In this article, TiO
2
-modified ZnO nanotube arrays (NTAs) are successfully synthesized and used to prepare a nonenzymatic biosensor for the detection of glucose and hydrazine hydrate. In brief, the ...ZnO@TiO
2
NTAs are synthesized on zinc foil by two steps of simple hydrothermal method. Therefore, it can be directly used as a working electrode and is not needed to be modified to other electrode surface by any means to form a sensor. In the oxidation of glucose and reduction reaction of hydrazine hydrate, it exhibits excellent electrocatalytic performance. Moreover, it has high sensitivity, a fast response time (less than 3 s), and a detection limit as low as 0.5 μM (S/N = 3) toward glucose and hydrazine hydrate respectively. In the selectivity of the target analyte, the Zn–ZnO@TiO
2
nanocomposite electrode can effectively resist the influence of different interferent, including uric acid, dopamine, and
l
-cysteine.
Aims: The balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) is involved in the morphogenesis of normal salivary gland as well as in the mechanisms of tumour ...invasion and metastasis. The role of MMPs and TIMPs in pleomorphic adenoma has not been elucidated sufficiently. Our aim was to analyse the mRNA and protein expression of MMP‐2, MMP‐9, TIMP‐1 and TIMP‐2 in the epithelium and stroma of pleomorphic adenoma and to evaluate their roles.
Methods and results: In each sample from six patients, cells from the epithelium and stroma were obtained by laser microdissection. The mRNA expression of MMPs and TIMPs was determined by real‐time quantitative reverse transcriptase‐polymerase chain reaction and protein expression was confirmed by immunohistochemistry. Results showed that mRNA expression of MMPs and TIMPs was significantly higher in stroma than in epithelium in most patients. MMPs and TIMPs were immunoreactive mainly in epithelium rather than in stroma.
Conclusions: Our results provide preliminary evidence that stromal myoepithelium may be the primary source of MMPs and that the stroma has the potential to play a more important role than ductal epithelium in biological behaviour of pleomorphic adenomas. These findings seem worthy of further investigation.
Metabolomics, the exponentially developing technique, could provide a systemic mapping in toxicology by directly measuring small molecular metabolites. 2,3,7,8-Tetrachlorodibenzo-
p-dioxin (TCDD) was ...found to be neurotoxic in mammalian animals. In this study, we employed liquid chromatography/quadrupole time-of-flight mass spectrometry for non-targeted analysis of metabolic profiling in hippocampal sample sets of the rats exposed to TCDD. Hippocampal metabolome from different ages of the healthy rats (4-week, 12-week and 20-week) was also deciphered. The relationship between the two tested cases was unlocked to delineate TCDD toxicity associated with ageing. Tandem mass spectrometry fragmentation in conjunction with metabolic database searching and compared to authentic standards was utilized for metabolite identification. As a consequence, the reduced levels of phenylalanine and leucine/isoleucine as well as the up-regulation of inosine and hypoxanthine were highlighted for understanding of TCDD toxicity related to age in rats and the trajectory was depicted by principal components analysis.
Cas12a (also known as “Cpf1”) is a class 2 type V-A CRISPR-associated nuclease that can cleave double-stranded DNA at specific sites. The Cas12a effector enzyme comprises a single protein and a ...CRISPR-encoded small RNA (crRNA) and has been used for genome editing and manipulation. Work reported here examined in vitro interactions between the Cas12a effector enzyme and DNA duplexes with varying states of base-pairing between the two strands. The data revealed that in the absence of complementarity between the crRNA guide and the DNA target-strand, Cas12a binds duplexes with unpaired segments. These off-target duplexes were bound at the Cas12a site responsible for RNA-guided double-stranded DNA binding but were not cleaved due to the lack of RNA/DNA hybrid formation. Such promiscuous binding was attributed to increased DNA flexibility induced by the unpaired segment present next to the protospacer-adjacent-motif. The results suggest that target discrimination of Cas12a can be influenced by flexibility of the DNA. As such, in addition to the linear sequence, flexibility and other physical properties of the DNA should be considered in Cas12a-based genome engineering applications.
PbTiO3 nanorods with tetragonal phase were synthesized by hydrothermal method and heat treatment, and temperature-dependent electrical transport properties of individual PbTiO3 nanorod were ...investigated. The results show that the conductivities of PbTiO3 nanorods are gradually enhanced with temperature increasing from 77.4 to 295
K, and exhibit the typical nonlinear I–V characteristics. The barrier height between Au electrode and nanorod is reduced from 0.137 to 0.088
eV with increasing bias from 0.2 to 1
V. The corresponding values of thermal activation energies are 0.172 and 0.06
eV below the conduction band for 180–295 and 77.4–180
K, respectively. This semiconductor-like behavior may result from the larger number of surface defects or localized states in the amorphorized PbTiO3.
A reference genome is important for genomic and phylogenomic analysis, but except for a brachiopod Daphnia pulex, other crustacean genomes have not been completely sequenced. As one of the most ...economically important crustaceans, decapod shrimps have attracted great attentions worldwide. But the highly complexity block us from completing shrimp genomes. To explore the decapod shrimp genomes, we performed phylogenomic and comparative genomics analyses of pancrustaceans using transcriptome data. A group of 85 single-copy genes were collected from two shrimps and seven genome-available arthropods for phylogenetic analysis. It was found that the two major members of Pancrustacea, Hexapoda and Crustacea, fall into respective monophyletic clades. D. pulex and shrimps were estimated divergent at about 395 Myr and the gene family compositions were significantly different between them. The gene families involved in ion binding, peroxidase activity and cytoskeletal part were significantly expanded in shrimps, which were considered tightly associated with the seawater environment adaptation. When comparing the two shrimps, gene families involved in synapse in Litopenaeus vannamei and cellular component in Penaeus monodon showed significant expansion, which implies the nervous system of L. vannamei and cellular structure of P. monodon might be adaptively evolved respectively.
•Branchiopods are phylogenetic close to shrimps rather than hexapods.•Gene family compositions are significantly biased between shrimps and Branchiopods.•The expanded gene families in shrimps associated with the environment adaptation.•Nervous system and cellular structure of two shrimps maybe adaptively evolved.
Polyploids account for approximately 70% of flowering plants, including many field, horticulture and forage crops. Cottons are a world-leading fiber and important oilseed crop, and a model species ...for study of plant polyploidization, cellulose biosynthesis and cell wall biogenesis. This study has addressed the concerns of physical mapping of polyploids with BACs and/or BIBACs by constructing a physical map of the tetraploid cotton, Gossypium hirsutum L. The physical map consists of 3,450 BIBAC contigs with an N50 contig size of 863 kb, collectively spanning 2,244 Mb. We sorted the map contigs according to their origin of subgenome, showing that we assembled physical maps for the A- and D-subgenomes of the tetraploid cotton, separately. We also identified the BIBACs in the map minimal tilling path, which consists of 15,277 clones. Moreover, we have marked the physical map with nearly 10,000 BIBAC ends (BESs), making one BES in approximately 250 kb. This physical map provides a line of evidence and a strategy for physical mapping of polyploids, and a platform for advanced research of the tetraploid cotton genome, particularly fine mapping and cloning the cotton agronomic genes and QTLs, and sequencing and assembling the cotton genome using the modern next-generation sequencing technology.
Lithium-ion batteries (LIBs) technology have been widely utilized as these batteries show great promise as power sources in our life. However, the commercial anode is mainly carbon materials which ...facing safety issues owing to a low Li-intercalation potential. The spinel Li4Ti5O12 (LTO) has attracted special attention for its structural changes lightly, better safety performance and stable cycle reversibility. Herein, we increased the electronic conductivity of LTO via improving the transport properties of the material with sucrose as carbon sources. The modified LTO with sucrose were successfully fabricated and found to exhibit better electronic conductivity. XRD results showed that all the major diffractions from the spinel structure of LTO can be found in the modified LTO such as (1 1 1), (3 1 1), (4 0 0) but there are no observations of the carbon diffraction peaks. Electrochemical impedance spectroscopy (EIS) data shows modified LTO resistance was nearly one third of the standard LTO value, which indicates modifying LTO with sucrose is a promising approach to prepare the high performance LTO anode.
Voice production occurs through vocal cord and vibration coupled to glottal airflow. Vocal cord lesions affect the vocal system and lead to voice disorders. In this paper, a pathological voice source ...analysis system is designed. This study integrates nonlinear dynamics with an optimized asymmetric two-mass model to explore nonlinear characteristics of vocal cord vibration, and changes in acoustic parameters, such as fundamental frequency, caused by distinct subglottal pressure and varying degrees of vocal cord paralysis are analyzed. Various samples of sustained vowel /a/ of normal and pathological voices were extracted from MEEI (Massachusetts Eye and Ear Infirmary) database. A fitting procedure combining genetic particle swarm optimization and a quasi-Newton method was developed to optimize the biomechanical model parameters and match the targeted voice source. Experimental results validate the applicability of the proposed model to reproduce vocal cord vibration with high accuracy, and show that paralyzed vocal cord increases the model coupling stiffness.
Purpose: To investigate the effect of combined use of composite skin grafting and recombinant human basic fibroblast growth factor (rh-bFGF) on plastic surgery for extensive burn scars, and its ...influence on wound healing and inflammatory responses in patients.
Methods: Hospital records of 120 patients who underwent extensive scar plastic surgery after burns in Hanchuan People’s Hospital from February 2019 to February 2020 were retrospectively analyzed. The patients were equally assigned to study group (STG) and control group (COG), based on the order of admission. All patients received composite skin grafting surgery and post-surgery topical silver sulphadiazine cream regularly, while those in study group (STG) received additional treatment with rh-bFGF spray on the wound surfaces. Scar scores, degree of wound healing, populations of fibrocytes and capillaries, levels of vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1), and activities of lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) were evaluated.
Results: Patients in STG had significantly better scar scores, shorter mean wound healing time, higher mean degree of wound healing, higher scores on inflammatory reactions near the wounds, and higher populations of fibrocytes and capillaries, when compared with patients in COG group (p < 0.001). After surgery, there were lower levels of VEGF and TGF-β1, and lower levels of activities of LDH and SDH in STG than in COG group (p < 0.001).
Conclusion: Rh-bFGF accelerates the proliferation of wound tissue, improves local microcirculation, regulates inflammatory response, and enhances wound healing in burn scar patients when used in combination with composite skin grafting. Therefore, Rh-bFGF has a potential for enhanced management of burn scars.
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