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1.
Chem Rev ; 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36728153

RESUMO

Ionizing radiation such as X-rays and γ-rays has been extensively studied and used in various fields such as medical imaging, radiographic nondestructive testing, nuclear defense, homeland security, and scientific research. Therefore, the detection of such high-energy radiation with high-sensitivity and low-cost-based materials and devices is highly important and desirable. Halide perovskites have emerged as promising candidates for radiation detection due to the large light absorption coefficient, large resistivity, low leakage current, high mobility, and simplicity in synthesis and processing as compared with commercial silicon (Si) and amorphous selenium (a-Se). In this review, we provide an extensive overview of current progress in terms of materials development and corresponding device architectures for radiation detection. We discuss the properties of a plethora of reported compounds involving organic-inorganic hybrid, all-inorganic, all-organic perovskite and antiperovskite structures, as well as the continuous breakthroughs in device architectures, performance, and environmental stability. We focus on the critical advancements of the field in the past few years and we provide valuable insight for the development of next-generation materials and devices for radiation detection and imaging applications.

2.
Inorg Chem ; 62(49): 20142-20152, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38009949

RESUMO

Chiral hybrid metal-halide semiconductors (MHS) pose as ideal candidates for spintronic applications owing to their strong spin-orbit coupling (SOC), and long spin relaxation times. Shedding light on the underlying structure-property relationships is of paramount importance for the targeted synthesis of materials with an optimum performance. Herein, we report the synthesis and optical properties of 1D chiral (R-/S-THBTD)SbBr5 (THBTD = 4,5,6,7-tetrahydro-benzothiazole-2,6-diamine) semiconductors using a multifunctional ligand as a countercation and a structure directing agent. (R-/S-THBTD)SbBr5 feature direct and indirect band gap characteristics, exhibiting photoluminescence (PL) light emission at RT that is accompanied by a lifetime of a few ns. Circular dichroism (CD), second harmonic generation (SHG), and piezoresponse force microscopy (PFM) studies validate the chiral nature of the synthesized materials. Density functional theory (DFT) calculations revealed a Rashba/Dresselhaus (R/D) spin splitting, supported by an energy splitting (ER) of 23 and 25 meV, and a Rashba parameter (αR) of 0.23 and 0.32 eV·Å for the R and S analogs, respectively. These values are comparable to those of the 3D and 2D perovskite materials. Notably, (S-THBTD)SbBr5 has been air-stable for a year, a record performance among chiral lead-free MHS. This work demonstrates that low-dimensional, lead-free, chiral semiconductors with exceptional air stability can be acquired, without compromising spin splitting and manipulation performance.

3.
J Chem Phys ; 159(5)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37530110

RESUMO

In this work, we investigated the effect of hole transporting poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) interfacing with Mn-doped CdS/ZnS quantum dots (QDs) deposited on an indium tin oxide (ITO) substrate on the photoemission of upconverted hot electrons under weak continuous wave photoexcitation in a vacuum. Among the various factors that can influence the photoemission of the upconverted hot electrons, we studied the role of PEDOT:PSS in facilitating the hole transfer from QDs and altering the energy of photoemitted hot electrons. Compared to hot electrons emitted from QDs deposited directly on the ITO substrate, the addition of the PEDOT:PSS layer between the QD and ITO layers increased the energy of the photoemitted hot electrons. The increased energy of the photoemitted hot electrons is attributed in part to the reduced steady-state positive charge on the QDs under continuous photoexcitation, which reduces the energy required to eject the electron from the conduction band.

4.
J Nanobiotechnology ; 21(1): 456, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38017573

RESUMO

Traditional Chinese Medicines (TCMs) have been used for centuries for the treatment and management of various diseases. However, their effective delivery to targeted sites may be a major challenge due to their poor water solubility, low bioavailability, and potential toxicity. Nanocarriers, such as liposomes, polymeric nanoparticles, inorganic nanoparticles and organic/inorganic nanohybrids based on active constituents from TCMs have been extensively studied as a promising strategy to improve the delivery of active constituents from TCMs to achieve a higher therapeutic effect with fewer side effects compared to conventional formulations. This review summarizes the recent advances in nanocarrier-based delivery systems for various types of active constituents of TCMs, including terpenoids, polyphenols, alkaloids, flavonoids, and quinones, from different natural sources. This review covers the design and preparation of nanocarriers, their characterization, and in vitro/vivo evaluations. Additionally, this review highlights the challenges and opportunities in the field and suggests future directions for research. Nanocarrier-based delivery systems have shown great potential in improving the therapeutic efficacy of TCMs, and this review may serve as a comprehensive resource to researchers in this field.


Assuntos
Medicamentos de Ervas Chinesas , Nanopartículas , Medicamentos de Ervas Chinesas/farmacologia , Medicina Tradicional Chinesa , Disponibilidade Biológica , Nanotecnologia , Sistemas de Liberação de Medicamentos
5.
J Am Chem Soc ; 144(14): 6390-6409, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35378979

RESUMO

The nature of the organic cation in two-dimensional (2D) hybrid lead iodide perovskites tailors the structural and technological features of the resultant material. Herein, we present three new homologous series of (100) lead iodide perovskites with the organic cations allylammonium (AA) containing an unsaturated C═C group and iodopropylammonium (IdPA) containing iodine on the organic chain: (AA)2MAn-1PbnI3n+1 (n = 3-4), [(AA)x(IdPA)1-x]2MAn-1PbnI3n+1 (n = 1-4), and (IdPA)2MAn-1PbnI3n+1 (n = 1-4), as well as their perovskite-related substructures. We report the in situ transformation of AA organic layers into IdPA and the incorporation of these cations simultaneously into the 2D perovskite structure. Single-crystal X-ray diffraction shows that (AA)2MA2Pb3I10 crystallizes in the space group P21/c with a unique inorganic layer offset (0, <1/2), comprising the first example of n = 3 halide perovskite with a monoammonium cation that deviates from the Ruddlesden-Popper (RP) halide structure type. (IdPA)2MA2Pb3I10 and the alloyed [(AA)x(IdPA)1-x]2MA2Pb3I10 crystallize in the RP structure, both in space group P21/c. The adjacent I···I interlayer distance in (AA)2MA2Pb3I10 is ∼5.6 Å, drawing the [Pb3I10]4- layers closer together among all reported n = 3 RP lead iodides. (AA)2MA2Pb3I10 presents band-edge absorption and photoluminescence (PL) emission at around 2.0 eV that is slightly red-shifted in comparison to (IdPA)2MA2Pb3I10. The band structure calculations suggest that both (AA)2MA2Pb3I10 and (IdPA)2MA2Pb3I10 have in-plane effective masses around 0.04m0 and 0.08m0, respectively. IdPA cations have a greater dielectric contribution than AA. The excited-state dynamics investigated by transient absorption (TA) spectroscopy reveal a long-lived (∼100 ps) trap state ensemble with broad-band emission; our evidence suggests that these states appear due to lattice distortions induced by the incorporation of IdPA cations.

6.
J Am Chem Soc ; 142(13): 6180-6187, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32017550

RESUMO

The efficient preparation of single-crystalline ionic polymers and fundamental understanding of their structure-property relationships at the molecular level remains a challenge in chemistry and materials science. Here, we describe the single-crystal structure of a highly ordered polycationic polymer (polyelectrolyte) and its proton conductivity. The polyelectrolyte single crystals can be prepared on a gram-scale in quantitative yield, by taking advantage of an ultraviolet/sunlight-induced topochemical polymerization, from a tricationic monomer-a self-complementary building block possessing a preorganized conformation. A single-crystal-to-single-crystal photopolymerization was revealed unambiguously by in situ single-crystal X-ray diffraction analysis, which was also employed to follow the progression of molecular structure from the monomer, to a partially polymerized intermediate, and, finally, to the polymer itself. Collinear polymer chains are held together tightly by multiple Coulombic interactions involving counterions to form two-dimensional lamellar sheets (1 nm in height) with sub-nanometer pores (5 Å). The polymer is extremely stable under 254 nm light irradiation and high temperature (above 500 K). The extraordinary mechanical strength and environmental stability-in combination with its impressive proton conductivity (∼3 × 10-4 S cm-1)-endow the polymer with potential applications as a robust proton-conducting material. By marrying supramolecular chemistry with macromolecular science, the outcome represents a major step toward the controlled synthesis of single-crystalline polyelectrolyte materials with perfect tacticity.

7.
Aging Clin Exp Res ; 32(2): 329-337, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30993660

RESUMO

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common complication after orthopedic surgery, which is not conducive to the prognosis of the elderly. AIMS: We performed this study to investigate the effects of oxycodone applied for patient-controlled intravenous analgesia (PCIA) on postoperative cognitive function in elderly patients after total hip arthroplasty (THA). METHODS: Ninety-nine participants were enrolled and allocated into two groups: oxycodone group (group O) and sufentanil group (group S). The primary outcome was the incidence of POCD, diagnosed according to the changes in the Mini-mental status examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. The secondary outcomes included the plasma levels of S-100B protein and neuron-specific enolase (NSE), the amount of postoperative analgesic consumption and the incidence of adverse reactions. RESULTS: The incidence of POCD was significantly lower in patients receiving oxycodone up to the 3rd postoperative day (POD, 1st POD 27.3% vs. 51.1%, P = 0.021; 3rd POD 20.5% vs. 40.0%, P = 0.045), as compared to patients receiving sufentanil. The MMSE and MoCA scores of both groups decreased to varying degrees. However, compared with group S, the MMSE scores at 1st POD, 3rd POD, 5th POD and 7st POD in group O were higher than that in group S, while MoCA scores at 1st POD, 3rd POD and 5th POD in group O were higher. Compared with group S, the plasma levels of S-100B protein in group O at 4 h, 8 h, 12 h post-surgery were lower. While the plasma levels of NSE in group O at 4 h, 8 h, 12 h, 24 h post-surgery were lower. Number of PCIA boluses and consumption of analgesic drug during the first two POD were similar between two groups. However, postoperative incidence of nausea, vomiting and pruritus was significantly lower in patients receiving oxycodone. CONCLUSION: Oxycodone applied for PCIA in elderly patients after THA could reduce the incidence of POCD, improve postoperative cognitive function and decrease the adverse reactions.


Assuntos
Analgésicos Opioides/uso terapêutico , Artroplastia de Quadril , Cognição , Oxicodona/uso terapêutico , Idoso , Analgesia Controlada pelo Paciente , Analgésicos Opioides/efeitos adversos , Artroplastia de Quadril/efeitos adversos , Humanos , Pessoa de Meia-Idade , Oxicodona/efeitos adversos , Dor Pós-Operatória/prevenção & controle , Período Pós-Operatório , Sufentanil/efeitos adversos , Sufentanil/uso terapêutico
8.
J Am Chem Soc ; 141(21): 8627-8637, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31063361

RESUMO

The power conversion efficiency (PCE) of halide perovskite solar cells is now comparable to that of commercial solar cells. These solar cells are generally based on multication mixed-halide perovskite absorbers with nonideal band gaps of 1.5-1.6 eV. The PCE should be able to rise further if the solar cells could use narrower-band gap absorbers (1.2-1.4 eV). Reducing the Pb content of the semiconductors without sacrificing performance is also a significant driver in the perovskite solar cell research. Here, we demonstrate that mixed Pb/Sn-based perovskites containing the oversized ethylenediammonium ( en) dication, { en}FA0.5MA0.5Sn0.5Pb0.5I3 (FA = formamidinium, MA = methylammonium), can exhibit ideal band gaps of 1.27-1.38 eV, suitable for the assembly of single-junction solar cells with higher efficiencies. The use of en dication creates a three-dimensional (3D) hollow inorganic perovskite structure, which was verified through crystal density measurements and single-crystal X-ray diffraction structural analysis as well as nuclear magnetic resonance measurements. The { en}FA0.5MA0.5Sn0.5Pb0.5I3 structure has massive Pb/Sn vacancies and much higher chemical stability than the same structure without en and vacancies. This new property reduces the dark current and carrier trap density and increases the carrier lifetime of the Pb/Sn-based perovskite films. Therefore, solar cells using { en}FA0.5MA0.5Sn0.5Pb0.5I3 light absorbers have substantially enhanced air stability and around 20% improvement in efficiency. After overlaying a thin MABr top layer, we found that the {5% en}FA0.5MA0.5Sn0.5Pb0.5I3 material gives an optimized PCE of 17.04%. The results highlight the strong promise of 3D hollow mixed Pb/Sn perovskites in achieving ideal band gap materials with higher chemical stability and lower Pb content for high-performance single-junction solar cells or multijunction solar cells serving as bottom cells.

9.
J Am Chem Soc ; 141(13): 5518-5534, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30827098

RESUMO

The unique hybrid nature of 2D Ruddlesden-Popper (R-P) perovskites has bestowed upon them not only tunability of their electronic properties but also high-performance electronic devices with improved environmental stability as compared to their 3D analogs. However, there is limited information about their inherent heat, light, and air stability and how different parameters such as the inorganic layer number and length of organic spacer molecule affect stability. To gain deeper understanding on the matter we have expanded the family of 2D R-P perovskites, by utilizing pentylamine (PA)2(MA) n-1Pb nI3 n+1 ( n = 1-5, PA = CH3(CH2)4NH3+, C5) and hexylamine (HA)2(MA) n-1Pb nI3 n+1 ( n = 1-4, HA = CH3(CH2)5NH3+, C6) as the organic spacer molecules between the inorganic slabs, creating two new series of layered materials, for up to n = 5 and 4 layers, respectively. The resulting compounds were extensively characterized through a combination of physical and spectroscopic methods, including single crystal X-ray analysis. High resolution powder X-ray diffraction studies using synchrotron radiation shed light for the first time to the phase transitions of the higher layer 2D R-P perovskites. The increase in the length of the organic spacer molecules did not affect their optical properties; however, it has a pronounced effect on the air, heat, and light stability of the fabricated thin films. An extensive study of heat, light, and air stability with and without encapsulation revealed that specific compounds can be air stable (relative humidity (RH) = 20-80% ± 5%) for more than 450 days, while heat and light stability in air can be exponentially increased by encapsulating the corresponding films. Evaluation of the out-of-plane mechanical properties of the corresponding materials showed that their soft and flexible nature can be compared to current commercially available polymer substrates (e.g., PMMA), rendering them suitable for fabricating flexible and wearable electronic devices.

10.
Biomacromolecules ; 19(2): 298-306, 2018 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-29195275

RESUMO

A powerful tool for controlling interfacial properties and molecular architecture relies on the tailored adsorption of stimuli-responsive block copolymers onto surfaces. Here, we use computational and experimental approaches to investigate the adsorption behavior of thermally responsive polypeptide block copolymers (elastin-like polypeptides, ELPs) onto silica surfaces, and to explore the effects of surface affinity and micellization on the adsorption kinetics and the resultant polypeptide layers. We demonstrate that genetic incorporation of a silica-binding peptide (silaffin R5) results in enhanced adsorption of these block copolymers onto silica surfaces as measured by quartz crystal microbalance and ellipsometry. We find that the silaffin peptide can also direct micelle adsorption, leading to close-packed micellar arrangements that are distinct from the sparse, patchy arrangements observed for ELP micelles lacking a silaffin tag, as evidenced by atomic force microscopy measurements. These experimental findings are consistent with results of dissipative particle dynamics simulations. Wettability measurements suggest that surface immobilization hampers the temperature-dependent conformational change of ELP micelles, while adsorbed ELP unimers (i.e., unmicellized block copolymers) retain their thermally responsive property at interfaces. These observations provide guidance on the use of ELP block copolymers as building blocks for fabricating smart surfaces and interfaces with programmable architecture and functionality.


Assuntos
Elastina/química , Micelas , Fragmentos de Peptídeos/química , Precursores de Proteínas/química , Dióxido de Silício/química , Adsorção , Simulação de Dinâmica Molecular , Molhabilidade
11.
Biofouling ; 34(6): 595-604, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29897277

RESUMO

Candida albicans is a leading cause of catheter-associated urinary tract infections and elimination of these biofilm-based infections without antifungal agents would constitute a significant medical advance. A novel urinary catheter prototype that utilizes on-demand surface deformation is effective at eliminating bacterial biofilms and here the broader applicability of this prototype to remove fungal biofilms has been demonstrated. C. albicans biofilms were debonded from prototypes by selectively inflating four additional intralumens surrounding the main lumen of the catheters to provide the necessary surface strain to remove the adhered biofilm. Deformable catheters eliminated significantly more biofilm than the controls (>90% eliminated vs 10% control; p < 0.001). Mechanical testing revealed that fungal biofilms have an elastic modulus of 45 ± 6.7 kPa with a fracture energy of 0.4-2 J m-2. This study underscores the potential of mechanical disruption as a materials design strategy to combat fungal device-associated infections.


Assuntos
Biofilmes , Candida albicans/fisiologia , Cateteres Urinários/microbiologia , Módulo de Elasticidade , Humanos
12.
Inorg Chem ; 56(15): 9291-9302, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28749133

RESUMO

A series of two-dimensional (2D) hybrid organic-inorganic perovskite (HOIP) crystals, based on acene alkylamine cations (i.e., phenylmethylammonium (PMA), 2-phenylethylammonium (PEA), 1-(2-naphthyl)methanammonium (NMA), and 2-(2-naphthyl)ethanammonium (NEA)) and lead(II) halide (i.e., PbX42-, X = Cl, Br, and I) frameworks, and their corresponding thin films were fabricated and examined for structure-property relationship. Several new or redetermined crystal structures are reported, including those for (NEA)2PbI4, (NEA)2PbBr4, (NMA)2PbBr4, (PMA)2PbBr4, and (PEA)2PbI4. Non-centrosymmetric structures from among these 2D HOIPs were confirmed by piezoresponse force microscopy-especially noteworthy is the structure of (PMA)2PbBr4, which was previously reported as centrosymmetric. Examination of the impact of organic cation and inorganic layer choice on the exciton absorption/emission properties, among the set of compounds considered, reveals that perovskite layer distortion (i.e., Pb-I-Pb bond angle between adjacent PbI6 octahedra) has a more global effect on the exciton properties than octahedral distortion (i.e., variation of I-Pb-I bond angles and discrepancy among Pb-I bond lengths within each PbI6 octahedron). In addition to the characteristic sharp exciton emission for each perovskite, (PMA)2PbCl4, (PEA)2PbCl4, (NMA)2PbCl4, and (PMA)2PbBr4 exhibit separate, broad "white" emission in the long wavelength range. Piezoelectric compounds identified from these 2D HOIPs may be considered for future piezoresponse-type energy or electronic applications.

13.
Nat Mater ; 12(4): 321-5, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23334002

RESUMO

Crumpled graphene films are widely used, for instance in electronics, energy storage, composites and biomedicine. Although it is known that the degree of crumpling affects graphene's properties and the performance of graphene-based devices and materials, the controlled folding and unfolding of crumpled graphene films has not been demonstrated. Here we report an approach to reversibly control the crumpling and unfolding of large-area graphene sheets. We show with experiments, atomistic simulations and theory that, by harnessing the mechanical instabilities of graphene adhered on a biaxially pre-stretched polymer substrate and by controlling the relaxation of the pre-strains in a particular order, graphene films can be crumpled into tailored self-organized hierarchical structures that mimic superhydrophobic leaves. The approach enables us to fabricate large-area conductive coatings and electrodes showing superhydrophobicity, high transparency, and tunable wettability and transmittance. We also demonstrate that crumpled graphene-polymer laminates can be used as artificial-muscle actuators.


Assuntos
Grafite/química , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanotecnologia , Tamanho da Partícula , Propriedades de Superfície
14.
Nanotechnology ; 25(44): 445703, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25302928

RESUMO

Contact resonance AFM (CR-AFM) is a scanning probe microscopy technique that utilizes the contact resonances of the AFM cantilever for concurrent imaging of topography and surface stiffness. The technique has not been used in liquid until recently due to analytical and experimental difficulties, associated with viscous damping of cantilever vibrations and fluid loading effects. To address these difficulties, (i) an analytical approach for contact resonances in liquid is developed, and (ii) direct excitation of the contact resonances is demonstrated by actuating the cantilever directly in a magnetic field. By implementing the analytical approach and the direct actuation through magnetic particles, quantitative stiffness imaging on surfaces with a wide range of stiffness can be achieved in liquid with soft cantilevers and low contact forces.

15.
Wei Sheng Wu Xue Bao ; 54(4): 424-32, 2014 Apr 04.
Artigo em Zh | MEDLINE | ID: mdl-25007655

RESUMO

OBJECTIVE: We investigated biological activities, physiological and biochemical properties of two endophytic bacteria isolated from fresh leaves of tea plants. METHOD: We did morphological observation, biological activity test, physiological and biochemical assays, 16S rDNA analysis, and compared their genotype and phenotype with those of 13 Herbaspirillum species. RESULTS: Their colonies were round, opaque, central uplift and regular edge with a milky white color. Their cells were Gram-negative, rod-shaped with the size of (0.5-0.7) mm x (1.4-1.8) mm and flagellers, but without spore. Both isolates produced indole-3-acetic acid (IAA) (18.7 mg/L for WT00C and 24.9 mg/L for WT00F), ammonia and siderophores, but no nitrogen-fixing activity. The 16S rDNA had sequences similarities of 99.7% each other and 99% with 13 Herbaspirillum species. Two isolates used carbon source as described in the genus Herbaspirillum, except for propionate salt. The neighbor-joining tree built using the 16S rDNA showed that two isolates formed an independent group, which kept certain genetic distance from the 13 Herbaspirillum species. Their physiological and biochemical characteristics and genotypes were different from those for 13 Herbaspirillum species. CONCLUSION: Two isolates WT00C and WT00F were classified as novel members in the genus Herbaspirillum.


Assuntos
Camellia sinensis/microbiologia , Endófitos/isolamento & purificação , Herbaspirillum/isolamento & purificação , DNA Bacteriano/genética , Endófitos/classificação , Endófitos/genética , Endófitos/metabolismo , Herbaspirillum/classificação , Herbaspirillum/genética , Herbaspirillum/metabolismo , Ácidos Indolacéticos/metabolismo , Dados de Sequência Molecular , Filogenia
16.
ACS Nano ; 18(22): 14218-14230, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38787298

RESUMO

Device-level implementation of soft materials for energy conversion and thermal management demands a comprehensive understanding of their thermal conductivity and elastic modulus to mitigate thermo-mechanical challenges and ensure long-term stability. Thermal conductivity and elastic modulus are usually positively correlated in soft materials, such as amorphous macromolecules, which poses a challenge to discover materials that are either soft and thermally conductive or hard and thermally insulative. Here, we show anomalous correlations of thermal conductivity and elastic modulus in two-dimensional (2D) hybrid organic-inorganic perovskites (HOIP) by engineering the molecular interactions between organic cations. By replacing conventional alkyl-alkyl and aryl-aryl type organic interactions with mixed alkyl-aryl interactions, we observe an enhancement in elastic modulus with a reduction in thermal conductivity. This anomalous dependence provides a route to engineer thermal conductivity and elastic modulus independently and a guideline to search for better thermal management materials. Further, introducing chirality into the organic cation induces a molecular packing that leads to the same thermal conductivity and elastic modulus regardless of the composition across all half-chiral 2D HOIPs. This finding provides substantial leeway for further investigations in chiral 2D HOIPs to tune optoelectronic properties without compromising thermal and mechanical stability.

17.
ACS Appl Mater Interfaces ; 15(6): 7919-7927, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36740778

RESUMO

The implementation of two-dimensional (2D) hybrid organic-inorganic perovskites (HOIPs) in semiconductor device applications will have to accommodate the co-existence of strain and temperature stressors and requires a thorough understanding of the thermomechanical behavior of 2D HOIPs. This will mitigate thermomechanical stability issues and improve the durability of the devices, especially when one considers the high susceptibility of 2D HOIPs to temperature due to their soft nature. Here, we employ atomic force microscopy (AFM) stretching of suspended membranes to measure the temperature dependence of the in-plane Young's modulus (E∥) of model Ruddlesden-Popper 2D HOIPs with a general formula of (CH3(CH2)3NH3)2(CH3NH3)n-1PbnI3n+1 (here, n = 1, 3, or 5). We find that E∥ values of these 2D HOIPs exhibit a prominent non-monotonic dependence on temperature, particularly an abnormal thermal stiffening behavior (nearly 40% change in E∥) starting around the order-disorder transition temperature of the butylammonium spacer molecules, which is significantly different from the thermomechanical behavior expected from their 3D counterpart (CH3NH3PbI3) or other low-dimensional material systems. Further raising the temperature eventually reverses the trend to thermal softening. The magnitude of the thermally induced change in E∥ is also much higher in 2D HOIPs than in their 3D analogs. Our results can shed light on the structural origin of the thermomechanical behavior and provide needed guidance to design 2D HOIPs with desired thermomechanical properties to meet the application needs.

18.
Heliyon ; 9(6): e16213, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37274687

RESUMO

Objective: The purpose of this study was to evaluate the efficacy and safety of Zishen Yutai Pill combined with western medicine for the treatment of women with threatened miscarriage during the first trimester of pregnancy. Methods: Randomized controlled trials published before the end of Apr 1, 2023 on Zishen Yutai Pill and threatened miscarriage were systematically retrieved from China National Knowledge Infrastructure, Wanfang, Sinomed, VIP, PubMed, EMBASE, Web of Science and the Cochrane Library. The international clinical trial registration platform and the Chinese clinical trial registration platform of clinical trials was searched from their inception until Apr 1, 2023. Meta analysis of random effect model was used to combine the research data. Chi-squared test and I2 statistics were used for heterogeneity test. Results: Twenty-three trials (enrolling 2411 participants) were included in the review. Zishen Yutai pill combined with western medicine therapy showed significant improvement on human chorionic gonadotropin [MD 19.33 IU/ml, 95% CI (15.84, 22.81)], the total effective rate [RR 1.19, 95% CI (1.15-1.23)], progesterone [MD 7.14 ng/ml, 95% CI (6.14, 8.13)], estradiol [MD 33.69 pg/ml, 95% CI (27.42, 39.96)], duration of abdominal pain [MD -2.36 d, 95% CI (- 3.54, - 1.18)], duration of vaginal bleeding [MD -1.94 d, 95% CI (- 2.93, - 0.94)], and fibrinogen [MD -0.34 g/L, 95% CI (- 0.57, - 0.11)]. There was no significant difference in hematocrit [MD 0.68%, 95% CI (- 0.08, 1.44)] between the experimental and the control group. Zishen Yutai Pill may improve the clinical symptoms in women with threatened miscarriage, such as human chorionic gonadotropin the total effective rate, progesterone, estradiol, duration of abdominal pain, duration of vaginal bleeding, and fibrinogen. Especially for progesterone, the effect of treatment ≦2 weeks is significantly better than treatment of >2 weeks. For estradiol, the effect of treatment >2 weeks is significantly better than treatment of ≦ 2 weeks. Conclusion: Zishen Yutai Pill, as a complementary therapy, significantly improved human chorionic gonadotropin, the total effective rate, progesterone, estradiol, abdominal pain, vaginal bleeding, and fibrinogen in patients with threatened miscarriage in first-trimester pregnancy. However, the systematic review has some limitations, such as degraded information quality, no blinding of patients or doctors, etc. Due to the small sample size and low quality of research, it needs to be further confirmed by large sample and high-quality randomized controlled trials, such as blinding of patients, doctors and outcome assessment should be complemented, clinical follow-up, live birth rate, fetal growth should be supplemented. Systematic review registration: INPLASY202320039.

19.
Front Immunol ; 14: 1146612, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37051243

RESUMO

Background: Neutrophil extracellular traps (NETs) can cause acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by inducing macrophage pyroptosis. The purpose of this study was to find out whether pretreatment of alpha-linolenic acid (ALA) could inhibit NETs-induced macrophage pyroptosis in sepsis-induced ALI/ARDS, as well as to identify which inflammasome is involved in this process. Methods: LPS was instilled into the trachea to establish sepsis-induced ALI/ARDS in a mouse model. ​Lung injury was assessed by microscopic examination of lung tissue after hematoxylin and eosin staining, pathology score, and bronchoalveolar lavage fluid (BALF) total protein concentration. The level of NETs in lung tissue was detected by MPO-DNA ELISA. Purified NETs, extracted from peritoneal neutrophils, induced macrophage pyroptosis in vitro. Expression of pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC) and IL-1ß in the lung tissue and bone marrow-derived macrophages (BMDMs) were determined by western blotting or ELISA. Specks of Pyrin/ASC were examined by confocal immunofluorescence microscopy. Mefv (Pyrin)-/- mice were used to study the role of Pyrin in the process of sepsis-induced ALI/ARDS. Results: ALA alleviated LPS-induced lung injury. ALA reduced the level of NETs, pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC), and IL-1ß in the lung tissue of sepsis mice. In vitro, NETs increased the expression of pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC) and IL-1ß significantly in BMDMs. Pyrin protein was found to be higher and form the inflammasome with ASC in NETs challenged-BMDMs. Knockout of Mefv (Pyrin) gene fully restored the increased expression of pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC) and IL-1ß in vitro and in vivo. Lung injury was alleviated significantly in Mefv (Pyrin)-/- mice as well.​ ALA suppresses all the NETs-induced changes as mentioned above. Conclusion: Our study is the first to demonstrate Pyrin inflammasome driving NETs-induced macrophage pyroptosis, and ALA may reduce ALI/ARDS by inhibiting the activation of the Pyrin inflammasome-driven macrophage pyroptosis.


Assuntos
Lesão Pulmonar Aguda , Armadilhas Extracelulares , Síndrome do Desconforto Respiratório , Sepse , Animais , Camundongos , Inflamassomos/metabolismo , Macrófagos Alveolares/metabolismo , Pirina , Ácido alfa-Linolênico , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Armadilhas Extracelulares/metabolismo , Piroptose , Lipopolissacarídeos/farmacologia , Lesão Pulmonar Aguda/metabolismo , Camundongos Knockout , Síndrome do Desconforto Respiratório/patologia , Sepse/complicações , Sepse/patologia , Caspases
20.
Adv Sci (Weinh) ; 10(26): e2303133, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37414727

RESUMO

2D hybrid organic-inorganic perovskites (HOIPs) are commonly found under subcritical cyclic stresses and suffer from fatigue issues during device operation. However, their fatigue properties remain unknown. Here, the fatigue behavior of (C4 H9 -NH3 )2 (CH3 NH3 )2 Pb3 I10 , the archetype 2D HOIP, is systematically investigated by atomic force microscopy (AFM). It is found that 2D HOIPs are much more fatigue resilient than polymers and can survive over 1 billion cycles. 2D HOIPs tend to exhibit brittle failure at high mean stress levels, but behave as ductile materials at low mean stress levels. These results suggest the presence of a plastic deformation mechanism in these ionic 2D HOIPs at low mean stress levels, which may contribute to the long fatigue lifetime, but is inhibited at higher mean stresses. The stiffness and strength of 2D HOIPs are gradually weakened under subcritical loading, potentially as a result of stress-induced defect nucleation and accumulation. The cyclic loading component can further accelerate this process. The fatigue lifetime of 2D HOIPs can be extended by reducing the mean stress, stress amplitude, or increasing the thickness. These results can provide indispensable insights into designing and engineering 2D HOIPs and other hybrid organic-inorganic materials for long-term mechanical durability.

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