Combining surface-enhanced Raman spectroscopy (SERS) of aggregated graphene oxide/gold nanoparticle hybrids with immunomagnetic bead sample preparation method, a highly sensitive strategy to ...determine the clenbuterol content in animal urine was developed. Based on a linear calibration curve of the SERS characteristic peak intensity of clenbuterol at Δv = 1474 cm(-1) versus the spiked clenbuterol concentration in the range of 0.5-20 ng·mL(-1), the quantity of clenbuterol in real animal urine samples can be determined and matches well with those determined by LC-MS/MS, while the detection time is significantly reduced to 15 min/sample. The limits of detection and quantification in the urine are 0.5 ng·mL(-1) and 1 ng·mL(-1), respectively, and the recovery clenbuterol rates are 82.8-92.4% with coefficients of variation <9.4%. The day-to-day variation of the detection is less than 6.41%, and the shelving life of the SERS substrates is no less than 4 weeks. All these indicate that this proposed SERS detection protocol for clenbuterol is reproducible, reliable, and can be easily developed for the routine monitoring of the illicit use of clenbuterol in animal farming.
A comprehensive theory is developed for the chiral optical response of two configurations of the N-oscillator Born-Kuhn model (NOBK): the helically stacked and the corner stacked models. In the ...helical NOBK model, there is always a chiral response regardless of the value of
, whereas in the corner NOBK, only configurations with even
demonstrate a chiral response. Generally, the magnitudes of optical rotatory dispersion (ORD) and circular dichroism (CD) increase with
when the parameters of each oscillator are fixed. In cases of weak coupling, the spectral shapes of ORD and CD remain invariant, while strong coupling significantly alters the spectral shapes. For large damping, the spectral amplitude becomes smaller, and the spectral features become broader. In the presence of small damping, strong coupling introduces degeneracy in the coupled oscillator system, leading to multiple spectral features in both ORD and CD across the entire spectral region. This simple model can not only help in the design of tunable chiral metamaterials but also enhance our understanding of chiro-optical responses in structures with different configurations.
Biodegradable polymers have been rapidly developed for alleviating excessive consumption of non-degradable plastics. Additive manufacturing is also a green energy-efficiency and ...environment-protection technique to fabricate complicated structures. Herein, biodegradable polyesters, polyglycolic acid (PGA) and poly (butyleneadipate-co-terephthalate) (PBAT) were blended and developed into feedstock for 3D printing. Under a set of formulations, PGA/PBAT blends exhibited a tailored stiffness-toughness mechanical performance. Then, PGA/PBAT (85/15 in weight ratio) with good thermal stability and mechanical property were extruded into filaments with a uniform wire diameter. Mechanical testing clearly indicated that FDM 3D-printed exhibited comparable tensile, flexural and impact properties with injection-molded samples of PGA/PBAT (85/15). Furthermore, uniform and graded Diamond-Triply Periodic Minimal Surfaces (D-TPMS) structures were designed and successfully manufactured via the fused deposition modeling (FDM) technique. Computer tomography (CT) was employed to confirm the internal three-dimensional structures. The compressive test results showed that PGA/PBAT (85/15) D-surface structures bear better load-carrying capacity than that of neat PGA, giving an advantage of energy absorption. Additionally, typical industrial parts were manufactured with excellent dimension-stability, no-wrapping and fine quality. Collectively, biodegradable PGA/PBAT material with good printability has great potentials in application requiring stiffer structures.
The free standing aluminum nanorods were grown on electrode and evaluated electrochemically as the anodes in the half-cell of Li-ion battery. The average diameter and length of the nanorods are 80
nm ...and 200
nm, respectively. The aligned nanorods demonstrated high capacity of 1243
mAh
g
−1 at rate of 0.5
C. A gradual decrease of the initial capacity was observed. The characterization of the anodes shows that the changes of the crystalline structure and morphology during cycling may be responsible for the capacity decay. The appropriate selection of the substrate can overcome the problems and lead the sustainable high capacity.
Abstract
Background
Anaerobic fungi are effective fibre-degrading microorganisms in the digestive tract of horses. However, our understanding of their diversity and community structure is limited, ...especially in different parts of the gastrointestinal tract.
Results
For the first time, high-throughput sequencing technology was used to analyse and predict fungal microbial diversity in different parts of the gastrointestinal tract of Mongolian horses. The results revealed that the richness and diversity of fungi in the hindgut of Mongolian horses were much higher than those in the foregut. The foregut was dominated by Basidiomycota and Ascomycota, whereas the hindgut was dominated by Neocallimastigomycota and Basidiomycota. At the genus level, the relative abundance of many pathogenic fungi (
Cryptococcus, Cladosporium, Alternaria
, and
Sarocladium
) in the foregut was significantly higher than that in the posterior gut, indicating that Mongolian horses have strong disease resistance. The prediction of fungal function also showed significant differences in the fungal flora between the foregut and the hindgut. The fungi in Mongolian horses’ foreguts were mainly pathologically nutritive and contained many animal and plant pathogens, particularly in the small intestine (jejunum and ileum). This indicates that the foregut may be the most important immune site in the digestive system of Mongolian horses, which explains the high disease resistance of Mongolian horses. The number of unassigned functional groups in the posterior gut was significantly higher than that in the anterior gut, indicating that the functions of fungal groups in the posterior gut have not been fully explored, and further studies are required in the future.
Conclusions
Analysis of high-throughput sequencing results revealed that the fungal composition varied greatly among different gastrointestinal tract segments in Mongolian horses, whose hindgut contains many anaerobic fungi involved in plant cellulose degradation. This provides important basic data for studying fungal diversity in the digestive system of healthy horses, which can be used for the health assessment of horses and provides clues for further research on the disease resistance and digestive capacity of horses, as well as a reference for the early diagnosis of intestinal diseases and innovative treatment methods.
Abstract Pseudomonas aeruginosa can cause major infection in immunocompromised patients, and successful antibiotic treatment of the infection relies on accurate and rapid identification of the ...infectious agents. Here, we reported a culture-free diagnostic method based on the surface-enhanced Raman spectroscopy (SERS) of pyocyanin (PCN), a major biomarker of P. aeruginosa . This platform can detect PCN as low as 5 ppb or 2.38×10 − 8 mol L − 1 in both aqueous solutions and spiked clinical sputum samples. It has also been used to dynamically monitor the excretion of PCN by P. aeruginosa during its growth. The presence of PCN has been detected by SERS in 15 clinical sputum samples, which indicates P. aeruginosa infection, with 95.6% sensitivity and 93.3% specificity. The system can advantageously process multiple specimens rapidly, overcomes the need for bacterial culture and diagnostic microbiology assays, and have widespread implications in the early detection of P. aeruginosa infection. From the Clinical Editor A surface enhanced Raman spectroscopy method optimized for the detection of P. aureginosa infections is presented in this paper. The presence of pyocyanin, a marker of this bacterium has been detected in 15 clinical sputum samples utilizing this method. A sensitivity of 95.6% and 93.3% specificity was reported, which suggests that the method may enable culture-free high throughput rapid detection of this infection.
Biofouling of membrane surfaces by the attachment of microorganisms is one of the major obstacles for ensuring the effectiveness of membrane separation processes. This work presents the construction ...of a zwitterionic PVDF membrane surface with improved resistance to biofouling. An amphiphilic copolymer of poly(vinylidene fluoride)-graft-poly(N,N-dimethylamino-2-ethylmethacrylate) (PVDF-g-PDMAEMA) was first synthesized via radical graft copolymerization and then the flat membrane was cast with immersed phase inversion. The PDMAEMA side chains tended to aggregate on the membrane surface, pore surface and internal pore channel surface, and were converted with 1,3-propane sultone (1,3-PS) to yield a zwitterionic membrane surface. A higher conversion of PDMAEMA chains and distribution of zwitterions were obtained using a longer treatment time. A biofouling assay indicated that incorporation of zwitterions suppressed the adsorption of extracellar polymer substances and the adhesion of Escherichia coli bacterial cells to the membrane surface, endowing the membrane with a high flux recovery and biofouling resistance in the filtration process.
By coating a fluorocarbon monolayer on a bundled Si nanorod array substrate, a superhydrophobic surface with contact angle ∼167° and sliding angle ∼2° is created due to the nanocarpet effect. Without ...forming the nanocarpet, we can only obtain a moderately hydrophobic surface with contact angle <151° and sliding angle >17°. Comparison between nanocarpets formed from nanorods with low and high densities confirms that the main reason for the superhydrophobicity is the formation of sharp pyramidal bundles, which effectively reduces the area of solid−liquid contact. Video recording and analysis of millimeter-sized water droplets bouncing on the solid surface are used to ascertain the superhydrophobicity, and the energy dissipation during a low speed impact is estimated to be several nanojoules.
Triply periodic minimal surfaces (TPMS) structures have been extensively promoted for mimicking the tissue scaffolds with interconnected pores and robust mechanical properties. To further optimize ...the mechanical performance, two kinds of TPMS structures including Schwarz P (P) and Gyroid (G) with uniform and different graded-thickness were designed and proposed in the current work. Biodegradable polymer composites based on poly (butyleneadipate-co-terephthalate) (PBAT) and poly (lactic acid) (PLA) were developed into fused filament fabrication (FFF) filaments. Results showed that PBAT/PLA filaments exhibited good flexibility, thermal and rheological properties and high printability. As for compressive properties, the load-bearing capacity and energy absorption (EA) of TPMS-G were superior to TPMS-P uniform structures. TPMS-G graded samples exhibited better EA capacity, whereas those of graded TPMS-P were inferior to uniform counterparts. The deformation behavior of the internal structure in graded TPMS-G and TPMS-P were examined by computed tomography (CT) scanning and reconstruction. Furthermore, tensile properties of graded and non-graded TPMS were also compared. Under tension load, results demonstrated that non-graded structure of TPMS were both stronger than the graded ones. The proposed biodegradable PBAT/PLA composite and structure design could be applied as biomedical soft scaffolds, wearable devices and resilient absorbing buffers.
Different morphological structures of hairs having properties like defense and camouflage help animals survive in the wild environment. Horse is one of the rare kinds of animals with complex hair ...phenotypes in one individual; however, knowledge of horse hair follicle is limited in literature and their molecular basis remains unclear. Therefore, the investigation of horse hair follicle morphogenesis and pigmentogenesis attracts considerable interest.
Histological studies revealed the morphology and pigment synthesis of hair follicles are different in between four different parts (mane, dorsal part, tail, and fetlock) of the bay Mongolian horse. Hair follicle size, density, and cycle are strongly associated with the activity of alkaline phosphatase (ALP). We observed a great difference in gene expression between the mane, tail, and fetlock, which had a greater different gene expression pattern compared with the dorsal part through transcriptomics. The development of the hair follicle in all four parts was related to angiogenesis, stem cells, Wnt, and IGF signaling pathways. Pigmentogenesis-related pathways were involved in their hair follicle pigment synthesis.
Hair follicle morphology and the activity of ALP differ among four body parts in bay Mongolian horse. Hair follicles of the different body parts of the are not synchronized in their cycle stages. GO terms show a regional specificity pattern between different skin parts of the bay Mongolian horse. These results provide an insight into the understanding of the biological mechanism of the hair follicle in other mammals.
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