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1.
Small ; 20(27): e2307759, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38269473

RESUMEN

Two types of functional surfaces with the same roughness but completely different surface topographies are prepared, namely positively skewed surfaces filled with micropillar arrays (Sa ≈4.4 µm, Ssk >0) and negatively skewed surfaces filled with microcavity arrays (Sa ≈4.4 µm, Ssk <0), demonstrating promoting droplet splashing. Remarkably, the critical Weber number for generating satellite droplets on the negatively skewed surfaces is significantly lower than that on the positively skewed surfaces, indicating that the negatively skewed surface with microcavity arrays is more likely to promote droplet splashing. It is mainly attributed to the fact that air on the negatively skewed surface can make the liquid film take on a Cassie-Baxter state on the surface so that the stabilizing capillary force of the liquid film exceeds the destabilizing stress of the air film. Moreover, the surface topography promoting droplet spreading and the mechanical properties of three-phase moving contact lines are analyzed from the perspective of microscopic interface mechanics. Finally, it is demonstrated the designed positively skewed surfaces can be employed for large-area heat dissipation by means of high-efficiency evaporation.

2.
Langmuir ; 40(29): 15263-15270, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39001857

RESUMEN

In this study, we examined how surface topography and particle medium interact to affect the tribological performance of rubber sliding interfaces, uncovering the mechanisms of particle lubrication under various conditions. We found that microtextured surfaces, created using a mold transfer method, modestly reduced the friction coefficient of rubber under both dry and lubricated states, primarily by altering the real contact area. Additionally, the presence of different microconvex textures on the surface topography significantly influenced rubber's tribological properties. Our three-dimensional morphological analysis revealed that microtextured rubber surfaces with higher Sa, Sku, and Sal and lower Str values consistently showed lower friction coefficients during sliding. The friction mechanism was attributed to the combined effects of the material properties, surface topography, and contact area. With the addition of a particle medium, the dry friction coefficient of the rubber interface decreased but exhibited an initial increase, followed by a decrease with increasing particle diameter. When particles were mixed with a water-based cutting fluid, the concentration, diameter, and wettability of the particles significantly impacted the tribological properties due to the synergistic effects of surface topography and particle lubrication. This work enhances our understanding of tribological control for viscoelastic materials through surface design, providing a theoretical basis for the tribological optimization of rubber surfaces.

3.
Chemistry ; 29(16): e202203432, 2023 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-36567623

RESUMEN

The size effect on nanoparticles, which affects the catalysis performance in a significant way, is crucial. The tuning of oxygen vacancies on metal-oxide support can help reduce the size of the particles in active clusters of Pt, thus improving catalysis performance of the supported catalyst. Herein, Ce-Sn solid solutions (CSO) with abundant oxygen vacancies have been synthesized. Activated by simple CO reduction after loading Pt species, the catalytic CO oxidation performance of Pt/CSO was significantly better than that of Pt/CeO2 . The reasons for the elevated activity were further explored regarding ionic Pt single sites being transformed into active Pt clusters after CO reduction. Due to more exposed oxygen vacancies, much smaller Pt clusters were created on CSO (ca. 1.2 nm) than on CeO2 (ca. 1.8 nm). Consequently, more exposed active Pt clusters significantly improved the ability to activate oxygen and directly translated to the higher catalytic oxidation performance of activated Pt/CSO catalysts in vehicle emission control applications.

4.
Langmuir ; 39(27): 9468-9475, 2023 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-37382911

RESUMEN

Polymer-reinforced silica aerogels are thermally insulating materials employed to enhance mechanical properties; however, they exhibit low heat stability and require a complex production process. The main body of this work concerns the synthesis of silicon-containing polyarylacetylene (PSA) resin, which has exceptional thermal properties and is used to strengthen the gel skeleton and significantly improve the heat resistance of the polymer reinforcement phase. The honeycomb-like porous SiO2/PSA aerogels derived from directional freezing were obtained via click reaction, gel aging, freeze-drying, and curing without the requirement for time-consuming solvent replacement. The prepared SiO2/PSA aerogel is low density (∼0.3 g/cm3) and high porosity (∼80%), which provides the material with low levels of thermal conductivity (∼0.06 W/m·K) and excellent thermal insulation performance. When compared to the majority of polymer aerogels and aerogel-like materials, the prepared SiO2/PSA aerogels have high Td5 (∼460 °C) and Yr800 (∼80%) and compressive strength (compression strength > 1.5 MPa). SiO2/PSA composite aerogel has numerous functions in areas where materials must withstand extremely elevated temperatures, such as the aerospace industry.

5.
Langmuir ; 39(28): 9648-9659, 2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37390023

RESUMEN

Regulation over the generation of the Leidenfrost phenomenon in liquids is vitally important in a cutting fluid/tool system, with benefits ranging from optimizing the heat transfer efficiency to improving the machining performance. However, realizing the influence mechanism of liquid boiling at various temperatures still faces enormous challenges. Herein, we report a kind of microgrooved tool surface by laser ablation, which could obviously increase both the static and dynamic Leidenfrost point of cutting fluid by adjusting the surface roughness (Sa). The physical mechanism that delays the Leidenfrost effect is primarily due to the ability of the designed microgroove surface to store and release vapor during droplet boiling so that the heated surface requires higher temperatures to generate sufficient vapor to suspend the droplet. We also find six typical impact regimes of cutting fluid under various contact temperatures; it is worth noting that Sa has a great influence on the transform threshold among six impact regimes, and the likelihood that a droplet will enter the Leidenfrost regime decreases with increasing Sa. In addition, the synergistic effect of Sa and tool temperature on the droplet kinetics of cutting droplets is investigated, and the relationship between the maximum rebound height and the dynamic Leidenfrost point is correlated for the first time. Significantly, cooling experiments on the heated microgrooved surface are performed and demonstrate that it is effective to improve the heat dissipation ability of cutting fluid by delaying the Leidenfrost effect on the microgrooved heated surface.

6.
Langmuir ; 39(33): 11925-11933, 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37566515

RESUMEN

The impact of droplets on particles involves a wide range of complex phenomena and mechanisms, including bubble nucleation, crater formation, fluidization, and more intricate changes in the boiling regime when impacting superheated particles. In this study, we focus on droplet impact behavior on superheated laminar particles at various temperatures and define six typical characteristic patterns of a single droplet impact on superheated laminar particles, including film evaporation, bubbly boiling, immersion boiling, sputter boiling, transition boiling, and film boiling. It is worth noting that the variations of inertial force FI caused by gravity, the capillary force FC generated by the pores of the droplets, and the dewetting force by the vapor phase FV are the main contributors to different evaporation regimes. Interestingly, we find that the Leidenfrost point (LFP) of droplets on the laminar superheated particles decreases with particle size, which is related to the effect of the pore space generated between the laminar particles. Finally, the effect of temperature, particle size, and Weber number (We) on the dynamic behavior of droplet impact is revealed. Experimental results show that the instantaneous diameter of droplets is inversely proportional to the change of height, with different patterns of maximum spreading diameter and maximum bounce height at different particle sizes, while the maximum spreading velocity and maximum bounce velocity are independent of particle size. We believe the present work would provide a broader knowledge and comprehension of the droplet impact on heated particles and promote the development of the safety and productivity of industrial processes such as fluid catalytic cracking, spray drying, and spray cooling.

7.
Environ Sci Technol ; 57(39): 14737-14746, 2023 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-37738479

RESUMEN

Mn-based catalysts preferred in low-temperature selective catalytic reduction (SCR) are susceptible to SO2 poisoning. The stubborn sulfates make insufficient O2 activation and result in deficient reactive oxygen species (ROS) for activating reaction molecules. H2O has long been regarded as an accomplice to SO2, hastening catalyst deactivation. However, such a negative impression of the SCR reaction was reversed by our recent research. Here, we reported a H2O contribution over Mn-based SCR catalysts to counteract SO2 poisoning through accessible O2 activation, in which O2 was synergistically activated with H2O to generate ROS for less deactivation and more expected regeneration. The resulting ROS benefited from the energetically favorable route supported by water-induced Ea reduction and was actively involved in the NH3 activation and NO oxidation process. Besides, ROS maintained high stability over the SO2 + H2O-deactivated γ-MnO2 catalyst throughout the mild thermal treatment, achieving complete regeneration of its own NO disposal ability. This strategy was proven to be universally applicable to other Mn-based catalysts.

8.
Environ Res ; 218: 115059, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36521538

RESUMEN

Globally, landfill sludge (LS) has accumulated in large quantities, and its reduction and dewatering are urgently needed. To address pollution problems and clogging of drainage boards caused by chemical conditioning combined with traditional vacuum preloading (TVP), a freeze-thaw combined with step vacuum preloading (F/T-SVP) method is proposed. A comparative experimental study was carried out between TVP and SVP to explore the anti-clogging mechanism of F/T-SVP in treating LS. As a result, the water discharge for the original sludge (OS) is 1840 ml, the water discharge for TVP is 8830 ml and for SVP is 10,010 ml; The total settlement of SVP is 16% higher than that of TVP; TVP has a volume reduction ratio of 57.6%, while SVP has 66.8%; the OS's water content was 86%, which was reduced to 57.6% by F/T-SVP; The center of the drainage board of TVP is seriously clogged, while the particles of SVP are evenly distributed; The tendency for small particles to undergo transport is relatively low at the beginning of SVP, which can effectively reduce clogging; TVP mainly focuses on the compression of large pores into small pores, and SVP mainly focuses on the compression of large into small pores and micropores. In SVP, there is more consolidation and a more compact structure. When F/T-SVP is used to treat LS, the pores are gradually penetrated, effectively avoiding the generation of clogging and improving LS's drainage and consolidation.


Asunto(s)
Aguas del Alcantarillado , Instalaciones de Eliminación de Residuos , Vacio , Congelación , Agua/química , Eliminación de Residuos Líquidos
9.
Environ Res ; 239(Pt 2): 117356, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37838206

RESUMEN

Freeze-thawing (F/T) is an effective method of sludge dewatering preconditioning and has been studied in many studies. However, previous studies have taken landfill sludge from different regions, filled for different length of time or at different depth, resulting in large differences in initial water content and different treatment effects. Therefore, the effect of initial water content on the dewatering characteristics of F/T preconditioned landfill sludge has been investigated. The sludge with different initial water contents was firstly preconditioned by one F/T cycle. Then the F/T sludge was vacuum filtered and compared with the dewatering performance of FeCl3 preconditioned sludge with the same water content. Finally, the mechanism of the initial water content on the effect of F/T preconditioning was analyzed by the change of sludge internal composition. The results show that the higher the initial water content of the sludge, the greater the improvement of its dewatering performance after F/T preconditioning. The specific resistance and water content after filtration of sludge after F/T conditioning decreased greatly with the increase of the initial water content, reaching their respective minimum values of 13.3 × 1012 m/kg and 58.3% at 85% and 87.5%. These values are lower than the optimal values observed for the sludge conditioned by FeCl3. With the rise in initial water content, the driving force at the ice-water interface gains strength. Small particles aggregate into larger flocs, forming stable drainage channels that enhance the dewatering performance of sludge. Once the initial water content surpasses 85%, the squeezing force exerted by ice crystals amplifies the degree of cracking in sludge particles, releasing bound water and further decreasing the water content of sludge.


Asunto(s)
Aguas del Alcantarillado , Agua , Agua/química , Eliminación de Residuos Líquidos/métodos , Hielo , Filtración , Instalaciones de Eliminación de Residuos
10.
Langmuir ; 38(43): 13166-13176, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36252150

RESUMEN

The wear-resistant superhydrophobic (SHB) surfaces with excellent water-repellency ability were prepared by constructing a microtextured armor on an aluminum surface. With the assistance of laser-induced microtextures, the SHB surface could keep a longer water-repellency ability and a lower friction coefficient even after repeated friction tests under different loads and at different speeds. The mechanism of microtexture-protecting SHB coating is revealed based on both theoretical and elemental analysis. Additionally, we explore the relationship between the three-dimensional topography parameters (ISO 25178) and variation of water contact angles under different test recycles. The results show that the rough surface with appropriate Sa and higher Sku exhibits a better wear resistance, which is mainly related to the storing ability of SHB coating inside the microtextures. Moreover, the surface with appropriate Str exhibits excellent wear resistance, which is mainly associated with better chip-removal ability. Finally, the tribological properties of the microtextured SHB surface are researched. It is worth noting that compared with the microtextured surface without SHB coating and the SHB-coated surface without microtextures, the microtextured SHB surface has the lowest friction coefficient under dry friction because the SHB coating would largely decrease the surface energy of the interface, so the adhesion friction decreases. The microtexture armor on the surfaces would protect the wear of SHB coating, so the SHB coating inside the microtexture could continuously play the role of a particle lubricant at the sliding interface and decrease the friction force of the sliding interface. We believe that the present study would contribute to the further understanding of the constructing mechanism of anti-wear SHB surfaces and provide a new strategy for topography design of engineering surfaces with friction reduction properties.

11.
Environ Res ; 214(Pt 4): 114161, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36029843

RESUMEN

The freeze-thaw vacuum method for conditioning pretreated sludge has been proved that it not only has greater dewatering efficiency but also is more ecologically friendly. In this paper, the experiment is improved to address shortcomings in previous freeze-thaw vacuum approach for sludge treatment. The spatio-temporal distribution relationship of distance-time-temperature is developed and divided into two stages by numerically fitting the temperature change of freezing tubes in the sludge. It is expected to guide the time control of large-scale frozen sludge in practical engineering applications to achieve optimal dewatering treatment. Furthermore, the performance of dehydration after the model test is evaluated on multi-scale: settlement and mechanical properties (macroscopic perspective), mean particle size (mesoscopic perspective), and SEM microstructure (microscopic perspective). The results reveal that the improved sludge treatment method of alternating freeze-thaw vacuum procedures, using both prefabricated horizontal drains (PHDs) and prefabricated vertical drains (PVDs), substantially benefits the sludge dewatering and reduction. This method results in an unparalleled volume reduction of 63.51% and a water content reduction to 58.54%. Moreover, in-situ vane shearing strength of the sludge obtained from the improved test meets the strength requirement for the landfill final cover soil, demonstrating that the method is superior in improving mechanical properties.


Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Deshidratación , Congelación , Humanos , Aguas del Alcantarillado/química , Temperatura , Eliminación de Residuos Líquidos/métodos , Agua/química
12.
Clin Exp Immunol ; 206(2): 216-225, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34453319

RESUMEN

The induction of immune tolerance without the use of immunosuppressive drugs is a crucial problem in organ transplantation. The use of myeloid-derived suppressor cells (MDSCs) as a cell-based adjuvant immunosuppressive therapy is a bright clinical prospect in organ transplantation. MDSCs with stable immunosuppressive activities can be used to treat immune-related diseases. In this study, macrophage colony-stimulating factor (M-CSF) was used to promote myeloid progenitor cell differentiation, and phorbol 12-myristate 13-acetate (PMA) was added to induce MDSCs at the later stage of induction in vitro. Cell phenotypes were detected by flow cytometry and mRNA was detected by real-time-polymerase chain reaction (RT-PCR). A mouse skin transplantation model was used to investigate the cell inhibitory function. The combination of PMA and M-CSF induced the differentiation of myeloid-derived monocytes into MDSCs. MDSCs were found to induce immune tolerance by inhibiting the proliferation and activation of T cells, promoting cytokine secretion and inducing T cell transformation to regulatory T cells (Treg ). PMA significantly up-regulated the expression of Arg-1 and the Arg-1 protein expression in MDSCs and arginase 1 (Arg-1) inhibitor nor-NOHA reversed the MDSC immunosuppressive activity, indicating the involvement of the Arg-1 pathway in MDSC-mediated immunosuppression. M-CSF + PMA-induced MDSCs also significantly prolonged the survival time of skin grafts in mice, showing that MDSCs exert immunosuppressive effects in vivo. We describe a novel scheme to induce immunosuppressive MDSCs in vitro. MDSCs induced by M-CSF with PMA showed stable immunosuppression. MDSCs induced by this protocol may benefit patients with organ transplantation through immune regulation.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Tolerancia Inmunológica/efectos de los fármacos , Monocitos/inmunología , Células Supresoras de Origen Mieloide/inmunología , Acetato de Tetradecanoilforbol/farmacología , Animales , Tolerancia Inmunológica/inmunología , Ratones , Linfocitos T Reguladores/inmunología
13.
Langmuir ; 37(17): 5436-5444, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33899490

RESUMEN

Liquid directional self-transport on the functional surface plays an important role in both industrial and academic fields. Inspired by the natural cactus spine and pitcher plant, we have successfully designed a kind of geometry-gradient slippery surface (GGSS) based on aluminum alloy materials which could actively achieve directional self-movement and also antigravity self-movement of various liquid droplets by topography gradient. The mechanism of liquid directional self-transport was theoretically explored through the mechanical analysis of the triple contact line, which was mainly related to the competition between the driven force induced by Laplace pressure and the adhesive force induced by viscous resistance. The adhesive force between the droplet and the surface was quantitatively measured using a homemade experimental apparatus and the results showed that the lateral adhesive force on the GGSS is much smaller than that on the original surface. Additionally, a series of quantitative experiments were conducted to explore the influence of droplet volume and vertex angle on the transport distance and velocity. Finally, we achieved the antigravity self-transport of the droplet on the inclined GGSS to further verify the self-transport ability of the GGSS. We believe that the proposed GGSS with liquid directional self-transport ability in the present work would provide some potential opportunities in modern tribo-systems to optimize the lubricating qualities, especially the lubrication and friction at the extreme contact interface.

14.
Langmuir ; 37(40): 11737-11749, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-34597055

RESUMEN

Capillary forces of a shearing liquid bridge can significantly affect the friction and adhesion of interacting surfaces, but the underlying mechanisms remain unclear. We custom built a surface force apparatus (SFA, ±2 µN) equipped with in situ optical microscopy and performed normal and lateral force measurements on a reciprocating water bridge formed between two flat plates. A modified wedge method was developed to correct the unique force measurement errors caused by the changing bridge geometry and position. The results found (1) strong linear relations among the bridge shear displacement, the cosine difference between the left and right contact angles, and the lateral adhesion force and (2) the normal adhesion force increased monotonically up to 13% as the bridge geometry approached its axisymmetric state. Quasi-static force analyses based on a newly developed decahedral model showed good agreement with the experiments and improved accuracy compared with that of cylindrical or rectangular column models previously proposed in the literature. Although limited in certain aspects, this study may (1) prove helpful to the design and analysis of liquid bridge force experiments on platforms similar to the SFA used in this study and (2) help to bridge the gap between friction and liquid bridge physics in the literature.

15.
Langmuir ; 37(6): 2140-2145, 2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33523660

RESUMEN

Numerous studies have focused on designing and fabricating functional interfaces that control movement behavior of underwater gas bubbles, which are ubiquitous in a variety of natural and industrial settings. Nevertheless, developing surfaces with in situ tunable bubble movement remain elusive because of current complicated tuning strategies on the specific materials. Inspired by natural pitcher plant and rice leaves, here we report a kind of slippery lubricant-infused anisotropic microgrooved surface (SLI-AMGS) fabricated by femtosecond laser direct writing technology and realize the in situ reversible switching between underwater bubble sliding and pinning by unidirectional mechanical tensile strain. Different experimental parameters including lubricant oil film thickness, bubble volumes and laser power have been researched to manifest the relationship with bubble sliding behaviors. The underlying mechanism of in situ reversible switching mainly lies on the decrease of the lubricant oil film thickness during the process of mechanical stretching in which the uniform and stable oil film layer becomes uneven. This uneven lubricant oil film results in an extraordinary increase of contact angle hysteresis and resistance. At last, we demonstrate a real-time dynamic modulation of the underwater bubble on the SLI-AMGS with a changing mechanical tensile strain for several repeatable times in different acid-based environments. Our work manifests great potential applications in widespread fields including underwater bubble microfluidics and microbubble robots.

16.
BMC Anesthesiol ; 21(1): 146, 2021 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-33980184

RESUMEN

BACKGROUND: Endotracheal intubation and extubation may cause undesirable hemodynamic changes. Intravenous oxycodone has recently been introduced and used for relieving hemodynamic alterations in response to intubation, but there is insufficient information regarding its application in stabilizing hemodynamics during extubation in the patients emerging from general anesthesia. METHODS: One hundred patients, who had undergone assorted laparoscopic surgeries under general anesthesia, were randomly assigned to Control group (saline injection, 50 cases) and Study group (intravenous injection of 0.08 mg/kg oxycodone immediately after completion of the surgical procedure, 50 cases). Blood pressure, heart rate, blood oxygen saturation (SpO2) as well as blood concentrations of epinephrine, norepinephrine, and cortisol were recorded or measured immediately before extubation (T0), during extubation (T1), as well as one minute (T2), 5 min (T3), and 10 min after extubation (T4). In addition, coughing and restlessness, time of eye-opening, and duration from completing surgery to extubation as well as Ramsay Sedation Scale were analyzed. RESULTS: Blood pressure and heart rate as well as blood concentrations of epinephrine, norepinephrine, and cortisol were significantly higher in the Control group compared with the Study group at the time of extubation as well as 1, 5, and 10 min after extubation (P < 0.05). When the patients emerged from general anesthesia, 70 % of the Control group had cough, which was significantly higher than that of Study group (40 %, P < 0.05). Significantly higher number of patients manifested restlessness in the Control group before (40 %) and after extubation (20 %) compared with that in the Study group (20 and 2 %, respectively, P < 0.05). In addition, patients of Control group had lower Ramsay score at extubation (1.7 ± 0.7) as well as 30 min after extubation (2.4 ± 0.9) compared to that of the patients of Study group (2.2 ± 0.9, and 3.0 ± 0.8, respectively, P = 0.003 and 0.001). CONCLUSIONS: Intravenous oxycodone attenuated alterations of hemodynamics and blood hormones associated with extubation during emergence from general anesthesia. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2000040370 (registration date: 11-28-2020) "'retrospectively registered".


Asunto(s)
Extubación Traqueal , Analgésicos Opioides/administración & dosificación , Oxicodona/administración & dosificación , Adulto , Periodo de Recuperación de la Anestesia , Anestesia General , Presión Sanguínea , Tos/etiología , Tos/prevención & control , Método Doble Ciego , Epinefrina/sangre , Femenino , Frecuencia Cardíaca , Humanos , Hidrocortisona/sangre , Inyecciones Intravenosas , Masculino , Norepinefrina/sangre , Estudios Prospectivos
17.
Microb Pathog ; 149: 104317, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32512153

RESUMEN

INTRODUCTION: Staphylococcus aureus is a common human pathogen that causes various diseases including infections on the skin, in the bloodstream and the lower respiratory tracts. The emergence of methicillin-resistant S. aureus (MRSA) made the treatment of the bacterial infection more difficult, calling for development of new therapeutics. Compared with conventional antibiotic therapy, phage therapy offers a promising alternative to combat infections caused by MRSA. RESULTS: Here we showed that phage VB_SauS_SH-St 15644 isolated from sewage inhibited MRSA isolates in vitro and in the murine skin infection model. Phage VB_SauS_SH-St 15644 belongs to Siphoviridae. The genome of the phage is a linear, 45,111 bp double-stranded DNA with GC content of 33.35%. Among the 37 clinical MRSA isolates tested, 12 (32%) were lysed by the phage in vitro. The phage was relatively stable at temperatures up to 40 °C or between pH 6 and 9. However, the phage was sensitive to UV light. 80% of the phage was approximately adsorbed to the host MRSA isolate in 4 min. The one-step growth curve showed that the latent period was about 12 min followed by the growth period (about 9 min). The burst size was estimated at 13 PFU per infected cell. Furthermore, in a murine skin infection model, the phage significantly inhibited MRSA infection. CONCLUSIONS: Our study suggested that phage VB_SauS_SH-St 15644 has a potential to inhibit MRSA skin infection.


Asunto(s)
Bacteriófagos , Staphylococcus aureus Resistente a Meticilina , Siphoviridae , Infecciones Estafilocócicas , Animales , Bacteriófagos/genética , Humanos , Ratones , Infecciones Estafilocócicas/terapia , Staphylococcus aureus
18.
Chemistry ; 26(72): 17567-17573, 2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-32965742

RESUMEN

Lithium-sulfur (Li-S) batteries are one of the most promising high-energy-density storage systems. However, serious capacity attenuation and poor cycling stability induced by the shuttle effect of polysulfide intermediates can impede the practical application of Li-S batteries. Herein we report a novel sulfur cathode by intertwining multi-walled carbon nanotubes (CNTs) and porous boron nitride fibers (BNFs) for the subsequent loading of sulfur. This structural design enables trapping of active sulfur and serves to localize the soluble polysulfide within the cathode region, leading to low active material loss. Compared with CNTs/S, CNTs/BNFs/S cathodes deliver a high initial capacity of 1222 mAh g-1 at 0.1 C. Upon increasing the current density to 4 C, the cell retained a capacity of 482 mAh g-1 after 500 cycles with a capacity decay of only 0.044 % per cycle. The design of CNTs/BNFs/S gives new insight on how to optimize cathodes for Li-S batteries.

19.
Transpl Immunol ; 83: 102006, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38342329

RESUMEN

BACKGROUND: Ischemia/reperfusion injury (IRI) can lead to acute kidney injury and result in high disability and mortality rates. Cystathionine γ-lyase (CSE)-produced hydrogen sulfide (H2S) has been confirmed to play a protective role in renal IRI. While autophagy is involved in renal IRI, its role in the regulation by endoplasmic reticulum stress (ERS) has not been considered. Our study explored the role of CSE/H2S in protecting against renal IRI by regulating ERS-induced autophagy. METHODS: C57/BL6 mice were subjected to 30-min renal ischemia followed by .24-h reperfusion injury (IRI). The H2S donor sodium hydrosulfide hydrate (NaHS) or the CSE inhibitor D,L-propargylglycine (PAG) was injected intraperitoneally (i.p) into the mice. Serum creatinine and urea nitrogen levels were analyzed to evaluate renal function. Renal tubule epithelial cell damage was measured by HE and PAS staining. ERS and microtubule-associated protein light chain 3 (LC3) autophagy (LC3-I to LC3-II conversion) were analyzed by using western blotting. RESULTS: In a C57/BL6 mouse model of acute renal IRI, the application of IRI impaired the renal function, which was accompanied by elevated serum creatinine (P < 0.001) and urea nitrogen levels (P < 0.001). While NaHS pretreatment dramatically attenuated renal IRI, PAG administration exacerbated renal IRI (P < 0.001). Furthermore, NaHS treatment inhibited the ERS-induced increased LC3II/I protein ratio (P < 0.001); increased Beclin-1 protein expression (P < 0.001); PAG pretreatment exacerbated the effects of ERS on both the LC3II/I ratio (P < 0.001) and the Beclin-1 protein expression (P < 0.001). CONCLUSIONS: Our results suggest that the CSE/H2S system is an important therapeutic target for protecting against renal IRI, and it may protect renal tubule epithelial cells from IRI by suppressing ERS-induced autophagy.


Asunto(s)
Lesión Renal Aguda , Daño por Reperfusión , Sulfuros , Ratones , Animales , Beclina-1/farmacología , Creatinina , Daño por Reperfusión/metabolismo , Autofagia , Isquemia/complicaciones , Estrés del Retículo Endoplásmico , Nitrógeno/farmacología , Urea
20.
Nutr Rev ; 2024 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-38219223

RESUMEN

CONTEXT: Despite the important role of inflammation-related factors on the occurrence of chronic diseases, there is still conflicting evidence about the effects of the ketogenic diet (KD) on these factors. OBJECTIVE: In order to obtain a better viewpoint, this study aimed to comprehensively investigate the effects of a KD on inflammation-related markers. DATA SOURCES: To find pertinent randomized controlled trials up to August 2023, databases including PubMed/Medline, Web of Science, Scopus, Cochrane Library, and Embase were searched. DATA EXTRACTION: This study included all randomized controlled trials investigating the effects of a KD on C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, and IL-10 levels. Pooled weighted mean difference (WMD) and 95% confidence intervals (CIs) were achieved by random-effects model analysis for the best estimation of outcomes. DATA ANALYSIS: Forty-four studies were included in this article. The pooled findings showed that a KD has an effect on lowering TNF-α (WMD: -0.32 pg/mL; 95% CI: -0.55, -0.09; P = 0.007) and IL-6 (WMD: -0.27 pg/mL; 95% CI: -0.52, -0.02; P = 0.036) compared with control groups. However, no significant effect was reported for others inflammation marker-related levels. The results of the subgroup analysis showed that, in trials following the KD for ≤8 weeks and in people aged ≤50 years, the reduction in TNF-α levels was significantly higher than in other groups. In addition, in people with a body mass index greater than 30 kg/m2 compared to a body mass index ≤30 kg/m2, IL-6 levels decreased to a greater extent after receiving the KD. CONCLUSIONS: Consequently, adherence to a KD appears to improve some markers associated with inflammation, including TNF-α and IL-6.

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