Hydrophilic Nanocomposite Films with a Fence-Structure-Induced Labyrinth Effect for Greenhouse Cooling and Light Enhancement.

In this paper, we reported a new kind of cooling and light-enhanced hydrophilic nanocomposite film (PE/JW-0.8%) with low-density polyethylene (LDPE) as the substrate. The wetting, photophysical, and mechanical properties of PE/JW-0.8% were tested. The emission band of the fluorescence centers at 420 nm, which is perfectly consistent with the absorption spectrum of plant photosynthesis. In addition, light can be scattered by PE/JW-0.8% to achieve a larger light distribution area. PE/JW-0.8% showed a good durability of hydrophilicity in the water rinsing test. Meanwhile, the elongation at the break of the film was significantly increased. Benefiting from the fence structure induced labyrinth effect, a maximum reduction of 6.7 °C in temperature monitoring for PE/JW-0.8% was observed in the detailed field experiments. Light intensity monitoring showed that light intensity in PE/JW-0.8% increased by a maximum of 57.1% compared to PE/LH. In the biological quality analysis of melon, it was found that the soluble sugar, soluble solid, and vitamin C content of melon increased by 13.34, 22.96, and 50.95%, respectively. In conclusion, these results confirm that PE/JW-0.8% has great application potential in the field of facility agriculture, buildings, and photovoltaic modules.

Recent Advances of Molecularly Imprinted Polymers Based on Cyclodextrin.

Molecular imprinting polymers (MIPs), generally considered as artificial mimics that are comparable to natural receptor, are polymers with tailor-made specific recognition sites complementary to the template molecules in shape and size. As a class of supramolecular compounds, cyclodextrins (CDs) are flourishing in the field of molecular imprinting with their unique structural properties. This review presents recent advances in application of MIPs based on CDs during the past five years. The discussion is grouped according to the different role of CDs in MIPs, that is, functional monomer, carrier modifier, etc. Main focus is the application of CD-based MIP on sample preparation, detection, and sensing. Additionally, drug delivery with CD-based MIP is also briefly discussed. Finally, challenges and future prospects of application of CDs in MIP are elaborated.

Three-Dimensional CdS@Carbon Fiber Networks: Innovative Synthesis and Application as a General Platform for Photoelectrochemical Bioanalysis.

This Letter reports a novel synthetic methodology for the fabrication of three-dimensional (3D) nanostructured CdS@carbon fiber (CF) networks and the validation of its feasibility for applications as a general platform for photoelectrochemical (PEC) bioanalysis. Specifically, 3D architectures are currently attracting increasing attention in various fields due to their intriguing properties, while CdS has been most widely utilized for PEC bioanalysis applications because of its narrow band gap, proper conduction band, and stable photocurrent generation. Using CdS as a representative material, this work realized the innovative synthesis of 3D CdS@CF networks via a simple solvothermal process. Exemplified by the sandwich immunoassay of fatty-acid-binding protein (FABP), the as-fabricated 3D CdS@CF networks exhibited superior properties, and the assay demonstrated good performance in terms of sensitivity and selectivity. This work features a novel fabrication of 3D CdS@CF networks that can serve as a general platform for PEC bioanalysis. The methodology reported here is expected to inspire new interest for the fabrication of other 3D nanostructured Cd-chalcogenide (S, Se, Te)@CF networks for wide applications in biomolecular detection and beyond.

Effect of Four Types of Chemical Pretreatment on Enzymatic Hydrolysis by SEM, XRD and FTIR Analysis.

Catalpa sawdust was respectively pretreated by NaOH, Ca(OH)2, H2SO4 and HCl solution, and the enzymatic hydrolysis of catalpa sawdust was significantly enhanced by alkaline pretreatments. In order to investigate the mechanisms of pretreatment of catalpa sawdust, the characteristics of catalpa sawdust before and after pretreatments were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was found that the surface of catalpa sawdust was disrupted by four kinds of chemical pretreatment, and the pretreatment with Ca(OH)2 solution resulted in the most serious damage. The XRD results showed that part of amorphous regions was damaged by alkaline pretreatments, which led to a relative increase of crystallinity Index (CrI) of catalpa sawdust; while the CrI of catalpa sawdust was insignificantly influenced by acid pretreatments. The FTIR analysis displayed that the molecular structures of hemicellulose and lignin of catalpa sawdust were damaged in different degrees by four types of pretreatment. The significant improvement of enzymatic hydrolysis of catalpa sawdust after alkaline pretreatment might be attributed to the effective delignification of alkaline.

Construction of engineered 3D islet micro-tissue using porcine decellularized ECM for the treatment of diabetes.

Islet transplantation improves diabetes patients' long-term blood glucose control, but its success and utility are limited by cadaver availability, quality, and considerable islet loss after transplantation due to ischemia and inadequate angiogenesis. This study used adipose, pancreatic, and liver tissue decellularized extracellular matrix (dECM) hydrogels in an effort to recapitulate the islet sites inside the pancreas in vitro, and successfully generated viable and functional heterocellular islet micro-tissues using islet cells, human umbilical vein endothelial cells, and adipose-derived mesenchymal stem cells. The three-dimensional (3D) islet micro-tissues maintained prolonged viability and normal secretory function, and showed high drug sensitivity in drug testing. Meanwhile, the 3D islet micro-tissues significantly enhanced survival and graft function in a mouse model of diabetes. These supportive 3D physiomimetic dECM hydrogels can be used not only for islet micro-tissue culture in vitro, but also have great promise for islet transplantation for the treatment of diabetes.

A Soft Capsule for Magnetically Driven Drug Delivery Based on a Hard-Magnetic Elastomer Foam.

Drug delivery systems based on porous soft biomaterials have been widely reported because of stimuli-responsive drug release and their inherent reservoirs for drug storage. Especially, magnetic-responsive porous soft biomaterials achieve rapid and real-time control of drug release due to the magnetic field-triggered large deformation. However, the drug release profiles of these materials are difficult to predict and repeat, which restrict them from releasing drugs in the required dosage. Here, we report a soft capsule based on a flexible hard-magnetic elastomer foam (HEF) for magnetically controlled on-demand drug delivery. The HEF capsule contains an inner HEF and an outer elastomer shell. The HEF exhibits low elastic modulus (10 kPa) and highly interconnected pores (81% interconnected pores). Benefitting from the novel precompressed magnetization, the compressive deformation of HEF reaches 66%. Thus, an adjustable drug release rate ranging from 0.02 to 1.7 mL/min in the HEF capsule is achieved. The deformation-triggered drug release profiles of the HEF capsule under the magnetic field are accurately predicted, allowing 85% accuracy in drug dosage regulation and more than 90% maximum cumulative drug release. Especially, the HEF capsule is proven capable of acting as a soft robot to perform magnetically driven drug delivery in a human stomach model. HEF can potentially serve as a soft robot for biomedical applications in the human body.

Transcriptomic and physiological analyses reveal changes in secondary metabolite and endogenous hormone in ginger (Zingiber officinale Rosc.) in response to postharvest chilling stress.

Storing postharvest ginger at low temperatures can extend its shelf life, but can also lead to chilling injury, loss of flavor, and excessive water loss. To investigate the effects of chilling stress on ginger quality, morphological, physiological, and transcriptomic changes were examined after storage at 26 °C, 10 °C, and 2 °C for 24 h. Compared to 26 °C and 10 °C, storage at 2 °C significantly increased the concentrations of lignin, soluble sugar, flavonoids, and phenolics, as well as the accumulation of H2O2, O2-, and thiobarbituric acid reactive substances (TBARS). Additionally, chilling stress inhibited the levels of indoleacetic acid, while enhancing gibberellin, abscisic acid, and jasmonic acid, which may have increased postharvest ginger's adaptation to chilling. Storage at 10 °C decreased lignin concentration and oxidative damage, and induced less fluctuant changes in enzymes and hormones than storage at 2 °C. RNA-seq revealed that the number of differentially expressed genes (DEGs) increased with decreasing temperature. Functional enrichment analysis of the 523 DEGs that exhibited similar expression patterns between all treatments indicated that they were primarily enriched in phytohormone signaling, biosynthesis of secondary metabolites, and cold-associated MAPK signaling pathways. Key enzymes related to 6-gingerol and curcumin biosynthesis were downregulated at 2 °C, suggesting that cold storage may negatively impact ginger quality. Additionally, 2 °C activated the MKK4/5-MPK3/6-related protein kinase pathway, indicating that chilling may increase the risk of ginger pathogenesis.

Effect of erbium family laser etching on shear bond strength of enamel surfaces: A meta-analysis-PRISMA.

BACKGROUND: Recently, laser etching has appealed to people's attention. It is meaningful to compare the effect of erbium-doped yttrium-aluminum-garnet (Er:YAG) and erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSSG) laser etching parameters with acid etching on bond strength of enamel surfaces. As far as we know, there still remains no related meta-analysis. To evaluate the efficacy of Er:YAG and Er,Cr:YSSG lasers etching on shear bond strength (SBS) of brackets bonded to enamel. The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, conducted with literature search. METHODS: Twelve relevant randomized controlled trials (RCTs) were included. RESULTS: The pooled analysis of SBS showed that there were no significant differences between erbium family lasers and acid etching. In the mass, we noticed they did not achieve statistical significance in the lasers etching and acid etching. However, pooled analysis of 5 studies showed the SBS bonding to enamel was lower in Er,Cr:YAG laser group compared with acid group. As a whole, there were statistical significance between erbium lasers groups and acid etching group in adhesive remnant index (ARI) aspects, which less adhesives remained can reduce damage to enamel. With regard to the rate of teeth with ARI score ≤2, the results in Er:YAG laser etching group were obviously higher than acid etching group. CONCLUSION: Our data indicated that erbium lasers may be considered bonding of brackets to enamel instead of acid etching bonding to enamel.

A review: Development and application of surface molecularly imprinted polymers toward amino acids, peptides, and proteins.

Molecularly imprinted polymers (MIPs) have received wide interests in the bioanalysis field as "artificial antibodies". They can mimic biological receptors by selectively recognizing and adsorbing target molecules owing to their specific affinity to the targets. Traditional MIPs obtained by bulk imprinting have some defects, including low adsorption capacity, poor site accessibility, restricted mass transfer, and irregular morphology, which limit their development. Surface molecularly imprinted polymers (SMIPs) show the features of large surface area, allow fast mass transfer, and have high adsorption capacity and efficiency. They have been intensively used in the research of amino acids, peptides, and proteins due to these advantages. In this review, we systematically summarize the preparation of SMIPs including components and polymerization strategies, and their applications focusing on amino acids, peptides, and proteins are discussed in detail. Finally, future trends and challenges for the design and development of SMIPs are described.

Human activities affect the multidecadal microplastic deposition records in a subtropical urban lake, China.

Microplastic deposition in subtropical lakes and the influences of human activities remain to be deeply and fully understood. Owing to the intensification of urban construction and population growth, urban lakes serving as significant freshwater resources for sustainable development of the regional economy are becoming degraded, especially due to microplastic pollution. To understand the deposition characteristics of microplastics in lake sediments from the China's subtropical city, six sediment core samples were collected from Xinghu Lake of Guangdong Province. Here, we analyzed the morphological characteristics of microplastics from the perspective of microstructure, and investigated the temporal and spatial distribution patterns of microplastics on the macroscopic scale. The deposition characteristics of microplastics in the past 64 years and the influence of socio-economic factors on the accumulation of microplastics were further clarified through the isotope composition of cesium-137 and lead-210 in the subtropical urban area with intense human activities. The results showed that the microplastic concentration of sediment cores in Xinghu Lake was 523 ± 140 particles/kg. The average sizes of microplastics in the five sub-lakes (i.e., Bohai, Zhongxin, Li, Qinglian, and Xiannü Lakes) of Xinghu Lake were 668, 642, 727, 708 and 646 µm, respectively. There were 25 polymers in sediment cores of Xinghu Lake. Rayon, polypropylene, polyethylene terephthalate and polypropylene-polyethylene copolymer were the main types, and the microplastics have the aging phenomenon or mechanical abrasion. The average deposition rates of sediment and microplastics were 0.6 cm/a and 106 particles/(kg·a) in Xinghu Lake, respectively. Meanwhile, the urban expansion and economic growth, as indicated by the increase in the urban area, population and gross domestic product, all played an essential role in the accelerated accumulation of microplastics in sediment cores of Xinghu Lake.

Adsorption characteristics of lignosulfonates in salt-free and salt-added aqueous solutions.

Five sodium lignosulfonate (SL) fractions with narrow molecular weight distribution and known salt content were used as the polyanion to build up layer-by-layer self-assembly multilayers with poly(diallyldimethylammonium chloride) (PDAC) as polycation. It is interesting to find that the salt-free SL is hardly adsorbed on the PDAC surface, but the SL in salt-added solutions can be self-assembled well with PDAC to form SL/PDAC multilayers. When the five SL fractions dissolved in saline solutions are adsorbed on the PDAC surface by a self-assembly technique, SL with higher M(w) shows a higher adsorption amount than does SL with lower M(w). The driving forces of self-assembly of SL and PDAC are discussed based on the solution behaviors and adsorption characteristics of SL in salt-free and salt-added aqueous solutions. A possible self-assembled mechanism of SL and PDAC is electrostatic or cation-π interactions, but the SL cannot be adsorbed onto the PDAC surface without a hydrophobic interaction. With the addition of enough salt, the Coulomb interaction of SL becomes negligible, but the adsorption amount increases, indicating that the electrostatic interaction is not the main driving force of SL/PDAC self-assembly. For adsorption of SL in saline solution onto the PDAC surface, the cation-π interaction is the main driving force, and the hydrophobic interaction plays an important role in the adsorbed amount.

Advances in epitope molecularly imprinted polymers for protein detection: a review.

Epitope molecularly imprinted polymers (EMIPs) are novel imprinted materials using short characteristic peptides as templates rather than entire proteins. To be specific, the amino acid sequence of the template peptide is the same as an exposed N- or C-terminus of a target protein, or its amino acid composition and sequence replicate a similar conformational arrangement as the same amino acid residues on the surface of the target protein. EMIPs have a good application prospect in protein research. Herein, we focus on classification of epitope imprinting techniques, methods of epitope immobilization on matrix materials including boronate affinity immobilization, covalent bonding immobilization, physical adsorption immobilization and metal ion chelation immobilization, and application of EMIPs in peptides, proteins, target imaging and target therapy fields. Finally, the main problems and future development are summarized.

Rheological investigation of a versatile salecan/curdlan gel matrix.

Hydrogel, as a three-dimensional material with high water content, has unique physicochemical and variable mechanical properties. Natural polysaccharide-based composite hydrogels are very popular within medical industry as these viscoelastic materials are non-toxic, biodegradable, bioabsorbable, and biocompatible. This research investigates the engineering of novel composite hydrogels from natural polysaccharides salecan and curdlan without any structural modification and chemical crosslinking. The scanning electron microscopy, Fourier transform infrared spectroscopy and various rheological methods were employed to investigate the morphology, molecular interaction, and flow behavior of the samples respectively. The key rheological parameters were compared using the Power Law, Herschel-Bulkley and Arrhenius models. This is the first study reporting a novel composite hydrogel made from Salecan and Curdlan with ideal elasticity, enhanced thermostability, good injectability, self-recovery and other rheological properties that will pave the way for application in different fields.

Interactions of microplastics and antibiotic resistance genes and their effects on the aquaculture environments.

Microplastics (MPs) and antibiotic resistance genes (ARGs) have become the increasing attention and global research hotpots due to their unique ecological and environmental effects. As susceptible locations for MPs and ARGs, aquaculture environments play an important role in their enrichment and transformation. In this review, we focused on the MPs, ARGs, and the effects of their interactions on the aquaculture environments. The facts that antibiotics have been widely applied in different kinds of agricultural productions (e.g., aquaculture) and that most of antibiotics enter the water environment with rainfall and residual in the aquaculture environment have been resulting in the emergence of antibiotic resistance bacteria (ARB). Moreover, the water MPs are effective carriers of the environmental microbes and ARB, making them likely to be continuously imported into the aquaculture environments. As a result, the formation of the compound pollutions may also enter the aquatic organisms through the food chains and eventually enter the human body after a long-term enrichment. Furthermore, the compound pollutions result in the joint toxic effects on the human health and the ecological environment. In summary, this review aims to emphasize the ecological effects and the potential hazards on the aquaculture environments where interactions between MPs and ARGs results, and calls for to reduce the use of the plastic products and the antibiotics in the aquaculture environments.

The Identification and Genetic Characterization of Parechovirus Infection Among Pediatric Patients With Wide Clinical Spectrum in Chongqing, China.

Human parechoviruses (HPeVs) are important causes of infection in children. However, without a comprehensive and persistent surveillance, the epidemiology and clinical features of HPeV infection remain ambiguous. We performed a hospital-based surveillance study among three groups of pediatric patients with acute respiratory infection (Group 1), acute diarrhea (Group 2), and hand, foot and mouth disease (Group 3) in Chongqing, China, from 2009 to 2015. Among 10,212 tested patients, 707 (6.92%) were positive for HPeV, with the positive rates differing significantly among three groups (Group 1, 3.43%; Group 2, 14.94%; Group 3, 3.55%; P < 0.001). The co-infection with other pathogens was detected in 75.2% (531/707) of HPeV-positive patients. Significant negative interaction between HPeV and Parainfluenza virus (PIV) (P = 0.046, OR = 0.59, 95% CI = 0.34-0.98) and positive interactions between HPeV and Enterovirus (EV) (P = 0.015, OR = 2.28, 95% CI = 1.23-4.73) were identified. Among 707 HPeV-positive patients, 592 (83.73%) were successfully sequenced, and 10 genotypes were identified, with HPeV1 (n = 396), HPeV4 (n = 86), and HPeV3 (n = 46) as the most frequently seen. The proportion of genotypes differed among three groups (P < 0.001), with HPeV1 and HPeV4 overrepresented in Group 2 and HPeV6 overrepresented in Group 3. The spatial patterns of HPeV genotypes disclosed more close clustering of the currently sequenced strains than those from other countries/regions, although they were indeed mixed. Three main genotypes (HPeV1, HPeV3, and HPeV4) had shown distinct seasonal peaks, highlighting a bi-annual cycle of all HpeV and two genotypes (HPeV 1 and HPeV 4) with peaks in odd-numbered years and with peaks in even-numbered years HPeV3. Significantly higher HPeV1 viral loads were associated with severe diarrhea in Group 2 (P = 0.044), while associated with HPeV single infection than HPeV-EV coinfection among HFMD patients (P = 0.001). It's concluded that HPeV infection was correlated with wide clinical spectrum in pediatric patients with a high variety of genotypes determined. Still no clinical significance can be confirmed, which warranted more molecular surveillance in the future.

Genipin cross-linked carbon dots for antimicrobial, bioimaging and bacterial discrimination.

Multifunctional carbon dots (CDs) present enormous potential in numerous applications and have attracted widespread attention for various applications in the biomedical field. Bacterial infection is a common health issue; the development of antibacterial materials with low toxicity and good biocompatibility is becoming more important. In this work, we synthesized a new type of nitrogen co-doped carbon dots-genipin covalent conjugate (N-CDs-GP) via hydrothermal methods. The microstructure and chemical composition of the N-CDs-GP were characterized. The biocompatibility, stability, antibacterial activity, and fluorescence performance of the N-CDs-GP were assessed. The results revealed that N-CDs-GP possessed high biocompatibility, high light stability, and broad antibacterial activity. Additionally, selective Gram-positive bacterial imaging by N-CDs-GP provided a more rapid method of bacterial detection. The N-CDs-GP have the potential to be applied as bioimaging and antibacterial agents and for bacterial discrimination.

Three-dimensional CdS nanosheet-enwrapped carbon fiber framework: Towards split-type CuO-mediated photoelectrochemical immunoassay.

This work reports a customized methodology for the fabrication of 3D CdS nanosheet (NS)-enwrapped carbon fiber framework (CFF) and its utilization for sensitive split-type CuO-mediated PEC immunoassay. Specifically, the 3D CdS NS-CFF was fabricated via a solvothermal process, while the sandwich immunocomplexing was allowed in a 96 well plate with CuO nanoparticles (NPs) as the signaling labels. The subsequent release of the Cu2+ ions was directed to interact with the CdS NS, generating trapping sites and thus inhibiting its photocurrent generation. In such a protocol, the 3D CdS NS-CFF photoelectrode could not only guarantee its sufficient contact with the Cu2+-containing solution but also supply plenty CdS surface for the Cu2+ ions. Because of the target-dependent release of the Cu2+ ions and its proper coupling with the 3D CdS NS-CFF photoelectrode, a sensitive split-type PEC immunoassay was achieved for the detection of brain natriuretic peptide (BNP). This proposed system exhibited good stability and selectivity, and its applicability for real sample analysis was also demonstrated via comparison with the commercial BNP enzyme-linked immunosorbent assay (ELISA) kit. We expect this work could stimulate more interest in the design and utilization of 3D photoelectrodes for novel PEC bioanalysis.

The physical microenvironment of hematopoietic stem cells and its emerging roles in engineering applications.

Stem cells are considered the fundamental underpinnings of tissue biology. The stem cell microenvironment provides factors and elements that play significant roles in controlling the cell fate direction. The bone marrow is an important environment for functional hematopoietic stem cells in adults. Remarkable progress has been achieved in the area of hematopoietic stem cell fate modulation based on the recognition of biochemical factors provided by bone marrow niches. In this review, we focus on emerging evidence that hematopoietic stem cell fate is altered in response to a variety of microenvironmental physical cues, such as geometric properties, matrix stiffness, and mechanical forces. Based on knowledge of these biophysical cues, recent developments in harnessing hematopoietic stem cell niches ex vivo are also discussed. A comprehensive understanding of cell microenvironments helps provide mechanistic insights into pathophysiological mechanisms and underlies biomaterial-based hematopoietic stem cell engineering.

A sensitive amperometric AChE-biosensor for organophosphate pesticides detection based on conjugated polymer and Ag-rGO-NH2 nanocomposite.

Long-term accumulation of organophosphate pesticides in environment presents a potential hazard to human and animal health. Towards this, a highly sensitive amperometric AChE-biosensor based on conjugated polymer and Ag-rGO-NH2 nanocomposite has been successfully developed. First, 4, 7-di (furan-2-yl) benzo thiadiazole (FBThF) was electrochemically polymerized on the electrode surface. Then, Ag-rGO-NH2 nanocomposite and acetylcholinesterase (AChE) are modified on the polymer membrane surface. In this way, a novel amperometric AChE-biosensor was successfully prepared. The as-prepared biosensor possessed excellent conductivity, catalytic activity, and biocompatibility which were attributed to the synergistic effects of poly(FBThF) and Ag-rGO-NH2 and provided a hydrophilic surface for AChE adhesion. Under optimized conductions, the linear range was 0.099-9.9 µg L-1 with a regression coefficient of 0.9947 for malathion, 0.0206-2.06 µg L-1 with a regression coefficient of 0.9969 for trichlorfon. The detection limit is calculated to be about 0.032 µg L-1 for malathion and 0.001 µg L-1 for trichlorfon (S/N = 3). Moreover, the biosensor exhibited acceptable reproducibility and long-term stability, which makes it possible to provide a novel and promising tool for analysis of organophosphate pesticides.

Bioinspired enamel-like oriented minerals on general surfaces: towards improved mechanical properties.

As the hardest tissue in human body, enamel has attracted significant research interest in recent years. It has been acknowledged that the highly oriented arrangement of hydroxyapatite (HAp) crystallites of the enamel plays a crucial role owing to its excellent mechanical properties. So far, the preparation of enamel-like HAp crystallites on general substrates using mild conditions remains a challenge. Here, inspired by natural enamel, we developed a biomimetic, anodic alumina oxide (AAO)-assisted, double-layered gel system to fabricate well-oriented HAp crystals on universal surfaces. The one-directional ion flow was elaborately modulated for mineralization based on the synergistic effect of the double-layered gel and the AAO membrane, leading to highly oriented HAp crystallites. In addition, the introduction of polydopamine as a nucleating agent makes this method applicable for a wide range of substrates. The as-prepared minerals show a well-aligned enamel-like structure, exhibiting an elastic modulus of 52 GPa and nanohardness of 0.73 GPa, which are close to those of natural enamel. We envision that the strategy has potential applications for tooth repair and will provide guidelines for the mineralization of other inorganic minerals.