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1.
Phys Rev Lett ; 130(9): 092701, 2023 Mar 03.
Article in English | MEDLINE | ID: mdl-36930937

ABSTRACT

The ^{18}O(α,γ)^{22}Ne reaction is critical for AGB star nucleosynthesis due to its connection to the abundances of several key isotopes, such as ^{21}Ne and ^{22}Ne. However, the ambiguous resonance energy and spin-parity of the dominant 470 keV resonance leads to substantial uncertainty in the ^{18}O(α,γ)^{22}Ne reaction rate for the temperature of interest. We have measured the resonance energies and strengths of the low-energy resonances in ^{18}O(α,γ)^{22}Ne at the Jinping Underground Nuclear Astrophysics experimental facility (JUNA) with improved precision. The key 470 keV resonance energy has been measured to be E_{α}=474.0±1.1 keV, with such high precision achieved for the first time. The spin-parity of this resonance state is determined to be 1^{-}, removing discrepancies in the resonance strengths in earlier studies. The results significantly improve the precision of the ^{18}O(α,γ)^{22}Ne reaction rates by up to about 10 times compared with the previous data at typical AGB temperatures of 0.1-0.3 GK. We demonstrate that such improvement leads to precise ^{21}Ne abundance predictions, with an impact on probing the origin of meteoritic stardust SiC grains from AGB stars.

2.
Zhonghua Jie He He Hu Xi Za Zhi ; 46(7): 688-696, 2023 Jul 12.
Article in Zh | MEDLINE | ID: mdl-37402659

ABSTRACT

Objective: To explore the expression and the role of chemerin in idiopathic pulmonary fibrosis (IPF). Methods: Quantitative PCR and Western blotting were used to determine the mRNA and protein levels of chemerin in lung tissues from IPF patients and the controls. Clinical serum level of chemerin was analyzed by enzyme-linked immunosorbent assay. The mouse lung fibroblasts isolated and cultured in vitro were divided into the control, TGF-ß, TGF-ß+chemerin and chemerin groups. Immunofluorescence staining was used to observe the expression of α-smooth muscle actin (α-SMA). C57BL/6 mice were randomly divided into the control, bleomycin, bleomycin+chemerin, and chemerin groups. Masson and immunohistochemical staining were performed to evaluate the severity of pulmonary fibrosis. Expression of epithelial to mesenchymal transition (EMT) markers was detected by quantitative PCR and immunohistochemical staining in the in vitro and in vivo models of pulmonary fibrosis, respectively. Results: Compared with the control group, the expression of chemerin was downregulated in both the lung tissue and the serum of IPF patients. Immunofluorescence showed that treatment of fibroblasts with TGF-ß alone resulted in a robust expression of α-SMA, whereas treatment with TGF-ß and chemerin together exhibited the similar expression levels of α-SMA as the control group. Masson staining indicated that the bleomycin-induced pulmonary fibrosis model was constructed successfully, while treatment of chemerin partially alleviated the damage of lung tissue. Immunohistochemical staining showed that the expression of chemerin in the lung tissue was significantly decreased in the bleomycin group. Quantitative PCR and immunohistochemistry showed that chemerin attenuated EMT induced by TGF-ß and bleomycin both in vitro and in vivo. Conclusions: The expression of chemerin was reduced in patients with IPF. Chemerin may play a protective role in the development of IPF by regulating EMT, providing a new idea for the clinical treatment of IPF.


Subject(s)
Epithelial-Mesenchymal Transition , Idiopathic Pulmonary Fibrosis , Mice , Animals , Mice, Inbred C57BL , Lung , Idiopathic Pulmonary Fibrosis/metabolism , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta/pharmacology , Bleomycin/metabolism , Bleomycin/pharmacology , Transforming Growth Factor beta1/metabolism , Chemokines/metabolism , Chemokines/pharmacology , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/pharmacology
3.
Phys Rev Lett ; 129(13): 132701, 2022 Sep 23.
Article in English | MEDLINE | ID: mdl-36206440

ABSTRACT

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

4.
Geophys Res Lett ; 49(19): e2022GL098509, 2022 Oct 16.
Article in English | MEDLINE | ID: mdl-36582260

ABSTRACT

Microseismic noise has been used for seismic velocity monitoring. However, such signals are dominated by low-frequency surface waves that are not ideal for detecting changes associated with small tectonic processes. Here we show that it is possible to extract stable, high-frequency body waves using seismic tremors generated by freight trains. Such body waves allow us to focus on small velocity perturbations in the crust with high spatial resolution. We report on 10 years of seismic velocity temporal changes at the San Jacinto Fault. We observe and map a two-month-long episode of velocity changes with complex spatial distribution and interpret the velocity perturbation as produced by a previously undocumented slow-slip event. We verify the hypothesis through numerical simulations and locate this event along a fault segment believed to be locked. Such a slow-slip event stresses its surroundings and may trigger a major earthquake on a fault section approaching failure.

5.
Climacteric ; 25(2): 128-140, 2022 04.
Article in English | MEDLINE | ID: mdl-34346265

ABSTRACT

This systematic review provides an overview of the effects of menopausal symptom treatment options on palpitations, defined as feelings of missed or exaggerated heart beats, reported by perimenopausal and postmenopausal women. Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searches were conducted in PubMed, CINAHL and PsycINFO to identify articles meeting pre-specified inclusion criteria. Of 670 unique articles identified, 37 were included in the review. Treatments included drug therapies and non-drug therapies. Palpitations were studied as an outcome in 89% of articles and as an adverse effect in 11%. Articles provided mostly level II/III evidence due to their design and/or small sample sizes. Based on available evidence, no therapies can be fully recommended for clinical practice. Only some hormonal agents (e.g. estradiol) can be recommended with caution based on some positive evidence for reducing palpitation prevalence or severity. However, other drug therapies (e.g. moxonidine, atenolol), dietary supplementary treatments (e.g. isoflavones, Rheum rhaponticum, sage), cognitive-behavioral intervention and auricular acupressure cannot be recommended given the existing evidence. Additional well-designed randomized controlled treatment trials focusing on palpitations during the menopause transition as an inclusion criteria and outcome are needed to advance the field.


Subject(s)
Cognitive Behavioral Therapy , Isoflavones , Female , Humans , Menopause
6.
Zhonghua Yi Xue Za Zhi ; 102(39): 3134-3142, 2022 Oct 25.
Article in Zh | MEDLINE | ID: mdl-36274598

ABSTRACT

Objective: To observe the lipid metabolism characteristics of tumor-associated macrophages (TAM) after malignant transformation in the glioma micro-environment, and analyze the biological phenotype changes and regulatory mechanisms after inhibiting the lipid metabolism remodeling. Methods: Twelve male Balb/c mice of 6-8 weeks were used in the study. Macrophages (Mφ) were derived from mouse bone marrow, and malignantly transformed macrophages (tMφ1 and tMφ2) were cloned from the model of glioma stem cell (GSC) through interaction with Mφ in vivo and in vitro. Intracellular lipid droplet formation and cellular cholesterol content were measured respectively in Mφ, tMφ1 and tMφ2. qRT-PCR was performed to detect the genes expression level related with lipid metabolism, including sterol regulatory element binding protein (SREBP), fatty acid synthase (FASN), and 3-hydroxy-3-methylglutarate monoacyl coenzyme A reductase (HMG-CoA). Simvastatin (SIM) was used to analyze the proliferation, immigration and invasiveness ability in tMφ1 and tMφ2 after inhibition of the lipid metabolism. Differential expression profiles of miRNAs after SIM treatment were constructed in t-Mφ1 and bio-informatics analysis was screened and verified for miR449a and its target gene sorting micro-tubule connectin 17 (SNX17) associated with lipid metabolism remodeling. The effect on SNX17 by up-regulated miR-449a were analyzed by qRT-PCR and Western blot, meanwhile, the biological phenotype and cholesterol content were observed after up-regulation of miR449a. Low-density lipoprotein receptor (LDLR) protein levels after SNX17 knockdown and intracellular cholesterol content after LDLR knockdown were detected respectively. Results: The numbers of intracellular lipid droplet formation in tMφ1 and tMφ2 were more than that in Mφ (P<0.001). Likewise, the relative contents of cholesterol (3.89±0.68 and 3.56±0.53), SREBP (4.78±0.60 and 2.84±0.41), FASN (4.65±0.70 and 3.01±0.45), and HMG-CoA (5.74±0.55 and 2.97±0.34) were significantly higher in tMφ1 and tMφ2 than those of Mφ (1.01 wel, 1.02 wel and 0.99 wel, respectively) (all P<0.001). The proliferation rates of tMφ1 and tMφ2 decreased from (47.06±5.88) % and (45.29±5.64)% to (23.53±4.70)% and (18.74±5.76)%, respectively after treatment with SIM (both P<0.05). The numbers of migrated cells decreased from 1 025±138 and 350±47 to 205±63 and 99±25, respectively (both P<0.001). And the numbers of invasiveness cells decreased from 919±45 and 527±34 to 220±23 and 114±21, respectively (both P<0.001). While the relative intracellular cholesterol content decreased to 0.52±0.08 and 0.58±0.07 (both P<0.05), respectively. MiR-449a was screened from tMφ1 by SIM, and the target gene was analyzed and verified to be SNX17. SNX17 expression was down-regulated, and the proliferation rate, the number of migration and invasiveness was significantly decreased after miR-449a over-expression (all P<0.05). Low-density lipoprotein receptor (LDLR) expression was down-regulated after knock-down of SNX17, while the cholesterol content was decreased after knock-down of LDLR in tMφ1 and tMφ2 (all P<0.05). Conclusions: Malignantly transformed TAMs undergo lipid metabolism remodeling characterized with enhanced lipid metabolism. MiR-449a regulates the LDLR by targeting SNX17, thereby affecting the lipid metabolism of malignantly transformed macrophages, and subsequently inhibiting its proliferation, migration, and invasion ability. Precise intervention with miR-449a/SNX17/LDLR axis could provide an experimental basis for reversing its tumor-promoting micro-environment remodeled by GSC through metabolic intervention.


Subject(s)
Glioma , MicroRNAs , Mice , Animals , Male , Lipid Metabolism/genetics , Connectin/metabolism , Sterol Regulatory Element Binding Protein 1/genetics , Sterol Regulatory Element Binding Protein 1/metabolism , Cholesterol , Cell Transformation, Neoplastic , MicroRNAs/genetics , Macrophages/metabolism , Fatty Acid Synthases/metabolism , Simvastatin , Oxidoreductases/metabolism , Lipoproteins, LDL/metabolism , Coenzyme A/metabolism , Tumor Microenvironment
7.
Zhonghua Gan Zang Bing Za Zhi ; 30(10): 1074-1081, 2022 Oct 20.
Article in Zh | MEDLINE | ID: mdl-36727232

ABSTRACT

Objective: To explore the effect of MicroRNA 424-5p/Kinesin family member 23(miR-424-5p/KIF23)axis on the malignant phenotype of hepatoma cells and its sensitivity of sorafenib. Methods: Real-time quantitative reverse PCR(qRT-PCR) and/or Western blot were used to detect the expression of miR-424-5p and KIF23 in liver cancer tissues and paracancerous tissues, human hepatocellular carcinoma(HCC) cells HepG2 and normal hepatocyte LO2. HepG2 cells transfected with miR-424-5p mimic and miR-424-5p mimic NC were respectively defined as miR-424-5p mimic group and mimic NC group, HepG2 cells transfected with KIF23 overexpression vector pcDNA3.1-KIF23 or empty vector pcDNA3.1 respectively were defined as OE-KIF23 group and Vector group, and HepG2 cells co-transfected with miR-424-5p mimic and overexpression vector pcDNA3.1-KIF23 were defined as mimic+OE-KIF23 group: The KIF23-3'UTR wild-type vector (KIF23-WT) and the mutant vector (KIF23-MT) were co-transfected with miR-424-5p micic and mimic NC, respectively, and the targeting relationship between miR-424-5p and KIF23 was verified by dual-luciferase reporting experiments. The cell counting Kit-8 (CCK-8) was used to detect HepG2 cell proliferation and sensitivity to sorafenib. Flow cytometry was used to assess apoptosis in HepG2 cells. Transwell and scratch experiments were used to detect HepG2 cell migration and invasion capabilities. Intergroup data were compared using t-tests or analysis of variance. Results: Compared with the paracancerous tissue and normal hepatocytes, miR-424-5p in the HCC tissue and hepatocellular cells was significantly down-regulated (the relative expression was 0.604±0.121, 0.585±0.064), and KIF23 was significantly up-regulated (the relative expression was 5.451±1.834, 2.482±0.545), P<0.05. miR-424-5p mimic can inhibit the proliferation, migration and invasion of HCC cells and promote apoptosis of HCC cells (P<0.05). Overexpression of KIF23 can promote the proliferation, migration and invasion of HCC cells and inhibit apoptosis of HCC cells (P<0.05). The luciferase activity of HepG2 cells in the mimic and KIF23-WT co-transfection groups was significantly reduced compared with HepG2 cells in the mimic NC and KIF23-WT co-transfection groups (the relative fluorescence intensities were 3.668±0.091 and 2.629±0.056, respectively, P<0.05),however, there was no significant comparison between the luciferase activity of cells in the mimic and KIF23-MT co-transfection groups compared with those in the mimic NC and KIF23-MT co-transfection groups. miR-424-5p mimic can reverse the role of overexpression of KIF23 in promoting the ability of HCC cells to proliferate, migrate and invade (P<0.05). The inhibition rates of sorafenib on HepG2 cells in the mimic+OE-KIF23 group and the OE-KIF23 group were 47.491%±3.863% and 36.246%±6.063% (t=3.027, P<0.05). Conclusion: miR-424-5p can inhibit the proliferation, migration and invasion of HCC cells and can increase the sensitivity of HCC cells to sorafenib by targeting the expression level of KIF23.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , MicroRNAs , Microtubule-Associated Proteins , Humans , Carcinoma, Hepatocellular/pathology , Cell Movement/genetics , Cell Proliferation/genetics , Family , Gene Expression Regulation, Neoplastic , Kinesins/genetics , Kinesins/metabolism , Liver Neoplasms/pathology , MicroRNAs/genetics , MicroRNAs/metabolism , Sorafenib/pharmacology , Hep G2 Cells , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism
8.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 40(11): 854-856, 2022 Nov 20.
Article in Zh | MEDLINE | ID: mdl-36510722

ABSTRACT

Trichloromethane and dichloromethane have toxic effects on the liver, and incidents of toxic liver disease caused by them have been reported from time to time. In November 2021, an occupational chemical poisoning incident occurred in a shoe factory in Huidong County, Guangdong Province. After testing the air at the scene and analyzing the clinical data of the poisoning patients, it was preliminarily determined that the poisoning was caused by a mixed gas poisoning incident dominated by trichoromethane. At admission, the liver function of 7 patients was tested for different degrees of impairment (alanine aminotransferase 145-2501 IU/L, aspartate aminotransferase 66-1286 IU/L). The volatile organic components of on-site raw and auxiliary materials were analyzed. The percentages of trichloromethane and dichloromethane detected in 103A powder glue used in the poisoning workshop site accounted for 21.11% and 6.77% respectively.


Subject(s)
Gas Poisoning , Liver Diseases , Humans , Alanine Transaminase , Aspartate Aminotransferases
9.
Phys Rev Lett ; 127(15): 152702, 2021 Oct 08.
Article in English | MEDLINE | ID: mdl-34678013

ABSTRACT

Fluorine is one of the most interesting elements in nuclear astrophysics, where the ^{19}F(p,α)^{16}O reaction is of crucial importance for Galactic ^{19}F abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the essential ^{19}F(p,αγ)^{16}O reaction channel. The γ-ray yields were measured over E_{c.m.}=72.4-344 keV, covering the Gamow window; our energy of 72.4 keV is unprecedentedly low, reported here for the first time. The experiment was performed under the extremely low cosmic-ray-induced background environment of the China JinPing Underground Laboratory, one of the deepest underground laboratories in the world. The present low-energy S factors deviate significantly from previous theoretical predictions, and the uncertainties are significantly reduced. The thermonuclear ^{19}F(p,αγ)^{16}O reaction rate has been determined directly at the relevant astrophysical energies.

10.
J Eur Acad Dermatol Venereol ; 35(6): 1393-1406, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33428294

ABSTRACT

BACKGROUND: Verrucous epidermal naevi (VEN) are benign skin tumours, considered keratinocytic epidermal naevi, that appear at birth or early childhood. VEN may display a range of appearances, depending on patient age. Although the number of studies regarding VEN is increasing, the exact mechanism of VEN is still unknown. OBJECTIVES: The aim of this study was to analyse the changes in the expression of protein factors in lesions of VEN children by TMT labelling-based quantitative proteomics. METHODS: A total of 8 children with VEN (5 for experiment and 3 for validation) and 8 healthy children (5 for experiment and 3 for validation) presented to the Department of Dermatology, the First Affiliated Hospital of Anhui Medical University, Boao Super Hospital, between January 2019 and November 2019. The lesions and lesion-adjacent tissues from children with VEN and naevus-adjacent normal skin tissues from children with pigmented naevi were defined as the VEN group, VENC group and C group, respectively. We performed a proteomics analysis to screen for differentially expressed proteins in the lesions of these individuals. We further performed Western blotting to validate the relative expression levels of nine targeted proteins in the validation group. RESULTS: According to the proteomics results, a total of 4970 proteins were identified, and 4770 proteins were quantified. Among these proteins, 586 proteins were up- or downregulated at least 1.3-fold with a P-value < 0.05 (upregulated: 399, downregulated: 187) in lesions between the VEN group and the C group. These proteins played important roles in multiple biological functions, such as cornification, epidermal cell differentiation and neutrophil activation, and formed a complicated protein-protein interaction network. Of the 586 up- or downregulated proteins, nine were selected for further validation. According to Western blotting analysis results, the relative expression levels of Involucrin, NDUFA4, Loricrin, Keratin type II cytoskeletal 6A (Cytokeratin 6A), BRAF, Filaggrin, S100A7 and Desmocollin-3 were significantly upregulated in VEN children and may be associated with skin barrier dysfunction, epidermal cell overgrowth and differentiation, inflammation and immune and oxidative phosphorylation, which are involved in the pathogenesis of VEN. CONCLUSIONS: According to TMT-based proteomics and Western blotting results, we identified eight noteworthy proteins, Involucrin, NDUFA4, Loricrin, Keratin type II cytoskeletal 6A, BRAF, Filaggrin, S100A7 and Desmocollin-3, that were upregulated in the lesions of VEN children and may be associated with the pathogenesis of VEN. Our findings provide new starting points for identifying precise pathogenic mechanisms or therapeutic targets for VEN.


Subject(s)
Nevus, Pigmented , Nevus, Sebaceous of Jadassohn , Skin Neoplasms , Child , Child, Preschool , Filaggrin Proteins , Humans , Infant, Newborn , Keratinocytes , Proteomics
11.
Tech Coloproctol ; 25(1): 75-80, 2021 01.
Article in English | MEDLINE | ID: mdl-32712932

ABSTRACT

BACKGROUND: The aim of the present study was to evaluate clinical efficacy and safety of superselective embolization of the superior rectal artery (SRA) for the treatment of internal hemorrhoidal bleeding. METHODS: Patients with stage II and stage III internal hemorrhoids, treated by interventional embolization of the SRA in our department between January 2017 and June 2019 were retrospectively evaluated. All patients suffering from disabling chronic hematochezia and some with relative contraindications for operation (n = 17) or rejection of conventional hemorrhoidectomy (n = 15). Superselective SRA branch embolization was performed using gelatin sponge particles (350-560 µm) and metallic coils (2-3 mm). This treatment process was planned by a multidisciplinary team consisting of proctologist, gastroenterologist and radiologist. The surgical efficacy, postoperative complications and follow-up outcomes were observed. RESULTS: There were 32 patients (18 males, mean age 52 ± 12 years, range: 22-78 years), 12 (37%) with stage II hemorrhoids and 20 (63%) with stage III hemorrhoids. Embolization was successful in all patients, and bleeding symptoms resolved in 27 (84.4%) patients. The remaining 5 (15.6%) patients underwent either stapled hemorrhoidopexy (n = 4) or sclerotherapy (n = 1). Some patients experienced different degrees of pain (n = 4;12.5%), low fever (n = 11;34.4%), and tenesmus (n = 17;53.1%), which all spontaneously regressed without further treatment. All patients were followed up for at least 1 year. There were no serious complications, such as infection, intestinal ischemia or massive hemorrhage. Four patients (14.8%) had rebleeding during the first months of follow-up. All patients with re-bleeding were successfully treated with internal iliac arteriography and branch embolization and did not experience further bleeds after a minimum follow up 3 months follow-up. CONCLUSIONS: The short-term efficacy of superselective SRA embolization for grade II-III internal hemorrhoids is good, and this method is safe and feasible.


Subject(s)
Embolization, Therapeutic , Hemorrhoids , Adult , Female , Gastrointestinal Hemorrhage/therapy , Hemorrhoids/complications , Hemorrhoids/therapy , Humans , Male , Mesenteric Artery, Inferior/diagnostic imaging , Middle Aged , Retrospective Studies , Treatment Outcome
12.
Zhonghua Yi Xue Za Zhi ; 101(41): 3427-3430, 2021 Nov 09.
Article in Zh | MEDLINE | ID: mdl-34758548

ABSTRACT

This study was a prospective single arm trial conducted in Zhejiang Jinhua Guangfu hospital from February 2018 to June 2020. A total of 39 patients (32 males and 7 females) with esophageal cancer, aged from 44 to 82 (69±9) years were enrolled. Diffusion weighted magnetic resonance imaging(MR-DWI) was implemented to evaluate the changes of apparent diffusion coefficient(ADC) value before and after chemoradiotherapy. The results showed that the ADC value after chemoradiotherapy was higher than that before treatment[(2.03±0.42)×10⁻³ mm 2/s vs (1.60±0.28)×10⁻³ mm2/s], and there was a positive correlation between the increase of ADC value and the prognosis of patients.


Subject(s)
Esophageal Neoplasms , Adult , Aged , Aged, 80 and over , Chemoradiotherapy , Diffusion Magnetic Resonance Imaging , Esophageal Neoplasms/diagnostic imaging , Esophageal Neoplasms/therapy , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prognosis , Prospective Studies
13.
J Lipid Res ; 61(6): 870-883, 2020 06.
Article in English | MEDLINE | ID: mdl-32156718

ABSTRACT

Gram-negative bacteria possess an asymmetric outer membrane (OM) composed primarily of lipopolysaccharides (LPSs) on the outer leaflet and phospholipids (PLs) on the inner leaflet. The loss of this asymmetry due to mutations in the LPS biosynthesis or transport pathways causes the externalization of PLs to the outer leaflet of the OM and leads to OM permeability defects. Here, we used metabolic labeling to detect a compromised OM in intact bacteria. Phosphatidylcholine synthase expression in Escherichia coli allowed for the incorporation of exogenous propargylcholine into phosphatidyl(propargyl)choline and exogenous 1-azidoethyl-choline (AECho) into phosphatidyl(azidoethyl)choline (AEPC), as confirmed by LC/MS analyses. A fluorescent copper-free click reagent poorly labeled AEPC in intact wild-type cells but readily labeled AEPC from lysed cells. Fluorescence microscopy and flow cytometry analyses confirmed the absence of significant AEPC labeling from intact wild-type E. coli strains and revealed significant AEPC labeling in an E. coli LPS transport mutant (lptD4213) and an LPS biosynthesis mutant (E. coli lpxC101). Our results suggest that metabolic PL labeling with AECho is a promising tool for detecting a compromised bacterial OM, revealing aberrant PL externalization, and identifying or characterizing novel cell-active inhibitors of LPS biosynthesis or transport.


Subject(s)
Bacterial Outer Membrane/metabolism , Escherichia coli/cytology , Escherichia coli/metabolism , Microscopy, Fluorescence , Phospholipids/metabolism , Biological Transport , Staining and Labeling
14.
J Biol Regul Homeost Agents ; 34(6): 1993-2001, 2020.
Article in English | MEDLINE | ID: mdl-33191714

ABSTRACT

Chemotherapy resistance has become a major obstacle to effective treatment of human cancer. This study aimed to investigate the effect of lncRNA XIST on cell proliferation and cisplatin (CDDP) of oral squamous cell carcinoma (OSCC). RT-qPCR and Western blot analysis were used to detect mRNA and protein expression. CCK-8 and flow cytometry assays were explored to evaluate CDDP sensitivity in OSCC cells. The relationship between lncRNA XIST and miR-27b-3p was confirmed by luciferase reporter assay. The results showed that lncRNA XIST was upregulated in OSCC tissues, cell lines, and CDDP-resistant OSCC cells. Functionally, upregulation of lncRNA XIST promoted cell proliferation, enhanced CDDP resistance, and inhibited apoptosis in OSCC cells. In addition, lncRNA XIST acts as a molecular sponge for miR-27b-3p in OSCC. Downregulation of miR-27b-3p partially reversed the tumor suppression effect and CDDP chemosensitivity of XIST knockdown in CDDP-resistant OSCC cells. In conclusion, lncRNA XIST promotes cell proliferation and enhances resistance to CDDP in OSCC by downregulating miR-27b-3p.


Subject(s)
MicroRNAs/genetics , Mouth Neoplasms , RNA, Long Noncoding/genetics , Squamous Cell Carcinoma of Head and Neck , Cell Proliferation/genetics , Cisplatin/pharmacology , Humans , Mouth Neoplasms/drug therapy , Mouth Neoplasms/genetics
15.
J Vis ; 20(12): 10, 2020 11 02.
Article in English | MEDLINE | ID: mdl-33237290

ABSTRACT

We investigate how the population nonlinearities resulting from lateral inhibition and thresholding in sparse coding networks influence neural response selectivity and robustness. We show that when compared to pointwise nonlinear models, such population nonlinearities improve the selectivity to a preferred stimulus and protect against adversarial perturbations of the input. These findings are predicted from the geometry of the single-neuron iso-response surface, which provides new insight into the relationship between selectivity and adversarial robustness. Inhibitory lateral connections curve the iso-response surface outward in the direction of selectivity. Since adversarial perturbations are orthogonal to the iso-response surface, adversarial attacks tend to be aligned with directions of selectivity. Consequently, the network is less easily fooled by perceptually irrelevant perturbations to the input. Together, these findings point to benefits of integrating computational principles found in biological vision systems into artificial neural networks.


Subject(s)
Neural Networks, Computer , Unsupervised Machine Learning , Visual Perception/physiology , Humans , Models, Neurological , Neurons/physiology , Nonlinear Dynamics , Stochastic Processes
16.
Fa Yi Xue Za Zhi ; 36(6): 762-766, 2020 Dec.
Article in Zh | MEDLINE | ID: mdl-33550723

ABSTRACT

ABSTRACT: Objective To explore a kind of visual evoked potential test equipment and method that is more suitable for the application of forensic clinical visual acuity evaluation. Methods Thirty-four volunteers (68 eyes) were selected, including 15 males and 19 females, aged between 20 and 40 years. Test lenses were placed before the tested eyes of volunteers to induce refractive myopia with insert method, and the diopter lenses were adjusted so that the visual acuity level of one eye of volunteers was above 0.8, and the visual acuity of the other eye was at moderate damage level (<0.3 and ≥0.1). The tests were carried out under the binocular simultaneous asynchronous stimulation mode (hereinafter referred to as "binocular mode") and monocular separate stimulation mode (hereinafter referred to as "monocular mode") of virtual reality-pattern visual evoked potential (VR-PVEP), and the amplitude of PVEP of volunteers under the two modes was compared at four spatial frequencies of 8×8, 16×16, 24×24 and 32×32. Results The differences in the amplitude of P100 wave between monocular and binocular modes at 8×8 spatial frequency had no statistical significance and the differences in amplitude of P100 wave between monocular and binocular modes at 16×16, 24×24, and 32×32 spatial frequencies had statistical significance (P<0.05). The amplitude of the same eye in monocular mode was higher than that in binocular mode. Through correlation analysis, it was found that the amplitude of P100 wave in monocular mode was moderately correlated with amplitude of P100 wave in binocular mode. Conclusion In forensic identification practice, VR-PVEP is helpful for overcoming the disturbance of poor fixation, and to increase the reliability of PVEP evaluation results. It can greatly shorten the detection time of PVEP and improve work efficiency.


Subject(s)
Evoked Potentials, Visual , Virtual Reality , Adult , Eye , Female , Humans , Male , Reproducibility of Results , Visual Acuity , Young Adult
17.
Hum Mol Genet ; 26(19): 3792-3796, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28934391

ABSTRACT

Heterozygous mutations in KIDINS220 were recently suggested a cause of spastic paraplegia, intellectual disability, nystagmus and obesity. All patients carried terminal nonsense de novo mutations that seemed to escape nonsense-mediated mRNA decay. The mechanism for pathogenicity is yet unexplained, as it seems that heterozygous loss-of-function variants of KIDINS220 are generally well tolerated. We present a consanguineous couple who experienced four pregnancy terminations due to repeated findings in the fetuses comprising enlarged cerebral ventricles and limb contractures. Exome sequencing in two of the aborted fetuses revealed a shared homozygous frameshift variant in exon 24 in KIDINS220. Sanger sequencing of the variant in available family members showed complete segregation with the affection status, resulting in a LOD score of 2.5 under an autozygous inheritance model. mRNA studies revealed destruction of the original splice site, resulting in an out-of-frame transcript and introduction of a premature termination codon in exon 25. Premature termination codons in this position are likely to cause activation of nonsense-mediated mRNA decay and result in complete absence of KIDINS220 protein in individuals homozygous for the variant. The phenotype of the presented fetuses overlaps with findings in functional studies of knockout Kidins220 mice embryos that are non-viable with enlarged cerebral ventricles. The human fetuses also exhibit several similarities to the milder phenotype described in patients with heterozygous KIDINS220 mutations. We hence propose that the identified homozygous loss-of-function variant in KIDINS220 causes the phenotype in the presented fetuses, and that this represents a hitherto undescribed severe autosomal recessive neurodevelopmental disorder.


Subject(s)
Hydrocephalus/genetics , Membrane Proteins/genetics , Membrane Proteins/metabolism , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Codon, Nonsense , Contracture/genetics , Exome , Exons , Female , Fetus , Frameshift Mutation , Homozygote , Humans , Hydrocephalus/metabolism , Intellectual Disability/genetics , Limb Deformities, Congenital/genetics , Loss of Function Mutation/genetics , Mutation , Nonsense Mediated mRNA Decay , Pregnancy
18.
J Biol Chem ; 292(36): 15143-15158, 2017 09 08.
Article in English | MEDLINE | ID: mdl-28663369

ABSTRACT

Pertussis-like toxins are secreted by several bacterial pathogens during infection. They belong to the AB5 virulence factors, which bind to glycans on host cell membranes for internalization. Host cell recognition and internalization are mediated by toxin B subunits sharing a unique pentameric ring-like assembly. Although the role of pertussis toxin in whooping cough is well-established, pertussis-like toxins produced by other bacteria are less studied, and their mechanisms of action are unclear. Here, we report that some extra-intestinal Escherichia coli pathogens (i.e. those that reside in the gut but can spread to other bodily locations) encode a pertussis-like toxin that inhibits mammalian cell growth in vitro We found that this protein, EcPlt, is related to toxins produced by both nontyphoidal and typhoidal Salmonella serovars. Pertussis-like toxins are secreted as disulfide-bonded heterohexamers in which the catalytic ADP-ribosyltransferase subunit is activated when exposed to the reducing environment in mammalian cells. We found here that the reduced EcPlt exhibits large structural rearrangements associated with its activation. We noted that inhibitory residues tethered within the NAD+-binding site by an intramolecular disulfide in the oxidized state dissociate upon the reduction and enable loop restructuring to form the nucleotide-binding site. Surprisingly, although pertussis toxin targets a cysteine residue within the α subunit of inhibitory trimeric G-proteins, we observed that activated EcPlt toxin modifies a proximal lysine/asparagine residue instead. In conclusion, our results reveal the molecular mechanism underpinning activation of pertussis-like toxins, and we also identified differences in host target specificity.


Subject(s)
Bacterial Toxins/chemistry , Bacterial Toxins/pharmacology , Escherichia coli/chemistry , Heterotrimeric GTP-Binding Proteins/antagonists & inhibitors , Pertussis Toxin/chemistry , Animals , Cell Proliferation/drug effects , Chlorocebus aethiops , Dose-Response Relationship, Drug , Epithelial Cells/drug effects , HEK293 Cells , Heterotrimeric GTP-Binding Proteins/metabolism , Humans , Models, Molecular , Structure-Activity Relationship , Vero Cells
19.
Opt Express ; 26(2): 1083-1096, 2018 Jan 22.
Article in English | MEDLINE | ID: mdl-29401987

ABSTRACT

We present an indirect, non-destructive optical method for domain statistic characterization in disordered nonlinear crystals having homogeneous refractive index and spatially random distribution of ferroelectric domains. This method relies on the analysis of the wave-dependent spatial distribution of the second harmonic, in the plane perpendicular to the optical axis in combination with numerical simulations. We apply this technique to the characterization of two different media, Calcium Barium Niobate and Strontium Barium Niobate, with drastically different statistical distributions of ferroelectric domains.

20.
Br J Anaesth ; 120(5): 960-968, 2018 May.
Article in English | MEDLINE | ID: mdl-29661413

ABSTRACT

BACKGROUND: Intranasal dexmedetomidine produces safe, effective sedation in children and adults. It may be administered by drops from a syringe or by nasal mucosal atomisation (MAD NasalTM). METHODS: This prospective, three-period, crossover, double-blind study compared the pharmacokinetic (PK) and pharmacodynamic (PD) profile of i.v. administration with these two different modes of administration. In each session each subject received 1 µg kg-1 dexmedetomidine, either i.v., intranasal with the atomiser or intranasal by drops. Dexmedetomidine plasma concentration and Ramsay sedation score were used for PK/PD modelling by NONMEM. RESULTS: The i.v. route had a significantly faster onset (15 min, 95% CI 15-20 min) compared to intranasal routes by atomiser (47.5 min, 95% CI 25-135 min), and by drops (60 min, 95%CI 30-75 min), (P<0.001). There was no significant difference in sedation duration across the three treatment groups (P=0.88) nor in the median onset time between the two modes of intranasal administration (P=0.94). A 2-compartment disposition model, with transit intranasal absorption and clearance driven by cardiac output using the well-stirred liver model, was the final PK model. Intranasal bioavailability was estimated to be 40.6% (95% CI 34.7-54.4%) and 40.7% (95% CI 36.5-53.2%) for atomisation and drops respectively. Sedation score was modelled via a sigmoidal Emax model driven by an effect compartment. The effect compartment had an equilibration half time 3.3 (95% CI 1.8-4.7) min-1, and the EC50 was estimated to be 903 (95% CI 450-2344) pg ml-1. CONCLUSIONS: There is no difference in bioavailability with atomisation or nasal drops. A similar degree of sedation can be achieved by either method. CLINICAL TRIAL REGISTRATION: HKUCTR-1617.


Subject(s)
Dexmedetomidine/pharmacology , Hypnotics and Sedatives/pharmacology , Administration, Intranasal , Administration, Intravenous , Adult , Cross-Over Studies , Dexmedetomidine/administration & dosage , Dexmedetomidine/pharmacokinetics , Double-Blind Method , Female , Humans , Hypnotics and Sedatives/administration & dosage , Hypnotics and Sedatives/pharmacokinetics , Male , Prospective Studies
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