Visualization of Diffusion within Nanoarrays

The direct experimental characterization of diffusion processes at nanoscale remains a challenge that could help elucidate processes in biology, medicine and technology. In this report, two experimental approaches were employed to visualize ion diffusion profiles at the orifices of nanopores (radius (ra) of 86 ± 6 nm) in array format: (1) electrochemically assisted formation of silica deposits based on surfactant ion transfer across nanointerfaces between two immiscible electrolyte solutions (nanoITIES); (2) combined atomic force - scanning electrochemical microscopy (AFM-SECM) imaging of topography and redox species diffusion through the nanopores. The nature of the diffusion zones formed around the pores is directly related to the interpore distance within the array. Nanopore arrays with different ratios of pore center-to-center separation (rc) to pore radius (ra) were fabricated by focused ion beam (FIB) milling of silicon nitride (SiN) membranes, with 100 pores in a hexagonal arrangement. The ion diffusion profiles determined by the two visualization methods indicated the formation of overlapped or independent diffusion profiles at nanopore arrays with rc/ra ratios of 21 ± 2 and 91 ± 7, respectively. In particular, the silica deposition method resulted in formation of a single deposit encompassing the complete array with closer nanopore arrangement, whereas individual silica deposits were formed around each nanopore within the more widely spaced array. The methods reveal direct experimental evidence of diffusion zones at nanopore arrays and provide practical illustration that the pore-pore separation within such arrays has a significant impact on diffusional transport as the pore size is reduced to the nanoscale. These approaches to nanoscale diffusion zone visualization open up possibilities for better understanding of molecular transport processes within miniaturized systems

Evidence of the causal role of human papillomavirus type 58 in an oropharyngeal carcinoma

Persistent human papillomavirus infection (HPV) is recognized as an important etiologic factor for a subset of head and neck squamous cell carcinomas (SCC), especially those arising from the oropharynx. Whereas HPV16 accounts for the majority of HPV DNA-positive oropharyngeal SCC, infections with other mucosal high-risk HPV types are quite rare and biological data demonstrating their causal involvement are insufficient. Here we present the first case of an oropharyngeal SCC driven by HPV type 58. A 69-year-old Caucasian woman presented with an enlarged and firm left tonsil. A computed tomography scan showed a left tonsillar mass, extending to the soft palate and the glossotonsillar sulcus. The patient underwent extended radical tonsillectomy and ipsilateral selective neck dissection. Pathology confirmed an infiltrating, poorly differentiated SCC of the left tonsil with node metastasis (pT2N1). Adjuvant external beam radiation therapy (60 Grays (Gy)) was administered. After 1 year of follow-up, the patient is well with no evidence of cancer recurrence. HPV analyses of the tumor tissue by BSGP5+/6+-PCR/MPG, targeting 51 mucosal HPV types, showed single positivity for HPV type 58. Presence of HPV58 E6*I RNA demonstrated biological activity of the virus in the tumor tissue, and presence of serum antibodies to HPV58 oncoproteins E6 and E7 indicated presence of an HPV58-driven cancer. Overexpression of cellular protein p16(INK4a) and reduced expression of pRb, two cellular markers for HPV-induced cell transformation, were observed. Exons 4-10 of TP53 showed no mutations or polymorphisms. The presence of HPV58 as single HPV infection in combination with a broad variety of direct and indirect markers of HPV transformation provides comprehensive evidence that this oropharyngeal SCC was driven by HPV58

Sensitivity and specificity of antibodies against HPV16 E6 and other early proteins for the detection of HPV16-driven oropharyngeal squamous cell carcinoma

To determine the sensitivity and specificity of HPV16 serology as diagnostic marker for HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), 214 HNSCC patients from Germany and Italy with fresh-frozen tumor tissues and sera collected before treatment were included in this study. Hundred and twenty cancer cases were from the oropharynx and 94 were from head and neck cancer regions outside the oropharynx (45 oral cavity, 12 hypopharynx and 35 larynx). Serum antibodies to early (E1, E2, E6 and E7) and late (L1) HPV16 proteins were analyzed by multiplex serology and were compared to tumor HPV RNA status as the gold standard. A tumor was defined as HPV-driven in the presence of HPV16 DNA and HPV16 transformation-specific RNA transcript patterns (E6*I, E1∧E4 and E1C). Of 120 OPSCC, 66 (55%) were HPV16-driven. HPV16 E6 seropositivity was the best predictor of HPV16-driven OPSCC (diagnostic accuracy 97% [95%CI 92–99%], Cohen's kappa 0.93 [95%CI 0.8–1.0]). Of the 66 HPV-driven OPSCC, 63 were HPV16 E6 seropositive, compared to only one (1.8%) among the 54 non-HPV-driven OPSCC, resulting in a sensitivity of 96% (95%CI 88–98) and a specificity of 98% (95%CI 90–100). Of 94 HNSCC outside the oropharynx, six (6%) were HPV16-driven. In these patients, HPV16 E6 seropositivity had lower sensitivity (50%, 95%CI 19–81), but was highly specific (100%, 95%CI 96–100). In conclusion, HPV16 E6 seropositivity appears to be a highly reliable diagnostic marker for HPV16-driven OPSCC with very high sensitivity and specificity, but might be less sensitive for HPV16-driven HNSCC outside the oropharynx

The European Academy for Cognitive Behavioural Therapy for Insomnia : An initiative of the European Insomnia Network to promote implementation and dissemination of treatment

Insomnia, the most prevalent sleep disorder worldwide, confers marked risks for both physical and mental health. Furthermore, insomnia is associated with considerable direct and indirect healthcare costs. Recent guidelines in the US and Europe unequivocally conclude that cognitive behavioural therapy for insomnia (CBT‐I) should be the first‐line treatment for the disorder. Current treatment approaches are in stark contrast to these clear recommendations, not least across Europe, where, if any treatment at all is delivered, hypnotic medication still is the dominant therapeutic modality. To address this situation, a Task Force of the European Sleep Research Society and the European Insomnia Network met in May 2018. The Task Force proposed establishing a European CBT‐I Academy that would enable a Europe‐wide system of standardized CBT‐I training and training centre accreditation. This article summarizes the deliberations of the Task Force concerning definition and ingredients of CBT‐I, preconditions for health professionals to teach CBT‐I, the way in which CBT‐I should be taught, who should be taught CBT‐I and to whom CBT‐I should be administered. Furthermore, diverse aspects of CBT‐I care and delivery were discussed and incorporated into a stepped‐care model for insomnia.Peer reviewe

Investigation of localized electrochemical interfaces with advanced microscopic techniques : AFM-SECM and FIB/SEM tomography

Combined scanning probe techniques (SPM) enable the investigation of localized surface properties. Amongst other hybrid methods, atomic force - scanning electrochemical microscopy (AFM-SECM) is highly attractive for studying processes at the solid/liquid interface, and also for investigations of liquid/liquid interfaces. In order to enhance the field of applications, AFM-SECM probes may be modified facilitating the requirements for biomedical applications and for usage with electroanalytical techniques. Whereas AFM-SECM provides predominantly information of surface processes, the combination of focused ion beam (FIB) and scanning electron microscopy (SEM) enables the detection and reconstruction of the inner structure of (nano)porous materials. Within the first part of this thesis, the focus of research is targeted towards modification of AFM-SECM probes facilitating biomedically relevant measurements, such as sensing hydrogen peroxide (H2O2) release or generation in close proximity to a sample surface (chapter 4), and localized pH sensing with associated surface changes (chapter 5). In chapter 6, detailed investigations of FIB-milled nanoporous arrays in silicon nitride (SiN) membranes are presented, which were used as solid-state support for electrochemistry at the interface between two immiscible electrolyte solutions (ITIES). The suitability of AFM-SECM in the investigation of micro- and nanoscale interfaces is shown by the performance of AFM-SECM with a conductive AFM tip, which was used to visualize the diffusion behavior at these nanoporous arrays. In addition, the localized electrochemical deposition of silica at the nanoITIES was used to visualize the location of the interface within the nanopores. FIB/SEM tomography was performed for the investigations of the location of this interface at such silica deposits

Universal Nanopore Platform Integrating Multiple Resistive Pulse Sensors into a Single Microfluidic Device

Resistive pulse sensors have been used to characterise everything from whole cells to small molecules. Their integration into microfluidic devices have simplified sample handling whilst increasing throughput. Typically, these devices measure a limited size range or a specific analyte, making them prone to blockages in complex sample matrixes. To prolong their life and facilitate their use, samples are often filtered or prepared to match the sample with the sensor diameter. Here, we advance our tuneable flow resistive pulse sensor which utilises additively manufactured parts. The sensor allows parts to be easily changed, washed and cleaned, its simplicity and versatility allows components from existing nanopore fabrication techniques such as silicon nitride, polyurethane and glass pipettes to be integrated into a single device. This creates a multi-nanopore sensor that can simultaneously measure particles from 0.1 to 30 m in diameter. The orientation and controlled fluid flow in the device allows the sensors to be placed in series, whereby smaller particles can be measured in the presence of larger ones without the risk of being blocked. We demonstrate the device with a range of nanopore materials commonly found within the literature, the easiest to set up was the pulled glass pipette and glass nanopore membrane. However, the glass nanopore membrane was by far the most robust and reusable component tested. We illustrate the concept of a multi-pore flow resistive pulse sensor, by combining an additively manufactured tuneable sensor, termed sensor 1, with a fixed nanopore sensor, termed sensor 2. Sensor 1 measures particles 2 to 30 m in diameter, whilst sensor 2 can be used to characterise particles as small as 100 nm, depending upon its dimensions

Cognitive behavioural therapy for insomnia disorder: Extending the stepped care model

Baglioni C, Espie CA, Altena E, et al. Cognitive behavioural therapy for insomnia disorder: Extending the stepped care model. Journal of Sleep Research. 2023.Despite cognitive behaviour therapy for insomnia (CBT-I) being the first-line intervention for the disorder, it is often not readily available to patients in need. The stepped care model (SCM) represents an approach to facilitating efficient and wide-ranging provision of evidence-based care to those with insomnia. The SCM reflects a pyramid of therapeutics based on CBT-I gradually increasing in clinical intensity and addressing clinical complexity. By applying CBT-I through the SCM it is hoped that the treatment gap can be bridged such that not only more patients can be reached, but that clinical resource can be more effectively distributed, with patients receiving more tailored care as needed. Nevertheless, this should not be done at the risk of a lower quality of care being offered, and high-standard training for clinicians and scrutiny of non-clinician led interventions remains important. As national health laws within European countries have substantial differences, the application of the SCM as it relates to the treatment of insomnia may be challenged by contrasting interpretations. In order that the SCM is appropriately implemented: (a) only evidence-based CBT-I treatments should be promoted within the model; (b) clinicians involved in SCM should be suitably qualified to offer CBT in general, and have appropriate further training in CBT-I; (c) professionals involved in interventions not included in the SCM, but related to it, such as preventive and educational programmes, diagnostic procedures, and pharmacological treatments, should also have good knowledge of the SCM in order to promote correct allocation to the appropriate interventional step

Ultramicrosensors based on transition metal hexacyanoferrates for scanning electrochemical microscopy

We report here a way for improving the stability of ultramicroelectrodes (UME) based on hexacyanoferrate-modified metals for the detection of hydrogen peroxide. The most stable sensors were obtained by electrochemical deposition of six layers of hexacyanoferrates (HCF), more specifically, an alternating pattern of three layers of Prussian Blue and three layers of Ni–HCF. The microelectrodes modified with mixed layers were continuously monitored in 1 mM hydrogen peroxide and proved to be stable for more than 5 h under these conditions. The mixed layer microelectrodes exhibited a stability which is five times as high as the stability of conventional Prussian Blue-modified UMEs. The sensitivity of the mixed layer sensor was 0.32 A·M−1·cm−2, and the detection limit was 10 µM. The mixed layer-based UMEs were used as sensors in scanning electrochemical microscopy (SECM) experiments for imaging of hydrogen peroxide evolution

Dealing with sleep problems during home confinement due to the COVID-19 outbreak: Practical recommendations from a task force of the European CBT-I Academy

Altena E, Baglioni C, Espie CA, et al. Dealing with sleep problems during home confinement due to the COVID-19 outbreak: Practical recommendations from a task force of the European CBT-I Academy. JOURNAL OF SLEEP RESEARCH. 2020: e13052.In the current global home confinement situation due to the COVID-19 outbreak, most individuals are exposed to an unprecedented stressful situation of unknown duration. This may not only increase daytime stress, anxiety and depression levels, but also disrupt sleep. Importantly, because of the fundamental role that sleep plays in emotion regulation, sleep disturbance can have direct consequences upon next day emotional functioning. In this paper, we summarize what is known about the stress-sleep link and confinement as well as effective insomnia treatment. We discuss those effects of the current home confinement situation that can disrupt sleep but also those that could benefit sleep quality. We suggest adaptions of cognitive behavioural therapy elements that are feasible to implement for those facing changed work schedules and requirements, those with health anxiety and those handling childcare and home-schooling, whilst also recognizing the general limitations imposed on physical exercise and social interaction. Managing sleep problems as best as possible during home confinement can limit stress and possibly prevent disruptions of social relationships

Electrosynthesis of Biocompatible Free-Standing PEDOT Thin Films at a Polarised Liquid|Liquid Interface

[Image: see text] Conducting polymers (CPs) find applications in energy conversion and storage, sensors, and biomedical technologies once processed into thin films. Hydrophobic CPs, like poly(3,4-ethylenedioxythiophene) (PEDOT), typically require surfactant additives, such as poly(styrenesulfonate) (PSS), to aid their aqueous processability as thin films. However, excess PSS diminishes CP electrochemical performance, biocompatibility, and device stability. Here, we report the electrosynthesis of PEDOT thin films at a polarized liquid|liquid interface, a method nonreliant on conductive solid substrates that produces free-standing, additive-free, biocompatible, easily transferrable, and scalable 2D PEDOT thin films of any shape or size in a single step at ambient conditions. Electrochemical control of thin film nucleation and growth at the polarized liquid|liquid interface allows control over the morphology, transitioning from 2D (flat on both sides with a thickness of 850 nm) films. The PEDOT thin films were p-doped (approaching the theoretical limit), showed high π–π conjugation, were processed directly as thin films without insulating PSS and were thus highly conductive without post-processing. This work demonstrates that interfacial electrosynthesis directly produces PEDOT thin films with distinctive molecular architectures inaccessible in bulk solution or at solid electrode–electrolyte interfaces and emergent properties that facilitate technological advances. In this regard, we demonstrate the PEDOT thin film’s superior biocompatibility as scaffolds for cellular growth, opening immediate applications in organic electrochemical transistor (OECT) devices for monitoring cell behavior over extended time periods, bioscaffolds, and medical devices, without needing physiologically unstable and poorly biocompatible PSS