bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancing extracellular protein production in Escherichia coli by deleting the d‐alanyl‐d‐alanine carboxypeptidase gene dacC
Authors: Hu Jinyuan , Lu Xiao , Wang Haokun , Wang Fuxiang , Zhao Yuan , Shen Wei , Yang Haiquan , Chen Xianzhong 
Published: January 2019

Abstractd‐Alanyl‐d‐alanine carboxypeptidase DacC is important for synthesis and stabilization of the peptidoglycan layer of Escherichia coli. In this work, dacC of E. coli BL21 (DE3) was successfully deleted, and the effects of this deletion on extracellular protein production in E. coli were investigated. The extracellular activities and fluorescence value of recombinant amylase, green fluorescent protein, and α‐galactosidase of the deletion mutants were increased by 82.3, 29.1, and 37.7%, respectively, compared with that of control cells. The outer membrane permeability and intracellular soluble peptidoglycan accumulation of deletion mutant were also enhanced compared with those of control cells, respectively. Based on fluorescence‐assisted cell sorting analyses, we found that the morphology of the E. coli deletion mutant cells was altered compared with that of control cells. Local transparent bulges in the poles of the E. coli mutant with deletion of the dacC gene were found by transmission electron microscopy analysis. These bulges in the poles could explain the improvement in the production of extracellular protein by the E. coli mutant with deletion of the dacC gene. These findings provide important insights into the extracellular production of proteins using E. coli as microbial cell factories.
Neurobiological signature of intimacy in anorexia nervosa
Authors: Maier Simon , Spiegelberg Julia , van Zutphen Linda , Zeeck Almut , Tebartz van Elst Ludger , Hartmann Armin , Holovics Lukas , Reinert Elke , Sandholz Angelika , Lahmann Claas , Domschke Katharina , Glauche Volkmar , Tüscher Oliver , Joos Andreas A.B. 
Published: January 2019

AbstractBackgroundIntimacy and psychosexual development represent core problems of anorexia nervosa (AN). Experiential and neurobiological evidence however is scarce.Material and methodsThirty‐one female AN patients were compared with 35 non‐patients (NP) and 22 recovered participants (REC) by using functional magnetic resonance imaging. Participants viewed pictures of couples in intimate relationships and control stimuli.ResultsAN patients experienced intimate stimuli with lower valence and dominance. AN showed decreased activation of parietal cortices. NP decreased the prefrontal cortex response, which AN patients did not. REC participants did not differ from NP on a behavioural level, though with regard to the neural signature.DiscussionParietal cortices are related to processing of erotic themes, which seems to be deficient in AN. Dysfunction of prefrontal cortices likely mirrors dysfunctional control in AN. The neural signature does not seem to be state‐related considering results of REC.
Model-based exploration of the variability in lake trout (Salvelinus namaycush) bioaccumulation factors: The influence of physiology and trophic relationships
Authors: Baskaran Sivani , Armitage James M. , Wania Frank 
Published: January 2019

Abstract

Because dietary consumption of fish is often a major vector of human exposure to persistent organic pollutants (POPs), much effort is directed toward a quantitative understanding of fish bioaccumulation using mechanistic models. However, many such models fail to explicitly consider how uptake and loss rate constants relate to fish physiology. We calculated the bioaccumulation factors (BAFs) of hypothetical POPs, with octanol–water partition coefficients ranging from 104.5 to 108.5, in lake trout (Salvelinus namaycush) with a food-web bioaccumulation model that uses bioenergetics to ensure that physiological parameters applied to a species are internally consistent. We modeled fish in 6 Canadian lakes (Great Slave Lake, Lake Ontario, Source Lake, Happy Isle Lake, Lake Opeongo, and Lake Memphremagog) to identify the factors that cause the BAFs of differently sized lake trout to vary between and within lakes. When comparing differently sized lake trout within a lake, larger fish tend to have the highest BAF because they allocate less energy toward growth than smaller fish and have higher activity levels. When comparing fish from different lakes, the model finds that diet composition and prey energy density become important in determining the BAF, in addition to activity and the amount of total energy allocated to growth. Environ Toxicol Chem 2019;38:831–840. © 2019 SETAC
Abstract
A bioaccumulation model accounting for bioenergetic constraints on the rates of food consumption, respiration, and growth is used to explain differences in the bioaccumulation factor of persistent organic contaminants between differently sized trout in the same lake and between similarly sized trout from different lakes. BAF = bioaccumulation factor; KOW = octanol–water partitioning coefficient. Source: Knepp, Timothy, US Fish and Wildlife Service, public domain, https://commons.wikimedia.org/wiki/File:Lake_trout_fishes_salvelinus_namaycush.jpg
A modified sequential Monte Carlo procedure for the efficient recursive estimation of extreme quantiles
Authors: Neslihanoglu Serdar , Date Paresh 
Published: January 2019

AbstractMany applications in science involve finding estimates of unobserved variables from observed data, by combining model predictions with observations. The sequential Monte Carlo (SMC) is a well‐established technique for estimating the distribution of unobserved variables that are conditional on current observations. While the SMC is very successful at estimating the first central moments, estimating the extreme quantiles of a distribution via the current SMC methods is computationally very expensive. The purpose of this paper is to develop a new framework using probability distortion. We use an SMC with distorted weights in order to make computationally efficient inferences about tail probabilities of future interest rates using the Cox–Ingersoll–Ross (CIR) model, as well as with an observed yield curve. We show that the proposed method yields acceptable estimates about tail quantiles at a fraction of the computational cost of the full Monte Carlo.
Intermittent theta burst stimulation over right somatosensory larynx cortex enhances vocal pitch‐regulation in nonsingers
Authors: Finkel Sebastian , Veit Ralf , Lotze Martin , Friberg Anders , Vuust Peter , Soekadar Surjo , Birbaumer Niels , Kleber Boris 
Published: January 2019

AbstractWhile the significance of auditory cortical regions for the development and maintenance of speech motor coordination is well established, the contribution of somatosensory brain areas to learned vocalizations such as singing is less well understood. To address these mechanisms, we applied intermittent theta burst stimulation (iTBS), a facilitatory repetitive transcranial magnetic stimulation (rTMS) protocol, over right somatosensory larynx cortex (S1) and a nonvocal dorsal S1 control area in participants without singing experience. A pitch‐matching singing task was performed before and after iTBS to assess corresponding effects on vocal pitch regulation. When participants could monitor auditory feedback from their own voice during singing (Experiment I), no difference in pitch‐matching performance was found between iTBS sessions. However, when auditory feedback was masked with noise (Experiment II), only larynx‐S1 iTBS enhanced pitch accuracy (50–250 ms after sound onset) and pitch stability (>250 ms after sound onset until the end). Results indicate that somatosensory feedback plays a dominant role in vocal pitch regulation when acoustic feedback is masked. The acoustic changes moreover suggest that right larynx‐S1 stimulation affected the preparation and involuntary regulation of vocal pitch accuracy, and that kinesthetic‐proprioceptive processes play a role in the voluntary control of pitch stability in nonsingers. Together, these data provide evidence for a causal involvement of right larynx‐S1 in vocal pitch regulation during singing.
Dimension of the space generated by Steiner systems
Authors: Ghodrati Amir Hossein 
Published: January 2019

AbstractTo every Steiner system with parameters on and blocks , we can assign its characteristic vector , which is a ‐vector whose entries are indexed by the ‐subsets of such that for each ‐subset of if and only if . In this paper, we show that the dimension of the vector space generated by all of the characteristic vectors of Steiner systems with parameters is , provided that and there is at least one such system.
Human trisomy 21 fibroblasts rescue methotrexate toxic effect after treatment with 5‐methyl‐tetrahydrofolate and 5‐formyl‐tetrahydrofolate
Authors: Vitale Lorenza , Serpieri Valentina , Lauriola Mattia , Piovesan Allison , Antonaros Francesca , Cicchini Elena , Locatelli Chiara , Cocchi Guido , Strippoli Pierluigi , Caracausi Maria 
Published: January 2019

AbstractTrisomy 21 causes Down syndrome (DS), the most common human genetic disorder and the leading genetic cause of intellectual disability. The alteration of one‐carbon metabolism was described as the possible metabolic cause of the intellectual disability development in subjects with DS. One of the biochemical pathways involved in the one‐carbon group transfer is the folate cycle. The cytotoxic drug methotrexate (MTX) is a folic acid (FA) analogue which inhibits the activity of dihydrofolate reductase enzyme involved in the one‐carbon metabolic cycle. Trisomy 21 cells are more sensitive to the MTX effect than euploid cells, and in 1986 Jérôme Lejeune and Coll. demonstrated that MTX was twice as toxic in trisomy 21 lymphocytes than in control cells. In the present work, the rescue effect on MTX toxicity mediated by FA and some of its derivatives, tetrahydrofolate (THF), 5‐formyl‐THF, and 5‐methyl‐THF, in both normal and trisomy 21 skin fibroblast cells, was evaluated. A statistically significant rescue effect was obtained by 5‐formyl‐THF, 5‐methyl‐THF, and their combination, administered together with MTX. In conclusion, trisomy 21 fibroblast cell lines showed a good response to the rescue effects of 5‐formyl‐THF and 5‐methyl‐THF on the MTX toxicity almost as normal cell lines.
BRG1 is a prognostic indicator and a potential therapeutic target for prostate cancer
Authors: Muthuswami Rohini , Bailey LeeAnn , Rakesh Radhakrishnan , Imbalzano Anthony N. , Nickerson Jeffrey A. , Hockensmith Joel W. 
Published: January 2019

AbstractBrahma‐related gene 1 (BRG1) is one of two mutually exclusive ATPases that function as the catalytic subunit of human SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling enzymes. BRG1 has been identified as a tumor suppressor in some cancer types but has been shown to be expressed at elevated levels, relative to normal tissue, in other cancers. Using TCGA (The Cancer Genome Atlas) prostate cancer database, we determined that BRG1 mRNA and protein expression is elevated in prostate tumors relative to normal prostate tissue. Only 3 of 491 (0.6%) sequenced tumors showed amplification of the locus or mutation in the protein coding sequence, arguing against the idea that elevated expression due to amplification or expression of a mutant BRG1 protein is associated with prostate cancer. Kaplan‐Meier survival curves showed that BRG1 expression in prostate tumors inversely correlated with survival. However, BRG1 expression did not correlate with Gleason score/International Society of Urological Pathology (ISUP) Grade Group, indicating it is an independent predictor of tumor progression/patient outcome. To experimentally assess BRG1 as a possible therapeutic target, we treated prostate cancer cells with a biologic inhibitor called ADAADi (active DNA‐dependent ATPase A Domain inhibitor) that targets the activity of the SNF2 family of ATPases in biochemical assays but showed specificity for BRG1 in prior tissue culture experiments. The inhibitor decreased prostate cancer cell proliferation and induced apoptosis. When directly injected into xenografts established by injection of prostate cancer cells in mouse flanks, the inhibitor decreased tumor growth and increased survival. These results indicate the efficacy of pursuing BRG1 as both an indicator of patient outcome and as a therapeutic target.
A comprehensive review of therapeutic targets that induce microglia/macrophage‐mediated hematoma resolution after germinal matrix hemorrhage
Authors: Flores Jerry J. , Klebe Damon , Tang Jiping , Zhang John H. 
Published: January 2019

AbstractCurrently, there is no effective treatment for germinal matrix hemorrhage and intraventricular hemorrhage (GMH‐IVH), a common and often fatal stroke subtype in premature infants. Secondary brain injury after GMH‐IVH is known to involve blood clots that contribute to inflammation and neurological deficits. Furthermore, the subsequent blood clots disrupt normal cerebrospinal fluid circulation and absorption after GMH‐IVH, contributing to posthemorrhagic hydrocephalus (PHH). Clinically, GMH‐IVH severity is graded on a I to IV scale: Grade I is confined to the germinal matrix, grade II includes intraventricular hemorrhage, grade III includes intraventricular hemorrhage with extension into dilated ventricles, and grade IV includes intraventricular hemorrhage with extension into dilated ventricles as well as parenchymal hemorrhaging. GMH‐IVH hematoma volume is the best prognostic indicator, where patients with higher grades have worsened outcomes. Various preclinical studies have shown that rapid hematoma resolution quickly ameliorates inflammation and improves neurological outcomes. Current experimental evidence identifies alternatively activated microglia as playing a pivotal role in hematoma clearance. In this review, we discuss the pathophysiology of GMH‐IVH in the development of PHH, microglia/macrophage's role in the neonatal CNS, and established/potential therapeutic targets that enhance M2 microglia/macrophage phagocytosis of blood clots after GMH‐IVH.
A LC‐MS/MS method for simultaneous determination of seven alkaloids in rat plasma after oral administration of Phellodendri chinensis cortex extract and its application to a pharmacokinetic study
Authors: Wang Zhibin , Song Mengmeng , Cui Binbin , Ren Yixuan , Zhu Wenbo , Yang Bingyou , Kuang Haixue 
Published: January 2019

AbstractA sensitive and rapid liquid chromatography with tandem mass spectrometry method has been developed for simultaneous determination of berberine (I), jateorhizine (II), palmatine (III), tetrahydropalmatine (IV), phellodendrine (V), protopine (VI) and columbamine (VII) in rat plasma after oral administration of Phellodendri chinensis cortex extraction. The plasmas were extracted by liquid‐liquid extraction. The tandem mass spectrometric detection was performed in the multiple reaction monitoring mode in the positive ionization. The intra‐ and interday precisions and accuracies were in range from −12.18 to 13.21%. Mean absolute recoveries of all analytes and internal standard were between 78.6 and 98.9%. The seven alkaloids were proven to be stable during sample storage and analysis procedures. The established method was validated and successfully applied to pharmacokinetics study in rat plasma after oral administration of Phellodendri chinensis cortex extract. The t1/2 of palmatine, columbamine, pellodendrine, berberine, tetrahydropalmaine, jatrorrhizine, and protopine were 5.16, 5.96, 7.18, 19.84, 6.28, 7.08, 6.90 h, respectively. The seven compounds could be rapidly absorbed into blood (time for maximal concentration, 1.80–1.93 h). This study could establish a foundation for further research of Phellodendri chinensis cortex and might provide more useful information to guide the clinical usage.
The role of elective neck dissection in patients with adenoid cystic carcinoma of the head and neck
Authors: Xiao Roy , Sethi Rosh K.V. , Feng Allen L. , Fontanarosa Joel B. , Deschler Daniel G. 
Published: January 2019

ObjectiveTo investigate the frequency and outcomes of elective neck dissection (END) for adenoid cystic carcinoma (ACC) of the head and neck.MethodsThe National Cancer Database was queried for a cohort study of patients with ACC of the major salivary glands, nasal cavity/nasopharynx, hard/soft palate, tongue, floor of mouth, larynx, and oral cavity who underwent primary surgical resection from 2004 to 2014. Multivariable logistic regression was used to identify predictors of END and occult nodal metastasis. Overall survival (OS) was estimated using the Kaplan‐Meier method and modeled with Cox proportional hazards regression.ResultsAmong 2,807 patients with ACC treated surgically, 636 (22.7%) underwent END. Patients with ACC of the salivary glands and tongue most frequently underwent END; patients with hard/soft palate (odds ratio [OR] 0.06, P < 0.001) and nasal cavity/nasopharynx (OR 0.05, P < 0.001) ACC rarely underwent END compared to patients with major salivary gland cancer. Increasing tumor (T) stage (T4 vs. T1, OR 3.02, P < 0.001) was associated with END. Patients with advanced T3 to T4 ACC of the major salivary glands demonstrated extended OS associated with END (5‐year OS 78.1% vs. 70.4%, P = 0.041) on Kaplan‐Meier analysis and with END with adjuvant radiation therapy (hazard ratio 0.55, P = 0.027) using Cox proportional hazards regression. Elective neck dissection for T4 ACC of the salivary glands (21.3%) and tongue (25.5%) most consistently revealed occult nodal metastasis.ConclusionElective neck dissection for ACC of the major salivary glands or tongue is most likely to reveal occult nodal metastasis. Elective neck dissection is associated with extended OS for advanced‐stage ACC of the major salivary glands.Level of EvidenceNALaryngoscope, 129:2094–2104, 2019
Laryngeal force sensor metrics are predictive of increased perioperative narcotic requirements
Authors: Feng Allen L. , Ciaramella Alex , Naunheim Matthew R. , Gadkaree Shekhar K. , Fat Iuliu , Song Phillip C. 
Published: January 2019

Objectives/HypothesisTo determine the relationship between force metrics measured by the laryngeal force sensor (LFS) during suspension microlaryngoscopy (SML) and perioperative narcotic requirements.Study DesignProspective observational study.MethodsCompressive tissue forces were recorded during SML using the LFS and correlated with postoperative narcotic requirements in the postanesthesia care unit (PACU) at an academic tertiary center. Patients were prospectively enrolled and had force metrics recorded throughout each procedure including maximum force, average force, suspension time, and total impulse. Narcotic administration in the intraoperative period and PACU were also recorded and converted into intravenous morphine equivalents (ME). Surgeons were blinded to the force recordings during surgery to prevent operator bias.ResultsEighty‐two patients completed the study. Of these patients, the mean perioperative ME requirement was 16.96 mg (range, 0.15–79.82 mg). Univariate analysis demonstrated a positive correlation between perioperative narcotic requirements and total suspension time (P < .001) as well as total impulse (P = .007). A positive correlation was also seen with maximum force, although not significantly. On multiple linear regression, total suspension time was a significant predictive variable for perioperative narcotic use, with a marginal incremental increase of 0.273 mg of ME per minute of total suspension time (0.273 mg/min, 95% confidence interval: 0.040‐0.507 mg/min, P = .022).ConclusionsIntraoperative force metrics including total suspension time are predictive of increased perioperative narcotic requirement after SML. Total impulse during SML may also correlate with increased perioperative narcotic requirements.Level of Evidence2 Laryngoscope, 129:2563–2567, 2019
Existence Conditions of High‐k Modes in Finite Hyperbolic Metamaterials
Authors: Mahmoodi Maryam , Tavassoli Seyed Hassan , Takayama Osamu , Sukham Johneph , Malureanu Radu , Lavrinenko Andrei V. 
Published: January 2019

AbstractThe capability to support optical waves with very large wave vectors (high‐k) is one of the principle features of hyperbolic metamaterials (HMMs). These waves play the key role in HMM applications such as imaging and lifetime engineering. Effective medium approximation (EMA) as widely used analytical method to predict HMMs behavior, has shortcomings in calculating high‐k modes of practical structures. EMA is applicable to a subwavelength unit cell of implicitly infinite periodic structures. Using conventional EMA, in the present paper, boundary effects and spatial dispersion are taken into consideration to properly compute the high‐k modes of finite‐thickness multilayer HMMs. Applying nonlocal homogenization to stacks of alternating metal‐dielectric layers, the corresponding effective medium is examined as a high‐k waveguide sandwiched between the substrate and an ambient superstrate. The developed theory enables us to recognize two types of bulk waves coined as short‐range and long‐range propagating modes. Number of such modes as well as their cutoff conditions are quantified for the first time. Validity of the developed theory is verified both numerically by rigorous simulations of the multilayer structures with the transfer matrix method and experimentally by optical characterization of the HMMs in infrared regime.
Clinical application of single‐molecule optical mapping to a multigeneration FSHD1 pedigree
Authors: Zhang Qian , Xu Xueqin , Ding Lirong , Li Huanzheng , Xu Chengyang , Gong Yuyan , Liu Ying , Mu Ting , Leigh Don , Cram David S. , Tang Shaohua 
Published: January 2019

AbstractIntroductionFacioscapulohumeral muscular dystrophy 1 (FSHD1) is a relatively common autosomal dominant adult muscular dystrophy with variable disease penetrance. The disease is caused by shortening of a D4Z4 repeat array located near the telomere of chromosome 4 at 4q35. This causes activation of a dormant gene DUX4, permitting aberrant DUX4 expression which is toxic to muscles. Molecular diagnosis of FSHD1 by Southern blot hybridization or FISH combing is difficult and time consuming, requiring specialist laboratories. As an alternative, we apply a novel approach for the diagnosis of FSHD1 utilizing single‐molecule optical mapping (SMOM).MethodsLong DNA molecules with BssS1 enzyme marking were subjected to SMOM on the Bionano Genomics platform to determine the number of D4Z4 repeats. Southern blot and molecular combing were used to confirm the FSHD1 haplotypes.ResultsIn a study of a five‐generation FSHD1 pedigree, SMOM correctly diagnosed the disease and normal haplotypes, identifying the founder 4qA disease allele as having 4 D4Z4 repeat units. Southern blot and molecular combing analysis confirmed the SMOM results for the 4qA disease and 4qB nondisease alleles.ConclusionBased on our findings, we propose that SMOM is a reliable and accurate technique suitable for the molecular diagnosis of FSHD1.
Modified montmorillonite combined with intumescent flame retardants on the flame retardancy and thermal stability properties of unsaturated polyester resins
Authors: Yu Yuan , Chen Zhiquan , Zhang Qingwu , Jiang Mengwei , Zhong Zhihao , Chen Tingting , Jiang Juncheng 
Published: January 2019

Modified montmorillonite‐containing phytic acid (PA‐MMT) has been prepared by acid treatment and then introduced into unsaturated polyester resin (UPR) with an intumescent flame retardant (IFRs). The flame retardancy and thermal degradation of UPR/IFRs/PA‐MMT were evaluated by a limiting oxygen index (LOI) test, a vertical burning test (UL‐94), a thermogravimetric analysis (TGA), and a cone calorimeter test (CCT). Besides, the mechanical properties were studied by a universal testing machine. The LOI value of UPR/IFRs/PA‐MMT composites was increased to 29.2%. The CCT results indicated that the incorporation of PA‐MMT and IFRs significantly improved the combustion behavior of UPR. The results of the mechanical properties indicated that 1.5 wt% loading of PA‐MMT in UPR/IFRs showed the highest improvement in flexural strength and tensile strength. The flame‐retardant mechanism of PA‐MMT/IFRs was examined and discussed based on the results of combustion behavior and char analysis.