Publications by authors named "Guofeng Li"

113 Publications

Prognostic significance of micropapillary and solid patterns in stage IA lung adenocarcinoma.

Am J Transl Res 2021 15;13(9):10562-10569. Epub 2021 Sep 15.

Department of Thoracic Surgery, Tongji University Affiliated Shanghai Pulmonary Hospital Shanghai 200433, P. R. China.

Objective: To evaluate the value of the non-predominant micropapillary and solid patterns in prognosis of lung adenocarcinoma.

Methods: Totally 422 patients diagnosed with stage IA lung adenocarcinomas were included, and all their slides were reviewed. We compared clinicopathological characteristics and survival outcomes between MP- & SD- (both micropapillary and solid component were absent), MP+/SD+ (either micropapillary or solid component was present, but the single or combined percentage of the MP and SD was not greater than 50%) and MPp/SDp (either micropapillary or solid or the combined percentage of these two components was great than 50%).

Results: Patients with MP- & SD- had smaller tumor size (P=0.012) and lower spread through air spaces rates (P<0.001). Patients with MP- & SD- had significantly better 5-year recurrence free survival than MP+/SD+ (91% versus 70%, P<0.001) and MPp/SDp (91% versus 56%, P<0.001). The difference of RFS between MP+/SD+ subgroup and MPp/SDp subgroup was not significant (P=0.177). In the multivariate analysis, patients with MP- & SD- had a better recurrence free survival than the other two groups (versus: MP+/SD+, HR, 3.198; 95% CI, 1.537-6.653; P=0.002; versus MPp/SDp: HR, 4.981; 95% CI, 2.266-10.950; P<0.001).

Conclusions: The presence of micropapillary or solid patterns, even not predominant, was a risk factor for predicting poor recurrence free survival in very early stage lung adenocarcinoma.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8507014PMC
September 2021

Self-Assembled Nanosized Vehicles from Amino Acid-Based Amphiphilic Polymers with Pendent Carboxyl Groups for Efficient Drug Delivery.

Biomacromolecules 2021 11 12;22(11):4871-4882. Epub 2021 Oct 12.

State Key Laboratory of Organic-Inorganic Composites, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.

Developing safe and efficient delivery vehicles for chemotherapeutic drugs has been a long-standing demanding. Amino acid-based polymers are promising candidates to address this challenge due to their excellent biocompatibility and biodegradation. Herein, a series of well-defined amphiphilic block copolymers were prepared by PET-RAFT polymerization of -acryloyl amino acid monomers. By altering monomer types and the block ratio of the copolymers, the copolymers self-assembled into nanostructures with various morphologies, including spheres, rod-like, fibers, and lamellae via hydrophobic and hydrogen bonding interactions. Significantly, the nanoparticles (NPs) assembled from amphiphilic block copolymers poly(-acryloyl-valine)--poly(-acryloyl-aspartic acid) (PV--PD) displayed an appealing cargo loading efficiency (21.8-32.6%) for a broad range of drugs (paclitaxel, doxorubicin (DOX), cisplatin, etc.) due to strong interactions. The DOX-loaded PV--PD NPs exhibited rapid cellular uptake (within 1 min) and a great therapeutic performance. These drug delivery systems provide new insights for regulating the controlled morphologies and improving the efficiency of drug delivery.
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http://dx.doi.org/10.1021/acs.biomac.1c01164DOI Listing
November 2021

Educational attainment of offspring and obesity among older adults in China.

Soc Sci Med 2021 10 19;286:114325. Epub 2021 Aug 19.

School of Statistics, Shandong University of Finance and Economics, Jinan, Shandong, 250014, China.

The study focuses on the role of adult offspring's educational attainment in obesity among older adults in China and investigates age and birth cohort heterogeneities in the educational effect. Using the longitudinal data from the 1993-2015 China Health and Nutrition Survey (CHNS), we employed three-level mixed-effects models and conducted sex-stratified analyses to examine the effects of co-resident offspring's education on body mass index (BMI), overweight, waist circumference (WC), and abdominal obesity among older people born before 1956. After controlling for confounding factors, the overall results showed inverted U-shaped educational gradients in BMI-based outcomes for males and positive gradients for females. The effect of education on WC exhibited an inverted U-shaped pattern for both sexes, but no significant effect on abdominal obesity was found among the overall population. However, further analyses of interaction effects indicated considerable age and cohort variations in the educational effects on obesity outcomes. Offspring's schooling was positively associated with obesity among earlier birth cohorts; Among more recent birth cohorts, especially among females, the educational effects were reversed, and disparities in obesity outcomes across education categories strengthened with age. These findings imply that offspring's education appears to gradually exert a protective role against obesity among Chinese older adults in successive cohorts.
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http://dx.doi.org/10.1016/j.socscimed.2021.114325DOI Listing
October 2021

Phrenic nerve block during nonintubated video-assisted thoracoscopic surgery: a single-centre, double-blind, randomized controlled trial.

Sci Rep 2021 06 22;11(1):13056. Epub 2021 Jun 22.

Department of Anesthesiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, Guangdong Province, China.

There has been interest in the use of nonintubated techniques for video-assisted thoracoscopic surgery (VATS) in both awake and sedated patients. The authors' centre developed a nonintubated technique with spontaneous ventilation for use in a patient under general anaesthesia using a phrenic nerve block. This treatment was compared with a case-matched control group. The authors believe that this technique is beneficial for optimizing anaesthesia for patients undergoing VATS. The patients were randomly allocated (1:1) to the phrenic nerve block (PNB) group and the control group. Both groups of patients received a laryngeal mask airway (LMA) that was inserted after anaesthetic induction, which permitted spontaneous ventilation and local anaesthesia in the forms of a paravertebral nerve block, a PNB and a vagal nerve block. However, the patients in the PNB group underwent procedures with 2% lidocaine, whereas saline was used in the control group. The primary outcome included the propofol doses. Secondary outcomes included the number of propofol boluses, systolic blood pressure (SBP), pH values of arterial blood gas and lactate (LAC), length of LMA pulled out, length of hospital stay (length of time from the operation to the time of discharge) and complications after 1 month. Intraoperatively, there were increases in lactate (F = 12.31, P = 0.001) in the PNB group. There was less propofol (49.20 ± 8.73 vs. 57.20 ± 4.12, P = 0.000), fewer propofol boluses (P = 0.002), a lower pH of arterial blood gas (F = 7.98, P = 0.006) and shorter hospital stays (4.10 ± 1.39 vs. 5.40 ± 1.22, P = 0.000) in the PNB group. There were no statistically significant differences in the length of the LMA pulled out, SBP or complications after 1 month between the groups. PNB optimizes the anaesthesia of nonintubated VATS.
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http://dx.doi.org/10.1038/s41598-021-92003-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8219794PMC
June 2021

Xinmai 'an extract enhances the efficacy of sildenafil in the treatment of pulmonary arterial hypertension via inhibiting MAPK signalling pathway.

Pharm Biol 2021 Dec;59(1):594-605

Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou, China.

Context: Xinmai 'an tablet has been used to improve myocardial blood supply. Recently, some compounds from its formula have shown that they can treat pulmonary arterial hypertension (PAH).

Objective: This study investigates the effects of Xinmai 'an extract (XMA) on PAH and further tests the co-therapeutic enhancement with sildenafil (SIL).

Materials And Methods: Pulmonary artery smooth muscle cells were subjected to stimulation with SIL (12.5 μM) and XMA (250 μg/mL) for 48 h. Sprague-Dawley rats were randomly grouped into eight groups ( = 8 per group): (I) control group received saline; (II) MCT group received MCT (60 mg/kg); (III) SIL-Low group received MCT + SIL at 10 mg/kg/day; (IV) SIL-high group received MCT + SIL at 30 mg/kg/day; (V) XMA-High group received MCT + XMA at 251.6 mg/kg/day; (VI) SIL (Low)+XMA (Low) group received SIL (10 mg/kg) + XMA at 62.9 mg/kg/day; (VII) SIL (Low)+XMA (Medium) group received SIL (10 mg/kg) + XMA at 125.8 mg/kg/day; (VIII) SIL (Low)+XMA (High) group received SIL (10 mg/kg) + XMA at 251.6 mg/kg/day. Both XMA and SIL were given by gavage and were maintained daily for 2 weeks.

Results: XMA could improve SIL's efficacy in the treatment of PAH by decreasing cell viability more effectively at non-cytotoxic concentrations (250 μg/mL) and reducing Right Ventricular Systolic Pressure (RVSP) in PAH rat. Potential mechanisms might at least in part be through activating the MAPK signalling pathway.

Discussion And Conclusions: The combination of XMA and SIL can improve the efficacy of pulmonary hypertension and reduce the dosage of SIL.
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http://dx.doi.org/10.1080/13880209.2021.1917629DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8143608PMC
December 2021

Therapeutic Mechanism and Effect of Camptothecin on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice.

J Immunol Res 2021 24;2021:5556659. Epub 2021 Apr 24.

Department of Gastrointestinal Colorectal and Anal Surgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China.

Camptothecin (CPT) is a cytotoxic quinoline alkaloid isolated from the bark and branches of the Chinese tree . CPT inhibits topoisomerase I. It possesses various antitumor activities and is mainly used in the treatment of colon, ovarian, liver, and bone cancers as well as leukemia. CPT inhibits the expressions of inflammatory genes and can prevent death from chronic inflammation. Therefore, we investigated the effect of CPT treatment in ulcerative colitis (UC) using DSS-induced UC mouse model; after that, we explored its potential mechanisms. Here, we found that CPT exerted protection on DSS-induced UC in rats. In addition, the administration prominently reduced the disease activity index as well as colon length of the model rats and remarkably reduced the inflammatory cytokines. Further, CPT significantly reduced several vital proinflammatory proteins in LPS-induced RAW264.7 cells. In summary, our findings demonstrate that CPT is hopefully to act as a therapeutic agent for UC.
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http://dx.doi.org/10.1155/2021/5556659DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093050PMC
November 2021

A Dual-Mode 2D Matrix Array for Ultrasound Image-Guided Noninvasive Therapy.

IEEE Trans Biomed Eng 2021 12 19;68(12):3482-3490. Epub 2021 Nov 19.

Focused ultrasound (FUS) lacks reliable real-time image guidance, which hinders the development of non-invasive ultrasound treatment in many important clinical applications. A dual-mode ultrasound array, capable of both imaging and therapy offers a new and reliable strategy for image-guided ultrasound therapy applications. The strategy has the advantages of real-time use, low cost, portability and inherent registration between imaging and therapeutic coordinate systems. In this work, a dual-mode two-dimensional (2D) matrix array with 1 MHz center frequency and 256 elements for ultrasound image-guided non-invasive therapy is reported. The array can provide three-dimensional (3D) volumetric ultrasound imaging and 3D focus control. Ultrasound imaging and therapeutic applications for the brain of small animals demonstrated the multi-functional capability of the dual-mode 2D matrix array. A method of rat brain positioning based on ultrasound imaging was proposed and verified. Transcranial ultrasound image-guided blood-brain barrier (BBB) opening of multiple-targets was achieved in vivo, using the proposed dual-mode 2D array. The obtained results indicate that the dual-mode 2D matrix array is a promising method for practical use in ultrasound image-guided non-invasive therapy applications.
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http://dx.doi.org/10.1109/TBME.2021.3073951DOI Listing
December 2021

Poly(amino acid)s-based star AIEgens for cell uptake with pH-response and chiral difference.

Colloids Surf B Biointerfaces 2021 Jun 9;202:111687. Epub 2021 Mar 9.

Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China. Electronic address:

Chiral aggregation-induced emission luminogens (AIEgens) are the new-generation chiral sensors that regulate chiral signals from the molecular level to the macroscopic assembly. Expanding applications of chiral AIEgens and in-depth understanding of their chiral recognition in biological systems are meaningful. Herein, two star chiral AIEgens, consisting of tetraphenylethene (TPE) as core and poly(N-acryloyl-L(D) valine) (PLV or PDV) as arms, were precisely synthesized via atom transfer radical polymerization (ATRP) technique and named TPE-PLV and TPE-PDV. They possessed typical AIE characteristics and exhibited an increase in concentration-dependent fluorescence intensity. The two AIEgens were pH-responsive and had strong AIE-related emission in acidic solution. Importantly, AIEgens can enter the living cells by ATP dependent endocytosis, then light them up. The interactions between the AIEgens and living human hepatocarcinoma (HepG2) cells revealed that the internalization process of TPE-PLV and TPE-PDV was both chiral-dependent and pH-responsive. This novel strategy for synthesizing poly(amino acid)s functionalized AIEgens could inspire the development of promising fluorescent materials with chirality.
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http://dx.doi.org/10.1016/j.colsurfb.2021.111687DOI Listing
June 2021

In vitro model insights into the role of human gut microbiota on arsenic bioaccessibility and its speciation in soils.

Environ Pollut 2020 Aug 16;263(Pt A):114580. Epub 2020 Apr 16.

State Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China. Electronic address:

The bioaccessibility of arsenic and its speciation are two important factors in assessing human health risks exposure to contaminated soils. However, the effects of human gut microbiota on arsenic bioaccessibility and its speciation are not well characterized. In this study, an improved in vitro model was utilized to investigate the bioaccessibility of arsenic in the digestive tract and the role of human gut microbiota in the regulation of arsenic speciation. For all soils, arsenic bioaccessibility from the combined in vitro model showed that it was <40% in the gastric, small intestinal and colon phases. This finding demonstrated that the common bioaccessibility approach assuming 100% bioaccessibility would overestimate the human health risks posed by contaminated soils. Further to this, the study showed that arsenic bioaccessibility was 22% higher in the active colon phase than that in the sterile colon phase indicating that human colon microorganisms could induce arsenic release from the solid phase. Only inorganic arsenic was detected in the gastric and small intestinal phases, with arsenate [As(V)] being the dominant arsenic species (74%-87% of total arsenic). Arsenic speciation was significantly altered by the active colon microbiota, which resulted in the formation of methylated arsenic species, including monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)] with low toxicity, and a highly toxic arsenic species monomethylarsonous acid [MMA(III)]. Additionally, a high level of monomethylmonothioarsonic acid [MMMTA(V)] (up to 17% of total arsenic in the extraction solution) with unknown toxicological properties was also detected in the active colon phase. The formation of various organic arsenic species demonstrated that human colon microorganisms could actively metabolize inorganic arsenic into methylated arsenicals and methylated thioarsenicals. Such transformation should be considered when assessing the human health risks associated with oral exposure to soil.
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http://dx.doi.org/10.1016/j.envpol.2020.114580DOI Listing
August 2020

Transcranial Focused Ultrasound Stimulation Improves Neurorehabilitation after Middle Cerebral Artery Occlusion in Mice.

Aging Dis 2021 Feb 1;12(1):50-60. Epub 2021 Feb 1.

2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.

Transcranial focused ultrasound stimulation (tFUS) regulates neural activity in different brain regions in humans and animals. However, the role of ultrasound stimulation in modulating neural activity and promoting neurorehabilitation in the ischemic brain is largely unknown. In the present study, we explored the effect of tFUS on neurological rehabilitation and the underlying mechanism. Adult male ICR mice (n=42) underwent transient middle cerebral artery occlusion. One week after brain ischemia, low frequency (0.5 MHz) tFUS was applied to stimulate the ischemic hemisphere of mice for 7 consecutive days (10 minutes daily). Brain infarct volume, neurobehavioral tests, microglia activation, IL-10 and IL-10R levels were further assessed for up to 14 days. We found that the brain infarct volume was significantly reduced in the tFUS treated mice compared to that in the non-treated mice (<0.05). Similarly, neurological severity scores, elevated body swing test, and corner test improved in the tFUS treated mice (<0.05). We also demonstrated that tFUS resulted in increased M2 microglia in the ischemic brain region. The expression of IL-10R and IL-10 levels were also substantially upregulated (<0.05). We concluded that tFUS served as a unique technique to promote neurorehabilitation after brain ischemia by promoting microglia polarization and further regulating IL-10 signaling in the ischemic brain.
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http://dx.doi.org/10.14336/AD.2020.0623DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7801287PMC
February 2021

Copper-catalyzed radical cascade cyclization for synthesis of CF-containing tetracyclic benzimidazo[2,1-]iso-quinolin-6(5)-ones.

Org Biomol Chem 2021 01;19(2):375-378

School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, P. R. China.

Here, a general copper-catalyzed radical cascade carbocyclization reaction with 2-arylbenzoimidazoles and a Togni reagent was realized. Structurally diverse CF3-containing tetracyclic core benzimidazo[2,1-a]isoquinoline-6(5H)-ones were obtained in moderate to good yields. The wide substrate scope, good functional group tolerance, and ease of scale-up of this method are expected to promote its potential applications in pharmacy and biotechnology.
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http://dx.doi.org/10.1039/d0ob02210aDOI Listing
January 2021

Synthetic methods for compounds containing fluoro-lactam units.

Org Biomol Chem 2020 Dec 25;18(48):9762-9774. Epub 2020 Nov 25.

School of Chemistry and Chemical Engineering, YanTai University, Yantai, 264005, Shandong, P. R. China.

In recent years, considerable attention has been devoted to the exploration of novel synthetic methods for fluoro-lactams due to their significant biological and pharmaceutical activities. This review summarizes recently established strategies for synthesizing fluorine-substituted lactams, including fluoro-β-lactams, fluoro-γ-lactams, and fluoro-δ-lactams. Additionally, the reaction scopes, limitations, and mechanisms are discussed.
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http://dx.doi.org/10.1039/d0ob02168gDOI Listing
December 2020

The protective effect and mechanism of pedunculoside on DSS (dextran sulfate sodium) induced ulcerative colitis in mice.

Int Immunopharmacol 2020 Nov 22;88:107017. Epub 2020 Sep 22.

College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130117, China.

Pedunculoside (PE) is derived from the bark of iron holly, a member of the holly family. Previous studies have shown that PE has anti-inflammatory, antitumor, antiviral, cholesterol-lowering and blood-pressure-lowering effects. In this study, we aimed to investigate the effects of PE on ulcerative colitis and to explore its potential mechanisms. We treated a mouse model of ulcerative colitis induced by DSS (dextran sulfate sodium) with PE. The results showed that PE had an obvious effect on DSS-induced ulcerative colitis. PE significantly improved the colon length and clinical score in mice, and significantly inhibited the production of inflammatory cytokines. In the LPS-induced inflammatory response of RAW264.7 macrophages, we also found that PE significantly inhibited the phosphorylation of AKT, ERK1/2, JNK1/2, P65, and P38 to reduce the production of IL-1β, IL-6, TNF-α, COX-2, and iNOS. Furthermore, PE suppressed the LPS-induced transcriptional activities of nuclear factor P65 as well as the phosphorylation of P65. In addition, we also studied the effect of PE on LPS induced AKT/NF-κB and MAPK signaling pathways with primary peritoneal macrophages. In summary, PE has a beneficial effect on ulcerative colitis, and may be a potential natural product in the treatment of ulcerative colitis.
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http://dx.doi.org/10.1016/j.intimp.2020.107017DOI Listing
November 2020

1,3-Dipolar Cycloaddition between Dehydroalanines and C,N-Cyclic Azomethine Imines: Application to Late-Stage Peptide Modification.

Angew Chem Int Ed Engl 2021 03 18;60(10):5331-5338. Epub 2021 Jan 18.

School of Life Sciences, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences & Research Unit of Peptide Science, Chinese Academy of Medical Sciences, 2019RU066, Lanzhou University, 199 West Donggang Rd, Lanzhou, 730000, Gansu, P. R. China.

A non-catalytic, mild, and easy-to-handle protecting group switched 1,3-dipolar cycloaddition (1,3-DC) between bi- or mono-N-protected Dha and C,N-cyclic azomethine imines, which afford various quaternary amino acids with diverse scaffolds, is disclosed. Specifically, normal-electron-demand 1,3-DC reaction occurs between bi-N-protected Dha and C,N-cyclic azomethine imines, while inverse-electron-demand 1,3-DC reaction occurs between mono-N-protected Dha and C,N-cyclic azomethine imines. Above all, the reactions can be carried out between peptides with Dha residues at the position of interest and C,N-cyclic azomethine imines, both in homogeneous phase and on resins in SPPS. It provides a new toolkit for late-stage peptide modification, labeling, and peptide-drug conjugation. To shed light on the high regioselectivity of the reaction, DFT calculations were carried out, which were qualitatively consistent with the experimental observations.
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http://dx.doi.org/10.1002/anie.202012523DOI Listing
March 2021

The association between maternal exposure to secondhand smoke during pregnancy and their children's cerebral palsy, Shandong, China.

Tob Induc Dis 2020 21;18:87. Epub 2020 Oct 21.

School of Medicine, Shandong University, Jinan, People's Republic of China.

Introduction: Tobacco use poses a threat to the health of pregnant women and their children. Our study assessed the association between maternal exposure to secondhand smoke (SHS) during pregnancy and children's cerebral palsy (CP) in Shandong, China.

Methods: In our observational study, 5067 mother-child pairs were included from Shandong Province, China. Mothers filled in questionnaires about exposure to SHS during pregnancy. Statistical analysis and logistic regression models were built in R program to estimate the association in adjusted odds ratio (AOR) between SHS exposure during pregnancy and risk of children's CP, after adjustment for potential confounders including delivery mode and baby's birthweight.

Results: Exposure to SHS was noted among 3663 (72.3%) of the 5067 non-smoking mothers during their pregnancy. Of the 239 CP children within the study, 192 (80.3%) were exposed to SHS during pregnancy. Children born to mothers exposed to SHS during pregnancy had a higher risk of CP (AOR=1.44; 95% CI: 1.02-2.04) than those born to non-exposed mothers, the risk increased by exposure time in the logistic regression model. The association between SHS exposure during pregnancy and CP children remained significant when adjusting for delivery mode and infant's birthweight due to their significant association with CP, with an AOR of 1.46 (95% CI: 1.13-1.91) for 1-4 days/week and 1.63 (95% CI: 1.22-2.01) for 5-7 days/week exposure to SHS.

Conclusions: Our study suggests that maternal exposure to secondhand smoke during pregnancy is associated with children's CP. Future preventive interventions of CP should include strategies that target the antenatal women who are exposed to SHS.
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http://dx.doi.org/10.18332/tid/127872DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7592196PMC
October 2020

Curative Effect and Mechanism of Guiren Runchang Granules on Morphine-Induced Slow Transit Constipation in Mice.

Evid Based Complement Alternat Med 2020 23;2020:5493192. Epub 2020 Sep 23.

Anorectal Department, Affiliated Hospital of Changchun University of TCM, Changchun, Jilin 130021, China.

Recent studies have identified the curative effects of traditional Chinese medicine for constipation. The mechanism of action of Guiren Runchang granules (GRGs) in the treatment of slow transit constipation (STC) was evaluated in this study. Here, we assessed the efficacy of GRG by comparing the differences in fecal characteristics, stool weight, and intestinal transit rate (ITR) among 6 groups ( = 12/group), which were administered three concentrations of GRG, mosapride, and saline. The influence of GRG on the SCF/c-kit pathway, AQP4, and serum motilin of mice was assessed through ELISA, western blot, and immunohistochemical analysis. The dry weight of mouse feces at 24 hr and ITR in the MD (medium-dose GRG; 9.44 g/kg/d) and HD (high-dose GRG; 18.88 g/kg/d) groups was higher than that in the MC (model control) group. The serum motilin of morphine-induced mice level was lower in the MC group than in the NC (normal control) group, and this condition was improved in the HD group. The HD group expressed significantly higher levels of SCF and c-kit protein but lower levels of AQP4 and simultaneously presented more SCF-positive and c-kit-positive cells. However, no differences in the serum SCF level were found among the six groups. Certain concentrations of GRG are effective in STC mice, the potential mechanism of which may be associated with repairing the SCF/c-kit pathway and reducing the expression of AQP4 in the colon. GRG improved the serum motilin level but had no influence on the serum SCF level.
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http://dx.doi.org/10.1155/2020/5493192DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7530485PMC
September 2020

Development of a novel prognostic score combining clinicopathologic variables, gene expression, and mutation profiles for lung adenocarcinoma.

World J Surg Oncol 2020 Sep 19;18(1):249. Epub 2020 Sep 19.

Department of Thoracic Surgery, Shenzhen People's Hospital, Second Clinical Medical College of Jinan University, Luohu District, Shenzhen, 518020, China.

Background: Integrating phenotypic and genotypic information to improve prognostic prediction is under active investigation for lung adenocarcinoma (LUAD). In this study, we developed a new prognostic model for event-free survival (EFS) and recurrence-free survival (RFS) based on the combination of clinicopathologic variables, gene expression, and mutation data.

Methods: We enrolled a total of 408 patients from the Cancer Genome Atlas Lung Adenocarcinoma (TCGA-LUAD) project for the study. We pre-selected gene expression or mutation features and constructed 14 different input feature sets for predictive model development. We assessed model performance with multiple evaluation metrics including the distribution of C-index on testing dataset, risk score significance, and time-dependent AUC under competing risks scenario. We stratified patients into higher- and lower-risk subgroups by the final risk score and further investigated underlying immune phenotyping variations associated with the differential risk.

Results: The model integrating all three types of data achieved the best prediction performance. The resultant risk score provided a higher-resolution risk stratification than other models within pathologically defined subgroups. The score could account for extra EFS-related variations that were not captured by clinicopathologic scores. Being validated for RFS prediction under a competing risks modeling framework, the score achieved a significantly higher time-dependent AUC as compared to that of the conventional clinicopathologic variables-based model (0.772 vs. 0.646, p value < 0.001). The higher-risk patients were characterized with transcriptional aberrations of multiple immune-related genes, and a significant depletion of mast cells and natural killer cells.

Conclusions: We developed a novel prognostic risk score with improved prediction accuracy, using clinicopathologic variables, gene expression and mutation profiles as input, for LUAD. Such score was a significant predictor of both EFS and RFS.

Trial Registration: This study was based on public open data from TCGA and hence the study objects were retrospectively registered.
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http://dx.doi.org/10.1186/s12957-020-02025-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7502202PMC
September 2020

A Highly Magnetic Field Sensitive Photonic Crystal Fiber Based on Surface Plasmon Resonance.

Sensors (Basel) 2020 Sep 11;20(18). Epub 2020 Sep 11.

Center of Material Science, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha 410073, China.

A novel magnetic field sensor comprising a photonic crystal fiber (PCF) is designed and investigated based on surface plasmon resonance (SPR). We use finite element analysis in order to analyze the sensing characteristics of the magnetic field sensor. The simulation results show that the sensor is very sensitive to the change of refractive index and has good linearity in the refractive index range from 1.43-1.45. The thickness of the metal film and the metal material has great influence on the resonance wavelength and the peak of the loss spectrum, the diameter of the central air hole will affect SPP excitation. When the thickness of gold layer is 50 nm, the refractive index sensitivity is 4125 nm/RIU in the refractive index range from 1.43-1.45. Using the designed sensor for magnetic field sensing, the loss spectrum is red-shifted with the increase of the magnetic field, the highest magnetic field sensitivity can reach 61.25 pm/Oe in the range from 50 Oe to 130 Oe. The sensor not only has high sensitivity of refractive index, but it can also realize accurate measurement of magnetic field. It has huge application potential in complex environment, remote sensing, real-time monitoring, and other fields.
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http://dx.doi.org/10.3390/s20185193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7570832PMC
September 2020

The effect of traditional Tibetan guozhuang dance on vascular health in elderly individuals living at high altitudes.

Am J Transl Res 2020 15;12(8):4550-4560. Epub 2020 Aug 15.

Institute of Geriatric, Qinghai Provincial People's Hospital Xining, People's Republic of China.

To evaluate the effect of dance on vascular-related factors and cerebral hemodynamics in elderly individuals in Qinghai-Tibetan plateau regions (mean altitude ≥2,300 m). Thirty elderly individuals, who practiced traditional Tibetan Guozhuang dance or did not, were enrolled, respectively. Serum PGC-1α, HCY, FSTL-1, VEGF and HIF-1α were measured by ELISA assays. Carotid artery stenosis and plaque, IMT, extracranial internal carotid artery stenosis and cerebral arteriosclerosis were evaluated using CUS and TCD. Body weight, BMI, heart rate, systolic pressure, and diastolic pressure, serum BGS, TC, LDL, HIF-1α, VEGF, and HCY in the dance group were significantly lower than the no-dance group. FSTL-1 levels, SO and SO/heart rate ratio in the dance group were significantly higher than the no-dance group. Incidence of extracranial internal carotid artery stenosis, carotid stenosis and plaque in the dance group was significantly lower than the no-dance group. IMT was a significant positive correlation between PGC-1α and HCY in the no-dance group. Elderly individuals who regularly practiced Tibetan dance had improved blood vessel functionality and cerebral hemodynamic at high altitudes.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7476110PMC
August 2020

Dual Targeting of Cell Growth and Phagocytosis by Erianin for Human Colorectal Cancer.

Drug Des Devel Ther 2020 12;14:3301-3313. Epub 2020 Aug 12.

School of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun 130117, People's Republic of China.

Objective: To investigate the effect of erianin on tumor growth and immune response in human colorectal cancer cells (CRC).

Methods: The effect of erianin on tumor growth was determined by CCK8 and colony formation assay. Western blotting was used to evaluate the expression levels of relevant proteins and qRT-PCR was used to evaluate the mRNA level of the relevant gene. The transcriptional activity of β-catenin was determined by dual-luciferase reporter assay. Cellular thermal shift assay was used to quantify drug-target interactions. The cell surface CD47 was assessed by flow cytometry. The enrichment of H3K27 acetyl marks on CD47 promoter was evaluated by chromatin immunoprecipitation assay. Phagocytosis assay was used to determine the phagocytic activity of macrophage. In vivo role of erianin was studied on xenograft models.

Results: We found that erianin significantly decreased cell survival, colony formation, induced cell cycle arrest, and led to cell apoptosis in SW480 and HCT116 cells. Mechanism analysis demonstrated that erianin inhibited the nuclear translocation and transcriptional activity of β-catenin, which might result from erianin-β-catenin interaction. In addition, the downstream gene expressions, such as c-Myc and cyclin D1, was decreased. More interestingly, erianin decreased the expression of CD47 by regulating H3K27 acetyl marks enrichment on CD47 promoter. Consequently, macrophage-mediated phagocytosis was increased. Our in vivo experiments further confirmed the inhibitory effect of erianin on tumor growth.

Conclusion: In summary, erianin could inhibit CRC cells growth and promoted phagocytosis, which suggested erianin as a potential therapeutic strategy for CRC patients.
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http://dx.doi.org/10.2147/DDDT.S259006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7429191PMC
July 2021

Double Electromagnetically Induced Transparency and Its Slow Light Application Based On a Guided-Mode Resonance Grating Cascade Structure.

Materials (Basel) 2020 Aug 21;13(17). Epub 2020 Aug 21.

Center of Material Science, National University of Defense Technology, Changsha 410073, China.

In recent years, the achievement of the electromagnetically induced transparency (EIT) effect based on the guided-mode resonance (GMR) effect has attracted extensive attention. However, few works have achieved a double EIT-like effect using this method. In this paper, we numerically achieve a double EIT-like effect in a GMR system with a three-layer silicon nitride waveguide grating structure (WGS), using the multi-level atomic system model for theoretical explanation. In terms of slow light performance, the corresponding two delay times reach 22.59 ps and 8.43 ps, respectively. We also investigate the influence of wavelength detuning of different GMR modes on the transparent window and slow light performance. Furthermore, a wide-band flat-top transparent window was also achieved by appropriately adjusting the wavelength detuning between GMR modes. These results indicate that the EIT-like effect in the WGS has potential application prospects in low-loss slow optical devices, optical sensing, and optical communications.
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http://dx.doi.org/10.3390/ma13173710DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7503817PMC
August 2020

Dynamic surface properties and dilational rheology of acidic and lactonic sophorolipids at the air-water interface.

Colloids Surf B Biointerfaces 2020 Nov 7;195:111248. Epub 2020 Jul 7.

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology), Chengdu, Sichuan Province 610059, China; College of Energy, Chengdu University of Technology, Chengdu, Sichuan Province 610059, China; Petro-Engineering Research Institute of North China Oil and Gas Branch, Sinopec, Zhengzhou, Henan Province 450006, China.

This study analyzes the equilibrium and dynamic surface tension curves of acidic and lactonic sophorolipids (SLs). It also investigates the dilational properties of the surface adsorptive film. Given their high hydrophobicity, lactonic SLs have lower surface tension and critical micelle concentration (CMC) than acidic SLs. As c increases, the CMC values and the corresponding surface tension (γ) of acidic and lactonic SLs decrease gradually. For dynamic surface properties, lactonic SLs have a high diffusive rate from the bulk phase to the subsurface. At 0.05 CMC, the initial adsorption of acidic and lactonic SLs is diffusion-controlled. As c increases, the values of diffusion coefficient (D) show a downward trend, and the mechanism is mixed kinetic diffusion. Adding NaCl increases the D values of acidic and lactonic SLs, and the influence degree for acidic SLs is more considerable than that for lactonic SLs. As frequency (ω) increases (0.005∼0.5 Hz), the dilational elasticity increases, and the phase angle decrease. The dilational elasticity of acidic and lactonic SLs shows a low-frequency dependence. Compared with acidic SLs, lactonic SLs have better dynamic surface properties, which decrease the gradient of interfacial tension because of the interface deformation. Consequently, the lactonic SLs exhibit a relatively small dilational elasticity. At 0.1 Hz, the dilational elasticity of acidic and lactonic SLs reaches the maximum values at 0.05CMC and 0.075CMC, respectively. When c rises near CMC, the phase angle increases obviously, and the dilational elasticity further decreases. This result is attributed to the fast exchange of surfactant molecules between the interface and the micelles.
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http://dx.doi.org/10.1016/j.colsurfb.2020.111248DOI Listing
November 2020

A Practical EEG-Based Human-Machine Interface to Online Control an Upper-Limb Assist Robot.

Front Neurorobot 2020 10;14:32. Epub 2020 Jul 10.

Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou, China.

Electroencephalography (EEG) can be used to control machines with human intention, especially for paralyzed people in rehabilitation exercises or daily activities. Some effort was put into this but still not enough for online use. To improve the practicality, this study aims to propose an efficient control method based on P300, a special EEG component. Moreover, we have developed an upper-limb assist robot system with the method for verification and hope to really help paralyzed people. We chose P300, which is highly available and easily accepted to obtain the user's intention. Preprocessing and spatial enhancement were firstly implemented on raw EEG data. Then, three approaches- linear discriminant analysis, support vector machine, and multilayer perceptron -were compared in detail to accomplish an efficient P300 detector, whose output was employed as a command to control the assist robot. The method we proposed achieved an accuracy of 94.43% in the offline test with the data from eight participants. It showed sufficient reliability and robustness with an accuracy of 80.83% and an information transfer rate of 15.42 in the online test. Furthermore, the extended test showed remarkable generalizability of this method that can be used in more complex application scenarios. From the results, we can see that the proposed method has great potential for helping paralyzed people easily control an assist robot to do numbers of things.
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http://dx.doi.org/10.3389/fnbot.2020.00032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7366778PMC
July 2020

Ultra-compact high efficiency and low crosstalk optical interconnection structures based on inverse designed nanophotonic elements.

Sci Rep 2020 Jul 20;10(1):11993. Epub 2020 Jul 20.

Guangxi Key Laboratory of Multimedia Communications and Network Technology, School of Computer, Electronics and Information, Guangxi University, Nanning, 530004, China.

In this paper, we combine inverse design concept and direct binary search algorithm to demonstrate three ultra-compact high efficiency and low crosstalk on-chip integrated optical interconnection basic devices in the entire wavelength range of 1,400-1600 nm based on silicon-on-insulator platform. A 90-degree waveguide bend with a footprint of only 2.4 × 2.4 μm is designed, whose transmission efficiency up to 0.18 dB. A waveguide crossing with a footprint of only 2.4 × 2.4 μm is designed, which can provide insertion loss of less than 0.5 dB and crosstalk (CL) of lower than - 19 dB. A same direction waveguide crossing with footprint of only 2.4 × 3.6 μm is designed, which can provide the insertion loss of less than 0.56 dB and the crosstalk of lower than - 21 dB. Then, we use them to form several ultra-compact optical interconnect basic structures and performed the simulation calculation. They overall achieve high performance. This will significantly improve the integration density.
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http://dx.doi.org/10.1038/s41598-020-68936-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7371873PMC
July 2020

MicroRNA-4500 Inhibits Migration, Invasion, and Angiogenesis of Breast Cancer Cells via RRM2-Dependent MAPK Signaling Pathway.

Mol Ther Nucleic Acids 2020 Sep 4;21:278-289. Epub 2020 May 4.

Department of Breast Surgery, Shenzhen Maternity and Child Health Hospital, Shenzhen 518000, P.R. China.

With the consideration of the dynamic role of microRNAs (miRNAs) in breast cancer, miRNAs may serve as therapeutic targets, helping to prevent development of therapy resistance, maintain stable disease, and prohibit metastatic spread. We identified the differentially expressed breast cancer-related gene ribonucleotide reductase subunit M2 (RRM2) as the study focus through microarray expression profiles. Next, the upstream regulatory microRNA (miR)-4500 of RRM2 was predicted using bioinformatics website analysis, and their binding was verified by a dual luciferase reporter gene assay. The regulatory effects of miR-4500 on breast cancer cell proliferation, apoptosis, migration, invasion, and capillary-like tube formation of endothelial cells were assessed by gain- and loss-of-function experiments. The experimental data revealed that miR-4500 was downregulated, whereas RRM2 was upregulated in breast cancer cells. Mechanistic analysis revealed that miR-4500 downregulated the RRM2 expression to inactivate the mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, miR-4500 exerted anti-tumor effects by targeting RRM2 through suppression of the MAPK signaling pathway in vitro, evidenced by attenuated cancer cell migration and invasion and capillary-like tube formation of endothelial cells. The in vivo experiments further corroborated in vitro results. Collectively, overexpressed miR-4500 could downregulate RRM2 and inhibit activation of the MAPK signaling pathway, thus attenuating breast cancer cell proliferation, invasion, migration, and angiogenesis and promoting breast cancer cell apoptosis.
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http://dx.doi.org/10.1016/j.omtn.2020.04.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7330432PMC
September 2020

Silibinin suppresses epithelial-mesenchymal transition in human non-small cell lung cancer cells by restraining RHBDD1.

Cell Mol Biol Lett 2020 9;25:36. Epub 2020 Jun 9.

Department of Pharmacy, Henan Provincial People Hospital, Department of Pharmacy of Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, 450003 Henan China.

Background: Rhomboid domain containing 1 (RHBDD1) plays a crucial role in tumorigenesis. Silibinin, which is a natural extract from milk thistle, has shown anti-tumor effects against various tumors. Here, we investigate whether silibinin affects the function of RHBDD1 in non-small cell lung cancer (NSCLC) cell proliferation, migration and invasion.

Methods: The Oncomine database and an immunohistochemistry (IHC) assay were used to determine the RHBDD1 expression levels in lung cancer tissues. The associations between RHBDD1 and overall survival rate or clinicopathological parameters were respectively assessed using the Kaplan-Meier overall survival analysis or Chi-squared test. CCK-8 and Transwell assays were applied to analyze cell proliferation, migration and invasion. A549 cells were incubated with increasing concentrations of silibinin. RHBDD1 knockdown and overexpression were achieved via transfection with si-RHBDD1 or RHBDD1 overexpression plasmid, respectively. Western blotting was performed to measure the expressions of epithelial-mesenchymal transition (EMT) markers.

Results: We found that overexpression of RHBDD1 in lung cancer tissues correlates with a poor prognosis of survival. Clinical specimen analysis showed that upregulation of RHBDD1 correlates remarkably well with TNM stage and lymph node metastasis. Silibinin suppresses A549 cell proliferation, migration, invasion and EMT in a dose-dependent manner. Importantly, RHBDD1 was downregulated in silibinin-treated A549 cells. RHBDD1 overexpression reversed the suppressive effects of silibinin on A549 cell proliferation, migration, invasion and EMT expression, while its knockdown enhanced them.

Conclusions: These findings shown an anti-tumor impact of silibinin on NSCLC cells via repression of RHBDD1.
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http://dx.doi.org/10.1186/s11658-020-00229-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7285460PMC
February 2021

Glycyrrhizin improved autophagy flux via HMGB1-dependent Akt/mTOR signaling pathway to prevent Doxorubicin-induced cardiotoxicity.

Toxicology 2020 08 7;441:152508. Epub 2020 Jun 7.

Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Rational Medication Evaluation and Drug Delivery Technology Lab, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China; Guangdong Key Laboratory of new drug screening, Southern Medical University, Guangzhou 510515, China. Electronic address:

Doxorubicin (DOX) is one of the most effective and irreplaceable chemotherapeutic agents but its clinical use is limited due to its cardiotoxicity. Glycyrrhizin(GL) has been applied to liver disorders for long. However, little is known that if GL could be meaningful in attenuating cardiotoxicity. The aim of this study is to investigate the cardioprotective effects of GL in DOX-induced cardiotoxicity (DIC) and the underlying mechanism. Here, H9c2 cardiomyoblasts, Neonatal rat cardiomyocytes (NRCMs), and Rats were introduced as test models. A single dose of 20 mg/kg DOX (i.p.) was applied to induce acute cardiotoxicity in vivo, as reflected by growth inhibition, increased levels of AST and CK-MB, and reduction of SOD activity, while GL (25 or 50 mg/kg/d, 14 d, i.p.) could counteract these effects. Moreover, pre-incubation with GL (0.8 mM for 12 h) in H9c2 cells protected against DOX-induced cytotoxicity, oxidative stress and depolarization of mitochondrial membrane potential (MMP). Besides, Western blot analysis showed that DOX upregulated the expression of LC3 II and p62 whereas GL reversed that both in vitro and in vivo and improved the obstructed autophagy flux in DOX-treated H9c2 cells with an autophagy inhibitor Bafilomycin A1 (Baf A1, 50 nM, 2 h). It has been previously documented that High-mobility group box 1 (HMGB1) was involved in DIC. In our work, knockdown of HMGB1 significantly increased cell viability and LC3 II level in H9c2, suggesting HMGB1 was crucial in DOX-induced autophagy-triggering cell death. Intriguingly, GL is a direct inhibitor of HMGB1. We found that GL downregulated Akt/mTOR autophagy signaling pathway in DOX-treated H9c2 cells. More importantly, in non-silencing H9c2 cells (transfected with negative control siRNA) cells, the expression of phospho-Akt, phospho-mTOR, p62, and LC3 II was significantly decreased with GL pretreament compared to DOX alone. However, in H9c2/HMGB1(transfected with HMGB1 siRNA) cells exposed to DOX, the expression of p-Akt, p-mTOR, p62, LC3 II had no statistical difference with or without GL, revealing that HMGB1 mediated the cardioprotective action of GL in DIC. Taken together, our findings demonstrate that improved autophagy flux via HMGB1-dependent Akt/mTOR signaling pathway might contribute to attenuate DIC and go a novel insight into the underlying mechanisms of GL's cardioprotective action. GL could be a potential candidate for the prevention of DIC.
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http://dx.doi.org/10.1016/j.tox.2020.152508DOI Listing
August 2020

DEC1 directly interacts with estrogen receptor (ER) α to suppress proliferation of ER-positive breast cancer cells.

Biochem Biophys Res Commun 2020 08 7;528(4):740-745. Epub 2020 Jun 7.

School of Medical Technolog, Qiqihar Medical University, Qiqihar, Heilongjiang, China. Electronic address:

Aberrant ERα signaling and altered circadian rhythms are both features of ER-positive breast cancer, however, the molecular interaction between them is still not fully understood. Herein, we analyzed the interplay between the circadian rhythm molecule DEC1 and ERα and its effect on the proliferation of ER-positive breast cancer cells, providing a new clue for clarifying the pathogenesis of breast cancer. In this study, we revealed that DEC1 negatively regulates the proliferation of ER-positive breast cancer MCF-7 cells through interaction with ERα protein. DEC1 co-localized with ERα in the nucleus of MCF7 cells, stabilized ERα protein independently of its transcriptional activity and without affecting by estrogen stimulation and inhibited the degradation of ERα mediated by CHX in a time-dependent manner. Moreover, results from luciferase reporter assay showed that overexpression of DEC1 significantly inhibits ERα-mediated transcriptional activity in a dose-dependent manner. These results together suggested that DEC1 may serve as a co-repressor of ERα in ER-positive breast cancer. Although DEC1 improved the stability of ERα and alleviated protein degradation, DEC1 inhibited the proliferation of MCF7 cells by decreasing ERα-mediated signal transduction.
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http://dx.doi.org/10.1016/j.bbrc.2020.05.123DOI Listing
August 2020

[Liquid chromatography tandem mass spectrometry for therapeutic drug monitoring of voriconazole in heat-inactivated blood samples: its application during COVID-19 pandemic].

Nan Fang Yi Ke Da Xue Xue Bao 2020 Mar;40(3):342-345

Department of Pharmacy/Rational Medication Evaluation and Drug Delivery Technology Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.

Objective: To investigate the effect of heat inactivation (56℃for 30 min) of SARS-CoV-2 on the results of therapeuticdrug monitoring (TDM) of voriconazole by liquid chromatography tandem mass spectrometry (LC-MS/MS).

Methods: We collected clinical blood samples from voriconazole-treated patients in heparinized tubes and sterilized the surface of the tubes with 75% ethanol. The whole blood samples were centrifuged to separate the plasma with or without prior heat inactivation, or only the separated plasma was heat inactivated. Heat inactivation of the samples was carried out at 56 ℃ for 30 min followed by protein precipitation with acetonitrile or ethanol. The plasma standard and quality control samples were inactivated in an identical manner and tested with LC-MS/MS along with the treated samples.

Results: The optimized method showed a high imprecision (with mean intra- and inter-day imprecisions of 3.59% and 2.81%, respectively) and a high accuracy (mean 97.37%) for detecting voriconazole in the inactivated samples at different concentration levels. Sample preparation with acetonitrile or ethanol resulted in a high mean recovery (100.56% or 95.90%) with minimal mean matrix effect (102.85% or 93.62%). The measured voriconazole concentrations in inactivated whole blood, inactivated plasma and the samples without inactivation all showed good linear correlations with correlation coefficients all greater than 0.99.

Conclusions: Heat inactivation at 56 ℃ for 30 min combined with ethanol sample preparation only has limited effects to affect LC-MS-based voriconazole concentration measurement in whole blood samples collected in heparinized tubes, and can be used for therapeutic drug monitoring of voriconazole during the ongoing COVID-19 pandemic.
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http://dx.doi.org/10.12122/j.issn.1673-4254.2020.03.08DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7167328PMC
March 2020

Experimental demonstration of broadband impedance matching using coupled electromagnetic resonators.

Sci Rep 2020 May 4;10(1):7437. Epub 2020 May 4.

School of Science, Inner Mongolia University of Science and Technology, Baotou, 014010, China.

Impedance matching is an important factor for the electromagnetic resonators used to construct metasurfaces with perfect absorption and transmission properties. However, these resonators usually exhibit narrowband characteristics, thus greatly restricting their potential for application to metasurfaces to obtain excellent absorption and transmission performances. Therefore, realization of impedance matching over a wider range is of major importance. In this work, we demonstrate broadband impedance matching both theoretically and experimentally through use of coupled inductor-capacitor (LC) resonant coils, which are typical electromagnetic resonators. By adding a third resonant coil into the conventional system composed of two completely mismatched resonant coils, the new system realizes broadband impedance matching when the reflected impedances of the first two coils with respect to the third resonant coil are equal. The results in this work can provide useful guidance for realization of metasurfaces with broadband perfect absorption and transmission constructed using any type of electromagnetic resonator.
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http://dx.doi.org/10.1038/s41598-020-64439-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7198614PMC
May 2020
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