This study investigates the photoacidity and excited state proton transfer (ESPT) pathways of a bifunctional molecule, 6-amino-2-naphthol (6N2OH), using absorption, steady-state fluorescence, ...time-resolved fluorescence, and theoretical calculations. 6N2OH attains four different prototropic forms in the excited state (cation, neutral, anion, or zwitterion) depending on pH of the solution. Interestingly, ESPT at the OH site of the molecule can be controlled by the protonation state of the amino substituent. Conversion of the electron donating NH2 group to the electron withdrawing NH3 + group brings about a reduction of more than 7 pK a units for the deprotonation of OH in the excited state. Further, the position of the NH2 substituent on the naphthalene framework is found to play an important role in dictating the ESPT pathways of aminonaphthols. Unlike most aminonaphthol derivatives that undergo ESPT only at the OH site, akin to substituted naphthols, 6N2OH undergoes ESPT at both OH and NH3 + sites, indicating its similarity to substituted naphthols and substituted naphthylamines. ESPT at the NH3 + site resulting in cation ↔ neutral equilibrium of 6N2OH in the excited state is well-corroborated by comparative studies with another reference photoacid, 6-amino-2-methoxynaphthalene (6N2M). Correlation of the acidity constants of 6N2OH with the σp parameters according to the Hammett model reveals that while 6N2OH can be treated either as naphthol or as naphthylamine in the ground state, the structure–function correlation cannot be extrapolated directly in the excited state, thus highlighting the rich and complex photophysics of bifunctional photoacids.
Soil sorption has a significant impact on the fate and behaviour of agrochemicals in soil and water. The current study attempts to investigate the sorption desorption behaviour of Imidacloprid, a ...neonicotinoid insecticide, in three different types of black cotton soils (BC-1, BC-2, BC-3) and red soil (RS) of Southern India using batch equilibrium technique under two different temperature conditions (273/300K). The data revealed that the Freundlich model provided the best explanation for the observed adsorption isotherms. BC-2 soil had higher adsorption coefficient (K
f
) value, followed by BC-3, BC-1, and RS. Clay content, cation exchange capacity (CEC) and specific surface area (SSA) all had a positive correlation with K
f
value, indicating that they are responsible for Imidacloprid adsorption in the soil. The change in enthalpy (ΔH°) value was found to be negative in all of the investigated soils, indicating that the sorption process was spontaneous and exothermic, and that hydrogen bonding may be responsible for sorption. The low value of K
f
and organic carbon partition coefficient (K
oc
) indicates that Imidacloprid is mobile in black cotton and red soils and has potential to contaminate groundwater resources.
Electronic nematicity in Sr2RuO4 Wu, Jie; Nair, Hari P; Bollinger, Anthony T ...
Proceedings of the National Academy of Sciences - PNAS,
05/2020, Letnik:
117, Številka:
20
Journal Article
Recenzirano
Odprti dostop
We have measured the angle-resolved transverse resistivity (ARTR), a sensitive indicator of electronic anisotropy, in high-quality thin films of the unconventional superconductor Sr2RuO4 grown on ...various substrates. The ARTR signal, heralding the electronic nematicity or a large nematic susceptibility, is present and substantial already at room temperature and grows by an order of magnitude upon cooling down to 4 K. In Sr2RuO4 films deposited on tetragonal substrates the highest-conductivity direction does not coincide with any crystallographic axis. In films deposited on orthorhombic substrates it tends to align with the shorter axis; however, the magnitude of the anisotropy stays the same despite the large lattice distortion. These are strong indications of actual or incipient electronic nematicity in Sr2RuO4.
Diacetylene-containing glycolipids are a unique class of compounds that are able to self-assemble and form ordered supramolecular structures. Polymerizable diacetylene glycolipids that can function ...as low molecular weight gelators are particularly interesting molecules which can lead to stimuli-responsive smart materials. To discover efficient organogelators with built-in functionality that may be useful in sensing local environmental changes, we have synthesized a series of novel diacetylene-containing amide and urea derivatives using d-glucosamine as the starting material. Both amphiphilic and dipolar glycolipids were synthesized, and these compounds are effective gelators for several organic solvents and aqueous solutions. The resulting gels can be cross-linked under 6 W UV light to produce blue or purple polydiacetylene gels. The cross-linked gels obtained from urea derivatives are generally dark blue and exhibit blue to red color transitions upon heating. Compared to the urea derivatives, the analogous diacetylene amides produced blue to deep purple polymerized gels, depending on the structures of the gelators. The morphologies of the gels were characterized by optical microscopy and scanning electron microscopy. Typically, self-assembled fibrous networks were observed. The synthesis and characterization of these polymerizable gelators and their UV–vis absorption upon polymerization are reported.
Umbralisib (TGR-1202) is a novel next-generation inhibitor of phosphatidylinositol 3-kinase (PI3K) isoform p110δ (PI3Kδ), which is structurally distinct from other PI3Kδ inhibitors and shows improved ...isoform selectivity. Umbralisib also uniquely inhibits casein kinase-1ε, a major regulator of protein translation. The aim of this first-in-human phase 1 study was to establish the safety and preliminary activity profile of umbralisib in patients with haematological malignancies.
We did an open-label, phase 1, dose-escalation study at seven clinics in the USA. We recruited patients aged at least 18 years with relapsed or refractory chronic lymphocytic leukaemia or small lymphocytic lymphoma, B-cell and T-cell non-Hodgkin lymphoma, or Hodgkin's lymphoma, who had received one or more previous lines of therapy, with measurable and assessable disease, and adequate organ system function. Patients self-administered an umbralisib oral tablet once per day in 28-day cycles, with dose escalation done in a traditional 3 + 3 design to establish safety and determine the maximum tolerated dose. In initial cohorts, patients took umbralisib in a fasting state at a starting dose of 50 mg, increasing to 100, 200, 400, 800, 1200, and 1800 mg until the maximum tolerated dose was reached, or the maximal dose cohort was accrued without a dose-limiting toxicity. Subsequent cohorts self-administered a micronised formulation of umbralisib tablet in a fed state at an initial dose of 200 mg, increased in increments to 400, 800, 1200, and 1800 mg until the maximum tolerated dose or the maximal dose level was accrued. In August, 2014, all patients still on study were transitioned to 800 mg of the micronised formulation and dosing of the initial formulation was discontinued. The primary endpoints of the study were investigator-assessed safety in all treated patients (the safety population), the maximum tolerated dose, and the pharmacokinetics of umbralisib. Secondary endpoints included preliminary assessments of anti-cancer activity (objective responses and duration of response). Follow-up stopped for a patient once they discontinued therapy. This study has been completed and is registered with ClinicalTrials.gov, number NCT01767766.
Between Jan 17, 2013, and Jan 14, 2016, we enrolled and treated 90 patients with umbralisib. The median duration of treatment and follow-up was 4·7 cycles (IQR 2·0–14·0) or 133 days (IQR 55–335). The most common treatment-emergent adverse events irrespective of causality were diarrhoea (in 39 43% of 90 patients), nausea (38 42%), and fatigue (28 31%). The most common grade 3 or 4 adverse events were neutropenia (in 12 13% patients), anaemia (eight 9%) and thrombocytopenia (six 7%). Serious adverse events considered at least possibly related to umbralisib occurred in seven patients: pneumonia in three (3%) patients, lung infection in one (1%), febrile neutropenia in one (1%), and colitis in two (2%), one of whom also had febrile neutropenia. The maximum tolerated dose was 1200 mg of the micronised formulation, with 800 mg of this formulation selected as the recommended phase 2 dose. Both cases of colitis occurred at above the recommended phase 2 dose. 33 (37%) of the 90 patients enrolled had an objective response to treatment with umbralisib.
Umbralisib was well tolerated and showed preliminary signs of activity in patients with relapsed or refractory haematological malignancies. The safety profile of umbralisib in this phase 1 study was distinct from that of other PI3Kδ inhibitors, with fewer occurrences of autoimmune-like toxicities such as colitis. These findings warrant further evaluation of this agent in this setting.
TG Therapeutics.
BACKGROUND OSA is highly prevalent in children and usually initially treated by adenotonsillectomy. Nonsurgical alternatives for mild OSA primarily consisting of antiinflammatory approaches have ...emerged, but their efficacy has not been extensively assessed. METHODS A retrospective review of clinically and polysomnographically diagnosed patients with OSA treated between 2007 and 2012 was performed to identify otherwise healthy children ages 2 to 14 years who fulfilled the criteria for mild OSA and who were treated with a combination of intranasal corticosteroid and oral montelukast (OM) for 12 weeks (ICS + OM). A subset of children continued OM treatment for 6 to 12 months. RESULTS A total of 3,071 children were diagnosed with OSA, of whom 836 fulfilled mild OSA criteria and 752 received ICS + OM. Overall, beneficial effects occurred in > 80% of the children, with nonadherence being documented in 61 children and adenotonsillectomy being ultimately performed in 12.3%. Follow-up polysomnography in a subset of 445 patients showed normalization of sleep findings in 62%, while 17.1% showed either no improvement or worsening of their OSA. Among the latter, older children (aged > 7 years; OR, 2.3; 95% CI, 1.43-4.13; P < .001) and obese children (BMI z -score > 1.65; OR: 6.3; 95% CI, 4.23-11.18; P < .000001) were significantly more likely to be nonresponders. CONCLUSIONS A combination of ICS + OM as initial treatment of mild OSA appears to provide an effective alternative to adenotonsillectomy, particularly in younger and nonobese children. These results support implementation of multicenter randomized trials to more definitively establish the role of ICS + OM treatment in pediatric OSA.
The ceramic material Li2ZrO3 has superior thermo-physical and thermo-chemical properties and is highly compatible with other blanket materials used in nuclear reactors. Like LiAlO2, it could be used ...in the form of an annular pellet in tritium-producing burnable absorber rods (TPBARs) to produce tritium(3H) upon thermal neutron irradiation of lithium isotope (6Li). The radiation damaged pellet crystal contains vacancies, defects of its constituent elements, and several other trapping sites which hinder the 3H diffusion process and releasing behavior. In this study, we investigate the diffusion mechanisms of 3H and O3H species in Li2ZrO3 ceramic pellet in order to understand the effects on diffusion barriers and diffusion coefficients due to the presence of interstitial and substitutional Li defects, hydroxide (O–3H) vacancy defect, and of the interactions of 3H with O-vacancies in the radiation damaged Li2ZrO3 crystal. We consider several possible diffusion pathways of interstitial and substitutional 3H and its species in a defective supercell and calculate the activation energy barrier profiles. We find that the smallest activation energy barrier is 0.3 eV and corresponding diffusion coefficient at 600 K is 1.93 × 10–9 m2/s for 3H substitutional diffusion. The smallest 3H interstitial diffusion barrier and diffusion coefficient are found to be 0.34 eV and 3.25 × 10–9 m2/s. By examining several channels for diffusion, our results show the most likely diffusion mechanism of 3H migration is occurring along the c-direction by exchange of 3H within and between different Li sites. Our calculated results reveal that the smallest energy barrier for O3H diffusion is 0.75 eV which is when O3H is diffusing to the O–Li vacancy pair and the corresponding diffusion coefficient is 6.31 × 10–13 m2/s. In terms of 3H diffusion, the obtained results indicate that the performance of Li2ZrO3 could be better than γ-LiAlO2, a widely used ceramic material in TPBAR for producing 3H.
Despite remarkable progress in survival with the availability of novel agents, an overwhelming majority of patients with multiple myeloma (MM) relapse and the curability of MM remains limited. ...Genetically defined high-risk MM represents a subgroup with an aggressive disease course despite novel agents. Allogeneic hematopoietic cell transplantation (allo-SCT) is a potentially curative option in MM that has several advantages including a tumor-free graft, and the potential for sustained immune-mediated disease control. However, historically high treatment-related mortality (TRM) and conflicting reports from prospective studies in the United States and European Union have limited the utilization of this modality. Meanwhile, newer preparative regimens, planned maintenance strategies and improvements in supportive care have led to a decline in TRM and better survival in recent years. The allo-SCT platform also provides additional options of immunotherapy at relapse including donor lymphocyte infusions, immunomodulatory drug maintenance and withdrawal of immune suppression. In this article, we provide an in-depth review of literature for allo-SCT and other immunotherapy options, as well as the authors' approach to using allo-SCT in MM.
Despite the established benefits of long‐term endocrine therapy, women with hormone receptor‐positive breast cancer remain at risk for late relapse. The basis of this is multi‐factorial including ...genetic, epigenetic, and host factors. In this study we have explored the epigenetic regulation of estrogen receptor (ER)‐dependent molecular and cellular phenotype by hsa‐miR‐18a‐5p using well‐established human ER‐positive (ER+) breast cancer cell lines. miR‐18a was overexpressed in MCF7 and ZR‐75‐1 and this led to an increase in the proliferative ability of the cells and concurrently resulted in decreased expression of luminal markers and higher expression of the basal marker, cytokeratin 14. The cells became more migratory with a significant repression of E‐cadherin and activation of the Wnt noncanonical pathway. We observed an activation of the planar cell polarity (PCP) pathway with increased activation of JNK pathway and eventually change in actin dynamics. There was increased F‐actin polymerization in cells with higher expression of miR‐18a. Examination of miR‐18a expression in a set of human ER+ breast cancer specimens showed a negative correlation between miR‐18a and ESR1 transcripts as well as ER protein. Kaplan‐Meier survival analysis of the cohort stratified by tumor hsa‐miR‐18a‐5p levels produced significant differences in disease‐free survival (log rank P < .05). This observation was independently validated in the METABRIC cohort. These data provide support for a role of hsa‐miR‐18a‐5p in altering the proliferative and migratory behavior of ER+ cells and its potential utility as a prognostic marker in clinical ER+ breast cancers.
Through the manuscript, we have tried to explore the epigenetic regulation of estrogen receptor (ER) dependent molecular and cellular phenotype by hsa‐miR‐18a‐5p. High levels of miR‐18a activates the epigenetic pathway of repression of the luminal phenotype through activation of Wnt pathway.
We have carried out proteogenomic analysis of the breast cancer transcriptomic and proteomic data, available at The Clinical Proteomic Tumor Analysis Consortium resource, to identify novel peptides ...arising from alternatively spliced events as well as other noncanonical expressions. We used a pipeline that consisted of de novo transcript assembly, six frame-translated custom database, and a combination of search engines to identify novel peptides. A portfolio of 4,387 novel peptide sequences initially identified was further screened through PepQuery validation tool (Clinical Proteomic Tumor Analysis Consortium), which yielded 1,558 novel peptides. We considered the dataset of 1,558 validated through PepQuery to understand their functional and clinical significance, leaving the rest to be further verified using other validation tools and approaches. The novel peptides mapped to the known gene sequences as well as to genomic regions yet undefined for translation, 580 novel peptides mapped to known protein-coding genes, 147 to non–protein-coding genes, and 831 belonged to novel translational sequences. The novel peptides belonging to protein-coding genes represented alternatively spliced events or 5′ or 3′ extensions, whereas others represented translation from pseudogenes, long noncoding RNAs, or novel peptides originating from uncharacterized protein-coding sequences—mostly from the intronic regions of known genes. Seventy-six of the 580 protein-coding genes were associated with cancer hallmark genes, which included key oncogenes, transcription factors, kinases, and cell surface receptors. Survival association analysis of the 76 novel peptide sequences revealed 10 of them to be significant, and we present a panel of six novel peptides, whose high expression was found to be strongly associated with poor survival of patients with human epidermal growth factor receptor 2–enriched subtype. Our analysis represents a landscape of novel peptides of different types that may be expressed in breast cancer tissues, whereas their presence in full-length functional proteins needs further investigations.
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•Novel protein variants and peptides from noncoding sequences are rapidly emerging.•Mining of mass spectrometry data using proteogenomic analysis reveals such entities.•Novel peptides from coding and noncoding sequences identified in breast cancer.•Novel peptides mapped to cancer hallmark genes in breast cancer.•Panel of novel peptides with prognostic potential found for HER2-enriched subtype.
Alternative splicing of known protein-coding genes and expression of noncoding sequences of the human genome are increasingly expanding the functional diversity of proteins. These events may be specific to cell type or physiological condition of the cells and may be deregulated in cancer. Using proteogenomic analysis, we have identified novel peptides in breast cancer that arise from such events. High expression of some of them is associated with patients' survival and may be studied as prognostic indicators.
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