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Patients undergoing kidney transplantation have a poor response to vaccination and a higher risk of disease progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The effectiveness of vaccine doses and antibody titer tests against the mutant variant in these patients remains unclear. We retrospectively analyzed the risk of SARS-CoV-2 infection in a single medical center according to vaccine doses and immune responses before the outbreak. Among 622 kidney transplant patients, there were 77 patients without vaccination, 26 with one dose, 74 with two doses, 357 with three, and 88 with four doses. The vaccination status and infection rate proportion were similar to the general population. Patients undergoing more than three vaccinations had a lower risk of infection (odds ratio = 0.6527, 95% CI = 0.4324-0.9937) and hospitalization (odds ratio = 0.3161, 95% CI = 0.1311-0.7464). Antibody and cellular responses were measured in 181 patients after vaccination. Anti-spike protein antibody titer of more than 1,689.3 BAU/mL is protective against SARS-CoV-2 infection (odds ratio = 0.4136, 95% CI = 0.1800-0.9043). A cellular response by interferon-γ release assay was not correlated with the disease (odds ratio = 1.001, 95% CI = 0.9995-1.002). In conclusion, despite mutant strain, more than three doses of the first-generation vaccine and high antibody titers provided better protection against the omicron variant for a kidney transplant recipient.
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COVID-19 , Trasplante de Riñón , Vacunas , Humanos , COVID-19/prevención & control , SARS-CoV-2 , Estudios RetrospectivosRESUMEN
The coaxial core/shell composite electrospun nanofibers consisting of relaxor ferroelectric P(VDF-TrFE-CTFE) and ferroelectric P(VDF-TrFE) polymers are successfully tailored towards superior structural, mechanical, and electrical properties over the individual polymers. The core/shell-TrFE/CTFE membrane discloses a more prominent mechanical anisotropy between the revolving direction (RD) and cross direction (CD) associated with a higher tensile modulus of 26.9 MPa and good strength-ductility balance, beneficial from a better degree of nanofiber alignment, the increased density, and C-F bonding. The interfacial coupling between the terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) is responsible for comparable full-frequency dielectric responses between the core/shell-TrFE/CTFE and pristine terpolymer. Moreover, an impressive piezoelectric coefficient up to 50.5 pm/V is achieved in the core/shell-TrFE/CTFE composite structure. Our findings corroborate the promising approach of coaxial electrospinning in efficiently tuning mechanical and electrical performances of the electrospun core/shell composite nanofiber membranes-based electroactive polymers (EAPs) actuators as artificial muscle implants.
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Clorofluorocarburos/química , Hidrocarburos Fluorados/química , Nanofibras/química , Compuestos de Vinilo/química , Fenómenos ElectromagnéticosRESUMEN
Coaxial core/shell electrospun nanofibers consisting of ferroelectric P(VDF-TrFE) and relaxor ferroelectric P(VDF-TrFE-CTFE) are tailor-made with hierarchical structures to modulate their mechanical properties with respect to their constituents. Compared with two single and the other coaxial membranes prepared in the research, the core/shell-TrFE/CTFE membrane shows a more prominent mechanical anisotropy between revolving direction (RD) and cross direction (CD) associated with improved resistance to tensile stress for the crystallite phase stability and good strength-ductility balance. This is due to the better degree of core/shell-TrFE-CTFE nanofiber alignment and the crystalline/amorphous ratio. The coupling between terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) is responsible for phase stabilization, comparing the core/shell-TrFE/CTFE with the pristine terpolymer. Moreover, an impressive collective deformation mechanism of a two-length scale in the core/shell composite structure is found. We apply in-situ synchrotron X-ray to resolve the two-length scale simultaneously by using the small-angle X-ray scattering to characterize the nanofibers and the wide-angle X-ray diffraction to identify the phase transformations. Our findings may serve as guidelines for the fabrication of the electrospun nanofibers used as membranes-based electroactive polymers.
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Nanofibras/química , Polivinilos/química , Dispersión del Ángulo Pequeño , Sincrotrones/instrumentación , Resistencia a la Tracción , Difracción de Rayos X/métodosRESUMEN
PURPOSE: Tacrolimus extended-release (TAC-ER; Astagraf XL® ) is utilized in many immunosuppressive regimens post-renal transplantation. Current dosing recommendation for the TAC-ER in renal transplant is 0.15-0.2 mg/kg/day administered once daily. The purpose of this study was to determine the best method of dosing TAC-ER in obese renal transplant recipients. METHODS: De novo obese kidney transplant recipients were randomized to receive TAC-ER 0.15 mg/kg/day based on either adjusted body weight (aBW) or ideal body weight (IBW). Post-transplant patients underwent three pharmacokinetic assessments over 14 days. The primary endpoint was the difference in TAC-ER exposure (AUC0-24) in obese patients dosed using aBW compared with IBW. RESULTS: A total of 20 obese renal transplant recipients were randomized to participate in the study (10 aBW and 10 IBW). Results of the primary outcome (AUC0-24) on Study Day 1, 7, and 14 were not statistically different between the two groups. There was no difference in the number of days to therapeutic trough concentration between the two dosing weights (aBW = 5.1, IBW = 4.9, days; P = 0.90). CONCLUSION: In a population of obese renal transplant recipients, comparable trough concentrations and overall exposure in both groups indicate that IBW may be preferred, as less initial drug was needed to attain adequate exposure.
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Rechazo de Injerto/tratamiento farmacológico , Supervivencia de Injerto/efectos de los fármacos , Inmunosupresores/farmacocinética , Fallo Renal Crónico/cirugía , Trasplante de Riñón/efectos adversos , Obesidad/tratamiento farmacológico , Tacrolimus/farmacocinética , Esquema de Medicación , Liberación de Fármacos , Femenino , Estudios de Seguimiento , Rechazo de Injerto/etiología , Rechazo de Injerto/patología , Humanos , Inmunosupresores/administración & dosificación , Masculino , Persona de Mediana Edad , Obesidad/fisiopatología , Pronóstico , Factores de Riesgo , Tacrolimus/administración & dosificaciónRESUMEN
BACKGROUND: Drug-related problems (DRPs) are common in recipients of solid organ transplants. Pharmacist-led medication therapy management (MTM) has cost benefits in kidney and liver transplants; however, whether MTM is also beneficial in heart transplants remains unclear. This study explored the cost benefits of involving pharmacists in the heart transplant clinic. METHODS: This retrospective study evaluated DRPs for 1 year after implementation of pharmacist-led MTM in a heart transplant clinic. The DRPs were compared between patients receiving transplantation for <1 and >1 year. The risk matrix method was used to assess each DRP in terms of the estimated probability and severity of consequent adverse drug events (ADEs). For cost analysis, both estimated cost savings and avoidance were calculated. RESULTS: During the 1-year MTM, 372 DRPs were identified by the pharmacist, among which 169 (45%) and 203 (55%) were from patients at <1-year and ≥1-year post-transplant periods, respectively. The 2 post-transplant periods (<1 year and ≥1 year) exhibited significant differences in the distribution of the dosage or frequency problems (30% vs 18%, P = .005) and the suggestion of more appropriate medication (4% vs 10%, P = .024). In all, 92 (29%) DRPs had an ADE probability of >10%; and 63 (17%) DRPs were estimated to cause ADEs with moderate severity or higher. The estimated cost savings and cost avoidance were US $4902 and US $4519, which equaled a cost-benefit ratio of 2.39. CONCLUSION: Integration of pharmacists into heart transplant clinics could help address DRPs and may have cost benefits.
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Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Trasplante de Corazón , Humanos , Administración del Tratamiento Farmacológico , Farmacéuticos , Análisis Costo-Beneficio , Estudios Retrospectivos , Trasplante de Corazón/efectos adversosRESUMEN
Adolescents' Internet health information usage has rarely been investigated. Adolescents seek all kinds of information from the Internet, including health information, which affects their Health Literacy that eHealth Literacy (eHL). This study is a retrospective observational study, we have total of 500 questionnaires were distributed, 87% of which were recovered, and we explored the channels that adolescents use to search for health information, their ability to identify false information, and factors affecting the type and content of health information queried. Adolescents believe that the Internet is a good means to seek health information because of its instant accessibility, frequent updating, convenience, and lack of time limits. More boys use the Internet to seek health information than girls in junior high schools (p = 0.009). The Internet is an important source of health information for adolescents but contains extensive misinformation that adolescents cannot identify. Additionally, adolescent boys and girls are interested in different health issues. Therefore, the government should implement measures to minimize misinformation on the Internet and create a healthy, educational online environment to promote Adolescents' eHealth Literacy (eHL).
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Alfabetización en Salud , Telemedicina , Adolescente , Estudios Transversales , Femenino , Alfabetización en Salud/métodos , Humanos , Internet , Masculino , Encuestas y Cuestionarios , Taiwán , Telemedicina/métodosRESUMEN
After kidney transplantation, patients exhibit a poor response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. However, the efficacy and adverse effects of vaccines based on different platforms in these patients remain unclear. We prospectively analyzed both anti-spike protein antibody and cellular responses 1 month after the first and second doses of SARS-CoV-2 vaccines in 171 kidney transplant patients. Four vaccines, including one viral vector (ChAdOx1 nCov-19, n = 30), two mRNA (mRNA1273, n = 81 and BNT162b2, n = 38), and one protein subunit (MVC-COV1901, n = 22) vaccines were administered. Among the four vaccines, mRNA1273 elicited the strongest humoral response and induced the highest interferon-γ levels in patients with a positive cellular response against the spike protein. Antiproliferative agents were negatively associated with both the antibody and cellular responses. A transient elevation in creatinine levels was noted in approximately half of the patients after the first dose of mRNA1273 or ChadOx1, and only one of them presented with borderline cellular rejection without definite causality to vaccination. In conclusion, mRNA1273 had better immunogenicity than the other vaccines. Further, renal function needs to be carefully monitored after vaccination, and vaccination strategies should be tailored according to the transplant status and vaccine characteristics.
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Vacunas contra la COVID-19 , COVID-19 , Trasplante de Riñón , Anticuerpos Antivirales , Vacuna BNT162 , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , ChAdOx1 nCoV-19 , Creatinina , Humanos , Interferón gamma , Trasplante de Riñón/efectos adversos , Subunidades de Proteína , ARN Mensajero , SARS-CoV-2 , Receptores de Trasplantes , Vacunación , Vacunas ViralesRESUMEN
Phage display of antibody fragments from natural or synthetic antibody libraries with the single chain constructs combining the variable fragments (scFv) has been one of the most prominent technologies in antibody engineering. However, the nature of the artificial single chain constructs results in unstable proteins expressed on the phage surface or as soluble proteins secreted in the bacterial culture medium. The stability of the variable domain structures can be enhanced with interdomain disulfide bond, but the single chain disulfide-stabilized constructs (sc-dsFv) have yet to be established as a feasible format for bacterial phage display due to diminishing expression levels on the phage surface in known phage display systems. In this work, biological combinatorial searches were used to establish that the c-region of the signal sequence is critically responsible for effective expression and functional folding of the sc-dsFv on the phage surface. The optimum signal sequences increase the expression of functional sc-dsFv by 2 orders of magnitude compared with wild-type signal sequences, enabling the construction of phage-displayed synthetic antivascular endothelial growth factor sc-dsFv libraries. Comparison of the scFv and sc-dsFv variants selected from the phage-displayed libraries for vascular endothelial growth factor binding revealed the sequence preference differences resulting from the interdomain disulfide bond. These results underlie a new phage display format for antibody fragments with all the benefits from the scFv format but without the downside due to the instability of the dimeric interface in scFv.
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Región Variable de Inmunoglobulina/química , Región Variable de Inmunoglobulina/genética , Biblioteca de Péptidos , Ingeniería de Proteínas/métodos , Factor A de Crecimiento Endotelial Vascular , Dimerización , Disulfuros/química , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/genética , Expresión Génica , Humanos , Cadenas Ligeras de Inmunoglobulina/química , Cadenas Ligeras de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/inmunología , Mutagénesis Sitio-Dirigida , Señales de Clasificación de Proteína/genética , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Factor A de Crecimiento Endotelial Vascular/química , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/inmunologíaRESUMEN
Phage-displayed single chain variable fragment (scFv) libraries are powerful tools in antibody engineering. Disulfide-stabilized scFv (sc-dsFv) with an interface disulfide bond is structure-wise more stable than the corresponding scFv. A set of recently discovered signal sequences replacing the wild type (pelB) signal peptidase cleavage site in the c-region has been shown to be effective in rescuing the expression of sc-dsFv libraries on the phage surface. However, the effects of the other regions of the signal sequence on the expression of the sc-dsFv libraries and on the formation of the interface disulfide bond in the phage-displayed sc-dsFv have not been clear. In this work, selected novel signal sequence variants in the h-region were shown to be equally effective in promoting sc-dsFv library expression on the phage surface; the expression level and complexity of the sc-dsFv libraries were comparable to the corresponding scFv libraries produced with the wild-type (pelB) signal sequence. The interface disulfide bond in the phage-displayed sc-dsFv was proven to form to a large extent in the library variant ensemble generated with signal sequence variants in both the h-region and the c-region. The sc-dsFv engineering platform established in this work can be applied to many of the known scFv molecules which are in need of a more stable version for the applications under harsh conditions or for longer shelf-life.
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Cisteína/química , Biblioteca de Péptidos , Señales de Clasificación de Proteína , Anticuerpos de Cadena Única/química , Anticuerpos de Cadena Única/genética , Factor A de Crecimiento Endotelial Vascular/inmunología , Secuencia de Aminoácidos , Humanos , Datos de Secuencia Molecular , Ingeniería de Proteínas , Estabilidad Proteica , Anticuerpos de Cadena Única/inmunología , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidoresRESUMEN
In this study, polycaprolactone (PCL)- and poly(acrylic acid) (PAA)-based electrospun nanofibers were prepared for the carriers of antimicrobials and designed composite nanofiber mats for chronic wound care. The PCL- and PAA-based electrospun nanofibers were prepared through in situ polymerization starting from PCL and acrylic acid (AA). Different amounts of AA were introduced to improve the hydrophilicity of the PCL electrospun nanofibers. A compatibilizer and a photoinitiator were then added to the electrospinning solution to form a grafted structure composed of PCL and PAA (PCL-g-PAA). The grafted PAA was mainly located on the surface of a PCL nanofiber. The optimization of the composition of PCL, AA, compatibilizer, and photoinitiator was studied, and the PCL-g-PAA electrospun nanofibers were characterized through scanning electron microscopy and 1H-NMR spectroscopy. Results showed that the addition of AA to PCL improved the hydrophilicity of the electrospun PCL nanofibers, and a PCL/AA ratio of 80/20 presented the best composition and had smooth nanofiber morphology. Moreover, poly[2 -(tert-butylaminoethyl) methacrylate]-grafted graphene oxide nanosheets (GO-g-PTA) functioned as an antimicrobial agent and was used as filler for PCL-g-PAA nanofibers in the preparation of composite nanofiber mats, which exerted synergistic effects promoted by the antibacterial properties of GO-g-PTA and the hydrophilicity of PCL-g-PAA electrospun nanofibers. Thus, the composite nanofiber mats had antibacterial properties and absorbed body fluids in the wound healing process, thereby promoting cell proliferation. The biodegradation of the PCL-g-PAA electrospun nanofibers also demonstrated an encouraging result of three-fold weight reduction compared to the neat PCL nanofiber. Our findings may serve as guidelines for the fabrication of electrospun nanofiber composites that can be used mats for chronic wound care.
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PURPOSE: The role of statins as anti-inflammatory drugs in chronic obstructive pulmonary disease (COPD) is controversial. This study aimed to determine the efficacy of statins used with or without corticosteroids in COPD patients. PATIENTS AND METHODS: This was a retrospective cohort study and used the two million outpatients and inpatients in Taiwan's Longitudinal Health Insurance Database covering 2000 to 2015. A total of 92,460 patients were identified in this study. We divided COPD patients into four groups by auditing each patient's medication (statins used or not; corticosteroids used or not) and used Cox regression to analyze and compare the effects of statins in COPD patients with or without corticosteroids. RESULTS: In terms of all COPD patients, our findings were consistent with previous studies showing that statins decreased COPD-related hospitalization and mortality rates. However, the beneficial effects were only observed in younger patients or those not taking corticosteroids in further analysis. Statins significantly decreased hospitalization and mortality rates in the non-corticosteroids groups. The hazard ratios increased with age and were not statistically significant for patients > 70 years old. Statins did not significantly decrease ED visits, hospitalization, and mortality in corticosteroids groups. CONCLUSION: Statins decreased hospitalization and mortality rates in COPD patients not taking corticosteroids but were not efficacious in patients on corticosteroids therapy. Furthermore, the beneficial effects of statins gradually decreased with patient age. Based on the findings, statins used in COPD patients may need to consider the patient age and corticosteroids used or not.
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Inhibidores de Hidroximetilglutaril-CoA Reductasas , Enfermedad Pulmonar Obstructiva Crónica , Corticoesteroides/efectos adversos , Anciano , Hospitalización , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Estudios RetrospectivosRESUMEN
Loneliness is a kind of mood that most people have experienced at one time or another. Individual experiences with loneliness as joyful or painful saturation are highly personal and can be defined only in such a context. Loneliness has differing effects on the long-term health of individuals. Although loneliness impacts greatly on individual health, there is little in the literature related to concept analyses of loneliness. The purpose of this article was to use Walker and Avant's (2005) concept analysis methodology to review conceptual definitions of loneliness, characteristics, antecedents and consequences; construct examples and establish empirical measurements. Results indicate that defining attributes of loneliness included an individual's subjective mood, descriptions of aloneness, depression, desolation or empty feelings, and the perception of the spirit isolated from others. It is hoped that nursing staffs may better understand loneliness through this article, provide an assessment of client loneliness as early as possible, and enhance client health condition.
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Soledad , Adulto , Femenino , Humanos , Soledad/psicología , Masculino , Persona de Mediana EdadRESUMEN
The study tested whether anserine (beta-alanyl-3-methyl-l-histidine), the active ingredient of chicken essence affects exercise-induced oxidative stress, cell integrity, and haematology biomarkers. In a randomized placebo-controlled repeated-measures design, ten healthy men ingested anserine in either a low dose (ANS-LD) 15 mg.kg-1.bw-1, high dose (ANS-HD) 30 mg.kg-1.bw-1, or placebo (PLA), following an exercise challenge (time to exhaustion), on three separate occasions. Anserine supplementation increased superoxide dismutase (SOD) by 50% (p < 0.001, effect size d = 0.8 for both ANS-LD and ANS-HD), and preserved catalase (CAT) activity suggesting an improved antioxidant activity. However, both ANS-LD and ANS-HD elevated glutathione disulfide (GSSG), (both p < 0.001, main treatment effect), and consequently lowered the glutathione to glutathione disulfide (GSH/GSSG) ratio compared with PLA (p < 0.01, main treatment effect), without significant effects on thiobarbituric acid active reactive substances (TBARS). Exercise-induced cell damage biomarkers of glutamic-oxaloacetic transaminase (GOT) and myoglobin were unaffected by anserine. There were slight but significant elevations in glutamate pyruvate transaminase (GPT) and creatine kinase isoenzyme (CKMB), especially in ANS-HD (p < 0.05) compared with ANS-LD or PLA. Haematological biomarkers were largely unaffected by anserine, its dose, and without interaction with post exercise time-course. However, compared with ANS-LD and PLA, ANS-HD increased the mean cell volume (MCV), and decreased the mean corpuscular haemoglobin concentration (MCHC) (p < 0.001). Anserine preserves cellular homoeostasis through enhanced antioxidant activity and protects cell integrity in healthy men, which is important for chronic disease prevention. However, anserine temporal elevated exercise-induced cell-damage, together with enhanced antioxidant activity and haematological responses suggest an augmented exercise-induced adaptative response and recovery.
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Anserina/administración & dosificación , Anserina/farmacología , Tamaño de la Célula/efectos de los fármacos , Suplementos Dietéticos , Ejercicio Físico/fisiología , Voluntarios Sanos , Homeostasis/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Adulto , Antioxidantes , Catalasa/metabolismo , Estudios Cruzados , Glutatión/metabolismo , Disulfuro de Glutatión/metabolismo , Hemoglobinas/metabolismo , Humanos , Masculino , Superóxido Dismutasa/metabolismo , Adulto JovenRESUMEN
Immunoassays based on sandwich immuno-complexes of capture and detection antibodies simultaneously binding to the target analytes have been powerful technologies in molecular analyses. Recent developments in single molecule detection technologies enable the detection limit of the sandwich immunoassays approaching femtomolar (10-15 M), driving the needs of developing sensitive and specific antibodies for ever-increasingly broad applications in detecting and quantifying biomarkers. The key components underlying the sandwich immunoassays are antibody-based affinity reagents, for which the conventional sources are mono- or poly-clonal antibodies from immunized animals. The downsides of the animal-based antibodies as affinity reagents arise from the requirement of months of development timespan and limited choices of antibody candidates due to immunodominance of humoral immune responses in animals. Hence, developing animal antibodies capable of distinguishing highly related antigens could be challenging. To overcome the limitation imposed by the animal immune systems, we developed an in vitro methodology based on phage-displayed synthetic antibody libraries for diverse antibodies as affinity reagents against closely related influenza virus nucleoprotein (NP) subtypes, aiming to differentiating avian influenza virus (H5N1) from seasonal influenza viruses (H1N1 and H3N2), for which the NPs are closely related by 90-94% in terms of pairwise amino acid sequence identity. We applied the methodology to attain, within four weeks, a panel of IgGs with distinguishable specificities against a group of representative NPs with pairwise amino acid sequence identities up to more than 90%, and the antibodies derived from the antibody libraries without further affinity refinement had comparable affinity of mouse antibodies to the NPs with the detection limit less than 1 nM of viral NP from lysed virus with sandwich ELISA. The panel of IgGs were capable of rapidly distinguishing infections due to virulent avian influenza virus from infections of seasonal flu, in responding to a probable emergency scenario where avian influenza virus would be transmissible among humans overlapping with the seasonal influenza infections. The results indicate that the in vitro antibody development methodology enables developing diagnostic antibodies that would not otherwise be available from animal-based antibody technologies.
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Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Virus de la Influenza A/inmunología , Biblioteca de Péptidos , Proteínas del Núcleo Viral/inmunología , Animales , Perros , Ensayo de Inmunoadsorción Enzimática , Humanos , Gripe Humana/diagnóstico , Gripe Humana/inmunología , Células de Riñón Canino Madin Darby , RatonesRESUMEN
We demonstrate a dual-operation-mode liquid crystal (LC) lens, which is fabricated with the silica nanoparticle-doped (SND) hybrid-aligned nematic (HAN) LC cell. With AC voltage, the cell behaves as a conventional LC lens. The response time of the SND HAN LC lens is faster than that of the conventional LC lens, which is fabricated using the pristine HAN LC cell. This is because that the doped silica nanoparticles may decrease the dielectric relaxation time constant of the cell. The addition of the silica nanoparticles also increases the viscosity of the LC host, suppresses the backflow motion of the LCs and then decreases the response time of the SND LC lens. With DC voltage, the electrophoretic motion of the doped silica nanoparticles and the agglomerate silica networks on the substrate surface cause the SND HAN LC cell to function as a bistable LC lens.
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Cristales Líquidos/química , Óptica y Fotónica/métodos , Diseño de Equipo , Vidrio , Rayos Láser , Lentes , Nanopartículas/química , Nanotecnología/métodos , Dióxido de Silicio/química , Propiedades de Superficie , Factores de Tiempo , Compuestos de Estaño/química , ViscosidadRESUMEN
The intensive measures of luminescence in a GaN/InGaN multiple quantum well system are used to examine the thermodynamics and phenomenological structure. The radiative /nonradiative transitions along with absorbed or emitted phonons that occur between the different quantum states of the electrons and holes associated with these processes make the quantum efficiency of a semiconductor nanosystem in an equilibrium state an extensive property. It has long been recognized that tuning of the indium (In) composition in InGaN interlayers gives the potential to obtain a spectrum in the near-infrared to near-ultraviolet spectral range. The thermodynamic intensive properties, including the Debye temperature, carrier temperature, and junction temperature, are the most appropriate metrics to describe the optical-related interactions inherent in a given heterostructure and so can be used as the state variables for understanding the quantum exchange behaviors. The energetic features of the quantum processes are characterized based on analysis of the intensive parameters as determined by means of electroluminescence (EL) and photoluminescence (PL) spectroscopy and current-voltage measurement and then correlated with the designed InGaN/GaN microstructures. According to the McCumber-Sturge theory, the EL and PL Debye temperatures obtained experimentally signal the strength of the electron-phonon and photon-phonon interaction, respectively, while the EL and PL carrier/junction temperatures correspond to the carrier localization. Higher EL Debye temperatures and lower EL carrier/junction temperatures reflect significantly higher luminescence quantum yields, indicative of electron-phonon coupling in the transfer of thermal energy between the confined electrons and the enhancement by excited phonons of heat-assisted emissions. On the other hand, the observation of low luminescence efficiency, corresponding to the lower PL Debye temperatures and higher PL carrier/junction temperatures, is attributed to photon-phonon coupling. These findings are in good accordance to the dependence of the EL and PL quantum efficiency on the In-content of the InGaN/GaN barriers, suggesting that the characteristic Debye and carrier/junction temperatures are intensive parameters useful for assessing the optical properties of a nano-engineered semiconductor heterostructure.
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Galio/química , Indio/química , Luminiscencia , Nanocompuestos/química , Semiconductores , Electrones , Diseño de Equipo , Fonones , TemperaturaRESUMEN
The development of RRAM is one of the mainstreams for next generation non-volatile memories to replace the conventional charge-based flash memory. More importantly, the simpler structure of RRAM makes it feasible to be integrated into a passive crossbar array for high-density memory applications. By stacking up the crossbar arrays, the ultra-high density of 3D horizontal RRAM (3D-HRAM) can be realized. However, 3D-HRAM requires critical lithography and other process for every stacked layer, and this fabrication cost overhead increases linearly with the number of stacks. Here, it is demonstrated that the 2D material-based vertical RRAM structure composed of graphene plane electrode/multilayer h-BN insulating dielectric stacked layers, AlOx/TiOx resistive switching layer and ITO pillar electrode exhibits reliable device performance including forming-free, low power consumption (Pset = ~2 µW and Preset = ~0.2 µW), and large memory window (>300). The scanning transmission electron microscopy indicates that the thickness of multilayer h-BN is around 2 nm. Due to the ultrathin-insulating dielectric and naturally high thermal conductivity characteristics of h-BN, the vertical structure combining the graphene plane electrode with multilayer h-BN insulating dielectric can pave the way toward a new area of ultra high-density memory integration in the future.
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Pandemic and epidemic outbreaks of influenza A virus (IAV) infection pose severe challenges to human society. Passive immunotherapy with recombinant neutralizing antibodies can potentially mitigate the threats of IAV infection. With a high throughput neutralizing antibody discovery platform, we produced artificial anti-hemagglutinin (HA) IAV-neutralizing IgGs from phage-displayed synthetic scFv libraries without necessitating prior memory of antibody-antigen interactions or relying on affinity maturation essential for in vivo immune systems to generate highly specific neutralizing antibodies. At least two thirds of the epitope groups of the artificial anti-HA antibodies resemble those of natural protective anti-HA antibodies, providing alternatives to neutralizing antibodies from natural antibody repertoires. With continuing advancement in designing and constructing synthetic scFv libraries, this technological platform is useful in mitigating not only the threats of IAV pandemics but also those from other newly emerging viral infections.
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Anticuerpos Neutralizantes/inmunología , Orthomyxoviridae/inmunología , Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/inmunología , Bacteriófagos/inmunología , Brotes de Enfermedades , Epítopos/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Virus de la Influenza A/inmunología , Gripe Humana/virología , Pandemias , Anticuerpos de Cadena Única/inmunologíaRESUMEN
Synapses between gustatory receptor cells and primary sensory afferent fibers transmit the output signal from taste buds to the CNS. Several transmitter candidates have been proposed for these synapses, including serotonin (5-HT), glutamate, acetylcholine, ATP, peptides, and others, but, to date, none has been unambiguously identified. We used Chinese hamster ovary cells stably expressing 5-HT2C receptors as biodetectors to monitor 5-HT release from taste buds. When taste buds were depolarized with KCl or stimulated with bitter, sweet, or sour (acid) tastants, serotonin was released. KCl- and acid-induced 5-HT release, but not release attributable to sweet or bitter stimulation, required Ca2+ influx. In contrast, 5-HT release evoked by sweet and bitter stimulation seemed to be triggered by intracellular Ca2+ release. These experiments strongly implicate serotonin as a taste bud neurotransmitter and reveal unexpected transmitter release mechanisms.
Asunto(s)
Serotonina/fisiología , Papilas Gustativas/fisiología , Adenosina Trifosfato/fisiología , Animales , Técnicas Biosensibles , Células CHO , Calcio/metabolismo , Cricetinae , Cricetulus , Femenino , Técnicas In Vitro , Mianserina/farmacología , Ratones , Ratones Endogámicos C57BL , Receptor de Serotonina 5-HT2C/fisiología , Serotonina/metabolismo , Antagonistas de la Serotonina/farmacología , Papilas Gustativas/metabolismoRESUMEN
The purpose of this study was to determine the association between the level of salivary dehydroepiandrosterone sulfate (DHEA-S) and the magnitude of adaptation to exercise training in insulin sensitivity for aged females. A group of 16 females, aged 80-93 years old, was divided into 2 groups according to their baseline DHEA-S levels: Lower Halves (N = 8) and Upper Halves (N = 8), and participated in a 4-month exercise intervention trial. Insulin response with an oral glucose tolerance test (OGTT), cholesterol, blood pressure (BP), motor performance, and DHEA-S were determined at baseline and 4 months after the training program. Glucose tolerance and body mass index (BMI) remained unchanged with training for both groups. Insulin, fasted cholesterol, diastolic blood pressure, reaction time, and locomotive function were significantly lowered by training only in the Upper Halves group. Changes in the area under curve of insulin (IAUC) were negatively correlated with the baseline DHEA-S level (R= - 0.60, P < 0.05). The current study provides the first evidence that oldest-old subjects with low DHEA-S level appear to be poor responders to exercise-training adaptations.