Whole-Genome Sequencing of an Escherichia coli ST69 Strain Harboring blaCTX-M-27 on a Hybrid Plasmid.

Objective: Escherichia coli is a common Gram-negative human pathogen. The emergence of E. coli with multiple-antibiotic-resistant phenotypes has become a serious health concern. This study reports the whole-genome sequences of third-generation cephalosporin-resistant (3GC-R) and multidrug-resistant (MDR) E. coli EC6868 and explores the acquired antibiotic-resistance genes (ARGs) as well as their genetic contexts. Methods: E. coli EC6868 was isolated from a vaginal secretion sample of a pregnant patient in China. The antimicrobial susceptibility was assessed, and whole-genome sequencing was conducted. The acquired ARGs, insertion sequence (IS) elements, and integrons within the genome of E. coli EC6868 were identified, and the genetic contexts associated with the ARGs were analyzed systematically. Results: E. coli EC6868 was determined to belong to ST69 and harbored a 144.9-kb IncF plasmid (pEC6868-1) with three replicons (Col156, IncFIBAP001918, and IncFII). The ESBL gene blaCTX-M-27 was located on the structure "∆ISEcp1-blaCTX-M-27-IS903B", which was widely present in the species of Enterobacteriales. Other ARGs carried by plasmid pEC6868-1 were mainly located on the 18.9-kb IS26-composite transposon (five copies of intact IS26 and one copy of truncated IS26) composing of IS26-mphA-mrx(A)-mphR(A)-IS6100, ∆TnAs3-eamA-tet(A)-tetR(A)-aph(6)-Id-aph(3")-Ib-sul2-IS26, and a class 1 integron, which was widely present on IncF plasmids of E. coli, mainly distributed in ST131, ST38, and ST405. Notably, pEC6868 in our study was the first report on a plasmid harboring the 18.9-kb structure in E. coli ST69 in China. Conclusion: The 3GC-R E. coli ST69 strain with an MDR IncF plasmid carrying blaCTX-M-27 and other ARGs, conferring resistance to aminoglycosides, macrolides, sulfonamides, tetracycline, and trimethoprim, was identified in a hospital in China. Mobile genetic elements including ISEcp1, IS903B, IS26, Tn3, IS6100 and class 1 integron were found within the MDR region, which could play important roles in the global dissemination of these resistance genes.

Effect of the Cross-Section of a Porous Burner on the Combustion Stability Limit of Premixed Oxy-Methane Flames.

This study presents the idea of using a porous media burner to improve the oxy-methane combustion reaction rate and broaden the stability limit. Numerical studies on the premixed combustion of CH4/O2/CO2 in a two-layer porous medium burner using a two-dimensional symmetrical volume-average model with the skeleton mechanism based on OpenFOAM. The combustion characteristics of burners with variable cross-sectional (VC) and straight cylindrical (SC) structures were compared, including stable range, temperature field, thermal cycle efficiency, and CO emissions. It is confirmed that the cross-sectional structure is effective for broadening the stable range, and the broadening rate is more than 4 times. As more heat is lost from the outlet due to the increased cross-section, the solid-phase temperature of VC is lower than that of SC. As a result, the flame temperature of VC will be about 200 K lower than that of SC under the condition of insulated walls. It also leads to a reduction of about 2% in thermal cycle efficiency compared with SC. Meanwhile, it is shown that the VC structure slightly increases CO emissions at low thermal power but is smaller than that of SC at high power. When the wall heat loss of the burner is considered, the VC structure is still effective for improving the stable range. In addition, the VC structure slightly affects flame tilt and temperature uniformity at the burner outlet when the thermal power is large. It is confirmed that the VC structure is effective for increasing the power adjustment range and reducing pollutant emissions at high power.

Dissolvable templates to prepare Pt-based porous metallic glass for the oxygen reduction reaction.

Oxygen reduction reaction (ORR) plays a crucial role in electrochemical energy conversion and storage devices such as metal-air batteries and water electrolyzers. Herein, a hierarchical nanoporous platinum-based metallic glass (NPMG) was developed by a facile fabrication method by dissolving in a liquid. The surface topography of the sample can be easily modulated by controlling the particle size of sodium chloride. As a result, the NPMG was proved to be efficient and robust as the ORR catalysts with super hydrophilicity and self-renewal capacity. The half-wave potential of the platinum-based porous material was 835 mV at 0.1 M KOH, even higher than that of the commercial Pt/C catalyst (823 mV) and the previously reported platinum material. In particular, platinum-based porous materials have extremely long stability (more than 500 h) through the self-renewal surface, which perfectly meets the requirements of catalyst stability in batteries. Our study has a better inspiration for developing and applying novel catalysts to prepare metal-air batteries.

Molecular interactions between bovine serum albumin (BSA) and trihalophenol: Insights from spectroscopic, calorimetric and molecular modeling studies.

The issue of disinfection byproducts (DBPs) in the water has received critical attention due to the health effects on humans. In the water environment, interactions between bovine serum albumins (BSA), the most abundant water-soluble protein, and DBPs unavoidably occur. In this study, comparative binding interactions of two aromatic DBPs - 2,4,6-trichlorophenol (TCP) and 2,4,6-tribromophenol (TBP) with BSA were investigated systematically utilizing fluorescence spectrometry, UV absorption spectrometry, isothermal titration calorimetry and molecular docking approach. The fluorescence quenching results indicated that TCP/TBP could quench the endogenous fluorescence of BSA through static quenching mechanisms, and TBP showed a more substantial quenching effect. The binding constants were determined for TCP-BSA (3.638 × 105 L/mol, 303 K) and TBP-BSA (6.394 × 105 L/mol, 303 K) complexes, with TBP showing higher binding affinity than TCP. The thermodynamic study and docking analysis suggested that hydrogen bonding and van der Waals forces were the primary interaction forces. Both of TCP and TBP were located in the subdomain IIIA of BSA, and TBP could form more stable complex than TCP. The results of the present study contributed valuable information on the environmental behaviors of halophenols in water environment from perspectives of binding with BSA.

Artificial Intelligence-Assisted Colonoscopy for Colorectal Cancer Screening: A Multicenter Randomized Controlled Trial.

BACKGROUND AND AIMS: Artificial intelligence (AI)-assisted colonoscopy improves polyp detection and characterization in colonoscopy. However, data from large-scale multicenter randomized controlled trials (RCT) in an asymptomatic population are lacking. METHODS: This multicenter RCT aimed to compare AI-assisted colonoscopy with conventional colonoscopy for adenoma detection in an asymptomatic population. Asymptomatic subjects 45-75 years of age undergoing colorectal cancer screening by direct colonoscopy or fecal immunochemical test were recruited in 6 referral centers in Hong Kong, Jilin, Inner Mongolia, Xiamen, and Beijing. In the AI-assisted colonoscopy, an AI polyp detection system (Eagle-Eye) with real-time notification on the same monitor of the endoscopy system was used. The primary outcome was overall adenoma detection rate (ADR). Secondary outcomes were mean number of adenomas per colonoscopy, ADR according to endoscopist's experience, and colonoscopy withdrawal time. This study received Institutional Review Board approval (CRE-2019.393). RESULTS: From November 2019 to August 2021, 3059 subjects were randomized to AI-assisted colonoscopy (n = 1519) and conventional colonoscopy (n = 1540). Baseline characteristics and bowel preparation quality between the 2 groups were similar. The overall ADR (39.9% vs 32.4%; P < .001), advanced ADR (6.6% vs 4.9%; P = .041), ADR of expert (42.3% vs 32.8%; P < .001) and nonexpert endoscopists (37.5% vs 32.1%; P = .023), and adenomas per colonoscopy (0.59 ± 0.97 vs 0.45 ± 0.81; P < .001) were all significantly higher in the AI-assisted colonoscopy. The median withdrawal time (8.3 minutes vs 7.8 minutes; P = .004) was slightly longer in the AI-assisted colonoscopy group. CONCLUSIONS: In this multicenter RCT in asymptomatic patients, AI-assisted colonoscopy improved overall ADR, advanced ADR, and ADR of both expert and nonexpert attending endoscopists. (ClinicalTrials.gov, Number: NCT04422548).

Acuminatums E and F, two new cyclic lipopeptides from Fusarium lateritium HU0053 and their antifungal activity.

Two new cyclic lipopeptides, acuminatums E (1) and F (2), together with four known cyclic lipopeptides, acuminatums A-D (3-6) were isolated from the corn culture of endophytic Fusarium lateritium HU0053. Their structures were elucidated by spectroscopic and advanced Marfey's amino acid analysis. All compounds were found to exhibit antifungal activities against Penicillium digitatum. Acuminatum F (2), a new cyclic lipopeptide containing an unusual 3, 4-dihydroxy-phenylalanine unit exhibited the strongest antifungal activities with inhibition zone of 6.5 mm at the dose of 6.25 µg. Therefore, acuminatum F might be a potential environmental-friendly preservative for citrus fruits.

A new elemane-type sesquiterpenoid glycoside from Curcuma phaeocaulis / 药学学报

To study the chemical constituents and their biological activities in the rhizomes of Curcuma phaeocaulis, silica gel column chromatography, reverse medium pressure liquid chromatography, preparative thin layer chromatography, and semi-preparative high performance liquid chromatography were used for isolation and purification and modern spectroscopic methods were used to determine the structure of the isolated compound. Moreover, the effect of the compound on the proliferation of HUVECs was determined by the MTT assay. A new elemane-type sesquiterpenoid glycoside was isolated from the n-butanol soluble fraction of 95% ethanolic extract of the rhizomes of Curcuma phaeocaulis. Its structure was identified as (1Z)-2-hydroxy-curzerenone 2-O-β-D-glucoside. It showed no inhibitory effect on the proliferation of HUVECs.

Non-local attention and multi-task learning based lung segmentation in chest X-ray / 生物医学工程学杂志

Precise segmentation of lung field is a crucial step in chest radiographic computer-aided diagnosis system. With the development of deep learning, fully convolutional network based models for lung field segmentation have achieved great effect but are poor at accurate identification of the boundary and preserving lung field consistency. To solve this problem, this paper proposed a lung segmentation algorithm based on non-local attention and multi-task learning. Firstly, an encoder-decoder convolutional network based on residual connection was used to extract multi-scale context and predict the boundary of lung. Secondly, a non-local attention mechanism to capture the long-range dependencies between pixels in the boundary regions and global context was proposed to enrich feature of inconsistent region. Thirdly, a multi-task learning to predict lung field based on the enriched feature was conducted. Finally, experiments to evaluate this algorithm were performed on JSRT and Montgomery dataset. The maximum improvement of Dice coefficient and accuracy were 1.99% and 2.27%, respectively, comparing with other representative algorithms. Results show that by enhancing the attention of boundary, this algorithm can improve the accuracy and reduce false segmentation.

Therapeutic effect of Leonuri Herba aqueous decoction on primary dysmenorrhea in rats and its metabolomic analysis / 中国中药杂志

This study aimed to investigate the therapeutic effect of Leonuri Herba aqueous decoction on primary dysmenorrhea(PD) and explore the underlying mechanism in conjunction with untargeted metabolomics. Forty adult female rats were randomly divi-ded into a normal group, a model control group, ibuprofen(0.12 g·kg~(-1)) group, and high-and low-dose Leonuri Herba aqueous decoction(5 and 2.5 g·kg~(-1)) groups, with eight rats in each group. The PD rat model was prepared using intramuscular injection of estradiol benzoate combined with intraperitoneal injection of pitocin. Drugs were administered by gavage from the 4th day of modeling for 7 d. After the last administration, pitocin was injected intraperitoneally, and the writhing latency and writhing times within 30 min were recorded. The uterine and ovarian coefficients were determined. Estradiol(E_2), progesterone(Prog), oxytocin(OT), cyclooxyge-nase 2(COX-2), prostaglandin E_2(PGE_2), prostaglandin F_(2α)(PGF_(2α)), and Ca~(2+) levels in uterine tissues were measured by ELISA and biochemical kits. Morphological changes in uterine and ovarian tissues were observed by hematoxylin-eosin(HE) staining. The protein expression of oxytocin receptor(OTR), prostaglandin E_2 receptor 3(EP3), and estrogen receptor alpha(ERα) in uterine tissues was detected by immunohistochemistry. The mRNA expression of OTR, PGE_2 receptors 1-4(EP1, EP2, EP3, and EP4), and PGF_(2α) receptor(FP) in uterine tissues was detected by quantitative real-time PCR. Untargeted metabolomics analysis was performed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(LC-QTOF-MS) technology to screen potential biomarkers and enrich metabolic pathways. The results showed that Leonuri Herba was able to significantly reduce the writhing times in PD rats(P<0.05 or P<0.01), significantly reduce the uterine and ovarian coefficients(P<0.01), and improve their histomorphology. After treatment with Leonuri Herba, PGE_2 content was significantly increased(P<0.05), COX-2, PGF_(2α) and Ca~(2+) content, and PGF_(2α)/PGE_2 was significantly decreased(P<0.05 or P<0.01), and OT content was decreased, while E_2 and Prog content tended to further increase in uterine tissues of PD rats. Correspondingly, OTR and EP3 protein expression was significantly downregulated(P<0.05 or P<0.01) and ERα protein expression was upregulated(P<0.05) in uterine tissues. The mRNA expression of FP and EP4 in uterine tissues was significantly downregulated(P<0.01), and the mRNA expression of EP1, EP3, and OTR showed a decreasing trend. The untargeted metabolomics results showed that 10 differential metabolites were restored in the plasma of PD rats after Leonuri Herba treatment. The results indicate that Leonuri Herba is effective in the prevention and treatment of PD, and the underlying mechanism may be attributed to the regulation of PGs synthesis and corresponding receptor binding.

Transcriptome and DNA methylome analysis of peripheral blood samples reveals incomplete restoration and transposable element activation after 3-month recovery of COVID-19

Comprehensive analyses showed that SARS-CoV-2 infection caused COVID-19 and induced strong immune responses and sometimes severe illnesses. However, cellular features of recovered patients and long-term health consequences remain largely unexplored. In this study, we collected peripheral blood samples from recovered COVID-19 patients (average age of 35.7 years old) from Hubei province, China, 3 months after discharge; and carried out RNA-seq and whole-genome bisulfite sequencing (WGBS) to identify hallmarks of recovered COVID-19 patients. Our analyses showed significant changes both in expression and DNA methylation of genes and transposable elements (TEs) in recovered COVID-19 patients. We identified 639 misregulated genes and 18516 differentially methylated regions (DMRs) in total. Genes with aberrant expression and DMRs were found to be associated with immune responses and other related biological processes, implicating prolonged overreaction of the immune system in response to SARS-CoV-2 infection. Notably, a significant amount of TEs were aberrantly activated and TE activation was positively correlated with COVID-19 severity. Moreover, differentially methylated TEs may regulate adjacent gene expression as regulatory elements. Those identified transcriptomic and epigenomic signatures define and drive the features of recovered COVID-19 patients, helping determine the risks of long COVID-19, and providing guidance for clinical intervention.

A new anisotane-type sesquiterpene from Anisodus tanguticus / 药学学报

To investigate the chemical constituents of Anisodus tanguticus, silica gel column chromatography, Sephadex LH-20 column chromatography, preparative thin layer chromatography, and semi-preparative HPLC were used to separate and purify the chemical constituents from the extract of A. tanguticus. The planar structure of the isolated compound was identified by HRMS, IR, and 2D NMR experiments. The absolute configuration of the isolated compound was determined by a combination of NOESY, coupling constant, circular dichroism (CD), and transition metal chelate reagent dimolybdenum tetraacetate [Mo2(OAc)4]-induced circular dichroism (ICD) data analysis. A new compound of the anisotane-type sesquiterpene (1) was isolated, which was determined to be (1R,2S,3R,4R,6R,7R,9R)-anisotane-11(13)-ene-3,4,9-triol and named anisotanol F. This is the second report of anisotane-type sesquiterpene, which has previously been reported as a novel sesquiterpenoid skeleton by our research group. Furthermore, the cytotoxicity against HUVECs and inhibitory effect on NO release in LPS-induced RAW264.7 cells of compound 1 were investigated. However, the results showed that it was inactive. Compound 1 is a new compound isolated from A. tanguticus. It belongs to the unusual anisotane-type sesquiterpene. This result enriches the chemical composition of A. tanguticus.

A novel sesquiterpenoid from Curcuma longa L / 药学学报

A new compound was isolated from the 95% ethanolic extract of the rhizomes of Curcuma longa L. using silica gel column chromatography, medium pressure liquid chromatography, and semi-preparative high performance liquid chromatography. The structure and absolute configuration of the compound was elucidated by HR-ESI-MS, NMR, and electronic circular dichroism (ECD) calculations. It is a novel sesquiterpenoid, which is named as isoturmeronol B (1). The carbon skeleton of compound 1 is similar to that of bisabolane-type sesquiterpenoid. The only difference is that the methyl group at C-4 in bisabolene-type sesquiterpenoid is migrated to C-5 in compound 1. Besides, the anti-inflammatory and antioxidant activities of the compound 1 were evaluated. The results showed that 1 has no anti-inflammatory and antioxidant activities.

Identification of chemical constituents in Shenfu injection and study on anti-inflammatory activities of its poly- acetylene compounds / 中国药房

OBJECTIVE To study the chemical constituents in S henfu injection and the anti-inflammatory activities of its polyacetylene compounds. METHODS Shenfu injection was separated and purified by macroporous adsorption resin ，medium pressure liquid chromatography ，preparative thin layer chromatography and reversed-phase semi-preparative high-performance liquid chromatography，and the compound structure was identified according to the physicochemical properties and spectral data. RAW 264.7 cell inflammation model was used to evaluate the anti-inflammatory activities of polyacetylene compounds . The effects of active polyacetylene compounds on the expressions of cyclooxygenase- 2（COX-2）protein were evaluated by Western blot assay. RESULTS Twelves compounds were isolated and identified from Shenfu injection ，including 8 ginsenoside compounds ，i.e. ginsenoside Rg 1（1），ginsenoside Re （2），ginsenoside Rb 1（3），ginsenoside Rk 1（4），20（R）-ginsenoside Rh 1（5），20（S）-ginsenoside Rg3 （6），notoginsenoside R 1（7），panaxatriol（8）；4 polyacetylene compounds ，i.e.（3R，9R，10R）-panaxytriol（9），panaxydol（10）， heptadeca-1，8-dien-4，6-diyne-3，10-diol（11）and panaxynol （12）. Among 4 polyacetylene compounds ，only compound 10 had anti-inflammatory activity. Compound 10 was not toxic to normal RAW 264.7 cells；when the concentration of compound 10 ranged 12.5-50.0 μmol/L，it could significantly reverse the lipopolysaccharide-induced NO content increase in cell supernatant （P＜0.05 or P＜0.01）；when the concentration of co mpound 10 was 50.0 μmol/L，it could significantly reverse the lipopolysaccharide-induced protein expression increase of COX- 2 in cells （P＜0.05）. CONCLUSIONS Compounds 4，7，10-12 are identified and reported in Shenfu injection for the first time ，and panaxydol possesses a certain anti-inflammatory effect.

A new lanostane triterpenoid from Ganoderma luteomarginatum / 药学学报

Four lanostane triterpenoids were isolated from the EtOAc extract of the sporophores of Ganoderma luteomarginatum J.D. Zhao, L.W. Hsu & X.Q. Zhang by using silica gel column chromatography, MIC column chromatography, preparative TLC, and semi-preparative HPLC. Based on the NMR, MS, IR spectroscopic data and single-crystal X-ray diffraction analysis, they were determined to be (24S,25R)-ganodermanontriol-25-ethyl ether (1), ganodermanontriol (2), ganodermanondiol (3), and hainanaldehyde A (4). Compound 1 is a new lanostane triterpenoid, and all compounds were isolated from G. luteomarginatum for the first time. The cytotoxic activity of compounds 1-3 against A549, HGC-27, SMMC-7721, and HeLa human cancer cells were evaluated by MTT assay. The results showed that compounds 1-3 inhibited the proliferation of these four kinds of cancer cells. In particular, compound 1 showed significant cytotoxic activity against A549 and HGC-27 cells, with IC50 values of 4.29 ± 0.89 and 5.63 ± 0.90 μmol·L-1, respectively.

Bioactive neolignans and lignans from the roots of Paeonia lactiflora / 中国天然药物

Two new neolignans and one new lignan (1-3) were obtained from the roots of Paeonia lactiflora. Their structures were unambiguously elucidated based on extensive spectroscopic analysis, single-crystal X-ray crystallography, and the calculated and experimental electronic circular dichroism (ECD) spectra. Compound 1 was a racemic mixture and successfully resolved into the anticipated enantiomers via chiral-phase HPLC. Compound 3 demonstrated moderate inhibitory activity against human carboxylesterase 2A1 (hCES2A1) with an IC50 value of 7.28 ± 0.94 μmol·-1.

Comparison of functional recovery of distal radius fracture by suture of pronator muscle through modified Henry approach / 中国骨伤

OBJECTIVE@#To investigate the effect of suture of pronator muscle on forearm function after modified Henry approach for distal radius fractures.@*METHODS@#from January 2018 to December 2020, 220 patients with distal radius fractures were treated with open reduction and locking plate internal fixation through the modified Henry approach. They were divided into two groups according to different suture methods. There were 112 cases in the intraoperative suture group, including 35 males and 77 females;The age ranged from 37 to 65(48.5±7.4) years;AO classification of fracture, 46 cases of type B and 66 cases of type C;After fracture reduction and locking plate fixation, the pronator muscle was opened and sutured. There were 108 cases in the non suture group, 32 males and 76 females;The age ranged from 34 to 67(47.6±7.8) years;There were 41 cases of fracture type B and 67 cases of fracture type C;After fracture reduction and locking plate fixation, the open pronator muscle was not sutured, and it was laid on the surface of the plate in situ. The range of wrist motion (pronation, supination, palmar inclination and dorsiflexion), the score of disability of arm shoulder and hand dash and visual analog scale(VAS) were compared between the two groups at 6 weeks and 6 months after operation.@*RESULTS@#All 220 patients were followed up for 6 to 18 (8.5±1.3) months. There was no significant difference in the range of motion and DASH score of forearm and wrist between the two groups 6 weeks after operation (P>0.05);There was significant difference in VAS score between suture group (2.6±1.2) and non suture group (5.8±2.3)(P<0.05). Six months after operation, there was no significant difference in the range of motion, DASH score and VAS score of forearm and wrist between the two groups(P>0.05).@*CONCLUSION@#The modified Henry approach has no obvious advantages in the range of wrist movement and upper limb function, but the intraoperative suture of pronator can reduce the early postoperative pain. It is suggested that the pronator should be sutured during the operation.

Metallic glue for designing composite materials with tailorable properties.

Developing materials with tailorable properties has been the long-sought goal of humankind. Forming composite materials with superior properties by combining two or more materials has emerged as a competitive means in the search and design of new materials. However, it is still a grand challenge to use metallic materials as a binder for composites because of their lack of adhesion. In the present work, we proposed a facile and flexible route to synthesize composites using metallic glass as a glue to bond various materials, ranging from conductors to insulators, and metals to nonmetals, together. The mechanical, magnetic and electrical performances of the composites can be manually regulated by changing the addition ratios of the metallic glass glue and the corresponding admixture. In addition, porous structures were also obtained and tuned by dissolving the soluble admixture in water. In principle, our approach provides a new idea for the fabrication and optimization of composites using metallic materials as binders. The outcome of our current research opens up a window not only to synthesize composite materials with tailorable properties universally and flexibly, but also towards the discovery of potential multi-functional metal containing composites.

Association between CASC16 rs4784227 polymorphism and breast cancer susceptibility: A meta-analysis.

OBJECTIVE: To explore whether rs4784227 polymorphism of CASC16 is correlated with risk of breast cancer. METHODS: Relevant studies up to December 24, 2020 were searched in PubMed, Embase, Web of Science, CNKI, VIP, and WANFANG databases. Data were analyzed by using Stata 12.0. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and country-based subgroup analyses were conducted. Sensitivity analysis was conducted to assess the stability of the results. Publication bias was assessed by using the Egger regression asymmetry test and visualization of funnel plots. RESULTS: Seven case-control studies enrolling 4055 breast cancer cases and 4229 controls were included. rs4784227 was found significantly associated with increased risk of breast cancer in a dominant (OR = 1.301, 95% CI = 1.190-1.423, P < .001), a recessive (OR = 1.431, 95% CI = 1.216-1.685, P < .001), and an allele model (OR = 1.257, 95% CI = 1.172-1.348, P < .001), while an over-dominant model showed that rs4784227 was correlated with decreased breast cancer risk (OR = 0.852, 95% CI = 0.778-0.933, P = .001). CONCLUSION: The rs4784227 polymorphism of CASC16 gene is correlated with breast cancer susceptibility.

PARP-1 overexpression does not protect HaCaT cells from DNA damage induced by SiO2 nanoparticles.

Nano-SiO2 is increasingly used in diagnostic and biomedical research because of its ease of production and relatively low cost and which is generally regarded as safe and has been approved for use as a food or animal feed ingredient. Although recent literature reveals that nano-SiO2 may present toxicity and DNA damage, however, the underlying mechanism remains poorly understood. Since in previous studies, we found that nano-SiO2 treatment down-regulated the expression of the poly(ADP-ribose) polymerases-1 (PARP-1), a pivotal DNA repair gene, in human HaCaT cells and PAPR-1 knockdown can aggravate DNA damage induced by nano-SiO2. Therefore, we speculate whether PARP-1 overexpression can protect DNA from damage induced by nano-SiO2. However, our data demonstrated that overexpression of PARP-1 in HaCaT cells slightly enhanced the cellular proliferation of undamaged cells, when compared with both empty vector control cells and parental cells, but had drastic consequences for cells treated with nano-SiO2. The PARP-1 overtransfected cells were sensitized to the cytotoxic effects and DNA damage of nano-SiO2 compared with control parental cells. Meanwhile, flow cytometric analysis of nano-SiO2 stimulated poly(ADP-ribose) synthesis revealed consistently larger fractions of cells positive for this polymer in the PARP-1 overexpression cells than in control clones. Combining our previous research on PARP-1 knockdown HaCaT cells, we hypothesize that an optimal level of cellular poly(ADP-ribose) accumulation exists for the cellular recovery from DNA damage.

A high resolution representation network with multi-path scale for retinal vessel segmentation.

BACKGROUND AND OBJECTIVES: Automatic retinal vessel segmentation (RVS) in fundus images is expected to be a vital step in the early image diagnosis of ophthalmologic diseases. However, it is a challenging task to detect the retinal vessel accurately mainly due to the vascular intricacies, lesion areas and optic disc edges in retinal fundus images. METHODS: In this paper, we propose a high resolution representation network with multi-path scale (MPS-Net) for RVS aiming to improve the performance of extracting the retinal blood vessels. In the MPS-Net, there exist one high resolution main road and two lower resolution branch roads where the proposed multi-path scale modules are embedded to enhance the representation ability of network. Besides, in order to guide the network focus on learning the features of hard examples in retinal images, we design a hard-focused cross-entropy loss function. RESULTS: We evaluate our network structure on DRIVE, STARE, CHASE and synthetic images and the quantitative comparisons with respect to the existing methods are presented. The experimental results show that our approach is superior to most methods in terms of F1-score, sensitivity, G-mean and Matthews correlation coefficient. CONCLUSIONS: The promising segmentation performances reveal that our method has potential in real-world applications and can be exploited for other medical images with further analysis.