bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between metformin use after surgery for colorectal cancer and oncological outcomes: A nationwide register‐based study
Authors: Fransgaard Tina , Thygesen Lau Caspar , Gögenur Ismail
Published: February 2018

Colorectal cancer is one of the most common malignancies in the Western world, and even after surgical removal, there is a high recurrence rate. Metformin treatment has been associated with a reduced risk of developing cancer, but whether metformin influences the risk of recurrence is unknown. The aim of our study was to examine the association between treatment with metformin and recurrence‐free, disease‐free survival and all‐cause mortality after surgery for colorectal cancer. The study was an observational register‐based study and included 25,785 patients, of which 1,116 had medically treated diabetes and 966 started metformin treatment at some point postoperatively. Diabetes was not associated with neither disease‐free (HRadjusted = 1.09, 95% CI 0.97–1.21, p = 0.15) nor recurrence‐free survival (HRadjusted = 1.13, 95% CI 0.95–1.35, p = 0.17). The study found no difference in regards to disease‐free or recurrence‐free survival between the metformin treated group (HRRFS = 1.06, 95% CI 0.87–1.15, p = 0.57, HRDFS = 1.01, 95% CI 0.89–1.15, p = 0.85) and non‐diabetic patients. Patients with diabetes had increased all‐cause mortality (HRadjusted = 1.29, 95% CI 1.16–1.45, p < 0.0001). Metformin treatment did not affect all‐cause mortality (HR = 1.07, 95% CI 0.94–1.22, p = 0.33) compared to non‐diabetic patients. In conclusion, our study did not find an association between diabetes or metformin treatment and recurrence‐free or disease‐free survival after surgery for colorectal cancer. However, diagnosis of diabetes is associated with increased all‐cause mortality.
Investigating adoption factors of 3G services: An empirical study in Vietnam
Authors: Tapanainen Tommi J. , Dao Kien T. , Nguyen Hai T. T.
Published: February 2018

This study aimed to examine the factors that affect the 3G mobile services adoption. The technology acceptance model was used, and structural equation modeling was applied to the data sample obtained from a survey in Hanoi, the capital of Vietnam. The research found that perceived usefulness has the strongest effect on intention and attitude to adopt. Social influence does not affect 3G services adoption. The result also underlines the variable of attitude that it should not be eliminated from technology acceptance models. Based on the findings, this research proposes practical recommendations to 3G providers, such as enhancing the service usefulness and focusing on features developed via collaborations between telecommunication carriers and content developers. Furthermore, 3G providers are recommended to focus on understanding their customers' needs better rather than relying on peer and social advertising in promoting 3G services. Finally, future research is proposed to study the effect of different combinations of perceived enjoyment, usefulness, and ease of use, and the relationship between perceived cost, social influence, and intention on 3G services adoption.
Environmental mixture with estrogenic activity increases Hsd3b1 expression through estrogen receptors in immature rat granulosa cells
Authors: Samardzija Nenadov Dragana , Pogrmic‐Majkic Kristina , Fa Svetlana , Stanic Bojana , Tubic Aleksandra , Andric Nebojsa
Published: February 2018

Humans are exposed not only to single endocrine disruptors, but also to chemical mixtures that can adversely affect their reproductive health. Steroidogenesis in reproductive tissues is emerging as the key target of endocrine disruptor action. Here, we analyzed the effect of environmental chemical mixtures with estrogenic activity on steroidogenic processes in immature rat granulosa cells and whether the observed steroidogenic effects were mediated through estrogen receptors. Extracts from untreated wastewater were prepared by solid‐phase extraction and silica gel fractionation. ER‐CALUX assay showed that the polar fractions of wastewater exerted different levels of estrogenic activity. Exposure of immature granulosa cells to the polar fraction exerting 9 ng of 17β‐estradiol equivalents per liter of water of estrogenic activity increased mRNA expression of the key enzymes of progesterone biosynthetic pathway Star and Hsd3b1, but did not alter the level of Cyp19a1 and Lhr. Addition of estrogen receptor inhibitor ICI 182 780 prevented the estrogenic mixture‐induced increase in Hsd3b1, but not Star mRNA level in immature granulosa cells. These results indicate that the environmental chemical mixtures with estrogenic activity exert endocrine disrupting effects by augmenting the progesterone biosynthetic pathway in immature rat granulosa cells, which is an effect achieved in part through activation of the estrogen receptors.
High temporal resolution motion estimation using a self‐navigated simultaneous multi‐slice echo planar imaging acquisition
Authors: Teruel Jose R. , Kuperman Joshua M. , Dale Anders M. , White Nathan S.
Published: February 2018

Background

Subject motion is known to produce spurious covariance among time‐series in functional connectivity that has been reported to induce distance‐dependent spurious correlations.

Purpose

To present a feasibility study for applying the extended Kalman filter (EKF) framework for high temporal resolution motion correction of resting state functional MRI (rs‐fMRI) series using each simultaneous multi‐slice (SMS) echo planar imaging (EPI) shot as its own navigator.

Study Type

Prospective feasibility study.

Population/Subjects

Three human volunteers.

Field Strength/Sequence

3T GE DISCOVERY MR750 scanner using a 32‐channel head coil. Simultaneous multi‐slice rs‐fMRI sequence with repetition time (TR)/echo time (TE) = 800/30 ms, and SMS factor 6.

Assessment

Motion estimates were computed using two techniques: a conventional rigid‐body volume‐wise registration; and a high‐temporal resolution motion estimation rigid‐body approach. The reference image was resampled using the estimates obtained from both approaches and the difference between these predicted volumes and the original moving series was summarized using the normalized mean squared error (NMSE).

Statistical Tests

Direct comparison of NMSE values.

Results

High‐temporal motion estimation was always superior to volume‐wise motion estimation for the sample presented. For staged continuous rotations, the NMSE using high‐temporal resolution motion estimates ranged between [0.130, 0.150] for the first volunteer (in‐plane rotations), between [0.060, 0.068] for the second volunteer (in‐plane rotations), and between [0.063, 0.080] for the third volunteer (through‐plane rotations). These values went up to [0.384, 0.464]; [0.136, 0.179]; and [0.080, 0.096], respectively, when using volume‐wise motion estimates.

Data Conclusion

Accurate high‐temporal rigid‐body motion estimates can be obtained for rs‐fMRI taking advantage of simultaneous multi‐slice EPI sub‐TR shots.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2018;48:780–787.
Deep learning enables reduced gadolinium dose for contrast‐enhanced brain MRI
Authors: Gong Enhao , Pauly John M. , Wintermark Max , Zaharchuk Greg
Published: February 2018

Background

There are concerns over gadolinium deposition from gadolinium‐based contrast agents (GBCA) administration.

Purpose

To reduce gadolinium dose in contrast‐enhanced brain MRI using a deep learning method.

Study type

Retrospective, crossover.

Population

Sixty patients receiving clinically indicated contrast‐enhanced brain MRI.

Sequence

3D T1‐weighted inversion‐recovery prepped fast‐spoiled‐gradient‐echo (IR‐FSPGR) imaging was acquired at both 1.5T and 3T. In 60 brain MRI exams, the IR‐FSPGR sequence was obtained under three conditions: precontrast, postcontrast images with 10% low‐dose (0.01mmol/kg) and 100% full‐dose (0.1 mmol/kg) of gadobenate dimeglumine. We trained a deep learning model using the first 10 cases (with mixed indications) to approximate full‐dose images from the precontrast and low‐dose images. Synthesized full‐dose images were created using the trained model in two test sets: 20 patients with mixed indications and 30 patients with glioma.

Assessment

For both test sets, low‐dose, true full‐dose, and the synthesized full‐dose postcontrast image sets were compared quantitatively using peak‐signal‐to‐noise‐ratios (PSNR) and structural‐similarity‐index (SSIM). For the test set comprised of 20 patients with mixed indications, two neuroradiologists scored blindly and independently for the three postcontrast image sets, evaluating image quality, motion‐artifact suppression, and contrast enhancement compared with precontrast images.

Statistical Analysis

Results were assessed using paired t‐tests and noninferiority tests.

Results

The proposed deep learning method yielded significant (n = 50, P < 0.001) improvements over the low‐dose images (>5 dB PSNR gains and >11.0% SSIM). Ratings on image quality (n = 20, P = 0.003) and contrast enhancement (n = 20, P < 0.001) were significantly increased. Compared to true full‐dose images, the synthesized full‐dose images have a slight but not significant reduction in image quality (n = 20, P = 0.083) and contrast enhancement (n = 20, P = 0.068). Slightly better (n = 20, P = 0.039) motion‐artifact suppression was noted in the synthesized images. The noninferiority test rejects the inferiority of the synthesized to true full‐dose images for image quality (95% CI: –14–9%), artifacts suppression (95% CI: –5–20%), and contrast enhancement (95% CI: –13–6%).

Data Conclusion

With the proposed deep learning method, gadolinium dose can be reduced 10‐fold while preserving contrast information and avoiding significant image quality degradation.

Level of Evidence: 3

Technical Efficacy: Stage 5

J. MAGN. RESON. IMAGING 2018;48:330–340.
Noninvasive assessment of intracranial elastance and pressure in spontaneous intracranial hypotension by MRI
Authors: Tsai Yi‐Hsin , Chen Hung‐Chieh , Tung Hsin , Wu Yi‐Ying , Chen Hsian‐Min , Pan Kuan‐Jung , Cheng Da‐Chuan , Chen Jeon‐Hor , Chen Clayton Chi‐Chang , Chai Jyh‐Wen , Shen Wu‐Chung
Published: February 2018

Background

Spontaneous intracranial hypotension (SIH) is often misdiagnosed, and can lead to severe complications. Conventional MR sequences show a limited ability to aid in this diagnosis. MR‐based intracranial pressure (MR‐ICP) may be able to detect changes of intracranial elastance and pressure.

Purpose

To determine whether MR‐ICP is able to differentiate SIH patients from normal subjects, improve diagnostic sensitivity, and provide an insight into the pathophysiology.

Study Type

Prospective.

Subjects

Twenty‐eight SIH cases with orthostatic headache and 20 healthy volunteers.

Field Strength/Sequence

Cine phase‐contrast MRI on a 1.5T scanner.

Assessment

Intracranial elastance (IE) was derived from the ratio of the peak‐to‐peak cerebrospinal fluid (CSF) pressure gradient (PGcsf‐pp) and intracranial volume change, obtained by summing all flows before each sequential cardiac frame.

Statistical Tests

Student's t‐test was used to compare the MR‐ICP indexes and flow parameters between SIH patients and healthy volunteers (P < 0.01).

Results

The SIH patients with cervical epidural venous dilatation (EVD) had an IE of 0.121 ± 0.027 mmHg/cm/ml, significantly higher than that of the normal volunteers (0.085 ± 0.027 mmHg/cm/ml; P = 0.002). In contradistinction, the EVD‐negative SIH patients, including four with no sign of CSF leaks, had significantly lower IE (0.055 ± 0.012 mmHg/cm/ml) compared with the normal volunteers and the EVD‐positive group (P = 0.001, P < 0.001). The EVD‐negative patients had significantly lower PGcsf‐pp (0.024 ± 0.007 mmHg/cm) compared with the normal volunteers and the EVD‐positive group (0.035 ± 0.011 mmHg/cm, 0.040 ± 0.010 mmHg/cm; P = 0.003, P < 0.001). Additionally, the MRI flow study showed a significant decrease in transcranial inflow and outflow of SIH patients (P < 0.01).

Data Conclusion

We found that the MR‐ICP method is potentially more sensitive than morphological MRI in the early diagnosis of SIH. Also, contrary to common belief, our results suggest that an abnormal craniospinal elastance might be the cause of SIH, instead of CSF leak.

Level of Evidence: 2

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2018;47:1255–1263.
Simultaneous determination and pharmacokinetics study of four quinones in rat plasma by ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry after the oral administration of Qianzhi capsules
Authors: Gao Mingjie , Wang Zhibin , Yang Jing , Wang Liqian , Wu Chengcui , Cui Binbin , Yang Chunjuan
Published: February 2018

A sensitive, specific, and accurate ultra high‐performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed and validated for the simultaneous quantification of purpurin, munjistin, mollugin, and alizarin from Qianzhi capsules in rat plasma. Chromatographic separation was performed on an Agilent Eclipse Plus C18 RRHD column with a mobile phase consisting of methanol and 5 mM ammonium acetate/water with gradient elution. The analytes were quantified on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring mode and switching the electrospray ion source polarity with positive electrospray ionization in a single run. Samples were pretreated by liquid–liquid extraction with cyclohexane. The intra‐ and interday precision and accuracy of the assay were within acceptable ranges. Matrix effects for all of the analytes were between 90.16 and 100.21%. The average recovery ranged from 75.38 to 88.96%. This method was successfully applied to study the pharmacokinetic parameters of the four compounds in rat plasma after oral administration of Qianzhi capsules. Four quinones could be rapidly absorbed into blood (tmax, 0.80–1.93 h) and eliminated relatively slowly (t1/2, 8.07–11.97 h). The results might be helpful for guiding the clinical application of Qianzhi capsules in the future.
A novel sorbent based on carbon nanotube/amino‐functionalized sol–gel for the headspace solid‐phase microextraction of α‐bisabolol from medicinal plant samples using experimental design
Authors: Yarazavi Mina , Noroozian Ebrahim
Published: February 2018

A novel sol–gel coating on a stainless‐steel fiber was developed for the first time for the headspace solid‐phase microextraction and determination of α‐bisabolol with gas chromatography and flame ionization detection. The parameters influencing the efficiency of solid‐phase microextraction process, such as extraction time and temperature, pH, and ionic strength, were optimized by the experimental design method. Under optimized conditions, the linear range was between 0.0027 and 100 μg/mL. The relative standard deviations determined at 0.01 and 1.0 μg/mL concentration levels (n = 3), respectively, were as follows: intraday relative standard deviations 3.4 and 3.3%; interday relative standard deviations 5.0 and 4.3%; and fiber‐to‐fiber relative standard deviations 6.0 and 3.5%. The relative recovery values were 90.3 and 101.4% at 0.01 and 1.0 μg/mL spiking levels, respectively. The proposed method was successfully applied to various real samples containing α‐bisabolol.
Evaluation of solid‐phase extraction procedures for the quantitation of venlafaxine in human saliva by high‐performance liquid chromatography
Authors: Dziurkowska Ewelina , Wesolowski Marek
Published: February 2018

In recent years, the use of human saliva for diagnostic purposes has evoked great interest. Thus, the aim of this study was to choose the optimal solid‐phase extraction cartridges and extraction solvents for the quantitation of venlafaxine in saliva. Blank saliva samples spiked with venlafaxine concentrations between 25 and 750 ng/mL were analyzed using five solid‐phase extraction columns (C18, C8, Strata‐X, Strata‐X‐C, and Strata‐X‐AW), washing solvents (deionized water, phosphate buffer at pH 5.5, and their mixtures with methanol), and elution solvents (methanol, acetonitrile, and their mixtures with 25% ammonia). A high‐performance liquid chromatography system was used to quantify venlafaxine in saliva. The results of this study revealed that nine of 25 procedures enabled quantitation of venlafaxine in the tested concentration range. The procedure that used a C18 cartridge, a mixture of methanol and deionized water as the washing solvent, and methanol as the elution solvent was the most effective and allowed quantitation of all venlafaxine concentrations with an acceptable recovery. In contrast, the Strata‐X‐C cartridge could not detect venlafaxine at the lowest concentration (25 ng/mL). The data acquired from the high‐performance liquid chromatography system were confirmed by a multivariate data analysis.
The application of natural landform analogy and geology‐based spoil classification to improve surface stability of elevated spoil landforms in the Bowen Basin, Australia—A review
Authors: Emmerton Bevan , Burgess Jon , Esterle Joan , Erskine Peter , Baumgartl Thomas
Published: February 2018

Large‐scale open cut mining has occurred within the Bowen Basin for over 4 decades, transitioning from shallow mining depths and limited spoil elevation to increased mining depths, prestripping and increasingly elevated mesa‐like landforms.

As a result of this evolution, the stabilisation of modern constructed landforms is no longer assured through the establishment of vegetation alone. The selection of resilient fragmental spoil types for the construction of final landform surfaces, and as cladding for stabilising steep erosive batters, is a practical methodology that has the potential to significantly improve rehabilitation outcomes, by increasing surface rock cover, roughness, and infiltration and reducing erodibility. An understanding of the properties and behaviour of individual spoil materials disturbed during mining is required.

Relevant information from published literature on the geological origins, lithology, and weathering characteristics of individual strata within the Bowen Basin Coal Measures (and younger overlying weathered strata) has been reviewed, related to natural landforms and applied to the surface stability of major strata types when disturbed by mining.

A spoil classification derived from geological characteristics and weathering behaviour of identifiable lithologic components has been reviewed and refined, demonstrating the application of use of geological information.

This classification system is a tool for the allocation of spoil types and use of categories that have application in premine feasibility investigations, landform design, and material selection and placement. The logic of classifying materials based on their stability in the natural landscape has wider relevance to other mining areas where elevated landforms of sedimentary material are constructed.
Peat bog and alluvial deposits reveal land degradation during 16th‐ and 17th‐century colonisation of the Western Carpathians (Czech Republic)
Authors: Kapustová Veronika , Pánek Tomáš , Hradecký Jan , Zernitskaya Valentina , Hutchinson Simon M. , Mulková Monika , Sedláček Jan , Bajer Vojtěch
Published: February 2018

Wallachian (shepherd) colonisation of the upper parts of the Carpathians, the second largest mountain range in Europe, provides a unique opportunity to study human‐induced ecological changes and subsequent sediment mobilisation within slope and fluvial systems. The Wallachians came to the nearly pristine landscape in the Czech part of the Western Carpathians during the 16th to 17th century bringing large‐scale deforestation and grazing to the upper parts of its ridges. Despite the importance of this event, there is a lack of high‐resolution multiproxy reconstructions to help decipher the relative influence of anthropogenic and climate factors on this landscape. Here, we provide an approximately 2.1‐kyr record obtained from a peat bog where, using chronological, sedimentological, and pollen analyses, we were able to differentiate between environmental conditions before, during, and after colonisation. Prior to colonisation, climate deterioration following the onset of Little Ice Age caused changes in forest composition and erosion events (causing a ~ad 0–1500 gap in the record). Abrupt human‐induced deforestation detected in the pollen record, together with the abundant fine‐grained minerogenic content of peat deposits between ad ~1640 and ad 1870, corresponds to increased run‐off and sheet erosion on slopes, enhanced by Little Ice Age climate deterioration. The sedimentary record in alluvial deposits downstream indicates that the colonisation of the mountain slopes in this region not only had a local effect on soil degradation, but it also increased the net aggradation of overbank deposits within valley floors. After reforestation, net aggradation was replaced by river incision into alluvia.
Ants respond more strongly to grazing than changes in shrub cover
Authors: Radnan Gabriella N. , Eldridge David J.
Published: February 2018

Increases in the cover or density of woody plants (encroachment) and overgrazing by European livestock are 2 major drivers of ecosystem structure and function in drylands and are often associated with land degradation. Although the effects of encroachment and overgrazing on vascular plants are relatively well known, little is known about their effects on arthropods such as ants. We examined ant community composition at sites ranging in shrub cover in a wooded dryland in eastern Australia, testing the notion that increasing shrub cover and grazing intensity would alter ant assemblages and functional group composition. We used ants because they are abundant, diverse, and respond to small‐scale environmental changes. Increasing shrub cover had no effect on ant richness, diversity, or evenness but increased the abundance of Subordinate Camponotini. Larger shrubs tended to have greater ant richness, and abundance of Cold Climate Specialists, but fewer Generalized Myrmicinae and Hot Climate Specialists. More intense grazing was associated with greater ant richness, diversity, and evenness; a greater abundance of Hot Climate Specialists and Dominant Dolichoridae; and lower abundance of Subordinate Camponotini. Our study indicates that changes in grazing intensity had stronger effects on ant richness than any increase in shrub cover. The effects of grazing likely resulted from changes in soil surface complexity such as barer ground associated with grazing‐induced degradation.
Early response ofQuercus roburseedlings to soil compaction following germination
Authors: Cambi Martina , Mariotti Barbara , Fabiano Fabio , Maltoni Alberto , Tani Andrea , Foderi Cristiano , Laschi Andrea , Marchi Enrico
Published: February 2018

Logging operations using heavy machinery effect changes in soil characteristics due to compaction; such conditions can negatively influence seedling development. In stands managed on the basis of close‐to‐nature silviculture or continuous cover forestry, successful establishment of natural regeneration after logging is important to ensure the proper functioning of a forest ecosystem, to promote soil recovery, and to prevent and mitigate land degradation processes (such as soil erosion, mudflow, waterlogging, and landslides) related to soil compaction and rutting. This work aimed to assess the early response ofQuercus roburseedlings to soil compaction during the first 1.5 months after germination. The study was carried out in a controlled environment using 8 L containers filled with natural alluvial soil. Three levels of soil compaction were applied in a laboratory using a compression‐testing machine placed on the top surface of the soil in the containers. The morphological traits of the seedling shoot and root systems were analysed to compare 3 compaction levels. There were significant differences in seedling traits among the treatments, and they indicated that increasing levels of compaction reduced early seedling growth after emergence. Compaction had a larger impact on the root system, particularly the development at depth (root system depth, and main root length), compared with the shoot system. Our results suggest that compaction affects seedling root system growth following the first growth stages after germination; thus, compaction represents an additional critical factor for seedling establishment, particularly in environments where early growth is crucial for overcoming the dry season.
A Stereolithography‐Based 3D Printed Hybrid Scaffold for In Situ Cartilage Defect Repair
Authors: Aisenbrey Elizabeth A. , Tomaschke Andrew , Kleinjan Eric , Muralidharan Archish , Pascual‐Garrido Cecilia , McLeod Robert R. , Ferguson Virginia L. , Bryant Stephanie J.
Published: February 2018

Damage to articular cartilage can over time cause degeneration to the tissue surrounding the injury. To address this problem, scaffolds that prevent degeneration and promote neotissue growth are needed. A new hybrid scaffold that combines a stereolithography‐based 3D printed support structure with an injectable and photopolymerizable hydrogel for delivering cells to treat focal chondral defects is introduced. In this proof of concept study, the ability to a) infill the support structure with an injectable hydrogel precursor solution, b) incorporate cartilage cells during infilling using a degradable hydrogel that promotes neotissue deposition, and c) minimize damage to the surrounding cartilage when the hybrid scaffold is placed in situ in a focal chondral defect in an osteochondral plug that is cultured under mechanical loading is demonstrated. With the ability to independently control the properties of the structure and the injectable hydrogel, this hybrid scaffold approach holds promise for treating chondral defects.
Asymmetric Alkyl Side‐Chain Engineering of Naphthalene Diimide‐Based n‐Type Polymers for Efficient All‐Polymer Solar Cells
Authors: Jia Tao , Li Zhenye , Ying Lei , Jia Jianchao , Fan Baobing , Zhong Wenkai , Pan Feilong , He Penghui , Chen Junwu , Huang Fei , Cao Yong
Published: February 2018

The design and synthesis of three n‐type conjugated polymers based on a naphthalene diimide–thiophene skeleton are presented. The control polymer, PNDI‐2HD, has two identical 2‐hexyldecyl side chains, and the other polymers have different alkyl side chains; PNDI‐EHDT has a 2‐ethylhexyl and a 2‐decyltetradecyl side chain, and PNDI‐BOOD has a 2‐butyloctyl and a 2‐octyldodecyl side chain. These copolymers with different alkyl side chains exhibit higher melting and crystallization temperatures, and stronger aggregation in solution, than the control copolymer PNDI‐2HD that has the same side chain. Polymer solar cells based on the electron‐donating copolymer PTB7‐Th and these novel copolymers exhibit nearly the same open‐circuit voltage of 0.77 V. Devices based on the copolymer PNDI‐BOOD with different side chains have a power‐conversion efficiency of up to 6.89%, which is much higher than the 4.30% obtained with the symmetric PNDI‐2HD. This improvement can be attributed to the improved charge‐carrier mobility and the formation of favorable film morphology. These observations suggest that the molecular design strategy of incorporating different side chains can provide a new and promising approach to developing n‐type conjugated polymers.
Low‐Density Self‐Assembled Poly(N‐Isopropyl Acrylamide) Sponges with Ultrahigh and Extremely Fast Water Uptake and Release
Authors: Jiang Shaohua , Helfricht Nicolas , Papastavrou Georg , Greiner Andreas , Agarwal Seema
Published: February 2018

Poly(N‐isopropyl acrylamide) (PNIPAM) hydrogels are well known for their temperature‐dependent water uptake and release. Hence, they are ideal candidates for water management applications. However, efficiency and rate of water uptake and release, respectively, have to be optimized. Here, highly stable 3D PNIPAM sponges that show a sufficiently low density and high specific pore volume, required for maximizing the amount and rate of water absorption‐desorption, are presented. They are prepared by a top‐down approach based on freeze‐drying a dispersion of short crosslinked PNIPAM fibers coated with crosslinked PNIPAM. The sponges have low densities (4.10–21.04 mg cm−3), high porosities >98%, and high specific pore volumes in the range of 47–243 cm3 g−1 depending on the concentration of the dispersions. The sponges absorb high amounts of water (≈7000%) at temperatures below the lower critical solution temperature (LCST) of PNIPAM and can release more than 80% of the absorbed water above the LCST in less than 2 min. Moreover, the water‐swollen sponges are reversibly foldable, can be confined to different shapes, and have compressive elastic modulus below 10 Pa. Hence, these spongy materials are of interest not only for water management but also for biomedical applications, smart textiles, and catalysis.
Effect of load on tribofilms at the contact interface under dry sliding conditions at 500 °C
Authors: Saleem S.S. , Wani M.F.
Published: February 2018

This paper presents a study of the effect of load on the retention of the tribofilms formed at the interface of a dry sliding contact between exhaust valve material, Nimonic alloy (N 80A) and valve‐seat material, ductile cast iron (GGG‐40), at a temperature of 500 °C. The role of tribofilms in influencing friction and wear behaviour at elevated temperature is highlighted. Reciprocating pin‐on‐disc experiments were conducted using a hemispherical shaped pin sliding against a flat disc at 20 Hz oscillating frequency, 2 mm stroke at loads of 20 N to 50 N. Low coefficient of friction, in the range of 0.13 to 0.15, was observed at loads up to 40 N whereas at a load of 50 N, the average coefficient of friction increased to 0.29. Optical and scanning electron micrographs with energy dispersive spectroscopy analysis indicate evidence of formation and retention of well compacted and strongly adhering tribofilms at loads up to 40 N. At 50 N, even though more abrasive wear is seen, initial deterioration and subsequent reforming of the tribofilms with increasing sliding time is observed. Overall, more wear was observed for the valve‐seat material as compared to the valve material. Raman spectroscopy primarily indicates the presence of hematite on the worn surfaces at loads of 20 N to 40 N, whereas magnetite presence is strongest at the highest load of 50 N. Increase in tribofilm hardness was observed with increase in contact load whereas the thickness of the tribofilm was not significantly affected by the contact load.
Nigrostriatal dopamine transporter availability in early Parkinson's disease
Authors: Fazio Patrik , Svenningsson Per , Cselényi Zsolt , Halldin Christer , Farde Lars , Varrone Andrea
Published: February 2018

Background: The imaging of biomarkers for characterization of dopaminergic impairment in Parkinson's disease (PD) is useful for diagnosis, patient stratification, and assessment of treatment outcomes. [18F]FE‐PE2I is an improved imaging tool allowing for detailed mapping of the dopamine transporter protein in the nigro‐striatal system at the level of cell bodies (substantia nigra), axons, and presynaptic terminals (striatum).

Objectives: The objective of this study was to compare the dopamine transporter protein loss in the presynaptic terminals to that in the cell bodies and axons in early PD patients using [18F](E)‐N‐(3‐iodoprop‐2‐enyl)‐2b‐carbofluoroethoxy‐3b‐(4′‐methyl‐phenyl) nortropane ([18F]FE‐PE2I) and high‐resolution PET.

Methods: A total of 20 early PD patients (15 men/5 women, 62 ± 8 years) and 20 controls (15 men/5 women, 62 ± 7 years) underwent high‐resolution [18F]FE‐PE2I PET. Dopamine transporter protein availability was estimated for the different nigro‐striatal regions and expressed as nondisplaceable binding potential values.

Results: When compared with controls, the binding potential values in PD patients were reduced by 36% to 70% in presynaptic terminals and by 30% in cell bodies. Dopamine transporter availability along the tracts was not different between the 2 groups (controls 0.5 ± 0.1 vs PD 0.4 ± 0.1).

Conclusions: This is the first study that examines dopamine transporter protein availability in vivo within the entire nigro‐striatal pathway. The results suggest that at early stages of symptomatic PD a greater loss is observed at the level of the axonal terminals when compared with cell bodies and axons of dopaminergic neurons. The findings suggest a relative preservation of cell bodies in early PD, which might be relevant for novel disease‐modifying strategies. © 2018 International Parkinson and Movement Disorder Society
Ataxia‐telangiectasia: A review of movement disorders, clinical features, and genotype correlations
Authors: Levy Ariel , Lang Anthony E.
Published: February 2018

Ataxia‐telangiectasia is an autosomal recessive neurodegenerative disorder that was initially thought to present exclusively in childhood. With the discovery of the ATM gene, the phenotypic spectrum of the condition has expanded. This review elaborates the expanded phenomenology, including oculomotor apraxia and immunodeficiency, and estimates the presence of each movement disorder feature from previously reported literature. Initial manifestations of Ataxia‐telangiectasia include cerebellar symptoms (67%), dystonia (18%), choreoathetosis (10%), and tremor (4%), with parkinsonism and myoclonus not reported as initial features. The prevalence of movement disorders during the course of the disease includes cerebellar symptoms (96%), dystonia (89%), parkinsonism (41%), choreoathetosis (89%), myoclonus (92%), and tremor (74%). Phenomenology and age of onset is modulated by presence of residual ATM kinase activity, with genotypes heavily truncating the ATM protein associated with the most severe phenotypes. Ataxia‐telangiectasia commonly results in a spectrum of movement disorders beyond ataxia and telangiectasias. © 2018 International Parkinson and Movement Disorder Society
Effects of Temperature and Salinity on Early Ontogeny of Bigmouth Sleeper Larvae
Authors: Olivieri-Velázquez Karina M , Neal J Wesley
Published: February 2018

Declines in the abundance of Bigmouth Sleeper Gobiomorus dormitor within its range warrant directed conservation efforts, which may include population supplementation with hatchery-produced fish. However, previous attempts at Bigmouth Sleeper culture resulted in limited larval development and lack of successful exogenous feeding after yolk sac depletion, presumably in response to environmental conditions. The effects of temperature and salinity on hatch success, survival, growth, and development of Bigmouth Sleeper yolk sac larvae were examined in controlled, replicated experiments. Hatch success was greater at lower temperatures (23°C) and salinities (0, 5, and 10 g/L), larvae survived longer at lower temperatures (23 and 26°C), and growth metrics were greatest in freshwater (salinity = 0 g/L). Larvae held at salinities of 5 g/L and higher experienced 100% mortality within 12 h posthatch. Survival and development were inversely correlated and dependent on temperature; survival was greater at 23°C, but larvae developed slowly, while development was rapid at 29°C, yet all fish died by 48 h posthatch. The results suggests that the optimal hatching temperature and salinity for Bigmouth Sleeper is 23°C and 0 g/L, respectively, and the optimum rearing temperature for yolk sac larvae is 26°C. However, the amphidromous life history strategy of this species may require an increasing temperature and salinity regimen that mimics the environmental conditions larvae would experience following hatch during downstream transport from cooler freshwater streams to warmer brackish and marine waters in their natural habitats.
Risk of Malnutrition Evaluated by Mini Nutritional Assessment and Sarcopenia in Noninstitutionalized Elderly People
Authors: Liguori Ilaria , Curcio Francesco , Russo Gennaro , Cellurale Michele , Aran Luisa , Bulli Giulia , Della‐Morte David , Gargiulo Gaetano , Testa Gianluca , Cacciatore Francesco , Bonaduce Domenico , Abete Pasquale
Published: February 2018

Background

Malnutrition indices and muscle mass and strength in the elderly are poorly investigated. Moreover, malnutrition seems to be 1 of the more important factors in the cause of sarcopenia. The presence of sarcopenia and its relationship with malnutrition indices were studied in noninstitutionalized elderly people who underwent Comprehensive Geriatric Assessment (CGA).

Methods

A total of 473 elderly subjects (mean age, 80.9 ± 6.6 years) admitted to CGA were studied. Malnutrition risk was evaluated with Mini Nutritional Assessment (MNA) score, whereas muscle mass and muscle strength were evaluated by bioimpedentiometry and hand grip, respectively. Sarcopenia was assessed as indicated in the European Working Group on Sarcopenia in Older People (EWGSOP) consensus.

Results

Overall prevalence of sarcopenia was 13.1%, and it increased from 6.1% to 31.4% as MNA decreased (P < .001). MNA score was lower in elderly subjects with sarcopenia (15.4 ± 4.2) than without sarcopenia (22.0 ± 4.0) (P = .024). Linear regression analysis showed that MNA score is linearly related both with muscle mass (r = 0.72; P < .001) and strength (r = 0.42; P < .001). Multivariate analysis, adjusted for several confounding variables including comorbidity and disability, confirmed these results.

Conclusions

MNA score is low in noninstitutionalized elderly subjects with sarcopenia, and it is linearly related to muscle mass and muscle strength. These data indicate that MNA score, when evaluated with muscle mass and strength, may recognize elderly subjects with sarcopenia.
Variable prenatal presentation of Pfeiffer syndrome: Suggested aids to prenatal sonographic diagnosis
Authors: Saliba Souha , Morel Baptiste , Gonzales Marie , Sénat Marie‐Victoire , Guilbaud Lucie , Jouannic Jean‐Marie , Cassart Marie , Garel Catherine , Blondiaux Eléonore
Published: February 2018

Background

Our purpose was to describe and compare the cranial and extracranial abnormalities of Pfeiffer syndrome on prenatal imaging with postnatal or postmortem findings, which may help in prenatal diagnosis of Pfeiffer syndrome (PS).

Methods

Cases of fetuses with a confirmed diagnosis of PS over a 4‐year period (2012–2016) were retrospectively reviewed. Prenatal imaging findings, postnatal, or postmortem investigations and genetic test results were analyzed.

Results

Four fetuses were ascertained, 3 with prenatal sonographic findings compatible with PS and one only diagnosed at postmortem. Cases were referred between 22 and 24 weeks' gestation. Three of the 4 cases were terminated, and details of postmortem/postnatal examination were available in all. There was variable presentation of features. Craniosynostosis was present in 3 cases, but only detected prenatally in 2. Extracranial signs included abnormalities of thumbs and/or big toes, detected prenatally in 3 of the 4 cases. A sacral appendage and vertebral or coronal clefts were present at postmortem in 3 cases but only detected prenatally in one. A cartilaginous tracheal sleeve was detected at postmortem in all 3 cases but not detected by prenatal ultrasound. Other findings included ventriculomegaly, posterior fossa, and facial anomalies. Molecular testing revealed mutations of the fibroblast growth factor receptor 2 (FGFR2) gene in all cases.

Conclusion

Pfeiffer syndrome has a highly variable phenotype, and the absence of craniosynostosis on prenatal US does not exclude the diagnosis. Presence of abnormal thumbs and big toes, a sacral appendage, vertebral fusions, and coronal clefts should lead to prenatal molecular testing for PS.
When ultrasound anomalies are present: An estimation of the frequency of chromosome abnormalities not detected by cell‐free DNA aneuploidy screens
Authors: Reimers Rebecca M. , Mason‐Suares Heather , Little Sarah E. , Bromley Bryann , Reiff Emily S. , Dobson Lori J. , Wilkins‐Haug Louise
Published: February 2018

Objectives

This study characterizes cytogenetic abnormalities with ultrasound findings to refine counseling following negative cell‐free DNA (cfDNA).

Methods

A retrospective cohort of pregnancies with chromosome abnormalities and ultrasound findings was examined to determine the residual risk following negative cfDNA. Cytogenetic data was categorized as cfDNA detectable for aneuploidies of chromosomes 13, 18, 21, X, or Y or non‐cfDNA detectable for other chromosome abnormalities. Ultrasound reports were categorized as structural anomaly, nuchal translucency (NT) ≥3.0 mm, or other “soft markers”. Results were compared using chi squared and Fishers exact tests.

Results

Of the 498 fetuses with cytogenetic abnormalities and ultrasound findings, 16.3% (81/498) had non‐cfDNA detectable results. In the first, second, and third trimesters, 12.4% (32/259), 19.5% (42/215), and 29.2% (7/24) had non‐cfDNA detectable results respectively. The first trimester non‐cfDNA detectable results reduced to 7.7% (19/246) if triploidy was detectable by cfDNA testing. For isolated first trimester NT of 3.0–3.49 mm, 15.8% (6/38) had non‐cfDNA detectable results, while for NT ≥3.5 mm, it was 12.3% (20/162). For cystic hygroma, 4.3% (4/94) had non‐cfDNA detectable results.

Conclusions

Counseling for residual risk following cfDNA in the presence of an ultrasound finding is impacted by gestational age, ultrasound finding, and cfDNA detection of triploidy.
Fetal Doppler changes 1 week after endoscopic equatorial laser for twin‐to‐twin transfusion syndrome: A longitudinal study
Authors: Persico Nicola , D'Ambrosi Francesco , Fabietti Isabella , Boito Simona , Aiello Elisa , Bulfoni Alessandro , Ciralli Fabrizio , Kustermann Alessandra , Mosca Fabio , Fedele Luigi
Published: February 2018

Objective

To investigate sequential Doppler changes in donors and recipients before and 1 week after endoscopic laser for twin‐to‐twin transfusion syndrome (TTTS) and to examine factors that may be associated with such changes.

Methods

In TTTS pregnancies undergoing laser treatment, we examined fetal Doppler changes before and 1 week postintervention. Intrauterine death rates and preoperative factors were analyzed in relation to Doppler changes.

Results

Among 129 (85.4%) donors surviving at 1 week after laser, there was normalization of umbilical artery flow in 26 (72.2%) of 36 cases with preoperative abnormal Dopplers. In the remaining 10 (27.8%) fetuses, abnormal findings persisted. The rate of later intrauterine death was significantly higher in the latter group (6 of 10, 60.0%) compared with fetuses in which Doppler findings normalized (4 of 26, 15.4%; P < .05), with no difference in the rate of severe donor growth restriction between the 2 groups (80.0% vs 65.4%, respectively; P = .688).

Conclusions

In about 70% of TTTS donors with preoperative abnormal umbilical artery Doppler, there was normalization 1 week after endoscopic laser. The incidence of fetal growth restriction was not significantly different in donors with persistence of Doppler abnormalities compared with those with normalized findings.
Influences of the grafting percentage of natural rubber‐graft‐poly(2‐hydroxyethyl acrylate) on properties of its vulcanizates
Authors: Chueangchayaphan Wannarat , Chueangchayaphan Narong , Tanrattanakul Varaporn , Muangsap Suchanya
Published: February 2018

The graft copolymerization of 2‐hydroxyethyl acrylate (HEA) monomer onto natural rubber (NR) latex was successful using cumene hydroperoxide and tetraethylene pentamine as redox initiators. The grafting of poly(2‐hydroxyethyl acrylate) (PHEA) on the NR particles was confirmed by Fourier transform infrared spectroscopy, 1H NMR spectroscopy and TEM. The NR‐g‐PHEA with various grafting percentages (0%, 8.7%, 14.3% and 18.7%) was compounded on a two‐roll mill with a sulfur vulcanization system. The effects of grafting percentage on the cure characteristics, dielectric properties, thermal properties and physical properties of NR‐g‐PHEA vulcanizates were investigated. It was found that increased grafting caused NR‐g‐PHEA vulcanizates to have reduced water contact angle, scorch time and cure time, while the dielectric constant and dissipation factor increased. The NR‐g‐PHEA vulcanizate with 8.7% grafting exhibited the highest delta torque (MH − ML), crosslink density, tensile strength, moduli at 100%, 200% and 300% strains, and hardness, with insignificant loss of elongation at break in comparison to the other cases. © 2018 Society of Chemical Industry
Mindfulness‐based SEL programming to increase preservice teachers’ mindfulness and emotional competence
Authors: Garner Pamela W. , Bender Stacy L. , Fedor Megan
Published: February 2018

Eighty‐seven preservice teachers, some of whom had preschool teaching experience, were randomly assigned to an intervention that included training in breathing awareness meditation infused with social‐emotional learning (n = 43) or a control group that received training in (n = 44) in breathing awareness meditation only. Both groups showed an increase in mindfulness from pre‐ to posttest. However, as expected, dimensions of emotional competence improved more significantly for preservice teachers in the intervention group. Increases were also greater for participants with teaching experience. Both groups also increased in the belief that classroom misbehavior would result in negative cognitive and social costs to children, but a larger increase was observed for the intervention group. Implications for teacher preparation are discussed.
Identification of Native and Posttranslationally Modified HLA‐B*57:01‐Restricted HIV Envelope Derived Epitopes Using Immunoproteomics
Authors: Ramarathinam Sri H. , Gras Stephanie , Alcantara Sheilajen , Yeung Amanda W.S. , Mifsud Nicole A. , Sonza Secondo , Illing Patricia T. , Glaros Elias N. , Center Robert J. , Thomas Shane R. , Kent Stephen J. , Ternette Nicola , Purcell Damian F. J. , Rossjohn Jamie , Purcell Anthony W.
Published: February 2018

The recognition of pathogen‐derived peptides by T lymphocytes is the cornerstone of adaptive immunity, whereby intracellular antigens are degraded in the cytosol and short peptides assemble with class I human leukocyte antigen (HLA) molecules in the ER. These peptide‐HLA complexes egress to the cell surface and are scrutinized by cytotoxic CD8+ T‐cells leading to the eradication of the infected cell. Here, naturally presented HLA‐B*57:01 bound peptides derived from the envelope protein of the human immunodeficiency virus (HIVenv) are identified. HIVenv peptides are present at a very small percentage of the overall HLA‐B*57:01 peptidome (<0.1%) and both native and posttranslationally modified forms of two distinct HIV peptides are identified. Notably, a peptide bearing a natively encoded C‐terminal tryptophan residue is also present in a modified form containing a kynurenine residue. Kynurenine is a major product of tryptophan catabolism and is abundant during inflammation and infection. Binding of these peptides at a molecular level and their immunogenicity in preliminary functional studies are examined. Modest immune responses are observed to the modified HIVenv peptide, highlighting a potential role for kynurenine‐modified peptides in the immune response to HIV and other viral infections.