Purple Band Research Articles

Tunable photoluminescence and temperature sensing properties of Ce3+, Eu2+ co-doped Ca2-xSrxMgSi2O7 phosphors

A series of Ca2-xSrxMgSi2O7: Ce3+, Eu2+ (x = 0, 0.5, 1, 1.5, 2) phosphors were synthesized on the basis of high temperature solid-state reaction strategy. Its phase composition, optical spectral properties, fluorescence lifetime and temperature sensitivity were investigated in detail. Under excitation at 342 nm, the emission spectra of Ca2MgSi2O7: Ce3+, Eu2+ exhibit a purple emission band (Ce3+ ions) and a green emission band (Eu2+ ions). The emission band of Ce3+ overlaps with the excitation band of Eu2+, indicating that there may be energy transfer (ET) between the two ions. The decreasing fluorescence lifetime of Ce3+ with increasing Eu2+ concentration further proves the existent of ET process in Ca2MgSi2O7: Ce3+, Eu2+ phosphor. In addition, Ca2-xSrxMgSi2O7: Ce3+, Eu2+ solid solution was designed and synthesized by Sr2+ substituting Ca2+. As Sr2+ gradually replaced Ca2+, the blue-shift of Ce3+ and Eu2+emission band were caused by the change of crystal field. With the increase of temperature, the fluorescence intensity of Ce3+ and Eu2+ emission bands decreased slowly and rapidly, respectively. Hence, in the Ce3+/Eu2+ co-activated Ca2-xSrxMgSi2O7 phosphor, Ce3+ ions and Eu2+ ions can be used as fluorescence intensity ratio (FIR) signals. The maximum relative sensitivity can reach 2.43% K−1 (at 293 K) under 342 nm excitation. The above results indicate that Ca2-xSrxMgSi2O7: Ce3+, Eu2+ phosphors are potential candidates for optical thermometer materials.

Synthesis and Analytical Characterization of Gold Nanoparticles using Microwave-Assisted Extraction System and Study their Application in Degradation

Preparation of gold nanoparticles (AuNPs) was done by the addition of tetrachloroaurate (HAuCl4) to dodonaea viscose (L.) leaves watery extract. The procedure was performed in microwave-assisted extraction (MAE). Dodonaea viscose (L.) watery extract functions as a reducing and capping agent to synthesis AuNPs. The gold nanoparticles was identified by the changes in colour from yellow to red –purple, UV-vis spectroscopy, and surface plasmon band at (600 nm). (EDX -FESEM) and TEM instruments were used to investigate the element analysis, distribution of nanoparticles and to calculate their sizes and shapes. Energy dispersive X-ray spectra (EDX) was applied for characterization of gold nanoparticles, the detected percentage of gold nanoparticles was (0.52 wt/wt %). The result from TEM shows the nanoparticles with diameter (6-80 nm) and vary shapes. Furthermore, characterization of nanoparticles was performed before and after the formation of gold nanoparticles using FT-IR. The band appeared at 669 cm-1 indicated the gold nanoparticle formation. The synthesized gold nanoparticles have been used for degradation of 6.6 % methylene blue organic dye pollutant in aqueous solution, and also for degradation of aliphatic hydrocarbons in crude oil. The results of degradation were monitored by GC-MS. The breakage of some organic materials and the appearance of new organic materials with less molecular weight and less abundance were achieved. Through the use of gold nanoparticles, it has been observed that a large number of aliphatic compounds have disappeared, especially those with molecular weights 200-288, the loss in the molecular weight is about 40%.

Ratiometric determination of copper(II) using dually emitting Mn(II)-doped ZnS quantum dots as a fluorescent probe.

A ratiometric probe is described for the fluorometric determination of Cu(II) ions based on their quenching effect on the luminescence of dually-emitting quantum dots (QDs). ZnS QDs were doped with Mn(II) and subsequently modified with mercaptopropionic acid to give the QD probe which consists of a sole fluorophore but hastwo emission peaks (at 430 and 590nm under 310nm excitation, respectively). On addition of Cu(II) ions, the 590nm band is quenched while the 430nm band exhibits a little change. The changes in theintensity ratios of the yellow and the purple bands increases linearly in the 0 to 3.0μM Cu(II) concentration range, and the detection limit reached 14nM. The QD probe was validated and successfully applied to the determination of Cu(II) in spiked real water samples. Graphical abstract Mn-doped ZnS (ZnS:Mn(II)) quantum dots were synthesized with yellow fluorescence. After the modification of 3-mercaptopropionic acid (MPA), ZnS:Mn(II) was transferred to aqueous phase and became MPA modified Mn-doped ZnS (MPA- ZnS:Mn(II)). The fluorescence was changed to purple upon the addition of copper ions because the yellow band was largely quenched while the purple band only changed a little.

Development of a lateral flow immunochromatographic assay for the rapid diagnosis of Orf virus infections

A rapid and simple lateral-flow immunochromatographic assay (LFIA) was developed for the specific detection of Orf virus (ORFV) using two distinct monoclonal antibodies (MAbs: 5A5 and 6F2) against the ORFV ORF011 protein. The MAb 5A5 was conjugated with colloidal gold, and the MAb 6F2 and goat anti-mouse IgG were sprayed onto a nitrocellulose membrane in strips at positions designated test (T) and control (C), respectively. The results showed that samples of ORFV complexed with colloidal gold-conjugated MAb 5A5, were captured by MAb 6F2 at the T line resulting in the appearance of a purple band. When samples did not contain ORFV or when they contained a quantity of ORFV below the detection limit of the test, only the C line was visible. The analysis of sensitivity of the test demonstrated that the lowest detected quantity of ORFV was 2.03×103.0 TCID50/ml. Storage at room temperature for 6 months did not result in the loss of performance of the LFIA test. Using loop-mediated isothermal amplification (LAMP) as a reference test, the relative specificity and sensitivity of the LFIA test were determined to be 100% and 92.1%, respectively. Based on these results, the LFIA test developed may be a suitable tool for rapid on-site testing for ORFV infection.

Photoluminescence Response from the Turkish Dentritic Agates

The three-dimensional photoluminescence emissions between 380 and 800 nm of the dentritic agate with white body color from the Dereyalak-İnönü-Eskişehir (Turkey) region were obtained at the temperatures between 250 and 340 K under 366 nm excitation. The most advantage of three-dimensional photoluminescence graphic in a silica structure is to demonstrate clearly all vibronic structures through temperature increasing on the spectra. Hence, photoluminescence response from the gem-quality material was discussed in relation to chemical impurities of trivalent rare earth elements. In the photoluminescence spectra, two strong and many weaker emission bands became clear at the lower temperature (250 K) conditions. First strong one is the purple band, and the highest emission peak is observed at 394 nm. Second strong one is the red band, and the highest emission peak is observed at 717 nm. The half-width of these main bands is approximately 17–19 nm, and such band's combination is typical for trivalent rare earth elements. Chemical analyses in this study show the abundances of many rare earth elements in the material. In order of abundance, they are yttrium (845 ppm), gadolinium (238 ppm), lutetium (196 ppm), dysprosium (45 ppm), neodymium (41 ppm), promethium (34 ppm), europium (18 ppm), and scandium (3 ppm). However, the two strong emission bands are, of course, due to yttrium and gadolinium ions, respectively. As a result, the intensities of these bands gradually decreased forming a sequence until the temperature of 280 K. Hence, the photoluminescence of the Turkish dentritic agates does not exist at higher temperatures, mainly because of high iron (40.000 ppm) abundance.

Phycobilisome composition in Chondrus crispus (Gigartinales, Rhodophyta) from a wild type strain and its vegetatively derived green mutant

Intact phycobilisomes from a wild-type red Chondrus crispus and its vegetatively derived green mutant were isolated by centrifugation through a discontinuous sucrose density gradient. Pigment composition was subsequently characterized by spectrophotometry. Vegetative thalli of the two strains grown together for six months in the laboratory resulted in different pigment profiles. Two pigmented phycobilisome bands appeared in the sucrose gradient of the wild-type alga, a purple coloured one, and a pink one, whereas only a single blue band appeared in the gradient of the green mutant. Spectrophotometric and fluorescence analyses identified the phycobiliprotein composition of the purple band as the typical phycoerythrin-phycocyanin-allophycocyanin complement in the wild-type, but there was no detectable phycoerythrin present in the blue band of the green mutant. Sodium dodecyl sulphate, preparative polyacrylamide gel electrophoresis analysis confirmed the presence of allophycocyanin subunits in all extracts, but firm evidence of an R-phycoerythrin linker polypeptide in the blue band was missing. These results highlight the ability of C. crispus to adapt to a phycoerythrin deficiency by adjusting light harvesting pigment ratios.

Development of a convenient immunochromatographic strip for the diagnosis of vesicular stomatitis virus serotype Indiana infections

A rapid and simple immunochromatography strip (ICS) test for the specific detection of vesicular stomatitis virus serotype Indiana (VSV-IND) using two distinct monoclonal antibodies MAbs (1A2 and 4C3) against the G protein of VSV-IND was developed. The MAb 1A2 was conjugated with colloidal gold, and the MAb 4C3 and goat anti-mouse IgG were sprayed onto a nitrocellulose membrane in strips at positions designated T and C, respectively. The results showed that samples of VSV-IND combined with CG-MAb 1A2, and that these complexes were captured by MAb 4C3 at the test line (T), resulting in the appearance of a purple band. When samples did not contain VSV-IND or when they contained a quantity of VSV-IND below the detection limit of the test, only the control line (C) was visible. The analysis of the sensitivity of the test demonstrated that the lowest detected quantity of VSV-IND was 1.85×10(3.0)TCID50/ml. Storage of the ICS test at room temperature for 6 months or at 4°C for 12 months did not change their sensitivity and specificity. In clinical trials using RT-PCR as a reference test, the relative specificity and sensitivity of the ICS were determined to be 98.9% and 91.4%, respectively. Based on these results, the ICS test developed may be a suitable tool for rapid on-site testing for VSV-IND infection.

Synthesis, Structure, and Photoluminescent Property of a Novel 2D Silver(I) Polymer Based on Short Ag-Ag Interactions

A new two-dimensional (2D) polymer, [Ag(2-Clnic)]n (2-Clnic = 2-chloronicotinate) (1), has been synthesized and characterized by IR, elemental analysis, single-crystal X-ray diffraction, and luminescence spectroscopy. X-ray crystal analysis reveals that complex 1 is constructed through π-π stacking and Ag…O interactions, which provide important roles in the assembly of intriguing structures and specific photophysical properties. In the solid state at room temperature, 1 is found to be luminescent with a purple emission band at 411 nm upon excitation at 360 nm.

Growth and photoluminescence character research of aluminum nitride nanowires upon carbon foam substrate

To simplify preparation process of AlN/C composite foam, AlN nanomaterials are prepared via double decomposition reaction and then 800℃ annealing process to recrystallize hexagonal AlN (h-AlN) nanowires on carbon foam substrate. Fore the morphology characterization it follows that, h-AlN nanowires with straight cylindrical morphology grow along the [001]direction on carbon microspheres surface and are about 50 nm in diameter and several micrometers in length. Meanwhile, the growth mechanism of nanowire is interpreted as vapor-liquid-solid(VLS) process. The photoluminescence(PL) spectrum of as-prepared sample also researched, and the results show that a sharp photoluminescence peak appears at 423 nm and shifts toward the red side with temperature increasing. The peak is attributed to the transition luminescence, owing to the substitution of C for N impurity energy level. The sample has good PL character in purple light band and is potential to be used the in photodetector field.

Development and preliminary application of an immunochromatographic strip for rapid detection of infection with porcine reproductive and respiratory syndrome virus in swine

A “strip test” to detect porcine reproductive and respiratory syndrome virus (PRRSV) was established using a monoclonal antibody (MAb) 2D7 conjugated with colloidal gold. Two MAbs binding to protein N at different epitopes, 2D7 and 1G7 were obtained. In the test, samples of PRRSV bound to colloidal gold-conjugated MAb 2D7. The complex was then captured by MAb 1G7 at the test line (T) on the nitrocellulose membrane, presenting a purple band. If the sample did not contain PRRSV or if the quantity of PRRSV was less than that required for the kit, only the control line (C), in which goat anti-mouse antibody was added as the capture antibody, was present. Results from the sensitivity test of the kit demonstrated that the lowest detected quantity of PRRSV is 2.9 × 10 3 TCID 50/ml. In clinical trials, the specificity and the sensitivity of this kit are 98.1% and 88.4%, respectively, compared with RT-PCR. Furthermore, this kit was found to be efficient in three areas of China and appears to have better results in practical applications than in empirical studies. In summary, this kit has not only high rates of specificity and sensitivity but also has the beneficial features such as efficiency, convenience and speed.

Three New Distichous-bracted Species ofCalathea(Marantaceae) from Panama

Three species of Calathea G. Mey. with distichous bracts, assigned to Calathea sect. Calathea (Marantaceae), are described as new from Panama: C. carlae H. Kenn., C. chiriquensis H. Kenn., and C. fredgandersii H. Kenn. All three are found in montane wet or cloud forest habitats at middle to higher elevations, 800–1400 m. Calathea carlae also occurs in Costa Rica, while the other two are endemic to Panama. Calathea carlae differs from related species by the leaf length:width ratios of 1.7–2.13:1, cream-colored bracts, claviculate bracteoles, yellow corollas, and yellow or pink-purple staminodes. Calathea chiriquensis is distinguished by the light green bracts, leaf length:width ratios of 1.3–1.56:1, absence of bracteoles, flowers borne singly rather than in pairs, and yellow flowers. Calathea fredgandersii is distinguished by the subround leaf, leaf length:width ratios of 1.15–1.55:1, a purple band along the leaf margin, a deep purple leaf sheath, verruculose petioles, white bracts, membranous bracteoles, white corollas, and white or pale pink to lilac staminodes.

A New Species of Asarum: A. yeonbyeonense M. Kim & S. So

A new species, Asarum yeonbyeonense M. Kim & S. So, is named and described from Mt. Baekdu in Korea. This new species is distinctly different from the related species A. mandshuricum (Maxim.) M. Kim & S. So according to the purple band at the base of the calyx lobes and the thick calyx lobes. In addition, Asarum sieboldii var. viridiluteolum Y. Lee is closely related to A. yeonbyeonense M. Kim & S. So due to its reflexed calyx lobes; however, this variety has green calyx lobes and pubescent petioles. Therefore its scientific name was changed to Asarum yeonbyeonense var. viridiluteolum (Y. Lee) M. Kim & S. So, and its Korean name should be changed into Nokyeonbyeon-Jokdoripul.

EFFECT OF VANADIUM CONTENT ON PHOTOLUMINESCENCE AND MAGNETIC PROPERTIES OF DOPED ZnO THIN FILMS

ZnO : V thin films with different doping concentration (0%, 1.8%, 3.9%, 6.8%, 10%, and 13%) were fabricated by direct current magnetron sputtering. The X-ray diffraction patterns show that the wurzite structure changed with doping concentration. Furthermore, we could not find any vanadium cluster or phase separation in the X-ray diffraction patterns. The photoluminescence of ZnO : V with different vanadium concentration was investigated. The room temperature photoluminescence spectrum indicates that the films have purple band with 370 nm and the bands with 475 and 490 nm. The peak intensity of room temperature photoluminescence spectrum was affected by vanadium contents and its position remained stable. The intensity of band with 370 nm increases with raising the vanadium concentration and then decreases. The hysteresis behavior indicates that films were ferromagnetic at 50 K. Room temperature ferromagnetism was observed for the film with the doping concentration at 6.8%. However, in this case almost no hysteresis is noticeable. The results implied that the doping concentration and crystalline microstructure influence strongly the film's magnetic characteristics. Increasing the vanadium content in the film caused the degradation of the magnetic ordering.

A Study Of The Resistive Forces Provided By Elastic Supplemental Band Resistance During The Back Squat Exercise: A Case Report

The use of elastic bands to supplement traditional plate weight resistance to the back squat has become increasingly popular in weight rooms. By using supplemental elastic bands, a variable resistance is produced. This variable resistance will progressively increase the amount of resistance throughout the range of motion of an exercise that possesses an ascending strength curve. The set-up and technique for using elastic bands has been described in the literature, however, the resistance of the bands during an actual squat has not been measured. The purpose of this study was to measure the actual resistive forces provided by various supplemental elastic bands during the back squat exercise. A secondary purpose was to compare these measured resistive forces with the manufacturers reported values. The subject (height = 1.83 m; weight = 111.4 kg), an experienced weight lifter, was analyzed performing a back squat with supplemental elastic band resistance. Plate weight was set at approximately 50% of the lifters self-reported 1 RM. The elastic bands were looped under the bottom of the power cage and one end threaded back through the other to properly affix the band to the cage. The elastic bands were attached to load cells via a carabiner clip. The load cells were affixed to standard 0.05 m sleeve collars for placement on the barbell. The use of the load cells allowed for the measurement of the resistive forces being provided by the elastic bands throughout the entire squat. The subject performed one set of 3 repetitions with a pair of purple “light” elastic bands and again with a pair of green “average” elastic bands. The pair of light (purple) elastic bands provided an average maximum resistance of 273 N. The average (green) elastic bands provided an average maximum resistance of 405 N. The manufacturer of the elastic bands provides a chart approximating the amount of resistance provided by their bands. They report, depending upon the attachment technique, a single “light” purple band provides up to 222 N of resistance, while a single “average” green band provides up to 334 N of resistance. The resistive forces we reported are the total forces provided by both elastic bands when performing a back squat. Per the manufacturer's guidelines, the resistance provided from a pair of “light” purple bands would be up to 444 N while the resistance provided from a pair of “average” green bands would be up to 668 N. The resistance provided by the elastic bands in our study was only 61% of the manufacturer reported values. The amount of resistance provided by elastic bands should have a linear relationship with the amount they are stretched, the more they are stretched, the more resistance they produce. The resistive force produced when our 1.83 m tall subject completed a parallel depth squat was only 61% of those values reported by the manufacturer. One should expect greater amounts of resistance from a taller individual and less resistance from a shorter individual.

A potassium and cadmium coordination polymer connected by two kinds of coordination modes of 4,5-dicyanoimidazole ligands: Synthesis, crystal structure and fluorescent properties of {[K[Cd(dci)2(H2O)2]6]Cl}n

Abstract A novel heteronuclear cooordination polymer containing potassium and cadmium, {[K[Cd(dci)2(H2O)2]6]Cl}n (1) (Hdci = 4,5-dicyanoimidazole), has been synthesized and characterized with the aid of elemental analysis, fluorescence spectroscopic studies and single-crystal X-ray diffraction. In compound 1, half of dci− anions act as bidentate bridging ligands and the other half act as tridentate bridging ligands. It is through the bridging function of dci− ligands that K(I) and Cd(II) ions are connected and 3D coordination polymer of 1 forms. Solid-state fluorescence measurements reveal that complex 1 can emits strong purple emission band.

Loop mediated isothermal amplification combined with nucleic acid lateral flow strip for diagnosis of cyprinid herpes virus-3

An improved loop mediated isothermal amplification (LAMP) assay for rapid, sensitive and specific detection of cyprinid herpes virus-3 (CyHV-3), also known as koi herpes virus (KHV), was developed. The lower detection limit of the CyHV-3-LAMP assay is 10 fg DNA which equivalent to 30 copies of CyHV-3 genome. Nucleic acid lateral flow assay was used for visual detection of the LAMP products. The LAMP- nucleic acid lateral flow assay relies on DNA hybridization technology and antigen–antibody reactions in combination with LAMP. For application of this assay, the biotinylated LAMP product was hybridized with a FITC-labelled specific probe for 5 min. The resulting DNA complex could be visualised as purple band at the strip test line within 5 min of sample exposure. The nucleic acid lateral flow analysis of the LAMP product was equivalent in sensitivity but more rapid than the conventional agarose gel electrophoresis. The combination of LAMP assay with the nucleic acid lateral flow analysis can simplify the diagnosis and screening of CyHV-3 as it is simple, requires very little training, does not require specialized equipment such as a thermal cycler, the results are read visually with no need to run a gel and has a high sensitivity and specificity.

Upper petal lip colour polymorphism in Collinsia heterophylla (Plantaginaceae): genetic basis within a population and its use as a genetic marker

Understanding the genetics of a polymorphic trait is important to predict its likely evolution. In Collinsia heterophylla, the upper petal lip colour can be either be white or white with a purple band, while the lower petal lip colour is invariably purple. Because the corolla is only partly polymorphic, the polymorphism can not have evolved due to a mutation where a pigment was lost in the entire plant, which is common in other polymorphic species. In a previous study, high frequency of the purple band was found in populations with darker flowers, indicating possible selection for this trait. In this study, I determined inheritance of the colour polymorphism using two populations (one with only white morph and other with both morphs). I conducted experimental crosses within and between floral morphs to determine whether patterns of segregation in offspring conform to single-gene predictions. Data from F1, F2, F3 and backcross progeny are consistent with a genetic model of one major locus with presence of the band being completely dominant, as indicated in earlier studies using distantly related populations. A novel finding in this study was that the two morphs did not show a difference in seed germination frequency or seedling survival. This trait can thus be valuable as a genetic marker. Even though more thorough ecological data are needed to understand the potential selection pressures on upper petal lip colour in C. heterophylla, its simple inheritance may indicate the possibility of fast evolutionary response to selective forces acting on this trait.

Immuno-chromatographic Test-strip for Skin Cathepsin L Analysis

The objective is to develop a methodology to analyze cathepsin L (Cat L) activity derived from the stratum corneum as an index of skin conditions. In this paper, a disposable type immuno-chromatographic test-strip (test-strip) is proposed for Cat L analysis. A fabricated test-strip for Cat L analysis consists of a sample pad, a conjugate pad, a nitrocellulose membrane and absorption pad. After dropping a sample, it was needed 90 s to reach the solution at the test-line on the test-strip. Three min after dropping, a reddish purple colored band was appeared as the test-line. The band visually observed clearly when the concentration of Cat L of the standard solution over 0.01 U/l. It was indicated a possibility of the disposable type immuno-chromatographic test-strip for the analysis of Cat L of skin.

Hydrothermal synthesis and characterization of novel flower-like zinc-doped SnO 2 nanocrystals

Zinc-doped SnO 2 nanocrystals were prepared by a simple hydrothermal process. X-ray diffraction (XRD) patterns show that as-prepared samples are of tetragonal rutile structure of SnO 2. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) characterizations confirm that the morphologies of zinc-doped SnO 2 nanocrystals are “flower”-constructed nanorods. Photoluminescence (PL) measurement of the zinc-doped SnO 2 crystals reveals a purple emission band centered at ∼440 nm. The influences of the hydrothermal reaction temperature, the molar ratio of Zn 2+ and Sn 4+ as well as the concentrations of NaOH have been studied. The possible growth mechanisms of flower-like nanocrystals were discussed.

Low-Temperature Growth and Photoluminescence Property of ZnS Nanoribbons

At a low temperature of 450 degrees C, ZnS nanoribbons have been synthesized on Si and KCl substrates by a simple chemical vapor deposition (CVD) method with a two-temperature-zone furnace. Zinc and sulfur powders are used as sources in the different temperature zones. X-ray diffraction (XRD), selected area electron diffraction (SEAD), and transmission electron microscopy (TEM) analysis show that the ZnS nanoribbons are the wurtzite structure, and there are two types-single-crystal and bicrystal nanoribbons. Photoluminescence (PL) spectrum shows that the spectrum mainly includes two parts: a purple emission band centering at about 390 nm and a blue emission band centering at about 445 nm with a weak green shoulder around 510 nm.