bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Tri‐ or Tetrasubstituted Pyrimidine Derivatives through the [5+1] Annulation of Enamidines with either N,N‐Dimethylformamide Dialkyl Acetals or Orthoesters and Their Application in a Ring Transformation of Pyrimidines to Pyrido[2,3‐d]pyrimidin‐5‐one Derivatives
Authors: Sasada Toshiaki , Aoki Youichi , Ikeda Reiko , Sakai Norio , Konakahara Takeo 
Published: July 2011

AbstractThe [5+1] annulation of enamidines, which were prepared from functionalized silanes, organolithium compounds and two nitriles, with N,N‐dimethylformamide dialkyl acetals as the C1 unit is described, leading to the synthesis of tri‐ and tetrasubstituted pyrimidine derivatives under catalyst‐ and solvent‐free reaction conditions. Furthermore, the [5+1] annulation of enamidines by using orthoesters as the C1 unit is described, in which catalytic amounts of ZnBr2 catalyze the annulation to produce polysubstituted pyrimidines under toluene or xylene reflux conditions. Moreover, the combination of a reductive ring‐opening reaction with [Mo(CO)6] and a subsequent intramolecular cyclization with tBuOK effectively causes a skeletal transformation from the pyrimidines containing an isoxazolyl and an ethoxy substituent to form pyrido[2,3‐d]pyrimidin‐5‐one frameworks in excellent yield.
Synthesis and Modification of Silicon Nanosheets and Other Silicon Nanomaterials
Authors: Okamoto Hirotaka , Sugiyama Yusuke , Nakano Hideyuki 
Published: July 2011

AbstractSilicon nanomaterials and nanostructures exhibit different properties from those of bulk silicon materials based on quantum confinement effects. They are expected to lead to the development of new applications of silicon, in addition to wide use in semiconductor devices. Aside from industrial interest, intriguing issues of academic interest still remain with respect to the origins of their characteristic properties. Zero‐ and one‐dimensional crystalline silicon nanomaterials have been synthesized, to date, by using many methods and there has been rapid progress in size control and modification procedures. However, there have been only a few examples of silicon nanomaterials with atomic‐order thickness akin to carbon nanomaterials, such as two‐dimensional silicon nanosheets. Moreover, mass production of silicon nanomaterials with relatively low cost is not easily achievable, due to the typically severe conditions required for fabrication, such as high temperature and ultralow pressure. Recently, we have developed a soft synthetic method for silicon nanosheets with chemical surface modification in a solution process. This review provides methods for the synthesis and modification of silicon nanosheets and other silicon nanomaterials with examples of their potential applications.
Usefulness of Tissue Doppler Imaging‐Myocardial Performance Index in the Evaluation of Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction
Authors: Kim Hyungseop , Yoon Hyuck‐Jun , Park Hyoung‐Seob , Cho Yun‐Kyeong , Nam Chang‐Wook , Hur Seung‐Ho , Kim Yoon‐Nyun , Kim Kwon‐Bae 
Published: July 2011

AbstractBackground:In heart failure with preserved ejection fraction (HFPEF), physiological abnormalities are not solely restricted to diastolic function. Because the tissue Doppler imaging (TDI)‐derived myocardial performance index (MPI) offers the advantage of recording systolic and diastolic tissue velocity simultaneously in the same cardiac cycle, this study aimed to determine whether TDI‐MPI is an informative index for assessing HFPEF, compared with conventional echo parameters.Hypothesis:In patients with HFPEF, TDI‐MPI would be an independent predictor for adverse cardiac events.Methods:Among 408 patients who had diastolic dysfunction without heart failure (HF) or HFPEF, cardiac function was evaluated by mitral flow (MF) or TDI‐MPI. During the median follow‐up of 32 months, clinical outcomes, which were defined as the composite of cardiovascular death and admission for HF, were assessed.Results:Mean MF and TDI‐MPI were significantly greater in the HFPEF group. TDI‐MPI rather than MF had a significant correlation with N‐terminal pro‐brain natriuretic peptide level. The area under the receiver operating characteristic curve of TDI‐MPI for the detection of HFPEF was 0.86. With regard to clinical outcomes, 31 events were identified during follow‐up periods. On a multivariate analysis, TDI‐MPI >0.66 was the best prognostic predictor of events and provided incremental predictive value.Conclusions:Compared to MF‐MPI, TDI‐MPI may be a more useful parameter for the evaluation of patients with HFPEF. © 2011 Wiley Periodicals, Inc.The authors have no funding, financial relationships, or conflicts of interest to disclose.
Ultrastructural analysis of spermiogenesis in Rhacophorus arboreus (Amphibia, Anura, Rhacophoridae)
Authors: Muto Kohei , Kubota Hiroshi Y. 
Published: July 2011

AbstractThe spermatozoa of the Japanese green tree frog, Rhacophorus arboreus (Amphibia, Anura, Rhacophoridae), have a characteristic corkscrew‐shaped head and a thick tail that extends perpendicular to the longitudinal axis of the head. We examined the process of spermatogenesis in Rh. arboreus, particularly spermiogenesis, using light and transmission electron microscopy. Spermiogenesis was categorized into the early, mid, and late stages based on the spermatid morphology and their location within the cyst. Early spermatids had a round nucleus and two independent flagella that elongated from a pair of parallel centrioles. The centrioles became embedded in centriolar adjunct material and attached to the nucleus. Then, the flagella were covered with a mantle‐like cytoplasm that contained many microtubules. An acrosome appeared on the pointed side of the slightly elongated nucleus. Mid spermatids had an elongated rod‐like head. As the nucleus elongated, the chromatin fibers became thicker and were arranged parallel to the elongation axis. An elongated acrosome was attached helically along the lateral side of the elongated nucleus. The biflagellate spermatids transformed into monoflagellate spermatids with two axonemes through a process in which the plasma membrane of each flagellum expanded. Late spermatids had a coiled or corkscrew‐shaped head. An acrosome was located on the inside of the coiled cone composed of a nucleus. Parallel microtubules were connected in rows, and then became crystallized in the tail. The present report contains the first morphological description of spermatogenesis in Rhacophorus and suggests that spermiogenesis evolved to adapt to the fertilization environment. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
MRI‐guided ablation of breast cancer: Where do we stand today?
Authors: Postma Emily L. , van Hillegersberg Richard , Daniel Bruce L. , Merckel Laura G. , Verkooijen Helena M. , van den Bosch Maurice A.A.J. 
Published: July 2011

AbstractThe treatment of patients with localized breast cancer has changed considerably over the past few decades. The next challenge is to use image‐guided minimally invasive tumor ablation techniques. The fact that MRI is the most accurate imaging modality for visualization and delineation of breast tumor margins in three dimensions and provides MRI‐based temperature mapping, makes it particularly applicable for monitoring during minimally invasive ablation techniques. The overall result of the studies performed on MRI‐guided minimally invasive tumor ablation studies are varying, with reported total tumor ablation rates ranging between 20% and 100%. Strict selection of patients, consensus on the treatment zone margin and optimization of MR‐imaging, should make MRI‐guided breast cancer tumor ablation a useful tool in clinical practice. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
MR properties of brown and white adipose tissues
Authors: Hamilton Gavin , Smith Daniel L. , Bydder Mark , Nayak Krishna S. , Hu Houchun H. 
Published: July 2011

AbstractPurpose:To explore the MR signatures of brown adipose tissue (BAT) compared with white adipose tissue (WAT) using single‐voxel MR spectroscopy.Materials and Methods:1H MR STEAM spectra were acquired from a 3 Tesla clinical whole body scanner from seven excised murine adipose tissue samples of BAT (n = 4) and WAT (n = 3). Spectra were acquired at multiple echo times (TEs) and inversion times (TIs) to measure the T1, T2, and T2‐corrected peak areas. A theoretical triglyceride model characterized the fat in terms of number of double bonds (ndb) and number of methylene‐interrupted double bonds (nmidb).Results:Negligible differences between WAT and BAT were seen in the T1 and T2 of fat and the T2 of water. However, the water fraction in BAT was higher (48.5%) compared with WAT (7.1%) and the T1 of water was lower in BAT (618 ms) compared with WAT (1053 ms). The fat spectrum also differed, indicating lower levels of unsaturated triglycerides in BAT (ndb = 2.7, nmidb = 0.7) compared with WAT (ndb = 3.3, nmidb = 1.0).Conclusion:We have demonstrated that there are several key MR‐based signatures of BAT and WAT that may allow differentiation on MR imaging. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Fully automatic geometry planning for cardiac MR imaging and reproducibility of functional cardiac parameters
Authors: Frick Michael , Paetsch Ingo , den Harder Chiel , Kouwenhoven Marc , Heese Harald , Dries Sebastian , Schnackenburg Bernhard , de Kok Wendy , Gebker Rolf , Fleck Eckart , Manka Robert , Jahnke Cosima 
Published: July 2011

AbstractPurpose:To establish operator‐independent, fully automated planning of standard cardiac geometries and to determine the impact on interstudy reproducibility of cardiac functional parameters.Materials and Methods:Cardiac MR imaging was done in 50 patients referred for left‐ventricular function assessment. In all patients, first standard manual planning was performed followed by automatic planning (AUTO1) and repeat automatic planning (AUTO2) after repositioning the patient to investigate interstudy reproducibility. Cardiac functional parameters were assessed and cine scans were visually graded on a 4‐point scale from nondiagnostic to excellent.Results:Overall success rate of AUTO was 94% with good to excellent geometry planning in >94% of cine standard views. Comparing manual versus fully automated planning, a high agreement of cardiac functional parameters (Lin's concordance correlation coefficient, 0.91 to 0.99) with minimal percent bias (0.24 to 3.84%) was found. In addition, a high interstudy reproducibility of automatic planning was demonstrated (Lin's concordance correlation coefficient, 0.89 to 0.99; percent bias, 0.38 to 5.04%; precision, 3.46 to 9.09%).Conclusion:Fully automated planning of cardiac geometries could reliably be performed in patients showing a variety of cardiovascular pathologies. Standard cardiac geometries were precisely replicated and functional parameters were highly accurate. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Nonenhanced extracranial carotid MR angiography using arterial spin labeling: Improved performance with pseudocontinuous tagging
Authors: Koktzoglou Ioannis , Gupta NavYash , Edelman Robert R. 
Published: July 2011

AbstractPurpose:To compare pulsed arterial spin labeling (PASL) and pseudocontinuous arterial spin labeling (PCASL) for nonenhanced extracranial carotid MR angiography (MRA).Materials and Methods:Parametric signal equations for PASL and PCASL MRA were formulated and compared. Volunteer imaging (n = 7) at 1.5 Tesla was performed to compare the methods over a broad range of repetition and labeling times. Empirical results were compared with theoretical predictions. The feasibility of the optimal method was investigated in patients (n = 2) with sonographically documented carotid artery disease.Results:In volunteers, PCASL provided significantly improved signal than PASL (range: 32–255% improvement; P < 0.01), and better supported the use of long labeling times and short repetition times. Excellent agreement between theory and experiment was found (intraclass correlation coefficient = 0.966; P < 0.001). PCASL provided excellent depiction of the carotid arteries in initial patient studies.Conclusion:Compared with pulsed tagging, pseudocontinuous tagging provides improved performance for nonenhanced extracranial carotid MRA and warrants further clinical investigation. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Kinetic study of OH radical reaction with n‐heptane and n‐hexane at 240–340K using the relative rate/discharge flow/mass spectrometry (RR/DF/MS) technique
Authors: Crawford Mary A. , Dang Bao , Hoang John , Li Zhuangjie 
Published: July 2011

AbstractThe kinetics of reactions of OH radical with n‐heptane and n‐hexane over a temperature range of 240–340K has been investigated using the relative rate combined with discharge flow/mass spectrometry (RR/DF/MS) technique. The rate constant for the reaction of OH radical with n‐heptane was measured with both n‐octane and n‐nonane as references. At 298K, these rate constants were determined to be k1, octane = (6.68 ± 0.48) × 10−12 cm3 molecule−1 s−1 and k1, nonane = (6.64 ± 1.36) × 10−12 cm3 molecule−1 s−1, respectively, which are in very good agreement with the literature values. The rate constant for reaction of n‐hexane with the OH radical was determined to be k2 = (4.95 ± 0.40) × 10−12 cm3 molecule−1 s−1 at 298K using n‐heptane as a reference. The Arrhenius expression for these chemical reactions have been determined to be k1, octane = (2.25 ± 0.21) × 10−11 exp[(−293 ± 37)/T] and k2 = (2.43 ± 0.52) × 10−11 exp[(−481.2 ± 60)/T], respectively. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 489–497, 2011
Patient perceptions of factors leading to spasmodic dysphonia: A combined clinical experience of 350 patients
Authors: Childs Lesley , Rickert Scott , Murry Thomas , Blitzer Andrew , Sulica Lucian 
Published: July 2011

AbstractPurpose:Spasmodic dysphonia (SD) is an idiopathic voice disorder that is characterized by either a strained, strangled voice quality or a breathy voice with aphonic segments of connected speech. It has been suggested that environmental factors play a role in triggering the onset. Clinical observation suggests that some patients associate onset with specific events or factors while others do not. The purpose of this study was to examine a large database of SD patients to determine if specific triggers are associated with the onset of SD.Procedures:Retrospective chart review.Results:A total of 350 charts of patients with SD were identified and were categorized as either “sudden onset” or “gradual onset.” One hundred sixty‐nine recalled their circumstances surrounding onset. Forty‐five percent of these patients described the onset as sudden. Patient perceptions of inciting events in the sudden onset group were identified 77% of the time and 2% of the time in the gradual onset group. The most common factors identified were stress (42%), upper respiratory infection (33%), and pregnancy and parturition (10%).Conclusions:Thirty‐five percent of SD patients perceive their disorder to have a sudden onset with identified inciting events. This prevalence raises questions regarding possible behavioral and environmental factors surrounding the onset of this disorder.
Thermal stability of GaAs photoconductive terahertz antenna
Authors: Jia WanLi , Hou Lei , Chen SuGuo , Hu XianJing , Wang ShaoQiang , Shi Wei 
Published: July 2011

AbstractWe tested the THz intensity, current, and temperature of two kinds of antennas. In the experiment, THz intensity of an antenna went down with time. The instability is caused by the local temperature at the electrode gap. This origins from the decline of the steady state mobility. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2393–2395, 2011; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.26232
Novel Pi‐type stepped‐impedance‐stub branch line and its application to dual‐band power divider with high suppression of intermediate frequencies
Authors: Wu Yongle , Liu Yuanan , Li Shulan , Yu Cuiping 
Published: July 2011

AbstractA novel Pi‐type branch line is constructed by using two shunt stepped‐impedance stubs in this paper. Introducing the stepped‐impedance stubs increases design degrees of freedom of this Pi‐type line. This structure can be used to replace arbitrary single‐section transmission line in microwave components. Meanwhile, by selecting proper parameters according to the given analytical theory, arbitrary dual‐band operations can be realized. To verify the feature of this proposed structure, a dual‐band (1.1 and 1.65 GHz) 3‐dB Wilkinson power divider with measured 50‐dB suppression at the mid band of 1.45 GHz is presented. Finally, experimental results verify the theoretical analysis. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2360–2363, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26266
Breakdown spectroscopy induced by localized microwaves for material identification
Authors: Meir Yehuda , Jerby Eli 
Published: July 2011

AbstractThis letter introduces a localized microwave technique for direct excitation of solid materials for the sake of their identification by atomic emission spectroscopy. The microwave energy is concentrated on the material surface by a microwave‐drill type applicator. The evolved ∼1‐mm3 hotspot is slightly evaporated and excited as plasma. An optical spectrometer measures the atomic emission spectrum, hence enabling the material identification as in the known laser‐induced breakdown spectroscopy (LIBS) technique. The experimental results demonstrate the conceptual feasibility of the localized microwave‐induced breakdown spectroscopy as a low‐cost substitute for the laser‐based LIBS for material identification in scenarios in which a direct contact with the material to be identified and its slight destruction are permitted. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2281–2283, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26272
Factors influencing women's participation in urogynecology research in the UK and USA
Authors: Bakali Evangelia , Gafni‐Kane Adam , Botros Sylvia , Tincello Douglas G. 
Published: July 2011

AbstractAimsTo explore factors influencing willingness to participate in urogynecology trials and explore associations between demographics, quality of life score (ICIQ‐SF), and willingness to participate.MethodsThe Bladder Clinic Questionnaire (BCQ) was developed, piloted, and validated. The BCQ and ICIQ‐SF were distributed to women attending urogynecologists in tertiary referral centers in the UK and USA. The BCQ collected demographic data and data on previous involvement in research and posed eight research scenarios. Women were asked to record their willingness to participate on a Likert scale, collapsed for analysis into “any yes,” “unsure,” or “any no,” giving a BCQ score between 0 and 16 (higher scores indicating greater willingness).ResultsTwo hundred sixty‐seven UK women and 200 US women returned completed questionnaires. Median BCQ score differed between UK and US women (11 [0–16] vs. 10 [0–16]; P = 0.004); median ICIQ score was similar (9 [0–21] vs. 9 [0–20]). ICIQ score was higher in UK women willing to participate in two scenarios: standard operation versus new operation (P = 0.007), and new operation versus new operation (P = 0.001). UK women were uniformly more willing to take part in all scenarios involving established treatments.ConclusionWe identified cultural differences in willingness to participate and differences depending on type of intervention proposed which supports the growing evidence that detailed pilot work is required during planning of intervention studies. Neurourol. Urodynam. Neurourol. Urodynam. 30: 1462–1466, 2011. © 2011 Wiley Periodicals, Inc.
Activation of the striated urethral sphincter to maintain continence during dynamic tasks in healthy men
Authors: Stafford Ryan E. , Ashton‐Miller James A. , Sapsford Ruth , Hodges Paul W. 
Published: July 2011

AbstractAimsFunction of the striated urethral sphincter (SUS) in men is debated. Current evidence is limited to electromyographic (EMG) recordings made with concentric needle electrodes in supine. Understanding of SUS function requires investigation of SUS EMG activity using new recording techniques in dynamic tasks. The aim of this study was to evaluate timing and amplitude of SUS EMG at rest and during dynamic tasks that challenge continence by increasing intra‐abdominal pressure (IAP).MethodsInvestigative study of five healthy men aged 25–39 years. Measurements included SUS, anal sphincter (AS), and transversus abdominus (TrA) EMG, and IAP (recorded with a nasogastric pressure catheter). Participants performed four tasks that challenged postural control in standing (single and repetitive arm movement, stepping and load catching).ResultsIAP amplitude and SUS activity were linearly correlated during repetitive arm movement (R2: 0.67–0.88). During stepping SUS EMG onset preceded the IAP increase, but followed it with rapid arm movements. When the trunk was loaded unpredictably onset of SUS generally followed the increase in IAP. The modest sample size meant only younger men were tested. Future studies might investigate healthy older men or those with certain pathologies.ConclusionsData show that SUS activity increases proportionally with IAP. This provided evidence that SUS contributes to continence when IAP is increased, and that postural control of the trunk involves activation of this muscle. Neurourol. Urodynam. 31:36–43, 2012. © 2011 Wiley Periodicals, Inc.
A galenical of traditional chinese herbal mixture (THC‐002) reduces expression of tachykinin peptides within urethras of spontaneously hypertensive rats
Authors: Ishikawa Masakuni , Imamura Tetsuya , Ishizuka Osamu , Kurizaki Yoshiki , Noguchi Wataru , Zhang Lei , Nishizawa Osamu 
Published: July 2011

AbstractAimsWe investigated expression of tachykinin peptides neurokinin A, neurokinin B, and substance P within urethras of spontaneously hypertensive rats (SHRs) and determined if a traditional Chinese herbal mixture, THC‐002, decreased them.MethodsTen‐ and 40‐week‐old male SHRs were randomly separated into three groups (n = 12 each). Rats of one group were given orally 20 ml 0.9% NaCl solution per kg body weight daily for 1 week. One hour later, each received a similar volume of water. Rats in the second group were also given saline. One hour later, each received 20 mg THC‐002 per kg body weight. The third group was untreated. The urethras were removed and separated into prostatic and non‐prostatic regions and analyzed by real‐time reverse transcription polymerase chain reaction (n = 6) and immunohistochemistry (n = 6).ResultsIn 40‐week‐old untreated SHRs, neurokinin B mRNA and protein, and substance P mRNA in prostatic urethras were significantly higher compared to the 10‐week‐old ones. Neurokinin A mRNA and protein, and substance P protein of the 40‐week‐old saline‐loaded prostatic urethras were significantly higher compared to the 40‐week‐old untreated ones. In 40‐week‐old untreated SHRs, the non‐prostatic urethral neurokinin B protein was significantly higher compared to the 10‐week‐old ones. In 40‐week‐old, saline‐loaded SHRs, neurokinin A protein of the non‐prostatic urethras was significantly higher compared to 40‐week‐old the untreated ones. In 40‐week‐old SHRs, THC‐002 significantly decreased the expression of the urethral tachykinins, except for non‐prostatic urethral neurokinin A mRNA.ConclusionsAging and saline‐loading increased the expression of urethral tachykinin mRNAs and peptides. THC‐002 partially decreased them. Neurourol. Urodynam. 31:201–206, 2012. © 2011 Wiley Periodicals, Inc.