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1.
J Colloid Interface Sci ; 606(Pt 2): 971-982, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34487944

RESUMO

Remediation of crude oil spills is a great challenge owing to the poor mobility and high viscosity of crude oil. Herein, a porous polydimethylsiloxane@wood sponge/MXene (PDMS@WSM) with outstanding compressibility and hydrophobic/lipophilic ability was demonstrated as crude oil absorbent. The surface temperature of PDMS@WSM could quickly rise to 80 °C with a working voltage of 4 V and to 66 °C under simulated sunlight irradiation of 1.5 KW m-2, respectively. Due to the excellent Joule heating and photothermal conversion effect, the PDMS@WSM displayed maximum adsorption capacity of 11.2×105 g m-3 within 6 min. The PDMS@WSM showed preferable reusability and cycle stability because of its brilliant compressibility. Moreover, the oil-collecting device based on PDMS@WSM could continuously collect crude oil spills, achieving an active collection of 25 mL crude oil within 150 s. Therefore, the porous PDMS@WSM absorbent exhibited great potential for crude oil spills remediation, energy regulation, and desalination of hypersaline water.


Assuntos
Poluição por Petróleo , Petróleo , Calefação , Poluição por Petróleo/análise , Titânio , Madeira
2.
Sci Total Environ ; 806(Pt 3): 151261, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34715222

RESUMO

The Taiwan Maternal and Infant Cohort Study (TMICS) was launched with the aim to assess the effects of prenatal exposure to phthalic acid esters (PAEs) on infant health. A total of 1102 pregnant women were enrolled in this study from 2012 to 2015. All participants completed a structured questionnaire, and provided urine specimens. The urinary concentrations of PAE metabolites in the third trimester were measured using liquid chromatography-electrospray ionization tandem mass spectrometry. Generalized additive model-penalized regression splines and logistic regression models were employed to determine the risk for low birth weight (LBW) or small for gestational age (SGA) among pregnant women exposed to PAEs. After adjustments for other covariates, each incremental unit of ln-transformed mono-n-butyl phthalate (MnBP) for pregnant women increased the odds of SGA in male neonates by 1.44 (95% CI: 0.92-2.23). An inverse association between SGA and maternal MnBP exposure level was observed in female neonates. An increase in one ln-transformed MnBP concentration unit decreased the risk of female SGA to 0.50 (95% CI: 0.24-0.97). In the penalized regression splines, increased risks of LBW/SGA in male neonates were presented while pregnant women exposed to increased MnBP levels. However, an association in the opposite direction was observed between maternal MnBP and LBW or SGA for male and female neonates. This study indicated that high maternal MnBP exposure in the third trimester was associated with LBW or SGA for male infants. Adverse effects on susceptible populations exposed to high levels of PAEs should be of concern.

3.
Cytokine ; 149: 155728, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634651

RESUMO

TNF signaling mostly supports cell growth by activating NFκB and only induces cell death when NFκB activation fails. CCN1 is a matricellular protein that has been reported capable to convert TNF from a pro-survival factor into a stimulus for cell death without interfering with NFκB signaling. In this study, we examined the relationship between CCN1 and TNF in the context of esophageal adenocarcinoma and found that CCN1 did not help TNF to induce cell death when they were together, instead, it inhibited TNF expression, as well as TNF-induced JNK activation and apoptosis. CCN1 induced apoptosis in the cancer cells by itself through upregulation of TRAIL and its death receptors. The presence of TNF significantly lowered CCN1 expression and its capability in apoptosis induction. Furthermore, we found that CCN1 boosted ADAM17-mediated cleavage of TNF receptors through ITGA11 and the soluble decoy receptors generated by this action neutralized TNF activity. Taken together, CCN1 and TNF antagonize each other in esophageal cancer cells.

4.
Sci Rep ; 11(1): 23149, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34848820

RESUMO

The present study aimed to determine whether a recently proposed cerebral small vessel disease (CSVD) classification scheme could differentiate the 5-year all-cause mortality in middle-to-old aged asymptomatic CSVD. Stroke-free and non-demented participants recruited from the community-based I-Lan Longitudinal Aging Study underwent baseline brain magnetic resonance imaging (MRI) between 2011 and 2014 and were followed-up between 2018 and 2019. The study population was classified into control (non-CSVD) and CSVD type 1-4 groups based on MRI markers. We determined the association with mortality using Cox regression models, adjusting for the age, sex, and vascular risk factors. A total of 735 participants were included. During a mean follow-up of 5.7 years, 62 (8.4%) died. There were 335 CSVD type 1 (57.9 ± 5.9 years), 249 type 2 (65.6 ± 8.1 years), 52 type 3 (67.8 ± 9.2 years), and 38 type 4 (64.3 ± 9.0 years). Among the four CSVD types, CSVD type 4 individuals had significantly higher all-cause mortality (adjusted hazard ratio = 5.0, 95% confidence interval 1.6-15.3) compared to controls. This novel MRI-based CSVD classification scheme was able to identify individuals at risk of mortality at an asymptomatic, early stage of disease and might be applied for future community-based health research and policy.

5.
Arch Insect Biochem Physiol ; : e21856, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34850449

RESUMO

The involvement of yellow genes y-b, y-c, y-e, and y-h in cuticle tanning has poorly been clarified. In the present paper, six putative yellow (y-y, y-b, y-c, y-e y-f, and y-h) genes were identified in Henosepilachna vigintioctopunctata. Hvy-b, Hvy-c, Hvy-e, and Hvy-h were abundantly transcribed at early larval and late pupal stages, especially in the epidermis. Accordingly, RNA interference (RNAi) experiments were performed by an injection of dsy-b, dsy-c, dsy-e, or dsy-h into the second instar larvae and 1-day-old pupae. The head capsule, scoli and strumae, and legs in the fourth-instar larvae became blacker; the blackish spots in the pupae were darkened and widened after RNAi of Hvy-b, compared with those of dsegfp-treated controls. Depletion of Hvy-b at the 1-day-old pupal stage expanded two pair of black markings on the sternum of the metathorax, and darkened the black patched on the sterna of the abdomen segments I-VI in the resultant adults. Depletion of Hvy-e caused darker pigmented adult body and elytral cuticles than those of dsegfp-introduced controls. However, there was no obvious difference in pigmentation of the black markings. Hvy-h-deficient larvae displayed dark yellow body color, whereas the body color of the dsegfp-injected control was pale yellow. There was no obvious difference in coloration of larval specific-black markings or pupal cuticle between dsHvy-h- and dsegfp-treated animals. Moreover, silence of Hvy-c at the second instar larval stage lightened black markings in the resulting larvae and pupae, but had no influence on pale yellow body color. Our results demonstrated their different roles of the four yellow genes during body pigmentation: HvY-b and HvY-c, respectively, inhibit and facilitate the coloration within dark markings, whereas HvY-e and HvY-h, respectively, repress the pigmentation in adult and larval body cuticles outside the black patches in H. vigintioctopunctata.

6.
Environ Pollut ; 291: 118225, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740295

RESUMO

Several transformation products (or metabolites) of neonicotinoid insecticides (NNIs) have been detected in drinking water, such as desnitro-imidacloprid and imidacloprid-urea. However, data on the occurrences of the metabolites of NNIs (mNNIs) in drinking water are mainly limited to the imidacloprid metabolites. To identify whether the potential metabolites of other widely used NNIs (such as acetamiprid, clothianidin, and thiamethoxam) occur in drinking water and to characterize their distribution profiles, twelve selected (mainly urea and desnitro/decyano) metabolites of NNIs were measured in drinking water samples (n = 884, including n = 789 for tap water, and n = 95 for shallow groundwater) that were collected from 32 provinces in mainland China and Hong Kong. Nearly 90% of the drinking water samples contained the detected mNNI residues. Among the selected mNNIs, thiamethoxam-urea (THM-urea: 76%) and decyano-acetamiprid (decyano-ACE: 73%) were frequently detected (median: 0.94 and 0.25 ng/L, respectively), which were followed by clothianidin-urea (CLO-urea: 45%), desnitro-thiamethoxam (DN-THM: 38%), and other mNNIs (detected in less than 30% of the water samples). Surface-water-sourced tap water had an approximately 8-10 times higher median cumulative concentration (ng/L) of the selected mNNIs (ΣmNNIs: 3.88) than the deep groundwater-sourced tap water (0.53) and groundwater that was directly used as drinking water (0.38). Higher ratios of THM-urea accounted for ΣTHM in north and northwest China than in south China could be partly explained by the decreasing soil pH values from north to south in China. The higher ratios of decyano-ACE accounted for ΣACE in south China than in north and northwest China could be attributable to the lower soil pH levels, higher temperatures, and greater light intensities in south China. The THM-urea, decyano-ACE, and ΣmNNIs levels in cities were found to be significantly higher than those in nonurban areas. The THM-urea levels in seven drinking water samples from Guangxi and Henan Provinces exceeded the guideline limit (100 ng/L) of the European Union. This is the first study to identify THM-urea, decyano-ACE, CLO-urea, and DN-THM in drinking water. To better assess the mass loadings of NNIs in drinking water, mNNIs should be considered in further studies.


Assuntos
Água Potável , Inseticidas , China , Água Potável/análise , Inseticidas/análise , Neonicotinoides/análise , Nitrocompostos
7.
J Hazard Mater ; : 127570, 2021 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-34753647

RESUMO

Coastal ecosystem health is of vital importance to human well-being. Field investigations of major pollutants along the whole coast of China were carried out to explore associations between coastal development activities and pollutant inputs. Measurements of target pollutants such as PFAAs and PAHs uncovered notable levels in small estuary rivers. The Yangtze River was identified to deliver the highest loads of these pollutants to the seas as a divide for the spatial distribution of pollutant compositions. Soil concentrations of the volatile and semi-volatile pollutants showed a cold-trapping effect in pace with increasing latitudinal gradient. The coastal ecosystem is facing high ecological risks from metal pollution, especially copper (Cu) and zinc (Zn), while priority pollutants of high risks vary for different kinds of protected species, and the ecological risks were influenced by both climate and physicochemical properties of environmental matrices, which should be emphasized to protect and restore coastal ecosystem functioning.

8.
Chem Sci ; 12(42): 14098-14102, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34760193

RESUMO

The SARS-CoV-2 3-chymotrypsin-like protease (3CLpro or Mpro) is a key cysteine protease for viral replication and transcription, making it an attractive target for antiviral therapies to combat the COVID-19 disease. Here, we demonstrate that bismuth drug colloidal bismuth subcitrate (CBS) is a potent inhibitor for 3CLpro in vitro and in cellulo. Rather than targeting the cysteine residue at the catalytic site, CBS binds to an allosteric site and results in dissociation of the 3CLpro dimer and proteolytic dysfunction. Our work provides direct evidence that CBS is an allosteric inhibitor of SARS-CoV-2 3CLpro.

9.
Open Med (Wars) ; 16(1): 1653-1667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34761116

RESUMO

The aim of this study was to clarify the role of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in proliferation, migration, and invasion of malignant pleural mesothelioma (MPM) cells. The quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to detect the expression of MALAT1 in MPM cell lines. The effects of MALAT1 and miR-141-3p on the proliferation, migration, and invasion of MPM cells were studied through a series of in vitro cellular experiments. The flow cytometry was utilized to detect the cell apoptosis. The dual-luciferase reporter assay was employed to explore the binding relationship among MALAT1, miR-141-3p, and YES-associated protein 1 (YAP1). MALAT1 was overexpressed in MPM cell lines, while its knockdown significantly inhibited the cell proliferation, migration, and invasion, and increased the number of MPM cells in the G0/G1 phase. In addition, MALAT1 could directly bind to miR-141-3p and inhibit its expression. YAP1 has been identified as a downstream target of miR-141-3p, and its expression level was inhibited by miR-141-3p. MALAT1 can be used as a competitive endogenous RNA (ceRNA) to regulate the YAP1-Hippo signaling pathway through miR-141-3p, promote the proliferation, migration, and invasion of MPM cells, and provide a new target for the therapy of MPM.

10.
ACS Nano ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34761898

RESUMO

Diabetic wound healing is one of the major challenges in the biomedical fields. The conventional single drug treatments have unsatisfactory efficacy, and the drug delivery effectiveness is restricted by the penetration depth. Herein, we develop a magnesium organic framework-based microneedle patch (denoted as MN-MOF-GO-Ag) that can realize transdermal delivery and combination therapy for diabetic wound healing. Multifunctional magnesium organic frameworks (Mg-MOFs) are mixed with poly(γ-glutamic acid) (γ-PGA) hydrogel and loaded into the tips of MN-MOF-GO-Ag, which slowly releases Mg2+ and gallic acid in the deep layer of the dermis. The released Mg2+ induces cell migration and endothelial tubulogenesis, while gallic acid, a reactive oxygen species-scavenger, promotes antioxidation. Besides, the backing layer of MN-MOF-GO-Ag is made of γ-PGA hydrogel and graphene oxide-silver nanocomposites (GO-Ag) which further enables excellent antibacterial effects for accelerating wound healing. The therapeutic effects of MN-MOF-GO-Ag on wound healing are demonstrated with the full-thickness cutaneous wounds of a diabetic mouse model. The significant improvement of wound healing is achieved for mice treated with MN-MOF-GO-Ag.

11.
Aging Cell ; : e13510, 2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34719871

RESUMO

Citrate is an essential substrate for energy metabolism that plays critical roles in regulating cell growth and survival. However, the action of citrate in regulating metabolism, cognition, and aging at the organismal level remains poorly understood. Here, we report that dietary supplementation with citrate significantly reduces energy status and extends lifespan in Drosophila melanogaster. Our genetic studies in fruit flies implicate a molecular mechanism associated with AMP-activated protein kinase (AMPK), target of rapamycin (TOR), and ketogenesis. Mice fed a high-fat diet that supplemented with citrate or the ketone body ß-hydroxybutyrate (ßOHB) also display improved metabolic health and memory. These results suggest that dietary citrate supplementation may prove to be a useful intervention in the future treatment of age-related dysfunction.

12.
13.
Artigo em Inglês | MEDLINE | ID: mdl-34769968

RESUMO

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) caused the global pandemic of coronavirus disease 2019 (COVID-19). Rapid identification and isolation of infectious patients are critical methods to block COVID-19 transmission. Antigen tests can contribute to prompt identification of infectious individuals. This meta-analysis aims to evaluate the diagnostic accuracy of antigen tests for SARS-CoV-2. We conducted a literature search in PubMed, Embase, the Cochrane Library, and Biomed Central databases. Studies evaluating the diagnostic accuracy of antigen tests for SARS-CoV-2 in community participants were included. Only English-language articles were reviewed. We included eligible studies that provided available data to construct a 2 × 2 table on a per-patient basis. Overall sensitivity and specificity for antigen tests were generated using a bivariate random-effects model. Eighteen studies with 34,865 participants were retrieved. The meta-analysis for SARS-CoV-2 antigen tests generated a pooled sensitivity of 0.82 and a pooled specificity of 1.00. A subgroup analysis of ten studies that reported outcomes for 5629 symptomatic participants generated a pooled sensitivity of 0.87 and a pooled specificity of 1.00. Antigen tests might have higher sensitivity in detecting SARS-CoV-2 in symptomatic patients in the community and may be an effective tool to identify patients to be quarantined to prevent further SARS-CoV-2 transmission.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Programas de Rastreamento , Pandemias , Sensibilidade e Especificidade
14.
Polymers (Basel) ; 13(21)2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34771404

RESUMO

In the current study, lignin, an abundant natural polymer, was dissolved in ethylene glycol and acidic H2O to form nanoscale lignin. Then, zero-valent iron (ZVI) nanoparticles were synthesized in nanoscale lignin, producing a nZVI/n-lignin composite, via the borohydride reduction method. The use of nZVI/n-lignin for environmental remediation was tested by the removal of methylene blue in aqueous solutions at room temperature. The nZVI/n-lignin composite achieved a higher methylene blue removal ratio than that achieved by traditional nZVIs. Moreover, its excellent dispersibility in water and stability against oxidation in the air were observed. The functions of the nanoscale lignin in the composite material are (1) prevention of further growth and aggregation of the nZVI nanoparticles, (2) protection of nZVI from serious oxidation by H2O/O2, and (3) allowing better dispersibility of nZVI in aqueous solutions. These three functions are important for the field applications of nZVI/n-lignin, namely, to travel long distances before making contact with environmental pollutants. The present method for producing nZVI/n-lignin is straightforward, and the combination of nZVI and lignin is an efficient and environmentally friendly material for environmental applications.

15.
Materials (Basel) ; 14(21)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34772059

RESUMO

Powder metallurgy (PM) is a versatile process to manufacture nearly net-shaped metallic materials in industry. In this study, the PM process was used to fabricate two Fe-based laminated metal composites (LMCs), Fe-4Ni-3Cr-0.5Mo-0.5C/Fe and 410/304L. The results showed that after sintering, the LMCs were free of interfacial cracks and distortion, indicating that the PM process is a feasible means for producing these LMCs. In the Fe-4Ni-3Cr-0.5Mo-0.5C/Fe LMC, the diffusion of C resulted in the generation of a continuous pearlite layer between the Fe-4Ni-3Cr-0.5Mo-0.5C and Fe layers and a ferrite/pearlite mixture in the Fe layer. In the 410/304L LMC, the difference in the chemical potentials of C between the 304L and 410 layers led to the uphill diffusion of C from the 410 layer to the 304L layer. A continuous ferrite layer was thus formed near the interface of the 410 layer. Furthermore, a martensite layer of about 50 µm thickness was generated at the interface due to the high Cr and Ni content.

16.
Artigo em Inglês | MEDLINE | ID: mdl-34769646

RESUMO

Ventilator-associated pneumonia is a common hospital-acquired infection. It causes patients to stay longer in the hospital and increases medical costs. This study explores the effect of applying an automatic medical information system to implement five-item prevention care bundles on the prevention of ventilator-related pneumonia. This study was a retrospective cohort study. This study was conducted from October 2017 to February 2018 and collected data from the intensive care unit of a medical center in southern Taiwan from January 2013 to May 2016. The control group (enrolled from January 2013 to June 2014) received oral hygiene. The experimental group (enrolled from July 2014 to December 2015) received five-item ventilator-associated pneumonia prevention care bundles, which consisted of (1) elevation of the head of the bed to 30-45°; (2) daily oral care with 0.12-0.2% chlorhexidine twice daily; (3) daily assessment of readiness to extubate; (4) daily sedative interruption; and (5) emptying water from the respirator tube. Results showed the incidence of ventilator-associated pneumonia in the bundle group was significantly less than the oral hygiene group (p = 0.029). The factors that significantly affected the incidence of ventilator-associated pneumonia were ventilator-associated pneumonia care bundle, ventilator-days, and intensive care unit length of stay. A significant reduction in ventilator-associated pneumonia rate in the bundle group compared to the oral hygiene group (OR = 0.366, 95% CI = 0.159-0.840) was observed, with 63.4% effectiveness. Application of an automatic medical information system to implement bundle care can significantly reduce the incidence of ventilator-associated pneumonia.


Assuntos
Pacotes de Assistência ao Paciente , Pneumonia Associada à Ventilação Mecânica , Humanos , Sistemas de Informação , Unidades de Terapia Intensiva , Pneumonia Associada à Ventilação Mecânica/epidemiologia , Pneumonia Associada à Ventilação Mecânica/prevenção & controle , Estudos Retrospectivos
17.
J Mech Behav Biomed Mater ; 125: 104972, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34794044

RESUMO

Poly(ether-ether-ketone) (PEEK) with good biocompatibility exhibits high mechanical strengths but bioinert. In addition, tantalum (Ta) possesses outstanding osteogenesis but high density and elastic modulus, and cost. In this study, by blending Ta nanoparticles with PEEK, Ta/PEEK composite (TP) was prepared, which was then treated by concentrated sulfuric acid to form a microporous surface containing Ta particles on TP (TPS). Moreover, genistein (GS) with antibacterial property was loaded into the microporous surface of TPS (TPSG). Compared with TP, the surface properties (e.g., surface roughness and hydrophilicity) of TPS was obviously improved because of the microporous surface including Ta nanoparticles. Moreover, TPS showed low antibacterial properties because of presence of sulfonic group while TPSG exhibited excellent antibacterial properties due to GS loaded into the microporous surface. Furthermore, compared with TP, TPS obviously promoted attachment and proliferation of MG63 cells, while TPSG with GS remarkably inducing osteogenic differentiation of the cells compared with TPS in vitro. Moreover, in comparison with TP, TPS with optimized surface properties promoted new bone regeneration and osseointegration, while TPSG loading GS further enhanced bone regeneration as well as osseointegration in vivo. In summary, the GS loaded into microporous surface including Ta nanoparticles of TPSG exhibited antibacterial and osteogenic activity, which would have great potential for bone tissue repair.

18.
Sci Total Environ ; : 151711, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34800457

RESUMO

The outbreak of COVID-19 has led to the large-scale usage of chlorinated disinfectants in cities. Disinfectants and disinfection by-products (DBPs) enter rivers through urban drainage and surface runoff. We investigated the variations in residual chlorine, DBPs, and different aquatic organisms in the Hanjiang, Fuhe, and Qinglinghe Rivers in Wuhan during the COVID-19 pandemic. The sampling sites were from the wastewater treatment plant outlets to the downstream drinking water treatment plant intakes. Total residual chlorine and DBPs (dichloromethane and trichloromethane) detected in the river water ranged from 0 to 0.84 mg/L and 0 to 0.034 mg/L, respectively. The residual chlorine and DBPs showed a gradual reduction pattern related to water flow, and the concentration at intakes did not exceed the Chinese drinking water source quality standards. Phytoplankton and zooplankton densities were not significantly correlated with residual chlorine and DBPs. The fluctuations in phytoplankton resource use efficiency (RUE) and zooplankton RUE in the Fuhe River, with the highest residual chlorine, and the Qinglinghe River with the highest DBPs, were higher than those in the Hanjiang River. For benthic macroinvertebrates, the number of functional feeding groups in the Hanjiang River was higher than that in the Fuhe and Qinglinghe Rivers. The water and sediment bacterial communities in the Hanjiang River differed significantly from those in the Fuhe and Qingling Rivers. The denitrification function involved in N metabolism was stronger in the Fuhe and Qinglinghe Rivers. Structural equation modelling revealed that residual chlorine and DBPs impacted the diversity of benthos through direct and indirect effects on plankton. Although large-scale chlorine-containing disinfectants use occurred during the investigation, it did not harm the density of the detected aquatic organisms in water sources. With the regular use of chlorinated disinfectants for indoor and outdoor environments in response to the SARS-CoV-2 globally, it is still necessary to study the long-term and accumulated responses of water ecosystems exposed to chlorine-containing disinfectants.

19.
Med Image Anal ; 75: 102259, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34800788

RESUMO

In this paper, we present a Deep Convolutional Neural Networks (CNNs) for fully automatic brain tumor segmentation for both high- and low-grade gliomas in MRI images. Unlike normal tissues or organs that usually have a fixed location or shape, brain tumors with different grades have shown great variation in terms of the location, size, structure, and morphological appearance. Moreover, the severe data imbalance exists not only between the brain tumor and non-tumor tissues, but also among the different sub-regions inside brain tumor (e.g., enhancing tumor, necrotic, edema, and non-enhancing tumor). Therefore, we introduce a hybrid model to address the challenges in the multi-modality multi-class brain tumor segmentation task. First, we propose the dynamic focal Dice loss function that is able to focus more on the smaller tumor sub-regions with more complex structures during training, and the learning capacity of the model is dynamically distributed to each class independently based on its training performance in different training stages. Besides, to better recognize the overall structure of the brain tumor and the morphological relationship among different tumor sub-regions, we relax the boundary constraints for the inner tumor regions in coarse-to-fine fashion. Additionally, a symmetric attention branch is proposed to highlight the possible location of the brain tumor from the asymmetric features caused by growth and expansion of the abnormal tissues in the brain. Generally, to balance the learning capacity of the model between spatial details and high-level morphological features, the proposed model relaxes the constraints of the inner boundary and complex details and enforces more attention on the tumor shape, location, and the harder classes of the tumor sub-regions. The proposed model is validated on the publicly available brain tumor dataset from real patients, BRATS 2019. The experimental results reveal that our model improves the overall segmentation performance in comparison with the state-of-the-art methods, with major progress on the recognition of the tumor shape, the structural relationship of tumor sub-regions, and the segmentation of more challenging tumor sub-regions, e.g., the tumor core, and enhancing tumor.

20.
Front Microbiol ; 12: 768283, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34721370

RESUMO

The order Sulfolobales (phylum Crenarchaeota) is a group of thermoacidophilic archaea. The first member of the Sulfolobales was discovered in 1972, and current 23 species are validly named under the International Code of Nomenclature of Prokaryotes. The majority of members of the Sulfolobales is obligately or facultatively chemolithoautotrophic. When they grow autotrophically, elemental sulfur or reduced inorganic sulfur compounds are their energy sources. Therefore, sulfur metabolism is the most important physiological characteristic of the Sulfolobales. The functions of some enzymes and proteins involved in sulfur reduction, sulfur oxidation, sulfide oxidation, thiosulfate oxidation, sulfite oxidation, tetrathionate hydrolysis, and sulfur trafficking have been determined. In this review, we describe current knowledge about the physiology, taxonomy, and sulfur metabolism of the Sulfolobales, and note future challenges in this field.

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