70 research outputs found

    A stochastic programming approach for chemotherapy appointment scheduling

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    Chemotherapy appointment scheduling is a challenging problem due to the uncertainty in pre-medication and infusion durations. In this paper, we formulate a two-stage stochastic mixed integer programming model for the chemotherapy appointment scheduling problem under limited availability and number of nurses and infusion chairs. The objective is to minimize the expected weighted sum of nurse overtime, chair idle time, and patient waiting time. The computational burden to solve real-life instances of this problem to optimality is significantly high, even in the deterministic case. To overcome this burden, we incorporate valid bounds and symmetry breaking constraints. Progressive hedging algorithm is implemented in order to solve the improved formulation heuristically. We enhance the algorithm through a penalty update method, cycle detection and variable fixing mechanisms, and a linear approximation of the objective function. Using numerical experiments based on real data from a major oncology hospital, we compare our solution approach with several scheduling heuristics from the relevant literature, generate managerial insights related to the impact of the number of nurses and chairs on appointment schedules, and estimate the value of stochastic solution to assess the significance of considering uncertainty

    Azimuthal separation in nearly back-to-back jet topologies in inclusive 2-and 3-jet events in pp collisions at root s=13TeV

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    A measurement for inclusive 2- and 3-jet events of the azimuthal correlation between the two jets with the largest transverse momenta, Delta phi(12), is presented. The measurement considers events where the two leading jets are nearly collinear ("back-to-back") in the transverse plane and is performed for several ranges of the leading jet transverse momentum. Proton-proton collision data collected with the CMS experiment at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 35.9 fb(-1) are used. Predictions based on calculations using matrix elements at leading-order and next-to-leading-order accuracy in perturbative quantum chromodynamics supplemented with leading-log parton showers and hadronization are generally in agreement with themeasurements. Discrepancies between the measurement and theoretical predictions are as large as 15%, mainly in the region 177 degrees <Delta phi(12) <180 degrees. The 2- and 3-jet measurements are not simultaneously described by any of models.Peer reviewe

    Observation of the χb1(3P)\chi_{b1}(3P) and χb2(3P)\chi_{b2}(3P) and measurement of their masses

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    The χb1(3P)\chi_{b1}(3P) and χb2(3P)\chi_{b2}(3P) states are observed through their γ(3S)γ\gamma(3S)_\gamma decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0  fb180.0  fb^{−1}. Theγ(3S)\gamma(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e+ee^+e ^− pairs in the silicon tracker, leading to a χb1(3P)\chi_{b1}(3P) mass resolution of 2.2 MeV. This is the first time that the J=1 and 2 states are well resolved and their masses individually measured: 10513.42±0.41(stat)±0.18(syst)  MeV10513.42±0.41(stat)±0.18(syst)  MeV and 10524.02±0.57(stat)±0.18(syst)  MeV10524.02±0.57(stat)±0.18(syst)  MeV; they are determined with respect to the world-average value of the γ(3S)\gamma(3S) mass, which has an uncertainty of 0.5 MeV. The mass splitting is measured to be 10.60±0.64(stat)±0.17(syst)  MeV10.60±0.64(stat)±0.17(syst)  MeV

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    THE MANAGEMENT OF TUBO-OVARIAN ABSCESS

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    Objective: To determine the management of tubo-ovarian abscess (TOA) and put out the complications in patients operated on

    What do repetitive thinking styles tell about hyperemesis gravidarum?

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    OBJECTIVES: Although there are studies investigating the relationship between anxiety disorders, depression, and hyperemesis gravidarum (HG), none have sufficiently clarified the link between underlying psychological processes and HG. The present study aimed to examine the relationship between rumination, worry, and HG and their possible triggering effects on HG. METHODS: The study was designed as a prospective, self-reported, cohort research and the study sample consists of 350 pregnant women. Socio-demographic Form, Ruminative Thinking Style Questionnaire (RTSQ), Trait Anxiety Inventory (STAI-2), and Beck Depression Inventory (BDI) were administered to the participants at the first 6 weeks of their pregnancies (time 1). Second consultation was made to detect women with HG diagnosis between the 6 and 18 weeks’ gestation (time 2). Forty participants diagnosed with HG and 40 randomly chosen participants who had healthy pregnancy process at the end of the 18th gestational week were compared by using independent-samples T-test. RESULTS: While there was no significant difference between the time 1 RTSQ scores and the time 1 BDI scores of the HG and control groups, time 1 STAI-2 scores of the HG group were found to be significantly higher than the control group. CONCLUSIONS: Our results show that worry process plays an active role in the development of HG rather than rumination. As a well-known mechanism of trait anxiety, worry could be a vulnerability factor for HG

    Sentinel lymph node biopsy in endometrial cancer: description of the technique and preliminary results

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    Objective: To measure the feasibility of sentinel lymph node technique in endometrial cancer

    A CASE OF GASTROINTESTINAL STROMAL TUMOR PRESENTING AS A TUBOOVARIAN ABSCESS

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    A gastrointestinal stromal tumor (GIST) is a rare tumor of the gastrointestinal tract. Although stomach is the most frequent site of occurrence, GISTs can arise from anywhere in the gastrointestinal tract. The most common symptoms are vague and nonspecific abdominal pain or discomfort. We would like to present a GIST case with the complaint of acute abdominal pain and fever due to an accompanying complex adnexial mass. A 47-year-old female patient with sudden onset abdominal pain and fever applied at our clinic. A 8 cm diameter sized, complex, solid mass on the ultrasonografic examination was found. Her temperature was 38.6 degrees C and on her laboratory examination, leukocyte and CRP values were 27.400 and 254, respectively After an initial diagnosis of tuboovarian abscess, the patient was internalized. Abdominal CT revealed a solid lesion originating from small bowel resulting in signs of sepsis due to a closed perforation. Resection of the mass was performed and the postop pathology report was GIST. Patient had adjuvant imatinib therapy Although GIST's are mostly seen in stomach with vague symptoms, large sized GIST's which occur in the lower abdomen can be complicated and present as having a tuboovarian abscess clinic

    Determination of serum CRP, VEGF, Leptin, CK-MB, CA-15-3 and IL-6 levels for malignancy prediction in adnexal masses

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    Objective: Investigation of serum markers which could be used in the malignancy prediction of adnexal masses

    Outcomes of pregnancies complicated by hyperemesis gravidarum

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    To evaluate maternal and fetal outcomes among women with hyperemesis gravidarum (HG)
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