bluuebunny/crossref_metadata_2025 huggingface dataset:
An electron microscopic analysis on the ultra structural abnormalities in sperm of the common carpCyprinus carpio L. inhabiting a polluted lake, Umiam (Meghalaya, India)
Authors: Massar Bashida , Dey Sudip , Dutta K.
Published: April 2011

The present communication reports the ultra structural abnormalities in sperm of a fish speciesCyprinus carpioinhabiting a polluted lake, Umiam in North‐East India. Transmission electron microscopy (TEM) revealed absence of differentiation between head and midpiece (neck) of some sperm while scanning electron microscopy (SEM) showed some sperm tails with highly reduced length and some sperm with folded tail. Abnormal shape of some sperm head was also revealed by Scanning electron microscopy. Detachment of membrane from some parts of the sperm head and an outward expansion of the same was observed from Transmission electron micrographs of transverse section of sperm head. The well developed mitochondria surrounding the cytoplasmic channel in the sperm tail, as observed in control were found to be drastically disorganized in fish inhabiting the polluted lake. The study suggests that the fishC. carpioinhabiting the polluted lake Umiam is under severe stress as far as its male reproductive system is concerned. The study further suggests that Electron microscopic approach is extremely important in the assessment of adverse effects of environmental pollution on fish tissue. Microsc. Res. Tech. 2011. © 2011 Wiley Periodicals, Inc.
Improved synthesis of dihydrothiophenes derivatives under ultrasound irradiation
Authors: Shi Da‐Qing , Zou Yi , Hu Yu , Wu Hui
Published: April 2011

A series of dihydrothiphenes derivatives were synthesized via the four‐component reaction of aldehyde, malononitrile, 1,3‐thiazolidinedione, and piperidine at room temperature under ultrasound irradiation. Compared with the conventional methods, the remarkable advantages of this method are operational simplicity, higher yield, and shorter reaction time. J. Heterocyclic Chem., (2011).
Reference values for atrial size and function in children and young adults by cardiac MR: A study of the german competence network congenital heart defects
Authors: Sarikouch Samir , Koerperich Hermann , Boethig Dietmar , Peters Brigitte , Lotz Joachim , Gutberlet Matthias , Beerbaum Philipp , Kuehne Titus
Published: April 2011

Purpose:

To provide reference data for atrial size and function during childhood and adolescence by cardiac MR (CMR).

Materials and Methods:

We prospectively examined 115 healthy children and adolescents (mean age, 12.4 ± 4.1 years; range, 4.4–20.3 years) by CMR using a stack of standard two‐dimensional steady‐state free‐precession slices acquisition covering the whole heart in transverse plane. Maximal and minimal volumes of both atria and their respective calculated cyclic volume change (CVC) and emptying fraction (EMF) were determined and reference centile curves were computed (lambda‐mu‐sigma [LMS]‐method).

Results:

Gender differences were noted for atrial volumes and derived parameters. Maximal right atrial (RA) volume for girls was 53.3 ± 11.8 mL/m2 and 58.1 ± 15.7 for boys (P = 0.064), minimal RA volume for girls/boys was 23.2 ± 6.2/27.0 ± 7.9 mL/m2 (P = 0.004). Maximal left atrial (LA) volume for girls/boys was 44.2 ± 8.7/46.7 ± 10.1 mL/m2 (P = 0.143) and minimal LA volume for girls/boys was 19.2 ± 3.9/21.5 ± 5.1 mL/m2 (P = 0.009). For both atria, CVC was higher for boys, but EMF higher for girls. Percentiles of RA/LA volumes showed steeper increase in boys than in girls, who in fact showed a plateau after age 14.

Conclusion:

Pediatric sex‐specific reference centiles are provided to improve clinical interpretation and facilitate future research involving CMR‐derived atrial function. J. Magn. Reson. Imaging 2011;33:1028–1039. © 2011 Wiley‐Liss, Inc.
Anomalous diffusion measured by a twice‐refocused spin echo pulse sequence: Analysis using fractional order calculus
Authors: Gao Qing , Srinivasan Girish , Magin Richard L. , Joe Zhou Xiaohong
Published: April 2011

Purpose:

To theoretically develop and experimentally validate a formulism based on a fractional order calculus (FC) diffusion model to characterize anomalous diffusion in brain tissues measured with a twice‐refocused spin‐echo (TRSE) pulse sequence.

Materials and Methods:

The FC diffusion model is the fractional order generalization of the Bloch‐Torrey equation. Using this model, an analytical expression was derived to describe the diffusion‐induced signal attenuation in a TRSE pulse sequence. To experimentally validate this expression, a set of diffusion‐weighted (DW) images was acquired at 3 Tesla from healthy human brains using a TRSE sequence with twelve b‐values ranging from 0 to 2600 s/mm2. For comparison, DW images were also acquired using a Stejskal‐Tanner diffusion gradient in a single‐shot spin‐echo echo planar sequence. For both datasets, a Levenberg‐Marquardt fitting algorithm was used to extract three parameters: diffusion coefficient D, fractional order derivative in space β, and a spatial parameter μ (in units of μm). Using adjusted R‐squared values and standard deviations, D, β, and μ values and the goodness‐of‐fit in three specific regions of interest (ROIs) in white matter, gray matter, and cerebrospinal fluid, respectively, were evaluated for each of the two datasets. In addition, spatially resolved parametric maps were assessed qualitatively.

Results:

The analytical expression for the TRSE sequence, derived from the FC diffusion model, accurately characterized the diffusion‐induced signal loss in brain tissues at high b‐values. In the selected ROIs, the goodness‐of‐fit and standard deviations for the TRSE dataset were comparable with the results obtained from the Stejskal‐Tanner dataset, demonstrating the robustness of the FC model across multiple data acquisition strategies. Qualitatively, the D, β, and μ maps from the TRSE dataset exhibited fewer artifacts, reflecting the improved immunity to eddy currents.

Conclusion:

The diffusion‐induced signal attenuation in a TRSE pulse sequence can be described by an FC diffusion model at high b‐values. This model performs equally well for data acquired from the human brain tissues with a TRSE pulse sequence or a conventional Stejskal‐Tanner sequence. J. Magn. Reson. Imaging 2011;33:1177–1183. © 2011 Wiley‐Liss, Inc.
Suppression of vascular enhancement artifacts through the use of a multiband, selectively spoiled radiofrequency excitation pulse
Authors: Ragan Dustin K. , Bankson James A.
Published: April 2011

Purpose:

To test the ability of a multi‐band RF pulse to reduce flow enhancement artifacts for steady state imaging without compromising temporal resolution or spatial coverage.

Materials and Methods:

Selectively spoiled composite RF pulses that provide simultaneous excitation and flow preparation were designed and tested by means of simulation, phantom, and in vivo measurements under varying conditions of flow.

Results:

Suppression of flow enhancement was found to depend on flow velocity and spatial extent of spoiled regions. By determining necessary pulse characteristics for a given experimental geometry, flow enhancement was reduced and sensitivity to T1‐reducing contrast agent was dramatically increased.

Conclusion:

These pulses provide an effective means of suppressing flow enhancement without sacrificing temporal resolution or spatial coverage. J. Magn. Reson. Imaging 2011;33:1256–1261. © 2011 Wiley‐Liss, Inc.
In vivo assessment of MR elastography‐derived effective end‐diastolic myocardial stiffness under different loading conditions
Authors: Kolipaka Arunark , McGee Kiaran P. , Manduca Armando , Anavekar Nandan , Ehman Richard L. , Araoz Philip A.
Published: April 2011

Purpose:

To compare magnetic resonance elastography (MRE) effective stiffness to end‐diastolic pressure at different loading conditions to demonstrate a relationship between myocardial MRE effective stiffness and end‐diastolic left ventricular (LV) pressure.

Materials and Methods:

MRE was performed on four pigs to measure the end‐diastolic effective stiffness under different loading conditions. End‐diastolic pressure was increased by infusing Dextran‐40 (20% of blood volume). For each infusion of Dextran‐40, end‐diastolic pressure was recorded and end‐diastolic effective stiffness was measured using MRE. In each pig, least‐square linear regression was performed to determine the correlation between end‐diastolic effective stiffness and end‐diastolic LV pressure.

Results:

A linear correlation was found between end‐diastolic LV pressure and end‐diastolic effective stiffness with R2 ranging from 0.73–0.9. A linear correlation with R2 = 0.26 was found between end‐diastolic LV pressure and end‐diastolic effective stiffness when pooling data points from all pigs.

Conclusion:

End‐diastolic effective myocardial stiffness increases linearly with end‐diastolic LV pressure. J. Magn. Reson. Imaging 2011;33:1224–1228. © 2011 Wiley‐Liss, Inc.
Hyperpolarized Xenon‐129 gas‐exchange imaging of lung microstructure: First case studies in subjects with obstructive lung disease
Authors: Dregely Isabel , Mugler John P. , Ruset Iulian C. , Altes Talissa A. , Mata Jaime F. , Miller G. Wilson , Ketel Jeffrey , Ketel Steve , Distelbrink Jan , Hersman F.W. , Ruppert Kai
Published: April 2011

Purpose:

To develop and test a method to noninvasively assess the functional lung microstructure.

Materials and Methods:

The Multiple exchange time Xenon polarization Transfer Contrast technique (MXTC) encodes xenon gas‐exchange contrast at multiple delay times permitting two lung‐function parameters to be derived: (i) MXTC‐F, the long exchange‐time depolarization value, which is proportional to the tissue to alveolar‐volume ratio and (ii) MXTC‐S, the square root of the xenon exchange‐time constant, which characterizes thickness and composition of alveolar septa. Three healthy volunteers, one asthmatic, and two chronic obstructive pulmonary disease (COPD) (GOLD stage I and II) subjects were imaged with MXTC MRI. In a subset of subjects, hyperpolarized xenon‐129 ADC MRI and CT imaging were also performed.

Results:

The MXTC‐S parameter was found to be elevated in subjects with lung disease (P‐value = 0.018). In the MXTC‐F parameter map it was feasible to identify regional loss of functional tissue in a COPD patient. MXTC‐F maps showed excellent regional correlation with CT and ADC (P ≥ 0.90) in one COPD subject.

Conclusion:

The functional tissue‐density parameter MXTC‐F showed regional agreement with other imaging techniques. The newly developed parameter MXTC‐S, which characterizes the functional thickness of alveolar septa, has potential as a novel biomarker for regional parenchymal inflammation or thickening. J. Magn. Reson. Imaging 2011;33:1052–1062. © 2011 Wiley‐Liss, Inc.
On the use of a spin‐echo based double inversion recovery acquisition for the measurement of cortical brain thickness
Authors: Nam Yoonho , Kim Eung Yeop , Kim Dong‐Hyun
Published: April 2011

Purpose:

To determine whether a spin‐echo‐based sequence, which are inherently insensitive to magnetic field inhomogeneity, can be used for brain cortical thickness measurement studies.

Materials and Methods:

By using a double inversion recovery (DIR) spin‐echo‐based sequence, cortical thickness estimates were performed from data acquired from seven healthy volunteers. The cortical thickness was also calculated from data acquired using an MPRAGE sequence and the Bland‐Altman analysis was performed for comparison of the two methods. The average signal and contrast to noise ratios (SNR, CNR) of the two methods were also calculated.

Results:

The bias over the entire brain between DIR and MPRAGE was 0.87 ± 0.08 mm. The bias calculated in the major regional lobes were temporal: 0.76 ± 0.09 mm, frontal: 0.89 ± 0.07 mm, parietal: 0.92 ± 0.10 mm, occipital: 0.75 ± 0.12 mm, and cingulate: 0.79 ± 0.10 mm. This thickness difference was due mainly to the boundary difference in the MPRAGE and DIR at the grey matter/cerebral spinal fluid (GM/CSF) regions. The mean SNR and CNR was CNRMPRAGE = 47.8 ± 8.4 and CNRDIR = 19.2 ± 2.9, SNRMPRAGE = 76.8 ± 10.5 and SNRDIR = 21.1 ± 2.8.

Conclusion:

The study suggests that cortical thickness measurements can be performed using a DIR spin‐echo sequence, which is inherently immune to main field inhomogeneity. Larger thickness measurements were consistently observed in DIR compared with MPRAGE. J. Magn. Reson. Imaging 2011;33:1218–1223. © 2011 Wiley‐Liss, Inc.
Measurement and comparison of T1 relaxation times in native and transplanted kidney cortex and medulla
Authors: Huang Yin , Sadowski Elizabeth A. , Artz Nathan S. , Seo Songwon , Djamali Arjang , Grist Thomas M. , Fain Sean B.
Published: April 2011

Purpose:

To measure and compare cortical and medullary T1 values in native and transplanted kidneys with a wide range of function as measured by estimated glomerular filtration rate (eGFR).

Materials and Methods:

A total of 27 subjects (12 native and 15 transplants) were studied. Two magnetic resonance imaging (MRI) exams of T1 measurement were performed on separate days for reproducibility study. Group‐wise comparisons of renal T1 on day 1 were performed between subjects with native and transplanted kidneys and also between subjects based on an eGFR threshold of 60 mL/min/1.73m2.

Results:

Transplanted kidneys had higher cortical renal T1 (1183 ± 136 msec) than native kidneys (1057 ± 94 msec) with similar results in the medulla. Subjects with an eGFR < 60 mL/min/1.73m2 had higher renal T1 than subjects with an eGFR > 60 mL/min/1.73m2 (cortical T1: P < 0.0001; medullary T1: P = 0.008). Renal T1 was highly reproducible for both native and transplant groups (with percent differences less than 10%).

Conclusion:

There are differences in cortical and medullary T1 between native and transplanted kidneys at different levels of function. J. Magn. Reson. Imaging 2011;33:1241–1247. © 2011 Wiley‐Liss, Inc.
Interest of diffusion‐weighted echo‐planar MR imaging and apparent diffusion coefficient mapping in gynecological malignancies: A review
Authors: Levy Antonin , Medjhoul Aïcha , Caramella Caroline , Zareski Elise , Berges Oscar , Chargari Cyrus , Boulet Bérénice , Bidault François , Dromain Clarisse , Balleyguier Corinne
Published: April 2011

Magnetic resonance imaging (MRI) remains the standard modality for the local staging of gynecological malignancies but it has several limitations, particularly for lymph node staging or evaluating peritoneal carcinomatosis. Consequently, there has been a growing interest in functional imaging modalities. Based on molecular diffusion, diffusion‐weighted imaging (DWI) is a unique, noninvasive modality that provides excellent tissue contrast and was shown to improve the radiological diagnosis of malignant tumors. Using quantitative apparent diffusion coefficient (ADC) measurement of DWI provides a new tool for better distinguishing malignant tissues from benign tumors. The aim of the present review is to report on the results of DWI for the assessment of patients with gynecological malignancies. An analysis of the literature suggests that DWI studies would improve the diagnosis of cervical and endometrial tumors. It may also improve the assessment of tumor extension in patients with peritoneal carcinomatosis from gynecological malignancies. However, since the signal intensity of some cancers can range from high intensity to low intensity, a degree of uncertainty was demonstrated due to the proximity of the normal uterine myometrium and ovaries. Interestingly, there is also evidence that ADC might improve the follow‐up and monitoring of patients who receive anticancer therapies, including chemotherapy or radiation therapy. J. Magn. Reson. Imaging 2011;33:1020–1027. © 2011 Wiley‐Liss, Inc.
Triceps brachii strength and regional body composition changes after detraining quantified by MRI
Authors: Popadic Gacesa Jelena Z. , Dusko Kozic B. , Grujic Nikola G.
Published: April 2011

Purpose:

To determine the triceps brachii functional adaptation and regional body composition changes after 12 months of detraining.

Materials and Methods:

Seventeen healthy young men (22.2 ± 1.0 y, body mass index 24.9 ± 3.1 kg/m2) were put in the detraining regimen for 12 months after completing a 12‐week exercise protocol on isoacceleration dynamometer (5 times a week, 5 daily series with 10 maximal elbow extensions, 1 min rest between sets). Triceps brachii muscle strength was measured by isoacceleration dynamometry, using identical protocol as during the training. Muscle volumes, subcutaneous adipose tissue (SCAT), and intermuscular adipose tissue (IMAT) at mid‐humerus were assessed by using MRI.

Results:

Long‐term detraining resulted in the significant decrease of 17% and 19% in endurance strength and fatigue rate, respectively. Maximal muscle strength slightly changed, and its 4% decrease was not significant. Triceps brachii volumes of both arms returned to their pretraining values (475.7 ± 54.91 cm3 for right arm, and 483.9 ± 77.5 cm3 for left arm). IMAT depots in upper arm significantly increased by 14% after 12 months of detraining, when compared with baseline values (P < 0.05).

Conclusion:

Long‐term detraining leads to triceps brachii adaptation with endurance strength decrease, volume return to its baseline values, and significant IMAT accumulation. IMAT values after 12 months of detraining exceed baseline, pretraining values, which is significant accumulation as a result of physiologically decreased muscle activity. J. Magn. Reson. Imaging 2011;33:1114–1120. © 2011 Wiley‐Liss, Inc.
Loss of fine structure and edge sharpness in fast‐spin‐echo carotid wall imaging: Measurements and comparison with multiple‐spin‐echo in normal and atherosclerotic subjects
Authors: Biasiolli Luca , Lindsay Alistair C. , Choudhury Robin P. , Robson Matthew D.
Published: April 2011

Purpose:

To test whether the k‐space acquisition strategy used by fast‐spin‐echo (FSE) is a major source of blurring in carotid wall and plaque imaging, and investigate an alternative acquisition approach.

Materials and Methods:

The effect of echo train length (ETL) and T2 on the amount of blurring was studied in FSE simulations of vessel images. Edge sharpness was measured in black‐blood T1 and proton‐density weighted (T1W and PDW) carotid images acquired from 5 normal volunteers and 19 asymptomatic patients using both FSE and multiple‐spin‐echo (Multi‐SE) sequences at 3 Tesla. Plaque images were classified and divided in group α (tissues' average T2 ∼40–70 ms) and group β (plaque components with shorter T2).

Results:

Simulations predicted 26.9% reduction of vessel edge sharpness from Multi‐SE to FSE images (ETL = 9, T2 = 60 ms). This agreed with in vivo measurements in normal volunteers (27.4%) and in patient group α (26.2%), while in group β the loss was higher (31.6%).

Conclusion:

FSE significantly reduced vessel edge sharpness along the phase‐encoding direction in T1W and PDW images. Blurring was stronger in the presence of plaque components with short T2 times. This study shows a limitation of FSE and the potential of Multi‐SE to improve the quality of carotid imaging. J. Magn. Reson. Imaging 2011;33:1136–1143. © 2011 Wiley‐Liss, Inc.
Effects of the bone morphogenetic protein binding protein spp24 (secreted phosphoprotein 24 kD) on the growth of human lung cancer cells
Authors: Lee Kwang‐Bok , Murray Samuel S. , Duarte M. Eugenia L. , Spitz Juliana F. , Johnson Jared S. , Song Kyung‐Jin , Brochmann Elsa J. , Taghavi Cyrus E. , Keorochana Gun , Liao Jen‐Chung , Wang Jeffrey C.
Published: April 2011

Bone morphogenetic proteins (BMPs) and transforming growth factor‐beta (TGF‐β) contribute to the growth of some skeletal metastases through autocrine stimulation. Secreted phosphoprotein 24 kDa (spp24) has been shown to bind to both BMP‐2 and TGF‐β and to markedly inhibit the osteogenic properties of rhBMP‐2. We hypothesized that the addition of spp24 would sequester autocrine growth factors (especially BMP‐2) and reduce tumor growth in a system (A549 human non‐small cell lung cancer cell line) where autocrine stimulation by BMP‐2 is known to be important. A549 cells were injected into two sites (subcutaneous and intraosseus) in SCID mice with and without the co‐injection of BMP‐2 and spp24. Tumor growth after 8 weeks was assessed through gross examination, radiological imaging, and histological analysis. Spp24 attenuated the tumor growth enhancing effects of rhBMP‐2 and reduced the tumor growth when added to tumor cells that were not treated with BMP‐2. We conclude that spp24 can reduce A549 cell tumor growth in both soft tissue and intraosseus environments. We hypothesize that the mechanism for this inhibition is interruption of autocrine stimulation through the sequestration of BMP‐2. Spp24 can be developed into a therapeutic agent that can be employed in clinical situations where the inhibitions of BMPs and related proteins is advantageous. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1712–1718, 2011
Characterization of a Technosol developed from deposited flue‐dust slurry and release of inorganic contaminants
Authors: Rennert Thilo , Kaufhold Stephan , Händel Matthias , Schuth Stephan , Meißner Sylvia , Totsche Kai U.
Published: April 2011

A flue dust originaly enriched in metal sulfides evolved as a by‐product of Cu smelting. The dust was deposited as slurry in unsealed heaps. It is characterized by very high contents of toxic metals such as Pb and Zn. The slurry is a source of soil, sediment, and water contamination. We studied a Technosol profile developed from deposited flue‐dust slurry by means of chemical and mineralogical characterization (SEM‐EDX, XRD, FTIR, DTA‐MS, XRF, Pb isotopes), by open‐flow and closed‐flow column experiments on contaminant release under water‐saturated conditions, and by geochemical modeling to evaluate release processes and to quantify aqueous contaminant concentrations. Besides ash particles and quartz, the flue‐dust slurry contains Fe oxides, silicates, sulfates, and sulfides (in varying states of weathering). In both column approaches, metal concentrations exceed inspection values. The concentration patterns in both experimental column approaches indicate near‐equilibrium mineral dissolution. Geochemical modeling reveals partial dissolution of sulfates and precipitation of secondary carbonates. Their precipitation prevents complete sulfate dissolution, which would have led to even higher aqueous metal concentrations and contaminant export. The combination of detailed material characterization, column experiments, and modeling allows for quantitative and qualitative estimation of contaminant release into the soil solution.
Development and validation of an HPLC method for the simultaneous determination of tocopherols, tocotrienols and carotenoids in cereals after solid‐phase extraction
Authors: Irakli Maria N. , Samanidou Victoria F. , Papadoyannis Ioannis N.
Published: April 2011

The increasing interest in antioxidant properties of cereal and cereal‐based products has prompted the development of a simple and reliable HPLC method for the simultaneous determination of important phytochemicals like tocopherols (T), tocotrienols (T3) and carotenoids. Separation was carried out on a Nucleosil 100 C18 column, 5 μm (250 mm×4.6 mm) thermostated at 25°C, using a linear gradient elution system starting with methanol and ending with a mixture of methanol–isopropanol–acetonitrile. All separated compounds including the internal standard (α‐tocopherol acetate) were eluted within 16 min and detected by dual detection: fluorescence for tocopherols and tocotrienols at 290 nm excitation and 320 nm emission and UV–vis photodiode array detection for lutein and β‐carotene at 450 nm. Detection limits ranged from 0.2 μg/g (β‐carotene) to 1.60 μg/g (α‐tocopherol). The intra‐ and inter‐assay coefficients of variation were calculated by using cereals with different levels of lipophilic antioxidants. The extraction method involved sample saponification and clean‐up by solid‐phase extraction (SPE). The extraction recoveries obtained using OASIS HLB SPE cartridges and dichloromethane as eluent were in the range of 90.2–110.1%, with RSD lower than 10%. The method was successfully applied to cereals: durum wheat, bread wheat, rice, barley, oat, rye, corn and triticale.
Quantitation of free and total bisphenol A in human urine using liquid chromatography‐tandem mass spectrometry
Authors: Fox Stephen D. , Falk Roni T. , Veenstra Timothy D. , Issaq Haleem J.
Published: April 2011

Bisphenol A (BPA) is employed in the synthesis of polycarbonate plastics and epoxy resins and is widely used in consumer products including as a coating for the inside of almost all food and beverage containers and thermal‐imaging paper. Bisphenol A is considered to have important health implications because it possesses weak estrogenic activity and can leach from storage containers resulting in its consumption by both humans and animals. It is metabolized in the body and excreted into urine as a glucuronide derivative. In this report, we present an accurate, selective, sensitive, and reproducible high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) method for the quantitation of BPA in human urine, which is not prone to exogenous contamination. BPA‐glucuronide is hydrolyzed enzymatically, extracted with toluene, derivatized with dansyl chloride, and the BPA‐(dansyl)2 derivative is analyzed using reversed‐phase HPLC/MS/MS. Calibration was linear to 50 ng/mL with a limit of quantitation of 50 pg/mL and a limit of detection of 5 pg/mL.
Thermoresponsiveness of Integrated Ultra‐Thin Silicon with Poly(N‐isopropylacrylamide) Hydrogels
Authors: Yu Cunjiang , Pan Yuping , Ma Huan , Ma Teng , Zhang Jiaping , Song Yanmei , Kalani M. Yashar S. , Dai Lenore , Jiang Hanqing
Published: April 2011

Stimuli‐sensitive polymer materials have limited device functionality, design and manufacturing flexibility although they are pushed to enable smart device applications. Here we demonstrate the capability of integrating thermoresponsive poly(N‐isopropylacrylamide) (PNIPAAm) hydrogels with silicon nanoribbons, and enable the stiff silicon ribbons to become adaptive and drivable by the soft environmentally sensitive substrate, such as becoming mechanically stretched and compressed on temperature change. These and related soft/hard smart devices and systems may open new opportunities in biomedical applications.

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Polymer Brushes by the “Grafting to” Method
Authors: Zdyrko Bogdan , Luzinov Igor
Published: April 2011

This paper focuses on the attachment of densely grafted polymer layers (polymer brushes) to various inorganic and polymeric substrates by the “grafting to” method. A brief overview of synthesis of polymer brushes by the method is first provided, with emphasis on chemical approaches to polymer attachment. The second part of the paper covers the synthesis of polymer layers via a recently developed macromolecular anchoring layer approach. Several examples of application of the grafting technique are presented for generation of hydrophobic, hydrophilic, gradient, and switchable surfaces.

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Modulation of dysarthropneumophonia by low‐frequency STN DBS in advanced Parkinson's disease
Authors: Moreau Caroline , Pennel‐Ployart Odile , Pinto Serge , Plachez Audrey , Annic Agnes , Viallet François , Destée Alain , Defebvre Luc
Published: April 2011

Background:

Parkinsonian dysarthria (as typically characterized by hypophonia, monotony of pitch, and rhythm abnormalities) is often accompanied by gait disturbances. The long‐term effect of subthalamic nucleus deep brain stimulation (STN DBS) on dysarthria remains unclear.

Methods:

Given STN DBS's known improvement of gait disorders, we analyzed speech intelligibility and aerodynamic and acoustic parameters in 11 advanced PD patients in three double‐blind, randomized conditions: “defined Off,” 60 Hz STN DBS and 130 Hz STN DBS.

Results:

An improvement in aerodynamic speech parameters during 60 Hz STN DBS was accompanied by significant clinical benefit.

Conclusions:

Chronic treatment with low‐frequency STN DBS may have a beneficial impact on dysarthropneumophonia, even in advanced PD patients. © 2011 Movement Disorder Society
Wine drinking and essential tremor: A possible protective role
Authors: Nicoletti Alessandra , Mostile Giovanni , Cappellani Roberto , Contrafatto Donatella , Arabia Gennarina , Lamberti Paolo , Marconi Roberto , Morgante Letterio , Barone Paolo , Quattrone Aldo , Zappia Mario
Published: April 2011

The purpose of this study was to evaluate the possible association of cigarette smoking, coffee drinking, and wine consumption with essential tremor using a matched case–control design. Cases and controls were enrolled from 6 Movement Disorder centers in central‐southern Italy. Essential tremor was diagnosed according to Bain's criteria. Three unrelated healthy controls (not affected by neurological disorders) per each enrolled case, matched by sex and age (±5 years), were selected. A standardized questionnaire was administered to record demographic, epidemiological, and clinical data. All cases and controls underwent a standard neurological examination. Adjusted odds ratios and 95% confidence intervals were estimated using conditional logistic regression for the matched cases and controls. Eighty‐three patients with essential tremor (38 men and 45 women; mean age, 68.2 ± 8.6 years) and 245 matched control subjects (113 men and 132 women; mean age, 68.4 ± 9.7 years) were enrolled in the study. Multivariate analysis showed a significant negative association between essential tremor and wine consumption preceding the onset of disease (adjusted odds ratio, 0.23; 95% confidence interval, 0.08–0.64; P = .0005) with a significant dose effect (1–2 glass of wine per day: odds ratio, 0.32; 95% confidence interval, 0.10–0.95; P = .04; more than 3 glass of wine per day: odds ratio, 0.14; 95% confidence interval, 0.03–0.62; P = .01). In our sample no association between essential tremor and cigarette smoking or coffee drinking was found. Our data suggest a negative association between wine drinking and essential tremor, which could be explained by the long‐term neuroprotective effect of its antioxidant components. © 2011 Movement Disorder Society
Experimental and theoretical NMR and IR studies of the side‐chain orientation effects on the backbone conformation of dehydrophenylalanine residue
Authors: Buczek Aneta M. , Ptak Tomasz , Kupka Teobald , Broda Małgorzata A.
Published: April 2011

Conformation of N‐acetyl‐(E)‐dehydrophenylalanine N′, N′‐dimethylamide (Ac‐(E)‐ΔPhe‐NMe2) in solution, a member of (E)‐α, β‐dehydroamino acids, was studied by NMR and infrared spectroscopy and the results were compared with those obtained for (Z) isomer. To support the spectroscopic interpretation, the ϕ, ψ potential energy surfaces were calculated at the MP2/6‐31 + G(d,p) level of theory in chloroform solution modeled by the self‐consistent reaction field‐polarizable continuum model method. All minima were fully optimized by the MP2 method and their relative stabilities were analyzed in terms of π‐conjugation, internal H‐bonds and dipole interactions between carbonyl groups. The obtained NMR spectral features were compared with theoretical nuclear magnetic shieldings, calculated using Gauge Independent Atomic Orbitals (GIAO) approach and rescaled to theoretical chemical shifts using benzene as reference. The calculated indirect nuclear spin‐spin coupling constants were compared with available experimental parameters. Copyright © 2011 John Wiley & Sons, Ltd.
Whether, when, and who to disclose bad news to patients with cancer: a survey in 150 pairs of hospitalized patients with cancer and family members in China
Authors: Li Juan , Yuan* Xiang Lin , Gao Xian Hua , Yang Xiao Mei , Jing Peng , Yu Shi Ying
Published: April 2011

Objective

The purpose of this study is to determine how to disclose bad news to patients with cancer in China.

Methods

One hundred fifty pairs of hospitalized patients and their family members were investigated using a self‐designed questionnaire.

Results

More patients than their families believed that patients should be informed of their illnesses (98.0% vs 66.7%, p < 0.001), that patients should be informed of their condition completely (69.3% vs 18.7%, p < 0.001), that patients should be informed as soon as the diagnoses were confirmed (49.3% vs 14.7%, p < 0.001), and that patients should be informed by doctors (55.3% vs 10.7%, p < 0.001). κ coefficients between patients and their families on “whether, when and who to disclose” ranged from −0.084 to 0.004. Univariate logistic analyses demonstrated that farmer patients and patients with lower education and lower income were less likely to prefer to be informed completely; farmer patients and patients without an intended curative operation history were less likely to prefer to be informed immediately and directly by doctors. Multivariate analyses showed that farmer patients were less likely to prefer to be informed completely, immediately, and directly by doctors.

Conclusions

There was poor or slight concordance in disclosure preferences between patients with cancer and their families. More patients than their families wanted to be informed completely, immediately, and directly by doctors. Farmer patients with cancer were less likely to prefer to be informed completely, immediately, and directly by doctors. Copyright © 2011 John Wiley & Sons, Ltd.
An inferential procedure for the probability of passing the USP dissolution test
Authors: Chiang Chieh , Chen Chen‐Fang , Huang Meng‐Yang , Liu Jen‐Pei
Published: April 2011

Dissolution is one of the tests that is required and specified by the United States Pharmacopeia and National Formulary (USP/NF) to ensure that the drug products meet the standards of the identity, strength, quality, purity, and stability. The sponsors also establish the in‐house specifications for the mean and standard deviation of the dissolution rates to guarantee a high probability of passing the USP/NF dissolution test. However, the USP/NF dissolution test is a complicated three‐stage sampling plan that involves both the sample mean dissolution rate of all units and the dissolution rate of individual units. It turns out that the true probability of passing the USP/NF dissolution is formidable to compute analytically even when the population mean and variance of dissolution rates are known. It is not clear that previously proposed methods are the estimators of the true probability for passing the USP dissolution test. Therefore, we propose to employ a parametric bootstrap method in conjunction with the Monte Carlo simulation to obtain the sampling distribution of the estimated probabilities of passing the USP/NF dissolution test and hence the confidence interval for the passing probability. In addition, a procedure is proposed to test whether the true probability of passing the USP/NF dissolution test is greater than some specified value. A numerical example illustrates the proposed method. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of Amphiphilic Polythiophene for Cell Imaging and Monitoring the Cellular Distribution of a Cisplatin Anticancer Drug
Authors: Tang Hongwei , Xing Chengfen , Liu Libing , Yang Qiong , Wang Shu
Published: April 2011

A new amphiphilic conjugated polythiophene derivative (PT–Boc) is synthesized via Suzuki coupling reaction. The amphiphilic characteristic makes it form nanoaggregates in water, in which hydrophobic moieties come together to form the inner core. The polymer shows good photostability and no toxicity to human lung epithelial (A549) cells even at a high concentration (100 μg mL−1). It therefore meets the crucial requirement for cellular imaging and other biological applications. The anticancer drug cisplatin is used as a model, and is linked to polythiophene to obtain a conjugate ‘PT–Pt’ by coordinated interactions between cisplatin and the amine groups of the polythiophene side chain. The PT–Pt can be used for monitoring the cellular distribution of cisplatin by fluorescence microscopy. The amphiphilic polythiophene provides a platform for fluorescent imaging of drugs and biological molecules in living cells.
Probing the Collapse Dynamics of Poly(N‐isopropylacrylamide) Brushes by AFM: Effects of Co‐nonsolvency and Grafting Densities
Authors: Sui Xiaofeng , Chen Qi , Hempenius Mark A. , Vancso G. Julius
Published: April 2011

Collapse of poly(N‐isopropylacrylamide) (PNIPAM) brushes in the mixed solvent system (water/methanol 50% v/v) is studied by in‐situ atomic‐force microscopy (AFM). PNIPAM brushes with three different grafting densities and similar chain lengths are synthesized via surface‐initiated atom‐transfer radical polymerization. By changing the solvent from water to a water/methanol (50% v/v) mixture, the polymer brushes switch from a swollen to collapsed state. AFM force measurements using a silica colloidal probe attached to the tip are employed to obtain the Young’s moduli of the polymer brushes in different solvation states. The collapse dynamics of the brush is followed by monitoring the pull‐off force (adherence) in situ. The modulus of the swollen high‐density polymer brush is four times lower than that of the same brush in the collapsed state. It is shown that in the case of the high‐density polymer brush with a thickness (tin water) of 900 nm, the collapse takes place in a time scale of ~25 s, whereas the collapse occurs faster for the medium‐density brush (tin water = 630 nm) and much more rapidly for the low‐density brush (tin water = 80 nm). This difference in the response kinetics is primarily ascribed to the time needed for solvent exchange in the polymer brushes.
Vaults Engineered for Hydrophobic Drug Delivery
Authors: Buehler Daniel C. , Toso Daniel B. , Kickhoefer Valerie A. , Zhou Z. Hong , Rome Leonard H.
Published: April 2011

The vault nanoparticle is one of the largest known ribonucleoprotein complexes in the sub‐100 nm range. Highly conserved and almost ubiquitously expressed in eukaryotes, vaults form a large nanocapsule with a barrel‐shaped morphology surrounding a large hollow interior. These properties make vaults an ideal candidate for development into a drug delivery vehicle. In this study, the first example of using vaults towards this goal is reported. Recombinant vaults are engineered to encapsulate the highly insoluble and toxic hydrophobic compound all‐trans retinoic acid (ATRA) using a vault‐binding lipoprotein complex that forms a lipid bilayer nanodisk. These recombinant vaults offer protection to the encapsulated ATRA from external elements. Furthermore, a cryo‐electron tomography (cryo‐ET) reconstruction shows the vault‐binding lipoprotein complex sequestered within the vault lumen. Finally, these ATRA‐loaded vaults show enhanced cytotoxicity against the hepatocellular carcinoma cell line HepG2. The ability to package therapeutic compounds into the vault is an important achievement toward their development into a viable and versatile platform for drug delivery.
D‐cycloserine facilitates extinction of cocaine self‐administration in c57 mice
Authors: Thanos Panayotis K. , Subrize Mike , Lui Wendy , Puca Zachary , Ananth Mala , Michaelides Michael , Wang Gene‐Jack , Volkow Nora D.
Published: April 2011

Introduction: Cocaine is a highly addictive drug of abuse for which there are currently no medications. In rats and mice d‐cycloserine (DCS), a partial NMDA agonist, accelerates extinction of cocaine seeking behavior. Since cues delay extinction here, we evaluated the effects d‐cycloserine in extinction with and without the presence of cues. Methods: Two doses of DCS (15 and 30 mg/kg) were studied in C57 mice. Mice self‐administered cocaine (1 mg/kg) for 2 weeks and then underwent a 20‐day extinction period where DCS was administered i.p. immediately following each daily session. Extinction was conducted in some mice with the presence of cocaine‐paired cues; while others were in the absence of these cues. Results: DCS treated mice (either dose) showed significantly reduced lever pressing during extinction with cue exposures when compared with vehicle treated mice. Without cues, animals showed much lower levels of lever pressing but the differences between vehicle and DCS were not significant. Conclusion: DCS accelerated extinction with the presence of cues, but there were no differences on extinction without cues as compared with vehicle. These findings are consistent with DCS disrupting the memory process associated with the cues. Since drug cues are significantly involved in relapse, these findings support research to assess the therapeutic potential of DCS in cocaine addiction. Synapse 2011. © 2011 Wiley‐Liss, Inc.
Bit error rate performance of orthogonal frequency‐division multiplexing relaying systems with high power amplifiers and Doppler effects
Authors: Ahmed Hassan A. , Sulyman Ahmed Iyanda , Hassanein Hossam S.
Published: April 2011

This paper analyzes the bit error rate performance of orthogonal frequency‐division multiplexing systems in mobile multihop relaying channels. We considered the uplink scenario and quantified the effects of mobile channel impairments such as Doppler shift due to user mobility per hop, high power amplifier distortions when amplifying the transmitted/relayed orthogonal frequency‐division multiplexing symbol per hop, and the cumulative effects of these impairments on multihop relaying channels. It was shown that the resulting intercarrier interference due to the cumulative effects of the phase noise generated by these impairments per hop becomes very significant in a multihop relaying communication system and severely degrades the bit error rate performance of the system. Simulation results agree well with and validate the analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Crustal Accretion and Metamorphism of Mesoarchean Granulites in Palghat-Cauvery Shear Zone, Southern India
Authors: Choudhary A.K. , Jain A.K. , Singh Sandeep , Manickavasagam Rm. , Chandra K.
Published: April 2011

This work provides unequivocal evidence of the existence of Mesoarchean granulite facies metamorphic event in the Palghat-Cauvery Shear Zone (PCSZ) of South India. Charnockite samples from two prominent hills at Kollaimalai (KM) and Pachchaimalai (PM) as well as from two quarries within the Bhavani Shear Zone (BSZ) have been analyzed for their Sm-Nd and Rb-Sr ages to investigate the existence or otherwise of the Archean granulite facies events within the PCSZ. The Rb-Sr whole-rock isochron ages for massive charnockites from both the hills appear to be contemporaneous at 2.9 Ga with the initial Sr isotopic ratios of 0.7012 and 0.7014, respectively. However, the Rb-Sr data for whole-rock samples of basic granulites from one of the quarries within the BSZ indicate open system behavior, while the charnockites from the other quarry have insufficient spread in 87Rb/86Sr ratios and do not yield any isochron. The Sm-Nd data, on the other hand, do not distinguish between the massive charnockite and the lowland charnockite and yield Depleted Mantle model ages in the range 2.98±0.3 Ga for all of them. The εT CHUR for all of these rocks are highly positive. Both the Sr isotopic ratios and positive εT CHUR values for these rocks strongly suggest a mantle source for all of them. An upper age limit of ~3.28 Ga may be assigned to the crustal accretion of the protolith of all these rocks on the basis of their Nd model ages. The Rb-Sr isochron ages of 2.9 Ga for the two massifs could be the age of granulite facies metamorphism. Thus, the metamorphism in the KM and PM Hills took place within ~100 Ma of crustal accretion of these rocks and probably was part of the same geological event of crust formation and metamorphism. The open system behavior with respect to Rb-Sr isotopes in the basic granulite from Bhavani is possibly due to the migration of Sr isotopes, triggered during the later shearing of these rocks.
Radiocarbon Evidence of Paleo-recharge (pre-Saraswati period) of Potential Deep Aquifer in Thar Desert
Authors: Reddy D. V. , Nagabhushanam P. , Rao M. R. , Mitra D. S. , Tripati B. M. , Sinha S. K. , Bhadu B.
Published: April 2011

The Oil and Natural Gas Corporation Limited (ONGC), India, embarked upon exploration and exploitation of deep groundwater under the project named as “Saraswati” in arid Thar desert, Rajasthan, with a societal mission of providing water to the local people and cattle. A 555 m deep well drilled by the ONGC near Jaisalmer town in 2006 encountered a potential aquifer at a depth of 450-500 m. Radiocarbon dating of this well water indicated paleo-recharge to be >40,000 yr BP (uncorrected) (Before Present with respect to 1950 AD), while the medium depth (~200 m) well waters around that area showed an age range of ~9,000 to 17,000 yr BP (uncorrected). These waters represent pre-Saraswati era recharge, because the mighty Saraswati flowed in this region between 7000 – 4000 yr BP. The stable isotope (δD and δ18O) and Total Dissolved Solids (TDS) data of these waters clearly indicated absence of communication between the two aquifers (deep and medium depth). However, the extension of this deep aquifer needs to be determined.
The Mw 7.5 2009 Coco Earthquake, North Andaman Region
Authors: Mahesh P. , Bansal Amit , Kundu B. , Catherine J. K. , Gahalaut V. K.
Published: April 2011

The recent 10 August 2009 Coco earthquake (Mw 7.5), the largest aftershock of the giant 2004 Sumatra Andaman earthquake, occurred within the subducting India plate under the Burma plate. The Coco earthquake nucleated near the northwestern edge of the 2004 Sumatra-Andaman earthquake rupture under the unruptured updip segment of the plate boundary interface. The earthquake with predominant normal motion on approximately north-south to northeast-southwest oriented plane is very similar to the 27 June 2008 Little Andaman earthquake which occurred in the South Andaman region near the trench. We provide the only available estimate of coseismic offset due to the 2009 Coco earthquake at a survey-mode GPS site in the north Andaman, located about 60 km south of the Coco earthquake epicentre. The not so large coseismic displacement of about 2 cm in the ESE direction is consistent with the earthquake focal mechanism and its magnitude. We suggest that, like the 2008 Little Andaman earthquake, this earthquake too occurred on one of the approximately north-south to northeast-southwest oriented steep planes of the obliquely subducting 90°E ridge which was reactivated in normal motion after subduction, under the favourable influence of coseismic and ongoing postseismic deformation due to the 2004 Sumatra-Andaman earthquake. Another notable feature of this earthquake is its relatively low aftershock productivity. We suggest that the earthquake occurred very close to the aseismic region of the Irrawaddy frontal arc of very low seismicity where pre-existing faults are not so critically stressed and because of which the earthquake could trigger only a few aftershocks in its immediate vicinity.
Engineering Geological Rock Mass Classification of Punasa Tunnel Site, Khandwa District, Madhya Pradesh
Authors: Gupta M. C. , Singh B. K. , Singh K. N.
Published: April 2011

Systematic rock mass characterization is an integral part of rock engineering practices. In the present scenario several classifications are in used for rock mass characterization for tunnelling. The present paper discusses engineering geological investigations carried out for Punasa tunnel, a part of Narmada Sagar project. The horse shoe shaped tunnel is 3675.25 m long and 9 m in diameter. This straight and free flow tunnel has been constructed in basaltic lava flows erupted during Cretaceous to Eocene age, belonging to poor to fair rock mass rating (RMR) and extremely poor to good in tunnel quality (Q-system). The values of RMR and Q-system ranges from 29 to 74 and 0.0825 to 13.33 respectively.
Cultural influences on preference consistency: Consistency at the individual and collective levels
Authors: Wilken Brooke , Miyamoto Yuri , Uchida Yukiko
Published: April 2011

Research highlights

► Across three studies, cultural differences in preference consistency were found. ► Further, differences at the individual level aggregated into collective differences. ► Moreover, findings generalized from self‐reported to actual preference consistency.