101 research outputs found

    Commissioning of the vacuum system of the KATRIN Main Spectrometer

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    The KATRIN experiment will probe the neutrino mass by measuring the beta-electron energy spectrum near the endpoint of tritium beta-decay. An integral energy analysis will be performed by an electro-static spectrometer (Main Spectrometer), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m^3, and a complex inner electrode system with about 120000 individual parts. The strong magnetic field that guides the beta-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. A system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips has been deployed and was tested during the commissioning of the spectrometer. In this paper the configuration, the commissioning with bake-out at 300{\deg}C, and the performance of this system are presented in detail. The vacuum system has to maintain a pressure in the 10^{-11} mbar range. It is demonstrated that the performance of the system is already close to these stringent functional requirements for the KATRIN experiment, which will start at the end of 2016.Comment: submitted for publication in JINST, 39 pages, 15 figure

    Amenorrhea and pituitary human chorionic gonadotrophin production in a 38-year-old presenting as pregnancy of unknown location: case report and review of literature

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    Background: Amenorrhea and extraplacental production of serum human chorionic gonadotropin (hCG), particularly in young women, can mimic a pregnancy of unknown location. Elevated serum hCG in the absence of pregnancy can pose a diagnostic dilemma and has led to potentially harmful and unwarranted interventions including chemotherapeutic agents like methotrexate or have led to delay in necessary medical interventions in women. We report a case to demonstrate that amenorrhea and extraplacental human chorionic gonadotropin (hCG) production in young women can mimic a pregnancy of unknown location. Furthermore, we performed a critical review of literature on pituitary hCG production. Case: A 38-year-old woman with a diagnosis of Silver-Russell syndrome, a unicornuate uterus, history of right oophorectomy for a benign serous cystadenoma and a desire for pregnancy presenting with a provisional diagnosis of pregnancy of unknown location.After performing a thorough review of history, physical examination, ultrasound exams, and a review of hormone analysis [including hCG, Tumor markers, Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Anti-Mullerian Hormone (AMH), Estradiol (E2) levels], we confirmed the diagnosis of premature ovarian insufficiency and pituitary hCG production. Conclusions: In women, serum levels of hCG may increase with age, and are not always an indicator of pregnancy. Therefore, it is imperative to interpret false-positive test results and rule out the extraplacental production of hCG. This will help prevent unnecessary surgical procedures and treatment, including chemotherapy

    Prevalence of maternal complications and neonatal outcomes at a Midwest academic health center

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    Introduction: The University of Iowa Hospitals and Clinics (UIHC) serves as the main referral center for Iowa and has seen increased delivery volumes following many hospital closures across the state. Maternal characteristics are also shifting as pre-pregnancy obesity of reproductive-age women is increasing nationally and in Iowa; average maternal age at first delivery has also increased over time. The aim of the current study was to characterize the outcomes of the delivering population at UIHC over a one-year period to better understand the population we serve, as well as compare our population to state and national delivering populations. Methods: This study is a secondary analysis of a pre-existing prospectively gathered database related to COVID-19 in pregnancy. The current study included all pregnant patients who delivered or underwent procedures for a spontaneous or induced second-trimester abortion on the labor and delivery unit at UIHC between May 1, 2020, and April 30, 2021. Demographic and clinical data including maternal characteristics, delivery information, maternal complications, and neonatal outcomes were obtained from the electronic medical record and double entered in a Research Electronic Data Capture (REDCap) database. Continuous and categorical variables were summarized using medians and ranges. Results: The median maternal age among the 2497 delivering patients was 30 (IQR 26, 33). The median pre-delivery body mass index (BMI) was 32 (IQR 28, 37), which included 439 patients (17.6%) with BMI >40 at time of delivery. 1769 (70.8%) patients listed White as their self-defined race and 2275 (91.0%) listed English as their preferred language. 23% had hypertensive disease of pregnancy. The patients delivered a total of 2603 neonates, with 907 (34.8%) born by cesarean section. 18.7% of deliveries were preterm and 16.6% of neonates had low birth weight. Discussion: The delivering population at UIHC has a high rate of obesity and preeclampsia, both of which place patients at higher risk for other obstetric complications. The cesarean section rate was significantly higher than the national rate of 31.8% (p=0.0017). Understanding common complications in our changing population will better equip providers to care for these patients; providing these data also creates a resource for other researchers

    Hospital-Level NICU Capacity, Utilization, and 30-Day Outcomes in Texas

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    IMPORTANCE: Risk-adjusted neonatal intensive care unit (NICU) utilization and outcomes vary markedly across regions and hospitals. The causes of this variation are poorly understood. OBJECTIVE: To assess the association of hospital-level NICU bed capacity with utilization and outcomes in newborn cohorts with differing levels of health risk. DESIGN, SETTING, AND PARTICIPANTS: This population-based retrospective cohort study included all Medicaid-insured live births in Texas from 2010 to 2014 using linked vital records and maternal and newborn claims data. Participants were Medicaid-insured singleton live births (LBs) with birth weights of at least 400 g and gestational ages between 22 and 44 weeks. Newborns were grouped into 3 cohorts: very low birth weight (VLBW; \u3c1500 \u3eg), late preterm (LPT; 34-36 weeks\u27 gestation), and nonpreterm newborns (NPT; ≥37 weeks\u27 gestation). Data analysis was conducted from January 2022 to October 2023. EXPOSURE: Hospital NICU capacity measured as reported NICU beds/100 LBs, adjusted (ie, allocated) for transfers. MAIN OUTCOMES AND MEASURES: NICU admissions and special care days; inpatient mortality and 30-day postdischarge adverse events (ie, mortality, emergency department visit, admission, observation stay). RESULTS: The overall cohort of 874 280 single LBs included 9938 VLBW (5054 [50.9%] female; mean [SD] birth weight, 1028.9 [289.6] g; mean [SD] gestational age, 27.6 [2.6] wk), 63 160 LPT (33 684 [53.3%] female; mean [SD] birth weight, 2664.0 [409.4] g; mean [SD] gestational age, 35.4 [0.8] wk), and 801 182 NPT (407 977 [50.9%] female; mean [SD] birth weight, 3318.7 [383.4] g; mean [SD] gestational age, 38.9 [1.0] wk) LBs. Median (IQR) NICU capacity was 0.84 (0.57-1.30) allocated beds/100 LB/year. For VLBW newborns, NICU capacity was not associated with the risk of NICU admission or number of special care days. For LPT newborns, birth in hospitals with the highest compared with the lowest category of capacity was associated with a 17% higher risk of NICU admission (adjusted risk ratio [aRR], 1.17; 95% CI, 1.01-1.33). For NPT newborns, risk of NICU admission was 55% higher (aRR, 1.55; 95% CI, 1.22-1.97) in the highest- vs the lowest-capacity hospitals. The number of special care days for LPT and NPT newborns was 21% (aRR, 1.21; 95% CI,1.08-1.36) and 37% (aRR, 1.37; 95% CI, 1.08-1.74) higher in the highest vs lowest capacity hospitals, respectively. Among LPT and NPT newborns, NICU capacity was associated with higher inpatient mortality and 30-day postdischarge adverse events. CONCLUSIONS AND RELEVANCE: In this cohort study of Medicaid-insured newborns in Texas, greater hospital NICU bed supply was associated with increased NICU utilization in newborns born LPT and NPT. Higher capacity was not associated with lower risk of adverse events. These findings raise important questions about how the NICU is used for newborns with lower risk

    Hospital-Level Nicu Capacity, Utilization, and 30-Day Outcomes in Texas

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    IMPORTANCE: Risk-adjusted neonatal intensive care unit (NICU) utilization and outcomes vary markedly across regions and hospitals. The causes of this variation are poorly understood. OBJECTIVE: to assess the association of hospital-level NICU bed capacity with utilization and outcomes in newborn cohorts with differing levels of health risk. DESIGN, SETTING, AND PARTICIPANTS: This population-based retrospective cohort study included all Medicaid-insured live births in Texas from 2010 to 2014 using linked vital records and maternal and newborn claims data. Participants were Medicaid-insured singleton live births (LBs) with birth weights of at least 400 g and gestational ages between 22 and 44 weeks. Newborns were grouped into 3 cohorts: very low birth weight (VLBW; \u3c1500 \u3eg), late preterm (LPT; 34-36 weeks\u27 gestation), and nonpreterm newborns (NPT; ≥37 weeks\u27 gestation). Data analysis was conducted from January 2022 to October 2023. EXPOSURE: Hospital NICU capacity measured as reported NICU beds/100 LBs, adjusted (ie, allocated) for transfers. MAIN OUTCOMES AND MEASURES: NICU admissions and special care days; inpatient mortality and 30-day postdischarge adverse events (ie, mortality, emergency department visit, admission, observation stay). RESULTS: The overall cohort of 874 280 single LBs included 9938 VLBW (5054 [50.9%] female; mean [SD] birth weight, 1028.9 [289.6] g; mean [SD] gestational age, 27.6 [2.6] wk), 63 160 LPT (33 684 [53.3%] female; mean [SD] birth weight, 2664.0 [409.4] g; mean [SD] gestational age, 35.4 [0.8] wk), and 801 182 NPT (407 977 [50.9%] female; mean [SD] birth weight, 3318.7 [383.4] g; mean [SD] gestational age, 38.9 [1.0] wk) LBs. Median (IQR) NICU capacity was 0.84 (0.57-1.30) allocated beds/100 LB/year. For VLBW newborns, NICU capacity was not associated with the risk of NICU admission or number of special care days. For LPT newborns, birth in hospitals with the highest compared with the lowest category of capacity was associated with a 17% higher risk of NICU admission (adjusted risk ratio [aRR], 1.17; 95% CI, 1.01-1.33). For NPT newborns, risk of NICU admission was 55% higher (aRR, 1.55; 95% CI, 1.22-1.97) in the highest- vs the lowest-capacity hospitals. The number of special care days for LPT and NPT newborns was 21% (aRR, 1.21; 95% CI,1.08-1.36) and 37% (aRR, 1.37; 95% CI, 1.08-1.74) higher in the highest vs lowest capacity hospitals, respectively. Among LPT and NPT newborns, NICU capacity was associated with higher inpatient mortality and 30-day postdischarge adverse events. CONCLUSIONS AND RELEVANCE: In this cohort study of Medicaid-insured newborns in Texas, greater hospital NICU bed supply was associated with increased NICU utilization in newborns born LPT and NPT. Higher capacity was not associated with lower risk of adverse events. These findings raise important questions about how the NICU is used for newborns with lower risk

    Assessment of Corticosteroid Therapy and Death or Disability According to Pretreatment Risk of Death or Bronchopulmonary Dysplasia in Extremely Preterm Infants

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    IMPORTANCE: Meta-analyses suggest that corticosteroids may be associated with increased survival without cerebral palsy in infants at high risk of bronchopulmonary dysplasia (BPD) but are associated with adverse neurologic outcomes in low-risk infants. Whether this association exists in contemporary practice is uncertain because most randomized clinical trials administered corticosteroids earlier and at higher doses than currently recommended. OBJECTIVE: To evaluate whether the pretreatment risk of death or grade 2 or 3 BPD at 36 weeks\u27 postmenstrual age modified the association between postnatal corticosteroid therapy and death or disability at 2 years\u27 corrected age in extremely preterm infants. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed data on 482 matched pairs of infants from 45 participating US hospitals in the National Institute of Child Health and Human Development Neonatal Research Network Generic Database (GDB). Infants were included in the cohort if they were born at less than 27 weeks\u27 gestation between April 1, 2011, and March 31, 2017; survived the first 7 postnatal days; and had 2-year death or developmental follow-up data collected between January 2013 and December 2019. Corticosteroid-treated infants were propensity score matched with untreated controls. Data were analyzed from September 1, 2019, to November 30, 2022. EXPOSURE: Systemic corticosteroid therapy to prevent BPD that was initiated between day 8 and day 42 after birth. MAIN OUTCOMES AND MEASURES: The primary outcome was death or moderate to severe neurodevelopmental impairment at 2 years\u27 corrected age. The secondary outcome was death or moderate to severe cerebral palsy at 2 years\u27 corrected age. RESULTS: A total of 482 matched pairs of infants (mean [SD] gestational age, 24.1 [1.1] weeks]; 270 males [56.0%]) were included from 656 corticosteroid-treated infants and 2796 potential controls. Most treated infants (363 [75.3%]) received dexamethasone. The risk of death or disability associated with corticosteroid therapy was inversely associated with the estimated pretreatment probability of death or grade 2 or 3 BPD. The risk difference for death or neurodevelopmental impairment associated with corticosteroids decreased by 2.7% (95% CI, 1.9%-3.5%) for each 10% increase in the pretreatment risk of death or grade 2 or 3 BPD. This risk transitioned from estimated net harm to benefit when the pretreatment risk of death or grade 2 or 3 BPD exceeded 53% (95% CI, 44%-61%). For death or cerebral palsy, the risk difference decreased by 3.6% (95% CI, 2.9%-4.4%) for each 10% increase in the risk of death or grade 2 or 3 BPD and transitioned from estimated net harm to benefit at a pretreatment risk of 40% (95% CI, 33%-46%). CONCLUSIONS AND RELEVANCE: Results of this study suggested that corticosteroids were associated with a reduced risk of death or disability in infants at moderate to high pretreatment risk of death or grade 2 or 3 BPD but with possible harm in infants at lower risk

    Use of term reference infants in assessing the developmental outcome of extremely preterm infants: lessons learned in a multicenter study.

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    OBJECTIVE: Extremely preterm (EP) impairment rates are likely underestimated using the Bayley III norm-based thresholds scores and may be better assessed relative to concurrent healthy term reference (TR) infants born in the same hospital. STUDY DESIGN: Blinded, certified examiners in the Neonatal Research Network (NRN) evaluated EP survivors and a sample of healthy TR infants recruited near the 2-year assessment age. RESULTS: We assessed 1452 EP infants and 183 TR infants. TR-based thresholds showed higher overall EP impairment than Bayley norm-based thresholds (O.R. = 1.86; [95% CI 1.56-2.23], especially for severe impairment (36% vs. 24%; p ≤ 0.001). Difficulty recruiting TR patients at 2 years extended the study by 14 months and affected their demographics. CONCLUSION: Impairment rates among EP infants appear to be substantially underestimated from Bayley III norms. These rates may be best assessed by comparison with healthy term infants followed with minimal attrition from birth in the same centers

    Muon-induced background in the KATRIN main spectrometer

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    The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to make a model-independent determination of the effective electron antineutrino mass with a sensitivity of 0.2 eV/c2. It investigates the kinematics of -particles from tritium -decay close to the endpoint of the energy spectrum. Because the KATRIN main spectrometer (MS) is located above ground, muon-induced backgrounds are of particular concern. Coincidence measurements with the MS and a scintillator-based muon detector system confirmed the model of secondary electron production by cosmic-ray muons inside the MS. Correlation measurements with the same setup showed that about 12% of secondary electrons emitted from the inner surface are induced by cosmic-ray muons, with approximately one secondary electron produced for every 17 muon crossings. However, the magnetic and electrostatic shielding of the MS is able to efficiently suppress these electrons, and we find that muons are responsible for less than 17% (90% confidence level) of the overall MS background

    First transmission of electrons and ions through the KATRIN beamline

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    The Karlsruhe Tritium Neutrino (KATRIN) experiment is a large-scale effort to probe the absolute neutrino mass scale with a sensitivity of 0.2 eV (90% confidence level), via a precise measurement of the endpoint spectrum of tritium β-decay. This work documents several KATRIN commissioning milestones: the complete assembly of the experimental beamline, the successful transmission of electrons from three sources through the beamline to the primary detector, and tests of ion transport and retention. In the First Light commissioning campaign of autumn 2016, photoelectrons were generated at the rear wall and ions were created by a dedicated ion source attached to the rear section; in July 2017, gaseous 83mKr was injected into the KATRIN source section, and a condensed 83mKr source was deployed in the transport section. In this paper we describe the technical details of the apparatus and the configuration for each measurement, and give first results on source and system performance. We have successfully achieved transmission from all four sources, established system stability, and characterized many aspects of the apparatus
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