[Short-term Effect of Venetoclax Combined with Azacitidine and "7+3" Regimen in the Treatment of Newly Diagnosed Elder Patients with Acute Myeloid Leukemia].

OBJECTIVE: To compare the short-term effect and adverse reaction of venetoclax (VEN) combined with azacitidine (AZA) versus "7+3" regimen in newly diagnosed elder patients with acute myeloid leukemia (AML). METHODS: From January 2021 to January 2022, the clinical data of seventy-nine newly diagnosed elder patients with AML at the Second Hospital of Shanxi Medical University and the Shanxi Bethune Hospital were retrospectively analyzed, including VEN+AZA group (41 cases) and "7+3" group (38 cases). The propensity score matching(PSM) method was used to balance confounding factors， then response， overall survival(OS), progressionfree survival(PFS) and adverse reactions between the two groups were compared. RESULTS: The ORR of VEN+AZA group and "7+3" group was 68% and 84%, respectively, and the CRc was 64% and 72%, respectively, the differents were not statistically significant (P >0.05). In the VEN+AZA group, there were 5 non-remission (NR) patients, 4 with chromosome 7 abnormality (7q-/-7), and 1 with ETV6 gene mutation. Median followed-up time between the two groups was 8 months and 12 months, respectively, and the 6-months OS was 84% vs 92% (P =0.389), while 6-months PFS was 84% vs 92% (P =0.258). The main hematological adverse reactions in two groups were stage Ⅲ-Ⅳ myelosuppression, and the incidence rate was not statistically different(P >0.05). The median time of neutrophil recovery in two groups was 27(11-70) d, 25(14-61) d （P =0.161）, and platelet recovery was 27(11-75) d, 25(16-50) d （P =0.270）, respectively. The infection rate of VEN+AZA group was lower than that of "7+3" group (56% vs 88%, P =0.012）. The rate of lung infections of two groups was 36% and 64%, respectively, the difference was statistically significant (P =0.048). CONCLUSION: The short-term effect of VEN+AZA group and "7+3" regimens in eldrly AML patients are similar， but the VEN+AZA regimen had a lower incidence of infection. The presence of chromosome 7 abnormality（7q-/-7） may be a poor prognostic factor for elderly AML patients treated with VEN+AZA.

[Early Efficacy Observation of Pomalidomide-based Regimen in the Treatment of High-risk Multiple Myeloma].

OBJECTIVE: To investigate the efficacy and safety of pomalidomide based regimen in the treatment of high-risk multiple myeloma (MM). METHODS: Clinical data of 27 high-risk MM patients treated in Shanxi Bethune Hospital from January 2021 to December 2022 were retrospectively analyzed. All patients were treated with pomadomide based regimen for at least 2 consecutive cycles, and the early therapeutic effect and safety were observed. RESULTS: Overall remission rate (ORR) was 63.0%(17/27 cases) and deep remission rate was 22.2%(6/27 cases) after 2 cycles of treatment; ORR was 90.5%(19/21 cases) and deep remission rate was 66.7%(14/21 cases) after 4 cycles of treatment. Both ORR and deep remission rate were significantly higher after 4 cycles of treatment than 2 cycles (P=0.044, P=0.003). Beyond that, in the newly diagnosed and relapsed refractory MM groups, ORR after 2 cycles of treatment were 75%(9/12 cases) and 60%(9/15 cases), and deep remission rates were 25%(3/12 cases) and 20%(3/15 cases), respectively; ORR after 4 cycles of treatment were 100%(9/9 cases) and 83.3%(10/12 cases), and deep remission rates were 77.8%(7/9 cases) and 58.3%(7/12 cases), respectively, while there was no significant difference in remission rates between the two groups (P>0.05). In the group of creatinine ≥177 µmol/L, the serum creatinine level was significantly decreased after 2 cycles of treatment compared with that pre-treatment (P=0.001). The 1q21 amplified subgroup accounted for the largest proportion (21/27 cases), ORR was 66.7%(14/21 cases) and deep remission rate was 23.8%(5/21 cases) after 2 cycles of treatment, ORR was 88.9%(16/18 cases) and deep remission rate was 66.7%(12/18 cases) after 4 cycles of treatment. In all the symptoms, the most common adverse reactions were pulmonary infection in 9 cases and hematological adverse reactions of grade 1-2 in 8 cases. CONCLUSION: The pomalidomide-based treatment regimen has good early curative effect on the newly diagnosed and relapsed refractory high-risk MM, and also benefits to the high-risk cytogenetic MM, or MM with renal impairment. Therefore, this treatment regimen showed a good safety, and the long-term curative effect needs to be further assessed by more clinical data.

[Advances of Targeted Therapy for Acute Myeloid Leukemia--Review].

Acute myeloid leukemia (AML) has highly heterogeneous clinical manifestations and poor prognosis, and traditional chemotherapy is the main treatment. In recent years, with the in-depth development of next-generation sequencing technology, the treatment of AML is gradually exploring the precise targeted therapy in the direction of molecular biology and immunophenotype. The advent of various small-molecule inhibitors and immune-targeted drugs has brought hope to patients who cannot tolerate intensive chemotherapy or with relapsed/refractory AML. Compared with traditional chemotherapy, targeted therapy has the advantages of significant curative effect and fewer adverse effects. This article reviews the latest research progress of targeted drug therapy for AML.

[Impact of CSF3R Mutation on Treatment Response and Survival of Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the expression of CSF3R mutation in acute myeloid leukemia (AML) and analyze its clinical characteristics and prognosis. METHODS: A retrospective study was conducted in 212 patients with AML who were newly diagnosed in the Second Hospital of Shanxi Medical University from January 1th 2018 to June 30th 2021, including 22 patients with CSF3R mutations as mutation group and 190 patients with CSF3R wild type ï¼»66 cases of them were screened by propensity score matching (PSM), as control groupï¼½. The early efficacy and survival between the two groups were compared. RESULTS: The median age of patients in the mutation group was 50(17-73) years old, and the ratio of male to female was 1.2:1 The main types were AML with maturation (11 cases) and acute myelomonocytic leukemia (9 cases). Prognostic stratification was carried out according to the risk stratification system of the European leukemia network in 2017, with 16 cases (72.73%) in the middle and high-risk group. At the initial diagnosis, the median count of white blood cell (WBC) was 44.75(1.30-368.71)×109/L, among which 15 cases (68.18%) were >10×109/L, and the median count of platelet (PLT) was 24(4-55)×109/L. CSF3R T618I (68.18%) was a common mutation site, which had concomitant gene mutations, in which CEBPA mutation was the most common (10 cases, 45.45%), but only existed in CSF3R T618I mutation. The CR/CRi rate was 68.18% and 71.21% in the mutant group and the control group (P >0.05), the median over all survival time was 15 months and 9 months (P >0.05), and the median disease-free survival time was 8 months and 4 months (P >0.05), respectively. CONCLUSION: Most AML patients with CSF3R mutation are middle-aged patients, the main types are AML with maturation and acute myelomonocytic leukemia, and most of them have middle and high-risk prognosis. CSF3R mutation may not be an independent prognostic marker for newly diagnosed AML patients.

[Hematological Neoplasms Secondary to Malignant Solid Tumors with Radiotherapy and Chemotherapy: a Clinical and Prognostic Analysis].

OBJECTIVE: To explore the clinical characteristics, treatment and prognosis of therapy-related hematological neoplasms patients secondary to malignant solid tumors. METHODS: The clinical features, treatment and prognosis of 36 hematological neoplasms patients secondary to malignant solid tumors with radiotherapy and chemotherapy in the Second Hospital of Shanxi Medical University were retrospectively analyzed. RESULTS: The 36 patients with therapy-related hematological neoplasms had a median age of 60 (47-81) years, 14 were male and 22 were female. Among them, 22 cases were acute myeloid leukemia, 5 cases were acute lymphoblastic leukemia, 4 cases were multiple myeloma, 3 cases were myelodysplastic syndrome, and 2 cases were non-hodgkin's lymphoma. The median latency of malignant tumor to hematological neoplasm was 42.5 (12-120) months. The median survival time of therapy-related hematological neoplasms was 10.5 (1-83) months, and the 3-year overall survival (OS) rate was 24.3%. The therapy-related acute myeloid leukemia patients had a very poor prognosis, with a median survival of 7 (1-83) months and a 3-year OS rate of 21.4%. CONCLUSION: The prognosis of therapy-related hematological neoplasms secondary to malignant solid tumors with radiotherapy and chemotherapy is poor, and individualized treatment should be implemented according to the clinical situation of patients.

Fluorescence Lifetime-Based Luminescent Thermometry Material with Lifetime Varying over a Factor of 50.

Recently, the growing demand for temperature detection is pushing forward the flourishing development of noncontact optical thermometry. Herein, a new red phosphor Sr2InTa1-xO6:xMn4+ (SIT:xMn4+) was first constructed and systematically investigated. Based on the fairly rapid decline of the lifetime from 0.403 to 0.008 ms by increasing the temperature from 25 to 450 K, a noncontact optical thermometer can be made from phosphor SIT:0.003Mn4+ with Sr = 1.396% K-1 at 375 K and Sa = 0.0012 K-1 at 300 K. Because the luminescence is based on the outermost 3d orbits of Mn4+, the lifetime of SIT:xMn4+ is quite sensitive to the temperature, leading to a rapid decline of the lifetime with the increase in temperature. Moreover, multiple rounds of variable-temperature studies were performed to demonstrate the stability and reversibility of SIT:0.003Mn4+. This work suggests that Mn4+-phosphors are promising candidates for application as optical thermometric material.

Utilizing the energy transfer mechanism to realize color tunable luminescence.

Bi3+/Eu3+ co-doped phosphors can realize multi-color luminescence by adjusting the concentration ratio, which makes it possible to manually control the emission color. On this basis, a series of Bi3+/Eu3+ co-doped phosphors SrLaGa3O7:xBi3+,yEu3+ were prepared. The existence of energy transfer from Bi3+ to Eu3+ was verified by spectral analysis. The emission spectra of SrLaGa3O7:xBi3+ show a wide-band peaking at 472 nm. For SrLaGa3O7:xBi3+,yEu3+, the Bi3+ → Eu3+ energy transfer occurs and a series of sharp emitting peaks of Eu3+ can be observed simultaneously. The relative luminescence intensity of Bi3+ and Eu3+ can be modulated by changing the relative concentrations of Bi3+ and Eu3+. Using this mechanism, the color tunable luminescence of SrLaGa3O7:xBi3+,yEu3+ from cyan, through white to orange, and finally to red is realized. By using a 320 nm UV chip and SLG:0.06Bi3+,0.07Eu3+ white phosphor, a white light-emitting diode (WLED) lamp was fabricated with chromaticity coordinates of (0.3199, 0.3083) and a color rendering index Ra of 82. This indicates that the prepared sample is a very promising candidate in the LED field.

(3+1)-Dimensional Modulated Structure and Tb3+-Doped Luminescence for Vanadate Na3La(VO4)2.

A modulated structure with symmetrical characteristic higher than three-dimensional is a fascinating crystallographic type, and it is randomly encountered by researchers. Herein, we prepared 0.1 mm level single crystals of Na3La(VO4)2 and determined its structure to be a (3 + 1)-dimensional modulated structure using the X-ray diffraction analysis method for single crystals. Its super space group was determined to be Pca21(0ß0)000. On the other hand, we introduced Tb3+ into the Na3La(VO4)2 host lattice to fabricate phosphors Na3La1-x(VO4)2:xTb3+ and studied their photoluminescence properties. Interestingly, for the strong absorption of the Na3La(VO4)2 host lattice in the range of 200-400 nm, the traditional 330-385 nm light is unable to efficiently excite Tb3+ ions in the Na3La(VO4)2 host to generate luminescence of Tb3+. Instead, Na3La1-x(VO4)2:xTb3+ is suitable to be excited by 487 nm to generate emitting light at 543, 584, and 622 nm, due to Tb3+ characteristic 4f → 4f transitions of 5D4 → 7FJ (J = 5, 4, 3). Hence, the Tb3+-doped Na3La(VO4)2 phosphors have potential applications for white-light-emitting diodes.

Inter-Alpha-Trypsin Inhibitor Heavy Chain 4 Plays an Important Role in the Development and Reproduction of Nilaparvata lugens.

The brown planthopper, Nilaparvata lugens, is a difficult-to-control insect pest affecting rice yields in Asia. As a structural component of the inter-alpha-trypsin inhibitor (ITI), the inter-alpha-trypsin inhibitor heavy chain (ITIH) has been reported to be involved in various inflammatory or malignant disorders, ovarian development, and ovulation. To reveal the function of ITIH4 in N. lugens, the gene encoding N. lugens ITIH4 (NlITIH4) was cloned and characterized. NlITIH4 contains a signal peptide, a vault protein inter-alpha-trypsin domain, and a von Willebrand factor type A domain. qPCR analysis showed that NlITIH4 was expressed at all developmental stages and in all tissues (fat body, ovary, and gut), with the highest expression in the fat body. Double stranded NlITIH4 (dsNlITIH4) injection clearly led to an RNAi-mediated inhibition of the expression of NlITIH4 and resulted in reduced survival, delayed ovarian development, and reduced egg production and egg hatching. These results indicate that NlITIH4 plays an important role in the development and reproduction of N. lugens.

[Clinical Features of Infection in Newly Diagnosed Patients with Myelodysplastic Syndrome and Its Correlation with Curative Effect].

OBJECTIVE: To explore the characteristics of infection in patients with myelodysplastic syndromes (MDS), risk factors of serious infection, and their correlation with curative effect. METHODS: The clinical data of 92 newly diagnosed MDS patients with nosocomial infection from January 2016 to June 2020 in our hospital were retrospectively analyzed. RESULTS: A total of 306 courses of treatment were completed in 92 newly diagnosed MDS patients. The infection rate was the highest in the first course of treatment (84.8%, 78/92), and then decreased gradually. The top three infection sites were lung, upper respiratory tract, and gastrointestinal tract. A total of 90 strains of pathogenic bacteria were detected, of which 33.4% (30/90) were gram-negative bacilli, 23.3% (21/90) were gram-positive cocci, 23.3% (21/90) were fungi, and 20.0% (18/90) were viruses. The serious infection rate among 92 patients with MDS was 22.8% (21/92). Multivariate analysis showed that neutrophil deficiency>7 days (OR=10.875, 95%CI: 2.747-43.051, P=0.001) was an independent risk factor for serious infection in MDS patients. Compared with non-severe infection group, the total effective rate of severe infection group was lower (90.9% vs 63.6%, χ2=4.393, P<0.05). CONCLUSION: The infection rate of MDS patients is high in the first course of treatment, and the most common infection site is the lung. Gram-negative bacteria is the most common pathogen. MDS patients with neutrophil deficiency>7 days have a high risk of serious infection and poor efficacy.

A new type of phosphate-based phosphor Na3CsMg7(PO4)6:Eu2+/Mn2+ with high quantum efficiency and high thermostability.

The Eu2+ ion, with the 4f75d1 electronic configuration, is one of the most important activated ions due to its symmetry-allowed 4f → 5d electron transition. Herein, we successfully prepared a new type of blue phosphor, Na3CsMg7(PO4)6:xEu2+ (NCMP:xEu2+), in which Eu2+ occupies the Na+ sites of the host lattice. Under 395 nm light excitation, a broad emission band from 410 to 550 nm can be seen, peaking at 458 nm, due to the 5d → 4f transition of Eu2+. Moreover, Eu2+ can be used as a sensitizer ion in an NCMP host. For co-doping phosphor NCMP:0.18Eu2+/0.4Mn2+, both Eu2+ and Mn2+ emission bands can be seen using 395 nm as the excitation wavelength for the occurrence of Eu2+ → Mn2+ charge transfer. The optimized concentration of Eu2+ for NCMP:xEu2+ is x = 0.18, with high internal (IQE) and external quantum efficiencies (EQE) of 66.4% and 22.8%. The luminescence of NCMP:0.18Eu2+ has high thermostability with 77.3% the intensity at 450 K compared to that at 300 K. Finally, a white illuminating lamp was produced using a 395 nm UV chip, blue phosphor NCMP:xEu2+, green phosphor (Sr,Ba)2SiO4:Eu2+ and red phosphor CaAlSiN3:Eu2+ with CIE coordinates of (0.378, 0.369), color temperature (CCT) of 3971 K, and color rendering index (Ra) of 79.8.

Compound heterozygous p.L483P and p.S310G mutations in GBA1 cause type 1 adult Gaucher disease: A case report.

BACKGROUND: Gaucher disease (GD) is caused by a GBA1 gene mutation that leads to decreased acid ß-glucosidase activity [glucocerebrosidase (GCase)]. This study aimed to identify and characterise compound heterozygous mutations in GBA1 in a patient with type 1 GD. CASE SUMMARY: Here, we report a rare adult-onset type 1 GD in a 46-year-old female patient with clinical manifestations of giant spleen, thrombocytopenia, and bone pain, diagnosed by enzymatic and genetic testing. Enzymology and whole exome sequencing revealed heterozygous missense mutations in exon 10 c.1448T>C (p.L483P) and exon 7 c.928A>G (p.S310G) of GBA1. The latter was first reported in patients with GD. Structural modelling showed that p.S310G and p.L483P were distant from the GCase active site. The p.S310G mutation in domain 1 may decrease stability between the α2 and α3 helices of GBA1. The p.L483P mutation in domain 2 reduced the van der Waals force of the side chain and disrupted the C-terminal ß-sheet. The patient was treated with imiglucerase replacement therapy, and her condition was stable. CONCLUSION: The p.L483P/p.S310G novel compound heterozygous mutation underlies type 1 GD and likely affects GCase protein function. This is the first description of p.S310G being associated with mild type 1 GD in the context of a coinherited p.L483P mutation.

Designing a Polyphosphate Polymorph of CsMg(PO3)3 as Host Lattice for Preparing Single Mn2+-Oxidation Doped Phosphor in the Open Environment.

Within Mn-activated phosphors, the oxidation state of Mn dopant strongly depends on the structural features of the host lattice. This paper reported a new polymorph of CsMg(PO3)3 (CMP) with a complicated three-dimensional (3D) framework of [Mg(PO3)3]∞ that is constructed by MgO6 octahedra and 1D infinite [PO3]∞ chains. Then we prepared a series of red phosphors CsMg1-x(PO3)3:xMn2+ (CMP:xMn2+) by high temperature solid state reactions in the open air. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) studies revealed the single Mn2+-oxidation. Under 404 nm light exciting, CMP:0.2Mn2+ can emit single-band emission at around 630 nm with full-width at half-maximum (fwhm) of 70 nm. Besides, CMP:0.2Mn2+ possesses excellent thermostability up to 450 K. These features indicate that CMP:0.2Mn2+ is suitable to be used for LED backlight display. Moreover, this work suggests that a host lattice with suitable structure feature can form single Mn2+-oxidation and is rigid enough to protect Mn2+ from being oxidized by O2 at high temperature.

The Potential Immunomodulatory Properties of Levornidazole Contribute to Improvement in Experimental Ulcerative Colitis.

The use of an antibiotic with immunomodulatory properties could be fascinating in treating multifactorial inflammatory conditions such as ulcerative colitis (UC). We report our investigations into the immunomodulatory properties of levornidazole, the S-enantiomer of ornidazole, which displayed a tremendous therapeutic potential in UC induced by dextran sodium sulfate (DSS). Levornidazole administration to DSS-colitic mice attenuated the intestinal inflammatory process, with an efficacy better than that shown by 5-amino salicylic acid. This was evidenced by decreased disease activity index, ameliorated macroscopic and microscopic colon damages, and reduced expression of inflammatory cytokines. Additionally, levornidazole displayed anti-inflammatory activity through Caveolin-1-dependent reducing IL-1ß and IL-18 secretion by macrophages contributing to its improvement of the intestinal inflammation, as confirmed in vitro and in vivo. In conclusion, these results pointed out that the immunomodulatory effects of levornidazole played a vital role in ameliorating the intestinal inflammatory process, which would be crucial for the translation of its use into clinical settings.

New red phosphor Na3EuB8O15 with an open-window tubular structure.

A new rare-earth polyborate, trisodium europium octaborate, Na3EuB8O15, was prepared using the high-temperature molten-salt method and structurally determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic space group P-1 and contains a one-dimensional [B8O15]∞ tube structure that is constructed from BO3 and BO4 polyhedra. The Eu3+ and Na+ cations reside in this structure to ensure cohesion and neutrality. The excitation spectra, emission spectra, decay time and Commission Internationale de l'Éclairage (CIE) chromaticity index of Na3EuB8O15 were studied. Under near-UV light excitation (393 nm), the polyborate shows an intense red emission, which mainly originates from the highest intensities of the 5D0→7F1 and 5D0→7F2 transitions.

The effect of Ditylum brightwellii (Bacillariophyceae) on colony development of bloom forming species Phaeocystis globosa (Prymnesiophyceae) under nutrient-replete condition.

To improve our knowledge of the factors regulating Phaeocystis globosa colony formation, the effects of the diatom Ditylum brightwellii on P. globosa colony development were investigated using co-culture and cell-free filtrate approaches. The co-culture experiments showed the moderate abundance of D. brightwellii significantly increased the number and size of colonies, whereas a dramatically decreased effect from high abundance of D. brightwellii. The low abundance of D. brightwellii promoted early formation of P. globosa colony. The cell-free filtrate experiments indicated that culture-filtrates from the exponential phase of D. brightwellii were stimulatory for P. globosa colony formation with more and bigger colonies formed, whereas an inhibitory effect from its senescence phase filtrates. D. brightwellii may influence P. globosa colony formation by regulating the growth of P. globosa solitary cells. Our results suggest that D. brightwellii influences P. globosa colony development, but its effects vary according to its concentrations and growth phases.

Synthesis, crystal structure and luminescence properties of a new samarium borate phosphate, CsNa2Sm2(BO3)(PO4)2.

A new caesium sodium samarium borate phosphate, CsNa2Sm2(BO3)(PO4)2, has been obtained successfully by the high-temperature solution growth (HTSG) method and single-crystal X-ray diffraction analysis reveals that it crystallizes in the orthorhombic space group Cmcm. The structure contains BO3, PO4, NaO7 and SmO7 polyhedra which are interconnected via corner- or edge-sharing O atoms to form a three-dimensional [Na2Sm2(BO3)(PO4)2]∞ network. This network delimits large cavities where large Cs+ cations reside to form the total structure. Under 402 nm light excitation, CsNa2Sm2(BO3)(PO4)2 exhibits three emission bands due to the 4f→4f transitions of Sm3+. Furthermore, we introduced Gd3+ into Sm3+ sites to optimize the Sm3+ concentration and improve the luminescence intensity. The optimal concentration is Gd/Sm = 98/2. The luminescent lifetime of a series of CsNa2Gd2(1-x)Sm2x(BO3)(PO4)2 phosphors shows a gradual degradation of lifetime from 2.196 to 0.872 ms for x = 0.01-0.10. The Commission Internationale de l'Eclairage (CIE) 1931 calculation reveals that CsNa2Gd1.96Sm0.04(BO3)(PO4)2 can emit orange light under 402 nm excitation.

Crystal structure, theoretical studies and luminescent properties of a new borate Na3GdB8O15 with one-dimensional broad-banded anionic framework.

Inorganic borate compounds exhibit significant diversity in their structure types, which are associated with interesting optical and magnetic properties. In our work, a new rare-earth polyborate Na3GdB8O15 was prepared with an infinite one-dimensional (1D) broad-banded framework of [B8O15]∞ running along the a-axis, in which large Gd3+ and Na+ ions reside to ensure cohesion and neutrality of the structure. The basic fundamental building block (FBB) of [B8O15]∞ is B16O32, which is composed of five BO3 and three BO4 groups and can be written as 5Δ3□: 〈2Δ□〉-〈Δ2□〉〈2Δ□〉. First principle studies reveal that Na3GdB8O15 is an indirect bandgap semiconductor and the optical absorption at 280 nm originates from the O2-→ Gd3+ transition. Solid solutions of Na3Gd1-xCexB8O15 and Na3Gd0.98-yYyCe0.02B8O15 were prepared and exhibited a bluish violet emissive luminescence by near-UV excitation due to the 5d1→ 4f1 transition of Ce3+. Substitution of Gd3+ by Y3+ enhanced the luminescence efficiency and significantly improved the thermal stability. At 423 K, the luminescence intensity of Na3Gd0.58Y0.4Ce0.02B8O15 remained 77% of that at 298 K. We hypothesize that Na3GdB8O15 is a potential inorganic luminescent host matrix.

A new langbeinite-type phosphate K2GdHf(PO4)3: synthesis, crystal structure, band structure and luminescence properties.

Langbeinite-type compounds are a large family that include phosphates, sulfates and arsenates, and which are accompanied by interesting physical properties. This work reports a new disordered langbeinite-type compound, K2GdHf(PO4)3 [dipotassium gadolinium hafnium tris(phosphate)], and its structure as determined by single-crystal X-ray diffraction. Theoretical studies reveal that K2GdHf(PO4)3 is an insulator with a direct band gap of 4.600 eV and that the optical transition originates from the O-2p→Hf-5d transition. A Ce3+-doped phosphor, K2Gd0.99Ce0.01Hf(PO4)3, was prepared and its luminescence properties studied. With 324 nm light excitation, a blue emission band was observed due to the 5d1→4f1 transition of Ce3+. The average luminescence lifetime was calculated to be 5.437 µs and the CIE chromaticity coordinates were (0.162, 0.035). One may expect that K2Gd0.99Ce0.01Hf(PO4)3 can be used as a good blue phosphor for three-colour white-light-emitting diodes (WLEDs).

Thermally Stable Phosphor KBa2(PO3)5:Eu2+ with Broad-Band Cyan Emission Caused by Multisite Occupancy of Eu2.

The relationship between the structure and properties is always a hot topic in the luminescent material field. In this work, a new phosphor KBa2(PO3)5:Eu2+ (KBP:Eu) was prepared by a high-temperature solid-state reaction method and characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, photoluminescence (PL), and electroluminescence studies. The polyphosphate host KBP offers three lattice environments (K1, Ba1, and Ba2) for Eu2+ ions to realize broad-band emission from 380 to 700 nm under 345 nm excitation. The distributions of Eu2+ in the three lattice sites can be proven by low-temperature PL and transient fluorescence spectroscopy. Furthermore, temperature-dependent luminescence studies for phosphor KBP:0.02Eu reveal that its luminescence intensity at 150 °C retains about 97% of the initial value at 25 °C. By composing a 365 nm UV chip and KBP:0.02Eu, CaAlSiN3:Eu2+ phosphors, a warm white-light-emitting diode (WLED) was obtained with a correlated color temperature of 5146 K and chromaticity coordinates (0.3404, 0.3384). Therefore, KBP:Eu phosphor is a potential cyan-emitting phosphor used for high-power WLEDs.