Pandemic Effect on Healthcare Use and Death in Adults with Epilepsy: A Population Study.

OBJECTIVES: We conducted a population-based study using Ontario health administrative data to describe trends in healthcare utilization and mortality in adults with epilepsy during the first pandemic year (March 2020-March 2021) compared to historical data (2016-2019). We also investigated if changes in outpatient visits and diagnostic testing during the first pandemic year were associated with increased risk for hospitalizations, emergency department (ED) visits, or death. METHODS: Projected monthly visit rates (per 100,000 people) for outpatient visits, electroencephalography, magnetic resonance, computed tomography, all-cause ED visits, hospitalizations, and mortality were calculated based on historical data by fitting monthly time series autoregressive integrated moving-average models. Two-way interactions were calculated using Quasi-Poisson models. RESULTS: In adults with epilepsy during the first quarter of the pandemic, we demonstrated a reduction in all-cause outpatient visits, diagnostic testing, ED visits and hospitalizations, and a temporary increase in mortality (observed rates of 355.8 vs projected 308.8, 95% CI: 276.3-345.1). By the end of the year, outpatient visits increased (85,535.4 vs 76,620.6, 95% CI: 71,546.9-82,059.4), and most of the diagnostic test rates returned to the projected. The increase in the rate of all-cause mortality during the pandemic, compared to pre-pandemic, was greater during months with the lower frequency of diagnostic tests than months with higher frequency (interaction p-values <.0001). CONCLUSION: We described the impact of the pandemic on healthcare utilization and mortality in adults with epilepsy during the first year. We demonstrated that access to relevant diagnostic testing is likely important for this population while planning restrictions on non-urgent health services.

Labelling of eicosapentaenoic acid with stable isotope 13C in the marine bacterium Shewanella marinintestina.

Eicosapentaenoic acid (EPA) is an essential omega-3 polyunsaturated fatty acid that plays a critical role in marine life. It is present in several marine animals, including fish, but the primary producers of EPA are phytoplankton and specific marine bacteria. Although most of the EPA present in marine animals come from phytoplankton, the bacterial input into the marine EPA food web is still unknown. The labelling of EPA within a bacterial strain could be a viable strategy to help revealing this contribution. In this work, Shewanella marinintestina IRL 567, a marine bacterium isolated from fish guts and known to produce EPA, was labelled with the stable isotope 13C at small (250-mL shake flask), bench (2.5-L shake flask), and pilot scale (50-L stirred tank bioreactor). Growing the bacterium with 13C-acetate in the culture medium demonstrated that EPA was de-novo synthesized utilizing acetate as precursor. 13C incorporation into the EPA molecule resulted in values as high as 95.5% of the synthesized EPA being labelled in small scale, 95.9% in bench scale and 91.5% in pilot scale. This simple method to label EPA proved to be effective and therefore it could be a valuable tool to follow the fate of bacterial EPA into higher trophic levels.

Influence of Limb Position on Venous Blood Flow After Total Knee Arthroplasty: A Prospective Randomized Study.

Previous studies have suggested a clinical advantage when placing the limb in flexion after total knee arthroplasty (TKA). We sought to measure venous flow compared with control values after TKA. Our hypothesis was that the knee flexed positioning would not adversely affect venous flow. Two cohorts were prospectively evaluated. First, volunteers were randomized to positions with the knee flexed to approximately 90° or placed in a fully extended (control) position. Venous flow velocity was measured in the femoral vein every 15 minutes for 2 hours. Subsequently, 32 patients were randomized to 1 of these 2 positions after TKA, and venous flow velocity was measured in both the operative and the contralateral limb. In the healthy volunteer cohort, mean venous flow velocity was significantly higher at all time points in the flexion group compared with the extended control group (P<.05). After TKA, mean flow velocity for an extended knee (control) was 28.5 cm/s. Mean flow velocity for the flexed knee, foot-dependent group was 47.2 cm/s (P=.036) and for the flexed knee, foot-elevated group was 30.4 cm/s (P=.618). Placing the limb in a flexed position after TKA is not detrimental to venous flow velocity and resulted in higher velocities relative to the extended position. Placing the limb at 90° flexion does not cause venous stasis and should not increase the risk of deep venous thrombosis. [Orthopedics. 2023;46(1):8-12.].

Alberta Stroke Program Early CT Score (ASPECTS) in real time: A prospective study of its interobserver variation among radiologists in a training hospital from a low-resource setting

Background and Objectives: The Alberta Stroke Program Early CT Score (ASPECTS) is a standardized system used to quantify the extent of ischemic involvement in cases of acute middle cerebral artery (MCA) infarct. It aids in clinical decision-making to identify patients who are more likely to benefit from thrombolytic therapy. This study aimed to determine the interobserver variation of ASPECTS among training and expert radiologists in a real-time, low-resource setting.Patients and Methods: A prospective study was conducted on non-enhanced CT (NECT) images of 79 patients with acute stroke. Patients with hemorrhagic stroke, or ischemic stroke from territories other than the MCA, were excluded. The ASPECTS of each case was assessed by three groups of radiologists--residents, fellows, and an expert. The level of agreement among them was then analyzed.Results: ASPECT scores were dichotomized into >7 and ?7. With the expert's reading as gold standard, residents had sensitivity of 0.94 [95% CI: 0.85, 0.99] and specificity of 0.68 [95% CI: 0.46, 0.85], while fellows had sensitivity of 0.96 [95% CI: 0.87, 1.00] and specificity of 0.76 [95% CI: 0.55, 0.91]. There was substantial agreement between residents and expert in overall ASPECTS rating (? = 0.66 [95% CI: 0.48, 0.85]; AC1 = 0.77 [95% CI: 0.62, 0.91]), and substantial to almost perfect agreement between fellows and expert (? = 0.76 [95% CI: 0.59, 0.92]; AC1 = 0.83 [95% CI: 0.71, 0.95]). Differences between the ASPECTS of the expert and trainees were within 2 points in most cases.Conclusion: ASPECTS is a reliable tool for both training and expert radiologists to quantify the extent of MCA infarcts. Assessment by trainees is comparable with that of the expert reader and is useful for immediate clinical decision making in low-resource settings.

To do, or not to do, that is the question: Appropriateness of the requested CT and MR imaging studies in the Philippine General Hospital outpatient department based on the American College of Radiology Appropriateness Criteria

@#<p style="text-align: justify;"><strong>Objective:</strong> To determine the rate of the appropriateness of the requested CT and MRI procedures in the Outpatient Department of a tertiary hospital in the Philippines from January to June 2018 using the American College of Radiology Appropriateness Criteria (ACR-AC).</p><p style="text-align: justify;"><strong>Methods:</strong> This retrospective research reviewed outpatient CT and MR imaging requests and cross-referenced with the corresponding ACR-AC guideline available for the written clinical diagnosis.</p><p style="text-align: justify;"><strong>Results:</strong> Four hundred thirty-six (436) (56%) of the 774 retrieved requests were CT scan studies, while the remaining 338 (44%) are MR imaging procedures. Cross-referencing with ACR-AC, the rate of appropriateness across all patients is high at 96.6%, with a 95% confidence interval of 95.0% and 97.6%. The rates were not significantly different between MRI and CT (p-value = 0.4502). Likewise, there was no significant difference in rates of appropriateness for the body parts abdomen, cranial, chest, and spine (p-value = 0.6502).</p><p style="text-align: justify;"><strong>Conclusion:</strong> Although the results were high, relative to the few available international studies, the importance and potential of the ACR-AC cannot be disregarded. The ACR-AC serves as a guide in selecting the appropriate imaging test given a clinical situation. This may equate to better patient management, considering all patient-related factors.</p><p style="text-align: justify;"><strong>Key Words:</strong> diagnostic imaging; reviews, appropriateness; practice guideline</p>

Development of a patient safety checklist for use during Fluoroscopic or Image-guided, minimally-invasive procedure in the Department of Radiology, Philippine General Hospital

Objective@#This study aimed to develop a patient-safety checklist for use during fluoroscopic- or image-guided minimally-invasive procedures in the Department of Radiology, Philippine General Hospital. @*Methodology@#A comparison of the Radiological Patient Safety System (RADPASS) and the Cardiovascular and Interventional Society of Europe (CIRSE) checklists was done. Together with the knowledge of the workflow and through observation of the different procedures in the department, a checklist was developed to suit the appropriate hospital setting. This developed checklist was tested in several procedures, and was evaluated and modified during trial testing. @*Result@#A patient safety checklist for minimally-invasive and fluoroscopic procedures in the Department of Radiology, Philippine General Hospital was developed through the analysis of the workflow of the department, and observation during the data gathering and trial testing phases. @*Conclusion@#This simple tool was developed to ensure that all the necessary details before a procedure have been addressed. It has been made as simple as possible, to make it user-friendly. The developed checklist is a step forward in promoting and ensuring the safety of patients undergoing fluoroscopic and minimally-invasive procedures in the Department of Radiology, PGH.

Nonresonant Transmission Line Probe for Sensitive Interferometric Electron Spin Resonance Detection.

Electron spin resonance (ESR) spectroscopy measures paramagnetic free radicals, or electron spins, in a variety of biological, chemical, and physical systems. Detection of diverse paramagnetic species is important in applications ranging from quantum computation to biomedical research. Countless efforts have been made to improve the sensitivity of ESR detection. However, the improvement comes at the cost of experimental accessibility. Thus, most ESR spectrometers are limited to specific sample geometries and compositions. Here, we present a nonresonant transmission line ESR probe (microstrip geometry) that effectively couples high frequency microwave magnetic field into a wide range of sample geometries and compositions. The nonresonant transmission line probe maintains detection sensitivity while increasing availability to a wider range of applications. The high frequency magnetic field homogeneity is greatly increased by positioning the sample between the microstrip signal line and the ground plane. Sample interfacing occurs via a universal sample holder which is compatible with both solid and liquid samples. The unavoidable loss in sensitivity due to the nonresonant nature of the transmission line probe (low Q) is recuperated by using a highly sensitive microwave interferometer-based detection circuit. The combination of our sensitive interferometer and nonresonant transmission line provides similar sensitivity to a commercially available ESR spectrometer equipped with a high-Q resonator. The nonresonant probe allows for transmission, reflection, or dual-mode detection (transmission and reflection), where the dual-mode results in a √2 signal enhancement.

Multimodality imaging approach in a patient with Klippel-Trenaunay syndrome.

Klippel-Trenaunay syndrome (KTS) is a rare congenital disorder presenting with asymmetric limb hypertrophy, cutaneous capillary malformations and lower extremity varicosities. We discuss a 27-year-old man born with varicosities on both lower extremities, which progressively enlarged. Physical examination showed a grossly enlarged right hand. There were multiple compressible varicosities, diffuse port-wine stains on the right leg and limb-length discrepancy on the left leg. CT angiogram and Doppler ultrasound revealed several venous varicosities. Ectatic veins in the right leg converge into the lateral marginal vein of Servelle, an embryonic vein, typically seen in KTS patients. KTS is diagnosed clinically and imaging plays a role in differentiating this from other disease entities that present similarly. Doppler ultrasound is the initial imaging of choice to characterise varicosities and to identify thrombosis and reflux. Plain radiographs confirm limb hypertrophy. MRI and CT angiograms are useful to evaluate vascular anomalies and its accompanying soft tissue changes.

Slow- and rapid-scan frequency-swept electrically detected magnetic resonance of MOSFETs with a non-resonant microwave probe within a semiconductor wafer-probing station.

We report on a novel electron paramagnetic resonance (EPR) technique that merges electrically detected magnetic resonance (EDMR) with a conventional semiconductor wafer probing station. This union, which we refer to as wafer-level EDMR (WL-EDMR), allows EDMR measurements to be performed on an unaltered, fully processed semiconductor wafer. Our measurements replace the conventional EPR microwave cavity or resonator with a very small non-resonant near-field microwave probe. Bipolar amplification effect, spin dependent charge pumping, and spatially resolved EDMR are demonstrated on various planar 4H-silicon carbide metal-oxide-semiconductor field-effect transistor (4H-SiC MOSFET) structures. 4H-SiC is a wide bandgap semiconductor and the leading polytype for high-temperature and high-power MOSFET applications. These measurements are made via both "rapid scan" frequency-swept EDMR and "slow scan" frequency swept EDMR. The elimination of the resonance cavity and incorporation with a wafer probing station greatly simplifies the EDMR detection scheme and offers promise for widespread EDMR adoption in semiconductor reliability laboratories.

Budget impact analysis of comprehensive genomic profiling in patients with advanced non-small cell lung cancer.

AIMS: Broad molecular profiling of patients with advanced non-small cell lung cancer (NSCLC) is strongly advised to optimize genomic matching with available targeted treatment options or investigational agents. Unlike conventional molecular diagnostic testing, or smaller hotspot panels, comprehensive genomic profiling (CGP) identifies genomic alterations across hundreds of clinically relevant cancer genes from a single tissue specimen. The present study sought to estimate the budget impact of increased use of CGP using a 324-gene panel (FoundationOne) vs non-CGP (represented by a mix of conventional molecular diagnostic testing and smaller NGS hotspot panels) and the number needed to test with CGP to gain 1 life year. MATERIALS AND METHODS: A decision analytic model was developed to assess the budget impact of increased CGP in advanced NSCLC from a US private payer perspective. Model inputs were based on published literature (epidemiology and treatment outcomes), real-world data (testing and rates, medical service costs), list prices for CGP and anti-cancer drugs, and assumptions for clinical trial participation. RESULTS: Among 2 million covered lives, 532 had advanced NSCLC; 266 underwent molecular diagnostic testing. An increase in CGP among those tested, from 2% to 10%, was associated with $0.02 per member per month budget impact, of which $0.013 was attributable to costs of prolonged drug treatment and survival and $0.005 to testing cost. Approximately 12 patients would need to be tested with CGP to add 1 life year. LIMITATIONS: The model incorporated certain assumptions to account for inputs with a limited evidence profile and simplify the possible post-CGP treatments. CONCLUSIONS: An increase in CGP utilization from 2% to 10% among patients with advanced NSCLC undergoing molecular diagnostic testing was associated with a modest budget impact, most of which was attributable to increased use of more effective treatments and prolonged survival.

Survival after abdominal aortic aneurysm repair is affected by socioeconomic status.

OBJECTIVE: The association between socioeconomic status (SES) and outcome after abdominal aortic aneurysm (AAA) repair is largely unknown. This study aimed to determine the influence of SES on postoperative survival after AAA repair. METHODS: Patients undergoing surgical treatment of AAA at a tertiary referral center between January 1993 and July 2013 were retrospectively collected. Thirty-day postoperative mortality and long-term mortality were documented through medical record review and the Michigan Social Security Death Index. SES was quantified using the neighborhood deprivation index (NDI), which is a standardized and reproducible index used in research that summarizes eight domains of socioeconomic deprivation and is based on census tracts derived from patients' individual addresses. The association between SES and survival was studied by univariable and multivariable Cox regression analysis. RESULTS: A total of 767 patients were included. The mean age was 73 years; 80% were male, 77% were white, and 20% were African American. There was no difference in SES of patients who underwent open vs endovascular repair of AAA (P = .489). The average NDI was -0.18 (minimum, -1.47; maximum, 2.35). After adjusting for the variables that were significant on univariable analysis (age, medical comorbidities, length of stay, and year of surgery), the association between NDI and long-term mortality was significant (P = .021; hazard ratio, 1.21 [1.05-1.37]). CONCLUSIONS: Long-term mortality after AAA repair is associated with SES. Further studies are required to assess which risk factors (behavioral, psychosocial) are responsible for this decreased long-term survival in low SES patients after AAA repair.

Inter-observer variation of the Alberta Stoke Program Early CT Score (ASPECTS) among radiologists in the Philippine General Hospital

@#<p style="text-align: justify;"><strong>Objective:</strong> To determine the inter-observer variation of ASPECTS among radiologists in the Philippine General Hospital (PGH), particularly between trainee radiologists and an expert reader.</p><p style="text-align: justify;"><strong>Methods:</strong> Thirty (30) cranial CT scan studies of clinically-diagnosed, non-hemorrhagic stroke patients were analyzed by 9 trainee radiologists (3 fellows, and 3 senior and 3 junior residents) and one expert reader. Data analysis involved determining the levels of agreement within and across groups, and against the expert reader.</p><p style="text-align: justify;"><strong>Results and Conclusion:</strong> There was moderate agreement (kappa = 0.60) between the junior residents and the expert reader, and substantial agreement between the senior residents and the expert reader (kappa = 0.70), as well as between the fellows and the expert reader (kappa = 0.63). Over-all, there was a substantial agreement between the trainee radiologists and the expert reader (kappa = 0.63). It can be concluded that the interpretation of trainee radiologists in PGH, particularly that of a senior resident or a fellow, is comparable with that of an expert reader, and can, thus, be useful in cases where an interpretation of a CT scan procedure in a clinically-diagnosed stroke patient is needed.</p>

All-Organic Textile Thermoelectrics with Carbon-Nanotube-Coated n-Type Yarns.

Thermoelectric textiles that are able to generate electricity from heat gradients may find use as power sources for a wide range of miniature wearable electronics. To realize such thermoelectric textiles, both p- and n-type yarns are needed. The realization of air-stable and flexible n-type yarns, i.e., conducting yarns where electrons are the majority charge carriers, presents a considerable challenge due to the scarcity of air-stable n-doped organic materials. Here, we realize such n-type yarns by coating commercial sewing threads with a nanocomposite of multiwalled carbon nanotubes (MWNTs) and poly(N-vinylpyrrolidone) (PVP). Our n-type yarns have a bulk conductivity of 1 S cm-1 and a Seebeck coefficient of -14 µV K-1, which is stable for several months at ambient conditions. We combine our coated n-type yarns with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) dyed silk yarns, constituting the p-type component, to realize a textile thermoelectric module with 38 n/p elements, which are capable of producing an open-circuit voltage of 143 mV when exposed to a temperature gradient of 116 °C and a maximum power output of 7.1 nW at a temperature gradient of 80 °C.

Real-world utilization of molecular diagnostic testing and matched drug therapies in the treatment of metastatic cancers.

AIMS: To assess the frequency of biopsies and molecular diagnostic testing (human DNA/RNA analysis), anti-cancer drug use (genomically-matched targeted therapy [GMTT], unmatched targeted therapy [UTT], endocrine therapy [ET], and chemotherapy [CT]), and medical service costs among adults with metastatic cancer. METHODS: Adults diagnosed with metastatic breast, non-small cell lung (NSCLC), colorectal, head and neck, ovarian, and uterine cancer (2010Q1-2015Q1) were identified in the OptumHealth Care Solutions claims database and followed from first metastatic diagnosis for ≥1 month and until the end of data availability. Utilization was assessed for each cancer cohort (all and patients aged ≥65 years); per-patient-per-month (PPPM) medical service costs were assessed for all patients. Testing frequency estimates were applied to Surveillance, Epidemiology, and End Results Program data to estimate the number of untested patients (2010-2014). RESULTS: Patients with metastatic cancer (n = 8,193; breast [n = 3,414], NSCLC [n = 2,231], colorectal [n = 1,611], head and neck [n = 511], ovarian [n = 275], and uterine [n = 151]) were 63 years old (mean), with 11.1-22.2 months of observation. Biopsy and molecular diagnostic testing frequencies ranged from 7% (uterine) to 73% (ovarian), and from 34% (head and neck) to 52% (breast), respectively. Few were treated with GMTT (breast, 11%; NSCLC, 9%; colorectal, 6%). Treatment with UTT ranged from 0.7% (uterine) to 21% (colorectal). Biopsy, diagnostic testing, and anti-cancer drug therapy were less frequent for those ≥65 years. Medical service costs (PPPM, mean) ranged from $6,618 (head and neck) to $9,940 (ovarian). The estimated number of untested new patients with metastatic cancer was 636,369 (all) and 341,397 (≥65). LIMITATIONS: In addition to the limitations of claims analyses, diagnostic testing frequency may be under-estimated if patients underwent testing prior to study inclusion. CONCLUSIONS: The low frequency of molecular diagnostic testing suggests there are opportunities to better inform management of patients with advanced cancer, particularly decisions to treat with GMTT.

Estimated Cost of Anticancer Therapy Directed by Comprehensive Genomic Profiling in a Single-Center Study.

PURPOSE: Comprehensive genomic profiling (CGP) detects several classes of genomic alterations across numerous genes simultaneously and can match more patients with genomically targeted therapies than conventional molecular profiling. The current study estimated the costs of anticancer drugs and overall survival (OS) for patients who were treated with matched and unmatched therapy. METHODS: Costs were estimated for patients with complete data (188 of 500 patients) from a prospective, nonrandomized study of patients with diverse refractory cancers who underwent CGP and were treated with matched or unmatched therapy. We assessed mean time to treatment failure (TTF) and mean observed OS. Patient-specific drug and administration costs were imputed for the first regimen after CGP on the basis of drug classes, unit costs, and time on treatment. RESULTS: Patients on matched (n = 122) versus unmatched (n = 66) therapy had longer mean TTF (+1.5 months) and observed OS (+2.4 months) and higher drug costs (+$38,065; all P < .01). Increased drug costs were largely attributable to the longer duration of therapy associated with extended TTF (66.3%) rather than higher monthly drug costs (33.7%). Incremental increases in TTF (+1.9 months v +1.2 months) and observed OS (+2.5 months v +2.1 months) between matched and unmatched therapies were larger for those who underwent CGP in earlier- versus later-line therapy. Incremental increases in drug costs between matched and unmatched therapies were lower for earlier- compared with later-line therapy (+$27,000 v +$43,000, respectively). CONCLUSION: Matched therapy was associated with longer TTF, increased OS, and manageable incremental cost increases compared with unmatched therapy. Most of these increased costs were a result of the longer duration of therapy rather than higher monthly drug costs. The benefits of matching were numerically greater in earlier versus later lines of therapy, which is consistent with the value of early use of CGP.

Ferroelectricity in Polar Polymer-based FETs: A Hysteresis Analysis.

There is an increasing number of reports on polar polymer-based Ferroelectric Field Effect Transistors (FeFETs), where the hysteresis of the drain current - gate voltage (Id-Vg) curve is investigated as the result of the ferroelectric polarization effect. However, separating ferroelectric effect from many of the factors (such as charge injection/trapping and the presence of mobile ions in the polymer) that confound interpretation is still confusing and controversial. This work presents a methodology to reliably identify the confounding factors which obscure the polarization effect in FeFETs. Careful observation of the Id-Vg curves, as well as monitoring the Id-Vg hysteresis and flat band voltage shift as a function of temperature and sweep frequency identifies the dominant mechanism. This methodology is demonstrated using 15-nm thick high glass transition temperature polar polymer-based FeFETs. In these devices, room temperature hysteresis is largely a consequence of charge trapping and mobile ions, while ferroelectric polarization is observed at elevated temperatures. This methodology can be used to unambiguously prove the effect of ferroelectric polarization in FeFETs.

Wafer-Level Electrically Detected Magnetic Resonance: Magnetic Resonance in a Probing Station.

We report on a novel semiconductor reliability technique that incorporates an electrically detected magnetic resonance (EDMR) spectrometer within a conventional semiconductor wafer probing station. EDMR is an ultrasensitive electron paramagnetic resonance technique with the capability to provide detailed physical and chemical information about reliability limiting defects in semiconductor devices. EDMR measurements have generally required a complex apparatus, not typically found in solid-state electronics laboratories. The union of a semiconductor probing station with EDMR allows powerful analytical measurements to be performed within individual devices at the wafer level. Our novel approach replaces the standard magnetic resonance microwave cavity or resonator with a small non- resonant near field microwave probe. Using this new approach we have demonstrated bipolar amplification effect and spin dependent charge pumping in various SiC based MOSFET structures. Although our studies have been limited to SiC based devices, the approach will be widely applicable to other types of MOSFETs, bipolar junction transistors, and various memory devices. The replacement of the resonance cavity with the very small non- resonant microwave probe greatly simplifies the EDMR detection scheme and allows for the incorporation of this powerful tool with a wafer probing station. We believe this scheme offers great promise for widespread utilization of EDMR in semiconductor reliability laboratories.

Impact of RRAM Read Fluctuations on the Program-Verify Approach.

The stochastic nature of the conductive filaments in oxide-based resistive memory (RRAM) represents a sizeable impediment to commercialization. As such, program-verify methodologies are highly alluring. However, it was recently shown that program-verify methods are unworkable due to strong resistance state relaxation after SET/RESET programming. In this paper, we demonstrate that resistance state relaxation is not the main culprit. Instead, it is fluctuation-induced false-reading (triggering) that defeats the program-verify method, producing a large distribution tail immediately after programming. The fluctuation impact on the verify mechanism has serious implications on the overall write/erase speed of RRAM.

Machine-Washable PEDOT:PSS Dyed Silk Yarns for Electronic Textiles.

Durable, electrically conducting yarns are a critical component of electronic textiles (e-textiles). Here, such yarns with exceptional wear and wash resistance are realized through dyeing silk from the silkworm Bombyx mori with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. A high Young's modulus of approximately 2 GPa combined with a robust and scalable dyeing process results in up to 40 m long yarns that maintain their bulk electrical conductivity of approximately 14 S cm-1 when experiencing repeated bending stress as well as mechanical wear during sewing. Moreover, a high degree of ambient stability is paired with the ability to withstand both machine washing and dry cleaning. For the potential use for e-textile applications to be illustrated, an in-plane thermoelectric module that comprises 26 p-type legs is demonstrated by embroidery of dyed silk yarns onto a piece of felted wool fabric.

Observation of Strong Reflection of Electron Waves Exiting a Ballistic Channel at Low Energy.

Wave scattering by a potential step is a ubiquitous concept. Thus, it is surprising that theoretical treatments of ballistic transport in nanoscale devices, from quantum point contacts to ballistic transistors, assume no reflection even when the potential step is encountered upon exiting the device. Experiments so far seem to support this even if it is not clear why. Here we report clear evidence of coherent reflection when electron wave exits the channel of a nanoscale transistor and when the electron energy is low. The observed behavior is well described by a simple rectangular potential barrier model which the Schrodinger's equation can be solved exactly. We can explain why reflection is not observed in most situations but cannot be ignored in some important situations. Our experiment also represents a direct measurement of electron injection velocity - a critical quantity in nanoscale transistors that is widely considered not measurable.