[Diagnostic Value of Ultrasound for Thyroid Nodules With a Spoke-Wheel Blood Flow Pattern].

Objective To explore the diagnostic value of ultrasound for thyroid nodules with a spoke-wheel blood flow pattern.Methods The clinical data of the patients with thyroid nodules presenting a spoke-wheel blood flow pattern examined by ultrasound were collected,and the gray-scale ultrasound features of the nodules were recorded.The diagnostic performance of the Thyroid Imaging Reporting and Data System by American College of Radiology (ACR TI-RADS),Chinese Thyroid Imaging Reporting and Data System (C-TIRADS),and combined specific indicators for the thyroid nodules with a spoke-wheel blood flow pattern was evaluated by comparison with the pathological results,which was regarded as the gold standard.Results A total of 64 patients with thyroid nodules were finally included,including 47 patients with malignant nodules and 17 patients with benign nodules.In addition to the general ultrasound features,central scar mostly appeared in malignant nodules (χ2=5.968,P=0.015),while central coarse calcification was more common in benign nodules (χ2=10.899,P=0.001).After the combination of central scar and central gross calcification,the diagnostic performance of ACR TI-RADS and C-TIRADS was improved (both P<0.001).Conclusions When the thyroid nodule shows a spoke-wheel blood flow pattern,one should be cautious of the possibility of malignancy.Combining central scar and central coarse calcification can improve the accuracy of ultrasonic diagnosis.

An in vitro and in vivo study of the role of long non-coding RNA-HOST2 in the proliferation, migration, and invasion of human glioma cells.

Gliomas are the most commonly occurring primary malignant brain tumors in the central nervous system of adults. They are rarely curable and the prognosis for high grade gliomas is generally poor. Recently, long non-coding RNA (lncRNA) human ovarian cancer-specific transcript 2 (HOST2) has been reported to be expressed at high levels in human ovarian cancer, involving tumorigenesis. However, little is still known about whether and how HOST2 regulates glioma development and progression. Therefore, this study aims to investigate the role of HOST2 in human glioma cells. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to determine the expression of lncRNA HOST2, let-7b, and PBX3 in human glioma cells. Cultured human glioma cells were treated with siRNA (si)-lncRNA HOST2, let-7b mimic, si-lncRNA HOST2 + let-7b inhibitor, and si-PBX3. Parameters including cell viability, colony formation, cell migration, and cell invasion were detected by cell counting kit-8 assay, colony formation assay, scratch test, and Transwell assay respectively to determine the effects of down-regulated HOST2 on glioma cells. Tumor formation in nude mice was evaluated by subcutaneous tumor formation experiment. Results showed that HOST2 and PBX3 were highly expressed in glioma tissue whereas let-7b was expressed at much lower levels. In response to treatment with si-lncRNA HOST2, si-PBX3, and let-7b mimic, glioma cell lines exhibited decreased cell viability, suppressed cell migration, invasion, and reduced colony formation of glioma cells. This was accompanied by an attenuated tumor formation with smaller volume and weight in nude mice, suggesting that down-regulated HOST2 could inhibit the tumorigenicity of glioma cells. Lastly, we found that lncRNA HOST2 was highly expressed in glioma tissues and its down-regulation could inhibit the growth and invasion of glioma cells. © 2018 IUBMB Life, 71(1):93-104, 2019.

Effects of ultrasonic and microwave pretreatments on lipid extraction of microalgae.

The extraction of lipids from microalgal cells using ultrasonic and microwave pretreatments is mechanistically evaluated based on the distribution of cell fragments, the lipid content analysis, the scanning electron microscopic (SEM) observation of ruptured microalgal cells, and the analysis of fatty acids. The results indicate that microwave pretreatment extracts lipids more rapidly and efficiently as compared to ultrasonic pretreatment. The rupture of cells in the microwave process is due to the tremendous pressure caused by the rapid heating of the moisture inside the microalgal cells, whereas in the ultrasonic process the microalgal cells are ruptured by shock waves from cavitation bubbles outside the cells. The fatty acid composition of the respective lipids extracted via the two types of pretreatment did not vary significantly from one another. These results demonstrate that the microwave process is rapid and more effective than the ultrasonic process for lipid extraction from microalgae.

Effects of carbonization parameters of Moso-bamboo-based porous charcoal on capturing carbon dioxide.

This study experimentally analyzed the carbon dioxide adsorption capacity of Moso-bamboo- (Phyllostachys edulis-) based porous charcoal. The porous charcoal was prepared at various carbonization temperatures and ground into powders with 60, 100, and 170 meshes, respectively. In order to understand the adsorption characteristics of porous charcoal, its fundamental properties, namely, charcoal yield, ash content, pH value, Brunauer-Emmett-Teller (BET) surface area, iodine number, pore volume, and powder size, were analyzed. The results show that when the carbonization temperature was increased, the charcoal yield decreased and the pH value increased. Moreover, the bamboo carbonized at a temperature of 1000(°)C for 2 h had the highest iodine sorption value and BET surface area. In the experiments, charcoal powders prepared at various carbonization temperatures were used to adsorb 1.854% CO2 for 120 h. The results show that the bamboo charcoal carbonized at 1000(°)C and ground with a 170 mesh had the best adsorpt on capacity, significantly decreasing the CO2 concentration to 0.836%. At room temperature and atmospheric pressure, the Moso-bamboo-based porous charcoal exhibited much better CO2 adsorption capacity compared to that of commercially available 350-mesh activated carbon.

Dye molecular structure device open-circuit voltage correlation in Ru(II) sensitizers with heteroleptic tridentate chelates for dye-sensitized solar cells.

Dicarboxyterpyridine chelates with π-conjugated pendant groups attached at the 5- or 6-position of the terminal pyridyl unit were synthesized. Together with 2,6-bis(5-pyrazolyl)pyridine, these were used successfully to prepare a series of novel heteroleptic, bis-tridentate Ru(II) sensitizers, denoted as TF-11-14. These dyes show excellent performance in dye-sensitized solar cells (DSCs) under AM1.5G simulated sunlight at a light intensity of 100 mW cm(-2) in comparison with a reference device containing [Ru(Htctpy)(NCS)(3)][TBA](3) (N749), where H(3)tctpy and TBA are 4,4',4"-tricarboxy-2,2':6',2"-terpyridine and tetra-n-butylammonium cation, respectively. In particular, the sensitizer TF-12 gave a short-circuit photocurrent of 19.0 mA cm(-2), an open-circuit voltage (V(OC)) of 0.71 V, and a fill factor of 0.68, affording an overall conversion efficiency of 9.21%. The increased conjugation conferred to the TF dyes by the addition of the π-conjugated pendant groups increases both their light-harvesting and photovoltaic energy conversion capability in comparison with N749. Detailed recombination processes in these devices were probed by various spectroscopic and dynamics measurements, and a clear correlation between the device V(OC) and the cell electron lifetime was established. In agreement with several other recent studies, the results demonstrate that high efficiencies can also be achieved with Ru(II) sensitizers that do not contain thiocyanate ancillaries. This bis-tridentate, dual-carboxy anchor configuration thus serves as a prototype for future omnibearing design of highly efficient Ru(II) sensitizers suited for use in DSCs.

The empirical correlation between hydrogen bonding strength and excited-state intramolecular proton transfer in 2-pyridyl pyrazoles.

A series of 2-pyridyl pyrazoles 1a and 1-5 with various functional groups attached to either pyrazole or pyridyl moieties have been strategically designed and synthesized in an aim to probe the hydrogen bonding strength in the ground state versus dynamics of excited-state intramolecular proton transfer (ESIPT) reaction. The title compounds all possess a five-membered-ring (pyrazole)N-H···N(pyridine) intramolecular hydrogen bond, in which both the N-H bond and the electron density distribution of the pyridyl nitrogen lone-pair electrons are rather directional, so that the hydrogen bonding strength is relatively weak, which is sensitive to the perturbation of subtle chemical substitution and consequently reflected from the associated ESIPT dynamics. Various approaches such as (1)H NMR (N-H proton) to probe the hydrogen bonding strength and absorption titration to assess the acidity-basicity property were made for all the title analogues. The results, together with supplementary support provided by a computational approach, affirm that the increase of acidity (basicity) on the hydrogen bonding donor (acceptor) sites leads to an increase of hydrogen-bonding strength among the title 2-pyridyl pyrazoles. Luminescence results and the associated ESIPT dynamics further reveal an empirical correlation in that the increase of the hydrogen bonding strength leads to an increase of the rate of ESIPT for the title 2-pyridyl pyrazoles, demonstrating an interesting relationship among N-H acidity, hydrogen bonding strength, and the associated ESIPT rate.

Establishing a rabbit model of perianal fistulizing Crohn's disease.

BACKGROUND: Crohn's disease (CD) is a chronic nonspecific intestinal inflammatory disease. The aetiology and pathogenesis of CD are still unclear. Anal fistula is the main complication of CD and is a difficult problem to solve at present. The main limitation of developing new therapies is bound up with the short of preclinical security and effectiveness data. Therefore, an ideal animal model is needed to establish persistent anal fistula and an inflamed rectal mucosa. AIM: To improve the induction method of colitis and establish a reliable and reproducible perianal fistulizing Crohn's disease animal model to evaluate new treatment strategies. METHODS: Twenty male New Zealand rabbits underwent rectal enema with different doses of 2,4,6-trinitrobenzene sulfonic acid to induce proctitis. Group A was treated with an improved equal interval small dose increasing method. The dosage of group B was constant. Seven days later, the rabbits underwent surgical creation of a transsphincteric fistula. Then, three rabbits were randomly selected from each group every 7 d to remove the seton from the fistula. The rabbits were examined by endoscopy every 7 days, and biopsy forceps were used to obtain tissue samples from the obvious colon lesions for histological analysis. The disease activity index (DAI), colonoscopy and histological scores were recorded. Perianal endoscopic ultrasonography (EUS) was used to evaluate the healing of fistulas. RESULTS: Except for the DAI score, the colonoscopy and histological scores in group A were significantly higher than those in group B (P < 0.05). In the ideal model rabbit group, on the 7th day after the removal of the seton, all animals had persistent lumens on EUS imaging, showing continuous full-thickness high signals. Histological inspection of the fistula showed acute and chronic inflammation, fibrosis, epithelialization and peripheral proctitis of the adjoining rectum. CONCLUSION: The improved method of CD colitis induction successfully established a rabbit perianal fistula CD preclinical model, which was confirmed by endoscopy and pathology.

CBX2 and EZH2 cooperatively promote the growth and metastasis of lung adenocarcinoma.

The disruption of epigenetic regulation is common in tumors; the abnormal expression of epigenetic factors leads to cancer occurrence and development. In this study, to investigate the potential function of histone methylation regulators in lung adenocarcinoma (LUAD), we performed differential expression analysis using RNA-seq data downloaded from The Cancer Genome Atlas (TCGA) database, and identified CBX2 and EZH2 as obviously upregulated histone methylation regulators. CBX2 knockdown significantly inhibited LUAD cell growth and metastasis in vitro and in vivo. The combined high expression of CBX2 and EZH2 was an indicator of poor prognosis in LUAD. The inhibition of both CBX2 and EZH2 exerted cooperative suppressive effects on the growth and metastasis of LUAD cells. Mechanistically, we revealed that CBX2 and EZH2 downregulated several PPAR signaling pathway genes and tumor suppressor genes through binding to their promoter cooperatively or separately. Furthermore, knockdown of CBX2 improved the therapeutic efficiency of EZH2 inhibitor on A549 cells. Our study reveals the cooperative oncogenic role of CBX2 and EZH2 in promoting LUAD progression, thereby providing potential targets for LUAD diagnosis and therapy.

A novel missense mutation of the ATP2C1 gene in a Chinese patient with Hailey-Hailey disease.

Benign familial chronic pemphigus (Hailey-Hailey disease, HHD; MIM 169600) is a rare autosomal dominant hereditary disorder characterized by pruritic vesicles, painful erosions and scaly erythematous plaques at the sites of friction and flexures. Mutations in ATP2C1, which encoding the human secretory pathway Ca²(+)/Mn²(+)-ATPase protein 1 (hSPCA1), have been identified as the pathogenic gene of HHD. We found a novel, distinct, heterozygous mutation during study of a Chinese patient with HHD. We identified a C→T transition at nucleotide 1235 (p.Thr352IIe), in exon 13 of ATP2C1. This observation would be useful for genetic counseling and prenatal diagnosis for affected families and in expanding the repertoire of ATP2C1 mutations underlying HHD.

PRIMO/PRIMONA: a coarse-grained model for proteins and nucleic acids that preserves near-atomistic accuracy.

The new coarse graining model PRIMO/PRIMONA for proteins and nucleic acids is proposed. This model combines one to several heavy atoms into coarse-grained sites that are chosen to allow an analytical, high-resolution reconstruction of all-atom models based on molecular bonding geometry constraints. The accuracy of proposed reconstruction method in terms of structure and energetics is tested and compared with other popular reconstruction methods for a variety of protein and nucleic acid test sets.

Homoleptic tris(pyridyl pyrazolate) Ir(III) complexes: en route to highly efficient phosphorescent OLEDs.

Treatment of the metal reagent IrCl(3)nH(2)O with two equivalents of 2-pyridyl pyrazole (N;N)H (3-tert-butyl-5-(2-pyridyl) pyrazole, (bppz)H and 3-trifluoromethyl-5-(2-pyridyl) pyrazole, (fppz)H), afforded the isomeric Ir(III) metal complexes with a general formula cis-[Ir(bppz)(2)Cl(2)]H (2 a), trans-[Ir(bppz)(2)Cl(2)]H (3 a), cis-[Ir(fppz)(2)Cl(2)]H (2 b), and trans-[Ir(fppz)(2)Cl(2)]H (3 b). Single-crystal X-ray diffraction studies on 2 b and 3 a revealed the coexistence of two pyrazolate chelates and two terminal chloride ligands on the coordination sphere. Subsequent reactivity studies confirmed their intermediacy to the preparation of homoleptic mer-[Ir(bppz)(3)] (1 a) and mer-[Ir(fppz)(3)] (1 b) that showed dual intraligand and ligand-to-ligand charge-transfer phosphorescence at room temperature. To attain bright, room-temperature phosphorescence further, we then synthesized two isoquinolinyl pyrazolate complexes, mer-[Ir(bipz)(3)] (4 a) and mer-[Ir(fipz)(3)] (4 b) ((bipz)H=3-tert-butyl-5-(1-isoquinolyl) pyrazole and (fipz)H=3-trifluoromethyl-5-(1-isoquinolyl) pyrazole). Their orange luminescence is mainly attributed to the mixed MLCT/pipi* transition, and the quantum yields were as high as 86 (4 a) and 50 % (4 b) in degassed CH(2)Cl(2) solution at RT. The organic light-emitting diodes (OLEDs) were then fabricated by using 4 a as a dopant, giving orange luminescence with CIE(x,y)=0.55, 0.45 (CIE(x,y)=the 1931 Commission Internationale de L'Eclairage (x,y) coordinates) and peak efficiencies of 14.6 % photon/electron, 34.8 cd A(-1), 26.1 lm W(-1). The device data were then compared with the previously reported heteroleptic complex [Ir(dfpz)(2)(bipz)] (5) ((dfpz)H=1-(2,4-difluorophenyl) pyrazole), revealing the possible effect of the bipz chelate and phosphor design on the overall electrophosphorescent performance, which can be understood by the differences in the carrier-transport properties.

Mono- versus dinuclear Pt(II) 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine complexes: synthesis, characterization, and remarkable difference in luminescent properties.

A series of charge-neutral mononuclear Pt(II) complexes Pt(fpbpy)(pz) (3a), Pt(fpbpy)(dmpz) (4a), Pt(fpbpy)(dbpz) (5a), and Pt(fpbpy)(dtfpz) (6a), fpbpyH = 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine, pzH = pyrazole, dmpzH = 3,5-dimethylpyrazole, dbpzH = 3,5-di-tert-butylpyrazole, and dtfpzH = 3,5-bis(trifluoromethyl)pyrazole, and the cationic Pt(II) dimer [{Pt(fpbpy)}(2)(mu-pz)](+) (3b), [{Pt(fpbpy)}(2)(mu-dmpz)](+) (4b), and [{Pt(fpbpy)}(2)(mu-dbpz)](+) (5b) were synthesized. Series a mononuclear complexes reveal two distinctive ligand arrangements. As unveiled by X-ray crystallography, 3a exhibits a nearly perfect planar geometry, while structural determination on 6a shows a perpendicular arrangement of dbpz ligand due to steric congestion. In sharp contrast, the dinuclear complexes, exemplified by 4b and 5b, display an intramolecular Pt...Pt separation of 3.601 and 3.403 A, respectively. As for photophysical properties, the structural variation leads to a salient difference in emission features between 3a (580 nm) and 6a (510 nm). The results are rationalized by the contribution of ligand-to-ligand charge transfer and intraligand pi-pi* transition for 3a and 6a in the lowest-lying excited state, respectively. On the other hand, dinuclear complexes 3b and 4b reveal dual phosphorescence (denoted as P(1) and P(2) bands), for which the short wavelength emission (the P(1) band) is akin to that observed for the intraligand pi-pi* transition of 6a, while the much red-shifted, broad emission (the P(2) band) is attributed to the formation of intramolecular ligand-metal-to-metal charge transfer excimer transition. Further studies of relaxation dynamics on both 3b and 4b showed fast excited-state equilibrium between the P(1) and P(2) bands. In contrast, only the P(2) emission band was resolved for 5b, indicating its exergonic excimer formation. Supplementary support of the excited-state thermodynamics is also provided by time-dependent density functional theory calculations, incorporating both geometry optimized S(0) and T(1) states.

New series of ruthenium(II) and osmium(II) complexes showing solid-state phosphorescence in far-visible and near-infrared.

A new Ru(II) complex, [Ru(fpbpymH)(2)]Cl(2) (1), in which fpbpymH = [5-(trifluoromethyl)pyrazol-3-yl](2,2'-bipyrid-6-yl)methane, was prepared by the treatment of [Ru(DMSO)(4)Cl(2)] with 2 equiv of the terdentate chelate fpbpymH in refluxing ethanol. A single-crystal X-ray diffraction study of 1 revealed a distorted octahedral Ru(II) framework, showing strong N-H...Cl hydrogen bonding between the fpbpymH ligand and Cl anions. In the presence of Na(2)CO(3), the methylene linkers of chelates in 1 underwent stepwise oxygenation, forming the charge-neutral complexes [Ru(fpbpym)(fpbpyk)] (2) and [Ru(fpbpyk)(2)] (3) [fpbpykH = [5-(trifluoromethyl)pyrazol-3-yl](2,2'-bipyrid-6-yl) ketone] in sequence. The respective charge-neutral Os(II) complex [Os(fpbpyk)(2)] (4) was also isolated by the treatment of OsCl(3).3H(2)O with 2 equiv of the terdentate chelate fpbpymH. Electrochemical analysis indicated that the introduction of the electron-withdrawing ketone group in 2-4 increased the metal-based oxidation potential in sequence. For the photophysical properties, complexes 1-4 are essentially nonluminescent in solution (e.g., CH(2)Cl(2) or MeOH) at room temperature, but all exhibit 600-1100 nm phosphorescence with moderate intensity for the powdery, solid sample at room temperature. The trend in terms of the emission peak wavelength of 1 (666 nm) < 3 (795 nm) < 2 (810 nm) < 4 (994 nm) among titled complexes is in agreement with the corresponding onset of absorption spectra as well as the time-dependent density functional theory calculation of 1 < 3 < 2 < 4.

Authentic-blue phosphorescent iridium(III) complexes bearing both hydride and benzyl diphenylphosphine; control of the emission efficiency by ligand coordination geometry.

Sequential treatment of IrCl(3) x nH(2)O with 2 equiv of benzyl diphenylphosphine (bdpH) and then 1 equiv of 3-trifluoromethyl-5-(2-pyridyl) pyrazole (fppzH) in 2-methoxyethanol gave formation to three isomeric complexes with formula [Ir(bdp)(fppz)(bdpH)H] (1-3). Their molecular structures were established by single crystal X-ray diffraction studies, showing existence of one monodentate phosphine bdpH, one terminal hydride, a cyclometalated bdp chelate, and a fppz chelate. Variation of the metal-ligand bond distances showed good agreement with those predicted by the trans effect. Raman spectroscopic analyses and the corresponding photophysical data are also recorded and compared. Among all isomers complex 1 showed the worst emission efficiency, while complexes 2 and 3 exhibited the greatest luminescent efficiency in solid state and in degassed CH(2)Cl(2) solution at room temperature, respectively. This structural relationship could be due to the simultaneously weakened hydride and the monodentate bdpH bonding that are destabilized by the trans-pyrazolate anion and cyclometalated benzyl group, respectively.

Donor-acceptor interactions in red-emitting thienylbenzene-branched dendrimers with benzothiadiazole core.

Synthesis and characterization of dendrimers containing thienylbenzene repeating units, red-emitting benzothiadiazole core, and triarylamine peripheries that bear naphthyl units are reported. The relevant dendrimers of different generations are classified as G(nb) (n=1-3), while the tert-butyl dendrimers G(na) with the acceptor alone were also synthesized to serve as control chromophores that avoid donor-acceptor interactions. The resulting dendrimers are capable of harvesting photon energy through efficient energy transfer among donor-acceptor moieties, so that highly luminescent red fluorophores result. Transient fluorescence studies suggest that the energy transfer and its efficiency are approximately unity in all G(a) dendrimers, whereas the rate of energy transfer for the G(b) dendrimers is suppressed, that is, charge transfer from the core to the periphery is a significant quenching pathway. These dendrimers are amorphous in nature with high glass transition temperatures (176-201 degrees C). Electroluminescent devices were fabricated by using the dendrimers as hole-transporting emitters, and the devices exhibit promising red emission parameters.

Excited-state double proton transfer in model base pairs: the stepwise reaction on the heterodimer of 7-azaindole analogues.

A four fused-ring system 11-propyl-6H-indolo[2,3-b]quinoline (6 HIQ) is strategically designed and synthesized; it possesses a central moiety of 7-azaindole (7AI) and undergoes excited-state double proton transfer (ESDPT). Despite a barrierless type of ESDPT in the 6 HIQ dimer, femtosecond dynamics and a kinetic isotope effect provide indications for a stepwise ESDPT process in the 6 HIQ/7AI heterodimer, in which 6 HIQ (deuterated 6 HIQ) delivers the pyrrolyl proton (deuteron) to 7AI (deuterated 7AI) in less than 150 fs, forming an intermediate with a charge-transfer-like ion pair, followed by the transfer of a pyrrolyl proton (deuteron) from cation-like 7AI (deuterated 7AI) to the pyridinyl nitrogen of the anion-like 6 HIQ (deuterated 6 HIQ) in approximately 1.5+/-0.3 ps (3.5+/-0.3 ps). The barrier of second proton transfer is estimated to be 2.86 kcal mol(-1) for the 6 HIQ/7AI heterodimer.

Spectroscopy and femtosecond dynamics of excited-state proton transfer induced charge transfer reaction.

Fluorescence spectroscopy and femtosecond relaxation dynamics of 2-{[2-(2-hydroxyphenyl)benzo[d]oxazol-6-yl]methylene}malononitrile (diCN-HBO) and 2-{[2-(2-hydroxyphenyl)benzo[d]thiazol-6-yl]methylene}malononitrile (diCN-HBT) are studied to probe the excited-state proton transfer (ESPT) coupled charge transfer (ESCT) reaction. Unlike most of the ESPT/ESCT systems previously designed, in which ESCT takes place prior to ESPT, both diCN-HBO and diCN-HBT undergo ESPT, concomitantly accompanied with the charge transfer process, such that the ESPT reaction dynamics are directly coupled with solvent polarization effects. The long-range solvent polarization interactions result in a solvent-induced barrier that affects the overall proton transfer reaction rate. In cyclohexane, the rate constant of ESPT of diCN-HBO is measured to be 1.1 ps (9.1 x 10(11) s(-1)), which is apparently slower than that of 150 fs for the parent molecule 2-(2'-hydroxyphenyl)benzoxazole (HBO). Upon increasing solvent polarity to, for example, CH 3CN, the rate of ESPT is increased to 300 fs (3.3 x 10(12) s(-1)). The results are rationalized by the stabilization of proton transfer tautomer, which possesses a large degree of charge transfer character via an increase of the solvent polarity, such that the corresponding solvent-induced barrier is reduced. We thus demonstrate a prototypical system in which the photon-induced nuclear motion (proton transfer) is directly coupled with solvent polarization and the corresponding mechanism is reminiscent of that applied in an electron transfer process.

The empirical correlation between size and two-photon absorption cross section of CdSe and CdTe quantum dots.

The tuning of CdSe quantum dot (QDs) sizes, and consequently their corresponding two-photon absorption (TPA) cross section, has been systematically investigated. As the size (diameter) of the quantum dots increases, the TPA cross section is found to be empirically related via a power-law proportionality of 3.5+/-0.5 and 5.6+/-0.7 to the diameters of CdSe and CdTe QDs, respectively. The results are tentatively rationalized via a theoretical model of two-photon excitation properties in a system incorporating excitons and defects.

Extensive spectral tuning of the proton transfer emission from 550 to 675 nm via a rational derivatization of 10-hydroxybenzo[h]quinoline.

Via a systematic derivatization of the excited-state intramolecular proton-transfer system, 10-hydroxybenzo[h] quinoline, the proton-transfer emission can be extensively tuned from 550 nm (1) to 675 nm (6), in which amplified spontaneous emission was readily observed for , generating a new family of proton transfer laser dyes.