Search

To explore the correlation between the typical findings of dynamic contrast-enhanced computed tomography (DCE-CT) and tumoral angiogenesis (microvessel density [MVD] and vascular endothelial growth factor [VEGF]) in adenomas and nonadenomas such that the enhancement mechanism of DCE-CT in adrenal masses can be explained more precisely. Forty-two patients with 46 adrenal masses confirmed by surgery and pathology were included in the study; these masses included 23 adenomas, 18 nonadenomas, and 5 hyperplastic nodules. The findings of DCE-CT and angiogenesis in adrenal masses were studied. The features of DCE-CT in adenomas and nonadenomas were evaluated to determine whether the characteristics of DCE-CT in adrenal masses were closely correlated with tumoral angiogenesis. Adrenal adenomas were significantly different from nonadenomas in the time density curve and the mean percentage of enhancement washout at the 7-minute delay time in DCE-CT. The mean MVD and VEGF expression exhibited significant differences between the rapid washout group (types A and C) and the slow washout group (types B, D, and E) and between the relative washout (Washr) ≥34% and the absolute washout (Washa) ≥43% on the 7-minute enhanced CT scans (P=0.000). Adenomas were suggested when adrenal masses presented as types A and C, and/or the Washr ≥34%, and/or the Washa ≥43%, and the opposite was suggested for nonadenomas. These results showed a close correlation between the characteristics of DCE-CT and both MVD and VEGF expression in adrenal masses. There was also a significant difference in MVD and VEGF expression between adenomas and nonadenomas. In conclusion, MVD and VEGF expression are two important pathological factors that play important roles in the characterization of DCE-CT in adrenal masses because they cause different time density curve types, the Washr and the Washa for adrenal adenomas and nonadenomas.

This study was performed to evaluate the findings including the time density curve (TD curve), the relative percentage of enhancement washout (Washr) and the absolute percentage of enhancement washout (Washa) at dynamic contrast-enhanced computed tomography (DCE-CT) in 70 patients with 79 adrenal masses (including 44 adenomas and 35 nonadenomas) confirmed histopathologically and/or clinically. The results demonstrated that the TD curves of adrenal masses were classified into 5 types, and the type distribution of the TD curves was significantly different between adenomas and nonadenomas. Types A and C were characteristic of adenomas, whereas types B, D and E were features of nonadenomas. The sensitivity, specificity and accuracy for the diagnosis of adenoma based on the TD curves were 93%, 80% and 87%, respectively. Furthermore, when myelolipomas were excluded, the specificity and accuracy for adenoma were 90% and 92%, respectively. The Washr and the Washa values for the adenomas were higher than those for the nonadenomas. The diagnostic efficiency for adenoma was highest at 7-min delay time at DCE-CT; Washr was more efficient than Washa. Washr ≥34% and Washa ≥43% were both suggestive of adenomas and, on the contrary, suspicious of nonadenomas. The sensitivity, specificity and accuracy for the diagnosis of adenoma were 84%, 77% and 81%, respectively. When myelolipomas were precluded, the diagnostic specificity and accuracy were 87% and 85%, respectively. Therefore, DCE-CT aids in characterization of adrenal tumors, especially for lipid-poor adenomas which can be correctly categorized on the basis of TD curve combined with the percentage of enhancement washout.

Through Silicon Via(TSV), as a key interconnection technology in 3D integrated circuits, is used to connect input and output of chips in different layers. When multiple TSVs with alternating current close to each other, will produce the proximity effect, which increases the resistance of the TSV, thus affecting the transmission performance of TSV. Therefore, a method of calculating AC resistance of TSV array based on barycentric interpolation is presented. On the basis of triangulation of TSV cross section and determining the current intensity of vertices, the AC power consumption of TSV is calculated by interpolation method, the AC to DC resistance ratio of TSV is calculated by the AC to DC power ratio, and then the AC resistance value of TSV under the influence of proximity effect is obtained. This method can realize the calculation of AC resistance of TSV array in arbitrary scale and arrangement, and it will provide guidance and verification for the design of transmission structure in three dimensional integrated circuits. Finally, the numerical results of this method are compared with the results of commercial solver ANSYS Q3D. The experimental results show that the proposed method acquires better performance.

Switchback experiments, where a firm sequentially exposes an experimental unit to random treatments, are among the most prevalent designs used in the technology sector, with applications ranging from ride-hailing platforms to online marketplaces. Although practitioners have widely adopted this technique, the derivation of the optimal design has been elusive, hindering practitioners from drawing valid causal conclusions with enough statistical power. We address this limitation by deriving the optimal design of switchback experiments under a range of different assumptions on the order of the carryover effect—the length of time a treatment persists in impacting the outcome. We cast the optimal experimental design problem as a minimax discrete optimization problem, identify the worst-case adversarial strategy, establish structural results, and solve the reduced problem via a continuous relaxation. For switchback experiments conducted under the optimal design, we provide two approaches for performing inference. The first provides exact randomization-based p-values, and the second uses a new finite population central limit theorem to conduct conservative hypothesis tests and build confidence intervals. We further provide theoretical results when the order of the carryover effect is misspecified and provide a data-driven procedure to identify the order of the carryover effect. We conduct extensive simulations to study the numerical performance and empirical properties of our results and conclude with practical suggestions. This paper was accepted by George Shanthikumar, big data analytics. Funding: The authors thank the Massachusetts Institute of Technology (MIT)-IBM partnership in Artificial Intelligence and the MIT Data Science Laboratory for support. Supplemental Material: Data and the online appendix are available at https://doi.org/10.1287/mnsc.2022.4583. [ABSTRACT FROM AUTHOR]

This work is motivated by our collaboration with a large consumer packaged goods (CPG) company. We have found that whereas the company appreciates the advantages of dynamic pricing, they deem it operationally much easier to plan out a static price calendar in advance. We investigate the efficacy of static control policies for revenue management problems whose optimal solution is inherently dynamic. In these problems, a firm has limited inventory to sell over a finite time horizon, over which heterogeneous customers stochastically arrive. We consider both pricing and assortment controls, and derive simple static policies in the form of a price calendar or a planned sequence of assortments, respectively. In the assortment planning problem, we also differentiate between the static vs. dynamic substitution models of customer demand. We show that our policies are within 1-1/e (approximately 0.63) of the optimum under stationary demand, and 1/2 of the optimum under nonstationary demand, with both guarantees approaching 1 if the starting inventories are large. We adapt the technique of prophet inequalities from optimal stopping theory to pricing and assortment problems, and our results are relative to the linear programming relaxation. Under the special case of stationary demand single-item pricing, our results improve the understanding of irregular and discrete demand curves, by showing that a static calendar can be (1-1/e)-approximate if the prices are sorted high-to-low. Finally, we demonstrate on both data from the CPG company and synthetic data from the literature that our simple price and assortment calendars are effective. This paper was accepted by Hamid Nazerzadeh, big data analytics. [ABSTRACT FROM AUTHOR]

To understand the influence of storage period on the quality of light-flavor Daqu, physicochemical and biochemical indices, as well as microbial communities of Daqu were analyzed by traditional and metagenomics methods. The results suggest that the moisture content of the Daqu samples are essentially invariant during the storage period; the acidity ascended slowly during the first 3 months, then descended; the saccharifying power of some samples began to decrease during the first 3 months. The diversity of the bacterial and fungal communities of some of the Daqu samples was found to decline to a minimum after storage for 3 months. On the basis of the variations in primary indices of the Daqu samples, it was deemed acceptable to store samples for 3 months before use for light-flavor Daqu. This is the first report of Daqu quality being estimated during storage by physicochemical, biochemical, and microbial indices, and it provides a theoretical foundation for the quality evaluation of Daqu during storage and use. [ABSTRACT FROM AUTHOR]

Background/Aims: It is crucial to detect the composition of the thrombus in isolated brainstem infarction with large artery occlusion. The aim of this study was to explore the susceptibility vessel sign (SVS) whose composition is mainly deoxidized red cells in patients with isolated brainstem infarction and posterior circulation large artery occlusion. Methods: This was a single-center retrospective study. All patients with posterior circulation large artery occlusion from January 2003 to September 2013 were included. We identified 213 patients who had posterior circulation large artery occlusion, and 81 patients met the imaging eligibility criteria. Among the 81 patients, 21 had isolated brainstem infarction. Results: Among the 21 patients, 7 (33%) had SVS and 2 (10%) had pseudo-SVS (calcified vessels without thrombosis). In the 7 patients with SVS, we found atrial fibrillation in 2 patients, dissection in 3 patients and large artery atherosclerotic disease (LAAD) in 2 patients. There were SVS in 100% (2/2) of patients with atrial fibrillation, 50% (3/6) of patients with dissection, and 20% (2/10) of patients with LAAD. Conclusions: SVS reflects pathology of deoxidized red cells composition in patients with isolated brainstem infarction. This finding may be useful to explore the different stroke mechanisms and therapy strategies. [ABSTRACT FROM AUTHOR]

In order to find a suitable method for detecting the microbe index of Daqu for Chinese liquor brewing, during the regular production of Daqu, the phospholipid fatty acid (PLFA) profiles of Daqu for light-fragrant Chinese liquor were investigated. Three types of Daqu clearly showed different features. The PLFA 18:3 w 6c (3, 6, 9), as one of the biomarkers for fungi, was the highest in the Houhuoqu samples, the lowest in the Hongxinqu samples and moderate with fluctuations in the Qingchaqu samples. The PLFA 18:1 w 9c, another biomarker for fungi, was only detected in the Hongxinqu samples with a steady content. The ratio of the fungi to bacteria of Hongxinqu was 11:20, which was significantly higher than in the Qingchaqu and the Houhuoqu samples. Principal component analysis found that most of the variations in the PLFA patterns were due to the different Daqu types. Variances analysis found that some PLFAs had the potential to be used as representative biomarkers for each type of Daqu. Copyright © 2016 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

We report a facile approach to fabricating low-generation poly(amidoamine) (PAMAM) dendrimer-stabilized gold nanoparticles (Au DSNPs) functionalized with folic acid (FA) for in vitro and in vivo targeted computed tomography (CT) imaging of cancer cells. In this study, amine-terminated generation 2 PAMAM dendrimers were employed as stabilizers to form Au DSNPs without additional reducing agents. The formed Au DSNPs with an Au core size of 5.5 nm were covalently modified with the targeting ligand FA, followed by acetylation of the remaining dendrimer terminal amines to endow the particles with targeting specificity and improved biocompatibility. Our characterization data show that the formed FA-modified Au DSNPs are stable at different pH values (5-8) and temperatures (4-50 °C), as well as in different aqueous media. MTT assay data along with cell morphology observations reveal that the FA-modified Au DSNPs are noncytotoxic in the particle concentration range of 0-3000 n M. X-ray attenuation coefficient measurements show that the CT value of FA-modified Au DSNPs is much higher than that of Omnipaque (a clinically used CT contrast agent) at the same concentration of the radiodense elements (Au or iodine). Importantly, the FA-modified Au DSNPs are able to specifically target a model cancer cell line (KB cells, a human epithelial carcinoma cell line) over-expressing FA receptors and they enable targeted CT imaging of the cancer cells in vitro and the xenografted tumor model in vivo after intravenous administration of the particles. With the simple synthesis approach, easy modification, good cytocompatibility, and high X-ray attenuation coefficient, the FA-modified low-generation Au DSNPs could be used as promising contrast agents for targeted CT imaging of different tumors over-expressing FA receptors. [ABSTRACT FROM AUTHOR]

We report a facile approach to fabricating dendrimer-stabilized gold–silver alloy nanoparticles (Au–Ag alloy DSNPs) for targeted in vitro computed tomography (CT) imaging of cancer cells. In this study, folic acid (FA)-modified amine-terminated generation 5 poly(amidoamine) dendrimers (G5·NH2–FA) were used as stabilizers to prepare Au–Ag alloy DSNPs by simultaneously reducing both gold and silver salts, followed by acetylation of the dendrimer terminal amines. The formed Au–Ag alloy DSNPs were characterized via different techniques. We show that the formed Au–Ag alloy DSNPs are spherical in shape with a relatively narrow size distribution, have good water solubility and colloidal stability, and display higher X-ray attenuation intensity than the iodine-based contrast agent of Omnipaque at the same molar concentration of the active element (i.e., Au plus Ag, or iodine). Cytotoxicity assay results show that the Au–Ag alloy DSNPs are cytocompatible in a given concentration range. Importantly, the formed Au–Ag alloy DSNPs are able to be specifically taken up by cancer cells overexpressing FA receptors and enable targeted CT imaging of the cancer cells. Given the unique structural characteristics of dendrimers and the facile synthesis of DSNPs, the developed Au–Ag alloy DSNPs may be used for various biomedical applications in sensing, diagnosis, and therapeutics. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) and chlorinated paraffins (CPs) are well-knownpersistent organic pollutants (POPs) in the environment, which are toxic, bio-accumulativeand suspected to be carcinogenic. Short-chain (SCCPs) and medium-chain CPs (MCCPs) aremost commonly seen in soils and water and originate from typical industrial synthetics. Inthis work, the concentrations of 16 PAHs, prior controlled by the Environmental ProtectionAgency (EPA) of the US, 24 SCCPs and 24 MCCPs in the soils of six agricultural samplingfields in the suburbs of Shanghai were monitored. The results were as follows: Thetotal concentrations of the 16 PAHs are in a range of 161.69-5141.08 ng g−1. Theagricultural soils nearby industrial parks are often seriously polluted by PAHs,while those far away from the industrial areas in Qingpu District in the westernsuburb of Shanghai are in the lowest content of PAHs. The rate of fluoranthene(Flu) in the PAHs in the soils is the highest, 20.3% on average, followed by pyrene(Pyr) and chrysene (Chr), 16.3% and 12.8% on average respectively. The PAHsin the soils are dominated by high-ring homologues (above three rings), whichmakes up 87.5% on average. The rate of 4-ring homologues in the PAHs is thehighest, 59.1% on average. This suggests that the PAHs in the agricultural soils inShanghai were mainly derived from coal combustion. The concentrations of CPs in thesoils are in a range of 6.99 - 499.27 ng/g. SCCPs, in a range of 3.18 - 101 ng/g,are dominantly composed of C12−13 homologues, with the chlorination degreeof 63.1% on average. Especially, in the soils of Baoshan and Qingpu Districts,Shanghai, the C13 homologue makes up over 50% of the total SCCPs. MCCPs, in arange of 1.68 - 396 ng/g, are dominantly composed of C14−15 homologues, withthe chlorination degree of 52.3% on average. The concentrations of MCCPs aremostly higher than those of SCCPs in the soils. Compared with the soils of theother areas in the world, however, the concentrations of SCCPs and MCCPs in theagricultural soils in Shanghai are at the medium level. According to the ratios ofhomologues, CPs in the soils in Shanghai was mostly caused by the discharge ofindustrial solid wastes, sewage sludge application and/or wastewater irrigation.Generally, the degree of CPs contamination in the soils in Shanghai is lighter than thatof PAHs. Moreover, the increase of PAHs in the soils is not correlated with theelevation of CPs simultaneously, suggesting that PAHs and CPs in the soils havedifferent paths and sources of pollution. This work was supported by the Science andTechnology Commission of Shanghai Municipality (Grant no. 17DZ1202300). [ABSTRACT FROM AUTHOR]

Abstract: We report the dendrimer-mediated synthesis and shape evolution of gold–silver alloy nanoparticles (Au–Ag alloy NPs) with different metal compositions. In this study, amine-terminated generation 5 poly(amidoamine) dendrimers were used as stabilizers to prepare Au–Ag alloy NPs with different gold atom/silver atom/dendrimer molar ratios without the assistance of additional reducing agents. Following a one-step acetylation reaction to transform the dendrimer terminal amines to acetyl groups, a series of Au–Ag alloy NPs with surface acetyl groups were formed. The alloy NPs before and after acetylation reaction were characterized using 1H NMR, UV–vis spectrometry, transmission electron microscopy, inductively coupled plasma-optical emission spectroscopy, and X-ray absorption coefficient measurements. We showed that the optical property, the size, and the morphology of the bimetallic NPs were greatly affected by the metal composition and their surface modification. At the constant total metal atom/dendrimer molar ratio, the alloy NPs experienced a shape evolution from spherical particles and polyhedrons to curved nanowires with the Au content. Acetylation of the dendrimer terminal amines seemed to thicken the nanowires. The formed Au–Ag alloy NPs were stable at different pH (pH 5–8) and temperature (4–50°C) conditions. X-ray absorption coefficient measurements showed that the attenuation intensity of the alloy NPs was dependent on both the metal composition and surface functional groups. At a given metal composition, the X-ray attenuation intensity of the binary NPs was enhanced after acetylation. The formed metal alloy NPs with tunable size and shape prepared using the dendrimer stabilizers may be used in a range of applications in catalysis, sensing, and biomedical sciences. [Copyright &y& Elsevier]

In this work, we investigated PEGylated black kidney bean protein isolates (BKBPI) by PEG succinimidyl carbonate (PEG-SC), PEG succinimidyl succinate (PEG-SS) and PEG succinimidyl propionate (PEG-SPA) conjugation. The functional properties, thermodynamic stability, in vitro digestion stability, and hemagglutination activity of the modified products were evaluated. The degree of PEGylation was measured, and FTIR analysis revealed that protein-PEG conjugations were formed, and that no obvious changes in water- and fat-holding capacities were observed. The solubility, emulsifying property, and foaming property were all improved through the modification, while, higher thermodynamic stability was achieved with the increase in Td values and reduction of ΔH. The PEGylated proteins were found to be more resistant to in vitro digestion, and the hemagglutination activity was significantly ( P <  0.05) decreased, indicating the higher safety of the protein isolate. The results showed that the functional properties, thermodynamic stability, and biological safety of BKBPI were improved by PEGylation, which could serve to increase the applications for this protein. [ABSTRACT FROM AUTHOR]

Abstract: Based on density functional theory, the spin frustration and the spin–lattice coupling in hexagonal HoMnO3 are investigated. By comparing the different lattice geometry of antiferromagnetic, noncollinear Γ 1 and Γ 4 structure, we show that the ionic position in the unit cell, the bond length, the distribution of electronic structures have a significant correlation with frustrated magnetic structures. The strong orbital hybridizations of Ho 5d z 2 -O(3,4) 2p z and Mn 3 states modify the strength of the bonds and hold the key to spin–lattice coupling and lattice distortion. All these provide theoretical support for the explanation of the magnetoelectric phenomenon in HoMnO3. [Copyright &y& Elsevier]

SiO 2 nanowires have been successfully synthesized on the surface of the silicon substrate via a thermal evaporation method using SnO 2 powders as the catalysts. The final synthesized product was systematically studied by X-ray powder diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM), and electron energy dispersive X-ray (EDX), UV-Visible absorption and photoluminescence (PL) spectroscopy. The results reveal that in the reaction and growth process, the real catalytic effect is Sn and SnO x , and the growth of SiO 2 nanowire is most likely controlled by VLS mechanism. The PL spectral results indicate the obtained products have a stable yellow-green emission range. The products have improved performance and can be used in optoelectronic semiconductor devices. • SiO 2 nanowires are successfully prepared by thermal evaporation using SnO 2 as catalyst. • The growth mechanism of SiO 2 nanowires follows the VLS mechanism. • Due to the influence of saturated vapor pressure, the morphology and structure of samples are different in different temperature regions. • The SiO 2 nanowires display yellow-green emission which is probably ascribed to the luminescence center model of the doped SiO 2. [ABSTRACT FROM AUTHOR]

Alberta Stroke Program Early Computed Tomography (CT) score (ASPECTS) has been applied to CT perfusion (CTP) with good interrater agreement to predict early ischemic stroke, and it can be useful in decision making in acute ischemic stroke. The aim of the present study was to assess the predictive value of CTP ASPECTS of hemorrhagic transformation (HT) in acute cardioembolic stroke. This is a single-enter, retrospective study. All patients hospitalized with acute cardioembolic stroke from January 2008 to September 2013 were included. ASPECTS of baseline non-contrast CT, CTP maps of cerebral blood volume (CBV), cerebral blood flow, and mean transit time were collected from 52 consecutive patients with less than 12-h anterior circulation ischemic stroke. MRI scan was performed within 72 h of symptom onset after index stroke including T2*-weighted gradient echo to identify HT. For bleeding risk assessment, CTP and diffusion-weighted imaging ASPECTS were categorized into 0-7 or 8-10. Baseline characteristics, ASPCETS scores and HT were compared. Eighteen (34.6%) patients had HT and four (7.7%) developed symptomatic HT. On univariate analysis, the proportion of patients with CBV-ASPECTS 0-7 was significantly higher in HT patients as compared to patients without HT (44 versus 9%, P  = 0.005). CBV ASPECTS 0-7 remained independent prognostic factors for HT after adjustment for clinical baseline variables. CBV ASPECTS could be of value to predict HT risk after acute cardioembolic stroke and may be a quick risk assessment approach before reperfusion therapy.

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death worldwide. Tumour progression and development in CRC is a multi-step process involving a large number of genetic and epigenetic alterations. Previous studies indicated that abnormally expressed microRNAs play critical roles in CRC through regulation of oncogenic and tumour-suppressor genes. Hence, determination of the function of microRNAs may provide novel therapeutic targets for CRC diagnosis and treatments. MicroRNA‑337 (miR‑337) has been reported to be downregulated in several cancer types. However, the expression, function and underlying mechanisms of miR‑337 in CRC have not been clearly elucidated. In this study, miR‑337 was significantly decreased in CRC tissues and cell lines. Low miR‑337 expression level was correlated with lymph node metastasis, distant metastasis and TNM stage of CRC patients. In addition, upregulation of miR‑337 suppressed cell proliferation and invasion and promoted apoptosis in CRC. Based on bioinformatics analysis, we assumed that Kirsten rat sarcoma viral oncogene homolog (KRAS) was directly modulated by miR‑337 in CRC. Luciferase reporter assay demonstrated the direct interaction between miR‑337 and 3'‑UTR of KRAS mRNA. Furthermore, reverse transcription-quantitative polymerase chain reaction and western blot analysis indicated that miR‑337 could negatively regulate endogenous KRAS expression in CRC cells at both mRNA and protein levels. Moreover, KRAS was highly expressed in CRC tissues and inversely correlated with miR‑337 expression in CRC tissues. KRAS knockdown recapitulates effects similar to those induced by miR‑337 overexpression in CRC cells, whereas KRAS overexpression partially restored the tumour suppressive effects of miR‑337. Besides, ectopic expression of miR‑337 inactivates the AKT and ERK signalling pathways in CRC. These results suggested that miR‑337 may act as a tumour suppressor during the process of CRC malignant transformation by interacting with KRAS.

This study was performed to evaluate the findings including the time density curve (TD curve), the relative percentage of enhancement washout (Washr) and the absolute percentage of enhancement washout (Washa) at dynamic contrast-enhanced computed tomography (DCE-CT) in 70 patients with 79 adrenal masses (including 44 adenomas and 35 nonadenomas) confirmed histopathologically and/or clinically. The results demonstrated that the TD curves of adrenal masses were classified into 5 types, and the type distribution of the TD curves was significantly different between adenomas and nonadenomas. Types A and C were characteristic of adenomas, whereas types B, D and E were features of nonadenomas. The sensitivity, specificity and accuracy for the diagnosis of adenoma based on the TD curves were 93%, 80% and 87%, respectively. Furthermore, when myelolipomas were excluded, the specificity and accuracy for adenoma were 90% and 92%, respectively. The Washr and the Washa values for the adenomas were higher than those for the nonadenomas. The diagnostic efficiency for adenoma was highest at 7-min delay time at DCE-CT; Washr was more efficient than Washa. Washr ≥34% and Washa ≥43% were both suggestive of adenomas and, on the contrary, suspicious of nonadenomas. The sensitivity, specificity and accuracy for the diagnosis of adenoma were 84%, 77% and 81%, respectively. When myelolipomas were precluded, the diagnostic specificity and accuracy were 87% and 85%, respectively. Therefore, DCE-CT aids in characterization of adrenal tumors, especially for lipid-poor adenomas which can be correctly categorized on the basis of TD curve combined with the percentage of enhancement washout., Competing Interests: The authors report no conflicts of interest in this work.

To explore the correlation between the typical findings of dynamic contrast-enhanced computed tomography (DCE-CT) and tumoral angiogenesis (microvessel density [MVD] and vascular endothelial growth factor [VEGF]) in adenomas and nonadenomas such that the enhancement mechanism of DCE-CT in adrenal masses can be explained more precisely. Forty-two patients with 46 adrenal masses confirmed by surgery and pathology were included in the study; these masses included 23 adenomas, 18 nonadenomas, and 5 hyperplastic nodules. The findings of DCE-CT and angiogenesis in adrenal masses were studied. The features of DCE-CT in adenomas and nonadenomas were evaluated to determine whether the characteristics of DCE-CT in adrenal masses were closely correlated with tumoral angiogenesis. Adrenal adenomas were significantly different from nonadenomas in the time density curve and the mean percentage of enhancement washout at the 7-minute delay time in DCE-CT. The mean MVD and VEGF expression exhibited significant differences between the rapid washout group (types A and C) and the slow washout group (types B, D, and E) and between the relative washout (Washr) ≥34% and the absolute washout (Washa) ≥43% on the 7-minute enhanced CT scans (P=0.000). Adenomas were suggested when adrenal masses presented as types A and C, and/or the Washr ≥34%, and/or the Washa ≥43%, and the opposite was suggested for nonadenomas. These results showed a close correlation between the characteristics of DCE-CT and both MVD and VEGF expression in adrenal masses. There was also a significant difference in MVD and VEGF expression between adenomas and nonadenomas. In conclusion, MVD and VEGF expression are two important pathological factors that play important roles in the characterization of DCE-CT in adrenal masses because they cause different time density curve types, the Washr and the Washa for adrenal adenomas and nonadenomas.

Development of novel nanomaterial-based contrast agents for targeted computed tomography (CT) imaging of tumors still remains a great challenge. Here we describe a novel approach to fabricating lactobionic acid (LA)-modified dendrimer-entrapped gold nanoparticles (LA-Au DENPs) for in vitro and in vivo targeted CT imaging of human hepatocellular carcinoma. In this study, amine-terminated poly(amidoamine) dendrimers of generation 5 pre-modified with fluorescein isothiocyanate and poly(ethylene glycol)-linked LA were employed as templates to form Au nanoparticles. The remaining dendrimer terminal amines were subjected to an acetylation reaction to form LA-Au DENPs. The prepared LA-Au DENPs were characterized via different methods. Our results reveal that the multifunctional Au DENPs with a Au core size of 2.7 nm have good stability under different pH (5-8) and temperature (4-50 °C) conditions and in different aqueous media, and are noncytotoxic to normal cells but cytotoxic to the targeted hepatocarcinoma cells in the given concentration range. In vitro flow cytometry data show that the LA-Au DENPs can be specifically uptaken by a model hepatocarcinoma cell line overexpressing asialoglycoprotein receptors through an active receptor-mediated targeting pathway. Importantly, the LA-Au DENPs can be used as a highly effective nanoprobe for specific CT imaging of hepatocarcinoma cells in vitro and the xenoplanted tumor model in vivo. The developed LA-Au DENPs with X-ray attenuation property greater than clinically employed iodine-based CT contrast agents hold a great promise to be used as a nanoprobe for targeted CT imaging of human hepatocellular carcinoma.

Dendrimer-entrapped gold nanoparticles (Au DENPs) can be formed using low-generation dendrimers pre-modified by polyethylene glycol (PEG). The formed PEGylated Au DENPs with desirable stability, cytocompatibility, and X-ray attenuation properties enable efficient computed tomography imaging of the heart and tumor model of mice.

We describe a facile approach to synthesizing acetylated dendrimer-entrapped gold nanoparticles (Au DENPs) with enhanced Au loading in the dendrimer interior. In this study, amine-terminated generation 5 poly(amidoamine) (PAMAM) dendrimers (G5.NH 2 ) were used as templates to form Au DENPs via a stepwise Au salt complexation/reduction approach, followed by acetylation of the dendrimer terminal amines. The formed Au DENPs before and after acetylation were characterized with different techniques. We show that the stepwise complexation/reduction of HAuCl 4 is able to significantly improve the loading amount of Au within the dendrimer interior. UV-Vis spectroscopy reveals that the intensity of the surface plasmon resonance (SPR) band increases with the Au loading, confirming the stepwise loading synthesis of Au DENPs. TEM images show that the synthesized Au DENPs have a quite uniform size distribution with sizes tunable in the range of 2-4 nm depending on the Au loading. The formed acetylated Au DENPs with enhanced Au loading are very stable under different pH and temperature conditions. Importantly, computed tomography (CT) imaging experiments reveal that the formed acetylated Au DENPs have higher attenuation intensity than a clinically used iodinated contrast agent, Omnipaque, at the same molar concentration of active elements (Au or iodine), and enable significantly enhanced CT imaging of rat heart in vivo. The acetylated Au DENPs with enhanced Au loading formed via the facile stepwise approach may be used as contrast agents for highly sensitive CT imaging applications.

We report a facile approach to fabricating low-generation poly(amidoamine) (PAMAM) dendrimer-stabilized gold nanoparticles (Au DSNPs) functionalized with folic acid (FA) for in vitro and in vivo targeted computed tomography (CT) imaging of cancer cells. In this study, amine-terminated generation 2 PAMAM dendrimers were employed as stabilizers to form Au DSNPs without additional reducing agents. The formed Au DSNPs with an Au core size of 5.5 nm were covalently modified with the targeting ligand FA, followed by acetylation of the remaining dendrimer terminal amines to endow the particles with targeting specificity and improved biocompatibility. Our characterization data show that the formed FA-modified Au DSNPs are stable at different pH values (5-8) and temperatures (4-50 °C), as well as in different aqueous media. MTT assay data along with cell morphology observations reveal that the FA-modified Au DSNPs are noncytotoxic in the particle concentration range of 0-3000 nM. X-ray attenuation coefficient measurements show that the CT value of FA-modified Au DSNPs is much higher than that of Omnipaque (a clinically used CT contrast agent) at the same concentration of the radiodense elements (Au or iodine). Importantly, the FA-modified Au DSNPs are able to specifically target a model cancer cell line (KB cells, a human epithelial carcinoma cell line) over-expressing FA receptors and they enable targeted CT imaging of the cancer cells in vitro and the xenografted tumor model in vivo after intravenous administration of the particles. With the simple synthesis approach, easy modification, good cytocompatibility, and high X-ray attenuation coefficient, the FA-modified low-generation Au DSNPs could be used as promising contrast agents for targeted CT imaging of different tumors over-expressing FA receptors., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)