bluuebunny/crossref_metadata_2025 huggingface dataset:
Perfusion‐based fluorescence imaging method delineates diverse organs and identifies multifocal tumors using generic near‐infrared molecular probes
Authors: Miller Jessica , Wang Steven T. , Orukari Inema , Prior Julie , Sudlow Gail , Su Xinming , Liang Kexian , Tang Rui , Hillman Elizabeth M.C. , Weilbaecher Katherine N. , Culver Joseph P. , Berezin Mikhail Y. , Achilefu Samuel
Published: December 2017

Rapid detection of multifocal cancer without the use of complex imaging schemes will improve treatment outcomes. In this study, dynamic fluorescence imaging was used to harness differences in the perfusion kinetics of near‐infrared (NIR) fluorescent dyes to visualize structural characteristics of different tissues. Using the hydrophobic nontumor‐selective NIR dye cypate, and the hydrophilic dye LS288, a high tumor‐to‐background contrast was achieved, allowing the delineation of diverse tissue types while maintaining short imaging times. By clustering tissue types with similar perfusion properties, the dynamic fluorescence imaging method identified secondary tumor locations when only the primary tumor position was known, with a respective sensitivity and specificity of 0.97 and 0.75 for cypate, and 0.85 and 0.81 for LS288. Histological analysis suggests that the vasculature in the connective tissue that directly surrounds the tumor was a major factor for tumor identification through perfusion imaging. Although the hydrophobic dye showed higher specificity than the hydrophilic probe, use of other dyes with different physical and biological properties could further improve the accuracy of the dynamic imaging platform to identify multifocal tumors for potential use in real‐time intraoperative procedures.
Aberrant methylation of mutL homolog 1 is associated with increased risk of non‐small cell lung cancer
Authors: Hu Haochang , Chen Xiaoying , Zhou Cong , Li Bin , Yang Yong , Ying Xiuru , Mao Yiyi , Zhang Yihan , Zhong Jie , Dai Jie , Yu Hang , Wu Boyi , Li Xiaodong , Wang Tiangong , Duan Shiwei
Published: December 2017

Background

Non‐small cell lung cancer (NSCLC) is a common malignant tumor. DNA hypermethylation in the promoter region has been served as a potential molecular marker for several tumors. The goal of the current study was to assess the diagnostic ability of mutL homolog 1 (MLH1) promoter methylation in NSCLC.

Methods

A total of 111 NSCLC patients’ paired tissue samples were obtained to explore the association between MLH1 promoter methylation and NSCLC by methylation‐specific polymerase chain reaction (MSP) method. Public databases including The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were used to verify our findings.

Results

Our results showed a significantly higher MLH1 methylation frequency in tumor tissue samples than their paired adjacent tissues (P = .008). ROC curve indicated that MLH1MSP assay was a sensitive but not a specific method in the diagnosis for NSCLC (sensitivity = 0.964, specificity = 0.135, AUC = 0.550). And the association between the methylation level and clinical characteristics has no statistical significance. TCGA cohort evinced a higher methylation probability in tumor group compared with nontumor group (the mean β value: −0.449 [−0.467, −0.437] vs −0.466 [−0.472, −0.437], P = .011), which was consistent with our results. Meanwhile, an inverse correlation between MLH1 methylation and MLH1 expression was detected in TCGA and GEO databases.

Conclusions

The MSP method for MLH1 methylation was a sensitive but not a specific diagnostic method for NSCLC.
Ozonation inactivation of Escherichia coli in aqueous solution over MgO nanocrystals: modelling and mechanism
Authors: Chen Jun , Xu Shuang , Yang Hai , Au Chaktong , Tian Shuanghong , Xiong Ya
Published: December 2017

BACKGROUND

This study aims to reveal the potential of using heterogeneous catalytic ozonation processes (HCOP) in water disinfection and provide a direction to tailor the catalytic activity by crystal facet engineering. Four kinds of MgO nanocrystals individually with exposure of (111), (200), (110) and (100) facets were prepared and used.

RESULTS

It is found that MgO functions as a bactericide as well as a catalyst for ozonation. The catalytic activity of MgO nanocrystals decreases in the order MgO(111) > MgO(200) > MgO(110) > MgO(100). The apparent first‐order inactivation rate (kap) fitted by the Hom model of MgO(111)/O3 is 2.56 min‐1, which is 32.0 and 3.5 times that of single ozonation and classic MgO(100)/O3. It is confirmed by scavenger studies that •OH mainly works in MgO(111)/O3 while more direct ozonation occurs in other cases. Some O2•− are also detected in the presence of MgO. With the attack of these reactive oxidation species, cell membranes were damaged and intracellular components were released, leading to the death of Escherichia coli.

CONCLUSION

These results indicate that HCOP is a promising technology for water disinfection, and crystal facet engineering is an effective strategy to enhance the catalytic performance. © 2017 Society of Chemical Industry
A novel food‐grade lactococcal expression system and its use for secretion and delivery of an oral vaccine antigen
Authors: Zhang Rongguang , Qiao Dan , Peng Xiaoyan , Duan Guangcai , Shi Qingfeng , Zhang Linghan , Wang Chen , Liang Wenjuan , Chen Shuaiyin , Fan Qingtang
Published: December 2017

BACKGROUND

Food‐grade bacterial expression systems are relatively rare, and increasing evidence indicates that subcellular location of antigens in bacterial vector vaccines may markedly affect the immune efficacy.

RESULTS

This study developed a novel food‐grade secretory expression system for heterologous protein production and oral vaccine delivery. Furthermore, by using the expression system, an engineered L. lactis strain secreting H. pylori UreB was constructed, and used to vaccinate SPF BALB/c mice. As results, the UreB expressed in L. lactis was detected in both cell lysates and culture supernatant of the engineered strain, constituting roughly 50% of the culture supernatant proteins, and recognized by mouse anti‐H. pylori sera. Oral vaccination with the engineered L. lactis produced a significantly elevated anti‐UreB serum antibody level in mice (P < 0.05).

CONCLUSION

These data show a novel food‐grade L. lactis secretory expression system, which may have distinct potential impact on edible and medicinal protein production and oral vaccine development. Moreover, this is the first report on secretory expression of a H. pylori antigen via using a food‐grade lactococcal expression system, and the engineered strain secreting UreB can be a hopeful H. pylori vaccine candidate. © 2017 Society of Chemical Industry
Process for production and purification of lethal toxin neutralizing factor (LTNF) from E. coli and its economic analysis
Authors: Hebbi Vishwanath , Pandi Kathiresan , Kumar Devendra , Komives Claire , Rathore Anurag S
Published: December 2017

BACKGROUND

Purification of peptides offers unique challenges with respect to obtaining the desired process yield and selectivity. Lethal Toxin Neutralizing Factor (LTNF) is a peptide that is known to neutralize snake venom in mice when the peptide is preincubated with the venom prior to intravenous injection. A process for producing highly purified recombinant LTNF has been developed. The process has been modelled in SuperPro designer using laboratory data for a plant capable of producing 10 kg of purified rLTNF. Economic analysis has been performed for manufacturing 3 ton of purified rLTNF

RESULTS

The process developed produces peptide in the form of concatemer that has been specifically designed to accumulate as insoluble inclusion bodies (IB) during expression in E. coli. A cation exchange chromatography step has been developed to capture the rLTNF concatemer at 140 g L‐1 dynamic binding capacity. Further, the purified concatemer is cleaved completely into monomeric rLTNF using alpha‐chymotrypsin enzyme. Finally, reversed phase high performance liquid chromatography has been designed to purify rLTNF with a recovery of more than 90% and purity greater than 98%. The overall process recovery is 78±2% resulting in 3.36 g of purified product per batch. Techno‐economic evaluation of the process has been performed to demonstrate its economic feasibility against currently marketed antivenom products.

CONCLUSIONS

The developed process is able to produce purified rLTNF with 78±2% recovery. The study shows that recombinant technology can be used to produce rLTNF cost effectively and shows potential as a substitute for currently available antivenoms against snakebite. © 2017 Society of Chemical Industry
An adsorptive bioprocess for production and recovery of resveratrol with Corynebacterium glutamicum
Authors: Braga Adelaide , Silva Marcelo , Oliveira Joana , Silva Ana Rita , Ferreira Patrícia , Ottens Marcel , Rocha Isabel , Faria Nuno
Published: December 2017

BACKGROUND

The growing interest in polyphenols has led to the design of industrial‐scale processes able to produce them by fermentation and recover them in a more sustainable way. The goal of this work is to present two integrated approaches for the recovery of resveratrol, obtained through fermentation. The production of resveratrol using Corynebacterium glutamicum and its continuous removal using a hydrophobic resin is described. Batch production is compared with in situ product removal, where Amberlite XAD‐7HP is either directly added to the medium (direct adsorption) or is present in an external column (external adsorption).

RESULTS

For both adsorption strategies tested, the amount of extracellular resveratrol increased from 75% to at least 90% of the total amount produced. However, lower total resveratrol concentrations were attained – 3.6 and 2.2 mg L‐1, for the external and direct contact strategies, respectively, versus 5.3 mg L‐1 for batch experiments.

CONCLUSIONS

The proposed in situ removal strategies demonstrated the potential of increasing the excretion of resveratrol produced intracellularly. These process configurations may not only lead to a simpler downstream process design, but also to the avoidance of potential problems with the toxicity of polyphenols to the cells, especially when larger titers are obtained. © 2017 Society of Chemical Industry
Feasibility and reproducibility of feature‐tracking‐based strain and strain rate measures of the left ventricle in different diseases and genders
Authors: Maceira Alicia M. , Tuset‐Sanchis Luis , López‐Garrido Miguel , San Andres Marta , López‐Lereu M. Pilar , Monmeneu Jose V. , García‐González M. Pilar , Higueras Laura
Published: December 2017

Background

The measurement of myocardial deformation by strain analysis is an evolving tool to quantify regional and global myocardial function.

Purpose

To assess the feasibility and reproducibility of myocardial strain/strain rate measurements with magnetic resonance feature tracking (MR‐FT) in healthy subjects and in patient groups.

Study Type

Prospective study.

Population

Sixty patients (20 hypertensives with left ventricular (LV) hypertrophy (H); 20 nonischemic dilated cardiomyopathy (D); 20 ischemic heart disease (I); as well as 20 controls (C) were included, 10 men and 10 women in each group.

Field Strength/Sequence

A 1.5T MR protocol including steady‐state free precession (SSFP) cine sequences in the standard views and late enhancement sequences.

Assessment

LV volumes, mass, global and regional radial, circumferential, and longitudinal strain/strain rate were measured using CVI42 software. The analysis time was recorded.

Statistical Tests

Intraobserver and interobserver agreement and intraclass correlation coefficients (ICC) were obtained for reproducibility assessment as well as differences according to gender and group of pertinence.

Results

Strain/strain rate analysis could be achieved in all subjects. The average analysis time was 14 ± 3 minutes. The average intraobserver ICC was excellent (ICC >0.90) for strain and good (ICC >0.75) for strain rate. Reproducibility of strain measurements was good to excellent (ICC >0.75) for all groups of subjects and both genders. Reproducibility of strain measurements was good for basal segments (ICC >0.75) and excellent for middle and apical segments (ICC >0.90). Reproducibility of strain rate measurements was moderate for basal segments (ICC >0.50) and good for middle and apical segments.

Data Conclusion

MR‐FT for strain/strain rate analysis is a feasible and highly reproducible technique. CVI42 FT analysis was equally feasible and reproducible in various pathologies and between genders. Better reproducibility was seen globally for middle and apical segments, which needs further clarification.

Level of Evidence: 3

Technical Efficacy Stage 2

J. Magn. Reson. Imaging 2018;47:1415–1425.
Improvement of the repeatability of parallel transmission at 7T using interleaved acquisition in the calibration scan
Authors: Kameda Hiroyuki , Kudo Kohsuke , Matsuda Tsuyoshi , Harada Taisuke , Iwadate Yuji , Uwano Ikuko , Yamashita Fumio , Yoshioka Kunihiro , Sasaki Makoto , Shirato Hiroki
Published: December 2017

Background

Respiration‐induced phase shift affects B0/B1+ mapping repeatability in parallel transmission (pTx) calibration for 7T brain MRI, but is improved by breath‐holding (BH). However, BH cannot be applied during long scans.

Purpose

To examine whether interleaved acquisition during calibration scanning could improve pTx repeatability and image homogeneity.

Study Type

Prospective.

Subjects

Nine healthy subjects.

Field Strength/Sequence

7T MRI with a two‐channel RF transmission system was used.

Assessment

Calibration scanning for B0/B1+ mapping was performed under sequential acquisition/free‐breathing (Seq‐FB), Seq‐BH, and interleaved acquisition/FB (Int‐FB) conditions. The B0 map was calculated with two echo times, and the B1+ map was obtained using the Bloch‐Siegert method. Actual flip‐angle imaging (AFI) and gradient echo (GRE) imaging were performed using pTx and quadrature‐Tx (qTx). All scans were acquired in five sessions. Repeatability was evaluated using intersession standard deviation (SD) or coefficient of variance (CV), and in‐plane homogeneity was evaluated using in‐plane CV.

Statistical Tests

A paired t‐test with Bonferroni correction for multiple comparisons was used.

Results

The intersession CV/SDs for the B0/B1+ maps were significantly smaller in Int‐FB than in Seq‐FB (Bonferroni‐corrected P < 0.05 for all). The intersession CVs for the AFI and GRE images were also significantly smaller in Int‐FB, Seq‐BH, and qTx than in Seq‐FB (Bonferroni‐corrected P < 0.05 for all). The in‐plane CVs for the AFI and GRE images in Seq‐FB, Int‐FB, and Seq‐BH were significantly smaller than in qTx (Bonferroni‐corrected P < 0.01 for all).

Data Conclusion

Using interleaved acquisition during calibration scans of pTx for 7T brain MRI improved the repeatability of B0/B1+ mapping, AFI, and GRE images, without BH.

Level of Evidence: 1

Technical Efficacy Stage 1

J. Magn. Reson. Imaging 2017.
Experience with an abdominal compression band for radiotherapy of upper abdominal tumours
Authors: Van Gelder Rebecca , Wong Shelley , Le Andrew , Podreka Alexander , Briggs Adam , Haddad Carol , Hardcastle Nicholas
Published: December 2017

Introduction

Radiotherapy outcomes are influenced by treatment delivery geometric accuracy and organ‐at‐risk dose. The location of abdominal structures such as the liver, kidneys and tumour volumes can be strongly influenced by respiratory motion. This increases geometric uncertainty and dose to organs‐at‐risk. One common method of minimising respiratory motion is abdominal compression (AC).

Methods

Fifteen patients being treated for radiotherapy to upper abdominal tumours were analysed. Each patient underwent 2 four‐dimensional computerised tomography (4D‐CT) scans, one with and one without AC with a pneumatic compression belt. Liver and kidney positions were measured on the 4DCT scans at the peak inspiratory and expiratory respiratory phases. The patient received radiation therapy treatment planned on the CT data set with the technique (compression or no compression) that provided the least respiratory motion.

Results

There was no statistically significant motion difference over the sample population with AC for the kidneys or liver. Of the 14 evaluable patients, 4, 6 and 6 saw reduction in superior‐inferior motion for left kidney, right kidney and liver respectively. The remainder either had negligible (<2 mm) or increase in motion with AC. For anterior‐posterior motion, 2, 2 and 1 saw a reduction for left‐kidney, right‐kidney and liver respectively.

Conclusion

AC through the use of a pneumatic compression belt was found to result in inconsistent reduction in kidney and liver respiratory motion. It is recommended that the effect of AC is evaluated on a per‐patient basis.
Cation binding in a soil with low exchange capacity: Implication for the structural rigidity of soil organic matter
Authors: Mouvenchery Yamuna Kunhi , Schaumann Gabriele Ellen
Published: December 2017

Two previous studies suggested that part of the cation sorption sites in soil organic matter with low exchange capacity have to be considered as “lonely”, i.e., too far from each other to allow direct cross‐linking by bivalent cations. The objective of this contribution was to understand the mechanisms controlling structural rigidity and physicochemical aging of the SOM (soil organic matter) and the role of water molecule bridges (WaMB) therein. For this, we evaluated the matrix rigidity of an organic surface layer of a Haplic Podzol on a quantitative basis, by assessing WaMB transition temperature (T*) directly after treatment with bivalent cations (Mg2+, Ca2+, or Ba2+) and after eight weeks of aging. Cation loading as well as cation type influenced matrix rigidity. Ba2+ induced the most rigid matrix and Mg2+ the weakest, which is in line with their binding strength in terms of Langmuir coefficient. The matrix rigidity increased with the cross‐linking activity, which is the product of loading and Langmuir constant of the respective cation. The aging process, however, was slowed down by the initial matrix rigidity, and the rigidity of the aged matrix decreased with increasing Langmuir constant. The degree of aging increased with increasing hydration enthalpy of the cation and decreased with increasing cation loading. Thus, directly after cation treatment, direct cross‐links by multivalent cations were most relevant, but WaMB increasingly gained influence on the matrix rigidity during aging. The untreated sample revealed a considerable number of WaMB, resulting in a fairly rigid and strongly cross‐linked matrix which, however, flexibly reacts on external influences like change in cation concentration or relative humidity. With these findings, the ideas on the relevance of indirect CaB‐WaMB associations between distant sorption sites for the rigidity and flexibility of the OM matrix as proposed in previous studies were confirmed on a mechanistic basis in this study.
A more sensitive detection of micrometastases of NSCLC in lymph nodes using the one‐step nucleic acid amplification (OSNA) method
Authors: Vodicka Josef , Mukensnabl Petr , Vejvodova Sarka , Spidlen Vladimir , Kulda Vlastimil , Topolcan Ondrej , Pesta Martin
Published: December 2017

Background

Detection of tumor cells in lymph nodes (LNs) removed during the treatment of pulmonary tumor by radical surgery is limited by the possibilities of standard histopathological methods. The goal of this study was to obtain more accurate pTNM status by a more sensitive detection of micrometastases in LNs.

Methods

A total of 885 LNs, an average of 13.8 LNs per patient, were removed during 64 surgeries. LNs from the same zone were pooled together as a group, five groups of LNs were examined in each patient. A total of 320 groups of LNs were examined. One‐step nucleic acid amplification (OSNA) method was compared to standard histopathological examination with haematoxylin‐eosin (H&E) staining and CK19 immunohistochemistry, specifically by an ultimate analysis of all intraoperatively removed LNs.

Results

Identical results for H&E and OSNA examinations were recorded in 286 groups of LNs (89.4%). In total, positive examinations were recorded in 27 groups of LNs (8.4%) using the OSNA method, which were H&E negative. In seven groups of LNs (2.2%), the H&E examination was positive, while OSNA method produced negative results.

Conclusions

The OSNA examination led to a higher pTNM stage classification in 14 (21.9%) patients. The clinical significance remains the subject of follow‐up research.
Effects of local multivisceral resection for clinically locally advanced rectal cancer on long‐term outcomes
Authors: Dinaux Anne M. , Leijssen Lieve G. J. , Bordeianou Liliana G. , Kunitake Hiroko , Berger David L.
Published: December 2017

Introduction

Multivisceral resection is occasionally needed to obtain clear margins in patients with transmural rectal cancer. Most series demonstrate equivalent outcomes between those patients who undergo multivisceral resections and those who do not, provided an R0‐resection is achieved. This study focuses solely on patients who received neoadjuvant treatment for clinically transmural rectal cancers and underwent a local multivisceral R0‐resection.

Methods

A retrospective, single center analysis of consecutive series of patients who received a surgical R0‐resection after neoadjuvant treatment for a clinically transmural, non‐metastatic, primary rectal cancer. All patients were operated on between 2004 and 2015.

Results

A total of 279 patients was included, of whom 29 patients underwent a local multivisceral R0‐resection (LMVR). These patients were more often female and less often diagnosed through screening. Pathologic AJCC‐staging was significantly lower for non‐LMVR patients, with more favorable tumor characteristics. LMVR patients demonstrated higher rates of distant disease recurrence, and impaired survival, even after adjusting for disease stage.

Conclusion

An R0‐resection after neoadjuvant therapy led to comparative local control of disease; however, patients with multivisceral resection had more distant recurrence and impaired survival, compared to those did not undergo a multivisceral resection. Further research should determine optimal postoperative care.
Chiral separation of disease biomarkers with 2‐hydroxycarboxylic acid structure
Authors: Calderón Carlos , Santi Cristina , Lämmerhofer Michael
Published: December 2017

Chiral 2‐hydroxycarboxylic acids are compounds that have been linked to particular diseases and are putative biomarkers with some diagnostic potential. The importance of identifying whether a particular enantiomer is related to certain diseases has been encouraged recently. However, in many cases it has not yet been elucidated whether there are stereochemical implications with respect to these biomarkers and whether their enantioselective analysis provides new insights and diagnostic potential. In this study 13 disease‐related chiral 2‐hydrocarboxylic acids were studied for their chiral separation by high‐performance liquid chromatography on three cinchona alkaloid‐derived chiral stationary phases. From a subgroup of eight 2‐hydroxymonocarboxylic acids, baseline resolution could be achieved and inversion of elution order by exchanging tert‐butylcarbamoyl quinidine chiral stationary phase (Chiralpak QD‐AX) for the corresponding quinine analogue (Chiralpak QN‐AX) is shown for seven of them. Furthermore, conditions for chiral separation of the 2‐hydroxydicarboxylic acids, citramalic acid, 2‐isopropylmalic acid, and 2‐hydroxyadipic acid are reported and compared to the previous reported conditions for 2‐hydroxyglutaric acid and malic acid.
Power Doppler Ultrasonography and Shear Wave Elastography as Complementary Imaging Methods for Suspected Local Breast Cancer Recurrence
Authors: Jales Rodrigo Menezes , Dória Maira Teixeira , Serra Kátia Piton , Miranda Mila Meneguelli , Menossi Carlos Alberto , Schumacher Klaus , Sarian Luis Otávio
Published: December 2017

Objectives

To prospectively investigate the diagnostic accuracy and clinical consequences of power Doppler morphologic criteria and shear wave elastography (SWE) as complementary imaging methods for evaluation of suspected local breast cancer recurrence in the ipsilateral breast or chest wall.

Methods

Thirty‐two breast masses with a suspicion of local breast cancer recurrence on B‐mode ultrasonography underwent complementary power Doppler and SWE evaluations. Power Doppler morphologic criteria were classified as avascular, hypovascular, or hypervascular. Shear wave elastography was classified according to a 5‐point scale (SWE score) and SWE maximum elasticity. Diagnostic accuracy was assessed by the sensitivity, specificity, and area under the curve. A decision curve analysis assessed clinical consequences of each method. The reference standard for diagnosis was defined as core needle or excisional biopsy.

Results

Histopathologic examinations revealed 9 (28.2%) benign and 23 (71.8%) malignant cases. Power Doppler ultrasonography (US) had sensitivity of 34.8% (95% confidence interval [CI], 6.6%–62.9%) and specificity of 45.4% (95% CI, 19.3%–71.5%). The SWE score (≥3) had sensitivity of 87.0% (95% CI, 66.4%–97.2%) and specificity of 44.4% (95% CI, 13.7%–78.8%). The SWE maximum elasticity (velocity > 6.5cm/s) had sensitivity of 87% (95% CI, 66.4%–97.2%) and specificity of 77.8% (95% CI, 40.0% to 97.2%). The areas under the curves for the SWE score and SWE maximum elasticity were 0.71 (95% CI, 0.53–0.87) and 0.82 (95% CI, 0.64–0.93), respectively (P = .32).

Conclusions

Power Doppler US is unsuitable for discrimination between local breast cancer recurrence and fibrosis. Although the SWE score and SWE maximum elasticity can make this discrimination, the use of these methods to determine biopsy may lead to poorer clinical outcomes than the current practice of performing biopsies of all suspicious masses.
The biogeochemical cycling of iron, copper, nickel, cadmium, manganese, cobalt, lead, and scandium in a California Current experimental study
Authors: Mellett Travis , Brown Matthew T. , Chappell P. Dreux , Duckham Carolyn , Fitzsimmons Jessica N. , Till Claire P. , Sherrell Robert M. , Maldonado Maria T. , Buck Kristen N.
Published: December 2017

A 3‐day shipboard incubation experiment was conducted in the California Current System in July 2014 to investigate the cycling of iron (Fe), copper (Cu), nickel (Ni), cadmium (Cd), manganese (Mn), cobalt (Co), lead (Pb), and scandium (Sc) under a range of light and particle conditions. Filtered (< 0.2 μm) and unfiltered treatments were incubated under the following light conditions: Dark, light (“UV”), and light without the ultraviolet (UV) wavelengths (“noUV”). The experiment was sampled for carbon and Fe uptake rates, dissolved trace metal concentrations (Fe, Cu, Ni, Cd, Mn, Co, Pb, Sc), Fe and Cu speciation, size‐fractionated concentrations of Cd and Fe, and diatom community composition from DNA sequencing. Exposure to UV light increased phytoplankton Fe uptake in the first 24 h of the incubation relative to the noUV treatment, suggesting that a fraction of the ambient ligand‐bound Fe was photoreactive. Fe‐binding organic ligand production was observed in the unfiltered light treatments in association with increasing chlorophyll a, and evidence for Cu‐binding ligand production in these treatments was also observed. Biological uptake of Cd and Co was observed along with scavenging of dissolved Pb. Manganese appeared to be rapidly oxidized by Mn‐oxidizing bacteria with concomitant drawdown of dissolved Ni. Scandium displayed similar trends to Fe, reinforcing the limited observations of the physicochemical similarities between these two elements in seawater. Overall, this study highlights distinct impacts of photochemical processes, scavenging, and biological effects on marine trace metal cycling in an environment characterized by seasonal upwelling.
Influence of vertical mixing on light‐dependency of phytoplankton growth
Authors: Köhler Jan , Wang Lan , Guislain Alexis , Shatwell Tom
Published: December 2017

Phytoplankton growth depends not only on mean intensity but also on the dynamics of the light supply. In surface mixed layers, phytoplankton may rapidly move between strong light and almost darkness. The nonlinear light‐dependency of growth may differ between constant and fluctuating light because of the different frequency distribution of light and/or acclimation processes. The present study compares for the first time light‐dependency of photosynthesis and growth of phytoplankton communities in situ under defined mixing conditions and at fixed depths. Maximum growth rates per day were not significantly different, but the growth efficiency was much higher under constant light than under fluctuating light of sub‐saturating daily irradiance. Phytoplankton incubated under fluctuating light needed about three times higher mean daily irradiances to balance photosynthesis and losses than under constant light. The difference in growth efficiency was mostly caused by the different frequency distribution of underwater light, as was estimated by a photosynthesis model of sufficient temporal resolution. The present study indicates a considerable overestimation of phytoplankton growth at sub‐saturating light in well‐mixed water layers by the common growth measurements under constant light. This implies an underestimation of the compensation light intensities and respective overestimations of the critical mixing depths.
Stretchable Photonic ‘Fermi Arcs’ in Twisted Magnetized Plasma
Authors: Xia Lingbo , Gao Wenlong , Yang Biao , Guo Qinghua , Liu Hongchao , Han Jiaguang , Zhang Weili , Zhang Shuang
Published: December 2017

Weyl points, three‐dimensional linear bulk bands crossings possessing intrinsic helicities, are counterparts of magnetic monopoles in the momentum space. One of the most important features of Weyl semimetals is the presence of topologically protected non‐trivial surface states at the boundary that connect between Weyl points of opposite charges. In condensed matter physics, these surface states are called Fermi arcs whose length measures the topological strength of the system. Here we theoretically show that photonic ‘Fermi arcs’ can exist at the interface between two magnetized plasma under static bias magnetic fields of different orientations, i.e. a twisted configuration, whereas the length of the ‘Fermi arcs’ can be arbitrarily stretched by varying the relative orientation and intensities of two static bias magnetic fields. Interestingly, the ‘Fermi arcs’ join two Weyl points of the same sign but residing on different side of the interface. Our work gives insight to the connectivity of ‘Fermi arcs’ between two topological semimetals and could open gateway towards tunable photonic topological systems.
The grounded Martin's axiom
Authors: Habič Miha E.
Published: December 2017

We introduce a variant of Martin's axiom, called the grounded Martin's axiom, or , which asserts that the universe is a c.c.c. forcing extension in which Martin's axiom holds for posets in the ground model. This principle already implies several of the combinatorial consequences of . The new axiom is shown to be consistent with the failure of and a singular continuum. We prove that is preserved in a strong way when adding a Cohen real and that adding a random real to a model of preserves (even though it destroys itself). We also consider the analogous variant of the proper forcing axiom.
Fabrication of a Highly Sensitive Stretchable Strain Sensor Utilizing a Microfibrous Membrane and a Cracking Structure on Conducting Polymer
Authors: Jeon Hyungkook , Hong Seong Kyung , Cho Seong J. , Lim Geunbae
Published: December 2017

Recently, the detection of human motion has attracted considerable attention for the development of smart healthcare systems. Flexible or stretchable strain sensors are required to measure deformations on arbitrarily shaped human skin areas caused by human motion, and numerous studies have explored the development of such sensors. Here, a highly sensitive stretchable strain sensor is introduced, which consists of elastic fibrous membrane coated with conducting polymer. The membrane can be utilized to detect applied strain by measuring the conductance change caused by the change in the nanocracking structure on the coated conducting polymer layer. Furthermore, by collecting aligned microfibers as the fibrous membrane during electrospinning process, the sensor exhibits higher sensitivity (more than 40‐fold higher than the nonaligned version). Although limitations still remain in the repeatability and the applicability of the sensor, the developed sensor will demonstrate great potential for measuring applied strain and stress over a wide sensing range with high sensitivity is expected.
Ultralight and Low Thermal Conductivity Polyimide–Polyhedral Oligomeric Silsesquioxanes Aerogels
Authors: Wu Yi‐wei , Zhang Wen‐chao , Yang Rong‐jie
Published: December 2017

The research on rapid growing, organic, and ultralight cross‐linking polyimide aerogels is receiving significant interest. In this work, poly(aminophenyl) silsesquioxanes (PAPSQ) are introduced as a cross‐linker into the polymide (PI) aerogel. A comparative aerogel is prepared, using 1,3,5‐triaminophenoxybenzene (TAB) as a cross‐linker. The aerogels are characterized in terms of their micro‐ and nanostructures, density, shrinkage, thermal conductivity and insulation, and mechanical properties. It is found that the PI‐PAPSQ aerogel have lower density, smaller shrinkage, lower thermal conductivity, higher thermal stability and insulation, and higher compression strength than the PI‐TAB aerogel. The 1.1 wt% PI‐PAPSQ shows the lowest aerogel density (0.010 g cm−3) and the 2.2 wt% PI‐PAPSQ has a lower thermal conductivity (22.90 mW (m K)−1 than air. A model of the PI‐TAB and PI‐PAPSQ cross‐linking networks are proposed to explain the excellent performance of the PI‐PAPSQ aerogel.
Modeling of RAFT Copolymerization with Crosslinking of Styrene/Divinylbenzene in Supercritical Carbon Dioxide
Authors: López‐Domínguez Porfirio , Hernández‐Ortiz Julio César , Vivaldo‐Lima Eduardo
Published: December 2017

A kinetic model for the reversible addition‐fragmentation chain transfer radical copolymerization of vinyl/divinyl monomers in supercritical carbon dioxide, using a multifunctional approach for polymer network formation, is presented. The process is assumed to proceed as a dispersion polymerization in three stages, with two phases: CO2‐ and polymer‐rich phases. A simple model for partition of the main components within the two phases is used. Experimental data of monomer conversion, molar mass development, evolution of gel fraction, and swelling of the polymer network for a styrene/divinylbenzene system, at 80 °C and 300 bar, are used to validate the model. Good agreement between model predictions and experimental data is obtained.
Identification of differentially expressed genes involved in spore germination of Penicillium expansum by comparative transcriptome and proteome approaches
Authors: Zhou Ting , Wang Xiaohong , Luo Jin , Ye Bishun , Zhou Yingying , Zhou Liwan , Lai Tongfei
Published: December 2017

In this study, Penicillium expansum, a common destructive phytopathogen and patulin producer was isolated from naturally infected apple fruits and identified by morphological observation and rDNA‐internal transcribed spacer analysis. Subsequently, a global view of the transcriptome and proteome alteration of P. expansum spores during germination was evaluated by RNA‐seq (RNA sequencing) and iTRAQ (isobaric tags for relative and absolute quantitation) approaches. A total of 3,026 differentially expressed genes (DEGs), 77 differentially expressed predicted transcription factors and 489 differentially expressed proteins (DEPs) were identified. The next step involved screening out 130 overlapped candidates through correlation analysis between the RNA‐seq and iTRAQ datasets. Part of them showed a different expression trend in the mRNA and protein levels, and most of them were involved in metabolism and genetic information processing. These results not only highlighted a set of genes and proteins that were important in deciphering the molecular processes of P. expansum germination but also laid the foundation to develop effective control methods and adequate environmental conditions.
Toward quantitative fast diffusion kurtosis imaging with b‐values chosen in consideration of signal‐to‐noise ratio and model fidelity
Authors: Kuo Yen‐Shu , Yang Shun‐Chung , Chung Hsiao‐Wen , Wu Wen‐Chau
Published: December 2017

Purpose

Diffusion kurtosis (DK) imaging is a variant of conventional diffusion magnetic resonance (MR) imaging that allows assessment of non‐Gaussian diffusion. Fast DK imaging expedites the procedure by decreasing both scan time (acquiring the minimally required number of b‐values) and computation time (obviating least‐square curve fitting). This study aimed to investigate the applicability of fast DK imaging for both cerebral gray matter and white matter as a quantitative method.

Methods

Seventeen healthy volunteers were recruited and each provided written informed consent before participation. On a 3‐Tesla clinical MR system, diffusion imaging was performed with 12 b‐values ranging from 0 to 4000 s/mm2. Diffusion encoding was along three orthogonal directions (slice selection, phase encoding, and frequency encoding) in separate series. Candidate b‐values were chosen by first determining the maximum b‐value (bmax) in the context of signal‐to‐noise ratio and then assessing the model fidelity for all b‐value combinations within bmax. Diffusion coefficient (D) and diffusion kurtosis coefficient (K) were derived from these candidates and assessed for their dependence on b‐value combination.

Results

Our data suggested bmax to be 2200 s/mm2 as a trade‐off between the percentage (~80%) of voxels statistically detectable against background and the sensitivity to non‐Gaussian diffusion in both gray matter and white matter. The measurement dependence on b‐value was observed predominantly in areas with a considerable amount of cerebrospinal fluid. In most gray matter and white matter, b‐value combinations do not cause statistical difference in the calculated D and K.

Conclusions

For fast DK imaging to be quantitatively applicable in both gray matter and white matter, bmax should be chosen to ensure adequate signal‐to‐noise ratio in the majority of gray/white matter and the two nonzero b‐values should be chosen in consideration of model fidelity to mitigate the dependence of derived indices on b‐values.
Low‐frequency ESR studies on permeable and impermeable deuterated nitroxyl radicals in corn oil solution
Authors: David Jebaraj D. , Utsumi Hideo , Milton Franklin Benial A.
Published: December 2017

Low‐frequency electron spin resonance studies were performed for 2 mM concentration of deuterated permeable and impermeable nitroxyl spin probes, 3‐methoxycarbonyl‐2,2,5,5‐tetramethyl‐pyrrolidine‐1‐oxyl and 3‐carboxy‐2,2,5,5,‐tetramethyl‐1‐pyrrolidinyloxy in pure water and various concentrations of corn oil solution. The electron spin resonance parameters such as the line width, hyperfine coupling constant, g factor, rotational correlation time, permeability, and partition parameter were estimated. The broadening of line width was observed for nitroxyl radicals in corn oil mixture. The rotational correlation time increases with increasing concentration of corn oil, which indicates the less mobile nature of spin probe in corn oil mixture. The membrane permeability and partition parameter values were estimated as a function of corn oil concentration, which reveals that the nitroxyl radicals permeate equally into the aqueous phase and oil phase at the corn oil concentration of 50%. The electron spin resonance spectra demonstrate the permeable and impermeable nature of nitroxyl spin probes. From these results, the corn oil concentration was optimized as 50% for phantom studies. In this work, the corn oil and pure water mixture phantom models with various viscosities correspond to plasma membrane, and whole blood membrane with different hematocrit levels was studied for monitoring the biological characteristics and their interactions with permeable nitroxyl spin probe. These results will be useful for the development of electron spin resonance and Overhauser‐enhanced magnetic resonance imaging modalities in biomedical applications.
Implementation of a coupled plastic damage distinct lattice spring model for dynamic crack propagation in geomaterials
Authors: Jiang Chao , Zhao Gao‐Feng
Published: December 2017

This paper studies dynamic crack propagation by employing the distinct lattice spring model (DLSM) and 3‐dimensional (3D) printing technique. A damage‐plasticity model was developed and implemented in a 2D DLSM. Applicability of the damage‐plasticity DLSM was verified against analytical elastic solutions and experimental results for crack propagation. As a physical analogy, dynamic fracturing tests were conducted on 3D printed specimens using the split Hopkinson pressure bar. The dynamic stress intensity factors were recorded, and crack paths were captured by a high‐speed camera. A parametric study was conducted to find the influences of the parameters on cracking behaviors, including initial and peak fracture toughness, crack speed, and crack patterns. Finally, selection of parameters for the damage‐plasticity model was determined through the comparison of numerical predictions and the experimentally observed cracking features.
Impact of intratumoral heterogeneity of breast cancer tissue on quantitative metabolomics using high‐resolution magic angle spinning 1H NMR spectroscopy
Authors: Gogiashvili Mikheil , Horsch Salome , Marchan Rosemarie , Gianmoena Kathrin , Cadenas Cristina , Tanner Berno , Naumann Sabrina , Ersova Diana , Lippek Frank , Rahnenführer Jörg , Andersson Jan T. , Hergenröder Roland , Lambert Jörg , Hengstler Jan G. , Edlund Karolina
Published: December 2017

High‐resolution magic angle spinning (HR MAS) nuclear magnetic resonance (NMR) spectroscopy is increasingly being used to study metabolite levels in human breast cancer tissue, assessing, for instance, correlations with prognostic factors, survival outcome or therapeutic response. However, the impact of intratumoral heterogeneity on metabolite levels in breast tumor tissue has not been studied comprehensively. More specifically, when biopsy material is analyzed, it remains questionable whether one biopsy is representative of the entire tumor. Therefore, multi‐core sampling (n = 6) of tumor tissue from three patients with breast cancer, followed by lipid (0.9‐ and 1.3‐ppm signals) and metabolite quantification using HR MAS 1H NMR, was performed, resulting in the quantification of 32 metabolites. The mean relative standard deviation across all metabolites for the six tumor cores sampled from each of the three tumors ranged from 0.48 to 0.74. This was considerably higher when compared with a morphologically more homogeneous tissue type, here represented by murine liver (0.16–0.20). Despite the seemingly high variability observed within the tumor tissue, a random forest classifier trained on the original sample set (training set) was, with one exception, able to correctly predict the tumor identity of an independent series of cores (test set) that were additionally sampled from the same three tumors and analyzed blindly. Moreover, significant differences between the tumors were identified using one‐way analysis of variance (ANOVA), indicating that the intertumoral differences for many metabolites were larger than the intratumoral differences for these three tumors. That intertumoral differences, on average, were larger than intratumoral differences was further supported by the analysis of duplicate tissue cores from 15 additional breast tumors. In summary, despite the observed intratumoral variability, the results of the present study suggest that the analysis of one, or a few, replicates per tumor may be acceptable, and supports the feasibility of performing reliable analyses of patient tissue.
A combined connectivity mapping and pharmacoepidemiology approach to identify existing medications with breast cancer causing or preventing properties
Authors: Busby John , Murray Liam , Mills Ken , Zhang Shu‐Dong , Liberante Fabio , Cardwell Chris R.
Published: December 2017

Purpose

We applied a novel combined connectivity mapping and pharmacoepidemiological approach to identify medications that alter breast cancer risk.

Methods

The connectivity mapping process identified 6 potentially cancer‐causing (meloxicam, azithromycin, rizatriptan, citalopram, rosiglitazone, and verapamil) and 4 potentially cancer‐preventing (bendroflumethiazide, sertraline, fluvastatin, and budesonide) medications that were suitable for pharmacoepidemiological investigation. Within the UK Clinical Practice Research Datalink, we matched 45,147 breast cancer cases to 45,147 controls based on age, year, and general practice. Medication use was determined from electronic prescribing records. We used conditional logistic regression to calculate odds ratios (ORs) for the association between medication use and cancer risk after adjustment for comorbidities, lifestyle factors, deprivation, and other medication use.

Results

Bendroflumethiazide was associated with increased breast cancer risk (OR: 1.11; 95% CI: 1.06, 1.15); however the connectivity mapping exercise predicted that this medication would reduce risk. There were no statistically significant associations for any of the other candidate medications, with ever use ORs ranging from 0.93 (95% CI: 0.78, 1.11) for azithromycin to 1.16 (95% CI: 0.99, 1.37) for verapamil.

Conclusions

In this instance, our combined connectivity mapping and pharmacoepidemiological approach did not identify any additional medications that were substantially associated with breast cancer risk. This could be due to limitations in the connectivity mapping, such as implausible dosage requirements, or the pharmacoepidemiology, such as residual confounding.
Dimethyl sulfoxide/deep eutectic solvents mixtures as media in the reaction of 1‐fluoro‐2,4‐dinitrobenzene with piperidine: A solvent effect study
Authors: Harifi‐Mood Ali Reza , Sadrzadeh Samira
Published: December 2017

Aromatic nucleophilic substitution reaction of 1‐fluoro‐2,4‐dinitrobenzene with piperidine was kinetically investigated in ethylene glycol‐choline chloride and glycerol‐choline chloride as 2 deep eutectic solvents (DESs) mixed with dimethyl sulfoxide, in whole mole fractions, at room temperature. The investigation of the reaction in different concentrations of the piperidine shows that the reaction follows the base‐catalyzed mechanism. The measured rate coefficients of the reaction demonstrated a sharp decreasing in all mixtures with the increasing mole fraction of DESs. Linear free energy relationship investigations confirm that hydrogen bond donor ability in addition to polarity‐polarizability of the media has a major effect on the reaction rate. The decrease in the rate coefficient is attributed to not only hydrogen‐bonding donor interactions of the media with piperidine as both reactant and catalyst but also the preferential solvation of reactants by DES compared with the intermediate of the reaction.