Levels Of Pr3 Research Articles

7876 Complex Complications of Thionamide Therapy in One Patient: Methimazole-Induced Agranulocytosis and PTU-Induced ANCA-Vasculitis

Abstract Disclosure: E. Zweibach: None. A. Chang: None. Introduction: Thionamides, including methimazole and propylthiouracil (PTU), are essential for treating Graves' disease but can cause serious side effects such as agranulocytosis and ANCA-vasculitis. Although agranulocytosis itself is quite uncommon, the incidence of ANCA vasculitis is even more infrequent, making combination of conditions particularly exceptional. We present a unique case of a Graves' disease patient who suffered both complications: agranulocytosis due to methimazole and ANCA vasculitis from PTU, with successful resolution of both the clinical signs and laboratory findings following drug discontinuation. Case: 61-year-old female with a history of Graves' disease previously managed with methimazole but discontinued due to agranulocytosis, presented with lower extremity swelling, atrial fibrillation with RVR, and high output cardiac failure. Laboratory tests showed hyperthyroidism (TSH 0.008, Free T4 3.07), leading to a diagnosis of thyroid storm. Patient was started on PTU inpatient and discharged with this medication to home. Eight months later, the patient developed alarming signs including gross hematuria, oral ulcers, widespread muscle pain, found to have AKI with Cr of 2.79 and hospitalized for further eval. While hospitalized, the patient was found to have a range of complications including leukopenia with normal granulocyte count, anemia, AKI, proteinuria, and microscopic hematuria. Rheumatological evaluation showed +ANA and a high ANCA titer >1:1280, along with elevated levels of MPO and PR-3, and reduced complement levels. These symptoms and laboratory findings led to a diagnosis of ANCA vasculitis induced by PTU, resulting in the cessation of this medication. Following the discontinuation of PTU there was a notable improvement with normalization of serum Cr and resolution of proteinuria within 1.5 months. Concurrently, MPO and PR-3 levels began to decrease, and her hematological abnormalities resolved. During this period, her Free T4 levels gradually increased, leading to the administration of radioactive iodine for the treatment of her Graves' disease. Discussion: This case underscores the complexities in treating a patient with Graves' disease highlighting the unpredictable and severe side effects of antithyroid drugs like agranulocytosis and ANCA vasculitis. We report the first documented case of sequential thionamide-induced complications: agranulocytosis with methimazole, followed by ANCA vasculitis with propylthiouracil. Although both can arise from immune responses to these medications, they are distinct in their pathophysiology and are not associated with one another. The unpredictable nature of these side effects complicates prevention. Educating patients to promptly report any unusual symptoms and immediate medical intervention with drug discontinuation are key to managing these adverse reactions effectively. Presentation: 6/1/2024

Challenges in Managing Newly Diagnosed Granulomatosis With Polyangiitis and Concurrent Respiratory Infections: A Retrospective Case Series.

Granulomatosis with polyangiitis (GPA), formerly termed Wegener's granulomatosis, is an autoimmune disease marked by necrotizing granulomatous inflammation and vasculitis affecting small-sized vessels. It commonly impacts the renal and respiratory systems. This retrospective case series sampling conductedin a tertiary care hospital between May 2023 and April 2024 examined six newly diagnosed GPA patients who wereproteinase 3 cytoplasmic-antinuclear cytoplasmic antibody (PR3 c-ANCA) positive and had concurrent respiratory infections. None of them had any prior immunosuppressive conditions.The age range was 18-47 years with a mean of 35.0 (standard deviation: 11.83). All the patients had pneumonia (N=6, 100%). Out of all, five hadbacterial pneumonia (N=5, 83.3%) and one had tuberculous pneumonia (N=1, 16.7%). A high levelof PR3 c-ANCA (>150 RU/mL) was noted in four patients (N=4, 66.7%).Common symptoms included dry cough (N=5, 83.3%), loss of weight and appetite(N=2, 33.3%), and fever (N=2, 33.3%). Three patients had otitis mediaand/or nasal polyposis (N=3, 50%). Two patients (N=2, 33.3%) with life-threatening organ dysfunction were given concurrent antibiotics and steroids; the antibiotics were later modified based on culture and sensitivity results. One of these patients received antituberculosis therapy as Mycobacterium tuberculosis (MTB) was detected after 27 days of incubation in mycobacterial growth indicator tube broth. The remaining four patients (N=4, 66.7%)receivedantibiotics initially for 5-7 days until clinical resolution of pneumonia. Ultimately, they all showed clinical and radiological resolution (N=6, 100%) within 3-6 months of treatment. The patients exhibited constitutional symptoms such as fever and weight loss; lower airway disease symptoms including dry cough and hemoptysis; nasal and ear disease symptoms like epistaxis, ear pain, and ear discharge; and a renal disease symptom, hematuria.Computed tomography of the thorax revealed bilateral consolidations, most of which were cavitating. Bronchoalveolar lavagecultures grew Escherichia coli, Burkholderia cepacia, Pseudomonas aeruginosa, Klebsiella pneumoniae, and MTB, whereas pus swab cultures from otitis media grew Pseudomonas aeruginosa, Staphylococcus aureus,and coagulase-negative staphylococci. This study highlights the therapeutic challenges of GPA complicated by concurrent infections. Patients exhibited typical GPA signs, confirmed by PR3 c-ANCA levels. Concurrent infections require cautious antibiotic treatment before starting immunosuppressive therapy, except in life-threatening organ dysfunction. A unique case presented with both tuberculosis and GPA. Tailored treatment regimens combining antibiotics and immunosuppressives, including corticosteroids, methotrexate, and rituximab, resulted in clinical and radiological improvement in all the patients within 3-6 months. The addition of co-trimoxazole reduced the incidence of non-severe GPA relapses. Tailored treatment plans addressing both infectious and autoimmune aspects are essential for optimal care in GPA complicated by concurrent infections. This study highlights the need for a multidisciplinary approachinvolving pulmonologist, rheumatologist, microbiologist, and pathologistin the diagnosis and treatment of GPA, emphasizing the importance of individualized treatment plans tailored to the specific clinical scenario.

Novel cathepsin C inhibitor, BI 1291583, intended for treatment of bronchiectasis: Phase I characterization in healthy volunteers.

Novel treatments are needed to reduce inflammation, improve symptoms, address exacerbations, and slow disease progression in bronchiectasis. Cathepsin C (CatC) inhibition promises to achieve this through reduction of neutrophil-derived serine protease (including neutrophil elastase [NE] and proteinase 3 [PR3]) activation. Here, we present the phase I characterization of the novel CatC inhibitor, BI 1291583. Five phase I trials of BI 1291583 in healthy subjects are presented: a single-rising-dose study (NCT03414008) and two multiple-rising-dose studies (NCT03868540 and NCT04866160) assessing the safety, tolerability, pharmacodynamics, and pharmacokinetics of BI 1291583; a food effect study (NCT03837964); and a drug-drug interaction study (NCT03890887) of BI 1291583 and itraconazole. BI 1291583 was safe and well tolerated across the doses tested in these trials. Most adverse events (AEs) were mild or moderate in intensity, with no serious AEs, AEs of special interest or deaths reported in any trial. Drug-related skin exfoliation was not reported more frequently in subjects treated with BI 1291583 compared with placebo. BI 1291583 was readily absorbed, and pharmacokinetics were supra-proportional over the dose ranges assessed. Additionally, BI 1291583 inhibited CatC in a dose-dependent manner, inhibited downstream NE activity, and decreased PR3 levels. No food effect was observed. Co-administration of multiple doses of itraconazole increased BI 1291583 exposure approximately twofold. Due to these promising phase I results, a multinational phase II program of BI 1291583 in adults with bronchiectasis is ongoing (Airleaf™ [NCT05238675], Clairafly™ [NCT05865886], and Clairleaf™ [NCT05846230]).

Spectroscopic properties of Pr3+-doped Titania-Silicate glass ceramic for photonic applications

Silicate-Titania (SiTi) glass-ceramics doped with Pr3+ (0.6, 1.6, 2.4 and 3.6 mol%) ions were prepared by sol-gel technique. The materials were characterized by powder XRD, FTIR, TEM, EDX, Optical absorption and Photoluminescence spectroscopy. The identification of non-bridging oxygen (NBO) formation and the removal of OH groups are validated through analysis of the FTIR spectra. Additionally, measurements using XRD and TEM showed that the samples contain nano-sized crystallites. The three phenomenological Judd–Ofelt (J–O) intensity parameters Ω2, Ω4, and Ω6 were obtained and used to analyze different radiative characteristics for the fluorescence levels of Pr3+ in the glass ceramic, including radiative lifetime, branching ratio, radiative transition probability and stimulated emission cross-section. Several emissions were observed in the visible region, among which the 1D2→3H4 in the orange-red region is the most intense. All of these reported branching ratios, stimulated emission cross-sections, and visible emission spectra point to the possibility of employing them as red region lasers. The CIE chromaticity coordinates from all of the emission spectra were also assessed to determine if these materials are suitable for orange-red phosphors. According to CIE chromaticity investigations, 1.6 mol% of Pr3+ ion concentration is ideal for SiTiPr glass-ceramic for use as red phosphors and possibly red lasers.

Growth and spectroscopic properties of Ca3(Ta,Ga)5O12:Pr3+ single crystal as a promising new laser material in the visible domain

Structurally disordered Pr3+-doped Ca3(Ta,Ga)5O12 - Pr:CTGG single crystal was grown by the Czochralski technique for the first time and its spectroscopic properties were investigated. Modified Judd-Ofelt analysis was applied to determine spectroscopic and laser emission characteristics. Based on low-temperature absorption and emission spectra, the partial energy levels of Pr3+ ions have been obtained and a multicenter structure of the optical spectra was highlighted. The electron-phonon interactions were also observed in the emission spectra corresponding to the 3P0 → 3H4 transition under different excitation wavelengths. The fluorescence decays of the 3P0 and 1D2 levels were measured. The emission cross-sections corresponding to the 3P0 → 3H4 (486.5 nm) and 3P0 → 3F2 (652.7 nm) transitions were found to be σem = 19 × 10−20 cm2 and σem = 15 × 10−20 cm2, respectively. The values for other parameters that may predict the possibility of achieving efficient laser emission, especially at 486.5 nm, such as quantum efficiency (ⴄ = 50 %), gain bandwidth (σem× Δλeff, = 32.2 × 10−26 cm3), and optical gain (σem× τmeas = 12.86 × 10−25 cm2 s) were determined. The obtained results indicate that the Pr:CTGG crystal has a high potential for obtaining efficient laser emission in the blue domain.

Simultaneously significant transparency enhancement and efficient temperature feedback achieved in AlON ceramic through luminescent rare earth doping

Activator-doped aluminum oxynitride (γ-AlON) could provide an extremely versatile transparent ceramic with photothermal feedback, opening the door to many new applications and devices for use in extreme conditions. However, existing AlON transparent ceramics have failed to achieve temperature-responsive luminescence. To address this, a simple-to-implement luminescent rare-earth doping strategy for fabricating AlON transparent ceramic with efficient temperature feedback is proposed and demonstrated. Luminescent Pr2O3 serves as the illustrative example. Benefiting from the liquid phase formed by Pr2O3 and the thermal coupling between the 3P1 and 3P0 levels of Pr3+, AlON ceramics doped with Pr2O3 exhibit significantly elevated transparency and temperature-responsive luminescence. More importantly, the AlON:Pr ceramic can serve as photothermal feedback windows, which presents attractive performance. This paradigm fills an important gap in the AlON transparent ceramics for temperature feedback windows, and will inspire the controllable design of luminescent rare-earth doped AlON ceramics for use in harsh conditions.

Towards High-Quality Broad-Range Luminescence Thermometry - the Case of Pr3+-Activated Garnets

Accurate and sensitive remote temperature measurement over a wide range of temperatures, presumably 1000 degrees, is required in many existing and emerging applications. Novel and emerging technologies pose new requirements on the quality of temperature measuring, the resistance to disturbance by external electric and/or magnetic fields, spatial resolution, and the operating range of thermometers. Luminescence thermometry has the potential to become the technology of choice when classic methods become non-practical and/or do not offer the expected quality.Designing a luminescence thermometer capable of measuring temperature reliably over, for example, 1000 degrees range is challenging, as managing luminescence processes in such a range is extremely difficult. Yet, wide-range luminescence thermometers are of interest in such fields as aviation, space, nuclear plant, and others. Fast, accurate, and credible measurements of quickly changing temperatures are critical in these areas.In this presentation, we shall report on the thermometric competencies of a series of garnet phosphors, typically activated with Pr3+. We shall focus on the possibility of managing the physics related to energy flow between the excited levels of Pr3+ and thermal quenching of its three emissions resulting from the 5d®4f, 3PJ®3HJ and 1D2®3HJ transitions. Not only shall we demonstrate that the sensitivity of such sensors may be deliberately tuned to reach its maximum at temperatures where it is most needed, but we will also show that garnets nowadays may offer temperature measuring over a range of 800 degrees at least. This research was supported by the Polish National Science Center (NCN) under the grant #UMO2018/29/B/ST5/00420. Figure 1

P21 Lupus or else?

P21 Lupus or else?

Deep insight on two luminous mechanism and optical properties of Pr doped MgGeO3 red/NIR luminescent materials

In this work, MgGeO3:Pr3+ system is prepared by high-temperature solid phase method under the condition of different temperature and Pr content. MgGeO3:Pr3+ could emit 622 nm (red), 716 nm (red), 903 nm (NIR) and 1081 nm (NIR) lights under the external excitation of 251 nm and 425–500 nm. Due to the different excitation wavelengths, MgGeO3:Pr3+ has completely different electronic transition paths, resulting in a much larger emission intensity under 251 nm excitation than that excited by 425∼500 nm. When the incident light wavelength is 251 nm, the excitation process is VB→1D2 level of Pr3+, and the emission is due to transition of 1D2→3H4, 1D2→3H5, 1D2→3H6(3F2) and 1D2→3F3,4. When the wavelength of incident light is 425∼500 nm, the excitation process is 3H4→CB, the emission is CB→1D2, and then 1D2→3H4, 1D2→3H5, 1D2→3H6(3F2) and 1D2→3F3,4. At the same time, the emission spectrum and X-ray diffraction measurements show that the most fundamental factor determining the emission intensity of the sample is the concentration of the luminescent center (Pr3+ that can emit light) in the MgGeO3 grain. Increasing the sintering temperature and Pr element content in raw materials can increase the of Pr3+ concentration in the grain (increase the concentration of the luminescent center). However, if the concentration of Pr3+ in the grain is too high, Pr3+ would lose the function of the luminescence center, resulting in a decrease in the concentration of the luminescence center, thereby reducing the luminescence intensity.

Extending the Palette of Luminescent Primary Thermometers: Yb3+/Pr3+ Co-Doped Fluoride Phosphate Glasses.

The unique tunable properties of glasses make them versatile materials for developing numerous state-of-the-art optical technologies. To design new optical glasses with tailored properties, an extensive understanding of the intricate correlation between their chemical composition and physical properties is mandatory. By harnessing this knowledge, the full potential of vitreous matrices can be unlocked, driving advancements in the field of optical sensors. We herein demonstrate the feasibility of using fluoride phosphate glasses co-doped with trivalent praseodymium (Pr3+) and ytterbium (Yb3+) ions for temperature sensing over a broad range of temperatures. These glasses possess high chemical and thermal stability, working as luminescent primary thermometers that rely on the thermally coupled levels of Pr3+ that eliminate the need for recurring calibration procedures. The prepared glasses exhibit a relative thermal sensitivity and uncertainty at a temperature of 1.0% K-1 and 0.5 K, respectively, making them highly competitive with the existing luminescent thermometers. Our findings highlight that Pr3+-containing materials are promising for developing cost-effective and accurate temperature probes, taking advantage of the unique versatility of these vitreous matrices to design the next generation of photonic technologies.

Optical properties of 40ZnO-40P2O5-x(10Li2O-10Nb2O5-0.2Pr3+) glass

Zinc phosphate glasses with composition of 40ZnO-40P2O5-x(10Li2O-10Nb2O5-0.2Pr3+) (0 ≤ x ≤ 2.0) were fabricated using melt-quenching technique. The structural and optical properties of the prepared glasses were analyzed using the XRD, UV–vis-NIR absorption, FT-IR spectroscopy and luminescence studies. With increasing x value of the 10Li2O-10Nb2O5-0.2Pr3+ doping content, the glass exhibits deep blue (before x = 1.0) and then yellow (after x = 1.0) in color. The studied glass exhibits strong red emission at 600 nm as well as NIR emission at 1034 nm, ascribed to the Pr3+ transitions of 1D2 → 3H4 and 1D2 → 3F3,4, respectively. The intensity of Pr3+ emission rises with increasing of 10Li2O-10Nb2O5-0.2Pr3+ content in the glass. Upon excitation into the 3P2 level of Pr3+, the luminescence decay curves for Pr3+ red emission show non-monoexponential nature with the average lifetime decreasing from 151.5 to 102.6 μs with x increasing from 0.4 to 2.0. With post heat treatment at 575 °C for different times, the glass 40ZnO-40P2O5-x(10Li2O-10Nb2O5-0.2Pr3+) (x = 1.0) exhibits change in color from 0 to 12 h, and luminescence intensity enhancement from 0 to 1 h.

Photoluminescence study of rare earth ions doped Sr2CeO4 phosphor prepared via conventional solid-state reaction method

The lanthanide ions either in their divalent or trivalent charge state form a very important class of luminescence activators in phosphors and single crystals. Doping these lanthanide ions in different host lattices are widely utilized in many areas for example the 5d-4f emission of Ce3+ used in scintillators for γ-ray detection, cathode ray tubes and electroluminescence phosphors. The photon cascade emission from 4f2 levels of Pr3+ used for developing high quantum efficiency phosphors excited by means of a Xe discharge in the vacuum-UV. The narrow line 4f3 transition in Nd3+ is used in laser crystals. The Sm3+ emission used as an electron trap and in information storage properties like optical memory applications, X-ray imaging phosphor applications. The famous 5D0-7Fj 4f6 redline emission of Eu3+ and the blue to red 5d-4f emission of Eu2+ are used in display and lighting phosphors. The 4f8 line emission of Tb3+ is used in tricolor tube lighting. The Dy3+ emission plays an important role in the persistent luminescence phosphors. Er3+, Tm3+ used to investigate for possible photon cascade emission phosphor applications. This is brief and still incomplete summary illustrates the diversity of applications involving the luminescence of lanthanide ions.

Deciphering competing radiative relaxation pathways observed in Pr3+-Activated yttrium-based compounds: UV emission versus visible emission

Pr3+-activated yttrium-based compounds have garnered significant research interest as the electronic transition of Pr3+ dopant incorporated in host lattices are quite versatile, giving rise to the production of either UV or visible electromagnetic radiation. The tunable 5d orbital energy level of Pr3+ with an electronic configuration [Xe]4f15d1 depending on the external crystal fields, coordinating anion ligands (mainly determined by covalency of anion ligands), and symmetry of crystal structures can indeed control the radiative decay processes whether to generate UV or self-trapped exciton-mediated visible emission. We have investigated three different Pr3+-activated crystals of YPO4, YBO3, and Y2SiO5 using two different excitation processes including direct host lattice excitation (cathodoluminescence: CL) and f-d excitation of Pr3+ dopants (photoluminescence: PL). Such radiative decay mechanism observed in Pr3+-doped yttrium-based compounds has been deciphered that photoexcitation of Pr3+ ions results in 4f15d1→4f2 electronic transition with UV emission (PL) whereas above-bandgap excitation of host lattices brings about the efficient production of visible emission mediated through self-trapped excitons (CL). When changing the anion sublattices, the emission peak corresponding to 4f15d1→4f2 transition shifted to longer wavelength as a result of modulated covalency and crystal field strength. As the host lattices changes as a function of anion sublattices, the bandgap reduced from 8.6 eV (for YPO4) to 7.6 eV (for YBO3) and to 6.1 eV (for Y2SiO5), directly influencing rate of trapping of exciton and their formation of self-trapped exciton, which further give rise to production of the self-trapped exciton mediated visible emission. The fundamental understanding of the multiple, radiative relaxation pathways provides a designing principle for achieving more efficient UV emitting phosphors (at the same time by suppressing visible emission or vice versa) for germicidal and medical applications.

Wavelength extension and power improvement of red Pr3+:YLF lasers.

High-power red lasers (mainly at 639 and 670 nm) based on Pr3+:YLF crystals have been presented in many works. However, the spectral resources of Pr3+:YLF in the red region have not been fully developed to obtain lasers due to their relatively low emission cross sections and the irrepressible strong emission at ∼639 nm. In this work, we propose a scheme to further develop the spectral resources of Pr3+:YLF in the red region and improve the red laser powers based on this crystal. The laser wavelengths are obtained from 634.5 to 674.7 nm (continuous tunings are achieved at some wavebands). To the best of our knowledge, the output powers obtained at 638.7, 644.6, 670.1, and 674.7 nm (2.88 W, 1.87 W, 3.55 W, and 1.73 W, respectively) are the highest to date. Furthermore, lasing originating from the 3P2 energy level of Pr3+:YLF (∼653 nm) is realized for the first time.

Investigation of structural and optical properties of Pr3+ doped and Pr3+/Dy3+ co-doped multicomponent bismuth phosphate glasses for visible light applications

Pr3+ doped 59.5P2O5+15Bi2O3+10BaF2+10xF+05TeO2+0.5Pr6O11 glasses and Pr3+/Dy3+ co-doped 59P2O5+15Bi2O3+ 10BaF2+ 10xF + 05TeO2+0.5Dy2O3+0.5Pr6O11 glasses (where xF = LiF, NaF, MgF2, KF, CaF2 and SrF2) were synthesized using melt quenching route. Structural properties were researched for different modifier fluorides. With the dopant constant concentration the absorption and luminescence intensity variance influenced by this multicomponent incorporation has been observed. The energy transfer between resonance levels of Pr3+ and Dy3+ through fluorescence studies also examined for Mg and Sr glasses. Long-range nature of prepared glasses, morphological studies with elemental probe, various functional groups pertaining to glass matrices and the non-bridging oxygen bonds with PO4 tetrahedron or depolymarization of oxygen bonds in the presence of the modifier cations with phosphates were thoroughly understood with PXRD, FTIR and 31P NMR characterizations. Judd-Ofelt (J-O) theory has been adopted to estimate important optical parameters. From the fluorescence studies laser characteristic parameters such as optical band gains (σe × τR) and gain bandwidths (σe × Δλeff) were calculated and compared in the present fabricated glasses influenced by various modifiers.

Crystal growth, polarization spectral analysis derived from the broadband emission from the 1D2 level of Pr:GdScO3 crystal

Pr3+-doped GdScO3 single crystal was successfully grown by the Czochralski (Cz) method. Polarized absorption spectra, polarized fluorescence spectra, and fluorescence decay curves were measured at room temperature. The polarized spectroscopic property of Pr:GdScO3 crystal for new-wavelength transition in the near infrared (NIR) region was discussed for the first time. The absorption cross-sections at 600 nm were calculated to be 0.39×10−20 cm2 (E∥a), 0.32×10−20 cm2 (E∥b) and 0.4×10−20 cm2 (E∥c). The emission cross sections at 1053 nm of 1D2 energy level were calculated to be 0.86×10−20 cm2 (E∥a), 0.79×10−20 cm2 (E∥b) and 0.78×10−20 cm2 (E∥c), with FWHM of 57.54 nm, 57.96 nm and 58.96 nm, respectively. The fluorescence lifetime and radiative lifetime of the 1D2 energy levels of Pr3+ ions were 45.46 µs and 393.94 µs, respectively. Those results show that the Pr:GdScO3 crystal should be the potential near infrared laser gain medium originated from the 1D2 transition.

Effect of Pr3+ concentration on the luminescent properties of Ca2LuScGa2Ge2O12 compound with garnet structure

The purpose of this work is to study the luminescence characteristics of Pr3+ ions and develop new luminescent materials. Based on the chemical properties of germanate and the special structural characteristics of garnet. A series of Ca2LuScGa2Ge2O12 compounds with garnet structure doped with Pr3+ ions were prepared by high-temperature solid phase method. The structure, composition, and morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The diffuse reflectance and photoluminescence (PL) properties of the material were studied by UV–visible spectrophotometer. The effect of Pr3+ concentration on its luminescence properties and the concentration quenching mechanism of Pr3+ ions were studied in detail. Two interesting luminescent phenomena were observed. One is that the quenching concentration of the 1D2 energy level of Pr3+ ions is much lower than that of the 3P0 energy level. Second, the quenching concentration of 3P0 level is also different when the excitation wavelength is different. Dexter's model is used to prove that the quenching of the luminous intensity of the 3P0 and 1D2 energy levels of Pr3+ in CLSGG is caused by the dipole-dipole interaction. And later the multi-phonon interaction and cross-relaxation process explain the Pr3+ ion concentration quenching caused by non-radiative energy transition. At the same time, it is also found that the color gamut of the compound can be adjusted by changing the doping concentration of Pr3+.

Optical properties of Praseodymium (Pr3+) doped bismuth boro-tellurite glasses containing CdSe nanoparticles

Adding TeO2 and growing nanoparticles of CdSe can significantly affect the optical properties of Pr3+ ions doped in bismuth borate glasses. We used a modified Judd-Ofelt analysis to obtain the intensity parameters from the optical absorption spectra. Adding TeO2 leads to an increase in the covalency of the Pr-O bond. However, the presence of CdSe nanoparticles makes Pr-O bond less covalent. Optical band gap shows a considerable decrease when nanoparticles are present. Phonon side band analysis suggests that energy levels of Pr3+ responsible for the intense red emission are populated through a cross-relaxation mechanism instead of multiphonon decay process. The blue transition of Pr3+ shows significant enhancement for the stimulated emission cross-section when CdSe nanoparticles are present. Chromaticity analysis identifies the overall light emissions from different glass samples with various standard sources. Our glass samples also possess high spectroscopic quality factors compared to similar systems doped with Pr3+ ions.

Multi-responsive deep-ultraviolet emission in praseodymium-doped phosphors for microbial sterilization.

Perusing multimode luminescent materials capable of being activated by diverse excitation sources and realizing multi-responsive emission in a single system remains a challenge. Herein, we utilize a heterovalent substituting strategy to realize multimode deep-ultraviolet (UV) emission in the defect-rich host Li2CaGeO4 (LCGO). Specifically, the Pr3+ substitution in LCGO is beneficial to activating defect site reconstruction including the generation of cation defects and the decrease of oxygen vacancies. Regulation of different traps in LCGO:Pr3+ presents persistent luminescence and photo-stimulated luminescence in a synergetic fashion. Moreover, the up-conversion luminescence appears with the aid of the 4f discrete energy levels of Pr3+ ions, wherein incident visible light is partially converted into germicidal deep-UV radiation. The multi-responsive character enables LCGO:Pr3+ to response to convenient light sources including X-ray tube, standard UV lamps, blue and near-infrared lasers. Thus, a dual-mode optical conversion strategy for inactivating bacteria is fabricated, and this multi-responsive deep-UV emitter offers new insights into developing UV light sources for sterilization applications. Heterovalent substituting in trap-mediated host lattice also provides a methodological basis for the construction of multi-mode luminescent materials.

Optical properties of a new (1−x)Bi1/2Na1/2TiO3 + xPr1/2Na1/2TiO3 solid solution system

The solid solutions of Bi1/2Na1/2TiO3 and Pr1/2Na1/2TiO3 materials were successfully synthesized by a simple chemical method. X-ray diffraction measurements of the Pr1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 materials indicated that Pr1/2Na1/2TiO3 was well dissolved into the host Bi1/2Na1/2TiO3 materials, resulting in the random incorporation of Pr cations in the host materials. The optical bandgap of the Pr1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 materials slightly reduced as increasing Pr1/2Na1/2TiO3 concentrations, from 3.04 eV for the pure Bi1/2Na1/2TiO3 material to 2.95 eV for the sample with 9 mol.% of Pr1/2Na1/2TiO3. We observed strong photoluminescence emission at 610 nm in the Pr1/2Na1/2TiO3-modified Bi1/2Na1/2TiO3 system, which originated from electron transitions from 3P0 to 3H6 levels of Pr3+ cations. We expected that our work would provide a simple method to combine photoluminescence properties in lead-free ferroelectric materials for smart electronic device applications.