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1.
Small ; 20(20): e2308585, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38212280

RESUMEN

This study addresses the challenge of designing simple and environmentally friendly methods for the preparation of effective electromagnetic wave (EMW) absorbing materials with tailored microstructures and multi-component regulation. N, O doped walnut-like porous carbon composite microspheres loaded with FeCo nanoparticles (WPCM/Fe-Co) are synthesized through high-temperature carbonization combined with soap-free emulsion polymerization and hydrothermal methods, avoiding the use of toxic solvents and complex conditions. The incorporation of magnetic components enhances magnetic loss, complementing dielectric loss to optimize EMW attenuation. The unique walnut-like morphology further improves impedance matching. The proportions of Fe and Co components can be adjusted to regulate the material's reflection loss, thickness, and bandwidth, allowing for fine-tuning of absorption performance. At a low filling ratio (16.7%), the optimal WPCM/Fe-Co composites exhibit a minimum reflection loss (RLmin) of -48.34 dB (10.33 GHz, 3.0 mm) and an overall effective absorbing bandwidth (EAB) covering the entire C bands, X bands, and Ku bands. This work introduces a novel approach to composition regulation and presents a green synthesis method for magnetic carbon composite absorbers with high-performance EMW absorption at low loading.

2.
J Xray Sci Technol ; 32(1): 1-15, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37927293

RESUMEN

BACKGROUND: In clinical medicine, low-dose radiographic image noise reduces the quality of the detected image features and may have a negative impact on disease diagnosis. OBJECTIVE: In this study, Adaptive Projection Network (APNet) is proposed to reduce noise from low-dose medical images. METHODS: APNet is developed based on an architecture of the U-shaped network to capture multi-scale data and achieve end-to-end image denoising. To adaptively calibrate important features during information transmission, a residual block of the dual attention method throughout the encoding and decoding phases is integrated. A non-local attention module to separate the noise and texture of the image details by using image adaptive projection during the feature fusion. RESULTS: To verify the effectiveness of APNet, experiments on lung CT images with synthetic noise are performed, and the results demonstrate that the proposed approach outperforms recent methods in both quantitative index and visual quality. In addition, the denoising experiment on the dental CT image is also carried out and it verifies that the network has a certain generalization. CONCLUSIONS: The proposed APNet is an effective method that can reduce image noise and preserve the required image details in low-dose radiographic images.


Asunto(s)
Algoritmos , Tomografía Computarizada por Rayos X , Relación Señal-Ruido , Dosis de Radiación , Tomografía Computarizada por Rayos X/métodos , Procesamiento de Imagen Asistido por Computador/métodos
3.
BMC Plant Biol ; 23(1): 70, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36726056

RESUMEN

The subgenus Rhizirideum in the genus Allium consists of 38 species worldwide and forms five sections (A. sect. Rhizomatosa, A. sect. Tenuissima, A. sect. Rhizirideum, A. sect. Eduardia, and A. sect. Caespitosoprason), A. sect. Caespitosoprason being merged into A. sect. Rhizomatosa recently. Previous studies on this subgenus mainly focused on separate sections. To investigate the inter-section and inter-subgenera phylogenetic relationships and adaptive evolution of A. subg. Rhizirideum, we selected thirteen representative species, which cover five sections of this subgenus and can represent four typical phenotypes of it. We conducted the comparative plastome analysis with our thirteen plastomes. And phylogenetic inferences with CDSs and complete sequences of plastomes of our thirteen species and another fifty-four related species were also performed. As a result, the A. subg. Rhizirideum plastomes were relatively conservative in structure, IR/SC borders, codon usage, and repeat sequence. In phylogenetic results, the inter-subgenera relationships among A. subg. Rhizirideum and other genus Allium subgenera were generally similar to the previous reports. In contrast, the inter-section relationships within our subgenus A. subg. Rhizirideum were newly resolved in this study. A. sect. Rhizomatosa and A. sect. Tenuissima were sister branches, which were then clustered with A. sect. Rhizirideum and A. sect. Eduardia successively. However, Allium Polyrhizum Turcz. ex Regel, type species of A. sect. Caespitosoprason, was resolved as the basal taxon of A. subg. Rhizirideum. Allium siphonanthum J. M. Xu was also found in clade A. subg. Cyathophora instead of clade A. subg. Rhizirideum. The selective pressure analysis was also conducted, and most protein-coding genes were under purifying selection. At the same time, just one gene, ycf2, was found under positive selection, and another three genes (rbcL, ycf1a, ycf1b) presented relaxed selection, which were all involved in the photosynthesis. The low temperature, dry climate, and high altitude of the extreme habitats where A. subg. Rhizirideum species grow might impose intense natural selection forces on their plastome genes for photosynthesis. In summary, our research provides new insights into the phylogeny and adaptive evolution of A. subg. Rhizirideum. Moreover, we suggest that the positions of the A. subg. Rhizirideum species A. polyrhizum and A. siphonanthum should be reconsidered.


Asunto(s)
Allium , Amaryllidaceae , Genoma de Plastidios , Allium/genética , Amaryllidaceae/genética , Filogenia , Secuencias Repetitivas de Ácidos Nucleicos , Evolución Molecular
4.
World J Urol ; 41(6): 1511-1517, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37093318

RESUMEN

OBJECTIVES: The vesicoprostatic muscle (VPM) is a longitudinal smooth muscle that originates from the trigone of the bladder or the opening of the ureter and is involved in urination as part of the detrusor apron. We explored the effect of VPM reconstruction on immediate and early recovery of urinary continence in patients undergoing robot-assisted laparoscopic radical prostatectomy (RALP). PATIENTS AND METHODS: A total of 523 patients with localized prostate cancer were enrolled from June 2018 to June 2020. All patients were diagnosed in our department based on magnetic resonance imaging and pathological findings on prostate biopsy. After 1:1 propensity score matching, 105 patient pairs were matched. The study was approved by our institutional review board and all surgeries were performed by three experienced high-volume surgeons. Demographic data, total operation time, pathological outcomes, the urinary continence rates of the two groups at different times after RALP, and factors influencing postoperative urinary continence after RALP were recorded. Student's t test was used to compare continuous variables and the Pearson χ2 test to compare categorical variables. Logistic regression analysis was used to identify factors affecting immediate and early postoperative urinary control. RESULTS: VPM reconstruction promoted immediate and early recovery of urinary continence (immediate continence, 66.67 vs. 40.00%, P = 0.000; 3-month continence, 80.95 vs. 64.76%, P = 0.008). CONCLUSIONS: VPM reconstruction improved immediate and early urinary continence in patients who underwent RALP.


Asunto(s)
Laparoscopía , Neoplasias de la Próstata , Procedimientos Quirúrgicos Robotizados , Masculino , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Micción , Próstata/patología , Neoplasias de la Próstata/cirugía , Neoplasias de la Próstata/patología , Prostatectomía/métodos , Músculos , Recuperación de la Función , Laparoscopía/métodos
5.
Virus Genes ; 59(5): 653-661, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37310519

RESUMEN

SARS-CoV-2 mutation is minimized through a proofreading function encoded by NSP-14. Most estimates of the SARS-CoV-2 mutation rate are derived from population based sequence data. Our understanding of SARS-CoV-2 evolution might be enhanced through analysis of intra-host viral mutation rates in specific populations. Viral genome analysis was performed between paired samples and mutations quantified at allele frequencies (AF) ≥ 0.25, ≥ 0.5 and ≥ 0.75. Mutation rate was determined employing F81 and JC69 evolution models and compared between isolates with (ΔNSP-14) and without (wtNSP-14) non-synonymous mutations in NSP-14 and by patient comorbidity. Forty paired samples with median interval of 13 days [IQR 8.5-20] were analyzed. The estimated mutation rate by F81 modeling was 93.6 (95%CI 90.8-96.4], 40.7 (95%CI 38.9-42.6) and 34.7 (95%CI 33.0-36.4) substitutions/genome/year at AF ≥ 0.25, ≥ 0.5, ≥ 0.75 respectively. Mutation rate in ΔNSP-14 were significantly elevated at AF ≥ 0.25 vs wtNSP-14. Patients with immune comorbidities had higher mutation rate at all allele frequencies. Intra-host SARS-CoV-2 mutation rates are substantially higher than those reported through population analysis. Virus strains with altered NSP-14 have accelerated mutation rate at low AF. Immunosuppressed patients have elevated mutation rate at all AF. Understanding intra-host virus evolution will aid in current and future pandemic modeling.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Tasa de Mutación , SARS-CoV-2/genética , Pandemias , Mutación , Genoma Viral/genética
6.
Med Sci Monit ; 29: e941953, 2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-37919887

RESUMEN

BACKGROUND Optimizing surgical approaches for robot-assisted partial nephrectomy (RAPN) is vital for better patient outcomes. This retrospective study aimed to examine how visceral fat area (VFA) and body mass index (BMI) correlate with intraoperative complexities, thereby guiding the selection of surgical techniques for RAPN. MATERIAL AND METHODS The study analyzed the medical records of 213 Chinese patients diagnosed with a range of benign and malignant renal neoplasms and treated with RAPN in 2020. Visceral fat area was quantified using computed tomography (CT) scans taken at the umbilical level. Various perioperative indicators, such as demographic details, clinicopathological parameters, operation time, estimated blood loss (EBL), warm ischemic time (WIT), and intraoperative complications, were assessed. RESULTS For the retroperitoneal approach, patients with either visceral obesity or general obesity had longer operation times (P<0.001 and P=0.004) and had a tendency for higher EBL (P=0.003 and P=0.001) compared to non-obese patients. In the transperitoneal approach, those with visceral obesity had significantly longer operation times (P=0.008) than their non-viscerally obese counterparts; however, general obesity showed no impact on operation time (P=0.251). Estimated blood loss was higher for patients with visceral obesity (P=0.004), but no significant difference was noted among those with general obesity (P=0.980). CONCLUSIONS VFA appears to offer predictive advantages over BMI in assessing intraoperative complexities for transperitoneal RAPN. When used in conjunction with BMI, it could serve as a valuable tool in selecting the most appropriate surgical approach for RAPN.


Asunto(s)
Neoplasias Renales , Procedimientos Quirúrgicos Robotizados , Robótica , Humanos , Índice de Masa Corporal , Obesidad Abdominal/complicaciones , Grasa Intraabdominal , Estudios Retrospectivos , Nefrectomía/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Neoplasias Renales/cirugía , Neoplasias Renales/complicaciones , Obesidad/complicaciones , Resultado del Tratamiento
7.
Nano Lett ; 22(18): 7644-7650, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36103637

RESUMEN

Nanoparticle self-assembly enables the generation of complex ordered nanostructures with enhanced properties or new functionalities. However, the ordering is often limited to the micrometer scale with chemical strategies due to the relative weak supramolecular interactions that govern the self-assembly process. Here a physical strategy via temperature-gradient-assisted self-assembly is reported to create three-dimensional (3D) macroscopic ordered nanocomposites with different gradient variations in grain size, constituent content, and crystal orientation. The resulting α-Fe/Pr2Fe14B ordered nanostructure with reverse gradients in both the grain size and α-Fe content exhibits a record-high energy density of about 25 MGOe for isotropic α-Fe/Pr2Fe14B systems, approximately 130% higher than that of its disordered counterpart. Both experiments and micromagnetic simulations demonstrate that creating ordered nanostructures is an alternative approach to develop high-performance permanent-magnet materials. Our findings make a significant step toward creating 3D macroscopic ordered nanostructures and will stimulate the development of ordered nanomaterials.

8.
J Biol Chem ; 297(5): 101344, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34710372

RESUMEN

Conversion of normal prion protein (PrPC) to the pathogenic PrPSc conformer is central to prion diseases such as Creutzfeldt-Jakob disease and scrapie; however, the detailed mechanism of this conversion remains obscure. To investigate how the N-terminal polybasic region of PrP (NPR) influences the PrPC-to-PrPSc conversion, we analyzed two PrP mutants: ΔN6 (deletion of all six amino acids in NPR) and Met4-1 (replacement of four positively charged amino acids in NPR with methionine). We found that ΔN6 and Met4-1 differentially impacted the binding of recombinant PrP (recPrP) to the negatively charged phospholipid 1-palmitoyl-2-oleoylphosphatidylglycerol, a nonprotein cofactor that facilitates PrP conversion. Both mutant recPrPs were able to form recombinant prion (recPrPSc) in vitro, but the convertibility was greatly reduced, with ΔN6 displaying the lowest convertibility. Prion infection assays in mammalian RK13 cells expressing WT or NPR-mutant PrPs confirmed these differences in convertibility, indicating that the NPR affects the conversion of both bacterially expressed recPrP and post-translationally modified PrP in eukaryotic cells. We also found that both WT and mutant recPrPSc conformers caused prion disease in WT mice with a 100% attack rate, but the incubation times and neuropathological changes caused by two recPrPSc mutants were significantly different from each other and from that of WT recPrPSc. Together, our results support that the NPR greatly influences PrPC-to-PrPSc conversion, but it is not essential for the generation of PrPSc. Moreover, the significant differences between ΔN6 and Met4-1 suggest that not only charge but also the identity of amino acids in NPR is important to PrP conversion.


Asunto(s)
Encéfalo/metabolismo , Mutación , Proteínas PrPC/metabolismo , Proteínas PrPSc/metabolismo , Enfermedades por Prión/metabolismo , Animales , Línea Celular , Ratones , Proteínas PrPC/genética , Proteínas PrPSc/genética , Enfermedades por Prión/genética , Conejos
9.
Small ; 18(5): e2105198, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34825459

RESUMEN

Structural design of the solar-absorbing layer has been considered as one of the most direct and effective approaches for improving the solar steam generation performance by maximizing the absorption of sunlight, but great challenges in manipulation simplification and structure controllability still remain. Herein, a polyester (PET) fabric covered with a vertically aligned 3D tower-like ferrosoferric oxide (Fe3 O4 ) array via a convenient magnetically driven spray-coating method is reported, and both the spatial density and height of the Fe3 O4 array are tunable upon spraying time. It shows an extremely high solar absorbance (98.6%) in the entire solar spectrum, which is superior to the corresponding 2D Fe3 O4 structure (91.1%). Combining the obtained 3D Fe3 O4 /PET with a yolk-shell hydrophobic/superhydrophilic modified melamine-formaldehyde (mMF) sponge, the carefully designed and fabricated 3D Fe3 O4 /PET-mMF evaporator can realize a high water evaporation rate of 1.59 kg m-2 h-1 under 1 kW m-2 solar illumination, outperforming most related solar steam generation systems. With the advantages of cost-effectiveness, high evaporation rate, reliable endurance, and structural controllability, this 3D structural design provides an avenue to build up high-performance solar energy-driven water steam generation systems.

10.
J Xray Sci Technol ; 30(3): 531-547, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35253724

RESUMEN

BACKGROUND: In the process of medical images acquisition, the unknown mixed noise will affect image quality. However, the existing denoising methods usually focus on the known noise distribution. OBJECTIVE: In order to remove the unknown real noise in low-dose CT images (LDCT), a two-step deep learning framework is proposed in this study, which is called Noisy Generation-Removal Network (NGRNet). METHODS: Firstly, the output results of L0 Gradient Minimization are used as the labels of a dental CT image dataset to form a pseudo-image pair with the real dental CT images, which are used to train the noise generation network to estimate real noise distribution. Then, for the lung CT images of the LIDC/IDRI database, we migrate the real noise to the noise-free lung CT images, to construct a new almost-real noisy images dataset. Since dental images and lung images are all CT images, this migration can be achieved. The denoising network is trained to realize the denoising of real LDCT for dental images by using this dataset but can extend for any low-dose CT images. RESULTS: To prove the effectiveness of our NGRNet, we conduct experiments on lung CT images with synthetic noise and tooth CT images with real noise. For synthetic noise image datasets, experimental results show that NGRNet is superior to existing denoising methods in terms of visual effect and exceeds 0.13dB in the peak signal-to-noise ratio (PSNR). For real noisy image datasets, the proposed method can achieve the best visual denoising effect. CONCLUSIONS: The proposed method can retain more details and achieve impressive denoising performance.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Tomografía Computarizada por Rayos X , Algoritmos , Bases de Datos Factuales , Procesamiento de Imagen Asistido por Computador/métodos , Relación Señal-Ruido , Tomografía Computarizada por Rayos X/métodos
11.
Langmuir ; 37(31): 9630-9636, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34333978

RESUMEN

Multifunctional surfaces that are favorable for both droplet nucleation and removal are critical for water-harvesting applications, but there still remain great challenges. Herein, we proposed a facile strategy to construct hydrophobic surfaces containing moderate hydrophilic groups to achieve both exceptional droplet nucleation and removal. Different from natural desert beetle-inspired water-harvesting materials, these surfaces utilize limited hydrophilic domains to condense fog, and transport of formed tiny droplets relies on a hydrophobic background. The total surface area of the presented hydrophobic fabric contains hydrophilic groups, and the areas for trapping fog have increased. This feature is optimized to enhance the droplet nucleation density, and the surface still has excellent liquid repellency, resulting in maximum water collection efficiency of the prepared surface reaching up to 3.145 g·cm-2·h-1, much higher than the most reported water-harvesting materials. Due to its high efficiency and scalability, we believe that the proposed strategy to construct hydrophobic surfaces containing hydrophilic groups has great practical value.

12.
Eur J Clin Microbiol Infect Dis ; 40(6): 1325-1328, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33411171

RESUMEN

To measure the seroprevalence of high-exposure populations in brucellosis endemic areas and report the outcome and duration of seropositive asymptomatic subjects, we screened 595 family members of shepherds in Jilin Province, China and then followed up 15 seropositive asymptomatic subjects for 18 months. We found that the seropositive rate of 15.5%. Nearly half of seropositive asymptomatic subjects (7/15) developed into brucellosis in the short term; others were still seropositive asymptomatic or had decreased SAT titer in a longer time.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Zoonosis Bacterianas/sangre , Brucella/inmunología , Brucelosis/sangre , Adolescente , Adulto , Anciano , Animales , Enfermedades Asintomáticas/epidemiología , Zoonosis Bacterianas/epidemiología , Zoonosis Bacterianas/transmisión , Brucella/aislamiento & purificación , Brucelosis/diagnóstico , Brucelosis/epidemiología , Brucelosis/transmisión , Niño , China/epidemiología , Estudios Transversales , Familia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Ovinos , Enfermedades de las Ovejas/microbiología , Adulto Joven
13.
Chem Rev ; 118(2): 839-885, 2018 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-29048888

RESUMEN

The replacement of current petroleum-based plastics with sustainable alternatives is a crucial but formidable challenge for the modern society. Catalysis presents an enabling tool to facilitate the development of sustainable polymers. This review provides a system-level analysis of sustainable polymers and outlines key criteria with respect to the feedstocks the polymers are derived from, the manner in which the polymers are generated, and the end-of-use options. Specifically, we define sustainable polymers as a class of materials that are derived from renewable feedstocks and exhibit closed-loop life cycles. Among potential candidates, aliphatic polyesters and polycarbonates are promising materials due to their renewable resources and excellent biodegradability. The development of renewable monomers, the versatile synthetic routes to convert these monomers to polyesters and polycarbonate, and the different end-of-use options for these polymers are critically reviewed, with a focus on recent advances in catalytic transformations that lower the technological barriers for developing more sustainable replacements for petroleum-based plastics.

14.
Small ; 14(22): e1800619, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29718577

RESUMEN

The precise control of individual components in multicomponent nanostructures is crucial to realizing their fascinating functionalities for applications in electronics, energy-conversion devices, and biotechnologies. However, this control remains particularly challenging for bulk, multicomponent nanomaterials because the desired structures of the constitute components often conflict. Herein, a strategy is reported for simultaneously controlling the structural properties of the constituent components in bulk multicomponent nanostructures through layered structural design. The power of this approach is illustrated by generating the desired structures of each constituent in a bulk multicomponent nanomaterial (SmCo + FeCo)/NdFeB, which cannot be attained with existing methods. The resulting nanostructure exhibits a record high energy density (31 MGOe) for this class of bulk nanocomposites composed of both hard and soft magnetic materials, with the soft magnetic fraction exceeding 20 wt%. It is anticipated that other properties beyond magnetism, such as the thermoelectric and mechanical properties, can also be tuned by engineering such layered architectures.

15.
Nano Lett ; 17(5): 2985-2993, 2017 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-28402670

RESUMEN

Hybrid nanostructures that comprise two or more nanoscale functional components are fascinating for applications in electronics, energy conversion devices, and biotechnologies. Their performances are strongly dependent on the characteristics of the individual components including the size, morphology, orientation, and distribution. However, it remains challenging to simultaneously control these structural properties in a three-dimensional (3D) hybrid nanostructure. Here, we introduce a robust strategy for concurrently manipulating these characteristics in a bulk SmCo/Fe(Co) nanocomposite. This method can tune nanocrystals in size (down to sub-10 nm), morphology (sphere, rod, or disc), and crystallographic orientation (isotropic or anisotropic). We have therefore achieved the desired nanostructures: oriented hard magnetic SmCo grains and homogeneously distributed soft magnetic Fe(Co) grains with high fractions (∼26 wt %) and small sizes (∼12.5 nm). The resulting anisotropic nanocomposite exhibits an energy product that is approximately 50% greater than that of its corresponding pure SmCo magnet and 35% higher than the reported largest value in isotropic SmCo/Fe(Co) systems. Our findings pave a new way to manipulating 3D hybrid nanostructures in a controllable manner.

16.
J Am Chem Soc ; 139(10): 3822-3833, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-28244754

RESUMEN

The use of dithiolane-containing polymers to construct responsive and dynamic networks is an attractive strategy in material design. Here, we provide a detailed mechanistic study on the self-assembly and gelation behavior of a class of ABA triblock copolymers containing a central poly(ethylene oxide) block and terminal polycarbonate blocks with pendant 1,2-dithiolane functionalities. In aqueous solution, these amphiphilic block copolymers self-assemble into bridged flower micelles at high concentrations. The addition of a thiol initiates the reversible ring-opening polymerizations of dithiolanes in the micellar cores to induce the cross-linking and gelation of the micellar network. The properties of the resulting hydrogels depend sensitively on the structures of 1,2-dithiolanes. While the methyl asparagusic acid-derived hydrogels are highly dynamic, adaptable, and self-healing, those derived from lipoic acid are rigid, resilient, and brittle. The thermodynamics and kinetics of ring-opening polymerization of the two dithiolanes were investigated to provide important insights on the dramatically different properties of the hydrogels derived from the two different dithiolanes. The incorporation of both dithiolane monomers into the block copolymers provides a facile way to tailor the properties of these hydrogels.

17.
Nano Lett ; 16(9): 5631-8, 2016 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-27570896

RESUMEN

Core/shell nanostructures are fascinating for many advanced applications including strong permanent magnets, magnetic recording, and biotechnology. They are generally achieved via chemical approaches, but these techniques limit them to nanoparticles. Here, we describe a three-dimensional (3D) self-assembly of core/shell-like nanocomposite magnets, with hard-magnetic Nd2Fe14B core of ∼45 nm and soft-magnetic α-Fe shell of ∼13 nm, through a physical route. The resulting Nd2Fe14B/α-Fe core/shell-like nanostructure allows both large remanent magnetization and high coercivity, leading to a record-high energy product of 25 MGOe which reaches the theoretical limit for isotropic Nd2Fe14B/α-Fe nanocomposite magnets. Our approach is based on a sequential growth of the core and shell nanocrystals in an alloy melt. These results make an important step toward fabricating core/shell-like nanostructure in 3D materials.

18.
Angew Chem Int Ed Engl ; 56(51): 16357-16362, 2017 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-29080292

RESUMEN

Template-free fabrication of non-spherical polymeric nanoparticles is desirable for various applications, but has had limited success owing to thermodynamic favorability of sphere formation. Herein we present a simple way to prepare cubic nanoparticles of block copolymers by self-assembly from aqueous solutions at room temperature. Nanocubes with edges of 40-200 nm are formed spontaneously on different surfaces upon water evaporation from micellar solutions of triblock copolymers containing a central poly(ethylene oxide) block and terminal trimethylene carbonate/dithiolane blocks. These polymers self-assemble into 28±5 nm micelles in water. Upon drying, micelle aggregation and a kinetically controlled crystallization of central blocks evidently induce solid cubic particle formation. An approach for preserving the structures of these cubes in water by thiol- or photo-induced crosslinking was developed. The ability to solubilize a model hydrophobic drug, curcumin, was also explored.

19.
Pak J Pharm Sci ; 29(2): 415-21, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27087089

RESUMEN

In many industrialized countries, clinical pharmacy has developed into a separate discipline and become a vital part of inpatient care in hospitals. However, as compared to many established branches of medicine, clinical pharmacy is still in its infancy, with much room for growth, improvement, and recognition by both the medical community and patients. In this study, a widely-recognized development strategy analysis tool, Strength, Weakness, Opportunity and Threat (SWOT), was used to systematically address several key issues to the development of clinical pharmacy in China. This analysis aims to provide feasible recommendations for the development of clinical pharmacy in China by identifying current problems and growth opportunities. Full development of clinical pharmacy as a mature clinical discipline will help promote the rational use of drugs by both clinicians and patients and lead to enhanced drug efficacy and safety.


Asunto(s)
Atención a la Salud/tendencias , Farmacéuticos/tendencias , Servicio de Farmacia en Hospital/tendencias , China , Competencia Clínica , Atención a la Salud/normas , Educación en Farmacia/tendencias , Predicción , Humanos , Farmacéuticos/normas , Servicio de Farmacia en Hospital/normas , Mejoramiento de la Calidad/tendencias , Indicadores de Calidad de la Atención de Salud/tendencias
20.
J Am Chem Soc ; 137(17): 5650-3, 2015 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-25917449

RESUMEN

The design and generation of adaptable materials derived from structurally dynamic polymers provides a strategy for generating smart materials that can respond to environmental stimuli or exhibit self-healing behavior. Herein we report an expedient organocatalytic ring-opening polymerization of cyclic carbonates containing pendant dithiolanes (trimethylene carbonate/dithiolane, TMCDT) from poly(ethylene oxide) diols to generate water-soluble triblock (ABA) copolymers containing a central poly(ethylene oxide) block and terminal dithiolane blocks. Hydrogels generated from the triblock copolymers and a cross-linking dithiol exhibited dynamic behavior as a result of the reversible ring opening of the pendant 1,2-dithiolanes. These materials exhibit self-healing behavior, can be injected through a syringe, and rapidly recover their mechanical properties after a severe strain deformation. The dynamic properties of these gels can be modulated with the number of dithiolane units, pH, and temperature.

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