Association of the location of pancreatic ductal adenocarcinoma (head, body, tail) with tumor stage, treatment, and survival: a population-based analysis

Background: The association between pancreatic ductal adenocarcinoma (PDAC) location (head, body, tail) and tumor stage, treatment and overall survival (OS) is unclear. Methods: Patients with PDAC diagnosed between 2005 and 2015 were included from the population-based Netherlands Cancer Registry. Patient, tumor and treatment characteristics were compared with the tumor locations. Multivariable logistic and Cox regression analyses were used. Results: Overall, 19,023 patients were included. PDAC locations were 13,451 (71%) head, 2429 (13%) body and 3143 (16%) tail. Differences were found regarding metastasized disease (head 42%, body 69%, tail 84%, p 4 cm: 21%, 40%, 51%, p <.001) and resection rate (17%, 4%, 7%, p <.001). For patients without metastases, median OS did not differ between head, body, tail (after resection: 16.8, 15.0, 17.3 months, without resection: 5.2, 6.1, 4.6 months, respectively). For patients with metastases, median OS differed slightly (2.6, 2.4, 1.9 months, respectively, adjusted HR body versus head 1.17 (95%CI 1.10–1.23), tail versus head 1.35 (95%CI 1.29–1.41)). Conclusions: PDAC locations in body and tail are larger, more often metastasized and less often resectable than in the pancreatic head. Whereas survival is similar after resection, survival in metastasized disease is somewhat less for PDAC in the pancreatic body and tail

The design, implementation, and performance of the LZ calibration systems

LUX-ZEPLIN (LZ) is a tonne-scale experiment searching for direct dark matter interactions and other rare events. It is located at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. The core of the LZ detector is a dual-phase xenon time projection chamber (TPC), designed with the primary goal of detecting Weakly Interacting Massive Particles (WIMPs) via their induced low energy nuclear recoils. Surrounding the TPC, two veto detectors immersed in an ultra-pure water tank enable reducing background events to enhance the discovery potential. Intricate calibration systems are purposely designed to precisely understand the responses of these three detector volumes to various types of particle interactions and to demonstrate LZ's ability to discriminate between signals and backgrounds. In this paper, we present a comprehensive discussion of the key features, requirements, and performance of the LZ calibration systems, which play a crucial role in enabling LZ's WIMP-search and its broad science program. The thorough description of these calibration systems, with an emphasis on their novel aspects, is valuable for future calibration efforts in direct dark matter and other rare-event search experiments

New constraints on ultraheavy dark matter from the LZ experiment

Searches for dark matter with liquid xenon time projection chamber experiments have traditionally focused on the region of the parameter space that is characteristic of weakly interacting massive particles, ranging from a few GeV/c2 to a few TeV/c2. Models of dark matter with a mass much heavier than this are well motivated by early production mechanisms different from the standard thermal freeze-out, but they have generally been less explored experimentally. In this work, we present a reanalysis of the first science run of the LZ experiment, with an exposure of 0.9  tonne×yr, to search for ultraheavy particle dark matter. The signal topology consists of multiple energy deposits in the active region of the detector forming a straight line, from which the velocity of the incoming particle can be reconstructed on an event-by-event basis. Zero events with this topology were observed after applying the data selection calibrated on a simulated sample of signal-like events. New experimental constraints are derived, which rule out previously unexplored regions of the dark matter parameter space of spin-independent interactions beyond a mass of 1017  GeV/c2. Published by the American Physical Society 2024 </jats:sec

Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×109 protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10 GV and ∼20 GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.</p

Needle electromyographic findings in 98 patients with myositis.

Item does not contain fulltextBACKGROUND/AIMS: Little is known about the distribution of electromyographic (EMG) abnormalities in myositis even though this is relevant in daily practice. METHODS: A retrospective semiquantitative analysis of needle EMG findings was performed in a group of 98 patients with myositis. The frequency, type, and distribution of abnormalities were studied. The influence of the use of corticosteroids and the stage of the disease were evaluated. RESULTS: In most patients, a myopathic pattern with spontaneous activity was found, although several clinically relevant exceptions were noted. Long-duration motor unit potentials were found in all three diagnostic groups and were not associated with disease duration. In the lower extremity a distal to proximal gradient was present, adding to the diagnostic confusion with neurogenic diseases, and spontaneous activity was absent in a relatively large group although none of the patients in the acute stage of the disease had a normal EMG. The use of corticosteroids reduced the number of abnormal findings in dermatomyositis and polymyositis, but not in inclusion body myositis. CONCLUSION: A myopathic pattern with spontaneous activity was most frequently found, although several clinically relevant exceptions were noted. These results illustrate the spectrum of EMG findings in myositis, and may aid the clinician in the interpretation of the EMG in these patients