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1.
Biomed Pharmacother ; 147: 112615, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35026488

RESUMO

Sepsis-induced acute kidney injury (AKI) and acute lung injury (ALI) have high morbidity and mortality, with no effective clinically available drugs. Anti-inflammation is effective strategy in the therapy of AKI and ALI. NF-κB is a target for the development of anti­inflammatory agents. The purpose of the study is to evaluate the effect of 270, self-developed NF-κB inhibitor, in LPS-induced AKI and ALI. LPS-induced macrophages were used to examine the anti-inflammation activity of 270 in vitro. Sepsis-induced AKI and ALI mice models were established by intraperitoneal injection of LPS (10 mg/kg) for 24 h. Oral administration 270 for 14 days before LPS stimulation. Plasma, kidney and lung tissues were collected and used for histopathology, biochemical assay, ELISA, RT-PCR, and western blot analyses. In vitro, we showed that 270 suppressed the inflammation response in LPS-induced RAW 264.7 macrophages and bone marrow derived macrophages. In vivo, we found that 270 ameliorated LPS-induced AKI and ALI, as evidenced by improving various pathological changes, reducing the expression of pro-inflammation genes, blocking the activation of NF-κB and JNK pathways, attenuating the elevated myeloperoxidase (MPO) activity and malondialdehyde (MDA) content, ameliorating the activated ER stress, reversing the inhibition effect on autophagy in kidney and lung tissues, and alleviating the enhanced plasma level of creatinine (Crea), blood urea nitrogen (BUN) and pro-inflammation cytokines. Our investigations provides evidence that NF-κB inhibitor 270 is a potential drug that against LPS-induced AKI and ALI in the future.

2.
Nat Commun ; 13(1): 84, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013298

RESUMO

Axially chiral styrenes bearing a chiral axis between a sterically non-congested acyclic alkene and an aryl ring are difficult to prepare due to low rotational barrier of the axis. Disclosed here is an N-heterocyclic carbene (NHC) catalytic asymmetric solution to this problem. Our reaction involves ynals, sulfinic acids, and phenols as the substrates with an NHC as the catalyst. Key steps involve selective 1,4-addition of sulfinic anion to acetylenic acylazolium intermediate and sequential E-selective protonation to set up the chiral axis. Our reaction affords axially chiral styrenes bearing a chiral axis as the product with up to > 99:1 e.r., > 20:1 E/Z selectivity, and excellent yields. The sulfone and carboxylic ester moieties in our styrene products are common moieties in bioactive molecules and asymmetric catalysis.

3.
Bioengineered ; 13(1): 1025-1038, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34968167

RESUMO

Previous studies have confirmed that microRNA (miR)-128-3p is expressed at low levels in gastric cancer (GC), and low miR-128-3p expression promotes the growth of GC cells. However, whether the dysregulation of miR-128-3p expression affects tumor-infiltrating lymphocytes (TILs) and leads to immune escape remains unclear. In the present study, predictive bioinformatics approaches showed that miR-128-3p expression was inversely correlated with tumor-infiltrating lymphocyte enrichment. When CD4 + T cells and regulatory T cells (Tregs) were enriched, lower miR-128-3p expression was associated with worse overall survival. However, when numbers of CD8 + T cells were decreased, the upregulation of miR-128-3p expression had a favorable effect on GC prognosis. Dual-luciferase reporter assays and cell biology experiments revealed that interleukin 16 (IL16) was the target of miR-128-3p and was negatively regulated by miR-128-3p. In addition, GC cells were cocultured with T lymphocytes, and the subsequent flow cytometric analysis showed that overexpression of miR-128-3p in tumor cells decreased the percentages of CD4+ CD25+ Foxp3+ Tregs by downregulating IL16 expression in GC, whereas miR-128-3p inhibition had the opposite effect. Moreover, the recombinant IL16 reversed the effects of miR-128-3p overexpression, and a competitive antibody against the IL16 receptor CD4 also reversed the effects of miR-128-3p knockdown. These studies identified the mechanism by which the miR-128-3p/IL16 axis promotes the infiltration of CD4+ Tregs in GC, and this mechanism will be a promising therapeutic target in GC immunotherapy.

4.
J Microbiol Methods ; 192: 106393, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34919971

RESUMO

Due to the abuse of antibiotics, the prevalence of antibiotic resistant Helicobacter pylori strains continues to increase. Therefore, antibiotic resistance assessment is now essential in addition to general H. pylori diagnosis in medical institutions to fulfill clinicians administering effective antibiotic regimens. However, the conventional antibiotic resistance assessment methods, such as in vitro antibiotic susceptibility test and E-test, are skilled-staff dependent and time-consuming. The aim of this study was to establish an easy-operating TaqMan-MGB probe multiplex real-time PCR system for one-step detection of levofloxacin and clarithromycin resistance mutations with concurrent H. pylori infection diagnosis. Through the optimization of primers, probes and reaction buffers, this proposed system could accurately distinguish the recombinant plasmids with different mutation markers. More importantly, the diagnosis results of this detection system exhibited excellent consistence with the gold standard of gastric biopsy and Sanger sequencing on the detection of H. pylori infection and relevant antibiotic resistant strains, the Kappa values of which all exceeded 0.90. In addition, the results of this detection system could also be applied for the prevalence statistics of antibiotic resistance patterns for patients by age, gender and geographical location. This simple and rapid system should be beneficial for clinicians issuing personalized treatments according to the patient's H. pylori strains and avoid the abuse of antibiotics.

5.
Int J Infect Dis ; 115: 245-255, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34910955

RESUMO

BACKGROUND: The aim of this study was to evaluate the long-term sequelae and cognitive profiles resulting from severe hand, foot, and mouth disease (HFMD) with central nervous system (CNS) involvement. METHODS: 294 HFMD cases were included in a retrospective follow-up study. Physical examinations were conducted. The Chinese Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) was used to assess intelligence. RESULTS: 58 mild HFMD cases and 99 severe HFMD cases with mild CNS involvement did not present any neurological sequelae. In comparison, the sequelae incidence for severe HFMD with more severe CNS complications was 50.0%. The proportion of full-scale intelligence quotient (FSIQ) impairment was 45.0%. In the 2:6-3:11 age group, severe HFMD with more severe CNS complications and lower maternal education level were risk factors for verbal comprehension disorder. Urban-rural residence and lower paternal education level were risk factors for FSIQ disorder. Furthermore, in the 4:0-6:11 age group, severe HFMD with more severe CNS complication was a risk factor for visual spatial disorder and fluid reasoning disorder. Lower paternal education level was a risk factor for FSIQ disorder. CONCLUSION: Early assessment and intervention among severe HFMD patients with more severe CNS involvement at a very young age will prove beneficial for their future performance.


Assuntos
Doença de Mão, Pé e Boca , Pré-Escolar , China/epidemiologia , Seguimentos , Doença de Mão, Pé e Boca/complicações , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Incidência , Lactente , Estudos Retrospectivos
6.
Shanghai Kou Qiang Yi Xue ; 30(5): 504-510, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34888603

RESUMO

PURPOSE: To understand oral health professionals' knowledge, attitude, behavior and training needs related to clinical research, and explore relevant factors affecting clinical research knowledge level. METHODS: An online self-designed questionnaire was conducted among oral health professionals from the collaborative innovation network member units of the National Clinical Research Center for Oral Diseases (Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine). The data were processed with SAS 9.4 software package. RESULTS: A total of 281 oral health professionals were enrolled in the study. Most of them had a positive attitude towards clinical research, 80% of them had an idea of carrying out clinical research, while only 22.8% of them implemented finally. The main causes restricting oral health professionals from conducting clinical research were lack of time (68.3%), insufficient teams (63.7%), and short of financial support (60.9%). Participants' mean score of clinical research knowledge was (13.72±7.20) points. Multiple linear regression model showed the type of hospital, clinical research participation in the past five years and epidemiologists' or statisticians' involvement in the latest project were related to participants' knowledge level of clinical research. CONCLUSIONS: Oral health professionals have a positive attitude towards clinical research, while their behavior and knowledge about clinical research were weak. Strengthening the top design of clinical research is inseparable from the cultivation of professionals' clinical research ability. The national clinical research center should give full play to the mission of the "national team", accelerate the establishment of a specialized, normalized and large-scale clinical research training pattern, and provide training opportunities to network member units.

7.
Shanghai Kou Qiang Yi Xue ; 30(5): 511-516, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34888604

RESUMO

PURPOSE: To analyze the characteristics of clinical trials of mucosal melanoma (MM) based on WHO international clinical trial registration platform (ICTRP), in order to provide a reference for clinical translational research of mucosal melanoma. METHODS: WHO ICTRP database were searched to collect MM-related clinical trials. Two reviewers independently screened items, extracted data, and descriptive analysis was performed for the included trials, including number of registrations, research phase, country/region, clinical study design, etc. RESULTS: The results showed that there were 51 registered clinical trials involving MM. European and American countries and East Asia were the main study sites, and head and neck MM were mainly investigated in East Asia (11/12). Forty-eight of them were sponsored by investigators, and only 3 were sponsored by biomedical companies. The main clinical trials were single center (42 items) and in stage II (38 items). Interventions were complex, and multiple treatments and drug therapy accounted a dominant position. CONCLUSIONS: In-depth analysis of clinical trials information can help to understand the current situation and development trends in the field of mucosal melanoma. The number of clinical studies of mucosal melanoma is relatively small and has not received much attention.

8.
J Environ Radioact ; 242: 106787, 2021 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-34875444

RESUMO

During a nuclear accident, estimating the source terms using environmental measurements is vital for emergency decision-making. In this study, we propose a forecasting model based on a temporal convolutional network to estimate the release rates of seven radionuclides (Kr-88, Te-132, I-131, Xe-133, Cs-137, Ba-140, and Ce-144) based on off-site sequential gamma dose rates and meteorological monitoring data. To determine the best structure of the neural network, Bayesian optimization and hyperband (BOHB) was used on the hyperparameters of the model to reduce the testing loss. Additionally, a gradient boosting regression model was used to predict missing gamma dose rates to ensure the model offers a relatively reliable estimate under certain circumstances. The international radiological assessment system (InterRAS) was used to generate datasets for model training and testing. The results showed that the optimal hyperparameters selected by BOHB can reduce the valid loss of the model to 0.0153, and the mean absolute percentage error of prediction for the seven radionuclides was below 12%, three of which (Kr-88, Te-132, Cs-137) reached 8% at 10 h. When the first and second time-steps of the data were missing, the mean absolute percentage error of the prediction for all radionuclides was less than 30% after using a gradient boosting regression.

9.
Aging (Albany NY) ; 13(24): 25607-25642, 2021 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-34968192

RESUMO

Aging is accompanied by osteopenia, characterized by reduced bone formation and increased bone resorption. Osteocytes, the terminally differentiated osteoblasts, are regulators of bone homeostasis, and parathyroid hormone (PTH) receptor (PPR) signaling in mature osteoblasts/osteocytes is essential for PTH-driven anabolic and catabolic skeletal responses. However, the role of PPR signaling in those cells during aging has not been investigated. The aim of this study was to analyze the role of PTH signaling in mature osteoblasts/osteocytes during aging. Mice lacking PPR in osteocyte (Dmp1-PPRKO) display an age-dependent osteopenia characterized by a significant decrease in osteoblast activity and increase in osteoclast number and activity. At the molecular level, the absence of PPR signaling in mature osteoblasts/osteocytes is associated with an increase in serum sclerostin and a significant increase in osteocytes expressing 4-hydroxy-2-nonenals, a marker of oxidative stress. In Dmp1-PPRKO mice there was an age-dependent increase in p16Ink4a/Cdkn2a expression, whereas it was unchanged in controls. In vitro studies demonstrated that PTH protects osteocytes from oxidative stress-induced cell death. In summary, we reported that PPR signaling in osteocytes is important for protecting the skeleton from age-induced bone loss by restraining osteoclast's activity and protecting osteocytes from oxidative stresses.

10.
Foods ; 10(12)2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34945598

RESUMO

In this study, thymoquinone (TQ), a natural active substance, was investigated for its antibacterial activity against Bacillus cereus, and its inhibitory effect on B. cereus in reconstituted infant formula (RIF) was evaluated. In addition, the inhibitory effect of TQ on B. cereus spore germination was explored. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of TQ against eight B. cereus strains ranged from 4.0 to 8.0 µg/mL, whereas B. cereus treated with TQ displayed a longer lag phase than the untreated control. TQ exerted a good bactericidal effect on B. cereus in Luria-Bertani broth. In addition, TQ obviously reduced the intracellular ATP concentration of B. cereus, which caused depolarization of the cell membrane, increased the intracellular reactive oxygen species level, impaired the cell morphology, and destroyed proteins or inhibited proteins synthesis. This provides a mechanism for its bacteriostatic effect. TQ also inactivated B. cereus growth in RIF. Moreover, reverse transcription-quantitative polymerase chain reaction illustrated that TQ downregulated the transcription of genes related to hemolysin, non-hemolytic enterotoxin, enterotoxin, and cytotoxin K. Meanwhile, TQ displayed the ability to inhibit the germination of B. cereus spores. These findings indicate that TQ, as an effective natural antimicrobial preservative, has potential applications in controlling food contamination and foodborne diseases caused by B. cereus.

11.
Zhonghua Nan Ke Xue ; 27(1): 45-49, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-34914280

RESUMO

Objective: To study the effects of 1470 nm semiconductor laser enucleation of the prostate (SCLEP) and transurethral plasma electrotomy (TUPE) on erectile function and pelvic floor muscle strength in BPH patients. METHODS: We retrospectively analyzed the clinical data on 72 cases of BPH treated in our hospital from July 2017 to July 2019 by TUPE (group A, n = 36) or 1470 nm SCLEP (group B, n = 36). We observed and compared the postoperative penile erectile function, retrograde ejaculation and pelvic floor muscle strength between the two groups of patients. RESULTS: Compared with group A, group B showed a significantly higher IIEF-5 score (19.43 ± 1.61 vs 21.15 ± 1.32, P < 0.05) and pelvic floor muscle strength (electromyographic ï¼»EMGï¼½ value) during rapid contraction (36.36 ± 1.38 vs 43.53 ± 2.04, P < 0.05), continuous contraction (34.27 ± 1.63 vs 39.46 ± 1.48, P < 0.05) and endurance test (35.24 ± 1.57 vs 38.19 ± 1.67, P < 0.05), but lower incidence rates of ED and retrograde ejaculation. CONCLUSIONS: Compared with TUPE, 1470 nm SCLEP affects less the erectile function and pelvic floor muscle strength of BPH patients.


Assuntos
Disfunção Erétil , Hiperplasia Prostática , Disfunção Erétil/etiologia , Humanos , Lasers Semicondutores , Masculino , Força Muscular , Diafragma da Pelve/cirurgia , Próstata , Hiperplasia Prostática/cirurgia , Estudos Retrospectivos , Volatilização
12.
Foods ; 10(12)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34945505

RESUMO

Foodborne Staphylococcus aureus (S. aureus) has attracted widespread attention due to its foodborne infection and food poisoning in human. Shikonin exhibits antibacterial activity against a variety of microorganisms, but there are few studies on its antibacterial activity against S. aureus. This study aims to explore the antibacterial activity and mechanism of shikonin against foodborne S. aureus. The results show that the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of shikonin were equal for all tested strains ranging from 35 µg/mL to 70 µg/mL. Shikonin inhibited the growth of S. aureus by reducing intracellular ATP concentrations, hyperpolarizing cell membrane, destroying the integrity of cell membrane, and changing cell morphology. At the non-inhibitory concentrations (NICs), shikonin significantly inhibited biofilm formation of S. aureus, which was attributed to inhibiting the expression of cidA and sarA genes. Moreover, shikonin also markedly inhibited the transcription and expression of virulence genes (sea and hla) in S. aureus. In addition, shikonin has exhibited antibacterial ability against both planktonic and biofilm forms of S. aureus. Importantly, in vivo results show that shikonin has excellent biocompatibility. Moreover, both the heat stability of shikonin and the antimicrobial activity of shikonin against S. aureus were excellent in food. Our findings suggest that shikonin are promising for use as a natural food additive, and it also has great potential in effectively controlling the contamination of S. aureus in food and reducing the number of illnesses associated with S. aureus.

13.
Anal Biochem ; 635: 114445, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740597

RESUMO

The outbreak of COVID-19 makes epidemic prevention and control become a growing global concern. Nucleic acid amplification testing (NAAT) can realize early and rapid detection of targets, thus it is considered as an ideal approach for detecting pathogens of severe acute infectious diseases. Rapid acquisition of high-quality target nucleic acid is the prerequisite to ensure the efficiency and accuracy of NAAT. Herein, we proposed a simple system in which magnetic nanoparticles (MNPs) based nucleic acid extraction was carried out in a plastic Pasteur pipette. Different from traditional approaches, this proposed system could be finished in 15 min without the supports of any electrical instruments. Furthermore, this system was superior to traditional MNPs based extraction methods in the aspects of rapid extraction and enhancing the sensitivity of a NAAT method, accelerated denaturation bubbles mediated strand exchange amplification (ASEA), to the pathogens from various artificial samples. Finally, this Pasteur pipette system was utilized for pathogen detection in actual samples of throat swabs, cervical swabs and gastric mucosa, the diagnosis results of which were identical with that provided by hospital. This rapid, easy-performing and efficiency extraction method ensures the applications of the NAAT in pathogen detection in regions with restricted resources.

14.
Chem Sci ; 12(41): 13809-13816, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34760166

RESUMO

Highly efficient triplet photosensitizers (PSs) have attracted increasing attention in cancer photodynamic therapy where photo-induced reactive oxygen species (ROSs, such as singlet oxygen) are produced via singlet-triplet intersystem crossing (ISC) of the excited photosensitizer to kill cancer cells. However, most PSs exhibit the fatal defect of a generally less-than-1% efficiency of ISC and low yield of ROSs, and this defect strongly impedes their clinical application. In the current work, a new strategy to enhance the ISC and high phototherapy efficiency has been developed, based on the molecular design of a thio-pentamethine cyanine dye (TCy5) as a photosensitizer. The introduction of an electron-withdrawing group at the meso-position of TCy5 could dramatically reduce the singlet-triplet energy gap (ΔE st) value (from 0.63 eV to as low as 0.14 eV), speed up the ISC process (τ ISC = 1.7 ps), prolong the lifetime of the triplet state (τ T = 319 µs) and improve singlet oxygen (1O2) quantum yield to as high as 99%, a value much higher than those of most reported triplet PSs. Further in vitro and in vivo experiments have shown that TCy5-CHO, with its efficient 1O2 generation and good biocompatibility, causes an intense tumor ablation in mice. This provides a new strategy for designing ideal PSs for cancer photo-therapy.

15.
Adv Mater ; : e2106797, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34761453

RESUMO

Conventional photosensitizers (PSs) often show poor tumor retention and are rapidly cleared from the bloodstream, which is one of the key hindrances to guarantee precise and efficient photodynamic therapy (PDT) in vivo. In this work, we present a photosensitizer assembly nanosystem that sharply enhances tumor retention up to ∼10 days. The PSs are synthesized by meso-substituting anthracene onto the BODIPY scaffold (AN-BDP), which then self-assemble into stable nanoparticles (AN-BDP NPs) with amphiphilic block copolymers due to the strong intermolecular π-π interaction of anthracene. Additionally, the incorporated anthracene excites the PSs, producing singlet oxygen under red light irradiation. Although AN-BDP NPs could completely suppress regular test size tumor (∼100 mm3 ) by one-time radiation, only 12% tumour growth inhibition rate was observed in the case of large size tumor (∼350 mm3 ) under the same conditions. Due to the long time tumor retention, AN-BDP NPs allows single-dose injection and three-time light treatments, resulting in an over 90% inhibition rate, much more efficient than single-time radiation of conventional clinically used PSs including chlorin (Ce6) and porphyrin with poor tumor retention. The results reveal the importance of long tumor retention time of PSs for efficient PDT, which can accelerate the clinical development of nanophotosensitizers. This article is protected by copyright. All rights reserved.

16.
mSystems ; : e0097921, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34726492

RESUMO

When facing a food shortage, generalist herbivores can respond by expanding their dietary species richness (DSR) to maximize energy collection, regardless of whether forages are preferred or not. Higher DSR usually indicates higher nutrient adequacy and better health. However, the high-DSR diet containing a large proportion of preferred species or a large proportion of less-preferred species means different things to an animal. It is still unknown how different shift patterns in DSR would affect distinctly the performance of animals via altering gut microbiota. We examined the gut microbial composition, diversity, community assembly processes, and performance of a generalist herbivore, Lasiopodomys brandtii, in a feeding experiment with increased levels of simulated DSR shifting from preferred plant species to less preferred ones. We found the survival rate and body growth of Brandt's voles showed a dome-shaped association with DSR: species performance increased initially with the increase of preferred plant species but declined with the increase of less-preferred food items. Several microbial taxa and functions closely related to the metabolism of amino acids and short-chain fatty acids also showed a dome-shaped association with DSR, which is consistent with the observation of performance change. However, the alpha diversities of gut microbiota increased linearly with DSR. The null model and phylogenetic analysis suggested that stochastic processes dominate at low DSR diets, whereas deterministic processes prevail at high DSR diets. These results suggest that the role of DSR in regulating animal performance by gut microbiota depends on the number of preferred forage items. IMPORTANCE The plant species diversity varies greatly under the influence of both climate change and human disturbance, which may negatively affect the productivity as well as the variability of organisms (e.g., small herbivores) at the next trophic level. It is still unknown how gut microbiota of small herbivores respond to such changes in dietary species richness. Our manipulative food experiment revealed that dietary species richness can affect the composition, functions, and community assembly of gut microbiota of Brandt's vole in a nonlinear way. Given the fast-growing interest in therapeutic diets to treat dysbiosis and to improve health conditions, our study highlights the need to consider not just the variety of consumed food but also the principles of rational nutrition.

17.
Dalton Trans ; 50(44): 16304-16310, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34730578

RESUMO

In view of the fact that coordination configurations and special functional groups are both important for the optical properties of phosphorescent iridium complex materials, we have prepared a novel family of three types of charged ligand (0, -1, and -2) based neutral phosphorescent iridium(III) complexes (Ir1-Ir4) featuring nido-carborane. Single crystal structures indicate that complexes (Ir2, Ir3 and Ir4) with nido-carborane as a functional group at different substitution sites all show a trans-C^C configuration between dianionic (-2) and monoanionic (-1) ligands, which are different from the trans-N^C configuration in complex Ir1 with nido-carborane as a coordination skeleton, which has an interesting Ir-B coordination bond. Notably, Ir2, Ir3 and Ir4 all show obvious yellow light emission, while Ir1 does not emit light either in solution or in the solid state. DFT calculations demonstrate that complexes Ir2, Ir3 and Ir4 exhibit an unusual ligand-to-metal charge transfer (LMCT) excited state character due to the strong electron-donating character of nido-carborane. Considering its better solubility and luminescence properties, Ir3 was successfully applied in solution-processed organic light-emitting diodes and an effective yellow emission was achieved. This work provides a new strategy for the investigation of three types of charged ligand (0, -1, and -2) based phosphorescent iridium complex materials by constructing new dianionic ligands with nido-carborane.

18.
Chemistry ; 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34730859

RESUMO

A series of [-2, -1, 0] charged-ligand based iridium(III) complexes of [Ir(bph)(bpy)(acac)] (1), [Ir(bph)(2MeO-bpy)(acac)] (2), [Ir(bph)(2CF3 -bpy)(acac)] (3), [Ir(bph)(bpy)(2t Bu-acac)] (4) and [Ir(bph)(bpy)(CF3 -acac)] (5), which using biphenyl as dianionic ligand [-2], acetylacetone (or its derivatives) as monoanionic ligand [-1], and 2,2'-bipyridine (or its derivatives) as neutral ligand [0] were designed and synthesized. The chemical structures were well characterized. All of the ligands have simple chemical structures, thus further making the complexes have excellent thermal stability and are easy to sublimate and purify. Phosphorescent characteristics with short emission lifetime were demonstrated for these emitters. Notably, all of the complexes exhibit remarkable deep red/near infrared emission, which is quite different from the reported [-1, -1, -1] charged-ligand based iridium(III) complexes. The photophysical properties of these complexes are regularly improved by introducing electron-donating or -withdrawing groups into [-1] or [0] charged-ligand. The related organic light-emitting diodes exhibited deep red/near infrared emission with acceptable external quantum efficiency and low turn-on voltage (<2.6 V). This work provides a new idea for the construction of new type phosphorescent iridium(III) emitters with different valence states of [-2, -1, 0] charged ligands, thus offering new opportunities and challenges for their optoelectronic applications.

19.
Nat Commun ; 12(1): 6331, 2021 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-34732724

RESUMO

Hydrogels have been extensively used in many fields. Current synthesis of functional hydrogels requires incorporation of functional molecules either before or during gelation via the pre-organized reactive site along the polymer chains within hydrogels, which is tedious for polymer synthesis and not flexible for different types of hydrogels. Inspired by sandcastle worm, we develop a simple one-step strategy to functionalize wet hydrogels using molecules bearing an adhesive dibutylamine-DOPA-lysine-DOPA tripeptide. This tripeptide can be easily modified with various functional groups to initiate diverse types of polymerizations and provide functional polymers with a terminal adhesive tripeptide. Such functional molecules enable direct modification of wet hydrogels to acquire biological functions such as antimicrobial, cell adhesion and wound repair. The strategy has a tunable functionalization degree and a stable attachment of functional molecules, which provides a tool for direct and convenient modification of wet hydrogels to provide them with diverse functions and applications.

20.
Inorg Chem ; 60(23): 17699-17704, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34739254

RESUMO

A novel family of three types of charged (0, -1, -2) ligands based phosphorescent iridium(III) complexes with different carboxyl-containing dianionic (-2) ligands have been synthesized. Their single-crystal structures show that all neutral complexes (Ir1, Ir2, and Ir3) show a trans-N^N configuration between dianionic (-2) and monoanionic (-1) ligands, which is in contrast with the trans-N^C configuration in cationic complex Ir4, which has an interesting hydrogen bond in the solid state. Notably, Ir4 shows higher luminescence efficiency and an obvious blue shift emission relative to those in Ir1, Ir2, and Ir3. DFT calculations demonstrate that all neutral complexes (Ir1, Ir2, and Ir3) exhibit ligand-to-ligand charge transfer (LLCT) excited state character from the dianionic (-2) ligand to the neutral (0) ligand, which are completely different from the cationic complex Ir4 that exhibits an LLCT excited state from the monoanionic (-1) ligand to the neutral (0) ligand. Considering better solubility, Ir1 was eventually used in solution-processed OLED and achieved moderate efficiency (6.6%, 14.3 cd A-1, 2.8 lm W-1) with an orange light displaying CIEx,y coordinates of (0.53, 0.46). This work provides a new strategy to construct three types of charged (0, -1, -2) ligands based phosphorescent iridium(III) complexes and extends the range of iridium complex luminescent materials.

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