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Tillage intensity significantly influences the heterogeneous distribution and dynamic changes of soil microorganisms, consequently shaping spatio-temporal patterns of SOC decomposition. However, little is known about the microbial mechanisms by which tillage intensity regulates the priming effect (PE) dynamics in heterogeneous spatial environments such as aggregates. Herein, a microcosm experiment was established by adding 13C-labeled straw residue to three distinct aggregate-size classes (i.e., mega-, macro-, and micro-aggregates) from two long-term contrasting tillage histories (no-till [NT] and conventional plow tillage [CT]) for 160 days to observe the spatio-temporal variations in PE. Metagenomic sequencing and Fourier transform mid-infrared techniques were used to assess the relative importance of C-degrading functional genes, microbial community succession, and SOC chemical composition in the aggregate-associated PE dynamics during straw decomposition. Spatially, straw addition induced a positive PE for all aggregates, with stronger PE occurring in larger aggregates, especially in CT soil compared to NT soil. Larger aggregates have more unique microbial communities enriched in genes for simple C degradation (e.g., E5.1.3.6, E2.4.1.7, pmm-pgm, and KduD in Nitrosospeera and Burkholderia), contributing to the higher short-term PE; however, CT soils harbored more genes for complex C degradation (e.g., TSTA3, fcl, pmm-pgm, and K06871 in Gammaproteobacteria and Phycicoccus), supporting a stronger long-term PE. Temporally, soil aggregates played a significant role in the early-stage PEs (i.e., < 59 days after residue addition) through co-metabolism and nitrogen (N) mining, as evidenced by the increased microbial biomass C and dissolved organic C (DOC) and reduced inorganic N with increasing aggregate-size class. At a later stage, however, the legacy effect of tillage histories controlled the PEs via microbial stoichiometry decomposition, as suggested by the higher DOC-to-inorganic N and DOC-to-available P stoichiometries in CT than NT. Our study underscores the importance of incorporating both spatial and temporal microbial dynamics for a comprehensive understanding of the mechanisms underlying SOC priming, especially in the context of long-term contrasting tillage practices.
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Carbono , Microbiota , Solo/química , Microbiologia do Solo , Biomassa , Agricultura/métodosRESUMO
OBJECTIVE: To explore the risk factors for poor prognosis in sepsis-associated acute kidney injury (SA-AKI) and establish a nomogram predictive model. METHODS: The clinical data of patients with SA-AKI admitted to the department of critical care medicine of Shandong Provincial Hospital Affiliated to Shandong First Medical University from January 2019 to September 2022 were retrospectively analyzed, including demographic information, worst values of blood cell counts and biochemical indicators within 24 hours of SA-AKI diagnosis, whether the patient received renal replacement therapy (RRT), mechanical ventilation, vasopressor therapy during hospitalization, acute physiology and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), fibrinogen-to-albumin ratio (FAR) within 24 hours of diagnosis, acute kidney injury (AKI) staging, total length of hospital stay, length of intensive care unit (ICU) stay, and others. According to the 28-day outcome, the patients were divided into survival group and death group, and the indicators between the two groups were compared. Univariate and multivariate Logistic regression analyses were used to screen for risk factors associated with mortality in SA-AKI patients. A nomogram predictive model for SA-AKI prognosis was constructed based on the identified risk factors. Receiver operator characteristic curve (ROC curve) and calibration plots were generated to evaluate the predictive value of the nomogram model for SA-AKI prognosis. RESULTS: A total of 113 SA-AKI patients were included, with 67 in the survival group and 46 in the death group. The 28-day mortality among SA-AKI patients was 40.7%. The comparison between the two groups showed that there were statistically significant differences in age ≥ 65 years, AKI stage, mechanical ventilation, vasopressors, RRT, length of ICU stay, and laboratory indicators cystatin C (Cys C), fibrinogen (Fib), and FAR. Multivariate Logistic regression analysis showed that age ≥ 65 years [odds ratio (OR) = 7.967, 95% confidence interval (95%CI) was 1.803-35.203, P = 0.006], cystatin C (OR = 7.202, 95%CI was 1.756-29.534, P = 0.006), FAR (OR = 2.444, 95%CI was 1.506-3.968, P < 0.001), and RRT (OR = 7.639, 95%CI was 1.391-41.951, P = 0.019) were independent risk factors for mortality in SA-AKI patients. ROC curve analysis showed that the area under the ROC curve (AUC) for age ≥ 65 years, cystatin C, FAR, and RRT in predicting SA-AKI patient mortality were 0.713, 0.856, 0.911, and 0.701, respectively. A nomogram predictive model for SA-AKI patient prognosis was constructed based on age ≥ 65 years, cystatin C, FAR, and RRT, with an AUC of 0.967 (95%CI was 0.932-1.000) according to ROC curve analysis. The calibration plot indicated good consistency between predicted and actual probabilities. CONCLUSIONS: Age ≥ 65 years, cystatin C, FAR, and RRT are independent risk factors for mortality in SA-AKI patients. The nomogram predictive model based on these four factors can accurately predict SA-AKI patient prognosis, helping physicians adjust treatment strategies in a timely manner and improve patient outcomes.
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Injúria Renal Aguda , Sepse , Humanos , Idoso , Cistatina C , Estudos Retrospectivos , Unidades de Terapia Intensiva , Sepse/complicações , Sepse/diagnóstico , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Prognóstico , Curva ROC , FibrinogênioRESUMO
Porous CNT sponge (CNTS) and aligned CNT array (CNTA) were used as light absorbers to generate water vapor by harvesting solar energy. To improve the wettability of water on superhydrophobic CNTs and enhance water transport in porous CNT materials, CNTs were decorated with a hydrophilic silk fibroin (SF) protein coating. Water rapidly infiltrates the porous SF-modified CNT materials. Importantly, strong water-SF interactions via the hydrogen bonding between SF protein molecules and CNT sidewalls resulted in a reduction in the vaporization enthalpy of water in the SF-modified CNT materials, which facilitated vapor generation. Additionally, the SF-modified CNT light absorbers exhibit excellent vapor generation performance over a wide pH range of 2 to 12 and good stability. The SF-modified CNT materials thus have the advantage of being potentially applicable to the purification of wastewater and desalination of brackish water with high or low pH values. SF-CNTA light absorbers with vertically aligned CNTs, which are of great benefit in water transport and vapor escape, achieved a water evaporation rate of 3.2 kg m-2 h-1 under one sun irradiation with an energy transfer efficiency of 94%. After a desalination treatment, the concentrations of primary ions in seawater are greatly decreased and meet the requirements for drinking water.
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Owing to deep activation in biotissues and enhanced targeting efficiency, developing photoresponsive polymer-upconversion nanoparticles (PP-UCNPs) nanovectors has witnessed rapid growth in the past decade. However, up to date, all developed nanovectors require high-order photon processes to initiate the release of cargos. The photodamage caused by high-power near-infrared laser light may be a critical obstacle to their clinical application. Here, for the first time, by leveraging absorption-emission spectral matching between donor-acceptor Stenhouse adducts (DASA) PP and UCNPs (λex , 808 nm) in the green region (≈530 nm), the designed nanovector is capable of releasing cargos at a low-power 808 nm excitation (0.2 W). Considering the high molar absorptivity, biobenign, and synthetic tunability of DASA, DASA PP can be utilized as an up-and-coming candidate to design and synthesize the next generation of upconversion nanovectors without photodamage.
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Nanopartículas , Polímeros , Raios InfravermelhosRESUMO
We investigated the selective adsorption and desorption behaviors of charged molecules (calcein, brilliant green, and methylene blue) dissolved in water using polydopamine-modified carbon nanotube (CNT) sponges. Porous CNT sponges (CNTSs) as a scaffold for the selective adsorption and desorption of aqueous molecules were fabricated by using a chemical vapor deposition technique. To improve the hydrophilicity of porous CNTS and to control the adsorption and desorption of aqueous molecules, CNT sidewalls were decorated with a hydrophilic polydopamine layer through noncovalent interactions between CNT sidewalls and polydopamine. After this noncovalent chemical modification, the water contact angle of CNTS was close to 0, and the aqueous solution can rapidly infiltrate the three-dimensional (3D) networks of polydopamine-modified CNTS (Pdop-CNTS). The incorporation of pH-responsive polydopamine in CNTS showed an evident advantage of adsorbing positively charged molecules over a pH range of 10.5-4. In aqueous solutions with pH value of ≤3, Pdop-CNTS selectively adsorbed negatively charged molecules. Aqueous molecules carrying net charges were successfully separated from mixture solutions. Moreover, charged calcein and methylene blue molecules adsorbed on the 3D networks of Pdop-CNTS were selectively desorbed from Pdop-CNTS by tuning the pH value of the desorption solution.
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Activating upconversion nanoparticle-based photoresponsive nanovectors (UCPNVs) by upconversion visible light at low-power near-infrared (NIR) excitation can realize deeper biotissue stimulation with a minimized overheating effect and photodamage. Here, we demonstrate a facile strategy to construct new surface-decorated UCPNVs based on Passerini three-component reaction (P-3CR) in highly convenient and effective manners. Such UCPNVs materials have a tailored deprotecting wavelength that overlaps upconversion blue light. By using 3-perylenecarboxaldehyde, Tm3+/Yb3+ ion-doped UCNP-containing isocyanides, and antitumor agent chlorambucil as the three components, the resulting monodisperse UCPNV exhibits an efficient release of caged chlorambucil under a very low 976 nm power. This approach expands the synthetic toolbox to enable quick development of UCPNVs for UCNP-assisted low-power NIR photochemistry.
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We investigated the effect of an electric treatment on the wettability of aqueous solution on carbon nanotubes (CNT) and ion transport behaviors in superhydrophobic porous carbon nanotube sponges (CNTS). This electric activation treatment where an electric voltage was applied across highly porous CNT sponge induced an electrowetting effect. This effect significantly reduced interfacial tensions between CNT sidewalls and aqueous liquids. Meanwhile, polar functional groups were also introduced on CNTs. Both electrowetting effect and polar functional groups greatly improved the wettability of aqueous solutions on CNT sidewalls. After the electric treatment, we observed a dramatic increase in the overall rate of ion flow across porous CNT sponges. The formation of solution channels during the electric treatment is responsible for the enhanced ionic transport in porous CNT sponges. The overall rate of ion flow increased with the increases in electric treatment time and voltage. The crucial role of electric treatment parameters in the ion transport provides a new strategy for precisely controlling the ion transport across CNT sponges by tuning electric treatment time or voltage. Importantly, the good wettability of aqueous solution on CNT sidewalls greatly increased the effective surface area of CNT sponges and thus significantly improved the performance of CNTS-based supercapacitors after the electric treatment.
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The glass transition behaviors of thin polymer films on the sidewalls of carbon nanotubes (CNTs) in CNT sponges (CNTSs) were studied. Due to the extremely large surface area of CNTS, the glass transition temperatures (Tg) of thin polystyrene (PS) and poly(methyl methacrylate) (PMMA) films were measured using a routine experimental method, differential scanning calorimetry (DSC). We thus provide a direct Tg comparison between the thin film and the bulk sample using the same DSC technique. For thin polymer films on the CNT sidewalls, free surface and polymer-substrate interfacial interactions co-exist. It is well-known that polymer chains at the liquid-like free surface tend to have a relatively high mobility, but the mobility in the interfacial layer near the substrate depends strongly on the polymer-substrate interaction strength. Accordingly, we tuned the polymer-substrate interaction strength by introducing an amphiphilic sodiumdodecylsulfate (SDS) molecule layer on the CNT sidewalls. The value and sign of Tg deviation were influenced by the competition between the free surface effect and the interfacial interactions. Strong polymer-substrate interactions led to a decrease in the mobility of polymer chains near the substrate and weak polymer-substrate interactions have little influence on the mobility of polymer chains near the substrate. When the polymer-substrate interactions are strong, both the free surface effect and the polymer-substrate interaction are key factors influencing the glass transition temperature. For thin polymer films having weak interactions with substrates, the free surface effect dominates the glass transition behavior and Tgs shows a large reduction. We also observed a double Tg behavior in the thin PS film and found the thickness of the PS film on the substrate was a deciding factor for controlling the spatial variation of Tg.
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We investigate the effect of carbon nanotubes (CNTs) on the crystalline microstructure and ferroelectric behavior of polyvinylidene fluoride- co-trifluoroethylene (P(VDF-TrFE)). X-ray analysis suggests that CNT can act as a template and direct the chain orientation of P(VDF-TrFE) crystals. In the presence of CNTs, the molecular chain axis ( c axis) of the ß-phase crystal is oriented parallel to the long axis of CNTs. Moreover, we find that this templating effect did not cause a polymorph transition. For P(VDF-TrFE)/CNT composites, the crystallinity of P(VDF-TrFE) is slightly decreased. The orientation of the c axis induced by the templating effect of CNTs has a significant impact on the ferroelectric behavior of P(VDF-TrFE). As compared to a pure P(VDF-TrFE) film, the remnant polarization of the P(VDF-TrFE)/CNT composite is enhanced. Correspondingly, the piezoelectric property of the P(VDF-TrFE)/CNT composite shows a significant enhancement.
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We investigate the effect of the presence of vertically aligned multiwalled carbon nanotubes (CNTs) on the orientation of poly(ethylene oxide) (PEO) lamellae and PEO crystallinity. The high alignment of carbon nanotubes acting as templates probably governs the orientation of PEO lamellae. This templating effect might result in the lamella planes of PEO crystals oriented along a direction parallel to the long axis of the nanotubes. The presence of aligned carbon nanotubes also gives rise to the decreases in PEO crystallinity, crystallization temperature, and melting temperature due to the perturbation of carbon nanotubes to the crystallization of PEO. These effects have significant implications for controlling the orientation of PEO lamellae and decreasing the crystallinity of PEO and thickness of PEO lamellae, which have significant impacts on ion transport in PEO/CNT composite and the capacitive performance of PEO/CNT composite. Both the decreased PEO crystallinity and the orientation of PEO lamellae along the long axes of vertically aligned CNTs give rise to the decrease in the charge transfer resistance, which is associated with the improvements in the ion transport and capacitive performance of PEO/CNT composite.
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This report describes a technique for fabricating dual-structured hierarchical surface topography on the surface of polydimethylsiloxane (PDMS) films through simply replicating prefabricated patterns and wrinkling PDMS films. To enhance the biocompatibility of PDMS films, we synthesize a biocompatible dopamine-glycopolymer, which is utilized to modify the chemical feature of the PDMS surface. Dopamine component in this copolymer is introduced for the formation of a carbohydrate layer on the surface of PDMS films because of its excellent adhesion. The carbohydrate component in this copolymer enhances the interactions between cells and PDMS films. We investigate the influence of the chemical and topographical surface properties of the extracellular matrix on fibroblast cell growth. The coupling of the dopamine-glycopolymer coating and hierarchical topography produces the best induction effect on the alignment of cells.
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Proliferação de Células , Dimetilpolisiloxanos , Matriz Extracelular , Fibroblastos , Polímeros , Propriedades de SuperfícieRESUMO
Terahertz time-domain spectroscopy is an effective technique that applies spectral measurements by using an ultra fast femtosecond laser. These unique properties of terahertz waves make it an effective nondestructive testing technology. Currently, it has been applied in many fields. However, when we calculate the optical parameters of the sample especially for liquids, from data obtained with time-domain spectroscopy, a common problem occurred is spurious oscillation, which is caused by the Fabry-Perot effect in sample, containers and optical elements. In order to obtain high frequency resolution and accurate sample optical parameters, it is necessary to use some signal processing techniques properly. In this paper, we improved de-convolution algorithm and presented a simple algorithm based on the traditional optical parameter calculation model. Considering the nonlinear absorption of THz wave by samples, containers, emitters or detectors, a THz time-domain trace containing echo signals can be represented as a convolution of the primary peak, some delta functions and nonlinear transfer functions. By analyzing equationsï¼spurious oscillations in the THz spectra result from echo signals can be removed or reduced effectively. The use of the method is discussed and the transmission spectrum of soybean oil in 0.2~2.0 THz range is measured accurately by terahertz time-domain spectroscopy. Experiments show that, this method can effectively remove the frequency oscillation caused by echoes. This algorithm is not affected by the tested object, and is equally applicable to other liquid measurements in THz range. What's more, compared with the traditional method of main pulse interception, this algorithm under the same experimental conditions can effectively improve frequency resolution of soybean oil in 0.2~2.0 THz region, from 50 GHz to less than 10 GHz. At the end of this paper, the causation of remaining oscillation in sample spectrum and absorption spectrum were deeply analyzed.