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1.
Nature ; 629(8011): 335-340, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38658759

RESUMO

Flexible and large-area electronics rely on thin-film transistors (TFTs) to make displays1-3, large-area image sensors4-6, microprocessors7-11, wearable healthcare patches12-15, digital microfluidics16,17 and more. Although silicon-based complementary metal-oxide-semiconductor (CMOS) chips are manufactured using several dies on a single wafer and the multi-project wafer concept enables the aggregation of various CMOS chip designs within the same die, TFT fabrication is currently lacking a fully verified, universal design approach. This increases the cost and complexity of manufacturing TFT-based flexible electronics, slowing down their integration into more mature applications and limiting the design complexity achievable by foundries. Here we show a stable and high-yield TFT platform for the fabless manufacturing of two mainstream TFT technologies, wafer-based amorphous indium-gallium-zinc oxide and panel-based low-temperature polycrystalline silicon, two key TFT technologies applicable to flexible substrates. We have designed the iconic 6502 microprocessor in both technologies as a use case to demonstrate and expand the multi-project wafer approach. Enabling the foundry model for TFTs, as an analogy of silicon CMOS technologies, can accelerate the growth and development of applications and technologies based on these devices.


Assuntos
Silício , Transistores Eletrônicos , Silício/química , Eletrônica/instrumentação , Índio/química , Gálio/química , Óxido de Zinco/química , Desenho de Equipamento , Semicondutores
2.
Anal Chem ; 96(19): 7577-7584, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38696338

RESUMO

Owing to the separation of field-effect transistor (FET) devices from sensing environments, extended-gate FET (EGFET) biosensor features high stability and low cost. Herein, a highly sensitive EGFET biosensor based on a GaN micropillar array and polycrystalline layer (GMP) was fabricated, which was prepared by using simple one-step low-temperature MOCVD growth. In order to improve the sensitivity and detection limit of EGFET biosensor, the surface area and the electrical conductivity of extended-gate electrode can be increased by the micropillar array and the polycrystalline layer, respectively. The designed GMP-EGFET biosensor was modified with l-cysteine and applied for Hg2+ detection with a low limit of detection (LOD) of 1 ng/L, a high sensitivity of -16.3 mV/lg(µg/L) and a wide linear range (1 ng/L-24.5 µg/L). In addition, the detection of Hg2+ in human urine was realized with an LOD of 10 ng/L, which was more than 30 times lower than that of reported sensors. To our knowledge, it is the first time that GMP was used as extended-gate of EGFET biosensor.


Assuntos
Técnicas Biossensoriais , Limite de Detecção , Mercúrio , Humanos , Mercúrio/urina , Mercúrio/análise , Transistores Eletrônicos , Gálio/química , Eletrodos
3.
Opt Express ; 32(10): 16867-16878, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858883

RESUMO

In this paper, a highly integrated terahertz (THz) biosensor is proposed and implemented, which pioneered the preparation of low-temperature gallium arsenide (LT-GaAs) thin film photoconductive antenna (PCA) on the sensor for direct generation and detection of THz waves, simplifying complex terahertz time-domain spectroscopy (THz-TDS) systems. A latch type metasurface is deposited in the detection region to produce a resonance absorption peak at 0.6 THz that is independent of polarisation. Microfluidics is utilised and automatic injection is incorporated to mitigate the experimental effects of hydrogen bond absorption of THz waves in aqueous-based environment. Additionally, cell damage is minimised by regulating the cell flow rate. The biosensor was utilised to detect the concentration of three distinct sizes of bacteria with successful results. The assay was executed as a proof of concept to detect two distinct types of breast cancer cells. Based on the experimental findings, it has been observed that the amplitude and blueshift of the resonance absorption peaks have the ability to identify and differentiate various cancer cell types. The findings of this study introduce a novel approach for developing microfluidic THz metasurface biosensors that possess exceptional levels of integration, sensitivity, and rapid label-free detection capabilities.


Assuntos
Arsenicais , Técnicas Biossensoriais , Gálio , Espectroscopia Terahertz , Gálio/química , Arsenicais/química , Técnicas Biossensoriais/instrumentação , Espectroscopia Terahertz/instrumentação , Humanos , Desenho de Equipamento , Microfluídica/instrumentação
4.
Analyst ; 149(16): 4267-4275, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38904993

RESUMO

Vertical flow assay (VFA) is an effective point-of-care (POC) diagnostic tool for widespread application. Nevertheless, the lack of multi-target detection and multi-signal readout capability still remains a challenge. Herein, a brand new VFA scheme for multi-target saliva detection based on electronic tags was proposed, where AlGaN/GaN HEMT sensors modified with different bio-receptors as electronic tags endowed the VFA with multi-target detection capability. In addition, the use of electronic tags instead of optical tags allowed the VFA to simultaneously carry out direct multi-target readouts, which ensure effective POC diagnostics for saliva analysis. Moreover, by integrating a hydrophilically optimized micro-sieve, impurities like sticky filaments, epidermal cells and other large-scale charged particles in saliva were effectively screened, which enabled the direct detection of saliva using AlGaN/GaN HEMT sensors. Glucose, urea, and cortisol were selected to verify the feasibility of the multi-target e-VFA scheme, and the results showed that the limit of detection (LOD) was as low as 100 aM. The linear response was demonstrated in the dynamic range of 100 aM to 100 µM, and the specificity, long-term stability and validity of the actual saliva test were also verified. These results demonstrated that the as-proposed e-VFA has potential for application in saliva detection for simultaneous multi-target detection, and it is expected to achieve the real-time detection of more biological targets in saliva.


Assuntos
Gálio , Hidrocortisona , Limite de Detecção , Saliva , Saliva/química , Gálio/química , Humanos , Hidrocortisona/análise , Glucose/análise , Ureia/análise , Ureia/química , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Compostos de Alumínio/química
5.
Inorg Chem ; 63(33): 15409-15420, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39116415

RESUMO

Microorganisms of the ESKAPE group pose an enormous threat to human well-being, thus requiring a multidisciplinary approach for discovering novel drugs that are not only effective but utilize an innovative mechanism of action in order to decrease fast developing resistance. A promising but still hardly explored implementation in the "Trojan horse" antibacterial strategy has been recognized in gallium, an iron mimicry species with no known function but exerting a bacteriostatic/bactericidal effect against some representatives of the group. The study herewith focuses on the bacterium A. baumannii and its siderophore acinetobactin in its two isomeric forms depending on the acidity of the medium. By applying the powerful tools of the DFT approach, we aim to delineate those physicochemical characteristics that are of great importance for potentiating gallium's ability to compete with the native ferric cation for binding acinetobactin such as pH, solvent exposure (dielectric constant of the environment), different metal/siderophore ratios, and complex composition. Hence, the provided results not only furnish some explanation of the positive effect of three Ga3+-based anti-infectives in terms of metal cation competition but also shed light on reported in vitro and in vivo observations at a molecular level in regard to gallium's antibacterial effect against A. baumannii.


Assuntos
Acinetobacter baumannii , Antibacterianos , Teoria da Densidade Funcional , Gálio , Testes de Sensibilidade Microbiana , Gálio/química , Gálio/farmacologia , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Oxazóis/química , Oxazóis/farmacologia , Estrutura Molecular , Imidazóis/química , Imidazóis/farmacologia
6.
Nanotechnology ; 35(36)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38861946

RESUMO

Breast cancer is one of the most basilisk cancers for women due to its high mortality rate which can be prevented drastically with early-stage detection. In this work, the adsorption mechanism of two volatile organic compounds that are present in the breath of breast cancer patients, 2-Methyloctane and 3, 3-Dimethylpentane, has been investigated on aluminum phosphide nanotubes (AlPNT) and gallium phosphide nanotubes (GaPNT) in order to understand their feasibility as sensor materials to diagnosis breast cancer at early stage. We have used the quantum mechanical approach by employing density functional theory using B3LYP-D3 hybrid potential for noncovalent interaction along with the LanL2DZ basis in the Gaussian 09 software package. The adsorption properties analyses suggest that GaPNT exhibits better sensing behavior as well as proclaims 12.6% greater adsorption energy for 2-Methyloctane and 9.4% greater adsorption energy for 3, 3-Dimethylpentane than AlPNT. Other structural and electric properties analyses satisfy this conclusion and suggest that GaPNT exhibits higher stability than AlPNT and could possibly be a potential candidate for developing biosensors to detect breast cancer at the preliminary stages.


Assuntos
Neoplasias da Mama , Teoria da Densidade Funcional , Nanotubos , Fosfinas , Neoplasias da Mama/diagnóstico , Humanos , Feminino , Nanotubos/química , Fosfinas/química , Adsorção , Gálio/química , Octanos/química , Compostos Orgânicos Voláteis/análise , Técnicas Biossensoriais/métodos
7.
Phys Chem Chem Phys ; 26(25): 17817-17829, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38884203

RESUMO

There is currently a great deal of interest in realizing localized surface plasmon resonances (LSPRs) in two distinct windows in the near-infrared (NIR) spectrum for in vivo biosensing and medical applications, the biological window (BW) I and II (BW I, 700-900 nm; BW II, 1000-1700 nm). This study aims to demonstrate that LSPRs of Ga-doped ZnO (GZO) core-silver (Ag) shell structures exhibit promising features for biological applications in the NIR BW I and II. Here, we study three different shapes for nanoshells: the core-shell nanosphere, nanorod, and nanodisk. In the calculation of the optical response of these nanoshells, an effective medium approach is first used to reduce the dielectric function of a nanoshell to that of an equivalent homogenous NP with an effective dielectric function. Then, the LSPR spectra of nanoshells are calculated using the modified long-wavelength approximation (MLWA), which corrects the polarizability of the equivalent NP as obtained by Gans theory. Through numerical investigations, we examine the impacts of the core and shell sizes of the proposed nanoshells as well as the medium refractive index on the position and line width of the plasmon resonance peaks. It is shown that the plasmon resonances of the three proposed nanoshells exhibit astonishing resonance tunability in the NIR region by varying their geometrical parameters. Specifically, the improved spectrum characteristics and tunability of its plasmon resonances make the GZO-Ag nanosphere a more viable platform for NIR applications than the spherical metal colloid. Furthermore, we demonstrate that the sensitivity and figure of merit (FOM) of the plasmon resonances may be significantly increased by using GZO-Ag nanorods and nanodisks in place of GZO-Ag nanospheres. It is found that the optical properties of the transverse plasmon resonance of the GZO-Ag nanodisk are superior to all plasmon resonances produced by the GZO-Ag nanorods and GZO-Ag nanospheres in terms of sensitivity and FOM. The FOM of the transverse plasmon mode of the GZO-Ag nanodisk is almost two orders of magnitude higher than that of the longitudinal and transverse plasmon modes of the GZO-Ag nanorod in BW I and BW II. And it is 1.5 and 2 times higher than the plasmon resonance FOM of GZO-Ag nanospheres in BW I and BW II, respectively.


Assuntos
Técnicas Biossensoriais , Nanosferas , Nanotubos , Prata , Ressonância de Plasmônio de Superfície , Óxido de Zinco , Prata/química , Nanotubos/química , Óxido de Zinco/química , Técnicas Biossensoriais/métodos , Nanosferas/química , Gálio/química , Raios Infravermelhos
8.
Luminescence ; 39(5): e4762, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38698695

RESUMO

Broadband near-infrared (NIR) spectroscopy has gained significant attention due to its versatile application in various fields. In the realm of NIR phosphors, Fe3+ ion is an excellent activator known for its nontoxic and harmless nature. In this study, we prepared an Fe3+-activated SrGa12O19 (SGO) NIR phosphor and analyzed its phase and luminescence properties. Upon excitation at 326 nm, the SGO:Fe3+ phosphor exhibited a broadband emission in the range 700-1000 nm, peaking at 816 nm. The optical band gap of SGO:Fe3+ was evaluated. To enhance the long-lasting phosphorescence, an oxygen vacancy-rich SGO:Fe3+ (VO-SGO:Fe3+) sample was prepared for activation. Interestingly, the increase in the oxygen-vacancy concentration indeed contributed to the activation of persistent luminescence of Fe3+ ions. The VO-SGO:Fe3+ sample has a long duration and high charge storage capacity, allowing it to perform efficiently in various applications. This work provides the foundation for further design of Cr3+-free PersL phosphors with efficient NIR PersL.


Assuntos
Luminescência , Substâncias Luminescentes , Oxigênio , Oxigênio/química , Substâncias Luminescentes/química , Estrôncio/química , Medições Luminescentes , Compostos Férricos/química , Gálio/química , Ferro/química , Espectroscopia de Luz Próxima ao Infravermelho
9.
Luminescence ; 39(5): e4773, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38757733

RESUMO

Two Schiff base probes (S1 and S2) were prepared and synthesized by incorporating thienopyrimidine into salicylaldehyde or 3-ethoxysalicylaldehyde individually, with the aim of detecting Ga3+ and Pd2+ sequentially. Upon chelation with Ga3+, S1 and S2 exhibited fluorescence enhancement in DMSO/H2O buffer. Both S1-Ga3+ and S2-Ga3+ were quenched by Pd2+. The limit of detection for S1 in response to Ga3+ and Pd2+ was 2.86 × 10-7 and 4.4 × 10-9 M, respectively. For S2, the limit of detection for Ga3+ and Pd2+ was 4.15 × 10-8 and 3.0 × 10-9 M, respectively. Furthermore, the complexation ratios of both S1 and S2 with Ga3+ and Pd2+ were determined to be 1:2 through Job's plots, ESI-MS analysis, and theoretical calculations. Two molecular logic gates were constructed, leveraging the response behaviors of S1 and S2. Moreover, the potential utility of S1 and S2 for monitoring Ga3+ and Pd2+ in domestic water was verified.


Assuntos
Corantes Fluorescentes , Gálio , Paládio , Pirimidinas , Bases de Schiff , Bases de Schiff/química , Paládio/química , Pirimidinas/química , Pirimidinas/análise , Gálio/química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Espectrometria de Fluorescência , Estrutura Molecular
10.
Molecules ; 29(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276575

RESUMO

The aim of this work is to explore a new library of coordination compounds for medicinal applications. Gallium is known for its various applications in this field. Presently, indium is not particularly important in medicine, but it shares a lot of chemical traits with its above-mentioned lighter companion, gallium, and is also used in radio imaging. These metals are combined with thiosemicarbazones, ligating compounds increasingly known for their biological and pharmaceutical applications. In particular, the few ligands chosen to interact with these hard metal ions share the ideal affinity for a high charge density. Therefore, in this work we describe the synthesis and the characterization of the resulting coordination compounds. The yields of the reactions vary from a minimum of 21% to a maximum of 82%, using a fast and easy procedure. Nuclear Magnetic Resonance (NMR) and Infra Red (IR) spectroscopy, mass spectrometry, elemental analysis, and X-ray Diffraction (XRD) confirm the formation of stable compounds in all cases and a ligand-to-metal 2:1 stoichiometry with both cations. In addition, we further investigated their chemical and biological characteristics, via UV-visible titrations, stability tests, and cytotoxicity and antibiotic assays. The results confirm a strong stability in all explored conditions, which suggests that these compounds are more suitable for radio imaging applications rather than for antitumoral or antimicrobic ones.


Assuntos
Complexos de Coordenação , Gálio , Tiossemicarbazonas , Gálio/farmacologia , Gálio/química , Índio/química , Tiossemicarbazonas/química , Ligantes , Espectroscopia de Ressonância Magnética , Complexos de Coordenação/química
11.
Pharm Dev Technol ; 29(4): 339-352, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38502579

RESUMO

We recently reported the potential of a new gallium compound, gallium acetylacetonate (GaAcAc) in combating osteoclastic bone resorption through inhibition of osteoclast differentiation and function. Herein, we focused on 3D-printed polylactic acid scaffolds that were loaded with GaAcAc and investigated the impact of scaffold pretreatment with polydopamine (PDA) or sodium hydroxide (NaOH). We observed a remarkable increase in scaffold hydrophilicity with PDA or NaOH pretreatment while biocompatibility and in vitro degradation were not affected. NaOH-pretreated scaffolds showed the highest amount of GaAcAc loading when compared to other scaffolds (p < 0.05). NaOH-pretreated scaffolds with GaAcAc loading showed effective reduction of osteoclast counts and size. The trend was supported by suppression of key osteoclast differentiation markers such as NFAT2, c-Fos, TRAF6, & TRAP. All GaAcAc-loaded scaffolds, regardless of surface pretreatment, were effective in inhibiting osteoclast function as evidenced by reduction in the number of resorptive pits in bovine cortical bone slices (p < 0.01). The suppression of osteoclast function according to the type of scaffold followed the ranking: GaAcAc loading without surface pretreatment > GaAcAc loading with NaOH pretreatment > GaAcAc loading with PDA pretreatment. Additional studies will be needed to fully elucidate the impact of surface pretreatment on the efficacy and safety of GaAcAc-loaded 3D-printed scaffolds.


Assuntos
Reabsorção Óssea , Osteoclastos , Impressão Tridimensional , Alicerces Teciduais , Animais , Osteoclastos/efeitos dos fármacos , Alicerces Teciduais/química , Reabsorção Óssea/tratamento farmacológico , Bovinos , Camundongos , Poliésteres/química , Gálio/química , Gálio/farmacologia , Pentanonas/química , Pentanonas/administração & dosagem , Pentanonas/farmacologia , Hidróxido de Sódio , Diferenciação Celular/efeitos dos fármacos
12.
PLoS One ; 19(8): e0306738, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39141686

RESUMO

In order to implement the fifth generation (5G) communication system for a large number of users, the governments of many countries nominated the low 5G frequency band between 3.3 and 4.3 GHz. This paper proposes a wideband RFPA by designing the input matching network (MN) and output MN of the device using the simplified real frequency technique (SRFT) and the harmonic tuning network. The load-pull and source-pull is applied at multiple points for 100 MHz intervals over the bandwidth to obtain the optimum impedances at the output and input of the 10W Gallium Nitride (GaN) Cree CGH40010F device. To verify the design, the RFPA is simulated, and the performance is measured between 3.3 and 4.3 GHz. According to experimental findings, the measured drain efficiency (DE) throughout the whole bandwidth ranged from 57.5 to 67.5% at the output power of 40 dBm. Moreover, at the 1 dB compression point between 39.2 and 42.2 dBm output power, the drain efficiency (DE) achieves a high value of 81.2% with an output power of 42.2 dBm at a frequency of 3.3 GHz. The RFPA can obtain a maximum gain of 12.4 dB at 3.5 GHz. The linearity of the RFPA with a two-tone signal is measured and the value is less than -22 dBc all over the band.


Assuntos
Gálio , Gálio/química , Desenho de Equipamento , Amplificadores Eletrônicos , Tecnologia sem Fio/instrumentação
13.
Chempluschem ; 89(6): e202400084, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38457624

RESUMO

Discovering new modifications for oligonucleotide therapeutics is essential for expanding its application to new targets and diseases. In this project, we focus on conjugating metaled ligands to short interfering RNAs (siRNAs) to investigate robust and simple conjugation methods for adding new properties such as real-time imaging to the siRNA. Here we report the chemical synthesis of novel Ga-(III)-corroles for their direct conjugation to siRNAs. Ga-(III)-corrole-siRNAs showed promising results when evaluated for gene silencing and live cell imaging. The knockdown activity of the firefly luciferase reporter gene was measured to evaluate gene silencing activity. Gene silencing studies from two 5'-Ga-(III)-labeled-siRNAs exhibited dose-dependent knockdown with IC50s of 812.7 and 451.4 pM, which is comparable to wild-type (IC50=439.7 pM) in the absence of red light, and IC50s of 562.9 and 354.5 pM, which is also comparable to wild-type (IC50=337.4 pM), in the presence of red light. In addition, imaging studies with Ga-(III)-corrole-modified siRNAs showed intense fluorescence in HeLa cells, highlighting that the Ga-(III)-corrole modification is an effective fluorophore for siRNA tracing and imaging. Moreover, the photodynamic activity of free base corrole vs the Ga-(III)-corrole was evaluated. Results show an increase of light cytotoxicity of the corrole ligand upon the addition of Ga-(III); however, no phototoxicity was observed when Ga-(III) ligands were linked to siRNA. In conclusion, Ga-(III)-corrole-siRNAs show promising results for applications in simultaneous real-time imaging and gene silencing.


Assuntos
Gálio , Inativação Gênica , RNA Interferente Pequeno , RNA Interferente Pequeno/química , Humanos , Gálio/química , Porfirinas/química , Células HeLa
14.
Chempluschem ; 89(6): e202400221, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38602447

RESUMO

Invited for this month's cover is the group of Jean-Paul Desaulniers at Ontario Tech University. The cover picture shows the successful conjugation of a GaIII-corrole to an siRNA to enable live cell imaging. Read the full text of the article at 10.1002/cplu.202400084.


Assuntos
Gálio , Inativação Gênica , RNA Interferente Pequeno , RNA Interferente Pequeno/química , Humanos , Gálio/química , Porfirinas/química
15.
Colloids Surf B Biointerfaces ; 238: 113888, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38599077

RESUMO

Gallium (Ga) is a well-known liquid metals (LMs) that possesses the features, such as fluidity, low viscosity, high electrical and thermal conductivity, and relative low toxicity. Owing to the weak interactions between Ga atoms, Ga LMs can be adopted for fabrication of various Ga LMs-based functional materials via ultrasonic treatment and mechanical grinding. Moreover, many organic compounds/polymers can be coated on the surface of LMs-based materials through coordination between oxidized outlayers of Ga LMs and functional groups of organic components. Over the past decades, different strategies have been reported for synthesizing Ga LMs-based functional materials and their biomedical applications have been intensively investigated. Although some review articles have published over the past few years, a concise review is still needed to advance the latest developments in biomedical fields. The main context can be majorly divided into two parts. In the first section, various strategies for fabrication of Ga LMs-based functional materials via top-down strategies were introduced and discussed. Following that, biomedical applications of Ga LMs-based functional materials were summarized and design Ga LMs-based functional materials with enhanced performance for cancer photothermal therapy (PTT) and PTT combined therapy were highlighted. We trust this review article will be beneficial for scientists to comprehend this promising field and greatly advance future development for fabrication of other Ga LMs-based functional materials with better performance for biomedical applications.


Assuntos
Gálio , Gálio/química , Humanos , Neoplasias/tratamento farmacológico , Terapia Fototérmica/métodos , Animais
16.
Sci Adv ; 10(17): eadk6285, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38669330

RESUMO

Cryo-electron tomography (cryo-ET) is a powerful method to elucidate subcellular architecture and to structurally analyze biomolecules in situ by subtomogram averaging, yet data quality critically depends on specimen thickness. Cells that are too thick for transmission imaging can be thinned into lamellae by cryo-focused ion beam (cryo-FIB) milling. Despite being a crucial parameter directly affecting attainable resolution, optimal lamella thickness has not been systematically investigated nor the extent of structural damage caused by gallium ions used for FIB milling. We thus systematically determined how resolution is affected by these parameters. We find that ion-induced damage does not affect regions more than 30 nanometers from either lamella surface and that up to ~180-nanometer lamella thickness does not negatively affect resolution. This shows that there is no need to generate very thin lamellae and lamella thickness can be chosen such that it captures cellular features of interest, thereby opening cryo-ET also for studies of large complexes.


Assuntos
Microscopia Crioeletrônica , Tomografia com Microscopia Eletrônica , Microscopia Crioeletrônica/métodos , Tomografia com Microscopia Eletrônica/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Gálio/química
17.
Radiat Prot Dosimetry ; 200(11-12): 1173-1177, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016480

RESUMO

The effect of 60Co gamma irradiation on gallium oxide and titanium oxide (Ga2O3-TiO2) nanocomposites are investigated in the present study. The Ga2O3-TiO2 nanocomposite was synthesized by hydrothermal method at 120°C. The precursors for the synthesis consist of gallium nitrate anhydrous and titanium trichloride along with sodium hydroxide to achieve the pH of 9. The synthesized Ga2O3-TiO2 was subjected to 60Co gamma irradiation for different doses such as 25, 50 and 75 kGy. The morphological, optical and microstructural characteristics were studied using scanning electron microscopy, UV-Visible spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The results shows that the gamma irradiation induces significant changes in the Ga2O3-TiO2 microstructure and there is increase in the grain size and bandgap of the nanocomposites.


Assuntos
Radioisótopos de Cobalto , Gálio , Raios gama , Nanocompostos , Titânio , Titânio/química , Nanocompostos/química , Nanocompostos/efeitos da radiação , Radioisótopos de Cobalto/química , Gálio/química , Difração de Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Microscopia Eletrônica de Varredura
18.
Int J Biol Macromol ; 271(Pt 1): 132494, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38788874

RESUMO

The synthesis of liquid metal-infused hydrogels, typically constituted by polyacrylamide networks crosslinked through covalent bonds, often encounters a conundrum: they exhibit restricted extensibility and a diminished capacity for self-repair, owing to the inherently irreversible nature of the covalent linkages. This study introduces a hydrophobically associated hydrogel embedding gallium (Ga)-droplets, realized through the in situ free radical copolymerization of hydrophobic hexadecyl methacrylate (HMA) and hydrophilic acrylamide (AM) in a milieu containing xanthan gum (XG) and PEDOT:PSS, which co-stabilizes the Ga-droplets. The Ga-droplets, synergistically functioning as conductive agents alongside PEDOT:PSS, also expedite the hydrogel's formation. The resultant XG/PEDOT:PSS-Ga-P(AM-HMA) hydrogel is distinguished by its remarkable extensibility (2950 %), exceptional toughness (3.28 MJ/m3), superior adherence to hydrophobic, smooth substrates, and an innate ability for hydrophobic-driven self-healing. As a strain sensing medium, this hydrogel-based sensor exhibits heightened sensitivity (gauge factor = 12.66), low detection threshold (0.1 %), and robust durability (>500 cycles). Furthermore, the inclusion of glycerol endows the XG/PEDOT:PSS-Ga-P(AM-HMA) hydrogel with anti-freezing properties without compromising its mechanical integrity and sensing acumen. This sensor adeptly captures a spectrum of human movements, from the nuanced radial pulse to extensive joint articulations. This research heralds a novel approach for fabricating multifaceted PAM-based hydrogels with toughness and superior sensing capabilities.


Assuntos
Hidrogéis , Interações Hidrofóbicas e Hidrofílicas , Polímeros , Polissacarídeos Bacterianos , Hidrogéis/química , Polissacarídeos Bacterianos/química , Polímeros/química , Poliestirenos/química , Gálio/química , Metais/química , Compostos Bicíclicos Heterocíclicos com Pontes
19.
Int J Biol Macromol ; 258(Pt 1): 128838, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38128798

RESUMO

Pseudomonas aeruginosa is one of the leading causes of opportunistic infections such as chronic wound infection that could lead to multiple organ failure and death. Gallium (Ga3+) ions are known to inhibit P. aeruginosa growth and biofilm formation but require carrier for localized controlled delivery. Lactoferrin (LTf), a two-lobed protein, can deliver Ga3+ at sites of infection. This study aimed to develop a Ga-LTf complex for the treatment of wound infection. The characterisation of the Ga-LTf complex was conducted using differential scanning calorimetry (DSC), Infra-Red (FTIR) and Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES). The antibacterial activity was assessed by agar disc diffusion, liquid broth and biofilm inhibition assays using the colony forming units (CFUs). The healing capacity and biocompatibility were evaluated using a P.aeruginosa infected wound in a rat model. DSC analyses showed thermal transition consistent with apo-lactoferrin; FTIR confirmed the complexation of gallium to lactoferrin. ICP-OES confirmed the controlled local delivery of Ga3+. Ga-LTf showed a 0.57 log10 CFUs reduction at 24 h compared with untreated control in planktonic liquid broth assay. Ga-LTf showed the highest antibiofilm activity with a 2.24 log10 CFUs reduction at 24 h. Furthermore, Ga-LTf complex is biocompatible without any adverse effect on brain, kidney, liver and spleen of rats tested in this study. Ga-LTf can be potentially promising novel therapeutic agent to treat pathogenic bacterial infections.


Assuntos
Gálio , Ratos , Animais , Gálio/química , Gálio/metabolismo , Gálio/farmacologia , Pseudomonas aeruginosa , Lactoferrina/metabolismo , Antibacterianos/farmacologia , Biofilmes
20.
Dalton Trans ; 53(10): 4526-4543, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38348686

RESUMO

A library of homoleptic mononuclear Ga(III) complexes of the general formula [Ga(DTC)3], where DTC is an alicyclic or a linear dithiocarbamate chelator, is reported. The complexes were prepared in high yields starting from Ga(NO3)3·6H2O and fully characterized by elemental analysis and IR and NMR spectroscopy. Crystals of five of these complexes were obtained. The antitumor activity of the newly synthesized compounds against a panel of human cancer cell lines was evaluated. The chemical nature of the DTC does not have a marked impact on the structural features of the final compound. X-ray crystal structure analyses revealed that all these complexes have a trigonal prismatic geometry with three identical chelating DTCs coordinating the Ga(III) ion. It is noteworthy that in complex 22, [Ga(NHEt)3] (NHEt = N-ethyldithiocarbamate), the asymmetric unit is formed by two independent and structurally different molecules. Cellular studies showed that all the synthesized Ga-DTC complexes exhibit marked cytotoxic activity, even against human colon cancer cells that are less sensitive to cisplatin. Among the tested compounds, 6 ([Ga(CEPipDTC)3], CEPipDTC = (ethoxycarbonyl)-piperidinedithiocarbamate) and 21 ([Ga(Pr-13)3], PR13 = 4 and N-(2-ethoxy-2-oxoethyl)-N-methyldithiocarbamate) are very promising derivatives, but they have no selectivity towards cancer cells. Nevertheless, the obtained data provide a foundation for developing gallium-dithiocarbamate complexes as anticancer agents.


Assuntos
Antineoplásicos , Complexos de Coordenação , Gálio , Neoplasias , Humanos , Gálio/farmacologia , Gálio/química , Antineoplásicos/química , Cisplatino , Quelantes/química , Complexos de Coordenação/química , Linhagem Celular Tumoral
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