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This study tested a model in which bicultural self-efficacy is associated with bicultural identity integration (BII), which, in turn, is associated with psychological well-being, both associations being moderated by critical consciousness of racism. Participants were 289 people of color who identify as bicultural residing in the United States (Mean age = 30.73, SD = 7.31). The study utilized a cross-sectional design. A path analysis was conducted using PROCESS MACRO. Bicultural self-efficacy was associated with both the harmony and blendedness components of BII. The association between bicultural self-efficacy and the harmony component of BII was moderated by critical consciousness of racism such that the association between bicultural self-efficacy and harmony was significant for only those with low and medium levels of critical consciousness of racism. Additionally, the blendedness component of BII was associated with psychological well-being more strongly as the level of critical consciousness of racism increased. This study highlights how critical consciousness of racism may hinder a person from achieving a high BII despite having high bicultural self-efficacy. Additionally, once BII is accomplished, critical consciousness of racism could synergistically contribute to increased psychological well-being of people of color. Implications for mental health professionals and policy makers are reviewed. [ABSTRACT FROM AUTHOR]

Background: Protein powder identification presents a challenge in quality control. There is current deliberation of the specificity of methods for the identification of milk proteins, and the consensus identification method of whey protein from the United States Pharmacopeia Food Chemical Codex relies on a combined analysis of the testing of ash, fat, lactose, loss on drying, and protein. These methods are non-specific. Milk and whey proteins both contain background DNA content. Both milk and whey proteins retain source DNA (cow), but also have bacterial DNA from natural flora, the dairy plant, and in whey protein, the cheesemaking process. The DNA in these materials is retained post-processing, even after the pasteurization process. Objective: By utilizing 16S metagenomics, the bacterial DNA in protein powders can be sequenced and cross-referenced to a curated library to ultimately create a microbiome profile of these raw materials. This microbiome can be measured for alpha and beta diversity, specifically how many and which species of bacteria are present. Method: Using 16S metagenomics, we measure alpha and beta diversity of the microbiome profile of each protein powder and use principle coordinate analysis to produce differential groupings, providing a novel identification method for raw materials. Results: In this study, we demonstrate that the microbiome of cow proteins can be used for raw material identification, as the microbiome of milk and whey proteins differ significantly. We also demonstrate that the microbiome of whey protein concentrate can differ from supplier to supplier. Conclusions: Microbiome profiling by 16S metagenomics can be an important forensic tool for quality control. Highlights: Principle Coordinate Analysis can be used as a statistical tool for protein differentiation using the protein microbiome. [ABSTRACT FROM AUTHOR]

Background: Differentiation of proteins from multiple sources provides challenges in the accuracy using multiple and often disputed protein identification methods. The U.S. Pharmacopeia Food Chemical Codex does not include monographs for many protein sources, including milk proteins and soy protein isolate. Monographs that are included for proteins do not list a single comprehensive identification method but instead rely on a combined assessment of ash (total), fat, lactose, loss on drying, and protein content. A fast, inexpensive, and accurate protein source assay is tantamount to prevention of economic adulteration in protein powders. Objective: This study describes the development of a novel method to identify and differentiate animal proteins (cow protein powders as milk protein and whey protein) and plant proteins (soy protein powders). These proteins powders are of high importance to the food and dietary supplement industries, as they encompass the highest grossing and fastest growing protein sources in the global protein powder market. Methods: The developed method uses PCR amplification and gel electrophoresis of short chain DNA fragments found in processed protein powders to identify and differentiate the source of each powder. The original development was performed using reference materials of known identity and tested against an inclusivity panel of protein powders from commercial sources. Bands were identified using the Agilent Tapestation 4200 and Tapestation Analysis Software A.02.02 (SR1) using proprietary band analysis. Results: The developed method was found to be specific for the identification of each protein source, passing a computational (National Center for Biotechnology Information Basic Local Alignment Search Tool) exclusivity panel and an experimental inclusivity panel. The method was also able to detect multiple adulterants in concentrations as low as 1% (w/w). Conclusions: The developed method is fast, inexpensive, and accurate (100%) for the supplemental identification of cow and soy proteins and able to detect adulteration as low as 1% (w/w). Highlights: A new method can identify cow and soy proteins, and detect low levels of adulteration using DM-PCR. [ABSTRACT FROM AUTHOR]

A new method is described for preparing controllably displaceable monolayers by using a carboxyl-functionalized self-assembled monolayer and in situ Fischer esterification, simple and reversible chemical reaction. The generality of reversible lability is examined by applying the in situ esterification reaction to the structurally distinct carboxyl-functionalized molecule 3-mercapto-1-adamantanecarboxylic acid.

Background: The applications of deoxyribonucleic acid (DNA) barcoding methods have been extended from authenticating taxonomic provenance of animal products to identifying botanicals used as herbal medicine and in botanical dietary supplements. DNA barcoding methods for botanical identification must be adequately validated to meet regulatory compliance. Objective: The goal of this study is to provide a validation protocol for a two-tiered DNA barcoding method that aims to identify raw botanicals. Methods: A barcode database was computationally validated to define the barcode combinations that can unambiguously identify botanicals in the database. A maximum variation sampling technique was used to capture a wide range of perspectives relating to DNA barcodebased botanical identification, including plant parts and species distance, for the experimental validation. Twenty-two authenticated botanicals were purposively sampled from different plant parts--covering both closely related and distantly related species--to validate the two-tiered DNA barcoding method. The performance of the method was assessed on accuracy, precision, ruggedness, and uncertainty. Results: High accuracy (100%) and precision (1.0) were obtained from the validation samples. The method was also found to be rugged and have acceptable uncertainty. Conclusions: The method was validated and suitable for DNA-based identification of botanical raw materials listed in Dieta ry Supplements and Traditional Medicine Single-Laboratory Validation of a Two-Tiered DNA Barcoding Method for Raw Botanical Identification Zhengfei Lu Herbalife Nutrition, 950 West 190th St, Torrance, CA 90502 Christopher M. Thompson Herbalife Manufacturing, LLC, 20481 Crescent Bay Dr, Lake Forest, CA 92630 Tiffany Chua, Silva Babajanian, and Yanjun Zhang Herbalife Nutrition, 950 West 190th St, Torrance, CA 90502 Quanyin Gao Herbalife Manufacturing, LLC, 20481 Crescent Bay Dr, Lake Forest, CA 92630 Peter Chang and Gary Swanson Herbalife Nutrition, 950 West 190th St, Torrance, CA 90502 DOI: https://doi.org/10.5740/jaoacint.18-0130 the current database. Highlights: This work will provide support guidance for manufacturers and regulatory policy makers to implement equivalent validated and compliant DNA-based testing in quality control processes to improve botanical raw material identification and authentication. [ABSTRACT FROM AUTHOR]

This paper describes a procedure for transferring colloidal CdS and CdSe quantum dots (QDs) from organic solvents to water by exchanging their native hydrophobic ligands for phosphonopropionic acid (PPA) ligands, which bind to the QD surface through the phosphonate group. This method, which uses dimethylformamide as an intermediate transfer solvent, was developed in order to produce high-quality water-soluble QDs with neither a sulfur-containing ligand nor a polymer encapsulation layer, both of which have disadvantages in applications of QDs to photocatalysis and biological imaging. CdS (CdSe) QDs were transferred to water with a 43% (48%) yield using PPA. The photoluminescence (PL) quantum yield for PPA-capped CdSe QDs is larger than that for QDs capped with the analogous sulfur-containing ligand, mercaptopropionic acid (MPA), by a factor of 4 at pH 7, and by up to a factor of 100 under basic conditions. The MPA ligands within MPA-capped QDs oxidize at Eox ∼ +1.7 V versus SCE, whereas cyclic voltammograms of PPA-capped QDs show no discerible oxidation peaks at applied potentials up to +2.5 V versus SCE. The PPA-capped QDs are chemically and colloidally stable for at least 5 days in the dark, even in the presence of O2, and are stable when continuously illuminated for 5 days, when oxygen is excluded and a sacrificial reductant is present to capture photogenerated holes. [ABSTRACT FROM AUTHOR]

Epidemiological studies have established alcohol and smoking as independent risk factors for recurrent acute pancreatitis and chronic pancreatitis. However, the molecular players responsible for the progressive loss of pancreatic parenchyma and fibroinflammatory response are poorly characterized. Tandem mass tag–based proteomic and bioinformatics analyses were performed on the pancreata of mice exposed to alcohol, cigarette smoke, or a combination of alcohol and cigarette smoke. Biochemical, immunohistochemistry, and transcriptome analyses were performed on the pancreatic tissues and primary acinar cells treated with cerulein in combination with ethanol (50 mmol/L) and cigarette smoke extract (40 μg/mL) for the mechanistic studies. A unique alteration in the pancreatic proteome was observed in mice exposed chronically to the combination of alcohol and cigarette smoke (56.5%) compared with cigarette smoke (21%) or alcohol (17%) alone. The formation of toxic metabolites (P <.001) and attenuated unfolded protein response (P <.04) were the significantly altered pathways on combined exposure. The extracellular matrix (ECM) proteins showed stable malondialdehyde-acetaldehyde (MAA) adducts in the pancreata of the combination group and chronic pancreatitis patients with a history of smoking and alcohol consumption. Interestingly, MAA-ECM adducts significantly suppressed expression of X-box-binding protein-1, leading to acinar cell death in the presence of alcohol and smoking. The stable MAA-ECM adducts persist even after alcohol and smoking cessation, and significantly delay pancreatic regeneration by abrogating the expression of cyclin-dependent kinases (CDK7 and CDK5) and regeneration markers. The combined alcohol and smoking generate stable MAA-ECM adducts that increase endoplasmic reticulum stress and acinar cell death due to attenuated unfolded protein response and suppress expression of cell cycle regulators. Targeting aldehyde adducts might provide a novel therapeutic strategy for the management of recurrent acute pancreatitis and chronic pancreatitis. Alcohol and smoking combined generate the stable aldehyde adducts on extracellular matrix proteins leading to impaired unfolded protein response resulting in loss of pancreatic parenchyma and poor regeneration after pancreatic insult. [ABSTRACT FROM AUTHOR]

Background: There is a great interest in studying phosphotyrosine dependent protein-protein interactions in tyrosine kinase pathways that play a critical role in many aspects of cellular function. We previously established SH2 profiling, a phosphoproteomic approach based on membrane binding assays that utilizes purified Src Homology 2 (SH2) domains as a molecular tool to profile the global tyrosine phosphorylation state of cells. However, in order to use this method to investigate SH2 binding sites on a specific target in cell lysate, additional procedures such as pull-down or immunoprecipitation which consume large amounts of sample are required. Results: We have developed PLA-SH2, an alternative in-solution modular domain binding assay that takes advantage of Proximity Ligation Assay and real-time PCR. The SH2-PLA assay utilizes oligonucleotide-conjugated anti-GST and anti-EGFR antibodies recognizing a GST-SH2 probe and cellular EGFR, respectively. If the GST-SH2 and EGFR are in close proximity as a result of SH2-phosphotyrosine interactions, the two oligonucleotides are brought within a suitable distance for ligation to occur, allowing for efficient complex amplification via real-time PCR. The assay detected signal across at least 3 orders of magnitude of lysate input with a linear range spanning 1-2 orders and a low femtomole limit of detection for EGFR phosphotyrosine. SH2 binding kinetics determined by PLA-SH2 showed good agreement with established far-Western analyses for A431 and Cos1 cells stimulated with EGF at various times and doses. Further, we showed that PLA-SH2 can survey lung cancer tissues using 1 μl lysate without requiring phospho-enrichment. Conclusions: We showed for the first time that interactions between SH2 domain probes and EGFR in cell lysate can be determined in a microliter-scale assay using SH2-PLA. The obvious benefit of this method is that the low sample requirement allows detection of SH2 binding in samples which are difficult to analyze using traditional protein interaction assays. This feature along with short assay runtime makes this method a useful platform for the development of high throughput assays to determine modular domain-ligand interactions which could have wide-ranging applications in both basic and translational cancer research. [ABSTRACT FROM AUTHOR]

Summary: Members of the SH2 domain family modulate signal transduction by binding to short peptides containing phosphorylated tyrosines. Each domain displays a distinct preference for the sequence context of the phosphorylated residue. We have developed a high-density peptide chip technology that allows for probing of the affinity of most SH2 domains for a large fraction of the entire complement of tyrosine phosphopeptides in the human proteome. Using this technique, we have experimentally identified thousands of putative SH2-peptide interactions for more than 70 different SH2 domains. By integrating this rich data set with orthogonal context-specific information, we have assembled an SH2-mediated probabilistic interaction network, which we make available as a community resource in the PepspotDB database. A predicted dynamic interaction between the SH2 domains of the tyrosine phosphatase SHP2 and the phosphorylated tyrosine in the extracellular signal-regulated kinase activation loop was validated by experiments in living cells. [Copyright &y& Elsevier]

Summary: Protein tyrosine phosphorylation controls many aspects of signaling in multicellular organisms. One of the major consequences of tyrosine phosphorylation is the creation of binding sites for proteins containing Src homology 2 (SH2) domains. To profile the global tyrosine phosphorylation state of the cell, we have developed proteomic binding assays encompassing nearly the full complement of human SH2 domains. Here we provide a global view of SH2 domain binding to cellular proteins based on large-scale far-western analyses. We also use reverse-phase protein arrays to generate comprehensive, quantitative SH2 binding profiles for phosphopeptides, recombinant proteins, and entire proteomes. As an example, we profiled the adhesion-dependent SH2 binding interactions in fibroblasts and identified specific focal adhesion complex proteins whose tyrosine phosphorylation and binding to SH2 domains are modulated by adhesion. These results demonstrate that high-throughput comprehensive SH2 profiling provides valuable mechanistic insights into tyrosine kinase signaling pathways. [Copyright &y& Elsevier]

Background: In addition to psychological disorders, emotional stress can trigger a chain of neurohumoral imbalances that can manifest as cardiopulmonary complaints. No studies were identified that used objective clinical data on complaints after the terrorist attacks of September 11, 2001. The purpose of this descriptive study was to identify all cardiopulmonary and psychological diagnoses among active duty personnel seeking care at a military treatment facility and/or its ancillary facilities before and after September 11, 2001.Methods: The study population included 40,981 active duty military personnel between August 13, 2001 and October 9, 2001 (4 weeks before and 4 weeks after September 11, 2001). Demographic and diagnostic data were obtained from the Composite Health Care System for each visit during the study period. The outcomes of interest were psychological and cardiopulmonary diagnoses.Results: There were 19,595 clinic visits before September 11, 2001 compared to 19,207 clinic visits in the 4 weeks after September 11. There was no increase in total psychological diagnoses in the postexposure period, compared with the preexposure period (risk ratio (RR), 0.97; 95% confidence interval (CI), 0.84-1.11). The only statistically significant finding was a decrease in diagnoses of psychoses (RR, 0.62; 95% confidence interval, 0.42-0.91). However, diagnoses of depressive disorders were increased in the postexposure period (RR, 1.61; 95% CI, 0.89-2.90; p = 0.11). Total cardiopulmonary diagnoses did not increase in the postexposure period, compared with the preexposure period (RR, 0.96; 95% CI, 0.91-1.02).Conclusions: This descriptive study failed to identify evidence that any changes in cardiopulmonary or mental health diagnoses were attributable to September 11 terrorist attacks. In the unfortunate event of another national tragedy, it is recommended that health care professionals administer a questionnaire to determine why patients are seeking care after the tragedy. These data could be linked to International Classification of Diseases data to determine the effects of the tragedy on the health of personnel and their utilization of health care services. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy demonstrating aberrant and progressive expression of mucins. The contribution of individual mucins has been extensively investigated in PDAC; however, comprehensive mucin profiling including splice variants in PDAC tumors has not been reported., Experimental Design: Using publicly available RNA sequencing (RNA-seq) datasets, we assess the expression of mucin family members and their splice variants (SV) in PDAC tumor samples for the first time. Mucin SVs that are correlated with PDAC patient survival are validated in a cohort of patient tumor samples. Further, we use computational methods to derive novel pancreatic tumor subtypes using mucin expression signatures and their associated activated pathways., Results: Principal component analysis identified four novel mucin-based PDAC subtypes. Pathway analysis implicated specific biological signatures for each subtype, labeled (i) immune activated, (ii) progressive, (iii) pancreatitis-initiated, and (iv) anti-inflammatory/PanIN-initiated. Assessing mucin SVs, significantly longer survival is observed with higher expression of 4 MUC1 and 1 MUC13 SVs, whereas patients expressing 2 MUC4 and 1 MUC16 SVs had shorter survival. Using a whole-transcriptome correlation, a three-gene panel, including ESRP2 , PTK6 , and MAGEH1 , is designated to assess PDAC tumor sample cellularity by PCR. One MUC4 SV and one MUC13 SV are quantified in a separate PDAC patient cohort, and their effects on survival are experimentally validated., Conclusions: Altogether, we demonstrate the unique expression pattern of mucins, four mucin-based PDAC subtypes, and the contribution of MUC1 , MUC4 , and MUC16 SVs in PDAC patient survival., (©2021 American Association for Cancer Research.)

Purpose: The cytokine milieu in pancreatic ductal adenocarcinoma (PDAC) promotes tumor progression and immune suppression, contributing to the dismal prognosis of patients with PDAC. The roles of many of these cytokines, however, have not been thoroughly investigated in PDAC., Experimental Design: PDAC microarray and The Cancer Genome Atlas datasets were analyzed to identify cytokines and cognate receptors overexpressed in PDAC and associated with survival. Pathway and CIBERSORT analyses were used to elucidate potential mechanisms of altered patient survival. Comparative analysis of cytokine expression in KPC (K-ras G12D ; TP53 R172H ; Pdx-1cre) and KC (K-ras G12D ; Pdx-1cre) PDAC models and multicolor immunofluorescence (IF) staining of human PDAC-resected samples were used to validate these findings., Results: CXCL9 and CXCL10 were among the most highly overexpressed cytokines by bioinformatics analyses, while their receptor, CXCR3, was significantly overexpressed by IHC analysis. Higher CXCR3 ligand expression was associated with shorter overall survival, while high CXCR3 expression was associated with better survival. The CXCR3 ligands, CXCL4 , 9 , and 10 , were overexpressed in KPC compared with KC mice. Pathway analysis of CXCR3- and CXCR3 ligand-associated genes showed that CXCR3 is a marker of antitumor immunity, while its ligands may promote immunosuppression. CIBERSORT and IF studies of PDAC tissues demonstrated that high CXCR3 expression was associated with increased CD8 + T-cell and naïve B-cell signatures and loss of plasma cell signatures. CXCR3 ligand expression was associated with increased CD8 + T-cell signatures and loss of natural killer-cell signatures., Conclusions: CXCR3 ligands are overexpressed in PDAC and are associated with poor survival likely related to alterations in tumor immune infiltrate/activity., (©2020 American Association for Cancer Research.)

BackgroundThe higher level of background parenchymal enhancement (BPE) at breast MRI has the potential for early detection and prediction of the risk of breast cancer. However, conflicting findings have been reported about the association between the level of BPE at breast MRI and the presence of breast cancer.PurposeTo evaluate the association between qualitative and quantitative BPE at dynamic contrast material-enhanced MRI and breast cancer among populations with average risk and high risk separately.Materials and MethodsA retrospective meta-analysis of observational studies comparing either qualitative or quantitative assessments of BPE in women with and women without breast cancer was performed for studies published through July 2018. Pooled odds ratios (ORs) or standardized mean differences and 95% confidence intervals (CIs) were estimated by using DerSimonian-Laird random-effects models. The heterogeneity across the studies was measured by using the statistic I  2 . Sensitivity analyses were conducted to test this association according to different study characteristics. P values less than or equal to 5% were considered to indicate statistically significant results.ResultsEighteen studies comprising 1910 women with breast cancer and 2541 control participants were included in the analysis. Among women with high risk, at least moderate BPE (OR, 1.6; 95% CI: 1.0, 2.6; P = .04) or at least mild BPE (OR, 2.1; 95% CI: 1.5, 3.0; P < .001) was associated with higher odds of breast cancer. Furthermore, women with breast cancer showed a higher average BPE percentage compared with control participants with high risk (standardized mean difference, 0.5; 95% CI: 0.2, 0.9; P = .001). No association was observed between at least mild BPE level ( P = .15) or at least moderate BPE level ( P = .38) and the presence of breast cancer among the population with average risk.ConclusionA higher level of background parenchymal enhancement measured at breast MRI is associated with the presence of breast cancer in women with high risk, but not in women with average risk.© RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Mann and Pinker in this issue.

Background: The applications of deoxyribonucleic acid (DNA) barcoding methods have been extended from authenticating taxonomic provenance of animal products to identifying botanicals used as herbal medicine and in botanical dietary supplements. DNA barcoding methods for botanical identification must be adequately validated to meet regulatory compliance. Objective: The goal of this study is to provide a validation protocol for a two-tiered DNA barcoding method that aims to identify raw botanicals. Methods: A barcode database was computationally validated to define the barcode combinations that can unambiguously identify botanicals in the database. A maximum variation sampling technique was used to capture a wide range of perspectives relating to DNA barcode-based botanical identification, including plant parts and species distance, for the experimental validation. Twenty-two authenticated botanicals were purposively sampled from different plant parts-covering both closely related and distantly related species-to validate the two-tiered DNA barcoding method. The performance of the method was assessed on accuracy, precision, ruggedness, and uncertainty. Results: High accuracy (100%) and precision (1.0) were obtained from the validation samples. The method was also found to be rugged and have acceptable uncertainty. Conclusions: The method was validated and suitable for DNA-based identification of botanical raw materials listed in the current database. Highlights: This work will provide support guidance for manufacturers and regulatory policy makers to implement equivalent validated and compliant DNA-based testing in quality control processes to improve botanical raw material identification and authentication.

This paper describes the pH dependence of the excitonic energies and dynamics of CdS quantum dots (QDs) capped with phosphonopropionate (PPA) in water. QDs capped with PPA carry a negative charge on their surfaces upon deprotonation of PPA above pH ∼ 8.5; the resultant electric field induces large changes in the QD's optical properties. Between pH 5.6 and 12.0, an increase in pH is accompanied by a 47-meV bathochromic shift in the bandgap of the QDs and a decrease in the Stokes shift by ∼4.3 meV/pH unit. An increase in the radiative recombination rate by a factor of 20.9 occurs on increasing the pH from 5.6 to 9.4. These observations are attributed to a shifting of the energy levels within the first exciton manifold, and are simulated using time-dependent density functional theory calculations on model Cd 29 S 29 clusters surrounded by point charges.

This work describes the quantitative characterization of the interfacial chemical and electronic structure of CdSe quantum dots (QDs) coated in one of five p-substituted thiophenolates (X-TP, X = NH2, CH3O, CH3, Cl, or NO2), and the dependence of this structure on the p-substituent X. (1)H NMR spectra of mixtures of CdSe QDs and X-TPs yield the number of X-TPs bound to the surface of each QD. The binding data, in combination with the shift in the energy of the first excitonic peak of the QDs as a function of the surface coverage of X-TP and Raman and NMR analysis of the mixtures, indicate that X-TP binds to CdSe QDs in at least three modes, two modes that are responsible for exciton delocalization and a third mode that does not affect the excitonic energy. The first two modes involve displacement of OPA from the QD core, whereas the third mode forms cadmium-thiophenolate complexes that are not electronically coupled to the QD core. Fits to the data using the dual-mode binding model also yield the values of Δr1, the average radius of exciton delocalization due to binding of the X-TP in modes 1 and 2. A 3D parametrized particle-in-a-sphere model enables the conversion of the measured value of Δr1 for each X-TP to the height of the potential barrier that the ligand presents for tunneling of excitonic hole into the interfacial region. The height of this barrier increases from 0.3 to 0.9 eV as the substituent, X, becomes more electron-withdrawing.

Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks. SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute risks are very low, large relative risks become less meaningful. A calculated relative radiation-induced second cancer risk benefit from SABR and FFF techniques was theoretically predicted, although absolute radiation-induced second cancer risks were low for all techniques, and absolute differences between techniques were small.

Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 °C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ∼80 times faster, and the activation energy is ∼5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy.

We synthesize platinum nanoparticles with controlled average sizes of 2, 4, 6, and 8 nm and use them as model catalysts to study isopropanol oxidation to acetone in both the liquid and gas phases at 60 °C. The reaction at the solid/liquid interface is 2 orders of magnitude slower than that at the solid/gas interface, while catalytic activity increases with the size of platinum nanoparticles for both the liquid-phase and gas-phase reactions. The activation energy of the gas-phase reaction decreases with the platinum nanoparticle size and is in general much higher than that of the liquid-phase reaction which is largely insensitive to the size of catalyst nanoparticles. Water substantially promotes isopropanol oxidation in the liquid phase. However, it inhibits the reaction in the gas phase. The kinetic results suggest different mechanisms between the liquid-phase and gas-phase reactions, correlating well with different orientations of IPA species at the solid/liquid interface vs the solid/gas interface as probed by sum frequency generation vibrational spectroscopy under reaction conditions and simulated by computational calculations.

The design and development of metal-cluster-based heterogeneous catalysts with high activity, selectivity, and stability under solution-phase reaction conditions will enable their applications as recyclable catalysts in large-scale fine chemicals production. To achieve these required catalytic properties, a heterogeneous catalyst must contain specific catalytically active species in high concentration, and the active species must be stabilized on a solid catalyst support under solution-phase reaction conditions. These requirements pose a great challenge for catalysis research to design metal-cluster-based catalysts for solution-phase catalytic processes. Here, we focus on a silica-supported, polymer-encapsulated Pt catalyst for an electrophilic hydroalkoxylation reaction in toluene, which exhibits superior selectivity and stability against leaching under mild reaction conditions. We unveil the key factors leading to the observed superior catalytic performance by combining X-ray absorption spectroscopy (XAS) and reaction kinetic studies. On the basis of the mechanistic understandings obtained in this work, we also provide useful guidelines for designing metal-cluster-based catalyst for a broader range of reactions in the solution phase.

Sum frequency generation (SFG) vibrational spectroscopy was employed to characterize the interfacial structure of eight individual amino acids--L-phenylalanine, L-leucine, glycine, L-lysine, L-arginine, L-cysteine, L-alanine, and L-proline--in aqueous solution adsorbed at model hydrophilic and hydrophobic surfaces. Specifically, SFG vibrational spectra were obtained for the amino acids at the solid-liquid interface between both hydrophobic d(8)-polystyrene (d(8)-PS) and SiO(2) model surfaces and phosphate buffered saline (PBS) at pH 7.4. At the hydrophobic d(8)-PS surface, seven of the amino acids solutions investigated showed clear and identifiable C-H vibrational modes, with the exception being l-alanine. In the SFG spectra obtained at the hydrophilic SiO(2) surface, no C-H vibrational modes were observed from any of the amino acids studied. However, it was confirmed by quartz crystal microbalance that amino acids do adsorb to the SiO(2) interface, and the amino acid solutions were found to have a detectable and widely varying influence on the magnitude of SFG signal from water at the SiO(2)/PBS interface. This study provides the first known SFG spectra of several individual amino acids in aqueous solution at the solid-liquid interface and under physiological conditions.

Intravascular contrast agents remain a common cause of acute renal dysfunction, and prolonged intravenous saline administration prior to contrast exposure has been recommended in patients with elevated creatinine levels. For patient convenience and to minimize cost, same-day procedures have become common in patients with moderate renal insufficiency, despite little evidence to support this practice. A randomized trial was therefore performed to compare overnight hydration with bolus hydration in patients with moderate renal insufficiency. Although no overall change in creatinine was seen at 24 or 48 hours, four of the 37 patients (10.8%) in the bolus group versus none of the 26 in the overnight hydration group developed contrast associated nephropathy (CAN; p = 0.136). These results should at least question whether bolus hydration should be considered an equivalent alternative to overnight hydration in patients at risk for CAN undergoing angiography, and encourage further evaluation of this issue.