bluuebunny/crossref_metadata_2025 huggingface dataset:
Detailed Transabdominal Fetal Anatomic Scanning in the Late First Trimester Versus the Early Second Trimester of Pregnancy
Authors: Yagel Simcha , Cohen Sarah M. , Porat Shay , Daum Hagit , Lipschuetz Michal , Amsalem Hagai , Messing Baruch , Valsky Dan V.
Published: December 2014

Objectives

To compare visualization rates for early targeted organ scanning at gestational ages ranging from 11 weeks 3 days to 13 weeks 2 days versus 14 weeks 3 days to 16 weeks 2 days.

Methods

We conducted a prospective longitudinal study of patients who presented for nuchal translucency (NT) screening and targeted organ scanning. Extended targeted organ scanning, including the central nervous system, face and neck, chest, heart (including complete echocardiography), digestive system, abdominal wall, urinary system, skeleton, and umbilical cord with its insertion and placenta, was performed on gravidas in 2 age ranges. Uterine artery Doppler mapping was performed during the second scan. All cases were examined twice: once at NT screening (up to 13 weeks 2 days) and again in the early second trimester.

Results

A total of 408 women were recruited and scanned twice. Three abnormalities were diagnosed in the second scan that were not seen in the first: dysplastic long bones, tricuspid stenosis, and cleft lip (without palate involvement). None had chromosomal anomalies. Successful visualization rates in all organ systems exceeded 94% in the second trimester. At the first‐trimester scan, some systems had high success rates, whereas others were very low; eg, in the brain, the cerebellum and posterior fossa were visualized successfully approximately 50% of the time and the upper lip only approximately 10%. On fetal echocardiography, the 4‐chamber view and outflow tracts were imaged successfully approximately 40% of the time, and the kidneys approximately 35%. Uterine artery Doppler mapping was possible in all patients on at least one side. On third‐trimester follow‐up, we diagnosed 1 mild pulmonary stenosis, 1 autosomal recessive polycystic kidney disease, and 1 ventricular septal defect.

Conclusions

The early second‐trimester scan was much more productive than targeted organ scanning performed during the NT window. When counseling women regarding the optimal time for early transabdominal targeted organ scanning, successful visualization rates for various organ systems should be considered.
Factors Affecting the Feasibility of Routine First‐Trimester Fetal Echocardiography
Authors: Nemescu Dragos , Onofriescu Mircea
Published: December 2014

Objectives

The purpose of our study was to assess the factors that may improve the feasibility of routine fetal echocardiography at the time of the first‐trimester scan.

Methods

In this prospective study, we included 616 healthy singleton fetuses. Examinations were performed transabdominally by a single sonographer at the beginning of his training in first‐trimester screening. The fetal heart was examined by high‐definition color Doppler imaging to obtain the 4‐chamber view, right and left ventricular outflow tracts, and 3‐vessel and trachea view. Logistic regression was used to investigate the effect on the ability to visualize different cardiac structures.

Results

The frequency of successful heart examinations increased significantly with the number of scans performed (P < .05). The sonographer needed 180 examinations before he could successfully examine the heart in at least 80% of cases. Significant factors that increased the probability of adequate echocardiography were the length of the heart examination and the experience of the sonographer (P< .05) but not transducer‐heart distance, maternal body mass index, fetal crown‐rump length, placenta interposition, or restrictive fetal position. Visualization of the left ventricular outflow tract could be improved by increasing the experience of the sonographer and decreasing the transducer‐heart distance. Also, visualization of the 3‐vessel and trachea view depended on the length of the heart examination, the experience of the sonographer, an anterior position of the placenta, and a restrictive fetal position.

Conclusions

Competence in color flow mapping assessment of the fetal heart at gestational ages of 11 weeks to 13 weeks 6 days is achieved only after extensive supervised training.
A Taller‐Than‐Wide Shape Is a Good Predictor of Papillary Thyroid Carcinoma in Small Solid Nodules
Authors: Ren Jie , Liu Bin , Zhang Li-Li , Li Hong-Yu , Zhang Fan , Li Shuang , Zhao Li-Rong
Published: December 2014

Objectives

The purpose of this study was to evaluate whether a nodule with a taller‐than‐wide shape (ie, an anteroposterior diameter that is longer than the transverse diameter on a transverse or longitudinal plane [anteroposterior‐to‐transverse ratio] >1) is a good predictor of papillary thyroid carcinoma (PTC) according to nodule size.

Methods

We retrospectively examined 207 thyroid nodules in our hospital from September 2011 to February 2013. Nodules were divided into groups by size: small (≤0.5 cm; group A), medium (0.5–1 cm; group B), and large (>1 cm; group C). Sonographic features were defined as an anteroposterior‐to‐transverse ratio greater than 1, microcalcifications, blurred margins, and hypoechogenicity.

Results

An anteroposterior‐to‐transverse ratio greater than 1 was the most accurate sonographic feature for predicting PTC in small nodules, with high sensitivity (81.4%) and specificity (96.8%), but it was not accurate in large nodules (>1 cm). Microcalcifications showed higher sensitivity (P< .05) in large nodules (60.0%) than in small ones (27.9%). Hypoechogenicity and blurred margins showed high sensitivity (95.3% and 97.7%, respectively) but low specificity (19.4% and 29.9%) for diagnosis of PTC in small thyroid nodules. An anteroposterior‐to‐transverse ratio greater than 1 in conjunction with another sonographic feature achieved the highest diagnostic accuracy in small nodules.

Conclusions

The predictive values of sonographic features depend on nodule size. An anteroposterior‐to‐transverse ratio greater than 1, especially in conjunction with another sonographic risk factor, showed superior performance for PTC diagnosis in small nodules.
A Novel Approach to Patient Self‐Monitoring of Sonographic Examinations Using a Head‐Mounted Display
Authors: Inoue Masaharu , Kihara Kazunori , Yoshida Soichiro , Ito Masaya , Takeshita Hideki , Ishioka Junichiro , Matsuoka Yoh , Numao Noboru , Saito Kazutaka , Fujii Yasuhisa
Published: December 2014

Objectives

Patients' use of a head‐mounted display during their sonographic examinations could provide them with information about their diseases in real time and might help improve “patient‐centered care.” We conducted this prospective study to evaluate the feasibility of a modern head‐mounted display for patient self‐monitoring of sonographic examinations.

Methods

In November and December 2013, 58 patients were enrolled. Patients wore a head‐mounted display (HMZ‐T2; Sony Corporation, Tokyo, Japan) during their sonographic examinations and watched their own images in real time. After the sonographic examinations, the patients completed a questionnaire, in which they evaluated the utility of the head‐mounted display, their understanding of their diseases, their satisfaction with using the head‐mounted display, and any adverse events. Until November 26, 2013, patients' names were requested on the questionnaire; after that date, the questionnaire was changed to be anonymous.

Results

Of the 58 patients, 56 (97%) elected to participate in this study. The head‐mounted display was reported to have good image quality by 42 patients (75%) and good wearability by 39 (70%). Thirty‐six patients (64%) reported they had deepened their understanding of their diseases. There were no major complications, and only 2 patients (4%) had mild eye fatigue. There was no significant association between questionnaire results and patient characteristics. None of the questionnaire results changed significantly after the questionnaire was made anonymous.

Conclusions

The use of a modern head‐mounted display by patients during sonographic examinations provided good image quality with acceptable wearability. It could deepen their understanding of their diseases and help develop patient‐centered care.
Differentiation of Metastatic Cervical Lymph Nodes With Ultrasound Elastography by Virtual Touch Tissue Imaging
Authors: Che Dehong , Zhou Xianli , Sun Mei-Ling , Wang Xiao , Jiang Zhaopeng , Changjun-Wu
Published: December 2014

Objectives

The purpose of this study was to investigate the clinical usefulness of acoustic radiation force impulse elastography for the differential diagnosis of cervical lymph nodes.

Methods

Virtual touch tissue imaging (Siemens Medical Solutions, Mountain View, CA) was analyzed in 81 patients (mean age, 46.6 years; range, 5–82 years) with 81 lymph nodes (45 metastatic nodes and 36 benign nodes).

Results

Most benign lymph nodes were slightly darker or the same in brightness compared with surrounding tissue, whereas most metastatic nodes were obviously darker. The mean area ratio of benign lymph nodes ± SD (1.05 ± 0.15) was statistically lower than the mean area ratio of metastatic lymph nodes (1.39 ± 0.20; P < 0.001). The area ration cutoff level for metastatic lymph nodes was estimated to be 1.16. With the use of a receiver operating characteristic curve with this cutoff value, the area ratio predicted malignancy with sensitivity of 91.1%, specificity of 83.3%, and an area under the curve of 0.925.

Conclusions

Acoustic radiation force impulse imaging is feasible for cervical lymph nodes. The Virtual Touch tissue imaging technique can complement conventional sonography, thereby making it easier to diagnose cervical lymph nodes.
Effects of Ultrasound Implementation on Physical Examination Learning and Teaching During the First Year of Medical Education
Authors: Dinh Vi Am , Frederick Jon , Bartos Rebekah , Shankel Tamara M. , Werner Leonard
Published: December 2014

Objectives

Increasing emphasis has been placed on point‐of‐care ultrasound in medical school. The overall effects of ultrasound curriculum implementation on the traditional physical examination skills of medical students are still unknown. We studied the effects on the Objective Standardized Clinical Examination (OSCE) scores of year 1 medical students before and after ultrasound curriculum implementation.

Methods

An ultrasound curriculum was incorporated into the physical diagnosis course for year 1 medical students in the 2012–2013 academic year. We performed a prospective observational study comparing traditional OSCE scores of year 1 medical students exposed to the ultrasound curriculum (post‐ultrasound) versus historic year 1 medical student controls (pre‐ultrasound) with no ultrasound exposure. Questionnaire data were also obtained from year 1 medical students and physical diagnosis faculty to assess attitudes toward ultrasound implementation.

Results

The final overall OSCE scores were graded with a 5‐point Likert‐type scale from unsatisfactory to outstanding. There was a significant increase in outstanding scores in the post‐ultrasound compared to the pre‐ultrasound group (27.0% versus 10.9%; P< .001). The post‐ultrasound group had significantly (P< .05) increased first‐time pass rates on blood pressure measurements, the abdominal examination, and professionalism. Student and physical diagnosis faculty questionnaire data showed an overall positive response, with most agreeing or strongly agreeing that ultrasound should be included in the future year 1 medical student curriculum.

Conclusions

Ultrasound implementation into a physical diagnosis curriculum for year 1 medical students is feasible and may improve their overall traditional physical examination skills.
Dynamic High‐Resolution Sonography Compared to Magnetic Resonance Imaging for Diagnosis of Temporomandibular Joint Disk Displacement
Authors: Habashi Hadeel , Eran Ayelet , Blumenfeld Israel , Gaitini Diana
Published: December 2014

Objectives

The purpose of this study was to determine the value of dynamic high‐resolution sonography for evaluation of temporomandibular joint (TMJ) disk displacement compared to magnetic resonance imaging (MRI) with the mouth closed and during the maximal mandibular range of motion.

Methods

Dynamic high‐resolution sonography with the mouth closed and during the maximal mandibular range of motion was performed on 39 consecutive patients (78 joints; 13 male and 26 female; age range, 18–77 years; mean age ± SD, 37.23 ± 16.26 years) with TMJ disorders. A TMJ MRI study was performed 1 to 7 days after sonography. We searched for signs of disk displacement and findings compatible with degenerative joint disease. Both studies were performed and interpreted independently by blinded operators.

Results

Magnetic resonance imaging depicted 22 normal joints (28.2%), 21 (26.9%) with anterior disk displacement with reduction, 15 (19.2%) with anterior disk displacement without reduction, and 20 (25.6%) with degenerative disease. Sonography depicted 30 normal joints (38.5%), 22 (28.2%) with anterior disk displacement with reduction, 12 (15.4%) with anterior disk displacement without reduction, and 14 (17.9%) with degenerative disease. The overall sensitivity, specificity, and accuracy of sonography for diagnosis of disk displacement were 74.3%, 84.2%, and 77.7%, respectively. The sensitivity, specificity, and accuracy for diagnosis of disk displacement with reduction were 78.6%, 66.7%, and 73.0%, and the values for diagnosis of disk displacement without reduction were 66.7%, 78.6%, and 73.0%.

Conclusions

Dynamic high‐resolution sonography is a potential imaging method for diagnosis of TMJ disk displacement and degenerative diseases. Further studies are needed to make dynamic high‐resolution sonography the first‐line test for diagnosis of TMJ disk displacement.
Sonographically Guided Posterior Subtalar Joint Injections via the Sinus Tarsi Approach
Authors: Smith Jay , Maida Eugene , Murthy Naveen S. , Kissin Eugene Y. , Jacobson Jon A.
Published: December 2014

Objectives

To determine the feasibility and accuracy of sonographically guided posterior subtalar joint (PSTJ) injections performed through the sinus tarsi.

Methods

A single experienced operator completed 10 sonographically guided PSTJ injections via the sinus tarsi on 10 unembalmed cadaveric ankle‐foot specimens. Injections were performed using a 17–5‐MHz linear transducer, a 25‐gauge, 50‐mm needle, and an out‐of‐plane, anterior‐to‐posterior needle trajectory parallel to the calcaneal surface. Sonographic assessment for fluid in the posterior and lateral PSTJ recesses, sinus tarsi, and peroneal tendon sheath was performed before and after injections of 2 and 4 mL of tap water. Two additional specimens were injected with a contrast agent: 1 via the sonographically guided approach and another by a computed tomographically guided approach.

Results

All 10 sonographically guided PSTJ tap water injections were accurate, distending both the posterior and lateral PSTJ recesses. In addition, all 10 specimens showed posterior recess distension by 2 mL, whereas only 2 specimens (20%) showed lateral recess distension at this volume. By 4 mL, both recesses were clearly distended in all specimens. Both contrast agent injections produced similar PSTJ computed tomographic arthrograms and patterns of recess distension similar to the sonographically guided tap water injections. No sonographically guided PSTJ injection placed fluid in the peroneal tendon sheath.

Conclusions

Sonographically guided PSTJ injections via the sinus tarsi can accurately and specifically deliver injectate into the PSTJ while monitoring injectate flow within the posterior recess. The sinus tarsi approach may be used as an alternative technique to perform sonographically guided PSTJ injections when clinically appropriate.
Quantitative Assessment of Mitral Inflow and Aortic Outflow Stroke Volumes by 3‐Dimensional Real‐time Full‐Volume Color Flow Doppler Transthoracic Echocardiography
Authors: Shimada Eriko , Zhu Meihua , Kimura Sumito , Streiff Cole , Houle Helene , Datta Saurabh , Sahn David J. , Ashraf Muhammad
Published: December 2014

Objectives

Noninvasive quantification of left ventricular (LV) stroke volumes has an important clinical role in assessing circulation and monitoring therapeutic interventions for cardiac disease. This study validated the accuracy of a real‐time 3‐dimensional (3D) color flow Doppler method performed during transthoracic echocardiography (TTE) for quantifying volume flows through the mitral and aortic valves using a dedicated offline 3D flow computation program compared to LV sonomicrometry in an open‐chest animal model.

Methods

Forty‐six different hemodynamic states in 5 open‐chest pigs were studied. Three‐dimensional color flow Doppler TTE and 2‐dimensional (2D) TTE were performed by epicardial scanning. The dedicated software was used to compute flow volumes at the mitral annulus and the left ventricular outflow tract (LVOT) with the 3D color flow Doppler method. Stroke volumes by 2D TTE were computed in the conventional manner. Stroke volumes derived from sonomicrometry were used as reference values.

Results

Mitral inflow and LVOT outflow derived from the 3D color flow Doppler method correlated well with stroke volumes by sonomicrometry (R = 0.96 and 0.96, respectively), whereas correlation coefficients for mitral inflow and LVOT outflow computed by 2D TTE and stroke volumes by sonomicrometry were R = 0.84 and 0.86. Compared to 2D TTE, the 3D method showed a smaller bias and narrower limits of agreement in both mitral inflow (mean ± SD: 3D, 2.36 ± 2.86 mL; 2D, 10.22 ± 8.46 mL) and LVOT outflow (3D, 1.99 ± 2.95 mL; 2D, 4.12 ± 6.32 mL).

Conclusions

Real‐time 3D color flow Doppler quantification is feasible and accurate for measurement of mitral inflow and LVOT outflow stroke volumes over a range of hemodynamic conditions.
Graphene: Synthesis, Characterization, and Applications
Authors: Zhou Kai‐Ge , Zhang Hao‐Li
Published: December 2014

Since the breakthrough work by Geim and Novosolov in 2004, the investigation on graphene has grown as a result of graphene's unique electronic, mechanical, and chemical properties. To characterize single‐layer graphene, interfacial diffraction‐induced color difference was the first milestone in the graphene adventure, and then Raman spectroscopy, scanning probe microscopy, and transmission electron microscopy were used to identify the graphene layers. Apart from the Scotch tap legend, the massive production of graphene is important for graphene research and applications. The current preparation methods can be classified into top‐down (eg, chemical intercalation and liquid exfoliation) and bottom‐up (eg, chemical vapor deposition and, chemical total synthesis) strategies. The massive production of graphene has enabled researchers to explore graphene in a variety of applications, for instance, energy conversion and storage, sensor, reinforcement, catalysis, separation, and so on. Meanwhile, inspired by the legend of graphene, other layered materials are being investigated. Challenges and future perspectives in the studies of graphene and other quasi‐two‐dimensional nanomaterials are discussed.
Paleolatitudes of the Tibetan Himalaya from primary and secondary magnetizations of Jurassic to Lower Cretaceous sedimentary rocks
Authors: Huang Wentao , van Hinsbergen Douwe J. J. , Dekkers Mark J. , Garzanti Eduardo , Dupont‐Nivet Guillaume , Lippert Peter C. , Li Xiaochun , Maffione Marco , Langereis Cor G. , Hu Xiumian , Guo Zhaojie , Kapp Paul
Published: December 2014

The Tibetan Himalaya represents the northernmost continental unit of the Indian plate that collided with Asia in the Cenozoic. Paleomagnetic studies on the Tibetan Himalaya can help constrain the dimension and paleogeography of “Greater India,” the Indian plate lithosphere that subducted and underthrusted below Asia after initial collision. Here we present a paleomagnetic investigation of a Jurassic (limestones) and Lower Cretaceous (volcaniclastic sandstones) section of the Tibetan Himalaya. The limestones yielded positive fold test, showing a prefolding origin of the isolated remanent magnetizations. Detailed paleomagnetic analyses, rock magnetic tests, end‐member modeling of acquisition curves of isothermal remanent magnetization, and petrographic investigation reveal that the magnetic carrier of the Jurassic limestones is authigenic magnetite, whereas the dominant magnetic carrier of the Lower Cretaceous volcaniclastic sandstones is detrital magnetite. Our observations lead us to conclude that the Jurassic limestones record a prefolding remagnetization, whereas the Lower Cretaceous volcaniclastic sandstones retain a primary remanence. The volcaniclastic sandstones yield an Early Cretaceous paleolatitude of 55.5°S [52.5°S, 58.6°S] for the Tibetan Himalaya, suggesting it was part of the Indian continent at that time. The size of “Greater India” during Jurassic time cannot be estimated from these limestones. Instead, a paleolatitude of the Tibetan Himalaya of 23.8°S [21.8°S, 26.1°S] during the remagnetization process is suggested. It is likely that the remagnetization, caused by the oxidation of early diagenetic pyrite to magnetite, was induced during 103–83 or 77–67 Ma. The inferred paleolatitudes at these two time intervals imply very different tectonic consequences for the Tibetan Himalaya.
Kappa distribution in the presence of a potential energy
Authors: Livadiotis George
Published: December 2014

The present paper develops the theory and formulations of the kappa distributions that describe particle systems characterized by a nonzero potential energy. As yet, kappa distributions were used for the statistical description of the velocity or kinetic energy of particles but not of the potential energy. With the results provided here, it is straightforward to use the developed kappa distributions to describe any particle population of space plasmas subject to a nonnegligible potential energy. Starting from the kappa distribution of the Hamiltonian function, we develop the distributions that describe either the complete phase space or the marginal spaces of positions and velocities. The study shows, among others: (a) The kappa distributions of velocities that describe space plasmas can be vastly different from the standard formulation of the kappa distribution, because of the presence of a potential energy; the correct formulation should be given by the marginal kappa distribution of velocities by integrating the distribution of the Hamiltonian over the potential energy. (b) The long‐standing problem of the divergence of the Boltzmannian exponential distribution for bounded radial potentials is solved using kappa distributions of negative kappa index. (c) Anisotropic distributions of velocities can exist in the presence of a velocity‐dependent potential. (d) A variety of applications, including derivations/verifications of the following: (i) the Jeans', the most frequent, and the maximum radii in spherical/linear gravitational potentials; (ii) the Virial theorem for power law potentials; (iii) the generalized barometric formula, (iv) the plasma density profiles in Saturnian magnetosphere, and (v) the average electron magnetic moment in Earth's magnetotail.
North Aegean core complexes, the gravity spreading of a thrust wedge
Authors: Kydonakis Konstantinos , Brun Jean‐Pierre , Sokoutis Dimitrios
Published: December 2014

The North Aegean core complexes developed in middle Eocene soon after the end of continental block convergence and piling up of the Hellenic Thrust Wedge. They formed during back‐arc extension, driven by the Hellenic slab rollback, at the back of the thrust wedge. A series of scaled laboratory experiments was performed to test whether the gravity spreading of a thrust wedge is a suitable process for the development of the North Aegean core complexes during back‐arc extension. Wedge‐shaped sand‐silicon models with variable boundary displacement velocities and different geometries of the upper sand layer were used to study the effects of variations in wedge rheology on the pattern of extension. The models exemplify that extension, either distributed (wide rift mode) or localized (core complex mode), is always located at the wedge rear. Core complex development was favored in models with thicker brittle layer (higher frictional strength) and low stretching rate (lower ductile strength). Both core complex location at the wedge rear and detachment location and dip are interdependent and intrinsically related to the initial wedge shape of the extending system. The experimental model displays striking similarities with the extensional pattern of the North Aegean in terms of (i) location, size, and shape of core complexes as well as their sequence of development and (ii) detachment location and dip. We conclude that it is the initial wedge geometry of the system and the weak nature of the crust at the onset of extension that controlled the extensional pattern of the North Aegean domain.
Lanthanide Terpyridine‐Based Assemblies: Towards Dual Luminescent Probes
Authors: Molloy Jennifer K. , Pillai Zeena , Sakamoto Junji , Ceroni Paola , Bergamini Giacomo
Published: December 2014

A tetrahedral shape‐persistent molecule equipped with four terpyridine ligands can form an oligomeric structure upon complexation with metal ions, in which two terpyridine units are intermolecularly connected via a metal ion. The most interesting results were obtained upon binding of lanthanide ions, whose luminescence is sensitized by the ligand. In particular, dual luminescent probes were obtained upon concomitant complexation of two different lanthanide ions, such as EuIII and NdIII.
Palladium‐Catalyzed Oxidative CC Bond Cleavage of α‐Hydroxyketones: Application to CH Acylation of Azoarenes and Synthesis of a Liver(X) Receptor Agonist
Authors: Majhi Biju , Ahammed Sabir , Kundu Debasish , Ranu Brindaban C.
Published: December 2014

Palladium‐catalyzed oxidative CC cleavage of α‐hydroxyketones and 2‐aryl acetophenones in the presence of tert‐butyl hydrogen peroxide (TBHP) generates an acyl moiety, which promotes subsequent regioselective CH acylation producing a series of ortho‐acyl substituted symmetrical and unsymmetrical azoarenes. This protocol is successfully used for the synthesis of liver (X) receptor agonist.
Total Synthesis of (−)‐Lundurine A and Determination of its Absolute Configuration
Authors: Jin Shuaijiang , Gong Jing , Qin Yong
Published: December 2014

A 15‐step total synthesis of (−)‐lundurine A (1) from easily accessible (S)‐pyrrolidinone 18 is reported. A Simmons‐Smith reaction allows the efficient, simultaneous assembly of the cyclopropyl C ring, the six‐membered D ring, the seven‐membered E ring, and the quaternary carbon stereocenters at C2 and C7. The absolute configuration of natural (−)‐lundurine A was deduced to be 2R,7R,20R based on the stepwise construction of the stereocenters during the total synthesis.
Visualization and Quantification of Transmembrane Ion Transport into Giant Unilamellar Vesicles
Authors: Valkenier Hennie , López Mora Néstor , Kros Alexander , Davis Anthony P.
Published: December 2014

Transmembrane ion transporters (ionophores) are widely investigated as supramolecular agents with potential for biological activity. Tests are usually performed in synthetic membranes that are assembled into large unilamellar vesicles (LUVs). However transport must be followed through bulk properties of the vesicle suspension, because LUVs are too small for individual study. An alternative approach is described whereby ion transport can be revealed and quantified through direct observation. The method employs giant unilamellar vesicles (GUVs), which are 20–60 μm in diameter and readily imaged by light microscopy. This allows characterization of individual GUVs containing transporter molecules, followed by studies of transport through fluorescence emission from encapsulated indicators. The method provides new levels of certainty and relevance, given that the GUVs are similar in size to living cells. It has been demonstrated using a highly active anion carrier, and should aid the development of compounds for treating channelopathies such as cystic fibrosis.
A High‐Temperature Molecular Ferroelectric Zn/Dy Complex Exhibiting Single‐Ion‐Magnet Behavior and Lanthanide Luminescence
Authors: Long Jérôme , Rouquette Jérôme , Thibaud Jean‐Marc , Ferreira Rute A. S. , Carlos Luís D. , Donnadieu Bruno , Vieru Veaceslav , Chibotaru Liviu F. , Konczewicz Leszek , Haines Julien , Guari Yannick , Larionova Joulia
Published: December 2014

Multifunctional molecular ferroelectrics are exciting materials synthesized using molecular chemistry concepts, which may combine a spontaneous electrical polarization, switched upon applying an electric field, with another physical property. A high‐temperature ferroelectric material is presented that is based on a chiral Zn2+/Dy3+ complex exhibiting Dy3+ luminescence, optical activity, and magnetism. We investigate the correlations between the electric polarization and the crystal structure as well as between the low‐temperature magnetic slow relaxation and the optical properties.
Synthesis of Mixed Silylene–Carbene Chelate Ligands from N‐Heterocyclic Silylcarbenes Mediated by Nickel
Authors: Tan Gengwen , Enthaler Stephan , Inoue Shigeyoshi , Blom Burgert , Driess Matthias
Published: December 2014

The NiII‐mediated tautomerization of the N‐heterocyclic hydrosilylcarbene L2Si(H)(CH2)NHC 1, where L2=CH(CCH2)(CMe)(NAr)2, Ar=2,6‐iPr2C6H3; NHC=3,4,5‐trimethylimidazol‐2‐yliden‐6‐yl, leads to the first N‐heterocyclic silylene (NHSi)–carbene (NHC) chelate ligand in the dibromo nickel(II) complex [L1Si:(CH2)(NHC)NiBr2] 2 (L1=CH(MeCNAr)2). Reduction of 2 with KC8 in the presence of PMe3 as an auxiliary ligand afforded, depending on the reaction time, the N‐heterocyclic silyl–NHC bromo NiII complex [L2Si(CH2)NHCNiBr(PMe3)] 3 and the unique Ni0 complex [η2(Si‐H){L2Si(H)(CH2)NHC}Ni(PMe3)2] 4 featuring an agostic SiH→Ni bonding interaction. When 1,2‐bis(dimethylphosphino)ethane (DMPE) was employed as an exogenous ligand, the first NHSi–NHC chelate‐ligand‐stabilized Ni0 complex [L1Si:(CH2)NHCNi(dmpe)] 5 could be isolated. Moreover, the dicarbonyl Ni0 complex 6, [L1Si:(CH2)NHCNi(CO)2], is easily accessible by the reduction of 2 with K(BHEt3) under a CO atmosphere. The complexes were spectroscopically and structurally characterized. Furthermore, complex 2 can serve as an efficient precatalyst for Kumada–Corriu‐type cross‐coupling reactions.
Application of Fragment‐Based Screening to the Design of Inhibitors of Escherichia coli DsbA
Authors: Adams Luke A. , Sharma Pooja , Mohanty Biswaranjan , Ilyichova Olga V. , Mulcair Mark D. , Williams Martin L. , Gleeson Ellen C. , Totsika Makrina , Doak Bradley C. , Caria Sofia , Rimmer Kieran , Horne James , Shouldice Stephen R. , Vazirani Mansha , Headey Stephen J. , Plumb Brent R. , Martin Jennifer L. , Heras Begoña , Simpson Jamie S. , Scanlon Martin J.
Published: December 2014

The thiol‐disulfide oxidoreductase enzyme DsbA catalyzes the formation of disulfide bonds in the periplasm of Gram‐negative bacteria. DsbA substrates include proteins involved in bacterial virulence. In the absence of DsbA, many of these proteins do not fold correctly, which renders the bacteria avirulent. Thus DsbA is a critical mediator of virulence and inhibitors may act as antivirulence agents. Biophysical screening has been employed to identify fragments that bind to DsbA from Escherichia coli. Elaboration of one of these fragments produced compounds that inhibit DsbA activity in vitro. In cell‐based assays, the compounds inhibit bacterial motility, but have no effect on growth in liquid culture, which is consistent with selective inhibition of DsbA. Crystal structures of inhibitors bound to DsbA indicate that they bind adjacent to the active site. Together, the data suggest that DsbA may be amenable to the development of novel antibacterial compounds that act by inhibiting bacterial virulence.
Novel nonammonia preservative for concentrated natural rubber latex
Authors: Wang Ting , Gui Hong‐Xing , Zhang Wen‐Fei , Zhang Ke‐Xi , Yu Wei‐Qiang , Li Yi‐Min , Zeng Ri‐Zhong , Huang Mao‐Fang
Published: December 2014

A derivative of sym‐triazine (HTT) was chosen as a new nonammonia preservative for concentrated natural rubber latex (CNRL) in place of NH3–TT/zinc oxide (ZnO). The preservation effects of the HTT for CNRL, drying characteristics, mechanical properties, and cytotoxicity of the vulcanized natural rubber (NR) film were investigated. The results show that the CNRL was preserved steadily for more than 6 months with 0.3% HTT, and the volatile fatty acid number, viscosity, and mechanical stability of CNRL all met the requirements of ISO 2004:2010(E). The drying characteristics of the vulcanized NR film preserved by HTT retained no change compared with those of the film preserved by NH3–TT/ZnO. The tensile strength and elongation at break of the vulcanized NR film preserved by HTT were 32.17 MPa and 853.80%, respectively; these were very similar to those of the film preserved by NH3–TT/ZnO, whereas the tear strength reached 68.43 kN/m, and this was much higher than that by NH3–TT/ZnO. The results of the cytotoxicity and dermal irritation tests prove that HTT is not especially harmful to humans. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41749.
Making polymeric membranes antifouling via “grafting from” polymerization of zwitterions
Authors: Li Qian , Imbrogno Joseph , Belfort Georges , Wang Xiao‐Lin
Published: December 2014

Protein‐fouling of membranes has negative effects on the wide applications of membrane materials, such as poly(vinylidene fluoride) (PVDF), poly(ether sulfone) (PES)/polysulfone (PSf). Zwitterionic materials have recently been used and identified from high throughput screens of large libraries of monomers to modify membranes due to their stable anti‐protein‐fouling properties. “Grafting from” polymerization is a technique involving monomers that are polymerized using an initiation reaction on the membrane surface. It is regarded as a simple, useful, and versatile modification approach to increase the anti‐fouling properties of a membrane. This strategy provides controllable introduction of graft chains with a high density and a long‐term chemical stability due to covalent attachment of graft chains. Graft density, chemistry, chain length, and conformation are all important parameters that need to be considered. This article presents a mini‐review of recent progress on the “grafting from” polymerization of zwitterionic monomers on the surfaces of PVDF and PES/PSf membranes, including an introduction of zwitterions and methods of graft polymerization. Various approaches such as free radical graft polymerization, photo‐induced graft polymerization, and plasma‐induced graft polymerization were compared based on uniformity and amount of grafted zwitterionic polymer, relative flux of modified membranes, simplicity and environment pollution of operation, and cost of technique. The application of different approaches and the performance of poly(zwitterion)‐grafted PVDF and PES/PSf membranes are summarized according to recent research. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41781.
Matrix influence on the piezoelectric properties of piezoelectric ceramic/polymer composite exhibiting particle alignment
Authors: Mamada Shogo , Yaguchi Naoyuki , Hansaka Masanori , Yamato Masafumi , Yoshida Hirohisa
Published: December 2014

This study was addressed to the influence of an electric field strength applied at fabrication process and matrix properties, such as the dielectric constant and the Young's modulus, on “pseudo‐1‐3 piezoelectric ceramic/polymer composite” in order to further enhance the piezoelectricity of that. The pseudo‐1‐3 piezoelectric ceramic/polymer composite consists of linearly ordered piezoelectric ceramic particles in polymer material. Silicone gel, silicone rubber, urethane rubber, and poly‐methyl‐methacrylate, which exhibit different dielectric constants and Young's modulus, were used as matrices to evaluate the matrix influence. The piezoelectricity of the pseudo‐1‐3 piezoelectric ceramic/polymer composite was evaluated using the piezoelectric strain constant d33. The d33 is one of the indices of the piezoelectric properties for piezoelectric materials. As a result, it was confirmed that d33 of the pseudo‐1‐3 piezoelectric ceramic/polymer composite increased with the increase of the electric filed strength applied at fabrication process, though, it reached a constant value at a certain strength value. Further it was confirmed that dielectric constant of the matrix had a small influence on d33 of the pseudo‐1‐3 piezoelectric ceramic/polymer composite, however, in case of matrix of lower Young's modulus, d33 was increase. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41817.
Miscibility behavior of epoxy thermosets loaded with an oligophosphonate
Authors: Carja Ionela‐Daniela , Serbezeanu Diana , Vlad‐Bubulac Tachita , Hamciuc Corneliu , Forrat Pérez Vicente , Romero Sánchez Maria Dolores , Guillem López Celia , Fuensanta Soriano Mónica
Published: December 2014

In this study, a commercial epoxy resin was mixed with a phosphorus‐containing oligomer and thermally cross‐linked using a mixture of two aliphatic amines as curing agents. The miscibility and the influence of the phosphorus‐containing oligomer on the characteristics of epoxy thermosets were investigated by scanning electron microscopy (SEM), thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. SEM revealed that phosphorus‐containing oligomer was well dispersed into the epoxy matrix. Dynamic mechanical analysis indicated an increase in storage modulus as the phosphorus‐containing oligomer content loaded into epoxy matrix increased. Thermogravimetric analysis showed that the onset temperature of phosphorus‐containing epoxy thermosets and the peak corresponding to the temperature of decomposition decreased compared with the ones corresponding to the neat epoxy system, whereas the char yield increased with the increase in phosphorus content added into the epoxy networks. To better understand the mechanism of action of phosphorus‐containing epoxy thermosets, the char residue was investigated by SEM and energy‐dispersive X‐ray spectroscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41822.
Impact of nanoclay on physicomechanical and thermal analysis of polyvinyl alcohol/fumed silica/clay nanocomposites
Authors: Lai Josephine Chang‐Hui , Rahman Md. Rezaur , Hamdan Sinin , Liew Fui Kiew , Rahman Md. Mizanur , Hossen Md. Faruk
Published: December 2014

Polyvinyl alcohol (PVA)/fumed silica/clay nanocomposites are prepared via solution intercalation by exploiting phase separation based on the bridging of particles by polymer chains. PVA/fumed silica/clay nanocomposites are characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and thermogravimetric analysis. Mechanical properties are determined by universal testing machine. From FTIR results, it indicates that IR spectrum for PVA/fumed silica/clay nanocomposites, especially PVA/fumed silica/clay (1.30E) nanocomposites, is much broader than pure PVA and other clay nanocomposites. The better interfacial bonding between PVA/fumed silica/clay (1.30E) nanocomposites are reflected in the improvement of the mechanical properties as well as thermal stability. The surface area analysis result proves that the PVA/fumed silica/clay (1.30E) nanocomposites have higher surface area and pore volume with less pore size. With the addition of 1.30E clay to the composite system, the tensile strength and modulus had shown the highest values as well as higher activation energy for thermal decomposition. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41843.
Viscoelastic properties of polyaniline–emeraldine base nanostructured films: Experimental results and molecular dynamics simulations
Authors: Bahramian Alireza
Published: December 2014

Comprehensive exploration of the viscoelastic properties of polyaniline–emeraldine base (PANI–EB) nanostructured films is presented from two viewpoints of experimental study associated with dynamic mechanical thermal analysis and thermogravimetric measurements and of computational simulations by molecular dynamics (MD) approach. The results are expressed in storage and loss modulus components (E′ andE″). The role of drying temperature, time, and residual solvent content were studied on theE′ andE″ of prepared PANI–EB films. Using the principle of time–temperature superposition,E′ andE″ at different temperatures and frequencies can be plotted on master curves. The relationship between the modulus components with the solvation level of PANI–EB film is also studied. MD simulation is applied to study the viscoelasticity of simulated PANI structures with different monomeric aniline chains. The temperature dependence of viscoelastic properties provides good information for fractional free volume, cavity size distribution, and activation energy of PANI structures. Simulation outcomes provide a fairly good compatibility with the experimental results. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 41858.
Solar forcing of Earth's surface temperature in PMIP3 simulations of the last millennium
Authors: Le Thanh
Published: December 2014

This study quantitatively diagnose the linkage between Total Solar Irradiance (TSI) and Earth's near‐surface air temperature (TAS) of past 1000‐year as simulated by Paleoclimate Modeling Intercomparison Project 3 (PMIP3) models. The results demonstrate that there is causal feedback of TAS from TSI variations, especially in the tropical and subtropical regions. The consistency between models in simulating solar signal in TAS responses is significant in these regions with more than 70% selected models showing agreement. There is no agreement between models in simulating TSI‐TAS relationship in mid and high latitude regions.
Genetic and nongenetic etiology of nonsyndromic anorectal malformations: A systematic review
Authors: Wijers Charlotte H. W. , van Rooij Iris A. L. M. , Marcelis Carlo L. M. , Brunner Han G. , de Blaauw Ivo , Roeleveld Nel
Published: December 2014

Congenital anorectal malformations (ARMs) are one of the most frequently observed birth defects of the digestive system. However, their etiology remains elusive. Therefore, we aim to summarize and critically appraise all existing literature on the genetic and nongenetic etiology of nonsyndromic ARM and to conclude with unifying hypotheses and directions for future research. A structured literature search on English language human studies was conducted in PubMed and Embase up to October 1, 2013, resulting in 112 included articles. Research on the identification of genes underlying nonsyndromic ARM is remarkably scarce. Most studies were focused on screening of candidate genes for mutations or single‐nucleotide polymorphisms, which did not yield any substantial evidence. Nongenetic factors fairly consistently found to be associated with ARM are assisted reproductive techniques, multiple pregnancy, preterm delivery, low birth weight, maternal overweight or obesity, and preexisting diabetes. This review provides indications for the involvement of both genes and nongenetic risk factors in the etiology of ARM. In future studies, large cohorts of patients with ARM from national and international collaborations are needed to acquire new hypotheses and knowledge through hypothesis‐generating approaches. Challenges for future studies may also lie in the investigation of gene–gene and gene–environment interactions. Birth Defects Research (Part C) 102:382–400, 2014. © 2014 Wiley Periodicals, Inc.
Biomimetic Oxidation with Fe‐ZSM‐5 and H2O2? Identification of an Active, Extra‐Framework Binuclear Core and an FeIIIOOH Intermediate with Resonance‐Enhanced Raman Spectroscopy
Authors: Hammond Ceri , Hermans Ive , Dimitratos Nikolaos
Published: December 2014

Developing inorganic materials that can mimic nature’s ability to selectively oxidise inert CH bonds remains a topic of intense scientific research. In recent years, zeolitic materials containing Fe and/or Cu have been shown to be highly active, heterogeneous catalysts for the selective oxidation of alkanes (including methane), amongst a range of other related oxidation challenges. By using resonance‐enhanced Raman spectroscopy, we demonstrate that, following high‐temperature pre‐treatment (activation), Fe‐containing ZSM‐5 possesses an active binuclear core, and forms a key FeOOH intermediate upon activation with H2O2. Both factors are reminiscent of biological oxidation catalysts, and may account for the unique ability of this material to selectively oxidise methane to methanol at low temperature.
Electrochemical Properties of Substituted 2‐Methyl‐1,4‐Naphthoquinones: Redox Behavior Predictions
Authors: Elhabiri Mourad , Sidorov Pavel , Cesar‐Rodo Elena , Marcou Gilles , Lanfranchi Don Antoine , Davioud‐Charvet Elisabeth , Horvath Dragos , Varnek Alexandre
Published: December 2014

In the context of the investigation of drug‐induced oxidative stress in parasitic cells, electrochemical properties of a focused library of polysubstituted menadione derivatives were studied by cyclic voltammetry. These values were used, together with compatible measurements from literature (quinones and related compounds), to build and evaluate a predictive structure–redox potential model (quantitative structure–property relationship, QSPR). Able to provide an online evaluation (through Web interface) of the oxidant character of quinones, the model is aimed to help chemists targeting their synthetic efforts towards analogues of desired redox properties
Cu‐Promoted Sydnone Cycloadditions of Alkynes: Scope and Mechanism Studies
Authors: Comas‐Barceló Júlia , Foster Robert S. , Fiser Béla , Gomez‐Bengoa Enrique , Harrity Joseph P. A.
Published: December 2014

Cu salts have been found to promote the cycloaddition reaction of sydnones and terminal alkynes, providing significant reduction in reaction times. Specifically, the use of Cu(OTf)2 is found to provide 1,3‐disubstituted pyrazoles, whereas simply switching the promoter system to Cu(OAc)2 allows the corresponding 1,4‐isomers to be produced. The mechanism of the Cu‐effect in each case has been investigated by experimental and theoretical studies, and they suggest that Cu(OTf)2 functions by Lewis acid activation of the sydnone, whereas Cu(OAc)2 promotes formation of reactive CuI acetylides.