RESUMO
The in-situ leaching of rare earth minerals results in ecological differences between sunlit and shady slopes, which may be related to differences in the distribution REEs in the associated soil matrices. Studies of REEs mine tailings in Southern China indicated higher total concentrations of REEs on sunlit slopes compared to shady ones. Specifically, the exchangeable REEs fraction (F1-REEs) was higher on the shady slopes, whereas the Fe/Mn oxides bound REEs fraction (F3-REEs) was higher on the sunlit slopes. In addition, light REE (LREE) concentrations were lower at lower elevations. With the exception of the Ce fraction which remained stable, this indicated a change in all REEs distributions, moving from F1-REEs towards the residual fraction. Hierarchical cluster and principal component analysis revealed a strong correlation between F3-REEs, organic matter bound REEs (F4-REEs), and LREEs, and a positive association of F3-REEs with sunlight exposure. Partial Least Squares Path Modeling analysis suggested that OM promoted the conversion of LREEs to F3 and F4-REEs in soil driven by sunlight exposure. Additionally, as the Feo/Fed ratio decreased, more LREEs were converted to F3. This study suggests that sunlight and elevation both play a critical role in the geochemical dynamics of REEs in in-situ tailings, advocating for environmental evaluations to be undertaken in order to accurately understand the ecological impacts of rare earth mining.
RESUMO
In the current study, an electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS) were employed to investigate the volatile flavor compounds (VFCs) of intense flavor beef tallow (L) and ordinary beef tallow (P). The study results indicate that an E-nose combined with an LDA and GC-IMS combined with an OPLS-DA can effectively distinguish between the two types of beef tallow. Compared with ordinary beef tallow, the E-nose sensors of intense flavor beef tallow have stronger response signals to sulfides, terpenes, and nitrogen oxides. A total of 22 compounds contribute to making the flavor of intense flavor beef tallow more typical and richer; in contrast, ethyl acetate was the main aroma-active compound found in the ordinary beef tallow. Sulfur-containing compounds and terpenoids might be the key substances that cause sensory flavor differences between the two types of beef tallow. In conclusion, the results of this study clarify the characteristics and differences of the two types of beef tallow and provide an enhanced understanding of the differences in the flavors of the two types of beef tallow.
RESUMO
Carbon sources and their utilization are vital for fungal growth and development. C4-dicarboxylic acids are important carbon and energy sources that function as intermediate products of the tricarboxylic acid cycle. Transport and regulation of C4-dicarboxylic acid uptake are mainly dependent on tetracarboxylic acid transporters (Dcts) in many microbes, although the roles of Dct genes in fungi have only been partially characterized. Here, we report on the functions of two Dct genes (Dct1 and Dct2) in the entomopathogenic fungus Metarhizium acridum. Our data showed that loss of the MaDct1 gene affected utilization of tetracarboxylic acids and other carbon sources. ΔMaDct1 mutants showed larger colony sizes with extensive mycelial growth but were delayed in conidiation with decreased conidia yield as compared to the wild-type parental strain. On the nutrient-deficient medium, SYA, the wild-type strain produced microcycle conidia, whereas the ΔMaDct1 mutant produced (normal) aerial conidia. In addition, ΔMaDct1 had decreased tolerance to cell wall perturbing agents, but increased tolerances to UV-B radiation and osmotic stress. Insect bioassays indicated that loss of MaDct1 did not affect pathogenicity. In contrast, no distinct phenotypic change was observed for the MaDct2 mutant in terms of growth and biocontrol characteristics. Transcriptomic profiling between wild type and ΔMaDct1 showed that differentially expressed genes were enriched in carbohydrate and amino acid metabolism, transport and catabolism, and signal transduction. These results demonstrate that MaDct1 regulates the conidiation pattern shift and mycelial growth by affecting utilization of carbon sources. These findings are helpful for better understanding the effect of intermediates of carbon metabolism on fungal growth and conidiation. KEY POINTS: ⢠MaDct1 influences fungal growth and conidiation by affecting carbon source utilization. ⢠MaDct1 regulates conidiation pattern shift under nutrient deficiency condition. ⢠MaDct1 is involved in stress tolerance and has no effect on virulence. ⢠MaDct2 has no effect on growth and biocontrol characteristic.
Assuntos
Regulação Fúngica da Expressão Gênica , Metarhizium , Perfilação da Expressão Gênica , Virulência , Proteínas de Membrana Transportadoras/metabolismo , Esporos Fúngicos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMO
Background: With the extensive application and continuous expansion of the Internet of Things (IoT), the access of a large number of resource-limited nodes makes the IoT application face a variety of security vulnerabilities and efficiency limitations, and the operating efficiency and security of IoT are greatly challenged. Key management is the core element of network security and one of the most challenging security problems faced by wireless sensor networks. A suitable key management scheme can effectively defend against network security threats. However, among the key management schemes that have been proposed so far, most of them do not take into account the efficiency in terms of connectivity rate and resource overhead, and some of them even have security risks. Methods: In this article, based on the symmetric polynomial algorithm, a dynamic coefficient symmetric polynomial key management scheme is proposed to better solve the IoT security problem. In this scheme, the nodes' IDs are mapped into the elements of the shared matrix M by the identity mapping algorithm, and these elements are used to construct polynomials P(x,y) to generate pairwise keys. The communicating nodes have their own coefficients of P(x,y) and thus have higher connectivity. Results: The overall performance evaluation shows that the scheme significantly improves the resilience against node capture and effectively reduces the communication and storage overheads compared to the previous schemes. Moreover, the scheme overcomes the λ-security of symmetric polynomial key management scheme, and is able to provide a large pool of polynomials for wireless sensor networks, facilitating large-scale application of nodes.
RESUMO
This study aimed to noninvasively assess the relationship between the labial gingival thickness (GT) and the underlying bone thickness (BT) of maxillary anterior teeth by two digital techniques. A total of 30 periodontally healthy participants with 172 maxillary anterior teeth were enrolled. GT and BT were measured at 2, 4 and 6 mm apical to the cemento-enamel junction (CEJ) by two digital techniques: M1-cone-beam computed tomography (CBCT) and M2-digital intraoral scanning (DIS) combined with CBCT. The Pearson's correlation coefficient was calculated to determine the correlation between GT and BT. A significant negative correlation was identified between GT and BT at 2 mm apical to the CEJ for central incisors (CI), lateral incisors (LI), and canines (CA) both by M1 and M2, while a weak negative correlation at 4 mm apical to the CEJ was observed by M1 for CA. No significant correlation was found at other sites by both M1 and M2. The labial BT was < 1 mm in most cases (85% of CI; 97% of LI; and 90% of CA). Within the limitation of this study, it was concluded that GT and BT seemed to be negatively correlated at 2 mm apical to the CEJ. Therefore, caution is warranted when implant restoration at the esthetic area of the anterior teeth.
Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Gengiva/diagnóstico por imagem , Imageamento Tridimensional/métodos , Maxila/diagnóstico por imagem , Dente/diagnóstico por imagem , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto JovemRESUMO
OBJECTIVE: This study aimed to compare the changes in sagittal parameters and the efficacy of pedicle subtraction osteotomy (PSO) in patients with ankylosing spondylitis (AS) and kyphosis under different lumbar sagittal morphologies and to explore the effect of sagittal morphology on the selection of PSO levels. METHODS: A total of 24 patients with AS and thoracolumbar kyphosis (TK) who were admitted to the First Affiliated Hospital of Xinjiang Medical University between 2008 and 2019 were enrolled in this study. They were divided into two groups: a lumbar lordosis group (n = 14) and a lumbar kyphosis group (n = 10). Changes in sagittal parameters, lumbar Japanese Orthopaedic Association (JOA) scores, and visual analog scale (VAS) scores for lumbar pain before and after operation were compared between the two groups to evaluate postoperative efficacy. RESULTS: The preoperative lumbar lordosis (LL) was -29.29 ± 5.40 (lordosis) and 13.50 ± 3.65 (kyphosis) (P < 0.01), and the preoperative sagittal vertical axis (SVA) was 171.35 ± 25.46 (lordosis) and 223.58 ± 21.87 (kyphosis) (P < 0.01). Preoperative global kyphosis (GK) was 75.71 ± 5.26 (lordosis) and 86.30 ± 10.32 (kyphosis) (P < 0.05). All patients in the lordosis group underwent PSO surgery at the twelfth thoracic vertebra (T12) or the first lumbar spinal vertebra (L1), while all patients in the kyphosis group underwent the surgery at the second or third lumbar spinal vertebra (L2 or L3). The differences in postoperative GK, LL, and SVA between the two groups were not significant (P > 0.05). The JOA scores of the two groups increased from 13.00 ± 0.83 (lordosis) and 11.30 ± 0.93 (kyphosis) before surgery to 21.00 ± 0.67 and 19.70 ± 0.60 after surgery (P < 0.05). CONCLUSION: Preoperative lumbar sagittal morphology needs to be considered when selecting the optimal osteotomy plane. An osteotomy can achieve the greatest success in patients with lumbar kyphosis at L2/L3; for patients with lumbar lordosis, it can achieve satisfactory outcomes at T12/L1.
RESUMO
BACKGROUND: Anticholinergic administration prior to flexible bronchoscopy has been investigated, but studies have not yielded consistent results. METHODS: Patients were randomized 1:1 to receive nebulized 4âml ipratropium bromide (1âmg, nâ=â125) or placebo (nâ=â125) for 15âminutes as premedication, 20 to 40âminutes before bronchoscopy. Airway secretions, bleeding, patient discomfort, procedure time, and procedure-related adverse events were compared between the groups. RESULTS: Nebulized ipratropium bromide prior to bronchoscopy could reduce airway secretions and patient discomfort (Pâ=â.02; Pâ<â.001, respectively), but not tracheobronchial bleeding or procedure time (Pâ=â.51, Pâ=â.36, respectively). Chest nodule or mass was the most common indication for performing bronchoscopy. The adverse events were higher in ipratropium bromide group, and hypertension was the most common complication. CONCLUSION: Nebulized ipratropium bromide prior to bronchoscopy is a more effective regimen that shows a practical benefit on the airway secretions and patient comfort, though these effects may not translate into any marked reduction in bleeding or of procedure time under general anesthesia. We suggest that routine nebulized ipratropium bromide premedication for bronchoscopy could be useful and beneficial. TRIAL REGISTRATION: chictr.org.cn: ChiCTR1800016881.
Assuntos
Secreções Corporais/efeitos dos fármacos , Brônquios/efeitos dos fármacos , Broncodilatadores/administração & dosagem , Broncoscopia , Ipratrópio/administração & dosagem , Traqueia/efeitos dos fármacos , Administração por Inalação , Brônquios/fisiologia , Broncodilatadores/farmacologia , Método Duplo-Cego , Feminino , Humanos , Ipratrópio/farmacologia , Masculino , Pessoa de Meia-Idade , Nebulizadores e Vaporizadores , Pré-Medicação , Traqueia/fisiologiaRESUMO
In this study, coal powder was used as the adsorbent for quinoline. The effect of inorganic salt ions on the adsorption was explored, and the results suggest that the addition of inorganic salt ions can enhance both the removal rate and the amount of quinoline adsorbed. The removal rate and adsorbed amount of quinoline were 83.87% and 1.26 mg/g without inorganic salt ions. Under the same adsorption conditions, the removal rate and adsorbed amount of quinoline could reach 90.21% and 1.35 mg/g when Na+ was present in the solution, and 94.47% and 1.42 mg/g with the presence of Ca2+. In addition, the adsorption of quinoline using coal fitted the Freundlich isothermal adsorption model. Changes in the Gibbs free energy, entropy and heat of adsorption were all negative, indicating that the adsorption was spontaneous and exothermic. The changes in the absolute value of Gibbs free energy under both Na+ and Ca2+ were higher than that in the blank(without inorganic salt ions). The pseudo-second-order kinetic model was found to fit the adsorption kinetic data well, and the activation energy of adsorption under Na+ and Ca2+ were lower than that in the blank. These indicate that the addition of inorganic salt ions was beneficial to the adsorption process.
Assuntos
Carvão Mineral , Quinolinas , Termodinâmica , Adsorção , Íons , Cinética , Poluentes Químicos da Água , Purificação da ÁguaRESUMO
The objective of the present paper is to study the influence of water stress on wheat spectrum red edge parameters by using field wheat spectrum data obtained from water stress experiment. Firstly, the authors analyzed the influence of water stress on wheat spectrum reflectance. Then the authors got the wheat red edge position and red edge peak through calculating wheat spectrum first-order differential and analyzed the influence of water stress on wheat red edge parameters. Finally the authors discussed the relationship between red peak and wheat yield. The results showed that the wheat red edge position shows "red shift" at the beginning of the wheat growth period and "blue shift" at the later period of the wheat growth period under the water stress experiment. Also, the red edge peak of the wheat showed that red edge peak increased with the water stress sharpening at the beginning of the wheat growth period, and then the red edge peak reduced with the water stress sharpening. The wheat red edge peak presented positive correlation with the wheat yield before the elongation period, and exhibited negative correlation after that period.