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BACKGROUND: Anaphylaxis is an acute and serious allergic reaction. Little is known about physician adherence to anaphylaxis guidelines among patients across different age groups. OBJECTIVE: To investigate real-world physician adherence to anaphylaxis guidelines among children, adults, and older adults in emergency departments. METHODS: This study retrospectively analyzed all consecutive patients with anaphylaxis who presented to 2 emergency departments at 2 branches of the largest tertiary hospital in Taiwan, between 2001 and 2020. Patients who met the diagnostic criteria for anaphylaxis were enrolled and grouped by age: children (<18 years), adults (18-64 years), and older adults (≥65 years). RESULTS: We enrolled 771 patients with anaphylaxis (159 children, 498 adults, and 114 older adults). Intramuscular epinephrine was administered in 294 cases (38.1%). There was a significant age-group difference in the rate of intramuscular epinephrine administration (46.5% in children, 37.3% in adults, and 29.8% in older adults; P trend = .004). When stratified by severity, 14.3% of older adults with moderate reactions received intramuscular epinephrine, whereas 35.2% of adults and 55.3% of children received intramuscular epinephrine (P trend < .001), whereas such difference was not found in patients with severe reactions. Upon discharge from emergency departments, 15.3% received allergist referral (52.2% in children, 6.6% in adults, and 1.8% in older adults; P trend < .001); 12.5% received education on avoidance of triggers (18.9%, 11.4%, and 7.9%; P trend = .01), and 16.1% received education on alarm symptoms (21.4%, 15.1%, and 13.2%; P trend = .05). CONCLUSION: The real-world physician adherence to anaphylaxis guidelines remains suboptimal in emergency departments, particularly among older adults. Physician continuing education is needed to improve the gap between anaphylaxis guidelines and clinical practice.
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Anafilaxia , Médicos , Adolescente , Anciano , Niño , Humanos , Anafilaxia/diagnóstico , Anafilaxia/tratamiento farmacológico , Servicio de Urgencia en Hospital , Epinefrina/uso terapéutico , Inyecciones Intramusculares , Estudios Retrospectivos , Adulto , Recién Nacido , Preescolar , Adulto Joven , Persona de Mediana Edad , TaiwánRESUMEN
BACKGROUND: Few data are available in Asian children regarding the validity of cord blood immunoglobulin E (IgE) in predicting allergic sensitization and pulmonary function. The relationship between cord blood IgE and fraction of exhaled nitric oxide (FeNO) remains unknown. This study investigated the associations of cord blood IgE with allergic sensitization, FeNO, pulmonary function, and allergic diseases in Asian children. METHODS: Five hundred and sixty-six Asian children with valid cord blood IgE measurements at birth participated a 6-year follow-up visit including a questionnaire, serum total and allergen-specific IgE, FeNO measurement, and spirometry. Regression-based analyses with covariates adjustment were applied. RESULTS: Cord blood IgE levels were significantly associated with FeNO levels (ß = 0.131, p < .001) and serum total IgE levels (ß = 0.325, p < .001). Cord blood IgE levels were positively associated with allergic sensitization (adjusted odds ratio [AOR] = 2.22, p < .001), and sensitization to mites (p = .002), animals (p = .023), and foods (p = .048). Subjects with cord blood IgE ≥0.24 kU/L (the optimal cutoff) were significantly associated with an increased risk of allergic sensitization (AOR = 2.63, p < .001) and asthma (AOR = 2.35, p = .024) than those with cord blood IgE <0.24 kU/L. Subjects with cord blood IgE ≥0.24 kU/L had significantly higher FeNO levels than those with cord blood IgE <0.24 kU/L (p = .028). There were no significant associations between cord blood IgE levels and pulmonary function parameters. CONCLUSION: Cord blood IgE ≥0.24 kU/L predicts allergic sensitization, FeNO elevation, and asthma among Asian schoolchildren, suggesting cord blood IgE would be useful for identifying newborns at risk of subsequent allergic sensitization and allergic airway inflammation.
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Asma , Óxido Nítrico , Animales , Asma/complicaciones , Asma/diagnóstico , Asma/epidemiología , Espiración , Sangre Fetal , Humanos , Inmunoglobulina E , Óxido Nítrico/análisisRESUMEN
Background: Previous studies suggest the association between early-life weight gain and asthma. It remains unclear whether early-life weight gain is associated with atopic or non-atopic asthma. This study aimed to investigate whether early-life weight gain is associated with atopic or non-atopic asthma. Methods: Included in this study were 1343 singleton-birth children (761 boys, 57%) born between January 2010 and December 2011 participating in the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort were evaluated by a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and interviewed by pediatricians between July 1, 2016 and May 31, 2018 at the mean age of 6.4 years. Weight gain z-scores during the first 6, 12, and 18 months of life were classified into 4 groups: slow (below -0.67), on track (-0.67 to 0.67), rapid (0.67 to 1.28), and extremely rapid (above 1.28). The main outcomes were atopic and non-atopic asthma. Asthma was defined as having physician-diagnosed asthma and the presence of wheeze or asthma exacerbations in the last 12 months. Atopy was determined by Phadiatop Infant. Results: The extremely rapid weight gain group of children during the first 6, 12, and 18 months of life was significantly associated with an increased risk of non-atopic asthma (adjusted odd ratio [AOR], 2.14, 95% confidence interval [CI], 1.01-4.53 for the first 6 months; AOR, 2.86, 95% CI, 1.34-6.14 for the first 12 months; AOR, 3.26, 95% CI 1.49-7.15 for the first 18 months) compared with the on track group. No significant association was found in atopic asthma. A sex-stratified analysis revealed the association of early-life weight gain with non-atopic asthma was statistically significant only in boys (AOR, 4.24, 95% CI, 1.44-12.50). Conclusion: Extremely rapid weight gain during the first 6-18 months of life was significantly associated with 2.1- to 3.3-fold increased risk of non-atopic asthma, with a more pronounced risk found in boys.
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Despite the rapid worldwide expansion of parks with outdoor fitness equipment (OFE), no objective data regarding the intensity of activity associated with using OFE are available. Hence, this study quantified the energy expenditure and intensity of physical activity by examining four outdoor fitness devices widely used by older adults and provides objective evidence-based intensity references for the Compendium of Physical Activities. Sixteen older adults (mean age: 70.7 ± 5.6 yr) equipped with a portable metabolic system for measuring energy expenditure and activity intensity completed tasks while walking or using four types of OFE. Descriptive statistics and repeated-measures ANOVA with the Bonferroni post hoc test were employed. The energy expenditure and activity intensity for using an air walker at tempos of 80, 100, and 120 bpm were 50.78 ± 14.76 (2.81 ± 0.85), 59.62 ± 14.23 (3.26 ± 0.82), and 65.62 ± 18.27 (3.55 ± 1.02) cal/kg/min (METs), respectively. The induced energy and intensity output values for a ski machine were 54.00 ± 14.31 (3.02 ± 0.87), 68.87 ± 22.74 (3.82 ± 1.35), and 74.55 ± 23.39 (4.05 ± 1.35) cal/kg/min (METs), at 80, 100, and 120 bpm, respectively. The energy output for a waist twister at 60 bpm was 38.43 ± 20.16 cal/kg/min (2.05 ± 1.15 METs), and that for a double arm stretch at 80 bpm was 31.05 ± 12.58 cal/kg/min (1.63 ± 0.70 METs). These findings indicate that activity on the ski machine and air walker could be considered to have moderate intensity, whereas the intensity of activity on the waist twister and double arm stretch was significantly lower than that for walking at either 3.2 km/h or 4 km/h and could be considered only light intensity. The MET values for the OFE were lower than those for similar indoor fitness equipment. The results of this study provide crucial implications for public health practices concerning the development of active living environments.
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Envejecimiento , Prueba de Esfuerzo/métodos , Ejercicio Físico , Aptitud Física , Anciano , Análisis de Varianza , Calorimetría , Metabolismo Energético , Medicina Basada en la Evidencia , Prueba de Esfuerzo/instrumentación , Femenino , Promoción de la Salud/métodos , Humanos , Masculino , CaminataRESUMEN
More than 80% of ammonia (NH3) in the steel manufacturing process wastewater is contributed from the coking wastewater, which is usually treated by biological processes. However, the NH3 in the coking wastewater is typically too high for biological treatment due to its inhibitory concentration. Therefore, a two-stage process including a hollow fiber membrane contactor (HFMC) and a modified membrane distillation (MD) system was developed and applied to reduce and recover NH3 from coking wastewater. The objectives of this paper are to evaluate different membrane materials, receiving solutions, and operation parameters for the system, remove NH3 from the coking wastewater to less than 300 mg N/L, which is amenable to the biological process, and recover ammonia solution for reuse. As a result, the polytetrafluoroethylene (PTFE) HFMC using sulfuric acid as a receiving solution can achieve a maximum NH3-N transmembrane flux of 1.67 g N/m²·h at pH of 11.5 and reduce NH3 in the coking wastewater to less than 300 mg N/L. The NH3 in the converted ammonium sulfate ((NH4)2SO4) was then recovered by the modified MD using ice water as the receiving solution to produce ≥3% of ammonia solution for reuse.
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Amoníaco/aislamiento & purificación , Coque/análisis , Destilación/métodos , Membranas Artificiales , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Contaminantes Químicos del Agua/aislamiento & purificación , Monitoreo del Ambiente/métodos , Estudios de Factibilidad , TaiwánRESUMEN
Titanium dioxide (TiO2)/ activated carbon (AC) composite materials, as capacitive deionization electrodes, were prepared by a two-step microwave-assisted ionothermal synthesis method. The electrosorption capacity of the composite electrodes was studied and the effects of AC characteristics were explored. These effects were investigated by multiple analytical techniques, including X-ray photoelectron spectroscopy, thermogravimetry analysis and electrochemical impedance spectroscopy, etc. The experimental results indicated that the electrosorption capacity of the TiO2/AC composite electrode is dependent on the characteristics of AC including the pore structure and the surface property. An enhancement in electrosorption capacity was observed for the TiO2/AC composite electrode prepared from the AC with higher mesopore content and less hydrophilic surface. This enhancement is due to the deposition of anatase TiO2 with suitable amount of Ti-OH. On the other hand, a decline in electrosorption capacity was observed for the TiO2/AC composite electrode prepared from the AC with higher micropore content and highly hydrophilic surface. High content of hydrogen bond complex formed between the functional group on hydrophilic surface with H2O, which will slow down the TiO2 precursor-H2O reaction. In such situation, the effect of TiO2 becomes unfavorable as the loading amount of TiO2 is less and the micropore can also be blocked.
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The roles of 2-oxoglutarate (2OG)-dependent prolyl-hydroxylases in eukaryotes include collagen stabilization, hypoxia sensing, and translational regulation. The hypoxia-inducible factor (HIF) sensing system is conserved in animals, but not in other organisms. However, bioinformatics imply that 2OG-dependent prolyl-hydroxylases (PHDs) homologous to those acting as sensing components for the HIF system in animals occur in prokaryotes. We report cellular, biochemical, and crystallographic analyses revealing that Pseudomonas prolyl-hydroxylase domain containing protein (PPHD) contain a 2OG oxygenase related in structure and function to the animal PHDs. A Pseudomonas aeruginosa PPHD knockout mutant displays impaired growth in the presence of iron chelators and increased production of the virulence factor pyocyanin. We identify elongation factor Tu (EF-Tu) as a PPHD substrate, which undergoes prolyl-4-hydroxylation on its switch I loop. A crystal structure of PPHD reveals striking similarity to human PHD2 and a Chlamydomonas reinhardtii prolyl-4-hydroxylase. A crystal structure of PPHD complexed with intact EF-Tu reveals that major conformational changes occur in both PPHD and EF-Tu, including a >20-Å movement of the EF-Tu switch I loop. Comparison of the PPHD structures with those of HIF and collagen PHDs reveals conservation in substrate recognition despite diverse biological roles and origins. The observed changes will be useful in designing new types of 2OG oxygenase inhibitors based on various conformational states, rather than active site iron chelators, which make up most reported 2OG oxygenase inhibitors. Structurally informed phylogenetic analyses suggest that the role of prolyl-hydroxylation in human hypoxia sensing has ancient origins.
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Oxígeno/metabolismo , Factor Tu de Elongación Peptídica/metabolismo , Prolina/metabolismo , Pseudomonas putida/metabolismo , Chlamydomonas reinhardtii/metabolismo , Humanos , Hidroxilación , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Prolina Dioxigenasas del Factor Inducible por Hipoxia/química , Prolina Dioxigenasas del Factor Inducible por Hipoxia/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Factor Tu de Elongación Peptídica/química , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Especificidad por SustratoRESUMEN
2-Oxoglutarate (2OG)-dependent oxygenases have important roles in the regulation of gene expression via demethylation of N-methylated chromatin components and in the hydroxylation of transcription factors and splicing factor proteins. Recently, 2OG-dependent oxygenases that catalyse hydroxylation of transfer RNA and ribosomal proteins have been shown to be important in translation relating to cellular growth, TH17-cell differentiation and translational accuracy. The finding that ribosomal oxygenases (ROXs) occur in organisms ranging from prokaryotes to humans raises questions as to their structural and evolutionary relationships. In Escherichia coli, YcfD catalyses arginine hydroxylation in the ribosomal protein L16; in humans, MYC-induced nuclear antigen (MINA53; also known as MINA) and nucleolar protein 66 (NO66) catalyse histidine hydroxylation in the ribosomal proteins RPL27A and RPL8, respectively. The functional assignments of ROXs open therapeutic possibilities via either ROX inhibition or targeting of differentially modified ribosomes. Despite differences in the residue and protein selectivities of prokaryotic and eukaryotic ROXs, comparison of the crystal structures of E. coli YcfD and Rhodothermus marinus YcfD with those of human MINA53 and NO66 reveals highly conserved folds and novel dimerization modes defining a new structural subfamily of 2OG-dependent oxygenases. ROX structures with and without their substrates support their functional assignments as hydroxylases but not demethylases, and reveal how the subfamily has evolved to catalyse the hydroxylation of different residue side chains of ribosomal proteins. Comparison of ROX crystal structures with those of other JmjC-domain-containing hydroxylases, including the hypoxia-inducible factor asparaginyl hydroxylase FIH and histone N(ε)-methyl lysine demethylases, identifies branch points in 2OG-dependent oxygenase evolution and distinguishes between JmjC-containing hydroxylases and demethylases catalysing modifications of translational and transcriptional machinery. The structures reveal that new protein hydroxylation activities can evolve by changing the coordination position from which the iron-bound substrate-oxidizing species reacts. This coordination flexibility has probably contributed to the evolution of the wide range of reactions catalysed by oxygenases.
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Eucariontes/enzimología , Modelos Moleculares , Oxigenasas/química , Células Procariotas/enzimología , Ribosomas/enzimología , Secuencia de Aminoácidos , Dominio Catalítico , Secuencia Conservada , Eucariontes/clasificación , Humanos , Oxigenasas/metabolismo , Filogenia , Células Procariotas/clasificación , Pliegue de Proteína , Estructura Terciaria de Proteína , Alineación de SecuenciaRESUMEN
The selective insertion of CO and CO2 into the C-O and O-H bonds of alcohols by the Se-Ru-CO hydride clusters [(µ-H)Ru4(CO)10Se2](-) (1) and [(µ3-H)Ru5(CO)14Se](-) (2) was demonstrated by a cooperative effect of the protonic hydride, the electron-rich Ru atom, and the electronegative Se atom as well as the symmetry of the clusters. These reactions generated the first examples of Se-containing ruthenium carboxylate and alkylcarbonate clusters [{(µ-H)Ru4(CO)10Se2}2{Ru2(CO)4(µ-η(1):η(1)-OOCR)}](3-) (R = Me, 3; Et, 4) and [{(µ-H)Ru4(CO)10Se2}2{Ru2(CO)4(µ-η(1):η(1)-OOCOR)}](3-) (R = Me, 5; Et, 6), respectively. These results disclosed herein provide a new avenue for the capture and storage of CO and CO2 and useful synthetic routes to novel RCOO(-)- and ROCOO(-)-bridged ruthenium selenide clusters.
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This study proposes a vascular endothelial growth factor (VEGF) biosensor for diagnosing various stages of cervical carcinoma. In addition, VEGF concentrations at various stages of cancer therapy are determined and compared to data obtained by computed tomography (CT) and cancer antigen 125 (CA-125). The increase in VEGF concentrations during operations offers useful insight into dosage timing during cancer therapy. This biosensor uses Avastin as the biorecognition element for the potential cancer biomarker VEGF and is based on a n-type polycrystalline silicon nanowire field-effect transistor (poly-SiNW-FET). Magnetic nanoparticles with poly[aniline-co-N-(1-one-butyric acid) aniline]-Fe3O4 (SPAnH-Fe3O4) shell-core structures are used as carriers for Avastin loading and provide rapid purification due to their magnetic properties, which prevent the loss of bioactivity; furthermore, the high surface area of these structures increases the quantity of Avastin immobilized. Average concentrations in human blood for species that interfere with detection specificity are also evaluated. The detection range of the biosensor for serum samples covers the results expected from both healthy individuals and cancer patients.
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Anticuerpos Monoclonales Humanizados/química , Técnicas Biosensibles , Antígeno Ca-125/sangre , Carcinoma/diagnóstico , Proteínas de la Membrana/sangre , Neoplasias del Cuello Uterino/diagnóstico , Factor A de Crecimiento Endotelial Vascular/sangre , Anticuerpos Monoclonales Humanizados/inmunología , Bevacizumab , Antígeno Ca-125/análisis , Carcinoma/sangre , Carcinoma/inmunología , Carcinoma/patología , Femenino , Óxido Ferrosoférrico/química , Humanos , Imanes , Proteínas de la Membrana/análisis , Nanocables/química , Estadificación de Neoplasias , Silicio/química , Tomografía Computarizada por Rayos X , Transistores Electrónicos , Neoplasias del Cuello Uterino/sangre , Neoplasias del Cuello Uterino/inmunología , Neoplasias del Cuello Uterino/patologíaRESUMEN
A renewed interest in non-coding RNA (ncRNA) has led to the discovery of novel RNA species and post-transcriptional ribonucleoside modifications, and an emerging appreciation for the role of ncRNA in RNA epigenetics. Although much can be learned by amplification-based analysis of ncRNA sequence and quantity, there is a significant need for direct analysis of RNA, which has led to numerous methods for purification of specific ncRNA molecules. However, no single method allows purification of the full range of cellular ncRNA species. To this end, we developed a multidimensional chromatographic platform to resolve, isolate and quantify all canonical ncRNAs in a single sample of cells or tissue, as well as novel ncRNA species. The applicability of the platform is demonstrated in analyses of ncRNA from bacteria, human cells and plasmodium-infected reticulocytes, as well as a viral RNA genome. Among the many potential applications of this platform are a system-level analysis of the dozens of modified ribonucleosides in ncRNA, characterization of novel long ncRNA species, enhanced detection of rare transcript variants and analysis of viral genomes.
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ARN no Traducido/aislamiento & purificación , Cromatografía en Gel/métodos , Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Fase Inversa/métodos , Fluorometría , Humanos , MicroARNs/aislamiento & purificación , Mycobacterium bovis/genética , Plasmodium berghei/genética , ARN Bacteriano/aislamiento & purificación , ARN Protozoario/aislamiento & purificación , ARN Ribosómico/aislamiento & purificación , ARN de Transferencia/aislamiento & purificación , ARN Viral/aislamiento & purificaciónRESUMEN
The finding that oxygenase-catalyzed protein hydroxylation regulates animal transcription raises questions as to whether the translation machinery and prokaryotic proteins are analogously modified. Escherichia coli ycfD is a growth-regulating 2-oxoglutarate oxygenase catalyzing arginyl hydroxylation of the ribosomal protein Rpl16. Human ycfD homologs, Myc-induced nuclear antigen (MINA53) and NO66, are also linked to growth and catalyze histidyl hydroxylation of Rpl27a and Rpl8, respectively. This work reveals new therapeutic possibilities via oxygenase inhibition and by targeting modified over unmodified ribosomes.
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Proteínas de Escherichia coli/metabolismo , Oxigenasas de Función Mixta/metabolismo , Oxigenasas/metabolismo , Células Procariotas/metabolismo , Ribosomas/metabolismo , Animales , Arginina/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Dioxigenasas , Inhibidores Enzimáticos/farmacología , Escherichia coli/metabolismo , Proteínas de Escherichia coli/antagonistas & inhibidores , Histidina/metabolismo , Histona Demetilasas , Humanos , Hidroxilación , Espectroscopía de Resonancia Magnética , Oxigenasas de Función Mixta/antagonistas & inhibidores , Proteínas Nucleares/metabolismo , Oxigenasas/antagonistas & inhibidores , Proteínas Ribosómicas/metabolismoRESUMEN
This paper reports a versatile nano-sensor technology using "top-down" poly-silicon nanowire field-effect transistors (FETs) in the conventional Complementary Metal-Oxide Semiconductor (CMOS)-compatible semiconductor process. The nanowire manufacturing technique reduced nanowire width scaling to 50 nm without use of extra lithography equipment, and exhibited superior device uniformity. These n type polysilicon nanowire FETs have positive pH sensitivity (100 mV/pH) and sensitive deoxyribonucleic acid (DNA) detection ability (100 pM) at normal system operation voltages. Specially designed oxide-nitride-oxide buried oxide nanowire realizes an electrically V(th)-adjustable sensor to compensate device variation. These nanowire FETs also enable non-volatile memory application for a large and steady V(th) adjustment window (>2 V Programming/Erasing window). The CMOS-compatible manufacturing technique of polysilicon nanowire FETs offers a possible solution for commercial System-on-Chip biosensor application, which enables portable physiology monitoring and in situ recording.
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Nanocables , Semiconductores , Silicio/química , ADN/análisis , Concentración de Iones de Hidrógeno , Microscopía Electrónica de RastreoRESUMEN
This research is to investigate the effects of bonding technology and thinning process on the electrical properties of 0.35 microm technology node n-MOSFET devices. After the bonding process, by changing the bonding temperature up to 400 degrees C and bonding force up to 2.5 x 10(5) Pa, these devices still have the same electrical performances. In addition, thinning process was applied to investigate the stress which would affect the electrical properties of n-MOSFETs. The electrical performances of devices do not change for substrate thickness larger than 466 microm.
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There are more than 100 different ribonucleoside structures incorporated as post-transcriptional modifications, mainly in tRNA and rRNA of both prokaryotes and eukaryotes, and emerging evidence suggests that these modifications function as a system in the translational control of cellular responses. However, our understanding of this system is hampered by the paucity of information about the complete set of RNA modifications present in individual organisms. To this end, we have employed a chromatography-coupled mass spectrometric approach to define the spectrum of modified ribonucleosides in microbial species, starting with Mycobacterium bovis BCG. This approach revealed a variety of ribonucleoside candidates in tRNA from BCG, of which 12 were definitively identified based on comparisons to synthetic standards and 5 were tentatively identified by exact mass comparisons to RNA modification databases. Among the ribonucleosides observed in BCG tRNA was one not previously described in tRNA, which we have now characterized as N6,N6-dimethyladenosine.
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Adenosina/análogos & derivados , Adenosina/química , Mycobacterium bovis/química , ARN de Transferencia/química , Animales , Humanos , Espectrometría de Masas , Mycobacterium bovis/genética , ARN de Transferencia/aislamiento & purificación , Ratas , Levaduras/genéticaRESUMEN
The facile synthesis of a novel electron-precise paramagnetic hexamanganese carbonyl selenide cluster [Se(6)Mn(6)(CO)(18)](4-) (1) was discovered, which demonstrates contrasting reactivity toward O(2) and Se(8) under markedly mild conditions to afford the O- and Se-inserted clusters [Se(6)Mn(6)(CO)(18)(O)](4-) (2) and [Se(10)Mn(6)(CO)(18)](4-) (3), respectively. Clusters 1-3 represent the first examples of electron-precise paramagnetic main-group transition metal carbonyl clusters, and their formation and bonding properties are further elucidated by theoretical calculations.
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Complejos de Coordinación/química , Manganeso/química , Oxígeno/química , Selenio/química , Electrones , Modelos Moleculares , Estructura MolecularRESUMEN
When the tellurium-capped tri-iron carbonyl cluster [Et(4)N](2)[TeFe(3)(CO)(9)] was treated with 1 equiv of CuX in THF at 0 degrees C, CuX-incorporated clusters [Et(4)N](2)[TeFe(3)(CO)(9)CuX] (X = Cl, [Et(4)N](2)[1a]; Br, [Et(4)N](2)[1b]; I, [Et(4)N](2)[1c]) were formed, respectively. X-ray analysis showed that 1a-1c each exhibited a TeFe(3) core with one Fe-Fe bond bridged by one CuX fragment. When the reactions were carried out at a molar ratio of 1:2 (X = Cl, Br) or 1:3 (X = I) in tetrahydrofuran (THF) or MeCN at 0 degrees C, Cu(2)X(2)-incorporated clusters [Et(4)N](2)[TeFe(3)(CO)(9)Cu(2)X(2)] (X = Cl, [Et(4)N](2)[2a]; Br, [Et(4)N](2)[2b]; I, [Et(4)N](2)[2c]) were obtained, respectively. Cluster 2a was structurally characterized by X-ray analysis to display a TeFe(3) core, in which one TeFe(2) plane was asymmetrically bridged and capped by one mu(3)-CuCl and another mu(4)-CuCl with two Cu atoms bonded. Complexes 1a-1c underwent skeleton expansion to form Cu(3)X-incorporated di-TeFe(3) clusters [{TeFe(3)(CO)(9)}(2)Cu(3)X](2-) (X = Cl, 3a; Br, 3b; I, 3c), respectively, upon treatment with 1 equiv of [Cu(MeCN)(4)][BF(4)] at 0 degrees C. X-ray analysis showed that 3b and 3c each consisted of two TeFe(3) clusters that were linked by a Cu(3)X moiety. However, a similar reaction for 1a and 1b with 1 equiv of [Cu(MeCN)(4)][BF(4)] at room temperature produced Cu(4)X(2)-linked di-TeFe(3) clusters [{TeFe(3)(CO)(9)}(2)Cu(4)X(2)](2-) (X = Cl, 4a; Br, 4b). Cluster 4a was shown by X-ray analysis to have two TeFe(3) cores linked by a Cu(4)Cl(2) moiety. Clusters 4a and 4b were also produced directly from the reaction of [Et(4)N](2)[TeFe(3)(CO)(9)] with 4 equiv of CuX (X = Cl, Br) in THF. Furthermore, the nature, the formation, the cluster transformation, and the electrochemistry of the CuX-incorporated mono- or di-TeFe(3) clusters are explained in terms of the effects of tellurium, copper halide, and the size of the metal skeleton, all of which are elucidated by molecular calculations at the B3LYP level of density functional theory.
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The unprecedented ternary Te-Fe-Cu chain polymers [{Et4N}{TeFe3(CO)9Cu}]infinity and [{TeFe3(CO)9Cu2}(mu-4,4'-dipyridyl)1.5]infinity were prepared from the self-assembly of [Et4N]2[TeFe3(CO)9] with [Cu(MeCN)4][BF4] in THF or in the presence of 4,4'-dipyridyl in THF. These two chain polymers, which can also be constructed from the precursor complex TeFe3(CO)9Cu2(MeCN)2, show semiconducting behaviors with low band gaps of 0.59 and 0.41 eV, respectively. In addition, their conductivity and the effect of the bridging ligand are further elucidated by theoretical calculations.
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Cobre/química , Hierro/química , Compuestos Organometálicos/química , Polímeros/química , Semiconductores , Telurio/química , Simulación por Computador , Cristalografía por Rayos X , Modelos Químicos , Modelos Moleculares , Estructura MolecularRESUMEN
Hepatitis C virus (HCV) is a serious global problem, and present therapeutics are inadequate to cure HCV infection. In the present study, various antiviral assays show that As2O3 at submicromolar concentrations is capable of inhibiting HCV replication. The 50% effective concentration (EC50) of As2O3 required to inhibit HCV replication was 0.35 microM when it was determined by a reporter-based HCV replication assay, and the EC50 was below 0.2 microM when it was determined by quantitative reverse transcription-PCR analysis. As2O3 did not cause cellular toxicity at this concentration, as revealed by an MTS [3-(4,5-dimethylthiozol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] assay. A combination of As2O3 and alpha interferon exerted synergistic effects against HCV, as revealed by a multiple linear logistic model and isobologram analysis. Furthermore, in an alternative HCV antiviral system that may recapitulate additional steps involved in HCV infection and replication, As2O3 at 0.3 microM totally abolished the HCV signal, whereas alpha interferon at a high dose (5,000 IU/ml) only partially suppressed the HCV signal. The study highlights the indications for use of a novel class of anti-HCV agent. Further elucidation of the exact antiviral mechanism of As2O3 may lead to the development of agents with potent activities against HCV or related viruses.
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Antivirales , Arsenicales/farmacología , Hepacivirus/efectos de los fármacos , Óxidos/farmacología , Replicación Viral/efectos de los fármacos , Trióxido de Arsénico , Northern Blotting , Western Blotting , Línea Celular , Evaluación Preclínica de Medicamentos , Sinergismo Farmacológico , Genes Reporteros , Hepacivirus/fisiología , Humanos , Interferón-alfa/farmacología , ARN Viral/análisis , ARN Viral/biosíntesis , Replicón/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The rare examples of electron-rich mixed-metal carbonyl telluride and selenide clusters [E(2)Cr(2)Fe(CO)(10)](2-) (E = Te, Se) have been demonstrated. These two novel carbonyl complexes exhibit the unusual paramagnetic behavior.