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1.
Langmuir ; 38(30): 9136-9147, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35849073

RESUMO

The potential applications of textile materials in fog harvesting have long been demonstrated. This work designed novel fog harvesters according to the distinct features of elastic textile threads (ETTs) to enhance droplet capture, large-droplet growth, and droplet pouring and improve fog harvesting efficiency. We prepared m@ETTs (modified ETTs) using three novel chemical and physical methods. First, we prepared spandex elastic threads with a non-uniform rough surface containing silica nanoparticles and titanium particles through the sol-gel triethoxymethylsilane method. Second, we prepared a rubber/polyester thread with a rough surface by breaking the thread shell with toluene solution, creating knots on the surface of the rubber core. Third, we prepared a polyurethane thread with a bumpy superhydrophobic surface by spraying a tetrafluoroethylene adhesive and silica nanoparticles on the thread. Furthermore, we connected ETTs to an automatic stretching-recovery system to obtain auto-ETTs as another group of harvesters. We obtained auto-i@ETTs by introducing elastic bumps/knots onto the auto-ETT surface. The fog harvesting efficiencies of m@ETTs were approximately 60-120% greater than those of the ETTs. The water harvesting rate of the auto-i@ETT was 2.5 times that of the ETT, with the highest water harvesting rate of auto-i@ETT reaching 3.35 g/h/cm2. Moreover, several novel principles of droplet behavior and thread elasticity were revealed. The elastic elongation level of the ETTs was proportional to their water harvesting efficiency. The stretching-recovery state of the elastic thread did not influence the water contact angle but affected the droplet state on the thread surface. The temporary slack/stick state of adjacent elastic threads on auto-ETTs contributed to droplet convergence and pouring. Overall, this novel approach demonstrates the significant potential of elastic threads in fog harvesting applications.


Assuntos
Borracha , Titânio , Dióxido de Silício , Têxteis , Água
2.
Proc Natl Acad Sci U S A ; 116(26): 12704-12709, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31182607

RESUMO

Effective, long-range, and self-propelled water elevation and transport are important in industrial, medical, and agricultural applications. Although research has grown rapidly, existing methods for water film elevation are still limited. Scaling up for practical applications in an energy-efficient way remains a challenge. Inspired by the continuous water cross-boundary transport on the peristome surface of Nepenthes alata, here we demonstrate the use of peristome-mimetic structures for controlled water elevation by bending biomimetic plates into tubes. The fabricated structures have unique advantages beyond those of natural pitcher plants: bulk water diode transport behavior is achieved with a high-speed passing state (several centimeters per second on a milliliter scale) and a gating state as a result of the synergistic effect between peristome-mimetic structures and tube curvature without external energy input. Significantly, on further bending the peristome-mimetic tube into a "candy cane"-shaped pipe, a self-siphon with liquid diode behavior is achieved. Such a transport mechanism should inspire the design of next generation water transport devices.


Assuntos
Biomimética/métodos , Capilares/fisiologia , Caryophyllales/anatomia & histologia , Microfluídica/métodos , Materiais Biomiméticos/química , Caryophyllales/fisiologia , Hidrogéis/química , Álcool de Polivinil/química , Impressão Tridimensional
3.
Anesth Analg ; 128(2): 349-357, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30169410

RESUMO

BACKGROUND: The diagnosis of postoperative cognitive dysfunction (POCD) requires complicated neuropsychological testing and is often delayed. Possible biomarkers for early detection or prediction are essential for the prevention and treatment of POCD. Preoperative screening of salivary cortisol levels may help to identify patients at elevated risk for POCD. METHODS: One hundred twenty patients >60 years of age and undergoing major noncardiac surgery underwent neuropsychological testing 1 day before and 1 week after surgery. Saliva samples were collected in the morning and the evening 1 day before surgery. POCD was defined as a Z-score of ≤-1.96 on at least 2 different tests. The primary outcome was the presence of POCD. The primary objective of this study was to assess the relationship between the ratio of AM (morning) to PM (evening) salivary cortisol levels and the presence of POCD. The secondary objective was to assess the relationship between POCD and salivary cortisol absolute values in the morning or in the evening. RESULTS: POCD was observed in 17.02% (16 of 94; 95% confidence interval [CI], 9.28%-24.76%) of patients 1 week after the operation. A higher preoperative AM/PM salivary cortisol ratio predicted early POCD onset (odds ratio [OR], 1.56; 95% CI, 1.20-2.02; P = .001), even after adjusting for the Mini-Mental Sate Examination score (odds ratio, 1.55; 95% CI, 1.19-2.02; P = .001). The area under the receiver operating characteristic curve for the salivary cortisol AM/PM ratio in individuals with POCD was 0.72 (95% CI, 0.56-0.88; P = .006). The optimal cutoff value was 5.69, with a sensitivity of 50% and specificity of 91%. CONCLUSIONS: The preoperative salivary cortisol AM/PM ratio was significantly associated with the presence of early POCD. This biomarker may have potential utility for screening patients for an increased risk and also for further elucidating the etiology of POCD.


Assuntos
Disfunção Cognitiva/metabolismo , Hidrocortisona/metabolismo , Complicações Pós-Operatórias/metabolismo , Cuidados Pré-Operatórios/tendências , Saliva/metabolismo , Idoso , Ritmo Circadiano/fisiologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Feminino , Humanos , Hidrocortisona/análise , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/psicologia , Valor Preditivo dos Testes , Cuidados Pré-Operatórios/métodos , Cuidados Pré-Operatórios/psicologia , Saliva/química
4.
J Colloid Interface Sci ; 619: 388-398, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35398769

RESUMO

HYPOTHESIS: The practical applications of boron nitride nanosheet (BNNS) are dramatically limited by the harsh exfoliation and surface functionalization conditions due to the hydrophobic and chemically inert nature. This issue can be improved by selecting efficient modifiers with hydrophilic groups. EXPERIMENTS: A green and scalable amino acid-assisted ball milling method is presented to exfoliate and functionalize BNNS simultaneously. The different interactions between BNNS and four amino acids (tryptophan (Trp), phenylalanine (Phe), arginine (Arg), lysine (Lys)) are thoroughly investigated to rationalize the thermal and mechanical properties of their corresponding epoxy (EP) composites. FINDING: Trp and Phe display higher functionalization degree and dispersibility of BNNS than Arg and Lys thanks to the additional π-π interactions between the aromatic groups and BNNS. Moreover, both BNNS-Trp/EP and BNNS-Phe/EP exhibit higher cross-plane thermal conductivity of 2.1 and 1.96 W m-1 K-1 at 30 wt% filler loading. In addition, the mechanical strengths of all these amino acids functionalized BNNS filled epoxy composites are significantly enhanced due to stronger interfacial interactions between fillers and epoxy matrix. Thus, this work paves the way for the facile mass production of functionalized BNNS and expedites their applications in thermal interface materials of electronic components.


Assuntos
Aminoácidos , Compostos de Boro , Compostos de Boro/química , Resinas Epóxi , Condutividade Térmica
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