Differentiated Thyroid Cancer after Thyroidectomy.

The widespread use of neck US and other imaging modalities has contributed to a phenomenon of increased detection of differentiated thyroid cancer (DTC). Most of these cancers remain indolent, without requiring surgical intervention. Nonetheless, a subset of patients who require surgical treatment experience subsequent disease recurrence. This most commonly occurs in the cervical lymph nodes and thyroid bed, followed by distant metastasis to the lungs and bones. Because imaging is an integral part of postoperative surveillance, radiologists play a central role in the detection of recurrent tumors and in guiding treatment in these patients. US is the primary imaging modality used for postoperative evaluation. Other modalities such as CT, MRI, radioactive iodine imaging, and PET/CT aid in the accurate diagnosis and characterization of recurrent disease. Therefore, radiologists must have a thorough understanding of the utility of these imaging techniques and the imaging characteristics of recurrent DTC when interpreting these multimodality studies. The interpretation of imaging findings should also be correlated with the clinical status of patients and their biochemical markers to minimize interpretative errors. The authors present a broad overview of the postoperative evaluation of DTC, including its initial primary management, staging, and prognostication; clinical risk stratification for recurrent disease; postoperative surveillance with imaging and evaluation of biochemical markers; and management of recurrent DTC. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Comparison of China's and the European Union's Approaches to Antimicrobial Stewardship in the Pork Industry.

Antimicrobial resistance (AMR) is a recognized global public health concern. Although the link between antimicrobial usage in food animals and AMR in humans is established, the detailed interactions are unclear. Antimicrobial stewardship (AMS) in livestock was first implemented in Europe with Sweden as the pioneer in 1986. Despite this head start, AMR is still an ongoing challenge for Europe. The European Union (EU) is an established agriculture producer, the second largest pork producer globally, and one of the largest markets for organic food. China is the global leader in both production and consumption of pork. China's rise in prosperity has led to an increase in its pork demand. Chinese producers commonly use antimicrobials during production for disease treatment and prevention to meet this increased demand. China's rising prosperity together with recent publicized food safety scandals, disease outbreaks in domestic livestock products, and increased AMR awareness have resulted in an increased willingness to pay and demand for organic food by Chinese consumers. Responding to the growing concerns of AMR by consumers and the World Health Organization (WHO), the Chinese government introduced a national pilot program in 2016 to reduce unnecessary antimicrobial use. Compared with China, the EU is a different entity as it is a political union comprising diverse countries and although it may have more experience in AMS, both entities face similar issues with AMR and increasing demand for organic food. Increased interest in organic food has arisen due to concerns about AMR, food safety, outbreaks of bacterial food contamination, and animal welfare. This article aims to compare the different AMS strategies employed by each entity, China and the EU, and how the increased demand for organic produce globally also influences the effort to reduce antimicrobial use in these entities' pork industries.

Lateral Condyle Fracture of the Humerus Among Children Attending a Pediatric Emergency Department: A 10-Year Single-Center Experience.

BACKGROUND: The lateral humeral condyle fractures in children accounts for one fifth of all elbow fractures. These fractures have a propensity to displace because of the pull of the extensor muscles on the condyle. OBJECTIVES: The aim of this study was to examine the epidemiology, injury patterns, complications, and predictors for conservative/surgical management in patients with lateral condyle humeral fractures between 0 and 18 years of age. METHODS: This was a single-center retrospective study conducted between January 2006 and December 2016. RESULTS: There were 268 patients identified with lateral condyle elbow fracture. Majority of the patients (81.4%) with lateral condyle humeral fractures presented with either undisplaced or minimally displaced (<2 mm) fractures. The initial management in majority (90.7%) of the patients was conservative. Of the patients, 26.8% had secondary displacement at follow-up. The overall proportion of patients who required surgical intervention was 36.2%. Varus deformity of elbow (2.2%) and malunion (0.4%) were the complications noticed on long-term follow-up. Increased age and undisplaced fracture were statistically significant positive predictors for conservative management. The presence of concurrent elbow injuries and type of fracture (displaced >2 mm) were statistically significant positive predictors for surgical management. CONCLUSIONS: Our study demonstrated that majority of the patients with lateral condyle humeral fractures had presented with either undisplaced or minimally displaced (<2 mm) fractures. The positive predictors for conservative management of fractures were increased age and undisplaced fracture. The positive predictors for surgical management of lateral condyle humerus fractures were concurrent injuries in elbow and type of fracture (displaced >2 mm). Physician vigilance to the possibility of additional migration of lateral condyle fractures initially managed conservatively, and the need for subsequent surgical stabilization plays an important role in the management of these fractures.

Synthesis of Light-Responsive Pyrene-Based Polymer Nanoparticles via Polymerization-Induced Self-Assembly.

The use of an in situ, one-pot polymerization-induced self-assembly method to synthesize light-responsive pyrene-containing nanoparticles is reported. The strategy is based on the chain extension of a hydrophilic macromolecular chain transfer agent, poly(oligo(ethylene glycol) methyl ether methacrylate), using a light-responsive monomer, 1-pyrenemethyl methacrylate (PyMA), via a reversible addition-fragmentation chain transfer dispersion polymerization; yielding nanoparticles of various morphologies (spherical micelles and worm-like micelles). In this process, addition of comonomers, such as butyl methacrylate (BuMA) or methyl methacrylate (MMA), are required to obtain high PyMA monomer conversion (>80% in 24 h). The addition of comonomers reduces the π-π stacking of the pyrene moieties, which facilitates the diffusion of monomers in the nanoparticle core. The addition of BuMA (as a comonomer) offers P(PyMA-co-BuMA) core-forming chains with high mobility that enables the reorganization of chains and then the evolution of morphology to form vesicles. In contrast, when MMA comonomer is used, kinetically trapped spheres are obtained; this is due to the low mobility of the core-forming chains inhibiting in situ morphological evolution. Finally, the UV-light-induced dissociation of these light-responsive nanoparticles due to the gradual cleavage of the pyrene moieties and the subsequent hydrophobic-to-hydrophilic transitions of the core-forming blocks is demonstrated.

High peak and high average radiofrequency power transmit/receive switch for thermal magnetic resonance.

PURPOSE: To study the role of temperature in biological systems, diagnostic contrasts and thermal therapies, RF pulses for MR spin excitation can be deliberately used to apply a thermal stimulus. This application requires dedicated transmit/receive (Tx/Rx) switches that support high peak powers for MRI and high average powers for RF heating. To meet this goal, we propose a high-performance Tx/Rx switch based on positive-intrinsic-negative diodes and quarter-wavelength (λ/4) stubs. METHODS: The λ/4 stubs in the proposed Tx/Rx switch design route the transmitted RF signal directly to the RF coil/antenna without passing through any electronic components (e.g., positive-intrinsic-negative diodes). Bench measurements, MRI, MR thermometry, and RF heating experiments were performed at f = 297 MHz (B0 = 7 T) to examine the characteristics and applicability of the switch. RESULTS: The proposed design provided an isolation of -35.7dB/-41.5dB during transmission/reception. The insertion loss was -0.41dB/-0.27dB during transmission/reception. The switch supports high peak (3.9 kW) and high average (120 W) RF powers for MRI and RF heating at f = 297 MHz. High-resolution MRI of the wrist yielded image quality competitive with that obtained with a conventional Tx/Rx switch. Radiofrequency heating in phantom monitored by MR thermometry demonstrated the switch applicability for thermal modulation. Upon these findings, thermally activated release of a model drug attached to thermoresponsive polymers was demonstrated. CONCLUSION: The high-power Tx/Rx switch enables thermal MR applications at 7 T, contributing to the study of the role of temperature in biological systems and diseases. All design files of the switch will be made available open source at www.opensourceimaging.org.

Ferrous ion as a reducing agent in the generation of antibiofilm nitric oxide from a copper-based catalytic system.

The work found that the electron-donating properties of ferrous ions (Fe2+) can be used for the conversion of nitrite (NO2-) into the biofilm-dispersing signal nitric oxide (NO) by a copper(II) complex (CuDTTCT) catalyst, a potentially applicable biofilm control technology for the water industries. The availability of Fe2+ varied depending on the characteristics of the aqueous systems (phosphate- and carbonate-containing nitrifying bacteria growth medium, NBGM and phosphate buffered saline, PBS at pH 6 to 8, to simulate conditions typically present in the water industries) and was found to affect the production of NO from nitrite by CuDTTCT (casted into PVC). Greater amounts of NO were generated from the CuDTTCT-nitrite-Fe2+ systems in PBS compared to those in NBGM, which was associated with the reduced extent of Fe2+-to-Fe3+ autoxidation by the iron-precipitating moieties phosphates and carbonate in the former system. Further, acidic conditions at pH 6.0 were found to favor NO production from the catalytic system in both PBS and NBGM compared to neutral or basic pH (pH 7.0 or 8.0). Lower pH was shown to stabilize Fe2+ and reduce its autoxidation to Fe3+. These findings will be beneficial for the potential implementation of the NO-generating catalytic technology and indeed, a 'non-killing' biofilm dispersal activity of CuDTTCT-nitrite-Fe2+ was observed on nitrifying bacteria biofilms in PBS at pH 6.

Exploiting the Versatility of Polydopamine-Coated Nanoparticles to Deliver Nitric Oxide and Combat Bacterial Biofilm.

In this study, an antimicrobial platform in the form of nitric oxide (NO) gas-releasing polydopamine (PDA)-coated iron oxide nanoparticles (IONPs) is developed for combating bacterial biofilms. NO is bound to the PDA-coated IONPs via the reaction between NO and the secondary amine moieties on PDA to form N-diazeniumdiolate (NONOate) functionality. To impart colloidal stability to the nanoparticles in aqueous solutions (e.g., phosphate buffered saline (PBS) and bacteria cell culture media M9), a polymer bearing hydrophilic and amine pendant groups, P(OEGMA)-b-P(ABA), is synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization and is subsequently grafted onto the PDA-coated IONPs by employing the Schiff base/Michael addition reaction between o-quinone and a primary amine. These nanoparticles are able to effectively disperse Pseudomonas aeruginosa biofilms (up to 79% dispersal) at submicromolar NO concentrations. In addition, the nanoparticles demonstrate excellent bactericidal activity toward P. aeruginosa planktonic and biofilm cells (up to 5-log10 reduction).

Macromol. Rapid Commun. 11/2016.

Back Cover: Polymers featuring photoresponsive groups have been exploited as promising drug delivery systems. Light as spatially and temporally controllable external stimulus can be readily tuned and focused to trigger changes in the structure of polymer chains to provide "on-command" drug delivery. A benign synthesis route for a novel controlled polymerization, known as photoinduced electron/energy transfer-reversible addition-fragmentation (PET-RAFT) polymerization, is presented. Further details can be found in the article by A. Bagheri, J. Yeow, H. Arandiyan, J. Xu, C. Boyer,* and M. Limon page 905.

Polymerization of a Photocleavable Monomer Using Visible Light.

The polymerization of the photocleavable monomer, o-nitrobenzyl methacrylate (NBMA), is investigated using photoinduced electron/energy transfer reversible addition-fragmentation chain transfer polymerization. The polymerizations under visible red (λ max = 635 nm, 0.7 mW cm(-2) ) and yellow (λ max = 560 nm, 9.7 mW cm(-2) ) light are performed and demonstrate rational evidence of a controlled/living radical polymerization process. Well-defined poly(o-nitrobenzyl methacrylate) (PNBMA) homopolymers with good control over the molecular weight and polymer dispersity are successfully synthesized by varying the irradiation time and/or targeted degree of polymerization. Chain extension of a poly(oligo(ethylene glycol) methyl ether methacrylate) macro-chain transfer agent with NBMA is carried out to fabricate photocleavable amphiphilic block copolymers (BCP). Finally, these self-assembled BCP rapidly dissemble under UV light suggesting the photoresponsive character of NBMA is not altered during the polymerization under yellow or red light. Such photoresponsive polymers can be potentially used for the remote-controlled delivery of therapeutic compounds.

Single versus combination tocolytic regimen in the prevention of preterm births in women: a prospective cohort study.

OBJECTIVE: Our objective is to compare the efficacy of combination regimen (salbutamol and nifedipine) against single regimen (nifedipine alone) in preventing preterm births among women with preterm labor. RESULTS: A total of 76 women with gestational age (GA) ranging from 24+0 to 35+6 weeks, who sought treatment for preterm labor with or without cervical dilatation, were recruited for the prospective cohort study. Of these, 38 (50%) had single tocolytic regimen and 38 (50%) had combination tocolytic regimen. The mean GAs at admission were similar for both groups at 31 weeks (±2.93) for Group 1 and 30.9 weeks (±2.88) for Group 2 (P=0.873). The mean GAs at delivery were 37.8 weeks (±1.98) for the single regimen and 36.2 weeks (±3.26) for the combined regimen (P=0.011). The mean tocolytic to delivery interval for the single regimen was longer at 6.74 weeks (±3.13) as compared with 5.21 weeks (±3.61) for the combination regimen (P<0.05). Those on the combination regimen complained of more adverse effects (P<0.001). CONCLUSION: Our study results suggested that the use of nifedipine as a single tocolytic regimen is as effective as the combination regimen in the delay of preterm births and has much less side effects. Hence, we recommend the sole use of nifedipine for the management of preterm labor.

Resilience, stressful life events, and depressive symptomatology among older Chinese adults.

OBJECTIVE: The association between exposure to stressful life events (SLEs) and late-life depression is well-documented. However, the role of resilience as a buffer against the adverse mental health effects of SLEs in late life has not been convincingly demonstrated. In this paper, the moderating effect of resilience in the relationship between SLEs and depressive symptomatology in older Chinese adults is investigated. METHOD: A population sample of 385 community-dwelling older Chinese adults aged ≥60 years responded to questionnaires on resilience (Connor-Davidson resilience scale), depressive symptomatology (Geriatric Depression Scale, GDS-15) and SLEs. RESULTS: Increased numbers of SLEs (ß = 0.343, p < .001) and lower levels of resilience (ß = -0.137, p < 0.001) were significantly associated with higher levels of depressive symptomatology. There was a significant interaction of resilience and number of SLEs on depressive symptomatology (p = 0.003). The sense of personal competence and optimism was the principal underlying resilience dimension moderating the relationship for both the young-old (aged 60-69) and the old-old (aged 70 and above). CONCLUSION: The finding of significant interaction supported the role of resilience in moderating the adverse effect of SLEs in terms of depressive symptoms among older Chinese adults.

Increased frequency of suppressive regulatory T cells and T cell-mediated antigen loss results in murine melanoma recurrence.

Therapeutic treatment of large established tumors using immunotherapy has yielded few promising results. We investigated whether adoptive transfer of tumor-specific CD8(+) T cells, together with tumor-specific CD4(+) T cells, would mediate regression of large established B16BL6-D5 melanomas in lymphopenic Rag1(-/-) recipients devoid of regulatory T cells. The combined adoptive transfer of subtherapeutic doses of both TRP1-specific TCR transgenic Rag1(-/-) CD4(+) T cells and gp100-specific TCR transgenic Rag1(-/-) CD8(+) T cells into lymphopenic recipients, who received vaccination, led to regression of large (100-400 mm(2)) melanomas. The same treatment strategy was ineffective in lymphoreplete wild-type mice. Twenty-five percent of mice (15/59) had tumors recur (15-180 d postregression). Recurrent tumors were depigmented and had decreased expression of gp100, the epitope targeted by the CD8(+) T cells. Mice with recurrent melanoma had increased CD4(+)Foxp3(+) TRP1-specific T cells compared with mice that did not show evidence of disease. Importantly, splenocytes from mice with recurrent tumor were able to suppress the in vivo therapeutic efficacy of splenocytes from tumor-free mice. These data demonstrate that large established tumors can be treated by a combination of tumor-specific CD8(+) and CD4(+) T cells. Additionally, recurrent tumors exhibited decreased Ag expression, which was accompanied by conversion of the therapeutic tumor-specific CD4(+) T cell population to a Foxp3(+)CD4(+) regulatory T cell population.

Understanding the stimulus of an air-jet aesthesiometer: computerised modelling and subjective interpretation.

PURPOSE: Assessment of corneal sensory function is more frequently being carried out using novel non-contact methods, which promise better stimulus control and a greater intensity range than more traditional techniques. An examination of the characteristics of the air-jet stimulus of these 'non-contact' aesthesiometers is important to enable an understanding of how these instruments stimulate the cornea. The purpose of this study was to model the air-jet stimulus of the CRCERT-Belmonte Aesthesiometer (CBA) and its interaction with the cornea. METHOD: A computerised simulation was used to model the CBA stimulus and this model was then examined in the context of verbal descriptions of the supra-threshold stimulus provided by 27 human subjects with normal corneas. The computational fluid dynamics model and the subjective descriptions considered CBA airflow values between 70 and 400 mL min(-1) . RESULTS: The computational fluid dynamics results showed that the CBA air-jet stimulus behaves as expected in terms of force exerted and stabilises and subsides quickly during the 1 s duration for which it is turned on/off. The computer modelling demonstrated that the stimulus of the CBA consists of a central core of air flow, similar in diameter to the CBA nozzle, which exerts maximum pressure at the corneal apex. This core is surrounded by a less prominent zone of lower pressure, extending out to the corneal periphery at higher flow rates. The computer modelling results were confirmed by the subjective descriptions of intensity and corneal area stimulated, whereas relation to duration of sensation was more equivocal. CONCLUSIONS: The CBA probably stimulates sensory receptors over a greater area of the ocular surface compared to the traditional nylon filament aesthesiometer and may recruit neurons sensitive to additional stimulus modalities. Future computational models should also incorporate temperature as an important aspect of the corneal response. This study has effectively demonstrated that it is possible to create a virtual model of an air-jet aesthesiometer stimulus using computational methods and that this model is corroborated by subjective descriptions provided by subjects.

Insight into serum protein interactions with functionalized magnetic nanoparticles in biological media.

Surface modification with linear polymethacrylic acid (20 kDa), linear and branched polyethylenimine (25 kDa), and branched oligoethylenimine (800 Da) is commonly used to improve the function of magnetite nanoparticles (MNPs) in many biomedical applications. These polymers were shown herein to have different adsorption capacity and anticipated conformations on the surface of MNPs due to differences in their functional groups, architectures, and molecular weight. This in turn affects the interaction of MNPs surfaces with biological serum proteins (fetal bovine serum). MNPs coated with 25 kDa branched polyethylenimine were found to attract the highest amount of serum protein while MNPs coated with 20 kDa linear polymethacrylic acid adsorbed the least. The type and amount of protein adsorbed, and the surface conformation of the polymer was shown to affect the size stability of the MNPs in a model biological media (RPMI-1640). A moderate reduction in r(2) relaxivity was also observed for MNPs suspended in RPMI-1640 containing serum protein compared to the same particles suspended in water. However, the relaxivities following protein adsorption are still relatively high making the use of these polymer-coated MNPs as Magnetic Resonance Imaging (MRI) contrast agents feasible. This work shows that through judicious selection of functionalization polymers and elucidation of the factors governing the stabilization mechanism, the design of nanoparticles for applications in biologically relevant conditions can be improved.

Changes in depressive symptoms and functional disability among community-dwelling depressive older adults.

BACKGROUND: Previous studies have shown that the presence of depressive symptoms among older persons was evidently associated with subsequent physical and functional decline. However, few studies have directly examined the impact of changes in depressive symptoms or depressed mood on changes in functional ability. The present prospective study examined whether changes in the levels and remission of depressive symptoms were associated with changes in functional ability among community-living older persons who were treated for depressive symptoms in a primary care setting. METHODS: Older persons aged 60 and above with depressive symptoms (N = 267) were followed up in a primary care treatment program over 12 months. Geriatric Depression Scale (GDS-15), and instrumental and basic activities of daily living (IADL and ADL) were measured at baseline and at 12-month follow-up. The associations of GDS change scores and conversion to non-depressed status with ADL and IADL change scores, controlling for baseline covariates including chronic medical comorbidity and Mini-Mental State Examination (MMSE), were examined in multiple regression analyses. RESULTS: An improvement in GDS scores (baseline score minus 12-month score) was significantly associated with improvement (12-month score minus baseline score) in ADL (ß = 0.355, p < 0.001) and IADL scores (ß = 0.165, p = 0.018) after adjusting for baseline functional status, MMSE, chronic medical comorbidities, and other variables. In particular, conversion in GDS status to "non-depressive" state (GDS ≤4) was associated with an improvement in ADL change scores (ß = 0.281, p = 0.019). CONCLUSION: In depressed older persons, an improvement in depressive symptoms was associated with improved functional ability.

Long-term digital mobile phone use and cognitive decline in the elderly.

Research on long-term exposure to electromagnetic fields on cognition is lacking. We investigated the associations between frequent digital mobile phone use and global and domain-specific cognitive changes in older persons, a vulnerable group experiencing age-associated cognitive decline. We assessed 871 non-demented Chinese participants in the Singapore Longitudinal Ageing Studies cohort on the frequency of digital mobile phone use, neurocognitive performance and confounding variables at baseline, and neurocognitive performance at the 4-year follow-up. Findings showed that digital mobile phone users were typically self-selected to possess characteristics favoring better cognitive functioning and concomitantly demonstrate better performance on cognitive tasks. There was evidently no significant deleterious effect of digital mobile phone use on cognitive functioning in older people. Findings suggest, however, that digital mobile phone use may have an independent facilitating effect on global and executive functioning.

Pulmonary function and cognitive decline in an older Chinese population in Singapore.

INTRODUCTION: Various cognitive deficits associated with reduced pulmonary function are reported in different studies, but the pattern of cognitive deficits across multiple domains and its associated everyday functional disability remain unclear. METHODS: We analyzed neuropsychological functioning, cognitive impairment and accompanying disability in instrumental activities of daily living (IADL) associated with reduced pulmonary function in community-living middle-aged and older adults in Singapore. Performance on a comprehensive battery of neuropsychological tests, spirometry and cognitively demanding IADLs were assessed in the population-based Singapore Longitudinal Ageing Studies. RESULTS: Consecutive 10% increase in forced expiratory volume in 1 s (FEV1) as percent of predicted was positively associated with 0.18 points increase in Mini-mental state examination (MMSE) and 0.04 points increase in executive function, independent of age, education and other variables. Subjects with moderate-to-severe airway obstruction showed significantly poorer MMSE score (p for linear trend = 0.001), and information processing speed (p for linear trend < 0.001). FEV1 (per 10% of predicted) was significantly associated with lower risk of cognitive impairment (OR = 0.92, 95% CI: 0.87-0.98, P = 0.005) and cognitive IADL disability (OR = 0.86,95% CI:0.79-0.93, P < 0.001). Pulmonary restriction was associated with greater risk of cognitive impairment (OR = 1.98, 95% CI: 1.26-3.11, P = 0.003) and cognitive IADL disability (OR = 2.43, 95% CI: 1.31-4.53, P = 0.005). Moderate-to-severe airway obstruction (OR = 2.04, 95% CI: 1.11-3.74, P = 0.022) was positively associated with cognitive IADL disability. CONCLUSION: The findings suggest a measurable but modest cognitive effect of low pulmonary function that was accompanied by corresponding disability in living activities. The effect on executive functioning should be further investigated in longitudinal studies.

The biochemiresistor: an ultrasensitive biosensor for small organic molecules.

New sensation: A resistance-based biosensor uses gold-coated magnetic nanoparticles (Au@MNPs) functionalized with the antibiotic enrofloxin (see picture; purple), which bind to anti-enrofloxin as analyte (blue). The Au@MNPs can be magnetically assembled between electrodes, and the measured resistance R is a function of analyte concentration.

Integrating external beam and prostate seed implant dosimetry for intermediate and high-risk prostate cancer using biologically effective dose: Impact of image registration technique.

PURPOSE: Combining external beam radiation therapy (EBRT) and prostate seed implant (PSI) is efficacious in treating intermediate- and high-risk prostate cancer at the cost of increased genitourinary toxicity. Accurate combined dosimetry remains elusive due to lack of registration between treatment plans and different biological effect. The current work proposes a method to convert physical dose to biological effective dose (BED) and spatially register the dose distributions for more accurate combined dosimetry. METHODS AND MATERIALS: A PSI phantom was CT scanned with and without seeds under rigid and deformed transformations. The resulting CTs were registered using image-based rigid registration (RI), fiducial-based rigid registration (RF), or b-spline deformable image registration (DIR) to determine which was most accurate. Physical EBRT and PSI dose distributions from a sample of 91 previously-treated combined-modality prostate cancer patients were converted to BED and registered using RI, RF, and DIR. Forty-eight (48) previously-treated patients whose PSI occurred before EBRT were included as a "control" group due to inherent registration. Dose-volume histogram (DVH) parameters were compared for RI, RF, DIR, DICOM, and scalar addition of DVH parameters using ANOVA or independent Student's t tests (α = 0.05). RESULTS: In the phantom study, DIR was the most accurate registration algorithm, especially in the case of deformation. In the patient study, dosimetry from RI was significantly different than the other registration algorithms, including the control group. Dosimetry from RF and DIR were not significantly different from the control group or each other. CONCLUSIONS: Combined dosimetry with BED and image registration is feasible. Future work will utilize this method to correlate dosimetry with clinical outcomes.

Stabilization of magnetic iron oxide nanoparticles in biological media by fetal bovine serum (FBS).

A facile method of stabilizing magnetic iron oxide nanoparticles (MNPs) in biological media (RPMI-1640) via surface modification with fetal bovine serum (FBS) is presented herein. Dynamic light scattering (DLS) shows that the size of the MNP aggregates can be maintained at 190 ± 2 nm for up to 16 h in an RPMI 1640 culture medium containing ≥4 vol % FBS. Under transmission electron microscopy (TEM), a layer of protein coating is observed to cover the MNP surface following treatment with FBS. The adsorption of proteins is further confirmed by X-ray photoelectron spectroscopy (XPS). Gel electrophoresis and LC-MS/MS studies reveal that complement factor H, antithrombin, complement factor I, α-1-antiproteinase, and apolipoprotein E are the proteins most strongly attached to the surface of an MNP. These surface-adsorbed proteins serve as a linker that aids the adsorption of other serum proteins, such as albumin, which otherwise adsorb poorly onto MNPs. The size stability of FBS-treated MNPs in biological media is attributed to the secondary adsorbed proteins, and the size stability in biological media can be maintained only when both the surface-adsorbed proteins and the secondary adsorbed proteins are present on the particle's surface.