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1.
Virol J ; 18(1): 89, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33931105

RESUMO

BACKGROUND: A novel coronavirus (SARS-CoV-2) emerging has put global public health institutes on high alert. Little is known about the epidemiology and clinical characteristics of human coronaviruses infections in relation to infections with other respiratory viruses. METHODS: From February 2017 to December 2019, 3660 respiratory samples submitted to Zhejiang Children Hospital with acute respiratory symptoms were tested for four human coronaviruses RNA by a novel two-tube multiplex reverse transcription polymerase chain reaction assays. Samples were also screened for the occurrence of SARS-CoV-2 by reverse transcription-PCR analysis. RESULTS: Coronavirus RNAs were detected in 144 (3.93%) specimens: HCoV-HKU1 in 38 specimens, HCoV-NL63 in 62 specimens, HCoV-OC43 in 38 specimens and HCoV-229E in 8 specimens. Genomes for SARS-CoV-2 were absent in all specimens by RT-PCR analysis during the study period. The majority of HCoV infections occurred during fall months. No significant differences in gender, sample type, year were seen across species. 37.5 to 52.6% of coronaviruses detected were in specimens testing positive for other respiratory viruses. Phylogenic analysis identified that Zhejiang coronaviruses belong to multiple lineages of the coronaviruses circulating in other countries and areas. CONCLUSION: Common HCoVs may have annual peaks of circulation in fall months in the Zhejiang province, China. Genetic relatedness to the coronaviruses in other regions suggests further surveillance on human coronaviruses in clinical samples are clearly needed to understand their patterns of activity and role in the emergence of novel coronaviruses.

2.
Ergonomics ; : 1-12, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33840367

RESUMO

This study explores the impact of full windshield head-up display (FHUD) cues on the visual attention allocation of drivers under different scenarios. Forty-eight participants with driving experience were randomly divided into two groups and asked to drive on a preset route in various virtual driving scenarios created in advance. The full windshield highlights situational cues related to the driving task, such as lane lines, safe vehicle distance warnings, navigation guidance and pedestrian cues. Regarding the perception of situational cues, the number of fixations and mean fixation duration with FHUD were lower than those without FHUD. Furthermore, the dwell time percentage of the driver's forward view with FHUD was larger than that without FHUD, and the dwell time percentage on both sides was smaller than that without FHUD. In conclusion, FHUD may help drivers more effectively perceive cues and improve drivers' visual attention allocation. Practitioner summary: FHUD may affect drivers' attention while driving. We examined the effect of FHUD on number of fixations, fixation duration and dwell time percentage in the area of interest under different weather scenarios. Experimental results indicated that FHUD could improve drivers' visual attention allocation and help drivers more effectively perceive cues. Abbreviations: FHUD: full windshield head-up display; HUD: head-up display; HDD: head-down display; AOI: area of interests; AR: augmented reality.

3.
Signal Transduct Target Ther ; 6(1): 155, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33859163

RESUMO

Disease progression prediction and therapeutic drug target discovery for Coronavirus disease 2019 (COVID-19) are particularly important, as there is still no effective strategy for severe COVID-19 patient treatment. Herein, we performed multi-platform omics analysis of serial plasma and urine samples collected from patients during the course of COVID-19. Integrative analyses of these omics data revealed several potential therapeutic targets, such as ANXA1 and CLEC3B. Molecular changes in plasma indicated dysregulation of macrophage and suppression of T cell functions in severe patients compared to those in non-severe patients. Further, we chose 25 important molecular signatures as potential biomarkers for the prediction of disease severity. The prediction power was validated using corresponding urine samples and plasma samples from new COVID-19 patient cohort, with AUC reached to 0.904 and 0.988, respectively. In conclusion, our omics data proposed not only potential therapeutic targets, but also biomarkers for understanding the pathogenesis of severe COVID-19.


Assuntos
/sangue , Descoberta de Drogas , Lipidômica , Proteômica , /metabolismo , Biomarcadores/sangue , Feminino , Humanos , Masculino
4.
Cell Death Dis ; 12(4): 311, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33762579

RESUMO

The histone H3.3K36M mutation, identified in over 90% of chondroblastoma cases, reprograms the H3K36 methylation landscape and gene expression to promote tumorigenesis. However, it's still unclear how the H3K36M mutation preferentially occurs in the histone H3 variant H3.3 in chondroblastomas. Here, we report that H3.3K36M-, but not H3.1K36M-, mutant cells showed increased colony formation ability and differentiation defects. H3K36 methylations and enhancers were reprogrammed to different status in H3.3K36M- and H3.1K36M-mutant cells. The reprogramming of H3K36 methylation and enhancers was depended on the specific loci at which H3.3K36M and H3.1K36M were incorporated. Moreover, targeting H3K36M-mutant proteins to the chromatin inhibited the H3K36 methylation locally. Taken together, these results highlight the roles of the chromatic localization of H3.3K36M-mutant protein in the reprogramming of the epigenome and the subsequent induction of tumorigenesis, and shed light on the molecular mechanisms by which the H3K36M mutation mainly occurs in histone H3.3 in chondroblastomas.

5.
Eur Phys J E Soft Matter ; 44(3): 34, 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33725194

RESUMO

 Flexoelectric effect and dielectric effect in uniform lying helix (ULH) cholesteric liquid crystals under cell boundary conditions of periodic anchoring at the bottom and vertical anchoring at the top are studied. They can be quantitatively analyzed by theoretically simulation of the polar angle and the tilt angle. It is found that a good ULH texture can be formed inside under periodic boundary conditions and the bulk director is not affected by the surface anchoring strength. The induced rotation angle of the helical axis by the flexoelectric effect is slightly non-uniform with the position, and the coupling of the flexoelectric effect and dielectric effect increases the inhomogeneous change. Our results will provide an accurate theory basis for the formation of a good ULH texture and the influence of dielectric effect on the optical axis.

6.
Waste Dispos Sustain Energy ; : 1-7, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33688621

RESUMO

Incineration experiment of medical waste was carried out in a mobile animal carcass incinerator. Simulated medical waste (69% cotton, 1.5% wood product, 4.5% mask and 25% moisture) was used as raw material. The temperature trend of first and second combustion chamber, the operating conditions and the emission characteristics of gaseous pollutants were studied. The results indicated that the temperature of first combustion chamber can be maintained at 550-650 °C without external heating, while in the final stage a burner was used to realize the burnout of material. The temperature of the second combustion chamber was always lower than that of the first combustion after the burner stopped working. The concentration of CO emission in flue gas was high due to the low disposal efficiency of the mobile incinerator, while NOX and SO2 emission concentrations were far below the standard limit value (GB 18484-2001).

8.
G3 (Bethesda) ; 11(5)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33755111

RESUMO

MicroRNAs (miRNAs), a class of 22 nucleotide (nt) noncoding RNAs, negatively regulate mRNA posttranscriptional modification in various biological processes. Morphogenesis of skin hair follicles in cashmere goats is a dynamic process involving many key signaling molecules, but the associated cellular biological mechanisms induced by these key signaling molecules have not been reported. In this study, differential expression, bioinformatics, and Gene Ontology/Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on miRNA expression profiles of Inner Mongolian cashmere goats at 45, 55, and 65 days during the fetal period, and chi-miR-370-3p was identified and investigated further. Real-time fluorescence quantification (qRT-PCR), dual luciferase reporting, and Western blotting results showed that transforming growth factor beta receptor 2 (TGF-ßR2) and fibroblast growth factor receptor 2 (FGFR2) were the target genes of chi-miR-370-3p. Chi-miR-370-3p also regulated the expression of TGF-ßR2 and FGFR2 at mRNA and protein levels in epithelial cells and dermal fibroblasts. DNA staining, Cell Counting Kit-8, and fluorescein-labelled Annexin V results showed that chi-miR-370-3p inhibited the proliferation of epithelial cells and fibroblasts but had no effect on apoptosis. Cell scratch test results showed that chi-miR-370-3p promoted the migration of epithelial cells and fibroblasts. Chi-miR-370-3p inhibits the proliferation of epithelial cells and fibroblasts by targeting TGF-ßR2 and FGFR2, thereby improving cell migration ability and ultimately regulating the fate of epithelial cells and dermal fibroblasts to develop the placode and dermal condensate, inducing hair follicle morphogenesis.

9.
Phys Med Biol ; 66(9)2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33765673

RESUMO

Automated brain structures segmentation in positron emission tomography (PET) images has been widely investigated to help brain disease diagnosis and follow-up. To relieve the burden of a manual definition of volume of interest (VOI), automated atlas-based VOI definition algorithms were developed, but these algorithms mostly adopted a global optimization strategy which may not be particularly accurate for local small structures (especially the deep brain structures). This paper presents a PET/CT-based brain VOI segmentation algorithm combining anatomical atlas, local landmarks, and dual-modality information. The method incorporates local deep brain landmarks detected by the Deep Q-Network (DQN) to constrain the atlas registration process. Dual-modality PET/CT image information is also combined to improve the registration accuracy of the extracerebral contour. We compare our algorithm with the representative brain atlas registration methods based on 86 clinical PET/CT images. The proposed algorithm obtained accurate delineation of brain VOIs with an average Dice similarity score of 0.79, an average surface distance of 0.97 mm (sub-pixel level), and a volume recovery coefficient close to 1. The main advantage of our method is that it optimizes both global-scale brain matching and local-scale small structure alignment around the key landmarks, it is fully automated and produces high-quality parcellation of the brain structures from brain PET/CT images.

10.
J Comp Eff Res ; 10(6): 469-480, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33576249

RESUMO

Aim: The study assesses the cost-effectiveness of empagliflozin versus glimepiride in patients with Type 2 diabetes and uncontrolled by metformin alone in China, based on the EMPA-REG H2H-SU trial. Materials & methods: A calibrated version of the IQVIA Core Diabetes Model was used. Cost of complications and utility were taken from literature. The Chinese healthcare system perspective and 5% discounting rates were applied. Results: Empagliflozin+metformin provides additional quality-adjusted life-years (0.317) driven by a reduction in the number of cardiovascular and renal events, for an additional cost of $1382 (CNY9703) compared with glimepiride+metformin. Conclusion: Empagliflozin is cost-effective treatment versus glimepiride applying a threshold of $30,290 (CNY212,676).

11.
G3 (Bethesda) ; 11(1)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33561234

RESUMO

The development of hair follicles (HFs) is dependent on interactions between epithelial cells and dermal fibroblasts, which may play an important role in maintaining the structure of HFs during their development and maturation. Wnt family member 10 (WNT10A) is a hub gene during HF development and maturation that may regulate the proliferation of dermal fibroblasts and epithelial cells through microRNAs (miRNAs) and messenger RNAs (mRNAs) to maintain the structural stability of HFs. In the present study, we confirmed that WNT10A is the target gene of chi-miR-130b-3p by real-time quantitative PCR, western blotting, and a dual-luciferase reporter gene assay. We successfully cultured fetal epithelial cells and dermal fibroblasts using the tissue block attachment method, and Cell Counting Kit-8 (CCK8) results showed that chi-miR-130b-3p regulates epithelial cell and dermal fibroblast proliferation by targeting WNT10A.

12.
Genome Med ; 13(1): 30, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33618765

RESUMO

BACKGROUND: Since early February 2021, the causative agent of COVID-19, SARS-CoV-2, has infected over 104 million people with more than 2 million deaths according to official reports. The key to understanding the biology and virus-host interactions of SARS-CoV-2 requires the knowledge of mutation and evolution of this virus at both inter- and intra-host levels. However, despite quite a few polymorphic sites identified among SARS-CoV-2 populations, intra-host variant spectra and their evolutionary dynamics remain mostly unknown. METHODS: Using high-throughput sequencing of metatranscriptomic and hybrid captured libraries, we characterized consensus genomes and intra-host single nucleotide variations (iSNVs) of serial samples collected from eight patients with COVID-19. The distribution of iSNVs along the SARS-CoV-2 genome was analyzed and co-occurring iSNVs among COVID-19 patients were identified. We also compared the evolutionary dynamics of SARS-CoV-2 population in the respiratory tract (RT) and gastrointestinal tract (GIT). RESULTS: The 32 consensus genomes revealed the co-existence of different genotypes within the same patient. We further identified 40 intra-host single nucleotide variants (iSNVs). Most (30/40) iSNVs presented in a single patient, while ten iSNVs were found in at least two patients or identical to consensus variants. Comparing allele frequencies of the iSNVs revealed a clear genetic differentiation between intra-host populations from the respiratory tract (RT) and gastrointestinal tract (GIT), mostly driven by bottleneck events during intra-host migrations. Compared to RT populations, the GIT populations showed a better maintenance and rapid development of viral genetic diversity following the suspected intra-host bottlenecks. CONCLUSIONS: Our findings here illustrate the intra-host bottlenecks and evolutionary dynamics of SARS-CoV-2 in different anatomic sites and may provide new insights to understand the virus-host interactions of coronaviruses and other RNA viruses.


Assuntos
/prevenção & controle , Genoma Viral/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Polimorfismo de Nucleotídeo Único , /genética , /virologia , Frequência do Gene , Genótipo , Haplótipos , Interações Hospedeiro-Patógeno , Humanos , Filogenia , /fisiologia
13.
J Basic Microbiol ; 61(3): 219-229, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33555043

RESUMO

Multi-replicon plasmids harboring the IncpA1763-KPC replicon together with other replicons are being increasingly reported among Enterobacteriaceae species. However, plasmids with single IncpA1763-KPC replicons are poorly studied as a different incompatibility (Inc) group, despite their rise in appearance in some strains. IncpA1763-KPC plasmids, pA1763-KPC, and p427113-2, from two clinical Klebsiella pneumoniae isolates were fully sequenced by high-throughput genome sequencing. Linear structural comparisons of IncpA1763-KPC backbone region were made between these two plasmids and six arbitrarily selected representative IncpA1763-KPC plasmids sequenced previously. A further detailed genomic comparison was carried out between plasmids pA1763-KPC, p427113-2, and pFB2.2, which show high homology across the backbone sequence to one another. Among all sequenced IncpA1763-KPC plasmids considered in this study, plasmids pA1763-KPC and p427113-2 showed the most complete IncpA1763-KPC backbones. These were composed of the IncpA1763-KPC replicon (repAIncpA1763-KPC and its iterons), the 5.6-kb IncpA1763-KPC -type maintenance region, the 27.7-kb IncFIIK -type maintenance region, and the 36.6-kb IncFIIK -type conjugal transfer regions. Compared with pA1763-KPC or p427113-2, the backbone regions of the other analyzed IncpA1763-KPC plasmids had gradually undergone different deletions or truncations, but shared small and core IncpA1763-KPC backbones including the IncpA1763-KPC replicon, IncpA1763-KPC -type maintenance region, and residual IncFIIK -type maintenance region. Accessory modules integrated into IncpA1763-KPC backbones included the multidrug-resistant module blaKPC-2 region in pA1763-KPC, the metal-resistance modules ars region together with ncr region in pFB2.2 and sil in pKPN-9a0d, the ISKpn14-to-IS26 region in p427113-2, and other non-resistance region in the respective plasmids. This detailed comparative genomics analysis of IncpA1763-KPC plasmids provides a deep insight into their diversification and evolution.

14.
BMC Gastroenterol ; 21(1): 86, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33622273

RESUMO

BACKGROUND: Esophageal cancer is one of the most aggressive malignancies, and is associated with multiple genetic mutations. At present, the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) gene mutation has been observed in esophageal cancer and is associated with poor prognosis. This study aimed to investigate the protein expression of BRAF in esophageal cancer and determine its effect on patient outcomes. METHODS: We used immunohistochemistry to detect the expression of BRAF via tissue microarrays in esophageal cancer samples, the Kaplan-Meier method to perform survival analysis, and the Cox proportional hazards regression model to explore the risk factors of esophageal cancer. The role of BRAF in the proliferation, invasion, and metastasis of esophageal cancer was studied by clone formation, scratch test, Transwell invasion and migration test. The tumor-bearing model of BRAF inhibitor was established using TE-1 cells, and corresponding negative control was set up to observe the growth rate of the two models. RESULTS: The results revealed that BRAF overexpression was significantly correlated with Ki67 (P < 0.05). Survival analysis showed that BRAF overexpression contributed to a shorter overall survival (P = 0.014) in patients with esophageal cancer. Univariate and multivariate regression analyses demonstrated that BRAF was a prognostic factor for poor esophageal cancer outcomes (P < 0.05). Small interfering RNA knockdown of BRAF significantly reduced the cell clone formation rate compared to the control group. Transwell assay analysis showed that the migration and invasion of cells in the experimental group were significantly inhibited relative to the control group, and the inhibition rates of the small interfering RNA group were 67% and 60%, respectively. In the scratch test, the wound healing ability of the BRAF knockdown group was significantly weaker than that of the control group. There were significant differences in tumor growth volume and weight between the two groups in nude mice. CONCLUSION: BRAF overexpression may serve as an effective predictive factor for poor prognosis.

15.
Phys Med Biol ; 66(4): 04NT01, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33527911

RESUMO

The purpose of this work was to develop and evaluate a deep learning approach for automatic rat brain image segmentation of magnetic resonance imaging (MRI) images in a clinical PET/MR, providing a useful tool for analyzing studies of the pathology and progression of neurological disease and to validate new radiotracers and therapeutic agents. Rat brain PET/MR images (N = 56) were collected from a clinical PET/MR system using a dedicated small-animal imaging phased array coil. A segmentation method based on a triple cascaded convolutional neural network (CNN) was developed, where, for a rectangular region of interest covering the whole brain, the entire brain volume was outlined using a CNN, then the outlined brain was fed into the cascaded network to segment both the cerebellum and cerebrum, and finally the sub-cortical structures within the cerebrum including hippocampus, thalamus, striatum, lateral ventricles and prefrontal cortex were segmented out using the last cascaded CNN. The dice score coefficient (DSC) between manually drawn labels and predicted labels were used to quantitatively evaluate the segmentation accuracy. The proposed method achieved a mean DSC of 0.965, 0.927, 0.858, 0.594, 0.847, 0.674 and 0.838 for whole brain, cerebellum, hippocampus, lateral ventricles, striatum, prefrontal cortex and thalamus, respectively. Compared with the segmentation results reported in previous publications using atlas-based methods, the proposed method demonstrated improved performance in the whole brain and cerebellum segmentation. In conclusion, the proposed method achieved high accuracy for rat brain segmentation in MRI images from a clinical PET/MR and enabled the possibility of automatic rat brain image processing for small animal neurological research.

16.
IEEE Trans Cybern ; PP2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33544682

RESUMO

In this article, a robust adaptive output-feedback control approach is presented for a class of nonlinear output-feedback systems with parameter uncertainties and time-varying bounded disturbances. A reduced-order filter driven by control input is proposed to reconstruct unmeasured states. The state estimation error is shown to be bounded by dynamic signals driven by system output. The bound estimation technique is employed to estimate the unknown disturbance bound. Based on the backstepping design with three sets of tuning functions, an adaptive output-feedback control scheme with the flat-zone modification is proposed. It is shown that all the signals in the resulting closed-loop adaptive control systems are bounded, and the output tracking error converges to a prespecified small neighborhood of the origin. Two simulation examples are provided to illustrate the effectiveness and validity of the proposed approach.

17.
J Exp Med ; 218(4)2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33464307

RESUMO

Virus-specific T cells play essential roles in protection against multiple virus infections, including SARS-CoV and MERS-CoV. While SARS-CoV-2-specific T cells have been identified in COVID-19 patients, their role in the protection of SARS-CoV-2-infected mice is not established. Here, using mice sensitized for infection with SARS-CoV-2 by transduction with an adenovirus expressing the human receptor (Ad5-hACE2), we identified SARS-CoV-2-specific T cell epitopes recognized by CD4+ and CD8+ T cells in BALB/c and C57BL/6 mice. Virus-specific T cells were polyfunctional and were able to lyse target cells in vivo. Further, type I interferon pathway was proved to be critical for generating optimal antiviral T cell responses after SARS-CoV-2 infection. T cell vaccination alone partially protected SARS-CoV-2-infected mice from severe disease. In addition, the results demonstrated cross-reactive T cell responses between SARS-CoV and SARS-CoV-2, but not MERS-CoV, in mice. Understanding the role of the T cell response will guide immunopathogenesis studies of COVID-19 and vaccine design and validation.


Assuntos
/imunologia , Epitopos de Linfócito T/imunologia , Interações Hospedeiro-Patógeno/fisiologia , Linfócitos T/imunologia , Linfócitos T/virologia , /genética , Animais , Anticorpos Neutralizantes/sangue , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Chlorocebus aethiops , Reações Cruzadas , Mapeamento de Epitopos , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Vírus da SARS/imunologia , /patogenicidade , Células Vero
18.
Plant Biotechnol J ; 19(2): 335-350, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33448635

RESUMO

The flag leaf and grain belong to the source and sink, respectively, of cereals, and both have a bearing on final yield. Premature leaf senescence significantly reduces the photosynthetic rate and severely lowers crop yield. Cytokinins play important roles in leaf senescence and determine grain number. Here, we characterized the roles of the rice (Oryza sativa L.) cytokinin oxidase/dehydrogenase OsCKX11 in delaying leaf senescence, increasing grain number, and coordinately regulating source and sink. OsCKX11 was predominantly expressed in the roots, leaves, and panicles and was strongly induced by abscisic acid and leaf senescence. Recombinant OsCKX11 protein catalysed the degradation of various types of cytokinins but showed preference for trans-zeatin and cis-zeatin. Cytokinin levels were significantly increased in the flag leaves of osckx11 mutant compared to those of the wild type (WT). In the osckx11 mutant, the ABA-biosynthesizing genes were down-regulated and the ABA-degrading genes were up-regulated, thereby reducing the ABA levels relative to the WT. Thus, OsCKX11 functions antagonistically between cytokinins and ABA in leaf senescence. Moreover, osckx11 presented with significantly increased branch, tiller, and grain number compared with the WT. Collectively, our findings reveal that OsCKX11 simultaneously regulates photosynthesis and grain number, which may provide new insights into leaf senescence and crop molecular breeding.


Assuntos
Oryza , Ácido Abscísico , Grão Comestível , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oxirredutases/genética , Folhas de Planta
19.
Anal Chim Acta ; 1143: 144-156, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33384112

RESUMO

Monoaromatic molecules are a category of molecules containing a single aromatic ring which generally emit light in the ultraviolet (UV) region. Despite their facile preparation, the UV emission greatly limits their application as organic probes. In this study, we developed a general method to red shift the emission of monoaromatic molecules. Significant fluorescence red-shift (∼100 nm per intramolecular hydrogen bonding) can be achieved by introducing intramolecular hydrogen bonding units to benzene, a typical monoaromatic molecule. Upon increasing the number of hydrogen bonding units on the benzene ring, UV, blue, and green emissions are screened, which are switchable by simply breaking/restoration the intramolecular hydrogen bonding. As a demonstration, with the breaking of one intramolecular H-bonding, the green emission (λemmax = 533 nm) of 2,5-dihydroxyterephthalic acid (DHTA) changed to cyan (λemmax = 463 nm) upon the formation of its phosphorylated form (denoted as PDHTA), which, in the presence of alkaline phosphatase (ALP), hydrolyzed and recovered the green emission. By taking advantage of the switchable emission colors, ratiometric in vitro and endogenous ALP sensing was achieved. This general approach offers a great promise to develop organic probes with tunable emissions for fluorescence analysis and imaging by different intramolecular hydrogen bonding.

20.
J Alzheimers Dis ; 79(3): 1317-1325, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33427748

RESUMO

BACKGROUND: Florbetapir (AV45) and fluorodeoxyglucose (FDG) PET imaging are valuable techniques to detect the amyloid-ß (Aß) load and brain glucose metabolism in patients with Alzheimer's disease (AD). OBJECTIVE: The purpose of this study is to access the characteristics of Aß load and FDG metabolism in brain for further investigating their relationships with cognitive impairment in AD patients. METHODS: Twenty-seven patients with AD (average 70.6 years old, N = 13 male, N = 14 female) were enrolled in this study. These AD patients underwent the standard clinical assessment and received detailed imaging examinations of the nervous system by using Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MOCA), 18F-AV45, and 18F-FDG PET scans. RESULTS: Of 27 AD patients, 22 patients (81.5%) showed significantly increases in Aß load and 26 patients (96.3%) had significantly reductions in FDG metabolism. The moderate AD patients had more brain areas of reduced FDG metabolism and more severe reductions in some regions compared to mild AD patients, with no differences in Aß load observed. Moreover, the range and degree of reduced FDG metabolism in several regions were positively correlated with the total score of MMSE or MOCA, whereas the range of Aß load did not. No correlation was found between the range of Aß load and the range of reduced FDG metabolism in this study. CONCLUSION: The reduction in FDG metabolisms captured by 18F-FDG imaging can be used as a potential biomarker for AD diagnosis in the future. 18F-AV45 imaging did not present valuable evidence for evaluating AD patient in this study.

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