Результаты поиска

Photoluminescence of 1-D copper(I) cyanide chains: a theoretical description.

Solid copper(I) cyanide occurs as extended one-dimensional chains with interesting photophysical properties. To explain the observed luminescence spectroscopy of CuCN, we report a series of computational studies using short bare and potassium-capped [Cu(n)(CN)(n+1)] (-) (n = 1, 2, 3, 4, 5, and 7) chains as CuCN models. On the basis of TD-DFT calculations of these model chains, the excitation transitions in the UV spectrum are assigned as Laporte-allowed pi-pi transitions from MOs with Cu 3d(pi) and CN pi character to empty MOs with Cu 4p and CN pi* character. Transitions between the HOMO (3d(z

Insights From Twin Research: Conference at Royal Childrens Hospital, Melbourne, Australia / Twin Studies: Timing of Monozygotic Splitting and Commentary; Gestational Diabetes; ICOMBO'S Post-Partum Depression Study; Photographs of Conjoined Twins / Human Interest: Rare Quadruplets; Mistaken Identity on the Soccer Field; Prenatal Laser Surgery on Triplets; Twins Born to Prince and Princess of Monaco.

Highlights from a conference, 'Healthier Kids: Insights From Twin Research', held in Melbourne, Australia on December 5, 2014, are summarized. In addition to informative and exciting presentations and discussions of recent findings, three key themes emerged: (1) results from twin research have important implications for non-twins, (2) researchers from diverse disciplines should be encouraged to participate actively in twin research, and (3) investigators, twins and families need to work more collaboratively. Next, papers and studies concerning the biological bases of monozygotic (MZ) twinning,

Cetuximab plus FOLFOXIRI versus cetuximab plus FOLFOX as conversion regimen in RAS/BRAF wild-type patients with initially unresectable colorectal liver metastases (TRICE trial): A randomized controlled trial.

BACKGROUND: It remains unclear whether intensification of the chemotherapy backbone in tandem with an anti-EGFR can confer superior clinical outcomes in a cohort of RAS/BRAF wild-type colorectal cancer (CRC) patients with initially unresectable colorectal liver metastases (CRLM). To that end, we sought to comparatively evaluate the efficacy and safety of cetuximab plus FOLFOXIRI (triplet arm) versus cetuximab plus FOLFOX (doublet arm) as a conversion regimen (i.e., unresectable to resectable) in CRC patients with unresectable CRLM. METHODS AND FINDINGS: This open-label, randomized clinical tr

Exciplex spin-flip acceleration enables high-performance narrowband electroluminescence.

Exciplex-forming systems that harvest triplet excitons via a triplet-to-singlet spin flip (reverse intersystem crossing, RISC) enable thermally activated delayed fluorescence, providing a route to boost light emission in organic light-emitting diodes. Here, we report heavy-atom-incorporated exciplexes in which the triplet state is predominantly localized on the heavy-atom fragment, resulting in large spin-orbit coupling. Through positional isomer optimization, the RISC rate constant reaches 4.9 × 106 s-1, approximately an order of magnitude higher than in typical exciplexes. Organic light-emit

Spin-Orbit versus Hyperfine Coupling-Mediated Intersystem Crossing in a Radical Pair.

While spin-orbit coupling (SOC) is typically the dominant interaction that couples singlet and triplet states within individual chromophores, hyperfine coupling (HFC) becomes important in multichromophoric systems, particularly in relation to the radical pair mechanism. Here, we use TD-DFT to calculate the spin-orbit coupling and hyperfine coupling between the first singlet and triplet charge transfer states of the radical pair 2Pyrene- and 2N,N-dimethylaniline+. We show that, as the intermolecular donor-acceptor distance grows, SOC decays to zero (as one would expect) because singlet and trip

Towards better understanding of the photophysics of platinum(II) coordination compounds with anthracene- and pyrene-substituted 2,6-bis(thiazol-2-yl)pyridines.

The photophysical properties of platinum(ii) compounds with 4-(9-anthryl)-2,6-bis(thiazol-2-yl)pyridine (1) and 4-(1-pyrenyl)-2,6-bis(thiazol-2-yl)pyridine (2) were widely investigated. In DMSO and MeCN, the triplet emission of (1) and (2) most probably experiences the solvent-induced exciplex quenching and both complexes exhibit ligand-based fluorescence with maxima in the range of 468-570 nm. In non-coordinating dichloromethane, the emission of (1) and (2) shifts to longer wavelengths, and the lifetimes in microseconds are indicative of phosphorescence. The formation of the triplet excited s

Photodissociation of dibromobenzenes at 266 nm by the velocity imaging technique.

A velocity imaging technique combined with (2+1) resonance-enhanced multiphoton ionization (REMPI) is used to detect the primary Br((2)P(3/2)) fragment in the photodissociation of o-, m-, and p-dibromobenzene at 266 nm. The obtained translational energy distributions suggest that the Br fragments are produced via two dissociation channels. For o- and m-dibromobenzene, the slow channel that yields an anisotropy parameter close to zero is proposed to stem from excitation of the lowest excited singlet (pi,pi*) state followed by predissociation along a repulsive triplet (n,sigma*) state localized

Energy Transfer Catalysis Enabled by Multichannel Through-Space Charge Transfer TADF Photosensitizers: [2 + 2] Photocycloaddition to Cyclobutane-Fused Phosphindole 3-Oxides.

Triplet energy transfer (TEnT) photocatalysis has emerged as a powerful tool for enabling mild and selective bond-forming reactions. However, its generality remains limited by the intrinsic trade-offs in existing photosensitizers (PSs). Noble metal (e.g., Ir, Ru) complexes offer high efficiency yet suffer from cost and sustainability concerns, while organic carbonyl sensitizers suffer from weak visible-light absorption and short-lived triplet states. Herein, we report heavy-atom-free organic PSs featuring a multi-channel through-space charge transfer (TSCT) architecture within a thermally acti

Alliance A061202: ixazomib, pomalidomide, and dexamethasone for patients with lenalidomide-refractory MM in first relapse.

AbstractOptimal therapy for the growing number of patients with lenalidomide (LEN)-refractory multiple myeloma in their first relapse remains poorly defined. We therefore undertook a randomized phase 2 study to evaluate the efficacy and safety of combining the oral proteasome inhibitor ixazomib (IXA) with pomalidomide (POM) and dexamethasone (DEX) in this patient population. The overall response rate (ORR) for POM-DEX was 43.6%, and for IXA-POM-DEX, it was 63.2%. The depth of response, measured by the attainment of at least a very good partial response, favored triplet therapy over doublet the

Совпадение в полном тексте источника
… Given the fact that POM-DEX is no longer considered an optimal standard of care for relapsed patients, a phase 3 study would need to incorporate a modern triplet regimen as the control arm. … Our findings align with the results of other studies that evaluated POM-proteasome inhibitor triplets in this patient population. …

A detailed analysis of the spin-crossover reaction of H2S binding to heme and the six-coordinated FeP(Im)-HS- porphyrin complex.

The potential energy surfaces of the H2S binding to iron-porphyrin (FeP) with the imidazole (Im) ligand via intersystem crossings are investigated by using density functional theory. The minimum energy intersystem crossing point (MEISCP) between the quintet and triplet states (MEISCPTQ) for the Fe(II)P(Im)-H2S complex is located at a Fe-S distance of 3.39 Å with only 1.1 kcal/mol above the quintet state minimum. The second spin-crossover point, where a change from the triplet to the singlet state occurs, comes at a much shorter Fe-S distance of 2.79 Å, and the MEISCPST is located at 3.7 kcal/m

Study protocol for a double-blind, comparative, randomised Japanese trial of triplet standard antiemetic therapies with or without 5 mg olanzapine to prevent chemotherapy-induced nausea and vomiting for patients with breast cancer treated with an anthracycline/cyclophosphamide regimen (JTOP-B).

INTRODUCTION: Triple antiemetic therapy with neurokinin-1 receptor antagonist, 5-hydroxytryptamine type 3 receptor antagonist, and dexamethasone has been widely recommended for high emetogenic chemotherapeutic (HEC) agents and regimens, including anthracycline combined with cyclophosphamide (AC). The addition of olanzapine (OLZ) 5 mg or 10 mg to the recommended triple antiemetic therapy has demonstrated superiority in antiemetic efficacy compared with the standard triplet therapy for a cisplatin-based HEC regimen. Although OLZ plus the triple antiemetic treatment may also be effective for pati

Poorly differentiated neuroendocrine rectal carcinoma with uncommon immune-histochemical features and clinical presentation with a subcutaneous metastasis, treated with first line intensive triplet chemotherapy plus bevacizumab FIr-B/FOx regimen: an experience of multidisciplinary management in clinical practice.

BACKGROUND: Neuroendocrine tumors (NETs) are heterogeneous, widely distributed tumors arising from neuroendocrine cells. Gastrointestinal (GI)-NETs are the most common and NETs of the rectum represent 15, 2% of gastrointestinal malignancies. Poorly differentiated neuroendocrine carcinomas of the GI tract are uncommon. We report a rare case of poorly differentiated locally advanced rectal neuroendocrine carcinoma with nodal and a subcutaneous metastasis, with a cytoplasmic staining positive for Synaptophysin and Thyroid Transcription Factor-1. CASE PRESENTATION: A 72-year-old male presented to

Hybrid Molecule-Nanocrystal Photon Upconversion Across the Visible and Near-Infrared.

The ability to upconvert two low energy photons into one high energy photon has potential applications in solar energy, biological imaging, and data storage. In this Letter, CdSe and PbSe semiconductor nanocrystals are combined with molecular emitters (diphenylanthracene and rubrene) to upconvert photons in both the visible and the near-infrared spectral regions. Absorption of low energy photons by the nanocrystals is followed by energy transfer to the molecular triplet states, which then undergo triplet-triplet annihilation to create high energy singlet states that emit upconverted light. By

DNA extrusion size determines pathway choice during CAG repeat expansion.

DNA triplet repeat expansion is the mutational cause of neurodegenerative disorders such as Huntington's disease, myotonic dystrophy type 1, and fragile-X related disorders. There is a general consensus that recognition of extrahelical extrusions or hairpin-loop structures (formed by strand slippage) by the DNA mismatch repair protein MutSβ leads to repeat expansion by a mutagenic repair process. By contrast, the FAN1 nuclease prevents triplet repeat expansion, the molecular basis of which was explained by our recent finding that FAN1 nuclease cleaves and initiates removal of extrahelical extr

Charge-Transfer Exciton Formation by Designing Donor-Acceptor Motifs for Polymeric-Semiconductor-Based Photocatalytic Singlet Oxygen Production.

Metal-free polymeric semiconductors exhibit substantial potential in attaining photocatalytic solar energy conversion via exciton-based energy transfer, whereas their inefficient triplet-exciton yields caused by faint spin-orbit coupling set limits to the relevant applications. Here, we present an alternative pathway for harvesting long-lived triplet excitons in polymeric photocatalysts, where a charge-transfer exciton (CTE), rather than an intrinsic Frenkel exciton, hosted in donor-acceptor motifs is employed for triggering energy-transfer-mediated photocatalysis. By taking polymeric carbon n

Redox control of photoinduced electron transfer in axial terpyridoxy porphyrin complexes.

The photophysical properties of axial-bonding types (terpyridoxy)aluminum(III) porphyrin (Al(PTP)), bis(terpyridoxy)tin(IV) porphyrin (Sn(PTP) 2), and bis(terpyridoxy)phosphorus(V) porphyrin ([P(PTP) 2] (+)) are reported. Compared with their hydroxy analogues, the fluorescence quantum yields and singlet-state lifetimes were found to be lower for Sn(PTP) 2 and [P(PTP) 2] (+), whereas no difference was observed for Al(PTP). At low temperature, all of the compounds show spin-polarized transient electron paramagnetic resonance (TREPR) spectra that are assigned to the lowest excited triplet state o

Significant reduction of twins with single embryo transfer in IVF.

Multiple pregnancies in assisted reproduction can be regarded as iatrogenic and avoidable, given that the phenomenon is related to the numbe … s, you get only one embryo at a time'. Multiple pregnancy rates are well below 10% and there are no triplets. In conclusion, triplet rates can be reduced to zero and twin rates to below 10% by eSET. The cumulative pregnancy rate per oocyte recovery is not reduced, including replacement of frozen- thawed embryos.

Confinement enhanced phosphorescent electrochemiluminescence of copper iodide cluster complex for imaging detection of organophosphorus pesticide.

Owing to the spin statistics of electrogenerated excitons, conventional fluorescent ECL materials fail to utilize 75% of the triplet excitons. To improve the utilization efficiency of triplet excitons, this work proposed a strategy for the design of phosphorescent ECL material based on the synergistic effect of heavy-atom iodine enhanced spin-orbit coupling (SOC) and rigid molecular environment. A copper-iodide cluster complex Cu4I6(pr-ted)2 was successfully synthesized using 1-propyl-1,4-diazabicyclo[2.2.2]octanium (pr-ted) as the organic cation and polyvinylpyrrolidone for chain entanglement

Current and future role of carfilzomib-based quadruplet combinations as therapy for newly diagnosed multiple myeloma.

The treatment of newly diagnosed multiple myeloma (NDMM) has advanced rapidly in recent years, with the standard of care (SOC) now including not only triplet combinations of proteasome inhibitors (PIs), immunomodulatory agents, and steroids but also quadruplet combinations that add the anti-CD38 monoclonal antibodies isatuximab (Isa) or daratumumab (D) to a triplet backbone. In addition to the widely used bortezomib-lenalidomide-dexamethasone (VRd) combination, an alternative triplet option that can be considered is the combination of the second-generation PI carfilzomib (K) with lenalidomide-

The three kingdoms-Photoinduced electron transfer cascades controlled by electronic couplings.

Excited states are the key species in photocatalysis, while the critical parameters that govern their applications are (i) excitation energy, (ii) accessibility, and (iii) lifetime. However, in molecular transition metal-based photosensitizers, there is a design tension between the creation of long-lived excited (triplet), e.g., metal-to-ligand charge transfer (3MLCT) states and the population of such states. Long-lived triplet states have low spin-orbit coupling (SOC) and hence their population is low. Thus, a long-lived triplet state can be populated but inefficiently. If the SOC is increase