COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Analysis of MOS capacitor with p layer with TCAD simulation

The ATLAS18 strip sensors of the ATLAS inner tracker upgrade (ITk) are in production since 2021. Along with the large-format n$^+$-in-p strip sensor in the center of 6-inch wafer, test structures are laid out in the open space for monitoring the performance of the strip sensor and its fabrication process. One of the structures is a 1.2$\times$1.0 cm$^2$ test chip that includes representative structures of the strips, and Metal-Oxide-Silicon (MOS) capacitors. In addition to the standard MOS capacitor, a MOS capacitor is designed with a p-implantation in the surface of silicon, representative of the p-stop doping for isolating the n$^+$ strips, the MOS-p capacitor. The capacitance measurement of the standard MOS capacitor as a function of bias voltage (C-V) shows characteristic behavior in the accumulation, depletion, and inversion regimes, from which one can deduce the amount of the interface charge. The MOS-p capacitor shows the C-V behavior modulated by the properties of the p-layer. With over 50% of the full production complement delivered, we have observed consistent characteristics in the MOS-p capacitors. Rarely and currently only in three batches, we have observed abnormalities which have implied lower density of p-implantation in the p-layer. To study the cause, we have simulated the MOS-p capacitor with a TCAD software, which successfully reproduces the normal behavior, with the p-density and the interface charge within the expected ranges, including a feature caused by a geometrical offset of the areas of the metal and the p-implantation. By contrast, overall shapes of the abnormal cases are only reproduced when introducing 1/10 of p-density, larger interface charge, charge traps in the p-layer, and/or n-type surface contamination. A smaller but distinctive feature in the C-V behavior might also be caused by non-uniform distribution of these or other components. These simulations help to take final acceptance decisions for the batches in production

Analysis of MOS capacitor with p-layer with TCAD simulation

The ATLAS18 strip sensors of the ATLAS inner tracker upgrade (ITk) are under production since 2021. Along with the large-format n^+-in-p strip sensor in the center of the wafer, test structures are laid out in the open space for monitoring the performance of the strip sensor and its fabrication process. One of the structures is a 1.2×1.0 mm^2 test chip that includes representative structures of the strips, and Metal-Oxide-Silicon (MOS) capacitors. In addition to the standard MOS capacitor, a MOS capacitor with a p-layer in the surface of silicon, the MOS-p capacitor, is designed with a p-density representative of the p-stop doping for isolating the n+ strips. The C-V curve of the MOS capacitor shows characteristic behavior in the accumulation, depletion, and inversion regions as a function of bias voltage, from which one can estimate the amount of the interface charge. The MOS-p capacitor shows the C-V curve modulated by the properties of the p-layer. With over 50% of the full production complement delivered, we have observed consistent characteristics in the MOS-p capacitors. Rarely and currently only in 3 batches, we have observed abnormalities. To further study them, we have simulated the MOS-p capacitor with TCAD software, which successfully reproduces the normal behavior, including a feature caused by a geometrical setback of the p-layer to the metal area, with the p-density and the interface charge within the expected range. By contrast, the overall shapes of the abnormal cases are only reproduced with 1/10 of the p-density to the specification and possible charge traps in the p-layer area. A smaller but distinctive feature in the behavior may require a non-uniform distribution of the p-density and the interface charge or something else. These simulations help to take final decisions for the batches in production

Supporting Sustainability of Chemistry by Linking Research Data with Physically Preserved Research Materials

Results of scientific work in chemistry can usually be obtained in the form of materials and data. A big step towards transparency and reproducibility of the scientific work can be gained if scientists publish their data in a FAIR (Findable, Accessible, Interoperable, Reusable) manner in research data repositories. Nevertheless, in order to make chemistry as a discipline sustainable, obtaining FAIR data is insufficient and a comprehensive concept including the preservation of materials is needed. We describe in this article how we combined two infrastructures, a repository for research data (Chemotion repository) and an archive for chemical compounds (Molecule Archive), in order to offer a comprehensive infrastructure to find and access data and materials that were generated in chemistry projects. Samples play a key role in this concept: we describe how FAIR metadata of a virtual sample representation can be used to refer to the physically available sample stored in a materials’ archive and to link FAIR research data gained with the sample. We further describe the measures to make the physically available samples not only FAIR through the sample’s metadata but also accessible and reusable in the form of their material for others

Monitoring Quality of ATLAS ITk Strip Sensors/wafers through Database

High-Luminosity LHC upgrade necessitated a complete replacement of the ATLAS Inner Detector with a larger all-silicon tracker. The strip portion of it covers 165 m2 area, afforded by the strip sensors. Following several prototype iterations and a successful pre-production, a full-scale production started in 2021, to finish by the beginning of 2025. It will include over 20,000 wafers and a factor of 5 higher throughput than pre-production, with about 500 sensors produced and tested per month. The transition to production stressed the need to evaluate the results from the Quality Control (QC) and Quality Assurance (QA) tests quickly to meet the monthly delivery schedule. The test data come from 15 collaborating institutes, therefore a highly distributed system with standardized interfaces was required. Specialized software layers of QA and QC Python code were developed against the backend of ITkdatabase (DB) for this purpose. The developments included particularities and special needs of the Strip Sensors community, such as the large variety of different test devices and test types, the necessary test formats, and different workflows at the test sites. Special attention was paid to techniques facilitating the development and user operations, for example creation of “parallel” set of dummy DB objects for practice purpose, iterative verification of operability, and the automatic upload of test data. The scalability concerns, and automation of the data handling were included in the system architecture from the very inception. The full suite of functionalities include data integrity checks, data processing to extract and evaluate key parameters, cross-test comparisons, and summary reporting for continuous monitoring. We will also describe the lessons learned and the necessary evolution of the system

Characterization of the Polysilicon Resistor in Silicon Strip Sensors for ATLAS Inner Tracker as a Function of Temperature, Pre- And Post-Irradiation

The high luminosity upgrade of the Large Hadron Collider, foreseen for 2029, requires the replacement of the ATLAS Inner Detector with a new all-silicon Inner Tracker (ITk). The expected total integrated luminosity of $4000\, \mathrm{fb}^{−1}$ means that the strip part of the ITk detector will be exposed to the total particle fluences and ionizing doses reaching the values of $1.6 \cdot 10^{15}$ $1\, \mathrm{MeV}$ $\mathrm{n_{eq}/cm^2}$ and $0.66\, \mathrm{MGy}$, respectively, including a safety factor of $1.5$. Radiation hard n${}^+$-in-p micro-strip sensors were developed by the ATLAS ITk strip collaboration and are produced by Hamamatsu Photonics K.K. The active area of each ITk strip sensor is delimited by the n-implant bias ring, which is connected to each individual n${}^+$ implant strip by a polysilicon bias resistor. The total resistance of the polysilicon bias resistor should be within a specified range to keep all the strips at the same potential, prevent the signal discharge through the grounded bias ring and avoid the readout noise increase. While the polysilicon is a ubiquitous semiconductor material, the fluence and temperature dependence of its resistance is not easily predictable, especially for the tracking detector with the operational temperature significantly below the values typical for commercial microelectronics. Dependence of the resistance of polysilicon bias resistor on the temperature, as well as on the total delivered fluence and ionizing dose, was studied on the specially-designed test structures called ATLAS Testchips, both before and after their irradiation by protons, neutrons, and gammas to the maximal expected fluence and ionizing dose. The resistance has an atypical negative temperature dependence. It is different from silicon, which shows that the grain boundary has a significant contribution to the resistance. We will discuss the contributions by parameterizing the excitation energy of the polysilicon resistance as a function of the temperature for unirradiated and irradiated ATLAS Testchips

Analysis of the Quality Assurance results from the initial part of production of the ATLAS18 ITk strip sensors

The production of strip sensors for the ATLAS Inner Tracker (ITk) started in 2021. Since then, a Quality Assurance (QA) program has been carried out continuously, by using specific test structures, in parallel to the Quality Control (QC) inspection of the sensors. The QA program consists of monitoring sensor-specific characteristics and the technological process variability, before and after the irradiation with gammas, neutrons, and protons. After two years, half of the full production volume has been reached and we present an analysis of the parameters measured as part of the QA process. The main devices used for QA purposes are miniature strip sensors, monitor diodes, and the ATLAS test chip, which contains several test structures. Such devices are tested by several sites across the collaboration depending on the type of samples (non-irradiated components or irradiated with protons, neutrons, or gammas). The parameters extracted from the tests are then uploaded to a database and analyzed by Python scripts. These parameters are mainly examined through histograms and time-evolution plots to obtain parameter distributions, production trends, and meaningful parameter-to-parameter correlations. The purpose of this analysis is to identify possible deviations in the fabrication or the sensor quality, changes in the behavior of the test equipment at different test sites, or possible variability in the irradiation processes. The conclusions extracted from the QA program have allowed test optimization, establishment of control limits for the parameters, and a better understanding of device properties and fabrication trends. In addition, any abnormal results prompt immediate feedback to the vendor

Characterization of the Polysilicon Resistor in Silicon Strip Sensors for ATLAS Inner Tracker as a Function of Temperature, Pre- And Post-Irradiation

The high luminosity upgrade of the Large Hadron Collider, foreseen for $2029$, requires the replacement of the ATLAS Inner Detector with a new all-silicon Inner Tracker (ITk). The expected ultimate total integrated luminosity of $4000\, \mathrm{fb}^{-1}$ means that the strip part of the ITk detector will be exposed to the total particle fluences and ionizing doses reaching the values of $1.6 \cdot 10^{15}$ $1\, \mathrm{MeV}$ $\mathrm{n_{eq}/cm^2}$ and $0.66\, \mathrm{MGy}$, respectively, including a safety factor of $1.5$. Radiation hard n${}^+$-in-p micro-strip sensors were developed by the ATLAS ITk strip collaboration and are produced by Hamamatsu Photonics K.K. The active area of each ITk strip sensor is delimited by the n-implant bias ring, which is connected to each individual n${}^+$ implant strip by a polysilicon bias resistor. The total resistance of the polysilicon bias resistor should be within a specified range to keep all the strips at the same potential, prevent the signal discharge through the grounded bias ring and avoid the readout noise increase. While the polysilicon is a ubiquitous semiconductor material, the fluence and temperature dependence of its resistance is not easily predictable, especially for the tracking detector with the operational temperature significantly below the values typical for commercial microelectronics. Dependence of the resistance of polysilicon bias resistor on the temperature, as well as on the total delivered fluence and ionizing dose, was studied on the specially-designed test structures called ATLAS Testchips, both before and after their irradiation by protons, neutrons, and gammas to the maximal expected fluence and ionizing dose. The resistance has an atypical negative temperature dependence. It is different from silicon, which shows that the grain boundary has a significant contribution to the resistance. We will discuss the contributions by parameterizing the activation energy of the polysilicon resistance as a function of the temperature for unirradiated and irradiated ATLAS Testchips

Monitoring Quality of ATLAS ITk Strip Sensors through Database

The high-Luminosity LHC upgrade necessitates a complete replacement of the ATLAS Inner Detector with a larger all-silicon tracker. The strip portion of it covers 165 m$^2$ area, afforded by the strip sensors. Following several prototype iterations and a successful pre-production, a full-scale production started in 2021, to finish in 2025. It will include about 21,000 wafers and a factor of 5 higher throughput than pre-production, with about 500 sensors produced and tested per month. The transition to production stressed the need to evaluate the results from the Quality Control (QC) and Quality Assurance (QA) tests quickly to meet the monthly delivery schedule. The test data come from 15 collaborating institutes, therefore a highly distributed system with standardized interfaces was required. Specialized software layers of QA and QC Python code were developed against the backend of the ITk database (DB) for this purpose. The developments included particularities and special needs of the Strip Sensors community, such as the large variety of different test devices and test types, the necessary test formats, and different workflows at the test sites. Special attention was paid to techniques facilitating the development and user operations, for example creation of “parallel” sets of dummy DB objects for practice purposes, iterative verification of operability, and the automatic upload of test data. The scalability concerns and automation of the data handling were included in the system architecture from the very inception. The full suite of functionalities include data integrity checks, data processing to extract and evaluate key parameters, cross-test comparisons, and summary reporting for continuous monitoring. We will also describe the lessons learned and the necessary evolution of the system

ATLAS ITk strip sensor quality assurance tests and results of ATLAS18 pre-production sensors

Towards the high luminosity (HL) operation of the Large Hadron Collider (LHC), the inner tracking system of the ATLAS detector is replaced by a fully silicon-based inner tracker (ITk). Its outer region consists of 17,888 $n^+$-in-$p$ silicon strip sensors. In order to confirm key properties of the production sensors as well as to establish a solid workflow of quality inspection and monitoring of the various sensor properties, about 5\% of the total strip sensors were produced in 2020 as a pre-production run. As a quality assurance (QA) program, irradiation of dedicated QA test pieces was periodically performed. The fluences of proton, neutron and $\gamma$-ray irradiations were up to $1.6 \times 10^{15}$ 1-MeV neutrons$/\mathrm{cm}^2$ and 0.66 MGy, which are equivalent to the maximum expected radiation fluences at the HL-LHC operation with a safety factor of 1.5. Results from 154 QA test pieces demonstrated high quality of the strip sensors through the pre-production. Detailed understanding of post-irradiated strip sensors was acquired, and the procedures of irradiation and post-irradiation QA testing were fully established. Consequently, the 3.8-year project of the strip sensor production for the ATLAS ITk detector was initiated in July 2021