The Synthesis of Benzyloxy Substituted DP-PPV and Examination of the Horner-Wadsworth-Emmons Reaction in the Synthesis of DP-PPV

In the interest of the synthesis of polymers that have the potential to possess inherent light-emitting properties (LEDs) the synthesis of a novel 1,4-bis(chloromethyl)-benzene monomer, 5-benzyloxy-1,4-dichloromethyl-2,3-diphenyl benzene 78 was carried out. Monomer 78 was polymerized via the Gilch polymerization method to yield, poly(5-benzyloxy-2,3-diphenyl phenylene vinylene) 80. Polymer 80 was characterized by TGA (5% weight loss at 267°, GPC (weight average molecular weight of 7136 Da, number average molecular weight of 6603 Da) , UV-Vis and fluorescence studies (absorbance maximum at 406 nm, emission maximum at 510 nm). The Horner-Wadsworth-Emmons variant of the Wittig was applied in the synthesis of poly(2,3-diphenyl-1,4-phenylenevinylene) (DP-PPV) 3 from 2,3-diphenylterephthalaldehyde 6 and 1,4-bis(diethoxyphosphorylmethyl)-2,3-diphenyl benzene 79, which was synthesized via the Michaelis-Arbuzov reaction. Four trials were carried out to determine an optimal method for the order of addition of the monomers and base. Of these, trial 4, which yielded polymer 3d, was found to the most optimal. Polymer 3d was characterized by TGA (5% weight loss of 319°), UV-Vis and fluorescence studies (absorbance maximum at 430 nm, emission maximum at 496 nm when excited at 416 or 424 nm)

The Synthesis of Benzyloxy Substituted DP-PPV and Examination of the Horner-Wadsworth-Emmons Reaction in the Synthesis of DP-PPV

In the interest of the synthesis of polymers that have the potential to possess inherent light-emitting properties (LEDs) the synthesis of a novel 1,4-bis(chloromethyl)-benzene monomer, 5-benzyloxy-1,4-dichloromethyl-2,3-diphenyl benzene 78 was carried out. Monomer 78 was polymerized via the Gilch polymerization method to yield, poly(5-benzyloxy-2,3-diphenyl phenylene vinylene) 80. Polymer 80 was characterized by TGA (5% weight loss at 267°, GPC (weight average molecular weight of 7136 Da, number average molecular weight of 6603 Da) , UV-Vis and fluorescence studies (absorbance maximum at 406 nm, emission maximum at 510 nm). The Horner-Wadsworth-Emmons variant of the Wittig was applied in the synthesis of poly(2,3-diphenyl-1,4-phenylenevinylene) (DP-PPV) 3 from 2,3-diphenylterephthalaldehyde 6 and 1,4-bis(diethoxyphosphorylmethyl)-2,3-diphenyl benzene 79, which was synthesized via the Michaelis-Arbuzov reaction. Four trials were carried out to determine an optimal method for the order of addition of the monomers and base. Of these, trial 4, which yielded polymer 3d, was found to the most optimal. Polymer 3d was characterized by TGA (5% weight loss of 319°), UV-Vis and fluorescence studies (absorbance maximum at 430 nm, emission maximum at 496 nm when excited at 416 or 424 nm)

Individual tree and stand-level carbon and nutrient contents across one rotation of loblolly pine plantations on a reclaimed surface mine

While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem growth, and similar data for unmined lands. At the individual tree level, we evaluated elemental contents in aboveground biomass components using tree size, age, and site index as predictor variables. At the stand-level, we then scaled individual tree C and nutrients and fit a model to determine the sensitivity of aboveground elemental contents to stand age and site index. Our data suggest that aboveground C and nutrients in loblolly pine on mined lands exceed or follow similar trends to data for unmined pine plantations derived from the literature. Diameter and height were the best predictors of individual tree stem C and nutrient contents (R ≥ 0.9473 and 0.9280, respectively) followed by stand age (R ≥ 0.8660). Foliage produced weaker relationships across all predictor variables compared to stem, though still significant (P ≤ 0.05). The model for estimating stand-level C and nutrients using stand age provided a good fit, indicating that contents aggrade over time predictably. Results of this study show successful modelling of reclaimed loblolly pine aboveground C and nutrients, and suggest elemental cycling is comparable to unmined lands, thus providing applicability of our model to related systems

Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.

The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.MAK is funded by an NIHR Research Professorship and receives funding from the Wellcome Trust, Great Ormond Street Children's Hospital Charity, and Rosetrees Trust. E.M. received funding from the Rosetrees Trust (CD-A53) and Great Ormond Street Hospital Children's Charity. K.G. received funding from Temple Street Foundation. A.M. is funded by Great Ormond Street Hospital, the National Institute for Health Research (NIHR), and Biomedical Research Centre. F.L.R. and D.G. are funded by Cambridge Biomedical Research Centre. K.C. and A.S.J. are funded by NIHR Bioresource for Rare Diseases. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (grant number WT098051). We acknowledge support from the UK Department of Health via the NIHR comprehensive Biomedical Research Centre award to Guy's and St. Thomas' National Health Service (NHS) Foundation Trust in partnership with King's College London. This research was also supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre. J.H.C. is in receipt of an NIHR Senior Investigator Award. The research team acknowledges the support of the NIHR through the Comprehensive Clinical Research Network. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, Department of Health, or Wellcome Trust. E.R.M. acknowledges support from NIHR Cambridge Biomedical Research Centre, an NIHR Senior Investigator Award, and the University of Cambridge has received salary support in respect of E.R.M. from the NHS in the East of England through the Clinical Academic Reserve. I.E.S. is supported by the National Health and Medical Research Council of Australia (Program Grant and Practitioner Fellowship)

Tunable resonant optical microcavities by self-assembled templating

Micrometer-scale optical cavities are produced by a combination of template sphere self-assembly and electrochemical growth. Transmission measurements of the tunable microcavities show sharp resonant modes with Q factors of >300 and 25-fold local enhancement of light intensity. The presence of transverse optical modes confirms the lateral confinement of photons. Calculations show that submicrometer mode volumes are feasible. The small mode volumes of these microcavities promise to lead to a wide range of applications in microlasers, atom optics, quantum information, biophotonics, and single-molecule detection

Toward a Cenozoic history of atmospheric CO2

The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO2) over long and short timescales, as well as potential drivers of evolutionary transitions. However, reconstructing CO2 beyond direct measurements requires the use of paleoproxies and herein lies the challenge, as proxies differ in their assumptions, degree of understanding, and even reconstructed values. In this study, we critically evaluated, categorized, and integrated available proxies to create a high-fidelity and transparently constructed atmospheric CO2 record spanning the past 66 million years. This newly constructed record provides clearer evidence for higher Earth system sensitivity in the past and for the role of CO2 thresholds in biological and cryosphere evolution