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1.
J Nanosci Nanotechnol ; 20(4): 2578-2583, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492279

RESUMO

Quaternary colloidal CuIn0.7Ga0.3S2 nanocrystals were synthesized by hot injection method using oleylamine as single solvent. The structure, morphology and optical absorption properties of assynthesized CuIn0.7Ga0.3S2 nanocrystals were characterized in detail using X-ray powder diffraction, transmission electron microscopy and UV-vis spectrometry. The as-fabricated CIGSSe thin film was obtained by spin-casting as-synthesized colloidal CuIn0.7Ga0.3S2 nanocrystals after selenization. The classical pn heterojunction CIGSSe/CdS thin film solar cells displayed the 6.18% power conversion efficiency under AM1.5G illumination.

2.
J Am Chem Soc ; 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31608623

RESUMO

The development of methodologies for inducing and tailoring enantioselectivities of catalysts is an important issue in asymmetric catalysis. In this work, we demonstrate for the first time that chiral molecular catalysts can be boosted from completely nonselective to highly enantioselective when installed in nanostructured metal-organic frameworks (MOFs). Exfoliation of layered crystals is one of the most direct synthetic routes to unltrathin nanosheets, but its use in MOFs is limited by the availability of layered MOFs. We illustrate that layered MOFs can be designed using ligand-capped metal clusters and angular organic linkers. This leads to the synthesis of two three-dimensional (3D) layered porous MOFs from Zn4-p-tert-butylsulfonyl calix[4]arene and chiral angular 1,1'-binaphthol/-biphenol dicarboxylic acids, which can be ultrasonic exfoliated into one- and two-layer nanosheets. The obtained MOF materials are efficient catalysts for asymmetric cascade condensation and cyclization of 2-aminobenzamide and aldehydes to produce 2,3-dihyroquinazolinones. While both binaphthol and biphenol display no enantioselectivity, restriction of their freedom in the MOFs leads to 56-90% and 46-72% ee, respectively, which are increased to 72-94% and 64-82% ee after exposure to external surfaces of the flexible nanosheets. Moreover, the MOF crystals and nanosheets exhibit highly sensitive fluorescent enhancement in the presence of chiral amino alcohols with enantioselectivity factors being, respectively, increased up to 1.4 and 2.3 times of the values of the diols, allowing them to be utilized in chiral sensing. Therefore, the observed enantioselectivities increase in the order organocatalyst < MOF crystals < MOF nanosheets in both catalysis and sensing. This work not only provides a strategy to make 3D layered MOFs and their untrathin nanosheets but also paves the way to utilize nanostructured MOFs to manipulate enantioselectivities of molecular catalysts.

3.
Proc Natl Acad Sci U S A ; 116(42): 21274-21284, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31575745

RESUMO

Plasmodesmata (PD) are plant-specific membrane-lined channels that create cytoplasmic and membrane continuities between adjacent cells, thereby facilitating cell-cell communication and virus movement. Plant cells have evolved diverse mechanisms to regulate PD plasticity in response to numerous environmental stimuli. In particular, during defense against plant pathogens, the defense hormone, salicylic acid (SA), plays a crucial role in the regulation of PD permeability in a callose-dependent manner. Here, we uncover a mechanism by which plants restrict the spreading of virus and PD cargoes using SA signaling by increasing lipid order and closure of PD. We showed that exogenous SA application triggered the compartmentalization of lipid raft nanodomains through a modulation of the lipid raft-regulatory protein, Remorin (REM). Genetic studies, superresolution imaging, and transmission electron microscopy observation together demonstrated that Arabidopsis REM1.2 and REM1.3 are crucial for plasma membrane nanodomain assembly to control PD aperture and functionality. In addition, we also found that a 14-3-3 epsilon protein modulates REM clustering and membrane nanodomain compartmentalization through its direct interaction with REM proteins. This study unveils a molecular mechanism by which the key plant defense hormone, SA, triggers membrane lipid nanodomain reorganization, thereby regulating PD closure to impede virus spreading.

5.
FEBS Lett ; 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31626714

RESUMO

The Voltage-gated sodium channels (VGSCs) are aberrantly expressed in a variety of tumors and play an important role in tumor growth and metastasis. Here, we show that VGSCs auxiliary ß3 subunit, encoded by the SCN3B gene, promotes proliferation and suppresses apoptosis in HepG2 cells by promoting p53 degradation. ß3 significantly increases HepG2 cell proliferation, promotes tumor growth in mouse xenograft models, and suppresses senescence and apoptosis. We found that ß3 knockdown stabilizes p53 protein, leading to potentiation of p53-induced cell cycle arrest, senescence and apoptosis. Mechanistic studies revealed that ß3 could bind to p53, promoting p53 ubiquitination and degradation by stabilizing the p53/MDM2 complex. Our results suggest that ß3 is a novel negative regulator of p53 and a potential oncogenic factor.

6.
Psychol Addict Behav ; 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31657594

RESUMO

It is unclear whether nicotine and perceived nicotine exposure can influence automatic evaluations of cigarette stimuli. In the present study, we investigated the effects of nicotine dose and instructed dose on motivational responses to smoking cues. Forty overnight nicotine-deprived smokers completed an Implicit Association Test (IAT) at each of the four laboratory sessions in a balanced-placebo design that crossed nicotine dose (Given-NIC [given nicotine] vs. Given-DENIC [given denicotinized]) with instructed dose expectancy (Told-NIC [told-nicotine] vs. Told-DENIC. [told-denicotinized]). We measured participants' behavioral performance, including reaction time (RT) and accuracy rate, and the early posterior negativity (EPN) component using the event-related potential (ERP) technique to the target pictures. During congruent trials when the categorization condition was smoking or unpleasant, smokers had greater classification accuracy, shorter RT latency, and greater EPN amplitudes compared to the incongruent trials when the categorization condition was smoking or pleasant. The Given-NIC condition was associated with increased classification accuracy, longer RT latency, and decreased EPN amplitudes compared to the Given-DENIC condition. Similarly, the Told-NIC condition was associated with increased accuracy and decreased EPN amplitudes compared to the Told-DENIC condition, but with shorter RT latency. Cigarette-related pictures produced greater EPN amplitudes than neutral pictures. Both behavioral and ERP results suggest that smokers have negative implicit attitudes toward smoking. While both nicotine dose and expected dose facilitated stimulus categorization, there was no evidence that either factor altered smokers' negative attitudes toward smoking cues. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

7.
Adv Mater ; 31(42): e1904512, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31490601

RESUMO

Organic photovoltaic (OPV) technologies have the advantages of fabricating larger-area and light-weight solar panels on flexible substrates by low-cost roll-to-toll production. Recently, OPV cells have achieved many significant advances with power conversion efficiency (PCE) increasing rapidly. However, large-scale solar farms using OPV modules still face great challenges, such as device stability. Herein, the applications of OPV cells in indoor light environments are studied. Via optimizing the active layers to have a good match with the indoor light source, 1 cm2 OPV cells are fabricated and a top PCE of 22% under 1000 lux light-emitting diode (2700 K) illumination is demonstrated. In this work, the light intensities are measured carefully. Incorporated with the external quantum efficiency and photon flux spectrum, the integral current densities of the cells are calculated to confirm the reliability of the photovoltaic measurement. In addition, the devices show much better stability under continuous indoor light illumination. The results suggest that designing wide-bandgap active materials to meet the requirements for the indoor OPV cells has a great potential in achieving higher photovoltaic performance.

8.
J Integr Plant Biol ; 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31483571

RESUMO

The endoplasmic reticulum (ER) is the major site for protein folding in eukaryotic cells. ER homeostasis is essential for the development of an organism, whereby the unfolded protein response (UPR) within the ER is precisely regulated. ER-phagy is a newly identified selective autophagic pathway for removal of misfolded or unfolded proteins within the ER in mammalian cells. Sec. 62, a component of the translocon complex, was recently characterized as an ER-phagy receptor during the ER stress recovery phase in mammals. In this study, we demonstrated that the Arabidopsis Sec. 62 (AtSec62) is required for plant development and might function as an ER-phagy receptor in plants. We showed that AtSec62 is an ER-localized membrane protein with three transmembrane domains (TMDs) with its C-terminus facing to the ER lumen. AtSec62 is required for plant development because AtSec62 mutants display impaired vegetative growth, abnormal pollen and decreased fertility. AtSec62 mutants are sensitive towards tunicamycin (TM)-induced ER stress, whereas overexpression of AtSec62 subsequently enhances stress tolerance during the ER stress recovery phase. Moreover, YFP-AtSec62 colocalizes with the autophagosome marker mCh-Atg8e in ring-like structures upon ER stress induction. Taken together, these data provide evidence for the pivotal roles of AtSec62 in plant development and ER-phagy. This article is protected by copyright. All rights reserved.

9.
Neuro Oncol ; 2019 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-31504810

RESUMO

BACKGROUND: Diffuse midline glioma (DMG), H3 K27M-mutant occurs in both adult and pediatric populations. The characteristics of the two DMG groups were systematically explored in this study. METHODS:  One-hundred-sixteen patients diagnosed with H3 K27M-mutant DMG in Beijing Tiantan Hospital from May 2016 to December 2018 were included. Patients were classified into adult group (n=57, 49.1%) and pediatric group (n=59, 50.9%). The clinical, radiological and molecular features were compared between the groups. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Compared with the adult group, pediatric patients had a younger age (8.9±4.1 vs. 35.1±11.8 years, P<0.001), a lower preoperative Karnofsky performance scale score (62.9±15.5 vs. 72.1±16.5, P=0.004), a lower rate of total resection (5.7% vs. 26.8%, P=0.009), a larger tumor size (4.4±0.9 vs. 3.9±1.5 cm, P=0.045), a higher Ki-67 index (63.0% vs. 37.8%, P=0.047), and higher rates of postoperative cranial nerve palsy (61.0% vs. 36.8%, P=0.009) and ataxia (45.8% vs. 26.3%, P=0.029). Adult DMG was predominantly located in the thalamus, while the predilection site for pediatric DMG was brainstem (P<0.001). Kaplan-Meier plot showed that the median survival of adult and pediatric DMG was 16.0 (9.7-22.3) months and 10.0 (8.3-11.7) months, respectively, which imparted a significant difference (P=0.008). Age at diagnosis, radiotherapy, motor deficit and hydrocephalus were confirmed as independent prognostic factors according to the multivariate analysis (P<0.05). CONCLUSION: Compared with adult patients, children with H3 K27M-mutant DMG confer distinct clinical, radiological and molecular characteristics, and have a dismal prognosis. Radiotherapy is an independent factor associated with prolonged survival.

10.
Adv Mater ; 31(39): e1903441, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31392768

RESUMO

Recent advances in nonfullerene acceptors (NFAs) have enabled the rapid increase in power conversion efficiencies (PCEs) of organic photovoltaic (OPV) cells. However, this progress is achieved using highly toxic solvents, which are not suitable for the scalable large-area processing method, becoming one of the biggest factors hindering the mass production and commercial applications of OPVs. Therefore, it is of great importance to get good eco-compatible processability when designing efficient OPV materials. Here, to achieve high efficiency and good processability of the NFAs in eco-compatible solvents, the flexible alkyl chains of the highly efficient NFA BTP-4F-8 (also known as Y6) are modified and BTP-4F-12 is synthesized. Combining with the polymer donor PBDB-TF, BTP-4F-12 shows the best PCE of 16.4%. Importantly, when the polymer donor PBDB-TF is replaced by T1 with better solubility, various eco-compatible solvents can be applied to fabricate OPV cells. Finally, over 14% efficiency is obtained with tetrahydrofuran (THF) as the processing solvent for 1.07 cm2 OPV cells by the blade-coating method. These results indicate that the simple modification of the side chain can be used to tune the processability of active layer materials and thus make it more applicable for the mass production with environmentally benign solvents.

11.
Sci Rep ; 9(1): 12582, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31467384

RESUMO

Pulmonary tuberculosis (PTB) is a common worldwide infection with high mortality and morbidity, especially in developing countries. This study analyzed PET/CT findings in tumor patients with radiographic lesions suggesting old healed pulmonary tuberculosis (OHPTB) and imaging follow-up to find and verify PET/CT signs that may predict tuberculosis recurrence. A retrospective analysis of the tumor patients was carried out. These patients underwent 18F-FDG PET/CT in our center from 2010 to 2018. Confirmation of tuberculosis recurrence was obtained by follow-up of morphological changes in old lesions by PET/CT or CT. In total, 238 patients with a complete medical history were included in the final study, and 22 patients experienced OHPTB recurrence. We found that the SUVmax of tuberculosis in PET/CT was significantly increased in the recurrence group compared to the non-recurrence group [5.00 (3.40, 7.30) vs. 1.10 (0.80, 1.30), P < 0.001]. The ROC curve showed good discrimination, with an AUC of 0.980, and a cut-off SUVmax value of 2.15 was identified (the sensitivity was 90.5%, the specificity was 97.2%, the positive predictive value was 76.0%, and the negative predictive value was 99.1%). Both the tumor and the anti-tumor treatment can cause the patient to be immunocompromised and might further cause the recurrence of OHPTB. Positive imaging on 18F-FDG PET can predict the recurrence of OHPPT. Although there might be a false positive, 18F-FDG PET can greatly narrow the monitoring range. A negative result on imaging has high reliability for eliminating the possibility of tuberculosis recurrence. PET/CT has important clinical significance in tuberculosis management in patients with concurrent OHPTB.

12.
Angew Chem Int Ed Engl ; 58(41): 14748-14757, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31389142

RESUMO

Chiral phosphoric acids are incorporated into indium-based metal-organic frameworks (In-MOFs) by sterically preventing them from coordination. This concept leads to the synthesis of three chiral porous 3D In-MOFs with different network topologies constructed from three enantiopure 1,1'-biphenol-phosphoric acid derived tetracarboxylate linkers. More importantly, all the uncoordinated phosphoric acid groups are periodically aligned within the channels and display significantly enhanced acidity compared to the non-immobilized acids. This facilitates the Brønsted acid catalysis of asymmetric condensation/amine addition and imine reduction. The enantioselectivities can be tuned (up to >99 % ee) by varying the substituents to achieve a nearly linear correlation with the concentrations of steric bulky groups in the MOFs. DFT calculations suggest that the framework provides a chiral confined microenvironment that dictates both selectivity and reactivity of chiral MOFs.

13.
Chin Med J (Engl) ; 132(17): 2096-2104, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31433330

RESUMO

OBJECTIVE: Dermoscopy is a useful technique for improving the diagnostic accuracy of various types of skin disorders. In China, dermoscopy has been widely accepted, and domestic researchers have made tremendous progress in the field of dermoscopy. The main purpose of this review is to summarize the current status of dermoscopy in China and identify its future directions. DATA SOURCES: Articles included in this review were obtained by searching the following databases: Wanfang, China National Knowledge Infrastructure, PubMed, and the Web of Science. We focused on research published before 2019 with keywords including dermoscopy, dermoscopic, dermoscope and trichoscopy. STUDY SELECTION: A total of 50 studies were selected. Of these studies, 20 studies were in Chinese and 30 in English, research samples of all the studies were collected from Chinese populations. RESULTS: Since 2000, more than 380 articles about dermoscopy have been published in domestic or foreign journals. Dermoscopy can improve the diagnostic accuracy of neoplastic diseases, evaluating the therapeutic effect of treatment, and determining the treatment endpoint, and it can also assist in the differential diagnosis of inflammatory diseases and in the assessment of the severity of the disease. In addition, researches about the applications of dermoscopy during surgical treatment have been published. Training courses aiming to improve the diagnostic ability of dermatologists, either face-to-face or online, have been offered. The Chinese Skin Image Database, launched in 2017 as a work platform for dermatologists, has promoted the development of dermoscopy in China. Computer-aided diagnostic systems based on the Chinese population are ready for use. In the future, cooperation, resource sharing, talent development, image management, and computer-aided diagnosis will be important directions for the development of dermoscopy in China. CONCLUSION: Dermoscopy has been widely used and developed in China, however, it still needs to address more challenges in the future.

14.
Opt Lett ; 44(17): 4359-4362, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31465402

RESUMO

The nonlinear frequency conversion of low-temporal-coherent light holds a variety of applications and has attracted considerable interest. However, its physical mechanism remains relatively unexplored, and the conversion efficiency and bandwidth are extremely insufficient. Here, considering the instantaneous broadband characteristics, we establish a model of second-harmonic generation (SHG) of a low-temporal-coherent pulse and reveal its differences from the coherent conditions. It is found that the second-harmonic spectrum distribution is proportional to the self-convolution of that of a fundamental wave. Because of this, we propose a method for realizing low-temporal-coherent SHG with high efficiency and broad bandwidth, and experimentally demonstrate a conversion efficiency up to 70% with a bandwidth of 3.1 THz (2.9 nm centered at 528 nm). To the best of our knowledge, this is the highest efficiency and broadest bandwidth of low-temporal-coherent SHG to date. Our research opens the door for the study of low-coherent nonlinear optical processes.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31436498

RESUMO

Purpose: This study analyzes the effect, long-term survival rate, and complications about preserving the left colonic artery (LCAP) in rectal cancer surgery. Methods: Relevant articles were systematically retrieved from multiple electronic databases, for example, EMBASE, BioMed Central, PubMed, Web of Science, and Cochrane. The time for retrieving was from the establishment of the database to December 31, 2018. Evaluated endpoints were effect of LCAP on the curative effect of rectal neoplasms, such as operation time, the amount of bleeding during the operation, root lymph nodes positive number, and the related complications (anastomotic leakage, etc.), postoperative urinary retention, 5-year survival rate, and recurrence differences in rates. Results: Totally 12 studies were included in this review. The meta-analysis showed that LCAP has less operation time and lower anastomotic leakage incidence. Intraoperative bleeding, root lymph nodes, and other complications did not show any significant difference. Conclusions: LCAP in radical rectal cancer surgery ensures both the radical resection of the tumor and the safety of the operation. So it can provide a new approach to the management of blood vessels and lymph nodes.

18.
Protoplasma ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31468195

RESUMO

Exocytosis is a key mechanism for delivering materials into the extracellular space for cell function and communication. In plant cells, conventional protein secretion (CPS) is achieved via an ER (endoplasmic reticulum)-Golgi-TGN (trans-Golgi network)-PM (plasma membrane) pathway. Unconventional protein secretion (UPS) bypassing these secretory organelles is also in operation and can potentially lead to the formation of extracellular vesicles (EVs) in plant cells. Although multiple types of EVs have been identified and shown to play important roles in mediating intercellular communications in mammalian cells, there has been a long debate about the possible existence of EVs in plants because of the presence of the cell wall. However, increasing evidence suggests that plants also release EVs having various functions including unconventional protein secretion, RNA transport, and defense against pathogens. In this review, we present an update on the current knowledge about the nature, secretory mechanism, and function of various types of EVs in plants. The key regulators involved in EV secretion are also summarized and discussed. We pay special attention to the function of EVs in plant defense and symbiosis.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31292933

RESUMO

There is an increasing concern on the drug loading capacity of microneedles (MNs) to meet higher drug dosage requirement. The present study describes the fabrication of modified rapidly separating polyvinyl alcohol (PVA)-based MNs (RS-P-MNs) with high drug loading using a mechanical agitation process. The drugs encapsulated within the PVA polymer gel by mechanical agitation served as an encapsulating agent for drugs that provide a high drug loading capacity and also release of drugs in a controlled manner. The various parameters such as microscopic analysis, atomic force microscopy (AFM), drug loading, drug delivery efficiency, mechanical test, skin penetration ability, and in vitro and in vivo analyses indicate the great potential of the RS-P-MNs. The maximum drug loading capacity of RS-P-MNs was measured to be approximately 900 ng per microneedle, which was almost a hundred times than the traditional drug encapsulating mode. The in vitro and in vivo results suggested that the controlled release of drugs is due to the encapsulating mode (mechanical agitation) of drugs. The prepared RS-P-MNs with high drug loading in this study provided a gentle and controlled release of drugs instead of the robust release of drugs from traditional MNs. Graphical abstract.

20.
Adv Mater ; 31(36): e1902302, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31294900

RESUMO

Recent advances in the material design and synthesis of nonfullerene acceptors (NFAs) have revealed a new landscape for polymer solar cells (PSCs) and have boosted the power conversion efficiencies (PCEs) to over 15%. Further improvements of the photovoltaic performance are a significant challenge in NFA-PSCs based on binary donor:acceptor blends. In this study, ternary PSCs are fabricated by incorporating a fullerene derivative, PC61 BM, into a combination of a polymer donor (PBDB-TF) and a fused-ring NFA (Y6) and a very high PCE of 16.5% (certified as 16.2%) is recorded. Detailed studies suggest that the loading of PC61 BM into the PBDB-TF:Y6 blend can not only enhance the electron mobility but also can increase the electroluminescence quantum efficiency, leading to balanced charge transport and reduced nonradiative energy losses simultaneously. This work suggests that utilizing the complementary advantages of fullerene and NFAs is a promising way to finely tune the detailed photovoltaic parameters and further improve the PCEs of PSCs.

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