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1.
Artigo em Inglês | MEDLINE | ID: mdl-38350229

RESUMO

Near-infrared organic photodetectors possess great application potential in night vision, optical communication, and image sensing, but their development is limited by the lack of narrow bandgap organic semiconductors. A-D-A'-D-A-type molecules, featuring multiple intramolecular charge transfer effects, offer a robust framework for achieving near-infrared light absorption. Herein, we report a novel A-D-A'-D-A-type narrow bandgap electron acceptor named DPPSe-4Cl, which incorporates a selenophene-flanked diketopyrrolopyrrole (Se-DPP) unit as its central A' component. This molecule demonstrates exceptional near-infrared absorption properties with an absorption onset reaching 1120 nm and a low optical bandgap of 1.11 eV, owing to the strong electron-withdrawing ability and quinoidal resonance effect induced by the Se-DPP unit. By implementing a doping compensation strategy assisted by Y6 to reduce the trap density in the photoactive layer, the optimized organic photodetector based on DPPSe-4Cl exhibited efficient spectral response and remarkable sensitivity in the range of 300-1100 nm. Particularly, a specific detectivity surpassing 1012 Jones in the wavelength range of 410-1030 nm is achieved. This work offers a promising approach for developing highly sensitive visible to near-infrared broadband photodetection technology using organic semiconductors.

2.
Adv Mater ; 36(19): e2310811, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38358297

RESUMO

Detecting short-wavelength infrared (SWIR) light has underpinned several emerging technologies. However, the development of highly sensitive organic photodetectors (OPDs) operating in the SWIR region is hindered by their poor external quantum efficiencies (EQEs) and high dark currents. Herein, the development of high-sensitivity SWIR-OPDs with an efficient photoelectric response extending up to 1.3 µm is reported. These OPDs utilize a new ultralow-bandgap molecular semiconductor featuring a quinoidal tricyclic electron-deficient central unit and multiple non-covalent conformation locks. The SWIR-OPD achieves an unprecedented EQE of 26% under zero bias and an even more impressive EQE of up to 41% under a -4 V bias at 1.10 µm, effectively pushing the detection limit of silicon photodetectors. Additionally, the low energetic disorder and trap density in the active layer lead to significant suppression of thermal-generation carriers and dark current, resulting in excellent detectivity (Dsh *) exceeding 1013 Jones from 0.50 to 1.21 µm and surpassing 1012 Jones even at 1.30 µm under zero bias, marking the highest achievements for OPDs beyond the silicon limit to date. Validation with photoplethysmography measurements, a spectrometer prototype in the 0.35-1.25 µm range, and image capture under 1.20 µm irradiation demonstrate the extensive applications of this SWIR-OPD.

3.
J Hazard Mater ; 465: 133449, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38218036

RESUMO

Nuclear power emerges as a beacon of hope in tackling the energy crisis. However, the emission of radioactive iodine originating from nuclear waste and accidents poses a serious danger to nature and human well-being. Therefore, it becomes imperative to urgently develop suitable adsorbents capable of iodine capture and long-term storage. It's generally recognized that achieving high iodine capture efficiency necessitates the presence of electron-rich pores/cavities that facilitate charge-transfer (CT) interactions, as well as effective sorption sites capable of engaging in lone pair interactions with iodine. In this study, an unprecedented iodine capture paradigm by nonporous amorphous electron-deficient tetracationic cycloalkanes in vapor and aqueous solutions is revealed, overturning preconceived notions of iodine trapping materials. A newly reported tetracationic cyclophane, BPy-Box4+, exhibited an exceptional iodine vapor sorption capacity of 3.99 g g-1, remarkable iodine removal efficiency in aqueous media, and outstanding reusability. The iodine capture mechanism is unambiguously elucidated by theoretical calculations and the single-crystal structures of cyclophanes with a gradual increase in iodine content, underlining the vital role of host-guest (1:1 or 1:2) interactions for the enhanced iodine capture. The current study demonstrates a new paradigm for enhanced iodine capture by nonporous amorphous electron-deficient cyclophanes through host-guest complexation.

5.
Front Pharmacol ; 13: 955421, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36210803

RESUMO

The goal of the study was to analyze whether WJP can alleviate visceral hypersensitivity in IBS-D model rats. In this study, 36 Sprague-Dawley (SD) rats aged 4 weeks old were randomly divided into two groups: the model group (n = 27) and the control group (n = 9). The rat model of IBS-D was established by modified compound methods for 4 weeks. After the modification, IBS-D rats were randomly divided into three groups, namely, the IBS-D model group (n = 9), the positive drug group (n = 9), and the WJP group (n = 9), with different interventions, respectively. The control group was fed and allowed to drink water routinely. The Bristol stool scale scores were used to assess the severity of diarrhea. Abdominal withdrawal reflex (AWR) scores were used to assess visceral sensitivity. Expression of TNF-α was measured, and histopathological examinations were performed to assess colon inflammation in IBS-D model rats. Key factors of the MEK/ERK signal pathway in the tissue of the colon and hippocampus were measured to analyze the mechanism of WJP. Compared with the control group, the Bristol stool scale scores in the model group were significantly increased (p < 0.0001). The scores of the WJP group were significantly decreased compared with the model group (p = 0.0001). Compared with the control group, AWR scores in the model group at each pressure level were significantly increased (p = 0.0003, p < 0.0001, p = 0.0007, and p = 0.0009). AWR scores of the WJP group were significantly decreased compared with the model group (p = 0.0003, p = 0.0007, p = 0.0007, and p = 0.0009). Compared with the control group, the model group had significantly higher expression of TNF-α in the colon tissue (p < 0.0001). However, the WJP group had significantly lower level of TNF-α compared with the model group (p < 0.0001). Meanwhile, compared with the control group, the relative expression of the proteins of p-MEK1/2, p-ERK1, and p-ERK2 in the colon tissue was significantly increased in the model group (p < 0.0001). Compared with the model group, the relative expression of the proteins in the colon tissue were significantly decreased in the WJP group (p < 0.0001, p = 0.0019, and p = 0.0013). Compared with the control group, the relative expression of the proteins of p-MEK1/2, p-ERK1, and p-ERK2 in the hippocampus tissue were significantly increased in the model group (p < 0.0001). Compared with the model group, the relative expression of the proteins in the hippocampus tissue were significantly decreased in the WJP group (p = 0.0126, p = 0.0291, and p = 0.0145). The results indicated that WJP can alleviate visceral hypersensitivity in IBS-D model rats, possibly mediated by downregulating the expression of TNF-α, p-MEK1/2, p-ERK1, and p-ERK2 in the colon tissue. At the same time, WJP also affects downregulating the expression of p-MEK1/2, p-ERK1, and p-ERK2 in the hippocampus tissue.

6.
Medicine (Baltimore) ; 99(45): e23014, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33157947

RESUMO

BACKGROUND: Functional dyspepsia (FD) is a common functional gastrointestinal disease. Acupuncture, including electroacupuncture (EA) is widely used as a complementary and alternative treatment for patients with FD. This study aimed to explore the effectiveness of EA for the treatment of FD. METHODS: We searched Embase, PubMed, and the Cochrane Central Register of Controlled Trials (Cochrane Library) for randomized controlled trials of FD treated by EA from inception to February 3, 2020. Two reviewers will independently screen studies for data extraction and assess the quality and risk of bias. The Cochrane Collaboration's risk of bias tool, RevMan 5.3 software were used for meta-analysis. Data were pooled to calculate relative risk and 95% confidence intervals (CIs) of substantial improvement after treatment for dichotomous data and mean differences (SMDs) and 95% CIs for continuous data. RESULTS: Seven randomized clinical trials included 853 patients. This meta-analysis investigated the effectiveness of EA alone in the treatment of FD relative to sham-EA or pharmacologic medication (PM). The results showed that EA could significantly improve clinical symptoms. Compared with sham-EA, EA was more effective in reducing symptom scores (SMD -3.44, 95% CI -4.21 to -2.67) and increasing normal slow waves of electrogastrogram (SMD 0.93, 95% CI -0.30 to1.55). When EA was combined with PM, there was no significant difference in reducing symptom scores (SMD -0.18, 95% CI -0.51 to 0.16), increasing the effective rate of clinical symptoms (risk ratio 1.04, 95% CI 0.96 to 1.13), enhancing the level of plasma motilin (SMD 0.93, 95% CI -0.30 to1.55), and reducing gastric half-emptying time (SMD 0.02, 95% CI -0.16 to 0.20). The results also showed that there were very few adverse events reported. CONCLUSION: This meta-analysis suggests that EA is better than the placebo (sham-EA) in treating FD, and the therapeutic effect of EA on FD is equivalent to that of PM on FD. Compared with PM, EA for FD is safer and has fewer adverse reactions. Despite limitations due to the quality and number of the included studies, EA might be used as an effective and safe treatment for FD.


Assuntos
Dispepsia/fisiopatologia , Dispepsia/terapia , Eletroacupuntura/métodos , Terapia por Acupuntura/métodos , Estudos de Casos e Controles , Eletroacupuntura/efeitos adversos , Humanos , Motilina/sangue , Placebos/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
7.
ACS Appl Mater Interfaces ; 12(1): 753-762, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31808333

RESUMO

Large energy loss is one of the key factors that limit the power conversion efficiency (PCE) of organic solar cells (OSCs). In this work, we report reduced energy losses of OSCs via introducing thiazole π-spacers with different orientations to replace the thiophene π-spacers of the prototype polymer PBDB-T. The newly formed thiazole-containing isomeric polymers, PBDBTz-2 and PBDBTz-5, exhibited blue-shifted absorption and deeper lying energy levels compared to PBDB-T. When blended with IT-4F, the two polymers realized PCEs of 10.4% for PBDBTz-2 and 9.6% for PBDBTz-5, respectively, which were higher than that of PBDB-T (PCE = 9.3%). More critically, considerable open-circuit voltage (Voc) enhancements were achieved by PBDBTz-2 and PBDBTz-5, which were 0.14 and 0.21 V higher than that of PBDB-T. A detailed analysis showed that the reduced energy loss resulted from the lower radiative recombination below the band gap and nonradiative recombination loss. This study demonstrated that the introduction of thiazole π-spacers with different orientations is effective to reduce the energy losses of OSCs, which provided valuable inspirations for the development of new conjugated polymers to the efficiency breakthrough of OSCs in future.

8.
Am J Primatol ; 16(3): 275-284, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-31968860

RESUMO

Winter ranging patterns of Rhinopithecus bieti were determined using feces as the ranging trace. The appearance of the feces was unique in the study habitat. The sampled habitats were a well-forested area and a partly altered one. Analyses of excrement distribution showed: (1) monkeys tended to use the upper part of the forest belt, ranging between 3,900 and 4,100 m above sea level; (2) monkeys came to the ground and used the partly altered habitat, where only some forest remained; (3) the structure of resources had little influence on determining the ranging elevation; and (4) the animals spent more time in the local valley than on the local ridge, probably using the former as a sleeping site.

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