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1.
Nat Prod Bioprospect ; 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389713

RESUMO

Natural products, with remarkable chemical diversity, have been extensively investigated for their anticancer potential for more than a half-century. The collective efforts of the community have achieved the tremendous advancements, bringing natural products to clinical use and discovering new therapeutic opportunities, yet the challenges remain ahead. With remarkable changes in the landscape of cancer therapy and growing role of cutting-edge technologies, we may have come to a crossroads to revisit the strategies to understand nature products and to explore their therapeutic utility. This review summarizes the key advancements in nature product-centered cancer research and calls for the implementation of systematic approaches, new pharmacological models, and exploration of emerging directions to revitalize natural products search in cancer therapy.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33400502

RESUMO

Although mixed matrix membranes (MMM) possess remarkably improved gas separation performance compared to traditional polymeric membranes, membrane stability including CO2 plasticization and aging is still a serious issue due to the existence of interfacial defects. In this work, we report an efficient and less destructive route to cross-link the MOFs/polyimide (PI) MMM, where amine group-functionalized MOF (NH2-UiO-66) nanoparticles are thermally cross-linked with a carboxylic acid-functionalized PI (COOH-PI) matrix to form an amide bond at the interface at 150 °C under vacuum condition. Such a chemical cross-linking strategy conducted at a relatively mild condition improves membrane stability greatly while ensuring that the membrane structure is not destroyed. The resulting cross-linked MMM achieves enhanced mechanical strength with higher Young's modulus than a pristine polymer membrane. The CO2 antiplasticization pressure of the MMM after cross-linking is enhanced by 200% from ∼10 to >30 bar and the CO2 permeability of MMM only drops slightly from 995 to 735 Barrer after 450 days. At the same time, the separation performance of H2/CH4 gas pair surpasses the 2008 upper bound and that of CO2/CH4 gas pair nearly approaches the 2008 upper bound. The cross-linking strategy used herein provides a feasible and effective route for improving membrane stability and membrane performance in the MMM system for gas separation.

3.
BMC Infect Dis ; 21(1): 29, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413185

RESUMO

BACKGROUND: Serum levels of procalcitonin (PCT) are considered a useful biomarker for the diagnosis of bacterial infection or inflammation. There are few reports of high PCT levels in end-stage liver disease regardless of bacterial infection. Here, we present a case of extremely high PCT levels (> 100 ng/mL) in a patient with severe cirrhosis combined with hepatic carcinoma. CASE PRESENTATION: A 65-year-old man developed end-stage cirrhosis with hepatic carcinoma. Radiographic imaging showed a massive hepatocellular carcinoma with multiple loci lack of indications of resection. Hence, transcatheter hepatic arterial chemoembolization was performed three times over a period of 4 months. Before and after interventional therapies, the biochemistry laboratory results were only slightly abnormal except for persistently high PCT concentrations (> 100 ng/mL), irrespective of the evidence for bacterial infection or sepsis. CONCLUSIONS: This case suggests that continuously high levels of PCT (> 100 ng/mL) may be present in advanced liver disease, particularly in complex situations such as decompensated cirrhosis and liver cancer, in the absence of severe infection or sepsis. This knowledge could expand the significance of PCT in liver disease.

4.
J Pept Sci ; 27(1): e3286, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32945039

RESUMO

Chemical protein modifications facilitate the investigation of natural posttranslational protein modifications and allow the design of proteins with new functions. Proteins can be modified at a late stage on amino acid side chains by chemical methods. The indole moiety of tryptophan residues is an emerging target of such chemical modification strategies because of its unique reactivity and low abundance. This review provides an overview of the recently developed methods of tryptophan modification at the peptide and protein levels.

5.
J Hazard Mater ; 404(Pt A): 124077, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33053475

RESUMO

To improve biodegradation strategies for chlorinated pollutants, the roles of soil organic matter and microbial function need to be clarified. It was hypothesised that microbial degradation of specific organic fractions in soils enhance community metabolic capability to degrade chlorinated pollutants. This field study used historic records of dieldrin concentrations since 1988 and established relationships between dieldrin dissipation and soil carbon fractions together with bacterial and fungal diversity in surface soils of Kurosol and Chromosol. Sparse partial least squares analysis linked dieldrin dissipation to metabolic activities associated with the highly decomposed carbon fraction. Dieldrin dissipation, after three decades of natural attenuation, was associated with increased bacterial species fitness for the decomposition of recalcitrant carbon substrates including synthetic chlorinated pollutants. These metabolic capabilities were linked to the decomposed carbon fraction, an important driver for the microbial community and function. Common bacterial traits among taxonomic groups enriched in samples with high dieldrin dissipation included their slow growth, large genome and complex metabolism which supported the notion that metabolic strategies for dieldrin degradation evolved in an energy-low soil environment. The findings provide new perspectives for bioremediation strategies and suggest that soil management should aim at stimulating metabolism at the decomposed, fine carbon fraction.

6.
Ultrason Sonochem ; 70: 105348, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32971393

RESUMO

The present work investigated the effects of sonication at different amplitudes and durations on the in vitro digestibility of buckwheat protein isolates (BPIs). The conformation, particle size and microstructures of the BPIs were also studied to explicate the possible mechanisms of the sonication-induced changes. The results showed that sonication conditions of 20 kHz, pulsed on-time 10 s, off-time 5 s, amplitude of 60% and duration of 10 min (SA6T10) improved the digestibility of BPIs from 41.4% (control) to 58.2%. The tertiary structure analysis showed that sonication exposed the hydrophobic core buried inside the protein molecules and broke the intramolecular crosslinks, based on the increase in the surface hydrophobicity and intrinsic fluorescence and the decrease in the disulphide content. The secondary structure analysis showed that SA6T10 decreased the content of ß-turn and ß-sheet by 40.9% and 22.4%, respectively, and increased the content of anti-parallel ß-sheet, random coil, and α-helix by 40.9%, 30.6%, and 25.5%, respectively. The particle size of the control BPIs (427.7 ± 76.7 nm) increased to 2130.8 ± 356.2 nm in the SA6T10 sonicated sample with a corresponding decrease in the polydispersity index from 0.97 ± 0.04 to 0.51 ± 0.13. Moreover, scanning electron microscopy indicated that sonication broke the macroparticles into smaller fragments and changed the surface state of the proteins. Taken together, sonication has proven to be a promising approach for improving the digestibility of buckwheat proteins, which can be explored as a source of plant-based alternative protein for food applications.

7.
Phytomedicine ; 80: 153394, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33130472

RESUMO

BACKGROUND: Programmed death-ligand 1 (PD-L1), which can be induced by interferon-gamma (IFN-γ) in the tumor microenvironment, is a critical immune checkpoint in cancer immunotherapy. Natural products which reduce IFN-γ-induced PD-L1 might be exert immunotherapy effect. Licochalcone A (LCA), a natural compound derived from the root of Glycyrrhiza inflata Batalin. (Fabaceae), was found to interfere IFN-γ-induced PD-L1. PURPOSE: The aim of this study is to further clarify the effect and the mechanism of LCA on inhibiting IFN-γ-induced PD-L1 in lung cancer cells. METHODS: The expression levels of PD-L1 were evaluated by flow cytometry, western blot and qRT-PCR. Click-iT protein synthesis assay and luciferase assay were used to identify the effect of LCA on protein synthesis. Jurkat T cell proliferation and apoptosis in the co-culture system were detected by flow cytometry. Flow cytometry was also applied to evaluate reactive oxygen species (ROS) generation. RESULTS: LCA downregulated IFN-γ-induced PD-L1 protein expression and membrane localization in human lung cancer cells, regardless of inhibiting PD-L1 mRNA level or promoting its protein degradation. LCA decreased apoptosis and proliferative inhibition of Jurkat T cells caused by IFN-γ-induced PD-L1-expressing in A549 cells in the co-culture system. Strikingly, LCA was verified as a protein synthesis inhibitor, which reduced both cap-dependent and -independent translation. LCA inhibited PD-L1 translation, likely due to inhibition of 4EBP1 phosphorylation (Ser 65) and activation of PERK-eIF2α pathway. Furthermore, LCA induced ROS generation in a time-dependent manner in lung cancer cells. N-acetyl-L-cysteine (NAC) not only revered ROS generation triggered by LCA but also restored IFN-γ-induced expression of PD-L1. Both the inhibition of 4EBP1 phosphorylation (Ser 65) and activation of PERK-eIF2α axis triggered by LCA was restored by co-treatment with NAC. CONCLUSION: LCA abrogated IFN-γ-induced PD-L1 expression via ROS generation to abolish the protein translation, indicating that LCA has the potential to be applied in cancer immunotherapy.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antígeno B7-H1/metabolismo , Chalconas/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/efeitos dos fármacos , Antígeno B7-H1/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Interferon gama/metabolismo , Interferon gama/farmacologia , Células Jurkat , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Evasão Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
8.
J Med Chem ; 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33284613

RESUMO

Previously, we reported a first-in-class von Hippel-Lindau (VHL)-recruiting mitogen-activated protein kinase kinases 1 and 2 (MEK1/2) degrader, MS432. To date, only two MEK1/2 degrader papers have been published and very limited structure-activity relationships (SAR) have been reported. Here, we describe our extensive SAR studies exploring both von Hippel-Lindau (VHL) and cereblon (CRBN) E3 ligase ligands and a variety of linkers, which resulted in two novel, improved VHL-recruiting MEK1/2 degraders, 24 (MS928) and 27 (MS934), and the first CRBN-recruiting MEK1/2 degrader 50 (MS910). These compounds potently and selectively degraded MEK1/2 by hijacking the ubiquitin-proteasome system, inhibited downstream signaling, and suppressed cancer cell proliferation. Furthermore, concurrent inhibition of BRAF or PI3K significantly potentiated the antitumor activity of degrader 27, suggesting that the combination of MEK1/2 degradation with BRAF or PI3K inhibition may provide potential therapeutic benefits. Finally, besides being more potent, degrader 27 displayed improved plasma exposure levels in mice, representing the best MEK1/2 degrader to date for in vivo studies.

9.
Chin Med J (Engl) ; 133(23): 2822-2828, 2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-33273331

RESUMO

BACKGROUND: There are an increasing number of patients with oral sensory complaints (OSCs) presenting to our dental clinic. For most dentists, it is difficult to distinguish burning mouth syndrome (BMS) from other oral mucosal diseases that may cause symptoms such as burning mouth. It is beneficial to effectively distinguish OSC patients to reduce misdiagnosis and eliminate burning symptoms as much as possible. METHODS: Patients with oral burning sensations in the oral mucosal disease clinic were collected from the Peking University Hospital of Stomatology between September 1, 2014 and December 31, 2018. After excluding oral candidiasis, anemic stomatitis, dental material allergy, and other diseases from patients with oral sensory complaints, basic conditions such as gender, age, education level, job status, hyperglycemia, hypertension, hyperlipidemia, history of brain abnormalities, history of cervical spondylitis, history of thyroid disease, history of thyroid disease and insomnia were obtained. The BMS patients were compared with the control group. The t test and Chi-square test were used for statistical analysis to compare the clinical symptoms of these diseases and explore the risk factors for BMS. RESULTS: In this case-control study, 395 patients (321 females and 74 males, mean age 55.26 ±â€Š10.51 years) with oral sensory complaints and 391 healthy controls (281 females and 110 males, mean age 47.11 ±â€Š13.10 years) were enrolled, among which, 8.4% (33/395) had oral candidiasis, 1.3% (5/395) had dental material allergy, 0.8% (3/395) had anemic stomatitis and 0.5% (2/395) had lichen planus. A total of 352 patients were eventually diagnosed with BMS. Anxiety and depression were more severe in BMS patients, as were the incidences of sleep disorders and brain abnormalities. Logistic regression analysis showed that age (odds ratio [OR] = 2.79, 95% confidence interval [CI]: 1.61-4.83, P < 0.001), total cholesterol level (OR = 2.92, 95% CI: 1.32-6.50, P = 0.009) and anxiety score (OR = 1.75, 95% CI: 1.01-2.77, P = 0.017) significantly increased the incidence of BMS. Patients with hyperglycemia (OR = 0.46, 95% CI: 0.23-0.89, P = 0.022), low body mass index (BMI: OR = 0.57, 95% CI: 0.34-0.93, P = 0.026) and low education level (OR = 3.43, 95% CI: 1.91-6.15, P < 0.001) were more likely to suffer from BMS. CONCLUSIONS: Oral candidiasis, anemic stomatitis, and dental material allergy with burning symptoms should be excluded from patients with BMS. It is recommended to conduct a questionnaire survey (including anxiety and depression), blood cell analysis, and salivary fungus culture for all patients with an oral burning sensation. It is necessary to conduct a patch test on patients with oral burning sensations and metal restorations.

10.
Artigo em Inglês | MEDLINE | ID: mdl-33288692

RESUMO

Tibet's ancient topography and its role in climatic and biotic evolution remain speculative due to a paucity of quantitative surface-height measurements through time and space, and sparse fossil records. However, newly discovered fossils from a present elevation of ∼4,850 m in central Tibet improve substantially our knowledge of the ancient Tibetan environment. The 70 plant fossil taxa so far recovered include the first occurrences of several modern Asian lineages and represent a Middle Eocene (∼47 Mya) humid subtropical ecosystem. The fossils not only record the diverse composition of the ancient Tibetan biota, but also allow us to constrain the Middle Eocene land surface height in central Tibet to ∼1,500 ± 900 m, and quantify the prevailing thermal and hydrological regime. This "Shangri-La"-like ecosystem experienced monsoon seasonality with a mean annual temperature of ∼19 °C, and frosts were rare. It contained few Gondwanan taxa, yet was compositionally similar to contemporaneous floras in both North America and Europe. Our discovery quantifies a key part of Tibetan Paleogene topography and climate, and highlights the importance of Tibet in regard to the origin of modern Asian plant species and the evolution of global biodiversity.

11.
Med Res Rev ; 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33295676

RESUMO

Neurological disorders significantly outnumber diseases in other therapeutic areas. However, developing drugs for central nervous system (CNS) disorders remains the most challenging area in drug discovery, accompanied with the long timelines and high attrition rates. With the rapid growth of biomedical data enabled by advanced experimental technologies, artificial intelligence (AI) and machine learning (ML) have emerged as an indispensable tool to draw meaningful insights and improve decision making in drug discovery. Thanks to the advancements in AI and ML algorithms, now the AI/ML-driven solutions have an unprecedented potential to accelerate the process of CNS drug discovery with better success rate. In this review, we comprehensively summarize AI/ML-powered pharmaceutical discovery efforts and their implementations in the CNS area. After introducing the AI/ML models as well as the conceptualization and data preparation, we outline the applications of AI/ML technologies to several key procedures in drug discovery, including target identification, compound screening, hit/lead generation and optimization, drug response and synergy prediction, de novo drug design, and drug repurposing. We review the current state-of-the-art of AI/ML-guided CNS drug discovery, focusing on blood-brain barrier permeability prediction and implementation into therapeutic discovery for neurological diseases. Finally, we discuss the major challenges and limitations of current approaches and possible future directions that may provide resolutions to these difficulties.

12.
Med Res Rev ; 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33300614

RESUMO

Phosphatidylinositol 3-kinase gamma (PI3Kγ) has been regarded as a promising drug target for the treatment of advanced solid tumors, leukemia, lymphoma, and inflammatory and autoimmune diseases. However, the high level of structural conservation among the members of the PI3K family and the diverse physiological roles of Class I PI3K isoforms (α, ß, δ, and γ) highlight the importance of isoform selectivity in the development of PI3Kγ inhibitors. In this review, we provide an overview of the structural features of PI3Kγ that influence γ-isoform selectivity and discuss the structure-selectivity-activity relationship of existing clinical PI3Kγ inhibitors. Additionally, we summarize the experimental and computational techniques utilized to identify PI3Kγ inhibitors. The insights gained so far could be used to overcome the main challenges in development and accelerate the discovery of PI3Kγ-selective inhibitors.

13.
Crit Rev Food Sci Nutr ; : 1-13, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33191773

RESUMO

The need for protein in human nutrition is rapidly increasing because of the increasing world population and consumer preference for high-protein foods. Plant proteins are gaining attention as sustainable means of meeting the global protein need due to their lower carbon footprint. Nonetheless, the food industry has neglected or underutilized many plant proteins, including buckwheat protein. Buckwheat is a pseudocereal and its groats contain beneficial components such as proteins, dietary fiber, vitamins, and bioactive polyphenols. The protein quality of buckwheat seeds varies between the tartary and common buckwheat types; both are gluten-free and contain considerable amount of indispensable amino acids. This review provides a detailed discussion on the profile, amino acid composition, digestibility, allergenicity, functional properties, and bioactivity of buckwheat proteins. Prospects of processing buckwheat for improving protein digestibility and deactivating allergenic epitopes were also discussed. Based on the literature, buckwheat protein has a tremendous potential for utilization in structuring food products and developing peptide-based functional foods for disease prevention. Future research should develop new processing technologies for further improvement of the quality and functional properties of buckwheat protein in order to facilitate its utilization as an alternative plant-based protein toward meeting the global protein supply.

14.
Bioresour Technol ; 320(Pt A): 124307, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33157446

RESUMO

An instrument for the automatic preparation of microspheres was designed and manufactured, and by which cells were immobilized as efficient biocatalyst with small particle diameter, high crosslinking uniformity, and high porosity. The concentration of polymer solution, crosslinking agent and other conditions for preparing the cells microspheres were determined, and the conversion conditions of isonicotinic acid from 4-cyanopyridine were optimized to minimize mass-transfer limitations, and improve thermal and storage stability. The immobilized cells microspheres, which were continuously used for 23 batches, showed a total transformation capacity of 4.6 mol/L 4-cyanopyridine and a cumulative mass of 566.31 g/L of isonicotinic acid, which demonstrated the potential of the durable biocatalyst with efficient conversion capacity.

15.
Phytochemistry ; 181: 112536, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33160226

RESUMO

Seven undescribed indole-based alkaloids, xuefengins A-D and xuefenglasins A-C, were isolated from natural Ophiocordyceps xuefengensis, along with six known alkaloids. Their structures were elucidated by comprehensive spectroscopy, with absolute configurations confirmed by comparison with calculated electronic circular dichroism spectra. Eleven of the isolates were tested for cytotoxicity against the U937, NB4, MCF-7, Hep G2, and A549 cancer cell lines. Two compounds exhibited moderate activities, with IC50 values of 2.83-25.68 µM and 1.54-12.16 µM. Further pharmacological studies showed that these two compounds inhibit cell proliferation by inducing apoptosis, and decreasing p38 and caspase-3 levels in A549 cells.

16.
Sci Total Environ ; : 142836, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33160664

RESUMO

Changes in rhizodeposits of crops under elevated CO2 (eCO2) and elevated temperature (eT) may substantially impact on soil microbial community, which in turn affects soil carbon and nutrient cycling. However, the responses of soil bacterial community to long-term eCO2 and eT are not fully understood. A seven-year field experiment using open-top chambers was carried out with soybean (Glycine max L. Merr.) and maize (Zea mays L.) grown in a Mollisol soil under ambient CO2 (380 ppm), eT (2.1 °C increase in air temperature) and eTeCO2 (elevated temperature plus elevated CO2, 2.1 °C increase in air temperature and 700 ppm CO2). Soil DNA was extracted for Illumina MiSeq sequencing. The principal coordinate analysis showed that changes of bacterial community structure due to eT and eTeCO2 were greater in soybean- than maize-grown soils. The eT increased the relative abundances of Gaiella and Bacillus in Actinobacteria and Firmicutes, but decreased those of Nocardioides and H16 in Actinobacteria and Proteobacteria, respectively. The magnitudes of responses of seven genera sensitive to eT varied between soybean- and maize-grown soils. The eTeCO2 decreased the relative abundance of Bacillus and increased those of Gaiella, Streptomyces and Mizugakiibacter. The abundances of Gaiella, Gemmatimonas, and Mizugakiibacter under eTeCO2 were higher in soybean- than maize-grown soils. The redundancy analysis showed that soil organic C, moisture, nitrate, microbial biomass N and Olsen-P significantly affected soil bacterial community composition. All these results indicate that long-term eT increased the abundance of bacterial community and shifted their composition compared to the ambient control. In addition, the bacterial community composition under eTeCO2 was more stable in maize- than soybean-grown soils. The study suggests that warming and crop species may interactively affect the stability of bacterial community linking to the sustainability of soil eco-function in future cropping systems.

17.
ACS Appl Mater Interfaces ; 12(47): 53096-53103, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33169985

RESUMO

Covalent organic framework (COF)-based membranes are burgeoning candidates for separation technologies owing to their well-ordered channel structures. The exponential interest in the stability of the COF membrane on exposure to harsh organic solvents is directed to develop a composite membrane for dye separations in polar aprotic solvents. Here, we reported a nanocomposite membrane composing of a single-walled carbon nanotube (SWCNT)/COF (an imine-based COF) hybrid on a commercial polytetrafluoroethylene (PTFE) substrate, with a thickness of ∼58 nm prepared in a diffusion cell. This membrane displayed high permeability and stability toward nonpolar and aprotic solvents. It exhibited high permeability for lower viscous organic solvents such as hexane (66 L m-2 h-1 bar-1), acetone (60 L m-2 h-1 bar-1), and acetonitrile (59 L m-2 h-1 bar-1) with a desirable dye rejection (92.8% for Brilliant blue in acetone). The long-time operation demonstrated the excellent stability of the nanocomposite membrane. We herein reported a facile and mild method to prepare an ultrathin COF-based nanocomposite membrane with a porous, robust structure coupled with solvent durability capable of efficient dye separation.

18.
Drug Discov Today ; 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33197622

RESUMO

Immunotherapy has become an indispensable part of cancer treatment. A pivotal phagocytosis checkpoint, named cluster of differentiation 47 (CD47), which functions as 'don't eat me' signal to protect cells from phagocytosis upon interaction with signal regulatory protein alpha (SIRPα) on macrophages, has recently attracted much attention. Numerous antibodies targeting the CD47/SIRPα axis have shown encouraging efficacy in clinical trials. Meanwhile, studies on small-molecule inhibitors that interfere with CD47/SIRPα interaction or regulate CD47 expression are also in full swing. In this review, we summarize the small-molecule inhibitors interrupting the binding of CD47/SIRPα and regulating CD47 at the transcriptional, translational, and post-translational modification (PTM) levels. We provide perspectives and strategies for targeting the CD47/SIRPα phagocytosis checkpoint.

19.
Phys Rev E ; 102(4-1): 043108, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33212652

RESUMO

Influences of surface nanotubes at high temperatures are investigated on droplet impact dynamics and Leidenfrost effect. Five distinct regimes of impact droplets are found on the nanotube surface, including contact boiling, film levitation, central jet levitation, central jet, and Leidenfrost phenomenon. The regimes of film levitation, central jet levitation, and central jet are characterized by either film levitation and/or liquid central jet. The regime of Leidenfrost phenomenon is characterized by droplet bounce-off behavior free of any liquid jets. Film levitation is driven by the vaporization of two parts of the droplet, with one as the droplet bottom layer over the contact area above the nanotube structure, and the other as the hemiwicking liquid in nanotubes. Both the vaporization is impaired by increasing the surface temperature, which is attributed to the reduced contact time and less extent of spread of the droplet at a higher surface temperature. The central jet phenomenon is driven by the vapor stream produced by hemiwicking liquid in the central area upon impact. It is enhanced and then suppressed by elevating the surface temperature, resulting from the collective effects of the vapor pressure in nanotubes which increases with the surface temperature, and the cross-sectional area of the vapor stream, which increases and then decreases with the surface temperature. At a high Weber number, the Leidenfrost temperature can be increased by 125^{∘}C on the nanotube surface, implying a great potential in heat transfer enhancement for droplet-based applications.

20.
Biomed Res Int ; 2020: 7272960, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33150179

RESUMO

Bladder cancer (BLCA) is the most common urinary tract tumor and is the 11th most malignant cancer worldwide. With the development of in-depth multisystem sequencing, an increasing number of prognostic molecular markers have been identified. In this study, we focused on the role of protein-coding gene methylation in the prognosis of BLCA. We downloaded BLCA clinical and methylation data from The Cancer Genome Atlas (TCGA) database and used this information to identify differentially methylated genes and construct a survival model using lasso regression. We assessed 365 cases, with complete information regarding survival status, survival time longer than 30 days, age, gender, and tumor characteristics (grade, stage, T, M, N), in our study. We identified 353 differentially methylated genes, including 50 hypomethylated genes and 303 hypermethylated genes. After annotation, a total of 227 genes were differentially expressed. Of these, 165 were protein-coding genes. Three genes (zinc finger protein 382 (ZNF382), galanin receptor 1 (GALR1), and structural maintenance of chromosomes flexible hinge domain containing 1 (SMCHD1)) were selected for the final risk model. Patients with higher-risk scores represent poorer survival than patients with lower-risk scores in the training set (HR = 2.37, 95% CI 1.43-3.94, p = 0.001), in the testing group (HR = 1.85, 95% CI 1.16-2.94, p = 0.01), and in the total cohort (HR = 2.06, 95% CI 1.46-2.90, p < 0.001). Further univariate and multivariate analyses using the Cox regression method were conducted in these three groups, respectively. All the results indicated that risk score was an independent risk factor for BLCA. Our study screened the different methylation protein-coding genes in the BLCA tissues and constructed a robust risk model for predicting the outcome of BLCA patients. Moreover, these three genes may function in the mechanism of development and progression of BLCA, which should be fully clarified in the future.

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