43 research outputs found

    Five Lectures On Dissipative Master Equations

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    1 First Lecture: Basics 1.1 Physical Derivation of the Master Equation 1.2 Some Simple Implications 1.3 Steady State 1.4 Action to the Left 2 Second Lecture: Eigenvalues and Eigenvectors of L 2.1 A Simple Case First 2.2 The General Case 3 Third Lecture: Completeness of the Damping Bases 3.1 Phase Space Functions 3.2 Completeness of the Eigenvectors of L 3.3 Positivity Conservation 3.4 Lindblad Form of Liouville Operators 4 Fourth Lecture: Quantum-Optical Applications 4.1 Periodically Driven Damped Oscillator 4.2 Conditional and Unconditional Evolution 4.3 Physical Signicance of Statistical Operators 5 Fifth Lecture: Statistics of Detected Atoms 5.1 Correlation Functions 5.2 Waiting Time Statistics 5.3 Counting StatisticsComment: 58 pages, 10 figures; book chapter to appear in ``Coherent Evolution in Noisy Environments'', Lecture Notes in Physics, (Springer Verlag, Berlin-Heidelberg-New York). Notes of lectures given in Dresden,23-27 April 200

    Adjuvant gemcitabine and concurrent radiation for patients with resected pancreatic cancer: a phase II study

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    The safety and efficacy of gemcitabine and concurrent radiation to the upper abdomen followed by weekly gemcitabine in patients with resected pancreatic cancer was determined. Patients with resected adenocarcinoma of the pancreas were treated with intravenous gemcitabine administered twice-weekly (40 mg m−2) for 5 weeks concurrent with upper abdominal radiation (50.4 Gy in 5½ weeks). At the completion of the chemoradiation, patients without disease progression were given gemcitabine (1000 mg m−2) weekly for two cycles. Each cycle consisted of 3 weeks of treatment followed by 1 week without treatment. Forty-seven patients were entered, 46 of whom are included in this analysis. Characteristics: median age 61 years (range 35–79); 24 females (58%); 73% stage T3/T4; and 70% lymph node positive. Grade III/IV gastrointestinal or haematologic toxicities were infrequent. The median survival was 18.3 months, while the median time to disease recurrence was 10.3 months. Twenty-four percent of patients were alive at 3 years. Only six of 34 patients with progression experienced local regional relapse as a component of the first site of failure. These results confirm the feasibility of delivering adjuvant concurrent gemcitabine and radiation to the upper abdomen. This strategy produced good local regional tumour control

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Impact of truck characteristics on pavements - truck load equivalency factors. Final report.

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    Federal Highway Administration, Office of Engineering and Highway Operations Research and Development, McLean, Va.Mode of access: Internet.Author corporate affiliation: ARE Inc., Austin, Tex.Report covers the period Jan - July 1992Subject code: CDFSubject code: DEFGSubject code: NKJCSubject code: NLSJSubject code: NOB*CDFSubject code: WOB*
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