215 research outputs found
Magnetic field regulated infall on the disc around the massive protostar Cepheus A HW2
We present polarization observations of the 6.7-GHz methanol masers around
the massive protostar Cepheus A HW2 and its associated disc. The data were
taken with the Multi-Element Radio Linked Interferometer Network. The maser
polarization is used to determine the full three-dimensional magnetic field
structure around Cepheus A HW2. The observations suggest that the masers probe
the large scale magnetic field and not isolated pockets of a compressed field.
We find that the magnetic field is predominantly aligned along the protostellar
outflow and perpendicular to the molecular and dust disc. From the
three-dimensional magnetic field orientation and measurements of the magnetic
field strength along the line of sight, we are able to determine that the high
density material, in which the masers occurs, is threaded by a large scale
magnetic field of ~23 mG. This indicates that the protostellar environment at
~1000 AU from Cepheus A HW2 is slightly supercritical (lambda approximately
1.7) and the relation between density and magnetic field is consistent with
collapse along the magnetic field lines. Thus, the observations indicate that
the magnetic field likely regulates accretion onto the disc. The magnetic field
dominates the turbulent energies by approximately a factor of three and is
sufficiently strong to be the crucial component stabilizing the massive
accretion disc and sustaining the high accretion rates needed during massive
star-formation.Comment: 10 pages, 6 figures; accepted for publication in MNRAS. High
resolution version can be found at
http://www.astro.uni-bonn.de/~wouter/papers/papers.shtm
Closure of an iatrogenic tracheo-esophageal fistula with bronchoscopic gluing in a mechanically ventilated adult patient
Management of acquired nonmalignant tracheo-esophageal fistula (TEF) in mechanically ventilated patients is controversial. Surgical correction is often contraindicated because the high operative risk and spontaneous closure is unlikely due to the positive pressure ventilation. We present a case of successful closure of an iatrogenic TEF in a mechanically ventilated patient with bronchoscopic application of fibrin glue. The technique may be proposed in high-risk patients as either an alternative to surgery or as a first-line attempt before surgical correction
Fatigue assessment by energy approach during tensile tests on AISI 304 steel
Estimation of the fatigue limit for steel ductile materials using non-destructive methods is a topic of great interest to researchers today. In recent years, the method adopted has implemented infrared sensors to detect the surface temperature and correlate it with the fatigue limit. In previous paper, a new energy approach was proposed to investigate the fatigue limit during tensile test. The numerical procedure proposed by Chrysochoos is adopted to clean infrared images and applied to analyse the surface heat sources during tensile test. AISI 304 specimens with rectangular cross-sections are tested. Moreover fatigue tests at increasing loads were carried out on steel by a stepwise succession, applied to the same specimen, for applying the thermographic method. The predictions of the fatigue limit, obtained by the analysis of the energy evolution during the static tests, were compared with the predictions obtained applying the thermographic method during fatigue tests
Healing of bronchopleural fistula using a modified Dumon stent: a case report
BACKGROUND: Brochopleural fistula following lung resection is a therapeuric challenge for thoracic surgeons. CASE PRESENTATION: We describe a case of late bronchopleural fistula after right extrapleural pneumonectomy for malignant mesothelioma. Bronchoscopic attempts to repair it were unsuccessful. CONCLUSION: The use of a modified Y Dumon stent associated with glue apposition on the bronchial stump allowed us to close the fistula without the need of any surgical repair
Impact of environmental pollution and weather changes on the incidence of ST-elevation myocardial infarction
Background: Environmental pollution and weather changes unfavorably impact on cardiovascular disease. However, limited research has focused on ST-elevation myocardial infarction (STEMI), the most severe yet distinctive form of acute coronary syndrome. Methods and results: We appraised the impact of environmental and weather changes on the incidence of STEMI, analysing the bivariate and multivariable association between several environmental and atmospheric parameters and the daily incidence of STEMI in two large Italian urban areas. Specifically, we appraised: carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NOX), ozone, particulate matter smaller than 10 μm (PM10) and than 2.5 μm (PM2.5), temperature, atmospheric pressure, humidity and rainfall. A total of 4285 days at risk were appraised, with 3473 cases of STEMI. Specifically, no STEMI occurred in 1920 (44.8%) days, whereas one or more occurred in the remaining 2365 (55.2%) days. Multilevel modelling identified several pollution and weather predictors of STEMI. In particular, concentrations of CO (p=0.024), NOX (p=0.039), ozone (p=0.003), PM10 (p=0.033) and PM2.5 (p=0.042) predicted STEMI as early as three days before the event, as well as subsequently, and NO predicted STEMI one day before (p = 0.010), as well as on the same day. A similar predictive role was evident for temperature and atmospheric pressure (all p < 0.05). Conclusions: The risk of STEMI is strongly associated with pollution and weather features. While causation cannot yet be proven, environmental and weather changes could be exploited to predict STEMI risk in the following days
Mechanisms of adverse effects of anti-VEGF therapy for cancer
Advances in understanding the role of vascular endothelial growth factor (VEGF) in normal physiology are giving insight into the basis of adverse effects attributed to the use of VEGF inhibitors in clinical oncology. These effects are typically downstream consequences of suppression of cellular signalling pathways important in the regulation and maintenance of the microvasculature. Downregulation of these pathways in normal organs can lead to vascular disturbances and even regression of blood vessels, which could be intensified by concurrent pathological conditions. These changes are generally manageable and pose less risk than the tumours being treated, but they highlight the properties shared by tumour vessels and the vasculature of normal organs
Capecitabine and bevacizumab as first-line treatment in elderly patients with metastatic colorectal cancer
BACKGROUND: The efficacy and safety of capecitabine and bevacizumab in elderly patients with metastatic colorectal cancer (mCRC)
considered unsuitable for receiving first-line chemotherapy with an irinotecan or oxaliplatin-based combination were assessed in a
phase II, open, multicentre, uncontrolled study.
METHODS: Treatment consisted of capecitabine 1250 mgm 2 (or 950 mgm 2 for patients with a creatinine clearance of
30–50ml min 1) twice daily on days 1–14 and bevacizumab (7.5 mg kg 1) on day 1 every 3 weeks.
RESULTS: A total of 59 patients aged X70 years with mCRC were enrolled. In an intention-to-treat analysis, the overall response rate
was 34%, with 71% of patients achieving disease control. Median progression-free survival and overall survival were 10.8 months and
18 months, respectively. In all, 32 patients (54%) had grade 3/4 adverse events (AEs), the most common being hand–foot syndrome
(19%), diarrhoea (9%) and deep venous thrombosis (7%). Four patients died because of treatment-related AEs. A relationship was
detected between creatinine clearance p50 ml min 1 and the development of non-bevacizumab-related grade 3/4 AEs. The
incidence of bevacizumab-associated AEs (hypertension, thromboembolic events and proteinuria) was consistent with that of
previous reports in elderly patients.
CONCLUSION: Bevacizumab combined with capecitabine represents a valid therapeutic alternative in elderly patients considered to be
unsuitable for receiving polychemotherapy.This study was supported by Hoffmann-La Roche, Nutley, NJ,
USA
A randomized two arm phase III study in patients post radical resection of liver metastases of colorectal cancer to investigate bevacizumab in combination with capecitabine plus oxaliplatin (CAPOX) vs CAPOX alone as adjuvant treatment
<p>Abstract</p> <p>Background</p> <p>About 50% of patients with colorectal cancer are destined to develop hepatic metastases. Radical resection is the most effective treatment for patients with colorectal liver metastases offering five year survival rates between 36-60%. Unfortunately only 20% of patients are resectable at time of presentation. Radiofrequency ablation is an alternative treatment option for irresectable colorectal liver metastases with reported 5 year survival rates of 18-30%. Most patients will develop local or distant recurrences after surgery, possibly due to the outgrowth of micrometastases present at the time of liver surgery. This study aims to achieve an improved disease free survival for patients after resection or resection combined with RFA of colorectal liver metastases by adding the angiogenesis inhibitor bevacizumab to an adjuvant regimen of CAPOX.</p> <p>Methods/design</p> <p>The Hepatica study is a two-arm, multicenter, randomized, comparative efficacy and safety study. Patients are assessed no more than 8 weeks before surgery with CEA measurement and CT scanning of the chest and abdomen. Patients will be randomized after resection or resection combined with RFA to receive CAPOX and Bevacizumab or CAPOX alone. Adjuvant treatment will be initiated between 4 and 8 weeks after metastasectomy or resection in combination with RFA. In both arms patients will be assessed for recurrence/new occurrence of colorectal cancer by chest CT, abdominal CT and CEA measurement. Patients will be assessed after surgery but before randomization, thereafter every three months after surgery in the first two years and every 6 months until 5 years after surgery. In case of a confirmed recurrence/appearance of new colorectal cancer, patients can be treated with surgery or any subsequent line of chemotherapy and will be followed for survival until the end of study follow up period as well. The primary endpoint is disease free survival. Secondary endpoints are overall survival, safety and quality of life.</p> <p>Conclusion</p> <p>The HEPATICA study is designed to demonstrate a disease free survival benefit by adding bevacizumab to an adjuvant regime of CAPOX in patients with colorectal liver metastases undergoing a radical resection or resection in combination with RFA.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier NCT00394992</p
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