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Strigolactones (SLs) are newly discovered plant hormones that modulate a variety of physiological and biochemical processes and plant stress responses. In this study, SLs’ synthetic analog, GR24, significantly improved the growth of tomato seedlings under salt stress, while SLs’ synthesis inhibitor, TIS108, inversed the positive role of SLs, indicating that SLs could effectively enhance salt-stress resistance in tomato. To further explore the mechanism of SL-modulated trehalose (Tre) in response to salt stress, Tre metabolism was analyzed during this process. GR24 increased the endogenous Tre and starch contents and decreased the glucose (Glu) level under salt-stress conditions. Additionally, the TPS and TPP activities were enhanced by GR24 and the activity of THL was inhibited by GR24 under salt stress; thereafter, Tre biosynthesis-related genes, including TPS1, TPS2, TPP1, and TPP2, were also upregulated by GR24 under salt stress. However, the function of GR24 in Tre metabolism was inhibited by TIS108. Thus, the results indicated that GR24 improved the expression levels or activities of Tre biosynthesis-related genes or enzymes and inhibited the transcript level or activity of genes or enzymes related to Tre degradation, respectively, resulting in an increase in the endogenous Tre level and, therefore, weakening the salt toxicity of tomato seedlings.

Recently, tin disulfide (SnS2) has become a hot research focus in various fields due to its advantages of a high transistor switching ratio, an adjustable band gap in visible light range, excellent Li storage performance, sensitive gas recognition, and efficient photocatalytic capability. However, at present, studies of its basic structure mostly stay on the regulation related to the number of layers. To maximize the value of SnS2 in the application design, this paper analyzes the angle-resolved polarized Raman spectra of SnS2 crystals grown under high-temperature sealing systems. Under the parallel scattering configuration test of both the sample basal plane and the cross plane, we observed that how the Raman scattering intensity of the two test planes varies with the polarization angle is different. Combining this experimental result with theory support allows us to reach a conclusion that the differential polarizability of the phonon vibration mode along the z-axis of the cross plane of SnS2 is proven to be the strongest. This finding is expected to provide favorable support for the application of structural regulation of SnS2 and work as a reference for studying other van der Waals layered materials with greater potential.

Two new pyrophosphates nonlinear optical (NLO) materials, Rb3 PbBi(P2 O7 )2 (I) and Cs3 PbBi(P2 O7 )2 (II), were successfully designed and synthesized. Both compounds exhibit large NLO effects and birefringences. Material I presents the scarce case of possessing the coexistence of large birefringence (0.031 at 1064 nm and 0.037 at 532 nm) and second harmonic generation (SHG) response (2.8× potassium dihydrogen phosphate (KDP)) in ultraviolet NLO phosphates and its SHG is the largest in the phase-matching (PM) pyrophosphates. Both I and II have three-dimensional (3D) crystal structures composed of corner-shared RbO12 (CsO11 ), RbO10 (CsO10 ), BiO6 , PbO7 (PbO6 ) and P2 O7 groups, in which P2 O7 and PbO7 (PbO6 ) units form an alveolate [PbPO]∞ skeleton frame. Theoretical calculations reveal that the P-O, Bi-O and Pb-O units are mainly responsible for the moderate birefringence and large SHG efficiency of I.

Background: Early prediction of disease progression in coronavirus disease 2019 (COVID-19) patients can be helpful for personalized therapy, as well as the optimal allocation of public health resources. Objectives: This study aimed to present predictive models for identifying potential high-risk COVID-19 patients upon hospital admission, based on the examination of clinical and radiological features by radiologists and artificial intelligence (AI). Patients and Methods: A total of 786 initially non-severe COVID-19 patients were retrospectively enrolled in this study between January 2 and May 28, 2020. The patients were randomly divided into training (n = 628, 80%) and test (n = 158, 20%) groups. Clinical factors, laboratory indicators, and radiologist- and AI-extracted radiological features of pneumonia lesions were determined using a convolution neural network. The features were selected based on the Boruta algorithm with five-fold cross-validation. Four models, including a model based on clinical findings (model C), a model based on the physician’s examination of radiological features (R-Doc model), a model based on AI-derived radiological features (R-AI model), and an AI-based model mimicking the physician’s examinations (AI-Mimic-Doc model), were constructed for predicting COVID-19 progression upon admission, using a logistic regression analysis. The predictive performance of the four models was evaluated by calculating the area under the receiver operating characteristic (AUC) curve with a 95% confidence interval (95% CI) and then compared using the DeLong test. Results: Overall, 238 out of 786 patients (30.3%) progressed into severe or critical pneumonia during the 14-day follow-up. Nine clinical findings, 17 laboratory indicators, 48 physician-extracted radiological features of pneumonia lesions, and 126 AI-driven radiological features were collected. The urea, albumin level, and lesion size in the basal segment of the right lower lobe of the lung or the proportion of CT values in the range of -200 - 60 in the left lung were the representative features for constructing the R-Doc and R-AI models, respectively. Comparison of the R-Doc model (AUC: 0.840, 95% CI: 0.747 - 0.933 for the training set and 0.731, 95% CI: 0.606 - 0.857 for the test set) with the R-AI model (AUC: 0.803, 95% CI: 0.701 - 0.906 for the training set and AUC: 0.731, 95% CI: 0.606 - 0.857 for the validation set) indicated a marginal difference in identifying patients at risk of progression to pneumonia upon admission (P < 0.1). The R-AI model was superior to model C, with an AUC of 0.770 for the training set (95% CI: 0.657 - 0.882) and 0.666 for the validation set to identify high-risk non-severe cases upon admission. Conclusion: By using radiological features along with blood tests, early identification of COVID-19 patients, who are at risk of disease progression, can be achieved on admission (rapidly by using AI); therefore, the use of these features can contribute to the clinical management of COVID-19.

The first Ba-containing hydrated vanadate as nonlinear optical (NLO) material, BaV2O6·H2O, was synthesized by facile hydrothermal method. The single-crystal X-ray diffraction result shows that this compound crystallizes in the acentric orthorhombic space group of P212121 with cell parameters a = 7.3993(6) A, b = 8.9934(7) A, and c = 9.7206(8) A. UV–vis-IR diffuse reflectance spectrum shows that the compound has a large bandgap of 4.60 eV and moderate transparency range. The title compound shows second-harmonic generation (SHG) efficiency about 0.5 times of KH2PO4 (KDP). The structure-property relationship of BaV2O6·H2O was clarified by the first-principles studies.

Background In December 2019, a rare respiratory disease named coronavirus disease 2019 (COVID-19) broke out, leading to great concern around the world. Purpose To develop and validate a radiomics nomogram for predicting the fatal outcome of COVID-19 pneumonia. Material and Methods The present study consisted of a training dataset (n = 66) and a validation dataset (n = 30) with COVID-19 from January 2020 to March 2020. A radiomics signature was generated using the least absolute shrinkage and selection operator (LASSO) Cox regression model. A radiomics score (Rad-score) was developed from the training cohort. The radiomics model, clinical model, and integrated model were built to assess the association between radiomics signature/clinical characteristics and the mortality of COVID-19 cases. The radiomics signature combined with the Rad-score and the independent clinical factors and radiomics nomogram were constructed. Results Seven stable radiomics features associated with the mortality of COVID-19 were finally selected. A radiomics nomogram was based on a combined model consisting of the radiomics signature and the clinical risk factors indicating optimal predictive performance for the fatal outcome of patients with COVID-19 with a C-index of 0.912 (95% confidence interval [CI] 0.867–0.957) in the training dataset and 0.907 (95% CI 0.849–0.966) in the validation dataset. The calibration curves indicated optimal consistency between the prediction and the observation in both training and validation cohorts. Conclusion The CT-based radiomics nomogram indicated favorable predictive efficacy for the overall survival risk of patients with COVID-19, which could help clinicians intensively follow up high-risk patients and make timely diagnoses.

Supplemental material, sj-pdf-1-acr-10.1177_0284185121994695 for Radiomics analysis enables fatal outcome prediction for hospitalized patients with coronavirus disease 2019 (COVID-19) by Zan Ke, Liang Li, Li Wang, Huan Liu, Xuefang Lu, Feifei Zeng and Yunfei Zha in Acta Radiologica

Superhard materials, which are widely used in metallurgy, petroleum drilling, and mechanical processing, have become the key to the development of processing and manufacturing industry. Boron phosphide is an excellent Superhard candidate material with excellent chemical inertness, high thermal stability and high thermal conductivity. However, since synthesizing BP is a hard task, studies of its basic properties and potential applications are hindered to some extent. Here, we obtained a micron-scale “Tanghulu”, in the process of synthesizing boron phosphide single crystals using high-temperature flux method. Under a special appearance, “Tanghulu” has a complicated structure composed of Superhard boron phosphide single crystal microrod and spherical amorphous SiO2 with a hardness of its body structure up to 40.16 GPa. On the basis of a comprehensive material analysis, we established the formation mechanism of this Superhard “Tanghulu” as follows: during the heating process with continuous high temperature, SiO2 molecules on the wall of quartz tube escape and diffuse freely and adhere to the boron phosphide rod-shaped single crystal, which will aggregate then under the effect of surface tension to form an isotropic spherical amorphous SiO2 and form the “Tanghulu” finally. Our work can help to broaden the understanding of micro-scale materials.

Recently, tin disulfide (SnS

Objective: To explore the clinical characteristics and dynamic follow-up changes of high resolution CT (HRCT) in 270 patients with Coronavirus Disease 2019 (COVID-19) pneumonia.Methods: Two hundred seventy COVID-19 pneumonia patients were retrospectively analyzed, including 146 males and 124 females, with median age of 51 (9,89). The clinical features, laboratory examination indexes and HRCT evolution findings of 270 COVID-19 pneumonia patients were analyzed.Results: 264 cases (95.74%) were positive at the first time nucleic acid test, 6 cases (2.22%) were negative, after multiple inspections, 270 cases (100%) were positive. According to the number of lung segments involved in the lesion, the lesions range from 50% (Critical type). At the first CT exam, 136 cases (50.37%) of the common type, 89 cases (32.96%) of the severe type and 45 cases (16.67%) of the critical type. At the second CT exam, 84 cases (31.11%) of the common type, 103 cases (38.15%) of the severe type and 83 cases (30.74%) of the critical type. In the third CT exam, there were 151 cases (55.93%) of the common type, 86 cases (31.85%) of the severe type and 33 cases (12.22%) of the critical type. The differences in image typing were statistically significant (P < 0.05). During this study, a total of 173 patients (64.08%) were recovered after treatment.Conclusion: In some epidemiological backgrounds, CT imaging manifestations and evolutionary characteristics are of great significance for early warning of lung injury, assessment of disease severity, and assistance in clinical typing and post-treatment follow-up.

Coronavirus disease 2019 (COVID-19) patients were classified into four clinical stages (uncomplicated illness, mild, severe and critical pneumonia) depending on disease severity. We aim to investigate the corresponding clinical, radiological and laboratory characteristics between different clinical stages. A retrospective, single-centre study of 101 confirmed patients with COVID-19 at Renmin Hospital of Wuhan University from 2 January to 28 January 2020 was enrolled; follow-up endpoint was on 8 February 2020. Clinical data were collected and compared during the course of illness. The median age of the 101 patients was 51.0 years and 33.6% were medical staff. Fever (68%), cough (50%) and fatigue (23%) are the most common symptoms. About 26% patients underwent the mechanical ventilation and 98% patients were treated with antibiotics. Thirty-seven per cent patients were cured and 11 died. On admission, the number of patients with uncomplicated illness, mild, severe and critical pneumonia were 2 [2%], 86 [85%], 11 [11%] and 2 [2%]. Forty-four of the 86 mild pneumonia progressed to severe illness within 4 days, with nine patients worsened due to critical pneumonia within 4 days. Two of the 11 severe patients improved to mild condition while three others deteriorated. Significant differences were observed among groups of different clinical stages in numbers of influenced pulmonary segments (6 vs. 12 vs. 17, P < 0.001). A significantly upward trend was witnessed in ground-glass opacities overlapped with striped shadows (33% vs. 42% vs. 55% vs. 80%, P < 0.001), while pure ground-glass opacities gradually decreased as disease progressed (45% vs. 35% vs. 24% vs. 13%, P < 0.001) within 12 days. Lymphocytes, prealbumin and albumin showed a downtrend as disease progressed from mild to severe or critical condition, an uptrend was found in white blood cells, C-reactive protein, neutrophils and lactate dehydrogenase. The proportions of serum amyloid A > 300 mg/l in mild, severe and critical conditions were 18%, 46% and 71%, respectively.

Background: Albeit two months passed since the first case of unexplained pneumonia reported officially, the numbers of infected or died patients with COVID-19 (AU - Ji, Mengyao;Yuan, Lei;Shen, Wei;Lv, Junwei;Li, Yong;Chen, Jia;Liu, Bo;Liang, Zhenzhen;Lin, Qiang;Xie, Wenjie;Li, Ming;Chen, Zhifan;Lu, Xuefang;Ding, Yijuan;An, Ping;Zhu, Sheng;Gao, Mengting;Ni, Hao;Hu, Lanhua;Shi, Guanglei;Dong, Weiguo;Shi, Lei

A new nonlinear optical (NLO) material, namely, BaNaP3O9 was synthesized by high temperature solution method using PbO as the flux. Crystal of BaNaP3O9 with the non-centrosymmetric P212121 space group displays a novel topological three dimensional (3D) structure with tremendous [Ba4Na4O40] 16-membered ring (16-MR) composed by the BaO8, NaO6 polyhedra, which alternately connected each other by sharing two oxygen atoms. The phosphate compound has a short deep-ultraviolet (deep-UV) cut-off edge about 177 nm and shows a second harmonic generation (SHG) response (0.3 × KDP). Some related optical properties and electronic structures derived from first-principles calculations, were explored.

Two new isotypic diphosphates, RbLiZnP2O7 (RLZP) and CsLiZnP2O7 (CLZP), have been synthesized by a high-temperature solid-phase method. They both crystallize in the Pnma space group (No. 62) and have similar crystal configurations. ALiZnP2O7 (A = Rb, Cs) consists of a [Li2Zn2P4O20]14– anionic skeleton, which is composed of Li/ZnO4 tetrahedral and diphosphate groups, and the Rb or Cs atoms are located in the large hole. In this paper, we discuss the structures of the title compounds and isonomic AA′ZnP2O7 (A = alkali metal); it is found that the ionic radii of the cations and bond angles have an effect on the symmetry of the compounds. By analysis, we found that the M/P values have some effect on the dimensionality of the anionic groups in phosphates containing P2O7 groups. Thermal and spectral analyses are carried out on the title compounds. Besides that mentioned above, we also studied the relationship between the electronic structures and optical properties by theoretical calculations.

Superhard materials, which are widely used in metallurgy, petroleum drilling, and mechanical processing, have become the key to the development of processing and manufacturing industry. Boron phosphide is an excellent Superhard candidate material with excellent inert, high thermostability and heat conductivity. However, since synthesizing BP is a hard task, studies of its basic physical properties and applications are hindered to some extent. Here, we obtained a micron-scale “Tanghulu”, in the process of synthesizing boron phosphide single crystals using high-temperature flux method. Under a special appearance, "Tanghulu" is a superhard BP microwire covered by melted or amorphous SiO2 and the hardness of the BP microwires is 40.16GPa. On the basis of a comprehensive material analysis, we established the formation mechanism of this Superhard “Tanghulu” as follows: during the heating process with continuous high temperature, SiO2 molecules on the wall of quartz tube escape and diffuse freely and adhere to the boron phosphide rod-shaped single crystal, which will aggregate then under the effect of surface tension to form an isotropic spherical amorphous SiO2 and form the “Tanghulu” finally. Our work can help to broaden the understanding of micro-scale materials.

The infrared reflectance spectrum of cubic boron phosphide (BP) single crystals shows a very narrow Reststrahlen band, indicating a small TO-LO (transverse optical-longitudinal optical) splitting. To study the phonon thermal behavior of the T O ( Γ ) and the L O ( Γ ) of 10 B P , n a t B P , and 11 B P bulk single crystals, temperature-dependent infrared reflectance spectroscopy in 85–500 K is applied here. As the temperature increases, the Reststrahlen band broadens. The frequencies of the T O ( Γ ) and the L O ( Γ ) exhibit nonlinear red shifts, and the TO-LO splitting gradually increases. Our research found that thermal expansion plays a leading role at low temperatures while phonon anharmonicity gradually takes place at high temperatures.

We report the first vibrational circular dichroism (VCD) measurement of spatial heterogeneity in a sample using infrared (IR) microsampling. Vibrational circular dichroism spectra are typically measured using a standard IR cell with an IR beam diameter of 10 mm or greater making it impossible to investigate the spatial heterogeneity of a solid film sample. We have constructed a VCD sampling assembly with either 3 mm or 1 mm spatial resolution. An XY-translation stage was used to measure spectra at different spatial locations producing IR and VCD maps of the sample. In addition, a rotating sample stage was employed using a dual photoelastic modulator (PEM) setup to suppress artifacts due to linear birefringence in solid-phase or film samples. Infrared and VCD mapping of an insulin fibril film has been carried out at both 3 and 1 mm spatial resolution, and lysozyme films were mapped at 1 mm resolution. The IR spectra of different spots vary in intensity due primarily to sample thickness. The changes in the VCD intensity across the map largely correlate to corresponding changes in the IR map. Closer inspection of the insulin map revealed changes in the relative intensities of the VCD spectra not present in the parent IR spectra, which indicated differences in the degree of supramolecular chirality of the fibrils in the various spatial regions. For lysozyme films, in addition to different degrees of supramolecular chirality, reversal of the net fibril chirality was observed. The large signal-to-noise ratio observed at 1 mm resolution implies the feasibility of further increasing the spatial resolution by one or two orders of magnitude for protein fibril film samples.

Objective: To explore the correlation between diabetic cognitive impairment (DCI) and diabetic retinopathy (DR) through examining the cognitive function and the metabolism of the cerebrum in Type 2 diabetes mellitus (T2DM) by 1H-MRS.Methods: Fifty-three patients with T2DM were enrolled for this study. According to the fundus examination, the patients were divided into the DR group (n = 26) and the T2DM without DR group (T2DM group, n = 27). Thirty healthy adults were selected as a control group (HC group, n = 30). Cognitive function was measured by Montreal Cognitive Assessment (MoCA). The peak areas of N-acetylaspartate (NAA), Cho-line (Cho), Creatine (Cr), and Myo-inositol (mI) as well as their ratios were detected by proton magnetic resonance spectroscopy (1H-MRS). The difference analysis between the three groups was performed by one-way ANOVA. When p < 0.05, LSD-t was applied. A partial correlation analysis (with age as a covariate) was used to analyze the correlation between metabolites in the DR group and MoCA scores. Among all T2DM patients, Chi-square test age, gender, education level, BMI, SBP, DBP, FPG, HbA1c, TC, TG, HDL-C, LDL-C, DR, and DCI correlation were measured. Differences were statistically significant while P < 0.05.Results: 1. The scores of MoCA in the DR group or in the T2DM group were significantly less than those in the HC group (F = 3.54, P < 0.05), and the scores of MoCA in the DR group were significantly less than those in the other groups (F = 3.61, P < 0.05). 2. There were significant differences for NAA in the bilateral hippocampus in DR patients, T2DM patients, and healthy controls (P < 0.05). 3. The NAA/Cr was significantly positively correlated with the score of MoCA in DR patients' left hippocampus (r = 0.781, P < 0.01). 4. Chi-square analysis found that there was a correlation between DR and DCI (x2 = 4.6, df = 1, p = 0.032, plt: 0.05). There was no correlation between other influencing factors and DCI (P > 0.05).Conclusion: DCI is closely correlated with the DR in patients with T2DM. Hippocampal brain metabolism may have some changes in two sides of NAA in patients with DR, 1H-MRS may provide effective imaging strategies and methods for the early diagnosis of brain damage and quantitative assessment cognitive function in T2DM.

Cubic boron phosphide (BP) has the physical advantages of ultra-high hardness, high melting point, and high thermal conductivity, which make it greatly potential in device applications under extreme conditions. However, there are still problems about phonon identification of BP with a curious phenomenon found in the Raman spectra of isotopic lattice (the small peak in the Raman spectra of natBP almost or completely disappears in the Raman spectra of isotopic lattice). Faced with this problem, here we report the extremely narrow reststrahlen bands of natBP, 10BP, and 11BP single crystals via infrared reflectance spectrum different from that of cubic BN, α-GaN, and 4H–SiC, and identify their transverse optical phonon (TO) and longitudinal optical phonon (LO), which breaks traditional understanding in this aspect. Through the classical phonon polariton model fitting, the TO-LO splitting in three BP crystals is calculated less than 3 cm−1, which is attributed to their weak ionicity. This research helps to identify the Raman spectra of BP, where the strongest Raman peak is found as a mixed mode of TO(Γ) and LO(Γ).

For nearly three months, COVID-19 broke out across China and spread around the world [1]. This disease caused varying degrees of illness. The proportion of patients with COVID-19 in the non-severe illness was 84.3% on admission, and severe cases were account for 15.7% [2]. Most of the non-severe pneumonia patients would gradually alleviate and cure during treatment, while others would rapidly progress to severe illness, which had a poor prognosis [3, 4]. As recent reports, the cumulative risk of the composite end point was 3.6% in all the COVID-19 patients, and the cumulative risk was 20.6% [2] for the severe illness., A predictive model for Corona Virus Disease 2019

Phosphates are another new family of exploring deep-ultraviolet nonlinear optical materials. As one material, the simpler the composition is the more favorable synthesis and application is. In this work, a simple alkaline earth metal phosphate β-Ba(PO3)2 was synthesized by high temperature solid phase method. It is worth mentioning that it has short cut-off edge (

Two new isotypic diphosphates, RbLiZnP

Fibrils are β-sheet-rich aggregates that are generally composed of several protofibrils and may adopt variable morphologies, such as twisted ribbons or flat-like sheets. This polymorphism is observed for many different amyloid associated proteins and polypeptides. In a previous study we proposed the existence of another level of amyloid polymorphism, namely, that associated with fibril supramolecular chirality. Two chiral polymorphs of insulin, which can be controllably grown by means of small pH variations, exhibit opposite signs of vibrational circular dichroism (VCD) spectra. Herein, using atomic force microscopy (AFM) and scanning electron microscopy (SEM), we demonstrate that indeed VCD supramolecular chirality is correlated not only by the apparent fibril handedness but also by the sense of supramolecular chirality from a deeper level of chiral organization at the protofilament level of fibril structure. Our microscopic examination indicates that normal VCD fibrils have a left-handed twist, whereas reversed VCD fibrils are flat-like aggregates with no obvious helical twist as imaged by atomic force microscopy or scanning electron microscopy. A scheme is proposed consistent with observed data that features a dynamic equilibrium controlled by pH at the protofilament level between left- and right-twist fibril structures with distinctly different aggregation pathways for left- and right-twisted protofilaments.

Fluorescence quenching processes of poly[2-methoxy-5–(2′ethyl-hexoxy)-p-phenylene vinylene] (MEH-PPV) in solution by electron acceptors, O2 and acid, have been studied. Static quenching of the fluorescence from MEH-PPV by an electron acceptor (DDQ or TCNE) occurs due to electron transfer from MEH-PPV to the electron acceptor and this electron transfer quenching can be promoted by chloroform. Photooxidation takes place in the MEH-PPV solution and singlet oxygen is an intermediate in the photooxidation. according to the results of ESR spectroscopy. Acid also plays an important role in the fluorescence quenching process of MEH-PPV, by the protonation of the alkoxy groups in the molecular chain.

The rotational diffusion of benzo(rst)pentaphene (RST) in n‐hexadecane solvent has been investigated using time‐resolved linear dichroism spectroscopy. Theoretical models of rotational diffusion predict biexponential decays of the observed dichroism for this planar polycyclic aromatic probe in solution. Consistent with theory, two time constants of τ1=12 ±5 and τ2=180±10 ps are observed in the loss of dichroism for RST. The ratio of these two time constants is τ2/τ1≈15 and they occur with approximately equal weights within the decay. Hydrodynamic theory, using either slip or stick boundary conditions, would suggest a ratio of only ca. 2–4. Detailed analysis of the preexponential factors for the decay components according to current hydrodynamic theory reveals that there are no physically allowed conditions that would result in a ratio of time constants that exceed ca. 4 while simultaneously allowing the two exponentials to be observed with nearly equal weights within the decay. Based on this find...

The spectroscopy and fluorescence lifetime of poly[2-methoxy-5-(2′-ethylhexoxy)- p -phenylene vinylene] (MEH-PPV) in mixtures of a poor solvent (cyclohexane or methanol) and a good solvent (chloroform) have been studied. With an increasing proportion of the poor solvent, the absorption, excitation and emission spectra change significantly when the poor solvent proportion is above a critical value. A new component is formed with spectra (absorption, excitation and fluorescence) at longer wavelength (lower energy). Fluorescence decay in different solvents has been measured and the new component has a longer lifetime compared with that in chloroform. All the results illustrate that a new emission center (emitter) is formed when the mixed solvent of MEH-PPV contains a higher proportion of the poor solvent.

The fluorescence emission and X-ray diffraction of magnesium 8-hydroxyquinoline complex (Mgq 2 ) have been measured at high pressure up to 14 GPa. It has been found that pressure can influence the emission dramatically. At relative lower pressure (less than 2.5 GPa) the fluorescence of Mgq 2 changes slightly, but the emission drops quickly with increase of the pressure when the pressure gets higher than 2.5 GPa. The results of in situ energy dispersive X-ray diffraction at high pressure with synchrotron radiation indicate that there is a phase transition at about 2.5–3 GPa for Mgq 2 crystal.