise covers the impact of VLSI t

  8. Coding for Electronic Mail

    Science.gov (United States)

    Rice, R. F.; Lee, J. J.

    1986-01-01

    Scheme for coding facsimile messages promises to reduce data transmission requirements to one-tenth current level. Coding scheme paves way for true electronic mail in which handwritten, typed, or printed messages or diagrams sent virtually instantaneously - between buildings or between continents. Scheme, called Universal System for Efficient Electronic Mail (USEEM), uses unsupervised character recognition and adaptive noiseless coding of text. Image quality of resulting delivered messages improved over messages transmitted by conventional coding. Coding scheme compatible with direct-entry electronic mail as well as facsimile reproduction. Text transmitted in this scheme automatically translated to word-processor form.

  9. TIS - Beyond Electronic Mail.

    Science.gov (United States)

    1979-01-01

    AD-AI06 764 AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH F/G 17/2 TIS - BEYOND ELECTRONIC MAIL .(U) 1979 D L OLSON, N T FLYNN, M I DARWISH...79-22§1_ 4~~~~~~~ SIXi.m.aihl -- . TYPE OF REPORT & PERIOD covERED TIS -SBeyond Electronic Mail . TlSS~cnA~r 6 PEFRI4 O11G. REPORT NUMBER Duane L.A:o...single-service provisions of so-called " electronic mail ." Approaches to be used in implementing a TIS are considered, and a time-frame scenario is

  10. Electron paramagnetic resonance

    CERN Document Server

    Al'tshuler, S A

    2013-01-01

    Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an

  11. Reliable Electronic Equipment

    Directory of Open Access Journals (Sweden)

    N. A. Nayak

    1960-05-01

    Full Text Available The reliability aspect of electronic equipment's is discussed. To obtain optimum results, close cooperation between the components engineer, the design engineer and the production engineer is suggested.

  12. The art of electronics

    CERN Document Server

    Horowitz, Paul

    2015-01-01

    At long last, here is the thoroughly revised and updated third edition of the hugely successful Art of Electronics. It is widely accepted as the best single authoritative book on electronic circuit design. In addition to new or enhanced coverage of many topics, the Third Edition includes: 90 oscilloscope screenshots illustrating the behavior of working circuits; dozens of graphs giving highly useful measured data of the sort that's often buried or omitted in datasheets but which you need when designing circuits; 80 tables (listing some 1650 active components), enabling intelligent choice of circuit components by listing essential characteristics (both specified and measured) of available parts. The new Art of Electronics ​​retains the feeling of informality and easy access that helped make the earlier editions so successful and popular. It is an indispensable reference and the gold standard​​ for anyone, student or researcher, professional or amateur, who works with electronic circuits.

  13. Electronic Universal Vote

    Directory of Open Access Journals (Sweden)

    Cristian USCATU

    2008-01-01

    Full Text Available In the days of informational society everything is going online. Most aspects of our lives have online components. Since democracy is a big issue, it could not escape this trend. Governments themselves are moving to the online environment for the purpose of improving their internal efficiency and their availability to the citizens, businesses and other parties interested. Since governments are the result of elections, elections have also been touched by the electronic fever. New electronic voting solutions arise and each one brings new debates with many arguments in their favor and against them. Accessibility and ease of use leads the arguments in favor of electronic voting over the internet, while fear of fraud is the main reason people are avoiding electronics and clinging on classic paper ballots.

  14. Electron gun for SSRF

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A 100 kV triode-electron-gun has been designed and manufactured for the Linac of Shanghai Synchrotron Radiation Facility (SSRF). In this paper the performance of the gun and some key components are described.

  15. Pulsed plasma electron sourcesa)

    Science.gov (United States)

    Krasik, Ya. E.; Yarmolich, D.; Gleizer, J. Z.; Vekselman, V.; Hadas, Y.; Gurovich, V. Tz.; Felsteiner, J.

    2009-05-01

    There is a continuous interest in research of electron sources which can be used for generation of uniform electron beams produced at E ≤105 V/cm and duration ≤10-5 s. In this review, several types of plasma electron sources will be considered, namely, passive (metal ceramic, velvet and carbon fiber with and without CsI coating, and multicapillary and multislot cathodes) and active (ferroelectric and hollow anodes) plasma sources. The operation of passive sources is governed by the formation of flashover plasma whose parameters depend on the amplitude and rise time of the accelerating electric field. In the case of ferroelectric and hollow-anode plasma sources the plasma parameters are controlled by the driving pulse and discharge current, respectively. Using different time- and space-resolved electrical, optical, spectroscopical, Thomson scattering and x-ray diagnostics, the parameters of the plasma and generated electron beam were characterized.

  16. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope. Specifications / Capabilities: Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  17. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  18. Telecommunications--Electronic Mail.

    Science.gov (United States)

    Kelly, Luke E.; Zuckerman, B. Michael

    1989-01-01

    This article identifies resources needed in order for physical education, recreation, and dance professionals to use computer-based telecommunications; discusses electronic mail; and explains how telecommunications can enhance communication in the field, both within and across professions. (IAH)

  19. Introduction to electron crystallography.

    Science.gov (United States)

    Kühlbrandt, Werner

    2013-01-01

    From the earliest work on regular arrays in negative stain, electron crystallography has contributed greatly to our understanding of the structure and function of biological macromolecules. The development of electron cryo-microscopy (cryo-EM) then lead to the first groundbreaking atomic models of the membrane proteins bacteriorhodopsin and light harvesting complex II within lipid bilayers. Key contributions towards cryo-EM and electron crystallography methods included specimen preparation and vitrification, liquid-helium cooling, data collection, and image processing. These methods are now applied almost routinely to both membrane and soluble proteins. Here we outline the advances and the breakthroughs that paved the way towards high-resolution structures by electron crystallography, both in terms of methods development and biological milestones.

  20. Electron and Photon ID

    CERN Document Server

    Hryn'ova, Tetiana; The ATLAS collaboration

    2017-01-01

    The identification of prompt photons and the rejection of background coming mostly from photons from hadron decays relies on the high granularity of the ATLAS calorimeter. The electron identification used in ATLAS for run 2 is based on a likelihood discrimination to separate isolated electron candidates from candidates originating from photon conversions, hadron misidentification and heavy flavor decays. In addition, isolation variables are used as further handles to separate signal and background. Several methods are used to measure with data the efficiency of the photon identification requirements, to cover a broad energy spectrum. At low energy, photons from radiative Z decays are used. In the medium energy range, similarities between electrons and photon showers are exploited using Z->ee decays. At high energy, inclusive photon samples are used. The measurement of the efficiencies of the electron identification and isolation cuts are performed with the data using tag and probe techniques with large statis...

  1. Electronics Modernization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current electronic packaging designs used in our most recent spacecraft are comprised of technologies from the 1980’s and 1990’s. The current approach...

  2. Electronics for guitarists

    CERN Document Server

    Dailey, Denton J

    2014-01-01

    Electronics for Guitarists focuses on analog circuitry, and is written for the guitarist interested in transistor and vacuum tube-based amplifiers. Topics include discrete transistors and diodes, classical filter circuits, and vacuum tube-based amplifiers.

  3. ELECTRONIC BANKING AND ELECTRONIC COMMERCE IN SERBIA

    Directory of Open Access Journals (Sweden)

    Ivana B. Petrevska

    2014-10-01

    Full Text Available Nowadays, we may witness to dramatic and visible changes in our life environment. Business ambient for companies is different every day, and it is very hard to predict a direction of future changes. There is an environment characterized by sharp competition and increasing number of competitors, fast technological improvements and highly sophisticated and informed costumers. Technological process influences the humanity strongly, changing the way that people live, work and spend. Electronic commerce and electronic banking has become incontinent, and makes a great part of today's total transactions. There are an increasing number of companies that perform their business that way and make profit. Social networks are proven to be the least expensive way of information exchange, and they are present in almost every part of the world. The globalization has reached the most distant parts of the Earth. Every resistance to new technologies is dangerous and may lead to bankruptcy. Due to the EU expansion, Internet users are to be expected, and prosperity of the e-commerce business models at the same time. In Serbia, electronic commerce is present, but not as developed as in EU countries. E-commerce, however it might be successful throughout the world, it is somewhat slow in its growth in Serbia. The reasons are numerous, and main obstacles are the lack of trust, still limited usage of banking cards, avoiding of e-payments by older population etc. Also, the recent scandals over the misuse of personal data, and e-crime are discouraging factors for the growth of e-trade and ebanking. The younger generations are ever more ready to use e-commerce, since they are open to new technologies and do not have the defensive attitude towards it. E-commerce and e-banking has growing potential even among older population, if the society prevents them from fear and mistrust.

  4. Cooling of electronic equipment

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    2003-01-01

    Cooling of electronic equipment is studied. The design size of electronic equipment decrease causing the thermal density to increase. This affect the cooling which can cause for example failures of critical components due to overheating or thermal induced stresses. Initially a pin fin heat sink...... is considered as extruded profiles are inadequate for compact designs. An optimal pin fin shape and configuration is sought also taking manufacturing costs into consideration. Standard methods for geometrical modeling and thermal analysis are applied....

  5. Electronic states of myricetin

    DEFF Research Database (Denmark)

    Vojta, Danijela; Karlsen, Eva; Spanget-Larsen, Jens

    2017-01-01

    Myricetin (3,3',4',5,5',7'-hexahydroxyflavone) was investigated by linear dichroism spectroscopy on molecular samples partially aligned in stretched poly(vinyl alcohol) (PVA). At least five electronic transitions in the range 40000 – 20000 cm–1 were characterized with respect to their wavenumbers......, relative intensities, and transition moment directions. The observed bands were assigned to electronic transitions predicted with TD-B3LYP/6-31+G(d,p)....

  6. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  7. Electron Beam Ion Sources

    OpenAIRE

    Zschornacka, G.; Schmidt, M.; Thorn, A.

    2014-01-01

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviole...

  8. 4D Electron Tomography

    OpenAIRE

    Kwon, Oh-Hoon; Zewail, Ahmed H.

    2010-01-01

    Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a mov...

  9. Mathematics for electronic technology

    CERN Document Server

    Howson, D P

    1975-01-01

    Mathematics for Electronic Technology is a nine-chapter book that begins with the elucidation of the introductory concepts related to use of mathematics in electronic engineering, including differentiation, integration, partial differentiation, infinite series, vectors, vector algebra, and surface, volume and line integrals. Subsequent chapters explore the determinants, differential equations, matrix analysis, complex variable, topography, graph theory, and numerical analysis used in this field. The use of Fourier method for harmonic analysis and the Laplace transform is also described. The ma

  10. Electron scattering experiments

    Science.gov (United States)

    Heisenberg, J.

    1984-11-01

    Because of the elementary structure of the electron, it is considered a precise probe of the constituent nature of hadronic matter. Use of the electron as a probe of subnucleonic degrees of freedom in nuclei is discussed in this presentation. Experimentally determined charge distributions for a wide variety of nuclei are presented and compared with shell model calculations which include single particle modes, core polarization, corrections due to delta-hole components, and corrections due to inclusion of meson exchange currents. (AIP)

  11. Electronic Portfolios for Scientists

    OpenAIRE

    Dahn, I.; Christmann, A.

    2007-01-01

    Electronic portfolios (ePortfolios) are electronic versions of paper based portfolios. They are increasingly applied in education. Software for building and maintaining ePortfolios is emerging; open specifications for the exchange of ePortfolios exist. They show the potential to serve as a standard tool for documenting achievements in lifelong learning. In this paper we explore the potential of ePortfolios for scientists.

  12. Electrical and electronic principles

    CERN Document Server

    Knight, SA

    1988-01-01

    Electrical and Electronic Principles, 3 focuses on the principles involved in electrical and electronic circuits, including impedance, inductance, capacitance, and resistance.The book first deals with circuit elements and theorems, D.C. transients, and the series circuits of alternating current. Discussions focus on inductance and resistance in series, resistance and capacitance in series, power factor, impedance, circuit magnification, equation of charge, discharge of a capacitor, transfer of power, and decibels and attenuation. The manuscript then examines the parallel circuits of alternatin

  13. The Recycler Electron Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Prost, L. R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-03-19

    The Recycler Electron cooler was the first (and so far, the only) cooler working at a relativistic energy (γ = 9.5). It was successfully developed in 1995-2004 and was in operation at Fermilab in 2005-2011, providing cooling of antiprotons in the Recycler ring. This paper describes the cooler, difficulties in achieving the required electron beam parameters and the ways to overcome them, cooling measurements, and details of operation.

  14. Trust in Consumer Electronics

    Science.gov (United States)

    Kursawe, Klaus; Katzenbeisser, Stefan

    While Trusted Computing is getting increasing attention in the PC world, consumer electronics devices have limited benefit from the Trusted Computing solutions currently under development. In this paper we outline the different requirements of consumer electronics devices, when compared to the PC world, and point out the technical consequences for standards like the Trusted Computing Group. In addition, we will touch on economic aspects that may inhibit or support Trusted Computing in this domain.

  15. Electron spectroscopy analysis

    Science.gov (United States)

    Gregory, John C.

    1992-01-01

    The Surface Science Laboratories at the University of Alabama in Huntsville (UAH) are equipped with x-ray photoelectron spectroscopy (XPS or ESCA) and Auger electron spectroscopy (AES) facilities. These techniques provide information from the uppermost atomic layers of a sample, and are thus truly surface sensitive. XPS provides both elemental and chemical state information without restriction on the type of material that can be analyzed. The sample is placed into an ultra high vacuum (UHV) chamber and irradiated with x-rays which cause the ejection of photoelectrons from the sample surface. Since x-rays do not normally cause charging problems or beam damage, XPS is applicable to a wide range of samples including metals, polymers, catalysts, and fibers. AES uses a beam of high energy electrons as a surface probe. Following electronic rearrangements within excited atoms by this probe, Auger electrons characteristic of each element present are emitted from the sample. The main advantage of electron induced AES is that the electron beam can be focused down to a small diameter and localized analysis can be carried out. On the rastering of this beam synchronously with a video display using established scanning electron microscopy techniques, physical images and chemical distribution maps of the surface can be produced. Thus very small features, such as electronic circuit elements or corrosion pits in metals, can be investigated. Facilities are available on both XPS and AES instruments for depth-profiling of materials, using a beam of argon ions to sputter away consecutive layers of material to reveal sub-surface (and even semi-bulk) analyses.

  16. Newnes electronics toolkit

    CERN Document Server

    Phillips, Geoff

    2013-01-01

    Newnes Electronics Toolkit brings together fundamental facts, concepts, and applications of electronic components and circuits, and presents them in a clear, concise, and unambiguous format, to provide a reference book for engineers. The book contains 10 chapters that discuss the following concepts: resistors, capacitors, inductors, semiconductors, circuit concepts, electromagnetic compatibility, sound, light, heat, and connections. The engineer's job does not end when the circuit diagram is completed; the design for the manufacturing process is just as important if volume production is to be

  17. Electronic states of myricetin

    DEFF Research Database (Denmark)

    Vojta, Danijela; Karlsen, Eva; Spanget-Larsen, Jens

    2016-01-01

    Myricetin (3,3',4',5,5',7'-hexahydroxyflavone) was investigated by linear dichroism spectroscopy on molecular samples partially aligned in stretched poly(vinyl alcohol) (PVA). At least five electronic transitions in the range 40000 – 20000 cm–1 were characterized with respect to their wavenumbers......, relative intensities, and transition moment directions. The observed bands were assigned to electronic transitions predicted with TD-B3LYP/6-31+G(d,p)....

  18. Electronics 3 checkbook

    CERN Document Server

    Knight, S A; May, A J C

    2013-01-01

    Electronics 3 Checkbook provides a concise coverage of the theories and definitions of concepts in electronics. The book provides problems and worked examples to supplement fuller textbooks of the same subject. The coverage of the text includes decibel measurement, operational amplifiers, DA and AD converters, controlled rectifiers, triggering devices, optoelectronic devices, fiber optics, and power amplifiers. The text will be of great use to electrical engineering students who wish to enhance their understanding of the basics of mechanical and electrical science.

  19. Electron Transfer Pathways in Cell

    OpenAIRE

    Yan Liu

    2012-01-01

    Analysis of the electron salvation process data indicates that the electron transfer between the electron donor and acceptor is hindered by the electron salvation process. It is proposed that the electron transfer in the cell environment must be assisted by intermediate messenger called the “transport protein”.

  20. Thermionics basic principles of electronics

    CERN Document Server

    Jenkins, J; Ashhurst, W

    2013-01-01

    Basic Principles of Electronics, Volume I : Thermionics serves as a textbook for students in physics. It focuses on thermionic devices. The book covers topics on electron dynamics, electron emission, and the themionic vacuum diode and triode. Power amplifiers, oscillators, and electronic measuring equipment are studied as well. The text will be of great use to physics and electronics students, and inventors.

  1. Netiquette in Electronic Communication

    Directory of Open Access Journals (Sweden)

    Tomáš Kozík

    2014-06-01

    Full Text Available Electronic mail and electronic communications systems are considered significant and effective tools of communication. One of the most widespread electronic communication tools is e - mail communication. In order to avoid misinterpretation of the report on the side of the recipient, it is need to pay attention to the writing of e - mail messages as well as to their content. With the continuous expansion of the use of electronic communication there have gradually developed certain rules of etiquette in electronic communications. The existing rules of the propriety ones are expressed in the term " etiqutte " and are not automatically applied in the new communications environment - media. For electronic communication, the new rules of etiquette have been stabilised into a term NETIQUETTE. The word netiquette was created by combining words NET (net and ETIKETA (a set of rules of social behavior and habits. Netiquette constitutes the rules of the behavior of users on a network. Although the netiquette is merely "an unwritten set of rules", their not using can be understood as a type of disrespect. Analysis of knowledge of domestic and foreign sources as well as results of a survey confirmed the justification of paying attention to the education of individuals in NETIQUETTE, irrespective of the degree of education.

  2. BOK-Printed Electronics

    Science.gov (United States)

    Ghaffarian, Reza

    2013-01-01

    The use of printed electronics technologies (PETs), 2D or 3D printing approaches either by conventional electronic fabrication or by rapid graphic printing of organic or nonorganic electronic devices on various small or large rigid or flexible substrates, is projected to grow exponentially in commercial industry. This has provided an opportunity to determine whether or not PETs could be applicable for low volume and high-reliability applications. This report presents a summary of literature surveyed and provides a body of knowledge (BOK) gathered on the current status of organic and printed electronics technologies. It reviews three key industry roadmaps- on this subject-OE-A, ITRS, and iNEMI-each with a different name identification for this emerging technology. This followed by a brief review of the status of the industry on standard development for this technology, including IEEE and IPC specifications. The report concludes with key technologies and applications and provides a technology hierarchy similar to those of conventional microelectronics for electronics packaging. Understanding key technology roadmaps, parameters, and applications is important when judicially selecting and narrowing the follow-up of new and emerging applicable technologies for evaluation, as well as the low risk insertion of organic, large area, and printed electronics.

  3. Good Security Practices for Electronic Commerce, Including Electronic Data Interchange

    Science.gov (United States)

    1993-12-01

    FROM - TO) xx-xx-2002 to xx-xx-2002 4. TITLE AND SUBTITLE Good Security Practices for Electronic Commerce , Including Electronic Data Interchange...Report 12/1/1993 4. TITLE AND SUBTITLE Good Security Practices for Electronic Commerce , Including Electronic Data Interchange 5. FUNDING NUMBERS 6...Maximum 200 Words) Electronic commerce (EC) is the use of documents in electronic form, rather than paper, for carrying out functions of business or

  4. Electron holes in inhomogeneous magnetic field: electron heating and electron hole evolution

    Science.gov (United States)

    Vasko, Ivan; Agapitov, Oleksiy; Mozer, Forrest; Artemyev, Anton; Drake, James

    2016-04-01

    Electron holes are electrostatic non-linear structures widely observed in the space plasma, e.g., in reconnecting current sheets, collisionless bow shocks, Earth auroral region and outer radiation belt etc. In the present paper we analyze the process of energy exchange between trapped electrons, untrapped electrons and electron hole propagating in weakly inhomogeneous magnetic field. We show that as electron hole propagates into the region with stronger magnetic field, trapped electrons are heated due to conservation of the first adiabatic invariant. At the same time electron hole may grow or dissipate in dependence on peculiarities of distribution functions of trapped and resonant untrapped electrons. The energy gain of trapped electrons is due to energy losses of resonant electrons and/or decrease of electron hole energy (electrostatic energy and kinetic energy of non-resonant electrons). We stress that taking into account the energy exchange with resonant untrapped electrons increases the heating factor of trapped electrons that is proportional to the magnetic field magnitude in the region up to what electron holes survive. We illustrate the suggested mechanism for H. Schamel's electron holes and show that during propagation along a positive magnetic field gradient their amplitude should grow. Neglect of energy exchange with resonant untrapped electrons would result electron hole dissipation with only modest heating factor of trapped electrons. We argue that the suggested mechanism may be responsible for generation of energetic electrons in the space plasma.

  5. Runaway electrons and ITER

    Science.gov (United States)

    Boozer, Allen H.

    2017-05-01

    The potential for damage, the magnitude of the extrapolation, and the importance of the atypical—incidents that occur once in a thousand shots—make theory and simulation essential for ensuring that relativistic runaway electrons will not prevent ITER from achieving its mission. Most of the theoretical literature on electron runaway assumes magnetic surfaces exist. ITER planning for the avoidance of halo and runaway currents is focused on massive-gas or shattered-pellet injection of impurities. In simulations of experiments, such injections lead to a rapid large-scale magnetic-surface breakup. Surface breakup, which is a magnetic reconnection, can occur on a quasi-ideal Alfvénic time scale when the resistance is sufficiently small. Nevertheless, the removal of the bulk of the poloidal flux, as in halo-current mitigation, is on a resistive time scale. The acceleration of electrons to relativistic energies requires the confinement of some tubes of magnetic flux within the plasma and a resistive time scale. The interpretation of experiments on existing tokamaks and their extrapolation to ITER should carefully distinguish confined versus unconfined magnetic field lines and quasi-ideal versus resistive evolution. The separation of quasi-ideal from resistive evolution is extremely challenging numerically, but is greatly simplified by constraints of Maxwell’s equations, and in particular those associated with magnetic helicity. The physics of electron runaway along confined magnetic field lines is clarified by relations among the poloidal flux change required for an e-fold in the number of electrons, the energy distribution of the relativistic electrons, and the number of relativistic electron strikes that can be expected in a single disruption event.

  6. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  7. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2016-05-17

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  8. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2015-12-15

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  9. Microfluidic stretchable RF electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2010-12-07

    Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

  10. Electron microscope phase enhancement

    Science.gov (United States)

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  11. Electronic Spectroscopy & Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mark Maroncelli, Nancy Ryan Gray

    2010-06-08

    The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

  12. Reversibly Bistable Flexible Electronics

    KAUST Repository

    Alfaraj, Nasir

    2015-05-01

    Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent. While maintaining large-scale production and prototyping rapidity, this flexible and translucent scheme demonstrates the potential to transform conventionally stiff electronic devices into thin and foldable ones without compromising long-term performance and reliability. In this work, we report on the fabrication and characterization of reversibly bistable flexible electronic switches that utilize flexible n-channel metal-oxide-semiconductor field-effect transistors. The transistors are fabricated initially on rigid (100) silicon substrates before they are peeled off. They can be used to control flexible batches of light-emitting diodes, demonstrating both the relative ease of scaling at minimum cost and maximum reliability and the feasibility of integration. The peeled-off silicon fabric is about 25 µm thick. The fabricated devices are transferred to a reversibly bistable flexible platform through which, for example, a flexible smartphone can be wrapped around a user’s wrist and can also be set back to its original mechanical position. Buckling and cyclic bending of such host platforms brings a completely new dimension to the development of flexible electronics, especially rollable displays.

  13. Electronic Commerce user manual

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-10

    This User Manual supports the Electronic Commerce Standard System. The Electronic Commerce Standard System is being developed for the Department of Defense of the Technology Information Systems Program at the Lawrence Livermore National Laboratory, operated by the University of California for the Department of Energy. The Electronic Commerce Standard System, or EC as it is known, provides the capability for organizations to conduct business electronically instead of through paper transactions. Electronic Commerce and Computer Aided Acquisition and Logistics Support, are two major projects under the DoD`s Corporate Information Management program, whose objective is to make DoD business transactions faster and less costly by using computer networks instead of paper forms and postage. EC runs on computers that use the UNIX operating system and provides a standard set of applications and tools that are bound together by a common command and menu system. These applications and tools may vary according to the requirements of the customer or location and may be customized to meet the specific needs of an organization. Local applications can be integrated into the menu system under the Special Databases & Applications option on the EC main menu. These local applications will be documented in the appendices of this manual. This integration capability provides users with a common environment of standard and customized applications.

  14. Electronic Commerce user manual

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-10

    This User Manual supports the Electronic Commerce Standard System. The Electronic Commerce Standard System is being developed for the Department of Defense of the Technology Information Systems Program at the Lawrence Livermore National Laboratory, operated by the University of California for the Department of Energy. The Electronic Commerce Standard System, or EC as it is known, provides the capability for organizations to conduct business electronically instead of through paper transactions. Electronic Commerce and Computer Aided Acquisition and Logistics Support, are two major projects under the DoD's Corporate Information Management program, whose objective is to make DoD business transactions faster and less costly by using computer networks instead of paper forms and postage. EC runs on computers that use the UNIX operating system and provides a standard set of applications and tools that are bound together by a common command and menu system. These applications and tools may vary according to the requirements of the customer or location and may be customized to meet the specific needs of an organization. Local applications can be integrated into the menu system under the Special Databases Applications option on the EC main menu. These local applications will be documented in the appendices of this manual. This integration capability provides users with a common environment of standard and customized applications.

  15. Pulsed electron beam precharger

    Energy Technology Data Exchange (ETDEWEB)

    Finney, W.C. (ed.); Shelton, W.N.

    1990-01-01

    Electrostatic collection of a high resistivity aerosol using the Electron Beam Precipitator (EBP) collecting section was demonstrated during this reporting period (Quarter Five). Collection efficiency experiments were designed to confirm and extend some of the work performed under the previous contract. The reason for doing this was to attempt to improve upon the collection efficiency of the precipitator alone when testing with a very high resistivity, moderate-to-high concentration dust load. From the collector shakedown runs, a set of suitable operational parameters were determined for the downstream electrostatic collecting sections of the Electron Beam Precipitator wind tunnel. These parameters, along with those for the MINACC electron beam, will generally be held constant while the numerous precharging parameters are varied to produce an optimum particle charge. The electrostatic collector experiments were part of a larger, comprehensive investigation on electron beam precharging of high resistivity aerosol particles performed during the period covered by Quarters Five, Six, and Seven. This body of work used the same experimental apparatus and procedures and the experimental run period lasted nearly continuously for six months. A summary of the Quarter Five work is presented in the following paragraphs. Section II-A of TPR 5 contains a report on the continuing effort which was expended on the modification and upgrade of the pulsed power supply and the monitoring systems prior to the initiation of the electron beam precharging experimental work.

  16. Electron correlation in beryllium

    DEFF Research Database (Denmark)

    Omiste, Juan J.; Li, Wenliang; Madsen, Lars Bojer

    2017-01-01

    We apply a three-dimensional implementation of the time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method to investigate effects of electron correlation in the ground state of Be as well as in its photoionization dynamics by short XUV pulses, including time delay in photo......We apply a three-dimensional implementation of the time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method to investigate effects of electron correlation in the ground state of Be as well as in its photoionization dynamics by short XUV pulses, including time delay...... schemes, and in this way we identify the orbital spaces that are relevant for an accurate description of the photoelectron spectra. Finally, we investigate the effects of electron correlation on the magnitude of the relative Eisenbud-Wigner-Smith (EWS) time delay in the photoionization process into two...... different ionic channels. One channel, the ground-state channel in the ion, is accessible without electron correlation. The other channel is only accessible when including electron correlation. For theory beyond the mean-field time-dependent Hartree-Fock, the EWS time delay for the photon energy analyzed...

  17. Electronic Submissions of Pesticide Applications

    Science.gov (United States)

    Applications for pesticide registration can be submitted electronically, including forms, studies, and draft product labeling. Applicants need not submit multiple electronic copies of any pieces of their applications.

  18. Phasor power electronics

    CERN Document Server

    Rim, Chun T

    2016-01-01

    This book presents a comprehensive introduction to the principles of power electronics, focusing on the switched transformer concept and phasor transformation techniques as employed in the analysis and design of power electronic circuits. Phasor transformations, as introduced in this book, make the time-varying nature of a switching converter simple and easy to handle, transforming it into an equivalent time-invariant circuit. The book starts with an introduction to the philosophy and fundamental principles of power electronics. The switched transformer concept, which is applicable to any switching converter, is introduced, and it is shown how DC-DC converters analyses are then so straightforward that very little equational manipulation is needed. Then the phasor transformation techniques are comprehensively explained over three parts. Single phase and multi-phase AC systems are dealt with through the single phase phasor transformation and circuit DQ transformation, respectively. A general unified phasor tran...

  19. Understanding the Electron

    CERN Document Server

    Knuth, Kevin H

    2015-01-01

    Well over a century after the discovery of the electron, we are still faced with serious conceptual issues regarding precisely what an electron is. Since the development of particle physics and the Standard Model, we have accumulated a great deal of knowledge about the relationships among various subatomic particles. However, this knowledge has not significantly aided in our understanding of the fundamental nature of any particular elementary subatomic particle. The fact that many particle properties, such as position, time, speed, energy, momentum, and component of spin, are observer-dependent suggests that these relevant variables do not represent properties per se, but rather the relationship between the observer and the observed. That is, they reflect details about how the electron influences the observer, and vice versa. Here we attempt to understand this by considering a simple model where particles influence one another in a discrete and direct fashion. The resulting framework, referred to as Influence...

  20. On Zitterbewegung of Electron

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-yong; XIONG Cai-dong; ZHOU Ping

    2005-01-01

    Traditionally, all the discussions on zitterbewegung (zbw) of electron are based on relativistic quantum mechanics. In this article, from the viewpoint of quantum field theory and in terms of the creation and annihilation operators as well as the polarization vectors of spin-1 field, a more detailed description and some new perspectives for zbw are obtained. Especially, it is shown that zbw arises from a to-and-fro vacuum polarization that occurring in the neighborhood of electron; the zbw vectors form a vector triplet with total spin projections 0 and ±1 in the direction of the momentum of electron, respectively; the macroscopic velocity of the vacuum medium vanishes in all inertial systems.

  1. Electronic apex locators.

    Science.gov (United States)

    Gordon, M P J; Chandler, N P

    2004-07-01

    Prior to root canal treatment at least one undistorted radiograph is required to assess canal morphology. The apical extent of instrumentation and the final root filling have a role in treatment success, and are primarily determined radiographically. Electronic apex locators reduce the number of radiographs required and assist where radiographic methods create difficulty. They may also indicate cases where the apical foramen is some distance from the radiographic apex. Other roles include the detection of root canal perforation. A review of the literature focussed first on the subject of electronic apex location. A second review used the names of apex location devices. From the combined searches, 113 pertinent articles in English were found. This paper reviews the development, action, use and types of electronic apex locators.

  2. Electron Technology: ELTE 2016

    Science.gov (United States)

    Pisarkiewicz, Tadeusz; Kucewicz, Wojciech

    2016-12-01

    In this paper we present a review of research results and technical accomplishments presented by researchers from technical universities, governmental institutes and research companies during the XIIth Scientific Conference Electron Technology, ELTE 2016. This review is based on materials presented at four topical conference sessions: Microelectronics and Nanoelectronics, Photonics, Materials and Technologies, and Microsystems and also on materials presented by invited speakers at two dedicated sessions. Oral sessions were accompanied by the poster sessions. In effect about 50 papers gathered in this volume reflect the topics discussed at the Conference. A short description of technological and measurement possibilities in the laboratories of Academic Centre for Materials and Nanotechnology and also in the Department of Electronics of the Faculty of Computer Science, Electronics and Telecommunications AGH UST are given.

  3. Microelectronics improves power electronics

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, R.

    1982-07-01

    The share of electric energy consumed by electric drives - called power current - can be used more efficiently by using power electronic regulating processes. Lower cost for power electronic components and progress in circuit technology are the decisive factors for the widespread use of regulating units. Microelectronics permit a cost-beneficial control of power regulating units, are made them more attractive for the user. Technical and economic attractivity of power electronic regulating processes have increased. These processes are mainly used for adjusting engine speed to the other process engineering parameters like pressure, output or speed. Optimization of power-current consuming processes are expected to achieve an energy saving potential of 15 TWh by the year 1995.

  4. 4D Electron Tomography

    Science.gov (United States)

    Kwon, Oh-Hoon; Zewail, Ahmed H.

    2010-06-01

    Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a movie of the object in motion, thus enabling studies of nonequilibrium structures and transient processes. The method was demonstrated using carbon nanotubes of a bracelet-like ring structure for which 4D tomograms display different modes of motion, such as breathing and wiggling, with resonance frequencies up to 30 megahertz. Applications can now make use of the full space-time range with the nanometer-femtosecond resolution of ultrafast electron tomography.

  5. Electronic network links physicists

    Science.gov (United States)

    Now that AGU is a member of the American Institute of Physics (AIP) (see item on page 150), AGU members may access Pi-NET, the Physics Information Network developed by AIP on behalf of its member societies. The electronic network will be available after March 31, 1986, to members of AIP member and affiliate societies for the cost of a local telephone call.This electronic database service provides listings of job opportunities in physics, calendars of meetings, advance abstracts of more than 40 journals published by AIP and member societies, brief announcements and news items, titles of journal articles from AIP's Searchable Physics Information Notices (SPIN) database, and an electronic catalog and on-line ordering of publications from AIP and member societies. AGU journals will be included in the database shortly.

  6. Laser assisted electron dynamics

    CERN Document Server

    Bray, Alexander William

    2016-01-01

    We apply the convergent close-coupling (CCC) formalism to analyse the processes of laser assisted electron impact ionisation of He, and the attosecond time delay in the photodetachment of the H^{-} ion and the photoionisation of He. Such time dependent atomic collision processes are of considerable interest as experimental measurements on the relevant timescale (attoseconds 10^{-18} s) are now possible utilising ultrafast and intense laser pulses. These processes in particular are furthermore of interest as they are strongly influenced by many-electron correlations. In such cases their theoretical description requires a more comprehensive treatment than that offered by first order perturbation theory. We apply such a treatment through the use of the CCC formalism which involves the complete numeric solution of the integral Lippmann-Schwinger equations pertaining to a particular scattering event. For laser assisted electron impact ionisation of He such a treatment is of a considerably greater accuracy than the...

  7. Relativistic Runaway Electrons

    Science.gov (United States)

    Breizman, Boris

    2014-10-01

    This talk covers recent developments in the theory of runaway electrons in a tokamak with an emphasis on highly relativistic electrons produced via the avalanche mechanism. The rapidly growing population of runaway electrons can quickly replace a large part of the initial current carried by the bulk plasma electrons. The magnetic energy associated with this current is typically much greater than the particle kinetic energy. The current of a highly relativistic runaway beam is insensitive to the particle energy, which separates the description of the runaway current evolution from the description of the runaway energy spectrum. A strongly anisotropic distribution of fast electrons is generally prone to high-frequency kinetic instabilities that may cause beneficial enhancement of runaway energy losses. The relevant instabilities are in the frequency range of whistler waves and electron plasma waves. The instability thresholds reported in earlier work have been revised considerably to reflect strong dependence of collisional damping on the wave frequency and the role of plasma non-uniformity, including radial trapping of the excited waves in the plasma. The talk also includes a discussion of enhanced scattering of the runaways as well as the combined effect of enhanced scattering and synchrotron radiation. A noteworthy feature of the avalanche-produced runaway current is a self-sustained regime of marginal criticality: the inductive electric field has to be close to its critical value (representing avalanche threshold) at every location where the runaway current density is finite, and the current density should vanish at any point where the electric field drops below its critical value. This nonlinear Ohm's law enables complete description of the evolving current profile. Work supported by the U.S. Department of Energy Contract No. DEFG02-04ER54742 and by ITER contract ITER-CT-12-4300000273. The views and opinions expressed herein do not necessarily reflect those of

  8. Electron-electron correlations in liquid s-p metals

    CERN Document Server

    Leys, F E

    2003-01-01

    We present calculations for the valence electron-electron structure factor in liquid Mg near freezing, assuming knowledge of the jellium result. On the basis of this, we predict significant corrections to jellium short-range correlations in liquid s-p metals and in particular an increase in the electron-electron contact probability.

  9. Electron kinetics in capacitively coupled plasmas modulated by electron injection

    Science.gov (United States)

    Zhang, Ya; Peng, Yanli; Innocenti, Maria Elena; Jiang, Wei; Wang, Hong-yu; Lapenta, Giovanni

    2017-09-01

    The controlling effect of an electron injection on the electron energy distribution function (EEDF) and on the energetic electron flux, in a capacitive radio-frequency argon plasma, is studied using a one-dimensional particle-in-cell/Monte Carlo collisions model. The input power of the electron beam is as small as several tens of Watts with laboratory achievable emission currents and energies. With the electron injection, the electron temperature decreases but with a significant high energy tail. The electron density, electron temperature in the sheath, and electron heating rate increase with the increasing emission energy. This is attributed to the extra heating of the energetic electrons in the EEDF tail. The non-equilibrium EEDF is obtained for strong non-local distributions of the electric field, electron heating rate, excitation, and ionization rate, indicating the discharge has transited from a volume heating (α-mode dominated) into a sheath heating (γ-mode dominated) type. In addition, the electron injection not only modifies the self-bias voltage, but also enhances the electron flux that can reach the electrodes. Moreover, the relative population of energetic electrons significantly increases with the electron injection compared to that without the electron injection, relevant for modifying the gas and surface chemistry reactions.

  10. Advances in quantum electronics

    CERN Document Server

    Goodwin, D W

    1974-01-01

    Advances in Quantum Electronics, Volume 2 deals with the effects of quantum mechanics on the behavior of electrons in matter. This book is divided into three chapters. Chapter 1 reviews the statistical properties of optical fields and spectral processing techniques, including the use of photon correlation techniques to measure scattering effects in a number of different media. The use of optical E.P.R. and excitation spectroscopic techniques and techniques for establishing the location of impurity ions in the chalcogenides are describe in Chapter 2. The last chapter surveys the field of mode l

  11. Recycling of electronic scrap

    DEFF Research Database (Denmark)

    Legarth, Jens Brøbech

    This Ph.D. thesis deals with the growingly important field of electronics recycling with special attention to the problem of printed circuit board recycling. A literature survey of contemporary electronics recycling and printed circuit board recycling is presented.Further, an analysis of the role...... in the metals producing industry is presented and tested on two printed circuit board scrap cases. The underlying idea for the method is that complex scrap should be introduced in the matrix of man-made material flows at recipient points where the scrap constitutes the least environmental problem and where...

  12. Advances in electronic materials

    CERN Document Server

    Kasper, Erich; Grimmeiss, Hermann G

    2008-01-01

    This special-topic volume, Advances in Electronic Materials, covers various fields of materials research such as silicon, silicon-germanium hetero-structures, high-k materials, III-V semiconductor alloys and organic materials, as well as nano-structures for spintronics and photovoltaics. It begins with a brief summary of the formative years of microelectronics; now the keystone of information technology. The latter remains one of the most important global technologies, and is an extremely complex subject-area. Although electronic materials are primarily associated with computers, the internet

  13. Electronically configured battery pack

    Energy Technology Data Exchange (ETDEWEB)

    Kemper, D.

    1997-03-01

    Battery packs for portable equipment must sometimes accommodate conflicting requirements to meet application needs. An electronically configurable battery pack was developed to support two highly different operating modes, one requiring very low power consumption at a low voltage and the other requiring high power consumption at a higher voltage. The configurable battery pack optimizes the lifetime and performance of the system by making the best use of all available energy thus enabling the system to meet its goals of operation, volume, and lifetime. This paper describes the cell chemistry chosen, the battery pack electronics, and tradeoffs made during the evolution of its design.

  14. Conventional transmission electron microscopy.

    Science.gov (United States)

    Winey, Mark; Meehl, Janet B; O'Toole, Eileen T; Giddings, Thomas H

    2014-02-01

    Researchers have used transmission electron microscopy (TEM) to make contributions to cell biology for well over 50 years, and TEM continues to be an important technology in our field. We briefly present for the neophyte the components of a TEM-based study, beginning with sample preparation through imaging of the samples. We point out the limitations of TEM and issues to be considered during experimental design. Advanced electron microscopy techniques are listed as well. Finally, we point potential new users of TEM to resources to help launch their project.

  15. Electronics for technicians

    CERN Document Server

    Crane, P W

    2013-01-01

    Electronics for Technicians covers the basic fundamentals of electronics, including the operation of devices and circuits. The book is meant to help the technician to obtain numerical answers to actual circuit problems. This volume consists of seven chapters, the first of which introduces the reader to the basic rules for circuits containing resistive and reactive elements. Charge and discharge of a capacitor through a resistor is discussed, along with charge and discharge of an inductance through a resistance, application of sinusoidal voltages to simple networks, and series and parallel LCR

  16. Precision electron polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chudakov, E. [Jefferson Lab 12000 Jefferson Ave, STE 16, Newport News, VA 23606 (United States)

    2013-11-07

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. Mo/ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at 300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100%-polarized electron target for Mo/ller polarimetry.

  17. Pulsed Electron Holography

    CERN Document Server

    Germann, Matthias; Escher, Conrad; Fink, Hans-Werner

    2013-01-01

    A technique of pulsed low-energy electron holography is introduced that allows for recording highly resolved holograms within reduced exposure times. Therefore, stacks of holograms are accumulated in a pulsed mode with individual acquisition times as short as 50 {\\mu}s. Subsequently, these holograms are aligned and finally superimposed. The resulting holographic record reveals previously latent high-order interference fringes and thereby pushing interference resolution into the sub-nanometer regime. In view of the non-damaging character of low-energy electrons, the method is of particular interest for structural analysis of fragile biomolecules.

  18. Electronics 2 checkbook

    CERN Document Server

    Knight, S A

    2013-01-01

    Electronics 2 Checkbook is an 11-chapter text that presents problems and worked examples to establish and exemplify the theory contained in technical syllabuses, with a particular emphasis on electronics.The introductory chapters review the elementary theory of semiconductors and the p-n junction diode. The subsequent chapters deal with the applications of diode, the characteristics of bipolar transistors, and the mode of operation of small signal amplifiers. These topics are followed by discussions of the function of the field-effect transistor and power supplies. The concluding chapters expl

  19. VLSI electronics microstructure science

    CERN Document Server

    1981-01-01

    VLSI Electronics: Microstructure Science, Volume 3 evaluates trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the impact of VLSI on computer architectures; VLSI design and design aid requirements; and design, fabrication, and performance of CCD imagers. The approaches, potential, and progress of ultra-high-speed GaAs VLSI; computer modeling of MOSFETs; and numerical physics of micron-length and submicron-length semiconductor devices are also elaborated. This text likewise covers the optical linewi

  20. Electronic Word of Behavior

    DEFF Research Database (Denmark)

    Kunst, Katrine

    It is widely recognized that the transition from Word-of-mouth (WOM) to electronic word-of-mouth (eWOM) allows for a wider and faster spread of information. However, little attention has been given to how digital channels expand the types of information consumers share. In this paper, we argue...... of the concepts do not capture this new kind of consumer-to-consumer information transfer about products and services. Consequently, we suggest an extension of those concepts: Electronic Word of Behavior....

  1. Modern electronic maintenance principles

    CERN Document Server

    Garland, DJ

    2013-01-01

    Modern Electronic Maintenance Principles reviews the principles of maintaining modern, complex electronic equipment, with emphasis on preventive and corrective maintenance. Unfamiliar subjects such as the half-split method of fault location, functional diagrams, and fault finding guides are explained. This book consists of 12 chapters and begins by stressing the need for maintenance principles and discussing the problem of complexity as well as the requirements for a maintenance technician. The next chapter deals with the connection between reliability and maintenance and defines the terms fai

  2. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    1988-01-01

    Practical Electronics Handbook, Second Edition covers information useful in electronics, with focus on mathematical conventions. The handbook discusses the passive (resistors, capacitors, band coding, and inductors) and active discrete (diodes, transistors and negative feedback) components; discrete component circuits; and transferring digital data. Linear I.C.s, which are the single-chip arrangements of amplifier circuits that are intended to be biased and operated in a linear way, and digital I.C.s, which process signals and consist of two significant voltage levels, are also considered. T

  3. Gallium nitride electronics

    Science.gov (United States)

    Rajan, Siddharth; Jena, Debdeep

    2013-07-01

    In the past two decades, there has been increasing research and industrial activity in the area of gallium nitride (GaN) electronics, stimulated first by the successful demonstration of GaN LEDs. While the promise of wide band gap semiconductors for power electronics was recognized many years before this by one of the contributors to this issue (J Baliga), the success in the area of LEDs acted as a catalyst. It set the field of GaN electronics in motion, and today the technology is improving the performance of several applications including RF cell phone base stations and military radar. GaN could also play a very important role in reducing worldwide energy consumption by enabling high efficiency compact power converters operating at high voltages and lower frequencies. While GaN electronics is a rapidly evolving area with active research worldwide, this special issue provides an opportunity to capture some of the great advances that have been made in the last 15 years. The issue begins with a section on epitaxy and processing, followed by an overview of high-frequency HEMTs, which have been the most commercially successful application of III-nitride electronics to date. This is followed by review and research articles on power-switching transistors, which are currently of great interest to the III-nitride community. A section of this issue is devoted to the reliability of III-nitride devices, an area that is of increasing significance as the research focus has moved from not just high performance but also production-worthiness and long-term usage of these devices. Finally, a group of papers on new and relatively less studied ideas for III-nitride electronics, such as interband tunneling, heterojunction bipolar transistors, and high-temperature electronics is included. These areas point to new areas of research and technological innovation going beyond the state of the art into the future. We hope that the breadth and quality of articles in this issue will make it

  4. Electronics made simple

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics: Made Simple covers the fundamental principles, basic devices, characteristics, and application of electronic equipment.This book is divided into 15 chapters and begins with reviews of the properties and behavior of resistors, capacitors, inductors, and semiconductor devices. Considerable chapters deal with how these devices can be assembled into useful fundamental circuits such as amplifiers, oscillators and power supplies. These topics are followed by discussions of the importance of integrated circuits and the use of digital equipment and photocells in control and computing appa

  5. Electronic components and technology

    CERN Document Server

    Sangwine, Stephen

    2007-01-01

    Most introductory textbooks in electronics focus on the theory while leaving the practical aspects to be covered in laboratory courses. However, the sooner such matters are introduced, the better able students will be to include such important concerns as parasitic effects and reliability at the very earliest stages of design. This philosophy has kept Electronic Components and Technology thriving for two decades, and this completely updated third edition continues the approach with a more international outlook.Not only does this textbook introduce the properties, behavior, fabrication, and use

  6. Nanotube electronics and optoelectronics

    Directory of Open Access Journals (Sweden)

    Phaedon Avouris

    2006-10-01

    Full Text Available Among the many materials that have been proposed to supplement and, in the long run, possibly succeed Si as a basis for nanoelectronics, carbon nanotubes (CNTs have attracted the most attention. CNTs are quasi-one-dimensional materials with unique properties ideally suited for electronics. We briefly discuss the electrical and optical properties of CNTs and how they can be employed in electronics and optoelectronics. We focus on single CNT transistors, their fabrication, assembly, doping, electrical characteristics, and integration. We also address the possible use of CNTs in optoelectronic devices such as electroluminescent light emitters and photodetectors.

  7. Relativistic electronic dressing

    CERN Document Server

    Attaourti, Y

    2002-01-01

    We study the effects of the relativistic electronic dressing in laser-assisted electron-hydrogen atom elastic collisions. We begin by considering the case when no radiation is present. This is necessary in order to check the consistency of our calculations and we then carry out the calculations using the relativistic Dirac-Volkov states. It turns out that a simple formal analogy links the analytical expressions of the differential cross section without laser and the differential cross section in presence of a laser field.

  8. Diagnostic electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dickersin, G.R.

    1988-01-01

    In this book the author presents a comprehensive reference text on diagnostic electron microscopy. Throughout the book he illustrates how ultrastructural identification can be helpful for the recognition of cell type and the identification of mechanisms of pathogenesis in various diseases. In addition to electron microscopy photographs, there are also numerous light microscopy photographs for comparison. This text presents the classification of neoplasms in the order and arrangement most familiar to the pathologist. Contents: Introduction; Diagram of a Normal Cell; Normal Cell Function; Embryology; Neoplasms; Infectious Agents; Metabolic Diseases; Renal Diseases; Skeletal Muscle and Peripheral Nerve Diseases; Index.

  9. Electronic logic circuits

    CERN Document Server

    Gibson, J

    2013-01-01

    Most branches of organizing utilize digital electronic systems. This book introduces the design of such systems using basic logic elements as the components. The material is presented in a straightforward manner suitable for students of electronic engineering and computer science. The book is also of use to engineers in related disciplines who require a clear introduction to logic circuits. This third edition has been revised to encompass the most recent advances in technology as well as the latest trends in components and notation. It includes a wide coverage of application specific integrate

  10. Precision electron polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chudakov, Eugene A. [JLAB

    2013-11-01

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. M{\\o}ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at ~300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100\\%-polarized electron target for M{\\o}ller polarimetry.

  11. Improved electron transport layer

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides: a method of preparing a coating ink for forming a zinc oxide electron transport layer, comprising mixing zinc acetate and a wetting agent in water or methanol; a coating ink comprising zinc acetate and a wetting agent in aqueous solution or methanolic solution...

  12. Using Electronic Portfolios

    Science.gov (United States)

    Page, Deb

    2012-01-01

    The digitized collections of artifacts known as electronic portfolios are creating solutions to a variety of performance improvement needs in ways that are cost-effective and improve both individual and group learning and performance. When social media functionality is embedded in e-portfolios, the tools support collaboration, social learning,…

  13. Quantitative Electron Nanodiffraction.

    Energy Technology Data Exchange (ETDEWEB)

    Spence, John [Arizona State Univ., Mesa, AZ (United States)

    2015-01-30

    This Final report summarizes progress under this award for the final reporting period 2002 - 2013 in our development of quantitive electron nanodiffraction to materials problems, especially devoted to atomistic processes in semiconductors and electronic oxides such as the new artificial oxide multilayers, where our microdiffraction is complemented with energy-loss spectroscopy (ELNES) and aberration-corrected STEM imaging (9). The method has also been used to map out the chemical bonds in the important GaN semiconductor (1) used for solid state lighting, and to understand the effects of stacking sequence variations and interfaces in digital oxide superlattices (8). Other projects include the development of a laser-beam Zernike phase plate for cryo-electron microscopy (5) (based on the Kapitza-Dirac effect), work on reconstruction of molecular images using the scattering from many identical molecules lying in random orientations (4), a review article on space-group determination for the International Tables on Crystallography (10), the observation of energy-loss spectra with millivolt energy resolution and sub-nanometer spatial resolution from individual point defects in an alkali halide, a review article for the Centenary of X-ray Diffration (17) and the development of a new method of electron-beam lithography (12). We briefly summarize here the work on GaN, on oxide superlattice ELNES, and on lithography by STEM.

  14. Inventing the Electronic University

    Science.gov (United States)

    Lewis, David W.

    2015-01-01

    Higher education is confronting a fundamental change. The transition from print on paper to digital and electronic technologies is transforming instruction, scholarly communication, and the storage and preservation of knowledge. What is required is not the automation of old systems, but the restructuring of institutions. The drive for autonomy,…

  15. Power Electronics Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-07

    Thermal modeling was conducted to evaluate and develop thermal management strategies for high-temperature wide-bandgap (WBG)-based power electronics systems. WBG device temperatures of 175 degrees C to 250 degrees C were modeled under various under-hood temperature environments. Modeling result were used to identify the most effective capacitor cooling strategies under high device temperature conditions.

  16. Polymer Electronics, Quo Vadis?

    NARCIS (Netherlands)

    Chiechi, Ryan C.; Hummelen, Jan C.

    2012-01-01

    At the heart of polymer electronics lies more than three decades of research into conjugated polymers. The future of these materials is intimately tied to the development of organic photovoltaic (OPV) devices that can compete with traditional, inorganic devices in efficiency and cost. In addition to

  17. Polymer Electronics, Quo Vadis?

    NARCIS (Netherlands)

    Chiechi, Ryan C.; Hummelen, Jan C.

    2012-01-01

    At the heart of polymer electronics lies more than three decades of research into conjugated polymers. The future of these materials is intimately tied to the development of organic photovoltaic (OPV) devices that can compete with traditional, inorganic devices in efficiency and cost. In addition to

  18. Electronic Inspection of Beef

    Science.gov (United States)

    Anselmo, Victor J.; Gammell, Paul M.; Clark, Jerry

    1987-01-01

    Two proposed methods for grading beef quality based on inspection by electronic equipment: one method uses television camera to generate image of a cut of beef as customer sees it; other uses ultrasonics to inspect live animal or unsliced carcasses. Both methods show promise for automated meat inspection.

  19. The electronic stethoscope.

    Science.gov (United States)

    Leng, Shuang; Tan, Ru San; Chai, Kevin Tshun Chuan; Wang, Chao; Ghista, Dhanjoo; Zhong, Liang

    2015-07-10

    Most heart diseases are associated with and reflected by the sounds that the heart produces. Heart auscultation, defined as listening to the heart sound, has been a very important method for the early diagnosis of cardiac dysfunction. Traditional auscultation requires substantial clinical experience and good listening skills. The emergence of the electronic stethoscope has paved the way for a new field of computer-aided auscultation. This article provides an in-depth study of (1) the electronic stethoscope technology, and (2) the methodology for diagnosis of cardiac disorders based on computer-aided auscultation. The paper is based on a comprehensive review of (1) literature articles, (2) market (state-of-the-art) products, and (3) smartphone stethoscope apps. It covers in depth every key component of the computer-aided system with electronic stethoscope, from sensor design, front-end circuitry, denoising algorithm, heart sound segmentation, to the final machine learning techniques. Our intent is to provide an informative and illustrative presentation of the electronic stethoscope, which is valuable and beneficial to academics, researchers and engineers in the technical field, as well as to medical professionals to facilitate its use clinically. The paper provides the technological and medical basis for the development and commercialization of a real-time integrated heart sound detection, acquisition and quantification system.

  20. The Art of Electronics

    Science.gov (United States)

    Horowitz, Paul; Hill, Winfield

    2015-04-01

    1. Foundations; 2. Bipolar transistors; 3. Field effect transistors; 4. Operational amplifiers; 5. Precision circuits; 6. Filters; 7. Oscillators and timers; 8. Low noise techniques and transimpedance; 9. Power regulation; 10. Digital electronics; 11. Programmable logic devices; 12. Logical interfacing; 13. Digital meets analog; 14. Computers, controllers, and data links; 15. Microcontrollers.

  1. Unconditionally Secure Electronic Voting

    Science.gov (United States)

    Otsuka, Akira; Imai, Hideki

    In this chapter, we will show how to achieve unconditional or information-theoretic security in electronic voting with the following property: 1 Even all voters and tallying authorities have unbounded computing power, the distorted integrity of the voting results can be detected and proved incorrect by every honest voter,

  2. Electronic waste recycling techniques

    CERN Document Server

    Bernardes, Andréa

    2015-01-01

    This book presents an overview of the characterization of electronic waste. In addition, processing techniques for the recovery of metals, polymers and ceramics are described. This book serves as a source of information and as an educational technical reference for practicing scientists and engineers, as well as for students.

  3. Using Electronic Portfolios

    Science.gov (United States)

    Page, Deb

    2012-01-01

    The digitized collections of artifacts known as electronic portfolios are creating solutions to a variety of performance improvement needs in ways that are cost-effective and improve both individual and group learning and performance. When social media functionality is embedded in e-portfolios, the tools support collaboration, social learning,…

  4. Electron microscope studies

    Energy Technology Data Exchange (ETDEWEB)

    Crewe, A.V.; Kapp, O.H.

    1990-08-01

    Our laboratory has made significant progress this year in devising improved electron-optical systems, in studying invertebrate hemoglobins with the STEM, and in achieving a workable sub-angstrom STEM. Our goal in electron optics is to improve resolution by producing spherical and chromatic aberration coefficients with signs opposite those of magnetic lenses. We have progressed toward this goal through calculations that explore the addition of electrodes to electron mirrors to reduce these two geometric aberrations and by devising a beam separation system that won't introduce asymmetrical aberrations. Some promising new designs of magnetic lenses for SEM applications have also been investigated. We have continued our exploration of the quaternary structure of the invertebrate hemoglobins and are now among the top laboratories in this area of expertise. In addition, we have overcome many of our electronic difficulties on the sub-angstrom STEM and have made significant progress toward achieving an operational system. The addition of an IBM RISC-6000 workstation to our lab has significantly increased our image processing capabilities.

  5. The Electronic Student Portfolio.

    Science.gov (United States)

    Fasick, Emily; McLaren, Clemence

    1995-01-01

    Describes the use of electronic portfolios in one Hawaiian secondary literature class. Students went through their journals, picked two entries that best represented their growth in reading during the course, and explained why. Next they created a presentation about their growth and enjoyment of literature using multimedia technology. (SM)

  6. Electronic and Microelectronic Capabilities.

    Science.gov (United States)

    1982-07-01

    22 3.9 Aztec Products Custom Wet-Chemistry Line ........................................... 22 3.10 KotIrnorgen...Cofight Vertical Rotary Etcher............*....................................................... 22 11. Aztec Products Custom Wet-Chemistry Line...state of the art in thick film hybrid fabrication methods, microelectronic fabrication and assembly, PC board fabrication, and electronic board assembly

  7. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  8. Selection of Electronic Resources.

    Science.gov (United States)

    Weathers, Barbara

    1998-01-01

    Discusses the impact of electronic resources on collection development; selection of CD-ROMs, (platform, speed, video and sound, networking capability, installation and maintenance); selection of laser disks; and Internet evaluation (accuracy of content, authority, objectivity, currency, technical characteristics). Lists Web sites for evaluating…

  9. Electron-Cyclotron Waves

    NARCIS (Netherlands)

    Westerhof, E.

    1994-01-01

    The essential elements of the theory of electron cyclotron waves are reviewed, The two main electro-magnetic modes of propagation are identified and their dispersion and absorption properties are discussed. The importance of the use of the relativistic resonance condition is stressed.

  10. Advanced Electronic Technology.

    Science.gov (United States)

    1980-05-15

    Silicon De- D.,I. Silversmith Solid State Technol. 23, 88 vices Formed by Ion Iniplanta- 1. W. Mountain (1980) tion and Laser Annealing S.C. Munroe M...J. Silversmith Photodeposition R. M. Osgood, Jr. 5075 Picosecond Optical Sampling H. A. Haus* Accepted by IEEE J. Quantum S.T. Kirsch Electron. K

  11. Cold electronics: an overview

    Science.gov (United States)

    Kirschman, R. K.

    Low-temperature operation is being applied and contemplated for electronic systems ranging from single-transistor circuits for basic research to VLSI integrated circuits for ultra-fast computers. It is seen as both a means of extracting better performance from present technology and as an important ingredient of the next generation of devices and circuits. This overview is concerned with electronics based on semiconductors; for low temperatures the primary material is Si, although GaAs also has considerable potential, and the primary device is the field-effect transistor in various forms. Reduced temperature operation offers improvements in performance through improvement of materials-related properties such as electronic carrier mobility, thermal conductivity, and electrical conductivity. Substantial improvements in reliability are also expected since degradation mechanisms are thermally activated; however, this could be negated unless problems of thermal expansion mismatch and cycling are overcome. Refrigeration continues to be a central concern; mechanical cycles are still the mainstay and progress is being made in systems applicable to electronics, although further development is needed.

  12. The Electronic Battle Box

    Science.gov (United States)

    Gouin, Denis; Turcotte, Guy; Lebel, Eric; Gilbert, Annie

    2000-08-01

    The Electronic Battle Box is an integrated suite of planning and decision-aid tools specially designed to facilitate Canadian Armed Force Officers during their training and during their tasks of preparing and conducting military operations. It is the result of a collaborative effort between the Defence Research Establishment Valcartier, the Directorate of Army Doctrine (DAD), the Directorate of Land Requirements (DLR), the G4 staff of 1Cdn Div HQ and CGI Information and Management Consultants Inc. Distributed on CD-ROM, the Electronic Battle Box contains efficient and user-friendly tools that significantly reduce the planning time for military operations and ensure staff officers a better focus on significant tasks. Among the tools are an OrBat Browser and an Equipment Browser allowing to view and edit military organizations, a Task Browser providing facilities to prepare plans using Gantt charts, a Logistic Planner allowing to estimate supply requirements applying complex calculations, and Road, Air and Rail Movement Planners. EBB also provides staff officers with a large set of doctrinal documents in an electronic format. This paper provides an overview of the various tools of the Electronic Battle Box.

  13. The electronic neighbourhood

    DEFF Research Database (Denmark)

    Rüdiger, Bjarne; Tournay, Bruno

    2004-01-01

    This paper presents the results of a 3-year research project. The Electronic Neighbourhood (2000-2004). Researchers have developed and tested a digital model of the urban area and other digital tools for supporting the dialogue and cooperation between professionals and citizens in an urban...... regeneration project in Copenhagen....

  14. Electronics and Electromagnetism

    Science.gov (United States)

    Nièpce, J.-C.; Givord, D.

    Multilayer ceramic capacitors (MLCC) are the capacitors most commonly used in electronic circuits (television, radio, telephone, automobile, aeronautics, space, etc.). The main advantages are low cost, small size, a good level of chemical inertness, due to the fact that they are made from chemically very stable oxide ceramics, and hence good stability in time.

  15. ELECTRON COOLING FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.

    2001-05-13

    The Accelerator Collider Department (CAD) at Brookhaven National Laboratory is operating the Relativistic Heavy Ion Collider (RHIC), which includes the dual-ring, 3.834 km circumference superconducting collider and the venerable AGS as the last part of the RHIC injection chain. CAD is planning on a luminosity upgrade of the machine under the designation RHIC II. One important component of the RHIC II upgrade is electron cooling of RHIC gold ion beams. For this purpose, BNL and the Budker Institute of Nuclear Physics in Novosibirsk entered into a collaboration aimed initially at the development of the electron cooling conceptual design, resolution of technical issues, and finally extend the collaboration towards the construction and commissioning of the cooler. Many of the results presented in this paper are derived from the Electron Cooling for RHIC Design Report [1], produced by the, BINP team within the framework of this collaboration. BNL is also collaborating with Fermi National Laboratory, Thomas Jefferson National Accelerator Facility and the University of Indiana on various aspects of electron cooling.

  16. Active devices for electronics

    CERN Document Server

    Sowa, Walter A

    1971-01-01

    An introduction to semiconductors ; the p-n junction ; the junction transistor ; electrical characteristics and ratings ; basic transistor amplifiers ; the field-effect transistor ; the unijunction transistor (UJT) ; the silicon controlled rectifier (SCR) ; the DIAC and TRIAC ; light operated devices ; integrated circuits (ICs) ; other solid-state devices of interest ; electron tubes.

  17. Nucleus Driven Electronic Pulsation

    CERN Document Server

    Ludwig, H; Xue, S -S

    2014-01-01

    We derive and solve by the spectral method the equations for a neutral system of ultra-relativistic electrons that are compressed to the radius of the nucleus and subject to a driving force. This driving force can be thought of as originating from a nuclear breathing mode, a possibility we discuss in detail.

  18. Electronically Enhanced Classroom Interaction.

    Science.gov (United States)

    Draper, Stephen; Cargill, Julie; Cutts, Quintin

    A design rationale for introducing electronic equipment (a group response system) for student interaction in lecture theaters is presented, linking the instructional design to theory. The effectiveness of the equipment for learning depends mostly on what pedagogic method is employed. Various alternative types are introduced, including: assessment;…

  19. Adaptive municipal electronic forms

    NARCIS (Netherlands)

    Kuiper, Pieter; Dijk, van Betsy; Bondarouk, Tanya; Ruël, Huub; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    2009-01-01

    Adaptation of electronic forms (e-forms) seems to be a step forward to reduce the burden for people who fill in forms. Municipalities more and more offer e-forms online that can be used by citizens to request a municipal product or service or by municipal employees to place a request on behalf of a

  20. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  1. Newnes electronics assembly pocket book

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Produced in association with the Engineering Training Authority with contributions from dozens of people in the electronics industry. The material covers common skills in electrical and electronic engineering and concentrates mainly on wiring and assembly. 'Newnes Electronics Assembly Pocket Book' is for electronics technicians, students and apprentices.

  2. Electronic Library: A TERI Experiment.

    Science.gov (United States)

    Kar, Debal C.; Deb, Subrata; Kumar, Satish

    2003-01-01

    Discusses the development of Electronic Library at TERI (The Energy and Resources Institute, New Delhi). Highlights include: hardware and software used; the digital library/Virtual Electronic Library; directory of Internet journals; virtual reference resources; electronic collection/Physical Electronic Library; downloaded online full-length…

  3. The electronic structures of solids

    CERN Document Server

    Coles, B R

    2013-01-01

    The Electronic Structures of Solids aims to provide students of solid state physics with the essential concepts they will need in considering properties of solids that depend on their electronic structures and idea of the electronic character of particular materials and groups of materials. The book first discusses the electronic structure of atoms, including hydrogen atom and many-electron atom. The text also underscores bonding between atoms and electrons in metals. Discussions focus on bonding energies and structures in the solid elements, eigenstates of free-electron gas, and electrical co

  4. Basic principles of electronics thermionics

    CERN Document Server

    Jenkins, J

    2013-01-01

    Basic Principles of Electronics, Volume I: Thermionics covers topics related to thermionic devices. The book starts by providing a physical background about electronics, including structure of matter, ionic, chemical and covalent combination, crystalline structure, conductors and insulators, and thermionic emission. The text then discusses electron dynamics; the characteristics and properties of electrons in solids; electron emission; and thermionic emission in a vacuum diode or triode. The development of the vacuum triode; gas-filled valves; and power amplifiers are also considered. The book

  5. Electronic Commerce Removing Regulatory Impediments

    Science.gov (United States)

    1992-05-01

    AD-A252 691 ELECTRONIC COMMERCE Removing Regulatory Impediments ~DuiG A% ELECTE I JUL1 8 1992 0 C D Daniel J. Drake John A. Ciucci ... - ""N ST AT KE...Management Institute 6400 Goldsboro Road Bethesda, Maryland 20817-5886 92 LMI Executive Summary ELECTRONIC COMMERCE : REMOVING REGULATORY IMPEDIMENTS... Electronic Commerce techniques, such as electronic mail and electronic data interchange (EDI), enable Government agencies to conduct business without the

  6. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    Toshimi Suda

    2014-11-01

    A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world’s first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density distributions of short-lived exotic nuclei by elastic electron scattering. The first collision between electrons and exotic nuclei will be observed in the year 2014.

  7. PREFACE: Correlated Electrons (Japan)

    Science.gov (United States)

    Miyake, Kazumasa

    2007-03-01

    This issue of Journal of Physics: Condensed Matter is dedicated to results in the field of strongly correlated electron systems under multiple-environment. The physics of strongly correlated electron systems (SCES) has attracted much attention since the discovery of superconductivity in CeCu_2 Si_2 by Steglich and his co-workers a quater-century ago. Its interest has been intensified by the discovery of high-Tc superconductivity in a series of cuprates with layered perovskite structure which are still under active debate. The present issue of Journal of Physics: Condensed Matter present some aspects of SCES physics on the basis of activities of a late project "Centre-Of-Excellence" supported by MEXT (Ministry of Education, Sports, Science, Culture and Technology of the Japanese Government). This project has been performed by a condensed matter physics group in the faculties of science and engineering science of Osaka University. Although this project also covers correlated phenomena in optics and nano-scale systems, we focus here on the issues of SCES related to superconductivity, mainly unconventional. The present issue covers the discussions on a new mechanism of superconductivity with electronic origin (critical valence fluctuation mechanism), interplay and unification of magnetism and superconductivity in SCES based on a systematic study of NQR under pressure, varieties of Fermi surface of Ce- and U-based SCES probed by the de Haas-van Alphen effect, electronic states probed by a bulk sensitive photoemission spectroscopy with soft X-ray, pressure induced superconductivity of heavy electron materials, pressure dependence of superconducting transition temperature based on a first-principle calculation, and new superconductors under very high-pressure. Some papers offer readers' reviews of the relevant fields and/or include new developments of this intriguing research field of SCES. Altogether, the papers within this issue outline some aspects of electronic states

  8. Electronic health record

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    The European Commission wants to boost the digital economy by enabling all Europeans to have access to online medical records anywhere in Europe by 2020. With the newly enacted Directive 2011/24/EU on Patients’ Rights in cross border healthcare due for implementation by 2013, it is inevitable...... that a centralised European health record system will become a reality even before 2020. However, the concept of a centralised supranational central server raises concern about storing electronic medical records in a central location. The privacy threat posed by a supranational network is a key concern. Cross border...... and Interoperable electronic health record systems make confidential data more easily and rapidly accessible to a wider audience and increases the risk that personal data concerning health could be accidentally exposed or easily distributed to unauthorised parties by enabling greater access to a compilation...

  9. Electronic health records

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    The European Commission wants to boost the digital economy by enabling all Europeans to have access to online medical records anywhere in Europe by 2020. With the newly enacted Directive 2011/24/EU on patients’ rights in cross-border healthcare due for implementation by 2013, it is inevitable...... that a centralised European health record system will become a reality even before 2020. However, the concept of a centralised supranational central server raises concern about storing electronic medical records in a central location. The privacy threat posed by a supranational network is a key concern. Cross......-border and Interoperable electronic health record systems make confidential data more easily and rapidly accessible to a wider audience and increase the risk that personal data concerning health could be accidentally exposed or easily distributed to unauthorised parties by enabling greater access to a compilation...

  10. Uniform quantized electron gas

    Science.gov (United States)

    Høye, Johan S.; Lomba, Enrique

    2016-10-01

    In this work we study the correlation energy of the quantized electron gas of uniform density at temperature T  =  0. To do so we utilize methods from classical statistical mechanics. The basis for this is the Feynman path integral for the partition function of quantized systems. With this representation the quantum mechanical problem can be interpreted as, and is equivalent to, a classical polymer problem in four dimensions where the fourth dimension is imaginary time. Thus methods, results, and properties obtained in the statistical mechanics of classical fluids can be utilized. From this viewpoint we recover the well known RPA (random phase approximation). Then to improve it we modify the RPA by requiring the corresponding correlation function to be such that electrons with equal spins can not be on the same position. Numerical evaluations are compared with well known results of a standard parameterization of Monte Carlo correlation energies.

  11. Basics of RF electronics

    CERN Document Server

    Gallo, A

    2011-01-01

    RF electronics deals with the generation, acquisition and manipulation of high-frequency signals. In particle accelerators signals of this kind are abundant, especially in the RF and beam diagnostics systems. In modern machines the complexity of the electronics assemblies dedicated to RF manipulation, beam diagnostics, and feedbacks is continuously increasing, following the demands for improvement of accelerator performance. However, these systems, and in particular their front-ends and back-ends, still rely on well-established basic hardware components and techniques, while down-converted and acquired signals are digitally processed exploiting the rapidly growing computational capability offered by the available technology. This lecture reviews the operational principles of the basic building blocks used for the treatment of high-frequency signals. Devices such as mixers, phase and amplitude detectors, modulators, filters, switches, directional couplers, oscillators, amplifiers, attenuators, and others are d...

  12. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  13. Conversion electron surface imaging

    CERN Document Server

    Irwin, G M; Wehner, A

    1999-01-01

    A method of imaging the Moessbauer absorption over the surface of a sample based on counting conversion electrons emitted from the surface following resonant absorption of gamma radiation is described. This Conversion Electron Surface Imaging (CESI) method is somewhat analogous to Magnetic Resonance Imaging (MRI), particularly chemical shift imaging, and similar tomographic reconstruction techniques are involved in extracting the image. The theory behind the technique and a prototype device is described, as well as the results of proof-of-principle experiments which demonstrate the function of the device. Eventually this same prototype device will be part of a system to determine the spatial variation of the Moessbauer spectrum over the surface of a sample. Applications include imaging of variations of surface properties of steels and other iron containing alloys, as well as other surfaces over which sup 5 sup 7 Fe has been deposited.

  14. Semiconductor Physical Electronics

    CERN Document Server

    Li, Sheng

    2006-01-01

    Semiconductor Physical Electronics, Second Edition, provides comprehensive coverage of fundamental semiconductor physics that is essential to an understanding of the physical and operational principles of a wide variety of semiconductor electronic and optoelectronic devices. This text presents a unified and balanced treatment of the physics, characterization, and applications of semiconductor materials and devices for physicists and material scientists who need further exposure to semiconductor and photonic devices, and for device engineers who need additional background on the underlying physical principles. This updated and revised second edition reflects advances in semicondutor technologies over the past decade, including many new semiconductor devices that have emerged and entered into the marketplace. It is suitable for graduate students in electrical engineering, materials science, physics, and chemical engineering, and as a general reference for processing and device engineers working in the semicondi...

  15. Keeping electronic records secure.

    Science.gov (United States)

    Easton, David

    2013-10-01

    Are electronic engineering maintenance records relating to the hospital estate or a medical device as important as electronic patient records? Computer maintenance management systems (CMMS) are increasingly being used to manage all-round maintenance activities. However, the accuracy of the data held on them, and a level of security that prevents tampering with records, or other unauthorised changes to them to 'cover' poor practice, are both essential, so that, should an individual be injured or killed on hospital grounds, and a law suit follow, the estates team can be confident that it has accurate data to prove it has fulfilled its duty of care. Here David Easton MSc CEng FIHEEM MIET, director of Zener Engineering Services, and chair of IHEEM's Medical Devices Advisory Group, discusses the issues around maintenance databases, and the security and integrity of maintenance data.

  16. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G.; Thorn, A.

    2013-12-16

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

  18. Pursuing prosthetic electronic skin

    Science.gov (United States)

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

  19. Pulsed electron beam precharger

    Energy Technology Data Exchange (ETDEWEB)

    Finney, W.C. (ed.); Shelton, W.N.

    1991-01-01

    Electron beam precharging of a high resistivity aerosol was successfully demonstrated during this reporting period (Quarters Five and Six). The initial E-beam particle precharging experiments completed this term were designed to confirm and extend some of the work performed under the previous contract. There are several reasons for doing this: (1) to re-establish a baseline performance criterion for comparison to other runs, (2) to test several recently upgraded or repaired subsystems, and (3) to improve upon the collection efficiency of the electron beam precipitator when testing precharging effectiveness with a very high resistivity, moderate-to-high concentration dust load. In addition, these shakedown runs were used to determine a set of suitable operational parameters for the wind tunnel, the electrostatic collecting sections, and the MINACC E-beam accelerator. These parameters will generally be held constant while the precharging parameters are varied to produce an optimum particle charge.

  20. Power electronics reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Stanley, James K.; Smith, Mark A.; Atcitty, Stanley

    2010-10-01

    The project's goals are: (1) use experiments and modeling to investigate and characterize stress-related failure modes of post-silicon power electronic (PE) devices such as silicon carbide (SiC) and gallium nitride (GaN) switches; and (2) seek opportunities for condition monitoring (CM) and prognostics and health management (PHM) to further enhance the reliability of power electronics devices and equipment. CM - detect anomalies and diagnose problems that require maintenance. PHM - track damage growth, predict time to failure, and manage subsequent maintenance and operations in such a way to optimize overall system utility against cost. The benefits of CM/PHM are: (1) operate power conversion systems in ways that will preclude predicted failures; (2) reduce unscheduled downtime and thereby reduce costs; and (3) pioneering reliability in SiC and GaN.