Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 370
Filtrar
Más filtros

País/Región como asunto
Intervalo de año de publicación
1.
Nature ; 582(7810): 55-59, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32494077

RESUMEN

The ability of superhydrophobic surfaces to stay dry, self-clean and avoid biofouling is attractive for applications in biotechnology, medicine and heat transfer1-10. Water droplets that contact these surfaces must have large apparent contact angles (greater than 150 degrees) and small roll-off angles (less than 10 degrees). This can be realized for surfaces that have low-surface-energy chemistry and micro- or nanoscale surface roughness, minimizing contact between the liquid and the solid surface11-17. However, rough surfaces-for which only a small fraction of the overall area is in contact with the liquid-experience high local pressures under mechanical load, making them fragile and highly susceptible to abrasion18. Additionally, abrasion exposes underlying materials and may change the local nature of the surface from hydrophobic to hydrophilic19, resulting in the pinning of water droplets to the surface. It has therefore been assumed that mechanical robustness and water repellency are mutually exclusive surface properties. Here we show that robust superhydrophobicity can be realized by structuring surfaces at two different length scales, with a nanostructure design to provide water repellency and a microstructure design to provide durability. The microstructure is an interconnected surface frame containing 'pockets' that house highly water-repellent and mechanically fragile nanostructures. This surface frame acts as 'armour', preventing the removal of the nanostructures by abradants that are larger than the frame size. We apply this strategy to various substrates-including silicon, ceramic, metal and transparent glass-and show that the water repellency of the resulting superhydrophobic surfaces is preserved even after abrasion by sandpaper and by a sharp steel blade. We suggest that this transparent, mechanically robust, self-cleaning glass could help to negate the dust-contamination issue that leads to a loss of efficiency in solar cells. Our design strategy could also guide the development of other materials that need to retain effective self-cleaning, anti-fouling or heat-transfer abilities in harsh operating environments.


Asunto(s)
Interacciones Hidrofóbicas e Hidrofílicas , Propiedades de Superficie , Incrustaciones Biológicas/prevención & control , Agua/química
2.
Nature ; 578(7795): 392-396, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32025037

RESUMEN

Extensive efforts have been made to harvest energy from water in the form of raindrops1-6, river and ocean waves7,8, tides9 and others10-17. However, achieving a high density of electrical power generation is challenging. Traditional hydraulic power generation mainly uses electromagnetic generators that are heavy, bulky, and become inefficient with low water supply. An alternative, the water-droplet/solid-based triboelectric nanogenerator, has so far generated peak power densities of less than one watt per square metre, owing to the limitations imposed by interfacial effects-as seen in characterizations of the charge generation and transfer that occur at solid-liquid1-4 or liquid-liquid5,18 interfaces. Here we develop a device to harvest energy from impinging water droplets by using an architecture that comprises a polytetrafluoroethylene film on an indium tin oxide substrate plus an aluminium electrode. We show that spreading of an impinged water droplet on the device bridges the originally disconnected components into a closed-loop electrical system, transforming the conventional interfacial effect into a bulk effect, and so enhancing the instantaneous power density by several orders of magnitude over equivalent devices that are limited by interfacial effects.

3.
Proc Natl Acad Sci U S A ; 120(32): e2305567120, 2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37527348

RESUMEN

When a water drop is placed on a hot solid surface, it either undergoes explosive contact boiling or exhibits a stable state. In the latter case, the drop floats over an insulating layer of vapor generated by rapid vaporization of water at the surface/drop interface; this is known as the Leidenfrost state. Here, we discuss a previously unrecognized steady state in which a water drop "stands" on a hot smooth surface. In this state, the drop stabilizes itself with partial adhesion on the hot surface, leading to unique deformation and rotation behavior reminiscent of Sufi whirling-a form of spinning dance. Our analysis of this standing Leidenfrost state reveals the underlying mechanisms that drive the drop's stable partial adhesion and subsequent deformation with rotation. The heat-transfer efficiency of this standing state is up to 390% greater than that of the traditional floating Leidenfrost state.

4.
Rev Med Virol ; 34(1): e2500, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38126937

RESUMEN

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously producing new variants, necessitating effective therapeutics. Patients are not only confronted by the immediate symptoms of infection but also by the long-term health issues linked to long COVID-19. Activation of epidermal growth factor receptor (EGFR) signalling during SARS-CoV-2 infection promotes virus propagation, mucus hyperproduction, and pulmonary fibrosis, and suppresses the host's antiviral response. Over the long term, EGFR activation in COVID-19, particularly in COVID-19-induced pulmonary fibrosis, may be linked to the development of lung cancer. In this review, we have summarised the significance of EGFR signalling in the context of SARS-CoV-2 infection. We also discussed the targeting of EGFR signalling as a promising strategy for COVID-19 treatment and highlighted erlotinib as a superior option among EGFR inhibitors. Erlotinib effectively blocks EGFR and AAK1, thereby preventing SARS-CoV-2 replication, reducing mucus hyperproduction, TNF-α expression, and enhancing the host's antiviral response. Nevertheless, to evaluate the antiviral efficacy of erlotinib, relevant clinical trials involving an appropriate patient population should be designed.


Asunto(s)
COVID-19 , Receptores ErbB , Transducción de Señal , Humanos , Antivirales/uso terapéutico , Antivirales/farmacología , Tratamiento Farmacológico de COVID-19 , Receptores ErbB/genética , Receptores ErbB/metabolismo , Clorhidrato de Erlotinib/uso terapéutico , Síndrome Post Agudo de COVID-19 , Fibrosis Pulmonar/metabolismo , SARS-CoV-2/metabolismo , Transducción de Señal/efectos de los fármacos
5.
BMC Plant Biol ; 24(1): 628, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38961375

RESUMEN

BACKGROUND: Cyperus stoloniferus is an important species in coastal ecosystems and possesses economic and ecological value. To elucidate the structural characteristics, variation, and evolution of the organelle genome of C. stoloniferus, we sequenced, assembled, and compared its mitochondrial and chloroplast genomes. RESULTS: We assembled the mitochondrial and chloroplast genomes of C. stoloniferus. The total length of the mitochondrial genome (mtDNA) was 927,413 bp, with a GC content of 40.59%. It consists of two circular DNAs, including 37 protein-coding genes (PCGs), 22 tRNAs, and five rRNAs. The length of the chloroplast genome (cpDNA) was 186,204 bp, containing 93 PCGs, 40 tRNAs, and 8 rRNAs. The mtDNA and cpDNA contained 81 and 129 tandem repeats, respectively, and 346 and 1,170 dispersed repeats, respectively, both of which have 270 simple sequence repeats. The third high-frequency codon (RSCU > 1) in the organellar genome tended to end at A or U, whereas the low-frequency codon (RSCU < 1) tended to end at G or C. The RNA editing sites of the PCGs were relatively few, with only 9 and 23 sites in the mtDNA and cpDNA, respectively. A total of 28 mitochondrial plastid DNAs (MTPTs) in the mtDNA were derived from cpDNA, including three complete trnT-GGU, trnH-GUG, and trnS-GCU. Phylogeny and collinearity indicated that the relationship between C. stoloniferus and C. rotundus are closest. The mitochondrial rns gene exhibited the greatest nucleotide variability, whereas the chloroplast gene with the greatest nucleotide variability was infA. Most PCGs in the organellar genome are negatively selected and highly evolutionarily conserved. Only six mitochondrial genes and two chloroplast genes exhibited Ka/Ks > 1; in particular, atp9, atp6, and rps7 may have undergone potential positive selection. CONCLUSION: We assembled and validated the mtDNA of C. stoloniferus, which contains a 15,034 bp reverse complementary sequence. The organelle genome sequence of C. stoloniferus provides valuable genomic resources for species identification, evolution, and comparative genomic research in Cyperaceae.


Asunto(s)
Cyperus , Genoma del Cloroplasto , Genoma Mitocondrial , Cyperus/genética , Filogenia , Tolerancia a la Sal/genética , Plantas Tolerantes a la Sal/genética , Composición de Base , Álcalis
6.
Opt Express ; 32(10): 16611-16628, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38858863

RESUMEN

A scheme for high-efficiency transfer of optical vortices is proposed by an inelastic two-wave mixing (ITWM) process in an inverted-Y four-level atomic medium, which is originally prepared in a coherent superposition of two ground states. The orbital angular momentum (OAM) information in the incident vortex probe field can be transferred to the generated signal field through the ITWM process. Choosing reasonable experimentally realizable parameters, we find that the presence of the off-resonance control field can greatly improve the conversion efficiency of optical vortices, rather than in the absence of a control field. This is caused by the broken of the destructive interference between two one-photon excitation pathways. Furthermore, we also extend our model to an inelastic multi-wave mixing process and demonstrate that the transfer efficiency between multiple optical vortices strongly depends on the superposition of the ground states. Finally, we explore the composite vortex beam generated by collinear superposition of the incident vortex probe and signal fields. It is obvious that the intensity and phase profiles of the composite vortex can be effectively controlled via adjusting the intensity of the control field. Potential applications of our scheme may exist in OAM-based optical communications and optical information processing.

7.
Opt Express ; 32(12): 21102-21120, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38859473

RESUMEN

This study investigates the macroscopic and optical properties of cirrus clouds in the 32N region from July 2016 to May 2017, leveraging data from ground-based lidar observations and CALIOP to overcome the inconsistencies in detected cirrus cloud samples. Through extensive data analysis, statistical characteristics of cirrus clouds were discerned, revealing lidar ratio values of 28.5 ± 10.8 from ground-based lidar and 27.4 ± 11.2 from CALIOP. Validation with a decade of CALIOP data (2008-2018) confirmed these findings, presenting a consistent lidar ratio of 27.4 ± 12.0. A significant outcome of the analysis was the identification of a positive correlation between the lidar ratio and cloud centroid temperature, indicating a gradual decrease in the lidar ratio as temperatures dropped. The study established a fundamental consistency in their macroscopic properties, including cloud base height, cloud top height, cloud thickness, cloud centroid height, and cloud centroid temperature. The results for ground-based lidar (CALIOP) are: 10.0 ± 2.1 km (10.0 ± 2.2 km), 11.8 ± 2.1 km (11.5 ± 2.3 km), 1.87 ± 0.83 km (1.52 ± 0.71 km), and 10.5 ± 2.2 km, -46.9 ± 9.7°C (-47.1 ± 10.0°C).These properties exhibited seasonal variations, with cirrus clouds reaching higher altitudes in summer and lower in winter, influenced by the height of the tropopause. The optical properties of cirrus clouds were also analyzed, showing an annual average optical depth of 0.31 ± 0.35 for ground-based lidar and 0.32 ± 0.44 for CALIOP. The study highlighted the distribution of subvisible, thin, and thick cirrus clouds, with a notable prevalence of subvisible clouds during summer, suggesting their frequent formation above 14 km. Furthermore, the study observed linear growth in geometric thickness and optical depth up to 2.5 km from CALIOP and 2.9 km from ground-based lidar. Maximum optical depth was observed at cloud centroid temperatures of -35°C for CALIOP and -40°C for ground-based lidar, with optical depth decreasing as temperatures fell. This suggests that fully glaciated cirrus clouds exhibit the highest optical depth at warmer temperatures, within the complete glaciation temperature range of -35°C to -40°C.

8.
J Biol Chem ; 298(2): 101584, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35032548

RESUMEN

With the outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), coronaviruses have begun to attract great attention across the world. Of the known human coronaviruses, however, Middle East respiratory syndrome coronavirus (MERS-CoV) is the most lethal. Coronavirus proteins can be divided into three groups: nonstructural proteins, structural proteins, and accessory proteins. While the number of each of these proteins varies greatly among different coronaviruses, accessory proteins are most closely related to the pathogenicity of the virus. We found for the first time that the ORF3 accessory protein of MERS-CoV, which closely resembles the ORF3a proteins of severe acute respiratory syndrome coronavirus and SARS-CoV-2, has the ability to induce apoptosis in cells in a dose-dependent manner. Through bioinformatics analysis and validation, we revealed that ORF3 is an unstable protein and has a shorter half-life in cells compared to that of severe acute respiratory syndrome coronavirus and SARS-CoV-2 ORF3a proteins. After screening, we identified a host E3 ligase, HUWE1, that specifically induces MERS-CoV ORF3 protein ubiquitination and degradation through the ubiquitin-proteasome system. This results in the diminished ability of ORF3 to induce apoptosis, which might partially explain the lower spread of MERS-CoV compared to other coronaviruses. In summary, this study reveals a pathological function of MERS-CoV ORF3 protein and identifies a potential host antiviral protein, HUWE1, with an ability to antagonize MERS-CoV pathogenesis by inducing ORF3 degradation, thus enriching our knowledge of the pathogenesis of MERS-CoV and suggesting new targets and strategies for clinical development of drugs for MERS-CoV treatment.


Asunto(s)
Apoptosis , Infecciones por Coronavirus/metabolismo , Coronavirus del Síndrome Respiratorio de Oriente Medio/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Proteínas no Estructurales Virales/metabolismo , Células A549 , Línea Celular , Biología Computacional , Infecciones por Coronavirus/fisiopatología , Infecciones por Coronavirus/virología , Células Epiteliales/fisiología , Células Epiteliales/virología , Células HEK293 , Interacciones Huésped-Patógeno , Humanos
9.
J Virol ; 96(17): e0074122, 2022 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-35980206

RESUMEN

Within the past 2 decades, three highly pathogenic human coronaviruses have emerged, namely, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The health threats and economic burden posed by these tremendously severe coronaviruses have paved the way for research on their etiology, pathogenesis, and treatment. Compared to SARS-CoV and SARS-CoV-2, MERS-CoV genome encoded fewer accessory proteins, among which the ORF4b protein had anti-immunity ability in both the cytoplasm and nucleus. Our work for the first time revealed that ORF4b protein was unstable in the host cells and could be degraded by the ubiquitin proteasome system. After extensive screenings, it was found that UBR5 (ubiquitin protein ligase E3 component N-recognin 5), a member of the HECT E3 ubiquitin ligases, specifically regulated the ubiquitination and degradation of ORF4b. Similar to ORF4b, UBR5 can also translocate into the nucleus through its nuclear localization signal, enabling it to regulate ORF4b stability in both the cytoplasm and nucleus. Through further experiments, lysine 36 was identified as the ubiquitination site on the ORF4b protein, and this residue was highly conserved in various MERS-CoV strains isolated from different regions. When UBR5 was knocked down, the ability of ORF4b to suppress innate immunity was enhanced and MERS-CoV replication was stronger. As an anti-MERS-CoV host protein, UBR5 targets and degrades ORF4b protein through the ubiquitin proteasome system, thereby attenuating the anti-immunity ability of ORF4b and ultimately inhibiting MERS-CoV immune escape, which is a novel antagonistic mechanism of the host against MERS-CoV infection. IMPORTANCE ORF4b was an accessory protein unique to MERS-CoV and was not present in SARS-CoV and SARS-CoV-2 which can also cause severe respiratory disease. Moreover, ORF4b inhibited the production of antiviral cytokines in both the cytoplasm and the nucleus, which was likely to be associated with the high lethality of MERS-CoV. However, whether the host proteins regulate the function of ORF4b is unknown. Our study first determined that UBR5, a host E3 ligase, was a potential host anti-MERS-CoV protein that could reduce the protein level of ORF4b and diminish its anti-immunity ability by inducing ubiquitination and degradation. Based on the discovery of ORF4b-UBR5, a critical molecular target, further increasing the degradation of ORF4b caused by UBR5 could provide a new strategy for the clinical development of drugs for MERS-CoV.


Asunto(s)
Infecciones por Coronavirus , Interacciones Microbiota-Huesped , Coronavirus del Síndrome Respiratorio de Oriente Medio , Proteolisis , Ubiquitina-Proteína Ligasas , Ubiquitinación , Proteínas Virales , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Citocinas/inmunología , Humanos , Inmunidad Innata , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Coronavirus del Síndrome Respiratorio de Oriente Medio/metabolismo , Terapia Molecular Dirigida , Complejo de la Endopetidasa Proteasomal/metabolismo , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , SARS-CoV-2 , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinas/metabolismo , Proteínas Virales/química , Proteínas Virales/metabolismo , Replicación Viral
10.
Org Biomol Chem ; 21(3): 639-643, 2023 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-36562387

RESUMEN

The divergent dehydrogenative coupling reactions of tryptamines with the catalysis of nontoxic FeIII salts in the presence of DDQ as the co-oxidant have been developed. Remarkably, the transformations feature a rapid and regioselective assembly of diverse 2,8'- and N1,8'-bis(indolyl) methane derivatives from readily-available starting materials by simply changing the FeIII salt and reaction temperature. Besides, the fast reaction rate, mild reaction conditions, low catalyst cost and easy operations make this methodology quite useful. The synthetic utility was further demonstrated in the biomimetic synthesis of 6,6'-bis-(debromo)-gelliusine F.


Asunto(s)
Compuestos Férricos , Metano , Biomimética , Indoles , Catálisis
11.
Appl Microbiol Biotechnol ; 107(2-3): 543-552, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36504328

RESUMEN

While previous studies mainly focused on the total number of spores as an index to predict the calcium precipitation activity (CPA) of bacterial strains, the effect of viability of spores on microbial-induced calcium precipitation (MICP) has remained highly ignored. Therefore, for the first time, we have attempted to optimize the sporulation process in terms of viable spore production and, most importantly, aimed to build a correlation between viable spores and CPA. The results have shown that for the sporulation of Bacillus sp. H4, starch and peptone are the optimal carbon and nitrogen sources, respectively. One gram per liter of sodium chloride promotes CPA and production of viable spores, whereas an increase of sodium chloride concentration beyond 8 g L-1 significantly reduces CPA without reducing the quantity of viable spores. Exogenous conditions such as seed age, inoculation quantity, and liquid volume only pose slight influence on the sporulation and CPA. Conclusively, the spores produced under optimized conditions are more morphologically uniform and display a 20% increase in CPA compared to pre-optimized spores. Furthermore, by combining the results of heatmap analysis, it can be concluded that not only the quantity, but also the quality of viable spores is important for bacterial strain to develop high CPA and effective MICP process. This study sheds light on the breadth of biomineralization activity based on viable spores and is an imperative step toward the intelligible design of MICP-based engineering solutions. KEY POINTS: • Viability of spores is a key controlling factor in calcium precipitation activity (CPA). • Spores produced under optimized conditions display a 20% increase in CPA. • Quality of viable spores is imperative for bacterial strains to develop high CPA.


Asunto(s)
Bacillus , Carbonato de Calcio , Calcio , Cloruro de Sodio , Esporas Bacterianas , Bacterias , Precipitación Química , Viabilidad Microbiana
12.
J Sci Food Agric ; 103(6): 2889-2903, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36377380

RESUMEN

BACKGROUND: 3D printing provides a new way of molding chocolate with complex geometrical structures. The screw extruder can efficiently transport the liquid chocolate, which has been adopted to investigate the effect of the profile of the screw flight on the flow. First, the rheological behavior of the liquid chocolate is measured and the Cross equation is demonstrated as the proper rheological model. Then, based on the rheological behavior, an improved lattice Boltzmann method is creatively proposed, for which the effectiveness is validated by the classical Poiseuille flow. Third, the geometrical structure of the screw extruder is analyzed and transformed. The possible changes in the profiles of the screw flights are listed. Finally, the fluid analysis is conducted and the necessary streamlines figures, cloud charts and velocity distributions are obtained. RESULTS: The large dip angle in straight cases has an obvious effect on the velocity distribution and the common flow area. The position of the convex point is the additional important factor, whereas the concave profiles are the most moderate in the proposed cases. CONCLUSION: The changes in the profiles will affect the chocolate flow. The work is significant for extrusion theory in 3D printing. © 2022 Society of Chemical Industry.


Asunto(s)
Cacao , Chocolate , Impresión Tridimensional , Reología
13.
J Sci Food Agric ; 103(9): 4257-4267, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36224106

RESUMEN

The prevalence of type 2 diabetes has been growing at an increasing rate worldwide. Dietary therapy is probably the easiest and least expensive method to prevent and treat diabetes. Previous studies have reported that coarse grains have anti-diabetic effects. Although considerable efforts have been made on the anti-diabetic function of different grains, the mechanisms of coarse grains on type 2 diabetes have not been systematically compared and summarized so far. Intestinal flora, reported as the main 'organ' of action underlying coarse grains, is an important factor in the alleviation of type 2 diabetes by coarse grains. Furthermore, microRNA (miRNA), as a new disease marker and 'dark nutrient', plays a likely influential role in cross-border communication among coarse grains, intestinal flora, and hosts. Given this context, this article reviews several possible mechanisms for the role of coarse grains on diabetes, incorporating resistance to inflammation and oxidative stress, repair of insulin signaling and ß-cell dysfunction, and highlights the regulation of intestinal flora disorders and miRNAs expression, along with some novel insights. © 2022 Society of Chemical Industry.


Asunto(s)
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , MicroARNs , Humanos , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/prevención & control , MicroARNs/genética , Insulina , Dieta
14.
Small ; 18(32): e2203057, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35843880

RESUMEN

Liquid lubricant of low affinity makes slippery coatings widely used in lubricating, anti-biofouling, anti-icing, fluid guiding, and drag reduction. Two critical challenges, however, remain in the practical application of slippery coatings consisting of liquid lubricants: (1) universality regardless of roughness and chemical composition of substrates, (2) stability of surface lubricity against evaporation. Herein, a chemical method is reported to create a universal and stable slippery lubricant-adhesive cooperated coating (SLACC) through acid catalyzed dehydration reaction between the phenolic hydroxyl of polydopamine (PDA), with universal (for challenge-1) and strong (for challenge-2) adhesion properties, and liquid-like polydimethylsiloxane (PDMS), with lubricant properties. Through overlying PDMS on PDA, a spatial gradient interpenetration of chemical combined PDA and PDMS leaving lubricant PDMS at the outermost of coating is achieved. This structure contributes to the following performances of SLACC: nearly universality suitable for 100 different abiotic or biotic substrates and stability sustainable for long-term usages, UV radiating, refrigerating, hot air drying, freeze drying, knife scratch and abrasion. This proposed strategy is envisioned anti-fouling from plane to tube and exhibits drag reduction in confined space.


Asunto(s)
Incrustaciones Biológicas , Lubricantes , Adhesivos , Lubricantes/química
15.
Opt Lett ; 47(22): 5758-5761, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37219096

RESUMEN

The orbital angular momentum (OAM) of light is particularly promising for multi-channel data transmission in optical fiber communications. In the implementation, one of the impediments is the lack of an effective all-fiber method to demultiplex and filter OAM modes. To solve the problem, by utilizing the inherent spiral characteristics of a chiral long-period fiber grating (CLPG), we propose and demonstrate experimentally a CLPG-based scheme for filtering spin-entangled OAM of photons. We unveil theoretically and verify experimentally that the co-handed OAM with the same chirality of helical phase wavefront as CLPG couples to higher-order cladding modes and suffers loss, while the cross-handed OAM with the opposite chirality freely passes in CLPG. Meanwhile, by combining its grating characteristics, CLPG can realize the filtering and detection of a spin-entangled OAM with arbitrary order and chirality without exerting extra loss for other OAM. Our work has great potential in analyzing and manipulating spin-entangled OAM, paving the way for the development of all-fiber OAM applications.

16.
Biotechnol Appl Biochem ; 69(5): 2008-2016, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34605559

RESUMEN

This study reports the increment in the secondary metabolites in Stevia rebaudiana plant after exposure to the elimination of Ca and Mg from Murashige and Skoog culture medium. The effect of nutrient stress on regenerants of S. rebaudiana is measured, which reveals significantly enhanced growth parameters, steviol glycosides (SGs) content, and nonenzymatic antioxidants; total phenolic content, total flavonoid content, total antioxidant capacity, total reducing power, and DPPH-free radical scavenging activity as compared with the control treatment. However, significantly highest amounts are obtained in a medium with only Ca deficiency. The amount of rebaudioside A (Reb A) and stevioside (ST) obtained in the case of Ca-deficient medium is 4.08 and 0.69%, respectively. It is followed by the results obtained from both Ca- and Mg-deprived medium [Reb A (3.23%) and ST (0.52%)] and the lowest values are obtained from medium lacking Mg only [Reb A (2.60%) and ST (0.40%)]. The most probable adaptation mechanism might be the production of reactive oxygen species by nutrients' stress, which results in secondary metabolites production as defensive moieties to overcome stress situation. This effective protocol needs to be refined to apply on an industrial scale in bioreactors for increasing quantities of commercially important pharmaceutical compounds.


Asunto(s)
Stevia , Stevia/metabolismo , Magnesio/metabolismo , Calcio/metabolismo , Biomasa , Hojas de la Planta/metabolismo , Antioxidantes/farmacología , Preparaciones Farmacéuticas
17.
BMC Med Imaging ; 22(1): 27, 2022 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-35151256

RESUMEN

BACKGROUND: Microwave ablation (MWA) is a popular therapy for liver malignant tumor in recent years. Few studies have been conducted on its use in the treatment of hepatic alveolar echinococcosis (HAE). The study aims to evaluate the efficacy and safety of MWA in the treatment of HAE. METHODS: This study analyzed the data of 45 patients (mean age, 38 ± 2 years; 24 males) diagnosed with HAE and underwent MWA treatment between June 2014 to December 2019. The patients after MWA were examined by CT or MRI [follow-up: 32 months (IQR 23-48.5)] to determine whether the lesions were relapsed and to evaluate the therapeutic effect of MWA. The safety of MWA was evaluated by monitoring postoperative complications. Clinical data, such as patient demographics, imaging features of the lesions, relevant findings of laboratory tests before and after ablation, and information related to ablation, were collected and analyzed. Paired-sample t tests and paired-sample Wilcoxon signed-rank tests were used to compare relevant laboratory indicators before and after MWA. RESULTS: MWA was applied to 57 HAE lesions in 45 patients. The median size of lesions was 3.42 cm (IQR2.85-4.41). The rate of complete ablation was 100% (57/57). The median follow-up time was 32 months (IQR 23-48.5). The recurrence rate was 13% (6/45), and the median time of recurrence was 22 months. The rate of minor complications was 11.1% (5/45), and there were no major complications and deaths. Compared to preoperative, ALB, RBC, HBG, and PLT were decreased (p < 0.001); ALT, TB, DB, and WBC were increased (p < 0.001); and no statistically difference in PT, APTT, and INR (p > 0.05). CONCLUSIONS: MWA might be a safe and effective way to cure HAE. Meanwhile, it provides a new option and a new way of thinking about treatment for patients with HAE.


Asunto(s)
Ablación por Catéter/métodos , Equinococosis Hepática/cirugía , Ultrasonografía Intervencional , Adulto , Ablación por Catéter/efectos adversos , Equinococosis Hepática/diagnóstico por imagen , Femenino , Humanos , Hígado/diagnóstico por imagen , Hígado/cirugía , Masculino , Microondas
18.
BMC Geriatr ; 22(1): 928, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36457103

RESUMEN

OBJECTIVE: The aim of this study was to investigate the relationship between the Chang reduction quality criteria (CRQC) and the outcome of intertrochanteric fractures in older adults according to follow-up time. METHODS: This was a retrospective analysis of 389 older adult patients with intertrochanteric fractures treated surgically from January 2019 to June 2021, including 130 males and 259 females aged 84.6 (77.5-89.7) years. Patient survival was determined by telephone as the time between admission to hospital for fracture and death or until the study deadline (June 1, 2022). According to the CRQC, the patients were divided into the Poor, Acceptable, and Excellent groups. Univariate and multivariate Cox proportional hazard models were used to assess the association between CRQC and all-cause mortality in older adult intertrochanteric fractures at 1 year and the total follow-up time. Further subgroup analysis was performed according to different clinical and biological characteristics to improve the accuracy of the results. RESULTS: The mortality rates were 24.7% and 15.4% at 1 year and the total follow-up time, respectively. Both at one year and the total follow-up time, the mortality of the CRQC-Excellent group was significantly lower than that of the CRQC-Acceptable group (p.adj < 0.05) and the CRQC-Poor group (p.adj < 0.05). After multifactor adjustment, CRQC grades of Acceptable and Poor were independent risk factors affecting the overall and 1-year mortality. In addition, advanced age, ≥ 1 comorbidities, ASA 3 + 4, and prolonged preoperative waiting time were independent risk factors for survival at the total follow-up time. At 1 year, only ASA 3 + 4 and prolonged preoperative waiting time were independent risk factors for survival. Subgroup analysis according to different characteristics at the total follow-up time and at one year showed that in most subgroups, a decrease in the CRQC grade was significantly associated with an increase in all-cause mortality (p for trend < 0.05). CONCLUSIONS: This study highlights that CRQC grades of Acceptable and Poor are associated with increased all-cause mortality in older adult intertrochanteric fractures. We should attempt to achieve good reduction of these fractures.


Asunto(s)
Fracturas de Cadera , Procedimientos de Cirugía Plástica , Femenino , Masculino , Humanos , Anciano , Estudios Retrospectivos , Periodo Posoperatorio , Fracturas de Cadera/cirugía , Pronóstico
19.
J Enzyme Inhib Med Chem ; 37(1): 451-461, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35012401

RESUMEN

Different oleanolic acid (OA) oxime ester derivatives (3a-3t) were designed and synthesised to develop inhibitors against α-glucosidase and α-amylase. All the synthesised OA derivatives were evaluated against α-glucosidase and α-amylase in vitro. Among them, compound 3a showed the highest α-glucosidase inhibition with an IC50 of 0.35 µM, which was ∼1900 times stronger than that of acarbose, meanwhile compound 3f exhibited the highest α-amylase inhibitory with an IC50 of 3.80 µM that was ∼26 times higher than that of acarbose. The inhibition kinetic studies showed that the inhibitory mechanism of compounds 3a and 3f were reversible and mixed types towards α-glucosidase and α-amylase, respectively. Molecular docking studies analysed the interaction between compound and two enzymes, respectively. Furthermore, cytotoxicity evaluation assay demonstrated a high level of safety profile of compounds 3a and 3f against 3T3-L1 and HepG2 cells.HighlightsOleanolic acid oxime ester derivatives (3a-3t) were synthesised and screened against α-glucosidase and α-amylase.Compound 3a showed the highest α-glucosidase inhibitory with IC50 of 0.35 µM.Compound 3f presented the highest α-amylase inhibitory with IC50 of 3.80 µM.Kinetic studies and in silico studies analysed the binding between compounds and α-glucosidase or α-amylase.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Ésteres/farmacología , Ácido Oleanólico/farmacología , Oximas/farmacología , alfa-Amilasas/antagonistas & inhibidores , alfa-Glucosidasas/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Ésteres/síntesis química , Ésteres/química , Humanos , Estructura Molecular , Ácido Oleanólico/síntesis química , Ácido Oleanólico/química , Oximas/síntesis química , Oximas/química , Relación Estructura-Actividad , alfa-Amilasas/metabolismo
20.
BMC Musculoskelet Disord ; 23(1): 671, 2022 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-35836214

RESUMEN

BACKGROUND: Studies have shown that on the coronal plane, whether the direction of the distal locking screw is parallel to the tangent line of the tibiotalar joint can be used to determine whether there is varus or valgus deformity after the treatment of distal tibial fractures with intramedullary nail (IMN) fixation. However, there has been no statistical analysis of the included angle on the coronal plane, and there have been no reports on whether there is a relationship between the direction of the distal locking screw on the sagittal plane or the included angle of the tangent line of the tibiotalar joint and the postoperative alignment of distal tibial fractures treated with IMN fixation. OBJECTIVE: Our aim was to evaluate the relationship between the angles formed by the distal locking screw and the tibiotalar joint tangent (ADTTs) on the sagittal and coronal planes and postoperative alignment in the treatment of distal tibial fractures with IMN fixation. METHODS: We performed a retrospective analysis of 100 patients with distal tibial fractures treated with IMN fixation using the suprapatellar approach. On the coronal and sagittal planes, the ADTTs were arranged from small to large and divided into 4 groups, namely, groups A, B, C and D. One-way ANOVA was used to compare the lateral distal tibial angle (LDTA) and anterior distal tibial angle (ADTA) among all groups, and the chi-square test was used to compare the incidence of postoperative tibial misalignment among all groups. Univariate analysis was performed using chi-square tests to identify factors that might be associated with dislocation, including fibular open reduction and internal fixation (ORIF), limited open reduction, ADTT, IMN diameter, injury mechanism, open vs. closed fracture, comminution, and fibular fracture level. Then, the statistically significant variables in the univariate analysis were included in a multivariate logistic regression equation to evaluate the independent factors related to misalignment. RESULTS: On the coronal plane, the ADTTs of groups A, B, C and D were < 0°, 0°-1.3°, 1.3°-2.7° and > 2.7°, respectively. The mean LDTAs of groups B and C (0°-1.3° and 1.3°-2.7°), group A (< 0°) and group D (> 2.7°) were 89.5 ± 1.6°, 92.0 ± 3.2° and 85.8 ± 3.5°, respectively (P < 0.01). Deformity greater than 5° were more likely in groups A and D than groups B and C [14 of 50 (28%) vs. 1 of 50 (2%), P < 0.001]. On the sagittal plane, the ADTTs of groups A, B, C and D were < 8.9°, 8.9°-10.4°, 10.4°-11.7° and > 11.8°, respectively. The average ADTAs of groups B and C (8.9°-10.4° and 10.4°-11.7°), group A (< 8.9°) and group D (> 11.8°) were 80.4 ± 1.3°, 83.1 ± 3.7° and 77.9 ± 2.5°, respectively (P < 0.01). Deformity greater than 5° was more likely in groups A and D than groups B and C [13 of 50 (26%) vs. 0 of 50 (0%), P < 0.001]. An ADTT of 0°-2.7° on the coronal plane and 8.9°-11.7° on the sagittal plane (OR: 0.08, P = 0.02) and limited open reduction (OR: 0.21, P < 0.01) were independent factors that reduced the likelihood of misalignment. CONCLUSION: The alignment of distal tibial fractures after surgery is sensitive to the ADTT and use of limited open reduction. Controlling the ADTT between 0° and 2.7° on the coronal plane and between 8.9° and 11.7° on the sagittal plane is helpful to reduce the occurrence of misalignment after the treatment of distal tibial fractures by IMN fixation.


Asunto(s)
Fijación Intramedular de Fracturas , Fracturas de la Tibia , Clavos Ortopédicos , Tornillos Óseos , Fijación Intramedular de Fracturas/efectos adversos , Humanos , Reducción Abierta , Estudios Retrospectivos , Fracturas de la Tibia/diagnóstico por imagen , Fracturas de la Tibia/cirugía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA