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1.
Chem Commun (Camb) ; 56(9): 1405-1408, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31912829

RESUMO

Heteroatoms were introduced as a novel modification strategy for fine-tuning the diradical character of molecular systems. Both the diradical character and the singlet-triplet energy gaps of diketopyrrolopyrrole based phenoxyl diradicaloids decreased as the size of the substituted heteroatoms (from O, S to Se atom) increased.

2.
J Cell Mol Med ; 24(4): 2451-2463, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31957265

RESUMO

This study sought to find more exon mutation sites and lncRNA candidates associated with type 2 diabetes mellitus (T2DM) patients with obesity (O-T2DM). We used O-T2DM patients and healthy individuals to detect mutations in their peripheral blood by whole-exon sequencing. And changes in lncRNA expression caused by mutation sites were studied at the RNA level. Then, we performed GO analysis and KEGG pathway analysis. We found a total of 277 377 mutation sites between O-T2DM and healthy individuals. Then, we performed a DNA-RNA joint analysis. Based on the screening of harmful sites, 30 mutant genes shared in O-T2DM patients were screened. At the RNA level, mutations of 106 differentially expressed genes were displayed. Finally, a consensus mutation site and differential expression consensus gene screening were performed. In the current study, the results revealed significant differences in exon sites in peripheral blood between O-T2DM and healthy individuals, which may play an important role in the pathogenesis of O-T2DM by affecting the expression of the corresponding lncRNA. This study provides clues to the molecular mechanisms of metabolic disorders in O-T2DM patients at the DNA and RNA levels, as well as biomarkers of the risk of these disorders.

3.
J Agric Food Chem ; 68(5): 1248-1256, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31927921

RESUMO

Lipophenols are regarded as an emerging source of functional food ingredients. However, little is known about their in vivo digestion, absorption, and metabolism. Thus, the pharmacokinetic characteristics in rat and the gut microbial degradation of tyrosol acyl esters (TYr-Es) with fatty acids of C12:0, C18:0, and C18:2 were investigated for the first time. Major metabolites including tyrosol sulfate and tyrosol glucuronide, rather than the parent compounds, were detected in rat plasma after oral administration of TYr-Es. The increased plasma half-life (T1/2) and mean residence time demonstrated that TYr-Es display a longer duration of action in vivo than TYr, potentially leading to higher oral bioavailability. TYr-Es could be hydrolyzed by the gut microbiota to free TYr, which may result in the appearance of the second absorption peak in pharmacokinetic profiles. Therefore, TYr-Es exhibit improved bioavailability compared to that of TYr because of their prolonged duration of action.


Assuntos
Ésteres/farmacocinética , Álcool Feniletílico/análogos & derivados , Animais , Disponibilidade Biológica , Ésteres/química , Ácidos Graxos/sangue , Ácidos Graxos/química , Cinética , Masculino , Álcool Feniletílico/química , Álcool Feniletílico/farmacocinética , Plasma/química , Ratos , Ratos Sprague-Dawley
4.
Adv Mater ; 32(4): e1906122, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31782561

RESUMO

It is generally believed that the photoresponse behavior of organic field-effect transistors (OFETs) reflects the intrinsic property of organic semiconductors. However, this photoresponse hinders the application of OFETs in transparent displays as driven circuits due to the current instability resulting from the threshold voltage shift under light illumination. It is necessary to relieve the photosensitivity of OFETs to keep the devices stable. 2,6-diphenyl anthracene thin-film and single-crystal OFETs are fabricated on different substrates, and it is found that the degree of molecular order in the conducting channels and the defects at the dielectric/semiconductor interface play important roles in determining the phototransistor performance. When highly ordered single-crystal OFETs are fabricated on polymeric substrates with low defects, the photosensitivity (P) decreases by more than 105 times and the threshold voltage shift (ΔVT ) is almost eliminated compared with the corresponding thin-film OFETs. This phenomenon is further verified by using another three organic semiconductors for similar characterizations. The decreased P and ΔVT of OFETs ensure a good current stability for OFETs to drive organic light-emitting diodes efficiently, which is essential to the application of OFETs in flexible and transparent displays.

5.
Food Funct ; 11(1): 1037-1048, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31819934

RESUMO

Acerola polysaccharides (ACPs) were purified from acerola (Malpighia emarginata DC.), a tropical fruit with strong antioxidant and anti-inflammatory activities. However, the biological activities of ACPs have barely been investigated. The present study was designed to investigate the efficacy of ACPs in the treatment of high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) in C57BL/6 mice. Male C57BL/6 mice were fed with a high-fat diet and treated with different doses of ACPs for 9 continuous weeks. NAFLD was examined in terms of body weight, lipid profiles, liver function markers, and histology. Gene expression was determined by using both qRT-PCR and western blot. Our results showed that administration of ACPs significantly reduced HFD-induced hyperlipidemia and hepatic lipid deposition by inhibiting the SREBP1c pathway in mice. ACP treatment normalized oxidative stress by activating nuclear factor (erythroid-derived-2)-like 2 (Nrf2) and reduced the expressions of pro-inflammatory cytokines in HFD fed mice. Furthermore, ACPs reduced uncoupling protein 2 (UCP2) expression, restored mitochondrial ATP content, increased mitochondrial complex I, IV, and V activity, and increased mitochondrial beta-oxidation by stimulating peroxisomal proliferator-activated receptor-gamma coactivator-1α (PGC-1α) in the liver of HFD-fed mice. Our study indicated that ACPs may be an effective dietary supplement for preventing HFD-induced NAFLD by regulating lipogenesis, reducing inflammation and oxidative stress, and promoting the mitochondrial function.

6.
Food Chem ; 308: 125650, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655477

RESUMO

This study aimed at investigating the formation and accumulation of 16 reactive aldehydes in clam (Ruditapes philippinarum) during oil frying in both the tissue and the oil using an HPLC-ESI-MS/MS methodology. After processing, the accumulation of acrolein, crotonaldehyde, pentanal, trans-2-hexenal, hexanal, trans, trans-2,4-heptadienal, heptanal, nonanal, trans, trans-2,4-decadienal and 4-hydroxy-2-nonenal was most noticeable in both fried clam and frying oil. Most of the aldehyde species showed a time- and temperature-dependent manner of formation and accumulation during frying due to continuous oxidative degradation under conditions employed. However, several species of aldehyde such as acrolein and trans-2-pentenal slightly decreased at higher temperatures and/or longer frying times, which may be due to the imbalance toward disappearance of aldehydes resulting from their evaporation under the extreme conditions. Presence of natural polyphenols in bamboo leaves significantly prevented the formation of aldehydes in both fried clam and frying oil due to their antioxidant activity (P < 0.05).


Assuntos
Aldeídos/química , Bivalves/química , Animais , Cromatografia Líquida de Alta Pressão , Culinária , Temperatura Alta , Oxirredução , Espectrometria de Massas em Tandem
7.
Nat Sci Sleep ; 11: 291-300, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31807102

RESUMO

Background and aims: Fluvoxamine can markedly increase the serum melatonin level, which regulates human circadian rhythm. However, only limited research has evaluated the effects of fluvoxamine on sleep architecture. Thus, the current study aims to investigate the effect of fluvoxamine on PSG characteristics and the impact of persistent insomnia on the prognosis of depression in the depressed individual with insomnia over the course of 8 weeks. Methods: Thirty-one clinically depressed patients with insomnia were enrolled in this 8-week, open-label, baseline-controlled study, and 23 patients completed the study. All participants were assigned to receive fluvoxamine for 8 weeks. They were assessed by the PSG, Hamilton Rating Scale for Depression (17 items) (HRSD-17), Clinical Global Index, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale at baseline and the following visits, which were at day 14, day 28, and day 56. A patient with an ≥4 HRSD-17 sleep disturbance factor score at both baseline and endpoint (day 56) was defined as a patient with persistent insomnia. Results: Compared with baseline, the percentage of stage 3 sleep had significantly (F=11.630, P=0.001) increased in all 3 visits. Moreover, the percentage of rapid eye movement sleep was reduced during the study, with only a significant difference (F=3.991, P=0.027) between baseline and day 14. Finally, 47.8% (11/23) of the participants were in remission, and 60.9% (14/23) of them did not report insomnia. The clinical remission ratio of the persistent insomnia group (11.1% [1/9]) (χ2 =8.811, P=0.004) was significantly lower than that of the non-insomnia group (71.4% [10/14]) at the endpoint. Additionally, during the first clinical evaluation (day 14), patients without insomnia had significantly higher final remission ratios than patients with insomnia (80% [8/10] versus 30.8% [4/13]; χ2 =5.79; P=0.016). Conclusion: Fluvoxamine improved PSG parameters and ameliorated complaints of insomnia simultaneously during this 8-week study. Moreover, depressed individuals who reported persistent insomnia were at higher risk of remaining depressed by the end of the trial, which might be forecasted by the sleep status on day 14. Trial registration: The Effect of Fluvoxamine on Polysomnogram in Depressed Patients with Insomnia; https://clinicaltrials.gov/ct2/show/NCT02442713. Registry identifier: NCT02442713. Registry date: May 13, 2015.

8.
Fertil Steril ; 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31718828

RESUMO

OBJECTIVE: To compare the effects of metformin, rosiglitazone, and their combination in obese polycystic ovary syndrome (PCOS) patients with insulin resistance. DESIGN: Prospective randomized controlled trail. SETTING: Tertiary teaching hospital. PATIENT(S): Obese Chinese women (body mass index [BMI] ≥25 kg/m2) with insulin resistance who fulfilled the Rotterdam criteria of PCOS. INTERVENTION(S): In group 1, 68 patients administered metformin (1,500 mg/day); in group 2, 67 patients administered rosiglitazone (4 mg/day); in group 3, 69 patients administered metformin (1,000 mg/day) and rosiglitazone (4 mg/day) for 6 months, all with the same diet and regular exercise lifestyle recommendation. MAIN OUTCOME MEASURE(S): Average menstrual interval, anthropometric measurements, androgen-related parameters, and metabolic features of insulin, carbohydrates, and lipids, with intention-to-treat analysis. RESULT(S): The baseline parameters showed no statistically significant differences. After the 6-month treatment, most participants showed an improved menstrual pattern. There were statistically significant decreases in acne scores, weight, BMI, waist circumference, waist-to-hip ratio, and serum testosterone. The metabolic indexes of insulin, carbohydrates, and lipids were improved obviously compared with the baseline in each group. Among the three groups, the patients administered 1,500 mg/day metformin experienced greater reductions in weight. However, the rosiglitazone users (alone or combined with metformin) showed a more notable decline in total cholesterol and triglyceride levels. CONCLUSION(S): Considering the benefits of metformin on weight loss, high-dose metformin (1,500 mg/day) along with lifestyle modification should be recommended for obese, insulin-resistant women with PCOS. Rosiglitazone alone or combined with low-dosage metformin plus lifestyle modification should be considered for the women with abnormal lipid profiles. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR-TRC-13003642 (Chinese Clinical Trial Registry).

9.
Acta Diabetol ; 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31535208

RESUMO

AIMS: To observe the effects of saxagliptin on the expression of mitogen-activated protein kinase 38 (p38MAPK), nephrin and podocin in renal tissue in type 2 diabetic (T2DM) rats, and to explore the possible mechanism of its renal protection. METHODS: Forty-eight male Sprague-Dawley rats were used for the study and divided into four different groups: normal controls (Group NC), DM controls (Group DM), DM + glibenclamide (Group Su) and DM + saxagliptin (Group Sa). The day drug administration started was defined as week 0. After 12 weeks, hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), urea nitrogen (BUN) and creatinine (Cr) in serum were detected, simultaneously albumin and creatinine in urine were measured, respectively, and then urinary albumin/creatinine ratio (UACR) was calculated. The pathological morphology of kidney tissue in different groups was observed, and the expression of nephrin and podocin mRNA and protein in kidney tissue were detected. RESULTS: (1) After 12 weeks, FBG and HbA1c in Group Su and Group Sa were significantly lower than those in Group DM (both P < 0.05), while there was no significant difference between Group Su and Group Sa. TC, TG and UACR in Group Sa were significantly decreased than those in Group DM. (2) When compared with Group DM, the kidney weight/body weight ratios, the average width of glomerular basement membrane and foot process fusion ratio were all improved in Group Sa after 12 weeks. (3) The expression of p38MAPK mRNA and protein was significantly decreased, while nephrin and podocin mRNA and protein were significantly higher in Group Sa than those in Group DM after 12 weeks. (4) A significant negative correlation was detected between p38MAPK mRNA and nephrin (r = - 0.421, P = 0.009) and podocin mRNA (r = - 0.570, P = 0.000), respectively. CONCLUSIONS: Saxagliptin can reduce urinary albumin excretion and exert renal protective effect, especially on podocytes in T2DM rats. The mechanism may be related to its inhibition of renal p38MAPK signaling pathway and the increase in the expression of nephrin and podocin in renal tissue, which is independent of its hypoglycemic effect.

10.
Am J Transl Res ; 11(8): 4667-4682, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31497190

RESUMO

Understanding the relationships between glomerular endothelial cells (GECs) and glomerular mesangial cells (GMCs) is important to identify the molecular mechanisms underlying diabetic nephropathy (DN). Exosomes carried with mRNA, microRNA, and protein play important roles in cell-to-cell communication. In this study, we showed that high glucose (HG)-treated GECs secreted a higher number of exosomes enriched in circRNAs compared with normal glucose (NG)-treated GECs. Differentially expressed circRNAs (DECs) were obtained by high-throughput sequencing. Of these DECs, the expressions of 217 DECs and 484 DECs in HG-treated GEC exosomes were significantly downregulated and upregulated, respectively, compared with NG-treated GEC exosomes. The functions of the DEC target genes were involved in the PI3K/AKT and MAPK pathways. Five DECs were randomly selected for identification by quantitative real-time PCR (qRT-PCR). Two DECs (circRNF169 and circSTRN3) were further selected for functional validation. Moreover, we demonstrated that exosomes released by HG-treated GECs promoted α-smooth muscle actin (α-SMA) expression. It also inhibited proliferation and promoted epithelial-mesenchymal transition (EMT) in GMCs. In addition, cell functional studies indicated that the knockdown and over-expression of two DECs (circRNF169 and circSTRN3) effectively inhibited or promoted cell proliferation and promoted or inhibited EMT, respectively. Thus, the results of this study provide new insights into the pathogenesis of DN that involves the intercellular transfer of circRNAs from GECs to GMCs via exosomes.

11.
Mol Genet Genomic Med ; 7(10): e00928, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31478359

RESUMO

BACKGROUND: ENAM mutations cause autosomal dominant or recessive amelogenesis imperfecta (AI) and show a dose effect: enamel malformations are more severe or only penetrant when both ENAM alleles are defective. METHODS: Whole exome sequences of recruited AI probands were initially screened for mutations in known AI candidate genes. Sanger sequencing was used to confirm sequence variations and their segregation with the disease phenotype. The co-occurrence of ENAM and LAMA3 mutations in one family raised the possibility of digenic inheritance. Enamel formed in Enam+/+ Ambn+/+ , Enam+/- , Ambn+/- , and Enam+/- Ambn+/- mice was characterized by dissection and backscattered scanning electron microscopy (bSEM). RESULTS: ENAM mutations segregating with AI in five families were identified. Two novel ENAM frameshift mutations were identified. A single-nucleotide duplication (c.395dupA/p.Pro133Alafs*13) replaced amino acids 133-1142 with a 12 amino acid (ATTKAAFEAAIT*) sequence, and a single-nucleotide deletion (c.2763delT/p.Asp921Glufs*32) replaced amino acids 921-1142 with 31 amino acids (ESSPQQASYQAKETAQRRGKAKTLLEMMCPR*). Three families were heterozygous for a previously reported single-nucleotide ENAM deletion (c.588+1delG/p.Asn197Ilefs*81). One of these families also harbored a heterozygous LAMA3 mutation (c.1559G>A/p.Cys520Tyr) that cosegregated with both the AI phenotype and the ENAM mutation. In mice, Ambn+/- maxillary incisors were normal. Ambn+/- molars were also normal, except for minor surface roughness. Ambn+/- mandibular incisors were sometimes chalky and showed minor chipping. Enam+/- incisor enamel was thinner than normal with ectopic mineral deposited laterally. Enam+/- molars were sometimes chalky and rough surfaced. Enam+/- Ambn+/- enamel was thin and rough, in part due to ectopic mineralization, but also underwent accelerated attrition. CONCLUSION: Novel ENAM mutations causing AI were identified, raising to 22 the number of ENAM variations known to cause AI. The severity of the enamel phenotype in Enam+/- Ambn+/- double heterozygous mice is caused by composite digenic effects. Digenic inheritance should be explored as a cause of AI in humans.

12.
J Anat ; 235(5): 912-930, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31402450

RESUMO

The 2D arrangement of rows of enamel rods with alternating (decussating) tilt angles across the thickness of the inner layer in rat and mouse incisor enamel is well known and assumed to occur in a uniform and repetitive pattern. Some irregularities in the arrangement of rows have been reported, but no detailed investigation of row structure across the entire inner enamel layer currently exists. This investigation was undertaken to determine if the global row pattern in mouse mandibular incisor enamel is predominately regular in nature with only occasional anomalies or if rows of enamel rods have more spatial complexity than previously suspected. The data from this investigation indicate that rows of enamel rods are highly variable in length and have complex transverse arrangements across the width and thickness of the inner enamel layer. The majority of rows are short or medium in length, with 87% having < 100 rods per row. The remaining 13% are long rows (with 100-233 rods per row) that contain 46% of all enamel rods seen in transverse sections. Variable numbers of rows were associated with the lateral, central and mesial regions of the enamel layer. Each region contained different ratios of short, medium and long rows. A variety of relationships was found along the transverse length of rows in each region, including uniform associations of alternating rod tilts between neighboring rows, and instances where two rows having the same rod tilt were paired for variable distances then moved apart to accommodate rows of opposite tilt. Sometimes a row appeared to branch into two rows with the same tilt, or conversely where two rows merged into one row depending upon the mesial-to-lateral direction in which the row was viewed. Some rows showed both pairing and branching/merging along their length. These tended to be among the longest rows identified, and they often crossed the central region with extensions into the lateral and mesial regions. The most frequent row arrangement was a row of petite length nestled at the side of another row having the same rod tilt (30% of all rows). These were termed 'focal stacks' and may relate to the evolution of uniserial rat and mouse incisor enamel from a multilayered ancestor. The mesial and lateral endpoints of rows also showed complex arrangements with the dentinoenamel junction (DEJ), the inner enamel layer itself, and the boundary area to the outer enamel layer. It was concluded that the diversity in row lengths and various spatial arrangements both within and between rows across the transverse plane provides a method to interlock the enamel layer across each region and keep the enamel layer compact relative to the curving DEJ surface. The uniserial pattern for rows in mouse mandibular incisors is not uniform, but diverse and very complex.

13.
Mol Genet Genomic Med ; 7(9): e929, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31402633

RESUMO

BACKGROUND: Ameloblastin (AMBN) is a secreted matrix protein that is critical for the formation of dental enamel and is enamel-specific with respect to its essential functions. Biallelic AMBN defects cause non-syndromic autosomal recessive amelogenesis imperfecta. Homozygous Ambn mutant mice expressing an internally truncated AMBN protein deposit only a soft mineral crust on the surface of dentin. METHODS: We characterized a family with hypoplastic amelogenesis imperfecta caused by AMBN compound heterozygous mutations (c.1061T>C; p.Leu354Pro/ c.1340C>T; p.Pro447Leu). We generated and characterized Ambn knockout/NLS-lacZ (AmbnlacZ/lacZ ) knockin mice. RESULTS: No AMBN protein was detected using immunohistochemistry in null mice. ß-galactosidase activity was specific for ameloblasts in incisors and molars, and islands of cells along developing molar roots. AmbnlacZ/lacZ 7-week incisors and unerupted (D14) first molars showed extreme enamel surface roughness. No abnormalities were observed in dentin mineralization or in nondental tissues. Ameloblasts in the AmbnlacZ/lacZ mice were unable to initiate appositional growth and started to degenerate and deposit ectopic mineral. No layer of initial enamel ribbons formed in the AmbnlacZ/lacZ mice, but pockets of amelogenin accumulated on the dentin surface along the ameloblast distal membrane and within the enamel organ epithelia (EOE). NLS-lacZ signal was positive in the epididymis and nasal epithelium, but negative in ovary, oviduct, uterus, prostate, seminal vesicles, testis, submandibular salivary gland, kidney, liver, bladder, and bone, even after 15 hr of incubation with X-gal. CONCLUSIONS: Ameloblastin is critical for the initiation of enamel ribbon formation, and its absence results in pathological mineralization within the enamel organ epithelia.

14.
Cell Res ; 29(9): 739-753, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31444469

RESUMO

Severe fever with thrombocytopenia syndrome (SFTS), an emerging tick-borne infectious disease caused by a novel phlebovirus (SFTS virus, SFTSV), was listed among the top 10 priority infectious diseases by the World Health Organization due to its high fatality of 12%-50% and possibility of pandemic transmission. Currently, effective anti-SFTSV intervention remains unavailable. Here, by screening a library of FDA-approved drugs, we found that benidipine hydrochloride, a calcium channel blocker (CCB), inhibited SFTSV replication in vitro. Benidipine hydrochloride was revealed to inhibit virus infection through impairing virus internalization and genome replication. Further experiments showed that a broad panel of CCBs, including nifedipine, inhibited SFTSV infection. The anti-SFTSV effect of these two CCBs was further analyzed in a humanized mouse model in which CCB treatment resulted in reduced viral load and decreased fatality rate. Importantly, by performing a retrospective clinical investigation on a large cohort of 2087 SFTS patients, we revealed that nifedipine administration enhanced virus clearance, improved clinical recovery, and remarkably reduced the case fatality rate by >5-fold. These findings are highly valuable for developing potential host-oriented therapeutics for SFTS and other lethal acute viral infections known to be inhibited by CCBs in vitro.

15.
Adv Mater ; 31(35): e1902618, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31293012

RESUMO

Optoelectronic devices based on metal halide perovskites, including solar cells and light-emitting diodes, have attracted tremendous research attention globally in the last decade. Due to their potential to achieve high carrier mobilities, organic-inorganic hybrid perovskite materials can enable high-performance, solution-processed field-effect transistors (FETs) for next-generation, low-cost, flexible electronic circuits and displays. However, the performance of perovskite FETs is hampered predominantly by device instabilities, whose origin remains poorly understood. Here, perovskite single-crystal FETs based on methylammonium lead bromide are studied and device instabilities due to electrochemical reactions at the interface between the perovskite and gold source-drain top contacts are investigated. Despite forming the contacts by a gentle, soft lamination method, evidence is found that even at such "ideal" interfaces, a defective, intermixed layer is formed at the interface upon biasing of the device. Using a bottom-contact, bottom-gate architecture, it is shown that it is possible to minimize such a reaction through a chemical modification of the electrodes, and this enables fabrication of perovskite single-crystal FETs with high mobility of up to ≈15 cm2 V-1 s-1 at 80 K. This work addresses one of the key challenges toward the realization of high-performance solution-processed perovskite FETs.

16.
Front Chem ; 7: 362, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31192190

RESUMO

Two novel aromatic imides, diarylcyclopentadienone-fused naphthalimides (BCPONI-2Br and TCPONI-2Br), are designed and synthesized by condensation coupling cyclopentadienone derivatives at the lateral position of naphthalimide skeleton. It has been found that BCPONI-2Br and TCPONI-2Br are highly electron-withdrawing acceptor moieties, which possess broad absorption bands and very low-lying LUMO energy levels, as low as -4.02 eV. On the basis of both building blocks, six low bandgap D-A copolymers (P1-P6) are prepared via Suzuki or Stille coupling reactions. The optical and electrochemical properties of the polymers are fine-tuned by the variations of donors (carbazole, benzodithiophene, and dithienopyrrole) and π-conjugation linkers (thiophene and benzene). All polymers exhibit several attractive photophysical and electrochemical properties, i.e., broad near-infrared (NIR) absorption, deep-lying LUMO levels (between -3.88 and -3.76 eV), and a very small optical bandgap ( E g opt ) as low as 0.81 eV, which represents the first aromatic diimide-based polymer with an E g opt of <1.0 eV. An investigation of charge carrier transport properties shows that P5 exhibits a moderately high hole mobility of 0.02 cm2 V-1 s-1 in bottom-gate field-effect transistors (FETs) and a typical ambipolar transport behavior in top-gate FETs. The findings suggest that BCPONI-2Br, TCPONI-2Br, and the other similar acceptor units are promising building blocks for novel organic semiconductors with outstanding NIR activity, high electron affinity, and low bandgap, which can be extended to various next-generation optoelectronic devices.

17.
Front Microbiol ; 10: 1096, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31178836

RESUMO

Exploring the characteristics of the HIV-1 envelope glycoprotein (env) gene in a natural HIV-1 infected individual, with broadly neutralizing activity, may provide insight into the generation of such broadly neutralizing antibodies and initiate the design of an appropriate immunogen. Recently, a chronically HIV-1 infected patient with broadly neutralization activity was identified and a VRC01-class neutralizing antibody DRVIA7 (A7) was isolated from the patient. In the present study, 155 full length HIV-1 env gene fragments (including 68 functionally Env clones) were amplified longitudinally from the plasma of six time points spanning over 5 years in this donor. Viral features were analyzed by comparing Env clones of different time points, as well as 165 Chinese HIV-1 subtype B env sequences from HIV Sequence Database (Chinese B_database). Shorter V1 length, less potential glycan and a lower ratio of NXT: NXS in gp160 were observed in the first five time points compared to that from the last time points, as well that from the Chinese B_database. A sequence analysis and a neutralization assay of Env-pseudoviruses showed that the increasing diversity of env sequences in the patient was consistent with the appearance and maturation of A7 lineage antibodies. The potent neutralization activity and viruses that escaped from the neutralization of the concurrent autologous plasma, are consistent with higher residue variations at the antibody recognition sites. Almost all viruses from the plasmas were neutralization-resistant to VRC01 and A7 lineage antibodies. For a chronically HIV-1 infected individual over 10 years, we found that greater viral diversity, short V1 sequences and less potential N-linked glycosylation (PNGS) in V1, might be associated with the development of broadly neutralizing antibody responses.

18.
Chem Commun (Camb) ; 55(54): 7812-7815, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31215565

RESUMO

Nitrogen analogues of Chichibabin's and Müller's hydrocarbons, DPh-D and TPh-D, based on 1,2,4-benzotriazinyl (Blatter) were studied. The two diradicaloids with good chemical and thermal stability exhibit smaller singlet-triplet energy gaps (ΔES-T from -1.05 to -1.27 kcal mol-1) than the hydrocarbon diradicaloids with the same bridges.

19.
Chemistry ; 25(39): 9266-9271, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31050042

RESUMO

A two-step, one-flask synthesis of central seven-membered borondifluoride-3,3-dimethyl-2-[2-(2-pyrrolyl)ethenyl] indole (BOPYIN) ligands has been developed by using the unexplored 3,3-dimethyl-2-[2-(2-pyrrolyl)ethenyl] indole. The simple synthetic approach has enabled modification of the electronic structure by changing the substituents on the indole unit. X-ray analysis indicated that conformations of the seven-membered BF2 complex including BOPYIN and diazaborepin differ from that of the five- and six-membered organoboron complexes. Interestingly, the bond angle of the N⋅⋅⋅B-N bond increases with the number of atoms in the core ring, based on Baeyer strain theory. These unsymmetric BOPYIN derivatives have excellent photophysical properties, including high fluorescence quantum yields, except for BOPYIN-4 in the solution state, large Stokes shifts, and good molar absorptivity. The dipole moment of BOPYIN-3 in the first excited singlet state and ground state was demonstrated by a linear Lippert-Mataga plot. The absorption and emission spectra were not mirror images for BOPYIN-1-3 and 5, in contradiction to Kasha's rule, as determined by TDDFT. The synthesized BOPYINs have been shown to be biocompatible fluorophores in cell bioimaging.


Assuntos
Indóis/química , Cristalografia por Raios X , Teoria da Densidade Funcional , Células HeLa , Humanos , Indóis/síntese química , Microscopia Confocal , Conformação Molecular , Espectrometria de Fluorescência
20.
Langmuir ; 35(21): 6939-6949, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31050292

RESUMO

Amphiphilic derivatives of fullerene C60 are attractive from viewpoints of supramolecular chemistry and biomedicine. The establishment of relationships among the molecular structure, aggregation behavior and properties such as scavenging radicals of the amphiphilic C60 derivatives is the key to push these carbon nanomaterials to real applications. In this work, six monosubstituted C60 derivatives were synthesized by a one-step quaternization of their neutral precursors, which bear Percec monodendrons terminated with oligo(poly(ethylene oxide)) (o-PEO) chain(s). The main difference among the C60 derivatives lies in the number and substituted position of the o-PEO chain(s) within the Percec monodendron. Derivative with a 4-substitution of the o-PEO chain still showed limited solubility in water. Other derivatives possessing two or three o-PEO chains exhibited much improved solubilities and rich aggregation behavior in water. It was found that the formation of aggregates is regulated both by the number and the substituted pattern of the o-PEO chains. Typical morphologies include nanosheets, nanowires, vesicles, nanotubes, and nanorods. Although the structures of the C60 derivatives are different from those of traditional surfactants, their aggregation behavior can be also well explained by applying the theory of critical packing parameter. Interestingly, the capabilities of the C60 derivatives to scavenge the hydroxyl radicals (OH·-) followed the same order of their solubility in water, where the compound bearing three o-PEO chains with a 2,3,4-substitution got the champion quenching efficiency of ∼97.79% at a concentration of 0.15 mg·mL-1 (∼0.11 mmol·L-1).

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