Label-free and amplification-free viral RNA quantification from primate biofluids using a trapping-assisted optofluidic nanopore platform

Viral outbreaks can cause widespread disruption, creating the need for diagnostic tools that provide high performance and sample versatility at the point of use with moderate complexity. Current gold standards such as PCR and rapid antigen tests fall short in one or more of these aspects. Here, we report a label-free and amplification-free nanopore sensor platform that overcomes these challenges via direct detection and quantification of viral RNA in clinical samples from a variety of biological fluids. The assay uses an optofluidic chip that combines optical waveguides with a fluidic channel and integrates a solid-state nanopore for sensing of individual biomolecules upon translocation through the pore. High specificity and low limit of detection are ensured by capturing RNA targets on microbeads and collecting them by optical trapping at the nanopore location where targets are released and rapidly detected. We use this device for longitudinal studies of the viral load progression for Zika and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infections in marmoset and baboon animal models, respectively. The up to million-fold trapping-based target concentration enhancement enables amplification-free RNA quantification across the clinically relevant concentration range down to the assay limit of RT-qPCR as well as cases in which PCR failed. The assay operates across all relevant biofluids, including semen, urine, and whole blood for Zika and nasopharyngeal and throat swab, rectal swab, and bronchoalveolar lavage for SARS-CoV-2. The versatility, performance, simplicity, and potential for full microfluidic integration of the amplification-free nanopore assay points toward a unique approach to molecular diagnostics for nucleic acids, proteins, and other targets.

Generation of time-independent torque by ultrasonic guided waves

The excitation of acoustic waves by a unidirectional transducer, integrated in a piezoelectric cylindrical tube or disk, can lead to a time-independent torque. This phenomenon, demonstrated earlier in experiments and analyzed with coupling-of mode theory, is explained in detail, starting on the level of lattice dynamics of a piezoelectric crystal. Expressions are derived for the stationary torque in the form of integrals over the volume or surface of the piezoelectric, involving the electric potential and displacement field associated with the acoustic waves generated by the transducer. Simulations have been carried out with the help of the finite element method for a tube made of PZT for two cases: A pre-defined potential on the surface of the tube and metal electrodes buried in the piezoelectric. The displacement field and electric potential of the high-frequency acoustic waves (between 200 and 300 kHz) were computed and used in the evaluation of the integrals. The attenuation due to various loss channels of the acoustic waves in the system has been analyzed in detail, as this plays a crucial role for the efficiency of torque generation. It is conjectured that time-reversal symmetry, present in the absence of attenuation, prohibits the generation of a static torque at least in the linear limit. A qualitative comparison is made between the simulations and earlier experiments. Discrepancies are attributed to lack of knowledge of the relevant material constants of the piezoelectric and to a simplified modeling of the electrode geometry in the cylindrical tube, which was necessary for reasons of numerical accuracy.

Idiosyncratic Drug-Induced Liver Injury in a Healthy Patient following PCSK9-Inhibitor Injection

Background

Acute liver injury is a life-threatening condition with disparate aetiology. Swift and adequate interdisciplinary treatment is essential to assure the best possible outcomes in these patients. Investigations to identify the cause of the condition and the implementation of quick and appropriate treatment can be lifesaving. Case Presentation. In October 2022, an otherwise healthy 66-year-old male presented at the University Hospital Essen with acute liver injury following an inclisiran injection for hypercholesterinaemia. Four weeks following admission, the patient fully recovered after initially receiving short-term cortisol therapy and open albumin (OPAL) dialysis, and the indices of liver, kidney, and coagulation function were normal at discharge.

Conclusion

This is to our knowledge the first reported acute liver injury due to an inclisiran injection. Cortisol in combination with OPAL dialysis is an effective method for the treatment of acute liver injury caused by inclisiran injury, and in this case, it led to a near-complete reversal of the acute liver injury at the time of discharge.

Nano/microfluidic device for high-throughput passive trapping of nanoparticles

We present a design and a fabrication method for devices designed for rapid collection of nanoparticles in a fluid. The design uses nanofluidic channels as a passive size-based barrier trap to isolate particles near a central point in the channel, which is also covered by a thin membrane. Particles that enter the collection region are trapped with 100% efficiency within a 6-12 μ m radius from a central point. Flow rates for particle-free fluid range from 1.88 to 3.69 nl/s for the pressure and geometries tested. Particle trapping tests show that high trapped particle counts significantly impact flow rates. For suspensions as dilute as 30-300 aM (20-200 particles/μ l), 8-80 particles are captured within 500 s.

Impact of encorafenib on survival of patients with BRAFV600E-mutant metastatic colorectal cancer in a real-world setting

PURPOSE

Patients with BRAFV600E-mutant metastatic colorectal cancer (mCRC) have a dismal prognosis. The best strategies in these patients remain elusive. Against this background, we report the clinical course of patients with BRAFV600E-mutant mCRC to retrieve the best treatment strategy.

PATIENTS AND METHODS

Clinico-pathological data were extracted from the electronic health records. Kaplan-Meier method was used to estimate overall (OS) and progression-free survival (PFS). Objective response rate (ORR) was assessed according to RECIST 1.1.

RESULTS

In total, 51 patients were enrolled. FOLFOXIRI was administered to 12 patients; 29 patients received FOLFOX or FOLFIRI as first-line treatment. Median OS was 17.6 months. Median PFS with FOLFOXIRI (13.0 months) was significantly prolonged (HR 0.325) as compared to FOLFOX/FOLFIRI (4.3 months). However, this failed to translate into an OS benefit (p = 0.433). Interestingly, addition of a monoclonal antibody to chemotherapy associated with superior OS (HR 0.523). A total of 64.7% patients received further-line therapy, which included a BRAF inhibitor in 17 patients. Targeted therapy associated with very favourable OS (25.1 months).

CONCLUSION

Patients with BRAFV600E-mutated mCRC benefit from the addition of an antibody to first-line chemotherapy. Further-line treatment including a BRAF inhibitor has a dramatic impact on survival.

Dual optofluidic distributed feedback dye lasers for multiplexed biosensing applications

Integrated optofluidic devices have become subjects of high interest for rapid biosensor devices due to their unique ability to combine the fluidic processing of small volumes of microfluidics with the analysis capabilities of photonic structures. By integrating dynamically reconfigurable optofluidic lasers on-chip, complex coupling can be eliminated while further increasing the capabilities of sensors to detect an increasing number of target biomarkers. Here, we report a polydimethylsiloxane-based device with two on-chip fluidic distributed feedback (DFB) laser cavities that are integrated with an orthogonal analyte channel for multiplexed fluorescence excitation. One DFB grating is filled with 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran dissolved in dimethyl sulfoxide. The second grating is filled with rhodamine 6G dissolved in a diluted ethylene glycol solution. We present characterization of both lasers through analysis of the lasing spectra for spectral narrowing along with a power series to observe threshold behavior. We then demonstrate simultaneous detection of two different fluorescent microbeads as a proof of concept for scalable, single biomarker analysis using on-chip optofluidic lasers.

Impact of Tracer Dose Reduction in [18 F]-Labelled Fluorodeoxyglucose-Positron Emission Tomography ([18 F]-FDG)-PET) on Texture Features and Histogram Indices: A Study in Homogeneous Tissues of Phantom and Patient

BACKGROUND

Histogram indices (HIs) and texture features (TFs) are considered to play an important role in future oncologic PET-imaging and it is unknown how these indices are affected by changes of tracer doses. A randomized undersampling of PET list mode data enables a simulation of tracer dose reduction. We performed a phantom study to compare HIs/TFs of simulated and measured tracer dose reductions and evaluated changes of HIs/TFs in the liver of patients with PETs from simulated reduced tracer doses. Overall, 42 HIs/TFs were evaluated in a NEMA phantom at measured and simulated doses (stepwise reduction of [18 F] from 100% to 25% of the measured dose). [18 F]-FDG-PET datasets of 15 patients were simulated from 3.0 down to 0.5 MBq/kgBW in intervals of 0.25 MBq/kgBW. HIs/TFs were calculated from two VOIs placed in physiological tissue of the right and left liver lobe and linear correlations and coefficients of variation analysis were performed.

RESULTS

All 42 TFs did not differ significantly in measured and simulated doses (p > 0.05). Also, 40 TFs showed the same behaviour over dose reduction regarding differences in the same group (measured or simulated), and for 26 TFs a linear behaviour over dose reduction for measured and simulated doses could be validated. Out of these, 13 TFs could be identified, which showed a linear change in TF value in both the NEMA phantom and patient data and therefore should maintain the same informative value when transferred in a dose reduction setting. Out of this Homogeneity 2, Entropy and Zone size non-uniformity are of special interest because they have been described as preferentially considerable for tumour heterogeneity characterization.

CONCLUSIONS

We could show that there was no significant difference of measured and simulated HIs/TFs in the phantom study and most TFs reveal a linear behaviour over dose reduction, when tested in homogeneous tissue. This indicates that texture analysis in PET might be robust to dose modulations.

Open-loop lab-on-a-chip technology enables remote computer science training in Latinx life sciences students

Despite many interventions, science education remains highly inequitable throughout the world. Among all life sciences fields, Bioinformatics and Computational Biology suffer from the strongest underrepresentation of racial and gender minorities. Internet-enabled project-based learning (PBL) has the potential to reach underserved communities and increase the diversity of the scientific workforce. Here, we demonstrate the use of lab-on-a-chip (LoC) technologies to train Latinx life science undergraduate students in concepts of computer programming by taking advantage of open-loop cloud-integrated LoCs. We developed a context-aware curriculum to train students at over 8,000 km from the experimental site. We showed that this approach was sufficient to develop programming skills and increase the interest of students in continuing careers in Bioinformatics. Altogether, we conclude that LoC-based Internet-enabled PBL can become a powerful tool to train Latinx students and increase the diversity in STEM.

Comparison of Illumination Methods for Flow-Through Optofluidic Biosensors

Optofluidic biosensors have become an important medical diagnostic tool because they allow for rapid, high-sensitivity testing of small samples compared to standard lab testing. For these devices, the practicality of use in a medical setting depends heavily on both the sensitivity of the device and the ease of alignment of passive chips to a light source. This paper uses a model previously validated by comparison to physical devices to compare alignment, power loss, and signal quality for windowed, laser line, and laser spot methods of top-down illumination.

Machine learning at the edge for AI-enabled multiplexed pathogen detection

Multiplexed detection of biomarkers in real-time is crucial for sensitive and accurate diagnosis at the point of use. This scenario poses tremendous challenges for detection and identification of signals of varying shape and quality at the edge of the signal-to-noise limit. Here, we demonstrate a robust target identification scheme that utilizes a Deep Neural Network (DNN) for multiplex detection of single particles and molecular biomarkers. The model combines fast wavelet particle detection with Short-Time Fourier Transform analysis, followed by DNN identification on an AI-specific edge device (Google Coral Dev board). The approach is validated using multi-spot optical excitation of Klebsiella Pneumoniae bacterial nucleic acids flowing through an optofluidic waveguide chip that produces fluorescence signals of varying amplitude, duration, and quality. Amplification-free 3× multiplexing in real-time is demonstrated with excellent specificity, sensitivity, and a classification accuracy of 99.8%. These results show that a minimalistic DNN design optimized for mobile devices provides a robust framework for accurate pathogen detection using compact, low-cost diagnostic devices.

Patient-reported outcome measures for physical function in cancer patients: content comparison of the EORTC CAT Core, EORTC QLQ-C30, SF-36, FACT-G, and PROMIS measures using the International Classification of Functioning, Disability and Health

BACKGROUND

Patient-reported physical function (PF) is a key endpoint in cancer clinical trials. Using complex statistical methods, common metrics have been developed to compare scores from different patient-reported outcome (PRO) measures, but such methods do not account for possible differences in questionnaire content. Therefore, the aim of our study was a content comparison of frequently used PRO measures for PF in cancer patients.

METHODS

Relying on the framework of the International Classification of Functioning, Disability and Health (ICF) we categorized the item content of the physical domains of the following measures: EORTC CAT Core, EORTC QLQ-C30, SF-36, PROMIS Cancer Item Bank for Physical Function, PROMIS Short Form for Physical Function 20a, and the FACT-G. Item content was linked to ICF categories by two independent reviewers.

RESULTS

The 118 items investigated were assigned to 3 components ('d - Activities and Participation', 'b - Body Functions', and 'e - Environmental Factors') and 11 first-level ICF categories. All PF items of the EORTC measures but one were assigned to the first-level ICF categories 'd4 - Mobility' and 'd5 - Self-care', all within the component 'd - Activities and Participation'. The SF-36 additionally included item content related to 'd9 - Community, social and civic life' and the PROMIS Short Form for Physical Function 20a also included content related to 'd6 - domestic life'. The PROMIS Cancer Item Bank (v1.1) covered, in addition, two first-level categories within the component 'b - Body Functions'. The FACT-G Physical Well-being scale was found to be the most diverse scale with item content partly not covered by the ICF framework.

DISCUSSION

Our results provide information about conceptual differences between common PRO measures for the assessment of PF in cancer patients. Our results complement quantitative information on psychometric characteristics of these measures and provide a better understanding of the possibilities of establishing common metrics.

Diagnosis concealment is prevalent in MS, and associated with diagnosis experience

BACKGROUND

Receiving a diagnosis of multiple sclerosis (MS) can be stressful; later, patients may conceal their diagnosis. Here, we aimed to (1) assess prevalence of disclosure and concealment behaviors, and (2) explore whether diagnosis experience is associated with later concealment and if MS provider engagement on this topic modifies concealment.

METHODS

In a survey-based study, MS patients completed DISCO-MS assessing disclosure and concealment and responded to questions about diagnosis experience and practitioner attention to disclosure. Frequency analysis and Pearson's correlations were used in exploratory analyses.

RESULTS

428 adults with MS participated. 49% (N = 201) conceal their diagnosis. Higher education [t(405) = 3.66, p < 0.001], younger age (r = -0.15, p = 0.002), and shorter disease duration (r = -0.18, p = 0.010) were associated with higher concealment. 39% (N = 159) anticipate negative consequences of disclosure. Individuals reporting positive diagnosis experience (26%, N = 102) were less likely to conceal later in disease course compared to those with negative experience (34%, N = 136) [t(233) = 2.483, p = 0.014]. Patients whose MS providers discussed disclosure (23%, N = 73) anticipated less negative consequences of disclosure [t(323) = 2.475, p = 0.014].

CONCLUSIONS

Diagnosis concealment is common in MS. Favorable diagnosis experience and provider attention to the topic of disclosure throughout the MS disease course may influence diagnosis concealment.

Selection of patients for mechanical circulatory support for refractory out-of-hospital cardiac arrest: a Danish nationwide multicenter study

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) is a potential salvage therapy for selected patients with refractory out-of-hospital cardiac arrest (OHCA).

Purpose

The objective of this study was to describe the characteristics of potential ECPR patients.

Methods

This retrospective, observational cohort study included 579 patients admitted with refractory OHCA for possible ECPR at all tertiary cardiac arrest centers in Denmark between 2015 and 2020. Presenting characteristics, reasons for refraining from ECPR, and survival to hospital discharge were recorded.

Results

After initial evaluation, 221 patients (38%) proceeded to ECPR, and 358 (62%) were considered futile. Median prehospital low-flow time was 70 minutes [interquartile range 56–85] in ECPR patients and 62 minutes [48–81] in no-ECPR patients, p&lt;0.001. Intra arrest transport was more than 50 km in 92 (42%) ECPR patients and 135 in no-ECPR patients (38%), p=0.25. Treatment decision was taken by a team of three specialists in 513 cases (97%). The leading cause for not initiating ECPR was duration of low flow time (39%). Severe metabolic derangement and low end-tidal CO2 (ETCO2) were contributing factors in 35% and 31%, respectively, Figure 1. 83% of the patients had two or more contributing factors recorded as reasons for not initiating ECPR, Figure 2. The most prevailing combination of contributing factors were non-shockable rhythm, low ETCO2, and metabolic derangement or duration of prehospital low flow time combined with low ETCO2. Survival to discharge was achieved in six patients (1.7%) in the no-ECPR group and 50 (23%) in the ECPR group.

Conclusions

In this large nationwide study of patients admitted for possible ECPR, 62% were not treated with ECPR. The most frequent reasons to abstain from ECPR were duration of prehospital low flow time, metabolic derangement, and low ETCO2.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation

Severity of oEsophageal Anastomotic Leak in patients after oesophagectomy: the SEAL score

Background

Anastomotic leak (AL) is a common but severe complication after oesophagectomy. It is unknown how to determine the severity of AL objectively at diagnosis. Determining leak severity may guide treatment decisions and improve future research. This study aimed to identify leak-related prognostic factors for mortality, and to develop a Severity of oEsophageal Anastomotic Leak (SEAL) score.

Methods

This international, retrospective cohort study in 71 centres worldwide included patients with AL after oesophagectomy between 2011 and 2019. The primary endpoint was 90-day mortality. Leak-related prognostic factors were identified after adjusting for confounders and were included in multivariable logistic regression to develop the SEAL score. Four classes of leak severity (mild, moderate, severe, and critical) were defined based on the risk of 90-day mortality, and the score was validated internally.

Results

Some 1509 patients with AL were included and the 90-day mortality rate was 11.7 per cent. Twelve leak-related prognostic factors were included in the SEAL score. The score showed good calibration and discrimination (c-index 0.77, 95 per cent c.i. 0.73 to 0.81). Higher classes of leak severity graded by the SEAL score were associated with a significant increase in duration of ICU stay, healing time, Comprehensive Complication Index score, and Esophagectomy Complications Consensus Group classification.

Conclusion

The SEAL score grades leak severity into four classes by combining 12 leak-related predictors and can be used to the assess severity of AL after oesophagectomy.

FPGA Integrated Optofluidic Biosensor for Real-Time Single Biomarker Analysis

Integrated optofluidic biosensors can fill the need for sensitive, amplification-free, multiplex single molecule detection which is relevant for containing the spread of infectious diseases such as COVID-19. Here, we demonstrate a rapid sample-to-answer scheme that uses a field programmable gate array (FPGA) to enable live monitoring of single particle fluorescence analysis on an optofluidic chip. Fluorescent nanobeads flowing through a micro channel are detected with 99% accuracy and particle concentrations in clinically relevant ranges from 3.4×104 to 3.4 × 106/ml are determined within seconds to a few minutes without the need for post-experiment data extraction and analysis. In addition, other extract salient experimental parameters such as dynamic flow rate changes can be monitored in real time. The sensor is validated with real-time fluorescence detection of single bacterial plasmid DNA at attomolar concentrations, showing excellent promise for implementation as a point of care (POC) diagnostic tool.

Optical trapping assisted label-free and amplification-free detection of SARS-CoV-2 RNAs with an optofluidic nanopore sensor

Ultrasensitive, versatile sensors for molecular biomarkers are a critical component of disease diagnostics and personalized medicine as the COVID-19 pandemic has revealed in dramatic fashion. Integrated electrical nanopore sensors can fill this need via label-free, direct detection of individual biomolecules, but a fully functional device for clinical sample analysis has yet to be developed. Here, we report amplification-free detection of SARS-CoV-2 RNAs with single molecule sensitivity from clinical nasopharyngeal swab samples on an electro-optofluidic chip. The device relies on optically assisted delivery of target carrying microbeads to the nanopore for single RNA detection after release. A sensing rate enhancement of over 2,000x with favorable scaling towards lower concentrations is demonstrated. The combination of target specificity, chip-scale integration and rapid detection ensures the practicality of this approach for COVID-19 diagnosis over the entire clinically relevant concentration range from 10⁴-10⁹ copies/mL.

Greatly Enhanced Single Particle Fluorescence Detection Using High Refractive Index Liquid-Core Waveguides

High sensitivity and easy integration with microfabrication techniques has made silicon photonics one of the leading technologies used to build biosensors for diagnostic applications. Here we introduce a new silicon dioxide based optofluidic platform having a planar solid-core (SC) waveguide orthogonally intersecting a liquid-core (LC) waveguide with high refractive index ZnI2 salt solution as core. This enables both more uniform collection of particle fluorescence by the core mode and its propagation to an off-chip detector. This approach results in ultra-high sensitivity performance, demonstrated by achieving 8X enhancement in signal-to-noise ratio, a 45x increase in detection efficiency, and a 100x lower detection limit of 80 aM of fluorescent nanobeads. This represents a key step towards an ultrasensitive biosensor system for analyzing pathogens at clinical concentrations.

[Smarter Medicine in Headache Care - presentation and discussion of 5 recommendations]

Smarter Medicine in Headache Care - presentation and discussion of 5 recommendations Abstract. An unequivocal headache diagnosis cannot always be made. The lack of diagnostic tests able to prove primary headaches often prompts physicians to perform unnecessary examinations to reduce their uncertainty. When setting out the therapeutic strategy, again, insecurity often leads to mendable choices. In this Delphi study, members of the therapy commission of the Swiss Headache Society collected, rated, and re-rated doubtful and questionable procedures. Five recommendations that resulted from this survey are presented and reviewed in this article. The recommendations are: (A) no repeated cerebral imaging in headaches with unchanged phenotype; (B) no computed tomography in the work-up of non-acute headaches; (C) no tooth extraction to treat persistent idiopathic facial pain, (D) no migraine surgery; (E) no removal of amalgam fillings to treat headache disorders.

Recent advances in integrated solid-state nanopore sensors

The advent of single-molecule probing techniques has revolutionized the biomedical and life science fields and has spurred the development of a new class of labs-on-chip based on powerful biosensors. Nanopores represent one of the most recent and most promising single molecule sensing paradigms that is seeing increased chip-scale integration for improved convenience and performance. Due to their physical structure, nanopores are highly sensitive, require low sample volume, and offer label-free, amplification-free, high-throughput real-time detection and identification of biomolecules. Over the last 25 years, nanopores have been extensively employed to detect a variety of biomolecules with a growing range of applicatons ranging from nucleic acid sequencing to ultrasensitive diagnostics to single-molecule biophysics. Nanopores, in particular those in solid-state membranes, also have the potential for integration with other technologies such as optics, plasmonics, microfluidics, and optofluidics to perform more complex tasks for an ever-expanding demand. A number of breakthrough results using integrated nanopore platforms have already been reported, and more can be expected as nanopores remain the focus of innovative research and are finding their way into commercial instruments. This review provides an overview of different aspects and challenges of nanopore technology with a focus on chip-scale integration of solid-state nanopores for biosensing and bioanalytical applications.

Free-Space Excitation of Optofluidic Devices for Pattern-Based Single Particle Detection

Optofluidic sensors have enabled single molecule sensing using planar, waveguide dependent multi-spot fluorescence excitation. Here, we demonstrate a new approach to single-particle fluorescence sensing using free-space, top-down illumination of liquid-core antiresonant reflecting optical waveguide (ARROW) devices using two different multi-spot excitation techniques. First, the liquid core ARROW waveguide is excited with a focused beam through a slit pattern milled into an opaque aluminum film, showing comparable performance for single bead fluorescence detection as in-plane, multi-mode interference waveguide based excitation. The second top-down illumination technique images the spot pattern from a Y-splitter SiO₂ waveguide chip directly onto the detection device for efficient power utilization and circumventing the need for an opaque cover, producing a further 2.7x improvement in signal-to-noise ratio. The two top-down approaches open up new possibilities for chip-based optical particle sensing with relaxed alignment tolerances.

Performance Comparison of Flow-Through Optofluidic Biosensor Designs

Optofluidic flow-through biosensors are being developed for single particle detection, particularly as a tool for pathogen diagnosis. The sensitivity of the biosensor chip depends on design parameters, illumination format (side vs. top), and flow configuration (parabolic, two- and three-dimensional hydrodynamic focused (2DHF and 3DHF)). We study the signal differences between various combinations of these design aspects. Our model is validated against a sample of physical devices. We find that side-illumination with 3DHF produces the strongest and consistent signal, but parabolic flow devices process a sample volume more quickly. Practical matters of optical alignment are also discussed, which may affect design choice.

Optofluidic Amplification-free Multiplex Detection of Viral Hemorrhagic Fevers

Infectious disease outbreaks such as Ebola and other Viral Hemorrhagic Fevers (VHF) require low-complexity, specific, and differentiated diagnostics as illustrated by the recent outbreak in the Democratic Republic of Congo. Here, we describe amplification-free spectrally multiplex detection of four different VHF total RNA samples using multi-spot excitation on a multimode interference waveguide platform along with combinatorial fluorescence labeling of target nucleic acids. In these experiments, we observed an average of 8-fold greater fluorescence signal amplitudes for the Ebola total RNA sample compared to three other total RNA samples: Lake Victoria Marburg Virus, Ravn Marburg Virus, and Crimean-Congo Hemorrhagic Fever. We have attributed this amplitude amplification to an increased amount of RNA during synthesis of soluble glycoprotein in infection. This hypothesis is confirmed by single molecule detection of the total RNA sample after heat-activated release from the carrier microbeads. From these experiments, we observed at least a 5.3x higher RNA mass loading on the Ebola carrier microbeads compared to the Lake Victoria Marburg carrier microbeads, which is consistent with the known production of soluble glycoprotein during infection.

Global Impact of COVID-19 on Stroke Care and IV Thrombolysis

OBJECTIVE

To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods.

METHODS

We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases.

RESULTS

There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions.

CONCLUSIONS

The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months.

Ultrasensitive detection of SARS-CoV-2 RNA and antigen using single-molecule optofluidic chip

Nucleic acids and proteins are the two most important target types used in molecular diagnostics. In many instances, simultaneous sensitive and accurate detection of both biomarkers from the same sample would be desirable, but standard detection methods are highly optimized for one type and not cross-compatible. Here, we report the simultaneous multiplexed detection of SARS-CoV-2 RNAs and antigens with single molecule sensitivity. Both analytes are isolated and labeled using a single bead-based solid-phase extraction protocol, followed by fluorescence detection on a multi-channel optofluidic waveguide chip. Direct amplification-free detection of both biomarkers from nasopharyngeal swab samples is demonstrated with single molecule detection sensitivity, opening the door for ultrasensitive dual-target analysis in infectious disease diagnosis, oncology, and other applications.

Very (70W) vs. LSI guided (5-6) high power short duration ablation in patients with paroxysmal atrial fibrillation undergoing pulmonary vein vs. pulmonary vein and posterior wall isolation

Funding Acknowledgements

Type of funding sources: None.

Background

high power short duration (HPSD) ablation is at least as safe while reducing procedure time than radiofrequency (RF) ablation with lower power in pts undergoing pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF). Purpose: to compare safety and efficacy of 2 different: 1) RF energy set up (FlexAbility: 70W, 41°, 6-10s, 11ml/h vs. TactiCath: 50W, 41°, LSI 5-6, 17ml/h, both Abbott), and 2) ablation strategies (posterior wall isolation (PWI) in addition to PVI vs. PVI) in pts undergoing their first ablation for paroxysmal AF. Methods: since June 2020 pts are prospectively assigned to alternatively undergo their RF catheter ablation with the FlexAbility (v-HPSD) or the TactiCath (LSI-HPSD) catheters (aim 200 pts). In addition, pts were alternatively assigned to PVI + PWI vs. PVI. All procedures were done using a 3D-mapping system (Ensite Precision), the ablation catheter was stabilized with a long sheath (Agilis) and a continuous series of lesions (4mm) were plotted around the PV, at the roof and between the 2 inferior PVs. On the PW, RF lesions were limited to 6s and 5 LSI for the v-HPSD and LSI-HPSD groups. Endoscopy was performed shortly after ablation in all pts and thermal esophageal lesion (TEL) characterized with the Kansas classification. Results: since June 2020 56 pts [61 ± 13 years old, 17 (30%) female, CHA2DS2-Vasc 2.3 ± 1.5, 55 ± 77 left ventricular ejection fraction] underwent v-HPSD (#28) and LSI-HPSD (#28) ablation. In 2/14 (14%) and in 3/15 (20%) pts (v-HPSD and LSI-HPSD groups, respectively) initially assigned to undergo simple PVI, PWI was added due to PW dependent flutter or evidence of pro-arrhythmic slow conduction on the PW. A shorter RF time to achieve PVI (17 ± 3 vs. 25 ± 6 min; P&lt;.0001) was found for the v-HPSD group, although acute reconnection were numerically higher (9 vs. 4) and procedural time did not differ (32 ± 8 vs. 35 ± 9 min). Whenever attempted, PWI (#16 for each v-HPSD and LSI-HPSD group) was always successful. When v-HPSD and LSI-HPSD group were compared, no differences were found in RF and procedure time both at the roof (2.3 ± 0.9 vs. 2.7 ± 1.1 min and 3 ± 1.4 vs. 3.4 ± 1 min, respectively) and between the 2 inferior PVs (2.6 ± 0.6 vs. 2.9 ± 0.7 min and 4.3 ± 1.9 vs. 3.8 ± 1.2 min, respectively). Total RF (19.7 ± 4.5 vs. 28.5 ± 6.6 min, P&lt;.0001) was shorted in the v-HPSD, but X-Ray (1.4 ± 0.7 vs. 1.2 ± 0.8 min) and total procedural time (102 ± 17 vs. 110 ± 20 min) did not differ. Rate of TELs was not different and found in 18% (#5: 4 I, 1 IIA) and 14% (all IIA) pts assigned to v-HPSD and LSI-HPSD respectively. A numerically higher number of TELs (6 vs. 3) was seen when PWI was pursued, although this did not prolong total RF and procedure time. Conclusion: a shorter RF time is associated with v-HPSD vs. LSI-HPSD strategy, although procedural time did not differ. TELs are a relative rare finding, and only numerically higher when isolation of the PW is pursued in addition to PV isolation.

Optofluidic Flow-Through Biosensor Sensitivity - Model and Experiment

We present a model and simulation for predicting the detected signal of a fluorescence-based optical biosensor built from optofluidic waveguides. Typical applications include flow experiments to determine pathogen concentrations in a biological sample after tagging relevant DNA or RNA sequences. An overview of the biosensor geometry and fabrication processes is presented. The basis for the predictive model is also outlined. The model is then compared to experimental results for three different biosensor designs. The model is shown to have similar signal statistics as physical tests, illustrating utility as a pre-fabrication design tool and as a predictor of detection sensitivity.

A Pilot Study of 18F-DCFPyL PET/CT or PET/MRI and Ultrasound Fusion Targeted Prostate Biopsy for Intra-Prostatic PET-Positive Lesions

Objectives

The purpose of this study was to evaluate the feasibility and diagnostic performance of prostate-specific membrane antigen (PSMA) based ¹⁸F-DCFPyL PET/CT-ultrasound (PET/CT-US) or PET/MRI-ultrasound (PET/MRI-US) fusion targeted biopsy for intra-prostatic PET-positive lesions.

Methods

From April 2018 to November 2019, we prospectively enrolled 55 candidates to perform PET/CT-US or PET/MRI-US fusion targeted biopsies for solitary PET-positive prostate lesions (two to four cores/lesion). The positive rates of prostate cancer based on patients and biopsy cores were calculated respectively. With reference to the pathological results of biopsy cores, the MR signal characteristics in the area of the PET-positive lesion were analyzed for the patients who underwent PET/MRI.

Results

A total of 178 biopsy cores were taken on the 55 patients. One hundred forty-six biopsy cores (82.0%, 146/178) from 51 (92.7%, 51/55) patients were positive for prostate cancer; 47 (85.5%, 47/55) were clinically significant prostate cancer. It is noteworthy that nine patients underwent both ¹⁸F-DCFPyL PET/CT and PET/MRI examinations; the seven patients with prostate cancer showed abnormal MR signal in the area of the PET-positive lesion while the other two patients with prostatic hyperplasia and prostatitis showed normal MR signal in the area of the PET-positive lesion.

Conclusion

This study indicated that ¹⁸F-DCFPyL PET/CT-US or PET/MRI-US fusion targeted prostate biopsies may be valuable for prostate cancer diagnosis and have a high detection rate of clinically significant prostate cancer for PET-positive lesions. PET/MR can rule out some false PET-positive lesions, which may potentially reduce unnecessary prostate biopsies.

Pre-procedural proton pump inhibition is associated with fewer peri-oesophageal lesions after cryoballoon pulmonary vein isolation

Pulmonary vein isolation (PVI) using cryoenergy is safe and efficient for treatment of atrial fibrillation (AF). Pre-existing upper gastrointestinal (GI) pathologies have been shown to increase the risk for AF. Therefore, this study aimed at assessing incidental pathologies of the upper GI tract in patients scheduled for PVI and to analyse the impact of patients’ characteristics on PVI safety outcome. In 71 AF patients, who participated in the MADE-PVI trial, oesophagogastroduodenoscopy and endosonography were prospectively performed directly before and the day after PVI to assess pre-existing upper GI pathologies and post-interventional occurrence of PVI-associated lesions. Subgroup analysis of the MADE-PVI trial identified clinically relevant incidental findings in 53 patients (74.6%) with age > 50 years being a significant risk factor. Pre-existing reflux oesophagitis increased risk for PVI-associated mediastinal oedema, while patients already treated with proton pump inhibitors (PPI) had significantly fewer mediastinal oedema. Our results suggest that AF patients with pre-existing reflux oesophagitis are at higher risk for PVI-associated mediastinal lesions, which is decreased in patients with constant PPI-treatment prior to PVI. Since PVI-associated mediastinal lesions are regarded as surrogate parameter for an increased risk of the fatal complication of an oesophago-atrial fistula, our findings hint at a beneficial effect of pre-interventional prophylactic PPI-treatment to reduce risk for PVI-associated complications.

German Clinical Trials Register (DRKS00016006; date of registration: 17/12/2018).

Rationale and design of an interventional study of cross-sectoral, coordinated treatment of stroke patients with patient-orientated outcome measurement (StroCare)

INTRODUCTION

Stroke has a long-term impact on functional status and quality of life in multiple health domains. A well-coordinated managed care program for stroke patients is crucial for ameliorating patients' health and cost-efficient use of resources. The aim of this study is the implementation and evaluation of an optimised cross-sectoral, coordinated and managed care program for stroke patients bridging secondary and tertiary care.

METHODS

In this multi-center mixed method sequentially controlled intervention study, stroke patients with ischemic stroke (I63), transient ischemic attack and related syndromes (G45), or intracerebral haermorrhage (I64) will be invited to participate. For a 12-months period, 235 consecutive patients are expected to be enrolled and assigned standard of care treatment as an active control group. During the following 12 months, 235 consecutive patients will be enrolled and assigned to a post stroke intervention program. The StroCare intervention consists of repeated outpatient visits with specialized stroke teams, the implementation of a case manager, the use of an electronical tool for communication between acute care, rehabilitation facilities, and out-patient care, and the definition of individualized treatment targets. Patients will be followed up for 24 months. The primary outcome is health-related quality of life measured by the Patient-Reported Outcomes Measurement Information System 10-Question Short Form (PROMIS-10) at 12 months after the index event, i.e. stroke or TIA. For the qualitative survey of the implementation process, 21 patients in the intervention group will be interviewed after implementation of the interventions. In addition, 20 health care providers and staff members will be interviewed before and after implementation. Additionally, economic outcomes will be evaluated after 6 and 12 months.

PERSPECTIVE

The study will not only provide information about the tested intervention but is likely to be helpful for clinicians, suppliers of reimbursement, and researchers in implementing and evaluating complex interventions in stroke care in general. With this program, the health care system will have a reference model at its disposal for transfer to other regions and settings.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov ( NCT04159324 ). Approval of the local ethics committee (Ethik-Kommission der Ärztekammer Hamburg, Niedersachsen, Schleswig-Holstein) has been obtained.

Impact of urgent coronary artery bypass grafting on acute kidney injury : A matched cohort study

OBJECTIVES

There is limited knowledge regarding the specific interrelationships between urgent coronary artery bypass graft (U-CABG) surgery and postoperative acute kidney injury (AKI). We aimed to (1) analyze the impact of urgent CABG (U-CABG) on the incidence and severity of postoperative AKI, (2) estimate the influence of AKI after U‑CABG or elective CABG (E-CABG) on mortality and (3) identify risk factors for AKI depending on the urgency of operation.

RESULTS

U‑CABG patients showed a higher incidence of AKI (49.8% vs. E‑CABG: 39.7%; p = 0.026), especially for higher AKI stages 2 + 3. In-hospital mortality was higher in U‑CABG patients (12.6%) compared to E‑CABG patients (2.3%; p < 0.001). The impact of AKI on mortality did not differ, but showed a strong coherency between higher AKI stages (2 + 3) and mortality (stage 1: OR 2.409, 95% CI 1.017-5.706; p = 0.046 vs. stage 2 + 3: OR 5.577; 95% CI 2.033-15.3; p = 0.001). Univariate logistic regression analysis revealed that preoperative renal impairment, peripheral vascular disease and transfusion of more than two red blood cell concentrates were predictors for postoperative AKI in both groups.

CONCLUSIONS

U‑CABG is a risk factor for postoperative AKI and even "mild" AKI leads to a significantly higher mortality. Hence, the prevention of modifiable risk factors might reduce the incidence of postoperative AKI and thus improve outcome.

Model-based convolutional neural network approach to underwater source-range estimation

This paper is part of a special issue on machine learning in acoustics. A model-based convolutional neural network (CNN) approach is presented to test the viability of this method as an alternative to conventional matched-field processing (MFP) for underwater source-range estimation. The networks are trained with simulated data generated under a particular model of the environment. When tested with data simulated in environments that deviate slightly from the training environment, this approach shows improved prediction accuracy and lower mean-absolute-error (MAE) compared to MFP. The performance of this model-based approach also transfers to real data, as demonstrated separately with field data collected in the Beaufort Sea and off the coast of Southern California. For the former, the CNN predictions are consistent with expected source range while for the latter, the CNN estimates have lower MAE compared to MFP. Examination of the trained CNNs' intermediate outputs suggests that the approach is more constrained than MFP from outputting very inaccurate predictions when there is a slight environmental mismatch. This improvement appears to be at the expense of decreased certainty in the correct source range prediction when the environment is precisely modeled.

Temporal and spatial characteristics of the Beaufort Sea ambient noise environment

Underwater ambient noise from the Beaufort Sea, collected in March 2016, is analyzed to investigate the effect that environmental changes in the region have on the spatial and temporal characteristics of the ice-generated ambient noise. In particular, the influx of warm Pacific water, so called the Beaufort Lens, has dramatically altered the level and vertical directionality of ambient noise, creating a low noise zone in the ∼75-250 m depth interval with a noise notch at low grazing angles. It is also demonstrated how the observed noise vertical directionality is consistent with ice-mechanical activity along an active pressure ridge ∼30-50 km from the recording array, as shown by satellite imagery. The discrete ranges to this ice activity explain the peak arrival angles between -10 to -15 degrees in noise vertical directionality, as well as the horizontal noise notch. Transient noise events associated with the ice activity are analyzed using an image processing approach with hierarchical clustering applied to the recorded spectrograms. The observed events are grouped into three categories-short-time-broadband, long-time-narrowband, and long-time-broadband-each likely generated through a different mechanism by the ice cover. The spectral and temporal distribution of these transients are discussed.

Effects of Post-Etch Microstructures on the Optical Transmittance of Silica Ridge Waveguides

Silica waveguides are often etched by reactive ion etch (RIE) processes. These processes can leave residual topography that can increase optical loss. We investigated the relation between optical loss and various RIE etch. A wet etch step meant to remove microstructures was also considered and compared. Ridge waveguides were fabricated in plasma enhanced chemical vapor deposited films by three different RIE processes, each with a different gas composition, pressure setting, and applied power setting. Half of each set of waveguides were also subjected to a hydrofluoric acid (HF) solution. The waveguides were tested for optical transmission via the cutback method. The transmission vs waveguide length measurements were plotted to fit an exponential curve and the optical loss and measurement uncertainty for each waveguide set was calculated. Clear distinctions in optical loss were found between the different RIE processes. The HF treatment also has an effect, significantly reducing optical loss for two processes and increasing it for the third. Of the tested RIE processes, one can be suggested for silica waveguides. It results in the lowest optical loss and coincidently has the fastest etch rate.

Pneumatically tunable optofluidic DFB dye laser using corrugated sidewalls

Polydimethylsiloxane-based optofluidics provides a powerful platform for a complete analytical lab-on-chip. Here, we report on a novel on-chip laser source that can be integrated with sample preparation and analysis functions. A corrugated sidewall structure is integrated into a microfluidic channel to form a distributed feedback (DFB) laser using rhodamine 6G dissolved in an ethylene glycol and water solution. Lasing is demonstrated with a threshold pump power of 87.9 µW, corresponding to a pump intensity of 52.7mW/cm². Laser threshold and output power are optimized with respect to rhodamine 6G concentration and core index and found to be in good agreement with a rate equation model. Additionally, the laser can be switched on and off mechanically using a pneumatic cell inducing positive pressure on the grating.

Solid-state membranes formed on natural menisci

We present a method to create robust, nanoscale solid-state membranes using the natural shape of a liquid meniscus as a template. A narrow, open channel is etched into a silicon substrate and then a photoresist polymer is introduced into the channel through spontaneous capillary action. The natural concave meniscus formed by the polymer is then covered by a thin chemical vapor deposited membrane. The polymer is removed by sacrificial etching, leaving behind a suspended membrane. Membranes as large as 20 μm by 9 mm can be fabricated with a thickness as low as 50 nm.

7X multiplexed, optofluidic detection of nucleic acids for antibiotic-resistance bacterial screening

Rapid and accurate diagnosis of bacterial infections resistant to multiple antibiotics requires development of new bio-sensors for differentiated detection of multiple targets. This work demonstrates 7x multiplexed detection for antibiotic-resistance bacterial screening on an optofluidic platform. We utilize spectrally multiplexed multi-spot excitation for simultaneous detection of nucleic acid strands corresponding to bacterial targets and resistance genes. This is enabled by multi-mode interference (MMI) waveguides integrated in an optofluidic device. We employ a combinatorial three-color labeling scheme for the nucleic acid assays to scale up their multiplexing capability to seven different nucleic acids, representing three species and four resistance genes.

3× multiplexed detection of antibiotic resistant plasmids with single molecule sensitivity

Bacterial pathogens resistant to antibiotics have become a serious health threat. Those species which have developed resistance against multiple drugs such as the carbapenems, are more lethal as these are last line therapy antibiotics. Current diagnostic tests for these resistance traits are based on singleplex target amplification techniques which can be time consuming and prone to errors. Here, we demonstrate a chip based optofluidic system with single molecule sensitivity for amplification-free, multiplexed detection of plasmids with genes corresponding to antibiotic resistance, within one hour. Rotating disks and microfluidic chips with functionalized polymer monoliths provided the upstream sample preparation steps to selectively extract these plasmids from blood spiked with E. coli DH5α cells. Waveguide-based spatial multiplexing using a multi-mode interference waveguide on an optofluidic chip was used for parallel detection of three different carbapenem resistance genes. These results point the way towards rapid, amplification-free, multiplex analysis of antibiotic-resistant pathogens.

[Neurological complications of hepatitis C infections]

Die chronische Hepatitis-C-Virus(HCV)-Infektion ist eine hochprävalente Systemerkrankung, die verschiedene neurologische Komplikationen verursachen kann. Es lassen sich HCV-assoziierte Symptome im zentralen und peripheren Nervensystem sowie der Muskulatur unterscheiden. Wichtige Pathomechanismen sind die HCV-assoziierte Autoimmunität (z. B. gemischte Kryoglobulinämie mit Polyneuropathie) und direkte Neurotoxizität (z. B. bei HCV-assoziierten kognitiven Defiziten). Die häufigsten neurologischen Komplikationen sind distal-symmetrische Polyneuropathien, Small-fiber-Neuropathien und kognitive Defizite. Die HCV-Infektion stellt außerdem einen Risikofaktor für ischämische und hämorrhagische Schlaganfälle sowie den Morbus Parkinson dar. Die frühe Identifikation und antivirale Behandlung HCV-positiver Patienten steht im Zentrum der Behandlung. Durch neue antivirale Therapien können >90 % der Patienten dauerhaft von der HCV-Infektion geheilt werden.

A device-based stretch training for office workers resulted in increased range of motion especially at limited baseline flexibility

BACKGROUND

It is unclear whether and under which conditions stretch training programs lead to gains in flexibility when applied in work health promotion for office workers in order to reduce musculoskeletal disorders (MSD).

OBJECTIVE

The aim of this study was to analyze whether the stretch training "five-Business" leads to gains in range of motion (ROM). Furthermore, the influence of baseline flexibility and socio-demographic factors (sex, age, weight, height and body mass index (BMI)) on trainability was assessed.

METHODS

161 office workers (n = 45 female; n = 116 male) without major MSD were recruited. Over three months, a standardized static stretch training ("five-Business") was executed on a device, supervised twice per week for 10 min. ROM was assessed using a digital inclinometer (shoulder, hip and trunk extension) and a tape measure (fingertip-to-floor and lateral inclination).

RESULTS

ROM gains (p≤0.001) were present in all tests, except for the hip extension. ROM changes correlated moderately (0.24-0.62) with the baseline flexibility (p≤0.001). Subjects with limited flexibility reached the largest gains (1.41-25.33%). Regarding the socio-demographic factors only one low correlation occurred (weight - retroflexion; -0.177).

CONCLUSION

The "five-Business" stretch training effectively increases ROM in office workers, especially when baseline flexibility is limited.