Methylomonadaceae was the active and dominant methanotroph in Tibet lake sediments.

Methane (CH4), an important greenhouse gas, significantly impacts the local and global climate. Our study focused on the composition and activity of methanotrophs residing in the lakes on the Tibetan Plateau, a hotspot for climate change research. Based on the field survey, the family Methylomonadaceae had a much higher relative abundance in freshwater lakes than in brackish and saline lakes, accounting for ~92% of total aerobic methanotrophs. Using the microcosm sediment incubation with 13CH4 followed by high throughput sequencing and metagenomic analysis, we further demonstrated that the family Methylomonadaceae was actively oxidizing CH4. Moreover, various methylotrophs, such as the genera Methylotenera and Methylophilus, were detected in the 13C-labeled DNAs, which suggested their participation in CH4-carbon sequential assimilation. The presence of CH4 metabolism, such as the tetrahydromethanopterin and the ribulose monophosphate pathways, was identified in the metagenome-assembled genomes of the family Methylomonadaceae. Furthermore, they had the potential to adapt to oxygen-deficient conditions and utilize multiple electron acceptors, such as metal oxides (Fe3+), nitrate, and nitrite, for survival in the Tibet lakes. Our findings highlighted the predominance of Methylomonadaceae and the associated microbes as active CH4 consumers, potentially regulating the CH4 emissions in the Tibet freshwater lakes. These insights contributed to understanding the plateau carbon cycle and emphasized the significance of methanotrophs in mitigating climate change.

Fluorinated Graphene-Lewis-Base Polymer Composites as a Multifunctional Passivation Layer for High-Performance Perovskite Solar Cells.

Increasing the open-circuit voltage (Voc) stands as a critical strategy for further improving the efficiency of organic-inorganic halide perovskite solar cells (PSCs). Lewis basic polymers, such as polymethyl methacrylate (PMMA), are considered as an effective approach to reduce the nonradiative recombination at the perovskite surface and protect the photoactive layer against moisture. However, the insulating nature of PMMA inherently leads to increased series resistance in PSCs. Here, we propose a multifunctional passivation layer (FG-PMMA) composed of fluorinated graphene (FG) and PMMA, offering high conductivity, a good passivation effect, and excellent hole transportation capabilities. The introduction of FG not only reduces the resistance of the PMMA layer but also improves its hydrophobicity. More importantly, we found that fluoride, which acts as a p-type dopant in graphene, can further reduce the nonradiative recombination centers by forming PbF2 with uncoordinated Pb0 at the perovskite/hole transport layer interface. As a result, the introduction of FG-PMMA significantly enhances the photovoltaic performance, with a record-high open-circuit voltage (Voc) of 1.247 V and an average power conversion efficiency of 22.91%, higher than those of PMMA-based devices (20.75%, 1.210 V), as well as increasing the device's moisture stability, with over 90% of the initial efficiency maintained after 1200 h of aging at room temperature and a relative humidity of 35%.

In vitro and in vivo assessment of structural integrity for HPCD complex@Liposome nanocomposites from ocular surface to the posterior segment of the eye.

Investigating the structural integrity of carriers in transit from ocular surface to ocular posterior segment is essential for an efficient topical drug delivery system. In this study, dual-carrier hydroxypropyl-ß-cyclodextrin complex@Liposome (HPCD@Lip) nanocomposites were developed for the efficient delivery of dexamethasone. Förster Resonance Energy Transfer with near-infrared I fluorescent dyes and in vivo imaging system were used to investigate the structural integrity of HPCD@Lip nanocomposites after crossing Human conjunctival epithelial cells (HConEpiC) monolayer and in ocular tissues. The structural integrity of inner HPCD complexes was monitored for the first time. The results suggested that 23.1 ± 6.4 % of nanocomposites and 41.2 ± 4.3 % of HPCD complexes could cross HConEpiC monolayer with an intact structure at 1 h. 15.3 ± 8.4 % of intact nanocomposites could reach at least sclera and 22.9 ± 1.2 % of intact HPCD complexes could reach choroid-retina after 60 min in vivo, which showed that the dual-carrier drug delivery system could successfully deliver intact cyclodextrin complexes to ocular posterior segment. In conclusion, in vivo assessment of structural integrity of nanocarriers is greatly significant for guiding the rational design, higher drug delivery efficiency and clinical transformation for topical drug delivery system to the posterior segment of the eye.

Cu2O/Co3O4 nanoarrays for rapid quantitative analysis of hydrogen sulfide in blood.

2D heterostructure nanoarrays have emerged as a promising sensing material for rapid disease detection applications. In this study, a bio-H2S sensor based on Cu2O/Co3O4 nanoarrays was proposed, the controllable preparation of the nanoarrays being achieved by exploring the experimental parameters of the 2D electrodeposition in situ assembly process. The nanoarrays were designed as a multi-barrier system with strict periodicity and long-range order. Based on the interfacial conductance modulation and vulcanization reaction of Cu2O and Co3O4, the sensor exhibited superior sensitivity, selectivity, and stability to H2S in human blood. In addition, the sensor exhibited a reasonable response to 0.1 µmol L-1 Na2S solution, indicating that it had a low detection limit for practical applications. Moreover, first-principles calculations were performed to study changes in the heterointerface during the sensing process and the mechanism of rapid response of the sensor. This work demonstrated the reliability of Cu2O/Co3O4 nanoarrays applied in portable sensors for the rapid detection of bio-H2S.

Additive Manufacturing of Dense Ti6Al4V Layer via Picosecond Pulse Laser.

Ultrashort pulse laser shows good potential for heat control improvement in metal additive manufacturing. The challenge of applying ultrashort pulse laser as the heat source is to form a fully melted and dense microstructure. In this study, a picosecond pulse laser is introduced for fabricating single layer Ti6Al4V samples. The results, by examining through X-ray computed tomography (X-CT), scanning electron microscopy (SEM), show that highly dense Ti6Al4V samples were fabricated with optimized process parameters. The analysis of the cross section presents a three-zones structure from top to bottom in the sequence of the fully melted zone, the partially melted zone, and the heat-affected zone. A semi-quantitative study is performed to estimate the thermal efficiency of melted pool formation. The mechanical properties of the samples are tested using nano-indentation, showing an elastic modulus of 89.74 ± 0.74 GPa. The evidence of dense melted pool with good mechanical properties indicates that the picosecond laser can be integrated as the heat source with the current metal additive manufacturing to fabricate parts with accuracy control for the smaller size of thermal filed.

Can Kinesio taping improve discomfort after mandibular third molar surgery? A systematic review and meta-analysis.

OBJECTIVE: The purpose of this study was to evaluate whether Kinesio taping (KT) can improve patient discomfort after mandibular third molar surgery. MATERIALS AND METHODS: This systematic review and meta-analysis was conducted according to the PICO strategy. We searched 4 databases for related articles. All controlled trials or randomized controlled trials that evaluated the application of KT after mandibular third molar surgery were included. Screening and article selection were carried out by two independent reviewers. The main evaluation indicators were facial swelling, pain, and trismus. All statistical analyses were conducted using Review Manager 5.3 software. RESULT: This analysis included 8 articles. The combined results showed that compared with the control group, the postoperative application of KT significantly reduced pain in the early (early stage mean difference (MD), - 2.00; 95% confidence interval (CI), - 2.40 to - 1.60; P < 0.00001) and late (late stage MD, - 1.18; 95% CI, - 2.26 to - 0.11; P = 0.03) postoperative periods and, thus, reduced the intake of painkillers. KT also reduced facial swelling in the early and late postoperative periods (early stage standardized mean difference (SMD), - 1.34; 95% CI, - 1.99 to - 0.68; P < 0.0001; late stage SMD, - 0.31; 95% CI, - 0.51 to - 0.11; P = 0.002). In addition, the postoperative application of KT improved restricted mouth opening in the early and late postoperative periods (early stage MD, - 5.03 mm; 95% CI, - 6.32 to - 3.74 mm; P < 0.00001; late stage MD, - 3.42 mm; 95% CI, - 5.31 to - 1.52 mm; P = 0.0004). CONCLUSION: KT can significantly reduce postoperative pain, swelling, and trismus after impacted mandibular tooth extraction. Additional high-quality and rigorously designed randomized controlled trials should be conducted to verify these conclusions. CLINICAL RELEVANCE: KT is a low-cost, simple, effective nondrug therapy for the postoperative management of mandibular third molar extraction and has broad prospects for clinical application.

Rapid screening and purification of potential alkaloid neuraminidase inhibitors from Toddalia asiatica (Linn.) Lam. roots via ultrafiltration liquid chromatography combined with stepwise flow rate counter-current chromatography.

Toddalia asiatica (Linn.) Lam. is a medical plant traditionally used to treat coughs, fevers, and various diseases. Alkaloids are the main active ingredients in Toddalia asiatica (Linn.) Lam., but traditional methods for screening and separation are complex and labor-intensive. In this work, an efficient strategy was developed to rapidly screen, identify, and separate neuraminidase inhibitors from Toddalia asiatica (Linn.) Lam. Ultrafiltration, high performance liquid chromatography, and time-of-flight mass spectrometry were employed for rapid screening and identification of neuraminidase inhibitors. A two-phase solvent system comprising n-hexane/ethyl acetate/methanol/water (5:5:3:7, v/v) was then selected for separation by high-speed counter-current chromatography. A sample loading of 200 mg and a stepwise flow rate were achieved by increasing the flow rate from 2 to 4 mL/min after 4 h. Three main fluoroquinoline alkaloids (haplopine, skimmianine, and 5-methoxydictamnine) along with two coumarins were obtained via one-step separation and their structures were determined by mass spectrometry and nuclear magnetic resonance. In vitro assays revealed skimmianine with half-maximal inhibitory concentration of 16.2 ± 0.7 µmol/L was selected as the potential highest neuraminidase inhibitor. The results suggest that ultrafiltration high performance liquid chromatography-mass spectrometry combined with high-speed counter-current chromatography is efficient for the screening and isolation of neuraminidase inhibitors from complex natural products.

Au@Cu Nanoarrays with Uniform Long-Range Ordered Structure: Synthesis and SERS Applications.

The nanostructures with uniform long-range ordered structure are of crucial importance for performance standardization of high-quality surface-enhanced Raman scattering (SERS) spectra. In this paper, we described the fabrication and SERS properties of Au decorated Cu (Au@Cu) nanoarrays. The Cu nanoarrays with uniform long-range ordered structure were first synthesized by in-situ electrochemistry assembly on insulated substrate. The Cu nanoarrays can reach a size of centimeters with strictly periodic nano-microstructure, which is beneficial for the production and performance standardization of SERS substrates. Then Au nanoparticals were decorated on the Cu nanoarrays by galvanic reaction without any capping agent. The obtained Au@Cu nanoarrays exhibit excellent SERS activity for 4-Mercaptopyridine, and the sensitivity limit is as low as 10-8 M. Therefore, this facile route provides a useful platform for the fabrication of SERS substrates based on nano ordered arrays.

Ultrasonic soldering of Cu alloy using Ni-foam/Sn composite interlayer.

In this study, Cu alloy joints were fabricated with a Ni-foam reinforced Sn-based composite solder with the assistance of ultrasonic vibration. Effects of ultrasonic soldering time on the microstructure and mechanical properties of Cu/Ni-Sn/Cu joints were investigated. Results showed that exceptional metallurgic bonding could be acquired with the assistance of ultrasonic vibration using a self-developed Ni-foam/Sn composite solder. For joint soldered for 5 s, a (Cu,Ni)6Sn5 intermetallic compound (IMC) layer was formed on the Cu substrate surface, Ni skeletons distributed randomly in the soldering seam and a serrated (Ni,Cu)3Sn4 IMC layer was formed on the Ni skeleton surface. Increasing the soldering time to 20 s, the (Ni,Cu)3Sn4 IMC layer grew significantly and exhibited a loose porous structure on the Ni skeleton surface. Further increase the soldering time to 30 s, Ni skeletons were largely dissolved in the Sn base solder, and micro-sized (Ni,Cu)3Sn4 particles were formed and dispersed homogeneously in the soldering seam. The formation of (Ni,Cu)3Sn4 particles was mainly ascribed to acoustic cavitations induced erosion and grain refining effects. The joint soldered for 30 s exhibited the highest shear strength of 64.9 ±â€¯3.3 MPa, and the shearing failure mainly occurred at the soldering seam/Cu substrate interface.

Facile Synthesis of Platelike Hierarchical Li1.2Mn0.54Ni0.13Co0.13O2 with Exposed {010} Planes for High-Rate and Long Cycling-Stable Lithium Ion Batteries.

Lithium-rich layered oxides are promising cathode candidates for the production of high-energy and high-power electronic devices with high specific capacity and high discharge voltage. However, unstable cycling performance, especially at high charge-recharge rate, is the most challenge issue which needs to be solved to foster the diffusion of these materials. In this paper, hierarchical platelike Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials were synthesized by a facile solvothermal method followed by calcination. Calcination time was found to be a key parameter to obtain pure layered oxide phase and tailor its hierarchical morphology. The Li-rich material consists of primary nanoparticles with exposed {010} planes assembled to form platelike layers which exhibit low resistance to Li+ diffusion. In detail, the product by calcination at 900 °C for 12 h exhibits specific capacity of 228, 218, and 204 mA h g-1 at 200, 400, and 1000 mA g-1, respectively, whereas after 100 cycles at 1000 mA g-1 rate of charge and recharge the specific capacity was retained by about 91%.

Expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths.

BACKGROUND: It has been studied that the distribution of bone morphogenetic protein 2 is regular under bone defect situation. OBJECTIVE: To observe the expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths. METHODS: Forty-eight New Zealand rabbits were divided into two groups randomly. 0.5 cm bone defect and 3.0 cm bone defect were made by wire saw at the middle part of radius bone after anaesthesia. RESULTS AND CONCLUSIONS: Western blot results showed that in the 0.5 cm bone defect group, the expression of bone morphogenetic protein 2 of the tissues in the bone defect site was increased gradually at 1, 3, 4 weeks after operation, and the expression in each defect group was increased when compared with that immediately after injury (P<0.05). In the 3.0 cm bone defect group, the expression of bone morphogenetic protein 2 of tissues in bone defect site was increased gradually and reached to its peak at 3 weeks after the operation (P<0.05). The peak value in the 3.0 cm bone defect group was significantly higher than that in 0.5 cm bone defect group (P<0.05). The peak value was maintained in high level. The comparison of bone callus formation showed that the bone callus formation of 3.0 cm bone defect group was less than that of the 0.5 cm bone defect group at 3 and 4 weeks after operation (P<0.05). The results indicate that expression of the bone morphogenetic protein 2 in 3.0 cm bone defect site is increased significantly, but the expression level cannot make the bone defect heal itself.

Gene gun transferring-bone morphogenetic protein 2 (BMP-2) gene enhanced bone fracture healing in rabbits.

PURPOSE: Transferring the bone morphogenetic protein 2 (BMP-2) genes into the tissues or cells can improve the bone healing of the fracture has been widely accepted. We evaluated the efficiency of using gene gun to transfer the BMP-2 gene thereby affected the healing of a fractured bone. METHODS: The vector coding for BMP-2 was constructed by a non-replicating encephalo-myocarditis virus (ECMV)-based vector. The segmental bone defect (1.5 cm) model was created by a wire-saw at the middle part of the radius bone of the New Zealand white rabbits. Then either BMP-2 gene or control vector without BMP-2 gene was injected into the tissues around the fracture site. Healing of the defects was monitored radiographically for 9 weeks, bone consolidation was determined by the Lane-Sandhu score pre- and post-operatively, which can evaluated bone formation, bone connect and bone plasticity. RESULTS: The radiographic score and bone consolidation rates were significantly higher in animals injected with BMP-2 gene group as compared with control vector-injected animals (P<0.05). The control group still showed no radiological signs of stable healing. Western-blot and RT-PCR showed BMP-2 expression was significant increase in the tissues around the site of osseous lesions in comparison with the control vector-injected animals (P<0.05). CONCLUSIONS: Our results suggested that BMP-2 gene transferred by gene gun could increase the expression of BMP-2 protein and improved the bone callus formation therefore shortened the time of bone defect healing.

The potential role of heat shock proteins in acute spinal cord injury.

PURPOSE: This study aims to investigate the differential expression proteins profile of spinal cord tissues after acute spinal cord injury (ASCI), provide preliminary results for further study and explore the secondary injury mechanisms underlying ASCI. METHODS: Using Allen's frame to establish ASCI model of Sprague-Dawley rats, then a stable isotope-labelled strategy using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional (2D) liquid chromatography tandem mass spectrometry (2D LC-MS/MS) was performed to separate and identify differentially expressed proteins. RESULTS: A total of 220 differentially expressed proteins were identified in the spinal cord tissues of H-8 group (acute spinal cord injury after 8 h) compared with H-0 group (acute spinal cord injury after 0 h); Up to 116 proteins were up-regulated, whereas 104 proteins were down-regulated in the spinal cord tissues. Three of the differentially expressed Heat shock proteins (HSPs) namely, Hsp90ab1, Hspa4 and Hspe1 were down-regulated. CONCLUSION: The differentially expressed proteins of spinal cord tissues after ASCI will provide scientific foundation for further study to explore the secondary injury mechanism of ASCI.

Treatment of HMX-production wastewater in an aerobic granular reactor.

Aerobic granules were applied to the treatment of HMX-production wastewater using a gradual domestication method in a SBR. During the process, the granules showed a good settling ability, a high biomass retention rate, and high biological activity. After 40 days of stable operation, aerobic granular sludge performed very effectively in the removal of carbon and nitrogen compounds from HMX-production wastewater. Organic matter removal rates up to 97.57% and nitrogen removal efficiencies up to 80% were achieved during the process. Researchers conclude that using aerobic granules to treat explosive wastewater has good prospects for success.

Self-assembly of rod-coil multiblock copolymers: a strategy for creating hierarchical smectic structures.

We extended self-consistent field theory to explore self-assembly behavior of linear multiblock copolymers consisting of alternative rod and coil blocks. Such rod-coil multiblock copolymers are found to be capable of self-assembling into hierarchical smectic microstructures. For the copolymers with long rod end block, lamellae-in-lamellar structures containing two smectic C phases at small and large length scales were observed. It was found that the hierarchical smectic structures exhibit not only double periodicities in overall structure but also double orientational orders of rod blocks. Additionally, these hierarchical smectic structures can be tailed by tuning the relative length of the coil blocks. For the copolymers with long coil end block, the multiblock copolymers can self-assemble into hierarchical lamellar structures with smectic phases only at the small length scale. The findings gained through the present study may offer valuable information for understanding the self-assembly behavior of complicated rod-coil copolymers and designing polymeric materials with advanced properties.

Self-assembly of a mixture system containing polypeptide graft and block copolymers: experimental studies and self-consistent field theory simulations.

Self-assembly behavior of mixture systems containing poly(γ-benzyl-L-glutamate)-poly(ethylene glycol) graft (PBLG-g-PEG) and block (PBLG-b-PEG) copolymers in aqueous solution was investigated by both experiments and computer simulations. Pure graft copolymers self-assembled into vesicles, and pure block copolymers aggregated into spherical micelles or vesicles, while, for the mixture systems, hybrid cylindrical micelles were observed. In addition to the experimental observations, self-consistent field theory (SCFT) simulations were performed on the self-assembly behavior of graft/block copolymer mixtures. Simulation results reproduced the morphological transitions observed in the experiments. Moreover, from the SCFT simulations, the chain distributions of copolymers in the aggregates were obtained. For the hybrid cylindrical micelles, block copolymers were found to mainly locate at the ends of aggregates, which prevents the fusion of cylinders to vesicles. By combining experimental findings with simulation results, the mechanism regarding the morphological transition of the aggregates formed by graft/block copolymer mixtures is proposed.

Ordered nanostructures self-assembled from block copolymer tethered nanoparticles.

Combining the self-consistent field theory (SCFT) and the density functional theory (DFT), we investigated the self-assembly behavior of AB diblock copolymer tethered single spherical particle P (ABP molecules). Two cases were studied: one is where the particles are chemically neutral to both A and B blocks, and the other is where the particles are unfavorable to neither of the two blocks. For neutral particles, the ABP molecules self-assemble to typical equilibrium microstructures, such as lamellae and cylinders. The P particles are localized in B block domains, and the size of particles can influence the phase behavior. For unfavorable particles, the ABP molecules microphase separate to form distinct ordered structures. Hierarchical structures, such as cylinders with cylinders at the interfaces and lamellae with cylinders at the interfaces, were observed. These resulting hierarchical structures are mainly determined by two parameters: A block fraction f(A) and particle size R(P). On the basis of the calculation results, phase diagrams were constructed.