Direct Writing of Flexible Electronics through Room Temperature Liquid Metal Ink

Background

Conventional approaches of making a flexible circuit are generally complex, environment unfriendly, time and energy consuming, and thus expensive. Here, we describe for the first time the method of using high-performance GaIn₁₀-based electrical ink, a significantly neglected room temperature liquid metal, as both electrical conductors and interconnects, for directly writing flexible electronics via a rather easy going and cost effective way.

Methods

The new generation electric ink was made and its wettability with various materials was modified to be easily written on a group of either soft or rigid substrates such as epoxy resin board, glass, plastic, silica gel, paper, cotton, textiles, cloth and fiber etc. Conceptual experiments were performed to demonstrate and evaluate the capability of directly writing the electrical circuits via the invented metal ink. Mechanisms involved were interpreted through a series of fundamental measurements.

Results

The electrical resistivity of the fluid like GaIn₁₀-based material was measured as 34.5 µΩ·cm at 297 K by four point probe method and increased with addition of the oxygen quantity, which indicates it as an excellent metal ink. The conductive line can be written with features that are approximately 10 µm thick. Several functional devices such as a light emitting diode (LED) array showing designed lighting patterns and electrical fan were made to work by directly writing the liquid metal on the specific flexible substrates. And satisfactory performances were obtained.

Conclusions

The present method opens the way to directly and quickly writing flexible electronics which can be as simple as signing a name or drawing a picture on the paper. The unique merit of the GaIn₁₀-based liquid metal ink lies in its low melting temperature, well controlled wettability, high electrical conductivity and good biocompability. The new electronics writing strategy and basic principle has generalized purpose and can be extended to more industrial areas, even daily life.     

Directly Writing Resistor,Inductor and Capacitor to Composite Functional Circuits: A Super-Simple Way for Alternative Electronics

Background

The current strategies for making electronic devices are generally time, water, material and energy consuming. Here, the direct writing of composite functional circuits through comprehensive use of GaIn₁₀-based liquid metal inks and matching material is proposed and investigated, which is a rather easy going and cost effective electronics fabrication way compared with the conventional approaches.

Methods

Owing to its excellent adhesion and electrical properties, the liquid metal ink was demonstrated as a generalist in directly making various basic electronic components such as planar resistor, inductor and capacitor or their combination and thus composing circuits with expected electrical functions. For a precise control of the geometric sizes of the writing, a mask with a designed pattern was employed and demonstrated. Mechanisms for justifying the chemical components of the inks and the magnitudes of the target electronic elements so as to compose various practical circuits were disclosed.

Results

Fundamental tests on the electrical components including capacitor and inductor directly written on paper with working time up to 48 h and elevated temperature demonstrated their good stability and potential widespread adaptability especially when used in some high frequency circuits. As the first proof-of-concept experiment, a typical functional oscillating circuit including an integrated chip of 74HC04 with a supply voltage of 5 V, a capacitor of 10 nF and two resistors of 5 kΩ and 1 kΩ respectively was directly composed on paper through integrating specific electrical elements together, which presented an oscillation frequency of 8.8 kHz.

Conclusions

The present method significantly extends the roles of the metal ink in recent works serving as only a single electrical conductor or interconnecting wires. It opens the way for directly writing out complex functional circuits or devices on different substrates. Such circuit composition strategy has generalized purpose and can be extended to more areas, even daily pervasive electronics.     

Non-Invasive Drosophila ECG Recording by Using Eutectic Gallium-Indium Alloy Electrode: A Feasible Tool for Future Research on the Molecular Mechanisms Involved in Cardiac Arrhythmia

Background

Drosophila heart tube is a feasible model for cardiac physiological research. However, obtaining Drosophila electrocardiograms (ECGs) is difficult, due to the weak signals and limited contact area to apply electrodes. This paper presents a non-invasive Gallium-Indium (GaIn) based recording system for Drosophila ECG measurement, providing the heart rate and heartbeat features to be observed. This novel, high-signal-quality system prolongs the recording time of insect ECGs, and provides a feasible platform for research on the molecular mechanisms involved in cardiovascular diseases.

Methods

In this study, two types of electrode, tungsten needle probes and GaIn electrodes, were used respectively to noiselessly conduct invasive and noninvasive ECG recordings of Drosophila. To further analyze electrode properties, circuit models were established and simulated. By using electromagnetic shielded heart signal acquiring system, consisted of analog amplification and digital filtering, the ECG signals of three phenotypes that have different heart functions were recorded without dissection.

Results and Discussion

The ECG waveforms of different phenotypes of Drosophila recorded invasively and repeatedly with n value (n>5) performed obvious difference in heart rate. In long period ECG recordings, non-invasive method implemented by GaIn electrodes acts relatively stable in both amplitude and period. To analyze GaIn electrode, the correctness of GaIn electrode model established by this paper was validated, presenting accuracy, stability, and reliability.

Conclusions

Noninvasive ECG recording by GaIn electrodes was presented for recording Drosophila pupae ECG signals within a limited contact area and signal strength. Thus, the observation of ECG changes in normal and SERCA-depleted Drosophila over an extended period is feasible. This method prolongs insect survival time while conserving major ECG features, and provides a platform for electrophysiological signal research on the molecular mechanism involved in cardiac arrhythmia, as well as research related to drug screening and development.     

Comparing Cutaneous Research Funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases with 2010 Global Burden of Disease Results

Importance

Disease burden data helps guide research prioritization.

Objective

To determine the extent to which grants issued by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) reflect disease burden, measured by disability-adjusted life years (DALYs) from Global Burden of Disease (GBD) 2010 project.

Design

Two investigators independently assessed 15 skin conditions studied by GBD 2010 in the NIAMS database for grants issued in 2013. The 15 skin diseases were matched to their respective DALYs from GBD 2010.

Setting

The United States NIAMS database and GBD 2010 skin condition disability data.

Main Outcome(s) and Measure(s)

Relationship of NIAMS grant database topic funding with percent total GBD 2010 DALY and DALY rank for 15 skin conditions.

Results

During fiscal year 2013, 1,443 NIAMS grants were issued at a total value of $424 million. Of these grants, 17.7% covered skin topics. Of the total skin disease funding, 82% (91 grants) were categorized as “general cutaneous research.” Psoriasis, leprosy, and “other skin and subcutaneous diseases” (ie; immunobullous disorders, vitiligo, and hidradenitis suppurativa) were over-represented when funding was compared with disability. Conversely, cellulitis, decubitus ulcer, urticaria, acne vulgaris, viral skin diseases, fungal skin diseases, scabies, and melanoma were under-represented. Conditions for which disability and funding appeared well-matched were dermatitis, squamous and basal cell carcinoma, pruritus, bacterial skin diseases, and alopecia areata.

Conclusions and Relevance

Degree of representation in NIAMS is partly correlated with DALY metrics. Grant funding was well-matched with disability metrics for five of the 15 studied skin diseases, while two skin diseases were over-represented and seven were under-represented. Global burden estimates provide increasingly transparent and important information for investigating and prioritizing national research funding allocations.     

Coryphoid Palm Leaf Fossils from the Maastrichtian–Danian of Central India with Remarks on Phytogeography of the Coryphoideae (Arecaceae)

Premise of research

A large number of fossil coryphoid palm wood and fruits have been reported from the Deccan Intertrappean beds of India. We document the oldest well-preserved and very rare costapalmate palm leaves and inflorescence like structures from the same horizon.

Methodology

A number of specimens were collected from Maastrichtian–Danian sediments of the Deccan Intertrappean beds, Ghughua, near Umaria, Dindori District, Madhya Pradesh, India. The specimens are compared with modern and fossil taxa of the family Arecaceae.

Pivotal results

Sabalites dindoriensis sp. nov. is described based on fossil leaf specimens including basal to apical parts. These are the oldest coryphoid fossil palm leaves from India as well as, at the time of deposition, from the Gondwana- derived continents.

Conclusions

The fossil record of coryphoid palm leaves presented here and reported from the Eurasian localities suggests that this is the oldest record of coryphoid palm leaves from India and also from the Gondwana- derived continents suggesting that the coryphoid palms were well established and wide spread on both northern and southern hemispheres by the Maastrichtian–Danian. The coryphoid palms probably dispersed into India from Europe via Africa during the latest Cretaceous long before the Indian Plate collided with the Eurasian Plate.     

Cardiac involvement in Caucasian patients with pulmonary sarcoidosis

Background

Cardiac sarcoidosis (CS) is a potentially life-threatening condition. At present, there is no consensus with regard to the optimal non-invasive clinical evaluation and diagnostic procedures of cardiac involvement in patients with sarcoidosis. The aim of this study in a large homogenous Scandinavian sarcoidosis cohort was therefore to identify risk factors of cardiac involvement in patients with sarcoidosis, and the value of initial routine investigation with ECG and cardiac related symptoms in screening for CS.

Methods

In this retrospective study a cohort of 1017 Caucasian patients with sarcoidosis were included. They were all screened with ECG at disease onset and investigated for CS according to clinical routine.

Results

An abnormal ECG was recorded in 166 (16.3%) of the 1017 patients and CS was later diagnosed in 22 (13.2%) of them, compared to in one (0.1%) of the 851 sarcoidosis patients with a normal ECG (p < 0.0001). The risk for CS was higher in patients with a pathologic ECG combined with cardiac related symptoms (11/40) (27.5%) compared to those with pathologic ECG changes without symptoms (11/126) (8.7%) (p < 0.01). Furthermore, patients with Löfgren’s syndrome had a reduced risk for CS compared to those without (p < 0.05) the syndrome.

Conclusions

This study on an unusually large and homogenous sarcoidosis population demonstrate the importance of an abnormal ECG and cardiac related symptoms at disease onset as powerful predictors of a later diagnosis of cardiac sarcoidosis. In contrast, CS is very rare in subjects without symptoms and with a normal ECG. This knowledge is of importance, and may be used in a clinical algorithm, in identifying patients that should be followed and investigated extensively for the presence of CS.     

Abnormal T2-STIR Magnetic Resonance in Hypertrophic Cardiomyopathy: A Marker of Advanced Disease and Electrical Myocardial Instability

Background

Myocardial hyperintensity on T2-weighted short-tau inversion recovery (STIR) (HyT2) cardiac magnetic resonance (CMR) images has been demonstrated in patients with hypertrophic cardiomyopathy (HCM) and is considered a sign of acute damage. The aim of the current study was to evaluate the relationship between HyT2 and both a) markers of ventricular electrical instability and b) clinical and CMR parameters.

Methods

Sixty-five patients underwent a thorough clinical examination, consisting of 24-h ECG recording and CMR examination including functional evaluation, T2-STIR images and late gadolinium enhancement (LGE).

Results

HyT2 was detected in 27 patients (42%), and subjects with HyT2 showed a greater left ventricle (LV) mass index (p<0.001), lower LV ejection fraction (p = 0.05) and greater extent of LGE (p<0.001) compared to those without HyT2. Twenty-two subjects (34%) presented non-sustained ventricular tachycardia (NSVT) on the 24-h ECG recording, 21 (95%) of whom exhibited HyT2. Based on the logistic regression analysis, HyT2 (odds ratio [OR]: 165, 95% CI 11–2455, p<0.001) and LGE extent (1.1, 1.0–1.3, p<0.001) served as independent predictors of NSVT, while the presence of LGE was not associated with NSVT occurrence (p = 0.49). The presence of HyT2 was associated with lower heart rate variability (p = 0.006) and a higher number of arrhythmic risk factors (p<0.001).

Conclusions

In HCM patients, HyT2 upon CMR examination is associated with more advanced disease and increased arrhythmic burden.     

Rapid amygdala gamma oscillations in response to eye gaze

Background

The eye gaze of other individuals conveys important social information and can trigger multiple psychological activities; some of which, such as emotional reactions and attention orienting, occur very rapidly. Although some neuroscientific evidence has suggested that the amygdala may be involved in such rapid gaze processing, no evidence has been reported concerning the speed at which the amygdala responds to eye gaze.

Methodology/Principal Findings

To investigate this issue, we recorded electrical activity within the amygdala of six subjects using intracranial electrodes. Subjects observed images of eyes and mosaics pointing in averted and straight directions. The amygdala showed higher gamma-band oscillations for eye gaze than for mosaics, which peaked at 200 ms regardless of the direction of the gaze.

Conclusion

These results indicate that the human amygdala rapidly processes eye gaze.     

ECG Marker of Adverse Electrical Remodeling Post-Myocardial Infarction Predicts Outcomes in MADIT II Study

Background

Post-myocardial infarction (MI) structural remodeling is characterized by left ventricular dilatation, fibrosis, and hypertrophy of the non-infarcted myocardium.

Objective

The goal of our study was to quantify post-MI electrical remodeling by measuring the sum absolute QRST integral (SAI QRST). We hypothesized that adverse electrical remodeling predicts outcomes in MADIT II study participants.

Methods

Baseline orthogonal ECGs of 750 MADIT II study participants (448 [59.7%] ICD arm) were analyzed. SAI QRST was measured as the arithmetic sum of absolute QRST integrals over all three orthogonal ECG leads. The primary endpoint was defined as sudden cardiac death (SCD) or sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) with appropriate ICD therapies. All-cause mortality served as a secondary endpoint.

Results

Adverse electrical remodeling in post-MI patients was characterized by wide QRS, increased magnitudes of spatial QRS and T vectors, J-point deviation, and QTc prolongation. In multivariable Cox regression analysis after adjustment for age, QRS duration, atrial fibrillation, New York Heart Association heart failure class and blood urea nitrogen, SAI QRST predicted SCD/VT/VF (HR 1.33 per 100 mV*ms (95%CI 1.11–1.59); P = 0.002), and all-cause death (HR 1.27 per 100 mV*ms (95%CI 1.03–1.55), P = 0.022) in both arms. No interaction with therapy arm and bundle branch block (BBB) status was found.

Conclusions

In MADIT II patients, increased SAI QRST is associated with increased risk of sustained VT/VF with appropriate ICD therapies and all-cause death in both ICD and in conventional medical therapy arms, and in patients with and without BBB. Further studies of SAI QRST are warranted.     

A Novel Model of Human Skin Pressure Ulcers in Mice

Introduction

Pressure ulcers are a prevalent health problem in today''s society. The shortage of suitable animal models limits our understanding and our ability to develop new therapies. This study aims to report on the development of a novel and reproducible human skin pressure ulcer model in mice.

Material and Methods

Male non-obese, diabetic, severe combined immunodeficiency mice (n = 22) were engrafted with human skin. A full-thickness skin graft was placed onto 4×3 cm wounds created on the dorsal skin of the mice. Two groups with permanent grafts were studied after 60 days. The control group (n = 6) was focused on the process of engraftment. Evaluations were conducted with photographic assessment, histological analysis and fluorescence in situ hybridization (FISH) techniques. The pressure ulcer group (n = 12) was created using a compression device. A pressure of 150 mmHg for 8 h, with a total of three cycles of compression-release was exerted. Evaluations were conducted with photographic assessment and histological analysis.

Results

Skin grafts in the control group took successfully, as shown by visual assessment, FISH techniques and histological analysis. Pressure ulcers in the second group showed full-thickness skin loss with damage and necrosis of all the epidermal and dermal layers (ulcer stage III) in all cases. Complete repair occurred after 40 days.

Conclusions

An inexpensive, reproducible human skin pressure ulcer model has been developed. This novel model will facilitate the development of new clinically relevant therapeutic strategies that can be tested directly on human skin.     

Effect of Surfactant and Partial Liquid Ventilation Treatment on Gas Exchange and Lung Mechanics in Immature Lambs: Influence of Gestational Age

Objectives

Surfactant (SF) and partial liquid ventilation (PLV) improve gas exchange and lung mechanics in neonatal RDS. However, variations in the effects of SF and PLV with degree of lung immaturity have not been thoroughly explored.

Setting

Experimental Neonatal Respiratory Physiology Research Unit, Cruces University Hospital.

Design

Prospective, randomized study using sealed envelopes.

Subjects

36 preterm lambs were exposed (at 125 or 133-days of gestational age) by laparotomy and intubated. Catheters were placed in the jugular vein and carotid artery.

Interventions

All the lambs were assigned to one of three subgroups given: 20 mL/Kg perfluorocarbon and managed with partial liquid ventilation (PLV), surfactant (Curosurf®, 200 mg/kg) or (3) no pulmonary treatment (Controls) for 3 h.

Measurements and Main Results

Cardiovascular parameters, blood gases and pulmonary mechanics were measured. In 125-day gestation lambs, SF treatment partially improved gas exchange and lung mechanics, while PLV produced significant rapid improvements in these parameters. In 133-day lambs, treatments with SF or PLV achieved similarly good responses. Neither surfactant nor PLV significantly affected the cardiovascular parameters.

Conclusion

SF therapy response was more effective in the older gestational age group whereas the effectiveness of PLV therapy was not gestational age dependent.     

A Technique for Performing Electrical Impedance Myography in the Mouse Hind Limb: Data in Normal and ALS SOD1 G93A Animals

Objective

To test a method for performing electrical impedance myography (EIM) in the mouse hind limb for the assessment of disease status in neuromuscular disease models.

Methods

An impedance measuring device consisting of a frame with electrodes embedded within an acrylic head was developed. The head was rotatable such that data longitudinal and transverse to the major muscle fiber direction could be obtained. EIM measurements were made with this device on 16 healthy mice and 14 amyotrophic lateral sclerosis (ALS) animals. Repeatability was assessed in both groups.

Results

The technique was easy to perform and provided good repeatability in both healthy and ALS animals, with intra-session repeatability (mean ± SEM) of 5% ±1% and 12% ±2%, respectively. Significant differences between healthy and ALS animals were also identified (e.g., longitudinal mean 50 kHz phase was 18±0.6° for the healthy animals and 14±1.0° for the ALS animals, p = 0.0025).

Conclusions

With this simple device, the EIM data obtained is highly repeatable and can differentiate healthy from ALS animals.

Significance

EIM can now be applied to mouse models of neuromuscular disease to assess disease status and the effects of therapy.     

Analysis of physiological signals for recognition of boredom,pain, and surprise emotions

Background

The aim of the study was to examine the differences of boredom, pain, and surprise. In addition to that, it was conducted to propose approaches for emotion recognition based on physiological signals.

Methods

Three emotions, boredom, pain, and surprise, are induced through the presentation of emotional stimuli and electrocardiography (ECG), electrodermal activity (EDA), skin temperature (SKT), and photoplethysmography (PPG) as physiological signals are measured to collect a dataset from 217 participants when experiencing the emotions. Twenty-seven physiological features are extracted from the signals to classify the three emotions. The discriminant function analysis (DFA) as a statistical method, and five machine learning algorithms (linear discriminant analysis (LDA), classification and regression trees (CART), self-organizing map (SOM), Naïve Bayes algorithm, and support vector machine (SVM)) are used for classifying the emotions.

Results

The result shows that the difference of physiological responses among emotions is significant in heart rate (HR), skin conductance level (SCL), skin conductance response (SCR), mean skin temperature (meanSKT), blood volume pulse (BVP), and pulse transit time (PTT), and the highest recognition accuracy of 84.7 % is obtained by using DFA.

Conclusions

This study demonstrates the differences of boredom, pain, and surprise and the best emotion recognizer for the classification of the three emotions by using physiological signals.     

Chronic Electrical Stimulation with a Suprachoroidal Retinal Prosthesis: A Preclinical Safety and Efficacy Study

Purpose

To assess the safety and efficacy of chronic electrical stimulation of the retina with a suprachoroidal visual prosthesis.

Methods

Seven normally-sighted feline subjects were implanted for 96–143 days with a suprachoroidal electrode array and six were chronically stimulated for 70–105 days at levels that activated the visual cortex. Charge balanced, biphasic, current pulses were delivered to platinum electrodes in a monopolar stimulation mode. Retinal integrity/function and the mechanical stability of the implant were assessed monthly using electroretinography (ERG), optical coherence tomography (OCT) and fundus photography. Electrode impedances were measured weekly and electrically-evoked visual cortex potentials (eEVCPs) were measured monthly to verify that chronic stimuli were suprathreshold. At the end of the chronic stimulation period, thresholds were confirmed with multi-unit recordings from the visual cortex. Randomized, blinded histological assessments were performed by two pathologists to compare the stimulated and non-stimulated retina and adjacent tissue.

Results

All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. After an initial post-operative settling period, electrode arrays were mechanically stable. Mean electrode impedances were stable between 11–15 kΩ during the implantation period. Visually-evoked ERGs & OCT were normal, and mean eEVCP thresholds did not substantially differ over time. In 81 of 84 electrode-adjacent tissue samples examined, there were no discernible histopathological differences between stimulated and unstimulated tissue. In the remaining three tissue samples there were minor focal fibroblastic and acute inflammatory responses.

Conclusions

Chronic suprathreshold electrical stimulation of the retina using a suprachoroidal electrode array evoked a minimal tissue response and no adverse clinical or histological findings. Moreover, thresholds and electrode impedance remained stable for stimulation durations of up to 15 weeks. This study has demonstrated the safety and efficacy of suprachoroidal stimulation with charge balanced stimulus currents.     

Cost-Effectiveness of a Community Pharmacist-Led Sleep Apnea Screening Program – A Markov Model

Background

Despite the high prevalence and major public health ramifications, obstructive sleep apnea syndrome (OSAS) remains underdiagnosed. In many developed countries, because community pharmacists (CP) are easily accessible, they have been developing additional clinical services that integrate the services of and collaborate with other healthcare providers (general practitioners (GPs), nurses, etc.). Alternative strategies for primary care screening programs for OSAS involving the CP are discussed.

Objective

To estimate the quality of life, costs, and cost-effectiveness of three screening strategies among patients who are at risk of having moderate to severe OSAS in primary care.

Design

Markov decision model.

Data Sources

Published data.

Target Population

Hypothetical cohort of 50-year-old male patients with symptoms highly evocative of OSAS.

Time Horizon

The 5 years after initial evaluation for OSAS.

Perspective

Societal.

Interventions

Screening strategy with CP (CP-GP collaboration), screening strategy without CP (GP alone) and no screening.

Outcomes measures

Quality of life, survival and costs for each screening strategy.

Results of base-case analysis

Under almost all modeled conditions, the involvement of CPs in OSAS screening was cost effective. The maximal incremental cost for “screening strategy with CP” was about 455€ per QALY gained.

Results of sensitivity analysis

Our results were robust but primarily sensitive to the treatment costs by continuous positive airway pressure, and the costs of untreated OSAS. The probabilistic sensitivity analysis showed that the “screening strategy with CP” was dominant in 80% of cases. It was more effective and less costly in 47% of cases, and within the cost-effective range (maximum incremental cost effectiveness ratio at €6186.67/QALY) in 33% of cases.

Conclusions

CP involvement in OSAS screening is a cost-effective strategy. This proposal is consistent with the trend in Europe and the United States to extend the practices and responsibilities of the pharmacist in primary care.     

Effects of TRAP-1-Like Protein (TLP) Gene on Collagen Synthesis Induced by TGF-β/Smad Signaling in Human Dermal Fibroblasts

Background

Hypertrophic scars are pathologic proliferations of the dermal skin layer resulting from excessive collagen deposition during the healing process of cutaneous wounds. Current research suggests that the TGF-β/Smad signaling pathway is closely associated with normal scar and hypertrophic scar formation. TRAP-1-like protein (TLP), a cytoplasmic protein, has been reported to efficiently regulate Smad2- and Smad3-dependent signal expression in the TGF-β pathway. The relationship between TLP and Type I/III collagen (Col I/III) synthesis explored in the present study provides an effective target for wound healing and gene therapy of hypertrophic scarring.

Objective

To investigate the effects of TLP on collagen synthesis in human dermal fibroblasts.

Methods

Lentiviral vectors encoding TLP was constructed to transfect fibroblasts derived from normal human skin. The expression of Col I/III and phosphorylation of Smad2 and Smad3 in fibroblasts were examined after TLP treatment. In addition, the comparison of TLP expression in normal skin tissues and in hypertrophic scar tissues was performed, and the effect of TLP on cell viability was analyzed by MTT assay.

Results

TLP expression in hypertrophic scar tissue was markedly higher than in normal skin tissue. The Real Time PCR and Western blot test results both revealed that the synthesis of Col I/III was positively correlated with the expression of TLP. TLP also facilitate Smad2 phosphorylation while, conversely, inhibiting Smad3 phosphorylation. TLP may play a cooperative role, along with the cytokine TGF-β1, in improving the overall cell viability of skin fibroblasts.

Conclusions

TLP likely acts as a molecular modulator capable of altering the balance of Smad3- and Smad2-dependent signaling through regulation of phosphorylation, thus facilitating collagen synthesis in fibroblasts. Based on genetic variation in TLP levels in different tissues, these results suggest that TLP plays a key role in the process of TGF-β1/Smad3 signaling that contributes to wound healing and genesis of pathologic scars.     

Computer-Aided Diagnosis of Skin Lesions Using Conventional Digital Photography: A Reliability and Feasibility Study

Background

Computer-aided diagnosis (CADx) software that provides a second opinion has been widely used to assist physicians with various tasks. In dermatology, however, CADx has been mostly limited to melanoma or melanocytic skin cancer diagnosis. The frequency of non-melanocytic skin cancers and the accessibility of regular digital macrographs have raised interest in developing CADx for broader applications.

Objectives

To investigate the feasibility of using CADx to diagnose both melanocytic and non-melanocytic skin lesions based on conventional digital photographic images.

Methods

This study was approved by an institutional review board, and the requirement to obtain informed consent was waived. In total, 769 conventional photographs of melanocytic and non-melanocytic skin lesions were retrospectively reviewed and used to develop a CADx system. Conventional and new color-related image features were developed to classify the lesions as benign or malignant using support vector machines (SVMs). The performance of CADx was compared with that of dermatologists.

Results

The clinicians'' overall sensitivity, specificity, and accuracy were 83.33%, 85.88%, and 85.31%, respectively. New color correlation and principal component analysis (PCA) features improved the classification ability of the baseline CADx (p = 0.001). The estimated area under the receiver operating characteristic (ROC) curve (Az) of the proposed CADx system was 0.949, with a sensitivity and specificity of 85.63% and 87.65%, respectively, and a maximum accuracy of 90.64%.

Conclusions

We have developed an effective CADx system to classify both melanocytic and non-melanocytic skin lesions using conventional digital macrographs. The system''s performance was similar to that of dermatologists at our institute. Through improved feature extraction and SVM analysis, we found that conventional digital macrographs were feasible for providing useful information for CADx applications. The new color-related features significantly improved CADx applications for skin cancer.     

Electrocardiographic Abnormalities in Trypanosoma cruzi Seropositive and Seronegative Former Blood Donors

Background

Blood donor screening leads to large numbers of new diagnoses of Trypanosoma cruzi infection, with most donors in the asymptomatic chronic indeterminate form. Information on electrocardiogram (ECG) findings in infected blood donors is lacking and may help in counseling and recognizing those with more severe disease.

Objectives

To assess the frequency of ECG abnormalities in T.cruzi seropositive relative to seronegative blood donors, and to recognize ECG abnormalities associated with left ventricular dysfunction.

Methods

The study retrospectively enrolled 499 seropositive blood donors in São Paulo and Montes Claros, Brazil, and 483 seronegative control donors matched by site, gender, age, and year of blood donation. All subjects underwent a health clinical evaluation, ECG, and echocardiogram (Echo). ECG and Echo were reviewed blindly by centralized reading centers. Left ventricular (LV) dysfunction was defined as LV ejection fraction (EF)<0.50%.

Results

Right bundle branch block and left anterior fascicular block, isolated or in association, were more frequently found in seropositive cases (p<0.0001). Both QRS and QTc duration were associated with LVEF values (correlation coefficients −0.159,p<0.0003, and −0.142,p = 0.002) and showed a moderate accuracy in the detection of reduced LVEF (area under the ROC curve: 0.778 and 0.790, both p<0.0001). Several ECG abnormalities were more commonly found in seropositive donors with depressed LVEF, including rhythm disorders (frequent supraventricular ectopic beats, atrial fibrillation or flutter and pacemaker), intraventricular blocks (right bundle branch block and left anterior fascicular block) and ischemic abnormalities (possible old myocardial infarction and major and minor ST abnormalities). ECG was sensitive (92%) for recognition of seropositive donors with depressed LVEF and had a high negative predictive value (99%) for ruling out LV dysfunction.

Conclusions

ECG abnormalities are more frequent in seropositive than in seronegative blood donors. Several ECG abnormalities may help the recognition of seropositive cases with reduced LVEF who warrant careful follow-up and treatment.     

Electrocardiographic Changes Associated with Smoking and Smoking Cessation: Outcomes from a Randomized Controlled Trial

Introduction

Cardiovascular disease (CVD) can be detected and quantified by analysis of the electrocardiogram (ECG); however the effects of smoking and smoking cessation on the ECG have not been characterized.

Methods

Standard 12-lead ECGs were performed at baseline and 3 years after subjects enrolled in a prospective, randomized, placebo-controlled clinical trial of smoking cessation pharmacotherapies. ECGs were interpreted using the Minnesota Code ECG Classification. The effects of (i) smoking burden on the prevalence of ECG findings at baseline, and (ii) smoking and smoking cessation on ECG changes after 3 years were investigated by multivariable and multinomial regression analyses.

Results

At baseline, 532 smokers were (mean [SD]) 43.3 (11.5) years old, smoked 20.6 (7.9) cigarettes/day, with a smoking burden of 26.7 (18.6) pack-years. Major and minor ECG criteria were identified in 87 (16.4%) and 131 (24.6%) of subjects, respectively. After adjusting for demographic data and known CVD risk factors, higher pack-years was associated with major ECG abnormalities (p = 0.02), but current cigarettes/day (p = 0.23) was not. After 3 years, 42.9% of subjects were abstinent from smoking. New major and minor ECG criteria were observed in 7.2% and 15.6% of subjects respectively, but in similar numbers of abstinent subjects and continuing smokers (p>0.2 for both). Continuing smokers showed significant reduction in current smoking (–8.4 [8.8] cigarettes/day, p<0.001) compared to baseline.

Conclusions

In conclusion, major ECG abnormalities are independently associated with lifetime smoking burden. After 3 years, smoking cessation was not associated with a decrease in ECG abnormalities, although cigarettes smoked/day decreased among continuing smokers.     

Association between Exposure to Environmental Tobacco Smoke and Biomarkers of Oxidative Stress Among Patients Hospitalised with Acute Myocardial Infarction

Objective

To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction.

Design

An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction.

Setting

Nine acute hospitals in Scotland.

Participants

Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine ≥3.0 ng/mL) were compared with 60 never smokers who had not (admission serum cotinine ≤0.1 ng/mL).

Intervention

None.

Main outcome measures

Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA) and oxidised low-density lipoprotein (ox-LDL)) were measured on admission blood samples and adjusted for potential confounders.

Results

After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031) and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001) but not ox-LDL (beta coefficient 2.14, 95% CI −8.94, 13.21, p = 0.703).

Conclusions

Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.