bluuebunny/crossref_metadata_2025_split huggingface dataset:
The structure of proteoglycan aggregate determined by atomic force microscopy
Authors: Yeh Ming‐Long , Luo Zong‐Ping 
Published: June 2010

AbstractProteoglycan aggregate is the major extracellular matrix component in cartilage, comprising about 18% of the dry weight of hyaline cartilage. The proteoglycan aggregate is the major substance in cartilage which resists compression in the joint. The purpose of this study was to utilize the newly developed imaging technique, Atomic force Microscopy (AFM), to visualize the ultrastructure of proteoglycan aggregates. The proteoglycan aggregate molecules were imaged in air using the tapping mode of the AFM. The images illustrated the ultrastructure of the aggregates, especially the individual proteoglycan and the core hyaluronic acid. In addition to the length and width of each molecule, the height of the proteoglycan aggregates and the individual proteoglycans could be directly measured. The images of the ultrastructures of proteoglycan aggregates visualized from the AFM are comparable with those using conventional electron microscopy approaches. Nevertheless, the sample preparation for AFM imaging does not involve fixation, staining, coating, and other routine procedures required for traditional electron microscopy imaging. Thus, this technique could be a simple alternative approach for future analysis of proteoglycan aggregate and its assembly.
Steps of Al/Si nanocluster studied by scanning tunneling microscope moiré method
Authors: Shang Haixia , Xie Huimin , Dai Fulong , Xue Qi‐Kun , Jia Jinfeng 
Published: June 2010

AbstractThe surface stress around the steps of Al/Si (111)‐7×7 artificial nanocluster array has been studied by the scanning tunneling microscope (STM) Moiré method. The distributions of σij(εij) near the selected step edge are precisely quantified by Moiré pattern. Observation by STM reveals the details of stress distribution that varies around steps and other defects of the surface. The experimental results show that the intrinsic surface stress tensors are quite different in the upper and lower terraces near a step, which provides indirect evidence that the exchange incorporation occurs for Al atoms on the Si (111) surface. The study also provides valuable data regarding control of the growth mode of artificial nanostructures by manipulating the growth conditions and kinetics.
Cholesterol crystals rupture biological membranes and human plaques during acute cardiovascular events‐a novel insight into plaque rupture by scanning electron microscopy
Authors: Abela George S. , Aziz Kusai 
Published: June 2010

AbstractPlaque rupture and/or erosion are considered the leading cause of cardiovascular events. To elucidate this process, we demonstrated that during cholesterol crystallization the occupied volume increases rapidly and sharp–tipped crystals cut through thin biological membranes in their path. The amount of cholesterol correlated directly with both peak level and rate of crystal growth (r = 0.98; r = 0.99; p < 0.01, respectively). These observations suggest that crystallization of cholesterol in atherosclerotic plaques can induce cap rupture and/or erosion. Observations by scanning electron microscopy confirmed similar findings of cholesterol crystals perforating the lumen surface in human coronary artery segments with ruptured plaque.
Shot noise in electron‐beam lithography and line‐width measurements
Authors: Kruit P. , Steenbrink S. W. H. K. 
Published: June 2010

AbstractElectron‐beam lithography is used extensively in nanoscience and technology for making masks for the semiconductor industry and, on a limited scale, for maskless lithography: that is, writing the patterns directly on the chip. We expect the latter application to extend in the years to come. Control of the dimensions of the written structures is essential in the semiconductor industry. For 45 nm generation, which is presently under development and should reach production at the end of the decade, the required control over the line width is between 1.5 and 5 nm, depending on the application. One of the factors of influence on the line‐width control is the statistics in the number of electrons illuminating the resist. This effect gives line edge roughness, or in other words a lack of control over the local position of a resist edge. This has long been recognized and often discussed. Recently, we developed an analytic model for the line edge position variation, which we shall illustrate and expand in this paper. The model, supported by Monte Carlo simulations, demonstrates that the line‐width variation is inversely proportional to the dose used for the illumination of the resist. This makes it impossible to increase the lithography throughput by developing ultrasensitive resists. For 45 nm features written with a typical resolution of 30 nm, a 30 μC/cm2 resist gives 3 nm line‐width variation over line segments of 45 nm long. The line width is usually measured in an adapted critical dimension scanning electron microscope (CD‐SEM). This measurement needs to be more precise than the result of the lithography step, so the requirements are typically sub‐nm. Apart from all the problems to avoid systematic errors, this measurement also suffers from statistical variations, resulting from the finite number of electrons used for the measurement. In this paper we shall derive an estimate for that variation with a similar model as used for the shot noise effect in the lithography step. One of the conclusions is that for the most precise measurements of the line width it is not advisable to tune the CD‐SEM for the best resolution. It is better to allow a larger probe size of the electron beam because that can be accompanied by a much larger current and thus a decrease in the noise level.
Subcompartmentalized Polymer Hydrogel Capsules with Selectively Degradable Carriers and Subunits
Authors: Kulygin Olga , Price Andrew D. , Chong Siow‐Feng , Städler Brigitte , Zelikin Alexander N. , Caruso Frank 
Published: June 2010

AbstractSubcompartmentalized hydrogel capsules (SHCs) with selectively degradable carriers and subunits are designed for potential applications in drug delivery and microencapsulated biocatalysis. Thiolated poly(methacrylic acid) and poly(N‐vinyl pyrrolidone) are used to assemble 3‐µm‐diameter carrier capsules and 300‐nm‐diameter subunits, independently stabilized by a diverse range of covalent linkages. This paper presents examples of SHCs with tens of subcompartments and their successful drug loading, as well as selective degradation of the SHC carrier and/or subunits in response to multiple chemical stimuli.
Nanog Regulates Primordial Germ Cell Migration Through Cxcr4b
Authors: Sánchez-Sánchez Ana Virginia , Camp Esther , Leal-Tassias Aránzazu , Atkinson Stuart P. , Armstrong Lyle , Díaz-Llopis Manuel , Mullor José L. 
Published: June 2010

Abstract
Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of PGCs and inhibits expression of Cxcr4b in PGCs, where it normally serves as the receptor of Sdf1a to guide PGC migration. Moreover, chromatin immunoprecipitation analysis demonstrates that Ol-Nanog protein binds to the promoter region of Cxcr4b, suggesting a direct regulation of Cxcr4b by Ol-Nanog. Simultaneous overexpression of Cxcr4b mRNA and depletion of Ol-Nanog protein in PGCs rescues the migration defective phenotype induced by a loss of Ol-Nanog, whereas overexpression of Sdf1a, the ligand for Cxcr4b, does not restore proper PGC migration. These results indicate that Ol-Nanog mediates PGC migration by regulating Cxcr4b expression.
Does levator ani injury affect cystocele type?
Authors: Eisenberg V. H. , Chantarasorn V. , Shek K. L. , Dietz H. P. 
Published: June 2010

AbstractObjectiveTo determine the prevalence of levator ani injury in patients with different types of cystocele, as defined by translabial ultrasound, in order to shed light on potential pathophysiological mechanisms.MethodsThe datasets of 222 women who had undergone a physical examination, urodynamic testing and four‐dimensional (4D) pelvic floor ultrasound were evaluated offline for prolapse, levator ani hiatal dimensions and levator ani trauma using tomographic ultrasound imaging (TUI), blinded against all clinical and urodynamic data. Cystoceles reaching below the symphysis pubis on ultrasound examination were classified based on bladder neck position, retrovesical angle (RVA) and urethral rotation as Green II (cystourethrocele) or Green III (cystocele with intact RVA).ResultsOf 102 women who had a cystocele reaching below the symphysis pubis, 63 were classified as a Green type II cystocele and 39 as a Green type III cystocele. Women with Green type III cystoceles were older (59.4 vs. 48.7 years, P < 0.001), and had more severe prolapse (71 vs. 43%, P = 0.004) and objective voiding dysfunction (39 vs. 18%, P = 0.018). Women with Green III cystoceles also had larger hiatal dimensions and were more often diagnosed with an avulsion of the levator ani muscle (69 vs. 35%, P = 0.001).ConclusionA cystocele with an intact RVA is more likely to be associated with avulsion injury of the levator ani muscle and thus more likely to be caused by birth‐related trauma. This contradicts the commonly held belief that such cystoceles are caused by central rather than by lateral fascial defects. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Surgical Mammography Reporting in a Limited Resource Environment
Authors: Mouton John P. , Apffelstaedt Justus , Baatjes Karin 
Published: June 2010

AbstractBackgroundLack of resources and dedicated breast radiology has forced professionals other than radiologists to read mammography. We report a series of surgeon‐read mammography in a developing country.MethodsData were collected prospectively form January 2003 to June 2008 for all mammography performed at a tertiary hospital. The data acquired were demographics, previous treatment for breast pathology, and indication for and outcome of mammography, including diagnostic procedures and their results. The results were benchmarked against standard performance indicators.ResultsOf 8,743 mammograms performed, 1,468 were for palpable lumps; the cancer diagnosis rate was 640 per 1,000 investigations (for 885 of these reported as compatible with malignancy, the cancer diagnosis rate was 95%; for 183 reported as indeterminate 60%, for 400 reported as benign/no abnormality 4%). Of 4,998 cancer follow‐up mammograms, the cancer diagnosis rate was 15 per 1,000. For 76 of these reported as compatible with malignancy, the cancer diagnosis rate was 67%, for 161 reported as indeterminate, the biopsy rate was 36%, and cancer diagnosis rates of biopsy was 41%. Of 75 cancers diagnosed, 26 were locally recurrent after breast conservation and 49 new contralateral primaries, 84% of these were stage 0–I. Of 2,001 mammograms performed for screening, the biopsy rate was 4.5% and the cancer diagnosis rate of biopsy was 27%; the overall cancer diagnosis rate was 11 per 1,000 examinations; 96% of these were stage 0–1.ConclusionsDedicated breast surgeons are equally proficient at mammography interpretation as radiologists. In resource‐restricted environments, nonavailability of dedicated breast radiologists should not preclude development of breast units.
Role of brominated diphenly ether‐209 in the differentiation of neural stem cells in vitro
Authors: Zhang Chunfang , Liu Xianbao , Chen Dunjin 
Published: June 2010

AbstractBrominated diphenly ether‐209 (BDE‐209, decaBDE) is among the most common flame retardants. In a previous study, it was confirmed that exposure to BDE‐209 can decrease learning and memory in mice. However, it is still unknown whether BDE‐209 has an effect on cultured neural stem cells (NSCs). To analyse the role of BDE‐209 in the differentiation of neural stem cells, NSCs obtained from neonatal rats were cultured as neurospheres in DMEM/F12 medium that contained different concentrations of BDE‐209 for 7 days. BDE‐209 was found to inhibit neurite outgrowth and the differentiation of NSCs into neurons in a concentration‐dependent manner. BDE‐209 also enhanced the ratio of differentiation of NSCs into glial cells.
Cytoarchitectural impairments in the medium spiny neurons of theNucleus Accumbenscore of hyperactive juvenile rats
Authors: González‐Burgos I. , García‐Martínez S. , Velázquez‐Zamora D.A. , Ponce‐Rolón R. 
Published: June 2010

AbstractDopaminergic activity in the Nucleus Accumbens has been strongly implicated in the motor hyperactivity associated with Attention deficit hyperactivity disorder. Dopaminergic and glutamatergic terminals converge on the dendritic spines of medium spiny neurons of the nucleus accumbens core, which modulate the excitatory glutamatergic activity. In this work, a Golgi study was carried out to investigate the effects of dopamine depletion on the cytoarchitecture of dendritic spines of nucleus accumbens core medium spiny neurons. The dopaminergic system of newborn male rats was lesioned intracisternally by using 6‐hydroxydopamine, and subsequently, the motor activity, spine density, and the proportion of thin, stubby, mushroom, wide, branched, and double spines was compared to those in control and intact animals. Motor activity was significantly increased in the dopamine‐depleted animals and while the spine density was reduced, there was no change in the proportion of the specific types of spines. Larger thin spines were observed in the dopamine‐depleted animals. Indeed, dopamine depletion may lead to spine retraction due to the disregulation of spine development, and/or an increase in glutamatergic activity. The enlargement of thin spines may suggest a compensatory mechanism to increase the efficiency of synaptic inputs in response to a decrease in spines number. Together, the present findings suggest an alteration to the excitatory/inhibitory balance on dendritic spines of medium spiny neurons of the nucleus accumbens core in hyperactive juvenile rats following early dopamine depletion.
Progress in understanding melanoma propagation
Authors: Shackleton Mark , Quintana Elsa 
Published: June 2010

AbstractMelanoma, like most cancers, is a disease that wreaks havoc mostly through its propensity to spread and establish secondary tumors at sites that are anatomically distant from the primary tumor. The consideration of models of cancer progression is therefore important to understand the essence of this disease. Previous work has suggested that melanoma may propagate according to a cancer stem cell (CSC) model in which rare tumorigenic and bulk non‐tumorigenic cells are organized into stable hierarchies within tumors. However, recent studies using assays that are more permissive for revealing tumorigenic potential indicate that it will not be possible to cure patients by focusing research and therapy on rare populations of cells within melanoma tumors. Studies of the nature of tumorigenic melanoma cells reveal that these cells may gain a growth, metastasis and/or therapy resistance advantage by acquiring new genetic mutations and by reversible epigenetic mechanisms. In this light, efforts to link the phenotypes, genotypes and epigenotypes of melanoma cells with differences in their in vivo malignant potential provide the greatest hope of advancing the exciting progress finally being made against this disease.
Cost analysis of intubation‐related tracheal injury using a national database
Authors: Bhatti Nasir I. , Mohyuddin Atta , Reaven Nancy , Funk Susan E. , Laeeq Kulsoom , Pandian Vinciya , Mirski Marek , Feller‐Kopman David 
Published: June 2010

ObjectiveTo perform risk analysis of tracheal injuries caused by endotracheal intubation (ETI) and to estimate the financial impact of these sequelae.Study DesignCost analysis using a national database.SettingsThe Agency for Healthcare Research and Quality (AHRQ) 2006 National Inpatient Sample.Subjects and MethodsWe identified clinical manifestations and treatments of complications associated with endotracheal tubes and codified them into International Classification of Disease‐ninth revision diagnosis and procedure codes, intentionally excluding alternative etiologies of tracheal injury. Using the AHRQ 2006 National Inpatient Sample, we then compared patients with tracheal injury coded during the medical or surgical stay for length of stay (LOS) and mean hospital cost with diagnosis‐related group (DRG)‐matched controls; we also examined readmissions treating tracheal injury.ResultsTracheal injury presents as tracheal stenosis, tracheomalacia, tracheoesophageal fistula, laryngotracheal ulceration, and vocal cord paralysis. A total of 3232 discharge records met criteria for tracheal injury from ETI within the index hospital stay. Average LOS for patients with tracheal injury (6.3 days; 95% confidence interval [CI] 6.0‐6.3) exceeded LOS in the uncomplicated sample (5.2 days; CI 5.1‐5.3) by 1.1 days. The average hospital cost was $1888 higher with tracheal injury ($10,375 [CI $9762‐$10,988] vs $8487 [CI $8266‐$8669]). LOS for procedures treating prior tracheal injury averaged 4.7 days and cost an average of $11,025 per discharge.ConclusionTracheal injury from ETI is associated with a significant increase in healthcare costs that accrue both during the index admission and during subsequent hospitalizations required to treat the injury.
Poly(glycerol sebacate)‐engineered plugs to repair chronic tympanic membrane perforations in a chinchilla model
Authors: Wieland Aaron M. , Sundback Cathryn A. , Hart Allison , Kulig Katherine , Masiakos Peter T. , Hartnick Christopher J. 
Published: June 2010

ObjectiveTo evaluate the degree of neovascularization and efficacy of repair of chronic tympanic membrane perforations in a chinchilla model using poly(glycerol sebacate) (PGS), a novel bioengineered scaffold material.Study DesignA feasibility study in which chinchilla ears with chronic perforations were randomly assigned to repair with PGS plugs or Gelfilm overlay myringoplasty.SettingInterventions were performed in the animal care facility of a tertiary care academic institution.Subjects and MethodsSixteen adult female chinchillas. Perforations were established under microscopic visualization with thermal cautery. The animals were examined six weeks later, and those ears with stable perforations were randomly assigned to repair with PGS or Gelfilm. All ears were evaluated six weeks after repair, and resected membranes underwent histological evaluation.ResultsChronic perforations were established in 22 of 32 (69%) chinchilla tympanic membranes. Nineteen tympanic membranes were included in the study group (3 ears were excluded secondary to death from anesthesia during the repair); 11 were implanted with PGS, and eight underwent Gelfilm myringoplasty. Of the 11 tympanic membranes implanted with PGS, 10 were healed at six weeks, while six of the eight tympanic membranes repaired with Gelfilm had healed at six weeks. Imaging of the medial mucosal and lateral epithelial surfaces of the tympanic membranes revealed PGS plug incorporation with neovascularization. Histology demonstrated a confluent cell layer on both sides of the graft.ConclusionsPGS plugs are easily placed and allow for perforation closure and graft neovascularization in a chinchilla model.
Detecting cholesteatoma with non‐echo planar (HASTE) diffusion‐weighted magnetic resonance imaging
Authors: Huins Charlie T. , Singh Arvind , Lingam Ravi Kumar , Kalan Ali 
Published: June 2010

ObjectiveThe purpose of this study was to evaluate the diagnostic performance of half‐Fourier‐acquisition single‐shot turbo‐spin‐echo (HASTE) diffusion‐weighted magnetic resonance imaging (DWMRI) in the detection of cholesteatoma.Study DesignProspective blinded comparative study.SettingLondon teaching hospital.Subjects and MethodsSubjects comprised 32 consecutive patients with suspected primary or residual cholesteatoma. HASTE DWMRI was performed on all patients an average of three months before mastoid surgery and evaluated for the presence of cholesteatoma. Radiological findings were correlated with intraoperative findings.ResultsHASTE DWMRI accurately predicted the presence or absence of cholesteatoma in 30 of 32 patients. Residual cholesteatoma was correctly diagnosed by DWMRI in 12 of 14 cases and correctly excluded in six, with two false‐negative results caused by movement artifact and keratin pearls less than 2 mm. All primary cholesteatomas were correctly identified. Sensitivity and specificity were 0.93 (95% confidence interval [CI] 0.75‐0.99) and 1.00 (95% CI 0.54‐1.0), respectively, whereas positive and negative predictive values were 1.00 (95% CI 0.86‐1.00) and 0.75 (95% CI 0.35‐0.97), respectively.ConclusionOur study supports the increasing but small body of evidence that non–echo‐planar imaging (i.e., HASTE) DWMRI performs well in the detection of cholesteatoma. We propose that HASTE DWMRI should be performed on all patients before their second‐look surgery to provide valuable information to the operating surgeon.
Hemostasis in thyroid surgery: Harmonic scalpel versus other techniques—a meta‐analysis
Authors: Ecker Thomas , Carvalho Andre Lopes , Choe Jun‐Ho , Walosek Gudrun , Preuss Klaus Juergen 
Published: June 2010

ObjectiveThe objective is to systematically review the literature studying the harmonic scalpel versus other hemostatic techniques in thyroid surgical patients. Although thyroidectomy is one of the most common surgical procedures, the safest, most efficient, and cost‐effective way to achieve hemostasis is hotly debated.Data SourcesWe searched the electronic databases Medline and the Cochrane Library using relevant search strategies.Review MethodsTwo reviewers (G.W., T.E.) independently assessed titles and abstracts of 72 identified studies. Twelve prospective randomized controlled studies were considered relevant and included in this meta‐analysis (1153 patients).ResultsIn all studies, operating time was reduced by using the harmonic scalpel. Compared with surgical hemostasis by suture ligation or suture/clip ligation combined with electrocauterization or electrothermal bipolar vessel sealer (n = 602), the mean operating time reduction for the harmonic scalpel was equivalent to 22.67 minutes (95% CI, −27.98; −17.37, P < 0.00001) or nearly 25 percent of the total operating room time. When harmonic scalpel was used, blood loss was reduced significantly by 20.03 mL (95% CI, −27.83; −12.22, P < 0.00001), and a mean reduction in postoperative pain (0.86 points [95% CI, −1.60; −0.13, P = 0.02]) was measured. Length of stay was reduced by 0.12 days (95% CI, −0.25; 0.00, P = 0.05). Differences regarding volume of drainage fluid were in favor of harmonic scalpel but not statistically significant; complications were similar in both groups.ConclusionThere is clear evidence that using the harmonic scalpel for hemostasis in thyroid surgery significantly reduces operating time and blood loss and that it is not associated with an increase in volume of drainage fluid, complication rate, or hospital stay.