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Background: Research on chronic subdural hematoma (cSDH) management has primarily focused on potential recurrence after surgical evacuation. Herein, we present a novel postoperative/non-invasive treatment that includes a supervised Valsalva maneuver (SVM), which may serve to reduce SDH recurrence. Accordingly, the aims of the study were to investigate the effects of SVM on SDH recurrence rates and functional outcomes.
Methods: A prospective study was conducted from December 2016 until December 2019 at the Goethe University Hospital Frankfurt. Of the 204 adult patients with surgically treated cSDH who had subdural drains placed, 94 patients were assigned to the SVM group and 82 patients were assigned to the control group. The SVM was performed by having patients blow into a self-made SVM device at least two times/h for 12 h/day. The primary end-point was SDH recurrence rate, while secondary outcomes were morbidity and functional outcomes at 3 months of follow-up.
Results: SDH recurrence was observed in 16 of 94 patients (17%) in the SVM group, which was a significant reduction as compared with the control group, which had 24 of 82 patients (29.3%; p = 0.05) develop recurrent SDHs. Further, the infection rate (e.g., pneumonia) was significantly lower in the SVM group (1.1%) than in the control group (13.4%; p < 0.001; odds ratio [OR] 0.1). At the 3-month follow-up, 85 of 94 patients (90.4%) achieved favorable outcomes in the SVM group compared with 62 of 82 patients (75.6%) in the control group (p = 0.008; OR 3.0). Independent predictors for favorable outcome at follow-up were age (OR 0.9) and infection (OR 0.2).
Conclusion: SVM appears to be safe and effective in the post-operative management of cSDHs, reducing both recurrence rates and infections after surgical evacuation, thereby resulting in favorable outcomes at follow-up.
Meningioma surgery in patients ≥70 years of age: clinical outcome and validation of the SKALE score
(2021)
Along with increasing average life expectancy, the number of elderly meningioma patients has grown proportionally. Our aim was to evaluate whether these specific patients benefit from surgery and to investigate a previously published score for decision-making in meningioma patients (SKALE). Of 421 patients who underwent primary intracranial meningioma resection between 2009 and 2015, 71 patients were ≥70 years of age. We compared clinical data including World Health Organization (WHO) grade, MIB-1 proliferation index, Karnofsky Performance Status Scale (KPS), progression free survival (PFS) and mortality rate between elderly and all other meningioma patients. Preoperative SKALE scores (Sex, KPS, ASA score, location and edema) were determined for elderly patients. SKALE ≥8 was set for dichotomization to determine any association with outcome parameters. In 71 elderly patients (male/female 37/34) all data were available. Postoperative KPS was significantly lower in elderly patients (p < 0.0001). Pulmonary complications including pneumonia (10% vs. 3.2%; p = 0.0202) and pulmonary embolism (12.7% vs. 6%; p = 0.0209) occurred more frequently in our elderly cohort. Analyses of the Kaplan Meier curves revealed differences in three-month (5.6% vs. 0.3%; p = 0.0033), six-month (7% vs. 0.3%; p = 0.0006) and one-year mortality (8.5% vs. 0.3%; p < 0.0001) for elderly patients. Statistical analysis showed significant survival benefit in terms of one-year mortality for elderly patients with SKALE scores ≥8 (5.1 vs. 25%; p = 0.0479). According to our data, elderly meningioma patients face higher postoperative morbidity and mortality than younger patients. However, resection is reasonable for selected patients, particularly when reaching a SKALE score ≥ 8.
Research aimed at helping to solve pressing societal problems must meet specific quality requirements: The knowledge it produces must not only be sound but also useable. This is particularly true of research that aims at bringing specific knowledge to bear on policy issues relating to sustainable development. This guide provides detailed actor-specific requirements profiles for this type of “policy relevant sustainability research.”
This guide is aimed at research funding agencies and contracting entities, researchers themselves and policymakers1 who participate directly in the research process. It can be used both for cases where the research funding agency/contracting entity and the policymaker are different institutions or where they are identical. However, policy consulting by specialized agencies that do not perform original research is not addressed.
The requirements profiles serve two functions. First of all, they should function as a guide for the three stakeholder groups, aiding them in their efforts to increase and ensure the quality of research processes and research outcomes. And, secondly, they should improve the reflexive communication among stakeholders regarding the means and the goals of research...
The results presented here are part of a research and development project (Research Code Number: 3711 11 701) funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) and the German Federal Environment Agency (UBA). The project was carried out by the Institute for Social-Ecological Research (ISOE, project management), the Institute for Ecological Economy Research and the Environmental Policy Research Center for of the Freie Universität Berlin (FFU) (project duration: 09/2011-01/2013).
The aim of the project was to develop concepts that can be used to increase the relevance of sustainability research for the design of environmental policy in Germany. In addition to the requirements profiles for a policy relevant sustainability research presented in this guide, recommendations, based on empirical studies, have been developed regarding how the coordination between different government departments with respect to funding such research can be optimized. The project's final report will be available starting March 2013 from the UBA.
Forschung, die einen unmittelbaren Beitrag zur Lösung drängender gesellschaftlicher Probleme leisten will, muss sich besonderen Qualitätsanforderungen stellen: Sie soll nicht nur gesichertes, sondern auch anwendbares Wissen bereithalten. Dies gilt besonders für Forschung, die darauf zielt, Politik in Fragen nachhaltiger Entwicklung mit spezifischem Wissen zu unterstützen. Für diesen Typ einer „politik-relevanten Nachhaltigkeitsforschung“ präsentiert der vorliegende Wegweiser ein detailliertes Anforderungsprofil.
Der Wegweiser richtet sich an Förderer oder Auftraggeber einer solchen Forschung, an die Forschenden selbst und an Akteure aus der Politik, die sich direkt an Forschungsprozessen beteiligen. Er kann dabei sowohl für den Fall genutzt werden, dass Forschungsförderer oder Auftraggeber und politische Praxispartner verschiedene Institutionen sind, als auch für den Fall, dass sie identisch sind. Politische Beratung durch spezialisierte Agenturen, die keine eigene Forschung leisten, wird dagegen nicht adressiert.
Die im Detail ausgearbeiteten Anforderungen haben zwei Funktionen. Sie sollen zum einen den drei genannten Akteursgruppen als Orientierung dienen, wie sie dazu beitragen können, die Qualität von Forschungsprozessen und Forschungsergebnissen zu erhöhen und zu sichern. Zum anderen sollen sie die reflexive Kommunikation zwischen den Akteuren über Mittel und Zwecke der Forschung verbessern. ...
In Germany, as in almost all industrial countries, active pharmaceutical substances can now be found in virtually all water bodies and occasionally also in drinking water. Even though the concentrations in question tend to be very low, there are initial signs of their impact on aquatic life. There is no evidence as yet of any acute consequences for human health. It is, however, impossible to rule out long-term consequences from these minimal concentrations or unexpected effects from the interaction between various active ingredients (cocktail effect). At special risk here are sensitive segments of the population such as children and the chronically ill. There is thus a need for action on precautionary grounds.
The main actors in the health system are largely unaware of the problem posed by drug residues in water. Although knowledge cannot be equated with awareness – given the existence of the ‘not wanting to know' phenomenon – the first step is to generate a consolidated knowledge base. Only by creating awareness of the problem can further strategies be implemented to ultimately enlighten and bring about behavioural change. At stake here is the overall everyday handling of medications, including prescription, compliance, and drug-free disease prevention down to the doctor-patient relationship. The latter, namely, is often characterised by misunderstandings and a lack of communication about the – supposed – need to prescribe drugs.
The first part of the strategy for the general public involves using various channels and media to address three different target groups. These were identified by ISOE in an empirical survey as reacting differently to the problem under review:
· ‘The Deniers/Relativists'
· ‘The Truth-Seekers'
· ‘The Hypersensitives'
The intention is to address each target group in the right tone and using the most suitable line of reasoning via specific media and with the proper degree of differentiation. The ‘Truth-Seekers' play an opinion-leading role here. They can be provided with highly differentiated information through sophisticated media which they then pass on to their dialogue partners in an appropriate form.
The second part of the strategy for the general public relates to the communication of proper disposal routes for expired drugs. The goal is to confine disposal to pharmacies so that on no account are they flushed down the sink or toilet. Based on an analysis of typical errors in existing communications media on this topic, ISOE prepared recommendations for drafting proper information materials.
In addressing pharmacists, the first priority is to convey hard facts: to this end we propose a PR campaign to place articles in the main specialist media. At the same time, the subject should feature in training and continuing education programmes. Another aim is to strengthen the advisory function of the pharmacies. The environmentally sensitive target group would indeed react positively to having their attention drawn to the issue of drug residues in water. For all other customers, the pharmacists can and should act as consultants: they emphasise how important it is to take medication as instructed (compliance) and use suitable pack sizes, and warn older customers in particular about the potential hazards of improper drug intake.
The first stage of the communications strategy for doctors likewise revolves around knowledge. Here, however, it is important to take into account their self-image as scientists while in fact having little grasp of this specific area. The line to take is that of ‘discursive selfenlightenment'. This means that the issue of drug residues in water cannot be conveyed to doctors by laymen but must be taken up and imparted via the major media of the medical profession and by medical association officials (top-down).
The second stage, namely that of raising doctors’ awareness of the problem, is likely to encounter strong resistance from some of the medical profession. They may fear a threat of interference in treatment plans from an environmental perspective and feel the need to emphasise that doctors are not responsible for environmental issues. As shown in empirical surveys by ISOE, such a defensive reaction is ultimately down to an underlying taboo: people are loath to discuss the over-prescription taking place in countless doctors' surgeries. And it is a fact that this problem cannot be tackled from the environmental perspective, although the goals of water protection are indeed consistent with the economic objectives of restraint in the deployment of drugs. Any communications measure for this target group has to bear in mind that doctors feel restricted by what they see as a ‘perpetual health reform' no matter which government is in power. On no account are they prepared to tolerate any new form of regulation, in this case for environmental reasons.
An entirely different view of the problem is taken by ‘critical doctors' such as specialists in environmental health and those with a naturopathic focus. They are interested in the problem because they see a connection between the quality of our environment and our health. What is more, they have patients keen to be prescribed as few drugs as possible and who are instead interested in ‘talking medicine'. So, any communication strategy intent on tackling the difficult problem of oversubscribing drugs needs to look carefully at the experiences of these medical professionals and also at a ‘bottom-up strategy'.
Implementation of strategic communications should be entrusted to an agency with experience in ‘issue management'. Knowledge of social marketing and the influencing of behaviour are further prerequisites. All important decisions should be taken by a consensus committee (‘MeriWa'1 round table), in which the medical profession, pharmacists and consumers are represented.
In Deutschland und in fast allen Industrieländern finden sich mittlerweile Medikamentenwirkstoffe in nahezu allen Gewässern und vereinzelt auch im Trinkwasser. Auch wenn die Konzentrationen in der Regel sehr gering sind, lassen sich erste Anzeichen für Auswirkungen auf Wasserlebewesen nachweisen. Akute Folgen für die menschliche Gesundheit sind bisher nicht erwiesen. Es kann allerdings nicht ausgeschlossen werden, dass sich Langzeitfolgen dieser Niedrigstkonzentrationen entwickeln und unerwartete Effekte durch die Wechselwirkung zwischen verschiedenen Wirkstoffen (Cocktaileffekt) entstehen. Besonders gefährdet sind dabei sensible Bevölkerungsgruppen wie Kinder und chronisch Kranke. Es besteht daher nicht zuletzt aus Vorsorgegründen Handlungsbedarf. Das Problem der Medikamentenreste im Wasser ist bei den wichtigsten Akteuren des Gesundheitssystems weitgehend unbekannt. Auch wenn Wissen nicht mit Bewusstsein gleichgesetzt werden kann – denn es gibt auch das Phänomen des Nicht-Wissen-Wollens – geht es in einem ersten Schritt darum, fundiertes Wissen zu erzeugen. Nur auf Basis dieser Sensibilisierung können weitere Strategien umgesetzt und letztendlich Aufklärung und Verhaltensänderungen erreicht werden. Dabei geht es um die gesamte Alltagspraxis im Umgang mit Medikamenten. Diese umfasst Fragen der Verschreibung, der Compliance, der nichtmedikamentösen Krankheitsvorsorge bis hin zum Arzt-Patienten-Verhältnis. Das ist nämlich häufig von Missverständnissen und mangelnder Kommunikation über – vermeintliche – Verschreibungsnotwendigkeiten geprägt. Der erste Teil der Strategie für die Bevölkerung soll über unterschiedliche Kanäle und Medien drei unterschiedliche Zielgruppen ansprechen, die in einer empirischen Untersuchung vom ISOE identifiziert wurden und auf das angesprochene Problem ganz unterschiedlich reagieren: · ‚Die Verleugner/Relativierer‘ · ‚Die Aufklärungsinteressierten‘ · ‚Die Hypersensiblen‘ Jede Zielgruppe soll in der passenden sprachlichen und argumentativen Art und Weise durch spezifische Medien und mit dem richtigen Grad der Differenziertheit angesprochen werden. Dabei spielen „die Aufklärungsinteressierten“ eine Opinionleader-Rolle. Sie können über anspruchsvolle Medien mit sehr differenzierten Informationen versorgt werden und geben dieses Wissen dann in angemessener Form an ihre Gesprächspartner weiter. Der zweite Teil der Strategie für die Bevölkerung bezieht sich auf die Kommunikation richtiger Entsorgungswege für Altmedikamente. Ziel ist es, dass Medikamentenreste nur noch in der Apotheke, keinesfalls aber in der Spüle oder in der Toilette entsorgt werden. Auf Grundlage einer Analyse typischer Fehler in bereits bestehenden Kommunikationsmedien zu diesem Thema hat das ISOE Empfehlungen zur richtigen Konzeption von Infomaterialien erarbeitet. Bei der Ansprache der Apotheker geht es in einem ersten Schritt um die Vermittlung von Faktenwissen: Wir schlagen dazu eine PR-Kampagne vor, die Artikel in den wichtigsten Fachmedien platziert. Gleichzeitig soll das Thema auch Teil der Aus- und Fortbildung werden. Zusätzlich soll die Beraterfunktion der Apotheken gestärkt werden. Die spezielle Zielgruppe der umweltsensiblen Kunden würde durchaus positiv darauf reagieren, wenn sie auf die Problematik der Medikamentenreste im Wasser hingewiesen würde. Bei allen anderen Kunden können und sollen die Apotheker ihre Rolle als Berater wahrnehmen: Sie betonen, wie wichtig die korrekte Einnahme (Compliance) und adäquate Packungsgrößen sind und warnen ihre Kunden, insbesondere die älteren, auch vor potenziellen Fehleinnahmen. Bei der Kommunikationsstrategie für Ärzte geht es im ersten Schritt ebenfalls um Wissen. Dabei muss aber deren Selbstverständnis als Wissenschaftler bei gleichzeitig niedrigem Wissensstand in diesem speziellen Feld berücksichtigt werden. Hier muss der Weg einer ‚diskursiven Selbstaufklärung‘ beschritten werden. Das Thema Medikamentenreste im Wasser kann somit nicht von Laien von außen an die Ärzte herangetragen werden, sondern muss in wichtigen Medien der Ärzteschaft und durch Verbandsfunktionäre angenommen und kommuniziert werden (top-down). Wenn es im zweiten Schritt um eine Problemsensibilisierung geht, muss mit starkem Widerstand eines Teils der Ärzteschaft gerechnet werden. Sie könnten fürchten, dass eine Einmischung in Heilungspläne aus Umweltsicht droht und betonen, dass Ärzte nicht für Umweltfragen zuständig seien. Letztlich steht – das haben empirische Untersuchungen des ISOE gezeigt – hinter dieser Problemabwehr ein Tabu: Es soll nicht darüber gesprochen werden, dass in zahlreichen Praxen zu viel verschrieben wird. Diese Problematik kann tatsächlich nicht aus der Umweltperspektive angegangen werden. Doch decken sich hier die Ziele des Gewässerschutzes mit den ökonomischen Zielen eines sparsamen Umgangs mit Arzneimitteln. Bei jeder Kommunikationsmaßnahme für diese Zielgruppe muss berücksichtigt werden, dass sich die Ärzte von dem, was sie als ‚Dauergesundheitsreform‘ aller Regierungen wahrnehmen, gegängelt fühlen. Sie sind keinesfalls bereit, eine neue Form der Regulierung, diesmal aus Umweltgründen, hinzunehmen. Ganz anders wird das Problem von ‚kritischen Ärzten‘ wie Umweltmedizinern und von Ärzten mit Naturheilschwerpunkt gesehen. Sie interessieren sich für die Problematik, weil sie einen Zusammenhang zwischen Umweltqualität und Gesundheit sehen. Außerdem haben sie Patienten, die an möglichst wenig Medikamentenverschreibungen, dafür aber an einer ‚sprechenden Medizin‘ interessiert sind. Wenn eine Kommunikationsstrategie also auch das schwierige Problem der übermäßigen Verschreibungen angehen will, empfiehlt es sich, die Erfahrungen dieser Mediziner einzubeziehen und zusätzlich auf eine ‚Bottom-up-Strategie‘ abzuzielen. Mit der Umsetzung der strategischen Kommunikation sollte eine Agentur beauftragt werden, die Erfahrungen im ‚Issue Management‘ vorweisen kann. Weiterhin sollte die Agentur Kenntnisse im Social Marketing und der Beeinflussung von Verhalten haben. Alle wichtigen Entscheidungen sollten von einem Konsens-Gremium (Runder Tisch ‚MeriWa‘1) verabschiedet werden, in dem die Ärzteschaft, die Apotheker sowie die Verbraucherinnen und Verbraucher angemessen repräsentiert sind.
Glioblastoma (GBM) is a cancer type with high thrombogenic potential and GBM patients are therefore at a particularly high risk for thrombotic events. To date, only limited data on anticoagulation management after pulmonary embolism (PE) in GBM is available and the sporadic use of DOACs remains off-label. A retrospective cohort analysis of patients with GBM and postoperative, thoracic CT scan confirmed PE was performed. Clinical course, follow-up at 6 and 12 months and the overall survival (OS) were evaluated using medical charts and neuroradiological data. Out of 584 GBM patients, 8% suffered from postoperative PE. Out of these, 30% received direct oral anticoagulants (DOACs) and 70% low-molecular-weight heparin (LMWH) for therapeutic anticoagulation. There was no significant difference in major intracranial hemorrhage (ICH), re-thrombosis, or re-embolism between the two cohorts. Although statistically non-significant, a tendency to reduced mRS at 6 and 12 months was observed in the LMWH cohort. Furthermore, patients receiving DOACs had a statistical benefit in OS. In our analysis, DOACs showed a satisfactory safety profile in terms of major ICH, re-thrombosis, and re-embolism compared to LMWH in GBM patients with postoperative PE. Prospective, randomized trials are urgent to evaluate DOACs for therapeutic anticoagulation in GBM patients with PE.
Background: Glioblastoma (GBM) is a cancer type with high thrombogenic potential and GBM patients are therefore at a particularly high risk for thrombotic events. To date only limited data on anticoagulation management after pulmonary embolism (PE) in GBM is available and the sporadic use of DOACs remains off-label.
Methods: A retrospective cohort analysis of patients with GBM and postoperative, thoracic CT-scan confirmed, PE was performed. Clinical course, follow-up at 6 and 12 months and the overall survival (OS) were evaluated using medical charts and neuroradiological data.
Results: Out of 584 GBM patients, 8% suffered from postoperative PE. Out of theses, 30% received direct oral anticoagulants (DOACs) and 70% low-molecular-weight heparin (LMWH) for therapeutic anticoagulation. There was no significant difference in major intracranial hemorrhage (ICH), re-thrombosis or re-embolism between the two cohorts. Although statistically non-significant, a tendency to reduced mRS at 6- and 12 months was observed in the LMWH cohort. Furthermore, patients receiving DOACs had a statistical benefit in OS.
Conclusion: In our analysis DOACs showed a satisfactory safety profile in terms of major ICH, re-thrombosis and re-embolism compared to LMWH in GBM patients with postoperative PE. Prospective, randomized trials are urgent to evaluate DOACs for therapeutic anticoagulation in GBM patients with PE.
Purpose: In patients with pyogenic spondylodiscitis, surgery is considered the treatment of choice to conduct proper debridement, stabilise the spine and avoid extended bed rest, which in turn is a risk factor for complications such as deep vein thrombosis and pulmonary embolism. Methods: We conducted a retrospective clinical study with analysis of a group of 99 patients who had undergone treatment for pyogenic discitis at our institution between June 2012 and August 2017. Included parameters were age, sex, disease pattern, the presence of deep vein thrombosis, resuscitation, in-hospital mortality, present anticoagulation, preexisting comorbidities, tobacco abuse, body mass index, microbiological germ detection and laboratory results. Results: Among the analysed cohort, 12% of the treated patients for pyogenic spondylodiscitis suffered from a radiologically confirmed pulmonary embolism. Coronary heart disease (p < 0.01), female sex (p < 0.01), anticoagulation at admission (p < 0.01) and non-O blood type (p < 0.001) were associated with development of pulmonary embolism. Pulmonary embolism was significantly associated with resuscitation (p < 0.005) and deep vein thrombosis (p < 0.001). Neurosurgery was not associated with increased risk for pulmonary embolism compared to conservative-treated patients (p > 0.05). Conclusion: Surgery for pyogenic spondylodiscitis was not associated with an elevated risk of pulmonary embolism in our analysis. However, we describe several risk factors for pulmonary embolism in this vulnerable cohort. Prospective studies are necessary to improve prevention and postoperative management in patients with pyogenic spondylodiscitis.
Background: The incidence of pyogenic spinal infection has increased in recent years. In addition to treatment of the spinal infection, early diagnosis and therapy of coexisting infections, especially of secondary brain infection, are important. The aim of this study is to elucidate the added value of routine cerebral imaging in the management of these patients.
Methods: This was a retrospective single-center study. Cerebral imaging consisting of cerebral magnetic resonance imaging (cMRI) was performed to detect brain infection in patients with a primary pyogenic spinal infection. Results: We analyzed a cohort of 61 patients undergoing cerebral imaging after diagnosis of primary pyogenic spinal infection. The mean age in this cohort was 68.7 years and the gender distribution consisted of 44 males and 17 females. Spinal epidural abscess was proven in 32 (52.4%) patients. Overall positive blood culture was obtained in 29 (47.5%) patients, infective endocarditis was detected in 23 (37.7%) patients and septic condition at admission was present in 12 (19.7%) Patients. Coexisting brain infection was detected in 2 (3.3%) patients. Both patients revealed clinical signs of severe sepsis, reduced level of consciousness (GCS score 3), were intubated, and died due to multi-organ failure. Conclusions: Brain infection in patients with spinal infection is very rare. Of 61 patients with pyogenic spinal infection, two patients had signs of cerebral infection shown by imaging, both of whom were in a coma (GCS 3), and sepsis.
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±, Ξ(1530)0) produced in p–Pb collisions at sNN−−−√=5.02 TeV were measured in the rapidity range −0.5<yCMS<0 for event classes corresponding to different charged-particle multiplicity densities, ⟨dNch/dηlab⟩. The mean transverse momentum values are presented as a function of ⟨dNch/dηlab⟩, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨dNch/dηlab⟩. The equivalent ratios to pions exhibit an increase with ⟨dNch/dηlab⟩, depending on their strangeness content.
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±, Ξ(1530)0) produced in p-Pb collisions at sNN−−−√=5.02 TeV were measured in the rapidity range −0.5<yCMS<0 for event classes corresponding to different charged-particle multiplicity densities, ⟨dNch/dηlab⟩. The mean transverse momentum values are presented as a function of ⟨dNch/dηlab⟩, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨dNch/dηlab⟩. The equivalent ratios to pions exhibit an increase with ⟨dNch/dηlab⟩, depending on their strangeness content.
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±, Ξ(1530)0) produced in p-Pb collisions at sNN−−−√=5.02 TeV were measured in the rapidity range −0.5<yCMS<0 for event classes corresponding to different charged-particle multiplicity densities, ⟨dNch/dηlab⟩. The mean transverse momentum values are presented as a function of ⟨dNch/dηlab⟩, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨dNch/dηlab⟩. The equivalent ratios to pions exhibit an increase with ⟨dNch/dηlab⟩, depending on their strangeness content.
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±,Ξ(1530)0) produced in p–Pb collisions at √sNN = 5.02 TeV were measured in the rapidity range −0.5<yCMS<0 for event classes corresponding to different charged-particle multiplicity densities, ⟨dNch/dηlab⟩. The mean transverse momentum values are presented as a function of ⟨dNch/dηlab⟩, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨dNch/dηlab⟩. The equivalent ratios to pions exhibit an increase with ⟨dNch/dηlab⟩, depending on their strangeness content.
We report measurements of the inclusive J/ψ yield and average transverse momentum as a function of charged-particle pseudorapidity density dNch/dη in p–Pb collisions at √sNN = 5.02 TeV with ALICE at the LHC. The observables are normalised to their corresponding averages in non-single diffractive events. An increase of the normalised J/ψ yield with normalised dNch/dη, measured at mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward rapidity, a saturation of the relative yield is observed for high charged-particle multiplicities. The normalised average transverse momentum at forward and backward rapidities increases with multiplicity at low multiplicities and saturates beyond moderate multiplicities. In addition, the forward-to-backward nuclear modification factor ratio is also reported, showing an increasing suppression of J/ψ production at forward rapidity with respect to backward rapidity for increasing charged-particle multiplicity.
The yields of strange (K0S, Λ, Λ¯) and multi-strange (Ξ−, Ξ¯+, Ω−, Ω¯+) hadrons are measured at midrapidity in proton-proton (pp) collisions at s√ = 7 TeV as a function of the charged-particle multiplicity density (dNch/dη).The production rate of strange particles increases faster than that of non-strange hadrons, leading to an enhancement of strange particles relative to pions, similar to that found in nucleus-nucleus collisions as well as in proton-nucleus collisions at the LHC. This is the first observation of an enhanced production of strange particles in high-multiplicity pp collisions. The magnitude of this strangeness enhancement increases with the event activity, quantified by dNch/dη, and with hadron strangeness. It reaches almost a factor of two for the Ω at the highest multiplicity presented. No enhancement is observed for particles with no strange quark content, demonstrating that the observed effect is strangeness rather than mass related. The results are not reproduced by any of the Monte Carlo models commonly used at the LHC, suggesting that further developments are needed for a complete microscopic understanding of strangeness production and indicating the presence of a phenomenon novel in high-multiplicity pp collisions.
At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark–gluon plasma (QGP)1. Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed2,3,4,5,6. Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions7, is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton–proton (pp) collisions8,9, but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton–proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p–Pb collision results10,11, indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb–Pb collisions, where a QGP is formed.