Publications by authors named "Hansel A"

Aircraft observations have revealed ubiquitous new particle formation in the tropical upper troposphere over the Amazon and the Atlantic and Pacific oceans. Although the vapours involved remain unknown, recent satellite observations have revealed surprisingly high night-time isoprene mixing ratios of up to 1 part per billion by volume (ppbv) in the tropical upper troposphere. Here, in experiments performed with the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber, we report new particle formation initiated by the reaction of hydroxyl radicals with isoprene at upper-tropospheric temperatures of -30 °C and -50 °C.

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Objectives: This study was designed to evaluate the performance of a host gene methylation marker panel (ASTN1, DLX1, ITGA4, RXFP3, SOX17, and ZNF671) in the triage of human papillomavirus (HPV)-positive women, its possible impact in a cervical cancer screening program, and the possible influence of the variation of the rate of HPV16/18 in its performance.

Materials And Methods: Cohort study in which consecutive women referred for colposcopy in an organized cervical cancer screening program had repeated HPV testing, colposcopy, and biopsies. The women that remained HPV positive at the time of colposcopy were tested with the panel of DNA methylation markers.

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Drug reaction with eosinophilia and systemic symptoms (DRESS) is an illness which is difficult to diagnose because of its various symptoms. In our case, a patient with small spotted exanthema with nearly erythroderma and eosinophilia presented to the emergency room. Systemic steroid therapy was started on suspicion of a drug reaction.

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  • * The study found that particle formation rates due to ion-induced processes are stable across temperature changes, while neutral particle formation rates increase significantly when temperatures drop from +10 °C to -10 °C.
  • * Despite higher ionization rates, the formation of charged clusters is unlikely to be enhanced in upper tropospheric conditions; instead, neutral nucleation is expected to dominate, with humidity having little effect unless extremely low.
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Highly oxygenated organic molecules (HOMs) are a major source of new particles that affect the Earth's climate. HOM production from the oxidation of volatile organic compounds (VOCs) occurs during both the day and night and can lead to new particle formation (NPF). However, NPF involving organic vapors has been reported much more often during the daytime than during nighttime.

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  • New particle formation (NPF) in the tropical free troposphere is crucial for creating cloud condensation nuclei, influencing cloud properties and climate.
  • Researchers conducted molecular-level measurements of oxidized organic molecules (OOMs) at a high-altitude site in Bolivia, uncovering their presence in both gas and particle phases, with a focus on short-chain carbon compounds.
  • The study links these OOMs to isoprene emissions from distant rainforests and suggests they play a role in the growth of newly formed nanoparticles, advancing our understanding of aerosol formation in this region.
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The main nucleating vapor in the atmosphere is thought to be sulfuric acid (HSO), stabilized by ammonia (NH). However, in marine and polar regions, NH is generally low, and HSO is frequently found together with iodine oxoacids [HIO, i.e.

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During August-December 2022, toxigenic Corynebacterium diphtheriae was isolated from 25 refugees with skin infections and 2 refugees with asymptomatic throat colonization at a refugee reception center in Germany. None had systemic toxin-mediated illness. Of erosive/ulcerative skin infections, 96% were polymicrobial.

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Biogenic vapors form new particles in the atmosphere, affecting global climate. The contributions of monoterpenes and isoprene to new particle formation (NPF) have been extensively studied. However, sesquiterpenes have received little attention despite a potentially important role due to their high molecular weight.

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  • The interaction between nitrogen monoxide (NO) and organic peroxy radicals (RO) is crucial for creating highly oxygenated organic molecules (HOM), which are essential for forming secondary organic aerosols.
  • New experiments show that low levels of NO (0 - 82 pptv) can actually boost HOM production by affecting RO loss and promoting alkoxy radical formation, which continues to react and form more HOM.
  • These findings reveal that HOM yields in boreal forest emissions can range from 2.5%-6.5%, and high NO levels do not completely stop HOM formation, challenging previous beliefs about NO's role in lowering HOM yields, especially in environments with low NO.
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  • The study investigates how high relative humidity (RH) influences the partitioning of biogenic oxidized organic molecules into secondary organic aerosols (SOA) using real-time measurements in a controlled lab setting.
  • Results show significant increases in SOA mass (45%-85%) as RH rises from low to high levels, with semi-volatile compounds playing a key role in this process.
  • The research explains that higher RH alters the chemical composition of aerosols, shifting toward more volatile species, and emphasizes the critical role of water content in promoting organic aerosol growth.
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Iodine is a reactive trace element in atmospheric chemistry that destroys ozone and nucleates particles. Iodine emissions have tripled since 1950 and are projected to keep increasing with rising O surface concentrations. Although iodic acid (HIO) is widespread and forms particles more efficiently than sulfuric acid, its gas-phase formation mechanism remains unresolved.

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  • Dimethyl sulfide (DMS) contributes to climate change by affecting cloud formation through its oxidation products, primarily methanesulfonic acid (MSA) and sulfuric acid (HSO), but predicting their levels accurately is difficult.
  • Experiments conducted at CERN's CLOUD chamber showed that lowering the temperature significantly boosts the production of MSA from DMS oxidation, while HSO production remains relatively stable, resulting in a lower HSO/MSA ratio at cold temperatures.
  • The research introduces a new DMS oxidation mechanism that increases MSA production estimates, significantly higher than previous models, revealing MSA's crucial role in the sulfur cycle and its impact on cloud condensation nuclei.
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  • New particle formation events occur frequently in polluted environments, despite high loss rates of tiny clusters, suggesting scavenging by larger particles or unknown growth mechanisms might be less effective than anticipated.
  • Experiments in the CLOUD chamber at CERN showed that the creation of new particles from human-made vapors significantly drops when there are many pre-existing particles, proving they effectively scavenge smaller molecular clusters.
  • In conditions with high levels of nitric acid and ammonia, newly formed particles can grow rapidly and maintain their numbers, even in heavily polluted air, which helps explain why these particles survive in haze-like situations.
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New particle formation in the upper free troposphere is a major global source of cloud condensation nuclei (CCN). However, the precursor vapours that drive the process are not well understood. With experiments performed under upper tropospheric conditions in the CERN CLOUD chamber, we show that nitric acid, sulfuric acid and ammonia form particles synergistically, at rates that are orders of magnitude faster than those from any two of the three components.

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We report a monolithically integrated coupled extended-cavity distributed Bragg reflector laser with, to our knowledge, the lowest reported intrinsic linewidth of ∼10 kHz, which is extracted from a corresponding frequency-noise level of ∼3200 Hz/Hz, realized on an InP generic foundry platform. Using the delayed self-heterodyne method, the experimentally measured linewidth was 45 kHz. The laser has an on-chip optical output power of 18 mW around 1550 nm at an injection current of 95 mA.

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  • The study investigates the prevalence of restless legs syndrome (RLS) among psychiatric inpatients in Germany and Switzerland, finding that 16.4% of the 317 patients had RLS, with most cases being diagnosed for the first time.
  • Key factors associated with RLS included higher prevalence in women and those with family history of RLS, as well as significant differences in sleep quality and daytime sleepiness scores compared to non-RLS patients.
  • Logistic regression identified gender, family history, and daytime sleepiness as significant predictors of RLS occurrence, while there were no notable ties between RLS symptoms and psychotropic drug treatments, except for atypical antipsychotics.
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Aerosol particles negatively affect human health while also having climatic relevance due to, for example, their ability to act as cloud condensation nuclei. Ultrafine particles (diameter < 100 nm) typically comprise the largest fraction of the total number concentration, however, their chemical characterization is difficult because of their low mass. Using an extractive electrospray time-of-flight mass spectrometer (EESI-TOF), we characterize the molecular composition of freshly nucleated particles from naphthalene and β-caryophyllene oxidation products at the CLOUD chamber at CERN.

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Background: Organ transplant recipients show a high incidence for the formation of cutaneous squamous cell carcinoma (cSCC), while sirolimus appears to reduce the risk. GRO-α is a chemokine, which is overexpressed in many tumor entities and associated with malignant transformation. However, little is known about the expression and function of GRO-α in human cSCC.

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Isoprene is emitted from the biosphere into the atmosphere, and may strengthen the defense mechanisms of plants against oxidative and thermal stress. Once in the atmosphere, isoprene is rapidly oxidized, either to isoprene-hydroxy-hydroperoxides (ISOPOOH) at low levels of nitrogen oxides, or to methyl vinyl ketone (MVK) and methacrolein at high levels. Here we combine uptake rates and deposition velocities that we obtained in laboratory experiments with observations in natural forests to show that 1,2-ISOPOOH deposits rapidly into poplar leaves.

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Article Synopsis
  • - Iodic acid (HIO) can rapidly form aerosol particles in coastal areas, with nucleation rates surpassing those of sulfuric acid-ammonia under similar conditions.
  • - Ion-induced nucleation involves the initial formation of IO followed by the addition of HIO, occurring efficiently at temperatures below +10°C, while neutral nucleation relies on a different process involving iodous acid.
  • - Freshly formed HIO particles significantly contribute to fast particle growth and can effectively compete with sulfuric acid particle formation in unpolluted atmospheric regions.
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Aim: High-risk human papillomavirus (hrHPV)-based screening is becoming increasingly important, either by supplementing or replacing the traditional cytology-based cervical Pap smear. However, hrHPV screening lacks specificity, because it cannot differentiate between transient virus infection and clinically relevant hrHPV-induced disease. Therefore, reliable triage methods are needed for the identification of HPV-positive women with cervical intraepithelial neoplasia (CIN) in need of treatment.

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Background: The community-based mental health care programme GBV is based on the British Community Mental Health Teams and the Dutch Flexible Assertive Community Treatment model. In addition, the programme offers crisis-intervention services. A special feature of this integrated care programme is the initial standardised assessment process regarding empowerment, unmet care needs, and psychosocial functioning, used to verify the need for such a comprehensive form of care.

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