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1.
Bioact Mater ; 43: 67-81, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39328776

RESUMO

Current cancer immunotherapies exhibit low response rates attributed to suppressive tumor immune microenvironments (TIMEs). To address these unfavorable TIMEs, supplementation with tumor-associated antigens and stimulation of immune cells at target sites are indispensable for eliciting anti-tumoral immune responses. Previous research has explored the induction of immunotherapy through multiple injections and implants; however, these approaches lack consideration for patient convenience and the implementation of finely tunable immune response control systems to mitigate the side effects of over-inflammatory responses, such as cytokine storms. In this context, we describe a patient-centric nano-gel-nano system capable of sustained generation of tumor-associated antigens and release of adjuvants. This is achieved through the specific delivery of drugs to cancer cells and antigens/adjuvants to immune cells over the long term, maintaining proper concentrations within the tumor site with a single injection. This system demonstrates local immunity against tumors with a single injection, enhances the therapeutic efficacy of immune checkpoint blockades, and induces systemic and memory T cell responses, thus minimizing systemic side effects.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124962, 2025 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-39146628

RESUMO

Two isostructural, three-dimensional, interpenetrated amino-functionalized Metal-Organic Frameworks (Co-2AIN-MOF and Cd-2AIN-MOF) based on 2-aminoisonicotinic acid (2AIN) were synthesized, structurally characterized and determined. Based on the PXRD analysis, the solvent exchange hardly changed their framework structure, and the samples fully activated by methanol can be achieved and examined by infrared spectroscopy. Due to the presence of the carbonyl group and free amino groups in the pore of the framework, the NH3 uptakes of Co-2AIN-MOF and Cd-2AIN-MOF are 11.70 and 13.81 mmol/g and at 1 bar, respectively. In-situ Infrared spectroscopy and DFT calculations revealed the different adsorption sites and processes between Co-2AIN-MOF and Cd-2AIN-MOF.

3.
J Colloid Interface Sci ; 677(Pt A): 68-78, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39083893

RESUMO

Carbon/metal composites derived from metal-organic frameworks (MOFs) have attracted widespread attention due to their excellent electronic conductivity, adjustable porosity, and outstanding stability. However, traditional synthesis methods are limited by the dense stereo geometry and large crystal grain size of MOFs, resulting in many metals active sites are buried in the carbon matrix. While the common strategy involves incorporating additional dispersed media into material, this leads to a decrease in practical metal content. In this study, nanosized copper-metal-organic frameworks (Cu-MOFs) are in-situ grown on surface of carbon spheres by pre-anchoring copper ions, and the hybrid composite of porous carbon/copper oxide with high copper atom utilization rate is prepared through activation and pyrolysis methods. This strategy effectively addresses the issue of insufficient exposure of metal sites, and the obtained composite material exhibits high effective copper atom utilization rate, large specific surface area (2052.3 m2·g-1), diverse pore structure, outstanding specific capacity (1076.5F·g-1 at 0.5 A·g-1), and excellent cycle stability. Furthermore, this highly atom-economical universal method has positive significance in application fields of catalysis, energy storage, and adsorption.

4.
J Colloid Interface Sci ; 677(Pt B): 91-100, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39137566

RESUMO

The further commercialization of layer-structured Ni-rich LiNi0.83Co0.11Mn0.06O2 (NCM83) cathode for high-energy lithium-ion batteries (LIBs) has been challenged by severe capacity decay and thermal instability owing to the microcracks and harmful phase transitions. Herein, Ti4+-doped NCM83 cathode materials are rationally designed via a simple and low-cost in-situ modification method to improve the crystal structure and electrode-electrolyte interface stability by inhibiting irreversible polarizations and harmful phase transitions of the NCM83 cathode materials due to Ti4+-doped forms stronger metal-O bonds and a stable bulk structural. In addition, the optimal doping amount of the composite cathode material is also determined through the results of physical characterization and electrochemical performance testing. The optimized Ti4+-doped NCM83 cathode material presents wider Li+ ions diffusion channels (c = 14.1687 Å), lower Li+/Ni2+ mixing degree (2.68 %), and compact bulk structure. The cell assembled with the optimized Ti4+-doped NCM83 cathode material exhibits remarkable capacity retention ratio of 95.4 % after 100cycles at 2.0C and room temperature, and outstanding reversible discharge specific capacity of 148.2 mAh g-1 at 5.0C. Even under elevated temperature of 60 °C, it delivers excellent capacity retention ratio of 92.2 % after 100cycles at 2.0C, which is significantly superior to the 47.9 % of the unmodified cathode material. Thus, the in-situ Ti4+-doped strategy presents superior advantages in enhancing the structural stability of Ni-rich cathode materials for LIBs.

5.
J Colloid Interface Sci ; 677(Pt B): 769-779, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39173510

RESUMO

Potassium-ion batteries (PIBs) are gaining attention among emerging technologies for their cost-effectiveness and the abundance of resources they utilize. Within this context, bismuth oxyhalides (BiOX) have emerged as exceptional candidates for anode materials in PIBs due to their unique structural and superior electrochemical properties. However, challenges such as structural instability and low electronic conductivity remain to be addressed. In this study, a flower-like BiOBr0.5Cl0.5/rGO composite anode material was synthesized, demonstrating outstanding K+ storage performance. The self-hybridized structure enhances ion adsorption and diffusion, which in turn improves charge and discharge efficiency as well as long-term stability. In situ X-ray diffraction (XRD) tests confirmed the gradual release and alloying potassium storage mechanism of Bi metal, which occurs through the intermediate KxBiOBr0.5Cl0.5 phase within the BiOBr0.5Cl0.5 anode. This composite exhibited a high specific capacity of 246.4 mAh/g at 50 A/g and maintained excellent capacity retention after 2400 cycles at 5 A/g. Additionally, in full battery tests, it showed good rate performance and long cycle life, maintaining a discharge specific capacity of 119.6 mAh/g at a high current density of 10 A/g. Comprehensive characterizations revealed insights into the structural, electrochemical, and kinetic properties, advancing high-performance PIBs.

6.
Methods Mol Biol ; 2857: 9-14, 2025.
Artigo em Inglês | MEDLINE | ID: mdl-39348051

RESUMO

Telomeres in most somatic cells shorten with each cell division, and critically short telomeres lead to cellular dysfunction, cell cycle arrest, and senescence. Thus, telomere shortening is an important hallmark of human cellular senescence. Quantitative fluorescence in situ hybridization (Q-FISH) using formalin-fixed paraffin-embedded (FFPE) tissue sections allows the estimation of telomere lengths in individual cells in histological sections. In our Q-FISH method, fluorescently labelled peptide nucleic acid (PNA) probes are hybridized to telomeric and centromeric sequences in FFPE human tissue sections, and relative telomere lengths (telomere signal intensities relative to centromere signal intensities) are measured. This chapter describes our Q-FISH protocols for assessing relative telomere lengths in FFPE human tissue sections.


Assuntos
Hibridização in Situ Fluorescente , Inclusão em Parafina , Ácidos Nucleicos Peptídicos , Telômero , Humanos , Hibridização in Situ Fluorescente/métodos , Telômero/genética , Telômero/metabolismo , Ácidos Nucleicos Peptídicos/metabolismo , Ácidos Nucleicos Peptídicos/genética , Inclusão em Parafina/métodos , Fixação de Tecidos/métodos , Homeostase do Telômero , Centrômero/metabolismo , Centrômero/genética
7.
J Environ Sci (China) ; 147: 523-537, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003068

RESUMO

Due to its high efficiency, Fe(II)-based catalytic oxidation has been one of the most popular types of technology for treating growing organic pollutants. A lot of chemical Fe sludge along with various refractory pollutants was concomitantly produced, which may cause secondary environmental problems without proper disposal. We here innovatively proposed an effective method of achieving zero Fe sludge, reusing Fe resources (Fe recovery = 100%) and advancing organics removal (final TOC removal > 70%) simultaneously, based on the in situ formation of magnetic Ca-Fe layered double hydroxide (Fe3O4@CaFe-LDH) nano-material. Cations (Ca2+ and Fe3+) concentration (≥ 30 mmol/L) and their molar ratio (Ca:Fe ≥ 1.75) were crucial to the success of the method. Extrinsic nano Fe3O4 was designed to be involved in the Fe(II)-catalytic wastewater treatment process, and was modified by oxidation intermediates/products (especially those with COO- structure), which promoted the co-precipitation of Ca2+ (originated from Ca(OH)2 added after oxidation process) and by-produced Fe3+ cations on its surface to in situ generate core-shell Fe3O4@CaFe-LDH. The oxidation products were further removed during Fe3O4@CaFe-LDH material formation via intercalation and adsorption. This method was applicable to many kinds of organic wastewater, such as bisphenol A, methyl orange, humics, and biogas slurry. The prepared magnetic and hierarchical CaFe-LDH nanocomposite material showed comparable application performance to the recently reported CaFe-LDHs. This work provides a new strategy for efficiently enhancing the efficiency and economy of Fe(II)-catalyzed oxidative wastewater treatment by producing high value-added LDHs materials.


Assuntos
Oxirredução , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluentes Químicos da Água , Poluentes Químicos da Água/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Catálise , Ferro/química
8.
J Environ Sci (China) ; 147: 642-651, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003079

RESUMO

Nowadays, it is still a challenge to prepared high efficiency and low cost formaldehyde (HCHO) removal catalysts in order to tackle the long-living indoor air pollution. Herein, δ-MnO2 is successfully synthesized by a facile ozonation strategy, where Mn2+ is oxidized by ozone (O3) bubble in an alkaline solution. It presents one of the best catalytic properties with a low 100% conversion temperature of 85°C for 50 ppm of HCHO under a GHSV of 48,000 mL/(g·hr). As a comparison, more than 6 times far longer oxidation time is needed if O3 is replaced by O2. Characterizations show that ozonation process generates a different intermediate of tetragonal ß-HMnO2, which would favor the quick transformation into the final product δ-MnO2, as compared with the relatively more thermodynamically stable monoclinic γ-HMnO2 in the O2 process. Finally, HCHO is found to be decomposed into CO2 via formate, dioxymethylene and carbonate species as identified by room temperature in-situ diffuse reflectance infrared fourier transform spectroscopy. All these results show great potency of this facile ozonation routine for the highly active δ-MnO2 synthesis in order to remove the HCHO contamination.


Assuntos
Formaldeído , Compostos de Manganês , Óxidos , Ozônio , Ozônio/química , Compostos de Manganês/química , Formaldeído/química , Óxidos/química , Poluentes Atmosféricos/química , Oxirredução , Temperatura , Poluição do Ar em Ambientes Fechados/prevenção & controle , Catálise
9.
ACS Sens ; 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39350515

RESUMO

Transition metal oxide semiconductors have great potential for use in H2 sensors, but in recent years, the strange phenomena about gas-sensitive performance associated with their special properties have been more widely discussed in research. In some cases, the resistance of transition metal oxide gas sensors will emerge with some changes contrary to their intrinsic semiconductor characteristics, especially in gas sensor research of WO3. Based on the hydrothermal synthesis of WO3, our work focuses on the abnormal change of tungsten oxide resistance to different gases at low temperature (80-200 °C) and high temperature (above 200 °C). Through in situ FT-IR and in situ XPS, combined with density functional theory calculations, a new reasonable explanation of WO3 is proposed for the abnormal resistance change caused by temperature and the strange response due to gas concentration. The occurrence of these findings can be attributed to the synergistic effect resulting from the presence of two contributing factors. One of them is attributed to the alteration in the surface valence state of WO3 induced by gas, resulting in the reduction of W6+. The other one is due to the reaction between gas and adsorbed oxygen on the surface of WO3. This work presents a novel and rational concept for addressing the reaction mechanism between gas and transition metal oxide semiconductors, thereby paving the way for the development of highly efficient gas sensors based on transition metal oxide semiconductors.

10.
Chemistry ; : e202402867, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352131

RESUMO

As part of a much larger study on non-covalent interactions in binary adducts, we have explored the solid-state structures of bromopentafluorobenzene (C6F5Br) using differential scanning calorimetry (DSC), variable-temperature powder X-ray diffraction (VT-PXRD), and single-crystal X-ray diffraction (SXD). DSC data initially indicated a single solid-state phase below the freezing point, but revealed additional weak transitions upon heating. The crystal structures of three solid-state phases have been solved. The SXD data showed that phases I and IV are centrosymmetric, whilst phase II is polar. However, the structure of phase III remains elusive due to the changing phase behaviour of C6F5Br that is determined as much as by kinetics as thermodynamics. The results underline the need for multiple analytical techniques to study non-covalent interactions and offer valuable data for refining computational models in crystal structure prediction and machine learning. A comparison with the iodinated counterpart is also made.

11.
Angew Chem Int Ed Engl ; : e202413417, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352449

RESUMO

The substantial promotion of hydrogen evolution reaction (HER) catalytic performance relies on the breakup of the Sabatier principle, which can be achieved by the alternation of the support and electronic metal support interaction (EMSI) is noticed. Due to the utilization of tungsten disulfides as support for platinum (Pt@WS2), surprisingly, Pt@WS2 demands only 31 mV overpotential to attain 10 mA cm-2 in acidic HER test, corresponding to a 2.5-fold higher mass activity than benchmarked Pt/C. The pH dependent electrochemical measurements associated with H2-TPD and in-situ Raman spectroscopy indicate a hydrogen spillover involved HER mechanism is confirmed. The WS2 support triggers a higher hydrogen binding strength for Pt leading to the increment in hydrogen concentration at Pt sites proved by upshifted d band center as well as lower Gibbs free energy of hydrogen, favourable for hydrogen spillover. Besides, the WS2 shows a comparably lower effect on Gibbs free energy for different Pt layers (-0.50 eV layer-1) than carbon black (-0.88 eV layer-1) contributing to a better Pt utilization. Also, the theoretical calculation suggests the hydrogen spillover occurs on the 3rd Pt layer in Pt@WS2; moreover, the energy barrier is lowered with increment in hydrogen coverage on Pt.

12.
Support Care Cancer ; 32(10): 695, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352516

RESUMO

PURPOSE: Ductal carcinoma in situ (DCIS) of the breast is one of the most common pre-invasive cancers diagnosed in women. Quality of life (QoL) is extremely important to assess in studies including these patients due to the favorable prognosis of the disease. The primary objective of this systematic review was to compile a comprehensive list of QoL issues, all existing QoL assessment tools, and patient-reported outcome measures used to assess DCIS. METHODS: A search was conducted on Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases from inception to August 2023, using keywords such as "ductal carcinoma in-situ", "quality of life", and "patient-reported outcomes." QoL issues and QoL tools in primary research studies were extracted. RESULTS: A total of 67 articles identified issues pertaining to patients with DCIS spanning physical, functional, and psychosocial QoL domains. Physical and functional issues observed in patients included pain, fatigue, and impaired sexual functioning. Psychosocial issues such as anxiety, depression, and confusion about one's disease were also common. QoL tools included those that assessed general QoL, breast cancer-specific tools, and issue-specific questionnaires. CONCLUSION: The current instruments available to assess QoL in patients with DCIS do not comprehensively capture the issues that are pertinent to patients. Thus, the modification of existing tools or the creation of a DCIS-specific QoL tool is recommended to ensure that future research will be sensitive towards challenges faced by patients with DCIS.


Assuntos
Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Humanos , Neoplasias da Mama/psicologia , Feminino , Carcinoma Intraductal não Infiltrante/psicologia , Carcinoma Intraductal não Infiltrante/terapia
13.
ACS Synth Biol ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39353593

RESUMO

Artificial cells with reconstructed cellular functions could serve as practical protocell models for studying the early cellular life on the Earth. Investigating the viability of protocell models in extreme environments where life may have arisen is important for advancing origin-of-life research. Here, we tested the survivability of lipid membrane vesicles in deep-sea environments. The vesicles were submerged in the deep-sea floor with a human-occupied vehicle. Although most of the vesicles were broken, some vesicles maintained a spherical shape after the dives. When a cell-free protein synthesis system was encapsulated inside, a few vesicles remained even after a 1,390 m depth dive. Interestingly, such artificial cells could subsequently synthesize protein in a nutrient-rich buffer solution. Together with on shore experiments showing artificial cells synthesized protein under high pressure, our results suggest artificial cells may be able to express genes in deep-sea environments where thermal energy is available from hydrothermal vents.

14.
Water Res ; 267: 122548, 2024 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-39357156

RESUMO

Structural Fe in phyllosilicates represents a crucial and potentially renewable reservoir of electron equivalents for contaminants reduction in aquatic and soil systems. However, it remains unclear how in-situ modification of Fe redox states within Fe-bearing phyllosilicates, induced by electron shuttles such as naturally occurring organics, influences the fate of contaminants. Herein, this study investigated the processes and mechanism of Cr(VI) reduction on two typical Fe(II/III)-bearing phyllosilicates, biotite and chlorite, in the presence of cysteine (Cys) at circumneutral pH. The experimental results demonstrated that Cys markedly enhanced the rate and extent of Cr(VI) reduction by biotite/chlorite, likely because of the formation of Cr(V)-organic complexes and consequent electron transfer from Cys to Cr(V). The concomitant production of non-structural Fe(II) (including aqueous Fe(II), surface bound Fe(II), and Cys-Fe(II) complex) cascaded transferring electrons from Cys to surface Fe(III), which further contributed to Cr(VI) reduction. Notably, structural Fe(II) in phyllosilicates also facilitated Cr(VI) reduction by mediating electron transfer from Cys to structural Fe(III) and then to edge-sorbed Cr(VI). 57Fe Mössbauer analysis revealed that cis-coordinated Fe(II) in biotite and chlorite exhibits higher reductivity compared to trans-coordinated Fe(II). The Cr end-products were insoluble Cr(III)-organic complex and sub-nanometer Cr2O3/Cr(OH)3, associated with residual minerals as micro-aggregates. These findings highlight the significance of in-situ produced Fe(II) from Fe(II/III)-bearing phyllosilicates in the cycling of redox-sensitive contaminants in the environment.

15.
Talanta ; 282: 126941, 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39357401

RESUMO

With the emergence of numerous food safety problems, rapid and accurate detection of histamine in food spoilage remains a challenge. To this end, we developed a simple design and easy synthesis of fluorescein-based probe FCHO to achieve specific and rapid (<1 s) quantitative detection of histamine through "imine formation" reaction. Significant enhanced fluorescence signal in response to histamine enabled our probe with high sensitivity as low as 51 nM. Utilizing the visualized fluorescence color changes of the probe as histamine increasing, we combined it with paper-based test chip to construct a color-resolved and highly selective recognition system. In addition, our proposed probe has been successfully used to visually imaging histamine changes in fish samples. Finally, for the first time, we have proved it possesses reliable ability to directly in situ imaging the distribution of histamine in whole spoiled fish. Thus, our strategy will provide great potential for monitoring food spoilage.

16.
Int J Surg Pathol ; : 10668969241286057, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39360388

RESUMO

While some forms of invasive or in situ carcinoma of the breast may be partly composed of signet-ring cells, signet-ring cells rarely become a prominent feature of pleomorphic lobular carcinoma in situ (LCIS). We report a rare example of pleomorphic LCIS composed predominantly of signet-ring cells with a papillary pattern mimicking ductal carcinoma in situ (DCIS). A 58-year-old woman presented with a mass in the left breast detected by ultrasonography. Fourteen years previously, the patient underwent right breast-conserving surgery for invasive breast carcinoma of no special type. Ultrasonography revealed an irregular parallel, angular hypoechoic mass measuring 1.5 cm in the left breast. An ultrasound-guided core needle core biopsy was conducted. Microscopically, the lesion was composed of epithelial cells supported by a fibrovascular stroma. The majority (> 70%) of the lesional cells between the fibrovascular stalks showed signet-ring cell features. Some of the nuclei of the signet-ring cells showed intermediate-grade atypia. A mucicarmine stain showed intracytoplasmic mucin in the signet-ring cells. Immunohistochemistry for E-cadherin was negative in the tumor cells. After surgical excision, the final diagnosis was a pleomorphic LCIS. To our knowledge, there have been no previous reports of pleomorphic LCIS consisting primarily of signet-ring cells with a papillary pattern.

17.
Adv Sci (Weinh) ; : e2408754, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39360598

RESUMO

Surface reconstruction plays an essential role in electrochemical catalysis. The structures, compositions, and functionalities of the real catalytic species and sites generated by reconstruction, however, are yet to be clearly understood, for the metastable or transit state of most reconstructed structures. Herein, a series of NiFe oxalates (NixFe1- xC2O4, x = 1, 0.9, 0.7, 0.6, 0.5, and 0) are synthesized for overall water splitting electrocatalysis. Whilst NixFe1-xC2O4 shows great hydrogen evolution reaction (HER) activity, the in situ reconstructed NixFe1-xOOH exhibits outstanding oxygen evolution reaction (OER) activity. As identified by the in situ Raman spectroscopy and quasi-in situ X-ray absorption spectroscopy (XAS) techniques, reconstructions from NixFe1-xC2O4 into defective NixFe1-xOOH and finally amorphous NixFe1-xOOH active species (R-NixFe1-xOOH) are confirmed upon cyclic voltammetry processes. Specifically, the fully reconstructed R-Ni0.6Fe0.4OOH demonstrates the best OER activity (179 mV to reach 10 mA cm-2), originating from its abundant real active sites and optimal d-band center. Benefiting from the reconstruction, an alkaline electrolyzer composed of a Ni0.6Fe0.4C2O4 cathode and an in situ reconstructed R-Ni0.6Fe0.4OOH anode achieves a superb overall water splitting performance (1.52 V@10 mA cm-2). This work provides an in-depth structure-property relationship understanding on the reconstruction of catalysts and offers a new pathway to designing novel catalyst.

18.
Daru ; 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39361194

RESUMO

OBJECTIVES: In the recent years, in-situ hydrogel based on gellan gum has been investigated for delivery of various drug molecules particularly to treat neurological disorders via intranasal route. The major objective of the present manuscript is to review the recent research studies exploring gellan gum as ionic triggered in-situ gel for intranasal administration to enhance absorption of drugs and to increase their therapeutic efficacy. METHODS: This review include literature from 1982 to 2023 and were collected from various scientific electronic databases like Scopus, PubMed and Google Scholar to review source, chemistry, ionotropic gelation mechanism, and recent research studies for gellan gum based in-situ hydrogel for intransasl administration.Keywords such as gellan gum, in-situ hydrogel, intranasal administration and brain targeting were used to search literature. The present review included the research studies which explored gellan gum based in-situ gel for intranasal drug delivery. RESULTS: The findings have shown enhanced biavailability of various drugs upon intranasal administration using gellan-gum based in-situ hydrogel.Moreover, the review indicated that intranasal administration of in-situ hydrogel facilitate to overcome blood brain barrier effectively. Hence, significantly higher drug concentration was found to be achieved in brain tissues upon intranasal administration than that of other routes like oral and intravenous. CONCLUSION: The present work conducted a comprehensive review for gellan gum based in-situ hydrogel particularly for intransal administration to overcome BBB. The study concluded that gellan gum based in-situ hydrogel could be potential promising delivery system for intranasal administration to improve bioavailability and efficacy of drugs specifically to treat neurological disorders.

19.
3D Print Addit Manuf ; 11(3): e1087-e1099, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39359574

RESUMO

Additive manufacturing/three-dimensional printing (AM/3DP) processes promise a flexible production modality to fabricate a complex build directly from its digital design file with minimal postprocessing. However, some critical shortcomings of AM/3DP processes related to the build quality and process repeatability are frequently experienced and reported in the literature. In this study, an in situ real-time nondestructive monitoring framework based on the dispersive properties of phononic crystal artifacts (PCAs) to address such quality challenges is described. Similar to a witness coupon, a PCA is printed alongside a build while it is interrogated and monitored with ultrasound. A PCA is substantially smaller than the actual build. Due to its periodic internal structures, a PCA creates pass and stop bands in its spectral response, which are sensitive to the variations in its process and material parameters. These periodic structures, representing the geometric complexities of an actual build, are designed for a specific monitoring objective(s) in AM/3DP. As a model application, in this demonstration study, the effect of the laser scanning speed of a slective laser melting (SLM) printer on the spectral properties of metal PCAs (mPCAs) is ultrasonically evaluated offline. The dependency of the pressure and shear wave speeds, the apparent Young's and shear moduli, and Poisson's ratio on the scanning speed are quantified, and it is found that they are highly sensitive to the laser scanning speed of an SLM printer. The sensitivity of the peaks of the pressure and shear spectral waveforms acquired for the identical mPCA designs printed on the same build plate with the same process parameters is also quantified. For powder-based AM/3DP technologies, where scanning speed is among the crucial process parameters such as laser power and bed temperature, the reported correlations between scanning speeds and the mechanical and spectral features of the mPCAs are expected to be instrumental in developing in situ real-time monitoring systems.

20.
Artigo em Inglês | MEDLINE | ID: mdl-39361518

RESUMO

Mixed-dimensional nanomaterials composed of one-dimensional (1D) and two-dimensional (2D) nanomaterials, such as graphene-silver nanowire (AgNW) composite sandwiched structures, are promising candidates as building blocks for multifunctional structures and materials. However, their mechanical behavior and failure mechanism have not yet been fully understood. In this work, we have performed integrated experimental, theoretical, and numerical studies to explore the performance and failure modes of graphene-AgNW composite under tensile and impact loading conditions. In situ tensile tests using a nanoindenter, implemented with a push-to-pull device and a laser-induced projectile impact test system, are used to shed light on load-bearing mechanisms in graphene-AgNW composites. Multiple failure modes have been observed in both experimental setups and analyzed with numerical and theoretical models. Results show that in the tensile loading the distribution of AgNW, as characterized by the effective free length, is the key parameter determining the failure mode. As for the impact failure scenarios, compared with failure modes observed in pure graphene cases, the mechanical reinforcing effect of AgNW will transform the failure mode from a scattered tensile fracture along radial directions to a shear failure that is constrained in a relatively local domain. Theoretical analysis using shear lag modeling, Timoshenko plate theory, molecular dynamics modeling, and finite element modeling approaches are adopted to further establish the failure modes.

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