A single simple procedure for dewaxing, hydration and heat-induced epitope retrieval (HIER for immunohistochemistry in formalin fixed paraffin-embedded tissue

Directory of Open Access Journals (Sweden)

I.M.S. Paulsen

2015-11-01

Full Text Available Heat-induced epitope retrieval (HIER is widely used for immunohistochemistry on formalin fixed paraffin-embedded tissue and includes temperatures well above the melting point of paraffin. We therefore tested whether traditional xylene-based removal of paraffin is required on sections from paraffin-embedded tissue, when HIER is performed by vigorous boiling in 10 mM Tris/0.5 mM EGTA-buffer (pH=9. Immunohistochemical results using HIER with or without prior dewaxing in xylene were evaluated using 7 primary antibodies targeting proteins located in the cytosol, intracellular vesicles and plasma membrane. No effect of omitting prior dewaxing was observed on staining pattern. Semiquantitative analysis did not show HIER to influence the intensity of labelling consistently. Consequently, quantification of immune labelling intensity using fluorescent secondary antibodies was performed at 5 dilutions of primary antibody with and without prior dewaxing in xylene. No effect of omitting prior dewaxing on signal intensity was detectable indicating similar immunoreactivity in dewaxed and non-dewaxed sections. The intensity of staining the nucleus with the DNA-stain ToPro3 was similarly unaffected by omission of dewaxing in xylene. In conclusion, the HIER procedure described and tested can be used as a single procedure enabling dewaxing, hydration and epitope retrieval for immunohistochemistry in formalin fixed paraffin-embedded tissue.

Interaction between the dopaminergic and opioidergic systems in dorsal hippocampus in modulation of formalin-induced orofacial pain in rats.

Science.gov (United States)

Reisi, Zahra; Haghparast, Amir; Pahlevani, Pouyan; Shamsizadeh, Ali; Haghparast, Abbas

2014-09-01

The hippocampus is a region of the brain that serves several functions. The dopaminergic system acts through D1- and D2-like receptors to interfere in pain modulation and the opioid receptors play major roles in analgesic processes and there are obvious overlaps between these two systems. The present study investigated the interaction between the opioidergic and dopaminergic systems in the dorsal hippocampus (CA1) region for formalin-induced orofacial pain. Two guide cannulae were stereotaxically implanted in the CA1 region and morphine (0.5, 1, 2 and 4 μg/0.5 μl saline) and naloxone (0.3, 1 and 3 μg/0.5 μl saline) were used as the opioid receptor agonist and antagonist, respectively. SKF-38393 (1 μg/0.5 μl saline) was used as a D1-like receptor agonist, quinpirole (2 μg/0.5 μl saline) as a D2-like receptor agonist, SCH-23390 (0.5 μg/0.5 μl saline) as a D1-like receptor antagonist and sulpiride (3 μg/0.5 μl DMSO) as a D2-like receptor antagonist. To induce orofacial pain, 50 μl of 1% formalin was subcutaneously injected into the left side of the upper lip. Our results showed that different doses of morphine significantly reduced orofacial pain in both phases induced by formalin. Naloxone (1 and 3 μg) reversed morphine induced analgesia in CA1. SKF-38393 and quinpirole with naloxone (1 μg) significantly decreased formalin-induced orofacial pain in both phases. SCH-23390 had no effect on the antinociceptive response of morphine in both phases of orofacial pain. Sulpiride reversed the antinociceptive effects of morphine only in the first phase, but this result was not significant. Our findings suggest that there is cross-talk between the opioidergic and dopaminergic systems. Opioidergic neurons also exerted antinociceptive effects by modulation of the dopaminergic system in the CA1 region of the brain. Copyright © 2014 Elsevier Inc. All rights reserved.

Fluorescence-based codetection with protein markers reveals distinct cellular compartments for altered MicroRNA expression in solid tumors

DEFF Research Database (Denmark)

Sempere, Lorenzo F; Preis, Meir; Yezefski, Todd

2010-01-01

of altered miRNA expression in solid tumors, we developed a sensitive fluorescence-based in situ hybridization (ISH) method to visualize miRNA accumulation within individual cells in formalin-fixed, paraffin-embedded tissue specimens. This ISH method was implemented to be compatible with routine clinical...

Formalin treatment of radiation-induced hemorrhagic proctitis

International Nuclear Information System (INIS)

Rubinstein, E.; Ibsen, T.; Rasmussen, R.B.; Reimer, E.; Sorensen, B.L.

1986-01-01

A 71-year-old man developed severe hemorrhagic proctitis 1 year after pelvic irradiation for carcinoma of the urinary bladder. Conservative treatment as well as performance of a colostomy failed to control the rectal bleeding. After irrigation of the rectum with a formalin solution the bleeding stopped, and no recurrence has been observed for the next 14 months

Altered formalin-induced pain and Fos induction in the periaqueductal grey of preadolescent rats following neonatal LPS exposure.

Directory of Open Access Journals (Sweden)

Ihssane Zouikr

Full Text Available Animal and human studies have demonstrated that early pain experiences can produce alterations in the nociceptive systems later in life including increased sensitivity to mechanical, thermal, and chemical stimuli. However, less is known about the impact of neonatal immune challenge on future responses to noxious stimuli and the reactivity of neural substrates involved in analgesia. Here we demonstrate that rats exposed to Lipopolysaccharide (LPS; 0.05 mg/kg IP, Salmonella enteritidis during postnatal day (PND 3 and 5 displayed enhanced formalin-induced flinching but not licking following formalin injection at PND 22. This LPS-induced hyperalgesia was accompanied by distinct recruitment of supra-spinal regions involved in analgesia as indicated by significantly attenuated Fos-protein induction in the rostral dorsal periaqueductal grey (DPAG as well as rostral and caudal axes of the ventrolateral PAG (VLPAG. Formalin injections were associated with increased Fos-protein labelling in lateral habenula (LHb as compared to medial habenula (MHb, however the intensity of this labelling did not differ as a result of neonatal immune challenge. These data highlight the importance of neonatal immune priming in programming inflammatory pain sensitivity later in development and highlight the PAG as a possible mediator of this process.

Altered Formalin-Induced Pain and Fos Induction in the Periaqueductal Grey of Preadolescent Rats following Neonatal LPS Exposure

Science.gov (United States)

Zouikr, Ihssane; James, Morgan H.; Campbell, Erin J.; Clifton, Vicki L.; Beagley, Kenneth W.; Dayas, Christopher V.; Hodgson, Deborah M.

2014-01-01

Animal and human studies have demonstrated that early pain experiences can produce alterations in the nociceptive systems later in life including increased sensitivity to mechanical, thermal, and chemical stimuli. However, less is known about the impact of neonatal immune challenge on future responses to noxious stimuli and the reactivity of neural substrates involved in analgesia. Here we demonstrate that rats exposed to Lipopolysaccharide (LPS; 0.05 mg/kg IP, Salmonella enteritidis) during postnatal day (PND) 3 and 5 displayed enhanced formalin-induced flinching but not licking following formalin injection at PND 22. This LPS-induced hyperalgesia was accompanied by distinct recruitment of supra-spinal regions involved in analgesia as indicated by significantly attenuated Fos-protein induction in the rostral dorsal periaqueductal grey (DPAG) as well as rostral and caudal axes of the ventrolateral PAG (VLPAG). Formalin injections were associated with increased Fos-protein labelling in lateral habenula (LHb) as compared to medial habenula (MHb), however the intensity of this labelling did not differ as a result of neonatal immune challenge. These data highlight the importance of neonatal immune priming in programming inflammatory pain sensitivity later in development and highlight the PAG as a possible mediator of this process. PMID:24878577

A single simple procedure for dewaxing, hydration and heat-induced epitope retrieval (HIER) for immunohistochemistry in formalin fixed paraffin-embedded tissue

DEFF Research Database (Denmark)

Paulsen, I M S; Dimke, H; Frische, S

2015-01-01

Heat-induced epitope retrieval (HIER) is widely used for immunohistochemistry on formalin fixed paraffin-embedded tissue and includes temperatures well above the melting point of paraffin. We therefore tested whether traditional xylene-based removal of paraffin is required on sections from paraff...... of dewaxing in xylene. In conclusion, the HIER procedure described and tested can be used as a single procedure enabling dewaxing, hydration and epitope retrieval for immunohistochemistry in formalin fixed paraffin-embedded tissue....

Synergistic analgesia of duloxetine and celecoxib in the mouse formalin test: a combination analysis.

Directory of Open Access Journals (Sweden)

Yong-Hai Sun

Full Text Available Duloxetine, a serotonin and noradrenaline reuptake inhibitor, and celecoxib, a non-steroidal anti-inflammatory drug, are commonly used analgesics for persistent pain, however with moderate gastrointestinal side effects or analgesia tolerance. One promising analgesic strategy is to give a combined prescription, allowing the maximal or equal efficacy with fewer side effects. In the current study, the efficacy and side effects of combined administration of duloxetine and celecoxib were tested in the mouse formalin pain model. The subcutaneous (s.c. injection of formalin into the left hindpaw induced significant somatic and emotional pain evaluated by the biphasic spontaneous flinching of the injected hindpaw and interphase ultrasonic vocalizations (USVs during the 1 h after formalin injection, respectively. Pretreatment with intraperitoneal (i.p. injection of duloxetine or celecoxib at 1 h before formalin injection induced the dose-dependent inhibition on the second but not first phase pain responses. Combined administration of duloxetine and celecoxib showed significant analgesia for the second phase pain responses. Combination analgesia on the first phase was observed only with higher dose combination. A statistical difference between the theoretical and experimental ED50 for the second phase pain responses was observed, which indicated synergistic interaction of the two drugs. Concerning the emotional pain responses revealed with USVs, we assumed that the antinociceptive effects were almost completely derived from duloxetine, since celecoxib was ineffective when administered alone or reduced the dosage of duloxetine when given in combination. Based on the above findings, acute concomitant administration of duloxetine and celecoxib showed synergism on the somatic pain behavior but not emotional pain behaviors.

D1- and D2-like dopamine receptors within the nucleus accumbens contribute to stress-induced analgesia in formalin-related pain behaviours in rats.

Science.gov (United States)

Faramarzi, G; Zendehdel, M; Haghparast, A

2016-10-01

Stressful experiences can produce analgesia, termed stress-induced analgesia (SIA). Meanwhile, it has been widely established that the mesolimbic dopamine pathway and nucleus accumbens (NAc) have a profound role in pain modulation. In this study, we examined the role of accumbal dopamine receptors in antinociception caused by forced swim stress (FSS) in order to understand more about the function of these receptors within the NAc in FSS-induced analgesia. Stereotaxic surgery was unilaterally performed on adult male Wistar rats weighing 230-250 g (some on the left and some on the right side of the midline). Two supergroups were microinjected into the NAc with a D1-like dopamine receptor antagonist, SCH-23390, at doses of 0.25, 1 and 4 μg/0.5 μl saline per rat or Sulpiride as a D2-like dopamine receptor antagonist at the same doses [0.25, 1 and 4 μg/0.5 μl dimethyl sulfoxide (DMSO) per rat]; while their controls just received intra-accumbal saline or DMSO at 0.5 μl, respectively. The formalin test was performed after rats were subjected to FSS (6 min, 25 ± 1 °C) to assess pain-related behaviours. The results demonstrated that intra-accumbal infusions of SCH-23390 and Sulpiride dose-dependently reduced FSS-induced antinociception in both phases of the formalin test. However, the percentage decrease in area under the curve (AUC) values calculated for treatment groups compared to formalin-control group was more significant in the late phase than the early phase. Our findings suggest that D1- and D2-like dopamine receptors in the NAc are involved in stress-induced antinociceptive behaviours in the formalin test as an animal model of persistent inflammatory pain. Forced swim stress (FSS) induces the antinociception in both phases of formalin test. Blockade of accumbal dopamine receptors attenuate the antinociception induced by FSS. Stress-induced analgesia is dose-dependently reduced by dopamine receptor antagonists in both phases, although it is more

Effects of opioids in the formalin test in the Speke's hinged tortoise (Kinixy's spekii)

DEFF Research Database (Denmark)

Wambugu, SN; Towett, PK; Kiama, SG

2010-01-01

decrease in the duration of limb retraction in the formalin test. The anti-nociceptive effects were naloxone (5 mg/kg) reversible. The data suggest that the formalin test is a good test for studying nociception and anti-nociception in tortoises and that the opioidergic system plays a role in the control......Little is known about analgesia in lower vertebrates such as the Speke's hinged tortoise (Kinixy's spekii), yet of late they are increasingly being adopted as pets. The effects of morphine (5, 7.5, 10 and 20 mg/kg), pethidine (10, 20, and 50 mg/kg) and naloxone (5 mg/kg) on nociception induced...... by the formalin test (12.5%, 100 microL) were studied in the Speke's hinged tortoise. Formalin induced a monophasic limb retraction behavioural response and its duration was recorded. The behaviour lasted for 16.4 +/- 0.8 min. Morphine (7.5, 10 and 20 mg/kg) and pethidine (20 and 50 mg/kg) induced significant...

Label-free protein profiling of formalin-fixed paraffin-embedded (FFPE) heart tissue reveals immediate mitochondrial impairment after ionising radiation.

Science.gov (United States)

Azimzadeh, Omid; Scherthan, Harry; Yentrapalli, Ramesh; Barjaktarovic, Zarko; Ueffing, Marius; Conrad, Marcus; Neff, Frauke; Calzada-Wack, Julia; Aubele, Michaela; Buske, Christian; Atkinson, Michael J; Hauck, Stefanie M; Tapio, Soile

2012-04-18

Qualitative proteome profiling of formalin-fixed, paraffin-embedded (FFPE) tissue is advancing the field of clinical proteomics. However, quantitative proteome analysis of FFPE tissue is hampered by the lack of an efficient labelling method. The usage of conventional protein labelling on FFPE tissue has turned out to be inefficient. Classical labelling targets lysine residues that are blocked by the formalin treatment. The aim of this study was to establish a quantitative proteomics analysis of FFPE tissue by combining the label-free approach with optimised protein extraction and separation conditions. As a model system we used FFPE heart tissue of control and exposed C57BL/6 mice after total body irradiation using a gamma ray dose of 3 gray. We identified 32 deregulated proteins (p≤0.05) in irradiated hearts 24h after the exposure. The proteomics data were further evaluated and validated by bioinformatics and immunoblotting investigation. In good agreement with our previous results using fresh-frozen tissue, the analysis indicated radiation-induced alterations in three main biological pathways: respiratory chain, lipid metabolism and pyruvate metabolism. The label-free approach enables the quantitative measurement of radiation-induced alterations in FFPE tissue and facilitates retrospective biomarker identification using clinical archives. Copyright © 2012 Elsevier B.V. All rights reserved.

Commercial formalin substitutes for histopathology

DEFF Research Database (Denmark)

Prentø, P; Lyon, H

1997-01-01

We compared the performance of six commercial fixatives proposed to be formalin substitutes with the performance of buffered formalin, Clarke's ethanol-acetic acid, and ethanol, using rat liver, small intestine, and kidney. We investigated the rate of penetration, mode of fixation, extent of prot...... was obtained by combining formalin fixation with antigen retrieval. We conclude that none of the proposed commercial substitutes for buffered formalin are adequate for critical histology or histopathology....

Inhibition of Spinal Interlukin-33/ST2 Signaling and Downstream ERK and JNK Pathways in Electroacupuncture Analgesia in Formalin Mice.

Directory of Open Access Journals (Sweden)

Ping Han

Full Text Available Although acupuncture is widely used to manage pain, it remains highly controversial, largely due to the lack of a clear mechanism for its benefits. Here, we investigated the role of IL-33, a novel interleukin (IL-1 family member, and its receptor ST2 in the analgesic effects of electroacupuncture (EA on formalin-induced inflammatory pain. The results showed that 1 EA stimulation of ipsilateral Zusanli (ST 36 and Yanglingquan (GB 34 acupoints for 30 min remarkably suppressed the two phases of formalin-induced spontaneous pain; 2 subcutaneous or intrathecal administration of recombinant IL-33 (rIL-33 significantly inhibited the analgesic effect of EA, whereas the ST2 antibody potentiated EA analgesia in formalin mice; 3 EA treatment decreased the up-regulation of IL-33 and ST2 protein following formalin injection; and 4 the suppression of the formalin-induced expression of spinal phosphorylated ERK and JNK induced by EA treatment was significantly attenuated following subcutaneous rIL-33 delivery, and was further decreased by the ST2 antibody. These data suggest that EA alleviates formalin-induced inflammatory pain, at least partially, by inhibiting of spinal IL-33/ST2 signaling and the downstream ERK and JNK pathways.

Inhibition of Spinal Interlukin-33/ST2 Signaling and Downstream ERK and JNK Pathways in Electroacupuncture Analgesia in Formalin Mice

Science.gov (United States)

Zhao, Jing; Wang, Yanqing; Wu, Gencheng; Mi, Wenli

2015-01-01

Although acupuncture is widely used to manage pain, it remains highly controversial, largely due to the lack of a clear mechanism for its benefits. Here, we investigated the role of IL-33, a novel interleukin (IL)-1 family member, and its receptor ST2 in the analgesic effects of electroacupuncture (EA) on formalin-induced inflammatory pain. The results showed that 1) EA stimulation of ipsilateral Zusanli (ST 36) and Yanglingquan (GB 34) acupoints for 30 min remarkably suppressed the two phases of formalin-induced spontaneous pain; 2) subcutaneous or intrathecal administration of recombinant IL-33 (rIL-33) significantly inhibited the analgesic effect of EA, whereas the ST2 antibody potentiated EA analgesia in formalin mice; 3) EA treatment decreased the up-regulation of IL-33 and ST2 protein following formalin injection; and 4) the suppression of the formalin-induced expression of spinal phosphorylated ERK and JNK induced by EA treatment was significantly attenuated following subcutaneous rIL-33 delivery, and was further decreased by the ST2 antibody. These data suggest that EA alleviates formalin-induced inflammatory pain, at least partially, by inhibiting of spinal IL-33/ST2 signaling and the downstream ERK and JNK pathways. PMID:26067287

Blockade of Adrenal Medulla-Derived Epinephrine Potentiates Bee Venom-Induced Antinociception in the Mouse Formalin Test: Involvement of Peripheral β-Adrenoceptors

Directory of Open Access Journals (Sweden)

Suk-Yun Kang

2013-01-01

Full Text Available The injection of diluted bee venom (DBV into an acupoint has been used traditionally in eastern medicine to treat a variety of inflammatory chronic pain conditions. We have previously shown that DBV had a potent antinociceptive efficacy in several rodent pain models. However, the peripheral mechanisms underlying DBV-induced antinociception remain unclear. The present study was designed to investigate the role of peripheral epinephrine on the DBV-induced antinociceptive effect in the mouse formalin assay. Adrenalectomy significantly enhanced the antinociceptive effect of DBV during the late phase of the formalin test, while chemical sympathectomy had no effect. Intraperitoneal injection of epinephrine blocked this adrenalectomy-induced enhancement of the DBV-induced antinociceptive effect. Moreover, injection of a phenylethanolamine N-methyltransferase (PNMT inhibitor enhanced the DBV-induced antinociceptive effect. Administration of nonselective β-adrenergic antagonists also significantly potentiated this DBV-induced antinociception, in a manner similar to adrenalectomy. These results demonstrate that the antinociceptive effect of DBV treatment can be significantly enhanced by modulation of adrenal medulla-derived epinephrine and this effect is mediated by peripheral β-adrenoceptors. Thus, DBV acupoint stimulation in combination with inhibition of peripheral β-adrenoceptors could be a potentially novel strategy for the management of inflammatory pain.

Involvement of dopamine receptors within the dorsal hippocampus in suppression of the formalin-induced orofacial pain.

Science.gov (United States)

Shamsizadeh, Ali; Pahlevani, Pouyan; Haghparast, Amir; Moslehi, Maryam; Zarepour, Leila; Haghparast, Abbas

2013-12-01

It is widely established that the dopaminergic system has profound effects on pain modulation in different regions of the brain including the hippocampus, the salient area for brain functions. The orofacial region is one of the most densely innervated (by the trigeminal nerves) areas of the body susceptible to acute and chronic pains. In this study, we tried to examine the effects of dopamine receptors located in the dorsal hippocampus (CA1) region upon the modulation of orofacial pain induced by the formalin test. To induce orofacial pain in male Wistar rats, 50μl of 1% formalin was subcutaneously injected into the upper lip. In control and experimental groups, two guide cannulae were stereotaxically implanted in the CA1, and SKF-38393 (0.25, 0.5, 1 and 2μg/0.5μl saline) as a D1-like receptor agonist, SCH-23390 (1μg/0.5μl saline) as a D1-like receptor antagonist, Quinpirole (0.5, 1, 2 and 4μg/0.5μl saline) as a D2-like receptor agonist and Sulpiride(3μg/0.5μl DMSO) as a D2-like receptor antagonist or vehicles were microinjected. For induction of orofacial pain, 50μl of 1% formalin was subcutaneously injected into the left side of the upper lip. Results indicated that SKF-38393 at the dose of 1 and 2μg significantly reduced pain during the first and second phases of observed pain while SCH-23390 reversed such analgesic effect. Moreover, there is a significant difference between groups in which animals received 2 and 4μg quinpirole or vehicle in the first phase (early phase) of pain. The three high doses of this compound (1, 2 and 4μg) appeared to have an analgesic effect during the second (late) phase. Furthermore, Sulpiride could potentially reverse the observed analgesic effects already induced by an agonist. Current findings suggest that the dorsal hippocampal dopamine receptors exert an analgesic effect during the orofacial pain test. Copyright © 2013 Elsevier Inc. All rights reserved.

The role of nicotinic acetylcholine and opioid systems of the ventral orbital cortex in modulation of formalin-induced orofacial pain in rats.

Science.gov (United States)

Yousofizadeh, Shahnaz; Tamaddonfard, Esmaeal; Farshid, Amir Abbas

2015-07-05

Nicotinic acetylcholine and opioid receptors are involved in modulation of pain. In the present study, we investigated the effects of microinjection of nicotinic acetylcholine and opioid compounds into the ventral orbital cortex (VOC) on the formalin-induced orofacial pain in rats. For this purpose, two guide cannulas were placed into the left and right sides of the VOC of the brain. Orofacial pain was induced by subcutaneous injection of a diluted formalin solution (50μl, 1.5%) into the right vibrissa pad and face rubbing durations were recorded at 3-min blocks for 45min. Formalin produced a marked biphasic pain response (first phase: 0-3min and second phase: 15-33min). Epibatidine (a nicotinic receptor agonist) at doses of 0.05, 0.1 and 0.2μg/site, morphine (an opioid receptor agonist) at doses of 0.5, 1 and 2μg/site and their sub-analgesic doses (0.025μg/site epibatidine with 0.25μg/site morphine) combination treatment suppressed the second phase of pain. The antinociceptive effect induced by 0.2μg/site of epibatidine, but not morphine (2μg/site), was prevented by 2μg/site of mecamylamine (a nicotinic receptor antagonist). Naloxone (an opioid receptor antagonist) at a dose of 2μg/site prevented the antinociceptive effects induced by 2μg/site of morphine and 0.2μg/site of epibatidine. No above-mentioned chemical compounds affected locomotor activity. These results showed that at the VOC level, epibatidine and morphine produced antinociception. In addition, opioid receptor might be involved in epibatidine-induced antinociception, but the antinociception induced by morphine was not mediated through nicotinic acetylcholine receptor. Copyright © 2015 Elsevier B.V. All rights reserved.

Anterior cingulate cortex is crucial for contra- but not ipsi-lateral electro-acupuncture in the formalin-induced inflammatory pain model of rats

Directory of Open Access Journals (Sweden)

Xing Guo-Gang

2011-08-01

Full Text Available Abstract Acupuncture and electro-acupuncture (EA are now widely used to treat disorders like pain. We and others have shown previously that current frequency, intensity and treatment duration all significantly influence the anti-nociceptive effects of EA. There is evidence that stimulating sites also affect the antinociception, with EA applied ipsilaterally to the pain site being more effective under some pain states but contralateral EA under others. It was recently reported that local adenosine A1 receptors were responsible for ipsilateral acupuncture, but what mechanisms specifically mediate the anti-nociceptive effects of contralateral acupuncture or EA remains unclear. In the present study, we applied 100 Hz EA on the ipsi- or contra-lateral side of rats with inflammatory pain induced by intra-plantar injection of formalin, and reported distinct anti-nociceptive effects and mechanisms between them. Both ipsi- and contra-lateral EA reduced the paw lifting time in the second phase of the formalin test and attenuated formalin-induced conditioned place aversion. Contralateral EA had an additional effect of reducing paw licking time, suggesting a supraspinal mechanism. Lesions of rostral anterior cingulate cortex (ACC completely abolished the anti-nociceptive effects of contra- but not ipsi-lateral EA. These findings were not lateralized effects, since injection of formalin into the left or right hind paws produced similar results. Overall, these results demonstrated distinct anti-nociceptive effects and mechanisms between different stimulating sides and implied the necessity of finding the best stimulating protocols for different pain states.

Effects of crocin and safranal, saffron constituents, on the formalin-induced orofacial pain in rats

Directory of Open Access Journals (Sweden)

Amir Erfanparast

2015-08-01

Full Text Available Objective: Crocin and safranal are the main components of saffron, and have many biological functions such as anti-inflammatory and antioxidant activities. In the present study, we investigated the effects of crocin, safranal, morphine, diclofenac and naloxone in combined and separately on formalin-induced orofacial pain in rats. Materials and Methods: Subcutaneous injection of a diluted formalin solution (50 µl, 1.5% into the upper lip region produced a biphasic pattern of pain response (a neurogenic phase: 0-3 min and an inflammatory phase: 15-33 min. The time each animal spent face rubbing with ipsilateral forepaw was recorded and considered as an index of nociception Results: Intraperitoneal injections of crocin (12.5 and 25 mg/kg, safranal (0.25 and 0.5 mg/kg, diclofenac (5 and 10 mg/kg and morphine (1 and 2 mg/kg suppressed the second phase of pain. The second phase of pain was also reduced when low (ineffective doses of crocin (6.25 mg/kg and safranal (0.125 mg/kg were co-administered with low doses of diclofenac (2.5 mg/kg and morphine (0.5 mg/kg. The more antinociceptive effects were observed when the medium doses of the above-mentioned chemicals used together. Naloxone prevented morphine-induced antinociception, but did not inhibit the suppressive effects of crocin and safranal. Safranal at a high dose (0.5 mg/kg suppressed locomotor activity. Conclusion: The present results showed antinociceptive effects for crocin and safranal in inflammatory pain. Opioid receptors may not be involved in the antinociceptive effect of crocin and safranal. Crocin and safranal increased diclofenac-induced antinociception.

A case study of rabies diagnosis from formalin-fixed brain material : short communication

Directory of Open Access Journals (Sweden)

J. Coertse

2011-05-01

Full Text Available Rabies is caused by several Lyssavirus species, a group of negative sense RNA viruses. Although rabies is preventable, it is often neglected particularly in developing countries in the face of many competing public and veterinary health priorities. Epidemiological information based on laboratory-based surveillance data is critical to adequately strategise control and prevention plans. In this regard the fluorescent antibody test for rabies virus antigen in brain tissues is still considered the basic requirement for laboratory confirmation of animal cases. Occasionally brain tissues from suspected rabid animals are still submitted in formalin, although this has been discouraged for a number of years. Immunohistochemical testing or a modified fluorescent antibody technique can be performed on such samples. However, this method is cumbersome and cannot distinguish between different Lyssavirus species. Owing to RNA degradation in formalin-fixed tissues, conventional RT-PCR methodologies have also been proven to be unreliable. This report is concerned with a rabies case in a domestic dog from an area in South Africa where rabies is not common. Typing of the virus involved was therefore important, but the only available sample was submitted as a formalin-fixed specimen. A real-time RT-PCR method was therefore applied and it was possible to confirmrabies and obtain phylogenetic information that indicated a close relationship between this virus and the canid rabies virus variants from another province (KwaZulu-Natal in South Africa.

Histology without formalin?

Science.gov (United States)

Buesa, René J

2008-12-01

Because formalin is toxic, carcinogenic, and a poor preserver of nucleic acids, for more than 20 years, there have been numerous attempts to find a substitute, with as many different alternative fixatives, none totally successful. With a fast penetration, formaldehyde is a slow and reversible fixative that requires 24 to 48 hours to completely bind to tissue; thus, any surgical specimen arriving to the laboratory between 8 AM and 4 PM and processed conventionally for the slides to be ready the following day will be only between 30% and 66% bound and even less fixed when the dehydration starts, resulting in an additional and also incomplete alcoholic fixation. This causes infiltration problems and can affect subsequent tests, especially immunohistochemistry. Formaldehyde fixation is tissue thickness independent between 16 microm and 4 mm but is faster at above room temperature, so the fixation of specimens with less than 24 hours in formalin can be improved if the fixing stations in the conventional tissue processors are set at 40 degrees C. If the safety measures are improved to offer a work environment with a time weighted average level of 0.4 ppm, and the contact with formalin is reduced to a minimum by discouraging its neutralization and limiting the recycling practice to filtering methods, formalin could remain as the routine fixative, with modified methacarn for those specimens requiring nucleic acids studies. This is a preferred solution than having to validate all the standard and special procedures, including those US Food and Drug Administration approved, if formalin is replaced by another fixative without its advantages. To the question posed in the title of this article, the answer is "Yes, it can be done, but that is neither likely nor worth it!"

Simulating fluorescence light-canopy interaction in support of laser-induced fluorescence measurements

International Nuclear Information System (INIS)

Rosema, A.; Verhoef, W.; Schroote, J.; Snel, J.F.H.

1991-01-01

In the Netherlands an operational field instrument for the measurement of laser induced fluorescence of vegetation (LEAF) is developed. In addition, plant physiological and remote sensing research is done to support this new remote sensing instrument. This paper presents a general introduction on the subject of laser-induced fluorescence, including the relation between chlorophyll fluorescence and photosynthesis, spectral characteristics, and previous research. Also the LEAF system is briefly described. Subsequently, the development of a leaf fluorescence model (KMF) and a canopy fluorescence model (FLSAIL) are reported. With these simulation models a sensitivity study is carried out. Fluorescence of 685 nm appears to be most suitable to obtain information on photosynthesis and stress, but is also influenced by canopy structure. Separation of these two effects is studied

Interaction between dexibuprofen and dexketoprofen in the orofacial formalin test in mice.

Science.gov (United States)

Miranda, H F; Noriega, V; Sierralta, F; Prieto, J C

2011-01-01

Animal models are used to research the mechanisms of pain and to mimic human pain. The purpose of this study was to determine the degree of interaction between dexketoprofen and dexibuprofen, by isobolographic analysis using the formalin orofacial assay in mice. This assay presents two-phase time course: an early short-lasting, phase I, starting immediately after the formalin injection producing a tonic acute pain, leaving a 15 min quiescent period, followed by a prolonged, phase II, after the formalin and representing inflammatory pain. Administration of dexketoprofen or dexibuprofen produced a dose-dependent antinociception, with different potency, either during phases I or II. The co-administration of dexketoprofen and dexibuprofen produced synergism in phase I and II. In conclusion, both dexketoprofen and dexibuprofen are able to induce antinociception in the orofacial formalin assay. Their co-administration produced a synergism, which could be related to the different degree of COX inhibition and other mechanisms of analgesics. Copyright © 2010 Elsevier Inc. All rights reserved.

Disruption of the hydrogen bonding network determines the pH-induced non-fluorescent state of the fluorescent protein ZsYellow by protonation of Glu221.

Science.gov (United States)

Bae, Ji-Eun; Kim, In Jung; Nam, Ki Hyun

2017-11-04

Many fluorescent proteins (FPs) exhibit fluorescence quenching at a low pH. This pH-induced non-fluorescent state of an FP serves as a useful indicator of the cellular pH. ZsYellow is widely used as an optical marker in molecular biology, but its pH-induced non-fluorescent state has not been characterized. Here, we report the pH-dependent spectral properties of ZsYellow, which exhibited the pH-induced non-fluorescence state at a pH below 4.0. We determined the crystal structures of ZsYellow at pH 3.5 (non-fluorescence state) and 8.0 (fluorescence state), which revealed the cis-configuration of the chromophore without pH-induced isomerization. In the non-fluorescence state, Arg95, which is involved in stabilization of the exited state of the chromophore, was found to more loosely interact with the carbonyl oxygen atom of the chromophore when compared to the interaction at pH 8.0. In the fluorescence state, Glu221, which is involved in the hydrogen bonding network around the chromophore, stably interacted with Gln42 and His202. By contrast, in the non-fluorescence state, the protonated conserved Glu221 residue exhibited a large conformational change and was separated from His202 by 5.46 Å, resulting in breakdown of the hydrogen bond network. Our results provide insight into the critical role of the conserved Glu221 residue for generating the pH-induced non-fluorescent state. Copyright © 2017 Elsevier Inc. All rights reserved.

21 CFR 529.1030 - Formalin.

Science.gov (United States)

2010-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1030 Formalin. (a... never exceed 1 hour even if fish show no signs of stress. Do not apply formalin to ponds with water...

FORMALIN IS DELETERIOUS TO CYTOSKELETON PROTEINS - DO WE NEED TO REPLACE IT BY FORMALIN-FREE KRYOFIX

NARCIS (Netherlands)

BOON, ME; KOK, LP

1991-01-01

Formalin is hazardous for the environment and for the laboratory personnel and deleterious to cytoskeleton proteins. The pathology and anatomy laboratory can be formalin-free when Kryofix is used as a substitute fixative. In four years experience with Kryofix, we learned that immunostaining on

High-throughput sequencing and copy number variation detection using formalin fixed embedded tissue in metastatic gastric cancer.

Directory of Open Access Journals (Sweden)

Seokhwi Kim

Full Text Available In the era of targeted therapy, mutation profiling of cancer is a crucial aspect of making therapeutic decisions. To characterize cancer at a molecular level, the use of formalin-fixed paraffin-embedded tissue is important. We tested the Ion AmpliSeq Cancer Hotspot Panel v2 and nCounter Copy Number Variation Assay in 89 formalin-fixed paraffin-embedded gastric cancer samples to determine whether they are applicable in archival clinical samples for personalized targeted therapies. We validated the results with Sanger sequencing, real-time quantitative PCR, fluorescence in situ hybridization and immunohistochemistry. Frequently detected somatic mutations included TP53 (28.17%, APC (10.1%, PIK3CA (5.6%, KRAS (4.5%, SMO (3.4%, STK11 (3.4%, CDKN2A (3.4% and SMAD4 (3.4%. Amplifications of HER2, CCNE1, MYC, KRAS and EGFR genes were observed in 8 (8.9%, 4 (4.5%, 2 (2.2%, 1 (1.1% and 1 (1.1% cases, respectively. In the cases with amplification, fluorescence in situ hybridization for HER2 verified gene amplification and immunohistochemistry for HER2, EGFR and CCNE1 verified the overexpression of proteins in tumor cells. In conclusion, we successfully performed semiconductor-based sequencing and nCounter copy number variation analyses in formalin-fixed paraffin-embedded gastric cancer samples. High-throughput screening in archival clinical samples enables faster, more accurate and cost-effective detection of hotspot mutations or amplification in genes.

Effect of Low Dose Lead (Pb) Administration on Tail Immersion Test and Formalin-induced Pain in Wistar Rats: Possible Modulatory Role of Cobalt (II) Chloride.

Science.gov (United States)

Umar, A H; Suleiman, I; Muhammed, H

2017-03-06

Lead (Pb) is cheap and there is a long tradition of its use, but its toxic effects have also been recognized. There is increased public health concern regarding the hazards of low dose Pb exposure to adults and children. Studies have shown the risks for hypertension, decrements in renal function, subtle decline in cognitive function, and adverse reproductive outcome at low blood Pb level. In this study, the possible modulatory role of cobalt (II) chloride (CoCl2) on low level Pb exposure on tail immersion test and formalin induced pain was investigated. Twenty adult Wistar rats of both sexes (weight 150g to 200g) were used. The animals were divided into four groups (n = 5) and administered Pb (5mg/kg), Pb (5mg/kg) + CoCl2 (50mg/kg) and CoCl2 (50mg/kg) orally for twenty-eight days. The last group served as control and were given distilled water only. In the tail immersion test, there was no significant change in reaction time for all three groups when compared to the control. In the formalin-induced pain, pain score after five and forty-five minutes also do not show significant change for all the three groups when compared to control. This work suggested that exposure to 5mg/kg Pb for twenty-eight days do not significantly impair reaction time in tail immersion test and pain score in formalin induced pain in Wistar rats. Also, administration of 50mg/kg CoCl2 do not improve performance of the animals in the experiments.

Remote sensing vegetation status by laser-induced fluorescence

International Nuclear Information System (INIS)

Günther, K.P.; Dahn, H.G.; Lüdeker, W.

1994-01-01

In November 1989 the EUREKA project LASFLEUR (EU 380) started as an European research effort to investigate the future application of far-field laser-induced plant fluorescence for synoptic, airborne environmental monitoring of vegetation. This report includes a brief introduction in a theoretically approach for the laser-induced fluorescence signals of leaves and their spectral and radiometric behaviour. In addition, a detailed description of the design and realization of the second generation of the far-field fluorescence lidar (DLidaR-2) is given with special regard to the optical and electronical setup, followed by a short explanation of the data processing. The main objectives of the far field measurements are to demonstrate the link between laser-induced fluorescence data and plant physiology and to show the reliability of remote single shot lidar measurements. The data sets include the typical daily cycles of the fluorescence for different global irradiation. As expected from biophysical models, the remotely sensed chlorophyll fluorescence is highly correlated with the carbon fixation rate, while the fluorescence ratio F685 / F730 is only dependent on the chlorophyll concentration. Drought stress measurement of evergreen oaks Quercus pubescens confirm the findings of healthy plants with regard to the fluorescence ratio F685 / F730 while the fluorescence signals of stressed plants show a different behavior than nonstressed plants. Additionally, the corresponding physiological data (porometer and PAM data) are presented. (author)

Properties of a non-bioactive fluorescent derivative of differentiation-inducing factor-3, an anti-tumor agent found in Dictyostelium discoideum

Directory of Open Access Journals (Sweden)

Yuzuru Kubohara

2014-03-01

Full Text Available Differentiation-inducing factor-3 (DIF-3, found in the cellular slime mold Dictyostelium discoideum, and its derivatives, such as butoxy-DIF-3 (Bu-DIF-3, are potent anti-tumor agents. To investigate the activity of DIF-like molecules in tumor cells, we recently synthesized a green fluorescent DIF-3 derivative, BODIPY-DIF-3G, and analyzed its bioactivity and cellular localization. In this study, we synthesized a red (orange fluorescent DIF-3 derivative, BODIPY-DIF-3R, and compared the cellular localization and bioactivities of the two BODIPY-DIF-3s in HeLa human cervical cancer cells. Both fluorescent compounds penetrated the extracellular membrane within 0.5 h and localized mainly to the mitochondria. In formalin-fixed cells, the two BODIPY-DIF-3s also localized to the mitochondria, indicating that the BODIPY-DIF-3s were incorporated into mitochondria independently of the mitochondrial membrane potential. After treatment for 3 days, BODIPY-DIF-3G, but not BODIPY-DIF-3R, induced mitochondrial swelling and suppressed cell proliferation. Interestingly, the swollen mitochondria were stainable with BODIPY-DIF-3G but not with BODIPY-DIF-3R. When added to isolated mitochondria in vitro, BODIPY-DIF-3G increased dose-dependently the rate of O2 consumption, but BODIPY-DIF-3R did not. These results suggest that the bioactive BODIPY-DIF-3G suppresses cell proliferation, at least in part, by altering mitochondrial activity, whereas the non-bioactive BODIPY-DIF-3R localizes to the mitochondria but does not affect mitochondrial activity or cell proliferation.

Functionalization of embedded thiol-ene waveguides for evanescent wave induced fluorescence detection in a microfluidic device

DEFF Research Database (Denmark)

Feidenhans'l, Nikolaj Agentoft; Jensen, Thomas Glasdam; Lafleur, Josiane P.

2013-01-01

We demonstrate the use of functional surface groups inherently present on off-stoichiometric thiol−ene polymers, for site-specific immobilization of biomolecules and detection by evanescent wave-induced fluorescence. An optofluidic chip featuring an embedded thiol−ene waveguide was selectively...... functionalized with biotin using photografting. The biotin was used for immobilization of fluorescently labelled streptavidin, and experiments revealed a linear correlation between streptavidin concentration and fluorescent intensity. To further demonstrate the attractiveness of using thiol−ene for optofluidic...

Solvent induced fluorescence enhancement of graphene oxide studied by ultrafast spectroscopy

Science.gov (United States)

Zhao, Litao; Chen, Jinquan; He, Xiaoxiao; Yu, Xiantong; Yan, Shujun; Zhang, Sanjun; Pan, Haifeng; Xu, Jianhua

2018-05-01

Femtosecond transient absorption (TA) spectroscopy combined with picosecond time resolved fluorescence (TRF) were used to reveal the fluorescence kinetics of graphene oxide (GO) in water, ethanol and water-ethanol mixtures. Size-independent fluorescence of GO were observed in water, and pH-dependent fluorescence spectra could be fitted well by a triple emission relaxation with peaks around 440 nm, 500 nm, and 590 nm respectively. The results indicate that polycyclic aromatic hydrocarbons (PAHs) linked by oxygen-containing functional groups dominate GO's fluorescence emission. GO's fluorescence quantum yield was measured to be 2.8% in ethanol but 1.2% in water. The three decay components fluorescence decay, as well as the transient absorption dynamics with an offset, confirmed this solvent induced fluorescence enhancement. GO's Raman spectral signals showed that GO in ethanol has a smaller average size of PAHs than that of GO in water. Therefore, besides other enhancement effects reported in literatures, we proposed that solvents could also change the size of PAHs, resulting in a photoluminescence enhancement. Our experimental data demonstrates that GO's quantum yield could be up to 2.8% in water and 8.4% in ethanol and this observation may help ones to improve GO's photoluminescence efficiency as well as its applications in solution.

Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

Science.gov (United States)

Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

2007-10-10

A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy.

Science.gov (United States)

Hovhannisyan, V; Guo, H W; Hovhannisyan, A; Ghukasyan, V; Buryakina, T; Chen, Y F; Dong, C Y

2014-05-01

Collagen is the main structural protein and the key determinant of mechanical and functional properties of tissues and organs. Proper balance between synthesis and degradation of collagen molecules is critical for maintaining normal physiological functions. In addition, collagen influences tumor development and drug delivery, which makes it a potential cancer therapy target. Using second harmonic generation, two-photon excited fluorescence microscopy, and spectrofluorimetry, we show that the natural pigment hypericin induces photosensitized destruction of collagen-based tissues. We demonstrate that hypericin-mediated processes in collagen fibers are irreversible and may be used for the treatment of cancer and collagen-related disorders.

Binding-Induced Fluorescence of Serotonin Transporter Ligands

DEFF Research Database (Denmark)

Wilson, James; Ladefoged, Lucy Kate; Babinchak, Michael

2014-01-01

The binding-induced fluorescence of 4-(4-(dimethylamino)-phenyl)-1-methylpyridinium (APP(+)) and two new serotonin transporter (SERT)-binding fluorescent analogues, 1-butyl-4-[4-(1-dimethylamino)phenyl]-pyridinium bromide (BPP(+)) and 1-methyl-4-[4-(1-piperidinyl)phenyl]-pyridinium (PPP(+)), has...

Surface plasmon-enhanced molecular fluorescence induced by gold nanostructures

International Nuclear Information System (INIS)

Teng, Y.; Ueno, K.; Shi, X.; Aoyo, D.; Misawa, H.; Qiu, J.

2012-01-01

The authors report on surface plasmon-enhanced fluorescence of Eosin Y molecules induced by gold nanostructures. Al 2 O 3 films deposited by atomic layer deposition with sub-nanometer resolution were used as the spacer layer to control the distance between molecules and the gold surface. As the thickness of the Al 2 O 3 film increased, the fluorescence intensity first increased and then decreased. The highest enhancement factor is achieved with a 1 nm Al 2 O 3 film. However, the trend for the fluorescence lifetime is the opposite. It first decreased and then increased. The changes in the fluorescence quantum yield were also calculated. The yield shows a similar trend to the fluorescence intensity. The competition between the surface plasmon-induced increase in the radiative decay rate and the gold-induced fluorescence quenching is responsible for the observed phenomenon. In addition, this competition strongly depends on the thickness of the spacer layer between Eosin Y molecules and the gold surface. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Magnesium sulfate reduces formalin-induced orofacial pain in rats with normal magnesium serum levels.

Science.gov (United States)

Srebro, Dragana P; Vučković, Sonja M; Dožić, Ivan S; Dožić, Branko S; Savić Vujović, Katarina R; Milovanović, Aleksandar P; Karadžić, Branislav V; Prostran, Milica Š

2018-02-01

In humans, orofacial pain has a high prevalence and is often difficult to treat. Magnesium is an essential element in biological a system which controls the activity of many ion channels, neurotransmitters and enzymes. Magnesium produces an antinociceptive effect in neuropathic pain, while in inflammatory pain results are not consistent. We examined the effects of magnesium sulfate using the rat orofacial formalin test, a model of trigeminal pain. Male Wistar rats were injected with 1.5% formalin into the perinasal area, and the total time spent in pain-related behavior (face rubbing) was quantified. We also spectrophotometrically determined the concentration of magnesium and creatine kinase activity in blood serum. Magnesium sulfate administered subcutaneously (0.005-45mg/kg) produced significant antinociception in the second phase of the orofacial formalin test in rats at physiological serum concentration of magnesium. The effect was not dose-dependent. The maximum antinociceptive effect of magnesium sulfate was about 50% and was achieved at doses of 15 and 45mg/kg. Magnesium did not affect increase the levels of serum creatine kinase activity. Preemptive systemic administration of magnesium sulfate as the only drug can be used to prevent inflammatory pain in the orofacial region. Its analgesic effect is not associated with magnesium deficiency. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Laser-induced fluorescence imaging of bacteria

Science.gov (United States)

Hilton, Peter J.

1998-12-01

This paper outlines a method for optically detecting bacteria on various backgrounds, such as meat, by imaging their laser induced auto-fluorescence response. This method can potentially operate in real-time, which is many times faster than current bacterial detection methods, which require culturing of bacterial samples. This paper describes the imaging technique employed whereby a laser spot is scanned across an object while capturing, filtering, and digitizing the returned light. Preliminary results of the bacterial auto-fluorescence are reported and plans for future research are discussed. The results to date are encouraging with six of the eight bacterial strains investigated exhibiting auto-fluorescence when excited at 488 nm. Discrimination of these bacterial strains against red meat is shown and techniques for reducing background fluorescence discussed.

Toxic effects of formalin-treated cadaver on medical students, staff ...

African Journals Online (AJOL)

Noha Selim Mohamed Elshaer

2017-01-02

Jan 2, 2017 ... Formalin-exposed staff reported symptoms of skin disorders as drying (75%), ..... rent research, 6.2% of the formalin-exposed staff had abnormal ..... Khaliq F, Tripathi P. Acute effects of formalin on pulmonary functions in gross.

Characterization of type I, II, III, IV, and V collagens by time-resolved laser-induced fluorescence spectroscopy

Science.gov (United States)

Marcu, Laura; Cohen, David; Maarek, Jean-Michel I.; Grundfest, Warren S.

2000-04-01

The relative proportions of genetically distinct collagen types in connective tissues vary with tissue type and change during disease progression, development, wound healing, aging. This study aims to 1) characterize the spectro- temporal fluorescence emission of fiber different types of collagen and 2) assess the ability of time-resolved laser- induced fluorescence spectroscopy to distinguish between collagen types. Fluorescence emission of commercially available purified samples was induced with nitrogen laser excitation pulses and detected with a MCP-PMT connected to a digital storage oscilloscope. The recorded time-resolved emission spectra displayed distinct fluorescence emission characteristics for each collagen type. The time domain information complemented the spectral domain intensity data for improved discrimination between different collagen types. Our results reveal that analysis of the fluorescence emission can be used to characterize different species of collagen. Also, the results suggest that time-resolved spectroscopy can be used for monitoring of connective tissue matrix composition changes due to various pathological and non-pathological conditions.

Ultratrace analysis of transuranic actinides by laser-induced fluorescence

Science.gov (United States)

Miller, S.M.

1983-10-31

Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

Time-resolved laser-induced fluorescence system

Science.gov (United States)

Bautista, F. J.; De la Rosa, J.; Gallegos, F. J.

2006-02-01

Fluorescence methods are being used increasingly in the measurement of species concentrations in gases, liquids and solids. Laser induced fluorescence is spontaneous emission from atoms or molecules that have been excited by laser radiation. Here we present a time resolved fluorescence instrument that consists of a 5 μJ Nitrogen laser (337.1 nm), a sample holder, a quartz optical fiber, a spectrometer, a PMT and a PC that allows the measurement of visible fluorescence spectra (350-750 nm). Time response of the system is approximately 5 ns. The instrument has been used in the measurement of colored bond paper, antifreeze, diesel, cochineal pigment and malignant tissues. The data acquisition was achieved through computer control of a digital oscilloscope (using General Purpose Interface Bus GPIB) and the spectrometer via serial (RS232). The instrument software provides a graphic interface that lets make some data acquisition tasks like finding fluorescence spectra, and fluorescence lifetimes. The software was developed using the Lab-View 6i graphic programming package and can be easily managed in order to add more functions to it.

Laser induced fluorescence of some plant leaves

International Nuclear Information System (INIS)

Helmi, M.S.; Mohamed, M.M.; Amer, R.; Elshazly, O.; Elraey, M.

1992-01-01

Laser induced fluorescence (LIF) is successfully used as a technique for remote detection of spectral characteristics of some plants. A pulsed nitrogen laser at 337.1 nm is used to excite cotton, corn and rice leaves. The fluorescence spectrum is detected in the range from 340 nm to 820 nm. It is found that, these plant leaves have common fluorescence maxima at 440 nm, 685 nm and 740 nm. plant leaves are also found to be identifiable by the ratio of the fluorescence intensity at 440 nm to that at 685 nm. The present technique can be further used as a means of assessing, remotely, plant stresses. 5 fig

Identifikasi Formalin pada Bakso yang Dijual pada Beberapa Tempat di Kota Padang

Directory of Open Access Journals (Sweden)

Faradila .

2014-05-01

Full Text Available AbstrakKonsumsi makanan cepat saji saat ini telah menjadi kebiasaan makan bagi masyarakat Indonesia. Salah satu makanan cepat saji yang popular adalah bakso, namun saat ini sering dijumpai penggunaan bahan tambahan non pangan di dalam bakso yaitu formalin. Penggunaan formalin sudah dilarang dalam makanan berdasarkan peraturan Menteri Kesehatan No. 1168 tahun 1999, tetapi pada kenyataannya masih ada produsen makanan yang memproduksi makanan mengandung formalin. Salah satu makanan yang sering ditemukan berformalin adalah bakso. Tujuan penelitian ini adalah untuk mengidentifikasi apakah terdapat formalin pada bakso yang dijual di Kota Padang. 42 sampel yang diidentifikasi diambil dari pedagang bakso gerobak, warung bakso, serta rumah makan franchise di beberapa lokasi dengan jumlah pedagang bakso terbanyak. Pemeriksaan kualitatif dilakukan dengan menggunakan Test Kit Formalin yang terdiri atas cairan pereaksi I dan serbuk pereaksi II. Hasil penelitian menunjukkan bahwa 20 sampel dari 42 sampel yang diidentifikasi dilaboratorium positif mengandung formalin (47,6%. Bedasarkan hasil yang didapatkan dapat disimpulkan bahwa hampir separuh bakso yang dijual di Kota Padang mengandung formalin.Kata kunci: Bakso, FormalinAbstractNow a days, the consumption of fast food has become an eating pattern for Indonesian. One of the most popular fast food is meatball, but today, we often found that the producents add a non food addition ingredient in the meatball that we call formalin. The use of formalin actually has been prohibited used in food based on the Peraturan Menteri Kesehatan No.1168 tahun 1999, but in fact, there are food producent that produce food with formalin. One of the food is meat ball. The objective of this research is to identifying whether there are formalin in meatballs that sold in padang. 42 samples that identified taken from mobile vendor, meatball restaurant and franchise restaurant in several locations with the greatest numbers of

Satellite-detected fluorescence reveals global physiology of ocean phytoplankton

Directory of Open Access Journals (Sweden)

M. J. Behrenfeld

2009-05-01

Full Text Available Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of quenching-corrected fluorescence quantum yields reveal a striking consistency with anticipated patterns of iron availability. High fluorescence quantum yields are typically found in low iron waters, while low quantum yields dominate regions where other environmental factors are most limiting to phytoplankton growth. Specific properties of photosynthetic membranes are discussed that provide a mechanistic view linking iron stress to satellite-detected fluorescence. Our results present satellite-based fluorescence as a valuable tool for evaluating nutrient stress predictions in ocean ecosystem models and give the first synoptic observational evidence that iron plays an important role in seasonal phytoplankton dynamics of the Indian Ocean. Satellite fluorescence may also provide a path for monitoring climate-phytoplankton physiology interactions and improving descriptions of phytoplankton light use efficiencies in ocean productivity models.

Formalin-induced behavioural hypersensitivity and neuronal hyperexcitability are mediated by rapid protein synthesis at the spinal level

Science.gov (United States)

Asante, Curtis O; Wallace, Victoria C; Dickenson, Anthony H

2009-01-01

Background The mammalian target of rapamycin (mTOR) is a key regulator of mRNA translation whose action can be inhibited by the drug rapamycin. Forms of long-term plasticity require protein synthesis and evidence indicates that mRNA in dendrites, axon terminals and cell bodies is essential for long-term synaptic plasticity. Specific to pain, shifts in pain thresholds and responsiveness are an expression of neuronal plasticity and this likely contributes to persistent pain. We investigated this by inhibiting the activity of mTOR with rapamycin at the spinal level, of rats that were subjected to the formalin test, using both behavioural and electrophysiological techniques. Results For in vivo electrophysiology, Sprague Dawley rats were fully anaesthetised and single-unit extracellular recordings were obtained from lamina V wide dynamic range (WDR) dorsal horn spinal neurones at the region where input is received from the hind paw. Neuronal responses from naive rats showed that rapamycin-sensitive pathways were important in nociceptive-specific C-fibre mediated transmission onto WDR neurones as well mechanically-evoked responses since rapamycin was effective in attenuating these measures. Formalin solution was injected into the hind paw prior to which, rapamycin or vehicle was applied directly onto the exposed spinal cord. When rapamycin was applied to the spinal cord prior to hind paw formalin injection, there was a significant attenuation of the prolonged second phase of the formalin test, which comprises continuing afferent input to the spinal cord, neuronal hyperexcitability and an activated descending facilitatory drive from the brainstem acting on spinal neurones. In accordance with electrophysiological data, behavioural studies showed that rapamycin attenuated behavioural hypersensitivity elicited by formalin injection into the hind paw. Conclusion We conclude that mTOR has a role in maintaining persistent pain states via mRNA translation and thus protein

Formalin-induced behavioural hypersensitivity and neuronal hyperexcitability are mediated by rapid protein synthesis at the spinal level

Directory of Open Access Journals (Sweden)

Wallace Victoria C

2009-06-01

Full Text Available Abstract Background The mammalian target of rapamycin (mTOR is a key regulator of mRNA translation whose action can be inhibited by the drug rapamycin. Forms of long-term plasticity require protein synthesis and evidence indicates that mRNA in dendrites, axon terminals and cell bodies is essential for long-term synaptic plasticity. Specific to pain, shifts in pain thresholds and responsiveness are an expression of neuronal plasticity and this likely contributes to persistent pain. We investigated this by inhibiting the activity of mTOR with rapamycin at the spinal level, of rats that were subjected to the formalin test, using both behavioural and electrophysiological techniques. Results For in vivo electrophysiology, Sprague Dawley rats were fully anaesthetised and single-unit extracellular recordings were obtained from lamina V wide dynamic range (WDR dorsal horn spinal neurones at the region where input is received from the hind paw. Neuronal responses from naive rats showed that rapamycin-sensitive pathways were important in nociceptive-specific C-fibre mediated transmission onto WDR neurones as well mechanically-evoked responses since rapamycin was effective in attenuating these measures. Formalin solution was injected into the hind paw prior to which, rapamycin or vehicle was applied directly onto the exposed spinal cord. When rapamycin was applied to the spinal cord prior to hind paw formalin injection, there was a significant attenuation of the prolonged second phase of the formalin test, which comprises continuing afferent input to the spinal cord, neuronal hyperexcitability and an activated descending facilitatory drive from the brainstem acting on spinal neurones. In accordance with electrophysiological data, behavioural studies showed that rapamycin attenuated behavioural hypersensitivity elicited by formalin injection into the hind paw. Conclusion We conclude that mTOR has a role in maintaining persistent pain states via m

Comparison of polyvinyl alcohol- and formalin-preserved fecal specimens in the formalin-ether sedimentation technique for parasitological examination.

OpenAIRE

Carroll, M J; Cook, J; Turner, J A

1983-01-01

A total of 965 paired fecal specimens preserved in polyvinyl alcohol fixative and Formalin were processed by the Formalin-ether sedimentation technique. The effectiveness of the concentration procedures with material from each preservative was determined by comparing both diagnostic efficiency (percent identified) and quantitative egg and semiquantitative cyst counts. Of the 319 infections, 69.5% were detected in concentrates from both preservatives, 6.9% from polyvinyl alcohol only, and 23.5...

Accidental intraoral formalin injection: a rare case report

Directory of Open Access Journals (Sweden)

Ramakant Dandriyal

2014-12-01

Full Text Available Formalin is a hazardous chemical that needs cautious handling and special storage. Owing to its disinfectant and fixative (i.e. for preserving pathologic tissue specimens in histopathology properties, it is widely used in dentistry. Although, the terms formaldehyde and formalin are often confused as being identical, these are different as to the concentrations of the primary component i.e. formaldehyde. In fact, the common fixative available as 10% neutral buffered formalin is actually a 4% solution of formaldehyde (i.e., a 10% solution made from a 37-40% commercially pure formaldehyde solution. This case report describes an unfortunate case of accidental injection instead of local anesthetic, of formalin into the pterygomandibular space in a 35-year old woman during inferior alveolar nerve block for surgical removal of impacted lower right third molar and its successful management by cautious debridement (under both local and general anesthesia and empirical drug therapy (utilizing analgesics and antibiotics.

Fluorescent zinc sensor with minimized proton-induced interferences: photophysical mechanism for fluorescence turn-on response and detection of endogenous free zinc ions.

Science.gov (United States)

Kwon, Ji Eon; Lee, Sumin; You, Youngmin; Baek, Kyung-Hwa; Ohkubo, Kei; Cho, Jaeheung; Fukuzumi, Shunichi; Shin, Injae; Park, Soo Young; Nam, Wonwoo

2012-08-20

A new fluorescent zinc sensor (HNBO-DPA) consisting of 2-(2'-hydroxy-3'-naphthyl)benzoxazole (HNBO) chromophore and a di(2-picolyl)amine (DPA) metal chelator has been prepared and examined for zinc bioimaging. The probe exhibits zinc-induced fluorescence turn-on without any spectral shifts. Its crystal structure reveals that HNBO-DPA binds a zinc ion in a pentacoordinative fashion through the DPA and HNBO moieties. Steady-state photophysical studies establish zinc-induced deprotonation of the HNBO group. Nanosecond and femtosecond laser flash photolysis and electrochemical measurements provide evidence for zinc-induced modulation of photoinduced electron transfer (PeT) from DPA to HNBO. Thus, the zinc-responsive fluorescence turn-on is attributed to suppression of PeT exerted by deprotonation of HNBO and occupation of the electron pair of DPA, a conclusion that is further supported by density functional theory and time-dependent density functional theory (DFT/TD-DFT) calculations. Under physiological conditions (pH 7.0), the probe displays a 44-fold fluorescence turn-on in response to zinc ions with a K(d) value of 12 pM. The fluorescent response of the probe to zinc ions is conserved over a broad pH range with its excellent selectivity for zinc ions among biologically relevant metal ions. In particular, its sensing ability is not altered by divalent transition metal ions such as Fe(II), Cu(II), Cd(II), and Hg(II). Cell experiments using HNBO-DPA show its suitability for monitoring intracellular zinc ions. We have also demonstrated applicability of the probe to visualize intact zinc ions released from cells that undergo apoptosis. More interestingly, zinc-rich pools in zebrafish embryos are traced with HNBO-DPA during early developmental stages. The results obtained from the in vitro and in vivo imaging studies demonstrate the practical usefulness of the probe to detect zinc ions.

Effects of Hydroalcoholic Extract of Tanacetum Sonbolii (Asteraceae on Pain-related Behaviors during Formalin Test in Mice

Directory of Open Access Journals (Sweden)

Mohammad Sofiabadi

2014-05-01

Full Text Available Introduction: Tanacetum sonbolii (Asteraceae is an endemic species in Iran. In the present study, we examined the effects of Tanacetum sonbolii hydroalcoholic extract on the formalin test in mice. Methods: 126 Swiss albino mice weighing 230-280g were used as subjects. The formalin test was performed on two control groups (marked as intact and saline groups n = 6 in each group and an experimental group. In all groups, the formalin test was recorded for 60 min after administration of extract and drugs in mice. Results: The results showed that Tanacetum sonbolii (150 and 300 mg/kg produced significant antinociception in phase 2. In addition, different doses of Tanacetum sonbolii extract (600, 900 and 1200 mg/kg also induced antinociceptive effects in phase1 and phase 2. On the other hand, morphine could induce antinociception in a dose-dependent manner. Diclofenac (10 mg/kg failed to affect the pain scores compared to Tanacetum sonbolii (300 mg/kg group. Discussion: It seems that administration of hydroalcoholic extract of Tanacetum sonbolii has the potential to relieve pain through both central and peripheral mechanisms in persistent inflammatory nociception.

Fluorescence Imaging Reveals Surface Contamination

Science.gov (United States)

Schirato, Richard; Polichar, Raulf

1992-01-01

In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

5-ALA induced fluorescent image analysis of actinic keratosis

Science.gov (United States)

Cho, Yong-Jin; Bae, Youngwoo; Choi, Eung-Ho; Jung, Byungjo

2010-02-01

In this study, we quantitatively analyzed 5-ALA induced fluorescent images of actinic keratosis using digital fluorescent color and hyperspectral imaging modalities. UV-A was utilized to induce fluorescent images and actinic keratosis (AK) lesions were demarcated from surrounding the normal region with different methods. Eight subjects with AK lesion were participated in this study. In the hyperspectral imaging modality, spectral analysis method was utilized for hyperspectral cube image and AK lesions were demarcated from the normal region. Before image acquisition, we designated biopsy position for histopathology of AK lesion and surrounding normal region. Erythema index (E.I.) values on both regions were calculated from the spectral cube data. Image analysis of subjects resulted in two different groups: the first group with the higher fluorescence signal and E.I. on AK lesion than the normal region; the second group with lower fluorescence signal and without big difference in E.I. between two regions. In fluorescent color image analysis of facial AK, E.I. images were calculated on both normal and AK lesions and compared with the results of hyperspectral imaging modality. The results might indicate that the different intensity of fluorescence and E.I. among the subjects with AK might be interpreted as different phases of morphological and metabolic changes of AK lesions.

Hyperspectral solar-induced chlorophyll fluorescence of urban tree leaves: Analyses and applications

Science.gov (United States)

Van Wittenberghe, Shari

Solar energy is the primary energy source for life on Earth which is converted into chemical energy through photosynthesis by plants, algae and cyanobacteria, releasing fuel for the organisms' activities. To dissipate excess of absorbed light energy, plants emit chlorophyll (Chl) fluorescence (650-850 nm) from the same location where photosynthesis takes place. Hence, it provides information on the efficiency of primary energy conversion. From this knowledge, many applications on vegetation and crop stress monitoring could be developed, a necessity for our planet under threat of a changing global climate. Even though the Chl fluorescence signal is weak against the intense reflected radiation background, methods for retrieving the solar-induced Chl fluorescence have been refined over the last years, both at leaf and airborne scale. However, a lack of studies on solar-induced Chl fluorescence gives difficulties for the interpretation of the signal. Within this thesis, hyperspectral upward and downward solar-induced Chl fluorescence is measured at leaf level. Fluorescence yield (FY) is calculated as well as different ratios characterizing the emitted Chl fluorescence shape. The research in this PhD dissertation illustrates the influence of several factors on the solar-induced Chl fluorescence signal. For instance, both the intensity of FY and its spectral shape of urban tree leaves are able to change under influence of stress factors such as traffic air pollution. This shows how solar-induced Chl fluorescence could function as an early stress indicator for vegetation. Further, it is shown that the signal contains information on the ultrastructure of the photosynthetic apparatus. Also, it is proven that the leaf anatomical structure and related light scattering properties play a role in the partitioning between upward and downward Chl fluorescence emission. All these findings indicate how the Chl fluorescence spectrum is influenced by factors which also influence

Multicolor Fluorescence Writing Based on Host-Guest Interactions and Force-Induced Fluorescence-Color Memory.

Science.gov (United States)

Matsunaga, Yuki; Yang, Jye-Shane

2015-06-26

A new strategy is reported for multicolor fluorescence writing on thin solid films with mechanical forces. This concept is illustrated by the use of a green-fluorescent pentiptycene derivative 1, which forms variably colored fluorescent exciplexes: a change from yellow to red was observed with anilines, and fluorescence quenching (a change to black) occurred in the presence of benzoquinone. Mechanical forces, such as grinding and shearing, induced a crystalline-to-amorphous phase transition in both the pristine and guest-adsorbed solids that led to a change in the fluorescence color (mechanofluorochromism) and a memory of the resulting color. Fluorescence drawings of five or more colors were created on glass or paper and could be readily erased by exposure to air and dichloromethane fumes. The structural and mechanistic aspects of the observations are also discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ion beam induced fluorescence imaging in biological systems

International Nuclear Information System (INIS)

Bettiol, Andrew A.; Mi, Zhaohong; Vanga, Sudheer Kumar; Chen, Ce-belle; Tao, Ye; Watt, Frank

2015-01-01

Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (<100 nm), a sensitive detection system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique

Molecular detection of Coxiella burnetii from the formalin-fixed tissues of Q fever patients with acute hepatitis.

Directory of Open Access Journals (Sweden)

Young-Rock Jang

Full Text Available Serologic diagnosis is one of the most widely used diagnostic methods for Q fever, but the window period in antibody response of 2 to 3 weeks after symptom onset results in significant diagnostic delay. We investigated the diagnostic utility of Q fever PCR from formalin-fixed liver tissues in Q fever patients with acute hepatitis.We reviewed the clinical and laboratory data in patients with Q fever hepatitis who underwent liver biopsy during a 17-year period, and whose biopsied tissues were available. We also selected patients who revealed granuloma in liver biopsy and with no Q fever diagnosis within the last 3 years as control. Acute Q fever hepatitis was diagnosed if two or more of the following clinical, serologic, or histopathologic criteria were met: (1 an infectious hepatitis-like clinical feature such as fever (≥ 38°C with elevated hepatic transaminase levels; (2 exhibition of a phase II immunoglobulin G (IgG antibodies titer by IFA of ≥ 1:128 in single determination, or a four-fold or greater rise between two separate samples obtained two or more weeks apart; (3 histologic finding of biopsy tissue showing characteristic fibrin ring granuloma.A total of 11 patients with acute Q fever hepatitis were selected and analyzed. Of the 11 patients, 3 (27% had exposure to zoonotic risk factors and 7 (63% met the serologic criteria. Granulomas with either circumferential or radiating fibrin deposition were observed in 10 cases on liver biopsy and in 1 case on bone marrow biopsy. 8 (73% revealed positive Coxiella burnetii PCR from their formalin-fixed liver tissues. In contrast, none of 10 patients with alternative diagnosis who had hepatic granuloma revealed positive C. burnetii PCR from their formalin-fixed liver tissues.Q fever PCR from formalin-fixed liver tissues appears to be a useful adjunct for diagnosing Q fever hepatitis.

Laser-induced fluorescence detection strategies for sodium atoms and compounds in high-pressure combustors

Science.gov (United States)

Weiland, Karen J. R.; Wise, Michael L.; Smith, Gregory P.

1993-01-01

A variety of laser-induced fluorescence schemes were examined experimentally in atmospheric pressure flames to determine their use for sodium atom and salt detection in high-pressure, optically thick environments. Collisional energy transfer plays a large role in fluorescence detection. Optimum sensitivity, at the parts in 10 exp 9 level for a single laser pulse, was obtained with the excitation of the 4p-3s transition at 330 nm and the detection of the 3d-3p fluorescence at 818 nm. Fluorescence loss processes, such as ionization and amplified spontaneous emission, were examined. A new laser-induced atomization/laser-induced fluorescence detection technique was demonstrated for NaOH and NaCl. A 248-nm excimer laser photodissociates the salt molecules present in the seeded flames prior to atom detection by laser-induced fluorescence.

Transient light-induced intracellular oxidation revealed by redox biosensor

Energy Technology Data Exchange (ETDEWEB)

Kolossov, Vladimir L., E-mail: viadimer@illinois.edu [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Beaudoin, Jessica N. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Hanafin, William P. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); DiLiberto, Stephen J. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Kenis, Paul J.A. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801 (United States); Rex Gaskins, H. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 S. Lincoln Avenue, Urbana, IL 61801 (United States); Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 S. Goodwin Avenue, Urbana, IL 61801 (United States)

2013-10-04

Highlights: •Time-resolved live cell imaging revealed light-induced oxidation. •Only the roGFP probe fused with glutaredoxin reveals photooxidation. •The transient oxidation is rapidly reduced by the cytosolic antioxidant system. •Intracellular photooxidation is media-dependent. •Oxidation is triggered exclusively by exposure to short wavelength excitation. -- Abstract: We have implemented a ratiometric, genetically encoded redox-sensitive green fluorescent protein fused to human glutaredoxin (Grx1-roGFP2) to monitor real time intracellular glutathione redox potentials of mammalian cells. This probe enabled detection of media-dependent oxidation of the cytosol triggered by short wavelength excitation. The transient nature of light-induced oxidation was revealed by time-lapse live cell imaging when time intervals of less than 30 s were implemented. In contrast, transient ROS generation was not observed with the parental roGFP2 probe without Grx1, which exhibits slower thiol-disulfide exchange. These data demonstrate that the enhanced sensitivity of the Grx1-roGFP2 fusion protein enables the detection of short-lived ROS in living cells. The superior sensitivity of Grx1-roGFP2, however, also enhances responsiveness to environmental cues introducing a greater likelihood of false positive results during image acquisition.

Transient light-induced intracellular oxidation revealed by redox biosensor

International Nuclear Information System (INIS)

Kolossov, Vladimir L.; Beaudoin, Jessica N.; Hanafin, William P.; DiLiberto, Stephen J.; Kenis, Paul J.A.; Rex Gaskins, H.

2013-01-01

Highlights: •Time-resolved live cell imaging revealed light-induced oxidation. •Only the roGFP probe fused with glutaredoxin reveals photooxidation. •The transient oxidation is rapidly reduced by the cytosolic antioxidant system. •Intracellular photooxidation is media-dependent. •Oxidation is triggered exclusively by exposure to short wavelength excitation. -- Abstract: We have implemented a ratiometric, genetically encoded redox-sensitive green fluorescent protein fused to human glutaredoxin (Grx1-roGFP2) to monitor real time intracellular glutathione redox potentials of mammalian cells. This probe enabled detection of media-dependent oxidation of the cytosol triggered by short wavelength excitation. The transient nature of light-induced oxidation was revealed by time-lapse live cell imaging when time intervals of less than 30 s were implemented. In contrast, transient ROS generation was not observed with the parental roGFP2 probe without Grx1, which exhibits slower thiol-disulfide exchange. These data demonstrate that the enhanced sensitivity of the Grx1-roGFP2 fusion protein enables the detection of short-lived ROS in living cells. The superior sensitivity of Grx1-roGFP2, however, also enhances responsiveness to environmental cues introducing a greater likelihood of false positive results during image acquisition

Changes in the fluorescence of the Caribbean coral Montastraea faveolata during heat-induced bleaching

Science.gov (United States)

Zawada, David G.; Jaffe, J.S.

2003-01-01

In order to evaluate the response of commonly occurring green and orange fluorescent host-based pigments, a thermal stress experiment was performed on specimens of the Caribbean coral Montastraea faveolata. Seven paired samples were collected from a small oceanic reef near Lee Stocking Island in the Bahamas. Seven of the fourteen corals were subjected to elevated temperatures for 28 d, followed by a recovery period lasting 53 d. Throughout the experiment, high-resolution (~400 µm pixel-1) multispectral images of induced fluorescence were recorded at wavelengths corresponding to the green and orange host pigments, plus chlorophyll. These images revealed that the fluorescence of both host pigments was concentrated at polyp centers and declined by 70–90% in regions between polyps. Chlorophyll fluorescence, however, was distributed almost uniformly across the entire coral surface, but with decreases of 10–30% around polyp centers. A normalized difference ratio between the green and orange pigments (GO ratio) was developed to facilitate comparison with chlorophyll fluorescence as a bleaching indicator. Analysis showed a high correspondence between a sustained GO ratio of less than zero and the death of corals. Finally, this ratio was resistant to contamination from other sources of chlorophyll fluorescence, such as filamentous algae.

Unusual expression of red fluorescence at M phase induced by anti-microtubule agents in HeLa cells expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci)

Energy Technology Data Exchange (ETDEWEB)

Honda-Uezono, Asumi [Section of Oral Radiation Oncology, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Section of Maxillofacial Surgery, Department of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Kaida, Atsushi [Section of Oral Radiation Oncology, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Michi, Yasuyuki; Harada, Kiyoshi [Section of Maxillofacial Surgery, Department of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Hayashi, Yoshiki; Hayashi, Yoshio [Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392 (Japan); Miura, Masahiko, E-mail: masa.mdth@tmd.ac.jp [Section of Oral Radiation Oncology, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan)

2012-11-16

Highlights: Black-Right-Pointing-Pointer Fucci visualizes cell cycle by green and red fluorescence. Black-Right-Pointing-Pointer Plinabulin, induced unusual red fluorescence at M-phase in HeLa-Fucci cells. Black-Right-Pointing-Pointer The unusual pattern was followed by mitotic catastrophe. Black-Right-Pointing-Pointer The unusual pattern may be an early indicator of cell death in HeLa cells. -- Abstract: Plinabulin (NPI-2358) is a novel microtubule-depolymerizing agent. In HeLa cells, plinabulin arrests the cell-cycle at M phase and subsequently induces mitotic catastrophe. To better understand the effects on this compound on the cell-cycle, we used the fluorescent ubiquitination-based cell cycle indicator (Fucci), which normally enables G1 and S/G2/M cells to emit red and green fluorescence, respectively. When HeLa-Fucci cells were treated with 50 nM plinabulin, cells began to fluoresce both green and red in an unusual pattern; most cells exhibited the new pattern after 24 h of treatment. X-irradiation efficiently induced G2 arrest in plinabulin-treated cells and significantly retarded the emergence of the unusual pattern, suggesting that entering M phase is essential for induction of the pattern. By simultaneously visualizing chromosomes with GFP-histone H2B, we established that the pattern emerges after nuclear envelope breakdown but before metaphase. Pedigree assay revealed a significant relationship between the unusual expression and mitotic catastrophe. Nocodazole, KPU-133 (a more potent derivative of plinabulin), and paclitaxel also exerted similar effects. From these data, we conclude that the unusual pattern may be associated with dysregulation of late M phase-specific E3 ligase activity and mitotic catastrophe following treatment with anti-microtubule agents.

Impurity monitoring by laser-induced fluorescence techniques

International Nuclear Information System (INIS)

Gelbwachs, J.A.

1984-01-01

Laser-induced fluorescence spectroscopy can provide a highly sensitive and selective means of detecting atomic and ionic impurities. Because the photodetector can be physically isolated from the laser-excited region, these techniques can be applied to monitoring in hostile environments. The basic concepts behind fluorescence detection are reviewed. Saturated optical excitation is shown to maximize impurity atom emission yield while mitigating effects of laser intensity fluctuations upon absolute density calibration. Monitoring in high- and low-pressure monitoring environments is compared. Methods to improve detection sensitivity by luminescence background suppression are presented

Revealing the Raft Domain Organization in the Plasma Membrane by Single-Molecule Imaging of Fluorescent Ganglioside Analogs.

Science.gov (United States)

Suzuki, Kenichi G N; Ando, Hiromune; Komura, Naoko; Konishi, Miku; Imamura, Akihiro; Ishida, Hideharu; Kiso, Makoto; Fujiwara, Takahiro K; Kusumi, Akihiro

2018-01-01

Gangliosides have been implicated in a variety of physiological processes, particularly in the formation and function of raft domains in the plasma membrane. However, the scarcity of suitable fluorescent ganglioside analogs had long prevented us from determining exactly how gangliosides perform their functions in the live-cell plasma membrane. With the development of new fluorescent ganglioside analogs, as described by Komura et al. (2017), this barrier has been broken. We can now address the dynamic behaviors of gangliosides in the live-cell plasma membrane, using fluorescence microscopy, particularly by single-fluorescent molecule imaging and tracking. Single-molecule tracking of fluorescent GM1 and GM3 revealed that these molecules are transiently and dynamically recruited to monomers (monomer-associated rafts) and homodimer rafts of the raftophilic GPI-anchored protein CD59 in quiescent cells, with exponential residency times of 12 and 40ms, respectively, in a manner dependent on raft-lipid interactions. Upon CD59 stimulation, which induces CD59-cluster signaling rafts, the fluorescent GM1 and GM3 analogs were recruited to the signaling rafts, with a lifetime of 48ms. These results represent the first direct evidence that GPI-anchored receptors and gangliosides interact in a cholesterol-dependent manner. Furthermore, they show that gangliosides continually move in and out of rafts that contain CD59 in an extremely dynamic manner, with much higher frequency than expected previously. Such studies would not have been possible without fluorescent ganglioside probes, which exhibit native-like behavior and single-molecule tracking. In this chapter, we review the methods for single-molecule tracking of fluorescent ganglioside analogs and the results obtained by applying these methods. © 2018 Elsevier Inc. All rights reserved.

Laser-induced fluorescence for medical diagnostics

International Nuclear Information System (INIS)

Andersson Engels, S.

1989-12-01

Laser-induced fluorescence as a tool for tissue diagnostics is discussed. Both spectrally and time-resolved fluorescence signals are studied to optimize the demarcation of diseased lesions from normal tissue. The presentation is focused on two fields of application: the identification of malignant tumours and atherosclerotic plaques. Tissue autofluorescence as well as fluorescence from administered drugs have been utilized in diseased tissue diagnosis. The fluorescence criterion for tissue diagnosis is, as far as possible, chosen to be independent of unknown fluorescence parameters, which are not correlated to the type of tissue investigated. Both a dependence on biological parameters, such as light absorption in blood, and instrumental characteristics, such as excitation pulse fluctuations and detection geometry, can be minimized. Several chemical compounds have been studied in animal experiments after intraveneous injection to verify their capacity as malignant tumour marking drugs under laser excitation and fluorescence detection. Another objective of these studies was to improve our understanding of the mechanism and chemistry behind the retention of the various drugs in tissue. The properties of a chemical which maximize its selective retention in tumours are discussed. In order to utilize this diagnostic modality, three different clinically adapted sets of instrumentation have been developed and are presented. Two of the systems are nitrogen-laser-based fluorosensors; one is a point-monitoring system with full spectral resolution and the other one is an imaging system with up to four simultaneously recorded images in different spectral bands. The third system is a low-cost point-monitoring mercury-lamp-based fluoroscence emission as well as reflection characteristics of tissue. (author)

Molecular glycopathology by capillary electrophoresis: Analysis of the N-glycome of formalin-fixed paraffin-embedded mouse tissue samples.

Science.gov (United States)

Donczo, Boglarka; Szarka, Mate; Tovari, Jozsef; Ostoros, Gyorgyi; Csanky, Eszter; Guttman, Andras

2017-06-01

Capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection was used to analyze endoglycosidase released and fluorophore-labeled N-glycans from formalin-fixed paraffin-embedded (FFPE) mouse tissue samples of lung, brain, heart, spleen, liver, kidney and intestine. The FFPE samples were first deparaffinized followed by solubilization and glycoprotein retrieval. PNGase F mediated release of the N-linked oligosaccharides was followed by labeling with aminopyrene trisulfonate. After CE-LIF glycoprofiling of the FFPE mouse tissues, the N-glycan pool of the lung specimen was subject to further investigation by exoglycosidase array based carbohydrate sequencing. Structural assignment of the oligosaccharides was accomplished by the help of the GUcal software and the associated database, based on the mobility shifts after treatments with the corresponding exoglycosidase reaction mixtures. Sixteen major N-linked carbohydrate structures were sequenced from the mouse lung FFPE tissue glycome and identified, as high mannose (3) neutral biantennary (3) sialylated monoantennary (1) and sialylated bianennary (9) oligosaccharides. Two of these latter ones also possessed alpha(1-3) linked galactose residues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toxic effects of formalin-treated cadaver on medical students, staff ...

African Journals Online (AJOL)

Background: Formaldehyde can be toxic, allergenic and carcinogenic. Evaporation of formaldehyde from formalin-treated cadavers in the anatomy dissection rooms can produce high exposure. This study was conducted to assess acute and chronic toxic effects of formalin-treated cadavers on medical students, staff ...

Laser induced fluorescence of dental caries

Science.gov (United States)

Albin, S.; Byvik, C. E.; Buoncristiani, A. M.

1988-01-01

Significant differences between the optical spectra taken from sound regions of teeth and carious regions have been observed. These differences appear both in absorption and in laser induced fluorescence spectra. Excitation by the 488 nm line of an argon ion laser beam showed a peak in the emission intensity around 553 nm for the sound dental material while the emission peak from the carious region was red-shifted by approximately 40 nm. The relative absorption of carious region was significantly higher at 488 nm; however its fluorescence intensity peak was lower by an order of magnitude compared to the sound tooth. Implications of these results for a safe, reliable and early detection of dental caries are discussed.

Preservation of biomolecules in breast cancer tissue by a formalin-free histology system

Directory of Open Access Journals (Sweden)

Morales Azorides R

2008-01-01

Full Text Available Abstract Background The potential problems associated with the use of formalin in histology, such as health hazards, degradation of RNA and cross-linking of proteins are well recognized. We describe the utilization of a formalin-free fixation and processing system for tissue detection of two important biopredictors in breast cancer – estrogen receptor and HER2 – at the RNA and protein levels. Methods Parallel sections of 62 cases of breast cancer were fixed in an alcohol-based molecular fixative and in formalin. Molecular fixative samples were processed by a novel formalin-free microwave-assisted processing system that preserves DNA, RNA and proteins. Formalin-fixed samples were processed using the conventional method. Estrogen receptor was assessed by immunohistochemistry and real-time PCR. HER2 was assessed by immunohistochemistry, FISH, CISH and real-time PCR. Results The immunohistochemical reaction for estrogen receptor was similar in molecular- and formalin-fixed samples (Spearman Rank R = 0.83, p Conclusion The formalin-free tissue fixation and processing system is a practical platform for evaluation of biomolecular markers in breast cancer and it allows reliable DNA and RNA and protein studies.

Applying fluorescence correlation spectroscopy to investigate peptide-induced membrane disruption

DEFF Research Database (Denmark)

Kristensen, Kasper; Henriksen, Jonas Rosager; Andresen, Thomas Lars

2017-01-01

to quantify leakage of fluorescent molecules of different sizes from large unilamellar lipid vesicles, thereby providing a tool for estimating the size of peptide-induced membrane disruptions. If fluorescently labeled lipids are incorporated into the membranes of the vesicles, FCS can also be used to obtain...

Laser induced fluorescence of biochemical for UV LIDAR application.

Science.gov (United States)

Gupta, L; Sharma, R C; Razdan, A K; Maini, A K

2014-05-01

Laser induced fluorescence spectroscopy in the ultraviolet regime has been used for the detection of biochemical through a fiber coupled CCD detector from a distance of 2 m. The effect of concentration and laser excitation energy on the fluorescence spectra of nicotinamide adenine dinucleotide (NADH) has been investigated. The signature fluorescence peak of NADH was centred about 460 nm. At lower concentration Raman peak centred at 405 nm was also observed. The origin of this peak has been discussed. Detection limit with the proposed set up is found to be 1 ppm.

Fluorescent-light-induced lethality and DNA repair in normal and xeroderma pigmentosum fibroblasts

International Nuclear Information System (INIS)

Ritter, M.A.; Williams, J.R.

1981-01-01

Cell survival and induction of endonuclease-sensitive sites in DNA were measured in human fibroblast cells exposed to fluorescent light or germicidal ultraviolet light. Cells from a xeroderma pigmentosum patient were hypersensitive to cell killing by fluorescent light, although less so than for germicidal ultraviolet light. Xeroderma pigmentosum cells were deficient in the removal of fluorescent light-induced endonuclease sites that are probably pyrimidine dimers, and both the xeroderma pigmentosum and normal cells removed these sites with kinetics indistinguishable from those for ultraviolet light-induced sites. A comparison of fluorescent with ultraviolet light data demonstrates that there are markedly fewer pyrimidine dimers per lethal event for fluorescent than for ultraviolet light, suggesting a major role for non-dimer damage in fluorescent lethality. (Auth.)

Detecting thermal phase transitions in corneal stroma by fluorescence micro-imaging analysis

Science.gov (United States)

Matteini, P.; Rossi, F.; Ratto, F.; Bruno, I.; Nesi, P.; Pini, R.

2008-02-01

Thermal modifications induced in corneal stroma were investigated by the use of fluorescence microscopy. Freshly extracted porcine corneas were immersed for 5 minutes in a water bath at temperatures in the 35-90°C range and stored in formalin. The samples were then sliced in 200-μm-thick transversal sections and analyzed under a stereomicroscope to assess corneal shrinkage. Fluorescence images of the thermally treated corneal samples were acquired using a slow-scan cooled CCD camera, after staining the slices with Indocyanine Green (ICG) fluorescent dye which allowed to detect fluorescence signal from the whole tissue. All measurements were performed using an inverted epifluorescence microscope equipped with a mercury lamp. The thermally-induced modifications to the corneal specimens were evaluated by studying the grey level distribution in the fluorescence images. For each acquired image, Discrete Fourier Transform (DFT) and entropy analyses were performed. The spatial distribution of DFT absolute value indicated the spatial orientation of the lamellar planes, while entropy was used to study the image texture, correlated to the stromal structural transitions. As a result, it was possible to indicate a temperature threshold value (62°C) for high thermal damage, resulting in a disorganization of the lamellar planes and in full agreement with the measured temperature for corneal shrinkage onset. Analysis of the image entropy evidenced five strong modifications in stromal architecture at temperatures of ~45°C, 53°C, 57°C, 66°C, 75°C. The proposed procedure proved to be an effective micro-imaging method capable of detecting subtle changes in corneal tissue subjected to thermal treatment.

Sorbitol as an efficient reducing agent for laser-induced copper deposition

Science.gov (United States)

Kochemirovsky, V. A.; Logunov, L. S.; Safonov, S. V.; Tumkin, I. I.; Tver'yanovich, Yu. S.; Menchikov, L. G.

2012-10-01

We have pioneered in revealing the fact that sorbitol may be used as an efficient reducing agent in the process of laser-induced copper deposition from solutions; in this case, it is possible to obtain copper lines much higher quality than by using conventional formalin.

Spatial variability of oceanic phycoerythrin spectral types derived from airborne laser-induced fluorescence emissions

Science.gov (United States)

Hoge, Frank E.; Wright, C. Wayne; Kana, Todd M.; Swift, Robert N.; Yungel, James K.

1998-07-01

We report spatial variability of oceanic phycoerythrin spectral types detected by means of a blue spectral shift in airborne laser-induced fluorescence emission. The blue shift of the phycoerythrobilin fluorescence is known from laboratory studies to be induced by phycourobilin chromophore substitution at phycoerythrobilin chromophore sites in some strains of phycoerythrin-containing marine cyanobacteria. The airborne 532-nm laser-induced phycoerythrin fluorescence of the upper oceanic volume showed distinct segregation of cyanobacterial chromophore types in a flight transect from coastal water to the Sargasso Sea in the western North Atlantic. High phycourobilin levels were restricted to the oceanic (oligotrophic) end of the flight transect, in agreement with historical ship findings. These remotely observed phycoerythrin spectral fluorescence shifts have the potential to permit rapid, wide-area studies of the spatial variability of spectrally distinct cyanobacteria, especially across interfacial regions of coastal and oceanic water masses. Airborne laser-induced phytoplankton spectral fluorescence observations also further the development of satellite algorithms for passive detection of phytoplankton pigments. Optical modifications to the NASA Airborne Oceanographic Lidar are briefly described that permitted observation of the fluorescence spectral shifts.

Laser-induced fluorescence in the detection of esophageal carcinoma

Science.gov (United States)

Wang, Kenneth K.; Gutta, Kumar; Laukka, Mark A.; Densmore, John

1995-01-01

Laser induced fluorescence (LIF) is a technique which can perform an 'optical biopsy' of gastrointestinal mucosa. LIF was performed in resected specimens using a pulsed N2-laser coupled fiberoptically to a probe. Fluorescence was measured using a 0.2 meter spectroscope with an intensified photodiode array. Measurements were made on fresh (esophagus, and adenocarcinoma. Each tissue section was examined using an optical probe consisting of a central fiber for delivering the excitation energy and a 6 fiber bundle surrounding the central fiber for detection of the fluorescence. An excitation wavelength of 337 nm was used which generated 3-ns pulses while fluorescence intensities were acquired from 300-800 nm. Spectra were obtained from each section in a standardized fashion and background spectra subtracted. Fluorescence readings were taken from 54 normal esophageal sections and 32 sections of adenocarcinoma. A fluorescence index obtained from the tumor sections was 0.68+/- 0.01 compared with 0.51+/- 0.01 for the normal sections (pesophagus with good accuracy.

Two-photon induced fluorescence and other optical effects in irradiated and doped fused silica

International Nuclear Information System (INIS)

Kramer, S.D.

1986-07-01

The objective of this program was to assess and identify irradiation techniques which could be used to modify the optical charactistics of doped fused silica. Primary emphasis was placed on determining if gamma ray or neutron bombardment of the glass would enhance certain Raman and nonlinear optical effects. In particular, the effect of irradiation on optical two photon induced fluorescence was studied in detail. The maximum radiation exposures used were 10 6 rads (Si) of gamma rays and neutron fluences of 1 x 10 14 neutrons/cm 2 . The optical measurements were made at room temperature between one and four months after irradiation. The maximum input light intensity was 10 9 watts/cm 2 at a near infrared (1.06 μ) input wavelength which was chosen to lie in a transparent spectral region of the glass. Under these experimental conditions a careful search revealed no detectable two-photon induced fluorescence in the region from 550 to 900 nm. The upper limit for the photon efficiency of this process was determined to be less than 1 x 10 -10 %. 89 refs., 12 figs

Virgin coconut oil supplementation ameliorates cyclophosphamide-induced systemic toxicity in mice.

Science.gov (United States)

Nair, S S; Manalil, J J; Ramavarma, S K; Suseela, I M; Thekkepatt, A; Raghavamenon, A C

2016-02-01

Virgin coconut oil (VCO) is an unrefined kernal oil, prepared from Cocos nucifera L., having substantial nutritional and medicinal value. Experimental studies have suggested its antioxidant, anti-inflammatory, immunostimulatory and hypolipidemic effects. The present study assesses its effect on formalin-induced chronic inflammation and cyclophosphamide (CTX)-induced systemic toxicity in murine models. Oral administration of VCO effectively reduced formalin-induced paw oedema in mice with more or less similar efficacy as that of diclofenac. The CTX-induced hike in blood urea, creatinine, thiobarbituric acid reactive substances (TBARS) and liver marker enzymes in mice was marginally decreased by VCO (8 g/kg body weight) ingestion orally. The liver and kidney catalase, superoxide dismutase and glutathione peroxidase activities, together with cellular glutathione and TBARS levels, were found to be improved in these animals. Overall the study reveals the protective efficacy of VCO against secondary toxicity induced by CTX possibly through its antioxidant and anti-inflammatory properties. © The Author(s) 2015.

Laser-Induced Fluorescence diagnostic of barium ion plasmas in the Paul Trap Simulator Experiment

International Nuclear Information System (INIS)

Chung, Moses; Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.

2005-01-01

The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. To investigate the ion plasma microstate in PTSX, including the ion density profile and the ion velocity distribution function, a laser-induced fluorescence diagnostic system is being developed as a nondestructive diagnostic. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. A feasibility study of the laser-induced fluorescence diagnostic using barium ions is presented with the characterization of a tunable dye laser. The installation of the barium ion source and the development of the laser-induced fluorescence diagnostic system are also discussed

Laser-induced fluorescence of oral mucosa cancer

Science.gov (United States)

Jaliashvili, Z. V.; Medoidze, T. D.; Melikishvili, Z. G.; Gogilashvili, K. T.

2017-10-01

The laser-induced fluorescence (LIF) spectra have been measured for cancer-infused and control mice mucosa tissues. It was established that there is quite a difference between their LIF spectral shapes. These spectral shapes are used to express the diagnostic of different states of tissues: from normal to cancer.

Modeling formalin fixation and histological processing with ribonuclease A: effects of ethanol dehydration on reversal of formaldehyde cross-links.

Science.gov (United States)

Fowler, Carol B; O'Leary, Timothy J; Mason, Jeffrey T

2008-07-01

Understanding the chemistry of protein modification by formaldehyde fixation and subsequent tissue processing is central to developing improved methods for antigen retrieval in immunohistochemistry and for recovering proteins from formalin-fixed, paraffin-embedded (FFPE) tissues for proteomic analysis. Our initial studies of single proteins, such as bovine pancreatic ribonuclease A (RNase A), in 10% buffered formalin solution revealed that upon removal of excess formaldehyde, monomeric RNase A exhibiting normal immunoreactivity could be recovered by heating at 60 degrees C for 30 min at pH 4. We next studied tissue surrogates, which are gelatin-like plugs of fixed proteins that have sufficient physical integrity to be processed using normal tissue histology. Following histological processing, proteins could be extracted from the tissue surrogates by combining heat, detergent, and a protein denaturant. However, gel electrophoresis revealed that the surrogate extracts contained a mixture of monomeric and multimeric proteins. This suggested that during the subsequent steps of tissue processing protein-formaldehyde adducts undergo further modifications that are not observed in aqueous proteins. As a first step toward understanding these additional modifications we have performed a comparative evaluation of RNase A following fixation in buffered formaldehyde alone and after subsequent dehydration in 100% ethanol by combining gel electrophoresis, chemical modification, and circular dichroism spectroscopic studies. Our results reveal that ethanol-induced rearrangement of the conformation of fixed RNase A leads to protein aggregation through the formation of large geometrically compatible hydrophobic beta-sheets that are likely stabilized by formaldehyde cross-links, hydrogen bonds, and van der Waals interactions. It requires substantial energy to reverse the formaldehyde cross-links within these sheets and regenerate protein monomers free of formaldehyde modifications

Synergism between dexketoprofen and meloxicam in an orofacial formalin test was not modified by opioid antagonists.

Science.gov (United States)

Gonzalez, Claudia; Zegpi, Carlos; Noriega, Viviana; Prieto, Juan C; Miranda, Hugo F

2011-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs for the management of acute and chronic pain. The role of the opioid system in the synergism between NSAIDs is not well characterized. Mice were injected with a 5% formalin solution (20 μl) into the upper right lip to perform an orofacial formalin test. The isobolographic method was used to determine the interaction between dexketoprofen, which is the (S)-(+) enantiomer of ketoprofen, and meloxicam co-administration. Additionally, the non-selective, opioid antagonist naltrexone, the selective δ opioid receptor (DOP) antagonist naltrindole and the selective κ opioid receptor (KOP) antagonist norbinaltorphimine were used to assess the opioid effects on this interaction. Intraperitoneal administration of dexketoprofen or meloxicam induced dose-dependent antinociception with different phase I and phase II potencies in the orofacial formalin test. Meloxicam displayed similar potencies (ED(50)) in phase I (7.20 mg/kg) and phase II (8.60 mg/kg). Dexketoprofen was more potent in phase I (19.96 mg/kg) than in phase II (50.90 mg/kg). The interactions between dexketoprofen and meloxicam were synergistic in both phases. This was determined based on the fixed ratios (1:1) of their ED(50) values, which were determined by isobolographic analysis. Furthermore, this antinociceptive activity does not seem to be modulated by opioid receptor blockers because they did not induce changes in the nature of this interaction. This finding may be relevant with regards to NSAID multi-modal analgesia where an opioid antagonist must be used.

Recognition of edible oil by using BP neural network and laser induced fluorescence spectrum

Science.gov (United States)

Mu, Tao-tao; Chen, Si-ying; Zhang, Yin-chao; Guo, Pan; Chen, He; Zhang, Hong-yan; Liu, Xiao-hua; Wang, Yuan; Bu, Zhi-chao

2013-09-01

In order to accomplish recognition of the different edible oil we set up a laser induced fluorescence spectrum system in the laboratory based on Laser induced fluorescence spectrum technology, and then collect the fluorescence spectrum of different edible oil by using that system. Based on this, we set up a fluorescence spectrum database of different cooking oil. It is clear that there are three main peak position of different edible oil from fluorescence spectrum chart. Although the peak positions of all cooking oil were almost the same, the relative intensity of different edible oils was totally different. So it could easily accomplish that oil recognition could take advantage of the difference of relative intensity. Feature invariants were extracted from the spectrum data, which were chosen from the fluorescence spectrum database randomly, before distinguishing different cooking oil. Then back propagation (BP) neural network was established and trained by the chosen data from the spectrum database. On that basis real experiment data was identified by BP neural network. It was found that the overall recognition rate could reach as high as 83.2%. Experiments showed that the laser induced fluorescence spectrum of different cooking oil was very different from each other, which could be used to accomplish the oil recognition. Laser induced fluorescence spectrum technology, combined BP neural network，was fast, high sensitivity, non-contact, and high recognition rate. It could become a new technique to accomplish the edible oil recognition and quality detection.

Numerical and structural genomic aberrations are reliably detectable in tissue microarrays of formalin-fixed paraffin-embedded tumor samples by fluorescence in-situ hybridization.

Directory of Open Access Journals (Sweden)

Heike Horn

Full Text Available Few data are available regarding the reliability of fluorescence in-situ hybridization (FISH, especially for chromosomal deletions, in high-throughput settings using tissue microarrays (TMAs. We performed a comprehensive FISH study for the detection of chromosomal translocations and deletions in formalin-fixed and paraffin-embedded (FFPE tumor specimens arranged in TMA format. We analyzed 46 B-cell lymphoma (B-NHL specimens with known karyotypes for translocations of IGH-, BCL2-, BCL6- and MYC-genes. Locus-specific DNA probes were used for the detection of deletions in chromosome bands 6q21 and 9p21 in 62 follicular lymphomas (FL and six malignant mesothelioma (MM samples, respectively. To test for aberrant signals generated by truncation of nuclei following sectioning of FFPE tissue samples, cell line dilutions with 9p21-deletions were embedded into paraffin blocks. The overall TMA hybridization efficiency was 94%. FISH results regarding translocations matched karyotyping data in 93%. As for chromosomal deletions, sectioning artefacts occurred in 17% to 25% of cells, suggesting that the proportion of cells showing deletions should exceed 25% to be reliably detectable. In conclusion, FISH represents a robust tool for the detection of structural as well as numerical aberrations in FFPE tissue samples in a TMA-based high-throughput setting, when rigorous cut-off values and appropriate controls are maintained, and, of note, was superior to quantitative PCR approaches.

Beta-induced fluorescence detection in liquid chromatography

International Nuclear Information System (INIS)

Malcolme-Lawes, D.J.; Massey, S.; Warwick, P.

1981-01-01

A theoretical analysis of beta-induced fluorescence is used to determine the factors which influence the sensitivity of the technique as applied to liquid chromatography. Equations are presented for detector response and for signal-to-noise ratios and the theoretical response for a typical detector is compared with experimentally determined values. (author)

Characterisation of estuarine intertidal macroalgae by laser-induced fluorescence

DEFF Research Database (Denmark)

Gameiro, Carla; Utkin, Andrei B.; Sousa Dias Cartaxana, Paulo Jorge

2015-01-01

The article reports the application of laser-induced fluorescence (LIF) for the assessment of macroalgae communities of estuarine intertidal areas. The method was applied for the characterisation of fifteen intertidal macroalgae species of the Tagus estuary, Portugal, and adjacent coastal area...... spectra were determined by differences in the main fluorescing pigments: phycoerythrin, phycocyanin and chlorophyll a (Chl a). In the green and brown macroalgae groups, the relative significance of the two emission maxima seems to be related to the thickness of the photosynthetic layer. In thick...... macroalgae, like Codium tomentosum or Fucus vesiculosus, the contribution of the far-red emission fluorescence peak was more significant, most probably due to re-absorption of the emitted red Chl a fluorescence within the dense photosynthetic layer. Similarly, an increase in the number of layers of the thin...

Single-Shot, Volumetrically Illuminated, Three-Dimensional, Tomographic Laser-Induced-Fluorescence Imaging in a Gaseous Free Jet

Science.gov (United States)

2016-04-28

Single-shot, volumetrically illuminated, three- dimensional, tomographic laser-induced- fluorescence imaging in a gaseous free jet Benjamin R. Halls...acquisition; (110.6955) Tomographic imaging ; (110.6960) Tomography; (280.2490) Flow diagnostics; (300.2530) Fluorescence , laser-induced...84 (1983). 2. I. van Cruyningen, A. Lozano, and R. K. Hanson, “Quantitative imaging of concentration by planar laser-induced fluorescence ,” Exp

Examining Thermally Sprayed Coats By Fluorescence Microscopy

Science.gov (United States)

Street, Kenneth W., Jr.; Leonhardt, Todd A.

1994-01-01

True flaws distinquished from those induced by preparation of specimens. Fluorescence microscopy reveals debonding, porosity, cracks, and other flaws in specimens of thermally sprayed coating materials. Specimen illuminated, and dye it contains fluoresces, emitting light at different wavelength. Filters emphasize contrast between excitation light and emission light. Specimen viewed directly or photographed on color film.

Time-synchronized continuous wave laser-induced fluorescence on an oscillatory xenon discharge.

Science.gov (United States)

MacDonald, N A; Cappelli, M A; Hargus, W A

2012-11-01

A novel approach to time-synchronizing laser-induced fluorescence measurements to an oscillating current in a 60 Hz xenon discharge lamp using a continuous wave laser is presented. A sample-hold circuit is implemented to separate out signals at different phases along a current cycle, and is followed by a lock-in amplifier to pull out the resulting time-synchronized fluorescence trace from the large background signal. The time evolution of lower state population is derived from the changes in intensity of the fluorescence excitation line shape resulting from laser-induced fluorescence measurements of the 6s(')[1/2](1)(0)-6p(')[3/2](2) xenon atomic transition at λ = 834.68 nm. Results show that the lower state population oscillates at twice the frequency of the discharge current, 120 Hz.

Laser induced fluorescence spectroscopy for FTU

International Nuclear Information System (INIS)

Hughes, T.P.

1995-07-01

Laser induced fluorescence spectroscopy (LIFS) is based on the absorption of a short pulse of tuned laser light by a group of atoms and the observation of the resulting fluorescence radiation from the excited state. Because the excitation is resonant it is very efficient, and the fluorescence can be many times brighter than the normal spontaneous emission, so low number densities of the selected atoms can be detected and measured. Good spatial resolution can be achieved by using a narrow laser beam. If the laser is sufficiently monochromatic, and it can be tuned over the absorption line profile of the selected atoms, information can also be obtained about the velocities of the atoms from the Doppler effect which can broaden and shift the line. In this report two topics are examined in detail. The first is the effect of high laser irradiance, which can cause 'power broadening' of the apparent absorption line profile. The second is the effect of the high magnetic field in FTU. Detailed calculations are given for LIFS of neutral iron and molybdenum atoms, including the Zeeman effect, and the implementation of LIFS for these atoms on FTU is discussed

Raft-based sphingomyelin interactions revealed by new fluorescent sphingomyelin analogs

Science.gov (United States)

Kinoshita, Masanao; Suzuki, Kenichi G.N.; Takada, Misa; Ano, Hikaru; Abe, Mitsuhiro; Makino, Asami; Kobayashi, Toshihide; Hirosawa, Koichiro M.; Fujiwara, Takahiro K.; Murata, Michio

2017-01-01

Sphingomyelin (SM) has been proposed to form cholesterol-dependent raft domains and sphingolipid domains in the plasma membrane (PM). How SM contributes to the formation and function of these domains remains unknown, primarily because of the scarcity of suitable fluorescent SM analogs. We developed new fluorescent SM analogs by conjugating a hydrophilic fluorophore to the SM choline headgroup without eliminating its positive charge, via a hydrophilic nonaethylene glycol linker. The new analogs behaved similarly to the native SM in terms of their partitioning behaviors in artificial liquid order-disorder phase-separated membranes and detergent-resistant PM preparations. Single fluorescent molecule tracking in the live-cell PM revealed that they indirectly interact with each other in cholesterol- and sphingosine backbone–dependent manners, and that, for ∼10–50 ms, they undergo transient colocalization-codiffusion with a glycosylphosphatidylinositol (GPI)-anchored protein, CD59 (in monomers, transient-dimer rafts, and clusters), in CD59-oligomer size–, cholesterol-, and GPI anchoring–dependent manners. These results suggest that SM continually and rapidly exchanges between CD59-associated raft domains and the bulk PM. PMID:28330937

Methotrexate-Induced Accumulation of Fluorescent Annexin V in Collagen-Induced Arthritis

Directory of Open Access Journals (Sweden)

Andreas Wunder

2005-01-01

Full Text Available We examined the accumulation of Cy5.5-labeled annexin V in the paws of mice with and without collagen-induced arthritis, with and without methotrexate (MTX treatment, by near-infrared fluorescence imaging. Fluorescence reflectance imaging (FRI of paws was performed 48 hr after MTX injection and at 10 min and 3 hr after the injection of Cy5.5-annexin V (1 nmol dye per mouse. With arthritic paws, MTX treatment caused a 7-fold increase in fluorescence intensity compared with the paws of untreated mice and a 4-fold increase compared to nonarthritic paws of MTX-treated mice (p < .001 each. Tissue samples of paws were examined histologically for Cy5.5 fluorescence and by TUNEL staining for apoptosis. Cy5.5-annexin V was seen in the hyperplastic synovia of MTX-treated mice, and TUNEL staining for apoptosis showed apoptotic cells in the hyperplastic synovia. Monitoring the uptake of Cy5.5-annexin V in arthritic paws by FRI provided a method of assessing a response to MTX, a response that was readily quantitated with simple instrumentation and that occurred before conventional measurements of treatment response.

Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy

International Nuclear Information System (INIS)

Anglos, D.; Nevin, A.

2006-01-01

Laser-induced fluorescence (LIF) spectroscopy can provide nondestructive, qualitative analysis of protein-based binding media found in artworks. Fluorescence emissions from proteins in egg yolk and egg white are due to auto fluorescent aromatic amino acids as well as other native and age-related fluorophores, but the potential of fluorescence spectroscopy for the differentiation between binding media is dependent on the choice of a suitable excitation wavelength and limited by problems in interpretation. However, a better understanding of emission spectra associated with LIF can be achieved following comparisons with total emission fluorescence spectra where a series of consecutive emission spectra are recorded over a specific range. Results using nanosecond UV laser sources for LIF of egg-based binding media are presented which are rationalised following comparisons with total emission spectra. Specifically, fluorescence is assigned to tryptophan and oxidation products of amino acids; in the case of egg yolk, fatty-acid polymerisation and age-related degradation products account for the formation of fluorophores.

Portable X-ray Fluorescence and Infrared Fluorescence Imaging Studies of Cadmium Yellow Alteration in Paintings by Edward Munch and Henri matisse in Oslo, Copenhagen, and San Francisco

DEFF Research Database (Denmark)

Mass, Jennifer; Uffelman, Erich; Buckley, Barbara

2016-01-01

-induced visible fluorescence, ultraviolet-induced infrared fluorescence, multispectral imaging, and X-ray fluorescence. Questions addressed included the following: Is the imaging method being tested comprehensive? Is it efficient at surveying an entire painting? Does it reveal the state of preservation...... and the Statens Museum for Kunst, Copenhagen. They were also tested on Edvard Munch’s The Scream (ca. 1910?, Munch Museum, Oslo). It was found that ultraviolet-induced visible fluorescence has the best ability to discriminate between altered and unaltered cadmium yellow paints (even before alteration is visible...... to the unaided eye), whereas multispectral imaging allows for the most efficient and comprehensive localization of the cadmium pigments in a work....

Binding-Induced Fluorescence of Serotonin Transporter Ligands: A Spectroscopic and Structural Study of 4-(4-(Dimethylamino)phenyl)-1-methylpyridinium (APP+) and APP+ Analogues

Science.gov (United States)

2014-01-01

The binding-induced fluorescence of 4-(4-(dimethylamino)-phenyl)-1-methylpyridinium (APP+) and two new serotonin transporter (SERT)-binding fluorescent analogues, 1-butyl-4-[4-(1-dimethylamino)phenyl]-pyridinium bromide (BPP+) and 1-methyl-4-[4-(1-piperidinyl)phenyl]-pyridinium (PPP+), has been investigated. Optical spectroscopy reveals that these probes are highly sensitive to their chemical microenvironment, responding to variations in polarity with changes in transition energies and responding to changes in viscosity or rotational freedom with emission enhancements. Molecular docking calculations reveal that the probes are able to access the nonpolar and conformationally restrictive binding pocket of SERT. As a result, the probes exhibit previously not identified binding-induced turn-on emission that is spectroscopically distinct from dyes that have accumulated intracellularly. Thus, binding and transport dynamics of SERT ligands can be resolved both spatially and spectroscopically. PMID:24460204

Detection and quantitation analysis of cocaine and metabolites in fixed liver tissue and formalin solutions.

Science.gov (United States)

Cingolani, Mariano; Cippitelli, Marcello; Froldi, Rino; Gambaro, Veniero; Tassoni, Giovanna

2004-01-01

This study reports the results of the detection and quantitation of cocaine and its metabolites in liver tissues fixed in formalin and in the formalin solutions in which the same tissues were fixed. Toxicological analyses were performed on formalin-fixed liver samples from four cases of death of cocaine abusers and on formalin solutions (10% buffered, pH 7) in which the samples were preserved. Analyses carried out at the time of autopsy on body fluids and tissues allowed identification of cocaine and the metabolite benzoylecgonine. Liver tissue samples were preserved in formalin solutions for four weeks before analysis. Results only showed the presence of benzoylecgonine in the studied materials. The mean levels of recovery of benzoylecgonine in fixed tissues were 12.31% in liver and 84.47% in formalin from liver. Results indicated that benzoylecgonine has good stability, even in biological specimens subjected to chemical fixation.

Studying electron-PAG interactions using electron-induced fluorescence

Science.gov (United States)

Narasimhan, Amrit; Grzeskowiak, Steven; Ostrander, Jonathan; Schad, Jonathon; Rebeyev, Eliran; Neisser, Mark; Ocola, Leonidas E.; Denbeaux, Gregory; Brainard, Robert L.

2016-03-01

In extreme ultraviolet (EUV) lithography, 92 eV photons are used to expose photoresists. Typical EUV resists are organic-based and chemically amplified using photoacid generators (PAGs). Upon exposure, PAGs produce acids which catalyze reactions that result in changes in solubility. In EUV lithography, photo- and secondary electrons (energies of 10- 80 eV) play a large role in PAG acid-production. Several mechanisms for electron-PAG interactions (e.g. electron trapping, and hole-initiated chemistry) have been proposed. The aim of this study is to explore another mechanism - internal excitation - in which a bound PAG electron can be excited by receiving energy from another energetic electron, causing a reaction that produces acid. This paper explores the mechanism of internal excitation through the analogous process of electron-induced fluorescence, in which an electron loses energy by transferring that energy to a molecule and that molecule emits a photon rather than decomposing. We will show and quantify electron-induced fluorescence of several fluorophores in polymer films to mimic resist materials, and use this information to refine our proposed mechanism. Relationships between the molecular structure of fluorophores and fluorescent quantum yield may aid in the development of novel PAGs for EUV lithography.

Time-resolved resonance fluorescence spectroscopy for study of chemical reactions in laser-induced plasmas.

Science.gov (United States)

Liu, Lei; Deng, Leimin; Fan, Lisha; Huang, Xi; Lu, Yao; Shen, Xiaokang; Jiang, Lan; Silvain, Jean-François; Lu, Yongfeng

2017-10-30

Identification of chemical intermediates and study of chemical reaction pathways and mechanisms in laser-induced plasmas are important for laser-ablated applications. Laser-induced breakdown spectroscopy (LIBS), as a promising spectroscopic technique, is efficient for elemental analyses but can only provide limited information about chemical products in laser-induced plasmas. In this work, time-resolved resonance fluorescence spectroscopy was studied as a promising tool for the study of chemical reactions in laser-induced plasmas. Resonance fluorescence excitation of diatomic aluminum monoxide (AlO) and triatomic dialuminum monoxide (Al 2 O) was used to identify these chemical intermediates. Time-resolved fluorescence spectra of AlO and Al 2 O were used to observe the temporal evolution in laser-induced Al plasmas and to study their formation in the Al-O 2 chemistry in air.

Development of Laser-Induced Fluorescence Diagnostic for the Paul Trap Simulator Experiment

CERN Document Server

Chung, Moses; Efthimion, Philip; Gilson, Erik P; Majeski, Richard; Startsev, Edward

2005-01-01

The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. For the in-situ measurement of the transverse ion density profile in the PTSX device, which is essential for the study of beam mismatch and halo particle production, a laser-induced fluorescence diagnostic system is being developed. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. The installation of the barium ion source and the characterization of the tunable dye laser system are discussed. The design of the collection optics with an intensified CCD camera system is also discussed. Finally, initial test results using the laser-induced fluorescence diagnostic will be presented.

Time-synchronized continuous wave laser-induced fluorescence on an oscillatory xenon discharge

Energy Technology Data Exchange (ETDEWEB)

MacDonald, N. A.; Cappelli, M. A. [Stanford Plasma Physics Laboratory, Stanford University, Stanford, California 94305 (United States); Hargus, W. A. Jr. [Air Force Research Laboratory, Edwards AFB, California 93524 (United States)

2012-11-15

A novel approach to time-synchronizing laser-induced fluorescence measurements to an oscillating current in a 60 Hz xenon discharge lamp using a continuous wave laser is presented. A sample-hold circuit is implemented to separate out signals at different phases along a current cycle, and is followed by a lock-in amplifier to pull out the resulting time-synchronized fluorescence trace from the large background signal. The time evolution of lower state population is derived from the changes in intensity of the fluorescence excitation line shape resulting from laser-induced fluorescence measurements of the 6s{sup Prime }[1/2]{sub 1}{sup 0}-6p{sup Prime }[3/2]{sub 2} xenon atomic transition at {lambda}= 834.68 nm. Results show that the lower state population oscillates at twice the frequency of the discharge current, 120 Hz.

The Antinociceptive Effects of Hydroalcoholic Extract of Borago Officinalis Flower in Male Rats Using Formalin Test.

Science.gov (United States)

Shahraki, Mohammad Reza; Ahmadimoghadm, Mahdieh; Shahraki, Ahmad Reza

2015-10-01

Borago officinalis flower (borage) is a known sedative in herbal medicine; the aim of the present study was to evaluate the antinociceptive effect of borage hydroalcoholic extract in formalin test male rats. Fifty-six adult male albino Wistar rats were randomly divided into seven groups: Control groups of A (intact), B (saline), and C (Positive control) plus test groups of D, E, F, and G (n=8). The groups D, E, and F received 6.25, 12.5, and 25 mg/kg, Borago officinalis flower hydroalcholic extract before the test, respectively but group G received 25 mg/kg borage extract and aspirin before the test. A biphasic pain was induced by injection of formalin 1%. The obtained data were analyzed by SPSS software ver. 17 employing statistical tests of Kruskal-Wallis and Mann-Whitney. The results were expressed as mean±SD. Statistical differences were considered significant at Ptest groups of D, E, F, and G significantly decreased compared to groups A and B, but this score did not show any difference compared to group C. Moreover, chronic pain behavior score in group G was significantly lower than all other groups. The results indicated that Borago officinalis hydroalcoholic extract affects the acute and chronic pain behavior response in formaline test male rats.

Fixing Formalin: A Method to Recover Genomic-Scale DNA Sequence Data from Formalin-Fixed Museum Specimens Using High-Throughput Sequencing.

Directory of Open Access Journals (Sweden)

Sarah M Hykin

Full Text Available For 150 years or more, specimens were routinely collected and deposited in natural history collections without preserving fresh tissue samples for genetic analysis. In the case of most herpetological specimens (i.e. amphibians and reptiles, attempts to extract and sequence DNA from formalin-fixed, ethanol-preserved specimens-particularly for use in phylogenetic analyses-has been laborious and largely ineffective due to the highly fragmented nature of the DNA. As a result, tens of thousands of specimens in herpetological collections have not been available for sequence-based phylogenetic studies. Massively parallel High-Throughput Sequencing methods and the associated bioinformatics, however, are particularly suited to recovering meaningful genetic markers from severely degraded/fragmented DNA sequences such as DNA damaged by formalin-fixation. In this study, we compared previously published DNA extraction methods on three tissue types subsampled from formalin-fixed specimens of Anolis carolinensis, followed by sequencing. Sufficient quality DNA was recovered from liver tissue, making this technique minimally destructive to museum specimens. Sequencing was only successful for the more recently collected specimen (collected ~30 ybp. We suspect this could be due either to the conditions of preservation and/or the amount of tissue used for extraction purposes. For the successfully sequenced sample, we found a high rate of base misincorporation. After rigorous trimming, we successfully mapped 27.93% of the cleaned reads to the reference genome, were able to reconstruct the complete mitochondrial genome, and recovered an accurate phylogenetic placement for our specimen. We conclude that the amount of DNA available, which can vary depending on specimen age and preservation conditions, will determine if sequencing will be successful. The technique described here will greatly improve the value of museum collections by making many formalin-fixed specimens

Fixing Formalin: A Method to Recover Genomic-Scale DNA Sequence Data from Formalin-Fixed Museum Specimens Using High-Throughput Sequencing.

Science.gov (United States)

Hykin, Sarah M; Bi, Ke; McGuire, Jimmy A

2015-01-01

For 150 years or more, specimens were routinely collected and deposited in natural history collections without preserving fresh tissue samples for genetic analysis. In the case of most herpetological specimens (i.e. amphibians and reptiles), attempts to extract and sequence DNA from formalin-fixed, ethanol-preserved specimens-particularly for use in phylogenetic analyses-has been laborious and largely ineffective due to the highly fragmented nature of the DNA. As a result, tens of thousands of specimens in herpetological collections have not been available for sequence-based phylogenetic studies. Massively parallel High-Throughput Sequencing methods and the associated bioinformatics, however, are particularly suited to recovering meaningful genetic markers from severely degraded/fragmented DNA sequences such as DNA damaged by formalin-fixation. In this study, we compared previously published DNA extraction methods on three tissue types subsampled from formalin-fixed specimens of Anolis carolinensis, followed by sequencing. Sufficient quality DNA was recovered from liver tissue, making this technique minimally destructive to museum specimens. Sequencing was only successful for the more recently collected specimen (collected ~30 ybp). We suspect this could be due either to the conditions of preservation and/or the amount of tissue used for extraction purposes. For the successfully sequenced sample, we found a high rate of base misincorporation. After rigorous trimming, we successfully mapped 27.93% of the cleaned reads to the reference genome, were able to reconstruct the complete mitochondrial genome, and recovered an accurate phylogenetic placement for our specimen. We conclude that the amount of DNA available, which can vary depending on specimen age and preservation conditions, will determine if sequencing will be successful. The technique described here will greatly improve the value of museum collections by making many formalin-fixed specimens available for

Sensitive detection and separation of fluorescent derivatives using capillary electrophoresis with laser-induced fluorescence detection with 532nm Nd:YAG laser

International Nuclear Information System (INIS)

Vrabel, Patrik; Taborsky, Petr; Ryvolova, Marketa; Havel, Josef; Preisler, Jan

2006-01-01

Capillary electrophoresis with laser-induced fluorescence detection (CELIF) is a powerful tool for separation and sensitive determination of fluorescent species. Biologically active compounds, such as amino acids, peptides and proteins may exhibit native fluorescence, which is however often low and/or an expensive laser is required for excitation in UV. Therefore, labelling of the analytes with a fluorescent dye is usually necessary. In this work, a home-built CELIF instrument with diode pumped frequency-doubled continuous wave Nd:YAG excitation laser with feedback power regulation (532nm) was constructed. The suitability of this type of laser for LIF detection in a separation method was found excellent. A limit of detection (LOD) (S/N=3) of 2x10 -13 mol/l was achieved with rhodamine B, which is comparable to those obtained using similar instruments with Ar + laser [Y.F. Cheng, N.J. Dovichi, Science 242 (1988) 562, E.S. Yeung et al., J. Chromatogr. 608 (1992) 73]. LOD of a protein derivatized according to modified procedures [M.J. Little et al., Anal. Chim. Acta 339 (1997) 279, A. Chersi et al., Biochim. Biophys. Acta 1336 (1997) 83] was determined. Detection of the derivatives was found to be limited by insufficient reaction recovery at low analyte concentration, chemical noise, separation efficiency and quality of the derivatizing reagent rather than by the detector performance. As a consequence, a huge gap between the detection ability of CELIF instruments and LOD determined in real samples is revealed

Fluorescence and Four-Wave Mixing in Electromagnetically Induced Transparency Windows

International Nuclear Information System (INIS)

Wang Zhi-Guo; Li Cheng; Zhang Zhao-Yang; Che Jun-Ling; Qin Meng-Zhe; He Jia-Nan; Zhang Yan-Peng

2013-01-01

We simultaneously compare the probe transmission, Four-Wave Mixing (FWM) and fluorescence signals with dressing effects in a four-level atomic system. The variation rules of three types of signals are exhibited by changing the frequency detuning and power of incident laser beams. The interplay between two ladder subsystems is investigated in the Y-type atomic system. In particular, the fluorescence signal with ultra-narrow linewidth is obtained due to being sheared twice by the electromagnetically induced transparency window. Such fluorescence with very high coherence and monochromaticity can be used for the quantum correlation and narrow linewidth laser

Fluorescent nanodiamond tracking reveals intraneuronal transport abnormalities induced by brain-disease-related genetic risk factors

Science.gov (United States)

Haziza, Simon; Mohan, Nitin; Loe-Mie, Yann; Lepagnol-Bestel, Aude-Marie; Massou, Sophie; Adam, Marie-Pierre; Le, Xuan Loc; Viard, Julia; Plancon, Christine; Daudin, Rachel; Koebel, Pascale; Dorard, Emilie; Rose, Christiane; Hsieh, Feng-Jen; Wu, Chih-Che; Potier, Brigitte; Herault, Yann; Sala, Carlo; Corvin, Aiden; Allinquant, Bernadette; Chang, Huan-Cheng; Treussart, François; Simonneau, Michel

2017-05-01

Brain diseases such as autism and Alzheimer's disease (each inflicting >1% of the world population) involve a large network of genes displaying subtle changes in their expression. Abnormalities in intraneuronal transport have been linked to genetic risk factors found in patients, suggesting the relevance of measuring this key biological process. However, current techniques are not sensitive enough to detect minor abnormalities. Here we report a sensitive method to measure the changes in intraneuronal transport induced by brain-disease-related genetic risk factors using fluorescent nanodiamonds (FNDs). We show that the high brightness, photostability and absence of cytotoxicity allow FNDs to be tracked inside the branches of dissociated neurons with a spatial resolution of 12 nm and a temporal resolution of 50 ms. As proof of principle, we applied the FND tracking assay on two transgenic mouse lines that mimic the slight changes in protein concentration (∼30%) found in the brains of patients. In both cases, we show that the FND assay is sufficiently sensitive to detect these changes.

Studi Identifikasi Kandungan Formalin pada Ikan Pindang di Pasar Tradisional dan Modern Kota Semarang

OpenAIRE

Sitiopan Telaumbanua, Henny Putri

2012-01-01

Ikan pindang adalah salah satu jenis makanan olahan yang dikonsumsi masyarakat dan harus segera dijual karena daya tahan yang terbatas dan akan cepat membusuk. Penggunaan formalin sebagai pengawet ternyata telah disalahgunakan oleh pihak-pihak yang tidak bertanggungjawab, dengan cara menggunakan formalin tersebut sebagai bahan pengawet dalam industri makanan. Penelitian ini bertujuan untuk mengidentifikasi kandungan formalin pada ikan pindang yang dijual di pasar tradisional dan modern Kota S...

Synergistic effect of the interaction between curcumin and diclofenac on the formalin test in rats.

Science.gov (United States)

De Paz-Campos, Marco A; Ortiz, Mario I; Chávez Piña, Aracely E; Zazueta-Beltrán, Liliana; Castañeda-Hernández, Gilberto

2014-10-15

The association of non-steroidal anti-inflammatory drugs with certain plant extracts can increase antinociceptive activity, permitting the use of lower doses and thus limiting side effects. Therefore, the aim objective of the current study was to examine the effects of curcumin on the nociception and pharmacokinetics of diclofenac in rats. Antinociception was assessed using the formalin test. Diluted formalin was injected subcutaneously into the dorsal surface of the right hind paw. Nociceptive behavior was quantified as the number of flinches of the injected paw during 60 min after injection, and a reduction in formalin-induced flinching was interpreted as an antinociceptive response. Rats were treated with oral diclofenac (1-31 mg/kg), curcumin (3.1-100 mg/kg) or the diclofenac-curcumin combination (2.4-38.4 mg/kg). To determine the possibility of a pharmacokinetic interaction, the oral bioavailability of diclofenac (10 mg/kg) was studied in presence and the absence of curcumin (31 mg/kg). Diclofenac, curcumin, or diclofenac-curcumin combination produced an antinociceptive effect on the formalin test. ED30 values were estimated for the individual drugs, and an isobologram was constructed. The derived theoretical ED30 for the antinociceptive effect (19.2 mg/kg) was significantly different from the observed experimental ED30 value (9.8 mg/kg); hence, the interaction between diclofenac and curcumin that mediates the antinociceptive effect was synergistic. Notwithstanding, the interaction does not appear to involve pharmacokinetic mechanisms, as oral curcumin failed to produce any significant alteration in oral diclofenac bioavailability. Data suggest that the diclofenac-curcumin combination can interact at the systemic level and may have therapeutic advantages for the clinical treatment of inflammatory pain. Copyright © 2014 Elsevier GmbH. All rights reserved.

Visualization of Two-Phase Fluid Distribution Using Laser Induced Exciplex Fluorescence

Science.gov (United States)

Kim, J. U.; Darrow, J.; Schock, H.; Golding, B.; Nocera, D.; Keller, P.

1998-03-01

Laser-induced exciplex (excited state complex) fluorescence has been used to generate two-dimensional images of dispersed liquid and vapor phases with spectrally resolved two-color emissions. In this method, the vapor phase is tagged by the monomer fluorescence while the liquid phase is tracked by the exciplex fluorescence. A new exciplex visualization system consisting of DMA and 1,4,6-TMN in an isooctane solvent was developed.(J.U. Kim et al., Chem. Phys. Lett. 267, 323-328 (1997)) The direct ca

Application of fluorescent in situ hybridisation for demonstration of Coxiella burnetti in placentas from ruminant abortions

DEFF Research Database (Denmark)

Jensen, Tim Kåre; Montgomery, Donald L.; Jaeger, Paula T.

2007-01-01

A fluorescent in situ hybridisation (FISH) assay targeting 16S ribosomal RNA was developed for detection of the zoonotic bacterium Coxiella burnetii in formalin-fixed, paraffin-embedded tissue, and applied on placentas from ruminant abortions. The applicability of the FISH assay was compared...

Quantitative laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine

NARCIS (Netherlands)

Verbiezen, K.; Klein-Douwel, R. J. H.; van Viet, A. P.; Donkerbroek, A. J.; Meerts, W. L.; Dam, N. J.; ter Meulen, J. J.

2007-01-01

We present quantitative, in-cylinder, UV-laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine. Processing of the raw fluorescence signals includes a detailed correction, based on additional measurements, for the effect of laser beam and fluorescence attenuation, and

Perbedaan Kadar Formalin pada Tahu yang Dijual di Pasar Pusat Kota dengan Pinggiran Kota Padang

Directory of Open Access Journals (Sweden)

Siti Ardina Sari

2014-09-01

Full Text Available AbstrakTahu merupakan makanan yang digemari oleh masyarakat.Tahu mempunyai daya tahan sekitar 1 - 2 hari sehingga pedagang sering menambahkan formalin sebagai pengawet. Formalin merupakan bahan pengawet yang dilarang oleh pemerintah yang penggunaannya masih terdapat secara luas di masyarakat dan bila dilihat dari tekstur tahu yang dijual di pasar kota Padang, dicurigai tahu memiliki kandungan formalin.Tujuan penelitian ini adalah untuk mengetahui perbedaan kadar formalin pada tahu yang dijual di pasar pusat kota dengan pinggiran kota Padang. Penelitian ini dilakukan di laboratorium Balai Riset dan Standardisasi Industri Padang.Jenis penelitian ini adalah analitik yang telah dilaksanakan pada bulan Juni-September 2013. Jumlah sampel adalah sebanyak 36 buah yang terdiri dari 18 sampel tahu yang berasal dari pasar pusat kota dan 18 sampel tahu yang berasal dari pasar pinggiran kota Padang. Uji kualitatif formalin pada tahu dilakukan dengan metode asam kromatropat dan uji kuantitatif formalin menggunakan metode titrasi asam basa. Analisis data dilakukan secara bivariat dengan menggunakan uji t. Hasil penelitian didapatkan kadar formalin pada tahu di pasar pusat kota Padang dari 18 sampel yang diperiksa terdapat 17 sampel yang positif formalin dengan kadar paling tinggi adalah 3.65%. Kadar formalin pada tahu di pasar pinggiran kota Padang dari 18 sampel yang diperiksa terdapat 17 sampel yang positif formalin dengan kadar paling tinggi adalah 2.73%. Rata-rata kadar formalin pada pasar pusat kota adalah 1.08% dan pasar pinggiran kota adalah 0.67%.Kata Kunci: kadar formalin, tahu, pasar pusat kota Padang, pasar pinggiran kota PadangAbstractTofu is a favorite food among the community. Tofu has resistance 1 - 2 days so that merchant often add formalin as a preservative. Formalin is a preservative which is banned by the government that there is still widespread use in the community and the texture of tofu sold in the market is suspected for having

Kr II laser-induced fluorescence for measuring plasma acceleration.

Science.gov (United States)

Hargus, W A; Azarnia, G M; Nakles, M R

2012-10-01

We present the application of laser-induced fluorescence of singly ionized krypton as a diagnostic technique for quantifying the electrostatic acceleration within the discharge of a laboratory cross-field plasma accelerator also known as a Hall effect thruster, which has heritage as spacecraft propulsion. The 728.98 nm Kr II transition from the metastable 5d(4)D(7/2) to the 5p(4)P(5/2)(∘) state was used for the measurement of laser-induced fluorescence within the plasma discharge. From these measurements, it is possible to measure velocity as krypton ions are accelerated from near rest to approximately 21 km/s (190 eV). Ion temperature and the ion velocity distributions may also be extracted from the fluorescence data since available hyperfine splitting data allow for the Kr II 5d(4)D(7/2)-5p(4)P(5/2)(∘) transition lineshape to be modeled. From the analysis, the fluorescence lineshape appears to be a reasonable estimate for the relatively broad ion velocity distributions. However, due to an apparent overlap of the ion creation and acceleration regions within the discharge, the distributed velocity distributions increase ion temperature determination uncertainty significantly. Using the most probable ion velocity as a representative, or characteristic, measure of the ion acceleration, overall propellant energy deposition, and effective electric fields may be calculated. With this diagnostic technique, it is possible to nonintrusively characterize the ion acceleration both within the discharge and in the plume.

A modification of a previous model fo r inflammatory tooth pain: Effects of different capsaicin and formalin concentrations and ibuprofen

Directory of Open Access Journals (Sweden)

Maryam Raoof DDS, MS

2012-09-01

Full Text Available BACKGROUND AND AIM:This study aimed to solve the problems faced with the previous model of inflammatory tooth painin rats.METHODS:After cutting 2 mm of the distal extremities, the polyethylene crownswere placed on the mandibularincisors. In contrast to the original model, we used flow composite instead of wire in order to maximize the retention ofcrowns. Different concentrations of capsaicin (10, 25 and 100 mg/ml and formalin were administrated into the cavitiesunder the crowns. The algesic agent-induced behaviors were evaluated.RESULTS:The modified model had no liquid leakage. Furthermore, composite allowed the crowns to remain for alonger period of time. Capsaicin 25, 100 mg/ml and formalin applications induced significantly more painfulstimulation compared with control groups (P < 0.001. These responses were significantly reduced by theadministration of ibuprofen, 20 minutes prior to the capsaicin 100 mg/ml injection.CONCLUSIONS:This model seems to be adequate for long-term pain related experiments in which fluid leakageelimination is important.

[Laser induced fluorescence spectrum characteristics of common edible oil and fried cooking oil].

Science.gov (United States)

Mu, Tao-tao; Chen, Si-ying; Zhang, Yin-chao; Chen, He; Guo, Pan; Ge, Xian-ying; Gao, Li-lei

2013-09-01

In order to detect the trench oil the authors built a trench oil rapid detection system based on laser induced fluorescence detection technology. This system used 355 nm laser as excitation light source. The authors collected the fluorescence spectrum of a variety of edible oil and fried cooking oil (a kind of trench oil) and then set up a fluorescence spectrum database by taking advantage of the trench oil detection system It was found that the fluorescence characteristics of fried cooking oil and common edible oil were obviously different. Then it could easily realize the oil recognition and trench oil rapid detection by using principal component analysis and BP neural network, and the overall recognition rate could reach as high as 97.5%. Experiments showed that laser induced fluorescence spectrum technology was fast, non-contact, and highly sensitive. Combined with BP neural network, it would become a new technique to detect the trench oil.

Simultaneous detection of ultraviolet B-induced DNA damage using capillary electrophoresis with laser-induced fluorescence

Energy Technology Data Exchange (ETDEWEB)

Guthrie, Jeffrey W., E-mail: jeff.guthrie@emich.edu; Limmer, Robert T.; Brooks, Eric A.; Wisnewski, Chelsea C.; Loggins-Davis, Nnekia D.; Bouzid, Abderraouf

2015-01-01

Highlights: • CE–LIF was developed for simultaneous detection of UV-induced DNA photoproducts. • Fluorescent quantum dot reporters enabled detection of small amounts of photoproducts. • Photoproducts were detected after 65 J m{sup −2} of fluence from a UVB lamp in ∼6 ng of DNA. • Natural sunlight induced cyclobutane pyrimidine dimers after only 15 min of exposure. - Abstract: An immunoassay based on CE–LIF was developed for the simultaneous detection of cyclobutane pyrimidine dimers (CPDs) and pyrimidine 6-4 pyrimidone photoproducts (6-4PPs) in genomic DNA irradiated with UVB or natural sunlight. Human cells were first exposed to varying amounts of UVB or natural sunlight to induce DNA damage. Genomic DNA was extracted and incubated with anti-CPD and anti-6-4PP primary antibodies attached to secondary antibodies with a fluorescent quantum dot (QD) reporter that emitted either red or yellow fluorescence. CE was used to separate the unbound antibodies from those bound to the photoproducts, and LIF with appropriate optical filters was used to separate the fluorescence signals from each QD to individual photomultiplier tubes for simultaneous photoproduct detection. Using this strategy, photoproducts were detected from ∼6 ng (200 ng μL{sup −1}) of DNA under a low UVB fluence of 65 J m{sup −2} for CPDs or 195 J m{sup −2} for 6-4PPs. This assay was also the first to demonstrate the detection of CPDs in human cells after only 15 min of irradiation under natural sunlight.

Simultaneous detection of ultraviolet B-induced DNA damage using capillary electrophoresis with laser-induced fluorescence

International Nuclear Information System (INIS)

Guthrie, Jeffrey W.; Limmer, Robert T.; Brooks, Eric A.; Wisnewski, Chelsea C.; Loggins-Davis, Nnekia D.; Bouzid, Abderraouf

2015-01-01

Highlights: • CE–LIF was developed for simultaneous detection of UV-induced DNA photoproducts. • Fluorescent quantum dot reporters enabled detection of small amounts of photoproducts. • Photoproducts were detected after 65 J m −2 of fluence from a UVB lamp in ∼6 ng of DNA. • Natural sunlight induced cyclobutane pyrimidine dimers after only 15 min of exposure. - Abstract: An immunoassay based on CE–LIF was developed for the simultaneous detection of cyclobutane pyrimidine dimers (CPDs) and pyrimidine 6-4 pyrimidone photoproducts (6-4PPs) in genomic DNA irradiated with UVB or natural sunlight. Human cells were first exposed to varying amounts of UVB or natural sunlight to induce DNA damage. Genomic DNA was extracted and incubated with anti-CPD and anti-6-4PP primary antibodies attached to secondary antibodies with a fluorescent quantum dot (QD) reporter that emitted either red or yellow fluorescence. CE was used to separate the unbound antibodies from those bound to the photoproducts, and LIF with appropriate optical filters was used to separate the fluorescence signals from each QD to individual photomultiplier tubes for simultaneous photoproduct detection. Using this strategy, photoproducts were detected from ∼6 ng (200 ng μL −1 ) of DNA under a low UVB fluence of 65 J m −2 for CPDs or 195 J m −2 for 6-4PPs. This assay was also the first to demonstrate the detection of CPDs in human cells after only 15 min of irradiation under natural sunlight

Thiel embalming fluid--a new way to revive formalin-fixed cadaveric specimens.

Science.gov (United States)

Hunter, Amanda; Eisma, Roos; Lamb, Clare

2014-09-01

By soft fixing cadavers using the Thiel embalming method, our cadavers now exhibit a greater degree of flexibility and color retention compared to that of traditional formalin-fixed cadavers. The aim of this experiment was to discover whether Thiel embalming fluid could be used to revive and soften the muscles of formalin-fixed prosected specimens. Earlier this year, two severely dehydrated formalin-fixed forearm and hand specimens were fully submerged in a tank containing Thiel embalming fluid. After a period of six months the specimens were removed from the tank and noticeable changes were observed in flexibility, quality of the tissue, and color of the specimens. © 2014 Wiley Periodicals, Inc.

Single-cell Raman and fluorescence microscopy reveal the association of lipid bodies with phagosomes in leukocytes

Science.gov (United States)

van Manen, Henk-Jan; Kraan, Yvonne M.; Roos, Dirk; Otto, Cees

2005-01-01

Cellular imaging techniques based on vibrational spectroscopy have become powerful tools in cell biology because the molecular composition of subcellular compartments can be visualized without the need for labeling. Using high-resolution, nonresonant confocal Raman microscopy on individual cells, we demonstrate here that lipid bodies (LBs) rich in arachidonate as revealed by their Raman spectra associate with latex bead-containing phagosomes in neutrophilic granulocytes. This finding was corroborated in macrophages and in PLB-985 cells, which can be induced to differentiate into neutrophil-like cells, by selective staining of LBs and visualization by confocal fluorescence microscopy. We further show that the accumulation of LBs near phagosomes is mediated at least in part by the flavohemoprotein gp91phox (in which “phox” is phagocyte oxidase), because different LB distributions around phagocytosed latex beads were observed in WT and gp91phox-deficient PLB-985 cells. gp91phox, which accumulates in the phagosomal membrane, is the catalytic subunit of the leukocyte NADPH oxidase, a critical enzyme in the innate immune response. Finally, time-lapse fluorescence microscopy experiments on neutrophils revealed that the LB-phagosome association is transient, similar to the “kiss-and-run” behavior displayed by endosomes involved in phagosome maturation. Because arachidonic acid (AA) has been shown to be involved in NADPH oxidase activation and phagosome maturation in neutrophils and macrophages, respectively, the findings reported here suggest that LBs may provide a reservoir of AA for local activation of these essential leukocyte functions. PMID:16002471

Development of laser-induced fluorescence detection to assay DNA damage

International Nuclear Information System (INIS)

Sharma, M.; Freund, H.G.

1991-01-01

A precolumn derivation method has been developed for high performance liquid chromatographic (HPLC) analysis of DNA damage using fluorescence detection. The modified nucleotide, having excised enzymatically from the exposed DNA, is enriched from the normal nucleotides and labeled with a fluorescent reagent. The labeling procedure involves phosphoramidation of the nucleotide with ethylenediamine (EDA) followed by conjugation of the free amino end of the phosphoramidate with 5-dimethylaminonaphthalene 1-sulfonyl chloride, commonly known as Dansyl chloride. The dansylated nucleotide can be analyzed with a sub-picomole limit of detection (LOD) by conventional HPLC using a conventional fluorescence detector. By combining microbore HPLC with laser-induced fluorescence (LIF) detection, the authors present the development of an analytical system that has sub-femtomole LOD for real-time analysis of the dansylated nucleotide. In this paper the application of the developed system in fluorescence postlabeling assay of a small alkyl-modified nucleotide (5-methyl CMP) in calf-thymus DNA is discussed

Intravesical instillation of Formalin for hemorrhagic cystitis secondary to radiation for gynecologic malignancies

International Nuclear Information System (INIS)

Behnam, K.; Patil, U.B.; Mariano, E.

1983-01-01

Our experience with the use of Formalin instillation in intractable gross hematuria secondary to radiation cystitis in patients with gynecological malignancies is reported. This study indicates coagulative effect of low concentration of Formalin with minimal side effects as a method to control hemorrhage

Phase-contrast X-ray computed tomography of non-formalin fixed biological objects

Energy Technology Data Exchange (ETDEWEB)

Takeda, Tohoru E-mail: ttakeda@md.tsukuba.ac.jp; Momose, Atsushi; Wu, Jin; Zeniya, Tsutomu; Yu Quanwen; Thet Thet Lwin; Itai, Yuji

2001-07-21

Using a monolithic X-ray interferometer having the view size of 25 mmx25 mm, phase-contrast X-ray CT (PCCT) was performed for non-formalin fixed livers of two normal rats and a rabbit transplanted with VX-2 cancer. PCCT images of liver and cancer lesions resembled well those obtained by formalin fixed samples.

In vivo study of the human skin by the method of laser-induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Borisova, E.; Avramov, L.

2000-01-01

The goals of this study are to perform a preliminary evaluation of the diagnostic potential of noninvasive laser-induced auto-fluorescence spectroscopy (LIAFS) for human skin and optimize of detection and diagnosis of hollow organs and skin. In recent years, there has been growing interest in the use of laser-induced fluorescence to discriminate disease from normal surrounding tissue. The most fluorescence studies have used exogenous fluorophores of this discrimination. The laser-induced auto-fluorescence which is used for diagnosis of tissues in the human body avoids administration of any drugs. In this study a technique for optical biopsy of in vivo human skin is presented. The auto-fluorescence characterization of tissue relies on different spectral properties of tissues. It was demonstrated a differentiation between normal skin and skin with vitiligo. Two main endogenous fluorophores in the human skin account for most of the cellular auto-fluorescence for excitation wavelength 337 nm reduced from of nicotinamide adenine dinucleotide and collagen. The auto-fluorescence spectrum of human skin depend on main internal absorbers which are blood and melanin. In this study was described the effect caused by blood and melanin content on the shape of the auto-fluorescence spectrum of human skin. Human skin fluorescence spectrum might provide dermatologists with important information and such investigations are successfully used now in skin disease diagnostics, in investigation of the environmental factor impact or for evaluation of treatment efficiency. (authors)

Laser-Induced Fluorescence Measurements within a Laboratory Hall Thruster (Postprint)

National Research Council Canada - National Science Library

Hargus, Jr., W. A; Cappelli, M. A

1999-01-01

In this paper, we describe the results of a study of laser induced fluorescence velocimetry of ionic xenon in the plume and interior acceleration channel of a laboratory Hall type thruster operating...

Fluorescence in situ hybridization on formalin-fixed and paraffin-embedded tissue

DEFF Research Database (Denmark)

Laub Petersen, Bodil; Zeuthen, Mette Christa; Pedersen, Sanni

2004-01-01

Fluorescence in situ hybridization (FISH) is widely used to study numerical and structural genetic abnormalities in both metaphase and interphase cells. The technique is based on the hybridization of labeled probes to complementary sequences in the DNA or RNA of the cells. Interphase FISH is most...... in time lapse between removal of tissue and fixation, duration of fixation, enzymatic pretreatment, hybridization conditions, and posthybridization washing conditions are important factors in the hybridization. In this study, we have listed the results of a systematic approach to improve FISH on isolated...

Phase-contrast X-ray computed tomography of non-formalin fixed biological objects

Science.gov (United States)

Takeda, Tohoru; Momose, Atsushi; Wu, Jin; Zeniya, Tsutomu; Yu, Quanwen; Thet-Thet-Lwin; Itai, Yuji

2001-07-01

Using a monolithic X-ray interferometer having the view size of 25 mm×25 mm, phase-contrast X-ray CT (PCCT) was performed for non-formalin fixed livers of two normal rats and a rabbit transplanted with VX-2 cancer. PCCT images of liver and cancer lesions resembled well those obtained by formalin fixed samples.

Optimization of Single- and Dual-Color Immunofluorescence Protocols for Formalin-Fixed, Paraffin-Embedded Archival Tissues.

Science.gov (United States)

Kajimura, Junko; Ito, Reiko; Manley, Nancy R; Hale, Laura P

2016-02-01

Performance of immunofluorescence staining on archival formalin-fixed paraffin-embedded human tissues is generally not considered to be feasible, primarily due to problems with tissue quality and autofluorescence. We report the development and application of procedures that allowed for the study of a unique archive of thymus tissues derived from autopsies of individuals exposed to atomic bomb radiation in Hiroshima, Japan in 1945. Multiple independent treatments were used to minimize autofluorescence and maximize fluorescent antibody signals. Treatments with NH3/EtOH and Sudan Black B were particularly useful in decreasing autofluorescent moieties present in the tissue. Deconvolution microscopy was used to further enhance the signal-to-noise ratios. Together, these techniques provide high-quality single- and dual-color fluorescent images with low background and high contrast from paraffin blocks of thymus tissue that were prepared up to 60 years ago. The resulting high-quality images allow the application of a variety of image analyses to thymus tissues that previously were not accessible. Whereas the procedures presented remain to be tested for other tissue types and archival conditions, the approach described may facilitate greater utilization of older paraffin block archives for modern immunofluorescence studies. © 2016 The Histochemical Society.

A new substitute for formalin: Application to embalming cadavers.

Science.gov (United States)

Haizuka, Yoshinori; Nagase, Miki; Takashino, Satoshi; Kobayashi, Yasushi; Fujikura, Yoshihisa; Matsumura, George

2018-01-01

The development of formalin-free fixatives is an urgent issue in gross anatomy because of the health hazard and the tissue-hardening actions of formalin. We recently identified the fixative, antimicrobial, and preservative effects of N-vinyl-2-pyrrolidone (NVP), a precursor of the water-soluble macromolecular polymer polyvinylpyrrolidone, in animal experiments. The aim of the present study is to investigate whether NVP solution can be used as an alternative to formalin in human cadaveric dissection. Twelve donated cadavers were infused with NVP via the femoral and common carotid arteries using a peristaltic pump. Experienced teaching staff members in our department dissected the cadavers and examined their macroanatomical properties. The NVP-embalmed corpses showed no sign of decomposition or fungal growth. The bodies remained soft and flexible. Notably, the shoulder, elbow, wrist, phalangeal, hip, knee, cervical spine, and temporomandibular joints were highly mobile, almost equivalent to those of living individuals. The range of motion of most joints was greater in the NVP-fixed than formalin-fixed cadavers. Under the dermis, the subcutaneous fat was markedly reduced and the connective tissues were transparent, so the ligaments, cutaneous nerves, and veins were easily discernible. The abdominal wall and the visceral organs remained pliable and elastic, resembling those of fresh cadavers. The lungs, liver, and gastrointestinal tract were moveable in the thoracic and abdominal cavities and were readily isolated. NVP can be used successfully as a fixative and preservative solution for human cadavers; furthermore, NVP-embalmed bodies could be valuable for learning clinical skills and for training, and for developing innovative medical devices. Clin. Anat. 31:90-98, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Instantaneous temperature field measurements using planar laser-induced fluorescence.

Science.gov (United States)

Seitzman, J M; Kychakoff, G; Hanson, R K

1985-09-01

A single-pulse, laser-induced-fluorescence diagnostic for the measurement of two-dimensional temperature fields in combustion flows is described. The method uses sheet illumination from a tunable laser to excite planar laserinduced fluorescence in a stable tracer molecule, seeded at constant mole fraction into the flow field. The temporal resolution of this technique is determined by the laser pulse length. Experimental results are presented for a rodstabilized, premixed methane-air flame, using the Q(1) (22) line of the nitric oxide A(2) Sigma(+) (v = 0) ? X(2)II((1/2))(v = 0) transition (lambda approximately 225.6 nm).

In-vivo optical detection of cancer using chlorin e6 – polyvinylpyrrolidone induced fluorescence imaging and spectroscopy

International Nuclear Information System (INIS)

Chin, William WL; Thong, Patricia SP; Bhuvaneswari, Ramaswamy; Soo, Khee Chee; Heng, Paul WS; Olivo, Malini

2009-01-01

Photosensitizer based fluorescence imaging and spectroscopy is fast becoming a promising approach for cancer detection. The purpose of this study was to examine the use of the photosensitizer chlorin e6 (Ce6) formulated in polyvinylpyrrolidone (PVP) as a potential exogenous fluorophore for fluorescence imaging and spectroscopic detection of human cancer tissue xenografted in preclinical models as well as in a patient. Fluorescence imaging was performed on MGH human bladder tumor xenografted on both the chick chorioallantoic membrane (CAM) and the murine model using a fluorescence endoscopy imaging system. In addition, fiber optic based fluorescence spectroscopy was performed on tumors and various normal organs in the same mice to validate the macroscopic images. In one patient, fluorescence imaging was performed on angiosarcoma lesions and normal skin in conjunction with fluorescence spectroscopy to validate Ce6-PVP induced fluorescence visual assessment of the lesions. Margins of tumor xenografts in the CAM model were clearly outlined under fluorescence imaging. Ce6-PVP-induced fluorescence imaging yielded a specificity of 83% on the CAM model. In mice, fluorescence intensity of Ce6-PVP was higher in bladder tumor compared to adjacent muscle and normal bladder. Clinical results confirmed that fluorescence imaging clearly captured the fluorescence of Ce6-PVP in angiosarcoma lesions and good correlation was found between fluorescence imaging and spectral measurement in the patient. Combination of Ce6-PVP induced fluorescence imaging and spectroscopy could allow for optical detection and discrimination between cancer and the surrounding normal tissues. Ce6-PVP seems to be a promising fluorophore for fluorescence diagnosis of cancer

Laser induced fluorescence technique for detecting organic matter in East China Sea

Science.gov (United States)

Chen, Peng; Wang, Tianyu; Pan, Delu; Huang, Haiqing

2017-10-01

A laser induced fluorescence (LIF) technique for fast diagnosing chromophoric dissolved organic matter (CDOM) in water is discussed. We have developed a new field-portable laser fluorometer for rapid fluorescence measurements. In addtion, the fluorescence spectral characteristics of fluorescent constituents (e.g., CDOM, chlorophyll-a) were analyzed with a spectral deconvolution method of bi-Gaussian peak function. In situ measurements by the LIF technique compared well with values measured by conventional spectrophotometer method in laboratory. A significant correlation (R2 = 0.93) was observed between fluorescence by the technique and absorption by laboratory spectrophotometer. Influence of temperature variation on LIF measurement was investigated in lab and a temperature coefficient was deduced for fluorescence correction. Distributions of CDOM fluorescence measured using this technique in the East China Sea coast were presented. The in situ result demonstrated the utility of the LIF technique for rapid detecting dissolved organic matter.

Led induced chlorophyll fluorescence transient imager for measurements of health and stress status of whole plants

NARCIS (Netherlands)

Jalink, H.; Schoor, van der R.

2011-01-01

We have developed LED (light emitting diode) induced fluorescence transient imaging instrumentation to image the plant health/stress status by calculation of two images: Fv/Fm (variable fluorescence over saturation level of fluorescence) and the time response, tTR, of the fluorescence time curve.

Development of laser-induced fluorescence for precombustion diagnostics in spark-ignition engines

Energy Technology Data Exchange (ETDEWEB)

Neij, H.

1998-11-01

Motivated by a desire to understand and optimize combustion in spark-ignition (SI) engines, laser techniques have been developed for measurement of fuel and residual gas, respectively, in the precombustion mixture of an operating SI engine. The primary objective was to obtain two-dimensional, quantitative data in the vicinity of the spark gap at the time of ignition. A laser-induced fluorescence (LIF) technique was developed for fuel visualization in engine environments. Since the fluorescence signal from any commercial gasoline fuel would be unknown to its origin, with an unpredictable dependence on collisional partners, pressure and temperature, a non-fluorescent base fuel - isooctane - was used. For LIF detection, a fluorescent species was added to the fuel. An additive not commonly used in this context - 3-pentanone - was chosen based on its suitable vaporization characteristics and fluorescent properties. The LIF technique was applied to an optically accessible research engine. By calibration, the fluorescence signal from the additive was converted to fuel-to-air equivalence ratio ({phi}). The accuracy and precision of the acquired data were assessed. A statistical evaluation revealed that the spatially averaged equivalence ratio around the spark plug had a significant impact on the combustion event. The strong correlation between these two quantities suggested that the early combustion was sensitive to large-scale inhomogeneities in the precombustion mixture. A similar LIF technique, using acetone as a fluorescent additive in methane, was applied to a combustion cell for ion current evaluation. The local equivalence ratio around the spark gap at the time of ignition was extracted from LIF data. Useful relations were identified between different ion current parameters and the local equivalence ratio, although the impact of the flow field, the fuel type, and the electrode geometry were identified as areas for future research. A novel fuel - dimethyl ether (DME

Chemical Facial Cellulitis Due to Inadvertent Injection of Formalin into Oral Tissue Space.

Science.gov (United States)

Bector, Aditi; Virk, Pawandeep Sandhu; Arakeri, Gururaj

2015-11-05

This paper reports the accidental injection of formalin into oral tissue space, in an 8-year old child resulting in chemical facial necrotizing cellulitis and its management. The common practice of keeping formalin in local anesthesia vials should be avoided by dental clinics, to prevent such unfortunate incidents.

Detection of fecal residue on poultry carcasses by laser induced fluorescence imaging techniques

Science.gov (United States)

The potential use of laser-induced fluorescence imaging techniques was investigated for the detection of diluted fecal matters from various parts of the digestive tract, including colon, ceca, small intestine, and duodenum, on poultry carcasses. One of the challenges for using fluorescence imaging f...

Laser induced fluorescence measurements of the mixing of fuel oil with air

Energy Technology Data Exchange (ETDEWEB)

Arnold, A; Bombach, R; Hubschmid, W; Kaeppeli, B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

We report on measurements of the mixing of fuel oil with air at atmospheric pressure in an industrial premixed gas turbine burner. The concentration of the vaporized fuel oil was measured with laser induced fluorescence. We reason that the fuel oil concentration can be considered with good accuracy as proportional to the fluorescence intensity. (author) 6 fig., 3 refs.

Chemical facial cellulitis due to inadvertent injection of formalin into oral tissue space

Directory of Open Access Journals (Sweden)

Aditi Bector

2015-12-01

Full Text Available This paper reports the accidental injection of formalin into oral tissue space, in an 8-year old child resulting in chemical facial necrotizing cellulitis and its management. The common practice of keeping formalin in local anesthesia vials should be avoided by dental clinics, to prevent such unfortunate incidents.

Elevated pressure improves the extraction and identification of proteins recovered from formalin-fixed, paraffin-embedded tissue surrogates.

Directory of Open Access Journals (Sweden)

Carol B Fowler

2010-12-01

Full Text Available Proteomic studies of formalin-fixed paraffin-embedded (FFPE tissues are frustrated by the inability to extract proteins from archival tissue in a form suitable for analysis by 2-D gel electrophoresis or mass spectrometry. This inability arises from the difficulty of reversing formaldehyde-induced protein adducts and cross-links within FFPE tissues. We previously reported the use of elevated hydrostatic pressure as a method for efficient protein recovery from a hen egg-white lysozyme tissue surrogate, a model system developed to study formalin fixation and histochemical processing.In this study, we demonstrate the utility of elevated hydrostatic pressure as a method for efficient protein recovery from FFPE mouse liver tissue and a complex multi-protein FFPE tissue surrogate comprised of hen egg-white lysozyme, bovine carbonic anhydrase, bovine ribonuclease A, bovine serum albumin, and equine myoglobin (55∶15∶15∶10∶5 wt%. Mass spectrometry of the FFPE tissue surrogates retrieved under elevated pressure showed that both the low and high-abundance proteins were identified with sequence coverage comparable to that of the surrogate mixture prior to formaldehyde treatment. In contrast, non-pressure-extracted tissue surrogate samples yielded few positive and many false peptide identifications. Studies with soluble formalin-treated bovine ribonuclease A demonstrated that pressure modestly inhibited the rate of reversal (hydrolysis of formaldehyde-induced protein cross-links. Dynamic light scattering studies suggest that elevated hydrostatic pressure and heat facilitate the recovery of proteins free of formaldehyde adducts and cross-links by promoting protein unfolding and hydration with a concomitant reduction in the average size of the protein aggregates.These studies demonstrate that elevated hydrostatic pressure treatment is a promising approach for improving the recovery of proteins from FFPE tissues in a form suitable for proteomic analysis.

Elevated Pressure Improves the Extraction and Identification of Proteins Recovered from Formalin-Fixed, Paraffin-Embedded Tissue Surrogates

Science.gov (United States)

Fowler, Carol B.; Chesnick, Ingrid E.; Moore, Cedric D.; O'Leary, Timothy J.; Mason, Jeffrey T.

2010-01-01

Background Proteomic studies of formalin-fixed paraffin-embedded (FFPE) tissues are frustrated by the inability to extract proteins from archival tissue in a form suitable for analysis by 2-D gel electrophoresis or mass spectrometry. This inability arises from the difficulty of reversing formaldehyde-induced protein adducts and cross-links within FFPE tissues. We previously reported the use of elevated hydrostatic pressure as a method for efficient protein recovery from a hen egg-white lysozyme tissue surrogate, a model system developed to study formalin fixation and histochemical processing. Principal Findings In this study, we demonstrate the utility of elevated hydrostatic pressure as a method for efficient protein recovery from FFPE mouse liver tissue and a complex multi-protein FFPE tissue surrogate comprised of hen egg-white lysozyme, bovine carbonic anhydrase, bovine ribonuclease A, bovine serum albumin, and equine myoglobin (55∶15∶15∶10∶5 wt%). Mass spectrometry of the FFPE tissue surrogates retrieved under elevated pressure showed that both the low and high-abundance proteins were identified with sequence coverage comparable to that of the surrogate mixture prior to formaldehyde treatment. In contrast, non-pressure-extracted tissue surrogate samples yielded few positive and many false peptide identifications. Studies with soluble formalin-treated bovine ribonuclease A demonstrated that pressure modestly inhibited the rate of reversal (hydrolysis) of formaldehyde-induced protein cross-links. Dynamic light scattering studies suggest that elevated hydrostatic pressure and heat facilitate the recovery of proteins free of formaldehyde adducts and cross-links by promoting protein unfolding and hydration with a concomitant reduction in the average size of the protein aggregates. Conclusions These studies demonstrate that elevated hydrostatic pressure treatment is a promising approach for improving the recovery of proteins from FFPE tissues in a form

Recruitment of hypothalamic orexin neurons after formalin injections in adult male rats exposed to a neonatal immune challenge

Directory of Open Access Journals (Sweden)

Erin Jane Campbell

2015-03-01

Full Text Available Exposure to early life physiological stressors, such as infection, is thought to contribute to the onset of psychopathology in adulthood. In animal models, injections of the bacterial immune challenge, lipopolysaccharide (LPS, during the neonatal period has been shown to alter both neuroendocrine function and behavioural pain responses in adulthood. Interestingly, recent evidence suggests a role for the lateral hypothalamic peptide orexin in stress and nociceptive processing. However, whether neonatal LPS exposure affects the reactivity of the orexin system to formalin-induced inflammatory pain in later life remains to be determined. Male Wistar rats (n=13 were exposed to either LPS or saline (0.05mg/kg, i.p on postnatal days (PND 3 and 5. On PND 80-97, all rats were exposed to a subcutaneous hindpaw injection of 2.25% formalin. Following behavioural testing, animals were perfused and brains processed for Fos-protein and orexin immunohistochemistry. Rats treated with LPS during the neonatal period exhibited decreased licking behaviours during the interphase of the formalin test, the period typically associated with the active inhibition of pain, and increased grooming responses to formalin in adulthood. Interestingly, these behavioural changes were accompanied by an increase in the percentage of Fos-positive orexin cells in the dorsomedial and perifornical hypothalamus in LPS-exposed animals. Similar increases in Fos-protein were also observed in stress and pain sensitive brain regions that receive orexinergic inputs. These findings highlight a potential role for orexin in the behavioural responses to pain and provide further evidence that early life stress can prime the circuitry responsible for these responses in adulthood.

Screening in larval zebrafish reveals tissue-specific distribution of fifteen fluorescent compounds

Directory of Open Access Journals (Sweden)

Yuxiao Yao

2017-09-01

Full Text Available The zebrafish is a prominent vertebrate model for low-cost in vivo whole organism screening. In our recent screening of the distribution patterns of fluorescent compounds in live zebrafish larvae, fifteen compounds with tissue-specific distributions were identified. Several compounds were observed to accumulate in tissues where they were reported to induce side-effects, and compounds with similar structures tended to be enriched in the same tissues, with minor differences. In particular, we found three novel red fluorescent bone-staining dyes: purpurin, lucidin and 3-hydroxy-morindone; purpurin can effectively label bones in both larval and adult zebrafish, as well as in postnatal mice, without significantly affecting bone mass and density. Moreover, two structurally similar chemotherapeutic compounds, doxorubicin and epirubicin, were observed to have distinct distribution preferences in zebrafish. Epirubicin maintained a relatively higher concentration in the liver, and performed better in inhibiting hepatic hyperplasia caused by the over-expression of krasG12V. In total, our study suggests that the transparent zebrafish larvae serve as valuable tools for identifying tissue-specific distributions of fluorescent compounds.

Delta-ALA-mediated fluorescence spectroscopy of gastrointestinal tumors: comparison of in vivo and in vitro results

Science.gov (United States)

Vladimirov, B.; Borisova, E.; Avramov, L.

2007-06-01

The limitations of standard endoscopy for detection of dysplastic changes of mucosa are significant challenge and initiate development of new photodiagnostic techniques, additional to diagnostic possibilities of standard endoscopic equipment. One of the most widely examined optical modalities is the laser- or light-induced fluorescence spectroscopy (LIFS), because of its rapid and highly sensitive response to early biochemical and morphological changes in biological tissues. In the recent study delta-aminolevulinic acid/protoporphyrin IX is used as fluorescent marker for dysplasia and tumor detection in esophagus and stomach. The δ -ALA is administered per os six hours before measurements at dose 20mg/kg weight. High-power light-emitting diode at 405 nm is used as an excitation source. Special opto-mechanical device is built to use the light guide of standard video-endoscopic system. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. The fluorescence detected from in vivo tumor sites has very complex spectral origins. It consists of autofluorescence, fluorescence from exogenous fluorophores and re-absorption from the chromophores accumulated in the tissue investigated. Mucosa autofluorescence lies at 450-600 nm region. The fluorescence of PpIX is clearly pronounced at the 630-710 nm region. Deep minima in the tumor fluorescence signals are observed in the region 540-575 nm, related to hemoglobin re-absorption. Such high hemoglobin content is an indication of the tumors vascularization and it is clearly pronounced in all dysplastic and tumor sites investigated. After formalin conservation for in vitro samples hemoglobin absorption is strongly reduced that increases mucous fluorescence signal in green-yellow spectral region. Simultaneously the maxima at 635 nm and 720 nm are reduced.

Light-Induced Fluorescence Modulation of Quantum Dot-Crystal Violet Conjugates: Stochastic Off-On-Off Cycles for Multicolor Patterning and Super-Resolution.

Science.gov (United States)

Jung, Sungwook; Park, Joonhyuck; Bang, Jiwon; Kim, Jae-Yeol; Kim, Cheolhee; Jeon, Yongmoon; Lee, Seung Hwan; Jin, Ho; Choi, Sukyung; Kim, Bomi; Lee, Woo Jin; Pack, Chan-Gi; Lee, Jong-Bong; Lee, Nam Ki; Kim, Sungjee

2017-06-07

Photoswitching or modulation of quantum dots (QDs) can be promising for many fields that include display, memory, and super-resolution imaging. However, such modulations have mostly relied on photomodulations of conjugated molecules in QD vicinity, which typically require high power of high energy photons at UV. We report a visible light-induced facile modulation route for QD-dye conjugates. QD crystal violets conjugates (QD-CVs) were prepared and the crystal violet (CV) molecules on QD quenched the fluorescence efficiently. The fluorescence of QD-CVs showed a single cycle of emission burst as they go through three stages of (i) initially quenched "off" to (ii) photoactivated "on" as the result of chemical change of CVs induced by photoelectrons from QD and (iii) back to photodarkened "off" by radical-associated reactions. Multicolor on-demand photopatterning was demonstrated using QD-CV solid films. QD-CVs were introduced into cells, and excitation with visible light yielded photomodulation from "off" to "on" and "off" by nearly ten fold. Individual photoluminescence dynamics of QD-CVs was investigated using fluorescence correlation spectroscopy and single QD emission analysis, which revealed temporally stochastic photoactivations and photodarkenings. Exploiting the stochastic fluorescence burst of QD-CVs, simultaneous multicolor super-resolution localizations were demonstrated.

Chlorophyll induced fluorescence retrieved from GOME2 for improving gross primary productivity estimates of vegetation

Science.gov (United States)

van Leth, Thomas C.; Verstraeten, Willem W.; Sanders, Abram F. J.

2014-05-01

Mapping terrestrial chlorophyll fluorescence is a crucial activity to obtain information on the functional status of vegetation and to improve estimates of light-use efficiency (LUE) and global primary productivity (GPP). GPP quantifies carbon fixation by plant ecosystems and is therefore an important parameter for budgeting terrestrial carbon cycles. Satellite remote sensing offers an excellent tool for investigating GPP in a spatially explicit fashion across different scales of observation. The GPP estimates, however, still remain largely uncertain due to biotic and abiotic factors that influence plant production. Sun-induced fluorescence has the ability to enhance our knowledge on how environmentally induced changes affect the LUE. This can be linked to optical derived remote sensing parameters thereby reducing the uncertainty in GPP estimates. Satellite measurements provide a relatively new perspective on global sun-induced fluorescence, enabling us to quantify spatial distributions and changes over time. Techniques have recently been developed to retrieve fluorescence emissions from hyperspectral satellite measurements. We use data from the Global Ozone Monitoring Instrument 2 (GOME2) to infer terrestrial fluorescence. The spectral signatures of three basic components atmospheric: absorption, surface reflectance, and fluorescence radiance are separated using reference measurements of non-fluorescent surfaces (desserts, deep oceans and ice) to solve for the atmospheric absorption. An empirically based principal component analysis (PCA) approach is applied similar to that of Joiner et al. (2013, ACP). Here we show our first global maps of the GOME2 retrievals of chlorophyll fluorescence. First results indicate fluorescence distributions that are similar with that obtained by GOSAT and GOME2 as reported by Joiner et al. (2013, ACP), although we find slightly higher values. In view of optimizing the fluorescence retrieval, we will show the effect of the references

Involvement of nitridergic and opioidergic pathways in the antinociception of gabapentin in the orofacial formalin test in mice.

Science.gov (United States)

Miranda, Hugo F; Sierralta, Fernando; Lux, Sebastian; Troncoso, Rocío; Ciudad, Natalia; Zepeda, Ramiro; Zanetta, Pilar; Noriega, Viviana; Prieto, Juan Carlos

2015-04-01

Pain is one of the most common problems in clinical medicine. There is considerable evidence that pharmacologic approaches are the most widely used therapeutic options to ameliorate persistent or chronic pain. In this study it was evaluated the effect of l-NAME and naltrexone in the antinociception induced by administration of gabapentin in the orofacial formalin test of mice. The algesiometer assay was performed by the administration of 20 μl of 2% formalin solution injected into the upper right lip of each mouse. The dose of gabapentin that produces the 50% of the maximum possible effect (ED50) was significantly increased by the pretreatment with l-NAME or naltrexone. These results suggest that gabapentin produce antinociception partly via the activation nitridergic pathways and opioid system. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Development of a new light collection and detection system optimized for ion beam induced fluorescence microscopy

International Nuclear Information System (INIS)

Vanga, Sudheer Kumar; Mi, Zhaohong; Koh, Long Cheng; Tao, Ye; Bettiol, Andrew A.; Watt, Frank

2015-01-01

Ion beam induced fluorescence microscopy is a new imaging technique which has the potential to achieve sub-50 nm spatial resolution fluorescence images. Currently the resolution of the technique has been limited to around 150 nm mainly because of inefficient collection and detection of emitted photons from the sample. To overcome this limitation, a new light collection system based on a custom made parabolic mirror is employed to enhance the fluorescence collection. The custom made mirror is designed so as to obtain both structural (scanning transmission ion microscopy) and ion beam induced fluorescence imaging simultaneously. The design and characterization of the parabolic mirror is discussed in detail

Laser-induced fluorescences due to quadrupole moment transition and Stark effect in a He glow discharge

International Nuclear Information System (INIS)

Sakai, Hisashi; Takiyama, Ken; Kimura, Masahiko; Yamasaki, Motokuni; Fujita, Toshiaki; Oda, Toshiatsu; Kawasaki, Ken.

1993-01-01

The electric quadrupole moment transition and the Stark effect are investigated in a He hollow cathode discharge with laser-induced fluorescence method. It is shown that the forbidden transition from 2 1 S to 3 1 D in the negative glow is dominantly due to the quadrupole moment transition. This absorption coefficient is obtained from the laser-induced fluorescence intensity measurement in which the collisional transfers are taken into account. The result agrees with the theoretical coefficient. In the cathode dark space the fluorescence due to the Stark effect is also observed. Spatial distribution of the fluorescence is discussed, compared with the electric field distribution in the dark space. (author)

Detection of vegetation stress from laser-induced fluorescence signatures

International Nuclear Information System (INIS)

Subhash, N.

1995-01-01

The in vivo laser-induced fluorescence (LIF) signatures of UV irradiated Salvia splendens plants were measured using an Optical Multichannel Analyser (OMA) system with Nitrogen laser excitation. The LIF spectra which consisted of the blue-green and the red chlorophyll bands were analysed with a non-linear interactive procedure using Gaussian spectral functions. The fluorescence intensity ratios of the various bands obtained from curve fitted parameters were found to be more sensitive to changes in the photosynthetic activity of the plant. The variation in the intensity ratio for the chlorophyll bands for nutrient stressed sunflower, cotton and groundnut plants as well as the nutrient and water stressed rice plants are also presented. It is observed that vegetation stress not only changes the fluorescence intensity ratios and the vitality index of the plant but also changes the peak position of the emission bands, in some cases. It is also seen that analysis of the fluorescence spectra in vegetation remote sensing applications would require a deconvolution procedure to evaluate the exact contribution of each band in the total spectra. (author). 23 refs, 8 figs, 5 tabs

Fluorescence lifetime components reveal kinetic intermediate states upon equilibrium denaturation of carbonic anhydrase II.

Science.gov (United States)

Nemtseva, Elena V; Lashchuk, Olesya O; Gerasimova, Marina A; Melnik, Tatiana N; Nagibina, Galina S; Melnik, Bogdan S

2017-12-21

In most cases, intermediate states of multistage folding proteins are not 'visible' under equilibrium conditions but are revealed in kinetic experiments. Time-resolved fluorescence spectroscopy was used in equilibrium denaturation studies. The technique allows for detecting changes in the conformation and environment of tryptophan residues in different structural elements of carbonic anhydrase II which in its turn has made it possible to study the intermediate states of carbonic anhydrase II under equilibrium conditions. The results of equilibrium and kinetic experiments using wild-type bovine carbonic anhydrase II and its mutant form with the substitution of leucine for alanine at position 139 (L139A) were compared. The obtained lifetime components of intrinsic tryptophan fluorescence allowed for revealing that, the same as in kinetic experiments, under equilibrium conditions the unfolding of carbonic anhydrase II ensues through formation of intermediate states.

Detection of c-myc amplification in formalin-fixed paraffin-embedded tumor tissue by chromogenic in situ hybridization (CISH).

Science.gov (United States)

Todorović-Raković, Nataša

2013-01-01

In situ hybridization (ISH) allows evaluation of genetic abnormalities, such as changes in chromosome number, chromosome translocations or gene amplifications, by hybridization of tagged DNA (or RNA) probes with complementary DNA (or RNA) sequences in interphase nuclei of target tissue. However, chromogenic in situ hybridization (CISH) is also applicable to formalin-fixed, paraffin-embedded (FFPE) tissues, besides metaphase chromosome spreads. CISH is similar to fluorescent in situ hybridization (FISH) regarding pretreatments and hybridization protocols but differs in the way of visualization. Indeed, CISH signal detection is similar to that used in immunohistochemistry, making use of a peroxidase-based chromogenic reaction instead of fluorescent dyes. In particular, tagged DNA probes are indirectly detected using an enzyme-conjugated antibody targeting the tags. The enzymatic reaction of the chromogenic substrate leads to the formation of strong permanent brown signals that can be visualized by bright-field microscopy at 40 × magnification. The advantage of CISH is that it allows the simultaneous observation of gene amplification and tissue morphology and the slides can be stored for a long time.

A fluorescence-based rapid screening assay for cytotoxic compounds

International Nuclear Information System (INIS)

Montoya, Jessica; Varela-Ramirez, Armando; Estrada, Abril; Martinez, Luis E.; Garza, Kristine; Aguilera, Renato J.

2004-01-01

A simple fluorescence-based assay was developed for the rapid screening of potential cytotoxic compounds generated by combinatorial chemistry. The assay is based on detection of nuclear green fluorescent protein (GFP) staining of a human cervical cancer cell line (HeLa) carrying an integrated histone H2B-GFP fusion gene. Addition of a cytotoxic compound to the HeLa-GFP cells results in the eventual degradation of DNA and loss of the GFP nuclear fluorescence. Using this assay, we screened 11 distinct quinone derivatives and found that several of these compounds were cytotoxic. These compounds are structurally related to plumbagin an apoptosis-inducing naphthoquinone isolated from Black Walnut. In order to determine the mechanism by which cell death was induced, we performed additional experiments with the most cytotoxic quinones. These compounds were found to induce morphological changes (blebbing and nuclear condensation) consistent with induction of apoptosis. Additional tests revealed that the cytotoxic compounds induce both necrotic and apoptotic modes of death

Predicting the concentration of residual methanol in industrial formalin using machine learning

OpenAIRE

Heidkamp, William

2016-01-01

In this thesis, a machine learning approach was used to develop a predictive model for residual methanol concentration in industrial formalin produced at the Akzo Nobel factory in Kristinehamn, Sweden. The MATLABTM computational environment supplemented with the Statistics and Machine LearningTM toolbox from the MathWorks were used to test various machine learning algorithms on the formalin production data from Akzo Nobel. As a result, the Gaussian Process Regression algorithm was found to pr...

Sun-induced fluorescence - a new probe of photosynthesis: First maps from the imaging spectrometer HyPlant.

Science.gov (United States)

Rascher, U; Alonso, L; Burkart, A; Cilia, C; Cogliati, S; Colombo, R; Damm, A; Drusch, M; Guanter, L; Hanus, J; Hyvärinen, T; Julitta, T; Jussila, J; Kataja, K; Kokkalis, P; Kraft, S; Kraska, T; Matveeva, M; Moreno, J; Muller, O; Panigada, C; Pikl, M; Pinto, F; Prey, L; Pude, R; Rossini, M; Schickling, A; Schurr, U; Schüttemeyer, D; Verrelst, J; Zemek, F

2015-12-01

Variations in photosynthesis still cause substantial uncertainties in predicting photosynthetic CO2 uptake rates and monitoring plant stress. Changes in actual photosynthesis that are not related to greenness of vegetation are difficult to measure by reflectance based optical remote sensing techniques. Several activities are underway to evaluate the sun-induced fluorescence signal on the ground and on a coarse spatial scale using space-borne imaging spectrometers. Intermediate-scale observations using airborne-based imaging spectroscopy, which are critical to bridge the existing gap between small-scale field studies and global observations, are still insufficient. Here we present the first validated maps of sun-induced fluorescence in that critical, intermediate spatial resolution, employing the novel airborne imaging spectrometer HyPlant. HyPlant has an unprecedented spectral resolution, which allows for the first time quantifying sun-induced fluorescence fluxes in physical units according to the Fraunhofer Line Depth Principle that exploits solar and atmospheric absorption bands. Maps of sun-induced fluorescence show a large spatial variability between different vegetation types, which complement classical remote sensing approaches. Different crop types largely differ in emitting fluorescence that additionally changes within the seasonal cycle and thus may be related to the seasonal activation and deactivation of the photosynthetic machinery. We argue that sun-induced fluorescence emission is related to two processes: (i) the total absorbed radiation by photosynthetically active chlorophyll; and (ii) the functional status of actual photosynthesis and vegetation stress. © 2015 John Wiley & Sons Ltd.

Influence of copper and formalin on the mycorrhiza of pine (Pinus kesiya Royle ex Gordon

Directory of Open Access Journals (Sweden)

G. D. Sharma

2014-08-01

Full Text Available Various concentrations of copper sulphate and formalin were tested for their effect on the efficiency of mycorrhizal functioning in pine seedlings. Low and higher doses of copper applied to the container grown seedling exhibited a less stimulatory effect than nedium doses. When applied in higher concentrations, the formalin caused mortality in young pine seedlings. The seedling yield and phosphate uptake was found maximum in 100 ppm applied concentration of copper. while słów growth and lower phosphate concentration was observed in the seedlings not given any copper treatment. Formalin at 50 ppm concentration slightly improved the seedling growth and phosphate uptake in mycorrhizal seedling as compared with untreated ones. Variation in the development and spread of ectomycorrhiza on the surface of roots of pine seedlings was also recorded in responses to copper and formalin treatments.

The Antinociceptive Effects of Iranian Cobra Snake Venom using Formalin Test

Directory of Open Access Journals (Sweden)

Zahra Hadi Chegeni

2015-06-01

Full Text Available Abstract Background: There have been numerous reports of snake venoms being employed as analgesics in attempts to relieve severe pain associated with cancer, immune dysfunction and viral infections. This study investigates the antinociceptive effects of iranian cobra snake venom (Naja naja oxiana in comparison with morphine and lidocain on laboratorial femal mice. Materials and Methods: This study has been done on 48 NMRI female mice of 18-20 g in weight. Antinociceptive activeity of snake venom was evaluated by formalin test. In this test, the animals were divided into 6 groups (each group consisting of 8 mice: Sham, positive Control (receiving morphine at dose of 5 mg/kg, and receiving lidocain at dose of 20 mg/kg, and experimental groups receiving venom at doses of 1, 3 and 4/5 µg/mice. In all groups, the formalin test was recorded for 60 min after administration of venom and drugs in mice. Data were analyzed using one-way ANOVA and Tukey test. Results: The results showed that the venom of Naja naja oxiana decreased nociception meaningfully in both acute and chronic phases. We also showed that this venom revealed even a better analgesic activity in comparison with morphine and lidocain. Conclusion: This study showed that the antinociceptive effect of the venom was mediated through central nervous system and peripheral mechanisms. Although details of the mechanism remain unclear, and further studies should be considered to demonstrate its therapeutic effects.

Laser induced fluorescence thermometry (LIF-T) as a non-invasive temperature measurement technique for thermal hydraulic experiments

Energy Technology Data Exchange (ETDEWEB)

Strack, J.; Leung, K.; Walker, A., E-mail: strackj@mcmaster.ca [McMaster Univ., Hamilton, ON (Canada)

2014-07-01

Laser induced fluorescence (LIF) is an experimental technique whereby a scalar field in a fluid system is measured optically from the fluorescence intensity of a tracer dye following excitation by laser light. For laser induced fluorescence thermometry (LIF-T), a temperature sensitive dye is used. Through the use of a temperature sensitive tracer dye, sheet laser optics, optical filters, and photography, a 2D temperature field can be measured non-invasively. An experiment to test the viability of using LIF-T for macroscopic thermal hydraulic experiments was developed and tested. A reference calibration curve to relate fluorescence measurements to temperature is presented. (author)

Atmospheric CO2 Observations Reveal Strong Correlation Between Regional Net Biospheric Carbon Uptake and Solar-Induced Chlorophyll Fluorescence

Science.gov (United States)

Shiga, Yoichi P.; Tadić, Jovan M.; Qiu, Xuemei; Yadav, Vineet; Andrews, Arlyn E.; Berry, Joseph A.; Michalak, Anna M.

2018-01-01

Recent studies have shown the promise of remotely sensed solar-induced chlorophyll fluorescence (SIF) in informing terrestrial carbon exchange, but analyses have been limited to either plot level ( 1 km2) or hemispheric/global ( 108 km2) scales due to the lack of a direct measure of carbon exchange at intermediate scales. Here we use a network of atmospheric CO2 observations over North America to explore the value of SIF for informing net ecosystem exchange (NEE) at regional scales. We find that SIF explains space-time NEE patterns at regional ( 100 km2) scales better than a variety of other vegetation and climate indicators. We further show that incorporating SIF into an atmospheric inversion leads to a spatial redistribution of NEE estimates over North America, with more uptake attributed to agricultural regions and less to needleleaf forests. Our results highlight the synergy of ground-based and spaceborne carbon cycle observations.

Controllable ultra-narrow fluorescence and six-wave mixing under double electromagnetically induced transparency

International Nuclear Information System (INIS)

Wang, Z G; Zhang, Z Y; Che, J L; Zhang, Y Z; Li, C B; Zheng, H B; Zhang, Y P

2013-01-01

We report the first observation of six-wave mixing (SWM) and fluorescence signals in an electromagnetically induced transparency (EIT) window. Several remarkable advantages are described. First, multiple bright and dark states are simultaneously observed due to enhancement or suppression of the SWM signal. Second, ultra-narrow fluorescence, much narrower than the EIT window, is experimentally obtained. Third, the ultra-narrow fluorescence can also generate Autler–Townes splitting on scanning the coupling beam. Fourth, a double-peak EIT window is obtained using the nest-dressing scheme. Such studies concerning SWM and fluorescence have applications in optical switching, multi-channel communication and narrowband and long-range quantum communication. (letter)

Fabrication of fluorescent silica nanoparticles with aggregation-induced emission luminogens for cell imaging.

Science.gov (United States)

Chen, Sijie; Lam, Jacky W Y; Tang, Ben Zhong

2013-01-01

Fluorescence-based techniques have found wide applications in life science. Among various luminogenic materials, fluorescent nanoparticles have attracted much attention due to their fabulous emission properties and potential applications as sensors. Here, we describe the fabrication of fluorescent silica nanoparticles (FSNPs) containing aggregation-induced emission (AIE) luminogens. By employing surfactant-free sol-gel reaction, FSNPs with uniform size and high surface charge and colloidal stability are generated. The FSNPs emit strong light upon photoexcitation, due to the AIE characteristic of the silole -aggregates in the hybrid nanoparticles. The FSNPs are cytocompatible and can be utilized as fluorescent visualizer for intracellular imaging for HeLa cells.

Blood perfusion and pH monitoring in organs by laser-induced fluorescence spectroscopy

Science.gov (United States)

Vari, Sandor G.; Papazoglou, Theodore G.; Pergadia, Vani R.; Stavridi, Marigo; Snyder, Wendy J.; Papaioannou, Thanassis; Duffy, J. T.; Weiss, Andrew B.; Thomas, Reem; Grundfest, Warren S.

1994-01-01

Sensitivity of laser-induced fluorescence spectroscopy (LIFS) in detecting a change in tissue pH, and blood perfusion was determined. Rabbits were anesthetized, paralyzed, and mechanically ventilated. The arterial and venous blood supplies of the kidney were isolated and ligated to alter the perfusion. The femoral artery was cannulated to extract samples for blood gas analysis. A 308-nm XeCl was used as an excitation source. A 600 micrometers core diameter fiber was used for fluorescence acquisition, and the spectra analyzed by an optical multichannel analyzer (EG & G, OMA III). the corresponding intensity ratio R equals INADH / ICOLL was used as an index for respiratory acidosis. Blood perfusion was assessed using the following algorithm: (IELAS minus ICOLL) divided by (INADH minus ICOLL). The intensity ratio linearly decreased with the reduction of blood perfusion. When we totally occluded the artery the ratio decreased tenfold when compared to the ratio of a fully perfused kidney. Results of monitoring blood acidosis by laser-induced fluorescence spectroscopy shows a significant trend between pH and intensity ratio. Since all the slopes were negative, there is an obvious significant correlation between the pH and NADH.COLLAGEN RATIO. Blue-light-induced fluorescence measurements and ratio fluorometry is a sensitive method for monitoring blood perfusion and acidity or alkalinity of an organ.

Experimental Research of Reliability of Plant Stress State Detection by Laser-Induced Fluorescence Method

Directory of Open Access Journals (Sweden)

Yury Fedotov

2016-01-01

Full Text Available Experimental laboratory investigations of the laser-induced fluorescence spectra of watercress and lawn grass were conducted. The fluorescence spectra were excited by YAG:Nd laser emitting at 532 nm. It was established that the influence of stress caused by mechanical damage, overwatering, and soil pollution is manifested in changes of the spectra shapes. The mean values and confidence intervals for the ratio of two fluorescence maxima near 685 and 740 nm were estimated. It is presented that the fluorescence ratio could be considered a reliable characteristic of plant stress state.

Contrast Induced by a Static Magnetic Field for Improved Detection in Nanodiamond Fluorescence Microscopy

Science.gov (United States)

Singam, Shashi K. R.; Motylewski, Jaroslaw; Monaco, Antonina; Gjorgievska, Elena; Bourgeois, Emilie; Nesládek, Milos; Giugliano, Michele; Goovaerts, Etienne

2016-12-01

Diamond nanoparticles with negatively charged nitrogen-vacancy (NV) centers are highly efficient nonblinking emitters that exhibit spin-dependent intensity. An attractive application of these emitters is background-free fluorescence microscopy exploiting the fluorescence quenching induced either by resonant microwaves (RMWs) or by an applied static magnetic field (SMF). Here, we compare RMW- and SMF-induced contrast measurements over a wide range of optical excitation rates for fluorescent nanodiamonds (FNDs) and for NV centers shallowly buried under the (100)-oriented surface of a diamond single crystal (SC). Contrast levels are found to be systematically lower in the FNDs than in the SC. At low excitation rates, the RMW contrast initially rises to a maximum (up to 7% in FNDs and 13% in the SC) but then decreases steadily at higher intensities. Conversely, the SMF contrast increases from approximately 12% at low excitation rates to high values of 20% and 38% for the FNDs and SC, respectively. These observations are well described in a rate-equations model for the charged NV defect using parameters in good agreement with the literature. The SMF approach yields higher induced contrast in image collection under commonly applied optical excitation. Unlike the RMW method, there is no thermal load exerted on the aqueous media in biological samples in the SMF approach. We demonstrate imaging by SMF-induced contrast in neuronal cultures incorporating FNDs (i) in a setup for patch-clamp experiments in parallel with differential-interference-contrast microscopy, (ii) after a commonly used staining procedure as an illustration of the high selectivity against background fluorescence, and (iii) in a confocal fluorescence microscope in combination with bright-field microscopy.

Fluorescence resonance energy transfer (FRET-based subcellular visualization of pathogen-induced host receptor signaling

Directory of Open Access Journals (Sweden)

Zimmermann Timo

2009-11-01

Full Text Available Abstract Background Bacteria-triggered signaling events in infected host cells are key elements in shaping the host response to pathogens. Within the eukaryotic cell, signaling complexes are spatially organized. However, the investigation of protein-protein interactions triggered by bacterial infection in the cellular context is technically challenging. Here, we provide a methodological approach to exploit fluorescence resonance energy transfer (FRET to visualize pathogen-initiated signaling events in human cells. Results Live-cell microscopy revealed the transient recruitment of the Src family tyrosine kinase Hck upon bacterial engagement of the receptor carcinoembryonic antigen-related cell adhesion molecule 3 (CEACAM3. In cells expressing a CEACAM3 variant lacking the cytoplasmic domain, the Src homology 2 (SH2 domain of Hck (Hck-SH2 was not recruited, even though bacteria still bound to the receptor. FRET measurements on the basis of whole cell lysates revealed intimate binding between Hck-SH2 (using enhanced yellow fluorescent protein (YPet-Hck-SH2 and the tyrosine-phosphorylated enhanced cyan fluorescent protein-labeled cytoplasmic domain of wild-type CEACAM3 (CEACAM3 WT-CyPet and a flow cytometry-based FRET approach verified this association in intact cells. Using confocal microscopy and acceptor photobleaching, FRET between Hck-SH2 and CEACAM3 was localized to the sites of bacteria-host cell contact. Conclusion These data demonstrate not only the intimate binding of the SH2 domain of Hck to the tyrosine-phosphorylated cytoplasmic domain of CEACAM3 in intact cells, but furthermore, FRET measurements allow the subcellular localization of this process during bacterial infection. FRET-based assays are valuable tools to resolve bacteria-induced protein-protein interactions in the context of the intact host cell.

PrPSc detection in formalin-fixed paraffin-embedded tissue by ELISA

Directory of Open Access Journals (Sweden)

Nicholson Eric M

2011-10-01

Full Text Available Abstract Background Formalin-fixed paraffin-embedded tissue is regularly employed in the diagnosis of transmissible spongiform encephalopathies (TSE by immunohistochemistry (IHC, the standard by which all other TSE diagnostic protocols are judged. While IHC affords advantages over diagnostic approaches that typically utilize fresh or frozen tissue, such as Western blot and ELISA, the process of fixing, staining, and analyzing individual sections by hand does not allow for rapid or high throughput screening. However, preservation of tissues in formalin is not dependent upon the availability of refrigeration. Findings Formalin-fixed paraffin-embedded tissues from TSE transmission studies of scrapie in sheep, chronic wasting disease in white-tailed deer or transmissible mink encephalopathy in cattle were cut at 5 μm thickness. Samples containing the tissue equivalent of as little as one 5 μm section can be used to readily discriminate positive from negative samples. Conclusions This approach cannot replace IHC but may be used along with IHC as both a more rapid and readily high throughput screen where fresh or frozen tissues are not available or impractical.

Stepwise multiphoton activation fluorescence reveals a new method of melanin detection

Science.gov (United States)

Lai, Zhenhua; Kerimo, Josef; Mega, Yair; DiMarzio, Charles A.

2013-06-01

The stepwise multiphoton activated fluorescence (SMPAF) of melanin, activated by a continuous-wave mode near infrared (NIR) laser, reveals a broad spectrum extending from the visible spectra to the NIR and has potential application for a low-cost, reliable method of detecting melanin. SMPAF images of melanin in mouse hair and skin are compared with conventional multiphoton fluorescence microscopy and confocal reflectance microscopy (CRM). By combining CRM with SMPAF, we can locate melanin reliably. However, we have the added benefit of eliminating background interference from other components inside mouse hair and skin. The melanin SMPAF signal from the mouse hair is a mixture of a two-photon process and a third-order process. The melanin SMPAF emission spectrum is activated by a 1505.9-nm laser light, and the resulting spectrum has a peak at 960 nm. The discovery of the emission peak may lead to a more energy-efficient method of background-free melanin detection with less photo-bleaching.

Laser induced fluorescence of trapped molecular ions

Energy Technology Data Exchange (ETDEWEB)

Grieman, F.J.

1979-10-01

An experimental apparatus for obtaining the optical spectra of molecular ions is described. The experimental technique includes the use of three dimensional ion trapping, laser induced fluorescence, and gated photon counting methods. The ions, which are produced by electron impact, are confined in a radio-frequency quadrupole ion trap of cylindrical design. Because the quadrupole ion trap allows mass selection of the molecular ion desired for study, the analysis of the spectra obtained is greatly simplified. The ion trap also confines the ions to a region easily probed by a laser beam. 18 references.

Laser induced fluorescence of trapped molecular ions

International Nuclear Information System (INIS)

Grieman, F.J.

1979-10-01

An experimental apparatus for obtaining the optical spectra of molecular ions is described. The experimental technique includes the use of three dimensional ion trapping, laser induced fluorescence, and gated photon counting methods. The ions, which are produced by electron impact, are confined in a radio-frequency quadrupole ion trap of cylindrical design. Because the quadrupole ion trap allows mass selection of the molecular ion desired for study, the analysis of the spectra obtained is greatly simplified. The ion trap also confines the ions to a region easily probed by a laser beam. 18 references

In-vivo cancer diagnosis of the esophagus using laser-induced fluorescence

Science.gov (United States)

Vo-Dinh, Tuan; Panjehpour, Masoud; Overholt, Bergein F.; Buckley, Paul F., II; Edwards, Donna H.

1995-04-01

Laser-induced fluorescence (LIF) was used for direct in-vivo cancer diagnosis of the esophagus without requiring biopsy. The methodology was applied to differentiate normal and malignant tumors of the esophagus. Endogenous fluorescence of normal and malignant tissues were measured directly using a fiberoptic probe inserted through an endoscope. The measurements were performed in vivo during routine endoscopy. Detection of the fluorescence signal from the tissue was performed using laser excitation. The results of this LIF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement in the classification of normal and malignant tumors for the samples investigated. The LIF procedure could lead to the development of a rapid and cost-effective technique for cancer diagnosis.

Detection of bacterial infection of agave plants by laser-induced fluorescence

Science.gov (United States)

Cervantes-Martinez, Jesus; Flores-Hernandez, Ricardo; Rodriguez-Garay, Benjamin; Santacruz-Ruvalcaba, Fernando

2002-05-01

Greenhouse-grown plants of Agave tequilana Weber var. azul were inoculated with Erwinia carotovora, the causal agent of stem soft rot. We investigated the laser-induced fluorescence (LIF) of agave plants to determine whether LIF can be used as a noninvasive sensing tool for pathological studies. The LIF technique was also investigated as a means of detecting the effect of the polyamine biosynthesis inhibitor beta-hydroxyethylhydrazine as a bactericide against the pathogenic bacterium Erwinia carotovora. A He-Ne laser at 632.8 nm was used as the excitation source, and in vivo fluorescence emission spectra were recorded in the 660-790-range. Fluorescence maxima were at 690 and 740 nm. The infected plants that were untreated with the bactericide showed a definite increase in fluorescence intensity at both maxima within the first three days after infection. Beginning on the fifth day, a steady decrease in fluorescence intensity was observed, with a greater effect at 740 than at 690 nm. After 30 days there was no fluorescence. The infected plants that had been treated with the bactericide showed no significant change in fluorescence compared with that of the uninfected plants. The ratio of fluorescence intensities was determined to be F 690 nm/F 740 nm for all treatments. These studies indicate that LIF measurements of agave plants may be used for the early detection of certain types of disease and for determining the effect of a bactericide on bacteria. The results also showed that fluorescence intensity ratios can be used as a reliable indicator of the progress of disease.

Experimentally studied laser fluorescence method for remote sensing of plant stress situation induced by improper plants watering

Directory of Open Access Journals (Sweden)

Yu. V. Fedotov

2014-01-01

Full Text Available Stressful situations of plants can be caused by a lack of nutrients; mechanical damages; diseases; low or high temperatures; lack of illumination; insufficient or excess humidity of the soil; soil salinization; soil pollution by oil products or heavy metals; the increased acidity of the soil; use of pesticides, herbicides, insecticides, etc.At early stages it is often difficult to detect seemingly that the plants are in stressful situations caused by adverse external factors. However, the fluorescent analysis potentially allows detection of the stressful situations of plants by deformation of laser-induced fluorescence spectra. The paper conducts experimental investigations to learn the capabilities of the laser fluorescent method to monitor plant situations at 532nm wavelength of fluorescence excitation in the stressful situations induced by improper watering (at excess of moisture in the soil and at a lack of moisture.Researches of fluorescence spectra have been conducted using a created laboratory installation. As a source to excite fluorescence radiation the second harmonica of YAG:Nd laser is used. The subsystem to record fluorescence radiation is designed using a polychromator and a highly sensitive matrix detector with the amplifier of brightness.Experimental investigations have been conducted for fast-growing and unpretentious species of plants, namely different sorts of salad.Experimental studies of laser-induced fluorescence spectra of plants for 532nm excitement wavelength show that the impact of stressful factors on a plant due to the improper watering, significantly distorts a fluorescence spectrum of plants. Influence of a stressful factor can be shown as a changing profile of a fluorescence spectrum (an identifying factor, here, is a relationship of fluorescence intensities at two wavelengths, namely 685 nm and 740 nm or (and as a changing level of fluorescence that can be the basis for the laser method for monitoring the plant

Laser-Induced Fluorescence Detection in High-Throughput Screening of Heterogeneous Catalysts and Single Cells Analysis

Energy Technology Data Exchange (ETDEWEB)

Su, Hui [Iowa State Univ., Ames, IA (United States)

2001-01-01

Laser-induced fluorescence detection is one of the most sensitive detection techniques and it has found enormous applications in various areas. The purpose of this research was to develop detection approaches based on laser-induced fluorescence detection in two different areas, heterogeneous catalysts screening and single cell study. First, the author introduced laser-induced imaging (LIFI) as a high-throughput screening technique for heterogeneous catalysts to explore the use of this high-throughput screening technique in discovery and study of various heterogeneous catalyst systems. This scheme is based on the fact that the creation or the destruction of chemical bonds alters the fluorescence properties of suitably designed molecules. By irradiating the region immediately above the catalytic surface with a laser, the fluorescence intensity of a selected product or reactant can be imaged by a charge-coupled device (CCD) camera to follow the catalytic activity as a function of time and space. By screening the catalytic activity of vanadium pentoxide catalysts in oxidation of naphthalene, they demonstrated LIFI has good detection performance and the spatial and temporal resolution needed for high-throughput screening of heterogeneous catalysts. The sample packing density can reach up to 250 x 250 subunits/cm² for 40-μm wells. This experimental set-up also can screen solid catalysts via near infrared thermography detection. In the second part of this dissertation, the author used laser-induced native fluorescence coupled with capillary electrophoresis (LINF-CE) and microscope imaging to study the single cell degranulation. On the basis of good temporal correlation with events observed through an optical microscope, they have identified individual peaks in the fluorescence electropherograms as serotonin released from the granular core on contact with the surrounding fluid.

Mapping metals in Parkinson's and normal brain using rapid-scanning x-ray fluorescence

International Nuclear Information System (INIS)

Popescu, Bogdan F Gh; George, Martin J; McCrea, Richard P E; Devon, Richard M; George, Graham N; Hanson, Akela D; Chapman, L Dean; Nichol, Helen; Bergmann, Uwe; Garachtchenko, Alex V; Luening, Katharina; Kelly, Michael E; Harder, Sheri M; Pickering, Ingrid J

2009-01-01

Rapid-scanning x-ray fluorescence (RS-XRF) is a synchrotron technology that maps multiple metals in tissues by employing unique hardware and software to increase scanning speed. RS-XRF was validated by mapping and quantifying iron, zinc and copper in brain slices from Parkinson's disease (PD) and unaffected subjects. Regions and structures in the brain were readily identified by their metal complement and each metal had a unique distribution. Many zinc-rich brain regions were low in iron and vice versa. The location and amount of iron in brain regions known to be affected in PD agreed with analyses using other methods. Sample preparation is simple and standard formalin-fixed autopsy slices are suitable. RS-XRF can simultaneously and non-destructively map and quantify multiple metals and holds great promise to reveal metal pathologies associated with PD and other neurodegenerative diseases as well as diseases of metal metabolism.

Laser induced fluorescence of trapped molecular ions

International Nuclear Information System (INIS)

Winn, J.S.

1980-10-01

Laser induced fluoresence (LIF) spectra (laser excitation spectra) are conceptually among the most simple spectra to obtain. One need only confine a gaseous sample in a suitable container, direct a laser along one axis of the container, and monitor the sample's fluorescence at a right angle to the laser beam. As the laser wavelength is changed, the changes in fluorescence intensity map the absorption spectrum of the sample. (More precisely, only absorption to states which have a significant radiative decay component are monitored.) For ion spectroscopy, one could benefit in many ways by such an experiment. Most optical ion spectra have been observed by emission techniques, and, aside from the problems of spectral analysis, discharge emission methods often produce the spectra of many species, some of which may be unknown or uncertain. Implicit in the description of LIF given above is certainty as to the chemical identity of the carrier of the spectrum. This article describes a method by which the simplifying aspects of LIF can be extended to molecular ions

Multiphoton fluorescence lifetime imaging of chemotherapy distribution in solid tumors

Science.gov (United States)

Carlson, Marjorie; Watson, Adrienne L.; Anderson, Leah; Largaespada, David A.; Provenzano, Paolo P.

2017-11-01

Doxorubicin is a commonly used chemotherapeutic employed to treat multiple human cancers, including numerous sarcomas and carcinomas. Furthermore, doxorubicin possesses strong fluorescent properties that make it an ideal reagent for modeling drug delivery by examining its distribution in cells and tissues. However, while doxorubicin fluorescence and lifetime have been imaged in live tissue, its behavior in archival samples that frequently result from drug and treatment studies in human and animal patients, and murine models of human cancer, has to date been largely unexplored. Here, we demonstrate imaging of doxorubicin intensity and lifetimes in archival formalin-fixed paraffin-embedded sections from mouse models of human cancer with multiphoton excitation and multiphoton fluorescence lifetime imaging microscopy (FLIM). Multiphoton excitation imaging reveals robust doxorubicin emission in tissue sections and captures spatial heterogeneity in cells and tissues. However, quantifying the amount of doxorubicin signal in distinct cell compartments, particularly the nucleus, often remains challenging due to strong signals in multiple compartments. The addition of FLIM analysis to display the spatial distribution of excited state lifetimes clearly distinguishes between signals in distinct compartments such as the cell nuclei versus cytoplasm and allows for quantification of doxorubicin signal in each compartment. Furthermore, we observed a shift in lifetime values in the nuclei of transformed cells versus nontransformed cells, suggesting a possible diagnostic role for doxorubicin lifetime imaging to distinguish normal versus transformed cells. Thus, data here demonstrate that multiphoton FLIM is a highly sensitive platform for imaging doxorubicin distribution in normal and diseased archival tissues.

Responses of sun-induced chlorophyll fluorescence to biological and environmental variations measured with a versatile Fluorescence Auto-Measurement Equipment (FAME)

Science.gov (United States)

Gu, L.

2017-12-01

In this study, we examine responses of sun-induced chlorophyll fluorescence to biological and environmental variations measured with a versatile Fluorescence Auto-Measurement Equipment (FAME). FAME was developed to automatically and continuously measure chlorophyll fluorescence (F) of a leaf, plant or canopy in both laboratory and field environments, excited by either artificial light source or sunlight. FAME is controlled by a datalogger and allows simultaneous measurements of environmental variables complementary to the F signals. A built-in communication system allows FAME to be remotely monitored and data-downloaded. Radiance and irradiance calibrations can be done online. FAME has been applied in a variety of environments, allowing an investigation of biological and environmental controls on F emission.

Probing focal cortical dysplasia in formalin fixed samples using tissue optical spectroscopy

Science.gov (United States)

Anand, Suresh; Cicchi, Riccardo; Giordano, Flavio; Buccoliero, Anna Maria; Conti, Valerio; Guerrini, Renzo; Pavone, Francesco Saverio

2016-03-01

Focal cortical dysplasia (FCD) is one of most common causes of intractable epilepsy in pediatric population and these are often insensitive to anti-epileptic drugs. FCD is characterized by a disarray in localized regions of the cerebral cortex and abnormal neurons which results them to misfire with incorrect signals. Resective neurosurgery to remove or disconnect the affected parts from the rest of the brain seems to be a viable option to treat FCD. Before neurosurgery the subject could undergo imaging studies including magnetic resonance imaging (MRI) or computed tomography (CT) scans. On the downside FCD could be elusive in MRI images and may be practically invisible in CT scans. Furthermore, unnecessary removal of normal tissues is to be taken into consideration as this could lead to neurological defects. In this context, optical spectroscopy have been widely investigated as an alternative technique for the detection of abnormal tissues in different organ sites. Disease progression is accompanied by a number of architectural, biochemical and morphological changes. These variations are reflected in the spectral intensity and line shape. Here, in this proof of concept study we propose to investigate the application of tissue optical spectroscopy based on fluorescence excitation at two wavelength 378 and 445 nm coupled along with Raman spectroscopy for the detection of FCD on formalin fixed tissue specimens from pediatric subjects. For fluorescence at both the excitation wavelengths FCD showed a decreased intensity at longer wavelength when compared to normal tissues. Also, differences exist in the Raman spectral profiles of normal and FCD.

Electron beam induced fluorescence measurements of the degree of hydrogen dissociation in hydrogen plasmas

NARCIS (Netherlands)

Smit, C.; Brussaard, G.J.H.; de Beer, E.C.M.; Schram, D.C.; Sanden, van de M.C.M.

2004-01-01

The degree of dissociation of hydrogen in a hydrogen plasma has been measured using electron beam induced fluorescence. A 20 kV, 1 mA electron beam excites both the ground state H atom and H2 molecule into atomic hydrogen in an excited state. From the resulting fluorescence the degree of

Chlorophyll fluorescence lifetime imaging provides new insight into the chlorosis induced by plant virus infection.

Science.gov (United States)

Lei, Rong; Jiang, Hongshan; Hu, Fan; Yan, Jin; Zhu, Shuifang

2017-02-01

Leaf chlorosis induced by plant virus infection has a short fluorescence lifetime, which reflects damaged photosynthetic complexes and degraded chloroplasts. Plant viruses often induce chlorosis and necrosis, which are intimately related to photosynthetic functions. Chlorophyll fluorescence lifetime measurement is a valuable noninvasive tool for analyzing photosynthetic processes and is a sensitive indicator of the environment surrounding the fluorescent molecules. In this study, our central goal was to explore the effect of viral infection on photosynthesis by employing chlorophyll fluorescence lifetime imaging (FLIM), steady-state fluorescence, non-photochemical quenching (NPQ), transmission electron microscopy (TEM), and pigment analysis. The data indicated that the chlorophyll fluorescence lifetime of chlorotic leaves was significantly shorter than that of healthy control leaves, and the fitted short lifetime component of chlorophyll fluorescence of chlorotic leaves was dominant. This dominant short lifetime component may result from damage to the structure of thylakoid, which was confirmed by TEM. The NPQ value of chlorotic leaves was slightly higher than that of healthy green leaves, which can be explained by increased neoxanthin, lutein and violaxanthin content relative to chlorophyll a. The difference in NPQ is slight, but FLIM can provide simple and direct characterization of PSII structure and photosynthetic function. Therefore, this technique shows great potential as a simple and rapid method for studying mechanisms of plant virus infection.

Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy

OpenAIRE

Hovhannisyan, V.; Guo, H. W.; Hovhannisyan, A.; Ghukasyan, V.; Buryakina, T.; Chen, Y. F.; Dong, C. Y.

2014-01-01

Collagen is the main structural protein and the key determinant of mechanical and functional properties of tissues and organs. Proper balance between synthesis and degradation of collagen molecules is critical for maintaining normal physiological functions. In addition, collagen influences tumor development and drug delivery, which makes it a potential cancer therapy target. Using second harmonic generation, two-photon excited fluorescence microscopy, and spectrofluorimetry, we show that the ...

Separation and identification of DNA-carcinogen adduct conformers by polyacrylamide gel electrophoresis with laser-induced fluorescence detection

Energy Technology Data Exchange (ETDEWEB)

Marsch, G.A.; Jankowiak, R.; Farhat, J.H.; Small, G.J. (Ames Lab., IA (United States) Iowa State Univ., Ames (United States))

1992-12-01

The authors have developed a separation protocol utilizing high-resolution polyacrylamide gel electrophoresis (PAGE) to isolate stable anti-benzo[a]pyrene diol epoxide adducts of oligodeoxynucleotides. Both enantiomers produced multiple adduct species. The distribution of adduct types could be quantitated by densitometry of autoradiograms or Cerenkov counting of eluted oligomers modified by anti-BPDE isomers. Laser-induced fluorescence (LIF) spectra of eluted adducts at 4.2 K (fluorescence line-narrowing spectroscopy) and 77 K revealed that bands corresponded to pure conformers of pyrene chromophore. Carcinogen-modified oligodeoxynucleotides were single-stranded, but there were often considerable stacking interactions between the pyrenyl residues and the oligonucleotide bases, indicating that electrophoresed oligomers were single-stranded but in a native, versus random-coil conformation. The ability to identify and quantitate adducts by PAGE-LIF, coupled with the high resolution and sensitivity of both techniques, makes PAGE and LIF in tandem a potentially powerful tool in the study of chemical carcinogenesis or other ligand-DNA interactions. 43 refs., 7 figs., 1 tab.

Detecting long-term low-irradiance stress and water stress of trees with laser-induced fluorescence measurements

International Nuclear Information System (INIS)

Sagawa, M.; Kurata, K.; Takahashi, K.; Mineuchi, K.

2001-01-01

The objective of this study was to find simple and objective methods of diagnosing the ailments of trees in indoor spaces, such as atriums. In this study, two simple diagnostics were compared. One was the analysis of the laser-induced fluorescence spectra of leaves and the other was the analysis of the laser-induced chlorophyll-fluorescence induction kinetics (Kautsky effect). In the latter analysis, second time derivatives of the induction-kinetics curves were used. Cinnamomum camphora and Quercus myrsinifolia grown under different light conditions and Cinnamomum camphora under water stress were used in the experiments. The effects of low irradiance were detected in both the induction kinetics and the spectra; however, the effects of water stress were detected in the induction kinetics only. These results indicate the possibility of utilizing laser-induced-fluorescence induction-kinetics for diagnosing the ailments of trees. (author)

Laser induced uranium fluorescence as an analytical method

International Nuclear Information System (INIS)

Krutman, I.

1985-01-01

A laser induced fluorescence system was developed to measure uranium trace level amounts in aqueous solution with reliable and simple materials and electronics. A nitrogen pulsed laser was built with the storage energy capacitor directly coupled to laser tube electrodes as a transmission line device. This laser operated at 3Hz repetition rate with peak intensity around 21 Kw and temporal width of 4.5 x 10 -9 s. A sample compartment made of rigid PVC and a photomultiplier housing of aluminium were constructed and assembled forming a single integrated device. As a result of this prototype system we made several analytical measurements with U dissolved in nitric acid to obtain a calibration curve. We obtained a straight line from a plot of U concentration versus fluorescence intensity fitted by a least square method that produced a regression coefficient of 0.994. The lower limit of U determination was 30 ppb -+ 3.5%. (Author) [pt

Determination of absolute Ba densities during dimming operation of fluorescent lamps by laser-induced fluorescence measurements

International Nuclear Information System (INIS)

Hadrath, S; Beck, M; Garner, R C; Lieder, G; Ehlbeck, J

2007-01-01

Investigations of fluorescent lamps (FL) are often focused on the electrodes, since the lifetime of the lamps is typically limited by the electrode lifetime and durability. During steady state operation, the work function lowering emitter material, in particular, barium, is lost. Greater barium losses occur under dimming conditions, in which reduced discharge currents lead to increased cathode falls, the result of the otherwise diminished heating of the electrode by the bombarding plasma ions. In this work the barium density near the electrodes of (FL), operating in high frequency dimming mode is investigated using the high-sensitivity method of laser-induced fluorescence. From these measurements we infer barium loss for a range of discharge currents and auxiliary coil heating currents. We show that the Ba loss can very easily be reduced by moderate auxiliary coil heating

Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography.

Science.gov (United States)

Maia, Ana Marly Araújo; de Freitas, Anderson Zanardi; de L Campello, Sergio; Gomes, Anderson Stevens Leônidas; Karlsson, Lena

2016-06-01

An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light-Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System. QLF versus OCT imaging of enamel caries: a photonics assessment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Monitoring the corrosion process of Al alloys through pH induced fluorescence

International Nuclear Information System (INIS)

Pidaparti, R M; Neblett, E B; Miller, S A; Alvarez, J C

2008-01-01

A sensing and monitoring set-up based on electrochemical pH induced fluorescence to systematically control the electrochemical corrosion process has been developed for possible applications in the field of localized corrosion. The sensing and monitoring concept is based on exposing the corroding metal surface to solutions that contain selected redox chemicals which will react in local regions where anodic or cathodic polarizations occur. Redox couples that produce or consume protons in their electrochemical reactions were used so that local pH gradients can indicate electrochemical activity by inducing fluorescence in dyes. This approach has been applied to study the corrosion initiation in aircraft aluminum metal 2024-T3 in a controlled electrochemical cell. Preliminary results obtained suggest that monitoring of localized corrosion based on pH can be achieved for field applications

Remote imaging laser-induced breakdown spectroscopy and laser-induced fluorescence spectroscopy using nanosecond pulses from a mobile lidar system.

Science.gov (United States)

Grönlund, Rasmus; Lundqvist, Mats; Svanberg, Sune

2006-08-01

A mobile lidar system was used in remote imaging laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF) experiments. Also, computer-controlled remote ablation of a chosen area was demonstrated, relevant to cleaning of cultural heritage items. Nanosecond frequency-tripled Nd:YAG laser pulses at 355 nm were employed in experiments with a stand-off distance of 60 meters using pulse energies of up to 170 mJ. By coaxial transmission and common folding of the transmission and reception optical paths using a large computer-controlled mirror, full elemental imaging capability was achieved on composite targets. Different spectral identification algorithms were compared in producing thematic data based on plasma or fluorescence light.

Proteome stability analysis of snap frozen, RNAlater preserved, and formalin-fixed paraffin-embedded human colon mucosal biopsies

DEFF Research Database (Denmark)

Bjerg Bennike, Tue; Kastaniegaard, Kenneth; Padurariu, Simona

2016-01-01

Large repositories of well characterized RNAlater preserved samples and formalin-fixed, paraffin-embedded samples have been generated worldwide. However, the impact on the proteome of the preservation methods remain poorly described. Therefore, we analyzed the impact on the proteome of preserving...... samples in RNAlater, and by formalin-fixation, paraffin-embedding on human soft tissue, using directly frozen samples as a control ("Comparing the proteome of snap frozen, RNAlater preserved, and formalin-fixed paraffin-embedded human tissue samples" [1]). We here report the data from the analysis...

A Method to Reconstruct the Solar-Induced Canopy Fluorescence Spectrum from Hyperspectral Measurements

Directory of Open Access Journals (Sweden)

Feng Zhao

2014-10-01

Full Text Available A method for canopy Fluorescence Spectrum Reconstruction (FSR is proposed in this study, which can be used to retrieve the solar-induced canopy fluorescence spectrum over the whole chlorophyll fluorescence emission region from 640–850 nm. Firstly, the radiance of the solar-induced chlorophyll fluorescence (Fs at five absorption lines of the solar spectrum was retrieved by a Spectral Fitting Method (SFM. The Singular Vector Decomposition (SVD technique was then used to extract three basis spectra from a training dataset simulated by the model SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes. Finally, these basis spectra were linearly combined to reconstruct the Fs spectrum, and the coefficients of them were determined by Weighted Linear Least Squares (WLLS fitting with the five retrieved Fs values. Results for simulated datasets indicate that the FSR method could accurately reconstruct the Fs spectra from hyperspectral measurements acquired by instruments of high Spectral Resolution (SR and Signal to Noise Ratio (SNR. The FSR method was also applied to an experimental dataset acquired in a diurnal experiment. The diurnal change of the reconstructed Fs spectra shows that the Fs radiance around noon was higher than that in the morning and afternoon, which is consistent with former studies. Finally, the potential and limitations of this method are discussed.

Design of remote laser-induced fluorescence system's acquisition circuit

Science.gov (United States)

Wang, Guoqing; Lou, Yue; Wang, Ran; Yan, Debao; Li, Xin; Zhao, Xin; Chen, Dong; Zhao, Qi

2017-10-01

Laser-induced fluorescence system(LIfS) has been found its significant application in identifying one kind of substance from another by its properties even it's thimbleful, and becomes useful in plenty of fields. Many superior works have reported LIfS' theoretical analysis , designs and uses. However, the usual LIPS is always constructed in labs to detect matter quite closely, for the system using low-power laser as excitation source and charge coupled device (CCD) as detector. Promoting the detectivity of LIfS is of much concern to spread its application. Here, we take a high-energy narrow-pulse laser instead of commonly used continuous wave laser to operate sample, thus we can get strong fluorescent. Besides, photomultiplier (PMT) with high sensitivity is adopted in our system to detect extremely weak fluorescence after a long flight time from the sample to the detector. Another advantage in our system, as the fluorescence collected into spectroscopy, multiple wavelengths of light can be converted to the corresponding electrical signals with the linear array multichannel PMT. Therefore, at the cost of high-powered incentive and high-sensitive detector, a remote LIFS is get. In order to run this system, it is of importance to turn light signal to digital signal which can be processed by computer. The pulse width of fluorescence is deeply associated with excitation laser, at the nanosecond(ns) level, which has a high demand for acquisition circuit. We design an acquisition circuit including, I/V conversion circuit, amplifying circuit and peak-holding circuit. The simulation of circuit shows that peak-holding circuit can be one effective approach to reducing difficulty of acquisition circuit.

Quantitative liquid and vapor distribution measurements in evaporating fuel sprays using laser-induced exciplex fluorescence

International Nuclear Information System (INIS)

Fansler, Todd D; Drake, Michael C; Gajdeczko, Boguslaw; Düwel, Isabell; Koban, Wieland; Zimmermann, Frank P; Schulz, Christof

2009-01-01

Fully quantitative two-dimensional measurements of liquid- and vapor-phase fuel distributions (mass per unit volume) from high-pressure direct-injection gasoline injectors are reported for conditions of both slow and rapid vaporization in a heated, high-pressure spray chamber. The measurements employ the coevaporative gasoline-like fluorobenzene (FB)/diethylmethylamine (DEMA)/hexane exciplex tracer/fuel system. In contrast to most previous laser-induced exciplex-fluorescence (LIEF) experiments, the quantitative results here include regions in which liquid and vapor fuel coexist (e.g. near the injector exit). A unique aspect is evaluation of both vapor- and liquid-phase distributions at varying temperature and pressure using only in situ vapor-phase fluorescence calibration measurements at room temperature and atmospheric pressure. This approach draws on recent extensive measurements of the temperature-dependent spectroscopic properties of the FB–DEMA exciplex system, in particular on knowledge of the quantum efficiencies of the vapor-phase and liquid-phase (exciplex) fluorescence. In addition to procedures necessary for quantitative measurements, we discuss corrections for liquid–vapor crosstalk (liquid fluorescence that overlaps the vapor-fluorescence bandpass), the unknown local temperature due to vaporization-induced cooling, and laser-sheet attenuation by scattering and absorption

Laser-Induced Photofragmentation Fluorescence Imaging of Alkali Compounds in Flames.

Science.gov (United States)

Leffler, Tomas; Brackmann, Christian; Aldén, Marcus; Li, Zhongshan

2017-06-01

Laser-induced photofragmentation fluorescence has been investigated for the imaging of alkali compounds in premixed laminar methane-air flames. An ArF excimer laser, providing pulses of wavelength 193 nm, was used to photodissociate KCl, KOH, and NaCl molecules in the post-flame region and fluorescence from the excited atomic alkali fragment was detected. Fluorescence emission spectra showed distinct lines of the alkali atoms allowing for efficient background filtering. Temperature data from Rayleigh scattering measurements together with simulations of potassium chemistry presented in literature allowed for conclusions on the relative contributions of potassium species KOH and KCl to the detected signal. Experimental approaches for separate measurements of these components are discussed. Signal power dependence and calculated fractions of dissociated molecules indicate the saturation of the photolysis process, independent on absorption cross-section, under the experimental conditions. Quantitative KCl concentrations up to 30 parts per million (ppm) were evaluated from the fluorescence data and showed good agreement with results from ultraviolet absorption measurements. Detection limits for KCl photofragmentation fluorescence imaging of 0.5 and 1.0 ppm were determined for averaged and single-shot data, respectively. Moreover, simultaneous imaging of KCl and NaCl was demonstrated using a stereoscope with filters. The results indicate that the photofragmentation method can be employed for detailed studies of alkali chemistry in laboratory flames for validation of chemical kinetic mechanisms crucial for efficient biomass fuel utilization.

Laser-induced fluorescence imaging of acetone inside evaporating and burning fuel droplets

Science.gov (United States)

Shringi, D. S.; Shaw, B. D.; Dwyer, H. A.

2009-01-01

Laser-induced fluorescence was used to visualize acetone fields inside individual droplets of pure acetone as well as droplets composed of methanol or 1-propanol initially mixed with acetone. Droplets were supported on a horizontal wire and two vaporization conditions were investigated: (1) slow evaporation in room air and (2) droplet combustion, which leads to substantially faster droplet surface regression rates. Acetone was preferentially gasified, causing its concentration in droplets to drop in time with resultant decreases in acetone fluorescence intensities. Slowly vaporizing droplets did not exhibit large spatial variations of fluorescence within droplets, indicating that these droplets were relatively well mixed. Ignition of droplets led to significant variations in fluorescence intensities within droplets, indicating that these droplets were not well mixed. Ignited droplets composed of mixtures of 1-propanol and acetone showed large time-varying changes in shapes for higher acetone concentrations, suggesting that bubble formation was occurring in these droplets.

Quantitative nitric oxide measurements by means of laser-induced fluorescence in a heavy-duty Diesel engine

NARCIS (Netherlands)

Verbiezen, K.; Vliet, van A.P.; Klein-Douwel, R.J.H.; Ganippa, L.C.; Bougie, H.J.T.; Meerts, W.L.; Dam, N.J.; Meulen, ter J.J.

2005-01-01

Quantitative in-cylinder laser-induced fluorescence measurements ofnitric oxide in a heavy-duty Diesel engine are presented. Special attention is paid to experimental techniques to assess the attenuation of the laser beam and the fluorescence signal by the cylinder contents.This attenuation can be

Sun-induced fluorescence - a new probe of photosynthesis: First maps from the imaging spectrometer HyPlant

Czech Academy of Sciences Publication Activity Database

Rascher, U.; Alonso, A.; Burkart, A.; Cilia, C.; Cogliati, S.; Colombo, R.; Damm, A.; Drusch, M.; Guanter, L.; Hanuš, Jan; Hyvarinen, T.; Jullita, T.; Jussila, J.; Kataja, K.; Kokkalis, P.; Kraft, S.; Kraska, T.; Matveeva, M.; Moreno, J.; Müller, O.; Panigada, C.; Pikl, Miroslav; Pinto, F.; Prey, L.; Pude, F.; Rossini, M.; Schickling, A.; Schurr, E.; Schüttemeyer, D.; Verrlest, J.; Zemek, František

2015-01-01

Roč. 21, č. 12 (2015), s. 4673-4684 ISSN 1354-1013 Institutional support: RVO:67179843 Keywords : airborne measurements * chlorophyll fluorescence * FLEX * HyPlant * imaging spectroscopy * photosynthesis * remote sensing * sun-induced fluorescence * vegetation monitoring Subject RIV: EH - Ecology, Behaviour Impact factor: 8.444, year: 2015

Laser-induced fluorescence for the detection of esophageal and skin cancer

Science.gov (United States)

Vo-Dinh, Tuan; Panjehpour, Masoud; Overholt, Bergein F.; Julius, Clark E.; Overholt, Suzanne; Phan, Mary N.

2003-07-01

Laser-induced fluorescence (LIF) is used for in-vivo cancer diagnosis of the esophagus and skin cancer. For esophageal measurements a fiberoptic probe inserted through an endoscope was used. Autofluorescence of normal and malignant tissues were measured directly on patient skin without requiring an endoscope. Measurement of the fluorescence signal from the tissue was performed using laser excitation at 410 nm. The methodology was applied to differentiate normal and malignant tumors of the esophagus and malignant skin lesions. The results of this LIF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement in the classification of normal and malignant tumors for the samples investigated.

Experimental Studies of Laser-Induced Fluorescence Spectra of Plants Immunity to the Kind of Ground

Directory of Open Access Journals (Sweden)

Yu. V. Fedotov

2015-01-01

Full Text Available Various external factors (pollutants available in the soil, a lack or insufficient amount of water and nutrients, etc. lead to stressful conditions of plants and impossibility of their normal development. At the early stages it is difficult to identify visually the stressful situations of plants. Therefore development of methods and devices to detect stressful states is important.A method of the laser-induced fluorescence is one of perspective methods for detection of stressful conditions of plants.In spite of quite a great number of work presenting results of the pilot studies of fluorescence spectra of vegetation, there are some important issues, which are unclear.The paper gives results of pilot studies of stability of a spectrum form of the laser-induced fluorescence of plants for different types of soil at the wavelength of excitation fluorescence of 532 nm.Results of processing fluorescence spectra of plants show:- fluorescence spectra of plants grown up under similar conditions have good repeatability of a spectra form for different samples of plants and different measurement time for each type of studied soil. The ratio value R of the fluorescence intensity at the wavelength of 685 nm to the fluorescence intensity at the wavelength of 740 nm has high stability. The standard deviation in sampling of the ratio R of different samples of a plant for one type of soil (for width of spectral ranges of recording fluorescent radiation of 10 nm lies in the range ~ 0.055 - ~ 0.12;- a difference in plant fluorescence spectra between themselves for different types of soil has the same order as a difference in fluorescence spectra of different samples of a plant for one type of soil. Difference in average value of the ratio R for different types of soil lies in the range ~ 0.01 - ~ 0.15.Thus, the value of the ratio R is steady against a type of soil and can be used to control a condition of plants.

Laser-induced fluorescence of metal-atom impurities in a neutral beam

International Nuclear Information System (INIS)

Burrell, C.F.; Pyle, R.V.; Sabetimani, Z.; Schlachter, A.S.

1984-10-01

The need to limit impurities in fusion devices to low levels is well known. We have investigated, by the technique of laser-induced fluorescence, the concentration of heavy-metal atoms in a neutral beam caused by their evaporation from the hot filaments in a conventional high-current multifilament hydrogen-ion source

Measurements of excited-state-to-excited-state transition probabilities and photoionization cross-sections using laser-induced fluorescence and photoionization signals

International Nuclear Information System (INIS)

Shah, M.L.; Sahoo, A.C.; Pulhani, A.K.; Gupta, G.P.; Dikshit, B.; Bhatia, M.S.; Suri, B.M.

2014-01-01

Laser-induced photoionization and fluorescence signals were simultaneously observed in atomic samarium using Nd:YAG-pumped dye lasers. Two-color, three-photon photoionization and two-color fluorescence signals were recorded simultaneously as a function of the second-step laser power for two photoionization pathways. The density matrix formalism has been employed to analyze these signals. Two-color laser-induced fluorescence signal depends on the laser powers used for the first and second-step transitions as well as the first and second-step transition probability whereas two-color, three-photon photoionization signal depends on the third-step transition cross-section at the second-step laser wavelength along with the laser powers and transition probability for the first and second-step transitions. Two-color laser-induced fluorescence was used to measure the second-step transition probability. The second-step transition probability obtained was used to infer the photoionization cross-section. Thus, the methodology combining two-color, three-photon photoionization and two-color fluorescence signals in a single experiment has been established for the first time to measure the second-step transition probability as well as the photoionization cross-section. - Highlights: • Laser-induced photoionization and fluorescence signals have been simultaneously observed. • The density matrix formalism has been employed to analyze these signals. • Two-color laser-induced fluorescence was used to measure the second-step transition probability. • The second-step transition probability obtained was used to infer the photoionization cross-section. • Transition probability and photoionization cross-section have been measured in a single experiment

Laser-Induced Fluorescence Detection in High-Throughput Screening of Heterogeneous Catalysts and Single Cells Analysis

Energy Technology Data Exchange (ETDEWEB)

Su, Hui [Iowa State Univ., Ames, IA (United States)

2001-01-01

Laser-induced fluorescence detection is one of the most sensitive detection techniques and it has found enormous applications in various areas. The purpose of this research was to develop detection approaches based on laser-induced fluorescence detection in two different areas, heterogeneous catalysts screening and single cell study. First, we introduced laser-induced imaging (LIFI) as a high-throughput screening technique for heterogeneous catalysts to explore the use of this high-throughput screening technique in discovery and study of various heterogeneous catalyst systems. This scheme is based on the fact that the creation or the destruction of chemical bonds alters the fluorescence properties of suitably designed molecules. By irradiating the region immediately above the catalytic surface with a laser, the fluorescence intensity of a selected product or reactant can be imaged by a charge-coupled device (CCD) camera to follow the catalytic activity as a function of time and space. By screening the catalytic activity of vanadium pentoxide catalysts in oxidation of naphthalene, we demonstrated LIFI has good detection performance and the spatial and temporal resolution needed for high-throughput screening of heterogeneous catalysts. The sample packing density can reach up to 250 x 250 subunits/cm₂ for 40-μm wells. This experimental set-up also can screen solid catalysts via near infrared thermography detection.

Laser-Induced Fluorescence Detection in High-Throughput Screening of Heterogeneous Catalysts and Single Cells Analysis

International Nuclear Information System (INIS)

Hui Su

2001-01-01

Laser-induced fluorescence detection is one of the most sensitive detection techniques and it has found enormous applications in various areas. The purpose of this research was to develop detection approaches based on laser-induced fluorescence detection in two different areas, heterogeneous catalysts screening and single cell study. First, we introduced laser-induced imaging (LIFI) as a high-throughput screening technique for heterogeneous catalysts to explore the use of this high-throughput screening technique in discovery and study of various heterogeneous catalyst systems. This scheme is based on the fact that the creation or the destruction of chemical bonds alters the fluorescence properties of suitably designed molecules. By irradiating the region immediately above the catalytic surface with a laser, the fluorescence intensity of a selected product or reactant can be imaged by a charge-coupled device (CCD) camera to follow the catalytic activity as a function of time and space. By screening the catalytic activity of vanadium pentoxide catalysts in oxidation of naphthalene, we demonstrated LIFI has good detection performance and the spatial and temporal resolution needed for high-throughput screening of heterogeneous catalysts. The sample packing density can reach up to 250 x 250 subunits/cm(sub 2) for 40-(micro)m wells. This experimental set-up also can screen solid catalysts via near infrared thermography detection

Virus characterization and discovery in formalin-fixed paraffin-embedded tissues

NARCIS (Netherlands)

Bodewes, Rogier; van Run, Peter R W A; Schürch, Anita C; Koopmans, Marion P G; Osterhaus, Albert D M E; Baumgärtner, Wolfgang; Kuiken, Thijs; Smits, Saskia L

2015-01-01

Detection and characterization of novel viruses is hampered frequently by the lack of properly stored materials. Especially for the retrospective identification of viruses responsible for past disease outbreaks, often only formalin-fixed paraffin-embedded (FFPE) tissue samples are available.

Synergism between fentanyl and tramadol in tonic inflammatory pain: the orofacial formalin test.

Science.gov (United States)

Miranda, Hugo F; Noriega, Viviana; Zepeda, Ramiro J; Sierralta, Fernando; Prieto, Juan C

2012-06-01

Opioids have been used for long time to management of pain, the coadministration of two opioids may induce synergism. The present study was conducted to determine the antinociceptive interaction between the dual mechanism of action of tramadol compared to the main of fentanyl antinociception in the orofacial formalin which represents a model of persistent cutaneous nociception in the region innervated by the trigeminal nerve. The i.p. administration of tramadol and fentanyl induced a dose-dependent antinociception with an ED(50) of 2.97 ± 0.32 mg/kg for phase I and 1.79 ± 0.30 mg/kg for phase II and 0.062 ± 0.0040 mg/kg in phase I and 0.041 ± 0.0039 mg/kg in phase II, respectively. The coadministration of fentanyl with tramadol induced synergism in both phases of the test with an interaction index of 0.343 and 0.163 for phase I and phase II, respectively. This finding could be explained by the more complex pharmacology of tramadol compared to fentanyl.

Introducing inducible fluorescent split cholesterol oxidase to mammalian cells.

Science.gov (United States)

Chernov, Konstantin G; Neuvonen, Maarit; Brock, Ivonne; Ikonen, Elina; Verkhusha, Vladislav V

2017-05-26

Cholesterol oxidase (COase) is a bacterial enzyme catalyzing the first step in the biodegradation of cholesterol. COase is an important biotechnological tool for clinical diagnostics and production of steroid drugs and insecticides. It is also used for tracking intracellular cholesterol; however, its utility is limited by the lack of an efficient temporal control of its activity. To overcome this we have developed a regulatable fragment complementation system for COase cloned from Chromobacterium sp. The enzyme was split into two moieties that were fused to FKBP (FK506-binding protein) and FRB (rapamycin-binding domain) pair and split GFP fragments. The addition of rapamycin reconstituted a fluorescent enzyme, termed split GFP-COase, the fluorescence level of which correlated with its oxidation activity. A rapid decrease of cellular cholesterol induced by intracellular expression of the split GFP-COase promoted the dissociation of a cholesterol biosensor D4H from the plasma membrane. The process was reversible as upon rapamycin removal, the split GFP-COase fluorescence was lost, and cellular cholesterol levels returned to normal. These data demonstrate that the split GFP-COase provides a novel tool to manipulate cholesterol in mammalian cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Sample analysis using gamma ray induced fluorescent X-ray emission

Energy Technology Data Exchange (ETDEWEB)

Sood, B S; Allawadhi, K L; Gandhi, R; Batra, O P; Singh, N [Punjabi Univ., Patiala (India). Nuclear Science Labs.

1983-01-01

A non-destructive method for the analysis of materials using gamma ray-induced fluorescent x-ray emission has been developed. In this method, special preparation of very thin samples in which the absorption of the incident gamma rays and the emitted fluorescent x-rays is negligible, is not needed, and the absorption correction is determined experimentally. A suitable choice of the incident gamma ray energies is made to minimise enhancement effects through selective photoionization of the elements in the sample. The method is applied to the analysis of a typical sample of the soldering material using 279 keV and 59.5 keV gamma rays from /sup 203/Hg and /sup 241/Am radioactive sources respectively. The results of the analysis are found to agree well with those obtained from the chemical analysis.

Near-Infrared Fluorescent Nanoprobes for Revealing the Role of Dopamine in Drug Addiction.

Science.gov (United States)

Feng, Peijian; Chen, Yulei; Zhang, Lei; Qian, Cheng-Gen; Xiao, Xuanzhong; Han, Xu; Shen, Qun-Dong

2018-02-07

Brain imaging techniques enable visualizing the activity of central nervous system without invasive neurosurgery. Dopamine is an important neurotransmitter. Its fluctuation in brain leads to a wide range of diseases and disorders, like drug addiction, depression, and Parkinson's disease. We designed near-infrared fluorescence dopamine-responsive nanoprobes (DRNs) for brain activity imaging during drug abuse and addiction process. On the basis of light-induced electron transfer between DRNs and dopamine and molecular wire effect of the DRNs, we can track the dynamical change of the neurotransmitter level in the physiological environment and the releasing of the neurotransmitter in living dopaminergic neurons in response to nicotine stimulation. The functional near-infrared fluorescence imaging can dynamically track the dopamine level in the mice midbrain under normal or drug-activated condition and evaluate the long-term effect of addictive substances to the brain. This strategy has the potential for studying neural activity under physiological condition.

Pathological diagnosis of bladder cancer by image analysis of hypericin induced fluorescence cystoscopic images

Science.gov (United States)

Kah, James C. Y.; Olivo, Malini C.; Lau, Weber K. O.; Sheppard, Colin J. R.

2005-08-01

Photodynamic diagnosis of bladder carcinoma based on hypericin fluorescence cystoscopy has shown to have a higher degree of sensitivity for the detection of flat bladder carcinoma compared to white light cystoscopy. The potential of the photosensitizer hypericin-induced fluorescence in performing non-invasive optical biopsy to grade bladder cancer in vivo using fluorescence cystoscopic image analysis without surgical resection for tissue biopsy is investigated in this study. The correlation between tissue fluorescence and histopathology of diseased tissue was explored and a diagnostic algorithm based on fluorescence image analysis was developed to classify the bladder cancer without surgical resection for tissue biopsy. Preliminary results suggest a correlation between tissue fluorescence and bladder cancer grade. By combining both the red-to-blue and red-to-green intensity ratios into a 2D scatter plot yields an average sensitivity and specificity of around 70% and 85% respectively for pathological cancer grading of the three different grades of bladder cancer. Therefore, the diagnostic algorithm based on colorimetric intensity ratio analysis of hypericin fluorescence cystoscopic images developed in this preliminary study shows promising potential to optically diagnose and grade bladder cancer in vivo.

A method for detection of hydroxyl radicals in the vicinity of biomolecules using radiation-induced fluorescence of coumarin

International Nuclear Information System (INIS)

Makrigiorgos, G.M.; Baranowska-Kortylewicz, J.; Bump, E.; Sahu, S.K.; Berman, R.M.; Kassis, A.I.

1993-01-01

A novel method is described to quantitate radiation-induced hydroxyl radicals in the vicinity of biomolecules in aqueous solutions. Coumarin-3-carboxylic acid (CCA) is a non-fluorescent molecule that, upon interaction with radiation in aqueous solution, produces fluorescent products. CCA was derivatized to its succinimidyl ester (SECCA) and coupled to free primary amines of albumin, avidin, histone-H1, polylysine, and an oligonucleotide. When SECCA-biomolecule conjugates were irradiated, the relationship between induced fluorescence and dose was linear in the dose range examined (0.01-10 Gy). The data indicate that the induction of fluorescence on SECCA-biomolecule conjugates records specifically the presence of the hydroxyl radical in the immediate vicinity of the irradiated biomolecule. The method is rapid and sensitive, uses standard instrumentation, and the sample remains available for further studies. (Author)

3D ion velocity distribution function measurement in an electric thruster using laser induced fluorescence tomography

Science.gov (United States)

Elias, P. Q.; Jarrige, J.; Cucchetti, E.; Cannat, F.; Packan, D.

2017-09-01

Measuring the full ion velocity distribution function (IVDF) by non-intrusive techniques can improve our understanding of the ionization processes and beam dynamics at work in electric thrusters. In this paper, a Laser-Induced Fluorescence (LIF) tomographic reconstruction technique is applied to the measurement of the IVDF in the plume of a miniature Hall effect thruster. A setup is developed to move the laser axis along two rotation axes around the measurement volume. The fluorescence spectra taken from different viewing angles are combined using a tomographic reconstruction algorithm to build the complete 3D (in phase space) time-averaged distribution function. For the first time, this technique is used in the plume of a miniature Hall effect thruster to measure the full distribution function of the xenon ions. Two examples of reconstructions are provided, in front of the thruster nose-cone and in front of the anode channel. The reconstruction reveals the features of the ion beam, in particular on the thruster axis where a toroidal distribution function is observed. These findings are consistent with the thruster shape and operation. This technique, which can be used with other LIF schemes, could be helpful in revealing the details of the ion production regions and the beam dynamics. Using a more powerful laser source, the current implementation of the technique could be improved to reduce the measurement time and also to reconstruct the temporal evolution of the distribution function.

Pressure broadening of atomic oxygen two-photon absorption laser induced fluorescence

NARCIS (Netherlands)

Marinov, D.; Drag, C.; Blondel, C.; Guaitella, O.; Golda, J.; Klarenaar, B.L.M.; Engeln, R.A.H.; Schulz-von der Gathen, V.; Booth, J.-P.

2016-01-01

Atomic oxygen, considered to be a determining reactant in plasma applications at ambient pressure, is routinely detected by two-photon absorption laser induced fluorescence (TALIF). Here, pressure broadening of the (2p 4 3 P 2  →  3p 3 P J=0,1,2) two-photon transition in oxygen atoms was

Study the effect of insecticide dimethoate on photosynthetic pigments and photosynthetic activity of pigeon pea: Laser-induced chlorophyll fluorescence spectroscopy.

Science.gov (United States)

Pandey, Jitendra Kumar; Dubey, Gunjan; Gopal, R

2015-10-01

Pigeon pea is one of the most important legume crops in India and dimethoate is a widely used insecticide in various crop plants. We studied the effect of dimethoate on growth and photosynthetic activity of pigeon pea plants over a short and long term exposure. Plant growth parameters, photosynthetic pigment content and chlorophyll fluorescence response of pigeon pea (Cajanus cajan L.) plants treated with various concentrations of the insecticide dimethoate (10, 20, 40 and 80 ppm) have been compared for 30 days at regular intervals of 10 days each. Laser induced chlorophyll fluorescence spectra and fluorescence-induction kinetics (FIK) curve of dimethoate treated pigeon pea plants were recorded after 10, 20 and 30 days of treatment. Fluorescence intensity ratio at the two fluorescence maxima (F685/F730) was calculated by evaluating curve-fitted parameters. The variable chlorophyll fluorescence decrease ratio (Rfd) was determined from the FIK curves. Our study revealed that after 10 days of treatment, 10 ppm of dimethoate showed stimulatory response whereas 20, 40 and 80 ppm of dimethoate showed inhibitory response for growth and photosynthetic activity of pigeon pea plants, but after 20 and 30 days of treatment all the tested concentrations of dimethoate became inhibitory. This study clearly shows that dimethoate is highly toxic to the pigeon pea plant, even at very low concentration (10 ppm), if used for a prolonged duration. Our study may thus be helpful in determining the optimal dose of dimethoate in agricultural practices. Copyright © 2014 Elsevier B.V. All rights reserved.

Time-resolved laser-induced fluorescence in the nuclear fuel cycle

International Nuclear Information System (INIS)

Moulin, C.; Decambox, P.; Mauchien, P.; Petit, A.

1995-01-01

Time-Resolved Laser-Induced Fluorescence (TRLIF) is a very sensitive and selective method that has been used for actinides and lanthanides analysis in the nuclear fuel cycle. This technique has been used in different fields such as in geology, in the Purex process, in the environment, in the medical and in waste storage assessment. Spectroscopic data, limits of detection and results obtained in previously quoted fields are presented. (author)

Proton induced X-Ray fluorescence study as a tool trace element analysis

International Nuclear Information System (INIS)

El-Kady, Ahmed A.

1978-01-01

Usefulness and limitations of trace elemental analysis by high energy charged particles and photon induced X-ray have been discussed. Comparison with the well established neutron activation analysis technique is also given. Back-ground radiation due to bremsstrahlung from secondary electrons and due to charged particle bremsstrahlung have been reviewed for different projectiles. The sensitivity of elemental analysis by proton induced X-ray fluorescence have been examined by measuring the characteristic X-ray emission cross section for K and L transitions of many elements and for different proton energies and compared with theroretical values. The discussion given in this report show that with suitable proton generator and a high resolution X-ray detector, proton X-ray fluorescence technique is capable of analyzing many elements simultaneously at the part per million level and offers a rapid and reliable method for trace element analysis. Data on water, blood and tissue samples given in this report are few examples of many possible applications

Quantitative analysis of essential oils of Thymus daenensis using laser-induced fluorescence and Raman spectroscopy.

Science.gov (United States)

Khoshroo, H; Khadem, H; Bahreini, M; Tavassoli, S H; Hadian, J

2015-11-10

Laser-induced fluorescence and Raman spectroscopy are used for the investigation of different genotypes of Thymus daenensis native to the Ilam province of Iran. Different genotypes of T. daenensis essential oils, labeled T1 through T7, possess slight differences with regard to the composition of the thymol. The gas chromatography-mass spectrometry (GC-MS) method is performed to determine the concentration of each constituent as a reference method. The Raman spectra of different concentrations of pure thymol dissolved in hexane as standard samples are obtained via a laboratory prototype Raman spectroscopy setup for the calculation of the calibration curve. The regression coefficient and limit of detection are calculated. The possibility of the differentiation of different genotypes of T. daenensis is also examined by laser-induced fluorescence spectroscopy, although we do not know the exact amounts of their components. All the fluorescence spectral information is used jointly by cluster analysis to differentiate between 7 genotypes. Our results demonstrate the acceptable precision of Raman spectroscopy with GC-MS and corroborate the capacity of Raman spectroscopy in applications in the quantitative analysis field. Furthermore, the cluster analysis results show that laser-induced fluorescence spectroscopy is an acceptable technique for the rapid classification of different genotypes of T. daenensis without having any previous information of their exact amount of constituents. So, the ability to rapidly and nondestructively differentiate between genotypes makes it possible to efficiently select high-quality herbs from many samples.

Use of quantitative light-induced fluorescence to monitor tooth whitening

Science.gov (United States)

Amaechi, Bennett T.; Higham, Susan M.

2001-04-01

The changing of tooth shade by whitening agents occurs gradually. Apart from being subjective and affected by the conditions of the surroundings, visual observation cannot detect a very slight change in tooth color. An electronic method, which can communicate the color change quantitatively, would be more reliable. Quantitative Light- induced Fluorescence (QLF) was developed to detect and assess dental caries based on the phenomenon of change of autofluorescence of a tooth by demineralization. However, stains on the tooth surface exhibit the same phenomenon, and therefore QLF can be used to measure the percentage fluorescence change of stained enamel with respect to surrounding unstained enamel. The present study described a technique of assessing the effect of a tooth-whitening agent using QLF. This was demonstrated in two experiments in which either wholly or partially stained teeth were whitened by intermittent immersion in sodium hypochlorite. Following each immersion, the integrated fluorescence change due to the stain was quantified using QLF. In either situation, the value of (Delta) Q decreased linearly as the tooth regained its natural shade. It was concluded that gradual changing of the shade of discolored teeth by a whitening agent could be quantified using QLF.

Capillary electrophoresis hyphenated with UV-native-laser induced fluorescence detection (CE/UV-native-LIF).

Science.gov (United States)

Couderc, François; Ong-Meang, Varravaddheay; Poinsot, Véréna

2017-01-01

Native laser-induced fluorescence using UV lasers associated to CE offers now a large related literature, for now 30 years. The main works have been performed using very expensive Ar-ion lasers emitting at 257 and 275 nm. They are not affordable for routine analyses, but have numerous applications such as protein, catecholamine, and indolamine analysis. Some other lasers such as HeCd 325 nm have been used but only for few applications. Diode lasers, emitting at 266 nm, cheaper, are extensively used for the same topics, even if the obtained sensitivity is lower than the one observed using the costly UV-Ar-ion lasers. This review presents various CE or microchips applications and different UV lasers used for the excitation of native fluorescence. We showed that CE/Native UV laser induced fluorescence detection is very sensitive for detection as well as small aromatic biomolecules than proteins containing Trp and Tyr amino acids. Moreover, it is a simple way to analyze biomolecules without derivatization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Changes of the laser-induced blue, green and red fluorescence signatures during greening of etiolated leaves of wheat

International Nuclear Information System (INIS)

Stober, F.; Lichtenthaler, H.K.

1992-01-01

The UV-laser-induced blue, green and red fluorescence-emission spectra were used to characterize the pigment status of etiolated leaves of wheat (Triticum aestivum L.) during a 48 h greening period under white light conditions. Upon UV-light excitation (337 nm) leaves not only show a fluorescence emission in the red spectral region between 650 and 800nm (chlorophyll fluorescence with maxima near 690nm and 735 nm), but also in the blue and green regions between 400 to 570 nm with maxima or shoulders near 450 nm (blue) and 530 nm (green). During greening of etiolated leaves the chlorophyll-fluorescence ratio F690/F735 strongly correlated with the total chlorophyll content and the ratio of the chlorophylls to the carotenoids (a+b/x+c). The ratio of the blue to the green fluorescence F450/F530 was also correlated with the total chlorophyll content and the ratio of chlorophylls to total carotenoids (a+b/x+c). Consequently, there also existed a correlation between the chlorophyll-fluorescence ratio F690/F735 and the ratio of the blue to green fluorescence F450/F530. In contrast, the ratios of the blue to red fluorescences F450/F690 and F450/F735 did not show clear relations to the pigment content of the investigated plants. The particular shape of the UV-laser-induced-fluorescence emission spectra of wheat leaves as well as the dependencies of the fluorescence ratios on the pigment content are due to a partial and differential reabsorption of the emitted fluorescences by the photosynthetic pigments

Tunneling induced dark states and the controllable resonance fluorescence spectrum in quantum dot molecules

International Nuclear Information System (INIS)

Tian, Si-Cong; Tong, Cun-Zhu; Ning, Yong-Qiang; Qin, Li; Liu, Yun; Wan, Ren-Gang

2014-01-01

Optical spectroscopy, a powerful tool for probing and manipulating quantum dots (QDs), has been used to investigate the resonance fluorescence spectrum from linear triple quantum dot molecules controlled by tunneling, using atomic physics methods. Interesting features such as quenching and narrowing of the fluorescence are observed. In such molecules the tunneling between the quantum dots can also induce a dark state. The results are explained by the transition properties of the dressed states generated by the coupling of the laser and the tunneling. Unlike the atomic system, in such quantum dot molecules quantum coherence can be induced using tunneling, requiring no coupling lasers, which will allow tunneling controllable quantum dot molecules to be applied to quantum optics and photonics. (paper)

A fluorescence-coupled assay for gamma aminobutyric acid (GABA reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer.

Directory of Open Access Journals (Sweden)

Joseph E Ippolito

Full Text Available Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA have been implicated in the pathogenesis of high grade neuroendocrine (NE neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1, was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.

Time-resolved spectroscopic imaging reveals the fundamentals of cellular NADH fluorescence.

Science.gov (United States)

Li, Dong; Zheng, Wei; Qu, Jianan Y

2008-10-15

A time-resolved spectroscopic imaging system is built to study the fluorescence characteristics of nicotinamide adenine dinucleotide (NADH), an important metabolic coenzyme and endogenous fluorophore in cells. The system provides a unique approach to measure fluorescence signals in different cellular organelles and cytoplasm. The ratios of free over protein-bound NADH signals in cytosol and nucleus are slightly higher than those in mitochondria. The mitochondrial fluorescence contributes about 70% of overall cellular fluorescence and is not a completely dominant signal. Furthermore, NADH signals in mitochondria, cytosol, and the nucleus respond to the changes of cellular activity differently, suggesting that cytosolic and nuclear fluorescence may complicate the well-known relationship between mitochondrial fluorescence and cellular metabolism.

Simultaneous detection of ultraviolet B-induced DNA damage using capillary electrophoresis with laser-induced fluorescence.

Science.gov (United States)

Guthrie, Jeffrey W; Limmer, Robert T; Brooks, Eric A; Wisnewski, Chelsea C; Loggins-Davis, Nnekia D; Bouzid, Abderraouf

2015-01-01

An immunoassay based on CE-LIF was developed for the simultaneous detection of cyclobutane pyrimidine dimers (CPDs) and pyrimidine 6-4 pyrimidone photoproducts (6-4PPs) in genomic DNA irradiated with UVB or natural sunlight. Human cells were first exposed to varying amounts of UVB or natural sunlight to induce DNA damage. Genomic DNA was extracted and incubated with anti-CPD and anti-6-4PP primary antibodies attached to secondary antibodies with a fluorescent quantum dot (QD) reporter that emitted either red or yellow fluorescence. CE was used to separate the unbound antibodies from those bound to the photoproducts, and LIF with appropriate optical filters was used to separate the fluorescence signals from each QD to individual photomultiplier tubes for simultaneous photoproduct detection. Using this strategy, photoproducts were detected from ∼6 ng (200 ng μL(-1)) of DNA under a low UVB fluence of 65 J m(-2) for CPDs or 195 J m(-2) for 6-4PPs. This assay was also the first to demonstrate the detection of CPDs in human cells after only 15 min of irradiation under natural sunlight. Copyright © 2014 Elsevier B.V. All rights reserved.

Formalin treatments pass new tests. Additional notes on the control of ecto-parasitic protozoa

Science.gov (United States)

1940-01-01

After the completion of the eхреriments reported recently, in which the efficacy of formalin in controlling infections of Gostia mecatrix was demonstrated, the author was afforded an opportunity to test the value of formalin solutions in combatting established mixed infections of (Gyrodactylus, Tricbodina, Cyclochaeta) and a stalked protozoan on rainbow trout fingerlings. This opportunity was provided through the courtesy and cooperation of Clarence F. Pautzke, Chief Biologist for the Washington State Game Department, and Lee Walters, Superintendent of the Washington State Hatchery at Seward Park, Seattle.

Intramolecular ex vivo Fluorescence Resonance Energy Transfer (FRET of Dihydropyridine Receptor (DHPR β1a Subunit Reveals Conformational Change Induced by RYR1 in Mouse Skeletal Myotubes.

Directory of Open Access Journals (Sweden)

Dipankar Bhattacharya

Full Text Available The dihydropyridine receptor (DHPR β1a subunit is essential for skeletal muscle excitation-contraction coupling, but the structural organization of β1a as part of the macromolecular DHPR-ryanodine receptor type I (RyR1 complex is still debatable. We used fluorescence resonance energy transfer (FRET to probe proximity relationships within the β1a subunit in cultured skeletal myotubes lacking or expressing RyR1. The fluorescein biarsenical reagent FlAsH was used as the FRET acceptor, which exhibits fluorescence upon binding to specific tetracysteine motifs, and enhanced cyan fluorescent protein (CFP was used as the FRET donor. Ten β1a reporter constructs were generated by inserting the CCPGCC FlAsH binding motif into five positions probing the five domains of β1a with either carboxyl or amino terminal fused CFP. FRET efficiency was largest when CCPGCC was positioned next to CFP, and significant intramolecular FRET was observed for all constructs suggesting that in situ the β1a subunit has a relatively compact conformation in which the carboxyl and amino termini are not extended. Comparison of the FRET efficiency in wild type to that in dyspedic (lacking RyR1 myotubes revealed that in only one construct (H458 CCPGCC β1a -CFP FRET efficiency was specifically altered by the presence of RyR1. The present study reveals that the C-terminal of the β1a subunit changes conformation in the presence of RyR1 consistent with an interaction between the C-terminal of β1a and RyR1 in resting myotubes.

Antinociceptive Effect of Tephrosia sinapou Extract in the Acetic Acid, Phenyl-p-benzoquinone, Formalin, and Complete Freund’s Adjuvant Models of Overt Pain-Like Behavior in Mice

Directory of Open Access Journals (Sweden)

Renata M. Martinez

2016-01-01

Full Text Available Tephrosia toxicaria, which is currently known as Tephrosia sinapou (Buc’hoz A. Chev. (Fabaceae, is a source of compounds such as flavonoids. T. sinapou has been used in Amazonian countries traditional medicine to alleviate pain and inflammation. The purpose of this study was to evaluate the analgesic effects of T. sinapou ethyl acetate extract in overt pain-like behavior models in mice by using writhing response and flinching/licking tests. We demonstrated in this study that T. sinapou extract inhibited, in a dose (1–100 mg/kg dependent manner, acetic acid- and phenyl-p-benzoquinone- (PBQ- induced writhing response. Furthermore, it was active via intraperitoneal, subcutaneous, and peroral routes of administration. T. sinapou extract also inhibited formalin- and complete Freund’s adjuvant- (CFA- induced flinching/licking at 100 mg/kg dose. In conclusion, these findings demonstrate that T. sinapou ethyl acetate extract reduces inflammatory pain in the acetic acid, PBQ, formalin, and CFA models of overt pain-like behavior. Therefore, the potential of analgesic activity of T. sinapou indicates that it deserves further investigation.

Structural Basis of X-ray-Induced Transient Photo-bleaching in a Photoactivatable Green Fluorescent Protein

Energy Technology Data Exchange (ETDEWEB)

Adam, V. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France); Carpentier, Ph.; Lelimousin, M.; Darnault, C.; Bourgeois, D. [IBS, Institut de Biologie Structurale Jean-Pierre Ebel, CEA, CNRS, UniVersite Joseph Fourier, 41 rue Jules Horowitz, 38027 Grenoble (France); Violot, S. [Laboratoire de Physiologie Cellulaire Vegetale, Institut de Recherches en Technologie et Sciences pour le ViVant, CEA, CNRS, INRA, UniVersite Joseph Fourier, 17 rue des Martyrs, F-38054 Grenoble (France); Nienhaus, U. [Institute of Applied Physics and Center for Functional nano-structures (CFN), Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Nienhaus, U. [Department of Physics, UniVersity of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (US)

2009-07-01

We have observed the photoactivatable fluorescent protein IrisFP in a transient dark state with near-atomic resolution. This dark state is assigned to a radical species that either relaxes to the ground state or evolves into a permanently bleached chromophore. We took advantage of X-rays to populate the radical, which presumably forms under illumination with visible light by an electron-transfer reaction in the triplet state. The combined X-ray diffraction and in crystallo UV-vis absorption, fluorescence, and Raman data reveal that radical formation in IrisFP involves pronounced but reversible distortion of the chromophore, suggesting a transient loss of {pi} conjugation. These results reveal that the methylene bridge of the chromophore is the Achilles' heel of fluorescent proteins and help unravel the mechanisms of blinking and photo-bleaching in FPs, which are of importance in the rational design of photo-stable variants. and is also partly reversible. (authors)

An Optimized Method of Metabolite Extraction from Formalin-Fixed Paraffin-Embedded Tissue for GC/MS Analysis.

Science.gov (United States)

Wojakowska, Anna; Marczak, Łukasz; Jelonek, Karol; Polanski, Krzysztof; Widlak, Piotr; Pietrowska, Monika

2015-01-01

Formalin-fixed paraffin-embedded (FFPE) tissue specimens constitute a highly valuable source of clinical material for retrospective molecular studies. However, metabolomic assessment of such archival material remains still in its infancy. Hence, there is an urgent need for efficient methods enabling extraction and profiling of metabolites present in FFPE tissue specimens. Here we demonstrate the methodology for isolation of primary metabolites from archival tissues; either fresh-frozen, formalin-fixed or formalin-fixed and paraffin-embedded specimens of mouse kidney were analysed and compared in this work. We used gas chromatography followed by mass spectrometry (GC/MS approach) to identify about 80 metabolites (including amino acids, saccharides, carboxylic acids, fatty acids) present in such archive material. Importantly, about 75% of identified compounds were detected in all three types of specimens. Moreover, we observed that fixation with formalin itself (and their duration) did not affect markedly the presence of particular metabolites in tissue-extracted material, yet fixation for 24h could be recommended as a practical standard. Paraffin embedding influenced efficiency of extraction, which resulted in reduced quantities of several compounds. Nevertheless, we proved applicability of FFPE specimens for non-targeted GS/MS-based profiling of tissue metabolome, which is of great importance for feasibility of metabolomics studies using retrospective clinical material.

Laser-Induced Fluorescence (LIF) from plant foliage

Science.gov (United States)

Chappelle, Emmett W.; Williams, Darrel L.

1987-01-01

The fluorescence spectra and fluorescence induction kinetics of green plants excited at 337 nm by a laser were studied. They correlate with plant type, as well as with changes in the physiology of the plant as the result of stress. The plant types studied include herbaceous dicots, monocots, hardwoods, conifers, and algae. These plant types could be identified on the basis of differences in either the number of fluorescent bands or the relative intensity of the bands. Differences in fluorescent spectra which could be related to vigor status are observed in conifers located in an area of high atmospheric deposition. Changes in the fluorescence spectra and induction kinetics are also seen in plants grown under conditions of nutrient deficiency and drought stress.

Study on two-color planar laser induced fluorescence thermometry

International Nuclear Information System (INIS)

Li Shaodan; Tan Sichao; Gao Puzhen; Lin Yuansheng

2014-01-01

Many of the convection heat transfer process are involved in the research of nuclear reactor thermal hydraulics. To experimentally determine the variation of the temperature field in those processes is important for the design and safety operation of the nuclear reactor. The application of the two-color planar laser induced fluorescence (PLIF) in the measurements of fluid temperature distribution is discussed in the paper. The laser dyes used here is rhodamine B (RhB) with negative temperature coefficient and fluorescein 27 (F127) with positive temperature coefficient. The beam of the laser light is adjusted to laser sheet by using the lens group. The fluid with dyes is excited by this laser sheet in a specific plane and temperature dependent fluorescence is released. The temperature field of the plane can be determined through the intensity information. Some technical aspects encountered in the application of the two-laser PLIF are discussed in the paper, such as the spectra characteristic of the dyes and the separation of the spectra. The calibration temperature is higher than the water saturation temperature (at atmosphere pressure). (authors)

Instantaneous imaging of ozone in a gliding arc discharge using photofragmentation laser-induced fluorescence

Science.gov (United States)

Larsson, Kajsa; Hot, Dina; Gao, Jinlong; Kong, Chengdong; Li, Zhongshan; Aldén, Marcus; Bood, Joakim; Ehn, Andreas

2018-04-01

Ozone vapor, O3, is here visualized in a gliding arc discharge using photofragmentation laser-induced fluorescence. Ozone is imaged by first photodissociating the O3 molecule into an O radical and a vibrationally hot O2 fragment by a pump photon. Thereafter, the vibrationally excited O2 molecule absorbs a second (probe) photon that further transits the O2-molecule to an excited electronic state, and hence, fluorescence from the deexcitation process in the molecule can be detected. Both the photodissociation and excitation processes are achieved within one 248 nm KrF excimer laser pulse that is formed into a laser sheet and the fluorescence is imaged using an intensified CCD camera. The laser-induced signal in the vicinity of the plasma column formed by the gliding arc is confirmed to stem from O3 rather than plasma produced vibrationally hot O2. While both these products can be produced in plasmas a second laser pulse at 266 nm was utilized to separate the pump- from the probe-processes. Such arrangement allowed lifetime studies of vibrationally hot O2, which under these conditions were several orders of magnitude shorter than the lifetime of plasma-produced ozone.

Non-destructive monitoring of agricultural product (lettuce [Lactuca sativa]) based on laser-induced fluorescence

International Nuclear Information System (INIS)

Ishizawa, H.; Saito, Y.; Amemiya, T.; Komatu, K.

2002-01-01

Quality control of agricultural products in process of cultivation and distribution has become an important problem. This paper describes a field measuring method of lettuce based on laser induced fluorescence (LIF) spectroscopy for growth monitoring. Intensity at 460nm of LIF spectra showed characteristic variations of near harvest time. The results of chemical analysis confirmed that sucrose and chlorogenic acid are origins of the 460nm fluorescence. The prediction of harvest time and the possibility of quality monitoring are discussed based on the experimental data

Proteome stability analysis of snap frozen, RNAlater preserved, and formalin-fixed paraffin-embedded human colon mucosal biopsies

Directory of Open Access Journals (Sweden)

Tue Bjerg Bennike

2016-03-01

Full Text Available Large repositories of well characterized RNAlater preserved samples and formalin-fixed, paraffin-embedded samples have been generated worldwide. However, the impact on the proteome of the preservation methods remain poorly described. Therefore, we analyzed the impact on the proteome of preserving samples in RNAlater, and by formalin-fixation, paraffin-embedding on human soft tissue, using directly frozen samples as a control (“Comparing the proteome of snap frozen, RNAlater preserved, and formalin-fixed paraffin-embedded human tissue samples” [1]. We here report the data from the analysis. The comparative analysis was performed on 24 colon mucosa biopsies, extracted from the sigmoideum of two gastroenterologically healthy participants for the purpose of this study. A set of biopsies were additionally stored for 30 min at room temperature prior to formalin-fixation. The samples were analyzed by high throughput gel free quantitative proteomics. The MS proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PRIDE: http://www.ebi.ac.uk/pride/archive/projects/PXD002029. Keywords: Human, Colon, Mucosa, RNAlater, FFPE, Snap-frozen, Stability, LC–MS, Proteomics

Hydrogen bond strengthening induces fluorescence quenching of PRODAN derivative by turning on twisted intramolecular charge transfer

Science.gov (United States)

Yang, Yonggang; Li, Donglin; Li, Chaozheng; Liu, YuFang; Jiang, Kai

2017-12-01

Researchers have proposed different effective mechanisms of hydrogen bonding (HB) on the fluorescence of 6-propionyl-2-dimethylaminonaphthalene (PRODAN) and its derivatives. Herein, excited state transition and dynamics analysis confirm that the fluorescence of PD (a derivative of PRODAN with ethyl replaced by 3-hydroxy-2,2-dimethylpropan) emits from the planar intramolecular charge transfer (PICT) state rather than twist ICT (TICT) state, because the fluorescence emission and surface hopping from the TICT state to the twist ground (T-S0) state is energy forbidden. Nevertheless, the strengthening of intramolecular-HB (intra-HB) and intermolecular-HB (inter-HB) of PD-(methanol)2 smooth the pathway of surface hopping from TICT to T-S0 state and the external conversion going to planar ground state by decreasing the energy difference of the two states. This smoothing changes the fluorescence state of PD-(methanol)2 to the TICT state in which fluorescence emission does not occur but surface hopping, leading to the partial fluorescence quenching of PD in methanol solvent. This conclusion is different from previous related reports. Moreover, the inter-HB strengthening of PD-methanol in PICT state induces the cleavage of intra-HB and a fluorescence red-shift of 54 nm compared to PD. This red-shift increases to 66 nm for PD-(methanol)2 for the strengthening of the one intra-HB and two inter-HBs. The dipole moments of PD-methanol and PD-(methanol)2 respectively increase about 10.3D and 8.1D in PICT state compared to PD. The synergistic effect of intra-HB and inter-HB induces partial quenching of PD in methanol solvent by turning on the TICT state and fluorescence red-shift. This work gives a reasonable description on the fluorescence red-shift and partial quenching of PD in methanol solvent, which will bring insight into the study of spectroscopic properties of molecules owning better spectral characteristics.

FluorWPS: A Monte Carlo ray-tracing model to compute sun-induced chlorophyll fluorescence of three-dimensional canopy

Science.gov (United States)

A model to simulate radiative transfer (RT) of sun-induced chlorophyll fluorescence (SIF) of three-dimensional (3-D) canopy, FluorWPS, was proposed and evaluated. The inclusion of fluorescence excitation was implemented with the ‘weight reduction’ and ‘photon spread’ concepts based on Monte Carlo ra...

Porphyrin involvement in redshift fluorescence in dentin decay

Science.gov (United States)

Slimani, A.; Panayotov, I.; Levallois, B.; Cloitre, T.; Gergely, C.; Bec, N.; Larroque, C.; Tassery, H.; Cuisinier, F.

2014-05-01

The aim of this study was to evaluate the porphyrin involvement in the red fluorescence observed in dental caries with Soprolife® light-induced fluorescence camera in treatments mode (SOPRO, ACTEON Group, La Ciotat, France) and Vistacam® camera (DÜRR DENTAL AG, Bietigheim-Bissingen, Germany). The International Caries Detection and Assessment System (ICDAS) was used to rand the samples. Human teeth cross-sections, ranked from ICDAS score 0 to 6, were examined by epi-fluorescence microscopy and Confocal Raman microscopy. Comparable studies were done with Protoporphyrin IX, Porphyrin I and Pentosidine solutions. An RGB analysis of Soprolife® images was performed using ImageJ Software (1.46r, National Institutes of Health, USA). Fluorescence spectroscopy and MicroRaman spectroscopy revealed the presence of Protoporphyrin IX, in carious enamel, dentin and dental plaque. However, the presence of porphyrin I and pentosidine cannot be excluded. The results indicated that not only porphyrin were implicated in the red fluorescence, Advanced Glygation Endproducts (AGEs) of the Maillard reaction also contributed to this phenomenon.

Examinations for the determination of the flux density of sputtered iron using laser induced fluorescence

International Nuclear Information System (INIS)

Schweer, H.B.

1983-11-01

In this work investigations are described to measure the flux density of sputtered iron atoms by means of laser induced fluorescence. In a laboratory experiment an iron target (stainless steel 316, Inconel 600), was bombarded with 10 keV Ar + and 2.5 keV H + and the population distribution of the energy levels of the ground state a 5 D and the metastable state a 5 F was measured. In the plasma wall region in the ISX-B tokamak at the Oak Ridge National Laboratory (USA) neutral iron atoms were measured the first time by laser induced fluorescence. A detection limit of 10 6 atoms/cm 3 was found and sputtered iron atoms were observed in the first 15 ms of the discharge. (orig./BRB)

Quantitative fluorescence lifetime spectroscopy in turbid media: comparison of theoretical, experimental and computational methods

International Nuclear Information System (INIS)

Vishwanath, Karthik; Mycek, Mary-Ann; Pogue, Brian

2002-01-01

A Monte Carlo model developed to simulate time-resolved fluorescence propagation in a semi-infinite turbid medium was validated against previously reported theoretical and computational results. Model simulations were compared to experimental measurements of fluorescence spectra and lifetimes on tissue-simulating phantoms for single and dual fibre-optic probe geometries. Experiments and simulations using a single probe revealed that scattering-induced artefacts appeared in fluorescence emission spectra, while fluorescence lifetimes were unchanged. Although fluorescence lifetime measurements are generally more robust to scattering artefacts than are measurements of fluorescence spectra, in the dual-probe geometry scattering-induced changes in apparent lifetime were predicted both from diffusion theory and via Monte Carlo simulation, as well as measured experimentally. In all cases, the recovered apparent lifetime increased with increasing scattering and increasing source-detector separation. Diffusion theory consistently underestimated the magnitude of these increases in apparent lifetime (predicting a maximum increase of ∼15%), while Monte Carlo simulations and experiment were closely matched (showing increases as large as 30%). These results indicate that quantitative simulations of time-resolved fluorescence propagation in turbid media will be important for accurate recovery of fluorophore lifetimes in biological spectroscopy and imaging applications. (author)

pXRF and IR Fluorescence Imaging Studies of CdS Alteration in Paintings by Edvard Munch and Henri Matisse in Oslo, Copenhagen, and San Francisco

DEFF Research Database (Denmark)

Vila, Anna; Wadum, Jørgen; Mass, Jennifer

2014-01-01

-induced visible fluorescence; ultraviolet-induced infrared fluorescence; multispectral imaging; and x-ray fluorescence. Questions addressed included: is the imaging method being tested comprehensive? Is it efficient at surveying an entire painting? Does it reveal the state of preservation of the pigment? Does...... for Kunst, Copenhagen. They were also tested on Edvard Munch’s The Scream (c. 1910, Munch Museum, Oslo). It was found that ultraviolet-induced visible fluorescence has the best ability to discriminate between altered and unaltered cadmium yellow paints (even before alteration is visible to the unaided eye......), while multispectral imaging allows for the most efficient and comprehensive localization of the cadmium pigments in a work....

Physiological effects of potassium chloride, formalin and handling stress on bonytail

Science.gov (United States)

Sykes, Catherine L.; Caldwell, Colleen A.; Gould, William R.

2011-01-01

We characterized the sublethal physiological changes in bonytail Gila elegans subjected to consecutive 750-mg/L potassium chloride (KCl) and 25-mg/L formalin treatments for the removal of zebra mussel Dreissena polymorpha and quagga mussel D. bugensis veligers. Plasma cortisol, glucose, and osmolality were measured over 24 h and at 14 d posthandling after exposing bonytail to KCl and one net stressor (capture with a net), KCl plus formalin and two net stressors, and one or two net stressors without chemicals. Elevated plasma cortisol (322–440 ng/mL) and glucose (254–399 mg/dL) concentrations were observed in all treatments compared with the concentrations in control fish (plasma cortisol, 56 ng/mL; glucose, 43 mg/dL). While there were no detectable differences in plasma osmolality among the treatment and control fish, a difference was observed between fish that were handled once versus twice. Chemical effects of stress were not observed in any of the physiological responses when the KCl treatment was compared with the one-net stressor treatment or when the KCl plus formalin treatment was compared with the two-net stressor treatment. Cumulative responses, however, were observed between one net stressor and two net stressors for plasma glucose and osmolality but not for plasma cortisol. Plasma cortisol and glucose levels remained elevated at 24 h posthandling, indicating that bonytail had not completely recovered from the handling stressors and would benefit from a recovery period in protected refugia before being released.

The Methanolic Extract from Murraya koenigii L. Inhibits Glutamate-Induced Pain and Involves ATP-Sensitive K+ Channel as Antinociceptive Mechanism

Directory of Open Access Journals (Sweden)

Nushrat Sharmin Ani

2016-01-01

Full Text Available Murraya koenigii L. is a perennial shrub, belonging to the family Rutaceae. Traditionally, the leaves of this plant are extensively used in treatment of a wide range of diseases and disorders including pain and inflammation. Although researchers have revealed the antinociceptive effects of this plant’s leaves during past few years, the mechanisms underlying these effects are still unknown. Therefore, the present study evaluated some antinociceptive mechanisms of the methanolic extract of M. koenigii (MEMK leaves along with its antinociceptive potential using several animal models. The antinociceptive effects of MEMK were evaluated using formalin-induced licking and acetic acid-induced writhing tests at the doses of 50, 100, and 200 mg/kg. In addition, we also justified the possible participations of glutamatergic system and ATP-sensitive potassium channels in the observed activities. Our results demonstrated that MEMK significantly (p<0.01 inhibited the pain thresholds induced by formalin and acetic acid in a dose-dependent manner. MEMK also significantly (p<0.01 suppressed glutamate-induced pain. Moreover, pretreatment with glibenclamide (an ATP-sensitive potassium channel blocker at 10 mg/kg significantly (p<0.05 reversed the MEMK-mediated antinociception. These revealed that MEMK might have the potential to interact with glutamatergic system and the ATP-sensitive potassium channels to exhibit its antinociceptive activities. Therefore, our results strongly support the antinociceptive effects of M. koenigii leaves and provide scientific basis of their analgesic uses in the traditional medicine.

Laser-induced Fluorescence Spectroscopy for applications in chemical sensing and optical refrigeration

Science.gov (United States)

Kumi Barimah, Eric

limit of detection for ClO4, was determined to be 14.7 +/- 0.5 wt%/wt for the given experimental conditions. In the second part of this research, the temperature-dependent absorption and emission properties of Tm doped KPb2Cl5 (KPC) and KPb2Br5 (KPB) were evaluated for applications in laser cooling. A Tm doped Y3Al5O12 (YAG) crystal was also included for comparative studies. Under laser pumping, all crystals exhibited broad IR fluorescence at room temperature with a mean fluorescence wavelength of ˜1.82 mum and bandwidth of 0.14 mum (FWHM) for Tm:KPC/KPB and ˜1.79 mum for Tm:YAG. Initial experiments on laser-induced heating/cooling were performed using a combined IR imaging and fluorescence thermometry setup. Employing a continuous-wave laser operating at 1.907 mum, Tm: KPC and Tm: KPB crystals revealed a very small heat load resulting in temperature increase of ˜ 0.3 ( +/- 0.1)°C. The heat loading in Tm:YAG was signicantly larger and resulted in a temperature increase of ˜0.9 (+/-0.1)°C. The results derived from IR imaging were also conrmed by the fluorescence thermometry experiments, which showed only minimal changes in the FIR intensity ratio of the green Er3+ fluorescence lines from Er:KPC.

Red and far red Sun-induced chlorophyll fluorescence as a measure of plant photosynthesis

Czech Academy of Sciences Publication Activity Database

Rossini, P. M.; Nedbal, L.; Guanter, L.; Ač, Alexander; Alonso, L.; Burkart, A.; Cogliati, S.; Colombo, R.; Damm, A.; Drusch, M.; Hanuš, Jan; Janoutová, Růžena; Julitta, T.; Kokkalis, P.; Moreno, J.; Novotný, Jan; Panigada, C.; Pinto, F.; Schickling, A.; Schuettemeyer, D.; Zemek, František; Rascher, U.

2015-01-01

Roč. 42, č. 6 (2015), s. 1632-1639 ISSN 0094-8276 Institutional support: RVO:67179843 Keywords : sun-induced fluorescence * remote sensing * stress detection * airborne images * HyPlant Subject RIV: EH - Ecology, Behaviour Impact factor: 4.212, year: 2015

The effects of visual fluorescence marking induced by 5-aminolevulinic acid for endoscopic diagnosis of urinary bladder cancer

Science.gov (United States)

Daniltchenko, Dmitri I.; Koenig, Frank; Schnorr, Dietmar; Valdman, Alexander; Al-Shukri, Salman; Loening, Stefan A.

2003-10-01

During cystoscopy procedure, fluorescence diagnostics induced by 5-ALA improves visual detection of the bladder cancer. Macroscopic ALA-fluorescence allows visualizing of small flat tumors, carcinoma in situ, true neoplasm margins and dysplasias of the bladder. Following ALA instillation, cystoscopy has been performed under both standard and blue light illumination. Totally, 153 biopsies have been carried out at 53 patients with suspicion of bladder cancer. The results were compared to ALA-fluorescence data. In 13% of the patients, bladder cancer and dysplasia were found out in addition, due to red fluorescence. The sensitivity and specificity of ALA-fluorescence technique aggregated 96% and 52% respectively. The sensitivity and specificity of 5-ALA-fluorescent detection exceeded standard endoscopy under white light on 20%. The new method does not exclude a false positive and a false negative fluorescent luminescence. The ALA-based fluorescence detection system enhances the diagnosis of malignant/dysplastic bladder lesions significantly.

A miniaturized oxygen sensor integrated on fiber surface based on evanescent-wave induced fluorescence quenching

Energy Technology Data Exchange (ETDEWEB)

Xiong, Yan [School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Oil and Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, 610500 (China); Tan, Jun; Wang, Chengjie; Zhu, Ying [School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Fang, Shenwen [School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Oil and Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, 610500 (China); Wu, Jiayi; Wang, Qing [School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Duan, Ming, E-mail: swpua124@126.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500 (China); School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Oil and Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, 610500 (China)

2016-11-15

In this work, a miniaturized sensor was integrated on fiber surface and developed for oxygen determination through evanescent-wave induced fluorescence quenching. The sensor was designed by using light emitting diode (LED) as light source and optical fiber as light transmission element. Tris(2,2′-bipyridyl) ruthenium ([Ru(bpy){sub 3}]{sup 2+}) fluorophore was immobilized in the organically modified silicates (ORMOSILs) film and coated onto the fiber surface. When light propagated by total internal reflection (TIR) in the fiber core, evanescent wave could be produced on the fiber surface and excite [Ru(bpy){sub 3}]{sup 2+} fluorophore to produce fluorescence emission. Then oxygen could be determinated by its quenching effect on the fluorescence and its concentration could be evaluated according to Stern–Volumer model. Through integrating evanescent wave excitation and fluorescence quenching on fiber surface, the sensor was successfully miniaturized and exhibit improved performances of high sensitivity (1.4), excellent repeatability (1.2%) and fast analysis (12 s) for oxygen determination. The sensor provided a newly portable method for in-situ and real-time measurement of oxygen and showed potential for practical oxygen analysis in different application fields. Furthermore, the fabrication of this sensor provides a miniaturized and portable detection platform for species monitoring by simple modular design. - Highlights: • ORMOSILs sensing film immobilized with [Ru(bpy){sub 3}]{sup 2+} fluorophore was coated on fiber surface. • Evanescent wave on the fiber surface was utilized as excitation source to produce fluorescence. • Oxygen was measured based on its quenching effect on evanescent wave-induce fluorescence. • Sensor fabrication was miniaturized by integrating detection and sensing elements on the fiber. • The modular design sensor provides a detection platform for other species monitoring.

The structure of mAG, a monomeric mutant of the green fluorescent protein Azami-Green, reveals the structural basis of its stable green emission

International Nuclear Information System (INIS)

Ebisawa, Tatsuki; Yamamura, Akihiro; Kameda, Yasuhiro; Hayakawa, Kou; Nagata, Koji; Tanokura, Masaru

2010-01-01

The crystal structure of a monomeric mutant of Azami-Green (mAG) from G. fascicularis was determined at 2.2 Å resolution. Monomeric Azami-Green (mAG) from the stony coral Galaxea fascicularis is the first known monomeric green-emitting fluorescent protein that is not a variant of Aequorea victoria green fluorescent protein (avGFP). These two green fluorescent proteins are only 27% identical in their amino-acid sequences. mAG is more similar in its amino-acid sequence to four fluorescent proteins: Dendra2 (a green-to-red irreversibly photoconverting fluorescent protein), Dronpa (a bright-and-dark reversibly photoswitchable fluorescent protein), KikG (a tetrameric green-emitting fluorescent protein) and Kaede (another green-to-red irreversibly photoconverting fluorescent protein). To reveal the structural basis of stable green emission by mAG, the 2.2 Å crystal structure of mAG has been determined and compared with the crystal structures of avGFP, Dronpa, Dendra2, Kaede and KikG. The structural comparison revealed that the chromophore formed by Gln62-Tyr63-Gly64 (QYG) and the fixing of the conformation of the imidazole ring of His193 by hydrogen bonds and van der Waals contacts involving His193, Arg66 and Thr69 are likely to be required for the stable green emission of mAG. The crystal structure of mAG will contribute to the design and development of new monomeric fluorescent proteins with faster maturation, brighter fluorescence, improved photostability, new colours and other preferable properties as alternatives to avGFP and its variants

Efficacy of formalin, hydrogen-peroxide, and sodium-chloride on fungal-infected rainbow-trout eggs

Science.gov (United States)

Schreier, Theresa M.; Rach, J.J.; Howe, G.E.

1996-01-01

Antifungal agents are essential for the maintenance of healthy stocks of fish and their eggs in intensive aquaculture operations. In the usa, formalin is the only fungicide approved for use in fish culture, however, hydrogen peroxide and sodium chloride have been granted low regulatory priority drug status by the united states food and drug administration (fda) and their use is allowed. We evaluated the efficacy of these fungicides for controlling fungal infections on rainbow trout eggs. A pilot study was conducted to determine the minimum water flow rate required to administer test chemicals accurately in heath incubators. A minimum water flow rate of 7.6 1 min(-1) was necessary to maintain treatment concentrations during flow-through chemical exposures, the antifungal activity of formalin, hydrogen peroxide, and sodium chloride was evaluated by treating uninfected and 10% fungal-infected (saprolegnia parasitica) rainbow trout eggs (oncorhynchus mykiss) for 15 min every other day until hatch. There were no significant differences among treatments in percent hatch or final infection for uninfected eggs receiving prophylactic chemical treatments, eggs of the negative control group (uninfected and untreated) had a mean hatch exceeding 86%, all chemical treatments conducted on the infected egg groups controlled the spread of fungus and improved hatching success compared with the positive control groups (infected and untreated), formalin treatments of 1000 and 1500 mu l 1(-1) and hydrogen peroxide treatments of 500 and 1000 mu l 1(-1) were the most effective. Sodium chloride treatments of 30000 mg 1(-1) improved fry hatch, but the compound was less effective at inhibiting fungal growths compared with hydrogen peroxide and formalin treatments.

Diagnostics of Susabi-nori (Porphyra Yezoensis) by Laser-Induced Fluorescence Method

Science.gov (United States)

Okamoto, Tamotsu; Nakamura, Yuki; Takahashi, Kunio; Kaneko, Shohei; Shimada, Yuji

Susabi-nori (Porphyra yezoensis) was diagnosed by means of laser-induced fluorescence (LIF) method. Fluorescence peaks located at approximately 580, 660, 685 and 720 nm were observed in the LIF spectra of Susabi-nori. In the spectrum of the sample infected with the red rot disease, the intensity of 580 nm peak was relatively high as compared with that of the control sample. On the other hand, the intensities of 580 nm and 660 nm peaks drastically decreased by the influence of the chytrid disease. Furthermore, the intensity of the 580 nm peak increased by dipping into fresh water. These results indicate that LIF spectra of Susabi-nori are affected by the diseases and the stress of fresh water and that the diseases and the stress of Susabi-nori can be diagnosed by the LIF method.

Novel xenon calibration scheme for two-photon absorption laser induced fluorescence of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Elliott, Drew; Scime, Earl; Short, Zachary, E-mail: zdshort@mix.wvu.edu [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26056 (United States)

2016-11-15

Two photon absorption laser induced fluorescence (TALIF) measurements of neutral hydrogen and its isotopes are typically calibrated by performing TALIF measurements on krypton with the same diagnostic system and using the known ratio of the absorption cross sections [K. Niemi et al., J. Phys. D 34, 2330 (2001)]. Here we present the measurements of a new calibration method based on a ground state xenon scheme for which the fluorescent emission wavelength is nearly identical to that of hydrogen, thereby eliminating chromatic effects in the collection optics and simplifying detector calibration. We determine that the ratio of the TALIF cross sections of xenon and hydrogen is 0.024 ± 0.001.

Measurements of T1 and T2 over time in formalin-fixed human whole-brain specimens

International Nuclear Information System (INIS)

Tovi, M.; Ericsson, A.

1992-01-01

T1 and T2 were measured in 5 formalin-fixed human whole-brain specimens as a function of time. Gray matter/white matter contrast reversal was observed around the 4th day and was considered to be due to the greater decrease in T1 in gray than in white matter. A possible explanation for this is that the decomposition of the myelin phospholipid structure by formalin somewhat counteracts the general reductive effect of the fixation procedure on relaxation times. (orig.)

High Quality Genomic Copy Number Data from Archival Formalin-Fixed Paraffin-Embedded Leiomyosarcoma: Optimisation of Universal Linkage System Labelling

Science.gov (United States)

Salawu, Abdulazeez; Ul-Hassan, Aliya; Hammond, David; Fernando, Malee; Reed, Malcolm; Sisley, Karen

2012-01-01

Most soft tissue sarcomas are characterized by genetic instability and frequent genomic copy number aberrations that are not subtype-specific. Oligonucleotide microarray-based Comparative Genomic Hybridisation (array CGH) is an important technique used to map genome-wide copy number aberrations, but the traditional requirement for high-quality DNA typically obtained from fresh tissue has limited its use in sarcomas. Although large archives of Formalin-fixed Paraffin-embedded (FFPE) tumour samples are available for research, the degradative effects of formalin on DNA from these tissues has made labelling and analysis by array CGH technically challenging. The Universal Linkage System (ULS) may be used for a one-step chemical labelling of such degraded DNA. We have optimised the ULS labelling protocol to perform aCGH on archived FFPE leiomyosarcoma tissues using the 180k Agilent platform. Preservation age of samples ranged from a few months to seventeen years and the DNA showed a wide range of degradation (when visualised on agarose gels). Consistently high DNA labelling efficiency and low microarray probe-to-probe variation (as measured by the derivative log ratio spread) was seen. Comparison of paired fresh and FFPE samples from identical tumours showed good correlation of CNAs detected. Furthermore, the ability to macro-dissect FFPE samples permitted the detection of CNAs that were masked in fresh tissue. Aberrations were visually confirmed using Fluorescence in situ Hybridisation. These results suggest that archival FFPE tissue, with its relative abundance and attendant clinical data may be used for effective mapping for genomic copy number aberrations in such rare tumours as leiomyosarcoma and potentially unravel clues to tumour origins, progression and ultimately, targeted treatment. PMID:23209738

DHA-fluorescent probe is sensitive to membrane order and reveals molecular adaptation of DHA in ordered lipid microdomains☆

Science.gov (United States)

Teague, Heather; Ross, Ron; Harris, Mitchel; Mitchell, Drake C.; Shaikh, Saame Raza

2012-01-01

Docosahexaenoic acid (DHA) disrupts the size and order of plasma membrane lipid microdomains in vitro and in vivo. However, it is unknown how the highly disordered structure of DHA mechanistically adapts to increase the order of tightly packed lipid microdomains. Therefore, we studied a novel DHA-Bodipy fluorescent probe to address this issue. We first determined if the DHA-Bodipy probe localized to the plasma membrane of primary B and immortal EL4 cells. Image analysis revealed that DHA-Bodipy localized into the plasma membrane of primary B cells more efficiently than EL4 cells. We then determined if the probe detected changes in plasma membrane order. Quantitative analysis of time-lapse movies established that DHA-Bodipy was sensitive to membrane molecular order. This allowed us to investigate how DHA-Bodipy physically adapted to ordered lipid microdomains. To accomplish this, we employed steady-state and time-resolved fluorescence anisotropy measurements in lipid vesicles of varying composition. Similar to cell culture studies, the probe was highly sensitive to membrane order in lipid vesicles. Moreover, these experiments revealed, relative to controls, that upon incorporation into highly ordered microdomains, DHA-Bodipy underwent an increase in its fluorescence lifetime and molecular order. In addition, the probe displayed a significant reduction in its rotational diffusion compared to controls. Altogether, DHA-Bodipy was highly sensitive to membrane order and revealed for the first time that DHA, despite its flexibility, could become ordered with less rotational motion inside ordered lipid microdomains. Mechanistically, this explains how DHA acyl chains can increase order upon formation of lipid microdomains in vivo. PMID:22841541

Detection of radiation-induced brain necrosis in live rats using label-free time-resolved fluorescence spectroscopy (TRFS) (Conference Presentation)

Science.gov (United States)

Hartl, Brad A.; Ma, Htet S. W.; Sridharan, Shamira; Hansen, Katherine; Klich, Melanie; Perks, Julian; Kent, Michael; Kim, Kyoungmi; Fragoso, Ruben; Marcu, Laura

2017-02-01

Differentiating radiation-induced necrosis from recurrent tumor in the brain remains a significant challenge to the neurosurgeon. Clinical imaging modalities are not able to reliably discriminate the two tissue types, making biopsy location selection and surgical management difficult. Label-free fluorescence lifetime techniques have previously been shown to be able to delineate human brain tumor from healthy tissues. Thus, fluorescence lifetime techniques represent a potential means to discriminate the two tissues in real-time during surgery. This study aims to characterize the endogenous fluorescence lifetime signatures from radiation induced brain necrosis in a tumor-free rat model. Fischer rats received a single fraction of 60 Gy of radiation to the right hemisphere using a linear accelerator. Animals underwent a terminal live surgery after gross necrosis had developed, as verified with MRI. During surgery, healthy and necrotic brain tissue was measured with a fiber optic needle connected to a multispectral fluorescence lifetime system. Measurements of the necrotic tissue showed a 48% decrease in intensity and 20% increase in lifetimes relative to healthy tissue. Using a support vector machine classifier and leave-one-out validation technique, the necrotic tissue was correctly classified with 94% sensitivity and 97% specificity. Spectral contribution analysis also confirmed that the primary source of fluorescence contrast lies within the redox and bound-unbound population shifts of nicotinamide adenine dinucleotide. A clinical trial is presently underway to measure these tissue types in humans. These results show for the first time that radiation-induced necrotic tissue in the brain contains significantly different metabolic signatures that are detectable with label-free fluorescence lifetime techniques.

Laser-induced fluorescence detection platform for point-of-care testing

Science.gov (United States)

Berner, Marcel; Hilbig, Urs; Schubert, Markus B.; Gauglitz, Günter

2017-08-01

Point-of-care testing (POCT) devices for continuous low-cost monitoring of critical patient parameters require miniaturized and integrated setups for performing quick high-sensitivity analyses, away from central clinical laboratories. This work presents a novel and promising laser-induced fluorescence platform for measurements in direct optical test formats that leads towards such powerful POCT devices based on fluorescence-labeled immunoassays. Ultimate sensitivity of thin film photodetectors, integrated with microfluidics, and a comprehensive optimization of all system components aim at low-level signal detection in the targeted biosensor application. The setup acquires fluorescence signals from the volume of a microfluidic channel. An innovative sandwiching process forms a flow channel in the microfluidic chips by embedding laser-cut double-sided adhesive tapes. The custom fit of amorphous silicon based photodiode arrays to the geometry of the flow channel enables miniaturization, fully adequate for POCT devices. A free-beam laser excitation with line focus provides excellent alignment stability, allows for easy and reliable swapping of the disposable microfluidic chips, and therewith greatly improves the ease of use of the resulting integrated device. As a proof-of-concept of this novel in-volume measurement approach, the limit of detection for the dye DY636-COOH in pure water as a model fluorophore is examined and found to be 26 nmol l-1 .

Detection of organic residues on poultry processing equipment surfaces by LED-induced fluorescence imaging

Science.gov (United States)

Organic residues on equipment surfaces in poultry processing plants can generate cross- contamination and increase the risk of unsafe food for consumers. This research was aimed to investigate the potential of LED-induced fluorescence imaging technique for rapid inspection of stainless steel proces...

Cardiac c-Kit Biology Revealed by Inducible Transgenesis.

Science.gov (United States)

Gude, Natalie A; Firouzi, Fareheh; Broughton, Kathleen M; Ilves, Kelli; Nguyen, Kristine P; Payne, Christina R; Sacchi, Veronica; Monsanto, Megan M; Casillas, Alexandria R; Khalafalla, Farid G; Wang, Bingyan J; Ebeid, David E; Alvarez, Roberto; Dembitsky, Walter P; Bailey, Barbara A; van Berlo, Jop; Sussman, Mark A

2018-06-22

Biological significance of c-Kit as a cardiac stem cell marker and role(s) of c-Kit+ cells in myocardial development or response to pathological injury remain unresolved because of varied and discrepant findings. Alternative experimental models are required to contextualize and reconcile discordant published observations of cardiac c-Kit myocardial biology and provide meaningful insights regarding clinical relevance of c-Kit signaling for translational cell therapy. The main objectives of this study are as follows: demonstrating c-Kit myocardial biology through combined studies of both human and murine cardiac cells; advancing understanding of c-Kit myocardial biology through creation and characterization of a novel, inducible transgenic c-Kit reporter mouse model that overcomes limitations inherent to knock-in reporter models; and providing perspective to reconcile disparate viewpoints on c-Kit biology in the myocardium. In vitro studies confirm a critical role for c-Kit signaling in both cardiomyocytes and cardiac stem cells. Activation of c-Kit receptor promotes cell survival and proliferation in stem cells and cardiomyocytes of either human or murine origin. For creation of the mouse model, the cloned mouse c-Kit promoter drives Histone2B-EGFP (enhanced green fluorescent protein; H2BEGFP) expression in a doxycycline-inducible transgenic reporter line. The combination of c-Kit transgenesis coupled to H2BEGFP readout provides sensitive, specific, inducible, and persistent tracking of c-Kit promoter activation. Tagging efficiency for EGFP+/c-Kit+ cells is similar between our transgenic versus a c-Kit knock-in mouse line, but frequency of c-Kit+ cells in cardiac tissue from the knock-in model is 55% lower than that from our transgenic line. The c-Kit transgenic reporter model reveals intimate association of c-Kit expression with adult myocardial biology. Both cardiac stem cells and a subpopulation of cardiomyocytes express c-Kit in uninjured adult heart

Coumarin–pyrene conjugate: Synthesis, structure and Cu-selective fluorescent sensing in mammalian kidney cells

Energy Technology Data Exchange (ETDEWEB)

Wani, Manzoor Ahmad [Department of Chemistry, Dr. H. S. Gour Central University Sagar, MP 470003 (India); Singh, Pankaj Kumar [Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Pandey, Rampal, E-mail: rpvimlesh@gmail.com [Department of Chemistry, Dr. H. S. Gour Central University Sagar, MP 470003 (India); Pandey, Mrituanjay D., E-mail: mdpandey@dhsgsu.ac.in [Department of Chemistry, Dr. H. S. Gour Central University Sagar, MP 470003 (India)

2016-03-15

In this work, we report a coumarin–pyrene based fluorescent probes (E)-7-(diethylamino)-3-((pyren-1-ylimino)methyl)-2H-chromen-2-one (1) and (E)-7-(diethylamino)-3-((pyren-1-ylmethylimino)methyl)-2H-chromen-2-one (2) for the selective detection of Cu{sup 2+} ion. Receptor 1 upon binding with Cu{sup 2+} exhibited substantial fluorescence quenching as a detection response. Probe 1 induces green fluorescence in a cell lines derived from monkey kidney tissue and subsequent quenching of fluorescence in these cells manifest that 1 can probably be used as a potential fluorescent sensor for the detection of Cu{sup 2+} in biological samples too. However, 2 does not reveal any significant fluorescence change in presence of different metal ions. It is assumed that conjugation might be accountable for the discrete fluorescent behavior of 1 and 2.

Performance of a two-leaf light use efficiency model for mapping gross primary productivity against remotely sensed sun-induced chlorophyll fluorescence data.

Science.gov (United States)

Zan, Mei; Zhou, Yanlian; Ju, Weimin; Zhang, Yongguang; Zhang, Leiming; Liu, Yibo

2018-02-01

Estimating terrestrial gross primary production is an important task when studying the carbon cycle. In this study, the ability of a two-leaf light use efficiency model to simulate regional gross primary production in China was validated using satellite Global Ozone Monitoring Instrument - 2 sun-induced chlorophyll fluorescence data. The two-leaf light use efficiency model was used to estimate daily gross primary production in China's terrestrial ecosystems with 500-m resolution for the period from 2007 to 2014. Gross primary production simulated with the two-leaf light use efficiency model was resampled to a spatial resolution of 0.5° and then compared with sun-induced chlorophyll fluorescence. During the study period, sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model exhibited similar spatial and temporal patterns in China. The correlation coefficient between sun-induced chlorophyll fluorescence and monthly gross primary production simulated by the two-leaf light use efficiency model was significant (pproduction simulated by the two-leaf light use efficiency model were similar in spring and autumn in most vegetated regions, but dissimilar in winter and summer. The spatial variability of sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model was similar in spring, summer, and autumn. The proportion of spatial variations of sun-induced chlorophyll fluorescence and annual gross primary production simulated by the two-leaf light use efficiency model explained by ranged from 0.76 (2011) to 0.80 (2013) during the study period. Overall, the two-leaf light use efficiency model was capable of capturing spatial and temporal variations in gross primary production in China. However, the model needs further improvement to better simulate gross primary production in summer. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of uranium in bituminized radioactive waste drums by self-induced X-ray fluorescence

International Nuclear Information System (INIS)

Pin, Patrick; Perot, Bertrand

2013-06-01

This paper reports the experimental qualification of an original uranium characterization method based on fluorescence X rays induced by the spontaneous gamma emission of bituminized radioactive waste drums. The main 661.7 keV gamma ray following the 137 Cs decay produces by Compton scattering in the bituminized matrix an intense photon continuum around 100 keV, i.e. in the uranium X-ray fluorescence region. 'Self-induced' X-rays produced without using an external source allow a quantitative assessment of uranium as 137 Cs and uranium are homogeneously mixed and distributed in the bituminized matrix. The paper presents the experimental qualification of the method with real waste drums, showing a detection limit well below 1 kg of uranium in 20 min acquisitions while the usual gamma rays of 235 U (185 keV) or 238 U (1001 keV of 234m Pa in the radioactive decay chain) are not detected. The relative uncertainty on the uranium mass assessed by self-induced X-ray fluorescence (SXRF) is about 50%, with a 95% confidence level, taking into account the correction of photon attenuation in the waste matrix. This last indeed contains high atomic numbers elements like uranium, but also barium, in quantities which are not known for each drum. Attenuation is estimated thanks to the peak-to-Compton ratio to limit the corresponding uncertainty. The SXRF uranium masses measured in the real drums are in good agreement with long gamma-ray spectroscopy measurements (1001 keV peak) or with radiochemical analyses. (authors)

Laser resonant ionization spectroscopy and laser-induced resonant fluorescence spectra of samarium atom

International Nuclear Information System (INIS)

Jin, Changtai

1995-01-01

We have measured new high-lying levels of Sm atom by two-colour resonant photoionisation spectroscopy; we have observed the isotope shifts of Sm atom by laser-induced resonant fluorescence spectroscopy; the lifetime of eight low-lying levels of Sm atom were measured by using pulsed laser-Boxcar technique in atomic beam.

Laser-induced fluorescence studies of premalignant and benign lesions in the female genital tract

Science.gov (United States)

af Klinteberg, Claes; Wang, Ingrid; Lindquist, Charlotta; Vaitkuviene, Aurelija; Svanberg, Katarina

1997-12-01

Laser-induced fluorescence (LIF) was studied in vivo from premalignant and benign lesions in the female genital tract, in particular the cervix. The aim of the study was to investigate the possibilities to differentiate cervical intraepithelial neoplasia (CIN) from normal tissue by means of two different fluorescence modalities. Most of the patients were given a low dose (5 mg/kg bw) of (delta) -amino levulinic acid (ALA). The ALA was orally administered 2 - 4 hours prior to the investigation. During this time, the ALA is transformed to the strongly fluorescent protoporphyrin IX (PpIX) via the haem cycle. Excitation light with a wavelength of 405 nm was used to excite the PpIX fluorescence. Excess amounts of PpIX were accumulated preferentially in diseased tissue. However, the variability in the PpIX accumulation from patient to patient was large. By using excitation light at 337 nm, the endogenous fluorophores are more efficiently excited. Therefore, this excitation modality was exploited for studying spectral characteristics of the autofluorescence in different tissue types. The spectra obtained were evaluated by forming fluorescence intensity ratios. The tissue types were grouped according to the histopathological examination. A correlation with the fluorescence ratios was performed. Some problems with the classification remain, mostly due to the difficulties in obtaining histopathologic evaluation of the biopsies at the exact location of the LIF measurements.

An operational fluorescence system for crop assessment

Science.gov (United States)

Belzile, Charles; Belanger, Marie-Christine; Viau, Alain A.; Chamberland, Martin; Roy, Simon

2004-03-01

The development of precision farming requires new tools for plant nutritional stress monitoring. An operational fluorescence system has been designed for vegetation status mapping and stress detection at plant and field scale. The instrument gives relative values of fluorescence at different wavelengths induced by the two-excitation sources. Lightinduced fluorescence has demonstrated successful crop health monitoring and plant nutritional stress detection capabilities. The spectral response of the plants has first been measured with an hyperspectral imager using laser-induced fluorescence. A tabletop imaging fluorometer based on flash lamp technology has also been designed to study the spatial distribution of fluorescence on plant leaves. For field based non-imaging system, LED technology is used as light source to induce fluorescence of the plant. The operational fluorescence system is based on ultraviolet and blue LED to induce fluorescence. Four narrow fluorescence bands centered on 440, 520, 690 and 740nm are detected. The instrument design includes a modular approach for light source and detector. It can accommodate as many as four different light sources and six bands of fluorescence detection. As part of the design for field application, the instrument is compatible with a mobile platform equipped with a GPS and data acquisition system. The current system developed by Telops/GAAP is configured for potato crops fluorescence measurement but can easily be adapted for other crops. This new instrument offers an effective and affordable solution for precision farming.

Mixture-fraction imaging at 1  kHz using femtosecond laser-induced fluorescence of krypton.

Science.gov (United States)

Richardson, Daniel R; Jiang, Naibo; Stauffer, Hans U; Kearney, Sean P; Roy, Sukesh; Gord, James R

2017-09-01

Femtosecond, two-photon-absorption laser-induced-fluorescence (TALIF) imaging measurements of krypton (Kr) are demonstrated to study mixing in gaseous flows. A measurement approach is presented in which observed Kr TALIF signals are 7 times stronger than the current state-of-the-art methodology. Fluorescence emission is compared for different gas pressures and excitation wavelengths, and the strongest fluorescence signals were observed when the excitation wavelength was tuned to 212.56 nm. Using this optimized excitation scheme, 1-kHz, single-laser-shot visualizations of unsteady flows and two-dimensional measurements of mixture fraction and scalar dissipation rate of a Kr-seeded jet are demonstrated.

Speciation of actinides in aqueous solution by time-resolved laser-induced fluorescence spectroscopy (TRLFS)

International Nuclear Information System (INIS)

Kimura, Takaumi; Kato, Yoshiharu; Meinrath, G.; Yoshida, Zenko; Choppin, G.R.

1995-01-01

Time-resolved laser-induced fluorescence spectroscopy (TRLFS) as a sensitive and selective method has been applied to the speciation of actinides in aqueous solution. Studies on hydrolysis and carbonate complexation of U(VI) and on determination of hydration number of Cm(III) are reported. (author)

Variability in surface antigen expression on neuroblastoma cells as revealed by monoclonal antibodies

International Nuclear Information System (INIS)

Malpas, J.S.; Kemshead, J.T.; Pritchard, J.; Greaves, M.F.

1982-01-01

In treatment programmes for neuroblastoma involving autologous bone marrow transplantation, a problem exists in the identification of small numbers of metastatic tumour cells present in the marrow aspirates. Reinfusion of tumour cells along with normal bone marrow may reseed the tumour within a patient who has received high dose chemotherapy. Formalin-induced fluorescence in neuroblastoma is a possible diagnostic aid, but this method has no therapeutic potential. Other methods of detecting tumour relying on gross physiological changes in the patient are not suitable for diagnosis of minimal metastatic disease. As an immunological approach to the problem, rabbit antisera to neuroblastoma have been raised but these reagents suffer from low titre after absorption to make them specific. The authors have used the technique of somatic cell hybridisation to raise monoclonal antibodies which bind to neuroblastoma cells and not to normal haemopoietic progenitors. A panel of such reagents to demonstrate heterogeneity in antigen expression amongst metastatic neuroblastoma cells was employed in a radioimmunoassay as diagnostic aid for this problem. (Auth.)

Two-color planar laser-induced fluorescence thermometry in aqueous solutions

International Nuclear Information System (INIS)

Robinson, G. Andrew; Lucht, Robert P.; Laurendeau, Normand M.

2008-01-01

We demonstrate a two-color planar laser-induced fluorescence technique for obtaining two-dimensional temperature images in water. For this method, a pulsed Nd:YAG laser at 532 nm excites a solution of temperature-sensitive rhodamine 560 and temperature-insensitive sulforhodamine 640. The resulting emissions are optically separated through filters and detected via a charged-couple device (CCD) camera system. A ratio of the two images yields temperature images independent of incident irradiance. An uncertainty in temperature of ±1.4 deg. C is established at the 95% confidence interval

Cytology specimens offer an effective alternative to formalin-fixed tissue as demonstrated by novel automated detection for ALK break-apart FISH testing and immunohistochemistry in lung adenocarcinoma.

Science.gov (United States)

Rosenblum, Frida; Hutchinson, Lloyd M; Garver, Joann; Woda, Bruce; Cosar, Ediz; Kurian, Elizabeth M

2014-11-01

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC). ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases). The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH. The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC. © 2014 American Cancer Society.

Two dimensional laser induced fluorescence in the gas phase: a spectroscopic tool for studying molecular spectroscopy and dynamics

Science.gov (United States)

Gascooke, Jason R.; Lawrance, Warren D.

2017-11-01

Two dimensional laser induced fluorescence (2D-LIF) extends the usual laser induced fluorescence technique by adding a second dimension, the wavelength at which excited states emit, thereby significantly enhancing the information that can be extracted. It allows overlapping absorption features, whether they arise from within the same molecule or from different molecules in a mixture, to be associated with their appropriate "parent" state and/or molecule. While the first gas phase version of the technique was published a decade ago, the technique is in its infancy, having been exploited by only a few groups to date. However, its potential in gas phase spectroscopy and dynamics is significant. In this article we provide an overview of the technique and illustrate its potential with examples, with a focus on those utilising high resolution in the dispersed fluorescence dimension.

Two-photon induced fluorescence of Cy5-DNA in buffer solution and on silver island films

International Nuclear Information System (INIS)

Lukomska, Joanna; Gryczynski, Ignacy; Malicka, Joanna; Makowiec, Slawomir; Lakowicz, Joseph R.; Gryczynski, Zygmunt

2005-01-01

We report the observation of a strong two-photon induced fluorescence emission of Cy5-DNA within the tunable range of a Ti:Sapphire laser. The estimated two-photon cross-section for Cy5-DNA of 400 GM is about 3.5-fold higher than it was reported for rhodamine B. The fundamental anisotropies of Cy5-DNA are close to the theoretical limits of 2/5 and 4/7 for one- and two-photon excitation, respectively. We also observed an enhanced two-photon induced fluorescence (TPIF) of Cy5-DNA deposited on silver island films (SIFs). In the presence of SIFs, the TPIF is about 100-fold brighter. The brightness increase of Cy5-DNA TPIF near SIFs is mostly due to enhanced local field

Radioisotope induced X-ray fluorescence analysis of cereal grains and flour

International Nuclear Information System (INIS)

Toeroek, Sz.; Szoekefalvi-Nagy, Z.

1982-06-01

Radioisotope-induced X-ray fluorescence analysis is a rather simple and easy method for investigating ashed plant material. In order to reduce matrix effects thin samples of 2 mg/cm 2 are analysed to obtain a reasonable compromise between maximum sensitivity and the lowest possible absorption effects. Concentrations are determined by standard addition method. An accuracy of 6-8% can be achieved. As an application analytical results are given for whole grains of several sorts of wheat. (author)

Effect of Formalin on the Hatching Rate of eggs and Survival of ...

African Journals Online (AJOL)

Michael Horsfall

1, and 1000 mgl-1 of formalin resulted in total egg mortality (0% hatching rate). In the definitive ... treatment of fish disease, particularly fungi, as in this study, where it effectively reduced fungi on eggs and larvae of ... salmon held for spawning).

Study of the inflammatory process induced by injection of carrageenan or formalin in the rat temporomandibular joint Estudo do processo inflamatório induzido pela injeção de carragenina ou de formalina na articulação temporomandibular de ratos

OpenAIRE

Alan Cruvinel Goulart; Francisco Antônio dos Santos Correia; Suzana Cantanhede Orsini Machado de Sousa; João Gualberto de Cerqueira Luz

2005-01-01

The aim of this study was to evaluate the effects of the injection of two phlogistic agents, carrageenan and formalin, in the rat TMJ, and the inflammatory process induced by these substances. In this study, a total of 45 adult rats were distributed in two experimental groups and a control group. The animals were sacrificed after three hours, 24 hours, three days, seven days, and 15 days after a single injection of each substance. Histological data initially demonstrated an inflammatory proce...

A LabVIEW-Based Virtual Instrument System for Laser-Induced Fluorescence Spectroscopy.

Science.gov (United States)

Wu, Qijun; Wang, Lufei; Zu, Lily

2011-01-01

We report the design and operation of a Virtual Instrument (VI) system based on LabVIEW 2009 for laser-induced fluorescence experiments. This system achieves synchronous control of equipment and acquisition of real-time fluorescence data communicating with a single computer via GPIB, USB, RS232, and parallel ports. The reported VI system can also accomplish data display, saving, and analysis, and printing the results. The VI system performs sequences of operations automatically, and this system has been successfully applied to obtain the excitation and dispersion spectra of α-methylnaphthalene. The reported VI system opens up new possibilities for researchers and increases the efficiency and precision of experiments. The design and operation of the VI system are described in detail in this paper, and the advantages that this system can provide are highlighted.

Laser-induced fluorescence with an OPO system. Part II: direct determination of lead content in seawater by electrothermal atomization-laser-excited atomic fluorescence (ETA-LEAF).

Science.gov (United States)

Le Bihan, A; Lijour, Y; Giamarchi, P; Burel-Deschamps, L; Stephan, L

2003-03-01

Fluorescence was induced by coupling a laser with an optical parametric oscillator (OPO) to develop an analytical method for the direct determination of lead content, at ultra-trace level, in seawater by electrothermal atomization-laser-excited atomic fluorescence (ETA-LEAF). The optimization of atomization conditions, laser pulse energy, and mainly temporal parameters allowed us to reach a 3 fg detection limit (0.3 ng L(-1)) despite the low repetition rate of the device. The expected error on predicted concentrations of lead, at trace levels, in seawater was below 15%.

A rapid technique for analysis of formalin-fixed, paraffin-embedded tissues by fluorescent in situ hybridization with alpha-satellite probes

Directory of Open Access Journals (Sweden)

Nilce Barril

1998-12-01

Full Text Available We describe a rapid procedure for preparing archival tissues for interphase FISH analysis. The present protocol differs from others previously described because it allows the obtention of nuclei in satisfactory number and quality without using special equipments, adhesive-treated slides or solutions for chromatin decondensation. The method is of low cost and useful for retrospective analyses of formalin-fixed, paraffin-embedded samples.Descrevemos aqui um procedimento rápido para obtenção de núcleos interfásicos a partir de amostras arquivadas que podem ser utilizados para análise citogenética através da técnica de FISH. Este procedimento difere de outros previamente descritos porque permite a obtenção de núcleos em número e qualidade satisfatórios sem a utilização de equipamentos ou lâminas especiais e soluções para descondensação da cromatina. O método é de baixo custo e possibilita estudos retrospectivos de tecidos fixados em formol e emblocados em parafina.

Recent results of synchrotron radiation induced total reflection X-ray fluorescence analysis at HASYLAB, beamline L

Energy Technology Data Exchange (ETDEWEB)

Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria)]. E-mail: streli@ati.ac.at; Pepponi, G. [ITC-irst, Povo (Italy); Wobrauschek, P. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Jokubonis, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Falkenberg, G. [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22603 Hamburg (Germany); Zaray, G. [Institute of Inorganic and Applied Chemistry, 3 EOTVOS Univ, Budapest (Hungary); Broekaert, J. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Fittschen, U. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Peschel, B. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)

2006-11-15

At the Hamburger Synchrotronstrahlungslabor (HASYLAB), Beamline L, a vacuum chamber for synchrotron radiation-induced total reflection X-ray fluorescence analysis, is now available which can easily be installed using the adjustment components for microanalysis present at this beamline. The detector is now in the final version of a Vortex silicon drift detector with 50-mm{sup 2} active area from Radiant Detector Technologies. With the Ni/C multilayer monochromator set to 17 keV extrapolated detection limits of 8 fg were obtained using the 50-mm{sup 2} silicon drift detector with 1000 s live time on a sample containing 100 pg of Ni. Various applications are presented, especially of samples which are available in very small amounts: As synchrotron radiation-induced total reflection X-ray fluorescence analysis is much more sensitive than tube-excited total reflection X-ray fluorescence analysis, the sampling time of aerosol samples can be diminished, resulting in a more precise time resolution of atmospheric events. Aerosols, directly sampled on Si reflectors in an impactor were investigated. A further application was the determination of contamination elements in a slurry of high-purity Al{sub 2}O{sub 3}. No digestion is required; the sample is pipetted and dried before analysis. A comparison with laboratory total reflection X-ray fluorescence analysis showed the higher sensitivity of synchrotron radiation-induced total reflection X-ray fluorescence analysis, more contamination elements could be detected. Using the Si-111 crystal monochromator also available at beamline L, XANES measurements to determine the chemical state were performed. This is only possible with lower sensitivity as the flux transmitted by the crystal monochromator is about a factor of 100 lower than that transmitted by the multilayer monochromator. Preliminary results of X-ray absorption near-edge structure measurements for As in xylem sap from cucumber plants fed with As(III) and As(V) are

Recent results of synchrotron radiation induced total reflection X-ray fluorescence analysis at HASYLAB, beamline L

International Nuclear Information System (INIS)

Streli, C.; Pepponi, G.; Wobrauschek, P.; Jokubonis, C.; Falkenberg, G.; Zaray, G.; Broekaert, J.; Fittschen, U.; Peschel, B.

2006-01-01

At the Hamburger Synchrotronstrahlungslabor (HASYLAB), Beamline L, a vacuum chamber for synchrotron radiation-induced total reflection X-ray fluorescence analysis, is now available which can easily be installed using the adjustment components for microanalysis present at this beamline. The detector is now in the final version of a Vortex silicon drift detector with 50-mm 2 active area from Radiant Detector Technologies. With the Ni/C multilayer monochromator set to 17 keV extrapolated detection limits of 8 fg were obtained using the 50-mm 2 silicon drift detector with 1000 s live time on a sample containing 100 pg of Ni. Various applications are presented, especially of samples which are available in very small amounts: As synchrotron radiation-induced total reflection X-ray fluorescence analysis is much more sensitive than tube-excited total reflection X-ray fluorescence analysis, the sampling time of aerosol samples can be diminished, resulting in a more precise time resolution of atmospheric events. Aerosols, directly sampled on Si reflectors in an impactor were investigated. A further application was the determination of contamination elements in a slurry of high-purity Al 2 O 3 . No digestion is required; the sample is pipetted and dried before analysis. A comparison with laboratory total reflection X-ray fluorescence analysis showed the higher sensitivity of synchrotron radiation-induced total reflection X-ray fluorescence analysis, more contamination elements could be detected. Using the Si-111 crystal monochromator also available at beamline L, XANES measurements to determine the chemical state were performed. This is only possible with lower sensitivity as the flux transmitted by the crystal monochromator is about a factor of 100 lower than that transmitted by the multilayer monochromator. Preliminary results of X-ray absorption near-edge structure measurements for As in xylem sap from cucumber plants fed with As(III) and As(V) are reported. Detection

Revealing the Molecular Portrait of Triple Negative Breast Tumors in an Understudied Population through Omics Analysis of Formalin-Fixed and Paraffin-Embedded Tissues.

Science.gov (United States)

Vaca-Paniagua, Felipe; Alvarez-Gomez, Rosa María; Maldonado-Martínez, Hector Aquiles; Pérez-Plasencia, Carlos; Fragoso-Ontiveros, Veronica; Lasa-Gonsebatt, Federico; Herrera, Luis Alonso; Cantú, David; Bargallo-Rocha, Enrique; Mohar, Alejandro; Durand, Geoffroy; Forey, Nathalie; Voegele, Catherine; Vallée, Maxime; Le Calvez-Kelm, Florence; McKay, James; Ardin, Maude; Villar, Stéphanie; Zavadil, Jiri; Olivier, Magali

2015-01-01

Triple negative breast cancer (TNBC), defined by the lack of expression of the estrogen receptor, progesterone receptor and human epidermal receptor 2, is an aggressive form of breast cancer that is more prevalent in certain populations, in particular in low- and middle-income regions. The detailed molecular features of TNBC in these regions remain unexplored as samples are mostly accessible as formalin-fixed paraffin embedded (FFPE) archived tissues, a challenging material for advanced genomic and transcriptomic studies. Using dedicated reagents and analysis pipelines, we performed whole exome sequencing and miRNA and mRNA profiling of 12 FFPE tumor tissues collected from pathological archives in Mexico. Sequencing analyses of the tumor tissues and their blood pairs identified TP53 and RB1 genes as the most frequently mutated genes, with a somatic mutation load of 1.7 mutations/exome Mb on average. Transcriptional analyses revealed an overexpression of growth-promoting signals (EGFR, PDGFR, VEGF, PIK3CA, FOXM1), a repression of cell cycle control pathways (TP53, RB1), a deregulation of DNA-repair pathways, and alterations in epigenetic modifiers through miRNA:mRNA network de-regulation. The molecular programs identified were typical of those described in basal-like tumors in other populations. This work demonstrates the feasibility of using archived clinical samples for advanced integrated genomics analyses. It thus opens up opportunities for investigating molecular features of tumors from regions where only FFPE tissues are available, allowing retrospective studies on the search for treatment strategies or on the exploration of the geographic diversity of breast cancer.

New method for estimating clustering of DNA lesions induced by physical/chemical mutagens using fluorescence anisotropy.

Science.gov (United States)

Akamatsu, Ken; Shikazono, Naoya; Saito, Takeshi

2017-11-01

We have developed a new method for estimating the localization of DNA damage such as apurinic/apyrimidinic sites (APs) on DNA using fluorescence anisotropy. This method is aimed at characterizing clustered DNA damage produced by DNA-damaging agents such as ionizing radiation and genotoxic chemicals. A fluorescent probe with an aminooxy group (AlexaFluor488) was used to label APs. We prepared a pUC19 plasmid with APs by heating under acidic conditions as a model for damaged DNA, and subsequently labeled the APs. We found that the observed fluorescence anisotropy (r obs ) decreases as averaged AP density (λ AP : number of APs per base pair) increases due to homo-FRET, and that the APs were randomly distributed. We applied this method to three DNA-damaging agents, 60 Co γ-rays, methyl methanesulfonate (MMS), and neocarzinostatin (NCS). We found that r obs -λ AP relationships differed significantly between MMS and NCS. At low AP density (λ AP  < 0.001), the APs induced by MMS seemed to not be closely distributed, whereas those induced by NCS were remarkably clustered. In contrast, the AP clustering induced by 60 Co γ-rays was similar to, but potentially more likely to occur than, random distribution. This simple method can be used to estimate mutagenicity of ionizing radiation and genotoxic chemicals. Copyright © 2017 Elsevier Inc. All rights reserved.

Teaching laser-induced fluorescence of plant leaves

Science.gov (United States)

Lenk, Sándor; Gádoros, Patrik; Kocsányi, László; Barócsi, Attila

2016-11-01

Plants convert carbon dioxide into sugars using the energy of sunlight. Absorbed light unused for conversion is dissipated primarily as heat with a small fraction re-emitted as fluorescence at longer wavelengths. One can use the latter to estimate photosynthetic activity. The illumination of intact leaves with strong light after keeping them in dark for tens of minutes results in a rapid increase followed by a slow decay of fluorescence emission from the fluorophore chlorophyll-a, called the Kautsky effect. This paper describes a laboratory practice that introduces students of physics or engineering into this research field. It begins with the spectral measurement of the fluorescence emitted by a plant leaf upon UV excitation. Then it focuses on the red and far-red components of the fluorescence emission spectrum characteristic to the chlorophyll-a molecule and presents an inexpensive demonstration of the Kautsky effect. As researchers use more complex measurement techniques and tools, the practice ends up with the demonstration of an intelligent fluorosensor, a compact tool developed for plant physiological research and horticulture applications together with a brief interpretation of some important fluorescence parameters.

Teaching laser-induced fluorescence of plant leaves

International Nuclear Information System (INIS)

Lenk, Sándor; Gádoros, Patrik; Kocsányi, László; Barócsi, Attila

2016-01-01

Plants convert carbon dioxide into sugars using the energy of sunlight. Absorbed light unused for conversion is dissipated primarily as heat with a small fraction re-emitted as fluorescence at longer wavelengths. One can use the latter to estimate photosynthetic activity. The illumination of intact leaves with strong light after keeping them in dark for tens of minutes results in a rapid increase followed by a slow decay of fluorescence emission from the fluorophore chlorophyll -a , called the Kautsky effect. This paper describes a laboratory practice that introduces students of physics or engineering into this research field. It begins with the spectral measurement of the fluorescence emitted by a plant leaf upon UV excitation. Then it focuses on the red and far-red components of the fluorescence emission spectrum characteristic to the chlorophyll -a molecule and presents an inexpensive demonstration of the Kautsky effect. As researchers use more complex measurement techniques and tools, the practice ends up with the demonstration of an intelligent fluorosensor, a compact tool developed for plant physiological research and horticulture applications together with a brief interpretation of some important fluorescence parameters. (paper)

Probing Contaminant-Induced Alterations in Chlorophyll Fluorescence by AC-Dielectrophoresis-Based 2D-Algal Array

Directory of Open Access Journals (Sweden)

Coralie Siebman

2018-02-01

Full Text Available The investigation of contaminant impact on algae requires rapid and reliable cell collection and optical detection. The capability of alternative current (AC dielectrophoresis (DEP collection of whole cell arrays with combined fluorescence microscopy detection to follow the alterations of chlorophyll fluorescence during environmental contaminant exposure was explored. The application of an AC-field of 100 V cm−1, 100 Hz for 30 min to capture and immobilize the cells of green alga Chlamydomonas reinhardtii in two-dimensional (2D arrays does not induce changes in chlorophyll fluorescence. The results demonstrate that DEP-based 2D-arrays allow non-invasive detection of chlorophyll fluorescence change upon exposure to high concentrations of copper oxide nanoparticles and ionic copper. These results were in agreement with data obtained by flow cytometry used as a comparative method. The tool was also applied to follow the effect of a number of ubiquitous contaminants such as inorganic mercury, methylmercury, and diuron. However, a statistically significant short-term effect was observed only for mercury. Overall, DEP-based 2D-arrays of algal cells with fluorescence detection appear to be suitable for stain-free probing the effects on the photosynthetic microorganisms in highly polluted environment.

Utilization of Photochemically Induced Fluorescence Detection for HPLC Determination of Genotoxic Impurities in the Vortioxetine Manufacturing Process.

Science.gov (United States)

Douša, Michal; Doubský, Jan; Srbek, Jan

2016-07-01

An analytical reversed-phase high-performance liquid chromatography (HPLC) method for the detection and quantitative determination of two genotoxic impurities at ppm level present in the vortioxetine manufacturing process is described. Applying the concept of threshold of toxicological concern, a limit of 75 ppm each for both genotoxic impurities was calculated based on the maximum daily dose of active pharmaceutical ingredients. The novel reversed-phase HPLC method with photochemically induced fluorescence detection was developed on XSELECT Charged Surface Hybrid Phenyl-Hexyl column using the mobile phase consisted a mixture of 10 mM ammonium formate pH 3.0 and acetonitrile. The elution was performed using an isocratic composition of 48:52 (v/v) at a flow rate of 1.0 mL/min. The photochemically induced fluorescence detection is based on the use of UV irradiation at 254 nm through measuring the fluorescence intensity at 300 nm and an excitation wavelength of 272 nm to produce fluorescent derivatives of both genotoxic impurities. The online photochemical conversion and detection is easily accomplished for two expected genotoxic impurities and provides a sufficiently low limit detection and quantification for the target analysis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A vacuum-UV laser-induced fluorescence experiment for measurement of rotationally and vibrationally excited H2

International Nuclear Information System (INIS)

Vankan, P.; Heil, S.B.S.; Mazouffre, S.; Engeln, R.; Schram, D.C.; Doebele, H.F.

2004-01-01

An experimental setup is built to detect spatially resolved rovibrationally excited hydrogen molecules via laser-induced fluorescence. To excite the hydrogen molecules, laser radiation is produced in the vacuum UV part of the spectrum. The laser radiation is tunable between 120 nm and 230 nm and has a bandwith of 0.15 cm -1 . The wavelength of the laser radiation is calibrated by simultaneous recording of the two-photon laser induced fluorescence spectrum of nitric oxide. The excited hydrogen populations are calibrated on the basis of coherent anti-Stokes Raman scattering measurements. A population distribution is measured in the shock region of a pure hydrogen plasma expansion. The higher rotational levels (J>5) show overpopulation compared to a Boltzmann distribution determined from the lower rotational levels (J≤5)

Study of the inflammatory process induced by injection of carrageenan or formalin in the rat temporomandibular joint Estudo do processo inflamatório induzido pela injeção de carragenina ou de formalina na articulação temporomandibular de ratos

Directory of Open Access Journals (Sweden)

Alan Cruvinel Goulart

2005-06-01

Full Text Available The aim of this study was to evaluate the effects of the injection of two phlogistic agents, carrageenan and formalin, in the rat TMJ, and the inflammatory process induced by these substances. In this study, a total of 45 adult rats were distributed in two experimental groups and a control group. The animals were sacrificed after three hours, 24 hours, three days, seven days, and 15 days after a single injection of each substance. Histological data initially demonstrated an inflammatory process represented by acute infiltration, which later became mixed, and finally chronic in both experimental groups. Hyperplasia of the synovial membrane was observed after three days, being intense at seven days, and present after 15 days only in the formalin group. Local saline injection in the control group caused no inflammatory reaction. It was concluded that a single local injection of carrageenan or formalin was enough to induce inflammatory reaction in the TMJ and periarticular soft tissues, and that the resulting processes were similar, but more persistent in the formalin group.O objetivo deste trabalho foi avaliar os efeitos da injeção de dois agentes flogísticos, ou seja, carragenina ou formalina, na ATM do rato, e a evolução do quadro inflamatório provocado por essas substâncias. Foram utilizados 45 ratos, divididos em dois grupos experimentais e um grupo controle. Os animais foram sacrificados em lotes de três de cada grupo após três horas, 24 horas, três dias, sete dias e 15 dias da injeção. Histologicamente a reação inflamatória em ambos os grupos experimentais iniciou-se com infiltrado inflamatório agudo, tornando-se misto e depois crônico. Sinais de hiperplasia da membrana sinovial foram observados aos três dias, intensos aos sete dias, estando presentes aos 15 dias somente no grupo da formalina. A injeção de solução salina (grupo controle não provocou reação inflamatória. No presente trabalho foi concluído que uma

Identification of the pigment responsible for the blue fluorescence band in the laser induced fluorescence (LIF) spectra of green plants, and the potential use of this band in remotely estimating rates of photosynthesis

International Nuclear Information System (INIS)

Chappelle, E.W.; McMurtrey, J.E. III; Kim, M.S.

1991-01-01

The laser-induced fluorescence (LIF) of vegetation is being investigated in this laboratory for use as a technique for the remote detection of the effects of environmental stress upon vegetation, as well as for plant identification. The fluorescence band with a maximum at 440 nm, in conjunction with the chlorophyll bands with maxima at 685 and 740 nm, has been found to be a critical band in the development of algorithms for detecting stress, and identifying plant types. The identification of the plant constituent responsible for this band is vital to understanding the mechanism underlying its fluorescence changes in response to environmental and physiological changes. The identification was achieved as follows: The laser induced fluorescence (LIF) spectra of pure plant pigments were determined. Fluorescence bands with maxima at 420 nm, 440 nm, 490 nm, and 525 nm were observed for vitamin K 1 , reduced nicotinamide adenine dinucleotide (NADPH), beta-carotene, and riboflavin, respectively. The LIF spectra of water extracts and acetone extracts of clover leaves were also measured. It was found that the blue fluorescence band was associated with the water extract. NADPH which is a water-soluble compound, and the water extract of clover had no fluorescence after oxidation by potassium ferricyanide, while the fluorescence of water insoluble vitamin K 1 was unchanged by the oxidizing agent. It was also found that the absorption maximum of NADPH was the same as the absorption maximum of the aqueous extract of clover. The above findings indicated that the compound responsible for the blue fluorescence at 440 nm is in the reduced state and is water-soluble. It was concluded that NADPH was responsible for the blue fluorescence at 440 nm. The strong linear relationship between the fluorescence at 440 nm and the rate of photosynthesis suggests the possible use of LIF measurements in the remote estimation of photosynthetic rates. (author)

Nanoantenna array-induced fluorescence enhancement and reduced lifetimes

DEFF Research Database (Denmark)

Bakker, R. M.; Drachev, V. P.; Liu, Z.

2008-01-01

Enhanced fluorescence is observed from dye molecules interacting with optical nanoantenna arrays. Elliptical gold dimers form individual nanoantennae with tunable plasmon resonances depending upon the geometry of the two particles and the size of the gap between them. A fluorescent dye, Rhodamine...... 800, is uniformly embedded in a dielectric host that coats the nanoantennae. The nanoantennae act to enhance the dye absorption. In turn, emission from the dye drives the plasmon resonance of the antennae; the nanoantennae act to enhance the fluorescence signal and change the angular distribution...... of emission. These effects depend upon the overlap of the plasmon resonance with the excitation wavelength and the fluorescence emission band. A decreased fluorescence lifetime is observed along with highly polarized emission that displays the characteristics of the nanoantenna's dipole mode. Being able...

Serum Protein Profile Study of Clinical Samples Using High Performance Liquid Chromatography-Laser Induced Fluorescence

DEFF Research Database (Denmark)

Karemore, Gopal Raghunath; Ukendt, Sujatha; Rai, Lavanya

2009-01-01

The serum protein profiles of normal subjects, patients diagnosed with cervical cancer, and oral cancer were recorded using High Performance Liquid Chromatography combined with Laser Induced Fluorescence detection (HPLC-LIF). Serum protein profiles of the above three classes were tested for estab...

Laser induced fluorescence in atmospheric pressure discharges

International Nuclear Information System (INIS)

Dilecce, G; De Benedictis, S; Martini, L M; Tosi, P; Scotoni, M

2015-01-01

This paper offers an outline of laser induced fluorescence (LIF) diagnostics and practical recommendations for its use in atmospheric pressure discharges. LIF principles, technical requirements and rationalization of experimental outcomes by modelling are addressed. Important issues that are particularly relevant to small scale, spatially inhomogeneous discharges, like plasma-jets, are emphasized. For the first time, all collision processes and the spatial non-homogeneity of the laser beam are together accounted for in the LIF model. Saturation characteristics are discussed and used for the assessment of model parameters. A calibration procedure is discussed and implemented. Gas temperature measurements by LIF are also addressed. The whole description of the technique is given, without loss of generality, through the example of its application to the OH radical. Notes on other diatomic radicals, CH, NO and CN, are given along the paper. Some results in a RF plasma-jet are presented as an example of application in a discharge system where all the concepts developed in the paper are applied. (paper)

Effects of sublethal concentrations of formalin on weight gain in the ...

African Journals Online (AJOL)

The African Catfish, Clarias gariepinus, was exposed to various sublethal concentrations (25.0, 12.50, 6.25, 3.125, 1.56 and 0.0 mgl-1) of formalin to investigate their effects on the weight gain of the fish. Decrease in weight gain, directly proportional to the toxicant concentration, was observed in fish exposed to ...

The Regional Differences of Gpp Estimation by Solar Induced Fluorescence

Science.gov (United States)

Wang, X.; Lu, S.

2018-04-01

Estimating gross primary productivity (GPP) at large spatial scales is important for studying the global carbon cycle and global climate change. In this study, the relationship between solar-induced chlorophyll fluorescence (SIF) and GPP is analysed in different levels of annual average temperature and annual total precipitation respectively using simple linear regression analysis. The results showed high correlation between SIF and GPP, when the area satisfied annual average temperature in the range of -5 °C to 15 °C and the annual total precipitation is higher than 200 mm. These results can provide a basis for future estimation of GPP research.

Portable Fluorescence Imaging System for Hypersonic Flow Facilities

Science.gov (United States)

Wilkes, J. A.; Alderfer, D. W.; Jones, S. B.; Danehy, P. M.

2003-01-01

A portable fluorescence imaging system has been developed for use in NASA Langley s hypersonic wind tunnels. The system has been applied to a small-scale free jet flow. Two-dimensional images were taken of the flow out of a nozzle into a low-pressure test section using the portable planar laser-induced fluorescence system. Images were taken from the center of the jet at various test section pressures, showing the formation of a barrel shock at low pressures, transitioning to a turbulent jet at high pressures. A spanwise scan through the jet at constant pressure reveals the three-dimensional structure of the flow. Future capabilities of the system for making measurements in large-scale hypersonic wind tunnel facilities are discussed.

Fluorescent Protein-Based Ca2+ Sensor Reveals Global, Divalent Cation-Dependent Conformational Changes in Cardiac Troponin C.

Directory of Open Access Journals (Sweden)

Myriam A Badr

Full Text Available Cardiac troponin C (cTnC is a key effector in cardiac muscle excitation-contraction coupling as the Ca2+ sensing subunit responsible for controlling contraction. In this study, we generated several FRET sensors for divalent cations based on cTnC flanked by a donor fluorescent protein (CFP and an acceptor fluorescent protein (YFP. The sensors report Ca2+ and Mg2+ binding, and relay global structural information about the structural relationship between cTnC's N- and C-domains. The sensors were first characterized using end point titrations to decipher the response to Ca2+ binding in the presence or absence of Mg2+. The sensor that exhibited the largest responses in end point titrations, CTV-TnC, (Cerulean, TnC, and Venus was characterized more extensively. Most of the divalent cation-dependent FRET signal originates from the high affinity C-terminal EF hands. CTV-TnC reconstitutes into skinned fiber preparations indicating proper assembly of troponin complex, with only ~0.2 pCa unit rightward shift of Ca2+-sensitive force development compared to WT-cTnC. Affinity of CTV-TnC for divalent cations is in agreement with known values for WT-cTnC. Analytical ultracentrifugation indicates that CTV-TnC undergoes compaction as divalent cations bind. C-terminal sites induce ion-specific (Ca2+ versus Mg2+ conformational changes in cTnC. Our data also provide support for the presence of additional, non-EF-hand sites on cTnC for Mg2+ binding. In conclusion, we successfully generated a novel FRET-Ca2+ sensor based on full length cTnC with a variety of cellular applications. Our sensor reveals global structural information about cTnC upon divalent cation binding.

Metal Cations Induced alpha beta-BChl a Heterogeneity in LH1 as Revealed by Temperature-Dependent Fluorescence Splitting

NARCIS (Netherlands)

Ma, Fei; Yu, Long-Jiang; Llansola-Portoles, Manuel J.; Robert, Bruno; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

2017-01-01

Two spectral forms of the core light-harvesting complex (LH1) of the purple bacterium Thermochromatium (Tch.) tepidum, the native Ca2+-binding and the Ba2+-substituted one, exhibit different fluorescence (FL) emission spectra at low temperature (T). While Ca-LH1 exhibits one emission band, an

Surface poisoning in the nucleation and growth of palladium atomic layer deposition with Pd(hfac){sub 2} and formalin

Energy Technology Data Exchange (ETDEWEB)

Goldstein, D.N. [Department of Chemistry and Biochemistry, University of Colorado, 215 UCB, Boulder, CO 80309 (United States); George, S.M., E-mail: Steven.George@Colorado.Edu [Department of Chemistry and Biochemistry, University of Colorado, 215 UCB, Boulder, CO 80309 (United States); Department of Chemical and Biological Engineering, University of Colorado, 424 UCB, Boulder, CO (United States)

2011-06-01

Palladium (Pd) atomic layer deposition (ALD) can be performed with Pd(hfac){sub 2} (hfac = hexafluoroacetyl-acetone) and formalin as the reactants. For Pd ALD on oxide surfaces, the nucleation of Pd ALD has been observed to require between 20 and 100 ALD cycles. To understand the long nucleation periods, this study explored the surface reactions occurring during Pd ALD nucleation and growth on hydroxylated Al{sub 2}O{sub 3} substrates. In situ Fourier transform infrared (FTIR) spectroscopy on high surface area nanopowders was used to observe the surface species. The adsorption of Pd(hfac){sub 2} on hydroxylated Al{sub 2}O{sub 3} substrates was found to yield both Pd(hfac)* and Al(hfac)* surface species. The identity of the Al(hfac)* species was confirmed by separate FTIR studies of hfacH adsorption on the hydroxylated Al{sub 2}O{sub 3} substrates. Isothermal loss of the Al(hfac)* species revealed second-order kinetics at 448-523 K with an activation barrier of E{sub d} = 39.4 kcal/mol. The lack of correlation between Al(hfac)* and AlOH* species during the loss of Al(hfac)* species suggested that the Al(hfac)* species may desorb as Al(hfac){sub 3}. After Pd(hfac){sub 2} exposure and the subsequent formalin exposure on hydroxylated Al{sub 2}O{sub 3} substrates, only hfac ligands from Pd(hfac)* species were removed from the surface. In addition, the formalin exposure added formate species. The Al(hfac)* species was identified as the cause of the long nucleation period because Al(hfac)* behaves as a site blocker. The surface poisoning by Al(hfac)* species was corroborated by adsorbing hfacH prior to the Pd(hfac){sub 2} exposures. The amount of Pd(hfac)* species after Pd(hfac){sub 2} exposures decreased progressively versus the previous hfacH exposure. Pd ALD occurred gradually during the subsequent Pd ALD cycles as the Al(hfac)* species were slowly removed from the Al{sub 2}O{sub 3} surface. Ex situ transmission electron microscopy analysis revealed Pd nanoclusters

Ratiometric, single-dye, pH-sensitive inhibited laser-induced fluorescence for the characterization of mixing and mass transfer

Science.gov (United States)

Lacassagne, Tom; Simoëns, Serge; El Hajem, Mahmoud; Champagne, Jean-Yves

2018-01-01

Inhibited planar laser-induced fluorescence (I-PLIF) techniques are widely used for heat and mass transfer studies in fluid mechanics. They allow the visualization of instantaneous two-dimensional field of a passive or reactive scalar, providing that this scalar acts as an inhibitor to the fluorescence of a specific molecule, and that this molecule is homogeneously mixed in the fluid at a known concentration. Local scalar values are deduced from fluorescence recordings thanks to preliminary calibration procedure. When confronted with non-optically thin systems, however, the knowledge of the excitation intensity distribution in the region of interest is also required, and this information is most of the time hard to obtain. To overcome that problem, two-color ratiometric PLIF techniques ( {I}^ {r}-PLIF) have been developed. In these methods, the ratio of two different fluorescence wavelengths triggered by the same excitation is used as an indicator of the scalar value. Such techniques have been used for temperature measurements in several studies but never, to the author's knowledge, for pH tracking and acid-base mixing, despite the frequent use of the one-color version in mass transfer studies. In the present work, a ratiometric pH-sensitive-inhibited PLIF technique ( {I}_ {pH}^ {r}-PLIF) using fluorescein sodium as a single dye and applicable to complex geometries and flows is developed. Theoretical considerations show that the ratio of the two-color fluorescence intensities should only depend on the dye's spectral quantum yield, itself pH-dependent. A detailed spectrofluorimetric study of fluorescein reveals that this ratio strictly increases with the pH for two well-chosen spectral bands (fluorescence colors). A similar trend is found when using sCmos cameras equipped with optical filters to record fluorescence signals. The method is then experimented on a test flow, a turbulent acidic jet injected in an initially pH-neutral volume of fluid. The results obtained

The influence of PAH concentration and distribution on real-time in situ measurements of petroleum products in soils using laser induced fluorescence

International Nuclear Information System (INIS)

Douglas, G.S.; Lieberman, S.H.; McGinnis, W.C.; Knowles, D.; Peven, C.

1995-01-01

Real-time laser induced fluorescence (LIF) in situ measurements of soil samples provide a reliable and cost-effective screening tool for hydrocarbon site assessments. The site characterization and analysis penetrometer system (SCAPS), is a truck-mounted cone penetrometer probe modified with a sapphire window and connected to a laser by fiber optics. The pulsed nitrogen laser 337-nm excitation source induces fluorescence in polynuclear aromatic hydrocarbons (PAHs), which are present in petroleum products. The fluorescence response of these compounds is measured with a fluorometer. The SCAPS can provide continuous hydrocarbon screening measurements to soil depths greater than 100 feet. Discrete soil samples collected from the SCAPS boreholes were extracted and analyzed for total petroleum hydrocarbons (TPH), by gas chromatography with flame ionization detection (GC/FID), and 16 parent and over 100 alkyl substituted PAH compounds by gas chromatography with mass spectrometry detection (GC/MS). This method provides a basis for evaluating the relationship between TPH and PAH concentrations in the soil samples and laser induced fluorescence measurements from the soil borings

Laser Induced Fluorescence of Helium Ions in a Helicon Plasma

Science.gov (United States)

Compton, C. S.; Biloui, C.; Hardin, R. A.; Keesee, A. M.; Scime, E. E.; Boivin, R.

2003-10-01

The lack of a suitable Laser Induced Fluorescence (LIF) scheme for helium ions at visible wavelengths has prevented LIF from being employed in helium plasmas for measurements of ion temperature and bulk ion flow speeds. In this work, we will discuss our attempts to perform LIF of helium ions in a helicon source plasma using an infrared, tunable diode laser operating at 1012.36 nm. The infrared transition corresponds to excitation from the n = 4 level (4f ^2F) to the n = 5 (5g ^2G) level of singly ionized helium and therefore requires substantial electron temperatures (> 10 eV) to maintain an adequate ion population in the n = 4 state. Calculations using a steady state coronal model predict that the n = 4 state population will be 25% larger than the n = 5 population for our experimental conditions. The fluorescence decay from the n = 5 (5f ^2F) level of singly ionized helium level to the n = 3 (3d ^2D) level at 320.31 nm is monitored as the diode laser is swept through 10 GHz around the 1012.36 nm line. Note that the fluorescence emission requires a collisionally coupled transition between two different n = 5 quantum states. We will also present measurements of the emission intensities of both the 1012.36 nm and the 320.31 nm lines as a function of source neutral pressure, rf power, and plasma density. This work supported by the U.S. DoE EPSCoR Lab Partnership Program.

A simple procedure for the extraction of DNA from long-term formalin-preserved brain tissues for the detection of EBV by PCR.

Science.gov (United States)

Hassani, Asma; Khan, Gulfaraz

2015-12-01

Long-term formalin fixed brain tissues are potentially an important source of material for molecular studies. Ironically, very few protocols have been published describing DNA extraction from such material for use in PCR analysis. In our attempt to investigate the role of Epstein-Barr virus (EBV) in the pathogenesis of multiple sclerosis (MS), extracting PCR quality DNA from brain samples fixed in formalin for 2-22 years, proved to be very difficult and challenging. As expected, DNA extracted from these samples was not only of poor quality and quantity, but more importantly, it was frequently found to be non-amplifiable due to the presence of PCR inhibitors. Here, we describe a simple and reproducible procedure for extracting DNA using a modified proteinase K and phenol-chloroform methodology. Central to this protocol is the thorough pre-digestion washing of the tissues in PBS, extensive digestion with proteinase K in low SDS containing buffer, and using low NaCl concentration during DNA precipitation. The optimized protocol was used in extracting DNA from meninges of 26 MS and 6 non-MS cases. Although the quality of DNA from these samples was generally poor, small size amplicons (100-200 nucleotides) of the house-keeping gene, β-globin could be reliably amplified from all the cases. PCR for EBV revealed positivity in 35% (9/26) MS cases, but 0/6 non-MS cases. These findings indicate that the method described here is suitable for PCR detection of viral sequences in long-term formalin persevered brain tissues. Our findings also support a possible role for EBV in the pathogenesis of MS. Copyright © 2015 Elsevier Inc. All rights reserved.

Simultaneous measurement of amyloid fibril formation by dynamic light scattering and fluorescence reveals complex aggregation kinetics.

Directory of Open Access Journals (Sweden)

Aaron M Streets

Full Text Available An apparatus that combines dynamic light scattering and Thioflavin T fluorescence detection is used to simultaneously probe fibril formation in polyglutamine peptides, the aggregating subunit associated with Huntington's disease, in vitro. Huntington's disease is a neurodegenerative disorder in a class of human pathologies that includes Alzheimer's and Parkinson's disease. These pathologies are all related by the propensity of their associated protein or polypeptide to form insoluble, β-sheet rich, amyloid fibrils. Despite the wide range of amino acid sequence in the aggregation prone polypeptides associated with these diseases, the resulting amyloids display strikingly similar physical structure, an observation which suggests a physical basis for amyloid fibril formation. Thioflavin T fluorescence reports β-sheet fibril content while dynamic light scattering measures particle size distributions. The combined techniques allow elucidation of complex aggregation kinetics and are used to reveal multiple stages of amyloid fibril formation.

MALDI imaging mass spectrometry profiling of N-glycans in formalin-fixed paraffin embedded clinical tissue blocks and tissue microarrays.

Science.gov (United States)

Powers, Thomas W; Neely, Benjamin A; Shao, Yuan; Tang, Huiyuan; Troyer, Dean A; Mehta, Anand S; Haab, Brian B; Drake, Richard R

2014-01-01

A recently developed matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) method to spatially profile the location and distribution of multiple N-linked glycan species in frozen tissues has been extended and improved for the direct analysis of glycans in clinically derived formalin-fixed paraffin-embedded (FFPE) tissues. Formalin-fixed tissues from normal mouse kidney, human pancreatic and prostate cancers, and a human hepatocellular carcinoma tissue microarray were processed by antigen retrieval followed by on-tissue digestion with peptide N-glycosidase F. The released N-glycans were detected by MALDI-IMS analysis, and the structural composition of a subset of glycans could be verified directly by on-tissue collision-induced fragmentation. Other structural assignments were confirmed by off-tissue permethylation analysis combined with multiple database comparisons. Imaging of mouse kidney tissue sections demonstrates specific tissue distributions of major cellular N-linked glycoforms in the cortex and medulla. Differential tissue distribution of N-linked glycoforms was also observed in the other tissue types. The efficacy of using MALDI-IMS glycan profiling to distinguish tumor from non-tumor tissues in a tumor microarray format is also demonstrated. This MALDI-IMS workflow has the potential to be applied to any FFPE tissue block or tissue microarray to enable higher throughput analysis of the global changes in N-glycosylation associated with cancers.

Learning anatomy through Thiel- vs. formalin-embalmed cadavers: Student perceptions of embalming methods and effect on functional anatomy knowledge.

Science.gov (United States)

Kennel, Larissa; Martin, David M A; Shaw, Hannah; Wilkinson, Tracey

2018-03-01

Thiel-embalmed cadavers, which have been adopted for use in anatomy teaching in relatively few universities, show greater flexibility and color retention compared to formalin-embalmed cadavers, properties which might be considered advantageous for anatomy teaching. This study aimed to investigate student attitudes toward the dissection experience with Thiel- compared to formalin/ethanol-embalmed cadavers. It also aimed to determine if one embalming method is more advantageous in terms of learning functional anatomy through the comparison of student anterior forearm functional anatomy knowledge. Student opinions and functional anatomy knowledge were obtained through use of a questionnaire from students at two medical schools, one using Thiel-, and one using more traditional formalin/ethanol-embalmed cadavers. Both the Thiel group and the formalin group of students were surveyed shortly after completing an anterior forearm dissection session. Significant differences (P-values <0.01) in some attitudes were found toward the dissection experience between cohorts using Thiel- vs. formalin-embalmed cadavers. The Thiel group of students felt more confident about recognizing anatomy in the living individual, found it easier to identify and dissect anatomical structures, and indicated more active exploration of functional anatomy due to the retained flexibility of the cadaver. However, on testing, no significant difference in functional anatomy knowledge was found between the two cohorts. Overall, although Thiel embalming may provide an advantageous learning experience in some investigated areas, more research needs to be carried out, especially to establish whether student perception is based on reality, at least in terms of structure identification. Anat Sci Educ 11: 166-174. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Does ozone enhance the remineralizing potential of nanohydroxyapatite on artificially demineralized enamel? A laser induced fluorescence study

Science.gov (United States)

Srinivasan, Samuelraj; Prabhu, Vijendra; Chandra, Subhash; Koshy, Shalini; Acharya, Shashidhar; Mahato, Krishna K.

2014-02-01

The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (P<0.0001). In a nutshell, ozone enhanced the remineralizing potential of nanohydroxyapatite, and laser induced fluorescence was found to be effective in assessing the surface mineral changes in enamel. Ozone can be considered an effective agent in reversing the initial enamel caries there by preventing the tooth from entering into the repetitive restorative cycle.

Evaluating Quality of Aged Archival Formalin-Fixed Paraffin-Embedded Samples for RNA-Sequencing

Science.gov (United States)

Archival formalin-fixed paraffin-embedded (FFPE) samples offer a vast, untapped source of genomic data for biomarker discovery. However, the quality of FFPE samples is often highly variable, and conventional methods to assess RNA quality for RNA-sequencing (RNA-seq) are not infor...

Detection of biological warfare agents using ultra violet-laser induced fluorescence LIDAR.

Science.gov (United States)

Joshi, Deepti; Kumar, Deepak; Maini, Anil K; Sharma, Ramesh C

2013-08-01

This review has been written to highlight the threat of biological warfare agents, their types and detection. Bacterial biological agent Bacillus anthracis (bacteria causing the disease anthrax) which is most likely to be employed in biological warfare is being discussed in detail. Standoff detection of biological warfare agents in aerosol form using Ultra violet-Laser Induced Fluorescence (UV-LIF) spectroscopy method has been studied. Range-resolved detection and identification of biological aerosols by both nano-second and non-linear femto-second LIDAR is also discussed. Calculated received fluorescence signal for a cloud of typical biological agent Bacillus globigii (Simulants of B. anthracis) at a location of ~5.0 km at different concentrations in presence of solar background radiation has been described. Overview of current research efforts in internationally available working UV-LIF LIDAR systems are also mentioned briefly. Copyright © 2013 Elsevier B.V. All rights reserved.

Stink Bug Feeding Induces Fluorescence in Developing Cotton Bolls

Directory of Open Access Journals (Sweden)

Toews Michael D

2011-08-01

Full Text Available Abstract Background Stink bugs (Hemiptera: Pentatomidae comprise a critically important insect pest complex affecting 12 major crops worldwide including cotton. In the US, stink bug damage to developing cotton bolls causes boll abscission, lint staining, reduced fiber quality, and reduced yields with estimated losses ranging from 10 to 60 million dollars annually. Unfortunately, scouting for stink bug damage in the field is laborious and excessively time consuming. To improve scouting accuracy and efficiency, we investigated fluorescence changes in cotton boll tissues as a result of stink bug feeding. Results Fluorescent imaging under long-wave ultraviolet light showed that stink bug-damaged lint, the inner carpal wall, and the outside of the boll emitted strong blue-green fluorescence in a circular region near the puncture wound, whereas undamaged tissue emissions occurred at different wavelengths; the much weaker emission of undamaged tissue was dominated by chlorophyll fluorescence. We further characterized the optimum emission and excitation spectra to distinguish between stink bug damaged bolls from undamaged bolls. Conclusions The observed characteristic fluorescence peaks associated with stink bug damage give rise to a fluorescence-based method to rapidly distinguish between undamaged and stink bug damaged cotton bolls. Based on the fluorescent fingerprint, we envision a fluorescence reflectance imaging or a fluorescence ratiometric device to assist pest management professionals with rapidly determining the extent of stink bug damage in a cotton field.

A Class I UV-Blocking (senofilcon A) Soft Contact Lens Prevents UVA-induced Yellow Fluorescence and NADH loss in the Rabbit Lens Nucleus in vivo

Science.gov (United States)

Giblin, Frank J.; Lin, Li-Ren; Simpanya, Mukoma F.; Leverenz, Victor R.; Fick, Catherine E.

2012-01-01

It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm2 on the cornea) for 1 hour using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 hour. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear �

Fluorescent tagged episomals for stoichiometric induced pluripotent stem cell reprogramming.

Science.gov (United States)

Schmitt, Christopher E; Morales, Blanca M; Schmitz, Ellen M H; Hawkins, John S; Lizama, Carlos O; Zape, Joan P; Hsiao, Edward C; Zovein, Ann C

2017-06-05

Non-integrating episomal vectors have become an important tool for induced pluripotent stem cell reprogramming. The episomal vectors carrying the "Yamanaka reprogramming factors" (Oct4, Klf, Sox2, and L-Myc + Lin28) are critical tools for non-integrating reprogramming of cells to a pluripotent state. However, the reprogramming process remains highly stochastic, and is hampered by an inability to easily identify clones that carry the episomal vectors. We modified the original set of vectors to express spectrally separable fluorescent proteins to allow for enrichment of transfected cells. The vectors were then tested against the standard original vectors for reprogramming efficiency and for the ability to enrich for stoichiometric ratios of factors. The reengineered vectors allow for cell sorting based on reprogramming factor expression. We show that these vectors can assist in tracking episomal expression in individual cells and can select the reprogramming factor dosage. Together, these modified vectors are a useful tool for understanding the reprogramming process and improving induced pluripotent stem cell isolation efficiency.

Toluene laser-induced fluorescence imaging of compressible flows in an expansion tube

Science.gov (United States)

Miller, V. A.; Gamba, M.; Mungal, M. G.; Hanson, R. K.; Mohri, K.; Schulz, C.

2011-11-01

Laser-induced fluorescence (LIF) imaging using toluene as a tracer molecule has been developed for high-speed, low-to-moderate enthalpy conditions in the Stanford 6-inch Expansion Tube. The approach is demonstrated on three canonical compressible flow configurations: (i) supersonic flow over a 20° wedge, (ii) around a cylinder, and (iii) a supersonic boundary layer. Under constant-pressure conditions, toluene LIF offers unique sensitivity to temperature and can therefore be used as an accurate thermometry diagnostic for supersonic flows; on the other hand, for variable-pressure flow fields (e.g., flow around a blunt body), toluene LIF imaging is demonstrated to be an effective flow visualization tool. The three configurations selected demonstrate the diagnostic in these two capacities. For all configurations considered in the study, toluene (0.6% by volume) is seeded into a nitrogen freestream at a Mach number ~ 2.2, T ~ 500K, and p ~ 1.5 bar. A frequency-quadrupled pulsed Nd:YAG laser is used to excite the tracer, and the resulting fluorescence is captured by an ICCD camera. Synthetic fluorescence signals from CFD solutions of each case have been computed and compare favorably to measured signals. Sponsored by DoE PSAAP at Stanford University.

Laser-induced fluorescence of se, as, and sb in an electrothermal atomizer.

Science.gov (United States)

Swart, D J; Ezer, M; Pacquette, H L; Simeonsson, J B

1998-04-01

Trace detection of Se, As, and Sb atoms has been performed by electrothermal atomization laser-induced fluorescence (ETA-LIF) approaches. Production of far-UV radiation necessary for excitation of As atoms at 193.696 nm and Se atoms at 196.026 nm was accomplished by stimulated Raman shifting (SRS) of the output of a frequency-doubled dye laser operating near 230 nm. Both wavelengths were obtained as second-order anti-Stokes shifts of the dye laser radiation and provided up to 10 μJ/pulse, which was shown through power dependence studies to be sufficient for saturation in the ETA. An excited-state direct line fluorescence approach using excitation at 206.279 nm was also investigated for the LIF detection of Se. High-sensitivity LIF of Sb atoms was accomplished using 206.833-nm excitation and detection at 259.805 nm. The accuracy of the ETA-LIF approaches was demonstrated by determining the As and Se content of aqueous reference samples. The limits of detection (absolute mass) were 200 fg by ground-state LIF and 150 fg by excited-state direct line fluorescence for Se, 200 fg for As, and 10 fg for Sb; these LODs compare favorably with results reported previously in the literature for ETA-LIF, GFAAS, and ICP-MS methods.

Ultrasensitive fluorescence immunoassay for detection of ochratoxin A using catalase-mediated fluorescence quenching of CdTe QDs

Science.gov (United States)

Huang, Xiaolin; Zhan, Shengnan; Xu, Hengyi; Meng, Xianwei; Xiong, Yonghua; Chen, Xiaoyuan

2016-04-01

Herein, for the first time we report an improved competitive fluorescent enzyme linked immunosorbent assay (ELISA) for the ultrasensitive detection of ochratoxin A (OTA) by using hydrogen peroxide (H2O2)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (QDs). In this immunoassay, catalase (CAT) was labeled with OTA as a competitive antigen to connect the fluorescence signals of the QDs with the concentration of the target. Through the combinatorial use of H2O2-induced fluorescence quenching of CdTe QDs as a fluorescence signal output and the ultrahigh catalytic activity of CAT to H2O2, our proposed method could be used to perform a dynamic linear detection of OTA ranging from 0.05 pg mL-1 to 10 pg mL-1. The half maximal inhibitory concentration was 0.53 pg mL-1 and the limit of detection was 0.05 pg mL-1. These values were approximately 283- and 300-folds lower than those of horseradish peroxidase (HRP)-based conventional ELISA, respectively. The reported method is accurate, highly reproducible, and specific against other mycotoxins in agricultural products as well. In summary, the developed fluorescence immunoassay based on H2O2-induced fluorescence quenching of CdTe QDs can be used for the rapid and highly sensitive detection of mycotoxins or haptens in food safety monitoring.Herein, for the first time we report an improved competitive fluorescent enzyme linked immunosorbent assay (ELISA) for the ultrasensitive detection of ochratoxin A (OTA) by using hydrogen peroxide (H2O2)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (QDs). In this immunoassay, catalase (CAT) was labeled with OTA as a competitive antigen to connect the fluorescence signals of the QDs with the concentration of the target. Through the combinatorial use of H2O2-induced fluorescence quenching of CdTe QDs as a fluorescence signal output and the ultrahigh catalytic activity of CAT to H2O2, our proposed method could be used to

Characterization by fluorescence of dissolved organic matter in rural drinking water storage tanks in Morocco.

Science.gov (United States)

Aziz, Faissal; Ouazzani, Naaila; Mandi, Laila; Assaad, Aziz; Pontvianne, Steve; Poirot, Hélène; Pons, Marie-Noëlle

2018-04-01

Water storage tanks, fed directly from the river through opened channels, are particular systems used for water supply in rural areas in Morocco. The stored water is used as drinking water by the surrounding population without any treatment. UV-visible spectroscopy and fluorescence spectroscopy (excitation-emission matrices and synchronous fluorescence) have been tested as rapid methods to assess the quality of the water stored in the reservoirs as well as along the river feeding them. Synchronous fluorescence spectra (SFS50), collected with a difference of 50 nm between excitation and emission wavelengths, revealed a high tryptophan-like fluorescence, indicative of a pollution induced by untreated domestic and/or farm wastewater. The best correlations were obtained between the total SFS50 fluorescence and dissolved organic carbon (DOC) and biological oxygen demand, showing that the contribution of humic-like fluorescent substances cannot be neglected to rapidly assess reservoir water quality in terms of DOC by fluorescence spectroscopy.

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde–free laboratory is possible

Directory of Open Access Journals (Sweden)

Zanini Cristina

2012-09-01

Full Text Available Abstract Background Formaldehyde (HCHO is a gas (available as a 37% concentrated solution, stabilized with methanol. The 10% dilution (approximately 4% formaldehyde has been used as a fixative since the end of the 19th century. Alternative fixatives are also commercially available or may be prepared in-house in laboratories. Statements by the IARC, along with other USA agencies (CalEPA, RoC/NTP on the carcinogenicity of formaldehyde for humans renders its substitution in Pathology Departments necessary since the annual use of formalin may exceed 3,500 liters for a medium-large laboratory. To achieve a “formalin-free laboratory” we tested straightforward-to-make fixatives along with registered reagents offered as formalin substitutes. Methods More than two hundreds specimens were fixed in parallel with in-laboratory made fixatives PAGA (Polyethylenglycol, ethyl Alcohol, Glycerol, Acetic acid, two zinc-based fixatives (ZBF, Z7, and commercially-available alternatives (RCL2 and CellBlock. Tissue micro arrays were used for morphological and immunohistochemical comparison. Extraction of RNA was carried out to evaluate preservation of nucleic acids. Results Differences compared to formalin fixation were evident in alcohol-based fixatives, mainly restricted to higher stain affinity and considerable tissue shrinkage. Conversely, nuclear detail was superior with these alcohol-based formulas compared to formalin or glyoxale-based recipes. RNA extraction was superior for Z7, PAGA and RCL2 with regard to concentration but relatively comparable regarding quality. Conclusions Abolition of the human carcinogen formaldehyde from pathology laboratories is possible even in contexts whereby commercial alternatives to formalin are unavailable or are too expensive for routine use, and aspiration devices are lacking or not adequately serviced. The use of known formulations, possibly with simple and not-noxious (“alimentary grade” constituents, comparable with

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde–free laboratory is possible

Science.gov (United States)

2012-01-01

Background Formaldehyde (HCHO) is a gas (available as a 37% concentrated solution, stabilized with methanol). The 10% dilution (approximately 4% formaldehyde) has been used as a fixative since the end of the 19th century. Alternative fixatives are also commercially available or may be prepared in-house in laboratories. Statements by the IARC, along with other USA agencies (CalEPA, RoC/NTP) on the carcinogenicity of formaldehyde for humans renders its substitution in Pathology Departments necessary since the annual use of formalin may exceed 3,500 liters for a medium-large laboratory. To achieve a “formalin-free laboratory” we tested straightforward-to-make fixatives along with registered reagents offered as formalin substitutes. Methods More than two hundreds specimens were fixed in parallel with in-laboratory made fixatives PAGA (Polyethylenglycol, ethyl Alcohol, Glycerol, Acetic acid), two zinc-based fixatives (ZBF, Z7), and commercially-available alternatives (RCL2 and CellBlock). Tissue micro arrays were used for morphological and immunohistochemical comparison. Extraction of RNA was carried out to evaluate preservation of nucleic acids. Results Differences compared to formalin fixation were evident in alcohol-based fixatives, mainly restricted to higher stain affinity and considerable tissue shrinkage. Conversely, nuclear detail was superior with these alcohol-based formulas compared to formalin or glyoxale-based recipes. RNA extraction was superior for Z7, PAGA and RCL2 with regard to concentration but relatively comparable regarding quality. Conclusions Abolition of the human carcinogen formaldehyde from pathology laboratories is possible even in contexts whereby commercial alternatives to formalin are unavailable or are too expensive for routine use, and aspiration devices are lacking or not adequately serviced. The use of known formulations, possibly with simple and not-noxious (“alimentary grade”) constituents, comparable with registered

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde-free laboratory is possible.

Science.gov (United States)

Zanini, Cristina; Gerbaudo, Elisa; Ercole, Elisabetta; Vendramin, Anna; Forni, Marco

2012-09-04

Formaldehyde (HCHO) is a gas (available as a 37% concentrated solution, stabilized with methanol). The 10% dilution (approximately 4% formaldehyde) has been used as a fixative since the end of the 19th century. Alternative fixatives are also commercially available or may be prepared in-house in laboratories. Statements by the IARC, along with other USA agencies (CalEPA, RoC/NTP) on the carcinogenicity of formaldehyde for humans renders its substitution in Pathology Departments necessary since the annual use of formalin may exceed 3,500 liters for a medium-large laboratory. To achieve a "formalin-free laboratory" we tested straightforward-to-make fixatives along with registered reagents offered as formalin substitutes. More than two hundreds specimens were fixed in parallel with in-laboratory made fixatives PAGA (Polyethylenglycol, ethyl Alcohol, Glycerol, Acetic acid), two zinc-based fixatives (ZBF, Z7), and commercially-available alternatives (RCL2 and CellBlock). Tissue micro arrays were used for morphological and immunohistochemical comparison. Extraction of RNA was carried out to evaluate preservation of nucleic acids. Differences compared to formalin fixation were evident in alcohol-based fixatives, mainly restricted to higher stain affinity and considerable tissue shrinkage. Conversely, nuclear detail was superior with these alcohol-based formulas compared to formalin or glyoxale-based recipes. RNA extraction was superior for Z7, PAGA and RCL2 with regard to concentration but relatively comparable regarding quality. Abolition of the human carcinogen formaldehyde from pathology laboratories is possible even in contexts whereby commercial alternatives to formalin are unavailable or are too expensive for routine use, and aspiration devices are lacking or not adequately serviced. The use of known formulations, possibly with simple and not-noxious ("alimentary grade") constituents, comparable with registered proprietary products, may expand the search for the

THE REGIONAL DIFFERENCES OF GPP ESTIMATION BY SOLAR INDUCED FLUORESCENCE

Directory of Open Access Journals (Sweden)

X. Wang

2018-04-01

Full Text Available Estimating gross primary productivity (GPP at large spatial scales is important for studying the global carbon cycle and global climate change. In this study, the relationship between solar-induced chlorophyll fluorescence (SIF and GPP is analysed in different levels of annual average temperature and annual total precipitation respectively using simple linear regression analysis. The results showed high correlation between SIF and GPP, when the area satisfied annual average temperature in the range of −5 °C to 15 °C and the annual total precipitation is higher than 200 mm. These results can provide a basis for future estimation of GPP research.

Influence of Formalin Fixation Prior to in vitro Ultrasound Examination of Porcine Arteries

DEFF Research Database (Denmark)

Wilhjelm, Jens E.; Vogt, Katja; Jespersen, Søren Kragh

1996-01-01

This paper reports on an investigation of the influence on the echosignal from porcine artery walls due to two different formalin fixationprocedures. The lumen diameter, the wall thickness and the mean echogenicitywere calculated. In general, the fixation resulted in a more rigid wall. Whileconve...

Activity-Guided Isolation of Bioactive Constituents with Antinociceptive Activity from Muntingia calabura L. Leaves Using the Formalin Test

Directory of Open Access Journals (Sweden)

Mohd. Izwan Mohamad Yusof

2013-01-01

Full Text Available The present study was conducted to determine the antinociceptive potential of methanol extract of Muntingia calabura L. (MEMC and to isolate and identify the bioactive compound(s responsible for the observed antinociceptive activity. The MEMC and its partitions (petroleum ether (PEP, ethyl acetate (EAP, and aqueous (AQP partitions, in the dose range of 100, 500, and 1000 mg/kg, were tested using the formalin-induced nociceptive test. The PEP, which exerted the most effective activity in the respective early and late phase, was further subjected to the fractionation procedures and yielded seven fractions (labelled A to G. These fractions were tested, at the dose of 300 mg/kg, together with distilled water or 10% DMSO (negative controls; morphine and aspirin (positive controls for potential antinociceptive activity. Of all fractions, Fraction D showed the most significant antinociceptive activity, which is considered as equieffective to morphine or aspirin in the early or late phase, respectively. Further isolation and identification processes on fraction D led to the identification of three known and one new compounds, namely, 5-hydroxy-3,7,8-trimethoxyflavone (1, 3,7-dimethoxy-5-hydroyflavone (2, 2′,4′-dihydroxy-3′-methoxychalcone (3, and calaburone (4. At the dose of 50 mg/kg, compound 3 exhibited the highest percentage of antinociceptive activity in both phases of the formalin test. In conclusion, the antinociceptive activity of MEMC involved, partly, the synergistic activation of the flavonoid types of compounds.

Detection of potassium deficiency on palm oil tree (Elaeis guineensis (jacq)) by laser induced fluorescence

International Nuclear Information System (INIS)

Diomande, K.; Konate, A.; Krou Adjo, V.; Soro, A.; Ebby, N.; Ballo, K.

1998-02-01

The potassium is the main nutrient element which plays a significant role on oil palm tree (Elaeis guineensis (jacq)) production and its resistance to the dry season. One can observe 30% decrease of the production in case of potassium deficiency. The potassium nutrition control of an oil palm tree field is a very important activity and leads to the fertilization policy. The Laser Induced Fluorescence (L.I.F.) is a fast and simple method compared to the classical one, ''Diagnostic Foliaire'', usually used in agronomy. We used the L.I.F. method to detect the oil palm tree stress caused by potassium deficiency, analysing the fluorescence spectrum of the chlorophyll a. We proved that the intensity ratio of the fluorescence spectrum R=F690/F73S is superior to 0.5 when the tree is under stress and its value is around 0.4 in case of intact tree. (author)

Generation and characterization of a stable cell population releasing fluorescent HIV-1-based Virus Like Particles in an inducible way

Directory of Open Access Journals (Sweden)

Bosch Valerie

2006-12-01

Full Text Available Abstract Background The availability of cell lines releasing fluorescent viral particles can significantly support a variety of investigations, including the study of virus-cell interaction and the screening of antiviral compounds. Regarding HIV-1, the recovery of such biologic reagents represents a very hard challenge due to the intrinsic cytotoxicity of many HIV-1 products. We sought to overcome such a limitation by using a cell line releasing HIV-1 particles in an inducible way, and by exploiting the ability of a HIV-1 Nef mutant to be incorporated in virions at quite high levels. Results Here, we report the isolation and characterization of a HIV-1 packaging cell line, termed 18-4s, able to release valuable amounts of fluorescent HIV-1 based Virus-Like Particles (VLPs in an inducible way. 18-4s cells were recovered by constitutively expressing the HIV-1 NefG3C mutant fused with the enhanced-green fluorescent protein (NefG3C-GFP in a previously isolated inducible HIV-1 packaging cell line. The G3C mutation creates a palmitoylation site which results in NefG3C-GFP incorporation into virions greatly exceeding that of the wild type counterpart. Upon induction of 18-4s cells with ponasterone A and sodium butyrate, up to 4 μg/ml of VLPs, which had incorporated about 150 molecules of NefG3C-GFP per viral particle, were released into the culture supernatant. Due to their intrinsic strong fluorescence, the 18-4s VLPs were easily detectable by a novel cytofluorometric-based assay developed here. The treatment of target cells with fluorescent 18-4 VLPs pseudotyped with different glycoprotein receptors resulted in these becoming fluorescent as early as two hours post-challenge. Conclusion We created a stable cell line releasing fluorescent HIV-1 based VLPs upon induction useful for several applications including the study of virus-cell interactions and the screening of antiviral compounds.

The used of formalin, borax and initial bacterial contamination on otak-otak

International Nuclear Information System (INIS)

Harsojo; Kadir I

2013-01-01

A research has been conducted to identify the used of formalin and borax content and also study the initial bacterial contamination on otak-otak. The wrapped and unwrapped samples were irradiated with a dose of 3 kGy Further, the samples were stored at room temperature (± 30°C) and low temperature (± 4°C) up to 4 weeks. The irradiation was done at a Multipurpose Panoramic Batch Irradiator (IRPASENA) with a dose rate of 1.149 kGy/h. Those samples were stored 4 weeks at 2 different temperatures and the total bacteria were observe every week. The measured parameter were formalin and borax content in otak-otak, the amount of total aerob bacteria, total coliforms, Escherichia coli, Staphylococcus spp., identification of Salmonella. The results showed all samples used formalin but borax was not detected. Initial contamination of total aerob bacteria for unwrapped and wrapped samples were 4.3 x 10"7 and 2.0 x 10"7 cfu/g, respectively. Irradiation dose up to 3 kGy showed no bacterial growth on unwrapped and wrapped samples. Combination treatment of irradiation and storage at low temperature could eliminate all aerobic bacteria at the first week. Initial contamination of coliform bacteria on unwrapped and wrapped samples were 1.9 x 10"5 and 5.7 x 10"5 cfu/g, respectively. Initial contamination of E. coli on unwrapped and wrapped samples were 1.2 x 10"5 cfu/g. The total amount of Staphylococcus spp. on unwrapped and wrapped samples were 3.3 x 10"5 and 4.8 x 10"6 cfu/g, respectively. Irradiation at a dose of 3 kGy could eliminate coliform bacteria, E. coli and Staphylococcus spp in all samples observed. No Salmonella was detected in all samples observed. (author)

Analytical validation of a melanoma diagnostic gene signature using formalin-fixed paraffin-embedded melanocytic lesions.

Science.gov (United States)

Warf, M Bryan; Flake, Darl D; Adams, Doug; Gutin, Alexander; Kolquist, Kathryn A; Wenstrup, Richard J; Roa, Benjamin B

2015-01-01

These studies were to validate the analytical performance of a gene expression signature that differentiates melanoma and nevi, using RNA expression from 14 signature genes and nine normalization genes that generates a melanoma diagnostic score (MDS). Formalin-fixed paraffin-embedded melanocytic lesions were evaluated in these studies. The overall SD of the assay was determined to be 0.69 MDS units. Individual amplicons within the signature had an average amplification efficiency of 92% and a SD less than 0.5 CT. The MDS was reproducible across a 2000-fold dilution range of input RNA. Melanin, an inhibitor of PCR, does not interfere with the signature. These studies indicate this signature is robust and reproducible and is analytically validated on formalin-fixed paraffin-embedded melanocytic lesions.

Ultrasensitive near-infrared fluorescence-enhanced probe for in vivo nitroreductase imaging.

Science.gov (United States)

Li, Yuhao; Sun, Yun; Li, Jiachang; Su, Qianqian; Yuan, Wei; Dai, Yu; Han, Chunmiao; Wang, Qiuhong; Feng, Wei; Li, Fuyou

2015-05-20

Nitroreductase (NTR) can be overexpressed in hypoxic tumors, thus the selective and efficient detection of NTR is of great importance. To date, although a few optical methods have been reported for the detection of NTR in solution, an effective optical probe for NTR monitoring in vivo is still lacking. Therefore, it is necessary to develop a near-infrared (NIR) fluorescent detection probe for NTR. In this study, five NIR cyanine dyes with fluorescence reporting structure decorated with different nitro aromatic groups, Cy7-1-5, have been designed and explored for possible rapid detection of NTR. Our experimental results presented that only a para-nitro benzoate group modified cyanine probe (Cy7-1) could serve as a rapid NIR fluorescence-enhanced probe for monitoring and bioimaging of NTR. The structure-function relationship has been revealed by theoretical study. The linker connecting the detecting and fluorescence reporting groups and the nitro group position is a key factor for the formation of hydrogen bonds and spatial structure match, inducing the NTR catalytic ability enhancement. The in vitro response and mechanism of the enzyme-catalyzed reduction of Cy7-1 have been investigated through kinetic optical studies and other methods. The results have indicated that an electro-withdrawing group induced electron-transfer process becomes blocked when Cy7-1 is catalytically reduced to Cy7-NH2 by NTR, which is manifested in enhanced fluorescence intensity during the detection process. Confocal fluorescence imaging of hypoxic A549 cells has confirmed the NTR detection ability of Cy7-1 at the cellular level. Importantly, Cy7-1 can detect tumor hypoxia in a murine hypoxic tumor model, showing a rapid and significant enhancement of its NIR fluorescence characteristics suitable for fluorescence bioimaging. This method may potentially be used for tumor hypoxia diagnosis.

Imaging of activated caspase-3 in living cell by fluorescence resonance energy transfer during photosensitization-induced apoptosis

Science.gov (United States)

Wu, Yunxia; Xing, Da; Chen, Qun; Tang, Yonghong

2005-01-01

Photodynamic therapy (PDT) is a novel and promising cancer treatment that employs a combination of a photosensitizing chemical and visible light, induces apoptosis in cell, and activation of caspase-3 is considered to be the final step in many apoptosis pathways. The changes of caspase-3 activation in cell during TNFα- and photodynamic therapy-induced apoptosis was measured by fluorescence resonance energy transfer (FRET) analysis. FRET probe consisting of fusions of an enhanced cyan fluorescent protein (ECFP), Venus and a linker peptide containing the caspase-3 cleavage sequence DEVD was utilized. Therefore, activated caspase-3 cleaved the linker peptide of FRET probe and disrupted the FRET signal. Human lung adenocarcinoma cell line (ASTC-a-1) were stably transfected with the plasmid (ECFP-DEVD-Venus) and then were treated by TNF-α and PDT, respectively. Experimental results indicated that caspase-3 activation resulted in cleavage of linker peptide and subsequent disruption of the FRET signal during TNFα- and photodynamic therapy-induced apoptosis, and that the activation of caspase-3 induced by photodynamic therapy was faster than that induce by TNF-α. The study supports that using FRET technique and different recombinant substrates as FRET probes could be used to detect the process of PDT-induced apoptosis and provide a new means to investigate apoptotic mechanism of PDT.

Proximal Sensing of Plant-Pathogen Interactions in Spring Barley with Three Fluorescence Techniques

Directory of Open Access Journals (Sweden)

Georg Leufen

2014-06-01

Full Text Available In the last years fluorescence spectroscopy has come to be viewed as an essential approach in key research fields of applied plant sciences. However, the quantity and particularly the quality of information produced by different equipment might vary considerably. In this study we investigate the potential of three optical devices for the proximal sensing of plant-pathogen interactions in four genotypes of spring barley. For this purpose, the fluorescence lifetime, the image-resolved multispectral fluorescence and selected indices of a portable multiparametric fluorescence device were recorded at 3, 6, and 9 days after inoculation (dai from healthy leaves as well as from leaves inoculated with powdery mildew (Blumeria graminis or leaf rust (Puccinia hordei. Genotype-specific responses to pathogen infections were revealed already at 3 dai by higher fluorescence mean lifetimes in the spectral range from 410 to 560 nm in the less susceptible varieties. Noticeable pathogen-induced modifications were also revealed by the ‘Blue-to-Far-Red Fluorescence Ratio’ and the ‘Simple Fluorescence Ratio’. Particularly in the susceptible varieties the differences became more evident in the time-course of the experiment i.e., following the pathogen development. The relevance of the blue and green fluorescence to exploit the plant-pathogen interaction was demonstrated by the multispectral fluorescence imaging system. As shown, mildewed leaves were characterized by exceptionally high blue fluorescence, contrasting the values observed in rust inoculated leaves. Further, we confirm that the intensity of green fluorescence depends on the pathogen infection and the stage of disease development; this information might allow a differentiation of both diseases. Moreover, our results demonstrate that the detection area might influence the quality of the information, although it had a minor impact only in the current study. Finally, we highlight the relevance of

Investigating and comparing effects of atropine and physostigmine in peripheral pain examination due to formalin injection on rats

Directory of Open Access Journals (Sweden)

Mohammad Pourahmadi

2016-07-01

Full Text Available There areseveral neurotransmittersat feel the pain and processing nervoussystem, and until now cholinergic system has not been well studied in this field. The purpose of this research is investigating effects of atropine and physostigmine on the response of formalin pain test. We divided 50 male wistar head rats into 5 groups , first group ( saline normal injection 5 µ , second group ( 1% formalin injection into 50 µ , third group ( physostigmine injection 0/1 mg / kg , fourth group (atropine injection 2 mg / kg , fifth group ( atropine injection 2 mg / kg and physostigmine 0/1 mg/kg , after formalin injection , the animals were placed inside mirror pain machine and it was recorded pain response at the time ranges 0-5 and 15-45 . Results investigated with spss software and ANOVA and Duncan’s test. Formalin injection causes pain response in both time ranges. Atropine injection alone had no effect on pain response. Physostigmine effect alone, with a significant reduction (p< 0/05 in the number of foot motions in both stage and duration causesof licking and biting in the 15-45 minutes stage . Atropine and physostigmine injections in fifth group cause significant reduction in the number of foot motions and duration of licking and biting in the time range of 15-45 minutes.Perhaps there is a close relationship between cholinergic system and peripheral pain that can be taken through the action of muscarinic receptors.

Profiling cancer gene mutations in clinical formalin-fixed, paraffin-embedded colorectal tumor specimens using targeted next-generation sequencing.

Science.gov (United States)

Zhang, Liangxuan; Chen, Liangjing; Sah, Sachin; Latham, Gary J; Patel, Rajesh; Song, Qinghua; Koeppen, Hartmut; Tam, Rachel; Schleifman, Erica; Mashhedi, Haider; Chalasani, Sreedevi; Fu, Ling; Sumiyoshi, Teiko; Raja, Rajiv; Forrest, William; Hampton, Garret M; Lackner, Mark R; Hegde, Priti; Jia, Shidong

2014-04-01

The success of precision oncology relies on accurate and sensitive molecular profiling. The Ion AmpliSeq Cancer Panel, a targeted enrichment method for next-generation sequencing (NGS) using the Ion Torrent platform, provides a fast, easy, and cost-effective sequencing workflow for detecting genomic "hotspot" regions that are frequently mutated in human cancer genes. Most recently, the U.K. has launched the AmpliSeq sequencing test in its National Health Service. This study aimed to evaluate the clinical application of the AmpliSeq methodology. We used 10 ng of genomic DNA from formalin-fixed, paraffin-embedded human colorectal cancer (CRC) tumor specimens to sequence 46 cancer genes using the AmpliSeq platform. In a validation study, we developed an orthogonal NGS-based resequencing approach (SimpliSeq) to assess the AmpliSeq variant calls. Validated mutational analyses revealed that AmpliSeq was effective in profiling gene mutations, and that the method correctly pinpointed "true-positive" gene mutations with variant frequency >5% and demonstrated high-level molecular heterogeneity in CRC. However, AmpliSeq enrichment and NGS also produced several recurrent "false-positive" calls in clinically druggable oncogenes such as PIK3CA. AmpliSeq provided highly sensitive and quantitative mutation detection for most of the genes on its cancer panel using limited DNA quantities from formalin-fixed, paraffin-embedded samples. For those genes with recurrent "false-positive" variant calls, caution should be used in data interpretation, and orthogonal verification of mutations is recommended for clinical decision making.

Femtosecond two-photon laser-induced fluorescence of krypton for high-speed flow imaging.

Science.gov (United States)

Wang, Yejun; Capps, Cade; Kulatilaka, Waruna D

2017-02-15

Ultrashort-pulse (femtosecond-duration) two-photon laser-induced fluorescence (fs-TPLIF) of an inert gas tracer krypton (Kr) is investigated. A detailed spectroscopic study of fluorescence channels followed by the 5p'←←4p excitation of Kr at 204.1 nm is reported. The experimental line positions in the 750-840 nm emission region agree well with the NIST Atomic Spectra Database. The present work provides an accurate listing of relative line strengths in this spectral region. In the range of laser pulse energies investigated, a quadratic dependence was observed between the Kr-TPLIF signal and the laser pulse energy. The single-laser-shot 2D TPLIF images recorded in an unsteady jet demonstrate the potential of using fs excitation at 204.1 nm for mixing and flow diagnostic studies using Kr as an inert gas tracer.

Sun-induced chlorophyll fluorescence, photosynthesis, and light use efficiency of a soybean field from seasonally continuous measurements

Science.gov (United States)

Recent development of sun-induced chlorophyll fluorescence (SIF) technology is stimulating studies to remotely approximate canopy photosynthesis (measured as gross primary production, GPP). While multiple applications have advanced the empirical relationship between GPP and SIF, mechanistic understa...

Analgesia induced by morphine microinjected into the nucleus raphe magnus: effects on tonic pain.

Science.gov (United States)

Dualé, Christian; Sierralta, Fernando; Dallel, Radhouane

2007-07-01

One of the possible sites of action of the analgesic effect of morphine is the Nucleus Raphe Magnus, as morphine injected into this structure induces analgesia in transient pain models. In order to test if morphine in the Nucleus Raphe Magnus is also analgesic in a tonic pain model, 5 microg of morphine or saline (control) were microinjected into the Nucleus Raphe Magnus of the rat. Analgesic effects were assessed following nociceptive stimulation using transient heating of the tail (phasic pain) and subcutaneous orofacial injection of 1.5 % formalin (tonic pain). While morphine was strongly analgesic for the tail-flick response (p <0.0001 compared to control), analgesia on the response to formalin was also observed for both early (p = 0.007) and late responses (p = 0.02). However, the response to formalin was not completely blunted. These results suggest that the Nucleus Raphe Magnus is not the exclusive site of action of morphine-induced analgesia in clinical conditions.

Smart Drug Delivery System-Inspired Enzyme-Linked Immunosorbent Assay Based on Fluorescence Resonance Energy Transfer and Allochroic Effect Induced Dual-Modal Colorimetric and Fluorescent Detection.

Science.gov (United States)

Miao, Luyang; Zhu, Chengzhou; Jiao, Lei; Li, He; Du, Dan; Lin, Yuehe; Wei, Qin

2018-02-06

Numerous analytical techniques have been undertaken for the detection of protein biomarkers because of their extensive and significant applications in clinical diagnosis, whereas there are few strategies to develop dual-readout immunosensors to achieve more accurate results. To the best of our knowledge, inspired by smart drug delivery system (DDS), a novel pH-responsive modified enzyme-linked immunosorbent assay (ELISA) was innovatively developed for the first time, realizing dual-modal colorimetric and fluorescent detection of cardiac troponin I (cTnI). Curcumin (CUR) was elaborately selected as a reporter molecule, which played the same role of drugs in DDS based on the following considerations: (1) CUR can be used as a kind of pH indicator by the inherited allochroic effect induced by basic pH value; (2) the fluorescence of CUR can be quenched by certain nanocarriers as the acceptor because of the occurrence of fluorescence resonance energy transfer (FRET), while recovered by the stimuli of basic pH value, which can produce "signal-on" fluorescence detection. Three-dimensional MoS 2 nanoflowers (3D-MoS 2 NFs) were employed in immobilizing CUR to constitute a nanoprobe for the determination of cTnI by virtue of good biocompatibility, high absorption capacity, and fluorescence quench efficiency toward CUR. The proposed DDS-inspired ELISA offered dual-modal colorimetric and fluorescent detection of cTnI, thereby meeting the reliable and precise analysis requirements. We believe that the developed dual-readout ELISA will create a new avenue and bring innovative inspirations for biological detections.

Comparison of Tissue Preservation using Formalin and Ethanol as Preservative Formula

OpenAIRE

See Woan Shian; Arifin Soenggono; Sawkar Vijay Pramod

2016-01-01

Background: Tissue preservation can be performed through embalming, by providing the chemical embalming fluid to the human remains. Formalin’s preservative formula is the foundation for modern methods of embalming. Unfortunately, this preservative formula has several disadvantages. While Ethanol’s preservative formula is a considerable agent to replace formalin’s preservative formula. The aim of this study was to compare the tissue preservation using formalin and ethanol as preservative formu...

Phase-contrast X-ray CT imaging of the kidney. Differences between ethanol fixation and formalin fixation

International Nuclear Information System (INIS)

Shirai, Ryota; Kunii, Takuya; Maruyama, Hiroko; Takeda, Tohoru; Yoneyama, Akio; Lwin, Thet Thet

2012-01-01

A phase-contrast X-ray imaging technique using an X-ray interferometer that provides approximately 1000 times higher sensitivity than the conventional X-ray imaging method for low-atomic number elements based on the difference in the mass attenuation coefficient has recently been developed. In the present study, we compared rat kidneys fixed in 100% ethanol and in 10% formalin to evaluate the effects of ethanol in enhancing image contrast in phase-contrast imaging because ethanol causes significant dehydration of tissues and enhances density differences between tissue components. The experiments were conducted at the Photon Factory in Tsukuba, and the X-ray energy was set at 35 keV. Fine anatomical structures in the kidney such as the glomeruli, tubules, and vessels were observed. Particularly clear renal images were obtained with ethanol fixation. The pixel value ratio between the cortex and medulla was about 43% in ethanol-fixed kidneys and 21% in formalin-fixed kidneys. In other words, the contrast in ethanol-fixed kidneys was about two times higher than that in formalin-fixed kidneys. Histological examination showed significantly condensed features in the cortex. The results of this study suggest that the ethanol fixation technique may be useful for enhancing the image contrast of renal structures in the phase-contrast X-ray imaging technique. (author)

A vacuum-UV laser-induced fluorescence experiment for measurement of rotationally and vibrationally excited H2

NARCIS (Netherlands)

Vankan, P.J.W.; Heil, S.B.S.; Mazouffre, S.; Engeln, R.A.H.; Schram, D.C.; Döbele, H.F.

2004-01-01

An experimental setup is built to detect spatially resolved rovibrationally excited hydrogen molecules via laser-induced fluorescence. To excite the hydrogen molecules, laser radiation is produced in the vacuum UV part of the spectrum. The laser radiation is tunable between 120 nm and 230 nm and has

Evaluation of the antinociceptive activities of enaminone compounds on the formalin and hot plate tests in mice

Science.gov (United States)

Masocha, Willias; Kombian, Samuel B.; Edafiogho, Ivan O.

2016-02-01

Recently, we found that methyl 4-(4‧-bromophenyl)aminocyclohex-3-en-6-methyl-2-oxo-1-oate (E139), an anticonvulsant enaminone, has antinociceptive activity in the hot plate test. In this study we evaluated the antinociceptive activity of five anilino enaminones E139, ethyl 4-(4‧-chlorophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (E121), ethyl 4-(4‧-bromophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (E122), methyl 4-(4‧-chlorophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (E138) and ethyl 4-(4‧-fluorophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (BRG 19) using the formalin and hot plate tests. E139 has been reported to exert its effects via enhancement of extracellular GABA levels, thus tiagabine, a GABA transporter inhibitor, was evaluated as a control together with indomethacin. Tiagabine had antinociceptive activity in both phase 1 (neurogenic pain) and phase 2 (inflammatory pain) of the formalin test, whereas indomethacin had activity only in phase 2. E139 and E138 had antinociceptive activity in both phases of the formalin test, whereas E121 had activity only in phase 1 and BRG 19 had activity only in phase 2. E122 had no significant activity in either phase. In the hot plate test only E139 had antinociceptive activity. Administration of either bicuculline, a GABAA receptor antagonist, or CGP 35348, a GABAB receptor antagonist, blocked the antinociceptive activity of E139. In conclusion our results indicate that E139 has antinociceptive activity in the formalin and hot plate tests that are dependent on GABA receptors.

Formation of nitric oxide in an industrial burner measured by 2-D laser induced fluorescence

Energy Technology Data Exchange (ETDEWEB)

Arnold, A; Bombach, R; Kaeppeli, B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-06-01

We have performed two-dimensional Laser Induced Fluorescence (2-D LIF) measurements of nitric oxide and hydroxyl radical distributions in an industrial burner at atmospheric pressure. The relative 2-D LIF data of NO were set to an absolute scale by calibration with probe sampling combined with gas analysis. (author) 3 figs., 7 refs.

Sputtering of amorphous carbon layers studied by laser induced fluorescence

International Nuclear Information System (INIS)

Pasch, E.

1992-07-01

In order to minimize the radiation losses, it is desirable to keep the plasmas in nuclear fusion devices free of high-Z-impurities. Therefore, the walls of TEXTOR and other tokamaks are covered with thin layers of amorphous carbon layers (a-C:H) or amorphous carbon/boron layers (a-C/B:H). The sputtering behaviour of these layers has been studied under bombardment by Ar + ions with energies of 1.5 keV and current densities of a few mA/cm 2 . Investigations of these coatings were carried out with the object to measure the velocity distribution of the sputtered atoms and the sputtered yields by laser induced fluorescence in the vacuum ultraviolet. (orig.)

Resonance fluorescence and electron spin in semiconductor quantum dots

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yong

2009-11-18

The work presented in this dissertation contains the first observation of spin-resolved resonance fluorescence from a single quantum dot and its application of direct measurement of electron spin dynamics. The Mollow triplet and the Mollow quintuplet, which are the hallmarks of resonance fluorescence, are presented as the non-spin-resolved and spin-resolved resonance fluorescence spectrum, respectively. The negligible laser background contribution, the near pure radiative broadened spectrum and the anti-bunching photon statistics imply the sideband photons are background-free and near transform-limited single photons. This demonstration is a promising step towards the heralded single photon generation and electron spin readout. Instead of resolving spectrum, an alternative spin-readout scheme by counting resonance fluorescence photons under moderate laser power is demonstrated. The measurements of n-shot time-resolved resonance fluorescence readout are carried out to reveal electron spin dynamics of the measurement induced back action and the spin relaxation. Hyperfine interaction and heavy-light hole mixing are identified as the relevant mechanisms for the back action and phonon-assistant spin-orbit interaction dominates the spin relaxation. After a detailed discussion on charge-spin configurations in coupled quantum dots system, the single-shot readout on electron spin are proposed. (orig.)

Resonance fluorescence and electron spin in semiconductor quantum dots

International Nuclear Information System (INIS)

Zhao, Yong

2009-01-01

The work presented in this dissertation contains the first observation of spin-resolved resonance fluorescence from a single quantum dot and its application of direct measurement of electron spin dynamics. The Mollow triplet and the Mollow quintuplet, which are the hallmarks of resonance fluorescence, are presented as the non-spin-resolved and spin-resolved resonance fluorescence spectrum, respectively. The negligible laser background contribution, the near pure radiative broadened spectrum and the anti-bunching photon statistics imply the sideband photons are background-free and near transform-limited single photons. This demonstration is a promising step towards the heralded single photon generation and electron spin readout. Instead of resolving spectrum, an alternative spin-readout scheme by counting resonance fluorescence photons under moderate laser power is demonstrated. The measurements of n-shot time-resolved resonance fluorescence readout are carried out to reveal electron spin dynamics of the measurement induced back action and the spin relaxation. Hyperfine interaction and heavy-light hole mixing are identified as the relevant mechanisms for the back action and phonon-assistant spin-orbit interaction dominates the spin relaxation. After a detailed discussion on charge-spin configurations in coupled quantum dots system, the single-shot readout on electron spin are proposed. (orig.)

X-ray fluorescence microscopy reveals the role of selenium in spermatogenesis

Science.gov (United States)

Kehr, Sebastian; Malinouski, Mikalai; Finney, Lydia; Vogt, Stefan; Labunskyy, Vyacheslav M.; Kasaikina, Marina V.; Carlson, Bradley A.; Zhou, You; Hatfield, Dolph L.; Gladyshev, Vadim N.

2009-01-01

Selenium (Se) is a trace element with important roles in human health. Several selenoproteins have essential functions in development. However, the cellular and tissue distribution of Se remains largely unknown because of the lack of analytical techniques that image this element with sufficient sensitivity and resolution. Herein, we report that X-ray fluorescence microscopy (XFM) can be used to visualize and quantify the tissue, cellular and subcellular topography of Se. We applied this technique to characterize the role of Se in spermatogenesis and identified a dramatic Se enrichment specifically in late spermatids, a pattern that was not seen in any other elemental maps. This enrichment was due to elevated levels of the mitochondrial form of glutathione peroxidase 4 and was fully dependent on the supplies of Se by Selenoprotein P. High-resolution scans revealed that Se concentrated near the lumen side of elongating spermatids, where structural components of sperm are formed. During spermatogenesis, maximal Se associated with decreased phosphorus, whereas Zn did not change. In sperm, Se was primarily in the midpiece and co-localized with Cu and Fe. XFM allowed quantification of Se in the midpiece (0.8 fg) and head (0.14 fg) of individual sperm cells, revealing the ability of sperm cells to handle the amounts of this element well above its toxic levels. Overall, the use of XFM allowed visualization of tissue and cellular Se and provided important insights in the role of this and other trace elements in spermatogenesis. PMID:19379757

Biomedical analysis of formalin-fixed, paraffin-embedded tissue samples: The Holy Grail for molecular diagnostics.

Science.gov (United States)

Donczo, Boglarka; Guttman, Andras

2018-06-05

More than a century ago in 1893, a revolutionary idea about fixing biological tissue specimens was introduced by Ferdinand Blum, a German physician. Since then, a plethora of fixation methods have been investigated and used. Formalin fixation with paraffin embedment became the most widely used types of fixation and preservation method, due to its proper architectural conservation of tissue structures and cellular shape. The huge collection of formalin-fixed, paraffin-embedded (FFPE) sample archives worldwide holds a large amount of unearthed information about diseases that could be the Holy Grail in contemporary biomarker research utilizing analytical omics based molecular diagnostics. The aim of this review is to critically evaluate the omics options for FFPE tissue sample analysis in the molecular diagnostics field. Copyright © 2018. Published by Elsevier B.V.

Suppression of Kasha's rule as a mechanism for fluorescent molecular rotors and aggregation-induced emission

Science.gov (United States)

Qian, Hai; Cousins, Morgan E.; Horak, Erik H.; Wakefield, Audrey; Liptak, Matthew D.; Aprahamian, Ivan

2017-01-01

Although there are some proposed explanations for aggregation-induced emission, a phenomenon with applications that range from biosensors to organic light-emitting diodes, current understanding of the quantum-mechanical origin of this photophysical behaviour is limited. To address this issue, we assessed the emission properties of a series of BF2-hydrazone-based dyes as a function of solvent viscosity. These molecules turned out to be highly efficient fluorescent molecular rotors. This property, in addition to them being aggregation-induced emission luminogens, enabled us to probe deeper into their emission mechanism. Time-dependent density functional theory calculations and experimental results showed that the emission is not from the S1 state, as predicted from Kasha's rule, but from a higher energy (>S1) state. Furthermore, we found that suppression of internal conversion to the dark S1 state by restricting the rotor rotation enhances fluorescence, which leads to the proposal that suppression of Kasha's rule is the photophysical mechanism responsible for emission in both viscous solution and the solid state.

Direct on-strip analysis of size- and time-resolved aerosol impactor samples using laser induced fluorescence spectra excited at 263 and 351 nm

International Nuclear Information System (INIS)

Wang, Chuji; Pan, Yong-Le; James, Deryck; Wetmore, Alan E.; Redding, Brandon

2014-01-01

Highlights: • A dual wavelength UV-LIF spectra-rotating drum impactor (RDI) technique was developed. • The technique was demonstrated by direct on-strip analysis of size- and time-resolved LIF spectra of atmospheric aerosol particles. • More than 2000 LIF spectra of atmospheric aerosol particles collected over three weeks in Djibouti were obtained and assigned to various fluorescence clusters. • The LIF spectra showed size- and time-sensitivity behavior with a time resolution of 3.6 h. - Abstract: We report a novel atmospheric aerosol characterization technique, in which dual wavelength UV laser induced fluorescence (LIF) spectrometry marries an eight-stage rotating drum impactor (RDI), namely UV-LIF-RDI, to achieve size- and time-resolved analysis of aerosol particles on-strip. The UV-LIF-RDI technique measured LIF spectra via direct laser beam illumination onto the particles that were impacted on a RDI strip with a spatial resolution of 1.2 mm, equivalent to an averaged time resolution in the aerosol sampling of 3.6 h. Excited by a 263 nm or 351 nm laser, more than 2000 LIF spectra within a 3-week aerosol collection time period were obtained from the eight individual RDI strips that collected particles in eight different sizes ranging from 0.09 to 10 μm in Djibouti. Based on the known fluorescence database from atmospheric aerosols in the US, the LIF spectra obtained from the Djibouti aerosol samples were found to be dominated by fluorescence clusters 2, 5, and 8 (peaked at 330, 370, and 475 nm) when excited at 263 nm and by fluorescence clusters 1, 2, 5, and 6 (peaked at 390 and 460 nm) when excited at 351 nm. Size- and time-dependent variations of the fluorescence spectra revealed some size and time evolution behavior of organic and biological aerosols from the atmosphere in Djibouti. Moreover, this analytical technique could locate the possible sources and chemical compositions contributing to these fluorescence clusters. Advantages, limitations, and

Direct on-strip analysis of size- and time-resolved aerosol impactor samples using laser induced fluorescence spectra excited at 263 and 351 nm

Energy Technology Data Exchange (ETDEWEB)

Wang, Chuji [U.S. Army Research Laboratory, Adelphi, MD 20783 (United States); Mississippi State University, Starkville, MS, 39759 (United States); Pan, Yong-Le, E-mail: yongle.pan.civ@mail.mil [U.S. Army Research Laboratory, Adelphi, MD 20783 (United States); James, Deryck; Wetmore, Alan E. [U.S. Army Research Laboratory, Adelphi, MD 20783 (United States); Redding, Brandon [Yale University, New Haven, CT 06510 (United States)

2014-04-01

Highlights: • A dual wavelength UV-LIF spectra-rotating drum impactor (RDI) technique was developed. • The technique was demonstrated by direct on-strip analysis of size- and time-resolved LIF spectra of atmospheric aerosol particles. • More than 2000 LIF spectra of atmospheric aerosol particles collected over three weeks in Djibouti were obtained and assigned to various fluorescence clusters. • The LIF spectra showed size- and time-sensitivity behavior with a time resolution of 3.6 h. - Abstract: We report a novel atmospheric aerosol characterization technique, in which dual wavelength UV laser induced fluorescence (LIF) spectrometry marries an eight-stage rotating drum impactor (RDI), namely UV-LIF-RDI, to achieve size- and time-resolved analysis of aerosol particles on-strip. The UV-LIF-RDI technique measured LIF spectra via direct laser beam illumination onto the particles that were impacted on a RDI strip with a spatial resolution of 1.2 mm, equivalent to an averaged time resolution in the aerosol sampling of 3.6 h. Excited by a 263 nm or 351 nm laser, more than 2000 LIF spectra within a 3-week aerosol collection time period were obtained from the eight individual RDI strips that collected particles in eight different sizes ranging from 0.09 to 10 μm in Djibouti. Based on the known fluorescence database from atmospheric aerosols in the US, the LIF spectra obtained from the Djibouti aerosol samples were found to be dominated by fluorescence clusters 2, 5, and 8 (peaked at 330, 370, and 475 nm) when excited at 263 nm and by fluorescence clusters 1, 2, 5, and 6 (peaked at 390 and 460 nm) when excited at 351 nm. Size- and time-dependent variations of the fluorescence spectra revealed some size and time evolution behavior of organic and biological aerosols from the atmosphere in Djibouti. Moreover, this analytical technique could locate the possible sources and chemical compositions contributing to these fluorescence clusters. Advantages, limitations, and

Variability of sun-induced chlorophyll fluorescence according to stand age-related processes in a managed loblolly pine forest.

Science.gov (United States)

Colombo, Roberto; Celesti, Marco; Bianchi, Remo; Campbell, Petya K E; Cogliati, Sergio; Cook, Bruce D; Corp, Lawrence A; Damm, Alexander; Domec, Jean-Christophe; Guanter, Luis; Julitta, Tommaso; Middleton, Elizabeth M; Noormets, Asko; Panigada, Cinzia; Pinto, Francisco; Rascher, Uwe; Rossini, Micol; Schickling, Anke

2018-02-20

Leaf fluorescence can be used to track plant development and stress, and is considered the most direct measurement of photosynthetic activity available from remote sensing techniques. Red and far-red sun-induced chlorophyll fluorescence (SIF) maps were generated from high spatial resolution images collected with the HyPlant airborne spectrometer over even-aged loblolly pine plantations in North Carolina (United States). Canopy fluorescence yield (i.e., the fluorescence flux normalized by the light absorbed) in the red and far-red peaks was computed. This quantifies the fluorescence emission efficiencies that are more directly linked to canopy function compared to SIF radiances. Fluorescence fluxes and yields were investigated in relation to tree age to infer new insights on the potential of those measurements in better describing ecosystem processes. The results showed that red fluorescence yield varies with stand age. Young stands exhibited a nearly twofold higher red fluorescence yield than mature forest plantations, while the far-red fluorescence yield remained constant. We interpreted this finding in a context of photosynthetic stomatal limitation in aging loblolly pine stands. Current and future satellite missions provide global datasets of SIF at coarse spatial resolution, resulting in intrapixel mixture effects, which could be a confounding factor for fluorescence signal interpretation. To mitigate this effect, we propose a surrogate of the fluorescence yield, namely the Canopy Cover Fluorescence Index (CCFI) that accounts for the spatial variability in canopy structure by exploiting the vegetation fractional cover. It was found that spatial aggregation tended to mask the effective relationships, while the CCFI was still able to maintain this link. This study is a first attempt in interpreting the fluorescence variability in aging forest stands and it may open new perspectives in understanding long-term forest dynamics in response to future climatic

Differential laser-induced perturbation spectroscopy and fluorescence imaging for biological and materials sensing

Science.gov (United States)

Burton, Dallas Jonathan

The field of laser-based diagnostics has been a topic of research in various fields, more specifically for applications in environmental studies, military defense technologies, and medicine, among many others. In this dissertation, a novel laser-based optical diagnostic method, differential laser-induced perturbation spectroscopy (DLIPS), has been implemented in a spectroscopy mode and expanded into an imaging mode in combination with fluorescence techniques. The DLIPS method takes advantage of deep ultraviolet (UV) laser perturbation at sub-ablative energy fluences to photochemically cleave bonds and alter fluorescence signal response before and after perturbation. The resulting difference spectrum or differential image adds more information about the target specimen, and can be used in combination with traditional fluorescence techniques for detection of certain materials, characterization of many materials and biological specimen, and diagnosis of various human skin conditions. The differential aspect allows for mitigation of patient or sample variation, and has the potential to develop into a powerful, noninvasive optical sensing tool. The studies in this dissertation encompass efforts to continue the fundamental research on DLIPS including expansion of the method to an imaging mode. Five primary studies have been carried out and presented. These include the use of DLIPS in a spectroscopy mode for analysis of nitrogen-based explosives on various substrates, classification of Caribbean fruit flies versus Caribbean fruit flies that have been irradiated with gamma rays, and diagnosis of human skin cancer lesions. The nitrogen-based explosives and Caribbean fruit flies have been analyzed with the DLIPS scheme using the imaging modality, providing complementary information to the spectroscopic scheme. In each study, a comparison between absolute fluorescence signals and DLIPS responses showed that DLIPS statistically outperformed traditional fluorescence techniques

Inducing fluorescence of uranyl acetate as a dual-purpose contrast agent for correlative light-electron microscopy with nanometre precision.

Science.gov (United States)

Tuijtel, Maarten W; Mulder, Aat A; Posthuma, Clara C; van der Hoeven, Barbara; Koster, Abraham J; Bárcena, Montserrat; Faas, Frank G A; Sharp, Thomas H

2017-09-05

Correlative light-electron microscopy (CLEM) combines the high spatial resolution of transmission electron microscopy (TEM) with the capability of fluorescence light microscopy (FLM) to locate rare or transient cellular events within a large field of view. CLEM is therefore a powerful technique to study cellular processes. Aligning images derived from both imaging modalities is a prerequisite to correlate the two microscopy data sets, and poor alignment can limit interpretability of the data. Here, we describe how uranyl acetate, a commonly-used contrast agent for TEM, can be induced to fluoresce brightly at cryogenic temperatures (-195 °C) and imaged by cryoFLM using standard filter sets. This dual-purpose contrast agent can be used as a general tool for CLEM, whereby the equivalent staining allows direct correlation between fluorescence and TEM images. We demonstrate the potential of this approach by performing multi-colour CLEM of cells containing equine arteritis virus proteins tagged with either green- or red-fluorescent protein, and achieve high-precision localization of virus-induced intracellular membrane modifications. Using uranyl acetate as a dual-purpose contrast agent, we achieve an image alignment precision of ~30 nm, twice as accurate as when using fiducial beads, which will be essential for combining TEM with the evolving field of super-resolution light microscopy.

Initial operation of the LEDA beam-induced fluorescence diagnostic

International Nuclear Information System (INIS)

Kamperschroer, James H.; Gurd, Pamela A.; Martinez, Derwin G.; Gilpatrick, J. Douglas; Shurter, R. Bradford; Stettler, Matthew W.; Madsen, David W.; O'Hara, James F.; Sage, Joan; Schaefer, Timothy L.

2000-01-01

A diagnostic based on beam-induced fluorescence has been developed and used to examine the expanded beam in the High-Energy Beam Transport (HEBT) section of the Low Energy Demonstration Accelerator (LEDA). The system consists of a camera, a gas injector, a spectrometer, and a control system. Gas is injected to provide a medium for the beam to excite, the camera captures the resulting image of the fluorescing gas, and the spectrometer measures the spectrum of the emitted light. EPICS was used to control the camera and acquire and store images. Data analysis is presently being performed offline. A Kodak DCS420m professional CCD camera is the primary component of the optical system. InterScience, Inc. modified the camera with the addition of a gain of 4000 image intensifier, thereby producing an intensified camera with a sensitivity of ∼0.5 milli-lux. Light is gathered with a 1 '' format, 16-160 mm, Computar zoom lens. This lens is attached to the camera via a Century Precision Optics relay lens. Images obtained using only hydrogen from the beam stop exhibited features not yet understood. Images with good signal-to-noise ratio were obtained with the injection of sufficient nitrogen to raise the HEBT pressure to 2-8x10 -6 torr. Two strong nitrogen lines, believed to be of the first negative group of N 2 + , were identified at 391 and 428 nm

X-Ray Fluorescence and Laser-Induced Breakdown Spectroscopy analysis of Roman silver denarii

Energy Technology Data Exchange (ETDEWEB)

Pardini, L. [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); El Hassan, A. [National Institute for Laser- Enhanced Sciences (NILES), Cairo University Giza (Egypt); Ferretti, M. [Istituto per le Tecnologie Applicate ai Beni Culturali, Area della Ricerca del CNR di Montelibretti Roma (Italy); Foresta, A.; Legnaioli, S.; Lorenzetti, G. [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Nebbia, E. [Universita degli Studi di Torino (Italy); Catalli, F. [Monetiere di Firenze, Museo Archeologico Nazionale Firenze (Italy); Harith, M.A. [National Institute for Laser- Enhanced Sciences (NILES), Cairo University Giza (Egypt); Diaz Pace, D. [Institute of Physics ' Arroyo Seco' , Faculty of Science, Tandil (Argentina); Anabitarte Garcia, F. [Photonics Engineering Group, University of Cantabria, Santander (Spain); Scuotto, M. [Dipartimento di Scienze Archeologiche, Via Galvani 1, 56126 Pisa (Italy); Palleschi, V., E-mail: vincenzo.palleschi@cnr.it [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Dipartimento di Scienze Archeologiche, Via Galvani 1, 56126 Pisa (Italy)

2012-08-15

In this paper we present the results of a study performed on a large collection of silver Roman republican denarii, encompassing about two centuries of history. The joint use of Laser-Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF) spectroscopy allowed for an accurate determination of the coins' elemental composition; the measurements, performed mostly in situ at the 'Monetiere' in Florence, revealed a striking connection between the 'quality' of the silver alloy and some crucial contemporary events. This finding was used to classify a group of denarii whose dating was otherwise impossible. The comparison with other contemporary denarii disproves a recent theory on the origin of the so called 'serrated' denarii (denarii showing notched chisel marks on the edge of the coin). - Highlights: Black-Right-Pointing-Pointer We studied a large collection of Roman republican silver denarii. Black-Right-Pointing-Pointer XRF and LIBS allowed to determine the precious metal content of the coins. Black-Right-Pointing-Pointer A correlation of the 'quality' of the alloy with some contemporary events was found. Black-Right-Pointing-Pointer The study allowed to controvert a recent theory on the so called 'serrated' denarii.

Measurements of KrF laser-induced O2 fluorescence in high-temperature atmospheric air

Science.gov (United States)

Grinstead, Jay H.; Laufer, Gabriel; Mcdaniel, James C., Jr.

1993-01-01

Conditions for obtaining laser-induced O2 fluorescence using a tunable KrF laser has been determined theoretically and experimentally. With this laser source, O2 rotational temperature measurement is possible even in the absence of vibrational equilibrium. Temperature measurement using a two-line excitation scheme has been demonstrated in a high-temperature atmospheric-air furnace. A measurement uncertainty of 10.7 percent for the temperature range 1325-1725 K was realized. At atmospheric pressure, O2 LIF measurements are possible for air temperatures above 1250 K. Interference from OH fluorescence in reacting flows can be avoided by the proper selection of O2 transitions. Depletion of the ground state population by the incident laser is negligible for intensities below 7.5 x 10 to the 6th W/sq cm/per cm.

A study of the interaction between malachite green and lysozyme by steady-state fluorescence.

Science.gov (United States)

Ding, Fei; Liu, Wei; Liu, Feng; Li, Zhi-Yuan; Sun, Ying

2009-09-01

The interaction of a N-methylated diaminotriphenylmethane dye, malachite green, with lysozyme was investigated by fluorescence spectroscopic techniques under physiological conditions. The binding parameters have been evaluated by fluorescence quenching methods. The results revealed that malachite green caused the fluorescence quenching of lysozyme through a static quenching procedure. The thermodynamic parameters like DeltaH and DeltaS were calculated to be -15.33 kJ mol(-1) and 19.47 J mol(-1) K(-1) according to van't Hoff equation, respectively, which proves main interaction between malachite green and lysozyme is hydrophobic forces and hydrogen bond contact. The distance r between donor (lysozyme) and acceptor (malachite green) was obtained to be 3.82 nm according to Frster's theory. The results of synchronous fluorescence, UV/vis and three-dimensional fluorescence spectra showed that binding of malachite green with lysozyme can induce conformational changes in lysozyme. In addition, the effects of common ions on the constants of lysozyme-malachite green complex were also discussed.

Near-infrared II fluorescence for imaging hindlimb vessel regeneration with dynamic tissue perfusion measurement.

Science.gov (United States)

Hong, Guosong; Lee, Jerry C; Jha, Arshi; Diao, Shuo; Nakayama, Karina H; Hou, Luqia; Doyle, Timothy C; Robinson, Joshua T; Antaris, Alexander L; Dai, Hongjie; Cooke, John P; Huang, Ngan F

2014-05-01

Real-time vascular imaging that provides both anatomic and hemodynamic information could greatly facilitate the diagnosis of vascular diseases and provide accurate assessment of therapeutic effects. Here, we have developed a novel fluorescence-based all-optical method, named near-infrared II (NIR-II) fluorescence imaging, to image murine hindlimb vasculature and blood flow in an experimental model of peripheral arterial disease, by exploiting fluorescence in the NIR-II region (1000-1400 nm) of photon wavelengths. Because of the reduced photon scattering of NIR-II fluorescence compared with traditional NIR fluorescence imaging and thus much deeper penetration depth into the body, we demonstrated that the mouse hindlimb vasculature could be imaged with higher spatial resolution than in vivo microscopic computed tomography. Furthermore, imaging during 26 days revealed a significant increase in hindlimb microvascular density in response to experimentally induced ischemia within the first 8 days of the surgery (Pimaging make it a useful imaging tool for murine models of vascular disease. © 2014 American Heart Association, Inc.

Smartphone Cortex Controlled Real-Time Image Processing and Reprocessing for Concentration Independent LED Induced Fluorescence Detection in Capillary Electrophoresis.

Science.gov (United States)

Szarka, Mate; Guttman, Andras

2017-10-17

We present the application of a smartphone anatomy based technology in the field of liquid phase bioseparations, particularly in capillary electrophoresis. A simple capillary electrophoresis system was built with LED induced fluorescence detection and a credit card sized minicomputer to prove the concept of real time fluorescent imaging (zone adjustable time-lapse fluorescence image processor) and separation controller. The system was evaluated by analyzing under- and overloaded aminopyrenetrisulfonate (APTS)-labeled oligosaccharide samples. The open source software based image processing tool allowed undistorted signal modulation (reprocessing) if the signal was inappropriate for the actual detection system settings (too low or too high). The novel smart detection tool for fluorescently labeled biomolecules greatly expands dynamic range and enables retrospective correction for injections with unsuitable signal levels without the necessity to repeat the analysis.

Stereoscopic Planar Laser-Induced Fluorescence Imaging at 500 kHz

Science.gov (United States)

Medford, Taylor L.; Danehy, Paul M.; Jones, Stephen B.; Jiang, N.; Webster, M.; Lempert, Walter; Miller, J.; Meyer, T.

2011-01-01

A new measurement technique for obtaining time- and spatially-resolved image sequences in hypersonic flows is developed. Nitric-oxide planar laser-induced fluorescence (NO PLIF) has previously been used to investigate transition from laminar to turbulent flow in hypersonic boundary layers using both planar and volumetric imaging capabilities. Low flow rates of NO were typically seeded into the flow, minimally perturbing the flow. The volumetric imaging was performed at a measurement rate of 10 Hz using a thick planar laser sheet that excited NO fluorescence. The fluorescence was captured by a pair of cameras having slightly different views of the flow. Subsequent stereoscopic reconstruction of these images allowed the three-dimensional flow structures to be viewed. In the current paper, this approach has been extended to 50,000 times higher repetition rates. A laser operating at 500 kHz excites the seeded NO molecules, and a camera, synchronized with the laser and fitted with a beam-splitting assembly, acquires two separate images of the flow. The resulting stereoscopic images provide three-dimensional flow visualizations at 500 kHz for the first time. The 200 ns exposure time in each frame is fast enough to freeze the flow while the 500 kHz repetition rate is fast enough to time-resolve changes in the flow being studied. This method is applied to visualize the evolving hypersonic flow structures that propagate downstream of a discrete protuberance attached to a flat plate. The technique was demonstrated in the NASA Langley Research Center s 31-Inch Mach 10 Air Tunnel facility. Different tunnel Reynolds number conditions, NO flow rates and two different cylindrical protuberance heights were investigated. The location of the onset of flow unsteadiness, an indicator of transition, was observed to move downstream during the tunnel runs, coinciding with an increase in the model temperature.

Argon Plasma Coagulation Therapy Versus Topical Formalin for Intractable Rectal Bleeding and Anorectal Dysfunction After Radiation Therapy for Prostate Carcinoma

Energy Technology Data Exchange (ETDEWEB)

Yeoh, Eric, E-mail: eric.yeoh@health.sa.gov.au [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide (Australia); School of Medicine, University of Adelaide, Adelaide (Australia); Tam, William; Schoeman, Mark [School of Medicine, University of Adelaide, Adelaide (Australia); Department of Gastroenterology, Royal Adelaide Hospital, Adelaide (Australia); Moore, James; Thomas, Michelle [School of Medicine, University of Adelaide, Adelaide (Australia); Department of Colorectal Surgery, Royal Adelaide Hospital, Adelaide (Australia); Botten, Rochelle; Di Matteo, Addolorata [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide (Australia)

2013-12-01

Purpose: To evaluate and compare the effect of argon plasma coagulation (APC) and topical formalin for intractable rectal bleeding and anorectal dysfunction associated with chronic radiation proctitis. Methods and Materials: Thirty men (median age, 72 years; range, 49-87 years) with intractable rectal bleeding (defined as ≥1× per week and/or requiring blood transfusions) after radiation therapy for prostate carcinoma were randomized to treatment with APC (n=17) or topical formalin (n=13). Each patient underwent evaluations of (1) anorectal symptoms (validated questionnaires, including modified Late Effects in Normal Tissues–Subjective, Objective, Management, and Analytic and visual analogue scales for rectal bleeding); (2) anorectal motor and sensory function (manometry and graded rectal balloon distension); and (3) anal sphincteric morphology (endoanal ultrasound) before and after the treatment endpoint (defined as reduction in rectal bleeding to 1× per month or better, reduction in visual analogue scales to ≤25 mm, and no longer needing blood transfusions). Results: The treatment endpoint was achieved in 94% of the APC group and 100% of the topical formalin group after a median (range) of 2 (1-5) sessions of either treatment. After a follow-up duration of 111 (29-170) months, only 1 patient in each group needed further treatment. Reductions in rectal compliance and volumes of sensory perception occurred after APC, but no effect on anorectal symptoms other than rectal bleeding was observed. There were no differences between APC and topical formalin for anorectal symptoms and function, nor for anal sphincteric morphology. Conclusions: Argon plasma coagulation and topical formalin had comparable efficacy in the durable control of rectal bleeding associated with chronic radiation proctitis but had no beneficial effect on anorectal dysfunction.

Argon Plasma Coagulation Therapy Versus Topical Formalin for Intractable Rectal Bleeding and Anorectal Dysfunction After Radiation Therapy for Prostate Carcinoma

International Nuclear Information System (INIS)

Yeoh, Eric; Tam, William; Schoeman, Mark; Moore, James; Thomas, Michelle; Botten, Rochelle; Di Matteo, Addolorata

2013-01-01

Purpose: To evaluate and compare the effect of argon plasma coagulation (APC) and topical formalin for intractable rectal bleeding and anorectal dysfunction associated with chronic radiation proctitis. Methods and Materials: Thirty men (median age, 72 years; range, 49-87 years) with intractable rectal bleeding (defined as ≥1× per week and/or requiring blood transfusions) after radiation therapy for prostate carcinoma were randomized to treatment with APC (n=17) or topical formalin (n=13). Each patient underwent evaluations of (1) anorectal symptoms (validated questionnaires, including modified Late Effects in Normal Tissues–Subjective, Objective, Management, and Analytic and visual analogue scales for rectal bleeding); (2) anorectal motor and sensory function (manometry and graded rectal balloon distension); and (3) anal sphincteric morphology (endoanal ultrasound) before and after the treatment endpoint (defined as reduction in rectal bleeding to 1× per month or better, reduction in visual analogue scales to ≤25 mm, and no longer needing blood transfusions). Results: The treatment endpoint was achieved in 94% of the APC group and 100% of the topical formalin group after a median (range) of 2 (1-5) sessions of either treatment. After a follow-up duration of 111 (29-170) months, only 1 patient in each group needed further treatment. Reductions in rectal compliance and volumes of sensory perception occurred after APC, but no effect on anorectal symptoms other than rectal bleeding was observed. There were no differences between APC and topical formalin for anorectal symptoms and function, nor for anal sphincteric morphology. Conclusions: Argon plasma coagulation and topical formalin had comparable efficacy in the durable control of rectal bleeding associated with chronic radiation proctitis but had no beneficial effect on anorectal dysfunction

A Class I UV-blocking (senofilcon A) soft contact lens prevents UVA-induced yellow fluorescence and NADH loss in the rabbit lens nucleus in vivo.

Science.gov (United States)

Giblin, Frank J; Lin, Li-Ren; Simpanya, Mukoma F; Leverenz, Victor R; Fick, Catherine E

2012-09-01

It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm(2) on the cornea) for 1 h using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 h. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear �

Reconstructed Solar-Induced Fluorescence: A Machine Learning Vegetation Product Based on MODIS Surface Reflectance to Reproduce GOME-2 Solar-Induced Fluorescence

Science.gov (United States)

Gentine, P.; Alemohammad, S. H.

2018-04-01

Solar-induced fluorescence (SIF) observations from space have resulted in major advancements in estimating gross primary productivity (GPP). However, current SIF observations remain spatially coarse, infrequent, and noisy. Here we develop a machine learning approach using surface reflectances from Moderate Resolution Imaging Spectroradiometer (MODIS) channels to reproduce SIF normalized by clear sky surface irradiance from the Global Ozone Monitoring Experiment-2 (GOME-2). The resulting product is a proxy for ecosystem photosynthetically active radiation absorbed by chlorophyll (fAPARCh). Multiplying this new product with a MODIS estimate of photosynthetically active radiation provides a new MODIS-only reconstruction of SIF called Reconstructed SIF (RSIF). RSIF exhibits much higher seasonal and interannual correlation than the original SIF when compared with eddy covariance estimates of GPP and two reference global GPP products, especially in dry and cold regions. RSIF also reproduces intense productivity regions such as the U.S. Corn Belt contrary to typical vegetation indices and similarly to SIF.

Portable detection system of vegetable oils based on laser induced fluorescence

Science.gov (United States)

Zhu, Li; Zhang, Yinchao; Chen, Siying; Chen, He; Guo, Pan; Mu, Taotao

2015-11-01

Food safety, especially edible oils, has attracted more and more attention recently. Many methods and instruments have emerged to detect the edible oils, which include oils classification and adulteration. It is well known than the adulteration is based on classification. Then, in this paper, a portable detection system, based on laser induced fluorescence, is proposed and designed to classify the various edible oils, including (olive, rapeseed, walnut, peanut, linseed, sunflower, corn oils). 532 nm laser modules are used in this equipment. Then, all the components are assembled into a module (100*100*25mm). A total of 700 sets of fluorescence data (100 sets of each type oil) are collected. In order to classify different edible oils, principle components analysis and support vector machine have been employed in the data analysis. The training set consisted of 560 sets of data (80 sets of each oil) and the test set consisted of 140 sets of data (20 sets of each oil). The recognition rate is up to 99%, which demonstrates the reliability of this potable system. With nonintrusive and no sample preparation characteristic, the potable system can be effectively applied for food detection.

Analysis of Red and Far-Red Sun-Induced Chlorophyll Fluorescence and Their Ratio in Different Canopies Based on Observed and Modeled Data

Directory of Open Access Journals (Sweden)

Micol Rossini

2016-05-01

Full Text Available Sun-induced canopy chlorophyll fluorescence in both the red (FR and far-red (FFR regions was estimated across a range of temporal scales and a range of species from different plant functional types using high resolution radiance spectra collected on the ground. Field measurements were collected with a state-of-the-art spectrometer setup and standardized methodology. Results showed that different plant species were characterized by different fluorescence magnitude. In general, the highest fluorescence emissions were measured in crops followed by broadleaf and then needleleaf species. Red fluorescence values were generally lower than those measured in the far-red region due to the reabsorption of FR by photosynthetic pigments within the canopy layers. Canopy chlorophyll fluorescence was related to plant photosynthetic capacity, but also varied according to leaf and canopy characteristics, such as leaf chlorophyll concentration and Leaf Area Index (LAI. Results gathered from field measurements were compared to radiative transfer model simulations with the Soil-Canopy Observation of Photochemistry and Energy fluxes (SCOPE model. Overall, simulation results confirmed a major contribution of leaf chlorophyll concentration and LAI to the fluorescence signal. However, some discrepancies between simulated and experimental data were found in broadleaf species. These discrepancies may be explained by uncertainties in individual species LAI estimation in mixed forests or by the effect of other model parameters and/or model representation errors. This is the first study showing sun-induced fluorescence experimental data on the variations in the two emission regions and providing quantitative information about the absolute magnitude of fluorescence emission from a range of vegetation types.

Measurement of isotope shift of recycled uranium by laser induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Oba, Masaki; Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi

1999-07-01

Isotope shift of the recycled uranium atoms including the 236 U was measured by laser induced fluorescence method. Eight even levels at 2 eV and three odd levels at 4 eV were measured with isotope shifts among 238 U, 236 U and 235 U obtained. As for the measurement of the 4 eV levels, the Doppler free two photon absorption method was used, and the hyperfine structure of the 235 U was analyzed simultaneously. The isotope shift of 234 U was also observed in the three transition. (J.P.N.)

Shedding light on disulfide bond formation: engineering a redox switch in green fluorescent protein

DEFF Research Database (Denmark)

Østergaard, H.; Henriksen, A.; Hansen, Flemming G.

2001-01-01

To visualize the formation of disulfide bonds in living cells, a pair of redox-active cysteines was introduced into the yellow fluorescent variant of green fluorescent protein. Formation of a disulfide bond between the two cysteines was fully reversible and resulted in a >2-fold decrease...... in the intrinsic fluorescence. Inter conversion between the two redox states could thus be followed in vitro as well as in vivoby non- invasive fluorimetric measurements. The 1.5 Angstrom crystal structure of the oxidized protein revealed a disulfide bond- induced distortion of the beta -barrel, as well...... the physiological range for redox-active cysteines. In the cytoplasm of Escherichia coli, the protein was a sensitive probe for the redox changes that occur upon disruption of the thioredoxin reductive pathway....

Fluorescence Indices for the Proximal Sensing of Powdery Mildew, Nitrogen Supply and Water Deficit in Sugar Beet Leaves

Directory of Open Access Journals (Sweden)

Georg Leufen

2014-03-01

Full Text Available Using potted sugar beet plants we aimed to investigate the suitability of four fluorescence indices to detect and differentiate the impact of nitrogen supply, water deficit and powdery mildew in two sugar beet cultivars (Beta vulgaris L.. Plants were grown inside a polytunnel under two nitrogen levels combined with water deficit or full irrigation. Changes in plant physiology were recorded at two physiological stages with a multiparametric handheld fluorescence sensor and a fluorescence imaging system. The analysis of chlorophyll content and osmotic potential served as reference. Based on our results, the fluorescence indices “Nitrogen Balance Index” and “Simple Fluorescence Ratio” responded quite sensitively to drought stress and mildew infection. Moreover, the blue-to-far-red fluorescence ratio revealed significant stress-induced alterations in the plant physiology. In all, fluorescence indices might be used as single or combined indices for successful stress sensing. However, a robust stress differentiation by using only one fluorescence ratio could not be accomplished.

L G-2 Scintrex manual.Fluorescence analyzer

International Nuclear Information System (INIS)

Pirelli, H.

1987-01-01

The Scintrex Fluorescence Analyzer LG-2 selectively detects the presence of certain fluorescent minerals through UV photoluminescence induced and provides quantitative information on its distribution.

Fluorescence detection of oral squamous cell carcinoma using Hyperflav

Science.gov (United States)

Melnik, Ivan S.; Dets, Sergiy M.; Rawicz, Andrew H.; Zhang, Lewei

2000-05-01

A novel hypericin-based drug HyperflavTM has been evaluated for light-induced fluorescence detection of oral cancer. Squamous cell carcinoma was induced with carcinogenic agent in right pouches of forty hamsters (20/20 males/females). Solution of HyperflavTM was sprinkled into stomach with a single dose 0.2 - 4 mg of pure hypericin per kg b.w. and 4 - 8 hours before fluorescence analysis. In two animal groups with cancer symptoms the autofluorescence and hypericin-induced fluorescence were taken under 442 nm excitation. The buccal mucosa and adjacent areas were measured fiberoptically in-vivo and in-vitro using orange/green ratio (610/540). The in-vivo fluorescence imaging of malignant areas was conducted to assist the biopsy guidance and to compare with white-light images. Histological and morphological analyses were performed from biopsies. Oral squamous cell carcinoma in its early stage demonstrated specific higher 610/540 ratio for 37 tested hamsters. Advanced state involved another higher fluorescence maximum around 640 nm that in our opinion caused by strong porphyrin-induced native fluorescence. Such deformation of fluorescence spectra may lead to inadequate perception of diseased tissue area. To avoid this problem the autofluorescence spectra & images were added. HyperflavTM application is promising for demarcation of early oral cancer when combined with autofluorescence measurements.

A method for the measurement of in line pistachio aflatoxin concentration based on the laser induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Paghaleh, Soodeh Jamali; Askari, Hassan Ranjbar; Marashi, Seyed Mohammad Bagher; Rahimi, Mojtaba; Bahrampour, Ali Reza

2015-01-01

Contamination of pistachio nuts with aflatoxin is one of the most significant issues related to pistachio health and expert. A fast pistachio aflatoxin concentration measurement method based on the laser induced fluorescence spectroscopy (LIFS) is proposed. The proposed method from theoretical and experimental points of view is analyzed. In our experiments XeCl Excimer laser is employed as an Ultra Violet (UV) source (λ=308 nm) and a UV–visible (UV–vis) spectrometer is used for fluorescent emission detection. Our setup is employed to measure the concentration of different type of Aflatoxins in pistachio nuts. Measurements results obtained by the LIFS method are compared with those are measured by the standard HPLC method. Aflatoxins concentrations are in good agreement with those are obtained by the HPLC method. The proposed laser induced fluorescence spectroscopy can be used as an in line aflatoxins concentrations measurement instrument for industrial applications. - Highlights: • XeCl Excimer laser is employed as an UV source for measurement of AFs in pistachio nuts. • Results are compared with those are measured by the standard HPLC method. • LIFS is an online AFs concentration measurement method for industrial applications

Two-photon laser-induced fluorescence studies of HS radicals, DS radicals, and I atoms

Energy Technology Data Exchange (ETDEWEB)

Tiee, J J; Ferris, M J; Loge, G W; Wampler, F B

1983-04-15

A two-photon laser-induced excitation and fluorescence technique has been used to study the A /sup 2/..sigma../sup +/ - X/sup 2/PI transition of HS and DS radicals and various high-lying /sup 4/P/sup 0/, /sup 2/D/sup 0/, and /sup 4/D/sup 0/ states of the I atom. The two-photon excitation cross sections and detection sensitivity are discussed. 13 references, 5 figures.

Optogenetic Activation of the Sublaterodorsal (SLD) Nucleus Induces Rapid Muscle Inhibition

Science.gov (United States)

2015-09-01

followed by 10% formalin with 15% sucrose, for cryoprotection. Brains were sectioned at 40 µm and tissue stained for Nissl and green fluorescent...injection location Figure 6A: A coronal brain section from rat CG4: The blue Nissl stain highlights neuronal cell bodies, while the darker black is an...coronal brain section from rat CG3: The blue Nissl stain highlights neuronal cell bodies, while the darker black is an anti-GFP stain to determine

Effect of Saraca asoca (Asoka) on estradiol-induced keratinizing metaplasia in rat uterus.

Science.gov (United States)

Shahid, Adangam Purath; Salini, Sasidharan; Sasidharan, Nanu; Padikkala, Jose; Raghavamenon, Achuthan Chathrattil; Babu, Thekkekara Devassy

2015-09-01

Estrogen-mediated uterus endometrium instability is considered as one of the etiological factors in dysfunctional uterine bleeding (DUB) and uterine cancer. Saraca asoca (Family: Fabaceae) and its fermented preparation, Asokarishta, are extensively used as uterine tonic to treat gynecological disorders in Ayurveda. The present study evaluated the effect of S. asoca (Asoka) on estrogen-induced endometrial thickening of rat uterus. Endometrial thickening was induced by intraperitoneal injection of estradiol (20 μg/kg b.wt) to 8-day-old immature rats for alternate 5 days. Methanolic extract (200 mg/kg b. wt) from S. asoca bark was given orally along with estradiol. Uterus endometrial thickening was analyzed histopathologically and serum estrogen level by radioimmunoassay (RIA). Cyclooxygenase (COX-2) expression in rat uterus was also estimated by Western blot. Anti-inflammatory activity of the extract was analyzed by formalin- and carrageenan-elicited paw edema models in mouse. Uterus endometrium proliferation and keratinized metaplasia with seven to eight stratified epithelial layers on day 16 was observed in rats administered with estradiol. Treatment with S. asoca reduced the thickening to two to four layers and the serum estrogen level diminished significantly to 82.9±12.87 pg/mL compared to rats administered with estrogen alone (111.2±10.68 pg/mL). A reduction of formalin- and carrageenan-induced paw edema in mouse by S. asoca extract was observed. Lower level of lipopolysaccharides (LPS)-induced COX-2 enzyme in rat uterus by the extract further confirms its anti-inflammatory activity. Present study reveals the antiproliferative and antikeratinizing effects of S. asoca in uterus endometrium possibly through its anti-estrogenic and anti-inflammatory properties.

Spatially resolved analyses of uranium species using a coupled system made up of confocal laser-scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS)

International Nuclear Information System (INIS)

Brockmann, S.; Grossmann, K.; Arnold, T.

2014-01-01

The fluorescent properties of uranium when excited by UV light are used increasingly for spectroscope analyses of uranium species within watery samples. Here, alongside the fluorescent properties of the hexavalent oxidation phases, the tetra and pentavalent oxidation phases also play an increasingly important role. The detection of fluorescent emission spectrums on solid and biological samples using (time-resolved) laser induced fluorescence spectroscopy (TRLFS or LIFS respectively) has, however, the disadvantage that no statements regarding the spatial localisation of the uranium can be made. However, particularly in complex, biological samples, such statements on the localisation of the uranium enrichment in the sample are desired, in order to e.g. be able to distinguish between intra and extra-cellular uranium bonds. The fluorescent properties of uranium (VI) compounds and minerals can also be used to detect their localisation within complex samples. So the application of fluorescent microscopic methods represents one possibility to localise and visualise uranium precipitates and enrichments in biological samples, such as biofilms or cells. The confocal laser-scanning microscopy (CLSM) is especially well suited to this purpose. Coupling confocal laser-scanning microscopy (CLSM) with laser induced fluorescence spectroscopy (LIFS) makes it possible to localise and visualise fluorescent signals spatially and three-dimensionally, while at the same time being able to detect spatially resolved, fluorescent-spectroscopic data. This technology is characterised by relatively low detection limits from up to 1.10 -6 M for uranium (VI) compounds within the confocal volume. (orig.)

Fluorescence lifetime microscopy for monitoring cell adhesion using metal induced energy transfer

Science.gov (United States)

Hwang, Wonsang; Seo, JinWon; Song, Jun ho; Kim, DongEun; Won, YoungJae; Choi, In-Hong; Yoo, Kyung-Hwa; Kim, Dug Young

2018-02-01

A precise control and a reliable monitoring tool for the adhesion properties of a cell are very important in atherosclerosis studies. If endothelial cells in contact with the intracellular membrane are not attached securely, low-density lipoprotein (LDL) particles can enter into the inner membrane. It is therefore necessary to measure conditions under which endothelial cell detachment occurs. When a cell is attached to a metal thin film, the lifetime of a fluorescence probe attached to the membrane of the cell is reduced by the metal-induced energy transfer (MIET). Fluorescence lifetime imaging microscopy (FLIM) is used to monitor the attachment condition of a cell to a metal surface using FRET. However, this requires high numerical aperture (NA) objective lens because axial confocal resolution must be smaller than the cell thickness. This requirement limits the field of view of the measurement specimen. In this study we provides a new method which can measure adhesion properties of endothelial cells even with a low NA objective lens by resolving two lifetime components in FLIM.

Photodetection of early cancer by laser-induced fluorescence of a tumor-selective dye: apparatus design and realization

Science.gov (United States)

Wagnieres, Georges A.; Depeursinge, Christian D.; Monnier, Philippe; Savary, Jean-Francois; Cornaz, Piet F.; Chatelain, Andre; van den Bergh, Hubert

1990-07-01

An apparatus is designed and realized to detect "early" cancer at the surface of the hollow organs in the human body by endoscopic means. The tumor is localized by the laser induced fluorescence of a dye (HPD) which concentrates selectively in the neoplastic tissue after intravenous injection. Fluorescence contrast between the tumor and its normal surroundings is enhanced by subtracting the background autofluorescence which occurs in both types of tissue. This is done by means of 2-color digital images manipulation in real-time. Preliminary clinical tests of the apparatus demonstrated the detection of carcinoma in situ in the esophagus.

Lie Group Analysis of the Photo-Induced Fluorescence of Drosophila Oogenesis with the Asymmetrically Localized Gurken Protein.

Directory of Open Access Journals (Sweden)

Jen-Cheng Wang

Full Text Available Lie group analysis of the photo-induced fluorescence of Drosophila oogenesis with the asymmetrically localized Gurken protein has been performed systematically to assess the roles of ligand-receptor complexes in follicle cells. The (2×2 matrix representations resulting from the polarized tissue spectra were employed to characterize the asymmetrical Gurken distributions. It was found that the fluorescence of the wild-type egg shows the Lie point symmetry X 23 at early stages of oogenesis. However, due to the morphogen regulation by intracellular proteins and extracellular proteins, the fluorescence of the embryogenesis with asymmetrically localized Gurken expansions exhibits specific symmetry features: Lie point symmetry Z 1 and Lie point symmetry X 1. The novel approach developed herein was successfully used to validate that the invariant-theoretical characterizations are consonant with the observed asymmetric fluctuations during early embryological development.

Experimental studies of the propagation of electrostatic ion perturbations by time-resolved laser-induced fluorescence

International Nuclear Information System (INIS)

Bachet, G.; Skiff, F.; Doveil, F.; Stern, R.A.

2001-01-01

Effects induced by the propagation of several kinds of electrostatic perturbation in a low-density collisionless argon plasma are observed with space, time, and velocity-resolved laser-induced fluorescence (LIF). The propagation of strong self-organized ion structures is observed and the associated electric field is determined. Snap shots of the ion phase space with a time resolution of 2 μs can be reconstructed from the experimental data. All the terms of the kinetic equation can also be determined from the data. A one-dimensional (1D) numerical simulation reproduces qualitatively the experimentally observed ion phase space behavior

UV laser-induced fluorescence spectroscopy and laser Doppler flowmetry in the diagnostics of alopecia

Science.gov (United States)

Skomorokha, Diana P.; Pigoreva, Yulia N.; Salmin, Vladimir V.

2016-04-01

Development of optical biopsy methods has a great interest for medical diagnostics. In clinical and experimental studies it is very important to analyze blood circulation quickly and accurately, thereby laser Doppler flowmetry (LDF) is widely used. UV laser-induced fluorescence spectroscopy (UV LIFS) is express highly sensitive and widely-spread method with no destructive impact, high excitation selectivity and the possibility to use in highly scattering media. The goal of this work was to assess a correlation of UV laser-induced fluorescence spectroscopy and laser Doppler flowmetry parameters, and a possibility to identify or to differentiate various types of pathological changes in tissues according to their autofluorescence spectra. Three groups of patients with diffuse (symptomatic) alopecia, androgenic alopecia, and focal alopecia have been tested. Each groups consisted of not less than 20 persons. The measurements have been done in the parietal and occipital regions of the sculls. We used the original automated spectrofluorimeter to record autofluorescence spectra, and standard laser Doppler flowmeter BLF-21 (Transonic Systems, Inc., USA) to analyze the basal levels of blood circulation. Our results show that UV LIFS accurately distinguishes the zones with different types of alopecia. We found high correlation of the basal levels of blood circulation and the integrated intensity of autofluorescence in the affected tissue.

Visualizing and quantifying dose distribution in a UV reactor using three-dimensional laser-induced fluorescence.

Science.gov (United States)

Gandhi, Varun N; Roberts, Philip J W; Kim, Jae-Hong

2012-12-18

Evaluating the performance of typical water treatment UV reactors is challenging due to the complexity in assessing spatial and temporal variation of UV fluence, resulting from highly unsteady, turbulent nature of flow and variation in UV intensity. In this study, three-dimensional laser-induced fluorescence (3DLIF) was applied to visualize and quantitatively analyze a lab-scale UV reactor consisting of one lamp sleeve placed perpendicular to flow. Mapping the spatial and temporal fluence delivery and MS2 inactivation revealed the highest local fluence in the wake zone due to longer residence time and higher UV exposure, while the lowest local fluence occurred in a region near the walls due to short-circuiting flow and lower UV fluence rate. Comparing the tracer based decomposition between hydrodynamics and IT revealed similar coherent structures showing the dependency of fluence delivery on the reactor flow. The location of tracer injection, varying the height and upstream distance from the lamp center, was found to significantly affect the UV fluence received by the tracer. A Lagrangian-based analysis was also employed to predict the fluence along specific paths of travel, which agreed with the experiments. The 3DLIF technique developed in this study provides new insight on dose delivery that fluctuates both spatially and temporally and is expected to aid design and optimization of UV reactors as well as validate computational fluid dynamics models that are widely used to simulate UV reactor performances.

Stress of formalin treatment in juvenile spring chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Salmo gairdneri)

Science.gov (United States)

Wedemeyer, Gary; Yasutake, W.T.

1973-01-01

The physiological stress of 200 ppm formalin treatments at 10 C is more severe in the juvenile steelhead trout (Salmo gairdneri) than in the spring chinook salmon (Oncorhynchus tshawytscha). In the steelhead, a marked hypochloremia follows a 1-hr treatment and recovery requires about 24 hr. During longer treatments, hypercholesterolemia together with reduced regulatory precision, hypercortisolemia, alkaline reserve depletion, and hypocapnia unaccompanied by a fall in blood pH occur — suggestive of compensated respiratory alkalosis. In the spring chinook, hypochloremia and reduced plasma cholesterol regulatory precision are the significant treatment side effects but recovery requires only a few hours.Formalin treatments also cause epithelial separation, hypertrophy, and necrosis in the gills of both fishes but again, consistent with the physiological dysfunctions, these are more severe in the steelhead.

Ultraviolet laser-induced fluorescence detection strategies in capillary electrophoresis: determination of naphthalene sulphonates in river water.

NARCIS (Netherlands)

Kok, S.J.; Isberg, I.C.K.; Gooijer, C.; Brinkman, U.A.T.; Velthorst, N.H.

1998-01-01

Various UV-laser-induced fluorescence detection strategies for capillary electrophoresis (CE) are compared, i.e. two UV-laser systems (a pulsed laser providing up to 25 mW of tunable emission, applied at 280, 290 and 325 nm, and a continuous wave (cw) laser providing up to 100 mW of 257 nm emission)

Ultratrace analysis of actinides via coprecipitation/laser-induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Miller, S.M.

1982-01-01

Actinides were selectively preconcentrated by coprecipitating each out of solution with a fluoride matrix and calcining each sample at 800 0 C. The fluorescence spectrum of each sample was recorded by illuminating the sample with laser light and detecting fluorescence with either a fluorescence/Raman spectrometer, an infrared spectrometer or in certain cases a filter fluorimeter. Three previously unobserved actinide spectra were recorded. Narrow lines at 546.9 nm, 564.6 nm, and 569.6 nm were found for CaF 2 :PuO 2++ at 10K. CaF 2 :Am + 3 displayed two broadband fluorescent peaks at 625 nm and 746 nm at room temperature and CaF 2 :Pu + 3 possessed a fluorescent peak at 1.22 microns at 10K. Energy transfer was observed in the form of Tb fluorescence quenching in TbF 3 :Pu + 3 when Pu was present in quantities of 10 ppM or more and in the form of Tb fluorescence enhancement in TbF 3 :Am + 3 when 1 ppM or more of Am was present. Careful sample preparation and the use of temporal as well as a spectral discrimination system extended the detection limit of U from 1 ml samples to the subfemtogram level. The fluorescence detection limits for Pu and Am were extended to 0.48 and 0.032 pg/ml. 39 figures, 9 tables

Dose-Response Analysis of RNA-Seq Profiles in Archival Formalin-Fixed Paraffin-Embedded (FFPE) Samples.

Science.gov (United States)

Use of archival resources has been limited to date by inconsistent methods for genomic profiling of degraded RNA from formalin-fixed paraffin-embedded (FFPE) samples. RNA-sequencing offers a promising way to address this problem. Here we evaluated transcriptomic dose responses us...

"Interaction of different doses of Aspartame with Morphine-induced antinociception in the presence of MK-801, a NMDA antagonist "

Directory of Open Access Journals (Sweden)

Abdollahi M

2002-07-01

Full Text Available This study was designed to investigate the relative role of sweetness and comparative effects of different taste sensation of the non - caloric sweetener , aspartame on pain and its interaction with MK - 80] as a non - selective MMDA antagonist by formalin - test in mice. The formalin - test was chosen because it measures the response to a long - lasting nociceptive stimulus and closely resembles to the clinical pain. Morphine induced a dose dependent antinociception in the early and late phases of formalin test. Twelve days pretreatment of animals by aspartame ( 0.08% , 0.16% , 0.32% significantly potentiated morphine - induced (1.5-9 mg/kg analgesia in the early phase but significantly antagonized its analgesic effect in the late phase, dose dependently. Aspartame (0.16% alone showed a reduction in pain response . Naloxone (0.4 mg/kg significantly antagonized the antinociceptive effect of morphine in the presence of aspartame (0-0.32% in the early phase. Increasing the dose of aspartame decreased effects of naloxone. MK-801 (0.1 mg/kg as an N- Methyl - D - Aspartate (NMDA antagonist significantly potentiated the effect of aspartame on morphine - induced antinociception in the early phase. In the late phase, naloxone (0.4 mg/kg increased pain response but MK- 801 (0.1 mg/kg induced anti-inflammatory effect significantly. Treatment of animals with MK- 801 alone, significantly induced analgesia in both phases of formalin - test. This effect was potentiated with aspartame dose - dependently. Possible interaction of aspartame with NMDA receptors and its role to facilitate endogenous opioid system are proposed mechanisms of aspartame in modulating morphine - induced antinociception. Furthermore, the resulting association between morphine and aspartame chronic consumption may be explained as an interactive action rather than simple dose combination of both drugs.

Thyroid iodine content measured by x-ray fluorescence in amiodarone-induced thyrotoxicosis: concise communication

International Nuclear Information System (INIS)

Leger, A.F.; Fragu, P.; Rougier, P.; Laurent, M.F.; Tubiana, M.; Savole, J.C.

1983-01-01

Iodine-induced thyrotoxicosis (IiT) is characterized by (a) a low radioiodine uptake, increased by exogenous TSH, and (b) a spontaneous evolution towards cure within a few months. An hypothetical pathogenesis of IiT is an initial inflation in the stores of thyroid hormones during iodine excess, followed by their sudden discharge into the circulation. Thyroid iodine content was measured by fluorescent scanning in 10 patients with amiodarone-induced thyrotoxicosis and in various control groups. Results were found to be high at the onset of the disease and to decrease during its course. The data agree with the hypothetical pathogenesis. Furthermore they may permit exclusion of a painless subacute thyroiditis, which is the main differential diagnosis of IiT

Transition probability of the 5971-A line in neutral uranium from collision-induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Gagne, J.M.; Mongeau, B.; Demers, Y.; Pianarosa, P.

1981-01-01

From collision-induced fluorescence spectroscopy measurements, we have determined the transition probability Aof the 5971-A transition in neutral uranium. Our value, A 5971 = (5.9 +- 1.8) x 10 5 sec -1 , is, within experimental error, in good agreement with the previous determination of Corliss, A 5971 = (7.3 +- 3.0) x 10 5 sec -1 [J. Res. Nat. Bur. Stand. Sect. A 80,1 (1976)

Assessing Photosynthesis by Fluorescence Imaging

Science.gov (United States)

Saura, Pedro; Quiles, Maria Jose

2011-01-01

This practical paper describes a novel fluorescence imaging experiment to study the three processes of photochemistry, fluorescence and thermal energy dissipation, which compete during the dissipation of excitation energy in photosynthesis. The technique represents a non-invasive tool for revealing and understanding the spatial heterogeneity in…

Development of the spectrometric imaging apparatus of laser induced fluorescence from plants and estimation of chlorophyll contents of rice leaves; Laser reiki keiko sokutei sochi no kaihatsu to inehanai no chlorophyll ganryo no suitei

Energy Technology Data Exchange (ETDEWEB)

Nakaya, K.; Shoji, K.; Hanyu, H.

1999-05-01

Photosynthetic activity of plants is an important factor to assess the micrometeorological effect of plant canopy or to estimate the influence of circumstances such as water stress. Light illumination induces fluorescence from a leaf or suspension of chloroplasts. The red chlorophyll fluorescence had been used to determine the process of the electron transportation in photosynthetic reaction. The fluorescence source other than chlorophyll is not announced sufficiently, but is supposed to be useful to determine the contents of the substance corresponding to physiological response of plants. We developed a fluorescence imaging apparatus to observe spectrum and distribution of laser induced fluorescence from a leaf. Pulsed UV-laser (Nd:YAG) induced blue-green fluorescence and red chlorophyll fluorescence from a green leaf. The pulse modulated measuring light and CCD with image-intensifier (ICCD) enable to detect the fluorescence from plants under illumination. The laser induced fluorescence (LIF) spectra were investigated to estimate the chlorophyll contents in leaves of rice. During the greening course of dark grown etiolated rice leaves, chlorophyll contents were determined using the extraction of leaves and steady state LIF spectra were measured. As a result, the ratio of fluorescent intensity between blue-green and red peaks (F460/F740 and F510/F740) decreased in proportion to alteration of chlorophyll contents respectively. These fluorescence intensity ratios perform more precise estimation of higher chlorophyll contents of leaves than reported red chlorophyll fluorescence intensity ratio (F690/E740). (author)

Terbium fluorescence as a sensitive, inexpensive probe for UV-induced damage in nucleic acids

International Nuclear Information System (INIS)

El-Yazbi, Amira F.; Loppnow, Glen R.

2013-01-01

Graphical abstract: -- Highlights: •Simple, inexpensive, mix-and-read assay for positive detection of DNA damage. •Recognition of undamaged DNA via hybridization to a hairpin probe. •Terbium(III) fluorescence reports the amount of damage by binding to ssDNA. •Tb/hairpin is a highly selective and sensitive fluorescent probe for DNA damage. -- Abstract: Much effort has been focused on developing methods for detecting damaged nucleic acids. However, almost all of the proposed methods consist of multi-step procedures, are limited, require expensive instruments, or suffer from a high level of interferences. In this paper, we present a novel simple, inexpensive, mix-and-read assay that is generally applicable to nucleic acid damage and uses the enhanced luminescence due to energy transfer from nucleic acids to terbium(III) (Tb 3+ ). Single-stranded oligonucleotides greatly enhance the Tb 3+ emission, but duplex DNA does not. With the use of a DNA hairpin probe complementary to the oligonucleotide of interest, the Tb 3+ /hairpin probe is applied to detect ultraviolet (UV)-induced DNA damage. The hairpin probe hybridizes only with the undamaged DNA. However, the damaged DNA remains single-stranded and enhances the intrinsic fluorescence of Tb 3+ , producing a detectable signal directly proportional to the amount of DNA damage. This allows the Tb 3+ /hairpin probe to be used for sensitive quantification of UV-induced DNA damage. The Tb 3+ /hairpin probe showed superior selectivity to DNA damage compared to conventional molecular beacons probes (MBs) and its sensitivity is more than 2.5 times higher than MBs with a limit of detection of 4.36 ± 1.2 nM. In addition, this probe is easier to synthesize and more than eight times cheaper than MBs, which makes its use recommended for high-throughput, quantitative analysis of DNA damage

Amine Analysis Using AlexaFluor 488 Succinimidyl Ester and Capillary Electrophoresis with Laser-Induced Fluorescence

Directory of Open Access Journals (Sweden)

Christian G. Kendall

2015-01-01

Full Text Available Fluorescent probes enable detection of otherwise nonfluorescent species via highly sensitive laser-induced fluorescence. Organic amines are predominantly nonfluorescent and are of analytical interest in agricultural and food science, biomedical applications, and biowarfare detection. Alexa Fluor 488 N-hydroxysuccinimidyl ester (AF488 NHS-ester is an amine-specific fluorescent probe. Here, we demonstrate low limit of detection of long-chain (C9 to C18 primary amines and optimize AF488 derivatization of long-chain primary amines. The reaction was found to be equally efficient in all solvents studied (dimethylsulfoxide, ethanol, and N,N-dimethylformamide. While an organic base (N,N-diisopropylethylamine is required to achieve efficient reaction between AF488 NHS-ester and organic amines with longer hydrophobic chains, high concentrations (>5 mM result in increased levels of ethylamine and propylamine in the blank. Optimal incubation times were found to be >12 hrs at room temperature. We present an initial capillary electrophoresis separation for analysis using a simple micellar electrokinetic chromatography (MEKC buffer consisting of 12 mM sodium dodecylsulfate (SDS and 5 mM carbonate, pH 10. Limits of detection using the optimized labeling conditions and these separation conditions were 5–17 nM. The method presented here represents a novel addition to the arsenal of fluorescent probes available for highly sensitive analysis of small organic molecules.

Direct visualization of secretion from single bovine adrenal chromaffin cells by laser-induced native fluorescence imaging microscopy

Energy Technology Data Exchange (ETDEWEB)

Tong, W.; Yeung, E.S. [Ames Laboratory---USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)

1998-03-01

Direct visualization of the secretion process of individual bovine adrenal chromaffin cells was achieved with laser-induced native fluorescence imaging microscopy. By monitoring the native fluorescence of catecholamines excited by the 275 nm laser line with an intensified charge-coupled-device (CCD) camera, we obtained good temporal and spatial resolution simultaneously without using additional fluorescent probes. Large variations were found among individual cells in terms of the amounts of catecholamines secreted and the rates of secretion. Different regions of a cell also behave differently during the secretion process. However, the degree of this local heterogeneity is smaller than in neurons and neuralgia. The influence of deep-ultraviolet (UV) laser excitation on cells is also discussed. This quantitative imaging technique provides a useful noninvasive approach for the study of dynamic cellular changes and the understanding of the molecular mechanisms of secretory processes. {copyright} {ital 1998} {ital Society for Applied Spectroscopy}

Complete solubilization of formalin-fixed, paraffin-embedded tissue may improve proteomic studies.

Science.gov (United States)

Shi, Shan-Rong; Taylor, Clive R; Fowler, Carol B; Mason, Jeffrey T

2013-04-01

Tissue-based proteomic approaches (tissue proteomics) are essential for discovering and evaluating biomarkers for personalized medicine. In any proteomics study, the most critical issue is sample extraction and preparation. This problem is especially difficult when recovering proteins from formalin-fixed, paraffin-embedded (FFPE) tissue sections. However, improving and standardizing protein extraction from FFPE tissue is a critical need because of the millions of archival FFPE tissues available in tissue banks worldwide. Recent progress in the application of heat-induced antigen retrieval principles for protein extraction from FFPE tissue has resulted in a number of published FFPE tissue proteomics studies. However, there is currently no consensus on the optimal protocol for protein extraction from FFPE tissue or accepted standards for quantitative evaluation of the extracts. Standardization is critical to ensure the accurate evaluation of FFPE protein extracts by proteomic methods such as reverse phase protein arrays, which is now in clinical use. In our view, complete solubilization of FFPE tissue samples is the best way to achieve the goal of standardizing the recovery of proteins from FFPE tissues. However, further studies are recommended to develop standardized protein extraction methods to ensure quantitative and qualitative reproducibility in the recovery of proteins from FFPE tissues. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of noble metal on automotive exhaust catalysts by radioisotope-induce x-ray fluorescence

International Nuclear Information System (INIS)

Elgart, M.F.

1976-01-01

A technique was developed for the in-situ analysis of noble metals deposited on monolithic automotive exhaust catalysts. This technique is based on radioisotope-induced x-ray fluorescence, and provides a detailed picture of the distribution of palladium and platinum on catalyst samples. The experimental results for the cross section of a monolithic exhaust catalyst, analyzed in increments of 0.2 cm 3 , are compared with analyses for palladium and platinum obtained by instrumental neutron activation analysis

Flame Front Detection Using Formaldehyde Laser Induced Fluorescence In Turbulent Lean Premixed Flames

Energy Technology Data Exchange (ETDEWEB)

Schenker, S.; Tylli, N.; Bombach, R.

2005-03-01

The present work aims at suggesting the excitation-detection scheme best suited for laser-induced fluorescence measurements of formaldehyde in turbulent lean premixed flames. In the literature, three different excitation schemes within the A{sup 1} X{sup 1} electronic transition have been suggested, with excitation into the 2{sup 1}{sub 0} 4{sup 1}{sub 0} , 4{sup 1}{sub 0} , and 4{sup 0}{sub 1} vibratoric bands, respectively. These excitation schemes were tested systematically and both advantages and disadvantages for each scheme are discussed. (author)

Investigation of archived formalin-fixed paraffin-embedded pancreatic tissue with whole-genome gene expression microarray

DEFF Research Database (Denmark)

Michelsen, Nete Vinstrup; Brusgaard, Klaus; Tan, Qihua

2011-01-01

The use of formalin-fixed, paraffin-embedded (FFPE) tissue overcomes the most prominent issues related to research on relatively rare diseases: limited sample size, availability of control tissue, and time frame. The use of FFPE pancreatic tissue in GEM may be especially challenging due to its very...

Quantified light-induced fluorescence, review of a diagnostic tool in prevention of oral disease

Science.gov (United States)

de Josselin de Jong, Elbert; Higham, Susan M.; Smith, Philip W.; van Daelen, Catherina J.; van der Veen, Monique H.

2009-05-01

Diagnostic methods for the use in preventive dentistry are being developed continuously. Few of these find their way into general practice. Although the general trend in medicine is to focus on disease prevention and early diagnostics, in dentistry this is still not the case. Nevertheless, in dental research some of these methods seem to be promising for near future use by the general dental professional. In this paper an overview is given of a method called quantitative light-induced fluorescence or (QLF) in which visible and harmless light excites the teeth in the patient's mouth to produce fluorescent images, which can be stored on disk and computer analyzed. White spots (early dental caries) are detected and quantified as well as bacterial metabolites on and in the teeth. An overview of research to validate the technique and modeling to further the understanding of the technique by Monte Carlo simulation is given and it is shown that the fluorescence phenomena can be described by the simulation model in a qualitative way. A model describing the visibility of red fluorescence from within the dental tissue is added, as this was still lacking in current literature. An overview is given of the clinical images made with the system and of the extensive research which has been done. The QLF™ technology has been shown to be of importance when used in clinical trials with respect to the testing of toothpastes and preventive treatments. It is expected that the QLF™ technology will soon find its way into the general dental practice.

Determination of nuclear spins of short-lived isotopes by laser induced fluorescence

International Nuclear Information System (INIS)

Buchinger, F.; Dabkiewicz, P.; Kremmling, H.; Kuehl, T.; Mueller, A.C.; Schuessler, H.A.

1980-01-01

The spins of several nuclear ground and isomeric states have been measured for a number of mercury isotopes. The fluorescent light from the 6s6p 3 P 1 state is observed at 2537 Angstroem after excitation with the frequency doubled output of a pulsed dye laser. Four different laser induced fluorescence techniques were tested for their applicability: double resonance, Hanle effect, time delayed integral Hanle beats, and time resolved quantum beats. The sensitivity and selectivity of these models are compared with emphasis on the determination of spins of nuclei far from beta-stability, where short half lives and low production yields restrict the number of available atoms. The experiments were carried out on-line with the ISOLDE isotope separator at CERN at densities as low as 10 6 atoms/cm 3 . Results for the very neutron deficient high spin mercury isomers with half lives of several seconds, but also for the ground states of the abundant low spin stable mercury isotopes, are given as examples. The test measurements determined the nuclear spins of the odd sup(185m-191m)Hg isomers to be I = 13/2. (orig.)

Reduced Fluorescent Protein Switching Fatigue by Binding-Induced Emissive State Stabilization

Directory of Open Access Journals (Sweden)

Thijs Roebroek

2017-09-01

Full Text Available Reversibly switchable fluorescent proteins (RSFPs enable advanced fluorescence imaging, though the performance of this imaging crucially depends on the properties of the labels. We report on the use of an existing small binding peptide, named Enhancer, to modulate the spectroscopic properties of the recently developed rsGreen series of RSFPs. Fusion constructs of Enhancer with rsGreen1 and rsGreenF revealed an increased molecular brightness and pH stability, although expression in living E. coli or HeLa cells resulted in a decrease of the overall emission. Surprisingly, Enhancer binding also increased off-switching speed and resistance to switching fatigue. Further investigation suggested that the RSFPs can interconvert between fast- and slow-switching emissive states, with the overall protein population gradually converting to the slow-switching state through irradiation. The Enhancer modulates the spectroscopic properties of both states, but also preferentially stabilizes the fast-switching state, supporting the increased fatigue resistance. This work demonstrates how the photo-physical properties of RSFPs can be influenced by their binding to other small proteins, which opens up new horizons for applications that may require such modulation. Furthermore, we provide new insights into the photoswitching kinetics that should be of general consideration when developing new RSFPs with improved or different photochromic properties.

Using violet laser-induced chlorophyll fluorescence emission spectra for crop yield assessment of cowpea (Vigna unguiculata (L) Walp) varieties

Science.gov (United States)

Anderson, Benjamin; Buah-Bassuah, Paul K.; Tetteh, Jonathan P.

2004-07-01

The use of violet laser-induced chlorophyll fluorescence (LICF) emission spectra to monitor the growth of five varieties of cowpea in the University of Cape Coast Botanical Garden is presented. Radiation from a continuous-wave violet laser diode emitting at 396 nm through a fibre is closely incident on in vivo leaves of cowpea to excite chlorophyll fluorescence, which is detected by an integrated spectrometer with CCD readout. The chlorophyll fluorescence spectra with peaks at 683 and 731 nm were used for growth monitoring of the cowpea plants over three weeks and analysed using Gaussian spectral functions with curve fitted parameters to determine the peak positions, area under the spectral curve and the intensity ratio F683/F731. The variation in the intensity ratio of the chlorophyll bands showed sensitive changes indicating the photosynthetic activity of the cowpea varieties. A discussion of the fluorescence result as compared to conventional assessment is presented with regard to discrimination between the cowpea varieties in terms of crop yield performance.

The motional stark effect with laser-induced fluorescence diagnostic

Science.gov (United States)

Foley, E. L.; Levinton, F. M.

2010-05-01

The motional Stark effect (MSE) diagnostic is the worldwide standard technique for internal magnetic field pitch angle measurements in magnetized plasmas. Traditionally, it is based on using polarimetry to measure the polarization direction of light emitted from a hydrogenic species in a neutral beam. As the beam passes through the magnetized plasma at a high velocity, in its rest frame it perceives a Lorentz electric field. This field causes the H-alpha emission to be split and polarized. A new technique under development adds laser-induced fluorescence (LIF) to a diagnostic neutral beam (DNB) for an MSE measurement that will enable radially resolved magnetic field magnitude as well as pitch angle measurements in even low-field (experiments. An MSE-LIF system will be installed on the National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory. It will enable reconstructions of the plasma pressure, q-profile and current as well as, in conjunction with the existing MSE system, measurements of radial electric fields.

Laser Induced Fluorescence Diagnostic for the Plasma Couette Experiment

Science.gov (United States)

Katz, Noam; Skiff, Fred; Collins, Cami; Weisberg, Dave; Wallace, John; Clark, Mike; Garot, Kristine; Forest, Cary

2010-11-01

The Plasma Couette Experiment (PCX) at U. Wisconsin-Madison consists of a rotating high-beta plasma and is well-suited to the study of flow-driven, astrophysically-relevant plasma phenomena. PCX confinement relies on alternating rings of 1kG permanent magnets and the rotation is driven by electrode rings, interspersed between the magnets, which provide an azimuthal ExB. I will discuss the development of a laser-induced fluorescence diagnostic (LIF) to characterize the ion distribution function of argon plasmas in PCX. The LIF system--which will be scanned radially--will be used to calibrate internal Mach probes, as well as to measure the time-resolved velocity profile, ion temperature and density non-perturbatively. These diagnostics will be applied to study the magneto-rotational instability in a plasma, as well as the buoyancy instability thought to be involved in producing the solar magnetic field. This work is supported by NSF and DOE.

Distinguishing nitrogen fertilization levels in field corn (Zea mays L.) with actively induced fluorescence and passive reflectance measurements

International Nuclear Information System (INIS)

McMurtrey, J.E. III; Chappelle, E.W.; Kim, M.S.; Meisinger, J.J.; Corp, L.A

1994-01-01

Laser-induced fluorescence (LIF) is an active sensing technique capable of capturing immediate and specific indications of changes in plant physiology and metabolism as they relate to the concentration and photosynthetic activity of the plant pigments. Reflectance is a passive sensing technique that can capture differences in the concentration of the primary plant pigments. Fluorescence and reflectance were compared for their ability to measure levels of plant stress that are of agronomic importance in corn (Zea mays L.) crops. Laboratory LIF and reflectance spectra were made on excised leaves from field grown corn. Changes in the visible region of the spectrum were compared between groups of plants fertilized with seven different levels of nitrogen (N) fertilization. A pulsed nitrogen laser emitting photons at a wavelength of 337 nm was used as a fluorescence excitation source. Differences in maximum intensity of fluorescence occurred at 440 nm, 525 nm, 685 nm, and 740 nm. Significant separations were found between levels of N fertilization at several LIF wavelength ratios. Several reflectance algorithms also produced significant separations between certain levels of N fertilization

Radiation-induced polymerization monitored in situ by time-resolved fluorescence of probe molecules in methyl methacrylate

International Nuclear Information System (INIS)

Frahn, Mark S.; Abellon, Ruben D.; Luthjens, Leonard H.; Vermeulen, Martien J.W.; Warman, John M.

2003-01-01

A technique is presented for monitoring radiation-induced polymerizations in situ based on the measurement of the fluorescence lifetime of molecular probes dissolved in the polymerizing medium. This method is illustrated with results on methyl methacrylate (MMA) using two fluorogenic probe molecules; N-(2-anthracene)methacrylamide (AnMA) and maleimido-fluoroprobe (MFP), a molecule which has a highly dipolar excited state

Applicability of UV laser-induced solid-state fluorescence spectroscopy for characterization of solid dosage forms.

Science.gov (United States)

Woltmann, Eva; Meyer, Hans; Weigel, Diana; Pritzke, Heinz; Posch, Tjorben N; Kler, Pablo A; Schürmann, Klaus; Roscher, Jörg; Huhn, Carolin

2014-10-01

High production output of solid pharmaceutical formulations requires fast methods to ensure their quality. Likewise, fast analytical procedures are required in forensic sciences, for example at customs, to substantiate an initial suspicion. We here present the design and the optimization of an instrumental setup for rapid and non-invasive characterization of tablets by laser-induced fluorescence spectroscopy (with a UV-laser (λ ex = 266 nm) as excitation source) in reflection geometry. The setup was first validated with regard to repeatability, bleaching phenomena, and sensitivity. The effect on the spectra by the physical and chemical properties of the samples, e.g. their hardness, homogeneity, chemical composition, and granule grain size of the uncompressed material, using a series of tablets, manufactured in accordance with design of experiments, was investigated. Investigation of tablets with regard to homogeneity, especially, is extremely important in pharmaceutical production processes. We demonstrate that multiplicative scatter correction is an appropriate tool for data preprocessing of fluorescence spectra. Tablets with different physical and chemical characteristics can be discriminated well from their fluorescence spectra by subjecting the results to principal component analysis.

Acute toxicity and histopathology in ornamental fish amazon bluespotted corydora (Corydoras melanistius exposed to formalin

Directory of Open Access Journals (Sweden)

Rudã F.B. Santos

2012-12-01

Full Text Available The objective of this work was to evaluate the acute toxicity of formalin and histopathological effects on the Amazon ornamental fish, bluespotted coridora (Corydoras melanistius. A randomized design was used, with ten concentrations of formalin (40% (0, 3, 6, 12, 25, 50, 100, 150, 200 and 250mg.L-1 with four replicates and five fish per container (3L in static system for 96 hours. The moribund fish were killed and fixed in 10% formalin to proceed the histopathological analysis of gill, liver and kidney. At the end of this experiment the following mortality rates (% were obtained in increasing order of exposure: 0, 0, 0, 0, 0, 65, 85, 100, 100 and 100%. The lethal concentration 50% (LC50-96h (I estimated was 50.76 mg.L-1 with regression of y = 0.51x, and r² = 0.80. Further, in higher concentrations morphological changes as gill hyperplasia, with filling of interlamellar spaces, disorganization of liver arrangement, and necrosis in kidney were observed. In this study, the formalin can be considered slightly toxic to bluespotted corydora, and cause morphological changes when exposed to high concentrations. The use of formalin to treat of ornamental fish in the inner river of capture with wrong concentration can provoke negative environmental and biological effects.O objetivo do trabalho foi determinar a toxicidade aguda de formalina e os efeitos histopatológicos para o peixe ornamental amazônico corredora bicuda (Corydora melanistius. Foi utilizado um delineamento inteiramente casualizado; com dez concentrações de formalina 40% (0, 3, 6, 12, 25, 50, 100, 150, 200 e 250mg.L-1, com quatro repetições e cinco peixes por recipiente de água (3 L em sistema estático durante 96 horas. Os peixes moribundos foram mortos e fixados em formol 10% procedendo à análise histopatológica das brânquias e do fígado. Ao final desse experimento, obtiveram-se as seguintes taxas de mortalidades em ordem crescente de exposição (%: 0, 0, 0, 0, 0, 65, 85

Comparing the proteome of snap frozen, RNAlater preserved, and formalin-fixed paraffin-embedded human tissue samples

DEFF Research Database (Denmark)

Bennike, Tue Bjerg; Kastaniegaard, Kenneth; Padurariu, Simona

2016-01-01

Large biobanks exist worldwide containing formalin-fixed, paraffin-embedded samples and samples stored in RNAlater. However, the impact of tissue preservation on the result of a quantative proteome analysis remains poorly described.Human colon mucosal biopsies were extracted from the sigmoideum...

Conformational fluctuation dynamics of domain I of human serum albumin in the course of chemically and thermally induced unfolding using fluorescence correlation spectroscopy.

Science.gov (United States)

Yadav, Rajeev; Sengupta, Bhaswati; Sen, Pratik

2014-05-22

The present study elucidates the involvement of conformational fluctuation dynamics during chemically and thermally induced unfolding of human serum albumin (HSA) by fluorescence correlation spectroscopic (FCS) study, time-resolved fluorescence measurements, and circular dichroism (CD) spectroscopic methods. Two fluorescent probes, tetramethylrhodamine-5-maleimide (TMR) and N-(7-dimethylamino-4-methylcoumarin-3-yl) iodoacetamide (DACIA) were used to selectively label the domain I of HSA through the reaction with cys-34 for these studies. The guanidine hydrochloride (GnHCl) induced global structural change of HSA is monitored through its hydrodynamic radius (r(H)) and CD response, which is found to be two step in nature. In FCS experiment, along with the diffusion time component we have observed an exponential relaxation time component (τ(R)) that has been ascribed to the concerted chain dynamics of HSA. Unlike in the global structural change, we found that the τ(R) value changes in a different manner in the course of the unfolding. The dependence of τ(R) on the concentration of GnHCl was best fitted with a four state model, indicating the involvement of two intermediate states during the unfolding process, which were not observed through the CD response and r(H) data. The fluorescence lifetime measurement also supports our observation of intermediate states during the unfolding of HSA. However, no such intermediate states were observed during thermally induced unfolding of HSA.

A preparation of homogeneous distribution of palladium nanoparticle on poly (acrylic acid)-functionalized graphene oxide modified electrode for formalin oxidation

International Nuclear Information System (INIS)

Kongkaew, Supatinee; Kanatharana, Proespichaya; Thavarungkul, Panote; Limbut, Warakorn

2017-01-01

An excellent electrocatalytic activity, repeatability and stability of electrochemical sensor for formalin detection was fabricated based on a homogeneous distribution of ellipsoidal palladium nanoparticle (PdNPs) on poly (acrylic acid)-functionalized graphene oxide (PAA-GO) modified on a glassy carbon electrode (GCE) (PdNPs-PAA-GO/GCE) with incorporated flow injection amperometry (FI-Amp). Homogeneous distribution of ellipsoidal palladium nanoparticles (PdNPs) were dispersed on PAA-GO via an electroless deposition method. The surface morphology and electrochemical behavior of the PdNPs-PAA-GO/GCE were characterized by transmission electron microscopy, fourier transform infrared spectroscopy, cyclic voltammetry and amperometry. The PdNPs-PAA-GO/GCE exhibited excellent electrocatalytic activity toward formalin oxidation. Then this modified electrode was incorporated with FI-Amp for formalin sensor development. In order to obtain good analytical performances, many parameters such as the amount of PdNPs-PAA-GO, applied potential, flow rate and sample volume were optimized. Under optimal conditions, this sensor provided a wide linear range, 50-50,000 μmol L −1 , with high sensitivity (320 μA mmol L −1 cm −2 ). The limit of detection and limit of quantitation were 16 μmol L −1 and 53 μmol L −1 , respectively. This proposed sensor exhibited good repeatability (RSD < 3.5%), excellence stability (RSD = 1.5%, n = 500) and high sample throughput (60 samples h −1 ). This method was applied to the determination of formalin in soaked fresh food samples with satisfactory recovery.

Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

Directory of Open Access Journals (Sweden)

In-Suck Baek

2014-11-01

Full Text Available A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA was applied to the fluorescence emission spectra of all regions at 410 nm excitation to determine the emission wavelengths for defect detection. The major emission wavelengths were 688 nm and 506 nm for the detection. Fluorescence images combined with the determined emission wavebands demonstrated the feasibility of detecting defective cherry tomatoes with >98% accuracy. Multi-spectral fluorescence imaging has potential utility in non-destructive quality sorting of cherry tomatoes.

Time resolved laser induced fluorescence on argon intermediate pressure microwave discharges : measuring the depopulation rates of the 4p and 5p excited levels as induced by electron and atom collisions

NARCIS (Netherlands)

Palomares Linares, J.M.; Graef, W.A.A.D.; Hubner, S.; Mullen, van der J.J.A.M.

2013-01-01

The reaction kinetics in the excitation space of Ar is explored by means of Laser Induced Fluorescence (LIF) experiments using the combination of high rep-rate YAG–Dye laser systems with a well defined and easily controllable surfatron induced plasma setup. The high rep-rate favors the photon

A chemometric analysis of ligand-induced changes in intrinsic fluorescence of folate binding protein indicates a link between altered conformational structure and physico-chemical characteristics

DEFF Research Database (Denmark)

Bruun, Susanne W; Holm, Jan; Hansen, Steen Ingemann

2009-01-01

Ligand binding alters the conformational structure and physico-chemical characteristics of bovine folate binding protein (FBP). For the purpose of achieving further information we analyzed ligand (folate and methotrexate)-induced changes in the fluorescence landscape of FBP. Fluorescence excitation...... of folate accords fairly well with the disappearance of strongly hydrophobic tryptophan residues from the solvent-exposed surface of FBP. The PARAFAC has thus proven useful to establish a hitherto unexplained link between parallel changes in conformational structure and physico-chemical characteristics...... of FBP induced by folate binding. Parameters for ligand binding derived from PARAFAC analysis of the fluorescence data were qualitatively and quantitatively similar to those obtained from binding of radiofolate to FBP. Herein, methotrexate exhibited a higher affinity for FBP than in competition...

New insights into heat induced structural changes of pectin methylesterase on fluorescence spectroscopy and molecular modeling basis

Science.gov (United States)

Nistor, Oana Viorela; Stănciuc, Nicoleta; Aprodu, Iuliana; Botez, Elisabeta

2014-07-01

Heat-induced structural changes of Aspergillus oryzae pectin methylesterase (PME) were studied by means of fluorescence spectroscopy and molecular modeling, whereas the functional enzyme stability was monitored by inactivation studies. The fluorescence spectroscopy experiments were performed at two pH value (4.5 and 7.0). At both pH values, the phase diagrams were linear, indicating the presence of two molecular species induced by thermal treatment. A red shift of 7 nm was observed at neutral pH by increasing temperature up to 60 °C, followed by a blue shift of 4 nm at 70 °C, suggesting significant conformational rearrangements. The quenching experiments using acrylamide and iodide demonstrate a more flexible conformation of enzyme with increasing temperature, especially at neutral pH. The experimental results were complemented with atomic level observations on PME model behavior after performing molecular dynamics simulations at different temperatures. The inactivation kinetics of PME in buffer solutions was fitted using a first-order kinetics model, resulting in activation energy of 241.4 ± 7.51 kJ mol-1.

Establishing a cellular FRET-based fluorescence plate reader assay to monitor proNGF-induced cross-linking of sortilin and the neurotrophin receptor p75(NTR)

DEFF Research Database (Denmark)

Skeldal, Sune; Kjaergaard, Maj M; Alwasel, Saleh

2015-01-01

the vps10p domain receptor sortilin and the neurotrophin receptor p75(NTR). However, proNGF-induced receptor complex formation has been difficult to directly assess other than by western blotting. We here describe a fluorescence resonance energy transfer (FRET) based fluorescence plate reader assay...

Morphological and chemical information in fresh and vitrified ovarian tissues revealed by X-ray Microscopy and Fluorescence: observational study

Science.gov (United States)

Pascolo, L.; Venturin, I.; Gianoncelli, A.; Salomé, M.; Altissimo, M.; Bedolla, D. E.; Giolo, E.; Martinelli, M.; Luppi, S.; Romano, F.; Zweyer, M.; Ricci, G.

2018-06-01

Many clinical circumstances impose the necessity of collection and prolonged storage of gametes and/or ovarian tissue in order to preserve the reproduction potential of subjects. This is particularly appropriate in the case of young women and pre-pubertal girls undergoing chemotherapeutic treatments. The success of later assisted fertilization will depend on the suitable cooling protocols minimizing cryo-damages and preserving their biological function. The freeze-thaw processes of cryopreservation may induce, in fact, morphological and structural damages of oocytes and tissue mainly due to the formation of intracellular ice and to the toxicity of cryoprotectant. The most used cryo-protocol is the slow freezing procedure, but recently many authors have proposed vitrification as an alternative, because of its simplicity. The damage extent and the quality of follicles after cryopreservation are usually evaluated morphologically by conventional histological procedures, light and electron microscopy. Our laboratory, to further improve the evaluation and to better investigate damages, is adopting a combination of Synchrotron soft X-ray Microscopy (at TwinMic – Elettra) and XRF at different incident energies (at TwinMic – Elettra and ID21 – ESRF). X-ray techniques were performed on histological sections at micro and sub-micron resolution. Phase contrast and absorption images revealed changes in the compactness of the tissues, as well as cellular abnormalities revealed at sub-micrometric resolution. The distributions of the elements detected at 7.3 and 1.5 keV were compared and particularly Cl resulted to be indicative of follicle integrity. The results demonstrate the utility and the potential of X-ray microscopy and fluorescence in this research field.

The effect of microinjection of dimethyl sulfoxide into the rostral ventromedial medulla on swim stress-induced analgesia

Directory of Open Access Journals (Sweden)

S. Nazemi

2018-02-01

Full Text Available Background: Dimethyl sulfoxide (DMSO is an important solvent for compounds that used in pain research. Rostral ventromedial medulla (RVM plays an important role in modulating nociception and stress-induced analgesia (SIA. Objective: The aim of this study was to investigate the effect of DMSO administration into the RVM on SIA by using formalin test. Methods: This experimental study was conducted on 27 Wistar male rats (200±30 gr were randomly assigned to control, stress and stress+DMSO groups. Animals were placed in a water reservoir (20±1°C for 3 minutes to induce forced swimming stress. Stereotaxic surgery was performed to microinjection of DMSO (0.5μl, 100% into RVM. The pain behavior score was evaluated by subcutaneous injection of formalin 2% in the dorsal plantar region of hid paw. Findings: The pain score of phase 1, interphase and phase 2 of formalin test in swim stress group decreased significantly in comparison to control group (P<0.001, P< 0.05, P<0.001 respectively. In addition, the pain score of three phase of formalin test after DMSO injection in swim stress group decreased significantly in comparison to control and stress group (P<0.001, P<0.05 respectively. Conclusion: Also microinjections of DMSO into the RVM potentiate the swim stress analgesia. According to the analgesic effects of dimethyl sulfoxide, as well as its ability to potentiate stressinduced analgesia, DMSO should be used with caution as a solvent in pain studies. Conclusion: Force swim stress induces analgesia in, and microinjections of DMSO into the RVM potentiate the swim stress analgesia. According to the analgesic effects of DMSO, as well as its ability to potentiate stress-induced analgesia, it should be used with caution as solvent in pain studies.

[Effects of redox state of disulfide bonds on the intrinsic fluorescence and denaturation of Trx-fused gibberellin-induced cysteine-rich protein from Gymnadnia conopsea].

Science.gov (United States)

Zhang, Teng; Feng, Juan; Li, Yang; Chen, Rui; Tang, Li-Xia; Pang, Xiao-Feng; Ren, Zheng-Long

2010-02-01

In the present paper, thioredoxin-fused gibberellin-induced cysteine-rich protein from Gymnadnia conopsea, desigated as Trx-GcGASA and expressed prokaryotically, was purified and identified by using Ni(2+) -NTA affinity chromatography column and SDS-PAGE, and then its intrinsic fluorescence was investigated in the absence and presence of dithiothreitol (DTT), oxidized glutathione (GSSG), peroxide and guanidine hydrochloride (GdnHCl) by means of steady-state fluorescence spectroscopic methods. It was found that (1) at the neutral pH Trx-GcGASA had maximum fluorescence emission at 305 nm following excitation at different wavelengths varying from 250 to 280 nm, which was ascribed to the fluorescence emission from tyrosine residues. (2) The reduction of disulphide bonds lead to the changes in the relative fluorescence intensity between tyrosine and tryptophan residues from 0.7 to 1.8. (3) Both Tyr and Trp residues underwent 12%-21% decrease in fluorescence intensity with the addition of 0.5 mmol x L(-1) GSSG or 5 mmol x L(-1) peroxide. The latter was roughly consistent with the antioxidative activity reported in vivo. (4) No matter whether 1 mmol x L(-1) DTT was absent or present, the fusion protein could not be fully unfolded with lambda(max) Trx-GcGASA experienced GdnHCl-induced denaturation process, and the unfolding equilibrium curve could be well fitted by using two-state model, giving the Gibbs free energy change (deltaG) of 3.7 kJ x mol(-1). However, it was not the case for reduced Trx-GcGASA protein. The aforementioned experimental results will not only provide some guides to investigate the effects of fusion partner Trx on the unfolding thermodynamics, kinetics and refolding process of Trx-GcGASA, but also will be useful for further studies on the strucuture of GA-induced cysteine-rich protein with the help of spectroscopic methods.

Fluorescence and phosphorescence of rutin

Energy Technology Data Exchange (ETDEWEB)

Bondarev, Stanislav L., E-mail: bondarev@imaph.bas-net.by [Minsk State Higher Radioengineering College, 220005 Minsk (Belarus); Knyukshto, Valeri N. [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 220072 Minsk (Belarus)

2013-10-15

Rutin is one of the most promising flavonoid from a pharmacological and biochemical point of view. Here we have explored its spectroscopic and photophysical properties at room temperature and 77 K using steady-state absorption-luminescence methods and pulse spectroscopy equipment. By excitation into the absorption band 1 of rutin in methanol at room temperature the normal Stokes' shifted fluorescence with a maximum at 415 nm and quantum yield of 2×10{sup −4} was revealed. However, by excitation into the bands 2 and 3 any emission wasn’t observed. At 77 K in ethanol glass we have observed fluorescence at 410 nm and phosphorescence at 540 nm for the first time. As a result the adequate energetic scheme including the lowest electronic excited singlet at 26000 cm{sup −1} and triplet at 19600 cm{sup −1} states was proposed. -- Highlights: • Rutin fluorescence and phosphorescence at 77 K were revealed for the first time. • Room temperature fluorescence is determined by maximum at 415 nm and yield of 2×10{sup −4}. • Violation of Vavilov–Kasha rule by excitation into the absorption bands 2 and 3. • Fluorescence and phosphorescence in rutin are caused by the allowed π, π{sup (⁎)} transitions.

Direct measurements of neutral density depletion by two-photon absorption laser-induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Aanesland, A.; Liard, L.; Leray, G.; Jolly, J.; Chabert, P.

2007-01-01

The ground state density of xenon atoms has been measured by spatially resolved laser-induced fluorescence spectroscopy with two-photon excitation in the diffusion chamber of a magnetized Helicon plasma. This technique allows the authors to directly measure the relative variations of the xenon atom density without any assumptions. A significant neutral gas density depletion was measured in the core of the magnetized plasma, in agreement with previous theoretical and experimental works. It was also found that the neutral gas density was depleted near the radial walls

Differentiation of Induced Pluripotent Stem Cells to Lentoid Bodies Expressing a Lens Cell-Specific Fluorescent Reporter.

Directory of Open Access Journals (Sweden)

Taruna Anand

Full Text Available Curative approaches for eye cataracts and other eye abnormalities, such as myopia and hyperopia currently suffer from a lack of appropriate models. Here, we present a new approach for in vitro growth of lentoid bodies from induced pluripotent stem (iPS cells as a tool for ophthalmological research. We generated a transgenic mouse line with lens-specific expression of a fluorescent reporter driven by the alphaA crystallin promoter. Fetal fibroblasts were isolated from transgenic fetuses, reprogrammed to iPS cells, and differentiated to lentoid bodies exploiting the specific fluorescence of the lens cell-specific reporter. The employment of cell type-specific reporters for establishing and optimizing differentiation in vitro seems to be an efficient and generally applicable approach for developing differentiation protocols for desired cell populations.

Synthesis and bioimaging of biodegradable red fluorescent organic nanoparticles with aggregation-induced emission characteristics.

Science.gov (United States)

Xu, Dazhuang; Zou, Hui; Liu, Meiying; Tian, Jianwen; Huang, Hongye; Wan, Qing; Dai, Yanfeng; Wen, Yuanqing; Zhang, Xiaoyong; Wei, Yen

2017-12-15

Fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) features have recently emerged as promising fluorescent probes for biomedical applications owing to their excellent optical properties, designability and biocompatibility. Significant progress has been made recently for synthesis and biomedical applications of these AIE-active FONs. However, only very limited reports have demonstrated the fabrication of biodegradable AIE-active FONs with red fluorescence emission. In this study, a novel strategy has been developed for the preparation of biodegradable AIE-active polyurethanes (PUs) through a two-step polymerization, in which the diisocyanate-terminated polyethylene glycol (NCO-PEG-NCO) was synthesized and subsequently conjugated with diamine-containing AIE dye (NH 2 -Phe-NH 2 ). The successful synthesis of AIE-active Phe-PEG 2000 PUs is evidenced by a series of characterization techniques. Because of the formation of AIE-active amphiphilic PUs, the final copolymers can self-assemble into spherical nanoparticles, which exhibit strong luminescence and high water dispersion. The biological evaluation results suggest that the AIE-active Phe-PEG 2000 FONs possess low toxicity and desirable cell permeability. Therefore, we anticipate that these AIE-active FONs with biodegradable potential will trigger much research enthusiasm and effort toward the creation of new AIE-active materials with improved properties for various biomedical applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Effective scheme of photolysis of GFP in live cell as revealed with confocal fluorescence microscopy

Science.gov (United States)

Glazachev, Yu I.; Orlova, D. Y.; Řezníčková, P.; Bártová, E.

2018-05-01

We proposed an effective kinetics scheme of photolysis of green fluorescent protein (GFP) observed in live cells with a commercial confocal fluorescence microscope. We investigated the photolysis of GFP-tagged heterochromatin protein, HP1β-GFP, in live nucleus with the pulse position modulation approach, which has several advantages over the classical pump-and-probe method. At the basis of the proposed scheme lies a process of photoswitching from the native fluorescence state to the intermediate fluorescence state, which has a lower fluorescence yield and recovers back to native state in the dark. This kinetics scheme includes four effective parameters (photoswitching, reverse switching, photodegradation rate constants, and relative brightness of the intermediate state) and covers the time scale from dozens of milliseconds to minutes of the experimental fluorescence kinetics. Additionally, the applicability of the scheme was demonstrated in the cases of continuous irradiation and the classical pump-and-probe approach using numerical calculations and analytical solutions. An interesting finding of experimental data analysis was that the overall photodegradation of GFP proceeds dominantly from the intermediate state, and demonstrated approximately the second-order reaction versus irradiation power. As a practical example, the proposed scheme elucidates the artifacts of fluorescence recovery after the photobleaching method, and allows us to propose some suggestions on how to diminish them.

Formalin fixation increases deamination mutation signature but should not lead to false positive mutations in clinical practice.

Directory of Open Access Journals (Sweden)

Leah M Prentice

Full Text Available Genomic analysis of cancer tissues is an essential aspect of personalized oncology treatment. Though it has been suggested that formalin fixation of patient tissues may be suboptimal for molecular studies, this tissue processing approach remains the industry standard. Therefore clinical molecular laboratories must be able to work with formalin fixed, paraffin embedded (FFPE material. This study examines the effects of pre-analytic variables introduced by routine pathology processing on specimens used for clinical reports produced by next-generation sequencing technology. Tissue resected from three colorectal cancer patients was subjected to 2, 15, 24, and 48 hour fixation times in neutral buffered formalin. DNA was extracted from all tissues twice, once with uracil-N-glycosylase (UNG treatment to counter deamination effects, and once without. Of note, deamination events at methylated cytosine, as found at CpG sites, remains unaffected by UNG. After extraction a two-step PCR targeted sequencing method was performed using the Illumina MiSeq and the data was analyzed via a custom-built bioinformatics pipeline, including filtration of reads with mapping quality T/A mutations that is not represented in DNA treated with UNG. This suggests these errors may be due to deamination events triggered by a longer fixation time. However the allelic frequency of these events remained below the limit of detection for reportable mutations in this assay (<2%. We do however recommend that suspected intratumoral heterogeneity events be verified by re-sequencing the same FFPE block.

Detection of African swine fever virus from formalin fixed and non-fixed tissues by polymerase chain reaction

Directory of Open Access Journals (Sweden)

P. D. Luka

2014-10-01

Full Text Available Aim: Formalin fixing and paraffin embedding of tissue samples is one of the techniques for preserving the structural integrity of cells for a very long time. However, extraction and analysis of genomic material from formalin fixed tissue (FFT remains a challenge despite numerous attempts to develop a more effective method. The success of polymerase chain reaction (PCR depends on the quality of DNA extract. Materials and Methods: Here we assessed the conventional method of DNA extraction from FFT for African swine fever virus (ASFV detection. The modified conventional method gave a higher quality DNA when compared with commercially available DNA extraction kits (QIAamp® DNA Mini Kit, DNeasy® Blood and Tissue Kit, and ZR Genomic DNA™ Tissue MiniPrep. Results: An average A260/A280 DNA purity of 0.86-1.68 and 3.22-5.32 μg DNA/mg for formalin fixed and non-fixed tissues, respectively using a conventional method. In a reproducible and three times repeat PCR, the ASFV DNA expected product size of 278 bp was obtained from the DNA extract of the conventional method but not from the DNA extract of the commercial kits. Conclusion: The present study has demonstrated that the conventional method extracts ASFV genome better than commercial kit. In summary, the commercial kit extraction appeared not suitable to purify ASFV DNA from FFT. We, therefore, recommend that the use of the conventional method be considered for African swine fever DNA extraction from FFT.

Preparation of tissue samples for X-ray fluorescence microscopy

International Nuclear Information System (INIS)

Chwiej, Joanna; Szczerbowska-Boruchowska, Magdalena; Lankosz, Marek; Wojcik, Slawomir; Falkenberg, Gerald; Stegowski, Zdzislaw; Setkowicz, Zuzanna

2005-01-01

As is well-known, trace elements, especially metals, play an important role in the pathogenesis of many disorders. The topographic and quantitative elemental analysis of pathologically changed tissues may shed some new light on processes leading to the degeneration of cells in the case of selected diseases. An ideal and powerful tool for such purpose is the Synchrotron Microbeam X-ray Fluorescence technique. It enables the carrying out of investigations of the elemental composition of tissues even at the single cell level. The tissue samples for histopathological investigations are routinely fixed and embedded in paraffin. The authors try to verify the usefulness of such prepared tissue sections for elemental analysis with the use of X-ray fluorescence microscopy. Studies were performed on rat brain samples. Changes in elemental composition caused by fixation in formalin or paraformaldehyde and embedding in paraffin were examined. Measurements were carried out at the bending magnet beamline L of the Hamburger Synchrotronstrahlungslabor HASYLAB in Hamburg. The decrease in mass per unit area of K, Br and the increase in P, S, Fe, Cu and Zn in the tissue were observed as a result of the fixation. For the samples embedded in paraffin, a lower level of most elements was observed. Additionally, for these samples, changes in the composition of some elements were not uniform for different analyzed areas of rat brain

Preparation of tissue samples for X-ray fluorescence microscopy

Energy Technology Data Exchange (ETDEWEB)

Chwiej, Joanna [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland)]. E-mail: jchwiej@novell.ftj.agh.edu.pl; Szczerbowska-Boruchowska, Magdalena [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Lankosz, Marek [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Wojcik, Slawomir [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Falkenberg, Gerald [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron, Notkestr. 85, Hamburg (Germany); Stegowski, Zdzislaw [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Setkowicz, Zuzanna [Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060 Cracow (Poland)

2005-12-15

As is well-known, trace elements, especially metals, play an important role in the pathogenesis of many disorders. The topographic and quantitative elemental analysis of pathologically changed tissues may shed some new light on processes leading to the degeneration of cells in the case of selected diseases. An ideal and powerful tool for such purpose is the Synchrotron Microbeam X-ray Fluorescence technique. It enables the carrying out of investigations of the elemental composition of tissues even at the single cell level. The tissue samples for histopathological investigations are routinely fixed and embedded in paraffin. The authors try to verify the usefulness of such prepared tissue sections for elemental analysis with the use of X-ray fluorescence microscopy. Studies were performed on rat brain samples. Changes in elemental composition caused by fixation in formalin or paraformaldehyde and embedding in paraffin were examined. Measurements were carried out at the bending magnet beamline L of the Hamburger Synchrotronstrahlungslabor HASYLAB in Hamburg. The decrease in mass per unit area of K, Br and the increase in P, S, Fe, Cu and Zn in the tissue were observed as a result of the fixation. For the samples embedded in paraffin, a lower level of most elements was observed. Additionally, for these samples, changes in the composition of some elements were not uniform for different analyzed areas of rat brain.

Design and development of a LabVIEW-based LED-induced fluorescence spectroscopy system with applications in non-destructive quality assessment of agricultural products

International Nuclear Information System (INIS)

Abbasi, Hamed; Nazeri, Majid; Mireei, Seyed Ahmad

2016-01-01

Over the past several years, the demand for high quality agricultural products has been remarkably increased. Thus, it is important to use non-destructive methods for product quality monitoring. LED-induced fluorescence spectroscopy has proved its potential for nondestructive detection of some defects in agricultural products, such as tissue browning and bruising. Due to such defects, changes in the polyphenol and chlorophyll contents occur which can be considered as the visible marks of decreasing fruit quality. In the present work, a fluorescence spectrometer (spectrofluorometer) controlled by LabVIEW software was designed and developed. In this spectrometer, a consumer-grade webcam was used as an imaging sensor. The spectrometer was able to measure the fluorescence spectra directly from the fruit and vegetable surface in the desired regions. To do so, the spectrometer was equipped with a suitable fiber-optic probe. The hardware solution was based on data acquisition working on the USB platform and controlled by the application running on the PC. In this system, light emitting diodes with different wavelengths were used as the excitation sources for inducing fluorescence spectra of some famous fruits and vegetables. (paper)

Peroxy Radical Measurements via Laser Induced Fluorescence

Science.gov (United States)

Trawny, Katrin; Tatum Ernest, Cheryl; Novelli, Anna; Elste, Thomas; Plaß-Dülmer, Christian; Rudolf, Markus; Martinez, Monica; Harder, Hartwig; Lelieveld, Jos

2013-04-01

We present a newly built Laser Induced Fluorescence (LIF) system to measure the sum of all peroxy radicals (RO2) utilizing chemical conversion to OH. This instrument operates in two different modes: the ROx mode (sum of OH, HO2, and RO2) and the HOx mode (sum of OH and HO2). The HOx mode is used to derive the RO2 data from the ROx measurements. A model approach was used during instrumental development to identify the key parameters needed for the conversion process in front of the detection area and to optimize sensitivity. The instrument was then carefully characterized in various lab experiments, where it could be shown that the wall losses for HO2 are negligible and that nearly all HO2 is converted to OH in front of the detection zone. The pressure and temperature dependencies were also analyzed and assured that the instrument does not show any photolytical interference. As the instrument is calibrated with only one kind of peroxy radicals it was very important that the differences in sensitivity for different peroxy radicals are acceptable. Lab experiments as well as first results from the HOPE 2012 intensive field campaign, which took place in summer 2012 at the Global Atmosphere Watch (GAW) station of the German Weather Service, will be discussed.

Oxygen transmittance correction for solar-induced chlorophyll fluorescence measured on proximal sensing: application to the NASA-GSFC fusion tower

Science.gov (United States)

Since oxygen (O2) absorption of light becomes more pronounced at higher pressure levels, even a few meters distance between the target and the sensor can strongly affect canopy leaving Solar-Induced chlorophyll Fluorescence (SIF) retrievals. This study was conducted to quantify the consequent error ...

Laser-induced fluorescence spectra of Ba+*-He exciplexes produced in cold He gas

International Nuclear Information System (INIS)

Fukuyama, Yoshimitsu; Matsuo, Yukari; Moriwaki, Yoshiki

2004-01-01

We report the observation of laser-induced fluorescence spectra of Ba +* -He exciplexes. The experiment is carried out in an environment of cold gaseous helium at a temperature range of 3-30 K. We have observed the emission spectra of exciplexes by means of excitation of the 6p 2 P 32 2 S 12 transition of Ba + ions. It is found that these spectra are redshifted from the D2 emission line in the free space and are composed of several peaks. The experimental results are reproduced well by theoretical calculation of the emission spectra for vibrational levels of Ba +* -He. We also investigate the vibrational dynamics of the 6p 2 Π 32 state of Ba + *-He, and we have determined the collision-induced vibrational relaxation cross sections of the 6p 2 Π 32 state to be 9.7±1.1 A 2 at 15 K

Detection of Counterfeit Tequila by Fluorescence Spectroscopy

Directory of Open Access Journals (Sweden)

José Manuel de la Rosa Vázquez

2015-01-01

Full Text Available An ultraviolet (UV light induced fluorescence study to discriminate fake tequila from genuine ones is presented. A portable homemade system based on four light emitting diodes (LEDs from 255 to 405 nm and a miniature spectrometer was used. It has been shown that unlike fake and silver tequila, which produce weak fluorescence signal, genuine mixed, rested, and aged tequilas show high fluorescence emission in the range from 400 to 750 nm. The fluorescence intensity grows with aging in 100% agave tequila. Such fluorescence differences can even be observed with naked eyes. The presented results demonstrate that the fluorescence measurement could be a good method to detect counterfeit tequila.

Kerosene detection using laser induced fluorescence imaging for aeronautical engines application; Detection du kerozene par imagerie de fluorescence induite par laser, pour application sur foyer aeronautique

Energy Technology Data Exchange (ETDEWEB)

Baranger, Ph.

2004-10-15

The new concepts of aeronautical engines, developed to follow the evolution of the European standards of pollution, are generally based on an improvement of the processes of liquid fuel injection and mixture in the combustion chamber. There is currently no model mature enough to work without experimental validation. The purpose of this thesis is to assess the possibility of measuring the kerosene (Jet A1) vapour distribution by PLIF (Planar Laser Induced Fluorescence). That measurement technique must quantitatively image the instantaneous concentrations fields of the vaporized fuel in a spray. The implementation of such a technique needs an experimental spectroscopic study, which was realized on the vapour of fuel. First of all, this study allowed us to determine the properties of the kerosene fluorescence spectrum versus physical parameters such as temperature, pressure or gas mixture composition, especially in presence of oxygen molecules. Then, it was shown that the fluorescence spectrum of the fuel could be reproduce in all physical conditions by a single mixture of four aromatics. Their photophysical properties were also analyzed. Following this spectroscopic study, a phenomenological model for the fluorescence of the gaseous fuel was set up. This model led us to a protocol for an optical diagnostic on this fuel vapour. An experiment was set up to test the implementation and the limits of this technique in simple laboratory conditions. This experiment confirmed that this is indeed a promising technique for the diagnostic of the fuel vapour in aeronautical engine. (author)

Use of a laser-induced fluorescence thermal imaging system for film cooling heat transfer measurement