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1.
J Virol ; 97(8): e0085123, 2023 08 31.
Article in English | MEDLINE | ID: mdl-37555660

ABSTRACT

SARS-CoV-2 can enter cells after its spike protein is cleaved by either type II transmembrane serine proteases (TTSPs), like TMPRSS2, or cathepsins. It is now widely accepted that the Omicron variant uses TMPRSS2 less efficiently and instead enters cells via cathepsins, but these findings have yet to be verified in more relevant cell models. Although we could confirm efficient cathepsin-mediated entry for Omicron in a monkey kidney cell line, experiments with protease inhibitors showed that Omicron (BA.1 and XBB1.5) did not use cathepsins for entry into human airway organoids and instead utilized TTSPs. Likewise, CRISPR-edited intestinal organoids showed that entry of Omicron BA.1 relied on the expression of the serine protease TMPRSS2 but not cathepsin L or B. Together, these data force us to rethink the concept that Omicron has adapted to cathepsin-mediated entry and indicate that TTSP inhibitors should not be dismissed as prophylactic or therapeutic antiviral strategy against SARS-CoV-2. IMPORTANCE Coronavirus entry relies on host proteases that activate the viral fusion protein, spike. These proteases determine the viral entry route, tropism, host range, and can be attractive drug targets. Whereas earlier studies using cell lines suggested that the Omicron variant of SARS-CoV-2 has changed its protease usage, from cell surface type II transmembrane serine proteases (TTSPs) to endosomal cathepsins, we report that this is not the case in human airway and intestinal organoid models, suggesting that host TTSP inhibition is still a viable prophylactic or therapeutic antiviral strategy against current SARS-CoV-2 variants and highlighting the importance of relevant human in vitro cell models.


Subject(s)
Serine Proteases , Humans , Antiviral Agents , COVID-19/virology , SARS-CoV-2/physiology , Serine Proteases/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
2.
BMC Pregnancy Childbirth ; 23(1): 308, 2023 May 02.
Article in English | MEDLINE | ID: mdl-37131147

ABSTRACT

BACKGROUND: In terms of embryonic origin, vascular ring is a congenital anomaly in which the aortic arch and its branches completely or incompletely encircle and compress the trachea or esophagus. Early and accurate diagnosis of a vascular ring is the key to treatment. Prenatal diagnosis mainly relies on fetal echocardiography, but the rate of missed diagnosis and misdiagnosis is still very high, and the prognosis has not been evaluated. The aim of this study was to investigate the accuracy of prenatal diagnosis and to evaluate the prognosis semi-quantitatively according to the shape of the ring and the distance between the vessel and the trachea. METHODS: From 2019 to 2021, 37,875 fetuses underwent prenatal ultrasound examination in our center. All fetal cardiac examinations were performed using the fetal echocardiography method proposed by the American Institute of Ultrasound in Medicine (AIUM) combined with dynamic sequential cross-sectional observation (SCS). For SCS, the standard abdominal section was taken as the initial section, and the probe was moved cephalically along the long axis of the body until the superior mediastinum had disappeared. If a vascular ring was found, the shape of the ring and the distance of the branch to the airway were observed. The distance relationship with the airway was divided into three grades: I-III; the closer the distance, the lower the grade. The vascular rings were monitored every 4 weeks before birth. All were monitored before surgery or 1 year after birth. RESULTS: A total of 418 cases of vascular rings were detected. There was no missed diagnoses or misdiagnoses by SCS. The vessels formed different shaped rings according to their origin and route. Grade I, "" and "O" rings have a poor prognosis and are associated with the highest risk of respiratory symptoms. CONCLUSIONS: SCS can accurately diagnose vascular rings before delivery, evaluate the shape and size of the rings to conduct prenatal monitoring of children until birth, which plays a guiding role in airway compression after birth.


Subject(s)
Vascular Ring , Female , Humans , Pregnancy , Cross-Sectional Studies , Prenatal Diagnosis/methods , Prognosis , Ultrasonography, Prenatal/methods
3.
Indoor Air ; 32(9): e13102, 2022 09.
Article in English | MEDLINE | ID: mdl-36168230

ABSTRACT

Incense burning is common in Asia including China. Research investigating the association between household incense burning and children's neurodevelopment is scarce. We aimed to examine this association in Chinese children. In 2019, we randomly enrolled 8293 children aged 6-12 years from 5 elementary schools in Guangzhou, southern China. Information on duration and frequency of household incense burning was collected using a questionnaire. Children's executive function was evaluated using the parental report of the Behavioral Rating Inventory of Executive Function. A general linear model was used to assess the associations between incense burning and executive function. Children who occasionally and frequently exposed to incense burning exhibited worse performance on executive function. For example, frequent incense burning was associated with increases in behavioral regulation index (BRI) of 1.77 (95%CI: 0.97, 2.58) points and metacognition index (MI) of 1.40 (95%CI: 0.60, 2.20) points, compared to never incense burning group. Parental smoking and household income were significant modifiers of the associations, with the stronger associations were observed in children having smoking parent(s) and poorer household income. The findings suggest that household incense burning was associated with poorer executive function, especially in children whose parent(s) were smokers and in those with low household income.


Subject(s)
Air Pollution, Indoor , Asian People , Child , China , Executive Function , Humans , Smoke/analysis
4.
Med Sci Monit ; 28: e935232, 2022 Mar 26.
Article in English | MEDLINE | ID: mdl-35338109

ABSTRACT

BACKGROUND Peak systolic volume (PSV), the essential parameter of penile Doppler ultrasonography (PDU), can reflect the penile artery blood supply. The present study was conducted to explore the correlations between PDU parameters and shear wave elastography (SWE), a feasible technology to measure penile stiffness. MATERIAL AND METHODS A total of 78 erectile dysfunction (ED) patients and 32 healthy controls were enrolled in our study. The PDU and SWE were performed to each participant simultaneously by a blinded radiologist. The penoscrotal junction was used to measure the PDU parameters and the SWE values. The PDU and SWE measurements were conducted formally at flaccid state and 5, 10, 15, 20, and 25 min after intra-cavernous injection (ICI) of vasoactive agents. RESULTS The significant correlation between PSV and SWE value was found in both ED patients (r=-0.748, P<0.001) and healthy controls (r=-0.815, P<0.001). SWE values of corpus cavernosum penis (CCP) decreased significantly with the increase of PSV during penile erection in both the ED patients and healthy controls. When the SWE value of CCP was less than 11.57 kPa, it showed that the penile artery blood supply was sufficient to finish satisfactory sexual intercourse. The sensitivity and specificity were 0.838 and 0.872, respectively. CONCLUSIONS Quantitative measurement of SWE values in CCP can reflect the penile arterial blood supply during PDU examination. The SWE technique could be used for evaluating the penile artery blood supply combined with the ICI test, with the advantages of noninvasiveness, simple operation, and excellent repeatability.


Subject(s)
Elasticity Imaging Techniques , Erectile Dysfunction , Elasticity Imaging Techniques/methods , Erectile Dysfunction/diagnostic imaging , Humans , Male , Penile Erection , Penis/diagnostic imaging
5.
Ecotoxicol Environ Saf ; 236: 113491, 2022 May 01.
Article in English | MEDLINE | ID: mdl-35397443

ABSTRACT

Since non-covalent bound character and widespread application in numerous products, people are exposed to di-n-butyl phthalate (DBP) at low levels through various ways. Epidemiological studies suggested an association between DBP exposure and atherosclerosis (AS). Still, molecular mechanisms remain unclear. This study aimed to explore the effects of DBP on monocyte recruitment, a key and initial step of AS. EA.hy926 cells were treated with DBP (10-9-10-5 M) or DMSO as control. Chemotaxis assay was applied to investigate THP-1 recruitment. Expression of mRNA /miRNAs and proteins were measured by qRT-PCR and Western blotting, respectively. Levels of monocyte chemotactic protein 1 (MCP-1) in supernatant were detected by ELISA assay. Receptor internalization assay was performed to confirm C-C chemokine receptor type 2 (CCR2) subcellular localization in THP-1 cells and the binding between CCR2 and MCP-1. Dual-luciferase reporter assay was used to analyze the combination between miR-137-3p and specificity protein 1 (SP1), as well as SP1 and MCP-1. Results showed that number of recruited THP-1 cells after EA.hy926 cells treated by DBP was significantly higher than that in the control group due to promoted MCP-1 expression. In addition, expression of MCP-1 was regulated through miR-137-3p-SP1 cascade. Besides, overexpression of miR-137-3p reversed the increased number of recruited THP-1 cells. Our results implied that DBP might promote THP-1 recruitment by targeting miR-137-3p-SP1-MCP-1 in EA.hy926 cells.


Subject(s)
Atherosclerosis , MicroRNAs , Atherosclerosis/metabolism , Chemokine CCL2/genetics , Chemokine CCL2/metabolism , Dibutyl Phthalate/toxicity , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Monocytes , Receptors, Chemokine , Sp1 Transcription Factor/genetics , Sp1 Transcription Factor/metabolism
6.
Curr Psychol ; : 1-14, 2022 Jul 05.
Article in English | MEDLINE | ID: mdl-35813568

ABSTRACT

Residents of the United States and China have responded very differently to the implementation of COVID-19 preventive measures. This study introduces the uncertainty reduction theory and the need for cognitive closure (NFC) framework into the context of a public health crisis and compares models across the United States and China. Specifically, we collected survey data to examine how NFC, trust in government, and attitudes toward preventive measures predicted pandemic compliance behaviors, depressive symptoms, and life satisfaction among 745 college students (399 from China and 346 from the United States). Chinese participants trusted their government more, believed COVID preventive measures to be more beneficial, and reported more pandemic compliance and fewer depressive symptoms than U.S. PARTICIPANTS: Trust in government and attitudes towards preventive measures mediated the relationships between NFC and pandemic compliance behaviors among Chinese participants but not U.S. PARTICIPANTS: NFC predicted better mental health outcomes among participants in China compared to U.S. PARTICIPANTS: Trust in government mediated NFC and mental health outcomes among Chinese participants. Trust in government predicted better mental health (fewer depressive symptoms and more life satisfaction) in both the United States and China. Theoretical and practical implications of these findings for promoting mental health and pandemic compliance behavior during the COVID-19 pandemic are discussed.

7.
Nat Mater ; 19(2): 176-181, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31873229

ABSTRACT

Epitaxial strain can unlock enhanced properties in oxide materials, but restricts substrate choice and maximum film thickness, above which lattice relaxation and property degradation occur. Here we employ a chemical alternative to epitaxial strain by providing targeted chemical pressure, distinct from random doping, to induce a ferroelectric instability with the strategic introduction of barium into today's best millimetre-wave tuneable dielectric, the epitaxially strained 50-nm-thick n = 6 (SrTiO3)nSrO Ruddlesden-Popper dielectric grown on (110) DyScO3. The defect mitigating nature of (SrTiO3)nSrO results in unprecedented low loss at frequencies up to 125 GHz. No barium-containing Ruddlesden-Popper titanates are known, but the resulting atomically engineered superlattice material, (SrTiO3)n-m(BaTiO3)mSrO, enables low-loss, tuneable dielectric properties to be achieved with lower epitaxial strain and a 200% improvement in the figure of merit at commercially relevant millimetre-wave frequencies. As tuneable dielectrics are key constituents of emerging millimetre-wave high-frequency devices in telecommunications, our findings could lead to higher performance adaptive and reconfigurable electronics at these frequencies.

8.
Environ Res ; 192: 110289, 2021 01.
Article in English | MEDLINE | ID: mdl-33027626

ABSTRACT

BACKGROUND: Previous studies have indicated that exposure to green space may benefit human health. However, the available evidence concerning the effects of greenness, especially school-based greenness, on pediatric obesity is scarce. OBJECTIVE: To explore the association between school-based greenness and adiposity in children and adolescents in China. METHOD: We conducted a nationwide cross-sectional study of 56,620 children and adolescents (aged 6-18 years) in seven provinces/municipalities across China. School-based greenness was assessed using satellite-derived Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) within 100-, 500-, and 1000-m circular buffers around each school's address. Generalized linear mixed regression models were used to estimate associations of greenness with BMI z-scores (zBMI), waist circumference, and prevalent overweight/obesity. We also explored the potential mediating role of ambient air pollution and physical activity in the greenness-adiposity associations. RESULT: In the adjusted model, an IQR increase in NDVI-1000m was associated with lower zBMI (ß: -0.11, 95% confidence interval[CI]: -0.13,-0.09) and waist circumference (ß: -0.64, 95%CI: -0.78,-0.50). Consistently, an IQR increase in NDVI-100m, NDVI-500m, NDVI-1000m was associated with 7-20% lower odds of overweight/obesity in the adjusted models. Air pollutants mediated 6.5-29.1% of the association between greenness and zBMI. No significant mediation effect was observed for physical activity. CONCLUSION: Higher school-based greenness levels were associated with lower zBMI, waist circumference, and lower odds of overweight and obesity in children and adolescents. Ambient air pollutants may partially mediate the greenness-adiposity associations.


Subject(s)
Adiposity , Pediatric Obesity , Adolescent , Child , China/epidemiology , Cities , Cross-Sectional Studies , Humans , Pediatric Obesity/epidemiology , Schools
9.
Acta Paediatr ; 110(2): 549-555, 2021 02.
Article in English | MEDLINE | ID: mdl-32573028

ABSTRACT

AIM: This study assessed the trends in the age at menarche in Chinese schoolgirls from the majority Han group and 21 ethnic minorities from 2005 to 2014. We also compared the group differences during the study period. METHODS: A total of 344 230 girls aged 9-18 years were extracted from the 2005, 2010 and 2014 Chinese National Survey on Students' Constitution and Health. The age at menarche for each subgroup was estimated by probit analysis. The chi-square test and Z-test were used to compare the differences between the groups. RESULTS: The overall average age at menarche in Chinese schoolgirls decreased from 12.8 years in 2005 to 12.3 years in 2014. The Han girls and girls from 17 ethnic minorities showed decreasing trends in the age at menarche, while four ethnic minorities demonstrated fluctuating increasing trends over time. The gaps in age at menarche between the Han group and 14 of the ethnic minorities became smaller over the study period and were similar by 2014. CONCLUSION: The overall findings were a decrease in the age at menarche in China and smaller gaps between the majority Han group and ethnic minority groups. Ethnic-specific public health policies are urgently needed on issues such as contraception.


Subject(s)
Ethnicity , Menarche , Adolescent , Asian People , Child , China , Female , Humans , Infant , Minority Groups
10.
Ecotoxicol Environ Saf ; 215: 112130, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-33743404

ABSTRACT

Environmental exposure to arsenic can cause a variety of health problems. Epidemiological and experimental studies have established a diabetogenic role for arsenic, but the mechanisms responsible for arsenic-induced impairment of insulin action are unclear. MicroRNAs (miRNAs) are involved in various metabolic disorders, particularly in the development of insulin resistance. The present study investigated whether arsenite, an active form of arsenic, induces hepatic insulin resistance and the mechanisms underlying it. After male C57BL/6J mice were exposed to arsenite (0 or 20 ppm) in drinking water for 12 months, intraperitoneal glucose tolerance tests (IPGTTs) and insulin tolerance tests (ITTs) revealed an arsenite-induced glucose metabolism disorder. Hepatic glycogen levels were lower in arsenite-exposed mice. Further, for livers of mice exposed to arsenite, miR-191 levels were higher, and protein levels of insulin receptor substrate 1 (IRS1), p-IRS1, and phospho-protein kinase B (p-AKT) were lower. Further, glucose transporter 4 (GLUT4) had lower levels on the plasma membrane. For insulin-treated L-02 cells, arsenite decreased glucose consumption and glycogen levels, increased miR-191 levels, and inhibited the IRS1/AKT pathway and the translocation of GLUT4 from the cytoplasm to the plasma membrane. For insulin-treated L-02 cells, the decreases of glucose consumption, glycogen levels, GLUT4 on the plasma membrane, and p-AKT levels induced by arsenite were reversed by SC79 (agonist of AKT) and an miR-191 inhibitor; these effects caused by miR-191 inhibitor were restored by IRS1 siRNA. In insulin-treated L-02 cells, miR-191, via IRS1, was involved in the arsenite-induced decreases of glucose consumption and glycogen levels and in inhibition of the translocation of GLUT4. Thus, miR-191 blocking the translocation of GLUT4 was involved in arsenite-induced hepatic insulin resistance through inhibiting the IRS1/AKT pathway. Our study reveals a mechanism for arsenite-induced hepatic insulin resistance, which provides clues for discovering biomarkers for the development of type 2 diabetes and for prevention and treatment of arsenic poisoning.


Subject(s)
Arsenites/toxicity , Glucose Transporter Type 4/metabolism , Insulin Resistance/physiology , MicroRNAs/metabolism , Animals , Arsenites/metabolism , Diabetes Mellitus, Type 2/metabolism , Glucose/metabolism , Glycogen/metabolism , Insulin Receptor Substrate Proteins/genetics , Insulin Receptor Substrate Proteins/metabolism , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects
11.
Toxicol Appl Pharmacol ; 408: 115253, 2020 12 01.
Article in English | MEDLINE | ID: mdl-32991915

ABSTRACT

Exposure to arsenic, which occurs via various routes, can cause reproductive toxicity. However, the mechanism for arsenic-induced reproductive disorders in male mice has not been extensively investigated. Here, 6-week-old male mice were dosed to 0, 5, 10, or 20 ppm sodium arsenite (NaAsO2), an active form of arsenic, in drinking water for six months. For male mice exposed to arsenite, fertility was lower compared to control mice. Moreover, for exposed mice, there were lower sperm counts, lower sperm motility, and higher sperm malformation ratios. Further, the mRNA and protein levels of the gonadotropin-regulated testicular RNA helicase (DDX25) and chromosome region maintenance-1 protein (CRM1), along with proteins associated with high mobility group box 2 (HMGB2), phosphoglycerate kinase 2 (PGK2), and testicular angiotensin-converting enzyme (tACE) were lower. Furthermore, chronic exposure to arsenite led to lower H2A ubiquitination (ubH2A); histone H3 acetylation K18 (H3AcK18); and histone H4 acetylations K5, K8, K12, and K16 (H4tetraAck) in haploid spermatids from testicular tissues. These alterations disrupted deposition of protamine 1 (Prm1) in testes. Overall, the present results indicate that the ubiquitination and acetylation of histones is involved in the spermiogenesis disorders caused by chronic exposure to arsenite, which points to a previously unknown connection between the modification of histones and arsenite-induced male reproductive toxicity.


Subject(s)
Arsenites/toxicity , Histones/metabolism , Reproduction/drug effects , Acetylation/drug effects , Animals , Female , Fetal Resorption , Male , Maternal-Fetal Exchange , Mice, Inbred C57BL , Pregnancy , Semen Analysis , Sperm Count , Sperm Motility/drug effects , Spermatogenesis/drug effects , Spermatozoa/abnormalities , Spermatozoa/drug effects , Spermatozoa/physiology , Testis/abnormalities , Testis/drug effects , Ubiquitination/drug effects
12.
BMC Public Health ; 20(1): 1892, 2020 Dec 09.
Article in English | MEDLINE | ID: mdl-33298006

ABSTRACT

BACKGROUND: Self-harm and drinking are both serious problems in adolescents and many studies presented evidence of their association. However, gender differences in this association are seldom deeply discussed. Our study aimed to evaluate the prevalence of self-harm and explore its association with drinking behaviors by gender and investigate the extent to which the gender differences exist in the association between self-harm and drinking. METHODS: A total of 32,362 students in grades 7 to 12 in Beijing, China were anonymously surveyed and included in our study using two-stage, stratified probability proportion sampling. Self-harm, drinking behaviors and other basic information were obtained from an anonymous questionnaire. Demographic variables, self-harm and drinking behaviors were analyzed using the Chi-square test and the Gamma test between genders and the gender differences in this association were analyzed by Log-binomial regression. RESULTS: The total prevalence of self-harm was 13.7% with no significant gender difference (χ2 =0.352, P = 0.553). The prevalence of self-harm in girls decreased with age (G = -0.163, P < 0.001). Self-harm was associated with drinking behaviors in both boys and girls. The Log-binomial regression demonstrated that girls in the 16-19 years old group were at lower risk of self-harm than girls in the 12-15 years old group while this association was weaker in boys (1.493 vs 1.128). The higher OR for self-harm was found among girls with early drinking experiences compared with boys (2.565 vs 1.863). Girls who had previously drunk (i.e. drunk at least once) (2.211 vs 1.636), were currently drinking (3.400 vs 2.122) and performed binge drinking (6.357 vs 3.924) were at greater risk of self-harm than boys. CONCLUSION: Among high school students, self-harm has a significant positive association with drinking and girls with drinking behaviors are at higher risk of suffering self-harm. Identifying adolescents' drinking behaviors is of vital importance to self-harm prevention and special attention should be focused on younger girls.


Subject(s)
Self-Injurious Behavior , Sex Characteristics , Adolescent , Beijing/epidemiology , Child , China/epidemiology , Female , Humans , Male , Schools , Self-Injurious Behavior/epidemiology , Students , Surveys and Questionnaires , Young Adult
13.
Environ Toxicol ; 35(3): 377-384, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31705742

ABSTRACT

Sterol is synthesized from cholesterol which is from the hydrolysis of stored cholesteryl esters. The process of maintaining cholesterol homeostasis is regulated by SREBP2-STARD4. Lots of researches demonstrated that male steroidogenesis could be interfered by di-n-butyl phthalate (DBP) or monobutyl phthalate (MBP). However, mechanisms of MBP exposure in this process have not been uncovered clearly. The objectiveof this study was to explore roles of SREBP2 and STARD4 in cholesteryl estersynthesis stimulated by MBP in mouse Leydig tumor cells (MLTC-1). MLTC-1 exposedto 10-8, 10-7, 10-6, 10-5 M MBP showed that levels of cholestery ester were increased significantly at 10-7 M MBP. Besides, cholesteryl ester synthesis stimulated by MBP was down-regulate when STARD4 or SREBP2 were inhibited. Activity of SREBP2 binding to the promoter of STARD4 was increased after MBP exposure. This study suggests that MBP can increase cholesteryl ester synthesis through SREBP2-STARD4 signal pathway in MLTC-1 cells.


Subject(s)
Cholesterol Esters/biosynthesis , Membrane Transport Proteins/metabolism , Phthalic Acids/pharmacology , Signal Transduction/drug effects , Sterol Regulatory Element Binding Protein 2/metabolism , Animals , Cell Line, Tumor , Dibutyl Phthalate/pharmacology , Down-Regulation/drug effects , Male , Membrane Transport Proteins/chemistry , Membrane Transport Proteins/genetics , Mice , Promoter Regions, Genetic , RNA Interference , RNA, Small Interfering/metabolism , Sterol Regulatory Element Binding Protein 2/antagonists & inhibitors , Sterol Regulatory Element Binding Protein 2/genetics
14.
Mikrochim Acta ; 187(9): 518, 2020 08 26.
Article in English | MEDLINE | ID: mdl-32851535

ABSTRACT

A three-dimensional structured porous graphene oxide-polyethylenimine bead (pGP) is synthesized for immobilizing gold nanoparticles and modifying glutathione molecules (denoted as pGP/AuG). The pGP/AuG has open pore structure, honeycomb-like channels, and excellent hydrophilicity. By taking advantages of the porous structure, abundant binding sites, and multivalent interactions between glycopeptides and both glutathione molecules and free amino groups, the pGP/AuG is adopted to the selective enrichment of N-linked glycopeptides with low limit of detection (2 fmol), high enrichment selectivity (1:500), binding capacity (333.3 mg/g), recovery yield (91.3 ± 2.1%), and repeatability (< 6.0% RSD) using matrix-assisted laser desorption/ionization time of flight mass spectrometry detection method. Furthermore, the practical applicability of pGP/AuG is evaluated, in which 209 N-glycosylated peptides corresponding to 128 N-glycosylated proteins are identified from 1 µL human serum in three independent analysis procedures, suggesting the great potential for application in glycoproteome fields.Graphical abstract Schematic presentation of preparation for porous graphene oxide-based hydrophilic beads (pGP/AuG) with honeycomb-like microstructure. The pGP/AuG was successfully used for enriching and identifying glycopeptides from actual biological sample.


Subject(s)
Glutathione/chemistry , Glycopeptides/isolation & purification , Graphite/chemistry , Metal Nanoparticles/chemistry , Animals , Cattle , Glycopeptides/analysis , Gold/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Immunoglobulin G/analysis , Immunoglobulin G/chemistry , Immunoglobulin G/isolation & purification , Limit of Detection , Peptide Fragments/analysis , Peptide Fragments/isolation & purification , Porosity , Proteolysis , Serum Albumin, Bovine/analysis , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/isolation & purification , Solid Phase Extraction/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
15.
Nature ; 502(7472): 532-6, 2013 Oct 24.
Article in English | MEDLINE | ID: mdl-24132232

ABSTRACT

The miniaturization and integration of frequency-agile microwave circuits--relevant to electronically tunable filters, antennas, resonators and phase shifters--with microelectronics offers tantalizing device possibilities, yet requires thin films whose dielectric constant at gigahertz frequencies can be tuned by applying a quasi-static electric field. Appropriate systems such as BaxSr1-xTiO3 have a paraelectric-ferroelectric transition just below ambient temperature, providing high tunability. Unfortunately, such films suffer significant losses arising from defects. Recognizing that progress is stymied by dielectric loss, we start with a system with exceptionally low loss--Srn+1TinO3n+1 phases--in which (SrO)2 crystallographic shear planes provide an alternative to the formation of point defects for accommodating non-stoichiometry. Here we report the experimental realization of a highly tunable ground state arising from the emergence of a local ferroelectric instability in biaxially strained Srn+1TinO3n+1 phases with n ≥ 3 at frequencies up to 125 GHz. In contrast to traditional methods of modifying ferroelectrics-doping or strain-in this unique system an increase in the separation between the (SrO)2 planes, which can be achieved by changing n, bolsters the local ferroelectric instability. This new control parameter, n, can be exploited to achieve a figure of merit at room temperature that rivals all known tunable microwave dielectrics.

16.
J Nanosci Nanotechnol ; 18(10): 6799-6804, 2018 10 01.
Article in English | MEDLINE | ID: mdl-29954496

ABSTRACT

Calcium phosphate silicate bone cement (CPSC) can stimulate osteoblast proliferation and promote osteogenesis, but how CPSC supress osteoclast activity through cytokine regulation is not clear. In the current study, we synthesized CPSC by incorporating monocalcium phosphate (MCP) into calcium silicate cement (CSC), and analyzed the effects of CSC and CPSC on osteoclast survival with MTT. And we found that both CSC and CPSC medium could decrease osteoclast cell viability, and flow cytometry further revealed that CSC and CPSC could inhibit osteoclast activity. To elucidate the underlying mechanism, related gene and protein level of cytokines that related to osteoclast activity were evaluted. The results demonstrated that osteoclast activity was inhibited in cells treated with cement. The effects were associated with a number of cytokines stimulated by cement. In conclusion, both CSC and CPSC seem to be good substitutes of bone replacement by inhibiting osteoclast activity; the exact mechanism of how they promote bone growth, however, needs further investigations.


Subject(s)
Bone Cements/pharmacology , Calcium Compounds/pharmacology , Calcium Phosphates/pharmacology , Cytokines/metabolism , Osteoclasts/drug effects , Silicate Cement/pharmacology , Silicates/pharmacology , Cell Survival/drug effects , Cytokines/genetics , Gene Expression Regulation/drug effects , Humans , Osteoclasts/cytology , Osteoclasts/metabolism
17.
Mikrochim Acta ; 185(4): 227, 2018 03 19.
Article in English | MEDLINE | ID: mdl-29594555

ABSTRACT

Enantiomeric separations of the adrenergic compounds adrenaline, noradrenaline, and isoprenaline were studied. Electromigrative separations were performed in uncoated fused silica capillaries using streptomycin-modified gold nanoparticles (ST-AuNPs) as an additive to the background electrolyte. The ST-AuNPs are shown to serve as an effective chiral selector. The modified AuNPs were characterized in terms of size and zeta potential, and by IR and UV-vis spectra. The effects of ST-AuNP concentration, pH value, temperature, and separation voltage on the separations were systematically studied. Under optimized experimental conditions, racemic mixtures of the respective adrenergic drugs were baseline-separated within 7 min with a resolution of up to 7.5. The relative standard deviations of the resolution in inter-day and intra-day studies (n = 5) were generally <5%. Graphical abstract Schematic of the method for enantiomeric separations. (A): At low concentrations of streptavidinylated gold nanoparticles (ST-AuNPs), the better matching enantiomer is preferably "transported" by the ST-AuNPs; (B) ST-AuNP concentration increased to an optimal value; (C): The ST-AuNP concentration is too high; even poorly matching enantiomers will be transported simultaneously.

18.
Immunology ; 148(4): 363-76, 2016 08.
Article in English | MEDLINE | ID: mdl-27135915

ABSTRACT

Dengue virus (DENV) infection is an emerging public health hazard threatening inhabitants of the tropics and sub-tropics. Dendritic cells (DCs) are one of the major targets of DENV and the initiators of the innate immune response against the virus. However, current in vitro research on the DENV-DC interaction is hampered by the low availability of ex vivo DCs and donor variation. In the current study, we attempted to develop a novel in vitro DC model using immature DCs derived from the myeloid leukaemia cell line MUTZ-3 (IMDCs) to investigate the DENV-DC interaction. The IMDCs morphologically and phenotypically resembled human immature monocyte-derived dendritic cells (IMMoDCs). However, the permissiveness of IMDCs to DENV2 was lower than that of IMMoDCs. RT-PCR arrays showed that a group of type I interferon (IFN) -inducible genes, especially IFIT1, IFITM1, and IFI27, were significantly up-regulated in IMMoDCs but not in IMDCs after DENV2 infection. Further investigation revealed that IFIT genes were spontaneously expressed at both transcriptional and protein levels in the naive IMDCs but not in the naive IMMoDCs. It is possible that the poor permissiveness of IMDCs to DENV2 was a result of the high basal levels of IFIT proteins. We conclude that the IMDC model, although less permissive to DENV2, is a useful platform for studying the suppression mechanism of DENV2 and we expand the knowledge of cellular factors that modulate DENV2 infection in the human body.


Subject(s)
Antigens, Differentiation/metabolism , Carrier Proteins/metabolism , Dendritic Cells/virology , Dengue Virus/immunology , Dengue/immunology , Membrane Proteins/metabolism , Monocytes/virology , Adaptor Proteins, Signal Transducing , Antigens, Differentiation/genetics , Carrier Proteins/genetics , Cell Differentiation , Cell Line , Dendritic Cells/physiology , Dengue/genetics , Humans , Immunity, Innate/genetics , Interferon Type I/metabolism , Membrane Proteins/genetics , Monocytes/physiology , RNA-Binding Proteins , Transcriptome , Up-Regulation
19.
Environ Sci Technol ; 50(14): 7687-95, 2016 07 19.
Article in English | MEDLINE | ID: mdl-27285880

ABSTRACT

Platinum-group metals (PGMs) are technological and economic enablers of many industrial processes. This important role, coupled with their limited geographic availability, has led to PGMs being labeled as "critical materials". Studies of future PGM flows have focused on trends within material flows or macroeconomic indicators. We complement the previous work by introducing a novel technoeconomic model of substitution among PGMs within the automotive sector (the largest user of PGMs) reflecting the rational response of firms to changing prices. The results from the model support previous conclusions that PGM use is likely to grow, in some cases strongly, by 2030 (approximately 45% for Pd and 5% for Pt), driven by the increasing sales of automobiles. The model also indicates that PGM-demand growth will be significantly influenced by the future Pt-to-Pd price ratio, with swings of Pt and Pd demand of as much as 25% if the future price ratio shifts higher or lower even if it stays within the historic range. Fortunately, automotive catalysts are one of the more effectively recycled metals. As such, with proper policy support, recycling can serve to meet some of this growing demand.


Subject(s)
Platinum , Rhodium , Automobiles , Catalysis , Palladium
20.
Med Sci Monit ; 22: 1244-9, 2016 Apr 14.
Article in English | MEDLINE | ID: mdl-27074962

ABSTRACT

BACKGROUND Parkinson's disease (PD) is manifested as degeneration of dopaminergic neurons in substantia nigra compacta. The mitochondrial dysfunction induced by oxidative stress is believed to a major cause of PD. Puerarin has been widely applied due to its estrogen nature and anti-oxidative function. This study thus investigated the protective role of puerarin against oxidative stress injury on PC12 neural cells, in addition to related mechanisms. MATERIAL AND METHODS PC12 cells were pre-treated with gradient concentrations of puerarin, followed by the induction of 0.5 mM H2O2. MTT assay was used to detect cell viability. Enzyme-linked immunosorbent assay (ELISA) was employed to detect intracellular level of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH). Cell apoptosis was determined by Annexin-V/7-AAD double labelling. Reactive oxidative species (ROS) and lactate dehydrogenase (LDH) activities were then measured. Cellular levels of caspase-3 and caspase-9 were also determined. RESULTS The pre-treatment using puerarin significantly reversed H2O2-induced oxidative stress injury, as it can increase proliferation, SOD and GSH activities, decrease MDA activity, suppress apoptosis of PC12 cells, and decrease ROS and LDH production (p<0.05 in all cases). Further assays showed depressed up-regulation of caspase-3 and caspase-9 after puerarin pretreatment. CONCLUSIONS Puerarin pretreatment can decrease activity of caspase-3 and caspase-9 activity in PC12 cells, thus protecting cells from oxidative injury.


Subject(s)
Isoflavones/pharmacology , Neurons/drug effects , Neurons/metabolism , Oxidative Stress/drug effects , Animals , Antioxidants/pharmacology , Apoptosis/drug effects , Caspase 3/metabolism , Caspase 9/metabolism , Cell Survival/drug effects , Cells, Cultured , Glutathione/metabolism , Malondialdehyde/metabolism , Neurons/pathology , Neuroprotective Agents/pharmacology , PC12 Cells , Rats , Reactive Oxygen Species/metabolism , Superoxide Dismutase/metabolism
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