Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.631
Filtrar
1.
IEEE Trans Image Process ; 29: 1-14, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31265394

RESUMO

The prevailing characteristics of micro-videos result in the less descriptive power of each modality. The micro-video representations, several pioneer efforts proposed, are limited in implicitly exploring the consistency between different modality information but ignore the complementarity. In this paper, we focus on how to explicitly separate the consistent features and the complementary features from the mixed information and harness their combination to improve the expressiveness of each modality. Toward this end, we present a neural multimodal cooperative learning (NMCL) model to split the consistent component and the complementary component by a novel relation-aware attention mechanism. Specifically, the computed attention score can be used to measure the correlation between the features extracted from different modalities. Then, a threshold is learned for each modality to distinguish the consistent and complementary features according to the score. Thereafter, we integrate the consistent parts to enhance the representations and supplement the complementary ones to reinforce the information in each modality. As to the problem of redundant information, which may cause overfitting and is hard to distinguish, we devise an attention network to dynamically capture the features which closely related the category and output a discriminative representation for prediction. The experimental results on a real-world micro-video dataset show that the NMCL outperforms the state-of-the-art methods. Further studies verify the effectiveness and cooperative effects brought by the attentive mechanism.

2.
J Hazard Mater ; 382: 121002, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31450208

RESUMO

Modified biochar has great potential for adsorbing cadmium (Cd) in the aquatic environment, but the micro-immobilization mechanisms, driven by surface modifications, remain unclear. There has been no attempt to determine the key adsorption factors by integrating the numerous physiochemical indicators. In this study, surface oxidized biochar (OPBC) and surface aminated biochar (APBC) were prepared from porous biochar (PBC), and the Cd adsorption mechanisms by the modified biochars at the molecular and electronic scales were investigated. The adsorption capacity of APBC and OPBC for Cd was 23.54 and 19.04 mg g-1, respectively, which was about three times higher than that of PBC. Macroscopically, physicochemical adsorption and intraparticle diffusion dominated the Cd adsorption, and surface properties, such as functional groups, were identified as key factors controlling adsorption. Microscopically, the adsorption of Cd mainly occurred in regions rich in π electrons, lone pair electrons and electron donor groups. The interaction between carboxyl and Cd dominated the adsorption performance of OPBC, while the Cd2+-π interaction was weakened by increasing the π electron electrostatic potential of aromatic rings. The lone pair electrons of the amino groups dominated the complexation of APBC with Cd, and the π electron electrostatic potential was almost unaffected.

3.
J Nanosci Nanotechnol ; 20(4): 2087-2094, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492216

RESUMO

The wound of diabetic foot is difficult to heal, and in severe cases, diabetic patients have to undergo limb amputation even after wound management. Hyperglycemia-caused vascular dysfunction and serious wound bacterial infection are the two main causes of unhealed diabetic foot ulcers. Therefore, it would be of great benefit to rescue stalled healing in diabetic wound if the blood glucose concentration can be efficiently decreased while controlling the bacterial infection in diabetic wound. Herein, we report glucose oxidase (GOx)-loaded antimicrobial peptide hydrogels and investigate their potential as diabetic wound dressings. The antimicrobial hydrogels are formed by the selfassembly of a heptapeptide (IKYLSVN) driven by intermolecular hydrogen bonding and π-π stacking interaction. The loaded GOx can convert glucose into hydrogen peroxide (H2O2), thus reducing blood glucose concentration of diabetic patients. At the same time, the produced H2O2 is antimicrobial and can combat bacterial infection in diabetic wound together with the antimicrobial hydrogels. Microscopic morphology observation of hydrogel shows uniform fibers with approximately 40 nm in size. The embedding rate can still reach 90% when the loading rate of the hydrogel loaded glucose oxidase is 12%. GOx is released by the swelling of the hydrogel based on the mechanism of free diffusion, and the cumulative release rate reaches 55%. Moreover, in vitro experiments showed that our GOx-loaded peptide hydrogel exhibits outstanding antimicrobial activity while can efficiently reduce glucose concentration of blood samples, showing great potential as promising diabetic wound dressings.

4.
Int J Food Microbiol ; 312: 108358, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31655356

RESUMO

Meat products are commonly regarded as one of the main sources of human listeriosis caused by Listeria monocytogenes. The objective of this study was to estimate the prevalence of L. monocytogenes in a range of meat products from 24 different Chinese regions by using meta-analysis of literature data and a novel sensitivity analysis approach. A total of 112 publications from five databases, published between 1 January 2007 and 31 December 2017, were systematically selected for relevance and covered meat products sampled between 2000 and 2016. Estimated by the random-effects model, the pooled prevalence of L. monocytogenes was 8.5% (95% CI: 7.1%-10.3%) in raw meats and 3.2% (95% CI: 2.7%-3.9%) in ready-to-eat (RTE) meats. The prevalence differed from high to low among raw meats including prefabricated raw meats 12.6% (95% CI: 6.9%-21.7%), fresh pork 11.4% (95% CI: 8.6%-14.9%), fresh beef 9.1% (95% CI: 6.3%-13.0%), fresh poultry 7.2% (95% CI:4.9%-10.4%), frozen raw meats 7.2% (95% CI: 5.7%-9.0%), and fresh mutton 5.4% (95% CI: 2.5%-11.0%). A higher L. monocytogenes prevalence level was shown in the meat products from central and northeastern China provincial regions. The entropy-based sensitivity analysis utilized in the meta-analysis indicated that the sampling period and location were two critical factors influencing the prevalence level of L. monocytogenes in meat products. A better understanding of differences in prevalence levels per geographic region and between meat product sources may allow the competent authorities, industry, and other relevant stakeholders to tailor their interventions to control the occurrence of L. monocytogenes in meat products effectively.

5.
Opt Express ; 27(21): 29817-29828, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684238

RESUMO

Optical discrete multi-tone (DMT) is one type of direct-detection optical orthogonal frequency-division multiplexing (DDO-OFDM), and it is more suitable for cost-sensitive access networks and optical interconnections due to its simple structure. In DMT transmitter, inverse fast Fourier transform (IFFT) is an essential function for achieving OFDM modulation, and its input data are constrained to have Hermitian symmetry (HS). To support high-speed DMT signal generation, a fully-parallel implementation of IFFT is preferable. However, the hardware implementation of the conventional complex-valued IFFT (CC-IFFT) requires large area and has high power consumption. Based on the nature of HS, we design and implement a fully-parallel pipelined 128-point radix-2 decimation-in-time Hermitian-symmetric IFFT (HS-IFFT) by using a single field programmable gate array (FPGA) chip. On-chip resource utilization is analyzed for both the proposed HS-IFFT and CC-IFFT. It exhibits that the HS-IFFT can save up to 35% multipliers, 49% registers and 43% look-up tables (LUTs) compared to the CC-IFFT. Also, by using the HS-IFFT and CC-IFFT, two FPGA-based real-time baseband DMT transmitters are implemented and power consumption is estimated. More than 32% of on-chip power is saved by using the HS-IFFT. Moreover, the two DMT transmitters are also experimentally demonstrated in a short-reach directly-modulated laser (DML)-based optical DMT system. The experimental results show that the HS-IFFT-DMT has the same bit error rate (BER) and error vector magnitude (EVM) performances as the CC-IFFT-DMT in both electrical/optical back-to-back cases (EB2B/OB2B) and post 20-km single-mode fiber (SMF) transmission.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31685423

RESUMO

In this work, 3-Phenyl-N-[4-(10,15,20-triphenyl-porphyrin-5-yl)-phenyl]- acrylamide (TPPCA) was synthesized for the determination of metronidazole (MTZ). It was found that the type of fluorescence quenching was static quenching determined by Stern-Volmer plot and UV absorption spectroscopy, and thermodynamic related parameters were also obtained. Furthermore, the corresponding measurement conditions: the acidity of the system, the type of surfactant, the concentration of TPPCA and the sequence of reagent addition were optimized. Under the optimal experimental conditions, the linear range of MTZ was determined to be 0.01-0.20 µg mL-1, and the limit of detection (LOD) was 0.004 µg mL-1. Importantly, this report provides a simple, fast, and sensitive probe for the determination of MTZ in pharmaceutical practice.

7.
J Sep Sci ; 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31675760

RESUMO

Off-line comprehensive two-dimensional reversed-phase countercurrent chromatography with high-performance liquid chromatography was investigated in separation of crude ethanol extract from traditional Chinese medicinal herb Polygonum cuspidatum Sieb. et Zucc. Two-dimensional contour plots for countercurrent chromatography with high-performance liquid chromatography was obtained after comprehensive separation was completed. Total peak capacity was evaluated and approximately 810 peaks were obtained through a comprehensive two-dimensional separation. A highly orthogonality of 52.23% and a large separation space occupancy of 88.86% were achieved. Meanwhile, it was found that several components could be well separated by countercurrent chromatography while they could not be separated by high-performance liquid chromatography, and vice versa, which further indicated the orthogonality of the two separation methods. The off-line comprehensive two-dimensional countercurrent chromatography with high-performance liquid chromatography provided a promising and powerful method for separation of complex natural products.

8.
Cancer Med ; 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31724329

RESUMO

Reproductive factors associated with breast cancer risk may also affect the prognosis. This study aimed to evaluate the associations of multiple reproductive factors with breast cancer prognosis and the modifying effects of menopausal status. We obtained data from 3805 breast cancer patients recruited between October 2008 and June 2016 in Guangzhou. The subjects were followed up until 30 June 2018. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using multivariate Cox models to estimate the associations. It was found that there were U-shaped patterns for the associations of age at first birth and durations from first/last birth to diagnosis with breast cancer prognosis. The adverse effects of old age at first birth [>30 years vs 23-30 years, HR (95% CI): 1.59 (1.01-2.50)] and long intervals from first [≥20 years vs 10-19 years, HR (95% CI): 1.55 (1.07-2.27)] or last [≥20 years vs 10-19 years, HR (95% CI): 1.63 (1.08-2.46)] birth to diagnosis on progression-free survival (PFS) were significantly more pronounced among premenopausal women. Additionally, long interval (>5 years) between first and second birth was associated with a better PFS [HR (95% CI): 0.64 (0.42-0.97)]. These results suggested that age at first birth, durations from first/last birth to diagnosis, and intervals between first and second birth should be taken into account when following the patients and assessing the prognosis of breast cancer, particularly for premenopausal patients. These findings would also have implications for further insight into the mechanisms of breast cancer development.

9.
Theranostics ; 9(25): 7759-7771, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695799

RESUMO

Cancer immunotherapy modulates and leverages the host immune system to treat cancer. The past decade has witnessed historical advancement of cancer immunotherapy. A myriad of approaches have been explored to elicit or augment anticancer innate immunity and/or adaptive immunity. Recently, activation of stimulator of interferon (IFN) genes (STING), an intracellular receptor residing in the endoplasmic reticulum, has shown great potential to enhance antitumor immunity through the induction of a variety of pro-inflammatory cytokines and chemokines, including type I IFNs. A number of natural and synthetic STING agonists have been discovered or developed, and tested in preclinical models and in the clinic for the immunotherapy of diseases such as cancer and infectious diseases. Cyclic dinucleotides (CDNs), such as cyclic dimeric guanosine monophosphate (c-di-GMP), cyclic dimeric adenosine monophosphate (c-di-AMP), and cyclic GMP-AMP (cGAMP), are a class of STING agonists that can elicit immune responses. However, natural CDNs are hydrophilic small molecules with negative charges and are susceptible to enzymatic degradation, leading to low bioavailability in target tissues yet unwanted toxicities and narrow therapeutic windows. Drug delivery systems, coupled with nucleic acid chemistry, have been exploited to address these challenges. Here, we will discuss the underlying immunological mechanisms and approaches to STING activation, with a focus on the delivery of STING agonists, for cancer immunotherapy.

10.
Biomed Chromatogr ; : e4724, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31755117

RESUMO

Lipid metabolism has a significant function in the central nervous system and Alzheimer's disease (AD) is an age-related senile disease characterized by central nerve degeneration. The pathological development of AD is closely related to lipid metabolism disorders. To reveal the influence of Kai-Xin-San (KXS) on lipid metabolism in APP/PSI transgenic mice and potential therapeutic targets for treating AD, the brain tissue samples were collected and analyzed by high-throughput lipidomics based on UPLC-Q/TOF-MS tool. The collected raw data were processed by multivariate data analysis method to discover the potential biomarkers and lipid metabolic profiles. Compared with the control wild-type mice group, 9 potential lipid biomarkers were found in the AD model group, of which 7 were up-regulated and 2 were down-regulated. Orally administrated KXS can reverse the change of these potential biomarkers. Compared with the model group, a total of 6 differential metabolites have recovery trend and may be potential targets for KXS to treat AD. In this study, it showed that high-throughput lipidomics can discover the perturbed pathways and lipid biomarkers as potential targets to reveal the therapeutic effects of KXS.

11.
ACS Nano ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31714057

RESUMO

Elevated intraocular pressure (IOP) is the most significant risk factor contributing to visual field loss in glaucoma. Unfortunately, the deficiencies associated with current therapies have resulted in reduced efficacy, several daily dosings, and poor patient compliance. Previously, we identified the calcium voltage-gated channel auxiliary subunit alpha2delta 1 gene (Cacna2d1) as a modulator of IOP and demonstrated that pregabalin, a drug with high affinity and selectivity for CACNA2D1, lowered IOP in a dose-dependent manner. Unfortunately, IOP returned to baseline at 6 h after dosing. In the current study, we develop a once daily topical pregabalin-loaded multiple water-in-oil-in-water microemulsion formulation to improve drug efficacy. We characterize our formulations using multiple in vitro and in vivo evaluations. Our lead formulation provides continuous release of pregabalin for up to 24 h. Because of its miniscule droplet size (<20 nm), our microemulsion has a transparent appearance and should not blur vision. It is also stable at one month of storage at temperatures ranging from 5 to 40 °C. Our formulation is nontoxic, as illustrated by a cell toxicity study and slit-lamp biomicroscopic exams. CACNA2D1 is highly expressed in both the ciliary body and the trabecular meshwork, where it functions to modulate IOP. A single drop of our lead pregabalin formulation reduces IOP by greater than 40%, which does not return to baseline until >30 h post-application. Although there were no significant differences in the amplitude of IOP reduction between the formulations we tested, a significant difference was clearly observed in their duration of action. Our multilayered microemulsion is a promising carrier that sustains the release and prolongs the duration of action of pregabalin, a proposed glaucoma therapeutic.

12.
Environ Monit Assess ; 191(12): 709, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31677005

RESUMO

With the increase of population, many cities are growing in size at a phenomenal rate. Urbanization changes the urban underlying surface, influences the micro-climate, and sometimes affects the local precipitation process. In this study, we investigated the trends of extreme rainfall in China's 21 typical urban areas. Based on a series of daily rainfall and "Urban/built-up" dataset from TMPA 3B42 and MCD12Q1 products in China, trends in extreme precipitation, with the threshold defined as 95th (pre95p) and 99th (pre99p) percentiles of annual rain days during 1998-2015, have been assessed in China, and especially in 21 typical urban areas from 1998 to 2015. The tendency curves in extreme rainfall of different years are presented. In this period, more than 66% regions of China covered by TMPA 3B42 have increasing trends in extreme rainfall with pre95p threshold. The 21 typical urban areas showed different trends-in over half of these areas, upward tendencies in extreme rainfall were observed, particularly in Dalian, Beijing, and Chongqing. Seventeen urban areas showed increasing tendencies in pre95p extreme rainfall days, including Shanghai, Nanjing, Hangzhou, and Suzhou in the Yangtze River Delta region. The results also illustrate that southeastern coastal urban areas of China may have experienced decreasing occurrences in extreme rainfall.

13.
Ecotoxicol Environ Saf ; : 109906, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31708226

RESUMO

Despite the toxicity of mercury for mammal has been widely studied in recent years, little is known on its impact on the soil microbiome. In this paper, the effects of mercury in soils microbial communities along a gradient of contamination from no to high concentration was assessed by the richness and diversity of microbial community using high throughput sequencing method. The richness of microbial community decreased gradually with the increase of culture time, while the low and medium concentration of mercury had little effect on the evenness of soil microbial community. Proteobacteria tolerated the mercury contamination, while Acidobacteria, Planctomycetes and Chloroflexi were sensitive to mercury pollution in phylum level. Omnitrophica and Ignavibacteriae microorganisms were very sensitive to mercury contamination and dead quickly when contaminated with mercury. Mercury contamination selected two mercury tolerance genuses which were Massilia and Burkholderia in genus level and at least 22 microorganisms such as Alkanindiges, Geothrix, Polycyclovorans and Sporichthya in genus which mainly from the Acidobacteria, Proteobacteria, Bacteroides, Chloroflexi and Omnitrophica phylum were sensitive to mercury. The bacteria tolerant to mercury in soil were Massilia and Burkholderia from Betaproteobacteria and Lysobacter, Luteimonas from Gammaproteobacteria, separately, they were Gram-negative bacteria with thin cell walls and complex ingredients that responded quickly to pollution stress.

14.
Bioresour Technol ; : 122351, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31708386

RESUMO

This study investigates the prospective of utilizing kitchen wastewater and food wastes, biofuels industry byproducts as alternative water and carbon sources. Kitchen wastewater did not impede cellular growth rate of the evolved Phaeodactylum strain E70, which indicates its potential as an alternative to freshwater resources. Among the organic wastes assessed, food waste hydrolysate significantly increased cell growth. Supplement of crude glycerol in cultivation medium enhances the total fatty acid content. Mixed food waste hydrolysate and crude glycerol remarkably increased both the cell density and total fatty acid content. Also, the supplement of butylated hydroxytoluene alleviated the oxidative stress induced by impurities in organic wastes and concomitantly increased microalgal total fatty acids and polyunsaturated fatty acids content. The experimental results reported in this study show that a waste-based biorefinery could lead to utilization of organic waste resources for the efficient production of value-added products.

15.
J Hazard Mater ; : 121593, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31744726

RESUMO

Hierarchical ZSM-5 zeolite with meso- and micro-pore structures was successfully prepared through a facile one-pot hydrothermal synthesis method using bifunctional template. After copper ion-exchange, it was applied for the selective catalytic reduction of NO with NH3 (NH3-SCR). Compared with conventional Cu-ZSM-5 catalyst containing only micropores, the hierarchical catalyst with ca. 2 wt.% Cu loading displayed significantly improved catalytic performance. Particularly, the hierarchical zeolite catalyst also displayed excellent hydrothermal stability and sulfur resistance that exhibited great potential in practical application. Characterization techniques such as XRD, N2 physisorption, temperature programmed desorption/reduction (TPD/TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) were comprehensively used to reveal the relationship between zeolite structure and catalytic properties. It was concluded that the hierarchically porous structure could not only improve the mass transfer of reactant/product but also provide larger specific surface area, higher surface acidity, larger NO adsorption capacity. And we found that bidentate nitrate species was more active in Cu-ZSM-5-meso than Cu-ZSM-5-C, which were all beneficial to the NH3-SCR reaction. This work can provide a guideline to design other high performance hierarchical zeolites with different crystalline structures (such as CHA, LTA) for efficient catalytic NOx removal processes.

16.
Int J Mol Med ; 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31746371

RESUMO

Pulmonary vascular remodeling and fibrosis are the critical pathological characteristics of hypoxic pulmonary hypertension. Our previous study demonstrated that hypoxia is involved in the functional alteration of lung fibroblasts, but the underlying mechanism has yet to be fully elucidated. The aim of the present study was to investigate the effect of mast cells on the proliferation, function and phenotype of fibroblasts under hypoxic conditions. Hypoxia facilitated proliferation and the secretion of proinflammatory cytokines, including tumor necrosis factor (TNF)­α and interleukin (IL)­6, in human mast cells (HMC­1). RNA sequencing identified 2,077 upregulated and 2,418 downregulated mRNAs in human fetal lung fibroblasts (HFL­1) cultured in hypoxic conditioned medium from HMC­1 cells compared with normoxic controls, which are involved in various pathways, including extracellular matrix organization, cell proliferation and migration. Conditioned medium from hypoxic HMC­1 cells increased the proliferation and migration capacity of HFL­1 and triggered phenotypic transition from fibroblasts to myofibroblasts. A greater accumulation of collagen type I and III was also observed in an HFL­1 cell culture in hypoxic conditioned medium from HMC­1 cells, compared with HFL­1 cells cultured in normoxic control medium. The expression of matrix metalloproteinase (MMP)­9 and MMP­13 was upregulated in HFL­1 cells grown in hypoxic conditioned medium from HMC­1 cells. Similar pathological phenomena, including accumulation of mast cells, activated collagen metabolism and vascular remodeling, were observed in a hypoxic rat model. The results of the present study provide direct evidence that the multiple effects of the hypoxic microenvironment and mast cells on fibroblasts contribute to pulmonary vascular remodeling, and this process appears to be among the most important mechanisms underlying hypoxic pulmonary hypertension.

17.
Artigo em Inglês | MEDLINE | ID: mdl-31670891

RESUMO

New symmetric and unsymmetric B,N,B-doped benzo[4]helicenes 3 - 6a/b have been achieved in good yields, using a three-step process, starting from N(tolyl) 3 in a highly divergent manner (7 examples). A borinic acid functionalized 1,4-B,N-anthracene 1 was found to display unprecedented reactivity, acting as a convenient and highly effective precursor for selective formation of bromo substituted B,N,B-benzo[4]helicenes 2a / 2b via intramolecular borylation and sequential B-Mes bond cleavage in presence of BBr 3 . Subsequent reaction of 2a / 2b with Ar-Li provided a highly effective toolbox for the preparation of symmetrically/unsymmetrically functionalized B,N,B-helicenes. Their high photoluminescence quantum yields along with the small Δ E ST suggest the potential as thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs).

18.
Medicine (Baltimore) ; 98(46): e17871, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31725630

RESUMO

RATIONALE: Primary end-to-end anastomosis is common in adult trachea resection. Nevertheless, considering that the utilization of grafts is still essential for restoring defect in long-segment tracheal resection surgery, long-segment tracheal resection and reconstruction still remain challenging. Herein we present a novel case in which we resected a large tracheal mass and reconstructed the long-segment defect through using a thyroid-pericardium flap, which has not been reported yet. PATIENT CONCERNS: A 35-year old male patient was admitted due to 'Repeated dry cough for 2 years, shortness of breath after activities for 1 month'. Patient had no other obvious symptoms. DIAGNOSES: CT revealed that a large neoplasm was located in the cervical trachea and the pedicle was in the tracheal membrane, with total length of approximately 6 cm. Positron emission tomography computed tomography demonstrated an abnormally elevated levels of glucose metabolism in the upper part of the posterior tracheal wall. Therefore, this lesion was primarily considered as a malignancy. INTERVENTIONS: The patient was performed by a primary resection of long-segment tracheal mass followed by thyroid-pericardium composite tissue flap for reconstruction. OUTCOME: The operation was successful, without hydrops or pneumatosis in the mediastinum. One week postoperatively, CT showed that there was no pneumomediastinum and mediastinal abscess. Three weeks postoperatively, fiber bronchoscope showed the flap with normal color and the unobstructed tracheal cavity. The patient healed without complication. LESSONS: The thyroid-pericardium flap is a convenient, secure, and effective material for long-segment trachea mass resection and reconstruction.

19.
J Affect Disord ; 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31727395

RESUMO

OBJECTIVE: Individuals with higher neuroticism are vulnerable to stress and are prone to develop depression, however, the neural mechanisms underlying it have not been clarified clearly. METHOD: The Montreal Imaging Stress Task (MIST) was administered to 148 healthy adults during functional magnetic resonance imaging (fMRI). Whole-brain voxel-wise regression analyses were used to detect associations of neuroticism with neural activity involved in perceiving and processing psychosocial stress. In addition, two-sample t-tests were conducted between the high-neurotic and low-neurotic group in order to supplement the results found in regression analyses. RESULTS: Higher neuroticism scores were associated with higher activities in the posterior cingulate cortex (PCC)/precuneus and thalamus (p < 0.05, false discovery rate correction). Moreover, two sample t-tests also revealed that the high-neurotic group had higher neural stress responses in precuneus and bilateral thalamus in comparison to the low-neurotic group (p < 0.05, false discovery rate correction). LIMITATIONS: Our study mainly recruited young adults, which may limit the generalizability of our findings. CONCLUSIONS: Our findings highlight the crucial role of PCC/precuneus and thalamus in the association between neuroticism and stress and may provide insight into the cognitive model of depression.

20.
J Am Chem Soc ; 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31714747

RESUMO

Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionalization. Herein, we report the development of electrochemical vinylic C-H functionalization of acrylic acids with alkynes. In this reaction an iridium catalyst enables C-H/O-H functionalization for alkyne annulation, affording α-pyrones with good to excellent yields in an undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial for releasing the product and regeneration of an Ir(III) intermediate from a diene-Ir(I) complex, which is a coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such as Ag(I) or Cu(II) did not give significant amounts of the desired product in the absence of electrical current under otherwise identical conditions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA