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1.
J Perinatol ; 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38396053

RESUMEN

OBJECTIVE: To compare the rates of death or survival with severe neurodevelopmental impairment (sNDI) at 2 years among extremely preterm infants in relation to pre-pregnancy or first-trimester maternal body mass index (BMI). METHODS: This retrospective cohort study included extremely preterm infants (gestational age 220/7-266/7 weeks). The study was conducted at National Institute of Child Health and Human Development Neonatal Research Network sites. The primary outcome was death or sNDI at 2 years. RESULTS: Data on the primary outcome were available for 1208 children. Death or sNDI was not different among the three groups: 54.9% in normal, 56.1% in overweight, and 53.4% in obese group (p = 0.39). There was no significant difference in mortality, sNDI, moderate/severe cerebral palsy, Bayley Scales of Infant Development (BSID)-III cognitive composite score <70, BSID-III language composite score <70 in adjusted models. CONCLUSION: Neurodevelopmental outcome was not significantly associated with maternal pre-pregnancy BMI among extreme preterm infants.

2.
J Nat Prod ; 87(2): 415-423, 2024 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-38291771

RESUMEN

Pyrrole-containing natural products form a large group of structurally diverse compounds that occur in both terrestrial and marine organisms. In the present study the formation of trideuteromethylated artifacts of pyrrole-containing natural products was investigated, focusing on the discorhabdins. Three deuterated discorhabdins, 1, 3, and 5, were identified to be isolation procedure artifacts caused by the presence of DMSO-d6 during NMR sample preparation and handling. Three additional semisynthetic derivatives, 7-9, were made during the investigation of the mechanism of formation, which was shown to be driven by trideuteromethyl radicals in the presence of water, methanol, TFA, and traces of iron in the deuterated solvent. Generation of trideuteromethylated artifacts was also confirmed for other classes of pyrrole-containing metabolites, namely, makaluvamines, tambjamines, and dibromotryptamines, which had also been dissolved in DMSO-d6 during the structure elucidation process. Semisynthetic discorhabdins were assessed for antiproliferative activity against a panel of human tumor cell lines, and 14-trideuteromethyldiscorhabdin L (3) averaged low micromolar potency.


Asunto(s)
Productos Biológicos , Dimetilsulfóxido , Humanos , Dimetilsulfóxido/química , Pirroles/química , Productos Biológicos/farmacología , Artefactos , Solventes/química
3.
Chem Sci ; 14(43): 12331-12338, 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37969605

RESUMEN

Chalcohalides are desirable semiconducting materials due to their enhanced light-absorbing efficiency and stability compared to lead halide perovskites. However, unlike perovskites, tuning the optical properties of chalcohalides by mixing different halide ions into their structure remains to be explored. Here, we present an effective strategy for halide-alloying Pb3SBrxI4-x (1 ≤ x ≤ 3) using a solution-phase approach and study the effect of halide-mixing on structural and optical properties. We employ a combination of X-ray diffraction, electron microscopy, and solid-state NMR spectroscopy to probe the chemical structure of the chalcohalides and determine mixed-halide incorporation. The absorption onsets of the chalcohalides blue-shift to higher energies as bromide replaces iodide within the structure. The photoluminescence maxima of these materials mimics this trend at both the ensemble and single particle fluorescence levels, as observed by solution-phase and single particle fluorescence microscopy, respectively. These materials exhibit superior stability against moisture compared to traditional lead halide perovskites, and IR spectroscopy reveals that the chalcohalide surfaces are terminated by both amine and carboxylate ligands. Electronic structure calculations support the experimental band gap widening and volume reduction with increased bromide incorporation, and provide useful insight into the likely atomic coloring patterns of the different mixed-halide compositions. Ultimately, this study expands the range of tunability that is achievable with chalcohalides, which we anticipate will improve the suitability of these semiconducting materials for light absorbing and emission applications.

4.
Front Public Health ; 11: 1249614, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37937074

RESUMEN

Introduction: The SARS-CoV-2 pandemic represented a formidable scientific and technological challenge to public health due to its rapid spread and evolution. To meet these challenges and to characterize the virus over time, the State of California established the California SARS-CoV-2 Whole Genome Sequencing (WGS) Initiative, or "California COVIDNet". This initiative constituted an unprecedented multi-sector collaborative effort to achieve large-scale genomic surveillance of SARS-CoV-2 across California to monitor the spread of variants within the state, to detect new and emerging variants, and to characterize outbreaks in congregate, workplace, and other settings. Methods: California COVIDNet consists of 50 laboratory partners that include public health laboratories, private clinical diagnostic laboratories, and academic sequencing facilities as well as expert advisors, scientists, consultants, and contractors. Data management, sample sourcing and processing, and computational infrastructure were major challenges that had to be resolved in the midst of the pandemic chaos in order to conduct SARS-CoV-2 genomic surveillance. Data management, storage, and analytics needs were addressed with both conventional database applications and newer cloud-based data solutions, which also fulfilled computational requirements. Results: Representative and randomly selected samples were sourced from state-sponsored community testing sites. Since March of 2021, California COVIDNet partners have contributed more than 450,000 SARS-CoV-2 genomes sequenced from remnant samples from both molecular and antigen tests. Combined with genomes from CDC-contracted WGS labs, there are currently nearly 800,000 genomes from all 61 local health jurisdictions (LHJs) in California in the COVIDNet sequence database. More than 5% of all reported positive tests in the state have been sequenced, with similar rates of sequencing across 5 major geographic regions in the state. Discussion: Implementation of California COVIDNet revealed challenges and limitations in the public health system. These were overcome by engaging in novel partnerships that established a successful genomic surveillance program which provided valuable data to inform the COVID-19 public health response in California. Significantly, California COVIDNet has provided a foundational data framework and computational infrastructure needed to respond to future public health crises.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiología , Genómica , California/epidemiología , Manejo de Datos
5.
J Nat Prod ; 86(10): 2283-2293, 2023 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-37843072

RESUMEN

The DNAJB1-PRKACA oncogenic gene fusion results in an active kinase enzyme, J-PKAcα, that has been identified as an attractive antitumor target for fibrolamellar hepatocellular carcinoma (FLHCC). A high-throughput assay was used to identify inhibitors of J-PKAcα catalytic activity by screening the NCI Program for Natural Product Discovery (NPNPD) prefractionated natural product library. Purification of the active agent from a single fraction of an Aplidium sp. marine tunicate led to the discovery of two unprecedented alkaloids, aplithianines A (1) and B (2). Aplithianine A (1) showed potent inhibition against J-PKAcα with an IC50 of ∼1 µM in the primary screening assay. In kinome screening, 1 inhibited wild-type PKA with an IC50 of 84 nM. Further mechanistic studies including cocrystallization and X-ray diffraction experiments revealed that 1 inhibited PKAcα catalytic activity by competitively binding to the ATP pocket. Human kinome profiling of 1 against a panel of 370 kinases revealed potent inhibition of select serine/threonine kinases in the CLK and PKG families with IC50 values in the range ∼11-90 nM. An efficient, four-step total synthesis of 1 has been accomplished, enabling further evaluation of aplithianines as biologically relevant kinase inhibitors.


Asunto(s)
Productos Biológicos , Carcinoma Hepatocelular , Humanos , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas , Carcinoma Hepatocelular/patología , Serina , Proteínas del Choque Térmico HSP40/química , Proteínas del Choque Térmico HSP40/genética , Proteínas del Choque Térmico HSP40/metabolismo
6.
J Am Chem Soc ; 145(41): 22762-22775, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37813388

RESUMEN

The inertness of elemental selenium is a significant obstacle in the synthesis of selenium-containing materials at low reaction temperatures. Over the years, several recipes have been developed to overcome this hurdle; however, most of the methods are associated with the use of highly toxic, expensive, and environmentally harmful reagents. As such, there is an increasing demand for the design of cheap, stable, and nontoxic reactive selenium precursors usable in the low-temperature synthesis of transition metal selenides with vast applications in nanotechnology, thermoelectrics, and superconductors. Herein, a novel synthetic route has been developed for activating elemental selenium by using a solvothermal approach. By comprehensive 77Se NMR, Raman, and infrared spectroscopies and gas chromatography-mass spectrometry, we show that the activated Se solution contained HSe-, [Se-Se]2-, and Se2- ions, as well as dialkyl selenide (R2Se) and dialkyl diselenide (R-Se-Se-R) species in dynamic equilibrium. This also corresponded to the first observation of naked Se22- in solution. The versatility of the developed Se precursor was demonstrated by the successful synthesis of (i) the polycrystalline room-temperature modification of the ß-Ag2Se thermoelectric material; (ii) large single crystals of superconducting ß-FeSe; (iii) CdSe nanocrystals with different particle sizes (3-10 nm); (iv) nanosheets of PtSe2; and (v) mono- and dibenzyl selenides and diselenides at room temperature. The simplicity and diversity of the developed Se activation method holds promise for applied and fundamental research.

7.
Mar Drugs ; 21(9)2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37755087

RESUMEN

A library of naturally occurring and semi-synthetic discorhabdins was assessed for their effects on Merkel cell carcinoma (MCC) cell viability. The set included five new natural products and semi-synthetic compounds whose structures were elucidated with NMR, HRMS, and ECD techniques. Several discorhabdins averaged sub-micromolar potency against the MCC cell lines tested and most of the active compounds showed selectivity towards virus-positive MCC cell lines. An investigation of structure-activity relationships resulted in an expanded understanding of the crucial structural features of the discorhabdin scaffold. Mechanistic cell death assays suggested that discorhabdins, unlike many other MCC-active small molecules, do not induce apoptosis, as shown by the lack of caspase activation, annexin V staining, and response to caspase inhibition. Similarly, discorhabdin treatment failed to increase MCC intracellular calcium and ROS levels. In contrast, the rapid loss of cellular reducing potential and mitochondrial membrane potential suggested that discorhabdins induce mitochondrial dysfunction leading to non-apoptotic cell death.


Asunto(s)
Alcaloides , Carcinoma de Células de Merkel , Neoplasias Cutáneas , Humanos , Carcinoma de Células de Merkel/tratamiento farmacológico , Muerte Celular , Relación Estructura-Actividad , Alcaloides/farmacología , Caspasas , Neoplasias Cutáneas/tratamiento farmacológico
8.
ACS Appl Mater Interfaces ; 15(32): 38201-38213, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37526921

RESUMEN

Wearable biosensors promise real-time measurements of chemicals in human sweat, with the potential for dramatic improvements in medical diagnostics and athletic performance through continuous metabolite and electrolyte monitoring. However, sweat sensing is still in its infancy, and questions remain about whether sweat can be used for medical purposes. Wearable sensors are focused on proof-of-concept designs that are not scalable for multisubject trials, which could elucidate the utility of sweat sensing for health monitoring. Moreover, many wearable sensors do not include the microfluidics necessary to protect and channel consistent and clean sweat volumes to the sensor surface or are not designed to be disposable to prevent sensor biofouling and inaccuracies due to repeated use. Hence, there is a need to produce low-cost and single-use wearable sensors with integrated microfluidics to ensure reliable sweat sensing. Herein, we demonstrate the convergence of laser-induced graphene (LIG) based sensors with soft tape polymeric microfluidics to quantify both sweat metabolites (glucose and lactate) and electrolytes (sodium) for potential hydration and fatigue monitoring. Distinct LIG-electrodes were functionalized with glucose oxidase and lactate oxidase for selective sensing of glucose and lactate across physiological ranges found in sweat with sensitivities of 26.2 and 2.47 × 10-3 µA mM-1 cm-2, detection limits of 8 and 220 µM, and linear response ranges of 0-1 mM and 0-32 mM, respectively. LIG-electrodes functionalized with a sodium-ion-selective membrane displayed Nernstian sensitivity of 58.8 mV decade-1 and a linear response over the physiological range in sweat (10-100 mM). The sensors were tested in a simulated sweating skin microfluidic system and on-body during cycling tests in a multisubject trial. Results demonstrate the utility of LIG integrated with microfluidics for real-time, continuous measurements of biological analytes in sweat and help pave the way for the development of personalized wearable diagnostic tools.


Asunto(s)
Técnicas Biosensibles , Grafito , Dispositivos Electrónicos Vestibles , Humanos , Sudor , Sudoración , Microfluídica , Técnicas Biosensibles/métodos , Sodio , Ácido Láctico , Polímeros , Glucosa
9.
Microb Genom ; 9(7)2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37428142

RESUMEN

We have adopted an open bioinformatics ecosystem to address the challenges of bioinformatics implementation in public health laboratories (PHLs). Bioinformatics implementation for public health requires practitioners to undertake standardized bioinformatic analyses and generate reproducible, validated and auditable results. It is essential that data storage and analysis are scalable, portable and secure, and that implementation of bioinformatics fits within the operational constraints of the laboratory. We address these requirements using Terra, a web-based data analysis platform with a graphical user interface connecting users to bioinformatics analyses without the use of code. We have developed bioinformatics workflows for use with Terra that specifically meet the needs of public health practitioners. These Theiagen workflows perform genome assembly, quality control, and characterization, as well as construction of phylogeny for insights into genomic epidemiology. Additonally, these workflows use open-source containerized software and the WDL workflow language to ensure standardization and interoperability with other bioinformatics solutions, whilst being adaptable by the user. They are all open source and publicly available in Dockstore with the version-controlled code available in public GitHub repositories. They have been written to generate outputs in standardized file formats to allow for further downstream analysis and visualization with separate genomic epidemiology software. Testament to this solution meeting the requirements for bioinformatic implementation in public health, Theiagen workflows have collectively been used for over 5 million sample analyses in the last 2 years by over 90 public health laboratories in at least 40 different countries. Continued adoption of technological innovations and development of further workflows will ensure that this ecosystem continues to benefit PHLs.


Asunto(s)
Ecosistema , Salud Pública , Programas Informáticos , Biología Computacional/métodos , Genómica
10.
Microb Genom ; 9(6)2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37267020

RESUMEN

The capacity for pathogen genomics in public health expanded rapidly during the coronavirus disease 2019 (COVID-19) pandemic, but many public health laboratories did not have the infrastructure in place to handle the vast amount of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequence data generated. The California Department of Public Health, in partnership with Theiagen Genomics, was an early adopter of cloud-based resources for bioinformatics and genomic epidemiology, resulting in the creation of a SARS-CoV-2 genomic surveillance system that combined the efforts of more than 40 sequencing laboratories across government, academia and industry to form California COVIDNet, California's SARS-CoV-2 Whole-Genome Sequencing Initiative. Open-source bioinformatics workflows, ongoing training sessions for the public health workforce, and automated data transfer to visualization tools all contributed to the success of California COVIDNet. While challenges remain for public health genomic surveillance worldwide, California COVIDNet serves as a framework for a scaled and successful bioinformatics infrastructure that has expanded beyond SARS-CoV-2 to other pathogens of public health importance.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiología , Salud Pública , Laboratorios , Genómica , California/epidemiología
11.
ACS Pharmacol Transl Sci ; 6(4): 633-650, 2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37082750

RESUMEN

The recent demonstration that adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) plays an oncogenic role in a number of important cancers has led to a renaissance in drug development interest targeting this kinase. We therefore have established a suite of biochemical, cell-based, and structural biology assays for identifying and evaluating new pharmacophores for PKA inhibition. This discovery process started with a 384-well high-throughput screen of more than 200,000 substances, including fractionated natural product extracts. Identified active compounds were further prioritized in biochemical, biophysical, and cell-based assays. Priority lead compounds were assessed in detail to fully characterize several previously unrecognized PKA pharmacophores including the generation of new X-ray crystallography structures demonstrating unique interactions between PKA and bound inhibitor molecules.

12.
ACS Meas Sci Au ; 3(1): 53-61, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36817011

RESUMEN

Silver(I) ions have the propensity of undergoing reduction to form metallic silver within olefin/paraffin separation systems when they are subjected to hydrogen at elevated temperatures. Ionic liquids (ILs) are versatile solvents known for their low vapor pressure, high thermal stability, and structural tunability and have been shown to minimize hydrogen-induced reduction of silver(I) ions when employed as solvents. In the development of robust separation platforms that employ silver(I) ions, it is essential to deploy reliable approaches capable of measuring and assessing the factors that lower the overall separation performance. In this study, silver(I) ions dissolved in an imidazolium-based IL are subjected to mixed gas streams composed of hydrogen, nitrogen, and methane under varying temperatures. Using inverse gas chromatography, a total of 44 columns with stationary phases containing four different concentrations of silver(I) bis[(trifluoromethyl)sulfonyl]imide ([Ag+][NTf2 -]) dissolved in the 1-decyl-3-methylimidazolium ([C10MIM+]) [NTf2 -] IL were used to measure partition coefficients of olefins and paraffins, as well as aromatics, esters, and ketones. Upon exposing the stationary phases to mixed gases at elevated temperatures, olefin partitioning between the silver(I) ion pseudophase and the two other phases (i.e., carrier gas and IL stationary phase) was observed to decrease over time, while partitioning between the IL stationary phase and carrier gas remained unchanged. It was found that exposure gases composed of 5.0 to 85.0 mol % hydrogen and temperatures ranging from 95 to 130 °C resulted in a remarkable acceleration of silver(I) ion reduction and an approximate 36.4-61.3% decrease in olefin partitioning between the silver(I) ion pseudophase and both the carrier gas and IL stationary phase after 60 h. While binary mixtures of hydrogen and nitrogen resulted in a continuous decrease in silver(I) ion-olefin complexation capability, a ternary gas mixture produced varied silver(I) ion reduction kinetics.

13.
Am J Rhinol Allergy ; 37(4): 419-428, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36847244

RESUMEN

BACKGROUND: Previous research has shown diminished nasal immune function following nasal saline irrigation (NSI), returning to baseline at 6 hours. The aim of this study was to examine the immune nasal proteome before and after 14 days of nasal irrigation. METHODS: Seventeen healthy volunteers received either isotonic (IsoSal) or low salt (LowNa) NSI. Nasal secretions were collected before and 30 min after NSI at baseline and again after 14 days. Specimens were analyzed using mass spectrometry to detect proteins of relevance to nasal immune function. RESULTS: One thousand eight hundred and sixty-five proteins were identified with significant changes in 71 proteins, of which 23 were identified as part of the innate immune system. Baseline analysis demonstrated an increase of 9 innate proteins after NSI, most after IsoSal. After 14 days, a greater increase in innate peptides was present, with most now in the LowNa group. When NSI solutions were compared, a significant increase in 4 innate proteins, including a 211% in lysozyme, was detected in the LowNa group. CONCLUSION: LowNa NSI demonstrates evidence of improving the innate immune secretions, especially lysozyme, in healthy volunteers.


Asunto(s)
Rinitis , Sinusitis , Humanos , Proteoma , Muramidasa , Proyectos Piloto , Solución Salina , Lavado Nasal (Proceso)/métodos , Inmunidad Innata , Irrigación Terapéutica/métodos
14.
Org Lett ; 24(51): 9468-9472, 2022 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-36516994

RESUMEN

A new dimeric alkaloid plakoramine A [(±)-1] was identified from a marine sponge Plakortis sp. Chiral-phase HPLC separation of (±)-1 led to the purified enantiomers (+)-1 and (-)-1 which both potently inhibited CBL-B E3 ubiquitin ligase activities. The absolute configurations of the enantiomers were determined by quantum chemical calculations. Scrutinization of the purification conditions revealed a previously undescribed, nonenzymatic route to form (±)-1 via photochemical conversion of its naturally occurring monomeric counterpart, plakinidine B (2).


Asunto(s)
Dimerización
15.
J Phys Chem Lett ; 13(47): 10924-10928, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36395418

RESUMEN

Layered transition-metal dichalcogenides (TMDs) are the focus of intense research owing to their semiconducting properties and applications in many fields of research. In addition to intercalation and exfoliation, physical strain modulation has been reported as a way to mechanically induce the slippage of layers and influence the properties of TMDs. In this work, we report the chemically induced slippage of layers in bulk tungsten diselenide (WSe2). Powder X-ray diffraction, Raman spectroscopy, electron microscopy, and thermal analysis suggest that slippage is easily achieved by grinding in the presence of common solvents. Chemically induced slippage of TMDs may represent an intermediate step leading to the exfoliation of these materials. We anticipate that chemical slippage will widen the synthetic utility and advance our understanding of the mechanical and optoelectronic properties of layered materials.

16.
Langmuir ; 38(46): 14017-14024, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36346803

RESUMEN

Deep eutectic solvents (DESs) are a tunable class of solvents with many advantageous properties including good thermal stability, facile synthesis, low vapor pressure, and low-to-negligible toxicity. DESs are composed of hydrogen bond donors and acceptors that, when combined, significantly decrease the freezing point of the resulting solvent. DESs have distinct interfacial and bulk structural heterogeneity compared to traditional solvents, in part due to various intramolecular and intermolecular interactions. Many of the physiochemical properties observed for DESs are influenced by structure. However, our understanding of the interfacial and bulk structure of DESs is incomplete. To fully exploit these solvents in a range of applications including catalysis, separations, and electrochemistry, a better understanding of DES structure must be obtained. In this Perspective, we provide an overview of the current knowledge of the interfacial and bulk structure of DESs and suggest future research directions to improve our understanding of this important information.

17.
Glob Chall ; 6(9): 2200057, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36176938

RESUMEN

Glyphosate is a globally applied herbicide yet it has been relatively undetectable in-field samples outside of gold-standard techniques. Its presumed nontoxicity toward humans has been contested by the International Agency for Research on Cancer, while it has been detected in farmers' urine, surface waters and crop residues. Rapid, on-site detection of glyphosate is hindered by lack of field-deployable and easy-to-use sensors that circumvent sample transportation to limited laboratories that possess the equipment needed for detection. Herein, the flavoenzyme, glycine oxidase, immobilized on platinum-decorated laser-induced graphene (LIG) is used for selective detection of glyphosate as it is a substrate for GlyOx. The LIG platform provides a scaffold for enzyme attachment while maintaining the electronic and surface properties of graphene. The sensor exhibits a linear range of 10-260 µ m, detection limit of 3.03 µ m, and sensitivity of 0.991 nA µ m -1. The sensor shows minimal interference from the commonly used herbicides and insecticides: atrazine, 2,4-dichlorophenoxyacetic acid, dicamba, parathion-methyl, paraoxon-methyl, malathion, chlorpyrifos, thiamethoxam, clothianidin, and imidacloprid. Sensor function is further tested in complex river water and crop residue fluids, which validate this platform as a scalable, direct-write, and selective method of glyphosate detection for herbicide mapping and food analysis.

18.
J Phys Chem B ; 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35649257

RESUMEN

Alkylimidazolium chloride ionic liquids (ILs) have many uses in a variety of separation systems, including micro-confined separation systems. To understand the separation mechanism in these systems, the diffusion properties of analytes in ILs under relevant operating conditions, including micro-confinement dimension and temperature, should be known. For example, separation efficiencies for various IL-based microextraction techniques are dependent on the sample volume and temperature. Temperature-dependent (20-100 °C) fluorescence recovery after photobleaching (FRAP) was utilized to determine the diffusion properties of a zwitterionic, hydrophilic dye, ATTO 647, in alkylimidazolium chloride ILs in micro-confined geometries. These micro-confined geometries were generated by sandwiching the IL between glass substrates that were separated by ∼1 to 100 µm. From the measured temperature-dependent FRAP data, we note alkyl chain length-, thickness-, and temperature-dependent diffusion coefficients, with values ranging from 0.021 to 46 µm2/s. Deviations from Brownian diffusion are observed at lower temperatures and increasingly less so at elevated temperatures; the differences are attributed to alterations in intermolecular interactions that reduce temperature-dependent nanoscale structural heterogeneities. The temperature- and thickness-dependent data provide a useful foundation for efficient design of micro-confined IL separation systems.

19.
J Nat Prod ; 85(6): 1603-1616, 2022 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-35696348

RESUMEN

Seven new peptaibols named tolypocladamides A-G have been isolated from an extract of the fungus Tolypocladium inflatum, which inhibits the interaction between Raf and oncogenic Ras in a cell-based high-throughput screening assay. Each peptaibol contains 11 amino acid residues, an octanoyl or decanoyl fatty acid chain at the N-terminus, and a leucinol moiety at the C-terminus. The peptaibol sequences were elucidated on the basis of 2D NMR and mass spectral fragmentation analyses. Amino acid configurations were determined by advanced Marfey's analyses. Tolypocladamides A-G caused significant inhibition of Ras/Raf interactions with IC50 values ranging from 0.5 to 5.0 µM in a nanobioluminescence resonance energy transfer (NanoBRET) assay; however, no interactions were observed in a surface plasmon resonance assay for binding of the compounds to wild type or G12D mutant Ras constructs or to the Ras binding domain of Raf. NCI 60 cell line testing was also conducted, and little panel selectivity was observed.


Asunto(s)
Antineoplásicos , Hypocreales , Aminoácidos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Hypocreales/química , Peptaiboles/farmacología
20.
Inorg Chem ; 61(1): 154-169, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34902243

RESUMEN

A precipitation method involving a deep eutectic solvent (DES)─a mixture of hydrogen bond donor and acceptor─is used to synthesize a ternary metal oxide. Without toxic reagents, precipitates consisting of Zn3(OH)2V2O7·nH2O and Zn5(OH)6(CO3)2 are obtained by simply introducing deionized H2O to the DES solution containing dissolved ZnO and V2O5. Manipulation of the synthetic conditions demonstrates high tunability in the size/morphology of the two-dimensional nanosheets precipitated during the dynamic equilibrium process. According to differential scanning calorimetry and high-temperature powder X-ray diffraction, Zn3V2O8 and ZnO obtained by the annealing of the precipitate are intermediates in the reaction pathway toward metastable Zn4V2O9. Intimate mixing of the metal precursors achieved by the precipitation method allows access to the metastable zinc-rich vanadate with unusually rapid heat treatment. The UV-vis and surface photovoltage spectra reveal the presence of sub-band gap states, stemming from the reduced vanadium (V4+) center. Photoelectrochemical measurements confirm weak photoanodic currents for water and methanol oxidation. For the first time, this work shows the synthesis of a metastable oxide with the DES-precipitation route and provides insight into the structure-property relationship of the zinc-rich vanadate.

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