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1.
World J Emerg Med ; 12(4): 287-292, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512825

RESUMO

BACKGROUND: This study aims to compare the epidemiological, clinical and laboratory characteristics between patients with coronavirus disease (COVID-19) and influenza A (H1N1), and to develop a differentiating model and a simple scoring system. METHODS: We retrospectively analyzed the data from patients with COVID-19 and H1N1. The logistic regression model based on clinical and laboratory characteristics was constructed to distinguish COVID-19 from H1N1. Scores were assigned to each of independent discrimination factors based on their odds ratios. The performance of the prediction model and scoring system was assessed. RESULTS: A total of 236 patients were recruited, including 20 COVID-19 patients and 216 H1N1 patients. Logistic regression revealed that age >34 years, temperature ≤37.5 °C, no sputum or myalgia, lymphocyte ratio ≥20% and creatine kinase-myocardial band isoenzyme (CK-MB) >9.7 U/L were independent differentiating factors for COVID-19. The area under curves (AUCs) of the prediction model and scoring system in differentiating COVID-19 from H1N1 were 0.988 and 0.962, respectively. CONCLUSIONS: There are certain differences in clinical and laboratory features between patients with COVID-19 and H1N1. The simple scoring system may be a useful tool for the early identification of COVID-19 patients from H1N1 patients.

2.
Nat Mater ; 20(11): 1559-1570, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34326506

RESUMO

Flexible electronic/optoelectronic systems that can intimately integrate onto the surfaces of vital organ systems have the potential to offer revolutionary diagnostic and therapeutic capabilities relevant to a wide spectrum of diseases and disorders. The critical interfaces between such technologies and living tissues must provide soft mechanical coupling and efficient optical/electrical/chemical exchange. Here, we introduce a functional adhesive bioelectronic-tissue interface material, in the forms of mechanically compliant, electrically conductive, and optically transparent encapsulating coatings, interfacial layers or supporting matrices. These materials strongly bond both to the surfaces of the devices and to those of different internal organs, with stable adhesion for several days to months, in chemistries that can be tailored to bioresorb at controlled rates. Experimental demonstrations in live animal models include device applications that range from battery-free optoelectronic systems for deep-brain optogenetics and subdermal phototherapy to wireless millimetre-scale pacemakers and flexible multielectrode epicardial arrays. These advances have immediate applicability across nearly all types of bioelectronic/optoelectronic system currently used in animal model studies, and they also have the potential for future treatment of life-threatening diseases and disorders in humans.

3.
Nat Neurosci ; 24(7): 1035-1045, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33972800

RESUMO

Advanced technologies for controlled delivery of light to targeted locations in biological tissues are essential to neuroscience research that applies optogenetics in animal models. Fully implantable, miniaturized devices with wireless control and power-harvesting strategies offer an appealing set of attributes in this context, particularly for studies that are incompatible with conventional fiber-optic approaches or battery-powered head stages. Limited programmable control and narrow options in illumination profiles constrain the use of existing devices. The results reported here overcome these drawbacks via two platforms, both with real-time user programmability over multiple independent light sources, in head-mounted and back-mounted designs. Engineering studies of the optoelectronic and thermal properties of these systems define their capabilities and key design considerations. Neuroscience applications demonstrate that induction of interbrain neuronal synchrony in the medial prefrontal cortex shapes social interaction within groups of mice, highlighting the power of real-time subject-specific programmability of the wireless optogenetic platforms introduced here.


Assuntos
Optogenética/instrumentação , Comportamento Social , Tecnologia sem Fio/instrumentação , Animais , Camundongos
4.
BMC Nephrol ; 22(1): 176, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33985459

RESUMO

BACKGROUND: Combining tubular damage and functional biomarkers may improve prediction precision of acute kidney injury (AKI). Serum cystatin C (sCysC) represents functional damage of kidney, while urinary N-acetyl-ß-D-glucosaminidase (uNAG) is considered as a tubular damage biomarker. So far, there is no nomogram containing this combination to predict AKI in septic cohort. We aimed to compare the performance of AKI prediction models with or without incorporating these two biomarkers and develop an effective nomogram for septic patients in intensive care unit (ICU). METHODS: This was a prospective study conducted in the mixed medical-surgical ICU of a tertiary care hospital. Adults with sepsis were enrolled. The patients were divided into development and validation cohorts in chronological order of ICU admission. A logistic regression model for AKI prediction was first constructed in the development cohort. The contribution of the biomarkers (sCysC, uNAG) to this model for AKI prediction was assessed with the area under the receiver operator characteristic curve (AUC), continuous net reclassification index (cNRI), and incremental discrimination improvement (IDI). Then nomogram was established based on the model with the best performance. This nomogram was validated in the validation cohort in terms of discrimination and calibration. The decision curve analysis (DCA) was performed to evaluate the nomogram's clinical utility. RESULTS: Of 358 enrolled patients, 232 were in the development cohort (69 AKI), while 126 in the validation cohort (52 AKI). The first clinical model included the APACHE II score, serum creatinine, and vasopressor used at ICU admission. Adding sCysC and uNAG to this model improved the AUC to 0.831. Furthermore, incorporating them significantly improved risk reclassification over the predictive model alone, with cNRI (0.575) and IDI (0.085). A nomogram was then established based on the new model including sCysC and uNAG. Application of this nomogram in the validation cohort yielded fair discrimination with an AUC of 0.784 and good calibration. The DCA revealed good clinical utility of this nomogram. CONCLUSIONS: A nomogram that incorporates functional marker (sCysC) and tubular damage marker (uNAG), together with routine clinical factors may be a useful prognostic tool for individualized prediction of AKI in septic patients.

5.
Sci Adv ; 7(7)2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33568482

RESUMO

Accurate, real-time monitoring of intravascular oxygen levels is important in tracking the cardiopulmonary health of patients after cardiothoracic surgery. Existing technologies use intravascular placement of glass fiber-optic catheters that pose risks of blood vessel damage, thrombosis, and infection. In addition, physical tethers to power supply systems and data acquisition hardware limit freedom of movement and add clutter to the intensive care unit. This report introduces a wireless, miniaturized, implantable optoelectronic catheter system incorporating optical components on the probe, encapsulated by soft biocompatible materials, as alternative technology that avoids these disadvantages. The absence of physical tethers and the flexible, biocompatible construction of the probe represent key defining features, resulting in a high-performance, patient-friendly implantable oximeter that can monitor localized tissue oxygenation, heart rate, and respiratory activity with wireless, real-time, continuous operation. In vitro and in vivo testing shows that this platform offers measurement accuracy and precision equivalent to those of existing clinical standards.

6.
Semin Immunopathol ; 43(1): 29-43, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33449155

RESUMO

The thymus is the primary organ for T-cell development, providing an essential microenvironment consisting of the appropriate cytokine milieu and specialized stromal cells. Thymus-seeding progenitors from circulation immigrate into the thymus and undergo the stepwise T-cell specification, commitment, and selection processes. The transcriptional factors, epigenetic regulators, and signaling pathways involved in the T-cell development have been intensively studied using mouse models. Despite our growing knowledge of T-cell development, major questions remain unanswered regarding the ontogeny and early events of T-cell development at the fetal stage, especially in humans. The recently developed single-cell RNA-sequencing technique provides an ideal tool to investigate the heterogeneity of T-cell precursors and the molecular mechanisms underlying the divergent fates of certain T-cell precursors at the single-cell level. In this review, we aim to summarize the current progress of the study on human thymus organogenesis and thymocyte and thymic epithelial cell development, which is to shed new lights on developing novel strategies for in vitro T-cell regeneration and thymus rejuvenation.


Assuntos
Células Estromais , Timócitos , Diferenciação Celular , Células Epiteliais , Humanos , RNA , Timo
8.
IEEE Trans Biomed Eng ; 68(4): 1389-1398, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33079653

RESUMO

OBJECTIVE: High-density surface electromyography (HD-sEMG) has been utilized extensively in neuromuscular research. Despite its potential advantages, limitations in electrode design have largely prevented widespread acceptance of the technology. Commercial electrodes have limited spatial fidelity, because of a lack of sharpness of the signal, and variable signal stability. We demonstrate here a novel tattoo electrode that addresses these issues. Our dry HD electrode grid exhibits remarkable deformability which ensures superior conformity with the skin surface, while faithfully recording signals during different levels of muscle contraction. METHOD: We fabricated a 4 cm×3 cm tattoo HD electrode grid on a stretchable electronics membrane for sEMG applications. The grid was placed on the skin overlying the biceps brachii of healthy subjects, and was used to record signals for several hours while tracking different isometric contractions. RESULTS: The sEMG signals were recorded successfully from all 64 electrodes across the grid. These electrodes were able to faithfully record sEMG signals during repeated contractions while maintaining a stable baseline at rest. During voluntary contractions, broad EMG frequency content was preserved, with accurate reproduction of the EMG spectrum across the full signal bandwidth. CONCLUSION: The tattoo grid electrode can potentially be used for recording high-density sEMG from skin overlying major limb muscles. Layout programmability, good signal quality, excellent baseline stability, and easy wearability make this electrode a potentially valuable component of future HD electrode grid applications. SIGNIFICANCE: The tattoo electrode can facilitate high fidelity recording in clinical applications such as tracking the evolution and time-course of challenging neuromuscular degenerative disorders.


Assuntos
Tatuagem , Dispositivos Eletrônicos Vestíveis , Eletrodos , Eletromiografia , Humanos , Contração Isométrica , Músculo Esquelético
9.
Adv Healthc Mater ; 10(4): e2000722, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32989913

RESUMO

Eccrine sweat contains a rich blend of electrolytes, metabolites, proteins, metal ions, and other biomarkers. Changes in the concentrations of these chemical species can indicate alterations in hydration status and they can also reflect health conditions such as cystic fibrosis, schizophrenia, and depression. Recent advances in soft, skin-interfaced microfluidic systems enable real-time measurement of local sweat loss and sweat biomarker concentrations, with a wide range of applications in healthcare. Uses in certain contexts involve, however, physical impacts on the body that can dynamically deform these platforms, with adverse effects on measurement reliability. The work presented here overcomes this limitation through the use of microfluidic structures constructed in relatively high modulus polymers, and designed in geometries that offer soft, system level mechanics when embedded low modulus elastomers. Analytical models and finite element analysis quantitatively define the relevant mechanics of these systems, and serve as the basis for layouts optimized to allow robust operation in demanding, rugged scenarios such as those encountered in football, while preserving mechanical stretchability for comfortable, water-tight bonding to the skin. Benchtop testing and on-body field studies of measurements of sweat loss and chloride concentration under imposed mechanical stresses and impacts demonstrate the key features of these platforms.


Assuntos
Microfluídica , Suor , Eletrólitos , Reprodutibilidade dos Testes , Pele
10.
Proc Natl Acad Sci U S A ; 117(50): 31674-31684, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33257558

RESUMO

The standard of clinical care in many pediatric and neonatal neurocritical care units involves continuous monitoring of cerebral hemodynamics using hard-wired devices that physically adhere to the skin and connect to base stations that commonly mount on an adjacent wall or stand. Risks of iatrogenic skin injuries associated with adhesives that bond such systems to the skin and entanglements of the patients and/or the healthcare professionals with the wires can impede clinical procedures and natural movements that are critical to the care, development, and recovery of pediatric patients. This paper presents a wireless, miniaturized, and mechanically soft, flexible device that supports measurements quantitatively comparable to existing clinical standards. The system features a multiphotodiode array and pair of light-emitting diodes for simultaneous monitoring of systemic and cerebral hemodynamics, with ability to measure cerebral oxygenation, heart rate, peripheral oxygenation, and potentially cerebral pulse pressure and vascular tone, through the utilization of multiwavelength reflectance-mode photoplethysmography and functional near-infrared spectroscopy. Monte Carlo optical simulations define the tissue-probing depths for source-detector distances and operating wavelengths of these systems using magnetic resonance images of the head of a representative pediatric patient to define the relevant geometries. Clinical studies on pediatric subjects with and without congenital central hypoventilation syndrome validate the feasibility for using this system in operating hospitals and define its advantages relative to established technologies. This platform has the potential to substantially enhance the quality of pediatric care across a wide range of conditions and use scenarios, not only in advanced hospital settings but also in clinics of lower- and middle-income countries.


Assuntos
Técnicas Biossensoriais , Circulação Cerebrovascular/fisiologia , Monitorização Hemodinâmica/instrumentação , Transtornos do Neurodesenvolvimento/diagnóstico , Monitorização Neurofisiológica/instrumentação , Adolescente , Criança , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Feminino , Monitorização Hemodinâmica/métodos , Humanos , Lactente , Masculino , Transtornos do Neurodesenvolvimento/fisiopatologia , Monitorização Neurofisiológica/métodos , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio/instrumentação
11.
Nat Commun ; 11(1): 5990, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33239608

RESUMO

Bioresorbable electronic stimulators are of rapidly growing interest as unusual therapeutic platforms, i.e., bioelectronic medicines, for treating disease states, accelerating wound healing processes and eliminating infections. Here, we present advanced materials that support operation in these systems over clinically relevant timeframes, ultimately bioresorbing harmlessly to benign products without residues, to eliminate the need for surgical extraction. Our findings overcome key challenges of bioresorbable electronic devices by realizing lifetimes that match clinical needs. The devices exploit a bioresorbable dynamic covalent polymer that facilitates tight bonding to itself and other surfaces, as a soft, elastic substrate and encapsulation coating for wireless electronic components. We describe the underlying features and chemical design considerations for this polymer, and the biocompatibility of its constituent materials. In devices with optimized, wireless designs, these polymers enable stable, long-lived operation as distal stimulators in a rat model of peripheral nerve injuries, thereby demonstrating the potential of programmable long-term electrical stimulation for maintaining muscle receptivity and enhancing functional recovery.


Assuntos
Implantes Absorvíveis , Terapia por Estimulação Elétrica/instrumentação , Traumatismos dos Nervos Periféricos/terapia , Poliuretanos/química , Tecnologia sem Fio/instrumentação , Animais , Modelos Animais de Doenças , Terapia por Estimulação Elétrica/métodos , Feminino , Humanos , Teste de Materiais , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Ratos , Regeneração , Nervo Isquiático/lesões , Nervo Isquiático/fisiologia
12.
BMC Nephrol ; 21(1): 519, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33246435

RESUMO

BACKGROUND: Glucocorticoids may impact the accuracy of serum cystatin C (sCysC) in reflecting renal function. We aimed to assess the effect of glucocorticoids on the performance of sCysC in detecting acute kidney injury (AKI) in critically ill patients. METHODS: A prospective observational cohort study was performed in a general intensive care unit (ICU). Using propensity score matching, we successfully matched 240 glucocorticoid users with 960 non-users among 2716 patients. Serum creatinine (SCr) and sCysC were measured for all patients at ICU admission. Patients were divided into four groups based on cumulative doses of glucocorticoids within 5 days before ICU admission (Group I: non-users; Group II: 0 mg < prednisone ≤50 mg; Group III: 50 mg < prednisone ≤150 mg; Group IV: prednisone > 150 mg). We compared the performance of sCysC for diagnosing and predicting AKI in different groups using the area under the receiver operator characteristic curve (AUC). RESULTS: A total of 240 patients received glucocorticoid medication within 5 days before ICU admission. Before and after matching, the differences of sCysC levels between glucocorticoid users and non-users were both significant (P <  0.001). The multiple linear regression analysis revealed that glucocorticoids were independently associated with sCysC (P <  0.001). After matching, the group I had significantly lower sCysC levels than the group III and group IV (P <  0.05), but there were no significant differences in sCysC levels within different glucocorticoids recipient groups (P > 0.05). Simultaneously, we did not find significant differences in the AUC between any two groups in the matched cohort (P > 0.05). CONCLUSIONS: Glucocorticoids did not impact the performance of sCysC in identifying AKI in critically ill patients.

13.
NPJ Digit Med ; 3: 29, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195364

RESUMO

Hydrocephalus is a common disorder caused by the buildup of cerebrospinal fluid (CSF) in the brain. Treatment typically involves the surgical implantation of a pressure-regulated silicone tube assembly, known as a shunt. Unfortunately, shunts have extremely high failure rates and diagnosing shunt malfunction is challenging due to a combination of vague symptoms and a lack of a convenient means to monitor flow. Here, we introduce a wireless, wearable device that enables precise measurements of CSF flow, continuously or intermittently, in hospitals, laboratories or even in home settings. The technology exploits measurements of thermal transport through near-surface layers of skin to assess flow, with a soft, flexible, and skin-conformal device that can be constructed using commercially available components. Systematic benchtop studies and numerical simulations highlight all of the key considerations. Measurements on 7 patients establish high levels of functionality, with data that reveal time dependent changes in flow associated with positional and inertial effects on the body. Taken together, the results suggest a significant advance in monitoring capabilities for patients with shunted hydrocephalus, with potential for practical use across a range of settings and circumstances, and additional utility for research purposes in studies of CSF hydrodynamics.

14.
Nat Mater ; 19(3): 292-298, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32015531

RESUMO

The spin Hall effect (SHE) is usually observed as a bulk effect in high-symmetry crystals with substantial spin-orbit coupling (SOC), where the symmetric spin-orbit field imposes a widely encountered trade-off between spin Hall angle (θSH) and spin diffusion length (Lsf), and spin polarization, spin current and charge current are constrained to be mutually orthogonal. Here, we report a large θSH of 0.32 accompanied by a long Lsf of 2.2 µm at room temperature in a low-symmetry few-layered semimetal MoTe2, thus identifying it as an excellent candidate for simultaneous spin generation, transport and detection. In addition, we report that longitudinal spin current with out-of-plane polarization can be generated by both transverse and vertical charge current, due to the conventional and a newly observed planar SHE, respectively. Our study suggests that manipulation of crystalline symmetries and strong SOC opens access to new charge-spin interconversion configurations and spin-orbit torques for spintronic applications.

15.
Kidney Blood Press Res ; 45(1): 142-156, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31927548

RESUMO

BACKGROUND: Postoperative acute kidney injury (AKI) is frequent and associated with adverse outcomes. Unfortunately, the early diagnosis of AKI remains a challenge. Combining functional and tubular damage biomarkers may provide better precision for AKI detection. However, the diagnostic accuracy of this combination for AKI after neurosurgery is unclear. Serum cystatin C (sCysC) and urinary albumin/creatinine ratio (uACR) are considered functional biomarkers, while urinary N-acetyl-ß-D-glucosaminidase (uNAG) represents tubular damage. We aimed to assess the performances of these clinical available biomarkers and their combinations for AKI prediction after resection of intracranial space-occupying lesions. METHODS: A prospective study was conducted, enrolling adults undergoing resection of intracranial space-occupying lesions and admitted to the neurosurgical intensive care unit. The discriminative abilities of postoperative sCysC, uNAG, uACR, and their combinations in predicting AKI were compared using the area under the receiver operating characteristic curve (AUC-ROC), continuous net reclassification index (cNRI), and incremental discrimination improvement (IDI). RESULTS: Of 605 enrolled patients, AKI occurred in 67 patients. The cutoff values of sCysC, uNAG, and uACR to predict postoperative AKI were 0.72 mg/L, 19.98 U/g creatinine, and 44.21 mg/g creatinine, respectively. For predicting AKI, the composite of sCysC and uNAG (AUC-ROC = 0.785) outperformed either individual biomarkers or the other two panels (uNAG plus uACR or sCysC plus uACR). Adding this panel to the predictive model improved the AUC-ROC to 0.808. Moreover, this combination significantly improved risk reclassification over the clinical model alone, with cNRI (0.633) and IDI (0.076). Superior performance of this panel was further confirmed with bootstrap internal validation. CONCLUSIONS: Combination of functional and tubular damage biomarkers improves the predictive accuracy for AKI after resection of intracranial space-occupying lesions.


Assuntos
Acetilglucosaminidase/metabolismo , Injúria Renal Aguda/diagnóstico , Neoplasias Encefálicas/complicações , Encéfalo/patologia , Cistatina C/metabolismo , Acetilglucosaminidase/urina , Injúria Renal Aguda/etiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
16.
Science ; 367(6480): 895-900, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31974160

RESUMO

In a magnetic topological insulator, nontrivial band topology combines with magnetic order to produce exotic states of matter, such as quantum anomalous Hall (QAH) insulators and axion insulators. In this work, we probe quantum transport in MnBi2Te4 thin flakes-a topological insulator with intrinsic magnetic order. In this layered van der Waals crystal, the ferromagnetic layers couple antiparallel to each other; atomically thin MnBi2Te4, however, becomes ferromagnetic when the sample has an odd number of septuple layers. We observe a zero-field QAH effect in a five-septuple-layer specimen at 1.4 kelvin, and an external magnetic field further raises the quantization temperature to 6.5 kelvin by aligning all layers ferromagnetically. The results establish MnBi2Te4 as an ideal arena for further exploring various topological phenomena with a spontaneously broken time-reversal symmetry.

17.
Nat Biomed Eng ; 4(2): 148-158, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31768002

RESUMO

Skin-mounted soft electronics that incorporate high-bandwidth triaxial accelerometers can capture broad classes of physiologically relevant information, including mechano-acoustic signatures of underlying body processes (such as those measured by a stethoscope) and precision kinematics of core-body motions. Here, we describe a wireless device designed to be conformally placed on the suprasternal notch for the continuous measurement of mechano-acoustic signals, from subtle vibrations of the skin at accelerations of around 10-3 m s-2 to large motions of the entire body at about 10 m s-2, and at frequencies up to around 800 Hz. Because the measurements are a complex superposition of signals that arise from locomotion, body orientation, swallowing, respiration, cardiac activity, vocal-fold vibrations and other sources, we exploited frequency-domain analysis and machine learning to obtain-from human subjects during natural daily activities and exercise-real-time recordings of heart rate, respiration rate, energy intensity and other essential vital signs, as well as talking time and cadence, swallow counts and patterns, and other unconventional biomarkers. We also used the device in sleep laboratories and validated the measurements using polysomnography.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Fenômenos Fisiológicos , Tecnologia sem Fio/instrumentação , Clavícula , Desenho de Equipamento , Exercício Físico/fisiologia , Humanos , Processamento de Sinais Assistido por Computador , Fenômenos Fisiológicos da Pele , Sono/fisiologia , Vibração
18.
ACS Appl Mater Interfaces ; 12(2): 3042-3050, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31860263

RESUMO

Inspired by nature, large-area stable superhydrophobic poly(dimethylsiloxane) (PDMS) films have generated extensive interest for various applications such as self-cleaning, corrosion protection, liquid transport, optical services, and flexible electronics. However, the current methods used to prepare such films are difficult to apply for efficient large-area fabrication. In this article, an effective technique for fabricating low adhesive superhydrophobic films based on the use of a chemically etched template followed by a thermal curing process is introduced. On the basis of this approach, the importance of chemical solution concentration as well as etching time is discussed to outline the specific rules required for forming different surface topographies of the templates. Then, PDMS films with varying wettabilities can be fabricated in which one can achieve CA > 160° and SA < 10°. Finally, for engineering needs and actual preparation, large-area PDMS films are obtained via a roll-to-roll (R2R) process, which show a superhydrophobic property even after high-intensity friction and have excellent acid and alkaline resistance, UV resistance, and optical transparency. The prepared large-area stable superhydrophobic PDMS films have the potential to be used in the aerospace field in the future because of their excellent anti-icing performance.

19.
NPJ Digit Med ; 3(1): 29, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33594221

RESUMO

Hydrocephalus is a common disorder caused by the buildup of cerebrospinal fluid (CSF) in the brain. Treatment typically involves the surgical implantation of a pressure-regulated silicone tube assembly, known as a shunt. Unfortunately, shunts have extremely high failure rates and diagnosing shunt malfunction is challenging due to a combination of vague symptoms and a lack of a convenient means to monitor flow. Here, we introduce a wireless, wearable device that enables precise measurements of CSF flow, continuously or intermittently, in hospitals, laboratories or even in home settings. The technology exploits measurements of thermal transport through near-surface layers of skin to assess flow, with a soft, flexible, and skin-conformal device that can be constructed using commercially available components. Systematic benchtop studies and numerical simulations highlight all of the key considerations. Measurements on 7 patients establish high levels of functionality, with data that reveal time dependent changes in flow associated with positional and inertial effects on the body. Taken together, the results suggest a significant advance in monitoring capabilities for patients with shunted hydrocephalus, with potential for practical use across a range of settings and circumstances, and additional utility for research purposes in studies of CSF hydrodynamics.

20.
Nat Commun ; 10(1): 5513, 2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797921

RESUMO

Recently introduced classes of thin, soft, skin-mounted microfluidic systems offer powerful capabilities for continuous, real-time monitoring of total sweat loss, sweat rate and sweat biomarkers. Although these technologies operate without the cost, complexity, size, and weight associated with active components or power sources, rehydration events can render previous measurements irrelevant and detection of anomalous physiological events, such as high sweat loss, requires user engagement to observe colorimetric responses. Here we address these limitations through monolithic systems of pinch valves and suction pumps for purging of sweat as a reset mechanism to coincide with hydration events, microstructural optics for reversible readout of sweat loss, and effervescent pumps and chemesthetic agents for automated delivery of sensory warnings of excessive sweat loss. Human subject trials demonstrate the ability of these systems to alert users to the potential for dehydration via skin sensations initiated by sweat-triggered ejection of menthol and capsaicin.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Pele/metabolismo , Suor/metabolismo , Biomarcadores/metabolismo , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Retroalimentação Fisiológica , Humanos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Estado de Hidratação do Organismo , Reprodutibilidade dos Testes , Pele/química , Suor/química
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