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Sample records for amplification causing pregnancy-induced

  1. Subarachnoid hemorrhage caused by pregnancy induced hypertension: A rare occurrence

    OpenAIRE

    Chandrashekhar Anil Sohoni

    2013-01-01

    This article presents the case of a young primigravida with pregnancy induced hypertension (PIH) presenting with seizure in the post-partum period. Magnetic resonance imaging revealed the presence of isolated convexal subarachnoid hemorrhage (cSAH). The absence of any other demonstrable vascular anomaly or coagulopathy on further investigation suggested PIH as the cause of cSAH.

  2. Subarachnoid hemorrhage caused by pregnancy induced hypertension: A rare occurrence

    Directory of Open Access Journals (Sweden)

    Chandrashekhar Anil Sohoni

    2013-01-01

    Full Text Available This article presents the case of a young primigravida with pregnancy induced hypertension (PIH presenting with seizure in the post-partum period. Magnetic resonance imaging revealed the presence of isolated convexal subarachnoid hemorrhage (cSAH. The absence of any other demonstrable vascular anomaly or coagulopathy on further investigation suggested PIH as the cause of cSAH.

  3. Antidepressant medication and the risk of pregnancy-induced hypertension

    NARCIS (Netherlands)

    Ter Heijne, Loes F.; Zakiyah, Neily; Bos, Jens H.J.; Hak, Eelko; Schuiling-Veninga, Catharina C.M.

    2016-01-01

    Background: Increased activity of the sympatic nervous system could possibly cause pregnancy-induced hypertension (PIH). Previous studies have suggested that antidepressants could contribute to this increased activity. Objectives: To examine whether the use of antidepressants during pregnancy

  4. Two-Tone Interference Caused by Active Amplification

    Science.gov (United States)

    Duke, T. A. J.; Andor, D.; Jülicher, F.

    2003-02-01

    To capture faint sounds, the ear uses an active system of amplification. We and our colleagues have put forward the idea that the amplifier comprises a set of "self-tuned critical oscillators": each hair cell contains a force-generating dynamical system which is maintained at the threshold of an oscillatory instability, or Hopf bifurcation. Our analysis shows that the active response to a pure tone is perfectly suited to the ear's needs, since it provides frequency selectivity, exquisite sensitivity and wide dynamic range. However, the intrinsic nonlinearity of the mechanism causes tones of different frequency to interfere with one another in the cochlea. In order to provide a framework for understanding how the ear processes the more complex sounds of speech and music, we have examined the response of a critical Hopf oscillator to two tones. Our calculations indicate how the response to one tone is suppressed by the presence of a second tone of similar frequency. They also show how a characteristic spectrum of distortion products is generated. Based on this analysis, we discuss to what extent psychophysical phenomena such as the sensation of dissonance and auditory illusions can be attributed to the physical nature of the peripheral detection apparatus.

  5. [Pregnancy-induced haemolytic anaemia].

    Science.gov (United States)

    Karagiozova, J; Masseva, A; Ivanov, St; Marinov, B; Kulinska, R; Boiadjiev, D; Jordanova, D

    2014-01-01

    This is the clinical case of a primiparous eight month pregnant female, presenting with symptoms of pregnancy-induced acute haemolytic anaemia (haemolytic aneamia provoked by an immune mechanism, intra- and extra-erythrocyte defects, and HELLP syndrome were excluded). The anaemia progressed to become life-threatening for both the pregnant women and the foetus, which brought the following questions into consideration: diagnosis of anaemia during pregnancy; dosing of corticosteroid therapy; possibility of giving birth to a viable foetus and prognosis for next pregnancies. Owing to the inter-disciplinary efforts, the life and health of this pregnant woman were preserved, but the foetus was lost.

  6. Seasonal Variation in the Occurrence of Pregnancy-Induced ...

    African Journals Online (AJOL)

    Pregnancy-Induced Hypertension (PIH) is one of the leading causes of maternal, neonatal and infant mortality. Several studies have suggested that the occurrence of PIH may be dependent on environmental factors. Although, several countries have documented the prevalence of PIH, little is known about the occurrence ...

  7. Study of dynamic amplification factor of DEMO blanket caused by a gap at the supporting key

    International Nuclear Information System (INIS)

    Frosi, Paolo; Mazzone, Giuseppe

    2015-01-01

    Highlights: • With the preliminary hypothesis established, the dynamic displacements are not so high and the state of stress (not reported) does not exhibit large region with plastic strain. • The dynamic displacements show a certain dependency from the mesh adopted, and the geometry chosen. • The energy (kinetic or strain) of the whole structure gives useful information about the key behavior during impact. • In order to better understand the overall phenomenon other details (non-linear material, better evaluation of damping, other disruption rise-times and so on. - Abstract: Among the design activities of the in vessel components for DEMO promoted by European Fusion Development Agreement (EFDA) organization, this work deals with the gap required at the supporting keys of the blanket. Due to its higher operating temperatures compared to the vacuum vessel (VV) ones, this gap will increase during operation. The electro magnetic (EM) loads due to fast disruptions occur on a short time and might accelerate the blanket significantly before it touches the supporting keys, causing an impact of the blanket itself onto the keys. Depending on their stiffness, the EM loads with their short time scale could excite the structure's natural frequencies, causing dynamic amplification. Both phenomena (impact and dynamic amplification) can cause stresses in the structure significantly higher than the static ones. This work develops a finite element model of DEMO blanket to study its non-linear transient dynamic behavior under impact loadings. A VV sector, the ribs between the inner and outer VV, the backward manifolds and the supporting keys of the blanket have been modeled. The analyses have been performed with Abaqus [1] and Ansys [2] FEM codes focused on the displacements of the keys in their housing on the blanket. The dynamic amplification factor has been evaluated as the ratio of dynamic to static displacements in meaningful points of the structure for a growing gap

  8. Study of dynamic amplification factor of DEMO blanket caused by a gap at the supporting key

    Energy Technology Data Exchange (ETDEWEB)

    Frosi, Paolo, E-mail: paolo.frosi@enea.it; Mazzone, Giuseppe

    2015-10-15

    Highlights: • With the preliminary hypothesis established, the dynamic displacements are not so high and the state of stress (not reported) does not exhibit large region with plastic strain. • The dynamic displacements show a certain dependency from the mesh adopted, and the geometry chosen. • The energy (kinetic or strain) of the whole structure gives useful information about the key behavior during impact. • In order to better understand the overall phenomenon other details (non-linear material, better evaluation of damping, other disruption rise-times and so on. - Abstract: Among the design activities of the in vessel components for DEMO promoted by European Fusion Development Agreement (EFDA) organization, this work deals with the gap required at the supporting keys of the blanket. Due to its higher operating temperatures compared to the vacuum vessel (VV) ones, this gap will increase during operation. The electro magnetic (EM) loads due to fast disruptions occur on a short time and might accelerate the blanket significantly before it touches the supporting keys, causing an impact of the blanket itself onto the keys. Depending on their stiffness, the EM loads with their short time scale could excite the structure's natural frequencies, causing dynamic amplification. Both phenomena (impact and dynamic amplification) can cause stresses in the structure significantly higher than the static ones. This work develops a finite element model of DEMO blanket to study its non-linear transient dynamic behavior under impact loadings. A VV sector, the ribs between the inner and outer VV, the backward manifolds and the supporting keys of the blanket have been modeled. The analyses have been performed with Abaqus [1] and Ansys [2] FEM codes focused on the displacements of the keys in their housing on the blanket. The dynamic amplification factor has been evaluated as the ratio of dynamic to static displacements in meaningful points of the structure for a growing

  9. Isothermal Amplification and Lateral-Flow Assay for Detecting Crown-Gall-Causing Agrobacterium spp.

    Science.gov (United States)

    Fuller, Skylar L; Savory, Elizabeth A; Weisberg, Alexandra J; Buser, Jessica Z; Gordon, Michael I; Putnam, Melodie L; Chang, Jeff H

    2017-09-01

    Agrobacterium is a genus of soilborne gram-negative bacteria. Members carrying oncogenic plasmids can cause crown gall disease, which has significant economic costs, especially for the orchard and nursery industries. Early and rapid detection of pathogenic Agrobacterium spp. is key to the management of crown gall disease. To this end, we designed oligonucleotide primers and probes to target virD2 for use in a molecular diagnostic tool that relies on isothermal amplification and lateral-flow-based detection. The oligonucleotide tools were tested in the assay and evaluated for detection limit and specificity in detecting alleles of virD2. One set of primers that successfully amplified virD2 when used with an isothermal recombinase was selected. Both tested probes had detection limits in picogram amounts of DNA. Probe 1 could detect all tested pathogenic isolates that represented most of the diversity of virD2. Finally, the coupling of lateral-flow detection to the use of these oligonucleotide primers in isothermal amplification helped to reduce the onerousness of the process, and alleviated reliance on specialized tools necessary for molecular diagnostics. The assay is an advancement for the rapid molecular detection of pathogenic Agrobacterium spp.

  10. Loop-mediated isothermal amplification (LAMP) based detection of Colletotrichum falcatum causing red rot in sugarcane.

    Science.gov (United States)

    Chandra, Amaresh; Keizerweerd, Amber T; Que, Youxiong; Grisham, Michael P

    2015-08-01

    Red rot, caused by Colletotrichum falcatum, is a destructive disease prevalent in most sugarcane-producing countries. Disease-free sugarcane planting materials (setts) are essential as the pathogen spreads primarily through infected setts. The present study was undertaken to develop a loop-mediated isothermal amplification (LAMP) assay for the detection of C. falcatum. C. falcatum genomic DNA was isolated from pure mycelium culture and infected tissues. Four sets of primers corresponding to a unique DNA sequence specific to C. falcatum were designed. Specificity of the LAMP test was checked with DNA of another fungal pathogen of sugarcane, Puccinia melanocephala, as well as two closely-related species, Colletotrichum fructivorum and Colletotrichum acutatum. No reaction was found with the three pathogens. When C. falcatum DNA from pure culture was used in a detection limit analysis, sensitivity of the LAMP method was observed to be ten times higher than that of conventional PCR; however, sensitivity was only 5 times higher when DNA from C. falcatum-infected tissues was used. Using the LAMP assay, C. falcatum DNA is amplified with high specificity, efficiency, and rapidity under isothermal conditions. Moreover, visual judgment of color change in <1 h without further post-amplification processing makes the LAMP method convenient, economical, and useful in diagnostic laboratories and the field.

  11. Gene amplification as a cause of inherited thyroxine-binding globulin excess in two Japanese families

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Yuichi; Miura, Yoshitaka; Saito, Hidehiko [Toyota Memorial Hospital (Japan)] [and others

    1995-12-01

    T{sub 4}-binding globulin (TBG) is the major thyroid hormone transport protein in man. Inherited abnormalities in the level of serum TBG have been classified as partial deficiency, complete deficiency, and excess. Sequencing analysis of the TBG gene, located on Xq21-22, has uncovered the molecular defects causing partial and complete deficiency. However, the mechanism leading to inherited TBG excess remains unknown. In this study, two Japanese families, F-A and F-T, with inherited TBG excess were analyzed. Serum TBG levels in hemizygous males were 58 and 44 {mu}g/mL, 3- and 2-fold the normal value, respectively. The molecule had normal properties in terms of heat stability and isoelectric focussing pattern. The sequence of the coding region and the promoter activity of the TBG gene were also indistinguishable between hemizygotes and normal subjects. The gene dosage of TBG relative to that of {beta}-globin, which is located on chromosome 11, and Duchenne muscular dystropy, which is located on Xp, was evaluated by coamplification of these target genes using polymerase chain reaction and subsequent quantitation by HPLC. The TBG/{beta}-globin ratios of the affected male and female of F-A were 3.13 and 4.13 times, respectively, that in the normal males. The TBG/Duchenne muscular dystrophy ratios were 2.92 and 2.09 times the normal value, respectively. These results are compatible with three copies of TBG gene on the affected X-chromosome. Similarly, a 2-fold increase in gene dosage was demonstrated in the affected hemizygote of F-T. A 3-fold tandem amplification of the TBG gene was shown by in situ hybridization of prometaphase and interphase chromosomes from the affected male with a biotinylated genomic TBG probe, confirming the gene dosage results. Gene amplification of TBG is the cause of inherited TBG excess in these two families. 35 refs., 3 figs., 2 tabs.

  12. Use of antidepressants during pregnancy and the risk of pregnancy-induced hypertension

    NARCIS (Netherlands)

    Van Loveren, Fianne MAM; Boekema, Monique; Hak, Eelko; Bos, Jens HJ; Aarnoudse, Jan G; Schuiling-Veninga, Catharina CM

    2014-01-01

    Background: Pregnancy-induced hypertension (PIH) is possibly caused by an increased activity of the sympatic nervous system. Previous studies have suggested that inhibition of the re-uptake of serotonin and norepinephrine by selective serotonin re-uptake inhibitors (SSRIs) and tricyclic

  13. Study of serum lipid profile in pregnancy induced hypertension in ...

    African Journals Online (AJOL)

    At recent times, there has been a great interest on the role of lipid metabolism in the development of pregnancy induced hypertension and pre-eclampsia ... Results: Mean serum triglyceride was higher in (Group 1) pregnant women with pregnancy induced hypertension than in Groups 2 and 3, this was however not ...

  14. Pregnancy-induced progression of keratoconus.

    Science.gov (United States)

    Bilgihan, Kamil; Hondur, Ahmet; Sul, Sabahattin; Ozturk, Sertac

    2011-09-01

    To report eyes with keratoconus that progressed during pregnancy. Seven eyes of 4 patients with progression of keratoconus during pregnancy were included in this study. The mean age of patients and the mean follow-up duration were 29.3 years and 39 months, respectively. Progressive keratoconus was documented with changes in refraction, corneal topography, and rigid gas-permeable lens fitting pattern. Patients with accompanying systemic and ocular diseases associated with keratoconus, uncontrolled atopic disease, and eye rubbing were excluded. Mean increase in spherical equivalent refraction and simulated keratometry values were 1.4 ± 1.1 and 1.1 ± 0.8 diopters, respectively. In eyes wearing rigid gas-permeable lenses, increase in corneal apical touch and decrease in the base curve radius of the best-fitting contact lens were observed. Hormonal changes during pregnancy may affect corneal biomechanics negatively, and pregnancy may be a previously unrecognized risk factor for progression of keratoconus. To our knowledge, this is the first study showing pregnancy-induced keratoconus progression in patients with no accompanying disease.

  15. Platelet activation in pregnancy-induced hypertension.

    Science.gov (United States)

    Karalis, Ioannis; Nadar, Sunil K; Al Yemeni, Eman; Blann, Andrew D; Lip, Gregory Y H

    2005-01-01

    Although excess platelet activation, as indicated by increased plasma beta thromboglobulin (beta-TG), has been shown in pregnancy-induced hypertension (PIH), platelet adhesion, platelet morphology and a comparison of platelet and soluble (plasma) levels of the adhesion molecules P-selectin (pPsel and sPsel, respectively) have not been studied. We conducted a cross-sectional study of 35 consecutive women with PIH (age 31+/-6 years), 31 consecutive women with normotensive pregnancies (age 29+/-5 years) and 30 normotensive non pregnant women (age 30+/-5 years). Platelet adhesion was studied in vitro by binding to fibrinogen-coated microwells, platelet morphology [mass and volume by flow cytometry], whole-platelet P-selectin (pPsel) by ELISA of the lysate of 2 x 10(8) cells, and the plasma markers soluble P-selectin (sP-sel) and beta-TG, by ELISA. The women with PIH had significantly raised sPsel, pPsel and (as expected) beta-TG (all p<0.05), when compared to the normotensive pregnant women and controls. However, in PIH platelet adhesion was similar to that in the normotensive pregnancy, but still higher than the normal controls (p<0.001). There was no difference among the three groups with respect to platelet mass and volume. pPsel and platelet adhesion correlated with gestational age and with systolic and diastolic blood pressure (all p<0.05). Increased platelet activation and adhesion develop during normal pregnancy, with some indices being further altered in PIH.

  16. Retinal changes in pregnancy-induced hypertension

    Directory of Open Access Journals (Sweden)

    Akash Pankaj Shah

    2015-01-01

    Full Text Available Aims: The aim was to determine the prevalence of retinal changes in pregnancy-induced hypertension (PIH and any association between the retinal changes and age, parity, blood pressure, proteinuria, and severity of the disease. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: All the patients admitted with a diagnosis of PIH were included in this study. Age, gravida, gestation period, blood pressure, and proteinuria were noted from the case records. Fundus examination was done with a direct ophthalmoscope. The findings were noted and were analyzed using SPSS program. Results: A total of 150 patients of PIH were examined. The mean age of patients was 25.1 years. The gestation period ranged from 27 weeks to 42 weeks; 76 (50.67% were the primi gravida. 92 (61.33% patients had gestational hypertension, 49 (32.67% patients had preeclampsia, and 9 (6% had eclampsia. Retinal changes (hypertensive retinopathy were noted in 18 (12% patients - Grade 1 in 12 (8% and Grade 2 in 6 (4%. Hemorrhages or exudates or retinal detachment were not seen in any patient. There was statistically significant positive association of retinal changes and blood pressure (P = 0.037, proteinuria (P = 0.0005, and severity of the PIH (P = 0.004. Conclusions: Retinal changes were seen in 12% of patients with PIH. Occurrence of hypertensive retinopathy in PIH cases has been decreased due to better antenatal care and early detection and treatment of PIH cases. There is a greater chance of developing retinopathy with increase in blood pressure, severity of PIH, and proteinuria in cases of PIH.

  17. Detection of Puccinia kuehnii Causing Sugarcane Orange Rust with a Loop-Mediated Isothermal Amplification-Based Assay.

    Science.gov (United States)

    Chandra, Amaresh; Keizerweerd, Amber T; Grisham, Michael P

    2016-03-01

    Puccinia kuehnii is a fungal pathogen that causes orange rust in sugarcane, which is now prevalent in many countries. At the early stage of disease, it is almost indistinguishable from brown rust, which is caused by Puccinia melanocephala. Although several PCR assays are available to detect these diseases, the loop-mediated isothermal amplification (LAMP)-based assay has been reported to be more economical and easier to perform. Under isothermal conditions, DNA is amplified with high specificity and rapidity. Moreover, visual judgment of color change without further post-amplification processing makes the method convenient. The present study was undertaken to detect P. kuehnii genomic DNA using four primers corresponding to a unique DNA sequence of P. kuehnii. The LAMP assay was found to be optimal when 8 mM MgSO4 was used and the reaction was incubated at 63 °C for 90 min. Positive samples showed a color change from orange to green upon SYBR Green I dye addition. Specificity of the LAMP test was checked with DNA of P. melanocephala, which showed no reaction. Sensitivity of the LAMP method was observed to be the same as real-time PCR at 0.1 ng, thus providing a rapid and more affordable option for early disease detection.

  18. Peripheral microcirculation during pregnancy and in women with pregnancy induced hypertension.

    Science.gov (United States)

    Ohlmann, P; Jung, F; Mrowietz, C; Alt, T; Alt, S; Schmidt, W

    2001-01-01

    During pregnancy the cardiovascular system undergoes several changes so as to adapt the maternal organism to the strains of pregnancy. These adaptations can assume a pathological development in persons with a previous history of cardiovascular problems. On the other hand the absence of these adaptations may lead to a pathological course of pregnancy. Pregnancy induced hypertension (PIH) may be such a pathological development due to maladaptation. The causes are for the most part unknown. For some time it has been assumed that it is due to microcirculatory disorders. Using periungual capillary microscopy the present study prospectively investigated the changes in peripheral microcirculation during pregnancy focussing on pregnancy induced hypertension. Sixty-seven women with a normal course of pregnancy and 28 women with pregnancy induced hypertension were evaluated. Throughout the prospective study 3 examinations were performed during pregnancy and one during childbed. The women who developed a PIH were registered during the third trimester. Erythrocyte velocity at rest and vascular reagibility of capillaries following a 3 minute ischaemia were evaluated. In the course of pregnancy a significant increase of approximately 30% in erythrocyte velocity could be observed. Interpolation to obtain the best strait line result demonstrates that it is a continuous increase. Erythrocyte velocity returns to normal in the course of 14 weeks post partum. Due to a physiological vasodilatation during pregnancy, vascular reaction to ischaemic stress significantly decreases. During childbed these changes return to normal. Examinations on women with pregnancy induced hypertension not only showed a significant reduction of microcirculation under resting conditions but also a different pattern of reaction to ischaemic stress. Erythrocyte velocity under resting conditions lies 36% below normal values. Furthermore the distinctly shortened hyperaemic period indicates a hightened

  19. Frequency of maternal mortality and morbidity in pregnancy-induced hypertension

    International Nuclear Information System (INIS)

    Riaz, S.; Jabeen, A.

    2011-01-01

    Background: Pregnancy-induced hypertension (PIH) is defines as hypertension in pregnancy, and is sustained blood pressure >140 mm Hg systolic or 90 mm Hg diastolic. Objective of this study was to see the maternal outcome in terms of morbidity and mortality in PIH. Methods: This descriptive study was conducted in Obstetrics and Gynaecology Unit of Fauji Foundation Hospital, Rawalpindi from January to December 2010. Both booked and un-booked cases were selected after fulfilling inclusion criteria. A detailed history and clinical examination was recorded and relevant investigations were performed. Patients were monitored for rise in blood pressure, development of complications related to hypertensions in pregnancy as well as maternal and perinatal outcome. Results: During this period, 100 patients were admitted with pregnancy-induced hypertension. Majority were un-booked. Primigravida were 60 (60%), and were in age group 21-30 year, remaining were above 30 year. Four patients had placental abruption, 2 pulmonary oedema, 5 HELLP syndrome, 2 severe renal impairment, 20 elevated liver enzyme, 23 uncontrolled blood pressure, 20 server preeclampsia, 10 thrombocytopenia, 3 eclampsia, 10 had impaired coagulation profile, and 1 had maternal death. Conclusion: Pregnancy induced hypertension is a major cause of maternal mortality and morbidity. In Pakistan, its incidence and related mortality are high due to lack of adequate antenatal care. (author)

  20. Magnesium supplement in pregnancy-induced hypertension. A clinicopathological study

    DEFF Research Database (Denmark)

    Rudnicki, M; Junge, Jette; Frølich, A

    1990-01-01

    The placenta and the umbilical cord obtained from 18 women with pregnancy-induced hypertension were investigated by light microscopy. The umbilical artery was studied by electron microscopy. 10 placentae and umbilical cords from normal pregnancies served as controls. The study was performed...... fibrosis or intervillous fibrin. Ultrastructurally, the endothelial cells of the umbilical arteries from women with pregnancy-induced hypertension showed a significant increase in the amount of dilated endoplasmic reticulum and basal laminae thickness when all 18 cases were compared with the controls....... There was no significant difference when the magnesium group, the placebo group and the control group were compared separately. The present study suggests that magnesium supplement has a beneficial effect on fetal growth in pregnancy-induced hypertension. With regard to the light and electron microscopic changes we were...

  1. Ambient air pollution and pregnancy-induced hypertensive disorders

    DEFF Research Database (Denmark)

    Pedersen, Marie; Stayner, Leslie; Slama, Rémy

    2014-01-01

    to ambient air pollution and pregnancy-induced hypertensive disorders including gestational hypertension and preeclampsia. We searched electronic databases for English language studies reporting associations between ambient air pollution and pregnancy-induced hypertensive disorders published between December.......5), carbon monoxide (CO), ozone (O3), proximity to major roads, and traffic density met our inclusion criteria. Most studies reported that air pollution increased risk for pregnancy-induced hypertensive disorders. There was significant heterogeneity in meta-analysis, which included 16 studies reporting...... on gestational hypertension and preeclampsia as separate or combined outcomes; there was less heterogeneity in findings of the 10 studies reporting solely on preeclampsia. Meta-analyses showed increased risks of hypertensive disorders in pregnancy for all pollutants except CO. Random-effect meta...

  2. A single splice site mutation in human-specific ARHGAP11B causes basal progenitor amplification

    Science.gov (United States)

    Florio, Marta; Namba, Takashi; Pääbo, Svante; Hiller, Michael; Huttner, Wieland B.

    2016-01-01

    The gene ARHGAP11B promotes basal progenitor amplification and is implicated in neocortex expansion. It arose on the human evolutionary lineage by partial duplication of ARHGAP11A, which encodes a Rho guanosine triphosphatase–activating protein (RhoGAP). However, a lack of 55 nucleotides in ARHGAP11B mRNA leads to loss of RhoGAP activity by GAP domain truncation and addition of a human-specific carboxy-terminal amino acid sequence. We show that these 55 nucleotides are deleted by mRNA splicing due to a single C→G substitution that creates a novel splice donor site. We reconstructed an ancestral ARHGAP11B complementary DNA without this substitution. Ancestral ARHGAP11B exhibits RhoGAP activity but has no ability to increase basal progenitors during neocortex development. Hence, a single nucleotide substitution underlies the specific properties of ARHGAP11B that likely contributed to the evolutionary expansion of the human neocortex. PMID:27957544

  3. Quantitation of Proteinuria in Women With Pregnancy Induced ...

    African Journals Online (AJOL)

    This creates the need for a more accurate method for early detection and quantitation of proteinuria. Objective:To compare the accuracy of the Spot urine Protein to Creatinine ratio with that of Dipstick Tests in the quantitation of proteinuria in Nigerian women with Pregnancy Induced Hypertension. Methods: A cross-sectional ...

  4. EG-VEGF Maintenance Over Early Gestation to Develop a Pregnancy-Induced Hypertensive Animal Model.

    Science.gov (United States)

    Reynaud, Déborah; Sergent, Frédéric; Abi Nahed, Roland; Brouillet, Sophie; Benharouga, Mohamed; Alfaidy, Nadia

    2018-01-01

    During the last decade, multiple animal models have been developed to mimic hallmarks of pregnancy-induced hypertension (PIH) diseases, which include gestational hypertension, preeclampsia (PE), or eclampsia. Converging in vitro, ex vivo, and clinical studies from our group strongly suggested the potential involvement of the new angiogenic factor EG-VEGF (endocrine gland-derived-VEGF) in the development of PIH. Here, we described the protocol that served to demonstrate that maintenance of EG-VEGF production over 11.5 days post coitus (dpc) in the gravid mice caused the development of PIH. The developed model exhibited most hallmarks of preeclampsia.

  5. Sources of psychrophilic and psychrotolerant clostridia causing spoilage of vacuum-packed chilled meats, as determined by PCR amplification procedure.

    Science.gov (United States)

    Broda, D M; Boerema, J A; Brightwell, G

    2009-07-01

    To determine possible preslaughter and processing sources of psychrophilic and psychrotolerant clostridia causing spoilage of vacuum-packed chilled meats. Molecular methods based on the polymerase chain reaction (PCR) amplification of specific 16S rDNA fragments were used to detect the presence of Clostridium gasigenes, Clostridium estertheticum, Clostridium algidicarnis and Clostridium putrefaciens in a total of 357 samples collected from ten slaughter stock supply farms, slaughter stock, two lamb-processing plants, their environments, dressed carcasses and final vacuum-packed meat stored at -0.5 degrees C for 5(1/2) weeks. Clostridium gasigenes, C. estertheticum and C. algidicarnis/C. putrefaciens were commonly detected in farm, faeces, fleece and processing environmental samples collected at the slaughter floor operations prior to fleece removal, but all these micro-organisms were detected in only 4 out of 26 cooling floor and chiller environmental samples. One out of 42 boning room environmental samples tested positive for the presence of C. gasigenes and C. estertheticum, but 25 out of 42 of these samples were positive for C. algidicarnis/C. putrefaciens. Nearly all of the 31 faecal samples tested positive for the presence of C. gasigenes and C. estertheticum; however, only two of these samples were positive for C. algidicarnis and/or C. putrefaciens. Clostridial species that were subject to this investigation were frequently detected on chilled dressed carcasses. The major qualitative and quantitative differences between the results of PCR detection obtained with the primers specific for 'blown pack' -causing clostridia (C. gasigenes and C. estertheticum) and those obtained with primers specific for C. algidicarnis and C. putrefaciens suggest that the control of meat spoilage caused by different groups of meat clostridia is best approached individually for each group. This paper provides information significant for controlling meat spoilage-causing clostridia

  6. Rapid detection of Puccinia triticina causing leaf rust of wheat by PCR and loop mediated isothermal amplification.

    Science.gov (United States)

    Manjunatha, C; Sharma, Sapna; Kulshreshtha, Deepika; Gupta, Sangeeta; Singh, Kartar; Bhardwaj, Subhash C; Aggarwal, Rashmi

    2018-01-01

    Leaf rust of wheat caused by Puccinia triticina has significant impact on wheat production worldwide. Effective and quick detection methodologies are required to mitigate yield loss and time constraints associated with monitoring and management of leaf rust of wheat. In the present study, detection of P. triticina has been simplified by developing a rapid, reliable, efficient and visual colorimetric method i.e., loop mediated isothermal amplification of DNA (LAMP). Based on in silico analysis of P. triticina genome, PTS68, a simple sequence repeat was found highly specific to leaf rust fungus. A marker (PtRA68) was developed and its specificity was validated through PCR technique which gave a unique and sharp band of 919 bp in P. triticina pathotypes only. A novel gene amplification method LAMP which enables visual detection of pathogen by naked eye was developed for leaf rust pathogen. A set of six primers was designed from specific region of P. triticina and conditions were optimised to complete the observation process in 60 minutes at 65o C. The assay developed in the study could detect presence of P. triticina on wheat at 24 hpi (pre-symptomatic stage) which was much earlier than PCR without requiring thermal cycler. Sensitivity of LAMP assay developed in the study was 100 fg which was more sensitive than conventional PCR (50 pg) and equivalent to qPCR (100 fg). The protocol developed in the study was utilized for detection of leaf rust infected samples collected from different wheat fields. LAMP based colorimetric detection assay showed sky blue color in positive reaction and violet color in negative reaction after addition of 120 μM hydroxyl napthol blue (HNB) solution to reaction mixture. Similarly, 0.6 mg Ethidium bromide/ml was added to LAMP products, placed on transilluminator to witness full brightness in positive reaction and no such brightness could be seen in negative reaction mixture. Further, LAMP products spread in a ladder like banding pattern in

  7. Amplification and sequencing of varicella zoster virus (VZV) gene 4: point mutation in a VZV strain causing chickenpox during pregnancy

    International Nuclear Information System (INIS)

    Chow, V.T.K.; Lim, K.P.

    1997-01-01

    The varicella-zoster virus (VZV) causes chickenpox (varicella) as the primary disease and shingles (zoster) as a recurrent manifestation of infection, both being generality benign and self-limiting. While these infections may be severe in adults and even life-threatening in immunosuppressed individuals, they may be amenable to effective antiviral drugs or varicella-zoster immune globulin, provided the treatment is administered early. The prompt diagnosis of VZV infections may be accelerated by rapid, sensitive and specific molecular techniques such as amplification by polymerase chain reaction (PCR) compared with slower and more cumbersome tissue culture and serological procedures. Based on the VZV gene 4 which encodes a transcriptional activator, primers were designed for use in PCR to amplify a target fragment of 381 bp. Distinct diagnostic bands were observed by agarose gel electrophoresis of PCR products of VZV strains isolated from II varicella and 7 zoster patients in Singapore, as well as of the Japanese vaccine Oka strain. The detection sensitivity of this PCR assay was determined to be 1 pg of purified VZV DNA equivalent to about 7,000 viral DNA copies. No target bands were amplified from negative control templates from five related human herpes-viruses and from human DNA. The specificity of the PCR products was ensured by direct cycle DNA sequencing, which revealed complete identity of the 18 VZV isolates with the published European Dumas strain. The strong sequence conservation of the target fragment renders this PCR assay highly reliable for detecting the VZV sequence. Only one VZV strain isolated from a patient with varicella during pregnancy exhibited a Gaga to GAA point mutation at codon 46 of gene 4, culminating in the non-conservative substitution of Ser with Phe. The predicted secondary structure of the mutant polypeptide portrayed a radical alteration, which may influence its function in transcriptional activation. (authors)

  8. Dietary determinants of pregnancy induced hypertension in Isfahan

    Directory of Open Access Journals (Sweden)

    Zamzam Paknahad

    2008-02-01

    Full Text Available

    • BACKGROUND: Pregnancy-induced hypertension (PIH is a pregnancy-specific condition that occurs after the 20th week of gestation. These physiologic changes can be aggravated by undernutrition. There are some evidence based on the importance of nutrient deficiency in developing this syndrome. Therefore, the aim of present study was to determine the nutritional risk factors for pregnancy induced hypertension in a group of pregnant women in Isfahan.
    • METHODS: In this case-control study, we recruited 46 Isfahanian pregnant women in two groups (with and without PIH. They were 19 to 45 year-old and they did not consume any antihypertensive or diuretic medications. Demographic questionnaire and food frequency questionnaire were filled in both groups.
    • RESULTS: There were no significant differences in energy and vitamin E and C intakes between the two groups. Zinc and calcium intakes were lower in women with PIH compared to those without PIH (P = 0.04 and P = 0.007, respectively. Riboflavin and protein intakes were lower in women with PIH compared to subjects without PIH (P = 0.03 and P = 0.01, respectively.
    • CONCLUSIONS: Lower intake of calcium, zinc, riboflavin and protein should be considered as possible risk factors for PIH. Adequate intake of dairy products which are good sources of mentioned nutrients are recommended to prevent PIH.
    • KEYWORDS: Pregnancy induced hypertension, diet, nutrient.

  9. Magnesium supplement in pregnancy-induced hypertension. A clinicopathological study

    DEFF Research Database (Denmark)

    Rudnicki, M; Junge, Jette; Frølich, A

    1990-01-01

    as a double-blind randomized controlled study in which 11 women were allocated to magnesium and 7 to placebo treatment. The treatment comprised a 48-hour intravenous magnesium/placebo infusion followed by daily oral magnesium/placebo intake until one day after delivery. Magnesium supplement increased birth....... There was no significant difference when the magnesium group, the placebo group and the control group were compared separately. The present study suggests that magnesium supplement has a beneficial effect on fetal growth in pregnancy-induced hypertension. With regard to the light and electron microscopic changes we were...... unable to demonstrate any significant difference between the magnesium, placebo and control groups....

  10. STUDY ON PLATELET INDICES IN PREGNANCY INDUCED HYPERTENSION

    Directory of Open Access Journals (Sweden)

    Rabi a Parveen

    2015-10-01

    Full Text Available INTRODUCTION : Pregnancy induced hypertension includes gestational hypertension, preeclampsia, and eclampsia. In PIH, lower the platelet count, greater are maternal and fetal morbidity and mortality. Recent studies suggest that platele t parameters like platelet indices are most simple and cost effective method for prediction of PIH, way before the appearance of derangements in PT, APTT, TT values so we undertook this study with an aim to see an association between platelet indices and pregnancy induced hypertension. MATERIAL AND METHOD : This was prospective analytical case control study. Study included 125 cases, who were diagnosed as PIH with B.P. > 140/90 mmHg, detected after 20 weeks of pregnancy. Under all aseptic precautions samples were collected randomly in EDTA vials . Samples were analysed for platelet indices . RESULT : Maximum number of cases of Preeclampsia (88.57% & Eclampsia (87.5% were fo und in age group of 21 to 25 . Controls were of same age group i.e. 21 to 25 years. It was observed that platelet count showed gradual decrease in eclampsia (1.44580± 36,210 & pre - e clampsia patients (1.97850± 39,010 as compared to normotensive subjects (2.42620± 40,412. MPV showed gradual increase in eclampsia ( 10.49 ±1.12 & pre - eclampsia ( 9.14 ±0.612 patients as compared to normotensive subjects ( 8.422 ±0.743. PDW value also shows gradual increase in eclampsia ( 18.39 ±2.62 & pre - eclampsia ( 16.29 ±2.34 p atients as compared to normotensive subjects ( 12.09 ±2.53. CONCLUSION : Study showed that platelet indices were important, simple, effortless and cost effective investigations which can be used for early recognition of preventable eclampsia complications.

  11. Protein misfolding cyclic amplification induces the conversion of recombinant prion protein to PrP oligomers causing neuronal apoptosis.

    Science.gov (United States)

    Yuan, Zhen; Yang, Lifeng; Chen, Baian; Zhu, Ting; Hassan, Mohammad Farooque; Yin, Xiaomin; Zhou, Xiangmei; Zhao, Deming

    2015-06-01

    The formation of neurotoxic prion protein (PrP) oligomers is thought to be a key step in the development of prion diseases. Recently, it was determined that the sonication and shaking of recombinant PrP can convert PrP monomers into β-state oligomers. Herein, we demonstrate that β-state oligomeric PrP can be generated through protein misfolding cyclic amplification from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP, and that these oligomers can be used for subsequent research into the mechanisms of PrP-induced neurotoxicity. We have characterized protein misfolding cyclic amplification-induced monomer-to-oligomer conversion of PrP from three species using western blotting, circular dichroism, size-exclusion chromatography, and resistance to proteinase K (PK) digestion. We have further shown that all of the resulting β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, whereas the corresponding monomeric PrP were not toxic. In addition, we found that this toxicity is the result of oligomer-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3 in both wild-type and PrP(-/-) cortical neurons. It is our hope that these results may contribute to our understanding of prion transformation within the brain. We found that β-state oligomeric PrPs can be generated through protein misfolding cyclic amplification (PMCA) from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP. β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, while the corresponding monomeric PrPs were not toxic. This toxicity is the result of oligomers-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3. These results may contribute to our understanding of prion transformation within the brain. © 2015 International Society for Neurochemistry.

  12. Polycystic ovary disease and the risk of pregnancy-induced hypertension.

    Science.gov (United States)

    Kashyap, S; Claman, P

    2000-12-01

    To compare the incidence of pregnancy-induced hypertension in patients with and without polycystic ovary disease (PCOD). We conducted a retrospective, case-control analysis of patients who achieved singleton pregnancies with human menopausal gonadotropin (hMG) therapy. Twenty-two PCOD patients were compared to 27 infertility patients without PCOD who were pregnant after hMG therapy. Non-PCOD patients received hMG for superovulation as part of superovulation/intrauterine insemination or in vitro fertilization/embryo transfer. PCOD patients were receiving hMG for simple ovulation induction. Pregnancy-induced hypertension was defined as late pregnancy blood pressure > 140/90 mm Hg on two readings six hours apart and return to normal blood pressure by four to six weeks postpartum. There were no differences between PCOD and non-PCOD patients with reference to age, body mass index, parity or other pregnancy-induced hypertension risk factors (i.e., chronic hypertension, diabetes or chronic renal disease). Pregnant PCOD patients had a much higher incidence of pregnancy-induced hypertension, 31.8% (7/22), versus non-PCOD patients, who only had a pregnancy-induced hypertension incidence of 3.7% (1/27) (P = .016, OR = 12.1, 95% CI = 1.3-566.8). PCOD patients are at very high risk of pregnancy-induced hypertension when pregnant after ovulation induction.

  13. MATERNAL OUTCOME IN PREGNANCY INDUCED HYPERTENSION IN A TEACHING HOSPITAL IN A RURAL AREA IN TELANGANA

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    Kavitha Reddy Kothapally

    2016-09-01

    Full Text Available AIM To analyse the maternal outcome in pregnancy induced hypertension and improve the management strategies. INTRODUCTION Pregnancy induced hypertension is a medical disease peculiar to pregnancy, making pregnancy a high risk condition. Among medical disorders complicating pregnancy, it stands next to anaemia in prevalence. It is responsible for majority of the maternal morbidity and mortality. It also has an adverse perinatal outcome. Hence, early detection and timely intervention of women with pregnancy induced hypertension is important for good maternal and perinatal outcome. MATERIAL & METHODS The present Prospective Observational study was done from April 2015 to February 2016 in the department of obstetrics & gynaecology at Bhaskar medical college and general hospital, Yenkepally, Moinabad, Telangana. A total of 102 pregnant women with pregnancy induced hypertension were enrolled into the study. Demographic details like age, parity, previous obstetric history of pregnancy induced hypertension and diabetes, past history of polycystic ovarian disease, treatment for infertility, gestational age at which hypertension developed in the present pregnancy were noted. Relevant investigations were performed. Gestational age of delivery, mode of delivery and maternal complications were noted. RESULTS The incidence of pregnancy induced hypertension was 4% in the study population. About 59.8% developed pregnancy induced hypertension in the third trimester. Out of this, 64.7% cases were gestational hypertension and 35.3% cases were preeclampsia. Nearly half (41.7% of preeclampsia cases were severe preeclampsia. Postpartum haemorrhage is the commonest complication (13.7%, next being imminent eclampsia (7.8%, abruption (4.9%, eclampsia (3.9% and HELLP syndrome (0.98%. 80% of cases could be delivered beyond 37 weeks of gestational age. 71.57% of cases had lower segment caesarean section for indicated conditions. More than half of pregnancy induced

  14. Parent-offspring conflict and the persistence of pregnancy-induced hypertension in modern humans.

    Directory of Open Access Journals (Sweden)

    Birgitte Hollegaard

    Full Text Available Preeclampsia is a major cause of perinatal mortality and disease affecting 5-10% of all pregnancies worldwide, but its etiology remains poorly understood despite considerable research effort. Parent-offspring conflict theory suggests that such hypertensive disorders of pregnancy may have evolved through the ability of fetal genes to increase maternal blood pressure as this enhances general nutrient supply. However, such mechanisms for inducing hypertension in pregnancy would need to incur sufficient offspring health benefits to compensate for the obvious risks for maternal and fetal health towards the end of pregnancy in order to explain why these disorders have not been removed by natural selection in our hunter-gatherer ancestors. We analyzed >750,000 live births in the Danish National Patient Registry and all registered medical diagnoses for up to 30 years after birth. We show that offspring exposed to pregnancy-induced hypertension (PIH in trimester 1 had significantly reduced overall later-life disease risks, but increased risks when PIH exposure started or developed as preeclampsia in later trimesters. Similar patterns were found for first-year mortality. These results suggest that early PIH leading to improved postpartum survival and health represents a balanced compromise between the reproductive interests of parents and offspring, whereas later onset of PIH may reflect an unbalanced parent-offspring conflict at the detriment of maternal and offspring health.

  15. A case report: pregnancy-induced severe osteoporosis with eight vertebral fractures.

    Science.gov (United States)

    Ofluoglu, Onder; Ofluoglu, Demet

    2008-12-01

    Osteoporosis associated with pregnancy and lactation is a rare condition. The prevalence, etiology and its pathogenesis is unknown. It causes one or more vertebral fractures with severe, prolonged back pain and height loss in affected women. Majority of the cases are seen in the third trimester or just after delivery in primagravid women. In this case report, a 30-year-old woman who had severe pregnancy-induced osteoporosis with 8 vertebral fractures was presented. During last month of her first pregnancy she had moderate back pain. After delivery, the back pain has gotten worse. The radiological examinations have shown that there was 50% in T6, T8 and T10; 30% in L2; 20% in L1 height loss and biconcave vertebral images in L3-5. In the bone mineral density, L2-4 T score was -4.7 and total femoral T score was -3.1. There was no abnormality in the laboratory findings except mild elevation in alkaline phosphates. Although pregnancy-associated osteoporosis is a rare condition, when pain occurs in the last trimester or early postpartum period, it should be considered in differential diagnosis.

  16. Strain-typical patterns of pregnancy-induced nestbuilding in mice: maternal and experiential influences.

    Science.gov (United States)

    Broida, J; Svare, B

    1982-07-01

    Pregnant C57BL/6J mice incorporate less material into maternal nests and build fewer fully enclosed nests than do pregnant DBA/2J mice. These strain differences are not ameliorated by additional reproductive experience since multiparous animals also exhibit a similar pattern. Reciprocally-crossed hybrid females exhibit DBA-like levels of pregnancy-induced nestbuilding and cross-fostered C57BL and DBA females retain the phenotype of their strain. Experiential and maternal environmental factors apparently are not responsible for strain differences in pregnancy-induced nestbuilding. Differences in ovarian function and/or central neural tissue sensitivity to ovarian hormones may modulate strain differences in pregnancy-induced nestbuilding.

  17. Low sodium diet and pregnancy-induced hypertension: a multi-centre randomised controlled trial

    NARCIS (Netherlands)

    Knuist, M.; Bonsel, G. J.; Zondervan, H. A.; Treffers, P. E.

    1998-01-01

    To examine the effectiveness of the standard policy in the Netherlands to prescribe a sodium restricted diet to prevent or to treat mild pregnancy-induced hypertension. Multi-centre randomised controlled trial between April 1992 and April 1994. Seven practices of independent midwives and one

  18. Pregnancy-Induced Changes in Systemic Gene Expression among Healthy Women and Women with Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Mittal, Anuradha; Pachter, Lior; Nelson, J Lee

    2015-01-01

    Background Pregnancy induces drastic biological changes systemically, and has a beneficial effect on some autoimmune conditions such as rheumatoid arthritis (RA). However, specific systemic changes that occur as a result of pregnancy have not been thoroughly examined in healthy women or women wit...

  19. [Clinical and experimental studies on the pathogenesis in pregnancy induced hypertension].

    Science.gov (United States)

    Hidaka, A

    1988-08-01

    Placental ischemia is one of the etiological factors of pregnancy induced hypertension (PIH), however, the pathogenesis of placental and renal ischemia has not been clarified. The purposes of this investigation are (1) to clarify the fetomaternal hemodynamic changes in PIH and the influence of maternal postural change on fetomaternal hemodynamics, measured by thermodilution method, impedance cardiography and pulsed doppler method during pregnancy, (2) to provide to relationship between intrauterine resting tonus and maternal hemodynamics, that is, blood pressure, placental and renal blood flow measured by electromagnetic flowmeter and thermocouple method, and renal nerve activity, and (3) to study the influence of placental ischemia on vascular sensitivity to angiotensin II measured by Magnus method in animal experiment. (1) The increase in C.O and blood volume were recognized from the beginning of pregnancy to 24 GW, and subsequently, the decreasing tendency were found from about 32 GW to the onset of labor. However this decreasing tendency were subsided in the lateral position. These circulatory changes were observed in both normotensive and PIH cases, and especially, the decrease in C.O and blood volume in late pregnancy were more remarkable in PIH than that in normotensive pregnancy. From the results of Starling curve, left ventricular work was more hyperdynamic status in PIH than that in normotensive pregnancy, these results show that there are a compensatory mechanism against high vascular resistance in PIH. A/B (S/D) ratio in uterine artery, umbilical artery and fetal aorta were lowered in II-nd and III-rd trimester and more decreased in the lateral position from the supine position, on the other hand these ratio in PIH were elevated respectively. These results show that there are the aortocaval compression by the heavy tensive uterus and subsequent sluice flow mechanism in fetoplacental circulation in the supine position in late pregnancy. (2) These

  20. Mice: progesterone and the regulation of strain differences in pregnancy-induced nest building.

    Science.gov (United States)

    Broida, J; Svare, B

    1983-12-01

    Pregnant DBA/2J females built significantly larger and more completely enclosed nests than did pregnant C57BL/6J mice. This strain difference was restricted to the last half of gestation and was not observed during either the virgin state or lactation. Genotype-based differences in pregnancy-induced nest building were not related to circulating levels of progesterone (P), core temperature, or body weight. Exposure to supplemented P during pregnancy elevated nest building exhibited by pregnant C57BL females but did not induce DBA-like levels of the behavior. Also, virgin DBA females built larger nests in response to P than did C57BL females. These findings suggest that differences in the sensitivity of central neural tissue to steroid hormones may account for genotypically determined variation in patterns of pregnancy-induced nest building.

  1. Pregnancy-induced rise in serum C-peptide concentrations in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Rehfeld, Jens F; Pedersen-Bjergaard, Ulrik

    2009-01-01

    OBJECTIVE: The purpose of this study was to investigate whether pregnancy induces increased insulin production as a marker of improved beta-cell function in women with long-term type 1 diabetes. RESEARCH DESIGN AND METHODS: This was a prospective study of 90 consecutive pregnant women with type 1.......85). Multivariate regression analysis revealed a positive association between the absolute increase in C-peptide concentrations during pregnancy and decreased A1C from 8 to 33 weeks (P = 0.003). CONCLUSIONS: A pregnancy-induced increase in C-peptide concentrations in women with long-term type 1 diabetes...... in 35 women. RESULTS: C-peptide concentrations gradually increased throughout pregnancy regardless of serum glucose concentrations in the 90 women with a median duration of diabetes of 17 years (range 1-36 years). Among 35 women with paired recordings of stimulated C-peptide, C-peptide production...

  2. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  3. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  4. Pregnancy-induced adaptations in the intrinsic structure of rat pelvic floor muscles.

    Science.gov (United States)

    Alperin, Marianna; Lawley, Danielle M; Esparza, Mary C; Lieber, Richard L

    2015-08-01

    Maternal birth trauma to the pelvic floor muscles (PFMs) is a major risk factor for pelvic floor disorders. Modeling and imaging studies suggest that demands placed on PFMs during childbirth exceed their physiologic limits; however many parous women do not sustain PFM injury. Here we determine whether pregnancy induces adaptations in PFM architecture, the strongest predictor of muscle function, and/or intramuscular extracellular matrix (ECM), responsible for load bearing. To establish if parallel changes occur in muscles outside of the PFM, we also examined a hind limb muscle. Coccygeus, iliocaudalis, pubocaudalis, and tibialis anterior of 3-month-old Sprague-Dawley virgin, mid-pregnant, and late-pregnant; 6-month-old virgin; and 4- and 12-week postpartum rats (N = 10/group) were fixed in situ and harvested. Major architectural parameters determining muscle's excursion and force-generating capacity were quantified, namely, normalized fiber length (Lfn), physiologic cross-sectional area, and sarcomere length. Hydroxyproline content was used as a surrogate for intramuscular ECM quantity. Analyses were performed by 2-way analysis of variance with Tukey post hoc testing at a significance level of .05. Pregnancy induced a significant increase in Lfn in all PFMs by the end of gestation relative to virgin controls. Fibers were elongated by 37% in coccygeus (P pregnancy. By 12 weeks' postpartum, Lfn of all PFMs returned to the prepregnancy values. Relative to virgin controls, ECM increased by 140% in coccygeus, 52% in iliocaudalis, and 75% in pubocaudalis in late-pregnant group, but remained unchanged across time in the tibialis anterior. Postpartum, ECM collagen content returned to prepregnancy levels in iliocaudalis and pubocaudalis, but continued to be significantly elevated in coccygeus (P pregnancy induces unique adaptations in the structure of the PFMs, which adjust their architectural design by adding sarcomeres in series to increase fiber length as well as mounting

  5. Postural Effect on Renal Function In Cases of Pregnancy-Induced Hypertension

    OpenAIRE

    丸山, 晋司; Maruyama, Shinji

    1989-01-01

    Postual effect on renal function was analysed on the cases of pregnancy-induced hypertension (PIH) (n=11) compared with cases of normotensive pregnancies (n=12) and non-pregnant women (n=9). In non-pregnant women, GFR, RBF and RPF showed no changes in relation to the changing posture (supine and left lateral). In normal pregnant women and cases of PIH, GFR, RBF and RPF significantly increased on changing their posture from supine to left lateral at third trimester. Especially, patients with P...

  6. Ultrasonographic Optic Nerve Sheath Diameter as a Surrogate Measure of Raised Intracranial Pressure in Severe Pregnancy-induced Hypertension Patients.

    Science.gov (United States)

    Singh, Shiv Kumar; Bhatia, Kiran

    2018-01-01

    It is a well-known fact that severe pregnancy-induced hypertension (PIH) can be disastrous at times as it can cause a lot of complications to both pregnant women and her baby. Hence, it is always desirable to know the extent of severity by a real-time and easily accessible modality like ultrasound. The aim of the study was to evaluate the incidence of raised intracranial pressure (ICP) in severe preeclampsia and eclampsia patients using ocular ultrasonography with optic nerve sheath diameter (ONSD) measurement. This study design was a prospective and clinically controlled blinded observational study. After taking necessary permissions from the Institution Ethical Committee, 75 patients were enrolled for the study. However, finally, 25 patients in severe preeclampsia and 24 in eclampsia group were compared with 25 normal term antenatal women. Demographic profiles, hemodynamic parameters, laboratory markers for severity of PIH, and ultrasonographic OSND were measured. They were statistically analyzed and compared using one-way ANOVA and Tukey's test. Value of P surrogate marker for raised ICP in severe PIH patients. It is a rapid, bedside, noninvasive, and readily accessible tool and could be a part of a holistic approach for managing such patients.

  7. Assessment of Both Maternal and Fetal Ghrelin and Resistin Levels in Pregnancy Induced Hypertension

    International Nuclear Information System (INIS)

    Khattab, N.F.; El-Nashar, N.A.; Marei, E.S.

    2010-01-01

    Pregnancy-induced hypertension (PIH) is mainly a vascular disease, probably caused by an imbalance between vasodilator and vasoconstrictor agents that results in generalized vasospasm and poor perfusion in many organs including the placenta. The current study was carried out on 55 women, fourty were pregnant and delivered by Elective Cesarean Section, 20 of them were normal healthy pregnant women with uncomplicated term singleton gestation and twenty with PIH. Fifteen were healthy non pregnant women (24-33 years old) served as control group. Active total serum ghrelin (pg/ml) and serum resistin (ng/ml) were measured using ELISA kits. At 25 weeks of gestational age, a highly significant decrease in ghrelin levels in the pregnant groups was detected compared to the non-pregnant group (p<0.0001). Comparing serum ghrelin levels between both pregnant groups showed that it was significantly higher in PIH pregnant women (p<0.05). However, serum resistin showed significant increase in pregnant women compared to the non pregnant. At time of delivery, ghrelin was found to be significantly higher in PIH patients (47.41±8.55 pg/ml) than in normal pregnant women (36.74±6.74 pg/ml). However no significant change was found in serum ghrelin and resistin concentrations in the umbilical cord blood between the previous 2 groups. A significant increase in the umbilical cord blood of ghrelin (41.82±6.30 pg/ml) was detected compared to maternal ghrelin (36.74±6.74 pg/ml) in normal pregnant women (p<0.05), but not in PIH pregnant women. However, a significant increase was detected in the umbilical cord blood of resistin in both normal and PIH pregnant groups compared to their corresponding maternal blood (p< 0.05). In normal pregnant women, serum ghrelin concentration was negatively correlated with both the systolic and diastolic blood pressure (systolic: p<0.05, diastolic: p<0.05). Furthermore, serum ghrelin concentration was also negatively correlated with the systolic blood

  8. Impact of road traffic pollution on pre-eclampsia and pregnancy-induced hypertensive disorders

    DEFF Research Database (Denmark)

    Pedersen, Marie; Halldorsson, Thorhallur I.; Olsen, Sjurdur F.

    2017-01-01

    addresses. Outcome and covariate data were derived from registries, hospital records, and questionnaires. RESULTS: A 10-µg/m increase in NO2 exposure during first trimester was associated with increased risk of preeclampsia (n=1,880, adjusted odds ratio = 1.07 [95% confidence interval = 1.01 to 1.......14]) and pregnancy-induced hypertensive disorders (n=2,430, 1.07 [1.01 to 1.13]). A 10-dBhigher road traffic noise was also associated with increased risk of preeclampsia (1.10 [1.02 to 1.18]) and pregnancy-induced hypertensive disorders (1.08 [1.02 to 1.15]). For both exposures the associations were strongest...... for mild preeclampsia (n=1,393) and early-onset preeclampsia (n=671) while higher risk for severe preeclampsia(n=487) was not evident. In mutually adjusted models estimates for both exposures decreased and only the association between NO2 and mild preeclampsia remained. CONCLUSIONS: Road traffic may...

  9. Association of angiotensin receptor 2 gene polymorphisms with pregnancy induced hypertension risk.

    Science.gov (United States)

    Li, Chenyang; Peng, Weijun; Zhang, Heng; Yan, Weirong

    2018-05-01

    To investigate the association of polymorphisms and haplotypes of angiotensin receptor 2 (AT2R) gene with pregnancy induced hypertension (PIH) in Chinese Han women. A case-control study was designed with 446 cases (gestational hypertension, GH: 124; pre-eclampsia, PE + eclampsia, E: 322) and 650 controls. rs5193, rs1403543 and rs12710567 of AT2R gene were genotyped. A logistic regression approach was applied to estimate the relationship between the polymorphisms and haplotypes of AT2Rgene with PIH risk. No relationship between AT2R gene polymorphisms and PIH was detected. The haplotype analysis also showed a negative result. rs5193, rs1403543 and rs12710567 of AT2R gene might have no effect on PIH risk among Chinese Han women.

  10. Anaesthetic management of splenectomy in Evan′s syndrome during pregnancy with pregnancy induced hypertension.

    Directory of Open Access Journals (Sweden)

    Sherke R

    2001-07-01

    Full Text Available The management of idiopathic thrombocytopenic purpura (ITP during pregnancy, especially with ongoing bleeding diathesis, has not been highlighted sufficiently in the literature. Aortocaval compression and reduction in uteroplacental circulation resulting in foetal hypoxia and acidosis, Mendelson′s syndrome due to gravid uterus, trauma to airway with resultant haemorrhage and aspiration into lungs, compromised airway due to short neck, anasarca and heavy breast, limitation in using invasive monitoring and regional anaesthesia and uncontrolled bleeding leading to placental hypoperfusion and foetal hypoxia are some of the important risks. In the present case report, anaesthetic management for splenectomy during pregnancy complicated with pregnancy induced hypertension and bleeding diathesis secondary to ITP is described with reference to above risks.

  11. SOCS3 deficiency in leptin receptor-expressing cells mitigates the development of pregnancy-induced metabolic changes

    Directory of Open Access Journals (Sweden)

    Thais T. Zampieri

    2015-03-01

    Conclusions: Our study identified the increased hypothalamic expression of SOCS3 as a key mechanism responsible for triggering pregnancy-induced leptin resistance and metabolic adaptations. These findings not only help to explain a common phenomenon of the mammalian physiology, but it may also aid in the development of approaches to prevent and treat gestational metabolic imbalances.

  12. Pregnancy-induced gene expression changes in vivo among women with rheumatoid arthritis: a pilot study.

    Science.gov (United States)

    Goin, Dana E; Smed, Mette Kiel; Pachter, Lior; Purdom, Elizabeth; Nelson, J Lee; Kjærgaard, Hanne; Olsen, Jørn; Hetland, Merete Lund; Zoffmann, Vibeke; Ottesen, Bent; Jawaheer, Damini

    2017-05-25

    Little is known about gene expression changes induced by pregnancy in women with rheumatoid arthritis (RA) and healthy women because the few studies previously conducted did not have pre-pregnancy samples available as baseline. We have established a cohort of women with RA and healthy women followed prospectively from a pre-pregnancy baseline. In this study, we tested the hypothesis that pregnancy-induced changes in gene expression among women with RA who improve during pregnancy (pregDAS improved ) overlap substantially with changes observed among healthy women and differ from changes observed among women with RA who worsen during pregnancy (pregDAS worse ). Global gene expression profiles were generated by RNA sequencing (RNA-seq) from 11 women with RA and 5 healthy women before pregnancy (T0) and at the third trimester (T3). Among the women with RA, eight showed an improvement in disease activity by T3, whereas three worsened. Differential expression analysis was used to identify genes demonstrating significant changes in expression within each of the RA and healthy groups (T3 vs T0), as well as between the groups at each time point. Gene set enrichment was assessed in terms of Gene Ontology processes and protein networks. A total of 1296 genes were differentially expressed between T3 and T0 among the 8 pregDAS improved women, with 161 genes showing at least two-fold change (FC) in expression by T3. The majority (108 of 161 genes) were also differentially expressed among healthy women (qexpression between the pregDAS improved and pregDAS worse groups, all of which were inducible by type I interferon (IFN). These IFN-inducible genes were over-expressed at T3 compared to the T0 baseline among the pregDAS improved women. In our pilot RNA-seq dataset, increased pregnancy-induced expression of type I IFN-inducible genes was observed among women with RA who improved during pregnancy, but not among women who worsened. These findings warrant further investigation into

  13. HEMODYNAMIC DOPPLER PARAMETERS IN THE FETUS FETOPLACENTAL UNIT WITH INTRAUTERINE GROWTH RESTRICTIONWITHIN PREGNANCY INDUCED HYPERTENSION

    Directory of Open Access Journals (Sweden)

    Snezana Stamenovic

    2005-04-01

    Full Text Available Based on the spectral analysis of Doppler velocity waveform in uteroplacental and fetoplacental circulation, a Doppler parameters diagnostic efficiency was examined in fetus prenatal detection with intrauterine growth restriction (IUGR within Pregnancy Induced Hypertension (PIH and their respiratory menace.A prospective analysis was performed in 141 third-trimester pregnancies. The control group included 65 normal pregnancies and the expeimental group included 76 high-risk pregnancies, which was divided into three sub-groups, namely, 31 with IUGR within PIH, 24 with PIH only and 21 with IUGR only. The uterine artery was examined in uteroplacental circulation and umbilical artery was examined in fetoplacental circulation. Perinatal outcome and birth weight were recorded in each case.Uteroplacental circulation analysis showed statistically higer values of Pourcelot resistance index Ri in uterine artery in IUGR within PIH pregnancies. Statistically higher pulsatility index in umbilical artery was recorded in IUGR pregnancies compared to the control group and PIH subgroup. Higher values of pulsatility index were particulary noticed in IUGR within PIH subgroup. Doppler parameters in uteroplacental and fetoplacental circulation showed a significant negative correlation in relation to Apgar score of the newborn.In combination with biophysical profile and CTG, Doppler parameters diagnostic efficiency is increased on the evaluation of the fetus respiratory menace with IUGR and PIH.

  14. Determination of plasma adrenomedullin in normal pregnant women and pregnancy-induced hypertension patients

    International Nuclear Information System (INIS)

    Ruan Lihong; Li Jingbo; Zhu Fengquan; Pan Yu; Yuan Aijun; He Kai

    2004-01-01

    Objective: To study the relationships between plasma adrenomedullin (ADM) and normal pregnancy and pathogenesis of pregnancy-induced hypertension (PIH). Methods: ADM concentrations in the plasma from 10 normal non-pregnant women, 36 normal pregnant women (12 first, 12 second, 12 third trimester, respectively) and 30 cases of PIH (10 mild, 10 moderate, 10 severe, respectively) were determined by radioimmunoassay, and data were analyzed statistically. Results: ADM concentrations in the first, second and third trimester of normal pregnancy increased significantly than that of normal non-pregnant women (P<0.05). ADM concentration in the plasma of patients with PIH was higher than that of third trimester pregnancy (P<0.01). There were significant differences between mild, moderate, and severe PIH groups (P<0.05). In the PIH groups, significant positive correlation was found between plasma ADM concentration and mean arterial pressure (r=0.822, P<0.05). Incidence of low birth weight infants was related to serious degree of PIH. Conclusion: ADM may involve in maintaining normal human pregnancy. ADM may increase compensatorily in the pathogenesis of PIH

  15. Effect of raised serum uric acid level on perinatal and maternal outcome in cases of pregnancy-induced hypertension

    Directory of Open Access Journals (Sweden)

    Qumrun Nassa Ahmed

    2017-05-01

    Full Text Available The aim of this study was to find out the effects of raised serum uric acid level on perinatal and maternal outcome in cases of pregnancy-induced hypertension. One hundred pregnant women with gestational period beyond 28 weeks with pregnancy-induced hypertension-preeclampsia and eclampsia were included in this study and divided into two groups. Group A (n=65 patients with a serum uric acid level >6 mg/dL was compared to Group B (n=35 patients with a uric acid level <6 gm/dL. It revealed that high uric acid level in patients with pregnancy-induced hypertension was a risk factor for several maternal complications like postpartum hemorrhage (Group A, 17.4%; Group B, 22.6%, postpartum eclampsia (Group A, 10.1%; Group B, 9.7%, abruptio placentae (Group A, 8.7%; Group B, 6.4%, HELLP syndrome (Group A, 2.9%; Group B, 0% and pulmonary edema (Group A, 4.3%; Group B, 0%. In case of perinatal outcome, the birth weight, intrauterine growth retardation, intrauterine death, stillbirth and neonatal death rate were worse in Group A 1.9 kg, 66.7, 19, 7 and 8% in comparison to Group B, where those were 2.1, 13, 6, 2, and 2% respectively. In conclusion, high uric acid in blood in patient with hypertensive disorders in pregnancy is a risk factor for several maternal complications.

  16. Maternal hyperinsulinism and glycaemic status in the first trimester of pregnancy are associated with the development of pregnancy-induced hypertension and gestational diabetes.

    LENUS (Irish Health Repository)

    Kayemba-Kay's, Simon

    2013-03-01

    To evaluate the relationships across a range of glucose and insulin measures at 12 weeks of gestation with the development of pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM) and birth size.

  17. Risks for Gestational Diabetes Mellitus and Pregnancy-Induced Hypertension Are Increased in Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Yunhui Wang

    2013-01-01

    Full Text Available Objectives. To evaluate pregnancy outcomes and its determinants in women with polycystic ovary syndrome (PCOS. Methods. Two-hundred and twenty pregnant PCOS and 594 healthy women were followed from early pregnancy. Incidences of gestational diabetes mellitus (GDM, pregnancy-induced hypertension (PIH, preterm birth, twinning, and fetal growth restriction (FGR were determined. Results. The incidence of GDM was notably higher among all PCOS combined (54.9%; OR: 2.9, 95% CI: 2.0–4.1 and PCOS subgroups, whether they conceived spontaneously (51.5%; OR: 3.3, 95% CI: 2.0–5.4, or via IVF-ET or ovarian stimulation, compared with controls (14.3%; P<0.001. The incidence of PIH was also higher among all PCOS (10.4%; OR: 2.2, 95% CI: 1.1–4.4 and the subgroup conceiving spontaneously (11.8%; OR: 2.6, 95% CI: 1.1–6.2; P<0.001 but not for those conceiving with IVF-ET (9.1% or ovarian stimulation (9.4%. Lean women with PCOS (BMI <24 kg/m2 had higher incidences of GDM (51.1% versus 14.5%; OR: 5.6, 95% CI: 3.4–9.0 and PIH (8.9% versus 3.2%; OR: 3.0, 95% CI: 1.3–7.1 than lean controls. PCOS woemn with normal glucose tolerance had higher risk for PIH than their comparable control group (OR: 4.0, 95% CI: 1.3–11.7. Conclusion. This study suggested that PCOS is an independent risk factor for the development of GDM and PIH. This trial is registered with ChiCTR-RCC-11001824.

  18. High-sodium intake prevents pregnancy-induced decrease of blood pressure in the rat.

    Science.gov (United States)

    Beauséjour, Annie; Auger, Karine; St-Louis, Jean; Brochu, Michéle

    2003-07-01

    Despite an increase of circulatory volume and of renin-angiotensin-aldosterone system (RAAS) activity, pregnancy is paradoxically accompanied by a decrease in blood pressure. We have reported that the decrease in blood pressure was maintained in pregnant rats despite overactivation of RAAS following reduction in sodium intake. The purpose of this study was to evaluate the impact of the opposite condition, e.g., decreased activation of RAAS during pregnancy in the rat. To do so, 0.9% or 1.8% NaCl in drinking water was given to nonpregnant and pregnant Sprague-Dawley rats for 7 days (last week of gestation). Increased sodium intakes (between 10- and 20-fold) produced reduction of plasma renin activity and aldosterone in both nonpregnant and pregnant rats. Systolic blood pressure was not affected in nonpregnant rats. However, in pregnant rats, 0.9% sodium supplement prevented the decreased blood pressure. Moreover, an increase of systolic blood pressure was obtained in pregnant rats receiving 1.8% NaCl. The 0.9% sodium supplement did not affect plasma and fetal parameters. However, 1.8% NaCl supplement has larger effects during gestation as shown by increased plasma sodium concentration, hematocrit level, negative water balance, proteinuria, and intrauterine growth restriction. With both sodium supplements, decreased AT1 mRNA levels in the kidney and in the placenta were observed. Our results showed that a high-sodium intake prevents the pregnancy-induced decrease of blood pressure in rats. Nonpregnant rats were able to maintain homeostasis but not the pregnant ones in response to sodium load. Furthermore, pregnant rats on a high-sodium intake (1.8% NaCl) showed some physiological responses that resemble manifestations observed in preeclampsia.

  19. Pregnancy-Induced Changes in Systemic Gene Expression among Healthy Women and Women with Rheumatoid Arthritis.

    Directory of Open Access Journals (Sweden)

    Anuradha Mittal

    Full Text Available Pregnancy induces drastic biological changes systemically, and has a beneficial effect on some autoimmune conditions such as rheumatoid arthritis (RA. However, specific systemic changes that occur as a result of pregnancy have not been thoroughly examined in healthy women or women with RA. The goal of this study was to identify genes with expression patterns associated with pregnancy, compared to pre-pregnancy as baseline and determine whether those associations are modified by presence of RA.In our RNA sequencing (RNA-seq dataset from 5 healthy women and 20 women with RA, normalized expression levels of 4,710 genes were significantly associated with pregnancy status (pre-pregnancy, first, second and third trimesters over time, irrespective of presence of RA (False Discovery Rate (FDR-adjusted p value<0.05. These genes were enriched in pathways spanning multiple systems, as would be expected during pregnancy. A subset of these genes (n = 256 showed greater than two-fold change in expression during pregnancy compared to baseline levels, with distinct temporal trends through pregnancy. Another 98 genes involved in various biological processes including immune regulation exhibited expression patterns that were differentially associated with pregnancy in the presence or absence of RA.Our findings support the hypothesis that the maternal immune system plays an active role during pregnancy, and also provide insight into other systemic changes that occur in the maternal transcriptome during pregnancy compared to the pre-pregnancy state. Only a small proportion of genes modulated by pregnancy were influenced by presence of RA in our data.

  20. Amplification caused by gravitational bending of light

    International Nuclear Information System (INIS)

    Schneider, P.

    1985-01-01

    Gravitational bending of light may not only lead to multiple imaging (gravitational lens effect), but also affects the apparent luminosity of a source. It is shown here that a mass distribution near the line-of-sight to any source always increases the observable flux relative to the case in which the deflector is absent

  1. [Clinical study of hemostatic coagulation markers in prethrombosis state of pregnancy induced hypertension].

    Science.gov (United States)

    Shi, Qing; Chen, Chen; Wang, Xue-Feng; Wang, Hong-Li

    2004-11-01

    To investigate the relationship between the hemostatic coagulation markers of prethrombosis state and pregnancy induced hypertension (PIH). Forty-five PIH patients and 20 control patients were studied. P-selectin, prothrombin fragments 1 + 2 (F1+2), D-dimers (D-D) and plasmin-antiplasmin complex (PAP) were measured by enzyme linked immunosorbent assay. Antithrombin activity (AT: A) was measured by chromogenic peptide substrate assay. (1) The P-selectin level of pre-delivery in moderate and severe PIH patients was (66 +/- 24) microg/L and (80 +/- 30) microg/L, it was (49 +/- 15) microg/L in the control group (both P post partum in severe PIH group and control group was (65 +/- 34) microg/L and (40 +/- 12) microg/L, with significant difference between them (P < 0.05). (2) The F1+2 level of pre-delivery in mild, moderate and severe PIH groups was respectively (2.2 +/- 0.2), (2.3 +/- 0.4) and (2.2 +/- 0.2) nmol/L, being all significantly higher than that in the control group, which was (1.2 +/- 0.3) nmol/L, but there was no obvious difference between three PIH groups. (3) The D-D level in mild, moderate and severe PIH groups was respectively (0.7 +/- 0.1), (0.7 +/- 0.3) and (0.8 +/- 0.2) mg/L, and it was (0.4 +/- 0.1) mg/L in the control group. The D-D level was increased when PIH became severe. (4) The PAP level in moderate and severe PIH groups was (0.8 +/- 0.4) mg/L and (0.8 +/- 0.4) mg/L, being significantly higher than that in control group (0.7 +/- 0.3) mg/L (both P < 0.05). (5) The AT: Aactivity was obviously decreased in PIH groups, being respectively (44 +/- 37)%, (64 +/- 25)% and (83 +/- 39)% in severe, moderate and mild PIH groups. There was obvious difference between severe and mild groups (P < 0.01). Elevated P-selectin levels and increased platelet activity were observed in PIH patients. F1+2 may be useful as a screening test for risk pregnancy. D-D can be used as an early monitor of DIC. AT: A reflects the severity of illness. These molecular markers may

  2. Ambient air pollutant PM10 and risk of pregnancy-induced hypertension in urban China

    International Nuclear Information System (INIS)

    Huang, Xin; Qiu, Jie; Qiu, Weitao; He, Xiaochun; Wang, Yixuan; Sun, Qingmei; Cui, Hongmei; Liu, Sufen; Tang, Zhongfeng; Chen, Ya; Yue, Li; Da, Zhenqiang; Lv, Ling; Lin, Xiaojuan; Zhang, Chong; Zhang, Honghong; Xu, Ruifeng; Zhu, Daling; Zhang, Yaqun; Zhao, Nan

    2015-01-01

    Background: The relationship between air borne particulate matter ≤10 μm (PM 10 ) exposure and pregnancy-induced hypertension (PIH) is inconclusive. Few studies have been conducted, and fewer were conducted in areas with high levels of PM 10 . Methods: To examine the association between PM 10 and PIH by different exposure time windows during pregnancy, we analyzed data from a birth cohort study conducted in Lanzhou, China including 8 745 pregnant women with available information on air pollution during pregnancy. A total of 333 PIH cases (127 gestational hypertension (GH) and 206 preeclampsia (PE)) were identified. PM 10 daily average concentrations of each subject were calculated according to the distance between home/work addresses and monitor stations using an inverse-distance weighting approach. Results: Average PM 10 concentration over the duration of entire pregnancy was significantly associated with PIH (OR = 1.12, 95%CI: 1.02, 1.23 per 10 μg m −3 increase), PE (OR = 1.16, 95%CI: 1.03, 1.30 per 10 μg m −3 increase), late onset PE (OR = 1.17, 95% CI: 1.03, 1.32 per10 μg m −3 increase), and severe PE (OR = 1.25, 95% CI: 1.06, 1.48 per 10 μg m −3 increase). Average PM 10 during the first 12 gestational weeks was associated with the risk of GH (OR = 1.10, 95% CI: 1.00, 1.21 per 10 μg m −3 increase), and PM 10 exposure before 20 gestational weeks was associated with the risk of severe PE (OR = 1.14, 95% CI: 1.01, 1.30 per 10 μg m −3 increase). Conclusions: We found that high level exposure to ambient PM 10 during pregnancy was associated with an increased risk of PIH, GH and PE and that the strength of the association varied by timing of exposure during pregnancy. (letter)

  3. Gene amplification in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Lucimari Bizari

    2006-01-01

    Full Text Available Gene amplification increases the number of genes in a genome and can give rise to karyotype abnormalities called double minutes (DM and homogeneously staining regions (HSR, both of which have been widely observed in human tumors but are also known to play a major role during embryonic development due to the fact that they are responsible for the programmed increase of gene expression. The etiology of gene amplification during carcinogenesis is not yet completely understood but can be considered a result of genetic instability. Gene amplification leads to an increase in protein expression and provides a selective advantage during cell growth. Oncogenes such as CCND1, c-MET, c-MYC, ERBB2, EGFR and MDM2 are amplified in human tumors and can be associated with increased expression of their respective proteins or not. In general, gene amplification is associated with more aggressive tumors, metastases, resistance to chemotherapy and a decrease in the period during which the patient stays free of the disease. This review discusses the major role of gene amplification in the progression of carcinomas, formation of genetic markers and as possible therapeutic targets for the development of drugs for the treatment of some types of tumors.

  4. Social amplification of risk

    International Nuclear Information System (INIS)

    Kasperson, R.E.; Renn, O.; Slovic, P.; Kasperson, J.X.; Emani, S.

    1989-01-01

    The risks associated with radioactive and other hazardous waste disposal may be expected to interact with societal processes to enlarge or attenuate the consequences of risks and risk events. This article summarizes a conceptual framework that depicts the social amplification of risk. Using a data base of 128 hazard events that have occurred largely over the past ten years, the authors examine the role of physical consequences, media coverage, and public perceptions of risk in generating social and economic impacts. The analysis concludes that social amplification processes substantially shape the nature and magnitude of those impacts but also that such social amplification appears to be systematically related to characteristics of the risks and risk events

  5. Centrosome Amplification Is Sufficient to Promote Spontaneous Tumorigenesis in Mammals

    NARCIS (Netherlands)

    Levine, Michelle S.; Bakker, Bjorn; Boeckx, Bram; Moyett, Julia; Lu, James; Vitre, Benjamin; Spierings, Diana C.; Lansdorp, Peter M.; Cleveland, Don W.; Lambrechts, Diether; Foijer, Floris; Holland, Andrew J.

    2017-01-01

    Centrosome amplification is a common feature of human tumors, but whether this is a cause or a consequence of cancer remains unclear. Here, we test the consequence of centrosome amplification by creating mice in which centrosome number can be chronically increased in the absence of additional

  6. Clinical significance of determination of the changes of plasma vasoactive substances ET, NO, CGRP levels in patients with pregnancy induced hypertension

    International Nuclear Information System (INIS)

    Zhang Danhui

    2006-01-01

    Objective: To investigate the clinical significance of changes of plasma ET, CGRP and NO levels in patients with pregnancy induced hypertension. Methods: Plasma levels of ET, CGRP (with RIA) and NO (with colorimetry) were measured in 36 patients with pregnancy induced hypertension 30 women with normal pregnancy and 32 controls. Results: Plasma levels of ET, CGRP and NO in normal pregnant women were not significantly different from those in controls (P>0.05) and plasma levels of ET, CGRP and NO in patients with mild pregnancy induced hypertension (n=12) were not significantly different flora those in normal pregnant women (P>0.05), However, plasma levels of ET in patients with moderate (n=14) and severe (n=10) pregnancy induced hypertension were significantly higher than those in normal pregant women, while levels of CGRP and NO were significantly lower (all P< 0.01). Conclusion: Detection of changes of plasma ET, CGRP and NO contents in patients with pregnancy induced hypertension provides a valuable laboratory basis for study of relationship between endothelial cell function and pathogenesis of hypertension. (authors)

  7. Clinical significance of changes of plasma ET, NO, THcy and cystatin C levels in patients with pregnancy induced hypertension (PIH)

    International Nuclear Information System (INIS)

    Yu Qiuyue

    2009-01-01

    Objective: To investigate the relationship between development of illness and changes of plasma endothelin (ET) nitric oxide (NO), total homocysteine (THcy) and Cystatin C (Cyst C) levels in patients with pregnancy induced Hypertension. Methods: Plasma levels of ET, THcy (with RIA), NO (with chemical Greiss method) and Cyst C (with particle enhanced) immunoneph-elometric assay (PETIA) in 32 patients with PIH, 35 non-pregnant women and 35 normal pregnant women. Results: The plasma ET, NO levels were significantly higher in 35 normal pregnant women than those in the healthy non-pregnantwomen (all P 0.05). Plasma ET levels and THcy, Cyst C levels were mutually positivety correlated (r=0.6097, 0.7213, all P<0.01), while the plasma ET levels and NO levels were negatively correlated (r=0.5812, P<0.01). Conclusion: Determination of changes of plasma ET, NO, THcy and Cyst C levels in patients with Pregnancy induced Hypertension were helpful for disease mechanism elucidation and outcome prediction. (authors)

  8. Biomaterials in light amplification

    Science.gov (United States)

    Mysliwiec, Jaroslaw; Cyprych, Konrad; Sznitko, Lech; Miniewicz, Andrzej

    2017-03-01

    Biologically produced or inspired materials can serve as optical gain media, i.e. they can exhibit the phenomenon of light amplification. Some of these materials, under suitable dye-doping and optical pumping conditions, show lasing phenomena. The emerging branch of research focused on obtaining lasing action in highly disordered and highly light scattering materials, i.e. research on random lasing, is perfectly suited for biological materials. The use of biomaterials in light amplification has been extensively reported in the literature. In this review we attempt to report on progress in the development of biologically derived systems able to show the phenomena of light amplification and random lasing together with the contribution of our group to this field. The rich world of biopolymers modified with molecular aggregates and nanocrystals, and self-organized at the nanoscale, offers a multitude of possibilities for tailoring luminescent and light scattering properties that are not easily replicated in conventional organic or inorganic materials. Of particular importance and interest are light amplification and lasing, or random lasing studies in biological cells and tissues. In this review we will describe nucleic acids and their complexes employed as gain media due to their favorable optical properties and ease of manipulation. We will report on research conducted on various biomaterials showing structural analogy to nucleic acids such as fluorescent proteins, gelatins in which the first distributed feedback laser was realized, and also amyloids or silks, which, due to their dye-doped fiber-like structure, allow for light amplification. Other materials that were investigated in that respect include polysaccharides, like starch exhibiting favorable photostability in comparison to other biomaterials, and chitosan, which forms photonic crystals or cellulose. Light amplification and random lasing was not only observed in processed biomaterials but also in living

  9. Clinical significance of measurement of changes of serum TNF-α, IL-6 and IL-8 centent after treatment in patients with pregnancy induced hypertension (PIH)

    International Nuclear Information System (INIS)

    Wang Guiying

    2008-01-01

    Objective: To explore the clinical significance of changes of serum TNF-α, IL-6 and IL-8 levels in patients with pregnancy induced hypertension. Methods: Serum TNF-α, IL-6 and IL-8 levels were measured with RIA in 36 patients with pregnancy induced hypertension both before and after 2 weeks of treatment as well as in 35 controls. Results: Before treatment, the serum TNF-α, IL-6 and IL-8 levels were significantly higher in patients with PIH than those in the controls (P 0.05). Conclusion: The inflammatory cytokines such as TNF-α, IL-6 and IL-8 may play important roles in the pathogenesis of pregnancy induced hypertension. (authors)

  10. Pregnancy-Induced Hypertensive Disorders before and after a National Economic Collapse: A Population Based Cohort Study.

    Directory of Open Access Journals (Sweden)

    Védís Helga Eiríksdóttir

    Full Text Available Data on the potential influence of macroeconomic recessions on maternal diseases during pregnancy are scarce. We aimed to assess potential change in prevalence of pregnancy-induced hypertensive disorders (preeclampsia and gestational hypertension during the first years of the major national economic recession in Iceland, which started abruptly in October 2008.Women whose pregnancies resulted in live singleton births in Iceland in 2005-2012 constituted the study population (N = 35,211. Data on pregnancy-induced hypertensive disorders were obtained from the Icelandic Medical Birth Register and use of antihypertensive drugs during pregnancy, including β-blockers and calcium channel blockers, from the Icelandic Medicines Register. With the pre-collapse period as reference, we used logistic regression analysis to assess change in pregnancy-induced hypertensive disorders and use of antihypertensives during the first four years after the economic collapse, adjusting for demographic and pregnancy characteristics, taking aggregate economic indicators into account. Compared with the pre-collapse period, we observed an increased prevalence of gestational hypertension in the first year following the economic collapse (2.4% vs. 3.9%; adjusted odds ratio [aOR] 1.47; 95 percent confidence interval [95%CI] 1.13-1.91 but not in the subsequent years. The association disappeared completely when we adjusted for aggregate unemployment rate (aOR 1.04; 95% CI 0.74-1.47. Similarly, there was an increase in prescription fills of β-blockers in the first year following the collapse (1.9% vs.3.1%; aOR 1.43; 95% CI 1.07-1.90, which disappeared after adjusting for aggregate unemployment rate (aOR 1.05; 95% CI 0.72-1.54. No changes were observed for preeclampsia or use of calcium channel blockers between the pre- and post-collapse periods.Our data suggest a transient increased risk of gestational hypertension and use of β-blockers among pregnant women in Iceland in the

  11. The relationship between the leptin levels in pregnancy-induced hypertension women and the weight of newborns

    International Nuclear Information System (INIS)

    Duan Yuling; Zhang Xuefeng

    2007-01-01

    To explore the relationship between the serum leptin levels in patients with pregnancy-induced hypertension (PIH) and normal pregnant women and the weight of their newborns. The serum leptin levels in 158 pregnant women were determined by RIA. The results showed that serum liptin levels in patients with PIH group (30.74±9.6 ng/mL) were markedly higher than that in the normal pregnant group(17.3±6.2 ng/mL, P<0.01). The levels of serum leptin in patients with severe PIH group (39.7±9.2 ng/mL)were higher than that in patients with moderate-PIH group (31.24±6.5 ng/mL, P<0.05) and mild-PIH group(23.9±7.1 ng/mL,P <0.01). The weight of their newborns in patients with PIH group (3012±338g) were significantly lower than that in the normal pregnant group (3479±557g, P<0.01). The weight of newborns in patients with severe-PIH group (2454±299)were more lower than that in patients with moderate-PIH group (2998±316g, P<0.01) and mild-PIH group (3412±321g, P< 0.01). The measurement of serum leptin levels in pregnant women might be regarded as clinical significance for predicting the weight of newborns, treatment and prognosis of patients with pregnancy-induced hypertension. (authors)

  12. The effect of magnesium on maternal blood pressure in pregnancy-induced hypertension. A randomized double-blind placebo-controlled trial

    DEFF Research Database (Denmark)

    Rudnicki, M; Frölich, A; Rasmussen, W F

    1991-01-01

    The effects of magnesium were compared with those of placebo in a randomized double-blind controlled study of 58 patients with pregnancy-induced hypertension, of whom 27 received magnesium and 31 placebo. Twenty patients in each group were nulliparas. The treatment comprised 48 h of either intrav...

  13. 4G/5G Variant of Plasminogen Activator Inhibitor-1 Gene and Severe Pregnancy-Induced Hypertension: Subgroup Analyses of Variants of Angiotensinogen and Endothelial Nitric Oxide Synthase

    Science.gov (United States)

    Kobashi, Gen; Ohta, Kaori; Yamada, Hideto; Hata, Akira; Minakami, Hisanori; Sakuragi, Noriaki; Tamashiro, Hiko; Fujimoto, Seiichiro

    2009-01-01

    Background Pregnancy-induced hypertension (PIH) is a common cause of perinatal mortality. It is believed to result from the interaction of several factors, including those related to the blood coagulation system. We performed genotyping and subgroup analyses to determine if the 4G/5G genotypes of the plasminogen activator inhibitor-1 gene (PAI-1) play a role in the pathogenesis of PIH, and to evaluate possible interactions of the PAI-1 polymorphisms with those of the angiotensinogen gene (AGT) and the endothelial nitric oxide synthase gene (NOS3). Methods An association study of PAI-1 polymorphism, and subgroup analyses of common variants of AGT and NOS3, among 128 patients with PIH and 376 healthy pregnant controls. Results No significant differences were found between the cases and controls in the frequencies of allele 4G or the 4G/4G genotype. In subgroup analyses, after adjustment for multiple comparison, a significant association with the AGT TT genotype was found among women with the PAI-1 4G/4G genotype, and an association with the NOS3 GA+AA genotype was found among women with the 5G/5G or 4G/5G genotypes. Conclusions Our findings suggest that there are at least 2 pathways in the pathogenesis of severe PIH. However, with respect to early prediction and prevention of severe PIH, although the PAI-1 4G/4G genotype alone was not a risk factor for severe PIH, the fact that PAI-1 genotypes are associated with varying risks for severe PIH suggests that PAI-1 genotyping of pregnant women, in combination with other tests, may be useful in the development of individualized measures that may prevent severe PIH. PMID:19838007

  14. Sex differences in early growth during the first three years of life in offspring from mothers with pregnancy-induced hypertension.

    Science.gov (United States)

    Mitsui, Takashi; Masuyama, Hisashi; Eguchi, Takeshi; Tamada, Shoko; Eto, Eriko; Hayata, Kei; Hiramatsu, Yuji

    2016-10-01

    Newborns born to mothers with pregnancy-induced hypertension (PIH) are thought to be at high risk for lifestyle-related diseases, such as obesity and hypertension, in adulthood. A longitudinal study of 78 pregnant women with PIH and their newborns, who visited Okayama University Hospital from 2009 to 2013. We investigated the change in growth of offspring born to mothers with PIH and compared it with the standard growth curve in Japanese to examine whether there was rapid catch-up growth during the first 3years of life. Subjects were 78 pregnant women with PIH and their offspring, who visited Okayama University Hospital from 2009 to 2013. Valid responses were obtained from 29 of 78 (37.1%) women. Body weight and length at birth were at the third percentile or less in females, and at the 10th percentile or less, in males. When body weight and length were compared at 6months, 18months, and 3years old between male and female toddlers, male toddlers slowly caught up until 3years old, but female toddlers rapidly caught up in the first 6months. Furthermore, in newborns with fetal growth restriction caused by the intrauterine environment of PIH, differences in physical development between male and female toddlers were more remarkable. There is a significant sex difference in catch-up growth during the first 3years, which might be involved in lifestyle-related diseases in adulthood, suggesting continuous follow-up is necessary, especially for female offspring. Copyright © 2016 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

  15. Evidence of high-elevation amplification versus Arctic amplification.

    Science.gov (United States)

    Wang, Qixiang; Fan, Xiaohui; Wang, Mengben

    2016-01-12

    Elevation-dependent warming in high-elevation regions and Arctic amplification are of tremendous interest to many scientists who are engaged in studies in climate change. Here, using annual mean temperatures from 2781 global stations for the 1961-2010 period, we find that the warming for the world's high-elevation stations (>500 m above sea level) is clearly stronger than their low-elevation counterparts; and the high-elevation amplification consists of not only an altitudinal amplification but also a latitudinal amplification. The warming for the high-elevation stations is linearly proportional to the temperature lapse rates along altitudinal and latitudinal gradients, as a result of the functional shape of Stefan-Boltzmann law in both vertical and latitudinal directions. In contrast, neither altitudinal amplification nor latitudinal amplification is found within the Arctic region despite its greater warming than lower latitudes. Further analysis shows that the Arctic amplification is an integrated part of the latitudinal amplification trend for the low-elevation stations (≤500 m above sea level) across the entire low- to high-latitude Northern Hemisphere, also a result of the mathematical shape of Stefan-Boltzmann law but only in latitudinal direction.

  16. A mechanism of gene amplification driven by small DNA fragments.

    Directory of Open Access Journals (Sweden)

    Kuntal Mukherjee

    Full Text Available DNA amplification is a molecular process that increases the copy number of a chromosomal tract and often causes elevated expression of the amplified gene(s. Although gene amplification is frequently observed in cancer and other degenerative disorders, the molecular mechanisms involved in the process of DNA copy number increase remain largely unknown. We hypothesized that small DNA fragments could be the trigger of DNA amplification events. Following our findings that small fragments of DNA in the form of DNA oligonucleotides can be highly recombinogenic, we have developed a system in the yeast Saccharomyces cerevisiae to capture events of chromosomal DNA amplification initiated by small DNA fragments. Here we demonstrate that small DNAs can amplify a chromosomal region, generating either tandem duplications or acentric extrachromosomal DNA circles. Small fragment-driven DNA amplification (SFDA occurs with a frequency that increases with the length of homology between the small DNAs and the target chromosomal regions. SFDA events are triggered even by small single-stranded molecules with as little as 20-nt homology with the genomic target. A double-strand break (DSB external to the chromosomal amplicon region stimulates the amplification event up to a factor of 20 and favors formation of extrachromosomal circles. SFDA is dependent on Rad52 and Rad59, partially dependent on Rad1, Rad10, and Pol32, and independent of Rad51, suggesting a single-strand annealing mechanism. Our results reveal a novel molecular model for gene amplification, in which small DNA fragments drive DNA amplification and define the boundaries of the amplicon region. As DNA fragments are frequently found both inside cells and in the extracellular environment, such as the serum of patients with cancer or other degenerative disorders, we propose that SFDA may be a common mechanism for DNA amplification in cancer cells, as well as a more general cause of DNA copy number variation

  17. Efficient Audio Power Amplification - Challenges

    DEFF Research Database (Denmark)

    Andersen, Michael Andreas E.

    2005-01-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where...

  18. Efficient audio power amplification - challenges

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Michael A.E.

    2005-07-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where extensive research and development are needed is covered. (au)

  19. Fetal exposure to herpesviruses may be associated with pregnancy-induced hypertensive disorders and preterm birth in a Caucasian population.

    Science.gov (United States)

    Gibson, C S; Goldwater, P N; MacLennan, A H; Haan, E A; Priest, K; Dekker, G A

    2008-03-01

    To investigate the role of fetal viral infection in the development of a range of adverse pregnancy outcomes (APOs), including pregnancy-induced hypertensive disorders (PIHD), antepartum haemorrhage (APH), birthweight PTBs, the risk of developing PIHD was increased in the presence of DNA from Herpes PCR group B viruses (OR 3.57, 95% CI 1.10-11.70), CMV (OR 3.89, 95% CI 1.67-9.06), any herpesvirus (OR 5.70, 95% CI 1.85-17.57) and any virus (OR 5.17, 95% CI 1.68-15.94). The presence of CMV was associated with PTB (OR 1.61, 95% CI 1.14-2.27). No significant association was observed between SGA or APH and exposure to viral infection. Fetal exposure to herpesvirus infection was associated with PIHD for both term and PTBs in this exploratory study. Exposure to CMV may also be associated with PTB. These findings need confirmation in future studies.

  20. PREVALENCE, CLINICAL PRESENTATION, DIAGNOSIS AND TREATMENT OF ACUTE PULMONARY OEDEMA IN SEVERE PREGNANCY-INDUCED HYPERTENSION AND ECLAMPSIA CASES IN TRIBAL POPULATION OF SOUTH RAJASTHAN

    Directory of Open Access Journals (Sweden)

    (Brig. Pradeep Kuma

    2016-05-01

    Full Text Available BACKGROUND Pulmonary oedema in severe pregnancy-induced hypertension is a life threatening complication with high maternal mortality, particularly in tribal population of South Rajasthan. METHODS Thirteen cases which occurred in the duration of two and half years were analysed through medical records and findings were recorded. RESULTS Maximum cases 10(76.92% were in less than 20 years of age. 12 (92.30% cases were nulliparous. Out of 13 cases of PIH, pulmonary oedema developed in 5 (38.46% cases of eclampsia and 8 (61.54% cases of severe pregnancy-induced hypertension. 10 (76.92%cases were 28 to 30 weeks of gestation and 3 (23.08% were 31 to 34 weeks of gestation. 8 (61.54% cases were severely anaemic. 12 (92.30% were unbooked cases. CONCLUSION Regular antenatal checkups, early diagnosis, prompt treatment of hypertension and pulmonary oedema and termination of pregnancy is required to prevent maternal death.

  1. Parent-offspring conflict and the persistence of pregnancy-induced hypertension in modern humans

    DEFF Research Database (Denmark)

    Hartsteen, Birgitte Hollegaard; Byars, Sean Geoffrey; Lykke, Jacob

    2013-01-01

    Preeclampsia is a major cause of perinatal mortality and disease affecting 5-10% of all pregnancies worldwide, but its etiology remains poorly understood despite considerable research effort. Parent-offspring conflict theory suggests that such hypertensive disorders of pregnancy may have evolved...... towards the end of pregnancy in order to explain why these disorders have not been removed by natural selection in our hunter-gatherer ancestors. We analyzed >750,000 live births in the Danish National Patient Registry and all registered medical diagnoses for up to 30 years after birth. We show...... that early PIH leading to improved postpartum survival and health represents a balanced compromise between the reproductive interests of parents and offspring, whereas later onset of PIH may reflect an unbalanced parent-offspring conflict at the detriment of maternal and offspring health....

  2. Magnesium supplement in pregnancy-induced hypertension: effects on maternal and neonatal magnesium and calcium homeostasis

    DEFF Research Database (Denmark)

    Rudnicki, M; Frølich, A; Fischer-Rasmussen, W

    1991-01-01

    The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double-blind man......The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double...... period despite a significant increased loss of calcium during the first 24 h of inclusion. Low dose maternal magnesium treatment did not cause neonatal hypocalcemia....

  3. Radiation-induced gene amplification in rodent and human cells

    International Nuclear Information System (INIS)

    Luecke-Huhle, C.; Gloss, B.; Herrlich, P.

    1990-01-01

    Ionizing and UV radiations induce amplification of SV40 DNA sequences integrated in the genome of Chinese hamster cells and increase amplification of the dihydrofolate reductase (DHFR) gene during methotrexate selection in human skin fibroblasts of a patient with ataxia telangiectasia. Various types of external (60-Co-γ-rays, 241-Am-α-particles, UV) or internal radiation (caused by the decay of 125 I incorporated into DNA in form of I-UdR) were applied. By cell fusion experiments it could be shown that SV40 gene amplification is mediated by one or several diffusible trans-acting factors induced or activated in a dose dependent manner by all types of radiation. One of these factors binds to a 10 bp sequence within the minimal origin of replication of SV40. In vivo competition with an excess of a synthetic oligonucleotide comprising this sequence blocks radiation-induced amplification. (author) 25 refs.; 8 figs

  4. DNAzyme Feedback Amplification: Relaying Molecular Recognition to Exponential DNA Amplification.

    Science.gov (United States)

    Liu, Meng; Yin, Qingxin; McConnell, Erin M; Chang, Yangyang; Brennan, John D; Li, Yingfu

    2018-03-26

    Technologies capable of linking DNA amplification to molecular recognition are very desirable for ultrasensitive biosensing applications. We have developed a simple but powerful isothermal DNA amplification method, termed DNAzyme feedback amplification (DFA), that is capable of relaying molecular recognition to exponential DNA amplification. The method incorporates both an RNA-cleaving DNAzyme (RCD) and rolling circle amplification (RCA) carried out by a special DNA polymerase using a circular DNA template. DFA begins with a stimulus-dependent RCA reaction, producing tandemly linked RCDs in long-chain DNA products. These RCDs cleave an RNA-containing DNA sequence to form additional primers that hybridize to the circular DNA molecule, giving rise to DNA assemblies that act as the new inputs for RCA. The RCA reaction and the cleavage event keep on feeding each other autonomously, resulting in exponential growth of repetitive DNA sequences that can be easily detected. This method can be used for the detection of both nucleic acid based targets and non-nucleic acid analytes. In this article, we discuss the conceptual framework of the feedback amplification approach, the essential features of this method as well as remaining challenges and possible solutions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Next generation Chirped Pulse Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Nees, J; Biswal, S; Mourou, G [Univ. Michigan, Center for Ultrafast Optical Science, Ann Arbor, MI (United States); Nishimura, Akihiko; Takuma, Hiroshi

    1998-03-01

    The limiting factors of Chirped Pulse Amplification (CPA) are discussed and experimental results of CPA in Yb:glass regenerative amplifier are given. Scaling of Yb:glass to the petawatt level is briefly discussed. (author)

  6. Pregnancy-Induced Hypertension

    Science.gov (United States)

    ... is born very early, it may have serious health problems. But your doctor may want your baby to be delivered early ... PIH: High blood pressure is not the main problem, but it is one of the main ... dying. Many doctors give magnesium sulfate to their patients during labor ...

  7. Genome position and gene amplification

    Czech Academy of Sciences Publication Activity Database

    Jirsová, Pavla; Snijders, A.M.; Kwek, S.; Roydasgupta, R.; Fridlyand, J.; Tokuyasu, T.; Pinkel, D.; Albertson, D. G.

    2007-01-01

    Roč. 8, č. 6 (2007), r120 ISSN 1474-760X Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : gene amplification * array comparative genomic hybridization * oncogene Subject RIV: BO - Biophysics Impact factor: 6.589, year: 2007

  8. Empirical Site Amplification Factors Incorporating Soil Nonlinearity in Taiwan

    Science.gov (United States)

    Kuo, C. H.; Chung, C. H.; Che-Min, L.; Huang, J. Y.; Wen, K. L.

    2017-12-01

    Characteristics of site amplifications caused by both crustal and subduction earthquakes are important in Taiwan. For example, seismic waves were amplified and led to significant building damages in the Taipei Basin by the 1986 Hualien offshore (subduction interface) and the 1999 Chi-Chi earthquakes (crustal), for which the epicentral distances were about 100 km. To understand local site amplifications in Taiwan, empirical site amplification factors for horizontal ground motions are studied using recently constructed strong motion and site databases for the free-field TSMIP stations in Taiwan. Records of large magnitude earthquakes of ML larger than six from 1994 to 2014 were selected for this study. Site amplification factors at site conditions with Vs30 of 120 m/s to 1500 m/s and base accelerations up to 0.7g were inferred from intensity ratios of station pairs within specific distances. The reference site condition is assumed as Vs30 of 760 m/s (B/C boundary). Preliminary results indicate: 1. Soil nonlinearity is more obviously at short periods (PGA, Sa0.3) than long periods (PGV, Sa1.0). 2. Soil nonlinearity is significant for stations belong to site classes of B, C, D, and E in Taiwan. 3. Effect of station-pair distance is seen at short periods (PGA and Sa0.3). 4. No significant different is found in site amplifications of crustal and subduction earthquakes. The result could be a reference for the Fa and Fv in Taiwan's building code.

  9. Serum cobalt status during pregnancy and the risks of pregnancy-induced hypertension syndrome: A prospective birth cohort study.

    Science.gov (United States)

    Liang, Chunmei; Wang, Jianqing; Xia, Xun; Wang, Qunan; Li, Zhijuan; Tao, Ruiwen; Tao, Yiran; Xiang, Haiyun; Tong, Shilu; Tao, Fangbiao

    2018-03-01

    Cobalt (Co) is an essential trace element and has been suggested to be involved in blood pressure regulation, but few studies have focused on serum Co status during pregnancy and the risks of pregnancy-induced hypertension syndrome (PIH). The aim of this study was to prospectively assess the association between serum Co levels during pregnancy and the risks of PIH, and to explore how the maternal Co status contributes to the incidence of PIH. 3260 non-hypertensive women before pregnancy with singleton births in Ma'anShan birth cohort study (MABC) were recruited with the assessment of maternal Co concentrations, additionally, the levels of 7 inflammatory factors and 3 stress factors in placentas were also determined. Relative risks (RRs) [95% confidence intervals (CIs)] for the risks of PIH were assessed and the relationships between 10 factors and maternal Co status during pregnancy were evaluated as well. A total of 194 (5.95%) women were diagnosed with PIH. The concentrations of Co varied from the first trimester to the second trimester, and maternal serum Co concentrations during pregnancy were negatively associated with the incidence of PIH in a linear fashion. There was a clear trend in RRs according to decreasing exposure to Co levels in the second trimester (RR a =1.80, 95% CI (1.26, 2.56); RR b =1.73, 95% CI (1.21, 2.46) and RR c =1.43, 95% CI (1.02, 2.04) when low Co levels comparing with high Co levels before and after adjustment for confounders; and RR a =1.29, 95% CI (0.88, 1.88); RR b =1.28, 95% CI (0.87, 1.87) and RR c =1.25, 95% CI (0.86, 1.82) when medium Co levels comparing with high Co levels before and after adjustment for confounders). In addition, the trend for the first trimester was nearly identifical to those for the second trimester (RR a =1.35, 95% CI (0.94, 1.93); RR b =1.33, 95% CI (0.93, 1.91); RR c =1.22, 95%CI (0.86, 1.73) when low Co levels comparing with high Co levels before and after adjustment for confounders; and RR a =1.10, 95

  10. Miniaturized isothermal nucleic acid amplification, a review.

    Science.gov (United States)

    Asiello, Peter J; Baeumner, Antje J

    2011-04-21

    Micro-Total Analysis Systems (µTAS) for use in on-site rapid detection of DNA or RNA are increasingly being developed. Here, amplification of the target sequence is key to increasing sensitivity, enabling single-cell and few-copy nucleic acid detection. The several advantages to miniaturizing amplification reactions and coupling them with sample preparation and detection on the same chip are well known and include fewer manual steps, preventing contamination, and significantly reducing the volume of expensive reagents. To-date, the majority of miniaturized systems for nucleic acid analysis have used the polymerase chain reaction (PCR) for amplification and those systems are covered in previous reviews. This review provides a thorough overview of miniaturized analysis systems using alternatives to PCR, specifically isothermal amplification reactions. With no need for thermal cycling, isothermal microsystems can be designed to be simple and low-energy consuming and therefore may outperform PCR in portable, battery-operated detection systems in the future. The main isothermal methods as miniaturized systems reviewed here include nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), helicase-dependent amplification (HDA), rolling circle amplification (RCA), and strand displacement amplification (SDA). Also, important design criteria for the miniaturized devices are discussed. Finally, the potential of miniaturization of some new isothermal methods such as the exponential amplification reaction (EXPAR), isothermal and chimeric primer-initiated amplification of nucleic acids (ICANs), signal-mediated amplification of RNA technology (SMART) and others is presented.

  11. Clinical significance of determination of changes of serum TNF-α levels, peripheral B lymphocyte count and T lymphocyte subsets distribution pattern in patients with pregnancy induced hypertension syndrome

    International Nuclear Information System (INIS)

    Zhao Wenjuan

    2006-01-01

    Objective: To explore the changes of serum TNF-α levels, peripheral B cell count and T subsets distribution pattern in patients with pregnancy induced hypertension syndrome. Methods: Serum TNF-α levels (with RIA), peripheral B cell count as well as T subsets (with monoclonal technique) were examined in 34 patients with pregnancy induced hypertension syndrome and 35 controls. Results: The serum TNF-α levels and B lymphocytes count were significantly higher than those in controls (P 3 , CD 4 , CD4/CD8 ratio were significantly lower than those in controls (P<0.01). Conclusion: Pregnancy induced hY- pertension syndrome is a kind of autoimmune diseases with abnormal immunoregulation. (authors)

  12. Laser amplification in excited dielectrics

    Science.gov (United States)

    Winkler, Thomas; Haahr-Lillevang, Lasse; Sarpe, Cristian; Zielinski, Bastian; Götte, Nadine; Senftleben, Arne; Balling, Peter; Baumert, Thomas

    2018-01-01

    Wide-bandgap dielectrics such as glasses or water are transparent at visible and infrared wavelengths. This changes when they are exposed to ultrashort and highly intense laser pulses. Different interaction mechanisms lead to the appearance of various transient nonlinear optical phenomena. Using these, the optical properties of dielectrics can be controlled from the transparent to the metal-like state. Here we expand this range by a yet unexplored mechanism in excited dielectrics: amplification. In a two-colour pump-probe experiment, we show that a 400 nm femtosecond laser pulse is coherently amplified inside an excited sapphire sample on a scale of a few micrometres. Simulations strongly support the proposed two-photon stimulated emission process, which is temporally and spatially controllable. Consequently, we expect applications in all fields that demand strongly localized amplification.

  13. Measuring the amplification of attention

    OpenAIRE

    Blaser, Erik; Sperling, George; Lu, Zhong-Lin

    1999-01-01

    An ambiguous motion paradigm, in which the direction of apparent motion is determined by salience (i.e., the extent to which an area is perceived as figure versus ground), is used to assay the amplification of color by attention to color. In the red–green colored gratings used in these experiments, without attention instructions, salience depends on the chromaticity difference between colored stripes embedded in the motion sequence and the yellow background. Selective attention to red (or to ...

  14. Spheromak Impedance and Current Amplification

    International Nuclear Information System (INIS)

    Fowler, T K; Hua, D D; Stallard, B W

    2002-01-01

    It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, τ REC , which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI TOR 2 /dt ∼ I 2 /τ REC - I TOR 2 /τ closed where I is the gun current, I TOR is the spheromak toroidal current and τ CLOSED is the ohmic decay time of the spheromak. Achieving high current amplification, I TOR >> I, requires τ REC CLOSED . For resistive reconnection, this requires reconnection in a cold zone feeding helicity into a hot zone. Here we propose an impedance model based on these ideas in a form that can be implemented in the Corsica-based helicity transport code. The most important feature of the model is the possibility that τ REC actually increases as the spheromak temperature increases, perhaps accounting for the ''voltage sag'' observed in some experiments, and a tendency toward a constant ratio of field to current, B ∝ I, or I TOR ∼ I. Program implications are discussed

  15. Protein Misfolding Cyclic Amplification of Infectious Prions.

    Science.gov (United States)

    Moda, Fabio

    2017-01-01

    Transmissible spongiform encephalopathies, or prion diseases, are a group of incurable disorders caused by the accumulation of an abnormally folded prion protein (PrP Sc ) in the brain. According to the "protein-only" hypothesis, PrP Sc is the infectious agent able to propagate the disease by acting as a template for the conversion of the correctly folded prion protein (PrP C ) into the pathological isoform. Recently, the mechanism of PrP C conversion has been mimicked in vitro using an innovative technique named protein misfolding cyclic amplification (PMCA). This technology represents a great tool for studying diverse aspects of prion biology in the field of basic research and diagnosis. Moreover, PMCA can be expanded for the study of the misfolding process associated to other neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and frontotemporal lobar degeneration. © 2017 Elsevier Inc. All rights reserved.

  16. Relationship between changes of plasma endothelin (ET) level, ATPase activity of erythrocyte membrane and development of nephropathy in patients with pregnancy induced hypertension

    International Nuclear Information System (INIS)

    Qin Lin; Lu Beiyi

    2008-01-01

    Objective: To investigate the possible role played by alteration of plasma ET levels and activities of Na + - K + -APT ase and Ca 2+ -Mg 2+ -ATPase of erythrocyte membrane in patients with nephropathy pregnancy induced hypertension. Methods: The concentrations of plasma ET was detected with RIA and erythrocyte membrane ATPase activities were determined with Reilni method in 32 pregnant women with PIH complicated with nephropathy and 70 women with PIH but no nephropathy and 35 normal pregnant women as controls. Results: The plasma ET levels in patients with PHI (both with and without nephropathy) were significantly higher than those in normal preganat women (P + -K + -ATPase and Ca 2+ -Mg 2+ -ATPase levels were significantly de- creased (P + -K + -ATPase and Ca 2+ -Mg 2+ -ATPase activity of erythrocyte membrane. (authors)

  17. Clinical significance of determination of changes of serum Hcy, ET and BNP levels After treatment in patients with pregnancy induced hypertension (PIH)

    International Nuclear Information System (INIS)

    He Hongling

    2010-01-01

    Objective: To study the clinical significance of changes of serum Hcy, ET and BNP levels after treatment in patients with pregnancy induced hypertension(PIH). Methods: Serum Hcy (with ELISA), ET and BNP (with RIA) levels were determined in 32 patients with PIH both before and after treatment as well as in 35 controls. Results: Before treatment, serum Hcy, ET and BNP levels in patients with PIH were significantly higher than those in controls (P < 0.01). After 1 month of treatment the levels dropped markedly, but still remained significantly higher(P < 0.05). Conclusion: Serum Hcy, ET and BNP levels were closely related to the diseases process of PIH and were of prognostic values. (authors)

  18. Pregnancy induces transcriptional activation of the peripheral innate immune system and increases oxidative DNA damage among healthy third trimester pregnant women.

    Directory of Open Access Journals (Sweden)

    Xinyin Jiang

    Full Text Available BACKGROUND: Pregnancy induces physiological adaptations that may involve, or contribute to, alterations in the genomic landscape. Pregnancy also increases the nutritional demand for choline, an essential nutrient that can modulate epigenomic and transcriptomic readouts secondary to its role as a methyl donor. Nevertheless, the interplay between human pregnancy, choline and the human genome is largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: As part of a controlled feeding study, we assessed the influence of pregnancy and choline intake on maternal genomic markers. Healthy third trimester pregnant (n = 26, wk 26-29 gestation and nonpregnant (n = 21 women were randomized to choline intakes of 480 mg/day, approximating the Adequate Intake level, or 930 mg/day for 12-weeks. Blood leukocytes were acquired at study week 0 and study week 12 for microarray, DNA damage and global DNA/histone methylation measurements. A main effect of pregnancy that was independent of choline intake was detected on several of the maternal leukocyte genomic markers. Compared to nonpregnant women, third trimester pregnant women exhibited higher (P<0.05 transcript abundance of defense response genes associated with the innate immune system including pattern recognition molecules, neutrophil granule proteins and oxidases, complement proteins, cytokines and chemokines. Pregnant women also exhibited higher (P<0.001 levels of DNA damage in blood leukocytes, a genomic marker of oxidative stress. No effect of choline intake was detected on the maternal leukocyte genomic markers with the exception of histone 3 lysine 4 di-methylation which was lower among pregnant women in the 930 versus 480 mg/d choline intake group. CONCLUSIONS: Pregnancy induces transcriptional activation of the peripheral innate immune system and increases oxidative DNA damage among healthy third trimester pregnant women.

  19. Laser amplification in excited dielectrics

    DEFF Research Database (Denmark)

    Winkler, Thomas; Haahr-Lillevang, Lasse; Sarpe, Cristian

    2018-01-01

    Wide-bandgap dielectrics such as glasses or water are transparent at visible and infrared wavelengths. This changes when they are exposed to ultrashort and highly intense laser pulses. Different interaction mechanisms lead to the appearance of various transient nonlinear optical phenomena. Using...... these, the optical properties of dielectrics can be controlled from the transparent to the metal-like state. Here we expand this range by a yet unexplored mechanism in excited dielectrics: amplification. In a two-colour pump-probe experiment, we show that a 400nm femtosecond laser pulse is coherently...

  20. Telomerase Repeated Amplification Protocol (TRAP).

    Science.gov (United States)

    Mender, Ilgen; Shay, Jerry W

    2015-11-20

    Telomeres are found at the end of eukaryotic linear chromosomes, and proteins that bind to telomeres protect DNA from being recognized as double-strand breaks thus preventing end-to-end fusions (Griffith et al. , 1999). However, due to the end replication problem and other factors such as oxidative damage, the limited life span of cultured cells (Hayflick limit) results in progressive shortening of these protective structures (Hayflick and Moorhead, 1961; Olovnikov, 1973). The ribonucleoprotein enzyme complex telomerase-consisting of a protein catalytic component hTERT and a functional RNA component hTR or hTERC - counteracts telomere shortening by adding telomeric repeats to the end of chromosomes in ~90% of primary human tumors and in some transiently proliferating stem-like cells (Shay and Wright, 1996; Shay and Wright, 2001). This results in continuous proliferation of cells which is a hallmark of cancer. Therefore, telomere biology has a central role in aging, cancer progression/metastasis as well as targeted cancer therapies. There are commonly used methods in telomere biology such as Telomere Restriction Fragment (TRF) (Mender and Shay, 2015b), Telomere Repeat Amplification Protocol (TRAP) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this detailed protocol we describe Telomere Repeat Amplification Protocol (TRAP). The TRAP assay is a popular method to determine telomerase activity in mammalian cells and tissue samples (Kim et al. , 1994). The TRAP assay includes three steps: extension, amplification, and detection of telomerase products. In the extension step, telomeric repeats are added to the telomerase substrate (which is actually a non telomeric oligonucleotide, TS) by telomerase. In the amplification step, the extension products are amplified by the polymerase chain reaction (PCR) using specific primers (TS upstream primer and ACX downstream primer) and in the detection step, the presence or absence of telomerase is

  1. Resonant primordial gravitational waves amplification

    Directory of Open Access Journals (Sweden)

    Chunshan Lin

    2016-01-01

    Full Text Available We propose a mechanism to evade the Lyth bound in models of inflation. We minimally extend the conventional single-field inflation model in general relativity (GR to a theory with non-vanishing graviton mass in the very early universe. The modification primarily affects the tensor perturbation, while the scalar and vector perturbations are the same as the ones in GR with a single scalar field at least at the level of linear perturbation theory. During the reheating stage, the graviton mass oscillates coherently and leads to resonant amplification of the primordial tensor perturbation. After reheating the graviton mass vanishes and we recover GR.

  2. Risk Perception and Social Amplification

    International Nuclear Information System (INIS)

    Smith, R.E.

    2001-01-01

    This paper seeks to consider social amplification as it applies to risk perception. Perceptions of the magnitude of a risk are conditioned by issues such as the degree of uncertainty in probability and consequences, the nature of the consequences and the relative weightings placed on probability and consequences. Risk perceptions are also influenced by factors such as confidence in the operator of an industrial process, trust in the regulator and the perceived fairness of regulatory decision-making. Different people may hold different views about these issues and there may also be difficulties in communication. The paper identifies and discusses self-reinforcing mechanisms, which will be labelled 'lock-in' here. They appear to apply in many situations where social amplification is observed. Historically, the term 'lock-in' has been applied mainly in the technological context but, in this paper, four types of lock-in are identified, namely scientific/technological, economic, social and institutional lock-in. One type of lock-in tends to lead to the next and all are buttressed by people's general acceptance of the familiar, fear of the unknown and resistance to change. The regulator seeks to make decisions which achieve the common good rather than supporting or perpetuating any set of vested interests. In this regard the locked-in positions of stakeholders, whether organisations, interest groups, or individual members of the public, are obstacles and challenges. Existing methods of consultation are unsatisfactory in terms of achieving a proper and productive level of dialogue with stakeholders

  3. Multiscale image contrast amplification (MUSICA)

    Science.gov (United States)

    Vuylsteke, Pieter; Schoeters, Emile P.

    1994-05-01

    This article presents a novel approach to the problem of detail contrast enhancement, based on multiresolution representation of the original image. The image is decomposed into a weighted sum of smooth, localized, 2D basis functions at multiple scales. Each transform coefficient represents the amount of local detail at some specific scale and at a specific position in the image. Detail contrast is enhanced by non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients. This yields a uniformly contrast- enhanced image without artefacts. The MUSICA-algorithm is being applied routinely to computed radiography images of chest, skull, spine, shoulder, pelvis, extremities, and abdomen examinations, with excellent acceptance. It is useful for a wide range of applications in the medical, graphical, and industrial area.

  4. Measuring the amplification of attention.

    Science.gov (United States)

    Blaser, E; Sperling, G; Lu, Z L

    1999-09-28

    An ambiguous motion paradigm, in which the direction of apparent motion is determined by salience (i.e., the extent to which an area is perceived as figure versus ground), is used to assay the amplification of color by attention to color. In the red-green colored gratings used in these experiments, without attention instructions, salience depends on the chromaticity difference between colored stripes embedded in the motion sequence and the yellow background. Selective attention to red (or to green) alters the perceived direction of motion and is found to be equivalent to increasing the physical redness (or greenness) by 25-117%, depending on the observer and color. Whereas attention to a color drastically alters the salience of that color, it leaves color appearance unchanged. A computational model, which embodies separate, parallel pathways for object perception and for salience, accounts for 99% of the variance of the experimental data.

  5. Risk Perception and Social Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E. [Environment Agency (United Kingdom)

    2001-07-01

    This paper seeks to consider social amplification as it applies to risk perception. Perceptions of the magnitude of a risk are conditioned by issues such as the degree of uncertainty in probability and consequences, the nature of the consequences and the relative weightings placed on probability and consequences. Risk perceptions are also influenced by factors such as confidence in the operator of an industrial process, trust in the regulator and the perceived fairness of regulatory decision-making. Different people may hold different views about these issues and there may also be difficulties in communication. The paper identifies and discusses self-reinforcing mechanisms, which will be labelled 'lock-in' here. They appear to apply in many situations where social amplification is observed. Historically, the term 'lock-in' has been applied mainly in the technological context but, in this paper, four types of lock-in are identified, namely scientific/technological, economic, social and institutional lock-in. One type of lock-in tends to lead to the next and all are buttressed by people's general acceptance of the familiar, fear of the unknown and resistance to change. The regulator seeks to make decisions which achieve the common good rather than supporting or perpetuating any set of vested interests. In this regard the locked-in positions of stakeholders, whether organisations, interest groups, or individual members of the public, are obstacles and challenges. Existing methods of consultation are unsatisfactory in terms of achieving a proper and productive level of dialogue with stakeholders.

  6. Unmasking cryptococcal meningitis immune reconstitution inflammatory syndrome in pregnancy induced by HIV antiretroviral therapy with postpartum paradoxical exacerbation

    Directory of Open Access Journals (Sweden)

    Reuben Kiggundu

    2014-07-01

    Full Text Available Cryptococcosis is the most common cause of meningitis in Africa due to the high burden of HIV. Immune reconstitution inflammatory syndrome (IRIS is a frequent and deadly complication of cryptococcal meningitis. We report a fatal case of cryptococcal-IRIS in a pregnant woman that began after starting antiretroviral therapy (unmasking IRIS and markedly worsened postpartum after delivery (paradoxical IRIS.

  7. Arctic amplification: does it impact the polar jet stream?

    Directory of Open Access Journals (Sweden)

    Valentin P. Meleshko

    2016-10-01

    Full Text Available It has been hypothesised that the Arctic amplification of temperature changes causes a decrease in the northward temperature gradient in the troposphere, thereby enhancing the oscillation of planetary waves leading to extreme weather in mid-latitudes. To test this hypothesis, we study the response of the atmosphere to Arctic amplification for a projected summer sea-ice-free period using an atmospheric model with prescribed surface boundary conditions from a state-of-the-art Earth system model. Besides a standard global warming simulation, we also conducted a sensitivity experiment with sea ice and sea surface temperature anomalies in the Arctic. We show that when global climate warms, enhancement of the northward heat transport provides the major contribution to decrease the northward temperature gradient in the polar troposphere in cold seasons, causing more oscillation of the planetary waves. However, while Arctic amplification significantly enhances near-surface air temperature in the polar region, it is not large enough to invoke an increased oscillation of the planetary waves.

  8. Recurrent LDL-receptor mutation causes familial ...

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... 3. eaudet . New. Recurrent LDL-receptor mutation causes familial hypercholesterolaemia in ... amplification refractory mutation system (ARMS)" and single- strand conformation .... Location. Afrikaner. Mixed race. ApaLl.

  9. Application of Optical Coherence Tomography and Contrast Sensitivity Test for Observing Fundus Changes of Patients With Pregnancy-Induced Hypertension Syndrome.

    Science.gov (United States)

    Wang, Zhixue; Zou, Yuanyuan; Li, Wenying; Wang, Xueyan; Zhang, Min; Wang, Wenying

    2015-11-01

    This study was aimed to investigate the fundus changes of patients with pregnancy-induced hypertension syndrome (PIHS) using optical coherence tomography (OCT) technology and contrast sensitivity (CS) tests.Ninety-eight patients with PIHS underwent routine eye examinations including vision correction, fundus examination, OCT, and CS tests. The CS test was performed at low, medium, and high frequency, respectively. Moreover, the difference in CS tests between 2 groups was analyzed by independent-samples T test. The Kruskal-Wallis rank sum test and linear regression model were used to detect the correlation of OCT with CS, respectively. Meanwhile Satterthwaite approximate T test was adopted for pairwise comparisons after nonparametric analysis of variance.The OCT test revealed that 56.76% of the examined eyes showed shallow retinal detachment in the macula lutea and around the optic disk. The differences in CS at each spatial frequency between the case and control group were statistically significant (P tests might be valuable methods in observing fundus changes for PIHS patients.

  10. Outcome of singleton preterm small for gestational age infants born to mothers with pregnancy-induced hypertension. A population-based study.

    Science.gov (United States)

    Regev, Rivka H; Arnon, Shmuel; Litmanovitz, Ita; Bauer-Rusek, Sofia; Boyko, Valentina; Lerner-Geva, Liat; Reichman, Brian

    2015-04-01

    Pregnancy-induced hypertension (PIH) has been associated with a decreased risk of infant mortality in small for gestational age (SGA) preterm infants. To evaluate the influence of PIH on mortality and major neonatal morbidities in singleton preterm SGA infants, in the presence and absence of acute pregnancy complications. Population-based observational study of singleton SGA infants, born at 24 to 32 weeks gestation in the period 1995-2010 (n = 2139). Multivariable logistic regression analyses were used to assess the independent effect of PIH on mortality and neonatal morbidities. Acute pregnancy complications comprised premature labor, premature rupture of membranes >6 h, antepartum hemorrhage and clinical chorioamnionitis. In the absence of pregnancy complications, the odds ratio (95% confidence interval) for mortality (0.77; 0.50-1.16), survival without severe neurological morbidity (1.14; 0.79-1.65) and survival without bronchopulmonary dysplasia (BPD) (0.85; 0.59-1.21) were similar in the PIH versus no-PIH groups. In the presence of pregnancy complications, mortality (0.76; 0.40-1.44), survival without severe neurological morbidity (1.16; 0.64-2.12) and survival without BPD (1.04; 0.58-1.86) were also similar in the PIH versus no-PIH groups. PIH was not associated with improved outcome in preterm SGA infants, both in the presence and absence of acute pregnancy complications.

  11. Thrombomodulin, von Willebrand factor and E-selectin as plasma markers of endothelial damage/dysfunction and activation in pregnancy induced hypertension.

    Science.gov (United States)

    Nadar, Sunil K; Al Yemeni, Eman; Blann, Andrew D; Lip, Gregory Y H

    2004-01-01

    Endothelial disturbance (whether activation, dysfunction or damage) is a likely pathogenic mechanism in pre-eclampsia and pregnancy-induced hypertension (PIH). We set out to determine which of three plasma markers of endothelial disturbance, indicating endothelial activation (E-selectin) or damage/dysfunction (von Willebrand factor (vWf), soluble thrombomodulin), would provide the best discriminator of PIH compared to normotensive pregnancy. Cross-sectional study of 36 consecutive women with PIH (age 31+/-6 years) and 36 consecutive women with normotensive pregnancies (age 29+/-5 years) of similar parity. Plasma levels of vWf, E-selectin and thrombomodulin were measured using ELISA. As expected, women with PIH had significantly higher levels of plasma vWf (by 19%, p=0.003), E-selectin (by 40%, p<0.001) and thrombomodulin (by 61%, p=0.01) than normotensive women. However, on stepwise multiple regression analysis, only thrombomodulin was an independent significant predictor of the presence of PIH (p=0.023). We conclude that although vWf, E-selectin and thrombomodulin are all raised in PIH, only thrombomodulin was independently associated with PIH. This molecule could potentially be useful in monitoring and in providing clues in aetiology and pathophysiology, and may have implications for the clinical complications associated with PIH.

  12. Determination of adrenomedullin and endothelin in cord blood and their expressions in umbilical cord vessel of patients with pregnancy-induced hypertension

    International Nuclear Information System (INIS)

    Ruan Lihong; Zhu Fengquan; Wang Xing; Pan Yu

    2004-01-01

    Objective: To investigate the role of adrenomedullin (ADM) and endothelin-1 (ET-1) in the pathogenesis of pregnancy-induced hypertension (PIH). Methods: The plasma concentrations of ADM in human umbilical vein of PIH patients (n=30) and normal late trimester pregnancy women (n=12) were measured by radioimmunoassay. The expressions of ADM and ET-1 in umbilical cord vessel of PIH patients (n=40) and normal late trimester pregnancy women (n=12) were detected by immunohistochemistry (SABC). Results: 1) The plasma concentration of ADM in human umbilical vein of PIH patients was significantly higher than that of normal late trimester pregnancy women (P 0.05). 2) The expression of ADM was found in endothelium and smooth muscle cell of umbilical cord vessel, and it increased with the serious degree of PIH. The expression of ET-1 was only found in endothelium of umbilical cord vessel, and it decreased with the serious degree of PIH. Conclusion: The changes of ADM and ET-1 in umbilical cord plasma and vessel may related to regulation of fetoplacental circulation in PIH

  13. [Obstructive Sleep Apnea Syndrom during pregnancy: prevalence of main symptoms and relationship with Pregnancy Induced-Hypertension and Intra-Uterine Growth Retardation].

    Science.gov (United States)

    Calaora-Tournadre, D; Ragot, S; Meurice, J C; Pourrat, O; D'Halluin, G; Magnin, G; Pierre, F

    2006-04-01

    To investigate the frequency of main symptoms of Obstructive Sleep Apnea Syndrom (OSAS) and their relationship with Pregnancy Induced-Hypertension (PIH) as well as Intrauterine Growth Retardation (IGR) as suggested by recent studies. Four hundred (and) thirty-eight enquiry forms completed during post-partum period were analysed, after exclusion of multiple pregnancies. Collected data were demographic characteristics, obstetrical events, sleep disorders during last trimester, screening of snoring and vigilance troubles with an Epworth score. Forty-five percentages of the patients reported to have habitual snoring during pregnancy. Among these, 85% were non-snorers before pregnancy. Daytime somnolence concerned 84,5% of the population with an Epworth score significatively increased (P<0,0001). The prevalence of PIH was found to be 4,5%, with two apparently independent risk factors: the body mass index (OR=1,1) and an association between snoring and increased vigilance trouble (OR=2,6). No statistical difference was found concerning IGR. SAS symptoms are frequent during pregnancy and snoring appears to be linked with PIH. However, polysomnographic data are not yet sufficient to explain pathophysiological mechanisms and find relevant diagnostic markers during pregnancy.

  14. Measuring regional and district variations in the incidence of pregnancy-induced hypertension in Ghana: challenges, opportunities and implications for maternal and newborn health policy and programmes.

    Science.gov (United States)

    Antwi, Edward; Klipstein-Grobusch, Kerstin; Quansah Asare, Gloria; Koram, Kwadwo A; Grobbee, Diederick; Agyepong, Irene A

    2016-01-01

    The objectives were to assess the quality of health management information system (HMIS) data needed for assessment of local area variation in pregnancy-induced hypertension (PIH) incidence and to describe district and regional variations in PIH incidence. A retrospective review of antenatal and delivery records of 2682 pregnant women in 10 district hospitals in the Greater Accra and Upper West regions of Ghana was conducted in 2013. Quality of HMIS data was assessed by completeness of reporting. The incidence of PIH was estimated for each district. Key variables for routine assessment of PIH such as blood pressure (BP) at antenatal visits, weight and height were 95-100% complete. Fundal height, gestational age and BP at delivery were not consistently reported. The incidence of PIH differed significantly between Greater Accra region (6.1%) and Upper West region (3.2%). Prevalence of obesity among pregnant women in Greater Accra region (13.9%) was significantly higher than that of women in Upper West region (2.2%). More attention needs to be given to understanding local area variations in PIH and possible relationships with urbanisation and lifestyle changes that promote obesity, to inform maternal and newborn health policy. This can be done with good quality routine HMIS data. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  15. Diagnostic Devices for Isothermal Nucleic Acid Amplification

    Directory of Open Access Journals (Sweden)

    Chia-Chen Chang

    2012-06-01

    Full Text Available Since the development of the polymerase chain reaction (PCR technique, genomic information has been retrievable from lesser amounts of DNA than previously possible. PCR-based amplifications require high-precision instruments to perform temperature cycling reactions; further, they are cumbersome for routine clinical use. However, the use of isothermal approaches can eliminate many complications associated with thermocycling. The application of diagnostic devices for isothermal DNA amplification has recently been studied extensively. In this paper, we describe the basic concepts of several isothermal amplification approaches and review recent progress in diagnostic device development.

  16. Diagnostic devices for isothermal nucleic acid amplification.

    Science.gov (United States)

    Chang, Chia-Chen; Chen, Chien-Cheng; Wei, Shih-Chung; Lu, Hui-Hsin; Liang, Yang-Hung; Lin, Chii-Wann

    2012-01-01

    Since the development of the polymerase chain reaction (PCR) technique, genomic information has been retrievable from lesser amounts of DNA than previously possible. PCR-based amplifications require high-precision instruments to perform temperature cycling reactions; further, they are cumbersome for routine clinical use. However, the use of isothermal approaches can eliminate many complications associated with thermocycling. The application of diagnostic devices for isothermal DNA amplification has recently been studied extensively. In this paper, we describe the basic concepts of several isothermal amplification approaches and review recent progress in diagnostic device development.

  17. Clinical significance of changes of plasma endothelin vasoactive factors (ET and NO) as well as serum related interleukin (IL-6 and IL-8) levels in patients with pregnancy induced hypertension (PIH)

    International Nuclear Information System (INIS)

    Chen Ying

    2009-01-01

    Objective: To investigate the clinical etiological significance of changes of plasma endothelin (ET) and nitric oxide (NO) as well as serum interleukin-6 (IL-6) and interleukin-8 (IL-8) levels in patients with pregnancy induced hypertension. Methods: Plasma ET (with RIA), NO (with biochemistry) and serum IL-6, IL-8 (with RIA) levels were measured in 32 pregnant women with PIH, 35 normal pregnant women without PIH and 35 non-pregnant women (as controls). Results: The plasma ET, NO level were significantly higher in normal pregnant women than those in the non-pregnant women controls, while serum levels of IL-6 and IL-8 levels were only slightly higher without significance (P>0.05). Before treatment, the blood ET, IL-6 and IL- 8 levels were significantly higher in patients with pregnancy induced hypertension than those in the control (P<0.01), while plasma levels of NO were significantly decreased (P<0.01), Two weeks after treatment, the plasma ET, NO and serum IL-6 and IL-8 levels were markedly corrected with no significantly differences from those in controls. The ET levels and serum IL-6, IL-8 levels were mutually positively correlated (r=0.6097, 0.7213, P<0.01). Conclusion: Determination of changes of plasma ET and NO, serum IL-6 and IL-8 levels in patients with pregnancy induced hypertension was helpful for outcome prediction. (authors)

  18. Privacy amplification for quantum key distribution

    International Nuclear Information System (INIS)

    Watanabe, Yodai

    2007-01-01

    This paper examines classical privacy amplification using a universal family of hash functions. In quantum key distribution, the adversary's measurement can wait until the choice of hash functions is announced, and so the adversary's information may depend on the choice. Therefore the existing result on classical privacy amplification, which assumes the independence of the choice from the other random variables, is not applicable to this case. This paper provides a security proof of privacy amplification which is valid even when the adversary's information may depend on the choice of hash functions. The compression rate of the proposed privacy amplification can be taken to be the same as that of the existing one with an exponentially small loss in secrecy of a final key. (fast track communication)

  19. Rolling circle amplification of metazoan mitochondrialgenomes

    Energy Technology Data Exchange (ETDEWEB)

    Simison, W. Brian; Lindberg, D.R.; Boore, J.L.

    2005-07-31

    Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.

  20. Associations of ACE I/D, AGT M235T gene polymorphisms with pregnancy induced hypertension in Chinese population: a meta-analysis.

    Science.gov (United States)

    Zhu, Ming; Zhang, Jie; Nie, Shaofa; Yan, Weirong

    2012-09-01

    There have been many studies concerning the associations of angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T polymorphisms with pregnancy induced hypertension (PIH) among Chinese populations. However, the results were inconsistent, prompting the necessity of meta-analysis. Studies published in English and Chinese were mainly searched in EMbase, PubMed and CBM up to January 2012. Twenty-three studies with 3,551 subjects for ACE I/D and seven studies with 1,296 subjects for AGT M235T were included. Significant associations were found between ACE I/D and PIH under dominant, recessive and allelic models. A separate analysis confined to preeclampsia suggested that ACE I/D was associated with preeclampsia under recessive model and allelic model, but not dominant model. Stratified analyses were conducted as meta-regression analysis indicated that the sample size of case group was a significant source of heterogeneity, which suggested no significant association between ACE I/D and PIH in the subgroup of more than 100 cases. Associations were found between AGT M235T and PIH under dominant genetic model (OR = 1.59; 95 %CI: 1.04-2.42), recessive genetic model (OR = 1.60; 95 %CI: 1.07-2.40), and allelic model (OR = 1.40; 95 %CI: 1.17-1.68). No publication bias was found in either meta-analysis. The present meta-analysis suggested significant associations between ACE I/D, AGT M235T and PIH in Chinese populations. However, no significant association was found between ACE I/D and PIH in the subgroup of more than 100 cases. Studies with larger sample sizes are necessary to investigate the associations between gene polymorphisms and PIH in Chinese populations.

  1. Epigallocatechin gallate enhances treatment efficacy of oral nifedipine against pregnancy-induced severe pre-eclampsia: A double-blind, randomized and placebo-controlled clinical study.

    Science.gov (United States)

    Shi, D-D; Guo, J-J; Zhou, L; Wang, N

    2018-02-01

    Oral nifedipine is commonly used to treat pre-eclampsia, one of the most severe complications during pregnancy, but its clinical efficacy is less than ideal. Epigallocatechin gallate (EGCG), a natural compound from green tea, could benefit cardiovascular health especially hypertension. We investigated the clinical efficacy of EGCG, when complemented with oral nifedipine, in treating pre-eclampsia. A total of 350 pregnant women with severe pre-eclampsia were recruited and randomized to receive oral nifedipine, together with placebo (NIF+placebo) or EGCG (NIF+EGCG). The primary treatment outcome was the time needed to control blood pressure and interval time before a new hypertensive crisis, whereas the secondary treatment outcome was the number of treatment doses to effectively control blood pressure, maternal adverse effects and neonatal complications. Comparing NIF+EGCG group to NIF+placebo group, the time needed to control blood pressure was significantly shorter (NIF+EGCG 31.2±16.7 minutes, NIF+placebo 45.3±21.9 minutes; 95% CI 9.7-18.5 minutes), whereas interval time before a new hypertensive crisis was significantly prolonged (NIF+EGCG 7.2±2.9 hours, NIF+placebo 4.1±3.7 hours; 95% CI 2.3-3.9 hours), and the number of treatment dosages needed to effectively control blood pressure was also lower. Between the two treatment groups, no differences in incidence rates of maternal adverse effects or neonatal complications were observed. EGCG is both safe and effective in enhancing treatment efficacy of oral nifedipine against pregnancy-induced severe pre-eclampsia, but formal validation is required prior to its recommendation for use outside of clinical trials. © 2017 John Wiley & Sons Ltd.

  2. SIGNIFICANCE OF LACTATE DEHYDROGENASE AND ASPARTATE TRANSAMINASE AS BIOCHEMICAL MARKERS AND AS PREDICTORS OF SEVERITY OF PREGNANCY-INDUCED HYPERTENSION AND ITS COMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Ramesh Sonowal

    2017-03-01

    Full Text Available BACKGROUND To compare serum Lactate Dehydrogenase (LDH and serum Aspartate Transaminase (AST of normotensive pregnant women with those of preeclamptic and eclamptic women. To determine the relationship of levels of serum lactate dehydrogenase and serum aspartate transaminase with severity of pregnancy-induced hypertension and its complications. MATERIALSAND METHODS The study was carried out on pregnant hypertensive patients attending outpatient department of Obstetrics and Gynaecology department, AMCH, Dibrugarh, Assam from 1 st July 2013 to 30 th June 2014. Normotensive pregnant women were taken as controls. Each serum sample from both the control group as well as study group was estimated for lactate dehydrogenase and aspartate transaminase using standard methods and a comparison is drawn and analysed using t-test and Chi-square test. RESULTS Serum lactate dehydrogenase and serum aspartate transaminase levels were higher in the study group in comparison to the study groups. The mean serum LDH was 198±30.03U/L in control group, whereas in preeclampsia and eclampsia, mean serum levels of LDH were 817±114U/L and 927±108U/L, respectively. The levels of the serum AST were found to be less than 600U/L in normotensive and preeclampsia patients and more than 600 U/L in eclampsia and other complications of PIH. CONCLUSION Serum lactate dehydrogenase and serum aspartate transaminase levels in patients suffering from preeclampsia and its complications are consistently higher compared to the normotensive pregnant patients. To determine the usefulness of inclusion of these enzymes along with other cardiac enzymes in the panel of investigations of pregnant women universally needs further large scale comparative studies.

  3. Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 Triggered Isothermal Amplification for Site-Specific Nucleic Acid Detection.

    Science.gov (United States)

    Huang, Mengqi; Zhou, Xiaoming; Wang, Huiying; Xing, Da

    2018-02-06

    A novel CRISPR/Cas9 triggered isothermal exponential amplification reaction (CAS-EXPAR) strategy based on CRISPR/Cas9 cleavage and nicking endonuclease (NEase) mediated nucleic acids amplification was developed for rapid and site-specific nucleic acid detection. CAS-EXPAR was primed by the target DNA fragment produced by cleavage of CRISPR/Cas9, and the amplification reaction performed cyclically to generate a large number of DNA replicates which were detected using a real-time fluorescence monitoring method. This strategy that combines the advantages of CRISPR/Cas9 and exponential amplification showed high specificity as well as rapid amplification kinetics. Unlike conventional nucleic acids amplification reactions, CAS-EXPAR does not require exogenous primers, which often cause target-independent amplification. Instead, primers are first generated by Cas9/sgRNA directed site-specific cleavage of target and accumulated during the reaction. It was demonstrated this strategy gave a detection limit of 0.82 amol and showed excellent specificity in discriminating single-base mismatch. Moreover, the applicability of this method to detect DNA methylation and L. monocytogenes total RNA was also verified. Therefore, CAS-EXPAR may provide a new paradigm for efficient nucleic acid amplification and hold the potential for molecular diagnostic applications.

  4. [Investigation of RNA viral genome amplification by multiple displacement amplification technique].

    Science.gov (United States)

    Pang, Zheng; Li, Jian-Dong; Li, Chuan; Liang, Mi-Fang; Li, De-Xin

    2013-06-01

    In order to facilitate the detection of newly emerging or rare viral infectious diseases, a negative-strand RNA virus-severe fever with thrombocytopenia syndrome bunyavirus, and a positive-strand RNA virus-dengue virus, were used to investigate RNA viral genome unspecific amplification by multiple displacement amplification technique from clinical samples. Series of 10-fold diluted purified viral RNA were utilized as analog samples with different pathogen loads, after a series of reactions were sequentially processed, single-strand cDNA, double-strand cDNA, double-strand cDNA treated with ligation without or with supplemental RNA were generated, then a Phi29 DNA polymerase depended isothermal amplification was employed, and finally the target gene copies were detected by real time PCR assays to evaluate the amplification efficiencies of various methods. The results showed that multiple displacement amplification effects of single-strand or double-strand cDNA templates were limited, while the fold increases of double-strand cDNA templates treated with ligation could be up to 6 X 10(3), even 2 X 10(5) when supplemental RNA existed, and better results were obtained when viral RNA loads were lower. A RNA viral genome amplification system using multiple displacement amplification technique was established in this study and effective amplification of RNA viral genome with low load was achieved, which could provide a tool to synthesize adequate viral genome for multiplex pathogens detection.

  5. Helicase-dependent amplification of nucleic acids.

    Science.gov (United States)

    Cao, Yun; Kim, Hyun-Jin; Li, Ying; Kong, Huimin; Lemieux, Bertrand

    2013-10-11

    Helicase-dependent amplification (HDA) is a novel method for the isothermal in vitro amplification of nucleic acids. The HDA reaction selectively amplifies a target sequence by extension of two oligonucleotide primers. Unlike the polymerase chain reaction (PCR), HDA uses a helicase enzyme to separate the deoxyribonucleic acid (DNA) strands, rather than heat denaturation. This allows DNA amplification without the need for thermal cycling. The helicase used in HDA is a helicase super family II protein obtained from a thermophilic organism, Thermoanaerobacter tengcongensis (TteUvrD). This thermostable helicase is capable of unwinding blunt-end nucleic acid substrates at elevated temperatures (60° to 65°C). The HDA reaction can also be coupled with reverse transcription for ribonucleic acid (RNA) amplification. The products of this reaction can be detected during the reaction using fluorescent probes when incubations are conducted in a fluorimeter. Alternatively, products can be detected after amplification using a disposable amplicon containment device that contains an embedded lateral flow strip. Copyright © 2013 John Wiley & Sons, Inc.

  6. ESTIMATION OF AMPLIFICATION FACTOR IN EARTHQUAKE ENGINEERING

    Directory of Open Access Journals (Sweden)

    Nazarov Yuriy Pavlovich

    2015-03-01

    Full Text Available The authors are the developers of Odyssey Software (Eurosoft Co. for the analysis of seismological data and computing of seismic loads and their parameters. While communicating with the users of the software, the authors have revealed some uncertainty about both understanding of the term "amplification factor (AF" and calculation of the amplification factor using various methods. In this article, a simple example shows that the determination of the amplification factor as the ratio of the acceleration’s spectrum to the maximal acceleration is derived from the classical definition of AF in the form of the ratio of maximal dynamic displacement to the displacement by the action of static load. Deterministic and probabilistic ap-proaches for the calculating of the AF were discussed. There was an example of AFs calculation and their envelopes for translational and rotational components of seismic impact by using Odyssey Software.

  7. Amplification of hofmeister effect by alcohols.

    Science.gov (United States)

    Xu, Yun; Liu, Guangming

    2014-07-03

    We have demonstrated that Hofmeister effect can be amplified by adding alcohols to aqueous solutions. The lower critical solution temperature behavior of poly(N-isopropylacrylamide) has been employed as the model system to study the amplification of Hofmeister effect. The alcohols can more effectively amplify the Hofmeister effect following the series methanol alcohols and following the series d-sorbitol ≈ xylitol ≈ meso-erythritol alcohols. Our study reveals that the relative extent of amplification of Hofmeister effect is determined by the stability of the water/alcohol complex, which is strongly dependent on the chemical structure of alcohols. The more stable solvent complex formed via stronger hydrogen bonds can more effectively differentiate the anions through the anion-solvent complex interactions, resulting in a stronger amplification of Hofmeister effect. This study provides an alternative method to tune the relative strength of Hofmeister effect besides salt concentration.

  8. Lidar using the backscatter amplification effect

    Science.gov (United States)

    Razenkov, Igor A.; Banakh, Victor A.

    2018-04-01

    Experimental data proving the possibility of lidar measurement of the refractive turbulence strength based on the effect of backscatter amplification (BSA) are reported. It is shown that the values of the amplification factor correlate with the variance of random jitter of optical image of an incoherent light source depending on the value of the structure constant of the air refractive index turbulent fluctuations averaged over the probing path. This paper presents the results of measurements of the BSA factor in comparison with the simultaneous measurements of the BSA peak, which is very narrow and only occurs on the laser beam axis. It is constructed the range-time images of the derivative of the amplification factor gives a comprehensive picture of the location of turbulent zones and their temporal dynamics.

  9. The impact of socio-economic, lifestyle habits, and obesity in developing of pregnancy-induced hypertension in fast-growing country: global comparisons.

    Science.gov (United States)

    Bener, A; Saleh, N M

    2013-01-01

    The aim of the study was to determine the prevalence and associated risk factors of pregnancy-induced hypertension (PIH) in the third trimester of Arab women and their neonatal outcome. A prospective study. Women's Hospital and Maternity Clinics. The study was based on pregnant women in third trimester from the first week of January 2010 to April 2011. A total of 2,056 pregnant women, who had any kind of maternal complications, were approached and 1,608 women (78.2%) expressed their consent to participate in the study. A questionnaire covered variables related to socio-demographic factors, family history, medical history, maternal complications, and neonatal outcome. Multiple logistic regressions were used to describe the relationship between socio-demographic factors and PIH. Pregnant women with Qatari nationality were 30% more likely to have PIH (Adj. OR 0.7; 95% CI 0.5-0.9, p = 0.03). Those living in villas were 50% more likely than those living in apartments (Adj. OR 0.5; 95% CI 0.3-0.9) and 40% more likely than those living in traditional houses (Adj. OR 0.6; 95% CI 0.4-0.8) to have PIH. The odds of PIH linearly increases with each decrease of 5,000 QAR in monthly income from > 20,000 to 10-15,000 (Adj. OR 1.2; 95% CI 0.7-2.1, Adj. OR 1.9; 95% CI 1.1-3.2, respectively) and then it starts decreasing from 10,000 to or = 30 (obese) (Adj. OR 10.0; 95% CI 6.4-15.6). Pregnant women who had no history of previous abortion were 60% less likely than those who had positive history of previous abortion (Adj. OR 1.6; 95% CI 1.1-1.2; p = 0.007) to have PIH. The odds of PIH increases by 50% when women do not receive antenatal care (Adj. OR 1.5; 95% CI 1.1-2.1; p = 0.040). Qatar has a high prevalence of PIH compared to both regional and global rates. Maternal age > 30, increased BMI, previous abortion, lack of antenatal care, and physical activity were found to be significantly associated with increased risk of PIH in Arab women and could be potentially modifiable risk

  10. Inhibition of the JAK2/STAT3/SOSC1 Signaling Pathway Improves Secretion Function of Vascular Endothelial Cells in a Rat Model of Pregnancy-Induced Hypertension

    Directory of Open Access Journals (Sweden)

    Jian-Ying Luo

    2016-11-01

    Full Text Available Background/Aims: The present study aimed to investigate the effects of the JAK2/STAT3/SOSC1 signaling pathway on the secretion function of vascular endothelial cells (VECs in a rat model of pregnancy-induced hypertension (PIH. Methods: A PIH rat model was established. Forty-eight pregnant Sprague-Dawley female rats were selected and assigned into four groups: the normal group (normal non-pregnant rats, the non-PIH group (pregnant rats without PIH, the PIH group (pregnant rats with PIH and the AG490 group (pregnant rats with PIH treated with AG490. Systolic blood pressure (SBP and urinary protein (UP were measured. The expressions of JAK2/STAT3/SOSC1 signaling pathway-related proteins in placenta tissues were detect by Western blotting. Radioimmunoassay was applied to detect serum levels of nitric oxide (NO, super oxide dismutase (SOD, placental growth factor (PGF, thromboxane B2 (TXB2 and endothelin (ET. Enzyme-linked immunosorbent assay (ELISA was used to determine serum levels of interleukin-6 (IL-6, interleukin-10 (IL-10 and tumor necrosis factor-α (TNF-α. Results: Compared with the normal and non-PIH groups, the PIH and AG490 groups had higher SBP and UP levels at 17th and 25th day of pregnancy. The expressions of p/t-JAK2, p/t-STAT3 and SOSC1 in the PIH and AG490 groups were higher than those in the non-PIH group, while the expressions of p/t-JAK2, p/t-STAT3 and SOSC1 in the AG490 group were lower than those in the PIH group. Compared with the non-PIH group, serum levels of ET, TXB2, IL-6 and TNF-α were increased in the PIH and AG490 groups, while serum levels of NO, SOD, 6-keto-PGF1a and IL-10 levels were reduced. Furthermore, the AG490 had lower serum levels of ET, TXB2, IL-6 and TNF-α and higher serum levels of NO, SOD, 6-keto-PGF1a and IL-10 than those in the PIH group. Conclusion: Our study provides evidence that inhibition of the JAK2/STAT3/SOSC1 signaling pathway could improve the secretion function of VECs in PIH rats.

  11. Increased risk of pregnancy-induced hypertension and operative delivery after conception induced by in vitro fertilization/intracytoplasmic sperm injection in women aged 40 years and older.

    Science.gov (United States)

    Toshimitsu, Masatake; Nagamatsu, Takeshi; Nagasaka, Takaaki; Iwasawa-Kawai, Yuki; Komatsu, Atsushi; Yamashita, Takahiro; Osuga, Yutaka; Fujii, Tomoyuki

    2014-10-01

    To clarify the association between preconception fertility status and obstetric outcomes in women aged 40 years and older. Retrospective study by reviewing medical records. Tertiary perinatal center in a university hospital. 330 women aged 40 years and older who delivered a singleton from 2006 to 2010, and 450 women aged 30 to 34 years who delivered at the same facility as controls. None. Incidence of pregnancy-induced hypertension, gestational diabetes mellitus, preterm birth, low birth weight, and mode of delivery assessed based on the mode of conception; spontaneous conception (SC) and in vitro fertilization/intracytoplasmic sperm injection conception (IVF-ICSI). The incidence of pregnancy-induced hypertension was statistically significantly higher in IVF-ICSI group than the SC group. This gap was commonly observed in both the women aged 40 years and older and those in the 30 to 34 age group. No statistically significant difference was observed in the frequency of gestational diabetes mellitus, preterm birth, or low birth weight. As a characteristic of nulliparous women of advanced age, the rate of operative delivery, which includes emergency cesarean section and instrumental delivery, was statistically significantly higher in IVF-ICSI group than in the SC group. Detailed investigation into the medical indications for operative delivery revealed that the difference was attributable to the elevated incidence of labor protraction and arrest. Preconception fertility status can be a predicting factor of the incidence of pregnancy-induced hypertension and labor outcome, especially for women aged 40 years and older. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  12. Potential for an Arctic-breeding migratory bird to adjust spring migration phenology to Arctic amplification

    NARCIS (Netherlands)

    Lameris, T.K.; Scholten, Ilse; Bauer, S.; Cobben, M.M.P.; Ens, B.J.; Nolet, B.A.

    2017-01-01

    Arctic amplification, the accelerated climate warming in the polar regions, is causing a more rapid advancement of the onset of spring in the Arctic than in temperate regions. Consequently, the arrival of many migratory birds in the Arctic is thought to become increasingly mismatched with the onset

  13. Benefits of the Fiber Optic versus the Electret Microphone in Voice Amplification

    Science.gov (United States)

    Kyriakou, Kyriaki; Fisher, Helene R.

    2013-01-01

    Background: Voice disorders that result in reduced loudness may cause difficulty in communicating, socializing and participating in occupational activities. Amplification is often recommended in order to facilitate functional communication, reduce vocal load and avoid developing maladaptive compensatory behaviours. The most common microphone used…

  14. A Label-Free and Sensitive Fluorescent Qualitative Assay for Bisphenol A Based on Rolling Circle Amplification/Exonuclease III-Combined Cascade Amplification.

    Science.gov (United States)

    Li, Xia; Song, Juan; Xue, Qing-Wang; You, Fu-Heng; Lu, Xia; Kong, Yan-Cong; Ma, Shu-Yi; Jiang, Wei; Li, Chen-Zhong

    2016-10-21

    Bisphenol A (BPA) detection in drinking water and food packaging materials has attracted much attention since the discovery that BPA can interfere with normal physiological processes and cause adverse health effects. Here, we constructed a label-free aptamer fluorescent assay for selective and sensitive detection of BPA based on the rolling circle amplification (RCA)/Exonuclease III (Exo III)-combined cascade amplification strategy. First, the duplex DNA probe (RP) with anti-BPA aptamer and trigger sequence was designed for BPA recognition and signal amplification. Next, under the action of BPA, the trigger probe was liberated from RP to initiate RCA reaction as primary amplification. Subsequently, the RCA products were used to trigger Exo III assisted secondary amplification with the help of hairpin probes, producing plenty of "G-quadruplex" in lantern-like structures. Finally, the continuously enriched "G-quadruplex lanterns" were lightened by zinc(II)-protoporphyrin IX (ZnPPIX) generating enhanced fluorescence signals. By integrating the primary RCA and secondary Exo III mediated cascade amplification strategy, this method displayed an excellent sensitivity with the detection limits of 5.4 × 10 -17 M. In addition, the anti-BPA aptamer exhibits high recognition ability with BPA, guaranteeing the specificity of detection. The reporter signal probe (G-quadruplex with ZnPPIX) provides a label-free fluorescence signals readout without complicated labeling procedures, making the method simple in design and cost-effective in operation. Moreover, environmental samples analysis was also performed, suggesting that our strategy was reliable and had a great potential application in environmental monitoring.

  15. A Label-Free and Sensitive Fluorescent Qualitative Assay for Bisphenol A Based on Rolling Circle Amplification/Exonuclease III-Combined Cascade Amplification

    Directory of Open Access Journals (Sweden)

    Xia Li

    2016-10-01

    Full Text Available Bisphenol A (BPA detection in drinking water and food packaging materials has attracted much attention since the discovery that BPA can interfere with normal physiological processes and cause adverse health effects. Here, we constructed a label-free aptamer fluorescent assay for selective and sensitive detection of BPA based on the rolling circle amplification (RCA/Exonuclease III (Exo III-combined cascade amplification strategy. First, the duplex DNA probe (RP with anti-BPA aptamer and trigger sequence was designed for BPA recognition and signal amplification. Next, under the action of BPA, the trigger probe was liberated from RP to initiate RCA reaction as primary amplification. Subsequently, the RCA products were used to trigger Exo III assisted secondary amplification with the help of hairpin probes, producing plenty of “G-quadruplex” in lantern-like structures. Finally, the continuously enriched “G-quadruplex lanterns” were lightened by zinc(II-protoporphyrin IX (ZnPPIX generating enhanced fluorescence signals. By integrating the primary RCA and secondary Exo III mediated cascade amplification strategy, this method displayed an excellent sensitivity with the detection limits of 5.4 × 10−17 M. In addition, the anti-BPA aptamer exhibits high recognition ability with BPA, guaranteeing the specificity of detection. The reporter signal probe (G-quadruplex with ZnPPIX provides a label-free fluorescence signals readout without complicated labeling procedures, making the method simple in design and cost-effective in operation. Moreover, environmental samples analysis was also performed, suggesting that our strategy was reliable and had a great potential application in environmental monitoring.

  16. An unanticipated cardiac arrest and unusual post-resuscitation psycho-behavioural phenomena/near death experience in a patient with pregnancy induced hypertension and twin pregnancy undergoing elective lower segment caesarean section

    Directory of Open Access Journals (Sweden)

    Mridul M Panditrao

    2010-01-01

    Full Text Available A case report of a primigravida, who was admitted with severe pregnancy induced hypertension (BP 160/122 mmHg and twin pregnancy, is presented here. Antihypertensive therapy was initiated. Elective LSCS under general anaesthesia was planned. After the birth of both the babies, intramyometrial injections of Carboprost and Pitocin were administered. Immediately, she suffered cardiac arrest. Cardio pulmonary resucitation (CPR was started and within 3 minutes, she was successfully resuscitated. The patient initially showed peculiar psychological changes and with passage of time, certain psycho-behavioural patterns emerged which could be attributed to near death experiences, as described in this case report.

  17. Amplification in Technical Manuals: Theory and Practice.

    Science.gov (United States)

    Killingsworth, M. Jimmie; And Others

    1989-01-01

    Examines how amplification (rhetorical techniques by which discourse is extended to enhance its appeal and information value) tends to increase and improve the coverage, rationale, warnings, behavioral alternatives, examples, previews, and general emphasis of technical manuals. Shows how classical and modern rhetorical theories can be applied to…

  18. Intelligence amplification framework for enhancing scheduling processes

    NARCIS (Netherlands)

    Dobrkovic, Andrej; Liu, Luyao; Iacob, Maria Eugenia; van Hillegersberg, Jos

    2016-01-01

    The scheduling process in a typical business environment consists of predominantly repetitive tasks that have to be completed in limited time and often containing some form of uncertainty. The intelligence amplification is a symbiotic relationship between a human and an intelligent agent. This

  19. Social amplification of risk: a conceptual framework

    International Nuclear Information System (INIS)

    Kasperson, R.E.; Renn, O.; Slovic, P.; Brown, H.S.; Emel, J.; Goble, R.; Kasperson, J.X.; Ratick, S.

    1988-01-01

    One of the most perplexing problems in risk analysis is why some relatively minor risks or risk events, as assessed by technical experts, often elicit strong public concerns and result in substantial impacts upon society and economy. This article sets forth a conceptual framework that seeks to link systematically the technical assessment of risk with psychological, sociological, and cultural perspectives of risk perception and risk-related behavior. The main thesis is that hazards interact with psychological, social, institutional, and cultural processes in ways that may amplify or attenuate public responses to the risk or risk event. A structural description of the social amplification of risk is now possible. Amplification occurs at two stages: in the transfer of information about the risk, and in the response mechanisms of society. Signals about risk are processed by individual and social amplification stations, including the scientist who communicates the risk assessment, the news media, cultural groups, interpersonal networks, and others. Key steps of amplifications can be identified at each stage. The amplified risk leads to behavioral responses, which, in turn, result in secondary impacts. Models are presented that portray the elements and linkages in the proposed conceptual framework

  20. Effect of polariton propagation on spectra of SRS amplification and CARS from polaritons

    International Nuclear Information System (INIS)

    Orlov, Sergei N; Polivanov, Yurii N

    2001-01-01

    The properties of k spectra of SRS amplification and CARS from polaritons caused by 'running out' of polaritons from the volume of their interaction with incident light beams are theoretically analysed. It is shown that the shape and width of the spectra depend on the relation between the size of the overlap region of exciting waves in a crystal along the direction of polariton propagation and the mean free path of polaritons. The conditions are found under which the widths of SRS amplification and CARS spectra give information on the polariton decay. (nonlinear optical phenomena and devices)

  1. Biomass changes and trophic amplification of plankton in a warmer ocean

    KAUST Repository

    Chust, Guillem

    2014-05-07

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  2. Biomass changes and trophic amplification of plankton in a warmer ocean

    KAUST Repository

    Chust, Guillem; Allen, Julian Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason T.; Tsiaras, Kostas P.; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle C.; Daewel, Ute; Wakelin, Sarah L.; Machú , Eric; Pushpadas, Dhanya; Butenschö n, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris J M; Garç on, Vé ronique C.; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A.; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

    2014-01-01

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  3. Biomass changes and trophic amplification of plankton in a warmer ocean.

    Science.gov (United States)

    Chust, Guillem; Allen, J Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason; Tsiaras, Kostas; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle; Daewel, Ute; Wakelin, Sarah L; Machu, Eric; Pushpadas, Dhanya; Butenschon, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris; Garçon, Veronique; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

    2014-07-01

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  4. Relative Role of Horizontal and Vertical Processes in Arctic Amplification

    Science.gov (United States)

    Kim, K. Y.

    2017-12-01

    The physical mechanism of Arctic amplification is still controversial. Specifically, relative role of vertical processes resulting from the reduction of sea ice in the Barents-Kara Seas is not clearly understood in comparison with the horizontal advection of heat and moisture. Using daily data, heat and moisture budgets are analyzed during winter (Dec. 1-Feb. 28) over the region of sea ice reduction in order to delineate the relative roles of horizontal and vertical processes. Detailed heat and moisture budgets in the atmospheric column indicate that the vertical processes, release of turbulent heat fluxes and evaporation, are a major contributor to the increased temperature and specific humidity over the Barents-Kara Seas. In addition, greenhouse effect caused by the increased specific humidity, also plays an important role in Arctic amplification. Horizontal processes such as advection of heat and moisture are the primary source of variability (fluctuations) in temperature and specific humidity in the atmospheric column. Advection of heat and moisture, on the other hand, is little responsible for the net increase in temperature and specific humidity over the Barents-Kara Seas.

  5. Comparison of the Soil Dynamic Amplification Factor and Soil Amplification by Using Microtremor and MASW Methods Respectively

    Science.gov (United States)

    Tuncel, Aykut; Cevdet Özdag, Özkan; Pamuk, Eren; Akgün, Mustafa

    2017-12-01

    Single Station Microtremor method, which is widely used nowadays, is an effective and easy applicable method. In this study, dynamic amplification factor distributions of the study area were obtained using scenario earthquake parameters with single station microtremor data gathered at 112 points. In addition, a surface wave active method, which is known as MASW (Multichannel Analysis of Surface Waves), was applied at 43 profiles to calculate the soil amplification values. Dynamic amplification factor (DAF), soil amplification, the predominant soil period (PSP), geology and topography data of the study area were analysed together. Dynamic amplification factor and soil amplification values were obtained 2 or higher at about sea level parts of the study area which are generally composed of alluvial units. Additionally, in high altitude regions that are composed of volcanic rocks, relatively lower dynamic amplification factor and soil amplification values were obtained. The minimum amplification value in the study area was 1.15, while the maximum amplification value was 3.05 according to the dynamic amplification results and the soil amplification values were between 1.16 and 3.85 in harmony. It is seen that the obtained DAF values and the soil amplification values calculated from the seismic velocities are very similar to each other numerically and regionally. Because of this, it is concluded that the values of the soil amplification obtained by the MASW method and the calculated DAF values in this study are in harmony with each other. Although the depths of research in these two calculation methods are different from each other, the similarity of the results allows us to arrive at the result of how effective the ground layer is on the amplification. It has a great importance to calculate the amplification values and other dynamic parameters by in situ measurements for a planned plot because geological units can vary even at very short distances in heterogeneously

  6. RNA amplification for successful gene profiling analysis

    Directory of Open Access Journals (Sweden)

    Wang Ena

    2005-07-01

    Full Text Available Abstract The study of clinical samples is often limited by the amount of material available to study. While proteins cannot be multiplied in their natural form, DNA and RNA can be amplified from small specimens and used for high-throughput analyses. Therefore, genetic studies offer the best opportunity to screen for novel insights of human pathology when little material is available. Precise estimates of DNA copy numbers in a given specimen are necessary. However, most studies investigate static variables such as the genetic background of patients or mutations within pathological specimens without a need to assess proportionality of expression among different genes throughout the genome. Comparative genomic hybridization of DNA samples represents a crude exception to this rule since genomic amplification or deletion is compared among different specimens directly. For gene expression analysis, however, it is critical to accurately estimate the proportional expression of distinct RNA transcripts since such proportions directly govern cell function by modulating protein expression. Furthermore, comparative estimates of relative RNA expression at different time points portray the response of cells to environmental stimuli, indirectly informing about broader biological events affecting a particular tissue in physiological or pathological conditions. This cognitive reaction of cells is similar to the detection of electroencephalographic patterns which inform about the status of the brain in response to external stimuli. As our need to understand human pathophysiology at the global level increases, the development and refinement of technologies for high fidelity messenger RNA amplification have become the focus of increasing interest during the past decade. The need to increase the abundance of RNA has been met not only for gene specific amplification, but, most importantly for global transcriptome wide, unbiased amplification. Now gene

  7. Clinical significance of determination of changes of plasma Hcy and serum folic acid and vitamin B{sub 12} levels in patients with pregnancy induced hypertension complicated with nephr opathy

    Energy Technology Data Exchange (ETDEWEB)

    Dongxia, Zhou; Xiaoli, Pan; Fangwen, Xie; Jifeng, Fan [Shuyang County People' s Hospital, Jiangsu, Shuyang (China)

    2007-10-15

    Objective: To investigate the clinical significance of changes of plasma homocysteine (Hcy), serum folic acid and vitamin B{sub 12} levels in patients with pregnancy induced hypertension (PIH) complicated with nephropathy. Methods: Plasma Hcy levels was measured with immuno chemistry and serum folic acid and vitamin B{sub 12} levels were detected with RIA in 32 pregnant women with PIH complicated with nephrophy and 70 pregnant women with PIH but without nephrophy and 35 pregnant women without PIH (as controls). Results; The plasma Hcy levels in patients with PIH were significantly higher than those without (i.e. controls) (P<0.01), while the serum folic acid, vitaminB{sub 12} levels decreased markedly (P<0.01). Among the pregnant women with PIH, plasma Hcy levels were significantly higher and serum folic acid, B{sub 12} levels were significantly lower in the patients complicated with nepropathy than those in patients without nephropathy (P<0.01). conclusion: Determination of plasma Hcy and serum folic acid and vitaminB{sub 12} levels is clinically useful in the management in patients with pregnancy induced hypertension complicated with nephropthy. (authors)

  8. Digital Microfluidics for Nucleic Acid Amplification

    Directory of Open Access Journals (Sweden)

    Beatriz Coelho

    2017-06-01

    Full Text Available Digital Microfluidics (DMF has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings.

  9. Light amplification by seeded Kerr instability

    Science.gov (United States)

    Vampa, G.; Hammond, T. J.; Nesrallah, M.; Naumov, A. Yu.; Corkum, P. B.; Brabec, T.

    2018-02-01

    Amplification of femtosecond laser pulses typically requires a lasing medium or a nonlinear crystal. In either case, the chemical properties of the lasing medium or the momentum conservation in the nonlinear crystal constrain the frequency and the bandwidth of the amplified pulses. We demonstrate high gain amplification (greater than 1000) of widely tunable (0.5 to 2.2 micrometers) and short (less than 60 femtosecond) laser pulses, up to intensities of 1 terawatt per square centimeter, by seeding the modulation instability in an Y3Al5O12 crystal pumped by femtosecond near-infrared pulses. Our method avoids constraints related to doping and phase matching and therefore can occur in a wider pool of glasses and crystals even at far-infrared frequencies and for single-cycle pulses. Such amplified pulses are ideal to study strong-field processes in solids and highly excited states in gases.

  10. Parametric nanomechanical amplification at very high frequency.

    Science.gov (United States)

    Karabalin, R B; Feng, X L; Roukes, M L

    2009-09-01

    Parametric resonance and amplification are important in both fundamental physics and technological applications. Here we report very high frequency (VHF) parametric resonators and mechanical-domain amplifiers based on nanoelectromechanical systems (NEMS). Compound mechanical nanostructures patterned by multilayer, top-down nanofabrication are read out by a novel scheme that parametrically modulates longitudinal stress in doubly clamped beam NEMS resonators. Parametric pumping and signal amplification are demonstrated for VHF resonators up to approximately 130 MHz and provide useful enhancement of both resonance signal amplitude and quality factor. We find that Joule heating and reduced thermal conductance in these nanostructures ultimately impose an upper limit to device performance. We develop a theoretical model to account for both the parametric response and nonequilibrium thermal transport in these composite nanostructures. The results closely conform to our experimental observations, elucidate the frequency and threshold-voltage scaling in parametric VHF NEMS resonators and sensors, and establish the ultimate sensitivity limits of this approach.

  11. Hormonal Involvement in Breast Cancer Gene Amplification

    Science.gov (United States)

    2010-10-01

    been shown to induce DN A amplification in yeast (Gopalakrishnan et al., 2001; Nguy en et al., 2001; Green et al., 2006) an d increased Cdt1 results in...re-replication in human cells (Dorn et al., 2008). The N- terminus of Cdt1 is important for re-replication, perhaps through interactions with PCNA...evolution of a cancer genome. Genome Res. (Epub. Dec. 3, 2008). Harris TD, Buzby PR, Babcock H, Beer E, Bowers J, Bras lavsky I, Causey M

  12. Fast amplification system for gamma spectroscopy

    International Nuclear Information System (INIS)

    Jesus, E.F.O.; Lopes, R.T.

    1992-01-01

    An amplification system for gamma spectroscopy with high counting rates was developed. The system was constructed with operational amplifiers, and tested and compared with ORTEC conventional system, using Iridium-192 as source of 9,25 x 10 1 0 Bq of activity and NaI (Tl) detector. The constructed system showed a better performance in relation to efficiency and resolution parameters, tested before. (C.G.C.)

  13. Optimized thermal amplification in a radiative transistor

    Energy Technology Data Exchange (ETDEWEB)

    Prod' homme, Hugo; Ordonez-Miranda, Jose; Ezzahri, Younes, E-mail: younes.ezzahri@univ-poitiers.fr; Drevillon, Jeremie; Joulain, Karl [Institut Pprime, CNRS, Université de Poitiers, ISAE-ENSMA, F-86962 Futuroscope Chasseneuil (France)

    2016-05-21

    The thermal performance of a far-field radiative transistor made up of a VO{sub 2} base in between a blackbody collector and a blackbody emitter is theoretically studied and optimized. This is done by using the grey approximation on the emissivity of VO{sub 2} and deriving analytical expressions for the involved heat fluxes and transistor amplification factor. It is shown that this amplification factor can be maximized by tuning the base temperature close to its critical one, which is determined by the temperature derivative of the VO{sub 2} emissivity and the equilibrium temperatures of the collector and emitter. This maximization is the result of the presence of two bi-stable temperatures appearing during the heating and cooling processes of the VO{sub 2} base and enables a thermal switching (temperature jump) characterized by a sizeable variation of the collector-to-base and base-to-emitter heat fluxes associated with a slight change of the applied power to the base. This switching effect leads to the optimization of the amplification factor and therefore it could be used for thermal modulation purposes.

  14. HER-2 amplification in tubular carcinoma of the breast.

    Science.gov (United States)

    Oakley, Gerard J; Tubbs, Raymond R; Crowe, Joseph; Sebek, Bruce; Budd, G Thomas; Patrick, Rebecca J; Procop, Gary W

    2006-07-01

    The prognostic and therapeutic implications of HER-2 gene amplification and estrogen and progesterone receptor status in breast cancer are well described. To address the relative paucity of information concerning HER-2 amplification for tubular carcinomas, we assessed the frequency of gene amplification in 55 tubular carcinomas of the breast from 54 patients, 5 of which had axillary node metastases. The HER-2 gene copy number was assessed by fluorescence in situ hybridization for the majority of tumors analyzed, whereas estrogen and progesterone receptor status was achieved by immunohistochemical analysis. HER-2 gene amplification was not observed in any of the tumors examined, and most were estrogen receptor-positive. This HER-2 gene amplification frequency was significantly lower than the frequency of gene amplification previously reported for all invasive ductal carcinoma of no special type (P < .01). HER-2 gene amplification likely occurs infrequently, or not at all, in tubular carcinomas of the breast, whereas most express estrogen receptors.

  15. A large ungated TPC with GEM amplification

    Science.gov (United States)

    Berger, M.; Ball, M.; Fabbietti, L.; Ketzer, B.; Arora, R.; Beck, R.; Böhmer, F. V.; Chen, J.-C.; Cusanno, F.; Dørheim, S.; García, F.; Hehner, J.; Herrmann, N.; Höppner, C.; Kaiser, D.; Kis̆, M.; Kleipa, V.; Konorov, I.; Kunkel, J.; Kurz, N.; Leifels, Y.; Müllner, P.; Münzer, R.; Neubert, S.; Rauch, J.; Schmidt, C. J.; Schmitz, R.; Soyk, D.; Vandenbroucke, M.; Voss, B.; Walther, D.; Zmeskal, J.

    2017-10-01

    A Time Projection Chamber (TPC) is an ideal device for the detection of charged particle tracks in a large volume covering a solid angle of almost 4 π. The high density of hits on a given particle track facilitates the task of pattern recognition in a high-occupancy environment and in addition provides particle identification by measuring the specific energy loss for each track. For these reasons, TPCs with Multiwire Proportional Chamber (MWPC) amplification have been and are widely used in experiments recording heavy-ion collisions. A significant drawback, however, is the large dead time of the order of 1 ms per event generated by the use of a gating grid, which is mandatory to prevent ions created in the amplification region from drifting back into the drift volume, where they would severely distort the drift path of subsequent tracks. For experiments with higher event rates this concept of a conventional TPC operating with a triggered gating grid can therefore not be applied without a significant loss of data. A continuous readout of the signals is the more appropriate way of operation. This, however, constitutes a change of paradigm with considerable challenges to be met concerning the amplification region, the design and bandwidth of the readout electronics, and the data handling. A mandatory prerequisite for such an operation is a sufficiently good suppression of the ion backflow from the avalanche region, which otherwise limits the tracking and particle identification capabilities of such a detector. Gas Electron Multipliers (GEM) are a promising candidate to combine excellent spatial resolution with an intrinsic suppression of ions. In this paper we describe the design, construction and the commissioning of a large TPC with GEM amplification and without gating grid (GEM-TPC). The design requirements have driven innovations in the construction of a light-weight field-cage, a supporting media flange, the GEM amplification and the readout system, which are

  16. Quantitative analysis of night skyglow amplification under cloudy conditions

    Science.gov (United States)

    Kocifaj, Miroslav; Solano Lamphar, Héctor Antonio

    2014-10-01

    The radiance produced by artificial light is a major source of nighttime over-illumination. It can, however, be treated experimentally using ground-based and satellite data. These two types of data complement each other and together have a high information content. For instance, the satellite data enable upward light emissions to be normalized, and this in turn allows skyglow levels at the ground to be modelled under cloudy or overcast conditions. Excessive night lighting imposes an unacceptable burden on nature, humans and professional astronomy. For this reason, there is a pressing need to determine the total amount of downwelling diffuse radiation. Undoubtedly, cloudy periods can cause a significant increase in skyglow as a result of amplification owing to diffuse reflection from clouds. While it is recognized that the amplification factor (AF) varies with cloud cover, the effects of different types of clouds, of atmospheric turbidity and of the geometrical relationships between the positions of an individual observer, the cloud layer, and the light source are in general poorly known. In this paper the AF is quantitatively analysed considering different aerosol optical depths (AODs), urban layout sizes and cloud types with specific albedos and altitudes. The computational results show that the AF peaks near the edges of a city rather than at its centre. In addition, the AF appears to be a decreasing function of AOD, which is particularly important when modelling the skyglow in regions with apparent temporal or seasonal variability of atmospheric turbidity. The findings in this paper will be useful to those designing engineering applications or modelling light pollution, as well as to astronomers and environmental scientists who aim to predict the amplification of skyglow caused by clouds. In addition, the semi-analytical formulae can be used to estimate the AF levels, especially in densely populated metropolitan regions for which detailed computations may be CPU

  17. Loop mediated isothermal amplification: An innovative gene amplification technique for animal diseases

    Directory of Open Access Journals (Sweden)

    Pravas Ranjan Sahoo

    2016-05-01

    Full Text Available India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease.

  18. Loop mediated isothermal amplification: An innovative gene amplification technique for animal diseases.

    Science.gov (United States)

    Sahoo, Pravas Ranjan; Sethy, Kamadev; Mohapatra, Swagat; Panda, Debasis

    2016-05-01

    India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease.

  19. Social amplification of risk: An empirical study

    International Nuclear Information System (INIS)

    Burns, W.; Slovic, P.; Kasperson, R.; Kasperson, J.; Renn, O.; Emani, S.

    1990-09-01

    The social amplification of risk is a theoretical framework that addresses an important deficiency of formal risk assessment methods and procedures. Typically assessments of risk from technological mishaps have been based upon the expected number of people who could be killed or injured or the amount of property that might be damaged. The diverse and consequential impacts that followed in the aftermath of the Three Mile Island accident make it clear that risk assessments that exclude the role of public perceptions of risk will greatly underestimate the potential costs of certain types of hazards. The accident at Three Mile Island produced no direct fatalities and few, if any, expected deaths due to cancer, yet few other accidents in history have had such costly societal impacts. The experience of amplified impacts argues for the development of a broadened theoretical and methodological perspective capable of integrating technical assessment of risk with public perceptions. This report presents the results to date in an ongoing research effort to better understand the complex processes by which adverse events produce impacts. In particular this research attempts to construct a framework that can account for those events that have produced, or are capable of producing, greater societal impacts than would be forecast by traditional risk assessment methods. This study demonstrates that the social amplification of risk involves interactions between sophisticated technological hazards, public and private institutions, and subtle individual and public perceptions and behaviors. These factors, and the variables underlying the intricate processes of social amplification that occur in modern society, are not fully defined and clarified in this report. 19 refs., 9 figs., 10 tabs

  20. Gas amplification properties of GEM foils

    International Nuclear Information System (INIS)

    Beck, Jeannine

    2009-01-01

    In the framework of the detector concept International Linear Detector for the future accelerator project International Linear Collider, in which electrons and positrons at c. m. energies of 500 GeV are brought to collision, a time projection chamber shall be applied as central track detector. By the application of such a chamber as track detector a three-dimensional reconstruction of the track points is possible. If a particle passes the gas volume within the chamber it ionizises single gas atoms and the arising electrons move after the amplification in the GEM arrangement to the anode, so that a two-dimensional projection of the particle track is possible. The third dimension is calculated from the drift time of the electrons. The advances of this readout system consist therein that a better position resolution than by a multiwire proportional chamber is reached and the back-drifting ions can be strongly suppressed. Aim of this thesis are studies for a GEM module, which shall be used in a large TPC prototype. Concerning different requirements it is valid to compare different GEMs in order to can meet an optimal choice. In a small prototype present at DESY measurements for the acquisition of GEM-describing parameters were performed. The taking into operation of the test TPC was part of this thesis. Tracks were generated by a radioactive source, by means of which the gas amplification was determined. With the measurement arrangement gas-amplifier foils of different kind were compared in view of their amplification properties and their energy resolution power and systematically studied. Five different GEM performances were studied in the test TPC. These foils differ in their geometrical classification parameters, the fabrication process, or the materials. The GEMs produced at CERN possess in comparison with GEMs of the Japanese firm SciEnergy and a GEM of the US-American firm Tech-Etch the best amplification and resolution properties. Furthermore a new GEM framing

  1. Amplification Effects and Unconventional Monetary Policies

    Directory of Open Access Journals (Sweden)

    Cécile BASTIDON GILLES

    2012-02-01

    Full Text Available Global financial crises trigger off amplification effects, which allow relatively small shocks to propagate through the whole financial system. For this reason, the range of Central banks policies is now widening beyond conventional monetary policies and lending of last resort. The aim of this paper is to establish a rule for this practice. The model is based on the formalization of funding conditions in various types of markets. We conduct a comprehensive analysis of the “unconventional monetary policies”, and especially quantify government bonds purchases by the Central bank.

  2. Amplification of curvature perturbations in cyclic cosmology

    International Nuclear Information System (INIS)

    Zhang Jun; Liu Zhiguo; Piao Yunsong

    2010-01-01

    We analytically and numerically show that through the cycles with nonsingular bounce, the amplitude of curvature perturbation on a large scale will be amplified and the power spectrum will redden. In some sense, this amplification will eventually destroy the homogeneity of the background, which will lead to the ultimate end of cycles of the global universe. We argue that for the model with increasing cycles, it might be possible that a fissiparous multiverse will emerge after one or several cycles, in which the cycles will continue only at corresponding local regions.

  3. Parametric Amplification of Gravitational Fluctuations during Reheating

    International Nuclear Information System (INIS)

    Finelli, F.; Brandenberger, R.; Finelli, F.

    1999-01-01

    Cosmological perturbations can undergo amplification by parametric resonance during preheating even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial to determine the strength of the instability. To extract specific signatures of the oscillating inflaton field during reheating, it is essential to focus on a variable describing metric fluctuations which is constant in the standard analyses of inflation. For a massive inflaton without self-coupling, we find no additional growth of superhorizon modes during reheating beyond the usual predictions. For a massless self-coupled inflaton, there is a sub-Hubble scale resonance. copyright 1999 The American Physical Society

  4. An aptasensor for staphylococcus aureus based on nicking enzyme amplification reaction and rolling circle amplification.

    Science.gov (United States)

    Xu, Jingguo; Guo, Jia; Maina, Sarah Wanjiku; Yang, Yumeng; Hu, Yimin; Li, Xuanxuan; Qiu, Jiarong; Xin, Zhihong

    2018-05-15

    An ultra-sensitive aptamer-based biosensor for the detection of staphylococcus aureus was established by adopting the nicking enzyme amplification reaction (NEAR) and the rolling circle amplification (RCA) technologies. Aptamer-probe (AP), containing an aptamer and a probe sequence, was developed to act as the recognition unit of the biosensor, which was specifically bound to S. aureus. The probe was released from AP and initiated into the subsequent DNA amplification reactions where S. aureus was present, converting the detection of S. aureus to the investigation of probe oligonucleotide. The RCA amplification products contained a G-quadruplex motif and formed a three dimensional structure in presence of hemin. The G4/hemin complex showed horseradish peroxidase (HRP)-mimic activity and catalyzed the chemiluminescence reaction of luminol mediated by H 2 O 2 . The results showed that the established biosensor could detect S. aureus specifically with a good linear correlation at 5-10 4  CFU/mL. The signal values based on NEAR-RCA two-step cycle were boosted acutely, much higher than that relied on one-cycle magnification. The limit of detection (LoD) was determined to be as low as 5 CFU/mL. The established aptasensor exhibited a good discrimination of living against dead S. aureus, and can be applied to detect S. aureus in the food industry. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification.

    Science.gov (United States)

    Ziesemer, Kirsten A; Mann, Allison E; Sankaranarayanan, Krithivasan; Schroeder, Hannes; Ozga, Andrew T; Brandt, Bernd W; Zaura, Egija; Waters-Rist, Andrea; Hoogland, Menno; Salazar-García, Domingo C; Aldenderfer, Mark; Speller, Camilla; Hendy, Jessica; Weston, Darlene A; MacDonald, Sandy J; Thomas, Gavin H; Collins, Matthew J; Lewis, Cecil M; Hofman, Corinne; Warinner, Christina

    2015-11-13

    To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341-534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon sequencing. Through comparisons of microbial taxonomic counts from paired amplicon (V3 U341F/534R) and shotgun sequencing datasets, we demonstrate that extensive length polymorphisms in the V3 region are a consistent and major cause of differential amplification leading to taxonomic bias in ancient microbiome reconstructions based on amplicon sequencing. We conclude that systematic amplification bias confounds attempts to accurately reconstruct microbiome taxonomic profiles from 16S rRNA V3 amplicon data generated using universal primers. Because in silico analysis indicates that alternative 16S rRNA hypervariable regions will present similar challenges, we advocate for the use of a shotgun metagenomics approach in ancient microbiome reconstructions.

  6. C-MET overexpression and amplification in gliomas.

    Science.gov (United States)

    Kwak, Yoonjin; Kim, Seong-Ik; Park, Chul-Kee; Paek, Sun Ha; Lee, Soon-Tae; Park, Sung-Hye

    2015-01-01

    We investigated c-Met overexpression and MET gene amplification in gliomas to determine their incidence and prognostic significance. c-Met immunohistochemistry and MET gene fluorescence in situ hybridization were carried out on tissue microarrays from 250 patients with gliomas (137 grade IV GBMs and 113 grade II and III diffuse gliomas). Clinicopathological features of these cases were reviewed. c-Met overexpression and MET gene amplification were detected in 13.1% and 5.1% of the GBMs, respectively. All the MET-amplified cases showed c-Met overexpression, but MET amplification was not always concordant with c-Met overexpression. None of grade II and III gliomas demonstrated c-Met overexpression or MET gene amplification. Mean survival of the GBM patients with MET amplification was not significantly different from patients without MET amplification (P=0.155). However, GBM patients with c-Met overexpression survived longer than patients without c-Met overexpression (P=0.035). Although MET amplification was not related to poor GBM prognosis, it is partially associated with the aggressiveness of gliomas, as MET amplification was found only in grade IV, not in grade II and III gliomas. We suggest that MET inhibitor therapy may be beneficial in about 5% GBMs, which was the incidence of MET gene amplification found in the patients included in this study.

  7. Earthquake acceleration amplification based on single microtremor test

    Science.gov (United States)

    Jaya Syahbana, Arifan; Kurniawan, Rahmat; Soebowo, Eko

    2018-02-01

    Understanding soil dynamics is needed to understand soil behaviour, including the parameters of earthquake acceleration amplification. Many researchers now conduct single microtremor tests to obtain amplification of velocity and natural periods of soil at test sites. However, these amplification parameters are rarely used, so a method is needed to convert the velocity amplification to acceleration amplification. This paper will discuss the proposed process of changing the value of amplification. The proposed method is to integrate the time histories of the synthetic earthquake acceleration of the soil surface under the deaggregation at that location so the time histories of the velocity earthquake will be obtained. Next is to conduct a “fitting curve” between amplification by a single microtremor test with amplification of the synthetic earthquake velocity time histories. After obtaining the fitting curve time histories of velocity, differentiation will be conducted to obtain fitting curve acceleration time histories. The final step after obtaining the fitting curve is to compare the acceleration of the “fitting curve” against the histories time of the acceleration of synthetic earthquake at bedrocks to obtain single microtremor acceleration amplification factor.

  8. Quantum tomography enhanced through parametric amplification

    Science.gov (United States)

    Knyazev, E.; Spasibko, K. Yu; Chekhova, M. V.; Khalili, F. Ya

    2018-01-01

    Quantum tomography is the standard method of reconstructing the Wigner function of quantum states of light by means of balanced homodyne detection. The reconstruction quality strongly depends on the photodetectors quantum efficiency and other losses in the measurement setup. In this article we analyze in detail a protocol of enhanced quantum tomography, proposed by Leonhardt and Paul [1] which allows one to reduce the degrading effect of detection losses. It is based on phase-sensitive parametric amplification, with the phase of the amplified quadrature being scanned synchronously with the local oscillator phase. Although with sufficiently strong amplification the protocol enables overcoming any detection inefficiency, it was so far not implemented in the experiment, probably due to the losses in the amplifier. Here we discuss a possible proof-of-principle experiment with a traveling-wave parametric amplifier. We show that with the state-of-the-art optical elements, the protocol enables high fidelity tomographic reconstruction of bright non-classical states of light. We consider two examples: bright squeezed vacuum and squeezed single-photon state, with the latter being a non-Gaussian state and both strongly affected by the losses.

  9. Electronic cyclotron radiation amplification in thermonuclear plasmas

    International Nuclear Information System (INIS)

    Ziebell, L.F.

    1983-01-01

    The amplified emission of electron cyclotron radiation near the fundamental frequency from an inhomogeneous, anisotropic plasma slab is investigated in a linear theory. Plasma polarization effects are consistently included. Expressions are developed in the WKB approximation for emission in the ordinary and the extraordinary modes, for propagation perpendicular to the magnetic field. Numerical results are given for the extraordinary mode, for which effects are strongest. For the case of a loss-cone-type electron momentum distribution, it is shown that the amplification is sensitively dependent on the ratio of parallel-to-perpendicular temperature and on inhomogeneities in the magnetic field. The dependence of the amplification on the distribution is further investigated by considering superpositions of loss-cone and Maxwellian components. It is show that the presence of a Maxwellian component in general reduces the emission relative to the pure loss-cone case, and situations occur in which a layer in the slab very effectively absorbs all the radiation amplified elsewhere. A peculiar behaviour of the refractive index, which occurs in the transition from the pure loss-cone to the pure Maxwellian case, is discussed. (author)

  10. Determinación del índice de resistencia a la insulina mediante homa y su relación con el riesgo de hipertensión inducida por el embarazo Insulin resistance index assessment by homa and its relation with the risk of pregnancy induced hypertension

    Directory of Open Access Journals (Sweden)

    Jesús Sierra-Laguado

    Full Text Available Objetivo: investigar si el grado de resistencia a la insulina determinado por el índice HOMA, predice de manera temprana el desarrollo de hipertensión inducida por el embarazo en gestantes colombianas. Diseño-métodos: se realizó un estudio de casos y controles anidado en una cohorte prospectiva de 438 mujeres primigestantes, normotensas y con edad gestacional menor de 30 semanas. Se determinó el índice HOMA a partir de la medición de glucemia e insulina plasmática en ayunas, por métodos de glucosa oxidasa y quimioluminiscencia, respectivamente. Resultados: veintitrés mujeres desarrollaron hipertensión inducida por el embarazo (5,25%. Se seleccionaron de forma aleatoria dos embarazadas normotensas como controles por cada caso, pareadas por edad materna y gestacional al momento de su inclusión. Las mujeres que posteriormente desarrollaron hipertensión inducida por el embarazo presentaron mayores niveles de HOMA (1,48 ± 0,98 vs. 0,96 ± 0,70, pObjective: to assess whether insulin resistance determined by homeostatic model assessment (HOMA is an early predictor of the development of pregnancy induced hypertension in Colombian pregnant women. Methods: we conducted a nested case control study in a prospective cohort of four hundred and thirty eigth normotensive primigravidae women, with gestational age < 30 weeks. The HOMA was calculated using fasting plasma concentrations of glucose and insulin, determined by glucose-oxidase and chemoluminiscence methods, respectively. Results: twenty-three pregnant women developed pregnancy induced hypertension (5.25%. Two normotensive pregnant women were selected as controls for each case, matched by gestational and maternal age at enrollment. The women who subsequently developed pregnancy induced hypertension had higher levels of HOMA (1.48 ± 0.98 vs 0.96 ± 0.70, p<0.001, which was associated with an increased risk of developing pregnancy induced hypertension (OR: 3.8, IC95%: 1.1-12.8 p=0

  11. The rolling circle amplification and next generation sequencing ...

    African Journals Online (AJOL)

    Rolling circle amplification is a simple approach of enriching populations of single-stranded DNA plant begomovirus genomes (genus, Begomovirus; family, Geminiviridae). This is an innovative approach that utilizes the robustness of the bacteriophage phi29 DNA polymerase used in circle amplification, together with deep ...

  12. Amplification of Chirality in Hydrogen-Bonded Tetrarosette Helices

    NARCIS (Netherlands)

    Mateos timoneda, Miguel; Crego Calama, Mercedes; Reinhoudt, David

    2006-01-01

    The amplification of chirality in hydrogen-bonded tetrarosette assemblies under thermodynamic equilibrium is described. The extent of the chiral amplification obtained by means of “sergeants-and-soldiers” experiments depends only on the structure of the assembly and it is independent of the

  13. Explanatory Model for Sound Amplification in a Stethoscope

    Science.gov (United States)

    Eshach, H.; Volfson, A.

    2015-01-01

    In the present paper we suggest an original physical explanatory model that explains the mechanism of the sound amplification process in a stethoscope. We discuss the amplification of a single pulse, a continuous wave of certain frequency, and finally we address the resonant frequencies. It is our belief that this model may provide students with…

  14. An enzymatic signal amplification system for calorimetric studies of cellobiohydrolases

    DEFF Research Database (Denmark)

    Murphy, Leigh; Baumann, Martin Johannes; Borch, Kim

    2010-01-01

    amplification method has been developed to measure even slow hydrolytically active enzymes such as cellobiohydrolases. This method is explained in detail for the amplification of the heat signal by more than 130 times by using glucose oxidase and catalase. The kinetics of this complex coupled reaction system...

  15. Chirped pulse amplification: Present and future

    International Nuclear Information System (INIS)

    Maine, P.; Strickland, D.; Pessot, M.; Squier, J.; Bado, P.; Mourou, G.; Harter, D.

    1988-01-01

    Short pulses with ultrahigh peak powers have been generated in Nd: glass and Alexandrite using the Chirped Pulse Amplification (CPA) technique. This technique has been successful in producing picosecond terawatt pulses with a table-top laser system. In the near future, CPA will be applied to large laser systems such as NOVA to produce petawatt pulses (1 kJ in a 1 ps pulse) with focused intensities exceeding 10/sup /plus/21/ W/cm 2 . These pulses will be associated with electric fields in excess of 100 e/a/sub o/ 2 and blackbody energy densities equivalent to 3 /times/ 10 10 J/cm 3 . This petawatt source will have important applications in x-ray laser research and will lead to fundamentally new experiments in atomic, nuclear, solid-state, plasma, and high-energy density physics. A review of present and future designs are discussed. 17 refs., 5 figs

  16. Raman amplification in optical communication systems

    DEFF Research Database (Denmark)

    Kjær, Rasmus

    2008-01-01

    Fiber Raman amplifiers are investigated with the purpose of identifying new applications and limitations for their use in optical communication systems. Three main topics are investigated, namely: New applications of dispersion compensating Raman amplifiers, the use Raman amplification to increase...... fiberbaserede Raman-forstærkere med henblik på at identificere både deres begrænsninger og nye anvendelsesmuligheder i optiske kommunikationssystemer. En numerisk forstærkermodel er blevet udviklet for bedre at forstå forstærkerens dynamik, dens gain- og støjbegrænsninger. Modellen bruges til at forudsige...... forstærkerens statiske og dynamiske egenskaber, og det eftervises at dens resultater er i god overensstemmelse med eksperimentelle forstærkermålinger. Dispersions-kompenserende fiber er på grund af sin store udbredelse og fiberens høje Raman gain effektivitet et meget velegnet Raman gain-medium. Tre nye...

  17. Pain Amplification Syndrome: A Biopsychosocial Approach.

    Science.gov (United States)

    Namerow, Lisa B; Kutner, Emily C; Wakefield, Emily C; Rzepski, Barbara R; Sahl, Robert A

    2016-08-01

    Pediatric neurologists frequently encounter patients who present with significant musculoskeletal pain that cannot be attributed to a specific injury or illness, which can often be defined as pain amplification syndrome (PAS). PAS in children and adolescents is the result of a heightened pain sensitivity pathway, which is intensified by significant biological, psychological, and social contributors. Appropriate assessment and multimodal intervention of PAS are crucial to treatment success, including neurology and behavioral health collaborative treatment plans to restore patient function and reduce pain perception. Pediatric neurologists are imperative in the identification of patients with PAS, providing the family assurance in diagnosis and validation of pain, and directing patients to the appropriate multidisciplinary treatment pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Whole genome amplification in preimplantation genetic diagnosis*

    Science.gov (United States)

    Zheng, Ying-ming; Wang, Ning; Li, Lei; Jin, Fan

    2011-01-01

    Preimplantation genetic diagnosis (PGD) refers to a procedure for genetically analyzing embryos prior to implantation, improving the chance of conception for patients at high risk of transmitting specific inherited disorders. This method has been widely used for a large number of genetic disorders since the first successful application in the early 1990s. Polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) are the two main methods in PGD, but there are some inevitable shortcomings limiting the scope of genetic diagnosis. Fortunately, different whole genome amplification (WGA) techniques have been developed to overcome these problems. Sufficient DNA can be amplified and multiple tasks which need abundant DNA can be performed. Moreover, WGA products can be analyzed as a template for multi-loci and multi-gene during the subsequent DNA analysis. In this review, we will focus on the currently available WGA techniques and their applications, as well as the new technical trends from WGA products. PMID:21194180

  19. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    Science.gov (United States)

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same.

  20. Social and political amplification of technological hazards

    International Nuclear Information System (INIS)

    Ibitayo, Olurominiyi O.; Mushkatel, Alvin; Pijawka, K. David

    2004-01-01

    Using an industrial explosion in Henderson, Nevada, as a case study, this paper examines three main issues: the efficacy of a technological hazard event in amplifying otherwise latent issues, the extent to which the hazard event can serve as a focusing event for substantive local and state policy initiatives, and the effect of fragmentation of political authority in managing technological hazards. The findings indicate that the explosion amplified several public safety issues and galvanized the public into pressing for major policy initiatives. However, notwithstanding the amplification of several otherwise latent issues, and the flurry of activities by the state and local governments, the hazard event did not seem to be an effective focusing event or trigger mechanism for substantive state and local policy initiatives. In addition, the study provides evidence of the need for a stronger nexus between political authority, land-use planning and technological hazard management

  1. Resistive wall modes and error field amplification

    International Nuclear Information System (INIS)

    Boozer, Allen H.

    2003-01-01

    Resistive wall modes and the rapid damping of plasma rotation by the amplification of magnetic field errors are related physical phenomena that affect the performance of the advanced tokamak and spherical torus plasma confinement devices. Elements of our understanding of these phenomena and the code that is used to design the major experimental facilities are based on the electrical circuit representation of the response of the plasma to perturbations. Although the circuit representation of the plasma may seem heuristic, this representation can be rigorously obtained using Maxwell's equations and linearity for plasmas that evolve on a disparate time scale from that of external currents. These and related results are derived. In addition methods are given for finding the plasma information that the circuit representation requires using post-processors for codes that calculate perturbed plasma equilibria

  2. Scintillation light detectors with Neganov Luke amplification

    Science.gov (United States)

    Isaila, C.; Boslau, O.; Coppi, C.; Feilitzsch, F. v.; Goldstraß, P.; Jagemann, T.; Jochum, J.; Kemmer, J.; Lachenmaier, T.; Lanfranchi, J.-C.; Pahlke, A.; Potzel, W.; Rau, W.; Stark, M.; Wernicke, D.; Westphal, W.

    2006-04-01

    For an active suppression of the gamma and electron background in the Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) dark matter experiment both phonons and scintillation light generated in a CaWO 4 crystal are detected simultaneously. The phonon signal is read out by a transition edge sensor (TES) on the CaWO 4 crystal. For light detection a silicon absorber equipped with a TES is employed. An efficient background discrimination requires very sensitive light detectors. The threshold can be improved by applying an electric field to the silicon crystal leading to an amplification of the thermal signal due to the Neganov-Luke effect. Measurements showing the improved sensitivity of the light detectors as well as future steps for reducing the observed extra noise will be presented.

  3. Raman Amplification with a Flying Focus

    Science.gov (United States)

    Turnbull, D.; Bucht, S.; Davies, A.; Haberberger, D.; Kessler, T.; Shaw, J. L.; Froula, D. H.

    2018-01-01

    We propose a new laser amplifier scheme utilizing stimulated Raman scattering in plasma in conjunction with a "flying focus"—a chromatic focusing system combined with a chirped pump beam that provides spatiotemporal control over the pump's focal spot. Pump intensity isosurfaces are made to propagate at v =-c so as to be in sync with the injected counterpropagating seed pulse. By setting the pump intensity in the interaction region to be just above the ionization threshold of the background gas, an ionization wave is produced that travels at a fixed distance ahead of the seed. Simulations show that this will make it possible to optimize the plasma temperature and mitigate many of the issues that are known to have impacted previous Raman amplification experiments, in particular, the growth of precursors.

  4. A loop-mediated isothermal amplification assay and sample preparation procedure for sensitive detection of Xanthomonas fragariae in strawberry

    Science.gov (United States)

    Xanthomonas fragariae is a bacterium that causes angular leaf spot of strawberry. Asymptomatic infections are common and contribute to the difficulties in disease management. The aim of this study was to develop a loop-mediated isothermal amplification (LAMP) assay with a bacterial enrichment proced...

  5. Markovian Dynamics of Josephson Parametric Amplification

    Directory of Open Access Journals (Sweden)

    W. Kaiser

    2017-09-01

    Full Text Available In this work, we derive the dynamics of the lossy DC pumped non-degenerate Josephson parametric amplifier (DCPJPA. The main element in a DCPJPA is the superconducting Josephson junction. The DC bias generates the AC Josephson current varying the nonlinear inductance of the junction. By this way the Josephson junction acts as the pump oscillator as well as the time varying reactance of the parametric amplifier. In quantum-limited amplification, losses and noise have an increased impact on the characteristics of an amplifier. We outline the classical model of the lossy DCPJPA and derive the available noise power spectral densities. A classical treatment is not capable of including properties like spontaneous emission which is mandatory in case of amplification at the quantum limit. Thus, we derive a quantum mechanical model of the lossy DCPJPA. Thermal losses are modeled by the quantum Langevin approach, by coupling the quantized system to a photon heat bath in thermodynamic equilibrium. The mode occupation in the bath follows the Bose-Einstein statistics. Based on the second quantization formalism, we derive the Heisenberg equations of motion of both resonator modes. We assume the dynamics of the system to follow the Markovian approximation, i.e. the system only depends on its actual state and is memory-free. We explicitly compute the time evolution of the contributions to the signal mode energy and give numeric examples based on different damping and coupling constants. Our analytic results show, that this model is capable of including thermal noise into the description of the DC pumped non-degenerate Josephson parametric amplifier.

  6. Markovian Dynamics of Josephson Parametric Amplification

    Science.gov (United States)

    Kaiser, Waldemar; Haider, Michael; Russer, Johannes A.; Russer, Peter; Jirauschek, Christian

    2017-09-01

    In this work, we derive the dynamics of the lossy DC pumped non-degenerate Josephson parametric amplifier (DCPJPA). The main element in a DCPJPA is the superconducting Josephson junction. The DC bias generates the AC Josephson current varying the nonlinear inductance of the junction. By this way the Josephson junction acts as the pump oscillator as well as the time varying reactance of the parametric amplifier. In quantum-limited amplification, losses and noise have an increased impact on the characteristics of an amplifier. We outline the classical model of the lossy DCPJPA and derive the available noise power spectral densities. A classical treatment is not capable of including properties like spontaneous emission which is mandatory in case of amplification at the quantum limit. Thus, we derive a quantum mechanical model of the lossy DCPJPA. Thermal losses are modeled by the quantum Langevin approach, by coupling the quantized system to a photon heat bath in thermodynamic equilibrium. The mode occupation in the bath follows the Bose-Einstein statistics. Based on the second quantization formalism, we derive the Heisenberg equations of motion of both resonator modes. We assume the dynamics of the system to follow the Markovian approximation, i.e. the system only depends on its actual state and is memory-free. We explicitly compute the time evolution of the contributions to the signal mode energy and give numeric examples based on different damping and coupling constants. Our analytic results show, that this model is capable of including thermal noise into the description of the DC pumped non-degenerate Josephson parametric amplifier.

  7. Parametric amplifications in the nonlinear transmission line

    Energy Technology Data Exchange (ETDEWEB)

    Kawata, T; Sakai, J; Inoue, H [Toyama Univ., Takaoka (Japan). Faculty of Engineering

    1980-03-01

    The parametric amplification in a transmission line with nonlinear capacitors is analysed theoretically using the equations of three wave interactions. Since this line has two modes, high frequency and low frequency modes, there may occur some mode coupling phenomena through the resonant interactions. We consider three waves with wave number k sub(j) and frequency ..omega..sub(j) in resonance with each other, that is, ..omega../sub 1/ + ..omega../sub 2/ = ..omega../sub 3/ and k/sub 1/ + k/sub 2/ = k/sub 3/, where 0 <= ..omega../sub 1/ <= ..omega../sub 2/ <= ..omega../sub 3/ and k/sub 3/ >= 0. Such conditions are realized in our network and there exist two states: ''forward state'' (each group velocity is positive) and ''backward state'' (one of the group velocities is negative). The coupled equations of three waves has two constant pumps: high frequency (HF) pump and low frequency (LF) pump. Using linear approximations, we examine the possible types of parametric amplification and obtain the power gains depending on the frequency deviation. For only the case of HF pump we get the gain between signals with seme frequency and also get the gain from the low frequency signal to the high frequency signal (''up-conversion'') for the LF pump. The nonlinear analysis gives the exact relation between input and output signals. For the forward state the gain is absolutely suppressed by the ratio of pumping power to input power, while the gain of backward state has no finite maximum and there may appear an ''oscillating state'' if the pumping power is comparatively small.

  8. Ground amplification determined from borehole accelerograms

    International Nuclear Information System (INIS)

    Archuleta, R.J.; Seale, S.H.

    1991-01-01

    The Garner Valley downhole array (GVDA) consists of one surface accelerometer and four downhole accelerometers at depths of 6 m, 15 m, 22m, and 220 m. The five, three-component vertical array of dual-gain accelerometers are capable of measuring accelerations from 3 x 10 -6 g to 2.0 g over a frequency range from 0.0 Hz (0.025, high-gain) Hz to 100 Hz. The site (33 degree 41.60' N, 116 degree 40.20 degree W) is only seven kilometers off the trace of the San Jacinto fault, the most active strand of the San Andreas fault system in southern California and only about 35 km from the San Andreas fault itself. Analysis of individual spectra and spectral ratios for the various depths shows that the zone of weathered granite has a pronounced effect on the spectral amplitudes for frequencies greater than 40 Hz. The soil layer impedance may amplify the high frequencies more than it attenuates. This result must be checked more thoroughly with special consideration of the spectra of the P-wave coda on the horizontal components. Analysis of the P-wave spectra and the spectral ratios shows an increased amplification in the same frequency range (60-90 Hz) where the S-wave spectral ratios imply a change in the attenuation. Comparison of acceleration spectra from two earthquakes, M L 4.2 and M L 2.5 that have nearly the same hypocenter, shows that the near surface amplification and attenuation is nearly the same for both earthquakes. However, the earthquakes themselves are different if we can assume that the recording at 220 m reflects the source spectra with a slight attenuation. The M L 2.5 earthquake has significantly greater high frequency content if the spectra are normalized at the low frequency, i.e., normalization by seismic moment

  9. Cascade DNA nanomachine and exponential amplification biosensing.

    Science.gov (United States)

    Xu, Jianguo; Wu, Zai-Sheng; Shen, Weiyu; Xu, Huo; Li, Hongling; Jia, Lee

    2015-11-15

    DNA is a versatile scaffold for the assembly of multifunctional nanostructures, and potential applications of various DNA nanodevices have been recently demonstrated for disease diagnosis and treatment. In the current study, a powerful cascade DNA nanomachine was developed that can execute the exponential amplification of p53 tumor suppressor gene. During the operation of the newly-proposed DNA nanomachine, dual-cyclical nucleic acid strand-displacement polymerization (dual-CNDP) was ingeniously introduced, where the target trigger is repeatedly used as the fuel molecule and the nicked fragments are dramatically accumulated. Moreover, each displaced nicked fragment is able to activate the another type of cyclical strand-displacement amplification, increasing exponentially the value of fluorescence intensity. Essentially, one target binding event can induce considerable number of subsequent reactions, and the nanodevice was called cascade DNA nanomachine. It can implement several functions, including recognition element, signaling probe, polymerization primer and template. Using the developed autonomous operation of DNA nanomachine, the p53 gene can be quantified in the wide concentration range from 0.05 to 150 nM with the detection limit of 50 pM. If taking into account the final volume of mixture, the detection limit is calculated as lower as 6.2 pM, achieving an desirable assay ability. More strikingly, the mutant gene can be easily distinguished from the wild-type one. The proof-of-concept demonstrations reported herein is expected to promote the development and application of DNA nanomachine, showing great potential value in basic biology and medical diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Study on high gain broadband optical parametric chirped pulse amplification

    International Nuclear Information System (INIS)

    Zhang, S.K.; Fujita, M.; Yamanaka, C.; Yoshida, H.; Kodama, R.; Fujita, H.; Nakatsuka, M.; Izawa, Y.

    2000-01-01

    Optical parametric chirped pulse amplification has apparent advantages over the current schemes for high energy ultrashort pulse amplification. High gain in a single pass amplification, small B-integral, low heat deposition, high contrast ratio and, especially the extremely broad gain bandwidth with large-size crystals available bring people new hope for over multi-PW level at which the existing Nd:glass systems suffered difficulties. In this paper we present simulation and experimental studies for a high gain optical parametric chirped pulse amplification system which may be used as a preamplifier to replace the current complicated regenerative system or multi-pass Ti:sapphire amplifiers. Investigations on the amplification bandwidth and gain with BBO are performed. Analysis and discussions are also given. (author)

  11. Highly frequent promoter methylation and PIK3CA amplification in non-small cell lung cancer (NSCLC)

    International Nuclear Information System (INIS)

    Ji, Meiju; Guan, Haixia; Gao, Cuixia; Shi, Bingyin; Hou, Peng

    2011-01-01

    Lung cancer is the leading cause of cancer-related death worldwide. Genetic and epigenetic alterations have been identified frequently in lung cancer, such as promoter methylation, gene mutations and genomic amplification. However, the interaction between genetic and epigenetic events and their significance in lung tumorigenesis remains poorly understood. We determined the promoter methylation of 6 genes and PIK3CA amplification using quantitative methylation-specific PCR (Q-MSP) and real-time quantitative PCR, respectively, and explore the association of promoter methylation with PIK3CA amplification in a large cohort of clinically well-characterized non-small cell lung cancer (NSCLC). Highly frequent promoter methylation was observed in NSCLC. With 100% diagnostic specificity, excellent sensitivity, ranging from 45.8 to 84.1%, was found for each of the 6 genes. The promoter methylation was associated with histologic type. Methylation of CALCA, CDH1, DAPK1, and EVX2 was more common in squamous cell carcinomas (SCC) compared to adenocarcinomas (ADC). Conversely, there was a trend toward a higher frequency of RASSF1A methylation in ADC than SCC. In addition, PIK3CA amplification was frequently found in NSCLC, and was associated with certain clinicopathologic features, such as smoking history, histologic type and pleural indentation. Importantly, aberrant promoter methylation of certain genes was significantly associated with PIK3CA amplification. Our data showed highly frequent promoter methylation and PIK3CA amplification in Chinese NSCLC population, and first demonstrated the associations of gene methylation with PIK3CA amplification, suggesting that these epigenetic events may be a consequence of overactivation of PI3K/Akt pathway

  12. Simultaneous Aurora-A/STK15 overexpression and centrosome amplification induce chromosomal instability in tumour cells with a MIN phenotype

    International Nuclear Information System (INIS)

    Lentini, Laura; Amato, Angela; Schillaci, Tiziana; Di Leonardo, Aldo

    2007-01-01

    Genetic instability is a hallmark of tumours and preneoplastic lesions. The predominant form of genome instability in human cancer is chromosome instability (CIN). CIN is characterized by chromosomal aberrations, gains or losses of whole chromosomes (aneuploidy), and it is often associated with centrosome amplification. Centrosomes control cell division by forming a bipolar mitotic spindle and play an essential role in the maintenance of chromosomal stability. However, whether centrosome amplification could directly cause aneuploidy is not fully established. Also, alterations in genes required for mitotic progression could be involved in CIN. A major candidate is represented by Aurora-A/STK15 that associates with centrosomes and is overexpressed in several types of human tumour. Centrosome amplification were induced by hydroxyurea treatment and visualized by immunofluorescence microscopy. Aurora-A/STK15 ectopic expression was achieved by retroviral infection and puromycin selection in HCT116 tumour cells. Effects of Aurora-A/STK15 depletion on centrosome status and ploidy were determined by Aurora-A/STK15 transcriptional silencing by RNA interference. Changes in the expression levels of some mitotic genes were determined by Real time RT-PCR. We investigated whether amplification of centrosomes and overexpression of Aurora-A/STK15 induce CIN using as a model system a colon carcinoma cell line (HCT116). We found that in HCT116 cells, chromosomally stable and near diploid cells harbouring a MIN phenotype, centrosome amplification induced by hydroxyurea treatment is neither maintained nor induces aneuploidy. On the contrary, ectopic overexpression of Aurora-A/STK15 induced supernumerary centrosomes and aneuploidy. Aurora-A/STK15 transcriptional silencing by RNA interference in cells ectopically overexpressing this kinase promptly decreased cell numbers with supernumerary centrosomes and aneuploidy. Our results show that centrosome amplification alone is not sufficient

  13. Clinical application of somatosensory amplification in psychosomatic medicine

    Directory of Open Access Journals (Sweden)

    Nakao Mutsuhiro

    2007-10-01

    Full Text Available Abstract Many patients with somatoform disorders are frequently encountered in psychosomatic clinics as well as in primary care clinics. To assess such patients objectively, the concept of somatosensory amplification may be useful. Somatosensory amplification refers to the tendency to experience a somatic sensation as intense, noxious, and disturbing. It may have a role in a variety of medical conditions characterized by somatic symptoms that are disproportionate to demonstrable organ pathology. It may also explain some of the variability in somatic symptomatology found among different patients with the same serious medical disorder. It has been assessed with a self-report questionnaire, the Somatosensory Amplification Scale. This instrument was developed in a clinical setting in the U.S., and the reliability and validity of the Japanese and Turkish versions have been confirmed as well. Many studies have attempted to clarify the specific role of somatosensory amplification as a pathogenic mechanism in somatization. It has been reported that somatosensory amplification does not correlate with heightened sensitivity to bodily sensations and that emotional reactivity exerts its influence on somatization via a negatively biased reporting style. According to our recent electroencephalographic study, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interoceptive sensitivity. The concept of somatosensory amplification can be useful as an indicator of somatization in the therapy of a broad range of disorders, from impaired self-awareness to various psychiatric disorders. It also provides useful information for choosing appropriate pharmacological or psychological therapy. While somatosensory amplification has a role in the presentation of somatic symptoms, it is closely associated with other factors, namely, anxiety, depression, and alexithymia that may also influence the same

  14. Linear and exponential TAIL-PCR: a method for efficient and quick amplification of flanking sequences adjacent to Tn5 transposon insertion sites.

    Science.gov (United States)

    Jia, Xianbo; Lin, Xinjian; Chen, Jichen

    2017-11-02

    Current genome walking methods are very time consuming, and many produce non-specific amplification products. To amplify the flanking sequences that are adjacent to Tn5 transposon insertion sites in Serratia marcescens FZSF02, we developed a genome walking method based on TAIL-PCR. This PCR method added a 20-cycle linear amplification step before the exponential amplification step to increase the concentration of the target sequences. Products of the linear amplification and the exponential amplification were diluted 100-fold to decrease the concentration of the templates that cause non-specific amplification. Fast DNA polymerase with a high extension speed was used in this method, and an amplification program was used to rapidly amplify long specific sequences. With this linear and exponential TAIL-PCR (LETAIL-PCR), we successfully obtained products larger than 2 kb from Tn5 transposon insertion mutant strains within 3 h. This method can be widely used in genome walking studies to amplify unknown sequences that are adjacent to known sequences.

  15. Rapid detection of Brucella spp. using loop-mediated isothermal amplification (LAMP).

    Science.gov (United States)

    Chen, Shouyi; Li, Xunde; Li, Juntao; Atwill, Edward R

    2013-01-01

    Brucella spp. are facultative intracellular bacteria that cause zoonotic disease of brucellosis worldwide. Livestock that are most vulnerable to brucellosis include cattle, goats, and pigs. Brucella spp. cause serious health problems to humans and animals and economic losses to the livestock industry. Traditional methods for detection of Brucella spp. take 48-72 h (Kumar et al., J Commun Dis 29:131-137, 1997; Barrouin-Melo et al., Res Vet Sci 83:340-346, 2007) that do not meet the food industry's need of rapid detection. Therefore, there is an urgent need of fast, specific, sensitive, and inexpensive method for diagnosing of Brucella spp. Loop-mediated isothermal amplification (LAMP) is a method to amplify nucleic acid at constant temperatures. Amplification can be detected by visual detection, fluorescent stain, turbidity, and electrophoresis. We targeted at the Brucella-specific gene omp25 and designed LAMP primers for detection of Brucella spp. Amplification of DNA with Bst DNA polymerase can be completed at 65 °C in 60 min. Amplified products can be detected by SYBR Green I stain and 2.0% agarose gel electrophoresis. The LAMP method is feasible for detection of Brucella spp. from blood and milk samples.

  16. Amplification volume reduction on DNA database samples using FTA™ Classic Cards.

    Science.gov (United States)

    Wong, Hang Yee; Lim, Eng Seng Simon; Tan-Siew, Wai Fun

    2012-03-01

    The DNA forensic community always strives towards improvements in aspects such as sensitivity, robustness, and efficacy balanced with cost efficiency. Therefore our laboratory decided to study the feasibility of PCR amplification volume reduction using DNA entrapped in FTA™ Classic Card and to bring cost savings to the laboratory. There were a few concerns the laboratory needed to address. First, the kinetics of the amplification reaction could be significantly altered. Second, an increase in sensitivity might affect interpretation due to increased stochastic effects even though they were pristine samples. Third, statics might cause FTA punches to jump out of its allocated well into another thus causing sample-to-sample contamination. Fourth, the size of the punches might be too small for visual inspection. Last, there would be a limit to the extent of volume reduction due to evaporation and the possible need of re-injection of samples for capillary electrophoresis. The laboratory had successfully optimized a reduced amplification volume of 10 μL for FTA samples. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Direct amplification of casework bloodstains using the Promega PowerPlex(®) 21 PCR amplification system.

    Science.gov (United States)

    Gray, Kerryn; Crowle, Damian; Scott, Pam

    2014-09-01

    A significant number of evidence items submitted to Forensic Science Service Tasmania (FSST) are blood swabs or bloodstained items. Samples from these items routinely undergo phenol:chloroform:isoamyl alcohol organic extraction and quantitative Polymerase Chain Reaction (qPCR) testing prior to PowerPlex(®) 21 amplification. This multi-step process has significant cost and timeframe implications in a fiscal climate of tightening government budgets, pressure towards improved operating efficiencies, and an increasing emphasis on rapid techniques better supporting intelligence-led policing. Direct amplification of blood and buccal cells on cloth and Whatman FTA™ card with PowerPlex(®) 21 has already been successfully implemented for reference samples, eliminating the requirement for sample pre-treatment. Scope for expanding this method to include less pristine casework blood swabs and samples from bloodstained items was explored in an endeavour to eliminate lengthy DNA extraction, purification and qPCR steps for a wider subset of samples. Blood was deposited onto a range of substrates including those historically found to inhibit STR amplification. Samples were collected with micro-punch, micro-swab, or both. The potential for further fiscal savings via reduced volume amplifications was assessed by amplifying all samples at full and reduced volume (25 and 13μL). Overall success rate data showed 80% of samples yielded a complete profile at reduced volume, compared to 78% at full volume. Particularly high success rates were observed for the blood on fabric/textile category with 100% of micro-punch samples yielding complete profiles at reduced volume and 85% at full volume. Following the success of this trial, direct amplification of suitable casework blood samples has been implemented at reduced volume. Significant benefits have been experienced, most noticeably where results from crucial items have been provided to police investigators prior to interview of

  18. Active control of noise amplification in the flow over a square leading-edge flat plate utilizing DBD plasma actuator

    Science.gov (United States)

    Yadong, HUANG; Benmou, ZHOU

    2018-05-01

    Perturbation is generally considered as the flow noise, and its energy can gain transient growth in the separation bubble. The amplified perturbations may cause unstable Kelvin–Helmohltz vortices which induce the three-dimensional transition. Active control of noise amplification via dielectric barrier discharge plasma actuator in the flow over a square leading-edge flat plate is numerically studied. The actuator is installed near the plate leading-edge where the separation bubble is formed. The maximum energy amplification of perturbations is positively correlated with the separation bubble scale which decreases with the increasing control parameters. As the magnitude of noise amplification is reduced, the laminar-turbulent transition is successfully suppressed.

  19. Amplification of hot electron flow by the surface plasmon effect on metal–insulator–metal nanodiodes

    International Nuclear Information System (INIS)

    Lee, Changhwan; Nedrygailov, Ievgen I; Keun Lee, Young; Lee, Hyosun; Young Park, Jeong; Ahn, Changui; Jeon, Seokwoo

    2015-01-01

    Au–TiO_2–Ti nanodiodes with a metal–insulator–metal structure were used to probe hot electron flows generated upon photon absorption. Hot electrons, generated when light is absorbed in the Au electrode of the nanodiode, can travel across the TiO_2, leading to a photocurrent. Here, we demonstrate amplification of the hot electron flow by (1) localized surface plasmon resonance on plasmonic nanostructures fabricated by annealing the Au–TiO_2–Ti nanodiodes, and (2) reducing the thickness of the TiO_2. We show a correlation between changes in the morphology of the Au electrodes caused by annealing and amplification of the photocurrent. Based on the exponential dependence of the photocurrent on TiO_2 thickness, the transport mechanism for the hot electrons across the nanodiodes is proposed. (paper)

  20. Study of C-MYC amplification and expression in Iranian gastric cancer samples using CISH and IHC methods.

    Science.gov (United States)

    Khaleghian, Malihea; Jahanzad, Issa; Shakoori, Abbas; Ardalan, Farid Azmoudeh; Azimi, Cyrus

    2015-01-01

    Gastric cancer is the fourth most frequent malignancy and the second cause of cancer-related mortality worldwide. It has been suggested that in gastric carcinogenesis, the C-MYC gene has an important function. The objective of this study is to establish the preference of Chromogenic in situ hybridization (CISH) and Immunohistochemistry (IHC) in the diagnosis and prognosis of gastric cancer. Samples comprised of 50 randomly selected patients of whom 40 were male and 10 female. To evaluate the MYC copy number and its protein expression, CISH and IHC analyses were performed for 50 gastric adenocarcinomas, in Iran. The location of the tumor in 64% of the patients was the fundus, and in 72% of patients, the tumors were of a diffuse type; 22 samples showed no amplification, and 28 samples were with amplification. MYC immunoreactivity was observed in 13 samples. Twelve samples showed both MYC amplification and MYC immunoreactivity. In addition, among the 28 CISH+ samples, 12 samples had positive signals for IHC and 16 samples had negative signals for IHC. A majority of the IHC-negative patients had no amplification, but only one patient with IHC positive had no amplification. Our conclusion was that for the management and treatment of gastric cancer, and for special attention of clinicians, for prognosis and tumor progression, the CISH was a better and more feasible test than IHC, in regard to the sensitivity and specificity.

  1. Study of C-MYC amplification and expression in Iranian gastric cancer samples using CISH and IHC methods

    Directory of Open Access Journals (Sweden)

    Malihea Khaleghian

    2015-01-01

    Full Text Available Background: Gastric cancer is the fourth most frequent malignancy and the second cause of cancer-related mortality worldwide. It has been suggested that in gastric carcinogenesis, the C-MYC gene has an important function. The objective of this study is to establish the preference of Chromogenic in situ hybridization (CISH and Immunohistochemistry (IHC in the diagnosis and prognosis of gastric cancer. Materials and Methods: Samples comprised of 50 randomly selected patients of whom 40 were male and 10 female. To evaluate the MYC copy number and its protein expression, CISH and IHC analyses were performed for 50 gastric adenocarcinomas, in Iran. Results: The location of the tumor in 64% of the patients was the fundus, and in 72% of patients, the tumors were of a diffuse type; 22 samples showed no amplification, and 28 samples were with amplification. MYC immunoreactivity was observed in 13 samples. Twelve samples showed both MYC amplification and MYC immunoreactivity. In addition, among the 28 CISH+ samples, 12 samples had positive signals for IHC and 16 samples had negative signals for IHC. A majority of the IHC-negative patients had no amplification, but only one patient with IHC positive had no amplification. Conclusion: Our conclusion was that for the management and treatment of gastric cancer, and for special attention of clinicians, for prognosis and tumor progression, the CISH was a better and more feasible test than IHC, in regard to the sensitivity and specificity.

  2. HER2 amplification, overexpression and score criteria in esophageal adenocarcinoma

    Science.gov (United States)

    Hu, Yingchuan; Bandla, Santhoshi; Godfrey, Tony E.; Tan, Dongfeng; Luketich, James D.; Pennathur, Arjun; Qiu, Xing; Hicks, David G.; Peters, Jeffrey; Zhou, Zhongren

    2011-01-01

    The HER2 oncogene was recently reported to be amplified and overexpressed in esophageal adenocarcinoma. However, the relationship of HER2 amplification in esophageal adenocarcinoma with prognosis has not been well defined. The scoring systems for clinically evaluating HER2 in esophageal adenocarcinoma are not established. The aims of the study were to establish a HER2 scoring system and comprehensively investigate HER2 amplification and overexpression in esophageal adenocarcinoma and its precursor lesion. Using a tissue microarray, containing 116 cases of esophageal adenocarcinoma, 34 cases of BE, 18 cases of low grade dysplasia and 15 cases of high grade dysplasia, HER2 amplification and overexpression were analyzed by HercepTest and CISH methods. The amplification frequency in an independent series of 116 esophageal adenocarcinoma samples was also analyzed using Affymetrix SNP 6.0 microarrays. In our studies, we have found that HER2 amplification does not associate with poor prognosis in total 232 esophageal adenocarcinoma patients by CISH and high density microarrays. We further confirm the similar frequency of HER2 amplification by CISH (18.10%; 21/116) and SNP 6.0 microarrays (16.4%, 19/116) in esophageal adenocarcinoma. HER2 protein overexpression was observed in 12.1 % (14/116) of esophageal adenocarcinoma and 6.67% (1/15) of HGD. No HER2 amplification or overexpression was identified in BE or LGD. All HER2 protein overexpression cases showed HER2 gene amplification. Gene amplification was found to be more frequent by CISH than protein overexpression in esophageal adenocarcinoma (18.10% vs 12.9%). A modified two-step model for esophageal adenocarcinoma HER-2 testing is recommend for clinical esophageal adenocarcinoma HER-2 trial. PMID:21460800

  3. Amplification and chromosomal dispersion of human endogenous retroviral sequences

    International Nuclear Information System (INIS)

    Steele, P.E.; Martin, M.A.; Rabson, A.B.; Bryan, T.; O'Brien, S.J.

    1986-01-01

    Endogenous retroviral sequences have undergone amplification events involving both viral and flanking cellular sequences. The authors cloned members of an amplified family of full-length endogenous retroviral sequences. Genomic blotting, employing a flanking cellular DNA probe derived from a member of this family, revealed a similar array of reactive bands in both humans and chimpanzees, indicating that an amplification event involving retroviral and associated cellular DNA sequences occurred before the evolutionary separation of these two primates. Southern analyses of restricted somatic cell hybrid DNA preparations suggested that endogenous retroviral segments are widely dispersed in the human genome and that amplification and dispersion events may be linked

  4. PCR amplification on microarrays of gel immobilized oligonucleotides

    Science.gov (United States)

    Strizhkov, Boris; Tillib, Sergei; Mikhailovich, Vladimir; Mirzabekov, Andrei

    2003-11-04

    The invention relates two general methods for performing PCR amplification, combined with the detection and analysis of the PCR products on a microchip. In the first method, the amplification occurs both outside and within a plurality of gel pads on a microchip, with at least one oligonucleotide primer immobilized in a gel pad. In the second method, PCR amplification also takes place within gel pads on a microchip, but the pads are surrounded by a hydrophobic liquid such as that which separates the individual gel pads into environments which resemble micro-miniaturized test tubes.

  5. Towards rapid prototyped convective microfluidic DNA amplification platform

    Science.gov (United States)

    Ajit, Smrithi; Praveen, Hemanth Mithun; Puneeth, S. B.; Dave, Abhishek; Sesham, Bharat; Mohan, K. N.; Goel, Sanket

    2017-02-01

    Today, Polymerase Chain Reaction (PCR) based DNA amplification plays an indispensable role in the field of biomedical research. Its inherent ability to exponentially amplify sample DNA has proven useful for the identification of virulent pathogens like those causing Multiple Drug-Resistant Tuberculosis (MDR-TB). The intervention of Microfluidics technology has revolutionized the concept of PCR from being a laborious and time consuming process into one that is faster, easily portable and capable of being multifunctional. The Microfluidics based PCR outweighs its traditional counterpart in terms of flexibility of varying reaction rate, operation simplicity, need of a fraction of volume and capability of being integrated with other functional elements. The scope of the present work involves the development of a real-time continuous flow microfluidic device, fabricated by 3D printing-governed rapid prototyping method, eventually leading to an automated and robust platform to process multiple DNA samples for detection of MDRTB-associated mutations. The thermal gradient characteristic to the PCR process is produced using peltier units appropriate to the microfluidic environment fully monitored and controlled by a low cost controller driven by a Data Acquisition System. The process efficiency achieved in the microfluidic environment in terms of output per cycle is expected to be on par with the traditional PCR and capable of earning the additional advantages of being faster and minimizing the handling.

  6. Small sample whole-genome amplification

    Science.gov (United States)

    Hara, Christine; Nguyen, Christine; Wheeler, Elizabeth; Sorensen, Karen; Arroyo, Erin; Vrankovich, Greg; Christian, Allen

    2005-11-01

    Many challenges arise when trying to amplify and analyze human samples collected in the field due to limitations in sample quantity, and contamination of the starting material. Tests such as DNA fingerprinting and mitochondrial typing require a certain sample size and are carried out in large volume reactions; in cases where insufficient sample is present whole genome amplification (WGA) can be used. WGA allows very small quantities of DNA to be amplified in a way that enables subsequent DNA-based tests to be performed. A limiting step to WGA is sample preparation. To minimize the necessary sample size, we have developed two modifications of WGA: the first allows for an increase in amplified product from small, nanoscale, purified samples with the use of carrier DNA while the second is a single-step method for cleaning and amplifying samples all in one column. Conventional DNA cleanup involves binding the DNA to silica, washing away impurities, and then releasing the DNA for subsequent testing. We have eliminated losses associated with incomplete sample release, thereby decreasing the required amount of starting template for DNA testing. Both techniques address the limitations of sample size by providing ample copies of genomic samples. Carrier DNA, included in our WGA reactions, can be used when amplifying samples with the standard purification method, or can be used in conjunction with our single-step DNA purification technique to potentially further decrease the amount of starting sample necessary for future forensic DNA-based assays.

  7. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    Directory of Open Access Journals (Sweden)

    Takeo Yoshimura

    Full Text Available Rolling circle amplification (RCA generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same.

  8. Static and Dynamic Amplification Using Strong Mechanical Coupling

    KAUST Repository

    Ilyas, Saad; Jaber, Nizar; Younis, Mohammad I.

    2016-01-01

    Amplifying the signal-to-noise ratio of resonant sensors is vital toward the effort to miniaturize devices into the sub-micro and nano regimes. In this paper, we demonstrate theoretically and experimentally, amplification through mechanically

  9. Three-dimensional Simulation of Backward Raman Amplification

    International Nuclear Information System (INIS)

    Balakin, A.A.; Fraiman, G.M.; Fisch, N.J.

    2005-01-01

    Three-dimensional (3-D) simulations for the Backward Raman Amplification (BRA) are presented. The images illustrate the effects of pump depletion, pulse diffraction, non-homogeneous plasma density, and plasma ionization

  10. Period doubling induced by thermal noise amplification in genetic circuits

    KAUST Repository

    Ruocco, G.; Fratalocchi, Andrea

    2014-01-01

    . In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification

  11. Cross-genus amplification and characterisation of microsatellite loci ...

    African Journals Online (AJOL)

    Cross-genus amplification and characterisation of microsatellite loci in the little free tailed bat, Chaerephon pumilus s. l. (Molossidae) from South Eastern Africa. Theshnie Naidoo, Angus Macdonald, Jennifer M Lamb ...

  12. DNA amplification is rare in normal human cells

    International Nuclear Information System (INIS)

    Wright, J.A.; Watt, F.M.; Hudson, D.L.; Stark, G.R.; Smith, H.S.; Hancock, M.C.

    1990-01-01

    Three types of normal human cells were selected in tissue culture with three drugs without observing a single amplification event from a total of 5 x 10 8 cells. No drug-resistant colonies were observed when normal foreskin keratinocytes were selected with N-(phosphonacetyl)-L-aspartate or with hydroxyurea or when normal mammary epithelial cells were selected with methotrexate. Some slightly resistant colonies with limited potential for growth were obtained when normal diploid fibroblast cells derived from fetal lung were selected with methotrexate or hydroxyurea but careful copy-number analysis of the dihydrofolate reductase and ribonucleotide reductase genes revealed no evidence of amplification. The rarity of DNA amplification in normal human cells contrasts strongly with the situation in tumors and in established cell lines, where amplification of onogenes and of genes mediating drug resistance is frequent. The results suggest that tumors and cell lines have acquired the abnormal ability to amplify DNA with high frequency

  13. Centrosome Amplification Increases Single-Cell Branching in Post-mitotic Cells.

    Science.gov (United States)

    Ricolo, Delia; Deligiannaki, Myrto; Casanova, Jordi; Araújo, Sofia J

    2016-10-24

    Centrosome amplification is a hallmark of cancer, although we are still far from understanding how this process affects tumorigenesis [1, 2]. Besides the contribution of supernumerary centrosomes to mitotic defects, their biological effects in the post-mitotic cell are not well known. Here, we exploit the effects of centrosome amplification in post-mitotic cells during single-cell branching. We show that Drosophila tracheal cells with extra centrosomes branch more than wild-type cells. We found that mutations in Rca1 and CycA affect subcellular branching, causing tracheal tip cells to form more than one subcellular lumen. We show that Rca1 and CycA post-mitotic cells have supernumerary centrosomes and that other mutant conditions that increase centrosome number also show excess of subcellular lumen branching. Furthermore, we show that de novo lumen formation is impaired in mutant embryos with fewer centrioles. The data presented here define a requirement for the centrosome as a microtubule-organizing center (MTOC) for the initiation of subcellular lumen formation. We propose that centrosomes are necessary to drive subcellular lumen formation. In addition, centrosome amplification increases single-cell branching, a process parallel to capillary sprouting in blood vessels [3]. These results shed new light on how centrosomes can contribute to pathology independently of mitotic defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Energy Flux in the Cochlea: Evidence Against Power Amplification of the Traveling Wave.

    Science.gov (United States)

    van der Heijden, Marcel; Versteegh, Corstiaen P C

    2015-10-01

    Traveling waves in the inner ear exhibit an amplitude peak that shifts with frequency. The peaking is commonly believed to rely on motile processes that amplify the wave by inserting energy. We recorded the vibrations at adjacent positions on the basilar membrane in sensitive gerbil cochleae and tested the putative power amplification in two ways. First, we determined the energy flux of the traveling wave at its peak and compared it to the acoustic power entering the ear, thereby obtaining the net cochlear power gain. For soft sounds, the energy flux at the peak was 1 ± 0.6 dB less than the middle ear input power. For more intense sounds, increasingly smaller fractions of the acoustic power actually reached the peak region. Thus, we found no net power amplification of soft sounds and a strong net attenuation of intense sounds. Second, we analyzed local wave propagation on the basilar membrane. We found that the waves slowed down abruptly when approaching their peak, causing an energy densification that quantitatively matched the amplitude peaking, similar to the growth of sea waves approaching the beach. Thus, we found no local power amplification of soft sounds and strong local attenuation of intense sounds. The most parsimonious interpretation of these findings is that cochlear sensitivity is not realized by amplifying acoustic energy, but by spatially focusing it, and that dynamic compression is realized by adjusting the amount of dissipation to sound intensity.

  15. Detection of biological molecules using chemical amplification and optical sensors

    Science.gov (United States)

    Van Antwerp, William Peter; Mastrototaro, John Joseph

    2000-01-01

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.

  16. Pulse Distortion in Saturated Fiber Optical Parametric Chirped Pulse Amplification

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Da Ros, Francesco; Rottwitt, Karsten

    2012-01-01

    Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation.......Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation....

  17. Current amplification models of sensorineurall and conductive hearing loss

    OpenAIRE

    Ostojić, Sanja; Mikić, Branka; Mirić, Danica

    2012-01-01

    The main function of a hearing aid is to improve auditory and language abilities of hearing impaired users. The amplification model has to be adapted according to age, degree and type of hearing loss. The goal of this paper is to analyze the current amplification models of sensorineural and conductive hearing loss which can provide a high quality of speech perception and sounds at any degree of hearing loss. The BAHA is a surgically implantable system for treatment of conductive hearing loss ...

  18. Development of a recombinase polymerase amplification assay for Vibrio parahaemolyticus detection with an internal amplification control.

    Science.gov (United States)

    Yang, Huan-Lan; Wei, Shuang; Gooneratne, Ravi; Mutukumira, Anthony N; Ma, Xue-Jun; Tang, Shu-Ze; Wu, Xi-Yang

    2018-04-01

    A novel RPA-IAC assay using recombinase polymerase and an internal amplification control (IAC) for Vibrio parahaemolyticus detection was developed. Specific primers were designed based on the coding sequence for the toxR gene in V. parahaemolyticus. The recombinase polymerase amplification (RPA) reaction was conducted at a constant low temperature of 37 °C for 20 min. Assay specificity was validated by using 63 Vibrio strains and 10 non-Vibrio bacterial species. In addition, a competitive IAC was employed to avoid false-negative results, which co-amplified simultaneously with the target sequence. The sensitivity of the assay was determined as 3 × 10 3 CFU/mL, which is decidedly more sensitive than the established PCR method. This method was then used to test seafood samples that were collected from local markets. Seven out of 53 different raw seafoods were detected as V. parahaemolyticus-positive, which were consistent with those obtained using traditional culturing method and biochemical assay. This novel RPA-IAC assay provides a rapid, specific, sensitive, and more convenient detection method for V. parahaemolyticus.

  19. Realization of the conceptual ideal for x-ray amplification

    Energy Technology Data Exchange (ETDEWEB)

    Borisov, Alex B; Racz, Ervin; Zhang Ping; McCorkindale, John C; Khan, Shahab F; Poopalasingam, Sankar; Zhao Ji; Rhodes, Charles K [Laboratory for X-Ray Microimaging and Bioinformatics, Department of Physics, University of Illinois at Chicago, Chicago, IL 60607-7059 (United States)

    2008-05-28

    The Xe(L) system is an amplifier with fundamentally different dynamic characteristics from all previously developed laser amplifiers; it represents the conceptual ideal through full utilization of the Kramers-Kronig relations that fundamentally couple the dispersive and absorptive components. The dispersive response of the system, through optimal governance of the power compression, rules the amplification and establishes a minimum gain for the amplifier. Accordingly, the amplification requires a minimum value of the dispersion to be surpassed; the corresponding gain follows automatically. As a leading consequence, since this minimum gain is sufficiently high, the key experimental observation is the uniform presence of saturated amplification signaled by strong spectral hole burning on all transitions exhibiting amplification, including double-vacancy lines. This cardinal signature demonstrates that the amplification is legislated by the saturated gain g{sub s}, not the corresponding small signal value g{sub 0}. The chief outcome is that explosive dispersion yields perforce explosive amplification and the efficient generation of maximally bright coherent power.

  20. Targeting MET Amplification as a New Oncogenic Driver

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hisato [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Okamoto, Isamu, E-mail: okamotoi@kokyu.med.kyushu-u.ac.jp [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Center for Clinical and Translational Research, Kyushu University Hospital, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582 (Japan); Okamoto, Wataru [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Division of Transrlational Research, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577 (Japan); Tanizaki, Junko [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, HIM223, 450 Brookline Avenue, Boston, MA 02215 (United States); Nakagawa, Kazuhiko [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Nishio, Kazuto [Department of Genome Biology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan)

    2014-07-22

    Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as “oncogene addiction”. A new generation of drugs that selectively target such “driver oncogenes” manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an “oncogenic driver” and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy.

  1. Targeting MET Amplification as a New Oncogenic Driver

    International Nuclear Information System (INIS)

    Kawakami, Hisato; Okamoto, Isamu; Okamoto, Wataru; Tanizaki, Junko; Nakagawa, Kazuhiko; Nishio, Kazuto

    2014-01-01

    Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as “oncogene addiction”. A new generation of drugs that selectively target such “driver oncogenes” manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an “oncogenic driver” and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy

  2. Population diversity of ammonium oxidizers investigated by specific PCR amplification

    Science.gov (United States)

    Ward, B.B.; Voytek, M.A.; Witzel, K.-P.

    1997-01-01

    The species composition of ammonia-oxidizing bacteria in aquatic environments was investigated using PCR primers for 16S rRNA genes to amplify specific subsets of the total ammonia-oxidizer population. The specificity of the amplification reactions was determined using total genomic DNA from known nitrifying strains and non-nitrifying strains identified as having similar rDNA sequences. Specificity of amplification was determined both for direct amplification, using the nitrifier specific primers, and with nested amplification, in which the nitrifier primers were used to reamplify a fragment obtained from direct amplification with Eubacterial universal primers. The present level of specificity allows the distinction between Nitrosomonas europaea, Nitrosomonas sp. (marine) and the other known ammonia-oxidizers in the beta subclass of the Proteobacteria. Using total DNA extracted from natural samples, we used direct amplification to determine presence/absence of different species groups. Species composition was found to differ among depths in vertical profiles of lake samples and among samples and enrichments from various other aquatic environments. Nested PCR yielded several more positive reactions, which implies that nitrifier DNA was present in most samples, but often at very low levels.

  3. Culture-Negative Neonatal Meningitis and Endocarditis Caused by Streptococcus agalactiae

    OpenAIRE

    Nègre, Valérie Lefranc; Colin-Gorski, Anne-Marie; Magnier, Suzel; Maisonneuve, Lydia; Aujard, Yannick; Bingen, Edouard; Bonacorsi, Stéphane

    2004-01-01

    We describe a case of culture-negative meningitis and endocarditis caused by Streptococcus agalactiae in a 27-day-old boy. S. agalactiae was detected in cerebrospinal fluid and serum by broad-spectrum PCR amplification.

  4. ASAP: Amplification, sequencing & annotation of plastomes

    Directory of Open Access Journals (Sweden)

    Folta Kevin M

    2005-12-01

    Full Text Available Abstract Background Availability of DNA sequence information is vital for pursuing structural, functional and comparative genomics studies in plastids. Traditionally, the first step in mining the valuable information within a chloroplast genome requires sequencing a chloroplast plasmid library or BAC clones. These activities involve complicated preparatory procedures like chloroplast DNA isolation or identification of the appropriate BAC clones to be sequenced. Rolling circle amplification (RCA is being used currently to amplify the chloroplast genome from purified chloroplast DNA and the resulting products are sheared and cloned prior to sequencing. Herein we present a universal high-throughput, rapid PCR-based technique to amplify, sequence and assemble plastid genome sequence from diverse species in a short time and at reasonable cost from total plant DNA, using the large inverted repeat region from strawberry and peach as proof of concept. The method exploits the highly conserved coding regions or intergenic regions of plastid genes. Using an informatics approach, chloroplast DNA sequence information from 5 available eudicot plastomes was aligned to identify the most conserved regions. Cognate primer pairs were then designed to generate ~1 – 1.2 kb overlapping amplicons from the inverted repeat region in 14 diverse genera. Results 100% coverage of the inverted repeat region was obtained from Arabidopsis, tobacco, orange, strawberry, peach, lettuce, tomato and Amaranthus. Over 80% coverage was obtained from distant species, including Ginkgo, loblolly pine and Equisetum. Sequence from the inverted repeat region of strawberry and peach plastome was obtained, annotated and analyzed. Additionally, a polymorphic region identified from gel electrophoresis was sequenced from tomato and Amaranthus. Sequence analysis revealed large deletions in these species relative to tobacco plastome thus exhibiting the utility of this method for structural and

  5. Development of Loop-Mediated Isothermal Amplification Assay for Detection of Entamoeba histolytica▿

    Science.gov (United States)

    Liang, Shih-Yu; Chan, Yun-Hsien; Hsia, Kan-Tai; Lee, Jing-Lun; Kuo, Ming-Chu; Hwa, Kuo-Yuan; Chan, Chi-Wen; Chiang, Ting-Yi; Chen, Jung-Sheng; Wu, Fang-Tzy; Ji, Dar-Der

    2009-01-01

    A novel one-step, closed-tube, loop-mediated isothermal amplification (LAMP) assay for detecting Entamoeba histolytica, one of the leading causes of morbidity in developing countries, was developed. The sensitivity of the LAMP assay is 1 parasite per reaction. A total of 130 clinical samples were analyzed, and the results compared with those of conventional nested PCR to validate the practicability of this assay. No DNA was amplified from other diarrheal pathogens, such as other Entamoeba species, bacteria, and viruses. These results indicate that LAMP is a rapid, simple, and valuable diagnostic tool for epidemiological studies of amebiasis. PMID:19321720

  6. Alternative Chemical Amplification Methods for Peroxy Radical Detection

    Science.gov (United States)

    Wood, E. C. D.

    2014-12-01

    Peroxy radicals (HO2, CH3O2, etc.) are commonly detected by the chemical amplification technique, in which ambient air is mixed with high concentrations of CO and NO, initiating a chain reaction that produces 30 - 200 NO2 molecules per sampled peroxy radical. The NO2 is then measured by one of several techniques. With the exception of CIMS-based techniques, the chemical amplification method has undergone only incremental improvements since it was first introduced in 1982. The disadvantages of the technique include the need to use high concentrations of CO and the greatly reduced sensitivity of the amplification chain length in the presence of water vapor. We present a new chemical amplification scheme in which either ethane or acetaldehyde is used in place of CO, with the NO2 product detected using Cavity Attenuated Phase Shift spectroscopy (CAPS). Under dry conditions, the amplification factor of the alternative amplifiers are approximately six times lower than the CO-based amplifier. The relative humidity "penalty" is not as severe, however, such that at typical ambient relative humidity (RH) values the amplification factor is within a factor of three of the CO-based amplifier. Combined with the NO2 sensitivity of CAPS and a dual-channel design, the detection limit of the ethane amplifier is less than 2 ppt (1 minute average, signal-to-noise ratio 2). The advantages of these alternative chemical amplification schemes are improved safety, a reduced RH correction, and increased sensitivity to organic peroxy radicals relative to HO2.

  7. Quantitative measurement of a candidate serum biomarker peptide derived from α2-HS-glycoprotein, and a preliminary trial of multidimensional peptide analysis in females with pregnancy-induced hypertension.

    Science.gov (United States)

    Hamamura, Kensuke; Yanagida, Mitsuaki; Ishikawa, Hitoshi; Banzai, Michio; Yoshitake, Hiroshi; Nonaka, Daisuke; Tanaka, Kenji; Sakuraba, Mayumi; Miyakuni, Yasuka; Takamori, Kenji; Nojima, Michio; Yoshida, Koyo; Fujiwara, Hiroshi; Takeda, Satoru; Araki, Yoshihiko

    2018-03-01

    Purpose We previously attempted to develop quantitative enzyme-linked immunosorbent assay (ELISA) systems for the PDA039/044/071 peptides, potential serum disease biomarkers (DBMs) of pregnancy-induced hypertension (PIH), primarily identified by a peptidomic approach (BLOTCHIP®-mass spectrometry (MS)). However, our methodology did not extend to PDA071 (cysteinyl α2-HS-glycoprotein 341-367 ), due to difficulty to produce a specific antibody against the peptide. The aim of the present study was to establish an alternative PDA071 quantitation system using liquid chromatography-multiple reaction monitoring (LC-MRM)/MS, to explore the potential utility of PDA071 as a DBM for PIH. Methods We tested heat/acid denaturation methods in efforts to purify serum PDA071 and developed an LC-MRM/MS method allowing for specific quantitation thereof. We measured serum PDA071 concentrations, and these results were validated including by three-dimensional (3D) plotting against PDA039 (kininogen-1 439-456 )/044 (kininogen-1 438-456 ) concentrations, followed by discriminant analysis. Results PDA071 was successfully extracted from serum using a heat denaturation method. Optimum conditions for quantitation via LC-MRM/MS were developed; the assayed serum PDA071 correlated well with the BLOTCHIP® assay values. Although the PDA071 alone did not significantly differ between patients and controls, 3D plotting of PDA039/044/071 peptide concentrations and construction of a Jackknife classification matrix were satisfactory in terms of PIH diagnostic precision. Conclusions Combination analysis using both PDA071 and PDA039/044 concentrations allowed PIH diagnostic accuracy to be attained, and our method will be valuable in future pathophysiological studies of hypertensive disorders of pregnancy.

  8. DNA sequence responsible for the amplification of adjacent genes.

    Science.gov (United States)

    Pasion, S G; Hartigan, J A; Kumar, V; Biswas, D K

    1987-10-01

    A 10.3-kb DNA fragment in the 5'-flanking region of the rat prolactin (rPRL) gene was isolated from F1BGH(1)2C1, a strain of rat pituitary tumor cells (GH cells) that produces prolactin in response to 5-bromodeoxyuridine (BrdU). Following transfection and integration into genomic DNA of recipient mouse L cells, this DNA induced amplification of the adjacent thymidine kinase gene from Herpes simplex virus type 1 (HSV1TK). We confirmed the ability of this "Amplicon" sequence to induce amplification of other linked or unlinked genes in DNA-mediated gene transfer studies. When transferred into the mouse L cells with the 10.3-5'rPRL gene sequence of BrdU-responsive cells, both the human growth hormone and the HSV1TK genes are amplified in response to 5-bromodeoxyuridine. This observation is substantiated by BrdU-induced amplification of the cotransferred bacterial Neo gene. Cotransfection studies reveal that the BrdU-induced amplification capability is associated with a 4-kb DNA sequence in the 5'-flanking region of the rPRL gene of BrdU-responsive cells. These results demonstrate that genes of heterologous origin, linked or unlinked, and selected or unselected, can be coamplified when located within the amplification boundary of the Amplicon sequence.

  9. Magnetic field amplification in interstellar collisionless shock waves

    International Nuclear Information System (INIS)

    Chevalier, R.A.

    1977-01-01

    It is stated that it is commonly assumed that a simple compression of the magnetic field occurs in interstellar shock waves. Recent space observations of the Earth's bow shock have shown that turbulent amplification of the magnetic field can occur in a collisionless shock. It is shown here that radio observations of Tycho's supernova remnant indicate the presence of a shock wave with such magnetic field amplification. There is at present no theory for the microinstabilities that give rise to turbulent amplification of the magnetic field. Despite the lack of theoretical understanding the possibility of field amplification in interstellar shock waves is here considered. In Tycho's supernova remnant there is evidence for the presence of a collisionless shock, and this is discussed. On the basis of observations of the Earth's bow shock, it is expected that turbulent magnetic field amplification occurs in the shock wave of this remnant, and this is supported by radio observations of the remnant. Consideration is given as to what extent the magnetic field is amplified in the shock wave on the basis of the non-thermal radio flux. (U.K.)

  10. Modeling the amplification dynamics of human Alu retrotransposons.

    Directory of Open Access Journals (Sweden)

    Dale J Hedges

    2005-09-01

    Full Text Available Retrotransposons have had a considerable impact on the overall architecture of the human genome. Currently, there are three lineages of retrotransposons (Alu, L1, and SVA that are believed to be actively replicating in humans. While estimates of their copy number, sequence diversity, and levels of insertion polymorphism can readily be obtained from existing genomic sequence data and population sampling, a detailed understanding of the temporal pattern of retrotransposon amplification remains elusive. Here we pose the question of whether, using genomic sequence and population frequency data from extant taxa, one can adequately reconstruct historical amplification patterns. To this end, we developed a computer simulation that incorporates several known aspects of primate Alu retrotransposon biology and accommodates sampling effects resulting from the methods by which mobile elements are typically discovered and characterized. By modeling a number of amplification scenarios and comparing simulation-generated expectations to empirical data gathered from existing Alu subfamilies, we were able to statistically reject a number of amplification scenarios for individual subfamilies, including that of a rapid expansion or explosion of Alu amplification at the time of human-chimpanzee divergence.

  11. Modeling the amplification dynamics of human alu retrotransposons.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Retrotransposons have had a considerable impact on the overall architecture of the human genome. Currently, there are three lineages of retrotransposons (Alu, L1, and SVA that are believed to be actively replicating in humans. While estimates of their copy number, sequence diversity, and levels of insertion polymorphism can readily be obtained from existing genomic sequence data and population sampling, a detailed understanding of the temporal pattern of retrotransposon amplification remains elusive. Here we pose the question of whether, using genomic sequence and population frequency data from extant taxa, one can adequately reconstruct historical amplification patterns. To this end, we developed a computer simulation that incorporates several known aspects of primate Alu retrotransposon biology and accommodates sampling effects resulting from the methods by which mobile elements are typically discovered and characterized. By modeling a number of amplification scenarios and comparing simulation-generated expectations to empirical data gathered from existing Alu subfamilies, we were able to statistically reject a number of amplification scenarios for individual subfamilies, including that of a rapid expansion or explosion of Alu amplification at the time of human-chimpanzee divergence.

  12. Generation of recombinant pestiviruses using a full genome amplification strategy

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Bruun; Reimann, Ilona; Uttenthal, Åse

    Aim Complete genome amplification of viral RNA provides a new tool for generation of modified pestiviruses. We have recently reported a full genome amplification strategy for direct recovery of infectious pestivirus (Rasmussen et al., 2008). This comprised rescue of BDV strain “Gifhorn” from a full......-length RT-PCR amplicon demonstrating that long RT-PCR can be used for direct generation of an infectious pestivirus. The strategy is not limited to amplification of BDV “Gifhorn”, but can be further utilized for amplification of a diverse selection of pestivirus strains and for the generation of modified...... was reverse transcribed to cDNA at 50C for 90 minutes using SuperScript III reverse transcriptase (Invitrogen). Full-length PCR amplification was performed using primers specific for the extreme 5’- and 3’-ends of the viral genomes. A T7 promoter was incorporated in the 5’-primers for direct in vitro...

  13. Implementation of antimicrobial peptides for sample preparation prior to nucleic acid amplification in point-of-care settings.

    Science.gov (United States)

    Krõlov, Katrin; Uusna, Julia; Grellier, Tiia; Andresen, Liis; Jevtuševskaja, Jekaterina; Tulp, Indrek; Langel, Ülo

    2017-12-01

    A variety of sample preparation techniques are used prior to nucleic acid amplification. However, their efficiency is not always sufficient and nucleic acid purification remains the preferred method for template preparation. Purification is difficult and costly to apply in point-of-care (POC) settings and there is a strong need for more robust, rapid, and efficient biological sample preparation techniques in molecular diagnostics. Here, the authors applied antimicrobial peptides (AMPs) for urine sample preparation prior to isothermal loop-mediated amplification (LAMP). AMPs bind to many microorganisms such as bacteria, fungi, protozoa and viruses causing disruption of their membrane integrity and facilitate nucleic acid release. The authors show that incubation of E. coli with antimicrobial peptide cecropin P1 for 5 min had a significant effect on the availability of template DNA compared with untreated or even heat treated samples resulting in up to six times increase of the amplification efficiency. These results show that AMPs treatment is a very efficient sample preparation technique that is suitable for application prior to nucleic acid amplification directly within biological samples. Furthermore, the entire process of AMPs treatment was performed at room temperature for 5 min thereby making it a good candidate for use in POC applications.

  14. Detection of MYCN Gene Amplification in Neuroblastoma by Fluorescence In Situ Hybridization: A Pediatric Oncology Group Study

    Directory of Open Access Journals (Sweden)

    Prasad Mathew

    2001-01-01

    Full Text Available To assess the utility of fluorescence in situ hybridization (FISH for analysis of MYCN gene amplification in neuroblastoma, we compared this assay with Southern blot analysis using tumor specimens collected from 232 patients with presenting characteristics typical of this disease. The FISH technique identified MYCN amplification in 47 cases, compared with 39 by Southern blotting, thus increasing the total number of positive cases by 21%. The major cause of discordancy was a low fraction of tumor cells (≤30% replacement in clinical specimens, which prevented an accurate estimate of MYCN copy number by Southern blotting. With FISH, by contrast, it was possible to analyze multiple interphase nuclei of tumor cells, regardless of the proportion of normal peripheral blood, bone marrow, or stromal cells in clinical samples. Thus, FISH could be performed accurately with very small numbers of tumor cells from touch preparations of needle biopsies. Moreover, this procedure allowed us to discern the heterogeneous pattern of MYCN amplification that is characteristic of neuroblastoma. We conclude that FISH improves the detection of MYCN gene amplification in childhood neuroblastomas in a clinical setting, thus facilitating therapeutic decisions based on the presence or absence of this prognostically important biologic marker.

  15. Local amplification of seismic waves from the Denali earthquake and damaging seiches in Lake Union, Seattle, Washington

    Science.gov (United States)

    Barberopoulou, A.; Qamar, A.; Pratt, T.L.; Creager, K.C.; Steele, W.P.

    2004-01-01

    The Mw7.9 Denali, Alaska earthquake of 3 November, 2002, caused minor damage to at least 20 houseboats in Seattle, Washington by initiating water waves in Lake Union. These water waves were likely initiated during the large amplitude seismic surface waves from this earthquake. Maps of spectral amplification recorded during the Denali earthquake on the Pacific Northwest Seismic Network (PNSN) strong-motion instruments show substantially increased shear and surface wave amplitudes coincident with the Seattle sedimentary basin. Because Lake Union is situated on the Seattle basin, the size of the water waves may have been increased by local amplification of the seismic waves by the basin. Complete hazard assessments require understanding the causes of these water waves during future earthquakes. Copyright 2004 by the American Geophysical Union.

  16. [Individual Identification of Cartilage by Direct Amplification in Mass Disasters].

    Science.gov (United States)

    Wang, C H; Xu, C; Li, X Q; Wu, Y; Du, Z

    2017-06-01

    To explore the effectiveness of direct amplification for the STR analysis of cartilage, and to accelerate the effectiveness of disaster victim identification. Eighty-eight cartilage samples were directly amplified by PowerPle® 21 kit, and the results of genotyping were compared with that obtained by the magnetic beads method. In 88 cartilage samples, the STR genotypes were successfully detected from 84 samples by direct amplification and magnetic beads method, and both the results of genotyping by two method were consistent. Direct amplification with PowerPlex® 21 kit can be used for STR genotyping of cartilages. This method is operated easily and promptly, which has a potential application in the individual identification of mass disasters. Copyright© by the Editorial Department of Journal of Forensic Medicine

  17. Multi-chamber nucleic acid amplification and detection device

    Science.gov (United States)

    Dugan, Lawrence

    2017-10-25

    A nucleic acid amplification and detection device includes an amplification cartridge with a plurality of reaction chambers for containing an amplification reagent and a visual detection reagent, and a plurality of optically transparent view ports for viewing inside the reaction chambers. The cartridge also includes a sample receiving port which is adapted to receive a fluid sample and fluidically connected to distribute the fluid sample to the reaction chamber, and in one embodiment, a plunger is carried by the cartridge for occluding fluidic communication to the reaction chambers. The device also includes a heating apparatus having a heating element which is activated by controller to generate heat when a trigger event is detected. The heating apparatus includes a cartridge-mounting section which positioned a cartridge in thermal communication with the heating element so that visual changes to the contents of the reaction chambers are viewable through the view ports.

  18. Radioactive wastes and the social amplification of risk

    International Nuclear Information System (INIS)

    Kasperson, R.E.; Emel, J.; Goble, R.; Hohenemser, C.; Kasperson, J.X.; Renn, O.

    1987-01-01

    A significant problem in radioactive waste facility siting is that apparent small risks or minor risks events produce substantial public concern and social impacts. The reasons for this difference in public health and societal impacts is not well understood. This paper explores the issues involved in the social amplification of risk, using the risk associated with site characterization as the example. Noteworthy as sources of amplification are the information flow associated with risks and risk events including the large volume of information, the extent of dispute, and misinformation and rumor. Such information passes through the mass media and interpersonal networks. The major mechanisms involved in risk amplifications are discussed and their likely impacts on society described

  19. Germline PRKACA amplification leads to Cushing syndrome caused by 3 adrenocortical pathologic phenotypes.

    Science.gov (United States)

    Carney, J Aidan; Lyssikatos, Charalampos; Lodish, Maya B; Stratakis, Constantine A

    2015-01-01

    We describe the pathology of 5 patients with germline PRKACA copy number gain and Cushing syndrome: 4 males and 1 female, aged 2 to 43 years, including a mother and son. Imaging showed normal or slightly enlarged adrenal glands in 4 patients and a unilateral mass in the fifth. Biochemically, the patients had corticotropin-independent hypercortisolism. Four underwent bilateral adrenalectomy; unilateral adrenalectomy was performed in the patient with the adrenal mass. Pathologically, 3 patients, including the 1 with the tumor (adenoma), had primary pigmented nodular adrenocortical disease with extranodular cortical atrophy and mild intracapsular and extracapsular extension of cortical cells. The other 2 patients had cortical hyperplasia and prominent capsular and extracapsular micronodular cortical hyperplasia. Immunoperoxidase staining revealed differences for synaptophysin, inhibin-A, and Ki-67 (nuclei) in the atrophic cortices (patients 1, 2, and 3) and hyperplastic cortices (patients 4 and 5) and for Ki-67 (nuclei) and vimentin in the extracortical nodules in the 2 groups of patients. β-Catenin stained the cell membrane, cytoplasm, and nuclei of the adenoma. The patients were well at follow-up (1-23 years); 24-hour urinary cortisol excretion was elevated in the patient who had unilateral adrenalectomy. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Methods for microbial DNA extraction from soil for PCR amplification

    Directory of Open Access Journals (Sweden)

    Yeates C

    1998-01-01

    Full Text Available Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1. DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation. This method was compared to other DNA extraction methods with regard to DNA purity and size.

  1. Weak value amplification via second-order correlated technique

    International Nuclear Information System (INIS)

    Cui Ting; Huang Jing-Zheng; Zeng Gui-Hua; Liu Xiang

    2016-01-01

    We propose a new framework combining weak measurement and second-order correlated technique. The theoretical analysis shows that weak value amplification (WVA) experiment can also be implemented by a second-order correlated system. We then build two-dimensional second-order correlated function patterns for achieving higher amplification factor and discuss the signal-to-noise ratio influence. Several advantages can be obtained by our proposal. For instance, detectors with high resolution are not necessary. Moreover, detectors with low saturation intensity are available in WVA setup. Finally, type-one technical noise can be effectively suppressed. (paper)

  2. Amplification-free liquid biopsy by fluorescence approach

    DEFF Research Database (Denmark)

    Uhd, Jesper; Okholm, Anders; Kjems, Jargen

    2017-01-01

    Liquid biopsy is an attractive new paradigm of modern cancer research and clinical oncology. Synergy of fluorescence microscopy with mutation specific molecular probes is a method that we developed for the detection of tumor related circulating DNA, ctDNA. The present detection methods of ctDNA...... samples include amplification-based techniques that have multiple challenges, are often time consuming and rather expensive. In this work, we successfully applied the hybridization assay and advanced microscopy for the reliable amplification-free detection and quantification of cancer associated mutations...... in ctDNA....

  3. [Prognostic significance of MYCN amplification in children neuroblastic tumors].

    Science.gov (United States)

    Niu, Huilin; Xu, Tao; Wang, Fenghua; Chen, Zhengrong; Gao, Qiu; Yi, Peng; Xia, Jianqing

    2015-02-01

    To summarize the clinicopathologic features of neuroblastic tumors (NT), and to explore the prognostic significance of MYCN amplification in NT. The clinicopathologic data of 267 NT were reviewed. MYCN gene amplification was detected by fluorescence in situ hybridization (FISH) in 119 cases and the relationship with pathological characteristics and prognostic significance were analyzed. The study included 267 cases of children NT from patients aged from 1 day to 13 years (median 27 months). The male to female ratio was 1.43. There were 38 cases (14.2%), 43 cases (16.1%), 71 cases (26.6%), and 115 cases (43.1%) of INSS stages I, II, III and IV respectively.Favorable histology group had 157 cases (59.9%); unfavorable histology group had 110 cases (40.1%).Of the 119 NT cases with MYCN FISH performed, 18 cases (15.1%) showed amplification and the signal ratio of MYCN to CEP2 was 4.08-43.29. One hundred and one cases of non-amplified MYCN included MYCN gain in 79 cases (66.3%) and MYCN negative in 22 cases (18.5%). MYCN expression showed significant difference (P = 0.000) between ages, gender, NT type and MKI, but not INPC and clinical stage (P > 0.05).Of the 18 cases with MYCN amplification, 3 were undifferentiated, and 15 poorly differentiated; 17 had high MKI and one moderate MKI. All 18 cases were in unfavorable histology group; the overall survival rate was 3/18, with an average survival time of (17.9 ± 2.4) months.Of the 101 MYCN non-amplification cases, the overall survival rate was 68.3% (69/101), with an average survival time of (29.8 ± 1.3) months. Survival analysis showed the cases with MYCN amplification had worse prognosis (P < 0.05). NT were commonly diagnosed in early ages and easily to metastasize. Most of cases with favorable histology. The cases of MYCN amplification showed unfavorable histology, and the majority cases with high MKI; The patients with MYCN gene amplification had poor prognosis.

  4. Unintended Pregnancy, Induced Abortion, and Mental Health.

    Science.gov (United States)

    Horvath, Sarah; Schreiber, Courtney A

    2017-09-14

    The early medical literature on mental health outcomes following abortion is fraught with methodological flaws that can improperly influence clinical practice. Our goal is to review the current medical literature on depression and other mental health outcomes for women obtaining abortions. The Turnaway Study prospectively enrolled 956 women seeking abortion in the USA and followed their mental health outcomes for 5 years. The control group was comprised of women denied abortions based on gestational age limits, thereby circumventing the major methodological flaw that had plagued earlier studies on the topic. Rates of depression are not significantly different between women obtaining abortion and those denied abortion. Rates of anxiety are initially higher in women denied abortion care. Counseling on decision-making for women with unintended pregnancies should reflect these findings.

  5. Simultaneous Aurora-A/STK15 overexpression and centrosome amplification induce chromosomal instability in tumour cells with a MIN phenotype

    Directory of Open Access Journals (Sweden)

    Schillaci Tiziana

    2007-11-01

    Full Text Available Abstract Background Genetic instability is a hallmark of tumours and preneoplastic lesions. The predominant form of genome instability in human cancer is chromosome instability (CIN. CIN is characterized by chromosomal aberrations, gains or losses of whole chromosomes (aneuploidy, and it is often associated with centrosome amplification. Centrosomes control cell division by forming a bipolar mitotic spindle and play an essential role in the maintenance of chromosomal stability. However, whether centrosome amplification could directly cause aneuploidy is not fully established. Also, alterations in genes required for mitotic progression could be involved in CIN. A major candidate is represented by Aurora-A/STK15 that associates with centrosomes and is overexpressed in several types of human tumour. Methods Centrosome amplification were induced by hydroxyurea treatment and visualized by immunofluorescence microscopy. Aurora-A/STK15 ectopic expression was achieved by retroviral infection and puromycin selection in HCT116 tumour cells. Effects of Aurora-A/STK15 depletion on centrosome status and ploidy were determined by Aurora-A/STK15 transcriptional silencing by RNA interference. Changes in the expression levels of some mitotic genes were determined by Real time RT-PCR. Results We investigated whether amplification of centrosomes and overexpression of Aurora-A/STK15 induce CIN using as a model system a colon carcinoma cell line (HCT116. We found that in HCT116 cells, chromosomally stable and near diploid cells harbouring a MIN phenotype, centrosome amplification induced by hydroxyurea treatment is neither maintained nor induces aneuploidy. On the contrary, ectopic overexpression of Aurora-A/STK15 induced supernumerary centrosomes and aneuploidy. Aurora-A/STK15 transcriptional silencing by RNA interference in cells ectopically overexpressing this kinase promptly decreased cell numbers with supernumerary centrosomes and aneuploidy. Conclusion Our

  6. Highly efficient amplification of chronic wasting disease agent by protein misfolding cyclical amplification with beads (PMCAb)

    Science.gov (United States)

    Johnson, Chad J.; Aiken, Judd M.; McKenzie, Debbie; Samuel, Michael D.; Pedersen, Joel A.

    2012-01-01

    Protein misfolding cyclic amplification (PMCA) has emerged as an important technique for detecting low levels of pathogenic prion protein in biological samples. The method exploits the ability of the pathogenic prion protein to convert the normal prion protein to a proteinase K-resistant conformation. Inclusion of Teflon® beads in the PMCA reaction (PMCAb) has been previously shown to increase the sensitivity and robustness of detection for the 263 K and SSLOW strains of hamster-adapted prions. Here, we demonstrate that PMCAb with saponin dramatically increases the sensitivity of detection for chronic wasting disease (CWD) agent without compromising the specificity of the assay (i.e., no false positive results). Addition of Teflon® beads increased the robustness of the PMCA reaction, resulting in a decrease in the variability of PMCA results. Three rounds of serial PMCAb allowed detection of CWD agent from a 6.7×10−13 dilution of 10% brain homogenate (1.3 fg of source brain). Titration of the same brain homogenate in transgenic mice expressing cervid prion protein (Tg(CerPrP)1536+/−mice) allowed detection of CWD agent from the 10−6 dilution of 10% brain homogenate. PMCAb is, thus, more sensitive than bioassay in transgenic mice by a factor exceeding 105. Additionally, we are able to amplify CWD agent from brain tissue and lymph nodes of CWD-positive white-tailed deer having Prnp alleles associated with reduced disease susceptibility.

  7. Highly efficient amplification of chronic wasting disease agent by protein misfolding cyclic amplification with beads (PMCAb.

    Directory of Open Access Journals (Sweden)

    Chad J Johnson

    Full Text Available Protein misfolding cyclic amplification (PMCA has emerged as an important technique for detecting low levels of pathogenic prion protein in biological samples. The method exploits the ability of the pathogenic prion protein to convert the normal prion protein to a proteinase K-resistant conformation. Inclusion of Teflon® beads in the PMCA reaction (PMCAb has been previously shown to increase the sensitivity and robustness of detection for the 263 K and SSLOW strains of hamster-adapted prions. Here, we demonstrate that PMCAb with saponin dramatically increases the sensitivity of detection for chronic wasting disease (CWD agent without compromising the specificity of the assay (i.e., no false positive results. Addition of Teflon® beads increased the robustness of the PMCA reaction, resulting in a decrease in the variability of PMCA results. Three rounds of serial PMCAb allowed detection of CWD agent from a 6.7 × 10(-13 dilution of 10% brain homogenate (1.3 fg of source brain. Titration of the same brain homogenate in transgenic mice expressing cervid prion protein (Tg(CerPrP1536(+/- mice allowed detection of CWD agent from the 10(-6 dilution of 10% brain homogenate. PMCAb is, thus, more sensitive than bioassay in transgenic mice by a factor exceeding 10(5. Additionally, we are able to amplify CWD agent from brain tissue and lymph nodes of CWD-positive white-tailed deer having Prnp alleles associated with reduced disease susceptibility.

  8. Classification of human cancers based on DNA copy number amplification modeling

    Directory of Open Access Journals (Sweden)

    Knuutila Sakari

    2008-05-01

    Full Text Available Abstract Background DNA amplifications alter gene dosage in cancer genomes by multiplying the gene copy number. Amplifications are quintessential in a considerable number of advanced cancers of various anatomical locations. The aims of this study were to classify human cancers based on their amplification patterns, explore the biological and clinical fundamentals behind their amplification-pattern based classification, and understand the characteristics in human genomic architecture that associate with amplification mechanisms. Methods We applied a machine learning approach to model DNA copy number amplifications using a data set of binary amplification records at chromosome sub-band resolution from 4400 cases that represent 82 cancer types. Amplification data was fused with background data: clinical, histological and biological classifications, and cytogenetic annotations. Statistical hypothesis testing was used to mine associations between the data sets. Results Probabilistic clustering of each chromosome identified 111 amplification models and divided the cancer cases into clusters. The distribution of classification terms in the amplification-model based clustering of cancer cases revealed cancer classes that were associated with specific DNA copy number amplification models. Amplification patterns – finite or bounded descriptions of the ranges of the amplifications in the chromosome – were extracted from the clustered data and expressed according to the original cytogenetic nomenclature. This was achieved by maximal frequent itemset mining using the cluster-specific data sets. The boundaries of amplification patterns were shown to be enriched with fragile sites, telomeres, centromeres, and light chromosome bands. Conclusions Our results demonstrate that amplifications are non-random chromosomal changes and specifically selected in tumor tissue microenvironment. Furthermore, statistical evidence showed that specific chromosomal features

  9. Amplification and Attenuation across USArray using Ambient Noise Wavefront Tracking

    KAUST Repository

    Bowden, Daniel C.

    2017-11-15

    As seismic travel-time tomography continues to be refined using data from the vast USArray dataset, it is advantageous to also exploit the amplitude information carried by seismic waves. We use ambient noise cross correlation to make observations of surface-wave amplification and attenuation at shorter periods (8 – 32 seconds) than can be observed with only traditional teleseismic earthquake sources. We show that the wavefront tracking approach of [Lin et al., 2012a] can be successfully applied to ambient noise correlations, yielding results quite similar to those from earthquake observations at periods of overlap. This consistency indicates that the wavefront tracking approach is viable for use with ambient noise correlations, despite concerns of the inhomogeneous and unknown distribution of noise sources. The resulting amplification and attenuation maps correlate well with known tectonic and crustal structure; at the shortest periods, our amplification and attenuation maps correlate well with surface geology and known sedimentary basins, while our longest period amplitudes are controlled by crustal thickness and begin to probe upper mantle materials. These amplification and attenuation observations are sensitive to crustal materials in different ways than travel-time observations and may be used to better constrain temperature or density variations. We also value them as an independent means of describing the lateral variability of observed Rayleigh-wave amplitudes without the need for 3D tomographic inversions.

  10. Single primer amplification reaction methods reveal exotic and ...

    Indian Academy of Sciences (India)

    Unknown

    mulberry varieties using three different PCR based single primer amplification ..... the results of a multi- variate analysis using Mahalanobis D2 statistic in case of .... Rajan M V, Chaturvedi H K and Sarkar A 1997 Multivariate analysis as an aid ...

  11. Nucleic Acid Amplification as used in the Diagnosis and ...

    African Journals Online (AJOL)

    Nucleic Acid Amplification as used in the Diagnosis and Management of Viral Diseases: A Review. ... Bayero Journal of Pure and Applied Sciences ... are highly unculturable, fastidious or hazardous to the laboratory personnel and diagnosis depends on serological methods or culture in an expensive bio-safety level.

  12. Four-quadrant flyback converter for direct audio power amplification

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a bidirectional, four-quadrant flyback converter for use in direct audio power amplification. When compared to the standard Class-D switching audio power amplifier with a separate power supply, the proposed four-quadrant flyback converter provides simple solution with better...

  13. Four-quadrant flyback converter for direct audio power amplification

    OpenAIRE

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a bidirectional, four-quadrant flyback converter for use in direct audio power amplification. When compared to the standard Class-D switching audio power amplifier with a separate power supply, the proposed four-quadrant flyback converter provides simple solution with better efficiency, higher level of integration and lower component count.

  14. Loop-mediated isothermal amplification (LAMP) based detection of ...

    African Journals Online (AJOL)

    SAM

    2014-05-07

    May 7, 2014 ... 2 months for growing in a culture. Therefore, to control .... The LAMP reaction is carried out in a 25 µL reaction mixture containing ..... J. Fish Dis. 32(6):491-497. Goto M, Honda E, Ogura A, Nomoto A, Hanaki K (2009). Colorimetric detection of loop-mediated isothermal amplification reaction by using hydroxy ...

  15. Whole genome amplification: Use of advanced isothermal method

    African Journals Online (AJOL)

    Yomi

    2010-12-29

    Dec 29, 2010 ... 1Ph.D. Student, Department of Animal Science, Science and Research Branch, Islamic Azad University(IAU), ... sequence has a large effect on both the denaturation of ..... performance of multiple displacement amplification and OmniPlex ... Dean FB, Hosono S, Fang L, Wu L, Faruqi AF, Bray-Ward P, Sun Z,.

  16. Controlling the amplification of chirality in hydrogen-bonded assemblies

    NARCIS (Netherlands)

    Mateos timoneda, Miguel; Crego Calama, Mercedes; Reinhoudt, David

    2005-01-01

    The amplification of chirality (a high enantiomeric or diastereomeric excess induced by a small initial amount of chiral bias) on hydrogen-bonded assemblies has been studied using “sergeants-and-soldiers” experiments under thermodynamically controlled conditions. Here it is shown that different

  17. Particle creation amplification in curved space due to thermal effects

    International Nuclear Information System (INIS)

    Laciana, C. E.

    1997-01-01

    A physical system composed by a scalar field minimally coupled to gravity and a thermal reservoir as in thermo field dynamics, all of them in curved space-time, is considered. When the formalism of thermo field dynamics is generalized to the above case, an amplification in the number of created particles is predicted

  18. Probabilistic Sensitivity Amplification Control for Lower Extremity Exoskeleton

    Directory of Open Access Journals (Sweden)

    Likun Wang

    2018-03-01

    Full Text Available To achieve ideal force control of a functional autonomous exoskeleton, sensitivity amplification control is widely used in human strength augmentation applications. The original sensitivity amplification control aims to increase the closed-loop control system sensitivity based on positive feedback without any sensors between the pilot and the exoskeleton. Thus, the measurement system can be greatly simplified. Nevertheless, the controller lacks the ability to reject disturbance and has little robustness to the variation of the parameters. Consequently, a relatively precise dynamic model of the exoskeleton system is desired. Moreover, the human-robot interaction (HRI cannot be interpreted merely as a particular part of the driven torque quantitatively. Therefore, a novel control methodology, so-called probabilistic sensitivity amplification control, is presented in this paper. The innovation of the proposed control algorithm is two-fold: distributed hidden-state identification based on sensor observations and evolving learning of sensitivity factors for the purpose of dealing with the variational HRI. Compared to the other state-of-the-art algorithms, we verify the feasibility of the probabilistic sensitivity amplification control with several experiments, i.e., distributed identification model learning and walking with a human subject. The experimental result shows potential application feasibility.

  19. Two-photon stimulated emission and pulse amplification

    International Nuclear Information System (INIS)

    Yuen, H.P.

    1975-01-01

    Threshold conditions are given for the sustained operation of standing-wave and long-pulse traveling-wave two-photon lasers. Pulse shortening in long-pulse two-photon amplification, a behavior absent in the one-photon case, is also demonstrated analytically. (U.S.)

  20. Resonant amplification of quantum fluctuations in a spinor gas

    DEFF Research Database (Denmark)

    Topic, O.; Scherer, M.; Gebreyesus, G.

    2010-01-01

    Bose-Einstein condensates of atoms with non-zero spin are known to constitute an ideal system to investigate fundamental properties of magnetic superfluids. More recently it was realized that they also provide the fascinating opportunity to investigate the macroscopic amplification of quantum...

  1. Differential transimpedance amplifier circuit for correlated differential amplification

    Science.gov (United States)

    Gresham, Christopher A [Albuquerque, NM; Denton, M Bonner [Tucson, AZ; Sperline, Roger P [Tucson, AZ

    2008-07-22

    A differential transimpedance amplifier circuit for correlated differential amplification. The amplifier circuit increase electronic signal-to-noise ratios in charge detection circuits designed for the detection of very small quantities of electrical charge and/or very weak electromagnetic waves. A differential, integrating capacitive transimpedance amplifier integrated circuit comprising capacitor feedback loops performs time-correlated subtraction of noise.

  2. Parametric amplification in a micro Coriolis mass flow sensor

    NARCIS (Netherlands)

    Groenesteijn, Jarno; Droogendijk, H.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; Lötters, Joost Conrad; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2014-01-01

    We report on the application of parametric amplification to a micro Coriolis mass flow sensor. We demonstrate that this mechanism allows for reduction of the system's power dissipation while retaining sensitivity to flow. By reducing this power dissipation, less heat will be transferred to the fluid

  3. Development of an electronic system for signals amplification

    International Nuclear Information System (INIS)

    Santos, Italo S.; Tobias, Carmen C.B.

    2009-01-01

    This paper presents the obtained results with a spectrometer for electromagnetic radiation whose detector, a Si PIN type diode, was directly coupled to a signal amplification system developed in this project for scientific initiation. The linearity conditions and the gain operational limits, constituted of two stages of amplification based on the employment of devices from AMTEK A225 and A206, were determined using a precision pulse generator. The obtained results shown that the developed system is stable and linear in the gain range of 50-150. The spectrometric response of the electronic system coupled to the Siemens SFH-00206 type diode, were studied in view of the register of the 59.5 keV gamma ray spectra proceeding from 241 Am as function of the reversal polarization voltage. The influence pf the voltage and the electronic contribution in the energy resolution of the registered spectra under room temperature (22 degree Celsius) had also investigated considering the more adequate value of the coupling capacitance of the amplification system diode. Up to the present. the best energy resolution (FWHM = 4.85 keV) of the 59.5 keV line was obtained for the condition of the detector polarization at 16 V. This result proves that the signal amplification system developed coupled to the SFH00206 diode, besides the low cost, excellent operational condition for the detection and spectrometry or low energy electromagnetic radiation

  4. Development of loop-mediated isothermal amplification method for ...

    African Journals Online (AJOL)

    A novel assay method to detect the highly virulent Porcine reproductive and respiratory syndrome virus (PRRSV) termed reverse transcriptase loop-mediated isothermal amplification (RT-LAMP), was reported by using hydroxynaphthol blue (HNB) as the LAMP product colorimetric judgment. By the set of special primers, ...

  5. Amplification and Re-Generation of LNA-Modified Libraries

    DEFF Research Database (Denmark)

    Doessing, Holger; Hansen, Lykke H.; Veedu, Rakesh N.

    2012-01-01

    Locked nucleic acids (LNA) confer high thermal stability and nuclease resistance to oligonucleotides. The discovery of polymerases that accept LNA triphosphates has led us to propose a scheme for the amplification and re-generation of LNA-containing oligonucleotide libraries. Such libraries could...

  6. Quality control for quantitative PCR based on amplification compatibility test

    Czech Academy of Sciences Publication Activity Database

    Tichopád, Aleš; Bar, T.; Pecen, Ladislav; Kitchen, R.R.; Kubista, Mikael; Pfaffl, M.W.

    2010-01-01

    Roč. 50, č. 4 (2010), s. 308-312 ISSN 1046-2023 R&D Projects: GA AV ČR IAA500520809; GA AV ČR IAA500970904 Institutional research plan: CEZ:AV0Z50520701 Keywords : Quantitative PCR * Quality control * Amplification efficiency Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.527, year: 2010

  7. Amplification biases: possible differences among deviating gene expressions

    Directory of Open Access Journals (Sweden)

    Piumi Francois

    2008-01-01

    Full Text Available Abstract Background Gene expression profiling has become a tool of choice to study pathological or developmental questions but in most cases the material is scarce and requires sample amplification. Two main procedures have been used: in vitro transcription (IVT and polymerase chain reaction (PCR, the former known as linear and the latter as exponential. Previous reports identified enzymatic pitfalls in PCR and IVT protocols; however the possible differences between the sequences affected by these amplification defaults were only rarely explored. Results Screening a bovine cDNA array dedicated to embryonic stages with embryonic (n = 3 and somatic tissues (n = 2, we proceeded to moderate amplifications starting from 1 μg of total RNA (global PCR or IVT one round. Whatever the tissue, 16% of the probes were involved in deviating gene expressions due to amplification defaults. These distortions were likely due to the molecular features of the affected sequences (position within a gene, GC content, hairpin number but also to the relative abundance of these transcripts within the tissues. These deviating genes mainly encoded housekeeping genes from physiological or cellular processes (70% and constituted 2 subsets which did not overlap (molecular features, signal intensities, gene ID. However, the differential expressions identified between embryonic stages were both reliable (minor intersect with biased expressions and relevant (biologically validated. In addition, the relative expression levels of those genes were biologically similar between amplified and unamplified samples. Conclusion Conversely to the most recent reports which challenged the use of intense amplification procedures on minute amounts of RNA, we chose moderate PCR and IVT amplifications for our gene profiling study. Conclusively, it appeared that systematic biases arose even with moderate amplification procedures, independently of (i the sample used: brain, ovary or embryos, (ii

  8. New perspectives on microbial community distortion after whole-genome amplification

    Science.gov (United States)

    Whole-genome amplification (WGA) has become an important tool to explore the genomic information of microorganisms in an environmental sample with limited biomass, however potential selective biases during the amplification processes are poorly understood. Here, we describe the e...

  9. An evaluation of multiple annealing and looping based genome amplification using a synthetic bacterial community

    KAUST Repository

    Wang, Yong; Gao, Zhaoming; Xu, Ying; Li, Guangyu; He, Lisheng; Qian, Peiyuan

    2016-01-01

    -generation-sequencing technology. Using a synthetic bacterial community, the amplification efficiency of the Multiple Annealing and Looping Based Amplification Cycles (MALBAC) kit that is originally developed to amplify the single-cell genomic DNA of mammalian organisms

  10. MET amplification, expression, and exon 14 mutations in colorectal adenocarcinoma.

    Science.gov (United States)

    Zhang, Meng; Li, Guichao; Sun, Xiangjie; Ni, Shujuan; Tan, Cong; Xu, Midie; Huang, Dan; Ren, Fei; Li, Dawei; Wei, Ping; Du, Xiang

    2018-04-08

    MET amplification, expression, and splice mutations at exon 14 result in dysregulation of the MET signaling pathway. The aim of this study was to identify the relationship between MET amplification, protein or mRNA expression, and mutations in colorectal cancer (CRC). MET immunohistochemistry (IHC) was used for MET protein expression analysis and fluorescence in situ hybridization (FISH) was used for MET amplification detection. Both analyses were performed in tissue microarrays (TMA) containing 294 of colorectal adenocarcinoma tissue samples and 131 samples of adjacent normal epithelial tissue. MET mRNA expression was examined by real-time quantitative polymerase chain reaction (qRT-PCR) in 72 fresh colorectal adenocarcinoma tissue samples and adjacent normal colon tissue. PCR sequencing was performed to screen for MET exon 14 splice mutations in 59 fresh CRC tissue samples. Our results showed that MET protein expression was higher in colorectal tumor tissue than in adjacent normal intestinal epithelium. Positive MET protein expression was associated with significantly poorer overall survival (OS) and disease-free survival (DFS). Multivariate analysis revealed that positive MET protein expression was an independent risk factor for DFS, but not for OS. MET mRNA expression was upregulated in tumor tissues compared with the adjacent normal tissues. The incidence of MET amplification was 4.4%. None of the patients was positive for MET mutation. Collectively, MET was overexpressed in colorectal adenocarcinoma, and its positive protein expression predicted a poorer outcome in CRC patients. Furthermore, according to our results, MET amplification and 14 exon mutation are extremely rare events in colorectal adenocarcinoma. Copyright © 2018. Published by Elsevier Inc.

  11. Voltage-dependent amplification of synaptic inputs in respiratory motoneurones

    Science.gov (United States)

    Enríquez Denton, M; Wienecke, J; Zhang, M; Hultborn, H; Kirkwood, P A

    2012-01-01

    The role of persistent inward currents (PICs) in cat respiratory motoneurones (phrenic inspiratory and thoracic expiratory) was investigated by studying the voltage-dependent amplification of central respiratory drive potentials (CRDPs), recorded intracellularly, with action potentials blocked with the local anaesthetic derivative, QX-314. Decerebrate unanaesthetized or barbiturate-anaesthetized preparations were used. In expiratory motoneurones, plateau potentials were observed in the decerebrates, but not under anaesthesia. For phrenic motoneurones, no plateau potentials were observed in either state (except in one motoneurone after the abolition of the respiratory drive by means of a medullary lesion), but all motoneurones showed voltage-dependent amplification of the CRDPs, over a wide range of membrane potentials, too wide to result mainly from PIC activation. The measurements of the amplification were restricted to the phase of excitation, thus excluding the inhibitory phase. Amplification was found to be greatest for the smallest CRDPs in the lowest resistance motoneurones and was reduced or abolished following intracellular injection of the NMDA channel blocker, MK-801. Plateau potentials were readily evoked in non-phrenic cervical motoneurones in the same (decerebrate) preparations. We conclude that the voltage-dependent amplification of synaptic excitation in phrenic motoneurones is mainly the result of NMDA channel modulation rather than the activation of Ca2+ channel mediated PICs, despite phrenic motoneurones being strongly immunohistochemically labelled for CaV1.3 channels. The differential PIC activation in different motoneurones, all of which are CaV1.3 positive, leads us to postulate that the descending modulation of PICs is more selective than has hitherto been believed. PMID:22495582

  12. Breakdown of hot-spot model in determining convective amplification in large homogeneous systems

    International Nuclear Information System (INIS)

    Mounaix, Philippe; Divol, Laurent

    2004-01-01

    Convective amplification in large homogeneous systems is studied, both analytically and numerically, in the case of a linear diffraction-free stochastic amplifier. Overall amplification does not result from successive amplifications in small scale high intensity hot spots, but from a single amplification in a delocalized mode of the driver field spreading over the whole interaction length. For this model, the hot-spot approach is found to systematically underestimate the gain factor by more than 50%

  13. Origin-Dependent Inverted-Repeat Amplification: Tests of a Model for Inverted DNA Amplification.

    Directory of Open Access Journals (Sweden)

    Bonita J Brewer

    2015-12-01

    Full Text Available DNA replication errors are a major driver of evolution--from single nucleotide polymorphisms to large-scale copy number variations (CNVs. Here we test a specific replication-based model to explain the generation of interstitial, inverted triplications. While no genetic information is lost, the novel inversion junctions and increased copy number of the included sequences create the potential for adaptive phenotypes. The model--Origin-Dependent Inverted-Repeat Amplification (ODIRA-proposes that a replication error at pre-existing short, interrupted, inverted repeats in genomic sequences generates an extrachromosomal, inverted dimeric, autonomously replicating intermediate; subsequent genomic integration of the dimer yields this class of CNV without loss of distal chromosomal sequences. We used a combination of in vitro and in vivo approaches to test the feasibility of the proposed replication error and its downstream consequences on chromosome structure in the yeast Saccharomyces cerevisiae. We show that the proposed replication error-the ligation of leading and lagging nascent strands to create "closed" forks-can occur in vitro at short, interrupted inverted repeats. The removal of molecules with two closed forks results in a hairpin-capped linear duplex that we show replicates in vivo to create an inverted, dimeric plasmid that subsequently integrates into the genome by homologous recombination, creating an inverted triplication. While other models have been proposed to explain inverted triplications and their derivatives, our model can also explain the generation of human, de novo, inverted amplicons that have a 2:1 mixture of sequences from both homologues of a single parent--a feature readily explained by a plasmid intermediate that arises from one homologue and integrates into the other homologue prior to meiosis. Our tests of key features of ODIRA lend support to this mechanism and suggest further avenues of enquiry to unravel the origins

  14. Origin-Dependent Inverted-Repeat Amplification: Tests of a Model for Inverted DNA Amplification.

    Science.gov (United States)

    Brewer, Bonita J; Payen, Celia; Di Rienzi, Sara C; Higgins, Megan M; Ong, Giang; Dunham, Maitreya J; Raghuraman, M K

    2015-12-01

    DNA replication errors are a major driver of evolution--from single nucleotide polymorphisms to large-scale copy number variations (CNVs). Here we test a specific replication-based model to explain the generation of interstitial, inverted triplications. While no genetic information is lost, the novel inversion junctions and increased copy number of the included sequences create the potential for adaptive phenotypes. The model--Origin-Dependent Inverted-Repeat Amplification (ODIRA)-proposes that a replication error at pre-existing short, interrupted, inverted repeats in genomic sequences generates an extrachromosomal, inverted dimeric, autonomously replicating intermediate; subsequent genomic integration of the dimer yields this class of CNV without loss of distal chromosomal sequences. We used a combination of in vitro and in vivo approaches to test the feasibility of the proposed replication error and its downstream consequences on chromosome structure in the yeast Saccharomyces cerevisiae. We show that the proposed replication error-the ligation of leading and lagging nascent strands to create "closed" forks-can occur in vitro at short, interrupted inverted repeats. The removal of molecules with two closed forks results in a hairpin-capped linear duplex that we show replicates in vivo to create an inverted, dimeric plasmid that subsequently integrates into the genome by homologous recombination, creating an inverted triplication. While other models have been proposed to explain inverted triplications and their derivatives, our model can also explain the generation of human, de novo, inverted amplicons that have a 2:1 mixture of sequences from both homologues of a single parent--a feature readily explained by a plasmid intermediate that arises from one homologue and integrates into the other homologue prior to meiosis. Our tests of key features of ODIRA lend support to this mechanism and suggest further avenues of enquiry to unravel the origins of interstitial

  15. Amplification of surface acoustic waves by transverse electric current in piezoelectric semiconductors

    DEFF Research Database (Denmark)

    Gulyaev, Yuri V.

    1974-01-01

    acoustoelectric effect but also lead to amplification of surface acoustic waves by electron drift perpendicular to the surface. For Love waves in a piezoelectric semiconductor film on a highly conducting substrate, the amplification coefficient is found and the conditions necessary for amplification...

  16. Exponential isothermal amplification of nucleic acids and amplified assays for proteins, cells, and enzyme activities.

    Science.gov (United States)

    Reid, Michael S; Le, X Chris; Zhang, Hongquan

    2018-04-27

    Isothermal exponential amplification techniques, such as strand-displacement amplification (SDA), rolling circle amplification (RCA), loop-mediated isothermal amplification (LAMP), nucleic acid sequence-based amplification (NASBA), helicase-dependent amplification (HDA), and recombinase polymerase amplification (RPA), have great potential for on-site, point-of-care, and in-situ assay applications. These amplification techniques eliminate the need for temperature cycling required for polymerase chain reaction (PCR) while achieving comparable amplification yield. We highlight here recent advances in exponential amplification reaction (EXPAR) for the detection of nucleic acids, proteins, enzyme activities, cells, and metal ions. We discuss design strategies, enzyme reactions, detection techniques, and key features. Incorporation of fluorescence, colorimetric, chemiluminescence, Raman, and electrochemical approaches enables highly sensitive detection of a variety of targets. Remaining issues, such as undesirable background amplification resulting from non-specific template interactions, must be addressed to further improve isothermal and exponential amplification techniques. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Added Value of HER-2 Amplification Testing by Multiplex Ligation-Dependent Probe Amplification in Invasive Breast Cancer

    Science.gov (United States)

    Kuijpers, Chantal C. H. J.; Moelans, Cathy B.; van Slooten, Henk-Jan; Horstman, Anja; Hinrichs, John W. J.; Al-Janabi, Shaimaa; van Diest, Paul J.; Jiwa, Mehdi

    2013-01-01

    Background HER-2 is a prognostic and predictive marker, but as yet no technique is perfectly able to identify patients likely to benefit from HER-2 targeted therapies. We aimed to prospectively assess the added value of first-line co-testing by IHC, and multiplex ligation-dependent probe amplification (MLPA) and chromogenic in situ hybridization (CISH). Methods As local validation, HER-2 MLPA and CISH were compared in 99 breast cancers. Next, we reviewed 937 invasive breast cancers, from 4 Dutch pathology laboratories, that were prospectively assessed for HER-2 by IHC and MLPA (and CISH in selected cases). Results The validation study demonstrated 100% concordance between CISH and MLPA, if both methods were assessable and conclusive (81.8% of cases). Significant variation regarding percentages IHC 0/1+ and 2+ cases was observed between the laboratories (pCISH was 98.1% (575/586) (Kappa = 0.94). Of the IHC 3+ cases, 6.7% failed to reveal gene amplification, whereas 0.8% of the IHC 0/1+ cases demonstrated gene amplification. Results remained discordant after retrospective review in 3/11 discordant cases. In the remaining 8 cases the original IHC score was incorrect or adapted after repeated IHC staining. Conclusions MLPA is a low-cost and quantitative high-throughput technique with near perfect concordance with CISH. The use of MLPA in routinely co-testing all breast cancers may reduce HER-2 testing variation between laboratories, may serve as quality control for IHC, will reveal IHC 0/1+ patients with gene amplification, likely responsive to trastuzumab, and identify IHC 3+ cases without gene amplification that may respond less well. PMID:24324739

  18. Added value of HER-2 amplification testing by multiplex ligation-dependent probe amplification in invasive breast cancer.

    Directory of Open Access Journals (Sweden)

    Chantal C H J Kuijpers

    Full Text Available BACKGROUND: HER-2 is a prognostic and predictive marker, but as yet no technique is perfectly able to identify patients likely to benefit from HER-2 targeted therapies. We aimed to prospectively assess the added value of first-line co-testing by IHC, and multiplex ligation-dependent probe amplification (MLPA and chromogenic in situ hybridization (CISH. METHODS: As local validation, HER-2 MLPA and CISH were compared in 99 breast cancers. Next, we reviewed 937 invasive breast cancers, from 4 Dutch pathology laboratories, that were prospectively assessed for HER-2 by IHC and MLPA (and CISH in selected cases. RESULTS: The validation study demonstrated 100% concordance between CISH and MLPA, if both methods were assessable and conclusive (81.8% of cases. Significant variation regarding percentages IHC 0/1+ and 2+ cases was observed between the laboratories (p<0.0001. Overall concordance between IHC and MLPA/CISH was 98.1% (575/586 (Kappa = 0.94. Of the IHC 3+ cases, 6.7% failed to reveal gene amplification, whereas 0.8% of the IHC 0/1+ cases demonstrated gene amplification. Results remained discordant after retrospective review in 3/11 discordant cases. In the remaining 8 cases the original IHC score was incorrect or adapted after repeated IHC staining. CONCLUSIONS: MLPA is a low-cost and quantitative high-throughput technique with near perfect concordance with CISH. The use of MLPA in routinely co-testing all breast cancers may reduce HER-2 testing variation between laboratories, may serve as quality control for IHC, will reveal IHC 0/1+ patients with gene amplification, likely responsive to trastuzumab, and identify IHC 3+ cases without gene amplification that may respond less well.

  19. Lung vasodilatory response to inhaled iloprost in experimental pulmonary hypertension: amplification by different type phosphodiesterase inhibitors

    Directory of Open Access Journals (Sweden)

    Weissmann Norbert

    2005-07-01

    Full Text Available Abstract Inhaled prostanoids and phosphodiesterase (PDE inhibitors have been suggested for treatment of severe pulmonary hypertension. In catheterized rabbits with acute pulmonary hypertension induced by continuous infusion of the stable thromboxane analogue U46619, we asked whether sildenafil (PDE1/5/6 inhibitor, motapizone (PDE3 inhibitor or 8-Methoxymethyl-IBMX (PDE1 inhibitor synergize with inhaled iloprost. Inhalation of iloprost caused a transient pulmonary artery pressure decline, levelling off within per se ineffective dose of each PDE inhibitor (200 μg/kg × min 8-Methoxymethyl-IBMX, 1 μg/kg × min sildenafil, 5 μg/kg × min motapizone with subsequent iloprost nebulization, marked amplification of the prostanoid induced pulmonary vasodilatory response was noted and the area under the curve of PPA reduction was nearly threefold increased with all approaches, as compared to sole iloprost administration. Further amplification was achieved with the combination of inhaled iloprost with sildenafil plus motapizone, but not with sildenafil plus 8MM-IBMX. Systemic hemodynamics and gas exchange were not altered for all combinations. We conclude that co-administration of minute systemic doses of selective PDE inhibitors with inhaled iloprost markedly enhances and prolongs the pulmonary vasodilatory response to inhaled iloprost, with maintenance of pulmonary selectivity and ventilation perfusion matching. The prominent effect of sildenafil may be operative via both PDE1 and PDE5, and is further enhanced by co-application of a PDE3 inhibitor.

  20. Development of a Loop-Mediated Isothermal Amplification Assay for Rapid Detection of BK Virus▿

    Science.gov (United States)

    Bista, Bipin Raj; Ishwad, Chandra; Wadowsky, Robert M.; Manna, Pradip; Randhawa, Parmjeet Singh; Gupta, Gaurav; Adhikari, Meena; Tyagi, Rakhi; Gasper, Gina; Vats, Abhay

    2007-01-01

    Loop-mediated isothermal amplification (LAMP) is a novel method for rapid amplification of DNA. Its advantages include rapidity and minimal equipment requirement. The LAMP assay was developed for BK virus (BKV), which is a leading cause of morbidity in renal transplant recipients. The characteristics of the assay, including its specificity and sensitivity, were evaluated. BKV LAMP was performed using various incubation times with a variety of specimens, including unprocessed urine and plasma samples. A ladder pattern on gel electrophoresis, typical of successful LAMP reactions, was observed specifically only for BKV and not for other viruses. The sensitivity of the assay with 1 h of incubation was 100 copies/tube of a cloned BKV fragment. Additionally, a positive reaction was visually ascertained by a simple color reaction using SYBR green dye. BKV LAMP was also successful for urine and plasma specimens without the need for DNA extraction. Due to its simplicity and specificity, the LAMP assay can potentially be developed for “point of care” screening of BKV. PMID:17314224

  1. Development of a loop-mediated isothermal amplification assay for rapid detection of BK virus.

    Science.gov (United States)

    Bista, Bipin Raj; Ishwad, Chandra; Wadowsky, Robert M; Manna, Pradip; Randhawa, Parmjeet Singh; Gupta, Gaurav; Adhikari, Meena; Tyagi, Rakhi; Gasper, Gina; Vats, Abhay

    2007-05-01

    Loop-mediated isothermal amplification (LAMP) is a novel method for rapid amplification of DNA. Its advantages include rapidity and minimal equipment requirement. The LAMP assay was developed for BK virus (BKV), which is a leading cause of morbidity in renal transplant recipients. The characteristics of the assay, including its specificity and sensitivity, were evaluated. BKV LAMP was performed using various incubation times with a variety of specimens, including unprocessed urine and plasma samples. A ladder pattern on gel electrophoresis, typical of successful LAMP reactions, was observed specifically only for BKV and not for other viruses. The sensitivity of the assay with 1 h of incubation was 100 copies/tube of a cloned BKV fragment. Additionally, a positive reaction was visually ascertained by a simple color reaction using SYBR green dye. BKV LAMP was also successful for urine and plasma specimens without the need for DNA extraction. Due to its simplicity and specificity, the LAMP assay can potentially be developed for "point of care" screening of BKV.

  2. Detection of Yersinia enterocolitica in milk powders by cross-priming amplification combined with immunoblotting analysis.

    Science.gov (United States)

    Zhang, Hongwei; Feng, Shaolong; Zhao, Yulong; Wang, Shuo; Lu, Xiaonan

    2015-12-02

    Yersinia enterocolitica (Y. enterocolitica) is frequently isolated from a wide variety of foods and can cause human yersiniosis. Biochemical and culture-based assays are common detection methods, but require a long incubation time and easily misidentify Y. enterocolitica as other non-pathogenic Yersinia species. Alternatively, cross-priming amplification (CPA) under isothermal conditions combined with immunoblotting analysis enables a more sensitive detection in a relatively short time period. A set of specific displacement primers, cross primers and testing primers was designed on the basis of six specific sequences in Y. enterocolitica 16S-23S rDNA internal transcribed spacer. Under isothermal condition, amplification and hybridization were conducted simultaneously at 63°C for 60 min. The specificity of CPA was tested for 96 different bacterial strains and 165 commercial milk powder samples. Two red lines were developed on BioHelix Express strip for all of the Y. enterocolitica strains, and one red line was shown for non-Y. enterocolitica strains. The limit of detection of CPA was 10(0)fg for genomic DNA (1000 times more sensitive than PCR assay), 10(1) CFU/ml for pure bacterial culture, and 10(0) CFU per 100 g milk powder with pre-enrichment at 37°C for 24 h. CPA combined with immunoblotting analysis can achieve highly specific and sensitive detection of Y. enterocolitica in milk powder in 90 min after pre-enrichment. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Improved multiple displacement amplification (iMDA) and ultraclean reagents.

    Science.gov (United States)

    Motley, S Timothy; Picuri, John M; Crowder, Chris D; Minich, Jeremiah J; Hofstadler, Steven A; Eshoo, Mark W

    2014-06-06

    Next-generation sequencing sample preparation requires nanogram to microgram quantities of DNA; however, many relevant samples are comprised of only a few cells. Genomic analysis of these samples requires a whole genome amplification method that is unbiased and free of exogenous DNA contamination. To address these challenges we have developed protocols for the production of DNA-free consumables including reagents and have improved upon multiple displacement amplification (iMDA). A specialized ethylene oxide treatment was developed that renders free DNA and DNA present within Gram positive bacterial cells undetectable by qPCR. To reduce DNA contamination in amplification reagents, a combination of ion exchange chromatography, filtration, and lot testing protocols were developed. Our multiple displacement amplification protocol employs a second strand-displacing DNA polymerase, improved buffers, improved reaction conditions and DNA free reagents. The iMDA protocol, when used in combination with DNA-free laboratory consumables and reagents, significantly improved efficiency and accuracy of amplification and sequencing of specimens with moderate to low levels of DNA. The sensitivity and specificity of sequencing of amplified DNA prepared using iMDA was compared to that of DNA obtained with two commercial whole genome amplification kits using 10 fg (~1-2 bacterial cells worth) of bacterial genomic DNA as a template. Analysis showed >99% of the iMDA reads mapped to the template organism whereas only 0.02% of the reads from the commercial kits mapped to the template. To assess the ability of iMDA to achieve balanced genomic coverage, a non-stochastic amount of bacterial genomic DNA (1 pg) was amplified and sequenced, and data obtained were compared to sequencing data obtained directly from genomic DNA. The iMDA DNA and genomic DNA sequencing had comparable coverage 99.98% of the reference genome at ≥1X coverage and 99.9% at ≥5X coverage while maintaining both balance

  4. Influence of low dose ionizing radiation on amplification and antitumor activity of LAK/TIL cells

    International Nuclear Information System (INIS)

    Liu Wei; Hou Dianjun; Qiao Jianwei; Shang Ximei; Li Jieqing

    2000-01-01

    Objective: To study the influence of low dose ionization on amplification and antitumor activity of LAK/TIL cells. Methods: TIL cells isolated from Lewis lung cancer tissues and LAK cells from spleen of tumor-bearing mouse were irradiated with different low doses of X-rays and were cultured after irradiation. Results: Low dose ionizing radiation improved the amplification volume of LAK/TIL cells, decreased the cell death ratio in amplification process, and increased the toxicity of LAK/TIL cells, Conclusions: Low dose ionizing radiation can result in amplification of biologically activated lymphocytes, and decreases the death ratio of the cells in amplification process

  5. Spin noise amplification and giant noise in optical microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, I. I.; Poltavtsev, S. V.; Kozlov, G. G.; Zapasskii, V. S. [Spin-Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Kavokin, A. V. [Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Spin-Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Lagoudakis, P. V. [Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2015-06-14

    When studying the spin-noise-induced fluctuations of Kerr rotation in a quantum-well microcavity, we have found a dramatic increase of the noise signal (by more than two orders of magnitude) in the vicinity of anti-crossing of the polariton branches. The effect is explained by nonlinear optical instability of the microcavity giving rise to the light-power-controlled amplification of the polarization noise signal. In the framework of the developed model of built-in amplifier, we also interpret the nontrivial spectral and intensity-related properties of the observed noise signal below the region of anti-crossing of polariton branches. The discovered effect of optically controllable amplification of broadband polarization signals in microcavities in the regime of optical instability may be of interest for detecting weak oscillations of optical anisotropy in fundamental research and for other applications in optical information processing.

  6. Whole genome amplification - Review of applications and advances

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, Trevor L.; Detter, J.C.; Richardson, Paul

    2001-11-15

    The concept of Whole Genome Amplification is something that has arisen in the past few years as modifications to the polymerase chain reaction (PCR) have been adapted to replicate regions of genomes which are of biological interest. The applications here are many--forensics, embryonic disease diagnosis, bio terrorism genome detection, ''imoralization'' of clinical samples, microbial diversity, and genotyping. The key question is if DNA can be replicated a genome at a time without bias or non random distribution of the target. Several papers published in the last year and currently in preparation may lead to the conclusion that whole genome amplification may indeed be possible and therefore open up a new avenue to molecular biology.

  7. Surface plasmon polariton amplification in semiconductor-graphene-dielectric structure

    Energy Technology Data Exchange (ETDEWEB)

    Dadoenkova, Yuliya S. [Ulyanovsk State University, Ulyanovsk (Russian Federation); Novgorod State University, Veliky Novgorod (Russian Federation); Donetsk Institute for Physics and Technology, Donetsk (Ukraine); Moiseev, Sergey G. [Ulyanovsk State University, Ulyanovsk (Russian Federation); Kotelnikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Ulyanovsk (Russian Federation); Abramov, Aleksei S. [Ulyanovsk State University, Ulyanovsk (Russian Federation); Kadochkin, Aleksei S.; Zolotovskii, Igor O. [Ulyanovsk State University, Ulyanovsk (Russian Federation); Institute of Nanotechnologies of Microelectronics of the Russian Academy of Sciences, 32A Leninskiy Prosp., 119991, Moscow (Russian Federation); Fotiadi, Andrei A. [Ulyanovsk State University, Ulyanovsk (Russian Federation); Universite de Mons (Belgium)

    2017-05-15

    A mechanism of amplification of surface plasmon polaritons due to the transfer of electromagnetic energy from a drift current wave into a far-infrared surface wave propagating along a semiconductor-dielectric boundary in waveguide geometry is proposed. A necessary condition of the interaction of these waves is phase matching condition, i. e., when the phase velocity of the surface wave approaches the drift velocity of charge carriers. It is shown that in the spectral region of the surface plasmon polariton slowing-down its amplification coefficient can reach values substantially exceeding the ohmic loss coefficient of the surface wave in the structure. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Microfluidic "Pouch" Chips for Immunoassays and Nucleic Acid Amplification Tests.

    Science.gov (United States)

    Mauk, Michael G; Liu, Changchun; Qiu, Xianbo; Chen, Dafeng; Song, Jinzhao; Bau, Haim H

    2017-01-01

    Microfluidic cassettes ("chips") for processing and analysis of clinical specimens and other sample types facilitate point-of-care (POC) immunoassays and nucleic acid based amplification tests. These single-use test chips can be self-contained and made amenable to autonomous operation-reducing or eliminating supporting instrumentation-by incorporating laminated, pliable "pouch" and membrane structures for fluid storage, pumping, mixing, and flow control. Materials and methods for integrating flexible pouch compartments and diaphragm valves into hard plastic (e.g., acrylic and polycarbonate) microfluidic "chips" for reagent storage, fluid actuation, and flow control are described. We review several versions of these pouch chips for immunoassay and nucleic acid amplification tests, and describe related fabrication techniques. These protocols thus offer a "toolbox" of methods for storage, pumping, and flow control functions in microfluidic devices.

  9. Circulation and Directional Amplification in the Josephson Parametric Converter

    Science.gov (United States)

    Hatridge, Michael

    Nonreciprocal transport and directional amplification of weak microwave signals are fundamental ingredients in performing efficient measurements of quantum states of flying microwave light. This challenge has been partly met, as quantum-limited amplification is now regularly achieved with parametrically-driven, Josephson-junction based superconducting circuits. However, these devices are typically non-directional, requiring external circulators to separate incoming and outgoing signals. Recently this limitation has been overcome by several proposals and experimental realizations of both directional amplifiers and circulators based on interference between several parametric processes in a single device. This new class of multi-parametrically driven devices holds the promise of achieving a variety of desirable characteristics simultaneously- directionality, reduced gain-bandwidth constraints and quantum-limited added noise, and are good candidates for on-chip integration with other superconducting circuits such as qubits.

  10. Quantum Privacy Amplification for a Sequence of Single Qubits

    International Nuclear Information System (INIS)

    Deng Fuguo; Long Guilu

    2006-01-01

    We present a scheme for quantum privacy amplification (QPA) for a sequence of single qubits. The QPA procedure uses a unitary operation with two controlled-not gates and a Hadamard gate. Every two qubits are performed with the unitary gate operation, and a measurement is made on one photon and the other one is retained. The retained qubit carries the state information of the discarded one. In this way, the information leakage is reduced. The procedure can be performed repeatedly so that the information leakage is reduced to any arbitrarily low level. With this QPA scheme, the quantum secure direct communication with single qubits can be implemented with arbitrarily high security. We also exploit this scheme to do privacy amplification on the single qubits in quantum information sharing for long-distance communication with quantum repeaters.

  11. Nondeterministic noiseless amplification via non-symplectic phase space transformations

    International Nuclear Information System (INIS)

    Walk, Nathan; Lund, Austin P; Ralph, Timothy C

    2013-01-01

    We analyse the action of an ideal noiseless linear amplifier operator, g a-hat † a-hat, using the Wigner function phase space representation. In this setting we are able to clarify the gain g for which a physical output is produced when this operator is acted upon inputs other than coherent states. We derive compact closed form expressions for the action of N local amplifiers, with potentially different gains, on arbitrary N-mode Gaussian states and provide several examples of the utility of this formalism for determining important quantities including amplification and the strength and purity of the distilled entanglement, and for optimizing the use of the amplification in quantum information protocols. (paper)

  12. Search for methylation-sensitive amplification polymorphisms in mutant figs

    OpenAIRE

    Rodrigues, M. G F; Martins, A. B G [UNESP; Bertoni, B. W.; Figueira, A.; Giuliatti, S.

    2013-01-01

    Fig (Ficus carica) breeding programs that use conventional approaches to develop new cultivars are rare, owing to limited genetic variability and the difficulty in obtaining plants via gamete fusion. Cytosine methylation in plants leads to gene repression, thereby affecting transcription without changing the DNA sequence. Previous studies using random amplification of polymorphic DNA and amplified fragment length polymorphism markers revealed no polymorphisms among select fig mutants that ori...

  13. MYC Amplification in Angiosarcoma Arising from an Arteriovenous Graft Site

    Directory of Open Access Journals (Sweden)

    Kristen M. Paral

    2015-01-01

    Full Text Available Angiosarcoma arising in association with an arteriovenous graft (AVG or fistula is a unique clinicopathologic scenario that appears to be gaining recognition in the literature. Among reported cases, none has described high-level MYC gene amplification, a genetic aberration that is increasingly unifying the various clinicopathologic subdivisions of angiosarcoma. We therefore report the MYC gene status in a case of angiosarcoma arising at an AVG site.

  14. Hyper dispersion pulse compressor for chirped pulse amplification systems

    Science.gov (United States)

    Barty, Christopher P. J.

    2011-11-29

    A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

  15. Research on amplification multiple of source neutron number for ADS

    International Nuclear Information System (INIS)

    Liu Guisheng; Zhao Zhixiang; Zhang Baocheng; Shen Qingbiao; Ding Dazhao

    1998-01-01

    NJOY-91.91 and MILER code systems was applied to process and generate 44 group cross sections in AMPX master library format from CENDL-2 and ENDF/B-6. It is important an ADS (Accelerator-Driven System) assembly spectrum is used as the weighting spectrum for generating multi-group constants. Amplification multiples of source neutron number for several fast assemblies were calculated

  16. Mismatch characteristics of optical parametric chirped pulse amplification

    Czech Academy of Sciences Publication Activity Database

    Novák, Ondřej; Turčičová, Hana; Divoký, Martin; Huynh, Jaroslav; Straka, Petr

    2014-01-01

    Roč. 11, č. 2 (2014), 1-7 ISSN 1612-2011 R&D Projects: GA ČR GA202/06/0814; GA MŠk(CZ) LC528 Institutional support: RVO:68378271 Keywords : phase matching * phase mismatch * beam mismatch * broadband amplification * parametric amplifiers * OPCPA * iodine laser Subject RIV: BH - Optics , Masers, Lasers Impact factor: 2.458, year: 2014

  17. Soft x-ray amplification in an ablative capillary discharge

    International Nuclear Information System (INIS)

    Kwek, K.H.; Low, K.S.; Tan, C.A.; Lim, C.S.

    1999-01-01

    Soft x-ray amplification in CVI 18.2 nm line is observed in an ablative UHMW-PE capillary discharge. The gain coefficient is measured to be 1.9 cm -1 . The electron density is about 2 x 10 19 cm -3 . This indicates that capillary discharge pumping device can be a source for a compact soft x-ray laser. (author)

  18. Field and current amplification in the SSPX spheromak

    International Nuclear Information System (INIS)

    Hill, D.N. . hilld@llnl.gov; Bulmer, R.H.; Cohen, B.I.

    2003-01-01

    Results are presented from experiments relating to magnetic field generation and current amplification in the SSPX spheromak. The SSPX spheromak plasma is driven by DC coaxial helicity injection using a 2MJ capacitor bank. Peak toroidal plasma currents of up to 0.7MA and peak edge poloidal fields of 0.3T are produced; lower current discharges can be sustained up to 3.5msec. When edge magnetic fluctuations are reduced below 1% by driving the plasma near threshold, it is possible to produce plasmas with Te > 150eV, e >∼4% and core χ e ∼30m 2 /s. Helicity balance for these plasmas suggests that sheath dissipation can be significant, pointing to the importance of maximizing the voltage on the coaxial injector. For most operational modes we find a stiff relationship between peak spheromak field and injector current, and little correlation with plasma temperature, which suggests that other processes than ohmic dissipation may limit field amplification. However, slowing spheromak buildup by limiting the initial current pulse increases the ratio of toroidal current to injected current and points to new operating regimes with more favorable current amplification. (author)

  19. Device-independent randomness amplification with a single device

    International Nuclear Information System (INIS)

    Plesch, Martin; Pivoluska, Matej

    2014-01-01

    Expansion and amplification of weak randomness with untrusted quantum devices has recently become a very fruitful topic of research. Here we contribute with a procedure for amplifying a single weak random source using tri-partite GHZ-type entangled states. If the quality of the source reaches a fixed threshold R=log 2 ⁡(10), perfect random bits can be produced. This technique can be used to extract randomness from sources that can't be extracted neither classically, nor by existing procedures developed for Santha–Vazirani sources. Our protocol works with a single fault-free device decomposable into three non-communicating parts, that is repeatedly reused throughout the amplification process. - Highlights: • We propose a protocol for device independent randomness amplification. • Our protocol repeatedly re-uses a single device decomposable into three parts. • Weak random sources with min-entropy rate greater than 1/4 log 2 ⁡(10) can be amplified. • Security against all-quantum adversaries is achieved

  20. Current amplification models of sensorineurall and conductive hearing loss

    Directory of Open Access Journals (Sweden)

    Ostojić Sanja

    2012-01-01

    Full Text Available The main function of a hearing aid is to improve auditory and language abilities of hearing impaired users. The amplification model has to be adapted according to age, degree and type of hearing loss. The goal of this paper is to analyze the current amplification models of sensorineural and conductive hearing loss which can provide a high quality of speech perception and sounds at any degree of hearing loss. The BAHA is a surgically implantable system for treatment of conductive hearing loss that works through direct bone conduction. BAHA is used to help people with chronic ear infections, congenital external auditory canal atresia and single sided deafness who cannot benefit from conventional hearing aids. The last generation of hearing aid for sensorineural hearing loss is cochlear implant. Bimodal amplification improves binaural hearing. Hearing aids alone do not make listening easier in all situations. The things that can interfere with listening are background noises, distance from a sound and reverberation or echo. The device used most often today is the Frequency Modulated (FM system.

  1. Diagnosis of brugian filariasis by loop-mediated isothermal amplification.

    Directory of Open Access Journals (Sweden)

    Catherine B Poole

    Full Text Available In this study we developed and evaluated a Brugia Hha I repeat loop-mediated isothermal amplification (LAMP assay for the rapid detection of Brugia genomic DNA. Amplification was detected using turbidity or fluorescence as readouts. Reactions generated a turbidity threshold value or a clear visual positive within 30 minutes using purified genomic DNA equivalent to one microfilaria. Similar results were obtained using DNA isolated from blood samples containing B. malayi microfilariae. Amplification was specific to B. malayi and B. timori, as no turbidity was observed using DNA from the related filarial parasites Wuchereria bancrofti, Onchocerca volvulus or Dirofilaria immitis, or from human or mosquito. Furthermore, the assay was most robust using a new strand-displacing DNA polymerase termed Bst 2.0 compared to wild-type Bst DNA polymerase, large fragment. The results indicate that the Brugia Hha I repeat LAMP assay is rapid, sensitive and Brugia-specific with the potential to be developed further as a field tool for diagnosis and mapping of brugian filariasis.

  2. Raman laser amplification in preformed and ionizing plasmas

    International Nuclear Information System (INIS)

    Clark, D S; Fisch, N J

    2004-01-01

    The recently proposed backward Raman laser amplification scheme utilizes the stimulated Raman backscattering in plasma of a long pumping laser pulse to amplify a short, frequency downshifted seed pulse. The output intensity for this scheme is limited by the development of forward Raman scattering (FRS) or modulational instabilities of the highly amplified seed. Theoretically, focused output intensities as high as 1025 W/cm 2 and pulse lengths of less than 100 fs could be accessible by this technique for 1 (micro)m lasers--an improvement of 10 4 -10 5 in focused intensity over current techniques. Simulations with the particle-in-cell (PIC) code Zohar are presented which investigate the effects of FRS and modulational instabilities and of Langmuir wave breaking on the output intensity for Raman amplification. Using the intense seed pulse to photoionize the plasma simultaneous with its amplification (and hence avoid plasmas-based instabilities of the pump) is also investigated by PIC simulations. It is shown that both approaches can access focused intensities in the 1025 W/cm 2 range

  3. Intrachromosomal amplification, locus deletion and point mutation in the aquaglyceroporin AQP1 gene in antimony resistant Leishmania (Viannia guyanensis.

    Directory of Open Access Journals (Sweden)

    Rubens Monte-Neto

    2015-02-01

    Full Text Available Antimony resistance complicates the treatment of infections caused by the parasite Leishmania.Using next generation sequencing, we sequenced the genome of four independent Leishmania guyanensis antimony-resistant (SbR mutants and found different chromosomal alterations including aneuploidy, intrachromosomal gene amplification and gene deletion. A segment covering 30 genes on chromosome 19 was amplified intrachromosomally in three of the four mutants. The gene coding for the multidrug resistance associated protein A involved in antimony resistance was also amplified in the four mutants, most likely through chromosomal translocation. All mutants also displayed a reduced accumulation of antimony mainly due to genomic alterations at the level of the subtelomeric region of chromosome 31 harboring the gene coding for the aquaglyceroporin 1 (LgAQP1. Resistance involved the loss of LgAQP1 through subtelomeric deletions in three mutants. Interestingly, the fourth mutant harbored a single G133D point mutation in LgAQP1 whose role in resistance was functionality confirmed through drug sensitivity and antimony accumulation assays. In contrast to the Leishmania subspecies that resort to extrachromosomal amplification, the Viannia strains studied here used intrachromosomal amplification and locus deletion.This is the first report of a naturally occurred point mutation in AQP1 in antimony resistant parasites.

  4. Signal amplification in electrochemical detection of buckwheat allergenic protein using field effect transistor biosensor by introduction of anionic surfactant

    Directory of Open Access Journals (Sweden)

    Sho Hideshima

    2016-03-01

    Full Text Available Food allergens, especially buckwheat proteins, sometimes induce anaphylactic shock in patients after ingestion. Development of a simple and rapid screening method based on a field effect transistor (FET biosensor for food allergens in food facilities or products is in demand. In this study, we achieved the FET detection of a buckwheat allergenic protein (BWp16, which is not charged enough to be electrically detected by FET biosensors, by introducing additional negative charges from anionic surfactants to the target proteins. A change in the FET characteristics reflecting surface potential caused by the adsorption of target charged proteins was observed when the target sample was coupled with the anionic surfactant (sodium dodecyl sulfate; SDS, while no significant response was detected without any surfactant treatment. It was suggested that the surfactant conjugated with the protein could be useful for the charge amplification of the target proteins. The surface plasmon resonance analysis revealed that the SDS-coupled proteins were successfully captured by the receptors immobilized on the sensing surface. Additionally, we obtained the FET responses at various concentrations of BWp16 ranging from 1 ng/mL to 10 μg/mL. These results suggest that a signal amplification method for FET biosensing is useful for allergen detection in the food industry. Keywords: Field effect transistor biosensor, Food allergen, Signal amplification, Ionic surfactant, Intrinsic charge

  5. RABL6A, a Novel RAB-Like Protein, Controls Centrosome Amplification and Chromosome Instability in Primary Fibroblasts

    Science.gov (United States)

    Zhang, Xuefeng; Hagen, Jussara; Muniz, Viviane P.; Smith, Tarik; Coombs, Gary S.; Eischen, Christine M.; Mackie, Duncan I.; Roman, David L.; Van Rheeden, Richard; Darbro, Benjamin; Tompkins, Van S.; Quelle, Dawn E.

    2013-01-01

    RABL6A (RAB-like 6 isoform A) is a novel protein that was originally identified based on its association with the Alternative Reading Frame (ARF) tumor suppressor. ARF acts through multiple p53-dependent and p53-independent pathways to prevent cancer. How RABL6A functions, to what extent it depends on ARF and p53 activity, and its importance in normal cell biology are entirely unknown. We examined the biological consequences of RABL6A silencing in primary mouse embryo fibroblasts (MEFs) that express or lack ARF, p53 or both proteins. We found that RABL6A depletion caused centrosome amplification, aneuploidy and multinucleation in MEFs regardless of ARF and p53 status. The centrosome amplification in RABL6A depleted p53−/− MEFs resulted from centrosome reduplication via Cdk2-mediated hyperphosphorylation of nucleophosmin (NPM) at threonine-199. Thus, RABL6A prevents centrosome amplification through an ARF/p53-independent mechanism that restricts NPM-T199 phosphorylation. These findings demonstrate an essential role for RABL6A in centrosome regulation and maintenance of chromosome stability in non-transformed cells, key processes that ensure genomic integrity and prevent tumorigenesis. PMID:24282525

  6. A novel CMOS image sensor system for quantitative loop-mediated isothermal amplification assays to detect food-borne pathogens.

    Science.gov (United States)

    Wang, Tiantian; Kim, Sanghyo; An, Jeong Ho

    2017-02-01

    Loop-mediated isothermal amplification (LAMP) is considered as one of the alternatives to the conventional PCR and it is an inexpensive portable diagnostic system with minimal power consumption. The present work describes the application of LAMP in real-time photon detection and quantitative analysis of nucleic acids integrated with a disposable complementary-metal-oxide semiconductor (CMOS) image sensor. This novel system works as an amplification-coupled detection platform, relying on a CMOS image sensor, with the aid of a computerized circuitry controller for the temperature and light sources. The CMOS image sensor captures the light which is passing through the sensor surface and converts into digital units using an analog-to-digital converter (ADC). This new system monitors the real-time photon variation, caused by the color changes during amplification. Escherichia coli O157 was used as a proof-of-concept target for quantitative analysis, and compared with the results for Staphylococcus aureus and Salmonella enterica to confirm the efficiency of the system. The system detected various DNA concentrations of E. coli O157 in a short time (45min), with a detection limit of 10fg/μL. The low-cost, simple, and compact design, with low power consumption, represents a significant advance in the development of a portable, sensitive, user-friendly, real-time, and quantitative analytic tools for point-of-care diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Regional amplification of ground motion in central Mexico. Results from coda-length magnitude data and preliminary modeling

    Science.gov (United States)

    Cárdenas, Martín; Chávez-García, Francisco J.; Gusev, Alexander

    Seismic ground motion in central Mexico is amplified relative to ground motion observed at the same epicentral distance along the Pacific Coast in a frequency band that includes destructive ground motion at Mexico City. Although several hypothesis have been advanced, at present there is no generally accepted explanation of such amplification. We have analyzed coda-length magnitude data reported by Servicio Sismológico Nacional (SSN) for events recorded during 1993 to increase our understanding of the spatial distribution of this phenomenon. Our results indicate that regional amplification: (a) is detected by magnitude residual computed at each station, relative to the average of SSN network;and (b) is likely related to the crustal structure under the central portion of the Transmexican Volcanic Belt (TMVB). Finally, preliminary wave propagation modelling (using SH wave, finite difference method) suggests that crustal heterogeneity is a possible cause of regional amplification. However, if this is so, it is required that both geometry and velocity distribution vary between the coast and Mexico City.

  8. The anomalous amplification of M2 tide in the Taiwan Strait

    Science.gov (United States)

    Jan, Sen; Chern, Ching-Sheng; Wang, Joe; Chao, Shenn-Yu

    2004-04-01

    The complex tidal wave propagation pattern in the Taiwan Strait invites parochialism. Along the eastern (Taiwan) boundary of the strait, the anomalous amplification of M2 tide in the middle often led to the parochial view that two tidal waves coming from both ends of the strait collide in the middle, creating wave resonance. Along the western (China) boundary, one sees a southward progressive tidal wave and hence no wave collision. To reconcile, we examine a few solutions of a numerical tidal model below. Both realistic bottom bathymetry and idealized bottom topographies are used to identify dominant mechanism leading to the complex tidal wave propagation. Our process of elimination identifies the wave reflection of southward propagating tidal wave by the deep trench in the southern strait as the true cause responsible for the complex wave propagation pattern.

  9. Amplification of electromagnetic ion cyclotron waves along a wave path in the Earth's multicomponent magnetosphere

    International Nuclear Information System (INIS)

    Hu, Y.D.; Fraser, B.J.; Olson, J.V.

    1990-01-01

    In this report, the authors consider the amplification of electromagnetic ion cyclotron waves along a geomagnetic field line in the multicomponent magnetosphere, assuming that the waves propagate parallel to the background magnetic field. The find it is possible for the ring-current protons (energy ∼ 10-100 keV), which supply the free energy to stimulate the waves, to resonate with the waves not only in the equatorial region but also off the equator. An instability, caused by a thermal anisotropy, may occur in separated regions on and/or off the equator. The positions of the source regions along the wave path depend on the concentration of cold heavy ion species. The significant off-equator source regions may be located at geomagnetic latitudes where the waves, with frequencies greater than the He + gyrofrequency on the equator, are in a local He + pass band

  10. Rapid diagnosis of equine influenza by highly sensitive silver amplification immunochromatography system.

    Science.gov (United States)

    Yamanaka, Takashi; Nemoto, Manabu; Bannai, Hiroshi; Tsujimura, Koji; Kondo, Takashi; Matsumura, Tomio; Fu, Tao Qi Huang; Fernandez, Charlene Judith; Gildea, Sarah; Cullinane, Ann

    2017-06-16

    Equine influenza (EI) is a respiratory disease caused by equine influenza A virus (EIV, H3N8) infection. Rapid diagnosis is essential to limit the disease spread. We previously reported that some rapid antigen detection (RAD) tests are fit for diagnosing EI although their sensitivity is not optimal. Here, we evaluated the performance of the newly developed RAD test using silver amplification immunochromatography (Quick Chaser Auto Flu A, B: QCA) to diagnose EI. The detection limits of QCA for EIVs were five-fold lower than the conventional RAD tests. The duration of virus antigen detection in the infected horses was longer than the conventional RAD tests. We conclude that QCA could be a valuable diagnostic method for EI.

  11. Development and preliminary evaluation of a multiplexed amplification and next generation sequencing method for viral hemorrhagic fever diagnostics.

    Directory of Open Access Journals (Sweden)

    Annika Brinkmann

    2017-11-01

    Full Text Available We describe the development and evaluation of a novel method for targeted amplification and Next Generation Sequencing (NGS-based identification of viral hemorrhagic fever (VHF agents and assess the feasibility of this approach in diagnostics.An ultrahigh-multiplex panel was designed with primers to amplify all known variants of VHF-associated viruses and relevant controls. The performance of the panel was evaluated via serially quantified nucleic acids from Yellow fever virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever (CCHF virus, Ebola virus, Junin virus and Chikungunya virus in a semiconductor-based sequencing platform. A comparison of direct NGS and targeted amplification-NGS was performed. The panel was further tested via a real-time nanopore sequencing-based platform, using clinical specimens from CCHF patients.The multiplex primer panel comprises two pools of 285 and 256 primer pairs for the identification of 46 virus species causing hemorrhagic fevers, encompassing 6,130 genetic variants of the strains involved. In silico validation revealed that the panel detected over 97% of all known genetic variants of the targeted virus species. High levels of specificity and sensitivity were observed for the tested virus strains. Targeted amplification ensured viral read detection in specimens with the lowest virus concentration (1-10 genome equivalents and enabled significant increases in specific reads over background for all viruses investigated. In clinical specimens, the panel enabled detection of the causative agent and its characterization within 10 minutes of sequencing, with sample-to-result time of less than 3.5 hours.Virus enrichment via targeted amplification followed by NGS is an applicable strategy for the diagnosis of VHFs which can be adapted for high-throughput or nanopore sequencing platforms and employed for surveillance or outbreak monitoring.

  12. Development and preliminary evaluation of a multiplexed amplification and next generation sequencing method for viral hemorrhagic fever diagnostics.

    Science.gov (United States)

    Brinkmann, Annika; Ergünay, Koray; Radonić, Aleksandar; Kocak Tufan, Zeliha; Domingo, Cristina; Nitsche, Andreas

    2017-11-01

    We describe the development and evaluation of a novel method for targeted amplification and Next Generation Sequencing (NGS)-based identification of viral hemorrhagic fever (VHF) agents and assess the feasibility of this approach in diagnostics. An ultrahigh-multiplex panel was designed with primers to amplify all known variants of VHF-associated viruses and relevant controls. The performance of the panel was evaluated via serially quantified nucleic acids from Yellow fever virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever (CCHF) virus, Ebola virus, Junin virus and Chikungunya virus in a semiconductor-based sequencing platform. A comparison of direct NGS and targeted amplification-NGS was performed. The panel was further tested via a real-time nanopore sequencing-based platform, using clinical specimens from CCHF patients. The multiplex primer panel comprises two pools of 285 and 256 primer pairs for the identification of 46 virus species causing hemorrhagic fevers, encompassing 6,130 genetic variants of the strains involved. In silico validation revealed that the panel detected over 97% of all known genetic variants of the targeted virus species. High levels of specificity and sensitivity were observed for the tested virus strains. Targeted amplification ensured viral read detection in specimens with the lowest virus concentration (1-10 genome equivalents) and enabled significant increases in specific reads over background for all viruses investigated. In clinical specimens, the panel enabled detection of the causative agent and its characterization within 10 minutes of sequencing, with sample-to-result time of less than 3.5 hours. Virus enrichment via targeted amplification followed by NGS is an applicable strategy for the diagnosis of VHFs which can be adapted for high-throughput or nanopore sequencing platforms and employed for surveillance or outbreak monitoring.

  13. A sensitive lateral flow biosensor for Escherichia coli O157:H7 detection based on aptamer mediated strand displacement amplification

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wei [College of Food Science and Engineering, Ocean University of China, Qingdao 266003 (China); Zhao, Shiming [Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China); Mao, Yiping [Yueyang Institute for Food and Drug Control, Yueyang 430198 (China); Fang, Zhiyuan [Affiliated Tumor Hospital of Guangzhou Medical University, Guangzhou 510095 (China); Lu, Xuewen [Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China); Zeng, Lingwen, E-mail: zeng6@yahoo.com [Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China)

    2015-02-25

    Highlights: • Limit of detection as low as 10 CFU mL{sup −1}Escherichia coli O157:H7. • No need of antibodies and substituted with aptamers. • Isothermal strand displacement amplification for signal amplification. • Results observed by the naked eye. • Great potential application in the area of food control. - Abstract: Foodborne diseases caused by pathogens are one of the major problems in food safety. Convenient and sensitive point-of-care rapid diagnostic tests for food-borne pathogens have been a long-felt need of clinicians. Commonly used methods for pathogen detection rely on conventional culture-based tests, antibody-based assays and polymerase chain reaction (PCR)-based techniques. These methods are costly, laborious and time-consuming. Herein, we present a simple and sensitive aptamer based biosensor for rapid detection of Escherichia coli O157:H7 (E. coli O157:H7). In this assay, two different aptamers specific for the outmembrane of E. coli O157:H7 were used. One of the aptamers was used for magnetic bead enrichment, and the other was used as a signal reporter for this pathogen, which was amplified by isothermal strand displacement amplification (SDA) and further detected by a lateral flow biosensor. Only the captured aptamers on cell membrane were amplified, limitations of conventional DNA amplification based method such as false-positive can be largely reduced. The generated signals (red bands on the test zone of a lateral flow strip) can be unambiguously read out by the naked eye. As low as 10 colony forming units (CFU) of E. coli O157:H7 were detected in this study. Without DNA extraction, the reduced handling and simpler equipment requirement render this assay a simple and rapid alternative to conventional methods.

  14. A sensitive lateral flow biosensor for Escherichia coli O157:H7 detection based on aptamer mediated strand displacement amplification

    International Nuclear Information System (INIS)

    Wu, Wei; Zhao, Shiming; Mao, Yiping; Fang, Zhiyuan; Lu, Xuewen; Zeng, Lingwen

    2015-01-01

    Highlights: • Limit of detection as low as 10 CFU mL −1 Escherichia coli O157:H7. • No need of antibodies and substituted with aptamers. • Isothermal strand displacement amplification for signal amplification. • Results observed by the naked eye. • Great potential application in the area of food control. - Abstract: Foodborne diseases caused by pathogens are one of the major problems in food safety. Convenient and sensitive point-of-care rapid diagnostic tests for food-borne pathogens have been a long-felt need of clinicians. Commonly used methods for pathogen detection rely on conventional culture-based tests, antibody-based assays and polymerase chain reaction (PCR)-based techniques. These methods are costly, laborious and time-consuming. Herein, we present a simple and sensitive aptamer based biosensor for rapid detection of Escherichia coli O157:H7 (E. coli O157:H7). In this assay, two different aptamers specific for the outmembrane of E. coli O157:H7 were used. One of the aptamers was used for magnetic bead enrichment, and the other was used as a signal reporter for this pathogen, which was amplified by isothermal strand displacement amplification (SDA) and further detected by a lateral flow biosensor. Only the captured aptamers on cell membrane were amplified, limitations of conventional DNA amplification based method such as false-positive can be largely reduced. The generated signals (red bands on the test zone of a lateral flow strip) can be unambiguously read out by the naked eye. As low as 10 colony forming units (CFU) of E. coli O157:H7 were detected in this study. Without DNA extraction, the reduced handling and simpler equipment requirement render this assay a simple and rapid alternative to conventional methods

  15. Toehold-mediated nonenzymatic amplification circuit on graphene oxide fluorescence switching platform for sensitive and homogeneous microRNA detection

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ru; Liao, Yuhui; Zhou, Xiaoming, E-mail: zhouxm@scnu.edu.cn; Xing, Da, E-mail: xingda@scnu.edu.cn

    2015-08-12

    A novel graphene oxide (GO) fluorescence switch-based homogenous system has been developed to solve two problems that are commonly encountered in conventional GO-based biosensors. First, with the assistance of toehold-mediated nonenzymatic amplification (TMNA), the sensitivity of this system greatly surpasses that of previously described GO-based biosensors, which are always limited to the nM range due to the lack of efficient signal amplification. Second, without enzymatic participation in amplification, the unreliability of detection resulting from nonspecific desorption of DNA probes on the GO surface by enzymatic protein can be avoided. Moreover, the interaction mechanism of the double-stranded TMNA products contains several single-stranded toeholds at two ends and GO has also been explored with combinations of atomic force microscopy imaging, zeta potential detection, and fluorescence assays. It has been shown that the hybrids can be anchored to the surface of GO through the end with more unpaired bases, and that the other end, which has weaker interaction with GO, can escape GO adsorption due to the robustness of the central dsDNA structures. We verified this GO fluorescence switch-based detection system by detecting microRNA 21, an overexpressed non-encoding gene in a variety of malignant cells. Rational design of the probes allowed the isothermal nonenzymatic reaction to achieve more than 100-fold amplification efficiency. The detection results showed that our strategy has a detection limit of 10 pM and a detection range of four orders of magnitude. - Highlights: • This paper explored the interaction mechanism of TMNA products with GO surface. • This homogeneous and isothermal system permits a detection limit of 10 pM for microRNA. • This nonenzymatic strategy can avoid nonspecific desorption caused by enzyme protein. • The interaction model can be used to explore the application ability of nonenzymatic circuit.

  16. Unstable mutations: cause of some neurological hereditary diseases

    International Nuclear Information System (INIS)

    Cuenca Berger, P.; Morales Montero, F.

    1999-01-01

    Unstable mutations or amplification of triplets constitute a kind of genetic alteration discovered during the last decade. They had been found inside or near genes important for the normal neurological function of the human being. In some cases, the presence of the amplification causes the inactivation of the gene or the synthesis of a new product which functions different from the original protein. Some common characteristics of diseases caused by the amplification of triplets are that it affects the nervous system and are degenerative in nature. The expression of the manifestations varies according to age. Most of them show genetic anticipation in which the severity of the manifestations increases with each generation and appear at an earlier age. In most cases, the severity of the symptoms is correlated positively to the size of the amplification. The diagnosis of an affected individual in a family may indicate the presence of an altered gene in other relatives. These relatives may not present evident signs of the illness either because it is of late onset or because they carry premutations. The molecular diagnosis of these mutations is important to estimate the risk of developing the disease and/or of transmitting the illness to the descendants and to eliminate the fears of healthy relatives who have inherited normal copies of the gene. (Author) [es

  17. GAB2 amplifications refine molecular classification of melanoma.

    Science.gov (United States)

    Chernoff, Karen A; Bordone, Lindsey; Horst, Basil; Simon, Katherine; Twadell, William; Lee, Keagan; Cohen, Jason A; Wang, Shuang; Silvers, David N; Brunner, Georg; Celebi, Julide Tok

    2009-07-01

    Gain-of-function mutations in BRAF, NRAS, or KIT are associated with distinct melanoma subtypes with KIT mutations and/or copy number changes frequently observed among melanomas arising from sun-protected sites, such as acral skin (palms, soles, and nail bed) and mucous membranes. GAB2 has recently been implicated in melanoma pathogenesis, and increased copy numbers are found in a subset of melanomas. We sought to determine the association of increased copy numbers of GAB2 among melanoma subtypes in the context of genetic alterations in BRAF, NRAS, and KIT. A total of 85 melanomas arising from sun-protected (n = 23) and sun-exposed sites (n = 62) were analyzed for copy number changes using array-based comparative genomic hybridization and for gain-of-function mutations in BRAF, NRAS, and KIT. GAB2 amplifications were found in 9% of the cases and were associated with melanomas arising from acral and mucosal sites (P = 0.005). Increased copy numbers of the KIT locus were observed in 6% of the cases. The overall mutation frequencies for BRAF and NRAS were 43.5% and 14%, respectively, and were mutually exclusive. Among the acral and mucosal melanomas studied, the genetic alteration frequency was 26% for GAB2, 13% for KIT, 30% for BRAF, and 4% for NRAS. Importantly, the majority of GAB2 amplifications occurred independent from genetic events in BRAF, NRAS, and KIT. GAB2 amplification is critical for melanomas arising from sun-protected sites. Genetic alterations in GAB2 will help refine the molecular classification of melanomas.

  18. Combined Amplification and Sound Generation for Tinnitus: A Scoping Review.

    Science.gov (United States)

    Tutaj, Lindsey; Hoare, Derek J; Sereda, Magdalena

    In most cases, tinnitus is accompanied by some degree of hearing loss. Current tinnitus management guidelines recognize the importance of addressing hearing difficulties, with hearing aids being a common option. Sound therapy is the preferred mode of audiological tinnitus management in many countries, including in the United Kingdom. Combination instruments provide a further option for those with an aidable hearing loss, as they combine amplification with a sound generation option. The aims of this scoping review were to catalog the existing body of evidence on combined amplification and sound generation for tinnitus and consider opportunities for further research or evidence synthesis. A scoping review is a rigorous way to identify and review an established body of knowledge in the field for suggestive but not definitive findings and gaps in current knowledge. A wide variety of databases were used to ensure that all relevant records within the scope of this review were captured, including gray literature, conference proceedings, dissertations and theses, and peer-reviewed articles. Data were gathered using scoping review methodology and consisted of the following steps: (1) identifying potentially relevant records; (2) selecting relevant records; (3) extracting data; and (4) collating, summarizing, and reporting results. Searches using 20 different databases covered peer-reviewed and gray literature and returned 5959 records. After exclusion of duplicates and works that were out of scope, 89 records remained for further analysis. A large number of records identified varied considerably in methodology, applied management programs, and type of devices. There were significant differences in practice between different countries and clinics regarding candidature and fitting of combination aids, partly driven by the application of different management programs. Further studies on the use and effects of combined amplification and sound generation for tinnitus are

  19. Precision phase estimation based on weak-value amplification

    Science.gov (United States)

    Qiu, Xiaodong; Xie, Linguo; Liu, Xiong; Luo, Lan; Li, Zhaoxue; Zhang, Zhiyou; Du, Jinglei

    2017-02-01

    In this letter, we propose a precision method for phase estimation based on the weak-value amplification (WVA) technique using a monochromatic light source. The anomalous WVA significantly suppresses the technical noise with respect to the intensity difference signal induced by the phase delay when the post-selection procedure comes into play. The phase measured precision of this method is proportional to the weak-value of a polarization operator in the experimental range. Our results compete well with the wide spectrum light phase weak measurements and outperform the standard homodyne phase detection technique.

  20. Amplification of magnetic modes in laser-created plasmas

    International Nuclear Information System (INIS)

    Matte, J.P.; Bendib, A.; Luciani, J.F.

    1987-01-01

    The amplification of magnetic (Weibel) modes in laser-plasma interaction is investigated by use of unperturbed distribution functions given by Fokker-Planck simulations and a dispersion relation valid for all collisionality regimes. In the five cases studied, a strongly growing mode is found in the underdense plasma, where v-bar/sub x/ 2 2 , and the usual slowly growing one in the overdense plasma. The first mode grows convectively outwards by more than 10 4 . The convection velocities are found to be very different from Nernst values

  1. Processes of synchronization, chaotization and amplification in a germanium oscillistor

    Energy Technology Data Exchange (ETDEWEB)

    Abakarova, N.S.; Aliev, K.M.; Ibragimov, Kh.O.; Kamilov, I.K. [Institute of Physics, Dagestan Science Centre, RAS, Makhachkala (Russian Federation)

    2001-12-03

    The effect of an external harmonic signal on the screw instability of the current in the electron-hole plasma has been studied experimentally in Ge at 77 K and 300 K. The influence exerted by external signals with various amplitudes and frequencies, applied to a sample both additively and multiplicatively, on the synchronization, amplification and stability of the system in absolute and convective modes of instability excitation has been investigated at points of bifurcation in a wide region of the parametric space. (author)

  2. Rapid detection of Mycobacterium tuberculosis by recombinase polymerase amplification.

    Directory of Open Access Journals (Sweden)

    David S Boyle

    Full Text Available Improved access to effective tests for diagnosing tuberculosis (TB has been designated a public health priority by the World Health Organisation. In high burden TB countries nucleic acid based TB tests have been restricted to centralised laboratories and specialised research settings. Requirements such as a constant electrical supply, air conditioning and skilled, computer literate operators prevent implementation of such tests in many settings. Isothermal DNA amplification technologies permit the use of simpler, less energy intensive detection platforms more suited to low resource settings that allow the accurate diagnosis of a disease within a short timeframe. Recombinase Polymerase Amplification (RPA is a rapid, low temperature isothermal DNA amplification reaction. We report here RPA-based detection of Mycobacterium tuberculosis complex (MTC DNA in <20 minutes at 39 °C. Assays for two MTC specific targets were investigated, IS6110 and IS1081. When testing purified MTC genomic DNA, limits of detection of 6.25 fg (IS6110 and 20 fg (IS1081were consistently achieved. When testing a convenience sample of pulmonary specimens from suspected TB patients, RPA demonstrated superior accuracy to indirect fluorescence microscopy. Compared to culture, sensitivities for the IS1081 RPA and microscopy were 91.4% (95%CI: 85, 97.9 and 86.1% (95%CI: 78.1, 94.1 respectively (n = 71. Specificities were 100% and 88.6% (95% CI: 80.8, 96.1 respectively. For the IS6110 RPA and microscopy sensitivities of 87.5% (95%CI: 81.7, 93.2 and 70.8% (95%CI: 62.9, 78.7 were obtained (n = 90. Specificities were 95.4 (95% CI: 92.3,98.1 and 88% (95% CI: 83.6, 92.4 respectively. The superior specificity of RPA for detecting tuberculosis was due to the reduced ability of fluorescence microscopy to distinguish Mtb complex from other acid fast bacteria. The rapid nature of the RPA assay and its low energy requirement compared to other amplification technologies suggest RPA-based TB

  3. Quantum quench in one dimension: coherent inhomogeneity amplification and "supersolitons".

    Science.gov (United States)

    Foster, Matthew S; Yuzbashyan, Emil A; Altshuler, Boris L

    2010-09-24

    We study a quantum quench in a 1D system possessing Luttinger liquid (LL) and Mott insulating ground states before and after the quench, respectively. We show that the quench induces power law amplification in time of any particle density inhomogeneity in the initial LL ground state. The scaling exponent is set by the fractionalization of the LL quasiparticle number relative to the insulator. As an illustration, we consider the traveling density waves launched from an initial localized density bump. While these waves exhibit a particular rigid shape, their amplitudes grow without bound.

  4. Sheared flow amplification by vacuum magnetic islands in stellarator plasmas

    International Nuclear Information System (INIS)

    Garcia, L.; Carreras, B. A.; Lynch, V. E.; Pedrosa, M. A.; Hidalgo, C.

    2001-01-01

    There is some experimental evidence that the E x B flows have radial structure that may be linked to rational surfaces. This flow structure may result from a self-organization process involving nonlinear flow amplification through Reynolds stress and fluctuation reduction by sheared flows. In stellarators, a large contribution to the Reynolds stress comes from the coupling of the magnetic field component of a vacuum field island with a plasma instability. In this process, the self-organization principle seems to be marginal stability for the fluctuations driving the flow

  5. Soft X-Ray amplification in laser plasmas

    International Nuclear Information System (INIS)

    Louis-Jacquet, M.

    1988-01-01

    The principles, experiments and theoretical models of soft x-ray, amplification, produced in laser plasmas, are studied. In the discussion of the principles, the laser plasma medium, the definition of the gain, the population inversions, saturation and superradiance are described. The results concerning recombination and collisional excitation experiments, as well as experimental devices are shown. A complete physical simulation to design and interpret x-ray laser experiments is given. Applications of x-ray lasers in grating production techniques, in contact microscopy and holography are considered

  6. Josephson Parametric Amplification for Circuit Quantum Electrodynamics: Theory and Implementation

    Science.gov (United States)

    2013-05-01

    especially Will McFaul and Anasua Chatterjee. I (and all other lab members) also thank Mr. Bean , our coffee /espresso machine, for always being there. Next, I...a chain of amplifiers [15,16], an initial amplification with a low noise figure and high gain will lead to an effective SNR at later stages of...product of such a state is the minimum possible for the harmonic oscillator. The expectation value rotates clockwise about the origin of the Re[a], Im[a

  7. Laser light triggers increased Raman amplification in the regime of nonlinear Landau damping

    International Nuclear Information System (INIS)

    Depierreux, S.; Goyon, C.; Masson-Laborde, P.E.; Yahia, V.; Loisel, G.; Labaune, C.

    2014-01-01

    Stimulated Raman backscattering (SRS) has many unwanted effects in megajoule-scale inertially confined fusion (ICF) plasmas. Moreover, attempts to harness SRS to amplify short laser pulses through backward Raman amplification have achieved limited success. In high temperature fusion plasmas, SRS usually occurs in a kinetic regime where the nonlinear response of the Langmuir wave to the laser drive and its host of complicating factors make it difficult to predict the degree of amplification that can be achieved under given experimental conditions. Here we present experimental evidence of reduced Landau damping with increasing Langmuir wave amplitude and determine its effects on Raman amplification. The threshold for trapping effects to influence the amplification is shown to be very low. Above threshold, the complex SRS dynamics results in increased amplification factors, which partly explains previous ICF experiments. These insights could aid the development of more efficient backward Raman amplification schemes in this regime. (authors)

  8. Optical parametric amplification and oscillation assisted by low-frequency stimulated emission

    OpenAIRE

    Longhi, Stefano

    2016-01-01

    Optical parametric amplification/oscillation provide a powerful tool for coherent light generation in spectral regions inaccessible to lasers. Parametric gain is based on a frequency {\\it down-conversion} process, and thus it can not be realized for signal waves at a frequency $\\omega_3$ {\\it higher} than the frequency of the pump wave $\\omega_1$. In this work we suggest a route toward the realization of {\\it up-conversion} optical parametric amplification and oscillation, i.e. amplification ...

  9. Observational Evidence for Enhanced Greenhouse Effect Reinforcing Wintertime Arctic Amplification and Sea Ice Melting Onset

    Science.gov (United States)

    Cao, Y.; Liang, S.

    2017-12-01

    Despite an apparent hiatus in global warming, the Arctic climate continues to experience unprecedented changes. Summer sea ice is retreating at an accelerated rate, and surface temperatures in this region are rising at a rate double that of the global average, a phenomenon known as Arctic amplification. Although a lot of efforts have been made, the causes this unprecedented phenomenon remain unclear and are subjects of considerable debate. In this study, we report strong observational evidence, for the first time from long-term (1984-2014) spatially complete satellite records, that increased cloudiness and atmospheric water vapor in winter and spring have caused an extraordinary downward longwave radiative flux to the ice surface, which may then amplify the Arctic wintertime ice-surface warming. In addition, we also provide observed evidence that it is quite likely the enhancement of the wintertime greenhouse effect caused by water vapor and cloudiness has advanced the time of onset of ice melting in mid-May through inhibiting sea-ice refreezing in the winter and accelerating the pre-melting process in the spring, and in turn triggered the positive sea-ice albedo feedback process and accelerated the sea ice melting in the summer.

  10. Precipitation of PEG/Carboxyl-Modified Gold Nanoparticles with Magnesium Pyrophosphate: A New Platform for Real-Time Monitoring of Loop-Mediated Isothermal Amplification.

    Science.gov (United States)

    Qin, Ailin; Fu, Lok Tin; Wong, Jacky K F; Chau, Li Yin; Yip, Shea Ping; Lee, Thomas M H

    2017-03-29

    Gold nanoparticles have proven to be promising for decentralized nucleic acid testing by virtue of their simple visual readout and absorbance-based quantification. A major challenge toward their practical application is to achieve ultrasensitive detection without compromising simplicity. The conventional strategy of thermocycling amplification is unfavorable (because of both instrumentation and preparation of thermostable oligonucleotide-modified gold nanoparticle probes). Herein, on the basis of a previously unreported co-precipitation phenomenon between thiolated poly(ethylene glycol)/11-mercaptoundecanoic acid co-modified gold nanoparticles and magnesium pyrophosphate crystals (an isothermal DNA amplification reaction byproduct), a new ultrasensitive and simple DNA assay platform is developed. The binding mechanism underlying the co-precipitation phenomenon is found to be caused by the complexation of carboxyl and pyrophosphate with free magnesium ions. Remarkably, poly(ethylene glycol) does not hinder the binding and effectively stabilizes gold nanoparticles against magnesium ion-induced aggregation (without pyrophosphate). In fact, a similar phenomenon is observed in other poly(ethylene glycol)- and carboxyl-containing nanomaterials. When the gold nanoparticle probe is incorporated into a loop-mediated isothermal amplification reaction, it remains as a red dispersion for a negative sample (in the absence of a target DNA sequence) but appears as a red precipitate for a positive sample (in the presence of a target). This results in a first-of-its-kind gold nanoparticle-based DNA assay platform with isothermal amplification and real-time monitoring capabilities.

  11. A cascade amplification strategy based on rolling circle amplification and hydroxylamine amplified gold nanoparticles enables chemiluminescence detection of adenosine triphosphate.

    Science.gov (United States)

    Wang, Ping; Zhang, Tonghuan; Yang, Taoyi; Jin, Nan; Zhao, Yanjun; Fan, Aiping

    2014-08-07

    A highly sensitive and selective chemiluminescent (CL) biosensor for adenosine triphosphate (ATP) was developed by taking advantage of the ATP-dependent enzymatic reaction (ATP-DER), the powerful signal amplification capability of rolling circle amplification (RCA), and hydroxylamine-amplified gold nanoparticles (Au NPs). The strategy relies on the ability of ATP, a cofactor of T4 DNA ligase, to trigger the ligation-RCA reaction. In the presence of ATP, the T4 DNA ligase catalyzes the ligation reaction between the two ends of the padlock probe, producing a closed circular DNA template that initiates the RCA reaction with phi29 DNA polymerase and dNTP. Therein, many complementary copies of the circular template can be generated. The ATP-DER is eventually converted into a detectable CL signal after a series of processes, including gold probe hybridization, hydroxylamine amplification, and oxidative gold metal dissolution coupled with a simple and sensitive luminol CL reaction. The CL signal is directly proportional to the ATP level. The results showed that the detection limit of the assay is 100 pM of ATP, which compares favorably with those of other ATP detection techniques. In addition, by taking advantage of ATP-DER, the proposed CL sensing system exhibits extraordinary specificity towards ATP and could distinguish the target molecule ATP from its analogues. The proposed method provides a new and versatile platform for the design of novel DNA ligation reaction-based CL sensing systems for other cofactors. This novel ATP-DER based CL sensing system may find wide applications in clinical diagnosis as well as in environmental and biomedical fields.

  12. Chaotic amplification of neutrino chemical potentials by neutrino oscillations in big bang nucleosynthesis

    International Nuclear Information System (INIS)

    Shi, X.

    1996-01-01

    We investigate in detail the parameter space of active-sterile neutrino oscillations that amplifies neutrino chemical potentials at the epoch of big bang nucleosynthesis. We calculate the magnitude of the amplification and show evidence of chaos in the amplification process. We also discuss the implications of the neutrino chemical potential amplification in big bang nucleosynthesis. It is shown that with a ∼1 eV ν e , the amplification of its chemical potential by active-sterile neutrino oscillations can lower the effective number of neutrino species at big bang nucleosynthesis to significantly below three. copyright 1996 The American Physical Society

  13. Chaotic amplification of neutrino chemical potentials by neutrino oscillations in big bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Shi, X. [Department of Physics, Queen`s University, Kingston, Ontario, K7L 3N6 (CANADA)

    1996-08-01

    We investigate in detail the parameter space of active-sterile neutrino oscillations that amplifies neutrino chemical potentials at the epoch of big bang nucleosynthesis. We calculate the magnitude of the amplification and show evidence of chaos in the amplification process. We also discuss the implications of the neutrino chemical potential amplification in big bang nucleosynthesis. It is shown that with a {approximately}1 eV {nu}{sub {ital e}}, the amplification of its chemical potential by active-sterile neutrino oscillations can lower the effective number of neutrino species at big bang nucleosynthesis to significantly below three. {copyright} {ital 1996 The American Physical Society.}

  14. CDK4 amplification predicts recurrence of well-differentiated liposarcoma of the abdomen.

    Directory of Open Access Journals (Sweden)

    Sanghoon Lee

    Full Text Available The absence of CDK4 amplification in liposarcomas is associated with favorable prognosis. We aimed to identify the factors associated with tumor recurrence in patients with well-differentiated (WD and dedifferentiated (DD liposarcomas.From 2000 to 2010, surgical resections for 101 WD and DD liposarcomas were performed. Cases in which complete surgical resections with curative intent were carried out were selected. MDM2 and CDK4 gene amplification were analyzed by quantitative real-time polymerase chain reaction (Q-PCR.There were 31 WD and 17 DD liposarcomas. Locoregional recurrence was observed in 11 WD and 3 DD liposarcomas. WD liposarcomas showed better patient survival compared to DD liposarcomas (P<0.05. Q-PCR analysis of the liposarcomas revealed the presence of CDK4 amplification in 44 cases (91.7% and MDM2 amplification in 46 cases (95.8%. WD liposarcomas with recurrence after surgical resection had significantly higher levels of CDK4 amplification compared to those without recurrence (P = 0.041. High level of CDK4 amplification (cases with CDK4 amplification higher than the median 7.54 was associated with poor recurrence-free survival compared to low CDK4 amplification in both univariate (P = 0.012 and multivariate analyses (P = 0.020.Level of CDK4 amplification determined by Q-PCR was associated with the recurrence of WD liposarcomas after surgical resection.

  15. Rapid and sensitive detection of Didymella bryoniae by visual loop-mediated isothermal amplification assay

    Directory of Open Access Journals (Sweden)

    Xiefeng Yao

    2016-08-01

    Full Text Available Didymella bryoniae is a pathogenic fungus that causes gummy stem blight (GSB in Cucurbitaceae crops (e.g. cantaloupe, muskmelon, cucumber, and watermelon. GSB produces lesions on the stems and leaves, and can also be spread by seeds. Here, we developed a rapid, visual, and sensitive loop-mediated amplification (LAMP assay for D. bryoniae detection based on sequence-characterized amplified regions (GenBank accession nos GQ872461 and GQ872462 common to the two random amplification of polymorphic DNA group genotypes (RGI and RGII of D. bryoniae; ideal conditions for detection were optimized for completion in 45 min at 63°C. The sensitivity and specificity of the LAMP assay were further analyzed in comparison with those of a conventional polymerase chain reaction (PCR. The sensitivity of the LAMP assay was 1000-fold higher than that of conventional PCR with a detection limit of 0.1 fg μL−1 of targeted DNA. The LAMP assay could be accomplished in about 45 min, with the results visible to the naked eye. The assay showed high specificity in discriminating all D. bryoniae isolates from seven other fungal pathogens that occur in Cucurbitaceae crops. The LAMP assay also detected D. bryoniae infection in young muskmelon leaves with suspected early symptoms of GSB disease. Hence, the technique has great potential for developing rapid and sensitive visual detection methods for the D. bryoniae pathogen in crops and seeds. This method has potential application in early prediction of disease and reducing the risk of epidemics.

  16. Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle

    Science.gov (United States)

    McNeil, Ben I.; Sasse, Tristan P.

    2016-01-01

    High carbon dioxide (CO2) concentrations in sea-water (ocean hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual variations in oceanic CO2 concentration, but there is a lack of relevant global observational data. Here we identify global ocean patterns of monthly variability in carbon concentration using observations that allow us to examine the evolution of surface-ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We predict that the present-day amplitude of the natural oscillations in oceanic CO2 concentration will be amplified by up to tenfold in some regions by 2100, if atmospheric CO2 concentrations continue to rise throughout this century (according to the RCP8.5 scenario of the Intergovernmental Panel on Climate Change). The findings from our data are broadly consistent with projections from Earth system climate models. Our predicted amplification of the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic oceans to hypercapnia many decades earlier than is expected from average atmospheric CO2 concentrations. We suggest that these ocean ‘CO2 hotspots’ evolve as a combination of the strong seasonal dynamics of CO2 concentration and the long-term effective storage of anthropogenic CO2 in the oceans that lowers the buffer capacity in these regions, causing a nonlinear amplification of CO2 concentration over the annual cycle. The onset of ocean hypercapnia (when the partial pressure of CO2 in sea-water exceeds 1,000 micro-atmospheres) is forecast for atmospheric CO2 concentrations that exceed 650 parts per million, with hypercapnia expected in up to half the surface ocean by 2100, assuming a high-emissions scenario (RCP8.5). Such extensive ocean hypercapnia has detrimental implications for

  17. Electrochemical DNA biosensor based on MNAzyme-mediated signal amplification

    International Nuclear Information System (INIS)

    Diao, Wei; Tang, Min; Ding, Xiaojuan; Zhang, Ye; Yang, Jianru; Cheng, Wenbin; Mo, Fei; Wen, Bo; Xu, Lulu; Yan, Yurong

    2016-01-01

    The authors describe an electrochemical sensing strategy for highly sensitive and specific detection of target (analyte) DNA based on an amplification scheme mediated by a multicomponent nucleic acid enzyme (MNAzyme). MNAzymes were formed by multicomponent complexes which produce amplified “output” signals in response to specific “input” signal. In the presence of target nucleic acid, multiple partial enzymes (partzymes) oligonucleotides are assembled to form active MNAzymes. These can cleave H0 substrate into two pieces, thereby releasing the activated MNAzyme to undergo an additional cycle of amplification. Here, the two pieces contain a biotin-tagged sequence and a byproduct. The biotin-tagged sequences are specifically captured by the detection probes immobilized on the gold electrode. By employing streptavidinylated alkaline phosphatase as an enzyme label, an electrochemical signal is obtained. The electrode, if operated at a working potential of 0.25 V (vs. Ag/AgCl) in solution of pH 7.5, covers the 100 pM to 0.25 μM DNA concentration range, with a 79 pM detection limit. In our perception, the strategy introduced here has a wider potential in that it may be applied to molecular diagnostics and pathogen detection. (author)

  18. Static and Dynamic Amplification Using Strong Mechanical Coupling

    KAUST Repository

    Ilyas, Saad

    2016-07-28

    Amplifying the signal-to-noise ratio of resonant sensors is vital toward the effort to miniaturize devices into the sub-micro and nano regimes. In this paper, we demonstrate theoretically and experimentally, amplification through mechanically coupled microbeams. The device is composed of two identical clamped-clamped beams, made of polyimide, connected at their middle through a third beam, which acts as a mechanical coupler. Each of the clamped-clamped microbeams and the coupler are designed to be actuated separately, hence providing various possibilities of actuation and sensing. The coupled resonator is driven into resonance near its first resonance mode and its dynamic behavior is explored via frequency sweeps. The results show significant amplification in the resonator amplitude when the signal is measured at the midpoint of the coupler compared with the response of the individual uncoupled beams. The static pull-in characteristics of the resonator are also studied. It is shown that the compliant mechanical coupler can serve as a low-power radio frequency switch actuated at low voltage loads. [2016-0100

  19. Primer Extension Mutagenesis Powered by Selective Rolling Circle Amplification

    Science.gov (United States)

    Huovinen, Tuomas; Brockmann, Eeva-Christine; Akter, Sultana; Perez-Gamarra, Susan; Ylä-Pelto, Jani; Liu, Yuan; Lamminmäki, Urpo

    2012-01-01

    Primer extension mutagenesis is a popular tool to create libraries for in vitro evolution experiments. Here we describe a further improvement of the method described by T.A. Kunkel using uracil-containing single-stranded DNA as the template for the primer extension by additional uracil-DNA glycosylase treatment and rolling circle amplification (RCA) steps. It is shown that removal of uracil bases from the template leads to selective amplification of the nascently synthesized circular DNA strand carrying the desired mutations by phi29 DNA polymerase. Selective RCA (sRCA) of the DNA heteroduplex formed in Kunkel's mutagenesis increases the mutagenesis efficiency from 50% close to 100% and the number of transformants 300-fold without notable diversity bias. We also observed that both the mutated and the wild-type DNA were present in at least one third of the cells transformed directly with Kunkel's heteroduplex. In contrast, the cells transformed with sRCA product contained only mutated DNA. In sRCA, the complex cell-based selection for the mutant strand is replaced with the more controllable enzyme-based selection and less DNA is needed for library creation. Construction of a gene library of ten billion members is demonstrated with the described method with 240 nanograms of DNA as starting material. PMID:22355397

  20. Health Risk Information Engagement and Amplification on Social Media.

    Science.gov (United States)

    Strekalova, Yulia A

    2017-04-01

    Emerging pandemics call for unique health communication and education strategies in which public health agencies need to satisfy the public's information needs about possible risks while preventing risk exaggeration and dramatization. As a route to providing a framework for understanding public information behaviors in response to an emerging pandemic, this study examined the characteristics of communicative behaviors of social media audiences in response to Ebola outbreak news. Grounded in the social amplification of risks framework, this study adds to an understanding of information behaviors of online audiences by showing empirical differences in audience engagement with online health information. The data were collected from the Centers for Disease Control and Prevention (CDC) Facebook channel. The final data set included 809 CDC posts and 35,916 audience comments. The analysis identified the differences in audience information behaviors in response to an emerging pandemic, Ebola, and health promotion posts. While the CDC had fewer posts on Ebola than health promotion topics, the former received more attention from active page users. Furthermore, audience members who actively engaged with Ebola news had a small overlap with those who engaged with non-Ebola information during the same period. Overall, this study demonstrated that information behavior and audience engagement is topic dependent. Furthermore, audiences who commented on news about an emerging pandemic were homogenous and varied in their degree of information amplification.

  1. Beyond Words: Amplification of Cancer Risk Communication on Social Media.

    Science.gov (United States)

    Strekalova, Yulia A; Krieger, Janice L

    2017-10-01

    Social media provide a unique channel for disseminating evidence-based information to diverse audiences and organizational and private stakeholders, thus facilitating a dialog about health and health risks. Guided by the social amplification of risk framework, the goal of this study was to assess the level of audience engagement with messages posted on the National Cancer Institute (NCI) Facebook page and evaluate the differences in the audience information behavior toward risk-related and non-risk posts. Data included 1,975 posts published on the NCI Facebook page as well as the corresponding 4,537 comments, 77,298 shares, and 145,462 likes. Links and images were the top two most frequent types of content for both risk-related and non-risk posts, but risk-related messages were more amplified through comments, shares, and likes. Comparing the modality of risk-related messages, videos, contrary to the prediction, were not more effective in attracting audience engagement than images. Finally, comments to risk-related posts did not repeat risk-related language suggesting that future studies should examine risk signal recognition and dissemination as separate behaviors. This study's findings emphasize the importance of focused investigation of message design strategies and message effects on the dissemination and amplification of communication related to health risks.

  2. Tumor target amplification: Implications for nano drug delivery systems.

    Science.gov (United States)

    Seidi, Khaled; Neubauer, Heidi A; Moriggl, Richard; Jahanban-Esfahlan, Rana; Javaheri, Tahereh

    2018-04-10

    Tumor cells overexpress surface markers which are absent from normal cells. These tumor-restricted antigenic signatures are a fundamental basis for distinguishing on-target from off-target cells for ligand-directed targeting of cancer cells. Unfortunately, tumor heterogeneity impedes the establishment of a solid expression pattern for a given target marker, leading to drastic changes in quality (availability) and quantity (number) of the target. Consequently, a subset of cancer cells remains untargeted during the course of treatment, which subsequently promotes drug-resistance and cancer relapse. Since target inefficiency is only problematic for cancer treatment and not for treatment of other pathological conditions such as viral/bacterial infections, target amplification or the generation of novel targets is key to providing eligible antigenic markers for effective targeted therapy. This review summarizes the limitations of current ligand-directed targeting strategies and provides a comprehensive overview of tumor target amplification strategies, including self-amplifying systems, dual targeting, artificial markers and peptide modification. We also discuss the therapeutic and diagnostic potential of these approaches, the underlying mechanism(s) and established methodologies, mostly in the context of different nanodelivery systems, to facilitate more effective ligand-directed cancer cell monitoring and targeting. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Ultrashort pulse shaping by optical parametric chirped amplification

    International Nuclear Information System (INIS)

    Nelet, Ambre

    2007-01-01

    The aim of this work is to propose new laser architectures based on optical parametric chirped pulse amplification (OPCPA). Common goals of OPCPA pre-amplifiers are to reach high energy level while maintaining the spectrum width and to adapt geometry of the amplified beam to the high power laser chain optics. We consider OPCPA as a way to control and to sculpt ultrashort pulses. Our first set-up aims at thwarting possible time recovery default between pump and signal pulses, which lower the energy extraction. A regenerative OPCPA, idler resonant, is a way to produce a high-intensity and high-repetition rate train of amplified signal replicas. Our second laser system pre-compensates the spectral gain narrowing by sculpting pulses directly within the OPCPA section, where a temporal shaping of the pump beam permits a spectro-spectral shaping of the amplified signal. Finally, we propose an OPCPA based on spatial coding and uniform amplification of spectral signal components by using a fan-out periodically poled crystal and a zero dispersion line. (author) [fr

  4. Amplification of terahertz pulses in gases beyond thermodynamic equilibrium

    Science.gov (United States)

    Schwaab, G. W.; Schroeck, K.; Havenith, M.

    2007-03-01

    In Ebbinghaus [Plasma Sources Sci. Technol. 15, 72 (2006)] we reported terahertz time-domain spectroscopy in a plasma at low pressure, we observed a simultaneous absorption and amplification process within each single rotational transition. Here we show that this observation is a direct consequence of the short interaction time of the pulsed terahertz radiation with the plasma, which is shorter than the average collision time between the molecules. Thus, during the measurement time the molecular states may be considered entangled. Solution of the time-dependent Schrödinger equation yields a linear term that may be neglected for long observation times, large frequencies, or nonentangled states. We determine the restrictions for the observation of this effect and calculate the spectrum of a simple diatomic molecule. Using this model we are able to explain the spectral features showing a change from emission to absorption as observed previously. In addition we find that the amplification and absorption do not follow the typical Lambert-Beer exponential law but an approximate square law.

  5. Social amplification of risk in the Internet environment.

    Science.gov (United States)

    Chung, Ik Jae

    2011-12-01

    This article analyzes the dynamic process of risk amplification in the Internet environment with special emphasis on public concern for environmental risks from a high-speed railway tunnel construction project in South Korea. Environmental organizations and activists serving as social stations collected information about the project and its ecological impact, and communicated this with the general public, social groups, and institutions. The Internet provides social stations and the public with an efficient means for interactive communication and an open space for active information sharing and public participation. For example, while the website of an organization such as an environmental activist group can initially trigger local interest, the Internet allows this information to be disseminated to a much wider audience in a manner unavailable to the traditional media. Interaction among social stations demonstrates an amplifying process of public attention to the risk. Analyses of the volume of readers' comments to online newspaper articles and public opinions posted on message board of public and nonprofit organizations show the ripple effects of the amplification process as measured along temporal, geographical, and sectoral dimensions. Public attention is also influenced by the symbolic connotations of risk information. Interpretations of risk in religious, political, or legal terms intensify public concern for the environmental risk. © 2011 Society for Risk Analysis.

  6. Impaired conscious access and abnormal attentional amplification in schizophrenia

    Directory of Open Access Journals (Sweden)

    L. Berkovitch

    Full Text Available Previous research suggests that the conscious perception of a masked stimulus is impaired in schizophrenia, while unconscious bottom-up processing of the same stimulus, as assessed by subliminal priming, can be preserved. Here, we test this postulated dissociation between intact bottom-up and impaired top-down processing and evaluate its brain mechanisms using high-density recordings of event-related potentials. Sixteen patients with schizophrenia and sixteen controls were exposed to peripheral digits with various degrees of visibility, under conditions of either focused attention or distraction by another task. In the distraction condition, the brain activity evoked by masked digits was drastically reduced in both groups, but early bottom-up visual activation could still be detected and did not differ between patients and controls. By contrast, under focused top-down attention, a major impairment was observed: in patients, contrary to controls, the late non-linear ignition associated with the P3 component was reduced. Interestingly, the patients showed an essentially normal attentional amplification of the P1 and N2 components. These results suggest that some but not all top-down attentional amplification processes are impaired in schizophrenia, while bottom-up processing seems to be preserved. Keywords: Attention, Psychosis, Visual awareness, Masking, Top-down, Bottom-up

  7. Rapid, simple and direct detection of Meloidogyne hapla from infected root galls using loop-mediated isothermal amplification combined with FTA technology

    OpenAIRE

    Peng, Huan; Long, Haibo; Huang, Wenkun; Liu, Jing; Cui, Jiangkuan; Kong, Lingan; Hu, Xianqi; Gu, Jianfeng; Peng, Deliang

    2017-01-01

    The northern root-knot nematode (Meloidogyne hapla) is a damaging nematode that has caused serious economic losses worldwide. In the present study, a sensitive, simple and rapid method was developed for detection of M. hapla in infested plant roots by combining a Flinders Technology Associates (FTA) card with loop-mediated isothermal amplification (LAMP). The specific primers of LAMP were designed based on the distinction of internal transcribed spacer (ITS) sequences between M. hapla and oth...

  8. Molecular identification of Clonorchis sinensis and discrimination with other opisthorchid liver fluke species using Multiple Ligation-dependent Probe Amplification (MLPA).

    OpenAIRE

    Sun, J.; Xu, J.; Liang, P.; Mao, Q.; Huang, Y.; Lu, X.; Deng, C.; Liang, C.; de Hoog, G.S.; Yu, X.

    2011-01-01

    Background Infections with the opisthorchid liver flukes Clonorchis sinensis, Opisthorchis viverrini, and O. felineus cause severe health problems globally, particularly in Southeast Asia. Early identification of the infection is essential to provide timely and appropriate chemotherapy to patients. Results In this study we evaluate a PCR-based molecular identification method, Multiplex Ligation-dependent Probe Amplification (MLPA), which allows rapid and specific detection of single nucleotid...

  9. Clinical characteristics and outcome of patients with neuroblastoma presenting genomic amplification of loci other than MYCN.

    Directory of Open Access Journals (Sweden)

    Anne Guimier

    Full Text Available Somatically acquired genomic alterations with MYCN amplification (MNA are key features of neuroblastoma (NB, the most common extra-cranial malignant tumour of childhood. Little is known about the frequency, clinical characteristics and outcome of NBs harbouring genomic amplification(s distinct from MYCN.Genomic profiles of 1100 NBs from French centres studied by array-CGH were re-examined specifically to identify regional amplifications. Patients were included if amplifications distinct from the MYCN locus were seen. A subset of NBs treated at Institut Curie and harbouring MNA as determined by array-CGH without other amplification was also studied. Clinical and histology data were retrospectively collected.In total, 56 patients were included and categorised into 3 groups. Group 1 (n = 8 presented regional amplification(s without MNA. Locus 12q13-14 was a recurrent amplified region (4/8 cases. This group was heterogeneous in terms of INSS stages, primary localisations and histology, with atypical clinical features. Group 2 (n = 26 had MNA as well as other regional amplifications. These patients shared clinical features of those of a group of NBs MYCN amplified (Group 3, n = 22. Overall survival for group 1 was better than that of groups 2 and 3 (5 year OS: 87.5%±11% vs 34.9%±7%, log-rank p<0.05.NBs harbouring regional amplification(s without MNA are rare and seem to show atypical features in clinical presentation and genomic profile. Further high resolution genetic explorations are justified in this heterogeneous group, especially when considering these alterations as predictive markers for targeted therapy.

  10. Clinical Characteristics and Outcome of Patients with Neuroblastoma Presenting Genomic Amplification of Loci Other than MYCN

    Science.gov (United States)

    Guimier, Anne; Ferrand, Sandrine; Pierron, Gaëlle; Couturier, Jérôme; Janoueix-Lerosey, Isabelle; Combaret, Valérie; Mosseri, Véronique; Thebaud, Estelle; Gambart, Marion; Plantaz, Dominique; Marabelle, Aurélien; Coze, Carole; Rialland, Xavier; Fasola, Sylvie; Lapouble, Eve; Fréneaux, Paul; Peuchmaur, Michel; Michon, Jean; Delattre, Olivier; Schleiermacher, Gudrun

    2014-01-01

    Background Somatically acquired genomic alterations with MYCN amplification (MNA) are key features of neuroblastoma (NB), the most common extra-cranial malignant tumour of childhood. Little is known about the frequency, clinical characteristics and outcome of NBs harbouring genomic amplification(s) distinct from MYCN. Methods Genomic profiles of 1100 NBs from French centres studied by array-CGH were re-examined specifically to identify regional amplifications. Patients were included if amplifications distinct from the MYCN locus were seen. A subset of NBs treated at Institut Curie and harbouring MNA as determined by array-CGH without other amplification was also studied. Clinical and histology data were retrospectively collected. Results In total, 56 patients were included and categorised into 3 groups. Group 1 (n = 8) presented regional amplification(s) without MNA. Locus 12q13-14 was a recurrent amplified region (4/8 cases). This group was heterogeneous in terms of INSS stages, primary localisations and histology, with atypical clinical features. Group 2 (n = 26) had MNA as well as other regional amplifications. These patients shared clinical features of those of a group of NBs MYCN amplified (Group 3, n = 22). Overall survival for group 1 was better than that of groups 2 and 3 (5 year OS: 87.5%±11% vs 34.9%±7%, log-rank p<0.05). Conclusion NBs harbouring regional amplification(s) without MNA are rare and seem to show atypical features in clinical presentation and genomic profile. Further high resolution genetic explorations are justified in this heterogeneous group, especially when considering these alterations as predictive markers for targeted therapy. PMID:25013904

  11. Disabilities caused by unstable mutations in Costa Rica

    OpenAIRE

    Morales Montero, Fernando; Cuenca Berger, Patricia; Castro Volio, Isabel

    2004-01-01

    Myotonic dystrophy and fragile X syndrome are two genetically determined relatively common disabilities. Both are examples of a new type of mutation mechanism called unstable or dynamic mutations, triple repeats expansions or DNA amplification. Fragile X syndrome is recognized as the main cause of hereditary mental retardation and myotonic dystrophy is considered the most common muscular dystrophy of adults. This is a prospective non randomized study of clinically affected people,...

  12. Social Amplification of Risk and Crisis Communication Planing - Case Study

    Science.gov (United States)

    Stanciugelu, I.; Frunzaru, V.; Armas, I.; Duntzer, A.; Stan, S.

    2012-04-01

    Risk management has become a dominant concern of public policy and the ability of government to anticipate the strength and focus of public concerns remains weak. The Social Amplification of Risk Framework (SARF) was designed to assist in this endeavor. It aims to facilitate a greater understanding of the social processes that can mediate between a hazard event and its consequences. SARF identifies categories of mediator/moderator that intervene between risk event and its consequences and suggests a causal and temporal sequence in which they act. Information flows first through various sources and then channels, triggering social stations of amplification, initiating individual station of amplification and precipitating behavioral reactions. The International Risk Governance Council Framework is an interdisciplinary and multilevel approach, linking risk management and risk assessment sphere through communication. This study aims to identify categories of mediator/moderator that intervene between the risk event and its consequences, using a survey on earthquake risk perception addressing population of Bucharest city. Romania has a unique seismic profile in Europe, being the country with the biggest surface affected in case of a serious earthquake. Considering the development of the urban area that took place in the last two decades and the growing number of inhabitants, Bucharest is the largest city in Romania and is exposed to extensive damages in case of an earthquake. The sociological survey has been conducted in December 2009 on a representative sample of the Bucharest population aged 18 and over (N=1376) using one stage sampling design. We used a stratified sample method shearing the investigated populations in six layers according to the six sectors of Bucharest. The respondents were selected using random digit dialling method (RDD) and the questionnaires were administered by research staff with computer assisted telephone interviewing method (CATI). The

  13. Strand Invasion Based Amplification (SIBA®): a novel isothermal DNA amplification technology demonstrating high specificity and sensitivity for a single molecule of target analyte.

    Science.gov (United States)

    Hoser, Mark J; Mansukoski, Hannu K; Morrical, Scott W; Eboigbodin, Kevin E

    2014-01-01

    Isothermal nucleic acid amplification technologies offer significant advantages over polymerase chain reaction (PCR) in that they do not require thermal cycling or sophisticated laboratory equipment. However, non-target-dependent amplification has limited the sensitivity of isothermal technologies and complex probes are usually required to distinguish between non-specific and target-dependent amplification. Here, we report a novel isothermal nucleic acid amplification technology, Strand Invasion Based Amplification (SIBA). SIBA technology is resistant to non-specific amplification, is able to detect a single molecule of target analyte, and does not require target-specific probes. The technology relies on the recombinase-dependent insertion of an invasion oligonucleotide (IO) into the double-stranded target nucleic acid. The duplex regions peripheral to the IO insertion site dissociate, thereby enabling target-specific primers to bind. A polymerase then extends the primers onto the target nucleic acid leading to exponential amplification of the target. The primers are not substrates for the recombinase and are, therefore unable to extend the target template in the absence of the IO. The inclusion of 2'-O-methyl RNA to the IO ensures that it is not extendible and that it does not take part in the extension of the target template. These characteristics ensure that the technology is resistant to non-specific amplification since primer dimers or mis-priming are unable to exponentially amplify. Consequently, SIBA is highly specific and able to distinguish closely-related species with single molecule sensitivity in the absence of complex probes or sophisticated laboratory equipment. Here, we describe this technology in detail and demonstrate its use for the detection of Salmonella.

  14. Strand Invasion Based Amplification (SIBA®: a novel isothermal DNA amplification technology demonstrating high specificity and sensitivity for a single molecule of target analyte.

    Directory of Open Access Journals (Sweden)

    Mark J Hoser

    Full Text Available Isothermal nucleic acid amplification technologies offer significant advantages over polymerase chain reaction (PCR in that they do not require thermal cycling or sophisticated laboratory equipment. However, non-target-dependent amplification has limited the sensitivity of isothermal technologies and complex probes are usually required to distinguish between non-specific and target-dependent amplification. Here, we report a novel isothermal nucleic acid amplification technology, Strand Invasion Based Amplification (SIBA. SIBA technology is resistant to non-specific amplification, is able to detect a single molecule of target analyte, and does not require target-specific probes. The technology relies on the recombinase-dependent insertion of an invasion oligonucleotide (IO into the double-stranded target nucleic acid. The duplex regions peripheral to the IO insertion site dissociate, thereby enabling target-specific primers to bind. A polymerase then extends the primers onto the target nucleic acid leading to exponential amplification of the target. The primers are not substrates for the recombinase and are, therefore unable to extend the target template in the absence of the IO. The inclusion of 2'-O-methyl RNA to the IO ensures that it is not extendible and that it does not take part in the extension of the target template. These characteristics ensure that the technology is resistant to non-specific amplification since primer dimers or mis-priming are unable to exponentially amplify. Consequently, SIBA is highly specific and able to distinguish closely-related species with single molecule sensitivity in the absence of complex probes or sophisticated laboratory equipment. Here, we describe this technology in detail and demonstrate its use for the detection of Salmonella.

  15. Development of Loop-Mediated Isothermal Amplification for Detection of Leifsonia xyli subsp. xyli in Sugarcane

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2013-01-01

    Full Text Available Ratoon stunt, caused by the xylem-limited coryneform bacterium Leifsonia xyli subsp. xyli (Lxx, is a deep bacteriosis and prevalent in most of sugarcane-producing countries. Based on loop-mediated isothermal amplification (LAMP, we developed a method for detecting Lxx. The major advantages of the LAMP method are visual judgment by color and time saving with only 60 min for identification of Lxx and without the need for costly PCR apparatus and gel scanner. In the present study, positive and negative samples detected by the LAMP method were clearly distinguishable. When total DNA extracted from internode juice was used as the template, the sensitivity of LAMP was 10 times higher than that of the conventional PCR detection. The LAMP assay is a highly specific, rapid, and sensitive method for the diagnosis of ratoon stunt caused by Lxx in sugarcane. This is the first report of LAMP-based assay for the detection of Lxx in sugarcane.

  16. Dihydrofolate reductase amplification and sensitization to methotrexate of methotrexate-resistant colon cancer cells

    DEFF Research Database (Denmark)

    Morales Torres, Christina; García, Maria J; Ribas, Maria

    2009-01-01

    Gene amplification is one of the most frequent manifestations of genomic instability in human tumors and plays an important role in tumor progression and acquisition of drug resistance. To better understand the factors involved in acquired resistance to cytotoxic drugs via gene amplification, we ...

  17. 78 FR 66940 - Regulatory Requirements for Hearing Aid Devices and Personal Sound Amplification Products; Draft...

    Science.gov (United States)

    2013-11-07

    ... for such products. These inconsistent interpretations of the definitions may inadvertently result in... amplification products (PSAPs), as well as the regulatory controls that apply to each. This draft guidance is... of clarity regarding how the Agency defines a hearing aid versus a personal sound amplification...

  18. Evaluation of current state of amplification-based DDoS attacks

    NARCIS (Netherlands)

    Bohte, Edgar; Stamatogiannakis, Manolis; Bos, Herbert

    2018-01-01

    Amplification-based DDoS attacks are still a big threat to the availability of the internet. In quite some time there is no new paper published that gave an update on the current state of amplification DDoS attacks, taken into consideration it was a huge problem a few years ago. We performed

  19. An ultrasensitive colorimeter assay strategy for p53 mutation assisted by nicking endonuclease signal amplification.

    Science.gov (United States)

    Lin, Zhenyu; Yang, Weiqiang; Zhang, Guiyun; Liu, Qida; Qiu, Bin; Cai, Zongwei; Chen, Guonan

    2011-08-28

    A novel catalytic colorimetric assay assisted by nicking endonuclease signal amplification (NESA) was developed. With the signal amplification, the detection limit of the p53 target gene can be as low as 1 pM, which is nearly 5 orders of magnitude lower than that of other previously reported colorimetric DNA detection strategies based on catalytic DNAzyme.

  20. Signal amplification of microRNAs with modified strand displacement-based cycling probe technology.

    Science.gov (United States)

    Jia, Huning; Bu, Ying; Zou, Bingjie; Wang, Jianping; Kumar, Shalen; Pitman, Janet L; Zhou, Guohua; Song, Qinxin

    2016-10-24

    Micro ribose nucleic acids (miRNAs) play an important role in biological processes such as cell differentiation, proliferation and apoptosis. Therefore, miRNAs are potentially a powerful marker for monitoring cancer and diagnosis. Here, we present sensitive signal amplification for miRNAs based on modified cycling probe technology with strand displacement amplification. miRNA was captured by the template coupled with beads, and then the first cycle based on SDA was repeatedly extended to the nicking end, which was produced by the extension reaction of miRNA. The products generated by SDA are captured by a molecular beacon (MB), which is designed to initiate the second amplification cycle, with a similar principle to the cycling probe technology (CPT), which is based on repeated digestion of the DNA-RNA hybrid by the RNase H. After one sample enrichment and two steps of signal amplification, 0.1 pM of let-7a can be detected. The miRNA assay exhibits a great dynamic range of over 100 orders of magnitude and high specificity to clearly discriminate a single base difference in miRNA sequences. This isothermal amplification does not require any special temperature control instrument. The assay is also about signal amplification rather than template amplification, therefore minimising contamination issues. In addition, there is no need for the reverse transcription (RT) process. Thus the amplification is suitable for miRNA detection.

  1. Amplification of North American Red Oak Microsatellite Markers in European White Oaks and Chinese Chestnut

    Science.gov (United States)

    P. R. Aldrich; M. Jagtap; C. H. Michler; J. Romero-Severson

    2003-01-01

    We examined the cross-species amplification success of thirty microsatellite markers developed from North American northern red oak (Quercus rubra) in other members of the family Fagaceae. Sixteen of these markers are newly developed and we report primer sequences and amplification conditions here. Twelve of the thirty (40.0%) red oak markers...

  2. The effect of whole genome amplification on samples originating from more than one donor

    DEFF Research Database (Denmark)

    Thacker, C.R.; Balogh, M.K.; Børsting, Claus

    2006-01-01

    In this study, the GenomiPhi(TM) DNA Amplification Kit (Amersham Biosciences) was used to investigate the potential of whole genome amplification (WGA) when considering samples originating from more than one donor. DNA was extracted from blood samples, quantified and normalised before being mixed...

  3. Optimization of an Optical Parametric Chirped Pulse Amplification System for the OMEGA EP Laser System

    International Nuclear Information System (INIS)

    Begishev, I.; Bagnoud, V.; Guardalben, M.; Waxer, L.; Puth, J.; Zuegel, J.

    2003-01-01

    OAK B204 We report on the experimental achievements of the optical parametric chirped-pulse amplification (OPCPA) system, including 29% pump-to-signal conversion efficiency and 107 gain using two LBO crystals configured as a single amplification stage. Temporal and spatial shaping of the pump laser pulse is required to achieve both high-gain and high-conversion efficiency

  4. Polymorphic microsatellites developed by cross-species amplifications in common pheasant breeds

    NARCIS (Netherlands)

    Baratti, M.; Alberti, A.; Groenen, M.A.M.; Veenendaal, T.; Fulgheri, F.D.

    2001-01-01

    Genetic variability was analysed in two common breeds of pheasant (Phasianus colchicus L. 1758) by means of cross-species amplifications of microsatellite loci: 154 chicken, Gallus gallus and 32 turkey, Meleagris gallopavo, primers were tested for amplification of pheasant DNA. Thirty-six primers

  5. The Media and Genetically Modified Foods : Evidence in Support of Social Amplification of Risk

    NARCIS (Netherlands)

    Frewer, L.J.; Miles, S.; Marsh, R.

    2002-01-01

    Empirical examinations of the "social amplification of risk" framework are rare, partly because of the difficulties in predicting when conditions likely to result in amplification effects will occur. This means that it is difficult to examine changes in risk perception that are contemporaneous with

  6. Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

    Science.gov (United States)

    Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

    2017-10-01

    The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

  7. Quantification of HER2 autoantibodies in the amplification phenomenon of HER2 in breast cancer

    DEFF Research Database (Denmark)

    Lauterlein, Jens-Jacob L; Petersen, Eva R B; Olsen, Dorte Aa

    2011-01-01

    Gene amplification of HER2 (human epidermal growth factor receptor 2) is a well-known phenomenon in various cancers. However, little is known about the mechanism of the gene amplification phenomenon itself. Autoantibodies to cellular receptors have been described in several cancer types. We hypot...

  8. Hydromagnetic instabilities and magnetic field amplification in core collapse supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Cerda-Duran, P; Obergaulinger, M; Mueller, E [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-st. 1, 85748 Garching (Germany); Aloy, M A; Font, J A, E-mail: cerda@mpa-garching.mpg.de [Departamento de Astronomia y Astrofisica, Universidad de Valencia, 46100 Burjassot, Valencia (Spain)

    2011-09-22

    Some of the most violent events in the universe, the gamma ray burst, could be related to the gravitational collapse of massive stellar cores. The recent association of long GRBs to some class of type Ic supernova seems to support this view. In such scenario fast rotation, strong magnetic fields and general relativistic effects are key ingredients. It is thus important to understand the mechanism that amplifies the magnetic field under that conditions. I present global simulations of the magneto-rotational collapse of stellar cores in general relativity and semi-global simulations of hydromagnetic instabilities under core collapse conditions. I discuss effect of the magneto-rotational instability and the magnetic field amplification during the collapse, the uncertainties in this process and the dynamical effects in the supernova explosion.

  9. Scintillation light detectors with Neganov-Luke amplification

    Energy Technology Data Exchange (ETDEWEB)

    Isaila, C. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany)]. E-mail: cisaila@ph.tum.de; Boslau, O. [Ketek GmbH, Gustav Heinemann Ring 125, 81739 Munich (Germany); Coppi, C. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Feilitzsch, F. von [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Goldstrass, P. [Ketek GmbH, Gustav Heinemann Ring 125, 81739 Munich (Germany); Jagemann, T. [Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 14, 72076 Tuebingen (Germany); Jochum, J. [Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 14, 72076 Tuebingen (Germany); Kemmer, J. [Ketek GmbH, Gustav Heinemann Ring 125, 81739 Munich (Germany); Lachenmaier, T. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Lanfranchi, J.-C. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Pahlke, A. [Ketek GmbH, Gustav Heinemann Ring 125, 81739 Munich (Germany); Potzel, W. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Rau, W. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Stark, M. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); Wernicke, D. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany); VeriCold Technologies GmbH, Bahnhofstrasse 21, 85737 Ismaning (Germany); Westphal, W. [Physik Department E15, Technische Universitaet Muenchen, James Franck Strasse, 85748 Garching (Germany)

    2006-04-15

    For an active suppression of the gamma and electron background in the Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) dark matter experiment both phonons and scintillation light generated in a CaWO{sub 4} crystal are detected simultaneously. The phonon signal is read out by a transition edge sensor (TES) on the CaWO{sub 4} crystal. For light detection a silicon absorber equipped with a TES is employed. An efficient background discrimination requires very sensitive light detectors. The threshold can be improved by applying an electric field to the silicon crystal leading to an amplification of the thermal signal due to the Neganov-Luke effect. Measurements showing the improved sensitivity of the light detectors as well as future steps for reducing the observed extra noise will be presented.

  10. Gelation induced supramolecular chirality: chirality transfer, amplification and application.

    Science.gov (United States)

    Duan, Pengfei; Cao, Hai; Zhang, Li; Liu, Minghua

    2014-08-14

    Supramolecular chirality defines chirality at the supramolecular level, and is generated from the spatial arrangement of component molecules assembling through non-covalent interactions such as hydrogen bonding, van der Waals interactions, π-π stacking, hydrophobic interactions and so on. During the formation of low molecular weight gels (LMWGs), one kind of fascinating soft material, one frequently encounters the phenomenon of chirality as well as chiral nanostructures, either from chiral gelators or even achiral gelators. A view of gelation-induced supramolecular chirality will be very helpful to understand the self-assembly process of the gelator molecules as well as the chiral structures, the regulation of the chirality in the gels and the development of the "smart" chiral materials such as chiroptical devices, catalysts and chiral sensors. It necessitates fundamental understanding of chirality transfer and amplification in these supramolecular systems. In this review, recent progress in gelation-induced supramolecular chirality is discussed.

  11. Organo-erbium systems for optical amplification at telecommunications wavelengths.

    Science.gov (United States)

    Ye, H Q; Li, Z; Peng, Y; Wang, C C; Li, T Y; Zheng, Y X; Sapelkin, A; Adamopoulos, G; Hernández, I; Wyatt, P B; Gillin, W P

    2014-04-01

    Modern telecommunications rely on the transmission and manipulation of optical signals. Optical amplification plays a vital part in this technology, as all components in a real telecommunications system produce some loss. The two main issues with present amplifiers, which rely on erbium ions in a glass matrix, are the difficulty in integration onto a single substrate and the need of high pump power densities to produce gain. Here we show a potential organic optical amplifier material that demonstrates population inversion when pumped from above using low-power visible light. This system is integrated into an organic light-emitting diode demonstrating that electrical pumping can be achieved. This opens the possibility of direct electrically driven optical amplifiers and optical circuits. Our results provide an alternative approach to producing low-cost integrated optics that is compatible with existing silicon photonics and a different route to an effective integrated optics technology.

  12. Signal amplification for impedimetric genosensing using gold-streptavidin nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bonanni, A.; Esplandiu, M.J. [Sensors and Biosensors Group, Department of Chemistry, Universitat Autonoma de Barcelona, Edifici Cn, 08193 Bellaterra, Barcelona (Spain); Valle, M. del [Sensors and Biosensors Group, Department of Chemistry, Universitat Autonoma de Barcelona, Edifici Cn, 08193 Bellaterra, Barcelona (Spain)], E-mail: manel.delvalle@uab.es

    2008-04-20

    Streptavidin-coated gold nanoparticles (strept-AuNPs) were used in this work to amplify the impedimetric signal generated in a biosensor detecting the DNA hybridization event. Probe oligomer was adsorbed onto a graphite epoxy composite (GEC) electrode surface and the impedance measurement was performed in a solution containing the redox marker ferrocyanide/ferricyanide. The biotinylated complementary oligomer was used as target. The change of interfacial charge transfer resistance (R{sub ct}), experimented by the redox marker, was recorded to confirm the hybrid formation. The addition of strept-AuNPs, binding to the target due to the strong streptavidin-biotin interaction, led to a further increment of R{sub ct} thus obtaining significant signal amplification. Strept-AuNPs on the electrode surface were observed by scanning electron microscopy (SEM) after silver enhancement treatment. A competitive binding assay was also performed using unlabelled DNA target to demonstrate its applicability to real sample analysis.

  13. Near quantum limited amplification from inelastic Cooper-pair tunneling

    Science.gov (United States)

    Hofheinz, Max; Jebari, Salha; Blanchet, Florian; Grimm, Alexander; Hazra, Dibyendu; Albert, Romain; Portier, Fabien

    Josephson parametric amplifiers approach quantum-limited noise performance but require strong external microwave pump tones which make them more difficult to use than DC powered amplifiers: The pump tone can affect the device under test and requires expensive room-temperature equipment. Inelastic Cooper pair tunneling processes through a small DC voltage-biased Josephson junction, where a tunneling Cooper pair dissipates its energy 2 eV in the form of two photons are reminiscent of parametric down conversion. We show that these processes can be used to provide amplification near the quantum limit without external microwave pump tone. We explain the measured gain and noise based on the P (E) theory of inelastic Cooper pair tunneling and general fluctuation-dissipation relations.

  14. Amplification of large-scale magnetic field in nonhelical magnetohydrodynamics

    KAUST Repository

    Kumar, Rohit

    2017-08-11

    It is typically assumed that the kinetic and magnetic helicities play a crucial role in the growth of large-scale dynamo. In this paper, we demonstrate that helicity is not essential for the amplification of large-scale magnetic field. For this purpose, we perform nonhelical magnetohydrodynamic (MHD) simulation, and show that the large-scale magnetic field can grow in nonhelical MHD when random external forcing is employed at scale 1/10 the box size. The energy fluxes and shell-to-shell transfer rates computed using the numerical data show that the large-scale magnetic energy grows due to the energy transfers from the velocity field at the forcing scales.

  15. Scintillation light detectors with Neganov-Luke amplification

    International Nuclear Information System (INIS)

    Isaila, C.; Boslau, O.; Coppi, C.; Feilitzsch, F. von; Goldstrass, P.; Jagemann, T.; Jochum, J.; Kemmer, J.; Lachenmaier, T.; Lanfranchi, J.-C.; Pahlke, A.; Potzel, W.; Rau, W.; Stark, M.; Wernicke, D.; Westphal, W.

    2006-01-01

    For an active suppression of the gamma and electron background in the Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) dark matter experiment both phonons and scintillation light generated in a CaWO 4 crystal are detected simultaneously. The phonon signal is read out by a transition edge sensor (TES) on the CaWO 4 crystal. For light detection a silicon absorber equipped with a TES is employed. An efficient background discrimination requires very sensitive light detectors. The threshold can be improved by applying an electric field to the silicon crystal leading to an amplification of the thermal signal due to the Neganov-Luke effect. Measurements showing the improved sensitivity of the light detectors as well as future steps for reducing the observed extra noise will be presented

  16. Multiplex amplification of large sets of human exons.

    Science.gov (United States)

    Porreca, Gregory J; Zhang, Kun; Li, Jin Billy; Xie, Bin; Austin, Derek; Vassallo, Sara L; LeProust, Emily M; Peck, Bill J; Emig, Christopher J; Dahl, Fredrik; Gao, Yuan; Church, George M; Shendure, Jay

    2007-11-01

    A new generation of technologies is poised to reduce DNA sequencing costs by several orders of magnitude. But our ability to fully leverage the power of these technologies is crippled by the absence of suitable 'front-end' methods for isolating complex subsets of a mammalian genome at a scale that matches the throughput at which these platforms will routinely operate. We show that targeting oligonucleotides released from programmable microarrays can be used to capture and amplify approximately 10,000 human exons in a single multiplex reaction. Additionally, we show integration of this protocol with ultra-high-throughput sequencing for targeted variation discovery. Although the multiplex capture reaction is highly specific, we found that nonuniform capture is a key issue that will need to be resolved by additional optimization. We anticipate that highly multiplexed methods for targeted amplification will enable the comprehensive resequencing of human exons at a fraction of the cost of whole-genome resequencing.

  17. Signal amplification and Pierce's instability in convergent particle beams

    International Nuclear Information System (INIS)

    Gnavi, G.; Gratton, F.T.

    1988-01-01

    Relativistic electron beams flowing between cylindrical and spherical electrodes (or solid angles sections of electrodes with these geometries) are studied. The beams are focused through the axis in the cylindrical case or through the center when spherical electrodes are considered. It is assumed that the external electrode is part of a device which accelerates the particles, the inner electrode is passive and removes the beams from the system. Electrons move by inertia in the interelectrode space, neutralized by an ion background. Properties of radial, small amplitude, perturbations are analyzed theoretically. Previous analyses of counterstreaming beams indicated that convergence modifies considerably the oscillations spectrum. Here, results on the amplification of signals when a beam is modulated at the external electrode are reported. Then, conditions for the instability of a beam when it flows through grounded electrodes (Pierce's instability of only one beam) are examined

  18. Cognitive and affective matching effects in persuasion: an amplification perspective.

    Science.gov (United States)

    Clarkson, Joshua J; Tormala, Zakary L; Rucker, Derek D

    2011-11-01

    Past research suggests that cognitive and affective attitudes are more open to change toward cognitive and affective (i.e., matched) persuasive attacks, respectively. The present research investigates how attitude certainty influences this openness. Although an extensive literature suggests that certainty generally reduces an attitude's openness to change, the authors explore the possibility that certainty might increase an attitude's openness to change in the context of affective or cognitive appeals. Based on the recently proposed amplification hypothesis, the authors posit that high (vs. low) attitude certainty will boost the resistance of attitudes to mismatched attacks (e.g., affective attitudes attacked by cognitive messages) but boost the openness of attitudes to matched attacks (e.g., affective attitudes attacked by affective messages). Two experiments provide support for this hypothesis. Implications for increasing the openness of attitudes to both matched and mismatched attacks are discussed.

  19. Phase Sensitive Amplification using Parametric Processes in Optical Fibers

    DEFF Research Database (Denmark)

    Kang, Ning

    . Further, phase sensitive parametric processes in a nano-engineered silicon waveguide have been measured experimentally for the first time. Numerical optimizations show that with reduced waveguide propagation loss and reduced carrier life time, larger signal phase sensitive extinction ratio is achievable......Phase sensitive amplification using the parametric processes in fiber has the potential of delivering high gain and broadband operation with ultralow noise. It is able to regenerate both amplitude and phase modulated signals, simultaneously, with the appropriate design. This thesis concerns...... types. The regeneration capability of PSAs on phase encoded signal in an optical link has been optimized. Flat-top phase sensitive profile has been synthesized. It is able to provide simultaneous amplitude and phase noise squeezing, with enhanced phase noise margin compared to conventional designs...

  20. Recombinase Polymerase Amplification Assay for Rapid Diagnostics of Dengue Infection.

    Directory of Open Access Journals (Sweden)

    Ahmed Abd El Wahed

    Full Text Available Over 2.5 billion people are exposed to the risk of contracting dengue fever (DF. Early diagnosis of DF helps to diminish its burden on public health. Real-time reverse transcription polymerase amplification assays (RT-PCR are the standard method for molecular detection of the dengue virus (DENV. Real-time RT-PCR analysis is not suitable for on-site screening since mobile devices are large, expensive, and complex. In this study, two RT-recombinase polymerase amplification (RT-RPA assays were developed to detect DENV1-4.Using two quantitative RNA molecular standards, the analytical sensitivity of a RT-RPA targeting the 3´non-translated region of DENV1-4 was found to range from 14 (DENV4 to 241 (DENV1-3 RNA molecules detected. The assay was specific and did not cross detect other Flaviviruses. The RT-RPA assay was tested in a mobile laboratory combining magnetic-bead based total nucleic acid extraction and a portable detection device in Kedougou (Senegal and in Bangkok (Thailand. In Kedougou, the RT-RPA was operated at an ambient temperature of 38 °C with auxiliary electricity tapped from a motor vehicle and yielded a clinical sensitivity and specificity of 98% (n=31 and 100% (n=23, respectively. While in the field trial in Bangkok, the clinical sensitivity and specificity were 72% (n=90 and 100%(n=41, respectively.During the first 5 days of infection, the developed DENV1-4 RT-RPA assays constitute a suitable accurate and rapid assay for DENV diagnosis. Moreover, the use of a portable fluorescence-reading device broadens its application potential to the point-of-care for outbreak investigations.

  1. Integrated Microfluidic Nucleic Acid Isolation, Isothermal Amplification, and Amplicon Quantification

    Directory of Open Access Journals (Sweden)

    Michael G. Mauk

    2015-10-01

    Full Text Available Microfluidic components and systems for rapid (<60 min, low-cost, convenient, field-deployable sequence-specific nucleic acid-based amplification tests (NAATs are described. A microfluidic point-of-care (POC diagnostics test to quantify HIV viral load from blood samples serves as a representative and instructive example to discuss the technical issues and capabilities of “lab on a chip” NAAT devices. A portable, miniaturized POC NAAT with performance comparable to conventional PCR (polymerase-chain reaction-based tests in clinical laboratories can be realized with a disposable, palm-sized, plastic microfluidic chip in which: (1 nucleic acids (NAs are extracted from relatively large (~mL volume sample lysates using an embedded porous silica glass fiber or cellulose binding phase (“membrane” to capture sample NAs in a flow-through, filtration mode; (2 NAs captured on the membrane are isothermally (~65 °C amplified; (3 amplicon production is monitored by real-time fluorescence detection, such as with a smartphone CCD camera serving as a low-cost detector; and (4 paraffin-encapsulated, lyophilized reagents for temperature-activated release are pre-stored in the chip. Limits of Detection (LOD better than 103 virons/sample can be achieved. A modified chip with conduits hosting a diffusion-mode amplification process provides a simple visual indicator to readily quantify sample NA template. In addition, a companion microfluidic device for extracting plasma from whole blood without a centrifuge, generating cell-free plasma for chip-based molecular diagnostics, is described. Extensions to a myriad of related applications including, for example, food testing, cancer screening, and insect genotyping are briefly surveyed.

  2. Method for decoupling error correction from privacy amplification

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Hoi-Kwong [Department of Electrical and Computer Engineering and Department of Physics, University of Toronto, 10 King' s College Road, Toronto, Ontario, Canada, M5S 3G4 (Canada)

    2003-04-01

    In a standard quantum key distribution (QKD) scheme such as BB84, two procedures, error correction and privacy amplification, are applied to extract a final secure key from a raw key generated from quantum transmission. To simplify the study of protocols, it is commonly assumed that the two procedures can be decoupled from each other. While such a decoupling assumption may be valid for individual attacks, it is actually unproven in the context of ultimate or unconditional security, which is the Holy Grail of quantum cryptography. In particular, this means that the application of standard efficient two-way error-correction protocols like Cascade is not proven to be unconditionally secure. Here, I provide the first proof of such a decoupling principle in the context of unconditional security. The method requires Alice and Bob to share some initial secret string and use it to encrypt their communications in the error correction stage using one-time-pad encryption. Consequently, I prove the unconditional security of the interactive Cascade protocol proposed by Brassard and Salvail for error correction and modified by one-time-pad encryption of the error syndrome, followed by the random matrix protocol for privacy amplification. This is an efficient protocol in terms of both computational power and key generation rate. My proof uses the entanglement purification approach to security proofs of QKD. The proof applies to all adaptive symmetric methods for error correction, which cover all existing methods proposed for BB84. In terms of the net key generation rate, the new method is as efficient as the standard Shor-Preskill proof.

  3. Comparison of bulk Micromegas with different amplification gaps

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Purba, E-mail: purba.bhattacharya@saha.ac.in [Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Bhattacharya, Sudeb [Emeritus Scientist (CSIR), Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Majumdar, Nayana; Mukhopadhyay, Supratik; Sarkar, Sandip [Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Colas, Paul; Attie, David [DSM/IRFU, CEA/Saclay, F-91191 Gif-sur-Yvette CEDEX (France)

    2013-12-21

    The bulk Micromegas detector is considered to be a promising candidate for building TPCs for several future experiments including the projected linear collider. The standard bulk with a spacing of 128μm has already established itself as a good choice for its performances in terms of gas gain uniformity, energy and space point resolution, and its capability to efficiently pave large readout surfaces with minimum dead zone. The present work involves the comparison of this standard bulk with a relatively less used bulk Micromegas detector having a larger amplification gap of 192μm. Detector gain, energy resolution and electron transparency of these Micromegas have been measured under different conditions in various Argon-based gas mixtures to evaluate their performance. These measured characteristics have also been compared in detail to numerical simulations using the Garfield framework that combines packages such as neBEM, Magboltz and Heed. Further, we have carried out another numerical study to determine the effect of dielectric spacers on different detector features. A comprehensive comparison of the two detectors has been presented and analyzed in this work. -- Highlights: •We present a comparative study between bulk Micromegas having different amplification gaps. •Various detector characteristics such as gain, electron transparency, energy resolution have been measured experimentally. •Successful comparisons of these measured data with the simulation results indicate that the device physics is quite well understood. •A numerical study to determine the effect of dielectric spacers on different detect or features has been carried out.

  4. Mechanism of chimera formation during the Multiple Displacement Amplification reaction

    Directory of Open Access Journals (Sweden)

    Stockwell Timothy B

    2007-04-01

    Full Text Available Abstract Background Multiple Displacement Amplification (MDA is a method used for amplifying limiting DNA sources. The high molecular weight amplified DNA is ideal for DNA library construction. While this has enabled genomic sequencing from one or a few cells of unculturable microorganisms, the process is complicated by the tendency of MDA to generate chimeric DNA rearrangements in the amplified DNA. Determining the source of the DNA rearrangements would be an important step towards reducing or eliminating them. Results Here, we characterize the major types of chimeras formed by carrying out an MDA whole genome amplification from a single E. coli cell and sequencing by the 454 Life Sciences method. Analysis of 475 chimeras revealed the predominant reaction mechanisms that create the DNA rearrangements. The highly branched DNA synthesized in MDA can assume many alternative secondary structures. DNA strands extended on an initial template can be displaced becoming available to prime on a second template creating the chimeras. Evidence supports a model in which branch migration can displace 3'-ends freeing them to prime on the new templates. More than 85% of the resulting DNA rearrangements were inverted sequences with intervening deletions that the model predicts. Intramolecular rearrangements were favored, with displaced 3'-ends reannealing to single stranded 5'-strands contained within the same branched DNA molecule. In over 70% of the chimeric junctions, the 3' termini had initiated priming at complimentary sequences of 2–21 nucleotides (nts in the new templates. Conclusion Formation of chimeras is an important limitation to the MDA method, particularly for whole genome sequencing. Identification of the mechanism for chimera formation provides new insight into the MDA reaction and suggests methods to reduce chimeras. The 454 sequencing approach used here will provide a rapid method to assess the utility of reaction modifications.

  5. Method for decoupling error correction from privacy amplification

    International Nuclear Information System (INIS)

    Lo, Hoi-Kwong

    2003-01-01

    In a standard quantum key distribution (QKD) scheme such as BB84, two procedures, error correction and privacy amplification, are applied to extract a final secure key from a raw key generated from quantum transmission. To simplify the study of protocols, it is commonly assumed that the two procedures can be decoupled from each other. While such a decoupling assumption may be valid for individual attacks, it is actually unproven in the context of ultimate or unconditional security, which is the Holy Grail of quantum cryptography. In particular, this means that the application of standard efficient two-way error-correction protocols like Cascade is not proven to be unconditionally secure. Here, I provide the first proof of such a decoupling principle in the context of unconditional security. The method requires Alice and Bob to share some initial secret string and use it to encrypt their communications in the error correction stage using one-time-pad encryption. Consequently, I prove the unconditional security of the interactive Cascade protocol proposed by Brassard and Salvail for error correction and modified by one-time-pad encryption of the error syndrome, followed by the random matrix protocol for privacy amplification. This is an efficient protocol in terms of both computational power and key generation rate. My proof uses the entanglement purification approach to security proofs of QKD. The proof applies to all adaptive symmetric methods for error correction, which cover all existing methods proposed for BB84. In terms of the net key generation rate, the new method is as efficient as the standard Shor-Preskill proof

  6. Isothermal amplification detection of nucleic acids by a double-nicked beacon.

    Science.gov (United States)

    Shi, Chao; Zhou, Meiling; Pan, Mei; Zhong, Guilin; Ma, Cuiping

    2016-03-01

    Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Fast implementation of length-adaptive privacy amplification in quantum key distribution

    International Nuclear Information System (INIS)

    Zhang Chun-Mei; Li Mo; Huang Jing-Zheng; Li Hong-Wei; Li Fang-Yi; Wang Chuan; Yin Zhen-Qiang; Chen Wei; Han Zhen-Fu; Treeviriyanupab Patcharapong; Sripimanwat Keattisak

    2014-01-01

    Post-processing is indispensable in quantum key distribution (QKD), which is aimed at sharing secret keys between two distant parties. It mainly consists of key reconciliation and privacy amplification, which is used for sharing the same keys and for distilling unconditional secret keys. In this paper, we focus on speeding up the privacy amplification process by choosing a simple multiplicative universal class of hash functions. By constructing an optimal multiplication algorithm based on four basic multiplication algorithms, we give a fast software implementation of length-adaptive privacy amplification. “Length-adaptive” indicates that the implementation of privacy amplification automatically adapts to different lengths of input blocks. When the lengths of the input blocks are 1 Mbit and 10 Mbit, the speed of privacy amplification can be as fast as 14.86 Mbps and 10.88 Mbps, respectively. Thus, it is practical for GHz or even higher repetition frequency QKD systems. (general)

  8. Amplification of ABA biosynthesis and signaling through a positive feedback mechanism in seeds.

    Science.gov (United States)

    Nonogaki, Mariko; Sall, Khadidiatou; Nambara, Eiji; Nonogaki, Hiroyuki

    2014-05-01

    Abscisic acid is an essential hormone for seed dormancy. Our previous study using the plant gene switch system, a chemically induced gene expression system, demonstrated that induction of 9-cis-epoxycarotenoid dioxygenase (NCED), a rate-limiting ABA biosynthesis gene, was sufficient to suppress germination in imbibed Arabidopsis seeds. Here, we report development of an efficient experimental system that causes amplification of NCED expression during seed maturation. The system was created with a Triticum aestivum promoter containing ABA responsive elements (ABREs) and a Sorghum bicolor NCED to cause ABA-stimulated ABA biosynthesis and signaling, through a positive feedback mechanism. The chimeric gene pABRE:NCED enhanced NCED and ABF (ABRE-binding factor) expression in Arabidopsis Columbia-0 seeds, which caused 9- to 73-fold increases in ABA levels. The pABRE:NCED seeds exhibited unusually deep dormancy which lasted for more than 3 months. Interestingly, the amplified ABA pathways also caused enhanced expression of Arabidopsis NCED5, revealing the presence of positive feedback in the native system. These results demonstrated the robustness of positive feedback mechanisms and the significance of NCED expression, or single metabolic change, during seed maturation. The pABRE:NCED system provides an excellent experimental system producing dormant and non-dormant seeds of the same maternal origin, which differ only in zygotic ABA. The pABRE:NCED seeds contain a GFP marker which enables seed sorting between transgenic and null segregants and are ideal for comparative analysis. In addition to its utility in basic research, the system can also be applied to prevention of pre-harvest sprouting during crop production, and therefore contributes to translational biology. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  9. pH responsive label-assisted click chemistry triggered sensitivity amplification for ultrasensitive electrochemical detection of carbohydrate antigen 24-2.

    Science.gov (United States)

    Zheng, Yun; Zhao, Lihua; Ma, Zhanfang

    2018-05-15

    Sensitivity amplification strategy by implementing click chemistry in the construction of biosensing interface can efficiently improve the performance of immunosensor. Herein, we developed a sandwich-type amperometric immunosensor for ultrasensitive detection of carbohydrate antigen 24-2 (CA 242) based on pH responsive label-assisted click chemistry triggered sensitivity amplification strategy. The sensitivity of amperometric immunosensor relies on the current response differences (ΔI) caused by per unit concentration target analyte. The pH responsive Cu 2+ -loaded polydopamine (CuPDA) particles conjugated with detection antibodies were employed as labels, which can release Cu(II) ions by regulating pH. In the presence of ascorbic acid (reductant), Cu(II) ions were reduced to Cu(I) ions. Azide-functionalized double-stranded DNA (dsDNA) as signal enhancer was immobilized on the substrate through Cu + -catalyzed azide/alkyne cycloaddition reaction. With the help of the click reaction, the ΔI caused by target was elevated prominently, resulting in sensitivity amplification of the immunosensor. Under optimal condition, the proposed immunosensor exhibited excellent performance with linear range from 0.0001 to 100 U mL -1 and ultralow detection limit of 20.74 μU mL -1 . This work successfully combines click chemistry with pH-responsive labels in sandwich-type amperometric immunosensor, providing a promising sensitivity amplification strategy to construct immunosensing platform for analysis of other tumor marker. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Basin-edge generated Rayleigh waves in the Almaty basin and corresponding consequences for ground motion amplification

    Science.gov (United States)

    Pilz, Marco; Parolai, Stefano; Petrovic, Bojana; Silacheva, Natalya; Abakanov, Tanatkan; Orunbaev, Sagynbek; Moldobekov, Bolot

    2018-04-01

    During the past two centuries, several large earthquakes have caused extensive damages in the city of Almaty in Kazakhstan. Increasing the preparedness for future events, the definition of the optimal engineering designs for civil structures and the corresponding mitigation of earthquake risks involves the accomplishment of site response studies. To this regard, a temporary seismological network of 15 stations was installed in the city aiming at the accurate identification of local variations of site response at different locations. As the city is settled on a deep sediment-filled plain with laterally strongly varying thicknesses, bound to the south by the Tien-Shan mountain range, the city might face important site effects: large amplification and significant increase of shaking duration. In addition, surface waves in the low-frequency range around and slightly higher than the fundamental resonance frequency, which could be generated at the boundaries of the basin, can carry a large amount of energy. In turn, this will influence both the spatial distribution of the level of amplification and the temporal lengthening of ground motion significantly. For quantifying these effects, we apply complex trace analysis, which uses the instantaneous polarization characteristics of the seismic signal for separating waves arriving at a single site from different directions. In this way, secondary surface waves originating at various sites along the edge of the Almaty basin can be identified as well as their generation regions. After having assessed 1-D amplification effects with well-established techniques like the standard spectral ratio and the horizontal-to-vertical spectral ratio techniques, the results further indicate that thick layers of soft clay deposits and the 3-D structure of the basin give rise to lengthening of ground motion and high amplification values at low frequencies around 0.2 Hz. The steep structure of the sediment-bedrock interface at the southern edge

  11. Digital Droplet Multiple Displacement Amplification (ddMDA for Whole Genome Sequencing of Limited DNA Samples.

    Directory of Open Access Journals (Sweden)

    Minsoung Rhee

    Full Text Available Multiple displacement amplification (MDA is a widely used technique for amplification of DNA from samples containing limited amounts of DNA (e.g., uncultivable microbes or clinical samples before whole genome sequencing. Despite its advantages of high yield and fidelity, it suffers from high amplification bias and non-specific amplification when amplifying sub-nanogram of template DNA. Here, we present a microfluidic digital droplet MDA (ddMDA technique where partitioning of the template DNA into thousands of sub-nanoliter droplets, each containing a small number of DNA fragments, greatly reduces the competition among DNA fragments for primers and polymerase thereby greatly reducing amplification bias. Consequently, the ddMDA approach enabled a more uniform coverage of amplification over the entire length of the genome, with significantly lower bias and non-specific amplification than conventional MDA. For a sample containing 0.1 pg/μL of E. coli DNA (equivalent of ~3/1000 of an E. coli genome per droplet, ddMDA achieves a 65-fold increase in coverage in de novo assembly, and more than 20-fold increase in specificity (percentage of reads mapping to E. coli compared to the conventional tube MDA. ddMDA offers a powerful method useful for many applications including medical diagnostics, forensics, and environmental microbiology.

  12. MYC and MYCN amplification can be reliably assessed by aCGH in medulloblastoma.

    Science.gov (United States)

    Bourdeaut, Franck; Grison, Camille; Maurage, Claude-Alain; Laquerriere, Annie; Vasiljevic, Alexandre; Delisle, Marie-Bernadette; Michalak, Sophie; Figarella-Branger, Dominique; Doz, François; Richer, Wilfrid; Pierron, Gaelle; Miquel, Catherine; Delattre, Olivier; Couturier, Jérôme

    2013-04-01

    As prognostic factors, MYC and MYCN amplifications are routinely assessed in medulloblastomas. Fluorescence in situ hybridization (FISH) is currently considered as the technique of reference. Recently, array comparative genomic hybridization (aCGH) has been developed as an alternative technique to evaluate genomic abnormalities in other tumor types; however, this technique has not been widely adopted as a replacement for FISH in medulloblastoma. In this study, 34 tumors were screened by both FISH and aCGH. In all cases showing amplification by FISH, aCGH also unambiguously revealed the abnormality. The aCGH technique was also performed on tumors showing no amplification by FISH, and the absence of amplification was confirmed in all cases. Interestingly, one tumor showed a subclonal MYC amplification by FISH. This subclonal amplification was observed in approximately 20% of tumor cells and was clearly evident on aCGH. In conclusion, our analysis confirms that aCGH is as safe as FISH for the detection of MYC/MYCN gene amplification. Given its cost efficiency in comparison to two FISH tests and the global genomic information additionally provided by an aCGH experiment, this reproducible technique can be safely retained as an alternative to FISH for routine investigation of medulloblastoma. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. N-myc oncogene amplification is correlated to trace metal concentrations in neuroblastoma cultured cells

    International Nuclear Information System (INIS)

    Gouget, B.; Sergeant, C.; Benard, J.; Llabador, Y.; Simonoff, M.

    2000-01-01

    N-myc oncogene amplification is a powerful predictor of aggressive behavior of neuroblastoma (NB), the most common solid tumor of the early childhood. Since N-myc overexpression - subsequent to amplification - determines a phenotype of invasiveness and metastatic spreading, it is assumed that N-myc amplified neuroblasts synthesize zinc metalloenzymes leading to tumor invasion and formation of metastases. In order to test a possible relation between N-myc oncogene amplification and trace metal contents in human NB cells, Fe, Cu and Zn concentrations have been measured by nuclear microprobe analysis in three human neuroblastoma cell lines with various degrees of N-myc amplification. Elemental determinations show uniform distribution of trace metals within the cells, but variations of intracellular trace metal concentrations with respect to the degree of N-myc amplification are highly dependent on the nature of the element. Zinc concentration is higher in both N-myc amplified cell lines (IMR-32 and IGR-N-91) than in the non-amplified cells (SK-N-SH). In contrast, intracellular iron content is particularly low in N-myc amplified cell lines. Moreover, copper concentrations showed an increase with the degree of N-myc amplification. These results indicate that a relationship exists between intracellular trace metals and N-myc oncogene amplification. They further suggest that trace metals very probably play a determinant role in mechanisms of the neuroblastoma invasiveness

  14. An evaluation of multiple annealing and looping based genome amplification using a synthetic bacterial community

    KAUST Repository

    Wang, Yong

    2016-02-23

    The low biomass in environmental samples is a major challenge for microbial metagenomic studies. The amplification of a genomic DNA was frequently applied to meeting the minimum requirement of the DNA for a high-throughput next-generation-sequencing technology. Using a synthetic bacterial community, the amplification efficiency of the Multiple Annealing and Looping Based Amplification Cycles (MALBAC) kit that is originally developed to amplify the single-cell genomic DNA of mammalian organisms is examined. The DNA template of 10 pg in each reaction of the MALBAC amplification may generate enough DNA for Illumina sequencing. Using 10 pg and 100 pg templates for each reaction set, the MALBAC kit shows a stable and homogeneous amplification as indicated by the highly consistent coverage of the reads from the two amplified samples on the contigs assembled by the original unamplified sample. Although GenomePlex whole genome amplification kit allows one to generate enough DNA using 100 pg of template in each reaction, the minority of the mixed bacterial species is not linearly amplified. For both of the kits, the GC-rich regions of the genomic DNA are not efficiently amplified as suggested by the low coverage of the contigs with the high GC content. The high efficiency of the MALBAC kit is supported for the amplification of environmental microbial DNA samples, and the concerns on its application are also raised to bacterial species with the high GC content.

  15. Basin amplification of seismic waves in the city of Pahrump, Nevada.

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, Robert E.

    2005-07-01

    Sedimentary basins can increase the magnitude and extend the duration of seismic shaking. This potential for seismic amplification is investigated for Pahrump Valley, Nevada-California. The Pahrump Valley is located approximately 50 km northwest of Las Vegas and 75 km south of the Nevada Test Site. Gravity data suggest that the city of Pahrump sits atop a narrow, approximately 5 km deep sub-basin within the valley. The seismic amplification, or ''site effect'', was investigated using a combination of in situ velocity modeling and comparison of the waveforms and spectra of weak ground motion recorded in the city of Pahrump, Nevada, and those recorded in the nearby mountains. Resulting spectral ratios indicate seismic amplification factors of 3-6 over the deepest portion of Pahrump Valley. This amplification predominantly occurs at 2-2.5 Hz. Amplification over the deep sub-basin is lower than amplification at the sub-basin edge, location of the John Blume and Associates PAHA seismic station, which recorded many underground nuclear tests at the Nevada Test Site. A comprehensive analysis of basin amplification for the city of Pahrump should include 3-D basin modeling, due to the extreme basement topography of the Pahrump Valley.

  16. Do Allergies Cause Asthma?

    Science.gov (United States)

    ... for Educators Search English Español Do Allergies Cause Asthma? KidsHealth / For Parents / Do Allergies Cause Asthma? Print ... son la causa del asma? Do Allergies Cause Asthma? Allergies don't cause asthma. But kids who ...

  17. Ligation-mediated PCR with a back-to-back adapter reduces amplification bias resulting from variations in GC content.

    Science.gov (United States)

    Ishihara, Satoru; Kotomura, Naoe; Yamamoto, Naoki; Ochiai, Hiroshi

    2017-08-15

    Ligation-mediated polymerase chain reaction (LM-PCR) is a common technique for amplification of a pool of DNA fragments. Here, a double-stranded oligonucleotide consisting of two primer sequences in back-to-back orientation was designed as an adapter for LM-PCR. When DNA fragments were ligated with this adapter, the fragments were sandwiched between two adapters in random orientations. In the ensuing PCR, ligation products linked at each end to an opposite side of the adapter, i.e. to a distinct primer sequence, were preferentially amplified compared with products linked at each end to an identical primer sequence. The use of this adapter in LM-PCR reduced the impairment of PCR by substrate DNA with a high GC content, compared with the use of traditional LM-PCR adapters. This result suggested that our method has the potential to contribute to reduction of the amplification bias that is caused by an intrinsic property of the sequence context in substrate DNA. A DNA preparation obtained from a chromatin immunoprecipitation assay using pulldown of a specific form of histone H3 was successfully amplified using the modified LM-PCR, and the amplified products could be used as probes in a fluorescence in situ hybridization analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. THE USE OF MULTIPLE DISPLACEMENT AMPLIFICATION TO INCREASE THE DETECTION AND GENOTYPING OF TRYPANOSOMA SPECIES SAMPLES IMMOBILISED ON FTA FILTERS

    Science.gov (United States)

    MORRISON, LIAM J.; McCORMACK, GILLIAN; SWEENEY, LINDSAY; LIKEUFACK, ANNE C. L.; TRUC, PHILIPPE; TURNER, C. MICHAEL; TAIT, ANDY; MacLEOD, ANNETTE

    2007-01-01

    Whole genome amplification methods are a recently developed tool for amplifying DNA from limited template. We report its application in trypanosome infections, characterised by low parasitaemias. Multiple Displacement Amplification (MDA) amplifies DNA with a simple in vitro step, and was evaluated on mouse blood samples on FTA filter cards with known numbers of Trypanosoma brucei parasites. The data showed a twenty-fold increase in the number of PCRs possible per sample, using primers diagnostic for the multi-copy ribosomal ITS region or 177 bp repeats, and a twenty-fold increase in sensitivity over nested PCR against a single copy microsatellite. Using MDA for microsatellite genotyping caused allele dropout at low DNA concentrations, which was overcome by pooling multiple MDA reactions. The validity of using MDA was established with samples from Human African Trypanosomiasis patients. The use of MDA allows maximal use of finite DNA samples and may prove a valuable tool in studies where multiple reactions are necessary, such as population genetic analyses. PMID:17556624

  19. Development and evaluation of a novel and rapid detection assay for Botrytis cinerea based on loop-mediated isothermal amplification.

    Directory of Open Access Journals (Sweden)

    Ya-Bing Duan

    Full Text Available Botrytis cinerea is a devastating plant pathogen that causes grey mould disease. In this study, we developed a visual detection method of B. cinerea based on the Bcos5 sequence using loop-mediated isothermal amplification (LAMP with hydroxynaphthol blue dye (HNB. The LAMP reaction was optimal at 63 °C for 45 min. When HNB was added prior to amplification, samples with B. cinerea DNA developed a characteristic sky blue color after the reaction but those without DNA or with DNA of other plant pathogenic fungi did not. Results of HNB staining method were reconfirmed when LAMP products were subjected to gel electrophoresis. The detection limit of this LAMP assay for B. cinerea was 10(-3 ng µL(-1 of genomic DNA per reaction, which was 10-fold more sensitive than conventional PCR (10(-2 ng µL(-1. Detection of the LAMP assay for inoculum of B. cinerea was possible in the inoculated tomato and strawberry petals. In the 191 diseased samples, 180 (94.2% were confirmed as positive by LAMP, 172 (90.1% positive by the tissue separation, while 147 (77.0% positive by PCR. Because the LAMP assay performed well in aspects of sensitivity, specificity, repeatability, reliability, and visibility, it is suitable for rapid detection of B. cinerea in infected plant materials prior to storage and during transportation, such as cut flowers, fruits and vegetables.

  20. Optimization of loop-mediated isothermal amplification (LAMP) assays for the detection of Leishmania DNA in human blood samples.

    Science.gov (United States)

    Abbasi, Ibrahim; Kirstein, Oscar D; Hailu, Asrat; Warburg, Alon

    2016-10-01

    Visceral leishmaniasis (VL), one of the most important neglected tropical diseases, is caused by Leishmania donovani eukaryotic protozoan parasite of the genus Leishmania, the disease is prevalent mainly in the Indian sub-continent, East Africa and Brazil. VL can be diagnosed by PCR amplifying ITS1 and/or kDNA genes. The current study involved the optimization of Loop-mediated isothermal amplification (LAMP) for the detection of Leishmania DNA in human blood or tissue samples. Three LAMP systems were developed; in two of those the primers were designed based on shared regions of the ITS1 gene among different Leishmania species, while the primers for the third LAMP system were derived from a newly identified repeated region in the Leishmania genome. The LAMP tests were shown to be sufficiently sensitive to detect 0.1pg of DNA from most Leishmania species. The green nucleic acid stain SYTO16, was used here for the first time to allow real-time monitoring of LAMP amplification. The advantage of real time-LAMP using SYTO 16 over end-point LAMP product detection is discussed. The efficacy of the real time-LAMP tests for detecting Leishmania DNA in dried blood samples from volunteers living in endemic areas, was compared with that of qRT-kDNA PCR. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Evaluation of colorimetric loop-mediated isothermal amplification assay for visual detection of Streptococcus agalactiae and Streptococcus iniae in tilapia.

    Science.gov (United States)

    Suebsing, R; Kampeera, J; Tookdee, B; Withyachumnarnkul, B; Turner, W; Kiatpathomchai, W

    2013-10-01

    Streptococcus agalactiae and Strep. iniae are bacterial pathogens that cause streptococcosis in many fish species. An accelerated colorimetric loop-mediated isothermal amplification (LAMP) assay with pre-addition of calcein was established, and the transmission and detection of Strep. agalactiae and Strep. iniae in tilapia under natural aquatic environment were investigated. A positive reaction was observed by a colour change from orange to green through the naked eyes after completion at 63°C for 30 min with 10 times higher sensitivity than that of nested PCR assays and without cross-amplification with other fish bacterial pathogens. All sample types of Nile and red tilapia (broodstock, fertilized egg, fry) were Strep. agalactiae- and Strep. iniae positive by this new method, implying that they could be vertically transmitted. With its application for screening broodstock and fry before stocking and for monitoring fish health in grow-out ponds, the method would become very useful in fish farming industry. The application of colorimetric LAMP with pre-addition of calcein offers simple, rapid and sensitive technique with applicability for small field laboratories. This technique explored the possible vertical transmission mode of Strep. agalactiae and Strep. iniae under natural aquatic environment. It could be such preliminary data provided for the screening broodstock before breeding and/or the specific-pathogen-free production. © 2013 The Society for Applied Microbiology.

  2. Real-time correction of tsunami site effect by frequency-dependent tsunami-amplification factor

    Science.gov (United States)

    Tsushima, H.

    2017-12-01

    For tsunami early warning, I developed frequency-dependent tsunami-amplification factor and used it to design a recursive digital filter that can be applicable for real-time correction of tsunami site response. In this study, I assumed that a tsunami waveform at an observing point could be modeled by convolution of source, path and site effects in time domain. Under this assumption, spectral ratio between offshore and the nearby coast can be regarded as site response (i.e. frequency-dependent amplification factor). If the amplification factor can be prepared before tsunamigenic earthquakes, its temporal convolution to offshore tsunami waveform provides tsunami prediction at coast in real time. In this study, tsunami waveforms calculated by tsunami numerical simulations were used to develop frequency-dependent tsunami-amplification factor. Firstly, I performed numerical tsunami simulations based on nonlinear shallow-water theory from many tsuanmigenic earthquake scenarios by varying the seismic magnitudes and locations. The resultant tsunami waveforms at offshore and the nearby coastal observing points were then used in spectral-ratio analysis. An average of the resulted spectral ratios from the tsunamigenic-earthquake scenarios is regarded as frequency-dependent amplification factor. Finally, the estimated amplification factor is used in design of a recursive digital filter that can be applicable in time domain. The above procedure is applied to Miyako bay at the Pacific coast of northeastern Japan. The averaged tsunami-height spectral ratio (i.e. amplification factor) between the location at the center of the bay and the outside show a peak at wave-period of 20 min. A recursive digital filter based on the estimated amplification factor shows good performance in real-time correction of tsunami-height amplification due to the site effect. This study is supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant 15K16309.

  3. MDM2 and CDK4 amplifications are rare events in salivary duct carcinomas.

    Science.gov (United States)

    Grünewald, Inga; Trautmann, Marcel; Busch, Alina; Bauer, Larissa; Huss, Sebastian; Schweinshaupt, Petra; Vollbrecht, Claudia; Odenthal, Margarete; Quaas, Alexander; Büttner, Reinhard; Meyer, Moritz F; Beutner, Dirk; Hüttenbrink, Karl-Bernd; Wardelmann, Eva; Stenner, Markus; Hartmann, Wolfgang

    2016-11-15

    Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands associated with poor clinical outcome. SDCs are known to carry TP53 mutations in about 50%, however, only little is known about alternative pathogenic mechanisms within the p53 regulatory network. Particularly, data on alterations of the oncogenes MDM2 and CDK4 located in the chromosomal region 12q13-15 are limited in SDC, while genomic rearrangements of the adjacent HMGA2 gene locus are well documented in subsets of SDCs. We here analyzed the mutational status of the TP53 gene, genomic amplification of MDM2, CDK4 and HMGA2 rearrangement/amplification as well as protein expression of TP53 (p53), MDM2 and CDK4 in 51 de novo and ex pleomorphic adenoma SDCs.25 of 51 cases were found to carry TP53 mutations, associated with extreme positive immunohistochemical p53 staining levels in 13 cases. Three out of 51 tumors had an MDM2 amplification, one of them coinciding with a CDK4 amplification and two with a HMGA2 rearrangement/amplification. Two of the MDM2 amplifications occurred in the setting of a TP53 mutation. Two out of 51 cases showed a CDK4 amplification, one synchronously being MDM2 amplified and the other one displaying concurrent low copy number increases of both, MDM2 and HMGA2.In summary, we here show that subgroups of SDCs display genomic amplifications of MDM2 and/or CDK4, partly in association with TP53 mutations and rearrangement/amplification of HMGA2. Further research is necessary to clarify the role of chromosomal region 12q13-15 alterations in SDC tumorigenesis and their potential prognostic and therapeutic relevance.

  4. Anisotropic amplification of proton transport in proton exchange membrane fuel cells

    Science.gov (United States)

    Thimmappa, Ravikumar; Fawaz, Mohammed; Devendrachari, Mruthyunjayachari Chattanahalli; Gautam, Manu; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Thotiyl, Musthafa Ottakam

    2017-07-01

    Though graphene oxide (GO) membrane shuttles protons under humid conditions, it suffer severe disintegration and anhydrous conditions lead to abysmal ionic conductivity. The trade-off between mechanical integrity and ionic conductivity challenge the amplification of GO's ionic transport under anhydrous conditions. We show anisotropic amplification of GO's ionic transport with a selective amplification of in plane contribution under anhydrous conditions by doping it with a plant extract, phytic acid (PA). The hygroscopic nature of PA stabilized interlayer water molecules and peculiar geometry of sbnd OH functionalities around saturated hydrocarbon ring anisotropically enhanced ionic transport amplifying the fuel cell performance metrics.

  5. Dynamic Characteristics of a Hydraulic Amplification Mechanism for Large Displacement Actuators Systems

    Directory of Open Access Journals (Sweden)

    Xavier Arouette

    2010-03-01

    Full Text Available We have developed a hydraulic displacement amplification mechanism (HDAM and studied its dynamic response when combined with a piezoelectric actuator. The HDAM consists of an incompressible fluid sealed in a microcavity by two largely deformable polydimethylsiloxane (PDMS membranes. The geometry with input and output surfaces having different cross-sectional areas creates amplification. By combining the HDAM with micro-actuators, we can amplify the input displacement generated by the actuators, which is useful for applications requiring large deformation, such as tactile displays. We achieved a mechanism offering up to 18-fold displacement amplification for static actuation and 12-fold for 55 Hz dynamic actuation.

  6. Amplification of electromagnetic radiation in the exciton region of the spectrum of a semiconductor

    International Nuclear Information System (INIS)

    Nerkararyan, Kh.V.

    1989-01-01

    The problem of amplification of electromagnetic radiation in the exciton region of the spectrum of a semiconductor was first discussed by Haken. The possibility of amplification of an electromagnetic wave under conditions of Bose condensation of biexcitons was considered in Ref. 2. However, the difficulties encountered in the creation of a Bose condensed state of biexcitons complicate greatly the performance of an experiment of this kind. The authors shall show that amplification is possible also in a gaseous mixture of excitons and biexcitons which is in thermal equilibrium and can be described by the Maxwellian distribution function of the velocities

  7. Realization of quantum state privacy amplification in a nuclear magnetic resonance quantum system

    International Nuclear Information System (INIS)

    Hao, Liang; Wang, Chuan; Long, Gui Lu

    2010-01-01

    Quantum state privacy amplification (QSPA) is the quantum analogue of classical privacy amplification. If the state information of a series of single-particle states has some leakage, QSPA reduces this leakage by condensing the state information of two particles into the state of one particle. Recursive applications of the operations will eliminate the quantum state information leakage to a required minimum level. In this paper, we report the experimental implementation of a quantum state privacy amplification protocol in a nuclear magnetic resonance system. The density matrices of the states are constructed in the experiment, and the experimental results agree well with theory.

  8. A rapid Salmonella detection method involving thermophilic helicase-dependent amplification and a lateral flow assay.

    Science.gov (United States)

    Du, Xin-Jun; Zhou, Tian-Jiao; Li, Ping; Wang, Shuo

    2017-08-01

    Salmonella is a major foodborne pathogen that is widespread in the environment and can cause serious human and animal disease. Since conventional culture methods to detect Salmonella are time-consuming and laborious, rapid and accurate techniques to detect this pathogen are critically important for food safety and diagnosing foodborne illness. In this study, we developed a rapid, simple and portable Salmonella detection strategy that combines thermophilic helicase-dependent amplification (tHDA) with a lateral flow assay to provide a detection result based on visual signals within 90 min. Performance analyses indicated that the method had detection limits for DNA and pure cultured bacteria of 73.4-80.7 fg and 35-40 CFU, respectively. Specificity analyses showed no cross reactions with Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Enterobacter aerogenes, Shigella and Campylobacter jejuni. The results for detection in real food samples showed that 1.3-1.9 CFU/g or 1.3-1.9 CFU/mL of Salmonella in contaminated chicken products and infant nutritional cereal could be detected after 2 h of enrichment. The same amount of Salmonella in contaminated milk could be detected after 4 h of enrichment. This tHDA-strip can be used for the rapid detection of Salmonella in food samples and is particularly suitable for use in areas with limited equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Stochastic amplification and signaling in enzymatic futile cycles through noise-induced bistability with oscillations

    Science.gov (United States)

    Samoilov, Michael; Plyasunov, Sergey; Arkin, Adam P.

    2005-02-01

    Stochastic effects in biomolecular systems have now been recognized as a major physiologically and evolutionarily important factor in the development and function of many living organisms. Nevertheless, they are often thought of as providing only moderate refinements to the behaviors otherwise predicted by the classical deterministic system description. In this work we show by using both analytical and numerical investigation that at least in one ubiquitous class of (bio)chemical-reaction mechanisms, enzymatic futile cycles, the external noise may induce a bistable oscillatory (dynamic switching) behavior that is both quantitatively and qualitatively different from what is predicted or possible deterministically. We further demonstrate that the noise required to produce these distinct properties can itself be caused by a set of auxiliary chemical reactions, making it feasible for biological systems of sufficient complexity to generate such behavior internally. This new stochastic dynamics then serves to confer additional functional modalities on the enzymatic futile cycle mechanism that include stochastic amplification and signaling, the characteristics of which could be controlled by both the type and parameters of the driving noise. Hence, such noise-induced phenomena may, among other roles, potentially offer a novel type of control mechanism in pathways that contain these cycles and the like units. In particular, observations of endogenous or externally driven noise-induced dynamics in regulatory networks may thus provide additional insight into their topology, structure, and kinetics. network motif | signal transduction | chemical reaction | synthetic biology | systems biology

  10. A sensitive detection assay based on signal amplification technology for Alzheimer's disease's early biomarker in exosome.

    Science.gov (United States)

    Zhou, Jie; Meng, Lingchang; Ye, Weiran; Wang, Qiaolei; Geng, Shizhen; Sun, Chong

    2018-08-31

    Alzheimer's disease (AD) considered as the third health "killer" has seriously threatened the health of the elderly. However, the modern diagnostic strategies of AD present several disadvantages: the low accuracy and specificity resulting in some false-negative diagnoses, and the poor sensitivity leading to a delayed treatment. In view of this situation, a enzyme-free and target-triggered signal amplification strategy, based on graphene oxide (GO) and entropy-driven strand displacement reaction (ESDR) principle, was proposed. In this strategy, when the hairpin structure probes (H)specially binds with beta-amyloid-(1-42) oligomers (Aβ42 oligomers), it's structure will be opened, causing the bases complementary to FAM-labeled replacement probes R (R1 and R2) exposed. At this time, R1 and R2 will hybridize with H, resulting in the bound Aβ42 oligomers released. The released Aβ42 oligomers would participate in the next cycle reaction, making the signal amplified. As a quencher, GO could absorb the free single-stranded DNA R1 and R2 and quench their fluorescence; however, the DNA duplex still exists free and keeps its signal-on. Through the detection of Aβ42 oligomers in exosomes, this ultrasensitive detection method with the advantages of low limit of detection (LOD, 20 pM), great accuracy, excellent precision and convenience provides an excellent prospect for AD's early diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Prion Amplification and Hierarchical Bayesian Modeling Refine Detection of Prion Infection

    Science.gov (United States)

    Wyckoff, A. Christy; Galloway, Nathan; Meyerett-Reid, Crystal; Powers, Jenny; Spraker, Terry; Monello, Ryan J.; Pulford, Bruce; Wild, Margaret; Antolin, Michael; Vercauteren, Kurt; Zabel, Mark

    2015-02-01

    Prions are unique infectious agents that replicate without a genome and cause neurodegenerative diseases that include chronic wasting disease (CWD) of cervids. Immunohistochemistry (IHC) is currently considered the gold standard for diagnosis of a prion infection but may be insensitive to early or sub-clinical CWD that are important to understanding CWD transmission and ecology. We assessed the potential of serial protein misfolding cyclic amplification (sPMCA) to improve detection of CWD prior to the onset of clinical signs. We analyzed tissue samples from free-ranging Rocky Mountain elk (Cervus elaphus nelsoni) and used hierarchical Bayesian analysis to estimate the specificity and sensitivity of IHC and sPMCA conditional on simultaneously estimated disease states. Sensitivity estimates were higher for sPMCA (99.51%, credible interval (CI) 97.15-100%) than IHC of obex (brain stem, 76.56%, CI 57.00-91.46%) or retropharyngeal lymph node (90.06%, CI 74.13-98.70%) tissues, or both (98.99%, CI 90.01-100%). Our hierarchical Bayesian model predicts the prevalence of prion infection in this elk population to be 18.90% (CI 15.50-32.72%), compared to previous estimates of 12.90%. Our data reveal a previously unidentified sub-clinical prion-positive portion of the elk population that could represent silent carriers capable of significantly impacting CWD ecology.

  12. A recombinase polymerase amplification assay for rapid detection of Crimean-Congo Haemorrhagic fever Virus infection.

    Directory of Open Access Journals (Sweden)

    Laura C Bonney

    2017-10-01

    Full Text Available Crimean-Congo Haemorrhagic fever Virus (CCHFV is a rapidly emerging vector-borne pathogen and the cause of a virulent haemorrhagic fever affecting large parts of Europe, Africa, the Middle East and Asia.An isothermal recombinase polymerase amplification (RPA assay was successfully developed for molecular detection of CCHFV. The assay showed rapid (under 10 minutes detection of viral extracts/synthetic virus RNA of all 7 S-segment clades of CCHFV, with high target specificity. The assay was shown to tolerate the presence of inhibitors in crude preparations of mock field samples, indicating that this assay may be suitable for use in the field with minimal sample preparation. The CCHFV RPA was successfully used to screen and detect CCHFV positives from a panel of clinical samples from Tajikistan.The assay is a rapid, isothermal, simple-to-perform molecular diagnostic, which can be performed on a light, portable real-time detection device. It is ideally placed therefore for use as a field-diagnostic or in-low resource laboratories, for monitoring of CCHF outbreaks at the point-of-need, such as in remote rural regions in affected countries.

  13. Prion amplification and hierarchical Bayesian modeling refine detection of prion infection.

    Science.gov (United States)

    Wyckoff, A Christy; Galloway, Nathan; Meyerett-Reid, Crystal; Powers, Jenny; Spraker, Terry; Monello, Ryan J; Pulford, Bruce; Wild, Margaret; Antolin, Michael; VerCauteren, Kurt; Zabel, Mark

    2015-02-10

    Prions are unique infectious agents that replicate without a genome and cause neurodegenerative diseases that include chronic wasting disease (CWD) of cervids. Immunohistochemistry (IHC) is currently considered the gold standard for diagnosis of a prion infection but may be insensitive to early or sub-clinical CWD that are important to understanding CWD transmission and ecology. We assessed the potential of serial protein misfolding cyclic amplification (sPMCA) to improve detection of CWD prior to the onset of clinical signs. We analyzed tissue samples from free-ranging Rocky Mountain elk (Cervus elaphus nelsoni) and used hierarchical Bayesian analysis to estimate the specificity and sensitivity of IHC and sPMCA conditional on simultaneously estimated disease states. Sensitivity estimates were higher for sPMCA (99.51%, credible interval (CI) 97.15-100%) than IHC of obex (brain stem, 76.56%, CI 57.00-91.46%) or retropharyngeal lymph node (90.06%, CI 74.13-98.70%) tissues, or both (98.99%, CI 90.01-100%). Our hierarchical Bayesian model predicts the prevalence of prion infection in this elk population to be 18.90% (CI 15.50-32.72%), compared to previous estimates of 12.90%. Our data reveal a previously unidentified sub-clinical prion-positive portion of the elk population that could represent silent carriers capable of significantly impacting CWD ecology.

  14. Loop-mediated isothermal amplification: rapid detection of Angiostrongylus cantonensis infection in Pomacea canaliculata

    Directory of Open Access Journals (Sweden)

    Zhuo MingMing

    2011-10-01

    Full Text Available Abstract Background Angiostrongylus cantonensis is a zoonotic parasite that causes eosinophilic meningitis in humans. The most common source of infection with A. cantonensis is the consumption of raw or undercooked mollusks (e.g., snails and slugs harbouring infectious third-stage larvae (L3. However, the parasite is difficult to identify in snails. The purpose of this study was to develop a quick, simple molecular method to survey for A. cantonensis in intermediate host snails. Findings We used a loop-mediated isothermal amplification (LAMP assay, which was performed using Bst DNA polymerase. Reactions amplified the A. cantonensis 18S rRNA gene and demonstrated high sensitivity; as little as 1 fg of DNA was detected in the samples. Furthermore, no cross-reactivity was found with other parasites such as Toxoplasma gondii, Plasmodium falciparum, Schistosoma japonicum, Clonorchis sinensis, Paragonimus westermani and Anisakis. Pomacea canaliculata snails were exposed to A. cantonensis first-stage larvae (L1 in the laboratory, and L3 were observed in the snails thirty-five days after infection. All nine samples were positive as determined by the LAMP assay for A. cantonensis, which was identified as positive by using PCR and microscopy, this demonstrates that LAMP is sensitive and effective for diagnosis. Conclusions LAMP is an appropriate diagnostic method for the routine identification of A. cantonensis within its intermediate host snail P. canaliculata because of its simplicity, sensitivity, and specificity. It holds great promise as a useful monitoring tool for A. cantonensis in endemic regions.

  15. Detection of bovine mastitis pathogens by loop-mediated isothermal amplification and an electrochemical DNA chip.

    Science.gov (United States)

    Kawai, Kazuhiro; Inada, Mika; Ito, Keiko; Hashimoto, Koji; Nikaido, Masaru; Hata, Eiji; Katsuda, Ken; Kiku, Yoshio; Tagawa, Yuichi; Hayashi, Tomohito

    2017-12-22

    Bovine mastitis causes significant economic losses in the dairy industry. Effective prevention of bovine mastitis requires an understanding of the infection status of a pathogenic microorganism in a herd that has not yet shown clinical signs of mastitis and appropriate treatment specific for the pathogenic microorganism. However, bacterial identification by culture has drawbacks in that the sensitivity may be low and the procedure can be complex. In this study, we developed a genetic detection method to identify mastitis pathogens using a simple and highly sensitive electrochemical DNA chip which can specifically detect bacterial DNA in milk specimens. First, we selected microorganisms belonging to 12 families and/or genera associated with mastitis for which testing should be performed. Next, we optimized the conditions for amplifying microorganism DNA by loop-mediated isothermal amplification (LAMP) using 32 primers and the use of a DNA chip capable of measuring all pathogens simultaneously. Sample detection could be completed in just a few hours using this method. Comparison of the results obtained with our DNA chip method and those obtained by bacterial culture verified that when the culture method was set to 100%, the total positive concordance rate of the DNA chip was 85.0% and the total negative concordance rate was 86.9%. Furthermore, the proposed method allows both rapid and highly sensitive detection of mastitis pathogens. We believe that this method will contribute to the development of an effective mastitis control program.

  16. Self-organized critical noise amplification in human closed loop control

    Directory of Open Access Journals (Sweden)

    Felix Patzelt

    2007-11-01

    Full Text Available When humans perform closed loop control tasks like in upright standing or while balancing a stick, their behavior exhibits non-Gaussian fluctuations with long-tailed distributions. The origin of these fluctuations is not known. Here, we investigate if they are caused by selforganized critical noise amplification which emerges in control systems when an unstable dynamics becomes stabilized by an adaptive controller that has finite memory. Starting from this theory, we formulate a realistic model of adaptive closed loop control by including constraints on memory and delays. To test this model, we performed psychophysical experiments where humans balanced an unstable target on a screen. It turned out that the model reproduces the long tails of the distributions together with other characteristic features of the human control dynamics. Fine-tuning the model to match the experimental dynamics identifies parameters characterizing a subject’s control system which can be independently tested. Our results suggest that the nervous system involved in closed loop motor control nearly optimally estimates system parameters on-line from very short epochs of past observations.

  17. Amplification of acid formation from diphenyliodonium salt in γ-irradiated polymers

    International Nuclear Information System (INIS)

    Yamazaki, K.; Iino, K.; Koizumi, H.; Ichikawa, T.

    2006-01-01

    The G values of acid formation from diphenyliodonium salt in γ-irradiated polymers have been measured for developing chemically amplified radiation resists that have abilities of not only amplifying chemical reactions of polymers by the acid as a catalyst but also amplifying the formation of acid itself by a radiation-induced radical chain reaction. Addition of secondary alcohols as amplifiers for acid formation, to poly(alkyl methacrylates) results in the increase of the G value, though the increase is not so significant as that expected from a liquid-phase amplification reaction. The diffusion of free radicals and added molecules is difficult in the polymers due to cage effects by polymer molecules, which causes increases of the radical combination reaction and therefore decrease of the turnover number of the chain reaction. The G values of acid formation for poly(vinyl acetals) are much higher than those for poly(alkyl methacrylates) even the amplifiers are not added in the former polymers. Poly(vinyl acetals) are synthesized by acetalyzation of poly(vinyl alcohol), a polymer composed of secondary alcohol monomer unit, so that the secondary alcohol remaining in the polymer skeleton acts as an efficient amplifier for acid formation. The secondary alcohol acts as stepping-stones for the diffusion of free radical, so that the free radical can encounter a new iodonium salt molecule to continue the radical chain reaction. (authors)

  18. Loop-Mediated Isothermal Amplification Targeting Actin DNA of Trichomonas vaginalis.

    Science.gov (United States)

    Goo, Youn-Kyoung; Shin, Won-Sik; Yang, Hye-Won; Joo, So-Young; Song, Su-Min; Ryu, Jae-Sook; Kong, Hyun-Hee; Lee, Won-Ki; Chung, Dong-Il; Hong, Yeonchul

    2016-06-01

    Trichomoniasis caused by Trichomonas vaginalis is a common sexually transmitted disease. Its association with several health problems, including preterm birth, pelvic inflammatory disease, cervical cancer, and transmission of human immunodeficiency virus, emphasizes the importance of improved access to early and accurate detection of T. vaginalis. In this study, a rapid and efficient loop-mediated isothermal amplification-based method for the detection of T. vaginalis was developed and validated, using vaginal swab specimens from subjects suspected to have trichomoniasis. The LAMP assay targeting the actin gene was highly sensitive with detection limits of 1 trichomonad and 1 pg of T. vaginalis DNA per reaction, and specifically amplified the target gene only from T. vaginalis. Validation of this assay showed that it had the highest sensitivity and better agreement with PCR (used as the gold standard) compared to microscopy and multiplex PCR. This study showed that the LAMP assay, targeting the actin gene, could be used to diagnose early infections of T. vaginalis. Thus, we have provided an alternative molecular diagnostic tool and a point-of-care test that may help to prevent trichomoniasis transmission and associated complications.

  19. Development of a Loop Mediated Isothermal Amplification for Diagnosis of Ascaris lumbricoides in Fecal Samples

    Directory of Open Access Journals (Sweden)

    Esther A. Shiraho

    2016-01-01

    Full Text Available Ascaris lumbricoides is a nematode parasite that causes the common tropical infection ascariasis in humans. It is also considered among the neglected tropical diseases. Diagnosis relies mainly on microscopy-based methods which are laborious, are limited by low sensitivity, and require high expertise. We have developed a loop mediated isothermal amplification (LAMP for diagnosis of ascariasis in fecal samples, based on the first internal transcribed (ITS-1 spacer region of the ribosomal DNA. We used Primer Explorer V4 software to design primers. Ascaris adult and ova were obtained from naturally infected school children, whose parents/guardians gave consent for their participation in the study. Genomic DNA was extracted using alkaline lysis method and amplified by LAMP at 63°C for 45 minutes. LAMP products were visualized by naked eyes after adding SYBR Green dye and also on agarose gel. LAMP successfully and reliably detected Ascaris DNA from a single egg and in fecal samples. The assay specifically detected Ascaris DNA without amplifying DNA from ova of other parasites which commonly coexist with A. lumbricoides in feces. The developed LAMP assay has great potential for use in ascariasis diagnosis at the point of care and in low infection intensity situation that characterize control and elimination campaigns.

  20. A real-time loop-mediated isothermal amplification assay for rapid detection of Shigella species.

    Science.gov (United States)

    Liew, P S; Teh, C S J; Lau, Y L; Thong, K L

    2014-12-01

    Shigellosis is a foodborne illness caused by the genus Shigella and is an important global health issue. The development of effective techniques for rapid detection of this pathogen is essential for breaking the chain of transmission. Therefore, we have developed a novel loop-mediated isothermal amplification (LAMP) assay targeting the invasion plasmid antigen H (ipaH) gene to rapidly detect Shigella species. This assay could be performed in 90 min at an optimal temperature of 64ºC, with endpoint results visualized directly. Notably, the method was found to be more sensitive than conventional PCR. Indeed, the detection limit for the LAMP assay on pure bacterial cultures was 5.9 x 10(5) CFU/ml, while PCR displayed a limit of 5.9 x 10(7) CFU/ml. In spiked lettuce samples, the sensitivity of the LAMP assay was 3.6 x 10(4) CFU/g, whereas PCR was 3.6 x 10(5) CFU/g. Overall, the assay accurately identified 32 Shigella spp. with one enteroinvasive Escherichia coli displaying positive reaction while the remaining 32 non-Shigella strains tested were negative.

  1. Rapid and sensitive detection of Bordetella bronchiseptica by loop-mediated isothermal amplification (LAMP

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2013-10-01

    Full Text Available Bordetella bronchiseptica causes acute and chronic respiratory infections in diverse animal species and occasionally in humans. In this study, we described the establishment of a simple, sensitive and cost-efficient loop-mediated isothermal amplification (LAMP assay for the detection of B. bronchiseptica. A set of primers towards a 235 bp region within the flagellum gene of B. bronchiseptica was designed with online software.. The specificity of the LAMP assay was examined by using 6 porcine pathogens and 100 nasal swabs collected from healthy pigs and suspect infected pigs. The results indicated that positive reactions were confirmed for all B. bronchiseptica and no cross-reactivity was observed from other non-B. bronchiseptica. In sensitivity evaluations, the technique successfully detected a serial dilutions of extracted B. bronchiseptica DNA with a detection limit of 9 copies, which was 10 times more sensitive than that of PCR. Compared with conventional PCR, the higher sensitivity of LAMP method and no need for the complex instrumentation make this LAMP assay a promising alternative for the diagnosis of B. bronchiseptica in rural areas and developing countries where there lacks of complex laboratory services.

  2. Elevated OPN, IP-10, and Neutrophilia in Loop-Mediated Isothermal Amplification Confirmed Tuberculosis Patients

    Directory of Open Access Journals (Sweden)

    Beata Shiratori

    2014-01-01

    Full Text Available Tuberculosis (TB is the second most common cause of death from infectious diseases and results in high socioeconomic losses to many countries. Proper diagnosis is the first step in TB eradication. To develop a rapid, simple, and accurate diagnostic TB test and to characterize the prevalence of Mycobacterium tuberculosis (MTB genotypes and immune profiles of TB patients, a total of 37 TB patients and 30 healthy control (HC from Metro Manila were enrolled. Loop-mediated isothermal amplification (LAMP reliably detected MTB infection. Manila genotype was identified by spoligotyping method in all TB patients. Osteopontin (OPN, interferon-γ-induced protein 10 kDa (IP-10, and neutrophil counts were found to reflect the acute stage of MTB infection. The sensitivity and specificity were 94.6% and 93.3%, respectively, for both OPN and IP-10, and they were 83.8% and 78.6%, respectively, for neutrophils. The combination of OPN, IP-10, neutrophil count, IL-6, IL-8, TNF-α, MCP-1, platelets, galectin-9, and leukocyte count correctly identifies all the HC and 96.3% of TB patients. LAMP method may serve as a rapid, supportive method in addition to time-consuming culture methods. OPN, IP-10, and neutrophil counts are useful in detecting MTB infection and may have utility in monitoring the course of the disease.

  3. Detection of Brucellosis in Sika Deer ( Cervus nippon ) through Loop-mediated Isothermal Amplification (LAMP).

    Science.gov (United States)

    Liu, Qianhong; Wei, Jie; Sun, Qingsong; Wang, Ben; Wang, Yuting; Hu, Ying; Wu, Wenrong

    2017-07-01

    Brucellosis (Brucella bovis) in sika deer ( Cervus nippon ) can cause enormous losses to stag breeding, especially in areas in which stag breeding has become an important industry. It also poses a threat to humans because it is a zoonotic disease. Use of the loop-mediated isothermal amplification (LAMP) assay has been poorly described in the diagnosis of brucellosis in deer. We developed a LAMP assay targeting the omp25 gene sequence to detect brucellosis in sika deer. The reaction can be completed in 60 min at 63 C and, with a detection limit of 17 pg, it was more sensitive than conventional PCR, with its detection limit of 1.7 ng. No cross-reactivity was observed with four bacteria: Escherichia coli , Salmonella enterica subsp. enterica, Clostridium pasteurianum , and Pseudomonas aeruginosa . We used 263 samples of blood to evaluate the reaction. The percentage of agreement between LAMP and PCR reached 91%; relative specificity reached 87%, and relative sensitivity reached 100%. The results indicate LAMP can be a simple and rapid diagnostic tool for detecting brucellosis in sika deer, particularly in the field, where it is essential to control brucellosis in deer with a rapid and accurate diagnosis for removal of positive animals.

  4. Search for methylation-sensitive amplification polymorphisms in mutant figs.

    Science.gov (United States)

    Rodrigues, M G F; Martins, A B G; Bertoni, B W; Figueira, A; Giuliatti, S

    2013-07-08

    Fig (Ficus carica) breeding programs that use conventional approaches to develop new cultivars are rare, owing to limited genetic variability and the difficulty in obtaining plants via gamete fusion. Cytosine methylation in plants leads to gene repression, thereby affecting transcription without changing the DNA sequence. Previous studies using random amplification of polymorphic DNA and amplified fragment length polymorphism markers revealed no polymorphisms among select fig mutants that originated from gamma-irradiated buds. Therefore, we conducted methylation-sensitive amplified polymorphism analysis to verify the existence of variability due to epigenetic DNA methylation among these mutant selections compared to the main cultivar 'Roxo-de-Valinhos'. Samples of genomic DNA were double-digested with either HpaII (methylation sensitive) or MspI (methylation insensitive) and with EcoRI. Fourteen primer combinations were tested, and on an average, non-methylated CCGG, symmetrically methylated CmCGG, and hemimethylated hmCCGG sites accounted for 87.9, 10.1, and 2.0%, respectively. MSAP analysis was effective in detecting differentially methylated sites in the genomic DNA of fig mutants, and methylation may be responsible for the phenotypic variation between treatments. Further analyses such as polymorphic DNA sequencing are necessary to validate these differences, standardize the regions of methylation, and analyze reads using bioinformatic tools.

  5. Using DNS amplification DDoS attack for hiding data

    Science.gov (United States)

    Mehić, M.; Voznak, M.; Safarik, J.; Partila, P.; Mikulec, M.

    2014-05-01

    This paper concerns available steganographic techniques that can be used for sending hidden data through public network. Typically, in steganographic communication it is advised to use popular/often used method for sending hidden data and amount of that data need to be high as much as possible. We confirmed this by choosing a Domain Name System (DNS) as a vital protocol of each network and choosing Distributed denial of service (DDoS) attacks that are most popular network attacks currently represented in the world. Apart from characterizing existing steganographic methods we provide new insights by presenting two new techniques. The first one is network steganography solution which exploits free/unused protocols fields and is known for IP, UDP or TCP protocols, but has never been applied to DNS (Domain Name Server) which are the fundamental part of network communications. The second explains the usage of DNS Amplification DDoS Attack to send seamlessly data through public network. The calculation that was performed to estimate the total amount of data that can be covertly transferred by using these technique, regardless of steganalysis, is included in this paper.

  6. Hypsometric Amplification of Greenland Ice Sheet Meltwater Release

    Science.gov (United States)

    van As, D.; Hasholt, B.; Mikkelsen, A. B.; Holtegaard Nielsen, M.; Box, J.; Claesson Liljedahl, L.; Lindback, K.; Pitcher, L. H.

    2017-12-01

    Proglacial discharge monitoring provides valuable insights in Greenland ice sheet meltwater release. We use a 2006-2016 discharge time series from the Watson River draining 12000 km2 of the ice sheet in southwest Greenland to investigate the large variability in catchment-total meltwater production. An observationally-constrained reconstruction of past discharge shows that meltwater release has on average increased by a factor of 1.5 since 2003 compared to the 1949-2002 period, and that interannual variability has disproportionally increased by a factor of 2.1, suggesting that melt amplifiers are at play. We derive a hypsometric amplification factor of 1.6, which is the result of the exponential melt area increase with rising temperature. Peak meltwater discharge events such as during the July 2012 flooding are due to this and other melt amplifiers, but also require intense melting over a period exceeding the multi-day transit time for high-elevation meltwater to pass through the glacial drainage system.

  7. The amplification of risk in experimental diffusion chains.

    Science.gov (United States)

    Moussaïd, Mehdi; Brighton, Henry; Gaissmaier, Wolfgang

    2015-05-05

    Understanding how people form and revise their perception of risk is central to designing efficient risk communication methods, eliciting risk awareness, and avoiding unnecessary anxiety among the public. However, public responses to hazardous events such as climate change, contagious outbreaks, and terrorist threats are complex and difficult-to-anticipate phenomena. Although many psychological factors influencing risk perception have been identified in the past, it remains unclear how perceptions of risk change when propagated from one person to another and what impact the repeated social transmission of perceived risk has at the population scale. Here, we study the social dynamics of risk perception by analyzing how messages detailing the benefits and harms of a controversial antibacterial agent undergo change when passed from one person to the next in 10-subject experimental diffusion chains. Our analyses show that when messages are propagated through the diffusion chains, they tend to become shorter, gradually inaccurate, and increasingly dissimilar between chains. In contrast, the perception of risk is propagated with higher fidelity due to participants manipulating messages to fit their preconceptions, thereby influencing the judgments of subsequent participants. Computer simulations implementing this simple influence mechanism show that small judgment biases tend to become more extreme, even when the injected message contradicts preconceived risk judgments. Our results provide quantitative insights into the social amplification of risk perception, and can help policy makers better anticipate and manage the public response to emerging threats.

  8. NEW ERBIUM DOPED ANTIMONY GLASSES FOR LASER AND GLASS AMPLIFICATION

    Directory of Open Access Journals (Sweden)

    B. Tioua

    2015-07-01

    Full Text Available Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses. In this poster will offer new doped erbium glasses synthesized in silicate crucibles were obtained in the combination Sb2O3-WO3-Na2O. Several properties are measured and correlated with glass compositions. The absorption spectral studies have been performed for erbium doped glasses. The intensities of various absorption bands of the doped glasses are measured and the Judd-Ofelt parameters have been computed. From the theory of Judd-Ofelt, various radiative properties, such as transition probability, branching ratio and radiative life time for various emission levels of these doped glasses have been determined and reported. These results confirm the ability of antimony glasses for glass amplification.

  9. Current Technologies of Electrochemical Immunosensors: Perspective on Signal Amplification

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    Il-Hoon Cho

    2018-01-01

    Full Text Available An electrochemical immunosensor employs antibodies as capture and detection means to produce electrical charges for the quantitative analysis of target molecules. This sensor type can be utilized as a miniaturized device for the detection of point-of-care testing (POCT. Achieving high-performance analysis regarding sensitivity has been one of the key issues with developing this type of biosensor system. Many modern nanotechnology efforts allowed for the development of innovative electrochemical biosensors with high sensitivity by employing various nanomaterials that facilitate the electron transfer and carrying capacity of signal tracers in combination with surface modification and bioconjugation techniques. In this review, we introduce novel nanomaterials (e.g., carbon nanotube, graphene, indium tin oxide, nanowire and metallic nanoparticles in order to construct a high-performance electrode. Also, we describe how to increase the number of signal tracers by employing nanomaterials as carriers and making the polymeric enzyme complex associated with redox cycling for signal amplification. The pros and cons of each method are considered throughout this review. We expect that these reviewed strategies for signal enhancement will be applied to the next versions of lateral-flow paper chromatography and microfluidic immunosensor, which are considered the most practical POCT biosensor platforms.

  10. Amplification of local changes along the timescale processing hierarchy.

    Science.gov (United States)

    Yeshurun, Yaara; Nguyen, Mai; Hasson, Uri

    2017-08-29

    Small changes in word choice can lead to dramatically different interpretations of narratives. How does the brain accumulate and integrate such local changes to construct unique neural representations for different stories? In this study, we created two distinct narratives by changing only a few words in each sentence (e.g., "he" to "she" or "sobbing" to "laughing") while preserving the grammatical structure across stories. We then measured changes in neural responses between the two stories. We found that differences in neural responses between the two stories gradually increased along the hierarchy of processing timescales. For areas with short integration windows, such as early auditory cortex, the differences in neural responses between the two stories were relatively small. In contrast, in areas with the longest integration windows at the top of the hierarchy, such as the precuneus, temporal parietal junction, and medial frontal cortices, there were large differences in neural responses between stories. Furthermore, this gradual increase in neural differences between the stories was highly correlated with an area's ability to integrate information over time. Amplification of neural differences did not occur when changes in words did not alter the interpretation of the story (e.g., sobbing to "crying"). Our results demonstrate how subtle differences in words are gradually accumulated and amplified along the cortical hierarchy as the brain constructs a narrative over time.

  11. Current Developments in Prokaryotic Single Cell Whole Genome Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Goudeau, Danielle; Nath, Nandita; Ciobanu, Doina; Cheng, Jan-Fang; Malmstrom, Rex

    2014-03-14

    Our approach to prokaryotic single-cell Whole Genome Amplification at the JGI continues to evolve. To increase both the quality and number of single-cell genomes produced, we explore all aspects of the process from cell sorting to sequencing. For example, we now utilize specialized reagents, acoustic liquid handling, and reduced reaction volumes eliminate non-target DNA contamination in WGA reactions. More specifically, we use a cleaner commercial WGA kit from Qiagen that employs a UV decontamination procedure initially developed at the JGI, and we use the Labcyte Echo for tip-less liquid transfer to set up 2uL reactions. Acoustic liquid handling also dramatically reduces reagent costs. In addition, we are exploring new cell lysis methods including treatment with Proteinase K, lysozyme, and other detergents, in order to complement standard alkaline lysis and allow for more efficient disruption of a wider range of cells. Incomplete lysis represents a major hurdle for WGA on some environmental samples, especially rhizosphere, peatland, and other soils. Finding effective lysis strategies that are also compatible with WGA is challenging, and we are currently assessing the impact of various strategies on genome recovery.

  12. PRC1 Prevents Replication Stress during Chondrogenic Transit Amplification

    Directory of Open Access Journals (Sweden)

    Frank Spaapen

    2017-12-01

    Full Text Available Transit amplification (TA, a state of combined, rapid proliferative expansion and differentiation of stem cell-descendants, remains poorly defined at the molecular level. The Polycomb Repressive Complex 1 (PRC1 protein BMI1 has been localized to TA compartments, yet its exact role in TA is unclear. PRC1 proteins control gene expression, cell proliferation and DNA-damage repair. Coordination of such DNA-templated activities during TA is predicted to be crucial to support DNA replication and differentiation-associated transcriptional programming. We here examined whether chondrogenesis provides a relevant biological context for synchronized coordination of these chromatin-based tasks by BMI1. Taking advantage of a prominently featuring TA-phase during chondrogenesis in vitro and in vivo, we here report that TA is completely dependent on intact PRC1 function. BMI1-depleted chondrogenic progenitors rapidly accumulate double strand DNA breaks during DNA replication, present massive non-H3K27me3-directed transcriptional deregulation and fail to undergo chondrogenic TA. Genome-wide accumulation of Topoisomerase 2α and Geminin suggests a model in which PRC1 synchronizes replication and transcription during rapid chondrogenic progenitor expansion. Our combined data reveals for the first time a vital cell-autonomous role for PRC1 during chondrogenesis. We provide evidence that chondrocyte hyper-replication and hypertrophy represent a unique example of programmed senescence in vivo. These findings provide new perspectives on PRC1 function in development and disease.

  13. Optimization and characterization of dual-chirped optical parametric amplification

    International Nuclear Information System (INIS)

    Fu, Yuxi; Takahashi, Eiji J; Midorikawa, Katsumi; Zhang, Qingbin; Lu, Peixiang

    2015-01-01

    We report optimization and characterization of a dual-chirped optical parametric amplification (DC-OPA) scheme (2011 Opt. Express 19 7190). By increasing a pump pulse energy to 100 mJ, a total (signal + idler) output energy exceeding 30 mJ was recorded with higher than 30% conversion efficiency. The feasibility of further increasing the output energy to a higher scale using the DC-OPA scheme was confirmed by a proof-of-principle experiment, in which 30%–40% conversion efficiency was observed. The signal pulse with the center wavelength of 1.4 μm was compressed to 27 fs (FWHM), which was very close to a transform-limited pulse duration of 25 fs. Since the DC-OPA scheme is efficient for generating high-energy infrared (IR) pulses with excellent scaling ability, the design parameters for obtaining hundred-mJ-level and even joule-level IR pulses are discussed and presented in detail. (invited article)

  14. Mutually incoherent beam combining through optical parametric amplification

    International Nuclear Information System (INIS)

    Tropheme, B.

    2012-01-01

    This work deals with a technique of combination of coherent beams: Optical Parametric Amplification (OPA) with Multiple Pumps. This technique is used to instantly transfer the energy of several pumps on one beam, without energy storage and thus avoiding thermal effects in the amplifying media. It can be useful to combine energy of numerous fiber lasers and to amplify with a high repetition rate very high energy lasers or broadband pulses. With a numerical and experimental study using BBO and LBO as nonlinear crystal, we determine how to dispose the pumps around the signal and the corresponding angular tolerances of such set up. Then we focus our attention on recombining mechanisms between a pump and a non-corresponding idler. We demonstrate experimentally that these cascading effects may decrease the spatial and spectral quality of the amplified signal, and that these phenomena can be avoided with a minimum angle between the different pumps. A novel modelling of multi-pumps OPA links these cascading effects to the gratings generated by the interaction between the pumps. The last part presents a 5 pump OPA experiment. We achieve a pump-to-signal efficiency of 27% and so that a signal more powerful than each pump is obtained. (author) [fr

  15. Review:Whole genome amplification in preimplantation genetic diagnosis

    Institute of Scientific and Technical Information of China (English)

    Ying-ming ZHENG; Ning WANG; Lei LI; Fan JIN

    2011-01-01

    Preimplantation genetic diagnosis(PGD)refers to a procedure for genetically analyzing embryos prior to implantation,improving the chance of conception for patients at high risk of transmitting specific inherited disorders.This method has been widely used for a large number of genetic disorders since the first successful application in the early 1990s.Polymerase chain reaction(PCR)and fluorescent in situ hybridization(FISH)are the two main methods in PGD,but there are some inevitable shortcomings limiting the scope of genetic diagnosis.Fortunately,different whole genome amplification(WGA)techniques have been developed to overcome these problems.Sufficient DNA can be amplified and multiple tasks which need abundant DNA can be performed.Moreover,WGA products can be analyzed as a template for multi-loci and multi-gene during the subsequent DNA analysis.In this review,we will focus on the currently available WGA techniques and their applications,as well as the new technical trends from WGA products.

  16. A new ultrasonic signal amplification method for detection of bacteria

    Science.gov (United States)

    Kant Shukla, Shiva; Resa López, Pablo; Sierra Sánchez, Carlos; Urréjola, José; Segura, Luis Elvira

    2012-10-01

    A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 105 cells ml-1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity.

  17. Comparison Between Vocal Function Exercises and Voice Amplification.

    Science.gov (United States)

    Teixeira, Letícia Caldas; Behlau, Mara

    2015-11-01

    To compare the effectiveness of vocal function exercises (VFEs) versus voice amplification (VA) after a 6-week therapy for teachers diagnosed with behavioral dysphonia. A total of 162 teachers with behavioral dysphonia were randomly allocated into two intervention groups and one control group (CG). Outcomes were assessed using auditory-perceptual evaluation of voice, laryngeal status assessment, self-ratings of the impact of dysphonia, and acoustic analysis. The VFE group showed effective changes across treatment outcome measures: overall severity of dysphonia relative to the CG, laryngeal evaluation, and self-perceived dysphonia. The VA group showed positive outcomes in some measures of self-rated dysphonia. The CG had poorer outcomes across self-assessment dimensions. The VFE method is effective in treating the behavioral dysphonia of teachers, can change the overall severity and the self-perception of the impact of dysphonia, and the laryngeal evaluation outcomes. The use of a voice amplifier is effective as a preventive measure because it results in an improved self-perception of dysphonia, especially in the work-related dimension. One case of dysphonia aggravation can be prevented in every three patients with behavioral dysphonia engaged in VFE, and one case in every five patients using VA. The lack of a therapeutic intervention worsens teachers' behavioral dysphonia in a period of 6 weeks. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  18. Human minisatellite alleles detectable only after PCR amplification.

    Science.gov (United States)

    Armour, J A; Crosier, M; Jeffreys, A J

    1992-01-01

    We present evidence that a proportion of alleles at two human minisatellite loci is undetected by standard Southern blot hybridization. In each case the missing allele(s) can be identified after PCR amplification and correspond to tandem arrays too short to detect by hybridization. At one locus, there is only one undetected allele (population frequency 0.3), which contains just three repeat units. At the second locus, there are at least five undetected alleles (total population frequency 0.9) containing 60-120 repeats; they are not detected because these tandem repeats give very poor signals when used as a probe in standard Southern blot hybridization, and also cross-hybridize with other sequences in the genome. Under these circumstances only signals from the longest tandemly repeated alleles are detectable above the nonspecific background. The structures of these loci have been compared in human and primate DNA, and at one locus the short human allele containing three repeat units is shown to be an intermediate state in the expansion of a monomeric precursor allele in primates to high copy number in the longer human arrays. We discuss the implications of such loci for studies of human populations, minisatellite isolation by cloning, and the evolution of highly variable tandem arrays.

  19. Period doubling induced by thermal noise amplification in genetic circuits

    KAUST Repository

    Ruocco, G.

    2014-11-18

    Rhythms of life are dictated by oscillations, which take place in a wide rage of biological scales. In bacteria, for example, oscillations have been proven to control many fundamental processes, ranging from gene expression to cell divisions. In genetic circuits, oscillations originate from elemental block such as autorepressors and toggle switches, which produce robust and noise-free cycles with well defined frequency. In some circumstances, the oscillation period of biological functions may double, thus generating bistable behaviors whose ultimate origin is at the basis of intense investigations. Motivated by brain studies, we here study an “elemental” genetic circuit, where a simple nonlinear process interacts with a noisy environment. In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification of environmental fluctuations due to a stochastic resonance of nonlinear origin. This suggests that the period doubling observed in many biological functions might result from the intrinsic interplay between nonlinearity and thermal noise.

  20. Stochastic amplification of fluctuations in cortical up-states.

    Directory of Open Access Journals (Sweden)

    Jorge Hidalgo

    Full Text Available Cortical neurons are bistable; as a consequence their local field potentials can fluctuate between quiescent and active states, generating slow 0.5 2 Hz oscillations which are widely known as transitions between Up and Down States. Despite a large number of studies on Up-Down transitions, deciphering its nature, mechanisms and function are still today challenging tasks. In this paper we focus on recent experimental evidence, showing that a class of spontaneous oscillations can emerge within the Up states. In particular, a non-trivial peak around 20 Hz appears in their associated power-spectra, what produces an enhancement of the activity power for higher frequencies (in the 30-90 Hz band. Moreover, this rhythm within Ups seems to be an emergent or collective phenomenon given that individual neurons do not lock to it as they remain mostly unsynchronized. Remarkably, similar oscillations (and the concomitant peak in the spectrum do not appear in the Down states. Here we shed light on these findings by using different computational models for the dynamics of cortical networks in presence of different levels of physiological complexity. Our conclusion, supported by both theory and simulations, is that the collective phenomenon of "stochastic amplification of fluctuations"--previously described in other contexts such as Ecology and Epidemiology--explains in an elegant and parsimonious manner, beyond model-dependent details, this extra-rhythm emerging only in the Up states but not in the Downs.

  1. An extended parametrization of gas amplification in proportional wire chambers

    International Nuclear Information System (INIS)

    Beingessner, S.P.; Carnegie, R.K.; Hargrove, C.K.

    1987-01-01

    It is normally assumed that the gas amplification in proportional chambers is a function of Townsend's first ionization coefficient, α, and that α is a function of the anode surface electric field only. Experimental measurements are presented demonstrating the breakdown of the latter assumption for electric fields, X, greater than about 150 V/cm/Torr on the anode wire surface for a gas mixture of 80/20 argon/methane. For larger values of X, the parametrization of the proportional gas gain data requires an additional term related to the gradient of the electric field near the wire. This extended gain parametrization remains valid until the onset of nonproportional contributions such as positive ion space charge saturation effects. Furthermore, deviations of the data from this parametrization are used to measure the onset of these space charge effects. A simple scaling dependence of the gain data on the product of pressure and wire radius over the whole proportional range is also demonstrated. (orig.)

  2. A new ultrasonic signal amplification method for detection of bacteria

    International Nuclear Information System (INIS)

    Shukla, Shiva Kant; López, Pablo Resa; Sánchez, Carlos Sierra; Segura, Luis Elvira; Urréjola, José

    2012-01-01

    A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 10 5 cells ml −1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity. (paper)

  3. New insights into siRNA amplification and RNAi.

    Science.gov (United States)

    Zhang, Chi; Ruvkun, Gary

    2012-08-01

    In the nematode Caenorhabditis elegans (C. elegans), gene inactivation by RNA interference can achieve remarkable potency due to the amplification of initial silencing triggers by RNA-dependent RNA polymerases (RdRPs). RdRPs catalyze the biogenesis of an abundant species of secondary small interfering RNAs (siRNAs) using the target mRNA as template. The interaction between primary siRNAs derived from the exogenous double-stranded RNA (dsRNA) trigger and the target mRNA is required for the recruitment of RdRPs. Other genetic requirements for RdRP activities have not been characterized. Recent studies have identified the RDE-10/RDE-11 complex which interacts with the primary siRNA bound target mRNA and acts upstream of the RdRPs. rde-10 and rde-11 mutants show an RNAi defective phenotype because the biogenesis of secondary siRNAs is completely abolished. In addition, the RDE-10/RDE-11 complex plays a similar role in the endogenous RNAi pathway for the biogenesis of a subset of siRNAs targeting recently acquired, duplicated genes.

  4. Risks, media and the social amplification of soil contamination

    Energy Technology Data Exchange (ETDEWEB)

    Ouboter, S. [NOK, Networkorganisation for Environmental Quality, Gouda (Netherlands)

    2003-07-01

    Soil experts think of the risks of contaminated sites in terms of adverse effects of toxic substances on human health or environmental quality. In other words, the risk is attributed to the contamination. Social scientists define risk as a situation or event in which something of human value (including humans themselves) has been put at stake and where the outcome is uncertain. Since situations or events are constructions of the human mind, risks are also constructed. A relevant question for a psychologist is to learn how these constructions evolve in the mind of an individual and how this perceived risk influences the individuals' behaviour and well-being. A relevant question for a sociologist is how individuals with their own perceptions, feelings and behaviour interact. Many soil contamination experts experienced that one a site is seen as contaminated by a loathsome source, a chain of adverse reactions can easily put a stigma on that specific location and groups of people associated with that contaminated site. The case of Love Canal is worldwide known as an example of this phenomenon, but many countries have their own national symbol, like Lekkerkerk in the Netherlands. Modern media play an important role in this process. This process is often believed to be irrational and therefore uncontrollable. The question of this workshop is to what level technical soil experts can influence the psychological and social effects of soil contamination, using the social amplification metaphor. (orig.)

  5. Shaping of picosecond pulses for pumping optical parametric amplification

    International Nuclear Information System (INIS)

    Fueloep, J.A.; Krausz, F.; Major, Zs.; Horvath, B.

    2006-01-01

    Complete test of publication follows. The use of temporally shaped pump pulses for optical parametric amplification (OPA) is expected to facilitate an increase of efficiency and suppression of possible spectral distortions in this process, since the gain sensitively depends on the pump intensity. Our simulations confirmed such beneficial effect of temporally shaped pump pulses on the OPA process. With the aim to realize an optimized OPA stage pumped by shaped pulses, a novel method for passively shaping narrow band picosecond pulses has been developed. The method is based on the pulse-stacking principle, where replicas of the incoming pulse are created in a specially designed four-beam interferometer. The replicas are recombined with appropriate delays. The interferometer design allows for a unique flexibility in varying the pulse shape, since all relevant degrees of freedom, such as relative intensities and delays between the pulse replicas are independently adjustable. According to our calculations a pulse with a flat-top time profile would provide optimal conditions in the OPA process. Usually the pump pulse needs to be amplified in a conventional laser amplifier prior to the OPA. Our cross-correlation measurements showed that we are able to obtain shaped amplified pulses by shaping the amplifier input. Furthermore, by precompensating the distortions introduced by the amplifier we demonstrated our capability to produce amplified pulses with a flat-top time profile.

  6. Interactive Game for Teaching Laser Amplification Used at the National Ignition Facility

    International Nuclear Information System (INIS)

    Lin, E.

    2009-01-01

    The purpose of this project was to create an interactive game to expose high school students to concepts in laser amplification by demonstrating the National Ignition Facility's main amplifier at Lawrence Livermore National Laboratory. To succeed, the game had to be able to communicate effectively the basic concepts of laser amplification as accurately as possible and to be capable of exposing as many students as possible. Since concepts need to be communicated in a way that students understand, the Science Content Standards for California Public Schools were used to make assumptions about high school students knowledge of light. Effectively communicating a new concept necessitates the omission on terminology and symbolism. Therefore, creating a powerful experience was ideal for communicating this material. Various methods of reinforcing this experience ranging from color choice to abstractions kept the student focused on the game to maximize concept retention. The program was created in Java to allow the creation of a Java Applet that can be embedded onto a webpage, which is a perfect medium for mass exposure. Because a game requires interaction, the game animations had to be easily manipulated to enable the program to respond to user input. Image sprites, as opposed to image folders, were used in these animations to minimize the number of Hypertext Transfer Protocol connections, and thus, significantly reduce the transfer time of necessary animation files. These image sprites were loaded and cropped into a list of animation frames. Since the caching of large transition animations caused the Java Virtual Machine to run out of memory, large animations were implemented as animated Graphics Interchange Format images since transitions require no interaction, and thus, no frame manipulation was needed. This reduced the animation's memory footprint. The first version of this game was completed during this project. Future work for the project could include the creation

  7. Interactive Game for Teaching Laser Amplification Used at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Lin, E

    2009-08-06

    The purpose of this project was to create an interactive game to expose high school students to concepts in laser amplification by demonstrating the National Ignition Facility's main amplifier at Lawrence Livermore National Laboratory. To succeed, the game had to be able to communicate effectively the basic concepts of laser amplification as accurately as possible and to be capable of exposing as many students as possible. Since concepts need to be communicated in a way that students understand, the Science Content Standards for California Public Schools were used to make assumptions about high school students knowledge of light. Effectively communicating a new concept necessitates the omission on terminology and symbolism. Therefore, creating a powerful experience was ideal for communicating this material. Various methods of reinforcing this experience ranging from color choice to abstractions kept the student focused on the game to maximize concept retention. The program was created in Java to allow the creation of a Java Applet that can be embedded onto a webpage, which is a perfect medium for mass exposure. Because a game requires interaction, the game animations had to be easily manipulated to enable the program to respond to user input. Image sprites, as opposed to image folders, were used in these animations to minimize the number of Hypertext Transfer Protocol connections, and thus, significantly reduce the transfer time of necessary animation files. These image sprites were loaded and cropped into a list of animation frames. Since the caching of large transition animations caused the Java Virtual Machine to run out of memory, large animations were implemented as animated Graphics Interchange Format images since transitions require no interaction, and thus, no frame manipulation was needed. This reduced the animation's memory footprint. The first version of this game was completed during this project. Future work for the project could include the

  8. c-myc Amplification Is Frequent in Esophageal Adenocarcinoma and Correlated with the Upregulation of VEGF-A Expression

    Directory of Open Access Journals (Sweden)

    Burkhard H.A. von Rahden

    2006-09-01

    Full Text Available BACKGROUND: Deregulation of c-myc plays a major role in the carcinogenesis of human malignancies. We investigated the amplification of the c-myc gene in a surgical series of Barrett cancers. METHODS: Primary resected esophageal (Barrett adenocarcinomas (n = 84 were investigated for c-myc amplification using chromogene in situ hybridization. Tumor samples were assembled in a tissue microarray. c-myc gene dosage was correlated with clinicopathologic parameters, including the survival and gene expression of cyclooxygenases (COX-1 and COX-2 and proangiogenic growth factors (VEGF-A and VEGF-C. RESULTS: The majority (70 of 84; 83.3% exhibited amplification of the c-myc gene. There were low-level amplifications in 63 (75.0% cases and high-level amplifications in 7 (8.3% cases. No amplification was found in 14 (16.7% cases. Tumors without c-myc amplification had lower VEGF-A, VEGF-C, and COX-2 expression levels than tumors with low-level and high-level c-myc amplification (statistically significant for VEGF-A; P = .0348. c-myc amplification was not correlated with clinicopathological parameters or survival. Only diffuse and mixed-type tumors, according to Lauren classification, exhibited c-myc amplifications more frequently (P = .0466. CONCLUSIONS: Amplifications of the c-myc gene are frequent in Barrett cancer. c-myc may be involved in the regulation of angiogenesis.

  9. By-product formation in repetitive PCR amplification of DNA libraries during SELEX.

    Science.gov (United States)

    Tolle, Fabian; Wilke, Julian; Wengel, Jesper; Mayer, Günter

    2014-01-01

    The selection of nucleic acid aptamers is an increasingly important approach to generate specific ligands binding to virtually any molecule of choice. However, selection-inherent amplification procedures are prone to artificial by-product formation that prohibits the enrichment of target-recognizing aptamers. Little is known about the formation of such by-products when employing nucleic acid libraries as templates. We report on the formation of two different forms of by-products, named ladder- and non-ladder-type observed during repetitive amplification in the course of in vitro selection experiments. Based on sequence information and the amplification behaviour of defined enriched nucleic acid molecules we suppose a molecular mechanism through which these amplification by-products are built. Better understanding of these mechanisms might help to find solutions minimizing by-product formation and improving the success rate of aptamer selection.

  10. Somatosensory amplification mediates sex differences in psychological distress among cardioverter-defibrillator patients

    DEFF Research Database (Denmark)

    Versteeg, Henneke; Baumert, Jens; Kolb, Christof

    2010-01-01

    The present study examined whether female patients with an implantable cardioverter defibrillator (ICD) report more psychological distress than male patients, and whether somatosensory amplification mediates this relationship. Design: Consecutive ICD patients (N = 241; 33% women) participating in...

  11. Systematic evaluation of bias in microbial community profiles induced by whole genome amplification.

    NARCIS (Netherlands)

    Direito, S.; Zaura, E.; Little, M.; Ehrenfreund, P.; Roling, W.F.M.

    2014-01-01

    Whole genome amplification methods facilitate the detection and characterization of microbial communities in low biomass environments. We examined the extent to which the actual community structure is reliably revealed and factors contributing to bias. One widely used [multiple displacement

  12. Rapid Newcastle Disease Virus Detection Based on Loop-Mediated Isothermal Amplification and Optomagnetic Readout

    DEFF Research Database (Denmark)

    Tian, Bo; Ma, Jing; Zardán Gómez de la Torre, Teresa

    2016-01-01

    Rapid and sensitive diagnostic methods based on isothermal amplification are ideal substitutes for PCR in out-of-lab settings. However, there are bottlenecks in terms of establishing low-cost and user-friendly readout methods for isothermal amplification schemes. Combining the high amplification...... efficiency of loop-mediated isothermal amplification (LAMP) with an optomagnetic nanoparticle-based readout system, we demonstrate ultrasensitive and rapid detection of Newcastle disease virus RNA. Biotinylated amplicons of LAMP and reverse transcription LAMP (RT-LAMP) bind to streptavidin-coated magnetic...... nanoparticles (MNPs) resulting in a dramatical increase in the hydrodynamic size of the MNPs. This increase was measured by an optomagnetic readout system and provided quantitative information on the amount of LAMP target sequence. Our assay resulted in a limit of detection of 10 aM of target sequence...

  13. Diagnostic Accuracy of Molecular Amplification Tests for Human African Trypanosomiasis-Systematic Review

    NARCIS (Netherlands)

    Mugasa, Claire M.; Adams, Emily R.; Boer, Kimberly R.; Dyserinck, Heleen C.; Büscher, Philippe; Schallig, Henk D. H. F.; Leeflang, Mariska M. G.

    2012-01-01

    Background: A range of molecular amplification techniques have been developed for the diagnosis of Human African Trypanosomiasis (HAT); however, careful evaluation of these tests must precede implementation to ensure their high clinical accuracy. Here, we investigated the diagnostic accuracy of

  14. Amplification of Chirality through Self-Replication of Micellar Aggregates in Water

    KAUST Repository

    Bukhriakov, Konstantin; Almahdali, Sarah; Rodionov, Valentin

    2015-01-01

    We describe a system in which the self-replication of micellar aggregates results in a spontaneous amplification of chirality in the reaction products. In this system, amphiphiles are synthesized from two "clickable" fragments: a water-soluble "head

  15. Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

    Science.gov (United States)

    Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

    2014-01-01

    Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

  16. Parasitic bipolar amplification in a single event transient and its temperature dependence

    International Nuclear Information System (INIS)

    Liu Zheng; Chen Shu-Ming; Chen Jian-Jun; Qin Jun-Rui; Liu Rong-Rong

    2012-01-01

    Using three-dimensional technology computer-aided design (TCAD) simulation, parasitic bipolar amplification in a single event transient (SET) current of a single transistor and its temperature dependence are studied. We quantify the contributions of different current components in a SET current pulse, and it is found that the proportion of parasitic bipolar amplification in total collected charge is about 30% in both 130-nm and 90-nm technologies. The temperature dependence of parasitic bipolar amplification and the mechanism of the SET pulse are also investigated and quantified. The results show that the proportion of charge induced by parasitic bipolar increases with rising temperature, which illustrates that the parasitic bipolar amplification plays an important role in the charge collection of a single transistor

  17. Systematic evaluation of bias in microbial community profiles induced by whole genome amplification

    NARCIS (Netherlands)

    Direito, S.O.L.; Zaura, E.; Little, M.; Ehrenfreund, P.; Röling, W.F.M.

    2014-01-01

    Whole genome amplification methods facilitate the detection and characterization of microbial communities in low biomass environments. We examined the extent to which the actual community structure is reliably revealed and factors contributing to bias. One widely used [multiple displacement

  18. PCR amplification of repetitive sequences as a possible approach in relative species quantification

    DEFF Research Database (Denmark)

    Ballin, Nicolai Zederkopff; Vogensen, Finn Kvist; Karlsson, Anders H

    2012-01-01

    Abstract Both relative and absolute quantifications are possible in species quantification when single copy genomic DNA is used. However, amplification of single copy genomic DNA does not allow a limit of detection as low as one obtained from amplification of repetitive sequences. Amplification...... of repetitive sequences is therefore frequently used in absolute quantification but problems occur in relative quantification as the number of repetitive sequences is unknown. A promising approach was developed where data from amplification of repetitive sequences were used in relative quantification of species...... to relatively quantify the amount of chicken DNA in a binary mixture of chicken DNA and pig DNA. However, the designed PCR primers lack the specificity required for regulatory species control....

  19. Tiny Grains Give Huge Gains: Nanocrystal–Based Signal Amplification for Biomolecule Detection

    Science.gov (United States)

    Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang

    2013-01-01

    Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge gain in signal amplification for biomolecule detection. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays. PMID:23659350

  20. Simultaneous electrical and mechanical resonance drive for large signal amplification of micro resonators

    KAUST Repository

    Hasan, M. H.

    2018-01-12

    Achieving large signal-noise ratio using low levels of excitation signal is key requirement for practical applications of micro and nano electromechanical resonators. In this work, we introduce the double electromechanical resonance drive concept to achieve an order-of-magnitude dynamic signal amplification in micro resonators. The concept relies on simultaneously activating the micro-resonator mechanical and electrical resonance frequencies. We report an input voltage amplification up to 15 times for a micro-resonator when its electrical resonance is tuned to match the mechanical resonance that leads to dynamic signal amplification in air (Quality factor enhancement). Furthermore, using a multi-frequency excitation technique, input voltage and vibrational amplification of up to 30 times were shown for the same micro-resonator while relaxing the need to match its mechanical and electrical resonances.

  1. Envelope matching for enhanced backward Raman amplification by using self-ionizing plasmas

    International Nuclear Information System (INIS)

    Zhang, Z. M.; Zhang, B.; Hong, W.; Teng, J.; He, S. K.; Gu, Y. Q.; Yu, M. Y.

    2014-01-01

    Backward Raman amplification (BRA) in plasmas has been promoted as a means for generating ultrapowerful laser pulses. For the purpose of achieving the maximum intensities over the shortest distances, an envelope matching between the seed pulse and the amplification gain is required, i.e., the seed pulse propagates at the same velocity with the gain such that the peak of the seed pulse can always enjoy the maximum gain. However, such an envelope matching is absent in traditional BRA because in the latter the amplification gain propagates at superluminous velocity while the seed pulse propagates at the group velocity, which is less than the speed of light. It is shown here that, by using self-ionizing plasmas, the speed of the amplification gain can be well reduced to reach the envelope matching regime. This results in a favorable BRA process, in which higher saturated intensity, shorter interaction length and higher energy-transfer efficiency are achieved

  2. High peak-power kilohertz laser system employing single-stage multi-pass amplification

    Science.gov (United States)

    Shan, Bing; Wang, Chun; Chang, Zenghu

    2006-05-23

    The present invention describes a technique for achieving high peak power output in a laser employing single-stage, multi-pass amplification. High gain is achieved by employing a very small "seed" beam diameter in gain medium, and maintaining the small beam diameter for multiple high-gain pre-amplification passes through a pumped gain medium, then leading the beam out of the amplifier cavity, changing the beam diameter and sending it back to the amplifier cavity for additional, high-power amplification passes through the gain medium. In these power amplification passes, the beam diameter in gain medium is increased and carefully matched to the pump laser's beam diameter for high efficiency extraction of energy from the pumped gain medium. A method of "grooming" the beam by means of a far-field spatial filter in the process of changing the beam size within the single-stage amplifier is also described.

  3. Simultaneous electrical and mechanical resonance drive for large signal amplification of micro resonators

    KAUST Repository

    Hasan, M. H.; Alsaleem, F. M.; Jaber, Nizar; Hafiz, Md Abdullah Al; Younis, Mohammad I.

    2018-01-01

    Achieving large signal-noise ratio using low levels of excitation signal is key requirement for practical applications of micro and nano electromechanical resonators. In this work, we introduce the double electromechanical resonance drive concept to achieve an order-of-magnitude dynamic signal amplification in micro resonators. The concept relies on simultaneously activating the micro-resonator mechanical and electrical resonance frequencies. We report an input voltage amplification up to 15 times for a micro-resonator when its electrical resonance is tuned to match the mechanical resonance that leads to dynamic signal amplification in air (Quality factor enhancement). Furthermore, using a multi-frequency excitation technique, input voltage and vibrational amplification of up to 30 times were shown for the same micro-resonator while relaxing the need to match its mechanical and electrical resonances.

  4. PCR amplification of Bartonella koehlerae from human blood and enrichment blood cultures

    Directory of Open Access Journals (Sweden)

    Breitschwerdt Edward B

    2010-08-01

    Full Text Available Abstract Background Cats appear to be the primary reservoir host for Bartonella koehlerae, an alpha Proteobacteria that is most likely transmitted among cat populations by fleas (Ctenocephalides felis. Bartonella koehlerae has caused endocarditis in a dog and in one human patient from Israel, but other clinically relevant reports involving this bacterium are lacking. Despite publication of numerous, worldwide epidemiological studies designed to determine the prevalence of Bartonella spp. bacteremia in cats, B. koehlerae has never been isolated using conventional blood agar plates. To date, successful isolation of B. koehlerae from cats and from the one human endocarditis patient has consistently required the use of chocolate agar plates. Results In this study, Bartonella koehlerae bacteremia was documented in eight immunocompetent patients by PCR amplification and DNA sequencing, either prior to or after enrichment blood culture using Bartonella alpha Proteobacteria growth medium. Presenting symptoms most often included fatigue, insomnia, joint pain, headache, memory loss, and muscle pain. Four patients were also infected with Bartonella vinsonii subsp. berkhoffii genotype II. After molecular documentation of B. koehlerae infection in these patients, a serological test was developed and serum samples were tested retrospectively. Bartonella koehlerae antibodies were not detected (titers B. koehlerae antibody titers of 1:64 or greater. Conclusions Although biased by a study population consisting of individuals with extensive arthropod and animal exposure, the results of this study suggest that B. koehlerae bacteremia is more common in immunocompetent people than has been previously suspected. Future studies should more thoroughly define modes of transmission and risk factors for acquiring infection with B. koehlerae. In addition, studies are needed to determine if B. koehlerae is a cause or cofactor in the development of arthritis, peripheral

  5. Specific detection of Pectobacterium carotovorum by loop-mediated isothermal amplification.

    Science.gov (United States)

    Yasuhara-Bell, Jarred; Marrero, Glorimar; De Silva, Asoka; Alvarez, Anne M

    2016-12-01

    Potatoes are an important agroeconomic crop worldwide and maceration diseases caused by pectolytic bacterial pathogens result in significant pre- and post-harvest losses. Pectobacterium carotovorum shares a common host range with other Pectobacterium spp. and other members of the Enterobacteriaceae, such as Dickeya spp. As these pathogens cannot be clearly differentiated on the basis of the symptoms they cause, improved methods of identification are critical for the determination of sources of contamination. Current standardized methods for the differentiation of pectolytic species are time consuming and require trained personnel, as they rely on traditional bacteriological practices that do not always produce conclusive results. In this growing world market, there is a need for rapid diagnostic tests that can differentiate between pectolytic pathogens, as well as separate them from non-pectolytic enteric bacteria associated with soft rots of potato. An assay has been designed previously to detect the temperate pathogen Pectobacterium atrosepticum, but there is currently no recognized rapid assay for the detection of the tropical/subtropical counterpart, Pectobacterium carotovorum. This report describes the development of a loop-mediated isothermal amplification (LAMP) assay that detects P. carotovorum with high specificity. The assay was evaluated using all known species of Pectobacterium and only showed positive reactions for P. carotovorum. This assay was also tested against 15 non-target genera of plant-associated bacteria and did not produce any false positives. The LAMP assay described here can be used as a rapid test for the differentiation of P. carotovorum from other pectolytic pathogens, and its gene target can be the basis for the development of other molecular-based detection assays. © 2016 BSPP and John Wiley & Sons Ltd.

  6. Examination of the site amplification factor of OBS and their application to magnitude estimation and ground-motion prediction for EEW

    Science.gov (United States)

    Hayashimoto, N.; Hoshiba, M.

    2013-12-01

    1. Introduction Ocean bottom seismograph (OBS) is useful for making Earthquake Early Warning (EEW) earlier. However, careful handling of these data is required because the installation environment of OBSs may be different from that of land stations. Site amplification factor is an important factor to estimate the magnitudes, and to predict ground motions (e.g. seismic intensity) in EEW. In this presentation, we discuss the site amplification factor of OBS in the Tonankai area of Japan from these two points of view. 2. Examination of magnitude correction of OBS In the EEW of JMA, the magnitude is estimated from the maximum amplitude of the displacement in real time. To provide the fast magnitude estimation, the magnitude-estimation algorithm switches from the P to S formula (Meew(P) to Meew(S)) depending on the expected S-phase arrival (Kamigaichi,2004). To estimate the magnitude correction for OBS, we determine Meew(P) and Meew(S) at OBSs and compare them with JMA magnitude (Mjma). We find Meew(S) at OBS is generally larger than Mjma by approximately 0.6. The slight differences of spatial distribution of Meew(S) amplification are also found among other OBSs. From the numerical simulations, Nakamura et al. (MGR,submitted) pointed out that the oceanic layer and the low-velocity sediment layers causes the large amplifications in low frequency range (0.1-0.2Hz) at OBSs. We conclude that the site effect of OBS characterized by such a low velocity sediment layers causes those amplification of Magnitude. 3. The frequency-dependent site factor of OBS estimated from Fourier spectrum ratio and their application for prediction of seismic intensity of land station We compare Fourier spectra of S-wave portion on OBSs with those on adjacent land stations. Station pair whose distance is smaller than 50 km is analyzed, and we obtain that spectral ratio of land station (MIEH05 of the KiK-net/NIED) to OBS (KMA01 of the DONET/JAMSTEC) is 5-20 for frequencies 10-20Hz for both

  7. Real-time sequence-validated loop-mediated isothermal amplification assays for detection of Middle East respiratory syndrome coronavirus (MERS-CoV.

    Directory of Open Access Journals (Sweden)

    Sanchita Bhadra

    Full Text Available The Middle East respiratory syndrome coronavirus (MERS-CoV, an emerging human coronavirus, causes severe acute respiratory illness with a 35% mortality rate. In light of the recent surge in reported infections we have developed asymmetric five-primer reverse transcription loop-mediated isothermal amplification (RT-LAMP assays for detection of MERS-CoV. Isothermal amplification assays will facilitate the development of portable point-of-care diagnostics that are crucial for management of emerging infections. The RT-LAMP assays are designed to amplify MERS-CoV genomic loci located within the open reading frame (ORF1a and ORF1b genes and upstream of the E gene. Additionally we applied one-step strand displacement probes (OSD for real-time sequence-specific verification of LAMP amplicons. Asymmetric amplification effected by incorporating a single loop primer in each assay accelerated the time-to-result of the OSD-RT-LAMP assays. The resulting assays could detect 0.02 to 0.2 plaque forming units (PFU (5 to 50 PFU/ml of MERS-CoV in infected cell culture supernatants within 30 to 50 min and did not cross-react with common human respiratory pathogens.

  8. Visual detection of West Nile virus using reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip

    Directory of Open Access Journals (Sweden)

    Zengguo eCao

    2016-04-01

    Full Text Available West Nile virus (WNV causes a severe zoonosis, which can lead to a large number of casualties and considerable economic losses. A rapid and accurate identification methodfor WNV for use in field laboratories is urgently needed. Here, a method utilizing reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip (RT-LAMP-VF was developed to detect the envelope (E gene of WNV. The RT-LAMP-VF assay could detect 102 copies/μl ofan WNV RNA standard using a 40 min amplification reaction followed by a 2 min incubationof the amplification product on the visualization strip, and no cross-reaction with other closely related members of theFlavivirus genus was observed. The assay was further evaluated using cells and mouse brain tissues infected with a recombinant rabies virus expressing the E protein of WNV.The assay produced sensitivities of 101.5TCID50/ml and 101.33 TCID50/ml for detection of the recombinant virus in the cells and brain tissues, respectively. Overall, the RT-LAMP-VF assay developed in this study is rapid, simple and effective, and it is therefore suitable for clinical application in the field.

  9. Target recycling amplification for label-free and sensitive colorimetric detection of adenosine triphosphate based on un-modified aptamers and DNAzymes.

    Science.gov (United States)

    Gong, Xue; Li, Jinfu; Zhou, Wenjiao; Xiang, Yun; Yuan, Ruo; Chai, Yaqin

    2014-05-30

    Based on target recycling amplification, the development of a new label-free, simple and sensitive colorimetric detection method for ATP by using un-modified aptamers and DNAzymes is described. The association of the model target molecules (ATP) with the corresponding aptamers of the dsDNA probes leads to the release of the G-quadruplex sequences. The ATP-bound aptamers can be further degraded by Exonuclease III to release ATP, which can again bind the aptamers of the dsDNA probes to initiate the target recycling amplification process. Due to this target recycling amplification, the amount of the released G-quadruplex sequences is significantly enhanced. Subsequently, these G-quadruplex sequences bind hemin to form numerous peroxidase mimicking DNAzymes, which cause substantially intensified color change of the probe solution for highly sensitive colorimetric detection of ATP down to the sub-nanomolar (0.33nM) level. Our method is highly selective toward ATP against other control molecules and can be performed in one single homogeneous solution, which makes our sensing approach hold great potential for sensitive colorimetric detection of other small molecules and proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Competing for Iron: Duplication and Amplification of the isd Locus in Staphylococcus lugdunensis HKU09-01 Provides a Competitive Advantage to Overcome Nutritional Limitation.

    Science.gov (United States)

    Heilbronner, Simon; Monk, Ian R; Brozyna, Jeremy R; Heinrichs, David E; Skaar, Eric P; Peschel, Andreas; Foster, Timothy J

    2016-08-01

    Staphylococcus lugdunensis is a coagulase negative bacterial pathogen that is particularly associated with severe cases of infectious endocarditis. Unique amongst the coagulase-negative staphylococci, S. lugdunensis harbors an iron regulated surface determinant locus (isd). This locus facilitates the acquisition of heme as a source of nutrient iron during infection and allows iron limitation caused by "nutritional immunity" to be overcome. The isd locus is duplicated in S. lugdunensis HKU09-01 and we show here that the duplication is intrinsically unstable and undergoes accordion-like amplification and segregation leading to extensive isd copy number variation. Amplification of the locus increased the level of expression of Isd proteins and improved binding of hemoglobin to the cell surface of S. lugdunensis. Furthermore, Isd overexpression provided an advantage when strains were competing for a limited amount of hemoglobin as the sole source of iron. Gene duplications and amplifications (GDA) are events of fundamental importance for bacterial evolution and are frequently associated with antibiotic resistance in many species. As such, GDAs are regarded as evolutionary adaptions to novel selective pressures in hostile environments pointing towards a special importance of isd for S. lugdunensis. For the first time we show an example of a GDA that involves a virulence factor of a Gram-positive pathogen and link the GDA directly to a competitive advantage when the bacteria were struggling with selective pressures mimicking "nutritional immunity".

  11. Competing for Iron: Duplication and Amplification of the isd Locus in Staphylococcus lugdunensis HKU09-01 Provides a Competitive Advantage to Overcome Nutritional Limitation

    Science.gov (United States)

    Heilbronner, Simon; Brozyna, Jeremy R.; Heinrichs, David E.; Skaar, Eric P.; Peschel, Andreas; Foster, Timothy J.

    2016-01-01

    Staphylococcus lugdunensis is a coagulase negative bacterial pathogen that is particularly associated with severe cases of infectious endocarditis. Unique amongst the coagulase-negative staphylococci, S. lugdunensis harbors an iron regulated surface determinant locus (isd). This locus facilitates the acquisition of heme as a source of nutrient iron during infection and allows iron limitation caused by “nutritional immunity” to be overcome. The isd locus is duplicated in S. lugdunensis HKU09-01 and we show here that the duplication is intrinsically unstable and undergoes accordion-like amplification and segregation leading to extensive isd copy number variation. Amplification of the locus increased the level of expression of Isd proteins and improved binding of hemoglobin to the cell surface of S. lugdunensis. Furthermore, Isd overexpression provided an advantage when strains were competing for a limited amount of hemoglobin as the sole source of iron. Gene duplications and amplifications (GDA) are events of fundamental importance for bacterial evolution and are frequently associated with antibiotic resistance in many species. As such, GDAs are regarded as evolutionary adaptions to novel selective pressures in hostile environments pointing towards a special importance of isd for S. lugdunensis. For the first time we show an example of a GDA that involves a virulence factor of a Gram-positive pathogen and link the GDA directly to a competitive advantage when the bacteria were struggling with selective pressures mimicking “nutritional immunity”. PMID:27575058

  12. Zebrafish tissue injury causes upregulation of interleukin-1 and caspase-dependent amplification of the inflammatory response

    Directory of Open Access Journals (Sweden)

    Nikolay V. Ogryzko

    2014-02-01

    Full Text Available Interleukin-1 (IL-1, the ‘gatekeeper’ of inflammation, is the apical cytokine in a signalling cascade that drives the early response to injury or infection. Expression, processing and secretion of IL-1 are tightly controlled, and dysregulated IL-1 signalling has been implicated in a number of pathologies ranging from atherosclerosis to complications of infection. Our understanding of these processes comes from in vitro monocytic cell culture models as lines or primary isolates, in which a range and spectra of IL-1 secretion mechanisms have been described. We therefore investigated whether zebrafish embryos provide a suitable in vivo model for studying IL-1-mediated inflammation. Structurally, zebrafish IL-1β shares a β-sheet-rich trefoil structure with its human counterpart. Functionally, leukocyte expression of IL-1β was detectable only following injury, which activated leukocytes throughout zebrafish embryos. Migration of macrophages and neutrophils was attenuated by inhibitors of either caspase-1 or P2X7, which similarly inhibited the activation of NF-κB at the site of injury. Zebrafish offer a new and versatile model to study the IL-1β pathway in inflammatory disease and should offer unique insights into IL-1 biology in vivo.

  13. Zebrafish tissue injury causes upregulation of interleukin-1 and caspase-dependent amplification of the inflammatory response.

    Science.gov (United States)

    Ogryzko, Nikolay V; Hoggett, Emily E; Solaymani-Kohal, Sara; Tazzyman, Simon; Chico, Timothy J A; Renshaw, Stephen A; Wilson, Heather L

    2014-02-01

    Interleukin-1 (IL-1), the 'gatekeeper' of inflammation, is the apical cytokine in a signalling cascade that drives the early response to injury or infection. Expression, processing and secretion of IL-1 are tightly controlled, and dysregulated IL-1 signalling has been implicated in a number of pathologies ranging from atherosclerosis to complications of infection. Our understanding of these processes comes from in vitro monocytic cell culture models as lines or primary isolates, in which a range and spectra of IL-1 secretion mechanisms have been described. We therefore investigated whether zebrafish embryos provide a suitable in vivo model for studying IL-1-mediated inflammation. Structurally, zebrafish IL-1β shares a β-sheet-rich trefoil structure with its human counterpart. Functionally, leukocyte expression of IL-1β was detectable only following injury, which activated leukocytes throughout zebrafish embryos. Migration of macrophages and neutrophils was attenuated by inhibitors of either caspase-1 or P2X7, which similarly inhibited the activation of NF-κB at the site of injury. Zebrafish offer a new and versatile model to study the IL-1β pathway in inflammatory disease and should offer unique insights into IL-1 biology in vivo.

  14. 10 Gb/s bidirectional single fibre long reach PON link with distributed Raman amplification

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Kjær, Rasmus; Jeppesen, Palle

    2006-01-01

    We report operation of a single fibre bidirectional 80 km long reach PON link with symmetric up- and-downstream data rate of 10 Gb/s supported by distributed Raman fibre amplification only.......We report operation of a single fibre bidirectional 80 km long reach PON link with symmetric up- and-downstream data rate of 10 Gb/s supported by distributed Raman fibre amplification only....

  15. New closed tube loop mediated isothermal amplification assay for prevention of product cross-contamination

    OpenAIRE

    Karthik, K.; Rathore, Rajesh; Thomas, Prasad; Arun, T.R.; Viswas, K.N.; Dhama, Kuldeep; Agarwal, R.K.

    2014-01-01

    Loop mediated isothermal amplification (LAMP) assay, a promising diagnostic test, has been developed for detection of different pathogens of human as well as animals. Various positive points support its use as a field level test but the major problem is product cross contamination leading to false positive results. Different methods were adopted by various researchers to control this false positive amplification due to cross contamination but all have their own advantages and disadvantages. A...

  16. Detection of biological molecules using boronate-based chemical amplification and optical sensors

    Science.gov (United States)

    Van Antwerp, William Peter; Mastrototaro, John Joseph; Lane, Stephen M.; Satcher, Jr., Joe H.; Darrow, Christopher B.; Peyser, Thomas A.; Harder, Jennifer

    1999-01-01

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.

  17. Efficient chirped-pulse amplification of sub-20 fs laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Shinichi; Yamakawa, Koichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    We have developed a model for ultrabroadband and ultrashort pulse amplification including the effects of a pulse shaper for regenerative pulse shaping, gain narrowing and gain saturation in the amplifiers. Thin solid etalons are used to control both gain narrowing and gain saturation during amplification. This model has been used to design an optimized Ti:sapphire amplifier system for producing efficiently pulses of < 20-fs duration with approaching peak and average powers of 100 TW and 20 W. (author)

  18. Fiber Optical Parametric Chirped Pulse Amplification of Sub-Picosecond Pulses

    DEFF Research Database (Denmark)

    Cristofori, Valentina; Lali-Dastjerdi, Zohreh; Da Ros, Francesco

    2013-01-01

    We demonstrate experimentally, for the first time to our knowledge, fiber optical parametric chirped pulse amplification of 400-fs pulses. The 400-fs signal is stretched, amplified by 26 dB and compressed back to 500 fs.......We demonstrate experimentally, for the first time to our knowledge, fiber optical parametric chirped pulse amplification of 400-fs pulses. The 400-fs signal is stretched, amplified by 26 dB and compressed back to 500 fs....

  19. A PCA3 gene-based transcriptional amplification system targeting primary prostate cancer

    OpenAIRE

    Neveu, Bertrand; Jain, Pallavi; T?tu, Bernard; Wu, Lily; Fradet, Yves; Pouliot, Fr?d?ric

    2015-01-01

    Targeting specifically primary prostate cancer (PCa) cells for immune therapy, gene therapy or molecular imaging is of high importance. The PCA3 long non-coding RNA is a unique PCa biomarker and oncogene that has been widely studied. This gene has been mainly exploited as an accurate diagnostic urine biomarker for PCa detection. In this study, the PCA3 promoter was introduced into a new transcriptional amplification system named the 3-Step Transcriptional Amplification System (PCA3-3STA) and ...

  20. Rapid and Sensitive Isothermal Detection of Nucleic-acid Sequence by Multiple Cross Displacement Amplification

    OpenAIRE

    Yi Wang; Yan Wang; Ai-Jing Ma; Dong-Xun Li; Li-Juan Luo; Dong-Xin Liu; Dong Jin; Kai Liu; Chang-Yun Ye

    2015-01-01

    We have devised a novel amplification strategy based on isothermal strand-displacement polymerization reaction, which was termed multiple cross displacement amplification (MCDA). The approach employed a set of ten specially designed primers spanning ten distinct regions of target sequence and was preceded at a constant temperature (61?65??C). At the assay temperature, the double-stranded DNAs were at dynamic reaction environment of primer-template hybrid, thus the high concentration of primer...

  1. A subset of herpes simplex virus replication genes induces DNA amplification within the host cell genome

    Energy Technology Data Exchange (ETDEWEB)

    Heilbronn, R.; zur Hausen, H. (Deutsches Krebsforschungszentrum, Heidelberg (West Germany))

    1989-09-01

    Herpes simplex virus (HSV) induces DNA amplification of target genes within the host cell chromosome. To characterize the HSV genes that mediate the amplification effect, combinations of cloned DNA fragments covering the entire HSV genome were transiently transfected into simian virus 40 (SV40)-transformed hamster cells. This led to amplification of the integrated SV40 DNA sequences to a degree comparable to that observed after transfection of intact virion DNA. Transfection of combinations of subclones and of human cytomegalovirus immediate-early promoter-driven expression constructs for individual open reading frames led to the identification of sic HSV genes which together were necessary and sufficient for the induction of DNA amplification: UL30 (DNA polymerase), UL29 (major DNA-binding protein), UL5, UL8, UL42, and UL52. All of these genes encode proteins necessary for HSV DNA replication. However, an additional gene coding for an HSV origin-binding protein (UL9) was required for origin-dependent HSV DNA replication but was dispensable for SV40 DNA amplification. The results show that a subset of HSV replication genes is sufficient for the induction of DNA amplification. This opens the possibility that HSV expresses functions sufficient for DNA amplification but separate from those responsible for lytic viral growth. HSV infection may thereby induce DNA amplification within the host cell genome without killing the host by lytic viral growth. This may lead to persistence of a cell with a new genetic phenotype, which would have implications for the pathogenicity of the virus in vivo.

  2. Amplification and displacement of chaotic attractors by means of unidirectional chaotic driving

    Science.gov (United States)

    González-Miranda, J. M.

    1998-06-01

    Chaotic systems, when used to drive copies of themselves (or parts of themselves) may induce interesting behaviors in the driven system. In case the later exhibits invariance under amplification or translation, they may show amplification (reduction), or displacement of the attractor. It is shown how the behavior to be obtained is implied by the symmetries involved. Two explicit examples are studied to show how these phenomena manifest themselves under perfect and imperfect coupling.

  3. Genetic diagnosis of Duchenne and Becker muscular dystrophy using multiplex ligation-dependent probe amplification in Rwandan patients.

    Science.gov (United States)

    Uwineza, Annette; Hitayezu, Janvier; Murorunkwere, Seraphine; Ndinkabandi, Janvier; Kalala Malu, Celestin Kaputu; Caberg, Jean Hubert; Dideberg, Vinciane; Bours, Vincent; Mutesa, Leon

    2014-04-01

    Duchenne and Becker muscular dystrophies are the most common clinical forms of muscular dystrophies. They are genetically X-linked diseases caused by a mutation in the dystrophin (DMD) gene. A genetic diagnosis was carried out in six Rwandan patients presenting a phenotype of Duchenne and Becker muscular dystrophies and six asymptomatic female carrier relatives using multiplex ligation-dependent probe amplification (MLPA). Our results revealed deletion of the exons 48-51 in one patient, an inherited deletion of the exons 8-21 in two brothers and a de novo deletion of the exons 46-50 in the fourth patient. No copy number variation was found in two patients. Only one female carrier presented exon deletion in the DMD gene. This is the first cohort of genetic analysis in Rwandan patients affected by Duchenne and Becker muscular dystrophies. This report confirmed that MLPA assay can be easily implemented in low-income countries.

  4. Disintegration of cruciform and G-quadruplex structures during the course of helicase-dependent amplification (HDA).

    Science.gov (United States)

    Li, Dawei; Lv, Bei; Zhang, Hao; Lee, Jasmine Yiqin; Li, Tianhu

    2015-04-15

    Unlike chemical damages on DNA, physical alterations of B-form of DNA occur commonly in organisms that serve as signals for specified cellular events. Although the modes of action for repairing of chemically damaged DNA have been well studied nowadays, the repairing mechanisms for physically altered DNA structures have not yet been understood. Our current in vitro studies show that both breakdown of stable non-B DNA structures and resumption of canonical B-conformation of DNA can take place during the courses of isothermal helicase-dependent amplification (HDA). The pathway that makes the non-B DNA structures repairable is presumably the relieving of the accumulated torsional stress that was caused by the positive supercoiling. Our new findings suggest that living organisms might have evolved this distinct and economical pathway for repairing their physically altered DNA structures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Rf power amplification by energy storage and switching

    International Nuclear Information System (INIS)

    Vernon, W.

    1989-01-01

    This paper reports that during the last decade there have been several suggestions for RF storage and switching schemes. The principle behind these schemes is simply that energy from a source which is on for a long time at moderate power can be stored in a resonant cavity and dumped (switched) in a short time to yield higher power. This is also the basis of SLED which is driving the SLC, but the major difference is in the switching and the proposed power gains. In the case of SLED there is no switch only a phase agile RF source, and the maximum power gain is about a factor of 3. Proposed storage and switching schemes are often based on large ratios of charge to discharge times, say 5 μsec/50 nsec = 100 which could be the power amplification ratio. An early demonstration of the switching of a superconducting cavity was reported. It was observed that a peak power gain of 9 at low power levels with a cold cavity and a room-temperature switch. The switch was a He gas filled tube positioned in the leg of a waveguide T so that a η/2 stub turned into a η/4 stub when the gas broke down and became a good conductor. All switches encountered to date are some variant of this technique; the stubs reflects back an out-of-phase signal which cancels the one from the cavity so that no power escapes while the low-loss dielectric tube is non-conducting

  6. Cognitive functions of intracellular mechanisms for contextual amplification.

    Science.gov (United States)

    Phillips, William A

    2017-03-01

    Evidence for the hypothesis that input to the apical tufts of neocortical pyramidal cells plays a central role in cognition by amplifying their responses to feedforward input is reviewed. Apical tufts are electrically remote from the soma, and their inputs come from diverse sources including direct feedback from higher cortical regions, indirect feedback via the thalamus, and long-range lateral connections both within and between cortical regions. This suggests that input to tuft dendrites may amplify the cell's response to basal inputs that they receive via layer 4 and which have synapses closer to the soma. ERP data supporting this inference is noted. Intracellular studies of apical amplification (AA) and of disamplification by inhibitory interneurons targeted only at tufts are reviewed. Cognitive processes that have been related to them by computational, electrophysiological, and psychopathological studies are then outlined. These processes include: figure-ground segregation and Gestalt grouping; contextual disambiguation in perception and sentence comprehension; priming; winner-take-all competition; attention and working memory; setting the level of consciousness; cognitive control; and learning. It is argued that theories in cognitive neuroscience should not assume that all neurons function as integrate-and-fire point processors, but should use the capabilities of cells with distinct sites of integration for driving and modulatory inputs. Potentially 'unifying' theories that depend upon these capabilities are reviewed. It is concluded that evolution of the primitives of AA and disamplification in neocortex may have extended cognitive capabilities beyond those built from the long-established primitives of excitation, inhibition, and disinhibition. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. PARAMETRIC AMPLIFICATION OF THE SIGNALS IN THE ELECTROSTATIC GRAVIINERTIAL SENSOR

    Directory of Open Access Journals (Sweden)

    I. Z. Gilavdary

    2017-01-01

    Full Text Available The challenges of designing simple, reliable, and high sensitivity graviinertial sensors are investigated. The sensor comprises a proof mass (PM and is fixed with the housing by the elastic torsion suspension. PM makes small rotations under the action of gravitational forces or inertial forces.The distinctive features of the sensor are that the differential electrostatic system provides simultaneous reading of the desired signal and a control the torsional rigidity of suspension. In addition, the PM's rotational angular velocity transforms in the alternating current flowing through the capacitors. The presence of аlternating current (AC voltage sources allows to get the parametric amplification of AC and significantly to improve the sensitivity of the sensor. In the simplest case, the sensor does not contain any feedback circuits.As an example, calculations of the micromechanical linear accelerations confirm that the periodic modulation of the coefficient of elastic stiffness of the suspension can significantly increase the sensitivity in the low frequency range, even in the absence of parametric resonance.Conditions for suppressions of background current participating in the output signal from a parametric pumping due to the asymmetry of the differential circuits are set. The frequency characteristics calculations of the sensor were carried out. It is expected, that the proposed sensor design ensures minimum noise level, which can be achievable in the graviinertial sensors. This design and the constructed theory can serve as a basis for creating a wide range of graviinertial devices operating on a movable base, for example, linear and angular accelerometer, gravity gradiometer, gravimeters, and inclinometers, which can be realized in the hybrid and in the micromechanical versions.

  8. Ultrasmall volume molecular isothermal amplification in microfluidic chip with advanced surface processing

    International Nuclear Information System (INIS)

    Huang Guoliang; Yang Xiaoyong; Ma Li; Yang Xu

    2011-01-01

    In this paper, we developed a metal micro-fluidic chip with advanced surface processing for ultra-small volume molecular isothermal amplification. This method takes advantages of the nucleic acid amplification with good stability and consistency, high sensitivity about 31 genomic DNA copies and bacteria specific gene identification. Based on the advanced surface processing, the bioreaction assays of nucleic acid amplification was dropped about 392nl in volume. A high numerical aperture confocal optical detection system was advanced to sensitively monitor the DNA amplification with low noise and high power collecting fluorescence near to the optical diffraction limit. A speedy nucleic acid isothermal amplification was performed in the ultra-small volume microfluidic chip, where the time at the inflexions of second derivative to DNA exponential amplified curves was brought forward and the sensitivity was improved about 65 folds to that of in current 25μl Ep-tube amplified reaction, which indicates a promising clinic molecular diagnostics in the droplet amplification.

  9. HER2 gene amplification in patients with prostate cancer: Evaluating a CISH-based method.

    Science.gov (United States)

    Sharifi, Nazanin; Salmaninejad, Arash; Ferdosi, Samira; Bajestani, Abolfazl Nesaei; Khaleghiyan, Malihe; Estiar, Mehrdad Asghari; Jamali, Mansour; Nowroozi, Mohammad Reza; Shakoori, Abbas

    2016-12-01

    Prostate cancer (PCa) is one of the most widespread malignancies in the world. The role of the human epidermal growth factor receptor 2 (HER2) in the pathogenesis and progression of human PCa remains poorly understood. In contradiction with breast cancer, studies on HER2 overexpression and gene amplification in PCa have produced varying results, although the HER2 oncogene has been implicated in the biology of numerous tumor types, and serves as a prognostic marker and therapeutic target in breast cancer. Technical challenges are considered the main reasons for data discrepancies. Amplification of the HER2 gene has previously been reported in PCa, in which it was associated with tumor progression. The present study aimed to evaluate the prevalence and clinical significance of HER2 amplification in PCa. A total of 32 biopsy samples obtained from human prostate adenocarcinomas were evaluated by chromogenic in situ hybridization (CISH) to determine the frequency of patients with HER2 gene amplifications. High copy numbers of HER2 were detected in 19 of the prostate tumors analyzed. The results of the present study suggested that, in patients without amplification of HER2, high levels of prostate-specific antigen or a high Gleason score were not significantly correlated with a high pathologic stage. Furthermore, amplification levels of the HER2 gene were directly associated with pathologic stage in patients with PCa. Therefore, the potential use of HER2 as a prognostic factor or therapeutic target for PCa warrants further study.

  10. Particle-in-cell Simulations of Raman Laser Amplification in Preformed Plasmas

    International Nuclear Information System (INIS)

    Clark, Daniel S.; Fisch, Nathaniel J.

    2003-01-01

    Two critical issues in the amplification of laser pulses by backward Raman scattering in plasma slabs are the saturation mechanism of the amplification effect (which determines the maximum attainable output intensity of a Raman amplifier) and the optimal plasma density for amplification. Previous investigations [V.M. Malkin, et al., Phys. Rev. Lett., 82 (22):4448-4451, 1999] identified forward Raman scattering and modulational instabilities of the amplifying seed as the likely saturation mechanisms and lead to an estimated unfocused output intensities of 10 17 W/cm 2 . The optimal density for amplification is determined by the competing constraints of minimizing the plasma density so as to minimize the growth rate of the instabilities leading to saturation but also maintaining the plasma sufficiently dense that the driven Langmuir wave responsible for backscattering does not break prematurely. Here, particle-in-cell code are simulations presented which verify that saturation of backward Raman amplification does occur at intensities of ∼10 17 W/cm 2 by forward Raman scattering and modulational instabilities. The optimal density for amplification in a plasma with the representative temperature of T(sub)e = 200 eV is also shown in these simulations to be intermediate between the cold plasma wave-breaking density and the density limit found by assuming a water bag electron distribution function

  11. Real-time electrochemical monitoring of isothermal helicase-dependent amplification of nucleic acids.

    Science.gov (United States)

    Kivlehan, Francine; Mavré, François; Talini, Luc; Limoges, Benoît; Marchal, Damien

    2011-09-21

    We described an electrochemical method to monitor in real-time the isothermal helicase-dependent amplification of nucleic acids. The principle of detection is simple and well-adapted to the development of portable, easy-to-use and inexpensive nucleic acids detection technologies. It consists of monitoring a decrease in the electrochemical current response of a reporter DNA intercalating redox probe during the isothermal DNA amplification. The method offers the possibility to quantitatively analyze target nucleic acids in less than one hour at a single constant temperature, and to perform at the end of the isothermal amplification a DNA melt curve analysis for differentiating between specific and non-specific amplifications. To illustrate the potentialities of this approach for the development of a simple, robust and low-cost instrument with high throughput capability, the method was validated with an electrochemical system capable of monitoring up to 48 real-time isothermal HDA reactions simultaneously in a disposable microplate consisting of 48-electrochemical microwells. Results obtained with this approach are comparable to that obtained with a well-established but more sophisticated and expensive fluorescence-based method. This makes for a promising alternative detection method not only for real-time isothermal helicase-dependent amplification of nucleic acid, but also for other isothermal DNA amplification strategies.

  12. Simple system for isothermal DNA amplification coupled to lateral flow detection.

    Directory of Open Access Journals (Sweden)

    Kristina Roskos

    Full Text Available Infectious disease diagnosis in point-of-care settings can be greatly improved through integrated, automated nucleic acid testing devices. We have developed an early prototype for a low-cost system which executes isothermal DNA amplification coupled to nucleic acid lateral flow (NALF detection in a mesofluidic cartridge attached to a portable instrument. Fluid handling inside the cartridge is facilitated through one-way passive valves, flexible pouches, and electrolysis-driven pumps, which promotes a compact and inexpensive instrument design. The closed-system disposable prevents workspace amplicon contamination. The cartridge design is based on standard scalable manufacturing techniques such as injection molding. Nucleic acid amplification occurs in a two-layer pouch that enables efficient heat transfer. We have demonstrated as proof of principle the amplification and detection of Mycobacterium tuberculosis (M.tb genomic DNA in the cartridge, using either Loop Mediated Amplification (LAMP or the Exponential Amplification Reaction (EXPAR, both coupled to NALF detection. We envision that a refined version of this cartridge, including upstream sample preparation coupled to amplification and detection, will enable fully-automated sample-in to answer-out infectious disease diagnosis in primary care settings of low-resource countries with high disease burden.

  13. Error amplification to promote motor learning and motivation in therapy robotics.

    Science.gov (United States)

    Shirzad, Navid; Van der Loos, H F Machiel

    2012-01-01

    To study the effects of different feedback error amplification methods on a subject's upper-limb motor learning and affect during a point-to-point reaching exercise, we developed a real-time controller for a robotic manipulandum. The reaching environment was visually distorted by implementing a thirty degrees rotation between the coordinate systems of the robot's end-effector and the visual display. Feedback error amplification was provided to subjects as they trained to learn reaching within the visually rotated environment. Error amplification was provided either visually or through both haptic and visual means, each method with two different amplification gains. Subjects' performance (i.e., trajectory error) and self-reports to a questionnaire were used to study the speed and amount of adaptation promoted by each error amplification method and subjects' emotional changes. We found that providing haptic and visual feedback promotes faster adaptation to the distortion and increases subjects' satisfaction with the task, leading to a higher level of attentiveness during the exercise. This finding can be used to design a novel exercise regimen, where alternating between error amplification methods is used to both increase a subject's motor learning and maintain a minimum level of motivational engagement in the exercise. In future experiments, we will test whether such exercise methods will lead to a faster learning time and greater motivation to pursue a therapy exercise regimen.

  14. Mode group specific amplification length in an asymmetric LPG assisted few-mode EDFA

    Science.gov (United States)

    Rastogi, Vipul; Gaur, Ankita; Aschieri, Pierre; Dussardier, Bernard

    2017-01-01

    This article presents a scheme for few-mode EDFA, which allows to choose independent amplification lengths for different mode groups. The EDF is a dual concentric core fiber, where the central core is connected to the line FMF and the ring core is doped with erbium to provide amplification. The modes of FMF are launched into the central core of the EDF, are converted into ring modes using LPG for amplification and then converted back into central core modes using another LPG. The distance between the LPGs determines the amplification length. The amplification length, can thus, be chosen for a given mode group. We demonstrate the working of this concept by choosing LP11 and LP21 mode groups of the FMF and show that a suitable choice of amplification lengths for the two mode groups can tailor the differential modal gain (DMG) to any desired value. We demonstrate achieving zero DMG among all the mode of LP11 and LP21 mode groups using this concept while having gain in excess of 20 dB. The study should be useful for optical fiber communication system employing space-division multiplexing (SDM).

  15. Nonlinear Brillouin amplification of finite-duration seeds in the strong coupling regime

    International Nuclear Information System (INIS)

    Lehmann, G.; Spatschek, K. H.

    2013-01-01

    Parametric plasma processes received renewed interest in the context of generating ultra-intense and ultra-short laser pulses up to the exawatt-zetawatt regime. Both Raman as well as Brillouin amplifications of seed pulses were proposed. Here, we investigate Brillouin processes in the one-dimensional (1D) backscattering geometry with the help of numerical simulations. For optimal seed amplification, Brillouin scattering is considered in the so called strong coupling (sc) regime. Special emphasis lies on the dependence of the amplification process on the finite duration of the initial seed pulses. First, the standard plane-wave instability predictions are generalized to pulse models, and the changes of initial seed pulse forms due to parametric instabilities are investigated. Three-wave-interaction results are compared to predictions by a new (kinetic) Vlasov code. The calculations are then extended to the nonlinear region with pump depletion. Generation of different seed layers is interpreted by self-similar solutions of the three-wave interaction model. Similar to Raman amplification, shadowing of the rear layers by the leading layers of the seed occurs. The shadowing is more pronounced for initially broad seed pulses. The effect is quantified for Brillouin amplification. Kinetic Vlasov simulations agree with the three-wave interaction predictions and thereby affirm the universal validity of self-similar layer formation during Brillouin seed amplification in the strong coupling regime

  16. Multifunctional reduced graphene oxide trigged chemiluminescence resonance energy transfer: Novel signal amplification strategy for photoelectrochemical immunoassay of squamous cell carcinoma antigen.

    Science.gov (United States)

    Zhang, Yan; Sun, Guoqiang; Yang, Hongmei; Yu, Jinghua; Yan, Mei; Song, Xianrang

    2016-05-15

    Herein, a photoelectrochemical (PEC) immunoassay is constructed for squamous cell carcinoma antigen (SCCA) detection using zinc oxide nanoflower-bismuth sulfide (Bi2S3) composites as photoactive materials and reduced graphene oxide (rGO) as signal labels. Horseradish peroxidase is used to block sites against nonspecific binding, and then participated in luminol-based chemiluminescence (CL) system. The induced CL emission is acted as an inner light source to excite photoactive materials, simplifying the instrument. A novel signal amplification strategy is stem from rGO because of the rGO acts as an energy acceptor, while luminol serves as a donor to rGO, triggering the CL resonance energy transfer phenomenon between luminol and rGO. Thus, the efficient CL emission to photoactive materials decreases. Furthermore, the signal amplification caused by rGO labeled signal antibodies is related to photogenerated electron-hole pairs: perfect matching of energy levels between rGO and Bi2S3 makes rGO a sink to capture photogenerated electrons from Bi2S3; the increased steric hindrance hinders the electron donor to the surface of Bi2S3 for reaction with the photogenerated holes. On the basis of the novel signal amplification strategy, the proposed immunosensor exhibits excellent analytical performance for PEC detection of SCCA, ranging from 0.8 pg mL(-1) to 80 ng mL(-1) with a low detection limit of 0.21 pg mL(-1). Meanwhile, the designed signal amplification strategy provides a general format for future development of PEC assays. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Asexual populations of the human malaria parasite, Plasmodium falciparum, use a two-step genomic strategy to acquire accurate, beneficial DNA amplifications.

    Directory of Open Access Journals (Sweden)

    Jennifer L Guler

    Full Text Available Malaria drug resistance contributes to up to a million annual deaths. Judicious deployment of new antimalarials and vaccines could benefit from an understanding of early molecular events that promote the evolution of parasites. Continuous in vitro challenge of Plasmodium falciparum parasites with a novel dihydroorotate dehydrogenase (DHODH inhibitor reproducibly selected for resistant parasites. Genome-wide analysis of independently-derived resistant clones revealed a two-step strategy to evolutionary success. Some haploid blood-stage parasites first survive antimalarial pressure through fortuitous DNA duplications that always included the DHODH gene. Independently-selected parasites had different sized amplification units but they were always flanked by distant A/T tracks. Higher level amplification and resistance was attained using a second, more efficient and more accurate, mechanism for head-to-tail expansion of the founder unit. This second homology-based process could faithfully tune DNA copy numbers in either direction, always retaining the unique DNA amplification sequence from the original A/T-mediated duplication for that parasite line. Pseudo-polyploidy at relevant genomic loci sets the stage for gaining additional mutations at the locus of interest. Overall, we reveal a population-based genomic strategy for mutagenesis that operates in human stages of P. falciparum to efficiently yield resistance-causing genetic changes at the correct locus in a successful parasite. Importantly, these founding events arise with precision; no other new amplifications are seen in the resistant haploid blood stage parasite. This minimizes the need for meiotic genetic cleansing that can only occur in sexual stage development of the parasite in mosquitoes.

  18. What Causes SIDS?

    Science.gov (United States)

    ... Environment Look Like? How Can Caregivers Create a Safe Sleep Environment? Babies Need Tummy ... exactly what causes SIDS at this time. Scientists and health care providers are working very hard to find the cause or causes ...

  19. Construction of an internal amplification control for Mycobacterium ...

    African Journals Online (AJOL)

    Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (MTB) which mostly affects the lungs. The disease causes deaths of many people every year. There are different methods to detect MTB such as skin test, staining, culture and molecular techniques. Polymerase chain reaction (PCR) is a ...

  20. Cross species amplification ability of novel microsatellites isolated from Jatropha curcas and genetic relationship with sister taxa : Cross species amplification and genetic relationship of Jatropha using novel microsatellites

    KAUST Repository

    Pamidimarri, D. V N N Sudheer; Mastan, Shaik G.; Rahman, Hifzur; Ravi Prakash, Ch; Singh, Sweta V.; Reddy, Muppala P.

    2010-01-01

    -21 amplified in J. curcas. However, these markers did not show any cross species amplification. Overall percentage of polymorphism (PP) among the species studied was 38% and the mean genetic similarity (GS) was found to be 0.86. The highest PP (24