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1.
J Nanosci Nanotechnol ; 20(2): 769-778, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383072

RESUMO

A super absorbent was synthesized from calcium-aluminum waste residue of aluminum industrial using a facile hydrothermal method. The XRD results revealed that the main phase of hydrothermal product at 120 °C is CaSO4 ·2H2O, with a small amount of Al(OH)3. The as-prepared products were used to investigate the adsorptive applications in Congo red (CR) removal, and the results showed that the products treated at 120 °C had the best adsorption properties. The maximum adsorption capacity reaches about 1860.11 mg/g with a removal rate of 99.75%. Furthermore, the used adsorbent could be regenerated for at least four cycles through a calcination procedure, indicating its potential as an excellent adsorbent for the removal of CR dye from wastewater. The adsorption behavior was analyzed by Langmuir, Freundlich and Sips isotherms, and the adsorption proved to be a multilayer adsorption. This facile method presented here may provide promise synthesis of high-effective and low-cost adsorbents from industrial solid waste and achieve the goal of "using waste to treat waste" in the future.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31725126

RESUMO

STUDY DESIGN: To evaluate the effect of p38 pathway on spinal cord injury (SCI), a rat model of SCI was performed. OBJECTIVE: We determined the effect of p38 on SCI and SCI related inflammation, apoptosis and autophagy. SUMMARY OF BACKGROUND DATA: SCI is a severe clinical problem worldwide. It is difficult to prevent cell necroptosis and promote the survival of residual neurons after SCI. p38, a class of mitogen-activated protein kinases (MAPKs), its effect on SCI and SCI related inflammation, apoptosis and autophagy have not been studied very well. METHODS: The rats were randomly divided into the following 4 groups: the sham-operated (sham) group, the SCI group, the SCI + vehicle group, and the SCI + SB203580 (10 mg/kg) group. The p38 inhibitor SB203580 was administered by oral (10 mg/kg/d) gavage once per day for 14 d. Neurological recovery was assessed using the Basso, Beattie, and Bresnahan (BBB) locomotion rating scale. Apoptosis, autophagy and inflammation related proteins were measured by ELISA kits or western blotting. RESULTS: Our results showed that p38 was upregulated after SCI from day 3, which was paralleled with the levels of its proteins ATF-2, suggesting an increase in p38 activity. Our results showed administration of SB203580 attenuated histopathology and promoted locomotion recovery in rats after SCI. SB203580 administration significantly inhibited inflammatory cytokines levels as well as the inflammation signaling pathway. SB203580 administration also modulated the apoptosis and autophagy signaling pathway. CONCLUSION: Our findings suggest that p38 inhibitor SB203580 treatment alleviates secondary SCI by inhibiting inflammation and apoptosis, thereby promoting neurological and locomoter functional recovery, thus suggest the important role of p38 in neuronal protection after SCI. LEVEL OF EVIDENCE: N/A.

3.
iScience ; 21: 549-561, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31715498

RESUMO

Multi-targeted kinase inhibitors, such as sorafenib, have been used in various malignancies, but their efficacy in clinical applications varies among individuals and lacks pretherapeutic prediction measures. We applied the concept of "click chemistry" to pathological staining and established a drug-loaded probe staining assay. We stained the cells and different types of pathological sections and demonstrated that the assay was reliable. We further verified in cells, cell-derived xenograft model, and clinical level that the staining intensity of the probe could reflect drug sensitivity. The stained samples from 300 patients who suffered from hepatocellular carcinoma and used the sorafenib probe also indicated that staining intensity was closely related to clinical information and could be used as an independent marker without undergoing sorafenib therapy for prognosis. This assay provided new ideas for multi-target drug clinical trials, pre-medication prediction, and pathological research.

4.
Jpn J Infect Dis ; 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31666494

RESUMO

Fever is a systemic inflammatory response of the body to pyrogens. Nuclear factor κB (NF-κB) is a central signalling molecule that causes the excessive secretion of various proinflammatory factors induced by pyrogens. This study explored the feasibility of a novel reporter gene assay (RGA) for pyrogen detection using RAW264.7 cells stably transfected with the NF-κB reporter gene as a pyrogenic marker. The RGA could detect different types of pyrogens, including the lipopolysaccharide of gram-negative bacteria, the lipoteichoic acid of gram-positive bacteria, and the zymosan of fungi, and a good dose-effect relationship was observed in terms of NF-κB activity. The limits of detection of the RGA to those pyrogens were 0.03 EU/ml, 0.001 µg/ml, and 1µg/ml, respectively. The method had good precision and accuracy and could be applied to many products [e.g., nivolumab, rituximab, bevacizumab, etanercept, basiliximab, Haemophilus influenza type b conjugate vaccine, 23-valent pneumococcal polysaccharide vaccine, group A and group C meningococcal conjugate vaccine, diphtheria, tetanus, pertussis (acellular, component), poliomyelitis (inactivated) vaccine, and imject alum adjuvant]. The results of this study suggest that the novel RGA has a wide pyrogen detection spectrum and is sufficiently sensitive, stable, and accurate for various applications.

5.
Curr Opin Insect Sci ; 37: 1-7, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31726320

RESUMO

Drosophila female germline stem cells (GSCs) serve as one of the best understood stem cell types. GSCs reside in a special microenvironment, the stem cell niche, and their activity is tightly regulated by niche-derived signals. In addition to the stemness-promoting signaling molecules, the niche also generates other signaling molecules that regulate GSC differentiation. Recent studies are beginning to appreciate the intricate interactions among these signaling molecules in the niche and their effects on GSC behaviour. This review summarizes recent advances to demonstrate how the niche functions as a signaling hub to integrate these niche-derived local signals as well as other organ-produced systemic signals to control GSC self-renewal and differentiation.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31774206

RESUMO

Lithium-ion batteries (LIBs) have become ubiquitous power sources for small electronic devices, electric vehicles, and stationary energy storage systems. Despite that the success of LIBs is acknowledged by their increasing commodity market, the historical evolution of the chemistry behind the LIB technologies is laden with obstacles and yet to be unambiguously documented. This Viewpoint outlines chronologically the most essential findings related to today's LIBs, including commercial electrode and electrolyte materials, but furthermore also depicts how the today popular and widely emerging solid-state batteries were instrumental at very early stages.

7.
Chem Commun (Camb) ; 55(89): 13462-13465, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31647072

RESUMO

The use of light to regulate the chirality of supramolecular assemblies in a non-invasive manner remains a challenge. Herein, we report a novel photochromic pseudo[3]rotaxane based on a (R/S)-2,2'-binaphthyl secondary ammonium salt guest (2) and anthracene-bridged bis(dibenzo-24-crown-8) (1), which features a chirality transfer and fluorescence resonance energy transfer (FRET) from 2 to 1. Benefiting from the photo-oxidation of anthracene, the induced circular dichroism (ICD) signals of (R/S)-2@1 can be switched off/on by irradiation with 365 nm UV light and heating. This noncovalent supramolecular assembly strategy provides us with unique opportunities to design and construct further smart photo-responsive chiral molecular switches.

8.
J Orthop Surg Res ; 14(1): 339, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31665053

RESUMO

PURPOSE: To restore rotation center exactly in total hip arthroplasty (THA) is technically challenging for patients with end-stage osteoarthritis due to developmental dysplasia of the hip (DDH). The technical difficulty is attributable to the complex acetabular changes. In this study, we investigated the pathomorphology of acetabulum and Harris fossa of Crowe types I to IV and discussed the method of restoring rotation center of the hip. METHODS: This study retrospectively reviewed 56 patients (59 hips) who underwent cementless THA due to end-stage osteoarthritis of DDH. The pathomorphology of acetabulum and Harris fossa was observed during operations. Using the preoperative and postoperative pelvic radiographs, the vertical and the horizontal distances of hip rotation center were measured in order to evaluate the effects of restoring rotation center of the hip. RESULTS: Adult DDH acetabulum could be classified into four basic pathological types which include the shallow cup shape, the dish shape, the shell shape, and the triangular shape. Adult DDH Harris fossa could be classified into four pathological types, including the crack shape, the closed shape, the triangle shape, and the shallow shape, in accordance with the osteophyte coverage. The vertical and horizontal distances of hip rotation center on the pelvic radiographs before and after operations were as follows: the preoperative vertical distance of hip rotation center was (39.96 ± 5.65) mm, and the postoperative one was (13.83 ± 2.66) mm; the preoperative horizontal distance of hip rotation center was (42.15 ± 6.42) mm, and the postoperative one was (28.12 ± 4.56) mm. CONCLUSIONS: The acetabulum and Harris fossa can display different pathological types on account of different degrees of dislocation and osteophyte hyperplasia in the end-stage osteoarthritis of adult DDH. The hip rotation center can be accurately restored by locating the acetabular center with Harris fossa and acetabular notch as the marks.

9.
Sensors (Basel) ; 19(20)2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31614855

RESUMO

Since the signals of the global navigation satellite system (GNSS) are blocked by buildings, accurate positioning cannot be achieved in an indoor environment. Pseudolite can simulate similar outdoor satellite signals and can be used as a stable and reliable positioning signal source in indoor environments. Therefore, it has been proposed as a good substitute and has become a research hotspot in the field of indoor positioning. There are still some problems in the pseudolite positioning field, such as: Integer ambiguity of carrier phase, initial position determination, and low signal coverage. To avoid the limitation of these factors, an indoor positioning system based on fingerprint database matching of homologous array pseudolite is proposed in this paper, which can achieve higher positioning accuracy. The realization of this positioning system mainly includes the offline phase and the online phase. In the offline phase, the carrier phase data in the indoor environment is first collected, and a fingerprint database is established. Then a variational auto-encoding (VAE) network with location information is used to learn the probability distribution characteristics of the carrier phase difference of pseudolite in the latent space to realize feature clustering. Finally, the deep neural network is constructed by using the hidden features learned to further study the mapping relationship between different carrier phases of pseudolite and different indoor locations. In the online phase, the trained model and real-time carrier phases of pseudolite are used to predict the location of the positioning terminal. In this paper, by a large number of experiments, the performance of the pseudolite positioning system is evaluated under dynamic and static conditions. The effectiveness of the algorithm is evaluated by the comparison experiments, the experimental results show that the average positioning accuracy of the positioning system in a real indoor scene is 0.39 m, and the 95% positioning error is less than 0.85 m, which outperforms the traditional fingerprint positioning algorithms.

10.
Infect Dis (Lond) ; : 1-6, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31596157

RESUMO

Objectives: By adopting a new method, this study aimed to analyse the epidemiological characteristics of hand, foot, and mouth disease (HFMD) in nine districts and counties (cities) of Changsha City, China, from 2009 to 2017. Methods: The reported HFMD cases were collected in Changsha from 2009 to 2017. The traditional descriptive method and a new method (index system) including six indices (richness index N, Simpson diversity index D, Shannon diversity index H, Berger-Parker dominance index d, Shannon evenness index E, and Morisita-Horn similarity index C) were used to describe the epidemiological characteristics of HFMD in Changsha. Results: There were 214155 HFMD reported in Changsha during the study period. The incidence of the disease was higher in even-numbered years (2010, 2012, 2014, and 2016) than in uneven-numbered years (2009, 2011, 2013, 2015, and 2017), with two peaks in May to June and October to November every year. The age of onset was mainly from 0 to 5 years old, and the death was mainly from 0 to 2 years old. According to occupational classification, districts and counties (cities) had a high degree of similarity of the composition of HFMD, and there was no regional difference. Conclusions: Changsha had a yearly increasing trend of HFMD from 2009 to 2017, and the key population for prevention and control was children aged in 0-5 years old. Seasonal distribution of high incidence and peak incidence were occurred in even-numbered years. The sub-regions of the city shared moderate diversity and high similarity of occupational distribution of HFMD.

11.
PLoS One ; 14(10): e0222702, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31600235

RESUMO

Slope one is a popular recommendation algorithm due to its simplicity and high efficiency for sparse data. However, it often suffers from under-fitting since the global information of all relevant users/items are considered. In this paper, we propose a new scheme called enhanced slope one recommendation through local information embedding. First, we employ clustering algorithms to obtain the user clusters as well as item clusters to represent local information. Second, we predict ratings using the local information of users and items in the same cluster. The local information can detect strong localized associations shared within clusters. Third, we design different fusion approaches based on the local information embedding. In this way, both under-fitting and over-fitting problems are alleviated. Experiment results on the real datasets show that our approaches defeats slope one in terms of both mean absolute error and root mean square error.

12.
Sensors (Basel) ; 19(20)2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31640250

RESUMO

A Global Satellite Navigation System (GNSS) cannot provide normal location services in an indoor environment because the signals are blocked by buildings. The Beidou satellite navigation system (BDS)/GPS indoor array pseudolite system is proposed to overcome the problems of indoor positioning with conventional pseudolite, such as time synchronization, ambiguity resolution and base stations. At the same time, an algorithm for Doppler differential positioning is proposed to improve the indoor positioning accuracy and the positioning coverage of the system, which uses the Doppler difference equation and Known Point Initialization (KPI) to determinate the velocity and position of the receiver. Experiments were conducted to verify the proposed system under different conditions; the average positioning error of the Doppler differential positioning algorithm was 7.86 mm in the kinematic test and 2.9 mm in the static test. The results show that BDS/GPS indoor array pseudolite system has the potential to make indoor positioning achieve sub-centimeter precision. Finally, the positioning error of the proposed algorithm is also analyzed, and the data tests show that the dilution of precision (DOP) and cycle- slips have a significant impact on the indoor positioning accuracy; a cycle-slip of a half-wavelength can cause positioning errors of tens of millimeters. Therefore, the Doppler-aided cycle-slip detection method (DACS) is proposed to detect cycle-slips of one cycle or greater than one, and the carrier phase double difference cycle-slip detection method (CPDD) is used to detect cycle slips of a half-wavelength.

13.
Pregnancy Hypertens ; 18: 150-155, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31622820

RESUMO

OBJECTIVES: Preeclampsia (PE)/eclampsia (E) is an important cause of foetal and maternal morbidity and mortality, and its aetiology is poorly understood. Good evidence suggests that renin (REN) might be associated with PE/E. The risk of PE/E is determined by both maternal and foetal genes, but most previous studies have focused on maternal contributions. This study aimed to explore the association of maternal and foetal REN polymorphisms with PE/E in pregnant Han Chinese women. METHODS: A case-parents/mother-control study including 347 PE/E patients with their partners and offspring and 700 control mothers with their offspring was conducted. A log-linear model was used to investigate the association between maternal and foetal REN SNPs and PE/E simultaneously, as well as the interaction of REN SNPs and environmental factors on PE/E. RESULTS: The foetal REN rs5707 AC genotype in combination with a pre-pregnancy BMI ≥ 24 kg/m2 was significantly associated with an increased risk of PE/E, with an OR of 2.75 (95%CI = 1.50-5.06). Maternal and foetal rs5707 were significantly associated with an increased risk of PE/E under the recessive model (AA + AC/CC). In haplotype analyses, foetal CCT (in the order of rs2368564, rs5707, rs5705) and TAT genotypes were positively associated with the risk of PE/E. There was no significant association between maternal and foetal REN SNP genotypes and PE/E in the transmission disequilibrium test (TDT) and log-linear model analysis. CONCLUSIONS: Findings from this study indicate that foetal rs5707 polymorphisms may play a significant role in PE/E development, especially among overweight or obese pregnant women in China.

14.
Life Sci ; 239: 116935, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31610203

RESUMO

BACKGROUND: The protective effects of gastrodin and rhynchophylline in ischaemic injury have been reported. However, the underlying mechanism and the effect of the combination of these two drugs in ischaemic injury remain unclear. Herein, we aimed to explore the effects of the combination of gastrodin and rhynchophylline on ischaemia-induced inflammasome activation as well as the underlying mechanism. METHODS: Middle cerebral artery occlusion (MCAO) mice and oxygen glucose deprivation (OGD)-treated BV2 cells were used as in vivo and in vitro models of ischaemia, respectively. Cerebral injury was determined by TTC staining, H&E staining and neurological deficit scores. The effects of the combination of gastrodin and rhynchophylline on inflammasome activation were measured by the MTT assay, Western blotting and ELISA. The expression of miR-21-5p and miR-331-5p was measured by qRT-PCR. The potential binding between miR-21-5p and TXNIP and between miR-331-5p and TRAF6 was analysed with Targetscan and a luciferase assay. RESULTS: MCAO-induced tissue infarction, neurological deficits, inflammasome activation, and downregulation of miR-21-5p and miR-331-5p were all mitigated by the combination of gastrodin and rhynchophylline. In OGD-treated BV2 cells, the combination of gastrodin and rhynchophylline also alleviated inflammasome activation and restored the expression of miR-21-5p and miR-331-5p. TXNIP and TRAF6 were confirmed to be targets of miR-21-5p and miR-331-5p, respectively. Moreover, OGD-induced inflammasome activation was attenuated by the overexpression of either miR-331-5p or miR-21-5p and was further attenuated by the overexpression of both. Finally, we demonstrated that a miR-21-5p inhibitor and/or a miR-331-5p inhibitor counteracted the protective effects of gastrodin and/or rhynchophylline. CONCLUSIONS: The combination of gastrodin and rhynchophylline exerts neuroprotective effects by preventing ischaemia-induced inflammasome activation via upregulating miR-21-5p and miR-331-5p.

15.
Clin Sci (Lond) ; 133(20): 2045-2059, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31654061

RESUMO

BACKGROUND: Pulmonary artery endothelial cell (PAEC) inflammation is a critical event in the development of pulmonary arterial hypertension (PAH). However, the pathogenesis of PAEC inflammation remains unclear. METHODS: Purified recombinant human inhibitor of κB kinase subunit ß (IKKß) protein, human PAECs and monocrotaline-induced pulmonary hypertensive rats were employed in the study. Site-directed mutagenesis, gene knockdown or overexpression were conducted to manipulate the expression or activity of a target protein. RESULTS: We showed that hydrogen sulfide (H2S) inhibited IKKß activation in the cell model of human PAEC inflammation induced by monocrotaline pyrrole-stimulation or knockdown of cystathionine γ-lyase (CSE), an H2S generating enzyme. Mechanistically, H2S was proved to inhibit IKKß activity directly via sulfhydrating IKKß at cysteinyl residue 179 (C179) in purified recombinant IKKß protein in vitro, whereas thiol reductant dithiothreitol (DTT) reversed H2S-induced IKKß inactivation. Furthermore, to demonstrate the significance of IKKß sulfhydration by H2S in the development of PAEC inflammation, we mutated C179 to serine (C179S) in IKKß. In purified IKKß protein, C179S mutation of IKKß abolished H2S-induced IKKß sulfhydration and the subsequent IKKß inactivation. In human PAECs, C179S mutation of IKKß blocked H2S-inhibited IKKß activation and PAEC inflammatory response. In pulmonary hypertensive rats, C179S mutation of IKKß abolished the inhibitory effect of H2S on IKKß activation and pulmonary vascular inflammation and remodeling. CONCLUSION: Collectively, our in vivo and in vitro findings demonstrated, for the first time, that endogenous H2S directly inactivated IKKß via sulfhydrating IKKß at Cys179 to inhibit nuclear factor-κB (NF-κB) pathway activation and thereby control PAEC inflammation in PAH.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31661944

RESUMO

A growing body of research has shown that people's attitudes toward food safety is affected by their availability and accessibility to food risk information. In the digital era, the Internet has become the most important channel for information acquisition. However, empirical evidence related to the impact of Internet use on people's attitudes towards food safety is inadequate. In this study, by employing the Chinese Social Survey for 2013 and 2015, we have investigated the current situation of food safety perceptions and evaluations among Chinese residents and the association between Internet use and individuals' food safety evaluations. Empirical results indicate that there is a significant negative correlation between Internet use and people's food safety evaluation in China. Furthermore, heterogeneity analysis shows that Internet use has a stronger negative correlation with food safety evaluation for those lacking rational judgment regarding Internet information. Specifically, the negative correlation between Internet use and food safety evaluations is more obvious among rural residents, young people, and less educated residents. Finally, propensity score matching (PSM) is applied to conduct a robustness check. This paper provides new evidence for studies on the relationship between Internet use and an individuals' food safety cognition, as well as additional policy enlightenment for food safety risk management in the digital age.

17.
Water Environ Res ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31642152

RESUMO

The nitrogen (N) release from composted and un-composted biosolids and plant available N (PAN) of the biosolids were quantified to evaluate if composting can contribute to stabilize biosolids N and reduce the nitrate ( NO 3 - ) leaching potential in biosolids-amended soil. Biosolids were composted at >55°C for 21 days after mixing the biosolids with yard waste at 1:1 (w/w) ratio. In the N release study, we installed field lysimeters filled with soil (sand and clay) amended with composted and un-composted biosolids at two rates (30 and 150 dry Mg/ha) and measured the inorganic N in leachate after each rainfall and soil inorganic N monthly. The N released from composted biosolids during the two-year study period were lower (6% of organic N added for clay and 11% for sandy loam soil) as compared to un-composted biosolids (14% of organic N added for clay and 21% for sandy soils). Composted biosolids showed a lower N release rate constant k value of 0.0014 and 0.0027 month-1 for clay and sandy soil, respectively, compared to corresponding values of 0.0035 and 0.0068 month-1 for un-composted biosolids. We used greenhouse bioassay with corn (Zea mays), ryegrass (Lolium perenne), and Miscanthus (Miscanthus giganteus) as test plants grown for six months with reference to N chemical fertilizer ranging from 0, 75, 150 to 300 kg N/ha to evaluate the PAN of the biosolids. Based on our study, plant growth was not affected by using either composted or un-composted biosolids but the PAN was lower in composted biosolids (4.0%-5.9%) than un-composted biosolids (11.4%-13.6%). Composting results in higher N-retention efficiency in biosolids and composted biosolids are a valuable source of N to support the plant growth with lower N released to the environment. Thus, the potential of N leaching would still be low in the situations where a high rate of biosolids needs to be applied for land reclamation or landscaping soil reconstruction. PRACTITIONER POINTS: Composting enhances N-retention efficiency in biosolids and composted biosolids are a valuable source of N to support the plant growth with lower N released to the environment. Potential of N leaching would still be low in the situations where a high rate of biosolids needs to be applied for land reclamation or landscaping soil reconstruction. N released from composted and un-composted biosolids can be adequately described by first-order kinetic model.

18.
J Am Chem Soc ; 141(43): 17133-17141, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31580665

RESUMO

Temporal and reversible control over protein and cell conjugations holds great potential for traceless release of antibody-drug conjugates (ADCs) on tumor sites as well as on-demand altering or removal of targeting elements on cell surface. We herein developed a bioorthogonal and traceless releasable reaction on proteins and intact cells to fulfill such purposes. A systematic survey of transition metals in catalyzing the bioorthogonal cleavage reactions revealed that copper complexes such as Cu(I)-BTTAA and dual-substituted propargyl (dsPra) or propargyloxycarbonyl (dsProc) moieties offered a bioorthogonal releasable pair for reversible blockage and rescue of primary amines and phenol alcohols on small molecule drugs, protein side chains, as well as intact cell surface. For proof-of-concept, we employed such Cu(I)-BTTAA/dsProc and Cu(I)-BTTAA/dsPra pairs as a "traceless linker" strategy to construct cleavable ADCs to unleash cytotoxic compounds on cancer cells in situ and as a "reversible modification" strategy for cell surface engineering. Furthermore, by coupling with the genetic code expansion strategy, we site-specifically modulated ligand-receptor interactions on live cell membranes. Together, our work expanded the transition-metal-mediated bioorthogonal cleavage tool kit from terminal decaging to internal-linker breakage, which offered a temporal and reversible conjugation strategy on therapeutic proteins and cells.

19.
J Biol Chem ; 294(47): 17863-17874, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31624145

RESUMO

Long noncoding RNAs (lncRNAs) modulate gene expression as competing endogenous RNAs (ceRNAs) that sponge regulatory microRNAs (miRNAs). During cellular reprogramming, genes associated with pluripotency establishment need to be up-regulated, and developmental genes need to be silenced. However, how ceRNAs control cellular reprogramming still awaits full elucidation. Here, we used doxycycline-inducible expression of the four transcription factors octamer-binding protein 4 (OCT4), SRY-box 2 (SOX2), Krüppel-like factor 4 (KLF4), and proto-oncogene c-Myc (c-Myc) to generate induced pluripotent stem cells (iPSCs) from mouse embryonic fibroblasts (MEFs). Using RNA-Seq and bioinformatics approaches, we found that the expression levels of miRNAs from MEFs remain high from day 0 to 6 after the doxycycline induction. Many genes targeted by these miRNAs were up-regulated, and long intergenic noncoding RNAs (lincRNAs) and circular RNAs (circRNAs), which have complementary binding sites to these miRNAs, were highly expressed, indicating lincRNAs and circRNAs may function as ceRNAs. Intriguingly, knockdown of the linc/circRNAs that sponge the miRNAs, which target OCT4 down-regulated exogenous OCT4, decreased reprogramming efficiency, and resulted in low-grade iPSCs. Our results suggest that the ceRNA network plays an important role in cellular reprogramming.

20.
ACS Nano ; 13(10): 11433-11442, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31539472

RESUMO

Quantum-dot light-emitting diodes (QLEDs) with high brightness have potential application in lighting and display. The high brightness is realized at high current density (J). However, at high J, the efficiency drops significantly, thereby limiting the achievable brightness. This notorious phenomenon has been known as efficiency roll-off, which is likely caused by the Auger- and/or thermal-induced emission quenching. In this work, we show that the Joule heat generated during device operation significantly affects the roll-off characteristics of QLEDs. To realize ultrabright and efficient QLEDs, the thermal stability of QDs is improved by replacing the conventional oleic acid ligands with 1-dodecanethiol. By further using a substrate with high thermal conductivity, the Joule heat generated at high J is effectively dissipated. Because of the effective thermal management, thermal-induced emission quenching is significantly suppressed, and consequently, the QLEDs exhibit a high external quantum efficiency (EQE) of 16.6%, which is virtually droop-free over a wide range of brightness (e.g., EQE = 16.1% @ 105 cd/m2 and 140 mA/cm2). Moreover, due to the reduced efficiency roll-off and enhanced heat dissipation, the demonstrated QLEDs can be operated at a very high J up to 3885 mA/cm2, thus enabling the devices to exhibit a record-high brightness of 1.6 × 106 cd/m2 and a lumen density of 500 lm/cm2. Our work demonstrates the significance of thermal management for the development of droop-free and ultrabright QLED devices for a wide variety of applications including lighting, transparent display, projection display, outdoor digital signage, and phototherapy.

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