Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
1.
Syst Biol ; 72(4): 885-911, 2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-37074804

RESUMO

The biota of Sulawesi is noted for its high degree of endemism and for its substantial levels of in situ biological diversification. While the island's long period of isolation and dynamic tectonic history have been implicated as drivers of the regional diversification, this has rarely been tested in the context of an explicit geological framework. Here, we provide a tectonically informed biogeographical framework that we use to explore the diversification history of Sulawesi flying lizards (the Draco lineatus Group), a radiation that is endemic to Sulawesi and its surrounding islands. We employ a framework for inferring cryptic speciation that involves phylogeographic and genetic clustering analyses as a means of identifying potential species followed by population demographic assessment of divergence-timing and rates of bi-directional migration as means of confirming lineage independence (and thus species status). Using this approach, phylogenetic and population genetic analyses of mitochondrial sequence data obtained for 613 samples, a 50-SNP data set for 370 samples, and a 1249-locus exon-capture data set for 106 samples indicate that the current taxonomy substantially understates the true number of Sulawesi Draco species, that both cryptic and arrested speciations have taken place, and that ancient hybridization confounds phylogenetic analyses that do not explicitly account for reticulation. The Draco lineatus Group appears to comprise 15 species-9 on Sulawesi proper and 6 on peripheral islands. The common ancestor of this group colonized Sulawesi ~11 Ma when proto-Sulawesi was likely composed of two ancestral islands, and began to radiate ~6 Ma as new islands formed and were colonized via overwater dispersal. The enlargement and amalgamation of many of these proto-islands into modern Sulawesi, especially during the past 3 Ma, set in motion dynamic species interactions as once-isolated lineages came into secondary contact, some of which resulted in lineage merger, and others surviving to the present. [Genomics; Indonesia; introgression; mitochondria; phylogenetics; phylogeography; population genetics; reptiles.].


Assuntos
Lagartos , Animais , Filogenia , Indonésia , Lagartos/genética , Filogeografia , Genética Populacional , Especiação Genética
2.
Anal Chem ; 95(23): 9123-9129, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37261935

RESUMO

In nuclear forensic analyses, measurements of actinide elements in a sample can assist with identifying interdicted or unknown materials. While these radiochemical signatures have been extensively investigated in uranium materials, less is known about bulk neptunium samples. This paper describes the measurement of trace actinide concentrations and isotopic profiles in a 237Np oxide sample. Uranium, plutonium, americium, and curium concentrations and isotopic profiles in the sample were determined and deemed potentially useful for distinguishing different sources of 237Np. Several different potential radiochronometry systems were also investigated; discordant results indicate that the Np sample was never completely purified of other actinide elements, or that subsequent contamination of the sample occurred. Few prior studies of neptunium materials have been reported, and these data suggest that trace actinide constituents could provide unique signatures to identify material out of regulatory control.

3.
Mol Phylogenet Evol ; 186: 107853, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37327831

RESUMO

Bent-toed Geckos, genus Cyrtodactylus, are one of the most diverse terrestrial vertebrate groups, and their range extends from South Asia into Australo-Papua and adjacent Pacific islands. Given the generally high faunal endemism on Wallacean islands, it is rather paradoxical that the diversity in these geckos appears to be so low (21 species in Wallacea, 15 in the Philippines) compared with continental shelf assemblages (>300 species on Sunda + Sahul Shelves + adjacent islands). To determine whether this shortfall was real or an artifact of historical undersampling, we analyzed mitochondrial DNA sequences of hundreds of southern Wallacean samples (Lesser Sundas + southern Maluku). After screening to guide sample selection for target capture data collection, we obtained a 1150-locus genomic dataset (1,476,505 bp) for 119 samples of southern Wallacean and closely related lineages. The results suggest that species diversity of Cyrtodactylus in southern Wallacea is vastly underestimated, with phylogenomic and clustering analyses suggesting as many as 25 candidate species, in contrast to the 8 currently described. Gene exchange between adjacent candidate species is absent or minimal across the archipelago with only one case of > 0.5 migrants per generation. Biogeographical analysis suggests that the hitherto unrecognized diversity is the result of at least three independent dispersals from Sulawesi or its offshore islands into southern Wallacea between 6 and 14 Ma, with one invasion producing small-bodied geckos and the other two or three producing larger-bodied geckos. The smaller-bodied laevigatus group appears to be able to coexist with members of either larger-bodied clade, but we have yet to find members of the two larger-bodied clades occurring in sympatry, suggesting that ecological partitioning or competitive exclusion may be shaping individual island assemblages.


Assuntos
Besouros , Lagartos , Animais , Filogenia , Indonésia , Filipinas , Lagartos/genética
4.
Syst Biol ; 71(1): 221-241, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34117769

RESUMO

The Lesser Sunda Archipelago offers exceptional potential as a model system for studying the dynamics of dispersal-driven diversification. The geographic proximity of the islands suggests the possibility for successful dispersal, but this is countered by the permanence of the marine barriers and extreme intervening currents that are expected to hinder gene flow. Phylogenetic and species delimitation analyses of flying lizards (genus Draco) using single mitochondrial genes, complete mitochondrial genomes, and exome-capture data sets identified 9-11 deeply divergent lineages including single-island endemics, lineages that span multiple islands, and parapatrically distributed nonsister lineages on the larger islands. Population clustering and PCA confirmed these genetic boundaries with isolation-by-distance playing a role in some islands or island sets. While gdi estimates place most candidate species comparisons in the ambiguous zone, migration estimates suggest 9 or 10 species exist with nuclear introgression detected across some intra-island contact zones. Initial entry of Draco into the archipelago occurred at 5.5-7.5 Ma, with most inter-island colonization events having occurred between 1-3 Ma. Biogeographical model testing favors scenarios integrating geographic distance and historical island connectivity, including an initial stepping-stone dispersal process from the Greater Sunda Shelf through the Sunda Arc as far eastward as Lembata Island. However, rather than reaching the adjacent island of Pantar by dispersing over the 15-km wide Alor Strait, Draco ultimately reached Pantar (and much of the rest of the archipelago) by way of a circuitous route involving at least five overwater dispersal events. These findings suggest that historical geological and oceanographic conditions heavily influenced dispersal pathways and gene flow, which in turn drove species formation and shaped species boundaries. [Biogeography; genomics, Indonesia; lizards; phylogeography; reptiles].


Assuntos
Fluxo Gênico , Lagartos , Animais , Indonésia , Lagartos/genética , Filogenia , Filogeografia
5.
J Am Chem Soc ; 143(12): 4817-4823, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33725443

RESUMO

A facile one-pot strategy for 13CN and 14CN exchange with aryl, heteroaryl, and alkenyl nitriles using a Ni phosphine catalyst and BPh3 is described. This late-stage carbon isotope exchange (CIE) strategy employs labeled Zn(CN)2 to facilitate enrichment using the nonlabeled parent compound as the starting material, eliminating de novo synthesis for precursor development. A broad substrate scope encompassing multiple pharmaceuticals is disclosed, including the preparation of [14C] belzutifan to illustrate the exceptional functional group tolerance and utility of this labeling approach. Preliminary experimental and computational studies suggest the Lewis acid BPh3 is not critical for the oxidative addition step and instead plays a role in facilitating CN exchange on Ni. This CIE method dramatically reduces the synthetic steps and radioactive waste involved in preparation of 14C labeled tracers for clinical development.

6.
Chemistry ; 26(19): 4251-4255, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32003092

RESUMO

A late-stage 18 O labeling approach of sulfonamides that employs the corresponding unlabeled molecule as the starting material was developed. Upon deamination of the sulfonamide, a sulfinate intermediate was isotopically enriched using eco-friendly reagents H2 18 O and 15 NH3 (aq) to afford a M+5 isotopologue of the parent compound. This degradation-reconstruction approach afforded isolated yields of up to 96 % for the stable isotope labeled (SIL) sulfonamides, and was compatible with multiple marketed therapeutics, including celecoxib, on a gram scale. The SIL products also exhibited no 18 O/16 O back exchange under extreme conditions, further validating the utility of this green strategy for drug labeling for both in vitro and in vivo use. This procedure was also adapted to include pharmaceutically relevant methyl sulfones by using 13 CH3 , affording M+5 isotopic enrichment, thereby illustrating the broad utility of this methodology.

7.
Ann Clin Psychiatry ; 32(1): 27-32, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31990966

RESUMO

BACKGROUND: Our goal was to determine the risk factors that most correlated with mood disorder diagnoses in children in a low-income, urban community. METHODS: We conducted a retrospective chart review of 174 patients age 6 to 18 who were seen between November 2016 and July 2017 at the University Hospital Psychiatric Pediatric Emergency Services in Newark, New Jersey, United States. RESULTS: Bivariate and multivariate analyses revealed that increasing age, female sex, exposure to trauma, and family history of psychiatric illness were significantly associated with mood disorders in our sample. CONCLUSIONS: The correlation of mood disorders with trauma and family psychiatric history is of particular significance in our sample. In low-income cities with high crime rates and a lack of positive influences, children often have difficulty obtaining the skills to cope with trauma in a healthy manner. Also, the paucity of resources in these communities prevents family members from getting the mental health treatment that they need, further inhibiting children in these families from developing healthy habits. Mental health treatment must be targeted towards entire families and not just in children with mood disorders in order to most effectively improve the mental health outcomes of those who grow up in these communities.


Assuntos
Filho de Pais com Deficiência/estatística & dados numéricos , Família , Transtornos do Humor/epidemiologia , Pobreza/estatística & dados numéricos , Trauma Psicológico/epidemiologia , População Urbana/estatística & dados numéricos , Adolescente , Fatores Etários , Criança , Feminino , Humanos , Masculino , New Jersey/epidemiologia , Estudos Retrospectivos , Fatores Sexuais
8.
J Proteome Res ; 18(5): 2206-2220, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-30958009

RESUMO

The genus Trimeresurus comprises a group of venomous pitvipers endemic to Southeast Asia and the Pacific Islands. Of these, Trimeresurus insularis, the White-lipped Island Pitviper, is a nocturnal, arboreal species that occurs on nearly every major island of the Lesser Sunda archipelago. In the current study, venom phenotypic characteristics of T. insularis sampled from eight Lesser Sunda Islands (Flores, Lembata, Lombok, Pantar, Sumba, Sumbawa, Timor, and Wetar) were evaluated via SDS-PAGE, enzymatic activity assays, fibrinogenolytic assays, gelatin zymography, and RP-HPLC, and the Sumbawa sample was characterized by venomic analysis. For additional comparative analyses, venoms were also examined from several species in the Trimeresurus complex, including T. borneensis, T. gramineus, T. puniceus, T. purpureomaculatus, T. stejnegeri, and Protobothrops flavoviridis. Despite the geographical isolation, T. insularis venoms from all eight islands demonstrated remarkable similarities in gel electrophoretic profiles and RP-HPLC patterns, and all populations had protein bands in the mass ranges of phosphodiesterases (PDE), l-amino acid oxidases (LAAO), P-III snake venom metalloproteinases (SVMP), serine proteases, cysteine-rich secretory proteins (CRISP), phospholipases A2 (PLA2), and C-type lectins. An exception was observed in the Lombok sample, which lacked protein bands in the mass range of serine protease and CRISP. Venomic analysis of the Sumbawa venom also identified these protein families, in addition to several proteins of lesser abundance (<1%), including glutaminyl cyclase, aminopeptidase, PLA2 inhibitor, phospholipase B, cobra venom factor, 5'-nucleotidase, vascular endothelial growth factor, and hyaluronidase. All T. insularis venoms exhibited similarities in thrombin-like and PDE activities, while significant differences were observed for LAAO, SVMP, and kallikrein-like activities, though these differences were only observed for a few islands. Slight but noticeable differences were also observed with fibrinogen and gelatin digestion activities. Trimeresurus insularis venoms exhibited overall similarity to the other Trimeresurus complex species examined, with the exception of P. flavoviridis venom, which showed the greatest overall differentiation. Western blot analysis revealed that all major T. insularis venom proteins were recognized by Green Pitviper ( T. albolabris) antivenom, and reactivity was also seen with most venom proteins of the other Trimeresurus species, but incomplete antivenom-venom recognition was observed against P. flavoviridis venom proteins. These results demonstrate significant conservation in the venom composition of T. insularis across the Lesser Sunda archipelago relative to the other Trimeresurus species examined.


Assuntos
Venenos de Crotalídeos/química , L-Aminoácido Oxidase/isolamento & purificação , Metaloproteases/isolamento & purificação , Diester Fosfórico Hidrolases/isolamento & purificação , Serina Proteases/isolamento & purificação , Trimeresurus/metabolismo , Animais , Antivenenos/farmacologia , Sequência Conservada , Venenos de Crotalídeos/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Fibrinogênio/química , Gelatina/química , Expressão Gênica , Indonésia , Ilhas , L-Aminoácido Oxidase/antagonistas & inibidores , L-Aminoácido Oxidase/genética , L-Aminoácido Oxidase/metabolismo , Lectinas Tipo C/antagonistas & inibidores , Lectinas Tipo C/genética , Lectinas Tipo C/isolamento & purificação , Lectinas Tipo C/metabolismo , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/isolamento & purificação , Glicoproteínas de Membrana/metabolismo , Metaloproteases/antagonistas & inibidores , Metaloproteases/genética , Metaloproteases/metabolismo , Fenótipo , Fosfolipases A2/genética , Fosfolipases A2/isolamento & purificação , Fosfolipases A2/metabolismo , Diester Fosfórico Hidrolases/genética , Diester Fosfórico Hidrolases/metabolismo , Filogenia , Proteólise , Serina Proteases/genética , Serina Proteases/metabolismo , Trimeresurus/genética
9.
Proc Biol Sci ; 286(1904): 20182575, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31161911

RESUMO

The importance of long-distance dispersal (LDD) in shaping geographical distributions has been debated since the nineteenth century. In terrestrial vertebrates, LDD events across large water bodies are considered highly improbable, but organismal traits affecting dispersal capacity are generally not taken into account. Here, we focus on a recent lizard radiation and combine a summary-coalescent species tree based on 1225 exons with a probabilistic model that links dispersal capacity to an evolving trait, to investigate whether ecological specialization has influenced the probability of trans-oceanic dispersal. Cryptoblepharus species that occur in coastal habitats have on average dispersed 13 to 14 times more frequently than non-coastal species and coastal specialization has, therefore, led to an extraordinarily widespread distribution that includes multiple continents and distant island archipelagoes. Furthermore, their presence across the Pacific substantially predates the age of human colonization and we can explicitly reject the possibility that these patterns are solely shaped by human-mediated dispersal. Overall, by combining new analytical methods with a comprehensive phylogenomic dataset, we use a quantitative framework to show how coastal specialization can influence dispersal capacity and eventually shape geographical distributions at a macroevolutionary scale.


Assuntos
Distribuição Animal , Lagartos/fisiologia , Animais , Evolução Biológica , Ecossistema , Lagartos/classificação , Lagartos/genética , Oceanos e Mares , Filogenia , Filogeografia , Dinâmica Populacional
10.
Inorg Chem ; 58(6): 3559-3563, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30807118

RESUMO

Separation of U, Np, and Pu from used nuclear fuel (UNF) would result in lower long-term radiotoxicity, alleviating constraints on the storage and handling of the material. The complexity of UNF requires several industrial-scale processes with multiple waste streams. A one-step solution to the group removal of the elements, U-Pu, is desirable. Here we present a possible solution to group actinide separation utilizing the unique dioxy conformation of An(V/VI) cations and demonstrate the ability of a tetradentate lipophilic Schiff base ligand (L) to yield isostructural complexes of the general formula [(AnVIO2)(L)(CH3CN)] (where An = U, Np, or Pu). Extraction of An(VI) with the ligand follows the order U > Pu > Np, likely reflecting the decreased stability of the hexavalent actinide across the series. While the results indicate a promising path toward a one-step process, further improvement in the ligand stability and control of the redox chemistry is required.

11.
Bioorg Chem ; 83: 242-249, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30390553

RESUMO

Poly(ADP-ribose)polymerase-1 inhibitor (PARPi) AZD2461 was designed to be a weak P-glycoprotein (P-gp) analogue of FDA approved olaparib. With this chemical property in mind, we utilized the AZD2461 ligand architecture to develop a CNS penetrant and PARP-1 selective imaging probe, in order to investigate PARP-1 mediated neuroinflammation and neurodegenerative diseases, such as Alzheimer's and Parkinson's. Our work led to the identification of several high-affinity PARPi, including AZD2461 congener 9e (PARP-1 IC50 = 3.9 ±â€¯1.2 nM), which was further evaluated as a potential 18F-PET brain imaging probe. However, despite the similar molecular scaffolds of 9e and AZD2461, our studies revealed non-appreciable brain-uptake of [18F]9e in non-human primates, suggesting AZD2461 to be non-CNS penetrant.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Ftalazinas/farmacologia , Piperidinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/agonistas , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Radioisótopos de Flúor/química , Humanos , Macaca mulatta , Masculino , Camundongos Endogâmicos BALB C , Ftalazinas/síntese química , Piperidinas/síntese química
12.
Glob Chang Biol ; 23(12): 5029-5031, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28833907

RESUMO

(a) A map of Wallacea showing islands invaded by Duttaphrynus melanostictus in red, islands inhabited by Varanus komodoensis in blue, and localities of genetic samples in yellow points. (b) A D. melanostictus from Lombok Island. (c) Environmental niche model for the Sunda Islands clade of D. melanostictus projected into Wallacea. Green color indicates very high suitability, yellow color indicates high suitability, and orange color indicates moderate suitability.


Assuntos
Distribuição Animal , Biodiversidade , Bufonidae/fisiologia , Espécies Introduzidas , Animais , Lagartos/fisiologia , Ilhas do Pacífico
13.
Tetrahedron Lett ; 58(5): 466-469, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31762498

RESUMO

Application of Buchwald-Hartwig catalysis for development of biologically relevant arylspirodiamine compounds is reported. This synthetic methodology requires no inert atmosphere and affords yields up to 93% in just 20 min. Linear and sterically hindered angular spirodiamines in salt and free-base form are coupled with electron-rich and -withdrawing aryl chlorides, demonstrating a broad scope and applicability of this protocol.

14.
J Man Manip Ther ; 25(2): 74-82, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28559666

RESUMO

STUDY DESIGN: Online survey study. OBJECTIVE: To determine physical therapists' utilization of thrust joint manipulation (TJM) and their comfort level in using TJM between the cervical, thoracic, and lumbar regions of the spine. We hypothesized that physical therapists who use TJM would report regular use and comfort providing it to the thoracic and lumbar spines, but not so much for the cervical spine. BACKGROUND: Recent surveys of first professional physical therapy degree programs have found that TJM to the cervical spine is not taught to the same degree as to the thoracic and lumbar spines. METHODS: We developed a survey to capture the required information and had a Delphi panel of 15 expert orthopedic physical therapists review it and provide constructive feedback. A revised version of the survey was sent to the same Delphi panel and consensus was obtained on the final survey instrument. The revised survey was made available to any licensed physical therapists in the U.S.A. using an online survey system, from October 2014 through June 2015. RESULTS: Of 1014 responses collected, 1000 completed surveys were included for analysis. There were 478 (48%) males; the mean age of respondents was 39.7 ± 10.81 years (range 24-92); and mean years of clinical experience was 13.6 ± 10.62. A majority of respondents felt that TJM was safe and effective when applied to lumbar (90.5%) and thoracic (91.1%) spines; however, a smaller percentage (68.9%) felt that about the cervical spine. More therapists reported they would perform additional screening prior to providing TJM to the cervical spine than they would for the lumbar and thoracic spines. Therapists agreed they were less likely to provide and feel comfortable with TJM in the cervical spine compared to the thoracic and lumbar spines. Finally, therapists who are male; practice in orthopedic spine setting; are aware of manipulation clinical prediction rules; and have manual therapy certification, are more likely to use TJM and be comfortable with it in all three regions. CONCLUSION: Results indicate that respondents do not believe TJM for the cervical spine to be as safe and efficacious as that for the lumbar and thoracic spines. Further, they are more likely to perform additional screening, abstain from and do not feel comfortable performing TJM for the cervical spine. CLINICAL RELEVANCE: Our research reveals there is a discrepancy between utilization of TJM at different spinal levels. This research provides an opportunity to address variability in clinical practice among physical therapists utilizing TJM.

15.
J Acoust Soc Am ; 140(3): EL269, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27914387

RESUMO

Acoustic transmission loss measurements from the calibration operations (CALOPS) experiment for the Shallow Water Array Performance (SWAP) program included horizontally refracted returns that were as much as 30° away from the true bearing between source and receiver. In many cases, the in-shore refracted path was 20 dB stronger than the true bearing path. In this study CALOPS transmission loss measurements at 415 Hz are compared to predictions from a three-dimensional Gaussian ray bundling model. The geoacoustic model that provides good model-data comparison is consistent with the geologic and sediment core data collected at the location but differs slightly from the bottom model used at lower frequencies (206 and 52.5 Hz) in a previous study.

16.
BMC Evol Biol ; 15: 241, 2015 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-26537350

RESUMO

BACKGROUND: Phylogeography is an important tool that can be used to reveal cryptic biodiversity and to better understand the processes that promote lineage diversification. We studied the phylogeographic history of the Arboreal Salamander (Aneides lugubris), a wide-ranging species endemic to the California floristic province. We used multi-locus data to reconstruct the evolutionary history of A. lugubris and to discover the geographic location of major genetic breaks within the species. We also used species distribution modeling and comparative phylogeography to better understand the environmental factors that have shaped the genetic history of A. lugubris. RESULTS: We found six major mitochondrial clades in A. lugubris. Nuclear loci supported the existence of at least three genetically distinct groups, corresponding to populations north of the San Francisco Bay and in the Sierra Nevada, in the Santa Cruz Mountains, and in the central coast and southern California. All of the genetic breaks in mitochondrial and nuclear loci corresponded to regions where historical barriers to dispersal have been observed in other species. Geologic or water barriers likely were the most important factors restricting gene flow among clades. Climatic unsuitability during glacial maximum may have contributed to the isolation of the mitochondrial clades in the central coast and southern California. A projection of our species distribution model to a future scenario with a moderate amount of climate change suggests that most of the range of A. lugubris will remain climatically suitable, but climatic conditions in the Sierra Nevada and low elevation areas in Southern California are likely to deteriorate. CONCLUSIONS: Aneides lugubris contains substantial cryptic genetic diversity as a result of historical isolation of populations. At least two (and perhaps three) evolutionarily significant units in A. lugubris merit protection; all six mitochondrial clades should be considered as management units within the species.


Assuntos
Urodelos/classificação , Urodelos/genética , Animais , Biodiversidade , Evolução Biológica , California , Mudança Climática , DNA Mitocondrial/genética , Fluxo Gênico , Variação Genética , Geologia , Filogeografia
17.
J Am Chem Soc ; 137(30): 9583-6, 2015 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-26200434

RESUMO

The discovery that imido analogs of actinyl dioxo cations can be extended beyond uranium into the transuranic elements is presented. Synthesis of the Np(V) complex, Np(NDipp)2((t)Bu2bipy)2Cl (1), is achieved through treatment of a Np(IV) precursor with a bipyridine coligand and lithium-amide reagent. Complex 1 has been structurally characterized, analyzed by (1)H NMR and UV-vis-NIR spectroscopies, and the electronic structure evaluated by DFT calculations.

18.
Hum Mol Genet ; 22(17): 3415-24, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23656793

RESUMO

The loss of functional Survival Motor Neuron (SMN) protein due to mutations or deletion in the SMN1 gene causes autosomal recessive neurodegenerative spinal muscle atrophy (SMA). A potential treatment strategy for SMA is to upregulate the amount of SMN protein originating from the highly homologous SMN2 gene, compensating in part for the absence of the functional SMN1 gene. We have previously shown that in vitro activation of the p38 pathway stabilizes and increases SMN mRNA levels leading to increased SMN protein levels. In this report, we explore the impact of the p38 activating, FDA-approved, blood brain barrier permeating compound celecoxib on SMN levels in vitro and in a mouse model of SMA. We demonstrate a significant induction of SMN protein levels in human and mouse neuronal cells upon treatment with celecoxib. We show that activation of the p38 pathway by low doses celecoxib increases SMN protein in a HuR protein-dependent manner. Furthermore, celecoxib treatment induces SMN expression in brain and spinal cord samples of wild-type mice in vivo. Critically, celecoxib treatment increased SMN levels, improved motor function and enhanced survival in a severe SMA mouse model. Our results identify low dose celecoxib as a potential new member of the SMA therapeutic armamentarium.


Assuntos
Encéfalo/efeitos dos fármacos , Pirazóis/farmacologia , Medula Espinal/efeitos dos fármacos , Atrofias Musculares Espinais da Infância/metabolismo , Sulfonamidas/farmacologia , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Proteína 2 de Sobrevivência do Neurônio Motor/metabolismo , Adolescente , Animais , Encéfalo/metabolismo , Celecoxib , Células Cultivadas , Criança , Pré-Escolar , Modelos Animais de Doenças , Proteínas ELAV/metabolismo , Regulação da Expressão Gênica , Humanos , Lactente , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Pirazóis/uso terapêutico , Medula Espinal/metabolismo , Atrofias Musculares Espinais da Infância/tratamento farmacológico , Atrofias Musculares Espinais da Infância/genética , Atrofias Musculares Espinais da Infância/fisiopatologia , Sulfonamidas/uso terapêutico , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 2 de Sobrevivência do Neurônio Motor/genética
19.
Opt Lett ; 40(6): 930-3, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25768149

RESUMO

A monolithic diamond Raman laser is reported. It utilizes a 13-mm radius of curvature lens etched onto the diamond surface and dielectric mirror coatings to form a stable resonator. The performance is compared to that of a monolithic diamond Raman laser operating in a plane-plane cavity. On pumping with a compact Q-switched laser at 532 nm (16 µJ pulse energy; 1.5 ns pulse duration; 10 kHz repetition-rate; M2<1.5), laser action was observed at the first, second, and third Stokes wavelengths (573 nm, 620 nm and 676 nm, respectively) in both cases. For the microlens cavity, a conversion efficiency of 84% was achieved from the pump to the total Raman output power, with a slope efficiency of 88%. This compares to a conversion efficiency of 59% and a slope efficiency of 74% for the plane-plane case. Total Raman output powers of 134 and 96 mW were achieved for the microlens and plane-plane cavities, respectively.

20.
Inorg Chem ; 54(9): 4192-9, 2015 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-25901900

RESUMO

A-type tri-lacunary heteropolyoxotungstate anions (e.g., [PW9O34](9-), [AsW9O34](9-), [SiW9O34](10-), and [GeW9O34](10-)) are multidentate oxygen donor ligands that readily form sandwich complexes with actinyl cations ({UO2}(2+), {NpO2}(+), {NpO2}(2+), and {PuO2}(2+)) in near-neutral/slightly alkaline aqueous solutions. Two or three actinyl cations are sandwiched between two tri-lacunary anions, with additional cations (Na(+), K(+), or NH4(+)) also often held within the cluster. Studies thus far have indicated that it is these additional +1 cations, rather than the specific actinyl cation, that direct the structural variation in the complexes formed. We now report the structural characterization of the neptunyl(VI) cluster complex (NH4)13[Na(NpO2)2(A-α-PW9O34)2]·12H2O. The anion in this complex, [Na(NpO2)2(PW9O34)2](13-), contains one Na(+) cation and two {NpO2}(2+) cations held between two [PW9O34](9-) anions, with an additional partial occupancy NH4(+) or {NpO2}(2+) cation also present. In the analogous uranium(VI) system, under similar reaction conditions that include an excess of NH4Cl in the parent solution, it was previously shown that [(NH4)2(U(VI)O2)2(A-PW9O34)2](12-) is the dominant species in both solution and the crystallized salt. Spectroscopic studies provide further proof of differences in the observed chemistry for the {NpO2}(2+)/[PW9O34](9-) and {UO2}(2+)/[PW9O34](9-) systems, both in solution and in solid state complexes crystallized from comparable salt solutions. This work reveals that varying the actinide element (Np vs U) can indeed measurably impact structure and complex stability in the cluster chemistry of actinyl(VI) cations with A-type tri-lacunary heteropolyoxotungstate anions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA