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The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.
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The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.
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Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts1-3. Recent observations of a Galactic FRB4-8 suggest that at least some FRBs originate from magnetars, but the origin of cosmological FRBs is still not settled. Here we report the detection of 1,863 bursts in 82 h over 54 days from the repeating source FRB 20201124A (ref. 9). These observations show irregular short-time variation of the Faraday rotation measure (RM), which scrutinizes the density-weighted line-of-sight magnetic field strength, of individual bursts during the first 36 days, followed by a constant RM. We detected circular polarization in more than half of the burst sample, including one burst reaching a high fractional circular polarization of 75%. Oscillations in fractional linear and circular polarizations, as well as polarization angle as a function of wavelength, were detected. All of these features provide evidence for a complicated, dynamically evolving, magnetized immediate environment within about an astronomical unit (AU; Earth-Sun distance) of the source. Our optical observations of its Milky-Way-sized, metal-rich host galaxy10-12 show a barred spiral, with the FRB source residing in a low-stellar-density interarm region at an intermediate galactocentric distance. This environment is inconsistent with a young magnetar engine formed during an extreme explosion of a massive star that resulted in a long gamma-ray burst or superluminous supernova.
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It is difficult to establish the properties of massive stars that explode as supernovae. The electromagnetic emission during the first minutes to hours after the emergence of the shock from the stellar surface conveys important information about the final evolution and structure of the exploding star. However, the unpredictable nature of supernova events hinders the detection of this brief initial phase. Here we report the serendipitous discovery of a newly born, normal type IIb supernova (SN 2016gkg), which reveals a rapid brightening at optical wavelengths of about 40 magnitudes per day. The very frequent sampling of the observations allowed us to study in detail the outermost structure of the progenitor of the supernova and the physics of the emergence of the shock. We develop hydrodynamical models of the explosion that naturally account for the complete evolution of the supernova over distinct phases regulated by different physical processes. This result suggests that it is appropriate to decouple the treatment of the shock propagation from the unknown mechanism that triggers the explosion.
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Despite common comorbidity of sexual and urinary dysfunctions, the interrelationships between the neural control of these functions are poorly understood. The medullary reticular formation (MRF) contributes to both mating/arousal functions and micturition, making it a good site to test circuitry interactions. Urethane-anesthetized adult Wistar rats were used to examine the impact of electrically stimulating different nerve targets [dorsal nerve of the penis (DNP) or clitoris (DNC); L6/S1 trunk] on responses of individual extracellularly recorded MRF neurons. The effect of bladder filling on MRF neurons was also examined, as was stimulation of DNP on bladder reflexes via cystometry. In total, 236 MRF neurons responded to neurostimulation: 102 to DNP stimulation (12 males), 64 to DNC stimulation (12 females), and 70 to L6/S1 trunk stimulation (12 males). Amplitude thresholds were significantly different at DNP (15.0 ± 0.6 µA), DNC (10.5 ± 0.7 µA), and L6/S1 trunk (54.2 ± 4.6 µA), whereas similar frequency responses were found (max responses near 30-40 Hz). In five males, filling/voiding cycles were lengthened with DNP stimulation (11.0 ± 0.9 µA), with a maximal effective frequency plateau beginning at 30 Hz. Bladder effects lasted ≈ 2 min after DNP stimulus offset. Many MRF neurons receiving DNP/DNC input responded to bladder filling (35.0% and 68.3%, respectively), either just before (43%) or simultaneously with (57%) the voiding reflex. Taken together, MRF-evoked responses with neurostimulation of multiple nerve targets along with different responses to bladder infusion have implications for the role of MRF in multiple aspects of urogenital functions.
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Rede Nervosa/fisiologia , Neurônios/fisiologia , Formação Reticular/fisiologia , Bexiga Urinária/fisiologia , Animais , Clitóris/inervação , Potencial Evocado Motor , Feminino , Masculino , Pênis/inervação , Nervos Periféricos/fisiologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Reflexo , Formação Reticular/citologia , Caracteres Sexuais , Bexiga Urinária/inervaçãoRESUMO
Blastomeres of the pre-implantation mouse embryo form trophectoderm and inner cell mass via a process that requires the transcription factors Tead4, Cdx2, Oct4 and Nanog. In mouse morulae cloned by somatic cell nuclear transfer, we observed that the trophectoderm transcription factor Cdx2 is expressed very differently at the protein level compared to time- and stage-matched fertilized counterparts. Protein levels of Cdx2 in cloned embryos appear 'erratic,' i.e. are widely distributed, when plotted as histograms. In contrast to Cdx2, protein levels of the upstream factor Tead4 and of inner cell mass transcription factors Oct4 and Nanog are similar in cloned and fertilized embryos. These observations suggest that trophectoderm formation is initiated but not maintained correctly in cloned mouse morulae, which is consistent with cloned blastocysts' limited implantation and post-implantation success. Because a cell's ability to differentiate is greatly enhanced if it is surrounded by more cells differentiating the same way, a concept designated community effect by Gurdon, we reasoned that the insufficient cell numbers often observed in cloned embryos might lead to premature Cdx2 expression and differentiation of blastomeres into trophectoderm. Therefore, we created larger cloned embryos by aggregating them at the 4-cell stage. Homologous aggregation stimulates expression of multiple signaling pathways' components and results in cloned embryos with levels of Cdx2 similar to fertilized embryos. Most of the resultant morulae and blastocysts consist of cells of all three founders, indicating that aggregation increases stability of all of the individual components. We conclude that the induction of pluripotency in cloned embryos is more efficient than previously assumed, and we propose that a minimum cell number is necessary to stabilize pluripotency and inhibit premature expression of Cdx2 in cloned mouse embryos.
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Linhagem da Célula , Embrião de Mamíferos/metabolismo , Animais , Fator de Transcrição CDX2 , Clonagem de Organismos , Embrião de Mamíferos/citologia , Feminino , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Masculino , Camundongos , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Transativadores/genética , Transativadores/metabolismoRESUMO
Many cardiac pathologies involve changes in tissue structure. Conventional analysis of structural features is extremely time-consuming and subject to observer bias. The possibility to determine spatial interrelations between these features is often not fully exploited. We developed a staining protocol and an ImageJ-based tool (JavaCyte) for automated histological analysis of cardiac structure, including quantification of cardiomyocyte size, overall and endomysial fibrosis, spatial patterns of endomysial fibrosis, fibroblast density, capillary density and capillary size. This automated analysis was compared to manual quantification in several well-characterized goat models of atrial fibrillation (AF). In addition, we tested inter-observer variability in atrial biopsies from the CATCH-ME consortium atrial tissue bank, with patients stratified by their cardiovascular risk profile for structural remodeling. We were able to reproduce previous manually derived histological findings in goat models for AF and AV block (AVB) using JavaCyte. Furthermore, strong correlation was found between manual and automated observations for myocyte count (r = 0.94, p < 0.001), myocyte diameter (r = 0.97, p < 0.001), endomysial fibrosis (r = 0.98, p < 0.001) and capillary count (r = 0.95, p < 0.001) in human biopsies. No significant variation between observers was observed (ICC = 0.89, p < 0.001). We developed and validated an open-source tool for high-throughput, automated histological analysis of cardiac tissue properties. JavaCyte was as accurate as manual measurements, with less inter-observer variability and faster throughput.
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Algoritmos , Fibrilação Atrial/fisiopatologia , Automação , Átrios do Coração/química , Átrios do Coração/fisiopatologia , Idoso , Animais , Feminino , Cabras , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Henoch-Schönlein purpura (HSP) is known to exist in association with a variety of malignant diseases including squamous and small cell lung cancer and hematological malignancies. We report the first cases of HSP associated with carcinoma of the esophagus and adenocarcinoma of the lung, respectively. We compare the main features of our patients with 23 previously published cases. We recommend that patients with HSP, especially men over 40 years of age, should undergo screening for occult neoplasia.
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Adenocarcinoma/complicações , Carcinoma de Células Escamosas/complicações , Neoplasias Esofágicas/complicações , Vasculite por IgA/etiologia , Neoplasias Pulmonares/complicações , Adenocarcinoma/patologia , Biópsia , Carcinoma de Células Escamosas/patologia , Progressão da Doença , Neoplasias Esofágicas/patologia , Evolução Fatal , Humanos , Vasculite por IgA/metabolismo , Vasculite por IgA/patologia , Imunoglobulina A/metabolismo , Rim/metabolismo , Rim/patologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Pele/metabolismo , Pele/patologiaRESUMO
BACKGROUND AND PURPOSE: Hookah smoking is a growing young adult phenomenon, particularly among college students. Many users feel that it is safer than other tobacco products, although its health threats are well documented. Little is known about hookah use rates in community colleges that are attended by nearly half of all US college students. This study examined hookah use in a diverse convenience sample of students attending two southern California community colleges. METHODS: In fall 2011, a cross-sectional, in-classroom survey was administered to 1,207 students. A series of fully adjusted multivariate logistic regressions were conducted to explore demographic, other substance use, and attitudinal correlates of lifetime and current hookah use. RESULTS: Lifetime hookah use (56%) was higher than lifetime cigarette use (49%). Gender and personal socioeconomic status were not related to hookah use. Current use (10.8%) was associated with current use of alcohol, cigars, and cigarettes. Compared to African-Americans, Whites were 2.9 times more likely to be current users, and students who perceive hookah to be more socially acceptable were 21 times more likely to currently use. CONCLUSION: Since hookah use rates are high, colleges should offer health education programs to inform incoming students about the health risks of hookah and cessation programs.
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The elderly tend to be more rigid than younger adults in their attitudes and personalities, and such rigidity is correlated with poor adjustment. However, the rigidity is not the cause of the poor adjustment; rather, it is an attempted solution. One of the patterns of rigidity is an outgrowth of the lifestyle of pessimism, suspicion, self-reliance, self-discipline, determination, and endurance. Two case studies are presented illustrating how rigidity can channel thoughts and prevent the brooding which works itself into depression or anxiety, while simultaneously reinforcing self-help behavior. Geriatric psychotherapy should be problem-centered and should not launch a frontal assault on rigidity or attempt to reconstruct the patient's personality. Behavioral modification, authority, and motivation slogans can be used in conjunction with the rigidity to improve the patient's coping ability.
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Idoso , Personalidade , Psicoterapia , Adaptação Psicológica , Feminino , Humanos , Ajustamento SocialRESUMO
The advance of industrialization in Mexico and elsewhere has brought about psychosocial problems of aging similar to those encountered in the United States. A case study is presented of a 64-year-old Mexican widow who had suicidal thoughts and feeling of uselessness. External constraints on the therapist dictated that psychotherapy be completed within 15 days. A strategy of brief psychotherapy was adopted. The focus was not on establishing transference, probing the unconscious or reconstructing the patient's personality, but on identifying problems and formulating practical solutions promptly. Four hour-long sessions were sufficient to gather information and to counsel the patient and her family. The diagnosis was depression. Treatment centered around increasing the quality of the patient's activity. The initial success of these measure made for a good prognosis. Both patient and family were advised of the availability of antidepressant drugs, and advised against relocating the patient.
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Transtornos de Adaptação/terapia , Psicoterapia Breve , Transtornos de Adaptação/diagnóstico , Transtornos de Adaptação/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , PrognósticoRESUMO
Self-ratings of memory were studied in 69 institutionalized women. The patients also were evaluated by means of three screening tests for organic brain syndrome (OBS) and a hypochondriasis scale. A negative correlation existed between self-rating of memory and actual memory as measured by the screening tests for OBS, but it was significant (p less than .05) for only one of the tests. There was also a negative correlation (p less than .01) between memory rating and scores on the hypochondriasis scale. Therefore, clinicians should not take patients' memory complaints as valid indicators of OBS, but as possible indicators of hypochondriasis.
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Hipocondríase/psicologia , Memória , Transtornos Neurocognitivos/diagnóstico , Idoso , Feminino , Humanos , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Autoavaliação (Psicologia)RESUMO
Paranoid thinking is a defense mechanism against feelings of inferiority and humiliation. Paranoid behavior serves as a means of getting attention, sympathy and help. A case study of an 81-year-old woman illustrates the nature of geriatric paranoia and the roles of interpersonal relationships, rigid personality, depression, and the impairment of sensory and memory functions. The problem proved to be the effects on the family and neighbors of the patient's verbally expressed paranoid delusions. Treatment consisted of reducing the frequency of these paranoid complaints by means of reality therapy and verbal non-reinforcement.
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Terapia Comportamental , Transtorno da Personalidade Paranoide/terapia , Transtornos da Personalidade/terapia , Terapia da Realidade , Idoso , Feminino , Humanos , Reforço VerbalRESUMO
The hypochondriacal attitudes of 53 aged community residents were studied. No significant correlations were found with situational stress, sex, or ethnicity (English-speaking vs Spanish-speaking). The levels of hypochondriasis appeared to be inversely related to self-evaluation of memory ability. There was no indication of an inherent iatrogenic effect. It was concluded that hypochondriacal behavior is chiefly a function of the underlying personality, which may influence the perception of events as stressful.
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Idoso/psicologia , Atitude , Hipocondríase/psicologia , Etnicidade , Feminino , Humanos , Masculino , Transtornos Neurocognitivos/psicologia , Personalidade , Testes Psicológicos , Fatores SexuaisRESUMO
Three of the most common and convenient measures of senile confusion are informal staff ratings, the Face-Hand Test (FHT) and the Mental Status Questionnaire (MSQ). A group of 112 geriatric patients in two extended care facilities, and a volunteer sample of 40 community aged were examined by means of the FHT and MSQ. These instruments proved valuable in differentiating patients rated as confused from those rated as lucid and alert, and from the community subjects. However, each of these measures, as well as the staff ratings, produced false negative findings. Staff ratings incorrectly identified a hypochondriacal and paranoid patient as confused. The FHT scores of lucid and alert patients with some brain damage were low. MSQ scores of some poorly educated immigrants were very low, even though these patients were rated as lucid and alert by the staff and passed the FHT. One normally lucid and alert patient with a fever and an irregular rapid pulse failed both the FHT and the MSQ. Guidelines for further use of these instruments are presented.
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Demência/diagnóstico , Escalas de Graduação Psiquiátrica , Idoso , Estudos de Avaliação como Assunto , Reações Falso-Negativas , Humanos , Entrevista Psiquiátrica PadronizadaRESUMO
There is a need for rapid and convenient assessment instruments to test the aged for senile confusion due to organic brain syndrome (OBS). The Mental Status Questionnaire (MSQ) and the Face-Hand Test (FHT) have certain limitations. A valid instrument must measure short-term memory loss and recognition. Sixty-two patients were examined in 17 different trials of the Stimulus Recognition Test (SRT), which involves 10 items. Each item classified the patients according to staff ratings (P less than .001), MSQ MSQ scores (P less than .005), and FHT scores (P less than .005). The composite MSQ score on a scale of 0--10 also served to separate the patients according to staff ratings (P less than .005). The SRT scores correlated .81 to .67 with the MSQ and FHT scores. The SRT does not show the same false positive patterns as the MSQ and FHT. For that reason, it constitutes a useful diagnostic supplement. Suggestions for further research are made.
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Transtornos Mentais/diagnóstico , Transtornos Neurocognitivos/diagnóstico , Escalas de Graduação Psiquiátrica , Humanos , Memória , Memória de Curto Prazo , Entrevista Psiquiátrica PadronizadaRESUMO
The staffs at three extended care facilities identified a group of 10 hypochondriacal patients. The research team asked these 10 patients and 59 controls, 27 questions relating to health attitudes and behaviors. Six items were found to be fairly useful in distinguishing hypochondriacal from non-hypochondriacal subjects. These six items were taken as the Hypochondriasis Scale for Institutional Geriatric Patients (HSIG), and each patient scored on the basis of his responses to these six items. This test proved to be one way of distinguishing between hypochondriacal and non-hypochondriacal groups (P less than .005). However, because of the possibility of false positive results, the scale should be used only to confirm staff suspicions of hyponchondriasis and should not be used as part of the clinical intake procedure.
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Hipocondríase/diagnóstico , Escalas de Graduação Psiquiátrica , Idoso , Humanos , MMPI , Instituições de Cuidados Especializados de EnfermagemRESUMO
A new Geriatric Depression Scale (GDS) designed specifically for rating depression in the elderly was tested for reliability and validity and compared with the Hamilton Rating Scale for Depression (HRS-D) and the Zung Self-Rating Depression Scale (SDS). In constructing the GDS a 100-item questionnaire was administered to normal and severely depressed subjects. The 30 questions most highly correlated with the total scores were then selected and readministered to new groups of elderly subjects. These subjects were classified as normal, mildly depressed or severely depressed on the basis of Research Diagnostic Criteria (RDC) for depression. The GDS, HRS-D and SDS were all found to be internally consistent measures, and each of the scales was correlated with the subject's number of RDC symptoms. However, the GDS and the HRS-D were significantly better correlated with RDC symptoms than was the SDS. The authors suggest that the GDS represents a reliable and valid self-rating depression screening scale for elderly populations.
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Transtorno Depressivo/diagnóstico , Testes Psicológicos , Idoso , Transtorno Depressivo/psicologia , Feminino , Humanos , Masculino , PsicometriaRESUMO
The Americans With Disabilities Act (ADA) prohibits employment discrimination on the basis of disability. Originally, an assessment of whether a person had a disability and thus was protected by the ADA examined the person's impairment in its uncorrected state. Thus it was comparatively easy for people with mental illness to meet the threshold requirement for having a disability. However, in 1999 the U.S. Supreme Court issued three decisions holding that, for the purposes of the ADA, disability had to be assessed in its corrected state. Since those decisions were issued, the courts have increased the burden on individuals, including people with mental illness, to prove that they have a disability. In several cases, courts ruled that people with serious mental illnesses do not have a disability and are not protected by the ADA. This article discusses these cases and their implications for people with mental illness and for practitioners.