bluuebunny/crossref_metadata_2025_split huggingface dataset:
Positron emission tomography methods with potential for increased understanding of mental retardation and developmental disabilities
Authors: Sundaram Senthil K. , Chugani Harry T. , Chugani Diane C. 
Published: October 2005

AbstractPositron emission tomography (PET) is a technique that enables imaging of the distribution of radiolabeled tracers designed to track biochemical and molecular processes in the body after intravenous injection or inhalation. New strategies for the use of radiolabeled tracers hold potential for imaging gene expression in the brain during development and following interventions. In addition, PET may be key in identifying the physiological consequences of gene mutations associated with mental retardation. The development of high spatial resolution microPET scanners for imaging of rodents provides a means for longitudinal study of transgenic mouse models of genetic disorders associated with mental retardation. In this review, we describe PET methodology, illustrate how PET can be used to delineate biochemical changes during brain development, and provide examples of how PET has been applied to study brain glucose metabolism in Rett syndrome, serotonin synthesis in autism, and GABAA receptors in Angelman's syndrome and Prader–Willi syndrome. Future application of PET scanning in the study of mental retardation might include measurements of brain protein synthesis in fragile X syndrome and tuberous sclerosis complex, two common conditions associated with mental retardation in which cellular mechanisms involve dysregulation of protein synthesis. Mental retardation results in life‐long disability, and application of new PET technologies holds promise for a better understanding of the biological underpinnings of mental retardation, with the potential to uncover new treatment options. © 2005 Wiley‐Liss, Inc. MRDD Research Reviews 2005;11:325–330.
Advanced microscopic imaging methods to investigate cortical development and the etiology of mental retardation
Authors: Haydar Tarik F. 
Published: October 2005

AbstractStudies on human patients and animal models of disease have shown that disruptions in prenatal and early postnatal brain development are a root cause of mental retardation. Since proper brain development is achieved by a strict spatiotemporal control of neurogenesis, cell migration, and patterning of synapses, abnormalities in one or more of these events during prenatal development can lead to cognitive dysfunction after birth. Many of underlying causes of mental retardation must therefore be studied in developing brains. To aid in this research, live imaging using laser scanning microscopy (LSM) has recently allowed neuroscientists to delve deeply into the complex three‐dimensional environment of the living brain to record dynamic cellular events over time. This review will highlight recent examples of how LSM is being applied to elucidate both normal and abnormal cortical development. © 2005 Wiley‐Liss, Inc. MRDD Research Reviews 2005;11:303–316.
Tensile fracture morphologies of nylon‐6/montmorillonite nanocomposites
Authors: Xie Shaobo , Zhang Shimin , Zhao Bin , Qin Huaili , Wang Fosong , Yang Mingshu 
Published: October 2005

AbstractNylon‐6/montmorillonite nanocomposites with different dispersion states of clay and different clay loadings were prepared by melt processing. The nanostructure and mechanical properties were also investigated. The influence of the montmorillonite dispersion state and clay content on the tensile fracture morphology of the injection‐molded nanocomposites was studied by scanning electron microscopy. A rounded ‘cabbage‐like‐sheet’ structure was observed in the fracture surface of the well‐exfoliated nanocomposites, which was absent in the intercalated and poorly dispersed nanocomposite and neat nylon‐6. The formation of this ‘cabbage‐like‐sheet’ pattern has been attributed to the extensive plastic fibrillations of the nylon‐6 matrix, facilitated by the stress concentration and the strengthened effect caused by the well‐exfoliated clay platelets. The change in stiffness caused by the skin–core structure was also considered. The difference in the patterns observed in this present work and those reported by Uribe‐Arocha et al. (Polymer, 44, 2441 (2003)) were discussed, based on the diversity in preparation of the tensile specimens. Copyright © 2005 Society of Chemical Industry
The influence of confinement and curvature on the morphology of block copolymers
Authors: Xiang Hongqi , Shin Kyusoon , Kim Taehyung , Moon Sungin , Mccarthy T. J. , Russell T. P. 
Published: October 2005

AbstractIn the bulk, at equilibrium, diblock copolymers microphase separated into nanoscopic morphologies ranging from body‐centered cubic arrays of spheres to hexagonally packed cylinders to alternating lamellae, depending on the volume fraction of the components. However, when the block copolymers are forced into cylindrical pores, where the diameter of the pores are only several repeat periods of the copolymer morphology or less, then commensurability of the copolymer period and the pore diameter can impose a frustration on the microdomain morphology. In addition, due to the small pore diameter, a curvature is forced on the microdomain morphology. In combination with interfacial interactions between the blocks of the copolymer and the pore walls, the preferential segregation of one component to the walls, spatial confinement and forced curvature are shown to induce transitions in the fundamental morphology of the copolymers seen in the bulk. Lamellar morphologies transformed into torus‐type morphologies, cylinders are forced into helices, and body‐centered cubic arrays of spheres are force into helical arrays of spheres due to these restraints. The novel morphologies, not accesssible in the bulk, open a large array of nanoscopic structures that can be used as templates and scaffolds for the fabrication of inorganic nanostructured materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3377–3383, 2005
Free energy landscape and folding mechanism of a β‐hairpin in explicit water: A replica exchange molecular dynamics study
Authors: Nguyen Phuong H. , Stock Gerhard , Mittag Emil , Hu Chin‐Kun , Li Mai Suan 
Published: October 2005

AbstractThe free energy landscape and the folding mechanism of the C‐terminal β‐hairpin of protein G is studied by extensive replica exchange molecular dynamics simulations (40 replicas and 340 ns total simulation time), using the GROMOS96 force field and the SPC explicit water solvent. The study reveals that the system preferentially adopts a β‐hairpin structure at biologically important temperatures, and that the helix content is low at all temperatures studied. Representing the free energy landscape as a function of several types of reaction coordinates, four local minima corresponding to the folded, partially folded, molten globule, and unfolded states are identified. The findings suggest that the folding of the β‐hairpin occurs as the sequence: collapse of hydrophobic core → formation of H‐bond → formation of the turn. Identifying the folded and molten globule states as the main conformations, the free energy landscape of the β‐hairpin is consistent with a two‐state behavior with a broad transition state. The temperature dependence of the folding–unfolding transition is investigated in some detail. The enthalpy and entropy jumps at the folding transition temperature are found to be about three times lower than the experimental estimates, indicating that the folding–unfolding transition in silico is less cooperative than its in vitro counterpart. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Pulse plasma assisted atomic layer deposition of W–C–N thin films for Cu interconnects
Authors: Kim Yong Tae , Park Ji Ho 
Published: October 2005

AbstractAbstract W–C–N films have been deposited on a tetraethylorthosilicate (TEOS) interlayer dielectric with atomic layer deposition (ALD) cycles of WF6–N2–CH4 gases and the exposure cycles of N2 and CH4 are synchronized with a pulse plasma. The W–C–N films on TEOS layer follow the ALD mechanism, keep a constant deposition rate of 0.2 nm/cycle from 10 to 100 cycles, and have fairly low resistivity (300 µΩ cm). As a diffusion barrier for Cu interconnection the W–C–N films maintain the amorphous phase and no Cu interdiffusion occurs even at 800 °C for 30 min. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Special issue: Advanced optical diagnostics of surfaces, nanostructures and ultrathin films
Authors: Esser Norbert 
Published: October 2005

AbstractThe present special issue of physica status solidi (b) is dedicated to the 65th birthday of Wolfgang Richter, now at University Rome II “Tor Vergata”, and reviews recent achievements in the field of solid state and interface optics on inorganic and organic materials.The cover picture of the issue shows, in the background, a filled state scanning tunneling microscopy (STM) topograph of a GaAs(001)(2 × 4) surface, superimposed by a colour plot of time dependent reflectance anisotropy spectra (RAS). RAS was measured in situ during metal‐organic vapour phase epitaxy (MOVPE) growth of a 6‐fold stack of GaAsN layers on GaAs(001)(2 × 4).
Immunosuppression caused by measles virus: role of viral proteins
Authors: Kerdiles Yann M. , Sellin Caroline I. , Druelle Johan , Horvat Branka 
Published: October 2005

AbstractMeasles virus (MV) causes transient but profound immunosuppression resulting in increased susceptibility to secondary bacterial and viral infections. Due to the development of these opportunistic infections, measles remains the leading vaccine‐preventable cause of child death worldwide. Different immune abnormalities have been associated with measles, including disappearance of delayed‐type hypersensitivity reactions, impaired lymphocyte and antigen‐presenting cell functions, down‐regulation of pro‐inflammatory interleukin 12 production and altered interferon α/β signalling pathways. Several MV proteins have been suggested to hinder immune functions: hemagglutinin, fusion protein, nucleoprotein and the non‐structural V and C proteins. This review will focus on the novel functions attributed to MV proteins in the immunosuppression associated with measles. Here, we highlight new advances in the field, emphasising the interaction between MV proteins and their cellular targets, in particular the cell membrane receptors, CD46, CD150, TLR2 and FcγRII in the induction of immunological abnormalities associated with measles. Copyright © 2005 John Wiley & Sons, Ltd.
Clinical Add‐on: Multiple sclerosis – clinical picture and therapeutic strategies
Authors: Lins Hartmut 
Published: October 2005

AbstractMultiple Sclerosis is a chronic inflammatory disorder of the central nervous system, affecting up to 1.5 % of the population in the US, UK, or Germany. Various subtypes exhibit different patterns of myelin or axonal damage and different stages of inflammation and neurodegeneration. The clinical pictures vary from rare attacks to chronically progressive disability. Current treatment options are mainly immunosuppressive or immunomodulatory [1].
Self‐Assembly of Carbon‐Nanotube‐Based Single‐Electron Memories
Authors: Marty Laëtitia , Bonnot Anne‐Marie , Bonhomme Aurore , Iaia Antonio , Naud Cécile , André Emmanuel , Bouchiat Vincent 
Published: October 2005

AbstractWe demonstrate the wafer‐scale integration of single‐electron memories based on carbon nanotube field‐effect transistors (CNFETs) using a process based entirely on self assembly. First, a “dry” self‐assembly step based on chemical vapor deposition (CVD) allows the growth and connection of CNFETs. Next, a “wet” self‐assembly step is used to attach a single 30‐nm‐diameter gold bead in the nanotube vicinity via chemical functionalization. The bead is used as the memory storage node while the CNFET operating in the subthreshold regime acts as an electrometer exhibiting exponential gain. Below 60 K, the transfer characteristics of gold–CNFETs show highly reproducible hysteretic steps. Evaluation of the capacitance confirms that these current steps originate from the controlled storage of single electrons with a retention time that exceeds 550 s at 4 K.
What Is The Role of Mechanical Bowel Preparation in Patients with Pilonidal Sinus Undergoing Surgery? Prospective, Randomized, Surgeon‐blinded Trial
Authors: Terzi Cem , Canda Aras Emre , Unek Tarkan , Dalgic Esra , Fuzun Mehmet 
Published: October 2005

AbstractThe aim of this study was to determine the effect of a mechanical bowel preparation on postoperative surgical wound infections in patients treated with identical antimicrobial prophylaxis undergoing wide excision and primary closure for chronic pilonidal sinus disease. Patients more than 18 years old were included in the study. All patients had intravenous antimicrobial prophylaxis at the time of anesthesia induction. In a prospective, randomized setting, patients were allocated to either the bowel preparation group or the no‐bowel‐preparation group. Mechanical bowel preparation was performed using an oral sodium phosphate solution. On the morning of the procedure a rectal enema was performed with the phosphate solution. The primary outcome measure was the rate of wound infection, but all postoperative complications and recurrences were recorded. All patients were actively observed for 1 year after discharge. The overall infection rate for the entire study population was 12.8% (13/101) including 14.3% (7/49) of those who had had the bowel preparation and 11.5% (6/52) of those with no bowel preparation. There was no statistically significant difference between groups (P = 0.680). The mean rate of recurrence for all 101 patients was 4.9% (5/101) at 19.2 months (range 12–32 months) of follow‐up. The recurrence rate was 6.1% (3/49) in the bowel preparation group and 3.8% (2/52) in the no‐bowel‐preparation group (P = 1.000). Although the number of patients is small in this study, our results showed that the mechanical bowel preparation does not cause a decrease in the rate of surgical wound infections after excision and primary closure in patients with chronic pilonidal sinus disease.
Evaluation of Effect of Hemihepatic Vascular Occlusion and the Pringle Maneuver during Hepatic Resection for Patients with Hepatocellular Carcinoma and Impaired Liver Function
Authors: Chau Gar‐Yang , Lui Wing‐Yiu , King Kuang‐Liang , Wu Chew‐Wun 
Published: October 2005

AbstractReducing blood loss during resection of hepatocellular carcinoma (HCC) in patients with impaired liver function is important. This study evaluated the effect and safety of inflow occlusion (hemihepatic vascular occlusion and the Pringle maneuver) in reducing blood loss during hepatectomy. A total of 120 HCC patients with impaired liver function (with a preoperative indocyanine green retention rate at 15 minutes > 10%) who underwent hepatectomy were included in this retrospective study. Patients were divided into three groups, no‐occlusion (n = 30), hemihepatic vascular occlusion (n = 49), and Pringle maneuver (n = 41). There was one hospital death in each group. Of all three groups, 50 patients (41.7%) had blood loss less than 1000 ml. The three groups were similar in terms of clinocopathological features. All patients underwent minor resection. Blood loss was significantly greater in the no‐occlusion group; there was no difference between the hemihepatic group and the Pringle group. Multivariate analysis revealed that risk factors related to blood loss included no inflow occlusion [odds ratios (ORs), 2.93; 95% confidence intervals (CIs) 1.13–7.59], tumor centrally located (ORs, 3.85; 95% CIs, 1.50–9.90), serum albumin level < 3.5 gm/dl (ORs, 5.15; 95% CIs, 1.20–22.07), and serum alanine aminotransferase >120 U/l (ORs, 3.58; 95% CIs, 1.19–10.80). For patients with occlusion time ≥ 45 minutes, postoperative serum total bilirubin and aspartate aminotransferase levels in the Pringle group were significantly higher than those in the hemihepatic and no‐occlusion groups (P < 0.05). In HCC patients with impaired liver function undergoing hepatectomy, both hemihepatic vascular occlusion and the Pringle maneuver are safe and effective in reducing blood loss. Patients subjected to hemihepatic vascular occlusion responded better than those subjected to the Pringle maneuver in terms of earlier recovery of postoperative liver function, especially when occlusion time was ≥ 45 minutes.
The Use of Stereotactic Excisional Biopsy in the Management of Invasive Breast Cancer
Authors: Hanna Waël C. , Demyttenaere Sebastian V. , Ferri Lorenzo E. , Fleiszer David M. 
Published: October 2005

AbstractStereotactic breast biopsy techniques minimize the surgical trauma associated with conventional wire‐guided open breast biopsy for non‐palpable breast lesions (NPBLs). Advanced breast biopsy instrumentation (ABBI) allows for a 2‐cm core of breast tissue to be excised under stereotactic guidance in an outpatient setting. We report our initial experience with ABBI. Hospital charts from 89 ABBI procedures between 10/1996 and 07/2002 were retrospectively reviewed for patient characteristics, ABBI parameters, radiographic appearance, pathology, complications, and clinical follow‐up. Data are presented as percentage/median (range). Median age was 59 years (range: 39–80 years), mammographic lesions were classified as calcifications 49% (44/89), soft tissue 39% (35/89), or mixed 11% (10/89). Median radiographic size was 7 mm (1–60 mm). Final pathology revealed ductal carcinoma in situ (DCIS) in 7% (6/89) and invasive cancer in 22% (20/89). Microscopically clear margins were obtained in 55% (11/20) of patients with invasive cancer. Of these, 82% (9/11) chose not to undergo further local surgical therapy. Eight patients remain disease free at 56 months (range: 41–95 months) follow‐up. The ninth patient was deceased at 6 months from an unrelated cause. The overall complication rate was 3% (3/89). A definitive diagnosis was obtained in 100% of malignant and 87% of benign cases. Median waiting time was 19 days (range: 0–90 days). Our experience demonstrates that ABBI is an effective diagnostic tool for NPBLs. It is associated with minimal complications, and provides negative margins in over half of malignant cases. In selected patients with invasive cancer and negative margins, ABBI may obviate the need for further local surgical treatment. ABBI merits additional investigation as a therapeutic modality for early breast cancer.
Access to Care and Satisfaction in Colorectal Cancer Patients
Authors: Porter Geoffrey A. , Inglis Karen M. , Wood Lori A. , Veugelers Paul J. 
Published: October 2005

AbstractThis study described the various components of access to care for resectable colorectal cancer, and correlated the timeliness of these components with patient satisfaction. With a prospective/retrospective cohort design, all patients undergoing surgical resection for primary colorectal cancer from 2/1/01 to 15/12/01, were identified during their admission for surgery. A comprehensive, standardized method of ascertaining specific time intervals, which included a patient interview, was used. A patient satisfaction questionnaire was developed, tested, and used in consenting patients. Over the study period, 118 patients underwent colorectal cancer resection. Of these, 110 (93%) consented to participate and 101 (86%) completed the satisfaction questionnaire, including test–retest. The median time intervals (interquartile range) for the various components of access to care were as follows: symptoms to first physician visit, 32 days (10–75); first physician visit to diagnosis, 88 days (44–218); diagnosis to surgery, 19 days (10–44); surgery to chemotherapy (where applicable), 54 days (47–72). On multivariate analysis, tumor location in the rectum was associated with longer prediagnosis intervals, whereas increasing tumor stage was associated with shorter intervals from diagnosis to surgery. Variation in the time interval from diagnosis to surgery was associated with patient satisfaction (r = 0.49; P < 0.0001). Substantially less correlation was identified between patient satisfaction and the time from first physician visit to diagnosis (r = 0.25, P = 0.04). No significant correlation was identified between patient satisfaction scores and the time interval from symptoms to first physician visit (r = 0.11; P = 0.7). Despite concerns regarding surgical waitlists, the longest time intervals experienced by colorectal cancer patients precede diagnosis. However, variations in the relatively short time period from diagnosis to surgery appeared to have the most impact on patient satisfaction. Interventions which improve the timeliness of specific components of access to care may not necessarily result in improved patient satisfaction.
Reproductive modes of three Ligularia weeds (Asteraceae) in grasslands in Qinghai‐Tibet Plateau and their implications for grassland management
Authors: Ma Rui‐Jun , Du Guo‐Zhen , Lu Bao‐Rong , Chen Jia‐Kuan , Sun Kun , Hara Toshihiko , Li Bo 
Published: October 2005

AbstractLigularia virgaurea, L. sagitta and L. przewalskii are noxious weeds that are widely distributed in psychro‐grasslands in the east of Qinghai‐Tibet Plateau of China. However, little is known about reproductive modes and genetic diversity in the populations of L. virgaurea and L. sagitta under different environmental conditions, although such information is available for L. przewalskii. In this study, two experiments were conducted to examine the ex situ clonal growth of these weeds, and to determine the effects of reproductive modes on the diversity of their populations, using random amplified polymorphic DNA (RAPD) analysis. Transplanted seedlings of L.sagitta and L. virgaurea showed considerable clonal growth by forming rhizomes and ramets. The RAPD analysis showed that all individuals collected from natural populations were genetically different, indicating that no individuals originated from clonal growth. It is concluded that L. virgaurea and L. sagitta have the capacity for clonal growth, but the expression of their clonality is constrained by their growing conditions in natural grasslands. Sexual reproduction plays the major role in their population diversity in natural habitats, which requires that the control measures for these weeds should be targeted at the sexually reproducing populations.
Can collaboration between education and health professionals improve the identification and referral of young people with eating disorders in schools? A pilot study
Authors: Rees Liz , Clark‐Stone Sam 
Published: October 2005

AbstractIn this pilot study, a number of different methods of identifying young people with eating disorders in schools were compared. Pupils aged 16–18 years from 3 schools in the South West of the UK participated (389 boys and 374 girls in total). A self‐report questionnaire (EDE‐Q) was found to be the most effective method of case identification. However, very few of these cases accepted the offer of help and it was strongly suspected that other cases went undetected despite teacher, parent and school nurse guidance. Implications for future early intervention studies are discussed.