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1.
Am J Respir Cell Mol Biol ; 70(6): 437-445, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38363828

RESUMO

The recent European Respiratory Society statement on familial pulmonary fibrosis supports the need for genetic testing in the care of patients and their relatives. However, no solution (i.e., a concrete test) was provided to implement genetic testing in daily practice. Herein, we tabulated and standardized the nomenclature of 128 genetic variants in 20 genes implicated in adult-onset pulmonary fibrosis. The objective was to develop a laboratory-developed test (LDT) on the basis of standard Sanger sequencing to capture all known familial pulmonary fibrosis-associated variants. Targeted DNA fragments were amplified using harmonized PCR conditions to perform the LDT in a single 96-well plate. The new genetic test was evaluated in 62 sporadic cases of idiopathic pulmonary fibrosis. As expected in this population, we observed a low yield of disease-causing mutations. More important, 100% of targeted variants by the LDT were successfully evaluated. Furthermore, four variants of uncertain significance with in silico-predicted deleterious scores were identified in three patients, suggesting novel pathogenic variants in genes known to cause idiopathic pulmonary fibrosis. Finally, the MUC5B promoter variant rs35705950 was strongly enriched in these patients with a minor allele frequency of 41.1% compared with 10.6% in a matched population-based cohort (n = 29,060), leading to an estimation that this variant may explain up to 35% of the population-attributable risk. This LDT provides a solution for rapid clinical translation. Technical laboratory details are provided so that specialized pulmonary centers can implement the LDT in house to expedite the clinical recommendations of expert panels.


Assuntos
Predisposição Genética para Doença , Testes Genéticos , Fibrose Pulmonar Idiopática , Mucina-5B , Humanos , Fibrose Pulmonar Idiopática/genética , Masculino , Feminino , Testes Genéticos/métodos , Mucina-5B/genética , Pessoa de Meia-Idade , Frequência do Gene , Mutação/genética , Idoso , Adulto , Regiões Promotoras Genéticas/genética
2.
Open Forum Infect Dis ; 11(1): ofad639, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38274551

RESUMO

Background: Pneumocystis jirovecii pneumonia (PJP) remains a significant threat in immunocompromised cases. Recent data on epidemiology and risk factors for PJP in non-HIV cases are scarce, and guidelines on appropriate prophylaxis are lacking. Methods: In this multicenter retrospective trial, all non-HIV adult cases admitted to hospitals in Québec City, Canada, between January 2011 and January 2021 with a diagnosis of PJP were assessed for eligibility. Results: An overall 129 cases of PJP were included. More than two-thirds had an underlying hematologic disease or an autoimmune/inflammatory condition. Prior to diagnosis, 83.7% were taking corticosteroids, 71.3% immunosuppressive agents (alone or in combination with corticosteroids), and 62% both. A diagnosis of PJP was noted in 22 patients receiving corticosteroids for treatment <28 days. Two patients developed PJP while undergoing corticosteroid monotherapy at a mean daily prednisone-equivalent dose <20 mg/d; 4.7% of our cohort received a PJP prophylaxis. Current recommendations or accepted clinical practices for PJP prophylaxis would not have applied to 48.8% of our patients. Conclusions: The use of corticosteroids-in monotherapy or in coadministration with other immunosuppressive agents-remains the principal risk factor for PJP in the non-HIV population. Current prophylaxis guidelines and accepted practices are insufficient to adequately prevent PJP and need to be broadened and updated.

3.
Am J Cardiovasc Dis ; 13(4): 283-290, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37736350

RESUMO

Sarcoidosis and systemic sclerosis are two inflammatory multisystemic disorders of unknown etiology that may be life-threatening especially when there is cardiac involvement. Both diseases may coexist, however, there are very few case reports of patients with both cardiac sarcoidosis and systemic sclerosis in the literature. We report the case of a 72-year-old female who was initially referred for dyspnea. A chest computed tomography scan showed multiple hilar and mediastinal adenopathy with a non-specific opacity in the middle pulmonary lobe. FDG-PET-scan showed increased FDG uptake in the adenopathy, the middle lobe and the right ventricular free wall. Sarcoidosis was confirmed with a lung biopsy. Both electrocardiogram and echocardiogram were normal. Four months later, the patient developed a high-grade atrioventricular block deemed secondary to her cardiac sarcoidosis. Two years later, the patient was referred to a rheumatologist for severe Raynaud's symptoms, sclerodactyly and acrocyanosis. After thorough investigations, a diagnosis of limited cutaneous systemic sclerosis with systemic and cardiac sarcoidosis was made. This case demonstrates that both cardiac sarcoidosis and systemic sclerosis may coexist. In the literature, either disease may come first. In cases where cardiac symptoms appear after the diagnosis of concomitant sarcoidosis and systemic sclerosis, it might be difficult for clinicians to confirm which disease is responsible for the heart involvement. This is important since early cardiac sarcoidosis treatment should be done to prevent major complications and may well differ from systemic sclerosis treatment. In this review, we discuss the main clinical manifestations and imaging findings seen with cardiac disease secondary to sarcoidosis and systemic sclerosis.

4.
Respir Care ; 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37491073

RESUMO

BACKGROUND: Exercise-induced O2 desaturation contributes to dyspnea and exercise intolerance in various respiratory diseases. This study assessed whether automated O2 titration was superior to fixed-flow O2 to improve exertional dyspnea and walking exercise endurance. We also aimed at evaluating possible additive effects of high-flow nasal cannula coupled with automated O2 titration on these outcomes. METHODS: Subjects with chronic respiratory diseases and exercise-induced desaturation performed a 3-min constant-speed shuttle test (CSST) and an endurance shuttle walking test (ESWT) with either (1) fixed-flow O2, (2) automated O2 titration targeting an SpO2 of 94% (± 2%), and (3) automated O2 titration + high-flow nasal cannula according to a randomized sequence. The main outcome was Borg dyspnea score at the end of the 3-min CSST. Secondary outcomes included endurance time and dyspnea during ESWT and oxygenation status during exercise. RESULTS: Ten subjects with COPD, 10 with interstitial lung disease, 5 with pulmonary hypertension, and 3 with cystic fibrosis completed the study. Compared to fixed-flow O2, automated O2 titration did not reduce dyspnea at the end of the 3-min CSST. Endurance time during the ESWT was prolonged with automated O2 titration (mean difference 298 [95% CI 205-391] s, P < .001), and dyspnea at isotime was reduced. No further improvement was noted when high-flow nasal cannula was added to automated O2 titration. Compared to fixed-flow O2, O2 flows were higher with automated O2 titration, resulting in better oxygenation. CONCLUSIONS: Automated O2 titration was superior to fixed-flow O2 to alleviate dyspnea and improve exercise endurance during the ESWT in subjects with a variety of chronic respiratory diseases. Adding high-flow nasal cannula to automated O2 titration provided no further benefits.

6.
Am J Respir Crit Care Med ; 207(12): 1612-1619, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-36796092

RESUMO

Rationale: Transbronchial cryobiopsy (TBCB) for the diagnosis of interstitial lung disease (ILD) has shown promising results, but prospective studies with matched surgical lung biopsy (SLB) have yielded conflicting results. Objectives: We aimed to assess within- and between-center diagnostic agreement between TBCB and SLB at both the histopathologic and multidisciplinary discussion (MDD) levels in patients with diffuse ILD. Methods: In a multicenter prospective study, we performed matched TBCB and SLB in patients referred for SLB. After a blinded review by three pulmonary pathologists, all cases were reviewed by three independent ILD teams in an MDD. MDD was performed first with TBCB, then with SLB in a second session. Within-center and between-center diagnostic agreement was evaluated using percentages and correlation coefficients. Measurements and Main Results: Twenty patients were recruited and underwent contemporaneous TBCB and SLB. Within-center diagnostic agreement between TBCB-MDD and SLB-MDD was reached in 37 of the 60 (61.7%) paired observations, resulting in a Cohen's κ value of 0.46 (95% confidence interval [CI], 0.29-0.63). Diagnostic agreement increased among high-confidence or definitive diagnoses on TBCB-MDD (21 of 29 [72.4%]), but not significantly, and was more likely among cases with SLB-MDD diagnoses of idiopathic pulmonary fibrosis than fibrotic hypersensitivity pneumonitis (13 of 16 [81.2%] vs. 16 of 31 [51.6%]; P = 0.047). Between-center agreement for cases was markedly higher for SLB-MDD (κ = 0.71 [95% CI, 0.52-0.89]) than TBCB-MDD (κ = 0.29 [95% CI, 0.09-0.49]). Conclusions: This study demonstrated moderate TBCB-MDD and SLB-MDD diagnostic agreement for ILD, while between-center agreement was fair for TBCB-MDD and substantial for SLB-MDD. Clinical trial registered with www.clinicaltrials.gov (NCT02235779).


Assuntos
Broncoscopia , Doenças Pulmonares Intersticiais , Humanos , Estudos Prospectivos , Broncoscopia/métodos , Pulmão/patologia , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/patologia , Biópsia/métodos
8.
ERJ Open Res ; 8(4)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36267896

RESUMO

Background: Patients with interstitial lung disease (ILD) often present with persistent dyspnoea and reduced exercise capacity and quality of life (QoL), but their functional limitation in relation to their frailty status remains unclear. We thus aimed to compare exercise tolerance, functional mobility, and muscle function and composition between ILD participants and healthy subjects and according to their frailty status. Methods: A total of 36 ILD participants and 15 heathy subjects performed a 6-min walk test, a 1-min sit-to-stand test, a Short Physical Performance Battery test, a hand grip test and complete quadriceps function testing. Patient-related impacts were assessed via questionnaires. Muscle composition was obtained using noncontrast computed tomography scans. The frailty status of patients with ILD was determined using the Fried frailty phenotype assessment. Results: Compared with control subjects, ILD participants exhibited significantly lower performance in every exercise and functional capacity test, higher dyspnoea and depression scores, and worse QoL. In ILD participants, the same observations were noted for the frail subgroup compared with the robust subgroup. No differences in muscle function and composition were observed between the ILD and control group, but mid-thigh muscle cross-sectional area and skeletal muscle index were significantly reduced in frail ILD participants. Conclusions: ILD patients present reduced exercise tolerance and functional capacity, and have decreased health-related QoL, when compared with healthy subjects. Physical frailty seems to be associated with worse clinical status, exercise tolerance, muscle and functional impairment, and decreased QoL. The 1-min sit-to-stand test may be a good discriminatory test for frailty status in ILD patients.

9.
Thorac Cardiovasc Surg ; 70(7): 583-588, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35151233

RESUMO

BACKGROUND: Surgical lung biopsy (SLB) is considered in the investigation of interstitial lung diseases (ILDs) when a complete clinical evaluation and a multidisciplinary discussion (MDD) do not allow the clinician to make a confident diagnosis. Owing to the risk of the procedure, an appropriate assessment of the risk/benefit ratio prior to the intervention is recommended. We aimed to assess the postoperative outcomes and diagnostic yield of SLB for the investigation of ILD in a tertiary care institution. METHODS: We conducted a retrospective cohort study of consecutive subjects who underwent a SLB for the investigation of ILD in our center from 2009 to 2020. The postoperative mortality and complications rates as well as the diagnostic yield of the procedure were assessed. RESULTS: Of the 1,805 patients newly investigated for ILD in our center from 2009 to 2020, 71 (3.93%) underwent a SLB. At days 30 and 90, the mortality rates were 0 and 2.8%, whereas 4.3 and 7.6% patients experienced an acute ILD exacerbation, respectively. In addition, 4 (5.8%) patients experienced infectious complications and 5 (7.0%) presented prolonged air leaks (all within 30 days). A definite pathological diagnosis was made in 47 (66.2%) patients. Following postoperative MDD, a confident diagnosis was made in 61 patients (85.9%) and resulted in a change of therapy in 49 (69.0%) patients. CONCLUSION: SLB for the diagnosis of unclassifiable ILDs is associated with low mortality but significant morbidity. However, it results in a confident diagnosis and a change in therapy in the majority of patients.


Assuntos
Doenças Pulmonares Intersticiais , Biópsia/efeitos adversos , Biópsia/métodos , Humanos , Pulmão/patologia , Pulmão/cirurgia , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
10.
IEEE Internet Things J ; 8(17): 13763-13773, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34722794

RESUMO

One of the major challenges faced by passive on-body wireless Internet of Things (IoT) sensors is the absorption of radiated power by tissues in the human body. We present a battery-less, wearable knitted Ultra High Frequency (UHF, 902-928 MHz) Radio Frequency Identification (RFID) compression sensor (Bellypatch) antenna and show its applicability as an on-body respiratory monitor. The antenna radiation efficiency is satisfactory in both free-space and on-body operations. We extract RF (Radio Frequency) sheet resistance values of three knitted silver-coated nylon fabric candidates at 913 MHz. The best type of fabric is selected based on the extracted RF sheet resistance. Simulated and measured performance of the antenna confirm suitability for on-body applications. The proposed Bellypatch antenna is used to measure the breathing activity of a programmable infant patient emulator mannequin (SimBaby) and a human subject. The antenna is highly sensitive to respiratory compression and relaxation. Fluctuations in the backscatter power level/Received Signal Strength Indicator (RSSI) in both cases range from 6 dB to 15 dB. The improved on-body read range of the proposed sensor antenna is 5.8 m, about 10 times higher than its predecessor wearable knitted strain sensing Bellyband antenna (0.6 m). The maximum simulated Specific Absorption Rate (SAR) on a human torso model is 0.25 W/kg, lower than the maximum allowable limit of 1.6 W/kg.

11.
Proc COMPSAC ; 2021: 774-784, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34568878

RESUMO

Currently, wired respiratory rate sensors tether patients to a location and can potentially obscure their body from medical staff. In addition, current wired respiratory rate sensors are either inaccurate or invasive. Spurred by these deficiencies, we have developed the Bellyband, a less invasive smart garment sensor, which uses wireless, passive Radio Frequency Identification (RFID) to detect bio-signals. Though the Bellyband solves many physical problems, it creates a signal processing challenge, due to its noisy, quantized signal. Here, we present an algorithm by which to estimate respiratory rate from the Bellyband. The algorithm uses an adaptively parameterized Savitzky-Golay (SG) filter to smooth the signal. The adaptive parameterization enables the algorithm to be effective on a wide range of respiratory frequencies, even when the frequencies change sharply. Further, the algorithm is three times faster and three times more accurate than the current Bellyband respiratory rate detection algorithm and is able to run in real time. Using an off-the-shelf respiratory monitor and metronome-synchronized breathing, we gathered 25 sets of data and tested the algorithm against these trials. The algorithm's respiratory rate estimates diverged from ground truth by an average Root Mean Square Error (RMSE) of 4.1 breaths per minute (BPM) over all 25 trials. Further, preliminary results suggest that the algorithm could be made as or more accurate than widely used algorithms that detect the respiratory rate of non-ventilated patients using data from an Electrocardiogram (ECG) or Impedance Plethysmography (IP).

12.
CJC Open ; 3(4): 532-548, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34027358

RESUMO

Sarcoidosis is an inflammatory multisystemic disease of unknown etiology characterized by the formation of noncaseating epithelioid cell granulomas. Cardiac sarcoidosis might be life-threatening and its diagnosis and treatment remain a challenge nowadays. The aim of this review is to provide an updated overview of cardiac sarcoidosis and, through 10 practical clinical questions and real-life challenging case scenarios, summarize the main clinical presentation, diagnostic criteria, imaging findings, and contemporary treatment.


La sarcoïdose est une maladie inflammatoire multisystémique de cause inconnue, caractérisée par la formation de granulomes non caséeux composés de cellules épithélioïdes. La sarcoïdose cardiaque est une pathologie potentiellement mortelle qui demeure, à ce jour, difficile à diagnostiquer et à traiter. L'objectif de cet article est de présenter les données les plus à jour concernant la sarcoïdose cardiaque et de résumer, à l'aide de 10 questions cliniques et de cas réels, la présentation clinique, les critères diagnostiques, les trouvailles à l'imagerie et le traitement contemporain.

13.
IEEE Access ; 9: 68523-68534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34012740

RESUMO

We propose an Ultra High Frequency (UHF) Radio Frequency Identification (RFID, 902-928 MHz in the US) channel emulation testbed that is capable of simultaneously emulating unique wireless channels. The proposed system can potentially be an invaluable tool in the design and validation of RFID-based Internet of Things (IoT) sensors and systems. Emulation of ray-tracing-based wireless channels enables the evaluation of inherently difficult and complex RF scenarios, particularly in situations when in-person experimentation is not feasible or desirable (e.g., during a pandemic or in a critical care facility). Furthermore, the emulation testbed is able to generate a large amount of sensor data in a limited time period. Machine learning techniques used in wireless IoT can be greatly enhanced by a large amount of data extracted from the emulation of dynamic and challenging environments. The proposed multi-channel emulation testbed is therefore a valuable solution for experimentation on real hardware and a convenient tool for pre-clinical-trial system validation.

14.
Small ; 16(26): e2002158, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32500606

RESUMO

Electroactive yarns that are stretchable are desired for many electronic textile applications, including energy storage, soft robotics, and sensing. However, using current methods to produce these yarns, achieving high loadings of electroactive materials and simultaneously demonstrating stretchability is a critical challenge. Here, a one-step bath electrospinning technique is developed to effectively capture Ti3 C2 Tx MXene flakes throughout continuous nylon and polyurethane (PU) nanofiber yarns (nanoyarns). With up to ≈90 wt% MXene loading, the resulting MXene/nylon nanoyarns demonstrate high electrical conductivity (up to 1195 S cm-1 ). By varying the flake size and MXene concentration, nanoyarns achieve stretchability of up to 43% (MXene/nylon) and 263% (MXene/PU). MXene/nylon nanoyarn electrodes offer high specific capacitance in saturated LiClO4 electrolyte (440 F cm-3 at 5 mV s-1 ), with a wide voltage window of 1.25 V and high rate capability (72% between 5 and 500 mV s-1 ). As strain sensors, MXene/PU yarns demonstrate a wide sensing range (60% under cyclic stretching), high sensitivity (gauge factor of ≈17 in the range of 20-50% strain), and low drift. Utilizing the stretchability of polymer nanofibers and the electrical and electrochemical properties of MXene, MXene-based nanoyarns demonstrate potential in a wide range of applications, including stretchable electronics and body movement monitoring.

15.
Med Sci Sports Exerc ; 52(12): 2508-2514, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32555023

RESUMO

PURPOSE: To assess the 1-min sit-to-stand test (1STS) test-retest reliability and construct validity and its associated cardiorespiratory response in comparison to the 6-min walk test (6MWT) and symptom-limited cycling cardiopulmonary exercise test (CPET) in people with interstitial lung disease (ILD). METHODS: Fifteen participants with ILD performed two 1STS tests, a 6MWT and a CPET. The three tests were administered on three separate visits, and cardiorespiratory parameters were continuously recorded during the tests. RESULTS: The number of repetitions during both 1STS tests was 22 ± 4 and 22 ± 4 (mean difference of 0.53 ± 2.00 repetitions, P = 0.32) with an intraclass correlation of 0.937 (95% confidence interval, 0.811-0.979]) and a minimal detectable change of 2.9 repetitions. The number of 1STS repetitions was highly correlated with the 6MWT distance (r = 0.823, P < 0.001) and with the peak cycling power output expressed in % predicted values (r = 0.706, P < 0.003). Oxygen consumption (V˙O2) peak during the 1STS reached 83% and 78% of V˙O2 peak during 6MWT and CPET, respectively. Peak 1STS HR, minute ventilation (V˙E,), V˙O2 values, as well as nadir SpO2 were achieved during the recovery phase of the test, whereas peak 6MWT and CPET HR, V˙E, V˙O2 and nadir SpO2 always occurred at the end of the test. The three tests elicited a similar fall in SpO2 ranging between 8% and 12%. Symptom scores after the 1STS were similar to those seen at the end of the 6MWT but lower than those of CPET. CONCLUSIONS: The 1STS showed excellent test-retest reliability in patients with ILD in whom it elicited a substantial, but submaximal cardiorespiratory response. Our data also support the construct validity of the 1STS to assess functional exercise capacity in patients with ILD and to detect exercise-induced O2 desaturation.


Assuntos
Teste de Esforço/métodos , Doenças Pulmonares Intersticiais/fisiopatologia , Consumo de Oxigênio/fisiologia , Postura Sentada , Posição Ortostática , Idoso , Pressão Sanguínea/fisiologia , Intervalos de Confiança , Dispneia/etiologia , Teste de Esforço/estatística & dados numéricos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Perna (Membro) , Masculino , Fadiga Muscular , Estudos Prospectivos , Reprodutibilidade dos Testes , Testes de Função Respiratória , Tamanho da Amostra , Fatores de Tempo , Teste de Caminhada/estatística & dados numéricos
16.
Am J Respir Cell Mol Biol ; 63(2): 209-218, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32289229

RESUMO

In a proportion of patients with hypersensitivity pneumonitis, the biological and environmental factors that sustain inflammation are ill defined, resulting in no effective treatment option. Bioaerosols found in occupational settings are complex and often include Toll-like receptor ligands, such as endotoxins. How Toll-like receptor ligands contribute to the persistence of hypersensitivity pneumonitis, however, remains poorly understood. In a previous study, we found that an S1P1 (sphingosine-1-phosphate receptor 1) agonist prevented the reactivation of antigen-driven B-cell responses in the lung. Here, we assessed the impact of endotoxins on B-cell activation in preexisting hypersensitivity pneumonitis and the role of S1P1 in this phenomenon. The impact of endotoxins on pre-established hypersensitivity pneumonitis was studied in vivo. S1P1 levels were tracked on B cells in the course of the disease using S1P1-eGFP knockin mice, and the role of S1P1 on B-cell functions was assessed using pharmacological tools. S1P1 was found on B cells in experimental hypersensitivity pneumonitis. Endotoxin exposure enhanced neutrophil accumulation in the BAL of mice with experimental hypersensitivity pneumonitis. This was associated with enhanced CD69 cell-surface expression on lymphocytes in the BAL. In isolated B cells, endotoxins increased cell-surface levels of costimulatory molecules and CD69, which was prevented by an S1P1 agonist. S1P1 modulators also reduced TNF production by B cells and their capacity to trigger T-cell cooperation ex vivo. An S1P1 ligand directly inhibited endotoxin-induced B-cell activation.


Assuntos
Alveolite Alérgica Extrínseca/imunologia , Linfócitos B/imunologia , Endotoxinas/imunologia , Receptores de Esfingosina-1-Fosfato/imunologia , Animais , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Feminino , Lectinas Tipo C/imunologia , Ativação Linfocitária/imunologia , Camundongos , Neutrófilos/imunologia
17.
ACS Cent Sci ; 6(2): 254-265, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32123744

RESUMO

The discovery of liquid crystalline (LC) phases in dispersions of two-dimensional (2D) materials has enabled the development of macroscopically aligned three-dimensional (3D) macrostructures. Here, we report the first experimental observation of self-assembled LC phases in aqueous Ti3C2T x MXene inks without using LC additives, binders, or stabilizing agents. We show that the transition concentration from the isotropic to nematic phase is influenced by the aspect ratio of MXene flakes. The formation of the nematic LC phase makes it possible to produce fibers from MXenes using a wet-spinning method. By changing the Ti3C2T x flake size in the ink formulation, coagulation bath, and spinning parameters, we control the morphology of the MXene fibers. The wet-spun Ti3C2T x fibers show a high electrical conductivity of ∼7750 S cm-1, surpassing existing nanomaterial-based fibers. A high volumetric capacitance of ∼1265 F cm-3 makes Ti3C2T x fibers promising for fiber-shaped supercapacitor devices. We also show that Ti3C2T x fibers can be used as heaters. Notably, the nematic LC phase can be achieved in other MXenes (Mo2Ti2C3T x and Ti2CT x ) and in various organic solvents, suggesting the widespread LC behavior of MXene inks.

18.
IET Microw Antennas Propag ; 14(3): 154-158, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35529428

RESUMO

Flexible antennas have the potential to transform wearable and fabric-based wireless sensing technologies. The antenna discussed in this study is part of a sensing system that uses the back-scattered power level as the decision metric. For a good wireless sensor, it is necessary to offer a feasible read range and maintain good distinctions in the back-scattered power levels between the different states (i.e. level of stretch) of the antenna. Moreover, effects due to human body proximity should be minimised. For these reasons, the radiation efficiency is a crucial parameter to investigate. This study presents the radiation efficiency measurement of the proposed flexible knitted 'Bellyband' antenna at two different levels of stretch in a reverberation chamber. This work validates the reverberation chamber measurements through comparison with simulations and anechoic chamber measurements at 900 MHz. Moreover, this work demonstrates how the approach can be used to quantify bellyband antenna efficiency in the vicinity of a human body. Finally, the efficiency results were used to predict the read range of Bellyband radio frequency identification technology.

19.
IEEE Antennas Wirel Propag Lett ; 19(4): 542-546, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34707465

RESUMO

Researchers are looking for new methods to integrate sensing capabilities into textiles while maintaining the durability, flexibility, and comfort of the garment. One method for imparting sensing capabilities into garments is through coupling conductive yarns with the radio frequency identification (RFID) technology. These smart devices have exhibited promising results for short-term use. However, long-term studies of their performance are still needed to evaluate their performance over a longer period. Like all garments, wearable sensors are susceptible to environmental factors during use. These factors can lead to dielectric coupling and corrosion of conductive yarns, which has the potential to degrade the performance of the device. This letter analyzes the effect of sweat and moisture on silver-coated nylon yarn by extracting the sheet resistance at 913 MHz from transmission line measurements. HFSS simulation shows the level of perturbation in antenna performance as sheet resistance increased with each cycle of sweat-immersion, washing, and drying.

20.
Biomacromolecules ; 20(6): 2252-2264, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31059233

RESUMO

Using transgenic silkworms with their natural spinning apparatus has proven to be a promising way to spin spider silk-like fibers. The challenges are incorporating native-size spider silk proteins and achieving an inheritable transgenic silkworm strain. In this study, a CRISPR/Cas9 initiated fixed-point strategy was used to successfully incorporate spider silk protein genes into the Bombyx mori genome. Native-size spider silk genes (up to 10 kb) were inserted into an intron of the fibroin heavy or light chain (FibH or FibL) ensuring that any sequence changes induced by the CRISPR/Cas9 would not impact protein production. The resulting fibers are as strong as native spider silks (1.2 GPa tensile strength). The transgenic silkworms have been tracked for several generations with normal inheritance of the transgenes. This strategy demonstrates the feasibility of using silkworms as a natural spider silk spinner for industrial production of high-performance fibers.


Assuntos
Animais Geneticamente Modificados , Bombyx , Sistemas CRISPR-Cas , Fibroínas , Aranhas/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/metabolismo , Bombyx/genética , Bombyx/metabolismo , Fibroínas/biossíntese , Fibroínas/genética
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