621 research outputs found
LOCALIZATION OF PULMONARY THROMBOEMBOLISM - AN IMPORTANT PROGNOSTIC FACTOR
The prognosis of pulmonary thromboembolism is a serious challenge for the clinicians. A total of 967 patients with pulmonary thromboembolism, 511 males and 456 females at a mean age of 60,1 ±13,7 years were analyzed. A special protocol consisting of 52 parameters was used to define their prognostic value. A non-invasive diagnostic algorithm based on symptoms, ECG, pulmonary roentgenography, perfusion scintigraphy, spiral scan, pulmoangiography, or on autopsy was applied. A prognostic index was elaborated by means of multifactorial analysis of the parameters of prognostic significance concerning the risk of lethal outcome. The localization of the pulmonary thromboembolism as determined by using spiral C T can effectively be used for patients' risk stratification
Quasi two-dimensional antiferromagnet on a triangular lattice RbFe(MoO4)2
RbFe(MoO4)2 is a rare example of a nearly two-dimensional Heisenberg
antiferromagnet on a triangular lattice. Magnetic resonance spectra and
magnetization curves reveal that the system has a layered spin structure with
six magnetic sublattices. The sublattices within a layer are arranged in a
triangular manner with the magnetization vectors 120 degree apart. The H-T
phase diagram, containing at least five different magnetic phases is
constructed. In zero field, RbFe(MoO4)2 undergoes a phase transition at T_N=3.8
K into a non-collinear triangular spin structure with all the spins confined in
the basal plane. The application of an in-plane magnetic field induces a
collinear spin state between the fields H_c1=47 kOe and H_c2=71 kOe and
produces a magnetization plateau at one-third of the saturation moment. Both
the ESR and the magnetization measurements also clearly indicate an additional
first-order phase transition in a field of 35 kOe. The exact nature of this
phase transition is uncertain.Comment: 9 pages incl 11 figure
Forbush decrease observed by SEVAN particle detector network on November 4, 2021
On November 3-4 2021, an interplanetary coronal mass injection (ICME) hits
the magnetosphere, sparking a strong G3-class geomagnetic storm and auroras as
far south as California and New Mexico. All detectors of the SEVAN network
registered a Forbush decrease (FD) of 5-10 percentdeep in 1 minute time series
of count rates. We present the results of a comparison of Fd registered on
mountain altitudes on Aragats (Armenia), Lomnicky Stit (Slovakia), Musala
(Bulgaria), and at sea level DESY (Hamburg, Germany), and in Mileshovka,
Czechia. We present as well purity and barometric coefficients of different
coincidences of SEVAN detector layers on Aragats. We demonstrate disturbances
of the near-surface electric (NSEF) and geomagnetic fields at the arrival of
the ICME on Earth
Properties of the Volume Operator in Loop Quantum Gravity II: Detailed Presentation
The properties of the Volume operator in Loop Quantum Gravity, as constructed
by Ashtekar and Lewandowski, are analyzed for the first time at generic
vertices of valence greater than four. The present analysis benefits from the
general simplified formula for matrix elements of the Volume operator derived
in gr-qc/0405060, making it feasible to implement it on a computer as a matrix
which is then diagonalized numerically. The resulting eigenvalues serve as a
database to investigate the spectral properties of the volume operator.
Analytical results on the spectrum at 4-valent vertices are included. This is a
companion paper to arXiv:0706.0469, providing details of the analysis presented
there.Comment: Companion to arXiv:0706.0469. Version as published in CQG in 2008.
More compact presentation. Sign factor combinatorics now much better
understood in context of oriented matroids, see arXiv:1003.2348, where also
important remarks given regarding sigma configurations. Subsequent
computations revealed some minor errors, which do not change qualitative
results but modify some numbers presented her
Multi-Institutional Datasets Validate the Recursive Partitioning Analysis for Overall Survival in Patients Undergoing Spine Radiosurgery for Spine Metastasis
Purpose/Objective(s): The recently published spine radiosurgery (sSRS) recursive partitioning analysis (RPA) for overall survival (OS) separated patients into 3 distinct prognostic groups. We sought to externally validate this RPA using a multi-institutional dataset.
Materials/Methods: A total of 444 patients were utilized to develop the recently published sSRS RPA predictive of OS in patients with spine metastases. The RPA identified three distinct prognostic classes. RPA Class 1 was defined as KPS \u3e70 and controlled systemic disease (n=142); RPA Class 2 was defined as KPS\u3e70 with uncontrolled systemic disease or KPS ≤70, age ≥54 and absence of visceral metastases (n=207); RPA Class 3 was defined as KPS ≤70 and age \u3c54 years or KPS≤70, age ≥54 years and presence of visceral metastases (n=95). We utilized data from large tertiary care centers to validate this RPA. A total of 749 patients were in the validation cohort and were divided based on their RPA Class. Kaplan-Meier method was used to estimate OS and log-rank test was used to compare OS between RPA classes.
Results: In the validation cohort (749 patients), the median OS was 11.0 months. One-hundred-thirteen (15.1%) patients were in RPA Class 1, 432 (57.7%) patients in RPA Class 2 and 204 (27.2%) patients in RPA Class 3. The median OS in the validation cohort based on RPA Class was 27.1 months for Class 1, 13.0 months for Class 2 and 3.5 months for Class 3. Patients in RPA Class 1 had a significantly better OS compared to those in Class 2 of the validation cohort (p\u3c0.01). Similarly, patients in RPA Class 2 had a significantly better OS compared to those in Class 3 (p\u3c0.01).
Conclusion: The external datasets from two large centers validated the spine SRS RPA successfully for RPA for OS for patients undergoing sSRS for spinal metastases. This is the first RPA for OS to have been externally validated using a large dataset. Based on this validation, upfront spine SRS is strongly supported for patients in RPA Class 1. Upfront SRS is also supported for RPA Class 2 patients. Patients in RPA Class 3 would benefit most from upfront conventional radiotherapy given their poor expected survival. Given successful external validation, this RPA helps guide physicians to identify those patients with spinal metastases who most benefit from sSRS
Impact of KRAS mutation status on the efficacy of immunotherapy in lung cancer brain metastases
Immune checkpoint inhibitors (ICIs) have resulted in improved outcomes in non-small cell lung cancer (NSCLC) patients. However, data demonstrating the efficacy of ICIs in NSCLC brain metastases (NSCLCBM) is limited. We analyzed overall survival (OS) in patients with NSCLCBM treated with ICIs within 90 days of NSCLCBM diagnosis (ICI-90) and compared them to patients who never received ICIs (no-ICI). We reviewed 800 patients with LCBM who were diagnosed between 2010 and 2019 at a major tertiary care institution, 97% of whom received stereotactic radiosurgery (SRS) for local treatment of BM. OS from BM was compared between the ICI-90 and no-ICI groups using the Log-Rank test and Cox proportional-hazards model. Additionally, the impact of KRAS mutational status on the efficacy of ICI was investigated. After accounting for known prognostic factors, ICI-90 in addition to SRS led to significantly improved OS compared to no-ICI (12.5 months vs 9.1, p \u3c 0.001). In the 109 patients who had both a known PD-L1 expression and KRAS status, 80.4% of patients with KRAS mutation had PD-L1 expression vs 61.9% in wild-type KRAS patients (p = 0.04). In patients without a KRAS mutation, there was no difference in OS between the ICI-90 vs no-ICI cohort with a one-year survival of 60.2% vs 54.8% (p = 0.84). However, in patients with a KRAS mutation, ICI-90 led to a one-year survival of 60.4% vs 34.1% (p = 0.004). Patients with NSCLCBM who received ICI-90 had improved OS compared to no-ICI patients. Additionally, this benefit appears to be observed primarily in patients with KRAS mutations that may drive the overall benefit, which should be taken into account in the development of future trials
Brain metastases as primary manifestation of a melanocytic malignant peripheral nerve sheath tumor in a 60-year-old man
BACKGROUND: Malignant peripheral nerve sheath tumors are rare tumor entities that originate from peripheral nerve sheaths and have an unfavorable prognosis. Metastatic spread to the cerebral parenchyma is absolutely rare. This case report describes the clinical course in a 60-year-old man whose tumor came to medical attention because of a seizure. CASE PRESENTATION: Magnetic resonance imaging demonstrated two intracerebral lesions. The symptomatic lesion was removed microneurosurgically and histology demonstrated a metastasis from a malignant peripheral nerve sheath tumor. Postoperatively, whole-brain irradiation was performed. The primary tumor was identified in the area of the sciatic nerve on the right. Follow-up 14 months after resection showed that there was no progression of the intracerebral lesions but an increase in size and number of distant metastases. CONCLUSION: There are no generally accepted guidelines for the treatment of malignant peripheral nerve sheath tumors with cerebral metastases. This case report presents and discusses one possible therapeutic approach. Due to the poor overall prognosis, the least invasive therapy should be chosen
Transition Radiation Spectroscopy with Prototypes of the ALICE TRD
We present measurements of the transition radiation (TR) spectrum produced in
an irregular radiator at different electron momenta. The data are compared to
simulations of TR from a regular radiator.Comment: 4 pages, 5 Figures, Proceedings for "TRDs for the 3rd millennium"
(Sept. 4-7, 2003, Bari, Italy
Crime, bandits, and community: how public panic shaped the social control of territory in the Ottoman Empire
This study explores the role of crime, bandits, and public panic in in the nineteenth century Ottoman society by using archival documents and employing a comparative perspective. In addition to the social bandit concept of Eric Hobsbawm, there is an introduction of two new banditry forms in this study—opportunist bandits and imagined bandits. The comparison of different bandit forms clarifies that social bandits and opportunist bandits aggravated public panic and produced imagined bandits. Hence, public panic and the dissent of local people unveiled through rumors about the imagined bandits. The exploration of different forms of bandits in the Ottoman Empire is a response to the vexed issue concerning the challenges in the social control of territories in a multiethnic and multi-religious empire. This study provides new conceptual tools to rethink about the spatial dimensions in the emergence of bandits. This article shows that spatial factors in the social control of territory can be influenced by the reaction of local people from bottom-to-top and, in doing so, can determine the response of state authority. The present study, therefore, unveils the power relationship in the social control of territory whether it is manifested by physical force or public panic.N/
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Characterization and intercomparison of aerosol absorption photometers: Result of two intercomparison workshops
Absorption photometers for real time application have been available since the 1980s, but the use of filter-based instruments to derive information on aerosol properties (absorption coefficient and black carbon, BC) is still a matter of debate. Several workshops have been conducted to investigate the performance of individual instruments over the intervening years. Two workshops with large sets of aerosol absorption photometers were conducted in 2005 and 2007. The data from these instruments were corrected using existing methods before further analysis. The inter-comparison shows a large variation between the responses to absorbing aerosol particles for different types of instruments. The unit to unit variability between instruments can be up to 30% for Particle Soot Absorption Photometers (PSAPs) and Aethalometers. Multi Angle Absorption Photometers (MAAPs) showed a variability of less than 5%. Reasons for the high variability were identified to be variations in sample flow and spot size. It was observed that different flow rates influence system performance with respect to response to absorption and instrumental noise. Measurements with non absorbing particles showed that the current corrections of a cross sensitivity to particle scattering are not sufficient. Remaining cross sensitivities were found to be a function of the total particle load on the filter. The large variation between the response to absorbing aerosol particles for different types of instruments indicates that current correction functions for absorption photometers are not adequate
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