The complex circumstellar environment of supernova 2023ixf.

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.

A Wolf-Rayet-like progenitor of SN 2013cu from spectral observations of a stellar wind.

The explosive fate of massive Wolf-Rayet stars (WRSs) is a key open question in stellar physics. An appealing option is that hydrogen-deficient WRSs are the progenitors of some hydrogen-poor supernova explosions of types IIb, Ib and Ic (ref. 2). A blue object, having luminosity and colours consistent with those of some WRSs, has recently been identified in pre-explosion images at the location of a supernova of type Ib (ref. 3), but has not yet been conclusively determined to have been the progenitor. Similar work has so far only resulted in non-detections. Comparison of early photometric observations of type Ic supernovae with theoretical models suggests that the progenitor stars had radii of less than 10(12) centimetres, as expected for some WRSs. The signature of WRSs, their emission line spectra, cannot be probed by such studies. Here we report the detection of strong emission lines in a spectrum of type IIb supernova 2013cu (iPTF13ast) obtained approximately 15.5 hours after explosion (by 'flash spectroscopy', which captures the effects of the supernova explosion shock breakout flash on material surrounding the progenitor star). We identify Wolf-Rayet-like wind signatures, suggesting a progenitor of the WN(h) subclass (those WRSs with winds dominated by helium and nitrogen, with traces of hydrogen). The extent of this dense wind may indicate increased mass loss from the progenitor shortly before its explosion, consistent with recent theoretical predictions.

PTF 11kx: a type Ia supernova with a symbiotic nova progenitor.

There is a consensus that type Ia supernovae (SNe Ia) arise from the thermonuclear explosion of white dwarf stars that accrete matter from a binary companion. However, direct observation of SN Ia progenitors is lacking, and the precise nature of the binary companion remains uncertain. A temporal series of high-resolution optical spectra of the SN Ia PTF 11kx reveals a complex circumstellar environment that provides an unprecedentedly detailed view of the progenitor system. Multiple shells of circumstellar material are detected, and the SN ejecta are seen to interact with circumstellar material starting 59 days after the explosion. These features are best described by a symbiotic nova progenitor, similar to RS Ophiuchi.

Primary atherothrombotic occlusive vascular events in premenopausal women with history of adverse pregnancy outcome.

OBJECTIVE: To determine if adverse pregnancy outcomes are associated with atherothrombotic occlusive vascular disease (AOVD) in premenopausal women. DESIGN: Retrospective matched case-control study. SETTING: Tertiary, university-affiliated medical center. POPULATION: Women aged less than 50 years treated for an AOVD (primary cerebrovascular, myocardial, or peripheral arterial ischemic event) from 1995 to 2004. METHOD: The files were reviewed for classical risk factors for AOVD and complications of pregnancy (abortions, pregnancy-induced hypertension, preeclampsia, gestational diabetes, intrauterine growth restriction (IUGR), fetal loss and preterm delivery). Findings were compared with healthy women matched for age and body mass index. MAIN OUTCOME MEASURES: Past pregnancy complications in premenopausal women with AOVD. RESULTS: Of the 101 women with AOVD, 53 had a myocardial ischemic event, 33 a cerebrovascular event, and 15 a peripheral ischemic arterial event. On multivariate analysis, IUGR (OR 8.41, 95% CI 2.36-29.9, p=0.001) and more than one pregnancy complication (OR 13.7, 95% CI 1.56-120, p=0.02) were found to be independent significant variables associated with AOVD. CONCLUSION: IUGR and composite pregnancy complications are independent significant variables associated with AOVD in premenopausal period. Pregnancy outcome might serve as a means to identify patients who may require increased medical surveillance and preventive measures for later vascular disease.

Use of complementary and alternative medicine among cancer patients in Israel.

Complementary and alternative medicine (CAM) has gained in popularity among cancer patients in recent years. The present study assessed the patterns of CAM use among cancer patients in Israel. The design of the study was descriptive cross-sectional, and data were collected using a 27-item questionnaire. The sample consisted of 111 Israeli cancer patients who were part of a larger European study. Among the participants, past or current CAM use was reported by 32.4% (n=36). The most common therapies used included herbal medicine (22.2%), spiritual therapies (19.4%), visualization and relaxation techniques (16.7% for each), and vitamins/minerals (13.9%). Younger patients with higher education, higher annual income, and previous standard treatment were more likely to use CAM. The mean satisfaction and perceived effectiveness scores were 5.36+/-1.37 and 5.48+/-1.39, respectively, out of a maximum score of 7. The main benefits from CAM reported by patients included improvement in emotional and physical well-being (40% and 34.3%, respectively) and increased ability to fight the disease (31.4%), although 17.1% of patients reported no benefits at all from CAM. The main sources of information about CAM were friends/family and the media. Findings suggest that due to the relatively high use of CAM among cancer patients, this topic should be taken into account in a holistic approach to this patient population.

The influence of nurses' knowledge, attitudes, and health beliefs on their safe behavior with cytotoxic drugs in Israel.

The purpose of this study was to examine the influence of the nurses' knowledge, attitudes, and health beliefs on their behavior and their actual usage of safety measures while handling cytotoxic drugs in their daily work surroundings. The Health Belief Model (HBM) and its extensive form, the Protection Motivation Theory (PMT), were used as the theoretical frameworks. Sixty-one nurses participated in the study, 31 hospital-based nurses daily exposed to cytotoxic drugs for the last 5 years, and 30 non-exposed community nurses. An occupational questionnaire was used to test the nurses' actual safe behavior and compliance with the recommended guidelines. A randomly selected group of exposed nurses were observed to validate their compliant behavior. A gap was found between the nurses' knowledge and their actual behavior concerning the potential risks of cytotoxic drugs and their use of protective measures (p < .005). Significant correlations were found among the components of the extensive HBM (perceived susceptibility, barriers, benefits and self-efficacy). The observational findings supported the above results. The study's findings support the need to promote primary prevention by providing a safe environment for the employee by means of education, training with regard to safety measures, clear policy, written guidelines and their enforcement.

Monoclonal antibodies to a rat colon carcinoma: model for monoclonal antibody therapy of solid tumors.

Tumor progression, lung metastasis, and death occur in tumor-bearing BD IX syngeneic rats in a fashion similar to the course of patients with metastatic colon cancer. In an effort to establish a relevant model for monoclonal antibody (MoAb) therapy of tumors, we generated murine MoAb against DHD/TR, a dimethylhydrazine-induced rat colon carcinoma which has been adapted to cell culture. Murine MoAb 17B10 E4 (E4) reacts with the TR tumor and shows weak immunoperoxidase reactivity with normal rat tissues. Murine MoAb 5F7 D3 (D3) reacts with the tumor and a variety of normal rat epithelia. Both are IgG2a and mediate cytotoxicity by rat peripheral blood mononuclear cells. 18D5 F6 (F6) also reacts with the tumor and normal tissues but is an IgG2b and does not mediate cytotoxicity in the presence of rat effector cells. Iodinated E4 and D3 antibodies retained their immunoreactivity. E4 revealed 9.8 x 10(5) antigenic sites per TR cell, with an affinity constant of 9.35 x 10(7) M-1, while D3 demonstrated 2.5 x 10(6) antigenic sites and an affinity constant of 4.2 x 10(7) M-1. Immunoblotting showed that the antigens recognized by D3 and E4 are glycoproteins with molecular weights of 27,000 and 66,000, respectively. F6 failed to react with its antigen present in the blot. This rat colon carcinoma and the monoclonal antibodies described here may provide experimental data useful for implementing monoclonal antibodies in cancer therapy.