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By directly altering microscopic interactions, pressure provides a powerful tuning knob for the exploration of condensed phases and geophysical phenomena1. The megabar regime represents an interesting frontier, in which recent discoveries include high-temperature superconductors, as well as structural and valence phase transitions2-6. However, at such high pressures, many conventional measurement techniques fail. Here we demonstrate the ability to perform local magnetometry inside a diamond anvil cell with sub-micron spatial resolution at megabar pressures. Our approach uses a shallow layer of nitrogen-vacancy colour centres implanted directly within the anvil7-9; crucially, we choose a crystal cut compatible with the intrinsic symmetries of the nitrogen-vacancy centre to enable functionality at megabar pressures. We apply our technique to characterize a recently discovered hydride superconductor, CeH9 (ref. 10). By performing simultaneous magnetometry and electrical transport measurements, we observe the dual signatures of superconductivity: diamagnetism characteristic of the Meissner effect and a sharp drop of the resistance to near zero. By locally mapping both the diamagnetic response and flux trapping, we directly image the geometry of superconducting regions, showing marked inhomogeneities at the micron scale. Our work brings quantum sensing to the megabar frontier and enables the closed-loop optimization of superhydride materials synthesis.
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High-precision hyperfine structure measurements were performed on stable, singly-charged [Formula: see text]Co ions at the IGISOL facility in Jyväskylä, Finland using the collinear laser spectroscopy technique. A newly installed light collection setup enabled the study of transitions in the 230 nm wavelength range from low-lying states below 6000 cm[Formula: see text]. We report a 100-fold improvement on the precision of the hyperfine A parameters, and furthermore present newly measured hyperfine B paramaters.
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Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly volatile and the least reactive member of group 14. Our experimental observations suggest that Fl exhibits lower reactivity towards Au than the volatile metal Hg, but higher reactivity than the noble gas Rn.
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Nihonium (Nh, element 113) and flerovium (Fl, element 114) are the first superheavy elements in which the 7p shell is occupied. High volatility and inertness were predicted for Fl due to the strong relativistic stabilization of the closed 7p 1/2 sub-shell, which originates from a large spin-orbit splitting between the 7p 1/2 and 7p 3/2 orbitals. One unpaired electron in the outermost 7p 1/2 sub-shell in Nh is expected to give rise to a higher chemical reactivity. Theoretical predictions of Nh reactivity are discussed, along with results of the first experimental attempts to study Nh chemistry in the gas phase. The experimental observations verify a higher chemical reactivity of Nh atoms compared to its neighbor Fl and call for the development of advanced setups. First tests of a newly developed detection device miniCOMPACT with highly reactive Fr isotopes assure that effective chemical studies of Nh are within reach.
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BACKGROUND: The standard treatment for Hinchey III perforated diverticulitis with peritonitis was resection with or without a stoma, but recent trials have shown that laparoscopic lavage is a reasonable alternative. This registry-based Swedish study investigated results at a national level to assess safety in real-world scenarios. METHODS: Patients in Sweden who underwent emergency surgery for perforated diverticulitis between 2016 and 2018 were studied. Inverse probability weighting by propensity score was used to adjust for confounding factors. RESULTS: A total of 499 patients were included in this study. Laparoscopic lavage was associated with a significantly lower 90-day Comprehensive Complication Index (20.9 versus 32.0; odds ratio 0.77, 95 per cent compatibility interval (c.i.) 0.61 to 0.97) and overall duration of hospital stay (9 versus 15 days; ratio of means 0.84, 95 per cent c.i. 0.74 to 0.96) compared with resection. Patients had 82 (95 per cent c.i. 39 to 140) per cent more readmissions following lavage than resection (27.2 versus 21.0 per cent), but similar reoperation rates. More co-morbidity was noted among patients who underwent resection than those who had laparoscopic lavage. CONCLUSION: Laparoscopic lavage is safe in routine care beyond trial evaluations.
Diverticulitis comprises inflammation in pouches (diverticula) of the large intestine. In the most severe instances, this inflammation can cause perforation of the bowel with purulent or faecal peritonitis. If this happens, surgery is needed. The traditional method has been resection of the inflamed bowel with a stoma. A new technique has been proposed whereby the abdomen is rinsed with saline laparoscopically and a drain is placed (laparoscopic lavage). This study aimed to compare these two methods in terms of clinical short-term outcomes, with a focus on complications. It was found that laparoscopic lavage had fewer complications than resectional surgery and a shorter hospital stay. The new method was safe when used in Swedish routine care.
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Diverticulitis del Colon/cirugía , Perforación Intestinal/cirugía , Laparoscopía , Lavado Peritoneal/métodos , Anciano , Diverticulitis del Colon/complicaciones , Femenino , Humanos , Perforación Intestinal/etiología , Laparoscopía/efectos adversos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Readmisión del Paciente , Lavado Peritoneal/efectos adversos , Complicaciones Posoperatorias , Puntaje de Propensión , Sistema de Registros , Reoperación , Estudios Retrospectivos , Suecia , Resultado del TratamientoRESUMEN
In two recent papers by Pore et al. and Khuyagbaatar et al., discovery of the new isotope ^{244}Md was reported. The decay data, however, are conflicting. While Pore et al. report two isomeric states decaying by α emission with E_{α}(1)=8.66(2) MeV, T_{1/2}(1)=0.4_{-0.1}^{+0.4} s and E_{α}(2)=8.31(2) MeV, T_{1/2}(2)≈6 s, Khuyagbaatar et al. [Phys. Rev. Lett. 125, 142504 (2020).PRLTAO0031-900710.1103/PhysRevLett.125.142504] report only a single transition with a broad energy distribution of E_{α}=(8.73-8.86) MeV and T_{1/2}=0.30_{-0.09}^{+0.19} s. The data published in Pore et al. are very similar to those published for ^{245m}Md [E_{α}=8.64(2), 8.68(2) MeV, T_{1/2}=0.35_{-0.16}^{+0.23} s [V. Ninov, F. P. Heßberger, S. Hofmann, H. Folger, G. Münzenberg, P. Armbruster, A. V. Yeremin, A. G. Popeko, M. Leino, and S. Saro, Z. Phys. A 356, 11 (1996).ZPAHEX0939-792210.1007/s002180050141] ]. Therefore, we compare the data presented for ^{244}Md in Pore et al. with those reported for ^{245}Md in Ninov et al. and also in Khuyagbaatar et al. We conclude that the data presented in Pore et al. shall be attributed to ^{245}Md with small contributions (one event each) from ^{245}Fm and probably ^{246}Md.
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A nuclear spectroscopy experiment was conducted to study α-decay chains stemming from isotopes of flerovium (element Z=114). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions ^{48}Ca+^{242}Pu and ^{48}Ca+^{244}Pu provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to ^{286}Fl and ^{288}Fl, respectively. A prompt coincidence between a 9.60(1)-MeV α particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely ^{282}Cn. Spectroscopy of ^{288}Fl decay chains fixed Q_{α}=10.06(1) MeV. In one case, a Q_{α}=9.46(1)-MeV decay from ^{284}Cn into ^{280}Ds was observed, with ^{280}Ds fissioning after only 518 µs. The impact of these findings, aggregated with existing data on decay chains of ^{286,288}Fl, on the size of an anticipated shell gap at proton number Z=114 is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.
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The electron-capture decay followed by a prompt fission process was searched for in the hitherto unknown most neutron-deficient Md isotope with mass number 244. Alpha decay with α-particle energies of 8.73-8.86 MeV and with a half-life of 0.30_{-0.09}^{+0.19} s was assigned to ^{244}Md. No fission event with a similar half-life potentially originating from spontaneous fissioning of the short-lived electron-capture decay daughter ^{244}Fm was observed, which results in an upper limit of 0.14 for the electron-capture branching of ^{244}Md. Two groups of fission events with half-lives of 0.9_{-0.3}^{+0.6} ms and 5_{-2}^{+3} ms were observed. The 0.9_{-0.3}^{+0.6} ms activity was assigned to originate from the decay of ^{245}Md. The origin of eight fission events resulting in a half-life of 5_{-2}^{+3} ms could not be unambiguously identified within the present data while the possible explanation has to invoke previously unseen physics cases.
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We report on cyclotron frequency measurements on trapped 206,207Pb+ ions by means of the non-destructive Fourier-transform ion-cyclotron-resonance technique at room temperature. In a proof-of-principle experiment using a quartz crystal instead of a coil as a resonator, we have alternately carried out cyclotron frequency measurements for 206Pb+ and 207Pb+ with the sideband coupling method to obtain 21 cyclotron-frequency ratios with a statistical uncertainty of 6 × 10-7. The mean frequency ratio R¯ deviates by about 2σ from the value deduced from the masses reported in the latest Atomic Mass Evaluation. We anticipate that this shift is due to the ion-ion interaction between the simultaneously trapped ions (≈100) and will decrease to a negligible level once we reach single-ion sensitivity. The compactness of such a crystal makes this approach promising for direct Penning-trap mass measurements on heavy and superheavy elements.
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BACKGROUND AND AIMS: Colectomy due to ulcerative colitis is associated with complications. One severe complication is the risk for blow-out of the remaining rectal remnant. The aim of this study was to compare the frequency and severity of complications in patients with the rectal remnant left subcutaneously versus patients with the rectal remnant left intra-abdominally. A secondary aim was to identify risk factors for complications. MATERIALS AND METHODS: Consecutive patients at two tertiary centers in Sweden were retrospectively reviewed regarding surgical procedures; complications classified according to Clavien-Dindo; and possible risk factors for complications such as preoperative medication, emergency surgery, and body mass index. RESULTS: 307 patients were identified. Minor complications were more common than previously reported (85%-89%). Severe surgical complications were not related to the handling of the rectal remnant. Leaving the rectal remnant subcutaneously was associated with local wound problems. Risk factors for severe complications were emergency surgery and preoperative medication with 5-aminosalicylic acid. CONCLUSION: Minor complications after colectomy for ulcerative colitis are very common and need to be addressed. Leaving the rectal stump intra-abdominally seems safe and may be advantageous to reduce local wound morbidity.
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Colectomía/métodos , Colitis Ulcerosa/cirugía , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Recto/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Recto/patología , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento , Adulto JovenRESUMEN
Single-ion sensitivity is obtained in precision Penning-trap experiments devoted to light (anti)particles or ions with low mass-to-charge ratios, by adding an inductance coil to an amplifier connected to the trap, both operated at 4 K. However, single-ion sensitivity has not been reached on heavy singly or doubly charged ions. In this publication, we present a new system to reach this point, based on the use of a quartz crystal as an inductance, together with a newly developed broad-band (BB) amplifier. We detect the reduced-cyclotron frequency of 40Ca+ ions stored in a 7-tesla open-ring Penning trap. By comparing the detected electric signal obtained with the BB amplifier and the fluorescence signal obtained by collecting the photons emitted by a trapped ion cloud, we show a detection limit below 110 ions. Adding the crystal, the electrical signal increases by a factor of about 30 at room temperature, which combined with the measured equivalent resistance and voltage noise, proves the feasibility of the system to reach single-ion sensitivity at 4 K.
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One of the most important atomic properties governing an element's chemical behavior is the energy required to remove its least-bound electron, referred to as the first ionization potential. For the heaviest elements, this fundamental quantity is strongly influenced by relativistic effects which lead to unique chemical properties. Laser spectroscopy on an atom-at-a-time scale was developed and applied to probe the optical spectrum of neutral nobelium near the ionization threshold. The first ionization potential of nobelium is determined here with a very high precision from the convergence of measured Rydberg series to be 6.626 21±0.000 05 eV. This work provides a stringent benchmark for state-of-the-art many-body atomic modeling that considers relativistic and quantum electrodynamic effects and paves the way for high-precision measurements of atomic properties of elements only available from heavy-ion accelerator facilities.
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Until recently, ground-state nuclear moments of the heaviest nuclei could only be inferred from nuclear spectroscopy, where model assumptions are required. Laser spectroscopy in combination with modern atomic structure calculations is now able to probe these moments directly, in a comprehensive and nuclear-model-independent way. Here we report on unique access to the differential mean-square charge radii of ^{252,253,254}No, and therefore to changes in nuclear size and shape. State-of-the-art nuclear density functional calculations describe well the changes in nuclear charge radii in the region of the heavy actinides, indicating an appreciable central depression in the deformed proton density distribution in ^{252,254}No isotopes. Finally, the hyperfine splitting of ^{253}No was evaluated, enabling a complementary measure of its (quadrupole) deformation, as well as an insight into the neutron single-particle wave function via the nuclear spin and magnetic moment.
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BACKGROUND AND AIMS: Loop ileostomies are frequently used as diversion of the fecal stream to protect a distal anastomosis. The aim of this study was to identify complications and morbidity related to loop ileostomies in patients with ulcerative colitis at a nonemergent setting. MATERIAL AND METHODS: Consecutive patients with ulcerative colitis who received a loop ileostomy at a tertiary referral center in Sweden from January 2006 until December 2012 were included and studied retrospectively. RESULTS: In total, 71 patients were identified, and the median age was 39 years. A majority (94%) of the patients underwent proctectomy or proctocolectomy with primary construction of an ileal pouch-anal anastomosis. In total, 38 patients (54%) had one or more postoperative complications at index surgery. Stoma-related complications were seen in 49% where parastomal skin irritation was most common. In total, 18% of the patients were re-admitted due to morbidity related to the ileostomy, and the leading cause was high volume output. Complications related to closure were seen in 29% of the patients, and of these, 30% required surgical intervention. In total, five patients (7%) developed a symptomatic leakage in the ileo-ileal anastomosis. There was no mortality. CONCLUSION: Loop ileostomies in this young patient cohort resulted in considerable morbidity. Closure of the ileostomy was also associated with complications. Although the diverting loop ileostomy is constructed to decrease the clinical consequences of an anastomotic leakage, the inherent morbidity should be considered. Preventive measures for parastomal skin problems could improve results.
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Colectomía/efectos adversos , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/cirugía , Ileostomía/efectos adversos , Ileostomía/métodos , Complicaciones Posoperatorias/fisiopatología , Adolescente , Adulto , Anastomosis Quirúrgica , Estudios de Cohortes , Colectomía/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Complicaciones Posoperatorias/cirugía , Reoperación/métodos , Estudios Retrospectivos , Medición de Riesgo , Suecia , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
AIM: The aim of this study was to investigate if a delay in a patient's first contact with a healthcare professional, and any subsequent delay in diagnosis, affected self-assessed quality of life prior to start of treatment for rectal cancer. METHOD: Questionnaires were administered when patients had been informed of the diagnosis and planned treatment. The primary end-point was self-assessed quality of life according to a seven-point Likert scale. The response variables were dichotomized and analysed by unadjusted and adjusted binary logistic regression. RESULTS: A reported duration of symptoms longer than 4 months was found to be associated with a lower quality of life than a reported duration of symptoms of less than 3 months. Furthermore, a reported period of longer than 2 months from first contact with a healthcare professional to a diagnosis was found to correlate with lower quality of life compared with a period shorter than 2 months. However, when adjusting for possible confounding variables the duration of symptoms and time to diagnosis were not found to affect self-assessed quality of life. Several variables were found to have significant influence in the statistical model, including sense of coherence, the presence of negative intrusive thoughts, comorbidity, depressed mood, male sex and comorbidity. CONCLUSION: One conclusion of our study is that further efforts to shorten delay in rectal cancer care with the aim of improving quality of life may be futile. To improve the patient's quality of life at diagnosis other interventions should be considered, such as screening for depression and/or negative intrusive thoughts.
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Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Calidad de Vida/psicología , Neoplasias del Recto/psicología , Tiempo de Tratamiento , Anciano , Dinamarca , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias del Recto/terapia , Encuestas y Cuestionarios , Suecia , Factores de TiempoRESUMEN
We extended a generic whole-body physiologically based pharmacokinetic (PBPK) model for rats and humans for organs of the reproductive and endocrine systems (i.e., the testes and the thyroid gland). An extensive literature search was performed, first, to determine the most generic organ model structures for testes and thyroid across species, and, second, to identify the corresponding anatomic and physiological parameters in rats and humans. The testes and thyroid organ models were implemented in the PBPK modeling software PK-Sim and MoBi. The capability of the PBPK approach to simulate the testes and thyroid tissue concentration data was demonstrated using a series of test compounds. The presented organ model structures and parameterization yielded a close agreement between observed and simulated tissue concentrations over time. The organ models are ready to be used to predict the pharmacokinetics of passively entering drugs in the testes and thyroid tissue in a generic PBPK modeling framework.
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Modelos Biológicos , Testículo/química , Glándula Tiroides/química , Animales , Humanos , Masculino , Tamaño de los Órganos , Farmacocinética , Ratas , Programas InformáticosRESUMEN
Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency.
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The aim of this tutorial is to introduce the fundamental concepts of physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) modeling with a special focus on their practical implementation in a typical PBPK model building workflow. To illustrate basic steps in PBPK model building, a PBPK model for ciprofloxacin will be constructed and coupled to a pharmacodynamic model to simulate the antibacterial activity of ciprofloxacin treatment.
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Modelos Biológicos , Farmacocinética , Animales , Simulación por Computador , Humanos , Medición de Riesgo , Distribución TisularRESUMEN
Based on prospective population-based cohort studies from the Netherlands approximately 120,000 sudden cardiac deaths (SCD) have to be assumed in 2014 in Germany for persons older than 55 years of age without an implantable cardioverter defibrillator (ICD). In contrast in 2014 only 30,000 ICD were implanted in Germany. Due to the fact that victims of SCD are difficult to predict many more implantations are actually necessary because only approximately one third of the patients use their ICD during battery running time. Also according to the largest ICD study on ischemic cardiomyopathy at least six patients must be treated with an ICD to save one life after 8 years. Guidelines for ICD implantation are based on 12 randomized studies with more than 9000 patients. In 2014 in Germany 94 % of ICD implantations were carried out in accordance with the guidelines. The most important studies for primary prophylaxis of SCD (MADIT 2 and SCD-HeFT) finished recruitment of patients in 2001 but propensity score-matched ICD patients from a large national data base showed identical survival curves in 2005 and 2006. New ICD developments in recent years, such as suppression of inappropriate ICD therapy by improved programming, cardiac resynchronization, and telemonitoring showed promise for current ICD patients of improved survival in comparison to the original randomized patients from the studies, which led to the indications in the guidelines.