Levels Of Sm Research Articles

Lifetime measurements of odd-parity high-excitation levels of Sm ii by time-resolved laser spectroscopy

Natural radiative lifetimes of 53 odd-parity highly excited levels of singly ionized samarium in the energy range 26 599.08–36 107.66 cm −1 have been measured by the time-resolved laserinduced fluorescence technique in an ionic plume produced by laser ablation. The fundamental frequency and second harmonic of a dye laser have been adopted as the tunable exciting source (308–650 nm), and a fast detection system has been used to record fluorescence signals. The lifetime values obtained in this paper are in the range 10.5–271 ns. A good agreement between the present results and the previously published values was achieved. This work will be useful for investigating the composition of chemically peculiar stars.

Risk of lymph node metastasis in submucosal esophageal cancer: a review of surgically resected patients

Objectives: Endoscopic local procedures are increasingly applied in patients with superficial esophageal cancer as an alternative to radical oncologic resection. The objective of this article is to determine the risk of nodal metastases in submucosal (sm) esophageal cancer, comparing the two predominating histologic tumor types, squamous cell cancer (SCC) and adenocarcinoma (ADC). Methods: A query of PubMed, MEDLINE, Embase and Cochrane Library (1980–2009) using predetermined search terms revealed 675 abstracts, of which 485 full-text articles were reviewed. A total of 105 articles met the selection criteria. A review of article references and consultation with experts revealed additional articles for inclusion. Studies that enrolled patients with submucosal esophageal cancer and provided adequate extractable data were included. Results: The pooled outcomes of 7645 patients with esophageal cancer involving the sm level of infiltration were included in the analysis. Overall, the percentage of lymph node metastasis in submucosal cancer was 37%. Lymph node (N), lymphatic (L) and vascular (V) invasion in sm1 esophageal cancers was 27, 46 and 22%, respectively. Within sm2 lesions, N, L and V invasion were involved in 38, 63 and 38% of patients, respectively. Finally, N, L and V involvement in patients with sm3 lesions was 54, 69 and 47%, respectively. The rates of lymph node metastasis for sm1 and sm2 were higher in SCC compared with ADC, whereas the lymph node metastasis for sm3 was comparable, with >50% involvement in both histologic subtypes. SCC revealed an overall more aggressive behavior compared with ADC (N+: 45 vs 26%; L+: 57 vs 37%; V+: 40 vs 18%). Discussion: While endoscopic therapy may be adequate in selected patients with ‘low-risk’ sm1 ADC, submucosal SCC necessitates esophageal resection and systematic lymphadenectomy because of its aggressive nature and tendency for early metastasis.

Impact of sphingomyelin levels on coronary heart disease and left ventricular systolic function in humans

Sphingomyelin (SM) is an abundant phospholipid in cell membranes and in lipoproteins. In human plasma, SM is mainly found in atherogenic lipoproteins; therefore, higher levels of SM may promote atherogenesis. We investigated the relations between plasma SM levels and the presence of angiographic coronary heart disease (CHD) and left ventricular systolic dysfunction. We studied 732 patients referred for coronary angiography. Median SM levels were higher among patients with CHD and in those with LV systolic dysfunction (LVEF<50%) than in patients without CHD or LV dysfunction. SM levels were significantly correlated with fibrinogen levels, diabetes, apoB, and triglyceride levels. On multivariate analyses, higher median SM levels were associated with a higher risk of CHD and lower LV ejection fraction. The pro-atherogenic property of plasma SM might be related to 1) CHD; 2) LV systolic dysfunction; and 3) metabolism of apoB-containing or triglyceride-rich lipoproteins.

Metal distribution in sediment cores from São Paulo State Coast, Brazil

Ten sediment core samples with lengths ranging from 35 to 100cm were collected in the Baixada Santista region and analyzed to determine As, Br, Co, Cr, Cs, Fe, Rb, Sb, Ta, Th, U, Zn and rare earths (Sc, Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) level concentrations using instrumental neutron activation analysis (INAA). The studied region is located in the southeastern coast of São Paulo State and is comprised of a densely urbanized area, the largest industrial complex of the country, with a predominance of petrochemical and fertilizer plants. It is also home to Brazil’s most important and busiest port. The conclusions found that the As, La, Sm, Ne, Ce, Eu, Hf, Ta, Th, and U elements have a high background level in the region and that Fe and Zn were the main indicators of anthropogenic contribution in the sediments.

Improved RCI techniques for atomic 4f excitation energies: application to Sm I 4f6s2 5DJ levels

We complete the development of a relativistic energy-dependent efficient method by which important pair-correlation effects associated with open subshells can be incorporated into the relativistic configuration interaction (RCI) methodology. We apply this to predict the positions of the 4f6s2 5DJ levels of Sm I. Relative to 5D1, we predict 5D0 lies at −1613 cm−1 and 5D4 at 6589 cm−1. For 5D2 and 5D3, we are 22 cm−1 and 123 cm−1 below the observed difference, respectively. We also calculate magnetic dipole transition rates among these levels and the ground-state 7FJ levels, which may be of interest to future parity nonconservation studies.

Spectroscopic properties of Sm 3+ impurity in YAl 3(BO 3) 4 single crystal

Single crystal of YAl 3(BO 3) 4 (YAB) containing 1 at.% of Sm 3+ was grown by the top seeded high temperature solution method. Optical absorption, excitation and luminescence spectra as well as luminescence decay curves were recorded for this system at 10 K and at room temperature. Crystal field splitting of Sm 3+ multiplets involved in absorption and emission transitions was derived from low temperature optical spectra and used to interpret peculiarities of emission bands. Careful analysis of low temperature optical spectra points to the presence of one type of Sm 3+ site in contrast to two non-equivalent sites reported for Yb 3+:YAB system. It was found that among numerous radiative transitions originating in the single metastable 4G 5/2 level of Sm 3+ the 4G 5/2– 6H 7/2 transition around 598 nm is particularly intense in YAB. The transition terminates on the excited multiplet well above the ground state and thereby is consistent with the four level laser operation scheme. The 4G 5/2 luminescence was found to be long-lived with the lifetime value of 2 ms at room temperature indicating small contribution of non-radiative transitions to the 4G 5/2 relaxation.

Modulation of the activity of cytosolic phospholipase A2α (cPLA2α) by cellular sphingolipids and inhibition of cPLA2α by sphingomyelin

We examined the effect of the cellular sphingolipid level on the release of arachidonic acid (AA) and activity of cytosolic phospholipase A2alpha (cPLA2alpha) using two Chinese hamster ovary (CHO)-K1-derived mutants deficient in sphingolipid synthesis: LY-B cells defective in the LCB1 subunit of serine palmitoyltransferase for de novo synthesis of sphingolipid species, and LY-A cells defective in the ceramide transfer protein CERT for SM synthesis. When LY-B and LY-A cells were cultured in Nutridoma medium and the sphingolipid level was reduced, the release of AA stimulated by the Ca(2+) ionophore A23187 increased 2-fold and 1.7-fold, respectively, compared with that from control cells. The enhancement in LY-B cells was decreased by adding sphingosine and treatment with the cPLA2alpha inhibitor. When CHO cells were treated with an acid sphingomyelinase inhibitor to increase the cellular SM level, the release of AA induced by A23187 or PAF was decreased. In vitro studies were then conducted to test whether SM interacts directly with cPLA2alpha. Phosphatidylcholine vesicles containing SM reduced cPLA2alpha activity. Furthermore, SM disturbed the binding of cPLA2alpha to glycerophospholipids. These results suggest that SM at the biomembrane plays important roles in regulating the cPLA2alpha-dependent release of AA by inhibiting the binding of cPLA2alpha to glycerophospholipids.

Polyunsaturated docosahexaenoic acid suppresses oxidative stress induced endothelial cell calcium influx by altering lipid composition in membrane caveolar rafts

To determine whether DHA suppresses oxidative stress induced endothelial cell calcium influx by altering lipid composition and TRPC1 distribution in membrane rafts. Endothelial cells (EC) were pretreated with DHA or stearic acid, then incubated for another 3h with media containing H(2)O(2). Membrane lipid rafts were isolated using the discontinuous sucrose density gradient ultracentrifugation method. Intracellular calcium was detected with laser scanning confocal microscope. TRPC1 protein in membrane fractions was detected by immunoblotting. Membrane fatty acids compositions were analyzed by gas chromatography; raft cholesterol level was assayed by an Amplex Red Cholesterol Assay kit, and DAG concentration was quantified by a DAG kinase assay. DHA significantly reduced oxidative stress induced calcium influx; pretreated with DHA the n-3 PUFAs were significantly increased in raft fractions, as well as saturated myristic acid, palmitic acid content of membrane rafts in EC; while the stearic acid, monounsaturated oleic acid and cis-oleic acid were decreased. Incubation with DHA also significantly reduced the amount of SM and cholesterol levels in the raft. Interestingly, we fractioned plasma membrane subcellular compartments and discovered that certain amounts of TRPC1 existed in detergent-resistant plasma membrane fractions of EC. After DHA treatment, TRPC1 was partly displaced from lipid raft to detergent-soluble membrane fractions. DHA significantly reduces oxidative stress induced endothelial calcium influx, this effect might be associated with, at least in part, altered raft lipid environment, and suppresses TRPC1-mediated calcium signaling pathway by partially displacing TRPC1 from membrane caveolar lipid rafts.

Composition dependent structural and optical properties of Sm 3+-doped sodium borate and sodium fluoroborate glasses

Sodium borate and fluoroborate glasses doped with trivalent samarium (Sm 3+) were prepared and their detailed spectroscopic analysis was carried out. The FTIR spectra reveal that, the glasses contain BO 3, BO 4, non-bridging oxygen and strong OH − bonds. From the optical absorption spectra, Judd–Ofelt intensity parameters ( Ω λ , λ=2, 4 and 6) have been evaluated and are in turn used to predict radiative properties such as radiative transition probability ( A), stimulated emission cross section ( σ P E ) and branching ratios ( β R) for the excited levels of Sm 3+ ions in sodium borate and sodium fluoroborate glasses. The dependence of the spectral characteristics of Sm 3+ ions due to compositional changes have been examined and reported. The value is found to decrease with the decrease in the sodium content in the glass. The decay from the 4G 5/2 level is found to be non-exponential indicating a cross-relaxation among the Sm 3+ ions.

Luminescence spectroscopy and crystallographic sites of Sm 2+ doped in Sr 6BP 5O 20

Sm 2+-doped strontium borophosphate, Sr 6BP 5O 20, was prepared by high-temperature solid-state reaction method. The photoluminescence excitation and emission spectra together with the decay curves of Sm 2+ ions were investigated from 10 to 300 K. The emission arises from the 5D 0 level of Sm 2+ ions. The investigations were focused mainly on the distribution of Sm 2+ sites in Sr 6BP 5O 20 crystal, which exhibits different spectroscopic features. There exist two isolated Sm 2+ crystallographic sites in Sr 6BP 5O 20 at low temperature (10 K), where no energy transfer could be detected. Only one Sm 2+ site could be detected at high temperature above 100 K. Luminescence and microstructure of Sm 2+ ions were discussed based on the structure of Sr 6BP 5O 20 crystal.

Novel Low Band Gap Small Molecule and Phenylenevinylene Copolymer with Cyanovinylene 4-Nitrophenyl Segments: Synthesis and Application for Efficient Bulk Heterojunction Solar Cells

A novel star-shaped small monomer SM containing a 1,3,5-triazine core and arms with terminal cyanovinylene 4-nitrophenyls was synthesized. Moreover, an alternating p-phenylenevinylene copolymer P containing thiophene with cyanovinylene 4-nitrophenyl side segments was synthesized by Heck coupling. Both SM and P showed broad absorption spectra with long-wavelength maximum at 630−648 nm, which for P is attributable to an intramolecular charge transfer. The optical band gap was 1.57 eV for SM and 1.70 eV for P. Both SM and P were blended with PCBM to study the donor−acceptor interactions on the blend film morphology and device characteristics of organic bulk heterojunction solar cells. A combination of characterization techniques including X-ray diffraction and optical topographical images were used to investigate the film morphology. The HOMO and LUMO levels of both SM and P are well-aligned with those of the PCBM acceptor, allowing efficient electron transfer and suitable open circuit voltage, leading to overall power conversion efficiencies (PCEs) of 2.53 and 1.43% for SM:PCBM and P:PCBM-based devices, respectively. The thermal annealing leads to suitable phase separation due to the increase in crystallinity of donor material and material distribution so that highly effective bulk heterojunction morphologies are obtained which further increases the PCE up to 3.82% and 2.37% for SM:PCBM and P:PCBM-based devices, respectively. These results are preliminary based on the illumination without using a solar simulator.

Sm3+-doped (Ca,Mg,Zr)GGG crystal: A potential reddish-orange laser crystal

Abstract Sm 3+ doped (Ca, Mg, Zr)GGG crystal has been grown by Czochralski technique. Its optical absorption, fluorescence and lifetime were studied. The refractive index and absorption cross-section were calculated. Judd–Ofelt theory was used to calculate the intensity parameters ( Ω t ), the spontaneous emission probabilities, the branching ratios, electric-dipole line strengths, magnetic-dipole line strengths and the radiative lifetime of the state 4 G 5/2 . The stimulated emission cross-sections at 566, 613, 649, and 709 nm were calculated. The decay curve of the 4 G 5/2 level of Sm 3+ ions with relatively low concentration (0.27 mol/L) was nearly single exponential and the experiment fluorescence lifetime ( τ exp ) was determined.

Prediction model of lymph node metastasis in superficial esophageal adenocarcinoma and squamous cell cancer including D2‐40 immunostaining

It was the aim of our study to establish a model for prediction of lymph node metastases in superficial esophageal cancer. We analyzed the clinical and histopathological data of 50 consecutive patients with pT1-esophageal cancer who underwent oncological resection. Submucosal carcinomas (pT1b) were classified according to sm levels 1-3. D2-40 immunostaining was investigated using the ABC technique. In a first step, we performed univariate analysis (One-way ANOVA: Sigma restricted parameterization; test of SS whole vs. SS predicted) to test the predictive value of the following categorical parameters for lymph node status (positive/negative): sex, histologic tumor type, localization, surgical technique (transhiatal/transthoracic), grading, pT1-subclassification (pT1a, pT1b sm 1-3), pL-, pV-status, and D2-40 labeling. Simple regression was applied for the following continuous predictors: age and tumor size. All significant variables of univariate analysis were included in the multivariate analysis. For this purpose, we used the General Liner Models's analysis (forward stepwise). In a third step, the Kruskal-Wallis test with post hoc comparisons was intended to define the cut-off value of parameters tested. Only the following variables gained statistical significance in univariate analysis: sex, histological tumor type, grading, pT1-subclassification, lymphatic infiltration, microvascular infiltration, D2-40 immunostaining, and tumor size (P < 0.05). Variables reaching significance in multivariate analysis were tumor size (P = 0.017) and pV-status (P = 0.037). In the Kruskal-Wallis test with post hoc comparisons, the cut-off value of tumor size was 2 cm (model P = 0.002) and between the categories (P < 0.05). Lymph node positivity and lymphatic vessel infiltration did not linearly increase with sm tumor infiltration depth. The risk category of lymph node involvement in superficial esophageal cancer exists according to our prediction model on the basis of tumor size of >2 cm and microvascular infiltration. The hitherto common sm levels 1-3 classification of submucosal cancers appears to display a lesser impact than previously assumed with regard to prediction of potential lymph node metastases and consequently the indication for endoscopic or surgical therapy.

Correlation between Streptococcus mutans level in saliva and caries status in children

To investigate the distribution pattern of salivary Streptococcus mutans (Sm) level in children and its association with caries status. Three hundred and sixty-five 11- 12-year-old children participated in this study. Scores of decayed, missing or filled teeth (DMFT) for the permanent dentition were recorded. Salivary Sm concentrations were determined by species-specific monoclonal antibodies. Caries-affected children harbored more Sm in saliva [5.53 (1.50, 18.00) x 10(7)/L] than their caries-free counterparts [3.42 (1.60, 8.10) x 10(7)/L] (P = 0.002). Salivary Sm concentration tended to rise with the increase of DMFT score. Spearman's correlation coefficient for Sm concentration was 0.136 (P = 0.010). When salivary Sm concentration reached 8.64 x 10(7)/L, children's caries experience doubled. Salivary Sm level has a skewed distribution among the children studied and associates positively with caries presence. Determination of salivary Sm levels could be used to predict children's caries status.

Opposed circulating plasma levels of endothelin-1 and C-type natriuretic peptide in children with Plasmodium falciparum malaria

BackgroundMolecular mechanisms involved in the pathogenesis of severe Plasmodium falciparum malaria (SM), are not yet fully understood. Both endothelin-1 (ET-1) and C-type natriuretic peptide (CNP) are produced by vascular endothelium and act locally as paracrine regulators of vascular tone, ET-1 being a potent vasoconstrictor and CNP having strong vasorelaxant properties.MethodsPlasma levels of ET-1 and N-terminal fragments of CNP (NT-proCNP) were studied on admission and after 24 hours of treatment, using enzyme-linked-immunosorbent-assay (ELISA) technique, in Gabonese children with severe falciparum malaria (SM, n = 50), with uncomplicated malaria (UM, n = 39) and healthy controls (HC, n = 25).ResultsCompared to HC, malaria patients had significantly higher plasma levels of ET-1 and significantly lower levels of NT-proCNP (p < 0.001 and p < 0.024 respectively). Plasma levels of NT-proCNP were additionally decreased in SM patients compared to HC (p = 0.034), whereas UM was not significantly different to HC. In the SM group we found a trend towards lower ET-1 levels compared to UM (p = 0.085).ConclusionIn the present study, an imbalance between the vasoconstricitve and vasorelaxant endothelium-derived substances ET-1 and CNP in the plasma of children with falciparum malaria is demonstrated, presumably in favor of vasoconstrictive and pro-inflammatory effects. These results may indicate involvement of ET-1 and CNP in malaria pathogenesis. Furthermore, results of lower ET-1 and CNP levels in SM may reflect endothelial cell damage.

Optical properties and spectroscope parameters of Sm(DBM) 3Phen-doped poly(methyl methacrylate)

Rare-earth complex Sm(DBM) 3Phen-doped poly(methyl methacrylate) was synthesized and its absorption and luminescence spectra were studied. The relationship between the coordinate environment of rare-earth ions and the Judd–Ofelt intensity parameter Ω 2 was analyzed and the spectroscopic quality factor, Ω 4/ Ω 6, for this material was reported. The oscillator strengths of higher energy levels of Sm 3+ were predicted, which would be useful to assign the closely spaced multiples at higher energies. The radiative properties for fluorescent levels 4G(4) 7/2, 4F(3) 3/2 and 4G(4) 5/2 of Sm 3+ were evaluated. The predicted radiative parameters were compared with the observed luminescence spectrum of Sm 3+ in this system.

Smooth Muscle Remodeling following surgical reduction of Bladder Capacity: An Animal Model

PURPOSE Studies have shown that a small functional bladder capacity and detrusor overactivity may play an important role in the pathophysiology of nocturnal enuresis. We propose to use an animal model to evaluate bladder functional changes as well as the expression level of smooth muscle myosin in detrusor in response to surgically induced bladder disorders. MATERIAL AND METHODS Adult male Wistar rats underwent either surgical reduction of bladder volume or sham operation ((RBV, n = 6, and SHAM, n = 6, respectively. Animals were kept in metabolic cages at 5th week postoperatively and urine output and voiding frequency were continuously monitored. Animals were then anesthetized and the bladder harvested. For measuring the area of detrusor smooth muscle (DSM) cross-sections of bladder obtained through the mid-portion and stained using Masson's Trichrom stain. Semithin sections of bladder were prepared and immunostained with anti-smooth muscle myosin antibody. RESULTS Our RESULTS demonstrated an increase in smooth muscle bundle size in rats with RBV compared to that of SHAM. Metabolic cage monitoring revealed decreased void volume and increased voiding frequency in RBV group compared to SHAM (Mean: 0.85 ± 0.186 vs 1.75 ± 0.299 ml, 2.53 ± 0.30 vs 0.53 ± 0.05/hr respectively,p < 0.005). Immunostaining with anti-Myosin antibody revealed DSM samples from SHAM and RBV bladders reacted with anti-Myosin antibody. Furthermore, the intensity of the staining is higher for the DSM sample from SHAM compared to that of RBV. CONCLUSIONS Our RESULTS demonstrate bladder dysfunction elicited by surgical reduction of bladder capacity can induce detrusor smooth muscle proliferation in rats. Alteration in expression of myosin in DSM from RBV group implicates the alteration of myosin isoform composition in response to bladder disorders. Our current research is focusing the expression levels of myosin heavy chain isoforms SM - A and SM-B at protein level in detrusor under normal and pathological conditions.

Chronic administration of DHA and UMP improves the impaired memory of environmentally impoverished rats

Living in an enriched environment (EC) during development enhances memory function in adulthood; living in an impoverished environment (IC) impairs memory function. Compounds previously demonstrated to improve memory among IC rats include CDP-choline and uridine monophosphate (UMP). Brain phosphatidylcholine (PC) synthesis utilizes both the uridine formed from the metabolism of exogenous CDP-choline and UMP, and the choline formed from that of CDP-choline. It also uses the polyunsaturated fatty acid (PUFA) DHA, a precursor for the diacylglycerol incorporated into PC. DHA administration also improves cognition in young and aged rodents and humans; its effects on cognitively impaired IC rats have not been characterized. We have thus examined the consequences of administering DHA (300 mg/kg) by gavage, UMP (0.5% in the diet), or both compounds on hippocampal- and striatal-dependent forms of memory among rats exposed to EC or IC conditions for 1 month starting at weaning, and consuming a choline-containing diet. We observe that giving IC rats either dietary UMP or gavaged DHA improves performance on the hidden version of the Morris water maze (all P < 0.05), a hippocampal-dependent task; co-administration of both phosphatide precursors further enhances the IC rats’ performance on this task ( P < 0.001). Neither UMP nor DHA, nor giving both compounds, affects the performance of EC rats on the hidden version of the Morris water maze ( P > 0.05), nor the performance by IC or EC rats on the visible version of the Morris water maze (all P > 0.05), a striatal-dependent task. We confirm that co-administration of UMP and DHA to rats increases brain levels of the phosphatides PC, PE, SM, PS, PI, and total brain phospholipid levels (all P < 0.05), and show that rearing animals in an enriched environment also elevates brain PC, PS, and PI levels (all P < 0.01) and total brain phospholipids ( P < 0.01) compared with their levels in animals reared in an IC environment. These findings suggest that giving DHA plus UMP can ameliorate memory deficits associated with rearing under impoverished conditions, and that this effect may be mediated in part through enhanced synthesis of brain membrane phosphatides.

Interaction with stressed mothers affects corticosterone levels in pups after reunion and impairs the response to dexamethasone in adult mice

Early adverse experiences are preeminent factors for the development of affective disorders. In the present study, we analyzed the effects of different postnatal manipulations applied either on the mother or on the offspring in mice. Maternal behavior and adrenocortical activity of both mothers and offspring at the end of postnatal stress and at adulthood were considered. From postnatal day (PND) 1 to 14 mice underwent 15min of: (a) brief (15min) pups' exposure to clean bedding (CB: clean bedding), (b) mothers' exposure to the odor of a novel male (SM: stressed mother) or (c) mothers' exposure to a clean cage (CSM: control stressed mother), and (d) standard rearing (N-H: non-handled). The behavior of mouse dams during and after stress sessions was analyzed. Serum corticosterone of mothers and pups at the end of the stress session and 30min after reunion was assessed on PND 14. Moreover, anxiety levels and HPA-axis inhibitory feedback in response to dexamethasone administration were evaluated in adult male offspring. Overall, during the 14 days of treatment CB mothers when reunited with their pups showed higher maternal behavior than other dams. After the last stress (PND 14) SM and CSM maternal corticosterone levels increased as well as those of CB pups. While 30min of mother-infant interaction restored baseline corticosterone levels in SM and CSM mothers and in CB pups, SM and CSM offspring showed a decrease of corticosterone under baseline levels. At adulthood, SM and CSM males did not show the suppressive hormonal response to dexamethasone treatment. Moreover, adult CB and SM male mice displayed decreased anxiety in the open field. Maternal psychosocial stress during lactation seems to permanently affect the offspring's HPA functioning. These effects may be dissociated from the behavioral response as suggested by the decrease of anxiety in SM and CB adult mice.

Effect of pressure on luminescence properties of Sm 3+ ions in potassium niobate tellurite glass

Emission spectra and decay properties of the 4G 5/2 level of Sm 3+ ions in TeO 2+K 2O+Nb 2O 5 glass have been measured as a function of pressure upto 14.6 GPa at room temperature. A progressive red shift in the barycentres of 4G 5/2→ 6H J ( J=9/2, 7/2 and 5/2) emission bands and increase in splitting of these bands have been observed with increasing pressure. The luminescence decay profile of the 4G 5/2 level at ambient condition shows a nearly single exponential nature and with increase in pressure it becomes gradually non-exponential associated with a decrease in lifetime. The non-exponential decay curves are well-fitted to the Inokuti–Hirayama model for S=6, indicating that the interaction for cross-relaxation energy transfer between Sm 3+ ions is of dipole–dipole type. The results obtained after release of pressure reveal that there is a small hysteresis.