Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Chemistry ; 30(33): e202400629, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38594211

RESUMEN

Herein, we synthesized two donor-acceptor (D-A) type small organic molecules with self-assembly properties, namely MPA-BT-BA and MPA-2FBT-BA, both containing a low acidity anchoring group, benzoic acid. After systematically investigation, it is found that, with the fluorination, the MPA-2FBT-BA demonstrates a lower highest occupied molecular orbital (HOMO) energy level, higher hole mobility, higher hydrophobicity and stronger interaction with the perovskite layer than that of MPA-BT-BA. As a result, the device based-on MPA-2FBT-BA displays a better crystallization and morphology of perovskite layer with larger grain size and less non-radiative recombination. Consequently, the device using MPA-2FBT-BA as hole transport material achieved the power conversion efficiency (PCE) of 20.32 % and remarkable stability. After being kept in an N2 glove box for 116 days, the unsealed PSCs' device retained 93 % of its initial PCE. Even exposed to air with a relative humidity range of 30±5 % for 43 days, its PCE remained above 91 % of its initial condition. This study highlights the vital importance of the fluorination strategy combined with a low acidity anchoring group in SAMs, offering a pathway to achieve efficient and stable PSCs.

2.
Small ; : e2307840, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-38054757

RESUMEN

All inorganic perovskite based on CsPbI2 Br has attracted significant attention due to its relatively thermal stable structure compare to its hybrid counterparts. With a wide bandgap of 1.9 eV and excellent light absorption capability, it has been extensively explored for applications in indoor photovoltaics and as a front absorber in tandem devices. However, the uncontrollable crystallization process during solvent evaporation and thermal annealing leads to both macroscopic defects like cracks and microscopic defects such as voids. In this study, a metastable adduct with lead (II) halides by incorporating 4-tert-butyl pyridine as a volatile Lewis base monodentate ligand in the precursor solution is formed. The strategic preferential decomposition of the adduct during the early-stage low-temperature annealing facilitated the desorption of lead (II) halides, inducing antisolvent-free heterogenous nucleation. This, in turn, promoted crystal growth during subsequent high-temperature annealing, resulting in dense films with low defect density. As a result, a maximum open-circuit voltage of 1.30 V is achieved with the champion power conversion efficiency of 16.5% in CsPbI2 Br-based perovskite solar cell. The work reveals a new mechanism of using Lewis acid-base adduct to obtain high quality perovskite films other than hindering crystallization in traditional way.

3.
Chemistry ; 28(26): e202104316, 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35253943

RESUMEN

Two-dimensional (2D) hybrid perovskites with novel functionalities and structural diversity are a perfect platform for emerging optoelectronic devices such as photodetectors, light-emitting diodes, and solar cells. Here, we demonstrate that excess concentration of Cesium bromide (CsBr) is key to the formation of easily exfoliated 2D Cs2 Cu(Cl/Br)4 perovskite crystal. Furthermore, by employing this trick to 2D perovskite MA2 Cu(Cl/Br)4 (MA=methylammonium), we achieve a phase-pure easily exfoliated 2D mixed-cation (MA/Cs)2 Cu(Cl/Br)4 perovskite crystal, which exhibits reduced bandgap (1.53 eV) with ferromagnetic behavior and photovoltaic property. The resultant mixed-cation structured device reveals enhanced efficiency compared to all MA and all Cs counterparts. These findings demonstrate the importance of cation-engineering in developing innovative materials with novel properties.

4.
Int J Equity Health ; 21(1): 190, 2022 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-36585709

RESUMEN

BACKGROUND: Hepatitis B causes significant disease and death globally, despite the availability of effective vaccination. Migration likewise affects hundreds of millions of people annually, many of whom are women and children, and increases risks for poor vaccine completion and mother to child transmission of hepatitis B. In the neighbouring countries of Thailand and Myanmar, vaccine campaigns have made progress but little is known about the reach of these programs into migrant worker communities from Myanmar living in Thailand. METHODS: A cohort of 253 postpartum women (53 urban migrants in Chiang Mai and 200 rural migrants in Tak Province) were surveyed about their Hepatitis B knowledge and willingness to vaccinate their children between September 10, 2019 and March 30, 2019. They were subsequently followed to determine vaccine completion. When records of vaccination were unavailable at the birth facility, or visits were late, families were contacted and interviewed about vaccination elsewhere, and reasons for late or missed vaccines. RESULTS: Though women in Tak province displayed better knowledge of Hepatitis B and equal intention to vaccinate, they were 14 times less likely to complete Hepatitis B vaccination for their children compared to migrants in Chiang Mai. Tak women were largely undocumented, had private (non-profit) insurance and had more transient residence. In Chiang Mai migrant women were mostly documented and had full access to the Thai national health services. Though minor individual and facility-level differences may have contributed, the major driver of the disparity seems to be the place of migrants within local socio-political-economic systems. The COVID-19 pandemic further disproportionately affected Tak province migrants who faced severe travel restrictions hampering vaccination. Sixty percent of families who were lost to vaccine follow-up in Tak province could not be contacted by phone or home visit. Chiang Mai migrants, with 86.8% vaccine completion, nearly reached the target of 90%. CONCLUSIONS: Achievement of high levels of hepatitis B vaccination in migrant communities is important and feasible, and requires inclusive policies that integrate migrants into national health and social services. This is more urgent than ever during the COVID-19 era.


Asunto(s)
COVID-19 , Hepatitis B , Migrantes , Vacunas , Niño , Humanos , Femenino , Lactante , Masculino , Tailandia/epidemiología , Pandemias , Estudios Prospectivos , COVID-19/prevención & control , Transmisión Vertical de Enfermedad Infecciosa , Vacunación , Hepatitis B/prevención & control
5.
Small ; 15(49): e1904715, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31642190

RESUMEN

A new hole transporting material (HTM) named DMZ is synthesized and employed as a dopant-free HTM in inverted planar perovskite solar cells (PSCs). Systematic studies demonstrate that the thickness of the hole transporting layer can effectively enhance the morphology and crystallinity of the perovskite layer, leading to low series resistance and less defects in the crystal. As a result, the champion power conversion efficiency (PCE) of 18.61% with JSC = 22.62 mA cm-2 , VOC = 1.02 V, and FF = 81.05% (an average one is 17.62%) is achieved with a thickness of ≈13 nm of DMZ (2 mg mL-1 ) under standard global AM 1.5 illumination, which is ≈1.5 times higher than that of devices based on poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT:PSS). More importantly, the devices based on DMZ exhibit a much better stability (90% of maximum PCE retained after more than 556 h in air (relative humidity ≈ 45%-50%) without any encapsulation) than that of devices based on PEDOT:PSS (only 36% of initial PCE retained after 77 h in same conditions). Therefore, the cost-effective and facile material named DMZ offers an appealing alternative to PEDOT:PSS or polytriarylamine for highly efficient and stable inverted planar PSCs.

6.
Int J Mol Sci ; 20(5)2019 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-30818864

RESUMEN

Paclitaxel (PTX) is one of the front-line drugs approved for the treatment of ovarian cancer. However, the application of PTX is limited due to the significant hydrophobicity and poor pharmacokinetics. We previously reported target-directed liposomes carrying tumor-selective conjugated antibody and encapsulated glycosylated PTX (gPTX-L) which successfully overcome the PTX limitation. The tubulin stabilizing activity of gPTX was equivalent to that of PTX while the cytotoxic activity of gPTX was reduced. In human ovarian cancer cell lines, SK-OV-3 and OVK18, the concentration at which cell growth was inhibited by 50% (IC50) for gPTX range from 15⁻20 nM, which was sensitive enough to address gPTX-L with tumor-selective antibody coupling for ovarian cancer therapy. The cell membrane receptor CD44 is associated with cancer progression and has been recognized as a cancer stem cell marker including ovarian cancer, becoming a suitable candidate to be targeted by gPTX-L therapy. In this study, gPTX-loading liposomes conjugated with anti-CD44 antibody (gPTX-IL) were assessed for the efficacy of targeting CD44-positive ovarian cancer cells. We successfully encapsulated gPTX into liposomes with the loading efficiency (LE) more than 80% in both of gPTX-L and gPTX-IL with a diameter of approximately 100 nm with efficacy of enhanced cytotoxicity in vitro and of convenient treatment in vivo. As the result, gPTX-IL efficiently suppressed tumor growth in vivo. Therefore gPTX-IL could be a promising formulation for effective ovarian cancer therapies.


Asunto(s)
Receptores de Hialuranos/metabolismo , Terapia Molecular Dirigida , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Paclitaxel/uso terapéutico , Anticuerpos Monoclonales/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Glicosilación , Humanos , Liposomas/ultraestructura , Neoplasias Ováricas/patología , Paclitaxel/farmacología
7.
Int J Mol Sci ; 19(11)2018 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-30373174

RESUMEN

Cripto-1 is a glycophosphatidylinositol (GPI) anchored signaling protein of epidermal growth factor (EGF)-Cripto-1-FRL1-Cryptic (CFC) family and plays a significant role in the early developmental stages and in the different types of cancer cells, epithelial to mesenchymal transition and tumor angiogenesis. Previously, we have developed cancer stem cells (miPS-LLCcm) from mouse iPSCs by culturing them in the presence of conditioned medium of Lewis Lung Carcinoma (LLC) cells for four weeks. Nodal and Cripto-1 were confirmed to be expressed in miPS-LLCcm cells by quantitative reverse transcription PCR (rt-qPCR) implying that Cr-1 was required in maintaining stemness. To investigate the biological effect of adding exogenous soluble CR-1 to the cancer stem cells, we have prepared a C-terminally truncated soluble form of recombinant human CR-1 protein (rhsfCR-1), in which the GPI anchored moiety was removed by substitution of a stop codon through site-directed mutagenesis. rhsfCR-1 effectively suppressed the proliferation and sphere forming ability of miPS-LLCcm cells in a dose-dependent manner in the range of 0 to 5 µg/mL, due to the suppression of Nodal-Cripto-1/ALK4/Smad2 signaling pathway. Frequency of sphere-forming cells was dropped from 1/40 to 1/69 by rhsfCR-1 at 1 µg/mL. Moreover, rhsfCR-1 in the range of 0 to 1 µg/mL also limited the differentiation of miPS-LLCcm cells into vascular endothelial cells probably due to the suppression of self-renewal, which should reduce the number of cells with stemness property. As demonstrated by a soluble form of exogenous Cripto-1 in this study, the efficient blockade would be an attractive way to study Cripto-1 dependent cancer stem cell properties for therapeutic application.


Asunto(s)
Autorrenovación de las Células , Proteínas Ligadas a GPI/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/citología , Animales , Diferenciación Celular , Línea Celular , Humanos , Ratones , Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , Proteínas Recombinantes/metabolismo , Transducción de Señal , Proteína Smad2/metabolismo
8.
Int J Mol Sci ; 19(3)2018 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-29495404

RESUMEN

We recently have established a successful xenograft model of human glioblastoma cells by enriching hyaluronic acid-dependent spheroid-forming populations termed U251MG-P1 cells from U251MG cells. Since U251MG-P1 cells have been confirmed to express CD44 along with principal stemness marker genes, OCT3/4, SOX2, KLF4 and Nanog, this CD44 expressing population appeared to majorly consist of undifferentiated cells. Evaluating the sensitivity to anti-cancer agents, we found U251MG-P1 cells were sensitive to doxorubicin with IC50 at 200 nM. Although doxorubicin has serious side-effects, establishment of an efficient therapy targeting undifferentiated glioblastoma cell population is necessary. We previously designed a chlorotoxin peptide fused to human IgG Fc region without hinge sequence (M-CTX-Fc), which exhibited a stronger growth inhibitory effect on the glioblastoma cell line A172 than an original chlorotoxin peptide. Combining these results together, we designed M-CTX-Fc conjugated liposomes encapsulating doxorubicin and used U251MG-P1 cells as the target model in this study. The liposome modified with M-CTX-Fc was designed with a diameter of approximately 100-150 nm and showed high encapsulation efficiency, adequate loading capacity of anticancer drug, enhanced antitumor effects demonstrating increasing uptake into the cells in vitro; M-CTX-Fc-L-Dox shows great promise in its ability to suppress tumor growth in vivo and it could serve as a template for targeted delivery of other therapeutics.


Asunto(s)
Doxorrubicina/análogos & derivados , Glioblastoma/genética , Receptores de Hialuranos/genética , Proteínas Recombinantes de Fusión , Venenos de Escorpión/farmacología , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Doxorrubicina/farmacología , Femenino , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Receptores de Hialuranos/metabolismo , Fragmentos Fc de Inmunoglobulinas , Inmunoglobulina G , Concentración 50 Inhibidora , Factor 4 Similar a Kruppel , Metaloproteinasa 2 de la Matriz , Ratones , Polietilenglicoles/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
9.
Nano Lett ; 14(5): 2764-71, 2014 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-24712578

RESUMEN

Solution processable semiconducting polymers with excellent film forming capacity and mechanical flexibility are considered among the most progressive alternatives to conventional inorganic semiconductors. However, the random packing of polymer chains and the disorder of the polymer matrix typically result in low charge transport mobilities (10(-5)-10(-2) cm(2) V(-1) s(-1)). These low mobilities compromise their performance and development. Here, we present a strategy, by utilizing capillary action, to mediate polymer chain self-assembly and unidirectional alignment on nanogrooved substrates. We designed a sandwich tunnel system separated by functionalized glass spacers to induce capillary action for controlling the polymer nanostructure, crystallinity, and charge transport. Using capillary action, we demonstrate saturation mobilities with average values of 21.3 and 18.5 cm(2) V(-1 )s(-1) on two different semiconducting polymers at a transistor channel length of 80 µm. These values are limited by the source-drain contact resistance, Rc. Using a longer channel length of 140 µm where the contact resistance is less important, we measured µh = 36.3 cm(2) v(-1) s(-1). Extrapolating to infinite channel length where Rc is unimportant, the intrinsic mobility for poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-alt-[1,2,5]thiadiazolo[3,4-c]pyridine] (Mn = 140 kDa) at this degree of chain alignment and structural order is µh ≈ 47 cm(2 )v(-1) s(-1). Our results create a promising pathway toward high performance, solution processable, and low-cost organic electronics.

10.
Opt Express ; 22 Suppl 6: A1412-21, 2014 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-25607298

RESUMEN

Microstructured porous zinc oxide (ZnO) thin film was developed and demonstrated as an electron selective layer for enhancing light scattering and efficiency in inverted organic photovoltaics. High degree of porosity was induced and controlled in the ZnO layer by incorporation of polyethylene glycol (PEG) organic template. Scanning electron microscopy, contact angle and absorption measurements prove that the ZnO:PEG ratio of 4:1 is optimal for the best performance of porous ZnO. Ensuring sufficient pore-filling, the use of porous ZnO leads to a marked improvement in device performance compared to non-porous ZnO, with 35% increase in current density and 30% increase in efficiency. Haze factor studies indicate that the performance improvement can be primarily attributed to the improved light scattering enabled by such a highly porous structure.


Asunto(s)
Suministros de Energía Eléctrica , Nanoestructuras/química , Polietilenglicoles/química , Refractometría/instrumentación , Óxido de Zinc/química , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Nanoporos/ultraestructura , Nanoestructuras/efectos de la radiación , Nanoestructuras/ultraestructura , Dispersión de Radiación , Semiconductores , Energía Solar , Óxido de Zinc/efectos de la radiación
11.
Nano Lett ; 13(8): 3796-801, 2013 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-23805897

RESUMEN

We demonstrate that the power conversion efficiency can be significantly improved in solution-processed small-molecule solar cells by tuning the thickness of the active layer and inserting an optical spacer (ZnO) between the active layer and the Al electrode. The enhancement in light absorption in the cell was measured with UV-vis absorption spectroscopy and by measurements of the photoinduced carriers generation rate. The ZnO layer used to improve the light-harvesting increases the charge collection efficiency, serves as a blocking layer for holes, and reduces the recombination rate. The combined optical and electrical improvements raise the power conversion efficiency of solution-processed small-molecule solar cells to 8.9%, that is, comparable to that of polymer counterparts.

12.
Small Methods ; : e2301387, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38470210

RESUMEN

The application of carbon nanotube (CNT) yarns as thermoelectric materials for harvesting energy from low-grade waste heat including that generated by the human body, is attracting considerable attention. However, the lack of efficient n-type CNT yarns hinders their practical implementation in thermoelectric devices. This study reports efficient n-doping of CNT yarns, employing 4-(1, 3-dimethyl-2, 3-dihydro-1H-benzimidazole-2-yl) phenyl) dimethylamine (N-DMBI) in alternative to conventional n-dopants, with o-dichlorobenzene emerging as the optimal solvent. The small molecular size of N-DMBI enables highly efficient doping within a remarkably short duration (10 s) while ensuring prolonged stability in air and at high temperature (150 °C). Furthermore, Joule annealing of the yarns significantly improves the n-doping efficiency. Consequently, thermoelectric power factors (PFs) of 2800, 2390, and 1534 µW m-1  K-2 are achieved at 200, 150, and 30 °C, respectively. The intercalation of N-DMBI molecules significantly suppresses the thermal conductivity, resulting in the high figure of merit (ZT) of 1.69×10-2 at 100 °C. Additionally, a π-type thermoelectric module is successfully demonstrated incorporating both p- and n-doped CNT yarns. This study offers an efficient doping strategy for achieving CNT yarns with high thermoelectric performance, contributing to the realization of lightweight and mechanically flexible CNT-based thermoelectric devices.

13.
Nanomicro Lett ; 16(1): 205, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38819522

RESUMEN

Metal halide perovskites, particularly the quasi-two-dimensional perovskite subclass, have exhibited considerable potential for next-generation electroluminescent materials for lighting and display. Nevertheless, the presence of defects within these perovskites has a substantial influence on the emission efficiency and durability of the devices. In this study, we revealed a synergistic passivation mechanism on perovskite films by using a dual-functional compound of potassium bromide. The dual functional potassium bromide on the one hand can passivate the defects of halide vacancies with bromine anions and, on the other hand, can screen the charged defects at the grain boundaries with potassium cations. This approach effectively reduces the probability of carriers quenching resulting from charged defects capture and consequently enhances the radiative recombination efficiency of perovskite thin films, leading to a significant enhancement of photoluminescence quantum yield to near-unity values (95%). Meanwhile, the potassium bromide treatment promoted the growth of homogeneous and smooth film, facilitating the charge carrier injection in the devices. Consequently, the perovskite light-emitting diodes based on this strategy achieve a maximum external quantum efficiency of ~ 21% and maximum luminance of ~ 60,000 cd m-2. This work provides a deeper insight into the passivation mechanism of ionic compound additives in perovskite with the solution method.

14.
Front Public Health ; 11: 1144642, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37124770

RESUMEN

Background: Preterm birth is a major public health concern with the largest burden of morbidity and mortality falling within low- and middle-income countries (LMIC). Materials and methods: This sequential explanatory mixed methods study was conducted in special care baby units (SCBUs) serving migrants and refugees along the Myanmar-Thailand border. It included a retrospective medical records review, qualitative interviews with mothers receiving care within SCBUs, and focus group discussions with health workers. Changes in neonatal mortality and four clinical outcomes were described. A mix of ethnographic phenomenology and implementation frameworks focused on cultural aspects, the lived experience of participants, and implementation outcomes related to SCBU care. Results: From 2008-2017, mortality was reduced by 68% and 53% in very (EGA 28-32 weeks) and moderate (EGA 33-36 weeks) preterm neonates, respectively. Median SCBU stay was longer in very compared to moderate preterm neonates: 35 (IQR 22, 48 days) vs. 10 days (IQR 5, 16). Duration of treatments was also longer in very preterm neonates: nasogastric feeding lasted 82% (IQR 74, 89) vs. 61% (IQR 40, 76) of the stay, and oxygen therapy was used a median of 14 (IQR 7, 27) vs. 2 (IQR 1, 6) days respectively. Nine interviews were conducted with mothers currently receiving care in the SCBU and four focus group discussions with a total of 27 local SCBU staff. Analysis corroborated quantitative analysis of newborn care services in this setting and incorporated pertinent implementation constructs including coverage, acceptability, appropriateness, feasibility, and fidelity. Coverage, acceptability, and appropriateness were often overlapping outcomes of interest highlighting financial issues prior to or while admitted to the SCBU and social issues and support systems adversely impacting SCBU stays. Interview and FGD findings highlight the barriers in this resource-limited setting as they impact the feasibility and fidelity of providing evidence-based SCBU care that often required adaptation to fit the financial and environmental constraints imposed by this setting. Discussion: This study provides an in-depth look at the nature of providing preterm neonatal interventions in a SCBU for a vulnerable population in a resource-limited setting. These findings support implementation of basic evidence-based interventions for preterm and newborn care globally, particularly in LMICs.


Asunto(s)
Nacimiento Prematuro , Refugiados , Migrantes , Femenino , Lactante , Humanos , Recién Nacido , Tailandia/epidemiología , Estudios Retrospectivos , Mianmar
15.
ACS Appl Mater Interfaces ; 15(38): 45177-45189, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37699120

RESUMEN

In this study, we investigated the impact of benzophenone (BP), a small molecule additive, on the performance and stability of inverted perovskite solar cells (PSCs). Specifically, we introduced BP into the perovskite precursor solution of FAPbI3 to fabricate PSCs with an ITO/PEDOT:PSS/BP:FAPbI3/PCBM/C60/PCB/Ag architecture. The incorporation of BP with an optimum concentration of 2 mg mL-1 significantly enhanced the power conversion efficiency (PCE) of the inverted PSC from 13.12 to 18.84% with negligible hysteresis. Notably, the BP-based PSCs retained ∼90% of their initial PCE after being stored in ambient air with 30% relative humidity at 25 °C for 700 h. In contrast, control devices showed rapid degradation, retaining only 30% of their initial value within 300 h under the same conditions. We attributed the superior performance and stability of the BP-based PSCs to the grain boundary passivation of the perovskite film. The improvement was mainly attributed to the intermolecular interaction between the O-donor Lewis base BP material and both Pb2+ and FA+ in FAPbI3. This effectively suppresses trap-assisted recombination and promotes the conversion of the δ-phase to photoactive and stable α-phase FAPbI3. Overall, our findings suggest that BP is a promising additive for improving the performance and stability of inverted PSCs.

16.
Nat Commun ; 14(1): 3571, 2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37322001

RESUMEN

To restrain the chemical reaction at cathode interface of organic solar cells, two cathode interfacial materials are synthesized by connecting phenanthroline with carbolong unit. Consequently, the D18:L8-BO based organic solar cell with double-phenanthroline-carbolong achieve the highest efficiency of 18.2%. Double-phenanthroline-carbolong with larger steric hindrance and stronger electron-withdrawing property confirms to suppress the interfacial reaction with norfullerene acceptor, resulting the most stable device. Double-phenanthroline-carbolong based device can sustain 80% of its initial efficiency for 2170 h in dark N2 atmosphere, 96 h under 85 oC and keep 68% initial efficiency after been illuminated for 2200 h, which are significantly better than bathocuproin based devices. Moreover, superb interfacial stability of double-phenanthroline-carbolong cathode interface enables thermal posttreatment of organic sub-cell in perovskite/organic tandem solar cells and obtained a remarkable efficiency of 21.7% with excellent thermal stability, which indicates the potentially wide application of phenanthroline-carbolong materials for stable and efficient solar device fabrications.


Asunto(s)
Atmósfera , Fenantrolinas , Electrodos , Electrones
17.
Front Public Health ; 10: 795503, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35530731

RESUMEN

In this paper, we describe the development of the film, "Under the Mask," which follows the lives of three fictional characters who live on the Thai-Myanmar border as they journey from diagnosis of tuberculosis (TB) to completion of treatment. Under the Mask was filmed on location on the Thai-Myanmar border by local filmmakers and former refugee populations. Cast members were chosen from communities living along the border. This paper describes the script development process, filming, and screening in the community. We also report the findings from the pre- and post-screening questionnaires and post-film focus group discussions. A total of 77 screening events took place between March 2019 and March 2020 to 9,510 audience members in community venues such as village squares, temples and monasteries (N = 21), schools/migrant learning centers (N = 49), and clinics (N = 4). The pre-and post-screen questionnaires showed a significant gain in self-perceived TB knowledge on prevention, transmission, signs and symptoms, and related discrimination. Our findings from 18 post-screening focus group discussions conducted with 188 participants showed that there were improvements in knowledge and awareness of the disease and treatment, as well as in the awareness of stigma, and the burdens of tuberculosis on patients and their families.


Asunto(s)
Migrantes , Tuberculosis , Humanos , Mianmar , Investigación Cualitativa , Tailandia/epidemiología , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Tuberculosis/prevención & control
18.
BMJ Open ; 12(12): e066529, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36523222

RESUMEN

OBJECTIVES: New point-of-care (POC) quantitative G6PD testing devices developed to provide safe radical cure for Plasmodium vivax malaria may be used to diagnose G6PD deficiency in newborns at risk of severe neonatal hyperbilirubinaemia, improving clinical care, and preventing related morbidity and mortality. METHODS: We conducted a mixed-methods study analysing technical performance and usability of the 'STANDARD G6PD' Biosensor when used by trained midwives on cord blood samples at two rural clinics on the Thailand-Myanmar border. RESULTS: In 307 cord blood samples, the Biosensor had a sensitivity of 1.000 (95% CI: 0.859 to 1.000) and a specificity of 0.993 (95% CI: 0.971 to 0.999) as compared with gold-standard spectrophotometry to diagnose G6PD-deficient newborns using a receiver operating characteristic (ROC) analysis-derived threshold of ≤4.8 IU/gHb. The Biosensor had a sensitivity of 0.727 (95% CI: 0.498 to 0.893) and specificity of 0.933 (95% CI: 0.876 to 0.969) for 30%-70% activity range in girls using ROC analysis-derived range of 4.9-9.9 IU/gHb. These thresholds allowed identification of all G6PD-deficient neonates and 80% of female neonates with intermediate phenotypes.Need of phototherapy treatment for neonatal hyperbilirubinaemia was higher in neonates with deficient and intermediate phenotypes as diagnosed by either reference spectrophotometry or Biosensor.Focus group discussions found high levels of learnability, willingness, satisfaction and suitability for the Biosensor in this setting. The staff valued the capacity of the Biosensor to identify newborns with G6PD deficiency early ('We can know that early, we can counsel the parents about the chances of their children getting jaundice') and at the POC, including in more rural settings ('Because we can know the right result of the G6PD deficiency in a short time, especially for the clinic which does not have a lab'). CONCLUSIONS: The Biosensor is a suitable tool in this resource-constrained setting to identify newborns with abnormal G6PD phenotypes at increased risk of neonatal hyperbilirubinaemia.


Asunto(s)
Deficiencia de Glucosafosfato Deshidrogenasa , Hiperbilirrubinemia Neonatal , Malaria Vivax , Oxibato de Sodio , Humanos , Recién Nacido , Femenino , Deficiencia de Glucosafosfato Deshidrogenasa/diagnóstico , Sangre Fetal , Oxibato de Sodio/uso terapéutico , Malaria Vivax/tratamiento farmacológico
19.
ACS Appl Mater Interfaces ; 14(21): 24374-24385, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35580336

RESUMEN

Fine-tuning the alkyl chains and end groups of non-fused ring electron acceptors (NFREAs) plays vital roles in the promotion of charge transfer (CT) and power conversion efficiency (PCE). In this work, we developed a series of A-D-A'-D-A-type NFREAs, which possess the same terminals (A), the cyclopentadithiophene unit (D), and the thieno[3,4-c]pyrrole-4,6-dione (A'). Despite the subtle difference in side chains and halogenated end groups, the six acceptors exhibit a considerable difference in the efficiency and device stability of the organic solar cells (OSCs). Among the molecules, chlorinated NFREAs show a broader light absorption than the fluorinated ones do. Compared with C8C8-4F (1-octylnonyl and fluorination) and C6C4-4Cl (2-butyloctyl and chlorination), C8C8-4Cl (1-octylnonyl and chlorination) exhibits a lower highest occupied molecular orbital level, higher electron mobility, and denser molecular packing. The OSCs based on PM6:C8C8-4Cl yield the best PCE of 14.11%, which is attributed to the faster charge transport, high miscibility, and preferable morphology. Moreover, the PM6:C8C8-4Cl devices retain 91.1% of the initial PCE after being placed in air with 67% relative humidity for 50 days. This work shows that the simultaneous optimization of side chains and end groups facilitates the CT and improves the stability in the OSCs, offering a novel view into the molecular design of A-D-A'-D-A-type NFREAs.

20.
Adv Sci (Weinh) ; 9(28): e2200445, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35876031

RESUMEN

Organic solar cells (OSCs) based on polymer donor and non-fullerene acceptor achieve power conversion efficiency (PCE) more than 19% but their poor absorption below 550 nm restricts the harvesting of high-energy photons. In contrast, wide bandgap all-inorganic perovskites limit the absorption of low-energy photons and cause serious below bandgap loss. Therefore, a 2-terminal (2T) monolithic perovskite/organic tandem solar cell (TSC) incorporating wide bandgap CsPbI2 Br is demonstrated as front cell absorber and organic PM6:Y6 blend as rear cell absorber, to extend the absorption of OSCs into high-energy photon region. The perovskite sub-cell, featuring a sol-gel prepared ZnO/SnO2 bilayer electron transporting layer, renders a high open-circuit voltage (VOC ). The VOC is further enhanced by employing thermal annealing (TA)-free process in the fabrication of rear sub-cell, demonstrating a record high VOC of 2.116 V. The TA-free Ag/PFN-Br interface in organic sub-cell facilitates charge transport and restrains nonradiative recombination. Consequently, a remarkable PCE of 20.6% is achieved in monolithic 2T-TSCs configuration, which is higher than that of both reported single junction and tandem OSCs, demonstrating that tandem with wide bandgap all-inorganic perovskite is a promising strategy to improve the efficiency of OSCs.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA