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The ladybug, Cryptolaemus montrouzieri (Mulsant) (Coleoptera: Cocccinellidae)(Mulsant)(Coleoptera: Cocccinellidae), is a highly efficient predator in controlling mealybug populations and is considered an effective agent for controlling the papaya mealybugs (Paracoccus marginatus) (Williams & Granara de Willink) (Hemiptera: Pseudococcidae). Various criteria have been proposed for evaluating predator effectiveness, with the consumption rate of prey by individual predators, specifically the functional response, emerging as a common and crucial metric. This study evaluated the functional responses of third- and fourth-instar larvae, as well as male and female adults (<48 h old) of C. montrouzieri to adult females of P. marginatus at 3 different temperatures (22 °C, 28 °C, and 35 °C) with 70%â ±â 5% RH and a 12L:12D h photoperiod. Prey densities were 2, 4, 8, 16, 32, 45, or 60 papaya mealybugs per predator for all tests. The response to prey density by third- and fourth-instar larvae or both sexes of adult C. montrouzieri was a type II at all temperatures. The highest attack rate and lowest handling time were estimated at 28 °C in males and 35 °C in females, respectively. The highest daily prey consumption rate occurred at 35 °C in both the immature and adult stages of C. montrouzieri. These findings support the potential of C. montrouzieri in controlling the papaya mealybug, especially in tropical and subtropical regions, given its search efficiency at high temperatures tested in this study. However, additional field investigations are needed to ascertain the control efficacy of C. montrouzieri for this mealybug in biocontrol programs.
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Escarabajos , Hemípteros , Larva , Control Biológico de Vectores , Conducta Predatoria , Temperatura , Animales , Escarabajos/fisiología , Hemípteros/fisiología , Femenino , Masculino , Larva/fisiología , Larva/crecimiento & desarrollo , Cadena AlimentariaRESUMEN
Appropriate fibrosis is required to prevent subsequent adverse remodeling and heart failure post myocardial infarction (MI), and cardiac fibroblasts (CFs) play a critical role during the process. Carbonic anhydrase 3 (CAR3) is an important mediator in multiple biological processes besides its CO2 hydration activity; however, the role and underlying mechanism of CAR3 on cardiac repair post MI injury remains unknown. Here, we found that CAR3 expression was up-regulated in cardiac tissue in infarct area at the reparative phase of MI, with a peak at 7 days post MI. The upregulation was detected mainly on fibroblast instead of cardiomyocyte, and primary cardiac fibroblasts treated with TGF-ß1 recaptured our observation. While CAR3 deficiency leads to weakened collagen density, enlarged infarct size and aggravated cardiac dysfunction post-MI. In fibroblast, we observed that CAR3 deficiency restrains collagen synthesis, cell migration and gel contraction of cardiac fibroblasts, whereas overexpression of CAR3 in CFs improves wound healing and cardiac fibroblast activation. Mechanistically, CAR3 stabilizes Smad7 protein via modulating its acetylation, which dampens phosphorylation of Smad2 and Smad3, thus inhibiting fibroblast transformation. In contrast, inhibition of Smad7 acetylation with C646 blunts CAR3 deficiency induced suppression of fibroblast activation and impaired cardiac healing. Our data demonstrate a protective role of CAR3 in cardiac wound repair post MI via promoting fibroblasts activation through Smad7-TGF-ß/Smad2/3 signaling pathway.
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Anhidrasas Carbónicas , Infarto del Miocardio , Humanos , Miocardio/metabolismo , Proteína smad7/metabolismo , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Transducción de Señal/genética , Miocitos Cardíacos/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Colágeno/metabolismo , Anhidrasas Carbónicas/metabolismo , Fibroblastos/metabolismoRESUMEN
We report a combined manual annotation and deep-learning natural language processing study to make accurate entity extraction in hereditary disease related biomedical literature. A total of 400 full articles were manually annotated based on published guidelines by experienced genetic interpreters at Beijing Genomics Institute (BGI). The performance of our manual annotations was assessed by comparing our re-annotated results with those publicly available. The overall Jaccard index was calculated to be 0.866 for the four entity types-gene, variant, disease and species. Both a BERT-based large name entity recognition (NER) model and a DistilBERT-based simplified NER model were trained, validated and tested, respectively. Due to the limited manually annotated corpus, Such NER models were fine-tuned with two phases. The F1-scores of BERT-based NER for gene, variant, disease and species are 97.28%, 93.52%, 92.54% and 95.76%, respectively, while those of DistilBERT-based NER are 95.14%, 86.26%, 91.37% and 89.92%, respectively. Most importantly, the entity type of variant has been extracted by a large language model for the first time and a comparable F1-score with the state-of-the-art variant extraction model tmVar has been achieved.
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Aprendizaje Profundo , Procesamiento de Lenguaje Natural , Humanos , Enfermedades Genéticas Congénitas/genética , Publicaciones , Minería de Datos/métodosRESUMEN
BACKGROUND: Sepsis and its associated heart failure are among the leading causes of death. Gramine, a natural indole alkaloid, can be extracted from a wide variety of raw plants, and it exhibits therapeutic potential in pathological cardiac hypertrophy. However, the effect of gramine on inflammatory cardiomyopathy, particularly sepsis-induced myocardial injury, remains an unexplored area. PURPOSE: To determine the role of gramine in sepsis-induced myocardial dysfunction and explore its underlying mechanism. STUDY DESIGN AND METHODS: In mice, sepsis was established by intraperitoneally injecting lipopolysaccharide (LPS, 10 mg/kg). Subsequently, the effects of gramine administration (50 or 100 mg/kg) on LPS-triggered cardiac dysfunction in mice were investigated. For in vitro studies, isolated primary cardiomyocytes were used to assess the effect of gramine (25 or 50 µM) on LPS-induced apoptosis and inflammation. Additionally, molecular docking, co-immunoprecipitation and ubiquitination analyzes were conducted to explore the underlying mechanisms. RESULTS: Gramine visibly ameliorated sepsis-induced cardiac dysfunction, inflammatory response, and mortality in vivo. Moreover, it significantly alleviated LPS-induced apoptotic and inflammatory responses in vitro. Furthermore, target prediction for gramine using the SuperPred website indicated that the nuclear factor NF-κB p105 subunit was one of the molecules ranked in priority order with a high model accuracy and a high probability score. Molecular docking studies demonstrated that gramine effectively docked to the death domain of NF-κB p105. Mechanistic studies revealed that gramine suppressed the processing of NF-κB p105 to p50 by inhibiting NF-κB p105 ubiquitination. Additionally, the protective effect of gramine on cardiac injury was almost abolished by overexpressing NF-κB p105. CONCLUSION: Gramine is a promising bioactive small molecule for treating sepsis-induced myocardial dysfunction, which acts by docking to NF-κB p105 and inhibiting NF-κB p105 ubiquitination, thus preventing its processing to NF-κB p50. Therefore, gramine holds potential as a clinical drug for treating myocardial depression during sepsis.
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Cardiomiopatías , Cardiopatías , Sepsis , Animales , Ratones , FN-kappa B/metabolismo , Lipopolisacáridos , Simulación del Acoplamiento Molecular , Alcaloides Indólicos , Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/etiología , Ubiquitinación , Sepsis/complicaciones , Sepsis/tratamiento farmacológico , Sepsis/metabolismoRESUMEN
Heart sound detection technology plays an important role in the prediction of cardiovascular disease, but the most significant heart sounds are fleeting and may be imperceptible. Hence, obtaining heart sound information in an efficient and accurate manner will be helpful for the prediction and diagnosis of heart disease. To obtain heart sound information, we designed an audio data analysis tool to segment the heart sounds from single heart cycle, and validated the heart rate using a finger oxygen meter. The results from our validated technique could be used to realize heart sound segmentation. Our robust algorithmic platform was able to segment the heart sounds, which could then be compared in terms of their difference from the background. A combination of an electronic stethoscope and artificial intelligence technology was used for the digital collection of heart sounds and the intelligent identification of the first (S1) and second (S2) heart sounds. Our approach can provide an objective basis for the auscultation of heart sounds and visual display of heart sounds and murmurs.
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OBJECTIVE: This study examined whether the immunomodulator fingolimod (FTY720) could alleviate renal ischemia/reperfusion (I/R)-induced lung injury and explored the potential mechanisms. METHODS: Renal I/R was established in a rat model, and FTY720 (0.5, 1, or 2 mg/kg) was injected intraperitoneally after 15 minutes of ischemia. Pro-inflammatory cytokine levels, oxidative stress, apoptosis, and the mRNA expression of the sphingosine-1-phosphate (S1P)-related signaling pathway genes sphingosine kinase-1 (SphK1) and sphingosine kinase-2 were analyzed in lung tissue. RESULTS: Increased pro-inflammatory cytokine levels; decreased total superoxide dismutase, catalase, and glutathione peroxidase levels; increased apoptosis; and increased S1P lyase and SphK1 expression were observed following renal I/R. FTY720 reversed renal I/R-induced changes and effectively attenuated lung injury. CONCLUSION: FTY720 protected against acute lung injury in rats subjected to renal I/R by decreasing pulmonary inflammation and apoptosis, increasing oxidative stress, and modulating S1P metabolism.
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Lesión Pulmonar Aguda , Daño por Reperfusión , Animales , Apoptosis , Clorhidrato de Fingolimod/farmacología , Inflamación/tratamiento farmacológico , Isquemia , Lisofosfolípidos , Ratas , Reperfusión , Daño por Reperfusión/tratamiento farmacológico , EsfingosinaRESUMEN
OBJECTIVE: To observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on venous thrombosis and quality of life after lung cancer surgery, basing on the conventional nursing and early functional exercise. METHODS: A total of 120 patients diagnosed as non-small cell lung cancer (NSCLC) and received radical resection of lung cancer surgery for the first time were randomized into a conventional nursing group, a rehabilitation training group and a TEAS group, 40 cases in each group. Conventional nursing was adopted in the conventional nursing group. Conventional nursing combined with early functional exercise were adopted in the rehabilitation training group, the exercise was taken 20 min each time, once in both morning and afternoon for 5 days. On the basis of the treatment in the rehabilitation training group, TEAS was applied at Zusanli (ST 36), Xuehai (SP 10), Sanyinjiao (SP 6), etc. in the TEAS group, with disperse-dense wave in frequency of 30 Hz/100 Hz and tolerable intensity, 30 min each time, once in both morning and afternoon for 5 days. The incidence of venous thrombosis in each group was observed at the 5th day after surgery. Before surgery and at the 5th day after surgery, the Caprini thrombus risk assessment was performed, the Karnofsky performance status (KPS) scale and the functional assessment of cancer therapy-lung (FACT-L) were used to evaluate the quality of life. RESULTS: At the 5th day after surgery, no thrombosis was found in the TEAS group, the incidence of venous thrombosis in the TEAS group was lower than 15.0% (6/40) in the conventional nursing group (P<0.05). At the 5th day after surgery, the Caprini scores were increased in the 3 groups (P<0.01), while that in the TEAS group was lower than the conventional nursing group (P<0.05); the KPS scores were decreased in the 3 groups (P<0.01), while those in the TEAS group and the rehabilitation training group were higher than the conventional nursing group (P<0.01, P<0.05); the total scores and the subitem scores of FACT-L were decreased in the 3 groups (P<0.05), while the total score of FACT-L and the subitem score of lung cancer specificity in the TEAS group were higher than those in the conventional nursing group (P<0.05). CONCLUSION: On the basis of the conventional nursing and early functional exercise, TEAS can reduce the incidence of venous thrombosis, effectively prevent thrombosis and improve quality of life.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Estimulación Eléctrica Transcutánea del Nervio , Trombosis de la Vena , Puntos de Acupuntura , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Humanos , Neoplasias Pulmonares/cirugía , Calidad de Vida , Trombosis de la Vena/etiologíaRESUMEN
OBJECTIVE@#To observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on venous thrombosis and quality of life after lung cancer surgery, basing on the conventional nursing and early functional exercise.@*METHODS@#A total of 120 patients diagnosed as non-small cell lung cancer (NSCLC) and received radical resection of lung cancer surgery for the first time were randomized into a conventional nursing group, a rehabilitation training group and a TEAS group, 40 cases in each group. Conventional nursing was adopted in the conventional nursing group. Conventional nursing combined with early functional exercise were adopted in the rehabilitation training group, the exercise was taken 20 min each time, once in both morning and afternoon for 5 days. On the basis of the treatment in the rehabilitation training group, TEAS was applied at Zusanli (ST 36), Xuehai (SP 10), Sanyinjiao (SP 6), etc. in the TEAS group, with disperse-dense wave in frequency of 30 Hz/100 Hz and tolerable intensity, 30 min each time, once in both morning and afternoon for 5 days. The incidence of venous thrombosis in each group was observed at the 5th day after surgery. Before surgery and at the 5th day after surgery, the Caprini thrombus risk assessment was performed, the Karnofsky performance status (KPS) scale and the functional assessment of cancer therapy-lung (FACT-L) were used to evaluate the quality of life.@*RESULTS@#At the 5th day after surgery, no thrombosis was found in the TEAS group, the incidence of venous thrombosis in the TEAS group was lower than 15.0% (6/40) in the conventional nursing group (@*CONCLUSION@#On the basis of the conventional nursing and early functional exercise, TEAS can reduce the incidence of venous thrombosis, effectively prevent thrombosis and improve quality of life.
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Humanos , Puntos de Acupuntura , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Neoplasias Pulmonares/cirugía , Calidad de Vida , Estimulación Eléctrica Transcutánea del Nervio , Trombosis de la Vena/etiologíaRESUMEN
Sea spray aerosols contain a large array of organic compounds that contribute to high viscosities at low relative humidity and temperature thereby slowing translational diffusion of water. The Stokes-Einstein equation describes how viscosity is inversely correlated with the translational diffusion coefficient of the diffusing species. However, recent studies indicate that the Stokes-Einstein equation breaks down at high viscosities achieved in the particle phase (>1012 Pa s), underestimating the predicted water diffusion coefficient by orders of magnitude and revealing the need for directly studying the diffusion of water in single aerosols. A new method is reported for measuring the water diffusion coefficient in single suspended charged sucrose-water and citric acid (CA)-water microdroplets in the 30-60 micron diameter range. The translational water diffusion coefficient is quantified using the H2O/D2O isotope exchange technique between 26 and 54% relative humidity (RH) for sucrose and 7 and 25% RH for CA using a recently developed mobile electrodynamic balance apparatus. The results are in good agreement with the literature, particularly the Vignes-type parameterization from experiments using isotope exchange and optical tweezers. Below 15% RH, CA droplets show incomplete H2O/D2O exchange. This mobile electrodynamic balance will allow future studies of atmospherically relevant chemical systems, including field studies.
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This corrects the article DOI: 10.1038/ncomms3223.
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AIM: The aim of this study was to compare the efficacy and adverse effects of radioiodine (131I) therapy between two groups of patients with low-risk differentiated thyroid cancer (DTC) who received 30 mCi or 100 mCi radioiodine for ablation of the thyroid remnant after total thyroidectomy. METHODS: The study cohort was 173 patients, 85 of whom were given 30 mCi of radioiodine and the others were given 100 mCi of radioiodine. Follow-up involved neck ultrasonography, measurement of serum levels of thyroglobulin and whole-body scans to evaluate the response of radioiodine treatment. All patients were assessed for adverse effects. RESULTS: Of the 173 patients, 170 (98.3%) patients finally achieved successful ablation. The prevalence of successful ablation was 77.6% in the low-dose group versus 71.5% in the high-dose group after the first dose administration (P=0.36), 79% in the low-dose group versus 88% in the high-dose group after the second dose administration (P=0.416), and 97.6% in the low-dose group versus 98.9% in the high-dose group after the final ablation (P=0.54). We found no significant differences between the two groups. No patient had an adverse effect with a severity grade ⩾2 and the prevalence of adverse effects in the high-dose group was higher than that in the low-dose group, especially for nausea, neck pain, and sore throat. CONCLUSION: These data suggest that a low dose of radioiodine is as effective as a high dose of radioiodine for ablation of the thyroid remnant after total thyroidectomy for low-risk DTC. Moreover, low-dose radioiodine therapy is associated with a lower prevalence of adverse events.
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We report a photoelectron imaging and photodetachment study of cryogenically cooled 3-hydroxyphenoxide (3HOP) anions, m-HO(C6H4)O-. In a previous preliminary study, two conformations of the cold 3HOP anions with different dipole bound states were observed [D. L. Huang et al., J. Phys. Chem. Lett. 6, 2153 (2015)]. Five near-threshold vibrational resonances were revealed in the photodetachment spectrum from the dipole-bound excited states of the two conformations. Here, we report a more extensive investigation of the two conformers with observation of thirty above-threshold vibrational resonances in a wide spectral range between 18 850 and 19 920 cm-1 (â¼1000 cm-1 above the detachment thresholds). By tuning the detachment laser to the vibrational resonances in the photodetachment spectrum, high-resolution conformation-selective resonant photoelectron images are obtained. Using information of the autodetachment channels and theoretical vibrational frequencies, we are able to assign the resonant peaks in the photodetachment spectrum: seventeen are assigned to vibrational levels of anti-3HOP, eight to syn-3HOP, and five to overlapping vibrational levels of both conformers. From the photodetachment spectrum and the conformation-selective resonant photoelectron spectra, we have obtained fourteen fundamental vibrational frequencies for the neutral syn- and anti-m-HO(C6H4)Oâ radicals. The possibility to produce conformation-selected neutral beams using resonant photodetachment via dipole-bound excited states of anions is discussed.
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Time-resolved pump-probe photoelectron spectroscopy has been used to study the relaxation dynamics of gaseous [Pt2(µ-P2O5H2)4 + 2H](2-) after population of its first singlet excited state by 388 nm femtosecond laser irradiation. In contrast to the fluorescence and phosphorescence observed in condensed phase, a significant fraction of the photoexcited isolated dianions decays by electron loss to form the corresponding monoanions. Our transient photoelectron data reveal an ultrafast decay of the initially excited singlet (1)A2u state and concomitant rise in population of the triplet (3)A2u state, via sub-picosecond intersystem crossing (ISC). We find that both of the electronically excited states are metastably bound behind a repulsive Coulomb barrier and can decay via delayed autodetachment to yield electrons with characteristic kinetic energies. While excited state tunneling detachment (ESETD) from the singlet (1)A2u state takes only a few picoseconds, ESETD from the triplet (3)A2u state is much slower and proceeds on a time scale of hundreds of nanoseconds. The ISC rate in the gas phase is significantly higher than in solution, which can be rationalized in terms of changes to the energy dissipation mechanism in the absence of solvent molecules. [Pt2(µ-P2O5H2)4 + 2H](2-) is the first example of a photoexcited multianion for which ESETD has been observed following ISC.
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We report a joint photoelectron spectroscopy and theoretical investigation of the gaseous Au2I3- cluster, which is found to exhibit two types of isomers due to competition between Au-I covalent bonding and Au-Au aurophilic interactions. The covalent bonding favors a bent IAuIAuI- structure with an obtuse Au-I-Au angle (100.7°), while aurophilic interactions pull the two Au atoms much closer, leading to an acutely bent structure (72.0°) with an Au-Au distance of 3.08 Å. The two isomers are separated by a small barrier and are nearly degenerate with the obtuse isomer being slightly more stable. At low temperature, only the obtuse isomer is observed; distinct experimental evidence is observed for the co-existence of a combination of isomers with both acute and obtuse bending angles at room temperature. The two bond-bending isomers of Au2I3- reveal a unique example of one molecule being able to oscillate between different structures as a result of two competing chemical forces.
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Molecular conformation is important in chemistry and biochemistry. Conformers connected by low energy barriers can only be observed at low temperatures and are difficult to be separated. Here we report a new method to obtain conformation-selective spectroscopic information about dipolar molecular radicals via dipole-bound excited states of the corresponding anions cooled in a cryogenic ion trap. We observed two conformers of cold 3-hydroxyphenoxide anions [m-HO(C6H4)O(-)] in high-resolution photoelectron spectroscopy and measured different electron affinities, 18,850(8) and 18,917(5) cm(-1), for the syn and anti 3-hydroxyphenoxy radicals, respectively. We also observed dipole-bound excited states for m-HO(C6H4)O(-) with different binding energies for the two conformers due to the different dipole moments of the corresponding 3-hydroxyphenoxy radicals. Excitations to selected vibrational levels of the dipole-bound states result in conformation-selective photoelectron spectra. This method should be applicable to conformation-selective spectroscopic studies of any anions with dipolar neutral cores.
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Espectroscopía de Fotoelectrones , Resorcinoles/química , Aniones/química , Electrones , Radicales Libres/química , Conformación Molecular , TermodinámicaRESUMEN
Vibrational state-selective resonant two-photon photoelectron spectra have been obtained via a triplet intermediate state ((3)Σ(-)) of AuS(-) near its detachment threshold using high-resolution photoelectron imaging of cryogenically cooled AuS(-) anions. Four vibrational levels of the (3)Σ(-) excited state are observed to be below the detachment threshold. Resonant two-photon absorptions through these levels yield vibrational state-selective photoelectron spectra to the (2)Σ final state of neutral AuS with broad and drastically different Franck-Condon distributions, reflecting the symmetries of the vibrational wave functions of the (3)Σ(-) intermediate state. The (3)Σ(-) excited state is spin-forbidden from the (1)Σ(+) ground state of AuS(-) and is accessed due to strong relativistic effects. The nature of the (3)Σ(-) excited state is confirmed by angular distributions of the photoelectron images and quantum calculations.
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Uranium chlorides are important in actinide chemistry and nuclear industries, but their chemical bonding and many physical and chemical properties are not well understood yet. Here, we report the first experimental observation of two gaseous uranium hexachloride anions, UCl6 (-) and UCl6 (2-), which are probed by photoelectron spectroscopy in conjunction with quantum chemistry calculations. The electron affinity of UCl6 is measured for the first time as +5.3 eV; its second electron affinity is measured to be +0.60 eV from the photoelectron spectra of UCl6 (2-). We observe that the detachment cross sections of the 5f electrons are extremely weak in the visible and UV energy ranges. It is found that the one-electron one-determinental molecular orbital picture and Koopmans' theorem break down for the strongly internally correlated U-5f(2) valence shell of tetravalent U(+4) in UCl6 (2-). The calculated adiabatic and vertical electron detachment energies from ab initio calculations agree well with the experimental observations. Electronic structure and chemical bonding in the uranium hexachloride species UCl6 (2-) to UCl6 are discussed as a function of the oxidation state of U.
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We report a photodetachment and high-resolution photoelectron imaging study of cold 2-hydroxyphenoxide anion, o - HO(C6H4)O(-), cooled in a cryogenic ion trap. Photodetachment spectroscopy revealed a dipole-bound state (DBS) of the anion, 25 ± 5 cm(-1), below the detachment threshold of 18 784 ± 5 cm−1 (2.3289 ± 0.0006 eV), i.e., the electron affinity of the 2-hydroxyphenoxy radical o - HO(C6H4)O(â ). Twenty-two vibrational levels of the DBS are observed as resonances in the photodetachment spectrum. By tuning the detachment laser to these DBS vibrational levels, we obtain 22 high-resolution resonant photoelectron spectra, which are highly non-Franck-Condon due to mode-selective autodetachment and the Δv = - 1 propensity rule. Numerous Franck-Condon inactive vibrational modes are observed in the resonant photoelectron spectra, significantly expanding the vibrational information that is available in traditional high-resolution photoelectron spectroscopy. A total of 15 fundamental vibrational frequencies are obtained for the o - HO(C6H4)O(â ) radical from both the photodetachment spectrum and the resonant photoelectron spectra, including six symmetry-forbidden out-of-plane modes as a result of resonant enhancement.
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We report the observation of a dipole-bound state and a high-resolution photoelectron imaging study of cryogenically cooled acetate anions (CH3COO(-)). Both high-resolution non-resonant and resonant photoelectron spectra via the dipole-bound state of CH3COO(-) are obtained. The binding energy of the dipole-bound state relative to the detachment threshold is determined to be 53 ± 8 cm(-1). The electron affinity of the CH3COO· neutral radical is measured accurately as 26 236 ± 8 cm(-1) (3.2528 ± 0.0010 eV) using high-resolution photoelectron imaging. This accurate electron affinity is validated by observation of autodetachment from two vibrational levels of the dipole-bound state of CH3COO(-). Excitation spectra to the dipole-bound states yield rotational profiles, allowing the rotational temperature of the trapped CH3COO(-) anions to be evaluated.
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Deprotonated thymine can exist in two different forms, depending on which of its two N sites is deprotonated: N1[T-H]- or N3[T-H]-. Here we report a photodetachment study of the N1[T-H]- isomer cooled in a cryogenic ion trap and the observation of an excited dipole-bound state. Eighteen vibrational levels of the dipole-bound state are observed, and its vibrational ground state is found to be 238 ± 5 cm-1 below the detachment threshold of N1[T-H]-. The electron affinity of the deprotonated thymine radical (N1[T-H]Ë) is measured accurately to be 26 322 ± 5 cm-1 (3.2635 ± 0.0006 eV). By tuning the detachment laser to the sixteen vibrational levels of the dipole-bound state that are above the detachment threshold, highly non-Franck-Condon resonant-enhanced photoelectron spectra are obtained due to state- and mode-selective vibrational autodetachment. Much richer vibrational information is obtained for the deprotonated thymine radical from the photodetachment and resonant-enhanced photoelectron spectroscopy. Eleven fundamental vibrational frequencies in the low-frequency regime are obtained for the N1[T-H]Ë radical, including the two lowest-frequency internal rotational modes of the methyl group at 70 ± 8 cm-1 and 92 ± 5 cm-1.