Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 143
Filtrar
1.
J Am Chem Soc ; 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32510205

RESUMO

Concerns about the toxicity of lead-based perovskites have aroused great interest for the development of alternative lead-free perovskite-type materials. Recently, theoretical calculations predict that Pb2+ cations can be substituted by a combination of Cu2+ and Sb3+ cations to form a vacancy-ordered layered double perovskite structure with superior optoelectronic properties. However, accessibilities to this class of perovskite-type materials remain inadequate, hindering their practical implementations in various applications. Here, we report the first colloidal synthesis of Cs4CuSb2Cl12 perovskite-type nanocrystals (NCs). The resulting NCs exhibit a layered double perovskite structure with ordered vacancies and a direct band gap of 1.79 eV. A composition-structure-property relationship has been established by investigating a series of Cs4CuxAg2-2xSb2Cl12 perovskite-type NCs (0 ≤ x ≤ 1). The composition induced crystal structure transformation, and thus, the electronic band gap evolution has been explored by experimental observations and further confirmed by theoretical calculations. Taking advantage of both the unique electronic structure and solution processability, we demonstrate that the Cs4CuSb2Cl12 NCs can be solution-processed as high-speed photodetectors with ultrafast photoresponse and narrow bandwidth. We anticipate that our study will prompt future research to design and fabricate novel and high-performance lead-free perovskite-type NCs for a range of applications.

2.
Eur Radiol ; 30(7): 3603-3608, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32300968

RESUMO

Since a novel coronavirus was discovered from a cluster of patients with emerging pneumonia of unknown etiology in Wuhan, China, it has spread rapidly through droplet and contact transmission. Recently, the novel coronavirus pneumonia which was named COVID-19 by the World Health Organization (WHO) has been raised as a worldwide problem. Radiological examinations were confirmed as effective methods for the screening and diagnosis of COVID-19. It is reported that some radiologists and radiological technologists were infected when giving examinations to the patients with COVID-19. In order to reduce the infection risk of medical staff in radiology department, we summarized the experience on prevention and control measures in radiology department for COVID-19, aiming to guide the prevention and practical work for radiologists and radiological technologists. KEY POINTS: • The novel coronavirus spreads rapidly through droplet and contact transmission. • Radiologists and radiological technologists were possibly infected by patients. • Prevention and control measures in radiology department for COVID-19 are important.

3.
Invest Radiol ; 55(7): 412-421, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32304402

RESUMO

OBJECTIVES: The aim of this study was to assess the clinical severity of COVID-19 pneumonia using qualitative and/or quantitative chest computed tomography (CT) indicators and identify the CT characteristics of critical cases. MATERIALS AND METHODS: Fifty-one patients with COVID-19 pneumonia including ordinary cases (group A, n = 12), severe cases (group B, n = 15), and critical cases (group C, n = 24) were retrospectively enrolled. The qualitative and quantitative indicators from chest CT were recorded and compared using Fisher exact test, one-way analysis of variance, Kruskal-Wallis H test, and receiver operating characteristic analysis. RESULTS: Depending on the severity of the disease, the number of involved lung segments and lobes, the frequencies of consolidation, crazy-paving pattern, and air bronchogram increased in more severe cases. Qualitative indicators including total severity score for the whole lung and total score for crazy-paving and consolidation could distinguish groups B and C from A (69% sensitivity, 83% specificity, and 73% accuracy) but were similar between group B and group C. Combined qualitative and quantitative indicators could distinguish these 3 groups with high sensitivity (B + C vs A, 90%; C vs B, 92%), specificity (100%, 87%), and accuracy (92%, 90%). Critical cases had higher total severity score (>10) and higher total score for crazy-paving and consolidation (>4) than ordinary cases, and had higher mean lung density (>-779 HU) and full width at half maximum (>128 HU) but lower relative volume of normal lung density (≦50%) than ordinary/severe cases. In our critical cases, 8 patients with relative volume of normal lung density smaller than 40% received mechanical ventilation for supportive treatment, and 2 of them had died. CONCLUSIONS: A rapid, accurate severity assessment of COVID-19 pneumonia based on chest CT would be feasible and could provide help for making management decisions, especially for the critical cases.

4.
Cancer Imaging ; 20(1): 15, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024553

RESUMO

BACKGROUND: Mature cystic teratoma (MCT) with meningioma of the ovary is a very rare benign tumor. There is only 3 reports of this disease until June 2019. The aim of the present study was to describe a ovarian mature cystic teratoma containing meningioma and nests of neuroblasts in a 15-year-old girl. METHODS: The method used in the present study consists of description of the clinical history, image lab features, and pathological result. RESULTS: The patient complained of a 2-month history of irregular vaginal bleeding. Abdominal computed tomography (CT) showed a large oval cystic-solid mass with septations and fat density shadow, in abdomen pelvic cavity. The cystic part was the main component in the mass. The tumoral solid parts and its internal division could be seen intensified from slight to moderate on contrast-enhanced CT images compared with those on precontrast images, and the solid parts showed heterogeneous enhancement. Neighbouring intestinal tract and the uterus displaced by compression. The pathological examination confirmed the diagnosis. CONCLUSIONS: The clinical feature of ovarian mature cystic teratoma with meningioma includes a lack of specificity. Only meticulous recording of the gross features, histopathological examination including immunohistochemistry and supportive clinical and radiological findings to arrive at a correct diagnosis in case of unconventional tumours. If necessary, preoperative puncture can be performed.


Assuntos
Neoplasias Meníngeas/diagnóstico por imagem , Meningioma/diagnóstico por imagem , Neoplasias Ovarianas/diagnóstico por imagem , Teratoma/diagnóstico por imagem , Adolescente , Feminino , Humanos , Neoplasias Meníngeas/complicações , Neoplasias Meníngeas/patologia , Meningioma/complicações , Meningioma/patologia , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/patologia , Teratoma/complicações , Teratoma/patologia , Tomografia Computadorizada por Raios X
5.
Int J Nanomedicine ; 15: 315-332, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32021182

RESUMO

Purpose: The clinical outcome of spinal cord injury is usually poor due to the lack of axonal regeneration and glia scar formation. As one of the most classical supporting cells in neural regeneration, Schwann cells (SCs) provide bioactive substrates for axonal migration and release molecules that regulate axonal growth. However, the effect of SC transplantation is limited by their poor migration capacity in the astrocyte-rich central nervous system. Methods: In this study, we first magnetofected SCs with chondroitinase ABC-polyethylenimine functionalized superparamagnetic iron oxide nanoparticles (ChABC/PEI-SPIONs) to induce overexpression of ChABC for the removal of chondroitin sulfate proteoglycans. These are inhibitory factors and forming a dense scar that acts as a barrier to the regenerating axons. In vitro, we observed the migration of SCs in the region of astrocytes after the application of a stable external magnetic field. Results: We found that magnetofection with ChABC/PEI-SPIONs significantly up-regulated the expression of ChABC in SCs. Under the driven effect of the directional magnetic field (MF), the migration of magnetofected SCs was enhanced in the direction of the magnetic force. The number of SCs with ChABC/PEI-SPIONs migrated and the distance of migration into the astrocyte region was significantly increased. The number of SCs with ChABC/PEI-SPIONs that migrated into the astrocyte region was 11.6- and 4.6-fold higher than those observed for the intact control and non-MF groups, respectively. Furthermore, it was found that SCs with ChABC/PEI-SPIONs were in close contact with astrocytes and no longer formed boundaries in the presence of MF. Conclusion: The mobility of the SCs with ChABC/PEI-SPIONs was enhanced along the axis of MF, holding the potential to promote nerve regeneration by providing a bioactive microenvironment and relieving glial obstruction to axonal regeneration in the treatment of spinal cord injury.


Assuntos
Astrócitos/fisiologia , Condroitina ABC Liase/metabolismo , Nanopartículas de Magnetita/uso terapêutico , Regeneração Nervosa/fisiologia , Células de Schwann/fisiologia , Animais , Astrócitos/citologia , Axônios/efeitos dos fármacos , Movimento Celular , Células Cultivadas , Condroitina ABC Liase/genética , Condroitina ABC Liase/farmacologia , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Feminino , Campos Magnéticos , Nanopartículas de Magnetita/química , Masculino , Regeneração Nervosa/efeitos dos fármacos , Polietilenoimina/química , Ratos , Ratos Sprague-Dawley , Células de Schwann/citologia , Traumatismos da Medula Espinal/terapia
6.
Eur Radiol ; 30(4): 2324-2333, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31953668

RESUMO

OBJECTIVES: To build a dual-energy CT (DECT)-based deep learning radiomics nomogram for lymph node metastasis (LNM) prediction in gastric cancer. MATERIALS AND METHODS: Preoperative DECT images were retrospectively collected from 204 pathologically confirmed cases of gastric adenocarcinoma (mean age, 58 years; range, 28-81 years; 157 men [mean age, 60 years; range, 28-81 years] and 47 women [mean age, 54 years; range, 28-79 years]) between November 2011 and October 2018, They were divided into training (n = 136) and test (n = 68) sets. Radiomics features were extracted from monochromatic images at arterial phase (AP) and venous phase (VP). Clinical information, CT parameters, and follow-up data were collected. A radiomics nomogram for LNM prediction was built using deep learning approach and evaluated in test set using ROC analysis. Its prognostic performance was determined with Harrell's concordance index (C-index) based on patients' outcomes. RESULTS: The dual-energy CT radiomics signature was associated with LNM in two sets (Mann-Whitney U test, p < 0.001) and an achieved area under the ROC curve (AUC) of 0.71 for AP and 0.76 for VP in test set. The nomogram incorporated the two radiomics signatures and CT-reported lymph node status exhibited AUCs of 0.84 in the training set and 0.82 in the test set. The C-indices of the nomogram for progression-free survival and overall survival prediction were 0.64 (p = 0.004) and 0.67 (p = 0.002). CONCLUSION: The DECT-based deep learning radiomics nomogram showed good performance in predicting LNM in gastric cancer. Furthermore, it was significantly associated with patients' prognosis. KEY POINTS: • This study investigated the value of deep learning dual-energy CT-based radiomics in predicting lymph node metastasis in gastric cancer. • The dual-energy CT-based radiomics nomogram outweighed the single-energy model and the clinical model. • The nomogram also exhibited a significant prognostic ability for patient survival and enriched radiomics studies.

7.
Oncol Rep ; 43(1): 87-98, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31789422

RESUMO

The differential expression of a featured set of genes may serve as a diagnostic biomarker in hepatocellular carcinoma (HCC) patients. The aim of this study was to identify prognostic biomarkers for the diagnosis and survival of HCC based on the analysis of a large cohort of patients. Clinical and RNA­seq data were obtained from The Cancer Genome Atlas (TCGA) database. A transcriptomics analysis was conducted to detect differentially expressed genes (DEGs). Samples from 53 tumors and 20 normal tissues of HCC patients were obtained to further analyze the connection between overall survival (OS) and DEG levels. Based on the OS and progression­free survival (PFS), 4 DEGs (GABRR1, SOX11, COL24A1 and MYLK2) were identified from the TCGA dataset. Using gene ontology (GO) analysis, it was demonstrated that the DEGs were associated with several biological processes, including multicellular organismal and single­multicellular organism processes, which are involved in the development and migration of HCC. In addition, the four genes were significantly upregulated in tumor tissues. Notably, the mRNA expression of the four genes had a negative association with OS and PFS in HCC patients determined using a Kaplan­Meir analysis. The four­gene signature is a potential novel biomarker for the prediction of HCC patient survival.

8.
Bioorg Chem ; 95: 103530, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31887477

RESUMO

The selenoprotein thioredoxin reductases (TrxRs) have been extensively studied as a potential target for the development of anticancer drugs. Herein, we designed, synthesized, and evaluated a series of coumarin-chalcone hybrids as TrxR inhibitors. Most of them exhibited enhancing anticancer activity than Xanthohumol (Xn). The representative Xn-2 (IC50 = 3.6 µM) was a fluorescence agent, wherein drug uptake can be readily monitored in living cells by red fluorescence imaging. Xn-2 down-regulated the expression of TrxR, remarkedly induced ROS accumulation to activate mitochondrial apoptosis pathway. Furthermore, Xn-2 inhibited cancer cell metastasis and abolished the colony formation ability of cancer cells. Taken together, these results highlight that compound Xn-2 may be a promising theranostic TrxR inhibitor for human cancer therapy.

9.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 37(6): 631-635, 2019 Dec 01.
Artigo em Chinês | MEDLINE | ID: mdl-31875442

RESUMO

OBJECTIVE: This study aimed to investigate the value of normalized iodine concentration (NIC), spectral attenuation curve slope (SACS), area under curve (AUC), and iodine concentration difference (ICD) generated from spectral CT in the assessment of parotid gland tumors. METHODS: Ninety-two patients with pathologically confirmed parotid gland tumors underwent arterial phase- and venous phase-enhanced CT in spectral CT. The patients were divided into the pleomor-phic adenoma group (group A), Warthin tumor group (group B), basal cell tumor group (group C), and malignant tumor group (group D). The SACS, AUC, NIC, ICD were measured and analyzed. Statistical analyses were performed by one-way ANOVA, and statistical significance was set at P<0.05. RESULTS: SACS(AP), AUC(AP), and NIC(AP) in group A were lower than those in other groups; SACS(VP) and AUC(VP) in group C were higher than those in other groups; NIC(AP) and NIC(VP) in group D were higher than those in other groups; and ICD in group B was a positive number. The difference in SACS(AP) and AUC(AP) in groups B and C, SACS(VP) and AUC(VP) in groups C and D, and ICD in groups A and C were not statistically significant. By contrast, the diffe-rence between the other groups was statistically significant (P<0.05). The difference in NIC(AP) between groups A and B and groups C and D and the difference in NIC(VP) between groups A and C, groups A and D, and groups B and C were statistically significant (P=0.005, 0.025, 0.002, 0.038, and 0.049, respectively). CONCLUSIONS: Multi-quantitative parameters from spectral CT might be helpful in differentiating various types of parotid gland tumors.


Assuntos
Iodo , Tomografia Computadorizada por Raios X , Diagnóstico Diferencial , Humanos , Glândula Parótida
10.
ACS Appl Mater Interfaces ; 11(51): 48551-48555, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31782302

RESUMO

The photophysics of charge-transfer and recombination mechanisms in a heterojunction structure of CdSe/CdS/Au quantum dots (QDs) are studied by temperature-dependent steady-state photoluminescence (PL) and time-resolved PL (TRPL). We manipulate the charge transfer from core to shell surface by varying the tunneling barrier height resulting from temperature variation and the barrier width resulting from shell thickness variation. The charge-transfer process, which can be described by a tunneling transmission model, is manifested by two competitive recombination processes, an intrinsic exciton emission and a trap emission in the near-infrared (NIR) range. Our study establishes the photophysics foundation for the core/shell/metal application in photocatalyst and optoelectronics.

11.
Quant Imaging Med Surg ; 9(6): 1095-1102, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31367563

RESUMO

Background: Osteoporosis, obesity, and fatty liver are increasingly common chronic diseases that seriously threaten people's health. Low-dose chest computed tomography (LDCT) scan is frequently used for lung cancer screening in health screenings and checkups. Quantitative computed tomography (QCT) enables the accurate measurement of volumetric bone mineral density (vBMD), liver fat content, and abdominal fat area using the existing LDCT data without extra radiation. We initiated a new project, the China Health Big Data (China Biobank), which combines the LDCT scan images from lung cancer screening of participants in health checkup with QCT to investigate the added value of QCT to LDCT, in order to establish the normative reference database and diagnosis criteria for the three aforementioned conditions. Methods: The China Biobank project is a prospective nationwide multicenter cohort study that will combine QCT technology with LDCT scans to measure bone mineral density (BMD), intra-abdominal fat distribution, and liver fat content of the generally healthy checkup participants. Mindways QCT calibration phantom (Mindways Software Inc., Austin, TX, USA) and analysis software QCT PRO v6.0 will be used for all centers. Before data collection begins, the European Spine Phantom (ESP) will be used for quality control analysis at each collaborating center. The inclusion criteria are a healthy checkup participant aged 30-90 years, with LDCT as a part of his/her health checkup protocol. Exclusion criteria are pregnant women or participants with a metal implant in the CT scan area. The LDCT images will be transferred to the Mindways workstation for analysis, and vBMD in the L1 and L2 vertebrae, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and liver fat content will be measured. As part of the health checkup, the demographic, anthropometric parameters, blood pressure, and a routine blood laboratory test will be collected. The estimated sample size will be about 30,000. Results: The combination of QCT with LDCT of the chest was validated in this project. The vBMD of spine, visceral fat and liver fat can be measured with a LDCT chest scan. Conclusions: The China Biobank project will assess the added value of QCT to LDCT, and enable accurate evaluation of the prevalence of osteoporosis, obesity, and fatty liver disease in a very large Chinese cohort.

12.
Stem Cells Int ; 2019: 1705629, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467558

RESUMO

Adipose stem cells (ASCs) are an attractive cell source for treating many human diseases including osteoporosis. However, the molecular mechanisms accounting for ASC osteogenesis are poorly known. In this study, ASCs were first isolated from the fat tissues from the patients with osteoporosis. The global transcriptome profile between osteogenic differentiated ASCs and undifferentiated ASCs was compared using RNA sequencing (RNA-seq). Then, bioinformatic analysis was performed to reveal the central genes and pathways that regulated the osteogenic differentiation of ASCs. One of the interested genes C5AR1 was chosen for further investigation. A total of 1521 upregulated and 3020 downregulated genes were identified between the ASCs with osteogenic induction and controls. Functional gene ontology analysis revealed that these significantly differentially expressed genes (DEGs) were associated with cell cycle, protein binding, and nucleotide binding. Pathway analysis showed that many canonical pathways, such as the MAPK signaling pathway and the PI3K-AKT pathway, might actively be involved in regulating osteogenic differentiation of ASCs. A total of three subnetworks and 20 central nodes were identified by the protein-protein interaction analysis. In addition, the expression level of C5AR1 was significantly increased during osteogenic differentiation of ASCs. The downregulation of C5AR1 dramatically reduced the expression levels of osteogenic differentiation biomarkers and calcium nodule formation capacity. Collectively, we have provided a number of novel genes and pathways that might be indispensable for ASC osteogenic differentiation. Manipulating the levels of this candidate gene might contribute to the osteoporosis therapy.

13.
J Comput Assist Tomogr ; 43(5): 721-728, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31356519

RESUMO

OBJECTIVE: This study aimed to investigate the predictive and prognostic values of repeated spectral computed tomographic (CT) parameter changes for the prediction of treatment responses to the angiogenesis inhibitor AL3818 in hepatic tumors. METHODS: A total of 30 rabbits with VX2 hepatic tumors that underwent spectral contrast-enhanced abdominal CT before and during treatment were included in the study. The percent change (Δ, %) of the normalized iodine concentration (nIC) during the arterial phase (AP) and venous phase (VP) was used to predict the tumor response and to calculate the overall survival (OS). The threshold of the nIC for tumor response prediction and prognostic significance was determined by a receiver operating characteristic curve and Kaplan-Meier analysis. RESULTS: After treatment, there were 43% (13/30) responders and 57% (17/30) nonresponders. When ΔnICAP ≥ -13.10% was used as the threshold, the sensitivity and specificity for the prediction of tumor response were 82.41% and 92.31%, respectively. ΔnICVP resulted in 88.20% sensitivity and 76.92% specificity for cutoff values ≥10.78%. Kaplan-Meier analyses showed that high ΔnICAP and ΔnICVP were associated with improved OS. CONCLUSIONS: The current study shows the capability of the changes (Δ) in repeated spectral CT parameters to predict the tumor response during antiangiogenesis therapy in small hepatic tumors. ΔnICAP and ΔnICVP were predictors for treatment response and were associated with OS.


Assuntos
Inibidores da Angiogênese/farmacologia , Indóis/farmacologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/tratamento farmacológico , Quinolinas/farmacologia , Tomografia Computadorizada por Raios X , Animais , Meios de Contraste , Modelos Animais de Doenças , Iohexol/análogos & derivados , Valor Preditivo dos Testes , Prognóstico , Coelhos , Interpretação de Imagem Radiográfica Assistida por Computador
14.
Nano Lett ; 19(7): 4804-4810, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31244231

RESUMO

In this report, we show that a new mechanism for carrier transport in solution-processed colloidal semiconductor nanocrystal arrays exists at high excitation intensity on ultrafast time scales and allows for facile intrinsic transport between as-prepared nanocrystals over long distances. By combining a high speed photoconductive switch with an ultrafast laser excitation in a sub-40 ps photoconductor, we observed transient photocurrents with peak densities of 3 × 104 - 106 mA/cm2 in self-assembled PbSe nanocrystals capped with long native oleic acid ligands. The ratio between the transient photocurrent peak and the steady-state dark current is 10 orders of magnitude. The transient mobility at the peak current is estimated to range between 0.5-17.5 cm2/(V s) for the various nanocrystal sizes studied, which is 6 to 9 orders of magnitude higher than the dark current steady-state mobility in PbSe, CdSe, and CdTe nanocrystals capped with native ligands. The results are analyzed using a kinetic model which attributes the ultrahigh transient photocurrent to multiple photogenerated excitons undergoing on-particle Auger recombination, followed by rapid tunneling at high energies. This mechanism is demonstrated for a wide range of PbSe nanocrystals sizes (diameters from 2.7 to 7.1 nm) and experimental parameters. Our observations indicate that native ligand-capped nanocrystal arrays are promising for optoelectronics applications wherein multiple carriers are photoinjected to interband states.

15.
J Phys Chem Lett ; 10(11): 3064-3070, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31120761

RESUMO

Electron transfer (ET) and Auger recombination (AR) processes in quantum dots (QDs) are key mechanisms for the advance of QD-based devices. However, it still remains a challenge to promote ET and suppress AR simultaneously. Here, we use in situ high-pressure ultrafast transient absorption spectroscopy to explore the impact of pressure on the ET between CdSe/ZnS and anthraquinone (AQ) and AR dissolved in cyclohexane. Remarkably, under compression, ET lifetimes are shorten, while suppression of AR lifetimes is present. The promotion of ET is attributed to the shortened distance between CdSe/ZnS and AQ induced by pressure. We rationalize that for the AR suppression, pressure may enhance the formation of an alloy layer at the core/shell interface. These findings indicate that compression is an effective approach to promote ET and suppress AR simultaneously. This study highlights a brand-new approach for modulating ET and AR and provides new routes toward QD-based applications.

16.
Sci Rep ; 9(1): 7756, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31123306

RESUMO

We use femtosecond transient absorption spectroscopy to study ultrafast electron transfer (ET) dynamics in a model donor and acceptor system using CdSe/ZnS core/shell structure quantum dots (QDs) as donors and anthraquinone (AQ) molecules as acceptors. The ET rate can be enhanced by decreasing the number of chlorine substituents in the AQ molecules because that increases the driving force, which is the energy level offset between the conduction band energy of CdSe/ZnS and the lowest upper molecular orbital potential of AQ derivatives, as confirmed by cyclic voltammetry measurements. However, the electronic coupling between the QDs and AQ derivatives, and the sum of reorganization energy of AQ molecules and solvent calculated by density functional theory are not the main reasons for the change in ET rate in three systems. Our findings provide new insights into selecting an acceptor molecule and will be useful in tuning ET processes for advanced QD-based applications.

17.
Medicine (Baltimore) ; 98(14): e14839, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30946311

RESUMO

Epstein-Barr virus (EBV)-associated lymphoepithelioma-like gastric carcinoma (LELGC) is a rare primary stomach tumor, which has overlapping imaging features with mass forming gastric carcinoma (GC). The aim of our study was to present the computed tomography (CT) findings and clinical features of EBV-associated LELGC to increase awareness of this entity.The CT findings and clinical features of 4 patients with pathologically documented EBV-associated LELGC were retrospectively analyzed.Among the 4 patients, 3 were male, and 1 was female. The medium age was 51 years old. All cases were single lesions including 1 was in the gastric cardia, 1 was in the gastric body, and 2 were in the gastric antrum. A focal thickening of the gastric wall was conducted, with a large thickness-to-length ratio. The low-density stripe of the normal gastric wall abruptly terminated at the edge of the lesion. The CT images of 4 cases showed inhomogeneous density with the radiodensity values ranging from 25 to 48 HU. In addition, an ulcer was demonstrated with an irregular base and slightly raised borders in all cases. Enhancement after injection of contrast material was heterogeneous enhancement (n = 3) or homogeneous (n = 1). After enhancement, obvious enhancement was seen in 1 case, moderate enhancement was seen in 3 cases, with the peak value of the tumor in the portal phase. No evidence of lymph node involvement and distant invasion was observed.Although LELGC is quite rare, it should be considered in differential diagnosis of early GC, advanced GC, and lymphoma. The relatively typical CT appearance, combined the age and sex of patients, can suggest the diagnosis of LELGC.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Neoplasias Gástricas/diagnóstico por imagem , Estômago/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Conscientização , Carcinoma/diagnóstico por imagem , Carcinoma/patologia , Carcinoma/virologia , Diagnóstico Diferencial , Infecções por Vírus Epstein-Barr/patologia , Feminino , Herpesvirus Humano 4/isolamento & purificação , Humanos , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/patologia , Linfoma/patologia , Linfoma/virologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estômago/patologia , Estômago/virologia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/virologia
18.
FASEB J ; 33(7): 8600-8613, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30995417

RESUMO

Delivery of multiple neurotrophic factors (NTFs), especially with time-restricted release kinetics, holds great potential for nerve repair. In this study, we utilized the tetracycline-regulatable Tet-On 3G system to control the expression of c-Jun, which is a common regulator of multiple NTFs in Schwann cells (SCs). In vitro, Tet-On/c-Jun-modified SCs showed a tightly controllable secretion of multiple NTFs, including glial cell line-derived NTF, nerve growth factor, brain-derived NTF, and artemin, by the addition or removal of doxycycline (Dox). When Tet-On/c-Jun-transduced SCs were grafted in vivo, the expression of NTFs could also be regulated by oral administration or removal of Dox. Fluoro-Gold retrograde tracing results indicated that a biphasic NTF expression scheme (Dox+3/-9, NTFs were up-regulated for 3 wk and declined to physiologic levels for another 9 wk) achieved more axonal regeneration than continuous up-regulation of NTFs (Dox+12) or no NTF induction (Dox-12). More importantly, the Dox+3/-9-group animals showed much better functional recovery than the animals in the Dox+12 and Dox-12 groups. Our findings, for the first time, demonstrated drug-controllable expression of multiple NTFs in nerve repair cells both in vitro and in vivo. These findings provide new hope for developing an optimal therapeutic alternative for nerve repair through the time-restricted release of multiple NTFs using Tet-On/c-Jun-modified SCs.-Huang, L., Xia, B., Shi, X., Gao, J., Yang, Y., Xu, F., Qi, F., Liang, C., Huang, J., Luo, Z. Time-restricted release of multiple neurotrophic factors promotes axonal regeneration and functional recovery after peripheral nerve injury.

19.
Nanoscale ; 11(7): 3123-3128, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30724309

RESUMO

Anion exchange between pre-synthesized all-inorganic nanocrystals with a perovskite structure is a promising approach to tune their chemical composition and optical properties. Herein we have reported the first study of internanocrystal anion exchange reactionsin the cesium lead halide family, including CsPbX3, Cs4PbX6 and CsX, and we found that the anion exchange dynamics is highly dependent on their crystalline phase. In stark contrast to the fast rate in CsPbX3, cesium based non-perovskite NCs display much slower halide mobility. The reaction time is increased to several hours in Cs4PbX6 and days in CsX, respectively. Furthermore, we confirm that mixing these NCs with the same halide but different structures will induce halide diffusion from Cs4PbX6 NCs and CsX NCs to CsPbX3 NCs. This feature can be explored to utilize the Cs4PbX6 NCs and CsX NCs as a halide source to improve the photoluminescence efficiency and colloidal stability of CsPbX3 NCs.

20.
J Comput Assist Tomogr ; 43(2): 187-193, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30371624

RESUMO

OBJECTIVE: This study aimed to distinguish between esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) using spectral computed tomography (CT) and to discuss the accuracy according to an optimal threshold of single and combined parameters. METHODS: In this monoinstitution study, 61 patients, 35 of whom had ESCC and 26 had EAC confirmed by surgery or esophagoscopy, were recruited from August 2016 to March 2017. Enrolled patients underwent dual-phase chest CT enhancement. The spectral CT parameters (NIC, NICD, NICratio, Zeff, Zeff-C, K40-70 keV, K80-100 keV, and K110-140 keV) were measured during arterial phase (AP) and venous phase (VP). Binary logistic regression was used to calculate combined predictive probability. Thresholds of quantitative parameters and diagnostic accuracy were calculated using receiver operating characteristic curve. RESULTS: Compared with ESCC, higher NICAP, NICVP, NICD, Zeff AP, Zeff VP, Zeff-C AP, and Zeff-C VP were observed for EAC, whereas NICratio was lower for EAC. Higher K40-70 keV, K80-100 keV, and K110-140 keV were exhibited in EAC than in ESCC. Area under the curve (AUC) of NICAP, K40-70 keV AP, and Zeff AP were 0.720, 0.730, and 0.706, respectively. The area under the curve of new combined predictive value of NICAP and λ40-0 keV AP was 0.804. The sensitivity and specificity were 77.80% and 80.60%, respectively, when the threshold of new predictive value was 0.60. CONCLUSION: The diagnostic accuracy obtained by using NICAP and K40-70 keV AP combined is better than that obtained using a single parameter in differentiation between a diagnosis of squamous cell carcinoma and adenocarcinoma.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Neoplasias Esofágicas/diagnóstico por imagem , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Junção Esofagogástrica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA