All-optical subcycle microscopy on atomic length scales

Bringing optical microscopy to the shortest possible length and time scales has been a long-sought goal, connecting nanoscopic elementary dynamics with the macroscopic functionalities of condensed matter. Super-resolution microscopy has circumvented the far-field diffraction limit by harnessing optical nonlinearities1. By exploiting linear interaction with tip-confined evanescent light fields2, near-field microscopy3,4 has reached even higher resolution, prompting a vibrant research field by exploring the nanocosm in motion5-19. Yet the finite radius of the nanometre-sized tip apex has prevented access to atomic resolution20. Here we leverage extreme atomic nonlinearities within tip-confined evanescent fields to push all-optical microscopy to picometric spatial and femtosecond temporal resolution. On these scales, we discover an unprecedented and efficient non-classical near-field response, in phase with the vector potential of light and strictly confined to atomic dimensions. This ultrafast signal is characterized by an optical phase delay of approximately π/2 and facilitates direct monitoring of tunnelling dynamics. We showcase the power of our optical concept by imaging nanometre-sized defects hidden to atomic force microscopy and by subcycle sampling of current transients on a semiconducting van der Waals material. Our results facilitate access to quantum light-matter interaction and electronic dynamics at ultimately short spatio-temporal scales in both conductive and insulating quantum materials.

Perspective on Management of Low-Dose Computed Tomography Findings on Low-Dose Computed Tomography Examinations for Lung Cancer Screening. From the International Association for the Study of Lung Cancer Early Detection and Screening Committee

Lung cancer screening using low-dose computed tomography (LDCT) carefully implemented has been found to reduce deaths from lung cancer. Optimal management starts with selection of eligibility criteria, counseling of screenees, smoking cessation, selection of the regimen of screening which specifies the imaging protocol, and workup of LDCT findings. Coordination of clinical, radiologic, and interventional teams and ultimately treatment of diagnosed lung cancers under screening determine the benefit of LDCT screening. Ethical considerations of who should be eligible for LDCT screening programs are important to provide the benefit to as many people at risk of lung cancer as possible. Unanticipated diseases identified on LDCT may offer important benefits through early detection of leading global causes of death, such as cardiovascular diseases and chronic obstructive pulmonary disease, as the latter may result from conditions such as emphysema and bronchiectasis, which can be identified early on LDCT. This report identifies the key components of the regimen of LDCT screening for lung cancer which include the need for a management system to provide data for continuous updating of the regimen and provides quality assurance assessment of actual screenings. Multidisciplinary clinical management is needed to maximize the benefit of early detection, diagnosis, and treatment of lung cancer. Different regimens have been evolving throughout the world as the resources and needs may be different, for countries with limited resources. Sharing of results, further knowledge, and incorporation of technologic advances will continue to accelerate worldwide improvements in the diagnostic and treatment approaches.

Build-up and dephasing of Floquet-Bloch bands on subcycle timescales

Strong light fields have created opportunities to tailor novel functionalities of solids1-5. Floquet-Bloch states can form under periodic driving of electrons and enable exotic quantum phases6-15. On subcycle timescales, lightwaves can simultaneously drive intraband currents16-29 and interband transitions18,19,30,31, which enable high-harmonic generation16,18,19,21,22,25,28-30 and pave the way towards ultrafast electronics. Yet, the interplay of intraband and interband excitations and their relation to Floquet physics have been key open questions as dynamical aspects of Floquet states have remained elusive. Here we provide this link by visualizing the ultrafast build-up of Floquet-Bloch bands with time-resolved and angle-resolved photoemission spectroscopy. We drive surface states on a topological insulator32,33 with mid-infrared fields-strong enough for high-harmonic generation-and directly monitor the transient band structure with subcycle time resolution. Starting with strong intraband currents, we observe how Floquet sidebands emerge within a single optical cycle; intraband acceleration simultaneously proceeds in multiple sidebands until high-energy electrons scatter into bulk states and dissipation destroys the Floquet bands. Quantum non-equilibrium calculations explain the simultaneous occurrence of Floquet states with intraband and interband dynamics. Our joint experiment and theory study provides a direct time-domain view of Floquet physics and explores the fundamental frontiers of ultrafast band-structure engineering.

Intersubband Polariton-Polariton Scattering in a Dispersive Microcavity

The ultrafast scattering dynamics of intersubband polaritons in dispersive cavities embedding GaAs/AlGaAs quantum wells are studied directly within their band structure using a noncollinear pump-probe geometry with phase-stable midinfrared pulses. Selective excitation of the lower polariton at a frequency of ∼25  THz and at a finite in-plane momentum k_{‖} leads to the emergence of a narrowband maximum in the probe reflectivity at k_{‖}=0. A quantum mechanical model identifies the underlying microscopic process as stimulated coherent polariton-polariton scattering. These results mark an important milestone toward quantum control and bosonic lasing in custom-tailored polaritonic systems in the mid and far infrared.

Field-resolved high-order sub-cycle nonlinearities in a terahertz semiconductor laser

The exploitation of ultrafast electron dynamics in quantum cascade lasers (QCLs) holds enormous potential for intense, compact mode-locked terahertz (THz) sources, squeezed THz light, frequency mixers, and comb-based metrology systems. Yet the important sub-cycle dynamics have been notoriously difficult to access in operational THz QCLs. Here, we employ high-field THz pulses to perform the first ultrafast two-dimensional spectroscopy of a free-running THz QCL. Strong incoherent and coherent nonlinearities up to eight-wave mixing are detected below and above the laser threshold. These data not only reveal extremely short gain recovery times of 2 ps at the laser threshold, they also reflect the nonlinear polarization dynamics of the QCL laser transition for the first time, where we quantify the corresponding dephasing times between 0.9 and 1.5 ps with increasing bias currents. A density-matrix approach reproducing the emergence of all nonlinearities and their ultrafast evolution, simultaneously, allows us to map the coherently induced trajectory of the Bloch vector. The observed high-order multi-wave mixing nonlinearities benefit from resonant enhancement in the absence of absorption losses and bear potential for a number of future applications, ranging from efficient intracavity frequency conversion, mode proliferation to passive mode locking.

From Alpha Diversity to Zzz: Interactions among sleep, the brain, and gut microbiota in the first year of life

Sleep disorders have been linked to alterations of gut microbiota composition in adult humans and animal models, but it is unclear how this link develops. With longitudinal assessments in 162 healthy infants, we present a so far unrecognized sleep-brain-gut interrelationship. First, we report a link between sleep habits and gut microbiota: daytime sleep is associated with bacterial diversity, and nighttime sleep fragmentation and variability link with bacterial maturity and enterotype. Second, we demonstrate a sleep-brain-gut link: bacterial diversity and enterotype are associated with sleep neurophysiology. Third, we show that the sleep-brain-gut link is relevant in development: sleep habits and bacterial markers predict behavioral-developmental outcomes. Our results demonstrate the dynamic interplay between sleep, gut microbiota, and the maturation of brain and behavior during infancy, which aligns with the lately emerging concept of a sleep-brain-gut axis. Importantly, sleep and gut microbiota represent promising health targets since both can be modified non-invasively. As many adult diseases root in early childhood, leveraging protective factors of adequate sleep and age-appropriate gut microbiota in infancy could constitute a health promoting factor across the entire human lifespan.

Apixaban for treatment of embolic stroke of undetermined source (ATTICUS) randomized trial – update of patient characteristics and study timeline after interim analysis

Background

Secondary prevention after embolic stroke of undetermined source (ESUS) has not yet been established. ESUS is associated with high risk of recurrent ischemic stroke and clinically silent ischemic lesions. Secondary prevention with aspirin is the current standard therapy in ESUS patients, despite high prevalence of occult atrial fibrillation (AF).

Purpose

To determine whether the direct oral factor Xa inhibitor apixaban, started within 28 days after index stroke, is superior to aspirin in preventing new ischemic lesions in subjects with remote cardiac monitoring. Primary endpoint was detection of new ischemic lesions in flair and diffusion-weighted (DWI) MR imaging at 12 months follow-up.

Methods

The study enrolled ESUS patients with risk profile for cardiac thromboembolism (i.e., left atrium (LA) size >45 mm, spontaneous echo contrast in LA appendage, LA appendage flow velocity ≤0.2 cm/s, atrial high rate episodes, CHA2DS2-Vasc score ≥4, patent foramen ovale). Patients were randomized 1:1 into the aspirin and apixaban arms. Study drug was initiated within 3–28 days after minor/moderate stroke and 14–28 days after major stroke. MRI (Flair/DWI) was conducted within 7 days of AF detection by remote cardiac monitors and at 12 months. ClinicalTrials.gov Identifier: NCT02427126. Funding: The trial is supported by BMS-Pfizer Alliance.

Results

Enrollment was stopped after interims analysis (including 200 patients) due to futility. Overall, 373 patients were screened with 353 being enrolled (178 and 175 in apixaban and ASA arms, respectively). So far, 130 (73.0%) and 120 (68.6%) subjects from apixaban and ASA arms, respectively, completed the study. 2% death, 1.7% withdrawal, and 1.7% were lost to follow-up. 3.9% did not completed the study for other reasons. Mean age of the ATTICUS population was 68.5 years with 51% males. 80% of the subjects suffered from hypertension. Mean systolic blood pressure at enrollment was 132 mmHg, BMI was 27.7, and CHA2DS-VASc-Score was 4.9. So far, adverse events (AE) occurred in 63% of the subjects, 30% was documented as severe. 6.8% cases of recurrent ischemic stroke and no case of hemorrhagic stroke were reported. Only 1 case of severe bleeding was reported in the aspirin arm. Newly detected AF was reported in 80 patients (23%), 42 occurring in the aspirin arm. As required by protocol, latter were immediately switched from aspirin to apixaban. Due to ongoing data clearing, numbers and % will change until presentation.

Conclusions

In contrast to the recently published NAVIGATE and RESPECT ESUS trials, patients enrolled in ATTICUS need to exhibit additional AF predicting factors. Furthermore, mandatory cardiac remote monitoring will help to elucidate the impact of AF and the effects of early oral anticoagulation with apixaban compared to antiplatelet therapy with aspirin on the incidence of new ischemic lesions after ESUS. Preliminary data will be presented and discussed in the context of current literature.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The trial is supported by BMS-Pfizer Alliance.

Tunable non-integer high-harmonic generation in a topological insulator

When intense lightwaves accelerate electrons through a solid, the emerging high-order harmonic (HH) radiation offers key insights into the material^1-11. Sub-optical-cycle dynamics-such as dynamical Bloch oscillations^2-5, quasiparticle collisions^6,12, valley pseudospin switching¹³ and heating of Dirac gases¹⁰-leave fingerprints in the HH spectra of conventional solids. Topologically non-trivial matter^14,15 with invariants that are robust against imperfections has been predicted to support unconventional HH generation^16-20. Here we experimentally demonstrate HH generation in a three-dimensional topological insulator-bismuth telluride. The frequency of the terahertz driving field sharply discriminates between HH generation from the bulk and from the topological surface, where the unique combination of long scattering times owing to spin-momentum locking¹⁷ and the quasi-relativistic dispersion enables unusually efficient HH generation. Intriguingly, all observed orders can be continuously shifted to arbitrary non-integer multiples of the driving frequency by varying the carrier-envelope phase of the driving field-in line with quantum theory. The anomalous Berry curvature warranted by the non-trivial topology enforces meandering ballistic trajectories of the Dirac fermions, causing a hallmark polarization pattern of the HH emission. Our study provides a platform to explore topology and relativistic quantum physics in strong-field control, and could lead to non-dissipative topological electronics at infrared frequencies.

Addressing COVID-19 challenges in a randomised controlled trial on exercise interventions in a high-risk population

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic is a threat to ongoing clinical trials necessitating regular face-to-face, in-person meetings, particularly in participants with a high risk of complications. Guidance on how to handle and safely continue such trials is lacking. Chronically ill elderly individuals require-in addition to protection from infection-regular physical exercise and social contact to remain healthy. Solutions on how to handle these conflicting necessities are needed. The ENTAIER-randomised controlled trial was investigating the influence of mindful movements on fall risk, fear of falling, mobility, balance, life quality, and other outcomes. The study population was planned to comprise of 550 chronically ill elderly individuals with a high risk of falling. The movements were regularly performed in coached groups over 6 months. After the trial began, COVID-19 lockdowns stopped all in-person meetings, and it was expected that the limitations of this pandemic would continue for a long term. Therefore, the exercise programme, which involved complex movements and was typically conducted face-to-face in groups, had to be substituted by a telemedicine programme within a short timeframe. The objectives, therefore, were to identify challenges and tasks that could to be resolved and steps that could to be taken to achieve high-quality, efficacy, safety, and enable human encounter and motivation.

METHODS

We proceeded with four steps: 1) A literature review on the quality and feasibility issues of telemedicine in general, and specifically, in exercise training in elderly individuals. 2) Participation in two international telemedicine task forces on integrative medicine, particularly, mind-body medicine. 3) Interviews with study therapists, (for practical purposes, eurythmy therapists and Tai Chi teachers are summarized here as therapists) personnel, and international experts on providing mindful movement exercises and other physiotherapies via live telecommunication technology, and with scientists and patient representatives. 4) Final evaluation by the core trial team and subsequent planning and implementation of changes in the trial organisation.

RESULTS

Various tasks and challenges were identified: for the technical equipment for therapists and patients; for the ability of therapists and trial participants to adequately manage the technology and telemedicine intervention; the reservations and concerns about the technology among therapists and participants; safety and data protection in using the technology; and study design. The two major options found on how to continue the trial in the COVID-19 situation were a complete switch to telemedicine and a partial switch in the form of risk management implemented into the former design.

CONCLUSIONS

The management of an ongoing clinical trial in a national or international crisis with a minimum of available time and extra financial resources, alongside with two checklists on steps and procedures for trial continuation and telemedicine implementation, may be informative for other researchers or healthcare providers faced with similar challenges and making similar decisions in the current situation or similar future scenarios. TRAIL REGISTRATION: www.drks.de . DRKS00016609. Registered July 30, 2019.

Tailored Subcycle Nonlinearities of Ultrastrong Light-Matter Coupling

We explore the nonlinear response of tailor-cut light-matter hybrid states in a novel regime, where both the Rabi frequency induced by a coherent driving field and the vacuum Rabi frequency set by a cavity field are comparable to the carrier frequency of light. In this previously unexplored strong-field limit of ultrastrong coupling, subcycle pump-probe and multiwave mixing nonlinearities between different polariton states violate the normal-mode approximation while ultrastrong coupling remains intact, as confirmed by our mean-field model. We expect such custom-cut nonlinearities of hybridized elementary excitations to facilitate nonclassical light sources, quantum phase transitions, or cavity chemistry with virtual photons.

Super-resolution lightwave tomography of electronic bands in quantum materials

Searching for quantum functionalities requires access to the electronic structure, constituting the foundation of exquisite spin-valley-electronic, topological, and many-body effects. All-optical band-structure reconstruction could directly connect electronic structure with the coveted quantum phenomena if strong lightwaves transported localized electrons within preselected bands. Here, we demonstrate that harmonic sideband (HSB) generation in monolayer tungsten diselenide creates distinct electronic interference combs in momentum space. Locating these momentum combs in spectroscopy enables super-resolution tomography of key band-structure details in situ. We experimentally tuned the optical-driver frequency by a full octave and show that the predicted super-resolution manifests in a critical intensity and frequency dependence of HSBs. Our concept offers a practical, all-optical, fully three-dimensional tomography of electronic structure even in microscopically small quantum materials, band by band.

Primary intestinal lymphangiectasia in an adult patient: A case report and review of literature

BACKGROUND

Primary intestinal lymphangiectasia (PIL), first described in 1961, is a rare disorder of unknown etiology resulting in protein-losing enteropathy. The disease is characterized by dilatation and leakage of intestinal lymph vessels leading to hypoalbuminemia, hypogammaglobulinemia, and lymphopenia. Since the severity and location of lymph vessels being affected can vary considerably, the range of associated symptoms is wide from mild lower-limb edema to generalized edema, abdominal and/or pleural effusion, and recurrent diarrhea, among others. Although usually developing in early childhood, we present the case of a 34-year-old woman with PIL. Moreover, we performed a literature review systematically assessing clinical presentation, and provide a practical approach to facilitate diagnosis and therapy of PIL in adults.

CASE SUMMARY

Our patient presented with unspecific symptoms of abdominal discomfort, fatigue, nausea, and recurrent edema of the lower limbs. Interestingly, a striking collinearity of clinical symptoms with female hormone status was evident. Additionally, polyglobulia, hypoalbuminemia, hypogammaglobulinemia, and transient lymphocytopenia were evident. Due to suspicion of a bone marrow disease, an extensive diagnostic investigation was carried out excluding secondary causes of polyglobulinemia and hypoalbuminemia. The diagnosis of primary intestinal lymphangiectasia was established after 22 wk by histological analysis of biopsy samples obtained via enteroscopy. Consecutively, the patient was put on a high-protein and low-fat diet with medium-chain triglycerides supplementation leading to significant improvement of clinical symptoms until 2 years of follow-up.

CONCLUSION

PIL can be the reason for cryptogenic hypoalbuminemia, hypogammaglobulinemia, and lymphopenia in adulthood. Due to difficulty in correct diagnosis, treatment initiation is often delayed despite being effective and well-tolerated. This leads to a significant disease burden in affected patients. PIL is increasingly been recognized in adults since the majority of case reports were published within the last 10 years, pointing towards an underestimation of the true prevalence. The association with female hormone status warrants further investigation.

Non-adiabatic stripping of a cavity field from deep-strongly coupled electrons

Atomically strong light pulses can drive sub-optical-cycle dynamics. When the Rabi frequency - the rate of energy exchange between light and matter - exceeds the optical carrier frequency, fascinating non-perturbative strong-field phenomena emerge, such as high-harmonic generation and lightwave transport. Here, we explore a related novel subcycle regime of ultimately strong light-matter interaction without a coherent driving field. We use the vacuum fluctuations of nanoantennas to drive cyclotron resonances of two-dimensional electron gases to vacuum Rabi frequencies exceeding the carrier frequency. Femtosecond photoactivation of a switch element inside the cavity disrupts this 'deep-strong coupling' more than an order of magnitude faster than the oscillation cycle of light. The abrupt modification of the vacuum ground state causes spectrally broadband polarisation oscillations confirmed by our quantum model. In the future, this subcycle shaping of hybrid quantum states may trigger cavity-induced quantum chemistry, vacuum-modified transport, or cavity-controlled superconductivity, opening new scenarios for non-adiabatic quantum optics.

Ultrafast electron diffraction from nanophotonic waveforms via dynamical Aharonov-Bohm phases

Electron interferometry via phase-contrast microscopy, holography, or picodiffraction can provide a direct visualization of the static electric and magnetic fields inside or around a material at subatomic precision, but understanding the electromagnetic origin of light-matter interaction requires time resolution as well. Here, we demonstrate that pump-probe electron diffraction with all-optically compressed electron pulses can capture dynamic electromagnetic potentials in a nanophotonic material with sub-light-cycle time resolution via centrosymmetry-violating Bragg spot dynamics. The origin of this effect is a sizable quantum mechanical phase shift that the electron de Broglie wave obtains from the oscillating electromagnetic potentials within less than 1 fs. Coherent electron imaging and scattering can therefore reveal the electromagnetic foundations of light-matter interaction on the level of the cycles of light.

Targeted Natural Killer Cell-Based Adoptive Immunotherapy for the Treatment of Patients with NSCLC after Radiochemotherapy: A Randomized Phase II Clinical Trial

PURPOSE

Non-small cell lung cancer (NSCLC) is a fatal disease with poor prognosis. A membrane-bound form of Hsp70 (mHsp70) which is selectively expressed on high-risk tumors serves as a target for mHsp70-targeting natural killer (NK) cells. Patients with advanced mHsp70-positive NSCLC may therefore benefit from a therapeutic intervention involving mHsp70-targeting NK cells. The randomized phase II clinical trial (EudraCT2008-002130-30) explores tolerability and efficacy of ex vivo-activated NK cells in patients with NSCLC after radiochemotherapy (RCT).

PATIENTS AND METHODS

Patients with unresectable, mHsp70-positive NSCLC (stage IIIa/b) received 4 cycles of autologous NK cells activated ex vivo with TKD/IL2 [interventional arm (INT)] after RCT (60-70 Gy, platinum-based chemotherapy) or RCT alone [control arm (CTRL)]. The primary objective was progression-free survival (PFS), and secondary objectives were the assessment of quality of life (QoL, QLQ-LC13), toxicity, and immunobiological responses.

RESULTS

The NK-cell therapy after RCT was well tolerated, and no differences in QoL parameters between the two study arms were detected. Estimated 1-year probabilities for PFS were 67% [95% confidence interval (CI), 19%-90%] for the INT arm and 33% (95% CI, 5%-68%) for the CTRL arm (P = 0.36, 1-sided log-rank test). Clinical responses in the INT group were associated with an increase in the prevalence of activated NK cells in their peripheral blood.

CONCLUSIONS

Ex vivo TKD/IL2-activated, autologous NK cells are well tolerated and deliver positive clinical responses in patients with advanced NSCLC after RCT.

Immunomodulatory effects of some Namibian plants traditionally used for treating inflammatory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Acanthosicyos naudininus, Gomphocarpus fruticosus, and Cryptolepis decidua are, according to the knowledge of traditional healers, used in Namibia to treat inflammatory disorders such as pain, fever and skin rashes.

AIM OF THE STUDY

The present study was conducted to evaluate the immunomodulatory effects and the possible underlying mechanisms of action of the plant extracts on peripheral blood mononuclear cells (PBMCs) such as T-lymphocytes.

MATERIALS AND METHODS

Methanolic and EtOAc extracts of A. naudinianus, G. fruticosus and C. decidua were analysed for their immunomodulatory potential. PBMCs were isolated from the blood of healthy donors and incubated with the plant extracts at concentrations 100, 30, 10, 3, 1 and 0.3 μg/mL. Effects on proliferation and viability of activated human lymphocytes were assessed in comparison to ciclosporin A by flow cytometry using carboxyfluorescein succinimidyl ester (CFSE) and WST-1 assay. Flow cytometry by annexin V/propidium iodide (PI) staining was performed to investigate the necrotic/apoptotic effect of the plant extracts on mitogen-activated human lymphocytes. In addition, analysis of the influence of plant extracts on the regulatory mechanisms of T-lymphocytes was performed using activation marker and cytokine production assays. An HPLC-PDA-ELSD-ESIMS profile was recorded for each of the extracts.

RESULTS

T-lymphocyte proliferation was inhibited in a dose-dependent manner by the extracts of A. naudinianus, G. fruticosus, and C. decidua in concentrations not causing apoptosis or necrosis. This effect was mediated by inhibition of lymphocyte activation, specifically the suppression of CD25 and CD69 surface receptor expression. Moreover, the extracts suppressed effector functions, as indicated by reduced production of IFN-γ and IL-2. Based on the HPLC profile, possible responsible compound classes could be identified for the extracts of A. naudinianus (cucurbitacins) and C. decidua (indole alkaloids), but not for G. fruticosus.

CONCLUSIONS

The data show that the extracts of A. naudinianus, G. fruticosus and C. decidua have in vitro immunomodulatory activity and they interfere with the function of immunocompetent cells, suggesting an anti-inflammatory mode-of-action. The present chemical determination and pattern recognition results explain the therapeutic potency. However, further studies to investigate the therapeutic potential of the plants in inflammatory disorders should be done.

A multi-centre, parallel-group, randomised controlled trial to assess the efficacy and safety of eurythmy therapy and tai chi in comparison with standard care in chronically ill elderly patients with increased risk of falling (ENTAiER): a trial protocol

BACKGROUND

In elderly poeple, multimorbidity and polypharmacy increase while sensory, motor and cognitive functions decrease. Falls occur in 30% of people aged 65 years and older at least once per year, with injuries at 10-20%. Reducing falls and enhancing physical, emotional and cognitive capacities are essential for healthy aging despite chronic disease. Eurythmy therapy (EYT) and Tai Chi train balance, mobility and concentrative and sensory capacities.

METHODS

In eight trial sites (academic or community hospitals), 550 outpatients aged 65 years and older with chronic disease and increased risk of falling (history of imbalance, Berg Balance Scale (BBS) score ≤ 49) will be randomly assigned (1:1:1) to receive either EYT or Tai Chi (each provided in one-hour group sessions, twice, later once per week plus practice at home, for over 24 weeks) added to standard care or standard care alone. Standard care includes a detailed written recommendation on fall prevention and the visit of a primary care doctor. Seniors living a reclusive life or economically disadvantaged elderly will be particularly addressed. A motivation and communication concept supports the trial participants' compliance with trial procedures and practicing. Public and patient representatives are involved in the planning and conduction of the trial. Falls will be documented daily in a diary by the participants. These falls as well as injuries and complications will be ascertained during monthly phone visits. The falls efficacy scale, BBS, cognition (MoCA), Mood (GDS-15), quality of life (SF12), instrumental activities of daily living (IADL), use of medical and non-medical services (FIMA) and adherence will be assessed at months 3, 6, and 12 and inner correspondence with practices (ICPH) at month 6. The trial is funded by the Federal Ministry of Education and Research (BMBF 01GL1805).

DISCUSSION

This study will determine whether EYT and Tai Chi reduce falls, injurious falls, fear of falling and healthcare utilisation and improve mobility, cognition, mood, quality of life and functional independence. A reduction of fall risk and fear of falling and an improvement of mobility, autonomy, quality of life, mood, and cognition are highly relevant for older people to cope with aging and diseases and to reduce healthcare costs. TRAIL REGISTRATION: www.drks.de. DRKS00016609. Registered 30th July 2019.

Ultrafast transition between exciton phases in van der Waals heterostructures

Heterostructures of atomically thin van der Waals bonded monolayers have opened a unique platform to engineer Coulomb correlations, shaping excitonic^1-3, Mott insulating⁴ or superconducting phases^5,6. In transition metal dichalcogenide heterostructures⁷, electrons and holes residing in different monolayers can bind into spatially indirect excitons^1,3,8-11 with a strong potential for optoelectronics^11,12, valleytronics^1,3,13, Bose condensation¹⁴, superfluidity^14,15 and moiré-induced nanodot lattices¹⁶. Yet these ideas require a microscopic understanding of the formation, dissociation and thermalization dynamics of correlations including ultrafast phase transitions. Here we introduce a direct ultrafast access to Coulomb correlations between monolayers, where phase-locked mid-infrared pulses allow us to measure the binding energy of interlayer excitons in WSe₂/WS₂ hetero-bilayers by revealing a novel 1s-2p resonance, explained by a fully quantum mechanical model. Furthermore, we trace, with subcycle time resolution, the transformation of an exciton gas photogenerated in the WSe₂ layer directly into interlayer excitons. Depending on the stacking angle, intra- and interlayer species coexist on picosecond scales and the 1s-2p resonance becomes renormalized. Our work provides a direct measurement of the binding energy of interlayer excitons and opens the possibility to trace and control correlations in novel artificial materials.

Lightwave valleytronics in a monolayer of tungsten diselenide

As conventional electronics is approaching its ultimate limits1, nanoscience has urgently sought for novel fast control concepts of electrons at the fundamental quantum level2. Lightwave electronics3 – the foundation of attosecond science4 – utilizes the oscillating carrier wave of intense light pulses to control the translational motion of the electron’s charge faster than a single cycle of light5–15. Despite being particularly promising information carriers, the internal quantum attributes of spin16 and valley pseudospin17–19 have not been switchable on the subcycle scale20–21. Here we demonstrate lightwave-driven changes of the valley pseudospin and introduce distinct signatures in the optical read out. Photogenerated electron–hole pairs in a monolayer of tungsten diselenide are accelerated and collided by a strong lightwave. The emergence of high odd-order sidebands and anomalous changes in their polarization direction directly attest to the ultrafast pseudospin dynamics. Quantitative computations combining density-functional theory with a non-perturbative quantum many-body approach assign the polarization of the sidebands to a lightwave-induced change of the valley pseudospin and confirm that the process is coherent and adiabatic. Our work opens the door to systematic valleytronic logic at optical clock rates.

Symmetry-controlled time structure of high-harmonic carrier fields from a solid

High-harmonic (HH) generation in crystalline solids1-6 marks an exciting development, with potential applications in high-efficiency attosecond sources7, all-optical bandstructure reconstruction8,9, and quasiparticle collisions10,11. Although the spectral1-4 and temporal shape5 of the HH intensity has been described microscopically1-6,12, the properties of the underlying HH carrier wave have remained elusive. Here we analyse the train of HH waveforms generated in a crystalline solid by consecutive half cycles of the same driving pulse. Extending the concept of frequency combs13-15 to optical clock rates, we show how the polarization and carrier-envelope phase (CEP) of HH pulses can be controlled by crystal symmetry. For some crystal directions, we can separate two orthogonally polarized HH combs mutually offset by the driving frequency to form a comb of even and odd harmonic orders. The corresponding CEP of successive pulses is constant or offset by π, depending on the polarization. In the context of a quantum description of solids, we identify novel capabilities for polarization- and phase-shaping of HH waveforms that cannot be accessed with gaseous sources.

Terahertz-Driven Nonlinear Spin Response of Antiferromagnetic Nickel Oxide

Terahertz magnetic fields with amplitudes of up to 0.4 Tesla drive magnon resonances in nickel oxide while the induced dynamics is recorded by femtosecond magneto-optical probing. We observe distinct spin-mediated optical nonlinearities, including oscillations at the second harmonic of the 1 THz magnon mode. The latter originate from coherent dynamics of the longitudinal component of the antiferromagnetic order parameter, which are probed by magneto-optical effects of second order in the spin deflection. These observations allow us to dynamically disentangle electronic from lattice-related contributions to magnetic linear birefringence and dichroism-information so far only accessible by ultrafast THz spin control. The nonlinearities discussed here foreshadow physics that will become essential in future subcycle spin switching.

Hypocalcaemia of malignancy

BACKGROUND

Hypercalcaemia of malignancy is well recognised, but hypocalcaemia in cancer patients is not, although it is increasingly encountered.

METHODS

Analysis of an exemplary case and a narrative review of the literature based on the search terms cancer and hypocalcaemia.

RESULTS

Hypocalcaemia may affect as many as 10% of hospitalised cancer patients. We identified 12 different potential mechanisms of hypocalcaemia of malignancy. Identifying the pathogenesis is essential for the correct treatment and can usually be performed at the bedside, based on serum parathyroid hormone (PTH) levels, creatinine, phosphate, magnesium, creatine kinase, liver enzymes and 25(OH)D. Essentially, decreased or normal PTH hypocalcaemia is seen after removal or destruction of its source, hypomagnesaemia, or cinacalcet treatment. In all other cancer-associated hypocalcaemia, PTH is elevated, including significant renal impairment, critically ill patients, extensive cell destruction (rhabdomyolysis, tumour lysis, haemolysis), acute pancreatitis, adverse drug reactions, cancer or cancer treatment-related malabsorption syndromes, vitamin D deficiency, or osteoblastic metastases. Different mechanisms may often operate in tandem. Pathogenesis determines treatment and affects prognosis. However, hypocalcaemia of malignancy as such did not imply a worse prognosis, in contrast with hypercalcaemia.

CONCLUSION

Hypocalcaemia in cancer patients is commonly encountered, particularly in hospitalised patients, may be mediated by diverse mechanisms and should be better recognised.

Efficacy of a Nasal Spray from Citrus limon and Cydonia oblonga for the Treatment of Hay Fever Symptoms-A Randomized, Placebo Controlled Cross-Over Study

Nasal spray from lemon and quince (LQNS) is used to treat hay fever symptoms and has been shown to inhibit histamine release from mast cells in vitro. Forty-three patients with grass pollen allergy (GPA) were randomized to be treated either with placebo or LQNS for one week, respectively, in a cross-over study. At baseline and after the respective treatments patients were provoked with grass pollen allergen. Outcome parameters were nasal flow measured with rhinomanometry (primary), a nasal symptom score, histamine in the nasal mucus and tolerability. In the per protocol population absolute inspiratory nasal flow 10 and 20 min after provocation was higher with LQNS compared to placebo (-37 ± 87 mL/s; p = 0.027 and -44 ± 85 mL/s; p = 0.022). The nasal symptom score showed a trend (3.3 ± 1.8 in the placebo and 2.8 ± 1.5 in the LQNS group; p = 0.070) in favor of LQNS; the histamine concentration was not significantly different between the groups. Tolerability of both, LQNS and placebo, was rated as very good. LQNS seems to have an anti-allergic effect in patients with GPA. Copyright © 2016 John Wiley & Sons, Ltd.

Lightwave-driven quasiparticle collisions on a subcycle timescale

Ever since Ernest Rutherford scattered α-particles from gold foils, collision experiments have revealed insights into atoms, nuclei and elementary particles. In solids, many-body correlations lead to characteristic resonances--called quasiparticles--such as excitons, dropletons, polarons and Cooper pairs. The structure and dynamics of quasiparticles are important because they define macroscopic phenomena such as Mott insulating states, spontaneous spin- and charge-order, and high-temperature superconductivity. However, the extremely short lifetimes of these entities make practical implementations of a suitable collider challenging. Here we exploit lightwave-driven charge transport, the foundation of attosecond science, to explore ultrafast quasiparticle collisions directly in the time domain: a femtosecond optical pulse creates excitonic electron-hole pairs in the layered dichalcogenide tungsten diselenide while a strong terahertz field accelerates and collides the electrons with the holes. The underlying dynamics of the wave packets, including collision, pair annihilation, quantum interference and dephasing, are detected as light emission in high-order spectral sidebands of the optical excitation. A full quantum theory explains our observations microscopically. This approach enables collision experiments with various complex quasiparticles and suggests a promising new way of generating sub-femtosecond pulses.

Frequency and predictors of acute ischaemic lesions on brain magnetic resonance imaging in young patients with a clinical diagnosis of transient ischaemic attack

BACKGROUND AND PURPOSE

Acute lesions in patients with transient ischaemic attack (TIA) are important as they are associated with increased risk for recurrence. Characteristics associated with acute lesions in young TIA patients were therefore investigated.

METHODS

The sifap1 study prospectively recruited a multinational European cohort (n = 5023) of patients aged 18-55 years with acute cerebrovascular event. The detection of acute ischaemic lesions was based on diffusion-weighted imaging (DWI). The frequency of DWI lesions was assessed in 829 TIA patients who met the criteria of symptom duration <24 h and their association with demographic, clinical and imaging variables was analysed.

RESULTS

The median age was 46 years (interquartile range 40-51 years); 45% of the patients were female. In 121 patients (15%) ≥1 acute DWI lesion was detected. In 92 patients, DWI lesions were found in the anterior circulation, mostly located in cortical-subcortical areas (n = 63). Factors associated with DWI lesions in multiple regression analysis were left hemispheric presenting symptoms [odds ratio (OR) 1.92, 95% confidence interval (CI) 1.27-2.91], dysarthria (OR 2.17, 95% CI 1.38-3.43) and old brain infarctions on MRI (territories of the middle and posterior cerebral artery: OR 2.43, 95% CI 1.42-4.15; OR 2.41, 95% CI 1.02-5.69, respectively).

CONCLUSIONS

In young patients with a clinical TIA 15% demonstrated acute DWI lesions on brain MRI, with an event pattern highly suggestive of an embolic origin. Except for the association with previous infarctions there was no clear clinical predictor for acute ischaemic lesions, which indicates the need to obtain MRI in young individuals with TIA.

Ultrafast Mid-Infrared Nanoscopy of Strained Vanadium Dioxide Nanobeams

Long regarded as a model system for studying insulator-to-metal phase transitions, the correlated electron material vanadium dioxide (VO2) is now finding novel uses in device applications. Two of its most appealing aspects are its accessible transition temperature (∼341 K) and its rich phase diagram. Strain can be used to selectively stabilize different VO2 insulating phases by tuning the competition between electron and lattice degrees of freedom. It can even break the mesoscopic spatial symmetry of the transition, leading to a quasiperiodic ordering of insulating and metallic nanodomains. Nanostructuring of strained VO2 could potentially yield unique components for future devices. However, the most spectacular property of VO2--its ultrafast transition--has not yet been studied on the length scale of its phase heterogeneity. Here, we use ultrafast near-field microscopy in the mid-infrared to study individual, strained VO2 nanobeams on the 10 nm scale. We reveal a previously unseen correlation between the local steady-state switching susceptibility and the local ultrafast response to below-threshold photoexcitation. These results suggest that it may be possible to tailor the local photoresponse of VO2 using strain and thereby realize new types of ultrafast nano-optical devices.

Resonant internal quantum transitions and femtosecond radiative decay of excitons in monolayer WSe2

Atomically thin two-dimensional crystals have revolutionized materials science. In particular, monolayer transition metal dichalcogenides promise novel optoelectronic applications, owing to their direct energy gaps in the optical range. Their electronic and optical properties are dominated by Coulomb-bound electron-hole pairs called excitons, whose unusual internal structure, symmetry, many-body effects and dynamics have been vividly discussed. Here we report the first direct experimental access to all 1s A excitons, regardless of momentum--inside and outside the radiative cone--in single-layer WSe2. Phase-locked mid-infrared pulses reveal the internal orbital 1s-2p resonance, which is highly sensitive to the shape of the excitonic envelope functions and provides accurate transition energies, oscillator strengths, densities and linewidths. Remarkably, the observed decay dynamics indicates an ultrafast radiative annihilation of small-momentum excitons within 150 fs, whereas Auger recombination prevails for optically dark states. The results provide a comprehensive view of excitons and introduce a new degree of freedom for quantum control, optoelectronics and valleytronics of dichalcogenide monolayers.