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1.
J Org Chem ; 85(2): 622-632, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31799847

RESUMO

An efficient Pd-catalyzed arylation of alkylpyridine based on the pyridinium activation strategy has been developed for synthesis of mixed aryl alkylpyridines. It was found that (1) the N-methyl group in the pyridinium salts acted as a transient activator and could be automatically departed after the reaction, (2) CuBr was an indispensable additive for achieving the C6-selective arylation, (3) the α-branched alkyl chain on the alkylpyridine greatly increased the yield of the product. Deuterium labelling experiment revealed that in the case of the α-branched alkylpyridine, the presence of CuBr completely inhibited the H/D exchange at the benzylic position and thus enabled the selective arylation at the C6 position. This protocol demonstrates a broad substrate scope, and with respect to both the aryl iodides and the α-branched alkylpyridine, the desired mixed aryl alkylpyridines were obtained in generally good to excellent yields.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 227: 117683, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31685422

RESUMO

Colorimetric sensor array is a sensitive, rapid, and inexpensive detection technology which simulates human olfaction system based on various organic dyes. In this work, a sensor array based on acid-sensitive CdTe QDs coupled with chemometrics method was developed and proved to be a rapid, accurate and sensitive method for identification of 32 kinds of Chinese traditional cereal vinegars (CTCV). The specificity of identification of this method was mainly depends on the organic acids and melanoidins of CTCV. Among them, organic acids can quench the fluorescence of QDs through enhancing their electron transfer (hydrogen bond) and resonance energy transfer, and the fluorescence intensity of melanoidin was closely related to the brewing technology and aging year of CTCV. The types and aging time of 32 CTCV can be 100% identified at a dilution of 1000 by partial least squares discriminant analysis, when the latent variables were 4. And only one kind of QDs is needed instead of various organic dyes to this kind of colorimetric sensor array. Except for vinegar, this method can also be used in the identification of other food which rich in organic acid.

3.
Technol Cancer Res Treat ; 18: 1533033819892263, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31818225

RESUMO

Non-small cell lung cancer is the most common malignant tumor in the world. Currently, chemotherapy is still the major method for non-small cell lung cancer treatment, but the problem of cancer drug resistance still exists, so we designed 5 different phosphorothioate oligonucleotides to silence key genes in tumor cell development, which could help avoid inducing cancer cell drug resistance. MicroRNAs have been shown to play a crucial role in the pathogenesis and progression of many malignancies, such as breast, colon, lung, and pancreatic cancer. According to the data from the Gene Expression Omnibus database, miR-21 has been reported to be one of the top 20 differentially expressed microRNAs screened using the Morpheus online tool, and miR-21 has been revealed to regulate a series of biological behaviors in cancer cells, including cell proliferation, migration, invasion, metastasis, and apoptosis. In recent years, gene therapy has emerged as a new therapeutic strategy for cancer treatment. Antisense oligonucleotides have recently been suggested as a novel approach for targeting microRNAs by antisense-based gene silencing. Five phosphorothioate oligonucleotides were designed, synthesized, and screened for anticancer activity. Reverse transcription-polymerase chain reaction was used to detect the relative expression of miR21. Among these 5 sequences, only phosphorothioate oligonucleotide 4 inhibited the proliferation of H1650 cells, and this effect was due to the induction of cancer cell apoptosis by activating the caspase-8 apoptotic pathway. In conclusion, this research confirmed the anticancer activity of phosphorothioate oligonucleotide 4 and revealed the underlying mechanism, which has the potential to be a novel anticancer strategy.

4.
Org Lett ; 21(23): 9425-9429, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31810112

RESUMO

A simple and efficient method for the synthesis of isoquinolone and isocoumarin derivatives is reported. The method for the first time provides a one-step divergent synthesis of important isoquinolone and isocoumarin skeletons from benzoic acid by switching the coupling partners. In addition, a reliable mechanism has been proposed on the basis of experimental investigations, including kinetic isotope effect experiments, 13C labeling experiments, time-tracking experiments, and competitive experiments, as well as DFT calculation studies.

5.
J Chromatogr A ; : 460787, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31864723

RESUMO

Automatic data analysis for gas chromatography-mass spectrometry (GC-MS) is a challenging task in untargeted metabolomics. In this work, we provide a novel comprehensive data analysis strategy for GC-MS-based untargeted metabolomics (autoGCMSDataAnal) by developing a new automatic strategy for performing TIC peak detection and resolution and proposing a novel time-shift correction and component registration algorithm. autoGCMSDataAnal uses original acquired GC-MS datafiles as input to automatically perform TIC peak detection, component resolution, time-shift correction and component registration, statistical analysis, and compound identification. We utilize standards and complex plant samples to comprehensively investigate the performance of autoGCMSDataAnal. The results suggest that the developed strategy is comparable with several state-of-the-art methods that are widely used in GC-MS-based untargeted metabolomics. Based on the proposed strategy, we develop a user-friendly MATLAB GUI for users who are unfamiliar with programming languages to facilitate their routine analysis, which can be freely downloaded at: http://software.tobaccodb.org/software/autogcmsdataanal.

6.
Zhongguo Dang Dai Er Ke Za Zhi ; 21(12): 1198-1202, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31874659

RESUMO

OBJECTIVE: To study the value of serum gamma-glutamyl transpeptidase (GGT) combined with direct bilirubin (DB) in the diagnosis of biliary atresia. METHODS: A total of 667 infants with cholestasis who were hospitalized and treated from July 2010 to December 2018 were enrolled as subjects. According to the results of intraoperative cholangiography and follow-up, they were divided into biliary atresia group with 234 infants and cholestasis group with 433 infants. The two groups were compared in terms of age of onset, sex, and serum levels of total bilirubin (TB), DB, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), and GGT. A receiver operating characteristic (ROC) curve analysis was performed for indices with statistical significance, and the area under the ROC curve (AUC) and the optimal cut-off value for diagnosis were calculated. RESULTS: The biliary atresia group had a significantly younger age of onset than the cholestasis group (P<0.001). There were no significant differences in sex, ALT, and AST between the two groups (P>0.05), while the biliary atresia group had significantly higher serum levels of TB, DB, TBA, and GGT than the cholestasis group (P<0.05). GGT combined with DB had the highest AUC of 0.892 (95% confidence interval: 0.868-0.916) in the diagnosis of biliary atresia. At the optimal cut-off values of 324.0 U/L for GGT and 115.1 µmmol/L for DB, GGT combined with DB had a sensitivity of 79.8% and a specificity of 83.2% in the diagnosis of biliary atresia. CONCLUSIONS: GGT combined with DB has high sensitivity and specificity in the diagnosis of biliary atresia and can be used as an effective indicator for diagnosis of biliary atresia in infants.


Assuntos
Atresia Biliar , gama-Glutamiltransferase/sangue , Alanina Transaminase , Aspartato Aminotransferases , Atresia Biliar/diagnóstico , Bilirrubina , Humanos , Lactente
7.
Mol Metab ; 30: 250-263, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31767176

RESUMO

BACKGROUND: Globally, diabetic kidney disease (DKD) is the leading cause of end-stage renal disease. As the most common microvascular complication of diabetes, DKD is a thorny, clinical problem in terms of its diagnosis and management. Intensive glucose control in DKD could slow down but not significantly halt disease progression. Revisiting the tremendous advances that have occurred in the field would enhance recognition of DKD pathogenesis as well as improve our understanding of translational science in DKD in this new era. SCOPE OF REVIEW: In this review, we summarize advances in the understanding of the local microenvironmental changes in diabetic kidneys and discuss the involvement of genetic and epigenetic factors in the pathogenesis of DKD. We also review DKD prevalence changes and analyze the challenges in optimizing the diagnostic approaches and management strategies for DKD in the clinic. As we enter the era of 'big data', we also explore the possibility of linking systems biology with translational medicine in DKD in the current healthcare system. MAJOR CONCLUSION: Newer understanding of the structural changes of diabetic kidneys and mechanisms of DKD pathogenesis, as well as emergent research technologies will shed light on new methods of dealing with the existing clinical challenges of DKD.

8.
JCI Insight ; 4(24)2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31743113

RESUMO

Proteinuric chronic kidney disease (CKD) remains a major health problem worldwide. While it is well established that the progression of primary glomerular disease induces tubulointerstitial lesions, how tubular injury triggers glomerular damage is poorly understood. We hypothesized that injured tubules secrete mediators that adversely affect glomerular health. To test this, we used conditional knockout mice with tubule-specific ablation of ß-catenin (Ksp-ß-cat-/-) and subjected them to chronic angiotensin II (Ang II) infusion or Adriamycin. Compared with control mice, Ksp-ß-cat-/- mice were dramatically protected from proteinuria and glomerular damage. MMP-7, a downstream target of ß-catenin, was upregulated in treated control mice, but this induction was blunted in the Ksp-ß-cat-/- littermates. Incubation of isolated glomeruli with MMP-7 ex vivo led to nephrin depletion and impaired glomerular permeability. Furthermore, MMP-7 specifically and directly degraded nephrin in cultured glomeruli or cell-free systems, and this effect was dependent on its proteolytic activity. In vivo, expression or infusion of exogenous MMP-7 caused proteinuria, and genetic ablation of MMP-7 protected mice from Ang II-induced proteinuria and glomerular injury. Collectively, these results demonstrate that ß-catenin-driven MMP-7 release from renal tubules promotes glomerular injury via direct degradation of the key slit diaphragm protein nephrin.

9.
JCI Insight ; 4(22)2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31647783

RESUMO

Glomerular disease is characterized by proteinuria and glomerulosclerosis, two pathologic features caused by podocyte injury and mesangial cell activation, respectively. However, whether these two events are linked remains elusive. Here, we report that sonic hedgehog (Shh) is the mediator that connects podocyte damage to mesangial activation and glomerulosclerosis. Shh was induced in glomerular podocytes in various models of proteinuric chronic kidney diseases (CKD). However, mesangial cells in the glomeruli, but not podocytes, responded to hedgehog ligand. In vitro, Shh was induced in podocytes after injury and selectively promoted mesangial cell activation and proliferation. In a miniorgan culture of isolated glomeruli, Shh promoted mesangial activation but did not affect the integrity of podocytes. Podocyte-specific ablation of Shh in vivo exhibited no effect on proteinuria after adriamycin injection but hampered mesangial activation and glomerulosclerosis. Consistently, pharmacologic blockade of Shh signaling decoupled proteinuria from glomerulosclerosis. In humans, Shh was upregulated in glomerular podocytes in patients with CKD and its circulating level was associated with glomerulosclerosis but not proteinuria. These studies demonstrate that Shh mechanistically links podocyte injury to mesangial activation in the pathogenesis of glomerular diseases. Our findings also illustrate a crucial role for podocyte-mesangial communication in connecting proteinuria to glomerulosclerosis.

10.
Chem Commun (Camb) ; 55(82): 12384-12387, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31559990

RESUMO

Herein, we report the first example of synthesis of N-substituted lactams via an acceptorless dehydrogenative coupling of diols with primary amines in one step, which was enabled by combining Ru3(CO)12 with a hybrid N-heterocyclic carbene-phosphine-phosphine ligand as the catalyst.

11.
Opt Express ; 27(15): 20910-20927, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31510178

RESUMO

Scratches on the surface of optical components have serious impacts on optical system such as imaging quality of lens and/or mirrors in optical imaging systems, light-collecting abilities of laser fusion and solar concentrator systems. The size of the scratches is a key issue for analyzing and assessing the impacts quantitatively. Most of the available testing methods for scratches depend on human visual inspection (HVI) with naked eyes by workers, which leads to low efficiency and accuracy. This paper presents an automatic detecting method for the scratches on optical surface with machine vision inspection (MVI) method. The microscopic dark-field scattering imaging system is used as the front end of the detection system. A dedicated algorithm is designed for non-closing scratch detection. The core merits of this algorithm lies in three folds: 1) automatic processing capabilities, which includes positioning, clustering, and precise estimation of the length of the scratches; 2) high efficiency, which is characterized by a short time interval, i.e., about 0.138 second per binary image with 2724 × 2724 pixels in our experiments; 3) high accuracy, where the error rate of the total length of the scratches detected is less than 5% when compared with the nominal visual measurement result obtained via HVI method. The proposed scratch detecting algorithm can be used for non-destructive testing (NDT) of the glass-like surfaces.

12.
FASEB J ; 33(11): 12576-12587, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31461626

RESUMO

Acute kidney injury (AKI) is a devastating condition with high morbidity and mortality. AKI is characterized by tubular injury, inflammation, and vascular impairment. However, the role of interstitial fibroblasts in the pathogenesis of AKI is largely unknown. Here, we show that fibroblasts were activated, as defined by vimentin expression, at 1 h after AKI triggered by ischemia-reperfusion injury (IRI). They rapidly entered the cell cycle with Ki-67-positive staining, which started at 1 h and peaked at 12 h after IRI, whereas tubular cell proliferation peaked at 3 d. The trigger for such an early activation of fibroblasts was identified as sonic hedgehog (Shh), which was rapidly induced in renal tubules and could target interstitial fibroblasts. Tubule-specific knockout of Shh in mice inhibited fibroblast activation and aggravated kidney injury and functional decline after IRI. Likewise, pharmacologic inhibition of Shh signaling with cyclopamine also hindered fibroblast activation and exacerbated kidney damage. These studies uncover that tubule-derived Shh triggers the early activation of fibroblasts, which is required for kidney repair and regeneration. Our findings for the first time illustrate a previously unrecognized importance of interstitial fibroblasts in conferring renal protection in AKI.-Zhou, D., Fu, H., Liu, S., Zhang, L., Xiao, L., Bastacky, S. I., Liu, Y. Early activation of fibroblasts is required for kidney repair and regeneration after injury.

13.
J Anal Methods Chem ; 2019: 2796502, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31380141

RESUMO

The feasibility of combining elemental fingerprints and chemical pattern recognition methods for authentication of the geographical origins of a Chinese herb, Gastrodia elata BI. (GE), was studied in this paper. A total of 210 GE samples were collected from 7 different producing areas. The levels of 15 mineral elements in GE, including Zn, Cd, Co, Cr, Cu, Ca, Mg, Mn, Mo, Ni, Pb, Sr, Fe, Na, and K, were determined using inductively coupled plasma mass spectrometry (ICP-MS). Using the autoscaled data of elemental fingerprints and partial least-squares discriminant analysis (PLSDA), two chemometrics strategies for multiclass classifications, One-Versus-Rest (OVR) and One-Versus-One (OVO), were studied and compared in discrimination of GE geographical origins. As a result, OVR-PLSDA and OVO-PLSDA could achieve the classification accuracy of 0.672 and 0.925, respectively. The results indicate that mineral elemental fingerprints coupled with chemometrics can provide a useful alternative method for simultaneous discrimination of multiple GE geographical origins.

14.
Int Immunopharmacol ; 75: 105768, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31382166

RESUMO

Ulcerative colitis (UC) is a major inflammatory bowel disease (IBD) which has become a global public health problem. Limonin is a triterpenoid extracted from citrus which possesses the capacities to against inflammations and cell apoptosis. However, the efficacy and the underlying mechanisms of limonin in the treatment of UC remain unclear. In this study, we first investigated the therapeutic effects of limonin on dextran sodiumsulfate (DSS)-induced UC in vivo by examining the changes of disease activity index (DAI), the colon length, the colon histology, and cyto/chemokine levels. We found that limonin markedly reduced DAI, intestinal damages, and the levels of pro-inflammatory cytokines, such as TNF-α and IL-6. In vitro, limonin significantly repressed the productions of pro-inflammatory cytokines in cultured normal colonic epithelial cells. Mechanistically, we demonstrated that limonin improved the prognosis of UC mainly through downregulating p-STAT3/miR-214 levels. Collectively, our results suggested that limonin was a novel therapeutic agent and it was expected to be translated into the clinic to improve the prognosis of UC.

15.
J Org Chem ; 84(14): 9151-9160, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31273988

RESUMO

A selective catalytic system for the dehydrogenation of primary alcohols to carboxylic acids using a facial ruthenium complex generated in situ from the [Ru(COD)Cl2]n and a hybrid N-heterocyclic carbene (NHC)-phosphine-phosphine ligand (CPP) has been first reported. The facial coordination model was unveiled by NMR analysis of the reaction mixture. Such a fac-ruthenium catalyst system exhibited high catalytic activity and stability, and a high turnover number of 20 000 could be achieved with catalyst loading as low as 0.002 mol %. The exceedingly high catalyst stability was tentatively attributed to both the anchoring role of NHC and the hemi-lability of phosphines. The catalytic system also features a wide substrate scope. In particular, the facial coordination of CPP ligands was found to be beneficial for sterically hindered alcohols, and ortho-substituted benzylic alcohols and bulky adamantanyl methanol as well as cholesterol were all found to be viable dehydrogenation substrates.

16.
Mol Ther Methods Clin Dev ; 13: 453-462, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31193101

RESUMO

Widespread anti-AAV antibodies (Abs) in humans pose a critical challenge for the translation of AAV gene therapies, limiting patient eligibility. In this study, non-human primates (NHPs) with pre-existing αAAV Abs were used to investigate the impact of αAAV9 Ab levels on the transduction efficiency of rAAV9 via systemic delivery. No significant differences were observed in vector genome (vg) biodistribution in animals with ≤1:400 total serum αAAV9-IgG compared to αAAV9-Ab-negative animals, following an intravenous (i.v.) rAAV9-hNAGLU op (codon-optimized human α-N-acetylglucosaminidase coding sequence cDNA) injection. Serum αAAV9-IgG at >1:400 resulted in a >200-fold decrease in vg in the liver, but had no significant effect on vg levels in brain and most of the peripheral tissues. Although tissue NAGLU activities declined significantly, they remained above endogenous levels. Notably, there were higher vg copies but lower NAGLU activity in the spleen in NHPs with >1:400 αAAV9 Abs than in those with ≤1:400 Abs. We demonstrate here the presence of a threshold of pre-existing αAAV9 Abs for diminishing the transduction of i.v.-delivered AAV vectors, supporting the expansion of patient eligibility for systemic rAAV treatments. Our data also indicate that high pre-existing αAAV9 Abs may promote phagocytosis and that phagocytized vectors are not processed for transgene expression, suggesting that effectively suppressing innate immunity may have positive impacts on transduction efficiency in individuals with high Ab titers.

17.
Spectrochim Acta A Mol Biomol Spectrosc ; 221: 117212, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31158771

RESUMO

To enhance the power of untargeted detection, a "turn-off" fluorescent probe with double quantum dots (QDs) was developed and coupled with chemometrics for rapid detection of multiple adulterants in an herbal (Rhus chinensis Mill., RCM) honey. The double water-soluble ZnCdSe-CdTe QDs have two separate and strong fluorescent peaks, which can be quenched by honey and extraneous adulterants with varying degrees. Class models of pure RCM honey samples collected from 6 different producing areas (n = 122) were developed using one-class partial least squares (OCPLS). Four extraneous adulterants, including glucose syrup, sucrose syrup, fructose syrup, and glucose-fructose syrup were added to pure honey samples at the levels of 0.5% to 10% (w/w). As a result, the OCPLS model using the second-order derivative (D2) spectra could detect 1.0% (w/w) of different syrups in RCM honey, with a sensitivity of 0.949. The double water-soluble QDs, which can be adjusted for analysis of other water-soluble food samples, has largely extended the capability of traditional fluorescence and will provide a potentially more sensitive and specific analysis method for food frauds.


Assuntos
Corantes Fluorescentes/química , Contaminação de Alimentos/análise , Mel/análise , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Compostos de Cádmio/química , China , Glucose/química , Análise dos Mínimos Quadrados , Modelos Estatísticos , Compostos de Selênio/química , Sensibilidade e Especificidade , Solubilidade , Espectrometria de Fluorescência/estatística & dados numéricos , Sacarose/química , Telúrio/química , Compostos de Zinco/química
18.
Medicine (Baltimore) ; 98(22): e15708, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31145285

RESUMO

RATIONALE: Cholestasis in pediatric patients has diverse etiologies and can be broadly classified as intrahepatic or extrahepatic. The common causes of extrahepatic cholestasis are bile duct calculus, inflammation, or pancreatitis. Malignant tumor is a rare cause of bile ducts obstruction in adolescent. Here we report a 14-year-old male patient with cholestasis due to poorly differentiated adenocarcinoma. PATIENT CONCERNS: A 14-year-old male patient with cholestasis was admitted because of jaundice, weakness, weight loss, and stomach pain for 2 months. The patient had been diagnosed with epilepsy 4 years previously and was being treated with sodium valproate and oxcarbazepine. On admission, laboratory studies showed elevated levels of aspartate aminotransferase (271 IU/L), alanine aminotransferase (224 IU/l), γ-glutamyltransferase (1668.9 IU/L), total bilirubin (66.4 µmol/L), and direct bilirubin (52.6 µmol/L). Additional laboratory tests eliminated common causes of cholestasis such as bacterial/viral infection, autoimmune liver disease, Wilson disease, Alagille syndrome, or progressive familial intrahepatic cholestasis type 3. The results of laboratory investigations showed no improvement after 10 days of treatment with ursodeoxycholic acid and vitamins A, D, and K1. Enhanced magnetic resonance imaging demonstrated a tumor of 22 mm diameter in the duodenal lumen and dilatation of the common bile duct. Endoscopic retrograde cholangiopancreatography detected a tumor in the duodenal lumen. DIAGNOSIS: Considering the clinical features, imaging manifestation, endoscopic findings, and pathologic characteristic, the patient was diagnosed with poorly differentiated adenocarcinoma. INTERVENTIONS: The patient underwent pancreaticoduodenectomy and chemotherapy. OUTCOME: The patient recovered well. Elevated levels of tumor biomarkers or abnormal liver function tests have not occurred during the 2-year follow-up. CONCLUSION: Cholestasis resulting from primary duodenal papillary carcinoma is rare in pediatric patients but should be considered in the differential diagnosis.


Assuntos
Ampola Hepatopancreática/patologia , Carcinoma Papilar/complicações , Colestase/etiologia , Neoplasias Duodenais/complicações , Adolescente , Carcinoma Papilar/patologia , Colestase/patologia , Neoplasias Duodenais/patologia , Humanos , Masculino
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 220: 117109, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31141775

RESUMO

Carbon quantum dots (CQDs), especially originated from biomass, have emerged as a rising star for the construction of metal ion sensor because they can serve as sensitive, selective and biocompatible probes. The present work describes a novel kind of ascorbic acid (AA)-enhanced CQDs which are synthesized with a kind of famous green teas, Maojian, serving as carbon source. Compared with the CQDs only based on Maojian teas, citric acid (CA)-enhanced and ascorbic acid (AA)-enhanced CQDs had the enhanced fluorescence intensity, and different response characteristics. In addition, the (AA)-enhanced CQDs showed more sensitive and specific fluorescence response to Hg2+ than simple ones, with a detection limit of 6.32 × 10-9 nmol·L-1. A linear response range from 2.00 × 10-7 mol·L-1 to 6.00 × 10-5 mol·L-1 was also achieved. The (AA)-enhanced CQDs also demonstrate good stability. They could effectively sense the Hg2+ in complex samples including waste water, tea and rice. Therefore, these versatile (AA)-enhanced CQDs fluorescence method hold a promising potential in other promising applications such as pharmaceutical quality, environmental quality, and food safety monitoring.


Assuntos
Mercúrio/análise , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Antioxidantes/química , Ácido Ascórbico/química , Camellia sinensis/química , Carbono/química , Ácido Cítrico/química , Fluorescência , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Limite de Detecção , Oryza/química , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Chá/química , Águas Residuárias/análise
20.
IEEE Trans Cybern ; 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31107671

RESUMO

Cross-media hashing, which maps data from different modalities to a low-dimensional sharing Hamming space, has attracted considerable attention due to the rapid increase of multimodal data, for example, images and texts. Recent cross-media hashing works mainly aim at learning compact hash codes to preserve the class label-based or feature-based similarities among samples. However, these methods ignore the unbalanced semantic gaps between different modalities and high-level semantic concepts, which generally results in less effective hash functions and unsatisfying retrieval performance. Specifically, the key words of texts contain semantic meanings, while the low-level features of images lack of semantic meanings. That means the semantic gap in image modality is larger than that in text modality. In this paper, we propose a simple yet effective hashing method for cross-media retrieval to address this problem, dubbed discrete semantic alignment hashing (DSAH). First, DSAH formulates to exploit collaborative filtering to mine the relations between class labels and hash codes, which can reduce memory consumption and computational cost compared to pairwise similarity. Then, the attribute of image modality is employed to align the semantic information with text modality. Finally, to further improve the quality of hash codes, we propose a discrete optimization algorithm to learn discrete hash codes directly, and each bit has a closed-form solution. Extensive experiments on multiple public databases show that our model can seamlessly incorporate attributes and achieve promising performance.

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