bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vitamin B12, folate, and the methionine remethylation cycle—biochemistry, pathways, and regulation
Authors: Froese D. Sean , Fowler Brian , Baumgartner Matthias R. 
Published: January 2019

AbstractVitamin B12 (cobalamin, Cbl) is a nutrient essential to human health. Due to its complex structure and dual cofactor forms, Cbl undergoes a complicated series of absorptive and processing steps before serving as cofactor for the enzymes methylmalonyl‐CoA mutase and methionine synthase. Methylmalonyl‐CoA mutase is required for the catabolism of certain (branched‐chain) amino acids into an anaplerotic substrate in the mitochondrion, and dysfunction of the enzyme itself or in production of its cofactor adenosyl‐Cbl result in an inability to successfully undergo protein catabolism with concomitant mitochondrial energy disruption. Methionine synthase catalyzes the methyl‐Cbl dependent (re)methylation of homocysteine to methionine within the methionine cycle; a reaction required to produce this essential amino acid and generate S‐adenosylmethionine, the most important cellular methyl‐donor. Disruption of methionine synthase has wide‐ranging implications for all methylation‐dependent reactions, including epigenetic modification, but also for the intracellular folate pathway, since methionine synthase uses 5‐methyltetrahydrofolate as a one‐carbon donor. Folate‐bound one‐carbon units are also required for deoxythymidine monophosphate and de novo purine synthesis; therefore, the flow of single carbon units to each of these pathways must be regulated based on cellular needs. This review provides an overview on Cbl metabolism with a brief description of absorption and intracellular metabolic pathways. It also provides a description of folate‐mediated one‐carbon metabolism and its intersection with Cbl at the methionine cycle. Finally, a summary of recent advances in understanding of how both pathways are regulated is presented.
A simple and efficient automated cGMP‐compliant radiosynthesis of [11C]metomidate using solid phase extraction cartridge purification
Authors: Kovac Mitja , Miklovicz Tunde , Li Lei , Russell Joseph , Canales Candela Roberto , Aigbirhio Franklin , Boros Istvan 
Published: January 2019

[11C]metomidate ([11C]MTO) is a radiotracer widely used to detect disorders of adrenocortical origin by positron emission tomography (PET) imaging. [11C]MTO PET/computed tomography (PET/CT) is considered a sensitive and specific noninvasive alternative to adrenal vein sampling (AVS) in the management of primary hyperaldosteronism (PHA). Herein, we report a reliable automated procedure for the routine manufacturing of [11C]MTO in current good manufacturing practice (cGMP) conditions on the commercial Synthra MeIPlus Loop Vessel synthesizer. The method is based on a combination of the captive‐solvent 11C‐methylation of the carboxylate salt 1b of the MTO precursor 1a followed by solid phase extraction (SPE) cartridge purification methodology, which substitutes HPLC purification of the crude reaction mixture. Starting from 45 GBq [11C]CO2 at the end of bombardment (EOB), 3 GBq of pure [11C]MTO was produced in 18 minutes with 12% decay corrected radiochemical yield (RCY) at the end of synthesis (EOS) and with the modest molar activity of 13 GBq/μmol at the time of application. Each dose produced met all established quality control (QC) criteria. The method can easily be implemented into other commercial automated radiosynthesizers for manufacturing carbon‐11 labeled radiotracers.
Screening for Posttraumatic Stress Disorder in Refugees: Comparison of the Diagnostic Efficiency of Two Self‐Rating Measures of Posttraumatic Stress Disorder
Authors: Wulfes Nele , del Pozo Melina Andrea , Buhr‐Riehm Brigitte , Heinrichs Nina , Kröger Christoph 
Published: January 2019

AbstractThere is a high prevalence of posttraumatic stress disorder (PTSD) in the refugee population. In order to identify affected individuals and offer targeted help, there is an urgent need for easily understandable, reliable, valid, and efficient screening measures. The aim of the present study was to compare the diagnostic efficiency of the Process of Recognition and Orientation of Torture Victims in European Countries to Facilitate Care and Treatment (PROTECT) questionnaire (PQ) to that of the eight‐item short‐form Posttraumatic Diagnostic Scale (PDS‐8) and the Patient Health Questionnaire (PHQ‐9). Using structured clinical interviews, the prevalence rates of PTSD and major depression episode (MDE) were assessed in a refugee sample (N = 118), and receiver operating characteristic analyses were determined and compared. Of participants in the sample, 29.7%, 95% CI [22.0%, 38.5%], were diagnosed with PTSD and 33.1%, 95% CI [24.4%, 41.9%], were diagnosed with MDE. The area under the curve (AUC) for all measures was moderate, AUCs = 0.79–0.86; hence, measures did not differ in terms of their discriminatory abilities. Using the favored cutoff points, sensitivity and specificity were 80–97% and 60–70%, respectively. In terms of their discriminatory abilities, none of the investigated measures can be favored more than the others. Thus, for detection of these two disorders, the shorter PQ could be more efficient. Because the high co‐occurrence of PTSD and MDE might limit the explanatory power of results in the present study, the findings should be cross‐validated in the future.
Exploring Contextual Trauma in Cambodia: A Sociointerpersonal Perspective on Posttraumatic Stress Disorder
Authors: Armes Stephanie E. , Seponski Desiree M. , Kao Sovandara , Khann Sareth , Lahar Cindy J. , Bryant Chalandra M. , Bride Brian E. , Wickrama Kanudra S. , Bunnak Poch , Schunert Tanja 
Published: January 2019

AbstractTrauma literature has proposed multiple theories of trauma development, maintenance, and transmission, which has led to a lack of clarity surrounding trauma in individuals, families, and communities. We investigated the impact of community‐level trauma experiences on individual posttraumatic stress disorder (PTSD) symptoms using a sociointerpersonal model of PTSD (Maerker & Horn, 2013). A nationally representative sample (N = 2, 690) of Cambodian households across all regions of the country was surveyed regarding individual trauma experiences during and after the Khmer Rouge regime, symptoms of PTSD, and current stressors. Individual experiences of war trauma and current stressors were aggregated based on the district in which each individual lived. District mean and individual war trauma and current stressors were included in a multilevel model as predictors of individual levels of PTSD. Findings indicated that mean trauma experiences, β = .05, p < .001, and current stressors, β = .10, p < .001, in the district in which individuals live were positively and significantly associated with their individual PTSD symptoms. Individual war trauma, β = .02, p < .001, and current stressors, β = .08, p < .001, were also positively and significantly associated with individual PTSD symptoms. District trauma experiences accounted for 7% of the variance in individual PTSD symptoms, R2Level 1 = .21, R2Level 2 = .80. Additionally, current stressors at both the individual and district levels had a greater impact on individual PTSD symptoms than war trauma at either level of the model. Implications for policy and intervention are presented.
Potential Utility of Contrast‐Enhanced Ultrasound in the Preoperative Evaluation of Primary Hyperparathyroidism
Authors: Parra Ramírez Paola , Santiago Hernando Antonio , Barquiel Alcalá Beatriz , Martín Rojas‐Marcos Patricia , Lisbona Catalán Arturo , Álvarez Escolá Cristina 
Published: January 2019

ObjectivesWe aimed to compare the effectiveness of contrast‐enhanced ultrasound (CEUS), technetium Tc 99m methoxyisobutylisonitrile (99mTc‐MIBI) single‐photon emission computed tomographic (SPECT) scintigraphy, and high‐resolution ultrasound (US) in the detection of a pathologic parathyroid gland in patients with primary hyperparathyroidism (pHPT).MethodsTwenty‐nine consecutive patients with pHPT were prospectively enrolled and underwent preoperative imaging with 99mTc‐MIBI SPECT scintigraphy, high‐resolution US, and CEUS and subsequent parathyroidectomy. Contrast‐enhanced US examinations were performed by an experienced examiner who was blinded to the results of scintigraphy and high‐resolution US. The diagnostic performance of all of the imaging tests was analyzed in comparison with the pathologic anatomic findings. All investigations were performed at La Paz University Hospital.ResultsIn the 29 patients (22 female and 7 male), a total of 31 parathyroid adenomas were detected: single lesions in 27 patients and a double lesion in 2 patients. Contrast‐enhanced US revealed sensitivity of 66.7% (95% confidence interval [CI], 46%–82.7%) for detection of single adenomas in comparison with 77.8 % (95% CI, 57.3%–90.6) for 99mTc‐MIBI SPECT scintigraphy and 51.8% (95% CI, 32.3%–70.8%) for high‐resolution US (P = .100). With CEUS, double adenomas could be detected in both cases (sensitivity, 100%); however, scintigraphy and high‐resolution US did not detect any cases of double adenomas. In addition, CEUS allowed the differentiation of lymphatic nodes from parathyroid glands in 2 patients. No side effects were observed for CEUS.ConclusionsIn our study, CEUS facilitated the detection and diagnosis of double adenomas compared with high‐resolution US and 99mTc‐MIBI SPECT scintigraphy. Additionally, CEUS was useful in the differentiation between parathyroid adenomas and lymph nodes.
Otolaryngology boot camps: Current landscape and future directions
Authors: Dean Kelly M. , DeMason Christine E. , Choi Sukgi S. , Malloy Kelly M. , Malekzadeh Sonya 
Published: January 2019

ObjectivesSimulation‐based boot camps have gained popularity over the past few years, with some surgical specialties implementing mandatory national boot camps. However, there is no consensus in otolaryngology on boot camp timing, learner level, or curriculum. The purpose of this study is to examine the current landscape and gather opinions regarding future curriculum and standardization of boot camps in otolaryngology.MethodsA survey was developed to examine current resident participation and boot camp content while also seeking opinions regarding improving boot camp enrollment and standardizing curriculum. A cross‐sectional survey of all otolaryngology residency program directors in the United States and Puerto Rico was performed via SurveyMonkey. Responses were collected anonymously, and results were analyzed by descriptive statistical analysis.ResultsOf the 45% (48 of 106) who responded, 76.6% reported their residents participate in boot camps. The most common skills taught were basic suturing and airway management skills. The majority (95%) was likely to send residents to a local boot camp, with 56% favoring early postgraduate year (PGY)‐1 participation and 42% favoring a 1‐day boot camp. Subsidized expenses, improved regional access, and supplementary boot camp information would help the program director in their decision to send residents to boot camp. Only 32% felt boot camps should be standardized, and 27% felt they should be mandatory.ConclusionMany otolaryngology residency programs participate in boot camps. Additional data on the benefits of boot camps, improved access, and reduced financial burden may improve participation. Further discussion of ideal timing, PGY level, and standardized curriculum should occur in conjunction with the otolaryngology academic societies and oversight from accreditation and certifying bodies.Level of EvidenceNA Laryngoscope, 129:2707–2712, 2019
Contrasting arsenic cycling in strongly and weakly stratified contaminated lakes: Evidence for temperature control on sediment–water arsenic fluxes
Authors: Barrett P. M. , Hull E. A. , Burkart K. , Hargrave O. , McLean J. , Taylor V. F. , Jackson B. P. , Gawel J. E. , Neumann R. B. 
Published: January 2019

AbstractArsenic contamination of lakebed sediments is widespread due to a range of human activities, including herbicide application, waste disposal, mining, and smelter operations. The threat to aquatic ecosystems and human health is dependent on the degree of mobilization from sediments into overlying water columns and exposure of aquatic organisms. We undertook a mechanistic investigation of arsenic cycling in two impacted lakes within the Puget Sound region, a shallow weakly stratified lake and a deep seasonally stratified lake, with similar levels of lakebed arsenic contamination. We found that the processes that cycle arsenic between sediments and the water column differed greatly in shallow and deep lakes. In the shallow lake, seasonal temperature increases at the lakebed surface resulted in high porewater arsenic concentrations that drove larger diffusive fluxes of arsenic across the sediment–water interface compared to the deep, stratified lake where the lakebed remained ~10°C cooler. Plankton in the shallow lake accumulated up to an order of magnitude more arsenic than plankton in the deep lake due to elevated aqueous arsenic concentrations in oxygenated waters and low phosphate : arsenate ratios in the shallow lake. As a result, strong arsenic mobilization from sediments in the shallow lake was countered by large arsenic sedimentation rates out of the water column driven by plankton settling.
Cationic Poly([R]‐3‐hydroxybutyrate) Copolymers as Antimicrobial Agents
Authors: Liow Sing Shy , Chee Pei Lin , Owh Cally , Zhang Kangyi , Zhou Yubin , Gao Feng , Lakshminarayanan Rajamani , Loh Xian Jun 
Published: January 2019

AbstractPoly([R]‐3‐hydroxybutyrate) (PHB), a natural biodegradable polyester, has attracted much attention as a new biomaterial because of its sustainability and good biocompatibility. In this study, it is discovered that PHB can be conveniently functionalized to obtain a number of platform chain architectures that may provide a wide range of functional copolymers. In a transesterification reaction, linear (di‐hydroxylated) and star shaped (tri‐ and tetra‐hydroxylated) PHB oligomers are synthesized, followed by copolymerization with 2‐(dimethylamino)ethyl methacrylate and quaternization with benzyl bromide to afford antimicrobial properties. The antimicrobial activities of the quaternary salts against clinically relevant pathogens on the interactions with outer and cytoplasmic membranes, lethal mechanisms, multipassage resistance, and synergy effect with antibiotics are investigated. Cationic PHB copolymers show effectiveness as antimicrobial agents, with minimum inhibitory concentration values 0.24–0.65 µm (or µmol dm−3) (or 32–128 µg mL−1) against Gram‐positive and Gram‐negative bacteria. Modifying the copolymer architectures into star shapes results in enhanced effectiveness to disrupt the membrane integrity. Synergistic effects are attained for all the quaternized PHB derivatives when they are used together with tobramycin. Multipassage resistance does not occur in both the linear and star derivatives against Gram‐negative bacteria after 20 passages.
Mutation analysis of common deafness genes among 1,201 patients with non‐syndromic hearing loss in Shanxi Province
Authors: Zhou Yongan , Li Chao , Li Min , Zhao Zhonghua , Tian Shuxiong , Xia Hou , Liu Peixian , Han Yaxin , Ren Ruirui , Chen Jianping , Jia Caihong , Guo Wei 
Published: January 2019

AbstractBackgroundHearing impairment is one of most frequent birth defects, which affects nearly 1 in every 1,000 live births. However, the molecular etiology of non‐syndromic deafness in China is not well studied. Here, we have investigated the presence of mutations in three genes commonly mutated in non‐syndromic deafness patients in Shanxi Province, which has the highest frequency of birth defects in China.MethodsIn total, 1,201 unrelated non‐syndromic deafness patients and 300 healthy individuals were enrolled. The hearing ability was confirmed by audiologic evaluation. Three major deafness‐related genes (GJB2, SLC26A4 (PDS), and mtDNA 12S rRNA) of all individuals enrolled were analyzed by Sanger sequencing.ResultsThe results showed that GJB2 mutations accounted for 21.23% (255/1,201) in the patient group, with c.235delC, a hotspot mutation, accounting for 10.99% (132/1,201). Moreover, 11 new GJB2 mutations were identified. SLC26A4 mutations accounted for 9.33% (112/1,201) in the patient group, with IVS7‐2A>G as the most prevalent mutation accounting for 4.75% (57/1,201). In addition, 15 patients (1.25%) were found to carry mtDNA 12S rRNA c.1555A>G mutation, while only two cases had the mtDNA 12S rRNA c.1494C>T.ConclusionIn our research, it was found that c.235delC in GJB2 and c.919‐2A>G (IVS7‐2A>G) in SLC26A4 were the highest frequency pathogenic variants in Shanxi Province. Taken together, our data will enrich the database of deafness mutations and will help clinical diagnosis, treatment, and genetic counseling of hearing impairment.
SAR raw data simulation for multiple‐input multiple‐output video synthetic aperture radar using beat frequency division frequency modulated continuous wave
Authors: Kim Seok , Ka Min‐Ho 
Published: January 2019

AbstractSynthetic aperture radar (SAR) raw data simulation, operating under various scenarios, and realistic environments, are necessary for analyzing and verifying the performance aspects of SAR systems and the various algorithms used in them. In this article, we propose a method to simulate the raw data generated by multiple‐input multiple‐output video synthetic aperture radar (MIMO ViSAR) from a speckled scene, using beat frequency division (BFD) frequency‐modulated continuous wave (FMCW). Using an optical image as a reflectivity map for a realistic scene, we first multiply a speckle noise with this image to generate a speckled reflectivity map. We then compute the two‐dimensional convolutions of a SAR point spread function of a MIMO ViSAR system with the speckled reflectivity map to generate a complex SAR image. Finally, the SAR raw data is generated through inverse processing of the MIMO ViSAR system. We use the synthesized raw data to reconstruct SAR images, based on our previously proposed MIMO ViSAR signal‐processing algorithm, to demonstrate and verify the effectiveness of the proposed method.
Use of dielectric padding to eliminate low convective field artifact in cr‐MREPT conductivity images
Authors: Yildiz Gulsah , Ider Yusuf Ziya 
Published: January 2019

PurposeConvection–reaction equation‐based magnetic resonance electrical properties tomography (cr‐MREPT) provides conductivity images that are boundary artifact‐free and robust against noise. However, these images suffer from the low convective field (LCF) artifact. We propose to use dielectric pads to alter the transmit magnetic field (B1+), shift the LCF region, and eliminate the LCF artifact.MethodsComputer simulations were conducted to analyze the effects of pad electrical properties, pad thickness, pad height, arc angle, and thickness of the pad–object gap. In 3T MR experiments, water pads and BaTiO3 pads were used with agar–saline phantoms. Two data sets (e.g., with the pad located on the left or on the right of the object [phantom]) were acquired, and the corresponding linear systems were simultaneously solved to get LCF artifact‐free conductivity images.ResultsA pad needed to have 180° arc angle and the same height with the phantom for maximum benefit. Increasing the pad thickness and/or the relative permittivity of the pad increased the LCF shift, whereas excessive amounts of these parameters caused errors in conductivity reconstructions because the effect of neglected Bz terms became noticeable. Conductivity of the pad, on the other hand, had minimal effect on elimination of the LCF artifact. Combining 2 data sets (i.e., with 2 different dielectric pad positions) resulted in more accurate conductivity maps (low L2‐errors) as opposed to no pad or single pad cases in experiments and simulations.ConclusionsUsing the proposed technique, LCF artifact is significantly removed, and the reconstructed conductivity values are improved.
Optimization of steady‐state pulsed CEST imaging for amide proton transfer at 3T MRI
Authors: Kim Byungjai , So Seohee , Park Hyunwook 
Published: January 2019

PurposeTo optimize a steady‐state imaging sequence for maximizing the amide proton transfer effects in pulsed‐CEST (pCEST) imaging.MethodThe steady‐state pCEST (SS‐pCEST) sequence is a fast CEST imaging scheme that applies repetitive short RF pulses for generating CEST and acquiring MR imaging signal alternately. To maximize the obtainable amide proton transfer effects, the SS‐pCEST scheme is analyzed and optimized with respect to not only the imaging parameters but also the imaging schemes of the signal acquisition part. Three imaging parameters such as the flip angle and RF power for saturation and the flip angle for imaging are selected as factors affecting the obtainable CEST effects; and 2 imaging schemes, namely, SSFP and spoiled gradient echo sequences, are analyzed and compared for numerical simulations and MRI experiments at 3 tesla.ResultsSS‐pCEST combined with SSFP could provide higher amide proton transfer effects than that with spoiled gradient echo. Furthermore, in the proposed SS‐pCEST imaging with SSFP, 3 imaging parameters can be independently optimized so that the optimization complexities can be reduced.ConclusionWe optimized the SS‐pCEST imaging method with SSFP to maximize the amide proton transfer effects. In addition, our analysis showed the SSFP sequence was more efficient than the spoiled gradient echo sequence for SS‐pCEST imaging.
Impact of socioeconomic markers on parents' retention of pediatric oncology home care education: A pilot study
Authors: Hentea Cristiana , Downs Stephen M. , Tucker Edmonds Brownsyne , Vik Terry , Wiehe Sarah E. , Cheng Erika R. 
Published: January 2019

AbstractLittle is known about the extent to which parents retain the education on how to manage home medical emergencies. We sought to describe retention of pediatric oncology home care education (POHCE) in a cohort of 24 parents of newly diagnosed children with cancer and investigate sociodemographic disparities in this retention. We measured retention using a vignette‐based survey instrument. The mean score was 4 (range 0–6, SD = 1.6) and parents with high school only education and those with limited cancer health literacy scored lowest (2.5 and 2.8, respectively). Future POHCE interventions can focus on parents’ literacy and education levels as predictors to tailor alternative education strategies.