Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection.

PubMed

Yun, Kangsun

2017-10-12

Urinary tract junction obstruction defects are congenital anomalies inducing hydronephrosis and hydroureter. Murine urinary tract junction obstruction defects can be assessed by tracking methylene blue dye flow within the urinary system. Methylene blue dye is injected into the renal pelvis of perinatal embryonic kidneys and dye flow is monitored from the renal pelvis of the kidney through the ureter and into the bladder lumen after applying hydrostatic pressure. Dye accumulation will be evident in the bladder lumen of the normal perinatal urinary tract, but will be constrained between the renal pelvis and the end point of an abnormal ureter, if urinary tract obstructions occur. This method facilitates the confirmation of urinary tract junction obstructions and visualization of hydronephrosis and hydroureter. This manuscript describes a protocol for methylene blue dye injection into the renal pelvis to confirm urinary tract junction obstructions.

Insights into the Mechanism of a Covalently Linked Organic Dye-Cobaloxime Catalyst System for Dye-Sensitized Solar Fuel Devices.

PubMed

Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández-Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif; Tian, Haining

2017-06-09

A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye-catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye-catalyst system on the photocathode is proposed on the basis of this study. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Development of New Laser Protective Dyes. Phase 2.

DTIC Science & Technology

DYE LASERS, PROTECTION, LASERS, DYES , HAZARDS, SYNTHESIS, EYE SAFETY, OPTICAL MATERIALS, PLASTICS, LENSES, THERMAL STABILITY, CYANINE DYES , POLYCARBONATES, INJECTION MOLDING, NEAR INFRARED RADIATION, FLUORENES.

Intrathecal Spread of Injectate Following an Ultrasound-Guided Selective C5 Nerve Root Injection in a Human Cadaver Model.

PubMed

Falyar, Christian R; Abercrombie, Caroline; Becker, Robert; Biddle, Chuck

2016-04-01

Ultrasound-guided selective C5 nerve root blocks have been described in several case reports as a safe and effective means to anesthetize the distal clavicle while maintaining innervation of the upper extremity and preserving diaphragmatic function. In this study, cadavers were injected with 5 mL of 0.5% methylene blue dye under ultrasound guidance to investigate possible proximal and distal spread of injectate along the brachial plexus, if any. Following the injections, the specimens were dissected and examined to determine the distribution of dye and the structures affected. One injection revealed dye extended proximally into the epidural space, which penetrated the dura mater and was present on the spinal cord and brainstem. Dye was noted distally to the divisions in 3 injections. The anterior scalene muscle and phrenic nerve were stained in all 4 injections. It appears unlikely that local anesthetic spread is limited to the nerve root following an ultrasound-guided selective C5 nerve root injection. Under certain conditions, intrathecal spread also appears possible, which has major patient safety implications. Additional safety measures, such as injection pressure monitoring, should be incorporated into this block, or approaches that are more distal should be considered for the acute pain management of distal clavicle fractures.

Revealing the influence of Cyano in Anchoring Groups of Organic Dyes on Adsorption Stability and Photovoltaic Properties for Dye-Sensitized Solar Cells.

PubMed

Chen, Wei-Chieh; Nachimuthu, Santhanamoorthi; Jiang, Jyh-Chiang

2017-07-10

Determining an ideal adsorption configuration for a dye on the semiconductor surface is an important task in improving the overall efficiency of dye-sensitized solar cells. Here, we present a detailed investigation of different adsorption configurations of designed model dyes on TiO 2 anatase (101) surface using first principles methods. Particularly, we aimed to investigate the influence of cyano group in the anchoring part of dye on its adsorption stability and the overall photovoltaic properties such as open circuit voltage, electron injection ability to the surface. Our results indicate that the inclusion of cyano group increases the stability of adsorption only when it adsorbs via CN with the surface and it decreases the photovoltaic properties when it does not involve in binding. In addition, we also considered full dyes based on the results of model dyes and investigated the different strength of acceptor abilities on stability and electron injection ability. Among the various adsorption configurations considered here, the bidentate bridging mode (A3) is more appropriate one which has higher electron injection ability, larger V OC value and more importantly it has higher dye loading on the surface.

Investigation of the weak binding of a tetrahistidine-tagged peptide to quantum dots by using capillary electrophoresis with fluorescence detection.

PubMed

Qin, Haifang; Jiang, Xiyuan; Fan, Jie; Wang, Jianpeng; Liu, Li; Qiu, Lin; Wang, Jianhao; Jiang, Pengju

2017-01-01

Capillary electrophoresis with fluorescence detection was utilized to probe the self-assembly between cyanine group dye labeled tetrahistidine containing peptide and CdSe/ZnS quantum dots, inside the capillary. Quantum dots and cyanine group dye labeled tetrahistidine containing peptide were injected into the capillary one after the other and allowed to self-assemble. Their self-assembly resulted into a measurable Förster resonance energy transfer signal between quantum dots and cyanine group dye labeled tetrahistidine containing peptide. The Förster resonance energy transfer signal increased upon increasing the cyanine group dye labeled tetrahistidine containing peptide/quantum dot molar ratio and reached a plateau at the 32/1 molar ratio. Additionally, the Förster resonance energy transfer signal was also affected by the increment of the interval time of injection and the sampling time. Online ligand exchange experiments were used to assess, the potential of a monovalent ligand of imidazole and a hexavalent ligand peptide, to displace surface bound cyanine group dye labeled peptide ligands from the quantum dots surface. Under optimal conditions, a linear relationship between the integrated peak areas and hexavalent ligand peptide was obtained at a hexavalent ligand concentration range of 0-0.5 mM. Therefore, the present assay has the potential to be applied in the online ligands detection. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Theoretical and experimental analysis of injection seeding a Q-switched alexandrite laser

NASA Technical Reports Server (NTRS)

Prasad, C. R.; Lee, H. S.; Glesne, T. R.; Monosmith, B.; Schwemmer, G. K.

1991-01-01

Injection seeding is a method for achieving linewidths of less than 500 MHz in the output of broadband, tunable, solid state lasers. Dye lasers, CW and pulsed diode lasers, and other solid state lasers have been used as injection seeders. By optimizing the fundamental laser parameters of pump energy, Q-switched pulse build-up time, injection seed power and mode matching, one can achieve significant improvements in the spectral purity of the Q-switched output. These parameters are incorporated into a simple model for analyzing spectral purity and pulse build-up processes in a Q-switched, injection-seeded laser. Experiments to optimize the relevant parameters of an alexandrite laser show good agreement.

Time-of-travel data for Nebraska streams, 1968 to 1977

USGS Publications Warehouse

Petri, L.R.

1984-01-01

This report documents the results of 10 time-of-travel studies, using ' dye-tracer ' methods, conducted on five streams in Nebraska during the period 1968 to 1977. Streams involved in the studies were the North Platte, North Loup, Elkhorn, and Big Blue Rivers and Salt Creek. Rhodamine WT dye in a 20 percent solution was used as the tracer for all 10 time-of-travel studies. Water samples were collected at several points below each injection site. Concentrations of dye in the samples were measured by determining fluorescence of the sample and comparing that value to fluorescence-concentration curves. Stream discharges were measured before and during each study. Results of each time-by-travel study are shown on two tables and on graph. The first table shows water discharge at injection and sampling sites, distance between sites, and time and rate of travel of the dye between sites. The second table provides descriptions of study sites, amounts of dye injected in the streams, actual sampling times, and actual concentrations of dye detected. The graphs for each time-of-travel study provide indications of changing travel rates between sampling sites, information on length of dye clouds, and times for dye passage past given points. (USGS)

Development of New Laser Protective Dyes

DTIC Science & Technology

1993-07-31

Science’s Phase I research, the feasibility of thermally stabilizing cyanine and squarylium dyes for simulated polycarbonate injection-molding... SQUARYLIUM & CROCONIUM FIUORENE DYE SYNTHESIS SYNTHESIS OF NEW DYES DYE SYNTHESES IENGFICA TION ASYNTHESIS OF SUSSTITUTED DYES EVELOP OH TECHNOLOGIES...region, three dyes were successfully extruded into PETG and/or PC: (a.) the croconium dye SS-1044 (,%max = 834 um in PETG). (b.) the squarylium dye

The precision of a special purpose analog computer in clinical cardiac output determination.

PubMed Central

Sullivan, F J; Mroz, E A; Miller, R E

1975-01-01

Three hundred dye-dilution curves taken during our first year of clinical experience with the Waters CO-4 cardiac output computer were analyzed to estimate the errors involved in its use. Provided that calibration is accurate and 5.0 mg of dye are injected for each curve, then the percentage standard deviation of measurement using this computer is about 8.7%. Included in this are the errors inherent in the computer, errors due to baseline drift, errors in the injection of dye and acutal variation of cardiac output over a series of successive determinations. The size of this error is comparable to that involved in manual calculation. The mean value of five successive curves will be within 10% of the real value in 99 cases out of 100. Advances in methodology and equipment are discussed which make calibration simpler and more accurate, and which should also improve the quality of computer determination. A list of suggestions is given to minimize the errors involved in the clinical use of this equipment. Images Fig. 4. PMID:1089394

Three-dimensional dynamics of temperature fields in phantoms and biotissue under IR laser photothermal therapy using gold nanoparticles and ICG dye

NASA Astrophysics Data System (ADS)

Akchurin, Georgy G.; Garif, Akchurin G.; Maksimova, Irina L.; Skaptsov, Alexander A.; Terentyuk, Georgy S.; Khlebtsov, Boris N.; Khlebtsov, Nikolai G.; Tuchin, Valery V.

2010-02-01

We describe applications of silica (core)/gold (shell) nanoparticles and ICG dye to photothermal treatment of phantoms, biotissue and spontaneous tumor of cats and dogs. The laser irradiation parameters were optimized by preliminary experiments with laboratory rats. Three dimensional dynamics of temperature fields in tissue and solution samples was measured with a thermal imaging system. It is shown that the temperature in the volume region of nanoparticles localization can substantially exceed the surface temperature recorded by the thermal imaging system. We have demonstrated effective optical destruction of cancer cells by local injection of plasmon-resonant gold nanoshells and ICG dye followed by continuous wave (CW) diode laser irradiation at wavelength 808 nm.

Free-hand ultrasound guidance permits safe and efficient minimally invasive intrathymic injections in both young and aged mice

PubMed Central

Tuckett, Andrea Z.; Zakrzewski, Johannes L.; Li, Duan; van den Brink, Marcel R.M.; Thornton, Raymond H.

2014-01-01

The goal of this study was to evaluate whether using an aseptic free-hand approach for ultrasound-guided injection facilitates injection into the thymic gland in mice. We used this interventional radiology technique in young, aged, and immunodeficient mice and found that the thymus was visible in all cases. The mean injection period was 8 s in young mice and 19 s in aged or immunodeficient mice. Injection accuracy was confirmed by intrathymic location of an injected dye, or by in vivo bioluminescence imaging of injected luciferase-expressing cells. Accurate intrathymic injection was confirmed in 97% of cases. No major complications were observed. We conclude that an aseptic free-hand technique for ultrasound-guided intrathymic injection is safe, accurate, and reduces the time required for intrathymic injections. This method facilitates large-scale experiments, injection of individual thymic lobes, and is clinically relevant. PMID:25701534

Dye laser traveling wave amplifier

NASA Technical Reports Server (NTRS)

Davidson, F.; Hohman, J.

1985-01-01

Injection locking was applied to a cavity-dumped coaxial flashlamp pumped dye laser in an effort to obtain nanosecond duration pulses which have both high energy and narrow-linewidth. In the absence of an injected laser pulse, the cavity-dumped dye laser was capable of generating high energy (approx. 60mJ) nanosecond duration output pulses. These pulses, however, had a fixed center wavelength and were extremely broadband (approx. 6nm FWHM). Experimental investigations were performed to determine if the spectral properties of these outputs could be improved through the use of injection-locking techniques. A parametric study to determine the specific conditions under which the laser could be injection-locked was also carried out. Significant linewidth reduction to 0.0015nm) of the outputs was obtained through injection-locking but only at wavelengths near the peak lasing wavelength of the dye. It was found, however; that by inserting weakly dispersive tuning elements in the laser cavity, these narrow-linewidth outputs could be obtained over a wide (24nm) tuning range. Since the tuning elements had low insertion losses, the tunability of the output was obtained without sacrificing output pulse energy.

Cryo-Assisted Resection En Bloc, and Cryoablation In Situ, of Primary Breast Cancer Coupled With Intraoperative Ultrasound-Guided Tracer Injection: A Preliminary Clinical Study.

PubMed

Korpan, Nikolai N; Xu, Kecheng; Schwarzinger, Philipp; Watanabe, Masashi; Breitenecker, Gerhard; Patrick, Le Pivert

2018-01-01

The aim of the study was to perform cryosurgery on a primary breast tumor, coupled with simultaneous peritumoral and intratumoral tracer injection of a blue dye, to evaluate lymphatic mapping. We explored the ability of our strategy to prevent tumor cells, but not that of injected tracers, to migrate to the lymphovascular drainage during conventional resection of frozen breast malignancies. Seventeen patients aged 51 (14) years (mean [standard deviation]), presenting primary breast cancer with stage I to IV, were randomly selected and treated in The Rudolfinerhaus Private Clinic in Vienna, Austria, and included in this preliminary clinical study. Under intraoperative ultrasound, 14 patients underwent curative cryo-assisted tumor resection en bloc, coupled with peritumoral tracer injection, which consisted of complete tumor freezing and concomitant peritumor injection with a blue dye, before resection and sentinel lymph node dissection (group A). Group B consists of 3 patients previously refused any standard therapy and had palliative tumor cryoablation in situ combined with intratumoral tracer injection. The intraoperative ultrasound facilitated needle positioning and dye injection timing. In group A, the frozen site extruded the dye that was distributed through the unfrozen tumor, the breast tissue, and the resection cavity for 12 patients. One to 4 lymph nodes were stained for 10 of 14 patients. The resection margin was evaluable. Our intraoperative ultrasound-guided performance revealed the injection and migration of a blue dye during the frozen resection en bloc and cryoablation in situ of primary breast tumors. Sentinel lymph node mapping, pathological determination of the tumor, and resection margins were achievable. The study paves the way for intraoperative cryo-assisted therapeutic strategies for breast cancer.

Near-infrared voltage-sensitive fluorescent dyes optimized for optical mapping in blood-perfused myocardium.

PubMed

Matiukas, Arvydas; Mitrea, Bogdan G; Qin, Maochun; Pertsov, Arkady M; Shvedko, Alexander G; Warren, Mark D; Zaitsev, Alexey V; Wuskell, Joseph P; Wei, Mei-de; Watras, James; Loew, Leslie M

2007-11-01

Styryl voltage-sensitive dyes (e.g., di-4-ANEPPS) have been used successfully for optical mapping in cardiac cells and tissues. However, their utility for probing electrical activity deep inside the myocardial wall and in blood-perfused myocardium has been limited because of light scattering and high absorption by endogenous chromophores and hemoglobin at blue-green excitation wavelengths. The purpose of this study was to characterize two new styryl dyes--di-4-ANBDQPQ (JPW-6003) and di-4-ANBDQBS (JPW-6033)--optimized for blood-perfused tissue and intramural optical mapping. Voltage-dependent spectra were recorded in a model lipid bilayer. Optical mapping experiments were conducted in four species (mouse, rat, guinea pig, and pig). Hearts were Langendorff perfused using Tyrode's solution and blood (pig). Dyes were loaded via bolus injection into perfusate. Transillumination experiments were conducted in isolated coronary-perfused pig right ventricular wall preparations. The optimal excitation wavelength in cardiac tissues (650 nm) was >70 nm beyond the absorption maximum of hemoglobin. Voltage sensitivity of both dyes was approximately 10% to 20%. Signal decay half-life due to dye internalization was 80 to 210 minutes, which is 5 to 7 times slower than for di-4-ANEPPS. In transillumination mode, DeltaF/F was as high as 20%. In blood-perfused tissues, DeltaF/F reached 5.5% (1.8 times higher than for di-4-ANEPPS). We have synthesized and characterized two new near-infrared dyes with excitation/emission wavelengths shifted >100 nm to the red. They provide both high voltage sensitivity and 5 to 7 times slower internalization rate compared to conventional dyes. The dyes are optimized for deeper tissue probing and optical mapping of blood-perfused tissue, but they also can be used for conventional applications.

Investigation of new dyes for chromovitrectomy: preclinical biocompatibility of trisodium, orangell and methyl violet.

PubMed

Badaro, Emmerson; Souza-Lima, Rodrigo A; Novais, Eduardo A; Maia, Mauricio; Hirai, Flávio; Meyer, Carsten H; Farah, Michel Eid; Rodrigues, Eduardo B

2015-01-01

To investigate the retinal toxicity by electroretinography (ERG), clinical examination and histology after intravitreal injection of biological stains in two concentrations: Trisodium (0.50 g/L and 1.00 g/L), Orangell (0.25 g/L and 1.00 g/L) and Methyl Violet (0.50 g/L and 1.00 g/L). Eighteen New-Zealand albinos rabbits were assigned in six groups (n = 3 in each group). The animals in group 1 received Trisodium in the dose of 0.50 g/L and group 2 received 1.00 g/L; Group 3 received Orangell in the dose of 0.25 g/L and group 4 received 1.00 g/L; Group 5 received Methyl Violet in the dose of 1.00 g/L and group 6 received 0.50 g/L. A volume of 0.05 mL of dye was injected in the right eyes, whereas the left eyes received the same volume of balanced salt solution (BSS) as control. ERG recordings and clinical examination were performed at baseline and seven days after intravitreal injection. The ERG responses at one week after injection were compared with baseline levels. A decrease in the post-injection amplitude of more than 50% was considered remarkable. After the 7-day follow-up, rabbits were euthanized and eye enucleated for light microscopy (LM) histological evaluation. At clinical examination by indirect ophthalmoscopy seven days after dye injection, all eyes were negative for cataract, hemorrhage, retinal detachment, and intraocular opacities. Amplitude analysis of maximum scotopic b-wave showed no significant reduction in either dye injected or control eyes. Neither dye nor BSS caused significant retinal alteration on LM at doses tested. Trisodium, Orangell and Methyl Violet can be applied in future studies in order to prove the capacity to stain preretinal tissues and vitreous without toxicity. The three dyes did not induce significant ERG amplitude reduction or LM alterations in this preliminary experimental research. Trisodium, Orangell and Methyl Violet may be potentially useful vital dyes for ocular surgery, and deserve further investigation.

Carbocyanine dye labeling reveals a new motor nucleus in octopus brain.

PubMed

Robertson, J D; Schwartz, O M; Lee, P

1993-02-22

This work aims at a better understanding of the organization of the brain of Octopus vulgaris, emphasizing the touch and visual learning centers. We injected the carbocyanine dye, DiI, into the cerebrobrachial connectives and, separately, into the brachial nerves of living octopuses. In both experiments, retrogradely transported granules of DiI appeared in motor neurons in the superior buccal, posterior buccal and subvertical lobes and in a hitherto unsuspected motor nucleus of several hundred neurons in the posterior dorsal basal and median basal lobes. In addition we labeled afferent fibers by injecting DiI into the caudal (sensory) division of the cerebrobrachial connective on one side; the label spread throughout the superior buccal, posterior buccal and the lateral and median inferior frontal lobes mainly on the injected side. It extended through the cerebral tract into the subvertical lobe, into the superior frontal lobe through the interfrontal tract, through the posterior buccal commissure into the opposite posterior buccal lobe and into the median inferior frontal lobe. The work suggests a new function for the posterior dorsal and median basal lobes, which are shown for the first time to project through the inferior frontal lobe system into the brachial nerves. In addition it represents the first full report of the successful use of the carbocyanine dyes DiI and DiO for labeling nerve tissue in a live invertebrate animal.

The Interior Olivary Complex of Guinea Pig: Cytoarchitecture and Cellular Morphology

DTIC Science & Technology

1986-01-01

The oscillatory phenomenon ap- dye -coupling [471 between 1.0. cells might have been pre- peared in a sampling of neurons from all of the...information derived from injections of the ing of multiple cells from the Lucifer yellow injection into fluorescent dye Lucifer yellow revealed that...aggregates of only one 1.0. neuron [41. The early Golgi analyses also rv- inferior olive neurons are dye -coupled, presumably through vealed at least two

97% accuracy of intra-articular glenohumeral injection with a modified (Delaware) posterior bone touch technique.

PubMed

Axe, Jeremie M; Axe, Michael J

2013-10-01

Unguided approaches have not demonstrated evidence of highly accurate intra-articular glenohumeral injections. The purpose of this study was to assess the accuracy of a posterior approach bone touch technique in conscious subjects without shoulder pathology as a first step in developing an accurate, reliable technique for use in patients. Twenty-six young subjects (age 22-26) without shoulder pathology (BMI 24 +/- 3), had bilateral shoulders injected while awake and seated. A 20 gauge 3.5-inch needle was introduced 1.5 cm below the scapular spine mid-way between the posterior lateral acromial corner and the posterior axillary crease. In Trial I, 20 shoulders were injected. After touching the humerus, the arm was oscillated. The needle advanced to 4-5 cm and 10 mL of dye injected. Pop and ease of flow were recorded. Immediate room change, spot fluoroscopy, and independent experienced radiology reading followed. In Trial II, 32 shoulders were injected. The technique was modified to touching the humerus, externally rotating the arm 25 degrees, and while remaining in bone contact, delivering 10 mL of dye. The same data as Trial I was recorded. In Trial I, 14/20 (70 percent) had dye within the glenohumeral joint. Five of seven failures were too anterior showing dye around the subscapularis muscle and all were associated with a pop. In Trial II, 31/32 (97 percent) had dye within glenohumeral joint. Twenty-three of 32 (72 percent) had a "pop," including the failure. Overall, 45/52 (87 percent) had dye within glenohumeral joint. Thirty-one of 52 (71 percent) of all shoulders had a "pop." Twenty-three of 52 (44 percent) shoulders had pain, resolving within 24 hours. A modified (Delaware) posterior bone touch technique for glenohumeral joint injection is 97 percent accurate in conscious healthy young subjects. Pop and ease of flow are not always indicative of correct needle placement. This study serves as an important first step in determining an optimum approach for injecting pathologic glenohumeral joints with corticosteroids or hyaluronic acid. IV Case Series.

Short-term in vivo evaluation of novel vital dyes for intraocular surgery.

PubMed

Haritoglou, Christos; Tadayoni, Ramin; May, Christian A; Gass, Carolin A; Freyer, Wolfgang; Priglinger, Siegfried G; Kampik, Anselm

2006-01-01

To evaluate the staining characteristics and safety of potential new dyes for intraocular surgery in porcine eyes. Four dyes in different solutions (light green SF yellowish [LGSF]: 2%; copper(II) phthalocyanine-tetrasulfonic acid [E68]: 2% and 0.5%; bromophenol blue [BPB]: 2%, 1%, and 0.2%; and Chicago blue [CB]: 2% and 0.5%) were included in this investigation. All dyes were dissolved and diluted using balanced salt solution (BSS plus; Alcon Laboratories, Inc., Fort Worth, TX). After triamcinolone-assisted vitrectomy on 10 porcine eyes in vivo, the dyes were first injected into the air-filled vitreous cavity. After 1 minute, the dye was removed by irrigation with BSS, and the staining effect was graded by two examiners. After vitrectomy, the same dyes and concentrations were injected in the air-filled anterior chamber to stain the lens capsule of the same eye. After surgery, the eyes were enucleated and underwent fixation for light and electron microscopy. The animals were killed by injection of pentobarbital (50 mg/kg). For controls, each BSS plus alone and indocyanine green 0.5% were applied in one eye. On the retinal surface, bright staining of the retinal surface was seen after application of BPB 2% and 1%. The staining effect was less pronounced but still very good using E68 2%, and CB 2% and weak using BPB 0.2%, E68 0.5% and CB 0.5% as well as indocyanine green 0.5%. No staining of the retinal surface but of the vitreous was seen after application of LGSF 2%. The lens capsule stained very well with E68 2%, CB 2% and 0.5%, and BPB 2%, 1%, and 0.2% but not with LGSF. No histologic abnormalities were seen after the application in any eye after dye injection. No dye-related complications occurred during surgery. In this study, we identified three dyes with satisfying staining characteristics in both anterior and posterior segments. Because BPB stained the retinal surface and lens capsule at a low concentration (0.2%) with no signs of toxicity, this dye seems to be the most promising candidate for application in humans.

Free-hand ultrasound guidance permits safe and efficient minimally invasive intrathymic injections in both young and aged mice.

PubMed

Tuckett, Andrea Z; Zakrzewski, Johannes L; Li, Duan; van den Brink, Marcel R M; Thornton, Raymond H

2015-04-01

The goal of this study was to evaluate whether use of an aseptic free-hand approach to ultrasound-guided injection facilitates injection into the thymic gland in mice. We used this interventional radiology technique in young, aged and immunodeficient mice and found that the thymus was visible in all cases. The mean injection period was 8 seconds in young mice and 19 seconds in aged or immunodeficient mice. Injection accuracy was confirmed by intrathymic location of an injected dye or by in vivo bioluminescence imaging of injected luciferase-expressing cells. Accurate intrathymic injection was confirmed in 97% of cases. No major complications were observed. We conclude that an aseptic freehand technique for ultrasound-guided intrathymic injection is safe and accurate and reduces the time required for intrathymic injections. This method facilitates large-scale experiments and injection of individual thymic lobes and is clinically relevant. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Assessment of Acridine Orange and SYTO 16 for in vivo imaging of the peritoneal tissues in mice

PubMed Central

Udovich, Joshua Anthony; Besselsen, David G.; Gmitro, Arthur F.

2009-01-01

The effect of peritoneal injection of Acridine Orange (AO) and SYTO 16 in mice was investigated. Images of peritoneal tissues stained with these dyes and obtained through a confocal microendoscope are presented. Seventy-five Balb/c mice were split into five groups and given peritoneal injections of dye or saline. The proportions of negative outcomes in each group were compared using confidence intervals and the Fisher's exact statistical test. A statistically significant increase in adverse events due to dye injection was not observed.These data provide an initial investigation into the safety of AO and SYTO 16 for in vivo imaging. PMID:19397741

Plasmon enhanced heterogeneous electron transfer with continuous band energy model

NASA Astrophysics Data System (ADS)

Zhao, Dandan; Niu, Lu; Wang, Luxia

2017-08-01

Photoinduced charge injection from a perylene dye molecule into the conduction band of a TiO2 system decorated by a metal nanoparticles (MNP) is studied theoretically. Utilizing the density matrix theory the charge transfer dynamics is analyzed. The continuous behavior of the TiO2 conduction band is accounted for by a Legendre polynomials expansion. The simulations consider optical excitation of the dye molecule coupled to the MNP and the subsequent electron injection into the TiO2 semiconductor. Due to the energy transfer coupling between the molecule and the MNP optical excitation and subsequent charge injection into semiconductor is strongly enhanced. The respective enhancement factor can reach values larger than 103. Effects of pulse duration, coupling strength and energetic resonances are also analyzed. The whole approach offers an efficient way to increase charge injection in dye-sensitized solar cells.

76 FR 81557 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-28

... Diesel Fuel and Kerosene Excise Tax; Dye Injection (NPRM). Abstract: The regulations relate to the diesel fuel and kerosene excise tax and reflect changes made by the American Jobs Creation Act of 2004 (Act) regarding mechanical dye injection systems. Under the Act, diesel fuel and kerosene that are to be used in a...

76 FR 51127 - Proposed Collection; Comment Request for Regulation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-17

... information collection requirements related to diesel fuel and kerosene excise tax; dye injection. DATES... Kerosene Excise Tax; Dye Injection. OMB Number: 1545-1418. Regulation Project Number: REG-154000-04 (T.D. 9199). Abstract: In order for diesel fuel and kerosene that is used in a nontaxable use to be exempt...

Concordance between peri-areolar blue dye and peri-incisional radiotracer injections for sentinel node mapping in patients with a history of primary breast cancer excisonal biopsy.

PubMed

Mehrabibahar, M; Azizi, S; Jangjoo, A; Saremi, E; Kakhki, V R Dabbagh; Sadeghi, R; Chicken, D W; Keshtgar, M

2014-01-01

We evaluated the concordance between peri-areolar blue dye and peri-incisional radiotracer injections for axillary sentinel node mapping of patients with the history of previous breast lesion excisional biopsy. 80 patients with the history of previous excisional biopsy of the breast lesions were included. All patients received two injections of 99mTc-antimony sulfide colloid in both ends of incision line in an intradermal fashion. 2 mL patient blue V dye was injection to all patients in the peri-areolar area of the index quadrant after induction of anesthesia. All blue or hot nodes were harvested as sentinel lymph nodes. At least one sentinel node could be detected during surgery in 79 patients. In total 94 sentinel nodes were detected. All detected sentinel nodes were hot. In three patients sentinel nodes were detected by gamma probe but not blue dye. The tumor location in all of these patients was in the upper lateral quadrant and the incision line was extended into the axillary tail of the breast in all of them. 91 out of 94 sentinel nodes were stained blue, which amounts to 95.8% concordance between blue dye and radiotracer on a per node analysis. Single peri-areolar injection in the index quadrant would suffice for sentinel node mapping of patients with history of excisional biopsy. Care should be taken in patients with large excisional biopsy in the extreme proximity to axilla.

Deep in vivo two-photon imaging of blood vessels with a new dye encapsulated in pluronic nanomicelles

NASA Astrophysics Data System (ADS)

Maurin, Mathieu; Stéphan, Olivier; Vial, Jean-Claude; Marder, Seth R.; van der Sanden, Boudewijn

2011-03-01

Our purpose is to test if Pluronic® fluorescent nanomicelles can be used for in vivo two-photon imaging of both the normal and the tumor vasculature. The nanomicelles were obtained after encapsulating a hydrophobic two-photon dye: di-stryl benzene derivative, in Pluronic block copolymers. Their performance with respect to imaging depth, blood plasma staining, and diffusion across the tumor vascular endothelium is compared to a classic blood pool dye Rhodamin B dextran (70 kDa) using two-photon microscopy. Pluronic nanomicelles show, like Rhodamin B dextran, a homogeneous blood plasma staining for at least 1 h after intravenous injection. Their two-photon imaging depth is similar in normal mouse brain, using 10 times less injected mass. In contrast with Rhodamin B dextran, no extravasation is observed in leaky tumor vessels due to their large size: 20-100 nm. In conclusion, Pluronic nanomicelles can be used as a blood pool dye, even in leaky tumor vessels. The use of Pluronic block copolymers is a valuable approach for encapsulating two-photon fluorescent dyes that are hydrophobic and not suitable for intravenous injection.

Accidental intra-arterial injection of fluorescein dye.

PubMed

Bovino, J A; Marcus, D F

1984-12-01

During fluorescein angiography, sodium fluorescein dye intended for intravenous use was inadvertently injected into an artery in the antecubital fossa. An immediate and dramatic orange discoloration of the skin distal to the injection combined with intense burning pain of the right forearm and hand were noted. The patient was treated with ice packs and analgesics. The fluorescein angiogram showed a delayed arm to eye circulation time, but was of normal quality. There were no long-term complications.

Adsorption orientation effects of porphyrin dyes on the performance of DSSC: Comparison of benzoic acid and tropolone anchoring groups binding onto the TiO2 anatase (101) surface

NASA Astrophysics Data System (ADS)

Zhu, Han-Cheng; Zhang, Ji; Wang, Ying-Lin

2018-03-01

A new porphyrin dye with tropolone anchoring group showing superior stability but lower efficiency versus the promising dye YD2-o-C8 with benzoic acid anchoring group was theoretically investigated for the first time. A series of important parameters related to the efficiency of DSSC were calculated to explore the nature of the experimentally observed lower efficiency and superior stability of tropolone-based solar cells. We found these two dyes with different anchoring groups show comparable electron injection and dye regeneration process. Interestingly, the red-shifted absorption spectrum, relatively weaker ability of releasing protons, and the larger conduction band energy shift of tropolone-based dyes all demonstrated it should show better performance than the benzoic acid dyes, which contradicts with the experimental results. However, through investigating the interaction between the porphyrin dye and the semiconductor by analyzing the electron localization function of the porphyrin dye and preforming energy decomposition analysis, we found that the direction of lone-pair electrons of carbonyl oxygen in the tropolone-based dye makes the dye prefer to adsorb on the surface in an inclined way, in contrary to the benzoic acid-based dye that favored a vertical adsorption. The inclined adsorption could significantly accelerate the charge recombination process between the injected electrons and the oxidized dye, leading to a decreased efficiency of DSSC.

High-sensitivity detection of biological amines using fast Hadamard transform CE coupled with photolytic optical gating.

PubMed

Braun, Kevin L; Hapuarachchi, Suminda; Fernandez, Facundo M; Aspinwall, Craig A

2007-08-01

Here, we report the first utilization of Hadamard transform CE (HTCE), a high-sensitivity, multiplexed CE technique, with photolytic optical gating sample injection of caged fluorescent labels for the detection of biologically important amines. Previous implementations of HTCE have relied upon photobleaching optical gating sample injection of fluorescent dyes. Photolysis of caged fluorescent labels reduces the fluorescence background, providing marked enhancements in sensitivity compared to photobleaching. Application of fast Hadamard transform CE (fHTCE) for fluorescein-based dyes yields a ten-fold higher sensitivity for photolytic injections compared to photobleaching injections, due primarily to the reduced fluorescent background provided by caged fluorescent dyes. Detection limits as low as 5 pM (ca. 18 molecules per injection event) were obtained with on-column LIF detection using fHTCE in less than 25 s, with the capacity for continuous, online separations. Detection limits for glutamate and aspartate below 150 pM (1-2 amol/injection event) were obtained using photolytic sample injection, with separation efficiencies exceeding 1 x 10(6) plates/m and total multiplexed separation times as low as 8 s. These results strongly support the feasibility of this approach for high-sensitivity dynamic chemical monitoring applications.

Photovoltaic studies of Dye Sensitized Solar cells Fabricated from Microwave Exposed Photo anodes

NASA Astrophysics Data System (ADS)

Ramachandran, Anju; Sreekala, C. O.; Sreelatha, K. S.; Jinchu, I.

2018-02-01

The configuration of Dye Sensitized solar cells (DSSC), consists of sintered nanoparticle titanium dioxide film, dyes, electrolyte and counter electrodes. Upon the absorption of photons by the dye molecules, excitons are generated, subsequently electrons are injected into the TiO2 photoanode. Afterward the electrons injected into the TiO2 photoanode, to produce photocurrent, scavenged by redox couple, and the hole transport to the photo cathode. The power conversion efficiency of the device depends on the amount of dye adsorbed by the photoanode. This paper explores in enhancing the efficiency of the device by controlled microwave exposure. With same exposure time, the photoanode is exposed at three different frequencies. SEM analysis is carried out to find the porosity of the photoanode on exposure. Current density is found to have an effect on microwave exposure.

Fragile X Mental Retardation Protein Restricts Small Dye Iontophoresis Entry into Central Neurons

PubMed Central

2017-01-01

Fragile X mental retardation protein (FMRP) loss causes Fragile X syndrome (FXS), a major disorder characterized by autism, intellectual disability, hyperactivity, and seizures. FMRP is both an RNA- and channel-binding regulator, with critical roles in neural circuit formation and function. However, it remains unclear how these FMRP activities relate to each other and how dysfunction in their absence underlies FXS neurological symptoms. In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpected and highly robust neuronal dye iontophoresis phenotype in the well mapped giant fiber (GF) circuit. Controlled dye injection into the GF interneuron results in a dramatic increase in dye uptake in neurons lacking FMRP. Transgenic wild-type FMRP reintroduction rescues the mutant defect, demonstrating a specific FMRP requirement. This phenotype affects only small dyes, but is independent of dye charge polarity. Surprisingly, the elevated dye iontophoresis persists in shaking B mutants that eliminate gap junctions and dye coupling among GF circuit neurons. We therefore used a wide range of manipulations to investigate the dye uptake defect, including timed injection series, pharmacology and ion replacement, and optogenetic activity studies. The results show that FMRP strongly limits the rate of dye entry via a cytosolic mechanism. This study reveals an unexpected new phenotype in a physical property of central neurons lacking FMRP that could underlie aspects of FXS disruption of neural function. SIGNIFICANCE STATEMENT FXS is a leading heritable cause of intellectual disability and autism spectrum disorders. Although researchers established the causal link with FMRP loss >;25 years ago, studies continue to reveal diverse FMRP functions. The Drosophila FXS model is key to discovering new FMRP roles, because of its genetic malleability and individually identified neuron maps. Taking advantage of a well characterized Drosophila neural circuit, we discovered that neurons lacking FMRP take up dramatically more current-injected small dye. After examining many neuronal properties, we determined that this dye defect is cytoplasmic and occurs due to a highly elevated dye iontophoresis rate. We also report several new factors affecting neuron dye uptake. Understanding how FMRP regulates iontophoresis should reveal new molecular factors underpinning FXS dysfunction. PMID:28887386

Tracer injection sites and combinations for sentinel lymph node detection in patients with endometrial cancer.

PubMed

Niikura, Hitoshi; Kaiho-Sakuma, Michiko; Tokunaga, Hideki; Toyoshima, Masafumi; Utsunomiya, Hiroki; Nagase, Satoru; Takano, Tadao; Watanabe, Mika; Ito, Kiyoshi; Yaegashi, Nobuo

2013-11-01

The aim of the present study was to clarify the most effective combination of injected tracer types and injection sites in order to detect sentinel lymph nodes (SLNs) in early endometrial cancer. The study included 100 consecutive patients with endometrial cancer treated at Tohoku University Hospital between June 2001 and December 2012. The procedure for SLN identification entailed either radioisotope (RI) injection into the endometrium during hysteroscopy (55 cases) or direct RI injection into the uterine cervix (45 cases). A combination of blue dye injected into the uterine cervix or uterine body intraoperatively in addition to preoperative RI injection occurred in 69 of 100 cases. All detected SLNs were recorded according to the individual tracer and the resultant staging from this method was compared to the final pathology of lymph node metastases including para-aortic nodes. SLN detection rate was highest (96%) by cervical RI injection; however, no SLNs were detected in para-aortic area. Para-aortic SLNs were detected only by hysteroscopic RI injection (56%). All cases with pelvic lymph node metastases were detected by pelvic SLN biopsy. Isolated positive para-aortic lymph nodes were detected in 3 patients. Bilateral SLN detection rate was high (96%; 26 of 27 cases) by cervical RI injection combined with dye. RI injection into the uterine cervix is highly sensitive in detection of SLN metastasis in early stage endometrial cancer. It is a useful and safe modality when combined with blue dye injection into the uterine body. © 2013.

Charge Transfer Dynamics at Dye-Sensitized ZnO and TiO2 Interfaces Studied by Ultrafast XUV Photoelectron Spectroscopy

PubMed Central

Borgwardt, Mario; Wilke, Martin; Kampen, Thorsten; Mähl, Sven; Xiao, Manda; Spiccia, Leone; Lange, Kathrin M.; Kiyan, Igor Yu.; Aziz, Emad F.

2016-01-01

Interfacial charge transfer from photoexcited ruthenium-based N3 dye molecules into ZnO thin films received controversial interpretations. To identify the physical origin for the delayed electron transfer in ZnO compared to TiO2, we probe directly the electronic structure at both dye-semiconductor interfaces by applying ultrafast XUV photoemission spectroscopy. In the range of pump-probe time delays between 0.5 to 1.0 ps, the transient signal of the intermediate states was compared, revealing a distinct difference in their electron binding energies of 0.4 eV. This finding strongly indicates the nature of the charge injection at the ZnO interface associated with the formation of an interfacial electron-cation complex. It further highlights that the energetic alignment between the dye donor and semiconductor acceptor states appears to be of minor importance for the injection kinetics and that the injection efficiency is dominated by the electronic coupling. PMID:27073060

Tumor implantation model for rapid testing of lymphatic dye uptake from paw to node in small animals

NASA Astrophysics Data System (ADS)

DSouza, Alisha V.; Elliott, Jonathan T.; Gunn, Jason R.; Barth, Richard J.; Samkoe, Kimberley S.; Tichauer, Kenneth M.; Pogue, Brian W.

2015-03-01

Morbidity and complexity involved in lymph node staging via surgical resection and biopsy calls for staging techniques that are less invasive. While visible blue dyes are commonly used in locating sentinel lymph nodes, since they follow tumor-draining lymphatic vessels, they do not provide a metric to evaluate presence of cancer. An area of active research is to use fluorescent dyes to assess tumor burden of sentinel and secondary lymph nodes. The goal of this work was to successfully deploy and test an intra-nodal cancer-cell injection model to enable planar fluorescence imaging of a clinically relevant blue dye, specifically methylene blue - used in the sentinel lymph node procedure - in normal and tumor-bearing animals, and subsequently segregate tumor-bearing from normal lymph nodes. This direct-injection based tumor model was employed in athymic rats (6 normal, 4 controls, 6 cancer-bearing), where luciferase-expressing breast cancer cells were injected into axillary lymph nodes. Tumor presence in nodes was confirmed by bioluminescence imaging before and after fluorescence imaging. Lymphatic uptake from the injection site (intradermal on forepaw) to lymph node was imaged at approximately 2 frames/minute. Large variability was observed within each cohort.

Photoactive layer based on T-shaped benzimidazole dyes used for solar cell: from photoelectric properties to molecular design

NASA Astrophysics Data System (ADS)

Xu, Beibei; Li, Yuanzuo; Song, Peng; Ma, Fengcai; Sun, Mengtao

2017-03-01

Three benzimidazole-based organic dyes, possessing the same triphenylamine donors and cyanoacrylic acid acceptors with the bithiophene π-bridges combined in different nuclear positions of benzimidazole, were investigated in the utility of dye-sensitizer solar cells. The structure, molecular orbital and energy, absorption spectra and some important parameters (such as light harvesting efficiency (LHE), electron injection driving force, the electron injection time, chemical reactivity parameters, vertical dipole moment as well as interaction models of dye-I2) were obtained according to Newns-Anderson model and DFT calculation. The process and strength of charge transfer and separation were visualized with charge different density and index of spatial extent (S, D and Δq). Current work paid attention to the new T-shaped dyes to reveal the relation between the structure and photoelectric performance. Furthermore, nine dyes (substitution of alkyl chains and π-bridges) have been designed and characterized to screen promising sensitizer candidates with excellent photo-electronic properties.

In vivo biocompatibility of a new cyanine dye for ILM peeling.

PubMed

Thaler, S; Haritoglou, C; Schuettauf, F; Choragiewicz, T; May, C A; Gekeler, F; Fischer, M D; Langhals, H; Schatz, A

2015-03-01

To investigate the biocompatibility of the new cyanine dye: 3,3'-Di-(4-sulfobutyl)-1,1,1',1'-tetramethyl-di-1H-benz[e]indocarbocyanine (DSS) as a vital dye for intraocular application in an in vivo rat model and to evaluate the effects of this dye on retinal structure and function. DSS at a concentration of 0.5% was applied via intravitreal injections to adult Brown Norway rats with BSS serving as a control. Retinal toxicity was assessed 7 days later by means of retinal ganglion cell (RGC) counts, light microscopy, optical coherence tomography (OCT), and electroretinography (ERG). No significant decrease in RGC numbers was observed. No structural changes of the central retina were observed either in vivo (OCT) or under light microscopy. ERGs detected a temporary reduction of retinal function 7 days after injection; this was no longer evident 14 days after injection. DSS showed good biocompatibility in a well-established experimental in vivo setting and may be usable for intraocular surgery as an alternative to other cyanine dyes. In contrast to indocyanine green, it additionally offers fluorescence in the visual spectrum. Further studies with other animal models are needed before translation into clinical application.

Use of ground-water tracers to evaluate the hydraulic connection between Key Cave and the proposed industrial site near Florence, Alabama, 2000 and 2001

USGS Publications Warehouse

Kidd, Robert E.; Taylor, Charles J.; Stricklin, Victor E.

2001-01-01

In an effort to attract new industries and jobs, the city of Florence, Alabama has proposed development of an industrial park southwest of the city. Carbonate rock under-lines the area and sinkholes, springs, caves, and sinking streams are common. Key Cave, located about 5 miles southwest of the proposed park, is the only know habitat for the Alabama Cavefish (Speoplatyrhinus poulsoni). The Alabama Cavefish is a Federally designated Endangered Species, and Key Cave has been designated as Critical Habitat. The U.S. Geological Survey was requested by the city of Florence and the U.S. Fish and Wildlife Service to assist in determining if a hydraulic connection exists between the proposed industrial park and Key Cave. Dye tracing methods were used in the investigation to determine if a hydraulic connection exists. Dye tracing is a technique that involves labeling a discrete quantity of ground water with a fluorescent dye so that its flow in the subsurface can be tracked to a ground-water discharge point. Monitoring for dyes involved the use of passive dye detectors placed in springs, wells, caves and surface streams. During the passage of ground water containing fluorescent dye, the dye is absorbed and concentrated on the detectors. Spectrofluorometric analyses of the detectors determines the presence or absence of dye. Dye injected in well I-1 on January 10, 2001, was recovered from site 67, Cypress Creek at General John Coffee Highway (State Highway 20) on January 17, 2001. No dye was recovered from site 68, Cypress Creek at Waterloo Road (County Road 14), indicating an east-southeast flow path from well I-1 to Cypress Creek. No positive dye recovery was made from dye injected in well I-2 on January 10, 2001. Water samples collected from the well February 1 and 15, 2001, showed little movement into the ground-water system. Dye injected in well I-3 on January 10, 2001, was recovered at two sites in Key Cave and at other locations. This test indicates a hydraulic connection exists between Key Cave and the proposed industrial site.

Altered blood-brain barrier permeability and its effect on the distribution of Evans blue and sodium fluorescein in the rat brain applied by intracarotid injection.

PubMed

Kozler, P; Pokorný, J

2003-01-01

The aim was to study the blood-brain permeability according to the distribution in the rat brain of Evans blue (EB) and sodium fluorescein (NaFl) administered by an intracarotid injection. Eighteen animals were divided into six groups according to the state of the blood-brain barrier (BBB) at the moment when the dyes were being applied. In the first two groups, the BBB was intact, in groups 3 and 4 the barrier had been opened osmotically prior to the application of the dyes, and in groups 5 and 6 a cellular edema was induced by hyperhydration before administration of the dyes. The intracellular and extracellular distribution of the dyes was studied by fluorescence microscopy. The histological picture thus represented the morphological correlate of the way BBB permeability had been changed before the application of the dyes.

Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye‐Sensitized Solar Cell Performance

PubMed Central

Hao, Yan; Gabrielsson, Erik; Lohse, Peter William; Yang, Wenxing; Johansson, Erik M. J.; Hagfeldt, Anders

2015-01-01

Investigation of charge transfer dynamics in dye‐sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal‐free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron–hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2 to the cobalt‐based electrolyte. PMID:27722076

Contrast Dispersion Pattern and Efficacy of Corticosteroid at the Glenohumeral Joint in Adhesive Capsulitis.

PubMed

Kim, Sang Jun; Choi, Yu Seong

2015-01-01

Corticosteroid injection has a wide range of success in adhesive capsulitis but the reason for this has not yet been explained. We hypothesized that this difference might be due to the distribution of the corticosteroids injected into the joint cavity because particulate steroid deposits in the capsule and will not be moved over time by shoulder motion. The purpose of this study is to determine whether the therapeutic efficacy of particulate corticosteroid injection into the glenohumeral joint differs according to the dispersion pattern. Prospective evaluation. Outpatient clinics at a tertiary university hospital. Seventy-two patients diagnosed as having adhesive capsulitis received a corticosteroid injection at the glenohumeral joint. The posterior capsule and the subscapular bursa were selected as dispersion sites and the dispersion of contrast dye was expressed as a ratio (%). Two weeks and 3 months after the injection clinical improvement ("not improved," "slightly improved," "much improved"), numeric rating scale (NRS), and passive range of motions (PROM) were evaluated. The dispersion of the contrast dye was compared according to the clinical improvements by an analysis of variance test. Pearson correlation test was done to find the relationship between PROM and the dispersion and between change of NRS and the dispersion. The distribution in the subscapular area was 30.0% in the "much improved" group, 22.0% in the "slightly improved" group, and 37.1% in the "no improvement" group which was not significantly different (P = 0.179). Correlations between changes of NRS and the dye distribution were not statistically significant (P = 0.429 at 2 weeks and P = 0.629 at 3 months). The change of passive external rotation 3 months after the injection was significantly correlated with the dye distribution (P = 0.035). Because of diverse pathologic findings in adhesive capsulitis, further studies will be needed to address the effect of the dye distribution on the pain improvement according to pathologic findings revealed by magnetic resonance imaging (MRI). External rotation of the shoulder in adhesive capsulitis has greater improvement as the corticosteroid solutions injected into the glenohumeral joint are increasingly dispersed to the subscapularis area. However, this does not affect the pain improvement after the injection.

Effect of Molecular Coupling on Ultrafast Electron-Transfer and Charge-Recombination Dynamics in a Wide-Gap ZnS Nanoaggregate Sensitized by Triphenyl Methane Dyes.

PubMed

Debnath, Tushar; Maity, Partha; Dana, Jayanta; Ghosh, Hirendra N

2016-03-03

Wide-band-gap ZnS nanocrystals (NCs) were synthesized, and after sensitizing the NCs with series of triphenyl methane (TPM) dyes, ultrafast charge-transfer dynamics was demonstrated. HRTEM images of ZnS NCs show the formation of aggregate crystals with a flower-like structure. Exciton absorption and lumimescence, due to quantum confinement of the ZnS NCs, appear at approximately 310 and 340 nm, respectively. Interestingly, all the TPM dyes (pyrogallol red, bromopyrogallol red, and aurin tricarboxylic acid) form charge-transfer complexes with the ZnS NCs, with the appearance of a red-shifted band. Electron injection from the photoexcited TPM dyes into the conduction band of the ZnS NCs is shown to be a thermodynamically viable process, as confirmed by steady-state and time-resolved emission studies. To unravel charge-transfer (both electron injection and charge recombination) dynamics and the effect of molecular coupling, femtosecond transient absorption studies were carried out in TPM-sensitized ZnS NCs. The electron-injection dynamics is pulse-width-limited in all the ZnS/TPM dye systems, however, the back electron transfer differs, depending on the molecular coupling of the sensitizers (TPM dyes). The detailed mechanisms for the above-mentioned processes are discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Injection-depth-locking axial motion guided handheld micro-injector using CP-SSOCT.

PubMed

Cheon, Gyeong Woo; Huang, Yong; Kwag, Hye Rin; Kim, Ki-Young; Taylor, Russell H; Gehlbach, Peter L; Kang, Jin U

2014-01-01

This paper presents a handheld micro-injector system using common-path swept source optical coherence tomography (CP-SSOCT) as a distal sensor with highly accurate injection-depth-locking. To achieve real-time, highly precise, and intuitive freehand control, the system used graphics processing unit (GPU) to process the oversampled OCT signal with high throughput and a smart customized motion monitoring control algorithm. A performance evaluation was conducted with 60-insertions and fluorescein dye injection tests to show how accurately the system can guide the needle and lock to the target depth. The evaluation tests show our system can guide the injection needle into the desired depth with 4.12 um average deviation error while injecting 50 nl of fluorescein dye.

Real-time visualization of ultrasound-guided retrobulbar blockade: an imaging study.

PubMed

Luyet, C; Eichenberger, U; Moriggl, B; Remonda, L; Greif, R

2008-12-01

Retrobulbar anaesthesia allows eye surgery in awake patients. Severe complications of the blind techniques are reported. Ultrasound-guided needle introduction and direct visualization of the spread of local anaesthetic may improve quality and safety of retrobulbar anaesthesia. Therefore, we developed a new ultrasound-guided technique using human cadavers. In total, 20 blocks on both sides in 10 embalmed human cadavers were performed. Using a small curved array transducer and a long-axis approach, a 22 G short bevel needle was introduced under ultrasound guidance lateral and caudal of the eyeball until the needle tip was seen 2 mm away from the optic nerve. At this point, 2 ml of contrast dye as a substitute for local anaesthetic was injected. Immediately after the injection, the spread of the contrast dye was documented by means of CT scans performed in each cadaver. The CT scans showed the distribution of the contrast dye in the muscle cone and behind the posterior sclera in all but one case. No contrast dye was found inside the optic nerve or inside the eyeball. In one case, there could be an additional trace of contrast dye behind the orbita. Our new ultrasound-guided technique has the potential to improve safety and efficacy of the procedure by direct visualization of the needle placement and the distribution of the injected fluid. Furthermore, the precise injection near the optic nerve could lead to a reduction of the amount of the local anaesthetic needed with fewer related complications.

Double needle technique: an alternative method for performing difficult sacroiliac joint injections.

PubMed

Gupta, Sanjeeva

2011-01-01

The sacroiliac joint (SIJ) is a common source of low back pain. The most appropriate method of confirming SIJ pain is to inject local anesthesia into the joint to find out if the pain decreases. Unfortunately, although the SIJ is a large joint, it can be difficult to enter due to the complex nature of the joint and variations in anatomy. In my experience a double needle technique for sacroiliac joint injection can increase the chances of accurate injection into the SIJ in difficult cases. After obtaining appropriate fluoroscopic images, the tip of the needle is advanced into the SIJ. Once the tip of the needle is correctly placed, its position is checked under continuous fluoroscopy while moving the C-arm in the right and left oblique directions (dynamic fluoroscopy). On dynamic fluoroscopy the tip of the needle should remain within the joint line and not appear to be on the bone. If the tip of the needle appears to be on the bone a new joint line will need to be identified (the most translucent area through the joint) by dynamic fluoroscopy and another needle advanced into the newly identified joint line. Dynamic fluoroscopy is repeated again to confirm that the tip of the second needle remains within the joint line. Once both needles are in place contrast dye is injected through the needle that is most likely to be in the SIJ. If the contrast dye spread is not satisfactory then it is injected through the other needle. I have used this technique in 10 patients and found it very helpful in accurately performing SIJ injection which can at times be challenging.

"Spider"-shaped porphyrins with conjugated pyridyl anchoring groups as efficient sensitizers for dye-sensitized solar cells.

PubMed

Stangel, Christina; Bagaki, Anthi; Angaridis, Panagiotis A; Charalambidis, Georgios; Sharma, Ganesh D; Coutsolelos, Athanasios G

2014-11-17

Two novel "spider-shaped" porphyrins, meso-tetraaryl-substituted 1PV-Por and zinc-metalated 1PV-Zn-Por, bearing four oligo(p-phenylenevinylene) (oPPV) pyridyl groups with long dodecyloxy chains on the phenyl groups, have been synthesized. The presence of four pyridyl groups in both porphyrins, which allow them to act as anchoring groups upon coordination to various Lewis acid sites, the conjugated oPPV bridges, which offer the possibility of electronic communication between the porphyrin core and the pyridyl groups, and the dodecyloxy groups, which offer the advantage of high solubility in a variety of organic solvents of different polarities and could prevent porphyrin aggregation, renders porphyrins 1PV-Por and 1PV-Zn-Por very promising sensitizers for dye-sensitized solar cells (DSSCs). Photophysical measurements, together with electrochemistry experiments and density functional theory calculations, suggest that both porphyrins have frontier molecular orbital energy levels that favor electron injection and dye regeneration in DSSCs. Solar cells sensitized by 1PV-Por and 1PV-Zn-Por were fabricated, and it was found that they show power conversion efficiencies (PCEs) of 3.28 and 5.12%, respectively. Photovoltaic measurements (J-V curves) together with incident photon-to-electron conversion efficiency spectra of the two cells reveal that the higher PCE value of the DSSC based on 1PV-Zn-Por is ascribed to higher short-circuit current (Jsc), open-circuit voltage (Voc), and dye loading values. Emission spectra and electrochemistry experiments suggest a greater driving force for injection of the photogenerated electrons into the TiO2 conduction band for 1PV-Zn-Por rather than its free-base analogue. Furthermore, electrochemical impedance spectroscopy measurements prove that the utilization of 1PV-Zn-Por as a sensitizer offers a high charge recombination resistance and, therefore, leads to a longer electron lifetime.

Fragile X Mental Retardation Protein Restricts Small Dye Iontophoresis Entry into Central Neurons.

PubMed

Kennedy, Tyler; Broadie, Kendal

2017-10-11

Fragile X mental retardation protein (FMRP) loss causes Fragile X syndrome (FXS), a major disorder characterized by autism, intellectual disability, hyperactivity, and seizures. FMRP is both an RNA- and channel-binding regulator, with critical roles in neural circuit formation and function. However, it remains unclear how these FMRP activities relate to each other and how dysfunction in their absence underlies FXS neurological symptoms. In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpected and highly robust neuronal dye iontophoresis phenotype in the well mapped giant fiber (GF) circuit. Controlled dye injection into the GF interneuron results in a dramatic increase in dye uptake in neurons lacking FMRP. Transgenic wild-type FMRP reintroduction rescues the mutant defect, demonstrating a specific FMRP requirement. This phenotype affects only small dyes, but is independent of dye charge polarity. Surprisingly, the elevated dye iontophoresis persists in shaking B mutants that eliminate gap junctions and dye coupling among GF circuit neurons. We therefore used a wide range of manipulations to investigate the dye uptake defect, including timed injection series, pharmacology and ion replacement, and optogenetic activity studies. The results show that FMRP strongly limits the rate of dye entry via a cytosolic mechanism. This study reveals an unexpected new phenotype in a physical property of central neurons lacking FMRP that could underlie aspects of FXS disruption of neural function. SIGNIFICANCE STATEMENT FXS is a leading heritable cause of intellectual disability and autism spectrum disorders. Although researchers established the causal link with FMRP loss >;25 years ago, studies continue to reveal diverse FMRP functions. The Drosophila FXS model is key to discovering new FMRP roles, because of its genetic malleability and individually identified neuron maps. Taking advantage of a well characterized Drosophila neural circuit, we discovered that neurons lacking FMRP take up dramatically more current-injected small dye. After examining many neuronal properties, we determined that this dye defect is cytoplasmic and occurs due to a highly elevated dye iontophoresis rate. We also report several new factors affecting neuron dye uptake. Understanding how FMRP regulates iontophoresis should reveal new molecular factors underpinning FXS dysfunction. Copyright © 2017 the authors 0270-6474/17/379844-15$15.00/0.

Intraoperative sentinel node identification in early stage cervical cancer using a combination of radiolabeled albumin injection and isosulfan blue dye injection.

PubMed

Martínez-Palones, José M; Gil-Moreno, Antonio; Pérez-Benavente, María A; Roca, Isabel; Xercavins, Jordi

2004-03-01

We investigated the feasibility of sentinel lymph node identification using radioisotopic lymphatic mapping with technetium-99m-labeled human serum albumin and isosulfan blue dye injection in patients undergoing radical hysterectomy with pelvic lymphadenectomy for treatment of early cervical cancer. Between September 2000 and October 2002, 25 patients with cervical cancer FIGO stage I (n=24) or stage II (n=1) underwent sentinel lymph node detection with preoperative lymphoscintigraphy (technetium-99m colloid albumin injection around the tumor) and intraoperative lymphatic mapping with blue dye and a handheld or laparoscopic gamma probe. Complete pelvic or paraaortic lymphadenectomy was performed in all cases by open surgery or laparoscopic surgery. In 23 evaluable patients, a total of 51 sentinel lymph nodes were detected by lymphoscintigraphy (mean 2.21 nodes per patient). Intraoperatively, 61 sentinel lymph nodes were identified, with a mean of 2.52 nodes per patient by gamma probe and a mean of 1.94 nodes per patient after isosulfan blue injection. Forty percent of sentinel nodes were found in the interiliac region and 25% in the external iliac area. Microscopic nodal metastases (four nodes) were confirmed in 12% of cases. All these lymph nodes were previously detected as sentinel lymph nodes. The remaining 419 nodes after pelvic lymphadenectomy were histologically negative. Sentinel lymph node identification with technetium-99m-labeled nanocolloid combined with blue dye injection is feasible and showed a 100% negative predictive value, and potentially identified women in whom lymph node dissection can be avoided.

Analysis of ground-water flow in the Madison aquifer using fluorescent dyes injected in Spring Creek and Rapid Creek near Rapid City, South Dakota, 2003-04

USGS Publications Warehouse

Putnam, Larry D.; Long, Andrew J.

2007-01-01

The Madison aquifer, which contains fractures and solution openings in the Madison Limestone, is used extensively for water supplies for the city of Rapid City and other suburban communities in the Rapid City, S. Dak., area. The 48 square-mile study area includes the west-central and southwest parts of Rapid City and the outcrops of the Madison Limestone extending from south of Spring Creek to north of Rapid Creek. Recharge to the Madison Limestone occurs when streams lose flow as they cross the outcrop. The maximum net loss rate for Spring and Rapid Creek loss zones are 21 and 10 cubic feet per second (ft3/s), respectively. During 2003 and 2004, fluorescent dyes were injected in the Spring and Rapid Creek loss zones to estimate approximate locations of preferential flow paths in the Madison aquifer and to measure the response and transit times at wells and springs. Four injections of about 2 kilograms of fluorescein dye were made in the Spring Creek loss zone during 2003 (sites S1, S2, and S3) and 2004 (site S4). Injection at site S1 was made in streamflow just upstream from the loss zone over a 12-hour period when streamflow was about equal to the maximum loss rate. Injections at sites S2, S3, and S4 were made in specific swallow holes located in the Spring Creek loss zone. Injection at site R1 in 2004 of 3.5 kilograms of Rhodamine WT dye was made in streamflow just upstream from the Rapid Creek loss zone over about a 28-hour period. Selected combinations of 27 wells, 6 springs, and 3 stream sites were monitored with discrete samples following the injections. For injections at sites S1-S3, when Spring Creek streamflow was greater than or equal to 20 ft3/s, fluorescein was detected in samples from five wells that were located as much as about 2 miles from the loss zone. Time to first arrival (injection at site S1) ranged from less than 1 to less than 10 days. The maximum fluorescein concentration (injection at site S1) of 120 micrograms per liter (ug/L) at well CO, which is located adjacent to the loss zone, was similar to the concentration in the stream. Fluorescein arrived at well NON (injection at site S1), which is located about 2 miles northeast of the loss zone, within about 1.6 days, and the maximum concentration was 44 ug/L. For injection at site S4, when streamflow was about 12 ft3/s, fluorescein was detected in samples from six wells and time to first arrival ranged from 0.2 to 16 days. Following injection at site S4 in 2004, the length of time that dye remained in the capture zone of well NON, which is located approximately 2 miles from the loss zone, was almost an order of magnitude greater than in 2003. For injection at site R1, Rhodamine WT was detected at well DRU and spring TI-SP with time to first arrival of about 0.5 and 1.1 days and maximum concentrations of 6.2 and 0.91 ug/L, respectively. Well DRU and spring TI-SP are located near the center of the Rapid Creek loss zone where the creek has a large meander. Measurable concentrations were observed for spring TI-SP as many as 109 days after the dye injection. The direction of a conduit flow path in the Spring Creek area was to the northeast with ground-water velocities that ranged from 770 to 6,500 feet per day. In the Rapid Creek loss zone, a conduit flow path east of the loss zone was not evident from the dye injection.

Function of CN group in organic sensitizers: The first principle study.

PubMed

Liu, Yun; Shao, Di; Bai, Xiaohui; Yang, Zhenqing; Lin, Chundan; Shao, Changjin

2017-05-15

The cyano group (CN) of the acceptor in organic sensitizers plays an important role for highly efficient dye-sensitized solar cells. In this paper, three 5, 6-difluoro-2,1,3-benzothiadiazole (DFBTD) organic molecules with different number of CN units, named ME15, ME16 and ME17, were investigated by the density functional theory (DFT) and time-dependent DFT (TDDFT). We analyzed the CNs effects on the electronic structures, optical properties, adsorption modes and electron transfer and injection. The result shows that ME17 has the largest maximum absorption wavelength (λ max ) among these new designed dyes due to the strong electron withdrawing ability of two CNs. In addition, CN greatly influence the adsorption modes of dye/TiO 2 and electron injection mechanism. ME16 with one CN also has good optical absorption properties and its acceptor has the strongest coupling strength with the TiO 2 semiconductor which is favorable for electron transfer and injection. Thus, we believe that the number of CN groups in acceptor should be moderate and one CN in D-A-π-A structure dyes may be the more appropriate focusing on the light harvesting ability, electron transfer and electron injection. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of indocyanine green and sodium fluorescein for anterior segment angiography in ophthalmologically normal cats.

PubMed

Pirie, Chris G; Alario, Anthony

2015-10-01

To assess and compare results of anterior segment angiography of ophthalmologically normal cats following IV injection with indocyanine green and sodium fluorescein dyes. 10 client-owned cats. Anterior segment angiography was performed in anesthetized cats following administration of 0.25% indocyanine green (1.0 mg/kg, IV) or 10% sodium fluorescein (20 mg/kg, IV) solution. All cats received both treatments. Imaging (1 eye/cat) was performed with a full-spectrum digital single-lens reflex camera equipped with an adaptor (1 image/s for 30 seconds) immediately following IV dye injection and 1, 2, 3, 4, and 5 minutes after injection. Onset and duration of arterial, capillary, and venous phases of iris vasculature were identified and compared statistically between treatments. Degree of iridal pigmentation, leakage of dye from iris vasculature, and image quality were subjectively assessed. No differences were found in onset or duration of vascular phases between treatments. Visibility of the iris vasculature was not impaired by poor or moderate iridal pigmentation with either method. Indocyanine green provided subjectively better vascular detail and image contrast than sodium fluorescein. No vascular dye leakage was observed following indocyanine green administration. Leakage of dye from blood vessels in the stroma (in 10 cats) and presence of dye in the anterior chamber (in 5 cats) were detected after sodium fluorescein administration. Images obtained with either fluorescent dye were considered to be of diagnostic quality. Lack of leakage following indocyanine green administration suggested this treatment may have better diagnostic utility for anterior segment angiography. The photographic equipment used provided a cost-effective alternative to existing imaging systems.

Measurement of Human Blood and Plasma Volumes

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Szalkay, H. G. H.

1987-01-01

Report reviews techniques for measuring blood-plasma volume in humans. Common technique of using radioactive iodine isotope to label plasma albumin involves unwarranted risks from low-level radiation. Report emphasizes techniques using Evans-blue-dye (T-1824) labeling of albumin, hematocrit or hemoglobin/hematocrit measurements, or blood densitometry. In Evans-blue-dye technique, plasma volume determined from decrease in dye concentration occurring after small amount of dye solution injected into circulatory system. Subjection of Evans blue dye to test for carcinogenicity gave negative results.

Ultrafast Recombination Dynamics in Dye-Sensitized SnO2/TiO2 Core/Shell Films.

PubMed

Gish, Melissa K; Lapides, Alexander M; Brennaman, M Kyle; Templeton, Joseph L; Meyer, Thomas J; Papanikolas, John M

2016-12-15

Interfacial dynamics are investigated in SnO 2 /TiO 2 core/shell films derivatized with a Ru(II)-polypyridyl chromophore ([Ru II (bpy) 2 (4,4'-(PO 3 H 2 ) 2 bpy)] 2+ , RuP) using transient absorption methods. Electron injection from the chromophore into the TiO 2 shell occurs within a few picoseconds after photoexcitation. Loss of the oxidized dye through recombination occurs across time scales spanning 10 orders of magnitude. The majority (60%) of charge recombination events occur shortly after injection (τ = 220 ps), while a small fraction (≤20%) of the oxidized chromophores persists for milliseconds. The lifetime of long-lived charge-separated states (CSS) depends exponentially on shell thickness, suggesting that the injected electrons reside in the SnO 2 core and must tunnel through the TiO 2 shell to recombine with oxidized dyes. While the core/shell architecture extends the lifetime in a small fraction of the CSS, making water oxidation possible, the subnanosecond recombination process has profound implications for the overall efficiencies of dye-sensitized photoelectrosynthesis cells (DSPECs).

Effects of tissue-preparation-induced callose synthesis on estimates of plasmodesma size exclusion limits.

PubMed

Radford, J E; White, R G

2001-01-01

Plasmodesmata are often characterised by their size exclusion limit (SEL), which is the molecular weight of the largest dye, introduced by microinjection, that will move from cell to cell. In this study, we investigated whether commonly used techniques for isolation and manipulation of tissues, and microinjection of fluorescent dyes, affected the SEL, and whether any such effects could be ameliorated by inhibiting callose deposition. We examined young root epidermal cells of Arabidopsis thaliana and staminal hair cells of Tradescantia virginiana, two tissues often used in experiments on symplastic transport. Transport in root tips dissected from the main plant body and in stamen hairs removed from the base of the stamen filament was compared with transport in undissected roots and stamen hairs attached to the base of the filament, respectively. Tissues were microinjected with fluorescent dyes (457 Da to > 3 kDa) with or without prior incubation in the callose deposition inhibitors 2-deoxy-D-glucose or aniline blue fluorochrome. In both tissues, dissection reduced the SEL, which was largely prevented by prior incubation in 2-deoxy-D-glucose but not by incubation in aniline blue fluorochrome. Thus, standard methods for tissue preparation can cause sufficient callose deposition to reduce cell-to-cell transport, and this needs to be considered in studies employing microinjection. Introduction of the dyes by pressure injection rather than iontophoresis decreased the SEL in A. thaliana but increased it in T. virginiana, showing that these two injection techniques do not necessarily give identical results and that plasmodesmata in different tissues may respond differently to similar experimental procedures.

In vivo biocompatibility of a new cyanine dye for ILM peeling

PubMed Central

Thaler, S; Haritoglou, C; Schuettauf, F; Choragiewicz, T; May, C A; Gekeler, F; Fischer, M D; Langhals, H; Schatz, A

2015-01-01

Purpose To investigate the biocompatibility of the new cyanine dye: 3,3′-Di-(4-sulfobutyl)-1,1,1′,1′-tetramethyl-di-1H-benz[e]indocarbocyanine (DSS) as a vital dye for intraocular application in an in vivo rat model and to evaluate the effects of this dye on retinal structure and function. Methods DSS at a concentration of 0.5% was applied via intravitreal injections to adult Brown Norway rats with BSS serving as a control. Retinal toxicity was assessed 7 days later by means of retinal ganglion cell (RGC) counts, light microscopy, optical coherence tomography (OCT), and electroretinography (ERG). Results No significant decrease in RGC numbers was observed. No structural changes of the central retina were observed either in vivo (OCT) or under light microscopy. ERGs detected a temporary reduction of retinal function 7 days after injection; this was no longer evident 14 days after injection. Conclusions DSS showed good biocompatibility in a well-established experimental in vivo setting and may be usable for intraocular surgery as an alternative to other cyanine dyes. In contrast to indocyanine green, it additionally offers fluorescence in the visual spectrum. Further studies with other animal models are needed before translation into clinical application. PMID:25523205

Electromagnetic Navigation Bronchoscopy-directed Pleural Tattoo to Aid Surgical Resection of Peripheral Pulmonary Lesions.

PubMed

Tay, Jun H; Wallbridge, Peter D; Larobina, Marco; Russell, Prudence A; Irving, Louis B; Steinfort, Daniel P

2016-07-01

Limited (wedge) resection of pulmonary lesions is frequently performed as a diagnostic/therapeutic procedure. Some lesions may be difficult to locate thoracoscopically with conversion to open thoracotomy or incomplete resection being potential limitations to this approach. Multiple methods have been described to aid video-assisted thoracoscopic surgical (VATS) wedge resection of pulmonary nodules, including hookwire localization, percutaneous tattoo, or intraoperative ultrasound. We report on our experience using electromagnetic navigation bronchoscopic dye marking of small subpleural lesions to aid VATS wedge resection. A retrospective cohort study of consecutive patients undergoing VATS wedge resection of peripheral lesions. Preoperative bronchoscopy with electromagnetic navigation was utilized to guide a 25 G needle to within/adjacent to the target lesion with injection of 1 mL of methylene blue or indigo carmine under fluoroscopic vision. Six patients underwent bronchoscopic marking of peripheral pulmonary lesions, navigation deemed successful in all patients, with no procedural complications. Surgery was performed within 24 hours of bronchoscopic marking. Pleural staining by dye was visible thoracoscopically in all 6 lesions either adjacent to or overlying the lesion. All lesions were fully excised with wedge resection. Pathologic examination confirmed accuracy of dye staining. Electromagnetic navigation bronchoscopic dye marking of peripheral lesions is feasible, without complications commonly associated with percutaneous marking procedures. Further experience is required but early findings suggest that this method may have utility in aiding minimally invasive resection of small subpleural lesions.

[Anaphylactic shock due to patent blue: four case report and review of literature].

PubMed

Lucas, N; Interne, S Benay; Laine, P; Nicolie, B; Fondrinier, E

2010-04-01

Description of four cases of anaphylactic shock with blue dye injection (bleu patenté V Guerbet 2.5%) during sentinel node biopsy for breast cancer. Women with breast carcinoma and combined approach with radioactive tracer and blue patent injection. Four cases were observed, which means an incidence of 0.57%. We report one case of grade II anaphylactic reaction and three cases of grade III requiring active reanimation and adrenaline perfusion. One patient developed a pulmonary embolism during the postoperative period, but no death was observed. We find an incidence of 1.06% of allergy but only 0.25% of anaphylactic shock (grade III). These rare but serious cases must weigh up the benefits and risks of using blue dye. We suggest using blue dye injection only in case of radioisotope detection failure. Of course, this approach must be evaluated. (c) 2009 Elsevier Masson SAS. All rights reserved.

Inferring glacial flow pathways with DNA-labelled microparticle tracers at the Wolverine Glacier in Alaska

NASA Astrophysics Data System (ADS)

McNew, Coy; Dahlke, Helen; O'Neel, Shad; McLaughlin, Seanna

2017-04-01

Though recent advances have been made in the understanding of glacial hydrologic pathways, accurate predictions and descriptions of glacial hydrologic processes remain a challenge. The most common method to investigate subglacial pathways tends to be dye tracing. Due to the limited number of unique dye tracers, the photodegradability of some, and the typically long breakthrough times associated with such pathways, dye tracing experiments tend to be restricted to only a few injections, and therefore the contribution of only a few pathways can be investigated at a time. Five uniquely DNA-labelled microparticle tracers were injected in five different locations throughout the Wolverine Glacier ablation zone, one of two "benchmark glaciers" in Alaska and the subject of long term study by the United States Geological Survey. Stream water was sampled several hundred meters downstream at regular intervals and later analyzed for the presence of each tracer. Since each tracer was tagged with a unique sequence of DNA, the contribution of each to the total outflow can be quantified independently. Preliminary results indicate relatively short transit times, suggesting that the ablation zone is characterized by a high-volume (low pressure) subglacial hydrologic network (i.e. conduits). Here we present the results of the study, the challenges faced, and a discussion on the potential of the DNA-labelled microtracer technology.

The impact of previous para-areolar incision in the upper outer quadrant of the breast on the localization of the sentinel lymph node in a canine model

PubMed Central

Vasques, Paulo Henrique Diógenes; Pinheiro, Luiz Gonzaga Porto; de Meneses e Silva, João Marcos; de Moura Torres-de-Melo, José Ricardo; Pinheiro, Karine Bessa Porto; Rocha, João Ivo Xavier

2011-01-01

OBJECTIVES: This paper discusses the influence of a para-areolar incision in the upper outer quadrant of the breast on the location of the sentinel lymph node in a canine model. METHODS: The sentinel lymph node was marked with technetium-99, which was injected into the subareolar skin of the cranial breast. After the marker had migrated to the axilla, an arcuate para-areolar incision was performed 2 cm from the nipple in the upper outer quadrant. Patent blue dye was then injected above the upper border of the incision. At the marked site, an axillary incision was made, and the sentinel lymph node was identified by gamma probe and/or by direct visualization of the dye. The agreement between the two injection sites and the two sentinel lymph node identification methods was determined. Our sample group consisted of 40 cranial breasts of 23 adult females of the species Canis familiaris. The data were analyzed by using the McNemar test and by determining the kappa agreement coefficient. RESULT: Our findings showed that in 95% of the breasts, the sentinel lymph node was identified by the injection of technetium-99 m into the subareolar region, and in 82% of the cases, the sentinel lymph node was identified by the injection of patent blue dye above the upper border of the incision. The methods agreed 82% of the time. CONCLUSIONS: Previous para-areolar incisions in the upper outer quadrant did not interfere significantly with the biopsy when the dye was injected above the upper border of the incision. PMID:21915493

Two-color Dye-swap DNA Microarray approach toward confident gene expression profiling in PMCAO mouse model for ischemia-related and PACAP38-influenced genes

PubMed Central

Hori, Motohide; Shibato, Junko; Nakamachi, Tomoya; Rakwal, Randeep; Ogawa, Tetsuo; Shioda, Seiji; Numazawa, Satoshi

2015-01-01

Toward twin goals of identifying molecular factors in brain injured by ischemic stroke, and the effects of neuropeptide pituitary adenylate-cyclase activating polypeptide (PACAP) on the ischemic brain, we have established the permanent middle cerebral artery occlusion (PMCAO) mouse model and utilized the Agilent mouse whole genome 4 × 44 K DNA chip. PACAP38 (1 pmol) injection was given intracerebroventrically in comparison to a control saline (0.9% NaCl) injection, to screen genes responsive to PACAP38. Two sets of tissues were prepared, whole hemispheres (ischemic and non-ischemic) and infract core and penumbra regions at 6 and 24 h. In this study, we have detailed the experimental design and protocol used therein and explained the quality controls for the use of total RNA in the downstream DNA microarray experiment utilizing a two-color dye-swap approach for stringent and confident gene identification published in a series of papers by Hori and coworkers (Hori et al., 2012–2015). PMID:26484166

Administration of novel dyes for intraocular surgery: an in vivo toxicity animal study.

PubMed

Schuettauf, Frank; Haritoglou, Christos; May, Christian A; Rejdak, Robert; Mankowska, Anna; Freyer, Wolfgang; Eibl, Kirsten; Zrenner, Eberhart; Kampik, Anselm; Thaler, Sebastian

2006-08-01

To investigate the effect of intravitreal injections of new vital dyes on the retina, the retinal pigment epithelium (RPE) and the choroid in an in vivo rat model. Rats were injected intravitreally with four dyes: light-green SF yellowish (LGSF), copper(II)phthalocyanine-tetrasulfonic acid (E68), bromphenol blue (BPB), and Chicago blue (CB) dissolved in physiologic saline solution (PSS) at concentrations of 0.5% and 0.02%. PSS served as the control. Additional animals were treated with single injections of 0.5%, 0.02%, 0.002%, and 0.0002% ICG or 0.002% E68 into one eye. Adverse effects on anterior and posterior segments were evaluated by slit lamp biomicroscopy and ophthalmoscopy. Retinal toxicity was assessed by histology and retinal ganglion cell (RGC) quantification 7 days after dye administration. Eyes treated with 0.5% E68, 0.5% ICG, or 0.5% CB showed discrete staining of both cornea and lens not seen at lower concentrations or with other dyes. Histology revealed dose-dependent reactions after E68 administration. ICG 0.5% induced significant thinning of inner retinal layers compared with PSS. ICG 0.02% caused focal degenerative changes of the outer retina in three of seven eyes, whereas 0.002% and 0.0002% ICG did not. CB led to heterogeneous morphologic alterations. BPB- or LGSF-treated eyes showed normal retinal morphology. ICG at all tested concentrations induced significant RGC loss, as did E68 at 0.5% but not at lower concentrations. BPB or LGSF produced no significantly detectable toxic effects on the retina in vivo. The safety of these new dyes must be established in other models and/or in preclinical studies before the clinical use of any of these dyes.

Improvement of photovoltaic performance by substituent effect of donor and acceptor structure of TPA-based dye-sensitized solar cells.

PubMed

Inostroza, Natalia; Mendizabal, Fernando; Arratia-Pérez, Ramiro; Orellana, Carlos; Linares-Flores, Cristian

2016-01-01

We report a computational study of a series of organic dyes built with triphenylamine (TPA) as an electron donor group. We designed a set of six dyes called (TPA-n, where n = 0-5). In order to enhance the electron-injection process, the electron-donor effect of some specific substituent was studied. Thus, we gave insights into the rational design of organic TPA-based chromophores for use in dye-sensitized solar cells (DSSCs). In addition, we report the HOMO, LUMO, the calculated excited state oxidized potential E(dye*)(eV) and the free energy change for electron-injection ΔGinject(eV), and the UV-visible absorption bands for TPA-n dyes by a time-dependent density functional theory (TDDFT) procedure at the B3LYP and CAM-B3LYP levels with solvent effect. The results demonstrate that the introduction of the electron-acceptor groups produces an intramolecular charge transfer showing a shift of the absorption wavelengths of TPA-n under studies. Graphical Abstract Several organic dyes TPA-n with different donors and acceptors are modeled. A strong conjugation acrros the donor and anchoring groips (TPA-n) bas been studied. Candidate TPA-3 shows a promising results.

Opto-injection into single living cells by femtosecond near-infrared laser

NASA Astrophysics Data System (ADS)

Peng, Cheng

This dissertation presents a novel technique to deliver membrane impermeable molecules into single living cells with the assistance of femtosecond (fs) near-infrared (NIR) laser pulses. This approach merges ultrafast laser technology with key biological, biomedical, and medical applications, such as gene transfection, gene therapy and drug delivery. This technique promises several major advantages, namely, very high transfection efficiency, high cell survival rate (≈100%) and fully preserved cell viabilities. It is also a promising method to deliver molecules into cells that are difficult or even completely resistant to established physical methods, such as microinjection by glass pipettes, electroporation, and biolistics. In this work, the system for fs NIR opto-injection was designed and built. Successful fs NIR opto-injection has been performed on several cell systems including single mammalian cells (bovine aortic endothelial cells), marine animal eggs (Spisula solidissima oocytes), and human cancer cells (fibrosarcoma HT1080) cultured in a tissue-like environment. The connections between laser parameters and cell responses were explored through further experiments and in-depth analyses, especially the relationship between dye uptake rate and incident laser intensity, and the relationship between pore size created on cell membranes and incident laser intensity. Dye uptake rate of the target cells was observed to depend on incident laser intensity. Pore size was found dependent on incident laser intensity. The conclusion was made that laser-induced breakdown and plasma-induced ablation in cell membrane are the physical principles that govern the process of fs NIR opto-injection.

Ground and excited state properties of high performance anthocyanidin dyes-sensitized solar cells in the basic solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prima, Eka Cahya; Computational Material Design and Quantum Engineering Laboratory, Engineering Physics, Institut Teknologi Bandung; International Program on Science Education, Universitas Pendidikan Indonesia

2015-09-30

The aglycones of anthocyanidin dyes were previously reported to form carbinol pseudobase, cis-chalcone, and trans-chalcone due to the basic levels. The further investigations of ground and excited state properties of the dyes were characterized using density functional theory with PCM(UFF)/B3LYP/6-31+G(d,p) level in the basic solutions. However, to the best of our knowledge, the theoretical investigation of their potential photosensitizers has never been reported before. In this paper, the theoretical photovoltaic properties sensitized by dyes have been successfully investigated including the electron injections, the ground and excited state oxidation potentials, the estimated open circuit voltages, and the light harvesting efficiencies. Themore » results prove that the electronic properties represented by dyes’ LUMO-HOMO levels will affect to the photovoltaic performances. Cis-chalcone dye is the best anthocyanidin aglycone dye with the electron injection spontaneity of −1.208 eV, the theoretical open circuit voltage of 1.781 V, and light harvesting efficiency of 56.55% due to the best HOMO-LUMO levels. Moreover, the ethanol solvent slightly contributes to the better cell performance than the water solvent dye because of the better oxidation potential stabilization in the ground state as well as in the excited state. These results are in good agreement with the known experimental report that the aglycones of anthocyanidin dyes in basic solvent are the high potential photosensitizers for dye-sensitized solar cell.« less

Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

PubMed

Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

2016-06-01

We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency.

The effect of different π-bridge configuration on bi-anchored triphenylamine and phenyl modified triphenylamine based dyes for dye sensitized solar cell (DSSC) application: A theoretical approach.

PubMed

Pounraj, P; Mohankumar, V; Pandian, M Senthil; Ramasamy, P

2018-01-01

Twenty eight bi-anchored triphenylamine (TH-1 to TH-14) and phenyl modified triphenylamine (PH-TH-1 to PH-TH-14) based metal free organic dyes are designed for DSSC application. The electronic effect of different π-bridge configurations in donor-π-bridge-acceptor (D-π-A) 2 structure was theoretically simulated and verified using density functional theory (DFT) and time dependent density functional theory (TD-DFT). The triphenylamine and phenyl modified triphenylamine groups are used as donor and cyanoacrylic acid group is used as acceptor. Thiophene and cyanovinyl groups are used as π-bridge. The ground state molecular structure was optimized by density functional theory and the electronic absorption spectra were calculated by time dependent density functional theory. The light harvesting efficiency (LHE), dye regeneration energy (ΔG reg ) and electron injection energy (ΔG inject ) are determined by computational examination. It is observed that, when the number of π-bridge increases, the band gap of the dye decreases. Also the absorption maximum and molar extinction coefficient of the dyes are increased. Theoretical result shows that the thiophene-cyanovinyl and thiophene-thiophene-cyanovinyl-cyanovinyl configurations give broader and red shifted absorption spectrum compared to other configurations. Also the results of phenyl modified triphenylamine (PH-TH) dyes clearly show better absorption and dye regeneration energy compared to TH dyes. Copyright © 2017 Elsevier Inc. All rights reserved.

Wide-field in vivo neocortical calcium dye imaging using a convection-enhanced loading technique combined with simultaneous multiwavelength imaging of voltage-sensitive dyes and hemodynamic signals

PubMed Central

Ma, Hongtao; Harris, Samuel; Rahmani, Redi; Lacefield, Clay O.; Zhao, Mingrui; Daniel, Andy G. S.; Zhou, Zhiping; Bruno, Randy M.; Berwick, Jason; Schwartz, Theodore H.

2014-01-01

Abstract. In vivo calcium imaging is an incredibly powerful technique that provides simultaneous information on fast neuronal events, such as action potentials and subthreshold synaptic activity, as well as slower events that occur in the glia and surrounding neuropil. Bulk-loading methods that involve multiple injections can be used for single-cell as well as wide-field imaging studies. However, multiple injections result in inhomogeneous loading as well as multiple sites of potential cortical injury. We used convection-enhanced delivery to create smooth, continuous loading of a large area of the cortical surface through a solitary injection site and demonstrated the efficacy of the technique using confocal microscopy imaging of single cells and physiological responses to single-trial events of spontaneous activity, somatosensory-evoked potentials, and epileptiform events. Combinations of calcium imaging with voltage-sensitive dye and intrinsic signal imaging demonstrate the utility of this technique in neurovascular coupling investigations. Convection-enhanced loading of calcium dyes may be a useful technique to advance the study of cortical processing when widespread loading of a wide-field imaging is required. PMID:25525611

Wide-field in vivo neocortical calcium dye imaging using a convection-enhanced loading technique combined with simultaneous multiwavelength imaging of voltage-sensitive dyes and hemodynamic signals.

PubMed

Ma, Hongtao; Harris, Samuel; Rahmani, Redi; Lacefield, Clay O; Zhao, Mingrui; Daniel, Andy G S; Zhou, Zhiping; Bruno, Randy M; Berwick, Jason; Schwartz, Theodore H

2014-07-24

In vivo calcium imaging is an incredibly powerful technique that provides simultaneous information on fast neuronal events, such as action potentials and subthreshold synaptic activity, as well as slower events that occur in the glia and surrounding neuropil. Bulk-loading methods that involve multiple injections can be used for single-cell as well as wide-field imaging studies. However, multiple injections result in inhomogeneous loading as well as multiple sites of potential cortical injury. We used convection-enhanced delivery to create smooth, continuous loading of a large area of the cortical surface through a solitary injection site and demonstrated the efficacy of the technique using confocal microscopy imaging of single cells and physiological responses to single-trial events of spontaneous activity, somatosensory-evoked potentials, and epileptiform events. Combinations of calcium imaging with voltage-sensitive dye and intrinsic signal imaging demonstrate the utility of this technique in neurovascular coupling investigations. Convection-enhanced loading of calcium dyes may be a useful technique to advance the study of cortical processing when widespread loading of a wide-field imaging is required.

Ultrafast electron and hole transfer dynamics of a solar cell dye containing hole acceptors on mesoporous TiO2 and Al2O3.

PubMed

Scholz, Mirko; Flender, Oliver; Boschloo, Gerrit; Oum, Kawon; Lenzer, Thomas

2017-03-08

The stability of dye cations against recombination with conduction band electrons in mesoporous TiO 2 electrodes is a key property for improving light harvesting in dye-sensitised solar cells. Using ultrafast transient broadband absorption spectroscopy, we monitor efficient intramolecular hole transfer in the solar cell dye E6 having two peripheral triarylamine acceptors. After photoexcitation, two hole transfer mechanisms are identified: a concerted mechanism for electron injection and hole transfer (2.4 ps) and a sequential mechanism with time constants of 3.9 ps and 30 ps. This way the dye retards unwanted recombination with a TiO 2 conduction band electron by quickly moving the hole further away from the surface. Contact of the E6/TiO 2 surface with the solvent acetonitrile has almost no influence on the electron injection and hole transfer kinetics. Fast hole transfer (2.8 ps) is also observed on a "non-injecting" Al 2 O 3 surface generating a radical cation-radical anion species with a lifetime of 530 ps. The findings confirm the good intramolecular hole transfer properties of this dye on both thin films. In contrast, intramolecular hole transfer does not occur in the mid-polar organic solvent methyl acetate. This is confirmed by TDDFT calculations suggesting a polarity-induced reduction of the driving force for hole transfer. In methyl acetate, only the relaxation of the initially photoexcited core chromophore is observed including solvent relaxation processes of the electronically excited state S 1 /ICT.

Detection of light-induced changes of intracellular ionized calcium concentration in Limulus ventral photoreceptors using arsenazo III

PubMed Central

Brown, J. E.; Brown, P. K.; Pinto, L. H.

1977-01-01

1. The metallochromic indicator dye, arsenazo III, was injected intracellularly into Limulus ventral photoreceptor cells to concentrations greater than 1 mM. 2. The absorption spectrum (450-750 nm) of the dye in single dark-adapted cells was measured by a scanning microspectrophotometer. When a cell was light-adapted, the absorption of the dye changed; the difference spectrum had two maxima at about 610 and 660 nm, a broad minimum at about 540 nm and an isosbestic point at about 585 nm. 3. When intracellular calcium concentration was raised in dark-adapted cells previously injected with arsenazo III, the difference spectum had two maxima at about 610 and 660 nm, a broad minimum at about 530 nm and an isosbestic point at about 585 nm. The injection of Mg2+ into dark-adapted cells previously injected with the dye induced a difference spectrum that had a single maximum at about 620 nm. Also, decreasing the intracellular pH of cells previously injected with the dye induced a difference spectrum that had a minimum at about 620 nm. The evidence suggests that there is a rise of intracellular ionized calcium when a Limulus ventral photoreceptor is light-adapted. 4. The intracellular calcium concentration, [Ca2+]1, in light-adapted photoreceptors was estimated to reach at least 10-4 M by compaing the light-induced difference spectra measured in ventral photoreceptors with a standard curve determined in microcuvettes containing 2mM arsenazo III in 400 mM-KCl, 1 mM-MgCl2 and 25 mM MOPS at pH 7·0. 5. In cells injected to less than 3 mM arsenazo III, light induced a transient decrease in optical transmission at 660 nm (T660). This decrease in T660 indicates that illumination of a ventral photoreceptor normally causes a transient increase of [Ca2+]1. 6. Arsenazo III was found to be sensitive, selective and rapid enough to measure light-induced changes of intracellular ionized calcium in Limulus ventral photoreceptor cells. PMID:17732

An initial investigation of multidimensional flow and transverse mixing characteristics of the Ohio River near Cincinnati, Ohio

USGS Publications Warehouse

Holtschlag, David J.

2009-01-01

Two-dimensional hydrodynamic and transport models were applied to a 34-mile reach of the Ohio River from Cincinnati, Ohio, upstream to Meldahl Dam near Neville, Ohio. The hydrodynamic model was based on the generalized finite-element hydrodynamic code RMA2 to simulate depth-averaged velocities and flow depths. The generalized water-quality transport code RMA4 was applied to simulate the transport of vertically mixed, water-soluble constituents that have a density similar to that of water. Boundary conditions for hydrodynamic simulations included water levels at the U.S. Geological Survey water-level gaging station near Cincinnati, Ohio, and flow estimates based on a gate rating at Meldahl Dam. Flows estimated on the basis of the gate rating were adjusted with limited flow-measurement data to more nearly reflect current conditions. An initial calibration of the hydrodynamic model was based on data from acoustic Doppler current profiler surveys and water-level information. These data provided flows, horizontal water velocities, water levels, and flow depths needed to estimate hydrodynamic parameters related to channel resistance to flow and eddy viscosity. Similarly, dye concentration measurements from two dye-injection sites on each side of the river were used to develop initial estimates of transport parameters describing mixing and dye-decay characteristics needed for the transport model. A nonlinear regression-based approach was used to estimate parameters in the hydrodynamic and transport models. Parameters describing channel resistance to flow (Manning’s “n”) were estimated in areas of deep and shallow flows as 0.0234, and 0.0275, respectively. The estimated RMA2 Peclet number, which is used to dynamically compute eddy-viscosity coefficients, was 38.3, which is in the range of 15 to 40 that is typically considered appropriate. Resulting hydrodynamic simulations explained 98.8 percent of the variability in depth-averaged flows, 90.0 percent of the variability in water levels, 93.5 percent of the variability in flow depths, and 92.5 percent of the variability in velocities. Estimates of the water-quality-transport-model parameters describing turbulent mixing characteristics converged to different values for the two dye-injection reaches. For the Big Indian Creek dye-injection study, an RMA4 Peclet number of 37.2 was estimated, which was within the recommended range of 15 to 40, and similar to the RMA2 Peclet number. The estimated dye-decay coefficient was 0.323. Simulated dye concentrations explained 90.2 percent of the variations in measured dye concentrations for the Big Indian Creek injection study. For the dye-injection reach starting downstream from Twelvemile Creek, however, an RMA4 Peclet number of 173 was estimated, which is far outside the recommended range. Simulated dye concentrations were similar to measured concentration distributions at the first four transects downstream from the dye-injection site that were considered vertically mixed. Farther downstream, however, simulated concentrations did not match the attenuation of maximum concentrations or cross-channel transport of dye that were measured. The difficulty of determining a consistent RMA4 Peclet was related to the two-dimension model assumption that velocity distributions are closely approximated by their depth-averaged values. Analysis of velocity data showed significant variations in velocity direction with depth in channel reaches with curvature. Channel irregularities (including curvatures, depth irregularities, and shoreline variations) apparently produce transverse currents that affect the distribution of constituents, but are not fully accounted for in a two-dimensional model. The two-dimensional flow model, using channel resistance to flow parameters of 0.0234 and 0.0275 for deep and shallow areas, respectively, and an RMA2 Peclet number of 38.3, and the RMA4 transport model with a Peclet number of 37.2, may have utility for emergency-planning purposes. Emergency-response efforts would be enhanced by continuous streamgaging records downstream from Meldahl Dam, real-time water-quality monitoring, and three-dimensional modeling. Decay coefficients are constituent specific.

Probing the Highly Efficient Electron Transfer Dynamics between Zinc Protoporphyrin IX and Sodium Titanate Nanosheets.

PubMed

Biswas, Sudipta; Mukherjee, Debdyuti; De, Swati; Kathiravan, Arunkumar

2016-09-15

Sodium titanate nanosheets (NaTiO2 NS) have been prepared by a new method and completely characterized by TEM, SEM, XRD, EDX, and XPS techniques. The sensitization of nanosheets is carried out with Zn protoporphyrin IX (ZnPPIX). The emission intensity of ZnPPIX is quenched by NaTiO2 NS, and the dominant process for this quenching has been attributed to the process of photoinduced electron injection from excited ZnPPIX to the nanosheets. Time resolved fluorescence measurement was used to elucidate the process of electron injection from the singlet state of ZnPPIX to the conduction band of NaTiO2 NS. Electron injection from the dye to the semiconductor is very fast (ket ≈ 10(11) s(-1)), much faster than previously reported rates. The large two-dimensional surface offered by the NaTiO2 NS for interaction with the dye and the favorable driving force for electron injection from ZnPPIX to NaTiO2 NS (ΔGinj = -0.66 V) are the two important factors responsible for such efficient electron injection. Thus, NaTiO2 NS can serve as an effective alternative to the use of TiO2 nanoparticles in dye sensitized solar cells (DSSCs).

An Ultralow-Dose 1-Day Protocol With Activities Lower Than 20 MBq for the Detection of Sentinel Lymph Nodes in Breast Cancer-Experiences After 150 Cases.

PubMed

Kolberg, Hans-Christian; Afsah, Shabnam; Kuehn, Thorsten; Winzer, Ute; Akpolat-Basci, Leyla; Stephanou, Miltiades; Wetzig, Sarah; Hoffmann, Oliver; Liedtke, Cornelia

2017-01-01

Common protocols for the detection of sentinel lymph nodes in early breast cancer often include the injection of the tracer 1 day before surgery. In order to detect enough activity on the day of surgery, the applied activity in many protocols is as high as several hundred MBq. So far, very few protocols with an activity below 20 MBq have been reported. We developed an ultralow-dose 1-day protocol with a mean activity lower than 20 MBq in order to reduce radiation exposure for patients and staff. Here, we are presenting our experiences in 150 consecutive cases. A total of 150 patients with clinically and sonographically negative axilla and no multicentricity underwent a sentinel lymph node biopsy using an ultralow-dose protocol performed on the day of surgery. No patient received systemic therapy prior to sentinel node biopsy. After peritumoral injection of the tracer Technetium-99m, a lymphoscintigraphy was performed in all cases. Seven minutes before the first cut, we injected 5 mL of blue dye in the region of the areola. In 148 (98.7%) of 150 patients, at least 1 sentinel lymph node could be identified by lymphoscintigraphy; the detection rate during surgery with combined tracers Technetium-99m and blue dye was 100%. The mean applied activity was 17.8 MBq (9-20). A mean number of 1.3 (0-5) sentinel lymph nodes were identified by lymphoscintigraphy and a mean number of 1.8 (1-5) sentinel lymph nodes were removed during sentinel lymph node biopsy. Ultralow-dose 1-day protocols with an activity lower than 20 MBq are a safe alternative to 1-day or 2-day protocols with significantly higher radiation doses in primary surgery for early breast cancer. Using Technetium-99m and blue dye in a dual tracer approach, detection rates of 100% are possible in clinical routine in order to reduce radiation exposure for patients and staff.

An Apparatus for Pressure Injection of Solutions into Trees

Treesearch

Thomas W. Jones; Garold F. Gregory; Garold F. Gregory

1971-01-01

The construction and use of an apparatus for injecting solutions under pressure into trees is described. A unique and important feature of the apparatus is that it permits injection of solutions into the outermost sapwood. It has been used to inject dye solutions and solubilized benomyl into elm, oak, and maple.

Possibility of Aggravation of Tissue Sclerosis after Injection of Multipotent Mesenchymal Stromal Cells Near the Forming Cicatrix in the Experiment.

PubMed

Maiborodin, I V; Morozov, V V; Anikeev, A A; Figurenko, N F; Maslov, R V; Matveeva, V A; Chastikina, G A; Maiborodina, V I

2017-08-01

The peculiarities of tissue sclerosis after injection of autologous bone marrow multipotent mesenchymal stromal cells transfected with GFP gene and stained with Vybrant CM-Dil cell membrane dye were studied by light microscopy with luminescence. The surgical intervention consisting in ligation of the great vein was followed by tissue sclerotic transformation caused by direct damage and chronic inflammation caused by the presence of slowly resorbed ligature. Injection of stromal cells after this intervention led to formation of more extensive scar. This can attest to the possibility of stromal cells differentiation into connective tissue cells, fibroblasts, and stimulation of proliferation and collagen synthesis by host fibroblasts. A decrease in the volume of dense fibrous connective tissue due to scar reorganization at latter terms cannot not excluded.

Efficacy evaluations of Mimosa pudica tannin isolate (MPT) for its anti-ophidian properties.

PubMed

Ambikabothy, Jamunaa; Ibrahim, Halijah; Ambu, Stephen; Chakravarthi, Srikumar; Awang, Khalijah; Vejayan, Jaya

2011-09-01

Evaluations of the anti-snake venom efficacy of Mimosa pudica tannin isolate (MPT) obtained from root of the plant. MPT was investigated in vitro and in vivo for its efficacy against the venom of Naja kaouthia snake. In vitro: (1) mice injected i.p. with MPT pre-incubated with Naja kaouthia venom at concentrations as low as 0.625 mg/ml showed 100% survival after a 24-h observation period. (2) In the proteomics study, mice injected with MPT pre-incubated with the Naja kaouthia venom showed down-regulation of five serum proteins. (3) In the protein-dye-binding study, the percentage of Bradford dye-protein binding showed a reduction relative to the decrease in MPT concentration used to incubate with the venom. In vivo: the results from the animal studies showed that MPT had no in vivo protection against the Naja kaouthia venom (0.875 mg/kg) in four different rescue modes and in an oral pre-treatment experiment. The study indicated the promising ability of MPT to neutralize the Naja kaouthia venom in in vitro experiments but fell short in its in vivo potential. As such, the use of Mimosa pudica (Mimosaceae) as therapeutics for snake bites is questionable as all the possible in vivo rescue studies and pre-treatment of the active constituents showed no protection against the affected mice. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Acene-modified triphenylamine dyes for dye-sensitized solar cells: a computational study.

PubMed

Fan, Wenjie; Tan, Dazhi; Deng, Wei-Qiao

2012-06-04

A series of metal-free acene-modified triphenylamine dyes (benzene to pentacene, denoted as TPA-AC1 to TPA-AC5) are investigated as organic sensitizers for application in dye-sensitized solar cells (DSSCs). A combination of density functional theory (DFT), density functional tight-binding (DFTB), and time-dependent DFT (TDDFT) approaches is employed. The effects of acene units on the spectra and electrochemical properties of the acene-modified TPA organic dyes are demonstrated. The dye/(TiO(2))(46) anatase nanoparticle systems are also simulated to show the electronic structures at the interface. The results show that from TPA-AC1 to TPA-AC5 with increasing sizes of the acenes, the absorption and fluorescence spectra are systematically broadened and red-shifted, but the oscillator strength and electron injection properties are reduced. The molecular orbital contributions show increasing localization on the bridging acene units from TPA-AC1 to TPA-AC5. From the theoretical examination of some key parameters including free enthalpy related to the electron injection, light-harvesting efficiency, and the shift of semiconductor conduction band, TPA-AC3 with an anthracene moiety demonstrates a balance of the above crucial factors. TPA-AC3 is expected to be a promising dye with desirable energetic and spectroscopic parameters in the DSSC field, which is consistent with recent experimental work. This study is expected to deepen our understanding of TPA-based organic dyes and assist the molecular design of new metal-free dyes for the further optimization of DSSCs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tuning the physical properties of organic sensitizers by replacing triphenylamine with new donors for dye sensitized solar cells - a theoretical approach.

PubMed

Ramkumar, Sekar; Manidurai, Paulraj

2017-02-15

New donor molecules with low ionization potential have been theoretically designed by replacing the benzene moieties in triphenylamine (TPA) with thiophene as well as furan. The designed new donors also exhibited planar structure, making an angle of 120° around the nitrogen atom that results in resonance effects through π-bonds of aryl rings. New sensitizers have been theoretically studied using DFT and TD-DFT by adopting these designed donors. UV-Vis absorption spectra, light harvesting ability (LHE) and electron injection ability (ΔG inject ) of the designed sensitizers have been calculated by taking L0 as reference. Orbital overlapping between donor and acceptor facilitates intra-molecular charge transfer, thereby increasing the interfacial electron injection from the sensitizer to the semiconductor nanoparticles. Our theoretical results demonstrate that sensitizers DTPA-AA and DFPA-AA have broader absorption and lower ΔG inject respectively compare to L0, this opens a new way for designing sensitizers for dye sensitized solar cells (DSSCs). All the dyes designed were found to be good light harvesters. Copyright © 2016 Elsevier B.V. All rights reserved.

Fluorescence imaging to study cancer burden on lymph nodes

NASA Astrophysics Data System (ADS)

D'Souza, Alisha V.; Elliott, Jonathan T.; Gunn, Jason R.; Samkoe, Kimberley S.; Tichauer, Kenneth M.; Pogue, Brian W.

2015-03-01

Morbidity and complexity involved in lymph node staging via surgical resection and biopsy calls for staging techniques that are less invasive. While visible blue dyes are commonly used in locating sentinel lymph nodes, since they follow tumor-draining lymphatic vessels, they do not provide a metric to evaluate presence of cancer. An area of active research is to use fluorescent dyes to assess tumor burden of sentinel and secondary lymph nodes. The goal of this work was to successfully deploy and test an intra-nodal cancer-cell injection model to enable planar fluorescence imaging of a clinically relevant blue dye, specifically methylene blue along with a cancer targeting tracer, Affibody labeled with IRDYE800CW and subsequently segregate tumor-bearing from normal lymph nodes. This direct-injection based tumor model was employed in athymic rats (6 normal, 4 controls, 6 cancer-bearing), where luciferase-expressing breast cancer cells were injected into axillary lymph nodes. Tumor presence in nodes was confirmed by bioluminescence imaging before and after fluorescence imaging. Lymphatic uptake from the injection site (intradermal on forepaw) to lymph node was imaged at approximately 2 frames/minute. Large variability was observed within each cohort.

Intratracheal administration of bacterial lipopolysaccharide elicits pulmonary hypertension in broilers with primed airways.

PubMed

Lorenzoni, A G; Wideman, R F

2008-04-01

Broilers reared under commercial conditions inhale irritant gases and aerosolized particulates contaminated with gram-negative bacteria and bacterial lipopolysaccharide (LPS). Previous studies demonstrated that i.v. injections of LPS can trigger an increase in the pulmonary arterial pressure (PAP); however, the pulmonary hemodynamic response to aerosolized LPS entering via the most common route, the respiratory tract, had not been evaluated in broilers. In experiment 1, broilers reared on new wood shavings litter in clean environmental chambers either were not pretreated (control group) or were pretreated via aerosol inhalation of substances (food color dyes and propylene glycol) known to sensitize the airways. One day later, the broilers were anesthetized, catheterized to record the PAP, and an intratracheal aerosol spray of LPS (1 mL of 2 mg/mL of LPS) was administered. Broilers in the control group as well as broilers pretreated with aerosolized distilled water or yellow and blue food color dyes did not develop pulmonary hypertension (PH; an increase in PAP) after the intratracheal spray of LPS, whereas broilers that had been pretreated with red food color did develop PH in response to intratracheal LPS. In experiment 2, birds raised under commercial conditions on used wood shavings litter developed PH in response to intratracheal LPS regardless of whether they had been pretreated with aerosolized red food color dye. In experiment 3, broilers reared in clean environmental chambers on new wood shavings litter were used to demonstrate that Red Dye #3 and propylene glycol are capable of priming the responsiveness of the airways to a subsequent intratracheal LPS challenge. Common air contaminants such as LPS can result in PH leading to pulmonary hypertension syndrome (ascites) in broilers with appropriately primed airways.

Using dye tracing to establish groundwater flow paths in a limestone marble aquifer, University of California, Santa Cruz, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, J.; Bertschinger, V.; Aley, T.

1993-04-01

Areas underlain by karst aquifers are characterized by soluble rock with sinkholes, caves, and a complex underground drainage network. Groundwater issues such as flow direction, well pumping impacts, spring recharge areas, and potential contamination transport routes are greatly complicated by the unique structure of karst aquifers. Standard aquifer analysis techniques cannot be applied unless the structure of the karst aquifer is understood. Water soluble fluorescent dyes are a powerful tool for mapping the irregular subsurface connections and flow paths in karst aquifers. Mapping the subsurface connections allows reasonable estimates of the hydrologic behavior of the aquifer. Two different fluorescent dyesmore » were injected at two points in a limestone karst aquifer system beneath the University of California, Santa Cruz campus. Flow paths in the marble were thought to be closely tied to easily recognized geomorphic alignments of sinkholes associated with fault and fracture zones. The dye tests revealed unexpected and highly complex interconnections. These complex flow paths only partially corresponded to previous surface mapping and aerial photo analysis of fracture systems. Several interfingering but hydrologically unconnected flow paths evidently exist within the cavernous aquifer. For example, dye did not appear at some discharge springs close to the dye injection points, but did appear at more distant springs. This study shows how a dye tracing study in a small, well-defined limestone body can shed light on a variety of environmental and hydrological issues, including potential well pumping impact areas, wellhead protection and recharge areas, parking lot runoff injection to aquifers, and drainage routes from hazardous materials storage areas.« less

Trypan blue staining of the anterior capsule under an air bubble with a modified cannula.

PubMed

Toprak, Ahmet Baris; Erkin, Esin Fatma; Guler, Cenap

2003-01-01

To attain good visibility of the anterior capsule in the advanced or white cataract, trypan blue 0.1% is used to stain the anterior capsule. The dye is usually injected under an air bubble. However, it is difficult to inject the dye properly due to capillary forces. An ordinary anterior chamber cannula was modified and its coverage area increased to facilitate the staining of the anterior capsule under an air bubble. The anterior capsule was stained properly by using the modified cannula in all of the cases.

Intracellular calcium movements during excitation–contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers

PubMed Central

Hollingworth, Stephen

2012-01-01

In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller. PMID:22450485

Analysis of solvent dyes in refined petroleum products by electrospray ionization mass spectrometry

USGS Publications Warehouse

Rostad, C.E.

2010-01-01

Solvent dyes are used to color refined petroleum products to enable differentiation between gasoline, diesel, and jet fuels. Analysis for these dyes in the hydrocarbon product is difficult due to their very low concentrations in such a complex matrix. Flow injection analysis/electrospray ionization/mass spectrometry in both negative and positive mode was used to optimize ionization of ten typical solvent dyes. Samples of hydrocarbon product were analyzed under similar conditions. Positive electrospray ionization produced very complex spectra, which were not suitably specific for targeting only the dyes. Negative electrospray ionization produced simple spectra because aliphatic and aromatic moieties were not ionized. This enabled screening for a target dye in samples of hydrocarbon product from a spill.

Measurement of discharge using tracers

USGS Publications Warehouse

Kilpatrick, Frederick A.; Cobb, Ernest D.

1984-01-01

The development of fluorescent dyes and fluorometers that can measure these dyes at very low concentrations has made dye-dilution methods practical for measuring discharge. These methods are particularly useful for determining discharge under certain flow conditions that are unfavorable for current meter measurements. These include small streams, canals, and pipes where:Turbulence is excessive for current meter measurement but conducive to good mixing.Moving rocks and debris are damaging to any instruments placed in the flow.Cross-sectional areas or velocities are indeterminant or changing.There are some unsteady flows such as exist with storm-runoff events on small streams.The flow is physically inaccessible or unsafe.From a practical standpoint, such measurements are limited primarily to small streams due to excessively long channel mixing lengths required of larger streams. Very good accuracy can be obtained provided:Adequate mixing length and time are allowed.Careful field and laboratory techniques are employed.Dye losses are not significant.This manual describes the slug-injection and constant-rate injection methods of performing tracer-dilution measurements. Emphasis is on the use of fluorescent dyes as tracers and the equipment, field methods, and Laboratory procedures for performing such measurements. The tracer-velocity method is also briefly discussed.

Bi-anchoring organic sensitizers of type D-(π-A)2 comprising thiophene-2-acetonitrile as π-spacer and malonic acid as electron acceptor for dye sensitized solar cell applications

NASA Astrophysics Data System (ADS)

Reddy, Gachumale Saritha; Ramkumar, Sekar; Asiri, Abdullah M.; Anandan, Sambandam

2015-06-01

Two new bi-anchoring organic sensitizers of type D-(π-A)2 comprising the identical π-spacer (thiophene-2-acetonitrile) and electron acceptor (malonic acid) but different aryl amine as electron donors (diphenylamine and carbazole) were synthesized, characterized and fabricated metal free dye-sensitized solar cell devices. The intra molecular charge transfer property and electrochemical property of these dyes were investigated by molecular absorption, emission, cyclic voltammetric experiments and in addition, quantum chemical calculation studies were performed to provide sufficient driving force for the electron injection into the conduction band of TiO2 which leads to efficient charge collection. Among the fabricated devices, carbazole based device exhibits high current conversion efficiency (η = 4.7%) with a short circuit current density (JSC) 15.3 mA/cm2, an open circuit photo voltage (VOC) of 0.59 V and a fill factor of 0.44 under AM 1.5 illumination (85 mW/cm2) compared to diphenylamine based device.

Tracer simulation study of potential solute movement in Port Royal Sound, South Carolina

USGS Publications Warehouse

Kilpatrick, F.A.; Cummings, T. Ray

1972-01-01

A tracer study was conducted in Port Royal Sound to simulate the movement and ultimate pattern of concentration of a solute continuously injected into the flow. A total of 750 pounds of Rhodamine WT dye was injected by boat during a period of 24.8 hours in a line across the Colleton River. During the following 43 days, samples of water were taken at selected points in the sound, and the concentration of dye in the samples was determined by fluorometric analysis. The data obtained in the field study were used with theoretical models to compute the ultimate pattern of concentration of nonconservative and conservative solutes for a hypothetical continuous injection at the site on the Colleton River.

Sentinel Lymph Node (SLN) laparoscopic assessment early stage in endometrial cancer.

PubMed

Gargiulo, T; Giusti, M; Bottero, A; Leo, L; Brokaj, L; Armellino, F; Palladin, L

2003-06-01

The aim of the study was to demonstrate the validity of sentinel lymph node (SLN) detection after injection of radioactive isotope and patent blue dye in patients affected by early stage endometrial cancer. The second purpose was to compare radioactive isotope and patent blue dye migration. Between September 2000 and May 2001, 11 patients with endometrial cancer FIGO stage Ib (n=10) and IIa (n=1) underwent laparoscopic SLN detection during laparoscopic assisted vaginal hysterectomy with bilateral salpingo-oophorectomy and pelvic bilateral systematic lymphadenectomy. Radioactive isotope injection was performed 24 ours before surgery and blue dye injection was performed just before surgery in the cervix at 3, 6, 9 and 12 hours. A 350 mm laparoscopic gamma-scintiprobe MR 100 type 11, (99m)Tc setted (Pol.Hi.Tech.), was used intraoperatively for detecting SLN. Seventeen SLN were detected at lymphoscintigraphy (6 bilateral and 5 monolateral). At laparoscopic surgery the same locations were found belonging at internal iliac lymph nodes (the so called "Leveuf-Godard" area, lateral to the inferior vescical artery, ventral to the origin of uterine artery and medial or caudal to the external iliac vein). Fourteen SLN were negative at histological analysis and only 3 positive for micrometastasis (mean SLN sections = 60. All the other pelvic lymph nodes were negative at histological analysis. The same SLN locations detected with g-scintiprobe were observed during laparoscopy after patent blue dye injection. If the sensitivity of the assessment of SLN is confirmed to be 100%, this laparoscopic approach could change the management of early stage endometrial cancer. The clinical validity of this technique must be evaluated prospectively.

A study of the Coriolis effect on the fluid flow profile in a centrifugal bioreactor.

PubMed

Detzel, Christopher J; Thorson, Michael R; Van Wie, Bernard J; Ivory, Cornelius F

2009-01-01

Increasing demand for tissues, proteins, and antibodies derived from cell culture is necessitating the development and implementation of high cell density bioreactors. A system for studying high density culture is the centrifugal bioreactor (CCBR), which retains cells by increasing settling velocities through system rotation, thereby eliminating diffusional limitations associated with mechanical cell retention devices. This article focuses on the fluid mechanics of the CCBR system by considering Coriolis effects. Such considerations for centrifugal bioprocessing have heretofore been ignored; therefore, a simpler analysis of an empty chamber will be performed. Comparisons are made between numerical simulations and bromophenol blue dye injection experiments. For the non-rotating bioreactor with an inlet velocity of 4.3 cm/s, both the numerical and experimental results show the formation of a teardrop shaped plume of dye following streamlines through the reactor. However, as the reactor is rotated, the simulation predicts the development of vortices and a flow profile dominated by Coriolis forces resulting in the majority of flow up the leading wall of the reactor as dye initially enters the chamber, results are confirmed by experimental observations. As the reactor continues to fill with dye, the simulation predicts dye movement up both walls while experimental observations show the reactor fills with dye from the exit to the inlet. Differences between the simulation and experimental observations can be explained by excessive diffusion required for simulation convergence, and a slight density difference between dyed and un-dyed solutions. Implications of the results on practical bioreactor use are also discussed. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

A Study of the Coriolis Effect on the Fluid Flow Profile in a Centrifugal Bioreactor

PubMed Central

Detzel, Christopher J.; Thorson, Michael R.; Van Wie, Bernard J.; Ivory, Cornelius F.

2011-01-01

Increasing demand for tissues, proteins, and antibodies derived from cell culture is necessitating the development and implementation of high cell density bioreactors. A system for studying high density culture is the centrifugal bioreactor (CCBR) which retains cells by increasing settling velocities through system rotation, thereby eliminating diffusional limitations associated with mechanical cell retention devices. This paper focuses on the fluid mechanics of the CCBR system by considering Coriolis effects. Such considerations for centrifugal bioprocessing have heretofore been ignored; therefore a simpler analysis of an empty chamber will be performed. Comparisons are made between numerical simulations and bromophenol blue dye injection experiments. For the non-rotating bioreactor with an inlet velocity of 4.3 cm/s, both the numerical and experimental results show the formation of a teardrop shaped plume of dye following streamlines through the reactor. However, as the reactor is rotated the simulation predicts the development of vortices and a flow profile dominated by Coriolis forces resulting in the majority of flow up the leading wall of the reactor as dye initially enters the chamber, results confirmed by experimental observations. As the reactor continues to fill with dye, the simulation predicts dye movement up both walls while experimental observations show the reactor fills with dye from the exit to the inlet. Differences between the simulation and experimental observations can be explained by excessive diffusion required for simulation convergence, and a slight density difference between dyed and un-dyed solutions. Implications of the results on practical bioreactor use are also discussed. PMID:19455639

Probing the Relative Photoinjection Yields of Monomer and Aggregated Dyes into ZnO Crystals.

PubMed

King, Laurie A; Parkinson, B A

2017-01-17

Cyanine dyes, often used in dye-sensitized solar cells (DSSCs), form a range of molecular species from monomers to large H and J aggregates in both solution and when adsorbed at a photoelectrode surface. To determine the relative capability of the different dye species to inject photoexcited electrons into a wideband gap oxide semiconductor, sensitization at a single-crystal zinc oxide surface was studied by simultaneous attenuated reflection (ATR) ultraviolet-visible (UV-vis) absorption and photocurrent spectroscopy measurements. ATR measurements enable identification of the dye species populating the surface with simultaneous photocurrent spectroscopy to identify the contribution of the various dye forms to photocurrent signal. We study the dye 2,2'-carboxymethylthiodicarbocyanine bromide that is particularly prone to aggregation both in solution and at the surface of sensitized oxide semiconductors.

Targeting tumor hypoxia with 2-nitroimidazole-indocyanine green dye conjugates

PubMed Central

Xu, Yan; Zanganeh, Saeid; Mohammad, Innus; Aguirre, Andres; Wang, Tianheng; Yang, Yi; Kuhn, Liisa; Smith, Michael B.

2013-01-01

Abstract. Tumor hypoxia is a major indicator of treatment resistance to chemotherapeutic drugs, and fluorescence optical tomography has tremendous potential to provide clinically useful, functional information by identifying tumor hypoxia. The synthesis of a 2-nitroimidazole-indocyanine green conjugate using a piperazine linker (piperazine-2-nitroimidazole-ICG) capable of robust fluorescent imaging of tumor hypoxia is described. In vivo mouse tumor imaging studies were completed and demonstrate an improved imaging capability of the new dye relative to an earlier version of the dye that was synthesized with an ethanolamine linker (ethanolamine-2-nitroimidazole-ICG). Mouse tumors located at imaging depths of 1.5 and 2.0 cm in a turbid medium were imaged at various time points after intravenous injection of the dyes. On average, the reconstructed maximum fluorescence concentration of the tumors injected with piperazine-2-nitroimidazole-ICG was twofold higher than that injected with ethanolamine-2-nitroimidazole-ICG within 3 h postinjection period and 1.6 to 1.7 times higher beyond 3 h postinjection. The untargeted bis-carboxylic acid ICG completely washed out after 3 h postinjection. Thus, the optimal window to assess tumor hypoxia is beyond 3 h postinjection. These findings were supported with fluorescence images of histological sections of tumor samples and an immunohistochemistry technique for identifying tumor hypoxia. PMID:23764695

Ultrafast charge separation dynamics in opaque, operational dye-sensitized solar cells revealed by femtosecond diffuse reflectance spectroscopy

PubMed Central

Ghadiri, Elham; Zakeeruddin, Shaik M.; Hagfeldt, Anders; Grätzel, Michael; Moser, Jacques-E.

2016-01-01

Efficient dye-sensitized solar cells are based on highly diffusive mesoscopic layers that render these devices opaque and unsuitable for ultrafast transient absorption spectroscopy measurements in transmission mode. We developed a novel sub-200 femtosecond time-resolved diffuse reflectance spectroscopy scheme combined with potentiostatic control to study various solar cells in fully operational condition. We studied performance optimized devices based on liquid redox electrolytes and opaque TiO2 films, as well as other morphologies, such as TiO2 fibers and nanotubes. Charge injection from the Z907 dye in all TiO2 morphologies was observed to take place in the sub-200 fs time scale. The kinetics of electron-hole back recombination has features in the picosecond to nanosecond time scale. This observation is significantly different from what was reported in the literature where the electron-hole back recombination for transparent films of small particles is generally accepted to occur on a longer time scale of microseconds. The kinetics of the ultrafast electron injection remained unchanged for voltages between +500 mV and –690 mV, where the injection yield eventually drops steeply. The primary charge separation in Y123 organic dye based devices was clearly slower occurring in two picoseconds and no kinetic component on the shorter femtosecond time scale was recorded. PMID:27095505

Does the endolymph pass through the base of the cupula?

NASA Astrophysics Data System (ADS)

Jijiwa, H.; Watanabe, N.; Hattori, T.; Matuda, F.; Hashiba, M.; Mizuno, Y.; Shindo, M.; Watanabe, S.

2001-08-01

Whether the endolymph of the semicircular canal passes the cupular partition or not was examined using the lateral semicircular canal system of adult pigeons (Columba livia). By applying various pressures by means of injection of a dye solution through the membranous canal, it was found that the dye solution was seen to pass the cupula even under very low pressures when the pressure was increased gradually. When pulled by a magnet, the ultrafine particles of the dextran magnetite contained in the injected fluid were found to pass through the subcupular space without evident increase of the ampullary pressure.

Quantitative investigation of resolution increase of free-flow electrophoresis via simple interval sample injection and separation.

PubMed

Shao, Jing; Fan, Liu-Yin; Cao, Cheng-Xi; Huang, Xian-Qing; Xu, Yu-Quan

2012-07-01

Interval free-flow zone electrophoresis (FFZE) has been used to suppress sample band broadening greatly hindering the development of free-flow electrophoresis (FFE). However, there has been still no quantitative study on the resolution increase of interval FFZE. Herein, we tried to make a comparison between bandwidths in interval FFZE and continuous one. A commercial dye with methyl green and crystal violet was well chosen to show the bandwidth. The comparative experiments were conducted under the same sample loading of the model dye (viz. 3.49, 1.75, 1.17, and 0.88 mg/h), the same running time (viz. 5, 10, 15, and 20 min), and the same flux ratio between sample and background buffer (= 10.64 × 10⁻³). Under the given conditions, the experiments demonstrated that (i) the band broadening was evidently caused by hydrodynamic factor in continuous mode, and (ii) the interval mode could clearly eliminate the hydrodynamic broadening existing in continuous mode, greatly increasing the resolution of dye separation. Finally, the interval FFZE was successfully used for the complete separation of two-model antibiotics (herein pyoluteorin and phenazine-1-carboxylic acid coexisting in fermentation broth of a new strain Pseudomonas aeruginosa M18), demonstrating the feasibility of interval FFZE mode for separation of biomolecules. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proton-Induced Trap States, Injection and Recombination Dynamics in Water-Splitting Dye-Sensitized Photoelectrochemical Cells.

PubMed

McCool, Nicholas S; Swierk, John R; Nemes, Coleen T; Saunders, Timothy P; Schmuttenmaer, Charles A; Mallouk, Thomas E

2016-07-06

Water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs) utilize a sensitized metal oxide and a water oxidation catalyst in order to generate hydrogen and oxygen from water. Although the Faradaic efficiency of water splitting is close to unity, the recombination of photogenerated electrons with oxidized dye molecules causes the quantum efficiency of these devices to be low. It is therefore important to understand recombination mechanisms in order to develop strategies to minimize them. In this paper, we discuss the role of proton intercalation in the formation of recombination centers. Proton intercalation forms nonmobile surface trap states that persist on time scales that are orders of magnitude longer than the electron lifetime in TiO2. As a result of electron trapping, recombination with surface-bound oxidized dye molecules occurs. We report a method for effectively removing the surface trap states by mildly heating the electrodes under vacuum, which appears to primarily improve the injection kinetics without affecting bulk trapping dynamics, further stressing the importance of proton control in WS-DSPECs.

Electromagnetic navigational bronchoscopy with dye marking for identification of small peripheral lung nodules during minimally invasive surgical resection

PubMed Central

Muñoz-Largacha, Juan A.; Ebright, Michael I.; Litle, Virginia R.

2017-01-01

Background Identification of small peripheral lung nodules during minimally invasive resection can be challenging. Electromagnetic navigational bronchoscopy (ENB) with injection of dye to identify nodules can be performed by the surgeon immediately prior to resection. We evaluated the effectiveness of ENB with dye marking to aid minimally invasive resection. Methods Patients with peripheral pulmonary nodules underwent ENB before planned thoracoscopic or robotic-assisted thoracoscopic resection. Methylene blue was injected directly into the lesion for pleural-based lesions or peripherally for lesions deep to the pleural surface. Surgical resection was then immediately performed. Technical success was defined as identification of the dye marking within/close to the lesion with pathological confirmation after minimally invasive surgical resection. Results Seventeen patients (19 nodules) underwent ENB with dye marking followed by minimally invasive resection. Median lesion size was 9 mm (4–32 mm) and the median distance from the pleura was 9.5 mm (1–40 mm). Overall success rate was 79% (15/19). In two cases the dye was not visualized and in the remaining two there was extravasation of dye into the pleural space. There were trends favoring technical success for nodules that were larger or closer to the pleural surface. Five patients required adhesiolysis to visualize the target lesion and all were successful. There were no significant adverse events and a definitive diagnosis was ultimately accomplished in all patients. Conclusions ENB with dye marking is useful for guiding minimally invasive resection of small peripheral lung nodules. ENB can be undertaken immediately before performing resection in the operating room. This improves workflow and avoids the need for a separate localization procedure. PMID:28449489

Spectral characteristics and photosensitization of TiO2 nanoparticles in reverse micelles by perylenes.

PubMed

Hernández, Laura I; Godin, Robert; Bergkamp, Jesse J; Llansola Portolés, Manuel J; Sherman, Benjamin D; Tomlin, John; Kodis, Gerdenis; Méndez-Hernández, Dalvin D; Bertolotti, Sonia; Chesta, Carlos A; Mariño-Ochoa, Ernesto; Moore, Ana L; Moore, Thomas A; Cosa, Gonzalo; Palacios, Rodrigo E

2013-04-25

We report on the photosensitization of titanium dioxide nanoparticles (TiO2 NPs) synthesized inside AOT (bis(2-ethylhexyl) sulfosuccinate sodium salt) reverse micelles following photoexcitation of perylene derivatives with dicarboxylate anchoring groups. The dyes, 1,7-dibromoperylene-3,4,9,10-tetracarboxy dianhydride (1), 1,7-dipyrrolidinylperylene-3,4,9,10-tetracarboxy dianhydride (2), and 1,7-bis(4-tert-butylphenyloxy)perylene-3,4,9,10-tetracarboxy dianhydride (3), have considerably different driving forces for photoinduced electron injection into the TiO2 conduction band, as estimated by electrochemical measurements and quantum mechanical calculations. Fluorescence anisotropy measurements indicate that dyes 1 and 2 are preferentially solubilized in the micellar structure, creating a relatively large local concentration that favors the attachment of the dye to the TiO2 surface. The binding process was followed by monitoring the hypsochromic shift of the dye absorption spectra over time for 1 and 2. Photoinduced electron transfer from the singlet excited state of 1 and 2 to the TiO2 conduction band (CB) is indicated by emission quenching of the TiO2-bound form of the dyes and confirmed by transient absorption measurements of the radical cation of the dyes and free carriers (injected electrons) in the TiO2 semiconductor. Steady state and transient spectroscopy indicate that dye 3 does not bind to the TiO2 NPs and does not photosensitize the semiconductor. This observation was rationalized as a consequence of the bulky t-butylphenyloxy groups which create a strong steric impediment for deep access of the dye within the micelle structure to reach the semiconductor oxide surface.

Rationalizing the suitability of rhodamines as chromophores in dye-sensitized solar cells: A systematic molecular design study

DOE PAGES

Pepe, Giulio; Cole, Jacqueline M.; Waddell, Paul G.; ...

2016-09-30

Here, rhodamines are chromophores that are employed in many dye applications. Their strong optical absorption in the visible region of the electromagnetic spectrum renders them attractive dye candidates for dye-sensitized solar cells (DSCs). However, they have not yet been systematically tested in DSCs as single- or co-sensitizers. Recent advances in concerted experimental and computational workflows involving molecular design protocols can afford a better understanding of the molecular origins of the optoelectronic properties in these sensitizers. Herein, we examine the suitability of rhodamines R560 (1), R575 (2), R590 (3), R610 (4), R620 (5), R640 (6), and R3B (7) as chromophores inmore » co-sensitized DSCs. Our study follows a stepwise approach. Initially, structural and optical properties of the dyes are investigated by experimental and computational methods to reveal structure-property relationships and other useful features for DSC applications. Subsequently, 1-7 are investigated at the dye···TiO 2 interface, both by calculations of dye-adsorption onto the surface of a modeled (TiO 2) 9 cluster, and by experimental studies of dye-adsorption on TiO 2. For that purpose, a selection of rhodamine dyes are paired together (1 and 5) and (1 and 7) for co-sensitization, among which 5 is also co-adsorbed with a fluorescein dye in order to explore chemical compatibility factors. The best dye candidates are identified from the findings of these adsorption studies in terms of dye aggregation, anchoring modes, and panchromatic response. Despite their promising dye…TiO 2 adsorption and optical prospects, our results show that rhodamines lack a suitable intramolecular charge transfer pathway for dye-to-TiO 2 electron injection to occur, thus precluding their photovoltaic function as DSC dyes. Our results are then assessed against ostensibly disparate reports of rhodamines performing successfully in DSC devices; this comparison necessitated the internal reproduction of previously reported co-sensitization experiments on 2 with the industrial standard reference dye, N3. We achieve reconciliation between our results and those in the literature by reasoning that while rhodamines cannot deliver photovoltaic function in DSCs in their own right, they can either act to facilitate or deplete the photovoltaic output of a DSC indirectly by affecting the TiO 2 adsorption prospects of a photovoltaic-active dye with which a rhodamine is co-sensitized.« less

Laser-induced fluorescence spectroscopy in tissue local necrosis detection

NASA Astrophysics Data System (ADS)

Cip, Ondrej; Buchta, Zdenek; Lesundak, Adam; Randula, Antonin; Mikel, Bretislav; Lazar, Josef; Veverkova, Lenka

2014-03-01

The recent effort leads to reliable imaging techniques which can help to a surgeon during operations. The fluorescence spectroscopy was selected as very useful online in vivo imaging method to organics and biological materials analysis. The presented work scopes to a laser induced fluorescence spectroscopy technique to detect tissue local necrosis in small intestine surgery. In first experiments, we tested tissue auto-fluorescence technique but a signal-to-noise ratio didn't express significant results. Then we applied a contrast dye - IndoCyanine Green (ICG) which absorbs and emits wavelengths in the near IR. We arranged the pilot experimental setup based on highly coherent extended cavity diode laser (ECDL) used for stimulating of some critical areas of the small intestine tissue with injected ICG dye. We demonstrated the distribution of the ICG exciter with the first file of shots of small intestine tissue of a rabbit that was captured by high sensitivity fluorescent cam.

Studies on the optical and photoelectric properties of anthocyanin and chlorophyll as natural co-sensitizers in dye sensitized solar cell

NASA Astrophysics Data System (ADS)

Nan, Hui; Shen, He-Ping; Wang, Gang; Xie, Shou-Dong; Yang, Gui-Jun; Lin, Hong

2017-11-01

Anthocyanin and Chlorophyll extracted from Troll flower and Cypress leaf respectively are used as natural sensitizers in dye sensitized solar cells (DSCs), with their optical and electrochemical properties investigated. UV-Vis absorption measurement showed that the mixture of two dyes enabled an enhanced and wider absorption in the wavelength range of 300 nm-700 nm compared to each single dye. FTIR results proved that anthocyanin is chemically adsorbed onto the TiO2 film, while it is physical adsorption for chlorophyll. The energy level offsets on the TiO2/dye/electrolyte interface for each dye and the dye mixture with different ratios were calculated from the electrochemical analysis, which affect the electron injection and dye regeneration efficiencies. The optimized ratio of the two dyes in the mixture was found to be ∼2:5, inducing both sufficient charge transfer driving force and minimal energy loss. By incorporating this mixture into the solar cell as co-adsorbing sensitizer, the photovoltaic performance was prominently improved compared with the single dye sensitization system.

Measurement of discharge using tracers

USGS Publications Warehouse

Kilpatrick, F.A.; Cobb, Ernest D.

1985-01-01

The development of fluorescent dyes and fluorometers that can measure these dyes at very low concentrations has made dye-dilution methods practical for measuring discharge. These methods are particularly useful for determining discharge under certain flow conditions that are unfavorable for current meter measurements. These include small streams, canals, and pipes where 1. Turbulence is excessive for current-meter measurement but conducive to good mixing. 2. Moving rocks and debris may damage instruments placed in the flow. 3. Cross-sectional areas or velocities are indeterminate or changing. 4. The flow is unsteady, such as the flow that exists with storm-runoff events on small streams and urban storm-sewer systems. 5. The flow is physically inaccessible or unsafe. From a practical standpoint, such methods are limited primarily to small streams, because of the excessively long channel-mixing lengths required for larger streams. Very good accuracy can be obtained provided that 1. Adequate mixing length and time are allowed. 2. Careful field and laboratory techniques are used. 3. Dye losses are not significant. This manual describes the slug-injection and constant-rate injection methods of performing tracer-dilution measurements. Emphasis is on the use of fluorescent dyes as tracers and the equipment, field methods, and laboratory procedures for performing such measurements. The tracer-velocity method is also briefly discussed.

In vivo photoacoustic and ultrasonic mapping of rat sentinel lymph nodes with a modified commercial ultrasound imaging system

NASA Astrophysics Data System (ADS)

Erpelding, Todd N.; Kim, Chulhong; Pramanik, Manojit; Guo, Zijian; Dean, John; Jankovic, Ladislav; Maslov, Konstantin; Wang, Lihong V.

2010-02-01

Sentinel lymph node biopsy (SLNB) has become the standard method for axillary staging in breast cancer patients, relying on invasive identification of sentinel lymph nodes (SLNs) following injection of blue dye and radioactive tracers. While SLNB achieves a low false negative rate (5-10%), it is an invasive procedure requiring ionizing radiation. As an alternative to SLNB, ultrasound-guided fine needle aspiration biopsy has been tested clinically. However, ultrasound alone is unable to accurately identify which lymph nodes are sentinel. Therefore, a non-ionizing and noninvasive detection method for accurate SLN mapping is needed. In this study, we successfully imaged methylene blue dye accumulation in vivo in rat axillary lymph nodes using a Phillips iU22 ultrasound imaging system adapted for photoacoustic imaging with an Nd:YAG pumped, tunable dye laser. Photoacoustic images of rat SLNs clearly identify methylene blue dye accumulation within minutes following intradermal dye injection and co-registered photoacoustic/ultrasound images illustrate lymph node position relative to surrounding anatomy. To investigate clinical translation, the imaging depth was extended up to 2.5 cm by adding chicken breast tissue on top of the rat skin surface. These results raise confidence that photoacoustic imaging can be used clinically for accurate, noninvasive SLN mapping.

Time of travel of the Flint River, Utah Dam to highway M-13, Michigan, August 4-8, 1981

USGS Publications Warehouse

Cummings, T. Ray; Miller, John B.

1982-01-01

Tracing of rhodamine WT dye has provided time-of-travel data for waste-load allocation studies of a 42.8-mile reach of the Flint River at low flow. A discharge equaled or exceeded about 90 percent of the time was measured at Grand Traverse Street in Flint before dye injection. Dye was injected at two locations in Flint--at Utah Dam and at Grand Traverse Street, From Utah Dam to Grand Traverse Street, the mean velocity of flow was about 0.1 foot per second; time-of-travel was 35.3 hours. From Grand Traverse Street to Highway M-13, mean velocity was about 0.7 foot per second; time-of-travel was 78.8 hours. Time-of-travel for the reach between Utah Dam and Highway M-13 was thus 114 hours.

Modulated charge injection in p-type dye-sensitized solar cells using fluorene-based light absorbers.

PubMed

Liu, Zonghao; Xiong, Dehua; Xu, Xiaobao; Arooj, Qudsia; Wang, Huan; Yin, Liyuan; Li, Wenhui; Wu, Huaizhi; Zhao, Zhixin; Chen, Wei; Wang, Mingkui; Wang, Feng; Cheng, Yi-Bing; He, Hongshan

2014-03-12

In this study, new pull-push arylamine-fluorene based organic dyes zzx-op1, zzx-op2, and zzx-op3 have been designed and synthesized for p-type dye-sensitized solar cells (p-DSCs). In zzx-op1, a di(p-carboxyphenyl)amine (DCPA) was used as an electron donor, a perylenemonoimide (PMID) as an electron acceptor, and a fluorene (FLU) unit with two aliphatic hexyl chains as a π-conjugated linker. In zzx-op2 and zzx-op3, a 3,4-ethylenedioxythiophene (EDOT) and a thiophene were inserted consecutively between PMID and FLU to tune the energy levels of the frontier molecular orbitals of the dyes. The structural modification broadened the spectral coverage from an onset of 700 nm for zzx-op1 to 750 nm for zzx-op3. The electron-rich EDOT and thiophene lifted up the HOMO (highest occupied molecular orbital) levels of zzx-op2 and zzx-op3, making their potential more negative than zzx-op1. When three dyes were employed in p-type DSCs with I(-)/I3(-) as a redox couple and NiO nanoparticles as hole materials, zzx-op1 exhibited impressive energy conversion efficiency of 0.184% with the open-circuit voltage (VOC) of 112 mV and the short-circuit current density (JSC) of 4.36 mA cm(-2) under AM 1.5G condition. Density functional theory calculations, transient photovoltage decay measurements, and electrochemical impedance spectroscopic studies revealed that zzx-op1 sensitized solar cell exhibited much higher charge injection efficiency (90.3%) than zzx-op2 (53.9%) and zzx-op3 (39.0%), indicating a trade-off between spectral broadening and electron injection driving force in p-type DSCs.

Multiple electron injection dynamics in linearly-linked two dye co-sensitized nanocrystalline metal oxide electrodes for dye-sensitized solar cells.

PubMed

Shen, Qing; Ogomi, Yuhei; Park, Byung-wook; Inoue, Takafumi; Pandey, Shyam S; Miyamoto, Akari; Fujita, Shinsuke; Katayama, Kenji; Toyoda, Taro; Hayase, Shuzi

2012-04-07

Understanding the electron transfer dynamics at the interface between dye sensitizer and semiconductor nanoparticle is very important for both a fundamental study and development of dye-sensitized solar cells (DSCs), which are a potential candidate for next generation solar cells. In this study, we have characterized the ultrafast photoexcited electron dynamics in a newly produced linearly-linked two dye co-sensitized solar cell using both a transient absorption (TA) and an improved transient grating (TG) technique, in which tin(IV) 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (NcSn) and cis-diisothiocyanato-bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(II) bis(tetrabutylammonium) (N719) are molecularly and linearly linked and are bonded to the surface of a nanocrystalline tin dioxide (SnO(2)) electrode by a metal-O-metal linkage (i.e. SnO(2)-NcSn-N719). By comparing the TA and TG kinetics of NcSn, N719, and hybrid NcSn-N719 molecules adsorbed onto both of the SnO(2) and zirconium dioxide (ZrO(2)) nanocrystalline films, the forward and backward electron transfer dynamics in SnO(2)-NcSn-N719 were clarified. We found that there are two pathways for electron injection from the linearly-linked two dye molecules (NcSn-N719) to SnO(2). The first is a stepwise electron injection, in which photoexcited electrons first transfer from N719 to NcSn with a transfer time of 0.95 ps and then transfer from NcSn to the conduction band (CB) of SnO(2) with two timescales of 1.6 ps and 4.2 ps. The second is direct photoexcited electron transfer from N719 to the CB of SnO(2) with a timescale of 20-30 ps. On the other hand, back electron transfer from SnO(2) to NcSn is on a timescale of about 2 ns, which is about three orders of magnitude slower compared to the forward electron transfer from NcSn to SnO(2). The back electron transfer from NcSn to N719 is on a timescale of about 40 ps, which is about one order slower compared to the forward electron transfer from N719 to NcSn. These results demonstrate that photoexcited electrons can be effectively injected into SnO(2) from both of the N719 and NcSn dyes.

Application of organic IR788-loaded semi-interpenetrating network dyes for photoacoustic imaging

NASA Astrophysics Data System (ADS)

Phuc Nguyen, Van; Kim, Hyejin; Kang, Mingyeong; Kwak, Minseok; Kang, Hyun Wook

2017-07-01

In this study, we present the feasibility of a biocompatible Lumogen® IR788-loaded polymeric nanoparticle (NP) as a novel photoabsorbing agent for photoacoustic (PA) imaging. The NP was fabricated through a semi-interpenetrating network (sIPN) within the core of F127 resulting in IR788-sIPN formation. To evaluate the PA sensitivity of the material, tubing phantoms were injected with various concentrations of IR788-sIPN, and H1975 lung-tumor-bearing mice were intratumorally injected with IR788-sIPN. Compared with the background, the PA contrast was enhanced up to 80 and 40% in the phantom and in vivo experiments, respectively. IR788-sIPN can be a feasible IR-absorbing material for early cancer detection.

First principles DFT study of dye-sensitized CdS quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jain, Kalpna; Singh, Kh. S.; Kishor, Shyam, E-mail: shyam387@gmail.com

2014-04-24

Dye-sensitized quantum dots (QDs) are considered promising candidates for dye-sensitized solar cells. In order to maximize their efficiency, detailed theoretical studies are important. Here, we report a first principles density functional theory (DFT) investigation of experimentally realized dye - sensitized QD / ligand systems, viz., Cd{sub 16}S{sub 16}, capped with acetate molecules and a coumarin dye. The hybrid B3LYP functional and a 6−311+G(d,p)/LANL2dz basis set are used to study the geometric, energetic and electronic properties of these clusters. There is significant structural rearrangement in all the clusters studied - on the surface for the bare QD, and in the positionsmore » of the acetate / dye ligands for the ligated QDs. The density of states (DOS) of the bare QD shows states in the band gap, which disappear on surface passivation with the acetate molecules. Interestingly, in the dye-sensitised QD, the HOMO is found to be localized mainly on the dye molecule, while the LUMO is on the QD, as required for photo-induced electron injection from the dye to the QD.« less

Sterility in male animals induced by injection of chemical agents into the vas deferens.

PubMed

Freeman, C; Coffey, D S

1973-11-01

This study was undertaken to develop a simple non-surgical technic for achieving male sterility. The method induces obstruction in the vas deferens by injecting sclerosing chemical agents through the skin of the scrotum directly into the vas. Previous success in rats using 95% ethanol have been reported. This sutdy used 95% ethanol, 10% silver nitrate, 36% acetic acid, 3.6% formaldehyde, 3% sodium tetradecyl sulfate, 5% sodium morrhuate, 5% potassium permanganate, 3.6% formaldehyde in 90% ethanol, and for controls .9% sodium chloride. 25 or 50 mcl of the agent being tested was injected into each vas deferens of mature Sprague-Dawley rats. 2 weeks after treatment the rats were exposed to continuous mating. All of the rats treated with ethanol, silver nitrate, acetic acid, formaldehyde, and sodium tetradecyl sulfate have remained sterile for 8 months. 33% of those treated with potassium permanganate and 67% of those treated with sodium morrhuate have remained fertile. When the experiment was repeated in dogs using 95% ethanol, 10% silver nitrate, or 3.6% formaldehyde in 90% ethanol (100 or 500 mcl injected through the skin of the scrotum) the same obstructing sclerosis was found and a reduction in size of the vas was visible for approximately 2 cm. No sperm granulomas were found either grossly or microscopically. The method has not be used in humans but injections of methylene blue dye in alcohol have been made in several human autopsy specimens. The dye was contained within the sheath of the vas and penetrated the full thickness of the wall of the vas. The method is believed to be suitable for humans, would avoid post-surgical hemorrhage and infection, would require less equipment, and more rapid accomplishment and lower cost would follow if paramedical personnel could be taught the procudre in less developed countries for mass voluntary sterilizations. The results appear to be permanent. Surgical reversibility has not be determined.

Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes

NASA Astrophysics Data System (ADS)

Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A.; Cheng, Shuk Han; Sun, Dong

2016-04-01

Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.

Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes.

PubMed

Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A; Cheng, Shuk Han; Sun, Dong

2016-04-12

Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.

In Vivo Imaging of the Human Retinal Pigment Epithelial Mosaic Using Adaptive Optics Enhanced Indocyanine Green Ophthalmoscopy

PubMed Central

Tam, Johnny; Liu, Jianfei; Dubra, Alfredo; Fariss, Robert

2016-01-01

Purpose The purpose of this study was to establish that retinal pigment epithelial (RPE) cells take up indocyanine green (ICG) dye following systemic injection and that adaptive optics enhanced indocyanine green ophthalmoscopy (AO-ICG) enables direct visualization of the RPE mosaic in the living human eye. Methods A customized adaptive optics scanning light ophthalmoscope (AOSLO) was used to acquire high-resolution retinal fluorescence images of residual ICG dye in human subjects after intravenous injection at the standard clinical dose. Simultaneously, multimodal AOSLO images were also acquired, which included confocal reflectance, nonconfocal split detection, and darkfield. Imaging was performed in 6 eyes of three healthy subjects with no history of ocular or systemic diseases. In addition, histologic studies in mice were carried out. Results The AO-ICG channel successfully resolved individual RPE cells in human subjects at various time points, including 20 minutes and 2 hours after dye administration. Adaptive optics-ICG images of RPE revealed detail which could be correlated with AO dark-field images of the same cells. Interestingly, there was a marked heterogeneity in the fluorescence of individual RPE cells. Confirmatory histologic studies in mice corroborated the specific uptake of ICG by the RPE layer at a late time point after systemic ICG injection. Conclusions Adaptive optics-enhanced imaging of ICG dye provides a novel way to visualize and assess the RPE mosaic in the living human eye alongside images of the overlying photoreceptors and other cells. PMID:27564519

In Vivo Imaging of the Human Retinal Pigment Epithelial Mosaic Using Adaptive Optics Enhanced Indocyanine Green Ophthalmoscopy.

PubMed

Tam, Johnny; Liu, Jianfei; Dubra, Alfredo; Fariss, Robert

2016-08-01

The purpose of this study was to establish that retinal pigment epithelial (RPE) cells take up indocyanine green (ICG) dye following systemic injection and that adaptive optics enhanced indocyanine green ophthalmoscopy (AO-ICG) enables direct visualization of the RPE mosaic in the living human eye. A customized adaptive optics scanning light ophthalmoscope (AOSLO) was used to acquire high-resolution retinal fluorescence images of residual ICG dye in human subjects after intravenous injection at the standard clinical dose. Simultaneously, multimodal AOSLO images were also acquired, which included confocal reflectance, nonconfocal split detection, and darkfield. Imaging was performed in 6 eyes of three healthy subjects with no history of ocular or systemic diseases. In addition, histologic studies in mice were carried out. The AO-ICG channel successfully resolved individual RPE cells in human subjects at various time points, including 20 minutes and 2 hours after dye administration. Adaptive optics-ICG images of RPE revealed detail which could be correlated with AO dark-field images of the same cells. Interestingly, there was a marked heterogeneity in the fluorescence of individual RPE cells. Confirmatory histologic studies in mice corroborated the specific uptake of ICG by the RPE layer at a late time point after systemic ICG injection. Adaptive optics-enhanced imaging of ICG dye provides a novel way to visualize and assess the RPE mosaic in the living human eye alongside images of the overlying photoreceptors and other cells.

The influence of the oestrous cycle on the radiation response of solid tumours

NASA Astrophysics Data System (ADS)

Swann, Patricia R.

Oestrogen increases the transcription of nitric oxide synthase, thus increasing nitric oxide production, which can result in vasodilation of blood vessels. Fluctuating levels of oestrogen throughout the menstrual cycle has the potential to affect tumour blood flow. Variations of blood supply to a solid tumour can influence tumour oxygenation and subsequently the percentage of hypoxic cells. As hypoxic cells are more resistant to radiation than well-oxygenated cells, this could potentially affect the radiation response of the tumour. This project evaluated the impact of the oestrous stage on the radiation response of BCHT, RIF-1 and SCCvii tumours in syngeneic C3H mice. The oestrous cycle consists of the following stages, pro-oestrus, oestrus, metoestrus and dioestrus and each stage can be determined by the cellular composition of vaginal smears. The peak of oestrogen occurs in the ovulatory phase and a second smaller peak occurs in dioestrus. Subcutaneous tumour were treated at a volume of 200 - 250 mm3 with local irradiation of 10 Gy ionising radiation at different stages of the oestrous cycle. Tumours were excised either immediately or 24 hours after irradiation and disaggregated into a single cell suspension. Tumour cell survival was assessed by clonogenic assay of the excised tumour relative to untreated tumours excised at the corresponding oestrous stage. Tumours irradiated in oestrus consistently produced the lowest surviving fraction after immediate and delayed excision. Tumours irradiated in pro-oestrus and excised immediately after irradiation, showed a two-fold increase in surviving fraction compared to tumours irradiated in oestrus. The surviving fractions of tumours excised 24 hours after irradiation were less than for tumours excised immediately after irradiation. Surviving fractions of irradiated, clamped KHT tumours were independent of oestrous stage. To confirm that these oestrous stage dependent changes were due to changes in tumour perfusion, the degree of transient perfusion in the tumours was assessed. This used a fluorescent double-staining technique by intravenous injection of the fluorescent dyes Hoechst 33342 and diheptyloxacarbocyanine with a 20 minute interval between dye administrations. These dyes stain functional blood vessels and can be viewed under the fluorescent microscope. Regions of vasculature stained with both dyes indicate constant perfusion throughout the experiment, whereas only one dye indicates mismatch or transient perfusion. Tumour vasculature that experiences intermittent perfusion will result in areas of acute hypoxia that can impact on the radiation response of the tumour. The results shows that in oestrus, KHT and RIF-1 tumours showed the lowest proportion of transient perfusion, where as this oestrous stage produced the most mismatch perfusion in the SCCvii tumour. The metastatic spread of KHT tumour cells was influenced by the oestrous cycle. Fractionated irradiation of a primary tumour during metoestrus and dioestrus showed less tumour control by radiation when compared to tumours irradiated in oestrus. The intravenous injection of KHT tumour cells in oestrus and dioestrus also produced a less metastatic burden to the lungs than cells injected in pro-oestrus and metoestrus. The results of this project suggest that there are oestrous stage dependent effects that could alter the radiation response of tumours.

Diolistics: incorporating fluorescent dyes into biological samples using a gene gun

PubMed Central

O’Brien, John A.; Lummis, Sarah C.R.

2007-01-01

The hand-held gene gun provides a rapid and efficient method of incorporating fluorescent dyes into cells, a technique that is becoming known as diolistics. Transporting fluorescent dyes into cells has, in the past, used predominantly injection or chemical methods. The use of the gene gun, combined with the new generation of fluorescent dyes, circumvents some of the problems of using these methods and also enables the study of cells that have proved difficult traditionally to transfect (e.g. those deep in tissues and/or terminally differentiated); in addition, the use of ion- or metabolite-sensitive dyes provides a route to study cellular mechanisms. Diolistics is also ideal for loading cells with optical nanosensors – nanometre-sized sensors linked to fluorescent probes. Here, we discuss the theoretical considerations of using diolistics, the advantages compared with other methods of inserting dyes into cells and the current uses of the technique, with particular consideration of nanosensors. PMID:17945370

Targeted endomyocardial injections of therapeutic cells using x-ray fused with MRI guidance

NASA Astrophysics Data System (ADS)

Gutiérrez, Luis F.; de Silva, Ranil; McVeigh, Elliot R.; Ozturk, Cengizhan; Lederman, Robert J.

2006-03-01

The utility of X-ray fused with MRI (XFM) using external fiducial markers to perform targeted endomyocardial injections in infarcted hearts of swine was tested. Endomyocardial injections of feridex-labeled mesenchymal stromal cells (Fe-MSC) were performed in the previously infarcted hearts of 12 Yucatan miniswine (33-67 kg). Animals had pre-injection cardiac MRI, XFM-guided endomyocardial injection of Fe-MSC suspension spiked with tissue dye, and post-injection MRI. 24 hours later, after euthanasia, the hearts were excised, sliced and stained with TTC. During the injection procedure, operators were provided with 3D surfaces of endocardium, epicardium, myocardial wall thickness and infarct registered with live XF images to facilitate device navigation and choice of injection location. 130 injections were performed in hearts where diastolic wall thickness ranged from 2.6 to 17.7 mm. Visual inspection of the pattern of dye staining on TTC stained heart slices correlated (r=0.98) with XFM-derived injection locations mapped onto delayed hyperenhancement MRI and the susceptibility artifacts seen on the post-injection T2*-weighted gradient echo MRI. The in vivo target registration error was 3.17+/-2.61 mm (n=64) and 75% of injections were within 4 mm of the predicted location. 3D to 2D registration of XF and MR images using external fiducial markers enables accurate targeted endomyocardial injection in a swine model of myocardial infarction. The present data suggest that the safety and efficacy of this approach for performing targeted endomyocardial delivery should be evaluated further clinically.

Velocity, bathymetry, and transverse mixing characteristics of the Ohio River upstream from Cincinnati, Ohio, October 2004-March 2006

USGS Publications Warehouse

Koltun, G.F.; Ostheimer, Chad J.; Griffin, Michael S.

2006-01-01

Velocity, bathymetry, and transverse (cross-channel) mixing characteristics were studied in a 34-mile study reach of the Ohio River extending from the lower pool of the Captain Anthony Meldahl Lock and Dam, near Willow Grove, Ky, to just downstream from the confluence of the Licking and Ohio Rivers, near Newport, Ky. Information gathered in this study ultimately will be used to parameterize hydrodynamic and water-quality models that are being developed for the study reach. Velocity data were measured at an average cross-section spacing of about 2,200 feet by means of boat-mounted acoustic Doppler current profilers (ADCPs). ADCP data were postprocessed to create text files describing the three-dimensional velocity characteristics in each transect. Bathymetry data were measured at an average transect spacing of about 800 feet by means of a boat-mounted single-beam echosounder. Depth information obtained from the echosounder were postprocessed with water-surface slope and elevation information collected during the surveys to compute stream-bed elevations. The bathymetry data were written to text files formatted as a series of space-delimited x-, y-, and z-coordinates. Two separate dye-tracer studies were done on different days in overlapping stream segments in an 18.3-mile section of the study reach to assess transverse mixing characteristics in the Ohio River. Rhodamine WT dye was injected into the river at a constant rate, and concentrations were measured in downstream cross sections, generally spaced 1 to 2 miles apart. The dye was injected near the Kentucky shoreline during the first study and near the Ohio shoreline during the second study. Dye concentrations were measured along transects in the river by means of calibrated fluorometers equipped with flow-through chambers, automatic temperature compensation, and internal data loggers. The use of flow-through chambers permitted water to be pumped continuously out of the river from selected depths and through the fluorometer for measurement as the boat traversed the river. Time-tagged concentration readings were joined with horizontal coordinate data simultaneously captured from a differentially corrected Global Positioning System (GPS) device to create a plain-text, comma-separated variable file containing spatially tagged dye-concentration data. Plots showing the transverse variation in relative dye concentration indicate that, within the stream segments sampled, complete transverse mixing of the dye did not occur. In addition, the highest concentrations of dye tended to be nearest the side of the river from which the dye was injected. Velocity, bathymetry, and dye-concentration data collected during this study are available for Internet download by means of hyperlinks in this report. Data contained in this report were collected between October 2004 and March 2006.

Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

PubMed

Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

2017-10-01

In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear regression model. Analysis of variance was used to determine whether the absolute log proportional error differed by the intended injection volume. Interindividual and intraindividual deviation from the intended injection volume was also characterized. As the intended injection volumes decreased, the absolute log proportional injection volume error increased (analysis of variance, P < .0018). The exploratory analysis revealed no significant difference in the standard deviations of the log proportional errors for injection volumes between physicians and pediatric PACU nurses; however, the difference in absolute bias was significantly higher for nurses with a 2-sided significance of P = .03. Clinically significant dose variation occurs when injecting volumes ≤0.5 mL. Administering small volumes of medications may result in unintended medication administration errors.

Gap-Junctional communication between developing Drosophila muscles is essential for their normal development.

PubMed

Todman, M G; Baines, R A; Stebbings, L A; Davies, J A; Bacon, J P

1999-01-01

Recent experiments have demonstrated that a family of proteins, known as the innexins, are structural components of invertebrate gap junctions. The shaking-B (shak-B) locus of Drosophila encodes two members of this emerging family, Shak-B(lethal) and Shak-B(neural). This study focuses on the role of Shak-B gap junctions in the development of embryonic and larval muscle. During embryogenesis, shak-B transcripts are expressed in a subset of the somatic muscles; expression is strong in ventral oblique muscles (VO4-6) but only weak in ventral longitudinals (VL3 and 4). Carboxyfluorescein injected into VO4 of wild-type early stage 16 embryos spreads, via gap junctions, to label adjacent muscles, including VL3 and 4. In shak-B2 embryos (in which the shak-B(neural) function is disrupted), dye injected into VO4 fails to spread into other muscles. In the first instar larva, when dye coupling between muscles is no longer present, another effect of the shak-B2 mutation is revealed by whole-cell voltage clamp. In a calcium-free saline, only two voltage-activated potassium currents are present in wild-type muscles; a fast IA and a slow IK current. In shak-B2 larvae, these two currents are significantly reduced in magnitude in VO4 and 5, but remain normal in VL3. Expression of shak-B(neural) in a shak-B2 background fully rescues both dye coupling in embryonic muscle and whole-cell currents in first instar VO4 and 5. Our observations show that Shak-B(neural) is one of a set of embryonic gap-junction proteins, and that it is required for the normal temporal development of potassium currents in some larval muscles.

Data collection for a time-of-travel and dispersion study on the Coosa River near Childersburg, Alabama

USGS Publications Warehouse

Gardner, R.A.

1985-01-01

Approximately 2,300 dye-tracer samples were collected and analyzed during a 5-day time-of-travel study on a 23-mile reach of the Coosa River between Logan Martin and Lay dams near Childersburg, Alabama, October 27 to 31, 1984. Rhodamine WT was used as the tracer-dye. Unsteady flow conditions prevailed in the study reach. The rate of movement of the dye cloud between sampling cross sections ranged from 0.15 to 1.36 feet per second. The average rate of movement of the dye cloud between the injection cross section and the downstream sampling cross section was 0.42 foot per second. (USGS)

Voltage controlled nano-injection system for single-cell surgery

PubMed Central

Seger, R. Adam; Actis, Paolo; Penfold, Catherine; Maalouf, Michelle; Vilozny, Boaz; Pourmand, Nader

2015-01-01

Manipulation and analysis of single cells is the next frontier in understanding processes that control the function and fate of cells. Herein we describe a single-cell injection platform based on nanopipettes. The system uses scanning microscopy techniques to detect cell surfaces, and voltage pulses to deliver molecules into individual cells. As a proof of concept, we injected adherent mammalian cells with fluorescent dyes. PMID:22899383

Voltage controlled nano-injection system for single-cell surgery.

PubMed

Adam Seger, R; Actis, Paolo; Penfold, Catherine; Maalouf, Michelle; Vilozny, Boaz; Pourmand, Nader

2012-09-28

Manipulation and analysis of single cells is the next frontier in understanding processes that control the function and fate of cells. Herein we describe a single-cell injection platform based on nanopipettes. The system uses scanning microscopy techniques to detect cell surfaces, and voltage pulses to deliver molecules into individual cells. As a proof of concept, we injected adherent mammalian cells with fluorescent dyes.

Iodinated Al(III)-based phthalocyanines are promising sensitizers for dye-sensitized solar cells; a theoretical comparison between Zn(II), Mg(II), and Al(III)-based phthalocyanine sensitizers.

PubMed

Yang, Li-Na; Sun, Zhu-Zhu; Chen, Shi-Lu; Li, Ze-Sheng

2014-02-24

To design efficient dyes for dye-sensitized solar cells (DSSCs), using a Zn-coordinated phthalocyanine (TT7) as the prototype, a series of phthalocyanine dyes (Pcs) with different metal ions and peripheral/axial groups have been investigated by means of density functional theory (DFT) and time-dependent DFT (TDDFT) methods. Computational results show that the iodinated Al-based dye with a peripheral amino group (Al-I-NH2-Pc) exhibits the largest redshift in the maximum absorbance (λ(max)). In addition, Al-based dyes have appropriate energy-level arrangements of frontier orbitals to keep excellent balance between electron injection and regeneration of oxidized dyes. Further, it has been found that the intermolecular π-staking interaction in Al-I-Pc molecules is weaker than the other metal-based Pcs, which may effectively reduce dye aggregation on the semi-conductor surface. All these results suggest iodinated Al-based Pcs (Al-I-Pcs) to be potentially promising sensitizers in DSSCs. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

How Long Will I Be Blue? Prolonged Skin Staining Following Sentinel Lymph Node Biopsy Using Intradermal Patent Blue Dye

PubMed Central

Gumus, Metehan; Gumus, Hatice; Jones, Sue E; Jones, Peter A; Sever, Ali R; Weeks, Jennifer

2013-01-01

Summary Background Blue dye used for sentinel lymph node biopsy (SLNB) in breast cancer patients may cause prolonged skin discoloration at the site of injection. The aim of this study was to assess the duration of such skin discoloration. Patients and Methods 236 consecutive patients who had undergone breast conserving surgery and SLNB for breast cancer were reviewed prospectively from January 2007 to December 2009. Results Of the 236 patients, 2 had undergone bilateral surgery, and 41 had been examined in consecutive yearly reviews. Blue discoloration remained visible at the injection site after 12, 24, and > 36 months in 36.5, 23.6, and 8.6% of the patients, respectively. Conclusion The use of patent blue for identification of the sentinel lymph node in patients undergoing breast cancer surgery may result in prolonged discoloration of the skin at the injection site. PMID:24415970

The effects of Patent Blue dye on peripheral and cerebral oxyhaemoglobin saturations.

PubMed

Ishiyama, T; Kotoda, M; Asano, N; Ikemoto, K; Mitsui, K; Sato, H; Matsukawa, T; Sessler, D I

2015-04-01

We measured the effect of Patent Blue dye on oxyhaemoglobin saturations after injection into breast tissue: 40 women had anaesthesia for breast surgery maintained with sevoflurane or propofol (20 randomly allocated to each). Saturations were recorded with a digital pulse oximeter, in arterial blood samples and with a cerebral tissue oximeter before dye injection and 10, 20, 30, 40, 50, 60, 75, 90, 105 and 120 min afterwards. Patent Blue did not decrease arterial blood oxyhaemoglobin saturation, but it did reduce mean (SD) digital and cerebral oxyhaemoglobin saturations by 1.1 (1.1) % and 6.8 (7.0) %, p < 0.0001 for both. The falsely reduced oximeter readings persisted for at least 2 h. The mean (SD) intra-operative digital pulse oxyhaemoglobin readings were lower with sevoflurane than propofol, 97.8 (1.2) % and 98.8 (1.0) %, respectively, p < 0.0001. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Interfacial dynamics and solar fuel formation in dye-sensitized photoelectrosynthesis cells.

PubMed

Song, Wenjing; Chen, Zuofeng; Glasson, Christopher R K; Hanson, Kenneth; Luo, Hanlin; Norris, Michael R; Ashford, Dennis L; Concepcion, Javier J; Brennaman, M Kyle; Meyer, Thomas J

2012-08-27

Dye-sensitized photoelectrosynthesis cells (DSPECs) represent a promising approach to solar fuels with solar-energy storage in chemical bonds. The targets are water splitting and carbon dioxide reduction by water to CO, other oxygenates, or hydrocarbons. DSPECs are based on dye-sensitized solar cells (DSSCs) but with photoexcitation driving physically separated solar fuel half reactions. A systematic basis for DSPECs is available based on a modular approach with light absorption/excited-state electron injection, and catalyst activation assembled in integrated structures. Progress has been made on catalysts for water oxidation and CO(2) reduction, dynamics of electron injection, back electron transfer, and photostability under conditions appropriate for water splitting. With added reductive scavengers, as surrogates for water oxidation, DSPECs have been investigated for hydrogen generation based on transient absorption and photocurrent measurements. Detailed insights are emerging which define kinetic and thermodynamic requirements for the individual processes underlying DSPEC performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photosensitization of different ruthenium(II) complex dyes on TiO 2 for photocatalytic H 2 evolution under visible-light

NASA Astrophysics Data System (ADS)

Peng, Tianyou; Dai, Ke; Yi, Huabing; Ke, Dingning; Cai, Ping; Zan, Ling

2008-07-01

Hydrogen production over dye-sensitized Pt/P25 under visible-light irradiation was investigated by using methanol or TEOA as an electron donor. Ru 2(bpy) 4L 1-PF 6 shows the best photosensitization due to its largest conjugation system, widest range of visible-light and 'antenna effect' among the used three Ru(II)-bipyridyl dyes. Ru 2(bpy) 4L 1-PF 6 loosely linked with TiO 2 also exhibit more steady and higher increases in H 2 evolution upon prolonging the irradiation time than the tightly linked N719. The dynamic equilibrium between the linkage of ground dye and divorce of oxidized dye from TiO 2 can enhance the electron-injection and hinder the backward transfer, and then improve the H 2 evolution efficiency.

Phytoremediation in education: textile dye teaching experiments.

PubMed

Ibbini, Jwan H; Davis, Lawrence C; Erickson, Larry E

2009-07-01

Phytoremediation, the use of plants to clean up contaminated soil and water, has a wide range of applications and advantages, and can be extended to scientific education. Phytoremediation of textile dyes can be used as a scientific experiment or demonstration in teaching laboratories of middle school, high school and college students. In the experiments that we developed, students were involved in a hands-on activity where they were able to learn about phytoremediation concepts. Experiments were set up with 20-40 mg L(-1) dye solutions of different colors. Students can be involved in the set up process and may be involved in the experimental design. In its simplest forms, they use two-week-old sunflower seedlings and place them into a test tube of known volume of dye solution. Color change and/or dye disappearance can be monitored by visual comparison or with a spectrophotometer. Intensity and extent of the lab work depends on student's educational level, and time constraints. Among the many dyes tested, Evan's Blue proved to be the most readily decolorized azo dye. Results could be observed within 1-2 hours. From our experience, dye phytoremediation experiments are suitable and easy to understand by both college and middle school students. These experiments help visual learners, as students compare the color of the dye solution before and after the plant application. In general, simple phytoremediation experiments of this kind can be introduced in many classes including biology, biochemistry and ecological engineering. This paper presents success stories of teaching phytoremediation to middle school and college students.

Ultrafast recombination dynamics in dye-sensitized SnO 2/TiO 2 core/shell films

DOE PAGES

Gish, Melissa K.; Lapides, Alexander M.; Brennaman, M. Kyle; ...

2016-12-02

In dye-sensitized photoelectrosynthesis cells (DSPECs), molecular chromophores and catalysts are integrated on a semiconductor surface to perform water oxidation or CO 2 reduction after a series of light-induced electron transfer events. Unfortunately, recombination of the charge separated state (CSS) is competitive with productive catalysis. To overcome this major obstacle, implementation of photoanodic core/shell films within these devices improve electrochemical behavior and slow recombination through the introduction of an energetic barrier between the semiconductor core and oxidized species on the surface. In this study, interfacial dynamics are investigated in SnO 2/TiO 2 core/shell films derivatized with a Ru(II)-polypyridyl chromophore ([RuII(bpy)2(4,4'-(PO 3Hmore » 2) 2bpy)] 2+, RuP) using transient absorption methods. Electron injection from the chromophore into the TiO 2 shell occurs within a few picoseconds after photoexcitation. Loss of the oxidized dye through recombination occurs across time scales spanning 10 orders of magnitude. The majority (60%) of charge recombination events occur shortly after injection (τ = 220 ps), while a small fraction (≤20%) of the oxidized chromophores persists for milliseconds. The lifetime of long-lived CSS depends exponentially on shell thickness, suggesting that the injected electrons reside in the SnO 2 core and must tunnel through the TiO 2 shell to recombine with oxidized dyes. While the core/shell architecture extends the lifetime in a small fraction of the CSS, making water oxidation possible, the subnanosecond recombination process has profound implications for the overall efficiencies of DSPECs.« less

NIRF Optical/PET Dual-Modal Imaging of Hepatocellular Carcinoma Using Heptamethine Carbocyanine Dye

PubMed Central

Zhang, Caiqin; Zhao, Yong; Zhao, Ningning; Tan, Dengxu; Zhang, He; Chen, Xue; Zhang, Hai; An, Jiaze

2018-01-01

Combining near-infrared fluorescence (NIRF) and nuclear imaging techniques provides a novel approach for hepatocellular carcinoma (HCC) diagnosis. Here, we report the synthesis and characteristics of a dual-modality NIRF optical/positron emission tomography (PET) imaging probe using heptamethine carbocyanine dye and verify its feasibility in both nude mice and rabbits with orthotopic xenograft liver cancer. This dye, MHI-148, is an effective cancer-specific NIRF imaging agent and shows preferential uptake and retention in liver cancer. The corresponding NIRF imaging intensity reaches 109/cm2 tumor area at 24 h after injection in mice with HCC subcutaneous tumors. The dye can be further conjugated with radionuclide 68Ga (68Ga-MHI-148) for PET tracing. We applied the dual-modality methodology toward the detection of HCC in both patient-derived orthotopic xenograft (PDX) models and rabbit orthotopic transplantation models. NIRF/PET images showed clear tumor delineation after probe injection (MHI-148 and 68Ga-MHI-148). The tumor-to-muscle (T/M) standardized uptake value (SUV) ratios were obtained from PET at 1 h after injection of 68Ga-MHI-148, which was helpful for effectively capturing small tumors in mice (0.5 cm × 0.3 cm) and rabbits (1.2 cm × 1.8 cm). This cancer-targeting NIRF/PET dual-modality imaging probe provides a proof of principle for noninvasive detection of deep-tissue tumors in mouse and rabbit and is a promising technique for more accurate and early detection of HCC. PMID:29706843

Discovery of black dye crystal structure polymorphs: Implications for dye conformational variation in dye-sensitized solar cells

DOE PAGES

Cole, Jacqueline M.; Low, Kian Sing; Gong, Yun

2015-11-24

Here, we present the discovery of a new crystal structure polymorph (1) and pseudopolymorph (2) of the Black Dye, one of the world’s leading dyes for dye-sensitized solar cells, DSSCs (10.4% device performance efficiency). This reveals that Black Dye molecules can adopt multiple low-energy conformers. This is significant since it challenges existing models of the Black Dye···TiO 2 adsorption process that renders a DSSC working electrode; these have assumed a single molecular conformation that refers to the previously reported Black Dye crystal structure (3). The marked structural differences observed between 1, 2, and 3 make the need for modeling multiplemore » conformations more acute. Additionally, the ordered form of the Black Dye (1) provides a more appropriate depiction of its anionic structure, especially regarding its anchoring group and NCS bonding descriptions. The tendency toward NCS ligand isomerism, evidenced via the disordered form 2, has consequences for electron injection and electron recombination in Black Dye embedded DSSC devices. Dyes 2 and 3 differ primarily by the absence or presence of a solvent of crystallization, respectively; solvent environment effects on the dye are thereby elucidated. This discovery of multiple Black Dye conformers from diffraction, with atomic-level definition, complements recently reported nanoscopic evidence for multiple dye conformations existing at a dye···TiO 2 interface, for a chemically similar DSSC dye; those results emanated from imaging and spectroscopy, but were unresolved at the submolecular level. Taken together, these findings lead to the general notion that multiple dye conformations should be explicitly considered when modeling dye···TiO 2 interfaces in DSSCs, at least for ruthenium-based dye complexes.« less

Specific tumor labeling enhanced by polyethylene glycol linkage of near infrared dyes conjugated to a chimeric anti-carcinoembryonic antigen antibody in a nude mouse model of human pancreatic cancer

NASA Astrophysics Data System (ADS)

Maawy, Ali A.; Hiroshima, Yukihiko; Zhang, Yong; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

2014-10-01

Labeling of metastatic tumors can aid in their staging and resection of cancer. Near infrared (NIR) dyes have been used in the clinic for tumor labeling. However, there can be a nonspecific uptake of dye by the liver, lungs, and lymph nodes, which hinders detection of metastasis. In order to overcome these problems, we have used two NIR dyes (DyLight 650 and 750) conjugated to a chimeric anti-carcinoembryonic antigen antibody to evaluate how polyethylene glycol linkage (PEGylation) can improve specific tumor labeling in a nude mouse model of human pancreatic cancer. The conjugated PEGylated and non-PEGylated DyLight 650 and 750 dyes were injected intravenously into non-tumor-bearing nude mice. Serum samples were collected at various time points in order to determine serum concentrations and elimination kinetics. Conjugated PEGylated dyes had significantly higher serum dye concentrations than non-PEGylated dyes (p=0.005 for the 650 dyes and p<0.001 for the 750 dyes). Human pancreatic tumors subcutaneously implanted into nude mice were labeled with antibody-dye conjugates and serially imaged. Labeling with conjugated PEGylated dyes resulted in significantly brighter tumors compared to the non-PEGylated dyes (p<0.001 for the 650 dyes; p=0.01 for 750 dyes). PEGylation of the NIR dyes also decreased their accumulation in lymph nodes, liver, and lung. These results demonstrate enhanced selective tumor labeling by PEGylation of dyes conjugated to a tumor-specific antibody, suggesting their future clinical use in fluorescence-guided surgery.

Dye laser traveling wave amplifier

NASA Technical Reports Server (NTRS)

Davidson, F.; Hohman, J.

1984-01-01

A flashlamp pumped dye laser suitable for use as a single stage amplifier is described. Particular emphasis is placed on the efforts to increase output pulse energy and improve the temporal profile of the injected pulse. By using high power thin film polarizers, output energies reach from 4 to 45 mJ. Various dispersive elements are used to develop an amplified pulse with an extremely clean temporal profile.

[Acute blue urticaria following subcutaneous injection of patent blue dye].

PubMed

Hamelin, A; Vial-Dupuy, A; Lebrun-Vignes, B; Francès, C; Soria, A; Barete, S

2015-11-01

Patent blue (PB) is a lymphatic vessel dye commonly used in France for sentinel lymph node detection in breast cancer, and less frequently in melanoma, and which may induce hypersensitivity reactions. We report a case of acute blue urticaria occurring within minutes of PB injection. Ten minutes after PB injection for sentinel lymph node detection during breast cancer surgery, a 49-year-old woman developed generalised acute blue urticaria and eyelid angioedema without bronchospasm or haemodynamic disturbance, but requiring discontinuation of surgery. Skin testing using PB and the anaesthetics given were run 6 weeks after the episode and confirmed PB allergy. PB was formally contra-indicated. Immediate hypersensitivity reactions to PB have been reported for between 0.24 and 2.2% of procedures. Such reactions are on occasion severe, chiefly involving anaphylactic shock. Two mechanisms are probably associated: non-specific histamine release and/or an IgE-mediated mechanism. Skin tests are helpful in confirming the diagnosis of PB allergy. Blue acute urticaria is one of the clinical manifestations of immediate hypersensitivity reactions to patent blue dye. Skin tests must be performed 6 weeks after the reaction in order to confirm the diagnosis and formally contra-indicate this substance. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Extraction and Quantitation of FD&C Red Dye #40 from Beverages Containing Cranberry Juice: A College-Level Analytical Chemistry Experiment

ERIC Educational Resources Information Center

Rossi, Henry F., III; Rizzo, Jacqueline; Zimmerman, Devon C.; Usher, Karyn M.

2012-01-01

A chemical separation experiment can be an interesting addition to an introductory analytical chemistry laboratory course. We have developed an experiment to extract FD&C Red Dye #40 from beverages containing cranberry juice. After extraction, the dye is quantified using colorimetry. The experiment gives students hands-on experience in using solid…

Rapid and efficient detection of single chromophore molecules in aqueous solution

NASA Astrophysics Data System (ADS)

Li, Li-Qiang; Davis, Lloyd M.

1995-06-01

The first experiments on the detection of single fluorescent molecules in a flowing stream of an aqueous solution with high total efficiency are reported. A capillary injection system for sample delivery causes all the dye molecules to pass in a diffusion-broadened stream within a fast-moving sheath flow, through the center of the tightly focused laser excitation beam. Single-molecule detection with a transit time of approximately 1 ms is accomplished with a high-quantum-efficiency single-photon avalanche diode and a low dead-time time-gating circuit for discrimination of Raman-scattered light from the solvent.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

PubMed Central

Pesek, Sarah; Ashikaga, Taka; Krag, Lars Erik; Krag, David

2012-01-01

Background/Purpose In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate. Methods We found 3588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published. Results There was significant variation in the false-negative rate over time with a trend to higher rates over time. There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant. This meta-analysis also indicates a significant change over time in the false-negative rate. Discussion/Conclusions The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control. PMID:22569745

Polyethylene Glycol (PEG) Linked to Near Infrared (NIR) Dyes Conjugated to Chimeric Anti-Carcinoembryonic Antigen (CEA) Antibody Enhances Imaging of Liver Metastases in a Nude-Mouse Model of Human Colon Cancer

PubMed Central

Maawy, Ali A.; Hiroshima, Yukihiko; Zhang, Yong; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

2014-01-01

We report here that polyethylene glycol (PEG) linked to near infrared dyes conjugated to chimeric mouse-human anti-carcinoembryonic antigen (CEA) antibody greatly improves imaging of liver metastases in a nude mouse model of colon-cancer experimental metastases. PEGylated and non-PEGylated DyLight 650 and 750 dyes were conjugated to the chimeric anti-CEA antibody. The dyes were initially injected intravenously into nude mice without tumors. Tissue biodistribution was determined by tissue sonication and analyzing tissue dye concentration profiles over time. PEGylated dyes had significantly lower accumulation in the liver (p = 0.03 for the 650 dyes; p = 0.002 for the 750 dyes) compared to non-PEGylated dyes. In an experimental liver metastasis model of HT-29 colon cancer, PEGylated dyes conjugated to the anti-CEA antibody showed good labeling of metastatic tumors with high contrast between normal and malignant tissue which was not possible with the non-PEGylated dyes since there was so much non-specific accumulation in the liver. PEGylation of the DyLight 650 and 750 NIR dyes significantly altered tissue biodistribution, allowing brighter tissue labeling, decreased accumulation in normal organs, particularly the liver. This enabled high fidelity and high contrast imaging of liver metastases. PMID:24859320

Flow visualization in long neck Helmholtz resonators with grazing flow

NASA Technical Reports Server (NTRS)

Baumeister, K. J.; Rice, E. J.

1976-01-01

Both oscillating and steady flows were applied to a single plexiglass resonator cavity with colored dyes injected in both the orifice and grazing flow field to record the motion of the fluid. For oscillatory flow, the instantaneous dye streamlines were similar for both the short and long-neck orifices. The orifice flow blockage appears to be independent of orifice length for a fixed amplitude of flow oscillation and magnitude of the grazing flow. The steady flow dye studies showed that the acoustic and steady flow resistances do not necessarily correspond for long neck orifices.

Organic photosensitizers with a heteroleptic dual donor for dye-sensitized solar cells.

PubMed

Kim, Joo Young; Kim, Young Sik

2012-04-01

Using DFT and TDDFT calculations, we investigated the substitution effect in the electronic and optical properties of dye sensitizers with a dual donor composed of triphenylamine and/or indoline moieties. Due to replacement with the dual donor moieties, the HOMO levels were split into HOMO and HOMO - 1 levels, and the bandgaps between the HOMO and LUMO levels decreased, leading to the creation of bathochromically extended absorption spectra. Nearly degenerated splitting of the HOMO levels resulted from the similarity of the electronic structure between the HOMO and the HOMO - 1 levels, delocalized over both dual-donor moieties, when replacing the dual donors. It was shown that the additional electron-donating group creates an additional absorption band and causes a cascading two-electron process aiding the charge separation process. Owing to a more panchromatic attribute, easier energy transfer and feasible retardation of the recombination between the injected electrons and the electrolyte, it is expected that dyeTI will show better performance than the other dyes (dyeT dyeTT and dyeIT) as denoted here in terms of the conversion efficiency of dye-sensitized solar cells (DSSCs). This work presents the probable benefits of dye sensitizers with dual-donor moieties and provides insight into the development of more efficient dye sensitizers for DSSCs through modification of the Frontier molecular orbitals.

Insights into the Mechanism of a Covalently Linked Organic Dye–Cobaloxime Catalyst System for Dye‐Sensitized Solar Fuel Devices

PubMed Central

Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández‐Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif

2017-01-01

Abstract A covalently linked organic dye–cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye‐sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time‐resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye–catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye–catalyst system on the photocathode is proposed on the basis of this study. PMID:28338295

Rhodamine-Injected Eggs to Photographically Identify Small Nest-Predators

Treesearch

Thomas J. Maier; Richard M. DeGraaf

2000-01-01

Photographs that clearly disclose avian-nest predators are difficult to obtain, particularly when predators are small and exhibit subtle depredatory behavior. We exposed House Sparrow (Passer domesticus) eggs injected with Rhodamine B dye in camera-monitored ground nests for 12-d periods at 76 sites within mixed-hardwood forest stands in central...

Studies on the use of power ultrasound in leather dyeing.

PubMed

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2003-03-01

Uses of power ultrasound for acceleration/performing the chemical as well as physical processes are gaining importance. In conventional leather processing, the diffusion of chemicals through the pores of the skin/hide is achieved by the mechanical agitation caused by the paddle or drumming action. In this work, the use of power ultrasound in the dyeing of leather has been studied with the aim to improve the exhaustion of dye for a given processing time, to reduce the dyeing time and to improve the quality of dyed leather. The effect of power ultrasound in the dyeing of full chrome cow crust leather in a stationary condition is compared with dyeing in the absence of ultrasound as a control experiment both in a stationary as well as conventional drumming condition. An ultrasonic cleaner (150 W and 33 kHz) was used for the experiments. Actual power dissipated into the system was calculated from the calorimetric measurement. Experiments were carried out with variation in type of dye, amount of dye offer, temperature and time. The results show that there is a significant improvement in the percentage exhaustion of dye due to the presence of ultrasound, when compared to dyeing in absence of ultrasound. Experiments on equilibrium dye uptake carried out with or without ultrasound suggest that ultrasound help to improve the kinetics of leather dyeing. The results indicate that leathers dyed in presence of ultrasound have higher colour values, better dye penetration and fastness properties compared to control leathers. The physical testing results show that strength properties of the dyed leathers are not affected due to the application of ultrasound under the given process conditions. Apparent diffusion coefficient during the initial stage of dyeing process, both in presence and in absence of ultrasound was calculated. The values show that ultrasound helps in improving the apparent diffusion coefficient more for the difficult dyeing conditions such as in the case of metal-complex dyes having bigger aggregate size compared to less difficult dyeing conditions.

Chronic cranial window with access port for repeated cellular manipulations, drug application, and electrophysiology

PubMed Central

Roome, Christopher J.; Kuhn, Bernd

2014-01-01

Chronic cranial windows have been instrumental in advancing optical studies in vivo, permitting long-term, high-resolution imaging in various brain regions. However, once a window is attached it is difficult to regain access to the brain under the window for cellular manipulations. Here we describe a simple device that combines long term in vivo optical imaging with direct brain access via glass or quartz pipettes and metal, glass, or quartz electrodes for cellular manipulations like dye or drug injections and electrophysiological stimulations or recordings while keeping the craniotomy sterile. Our device comprises a regular cranial window glass coverslip with a drilled access hole later sealed with biocompatible silicone. This chronic cranial window with access port is cheap, easy to manufacture, can be mounted just as the regular chronic cranial window, and is self-sealing after retraction of the pipette or electrode. We demonstrate that multiple injections can be performed through the silicone port by repetitively bolus loading calcium sensitive dye into mouse barrel cortex and recording spontaneous cellular activity over a period of weeks. As an example to the extent of its utility for electrophysiological recording, we describe how simple removal of the silicone seal can permit patch pipette access for whole-cell patch clamp recordings in vivo. During these chronic experiments we do not observe any infections under the window or impairment of animal health. PMID:25426027

Remedial Amendment Delivery near the Water Table Using Shear Thinning Fluids: Experiments and Numerical Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oostrom, Martinus; Truex, Michael J.; Vermeul, Vincent R.

2014-08-19

The use of shear thinning fluids (STFs) containing xanthan is a potential enhancement for emplacing a solute amendment near the water table and within the capillary fringe. Most research to date related to STF behavior has involved saturated and confined conditions. A series of flow cell experiments were conducted to investigate STF emplacement in variable saturated homogeneous and layered heterogeneous systems. Besides flow visualization using dyes, amendment concentrations and pressure data were obtained at several locations. The experiments showed that injection of STFs considerably improved the subsurface distribution near the water table by mitigating preferential flow through higher permeability zonesmore » compared to no-polymer injections. The phosphate amendment migrated with the xanthan SFT without retardation. Despite the high viscosity of the STF, no excessive mounding or preferential flow were observed in the unsaturated zone. The STOMP simulator was able to predict the experimentally observed fluid displacement and amendment concentrations reasonably well. Cross flow between layers could be interpreted as the main mechanism to transport STFs into lower permeability layers based on the observed pressure gradient and concentration data in layers of differing hydraulic conductivity.« less

Piper Ornatum and Piper Betle as Organic Dyes for TiO2 and SnO2 Dye Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Hayat, Azwar; Putra, A. Erwin E.; Amaliyah, Novriany; Hayase, Shuzi; Pandey, Shyam. S.

2018-03-01

Dye sensitized solar cell (DSSC) mimics the principle of natural photosynthesis are now currently investigated due to low manufacturing cost as compared to silicon based solar cells. In this report, we utilized Piper ornatum (PO) and Piper betle (PB) as sensitizer to fabricate low cost DSSCs. We compared the photovoltaic performance of both sensitizers with Titanium dioxide (TiO2) and Tin dioxide (SnO2) semiconductors. The results show that PO and PB dyes have higher Short circuit current (Jsc) when applied in SnO2 compared to standard TiO2 photo-anode film even though the Open circuit voltage (Voc) was hampered on SnO2 device. In conclusion, from the result, higher electron injections can be achieved by choosing appropriate semiconductors with band gap that match with dyes energy level as one of strategy for further low cost solar cell.

Dye-dispersion study at proposed pumped-storage project on Hudson River at Cornwall, New York

USGS Publications Warehouse

Dunn, Bernard; Gravlee, George C.

1978-01-01

Data were collected during a dye-dispersion study on a 6-mile, tide-affected reach of the Hudson River near the proposed Cornwall Pumped Storage Project on September 21-22, 1977. The results indicated that complete mixing did not occur during the first tidal cycle but was complete after two or more cycles. The fluorometric dye-tracing procedure was used to determine the dispersion characteristics of the water mass. Rhodamine WT dye, 20-percent solution, was continuously injected on the west side of the river throughout an ebb tide, and its movement was monitored during a 30-hour period. Samples were collected both individually and continuously. Automatic dye samplers were used at selected cross sections near each bank. Bathymetric measurements were made at eight cross sections between Newburgh and West Point to determine the depths. (Woodard-USGS)

Lateral Mixing DRI Analysis: Submesoscale Water-Mass Spectra

DTIC Science & Technology

2013-09-30

program to determine submesoscale variability in the Sargasso Sea under weak-to-moderate mesoscale conditions. Two sites were examined, a quiet site...anomalies and dye streaks. Hammerhead carries finescale Sea -Bird sensors for temperature, conductivity and pressure as well as Chelsea and WetLab...m of dye-injection target densities. They were embedded in 35-km towyo grid surveys by Craig Lee’s Triaxus and 15-km butterfly surveys by Jody

New observations on endometrial physiology after transcervical injection of methylene blue dye.

PubMed

Marconi, Guillermo; Vilela, Martín; Quintana, Ramiro; Diradourián, Marco; Young, Edgardo; Sueldo, Carlos

2004-12-01

We describe the in vivo features of endometrium stained with methylene blue dye and observed via microhysteroscopy, showing the patterns of endometrial glands and superficial cell changes during the midproliferative, periovulatory, and midluteal phases. These preliminary observations have allowed us to identify a series of changes occurring in the different phases of the ovulatory cycle of potential value in reproductive medicine for specific groups of infertile patients.

Near-infrared indocyanine dye permits real-time characterization of both venous and lymphatic circulation

NASA Astrophysics Data System (ADS)

Kurahashi, Toshikazu; Iwatsuki, Katsuyuki; Onishi, Tetsuro; Arai, Tetsuya; Teranishi, Katsunori; Hirata, Hitoshi

2016-08-01

We investigated the optical properties of a near-infrared (NIR) fluorochrome, di-β-cyclodextrin-binding indocyanine derivative (TK-1), and its pharmacokinetic differences with indocyanine green (ICG). TK-1 was designed to have hydrophilic cyclodextrin molecules and, thus, for higher water solubility and smaller particle sizes than the plasma protein-bound ICG. We compared optical properties such as the absorption and fluorescence spectra, quantum yield, and photostability between both dyes in vitro. In addition, we subcutaneously injected a 1 mM solution of TK-1 or ICG into the hind footpad of rats and observed real-time NIR fluorescence intensities in their femoral veins and accompanying lymphatics at the exposed groin site to analyze the dye pharmacokinetics. These optical experiments demonstrated that TK-1 has high water solubility, a low self-aggregation tendency, and high optical and chemical stabilities. Our in vivo imaging showed that TK-1 was transported via peripheral venous flow and lymphatic flow, whereas ICG was drained only through lymphatics. The results of this study showed that lymphatic and venous transport can be differentially regulated and is most likely influenced primarily by particle size, and that TK-1 can enable real-time NIR fluorescence imaging of whole fluids and solute movement via both microvessels and lymphatics, which conventional ICG cannot achieve.

Turbulent acidic jets and plumes injected into an alkaline environment

NASA Astrophysics Data System (ADS)

Ulpre, Hendrik

2012-11-01

The characteristics of a strong acidic turbulent jet or plume injected into an alkaline environment comprising of a weak/strong base are examined theoretically and experimentally. A chemistry model is developed to understand how the pH of a fluid parcel of monoprotic acid changes as it is diluted and reacts with the ambient fluid. A standard fluid model, based on a top-hat model for acid concentration and velocity is used to express how the dilution of acid varies with distance from the point of discharge. These models are applied to estimate the point of neutralisation and the travel time with distance within the jet/plume. An experimental study was undertaken to test the theoretical results. These experiments involved injecting jets or vertical plumes of dilute nitric acid into a large tank containing a variety of base salts dissolved in water. The injected fluid contained litmus indicator dye which showed a change in colour from red to blue close to the point of neutralisation. In order to obtain a range of neutralisation distances, additional basic salts were added to the water to increase its pH buffering capacity. The results are applied to discuss the environmental implications of an acidic jet/plume injected into the sea off the South East coast of Great Britain.

Gene Delivery to Postnatal Rat Brain by Non-ventricular Plasmid Injection and Electroporation

PubMed Central

Molotkov, Dmitry A.; Yukin, Alexey Y.; Afzalov, Ramil A.; Khiroug, Leonard S.

2010-01-01

Creation of transgenic animals is a standard approach in studying functions of a gene of interest in vivo. However, many knockout or transgenic animals are not viable in those cases where the modified gene is expressed or deleted in the whole organism. Moreover, a variety of compensatory mechanisms often make it difficult to interpret the results. The compensatory effects can be alleviated by either timing the gene expression or limiting the amount of transfected cells. The method of postnatal non-ventricular microinjection and in vivo electroporation allows targeted delivery of genes, siRNA or dye molecules directly to a small region of interest in the newborn rodent brain. In contrast to conventional ventricular injection technique, this method allows transfection of non-migratory cell types. Animals transfected by means of the method described here can be used, for example, for two-photon in vivo imaging or in electrophysiological experiments on acute brain slices. PMID:20972387

Precise identification and manipulation of adsorption geometry of donor-π-acceptor dye on nanocrystalline TiO₂ films for improved photovoltaics.

PubMed

Zhang, Fan; Ma, Wei; Jiao, Yang; Wang, Jingchuan; Shan, Xinyan; Li, Hui; Lu, Xinghua; Meng, Sheng

2014-12-24

Adsorption geometry of dye molecules on nanocrystalline TiO2 plays a central role in dye-sensitized solar cells, enabling effective sunlight absorption, fast electron injection, optimized interface band offsets, and stable photovoltaic performance. However, precise determination of dye binding geometry and proportion has been challenging due to complexity and sensitivity at interfaces. Here employing combined vibrational spectrometry and density functional calculations, we identify typical adsorption configurations of widely adopted cyanoacrylic donor-π bridge-acceptor dyes on nanocrystalline TiO2. Binding mode switching from bidentate bridging to hydrogen-bonded monodentate configuration with Ti-N bonding has been observed when dye-sensitizing solution becomes more basic. Raman and infrared spectroscopy measurements confirm this configuration switch and determine quantitatively the proportion of competing binding geometries, with vibration peaks assigned using density functional theory calculations. We further found that the proportion of dye-binding configurations can be manipulated by adjusting pH value of dye-sensitizing solutions. Controlling molecular adsorption density and configurations led to enhanced energy conversion efficiency from 2.4% to 6.1% for the fabricated dye-sensitized solar cells, providing a simple method to improve photovoltaic performance by suppressing unfavorable binding configurations in solar cell applications.

Performance enhancement of dye-sensitized solar cells (DSSCs) using a natural sensitizer

NASA Astrophysics Data System (ADS)

Arifin, Zainal; Soeparman, Sudjito; Widhiyanuriyawan, Denny; Sutanto, Bayu; Suyitno

2017-01-01

Dye-sensitized solar cells (DSSCs) based on natural sensitizers have become a topic of significant research because of their urgency and importance in the energy conversion field and the following advantages: ease of fabrication, low-cost solar cell, and usage of nontoxic materials. The natural sensitizer in DSSCs is responsible for the absorption of light as well as the injection of charges to the conduction band of the semiconductor such as TiO2 nanoparticles. In this study, the chlorophyll extracted from papaya leaves was used as a natural sensitizer. Dye molecules were adsorbed by TiO2 nanoparticle surfaces when submerged in the dye solution for 24 h. The concentration of the dye solution influences both the amount of dye loading and the DSSC performance. The amount of adsorbed dye molecules by TiO2 nanoparticle was calculated using a desorption method. As the concentration of dye solution was increased, the dye loading capacity and power conversion efficiency increased. Above 90 mM dye solution concentration, however, the DSSC efficiency decreased because dye precipitated on the TiO2 nanostructure. These characteristics of DSSCs were analyzed under the irradiation of 100 mW/cm2. The best performance of DSSCs was obtained at 90 mM dye solution, with the values of Voc, Jsc, FF, and efficiency of DSSCs being 0.561 V, 0.402 mA/cm2, 41.65%, and 0.094%, respectively.

Is a Retrolaminar Approach to the Thoracic Paravertebral Space Possible?: A Human Cadaveric Study.

PubMed

Sabouri, A Sassan; Crawford, Lane; Bick, Sarah K; Nozari, Ala; Anderson, Thomas A

2018-06-19

The retrolaminar block (RB) is used for truncal analgesia, but its mechanism of neural blockade remains obscure. We sought to learn the pattern of local anesthetic spread after thoracic RB using cadaveric models. In 8 fresh cadavers, an ultrasound-guided T4 RB was performed with 20 mL of methylene blue 1% and bupivacaine 0.5%. For comparison, an RB at T9 in 1 cadaver and a T4 thoracic paravertebral block in another cadaver were performed. Subsequently, posterior and anterior thoracic dissections were performed to examination where the dye spread. After T4 RB, dye was noted to spread in the ipsilateral retrolaminar plane (all 8 cadavers, median cephalad spread 3.5 cm, caudad spread 10.7 cm, lateral spread 2.5 cm), the contralateral retrolaminar plane (6 cadavers), the paravertebral space (5 cadavers, median of 3 segments, T3-T5), the intercostal space (5 cadavers, median of 3.5 cm laterally), the T4 epidural space (6 cadavers), and the intervertebral foramina (4 cadavers, median of 2 segments, T4-T5). After T9 retrolaminar injection, dye was noted in the ipsilateral retrolaminar plane (5.5 cm cephalad, 13.5 cm caudad, and 2.5 cm lateral), the contralateral retrolaminar plane, and the epidural space. Dye after T4 traditional paravertebral block spread to T1-T6 paravertebral space with 15-cm lateral spread. Injectate spread to the paravertebral space, epidural space, intercostal space, and intervertebral foramina is possible in the RB but is quite variable. In comparison to the thoracic paravertebral block, injectate spread within the paravertebral space is more limited.

Time of travel and dispersion in a selected reach of Roberts Creek, Clayton County, Iowa

USGS Publications Warehouse

Kolpin, D.W.; Kalkhoff, S.J.

1992-01-01

Time of travel was determined by dye tracing, using rhodamine WT as the tracer. One dyeinjection site and three sampling sites were used to measure time of travel. Two dye-tracing tests were conducted at discharges having flow-duration values of 48 and 80 percent. The discharges at the time of the two dye-tracing tests approximated medium- and low-flow conditions. The average stream velocity in the study area was 0.23 foot per second during medium-flow conditions, March 20 to 22,1990, and 0.07 foot per second during low-flow conditions, April 30 to May 12, 1990. The injected dye dispersed in a plume that lasted about 18 hours during medium flow and about 64 hours during low flow at the downstream site.

Quantum dynamical simulation of photoinduced electron transfer processes in dye-semiconductor systems: theory and application to coumarin 343 at TiO₂.

PubMed

Li, Jingrui; Kondov, Ivan; Wang, Haobin; Thoss, Michael

2015-04-10

A recently developed methodology to simulate photoinduced electron transfer processes at dye-semiconductor interfaces is outlined. The methodology employs a first-principles-based model Hamiltonian and accurate quantum dynamics simulations using the multilayer multiconfiguration time-dependent Hartree approach. This method is applied to study electron injection in the dye-semiconductor system coumarin 343-TiO2. Specifically, the influence of electronic-vibrational coupling is analyzed. Extending previous work, we consider the influence of Dushinsky rotation of the normal modes as well as anharmonicities of the potential energy surfaces on the electron transfer dynamics.

Tuning pentacene based dye-sensitized solar cells.

PubMed

Kunzmann, Andreas; Gruber, Marco; Casillas, Rubén; Tykwinski, Rik R; Costa, Rubén D; Guldi, Dirk M

2018-05-10

We report on the synthesis, as well as photophysical and electrochemical characterization of a new family of pentacene derivatives, which are applied in n-type dye-sensitized solar cells (DSSCs). As far as the molecular structure of the pentacene is concerned, the synthetic design focuses on cyano acrylic tethered at the 13-position of the pentacene chromophore. The electrolyte composition features increasing amounts of Li+ ions as an additive. In general, the increase of Li+ concentrations extrinsically reduces the quasi Fermi level of the photoanode and as such facilitates the electron injection process. We demonstrate that pentacene derivatives give rise to a unique charge injection process, which is controlled by the positioning of the quasi Fermi level energies as a function of the Li+ concentration. As a result of the enhanced charge injection, device efficiencies as high as 1.5% are achieved, representing a 3-fold increase from previously reported efficiencies in pentacene-based DSSCs. These findings are supported by device analysis in combination with transient absorption and electrochemical impedance spectroscopy assays.

Ultrasound assisted extraction of natural dye from jackfruit's wood (Artocarpus heterophyllus): The effect of ethanol concentration as a solvent

NASA Astrophysics Data System (ADS)

Febriana, Ike Dayi; Gala, Selfina; Mahfud, Mahfud

2017-05-01

Azo dye are synthetic organic dyes which has an azo group (- N = N -) as chromophore. Azo dye is resistand to decomposition process and harmfull for the environment and human being. Natural dye can be used as substitution of azo dye at textile industry. Natural dye are eco - friendly and can be applied for dyeing of fibrous material. Natural dye can be obtained from natural origin such as leaves, wood, or roots. The wood of jackfruit (Artocarpus heterophyllus) can used as natural source of natural dye. Ultrasound assisted extraction (UAE) is a new method that can be used to extract natural dye from jackfruit's wood. The aim of this research are to study about influence of ethanol concentration as solvent and extraction kinetic. Jackfruit's wood dust from sawmill used for the experimentation were sifted by sieve 35 mesh. Ethanol 96% used as solvent of this experiment and varied the concentration in volume to volume ratio (v/v). Experiment were carried out from 20 to 50 minutes. The result of this experiment shows that ethanol concentration influenced yield of extraction from jackfruit's wood. Concentration of ethanol will be affected polarity of solvent. The Peleg model was used to describe about kinetic model of natural dye extraction. Value of k1 and k2 constant are 0.003835 and 0.04186 respectively.

TGF-beta1 inhibits Cx43 expression and formation of functional syncytia in cultured smooth muscle cells from human detrusor.

PubMed

Neuhaus, Jochen; Heinrich, Marco; Schwalenberg, Thilo; Stolzenburg, Jens-Uwe

2009-02-01

Human detrusor smooth muscle cells (hBSMCs) are coupled by connexin 43 (Cx43)-positive gap junctions to form functional syncytia. Gap junctional communication likely is necessary for synchronised detrusor contractions and is supposed to be altered in voiding disturbances. Other authors have shown that the pleiotropic cytokine TGF-beta1 upregulates Cx43 expression in human aortic smooth muscle cells. In this study, we examined the TGF-beta1 effects on Cx43 expression in cultured hBSMCs. hBSMC cultures, established from patients undergoing cystectomy, were treated with recombinant human TGF-beta1. Cx43 expression was then examined by Western blotting, real-time PCR, and immunocytochemistry. Dye-injection experiments were used to study the size of functional syncytia. Dye-coupling experiments revealed stable formation of functional syncytia in passaged cell cultures (P1-P4). Stimulation with TGF-beta1 led to significant reduction of Cx43 immunoreactivity and coupling. Cx43 protein expression was significantly downregulated and Cx43 mRNA was only 30% of the control level. Interestingly, low phosphorylation species of Cx43 were particularly affected. Our experiments demonstrated a significant down regulation of connexin 43 by TGF-beta1 in cultured hBSMCs. These findings support the view that TGF-beta1 is involved in the pathophysiology of urinary bladder dysfunction.

Preclinical evaluation of a novel cyanine dye for tumor imaging with in vivo photoacoustic imaging.

PubMed

Temma, Takashi; Onoe, Satoru; Kanazaki, Kengo; Ono, Masahiro; Saji, Hideo

2014-09-01

Photoacoustic imaging (PA imaging or PAI) has shown great promise in the detection and monitoring of cancer. Although nanocarrier-based contrast agents have been studied for use in PAI, small molecule contrast agents are required due to their ease of preparation, costeffectiveness, and low toxicity. Here, we evaluated the usefulness of a novel cyanine dye IC7-1-Bu as a PAI contrast agent without conjugated targeting moieties for in vivo tumor imaging in a mice model. Basic PA characteristics of IC7-1-Bu were compared with indocyanine green (ICG), a Food and Drug Administration approved dye, in an aqueous solution. We evaluated the tumor accumulation profile of IC7-1-Bu and ICG by in vivo fluorescence imaging. In vivo PAI was then performed with a photoacoustic tomography system 24 and 48 h after intravenous injection of IC7-1-Bu into tumor bearing mice. IC7-1-Bu showed about a 2.3-fold higher PA signal in aqueous solution compared with that of ICG. Unlike ICG, IC7-1-Bu showed high tumor fluorescence after intravenous injection. In vivo PAI provided a tumor to background PA signal ratio of approximately 2.5 after intravenous injection of IC7-1-Bu. These results indicate that IC7-1-Bu is a promising PAI contrast agent for cancer imaging without conjugation of targeting moieties.

Inclusion of aggregation effect to evaluate the performance of organic dyes in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Sun, Kenan; Zhang, Weiyi; Heng, Panpan; Wang, Li; Zhang, Jinglai

2018-05-01

Two new indoline-based D-A-π-A dyes, D3F and D3F2 (see Scheme 1), are developed on the basis of the reported D3 by insertion of one or two F atoms on benzothiadiazole group. Our central aim is to explore high-efficiency organic dyes applied in dye-sensitized solar cells by inclusion of a simple group rather than by employment of new complicated groups. The performance of two new designed organic dyes, D3F and D3F2, is compared with that of D3 from various aspects including absorption spectrum, light harvesting efficiency, driving force, and open-circuit voltage. Besides the isolated dye, the interfacial property between dye and TiO2 surface is studied. D3F and D3F2 do not show absolute superiority than D3 not only for the isolated dyes but also for the monomeric adsorption system. However, D3F and D3F2 would effectively reduce the influence of aggregation resulting in the much smaller intermolecular electronic coupling. Although the aggregation has attracted much attention recently, it is studied alone in most of studies. To comprehensively evaluate the performance of dye-sensitized solar cells, it is necessary to consider aggregation along with electron injection time from dye into TiO2 rather than only static items, such as, band gap and absorption region.

Travel times, streamflow velocities, and dispersion rates in the Missouri River upstream from Canyon Ferry Lake, Montana

USGS Publications Warehouse

Whiteman, Aroscott

2012-01-01

In 2010, the U.S. Geological Survey, in cooperation with the Montana Department of Environmental Quality, initiated a dye-tracer study to determine travel times, streamflow velocities, and longitudinal dispersion rates for the Missouri River upstream from Canyon Ferry Lake. For this study, rhodamine WT (RWT) dye was injected at two locations, Missouri River Headwaters State Park in early September and Broadwater-Missouri Dam (Broadwater Dam) in late August 2010. Dye concentrations were measured at three sites downstream from each dye-injection location. The study area was a 41.2-mile reach of the Missouri River from Trident, Montana, at the confluence of the Jefferson, Madison, and Gallatin Rivers (Missouri River Headwaters) at river mile 2,319.40 downstream to the U.S. Route 12 Bridge (Townsend Bridge), river mile 2,278.23, near Townsend, Montana. Streamflows were reasonably steady and ranged from 3,070 to 3,700 cubic feet per second. Mean velocities were calculated for each subreach between measurement sites for the leading edge, peak concentration, centroid, and trailing edge at 10 percent of the peak concentration of the dye plume. Calculated velocities for the centroid of the dye plume ranged from 0.80 to 3.02 feet per second within the study reach from Missouri River Headwaters to Townsend Bridge, near Townsend. The mean velocity of the dye plume for the entire study reach, excluding the subreach between the abandoned Milwaukee Railroad bridge at Lombard, Montana (Milwaukee Bridge) and Broadwater-Missouri Dam (Broadwater Dam), was 2.87 feet per second. The velocity of the centroid of the dye plume for the subreach between Milwaukee Bridge and Broadwater Dam (Toston Reservoir) was 0.80 feet per second. The residence time for Toston Reservoir was 8.2 hours during this study. Estimated longitudinal dispersion rates of the dye plume for this study ranged from 0.72 feet per second for the subreach from Milwaukee Bridge to Broadwater Dam to 2.26 feet per second for the subreach from the U.S. Route 287 Bypass Bridge over the Missouri River north of Toston, Montana to Yorks Islands. A relation was determined between travel time of the peak concentration and the time for the dye plume to pass a site (duration of the dye plume). This relation can be used to estimate when the decreasing concentration of a potential contaminant is reduced to 10 percent of its peak concentration for accidental (contaminant or chemical) spills into the upper Missouri River.

A Low-Energy-Gap Thienochrysenocarbazole Dye for Highly Efficient Mesoscopic Titania Solar Cells: Understanding the Excited State and Charge Carrier Dynamics.

PubMed

Wang, Junting; Xie, Xinrui; Weng, Guorong; Yuan, Yi; Zhang, Jing; Wang, Peng

2018-05-09

Maintaining both a high external quantum efficiency and a large open-circuit photovoltage of dye-sensitized solar cells (DSSCs) is a crucial challenge in the process of developing narrow-energy-gap dyes for the capture of infrared solar photons. Herein, we report two donor-acceptor organic dyes, C294 and C295, with a polycyclic heteroaromatic unit, 6,11-dihydrothieno[3',2':8,9]chryseno[10,11,12,1-bcdefg]carbazole (TCC), as the central module of the electron donor, and ethylbenzothiadiazole-benzioc acid as the electron acceptor. The interfacial charge recombination was successfully mitigated by introducing an additional branched aliphatic chain in C295. Furthermore, the O⋅⋅⋅S nonbonding interaction between the oxygen atom of the alkoxy group and the sulfur atom of the thiophene in C295 controlled the conformation of C295, resulting in a narrow energy-gap. Time-resolved spectroscopic measurements on C294 and the model dye C272 indicated that the elevation of the HOMO energy level decreased the kinetics and yield of hole injection owing to a reduction in the driving force and that the shortened excited-state lifetime caused by the narrowing of the energy gap was unfavorable for electron injection. By fine tuning the composition of the electrolyte, C294 and C295 eventually achieved high power conversion efficiencies of 11.5 % and 12.4 %, respectively, under full sunlight of air mass 1.5 global conditions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Local delivery of fluorescent dye for fiber-optics confocal microscopy of the living heart.

PubMed

Huang, Chao; Kaza, Aditya K; Hitchcock, Robert W; Sachse, Frank B

2014-01-01

Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5-9 lines, which is comparable to 4-8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery.

Tuning the Electron-Transport and Electron-Accepting Abilities of Dyes through Introduction of Different π-Conjugated Bridges and Acceptors for Dye-Sensitized Solar Cells.

PubMed

Li, Yuanzuo; Sun, Chaofan; Song, Peng; Ma, Fengcai; Yang, Yanhui

2017-02-17

A series of dyes, containing thiophene and thieno[3,2-b]thiophene as π-conjugated bridging units and six kinds of groups as electron acceptors, were designed for dye-sensitized solar cells (DSSCs). The ground- and excited-state properties of the designed dyes were investigated by using density functional theory (DFT) and time-dependent DFT, respectively. Moreover, the parameters affecting the short-circuit current density and open-circuit voltage were calculated to predict the photoelectrical performance of each dye. In addition, the charge difference density was presented through a three-dimensional (3D) real-space analysis method to investigate the electron-injection mechanism in the complexes. Our results show that the longer conjugated bridge would inhibit the intramolecular charge transfer, thereby affecting the photoelectrical properties of DSSCs. Similarly, owing to the lowest chemical hardness, largest electron-accepting ability, dipole moment (μnormal ) and the change in the energy of the TiO 2 conduction band (ΔECB ), the dye with a (E)-3-(4-(benzo[c][1,2,5]thiadiazol-4-yl)phenyl)-2-cyanoacrylic acid (TCA) acceptor group would exhibit the most significant photoelectrical properties among the designed dyes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of surfactant and budesonide on the pulmonary distribution of fluorescent dye in mice.

PubMed

Huang, Liang-Ti; Yeh, Tsu-Fu; Kuo, Yu-Lin; Chen, Pin-Chuan; Chen, Chung-Ming

2015-02-01

Surfactant is a useful vehicle for the intratracheal delivery of medicine to the distal lung. The aim of this study was to analyze the effect of intratracheal surfactant and budesonide instillation on the pulmonary distribution of fluorescent dye in mice. Male athymic nude mice were assigned randomly as controls, fluorescent dye, fluorescent dye + surfactant (50 mg/kg), fluorescent dye + budesonide (0.25 mg/kg), and fluorescent dye + surfactant + budesonide groups. A total volume of 60 μL fluorescent solutions was intratracheally injected and followed by 60 μL of air. We photographed and measured fluorescence in the lungs, from the back, 15 minutes after intratracheal administration using an IVIS Xenogen imaging instrument. The fluorescent dye (1,1'-dioctadecyltetramethyl indotricarbocyanine iodide) was most strongly detected near the trachea and weakly detected in the lungs in mice administered with fluorescent solutions. Almost no fluorescence was seen in the lung region of control mice. Intratracheal administration of surfactant or budesonide increased fluorescent intensity compared with control mice. Combined administration of surfactant and budesonide further increased fluorescent intensity compared with mice given surfactant or budesonide alone. Surfactant and budesonide enhance the pulmonary distribution of fluorescent dye in mice. Copyright © 2014. Published by Elsevier B.V.

Interfacial charge separation and photovoltaic efficiency in Fe(ii)-carbene sensitized solar cells.

PubMed

Pastore, Mariachiara; Duchanois, Thibaut; Liu, Li; Monari, Antonio; Assfeld, Xavier; Haacke, Stefan; Gros, Philippe C

2016-10-12

The first combined theoretical and photovoltaic characterization of both homoleptic and heteroleptic Fe(ii)-carbene sensitized photoanodes in working dye sensitized solar cells (DSSCs) has been performed. Three new heteroleptic Fe(ii)-NHC dye sensitizers have been synthesized, characterized and tested. Despite an improved interfacial charge separation in comparison to the homoleptic compounds, the heteroleptic complexes did not show boosted photovoltaic performances. The ab initio quantitative analysis of the interfacial electron and hole transfers and the measured photovoltaic data clearly evidenced fast recombination reactions for heteroleptics, even associated with un unfavorable directional electron flow, and hence slower injection rates, in the case of homoleptics. Notably, quantum mechanics calculations revealed that deprotonation of the not anchored carboxylic function in the homoleptic complex can effectively accelerate the electron injection rate and completely suppress the electron recombination to the oxidized dye. This result suggests that introduction of strong electron-donating substituents on the not-anchored carbene ligand in heteroleptic complexes, in such a way of mimicking the electronic effects of the carboxylate functionality, should yield markedly improved interfacial charge generation properties. The present results, providing for the first time a detailed understanding of the interfacial electron transfers and photovoltaic characterization in Fe(ii)-carbene sensitized solar cells, open the way to a rational molecular engineering of efficient iron-based dyes for photoelectrochemical applications.

Use of the routing procedure to study dye and gas transport in the West Fork Trinity River, Texas

USGS Publications Warehouse

Jobson, Harvey E.; Rathbun, R.E.

1984-01-01

Rhodamine-WT dye, ethylene, and propane were injected at three sites along a 21.6-kilometer reach of the West Fork Trinity River below Fort Worth, Texas. Complete dye concentration versus time curves and peak gas concentrations were measured at three cross sections below each injection. The peak dye concentrations were located and samples were collected at about three-hour intervals for as many as six additional cross sections. These data were analyzed to determine the longitudinal dispersion coefficients as well as the gas desorption coefficients using both standard techniques and a numerical routing procedure. The routing procedure, using a Lagrangian transport model to minimize numerical dispersion, provided better estimates of the dispersion coefficient than did the method of moments. At a steady flow of about 0.76 m2/s, the dispersion coefficient varied from about 0.7 m2/s in a reach contained within a single deep pool to about 2.0 m2/s in a reach containing riffles and small pools. The bulk desorption coefficients computed using the routing procedure and the standard peak method were essentially the same. The liquid film coefficient could also be obtained using the routing procedure. Both the bulk desorption coefficient and the liquid film coefficient were much smaller in the pooled reach than in the reaches containing riffles.

Modulation of π-spacer of carbazole-carbazole based organic dyes toward high efficient dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Chitpakdee, Chirawat; Jungsuttiwong, Siriporn; Sudyoadsuk, Taweesak; Promarak, Vinich; Kungwan, Nawee; Namuangruk, Supawadee

2017-03-01

The effects of type and position of π-linker in carbazole-carbazole based dyes on their performance in dye-sensitized solar cells (DSSCs) were investigated by DFT and TDDFT methods. The calculated electronic energy level, electron density composition, charge injection and charge recombination properties were compared with those of the high performance CCT3A dye synthesized recently. It is found that that mixing a benzothiadizole (B) unit with two thiophene (T) units in the π-spacer can greatly shift absorption wavelength to near infrared region and enhance the light harvesting efficiency (LHE) resulting in increasing of short-circuit current density (Jsc), whereas a thienothiophene unit does not affect those properties. However, a B should be not directly connected to the anchoring group of the dye because it brings electrolyte to the TiO2 surface which may increase charge recombination rate and consequently decrease open circuit voltage (Voc). This work shows how type and position of the π-linker affect the performance of DSSCs, and how to modulate those properties. We predicted that the designed dye derived from insertion of the B unit in between the two T units would have higher performance than CCT3A dye. The insight understanding from this study is useful for further design of higher performance dyes by molecular engineering.

THE LYMPHATIC VESSELS IN RADIODERMATITIS: A CLINICAL AND EXPERIMENTAL STUDY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, F.R.

1963-07-01

The response of human skin to x radiation (7500-r doses), particularly of dermal blood vessels, during radiotherapy was studied in 12 patients by injection of the lymphatic vessels of irradiated skin by a technlque modified after Hudack and McMaster. The appearance of skin lesions in the 12 patients with radiodermatitis was compared with those in 57 other subjects following intralymphatic injection of dye. In addition, skin specimens from three patients and seven controls were histologically examined by the dye-iron Prussian Blue technique. Abnormal lymphatic distribution was seen in 11 lesions and another showed borderline abnormality. Three types of lymphatic lesionmore » are described: abnormally superficial long collaterals and slight general dilatation of the superficial plexus; gross lymphedema and lymphangiectasia; and subtotal destruction of the lymphatic network, leaving only occasional collaterals near the edge of the lesion. Three possible mechanisms are suggested: long-term reduction in deep lymphatic drainage, possibly aggravated by destruction of a proportion of the mid-dermal communicating vessels, long-term increases in vascular permeability resulting in permanent lymphatic overload, possibly aggravated by increased blood flow through the telangiectatic, thin-walled vessels; and long-term or even moderately prolonged lymphatic lesion at the superficial or nud-dermal level disrupting the natural protein-removing process which occurs in other inflammatory states. Related investigations in mice showed that lymphatic vessels undergo a phase of increased permeability to dye-iron mixtures which may last up to six hr in the mouse ear following a localized dose of 2000 to 4000 rad. Thus, prolonged protein leakage from the lymphatics (as the result of locally increased permeability) may be an important factor in perpetuating postirradiation skin lymphedema and the accompanying dermal fibrosis. The results suggest that this dye injection technique may be of value in cases of dense scarring or ulceration to delimit the minimum area of skin which must be excised before grafting if proper healing is to be obtained. Some factors which might be responsible for the changes seen are tabulated, and an appendix on injection technlque and photography is included. (BBB)« less

Efficacy of using an air arthrogram for EUA and injection of the hip joint in adults.

PubMed

Shahid, Mohammad; Shyamsundar, Srinivasan; Bali, Navi; McBryde, Callum; O'Hara, John; Bache, Edward

2014-09-01

Hip arthrography usually requires the injection of iodine based dyes which can cause complications. We wanted to determine the accuracy of using air for hip arthrography. A prospective study was undertaken including all adults who had a hip arthrogram. We initially did an air arthrogram and subsequently injected iohexol to see if we were still in the joint. Forty injections were done. Mean age 32 years. There was a 100% success rate with obtaining a positive air arthrogram. Air arthrogram of the hip offers a safe, cost free and accurate alternative to iodine based arthrograms.

The carbocyanine dye DiD labels in vitro and in vivo neural stem cells of the subventricular zone as well as myelinated structures following in vivo injection in the lateral ventricle.

PubMed

Carradori, Dario; Barreau, Kristell; Eyer, Joël

2016-02-01

Carbocyanines are fluorescent lipophilic cationic dyes used since the early 1980s as neuronal tracers. Several applications of these compounds have been developed thanks to their low cell toxicity, lateral diffusion within the cellular membranes, and good photostability. 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine 4-chlorobenzenesulfonate (DiD) is an interesting component of this family because, in addition to the classic carbocyanine properties, it has a longer wavelength compared with its analogues. That makes DiD an excellent carbocyanine for labeling cells and tissues with significant intrinsic fluorescence. Drug encapsulation, drug delivery, and cellular transplantation are also fields using DiD-based systems where having detailed knowledge about its behavior as a single entity is important. Recently, promising studies concerned neural stem cells from the subventricular zone of the lateral ventricle in the brain (their natural niche) and their potential therapeutic use. Here, we show that DiD is able to label these stem cells in vitro and present basilar information concerning its pharmacokinetics, concentrations, and microscope protocols. Moreover, when DiD is injected in vivo in the cerebrospinal fluid present in the lateral ventricle of rat, it also labels stem cells as well as myelinated structures of the caudoputamen. This analysis provides a database to consult when planning experiments concerning DiD and neural stem cells from the subventricular zone. © 2015 Wiley Periodicals, Inc.

Chemical modification of normal tissue damage induced by photodynamic therapy.

PubMed Central

Sigdestad, C. P.; Fingar, V. H.; Wieman, T. J.; Lindberg, R. D.

1996-01-01

One of the limitations of successful use of photodynamic therapy (PDT) employing porphyrins is the acute and long-term cutaneous photosensitivity. This paper describes results of experiments designed to test the effects of two radiation protective agents (WR-2721, 500 mg kg-1 or WR-3689, 700 mg kg-1) on murine skin damage induced by PDT. C3H mice were shaved and depilated three days prior to injection with the photosensitiser, Photofrin (5 or 10 mg kg-1). Twenty-four hours later, the mice were injected intraperitoneally with a protector 30 min prior to Argon dye laser (630 nm) exposure. The skin response was followed for two weeks post irradiation using an arbitrary response scale. A light dose response as well as a drug dose response was obtained. The results indicate that both protectors reduced the skin response to PDT, however WR-2721 was demonstrated to be the most effective. The effect of the protectors on vascular stasis after PDT was determined using a fluorescein dye exclusion assay. In mice treated with Photofrin (5 mg kg-1), and 630 nm light (180 J cm-2) pretreatment with either WR-2721 or WR-3689 resulted in significant protection of the vascular effects of PDT. These studies document the ability of the phosphorothioate class of radiation protective agents to reduce the effects of light on photosensitized skin. They do so in a drug dose-dependent fashion with maximum protection at the highest drug doses. PMID:8763855

Sentinel lymph node detection in early stage cervical cancer: a prospective study comparing preoperative lymphoscintigraphy, intraoperative gamma probe, and blue dye.

PubMed

Kara, P Pelin; Ayhan, Ali; Caner, Biray; Gültekin, Murat; Ugur, Omer; Bozkurt, M Fani; Usubutun, Alp

2008-07-01

The objective of this prospective study was to determine the feasibility of sentinel lymph node (SLN) detection in patients with cervical cancer using lymphoscintigraphy (LS), gamma probe, and blue dye. A total of 32 patients with early stage cervical cancer (FIGO IA2-IIA) who were treated with total abdominal hysterectomy and bilateral pelvic and paraortic lymphadenectomy underwent SLN biopsy. LS was performed on all the patients following the injection of 74 MBq technetium-99m-nanocolloid pericervically. The first appearing persistent focal accumulation on either dynamic or static images of LS was considered to be an SLN. Blue dye was injected just prior to surgical incision in 16 patients (50%) at the same locations as the radioactive isotope injection. During the operation, blue-stained node(s) were excised as SLNs. For gamma probe, a lymph node was accepted as an SLN, if its ex vivo radioactive counts were at least 10-fold above background radioactivity. SLNs, which were negative by routine hematoxylin and eosin (H&E) examination, were histopathologically reevaluated for the presence of micrometastases by step sectioning and immunohistochemical staining with pancytokeratin. At least one SLN was identified for each patient by gamma probe. Intraoperative gamma probe was the most sensitive method with a technical success rate of SLN detection of 100% (32/32), followed by LS 87.5% (28/32) and blue dye 68.8% (11/16), respectively. The average number of SLNs per patient detected by gamma probe was 2.09 (range 1-5). The localizations of the SLNs were external iliac 47.8%, obturatory 32.8%, common iliac 9%, paraaortic 4.4%, and paracervical 6%. Micrometastases, not detected by routine H&E were found by immunohistochemistry in one patient. On the basis of the histopathological analysis, the negative predictive value for predicting metastases was 100%, and there were no false-negative results. Preoperative LS with radiocolloids, intraoperative lymphatic mapping with blue dye and gamma probe are all feasible methods comparable with each other for SLN detection in early stage cervical cancer patients, but gamma probe is the most useful method in terms of technical success.

Evaluation of the acute and chronic safety of the biosense injection catheter system in porcine hearts.

PubMed

Kornowski, R; Fuchs, S; Tio, F O; Pierre, A; Epstein, S E; Leon, M B

1999-12-01

Direct myocardial injection of therapeutic agents has been explored as a new method for myocardial revascularization. The integration of a 3D electromechanical mapping catheter with a retractable injection needle should allow for intramyocardial injection to identified sites, obviating the need for open heart surgery. This study assessed the procedural safety and performance characteristics of a novel guided catheter-based transendocardial injection system. The electromagnetic guidance system was coupled with a retrievable 27G needle for left ventricular endocardial injection. Using this system, we injected, transendocardially, methylene-blue (MB) dye tracer at a volume of 0.1 or 0.2 ml per injection in eight normal pigs. Animals were sacrificed acutely, at 1, 3, and 7 days (two animal in each time). Three animals served as controls. The injections were followed by coronary angiography and echocardiogram to assess possible ventricular or coronary perforation and wall motion abnormalities. CK-MB levels were measured up to 24 hr following the procedure. The animals were sacrificed at the assigned time for gross and histopathology evaluation. A total of 101 injections were made in all regions of the heart except the apex and the mitral valve. No animal died as a result of the mapping or injection procedures. Vital signs did not change relative to baseline after the mapping and injection procedures. CK-MB values did not increase over time and there was no evidence of sustained arrhythmia or hemodynamic compromise. There was no evidence of left ventricular or coronary perforation, global or regional wall motion abnormalities, or hemopericardium. On histologic evaluation, the estimated volume of tissue staining was greater than the volume of the injected MB dye due to dispersion of the injectate in the interstitial and intracellular fluid compartments. It is concluded that using this magnetic guidance catheter-based navigational system, it is feasible and safe to perform the transendocardial injection procedure. Thus, if it is determined that direct intramyocardial injection of drugs is a valid therapeutic strategy, this approach offers a clear advantage over surgically based transepicardial injection procedures. Cathet. Cardiovasc. Intervent. 48:447-453, 1999. Copyright 1999 Wiley-Liss, Inc.

Heart and vascular services

MedlinePlus

... using x-rays and injected contrast dye to evaluate blood vessels) Angioplasty (using a small balloon to ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

Performance and mechanism of simultaneous removal of Cd(II) and Congo red from aqueous solution by hierarchical vaterite spherulites

NASA Astrophysics Data System (ADS)

Chen, Yuan-Yuan; Yu, Sheng-Hui; Jiang, Hao-Fan; Yao, Qi-Zhi; Fu, Sheng-Quan; Zhou, Gen-Tao

2018-06-01

Hierarchical vaterite spherulites, synthesized by a simple injection-precipitation method at room temperature, were applied for the simultaneous removal of heavy metal Cd(II) and dye Congo red (CR) from aqueous solution. Batch experiments reveal that the maximum removal capacities of as-prepared vaterite spherulites to Cd(II) and CR are 984.5 and 89.0 mg/g, respectively, showing excellent removal performance for Cd(II) and CR. Furthermore, in the binary Cd(II)-CR system, the removal capacity of vaterite to Cd(II) is significantly enhanced at lower CR concentration (<100 mg/L), but inhibited at higher CR concentration (>100 mg/L). In contrast, the concurrent Cd(II) shows negligible effect on the CR removal. The simultaneous removal mechanism was investigated by FESEM, EDX, XRD, FT-IR and XPS techniques. The simultaneous removal of Cd(II) and CR in the binary system is shown to be a multistep process, involving the preferential adsorption of dye CR, stabilization of CR to vaterite, coordination of the adsorbed CR molecules with Cd(II), and transformation of vaterite into otavite. Given the facile and green synthesis procedure, and effective removal of Cd(II) and CR in the binary system, the obtained vaterite spherulites have considerable practical interest in integrative treatment of wastewater contaminated by heavy metals and dyes.

The Contribution of Prohibitin 1 to Prostate Cancer Chemoresistance

DTIC Science & Technology

2015-10-01

ceramide-PEG5K in normal BALB/c mice after i.v. injection. The siRNA was labeled with near infrared (NIR) dye DY647. (B) Ex vivo fluorescence image of...ceramide-PEG5K (Right) siRNA NPs at 18 h. The siRNA was labeled with dye DY547. (Scale bar, 10 μm.) Zhu et al. PNAS | June 23, 2015 | vol. 112 | no...Woodrow KA, et al. (2009) Intravaginal gene silencing using biodegradable polymer nanoparticles densely loaded with small-interfering RNA. Nat Mater

An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

ERIC Educational Resources Information Center

Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

2012-01-01

An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

Subnanometer Ga2O3 tunnelling layer by atomic layer deposition to achieve 1.1 V open-circuit potential in dye-sensitized solar cells.

PubMed

Chandiran, Aravind Kumar; Tetreault, Nicolas; Humphry-Baker, Robin; Kessler, Florian; Baranoff, Etienne; Yi, Chenyi; Nazeeruddin, Mohammad Khaja; Grätzel, Michael

2012-08-08

Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new DSC record open-circuit potential of 1.1 V with state-of-the-art organic D-π-A sensitizer and cobalt redox mediator. After ALD of only a few angstroms of Ga(2)O(3), the electron back reaction is reduced by more than an order of magnitude, while charge collection efficiency and fill factor are increased by 30% and 15%, respectively. The photogenerated exciton separation processes of electron injection into the TiO(2) conduction band and the hole injection into the electrolyte are characterized in detail.

Multi-modal in vivo imaging of brain blood oxygenation, blood flow and neural calcium dynamics during acute seizures

NASA Astrophysics Data System (ADS)

Ringuette, Dene; Jeffrey, Melanie A.; Carlen, Peter L.; Levi, Ofer

2016-03-01

Dysfunction of the vascular endothelium has been implicated in the development of epilepsy. To better understand the relation between vascular function and seizure and provide a foundation for interpreting results from functional imaging in chronic disease models, we investigate the relationship between intracellular calcium dynamics and local cerebral blood flow and blood oxygen saturation during acute seizure-like events and pharmacological seizure rescue. To probe the relation between the aforementioned physiological markers in an acute model of epilepsy in rats, we integrated three different optical modalities together with electrophysiological recordings: Laser speckle contrast imaging (LSCI) was used to study changes in flow speeds, Intrinsic optical signal imaging (IOSI) was used to monitor changes in oxygenated, de-oxygenated, and total hemoglobin concentration, and Calcium-sensitive dye imaging was used to monitor intracellular calcium dynamics. We designed a dedicated cortical flow chamber to remove superficial blood and dye resulting from the injection procedure, which reduced spurious artifacts. The near infrared light used for IOSI and LSCI was delivered via a light pipe integrated with the flow chamber to minimize the effect of fluid surface movement on illumination stability. Calcium-sensitive dye was injected via a glass electrode used for recording the local field potential. Our system allowed us to observe and correlate increases in intracellular calcium, blood flow and blood volume during seizure-like events and provide a quantitative analysis of neurovascular coupling changes associated with seizure rescue via injection of an anti-convulsive agent.

Near Field Enhanced Photocurrent Generation in P-type Dye-Sensitized Solar Cells

PubMed Central

Xu, Xiaobao; Cui, Jin; Han, Junbo; Zhang, Junpei; Zhang, Yibo; Luan, Lin; Alemu, Getachew; Wang, Zhong; Shen, Yan; Xiong, Dehua; Chen, Wei; Wei, Zhanhua; Yang, Shihe; Hu, Bin; Cheng, Yibing; Wang, Mingkui

2014-01-01

Over the past few decades, the field of p-type dye-sensitized solar cell (p-DSSC) devices has undergone tremendous advances, in which Cu-based delafossite nanocrystal is of prime interest. This paper presents an augment of about 87% improvement in photocurrent observed in a particular configuration of organic dye P1 sensitized CuCrO2 delafossite nanocrystal electrode coupled with organic redox shuttle, 1-methy-1H- tetrazole-5-thiolate and its disulfide dimer when Au nanoparticles (NPs, with diameter of about 20 nm) is added into the photocathode, achieving a power convert efficiency of 0.31% (measured under standard AM 1.5 G test conditions). Detailed investigation shows that the local electrical-magnetic field effect, induced by Au NPs among the mesoporous CuCrO2 film, can improve the charge injection efficiency at dye/semiconductor interface, which is responsible for the bulk of the gain in photocurrent. PMID:24492539

Dye-Sensitized Hydrobromic Acid Splitting for Hydrogen Solar Fuel Production.

PubMed

Brady, Matthew D; Sampaio, Renato N; Wang, Degao; Meyer, Thomas J; Meyer, Gerald J

2017-11-08

Hydrobromic acid (HBr) has significant potential as an inexpensive feedstock for hydrogen gas (H 2 ) solar fuel production through HBr splitting. Mesoporous thin films of anatase TiO 2 or SnO 2 /TiO 2 core-shell nanoparticles were sensitized to visible light with a new Ru II polypyridyl complex that served as a photocatalyst for bromide oxidation. These thin films were tested as photoelectrodes in dye-sensitized photoelectrosynthesis cells. In 1 N HBr (aq), the photocatalyst undergoes excited-state electron injection and light-driven Br - oxidation. The injected electrons induce proton reduction at a Pt electrode. Under 100 mW cm -2 white-light illumination, sustained photocurrents of 1.5 mA cm -2 were measured under an applied bias. Faradaic efficiencies of 71 ± 5% for Br - oxidation and 94 ± 2% for H 2 production were measured. A 12 μmol h -1 sustained rate of H 2 production was maintained during illumination. The results demonstrate a molecular approach to HBr splitting with a visible light absorbing complex capable of aqueous Br - oxidation and excited-state electron injection.

Study on pigment dyeing opportunities of polyester and cotton-mix fiber

NASA Astrophysics Data System (ADS)

Nabieva, I. A.; Shamukimova, M. B.; Artikboeva, R. M.

2017-11-01

The process of coloring the dyeing pigments in polyether and cotton fibers for different fabrics, which are inclined to dye, have been studied in this article. Based on the experiences on pigments dyeing, it was suggested to study the materials with the dyeing pigment substances with the purpose of improving the technology of color forming.

Movement and dispersion of soluble pollutants in the Northeast Cape Fear Estuary, North Carolina

USGS Publications Warehouse

Hubbard, E.F.; Stamper, William G.

1972-01-01

This report presents the results of a fluorescent-dye-tracing study to determine the concentrations of a pollutant that would be present in the Northeast Cape Fear Estuary at various rates of continuous waste injection and freshwater inflow. Rhodamine WT dye was introduced into the estuary at a constant rate over a 24.8-hour period (two tidal cycles) at a point 6.4 miles upstream from the mouth in Wilmington, N.C., and concentrations were monitored at several selected sections in the tide-affected part of the river for 17 days. The range between high and low tide in this reach of the estuary averages at-rut 3.5 feet, and there is usually strong flow in both directions. Results of the dye study indicate that if a pollutant were injected at a rate of 100 pounds per day under the conditions of relatively low inflow existing' at the time, concentrations would ultimately build up to 20 micrograms of dye per liter of water 1,000 feet downstream. The flushing time during the study is estimated to be 17 days. These results are extrapolated to include periods of lower or higher inflow. For example, at average intervals of 10 years, it is estimated that inflow is so low that 100 days are required for a pollutant to travel the 6.4 miles from the point of waste release to the mouth of the river. Under these conditions it is expected that 1,000 feet downstream from the point of waste discharge, daily maximum concentrations will average about 130 micrograms per liter for each 100 pounds of pollutant injected per day. Results of a continuous discharge measurement of flow made by current meter during a complete tidal cycle are presented as a part of this report. Data from this measurement and other evidence indicate that net upstream flow in the estuary is possible over a period of several days.

Dynamics of Back Electron Transfer in Dye-Sensitized Solar Cells Featuring 4-tert-Butyl-Pyridine and Atomic-Layer-Deposited Alumina as Surface Modifiers.

PubMed

Katz, Michael J; Vermeer, Michael J DeVries; Farha, Omar K; Pellin, Michael J; Hupp, Joseph T

2015-06-18

A series of dye-sensitized solar cells (DSCs) was constructed with TiO2 nanoparticles and N719 dye. The standard I3(-)/I(-) redox shuttle and the Co(1,10-phenanthroline)3(3+/2+) shuttle were employed. DSCs were modified with atomic-layered-deposited (ALD) coatings of Al2O3 and/or with the surface-adsorbing additive 4-tert-butyl-pyridine. Current-voltage data were collected to ascertain the influence of each modification upon the back electron transfer (ET) dynamics of the DSCs. The primary effect of the additives alone or in tandem is to increase the open-circuit voltage. A second is to alter the short-circuit current density, JSC. With dependence on the specifics of the system examined, any of a myriad of dynamics-related effects were observed to come into play, in both favorable (efficiency boosting) and unfavorable (efficiency damaging) ways. These effects include modulation of (a) charge-injection yields, (b) rates of interception of injected electrons by redox shuttles, and (c) rates of recombination of injected electrons with holes on surface-bound dyes. In turn, these influence charge-collection lengths, charge-collection yields, and onset potentials for undesired dark current. The microscopic origins of the effects appear to be related mainly to changes in driving force and/or electronic coupling for underlying component redox reactions. Perhaps surprisingly, only a minor role for modifier-induced shifts in conduction-band-edge energy was found. The combination of DSC-efficiency-relevant effects engendered by the modifiers was found to vary substantially as a function of the chemical identity of the redox shuttle employed. While types of modifiers are effective, a challenge going forward will be to construct systems in ways in which the benefits of organic and inorganic modifiers can be exploited in fully additive, or even synergistic, fashion.

Tidal-flow, circulation, and flushing characteristics of Kings Bay, Citrus County, Florida

USGS Publications Warehouse

Hammett, K.M.; Goodwin, C.R.; Sanders, G.L.

1996-01-01

Kings Bay is an estuary on the gulf coast of peninsular Florida with a surface area of less than one square mile. It is a unique estuarine system with no significant inflowing rivers or streams. As much as 99 percent of the freshwater entering the bay originates from multiple spring vents at the bottom of the estuary. The circulation and flushing characteristics of Kings Bay were evaluated by applying SIMSYS2D, a two-dimensional numerical model. Field data were used to calibrate and verify the model. Lagrangian particle simulations were used to determine the circulation characteristics for three hydrologic conditions: low inflow, typical inflow, and low inflow with reduced friction from aquatic vegetation. Spring discharge transported the particles from Kings Bay through Crystal River and out of the model domain. Tidal effects added an oscillatory component to the particle paths. The mean particle residence time was 59 hours for low inflow with reduced friction; therefore, particle residence time is affected more by spring discharge than by bottom friction. Circulation patterns were virtually identical for the three simulated hydroloigc conditions. Simulated particles introduced in the southern part of Kings Bay traveled along the eastern side of Buzzard Island before entering Crystal River and existing the model domain. The flushing characteristics of Kings Bay for the three hydrodynamic conditions were determined by simulating the injection of conservative dye constituents. The average concentration of dye initially injected in Kings Bay decreased asymptotically because of spring discharge, and the tide caused some oscillation in the average dye concentration. Ninety-five percent of the injected dye exited Kings Bay and Crystal River with 94 hours for low inflow, 71 hours for typical inflow, and 94 hours for low inflow with reduced bottom friction. Simulation results indicate that all of the open waters of Kings Bay are flushed by the spring discharge. Reduced bottom friction has little effect on flushing.

Interaction of phenazinium dyes with double-stranded poly(A): Spectroscopy and isothermal titration calorimetry studies

NASA Astrophysics Data System (ADS)

Khan, Asma Yasmeen; Saha, Baishakhi; Kumar, Gopinatha Suresh

2014-10-01

A comprehensive study on the binding of phenazinium dyes viz. janus green B, indoine blue, safranine O and phenosafranine with double stranded poly(A) using various spectroscopic and calorimetric techniques is presented. A higher binding of janus green B and indoine blue over safranine O and phenosafranine to poly(A) was observed from all experiments. Intercalative mode of binding of the dyes was inferred from fluorescence polarization anisotropy, iodide quenching and viscosity experiments. Circular dichroism study revealed significant perturbation of the secondary structure of poly(A) on binding of these dyes. Results from isothermal titration calorimetry experiments suggested that the binding was predominantly entropy driven with a minor contribution of enthalpy to the standard molar Gibbs energy. The results presented here may open new opportunities in the application of these dyes as RNA targeted therapeutic agents.

Monitoring changes in the intracellular calcium concentration and synaptic efficacy in the mollusc Aplysia.

PubMed

Ludwar, Bjoern Ch; Evans, Colin G; Cropper, Elizabeth C

2012-07-15

It has been suggested that changes in intracellular calcium mediate the induction of a number of important forms of synaptic plasticity (e.g., homosynaptic facilitation). These hypotheses can be tested by simultaneously monitoring changes in intracellular calcium and alterations in synaptic efficacy. We demonstrate how this can be accomplished by combining calcium imaging with intracellular recording techniques. Our experiments are conducted in a buccal ganglion of the mollusc Aplysia californica. This preparation has a number of experimentally advantageous features: Ganglia can be easily removed from Aplysia and experiments use adult neurons that make normal synaptic connections and have a normal ion channel distribution. Due to the low metabolic rate of the animal and the relatively low temperatures (14-16 °C) that are natural for Aplysia, preparations are stable for long periods of time. To detect changes in intracellular free calcium we will use the cell impermeant version of Calcium Orange which is easily 'loaded' into a neuron via iontophoresis. When this long wavelength fluorescent dye binds to calcium, fluorescence intensity increases. Calcium Orange has fast kinetic properties and, unlike ratiometric dyes (e.g., Fura 2), requires no filter wheel for imaging. It is fairly photo stable and less phototoxic than other dyes (e.g., fluo-3). Like all non-ratiometric dyes, Calcium Orange indicates relative changes in calcium concentration. But, because it is not possible to account for changes in dye concentration due to loading and diffusion, it can not be calibrated to provide absolute calcium concentrations. An upright, fixed stage, compound microscope was used to image neurons with a CCD camera capable of recording around 30 frames per second. In Aplysia this temporal resolution is more than adequate to detect even a single spike induced alteration in the intracellular calcium concentration. Sharp electrodes are simultaneously used to induce and record synaptic transmission in identified pre- and postsynaptic neurons. At the conclusion of each trial, a custom script combines electrophysiology and imaging data. To ensure proper synchronization we use a light pulse from a LED mounted in the camera port of the microscope. Manipulation of presynaptic calcium levels (e.g. via intracellular EGTA injection) allows us to test specific hypotheses, concerning the role of intracellular calcium in mediating various forms of plasticity.

Travel Times, Streamflow Velocities, and Dispersion Rates in the Yellowstone River, Montana

USGS Publications Warehouse

McCarthy, Peter M.

2009-01-01

The Yellowstone River is a vital natural resource to the residents of southeastern Montana and is a primary source of water for irrigation and recreation and the primary source of municipal water for several cities. The Yellowstone River valley is the primary east-west transportation corridor through southern Montana. This complex of infrastructure makes the Yellowstone River especially vulnerable to accidental spills from various sources such as tanker cars and trucks. In 2008, the U.S. Geological Survey (USGS), in cooperation with the Montana Department of Environmental Quality, initiated a dye-tracer study to determine instream travel times, streamflow velocities, and dispersion rates for the Yellowstone River from Lockwood to Glendive, Montana. The purpose of this report is to describe the results of this study and summarize data collected at each of the measurement sites between Lockwood and Glendive. This report also compares the results of this study to estimated travel times from a transport model developed by the USGS for a previous study. For this study, Rhodamine WT dye was injected at four locations in late September and early October 2008 during reasonably steady streamflow conditions. Streamflows ranged from 3,490 to 3,770 cubic feet per second upstream from the confluence of the Bighorn River and ranged from 6,520 to 7,570 cubic feet per second downstream from the confluence of the Bighorn River. Mean velocities were calculated for each subreach between measurement sites for the leading edge, peak concentration, centroid, and trailing edge at 10 percent of the peak concentration. Calculated velocities for the centroid of the dye plume for subreaches that were completely laterally mixed ranged from 1.83 to 3.18 ft/s within the study reach from Lockwood Bridge to Glendive Bridge. The mean of the completely mixed centroid velocity for the entire study reach, excluding the subreach between Forsyth Bridge and Cartersville Dam, was 2.80 ft/s. Longitudinal dispersion rates of the dye plume for this study ranged from 0.06 ft/s for the subreach upstream from Forsyth Bridge to 2.25 ft/s for the subreach upstream from Calyspo Bridge for subreaches where the dye was completely laterally mixed. A relation was determined between travel time of the peak concentration and time for the dye plume to pass a site (duration). This relation can be used to estimate when the receding concentration of a potential contaminant reaches 10 percent of its peak concentration for accidental spills into the Yellowstone River. Data from this dye-tracer study were used to evaluate velocity and concentration estimates from a transport model developed as part of an earlier USGS study. Comparison of the estimated and calculated velocities for the study reach indicate that the transport model estimates the velocities of the Yellowstone River between Huntley Bridge and Glendive Bridge with reasonable accuracy. Velocities of the peak concentration of the dye plume calculated for this study averaged 10 percent faster than the most probable velocities and averaged 12 percent slower than the maximum probable velocities estimated from the transport model. Peak Rhodamine WT dye concentrations were consistently lower than the transport model estimates except for the most upstream subreach of each dye injection. The most upstream subreach of each dye injection is expected to have a higher concentration because of incomplete lateral mixing. Lower measured peak concentrations for all other sites were expected because Rhodamine WT dye deteriorates when exposed to sunlight and will sorb onto the streambanks and stream bottom. Velocity-streamflow relations developed by using routine streamflow measurements at USGS gaging stations and the transport model can be used to estimate mean streamflow velocities throughout a range of streamflows. The variation in these velocity-streamflow relations emphasizes the uncertainty in estimating the mean streamflow veloc

Ultrafast electron and energy transfer in dye-sensitized iron oxide and oxyhydroxide nanoparticles.

PubMed

Gilbert, Benjamin; Katz, Jordan E; Huse, Nils; Zhang, Xiaoyi; Frandsen, Cathrine; Falcone, Roger W; Waychunas, Glenn A

2013-10-28

An emerging area in chemical science is the study of solid-phase redox reactions using ultrafast time-resolved spectroscopy. We have used molecules of the photoactive dye 2',7'-dichlorofluorescein (DCF) anchored to the surface of iron(III) oxide nanoparticles to create iron(II) surface atoms via photo-initiated interfacial electron transfer. This approach enables time-resolved study of the fate and mobility of electrons within the solid phase. However, complete analysis of the ultrafast processes following dye photoexcitation of the sensitized iron(III) oxide nanoparticles has not been reported. We addressed this topic by performing femtosecond transient absorption (TA) measurements of aqueous suspensions of uncoated and DCF-sensitized iron oxide and oxyhydroxide nanoparticles, and an aqueous iron(III)-dye complex. Following light absorption, excited state relaxation times of the dye of 115-310 fs were found for all samples. Comparison between TA dynamics on uncoated and dye-sensitized hematite nanoparticles revealed the dye de-excitation pathway to consist of a competition between electron and energy transfer to the nanoparticles. We analyzed the TA data for hematite nanoparticles using a four-state model of the dye-sensitized system, finding electron and energy transfer to occur on the same ultrafast timescale. The interfacial electron transfer rates for iron oxides are very close to those previously reported for DCF-sensitized titanium dioxide (for which dye-oxide energy transfer is energetically forbidden) even though the acceptor states are different. Comparison of the alignment of the excited states of the dye and the unoccupied states of these oxides showed that the dye injects into acceptor states of different symmetry (Ti t2gvs. Fe eg).

Meningitis and Encephalitis

MedlinePlus

... as a CT scan, combines x-rays and computer technology to produce rapid, clear, two-dimensional images of organs, bones, and tissues. Occasionally a contrast dye is injected into the ... imaging (MRI) uses computer-generated radio waves and a strong magnet to ...

An Assessment of Aquifer/Well Flow Dynamics: Identification of Parameters Key to Passive Sampling and Application of Downhole Sensor Technologies

DTIC Science & Technology

2014-12-01

Simulated Solute Transport in a Numerical Replication of Britt’s 2005 Experiment Figure 44 In-Well Flow Inhibitor Figure 45 Results of a Preliminary Dye ...Tracer Experiment Conducted at INL Figure 46 Results Horizontally-Oriented Dye Tracer Experiment Conducted at INL ER-1704 Final Report 2014 vii...possible sources of well convection and mixing. Specifically, the modeling explored: • 2D and 3D physical tank models. Dye tracer testing was conducted

Application of Tracer-Injection Techniques to Demonstrate Surface-Water and Ground-Water Interactions Between an Alpine Stream and the North Star Mine, Upper Animas River Watershed, Southwestern Colorado

USGS Publications Warehouse

Wright, Winfield G.; Moore, Bryan

2003-01-01

Tracer-injection studies were done in Belcher Gulch in the upper Animas River watershed, southwestern Colorado, to determine whether the alpine stream infiltrates into underground mine workings of the North Star Mine and other nearby mines in the area. The tracer-injection studies were designed to determine if and where along Belcher Gulch the stream infiltrates into the mine. Four separate tracer-injec-tion tests were done using lithium bromide (LiBr), optical brightener dye, and sodium chloride (NaCl) as tracer solu-tions. Two of the tracers (LiBr and dye) were injected con-tinuously for 24 hours, one of the NaCl tracers was injected continuously for 12 hours, and one of the NaCl tracers was injected over a period of 1 hour. Concentration increases of tracer constituents were detected in water discharging from the North Star Mine, substantiating a surface-water and ground-water connection between Belcher Gulch and the North Star Mine. Different timing and magnitude of tracer breakthroughs indicated multiple flow paths with different residence times from the stream to the mine. The Pittsburgh and Sultan Mines were thought to physically connect to the North Star Mine, but tracer breakthroughs were inconclusive in water from these mines. From the tracer-injection tests and synoptic measure-ments of streamflow discharge, a conceptual model was devel-oped for surface-water and ground-water interactions between Belcher Gulch and the North Star Mine. This information, combined with previous surface geophysical surveys indicat-ing the presence of subsurface voids, may assist with decision-making process for preventing infiltration and for the remedia-tion of mine drainage from these mines.

Development of thermosensitive chitosan/glicerophospate injectable in situ gelling solutions for potential application in intraoperative fluorescence imaging and local therapy of hepatocellular carcinoma: a preliminary study.

PubMed

Salis, Andrea; Rassu, Giovanna; Budai-Szűcs, Maria; Benzoni, Ilaria; Csányi, Erzsébet; Berkó, Szilvia; Maestri, Marcello; Dionigi, Paolo; Porcu, Elena P; Gavini, Elisabetta; Giunchedi, Paolo

2015-01-01

Thermosensitive chitosan/glycerophosphate (C/GP) solutions exhibiting sol-gel transition around body temperature were prepared to develop a class of injectable hydrogel platforms for the imaging and loco-regional treatment of hepatocellular carcinoma (HCC). Indocyanine green (ICG) was loaded in the thermosensitive solutions in order to assess their potential for the detection of tumor nodules by fluorescence. The gel formation of these formulations as well as their gelling time, injectability, compactness and resistance of gel structure, gelling temperature, storage conditions, biodegradability, and in vitro dye release behavior were investigated. Ex vivo studies were carried out for preliminary evaluation using an isolated bovine liver. Gel strengths and gelation rates increased with the cross-link density between C and GP. These behaviors are more evident for C/GP solutions, which displayed a gel-like precipitation at 4°C. Furthermore, formulations with the lowest cross-link density between C and GP exhibited the best injectability due to a lower resistance to flow. The loading of the dye did not influence the gelation rate. ICG was not released from the hydrogels because of a strong electrostatic interaction between C and ICG. Ex vivo preliminary studies revealed that these injectable formulations remain in correspondence of the injected site. The developed ICG-loaded hydrogels have the potential for intraoperative fluorescence imaging and local therapy of HCC as embolic agents. They form in situ compact gels and have a good potential for filling vessels and/or body cavities.

A multi-directional tracer test in the fractured Chalk aquifer of E. Yorkshire, UK.

PubMed

Hartmann, S; Odling, N E; West, L J

2007-12-07

A multi-borehole radial tracer test has been conducted in the confined Chalk aquifer of E. Yorkshire, UK. Three different tracer dyes were injected into three injection boreholes and a central borehole, 25 m from the injection boreholes, was pumped at 330 m(3)/d for 8 days. The breakthrough curves show that initial breakthrough and peak times were fairly similar for all dyes but that recoveries varied markedly from 9 to 57%. The breakthrough curves show a steep rise to a peak and long tail, typical of dual porosity aquifers. The breakthrough curves were simulated using a 1D dual porosity model. Model input parameters were constrained to acceptable ranges determined from estimations of matrix porosity and diffusion coefficient, fracture spacing, initial breakthrough times and bulk transmissivity of the aquifer. The model gave equivalent hydraulic apertures for fractures in the range 363-384 microm, dispersivities of 1 to 5 m and matrix block sizes of 6 to 9 cm. Modelling suggests that matrix block size is the primary controlling parameter for solute transport in the aquifer, particularly for recovery. The observed breakthrough curves suggest results from single injection-borehole tracer tests in the Chalk may give initial breakthrough and peak times reasonably representative of the aquifer but that recovery is highly variable and sensitive to injection and abstraction borehole location. Consideration of aquifer heterogeneity suggests that high recoveries may be indicative of a high flow pathway adjacent, but not necessarily connected, to the injection and abstraction boreholes whereas low recoveries may indicate more distributed flow through many fractures of similar aperture.

Design and Construction of Simple, Nitrogen-Laser-Pumped, Tunable Dye Lasers

ERIC Educational Resources Information Center

Hilborn, Robert C.

1978-01-01

The basic physical principles of dye lasers are discussed and used to analyze the design and operation of tunable dye lasers pumped by pulsed nitrogen lasers. Details of the design and construction of these dye lasers are presented. Some simple demonstration experiments are described. (BB)

Transport modalities of photodynamic agents for tumors

NASA Astrophysics Data System (ADS)

Reddi, Elena

1994-03-01

Systemically injected porphyrins and other tetrapyrrolic compounds associate with serum proteins. Highly hydrophobic photosensitizers are mainly associated with lipoproteins and are deposited in intracellular loci of the neoplastic tissue. Hydrophilic photosensitizers are preferentially bound by serum albumin that releases the dye in the vascular stroma of the tumor. As a consequence the type of photosensitizer carrier determines different mechanisms of PDT-induced tumor necrosis. Low-density lipoproteins (LDL) may increase the selectivity of tumor targeting by releasing the bound dye to the neoplastic cells by a receptor-mediated endocytotic mechanism.

Tumors induce coordinate growth of artery, vein, and lymphatic vessel triads.

PubMed

Ruddell, Alanna; Croft, Alexandra; Kelly-Spratt, Karen; Furuya, Momoko; Kemp, Christopher J

2014-05-21

Tumors drive blood vessel growth to obtain oxygen and nutrients to support tumor expansion, and they also can induce lymphatic vessel growth to facilitate fluid drainage and metastasis. These processes have generally been studied separately, so that it is not known how peritumoral blood and lymphatic vessels grow relative to each other. The murine B16-F10 melanoma and chemically-induced squamous cell carcinoma models were employed to analyze large red-colored vessels growing between flank tumors and draining lymph nodes. Immunostaining and microscopy in combination with dye injection studies were used to characterize these vessels. Each peritumoral red-colored vessel was found to consist of a triad of collecting lymphatic vessel, vein, and artery, that were all enlarged. Peritumoral veins and arteries were both functional, as detected by intravenous dye injection. The enlarged lymphatic vessels were functional in most mice by subcutaneous dye injection assay, however tumor growth sometimes blocked lymph drainage to regional lymph nodes. Large red-colored vessels also grew between benign papillomas or invasive squamous cell carcinomas and regional lymph nodes in chemical carcinogen-treated mice. Immunostaining of the red-colored vessels again identified the clustered growth of enlarged collecting lymphatics, veins, and arteries in the vicinity of these spontaneously arising tumors. Implanted and spontaneously arising tumors induce coordinate growth of blood and lymphatic vessel triads. Many of these vessel triads are enlarged over several cm distance between the tumor and regional lymph nodes. Lymphatic drainage was sometimes blocked in mice before lymph node metastasis was detected, suggesting that an unknown mechanism alters lymph drainage patterns before tumors reach draining lymph nodes.

A line source tracer test - a better method for assessing high groundwater velocity

NASA Astrophysics Data System (ADS)

Magal, E.; Weisbrod, N.; Yakirevich, A.; Kurtzman, D.; Yechieli, Y.

2009-12-01

A line source injection is suggested as an effective method for assessing groundwater velocities and flow directions in subsurface characterized by high water fluxes. Modifying the common techniques of injecting a tracer into a well was necessary after frequently-used methods of natural and forced gradient tracer tests ended with no reliable information on the local groundwater flow. In a field experiment, tracers were injected into 8-m long line injection system constructed below the water table almost perpendicular to the assumed flow direction. The injection system was divided to four separate segments (each 2 m long) enabling the injection of four different tracers along the line source. An array of five boreholes located in an area of 10x10 m downstream was used for monitoring the tracers' transport. Two dye tracers (Uranine and Na Naphthionate) were injected in a long pulse of several hours into two of the injection pipe segments and two tracers (Rhenium oxide and Gd-DTPA) were instantaneously injected to the other two segments. The tracers were detected 0.7 to 2.3 hours after injection in four of the five observation wells, located 2.3 to 10 m from the injection system, respectively. Groundwater velocities were calculated directly from the tracers' arrival times and by fitting the observed breakthrough curves to simulations with one and two dimensions analytical solutions for conservative tracer transport. The groundwater velocity was determined to be ~100 m/d. The longitudinal dispersivity value, generated from fitting the tracer breakthrough curves, was in a range of 0.2-3m. The groundwater flow direction was derived based on the arrival of the tracers and was found to be consistent with the apparent direction of the hydraulic gradient. The hydraulic conductivity derived from the groundwater velocity was ~1200 m/d, which is in the upper range of gravel sediment.

Simultaneous Determination of Fluid Shifts during Thermal Stress in a Small Animal Model,

DTIC Science & Technology

1985-09-01

extracellular fluid voitmie (BCF) was measured using a single injection c- inulin , technique, and plasma voilme (PV) was determined by ca.rdio--yreen dye...using tritiated water, extracell1ular fluid volume (ECF) was measured using a single injection C- inulin technique, and plasma volume (PV) was...space. However, inulin (10) has several advantages over the aforementioned because it Is not metabolized, stored, or incorporated by cells or

Long term effects of lipopolysaccharide on satellite glial cells in mouse dorsal root ganglia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blum, E.; Procacci, P.; Conte, V.

Lipopolysaccharide (LPS) has been used extensively to study neuroinflammation, but usually its effects were examined acutely (24 h<). We have shown previously that a single intraperitoneal LPS injection activated satellite glial cells (SGCs) in mouse dorsal root ganglia (DRG) and altered several functional parameters in these cells for at least one week. Here we asked whether the LPS effects would persist for 1 month. We injected mice with a single LPS dose and tested pain behavior, assessed SGCs activation in DRG using glial fibrillary acidic protein (GFAP) immunostaining, and injected a fluorescent dye intracellularly to study intercellular coupling. Electron microscopymore » was used to quantitate changes in gap junctions. We found that at 30 days post-LPS the threshold to mechanical stimulation was lower than in controls. GFAP expression, as well as the magnitude of dye coupling among SGCs were greater than in controls. Electron microscopy analysis supported these results, showing a greater number of gap junctions and an abnormal growth of SGC processes. These changes were significant, but less prominent than at 7 days post-LPS. We conclude that a single LPS injection exerts long-term behavioral and cellular changes. The results are consistent with the idea that SGC activation contributes to hyperalgesia. - Highlights: • A single lipopolysaccharides injection activated glia in mouse dorsal root ganglia for 30 days. • This was accompanied by increased communications by gap junctions among glia and by hyperalgesia. • Glial activation and coupling may contribute to chronic pain.« less

Power ultrasound-assisted cleaner leather dyeing technique: influence of process parameters.

PubMed

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2004-03-01

The application of power ultrasound to leather processing has a significant role in the concept of "clean technology" for leather production. The effect of power ultrasound in leather dyeing has been compared with dyeing in the absence of ultrasound and conventional drumming. The power ultrasound source used in these experiments was ultrasonic cleaner (150 W and 33 kHz). The effect of various process parameters such as amount of dye offer, temperature, and type of dye has been experimentally found out. The effect of presonication of dye solution as well as leather has been studied. Experiments at ultrasonic bath temperature were carried out to find out the combined thermal as well as stirring effects of ultrasound. Dyeing in the presence of ultrasound affords about 37.5 (1.8 times) difference as increase in % dye exhaustion or about 50% decrease in the time required for dyeing compared to dyeing in the absence of ultrasound for 4% acid red dye. About 29 (1.55 times) increase in % dye exhaustion or 30% reduction in time required for dyeing was observed using ultrasound at stationary condition compared with conventional dynamic drumming conditions. The effect of ultrasound at constant temperature conditions with a control experiment has also been studied. The dye exhaustion increases as the temperature increases (30-60 degrees C) and better results are observed at higher temperature due to the use of ultrasound. Presonication of dye solution or crust leather prior to the dyeing process has no significant improvement in dye exhaustion, suggesting ultrasound effect is realized when it is applied during the dyeing process. The results indicate that 1697 and 1416 ppm of dye can be reduced in the spent liquor due to the use of ultrasound for acid red (for 100 min) and acid black (for 3 h) dyes, respectively, thereby reducing the pollution load in the effluent stream. The color yield of the leather as inferred from the reflectance measurement indicates that dye offer can be halved when ultrasound is employed to promote dyeing. Scanning electron microscopy analysis of the cross section of the dyed leather indicates that fiber structure is not affected due to the use of ultrasound under the given process conditions. The present study clearly demonstrates that ultrasound can be used as a tool to improve the rate of exhaustion of dye, reduce pollution load in the spent effluent liquor, and improve the quality of leather produced. The study also offered provision to employ optimum levels of chemicals and increases percentage exhaustion for a given time, thereby limiting the pollution load in the tannery effluent, which is of great social concern.

A Molecular Reaction Cycle with a Solvatochromic Merocyanine Dye: An Experiment in Photochemistry, Kinetics, and Catalysis.

ERIC Educational Resources Information Center

Abdel-Kader, M. H.; Steiner, U.

1983-01-01

Three experiments using merocyanine M suitable as an integrated laboratory experience for undergraduates are described. Experiments demonstrate: complete molecular cycle composed of photochemical, thermal, and protolytic reaction steps; kinetics of cis-trans isomerization of the dye; and mechanism of base catalysis for thermal isomerization of the…

Application of response surface methodology (RSM) for the removal of methylene blue dye from water by nano zero-valent iron (NZVI).

PubMed

Khosravi, Morteza; Arabi, Simin

In this study, iron zero-valent nanoparticles were synthesized, characterized and studied for removal of methylene blue dye in water solution. The reactions were mathematically described as the function of parameters such as nano zero-valent iron (NZVI) dose, pH, contact time and initial dye concentration, and were modeled by the use of response surface methodology. These experiments were carried out as a central composite design consisting of 30 experiments determined by the 2(4) full factorial designs with eight axial points and six center points. The results revealed that the optimal conditions for dye removal were NZVI dose 0.1-0.9 g/L, pH 3-11, contact time 20-100 s, and initial dye concentration 10-50 mg/L, respectively. Under these optimal values of process parameters, the dye removal efficiency of 92.87% was observed, which very close to the experimental value (92.21%) in batch experiment. In the optimization, R(2) and R(2)adj correlation coefficients for the model were evaluated as 0.96 and 0.93, respectively.

Clean Photothermal Heating and Controlled Release from Near-Infrared Dye Doped Nanoparticles without Oxygen Photosensitization.

PubMed

Guha, Samit; Shaw, Scott K; Spence, Graeme T; Roland, Felicia M; Smith, Bradley D

2015-07-21

The photothermal heating and release properties of biocompatible organic nanoparticles, doped with a near-infrared croconaine (Croc) dye, were compared with analogous nanoparticles doped with the common near-infrared dyes ICG and IR780. Separate formulations of lipid-polymer hybrid nanoparticles and liposomes, each containing Croc dye, absorbed strongly at 808 nm and generated clean laser-induced heating (no production of (1)O2 and no photobleaching of the dye). In contrast, laser-induced heating of nanoparticles containing ICG or IR780 produced reactive (1)O2, leading to bleaching of the dye and also decomposition of coencapsulated payload such as the drug doxorubicin. Croc dye was especially useful as a photothermal agent for laser-controlled release of chemically sensitive payload from nanoparticles. Solution state experiments demonstrated repetitive fractional release of water-soluble fluorescent dye from the interior of thermosensitive liposomes. Additional experiments used a focused laser beam to control leakage from immobilized liposomes with very high spatial and temporal precision. The results indicate that fractional photothermal leakage from nanoparticles doped with Croc dye is a promising method for a range of controlled release applications.

Clean Photothermal Heating and Controlled Release From Near Infrared Dye Doped Nanoparticles Without Oxygen Photosensitization

PubMed Central

Guha, Samit; Shaw, Scott K.; Spence, Graeme T.; Roland, Felicia M.; Smith, Bradley D.

2015-01-01

The photothermal heating and release properties of biocompatible organic nanoparticles, doped with a near-infrared croconaine (Croc) dye, were compared with analogous nanoparticles doped with the common near-infrared dyes ICG and IR780. Separate formulations of lipid-polymer-hybrid nanoparticles and liposomes, each containing Croc dye, absorbed strongly at 808 nm and generated clean laser-induced heating (no production of 1O2 and no photobleaching of the dye). In contrast, laser-induced heating of nanoparticles containing ICG or IR780 produced reactive 1O2 leading to bleaching of the dye and also decomposition of co-encapsulated payload such as the drug Doxorubicin. Croc dye was especially useful as a photothermal agent for laser controlled release of chemically sensitive payload from nanoparticles. Solution state experiments demonstrated repetitive fractional release of water soluble fluorescent dye from the interior of thermosensitive liposomes. Additional experiments used a focused laser beam to control leakage from immobilized liposomes with very high spatial and temporal precision. The results indicate that fractional photothermal leakage from nanoparticles doped with Croc dye is a promising method for a range of controlled release applications. PMID:26149326

Self-sustained radial oscillating flows between parallel disks

NASA Astrophysics Data System (ADS)

Mochizuki, S.; Yang, W.-J.

1985-05-01

It is pointed out that radial flow between parallel circular disks is of interest in a number of physical systems such as hydrostatic air bearings, radial diffusers, and VTOL aircraft with centrally located downward-positioned jets. The present investigation is concerned with the problem of instability in radial flow between parallel disks. A time-dependent numerical study and experiments are conducted. Both approaches reveal the nucleation, growth, migration, and decay of annular separation bubbles (i.e. vortex or recirculation zones) in the laminar-flow region. A finite-difference technique is utilized to solve the full unsteady vorticity transport equation in the theoretical procedure, while the flow patterns in the experiments are visualized with the aid of dye-injection, hydrogen-bubble, and paraffin-mist methods. It is found that the separation and reattachment of shear layers in the radial flow through parallel disks are unsteady phenomena. The sequence of nucleation, growth, migration, and decay of the vortices is self-sustained.

Adsorption of a Textile Dye on Commercial Activated Carbon: A Simple Experiment to Explore the Role of Surface Chemistry and Ionic Strength

ERIC Educational Resources Information Center

Martins, Angela; Nunes, Nelson

2015-01-01

In this study, an adsorption experiment is proposed using commercial activated carbon as adsorbent and a textile azo dye, Mordant Blue-9, as adsorbate. The surface chemistry of the activated carbon is changed through a simple oxidation treatment and the ionic strength of the dye solution is also modified, simulating distinct conditions of water…

Design and characterization of poly(dimethylsiloxane)-based valves for interfacing continuous-flow sampling to microchip electrophoresis.

PubMed

Li, Michelle W; Huynh, Bryan H; Hulvey, Matthew K; Lunte, Susan M; Martin, R Scott

2006-02-15

This work describes the fabrication and evaluation of a poly(dimethyl)siloxane (PDMS)-based device that enables the discrete injection of a sample plug from a continuous-flow stream into a microchannel for subsequent analysis by electrophoresis. Devices were fabricated by aligning valving and flow channel layers followed by plasma sealing the combined layers onto a glass plate that contained fittings for the introduction of liquid sample and nitrogen gas. The design incorporates a reduced-volume pneumatic valve that actuates (on the order of hundreds of milliseconds) to allow analyte from a continuously flowing sampling channel to be injected into a separation channel for electrophoresis. The injector design was optimized to include a pushback channel to flush away stagnant sample associated with the injector dead volume. The effect of the valve actuation time, the pushback voltage, and the sampling stream flow rate on the performance of the device was characterized. Using the optimized design and an injection frequency of 0.64 Hz showed that the injection process is reproducible (RSD of 1.77%, n = 15). Concentration change experiments using fluorescein as the analyte showed that the device could achieve a lag time as small as 14 s. Finally, to demonstrate the potential uses of this device, the microchip was coupled to a microdialysis probe to monitor a concentration change and sample a fluorescein dye mixture.

Comparison of 2- and 4-wavelength methods for the optical detection of sentinel lymph node

NASA Astrophysics Data System (ADS)

Tellier, F.; Simon, H.; Blé, F. X.; Ravelo, R.; Chabrier, R.; Steibel, J.; Rodier, J. F.; Poulet, P.

2011-07-01

Sentinel lymph node biopsy is the gold standard method to detect a metastatic invasion from the primary breast cancer. This method can avoid patients to be submitted to full axillary chain dissection. In this study we present and compare two near-infrared optical probes for the sentinel lymph node detection, based on the recording of scattered photons. The two setups were developed to improve the detection of the dye injected in clinical routine: the Patent Blue V dye. Herein, we present results regarding clinical ex-vivo detection of sentinel lymph node after different volume injections. We have previously published results obtained with a two-wavelength probe on phantom and animal models. However this first generation device did not completely account for the optical absorption variations from biological tissue. Thus, a second generation probe has been equipped with four wavelengths. The dye concentration computation is then more robust to measurement and tissue property fluctuations. The detection threshold of the second setup was estimated at 8.10-3μmol/L, which is about 37 times lower than the eye visibility threshold. We present here the preliminary results and demonstrate the advantages of using four wavelengths compared to two on phantom suspensions simulating the optical properties of breast tissues.

Estimation of the dilution field near a marine outfall by using effluent turbidity as an environmental tracer and comparison with dye tracer data.

PubMed

Pecly, José Otavio Goulart

2018-01-01

The alternative use of effluent turbidity to determine the dilution field of a domestic marine outfall located off the city of Rio de Janeiro was evaluated through field work comprising fluorescent dye tracer injection and tracking with simultaneous monitoring of sea water turbidity. A preliminary laboratory assessment was carried out with a sample of the outfall effluent whose turbidity was measured by the nephelometric method before and during a serial dilution process. During the field campaign, the dye tracer was monitored with field fluorometers and the turbidity was observed with an optical backscattering sensor interfaced to an OEM data acquisition system. About 4,000 samples were gathered, covering an area of 3 km × 3 km near the outfall diffusers. At the far field - where a drift towards the coastline was observed - the effluent plume was adequately labeled by the dye tracer. The turbidity plume was biased due to the high and variable background turbidity of sea water. After processing the turbidity dataset with a baseline detrending method, the plume presented high correlation with the dye tracer plume drawn on the near dilution field. However, dye tracer remains more robust than effluent turbidity.

Electronic structure of the indium tin oxide/nanocrystalline anatase (TiO2)/ruthenium-dye interfaces in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Lyon, J. E.; Rayan, M. K.; Beerbom, M. M.; Schlaf, R.

2008-10-01

The electronic structure of two interfaces commonly found in dye-sensitized photovoltaic cells based on nanocrystalline anatase TiO2 ("Grätzel cells") was investigated using photoemission spectroscopy (PES). X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements were carried out on the indium tin oxide (ITO)/TiO2 and the TiO2/cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)bis-tetrabutylammonium dye ("N719" or "Ruthenium 535-bisTBA") interfaces. Both contacts were investigated using a multistep deposition procedure where the entire structure was prepared in vacuum using electrospray deposition. In between deposition steps the surface was characterized with XPS and UPS resulting in a series of spectra, allowing the determination of the orbital and band lineup at the interfaces. The results of these efforts confirm previous PES measurements on TiO2/dye contacts prepared under ambient conditions, suggesting that ambient contamination might not have significant influence on the electronic structure at the dye/TiO2 interface. The results also demonstrate that there may be a significant barrier for electron injection at the sputtered ITO/TiO2 interface and that this interface should be viewed as a semiconductor heterojunction rather than as metal-semiconductor (Schottky) contact.

Retinal Toxicity of Acai Fruit (Euterpe Oleracea) Dye Concentrations in Rabbits: Basic Principles of a New Dye for Chromovitrectomy in Humans.

PubMed

Caiado, Rafael R; Peris, Cristiane S; Lima-Filho, Acácio Alves Souza; Urushima, Joao Guilherme Palma; Novais, Eduardo; Badaró, Emmerson; Maia, André; Sinigaglia-Coimbra, Rita; Watanabe, Sung Eun S; Rodrigues, Eduardo B; Farah, Michel Eid; Maia, Mauricio

2017-08-01

Evaluate toxicity of acai fruit (Euterpe oleracea) dye concentrations in a rabbit model. Rabbits were injected intravitreously with 10%, 25%, and 35% acai dye concentrations. Control eyes received balanced salt solution (BSS). Electroretinogram (ERG), fundus imaging, fluorescein angiography (FA), optical coherence tomography (OCT), and light and transmission electron microscopy (LM/TEM) were performed. Fundus imaging showed increased vitreous opacity with increased dye concentrations. FA and OCT showed normality with all concentrations. Comparisons between BSS and dye concentrations were analyzed using Kruskal-Wallis and Mood's median test (p < 0.05). At 24 h, ERGs showed reduced amplitudes from baseline in all eyes. Median b-wave amplitudes nonsignificantly decreased and latency increased with 10% and 25%; findings were significant (p < 0.05) for 35%. LM and TEM showed no abnormalities for 10% and 25%. With 35%, TEM showed ganglion cell edema at 24 h that resolved after 7 days. Vacuolization, multilamellar bodies, and nerve bundle damage occurred at 24 h/7 days in the inner nuclear layer. Mitochondrial cristae disruption occurred in the inner photoreceptor segment at 24 h that decreased by 7 days. Ten and twenty-five percent concentrations were safe and may improve identification of the posterior hyaloid and internal limiting membrane during chromovitrectomy in humans.

Dynamic Flow Velocity Mapping from Fluorescent Dye Transit Times in the Brain Surface Microcirculation of Anesthetized Rats and Mice.

PubMed

Hoshikawa, Ryo; Kawaguchi, Hiroshi; Takuwa, Hiroyuki; Ikoma, Yoko; Tomita, Yutaka; Unekawa, Miyuki; Suzuki, Norihiro; Kanno, Iwao; Masamoto, Kazuto

2016-08-01

This study aimed to develop a new method for mapping blood flow velocity based on the spatial evolution of fluorescent dye transit times captured with CLSFM in the cerebral microcirculation of anesthetized rodents. The animals were anesthetized with isoflurane, and a small amount of fluorescent dye was intravenously injected to label blood plasma. The CLSFM was conducted through a closed cranial window to capture propagation of the dye in the cortical vessels. The transit time of the dye over a certain distance in a single vessel was determined with automated image analyses, and average flow velocity was mapped in each vessel. The average flow velocity measured in the rat pial artery and vein was 4.4 ± 1.2 and 2.4 ± 0.5 mm/sec, respectively. A similar range of flow velocity to those of the rats was observed in the mice; 4.9 ± 1.4 and 2.0 ± 0.9 mm/sec, respectively, although the vessel diameter in the mice was about half of that in the rats. Flow velocity in the cerebral microcirculation can be mapped based on fluorescent dye transit time measurements with conventional CLSFM in experimental animals. © 2016 John Wiley & Sons Ltd.

Multispectral photoacoustic decomposition with localized regularization for detecting targeted contrast agent

NASA Astrophysics Data System (ADS)

Tavakoli, Behnoosh; Chen, Ying; Guo, Xiaoyu; Kang, Hyun Jae; Pomper, Martin; Boctor, Emad M.

2015-03-01

Targeted contrast agents can improve the sensitivity of imaging systems for cancer detection and monitoring the treatment. In order to accurately detect contrast agent concentration from photoacoustic images, we developed a decomposition algorithm to separate photoacoustic absorption spectrum into components from individual absorbers. In this study, we evaluated novel prostate-specific membrane antigen (PSMA) targeted agents for imaging prostate cancer. Three agents were synthesized through conjugating PSMA-targeting urea with optical dyes ICG, IRDye800CW and ATTO740 respectively. In our preliminary PA study, dyes were injected in a thin wall plastic tube embedded in water tank. The tube was illuminated with pulsed laser light using a tunable Q-switch ND-YAG laser. PA signal along with the B-mode ultrasound images were detected with a diagnostic ultrasound probe in orthogonal mode. PA spectrums of each dye at 0.5 to 20 μM concentrations were estimated using the maximum PA signal extracted from images which are obtained at illumination wavelengths of 700nm-850nm. Subsequently, we developed nonnegative linear least square optimization method along with localized regularization to solve the spectral unmixing. The algorithm was tested by imaging mixture of those dyes. The concentration of each dye was estimated with about 20% error on average from almost all mixtures albeit the small separation between dyes spectrums.

Comparison of a chimeric anti-carcinoembryonic antigen antibody conjugated with visible or near-infrared fluorescent dyes for imaging pancreatic cancer in orthotopic nude mouse models

NASA Astrophysics Data System (ADS)

Maawy, Ali A.; Hiroshima, Yukihiko; Kaushal, Sharmeela; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

2013-12-01

The aim of this study was to evaluate a set of visible and near-infrared dyes conjugated to a tumor-specific chimeric antibody for high-resolution tumor imaging in orthotopic models of pancreatic cancer. BxPC-3 human pancreatic cancer was orthotopically implanted into pancreata of nude mice. Mice received a single intravenous injection of a chimeric anti-carcinoembryonic antigen antibody conjugated to one of the following fluorophores: 488-nm group (Alexa Fluor 488 or DyLight 488); 550-nm group (Alexa Fluor 555 or DyLight 550); 650-nm group (Alexa Fluor 660 or DyLight 650), or the 750-nm group (Alexa Fluor 750 or DyLight 755). After 24 h, the Olympus OV100 small-animal imaging system was used for noninvasive and intravital fluorescence imaging of mice. Dyes were compared with respect to depth of imaging, resolution, tumor-to-background ratio (TBR), photobleaching, and hemoglobin quenching. The longer wavelength dyes had increased depth of penetration and ability to detect the smallest tumor deposits and provided the highest TBRs, resistance to hemoglobin quenching, and specificity. The shorter wavelength dyes were more photostable. This study showed unique advantages of each dye for specific cancer imaging in a clinically relevant orthotopic model.

Design of new triphenylamine-sensitized solar cells: a theoretical approach.

PubMed

Preat, Julien; Jacquemin, Denis; Perpète, Eric A

2010-07-15

This work reports a theoretical study of the photovoltaic properties of a series of original conjugated metal-free organic dyes containing the triphenylamine (TPA) moiety. These compounds have recently been develop for dye sensitized solar cells (DSSCs). Our (TD)DFT-based procedure made it possible to get insights into the geometrical and electronic structures of the dyes and to unravel the structural modifications optimizing the properties of TPA-based DSSCs. In particular, we aimed at improving the electron injection process as well as the light harvesting efficiency of the dyes. On the other hand, molecular dynamic (MD) investigations of the kinetics of the regeneration step have been performed for both "classical" (CHCl(3)/I(3)(-)/I(-)/Li(+)) and iodide imidazolium-based solvent-free electrolytes (DMII(+)/I(-)). The MD simulations helped to understand the regeneration mechanism for the solvent-free electrolyte: it combines the DMII(+)/DMII(0) couple to the I(3)(-)/I(-) redox system which acts as a "mediator".

An enhanced mangiferaindica for dye sensitized solar cell application

NASA Astrophysics Data System (ADS)

Uno, U. E.; Emetere, M. E.; Fadipe, L. A.; Oluranti, Jonathan

2016-02-01

Titanium dioxide (T1O2) is preferred to Zinc oxide as mesoporous oxide layer because it raised the efficiency of DSSCs from 1% to 7%. The chemistry of the process however seem rigorous to allow the light induced electron injection from the adsorbed dye into the nanocrystallites i.e. which renders the TiO2 conductive. The DSSC fabricated consist of 2.25 cm2 active area of titanium dioxide coated on FTO glass (fluorine tin oxide) immersed in ethanol solution of natural dye extracted as an anode (electrode) and counter electrode. These two electrodes were coupled together and the space between them was filled with the Iodolyte AN-50 as solid electrolyte or redox mediator. The photo electrochemical parameters of the dye extracted (Mango fruit Peel) from the results obtained are short circuit current (Isc)= 1.22×10-2, current density (Jsc)=4.07×10-2, open circuit voltage (voc) =0.53V, fill factor (FF) of 0.16 and the overall conversion efficiency (Eff) =0.345%.

Accuracy of acromioclavicular joint injections.

PubMed

Wasserman, Bradley R; Pettrone, Sarah; Jazrawi, Laith M; Zuckerman, Joseph D; Rokito, Andrew S

2013-01-01

Injection to the acromioclavicular (AC) joint can be both diagnostic and therapeutic. The purpose of this study was to evaluate the accuracy of in vivo AC joint injections. Case series; Level of evidence, 4. Thirty patients with pain localized to the AC joint were injected with 1 mL of 1% lidocaine and 0.5 mL of radiographic contrast material (Isovue). Radiographs of the AC joint were taken after the injection. Each radiograph was reviewed by a musculoskeletal radiologist and graded as intra-articular, extra-articular, or partially intra-articular. Of the 30 injections performed, 13 (43.3%) were intra-articular, 7 (23.3%) were partially articular, and 10 (33.3%) were extra-articular. When the intra-articular and the partially articular groups were combined, 20 patients (66.7%) had some contrast dye in the AC joint. This study demonstrates that despite the relatively superficial location of the AC joint, the clinical accuracy of AC joint injections remains relatively low.

CAPILLARY ELECTROPHORESIS/LASER-INDUCED FLUORESCENCE DETECTION OF FLUORESCEIN AS A GROUNDWATER MIGRATION TRACER

EPA Science Inventory

Capillary electrophoresis (CE) has been applied to the determination of the groundwater migration tracer dye fluorescein based on laser-induced fluorescence (LIF) detection and compared to determinations obtained with traditional spectrofluorimetry. Detection limits of injected d...

The Cross Surfzone/Inner-shelf Dye Exchange (CSIDE) Experiment Overview: Binational Dye Tracer Releases to Study Pollution Transport and Dilution.

NASA Astrophysics Data System (ADS)

Feddersen, F.; Giddings, S. N.; Kumar, N.; Grimes, D. J.; Pawlak, G. R.; Rivas, D.; Diaz, M.

2016-02-01

Per square km, the surfzone and inner-shelf are by far the most economically and ecologically important ocean regions, vital for recreation, food, and ecosystem services. Despite the importance of clean coastal waters to our economy and well-being, declining water quality threatens coastal ecosystem and human health worldwide. Healthy coasts are a significant priority to federal agencies, local government, and NGOs. In particular the San Diego US and Tijuana Mexico border region have unique and persistent water quality issues due to a range of pollution sources. Cross-shore exchange of tracers (e.g., pathogens, anthropogenic nutrients, harmful algal blooms - HABs, larvae) between the well-mixed surfzone and stratified inner-shelf is poorly understood. The surfzone, inner- and mid-shelf span drastically different dynamical regimes, with varying cross-shelf exchange mechanisms due to wave, wind, buoyancy, and tidal processes and intrinsic variability. The NSF funded CSIDE (Cross Surfzone/Inner-shelf Dye Exchange) experiment (Sept & Oct 2015) aims to increase our understanding of cross-shelf material exchange by performing 3 shoreline dye release experiments that are tracked for up to 20 km alongshore and over 48+ hrs. One dye release will be performed in Mexico and the dye transport tracked across the border. The dye will be tracked via a broad range of binational instrumentation. In this presentation, we present an overview of the CSIDE experiment, in particular the binational aspects of the study,

Spectrally resolved visualization of fluorescent dyes permeating into skin

NASA Astrophysics Data System (ADS)

Maeder, Ulf; Bergmann, Thorsten; Beer, Sebastian; Burg, Jan Michael; Schmidts, Thomas; Runkel, Frank; Fiebich, Martin

2012-03-01

We present a spectrally resolved confocal imaging approach to qualitatively asses the overall uptake and the penetration depth of fluorescent dyes into biological tissue. We use a confocal microscope with a spectral resolution of 5 nm to measure porcine skin tissue after performing a Franz-Diffusion experiment with a submicron emulsion enriched with the fluorescent dye Nile Red. The evaluation uses linear unmixing of the dye and the tissue autofluorescence spectra. The results are combined with a manual segmentation of the skin's epidermis and dermis layers to assess the penetration behavior additionally to the overall uptake. The diffusion experiments, performed for 3h and 24h, show a 3-fold increased dye uptake in the epidermis and dermis for the 24h samples. As the method is based on spectral information it does not face the problem of superimposed dye and tissue spectra and therefore is more precise compared to intensity based evaluation methods.

Dyes, Fibers, and Paper: A Botany Lab Exercise for Non-Biology Majors

ERIC Educational Resources Information Center

Egan, Todd P.; Meekins, J. Forrest; Maluso, Diane

2004-01-01

This laboratory exercise affords students a hands-on experience learning about traditional dyes, fiber strength, and paper making. It is economical, simple to prepare, provides satisfactory results, and is student friendly. Dyes were extracted from plant leaves, stems, roots, and fruits. Hard-boiled eggs were place in the dyes for 15 minutes to…

Monitoring Ultrafast Chemical Dynamics by Time-Domain X-ray Photo- and Auger-Electron Spectroscopy.

PubMed

Gessner, Oliver; Gühr, Markus

2016-01-19

The directed flow of charge and energy is at the heart of all chemical processes. Extraordinary efforts are underway to monitor and understand the concerted motion of electrons and nuclei with ever increasing spatial and temporal sensitivity. The element specificity, chemical sensitivity, and temporal resolution of ultrafast X-ray spectroscopy techniques hold great promise to provide new insight into the fundamental interactions underlying chemical dynamics in systems ranging from isolated molecules to application-like devices. Here, we focus on the potential of ultrafast X-ray spectroscopy techniques based on the detection of photo- and Auger electrons to provide new fundamental insight into photochemical processes of systems with various degrees of complexity. Isolated nucleobases provide an excellent testing ground for our most fundamental understanding of intramolecular coupling between electrons and nuclei beyond the traditionally applied Born-Oppenheimer approximation. Ultrafast electronic relaxation dynamics enabled by the breakdown of this approximation is the major component of the nucleobase photoprotection mechanisms. Transient X-ray induced Auger electron spectroscopy on photoexcited thymine molecules provides atomic-site specific details of the extremely efficient coupling that converts potentially bond changing ultraviolet photon energy into benign heat. In particular, the time-dependent spectral shift of a specific Auger band is sensitive to the length of a single bond within the molecule. The X-ray induced Auger transients show evidence for an electronic transition out of the initially excited state within only ∼200 fs in contrast to theoretically predicted picosecond population trapping behind a reaction barrier. Photoinduced charge transfer dynamics between transition metal complexes and semiconductor nanostructures are of central importance for many emerging energy and climate relevant technologies. Numerous demonstrations of photovoltaic and photocatalytic activity have been performed based on the combination of strong light absorption in dye molecules with charge separation and transport in adjacent semiconductor nanostructures. However, a fundamental understanding of the enabling and limiting dynamics on critical atomic length- and time scales is often still lacking. Femtosecond time-resolved X-ray photoelectron spectroscopy is employed to gain a better understanding of a short-lived intermediate that may be linked to the unexpectedly limited performance of ZnO based dye-sensitized solar cells by delaying the generation of free charge carriers. The transient spectra strongly suggest that photoexcited dye molecules attached to ZnO nanocrystals inject their charges into the substrate within less than 1 ps but the electrons are then temporarily trapped at the surface of the semiconductor in direct vicinity of the injecting molecules. The experiments are extended to monitor the electronic response of the semiconductor substrate to the collective injection from a monolayer of dye molecules and the subsequent electron-ion recombination dynamics. The results indicate some qualitative similarities but quantitative differences between the recombination dynamics at molecule-semiconductor interfaces and previously studied bulk-surface electron-hole recombination dynamics in photoexcited semiconductors.

Heat tracer test in an alluvial aquifer: Field experiment and inverse modelling

NASA Astrophysics Data System (ADS)

Klepikova, Maria; Wildemeersch, Samuel; Hermans, Thomas; Jamin, Pierre; Orban, Philippe; Nguyen, Frédéric; Brouyère, Serge; Dassargues, Alain

2016-09-01

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in an injection well and monitoring the evolution of groundwater temperature and tracer concentration in the pumping well and in measurement intervals. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells closely spaced along three transects were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume is explained by the groundwater flow gradient on the site and heterogeneities in the hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with a pilot point approach for inversion of the hydraulic conductivity field, the main preferential flow paths were delineated. The successful application of a field heat tracer test at this site suggests that heat tracer tests is a promising approach to image hydraulic conductivity field. This methodology could be applied in aquifer thermal energy storage (ATES) projects for assessing future efficiency that is strongly linked to the hydraulic conductivity variability in the considered aquifer.

Determination of the orientation of fluorescent labels relative to myosin S1 in solution from time-resolved fluorescence anisotropy experiments

NASA Astrophysics Data System (ADS)

van der Heide, Uulke A.; Gerritsen, Hans C.; Trayer, Ian P.; Levine, Yehudi K.

1992-04-01

The time-resolved fluorescence anisotropy of myosin S1 covalently labeled with Eosin-5- maleimide and 1,5-I-AEDANS was measured in solution. Each probe was specifically attached at one SH-group on the S1. The two most reactive SH sites on the heavy chain of the myosin S1 were used. The fluorescence anisotropy was measured at different excitation wavelengths. In this way, several absorption moments were utilized, each having a distinct orientation in the frame of the dye. The orientations of the transition moments in the dyes were determined in a separate experiment using an angle resolved fluorescence depolarization experiment on dyes embedded in stretched matrices of PVA polymers. The anisotropy decay curves exhibit fast (<3 ns) and slow (> 100 ns) components. The slow decay components reflect the motion of the large protein molecules. The fast anisotropy decay are attributed to a fast, but restricted, motion of the bound dye relative to the protein as experiments on free dyes in solution reveal subnanosecond anisotropy decays. The anisotropy decays have been analyzed in terms of a model which describes the restricted motion of the dye molecule relative to the protein and the overall rotation of the dye-protein complex in solution. An important element in the model is the incorporation of the orientational distribution of the dye relative to the protein. The observed anisotropy decays were analyzed using a global target approach in which the experimental data obtained at different excitation wavelengths are fitted simultaneously to the theoretical model. It is important to note that the orientational distribution of the dye relative to the protein, as well as the rotational correlation times of the motions for a dye attached to a given binding site, are independent of the excitation wavelength used. This leads to a reduction in the number of independent parameters optimized by the nonlinear least squares procedure. The orientational distribution of the dye relative to the protein obtained in this way is particularly useful for the interpretation of fluorescence depolarization data obtained from labeled muscle fibers. Indeed, knowledge of the distribution function of a dye attached to a binding site of the S1 protein is a prerequisite for a probe-independent determination of the orientational distribution of the S1 proteins themselves in the muscle fiber.

Cannula Versus Sharp Needle for Placement of Soft Tissue Fillers: An Observational Cadaver Study.

PubMed

van Loghem, Jani A J; Humzah, Dalvi; Kerscher, Martina

2017-12-13

Soft-tissue fillers have become important products for facial rejuvenation. Deep fat compartments and facial bones lose volume during the natural aging process. For the most natural-looking results, deep volumetric injections at strategic sites are therefore preferred. Supraperiosteal placement is performed with a sharp needle or a non-traumatic cannula. The primary objective was to determine whether there is a difference in precision between supraperiosteal placement with a sharp needle compared with a non-traumatic cannula in cadaver specimens. A secondary objective was to analyze the safety profiles of both injection techniques. Cadaver heads were injected with dye material and soft-tissue fillers at multiple aesthetic facial sites on the supraperiosteum and subsequently dissected for observation of dye and filler placement. The non-traumatic cannula technique resulted in product being confined to the deep anatomic layers. In contrast, with the sharp needle technique, material was placed in multiple anatomic layers, from the periosteum to more superficial skin layers. For both techniques results were consistent for all facial sites. Although direct extrapolation from cadavers to the in vivo situation cannot be made, cannulae showed more precision in placement of product. With the sharp needle, the material was injected on the periosteum, and then migrated in a retrograde direction along the trajectory of the needle path, ending up in multiple anatomic layers. The sharp needle technique also showed a higher complication risk with intra-arterial injection occurring, even though the needle tip was positioned on the periosteum and the product was injected with the needle in constant contact with the periosteum. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Compact Ozone Differential Absorption Lidar (DIAL) Transmitter Using Solid-State Dye Polymers

NASA Technical Reports Server (NTRS)

Jones, Alton L., Jr.; DeYoung, Russell J.; Elsayid-Ele, Hani

2001-01-01

A new potential DIAL laser transmitter is described that uses solid-state dye laser materials to make a simpler, more compact, lower mass laser system. Two solid-state dye laser materials were tested to evaluate their performance in a laser oscillator cavity end pumped by a pulsed Nd:YAG laser at 532 nm. The polymer host polymethyl-methacrylate was injected with a pyrromethene laser dye, PM 580, or PM 597. A narrowband laser oscillator cavity was constructed to produce visible wavelengths of 578 and 600 nm which were frequency doubled into the UV region (299 or 300 nm) by using a BBO crystal, resulting in a maximum energy of 11 mJ at a wavelength of 578 nm when pumped by the Nd:YAG laser at an energy of 100 mJ (532 nm). A maximum output energy of 378 microJ was achieved in the UV region at a wavelength of 289 nm but lasted only 2000 laser shots at a repetition rate of 10 Hz. The results are promising and show that a solid-state dye laser based ozone DIAL system is possible with improvements in the design of the laser transmitter.

Direct grafting of long-lived luminescent indicator dyes to GaN light-emitting diodes for chemical microsensor development.

PubMed

López-Gejo, Juan; Navarro-Tobar, Álvaro; Arranz, Antonio; Palacio, Carlos; Muñoz, Elías; Orellana, Guillermo

2011-10-01

Two new methods for covalent functionalization of GaN based on plasma activation of its surface are presented. Both of them allow attachment of sulfonated luminescent ruthenium(II) indicator dyes to the p- and n-type semiconductor as well as to the surface of nonencapsulated chips of GaN light-emitting diodes (blue LEDs). X-ray photoelectron spectroscopy analysis of the functionalized semiconductor confirms the formation of covalent bonds between the GaN surface and the dye. Confocal fluorescence microscopy with single-photon-timing (SPT) detection has been used for characterization of the functionalized surfaces and LED chips. While the ruthenium complex attached to p-GaN under an oxygen-free atmosphere gives significantly long mean emission lifetimes for the indicator dye (ca. 2000 ns), the n-GaN-functionalized surfaces display surprisingly low values (600 ns), suggesting the occurrence of a quenching process. A photoinduced electron injection from the dye to the semiconductor conduction band, followed by a fast back electron transfer, is proposed to be responsible for the excited ruthenium dye deactivation. This process invalidates the use of the n-GaN/dye system for sensing applications. However, for p-GaN/dye materials, the luminescence decay accelerates in the presence of O(2). The moderate sensitivity is attributed to the fact that only a monolayer of indicator dye is anchored to the semiconductor surface but serves as a demonstrator device. Moreover, the luminescence decays of the functionalized LED chip measured with excitation of either an external (laser) source or the underlying LED emission (from p-GaN/InGaN quantum wells) yield the same mean luminescence lifetime. These results pave the way for using advanced LEDs to develop integrateable optochemical microsensors for gas analysis. © 2011 American Chemical Society

Sensitization of Nanocrystalline Metal Oxides with a Phosphonate-Functionalized Perylene Diimide for Photoelectrochemical Water Oxidation with a CoOx Catalyst.

PubMed

Kirner, Joel T; Finke, Richard G

2017-08-23

A planar organic thin film composed of a perylene diimide dye (N,N'-bis(phosphonomethyl)-3,4,9,10-perylenediimide, PMPDI) with photoelectrochemically deposited cobalt oxide (CoO x ) catalyst was previously shown to photoelectrochemically oxidize water (DOI: 10.1021/am405598w). Herein, the same PMPDI dye is studied for the sensitization of different nanostructured metal oxide (nano-MO x ) films in a dye-sensitized photoelectrochemical cell architecture. Dye adsorption kinetics and saturation decreases in the order TiO 2 > SnO 2 ≫ WO 3 . Despite highest initial dye loading on TiO 2 films, photocurrent with hydroquinone (H 2 Q) sacrificial reductant in pH 7 aqueous solution is much higher on SnO 2 films, likely due to a higher driving force for charge injection into the more positive conduction band energy of SnO 2 . Dyeing conditions and SnO 2 film thickness were subsequently optimized to achieve light-harvesting efficiency >99% at the λ max of the dye, and absorbed photon-to-current efficiency of 13% with H 2 Q, a 2-fold improvement over the previous thin-film architecture. A CoO x water-oxidation catalyst was photoelectrochemically deposited, allowing for photoelectrochemical water oxidation with a faradaic efficiency of 31 ± 7%, thus demonstrating the second example of a water-oxidizing, dye-sensitized photoelectrolysis cell composed entirely of earth-abundant materials. However, deposition of CoO x always results in lower photocurrent due to enhanced recombination between catalyst and photoinjected electrons in SnO 2 , as confirmed by open-circuit photovoltage measurements. Possible future studies to enhance photoanode performance are discussed, including alternative catalyst deposition strategies or structural derivatization of the perylene dye.

Sensitization of Nanocrystalline Metal Oxides with a Phosphonate-Functionalized Perylene Diimide for Photoelectrochemical Water Oxidation with a CoO x Catalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirner, Joel T.; Finke, Richard G.

A planar organic thin film composed of a perylene diimide dye (N,N'-bis(phosphonomethyl)-3,4,9,10-perylenediimide, PMPDI) with photoelectrochemically deposited cobalt oxide (CoO x) catalyst was previously shown to photoelectrochemically oxidize water (DOI: 10.1021/am405598w). Herein, the same PMPDI dye is studied for the sensitization of different nanostructured metal oxide (nano-MO x) films in a dye-sensitized photoelectrochemical cell architecture. Dye adsorption kinetics and saturation decreases in the order TiO 2 > SnO 2 >> WO 3. Despite highest initial dye loading on TiO 2 films, photocurrent with hydroquinone (H 2Q) sacrificial reductant in pH 7 aqueous solution is much higher on SnO 2 films, likelymore » due to a higher driving force for charge injection into the more positive conduction band energy of SnO 2. Dyeing conditions and SnO 2 film thickness were subsequently optimized to achieve light-harvesting efficiency >99% at the λmax of the dye, and absorbed photon-to-current efficiency of 13% with H 2Q, a 2-fold improvement over the previous thin-film architecture. A CoO x water-oxidation catalyst was photoelectrochemically deposited, allowing for photoelectrochemical water oxidation with a faradaic efficiency of 31 ± 7%, thus demonstrating the second example of a water-oxidizing, dye-sensitized photoelectrolysis cell composed entirely of earth-abundant materials. However, deposition of CoO x always results in lower photocurrent due to enhanced recombination between catalyst and photoinjected electrons in SnO 2, as confirmed by open-circuit photovoltage measurements. Possible future studies to enhance photoanode performance are also discussed, including alternative catalyst deposition strategies or structural derivatization of the perylene dye.« less

Sensitization of Nanocrystalline Metal Oxides with a Phosphonate-Functionalized Perylene Diimide for Photoelectrochemical Water Oxidation with a CoO x Catalyst

DOE PAGES

Kirner, Joel T.; Finke, Richard G.

2017-07-20

A planar organic thin film composed of a perylene diimide dye (N,N'-bis(phosphonomethyl)-3,4,9,10-perylenediimide, PMPDI) with photoelectrochemically deposited cobalt oxide (CoO x) catalyst was previously shown to photoelectrochemically oxidize water (DOI: 10.1021/am405598w). Herein, the same PMPDI dye is studied for the sensitization of different nanostructured metal oxide (nano-MO x) films in a dye-sensitized photoelectrochemical cell architecture. Dye adsorption kinetics and saturation decreases in the order TiO 2 > SnO 2 >> WO 3. Despite highest initial dye loading on TiO 2 films, photocurrent with hydroquinone (H 2Q) sacrificial reductant in pH 7 aqueous solution is much higher on SnO 2 films, likelymore » due to a higher driving force for charge injection into the more positive conduction band energy of SnO 2. Dyeing conditions and SnO 2 film thickness were subsequently optimized to achieve light-harvesting efficiency >99% at the λmax of the dye, and absorbed photon-to-current efficiency of 13% with H 2Q, a 2-fold improvement over the previous thin-film architecture. A CoO x water-oxidation catalyst was photoelectrochemically deposited, allowing for photoelectrochemical water oxidation with a faradaic efficiency of 31 ± 7%, thus demonstrating the second example of a water-oxidizing, dye-sensitized photoelectrolysis cell composed entirely of earth-abundant materials. However, deposition of CoO x always results in lower photocurrent due to enhanced recombination between catalyst and photoinjected electrons in SnO 2, as confirmed by open-circuit photovoltage measurements. Possible future studies to enhance photoanode performance are also discussed, including alternative catalyst deposition strategies or structural derivatization of the perylene dye.« less

Sentinel lymph node biopsy under fluorescent indocyanin green guidance: Initial experience.

PubMed

Aydoğan, Fatih; Arıkan, Akif Enes; Aytaç, Erman; Velidedeoğlu, Mehmet; Yılmaz, Mehmet Halit; Sager, Muhammet Sait; Çelik, Varol; Uras, Cihan

2016-01-01

Sentinel lymph node biopsy can be applied by using either blue dye or radionuclide method or both in breast cancer. Fluorescent imaging with indocyanine green is a new defined method. This study evaluates the applicability of sentinel lymph node biopsy via fluorescent indocyanine green. IC-VIEW (Pulsion Medical Systems AG, Munich, Germany) infrared visualization system was used for imaging. Two mL of indocyanine green was injected to visualize sentinel lymph nodes. After injection, subcutaneous lymphatics were traced and sentinel lymph nodes were found with simultaneous imaging. Sentinel lymph nodes were excised under fluorescent light guidance, and excised lymph nodes were examined histopathologically. Patients with sentinel lymph node metastases underwent axillary dissection. Four patients with sentinel lymph node biopsy due to breast cancer were included in the study. Sentinel lymph nodes were visualized with indocyanine green in all patients. The median number of excised sentinel lymph node was 2 (2-3). Two patients with lymph node metastasis underwent axillary dissection. No metastasis was detected in lymph nodes other than the sentinel nodes in patients with axillary dissection. There was no complication during and after the operation related to the method. According to our limited experience, sentinel lymph node biopsy under fluorescent indocyanine green guidance, which has an advantage of simultaneous visualization, is technically feasible.

Application of the fiber-optic perfusion fluorometer to absorption and exsorption studies in hairless mouse skin.

PubMed

Shackleford, J M; Yielding, K L

1987-09-01

This study was undertaken to test the fiber-optic perfusion fluorometer as a direct means of evaluating skin absorption and exsorption in hairless mice. Skin-barrier compromise was accomplished in the absorption experiments by application of dimethyl sulfoxide to the skin surface or by partial removal of the stratum corneum with sticky tape. Absorbed fluorescein was measured easily in unanesthetized control (skin-barrier intact) and experimental mice. Unabsorbed chemical did not fluoresce 15 minutes after application, although it was present on the surface of the skin as a dry powder. The time course of fluorescein elimination from the skin was related to a rapid phase (vascular removal) and a slow phase (reservoir entrapment). In the exsorption experiments the fluorescein was injected intraperitoneally. Back skin on the right side was swabbed with either dimethyl sulfoxide or 1% capsaicin in alcohol prior to the injections, and differences in skin fluorescence on the left (control) and right sides were recorded. One application of dimethyl sulfoxide or capsaicin increased the level of skin exsorption. Three applications of dimethyl sulfoxide almost doubled the amount of exsorbed dye, whereas three applications of the capsaicin inhibited the exsorption process. It was concluded that the fiber-optic perfusion fluorometer provides an excellent technique in support of other methods of investigating the skin.

Development of type-I/type-II hybrid dye sensitizer with both pyridyl group and catechol unit as anchoring group for type-I/type-II dye-sensitized solar cell.

PubMed

Ooyama, Yousuke; Furue, Kensuke; Enoki, Toshiaki; Kanda, Masahiro; Adachi, Yohei; Ohshita, Joji

2016-11-09

A type-I/type-II hybrid dye sensitizer with a pyridyl group and a catechol unit as the anchoring group has been developed and its photovoltaic performance in dye-sensitized solar cells (DSSCs) is investigated. The sensitizer has the ability to adsorb on a TiO 2 electrode through both the coordination bond at Lewis acid sites and the bidentate binuclear bridging linkage at Brønsted acid sites on the TiO 2 surface, which makes it possible to inject an electron into the conduction band of the TiO 2 electrode by the intramolecular charge-transfer (ICT) excitation (type-I pathway) and by the photoexcitation of the dye-to-TiO 2 charge transfer (DTCT) band (type-II pathway). It was found that the type-I/type-II hybrid dye sensitizer adsorbed on TiO 2 film exhibits a broad photoabsorption band originating from ICT and DTCT characteristics. Here we reveal the photophysical and electrochemical properties of the type-I/type-II hybrid dye sensitizer bearing a pyridyl group and a catechol unit, along with its adsorption modes onto TiO 2 film, and its photovoltaic performance in type-I/type-II DSSC, based on optical (photoabsorption and fluorescence spectroscopy) and electrochemical measurements (cyclic voltammetry), density functional theory (DFT) calculation, FT-IR spectroscopy of the dyes adsorbed on TiO 2 film, photocurrent-voltage (I-V) curves, incident photon-to-current conversion efficiency (IPCE) spectra, and electrochemical impedance spectroscopy (EIS) for DSSC.

The state of the art of conventional flow visualization techniques for wind tunnel testing

NASA Technical Reports Server (NTRS)

Settles, G. S.

1982-01-01

Conventional wind tunnel flow visualization techniques which consist of surface flow methods, tracers, and optical methods are presented. Different surface flow methods are outlined: (1) liquid films (oil and fluorescent dye and UV lighting, renewable film via porous dispenser in model, volatile carrier fluid, cryogenic colored oil dots, oil film interferometry); (2) reactive surface treatment (reactive gas injection, reversible dye); (3) transition and heat transfer detectors (evaporation, sublimation, liquid crystals, phase change paints, IR thermography); and (4) tufts (fluorescent mini tufts, cryogenic suitability). Other methods are smoke wire techniques, vapor screens, and optical methods.

Optimization of Glioblastoma Mouse Orthotopic Xenograft Models for Translational Research.

PubMed

Irtenkauf, Susan M; Sobiechowski, Susan; Hasselbach, Laura A; Nelson, Kevin K; Transou, Andrea D; Carlton, Enoch T; Mikkelsen, Tom; deCarvalho, Ana C

2017-08-01

Glioblastoma is an aggressive primary brain tumor predominantly localized to the cerebral cortex. We developed a panel of patient-derived mouse orthotopic xenografts (PDOX) for preclinical drug studies by implanting cancer stem cells (CSC) cultured from fresh surgical specimens intracranially into 8-wk-old female athymic nude mice. Here we optimize the glioblastoma PDOX model by assessing the effect of implantation location on tumor growth, survival, and histologic characteristics. To trace the distribution of intracranial injections, toluidine blue dye was injected at 4 locations with defined mediolateral, anterioposterior, and dorsoventral coordinates within the cerebral cortex. Glioblastoma CSC from 4 patients and a glioblastoma nonstem-cell line were then implanted by using the same coordinates for evaluation of tumor location, growth rate, and morphologic and histologic features. Dye injections into one of the defined locations resulted in dye dissemination throughout the ventricles, whereas tumor cell implantation at the same location resulted in a much higher percentage of small multifocal ventricular tumors than did the other 3 locations tested. Ventricular tumors were associated with a lower tumor growth rate, as measured by in vivo bioluminescence imaging, and decreased survival in 4 of 5 cell lines. In addition, tissue oxygenation, vasculature, and the expression of astrocytic markers were altered in ventricular tumors compared with nonventricular tumors. Based on this information, we identified an optimal implantation location that avoided the ventricles and favored cortical tumor growth. To assess the effects of stress from oral drug administration, mice that underwent daily gavage were compared with stress-positive and -negative control groups. Oral gavage procedures did not significantly affect the survival of the implanted mice or physiologic measurements of stress. Our findings document the importance of optimization of the implantation site for preclinical mouse models of glioblastoma.

Optimization of Glioblastoma Mouse Orthotopic Xenograft Models for Translational Research

PubMed Central

Irtenkauf, Susan M; Sobiechowski, Susan; Hasselbach, Laura A; Nelson, Kevin K; Transou, Andrea D; Carlton, Enoch T; Mikkelsen, Tom; deCarvalho, Ana C

2017-01-01

Glioblastoma is an aggressive primary brain tumor predominantly localized to the cerebral cortex. We developed a panel of patient-derived mouse orthotopic xenografts (PDOX) for preclinical drug studies by implanting cancer stem cells (CSC) cultured from fresh surgical specimens intracranially into 8-wk-old female athymic nude mice. Here we optimize the glioblastoma PDOX model by assessing the effect of implantation location on tumor growth, survival, and histologic characteristics. To trace the distribution of intracranial injections, toluidine blue dye was injected at 4 locations with defined mediolateral, anterioposterior, and dorsoventral coordinates within the cerebral cortex. Glioblastoma CSC from 4 patients and a glioblastoma nonstem-cell line were then implanted by using the same coordinates for evaluation of tumor location, growth rate, and morphologic and histologic features. Dye injections into one of the defined locations resulted in dye dissemination throughout the ventricles, whereas tumor cell implantation at the same location resulted in a much higher percentage of small multifocal ventricular tumors than did the other 3 locations tested. Ventricular tumors were associated with a lower tumor growth rate, as measured by in vivo bioluminescence imaging, and decreased survival in 4 of 5 cell lines. In addition, tissue oxygenation, vasculature, and the expression of astrocytic markers were altered in ventricular tumors compared with nonventricular tumors. Based on this information, we identified an optimal implantation location that avoided the ventricles and favored cortical tumor growth. To assess the effects of stress from oral drug administration, mice that underwent daily gavage were compared with stress-positive and ‑negative control groups. Oral gavage procedures did not significantly affect the survival of the implanted mice or physiologic measurements of stress. Our findings document the importance of optimization of the implantation site for preclinical mouse models of glioblastoma. PMID:28830577

Sub-1min separation in sequential injection chromatography for determination of synthetic water-soluble dyes in pharmaceutical formulation.

PubMed

Davletbaeva, Polina; Chocholouš, Petr; Bulatov, Andrey; Šatínský, Dalibor; Solich, Petr

2017-09-05

Sequential Injection Chromatography (SIC) evolved from fast and automated non-separation Sequential Injection Analysis (SIA) into chromatographic separation method for multi-element analysis. However, the speed of the measurement (sample throughput) is due to chromatography significantly reduced. In this paper, a sub-1min separation using medium polar cyano monolithic column (5mm×4.6mm) resulted in fast and green separation with sample throughput comparable with non-separation flow methods The separation of three synthetic water-soluble dyes (sunset yellow FCF, carmoisine and green S) was in a gradient elution mode (0.02% ammonium acetate, pH 6.7 - water) with flow rate of 3.0mLmin -1 corresponding with sample throughput of 30h -1 . Spectrophotometric detection wavelengths were set to 480, 516 and 630nm and 10Hz data collection rate. The performance of the separation was described and discussed (peak capacities 3.48-7.67, peak symmetries 1.72-1.84 and resolutions 1.42-1.88). The method was represented by validation parameters: LODs of 0.15-0.35mgL -1 , LOQs of 0.50-1.25mgL -1 , calibration ranges 0.50-150.00mgL -1 (r>0.998) and repeatability at 10.0mgL -1 of RSD≤0.98% (n=6). The method was used for determination of the dyes in "forest berries" colored pharmaceutical cough-cold formulation. The sample matrix - pharmaceuticals and excipients were not interfering with vis determination because of no retention in the separation column and colorless nature. The results proved the concept of fast and green chromatography approach using very short medium polar monolithic column in SIC. Copyright © 2017 Elsevier B.V. All rights reserved.

Transport of polymer stabilized nano-scale zero-valent iron in porous media

NASA Astrophysics Data System (ADS)

Mondal, Pulin K.; Furbacher, Paul D.; Cui, Ziteng; Krol, Magdalena M.; Sleep, Brent E.

2018-05-01

This study presents a set of laboratory-scale transport experiments and numerical simulations evaluating carboxymethyl cellulose (CMC) polymer stabilized nano-scale zero-valent iron (nZVI) transport. The experiments, performed in a glass-walled two-dimensional (2D) porous medium system, were conducted to identify the effects of water specific discharge and CMC concentration on nZVI transport and to produce data for model validation. The transport and movement of a tracer lissamine green B® (LGB) dye, CMC, and CMC-nZVI were evaluated through analysis of the breakthrough curves (BTCs) at the outlets, the time-lapsed images of the plume, and retained nZVI in the sandbox. The CMC mass recovery was > 95% when injected alone and about 65% when the CMC-nZVI mixture was used. However, the mean residence time of CMC was significantly higher than that of LGB. Of significance for field implementation, viscous fingering was observed in water displacement of previously injected CMC and CMC-nZVI. The mass recovery of nZVI was lower (< 50%) than CMC recovery due to attachment onto sand grain surfaces. Consecutive CMC-nZVI injections showed higher nZVI recovery in the second injection, a factor to be considered in field trials with successive CMC-nZVI injections. Transport of LGB, CMC, and nZVI were modeled using a flow and transport model considering LGB and CMC as solutes, and nZVI as a colloid, with variable solution viscosity due to changes in CMC concentrations. The simulation results matched the experimental observations and provided estimates of transport parameters, including attachment efficiency, that can be used to predict CMC stabilized nZVI transport in similar porous media, although the extent of viscous fingering may be underpredicted. The experimental and simulation results indicated that increasing specific discharge had a greater effect on decreasing CMC-nZVI attachment efficiency (corresponding to greater possible travel distances in the field) than increasing CMC concentration.

Response surface methodological approach for the decolorization of simulated dye effluent using Aspergillus fumigatus fresenius.

PubMed

Sharma, Praveen; Singh, Lakhvinder; Dilbaghi, Neeraj

2009-01-30

The aim of our research was to study, effect of temperature, pH and initial dye concentration on decolorization of diazo dye Acid Red 151 (AR 151) from simulated dye solution using a fungal isolate Aspergillus fumigatus fresenius have been investigated. The central composite design matrix and response surface methodology (RSM) have been applied to design the experiments to evaluate the interactive effects of three most important operating variables: temperature (25-35 degrees C), pH (4.0-7.0), and initial dye concentration (100-200 mg/L) on the biodegradation of AR 151. The total 20 experiments were conducted in the present study towards the construction of a quadratic model. Very high regression coefficient between the variables and the response (R(2)=0.9934) indicated excellent evaluation of experimental data by second-order polynomial regression model. The RSM indicated that initial dye concentration of 150 mg/L, pH 5.5 and a temperature of 30 degrees C were optimal for maximum % decolorization of AR 151 in simulated dye solution, and 84.8% decolorization of AR 151 was observed at optimum growth conditions.

Adsorption Properties of p -Methyl Red Monomeric-to-Pentameric Dye Aggregates on Anatase (101) Titania Surfaces: First-Principles Calculations of Dye/TiO 2 Photoanode Interfaces for Dye-Sensitized Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lei; Cole, Jacqueline M.

2014-08-29

The optical and electronic properties of dye aggregates of p-methyl red on a TiO2 anatase (101) surface were modeled as a function of aggregation order (monomer to pentameric dye) via first principles calculations. A progressive red-shifting and intensity increase toward the visible region in UV/vis absorption spectra is observed from monomeric-to-tetrameric dyes, with each molecule in a given aggregate binding to one of the four possible TiO2 (101) adsorption sites. The pentamer exhibits a blue-shifted peak wave- length in the UV/vis absorption spectra and less absorption intensity in the visible region in comparison; a corresponding manifestation of H-aggregation occurs sincemore » one of these five molecules cannot occupy an adsorption site. This finding is consistent with experiment. Calculated density of states (DOS) and partial DOS spectra reveal similar dye…TiO2 nanocomposite conduction band characteristics but different valence band features. Associated molecular orbital distributions reveal dye-to-TiO2 interfacial charge transfer in all five differing aggregate orders; meanwhile, the level of intramolecular charge transfer in the dye becomes progressively localized around its azo- and electron-donating groups, up to the tetrameric dye/TiO2 species. Dye adsorption energies and dye coverage levels are calculated and compared with experiment. Overall, the findings of this case study serve to aid the molecular design of azo dyes towards better performing DSSC devices wherein they are incorporated. In addition, they provide a helpful example reference for understanding the effects of dye aggregation on the adsorbate…TiO2 interfacial optical and electronic properties.« less

Combining Laser Ablation/Liquid Phase Collection Surface Sampling and High-Performance Liquid Chromatography Electrospray Ionization Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ovchinnikova, Olga S; Kertesz, Vilmos; Van Berkel, Gary J

This paper describes the coupling of ambient pressure transmission geometry laser ablation with a liquid phase sample collection method for surface sampling and ionization with subsequent mass spectral analysis. A commercially available autosampler was adapted to produce a liquid droplet at the end of the syringe injection needle while in close proximity to the surface to collect the sample plume produced by laser ablation. The sample collection was followed by either flow injection or a high performance liquid chromatography (HPLC) separation of the extracted components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the analytical utility of thismore » coupling, thin films of a commercial ink sample containing rhodamine 6G and of mixed isobaric rhodamine B and 6G dyes on glass microscope slides were analyzed. The flow injection and HPLC/ESI-MS analysis revealed successful laser ablation, capture and, with HPLC, the separation of the two compounds. The ablated circular area was about 70 m in diameter for these experiments. The spatial sampling resolution afforded by the laser ablation, as well as the ability to use sample processing methods like HPLC between the sample collection and ionization steps, makes this combined surface sampling/ionization technique a highly versatile analytical tool.« less

Hydrophobic fluorescent probes introduce artifacts into single molecule tracking experiments due to non-specific binding.

PubMed

Zanetti-Domingues, Laura C; Tynan, Christopher J; Rolfe, Daniel J; Clarke, David T; Martin-Fernandez, Marisa

2013-01-01

Single-molecule techniques are powerful tools to investigate the structure and dynamics of macromolecular complexes; however, data quality can suffer because of weak specific signal, background noise and dye bleaching and blinking. It is less well-known, but equally important, that non-specific binding of probe to substrates results in a large number of immobile fluorescent molecules, introducing significant artifacts in live cell experiments. Following from our previous work in which we investigated glass coating substrates and demonstrated that the main contribution to this non-specific probe adhesion comes from the dye, we carried out a systematic investigation of how different dye chemistries influence the behaviour of spectrally similar fluorescent probes. Single-molecule brightness, bleaching and probe mobility on the surface of live breast cancer cells cultured on a non-adhesive substrate were assessed for anti-EGFR affibody conjugates with 14 different dyes from 5 different manufacturers, belonging to 3 spectrally homogeneous bands (491 nm, 561 nm and 638 nm laser lines excitation). Our results indicate that, as well as influencing their photophysical properties, dye chemistry has a strong influence on the propensity of dye-protein conjugates to adhere non-specifically to the substrate. In particular, hydrophobicity has a strong influence on interactions with the substrate, with hydrophobic dyes showing much greater levels of binding. Crucially, high levels of non-specific substrate binding result in calculated diffusion coefficients significantly lower than the true values. We conclude that the physic-chemical properties of the dyes should be considered carefully when planning single-molecule experiments. Favourable dye characteristics such as photostability and brightness can be offset by the propensity of a conjugate for non-specific adhesion.

Hydrophobic Fluorescent Probes Introduce Artifacts into Single Molecule Tracking Experiments Due to Non-Specific Binding

PubMed Central

Rolfe, Daniel J.; Clarke, David T.; Martin-Fernandez, Marisa

2013-01-01

Single-molecule techniques are powerful tools to investigate the structure and dynamics of macromolecular complexes; however, data quality can suffer because of weak specific signal, background noise and dye bleaching and blinking. It is less well-known, but equally important, that non-specific binding of probe to substrates results in a large number of immobile fluorescent molecules, introducing significant artifacts in live cell experiments. Following from our previous work in which we investigated glass coating substrates and demonstrated that the main contribution to this non-specific probe adhesion comes from the dye, we carried out a systematic investigation of how different dye chemistries influence the behaviour of spectrally similar fluorescent probes. Single-molecule brightness, bleaching and probe mobility on the surface of live breast cancer cells cultured on a non-adhesive substrate were assessed for anti-EGFR affibody conjugates with 14 different dyes from 5 different manufacturers, belonging to 3 spectrally homogeneous bands (491 nm, 561 nm and 638 nm laser lines excitation). Our results indicate that, as well as influencing their photophysical properties, dye chemistry has a strong influence on the propensity of dye-protein conjugates to adhere non-specifically to the substrate. In particular, hydrophobicity has a strong influence on interactions with the substrate, with hydrophobic dyes showing much greater levels of binding. Crucially, high levels of non-specific substrate binding result in calculated diffusion coefficients significantly lower than the true values. We conclude that the physic-chemical properties of the dyes should be considered carefully when planning single-molecule experiments. Favourable dye characteristics such as photostability and brightness can be offset by the propensity of a conjugate for non-specific adhesion. PMID:24066121

Probing the Mechanisms of an Air Amplifier using a LTQ-FT-ICR-MS and Fluorescence Spectroscopy

PubMed Central

Dixon, R. Brent; Muddiman, David C.; Hawkridge, Adam M.; Fedorov, A. G.

2008-01-01

We report the first quantitative assessment of electrosprayed droplet/ion focusing enabled by the use of a voltage-assisted air amplifier between an electrospray ionization emitter and a hybrid linear ion trap Fourier transform ion cyclotron resonance mass spectrometer (ESI-LTQ-FT-ICR-MS). A solution of fluorescent dye was electrosprayed with a stainless steel mesh screen placed in front of the MS inlet capillary acting as a gas-permeable imaging plate for fluorescence spectroscopy. Without use of the air amplifier no detectable FT-ICR signal was observed, as well as no detectable fluorescence on the screen upon imaging using a fluorescence scanner. When the air amplifier was turned ON while electrospraying the fluorescent dye, FT-ICR mass spectra with high signal to noise ratio were obtained with an average ion injection time of 21 milliseconds for an AGC target value of 5 × 105. Imaging of the screen using a fluorescence scanner produced a distinct spot of cross-sectional area ~33.5 mm2 in front of the MS inlet capillary. These experimental results provide direct evidence of aerodynamic focusing of electrosprayed droplets/ions enabled by an air amplifier, resulting in improved electrospray droplet/ion capture efficiency and reduced ion injection time. A second set of experiments was carried out to explore whether the air amplifier assists in desolvation. By electrospraying a mix of quaternary amines, ratios of increasingly hydrophobic molecules were obtained. Observation of the solvophobic effect associated with electrospray ionization resulted in a higher abundance of the hydrophobic molecule. This bias was eliminated when the air amplifier was turned ON and a response indicative of the respective component concentrations of the molecules in the bulk solution was observed. PMID:17855111

Charge Transfer Enhancement in the D-π-A Type Porphyrin Dyes: A Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) Study.

PubMed

Kang, Guo-Jun; Song, Chao; Ren, Xue-Feng

2016-11-25

The electronic geometries and optical properties of two D-π-A type zinc porphyrin dyes (NCH₃-YD2 and TPhe-YD) were systematically investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) to reveal the origin of significantly altered charge transfer enhancement by changing the electron donor of the famous porphyrin-based sensitizer YD2-o-C8. The molecular geometries and photophysical properties of dyes before and after binding to the TiO₂ cluster were fully investigated. From the analyses of natural bond orbital (NBO), extended charge decomposition analysis (ECDA), and electron density variations (Δρ) between the excited state and ground state, it was found that the introduction of N(CH₃)₂ and 1,1,2-triphenylethene groups enhanced the intramolecular charge-transfer (ICT) character compared to YD2-o-C8. The absorption wavelength and transition possess character were significantly influenced by N(CH₃)₂ and 1,1,2-triphenylethene groups. NCH₃-YD2 with N(CH₃)₂ groups in the donor part is an effective way to improve the interactions between the dyes and TiO₂ surface, light having efficiency (LHE), and free energy change (ΔG inject ), which is expected to be an efficient dye for use in dye-sensitized solar cells (DSSCs).

Distribution of radiodense contrast medium after perineural injection of the palmar and palmar metacarpal nerves (low 4-point nerve block): an in vivo and ex vivo study in horses.

PubMed

Nagy, A; Bodò, G; Dyson, S J; Compostella, F; Barr, A R S

2010-09-01

Evidence-based information is limited on distribution of local anaesthetic solution following perineural analgesia of the palmar (Pa) and palmar metacarpal (PaM) nerves in the distal aspect of the metacarpal (Mc) region ('low 4-point nerve block'). To demonstrate the potential distribution of local anaesthetic solution after a low 4-point nerve block using a radiographic contrast model. A radiodense contrast medium was injected subcutaneously over the medial or the lateral Pa nerve at the junction of the proximal three-quarters and distal quarter of the Mc region (Pa injection) and over the ipsilateral PaM nerve immediately distal to the distal aspect of the second or fourth Mc bones (PaM injection) in both forelimbs of 10 mature horses free from lameness. Radiographs were obtained 0, 10 and 20 min after injection and analysed subjectively and objectively. Methylene blue and a radiodense contrast medium were injected in 20 cadaver limbs using the same techniques. Radiographs were obtained and the limbs dissected. After 31/40 (77.5%) Pa injections, the pattern of the contrast medium suggested distribution in the neurovascular bundle. There was significant proximal diffusion with time, but the main contrast medium patch never progressed proximal to the mid-Mc region. The radiological appearance of 2 limbs suggested that contrast medium was present in the digital flexor tendon sheath (DFTS). After PaM injections, the contrast medium was distributed diffusely around the injection site in the majority of the limbs. In cadaver limbs, after Pa injections, the contrast medium and the dye were distributed in the neurovascular bundle in 8/20 (40%) limbs and in the DFTS in 6/20 (30%) of limbs. After PaM injections, the contrast and dye were distributed diffusely around the injection site in 9/20 (45%) limbs and showed diffuse and tubular distribution in 11/20 (55%) limbs. Proximal diffusion of local anaesthetic solution after a low 4-point nerve block is unlikely to be responsible for decreasing lameness caused by pain in the proximal Mc region. The DFTS may be penetrated inadvertently when performing a low 4-point nerve block.

Photocurrent enhanced by singlet fission in a dye-sensitized solar cell.

PubMed

Schrauben, Joel N; Zhao, Yixin; Mercado, Candy; Dron, Paul I; Ryerson, Joseph L; Michl, Josef; Zhu, Kai; Johnson, Justin C

2015-02-04

Investigations of singlet fission have accelerated recently because of its potential utility in solar photoconversion, although only a few reports definitively identify the role of singlet fission in a complete solar cell. Evidence of the influence of singlet fission in a dye-sensitized solar cell using 1,3-diphenylisobenzofuran (DPIBF, 1) as the sensitizer is reported here. Self-assembly of the blue-absorbing 1 with co-adsorbed oxidation products on mesoporous TiO2 yields a cell with a peak internal quantum efficiency of ∼70% and a power conversion efficiency of ∼1.1%. Introducing a ZrO2 spacer layer of thickness varying from 2 to 20 Å modulates the short-circuit photocurrent such that it is initially reduced as thickness increases but 1 with 10-15 Å of added ZrO2. This rise can be explained as being due to a reduced rate of injection of electrons from the S1 state of 1 such that singlet fission, known to occur with a 30 ps time constant in polycrystalline films, has the opportunity to proceed efficiently and produce two T1 states per absorbed photon that can subsequently inject electrons into TiO2. Transient spectroscopy and kinetic simulations confirm this novel mode of dye-sensitized solar cell operation and its potential utility for enhanced solar photoconversion.

Posterior hyaloid detachment and internal limiting membrane peeling assisted by anthocyanins from acai fruit (Euterpe oleracea) and 10 other natural vital dyes: experimental study in cadaveric eyes.

PubMed

Chen, Jane; Ferreira, Magno Antonio; Farah, Michel Eid; de Carvalho, André Maia; Alves Ferreira, Raquel Eustaquio; de Moraes Filho, Milton Nunes; Souza Lima-Filho, Acácio Alves; Lago, João Henrique G; Sartorelli, Patricia; Rodrigues, Eduardo Buchele; Ferreira, Eber; Peris, Cristiane; Maia, Maurício

2013-01-01

The purpose of this study was to determine whether natural dyes facilitate posterior hyaloid detachment (posterior vitreous detachment [PVD]) and retinal internal limiting membrane (ILM) peeling in human eyes. Open-sky vitrectomy with posterior hyaloid and ILM removal was performed in 86 human cadaveric eyes. After core vitrectomy, 11 different dyes were injected into the vitreous cavity to aid hyaloid detachment and ILM removal. The dyes were allowed to settle on the macula for 5 minutes after PVD and were removed by mechanical aspiration. Intraocular forceps were used for ILM peeling, which was confirmed by light microscopy of the peeled tissue. Acai fruit (Euterpe oleracea) extract and 10 additional dyes from plants or animal sources were tested: pomegranate (Punica granatum), logwood (Haematoxylum campechianum), chlorophyll extract from alfalfa (Medicago sativa), cochineal (Dactylopius coccus), hibiscus (Hibiscus rosa-sinensis), indigo (Indigofera tinctoria), paprika (Capiscum annuum), turmeric (Curcuma longa), old fustic (Maclura tinctoria), and grape (Vitis vinifera). The dyes facilitated PVD and ILM peeling. Acai fruit (E. oleracea) extract, logwood (H. campechianum), cochineal (D. coccus), and old fustic (M. tinctoria) facilitated PVD in all cases; dye-assisted PVD was compared with triamcinolone-assisted PVD performed previously in a comparative model. Acai fruit (E. oleracea) extract, cochineal (D. coccus), and chlorophyll extract from alfalfa (M. sativa) showed the best capability for ILM staining; dye-assisted ILM removal was compared with the ILM peeling guided by indocyanine green staining performed previously in a comparative model. Light microscopy confirmed the ILM removal in all cases. Anthocyanin dye of the acai fruit (E. oleracea) and the dyes from cochineal (D. coccus) and chlorophyll extract from alfalfa (M. sativa) resulted in the best capability for posterior hyaloid and ILM staining in human cadaveric eyes and may be a useful tool for vitreoretinal surgery.

Decolorization of Mordant red 73 azo dye in water using H2O2/UV and photo-Fenton treatment.

PubMed

Elmorsi, Taha M; Riyad, Yasser M; Mohamed, Zeinhom H; Abd El Bary, Hassan M H

2010-02-15

Decolorization of the Mordant red 73 (MR73) azo dye in water was investigated in laboratory-scale experiments using UV/H(2)O(2) and photo-Fenton treatments. Photodegradation experiments were carried out in a stirred batch photoreactor equipped with a low-pressure mercury lamp as UV source at 254 nm. The effect of operating parameters such as pH, [H(2)O(2)](,) [dye] and the presence of inorganic salts (NaNO(3), NaCl and Na(2)CO(3)) were also investigated. The results indicated that complete dye decolorization was obtained in less than 60 min under optimum conditions. Furthermore, results showed that dye degradation was dependent upon pH, [H(2)O(2)] and initial dye concentration. The presence of chloride ion led to large decreases in the photodegradation rate of MR73 while both nitrate and carbonate ions have a slight effect. The photo-Fenton treatment, in the presence of Fe powder as a source of Fe(2+) ions, was highly efficient and resulted in 99% decolorization of the dye in 15 min. Mineralization of MR73 dye was investigated by determining chemical oxygen demand (COD). In a 3h photoperiod "65%" of the dye was mineralized by the H(2)O(2)/UV process, while the photo-Fenton treatment was more efficient producing 85% mineralization over the same 3-h period.

Observations of Cross-Surf-zone / Inner-shelf Dye Exchange from Aerial Hyperspectral and in Situ Data.

NASA Astrophysics Data System (ADS)

Grimes, D. J.; Giddings, S. N.; Kumar, N.; Pawlak, G. R.; Feddersen, F.

2016-12-01

Understanding the cross-shelf exchange of nearshore sourced tracers across the surfzone and onto the stratified inner-shelf is critical to be able to predict the evolution of pollution events, HAB, and larval transport, which will enable policy and mitigation efforts. The CSIDE (Cross Surfzone / Inner-shelf Dye Exchange) experiment (Sept & Oct 2015) provides observations to quantify dye tracer exchange across the surfzone/inner-shelf region with 3 dye release experiments. Shoreline released dye and temperature is tracked for 48 hrs and 20 km using aerial hyperspectral and IR imagery, in situ near-shoreline fluorometers, moored wire-walkers, AUV, and boat based towed observations. Here, we focus on the 3rd release, where dye was pumped into the mouth of the Tijuana River / Estuary during an ebb tide with low river discharge. The dye field was transported alongshore in a large coherent patch extending 1 km from shore. The plume persisted overnight with weak dilution and its center of mass was observed to move 3+ km north over 18 hrs. Aerial hyperspectral and in situ observations are analyzed to examine the horizontal and vertical dye distribution. In particular, we will explore the extent to which the stratified inner-shelf is a "material barrier," whether an observed surfzone dye and temperature correlation is maintained on the stratified inner-shelf, at what time- and length-scales, and the processes influencing this relationship.

Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source

PubMed Central

Gioux, Sylvain; Lomnes, Stephen J.; Choi, Hak Soo; Frangioni, John V.

2010-01-01

Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequencies up to 35 MHz. Lifetime imaging of indocyanine green (ICG), IRDye 800-CW, and 3,3′-diethylthiatricarbocyanine iodide (DTTCI) was performed over a large field of view (10 cm by 7.5 cm) using the LED light source. For comparison, a laser diode light source was employed as a gold standard. Experiments were performed both on the bench by diluting the fluorescent dyes in various chemical environments in Eppendorf tubes, and in vivo by injecting the fluorescent dyes mixed in Matrigel subcutaneously into CD-1 mice. Last, measured fluorescence lifetimes obtained using the LED and the laser diode sources were compared with those obtained using a state-of-the-art time-domain imaging system and with those previously described in the literature. On average, lifetime values obtained using the LED and the laser diode light sources were consistent, exhibiting a mean difference of 3% from the expected values and a coefficient of variation of 12%. Taken together, our study offers an alternative to laser diodes for clinical translation of FLi and explores the use of relatively low frequency modulation for in vivo imaging. PMID:20459250

Tracers for fluorescence-guided surgery: how elongation of the polymethine chain in cyanine dyes alters the pharmacokinetics of a (bimodal) c[RGDyK] tracer.

PubMed

Buckle, Tessa; van Willigen, Danny M; Spa, Silvia J; Hensbergen, Albertus W; van der Wal, Steffen; de Korne, Clarize M; Welling, Mick M; van der Poel, Henk G; Hardwick, James C H; van Leeuwen, Fijs W B

2018-02-15

Objectives: The potential of (receptor-mediated) fluorescence-based image-guided surgery tracers is generally linked to the near-infrared emission profile and good manufacturing production (GMP) availability of fluorescent dyes. Surprisingly, little is known about the critical interaction between the structural composition of the dye and the pharmacokinetics of the tracers. In this study, a bimodal/hybrid tracer design was used to systematically and quantitatively evaluate the influence of elongation of the polymethine chain in a fluorescent cyanine (Cy) dye on the imaging potential of a targeted (RGD-based) tracer. Methods: As model system, the integrin marker ανβ3 was targeted using c[RGDyK] vectors functionalized with a ( 111 In-)DTPA chelate and a fluorescent dye (Cy3-(SO3)Methyl-COOH (λem 580nm), Cy5-(SO3)Methyl-COOH (λem 680nm), or Cy7-(SO3)Methyl-COOH (λem 780nm)). Tracers were analyzed for differences in (photo-) physical properties, serum protein binding, chemical/optical stability and signal penetration through tissue. Receptor affinities (KD) were evaluated using saturation and competition experiments. In vivo biodistribution (SPECT imaging and percentage injected dose per gram of tissue (%ID/g)) was assessed in tumor-bearing mice and complimented with in- and ex vivo fluorescence images obtained using a clinical grade multispectral fluorescence laparoscope. Results: Two carbon-atom-step variations in the polymethine chain of the fluorescent Cy-dyes were shown to significantly influence the chemical and photophysical characteristics e.g. stability, brightness and tissue penetration of the hybrid RGD-tracers. Herein DTPA-Cy5-(SO3)Methyl-COOH-c[RGDyK] systematically outperformed its Cy3- and Cy7- derivatives. Radioactivity-based evaluation of in vivo tracer pharmacokinetics yielded the lowest non-specific uptake and highest tumor-to-background ratio (T/B) for DTPA-Cy5-(SO3)Methyl-COOH-c[RGDyK] (13.2 ± 1.7), with the Cy3- and Cy7- analogs trailing at a respective T/B of 5.7 ± 0.7 and 4.7 ± 0.7. Fluorescence-based assessment of the tumor visibility revealed a similar trend. Conclusion: These findings underline that variations in the polymethine chain lengths of Cy dyes have a profound influence on the photophysical properties, stability and in vivo targeting capabilities of fluorescent imaging tracers. In a direct comparison the intermediate length dye (Cy5) yielded a superior c[RGDyK] -tracer compared to the shorter (Cy3-) and longer (Cy7-) analogs. Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Theoretical Study of Electron Transfer Properties of Squaraine Dyes for Dye Sensitized Solar Cell

NASA Astrophysics Data System (ADS)

Juwita, Ratna; Tsai, Hui-Hsu Gavin

2018-01-01

The environmental issues and high cost of Ru create many scientists to explore cheaper and safer sensitizer as alternative for dye sensitized solar cells (DSCs). Dyes play an important role in solar energy conversion efficiency. The squaraine (SQ) dyes has good spectral match with the solar spectra, therefore, SQ dyes have great potential for the applications in DSCs. SQ01_CA is an unsymmetrical SQ dye, reported by Grätzel and colleagues in 2007, featuring a D-π-spacer-A framework and has a carboxylic acid anchoring group. The electron donating ability of indolium in SQ01_CA and SQ01_CAA dyes is relatively weak, better performance may be achieved by introducing an additional donor moiety into indolium [1]. In this study, we investigate six unsymmetrical SQ dyes adsorbed on a (TiO2)38 cluster [2] using density functional theory (DFT) and time-dependent DFT to study electron transfer properties of squaraine dyes on their photophysical. SQ01_CA, WH-SQ01_CA, and WH-SQ02_CA use a carboxylic acid group as its electron acceptor. Furthermore, SQ01_CAA, WH-SQ01_CAA, and WH-SQ02_CAA use a cyanoacrylic acid group as its electron acceptor. WH-SQ01_CA and WH-SQ01_CAA have an alkyl, while WH-SQ02_CA and WH-SQ02_CAA have alkoxyl substituted diarylamines to the indolium donor of sensitizer SQ01_CA. Our calculations show with additional diarylamines in donor tail of WH-SQ02_CAA, the SQ dyes have red-shifted absorption and have slightly larger probability of electron density transferred to TiO2 moiety. Furthermore, an additional -CN group as electron a withdrawing group in the acceptor exhibits red-shifted absorption and enhances the electron density transferred to TiO2 and anchoring moiety after photo-excitation. The tendency of calculated probabilities of electron density being delocalized into TiO2 and driving force for excited-state electron injection of these studied SQ dyes is compatible with their experimentally observed.

Infiltration in unsaturated layered fluvial deposits at Rio Bravo : photo essay and data summary.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brainard, James Robert; Glass, Robert John, Jr.

2007-08-01

An infiltration and dye transport experiment was conducted to visualize flow and transport processes in a heterogeneous, layered, sandy-gravelly fluvial deposit adjacent to Rio Bravo Boulevard in Albuquerque, NM. Water containing red dye followed by blue-green dye was ponded in a small horizontal zone ({approx}0.5 m x 0.5 m) above a vertical outcrop ({approx}4 m x 2.5 m). The red dye lagged behind the wetting front due to slight adsorption thus allowing both the wetting front and dye fronts to be observed in time at the outcrop face. After infiltration, vertical slices were excavated to the midpoint of the infiltrometermore » exposing the wetting front and dye distribution in a quasi three-dimensional manner. At small-scale, wetting front advancement was influenced by the multitude of local capillary barriers within the deposit. However at the scale of the experiment, the wetting front appeared smooth with significant lateral spreading {approx} twice that in the vertical, indicating a strong anisotropy due to the pronounced horizontal layering. The dye fronts exhibited appreciably more irregularity than the wetting front, as well as the influence of preferential flow features (a fracture) that moved the dye directly to the front, bypassing the fresh water between.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ünal, Hatice; Mete, Ersen, E-mail: emete@balikesir.edu.tr; Gunceler, Deniz

The adsorption of two different organic molecules cyanidin glucoside (C{sub 21}O{sub 11}H{sub 20}) and TA-St-CA on anatase (101) and (001) nanowires has been investigated using the standard and the range separated hybrid density functional theory calculations. The electronic structures and optical spectra of resulting dye–nanowire combined systems show distinct features for these types of photochromophores. The lowest unoccupied molecular orbital of the natural dye cyanidin glucoside is located below the conduction band of the semiconductor while, in the case of TA-St-CA, it resonates with the states inside the conduction band. The wide-bandgap anatase nanowires can be functionalized for solar cellsmore » through electron-hole generation and subsequent charge injection by these dye sensitizers. The intermolecular charge transfer character of Donor-π-Acceptor type dye TA-St-CA is substantially modified by its adsorption on TiO{sub 2} surfaces. Cyanidin glucoside exhibits relatively stronger anchoring on the nanowires through its hydroxyl groups. The atomic structures of dye–nanowire systems re-optimized with the inclusion of nonlinear solvation effects showed that the binding strengths of both dyes remain moderate even in ionic solutions.« less

Time of travel and dispersion of solutes in a 36.4-mile reach of the North Platte River downstream from Casper, Wyoming

USGS Publications Warehouse

Armentrout, G.W.; Larson, L.R.

1984-01-01

Time-of-travel and dispersion measurements made during a dye study November 7-8, 1978, are presented for a reach of the North Platte River from Casper, Wyo., to a bridge 2 miles downstream from below the Dave Johnston Power Plant. Rhodamine WT dye was injected into the river at Casper, and the resultant dye cloud was traced by sampling as it moved downstream. Samples were taken in three equal-flow sections of the river 's lateral transect at three sites, then analyzed in a fluorometer. The flow in the river was 940 cubic feet per second. The data consist of measured stream mileages and time, distance, and concentration graphs of the dye cloud. The peak concentration traveled through the reach in 24 hours, averaging 1.5 miles per hour; the leading edge took about 22 hours, averaging 1.7 miles per hour; and the trailing edge took 35 hours, averaging 1.0 mile per hour. Data from this study were compared with methods for estimating time of travel for a range of stream discharges.

An enhanced mangiferaindica for dye sensitized solar cell application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uno, U. E., E-mail: moses.emetere@covenantuniversity.edu.ng; Emetere, M. E., E-mail: uno-essang@yahoo.co.uk; Fadipe, L. A.

Titanium dioxide (T1O2) is preferred to Zinc oxide as mesoporous oxide layer because it raised the efficiency of DSSCs from 1% to 7%. The chemistry of the process however seem rigorous to allow the light induced electron injection from the adsorbed dye into the nanocrystallites i.e. which renders the TiO{sub 2} conductive. The DSSC fabricated consist of 2.25 cm{sup 2} active area of titanium dioxide coated on FTO glass (fluorine tin oxide) immersed in ethanol solution of natural dye extracted as an anode (electrode) and counter electrode. These two electrodes were coupled together and the space between them was filledmore » with the Iodolyte AN-50 as solid electrolyte or redox mediator. The photo electrochemical parameters of the dye extracted (Mango fruit Peel) from the results obtained are short circuit current (Isc)= 1.22×10{sup −2}, current density (Jsc)=4.07×10{sup −2}, open circuit voltage (voc) =0.53V, fill factor (FF) of 0.16 and the overall conversion efficiency (Eff) =0.345%.« less

Anaphylaxis to dyes during the perioperative period: reports of 14 clinical cases.

PubMed

Mertes, Paul Michel; Malinovsky, Jean Marc; Mouton-Faivre, Claudie; Bonnet-Boyer, Marie Caroline; Benhaijoub, Abdelhaouad; Lavaud, François; Valfrey, Jocelyne; O'Brien, James; Pirat, Philippe; Lalourcey, Laurent; Demoly, Pascal

2008-08-01

Vital dyes are widely used for lymphatic mapping and sentinel lymph node biopsy in patients with malignant tumors, and reports of anaphylactic reactions are becoming more frequent. Our aims were to describe specific clinical features of hypersensitivity reactions to Patent Blue (Guerbet, Roissy, France), results of the allergy workup, and their consequences for patient management. We report a series of 14 clinical cases of dye-induced anaphylaxis recorded between 2004 and 2006 in 4 member centers of a network of French allergoanesthesia outpatient clinics. Reactions appeared to be relatively severe (6/14 grade III reactions). An average 30 +/- 6-minute delay was observed between dye injection and symptom onset. In 9 (65%) patients reactions were sustained for several hours, requiring prolonged continuous epinephrine infusion and transfer to an intensive care unit. Prick test results were positive in 8 patients. In 5 patients prick test results were negative, whereas intradermal test results were positive. Anesthesiologists and allergologists must be aware of this specific risk and of the clinical characteristics of these reactions, which are usually delayed and long lasting.

Microscopic dynamics research on the "mature" process of dye-sensitized solar cells after injection of highly concentrated electrolyte.

PubMed

Liang, Zhongguan; Liu, Weiqing; Chen, Jun; Hu, Linhua; Dai, Songyuan

2015-01-21

After injection of electrolyte, the internal three-dimensional solid-liquid penetration system of dye-sensitized solar cells (DSCs) can take a period of time to reach "mature" state. This paper studies the changes of microscopic processes of DSCs including TiO2 energy-level movement, localized state distribution, charge accumulation, electron transport, and recombination dynamics, from the beginning of electrolyte injection to the time of reached mature state. The results show that the microscopic dynamics process of DSCs exhibited a time-dependent behavior and achieved maturity ∼12 h after injecting the electrolyte into DSCs. Within 0-12 h, several results were observed: (1) the conduction band edge of TiO2 moved slightly toward negative potential direction; (2) the localized states in the band gap of TiO2 was reduced according to the same distribution law; (3) the transport resistance in TiO2 film increased, and electron transport time was prolonged as the time of maturity went on, which indicated that the electron transport process is impeded gradually; (4) the recombination resistance at the TiO2/electrolyte (EL) interface increases, and electron lifetime gradually extends, therefore, the recombination process is continuously suppressed. Furthermore, results suggest that the parameters of EL/Pt-transparent conductive oxide (TCO) interface including the interfacial capacitance, electron-transfer resistance, and transfer time constant would change with time of maturity, indicating that the EL/Pt-TCO interface is a potential factor affecting the mature process of DSCs.

Interstitial laser photochemotherapy with new anthrapyrazole drugs for the treatment of xenograft tumors.

PubMed

Paiva, M B; Saxton, R E; Letts, G A; Chung, P S; Soudant, J; Vanderwerf, Q; Castro, D J

1995-10-01

Photodynamic therapy (PDT) with lasers and new dyes has gained popularity in recent years as a minimally invasive technique with high tumoricidal effects in vitro and in some cancer patients. However, because new laser dyes are not FDA approved at present, the clinical evaluation of PDT may be years away. During the past 6 years we have used laser alone for photothermal ablation in both preclinical studies and in a large number of patients with an observed 60% tumor response rate. The 40% treatment failure led us to explore the possibility of combined therapy with lasers and standard chemotherapeutic drugs. We have recently tested a promising preclinical alternative using implantation of a bare 600-microns KTP 532 laser fiberoptic in multiple tumor sites 30 min after intratumor injection of the anthrapyrazole DUP-941. As a control, this drug was injected in 3 sites of P3 human squamous cell tumor transplants in nude mice, which led to tumor stasis without regression. Similar 400-600 mm3 tumors exposed to laser illumination alone (0.8 W for 5 sec) at multiple sites resulted in tumor regrowth after 10 weeks in 80% of the animals. However, combining interstitial laser illumination with intratumor DUP-941 injections led to complete tumor regression in 85% of the mice. We propose that intratumor drug injection followed by interstitial laser fiberoptic treatment represents a potentially useful new method for tumor ablation in advanced cancer patients.

Transient cerebral hypoperfusion assisted intraarterial cationic liposome delivery to brain tissue

PubMed Central

Joshi, Shailendra; Singh-Moon, Rajinder P.; Wang, Mei; Chaudhuri, Durba B.; Holcomb, Mark; Straubinger, Ninfa L.; Bruce, Jeffrey N.; Bigio, Irving J.; Straubinger, Robert M.

2014-01-01

Object Transient cerebral hypoperfusion (TCH) has empirically been used to assist intraarterial (IA) drug delivery to brain tumors. Transient (< 3 min) reduction of cerebral blood flow (CBF) occurs during many neuro- and cardiovascular interventions and has recently been used to better target IA drugs to brain tumors. In the present experiments, we assessed whether the effectiveness of IA delivery of cationic liposomes could be improved by TCH. Methods Cationic liposomes composed of 1:1 DOTAP:PC (dioleoyl-trimethylammonium-propane:phosphatidylcholine) were administered to three groups of Sprague Dawley rats. In the first group, we tested the effect of blood flow reduction on IA delivery of cationic liposomes. In the second group, we compared TCH-assisted IA liposomal delivery vs. intravenous (IV) administration of the same dose. In the third group, we assessed retention of cationic liposomes in brain four hours after TCH assisted delivery. The liposomes contained a near infrared dye, DilC18(7), whose concentration could be measured in vivo by diffuse reflectance spectroscopy. Results IA injections of cationic liposomes during TCH increased their delivery approximately four-fold compared to injections during normal blood flow. Optical pharmacokinetic measurements revealed that relative to IV injections, IA injection of cationic liposomes during TCH produced tissue concentrations that were 100-fold greater. The cationic liposomes were retained in the brain tissue four hours after a single IA injection. There was no gross impairment of neurological functions in surviving animals. Conclusions Transient reduction in CBF significantly increased IA delivery of cationic liposomes in the brain. High concentrations of liposomes could be delivered to brain tissue after IA injections with concurrent TCH while none could be detected after IV injection. IA-TCH injections were well tolerated and cationic liposomes were retained for at least 4 hours after IA administration. These results should encourage development of cationic liposomal formulations of chemotherapeutic drugs and their IA delivery during TCH. PMID:24664370

Protein labeling with red squarylium dyes for analysis by capillary electrophoresis with laser-induced fluorescence detection.

PubMed

Yan, Weiying; Sloat, Amy L; Yagi, Shigeyuki; Nakazumi, Hiroyuki; Colyer, Christa L

2006-04-01

Two new red luminescent asymmetric squarylium dyes (designated "Red-1c and Red-3") have been shown to exhibit absorbance shifts to longer wavelengths upon the addition of protein, along with a concomitant increase in fluorescence emission. Specifically, the absorbance maxima for Red-1c and Red-3 dyes are 607 and 622 nm, respectively, in the absence of HSA, and 642 and 640 nm in the presence of HSA, making the excitation of their protein complexes feasible with inexpensive and robust diode lasers. Fluorescence emission maxima, in the presence of HSA, are 656 and 644 nm for Red-1c and Red-3, respectively. Because of the inherently low fluorescence of the dyes in their free state, Red-1c and Red-3 were used as on-column labels (that is, with the dye incorporated into the separation buffer), thus eliminating the need for sample derivatization prior to injection and separation. A comparison of precolumn and on-column labeling of proteins with these squarylium dyes revealed higher efficiencies and greater sensitivities for on-column labeling, which, when conducted with a basic, high-salt content buffer, permitted baseline resolution of a mixture of five model proteins. LOD for model proteins, such as transferrin, alpha-lactalbumin, BSA, and beta-lactoglobulin A and B, labeled with these dyes and analyzed by CE with LIF detection (CE-LIF) were found to be dependent upon dye concentration and solution pH, and are as low as 5 nM for BSA. Satisfactory linear relationships between peak height (or peak area) and protein concentration were obtained by CE-LIF for this on-column labeling method with Red-3 and Red-1c.

Effect of lidocaine- and prilocaine-based topical anesthetics on the inflammatory exudates in subcutaneous tissue of rats.

PubMed

Pochapski, Márcia Thaís; Neto, José Laufer; Jassen, Jocélia Lago; Farago, Paulo Vitor; Santos, Fábio André

2012-01-01

The aim of this present study was to evaluate the irritative potential of 2 topical anesthetics used in intrapocket anesthesia for periodontal scaling/root planing when applied in subcutaneous tissue of rats. Sixty animals were divided into 4 groups: group 1, saline solution (control); group 2, poloxamer gel (thermosetting vehicle); group 3, lidocaine and prilocaine poloxamer thermosetting gel; group 4: EMLA, a lidocaine and prilocaine dermatological cream. Injections of 2% Evans blue were administrated intravenously into the lateral caudal vein. In order to analyze vascular permeability, the tested substances were injected intradermally. The rats were sacrificed 3, 6, and 9 hours after injection of the substances. The dorsal skin was dissected and removed. The vascular permeability was evaluated by the measurement of area of dye extravasation and the dye was subsequently extracted after immersion in formamide. Statistical analyses were made by ANOVA with Bonferroni's post hoc test and Pearson correlation. The 2 methods to analyze the exudative phase of the inflammatory process showed statistically significant difference among the groups and periods of evaluation (P < .05). Both methods had a significant correlation (P < .0001). Under the tested conditions, the anesthetic agents showed mild initial inflammatory response when implanted in subcutaneous connective tissue.

Effect of Lidocaine- and Prilocaine-Based Topical Anesthetics on the Inflammatory Exudates in Subcutaneous Tissue of Rats

PubMed Central

Pochapski, Márcia Thaís; Neto, José Laufer; Jassen, Jocélia Lago; Farago, Paulo Vitor; Santos, Fábio André

2012-01-01

The aim of this present study was to evaluate the irritative potential of 2 topical anesthetics used in intrapocket anesthesia for periodontal scaling/root planing when applied in subcutaneous tissue of rats. Sixty animals were divided into 4 groups: group 1, saline solution (control); group 2, poloxamer gel (thermosetting vehicle); group 3, lidocaine and prilocaine poloxamer thermosetting gel; group 4: EMLA, a lidocaine and prilocaine dermatological cream. Injections of 2% Evans blue were administrated intravenously into the lateral caudal vein. In order to analyze vascular permeability, the tested substances were injected intradermally. The rats were sacrificed 3, 6, and 9 hours after injection of the substances. The dorsal skin was dissected and removed. The vascular permeability was evaluated by the measurement of area of dye extravasation and the dye was subsequently extracted after immersion in formamide. Statistical analyses were made by ANOVA with Bonferroni's post hoc test and Pearson correlation. The 2 methods to analyze the exudative phase of the inflammatory process showed statistically significant difference among the groups and periods of evaluation (P < .05). Both methods had a significant correlation (P < .0001). Under the tested conditions, the anesthetic agents showed mild initial inflammatory response when implanted in subcutaneous connective tissue. PMID:22822991

Optimal volume of injectate for fluoroscopy-guided cervical interlaminar epidural injection in patients with neck and upper extremity pain

PubMed Central

Park, Jun Young; Kim, Doo Hwan; Lee, Kunhee; Choi, Seong-Soo; Leem, Jeong-Gil

2016-01-01

Abstract There is no study of optimal volume of contrast medium to use in cervical interlaminar epidural injections (CIEIs) for appropriate spread to target lesions. To determine optimal volume of contrast medium to use in CIEIs. We analyzed the records of 80 patients who had undergone CIEIs. Patients were divided into 3 groups according to the amount of contrast: 3, 4.5, and 6 mL. The spread of medium to the target level was analyzed. Numerical rating scale data were also analyzed. The dye had spread to a point above the target level in 15 (78.9%), 22 (84.6%), and 32 (91.4%) patients in groups 1 to 3, respectively. The dye reached both sides in 14 (73.7%), 18 (69.2%), and 23 (65.7%) patients, and reached the ventral epidural space in 15 (78.9%), 22 (84.6%), and 30 (85.7%) patients, respectively. There were no significant differences of contrast spread among the groups. There were no significant differences in the numerical rating scale scores among the groups during the 3 months. When performing CIEIs, 3 mL medication is sufficient volume for the treatment of neck and upper-extremity pain induced by lower cervical degenerative disease. PMID:27787378

Optimal volume of injectate for fluoroscopy-guided cervical interlaminar epidural injection in patients with neck and upper extremity pain.

PubMed

Park, Jun Young; Kim, Doo Hwan; Lee, Kunhee; Choi, Seong-Soo; Leem, Jeong-Gil

2016-10-01

There is no study of optimal volume of contrast medium to use in cervical interlaminar epidural injections (CIEIs) for appropriate spread to target lesions. To determine optimal volume of contrast medium to use in CIEIs. We analyzed the records of 80 patients who had undergone CIEIs. Patients were divided into 3 groups according to the amount of contrast: 3, 4.5, and 6 mL. The spread of medium to the target level was analyzed. Numerical rating scale data were also analyzed. The dye had spread to a point above the target level in 15 (78.9%), 22 (84.6%), and 32 (91.4%) patients in groups 1 to 3, respectively. The dye reached both sides in 14 (73.7%), 18 (69.2%), and 23 (65.7%) patients, and reached the ventral epidural space in 15 (78.9%), 22 (84.6%), and 30 (85.7%) patients, respectively. There were no significant differences of contrast spread among the groups. There were no significant differences in the numerical rating scale scores among the groups during the 3 months. When performing CIEIs, 3 mL medication is sufficient volume for the treatment of neck and upper-extremity pain induced by lower cervical degenerative disease.

Determination of minimum enzymatic decolorization time of reactive dye solution by spectroscopic & mathematical approach.

PubMed

Celebi, Mithat; Ozdemir, Zafer Omer; Eroglu, Emre; Altikatoglu, Melda; Guney, Ibrahim

2015-02-01

Synthetic dyes are very important for textile dyeing, paper printing, color photography and petroleum products. Traditional methods of dye removal include biodegradation, precipitation, adsorption, chemical degradation, photo degradation, and chemical coagulation. Dye decolorization with enzymatic reaction is an important issue for several research field (chemistry, environment) In this study, minimum decolorization time of Remazol Brilliant Blue R dye with Horseradish peroxidase enzyme was calculated using with mathematical equation depending on experimental data. Dye decolorization was determined by monitoring the absorbance decrease at the specific maximum wavelength for dye. All experiments were carried out with different initial dye concentrations of Remazol Brilliant Blue R at 25 degrees C constant temperature for 30 minutes. The development of the least squares estimators for a nonlinear model brings about complications not encountered in the case of the linear model. Decolorization times for completely removal of dye were calculated according to equation. It was shown that mathematical equation was conformed exponential curve for dye degradation.

Self-assembled dye-doped polymer microspheres as whispering gallery mode lasers

NASA Astrophysics Data System (ADS)

Chen, Xiaogang; Sun, Hongyi; Yang, Hongqin; Wu, Xiang; Xie, Shusen

2016-10-01

Microlasers based on high-Q whispering-gallery-mode (WGM) resonances are promising low-threshold laser sources for bio-sensing and imaging applications. In this talk, we demonstrate a cost effective approach to obtain size-controllable polymer microspheres, which can be served as good WGM microcavities. By injecting SU-8 solution into low-refractiveindex UV polymer, self-assembled spherical droplet with smooth surface can be created inside the elastic medium and then solidified by UV exposure. The size of the microspheres can be tuned from several to hundreds of microns. WGM Lasing has been achieved by optically pumping the dye-doped microspheres with ns lasers. Experimental results show that the microsphere lasers have high quality factors and low lasing thresholds. The self-assembled dye-doped polymer microspheres would provide an excellent platform for the micro-laser sources in on-chip biosensing and imaging systems.

Emission characteristics in solution-processed asymmetric white alternating current field-induced polymer electroluminescent devices

NASA Astrophysics Data System (ADS)

Chen, Yonghua; Xia, Yingdong; Smith, Gregory M.; Gu, Yu; Yang, Chuluo; Carroll, David L.

2013-01-01

In this work, the emission characteristics of a blue fluorophor poly(9, 9-dioctylfluorene) (PFO) combined with a red emitting dye: Bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate)iridium (III) [Ir(MDQ)2(acac)], are examined in two different asymmetric white alternating current field-induced polymer electroluminescent (FIPEL) device structures. The first is a top-contact device in which the triplet transfer is observed resulting in the concentration-dependence of the emission similar to the standard organic light-emitting diode (OLED) structure. The second is a bottom-contact device which, however, exhibits concentration-independence of emission. Specifically, both dye emission and polymer emission are found for the concentrations as high as 10% by weight of the dye in the emitter. We attribute this to the significant different carrier injection characteristics of the two FIPEL devices. Our results suggest a simple and easy way to realize high-quality white emission.

Visible light active 2D C3N4-CdS hetero-junction photocatalyst for effective removal of azo dye by photodegradation

NASA Astrophysics Data System (ADS)

Ghosh Chaudhuri, Rajib; Chaturvedi, Ashwin; Iype, Eldhose

2018-03-01

A hetero-junction two dimensional photocatalyst that consists of organic semiconductor carbon nitride (C3N4) and inorganic semiconductor CdS, which acts as the light harvesting units and heterogeneous catalyst, was developed for the degradation of azo dye methyl orange (MO). Both materials are visible light active semiconductor. So the effective band gap of this heterojunction materials does not significantly change the visible light activity, but the injection of electrons from excited C3N4 to CdS increases the stability of hole-electron pair and that ultimately enhances the photocatalytic activity. This heterojunction catalyst finally can remove 97% of dyes and that is comparatively higher than individual pure materials. Finally, by using DFT analysis the band structure and the level diagrams of this photocatalyst are also analyzed.

Random lasing from dye-doped negative liquid crystals using ZnO nanoparticles as tunable scatters

NASA Astrophysics Data System (ADS)

Li, Long-Wu; Shang, Zhen-Zhen; Deng, Luogen

2016-09-01

This work demonstrates the realization of a lasing in scattering media, which contains dispersive solution of ZnO nanoparticles (NPs) and laser dye 4-dicyanomethylene-2-methyle-6-(p-dimethylaminostyryl)-4H-pyran(DCM) in negative liquid crystals (LCs) that was injected into a cell. The lasing intensity of the dye-doped negative LC laser can be tuned from low to high if the NPs concentration is increased. The tunability of the laser is attributable to the clusters-sensitive feature in effective refractive index of the negative LCs. Such a tunable negative liquid crystal laser can be used in the fabrication of new optical sources, optical communication, and liquid crystal laser displays. Project supported by the Doctoral Science Research Start-up Funding of Guizhou Normal University, China (Grant No. 11904-0514162) and the National Natural Science Foundation of China (Grant No. 11474021).

Excessive Labeling Technique Provides a Highly Sensitive Fluorescent Probe for Real-time Monitoring of Biodegradation of Biopolymer Pharmaceuticals in vivo.

PubMed

Terekhov, S S; Smirnov, I V; Shamborant, O G; Zenkova, M A; Chernolovskaya, E L; Gladkikh, D V; Murashev, A N; Dyachenko, I A; Knorre, V D; Belogurov, A A; Ponomarenko, N A; Deyev, S M; Vlasov, V V; Gabibov, A G

2014-10-01

Recombinant proteins represent a large sector of the biopharma market. Determination of the main elimination pathways raises the opportunities to significantly increase their half-lives in vivo. However, evaluation of biodegradation of pharmaceutical biopolymers performed in the course of pre-clinical studies is frequently complicated. Noninvasive pharmacokinetic and biodistribution studies in living organism are possible using proteins conjugated with near-infrared dyes. In the present study we designed a highly efficient probe based on fluorescent dye self-quenching for monitoring of in vivo biodegradation of recombinant human butyrylcholinesterase. The maximum enhancement of integral fluorescence in response to degradation of an intravenously administered enzyme was observed 6 h after injection. Importantly, excessive butyrylcholinesterase labeling with fluorescent dye results in significant changes in the pharmacokinetic properties of the obtained conjugate. This fact must be taken into consideration during future pharmacokinetic studies using in vivo bioimaging.

Influence of the electron-cation interaction on electron mobility in dye-sensitized ZnO and TiO2 nanocrystals: a study using ultrafast terahertz spectroscopy.

PubMed

Nemec, H; Rochford, J; Taratula, O; Galoppini, E; Kuzel, P; Polívka, T; Yartsev, A; Sundström, V

2010-05-14

Charge transport and recombination in nanostructured semiconductors are poorly understood key processes in dye-sensitized solar cells. We have employed time-resolved spectroscopies in the terahertz and visible spectral regions supplemented with Monte Carlo simulations to obtain unique information on these processes. Our results show that charge transport in the active solar cell material can be very different from that in nonsensitized semiconductors, due to strong electrostatic interaction between injected electrons and dye cations at the surface of the semiconductor nanoparticle. For ZnO, this leads to formation of an electron-cation complex which causes fast charge recombination and dramatically decreases the electron mobility even after the dissociation of the complex. Sensitized TiO2 does not suffer from this problem due to its high permittivity efficiently screening the charges.

Photodetection of early cancer by laser-induced fluorescence of a tumor-selective dye: apparatus design and realization

NASA Astrophysics Data System (ADS)

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.

Arterial input function of an optical tracer for dynamic contrast enhanced imaging can be determined from pulse oximetry oxygen saturation measurements

NASA Astrophysics Data System (ADS)

Elliott, Jonathan T.; Wright, Eric A.; Tichauer, Kenneth M.; Diop, Mamadou; Morrison, Laura B.; Pogue, Brian W.; Lee, Ting-Yim; St. Lawrence, Keith

2012-12-01

In many cases, kinetic modeling requires that the arterial input function (AIF)—the time-dependent arterial concentration of a tracer—be characterized. A straightforward method to measure the AIF of red and near-infrared optical dyes (e.g., indocyanine green) using a pulse oximeter is presented. The method is motivated by the ubiquity of pulse oximeters used in both preclinical and clinical applications, as well as the gap in currently available technologies to measure AIFs in small animals. The method is based on quantifying the interference that is observed in the derived arterial oxygen saturation (SaO2) following a bolus injection of a light-absorbing dye. In other words, the change in SaO2 can be converted into dye concentration knowing the chromophore-specific extinction coefficients, the true arterial oxygen saturation, and total hemoglobin concentration. A simple error analysis was performed to highlight potential limitations of the approach, and a validation of the method was conducted in rabbits by comparing the pulse oximetry method with the AIF acquired using a pulse dye densitometer. Considering that determining the AIF is required for performing quantitative tracer kinetics, this method provides a flexible tool for measuring the arterial dye concentration that could be used in a variety of applications.

Arterial input function of an optical tracer for dynamic contrast enhanced imaging can be determined from pulse oximetry oxygen saturation measurements.

PubMed

Elliott, Jonathan T; Wright, Eric A; Tichauer, Kenneth M; Diop, Mamadou; Morrison, Laura B; Pogue, Brian W; Lee, Ting-Yim; St Lawrence, Keith

2012-12-21

In many cases, kinetic modeling requires that the arterial input function (AIF)--the time-dependent arterial concentration of a tracer--be characterized. A straightforward method to measure the AIF of red and near-infrared optical dyes (e.g., indocyanine green) using a pulse oximeter is presented. The method is motivated by the ubiquity of pulse oximeters used in both preclinical and clinical applications, as well as the gap in currently available technologies to measure AIFs in small animals. The method is based on quantifying the interference that is observed in the derived arterial oxygen saturation (SaO₂) following a bolus injection of a light-absorbing dye. In other words, the change in SaO₂ can be converted into dye concentration knowing the chromophore-specific extinction coefficients, the true arterial oxygen saturation, and total hemoglobin concentration. A simple error analysis was performed to highlight potential limitations of the approach, and a validation of the method was conducted in rabbits by comparing the pulse oximetry method with the AIF acquired using a pulse dye densitometer. Considering that determining the AIF is required for performing quantitative tracer kinetics, this method provides a flexible tool for measuring the arterial dye concentration that could be used in a variety of applications.

Use of dye tracing to determine ground-water movement to Mammoth Crystal Springs, Sylvan Pass area, Yellowstone National Park, Wyoming

USGS Publications Warehouse

Spangler, Lawrence E.; Susong, David D.

2006-01-01

At the request of and in cooperation with the Geology Program at Yellowstone National Park, the U.S. Geological Survey conducted a hydrologic investigation of the Sylvan Pass area in June 2005 to determine the relation between surface water and ground-water flow to Mammoth Crystal Springs. Results of a dye-tracing investigation indicate that streamflow lost into talus deposits on Sylvan Pass enters the ground-water system and moves to the southeast to discharge at Mammoth Crystal Springs. Ground-water travel times to the springs from a distance of 1.45 miles and a vertical relief of 500 feet were less than 1 day, indicating apparent rates of movement of at least 8,000 feet per day, values that are similar to those in karst aquifers. Peak dye concentrations were reached about 2 days after dye injection, and transit time of most of the dye mass through the system was about 3 weeks. High permeability and rapid travel times within this aquifer also are indicated by the large variation in springflow in response to snowmelt runoff and precipitation, and by the high concentration of suspended sediment (turbidity) in the water discharging into the spring-fed lake.

Imaging the Ultrafast Photoelectron Transfer Process in Alizarin-TiO2.

PubMed

Gomez, Tatiana; Hermann, Gunter; Zarate, Ximena; Pérez-Torres, Jhon Fredy; Tremblay, Jean Christophe

2015-07-30

In this work, we adopt a quantum mechanical approach based on time-dependent density functional theory (TDDFT) to study the optical and electronic properties of alizarin supported on TiO2 nano-crystallites, as a prototypical dye-sensitized solar cell. To ensure proper alignment of the donor (alizarin) and acceptor (TiO2 nano-crystallite) levels, static optical excitation spectra are simulated using time-dependent density functional theory in response. The ultrafast photoelectron transfer from the dye to the cluster is simulated using an explicitly time-dependent, one-electron TDDFT ansatz. The model considers the δ-pulse excitation of a single active electron localized in the dye to the complete set of energetically accessible, delocalized molecular orbitals of the dye/nano-crystallite complex. A set of quantum mechanical tools derived from the transition electronic flux density is introduced to visualize and analyze the process in real time. The evolution of the created wave packet subject to absorbing boundary conditions at the borders of the cluster reveal that, while the electrons of the aromatic rings of alizarin are heavily involved in an ultrafast charge redistribution between the carbonyl groups of the dye molecule, they do not contribute positively to the electron injection and, overall, they delay the process.

Methylene blue dyeing of cellular nuclei during salpingoscopy, a new in-vivo method to evaluate vitality of tubal epithelium.

PubMed

Marconi, G; Quintana, R

1998-12-01

The Fallopian tube can be damaged by different noxious substances that may change cellular ultrastructure and function. Alteration of the cell membrane allows the passage of certain aniline dyes, which can stain the nucleus. A total of 310 Fallopian tubes from 163 patients who underwent a surgical or diagnostic laparoscopy during fertility studies was analysed by salpingoscopy. Cellular nuclei were stained by injection of 20 ml of a 10% solution of methylene blue in saline solution (NaCl 10%) through the cervical cannula prior to salpingoscopy. Evaluation of nuclear staining with methylene blue, adhesions, vascular alterations, and the flattening of folds in relation to pregnancy outcome was undertaken. Quantification of salpingoscopic findings was carried out according to a score. Flattening of folds and vascular alterations showed no difference in the pregnant and non-pregnant groups. On the other hand, adhesions and nuclear dyeing were significantly greater in the non-pregnant group (adhesions 13.6 versus 26.8%, P < 0.004, and nuclear dyeing: 25 versus 41.7%, P < 0.009, pregnant versus non-pregnant). Methylene blue dye is a new tool to evaluate in vivo cyto-histological tubal damage, and is a useful and simple method to provide a prognosis of salpingean function.

Everything you always wanted to know about black dye (but were afraid to ask): a DFT/TDDFT investigation.

PubMed

Fantacci, Simona; Lobello, Maria G; De Angelis, Filippo

2013-01-01

We report an exhaustive theoretical and computational investigation of the electronic, optical, redox and acid-base properties, along with the adsorption mode on TiO2, of Black Dye (BD), the prototypical panchromatic dye for solar cell applications. We investigated in detail the variation of the relevant dye properties as a function of the solution pH, corresponding to the stepwise deprotonation of the carboxylic groups. Our results reproduced the expected blue-shift of the optical absorption spectrum and the experimental trend of oxidation potentials by increasing pH, which turned both out to be in excellent agreement with experimental values. Also, our calculated excited state oxidation potential is in good agreement with available experimental data. We then looked at the pKa of the various deprotonation steps, finding lowest pKa values for the stepwise dissociation of three protons of 2.71, 3.69 and 5.20, in excellent agreement with experimental pKa values of 3 and 5, for two and one protons dissociation, respectively. We finally investigated the adsorption of BD on TiO2, finding the most stable adsorption to occur via two dissociated monodentate carboxylic groups. Inspection of the electronic structure and alignment of energy levels for N719 and BD revealed a reduced driving force for electron injection in the latter dye, which could possibly lead to energetically unfavorable electron transfer from the excited dye to the TiO2 conduction band. Our results may constitute a reference study for future investigations and optimization of BD-based dye-sensitized solar cells.

Exploring the relevance of thiophene rings as bridge unit in acceptor-bridge-donor dyes on self-aggregation and performance in DSSCs.

PubMed

Zarate, Ximena; Saavedra-Torres, Mario; Rodriguez-Serrano, Angela; Gomez, Tatiana; Schott, Eduardo

2018-04-30

The possibility of dye charge recombination in DSSCs remains a challenge for the field. This consists of: (a) back-transfer from the TiO 2 to the oxidized dye and (b) intermolecular electron transfer between dyes. The latter is attributed to dye aggregation due to dimeric conformations. This leads to poor electron injection which decreases the photocurrent conversion efficiency. Most organic sensitizers are characterized by an Acceptor-Bridge-Donor (A-Bridge-D) arrangement that is commonly employed to provide charge separation and, therefore, lowering the unwanted back-transfer. Here, we address the intermolecular electron transfer by studying the dimerization and photovoltaic performance of a group of A-Bridge-D structured dyes. Specifically, eight famous sulfur containing π-bridges were analyzed (A and D remained fixed). Through quantum mechanical and molecular dynamics approaches, it was found that the formation of weakly stabilized dimers is allowed. The dyes with covalently bonded and fused thiophene rings as Bridges, 6d and 7d as well as 8d with a fluorene, would present high aggregation and, therefore, high probability of recombination processes. Conversely, using TiO 2 cluster and surface models, delineated the shortest bridges to improve the adsorption energy and the stability of the system. Finally, the elongation of the bridge up to 2 and 3 units and their photovoltaic parameters were studied. These results showed that all the sensitizers are able to provide similar photocurrent outcomes, regardless of whether the bridge is elongated. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Hydraulic complexity, larval drift, and endangered species recovery in the Upper Missouri River

NASA Astrophysics Data System (ADS)

Erwin, S. O.; Bulliner, E. A., IV; Jacobson, R. B.; Fischenich, C. J.; Braaten, P.

2016-12-01

Connectivity is recognized as an important attribute of river ecosystems. In highly fragmented rivers restoring longitudinal connectivity is often difficult or impossible. In systems where removal of dams is not viable and bypass does not address needs of target fish species, manipulation of flows to meet requirements of aquatic organisms may aid species recovery. Such is the case in the Missouri River basin, where dams and reservoirs impede fish migration and larval drift, critical life history events for many species, notably the endangered pallid sturgeon. In 2016, we conducted a large-scale dye-trace experiment in the Upper Missouri River downstream from Fort Peck Reservoir, MT. A slug injection of Rhodamine WT was tracked and measured over a 135-km reach. Direct measurements of downstream dye concentrations were used to calibrate a one-dimensional advection-dispersion model, which is being used to explore alternative reservoir operations for Fort Peck and the downstream reservoir, Lake Sakakawea. Results are used to evaluate the effects of flow regulation on dispersal of endangered sturgeon larvae. Additionally, we employ a two-dimensional hydrodynamic model to evaluate particle residence times and inform understanding of hydraulic processes that may control the shape of breakthrough curves observed from the field experiment. Lateral connectivity also has a potential role in river management and species recovery. Reservoir management can determine whether flow is contained within the channel, where dispersion is low, or laterally connected to rough floodplains which can result in high dispersion, long-tailed particle residence times, and greater opportunities for drifting larvae to transition to exogenous feeding and survive. We discuss our findings in the context of basin-wide restoration efforts and highlight the critical contributions of both large-scale field experiments and numerical modeling to inform management.

The Quantitative Determination of Food Dyes in Powdered Drink Mixes: A High School or General Science Experiment

ERIC Educational Resources Information Center

Sigmann, Samuella B.; Wheeler, Dale E.

2004-01-01

The development of a simple spectro photometric method to quantitatively determine the quantity of FD&C color additives present in powdered drink mixes, are focused by the investigations. Samples containing single dyes of binary mixtures of dyes can be analyzed using this method.

Thermal damage assessment of blood vessels in a hamster skin flap model by fluorescence measurement of a liposome-dye system.

PubMed

Mordon, S; Desmettre, T; Devoisselle, J M; Soulie, S

1997-01-01

The present study was undertaken to evaluate the feasibility of thermal damage assessment of blood vessels by using laser-induced release of liposome-encapsulated dye. Experiments were performed in a hamster skin flap model. Laser irradiation was achieved with a 300 microm fiber connected to a 805 nm diode laser (power = 0.8W, spot diameter = 1.3 mm and pulse exposure time lasting from 1 to 6 s) after potentiation using a specific indocyanine green (ICG) formulation (water and oil emulsion). Liposomes-encapsulated carboxyfluorescein were prepared by the sonication procedure. Carboxyfluorescein (5,6-CF) was loaded at high concentration (100 mM) in order to quench its fluorescence. The measurements were performed after i.v. injection of DSPC liposomes (1.5 ml) and lasted 40 min. Fluorescence emission was measured with an ultra high sensitivity intensified camera. Three different shapes of fluorescent spots were identified depending on target (blood vessel or skin) and energy deposition in tissue: (i) intravascular fluorescence, (ii) transient low fluorescence circular spot, and (iii) persistent high intense fluorescence spot. These images are correlated with histological data. Real-time fluorescence imaging seems to be a good tool to estimate in a non-invasive manner the thermal damage induced by a diode laser combined with ICG potentiation.

Fast simultaneous assessment of renal and liver function using polymethine dyes in animal models of chronic and acute organ injury.

PubMed

Press, A T; Butans, M J; Haider, T P; Weber, C; Neugebauer, S; Kiehntopf, M; Schubert, U S; Clemens, M G; Bauer, M; Kortgen, A

2017-11-13

Simultaneous assessment of excretory liver and kidney function is still an unmet need in experimental stress models as well as in critical care. The aim of the study was to characterize two polymethine-dyes potentially suitable for this purpose in vivo. Plasma disappearance rate and elimination measurements of simultaneously injected fluorescent dyes DY-780 (hepato-biliary elimination) and DY-654(renal elimination) were conducted using catheter techniques and intravital microscopy in animals subjected to different organ injuries, i.e. polymicrobial sepsis by peritoneal contamination and infection, ischemia-reperfusion-injury and glycerol-induced acute kidney-injury. DY-780 and DY-654 showed organ specific and determined elimination routes in both healthy and diseased animals. They can be measured simultaneously using near-infrared imaging and spectrophotometry. Plasma-disappearance rates of DY-780 and DY-654 are superior to conventional biomarkers in indicating hepatic or kidney dysfunction in different animal models. Greatest impact on liver function was found in animals with polymicrobial sepsis whereas glomerular damage due to glycerol-induced kidney-injury had strongest impact on DY-654 elimination. We therefore conclude that hepatic elimination and renal filtration can be assessed in rodents measuring plasma-disappearance rates of both dyes. Further, assessment of organ dysfunction by polymethine dyes correlates with, but outperforms conventional biomarkers regarding sensitivity and the option of spatial resolution if biophotonic strategies are applied. Polymethine-dye clearance thereby allows sensitive point-of-care assessment of both organ functions simultaneously.

Organic sensitizers featuring thiophene derivative based donors with improved stability and photovoltaic performance.

PubMed

Miao, Kai; Liang, Mao; Wang, Zhihui; Zhang, Chunyao; Sun, Zhe; Xue, Song

2017-01-18

Thiophene derivatives, including thieno[3,2-b][1]benzothiophene (TBT), benzo[b]thiophene (BT), 2-phenylthieno[3,2-b]thiophene (PTT) and 2-phenylthiophene (PT), have been introduced as donors for the construction of triarylamine organic dyes (M52, M53, M56, M57 and M52A). The absorption, electrochemical and photovoltaic properties as well as the stabilities of these dyes are systematically investigated and compared with the reference dye (M55), whose donor is composed of the hexyloxybenzene (HOB) unit. It is found that introducing the TBT, BT, PTT or PT donors positively shifted the HOMO and LUMO levels of the organic dyes, providing a larger driving force for regeneration and reducing the energy loss for electron injection. In addition, we found that M52, which contains the TBT unit, exhibited better photovoltaic performance and photostability as compared to the reference dye. In contrast, M53 displayed the lowest efficiency and stability of these dyes, indicating that the BT unit is not a good building block for donors. Interestingly, upon the incorporation of the mixed donor (TBT-HOB), M52A achieved a desirable driving force for regeneration without a loss in light absorption, thus resulting in a further improved photovoltaic performance with respect to that of M52. This work demonstrates that introducing donors based on thiophene derivatives is a good strategy for tuning the energy levels and thereby enhancing the efficiency of the resulting devices.

Synthesis of Triarylmethane and Xanthene Dyes Using Electrophilic Aromatic Substitution Reactions

ERIC Educational Resources Information Center

McCullagh, James V.; Daggett, Kelly A.

2007-01-01

The synthesis of dyes has long been a popular topic in organic chemistry laboratory experiments because it allows students to see first hand that reactions learned in class can be used to make compounds with useful applications. In this experiment electrophilic aromatic substitution reactions are used to synthesize several triarylmethane and…

Photocatalytic Destruction of an Organic Dye Using TiO2 and Solar Energy.

ERIC Educational Resources Information Center

Giglio, Kimberly D.; And Others

1995-01-01

Describes a general chemistry experiment that is carried out in sunlight to illustrate the ability of TiO2 to act as a photocatalyst by mineralizing an organic dye into carbon dioxide. Details about the construction of the reactor system used to perform this experiment are included. (DDR)

Home-made experiment of Dye-sensitized TiO2 Nanocrystalline Solar Cells and its education evaluation

NASA Astrophysics Data System (ADS)

Tai, M. F.; Shieh, M. C.; Chen, T. W.

2010-03-01

Dyes extracted from some natural fruits including anthocyanins absorb sunlight and effectively activate electrons of anthocyanins. Thus these activated electrons are conducted between TiO2 nanocrystals and form electric potential and current between two electrodes. The dyes can be gotten from the natural fruits, such as blackberries, raspberry, pomegranate seeds and bing cherries. This principle permits making a dye sensitized TiO2 nanocrystallines solar cell (DSSC). All required materials and tools for fabricating a home- made DSSC are easy to obtain around home. The procedures are perfect hands-on experiment as well as demonstration in K-12 schools or home settings. We have designed several protocols for fabricating DSSC and have successfully demonstrated in more than 100 activities with different level students. K-12 Students were able to build their own working DSSC's within 2-3 hours sessions and learned about alternative energy sources. These experiments can inspire students and general public about the modern technology in daily life. Low cost (low than US 3 in Taiwan)and safety are also ensured in our DSSC experiments.

Optical properties of cyanine dyes in nanotubes of chrysotile asbestos

NASA Astrophysics Data System (ADS)

Starovoytov, Anton A.; Vartanyan, Tigran A.; Belotitskii, Vladimir I.; Kumzerov, Yuri A.; Sysoeva, Anna A.

2017-08-01

Optical properties of cyanine dye molecules incorporated in nanotubes of natural chrysotile asbestos are studied. The absorption and fluorescence spectra of dye in asbestos have the similar shapes as in the ethanol solution, apart from small blue shift of the maxima. The Stokes shift in asbestos is smaller than in the ethanol solution. The fluorescence decay times of the dyes in asbestos nanotubes are found to be larger than that in the case of thin films of the same dyes formed on the transparent dielectric supports. This observation is rationalized in terms of the stereoisomerization hindrance in the excited electronic state of dye molecules. At the same time linear dichroism and fluorescence anisotropy observed in the experiment indicate that the embedded dye molecules are well-isolated monomer oriented predominantly along asbestos nanotubes.

Sentinel lymph node biopsy under fluorescent indocyanin green guidance: Initial experience

PubMed Central

Aydoğan, Fatih; Arıkan, Akif Enes; Aytaç, Erman; Velidedeoğlu, Mehmet; Yılmaz, Mehmet Halit; Sager, Muhammet Sait; Çelik, Varol; Uras, Cihan

2016-01-01

Objective: Sentinel lymph node biopsy can be applied by using either blue dye or radionuclide method or both in breast cancer. Fluorescent imaging with indocyanine green is a new defined method. This study evaluates the applicability of sentinel lymph node biopsy via fluorescent indocyanine green. Material and Methods: IC-VIEW (Pulsion Medical Systems AG, Munich, Germany) infrared visualization system was used for imaging. Two mL of indocyanine green was injected to visualize sentinel lymph nodes. After injection, subcutaneous lymphatics were traced and sentinel lymph nodes were found with simultaneous imaging. Sentinel lymph nodes were excised under fluorescent light guidance, and excised lymph nodes were examined histopathologically. Patients with sentinel lymph node metastases underwent axillary dissection. Results: Four patients with sentinel lymph node biopsy due to breast cancer were included in the study. Sentinel lymph nodes were visualized with indocyanine green in all patients. The median number of excised sentinel lymph node was 2 (2–3). Two patients with lymph node metastasis underwent axillary dissection. No metastasis was detected in lymph nodes other than the sentinel nodes in patients with axillary dissection. There was no complication during and after the operation related to the method. Conclusion: According to our limited experience, sentinel lymph node biopsy under fluorescent indocyanine green guidance, which has an advantage of simultaneous visualization, is technically feasible. PMID:26985159

Structural Heterogeneity and Quantitative FRET Efficiency Distributions of Polyprolines through a Hybrid Atomistic Simulation and Monte Carlo Approach

PubMed Central

Hoefling, Martin; Lima, Nicola; Haenni, Dominik; Seidel, Claus A. M.; Schuler, Benjamin; Grubmüller, Helmut

2011-01-01

Förster Resonance Energy Transfer (FRET) experiments probe molecular distances via distance dependent energy transfer from an excited donor dye to an acceptor dye. Single molecule experiments not only probe average distances, but also distance distributions or even fluctuations, and thus provide a powerful tool to study biomolecular structure and dynamics. However, the measured energy transfer efficiency depends not only on the distance between the dyes, but also on their mutual orientation, which is typically inaccessible to experiments. Thus, assumptions on the orientation distributions and averages are usually made, limiting the accuracy of the distance distributions extracted from FRET experiments. Here, we demonstrate that by combining single molecule FRET experiments with the mutual dye orientation statistics obtained from Molecular Dynamics (MD) simulations, improved estimates of distances and distributions are obtained. From the simulated time-dependent mutual orientations, FRET efficiencies are calculated and the full statistics of individual photon absorption, energy transfer, and photon emission events is obtained from subsequent Monte Carlo (MC) simulations of the FRET kinetics. All recorded emission events are collected to bursts from which efficiency distributions are calculated in close resemblance to the actual FRET experiment, taking shot noise fully into account. Using polyproline chains with attached Alexa 488 and Alexa 594 dyes as a test system, we demonstrate the feasibility of this approach by direct comparison to experimental data. We identified cis-isomers and different static local environments as sources of the experimentally observed heterogeneity. Reconstructions of distance distributions from experimental data at different levels of theory demonstrate how the respective underlying assumptions and approximations affect the obtained accuracy. Our results show that dye fluctuations obtained from MD simulations, combined with MC single photon kinetics, provide a versatile tool to improve the accuracy of distance distributions that can be extracted from measured single molecule FRET efficiencies. PMID:21629703

Measuring the Dispersion Curve of a PMMA-Fibre Optic Cable Using a Dye Laser

ERIC Educational Resources Information Center

Zorba, Serkan; Farah, Constantine; Pant, Ravi

2010-01-01

An advanced undergraduate laboratory experiment is outlined which uses a dye laser to map out the chromatic dispersion curve of a polymethyl methacrylate (PMMA) optical fibre. Seven different wavelengths across the visible spectrum are employed using five different dyes. The light pulse is split into two pulses, one to a nearby photodetector and…

Improved Dye Stability in Single-Molecule Fluorescence Experiments

NASA Astrophysics Data System (ADS)

EcheverrÍa Aitken, Colin; Marshall, R. Andrew; Pugi, Joseph D.

Complex biological systems challenge existing single-molecule methods. In particular, dye stability limits observation time in singlemolecule fluorescence applications. Current approaches to improving dye performance involve the addition of enzymatic oxygen scavenging systems and small molecule additives. We present an enzymatic oxygen scavenging system that improves dye stability in single-molecule experiments. Compared to the currently-employed glucose-oxidase/catalase system, the protocatechuate-3,4-dioxygenase system achieves lower dissolved oxygen concentration and stabilizes single Cy3, Cy5, and Alexa488 fluorophores. Moreover, this system possesses none of the limitations associated with the glucose oxidase/catalase system. We also tested the effects of small molecule additives in this system. Biological reducing agents significantly destabilize the Cy5 fluorophore as a function of reducing potential. In contrast, anti-oxidants stabilize the Cy3 and Alexa488 fluorophores. We recommend use of the protocatechuate-3,4,-dioxygenase system with antioxidant additives, and in the absence of biological reducing agents. This system should have wide application to single-molecule fluorescence experiments.

Use of dyes in cariology.

PubMed

van de Rijke, J W

1991-04-01

The property of dyes to enhance contrast by their colour can be used in clinical dentistry and in investigations in vitro or in vivo. They have been used for indication of affected dental tissues, improvement of diagnostic methods, enhancement of patient awareness and information about specific processes. The development of particular dye systems, aimed at clinical application, is often laborious because of toxic effects, lack of specificity, irreversible staining or difficulties with removal of the dye. Clinically used dyes are often visually observed, which means a qualitative assessment of the staining, while quantification of the staining, if performed at all, is confined mostly to laboratory experiments. In this paper the application of dyes, arranged according to their specific purpose in cariology, is discussed, and a brief historical overview is given of the development of two particular dye applications for which commercial dye systems are now available. If certain requirements are met, dyes can be of great help in detection and quantification when used with several diagnostic methods.

Electronic and chemical structure of an organic light emitter embedded in an inorganic wide-bandgap semiconductor: Photoelectron spectroscopy of layered and composite structures of Ir(BPA) and ZnSe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dimamay, Mariel; Laboratoire de Chimie des Polymères Organiques, CNRS, Université de Bordeaux, UMR 5629-16 Avenue Pey-Berland, 33607 Pessac; Mayer, Thomas

Luminescent organic phases embedded in conductive inorganic matrices are proposed for hybrid organic-inorganic light-emitting diodes. In this configuration, the organic dye acts as the radiative recombination site for charge carriers injected into the inorganic matrix. Our investigation is aimed at finding a material combination where the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the organic dye are situated in between the valence and conduction bands of the inorganic matrix in order to promote electron and hole transfer from the matrix to the dye. Bilayer and composite thin films of zinc selenide (ZnSe) and a redmore » iridium complex (Ir(BPA)) organic light emitter were prepared in situ via UHV thermal evaporation technique. The electronic and atomic structures were studied applying X-ray and ultraviolet photoelectron spectroscopies. The measured energy band alignments for the ZnSe/Ir(BPA) bilayer and ZnSe+Ir(BPA) composite reveal that the HOMO and LUMO of the organic dye are positioned in the ZnSe bandgap. For the initial steps of ZnSe deposition on a dye film to form Ir(BPA)/ZnSe bilayers, zinc atoms intercalate into the dye film leaving behind an excess of selenium at the interface that partly reacts with dye molecules. Photoelectron spectroscopy of the composites shows the same species suggesting a similar mechanism. This mechanism leads to composite films with increased content of amorphous phases in the inorganic matrix, thereby affecting its conductivity, as well as to the presence of nonradiative recombination sites provided by the intercalated Zn atoms.« less

Investigation of decolorization of textile wastewater in an anaerobic/aerobic biological activated carbon system (A/A BAC).

PubMed

Pasukphun, N; Vinitnantharat, S; Gheewala, S

2010-04-01

The aim of this study is to investigate the decolorization in anaerobic/aerobic biological activated carbon (A/A BAC) system. The experiment was divided into 2 stages; stage I is batch test for preliminary study of dye removal equilibrium time. The preliminary experiment (stage I) provided the optimal data for experimental design of A/A BAC system in SBR (stage II). Stage II is A/A BAC system imitated Sequencing Batch Reactor (SBR) which consist of 5 main periods; fill, react, settle, draw and idle. React period include anaerobic phase followed by aerobic phase. The BAC main media; Granular Activated Carbon (GAC), Mixed Cultures (MC) and Biological Activated Carbon (BAC) were used for dye and organic substances removal in three different solutions; Desizing Agent Solution (DAS), dye Solution (DS) and Synthetic Textile Wastewater (STW). Results indicate that GAC adsorption plays role in dye removal followed by BAC and MC activities, respectively. In the presence desizing agent, decolorization by MC was improved because desizing agent acts as co-substrates for microorganisms. It was found that 50% of dye removal efficiency was achieved in Fill period by MC. GC/MS analysis was used to identify dye intermediate from decolorization. Dye intermediate containing amine group was found in the solution and on BAC surfaces. The results demonstrated that combination of MC and BAC in the system promotes decolorization and dye intermediate removal. In order to improve dye removal efficiency in an A/A BAC system, replacement of virgin GAC, sufficient co-substrates supply and the appropriate anaerobic: aerobic period should be considered.

Sentinel lymph node detection by an optical method using scattered photons

PubMed Central

Tellier, Franklin; Ravelo, Rasata; Simon, Hervé; Chabrier, Renée; Steibel, Jérôme; Poulet, Patrick

2010-01-01

We present a new near infrared optical probe for the sentinel lymph node detection, based on the recording of scattered photons. A two wavelengths setup was developed to improve the detection threshold of an injected dye: the Patent Blue V dye. The method used consists in modulating each laser diode at a given frequency. A Fast Fourier Transform of the recorded signal separates both components. The signal amplitudes are used to compute relative Patent Blue V concentration. Results on the probe using phantoms model and small animal experimentation exhibit a sensitivity threshold of 3.2 µmol/L, which is thirty fold better than the eye visible threshold. PMID:21258517

Fluorometric procedures for dye tracing

USGS Publications Warehouse

Wilson, James F.; Cobb, Ernest D.; Kilpatrick, F.A.

1986-01-01

This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The advantages of dye tracing are (1) low detection and measurement limits and (2) simplicity and accuracy in measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section on aerial photography is included because of its possible use to supplement ground-level fluorometry.

Fluorometric procedures for dye tracing

USGS Publications Warehouse

Wilson, James F.

1968-01-01

This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The advantages of dye tracing are (1) low detection and measurement limits and (2) simplicity and accuracy in measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section on aerial photography is included because of its possible use to supplement ground-level fluorometry.

Fluorometric procedures for dye tracing

USGS Publications Warehouse

Wilson, James E.; Cobb, Ernest D.; Kilpatrick, Frederick A.

1984-01-01

This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The outstanding characteristics of dye tracing are: (1) the low detection and measurement limits, and (2) the simplicity and accuracy of measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a general guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section is included on aerial photography because of its possible use to supplement ground-level fluorometry.

Synthesis and spectroscopic properties of silica-dye-semiconductor nanocrystal hybrid particles.

PubMed

Ren, Ting; Erker, Wolfgang; Basché, Thomas; Schärtl, Wolfgang

2010-12-07

We prepared silica-dye-nanocrystal hybrid particles and studied the energy transfer from semiconductor nanocrystals (= donor) to organic dye molecules (= acceptor). Multishell CdSe/CdS/ZnS semiconductor nanocrystals were adsorbed onto monodisperse Stöber silica particles with an outer silica shell of thickness 2-23 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the energy transfer efficiency, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of nanocrystals with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with numerically calculated FRET efficiencies and by control experiments confirming attractive interaction between the nanocrystals and Texas Red freely dissolved in solution.

Surface modifications of photoanodes in dye sensitized solar cells: enhanced light harvesting and reduced recombination

NASA Astrophysics Data System (ADS)

Saxena, Vibha; Aswal, D. K.

2015-06-01

In a quest to harvest solar power, dye-sensitized solar cells (DSSCs) have potential for low-cost eco-friendly photovoltaic devices. The major processes which govern the efficiency of a DSSC are photoelectron generation, injection of photo-generated electrons to the conduction band (CB) of the mesoporous nanocrystalline semiconductor (nc-SC); transport of CB electrons through nc-SC and subsequent collection of CB electrons at the counter electrode (CE) through the external circuit; and dye regeneration by redox couple or hole transport layer (HTL). Most of these processes occur at various interfaces of the photoanode. In addition, recombination losses of photo-generated electrons with either dye or redox molecules take place at the interfaces. Therefore, one of the key requirements for high efficiency is to improve light harvesting of the photoanode and to reduce the recombination losses at various interfaces. In this direction, surface modification of the photoanode is the simplest method among the various other approaches available in the literature. In this review, we present a comprehensive discussion on surface modification of the photoanode, which has been adopted in the literature for not only enhancing light harvesting but also reducing recombination. Various approaches towards surface modification of the photoanode discussed are (i) fluorine-doped tin oxide (FTO)/nc-SC interface modified via a compact layer of semiconductor material which blocks exposed sites of FTO to electrolyte (or HTL), (ii) nc-SC/dye interface modification either through acid treatment resulting in enhanced dye loading due to a positively charged surface or by depositing insulating/semiconducting blocking layer on the nc-SC surface, which acts as a tunneling barrier for recombination, (iii) nc-SC/dye interface modified by employing co-adsorbents which helps in reducing the dye aggregation and thereby recombination, and (iv) dye/electrolyte (or dye/HTL) interface modification using additives which provides surface passivation as well as positive movement of the nc-SC Fermi level owing to negative charge at the surface and hence improves light harvesting and reduced recombination. Finally, we discuss the advantages and disadvantages of various approaches towards high-efficiency DSSCs.

Enhanced photocurrent production by bio-dyes of photosynthetic macromolecules on designed TiO2 film

PubMed Central

Yu, Daoyong; Wang, Mengfei; Zhu, Guoliang; Ge, Baosheng; Liu, Shuang; Huang, Fang

2015-01-01

The macromolecular pigment-protein complex has the merit of high efficiency for light-energy capture and transfer after long-term photosynthetic evolution. Here bio-dyes of A. platensis photosystem I (PSI) and spinach light-harvesting complex II (LHCII) are spontaneously sensitized on three types of designed TiO2 films, to assess the effects of pigment-protein complex on the performance of bio-dye sensitized solar cells (SSC). Adsorption models of bio-dyes are proposed based on the 3D structures of PSI and LHCII, and the size of particles and inner pores in the TiO2 film. PSI shows its merit of high efficiency for captured energy transfer, charge separation and transfer in the electron transfer chain (ETC), and electron injection from FB to the TiO2 conducting band. After optimization, the best short current (JSC) and photoelectric conversion efficiency (η) of PSI-SSC and LHCII-SSC are 1.31 mA cm-2 and 0.47%, and 1.51 mA cm-2 and 0.52%, respectively. The potential for further improvement of this PSI based SSC is significant and could lead to better utilization of solar energy. PMID:25790735

Spectroscopic (FT-IR, FT-Raman and UV-Visible) investigations, NMR chemical shielding anisotropy (CSA) parameters of 2,6-Diamino-4-chloropyrimidine for dye sensitized solar cells using density functional theory.

PubMed

Gladis Anitha, E; Joseph Vedhagiri, S; Parimala, K

2015-02-05

The molecular structure, geometry optimization, vibrational frequencies of organic dye sensitizer 2,6-Diamino-4-chloropyrimidine (DACP) were studied based on Hartree-Fock (HF) and density functional theory (DFT) using B3LYP methods with 6-311++G(d,p) basis set. Ultraviolet-Visible (UV-Vis) spectrum was investigated by time dependent DFT (TD-DFT). Features of the electronic absorption spectrum in the UV-Visible regions were assigned based on TD-DFT calculation. The absorption bands are assigned to transitions. The interfacial electron transfer between semiconductor TiO2 electrode and dye sensitizer DACP is due to an electron injection process from excited dye to the semiconductor's conduction band. The observed and the calculated frequencies are found to be in good agreement. The energies of the frontier molecular orbitals (FMOS) have also been determined. The chemical shielding anisotropic (CSA) parameters are calculated from the NMR analysis, Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Improved distribution of small molecules and viral vectors in the murine brain using a hollow fiber catheter

PubMed Central

Seunguk, Oh; Odland, Rick; Wilson, Scott R.; Kroeger, Kurt M.; Liu, Chunyan; Lowenstein, Pedro R.; Castro, Maria G.; Hall, Walter A.; Ohlfest, John R.

2008-01-01

Object A hollow fiber catheter was developed to improve the distribution of drugs administered via direct infusion into the central nervous system (CNS). It is a porous catheter that significantly increases the surface area of brain tissue into which a drug is infused. Methods Dye was infused into the mouse brain through convection-enhanced delivery (CED) using a 28-gauge needle compared with a 3-mm-long hollow fiber catheter. To determine whether a hollow fiber catheter could increase the distribution of gene therapy vectors, a recombinant adenovirus expressing the firefly luciferase reporter was injected into the mouse striatum. Gene expression was monitored using in vivo bioluminescent imaging. To assess the distribution of gene transfer, an adenovirus expressing green fluorescent protein was injected into the striatum using a hollow fiber catheter or a needle. Results Hollow fiber catheter—mediated infusion increased the volume of brain tissue labeled with dye by 2.7 times relative to needle-mediated infusion. In vivo imaging revealed that catheter-mediated infusion of adenovirus resulted in gene expression that was 10 times greater than that mediated by a needle. The catheter appreciably increased the area of brain transduced with adenovirus relative to a needle, affecting a significant portion of the injected hemisphere. Conclusions The miniature hollow fiber catheter used in this study significantly increased the distribution of dye and adenoviral-mediated gene transfer in the mouse brain compared with the levels reached using a 28-gauge needle. Compared with standard single-port clinical catheters, the hollow fiber catheter has the advantage of millions of nanoscale pores to increase surface area and bulk flow in the CNS. Extending the scale of the hollow fiber catheter for the large mammalian brain shows promise in increasing the distribution and efficacy of gene therapy and drug therapy using CED. PMID:17886557

Fluorescence measurement of diode (805 nm) laser-induced release of 5,6-CF from DSPC liposomes for monitoring of temperature: an in vivo study in rat liver using indocyanine green potentiation

NASA Astrophysics Data System (ADS)

Mordon, Serge R.; Desmettre, Thomas; Devoisselle, Jean-Marie; Soulie-Begu, Sylvie

1995-05-01

This in-vivo study examines the validity of fluorescence measurement of laser-induced release of temperature sensitive liposome-encapsulated dye for monitoring of temperature and prediction of tissue thermal damage. It is performed in rat liver after i.v. injection of liposomes loaded with a fluorescent dye and i.v. injection of Indocyanine Green (ICG) for diode laser potentiation. Temperature sensitive liposomes (DSPC: Di- Stearoyl-Phosphatidyl-Choline) are loaded with 5,6-Carboxyfluorescein (5,6-CF). These liposomes (1.5 ml solution) and ICG (1.5 ml solution-5 mg/kg) are injected to adult male wistar rats. Two hours later, the liver is exposed and irradiated with a 0.8 W diode laser using pulses lasting from 1 s to 6 s (fluence ranging from 16 to 98 J/cm+2)). Simultaneously, the fluorescence emission is measured with a fluorescent imaging system. Results show that the fluorescence intensity increases linearly form 18 J/cm2 up to 75 J/cm2. These fluences correspond to surface temperatures between 42°C to 64°C. The measurements appear to be highly reproducible. In this temperature range, the accuracy is +/- 3°C. The maximum intensity is observed immediately after the laser is switched off and a decrease of the fluorescence intensity is observed (27% in 20 minutes) due to the 5.6-CF clearance. However, the ratio (IF/Ibck) remains almost stable over this period of time and the determination of the temperature is still possible with a good accuracy even 20 minutes after laser irradiation. In conclusion, temperature monitoring by using fluorescence measurement of laser-induced release of liposome-encapsulated dye is clearly demonstrated. This procedure could conceivably prove useful for controlling the thermal coagulation of biological tissues.

Canalicular laceration repair using a viscoelastic injection to locate and dilate the proximal torn edge.

PubMed

Örge, Faruk H; Dar, Suhail A

2015-06-01

Canalicular lacerations are common complications of eyelid trauma in the pediatric population. Irrigating air, water, and colored or viscous agents through the intact canaliculus have been suggested to identify the torn proximal edge. We report our experience in repairing canalicular lacerations using a novel viscoelastic injection technique with a Monoka monocanalicular stent. The medical records of patients <18 years of age who underwent repair of a canalicular laceration with a monocanalicular stent using superficial viscoelastic deployment to locate the torn canaliculus were retrospectively reviewed. Demographics, cause of eyelid injury, surgical management using our novel viscoelastic injection technique, and outcome were analyzed. A total of 38 children with lid lacerations were identified, of whom the 17 with canalicular involvement were included (mean age, 6.27 years). Canalicular injury in these 17 was due to dog bite (9 patients) and shearing trauma (8 patients). In 11 patients, the injury was located in the lower lid; in 4, the upper lid; and in 2, combined upper and lower lids. All patients had good anatomic repair and on follow-up had negative dye disappearance tests and were free of tearing. Deploying viscoelastic superficially near, and injecting into the injured canaliculus can improve visualization of the operative field by retracting the surrounding tissue and tamponading any bleeding, which aids in location and dilation of the torn canaliculus initially and in subsequent steps, eases intubation into the lubricated torn canaliculus and nasolacrimal duct, and avoids iatrogenic injury to an uninjured canaliculus. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Accurate distance determination of nucleic acids via Förster resonance energy transfer: implications of dye linker length and rigidity.

PubMed

Sindbert, Simon; Kalinin, Stanislav; Nguyen, Hien; Kienzler, Andrea; Clima, Lilia; Bannwarth, Willi; Appel, Bettina; Müller, Sabine; Seidel, Claus A M

2011-03-02

In Förster resonance energy transfer (FRET) experiments, the donor (D) and acceptor (A) fluorophores are usually attached to the macromolecule of interest via long flexible linkers of up to 15 Å in length. This causes significant uncertainties in quantitative distance measurements and prevents experiments with short distances between the attachment points of the dyes due to possible dye-dye interactions. We present two approaches to overcome the above problems as demonstrated by FRET measurements for a series of dsDNA and dsRNA internally labeled with Alexa488 and Cy5 as D and A dye, respectively. First, we characterize the influence of linker length and flexibility on FRET for different dye linker types (long, intermediate, short) by analyzing fluorescence lifetime and anisotropy decays. For long linkers, we describe a straightforward procedure that allows for very high accuracy of FRET-based structure determination through proper consideration of the position distribution of the dye and of linker dynamics. The position distribution can be quickly calculated with geometric accessible volume (AV) simulations, provided that the local structure of RNA or DNA in the proximity of the dye is known and that the dye diffuses freely in the sterically allowed space. The AV approach provides results similar to molecular dynamics simulations (MD) and is fully consistent with experimental FRET data. In a benchmark study for ds A-RNA, an rmsd value of 1.3 Å is achieved. Considering the case of undefined dye environments or very short DA distances, we introduce short linkers with a propargyl or alkenyl unit for internal labeling of nucleic acids to minimize position uncertainties. Studies by ensemble time correlated single photon counting and single-molecule detection show that the nature of the linker strongly affects the radius of the dye's accessible volume (6-16 Å). For short propargyl linkers, heterogeneous dye environments are observed on the millisecond time scale. A detailed analysis of possible orientation effects (κ(2) problem) indicates that, for short linkers and unknown local environments, additional κ(2)-related uncertainties are clearly outweighed by better defined dye positions.

Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO2) and adsorption of remazol reactive dye

NASA Astrophysics Data System (ADS)

Hasan, Siti Zubaidah; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali

2015-09-01

Nanoporous amorphous-MnO2 was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH3COO)2.4H2O) in 0.1 M KMnO4. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO2 bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO2. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye on 0.2g synthesized nanoporous amorphous-MnO2 showed 99 - 100% decolorization.

Estimation of intra-operator variability in perfusion parameter measurements using DCE-US

PubMed Central

Gauthier, Marianne; Leguerney, Ingrid; Thalmensi, Jessie; Chebil, Mohamed; Parisot, Sarah; Peronneau, Pierre; Roche, Alain; Lassau, Nathalie

2011-01-01

AIM: To investigate intra-operator variability of semi-quantitative perfusion parameters using dynamic contrast-enhanced ultrasonography (DCE-US), following bolus injections of SonoVue®. METHODS: The in vitro experiments were conducted using three in-house sets up based on pumping a fluid through a phantom placed in a water tank. In the in vivo experiments, B16F10 melanoma cells were xenografted to five nude mice. Both in vitro and in vivo, images were acquired following bolus injections of the ultrasound contrast agent SonoVue® (Bracco, Milan, Italy) and using a Toshiba Aplio® ultrasound scanner connected to a 2.9-5.8 MHz linear transducer (PZT, PLT 604AT probe) (Toshiba, Japan) allowing harmonic imaging (“Vascular Recognition Imaging”) involving linear raw data. A mathematical model based on the dye-dilution theory was developed by the Gustave Roussy Institute, Villejuif, France and used to evaluate seven perfusion parameters from time-intensity curves. Intra-operator variability analyses were based on determining perfusion parameter coefficients of variation (CV). RESULTS: In vitro, different volumes of SonoVue® were tested with the three phantoms: intra-operator variability was found to range from 2.33% to 23.72%. In vivo, experiments were performed on tumor tissues and perfusion parameters exhibited values ranging from 1.48% to 29.97%. In addition, the area under the curve (AUC) and the area under the wash-out (AUWO) were two of the parameters of great interest since throughout in vitro and in vivo experiments their variability was lower than 15.79%. CONCLUSION: AUC and AUWO appear to be the most reliable parameters for assessing tumor perfusion using DCE-US as they exhibited the lowest CV values. PMID:21512654

Estimation of intra-operator variability in perfusion parameter measurements using DCE-US.

PubMed

Gauthier, Marianne; Leguerney, Ingrid; Thalmensi, Jessie; Chebil, Mohamed; Parisot, Sarah; Peronneau, Pierre; Roche, Alain; Lassau, Nathalie

2011-03-28

To investigate intra-operator variability of semi-quantitative perfusion parameters using dynamic contrast-enhanced ultrasonography (DCE-US), following bolus injections of SonoVue(®). The in vitro experiments were conducted using three in-house sets up based on pumping a fluid through a phantom placed in a water tank. In the in vivo experiments, B16F10 melanoma cells were xenografted to five nude mice. Both in vitro and in vivo, images were acquired following bolus injections of the ultrasound contrast agent SonoVue(®) (Bracco, Milan, Italy) and using a Toshiba Aplio(®) ultrasound scanner connected to a 2.9-5.8 MHz linear transducer (PZT, PLT 604AT probe) (Toshiba, Japan) allowing harmonic imaging ("Vascular Recognition Imaging") involving linear raw data. A mathematical model based on the dye-dilution theory was developed by the Gustave Roussy Institute, Villejuif, France and used to evaluate seven perfusion parameters from time-intensity curves. Intra-operator variability analyses were based on determining perfusion parameter coefficients of variation (CV). In vitro, different volumes of SonoVue(®) were tested with the three phantoms: intra-operator variability was found to range from 2.33% to 23.72%. In vivo, experiments were performed on tumor tissues and perfusion parameters exhibited values ranging from 1.48% to 29.97%. In addition, the area under the curve (AUC) and the area under the wash-out (AUWO) were two of the parameters of great interest since throughout in vitro and in vivo experiments their variability was lower than 15.79%. AUC and AUWO appear to be the most reliable parameters for assessing tumor perfusion using DCE-US as they exhibited the lowest CV values.

Third-order nonlinear optical properties of organic azo dyes by using strength of nonlinearity parameter and Z-scan technique

NASA Astrophysics Data System (ADS)

Motiei, H.; Jafari, A.; Naderali, R.

2017-02-01

In this paper, two chemically synthesized organic azo dyes, 2-(2,5-Dichloro-phenyazo)-5,5-dimethyl-cyclohexane-1,3-dione (azo dye (i)) and 5,5-Dimethyl-2-tolylazo-cyclohexane-1,3-dione (azo dye (ii)), have been studied from optical Kerr nonlinearity point of view. These materials were characterized by Ultraviolet-visible spectroscopy. Experiments were performed using a continous wave diode-pumped laser at 532 nm wavelength in three intensities of the laser beam. Nonlinear absorption (β), refractive index (n2) and third-order susceptibility (χ (3)) of dyes, were calculated. Nonlinear absorption coefficient of dyes have been calculated from two methods; 1) using theoretical fits and experimental data in the Z-scan technique, 2) using the strength of nonlinearity curves. The values of β obtained from both of the methods were approximately the same. The results demonstrated that azo dye (ii) displays better nonlinearity and has a lower two-photon absorption threshold than azo dye (i). Calculated parameter related to strength of nonlinearity for azo dye (ii) was higher than azo dye (i), It may be due to presence of methyl in azo dye (ii) instead of chlorine in azo dye (i). Furthermore, The measured values of third order susceptibility of azo dyes were from the order of 10-9 esu . These azo dyes can be suitable candidate for optical switching devices.

Defining the local nerve blocks for feline distal thoracic limb surgery: a cadaveric study

PubMed Central

Enomoto, Masataka; Lascelles, B Duncan X; Gerard, Mathew P

2016-01-01

Objectives Though controversial, onychectomy remains a commonly performed distal thoracic limb surgical procedure in cats. Peripheral nerve block techniques have been proposed in cats undergoing onychectomy but evidence of efficacy is lacking. Preliminary tests of the described technique using cadavers resulted in incomplete staining of nerves. The aim of this study was to develop nerve block methods based on cadaveric dissections and test these methods with cadaveric dye injections. Methods Ten pairs of feline thoracic limbs (n = 20) were dissected and superficial branches of the radial nerve (RSbr nn.), median nerve (M n.), dorsal branch of ulnar nerve (UDbr n.), superficial branch of palmar branch of ulnar nerve (UPbrS n.) and deep branch of palmar branch of ulnar nerve (UPbrDp n.) were identified. Based on these dissections, a four-point block was developed and tested using dye injections in another six pairs of feline thoracic limbs (n = 12). Using a 25 G × 5/8 inch needle and 1 ml syringe, 0.07 ml/kg methylene blue was injected at the site of the RSbr nn., 0.04 ml/kg at the injection site of the UDbr n., 0.08 ml/kg at the injection site of the M n. and UPbrS n., and 0.01 ml/kg at the injection site of the UPbrDp n. The length and circumference of each nerve that was stained was measured. Results Positive staining of all nerves was observed in 12/12 limbs. The lengths stained for RSbr nn., M n., UDbr n., UPbrS n. and UPbrDp n. were 34.9 ± 5.3, 26.4 ± 4.8, 29.2 ± 4.0, 39.1 ± 4.3 and 17.5 ± 3.3 mm, respectively. The nerve circumferences stained were 93.8 ± 15.5, 95.8 ± 9.7, 100 ± 0.0, 100 ± 0.0 and 93.8 ± 15.5%, respectively. Conclusions and relevance This described four-point injection method may be an effective perioperative analgesia technique for feline distal thoracic limb procedures. PMID:26250858

Ultrafast and slow charge recombination dynamics of diketopyrrolopyrrole-NiO dye sensitized solar cells.

PubMed

Zhang, Lei; Favereau, Ludovic; Farré, Yoann; Mijangos, Edgar; Pellegrin, Yann; Blart, Errol; Odobel, Fabrice; Hammarström, Leif

2016-07-21

In a photophysical study, two diketopyrrolopyrrole (DPP)-based sensitizers functionalized with 4-thiophenecarboxylic acid as an anchoring group and a bromo (DPPBr) or dicyanovinyl (DPPCN2) group, and a dyad consisting of a DPP unit linked to a naphthalenediimide group (DPP-NDI), were investigated both in solution and grafted on mesoporous NiO films. Femtosecond transient absorption measurements indicate that ultrafast hole injection occurred predominantly on a timescale of ∼200 fs, whereas the subsequent charge recombination occurred on a surprisingly wide range of timescales, from tens of ps to tens of μs; this kinetic heterogeneity is much greater than is typically observed for dye-sensitized TiO2 or ZnO. Also, in contrast to what is typically observed for dye-sensitized TiO2, there was no significant dependence on the excitation power of the recombination kinetics, which can be explained by the hole density being comparatively higher near the valence band of NiO before excitation. The additional acceptor group in DPP-NDI provided a rapid electron shift and stabilized charge separation up to the μs timescale. This enabled efficient (∼95%) regeneration of NDI by a Co(III)(dtb)3 electrolyte (dtb = 4,4'-di-tert-butyl-2,2'-bipyridine), according to transient absorption measurements. The regeneration of DPPBr and DPPCN2 by Co(III)(dtb)3 was instead inefficient, as most recombination for these dyes occurred on the sub-ns timescale. The transient spectroscopy data thus corroborated the trend of the published photovoltaic properties of dye-sensitized solar cells (DSSCs) based on these dyes on mesoporous NiO, and show the potential of a design strategy with a secondary acceptor bound to the dye. The study identifies rapid initial recombination between the dye and NiO as the main obstacle to obtaining high efficiencies in NiO-based DSSCs; these recombination components may be overlooked when studies are conducted using only methods with ns resolution or slower.

Solar H2 evolution in water with modified diketopyrrolopyrrole dyes immobilised on molecular Co and Ni catalyst-TiO2 hybrids.

PubMed

Warnan, Julien; Willkomm, Janina; Ng, Jamues N; Godin, Robert; Prantl, Sebastian; Durrant, James R; Reisner, Erwin

2017-04-01

A series of diketopyrrolopyrrole (DPP) dyes with a terminal phosphonic acid group for attachment to metal oxide surfaces were synthesised and the effect of side chain modification on their properties investigated. The organic photosensitisers feature strong visible light absorption ( λ = 400 to 575 nm) and electrochemical and fluorescence studies revealed that the excited state of all dyes provides sufficient driving force for electron injection into the TiO 2 conduction band. The performance of the DPP chromophores attached to TiO 2 nanoparticles for photocatalytic H 2 evolution with co-immobilised molecular Co and Ni catalysts was subsequently studied, resulting in solar fuel generation with a dye-sensitised semiconductor nanoparticle system suspended in water without precious metal components. The performance of the DPP dyes in photocatalysis did not only depend on electronic parameters, but also on properties of the side chain such as polarity, steric hinderance and hydrophobicity as well as the specific experimental conditions and the nature of the sacrificial electron donor. In an aqueous pH 4.5 ascorbic acid solution with a phosphonated DuBois-type Ni catalyst, a DPP-based turnover number (TON DPP ) of up to 205 was obtained during UV-free simulated solar light irradiation (100 mW cm -2 , AM 1.5G, λ > 420 nm) after 1 day. DPP-sensitised TiO 2 nanoparticles were also successfully used in combination with a hydrogenase or platinum instead of the synthetic H 2 evolution catalysts and the platinum-based system achieved a TON DPP of up to 2660, which significantly outperforms an analogous system using a phosphonated Ru tris(bipyridine) dye (TON Ru = 431). Finally, transient absorption spectroscopy was performed to study interfacial recombination and dye regeneration kinetics revealing that the different performances of the DPP dyes are most likely dictated by the different regeneration efficiencies of the oxidised chromophores.

High efficiency ZnO-based dye-sensitized solar cells with a 1H,1H,2H,2H-perfluorodecyltriethoxysilane chain barrier for cutting on interfacial recombination

NASA Astrophysics Data System (ADS)

Xie, Yahong; Zhou, Xiaofeng; Mi, Hongyu; Ma, Junhong; Yang, Jianya; Cheng, Jian

2018-03-01

Charge recombination at the ZnO photoanode/electrolyte interface is one of the major limitations for high performance dye-sensitized solar cells (DSSCs) toward their theoretical power conversion efficiency (PCE). Here, we proposed an efficient approach for reducing this interfacial losses and consequently facilitating charge transfer by decorating a hydrophobic thin-film on the surface of the dye-coated zinc oxide photoanode via 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) hexane solution immersing. As a result, a high PCE of 8.22% was obtained, which far exceeded the efficiency of 5.40% in a conventional DSSC without PFDTES treatment. Furthermore, PFDTES treatment also largely elongated the lifetime of photogenerated electrons, and maintained a good photo-response at the photoelectrode. This work provides a comprehensive explanation of electron injection, transfer and recombination at the ZnO photoanode/electrolyte interface, and a promising strategy to explore high efficiency ZnO-based DSSCs.

Evans blue dye-enhanced imaging of the brain microvessels using spectral focusing coherent anti-Stokes Raman scattering microscopy

PubMed Central

Lee, Bo-Ram; Joo, Kyung-Il; Choi, Eun Sook; Jahng, Junghoon; Kim, Hyunmin

2017-01-01

We performed dye-enhanced imaging of mouse brain microvessels using spectral focusing coherent anti-Stokes Raman scattering (SF-CARS) microscopy. The resonant signals from C-H stretching in forward CARS usually show high background intensity in tissues, which makes CARS imaging of microvessels difficult. In this study, epi-detection of back-scattered SF-CARS signals showed a negligible background, but the overall intensity of resonant CARS signals was too low to observe the network of brain microvessels. Therefore, Evans blue (EB) dye was used as contrasting agent to enhance the back-scattered SF-CARS signals. Breakdown of brain microvessels by inducing hemorrhage in a mouse was clearly visualized using backward SF-CARS signals, following intravenous injection of EB. The improved visualization of brain microvessels with EB enhanced the sensitivity of SF-CARS, detecting not only the blood vessels themselves but their integrity as well in the brain vasculature. PMID:29049299

Transition metal ferrocenyl dithiocarbamates functionalized dye-sensitized solar cells with hydroxy as an anchoring group

NASA Astrophysics Data System (ADS)

Yadav, Reena; Waghadkar, Yogesh; Kociok-Köhn, Gabriele; Kumar, Abhinav; Rane, Sunit B.; Chauhan, Ratna

2016-12-01

Three new transition-metal dithiocarbamates involving ferrocene (Fc), namely [Co(FcCH2EtOHdtc)3] (Co), [M(FcCH2EtOHdtc)2] M = Ni (Ni), Cu (Cu) (EtOHdtc = N-ethanol dithiocarbamate), have been synthesized and characterized by microanalyses, FTIR, 1H and 13C NMR spectroscopies and single crystal X-ray diffraction technique. The peak broadening in the 1H spectrum of the copper complex indicates the paramagnetic behavior of this compound. The observed single quasi-reversible cyclic voltammograms for the complexes indicate the stabilization of a metal center (except copper) other than Fe in their characteristic oxidation state. These complexes have been used as photo-sensitizer in dye-sensitized solar cells which indicates that Co displays the best photosensitization property with an overall conversion efficiency of 3.25 ± 0.04%. The low cell efficiency of Ni and Cu complexes may be due to slow regeneration of the dye by iodine/iodide redox couple followed by charge injection into TiO2.

Non-invasive in vivo imaging of arthritis in a collagen-induced murine model with phosphatidylserine-binding near-infrared (NIR) dye.

PubMed

Chan, Marion M; Gray, Brian D; Pak, Koon Y; Fong, Dunne

2015-03-09

Development of non-invasive molecular imaging techniques that are based on cellular changes in inflammation has been of active interest for arthritis diagnosis. This technology will allow real-time detection of tissue damage and facilitate earlier treatment of the disease, thus representing an improvement over X-rays, which detect bone damage at the advanced stage. Tracing apoptosis, an event occurring in inflammation, has been a strategy used. PSVue 794 is a low-molecular-weight, near-infrared (NIR)-emitting complex of bis(zinc2+-dipicolylamine) (Zn-DPA) that binds to phosphatidylserine (PS), a plasma membrane anionic phospholipid that becomes flipped externally upon cell death by apoptosis. In this study, we evaluated the capacity of PSVue 794 to act as an in vivo probe for non-invasive molecular imaging assessment of rheumatoid arthritis (RA) via metabolic function in murine collagen-induced arthritis, a widely adopted animal model for RA. Male DBA/1 strain mice were treated twice with chicken collagen type II in Freund's adjuvant. Their arthritis development was determined by measuring footpad thickness and confirmed with X-ray analysis and histology. In vivo imaging was performed with the NIR dye and the LI-COR Odyssey Image System. The level of emission was compared among mice with different disease severity, non-arthritic mice and arthritic mice injected with a control dye without the Zn-DPA targeting moiety. Fluorescent emission correlated reliably with the degree of footpad swelling and the manifestation of arthritis. Ex vivo examination showed emission was from the joint. Specificity of binding was confirmed by the lack of emission when arthritic mice were given the control dye. Furthermore, the PS-binding protein annexin V displaced the NIR dye from binding, and the difference in emission was numerically measurable on a scale. This report introduces an economical alternative method for assessing arthritis non-invasively in murine models. Inflammation in feet and ankles can be measured longitudinally using the PSVue 794 probe for cell death and with a commonly available multipurpose imager. This technique provides metabolic and functional information that anatomical measurement of footpad swelling or visual determination of arthritic index cannot. It also may decrease the number of animals required per experiment because tissue damage will not necessarily require evaluation by harvesting joints for histology.

Response surface methodology for optimization of medium for decolorization of textile dye Direct Black 22 by a novel bacterial consortium.

PubMed

Mohana, Sarayu; Shrivastava, Shalini; Divecha, Jyoti; Madamwar, Datta

2008-02-01

Decolorization and degradation of polyazo dye Direct Black 22 was carried out by distillery spent wash degrading mixed bacterial consortium, DMC. Response surface methodology (RSM) involving a central composite design (CCD) in four factors was successfully employed for the study and optimization of decolorization process. The hyper activities and interactions between glucose concentration, yeast extract concentration, dye concentration and inoculum size on dye decolorization were investigated and modeled. Under optimized conditions the bacterial consortium was able to decolorize the dye almost completely (>91%) within 12h. Bacterial consortium was able to decolorize 10 different azo dyes. The optimum combination of the four variables predicted through RSM was confirmed through confirmatory experiments and hence this bacterial consortium holds potential for the treatment of industrial waste water. Dye degradation products obtained during the course of decolorization were analyzed by HPTLC.

Biodegradation of Methylene Blue Dye by Sequential Treatment Using Anaerobic Hybrid Reactor and Submerged Aerobic Fixed Film Bioreactor

NASA Astrophysics Data System (ADS)

Farooqi, Izharul H.; Basheer, Farrukh; Tiwari, Pradeepika

2017-12-01

Laboratory scale experiments were carried out to access the feasibility of sequential anaerobic/aerobic biological treatment for the biodegradation of Methylene Blue (MB) dye. Anaerobic studies were performed using anaerobic hybrid reactor (consisting of UASB and Anaerobic filter) whereas submerged aerobic fixed film reactor was used as aerobic reactor. Degradation of MB dye was attempted using neutralized acetic acid (1000 mg/L) as co-substrate. MB dye concentration was stepwise increased from 10 to 70 mg/L after reaching steady state in each dye concentration. Such a gradual increase in the dye concentration helps in the proper acclimatization of the sludge to dyes thereby avoiding the possible inhibitory effects to biological activities at high dye concentrations. The overall treatment efficiency of MB through sequential anaerobic-aerobic reactor operation was 90% at maximum attempted dye concentration of 70 mg/L. The effluent from anaerobic reactor was analysed for intermediate biodegradation products through HPLC. It was observed that catechol, quinone, amino pyrine, 1,4 diamino benzene were present. However they were absent in final effluent.

Crucial role of nuclear dynamics for electron injection in a dye–semiconductor complex

DOE PAGES

Monti, Adriano; Negre, Christian F. A.; Batista, Victor S.; ...

2015-06-05

In this study, we investigate the electron injection from a terrylene-based chromophore to the TiO 2 semiconductor bridged by a recently proposed phenyl-amide-phenyl molecular rectifier. The mechanism of electron transfer is studied by means of quantum dynamics simulations using an extended Hückel Hamiltonian. It is found that the inclusion of the nuclear motion is necessary to observe the photoinduced electron transfer. In particular, the fluctuations of the dihedral angle between the terrylene and the phenyl ring modulate the localization and thus the electronic coupling between the donor and acceptor states involved in the injection process. The electron propagation shows characteristicmore » oscillatory features that correlate with interatomic distance fluctuations in the bridge, which are associated with the vibrational modes driving the process. The understanding of such effects is important for the design of functional dyes with optimal injection and rectification properties.« less

Determination of stream reaeration coefficients by use of tracers

USGS Publications Warehouse

Kilpatrick, F.A.; Rathbun, R.E.; Yotsukura, N.; Parker, G.W.; DeLong, L.L.

1987-01-01

Stream reaeration is the physical absorption of oxygen from the atmosphere by a flowing stream. This is the primary process by which a stream replenishes the oxygen consumed in the biodegradation of organic wastes.Prior to 1965, reaeration rate coefficients could be estimated only by indirect methods. In 1965, a direct method of measuring stream reaeration coefficients was developed in which a radioactive tracer gas was injected into a stream--the tracer gas being desorbed from the stream inversely to how oxygen would be absorbed. The technique has since been modified by substituting hydrocarbon gases for the radioactive tracer gas.This manual describes the slug-injection and constant-rate injection methods of performing gas-tracer desorption measurements. Emphasis is on the use of rhodamine WT dye as a relatively conservative tracer and propane as the nonconservative gas tracer, on planning field tests, methods of injection, sampling and analysis, and computational techniques to compute desorption and reaeration coefficients.

Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

USGS Publications Warehouse

Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

1988-01-01

The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

CISDE Experiment: Nearshore-Estuarine Connectivity & Dispersion

NASA Astrophysics Data System (ADS)

Giddings, S. N.; Feddersen, F.; Harvey, M.; Gilroy, A. R.; Crooks, J.; McCullough, J.; Lorda, J.; Grimes, D. J.; Pawlak, G. R.

2016-02-01

As part of the CSIDE, Cross Surfzone/Inner-shelf Dye Exchange experiment, nearby shallow estuary measurements were made in addition to the surfzone and inner-shelf measurements, providing an integrated view into the estuary, surfzone, and shelf system. The CSIDE experiment was designed to look at the dispersion of dye as a proxy for dispersion of waterborne constituents such as pollutants, larvae, sediment, etc. along the coast and across the surfzone to a stratified inner-shelf. The Tijuana River Estuary, a shallow estuary with extensive intertidal regions and marsh, is sometimes the source of harmful contaminants that lead to beach closures in the CSIDE experiment region. However, at other times, the estuary may also act as a sink depending upon the freshwater conditions upstream. During this experiment, we installed temperature and salinity sensors, velocimeters, and fluorometers (measuring both turbidity and the dye concentration) in the two main arms of the Tijuana River Estuary to assess the connectivity between the surfzone and the estuary as well as the in-estuary dispersion.

Laser pulse control of ultrafast heterogeneous electron transfer: a computational study.

PubMed

Wang, Luxia; May, Volkhard

2004-10-22

Laser pulse control of the photoinduced 90 fs charge injection from perylene into the conduction band of TiO2 is studied theoretically. The approach accounts for the electronic-ground state of the dye, the first excited state, the ionized state formed after charge injection, and the continuum of the electronic states in the conduction band, all defined vs a single reaction coordinate. To address different control tasks optimal control theory is combined with a full quantum dynamical description of the electron-vibrational motion accompanying the charge injection process. First it is proved in which way the charge injection time can be changed by tailored laser pulses. In a second step a pump-dump scheme from the perylene ground state to the first excited electronic state and back to the ground state is discussed. Because of the strong coupling of the excited perylene state to the band continuum of TiO2 this control task is more suited to an experimental test than the direct control of the charge injection.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karingithi, C.W.

Tracer and injection tests were performed in the Olkaria North East Field with the objective to reduce uncertainty in the engineering design and to determine the suitability of well OW-704 as a re-injection well for the waste brine from the steam field during production. An organic dye (sodium fluorescein) was injected into well OW-704 as a slug. The tracer returns were observed in well OW-M2 which is 580 m deep, 620 m from well OW-704 and well OW-716 which is 900 m from well OW-704. The other wells on discharge, OW-714, and OW-725 did not show any tracer returns. However,more » other chemical constituents suggested., that well OW-716 experienced a chemical breakthrough earlier than OW-M2. Tracer return velocities of 0.31 m/hr and 1.3 m/hr were observed. Results of the tracer and injection tests indicate that OW-704 may be used as a re-injection well provided a close monitoring program is put in place.« less

Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO{sub 2}) and adsorption of remazol reactive dye

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasan, Siti Zubaidah; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali, E-mail: rozali@ukm.edu.my

2015-09-25

Nanoporous amorphous-MnO{sub 2} was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH{sub 3}COO){sub 2}.4H{sub 2}O) in 0.1 M KMnO{sub 4}. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO{sub 2} bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO{sub 2}. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye onmore » 0.2g synthesized nanoporous amorphous-MnO{sub 2} showed 99 – 100% decolorization.« less

Axillary lymph node recurrence after sentinel lymph node biopsy performed using a combination of indocyanine green fluorescence and the blue dye method in early breast cancer.

PubMed

Inoue, Tomoo; Nishi, Toshio; Nakano, Yoshiaki; Nishimae, Ayaka; Sawai, Yuka; Yamasaki, Masaru; Inaji, Hideo

2016-03-01

There is limited information on indocyanine green (ICG) fluorescence and blue dye for detecting sentinel lymph node (SLN) in early breast cancer. A retrospective study was conducted to assess the feasibility of an SLN biopsy using the combination of ICG fluorescence and the blue dye method. Seven hundred and fourteen patients with clinically node-negative breast cancer were included in this study. They underwent SLN biopsy using a combination of ICG fluorescence and the blue dye method from March 2007 to February 2014. The ICG (a fluorescence-emitting source) and patent blue (the blue dye) were injected into the patients' subareolar region. The removed lymph nodes that had ICG fluorescence and/or blue dye uptake were defined as SLNs. The results of the SLN biopsies and follow-up results of patients who underwent SLN biopsy alone were investigated. In 711 out of 714 patients, SLNs were identified by a combination of ICG fluorescence and the blue dye method (detection rate, 99.6 %). The average number of SLNs was 2.4 (range 1-7), and the average number of resected swollen para-SLNs was 0.4 (range 0-5). Ninety-nine patients with an SLN and/or para-SLN involvement during the intraoperative pathological diagnosis underwent axillary lymph node resection (ALND). In addition, two of three patients whose SLN was not identified also underwent ALND. In 46 of 101 patients with an ALND, non-SLN involvement was not found. Follow-up results were analyzed in 464 patients with invasive carcinoma excluding those with ductal carcinoma in situ (n = 148) and those who underwent ALND (n = 101). During the follow-up period (range 4.4-87.7 months; median, 38 months), two patients (0.4 %) developed axillary lymph node recurrence. They were successfully salvaged, and to date, no further locoregional recurrence has been observed. A high rate of SLN detection and low rate of axillary lymph node recurrence were confirmed by an SLN biopsy using a combination of ICG fluorescence and the blue dye method. Therefore, it is suggested that this method may replace the combination of dye and radioisotope methods.

Using Smoke Injection in Drains to Identify Potential Preferential Pathways in a Drained Arable Field

NASA Astrophysics Data System (ADS)

Nielsen, M. H.; Petersen, C. T.; Hansen, S.

2014-12-01

Macropores forming a continuous pathway between the soil surface and subsurface drains favour the transport of many contaminants from agricultural fields to surface waters. The smoke injection method presented by Shipitalo and Gibbs (2000) used for demonstrating and quantifying such pathways has been further developed and used on a drained Danish sandy loam. In order to identify the preferential pathways to drains, smoke was injected in three 1.15 m deep tile drains (total drain length 93 m), and smoke emitting macropores (SEMP) at the soil surface were counted and characterized as producing either strong or weak plumes compared to reference plumes from 3 and 6 mm wide tubes. In the two situations investigated in the present study - an early spring and an autumn situation, smoke only penetrated the soil surface layer via earthworm burrows located in a 1.0 m wide belt directly above the drain lines. However, it is known from previous studies that desiccation fractures in a dry summer situation also can contribute to the smoke pattern. The distance between SEMP measured along the drain lines was on average 0.46 m whereas the average spacing between SEMP with strong plumes was 2.3 m. Ponded water was applied in 6 cm wide rings placed above 52 burrows including 17 reference burrows which did not emit smoke. Thirteen pathways in the soil were examined using dye tracer and profile excavation. SEMP with strong plumes marked the entrance of highly efficient transport pathways conducting surface applied water and dye tracer into the drain. However, no single burrow was traced all the way from the surface into the drain, the dye patterns branched off in a network of other macropores. Water infiltration rates were significantly higher (P < 0.05) in SEMP with strong plumes (average rate: 247 mL min-1 n = 19) compared to SEMP with weak plumes (average rate: 87 mL min-1 n = 16) and no plumes (average rate: 56 mL min-1 n = 17). The results suggest that the smoke injection method is useful for identification of potentially efficient pathways for surface applied contaminants to drains and surface waters, pathways being associated primarily with unevenly distributed SEMP producing strong smoke plumes.

The effect of the hole injection layer on the performance of single layer organic light-emitting diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wenjin, Zeng; Ran, Bi; Hongmei, Zhang, E-mail: iamhmzhang@njupt.edu.cn, E-mail: iamwhuang@njupt.edu.cn

2014-12-14

Efficient single-layer organic light-emitting diodes (OLEDs) were reported based on a green fluorescent dye 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7–tetramethyl-1H,5H,11H-(1) benzopyropyrano (6,7-8-I,j)quinolizin-11-one (C545T). Herein, poly(3,4-ethylenedioxy thiophene) poly(styrene sulfonate) were, respectively, applied as the injection layer for comparison. The hole transport properties of the emission layer with different hole injection materials are well investigated via current-voltage measurement. It was clearly found that the hole injection layers (HILs) play an important role in the adjustment of the electron/hole injection to attain transport balance of charge carriers in the single emission layer of OLEDs with electron-transporting host. The layer of tris-(8-hydroxyquinoline) aluminum played a dual role of hostmore » and electron-transporting materials within the emission layer. Therefore, appropriate selection of hole injection layer is a key factor to achieve high efficiency OLEDs with single emission layer.« less

The revascularization of pedicle skin flaps in pigs: a functional and morphologic study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, C.M.

1982-10-01

Functional and morphologic changes occurring during the revascularization of pedicle flaps have been investigated in the skin of pigs. The skin flaps, 16 cm long by 4 cm wide, were based on a row of segmental vessels arising from the internal mammary artery. Comparative measurements were made in flapped and normal skin. The inherent blood supply in the pedicle of the flap was unable to maintain the whole of the flap in a viable state. Flap viability was ascertained at surgery by the use of the intravital dye Disulphine blue. Injections of the dye after surgery gave a less accuratemore » prediction of viability than when dye was injected prior to surgery. Revascularization between the flap and surrounding skin was evident 3 to 4 days postoperatively at the distal, most hypoxic part of the viable flap. The whole flap had a collateral vascular supply 7 to 10 days after surgery. Isotope clearance studies showed that the greatest functional changes occurred in the distal third of the viable flap, where, after initially slowing, the clearance rate became faster than in normal skin (day 5). Potassium extraction studies indicated similar changes. However, an increase in the red-cell volume on day 1 suggested that vascular shunting was occurring. The results of the morphologic studies indicated a correlation between the number of blood vessels per unit area, the thickness of the dermis, and the recorded functional changes. Seven days after surgery, when isotope clearance rates were very rapid, there was a significant increase in the vascular density and dermal thickness.« less

A Simple Strategy in Avulsion Flap Injury: Prediction of Flap Viability Using Wood's Lamp Illumination and Resurfacing with a Full-thickness Skin Graft.

PubMed

Lim, Hyoseob; Han, Dae Hee; Lee, Il Jae; Park, Myong Chul

2014-03-01

Extensive degloving injuries of the extremities usually result in necrosis of the flap, necessitating comprehensive skin grafting. Provided there is a sufficient tool to evaluate flap viability, full-thickness skin can be used from a nonviable avulsed flap. We used a Wood's lamp to determine the viability of avulsed flaps in the operation field after intravenous injection of fluorescein dye. We experienced 13 cases during 16 months. Fifteen minutes after the intravenous injection of fluorescein dye, the avulsed skin flaps were examined and non-fluorescent areas were marked under Wood's lamp illumination. The marked area was defatted for full-thickness skin grafting. The fluorescent areas were sutured directly without tension. The non-fluorescent areas were covered by defatted skin. Several days later, there was soft tissue necrosis within the flap area. We measured necrotic area and revised the flap. Among all the cases, necrotic area was 21.3% of the total avulsed area. However, if we exclude three cases, one of a carelessly managed patient and two cases of the flaps were inappropriately applied, good results were obtained, with a necrotic area of only 8.4%. Eight patients needed split-thickness skin grafts, and heel pad reconstruction was performed with free flap. A full-thickness skin graft from an avulsed flap is a good method for addressing aesthetic concerns without producing donor site morbidity. Fluorescein dye is a useful, simple, and cost-effective tool for evaluating flap viability. Avulsed flap injuries can be managed well with Wood's lamp illumination and a full-thickness skin graft.

Validation of a dye stain assay for vaginally inserted HEC-filled microbicide applicators

PubMed Central

Katzen, Lauren L.; Fernández-Romero, José A.; Sarna, Avina; Murugavel, Kailapuri G.; Gawarecki, Daniel; Zydowsky, Thomas M.; Mensch, Barbara S.

2011-01-01

Background The reliability and validity of self-reports of vaginal microbicide use are questionable given the explicit understanding that participants are expected to comply with study protocols. Our objective was to optimize the Population Council's previously validated dye stain assay (DSA) and related procedures, and establish predictive values for the DSA's ability to identify vaginally inserted single-use, low-density polyethylene microbicide applicators filled with hydroxyethylcellulose gel. Methods Applicators, inserted by 252 female sex workers enrolled in a microbicide feasibility study in Southern India, served as positive controls for optimization and validation experiments. Prior to validation, optimal dye concentration and staining time were ascertained. Three validation experiments were conducted to determine sensitivity, specificity, negative predictive values and positive predictive values. Results The dye concentration of 0.05% (w/v) FD&C Blue No. 1 Granular Food Dye and staining time of five seconds were determined to be optimal and were used for the three validation experiments. There were a total of 1,848 possible applicator readings across validation experiments; 1,703 (92.2%) applicator readings were correct. On average, the DSA performed with 90.6% sensitivity, 93.9% specificity, and had a negative predictive value of 93.8% and a positive predictive value of 91.0%. No statistically significant differences between experiments were noted. Conclusions The DSA was optimized and successfully validated for use with single-use, low-density polyethylene applicators filled with hydroxyethylcellulose (HEC) gel. We recommend including the DSA in future microbicide trials involving vaginal gels in order to identify participants who have low adherence to dosing regimens. In doing so, we can develop strategies to improve adherence as well as investigate the association between product use and efficacy. PMID:21992983

Dye-Sensitized Approaches to Photovoltaics

NASA Astrophysics Data System (ADS)

Grätzel, Michael

2008-03-01

Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely reaction of such a hole is the photocorrosion of the semiconductor itself. However, only relatively narrow band-gap materials have an effective optical absorption through the visible spectrum, towards and into the infra-red. Materials with an optimal band-gap match to the solar spectrum, of the order of 1.5eV, are therefore electrochemically unstable. A stable photoelectrochemical cell, without some process of optical sensitization, and necessarily using a wide-gap semiconductor is sensitive only to the ultra-violet limit of the visible spectrum. Over recent years a suitable combination of semiconductor and sensitizer has been identified and optimized, so that now a solar spectrum conversion efficiency of over 11% has been verified in a sensitized photoelectrochemical device. One key to such an efficient system is the suppression of recombination losses. When the excited dye relaxes by electron loss, the separated charge carriers find themselves on opposite sides of a phase barrier -- the electron within the solid-state semiconductor, the positive charge externally, in association with the dye molecule. There is no valence---band involvement in the process, so the system represents a majority-carrier device, avoiding one of the major loss mechanisms in conventional photovoltaics. In consequence also a highly-disordered, even porous, semiconductor structure is acceptable, enabling surface adsorption of a sufficient concentration of the dye to permit total optical absorption of incident light of photon energy greater than the HOMO-LUMO gap of the dye molecule. The accepted wide-band semiconductor for photoelectrochemical applications is titanium dioxide in the anatase crystal structure. The size of the nanocrystals making up the semiconductor photoanode can be determined by hydrothermal processing of a precursor sol, and the film can be deposited on a transparent conducting oxide (TCO) substrate by any convenient thin-film process such as screen printing or tape casting. The preferred dye system is inspired by the natural processes involving chlorophyll, the coloring material in plants on which all earthly life depends. Chlorophyll is an organometallic dye, with a metal ion, Mg, within a porphyrin cage of nitrogen atoms. The synthetic chemist of course can select any convenient metal within the periodic table, and experience shows that ruthenium has the optimal properties expected. A ruthenium-pyridyl complex provides the chromophore of the dye, with the HOMO-LUMO gap, and thence the absorption spectrum bring modified by substitution with thiocyanide groups. Chemisorptive attachment of the dye to the metal oxide surface is obtained by carboxyl groups attached to the pyridyl components. The energetics of the dye is such that the LUMO level is just above the conduction band edge of the semiconductor, enabling relaxation by electron injection as required. A satisfactory electroactive dye structure, with good attachment properties and a wide optical absorption spectrum is therefore a sophisticated molecular engineering product. The electrolyte is also an optimized electrochemical system. The basic redox behavior is provided by the iodine/iodide system, with the advantage that the ions, both oxidized and reduced are relatively small, and therefore mobile in the supporting electrolyte. Energy losses due to slow diffusion are minimized. Early experiments used aqueous electrolytes, though with limited cell lifetime due to hydrolysis of the chemisorptive dye---semiconductor bond. A wide range of organic systems were therefore investigated, with the present favored formulation being based on imidazole salts. These have the additional advantage of low vapor pressure, very necessary as the photoactive sites under mid---day sun illumination may reach 80 C or higher. Low losses at the cathode counterelectrode are also a requirement for cell efficiency. The cathode is not necessarily transparent, and prototype cells on thin metal foils have been produced. However a TCO on glass or polymer counterelectrode is widely used. In either case suitable electrocatalytic behavior is required and frequently a nanodispersed Pt precipitated from haxachloride solution is employed. It is by now evident that the achievement of an industrially-competitive sensitized photoelectrochemical solar cell is the result of the optimization of several components, associated obviously with their effective synergy. Each change of a single component has repercussions on the choice and performance of others. However as already mentioned an efficiency of over 11% has now been certified, and a stability of over 14,000 hours under accelerated testing with continuous simulated AM1.5 illumination was recently reported. In consequence there is increasing confidence on the part of industry. Several licensees of EPFL patents on dye---sensitized photovoltaic systems are now preparing for large-scale production. G24 Innovations PLC in Wales is commissioning a manufacturing plant, and Dyesol PLC in Australia is making available the required materials on an industrial scale. In conclusion, then, it can be stated that the DSC system is much more than a fascinating scientific artifact illustrating charge-transfer mechanisms at electrochemical interfaces; an efficiency and reliability with industrial credibility have been demonstrated and verified, and a significant role in competition with other photosystems can be foreseen.

Antigen-induced inhibition of autoimmune response to rat male accessory glands: distinct characteristics of I-A- and I-E-positive peritoneal cells.

PubMed

Rivero, V E; Ferro, M E; Romero-Piffiguer, M; Correa, S; Yranzo-Volonté, N; Riera, C M

1991-05-01

The present report describes different aspects of two populations of peritoneal cells (PC) obtained from rats injected i.p. 2 h or 24 h previously with a suppressor dose of a purified fraction (FI) of rat male accessory glands (RAG) (FI-PC2h and FI-PC24h, respectively). The FI-PC2h, which are mainly I-E (OX17) positive and can suppress the autoimmune response to RAG autoantigens, have an elevated phagocytic activity against Candida albicans and capacity to reduce the dye nitroblue tetrazolium. In contrast, FI-PC24h, which are mainly I-A (OX6) positive and can potentiate the autoimmunity to RAG autoantigens, have a diminished capacity to reduce the dye and a diminished phagocytic activity. Moreover, the Toxoplasma gondii appear to have a different effect on both populations. The parasites can invade FI-PC2h while FI-PC24h offer resistance to T. gondii aggression. FI-PC2h cultured during 22 h (FI-PC2-24h in vitro), or PC obtained from syngeneic recipients injected i.p. 22 h previously with FI-PC2h (FI-PC2-24h in vivo) show, as FI-PC2h, an increase of the I-E+ cells and capacity to induce suppression of the delayed-type hypersensitivity response to RAG autoantigens when they are injected to syngeneic rats 10 and 3 days prior to the immunization with chemically modified (diazotized arsanilic and sulfanilic acid) RAG in complete Freund's adjuvant. The PC obtained 24 h after injection of irradiated rats with N-PC plus FI show an increase of I-E+ cells whereas an enhancement of I-A+ cells can be observed when the PC are obtained 24 h after injection of irradiated and bone marrow-reconstituted rats with N-PC plus FI. These findings appear to indicate that FI-PC2h and FI-PC24h are functionally different and that the population obtained 24 h after injection of FI of RAG could not originate from either the population present 2 h after injection of FI of RAG injection nor from normal PC. They appear to require bone marrow precursors.

Mast cell activation by group A streptococcal polysaccharide in the rat and its role in experimental arthritis.

PubMed Central

Dalldorf, F. G.; Anderle, S. K.; Brown, R. R.; Schwab, J. H.

1988-01-01

Acute edematous responses were induced in Sprague-Dawley rats by the intravenous injection of group-specific polysaccharide (PS) isolated from group A streptococci. Thirty minutes after the intravenous injection of PS there was marked degranulation of subcutaneous and periarticular mast cells in all 4 feet, carbon particle labeling of adjacent venules, and an 8-fold increase in Evans blue dye content of the extremities. This acute reaction to PS was completely blocked by pretreatment with compound 48/80, but the polyarticular relapsing arthritis following the systemic injection of an arthropathic dose of streptococcal cell wall fragments containing large, covalently bound peptidoglycan-polysaccharide (PG-PS) was not blocked. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:3041843

Synthesis and Characterization of Organic Dyes Containing Various Donors and Acceptors

PubMed Central

Wu, Tzi-Yi; Tsao, Ming-Hsiu; Chen, Fu-Lin; Su, Shyh-Gang; Chang, Cheng-Wen; Wang, Hong-Paul; Lin, Yuan-Chung; Ou-Yang, Wen-Chung; Sun, I-Wen

2010-01-01

New organic dyes comprising carbazole, iminodibenzyl, or phenothiazine moieties, respectively, as the electron donors, and cyanoacetic acid or acrylic acid moieties as the electron acceptors/anchoring groups were synthesized and characterized. The influence of heteroatoms on carbazole, iminodibenzyl and phenothiazine donors, and cyano-substitution on the acid acceptor is evidenced by spectral, electrochemical, photovoltaic experiments, and density functional theory calculations. The phenothiazine dyes show solar-energy-to-electricity conversion efficiency (η) of 3.46–5.53%, whereas carbazole and iminodibenzyl dyes show η of 2.43% and 3.49%, respectively. PMID:20162019

Sedimentation from Particle-Laden Plumes in Stratified Fluid

NASA Astrophysics Data System (ADS)

Sutherland, Bruce; Hong, Youn Sub

2015-11-01

Laboratory experiments are performed in which a mixture of particles, water and a small amount of dye is continuously injected upwards from a localized source into a uniformly stratified ambient. The particle-fluid mixture initially rises as a forced plume (which in most cases is buoyant, though in some cases due to high particle concentration is negative-buoyant at the source), reaches a maximum height, collapses upon itself and then spreads as a radial intrusion. The particles are observed to rain out of the descending intrusion and settle upon the floor of the tank. Using light attenuation, the depth of the particle mound is measured after the experiment has run for a fixed amount of time. In most experiments the distribution of particles is found to be approximately axisymmetric about the source with a near Gaussian structure for height as a function of radius. The results are compared with a code that combines classical plume theory with an adaptation to stratified fluids of the theory of Carey, Sigurdsson and Sparks (JGR, 1988) for the spread and fall of particles from a particle-laden plume impacting a rigid ceiling. Re-entrainment of particles into the plume is also taken into account.

Effect of carbon nano tube working electrode thickness on charge transport kinetics and photo-electrochemical characteristics of dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Gacemi, Yahia; Cheknane, Ali; Hilal, Hikmat S.

2018-02-01

Physiochemical processes at the photo-electrode and the counter electrode of dye sensitized solar cells (DSSCs) involving having carbon nanotubes (CNTs) instead of the TiO2 layer, within the working electrode, are simulated in this work. Attention is paid to find the effect of CNT layer thickness on photo-electrochemical (PEC) characteristics of the CNT-DSSCs. Comparison with other conventional TiO2-DSSC systems, taking into account the working electrode film thickness, is also described here. To achieve these goals, a model is presented to explain charge transport and electron recombination which involve electron photo-excitation in dye molecules, injection of electrons from the excited dye to CNT working electrode conduction band, diffusion of electrons inside the CNT electrode, charge transfer between oxidized dye and (I-) and recombination of electrons. The simulation is based on solving non-linear equations using the Newton-Raphson numerical method. This concept is proposed for modelling numerical Faradaic impedance at the photo-electrode and the platinum counter electrode. It then simulates the cell impedance spectrum describing the locus of the three semicircles in the Nyquist diagram. The transient equivalent circuit model is also presented based on optimizing current-voltage curves of CNT-DSSCs so as to optimize the fill factor (FF) and conversion efficiency (η). The results show that the simulated characteristics of CNT-DSSCs, with different active CNT layer thicknesses, are superior to conventional TiO2-DSSCs.

A Simplified Undergraduate Laboratory Experiment to Evaluate the Effect of the Ionic Strength on the Equilibrium Concentration Quotient of the Bromcresol Green Dye

ERIC Educational Resources Information Center

Rodriguez, Hernan B.; Mirenda, Martin

2012-01-01

A modified laboratory experiment for undergraduate students is presented to evaluate the effects of the ionic strength, "I", on the equilibrium concentration quotient, K[subscript c], of the acid-base indicator bromcresol green (BCG). The two-step deprotonation of the acidic form of the dye (sultone form), as it is dissolved in water, yields…

Water Tunnel Flow Visualization Study Through Poststall of 12 Novel Planform Shapes

NASA Technical Reports Server (NTRS)

Gatlin, Gregory M.; Neuhart, Dan H.

1996-01-01

To determine the flow field characteristics of 12 planform geometries, a flow visualization investigation was conducted in the Langley 16- by 24-Inch Water Tunnel. Concepts studied included flat plate representations of diamond wings, twin bodies, double wings, cutout wing configurations, and serrated forebodies. The off-surface flow patterns were identified by injecting colored dyes from the model surface into the free-stream flow. These dyes generally were injected so that the localized vortical flow patterns were visualized. Photographs were obtained for angles of attack ranging from 10' to 50', and all investigations were conducted at a test section speed of 0.25 ft per sec. Results from the investigation indicate that the formation of strong vortices on highly swept forebodies can improve poststall lift characteristics; however, the asymmetric bursting of these vortices could produce substantial control problems. A wing cutout was found to significantly alter the position of the forebody vortex on the wing by shifting the vortex inboard. Serrated forebodies were found to effectively generate multiple vortices over the configuration. Vortices from 65' swept forebody serrations tended to roll together, while vortices from 40' swept serrations were more effective in generating additional lift caused by their more independent nature.

Delayed near-infrared analysis permits visualization of rodent retinal pigment epithelium layer in vivo

NASA Astrophysics Data System (ADS)

Pankova, Natalie; Zhao, Xu; Liang, Huiyuan; Baek, David Sung Hyeon; Wang, Hai; Boyd, Shelley

2014-07-01

Patches of atrophy of the retinal pigment epithelium (RPE) have not been described in rodent models of retinal degeneration, as they have the clinical setting using fundus autofluorescence. We hypothesize that prelabeling the RPE would increase contrast and allow for improved visualization of RPE loss in vivo. Here, we demonstrate a new technique termed "delayed near-infrared analysis (DNIRA)" that permits ready detection of rat RPE, using optical imaging in the near-infrared (IR) spectrum with aid of indocyanine green (ICG) dye. Using DNIRA, we demonstrate a fluorescent RPE signal that is detected using confocal scanning laser ophthalmoscopy up to 28 days following ICG injection. This signal is apparent only after ICG injection, is dose dependent, requires the presence of the ICG filters (795/810 nm excitation/emission), does not appear in the IR reflectance channel, and is eliminated in the presence of sodium iodate, a toxin that causes RPE loss. Rat RPE explants confirm internalization of ICG dye. Together with normal retinal electrophysiology, these findings demonstrate that DNIRA is a new and safe noninvasive optical imaging technique for in vivo visualization of the RPE in models of retinal disease.

Visible Light Driven Benzyl Alcohol Dehydrogenation in a Dye-Sensitized Photoelectrosynthesis Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Wenjing; Vannucci, Aaron K.; Farnum, Byron H.

2014-06-27

Light-driven dehydrogenation of benzyl alcohol (BnOH) to benzaldehyde and hydrogen has been shown to occur in a dye-sensitized photoelectrosynthesis cell (DSPEC). In the DSPEC, the photoanode consists of mesoporous films of TiO2 nanoparticles or of core/shell nanoparticles with tin-doped In2O3 nanoparticle (nanoITO) cores and thin layers of TiO2 deposited by atomic layer deposition (nanoITO/TiO2). Metal oxide surfaces were coderivatized with both a ruthenium polypyridyl chromophore in excess and an oxidation catalyst. Chromophore excitation and electron injection were followed by cross-surface electron-transfer activation of the catalyst to RuIV=O2+, which then oxidizes benzyl alcohol to benzaldehyde. The injected electrons are transferred tomore » a Pt electrode for H2 production. The nanoITO/TiO2 core/shell structure causes a decrease of up to 2 orders of magnitude in back electron-transfer rate compared to TiO2. At the optimized shell thickness, sustained absorbed photon to current efficiency of 3.7% was achieved for BnOH dehydrogenation, an enhancement of ~10 compared to TiO2.« less

Water Photo-oxidation Initiated by Surface-Bound Organic Chromophores.

PubMed

Eberhart, Michael S; Wang, Degao; Sampaio, Renato N; Marquard, Seth L; Shan, Bing; Brennaman, M Kyle; Meyer, Gerald J; Dares, Christopher; Meyer, Thomas J

2017-11-15

Organic chromophores can be synthesized by established methods and offer an opportunity to expand overall solar spectrum utilization for dye-sensitized photoelectrosynthesis cells. However, there are complications in the use of organic chromophores arising from the instability of their oxidized forms, the inability of their oxidized forms to activate a water oxidation catalyst, or the absence of a sufficiently reducing excited state for electron injection into appropriate semiconductors. Three new triarylamine donor-acceptor organic dyes have been investigated here for visible-light-driven water oxidation. They offer highly oxidizing potentials (>1 V vs NHE in aqueous solution) that are sufficient to drive a water oxidation catalyst and excited-state potentials (∼-1.2 V vs NHE) sufficient to inject into TiO 2 . The oxidized form of one of the chromophores is sufficiently stable to exhibit reversible electrochemistry in aqueous solution. The chromophores also have favorable photophysics. Visible-light-driven oxygen production by an organic chromophore for up to 1 h of operation has been demonstrated with reasonable faradaic efficiencies for measured O 2 production. The properties of organic chromophores necessary for successfully driving water oxidation in a light-driven system are explored along with strategies for improving device performance.

Femtosecond Fluorescence Upconversion Study of a Naphthalimide-Bithiophene-Triphenylamine Push-Pull Dye in Solution.

PubMed

Maffeis, Valentin; Brisse, Romain; Labet, Vanessa; Jousselme, Bruno; Gustavsson, Thomas

2018-06-13

There is a high interest in the development of new push-pull dyes for the use in dye sensitized solar cells. The pronounced charge transfer character of the directly photoexcited state is in principle favorable for a charge injection. Here, we report a time-resolved fluorescence study of a triphenylamine-bithiophene-naphthalimide dye in four solvents of varying polarity using fluorescence upconversion. The recording of femtosecond time-resolved fluorescence spectra corrected for the group velocity dispersion allows for a detailed analysis discriminating between spectral shifts and total intensity decays. After photoexcitation, the directly populated state (S 1 /FC) evolves toward a relaxed charge transfer state (S 1 /CT). This S 1 /CT state is characterized by a lower radiative transition moment and a higher nonradiative quenching. The fast dynamic shift of the fluorescence band is well described by solvation dynamics in polar solvents, but less so in nonpolar solvents, hinting that the excited-state relaxation process occurs on a free energy surface whose topology is strongly governed by the solvent polarity. This study underlines the influence of the environment on the intramolecular charge transfer (ICT) process, and the necessity to analyze time-resolved data in detail when solvation and ICT occur simultaneously.

A simple method for in vivo labelling of infiltrating leukocytes in the mouse retina using indocyanine green dye.

PubMed

Sim, Dawn A; Chu, Colin J; Selvam, Senthil; Powner, Michael B; Liyanage, Sidath; Copland, David A; Keane, Pearse A; Tufail, Adnan; Egan, Catherine A; Bainbridge, James W B; Lee, Richard W; Dick, Andrew D; Fruttiger, Marcus

2015-11-01

We have developed a method to label and image myeloid cells infiltrating the mouse retina and choroid in vivo, using a single depot injection of indocyanine green dye (ICG). This was demonstrated using the following ocular models of inflammation and angiogenesis: endotoxin-induced uveitis, experimental autoimmune uveoretinitis and laser-induced choroidal neovascularization model. A near-infrared scanning ophthalmoscope was used for in vivo imaging of the eye, and flow cytometry was used on blood and spleen to assess the number and phenotype of labelled cells. ICG was administered 72 h before the induction of inflammation to ensure clearance from the systemic circulation. We found that in vivo intravenous administration failed to label any leukocytes, whereas depot injection, either intraperitoneal or subcutaneous, was successful in labelling leukocytes infiltrating into the retina. Progression of inflammation in the retina could be traced over a period of 14 days following a single depot injection of ICG. Additionally, bright-field microscopy, spectrophotometry and flow cytometric analysis suggest that the predominant population of cells stained by ICG are circulating myeloid cells. The translation of this approach into clinical practice would enable visualization of immune cells in situ. This will not only provide a greater understanding of pathogenesis, monitoring and assessment of therapy in many human ocular diseases but might also open the ability to image immunity live for neurodegenerative disorders, cardiovascular disease and systemic immune-mediated disorders. © 2015. Published by The Company of Biologists Ltd.

Calcium transients recorded with arsenazo III in the presynaptic terminal of the squid giant synapse.

PubMed

Miledi, R; Parker, I

1981-05-22

Transient changes in free intracellular Ca2+ concentration were monitored in the presynaptic terminal of the giant synapse of the squid, by means of the Ca2+-sensitive dye arsenazo III. Calibration experiments showed a linear relation between the amount of Ca2+ injected by iontophoresis into the terminal, and the peak size of the arsenazo light absorbance record. A light signal could be detected on tetanic stimulation of the presynaptic axon bathed in sea water containing 45 mM Ca2+. During a 1 s tetanus the light signal rose approximately linearly, even though transmitter release declined rapidly and the light signal subsequently declined with a half-time of 2-6 s. The Ca2+ transient elicited by single nerve impulses was recorded by signal averaging, and showed a time course very much slower than the duration of transmitter release.

Measurement of Bone Growth in Osteopetrosis

PubMed Central

Sanger, V. L.; Frederickson, T. N.; Morrill, C. C.

1964-01-01

Day-old chicks were injected with 0.2 ml. of a suspension of lymphomatosis virus which was known to cause osteopetrosis in a high percentage of susceptible birds. A comparable number of uninoculated chicks were kept for controls. Alizarin red S was administered for the purpose of marking the bones in order to measure the rate of growth of normal bone and the osteopetrotic bone. The dye was given at 27, 41 and 55 days of age. In this experiment it was found that a layer of normal bone was formed on the surface of the tibia at a rate of 0.25 mm. per week but in the largest osteopetrotic lesion that was found in any chicken spongy bone was formed at a rate greater than 1 mm. per week. Alizarin red S was irritating to tissue and was toxic when given intravenously. ImagesFig. 1.Fig. 2. PMID:17649533

Effects of lower limb neurodynamic mobilization on intraneural fluid dispersion of the fourth lumbar nerve root: an unembalmed cadaveric investigation

PubMed Central

Gilbert, Kerry K.; Smith, Michael P.; Sobczak, Stéphane; James, C. Roger; Sizer, Phillip S.; Brismée, Jean-Michel

2015-01-01

Objectives Manual and physical therapists incorporate neurodynamic mobilisation (NDM) to improve function and decrease pain. Little is known about the mechanisms by which these interventions affect neural tissue. The objective of this research was to assess the effects of repetitive straight leg raise (SLR) NDM on the fluid dynamics within the fourth lumbar nerve root in unembalmed cadavers. Methods A biomimetic solution (Toluidine Blue Stock 1% and Plasma) was injected intraneurally, deep to the epineurium, into the L4 nerve roots of seven unembalmed cadavers. The initial dye spread was allowed to stabilise and measured with a digital calliper. Once the initial longitudinal dye spread stabilised, an intervention strategy (repetitive SLR) was applied incorporating NDMs (stretch/relax cycles) at a rate of 30 repetitions per minute for 5 minutes. Post-intervention calliper measurements of the longitudinal dye spread were measured. Results The mean experimental posttest longitudinal dye spread measurement (1.1 ± 0.9 mm) was significantly greater (P = 0.02) than the initial stabilised pretest longitudinal dye spread measurement. Increases ranged from 0.0 to 2.6 mm and represented an average of 7.9% and up to an 18.1% increase in longitudinal dye spread. Discussion Passive NDM in the form of repetitive SLR induced a significant increase in longitudinal fluid dispersion in the L4 nerve root of human cadaveric specimen. Lower limb NDM may be beneficial in promoting nerve function by limiting or altering intraneural fluid accumulation within the nerve root, thus preventing the adverse effects of intraneural oedema. PMID:26955255

Tuning the light emission of novel donor-acceptor phenoxazine dye-based materials towards the red spectral range

NASA Astrophysics Data System (ADS)

Damaceanu, Mariana-Dana; Constantin, Catalin-Paul

2018-04-01

A novel red fluorescent push-pull system able to generate an intramolecular charge-transfer (ICT) complex was synthesized. The novel dye (R-POX) combines some structural features which are rarely encountered in the design of other push-pull systems: hexyl-substituted phenoxazine as donor moiety, divinylketone as π-linker, and p-fluorobenzene as electron acceptor group. The relationship between the structural motif, photo-physical and electrochemical properties by UV-Vis absorption, photoluminescence and cyclic voltammetry was thoroughly investigated both as red dopant in poly(methylmethacrylate) (PMMA) or polyimide (PI) matrix, and non-doped host emitter. The molecular rigid cores of the synthesized dye formed supramolecular rod-like structures in condensed phase with a strong impact on the emissive centers. The aggregation was totally suppressed when the dye was used as dopant in an amorphous polymeric matrix, such as PMMA or PI. Electrochemical measurements revealed the dye ability for both hole and electron injection and transport. The fluorescence emission was found to be highly sensitive to solvent polarity, rendering blue-green, yellow, orange and red light emission in different organic solvents. The absolute fluorescence quantum yield reached 39.57% in solution, and dropped to 1.2% in solid state and to 14.01% when the dye was used as dopant in PMMA matrix. According to the available CIE 1931 standard, R-POX emitted pure and saturated red light of single wavelength with chromaticity coordinates very close to those of National Television System Committee (NTSC) standard red colour. The R-POX photo-optical features were compared to those of the commercial red emitter 6, 13-diphenylpentacene.

Electrochemical attosyringe.

PubMed

Laforge, François O; Carpino, James; Rotenberg, Susan A; Mirkin, Michael V

2007-07-17

The ability to manipulate ultrasmall volumes of liquids is essential in such diverse fields as cell biology, microfluidics, capillary chromatography, and nanolithography. In cell biology, it is often necessary to inject material of high molecular weight (e.g., DNA, proteins) into living cells because their membranes are impermeable to such molecules. All techniques currently used for microinjection are plagued by two common problems: the relatively large injector size and volume of injected fluid, and poor control of the amount of injected material. Here we demonstrate the possibility of electrochemical control of the fluid motion that allows one to sample and dispense attoliter-to-picoliter (10(-18) to 10(-12) liter) volumes of either aqueous or nonaqueous solutions. By changing the voltage applied across the liquid/liquid interface, one can produce a sufficient force to draw solution inside a nanopipette and then inject it into an immobilized biological cell. A high success rate was achieved in injections of fluorescent dyes into cultured human breast cells. The injection of femtoliter-range volumes can be monitored by video microscopy, and current/resistance-based approaches can be used to control injections from very small pipettes. Other potential applications of the electrochemical syringe include fluid dispensing in nanolithography and pumping in microfluidic systems.

Electrochemical attosyringe

PubMed Central

Laforge, François O.; Carpino, James; Rotenberg, Susan A.; Mirkin, Michael V.

2007-01-01

The ability to manipulate ultrasmall volumes of liquids is essential in such diverse fields as cell biology, microfluidics, capillary chromatography, and nanolithography. In cell biology, it is often necessary to inject material of high molecular weight (e.g., DNA, proteins) into living cells because their membranes are impermeable to such molecules. All techniques currently used for microinjection are plagued by two common problems: the relatively large injector size and volume of injected fluid, and poor control of the amount of injected material. Here we demonstrate the possibility of electrochemical control of the fluid motion that allows one to sample and dispense attoliter-to-picoliter (10−18 to 10−12 liter) volumes of either aqueous or nonaqueous solutions. By changing the voltage applied across the liquid/liquid interface, one can produce a sufficient force to draw solution inside a nanopipette and then inject it into an immobilized biological cell. A high success rate was achieved in injections of fluorescent dyes into cultured human breast cells. The injection of femtoliter-range volumes can be monitored by video microscopy, and current/resistance-based approaches can be used to control injections from very small pipettes. Other potential applications of the electrochemical syringe include fluid dispensing in nanolithography and pumping in microfluidic systems. PMID:17620612

Comparison of carpal tunnel injection techniques: a cadaver study.

PubMed

Ozturk, Kahraman; Esenyel, Cem Zeki; Sonmez, Mesut; Esenyel, Meltem; Kahraman, Sinan; Senel, Berna

2008-01-01

The purpose of the study was to evaluate the accuracy of injections into the carpal tunnel using three different portals in cadavers, and to define safe guidelines. In this study, 150 wrists of 75 cadavers (54 male, 21 female) were included. To compare three injection sites, 50 wrists of 25 cadavers were used for each technique; we used 23 gauge needles, and acrylic dye. The first injection technique: the needle was inserted 1cm proximal to the wrist crease and directed distally by roughly 45 in an ulnar direction through the flexor carpi radialis tendon. The second injection technique: the needle was inserted into the carpal tunnel from a point just ulnar to the palmaris longus tendon and 1cm proximal to the wrist crease. The third injection technique: the needle was inserted just distal to the distal skin crease of the wrist in line with the fourth ray. The first injection technique gave the highest accuracy rate, and this was also the safest injection site. Median nerve injuries caused by injection was seen mostly with the second technique. Although a steroid injection may provide symptomatic relief in patients with carpal tunnel syndrome, the median nerve and other structures in the carpal tunnel are at risk of injury. Because of that, the injection should be given using the correct technique by physicians skilled in carpal tunnel surgery.

Summary of the National Toxicology Program benzidine dye initiative.

PubMed Central

Morgan, D L; Dunnick, J K; Goehl, T; Jokinen, M P; Matthews, H B; Zeiger, E; Mennear, J H

1994-01-01

The benzidine dye initiative is a research program established by the National Toxicology Program to generate an integrated body of scientific information regarding the potential health risks associated with exposure to benzidine- and benzidine-congener-derived dyes. Because an in-depth evaluation of each of the hundreds of benzidine-congener-derived dyes was considered impractical, the research program was designed to study the metabolism and disposition, genetic toxicity, and in vivo toxicity and carcinogenicity of two primary benzidine congeners, 3,3'-dimethylbenzidine and 3,3'-dimethoxybenzidine, and a select group of prototypical dyes derived from those amines. It was anticipated that by applying the basic information generated in these extensive studies, it would be possible to make regulatory decisions about other dyes after conducting only a minimal number of experiments such as studies of disposition and metabolism, and in vitro mutagenicity. This paper summarizes the results of studies conducted to evaluate the metabolism, disposition, mutagenicity, toxicity, and carcinogenicity of representative benzidine congeners and derived dyes. PMID:7925189

Microstructured Surface Arrays for Injection of Zebrafish Larvae

PubMed Central

Irimia, Daniel

2017-01-01

Abstract Microinjection of zebrafish larvae is an essential technique for delivery of treatments, dyes, microbes, and xenotransplantation into various tissues. Although a number of casts are available to orient embryos at the single-cell stage, no device has been specifically designed to position hatching-stage larvae for microinjection of different tissues. In this study, we present a reusable silicone device consisting of arrayed microstructures, designed to immobilize 2 days postfertilization larvae in lateral, ventral, and dorsal orientations, while providing maximal access to target sites for microinjection. Injection of rhodamine dextran was used to demonstrate the utility of this device for precise microinjection of multiple anatomical targets. PMID:28151697

Performance comparison of three types of high-speed counter-current chromatographs for the separation of components of hydrophilic and hydrophobic color additives.

PubMed

Weisz, Adrian; Ito, Yoichiro

2011-09-09

The performance of three types of high-speed counter-current chromatography (HSCCC) instruments was assessed for their use in separating components in hydrophilic and hydrophobic dye mixtures. The HSCCC instruments compared were: (i) a J-type coil planet centrifuge (CPC) system with a conventional multilayer-coil column, (ii) a J-type CPC system with a spiral-tube assembly-coil column, and (iii) a cross-axis CPC system with a multilayer-coil column. The hydrophilic dye mixture consisted of a sample of FD&C Blue No. 2 that contained mainly two isomeric components, 5,5'- and 5,7'-disulfonated indigo, in the ratio of ∼7:1. The hydrophobic dye mixture consisted of a sample of D&C Red No. 17 (mainly Sudan III) and Sudan II in the ratio of ∼4:1. The two-phase solvent systems used for these separations were 1-butanol/1.3M HCl and hexane/acetonitrile. Each of the three instruments was used in two experiments for the hydrophilic dye mixture and two for the hydrophobic dye mixture, for a total of 12 experiments. In one set of experiments, the lower phase was used as the mobile phase, and in the second set of experiments, the upper phase was used as the mobile phase. The results suggest that: (a) use of a J-type instrument with either a multilayer-coil column or a spiral-tube assembly column, applying the lower phase as the mobile phase, is preferable for separating the hydrophilic components of FD&C Blue No. 2; and (b) use of a J-type instrument with multilayer-coil column, while applying either the upper phase or the lower phase as the mobile phase, is preferable for separating the hydrophobic dye mixture of D&C Red No. 17 and Sudan II. Published by Elsevier B.V.

Applying tattoo dye as a third-harmonic generation contrast agent for in vivo optical virtual biopsy of human skin

NASA Astrophysics Data System (ADS)

Tsai, Ming-Rung; Lin, Chen-Yu; Liao, Yi-Hua; Sun, Chi-Kuang

2013-02-01

Third-harmonic generation (THG) microscopy has been reported to provide intrinsic contrast in elastic fibers, cytoplasmic membrane, nucleus, actin filaments, lipid bodies, hemoglobin, and melanin in human skin. For advanced molecular imaging, exogenous contrast agents are developed for a higher structural or molecular specificity. We demonstrate the potential of the commonly adopted tattoo dye as a THG contrast agent for in vivo optical biopsy of human skin. Spectroscopy and microscopy experiments were performed on cultured cells with tattoo dyes, in tattooed mouse skin, and in tattooed human skin to demonstrate the THG enhancement effect. Compared with other absorbing dyes or nanoparticles used as exogenous THG contrast agents, tattoo dyes are widely adopted in human skin so that future clinical biocompatibility evaluation is relatively achievable. Combined with the demonstrated THG enhancement effect, tattoo dyes show their promise for future clinical imaging applications.

Novel Strategy for Tracking the Microbial Degradation of Azo Dyes with Different Polarities in Living Cells.

PubMed

Liu, Fei; Xu, Meiying; Chen, Xingjuan; Yang, Yonggang; Wang, Haiji; Sun, Guoping

2015-10-06

Direct visualization evidence is important for understanding the microbial degradation mechanisms. To track the microbial degradation pathways of azo dyes with different polar characterizations, sensors based on the fluorescence resonance energy transfer (FRET) from 1,8-naphthalimide to azo dyes were synthesized, in which the quenched fluorescence will recover when the azo bond was cleaved. In living cells, the sensor-tracking experiment showed that the low polarity and hydrophobic azo dye can be taken up into the cells and reduced inside the cells, whereas the high polarity and hydrophilic azo dye can be reduced only outside the cells because of the selective permeability of the cell membranes. These results indicated that there were two different bacterial degradation pathways available for different polarity azo dyes. To our knowledge, no fluorescent sensor has yet been designed for illuminating the microbial degradation mechanisms of organic pollutants with different characteristics.

Evaluation of Aluminium Dross as Adsorbent for Removal of Carcinogenic Congo Red Dye in Wastewater

NASA Astrophysics Data System (ADS)

Zakaria, Mohamad Zulfika Hazielim b.; Zauzi, Nur Syuhada Ahmad; Baini, Rubiyah; Sutan, Norsuzailina Mohamed; Rezaur Rahman, Md

2017-06-01

In this study, aluminium dross waste generated from aluminium smelting industries was employed as adsorbent in removing of congo red dye in aqueous solution. The raw aluminium dross as adsorbent was characterized using Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET) for surface area and X-Ray Fluorescence (XRF) Spectroscopy. Adsorption experiments were carried out by batch system at different adsorbent mass, pH, and initial dye concentration. The results showed that the per cent removal of dye increased as adsorbent mass increased. It was found that 0.4 gram of adsorbent can remove approximately 100 % of dye at pH 9 for dye concentration 20 and 40 ppm. Therefore, it can be concluded that raw aluminium dross without undergone any treatment can be effectively used for the adsorption of congo red in textile wastewater related industries.

Statistical analysis and mathematical modeling of a tracer test on the Santa Clara River, Ventura County, California

USGS Publications Warehouse

Paybins, Katherine S.; Nishikawa, Tracy; Izbicki, John A.; Reichard, Eric G.

1998-01-01

To better understand flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 28-mile reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. Dye was injected at a site on Piru Creek, and fluorescence of river water was measured continuously at four sites and intermittently at two sites. Discharge measurements were also made at the six sites. The time of travel of the dye, peak dye concentration, and time-variance of time-concentration curves were obtained at each site. The long tails of the time-concentration curves are indicative of sources/sinks within the river, such as riffles and pools, or transient bank storage. A statistical analysis of the data indicates that, in general, the transport characteristics follow Fickian theory. These data and previously collected discharge data were used to calibrate a one-dimensional flow model (DAFLOW) and a solute-transport model (BLTM). DAFLOW solves a simplified form of the diffusion-wave equation and uses empirical relations between flow rate and cross-sectional area, and flow rate and channel width. BLTM uses the velocity data from DAFLOW and solves the advection-dispersion transport equation, including first-order decay. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of dye mass in the middle, ephemeral, subreaches, and (2) ground-water recharge does not explain the loss of dye mass in the uppermost and lowermost, perennial, subreaches. This loss of mass was simulated using a linear decay term. The loss of mass in the perennial subreaches may be caused by a combination of photodecay or adsorption/desorption.

Antiedematogenic effects of the polar fractions of Persea cordata Mez. (Lauraceae) on microvascular extravasation in rat skin.

PubMed

Schlemper, Valfredo; Schlemper, Susana Regina de Mello; Zampirolo, Júlio Araújo

2013-10-28

Persea cordata Mez. (Lauraceae) is a medicinal plant used in veterinary ethnopharmacology, which is a popular medicine used as an anti-inflammatory and healing agent, mainly on animal skin diseases, characterized by cutaneous open wounds, in South Brazil. The purpose of this study was to investigate a possible antiedematogenic effect of ethyl acetate (EtAc) and butanol (BuOH) polar fractions of Persea cordata on Evans blue dye leakage induced by pro-inflammatory agents in rat skin. Male Wistar rats (180-200 g, n=5-6) were pretreated with a single intraperitoneal administration of EtAc or BuOH (1 to 600 mg kg(-1)) fractions followed by intravenous Evans blue dye injection (1%, 30 mg kg(-1), i.v.), 60 min before the injection of phlogistic agents. Animals received intradermal injections (0.05 ml) of carrageenan (CAR, 300 µg/site), 48/80 compound (C4880, 10 µg/site), histamine (HIS, 0.3 µg/site), serotonin (5-HT, 0.01 µg/site), dextran (DEX, 200 µg/site), bradykinin (BK, 0.003 µg/site), capsaicin (CPS, 400 µg/site), substance P (SP, 0.003 µg/site) or prostaglandin E2 (PGE2 10 nmol/site) and they were submitted to euthanasia after 60 min. Skin samples were obtained in the extravasation sites of Evans blue dye. Skin fragments were soaked in formamide at 37°C (during 24h) for Evans blue extraction. The amount of dye leakage in the tissue fragment was determined by a spectrophotometer (620 nm). In a very similar manner in terms of potency and efficacy, systemic administration of EtAc and BuOH fractions caused dose-dependent inhibition of vascular Evans blue dye leakage induced by phlogistic agents in the rat skin. The results obtained (ID50 values in mgkg(-1) and maximal inhibition in %) with EtAc fraction, as follows were: CAR (34.42 and 63.0), 4880 (8.52 and 59.1), HIS (21.22 and 66.8), 5-HT (32.99 and 73.4), DEX (41.74 and 67.0), BK (34.03 and 68.0), CPS (100.7 and 77), SP (2.1 and 78.9) and PGE2 (133 and 71.0). BuOH fraction significantly inhibited CAR (25.9 and 70)-, 4880 (36.8 and 66)-, HIS (17.6 and 77)-, 5-HT (32.8 and 56)-, DEX (89.6 and 75)-, BK (28.0 and 66)-, CPS (136.37 and 71)-, SP (5.6 and 78)- and PGE2 (109.64 and 56)-induced VE, respectively. Systemic administration of Persea cordata polar fractions exerts a non-specific inhibitory effect on microvascular leakage induced by pro-inflammatory agents in rat skin, probably to interfering with different biological systems involved in the development of the inflammatory process, reinforcing the popular use of Persea cordata as an anti-inflammatory and healing agent for skin. © 2013 Elsevier Ireland Ltd. All rights reserved.

Dye bias correction in dual-labeled cDNA microarray gene expression measurements.

PubMed Central

Rosenzweig, Barry A; Pine, P Scott; Domon, Olen E; Morris, Suzanne M; Chen, James J; Sistare, Frank D

2004-01-01

A significant limitation to the analytical accuracy and precision of dual-labeled spotted cDNA microarrays is the signal error due to dye bias. Transcript-dependent dye bias may be due to gene-specific differences of incorporation of two distinctly different chemical dyes and the resultant differential hybridization efficiencies of these two chemically different targets for the same probe. Several approaches were used to assess and minimize the effects of dye bias on fluorescent hybridization signals and maximize the experimental design efficiency of a cell culture experiment. Dye bias was measured at the individual transcript level within each batch of simultaneously processed arrays by replicate dual-labeled split-control sample hybridizations and accounted for a significant component of fluorescent signal differences. This transcript-dependent dye bias alone could introduce unacceptably high numbers of both false-positive and false-negative signals. We found that within a given set of concurrently processed hybridizations, the bias is remarkably consistent and therefore measurable and correctable. The additional microarrays and reagents required for paired technical replicate dye-swap corrections commonly performed to control for dye bias could be costly to end users. Incorporating split-control microarrays within a set of concurrently processed hybridizations to specifically measure dye bias can eliminate the need for technical dye swap replicates and reduce microarray and reagent costs while maintaining experimental accuracy and technical precision. These data support a practical and more efficient experimental design to measure and mathematically correct for dye bias. PMID:15033598

Binding of Phenazinium Dye Safranin T to Polyriboadenylic Acid: Spectroscopic and Thermodynamic Study

PubMed Central

Roy, Snigdha; Das, Suman

2014-01-01

Here, we report results from experiments designed to explore the association of the phenazinium dye safranin T (ST, 3,7-diamino-2,8-dimethyl-5-phenylphenazinium chloride) with single and double stranded form of polyriboadenylic acid (hereafter poly-A) using several spectroscopic techniques. We demonstrate that the dye binds to single stranded polyriboadenylic acid (hereafter ss poly-A) with high affinity while it does not interact at all with the double stranded (ds) form of the polynucleotide. Fluorescence and absorption spectral studies reveal the molecular aspects of binding of ST to single stranded form of the polynucleotide. This observation is also supported by the circular dichroism study. Thermodynamic data obtained from temperature dependence of binding constant reveals that association is driven by negative enthalpy change and opposed by negative entropy change. Ferrocyanide quenching studies have shown intercalative binding of ST to ss poly-A. Experiments on viscosity measurements confirm the binding mode of the dye to be intercalative. The effect of [Na+] ion concentration on the binding process suggests the role of electrostatic forces in the complexation. Present studies reveal the utility of the dye in probing nucleic acid structure. PMID:24498422

Binding of phenazinium dye safranin T to polyriboadenylic acid: spectroscopic and thermodynamic study.

PubMed

Pradhan, Ankur Bikash; Haque, Lucy; Roy, Snigdha; Das, Suman

2014-01-01

Here, we report results from experiments designed to explore the association of the phenazinium dye safranin T (ST, 3,7-diamino-2,8-dimethyl-5-phenylphenazinium chloride) with single and double stranded form of polyriboadenylic acid (hereafter poly-A) using several spectroscopic techniques. We demonstrate that the dye binds to single stranded polyriboadenylic acid (hereafter ss poly-A) with high affinity while it does not interact at all with the double stranded (ds) form of the polynucleotide. Fluorescence and absorption spectral studies reveal the molecular aspects of binding of ST to single stranded form of the polynucleotide. This observation is also supported by the circular dichroism study. Thermodynamic data obtained from temperature dependence of binding constant reveals that association is driven by negative enthalpy change and opposed by negative entropy change. Ferrocyanide quenching studies have shown intercalative binding of ST to ss poly-A. Experiments on viscosity measurements confirm the binding mode of the dye to be intercalative. The effect of [Na⁺] ion concentration on the binding process suggests the role of electrostatic forces in the complexation. Present studies reveal the utility of the dye in probing nucleic acid structure.

Dyeing Insects for Behavioral Assays: the Mating Behavior of Anesthetized Drosophila

PubMed Central

Verspoor, Rudi L.; Heys, Chloe; Price, Thomas A. R.

2015-01-01

Mating experiments using Drosophila have contributed greatly to the understanding of sexual selection and behavior. Experiments often require simple, easy and cheap methods to distinguish between individuals in a trial. A standard technique for this is CO2 anaesthesia and then labelling or wing clipping each fly. However, this is invasive and has been shown to affect behavior. Other techniques have used coloration to identify flies. This article presents a simple and non-invasive method for labelling Drosophila that allows them to be individually identified within experiments, using food coloring. This method is used in trials where two males compete to mate with a female. Dyeing allowed quick and easy identification. There was, however, some difference in the strength of the coloration across the three species tested. Data is presented showing the dye has a lower impact on mating behavior than CO2 in Drosophila melanogaster. The impact of CO2 anaesthesia is shown to depend on the species of Drosophila, with D. pseudoobscura and D. subobscura showing no impact, whereas D. melanogaster males had reduced mating success. The dye method presented is applicable to a wide range of experimental designs. PMID:25938821

Electroadsorption of acilan blau dye from textile effluents by using activated carbon-perlite mixtures.

PubMed

Koparal, A S; Yavuz, Y; Bakir Ogütveren, U

2002-01-01

The feasibility of the removal of dye stuffs from textile effluents by electroadsorption has been investigated. An activated carbon-perlite mixture with a ratio of 8:1 for bipolarity has been used as the adsorbent. Conventional adsorption experiments have also been conducted for comparison. A bipolar trickle reactor has been used in the electroadsorption experiments. The model wastewater has been prepared by using acilan blau dye. Initial dye concentration, bed height between the electrodes, applied potential, flowrate, and the supporting electrolyte concentration have been examined as the parameters affecting the removal efficiency. A local textile plant effluent has been treated in the optimum values of these parameters obtained from the experimental studies. Adsorption kinetics and the amount of adsorbent required to reach the maximum removal efficiency have also been investigated and mass-transfer coefficients have been calculated for adsorption and electroadsorption. The results showed that a removal efficiency of up to 100% can be achieved with energy consumption values of 1.58 kWh/m3 of wastewater treated. However, energy consumption decreases to 0.09 kWh/m3 if an exit dye concentration of 4.65 mg/L is accepted. It can be concluded from this work that this method combines all of the advantages of the activated-carbon adsorption and electrolytic methods for the removal of dyes from wastewater.

Optical properties of natural dyes on the dye-sensitized solar cells (DSSC) performance

NASA Astrophysics Data System (ADS)

Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

2016-11-01

This study reported several natural dyes for application in dye-sensitized solar cells (DSSC). This study aims was to determine the effect of optical absorption properties of natural dyes on efficiency of DSSC. The sandwich structure of DSSC consist of TiO2 as working electrode, carbon layer as counter electrode, natural dyes as photosensitizer, and electrolyte as electron transfer media. The natural dyes used in this experiment were extracted from dragon fruit anthocyanin, mangosteen peels anthocyanin, and red cabbage anthocyanin. The absorbance of dyes solutions and the adsorption of the dye on the surface of TiO2 were characterized using UV-Vis spectrophotometer, the quantum efficiency versus wavelength was characterized using incident photon-to-current efficiency (IPCE) measurement system, and the efficiency of DSSC was calculated using I-V meter. UV-Vis characteristic curves showed that wavelength absorption of anthocyanin dye of red cabbage was 450 - 580 nm, anthocyanin of mangosteen peels was 400 - 480 nm, and anthocyanin of dragon fruit was 400 - 650 nm. Absorption spectra of the dye adsorption on the surface of TiO2 which was resulted in the highest absorbance of red cabbage anthocyanin. IPCE characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted quantum efficiency of 0.058%; 0.047%; and 0.043%, respectively at wavelength maximum about 430 nm. I-V characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted efficiency of 0.054%; 0.042%; and 0.024%, respectively.

Self-healing of optical functions by molecular metabolism in a swollen elastomer

NASA Astrophysics Data System (ADS)

Saito, Mitsunori; Nishimura, Tatsuya; Sakiyama, Kohei; Inagaki, Sota

2012-12-01

Optical functions of organic dyes, e.g., fluorescence or photochromism, tend to degrade by light irradiation, which causes a short lifetime of photonic devices. Self-healing of optical functions is attainable by metabolizing bleached molecules with nonirradiated ones. A polydimethylsiloxane elastomer provides a useful matrix for dye molecules, since its flexible structure with nano-sized intermolecular spaces allows dye diffusion from a reservoir to an operation region. Swelling the elastomer with a suitable solvent promotes both dissolution and diffusion of dye molecules. This self-healing function was demonstrated by an experiment in which a photochromic elastomer exhibited improved durability against a repeated coloring-decoloring process.

Conformational stability and aggregation of therapeutic monoclonal antibodies studied with ANS and Thioflavin T binding.

PubMed

Kayser, Veysel; Chennamsetty, Naresh; Voynov, Vladimir; Helk, Bernhard; Trout, Bernhardt L

2011-01-01

Characterization of aggregation profiles of monoclonal antibodies (mAb) is gaining importance because an increasing number of mAb-based therapeutics are entering clinical studies and gaining marketing approval. To develop a successful formulation, it is imperative to identify the critical biochemical properties of each potential mAb drug candidate. We investigated the conformational change and aggregation of a human IgG1 using external dye-binding experiments with fluorescence spectroscopy and compared the aggregation profiles obtained to the results of size-exclusion chromatography. We show that using an appropriate dye at selected mAb concentration, unfolding or aggregation can be studied. In addition, dye-binding experiments may be used as conventional assays to study therapeutic mAb stability.

Femtosecond solvation and the bandshape of polar dyes

NASA Astrophysics Data System (ADS)

Ernsting, N. P.; Eilers-König, N.; Kemeter, K.; Kovalenko, S.; Ruthmann, J.

1996-04-01

The bandwidth of gain spectra for the dye DASPI in polar solvents and its evolution is described by Brownian oscillators with different frequencies for the ground- and excited electronic states. Comparison with experiments reveals a fast relaxation process which is assigned to vibrational redistribution.

An efficient dye-sensitized BiOCl photocatalyst for air and water purification under visible light irradiation.

PubMed

Li, Guisheng; Jiang, Bo; Xiao, Shuning; Lian, Zichao; Zhang, Dieqing; Yu, Jimmy C; Li, Hexing

2014-08-01

A photosensitized BiOCl catalyst was found to be effective for photocatalytic water purification and air remediation under visible light irradiation (λ > 420 nm). Prepared by a solvothermal method, the BiOCl crystals possessed a 3D hierarchical spherical structure with the highly active facets exposed. When sensitized by Rhodamine B (RhB), the photocatalyst system was more active than N-doped TiO2 for breaking down 4-chlorophenol (4-CP, 200 ppm) and nitric monoxide (NO, 500 ppb). The high activity could be attributed to the hierarchical structure (supplying feasible reaction tunnels for adsorption and transition of reactants or products) and the efficient exposure of the {001} facets. The former provides an enriched oxygen atom density that promotes adsorption of cationic dye RhB, and creates an oxygen vacancy state. The HO˙ and ˙O2(-) radicals produced from the injected electrons from the excited dye molecule (RhB*) into the conduction band of BiOCl were responsible for the excellent photocatalytic performance of the RhB-BiOCl system.

[Allergic reaction to patent blue dye in breast surgery - case report].

PubMed

Maranhão, Marcius Vinícius M; Nóbrega, Dyluzia Kelly Amaral da; Anunciação, Carlos Eduardo Caiado; Maia, Barbara de Alcântara Brito; Mariano, Paulo Virgílio Dantas

2016-01-01

We present a case of allergic reaction to patent blue in a patient who underwent excision of sentinel lymph node associated with segmental breast resection. About 20minutes after the dye injection, the patient developed hypotension (BP=70×30mmHg) associated with increased heart frequency. The patient was treated successfully with decreased inspired fraction of inhaled anesthetic and fluid replacement. At the end of the procedure, she presented with bluish urticarial - like plaques on the head, neck, upper limbs, and trunk; hydrocortisone was then used. The patient recovered uneventfully and was discharged from the PACU two hours after the end of surgery without skin changes, and was discharged from hospital on the morning after surgery. The incidence of allergic reactions with the use of patent blue is far superior to the hypersensitivity reactions seen with anesthetic and adjuvant drugs. Therefore, the anesthesiologist must be aware of cardiovascular instability associated with skin changes during the use of patent blue, for early diagnosis and appropriate treatment of this hypersensitivity reaction to this dye. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Allergic reaction to patent blue dye in breast surgery - case report.

PubMed

Maranhão, Marcius Vinícius M; da Nóbrega, Dyluzia Kelly Amaral; Anunciação, Carlos Eduardo Caiado; Maia, Barbara de Alcântara Brito; Mariano, Paulo Virgílio Dantas

2016-01-01

We present a case of allergic reaction to patent blue in a patient who underwent excision of sentinel lymph node associated with segmental breast resection. About 20min after the dye injection, the patient developed hypotension (BP=70×30mmHg) associated with increased heart frequency. The patient was treated successfully with decreased inspired fraction of inhaled anesthetic and fluid replacement. At the end of the procedure, she presented with bluish urticarial-like plaques on the head, neck, upper limbs, and trunk; hydrocortisone was then used. The patient recovered uneventfully and was discharged from the PACU 2h after the end of surgery without skin changes, and was discharged from hospital on the morning after surgery. The incidence of allergic reactions with the use of patent blue is far superior to the hypersensitivity reactions seen with anesthetic and adjuvant drugs. Therefore, the anesthesiologist must be aware of cardiovascular instability associated with skin changes during the use of patent blue, for early diagnosis and appropriate treatment of this hypersensitivity reaction to this dye. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Facile synthesis of Zn1-xCoxO/ZnO core/shell nanostructures and their application to dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Manthina, Venkata; Agrios, Alexander G.

2017-04-01

Heterostructures consisting of Co-doped ZnO nanorod cores encased in an undoped ZnO shell were successfully synthesized to serve as photoanodes for dye-sensitized solar cells (DSSCs) by a two-step chemical bath deposition (CBD) technique. This yields a highly favorable structure in which electrons injected from the dye into the ZnO then step down in energy into the Co-doped core, where the electron is transported to the collector while the ZnO shell acts as a barrier to recombination with the electrolyte. Incorporation of the core/shell structures into DSSCs resulted in large improvements in photocurrent and photovoltage in comparison to pure ZnO nanorod-based DSSCs. SEM and XRD characterization indicate incorporation of the Co2+ into the ZnO matrix, without separation of the Co into other phases, providing no energy barriers. In addition, the ability of these heterostructures to reduce recombination rates in redox couples with fast recombination rates was probed by comparing DSSC device performance in both iodide/triiodide-based and ferrocene/ferrocenium-based electrolytes.

Solar H2 evolution in water with modified diketopyrrolopyrrole dyes immobilised on molecular Co and Ni catalyst–TiO2 hybrids† †Electronic supplementary information (ESI) available: Experimental details, synthetic procedures, additional tables and figures. See DOI: 10.1039/c6sc05219c Click here for additional data file.

PubMed Central

Warnan, Julien; Willkomm, Janina; Ng, Jamues N.; Godin, Robert; Prantl, Sebastian; Durrant, James R.

2017-01-01

A series of diketopyrrolopyrrole (DPP) dyes with a terminal phosphonic acid group for attachment to metal oxide surfaces were synthesised and the effect of side chain modification on their properties investigated. The organic photosensitisers feature strong visible light absorption (λ = 400 to 575 nm) and electrochemical and fluorescence studies revealed that the excited state of all dyes provides sufficient driving force for electron injection into the TiO2 conduction band. The performance of the DPP chromophores attached to TiO2 nanoparticles for photocatalytic H2 evolution with co-immobilised molecular Co and Ni catalysts was subsequently studied, resulting in solar fuel generation with a dye-sensitised semiconductor nanoparticle system suspended in water without precious metal components. The performance of the DPP dyes in photocatalysis did not only depend on electronic parameters, but also on properties of the side chain such as polarity, steric hinderance and hydrophobicity as well as the specific experimental conditions and the nature of the sacrificial electron donor. In an aqueous pH 4.5 ascorbic acid solution with a phosphonated DuBois-type Ni catalyst, a DPP-based turnover number (TONDPP) of up to 205 was obtained during UV-free simulated solar light irradiation (100 mW cm–2, AM 1.5G, λ > 420 nm) after 1 day. DPP-sensitised TiO2 nanoparticles were also successfully used in combination with a hydrogenase or platinum instead of the synthetic H2 evolution catalysts and the platinum-based system achieved a TONDPP of up to 2660, which significantly outperforms an analogous system using a phosphonated Ru tris(bipyridine) dye (TONRu = 431). Finally, transient absorption spectroscopy was performed to study interfacial recombination and dye regeneration kinetics revealing that the different performances of the DPP dyes are most likely dictated by the different regeneration efficiencies of the oxidised chromophores. PMID:28451376

Metal-free organic sensitizers for use in water-splitting dye-sensitized photoelectrochemical cells

PubMed Central

Swierk, John R.; Méndez-Hernández, Dalvin D.; McCool, Nicholas S.; Liddell, Paul; Terazono, Yuichi; Pahk, Ian; Tomlin, John J.; Oster, Nolan V.; Moore, Thomas A.; Moore, Ana L.; Gust, Devens; Mallouk, Thomas E.

2015-01-01

Solar fuel generation requires the efficient capture and conversion of visible light. In both natural and artificial systems, molecular sensitizers can be tuned to capture, convert, and transfer visible light energy. We demonstrate that a series of metal-free porphyrins can drive photoelectrochemical water splitting under broadband and red light (λ > 590 nm) illumination in a dye-sensitized TiO2 solar cell. We report the synthesis, spectral, and electrochemical properties of the sensitizers. Despite slow recombination of photoinjected electrons with oxidized porphyrins, photocurrents are low because of low injection yields and slow electron self-exchange between oxidized porphyrins. The free-base porphyrins are stable under conditions of water photoelectrolysis and in some cases photovoltages in excess of 1 V are observed. PMID:25583488

Mode selection and frequency tuning by injection in pulsed TEA-CO2 lasers

NASA Technical Reports Server (NTRS)

Flamant, P. H.; Menzies, R. T.

1983-01-01

An analytical model characterizing pulsed-TEA-CO2-laser injection locking by tunable CW-laser radiation is presented and used to explore the requirements for SLM pulse generation. Photon-density-rate equations describing the laser mechanism are analyzed in terms of the mode competition between photon densities emitted at two frequencies. The expression derived for pulsed dye lasers is extended to homogeneously broadened CO2 lasers, and locking time is defined as a function of laser parameters. The extent to which injected radiation can be detuned from the CO2 line center and continue to produce SLM pulses is investigated experimentally in terms of the analytical framework. The dependence of locking time on the detuning/pressure-broadened-halfwidth ratio is seen as important for spectroscopic applications requiring tuning within the TEA-laser line-gain bandwidth.

Internal Representation and Memory Formation of Odor Preference Based on Oscillatory Activities in a Terrestrial Slug

ERIC Educational Resources Information Center

Sekiguchi, Tatsuhiko; Furudate, Hiroyuki; Kimura, Tetsuya

2010-01-01

The terrestrial slug "Limax" exhibits a highly developed ability to learn odors with a small nervous system. When a fluorescent dye, Lucifer Yellow (LY), is injected into the slug's body cavity after odor-taste associative conditioning, a group of neurons in the procerebral (PC) lobe, an olfactory center of the slug, is labeled by LY. We examined…

Turnable Blue-Green LIDAR Transmitter Demonstration: Injection Laser Technology

DTIC Science & Technology

1990-08-30

5-1 5.2 Baseline Requirements ............................................. 5-1 5.3 Optical Parametric Oscillator Using Beta Barium Borate... optical parametric oscillators , and organic dye lasers. Tunable solid state lasers such as Ti: sapphire operate in the infrared and would have to be...The same is true of I frequency mixing schemes. Optical parametric oscillators (OPOs) are attractive because of their extremely wide potential tuning

Imaging the photoinduced charge injection in CdS/TiO2 nanoparticles by the sequential fluorescence mapping method

NASA Astrophysics Data System (ADS)

Frederice, Rafael; Lencione, Diego; Gehlen, Marcelo H.

2017-03-01

The combination of a sensitizer and TiO2 nanoparticles forming a photocatalytic material is a central issue in many fields of applied photochemistry. The charge injection of emissive sensitizers into the conduction band of the semiconductor TiO2 may form a photoactive region that becomes dark, or it has a very low emission signal due to the generation of sensitizer radicals. However, by sequential coupling of a selected photoredox dye, such as resazurin, the dark region may become fluorescent at the interfaces where the charge injection has taken place due to the concomitant formation of fluorescent resorufin by cascade electron transfer. Using this strategy and a total internal reflection fluorescence microscopy (TIRFM) image, the charge injection in TiO2/CdS and SiO2/TiO2/CdS nanoparticles is investigated The method allows the charge injection efficiency of the excited CdS into TiO2 to be evaluated qualitatively, explaining the differences observed for these photocatalytic materials in H2 generation.

Imaging the photoinduced charge injection in CdS/TiO2 nanoparticles by the sequential fluorescence mapping method.

PubMed

Frederice, Rafael; Lencione, Diego; Gehlen, Marcelo H

2017-02-10

The combination of a sensitizer and TiO 2 nanoparticles forming a photocatalytic material is a central issue in many fields of applied photochemistry. The charge injection of emissive sensitizers into the conduction band of the semiconductor TiO 2 may form a photoactive region that becomes dark, or it has a very low emission signal due to the generation of sensitizer radicals. However, by sequential coupling of a selected photoredox dye, such as resazurin, the dark region may become fluorescent at the interfaces where the charge injection has taken place due to the concomitant formation of fluorescent resorufin by cascade electron transfer. Using this strategy and a total internal reflection fluorescence microscopy (TIRFM) image, the charge injection in TiO 2 /CdS and SiO 2 /TiO 2 /CdS nanoparticles is investigated The method allows the charge injection efficiency of the excited CdS into TiO 2 to be evaluated qualitatively, explaining the differences observed for these photocatalytic materials in H 2 generation.

Near-infrared (NIR) fluorescence imaging of head and neck squamous cell carcinoma for fluorescence-guided surgery (Conference Presentation)

NASA Astrophysics Data System (ADS)

Moore, Lindsay; Warram, Jason M.; de Boer, Esther; Carroll, William R.; Morlandt, Anthony; Withrow, Kirk P.; Rosenthal, Eben L.

2016-03-01

During fluorescence-guided surgery, a cancer-specific optical probe is injected and visualized using a compatible device intraoperatively to provide visual contrast between diseased and normal tissues to maximize resection of cancer and minimize the resection of precious adjacent normal tissues. Six patients with squamous cell carcinomas of the head and neck region (oral cavity (n=4) or cutaneous (n=2)) were injected with an EGFR-targeting antibody (Cetuximab) conjugated to a near-infrared (NIR) fluorescent dye (IRDye800) 3, 4, or 7 days prior to surgical resection of the cancer. Each patient's tumor was then imaged using a commercially available, open-field NIR fluorescence imaging device each day prior to surgery, intraoperatively, and post-operatively. The mean fluorescence intensity (MFI) of the tumor was calculated for each specimen at each imaging time point. Adjacent normal tissue served as an internal anatomic control for each patient to establish a patient-matched "background" fluorescence. Resected tissues were also imaged using a closed-field NIR imaging device. Tumor to background ratios (TBRs) were calculated for each patient using both devices. Fluorescence histology was correlated with traditional pathology assessment to verify the specificity of antibody-dye conjugate binding. Peak TBRs using the open-field device ranged from 2.2 to 11.3, with an average TBR of 4.9. Peak TBRs were achieved between days 1 and 4. This study demonstrated that a commercially available NIR imaging device suited for intraoperative and clinical use can successfully be used with a fluorescently-labeled dye to delineate between diseased and normal tissue in this single cohort human study, illuminated the potential for its use in fluoresence-guided surgery.

From Conventional Radiotracer Tc-99(m) with Blue Dye to Indocyanine Green Fluorescence: A Comparison of Methods Towards Optimization of Sentinel Lymph Node Mapping in Early Stage Cervical Cancer for a Laparoscopic Approach.

PubMed

Buda, Alessandro; Papadia, Andrea; Zapardiel, Ignacio; Vizza, Enrico; Ghezzi, Fabio; De Ponti, Elena; Lissoni, Andrea Alberto; Imboden, Sara; Diestro, Maria Dolores; Verri, Debora; Gasparri, Maria Luisa; Bussi, Beatrice; Di Martino, Giampaolo; de la Noval, Begoña Diaz; Mueller, Michael; Crivellaro, Cinzia

2016-09-01

The credibility of sentinel lymph node (SLN) mapping is becoming increasingly more established in cervical cancer. We aimed to assess the sensitivity of SLN biopsy in terms of detection rate and bilateral mapping in women with cervical cancer by comparing technetium-99 radiocolloid (Tc-99(m)) and blue dye (BD) versus fluorescence mapping with indocyanine green (ICG). Data of patients with cervical cancer stage 1A2 to 1B1 from 5 European institutions were retrospectively reviewed. All centers used a laparoscopic approach with the same intracervical dye injection. Detection rate and bilateral mapping of ICG were compared, respectively, with results obtained by standard Tc-99(m) with BD. Overall, 76 (53 %) of 144 of women underwent preoperative SLN mapping with radiotracer and intraoperative BD, whereas 68 of (47 %) 144 patients underwent mapping using intraoperative ICG. The detection rate of SLN mapping was 96 % and 100 % for Tc-99(m) with BD and ICG, respectively. Bilateral mapping was achieved in 98.5 % for ICG and 76.3 % for Tc-99(m) with BD; this difference was statistically significant (p < 0.0001). The fluorescence SLN mapping with ICG achieved a significantly higher detection rate and bilateral mapping compared to standard radiocolloid and BD technique in women with early stage cervical cancer. Nodal staging with an intracervical injection of ICG is accurate, safe, and reproducible in patients with cervical cancer. Before replacing lymphadenectomy completely, the additional value of fluorescence SLN mapping on both perioperative morbidity and survival should be explored and confirmed by ongoing controlled trials.

Theoretical investigation of the charge-transfer properties in different meso-linked zinc porphyrins for highly efficient dye-sensitized solar cells.

PubMed

Namuangruk, Supawadee; Sirithip, Kanokkorn; Rattanatwan, Rattanawelee; Keawin, Tinnagon; Kungwan, Nawee; Sudyodsuk, Taweesak; Promarak, Vinich; Surakhot, Yaowarat; Jungsuttiwong, Siriporn

2014-06-28

The charge transfer effect of different meso-substituted linkages on porphyrin analogue 1 (A1, B1 and C1) was theoretically investigated using density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. The calculated geometry parameters and natural bond orbital analysis reveal that the twisted conformation between porphyrin macrocycle and meso-substituted linkages leads to blocking of the conjugation of the conjugated backbone, and the frontier molecular orbital plot shows that the intramolecular charge transfer of A1, B1 and C1 hardly takes place. In an attempt to improve the photoinduced intramolecular charge transfer ability of the meso-linked zinc porphyrin sensitizer, a strong electron-withdrawing group (CN) was introduced into the anchoring group of analogue 1 forming analogue 2 (A2, B2 and C2). The density difference plot of A2, B2 and C2 shows that the charge transfer properties dramatically improved. The electron injection process has been performed using TDDFT; the direct charge-transfer transition in the A2-(TiO2)38 interacting system takes place; our results strongly indicated that introducing electron-withdrawing groups into the acceptor part of porphyrin dyes can fine-tune the effective conjugation length of the π-spacer and improve intramolecular charge transfer properties, consequently inducing the electron injection process from the anchoring group of the porphyrin dye to the (TiO2)38 surface which may improve the conversion efficiency of the DSSCs. Our calculated results can provide valuable information and a promising outlook for computation-aided sensitizer design with anticipated good properties in further experimental synthesis.

Experimental Study on Treatment of Dyeing Wastewater by Activated Carbon Adsorption, Coagulation and Fenton Oxidation

NASA Astrophysics Data System (ADS)

Xiaoxu, SUN; Jin, XU; Xingyu, LI

2017-12-01

In this paper dyeing waste water was simulated by reactive brilliant blue XBR, activated carbon adsorption process, coagulation process and chemical oxidation process were used to treat dyeing waste water. In activated carbon adsorption process and coagulation process, the water absorbance values were measured. The CODcr value of water was determined in Fenton chemical oxidation process. Then, the decolorization rate and COD removal rate were calculated respectively. The results showed that the optimum conditions of activated carbon adsorption process were as follows: pH=2, the dosage of activated carbon was 1.2g/L, the adsorption reaction time was 60 min, and the average decolorization rate of the three parallel experiments was 85.30%. The optimum conditions of coagulation experiment were as follows: pH=8~9, PAC dosage was 70mg/L, stirring time was 20min, standing time was 45min, the average decolorization rate of the three parallel experiments was 74.48%. The optimum conditions for Fenton oxidation were Fe2+ 0.05g/L, H2O2 (30%) 14mL/L, pH=3, reaction time 40min. The average CODcr removal rate was 69.35% in three parallel experiments. It can be seen that in the three methods the activated carbon adsorption treatment of dyeing wastewater was the best one.

Degradation characteristic of monoazo, diazo and anthraquinone dye by UV / H2O2 process

NASA Astrophysics Data System (ADS)

Abidin, Che Zulzikrami Azner; Fahmi, Muhammad Ridwan; Fazara, Md Ali Umi; Nadhirah, Siti Nurfatin

2014-10-01

In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV / H2O2 process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV / H2O2 experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV / H2O2 process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H2O2 photolysis.

Can H-aggregates serve as light-harvesting antennae? Triplet-triplet energy transfer between excited aggregates and monomer thionine in aerosol-OT solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, S.; Kamat, P.V.

1999-01-07

The cationic dye thionine undergoes slow dissolution in aerosol-OT (AOT) containing solutions of heptane and toluene. By controlling the ratio of [dye]/[AOT], it is possible to obtain varying amounts of monomer, dimer, and higher order aggregates (trimer) in dilute dye solutions. The thionine aggregates exhibit characteristic absorption maxima at 565 and 530 nm for the dimer and trimer forms, respectively. The singlet excited states of these dye aggregates are short-lived ({tau} = 40--63 ps) as they undergo efficient intersystem crossing to generate the triplet excited states. Triplet energy transfer from the excited dye aggregates to monomeric thionine molecules was observedmore » upon excitation with a 532 nm laser pulse. Pulse radiolysis experiments, in which the excited triplet states were generated indirectly, also confirm the finding that the triplet energy cascades down from excited trimer to dimer to monomeric dye. These studies demonstrate the possibility of using H-type dye aggregates as antenna molecules to harvest light energy whereby the aggregate molecules absorb light in different spectral regions and subsequently transfer energy to the monomeric dye.« less

Trapping characteristic of halloysite lumen for methyl orange

NASA Astrophysics Data System (ADS)

Chen, Hao; Yan, Hua; Pei, Zhenzhao; Wu, Junyong; Li, Rongrong; Jin, Yanxian; Zhao, Jie

2015-08-01

The interaction of clay minerals and dyes is an area of great interest especially in the development of novel adsorbents. In this report, we demonstrated interaction of halloysite nanotubes (HNTs) and an anionic dye, methyl orange (MO), through a electrostatic attraction. Halloysite lumen has a trapping characteristic for methyl orange, which is mainly determined by the positively charged nature of the inner surface of HNTs. XRD results confirmed that intercalation of methyl orange into HNTs did not occur. SEM-EDS and photostability results showed that MO molecules were primarily in HNTs lumen. Adsorption isotherm studies revealed an interesting phenomenon, i.e., a sudden increase of adsorption capacity occurred in the initial dye concentration of about 75 mg/L, which was just the dye concentration corresponding to the onset of dye oligomer formation. This suggested dye aggregation state had a decisive influence to the adsorption behavior of MO on the halloysite. BET results demonstrated at low and high dye concentrations, single MO molecule and aggregation of several dimers through hydrophobic interaction, interacted with Al-OH2+ sites on the inner wall, respectively. Desorption experiments showed that MO in HNTs can be completely removed with deionized water, indicating halloysite is a low-cost and efficient adsorbent for anionic dye.

Quantification of the luminescence intensity of natural materials

NASA Technical Reports Server (NTRS)

Watson, R. D.; Hessin, T. D.; Hemphill, W. R.

1973-01-01

Review of some of the results of an evaluation of the use of an airborne Fraunhofer line discriminator (FLD) for the detection of sun-stimulated luminescence emitted by rhodamine WT dye and some other materials. Rhodamine dye is reported to have been detected by airborne FDL in sea water in concentrations of less than 2 ppb. Experiments with a fluorescence spectrometer in the laboratory indicate that luminescence of some samples of crude and refined petroleum exceeds the luminescence intensity of rhodamine dye in concentrations of 10 ppm.

Altering the Microenvironment to Promote Dormancy of Metastatic Breast Cancer Cell in a 3D Bone Culture System

DTIC Science & Technology

2015-04-01

53.1 73.2 0.27 0.24 This loss of collagen was also detected when the dyes were eluted and quantified (Table 1). At three weeks the collagen...proteins, respectively. After washing away excess dye , samples were allowed to dry and were photographed using light microscopy (Right). In...another set of experiments (Table 1,below) the bound dye was eluted and optical density at 540 nm and 605 nm was used to calculate the collagenous and

Altering the Microenvironment to Promote Dormancy of Metastatic Breast Cancer Cell in a 3D Bone Culture System

DTIC Science & Technology

2015-12-01

detected when the dyes were eluted and quantified (Table 1). At three weeks the collagen produced in the presence of ICI was about 45% less than that seen... dye , samples were allowed to dry and were photographed using light microscopy (Right). In another set of experiments (Table1,below) the bound... dye was eluted and optical density at 540 nm and 605 nm was used to calculate the collagenous and non-collagenous proteins, respectively. Samples

Application of Temperature-Dependent Fluorescent Dyes to the Measurement of Millimeter Wave Absorption in Water Applied to Biomedical Experiments

PubMed Central

Popenko, Oleksandr

2014-01-01

Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in small biological objects. PMID:25435859

Application of temperature-dependent fluorescent dyes to the measurement of millimeter wave absorption in water applied to biomedical experiments.

PubMed

Kuzkova, Nataliia; Popenko, Oleksandr; Yakunov, Andrey

2014-01-01

Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in small biological objects.

Simplification and improvement of protein detection in two-dimensional electrophoresis gels with SERVA HPE™ lightning red.

PubMed

Griebel, Anja; Obermaier, Christian; Westermeier, Reiner; Moche, Martin; Büttner, Knut

2013-07-01

A new fluorescent amino-reactive dye has been tested for both labelling proteins prior to electrophoretic separations and between the two steps of two-dimensional electrophoresis. A series of experiments showed, that the labelling of lysines with this dye is compatible with all standard additives used for sample preparation, including reducing substances and carrier ampholytes. Using this dye for pre-labelling considerably simplifies the electrophoresis and detection workflow and provides highly sensitive and quantitative visualisation of proteins.

Ionic Liquid Electrolytes for Flexible Dye-Sensitized Solar Cells

DTIC Science & Technology

2014-09-01

High-Efficiency Solar - Cell Based on Dye-Sensitized Colloidal TiO2 Films,” a DSSC consists of four main components: a photoanode, a counter... solar cell modules. 2. Experiment and Calculations 2.1 Materials Commercial TiO2 paste was purchased from Dyesol, and additional nanophase TiO2 ...B.; Grätzel, M. A Low-Cost, High Efficiency Solar Cell Based on Dye_Sensitized Colloidal TiO2 Films. Nature 1991, 353, 737–740. 2. Snaith, H. J

Determination of stream reaeration coefficients by use of tracers

USGS Publications Warehouse

Kilpatrick, F.A.; Rathbun, R.E.; Yotsukura, Nobuhiro; Parker, G.W.; DeLong, L.L.

1989-01-01

Stream reaeration is the physical absorption of oxygen from the atmosphere by a flowing stream. This is the primary process by which a stream replenishes the oxygen consumed in the biodegradation of organic wastes. Prior to 1965, reaeration rate coefficients could be estimated only by indirect methods. In 1965, a direct method of measuring stream reaeration coefficients was developed whereby a radioactive tracer gas was injected into a stream-the principle being that the tracer gas would be desorbed from the stream inversely to how oxygen would be absorbed. The technique has since been modified by substituting hydrocarbon gases for the radioactive tracer gas. This manual describes the slug-injection and constant-rate-injection methods of measuring gas-tracer desorption. Emphasis is on the use of rhodamine WT dye as a relatively conservative tracer and propane as the nonconservative gas tracer, on planning field tests, on methods of injection, sampling, and analysis, and on techniques for computing desorption and reaeration coefficients.

Tracer gauge: An automated dye dilution gauging system for ice‐affected streams

USGS Publications Warehouse

Clow, David W.; Fleming, Andrea C.

2008-01-01

In‐stream flow protection programs require accurate, real‐time streamflow data to aid in the protection of aquatic ecosystems during winter base flow periods. In cold regions, however, winter streamflow often can only be estimated because in‐channel ice causes variable backwater conditions and alters the stage‐discharge relation. In this study, an automated dye dilution gauging system, a tracer gauge, was developed for measuring discharge in ice‐affected streams. Rhodamine WT is injected into the stream at a constant rate, and downstream concentrations are measured with a submersible fluorometer. Data loggers control system operations, monitor key variables, and perform discharge calculations. Comparison of discharge from the tracer gauge and from a Cipoletti weir during periods of extensive ice cover indicated that the root‐mean‐square error of the tracer gauge was 0.029 m3 s−1, or 6.3% of average discharge for the study period. The tracer gauge system can provide much more accurate data than is currently available for streams that are strongly ice affected and, thus, could substantially improve management of in‐stream flow protection programs during winter in cold regions. Care must be taken, however, to test for the validity of key assumptions, including complete mixing and conservative behavior of dye, no changes in storage, and no gains or losses of water to or from the stream along the study reach. These assumptions may be tested by measuring flow‐weighted dye concentrations across the stream, performing dye mass balance analyses, and evaluating breakthrough curve behavior.

Combinatorial effects of charge characteristics and hydrophobicity of silk fibroin on the sorption and release of charged dyes.

PubMed

Wongpanit, Panya; Rujiravanit, Ratana

2012-01-01

The present study was designed to examine the influence of the charge characteristics of silk fibroin on the sorption and release of charged dyes by varying the pH values of the sorption and release media as well as types of charged dyes. Negatively charged dyes (phenol red and chromotrope 2R) and positively charged dyes (crystal violet and indoine blue) were used as the model compounds. Silk fibroin films were prepared by using a solution casting technique. The prepared films were then treated with an aqueous methanol solution or annealed with water to control their conformation. The sorption behavior of the model compounds made by the methanol-treated and water-annealed silk fibroin films was investigated. Compared to the water- annealed silk fibroin films, a higher hydrophobicity of the methanol-treated silk fibroin films caused a higher sorption of the hydrophobic dyes. The dye molecules had a fairly high affinity to the silk fibroin film, even though the dye and the matrix possessed the same charge. However, in the presence of two charged groups in a single dye molecule, the electrostatic repulsion become more dominant. Stronger interaction was observed when the charges of the film and the dye were opposite. The results of dye sorption and release experiments showed that the degree of synergism or competition between electrostatic and hydrophobic interactions directly depended on the charges and chemical structure of the dye molecules and the environmental pH conditions of the existing silk fibroin film.

Theoretical study on p-type D-π-A sensitizers with modified π-spacers for dye-sensitized solar cells.

PubMed

Yan, Wen; Chaitanya, Kadali; Sun, Zhi-Dan; Ju, Xue-Hai

2018-02-24

Based on a prototype sensitizer W2, we designed triarylamine-based p-type sensitizers W2-1 to W2-7 that contain modified π-spacers (π'), a π-spacer and two anchors. For W2-1 to W2-4, instead of 2,1,3-benzothiadiazole in W2, thieno[3,4-b]-1,4-dioxin, thiophene, thieno[3,4-c][1,2,5]thiadizole, thiazolo[5,4-d]thiazole are π' and thiophene as π-spacer. For W2-5 to W2-8, π' and π are same, with 2,1,3-benzothiadiazole, thieno[3,4-b]-1,4-dioxin, thieno[3,4-c][1,2,5]thiadiazo, thiazolo[5,4-d]thiazole, respectively, as the π'-spacers. Structure optimization, electronic level and absorption characters were calculated with density functional theory (DFT) and time-dependent DFT (TDDFT) at the CAM-B3LYP/6-311G (d,p). The solvent effect was involved using a polarized continuum model in chloroform. The results showed that the highest occupied molecular orbital and the lowest unoccupied molecular orbital guarantee sufficient hole injection (lower than -0.2 eV), and dye regeneration (lower than -0.2 eV). W2-4 has higher light-harvesting efficiency (LHE) (0.994) and larger overlap with the visible light from 400 nm to 600 nm. Finally, the results suggest that the driving force of hole injection, dye regeneration and charge recombination (ΔG inj , ΔG reg and ΔG CR ) of W2-4 are the best, with more negative ΔG inj (-4.33), ΔG reg (-1.74) and more positive ΔG CR (1.92). Replacing 2,1,3-benzothiadiazole with thiazolo[5,4-d]thiazole as π'-spacers is a effective way to improve the performance of the dyes. An introduction of thiazolo[5,4-d]thiazole group can improve the absorption ability and hinder charge recombination. Graphical abstract Absorption spectra of p-type D-π-A sensitizers with modified π-spacers.

Deep-red to near-infrared fluorescent dyes: Synthesis, photophysical properties, and application in cell imaging

NASA Astrophysics Data System (ADS)

Li, Qi; Liu, Weimin; Wu, Jiasheng; Zhou, Bingjiang; Niu, Guangle; Zhang, Hongyan; Ge, Jiechao; Wang, Pengfei

2016-07-01

More and more attention has been paid to the design of new fluorescent imaging agents with good photostability and water solubility, especially those with emissions in the deep-red and near-infrared regions. In this work, we designed and synthesized four novel fluorescent dyes with deep-red or NIR fluorescence by hybridizing coumarin and pyronin moieties based on our previous work. Introduction of carboxylic acid in the dyes not only imparted the dyes with water solubility but also provided a versatile sensing platform for designing the fluorescent probes and sensors of biomolecules. The photophysical properties of these new dyes were investigated through absorption and fluorescence spectroscopy. Cell imaging experiments showed that esterification products could selectively stain lysosomes with good photostability, thereby indicating that they could be useful in the development of fluorescent probes for bioimaging.

Experimenting with cameraless photography using turmeric and borax: an introduction to photophysics

NASA Astrophysics Data System (ADS)

Appleyard, S. J.

2012-07-01

An alcoholic extract of the spice turmeric can be used to create a light-sensitive dye that can be used to stain paper. On exposure to sunlight, the dyed paper can be used to capture photographic images of flat objects or reproduce existing images through the preferential degradation of the dye in light-exposed areas over a time period of a few hours. The images can be developed and preserved by spraying the exposed paper with a dilute solution of borax, which forms coloured organo-boron complexes that limit further degradation of the dye and enhance the colour of the image. Similar photochemical reactions that lead to the degradation of the turmeric dye can also be used for reducing the organic pollution load in wastewater produced by many industrial processes and in dye-sensitized solar cells for producing electricity.

Nitration of Naphthol: A Laboratory Experiment.

ERIC Educational Resources Information Center

Mowery, Dwight F.

1982-01-01

Products of nitrations, upon distillation or steam distillation, may produce dermatitis in some students. A procedure for nitration of beta-naphthol producing a relatively non-volatile product not purified by steam distillation is described. Nitration of alpha-naphthol by the same procedure yields Martius Yellow dye which dyes wool yellow or…

Synchronized energy and electron transfer processes in covalently linked CdSe-squaraine dye-TiO2 light harvesting assembly.

PubMed

Choi, Hyunbong; Santra, Pralay K; Kamat, Prashant V

2012-06-26

Manipulation of energy and electron transfer processes in a light harvesting assembly is an important criterion to mimic natural photosynthesis. We have now succeeded in sequentially assembling CdSe quantum dot (QD) and squaraine dye (SQSH) on TiO(2) film and couple energy and electron transfer processes to generate photocurrent in a hybrid solar cell. When attached separately, both CdSe QDs and SQSH inject electrons into TiO(2) under visible-near-IR irradiation. However, CdSe QD if linked to TiO(2) with SQSH linker participates in an energy transfer process. The hybrid solar cells prepared with squaraine dye as a linker between CdSe QD and TiO(2) exhibited power conversion efficiency of 3.65% and good stability during illumination with global AM 1.5 solar condition. Transient absorption spectroscopy measurements provided further insight into the energy transfer between excited CdSe QD and SQSH (rate constant of 6.7 × 10(10) s(-1)) and interfacial electron transfer between excited SQSH and TiO(2) (rate constant of 1.2 × 10(11) s(-1)). The synergy of covalently linked semiconductor quantum dots and near-IR absorbing squaraine dye provides new opportunities to harvest photons from selective regions of the solar spectrum in an efficient manner.

Comparison of TiO₂ and ZnO solar cells sensitized with an indoline dye: time-resolved laser spectroscopy studies of partial charge separation processes.

PubMed

Sobuś, Jan; Burdziński, Gotard; Karolczak, Jerzy; Idígoras, Jesús; Anta, Juan A; Ziółek, Marcin

2014-03-11

Time-resolved laser spectroscopy techniques in the time range from femtoseconds to seconds were applied to investigate the charge separation processes in complete dye-sensitized solar cells (DSC) made with iodide/iodine liquid electrolyte and indoline dye D149 interacting with TiO2 or ZnO nanoparticles. The aim of the studies was to explain the differences in the photocurrents of the cells (3-4 times higher for TiO2 than for ZnO ones). Electrochemical impedance spectroscopy and nanosecond flash photolysis studies revealed that the better performance of TiO2 samples is not due to the charge collection and dye regeneration processes. Femtosecond transient absorption results indicated that after first 100 ps the number of photoinduced electrons in the semiconductor is 3 times higher for TiO2 than for ZnO solar cells. Picosecond emission studies showed that the lifetime of the D149 excited state is about 3 times longer for ZnO than for TiO2 samples. Therefore, the results indicate that lower performance of ZnO solar cells is likely due to slower electron injection. The studies show how to correlate the laser spectroscopy methodology with global parameters of the solar cells and should help in better understanding of the behavior of alternative materials for porous electrodes for DSC and related devices.

Fluorescence chemodosimeter for dopamine based on the inner filter effect of the in situ generation of silver nanoparticles and fluorescent dye

NASA Astrophysics Data System (ADS)

Uppa, Yuwapon; Ngamdee, Kessarin; Promarak, Vinich; Ngeontae, Wittaya

2018-07-01

A new strategy for the sensitive and selective detection of dopamine (DA) was proposed. The chemodosimeter design was based on the measurement of the fluorescent quenching of fluorescein dye caused by the in situ generation of silver nanoparticles (AgNPs). The AgNPs can be simply generated by a reaction between DA and Ag+ in the presence of polymethacrylic acid (PMAA). In addition, the generated AgNPs possess the maximum surface plasmon resonance (SPR) at 440 nm and an increase in the SPR intensity with an increasing DA concentration. Basically, fluorescein dye can emit the fluorescent intensity maximum at 513 nm with excitation at 487 nm. Thus, fluorescent quenching was achieved due to an inner filter effect from the overlap between the excitation spectrum of the fluorescein dye and the SPR spectrum of the generated AgNPs. The degree of fluorescent quenching linearly depends on the number of generated AgNPs that can be directly related to the concentration of DA. The proposed chemodosimeter can be used to detect DA in a working linear concentration range of 1.0-5.0 μM at a detection limit of 10.6 nM. This chemodosimeter was successfully applied to determine DA in a real urine sample and a dopamine injection formulation with satisfactory results.

Degradation of immobilized azo dyes by Klebsiella sp. UAP-b5 isolated from maize bioadsorbent.

PubMed

Elizalde-González, M P; Fuentes-Ramírez, L E; Guevara-Villa, M R G

2009-01-30

The degradation of two immobilized dyes by Klebsiella sp. UAP-b5 was studied. In batch experiments, the azo dyestuffs Basic Blue 41 and Reactive Black 5 were immobilized onto corn cobs by adsorption, and the adsorption process was characterized by a pseudo-second-order kinetic equation. Klebsiella sp. UAP-b5 was previously isolated from the corn waste and shown to decolorize these dyes in liquid systems. Here, we demonstrate anaerobic decolorization and reductive biodegradation of these dyes by means of spectrophotometry, HPLC, and IR spectroscopy of the solid waste and desorption solutions. We also demonstrate adsorption of compounds that resemble known degradation products.

Block of the superior cervical ganglion, description of a novel ultrasound-guided technique in human cadavers.

PubMed

Siegenthaler, Andreas; Haug, Matthias; Eichenberger, Urs; Suter, Marc Rene; Moriggl, Bernhard

2013-05-01

Injection of opioids to the superior cervical ganglion (SCG) has been reported to provide pain relief in patients suffering from different kinds of neuropathic facial pain conditions, such as trigeminal neuralgia, postherpetic neuralgia, and atypical facial pain. The classic approach to the SCG is a transoral technique using a so-called "stopper" to prevent accidental carotid artery puncture. The main disadvantage of this technique is that the needle tip is positioned distant from the actual target, possibly impeding successful block of the SCG. A further limitation is that injection of local anesthetics due to potential carotid artery puncture is contraindicated. We hypothesized that the SCG can be identified and blocked using ultrasound imaging, potentially increasing precision of this technique. In this pilot study, 20 US-guided simulated blocks of the SCG were performed in 10 human cadavers in order to determine the accuracy of this novel block technique. After injection of 0.1 mL of dye, the cadavers were dissected to evaluate the needle position and coloring of the SCG. Nineteen of the 20 needle tips were located in or next to the SCG. This corresponded to a simulated block success rate of 95% (95% confidence interval 85-100%). In 17 cases, the SCG was completely colored, and in two cases, the caudal half of the SCG was colored with dye. The anatomical dissections confirmed that our ultrasound-guided approach to the SCG is accurate. Ultrasound could become an attractive alternative to the "blind" transoral technique of SCG blocks. Wiley Periodicals, Inc.

Cellulose nanocrystal-reinforced keratin bioadsorbent for effective removal of dyes from aqueous solution.

PubMed

Song, Kaili; Xu, Helan; Xu, Lan; Xie, Kongliang; Yang, Yiqi

2017-05-01

High-efficiency and recyclable three-dimensional bioadsorbents were prepared by incorporating cellulose nanocrystal (CNC) as reinforcements in keratin sponge matrix to remove dyes from aqueous solution. Adsorption performance of dyes by CNC-reinforced keratin bioadsorbent was improved significantly as a result of adding CNC as filler. Batch adsorption results showed that the adsorption capacities for Reactive Black 5 and Direct Red 80 by the bioadsorbent were 1201 and 1070mgg -1 , respectively. The isotherms and kinetics for adsorption of both dyes on bioadsorbent followed the Langmuir isotherm model and pseudo-second order model, respectively. Desorption and regeneration experiments showed that the removal efficiencies of the bioadsorbent for both dyes could remain above 80% at the fifth recycling cycles. Moreover, the bioadsorbent possessed excellent packed-bed column operation performance. Those results suggested that the adsorbent could be considered as a high-performance and promising candidate for dye wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dye removal from textile industrial effluents by adsorption on exfoliated graphite nanoplatelets: kinetic and equilibrium studies.

PubMed

Carvallho, Marilda N; da Silva, Karolyne S; Sales, Deivson C S; Freire, Eleonora M P L; Sobrinho, Maurício A M; Ghislandi, Marcos G

2016-01-01

The concept of physical adsorption was applied for the removal of direct and reactive blue textile dyes from industrial effluents. Commercial graphite nanoplatelets were used as substrate, and the quality of the material was characterized by atomic force and transmission electron microscopies. Dye/graphite nanoplatelets water solutions were prepared varying their pH and initial dye concentration. Exceptionally high values (beyond 100 mg/L) for adsorptive capacity of graphite nanoplatelets could be achieved without complicated chemical modifications, and equilibrium and kinetic experiments were performed. Our findings were compared with the state of the art, and compared with theoretical models. Agreement between them was satisfactory, and allowed us to propose novel considerations describing the interactions of the dyes and the graphene planar structure. The work highlights the important role of these interactions, which can govern the mobility of the dye molecules and the amount of layers that can be stacked on the graphite nanoplatelets surface.

Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

NASA Astrophysics Data System (ADS)

Albroomi, H. I.; Elsayed, M. A.; Baraka, A.; Abdelmaged, M. A.

2017-07-01

This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m2/g) and pore volume (1.26 cm3/g) can be manufactured from apricot stones by H3PO4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium ( q e) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (Δ G 0), enthalpy (Δ H 0) and entropy (Δ S 0) were determined and the positive value of (Δ H) 78.1 (K J mol-1) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2 ≥ 94.

Circumventing Therapeutic Resistance and the Emergence of Disseminated Breast Cancer Cells Through Non-Invasive Optical Imaging

DTIC Science & Technology

2015-06-01

NOTES 14. ABSTRACT Herein we explore a series of optically distinct near infrared emissive polymersomes (NIREPs; biodegradable polymer vesicles that...characterized into subtypes, without the need for a biopsy. Our system uses non-toxic, biodegradable nanoparticles (called “NIREPs”), which when injected...natural photosynthesis, which exploits NIR-absorbing dyes such as chlorophylls and pheophytins [11]. Relative to the tremendous attention that has

Cell Therapy to Obtain Spinal Fusion

DTIC Science & Technology

2009-07-01

currently developing a near infrared dye IR800 that will enter cells and bind to a peptide moiety known as halo tag (Promega Corp). We believe...modalities. In figure 3A, we injected varying numbers of cells transduced with an adenovirus (5000 vp/cell) possessing the DSRed, GFP, or click ...propose to include peptides essential to the recruitment and migration of osteoprogenitors for bone and cartilage. Selective protease sites will also be

Using Chemistry and Color To Analyze Household Products: A 10-12 Hour Laboratory Project at the General Chemistry Level

NASA Astrophysics Data System (ADS)

Bosma, Wayne B.

1998-02-01

A general chemistry experiment is described in which the students use UV/Visible spectrometry as an analytical tool, for both compound identification and pH measurement. In the first portion of the experiment, the students compare spectra to determine which FD and C dyes are contained in household products. They furthermore use chromatography to separate the dyes in grape Kool-Aid, and analyze the products with the spectrometer. In the second portion of the experiment, the students use Beer's Law to determine the pH of solutions containing an acid/base indicator. The experiments are visually stimulating and provide a solid introduction to spectroscopy and perceived color.

Degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H{sub 2}O{sub 2} process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abidin, Che Zulzikrami Azner, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com; Fahmi, Muhammad Ridwan, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com; Fazara, Md Ali Umi, E-mail: zulzikrami@unimap.edu.my, E-mail: drfahmi@unimap.edu.my, E-mail: umifazara@unimap.edu.my, E-mail: fatinnadhirah89@gmail.com

2014-10-24

In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H{sub 2}O{sub 2} process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV/H{sub 2}O{sub 2} experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV/H{sub 2}O{sub 2} process is meaningful with respectmore » to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H{sub 2}O{sub 2} photolysis.« less

Evaluation of respiratory system in textile-dyeing workers.

PubMed

Salmani Nodoushan, Mojahede; Mehrparvar, Amir Houshang; Loukzadeh, Ziba; Rahimian, Masoud; Ghove Nodoushan, Mohamad Ali; Jafari Nodoushan, Reza

2014-01-01

Despite the presence of many textile and dyeing plants in Iran, we couldn't find similar studies in this country. Forthermore, considering progress in the dyeing process and engineering controls, assessment of respiratory system is important for these workers. The present study was performed to evaluate the respiratory system in dyeing workers. In a cross-sectional study, 101 dyeing workers (all dyeing workers in yazd) and 90 workers without respiratory exposures (control group), were evaluated. A questionnaire was filled for each participant included Venables questionnaire and some other questions about age, work experience, personal or familial history of asthma or atopy, acute and chronic respiratory symptoms; Then spirometry was performed before and after the shift work Results: The frequency of acute and chronic respiratory symptoms was significantly higher among dyeing workers than controls. According to the Venables questionnaire, 11.9% of the dyeing workers suffered from asthma. Means of FVC and FEV1 of pre-shift spirometry were lower than control (p< 0.001). Across-shift spirometry showed significant reduction of FVC (p< 0.001), FEV1 (p< 0.001), FEF25-75% (p= 0.05) and FEF25% (p= 0.007) in dyeing workers compared to the control group. Evaluation of dyeing workers' respiratory system in this study showed that despite development in dyeing processes and engineering controls, workers in this job show more prevalent acute and chronic symptoms, and across-shift changes in spirometric parameters were significantly higher in this work group than the control group. Therefore it is necessary to pay attention to the control of respiratory exposures in this job.

Modeling Polymer Stabilized Nano-scale Zero Valent Iron Transport Experiments in Porous Media to Understand the Transport Behavior

NASA Astrophysics Data System (ADS)

Mondal, P.; Krol, M.; Sleep, B. E.

2015-12-01

A wide variety of groundwater contaminants can be treated with nano-scale zero valent iron (nZVI). However, delivery of nZVI in the subsurface to the treatment zones is challenging as the bare nZVI particles have a higher tendency to agglomerate. The subsurface mobility of nZVI can be enhanced by stabilizing nZVI with polymer, such as carboxymethyl cellulose (CMC). In this study, numerical simulations were conducted to evaluate CMC stabilized nZVI transport behavior in porous media. The numerical simulations were based on a set of laboratory-scale transport experiments that were conducted in a two-dimensional water-saturated glass-walled sandbox (length - 55 cm; height - 45 cm; width - 1.4 cm), uniformly packed with silica sand. In the transport experiments: CMC stabilized nZVI and a non-reactive dye tracer Lissamine Green B (LGB) were used; water specific discharge and CMC concentration were varied; movements of LGB, and CMC-nZVI in the sandbox were tracked using a camera, a light source and a dark box. The concentrations of LGB, CMC, and CMC-nZVI at the sandbox outlet were analyzed. A 2D multiphase flow and transport model was applied to simulate experimental results. The images from LGB dye transport experiments were used to determine the pore water velocities and media permeabilities in various layers in the sand box. These permeability values were used in the subsequent simulations of CMC-nZVI transport. The 2D compositional simulator, modified to include colloid filtration theory (CFT), treated CMC as a solute and nZVI as a colloid. The simulator included composition dependent viscosity to account for CMC injection and mixing, and attachment efficiency as a fitting parameter for nZVI transport modeling. In the experiments, LGB and CMC recoveries were greater than 95%; however, CMC residence time was significantly higher than the LGB residence time and the higher CMC concentration caused higher pressure drops in the sandbox. The nZVI recovery was lower than 40% in all experiments. The simulation results were found to be in good agreement with the experimental results, implying that the compositional simulator including CFT-modified transport equations could be utilized for the estimation of CMC-stabilized nZVI transport in porous media and design of field scale implementations of CMC-nZVI for remediation.

Aggregation behaviour and electron injection/recombination dynamics of symmetrical and unsymmetrical Zn-phthalocyanines on TiO2 film.

PubMed

Ashokkumar, R; Kathiravan, A; Ramamurthy, P

2014-01-21

We have synthesized symmetrical and unsymmetrical Zn-phthalocyanine derivatives (PZnPc, MPZnPc and TPZnPc) for dye sensitized solar cells (DSSCs). Steady state and time-resolved absorption and fluorescence studies were performed in DMF solvent and on a TiO2 surface. The mode and extent of aggregation (H- and J-aggregates) of ZnPc adsorbed on a TiO2 surface were demonstrated. MPZnPc shows both H- and J-aggregation, while TPZnPc shows only H-aggregation. Moreover, the fluorescence of ZnP/TiO2 was completely quenched and this was assigned to electron injection from excited ZnPc to TiO2. Energy level calculations show both ZnPc deriviatives have enough driving force to inject electrons into the conduction band of TiO2. Furthermore, the radical cation of ZnPc was observed in nanosecond transient absorption measurements.

The Dye Sensitized Photoelectrosynthesis Cell (DSPEC) for Solar Water Splitting and CO2 Reduction

NASA Astrophysics Data System (ADS)

Meyer, Thomas; Alibabaei, Leila; Sherman, Benjamin; Sheridan, Matthew; Ashford, Dennis; Lapides, Alex; Brennaman, Kyle; Nayak, Animesh; Roy, Subhangi; Wee, Kyung-Ryang; Gish, Melissa; Meyer, Jerry; Papanikolas, John

The dye-sensitized photoelectrosynthesis cell (DSPEC) integrates molecular level light absorption and catalysis with the bandgap properties of stable oxide materials such as TiO2 and NiO. Excitation of surface-bound chromophores leads to excited state formation and rapid electron or hole injection into the conduction or valence bands of n or p-type oxides. Addition of thin layers of TiO2 or NiO on the surfaces of mesoscopic, nanoparticle films of semiconductor or transparent conducting oxides to give core/shell structures provides a basis for accumulating multiple redox equivalents at catalysts for water oxidation or CO2 reduction. UNC EFRC Center for Solar Fuels, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001011.

Metal-free organic sensitizers for use in water-splitting dye-sensitized photoelectrochemical cells

DOE PAGES

Swierk, John R.; Méndez-Hernández, Dalvin D.; McCool, Nicholas S.; ...

2015-01-12

Solar fuel generation requires the efficient capture and conversion of visible light. In both natural and artificial systems, molecular sensitizers can be tuned to capture, convert, and transfer visible light energy. We demonstrate that a series of metal-free porphyrins can drive photoelectrochemical water splitting under broadband and red light (λ > 590 nm) illumination in a dye-sensitized TiO 2 solar cell. Here, we report the synthesis, spectral, and electrochemical properties of the sensitizers. Despite slow recombination of photoinjected electrons with oxidized porphyrins, photocurrents are low because of low injection yields and slow electron self-exchange between oxidized porphyrins. As a result,more » the free-base porphyrins are stable under conditions of water photoelectrolysis and in some cases photovoltages in excess of 1 V are observed.« less

Decolorization of different textile dyes by Penicillium simplicissimum and toxicity evaluation after fungal treatment

PubMed Central

Bergsten-Torralba, L.R.; Nishikawa, M.M.; Baptista, D.F.; Magalhães, D.P.; da Silva, M.

2009-01-01

The objective of this study was to investigate the capacity of decolorization and detoxification of the textile dyes Reactive Red 198 (RR198), Reactive Blue 214 (RB214), Reactive Blue 21 (RB21) and the mixture of the three dyes (MXD) by Penicillium simplicissimum INCQS 40211. The dye RB21, a phthalocyanine, was totally decolorized in 2 days, and the others, the monoazo RR198, the diazo RB214 and MXD were decolorized after 7 days by P. simplicissimum. Initially the dye decolorization involved dye adsorption by the biomass followed by degradation. The acute toxicity after fungal treatment was monitored with the microcrustacean Daphnia pulex and measured through Effective Concentration 50% (EC50). P. simplicissimum reduced efficiently the toxicity of RB21 from moderately acutely toxic to minor acutely toxic and it also reduced the toxicity of RB214 and MXD, which remained minor acutely toxic. Nevertheless, the fungus increased the toxicity of RR198 despite of the reduction of MXD toxicity, which included this dye. Thus, P. simplicissimum INCQS 40211 was efficient to decolorize different textile dyes and the mixture of them with a significant reduction of their toxicity. In addition this investigation also demonstrated the need of toxicological assays associated to decolorization experiments. PMID:24031428

Solar/UV-induced photocatalytic degradation of three commercial textile dyes.

PubMed

Neppolian, B; Choi, H C; Sakthivel, S; Arabindoo, Banumathi; Murugesan, V

2002-01-28

The photocatalytic degradation of three commercial textile dyes with different structure has been investigated using TiO(2) (Degussa P25) photocatalyst in aqueous solution under solar irradiation. Experiments were conducted to optimise various parameters viz. amount of catalyst, concentration of dye, pH and solar light intensity. Degradation of all the dyes were examined by using chemical oxygen demand (COD) method. The degradation efficiency of the three dyes is as follows: Reactive Yellow 17(RY17) > Reactive Red 2(RR2) > Reactive Blue 4 (RB4), respectively. The experimental results indicate that TiO(2) (Degussa P25) is the best catalyst in comparison with other commercial photocatalysts such as, TiO(2) (Merck), ZnO, ZrO(2), WO(3) and CdS. Though the UV irradiation can efficiently degrade the dyes, naturally abundant solar irradiation is also very effective in the mineralisation of dyes. The comparison between thin-film coating and aqueous slurry method reveals that slurry method is more efficient than coating but the problems of leaching and the requirement of separation can be avoided by using coating technique. These observations indicate that all the three dyes could be degraded completely at different time intervals. Hence, it may be a viable technique for the safe disposal of textile wastewater into the water streams.

Cy3 and Cy5 dyes attached to oligonucleotide terminus stabilize DNA duplexes: predictive thermodynamic model.

PubMed

Moreira, Bernardo G; You, Yong; Owczarzy, Richard

2015-03-01

Cyanine dyes are important chemical modifications of oligonucleotides exhibiting intensive and stable fluorescence at visible light wavelengths. When Cy3 or Cy5 dye is attached to 5' end of a DNA duplex, the dye stacks on the terminal base pair and stabilizes the duplex. Using optical melting experiments, we have determined thermodynamic parameters that can predict the effects of the dyes on duplex stability quantitatively (ΔG°, Tm). Both Cy dyes enhance duplex formation by 1.2 kcal/mol on average, however, this Gibbs energy contribution is sequence-dependent. If the Cy5 is attached to a pyrimidine nucleotide of pyrimidine-purine base pair, the stabilization is larger compared to the attachment to a purine nucleotide. This is likely due to increased stacking interactions of the dye to the purine of the complementary strand. Dangling (unpaired) nucleotides at duplex terminus are also known to enhance duplex stability. Stabilization originated from the Cy dyes is significantly larger than the stabilization due to the presence of dangling nucleotides. If both the dangling base and Cy3 are present, their thermodynamic contributions are approximately additive. New thermodynamic parameters improve predictions of duplex folding, which will help design oligonucleotide sequences for biophysical, biological, engineering, and nanotechnology applications. Copyright © 2015. Published by Elsevier B.V.

A Simple Inexpensive Procedure for Illustrating Some Principles of Tomography

ERIC Educational Resources Information Center

Darvey, Ivan G.

2013-01-01

The experiment proposed here illustrates some concepts of tomography via a qualitative determination of the relative concentration of various dilutions of food dye without "a priori" knowledge of the concentration of each dye mixture. This is performed in a manner analogous to computed tomography (CT) scans. In order to determine the…

Feasibility of surveying pesticide coverage with airborne fluorometer

NASA Technical Reports Server (NTRS)

Stoertz, G. E.; Hemphill, W. R.

1970-01-01

Response of a Fraunhofer line discriminator (FLD) to varying distributions of granulated corncobs stained with varying concentrations of Rhodamine WT dye was tested on the ground and from an H-19 helicopter. The granules are used as a vehicle for airborne emplacement of poison to control fire ants in the eastern and southeastern United States. Test results showed that the granules are detectable by FLD but that the concentration must be too great to be practical with the present apparatus. Possible methods for enhancement of response may include: (1) increasing dye concentration; (2) incorporating with the poisoned granules a second material to carry the dye alone; (3) use of a more strongly fluorescent substance (at 5890 A); (4) modifying the time interval after dyeing, or modifying the method of dyeing; (5) modifying the FLD for greater efficiency, increased field of view or larger optics; or (6) experimenting with laser-stimulated fluorescence.

Automated extraction of direct, reactive, and vat dyes from cellulosic fibers for forensic analysis by capillary electrophoresis.

PubMed

Dockery, C R; Stefan, A R; Nieuwland, A A; Roberson, S N; Baguley, B M; Hendrix, J E; Morgan, S L

2009-08-01

Systematic designed experiments were employed to find the optimum conditions for extraction of direct, reactive, and vat dyes from cotton fibers prior to forensic characterization. Automated microextractions were coupled with measurements of extraction efficiencies on a microplate reader UV-visible spectrophotometer to enable rapid screening of extraction efficiency as a function of solvent composition. Solvent extraction conditions were also developed to be compatible with subsequent forensic characterization of extracted dyes by capillary electrophoresis with UV-visible diode array detection. The capillary electrophoresis electrolyte successfully used in this work consists of 5 mM ammonium acetate in 40:60 acetonitrile-water at pH 9.3, with the addition of sodium dithionite reducing agent to facilitate analysis of vat dyes. The ultimate goal of these research efforts is enhanced discrimination of trace fiber evidence by analysis of extracted dyes.

Delineation of the vitreous and posterior hyaloid using bromophenol blue.

PubMed

Haritoglou, Christos; Strauss, Rupert; Priglinger, Siegfried G; Kreutzer, Thomas; Kampik, Anselm

2008-02-01

To describe visualization of the vitreous and the posterior hyaloid membrane using bromophenol blue during vitrectomy for macular hole and retinal detachment. Six patients with macular holes and four with retinal detachments were included in the study. Before and after surgery, complete clinical examination, including funduscopy and measurements of best-corrected visual acuity and intraocular pressure, was performed. Additional functional tests, such as fluorescein angiography, optical coherence tomography (Stratus OCT; Carl Zeiss Meditec, Jena, Germany, Germany), Goldmann perimetry, and multifocal electroretinography as well as photography of the posterior pole, were performed for macular hole patients. Bromophenol blue was used in concentrations of 0.2%. During macular hole surgery, the dye was injected into the air-filled globe, while during surgery for retinal detachment, the globe was partially filled with perfluorocarbon before dye injection after induction of a posterior vitreous detachment to stain the vitreous peripherally. Bromophenol blue provided sufficient staining of the attached posterior hyaloid membrane and vitreous remnants in the periphery. This was especially helpful for patients in whom a posterior vitreous detachment could not be induced mechanically by suction using the vitrectomy probe alone, as seen in three of six interventions for a macular hole in this series. In addition, staining of the vitreous or vitreous remnants in the periphery and at the vitreous base was seen in all patients and helped to completely remove the vitreous in a controlled fashion. After macular hole surgery, increase of visual acuity from 20/100 (mean) to 20/40 was seen during follow-up up to 6 months. In one case, the hole persisted and required a second operation. Finally, closure of the hole was achieved in all patients. After retinal detachment surgery, reattachment was achieved in all cases. No dye-related adverse events were seen during follow-up as shown by the functional tests (visual acuity measurement, electroretinography, and perimetry) applied. Delineation of the vitreous and the posterior hyaloid using bromophenol blue staining greatly facilitates vitreoretinal procedures. Bromophenol blue appeared to be a very helpful and safe tool to visualize the posterior hyaloid membrane in macular hole surgery and assured its complete separation from the retinal surface. The dye also helped to remove vitreous at the vitreous base during retinal detachment surgery. Therefore, bromophenol blue appears as a very good alternative to triamcinolone, which has been used for this purpose, because the dye has no pharmacological properties and no side effects are likely to occur such as cataract formation and increase in intraocular pressure. Further studies including larger numbers of patients are mandatory.

Biphasic association of T7 RNA polymerase and a nucleotide analogue, cibacron blue as a model to understand the role of initiating nucleotide in the mechanism of enzyme action.

PubMed

Pai, Sudipta; Das, Mili; Banerjee, Rahul; Dasgupta, Dipak

2011-08-01

T7 RNA polymerase (T7 RNAP) is an enzyme that utilizes ribonucleotides to synthesize the nascent RNA chain in a template-dependent manner. Here we have studied the interaction of T7 RNAP with cibacron blue, an anthraquinone monochlorotriazine dye, its effect on the function of the enzyme and the probable mode of binding of the dye. We have used difference absorption spectroscopy and isothermal titration calorimetry to show that the dye binds T7 RNAP in a biphasic manner. The first phase of the binding is characterized by inactivation of the enzyme. The second binding site overlaps with the common substrate-binding site of the enzyme. We have carried out docking experiment to map the binding site of the dye in the promoter bound protein. Competitive displacement of the dye from the high affinity site by labeled GTP and isothermal titration calorimetry of high affinity GTP bound enzyme with the dye suggests a strong correlation between the high affinity dye binding and the high affinity GTP binding in T7 RNAP reported earlier from our laboratory.

Appraisal of marigold flower based lutein as natural colourant for textile dyeing under the influence of gamma radiations

NASA Astrophysics Data System (ADS)

Adeel, Shahid; Gulzar, Tahsin; Azeem, Muhammad; Fazal-ur-Rehman; Saeed, Muhammad; Hanif, Iram; Iqbal, Naeem

2017-01-01

Maintaining colour strength and fastness of the fabrics dyed with natural colourants had been the major constraint of utilizing plant based dyes in modern textile practices. The present study was concerned with the extraction of lutein dye from marigold (Tagetes erecta L.) flowers and role of gamma radiation in improving colour strength and fastness characteristics of the extracted dye. The investigation of dyed fabric in spectraflash showed that gamma ray treatment of 30 kGy was the optimum absorbed dose for surface modification to improve its dye uptake ability. Good colour strength was obtained when irradiated cotton (RC, 30 kGy) was dyed with extract of radiated marigold flower powder (RP) at 70 °C for 85 min, keeping M:L of 1:50 using dye bath of pH 5.0. The results from mordanting experiments revealed that 7% of tannic acid as pre-mordant and 5% of Cu as post-mordant were the best treatments to improve colour strength. It was found that gamma ray induced extraction of lutein from marigold flowers had a potential to be utilized as natural dyes in textile sector to produce yellowish green shades.

Teaching Old Dyes New Tricks: Biological Probes Built from Fluoresceins and Rhodamines.

PubMed

Lavis, Luke D

2017-06-20

Small-molecule fluorophores, such as fluorescein and rhodamine derivatives, are critical tools in modern biochemical and biological research. The field of chemical dyes is old; colored molecules were first discovered in the 1800s, and the fluorescein and rhodamine scaffolds have been known for over a century. Nevertheless, there has been a renaissance in using these dyes to create tools for biochemistry and biology. The application of modern chemistry, biochemistry, molecular genetics, and optical physics to these old structures enables and drives the development of novel, sophisticated fluorescent dyes. This critical review focuses on an important example of chemical biology-the melding of old and new chemical knowledge-leading to useful molecules for advanced biochemical and biological experiments.

Diffuse Reflectance FT-IR Of Surface Modified Kevlar

NASA Astrophysics Data System (ADS)

Benrashid, R.; Tesoro, G.; McKenzie, M. T., Jr.

1989-12-01

Diffuse reflectance FT-IR (DRIFT) has been applied to the characterization of surface modified Kevlar 29 and 49 fibers. The surface modifications include amination and sulfonation. The standard DRIFT experiment has been modified in the manner first described by Koenig et.al. 1 who used a KBR overlayer to enhance surface functional IR bands. The results from the DRIFT experiment have been correlated with those from a standard dye test. The results for degree of modification are in reasonable agreement between the two measurement approaches. However, the dye experiment is time-consuming and inconvenient. DRIFT has been shown to be useful in characterizing modified Kevlar surfaces in as-used conditions.

Cosensitized Porphyrin System for High-Performance Solar Cells with TOF-SIMS Analysis.

PubMed

Wu, Wenjun; Xiang, Huaide; Fan, Wei; Wang, Jinglin; Wang, Haifeng; Hua, Xin; Wang, Zhaohui; Long, Yitao; Tian, He; Zhu, Wei-Hong

2017-05-17

To date, development of organic sensitizers has been predominately focused on light harvesting, highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels, and the electron transferring process. In contrast, their adsorption mode as well as the dynamic loading behavior onto nanoporous TiO 2 is rarely considered. Herein, we have employed the time-of-flight secondary ion mass spectrometry (TOF-SIMS) to gain insight into the competitive dye adsorption mode and kinetics in the cosensitized porphyrin system. Using novel porphyrin dye FW-1 and D-A-π-A featured dye WS-5, the different bond-breaking mode in TOF-SIMS and dynamic dye-loading amount during the coadsorption process are well-compared with two different anchoring groups, such as benzoic acid and cyanoacrylic acid. With the bombardment mode in TOF-SIMS spectra, we have speculated that the cyano group grafts onto nanoporous TiO 2 as tridentate binding for the common anchoring unit of cyanoacrylic acid and confirmed it through extensive first-principles density functional theory calculation by anchoring either the carboxyl or cyano group, which shows that the cyano group can efficiently participate in the adsorption of the WS-5 molecule onto the TiO 2 nanocrystal. The grafting reinforcement interaction between the cyano group and TiO 2 in WS-5 can well-explain the rapid adsorption characteristics. A strong coordinate bond between the lone pair of electrons on the nitrogen or oxygen atom and the Lewis acid sites of TiO 2 can increase electron injection efficiencies with respect to those from the bond between the benzoic acid group and the Brønsted acid sites of the TiO 2 surface. Upon optimization of the coadsorption process with dye WS-5, the photoelectric conversion efficiency based on porphyrin dye FW-1 is increased from 6.14 to 9.72%. The study on the adsorption dynamics of organic sensitizers with TOF-SIMS analysis might provide a new venue for improvement of cosensitized solar cells.

Effect of blue dye guided lymph channel ligation on the surgical morbidity of groin lymphadenectomy for vulval cancer: a feasibility study.

PubMed

Bharathan, Rasiah; Madhuri, Kavitha; Fish, Andrew; Larsen-Disney, Peter; Chatterjee, Jayanthan; Butler-Manuel, Simon; Tailor, Anil; Kehoe, Sean

2018-02-09

Inguinal lymphadenectomy has significant morbidity. Blue dye-guided lymph channel ligation is an effective technique for resolving lymphocele. This was a feasibility study in a preventative setting. Patients with vulval cancer requiring bilateral inguinal lymphadenectomy were recruited. After lymphadenectomy, patent blue V dye was injected and the severed lymph channels leaking blue dye, on the randomly-designated side were ligated. The median age was 72.5 years and the median body mass index was 25. The median lymph node harvest was 18.5. There were no significant surgical procedural differences between the right and the left sides. There was no significant difference between the two arms in terms of the duration or the volume of drainage and post-operative complications. All patients were alive at the follow-up period of 40.5 months. In this feasibility study, blue dye-guided lymph channel ligation did not significantly impact on post-operative outcomes. Impact statement What is already known on this subject? Lymph channel ligation with blue dye-guidance is an effective strategy for managing recalcitrant inguinal lymphocyst. This strategy was prospectively-studied in a small series of patients with non-gynaecological cancers. This particular study by Nakamura et al. ( 2011 ) revealed that such a strategy might be efficacious in reducing wound drain output. What do the results of this study add? Our study is the first study to assess this technique exclusively in vulval cancer. Blue dye-guided lymph channel ligation at the time of inguinal lymphadenectomy does not appear to reduce wound drainage. However, this study suggests that primary lymphocyst predominantly results from inflammatory exudates, whereas persistent secondary lymphocysts are likely to result from lymphorrhoea. What are the implications of these findings for clinical practice and/or further research? Future studies, which aim to reduce the morbidity of open inguinal lymphadenectomy, should employ a composite strategy to reduce inflammatory secretions. In addition, a biochemical and cytological analysis on lymphocysts at various time points should be performed to characterise the natural history of groin lymphocysts.

A comparative study of dietary curcumin, nanocurcumin, and other classical amyloid-binding dyes for labeling and imaging of amyloid plaques in brain tissue of 5×-familial Alzheimer's disease mice.

PubMed

Maiti, Panchanan; Hall, Tia C; Paladugu, Leela; Kolli, Nivya; Learman, Cameron; Rossignol, Julien; Dunbar, Gary L

2016-11-01

Deposition of amyloid beta protein (Aβ) is a key component in the pathogenesis of Alzheimer's disease (AD). As an anti-amyloid natural polyphenol, curcumin (Cur) has been used as a therapy for AD. Its fluorescent activity, preferential binding to Aβ, as well as structural similarities with other traditional amyloid-binding dyes, make it a promising candidate for labeling and imaging of Aβ plaques in vivo. The present study was designed to test whether dietary Cur and nanocurcumin (NC) provide more sensitivity for labeling and imaging of Aβ plaques in brain tissues from the 5×-familial AD (5×FAD) mice than the classical Aβ-binding dyes, such as Congo red and Thioflavin-S. These comparisons were made in postmortem brain tissues from the 5×FAD mice. We observed that Cur and NC labeled Aβ plaques to the same degree as Aβ-specific antibody and to a greater extent than those of the classical amyloid-binding dyes. Cur and NC also labeled Aβ plaques in 5×FAD brain tissues when injected intraperitoneally. Nanomolar concentrations of Cur or NC are sufficient for labeling and imaging of Aβ plaques in 5×FAD brain tissue. Cur and NC also labeled different types of Aβ plaques, including core, neuritic, diffuse, and burned-out, to a greater degree than other amyloid-binding dyes. Therefore, Cur and or NC can be used as an alternative to Aβ-specific antibody for labeling and imaging of Aβ plaques ex vivo and in vivo. It can provide an easy and inexpensive means of detecting Aβ-plaque load in postmortem brain tissue of animal models of AD after anti-amyloid therapy.

Theoretical characterisation of highly efficient dye-sensitised solar cells

NASA Astrophysics Data System (ADS)

Shalabi, A. S.; El Mahdy, A. M.; Assem, M. M.; Taha, H. O.; Abdel Halim, W. S.

2014-01-01

Molecular electronic structure calculations, employing density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methodologies, have been carried out to improve the performance of the synthesised dye YD2-o-C8 which is characterised by 11.9%-12.7% efficiencies. We aimed to narrow the band gap of YD2-o-C8 to extend the light-harvesting region to near-infrared (NIR). This was done by incorporating Cd instead of Zn onto the porphyrin ring and elongating the length of π-conjugation by adding ethynylene link and anthracene unit, so that the performances of the suggested cells could be expected to exceed the 11.9%-12.7% efficiencies with TiO2, ZnO2, and WO3 oxide electrodes. The effects of modifying the central metal and elongating the length of π-conjugation on cell performance are confirmed in terms of frontier molecular orbital (FMO) energy gaps, density of states (DOS), molecular electrostatic potentials (MEPs), non-linear optical (NLO) properties, ultraviolet-visible (UV-vis) electronic absorption, and 1H nuclear magnetic resonance chemical shifts. Increasing the length of π-conjugation of the D-π-A dyes leads to increasing the DOS near Fermi levels, more active NLO performance, strong response to the external electric field, delocalisation of the negative charges near the anchoring groups, deep electron injection, suppressing macrocycle aggregation, active dye regeneration, and inhibited dye recombination. The calculated band gap/eV of the present DMP-Zn is correlated with the experimental (E1/2(oxidation)-E1/2(reduction)/V) potentials of the identical YD2-o-C8. A co-sensitiser is suggested for NIR sensitisation (550-950 nm) to increase the power-to-conversion efficiency beyond 14%.

Transvaginal Pelvic Floor Muscle Injection Technique: A Cadaver Study.

PubMed

Gupta, Priyanka; Ehlert, Michael; Sirls, Larry T; Peters, Kenneth

Women with pelvic floor dysfunction can have tender areas on vaginal examination, which can be treated with trigger-point injections. There are no publications to evaluate the accuracy of pelvic floor muscle injections. Trigger-point injections were performed on 2 fresh cadaveric pelvises using a curved nasal cannula guide and 7-in spinal needle. This was performed using our standard template of 2 sets of injections at the 1-, 3-, and 5-o'clock positions distally and proximally. The first pelvis was dissected to examine dye penetration. Based on these results, we modified our technique and repeated the injections on the second cadaver. We dissected the second pelvis and compared our findings. The 1-o'clock proximal and distal injections stained the obturator internus and externus near the insertion at the ischiopubic ramus. The 3-o'clock injections stained the midbody of the pubococcygeus and puborectalis. The distal 5-o'clock position was too deep and stained the fat of the ischiorectal space. The proximal 5-o'clock injection stained the area of the pudendal nerve. Our goal at the distal 5-o'clock position was to infuse the iliococcygeus muscle, so we shortened the needle depth from 2 to 1 cm beyond the cannula tip. In our second dissection, the distal 5-o'clock injection again stained only the fat of the ischiorectal space. This is the first study to characterize the distribution of pelvic floor muscle injections in a cadaver model and confirms the ability to deliver medications effectively to the pelvic floor muscles.

Tracer-monitored flow titrations.

PubMed

Sasaki, Milton K; Rocha, Diogo L; Rocha, Fábio R P; Zagatto, Elias A G

2016-01-01

The feasibility of implementing tracer-monitored titrations in a flow system is demonstrated. A dye tracer is used to estimate the instant sample and titrant volumetric fractions without the need for volume, mass or peak width measurements. The approach was applied to spectrophotometric flow titrations involving variations of sample and titrant flow-rates (i.e. triangle programmed technique) or concentration gradients established along the sample zone (i.e. flow injection system). Both strategies required simultaneous monitoring of two absorbing species, namely the titration indicator and the dye tracer. Mixing conditions were improved by placing a chamber with mechanical stirring in the analytical path aiming at to minimize diffusional effects. Unlike most of flow-based titrations, the innovation is considered as a true titration, as it does not require a calibration curve thus complying with IUPAC definition. As an application, acidity evaluation in vinegars involving titration with sodium hydroxide was selected. Phenolphthalein and brilliant blue FCF were used as indicator and dye tracer, respectively. Effects of sample volume, titrand/titrant concentrations and flow rates were investigated aiming at improved accuracy and precision. Results were reliable and in agreement with those obtained by a reference titration procedure. Copyright © 2015 Elsevier B.V. All rights reserved.

In Vivo Dual Fluorescence Imaging to Detect Joint Destruction.

PubMed

Cho, Hongsik; Bhatti, Fazal-Ur-Rehman; Lee, Sangmin; Brand, David D; Yi, Ae-Kyung; Hasty, Karen A

2016-10-01

Diagnosis of cartilage damage in early stages of arthritis is vital to impede the progression of disease. In this regard, considerable progress has been made in near-infrared fluorescence (NIRF) optical imaging technique. Arthritis can develop due to various mechanisms but one of the main contributors is the production of matrix metalloproteinases (MMPs), enzymes that can degrade components of the extracellular matrix. Especially, MMP-1 and MMP-13 have main roles in rheumatoid arthritis and osteoarthritis because they enhance collagen degradation in the process of arthritis. We present here a novel NIRF imaging strategy that can be used to determine the activity of MMPs and cartilage damage simultaneously by detection of exposed type II collagen in cartilage tissue. In this study, retro-orbital injection of mixed fluorescent dyes, MMPSense 750 FAST (MMP750) dye and Alexa Fluor 680 conjugated monoclonal mouse antibody immune-reactive to type II collagen, was administered in the arthritic mice. Both dyes were detected with different intensity according to degree of joint destruction in the animal. Thus, our dual fluorescence imaging method can be used to detect cartilage damage as well as MMP activity simultaneously in early stage arthritis. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

11% efficiency solid-state dye-sensitized solar cells with copper(II/I) hole transport materials

PubMed Central

Cao, Yiming; Saygili, Yasemin; Ummadisingu, Amita; Teuscher, Joël; Luo, Jingshan; Pellet, Norman; Giordano, Fabrizio; Zakeeruddin, Shaik Mohammed; Moser, Jacques -E.; Freitag, Marina; Hagfeldt, Anders; Grätzel, Michael

2017-01-01

Solid-state dye-sensitized solar cells currently suffer from issues such as inadequate nanopore filling, low conductivity and crystallization of hole-transport materials infiltrated in the mesoscopic TiO2 scaffolds, leading to low performances. Here we report a record 11% stable solid-state dye-sensitized solar cell under standard air mass 1.5 global using a hole-transport material composed of a blend of [Cu (4,4′,6,6′-tetramethyl-2,2′-bipyridine)2](bis(trifluoromethylsulfonyl)imide)2 and [Cu (4,4′,6,6′-tetramethyl-2,2′-bipyridine)2](bis(trifluoromethylsulfonyl)imide). The amorphous Cu(II/I) conductors that conduct holes by rapid hopping infiltrated in a 6.5 μm-thick mesoscopic TiO2 scaffold are crucial for achieving such high efficiency. Using time-resolved laser photolysis, we determine the time constants for electron injection from the photoexcited sensitizers Y123 into the TiO2 and regeneration of the Y123 by Cu(I) to be 25 ps and 3.2 μs, respectively. Our work will foster the development of low-cost solid-state photovoltaic based on transition metal complexes as hole conductors. PMID:28598436

Evaluation of Resuscitation Fluids on Endothelial Glycocalyx, Venular Blood Flow, and Coagulation Function After Hemorrhagic Shock in Rats

DTIC Science & Technology

2013-10-01

thrombin inhibition, leading to coagulopathy. Using intravital microscopy, we have obtained direct in vivo data showing glycocalyx thickness reduction...collected in 3.2% citrate for coagulation assays (ROTEM, TEM Innovations GmbH, Munich, Germany). Intravital Microscopy The system described in detail...microscopic fields containing venules were randomly selected. The first dye (TR-Dx70) was injected 5 min before baseline. Image sequences of

Short Time Exposure (STE) test in conjunction with Bovine Corneal Opacity and Permeability (BCOP) assay including histopathology to evaluate correspondence with the Globally Harmonized System (GHS) eye irritation classification of textile dyes.

PubMed

Oliveira, Gisele Augusto Rodrigues; Ducas, Rafael do Nascimento; Teixeira, Gabriel Campos; Batista, Aline Carvalho; Oliveira, Danielle Palma; Valadares, Marize Campos

2015-09-01

Eye irritation evaluation is mandatory for predicting health risks in consumers exposed to textile dyes. The two dyes, Reactive Orange 16 (RO16) and Reactive Green 19 (RG19) are classified as Category 2A (irritating to eyes) based on the UN Globally Harmonized System for classification (UN GHS), according to the Draize test. On the other hand, animal welfare considerations and the enforcement of a new regulation in the EU are drawing much attention in reducing or replacing animal experiments with alternative methods. This study evaluated the eye irritation of the two dyes RO16 and RG19 by combining the Short Time Exposure (STE) and the Bovine Corneal Opacity and Permeability (BCOP) assays and then comparing them with in vivo data from the GHS classification. The STE test (first level screening) categorized both dyes as GHS Category 1 (severe irritant). In the BCOP, dye RG19 was also classified as GHS Category 1 while dye RO16 was classified as GHS no prediction can be made. Both dyes caused damage to the corneal tissue as confirmed by histopathological analysis. Our findings demonstrated that the STE test did not contribute to arriving at a better conclusion about the eye irritation potential of the dyes when used in conjunction with the BCOP test. Adding the histopathology to the BCOP test could be an appropriate tool for a more meaningful prediction of the eye irritation potential of dyes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detection of intramyocardially injected DiR-labeled mesenchymal stem cells by optical and optoacoustic tomography.

PubMed

Berninger, Markus T; Mohajerani, Pouyan; Wildgruber, Moritz; Beziere, Nicolas; Kimm, Melanie A; Ma, Xiaopeng; Haller, Bernhard; Fleming, Megan J; Vogt, Stephan; Anton, Martina; Imhoff, Andreas B; Ntziachristos, Vasilis; Meier, Reinhard; Henning, Tobias D

2017-06-01

The distribution of intramyocardially injected rabbit MSCs, labeled with the near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo-cyanine-iodide (DiR) using hybrid Fluorescence Molecular Tomography-X-ray Computed Tomography (FMT-XCT) and Multispectral Optoacoustic Tomography (MSOT) imaging technologies, was investigated. Viability and induction of apoptosis of DiR labeled MSCs were assessed by XTT- and Caspase-3/-7-testing in vitro . 2 × 10 6 , 2 × 10 5 and 2 × 10 4 MSCs labeled with 5 and 10 μg DiR/ml were injected into fresh frozen rabbit hearts. FMT-XCT, MSOT and fluorescence cryosection imaging were performed. Concentrations up to 10 μg DiR/ml did not cause apoptosis in vitro (p > 0.05). FMT and MSOT imaging of labeled MSCs led to a strong signal. The imaging modalities highlighted a difference in cell distribution and concentration correlated to the number of injected cells. Ex-vivo cryosectioning confirmed the molecular fluorescence signal. FMT and MSOT are sensitive imaging techniques offering high-anatomic resolution in terms of detection and distribution of intramyocardially injected stem cells in a rabbit model.

[Sentinel node detection using optonuclear probe (gamma and fluorescence) after green indocyanine and radio-isotope injections].

PubMed

Poumellec, M-A; Dejode, M; Figl, A; Darcourt, J; Haudebourg, J; Sabah, Y; Voury, A; Martaens, A; Barranger, E

2016-04-01

Assess the biopsy's feasibility of the sentinel lymph node biopsy (SLNB) using optonuclear probe after of indocyanine green (ICG) and radio-isotope (RI) injections. Twenty-one patients with a localized breast cancer and unsuspicious axillary nodes underwent a SLNB after both injections of ICG and radio-isotope. One or more SLN were identified on the 21 patients (identification rate of 100%). The median number SLN was 2 (1-3). Twenty SLN were both radio-actives and fluorescents (54.1%), 11 fluorescent only (29.7%) and 6 were only radio-actives (16.2%). Seven patients had a metastatic SLN (8 SLN overall). Among them, only one had a micrometastasic SLN, 5 others had a macrometastatic SLN and one patient had two macrometastatic SLNs. Among the 8 metastatic SLN, 5 were both fluorescent and radioactive, 2 were only fluorescent and 1 was only radioactive. Detection SLN using optonuclear probe after indocyanine green and radio-isotope injections is effective and could be, after validation by randomized trial, a reliable alternative to the blue dye injection for teams who consider that combined detection as the reference. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Influence of pH for the determination of serum albumin by a dye-binding method in the presence of a detergent.

PubMed

Suzuki, Yuji

2008-08-01

In the dye-binding method, the absorbance increase caused by a protein error of a pH indicator is observed only in a restricted pH range. However, this pH range in the presence of a detergent has not yet been examined. Thus, the author investigated the pH (pH(UL)) where the absorbance increase becomes zero by a calculation based on the chemical equilibrium of a protein error of a pH indicator, and by experiments using four sulfonephthalein dyes. The pH(UL) value changed only with the detergent concentration, but did not change at all due to the dye, buffer solution or protein concentrations. Although the pH(UL) value was different according to the kind of dye used, it correlated well with the pK(D) values (dissociation constant) of BPB, BCG, BCP and BTB. The characteristics of pH(UL) in the reactions of the four dyes indicated good agreement with that obtained by a calculation.

Efficiencies of Dye-Sensitized Solar Cells using Ferritin-Encapsulated Quantum Dots with Various Staining Methods

NASA Astrophysics Data System (ADS)

Perez, Luis

Dye-sensitized solar cells (DSSC) have the potential to replace traditional and cost-inefficient crystalline silicon or ruthenium solar cells. This can only be accomplished by optimizing DSSC's energy efficiency. One of the major components in a dye-sensitized solar cell is the porous layer of titanium dioxide. This layer is coated with a molecular dye that absorbs sunlight. The research conducted for this paper focuses on the different methods used to dye the porous TiO2 layer with ferritin-encapsulated quantum dots. Multiple anodes were dyed using a method known as SILAR which involves deposition through alternate immersion in two different solutions. The efficiencies of DSSCs with ferritin-encapsulated lead sulfide dye deposited using SILAR were subsequently compared against the efficiencies produced by cells using the traditional immersion method. It was concluded that both methods resulted in similar efficiencies (? .074%) however, the SILAR method dyed the TiO2 coating significantly faster than the immersion method. On a related note, our experiments concluded that conducting 2 SILAR cycles yields the highest possible efficiency for this particular binding method. National Science Foundation.

A Rationally Designed, General Strategy for Membrane Orientation of Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes.

PubMed

Kulkarni, Rishikesh U; Yin, Hang; Pourmandi, Narges; James, Feroz; Adil, Maroof M; Schaffer, David V; Wang, Yi; Miller, Evan W

2017-02-17

Voltage imaging with fluorescent dyes offers promise for interrogating the complex roles of membrane potential in coordinating the activity of neurons in the brain. Yet, low sensitivity often limits the broad applicability of optical voltage indicators. In this paper, we use molecular dynamics (MD) simulations to guide the design of new, ultrasensitive fluorescent voltage indicators that use photoinduced electron transfer (PeT) as a voltage-sensing switch. MD simulations predict an approximately 16% increase in voltage sensitivity resulting purely from improved alignment of dye with the membrane. We confirm this theoretical finding by synthesizing 9 new voltage-sensitive (VoltageFluor, or VF) dyes and establishing that all of them display the expected improvement of approximately 19%. This synergistic outworking of theory and experiment enabled computational and theoretical estimation of VF dye orientation in lipid bilayers and has yielded the most sensitive PeT-based VF dye to date. We use this new voltage indicator to monitor voltage spikes in neurons from rat hippocampus and human pluripotent-stem-cell-derived dopaminergic neurons.

Efficiency Improvement of Some Agricultural Residue Modified Materials for Textile Dyes Absorption

NASA Astrophysics Data System (ADS)

Boonsong, P.; Paksamut, J.

2018-03-01

In this work, the adsorption efficiency was investigated of some agricultural residue modified materials as natural bio-adsorbents which were rice straw (Oryza sativa L.) and pineapple leaves (Ananas comosus (L.) Merr.) for the removal of textile dyes. Reactive dyes were used in this research. The improvement procedure of agricultural residue materials properties were alkali-acid modification with sodium hydroxide solution and hydrochloric acid solution. Adsorption performance has been investigated using batch experiments. Investigated adsorption factors consisted of adsorbent dose, contact time, adsorbent materials and pH of solution. The results were found that rice straw had higher adsorption capacity than pineapple leaves. The increasing of adsorption capacity depends on adsorbent dose and contact time. Moreover, the optimum pH for dye adsorption was acidic range because lowering pH increased the positively charges on the adsorbent surface which could be attacked by negatively charge of acid dyes. The agricultural residue modified materials had significant dye removal efficiency which these adsorbents could be used for the treatment of textile effluent in industries.

The toxic effect of different concentrations of povidone iodine on the rabbit's cornea.

PubMed

Jiang, Jin; Wu, Miaoqin; Shen, Ting

2009-01-01

To investigate the effects of polyvinylpyrrolidone (i.e., povidone) iodine (PVP-I) in different concentrations on the rabbit's cornea. PVP-I in various concentrations was instilled into the conjunctival sac and injected into the anterior chamber independently. The toxicity to the cornea was assessed by fluorescence dye, specular microscopy, and corneal pachymetry. After conjunctival sac PVP-I instillation, severe epithelial damage was observed at the concentrations of 5.0% and 2.5%. After anterior chamber PVP-I injection, significant corneal edema was observed at the concentrations of 2.0% and 1.5%. It can be safe and feasible to use 0.5% or 1.0% concentrations of PVP-I in conjunctival sac instillation for preoperative antisepsis.

A physical model of ice sheet response to changes in subglacial hydrology

NASA Astrophysics Data System (ADS)

Andrews, L. C.; Catania, G. A.; Buttles, J. L.; Andrews, A.; Markowski, M.

2010-12-01

Using a physical ice sheet model, we investigate the degree to which motion is controlled by local loss of basal traction versus longitudinal coupling during diurnal, seasonal, and event-type water pulses. Our model can be used to reproduce the spatial pattern and magnitude of ice surface displacements and can aid in the interpretation of ground-based GPS measurements, as it eliminates many of the complicating factors influencing surface velocity measurements. This model consists of a 3 x 1.5 meter plastic box with a grid of holes on the bed used to inject water directly between the interface of the box and a silicone polymer. Water flow is visualized using a colored dye. The polymer response to perturbations in water flow is measured by tracking surface markers through a series of overhead images. We report on a suite of experiments that explore the relationship between water discharge, basal traction, and surface displacements and compare our results to ground-based GPS measurements from a transect in western Greenland.

Human factors in equipment development for the Space Shuttle - A study of the general purpose work station

NASA Technical Reports Server (NTRS)

Junge, M. K.; Giacomi, M. J.

1981-01-01

The results of a human factors test to assay the suitability of a prototype general purpose work station (GPWS) for biosciences experiments on the fourth Spacelab mission are reported. The evaluation was performed to verify that users of the GPWS would optimally interact with the GPWS configuration and instrumentation. Six male subjects sat on stools positioned to allow assimilation of the zero-g body posture. Trials were run concerning the operator viewing angles facing the console, the console color, procedures for injecting rates with dye, a rat blood cell count, mouse dissection, squirrel monkey transfer, and plant fixation. The trials were run for several days in order to gage improvement or poor performance conditions. Better access to the work surface was found necessary, together with more distinct and better located LEDs, better access window latches, clearer sequences on control buttons, color-coded sequential buttons, and provisions made for an intercom system when operators of the GPWS work in tandem.

The fluorescent tracer experiment on Holiday Beach near Mugu Canyon, Southern California

USGS Publications Warehouse

Kinsman, Nicole; Xu, J. P.

2012-01-01

After revisiting sand tracer techniques originally developed in the 1960s, a range of fluorescent coating formulations were tested in the laboratory. Explicit steps are presented for the preparation of the formulation evaluated to have superior attributes, a thermoplastic pigment/dye in a colloidal mixture with a vinyl chloride/vinyl acetate copolymer. In September 2010, 0.59 cubic meters of fluorescent tracer material was injected into the littoral zone about 4 kilometers upcoast of Mugu submarine canyon in California. The movement of tracer was monitored in three dimensions over the course of 4 days using manual and automated techniques. Detailed observations of the tracer's behavior in the coastal zone indicate that this tracer successfully mimicked the native beach sand and similar methods could be used to validate models of tracer movement in this type of environment. Recommendations including how to time successful tracer studies and how to scale the field of view of automated camera systems are presented along with the advantages and disadvantages of the described tracer methodology.

Curcumin-sensitized TiO2 for enhanced photodegradation of dyes under visible light

NASA Astrophysics Data System (ADS)

Buddee, Supat; Wongnawa, Sumpun; Sriprang, Pimpaporn; Sriwong, Chaval

2014-04-01

Curcumin was coated on P25 TiO2 by using impregnation method from freshly prepared curcumin solution. The resulting products (Cur-TiO2-P25) was studied by several techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier-transformed infrared spectroscopy, specific surface area by the Brunauer-Emmett-Teller method, and UV-Vis diffused reflectance spectroscopy. Experimental results revealed that impregnation of curcumin at 0.5, 3, 5, and 7 wt% did not affect the native phase of anatase and rutile in P25 significantly, however, it caused red shift of absorption onset in all curcumin-coated samples. The Cur-TiO2-P25 showed enhanced adsorption efficiency and increased photocatalytic activity under visible light with optimal result at 5 wt% curcumin content. Commercial anatase and rutile coated with curcumin (Cur-TiO2-an and Cur-TiO2-ru) were also prepared by the same method for the use in comparative studies of photodegradation of dyes. Cur-TiO2-an and Cur-TiO2-ru were also characterized with some selected equipment above but not as extensively as the Cur-TiO2-P25. Curcumin coating helped improve photocatalytic efficiencies of P25 and anatase but not for rutile. The mechanism of photocatalytic reaction was proposed that under visible light irradiation, curcumin molecule could act as dye sensitizing agent that injected electron into the conduction band of TiO2 leading to photodegradation of dyes.

A novel bubble-forming material for preparing hydrophobic-agent-loaded bubbles with theranostic functionality.

PubMed

Yang, Pei-Sin; Tung, Fu-I; Chen, Hsiao-Ping; Liu, Tse-Ying; Lin, Yi-Ying

2014-08-01

In the present study, a new bubble-forming material (carboxymethyl hexanoyl chitosan, CHC), together with superparamagnetic iron oxide (SPIO) nanoparticles, was employed to prepare image-guided bubbles for efficiently encapsulating and delivering hydrophobic agents to kill tumor cells. The results showed that CHC could be used for preparing not only micronized bubbles (CHC/SPIO MBs) to exhibit ultrasound imaging functionality but also nanosized bubbles (CHC/SPIO NBs) to exhibit magnetic resonance T2 image contrast. It was found that the amounts of SPIO nanoparticles and hexane during preparation process were the key factors to obtaining CHC/SPIO NBs. Most importantly, under in vitro cell culture conditions with the same amount of camptothecin (CPT) and therapeutic sonication, CPT-loaded CHC/SPIO NBs demonstrated more significant transcellular delivery and cytotoxicity than free CPT. Subsequently, an intratumoral injection was proposed for the in vivo administration of hydrophobic-agent-loaded CHC/SPIO NBs. After injection, the distribution of a hydrophobic dye (DiR, an agent with near-infrared (NIR) fluorescence used as a model drug) released from the CHC/SPIO NBs was tracked by an NIR imaging technique. A significant tumor-specific accumulation was observed in the mouse that received the DiR-loaded CHC/SPIO NBs; the same was not observed in the mouse that received the free dye (without incorporating with CHC/SPIO NBs). It is expected, in the future, both the dose of the therapeutic agent administered and its side effects can be significantly lowered by using novel CHC/SPIO NBs together with local delivery (intratumoral injection), targeted imaging and enhanced cellular uptake of the drug. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

[Angiography: safety x economy].

PubMed

Torres, Rogil José de Almeida; Muccioli, Cristina; Casella, Antonio Marcelo Barbante; Regonha, Eduardo; Luchini, Andréa; Weiss, Wilma; Frecceiro, Paulo Roberto

2006-01-01

To evaluate the safety, effectiveness, and cost of angiofluoresceinographic examination by using both the least amount of dye as well as digital equipment along with a laser photocopier. Prospective and comparative study carried out in a group of 70 patients, who underwent an angiographic evaluation with a conventional retinographer injecting 5 ml sodium fluorescein at 10% (control group) as well as a group of 70 patients who underwent an angiographic evaluation with a digital retinographer injecting 2 ml fluorescein at 10% (study group). Arterial pressure, heart rate and oximetry were assessed prior to and after the dye injection. Organic reactions related to the examination were reported. Photograph quality as well as cost between the two techniques were compared. Control group patients showed a greater increase in systolic and diastolic arterial pressure. Heart rate, oximetry measurement and adverse reactions did not show any significant statistical differences between both groups. As for the quality of photographs, a better performance was noticed in the control group. As for the cost, the examination carried out in the study group required lower cost and thus saved around 54.8% per examination in relation to the control group. The examination carried out with a lower dose of fluorescein using digital equipment along with a laser photocopier provided greater stability in the systolic and diastolic arterial pressure. However, it did not have any influence on heart rate, oximetry or adverse reactions such as nausea, vomiting, syncope and rashes. The quality of photographs was poor although they enabled diagnosis as well as therapy follow-up for those who carried out the examination. Moreover, economically the above procedure represented a gain of 66.26%, against 25.81% in relation to the conventional equipment.

Sentinel lymph node detection following the hysteroscopic peritumoural injection of 99mTc-labelled albumin nanocolloid in endometrial cancer.

PubMed

Maccauro, Marco; Lucignani, Giovanni; Aliberti, Gianluca; Villano, Carlo; Castellani, Maria Rita; Solima, Eugenio; Bombardieri, Emilio

2005-05-01

The purpose of this study was to assess the feasibility of sentinel lymph node (SLN) detection in endometrial cancer patients with a dual-tracer procedure after hysteroscopic peritumoural injection. Twenty-six women with previously untreated endometrial adenocarcinoma underwent the hysteroscopic injection of 111 MBq 99mTc-Nanocoll and blue dye administered subendometrially around the lesion. On the same day, all 26 patients underwent lymphoscintigraphy, followed 3-4 h later by hysterotomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy. Para-aortic lymphadenectomy was also performed in cases of either serous or papillary carcinoma (n=7/26). All SLNs were removed and examined with haematoxylin and eosin staining and immunohistochemical techniques. The procedure was well tolerated by patients, only two experiencing transient vagal symptoms. The sensitivity of this technique for correct identification of SLNs was 100%. Lymph node metastases were found in 4 out of the 26 patients (15%), bilaterally in the external iliac region (n=1), unilaterally in the external iliac region (n=1), unilaterally in the common iliac region (n=1) and unilaterally in the para-aortic region (n=1). In all four cases, nodal metastases were located within SLNs detected by lymphoscintigraphy. Only 10 of the 26 patients (38%) had significant blue dye staining. All blue-stained SLNs were radioactive. In patients with endometrial cancer, it is feasible to use lymphatic mapping and SLN biopsy to define the topographic distribution of the lymphatic network and also to accurately detect lumbo-aortic and pelvic metastases within SLNs. In the majority of patients with early stage endometrial cancer, this procedure may avoid unnecessary radical pelvic lymphadenectomy. It may also guide para-aortic lymph node dissection on the basis of the SLN status.

Stopped-in-loop flow analysis system for successive determination of trace vanadium and iron in drinking water using their catalytic reactions.

PubMed

Ayala Quezada, Alejandro; Ohara, Keisuke; Ratanawimarnwong, Nuanlaor; Nacapricha, Duangjai; Murakami, Hiroya; Teshima, Norio; Sakai, Tadao

2015-11-01

An automated stopped-in-loop flow analysis (SILFA) system is proposed for the successive catalytic determination of vanadium and iron. The determination of vanadium was based on the p-anisidine oxidation by potassium bromate in the presence of Tiron as an activator to form a reddish dye, which has an absorption maximum at 510 nm. The selectivity of the vanadium determination was greatly improved by adding diphosphate as a masking agent of iron. For the iron determination, an iron-catalyzed oxidative reaction of p-anisidine by hydrogen peroxide with 1,10-phenanthroline as an activator to produce a reddish dye (510 nm) was employed. The SILFA system consisted of two peristaltic pumps, two six-port injection valves, a four-port selection valve, a heater device, a spectrophotometric detector and a data acquisition device. One six-port injection valve was used for the isolation of a mixed solution of standard/sample and reagent to promote each catalytic reaction, and another six-port injection valve was used for switching the reagent for vanadium or iron to achieve selective determination of each analyte. The above mentioned four-port selection valve was used to select standard solutions or sample. These three valves and the two peristaltic pumps were controlled by a built-in programmable logic controller in a touchscreen controller. The obtained results showed that the proposed SILFA monitoring system constituted an effective approach for the selective determination of vanadium and iron. The limits of detection, 0.052 and 0.55 µg L(-1), were obtained for vanadium and iron, respectively. The proposed system was successfully applied to drinking water samples without any preconcentration procedures. Copyright © 2015 Elsevier B.V. All rights reserved.

On-chip Micro- and Nanofluidic Electrokinetic Injection and Separation for PEGylation Analysis

NASA Astrophysics Data System (ADS)

Shelton, Elijah; Baum, Mary; Morse, Dan; Pennathur, Sumita; Pennathur Nanofluidics Laboratory Collaboration; Morse Laboratory Collaboration

2012-11-01

We present an experimental study of micro- and nanofluidic electrokinetic injection and separation in borosilcate channels as a method for characterizing size and zeta potential of biomolecules-specifically polyethlylene glycol (PEG), keyhole limpet hemocyanine (KLH), and pegylated KLH. While pegylation (the conjugation of proteins with PEG) is an established technique for enhancing a protein's therapeutic properties, reliable characterization of these conjugations by traditional analysis techniques (i.e. gel-electrophoresis, zetasizer) remains a challenge. Using a three-step electrokinetic sequence (load, gate, and inject), FITC labeled species and a fluorescein tracer dye are injected into a channel where they separate according to differences in electrophoretic mobility. We find the average absolute mobility of pegylated subunit KLH in 1 micron channels to be 56% that of unpegylated subunit KLH. In a 250 nm channel, we measure a 33% shift in the average absolute mobility of PEG dendrimers as compared to measurements in a 1 micron channel. These results begin to demonstrate how a micro- and nanofluidic-based approach might address the demand for effective and accessible nanoparticle characterization platforms. Supported by the Institute for Collaborative Biotechnologies.

Integrated on-line system for DNA sequencing by capillary electrophoresis: From template to called bases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ton, H.; Yeung, E.S.

1997-02-15

An integrated on-line prototype for coupling a microreactor to capillary electrophoresis for DNA sequencing has been demonstrated. A dye-labeled terminator cycle-sequencing reaction is performed in a fused-silica capillary. Subsequently, the sequencing ladder is directly injected into a size-exclusion chromatographic column operated at nearly 95{degree}C for purification. On-line injection to a capillary for electrophoresis is accomplished at a junction set at nearly 70{degree}C. High temperature at the purification column and injection junction prevents the renaturation of DNA fragments during on-line transfer without affecting the separation. The high solubility of DNA in and the relatively low ionic strength of 1 x TEmore » buffer permit both effective purification and electrokinetic injection of the DNA sample. The system is compatible with highly efficient separations by a replaceable poly(ethylene oxide) polymer solution in uncoated capillary tubes. Future automation and adaptation to a multiple-capillary array system should allow high-speed, high-throughput DNA sequencing from templates to called bases in one step. 32 refs., 5 figs.« less

A survey of the awareness, knowledge and behavior of hair dye use in a korean population with gray hair.

PubMed

Kim, Jung Eun; Jung, Hee Dam; Kang, Hoon

2012-08-01

Gray hair naturally develops in the process of human aging. Many people with gray hair periodically dye their hair. Hair dyeing products are widely used and they can cause adverse effects. Therefore, the user's knowledge and recognition about hair dyeing and related side effects are important. The goal of this study was to lay the foundation for understanding, preventing and treating side effects caused by hair coloring products. We conducted a questionnaire survey for adult males and females aged over 20 who had gray hair. A total of 500 subjects were included in this study and statistical analysis was performed. Large numbers of the people who had experience with hair dye (233 out of 319 people, 73.0%) did not know about the exact brand name of the hair dye product that they were using. Of 319 hair dye users, 23.8% (76 out of 319) people stated that they experienced side effects. Despite the occurrence of side effects from hair dyeing products, it seems they did not realize the seriousness of the side effects or the need for treatment. It is advisable to introduce a system that enables users to become aware of the ingredients and side effects of hair coloring products and give opportunities for users to become aware of the side effects of hair coloring through education, publicity and publication of an informational booklet.

Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

PubMed Central

2012-01-01

Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r2>0.99) and Langmuir (r2>0.99) isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99) and intra-particle diffusion (r2>0.98) models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively. PMID:23369579

Theoretical description of efficiency enhancement in DSSCs sensitized by newly synthesized heteroleptic Ru complexes.

PubMed

Azar, Yavar T; Payami, Mahmoud

2015-11-28

Recently, some new series of heteroleptic ruthenium-based dyes, the so-called RD dyes, were designed and synthesized showing better performances compared to the well-known homoleptic N719. In this work, using the density-functional theory and its time-dependent extension, we have investigated the electronic structure and absorption spectra of these newly synthesized dyes, and compared the results to those of N3 dye to describe the variations of the properties due to the molecular engineering of the ancillary ligand. We have shown that the calculation results of the absorption spectra for these dyes using the PBE0 for the exchange-correlation functional are in better agreement with the experiment than using B3LYP or range-separated CAM-B3LYP. We have also derived a formula based on the DFT and used it to visually describe the level shifts in a solvent. The higher Jsc observed in these new dyes is explained by the fact that here, in contrast to N3, the excitation charge was effectively transferred to the anchoring ligand. Furthermore, we have shown that the difference dipole moment vectors of the ground and excited states can be used to determine the charge-transfer direction in an excitation process. Finally, different electron lifetimes observed in these dyes are explained by investigating the adsorption geometries and the relative orientations of iodine molecules in different "dyeI2" complexes.

Photodegradation of environmental mutagens by visible irradiation in the presence of xanthene dyes as photosensitizers.

PubMed

Odo, Junichi; Torimoto, Sei-ichi; Nakanishi, Suguru; Niitani, Tomoya; Aoki, Hiroyuki; Inoguchi, Masahiko; Yamasaki, Yu

2012-01-01

The photodegradation of environmental mutagens, such as 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAαC), and 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ), was investigated by visible irradiation in the presence of xanthene dyes as photosensitizers. Although the environmental mutagens themselves were very stable during visible irradiation under the conditions in this study, they were effectively photodegraded in the presence of the xanthene dyes (erythrosine, rose bengal, and phloxine). Moreover, photodegradation of the mutagens was further enhanced for xanthene dyes loaded onto a water-soluble diethylaminoethyl (DEAE)-dextran anion-exchanger via ionic interactions (xanthene-dyeDEX). Photodegradation was inhibited by O2 removal from the reaction solution. In ESR spin-trapping experiments using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a trapping reagent, signals characteristic of DMPO-•OH (hydroxyl radical) were observed in the presence of xanthene-dyeDEX. These results suggest that reactive oxygen species derived from O2, such as singlet molecular oxygen (•1O2) and/or •OH, were active participants in photodegradation of the mutagens in the presence of xanthene dyes or xanthene-dyeDEX.

Study of decolorisation of binary dye mixture by response surface methodology.

PubMed

Khamparia, Shraddha; Jaspal, Dipika

2017-10-01

Decolorisation of a complex mixture of two different classes of textile dyes Direct Red 81 (DR81) and Rhodamine B (RHB), simulating one of the most important condition in real textile effluent was investigated onto deoiled Argemone Mexicana seeds (A. Mexicana). The adsorption behaviour of DR81 and RHB dyes was simultaneously analyzed in the mixture using derivative spectrophotometric method. Central composite design (CCD) was employed for designing the experiments for this complex binary mixture where significance of important parameters and possible interactions were analyzed by response surface methodology (RSM). Maximum adsorption of DR81 and RHB by A. Mexicana was obtained at 53 °C after 63.33 min with 0.1 g of adsorbent and 8 × 10 -6  M DR81, 12 × 10 -6  M RHB with composite desirability of 0.99. The predicted values for percentage removal of dyes from the mixture were in good agreement with the experimental values with R 2 > 96% for both the dyes. CCD superimposed RSM confirmed that presence of different dyes in a solution created a competition for the adsorbent sites and hence interaction of dyes was one of the most important factor to be studied to simulate the real effluent. The adsorbent showed remarkable adsorption capacities for both the dyes in the mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clinical effectiveness of the obturator externus muscle injection in chronic pelvic pain patients.

PubMed

Kim, Shin Hyung; Kim, Do Hyeong; Yoon, Duck Mi; Yoon, Kyung Bong

2015-01-01

Because of its anatomical location and function, the obturator externus (OE) muscle can be a source of pain; however, this muscle is understudied as a possible target for therapeutic intervention in pain practice. In this retrospective observational study, we evaluated the clinical effectiveness of the OE muscle injection with a local anesthetic in chronic pelvic pain patients with suspected OE muscle problems. Twenty-three patients with localized tenderness on the inferolateral side of the pubic tubercle accompanied by pain in the groin, anteromedial thigh, or hip were studied. After identifying the OE with contrast dye under fluoroscopic guidance, 5 to 8 mL of 0.3% lidocaine was injected. Pain scores were assessed before and after injection; patient satisfaction was also assessed. Mean pain score decreased by 44.7% (6.6 ± 1.8 to 3.5 ± 0.9, P < 0.001) 2 weeks after OE muscle injection as compared with pain score before injection. In addition, 82% of patients (19 of 23 patients) reported excellent or good satisfaction during 2 weeks after injection. No patients reported complications from OE muscle injection. Fluoroscopy-guided injection of the OE muscle with local anesthetic reduced pain scores and led to a high level of satisfaction at short-term follow-up in patients with suspected OE muscle problem. The results of this study suggest that OE muscle injection may be a valuable therapeutic option for a select group of chronic pelvic pain patients who present with localized tenderness in the OE muscle that is accompanied by groin, anteromedial thigh, or hip pain. © 2013 World Institute of Pain.

Spectral study and protein labeling of inclusion complex between dye and calixarene sulfonate.

PubMed

Fei, Xuening; Zhang, Yong; Zhu, Sen; Liu, Lijuan; Yu, Lu

2013-05-01

The host-guest inclusion complex of calix[6]arene sulfonate (SCA6) with thiazole orange (TO) formed in aqueous solution was studied. Absorption and fluorescence techniques were used for the analysis of this inclusion complex. The addition of calixarene sulfonate leads to a decrease in both absorption and fluorescence intensity of the dye, indicating that the inclusion complex was formed. Simultaneously, the inclusion phenomenon of another cyanine dye, Cy3, with calixarene sulfonate was investigated. The stability constant of the two complexes was determined, and the results were compared. The water solubility of TO dye was increased in the presence of calixarene sulfonate, and further protein labeling experiments suggested that this TO-SCA6 complex can act as a fluorescent probe for labeling of biomolecules.

Removal of Malachite Green Dye by Mangifera indica Seed Kernel Powder

NASA Astrophysics Data System (ADS)

Singh, Dilbagh; Sowmya, V.; Abinandan, S.; Shanthakumar, S.

2017-11-01

In this study, batch experiments were carried out to study the adsorption of Malachite green dye from aqueous solution by Mangifera indica (mango) seed kernel powder. The mango seed kernel powder was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Effect of various parameters including pH, contact time, adsorbent dosage, initial dye concentration and temperature on adsorption capacity of the adsorbent was observed and the optimized condition for maximum dye removal was identified. Maximum percentage removal of 96% was achieved with an adsorption capacity of 22.8 mg/g at pH 6 with an initial concentration of 100 mg/l. The equilibrium data were examined to fit the Langmuir and Freundlich isotherm models. Thermodynamic parameters for the adsorption process were also calculated.

The Interface Between Chemical and Oxide Materials in the DSPEC

NASA Astrophysics Data System (ADS)

Meyer, Thomas; Alibabaei, Leila; Sherman, Benjamin; Sheridan, Matthew; Ashford, Dennis; Lapides, Alex; Brennaman, Kyle; Nayak, Animesh; Roy, Subhangi

Significant challenges exist for both chemical and oxide materials in the Dye Sensitized Photoelectrosynthesis Cell (DSPEC) for water oxidation or CO2 reduction. They arise from light absorption, the energetics of electron or hole injection, the accumulation of multiple redox equivalents at catalysts for water oxidation or water/CO2 reduction in competition with back electron transfer, and sustained, long term performance. These challenges are being met by the use of a variety of chromophores (metal complexes, organic dyes, porphyrins), broad application of nanoparticle mesoscopic oxide films, atomic layer deposition (ALD) to prepare core/shell and stabilizing overlayer structures, and recent advances in the molecular catalysis of water oxidation and CO2 reduction. UNC EFRC Center for Solar Fuels, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001011.

Simultaneous identification of natural dyes in the collection of drawings and maps from The Royal Chancellery Archives in Granada (Spain) by CE.

PubMed

López-Montes, Ana; Blanc García, Rosario; Espejo, Teresa; Huertas-Perez, José F; Navalón, Alberto; Vílchez, José Luis

2007-04-01

A simple and rapid capillary electrophoretic method with UV detection (CE-UV) has been developed for the identification of five natural dyes namely, carmine, indigo, saffron, gamboge and Rubia tinctoria root. The separation was performed in a fused-silica capillary of 64.5 cm length and 50 microm id. The running buffer was 40 mM sodium tetraborate buffer solution (pH 9.25). The applied potential was 30 kV, the temperature was 25 degrees C and detections were performed at 196, 232, 252, 300 and 356 nm. The injections were under pressure of 50 mbar during 13 s. The method was applied to the identification of carminic acid, gambogic acid, crocetin, indigotin, alizarin and purpurin in the collection of drawings and maps at the Royal Chancellery Archives in Granada (Spain). The method was validated by using HPLC as a reference method.

Ultrasound guided transplantation of enriched and cryopreserved spermatogonial cell suspension in goats.

PubMed

Kaul, G; Kaur, J; Rafeeqi, T A

2010-12-01

Spermatogonial stem cells transplantation provides a unique approach for studying spermatogenesis. Initially developed in mice, this technique has now been extended in farm animals and provides an alternative means to preserve valuable male germ line and to produce transgenic animals. The aim of this study was to enrich type A spermatogonial cells amongst the isolated cells from goat testis, to cryopreserve these enriched populations of cells and their subsequent transplantation in unrelated recipient goats under ultrasound guidance. The cells were isolated enzymatically and enriched by differential plating and separation on discontinuous percoll gradient. Ultrasound guided injection of trypan blue dye into rete testis resulted in 20-30% filling of the seminiferous tubules. Prior to transplantation, the cells were labelled with a fluorescent dye to trace donor cells in recipient seminiferous tubules after transplantation. The fluorescent-labelled cells were observed up to 12 weeks after transplantation. © 2009 Blackwell Verlag GmbH.

Visualization studies of turbulent transition flows in a porous medium

NASA Technical Reports Server (NTRS)

Bilardo, V. J.

1983-01-01

Results are reported for flow-visualization studies of the flow regimes of water passing through a porous medium consisting of cylindrical glass and plexiglas rods arranged in a complex and fixed three-dimensional geometry. The Reynolds number (Re) varied from 50 to 700; the flow was visualized by injecting a 5% potassium permanganate dye solution into the pores and photographing the resulting dye streaklines with both a still camera and a movie camera. The results indicate that four distinct flow regimes exist in the porous medium: (1) Darcy or creeping flow up to Re = 3; (2) steady inertia-dominated laminar flow for Re = 3-150; (3) unsteady transitional laminar flow for Re = 150-250; and (4) fully turbulent flow for Re greater than 250. It is concluded that a laminar wake instability mechanism typical of the external flow about bluff bodies may be responsible for the overall transition from laminar to turbulent flow in porous media.

Accuracy of open magnetic resonance imaging for guiding injection of the equine deep digital flexor tendon within the hoof.

PubMed

Groom, Lauren M; White, Nathaniel A; Adams, M Norris; Barrett, Jennifer G

2017-11-01

Lesions of the distal deep digital flexor tendon (DDFT) are frequently diagnosed using MRI in horses with foot pain. Intralesional injection of biologic therapeutics shows promise in tendon healing; however, accurate injection of distal deep digital flexor tendon lesions within the hoof is difficult. The aim of this experimental study was to evaluate accuracy of a technique for injection of the deep digital flexor tendon within the hoof using MRI-guidance, which could be performed in standing patients. We hypothesized that injection of the distal deep digital flexor tendon within the hoof could be accurately guided using open low-field MRI to target either the lateral or medial lobe at a specific location. Ten cadaver limbs were positioned in an open, low-field MRI unit. Each distal deep digital flexor tendon lobe was assigned to have a proximal (adjacent to the proximal aspect of the navicular bursa) or distal (adjacent to the navicular bone) injection. A titanium needle was inserted into each tendon lobe, guided by T1-weighted transverse images acquired simultaneously during injection. Colored dye was injected as a marker and postinjection MRI and gross sections were assessed. The success of injection as evaluated on gross section was 85% (70% proximal, 100% distal). The success of injection as evaluated by MRI was 65% (60% proximal, 70% distal). There was no significant difference between the success of injecting the medial versus lateral lobe. The major limitation of this study was the use of cadaver limbs with normal tendons. The authors conclude that injection of the distal deep digital flexor tendon within the hoof is possible using MRI guidance. © 2017 American College of Veterinary Radiology.

Characterization of different bubble formulations for blood-brain barrier opening using a focused ultrasound system with acoustic feedback control.

PubMed

Bing, Chenchen; Hong, Yu; Hernandez, Christopher; Rich, Megan; Cheng, Bingbing; Munaweera, Imalka; Szczepanski, Debra; Xi, Yin; Bolding, Mark; Exner, Agata; Chopra, Rajiv

2018-05-22

Focused ultrasound combined with bubble-based agents serves as a non-invasive way to open the blood-brain barrier (BBB). Passive acoustic detection was well studied recently to monitor the acoustic emissions induced by the bubbles under ultrasound energy, but the ability to perform reliable BBB opening with a real-time feedback control algorithm has not been fully evaluated. This study focuses on characterizing the acoustic emissions of different types of bubbles: Optison, Definity, and a custom-made nanobubble. Their performance on reliable BBB opening under real-time feedback control based on acoustic detection was evaluated both in-vitro and in-vivo. The experiments were conducted using a 0.5 MHz focused ultrasound transducer with in-vivo focal pressure ranges from 0.1-0.7 MPa. Successful feedback control was achieved with all three agents when combining with infusion injection. Localized opening was confirmed with Evans blue dye leakage. Microscopic images were acquired to review the opening effects. Under similar total gas volume, nanobubble showed a more reliable opening effect compared to Optison and Definity (p < 0.05). The conclusions obtained from this study confirm the possibilities of performing stable opening using a feedback control algorithm combined with infusion injection. It also opens another potential research area of BBB opening using sub-micron bubbles.

Canine adipose-derived stromal cell viability following exposure to synovial fluid from osteoarthritic joints.

PubMed

Kiefer, Kristina M; O'Brien, Timothy D; Pluhar, Elizabeth G; Conzemius, Michael

2015-01-01

Stem cell therapy used in clinical application of osteoarthritis in veterinary medicine typically involves intra-articular injection of the cells, however the effect of an osteoarthritic environment on the fate of the cells has not been investigated. Assess the viability of adipose derived stromal cells following exposure to osteoarthritic joint fluid. Adipose derived stromal cells (ASCs) were derived from falciform adipose tissue of five adult dogs, and osteoarthritic synovial fluid (SF) was obtained from ten patients undergoing surgical intervention on orthopedic diseases with secondary osteoarthritis. Normal synovial fluid was obtained from seven adult dogs from an unrelated study. ASCs were exposed to the following treatment conditions: culture medium, normal SF, osteoarthritic SF, or serial dilutions of 1:1 to 1:10 of osteoarthritic SF with media. Cells were then harvested and assessed for viability using trypan blue dye exclusion. There was no significant difference in the viability of cells in culture medium or normal SF. Significant differences were found between cells exposed to any concentration of osteoarthritic SF and normal SF and between cells exposed to undiluted osteoarthritic SF and all serial dilutions. Subsequent dilutions reduced cytotoxicity. Osteoarthritic synovial fluid in this ex vivo experiment is cytotoxic to ASCs, when compared with normal synovial fluid. Current practice of direct injection of ASCs into osteoarthritic joints should be re-evaluated to determine if alternative means of administration may be more effective.

Nano-Sized Natural Colorants from Rocks and Soils

NASA Astrophysics Data System (ADS)

Ahmad, W. Y. W.; Ruznan, W. S.; Hamid, H. A.; Kadir, M. I. A.; Yusoh, M. K. M.; Ahmad, M. R.

2010-03-01

Colored rocks (lateritic) and soils (shales) are available in abundant all around Malaysia and they are from natural sources. The colorants will be useful if they can be transferred to substrates using dyeing, printing or brushing with acceptable fastness. First of all the rocks need to be crushed into powder form before coloration can take place. The sizes of the colorants particles obtained with coffee grinder were of 7-8 microns. They can be reduced to 3-5 micron using fluidized bed jetmill and to nano sizes with the help of planetary mono mill grinders. The experiment was conducted in both dyeing and printing of textiles using all three sizes (7-8 microns, 3-5 microns and nano sizes) of colorants on silk fabric. The colorants were applied on silk fabrics by dyeing and tie and dye techniques. In addition, the colorants can also be applied by brushing technique as in batik canting or batik block as well as silk screen printing. The evaluations of colored materials were based on the levelness of dyeing, fastness properties (washing, light and rubbing fastness) and color strength. The wash fastness testing shows that all colorants sizes have more or less the same fastness to washing but nano sized colorants produced better uniform dyes distribution (levelness of dyeing) and higher color strength.

Time-resolved fluorescence polarization spectroscopy of visible and near infrared dyes in picosecond dynamics

NASA Astrophysics Data System (ADS)

Pu, Yang; Alfano, Robert R.

2015-03-01

Near-infrared (NIR) dyes absorb and emit light within the range from 700 to 900 nm have several benefits in biological studies for one- and/or two-photon excitation for deeper penetration of tissues. These molecules undergo vibrational and rotational motion in the relaxation of the excited electronic states, Due to the less than ideal anisotropy behavior of NIR dyes stemming from the fluorophores elongated structures and short fluorescence lifetime in picosecond range, no significant efforts have been made to recognize the theory of these dyes in time-resolved polarization dynamics. In this study, the depolarization of the fluorescence due to emission from rotational deactivation in solution will be measured with the excitation of a linearly polarized femtosecond laser pulse and a streak camera. The theory, experiment and application of the ultrafast fluorescence polarization dynamics and anisotropy are illustrated with examples of two of the most important medical based dyes. One is NIR dye, namely Indocyanine Green (ICG) and is compared with Fluorescein which is in visible range with much longer lifetime. A set of first-order linear differential equations was developed to model fluorescence polarization dynamics of NIR dye in picosecond range. Using this model, the important parameters of ultrafast polarization spectroscopy were identified: risetime, initial time, fluorescence lifetime, and rotation times.