Search

Abstract Background The growing escalation of soil salinization is tremendously threatening the global food security and the development of sustainable agriculture. To address the worldwide predicament caused by salt stress toward crops, combining nanotechnology with the merits of plant hormone may become an efficient and effective approach. Results In this work, a sustained release agent system (BR@MSN) was developed by loading brassinolide (BR) to mesoporous silica nanoparticles (MSN) to enhance the salt stress resistance of cucumber seeds and seedlings. The obtained BR@MSN agent was about 120 nm. As an endogenous plant hormone, promotion in crop growth was found at low BR concentration. Due to the sustained release property, BR@MSN avoided excessive BR exposure to seeds and seedlings to cause inhibitory effects. After the soil application of BR@MSN, the promotion effect from BR combined with the regulation enhancement from MSN nanocarrier improved the seed germination rate by 11.76% under saline environment. Compared with the same BR concentration (2.0 mg/L), BR@MSN increased the seed germination rate even by 1324.29%. In addition, remarkable wettability on foliar surfaces was found, and the foliar application of BR@MSN significantly enhanced the salt stress resistance of cucumber seedlings by alleviating the accumulation of reactive oxygen species (ROS) and increasing the cell viability along with the improvement in superoxide dismutase (SOD) activity (234.11%), the decrease in malondialdehyde (MDA) content (61.30%), and the increase in chlorophyll content (110.88%). Conclusions The newly developed BR@MSN agents could effectively enhance the salt stress resistance of crop seeds and seedlings, and their applications significantly improved the seed germination rate and seedling growth. The remarkable efficacy makes this BR@MSN agent system potential in agricultural field for enhancing the salt stress resistance of crops and facilitating the development of sustainable agriculture. Graphical Abstract

Abstract The Jilin clawed salamander (Onychodactylus zhangyapingi) is an endemic, endangered, and level‐two protected amphibian species of China. In the context of serious threats to amphibians worldwide, conservation studies of this endangered species are urgently needed. In this study, mitogenomic conservation genetics and species distribution modeling analyses were performed for O. zhangyapingi. Sixty‐three samples were collected from nine different locations, and the complete mitochondrial genome was sequenced. Population genetic analyses revealed that O. zhangyapingi exhibits only one genetic structure with extremely low nucleotide diversity. Late Pleistocene climate cooling may have led to a reduction in effective population size and extremely low mitogenomic nucleotide diversity in this salamander, and the subsequent temperature increase (~20 kya to present) provided the opportunity for rapid population growth. The continuous highly suitable region for O. zhangyapingi is only approximately 3000 km2 on the southeastern boundary of Jilin Province, China. Fortunately, there are three large forested national nature reserves within the distribution of O. zhangyapingi that can effectively protect endangered species. Our findings suggest that O. zhangyapingi is a vulnerable species with a narrow distribution and extremely low genetic diversity, and we should pay more attention to the conservation management of this species.

Background: Identifying germline mutations in BRCA1 and BRCA2 genes (BRCAs) would benefit the carriers in multiple aspects. In addition to single-nucleotide variations and small indels, copy number variations (CNVs) is also an indispensable component of identifiable mutations in BRCAs. A sensitive, rapid and throughput-flexible method to detect CNVs would be preferred to meet the rising clinical requirements for BRCAs testing.Methods: We developed a MALDI-TOF-MS-based method (MS assay) which included three steps: first, multiplex end-point PCR followed by a single base extension reaction; second, automated analyte transfer and data acquisition; third, data analysis. We applied MS assay to detect CNVs in BRCAs in 293 Chinese patients with ovarian or pancreatic cancer. All the samples were examined by targeted next-generation sequencing (TS) simultaneously. Samples were further cross-validated by multiplex ligation-dependent probe amplification (MLPA) if the results from MS assay and TS were inconsistent. Long range PCR was then applied to identify the exact breakpoints in BRCAs.Results: MS assay introduced highly multiplexed panels to detect CNVs of BRCAs semi-quantitatively. Simplified on-board data analysis was available for MS assay and no complex bioinformatics was needed. The turnaround time of MS assay was less than 8 hours with a hands-on time of only 40 min. Compared to TS, MS assay exhibited higher sensitivity (100% vs. 75%) and was more flexible in throughput, with the reagent cost per sample remaining constant no matter how many samples were examined per assay. A total of eight CNVs in BRCAs were detected from the 293 samples, and the molecular breakpoints were successfully identified in five samples through long-range PCR followed by Sanger sequencing.Conclusion: Our results suggested that MS assay might be an effective method in primary screening for CNVs in genes such as BRCAs, especially when short turnaround time and/or high sensitivity is a top priority.

Abstract Mediation by sulphate-reducing bacteria (SRB) is responsible for pyrite (FeS2) formation. The origin of the Dachang tin polymetallic ore field is related to the mineralisation of submarine hydrothermal vent sediments. Here, we investigated SRB in these ores via morphological, chemical, and isotopic analyses. Polarised and scanning electron microscopy indicated that trace SRB fossils in the metal sulphide ore were present in the form of tubular, beaded, and coccoidal bodies comprising FeS2 and were enclosed within a pyrrhotite (FeS) matrix in the vicinity of micro-hydrothermal vents. The carbon (C), nitrogen (N), and oxygen (O) contents in the FeS2 synthesised by SRB were high, and a clear biological Raman signal was detected. No such signals were discerned in the peripheral FeS. This co-occurrence of FeS, FeS2, and the remains of bacteria (probably chemoautotrophic bacteria) was interpreted as the coprecipitation process of SRB-mediated FeS2 formation, which has, to the best of our knowledge, not been reported before. Our study also illustrates that combined energy-dispersive X-ray spectroscopy, Raman spectroscopy, and isotopic analysis can be used as a novel methodology to document microbial-mediated processes of mineral deposition in submarine hydrothermal vent ecology on geological time scales.

Abstract Background There is a serious global problem of salinization of arable land, causing large reduction in world food production. Use of plant hormones is an effective way to reduce damage caused to crops and salt stress. Results In this study, PEI-EDA was modified with AM-zein and grafted with plant hormone SA (AM-zein-SA) and used as a nano-pesticide carrier to load emamectin benzoate (EB). The use of AM-zein-SA as a nano-pesticide carrier could reduce the damage caused by salt stress to crops. The structure of AM-zein-SA was characterized by FTIR, UV, fluorescence, Raman, and 1H NMR spectroscopic techniques. AM-zein-SA could effectively improve the resistance of EB to ultraviolet radiations, resistance of cucumber to salt stress, and the absorption of EB by plants. The experimental results showed that AM-zein-SA could effectively improve the anti-UV property of EB by 0.88 fold. When treated with 120 mmol NaCl, the germination rate of cucumber seeds under salt stress increased by 0.93 fold in presence of 6.25 mg/L carrier concentration. The POD and SOD activities increased by 0.50 and 1.21 fold, whereas the content of MDA decreased by 0.23 fold. In conclusion, AM-zein-SA nano-pesticide carrier could be used to improve the salt resistance of crops and the adhesion of pesticides to leaves. Conclusion AM-zein-SA, without undergoing any changes in its insecticidal activity, could simultaneously improve the salt stress resistance and salt stress germination rate of cucumber, reduce growth inhibition due to stress under high-concentration salt, and had a good effect on crops. In addition, EB@AM-zein-SA obviously improved the upward transmission rate of EB, as compared with EB. In this study, SA was grafted onto zein-based nano-pesticide carrier, which provided a green strategy to control plant diseases, insects, and pests while reducing salt stress on crops in saline-alkali soil. Graphical Abstract

Under the requirements of China's strategic goal of ''carbon peaking and carbon neutrality'', as a renewable, clean and efficient secondary energy source, hydrogen benefits from abundant resources, a wide variety of sources, a high combustion calorific value, clean and non-polluting, various forms of utilization, energy storage mediums and good security, etc. It will become a realistic way to help energy, transportation, petrochemical and other fields to achieve deep decarbonization, and will turn into an important replacement energy source for China to build a modern clean energy system. It is clear that accelerating the development of hydrogen energy has become a global consensus. In order to provide a theoretical support for the accelerated transformation of hydrogen-related industries and energy companies, and provide a basis and reference for the construction of ''Hydrogen Energy China'', this paper describes main key technological progresses in the hydrogen industry chain such as hydrogen production, storage, transportation, and application. The status and development trends of hydrogen industrialization are analyzed, and then the challenges faced by the development of the hydrogen industry are discussed. At last, the development and future of the hydrogen industry are prospected. The following conclusions are achieved. (1) Hydrogen technologies of our country will become mature and enter the road of industrialization. The whole industry chain system of the hydrogen industry is gradually being formed, and will realize the leap-forward development from gray hydrogen, blue hydrogen to green hydrogen. (2) The overall development of the entire hydrogen industry chain such as hydrogen production, storage and transportation, fuel cells, hydrogen refueling stations and other scenarios should be accelerated. Besides, in-depth integration and coordination with the oil and gas industry needs more attention, which will rapidly promote the high-quality development of the hydrogen industry system. (3) The promotion and implementation of major projects such as ''north-east hydrogen transmission'', ''west-east hydrogen transmission'', ''sea hydrogen landing'', and utilization of infrastructures such as gas filling stations, can give full play to the innate advantages of oil and gas companies in industrial chain nodes such as hydrogen production and refueling, etc., which can help to achieve the application of ''oil, gas, hydrogen, and electricity'' four-station joint construction, form a nationwide hydrogen resource guarantee system, and accelerate the planning and promotion of the ''Hydrogen Energy China'' strategy.

Contact-dependent growth inhibition (CDI) is an important mechanism of bacterial competition. Here, Bartelli et al. show that proteolytic processing of a CDI toxin induces a conformational switch required for translocation into target bacteria.

Abstract The green synthesis of nano‐silver (NS) has gained increasing attention owing to its cost‐effectiveness and environmental friendliness. Herein, a novel one‐step green preparation method of stable NS aqueous solution using Tollens reagent as the silver ion source, D‐fructose as the reduction agent, and polyvinyl pyrrolidone as the stabilizing and capping agent is reported. The prepared NS solution had a pH value of 7.10, with approximately spherical NS particles in the range of 13.95–87.36 nm. The resulting NS solution was stable under normal temperature, boiling water bath, and acidic environment. The NS solution had a remarkable absorption peak at 410 nm in its ultraviolet–visible spectrum. The dynamic light scattering/Zeta analysis showed the average particle size of the NS aqueous solution was 183.5 nm, polymer dispersion index was 0.282, and the zeta potential of the green synthesized NS was –18.0 mV. Moreover, the NS solution exerted a strong inhibitory effect on the growth of the bacteria isolated from the vase water of cut carnation ‘Prince’ flowers. These findings indicate that the obtained NS solution is potentially a practical and effective antibacterial agent for preserving cut carnations and other cut flowers.

Aiming at the problems of low rigidity， large accumulated error， and limited high-speed and heavy load in the application of serial robots in the constant force grinding processing industry， a five-degree-of-freedom parallel robot composed of 4-UPS/PPS composed of four sets of the same UPS drive branch chain and one PPS restraint branch chain is proposed， the robot movement in two-dimensional plane and rotation in three-dimensional space are realized. The X-direction constraint degrees of freedom of robot is analyzed through the DH parameter method， the mapping relationship between the moving platform pose and the driving branch is determined according to the robot kinematics inverse solution equation. The robot workspace constraint equation and objective function equation are established， the tool end space pose are analyze， and spatial scatter diagrams and three-dimensional diagrams are drawn. By using Adams simulation software to compare the numerical solution and the simulation solution analysis curve， it can be seen that the robot driving branch runs smoothly and the theoretical analysis is correct. It also provides a theoretical and technical basis for the practical application of parallel robots in the field of constant force grinding.

Background and objectivesDiabetes mellitus is a serious metabolic disease that causes a serious economic burden worldwide. Gut flora is a major component of diabetes research, and the aim of this study was to understand the trends and major components of research related to diabetes and gut flora in the last 11 years.MethodsWe searched the Web of Science Core Collection database for articles on diabetes and gut flora related research from 2011-2021 on July 2, 2022. The literature data were analyzed for country, institution, author, steward, journal, and highly cited literature using Citespace.5.8.R3 and Vosviewer1.6.17.ResultsFinally 4834 articles that met the requirements were included. The overall trend of articles published in the last 11 years is increasing, and the trend of articles published after 2019 is increasing significantly. In total, 109 countries, 4820 institutions, and 23365 authors were involved in the field of research. The highest number of publications was 1262 articles from the United States, the institution with the most publications was the University of Copenhagen with 134 articles, and the author with the most publications was PATRICE D CANI with 52 articles.ConclusionThe number of studies related to diabetes and intestinal flora is increasing and more and more researchers are involved in this field. Intestinal flora provides a key research direction for the treatment of diabetes. In the future, gut flora will remain the focus of the diabetes field.

Background and aimUlcerative colitis is a chronic inflammatory bowel disease, and intestinal flora plays an important role in ulcerative colitis. In this study, we conducted a bibliometric analysis of publications in the field of intestinal flora and ulcerative colitis research in the past 10 years to summarize the current status of the field and analyze the trends in the field.MethodsOn July 15, 2022, we chose the Web of Science Core Collection database as the study’s data source. CiteSpace.5.8.R3 and VOSviewer 1.6.17 were used to examine publications of research on intestinal flora and ulcerative colitis that were published between 2012 and 2021. We looked through the papers for journals, organizations, nations and regions, authors, and key terms.ResultsThis analysis covered a total of 2,763 papers on studies into intestinal flora and ulcerative colitis. There were 13,913 authors, 93 nations, 3,069 organizations, and 759 journals in all of the articles. In the USA, 767 publications were the most. The university with the most publications was Harvard Medical School. The author with the most articles was Antonio Gasbarrini.ConclusionThis study summarizes the global research trends in intestinal flora and ulcerative colitis. Publications in this field have increased year by year in the last decade and the field of research on intestinal flora and ulcerative colitis has good prospects for growth.

The Mo/Si multilayer mirror has been widely used in EUV astronomy, lithography, microscopy and other fields because of its high reflectivity at the wavelength around 13.5 nm. During the fabrication of Mo/Si multilayers on large, curved mirrors, shadow mask was a common method to precisely control the period thickness distribution. To investigate the effect of shadow mask on the microstructure of Mo/Si multilayers, we deposited a set of Mo/Si multilayers with and without the shadow mask on a curved substrate with aperture of 200 mm by direct current (DC) magnetron sputtering in this work. Grazing incidence X-ray reflectivity (GIXR), diffuse scattering, atomic force microscope (AFM) and X-ray diffraction (XRD) were used to characterize the multilayer structure and the EUV reflectivity were measured at the National Synchrotron Radiation Laboratory (NSRL) in China. By comparing the results, we found that the layer microstructure including interface width, surface roughness, layer crystallization and the reflectivity were barely affected by the mask and a high accuracy of the layer thickness gradient can be achieved.

Montmorillonite K-10 clay (MMT) was surface-modified by sodium dodecyl sulfate (SDS) and grafted with KH-550 coupling agent to construct "Hy-MMT" organic modified structure in one step with hydrothermal-assist. Different sustained release systems were prepared through changing the temperature during the hydrothermal process. The characterization results illustrated the mechanism of the hydrothermal assist in intercalation during the organic modification. It was also proved that the triazolone loaded in the sustained release system existed as homogeneous in the pores as amorphous state by DSC analysis. According to SEM and TEM observation, the surface of original MMT or modified MMT without hydrothermal assist presented rough particles, which belonged to the SDS and KH-550 without intercalation into the layer structure which is in accordance with the contact angles of the samples. The experimental results indicated that the adsorption capacity (AC) of Hy-60-MMT showed the best due to its mild react condition the successfully intercalated by SDS and KH-550 by the assist of the hydrothermal treatment. Its AC for triazolone was significantly increased to 29.8 mg/g comparing to MMT without modification which showed no capacity for triazolone adsorption. The as-synthesized system also showed significant pH sensitivity with a sequence of pH = 7 > pH = 3 > pH = 5 > pH = 9 in release speed indicating that the sustained release system can be well stored in mild acid or basic environment and activated while sprayed into earth or plants under neutral condition.

Blur detection is aimed at estimating the probability of each pixel being blurred or non-blurred in an image affected by motion or defocus blur. This task has gained considerable attention due to its promising application fields in computer vision. Accurate differentiation of anomalous regions (including the sharp but homogeneous regions and pseudo-sharp backgrounds) and motion-blurred regions are main challenges in blur detection, in which both conventional and recently developed blur detection methods have limited performance and low time efficiency. To address these issues, this paper develops an accurate and fast blur detection method for both motion and defocus blur using a new end-to-end deep neural network. First, a novel multi-input multi-loss encoder-decoder network (M-shaped) is proposed to learn rich hierarchical representations related to blur. Then, to resolve the problem shows that blur degree is susceptible to scales, we construct a pyramid ensemble model (PM-Net) consisting of different scales of M-shaped subnets and a unified fusion layer. The experiments demonstrate that the proposed PM-Net can accurately handle those challenging scenarios with anomalous regions for both defocus and motion blur. Our method performs better than previous state-of-the-art methods. It achieves the $F_{1}$ -score of 0.893 for only defocus blur and 0.884 for joint motion and defocus blur, both of which significantly surpass previous methods on the benchmark BDD dataset. We also test our PM-Net on another public CDD dataset composed of challenging defocused images. The proposed method also outperforms other published methods with an $F_{1}$ -score of 0.885. In addition, our proposed method is hundreds of times faster (millisecond) than other state-of-the-art methods (second). Moreover, our experiments also demonstrate that the PM-Net is robust to noise and has a good generalization property.

The mesoporous silica modified by salicylaldimine was prepared through a co-condensation method. Through the bridge effect from metal ion (copper ion, zinc ion, manganese ion), the model drug-avermectin was supported on the metal-Schiff base functionalized mesoporous silica (M-MCM-41) to form a highly efficient adsorbents for pesticidedelivery and removal. The experimental results showed that the sequence in adsorption capacity (AC) for avermectin (AVM) of various mesoporous silica in different adsorption time was Zn-MCM-41 > Cu-MCM-41 > Mn-MCM-41 > MCM-41 > SA-MCM-41. The AC of Zn-MCM-41 was 151 mg/g, while the MCM-41 was 78 mg/g which increased nearly 100 % after modification due to its strongest coordination ability. The FT-IR and XPS results confirmed the existence of coordination bond between SA-MCM-41 and metal ions as well as the coordination bond between M-MCM-41 and avermectin. The kinetic data and the equilibrium isotherms are modeled by three kinetic models, the pseudo-first-order, the pseudo-second-order and intraparticle diffusion, and two isotherm models, Langmuir and Freundlich, respectively. The kinetic mechanism of the adoption changed from physical adsorption to the intraparticle diffusion due to the stronger interaction between avermectin and the mesoporous silica through coordination. Adsorption isotherm of the samples were well-represented by Freundlich model which indicated that the adsorption was reversible.

For the application of parallel robots in the grinding industry, a parallel robot equipped with a constant force actuator that produces a constant force for grinding is designed. To study the characteristics of the parallel robot’s spatial positions and poses, the inverse solutions of the moving platform’s spatial positions and poses as well as the workspace where objects were ground were established by using DH parameters and geometric methods. The experimental results showed that the workspace where objects were ground was a cylinder with a cross section similar to a symmetric circular sector. To analyze the characteristics of the forces produced by the parallel robotic system, the dynamics equation was established via the Newton–Euler method to verify the rationality of the force decoupling design. Theoretical calculation combined with simulation and experimental analyses confirmed the viability of the theoretical analyses which lay a theoretical foundation for the design, manufacture and control of the parallel robotic system proposed in this paper.

Abstract Background Neurogenic bowel dysfunction (NBD) is a major physical and psychological problem in patients with spinal cord injury (SCI), and gut dysbiosis is commonly occurs in SCI. Here, we document neurogenic bowel management of male patients with chronic traumatic complete SCI in our centre and perform comparative analysis of the gut microbiota between our patients and healthy males. Methods A total of 43 male patients with chronic traumatic complete SCI (20 with quadriplegia and 23 with paraplegia) and 23 healthy male adults were enrolled. Clinical data and fresh stool specimens were collected from all participants. Face-to-face interviews were conducted to survey the neurogenic bowel management of 43 patients with SCI. Gut microbiomes were analysed by sequencing of the V3–V4 region of the 16S rRNA gene. Results NBD was common in adult male patients with chronic traumatic complete SCI. Patients with quadriplegia exhibited a longer time to defecate than did those with paraplegia and had higher NBD scores and heavier neurogenic bowel symptoms. The diversity of the gut microbiota in the SCI group was reduced, and the structural composition was different from that of the healthy adult male group. The abundance of Veillonellaceae and Prevotellaceae increased, while Bacteroidaceae and Bacteroides decreased in the SCI group. The abundance of Bacteroidaceae and Bacteroides in the quadriplegia group and Acidaminococcaceae, Blautia, Porphyromonadaceae, and Lachnoclostridium in the paraplegia group were significantly higher than those in the healthy male group. Serum biomarkers (GLU, HDL, CR, and CRP), NBD defecation time and COURSE had significant correlations with microbial community structure. Microbial community structure was significantly associated with serum biomarkers (GLU, HDL, CR, and CRP), NBD defecation time, and COURSE. Conclusions This study presents a comprehensive landscape of the gut microbiota in adult male patients with chronic traumatic complete SCI and documents their neurogenic bowel management. Gut microbiota dysbiosis in SCI patients was correlated with serum biomarkers and NBD symptoms.

Carboxymethyl cellulose (CMC) was grafted onto the surface of soy protein isolate (SPI) to obtain soy protein isolate-carboxymethyl cellulose conjugate (SPC). Avermectin (AVM) was hydrophobically encapsulated as a model drug to obtain SPC@AVM. The reaction between SPI and CMC was confirmed by infrared spectroscopy, thermal analysis and SDS-PAGE electrophoresis. The results of scanning electron microscopy showed that the average particle size of the drug-loaded microspheres was 129 nm and the shape of microspheres changed from block to spherical after the addition of AVM. After encapsulation of AVM, the absolute value of zeta potential was greater than 15 mV, which indicated better stability. Compared to AVM solution, SPC@AVM showed more wettability on the leaf surface and the contact angle on the leaves decreased from 71.64° to 57.33°. The maximum liquid holding capacity increased by 41.41%, from 8.85 to 12.52 mg cm−2, which effectively reduced leaf loss. SPC@AVM also prevented UV photolysis, wherein the half-life was extended from 18 to 68 min when exposed to UV light. Moreover, toxicity tests showed that the encapsulation of AVM was beneficial to retain the insecticidal effect of AVM in the presence of ultraviolet light. The release rate of AVM showed pH responsiveness and the release rate under neutral conditions was faster than acidic and alkaline conditions. Moreover, the process conformed to the Weibull model.

MCM-41 was prepared through the sol–gel method and encapsulated by polydopamine (PDA) before being coordinated with metal ions to form a highly efficient sustained release system (M-PDA–MCM-41) for triazolone delivery. The characterization results confirmed the existence of the coordination bond between the PDA layer and triazolone through the bridge effect from metal ions, which enhanced the interaction between PDA–MCM-41 and triazolone. The adsorption capacity of Fe-PDA–MCM-41 increased up to 173 mg g–1, which was 160% more than that of MCM-41. The sustained release performance of M-PDA–MCM-41 in different pH values was investigated. Under the conditions of pH ≤7, the release speed of triazolone increased with pH decreasing, whereas its release speed in the weak base condition was slower than in the neutral condition. Therefore, the as-synthesized system showed significant pH-sensitivity in the sustained release process, indicating that the sustained release system can be well stored in the neutral or basic environment and activated in the acid environment. Their sustained release curves described by the Korsmeyer–Peppas equation at pH 7 showed the same behaviour, indicating that PDA decoration or metal ion coordination only increases the steric hindrance and the interaction between carrier and triazolone instead of changing the original structure of the pure MCM material in accordance with X-ray diffraction and Brunauer-Emmett-Teller analysis results.

Summary: The fragile X mental retardation protein FMRP regulates translation of its bound mRNAs through incompletely defined mechanisms. FMRP has been linked to the microRNA pathway, and we show here that it associates with the RNA helicase MOV10, also associated with the microRNA pathway. FMRP associates with MOV10 directly and in an RNA-dependent manner and facilitates MOV10’s association with RNAs in brain and cells, suggesting a cooperative interaction. We identified the RNAs recognized by MOV10 using RNA immunoprecipitation and iCLIP. Examination of the fate of MOV10 on RNAs revealed a dual function for MOV10 in regulating translation: it facilitates microRNA-mediated translation of some RNAs, but it also increases expression of other RNAs by preventing AGO2 function. The latter subset was also bound by FMRP in close proximity to the MOV10 binding site, suggesting that FMRP prevents MOV10-mediated microRNA suppression. We have identified a mechanism for FMRP-mediated translational regulation through its association with MOV10. : Kenny et al. show that FMRP recruits the helicase MOV10 to mRNAs for translation regulation. MOV10 and FMRP modulate AGO association with RNAs, and all three proteins bind near microRNA recognition elements. MOV10 usually facilitates microRNA-mediated regulation; however, proximal binding of FMRP blocks AGO association to allow translation.

Nonmembrane-bound organelles that behave like liquid droplets are widespread among eukaryotic cells. Their dysregulation appears to be a critical step in several neurodegenerative conditions. Here, we report that tau protein, the primary constituent of Alzheimer neurofibrillary tangles, can form liquid droplets and therefore has the necessary biophysical properties to undergo liquid-liquid phase separation (LLPS) in cells. Consonant with the factors that induce LLPS, tau is an intrinsically disordered protein that complexes with RNA to form droplets. Uniquely, the pool of RNAs to which tau binds in living cells are tRNAs. This phase state of tau is held in an approximately 1:1 charge balance across the protein and the nucleic acid constituents, and can thus be maximal at different RNA:tau mass ratios, depending on the biopolymer constituents involved. This feature is characteristic of complex coacervation. We furthermore show that the LLPS process is directly and sensitively tuned by salt concentration and temperature, implying it is modulated by both electrostatic interactions between the involved protein and nucleic acid constituents, as well as net changes in entropy. Despite the high protein concentration within the complex coacervate phase, tau is locally freely tumbling and capable of diffusing through the droplet interior. In fact, tau in the condensed phase state does not reveal any immediate changes in local protein packing, local conformations and local protein dynamics from that of tau in the dilute solution state. In contrast, the population of aggregation-prone tau as induced by the complexation with heparin is accompanied by large changes in local tau conformations and irreversible aggregation. However, prolonged residency within the droplet state eventually results in the emergence of detectable β-sheet structures according to thioflavin-T assay. These findings suggest that the droplet state can incubate tau and predispose the protein toward the formation of insoluble fibrils.

Using butyl methacrylate (BMA) and styrene (St) as monomers and divinylbenzene (DVB) as a crosslinking agent, P(St-BMA) microspheres were prepared by suspension polymerization. Tea tree oil (TTO) microspheres were prepared by adsorbing TTO on P(St-BMA) microspheres. The structure and surface morphology of P(St-BMA) microspheres and TTO microspheres were characterized by Fourier transformed infrared spectroscopy (FTIR), optical microscopy, and Thermogravimetric analysis (TGA). In doing so, the structural effect of P(St-BMA) microspheres on oil absorption and sustained release properties could be investigated. The results show that the surface of the P(St-BMA) microspheres in the process of TTO microsphere formation changed from initially concave to convex. The TTO microspheres significantly improved the stability of TTO, which was found to completely decompose as the temperature of the TTO increased from about 110 °C to 150 °C. The oil absorption behavior, which was up to 3.85 g/g, could be controlled by adjusting the monomer ratio and the amount of crosslinking agent. Based on Fickian diffusion, the sustained release behavior of TTO microspheres was consistent with the Korsmeyer-Pappas kinetic model. After 13 h of natural release, the anti-bacterial effect of the TTO microspheres was found to be significantly improved compared to TTO.

Salicylaldimine-modified mesoporous silica (Sal-MCM-3 and Sal-MCM-9) was prepared through a co-condensation method with different amounts of added salicylaldimine. With the coordination from the salicylaldimine, zinc ions were impregnated on Sal-MCM-3 and Sal-MCM-9. Then, Zn-Sal-MCM-3 and Zn-Sal-MCM-9 were calcined to obtain nano-zinc oxide loaded on mesoporous silica (ZnO-MCM-3 and ZnO-MCM-9). The material structures were systematically studied by Fourier transform infrared spectroscopy (FTIR), N2 adsorption/desorption measurements, X-ray powder diffraction (XRD), zeta potential, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet diffused reflectance spectrum (UV-vis DRS), and thermogravimetry (TGA). Methyl orange (MO) was used to investigate the photocatalysis behavior of ZnO-MCM-3 and ZnO-MCM-9. The results confirmed that nano ZnO was loaded in the channels as well as the outside surface of mesoporous silica (MCM-41). The modification of salicylaldimine helped MCM-41 to load more nano ZnO on MCM-41. When the modification amount of salicylaldimine was one-ninth and one-third of the mass of the silicon source, respectively, the load of nano ZnO on ZnO-MCM-9 and ZnO-MCM-3 had atomic concentrations of 1.27 and 2.03, respectively. ZnO loaded on ZnO-MCM-9 had a wurtzite structure, while ZnO loaded on ZnO-MCM-3 was not in the same crystalline group. The blocking effect caused by nano ZnO in the channels reduced the orderliness of MCM-41. The photodegradation of MO can be divided in two processes, which are mainly controlled by the surface areas of ZnO-MCM and the loading amount of nano ZnO, respectively. The pseudo-first-order model was more suitable for the photodegradation process.

Bacterial chemotaxis is one of the best studied signal transduction pathways. CheW is a scaffold protein that mediates the association of the chemoreceptors and the CheA kinase in a ternary signaling complex. The effects of replacing conserved Arg62 of CheW with other residues suggested that the scaffold protein plays a more complex role than simply binding its partner proteins. Although R62A CheW had essentially the same affinity for chemoreceptors and CheA, cells expressing the mutant protein are impaired in chemotaxis. Using a combination of molecular dynamics simulations (MD), NMR spectroscopy, and circular dichroism (CD), we addressed the role of Arg62. Here we show that Arg62 forms a salt bridge with another highly conserved residue, Glu38. Although this interaction is unimportant for overall protein stability, it is essential to maintain the correct alignment of the chemoreceptor and kinase binding sites of CheW. Computational and experimental data suggest that the role of the salt bridge in maintaining the alignment of the two partner binding sites is fundamental to the function of the signaling complex but not to its assembly. We conclude that a key feature of CheW is to maintain the specific geometry between the two interaction sites required for its function as a scaffold.