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1.
Water Res ; 196: 117014, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33751971

RESUMO

Freshwater lakes are threatened by harmful cyanobacterial blooms, whose basic unit is Cyanobacterial Aggregate (CA). CA-attached bacteria play a significant role through different blooming stages with substantial variation of their taxonomic structure. However, little is known about their functional variations and functional links with cyanobacteria due to the lack of reference genomes. In this longitudinal study, we collected 16 CA samples from Lake Taihu, one of China's largest freshwater lakes, from April 2015 to February 2016, and sequenced their V4 region of 16S rRNA genes, full metagenomes (MG), and metatranscriptomes (MT). The analysis of these data revealed the dynamics of microbial taxonomic and functional structure in CAs, influenced by both external environmental factors and internal metabolism. 55 OTUs, 456 genes, and 37 transcripts showed significantly differential abundance across the early, middle, and late blooming stages (ANOVA test, P < 0.05). Total nitrogen and total phosphorus were proved to be the most important environmental drivers of microbial taxonomic and functional variations in CAs (Mantel's r > 0.25, P < 0.05). We constructed 161 high-quality metagenome-assembled genomes (MAGs), out of which 22 were cyanobacterial strains with diverse energy pathways, transporters and prokaryotic defense systems. Based on these MAGs, we constructed a cyanobacteria-bacteria co-nitrogen-pathway and a cyanobacteria-bacteria co-phosphorus-pathway, by which we demonstrated how nitrogen and phosphorus influence the dynamics of the microbial structure to a certain extent by affecting these co-pathways. Overall, these results characterized the taxonomic, functional, and transcriptional variations of microbes in CAs through different blooming stages. Genome assembly and metabolic analysis of cyanobacteria and their attached bacteria suggested that the material exchange and signal transduction do, indeed, exist among them. Our understanding of the underlying molecular pathways for cyanobacterial blooms could lead to the control of blooms by interventional strategies to disrupt critical microbes' expression.


Assuntos
Cianobactérias , Microbiota , China , Cianobactérias/genética , Eutrofização , Proliferação Nociva de Algas , Lagos , Estudos Longitudinais , RNA Ribossômico 16S/genética
2.
Int J Infect Dis ; 105: 418-423, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33676002

RESUMO

OBJECTIVES: To investigate the factors and virological significance of serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) status after long-term antiviral therapy with nucleos(t)ide analogues (NAs) in patients with chronic hepatitis B (CHB). METHODS: In total, 51 treatment-naïve patients with CHB were included in the study. Clinical data were collected at baseline, during 5 years and at year 10 of NA treatment. Serum HBV pgRNA status of 51 patients was determined at year 5. RESULTS: At year 5, 45% of the patients remained positive for HBV pgRNA. There were significant differences in baseline hepatitis B e antigen (HBeAg) status, HBV DNA load and hepatitis B surface antigen (HBsAg) levels between patients testing positive and negative for HBV pgRNA at year 5. Serum HBV pgRNA status and serum HBV DNA load were correlated after 5 years of NA treatment (r = 0.347, P = 0.013). Being HBV pgRNA positive at year 5 was an independent risk factor for sustainedly undetectable HBV DNA after 10 years of NA treatment (odds ratio 13.638, 95% confidence interval 1.32-140.81; P = 0.028). Furthermore, HBV pgRNA status at year 5 was associated with HBV DNA re-appearance at year 10 (P = 0.009). CONCLUSIONS: HBV pgRNA status at year 5 can reveal HBV covalently closed circular DNA (cccDNA) activity, and HBV pgRNA positivity after long-term antiviral therapy may indicate higher transcriptional activity of HBV cccDNA. Long-term dynamic monitoring of HBV pgRNA should be considered.

3.
Cancer Med ; 10(5): 1880-1888, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33595913

RESUMO

BACKGROUND: The mechanism of rapidly increased non-small cell lung cancer (NSCLC) among never-smoking Chinese women has not been elucidated. Ovarian sex steroid hormones have been suggested to counteract lung cancer development, and sex hormone-binding globulin (SHBG) is essential in sex hormones regulation. This study aims to exploring single nucleotide polymorphisms (SNPs) in genomic regions associated with SHBG concentrations that contributed to never-smoking female NSCLC. METHODS: Candidate genes were selected by a genome-wide association (GWAS) meta-analysis and gene expression profiles of never-smoking NSCLC of Chinese women. The candidate SNPs limited to common minor allele frequency (MAF), missense variant, ethnic heterogeneous distribution, and SNPs were genotyped using the TaqMan method. A two-stage case-control design was adopted for exploration and validation of associations between candidate SNPs and risk of NSCLC. All participants were never-smoking Chinese women. Chi-square test and multivariate logistic regression were applied. RESULTS: Beginning with 12 genomic regions associated with circulating SHBG concentrations and gene expression profiles from never-smoking NSCLC in Chinese women, candidate SNP rs12233719 and rs7439366 both located in candidate gene UGT2 B7, which may be related to circulating SHBG concentrations and cancer risk, were identified. A two-stage case-control study was conducted in Shenyang and Tianjin represented as the training stage and validation stage, respectively. Under the dominant model, compared to individuals with the wild G/G genotype, the adjusted OR of those with the T allele was 1.58 (95% CI: 1.15-2.16) in Chinese Shenyang training set, and was 1.49 (95% CI: 1.02-2.18) in Chinese Tianjin validation set, both accompanied with a significant trend relationship consistently. UGT2B7 was upregulated in female NSCLC patients' tumor tissues and was associated with a poor prognosis in NSCLC. CONCLUSION: Our findings indicated that a sex hormones regulation-related SNP rs12233719 was associated with never-smoking female lung cancer risk, which might partially explain NSCLC-susceptibility in Chinese women.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33607296

RESUMO

Identification of significant biological relationships or patterns is central to many metagenomic studies. Methods that estimate association networks have been proposed for this purpose; however, they assume that associations are static, neglecting the fact that relationships in a microbial ecosystem may vary with changes in environmental factors, which can result in inaccurate estimations. Therefore, this paper proposes a computational model, called the k-Lognormal-Dirichlet-Multinomial (kLDM) model, which estimates multiple association networks that correspond to specific environmental conditions, and simultaneously infers microbe-microbe and environmental factor-microbe associations for each network. The effectiveness of the kLDM model was demonstrated on synthetic data, a colorectal cancer (CRC) dataset, the Tara Oceans dataset, and the American Gut Project dataset. The results reveal that the widely-used Spearman's rank correlation coefficient (SCC) method performed much worse than the other methods, indicating the importance of separating samples by environmental conditions. Cancer fecal samples were then compared with cancer-free samples, and the estimation achieved by kLDM exhibited fewer associations among microbes but stronger associations between specific bacteria, especially five CRC-associated operational taxonomic units (OTUs), indicating gut microbe translocation in cancer patients. Some environmental factor-dependent associations were then found within a marine eukaryotic community. Finally, the gut microbial heterogeneity of irritable bowel disease (IBD) patients was detected. These results demonstrate that kLDM can elucidate the complex associations within microbial ecosystems. The kLDM program, R, and Python scripts, together with all experimental datasets, are accessible at https://github.com/tinglab/kLDM.git.

5.
Artigo em Inglês | MEDLINE | ID: mdl-33295092

RESUMO

The distribution of counterions around a macroion is an important feature for macroionic systems. Here we report the determination of the accurate number and the spatial distribution of countercations (Sr 2+ , Rb + ) around a rigid, spherical, 2.9-nm size polyoxometalate cluster, {Mo 132 } 42- , using anomalous small angle X-ray scattering (ASAXS). The results show that both Rb + and Sr 2+ ions have shorter diffuse lengths than theoretical prediction. In addition, most of Rb + ions are closely associated with {Mo 132 } by staying near the skeleton of {Mo 132 } or in the Stern layer, whereas Sr 2+ ions preferred to loosely associate with {Mo 132 } in the diffuse layer. The results also explain the observations that monovalent Rb + ions have a stronger affinity towards {Mo 132 } in comparison to divalent Sr 2+ ions, as well as the anomalous lower critical coagulation concentration (CCC) of {Mo 132 } in the presence of Rb + ions compared to Sr 2+ ions. The anomalous CCC behavior of {Mo 132 } can be attributed to most of the negative charges being located on the inner surface of its cavity. The longer anion-cation distance weakens the Coulomb interaction and, hence, making the enthalpy change due to the breakage of hydration layers of cations more important in regulating the counterion-{Mo 132 } interaction. Macroions with charges distributed on their external surfaces, e.g., {U 60 }, do not show such abnormal behavior.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33269903

RESUMO

We report the mechanism of hydrogel formation in dilute aqueous solutions (>15 mg/mL) by 2 nm metal-organic cages (MOCs). Experiments and all-atom simulations confirm that with the addition of small electrolytes, the MOCs self-assemble into 2D nanosheets via counterion-mediated attraction because of their unique molecular structure and charge distribution as well as σ-π interactions. The stiff nanosheets are difficult to bend into 3-D hollow, spherical blackberry type structures, as observed in many other macroion systems. Instead, they stay in solution and their very large excluded volumes lead to gelation at low (∼1.5 wt %) MOC concentrations, with additional help from hydrophobic and partial π-π interactions similar to the gelation of graphene oxides.

7.
Mol Microbiol ; 2020 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-33372330

RESUMO

The recombination of short homologous ends in Escherichia coli has been known for 30 years, and it is often used for both site-directed mutagenesis and in vivo cloning. For cloning, a plasmid and target DNA fragments were converted into linear DNA fragments with short homologous ends, which are joined via recombination inside E. coli after transformation. Here this mechanism of joining homologous ends in E. coli was determined by a linearized plasmid with short homologous ends. Two 3'-5' exonucleases ExoIII and ExoX with nonprocessive activity digested linear dsDNA to generate 5' single-strand overhangs, which annealed with each other. The polymerase activity of DNA polymerase I (Pol I) was exclusively employed to fill in the gaps. The strand displacement activity and the 5'-3' exonuclease activity of Pol I were also required, likely to generate 5' phosphate termini for subsequent ligation. Ligase A (LigA) joined the nicks to finish the process. The model involving 5' single-stranded overhangs is different from established recombination pathways that all generate 3' single-stranded overhangs. This recombination is likely common in bacteria since the involved enzymes are ubiquitous.

8.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 36(12): 1124-1128, 2020 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-33325365

RESUMO

Objective To investigate the relationship between the expression of serum antigen KI-67 (ki67) and the clinicopathological characteristics of breast cancer patients, and to demonstrate the consistency between serum ki67 detection and immunohistochemical staining (IHC) in breast cancer patients. Methods The study enrolled 10 healthy women, 10 patients with benign breast masses and 86 with invasive breast cancer. ELISA was used to detect the relationship between serum ki67 levels and clinicopathological characteristics. Meanwhile, IHC was performed to study the relationship between the expression of ki67 and the clinicopathology in breast cancer tissues. Results The serum ki67 level in the healthy women was similar with the benign breast patients. But, the serum ki67 level in the breast patients significantly increased. The serum ki67 level in the breast cancer patients was closely related to lymph node metastasis, and was not obviously related to other clinicopathological features. The high expression of ki67 in breast cancer tissues was related to tumor size, histological grade, lymph node metastasis, estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2(HER2), while it is not related with the age of patients. Conclusion The serum ki67 level is higher in breast cancer patients, but the test result alone was not as valuable as IHC in predicting the clinical diagnosis and treatment for breast cancer patients.


Assuntos
Neoplasias da Mama , Antígeno Ki-67/sangue , Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Feminino , Humanos , Metástase Linfática , Prognóstico , Receptor ErbB-2 , Receptores Estrogênicos , Receptores de Progesterona
9.
PeerJ ; 8: e9832, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194351

RESUMO

A new basal ornithopod dinosaur, based on two nearly complete articulated skeletons, is reported from the Lujiatun Beds (Yixian Fm, Lower Cretaceous) of western Liaoning Province (China). Some of the diagnostic features of Changmiania liaoningensis nov. gen., nov. sp. are tentatively interpreted as adaptations to a fossorial behavior, including: fused premaxillae; nasal laterally expanded, overhanging the maxilla; shortened neck formed by only six cervical vertebrae; neural spines of the sacral vertebrae completely fused together, forming a craniocaudally-elongated continuous bar; fused scapulocoracoid with prominent scapular spine; and paired ilia symmetrically inclined dorsomedially, partially covering the sacrum in dorsal view. A phylogenetic analysis places Changmiania liaoningensis as the most basal ornithopod dinosaur described so far. It is tentatively hypothesized that both Changmiania liaoningensis specimens were suddenly entrapped in a collapsed underground burrow while they were resting, which would explain their perfect lifelike postures and the complete absence of weathering and scavenging traces. However, further behavioural inference remains problematic, because those specimens lack extensive sedimentological and taphonomic data, as it is also the case for most specimens collected in the Lujiatun Beds so far.

10.
BMC Gastroenterol ; 20(1): 381, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33198637

RESUMO

BACKGROUND: Lipid profiles are declined in patients with viral liver cirrhosis and correlated with severity of liver disease. Hepatitis B virus (HBV) is the leading cause of liver cirrhosis in China. Our primary aim was to investigate whether serum lipids and lipoproteins associate with survival in patients with HBV-related cirrhosis and acute gastrointestinal bleeding, and develop a 6-week mortality risk score that incorporates it. METHODS: From January 2008 to December 2015, consecutive cirrhotic patients with acute gastrointestinal bleeding admitted to our hospital were evaluated and randomly divided into the derivation (n = 629) and validation (n = 314) cohorts. A logistic regression model was established to confirm the association between lipoprotein cholesterol and mortality. Accuracy to predict mortality were assessed by area under the receiver operating characteristic curves (AUROCs) and compared using the Hanley and McNeil test. RESULTS: Among study subjects, the 6-week mortality rate was 10.6%. High-density lipoprotein cholesterol (HDL-C) level was found to correlate most strongly with prognostic scores. On ROC analysis, HDL-C showed excellent diagnostic accuracy for 6-week mortality. Logistic regression analysis provided a simple algorithm based on the combined use of 4 variables (total bilirubin (TBIL), HDL-C, International normalized ratio, and hemoglobin), allowing accurate discrimination of 3 distinct prognostic subgroups with 1.7% (low risk), 12.3% (intermediate risk), and 56.9% (high risk) mortality. Its accuracy was significantly better than that of Child-Pugh, model of end-stage liver disease, albumin-bilirubin score, D'Amico model, Augustin model, AIMS65 score and Glasgow-Blatchford score. Baseline HDL-C values ≤ 0.54 mmol/L were associated with markedly lower 6-week survival. Comparable results were found in the validation set. CONCLUSION: HDL-C is a potential indicator for the prognosis of patients with cirrhosis and acute gastrointestinal bleeding. The new algorithm based on HDL-C allowed an accurate predictive assessment of 6-week mortality after bleeding attack.

11.
Respir Res ; 21(1): 298, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176778

RESUMO

INTRODUCTION: Calcium is an important coagulation factor and hypocalcemia is related to progression and poor prognosis of many cardiopulmonary diseases. However, influence of hypocalcemia on pulmonary thromboembolism (PTE) prognosis has never been reported. This study aimed to explore its prognostic value and optimize the pulmonary embolism severity index (PESI), the widely used prognosis assessment model, based on the value. METHODS: PTE patients' variables in PESI and other related clinical characteristics including admission serum calcium were collected. Associations between these variables and PTE mortality were assessed by logistic regression and cox analysis. Variables significantly associated with 30-day PTE mortality were included to develop a new prognosis prediction rule and then its validity was compared with PESI and simplified PESI (sPESI). RESULTS: 496 PTE patients were included and 49.48% patients had hypocalcemia (serum calcium ≤ 2.13 mmol/L) in admission, showing higher 7-day (P = 0.021), 14-day (P = 0.002), 30-day (13.03% vs 4.98%, P = 0.002) mortalities than patients without hypocalcemia. Adjusting for variables in PESI, hypocalcemia was further revealed to be an independent predictor of 30-day mortality (P = 0.014). The optimal prediction rule contained hypocalcemia and 5 variables in PESI and sPESI, showing higher predictive validity [sensitivity (Sen): 0.930, specificity (Spec): 0.390, area under curve (AUC): 0.800] than PESI (Sen: 0.814, Spec: 0.367, AUC: 0.716) and sPESI (Sen: 0.907, Spec: 0.216, AUC: 0.703). CONCLUSIONS: Hypocalcemia is an independent predictor of the mortality following acute PTE. Based on hypocalcemia, the optimal prediction rule showed higher validity than PESI and sPESI.

12.
PLoS One ; 15(9): e0238768, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32911490

RESUMO

Water conservation is an important service function of ecosystems. A timely understanding of dynamic changes in the water conservation function is important for the protection and reconstruction of water resources. Based on remote sensing data, meteorological data, land cover data, and the "Technical Criterion for Ecosystem Status Evaluation" issued by the Ministry of Environmental Protection of the People's Republic of China, a comprehensive evaluation system was designed to assess the water conservation function of the Xiongan New Area from 2005 to 2015. The system created from four aspects, including ecological structure, ecological stress, water balance and landscape ecology. The results showed that from 2005 to 2015, the water conservation function of the Xiongan New Area first decreased and then increased, and the overall trend was upward. The increasing areas were mainly concentrated around Baiyangdian and near the grassland. Among all evaluated indicators, the precipitation compliance rate index fluctuated the most from -16.62 in 2010 to 6.70 in 2015. The evapotranspiration index was the largest in 2010 (6.47) and the smallest in 2005 (3.52). The Temperature Vegetation Dryness Index (TVDI) showed that the drought was the severest in 2010 and the least severe in 2015. However, the other indicators remain relatively stable. From the perspective of the spatial distribution, the water conservation function of the Xiongan New Area was gradually enhanced from north to south.


Assuntos
Conservação dos Recursos Hídricos/métodos , China , Conservação dos Recursos Hídricos/estatística & dados numéricos , Secas , Monitoramento Ambiental , Florestas , Modelos Estatísticos
13.
J Phys Chem Lett ; 11(17): 7224-7231, 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32790316

RESUMO

As ideal building blocks for optoelectronic devices, one-dimensional (1D) single-crystal perovskite microwires (MWs) have received widespread attention due to their unique physical and chemical properties. Herein, a one-step solution in-plane self-assembly method is proposed to directly grow millimeter-long CsPbBr3 MWs with superior crystal quality at atmospheric environment. This method effectively avoids the use of toxic antisolvents. Furthermore, a MW-based photodetector is successfully fabricated, showing high photoresponsivity (20 A/W) and fast response (less than 0.3 ms). The stability of the photodetector is also confirmed by aging MW in air for 60 days, which shows a negligible change of photocurrent from 1.29 to 1.25 nA (-3 V) under the same experimental conditions. This work provides a low-cost and fast synthesis method for the preparation of single-crystal perovskite MWs and demonstrates their potential application for high-performance and stable photoelectronic device.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32687695

RESUMO

Sitafloxacin, a new fluoroquinolone, has strong antibacterial activity. We evaluated the effects of sitafloxacin granules in single-dose and multidose cohorts and the effects of ABCB1, UGT1A1, and UGT1A9 genetic polymorphisms on the pharmacokinetics (PK) of sitafloxacin in healthy subjects. The single-dose study included 3 fasted cohorts receiving 50, 100, and 200 mg of sitafloxacin granules and 1 cohort receiving 50 mg of sitafloxacin granules with a high-fat meal. The multidose study included 1 cohort receiving 100 mg of sitafloxacin granules once daily for 5 days. PK parameters were calculated using noncompartmental parameters based on concentration-time data. The genotypes for ABCB1, UGT1A1, and UGT1A9 single-nucleotide polymorphisms were determined using Sanger sequencing. Subsequently, the association between sitafloxacin PK parameters and target single-nucleotide polymorphisms was analyzed. Sitafloxacin granules were well tolerated up to 200 and 100 mg in the single-dose and multidose studies, respectively. Sitafloxacin AUC and Cmax increased linearly within the detection range, and a steady state was reached within 3 days after the administration of multiple oral doses. Our findings showed that Cmax was lower in the ABCB1 (rs1045642) mutation group, whereas t1/2 was longer in the UGT1A1 (rs2741049) and UGT1A9 (rs3832043) mutation groups. In conclusion, sitafloxacin granules were safe at single doses and multiple doses up to 200 and 100 mg/day, respectively, with a linear plasma PK profile. However, ABCB1 (rs1045642), UGT1A1 (rs2741049), and UGT1A9 (rs3832043) genetic polymorphisms are likely to influence the Cmax or t1/2 and thereby merit further clinical evaluation.

15.
Ecol Evol ; 10(10): 4483-4494, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32489612

RESUMO

Understanding the mating system and reproductive success of a species provides evidence for sexual selection. We examined the mating system and the reproductive success of captive adult black sea bream (Acanthopagrus schlegelii), using parentage assignment based on two microsatellites multiplex PCR systems, with 91.5% accuracy in a mixed family (29 sires, 25 dams, and 200 offspring). Based on the parentage result, we found that 93.1% of males and 100% of females participated in reproduction. A total of 79% of males and 92% of females mated with multiple partners (only 1 sire and 1 dam were monogamous), indicating that polygynandry best described the genetic mating system of black sea bream. For males, maximizing the reproductive success by multiple mating was accorded with the sexual selection theory while the material benefits hypothesis may contribute to explain the multiple mating for females. For both sexes, there was a significant correlation between mating success and reproductive success and the variance in reproductive success of males was higher than females. Variation in mating success is the greatest determinant to variation in reproductive success when the relationship is strongly positive. The opportunity for sexual selection of males was twice that of females, as well as the higher slope of the Bateman curve in males suggested that the intensity of intrasexual selection of males was higher than females. Thus, male-male competition would lead to the greater variation of mating success for males, which caused greater variation in reproductive success in males. The effective population number of breeders (N b) was 33, and the N b/N ratio was 0.61, slightly higher than the general ratio in polygynandrous fish populations which possibly because most individuals mated and had offspring with a low variance. The relatively high N b contributes to the maintenance of genetic diversity in farmed black sea bream populations.

16.
J Sep Sci ; 43(16): 3183-3196, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32495501

RESUMO

Proton pump inhibitors, including omeprazole, rabeprazole, lansoprazole, and pantoprazole, achieved simultaneous enantioselective determination in the human plasma by chiral liquid chromatography-tandem mass spectrometry. The four corresponding stable isotope-labeled proton pump inhibitors were adopted as the internal standards. Each enantiomer and the internal standards were extracted with acetonitrile containing 0.1% ammonia, then separated with a Chiralpak IC column (5 µm, 4.6 mm × 150 mm) within 10 min. The mobile phase was composed of acetonitrile-ammonium acetate (10 mM) containing 0.2% acetic acid (50:50, v/v). To quantify all enantiomers, an API 4000 tandem mass spectrometer was used, and multiple reaction monitoring transitions were performed on m/z 360.1→242.1, 384.1→200.1, 370.1→252.1, and 346.1→198.1, respectively. No significant matrix effect was observed for all analytes. The calibration curve for all enantiomers were linear from 1.25 to 2500 ng/mL. The precisions for intra- and inter-run were < 14.2%, and the accuracy fell in the interval of -5.3 to 8.1%. Stability of samples was confirmed under the storage and processing conditions. The developed method was also suitable for separation and determination of ilaprazole enantiomers. The validated method combining the equilibrium dialysis method was applied to the protein binding ratio studies of four pairs proton pump inhibitor enantiomers in human plasma.

17.
Langmuir ; 36(17): 4702-4710, 2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32293900

RESUMO

Lactic acid-functionalized chiral fullerene (C60) molecules are used as models to understand chiral selection in macroionic solutions involving chiral macroions, chiral counterions, and/or chiral co-ions. With the addition of Zn2+ cations, the C60 macroions exhibit slow self-assembly behavior into hollow, spherical, blackberry-type structures, as confirmed by laser light scattering (LLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques. Chiral counterions with high charge density show no selection to the chirality of AC60 macroions (LAC60 and DAC60) during their self-assembly process, while obvious chiral discrimination between the assemblies of LAC60 and DAC60 is observed when chiral counterions with low charge density are present. Compared with chiral counterions, chiral co-ions show weaker effects on chiral selection with larger amounts needed to trigger the chiral discrimination between LAC60 and DAC60. However, they can induce a higher degree of discrimination when abundant chiral co-ions are present in solution. Furthermore, the self-assembly of chiral AC60 macroions is fully suppressed by adding significant amounts of neutral molecules with opposite chirality. Thermodynamic parameters from isothermal titration calorimetry (ITC) reveal that chiral selection is controlled by the ion pairing and the destruction of solvent shells between ions, and meanwhile originates from the delicate balance between electrostatic interaction and molecular chirality.

18.
Cancer Prev Res (Phila) ; 13(6): 551-562, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32161072

RESUMO

Sulforaphane (SFN), a potent antioxidant and antiinflammatory agent, has been shown to protect against cancers especially at early stages. However, how SFN affects UVB-mediated epigenome/DNA methylome and transcriptome changes in skin photodamage has not been fully assessed. Herein, we investigated the transcriptomic and DNA methylomic changes during tumor initiation, promotion, and progression and its impact and reversal by SFN using next-generation sequencing (NGS) technology. The results show that SFN reduced tumor incidence and tumor number. SFN's protective effects were more dramatic in the early stages than with later stages. Bioinformatic analysis of RNA sequencing (RNA-seq) data shows differential expressed genes and identifies the top canonical pathways related to SFN treatment of UVB-induced different stages of epidermal carcinogenesis. These pathways include p53 signaling, cell cycle: G2-M DNA damage checkpoint regulation, Th1, and Th2 activation pathway, and PTEN signaling pathways. The top upstream regulators related to UVB and SFN treatment as time progressed include dextran sulfate, TP53, NFE2L2 (Nrf2), IFNB1, and IL10RA. Bioinformatic analysis of Methyl-seq data shows several differential methylation regions induced by UVB were attenuated by SFN. These include Notch1, Smad6, Gnai3, and Apc2 Integrative analysis of RNA-seq and DNA-seq/CpG methylome yields a subgroup of genes associated with ultraviolet B (UVB) and SFN treatment. The changes in gene expression were inversely correlated with promoter CpG methylation status. These genes include Pik3cd, Matk, and Adm2 In conclusion, our study provides novel insights on the impact of SFN on the transcriptomic and DNA methylomic of UVB-induced different stages of skin cancer in mice.

19.
ACS Appl Mater Interfaces ; 12(13): 14784-14796, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32141282

RESUMO

Ideal wound dressing materials should be active components in the healing process. Bacterial cellulose (BC) has attracted a great deal of attention as novel wound dressing materials; however, it has no intrinsic antimicrobial activity. To explore the practical application values of BC and develop novel wound dressing materials, a series of composite membranes based on BC and polymeric ionic liquids (BC/PILs, composed of BC, and PILs formed by choline and different amino acids) with antimicrobial activity were synthesized by an ex situ method. The physicochemical and antimicrobial properties and biocompatibility of these membranes were systematically investigated. The results indicated that BC/PIL membranes with excellent properties could be obtained by adjusting the concentration and type of PILs. Several kinds of BC/PIL membranes exhibited good biocompatibility and high antimicrobial activity against Gram-positive and Gram-negative bacteria and fungus. The anionic PILs played important roles in the antimicrobial activity of BC/PIL membranes. The obtained membranes provided a novel promising candidate for wound dressing materials.

20.
Opt Lett ; 45(6): 1455-1458, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32163990

RESUMO

Three-dimensional (3D) range-gated imaging has great potential in underwater target detection, navigation, and marine scientific research due to good backscatter suppression. However, in turbid water, apparent backscatter leads to bad range resolution and accuracy in 3D reconstruction. To solve this problem, a 3D deblurring-gated range-intensity correlation imaging method is proposed based on light propagation property in water. In the method, only the water attenuation coefficient and a reference image are needed to calculate the depth-noise maps (DNM) of target gate images at different ranges. By subtracting the DNMs from target gate images, new gate images with less noise can be obtained, and then 3D images with high range resolution and accuracy are reconstructed. To prove the feasibility of the proposed method, experiments have been performed in pools under different water conditions. The results show that a higher peak signal-to-noise ratio improvement is about 9 dB in new gated images.

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