bluuebunny/crossref_metadata_2025 huggingface dataset:
Enthesitis in an inception cohort of enthesitis‐related arthritis
Authors: Weiss Pamela F. , Klink Andrew J. , Behrens Edward M. , Sherry David D. , Finkel Terri H. , Feudtner Chris , Keren Ron
Published: May 2011

Objective

To describe an enthesitis‐related arthritis (ERA) inception cohort and determine which entheses and joints are most commonly affected.

Methods

We reviewed a retrospective inception cohort study of children with ERA who were diagnosed and treated at The Children's Hospital of Philadelphia between November 2007 and December 2009.

Results

During the study period, there were 32 newly diagnosed ERA patients. Fifty‐nine percent were male, and the median age at the date of initial evaluation was 12.5 years (interquartile range [IQR] 10.2–14.3 years). The median number of tender entheses at presentation was 2 (IQR 0–5), and 21 subjects (66%) had at least 1 tender enthesis. The most prevalent tender entheses were the patellar ligament insertion at the inferior pole of the patella, the plantar fascial insertion at the calcaneus, the Achilles tendon insertion at the calcaneus, and the plantar fascial insertion at the metatarsal heads. Enthesitis was most often symmetric. The median number of active joints was 2 (IQR 0–4). The most commonly affected joints were the sacroiliacs, knees, and ankles. Sacroiliitis, which was defined clinically, was most often symmetric, while peripheral arthritis was most frequently asymmetric. The odds of having active enthesitis at 6 months increased significantly with each additional tender enthesis at the initial evaluation.

Conclusion

Among pediatric patients with ERA, lower extremity enthesitis is prevalent at the time of diagnosis and is likely to persist 6 months later. Future studies should address standardization of the enthesitis examination, the pattern of enthesitis over time, enthesitis response to therapy, and the impact of enthesitis on quality of life.
Luteinized unruptured follicle syndrome increased by inactive disease and selective cyclooxygenase 2 inhibitors in women with inflammatory arthropathies
Authors: Micu Mihaela C. , Micu Romeo , Ostensen Monika
Published: May 2011

Objective

Administration of nonsteroidal antiinflammatory drugs (NSAIDs) may impair fertility. The occurrence of the luteinized unruptured follicle (LUF) syndrome was assessed in women with inflammatory arthropathies exposed to NSAIDs and compared to that in nonexposed women.

Methods

Fourteen patients with inflammatory rheumatic disease, 29 women with noninflammatory musculoskeletal conditions, and 449 women not exposed to NSAIDs were studied by intravaginal ultrasound monitoring for follicular development and ovulation in 1 or more menstrual cycles. Disease activity was assessed in inflammatory rheumatic disease.

Results

In 59 monitored cycles of patients with continuous NSAID exposure, 35.6% of LUF syndromes occurred compared to 3.4% of LUF syndromes in untreated women (P < 0.001). Etoricoxib was responsible for 75% of LUF syndromes in patients exposed continuously, whereas diclofenac generated 15% of LUF syndromes. An ibuprofen dosage of 1,600 mg/day did not induce LUF syndrome either at continuous periovulatory or discontinuous exposure. Interestingly, the frequency of LUF syndrome was 46.2% in patients with inactive inflammatory disease compared to 15% in patients with active disease (P = 0.023). Etoricoxib generated LUF syndrome in 94.2% of the cases with inactive disease versus 28.6% in patients with active disease (P = 0.003).

Conclusion

NSAIDs increased the risk of the LUF syndrome, particularly in patients with inactive disease. The selective cyclooxygenase 2 (COX‐2) inhibitor etoricoxib was a more potent inductor of LUF syndrome than nonselective COX inhibitors. Continuous periovulatory exposure to NSAIDs should be avoided when planning a pregnancy in patients with rheumatic diseases.
Superior CO2 Adsorption Capacity on N‐doped, High‐Surface‐Area, Microporous Carbons Templated from Zeolite
Authors: Xia Yongde , Mokaya Robert , Walker Gavin S. , Zhu Yanqiu
Published: May 2011

Zeolite‐templated, high‐surface‐area, microporous, N‐doped carbons exhibit the highest CO2 uptake capacity recorded to date for any carbon material and one of the highest for any inorganic or organic porous material of up to 6.9 mmol g−1 at 273 K and ambient pressure and 4.4 mmol g−1 at ambient temperature and pressure, along with an initial CO2 adsorption energy of 36 kJ mol−1 at lower coverage and 20 kJ mol−1 at higher CO2 coverage. Combined with their ease of preparation, excellent recyclability and regeneration stability, and high selectivity for CO2, the N‐doped zeolite‐templated carbons are amongst the most promising solid‐state absorbents reported so far for CO2 capture and storage.
Methylglyoxal: (active agent of manuka honey) in vitro activity against bacterial biofilms
Authors: Kilty Shaun J. , Duval Melanie , Chan Francis T. , Ferris Wendy , Slinger Robert
Published: May 2011

Background

Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) biofilms are associated with poor chronic rhinosinusitis (CRS) disease control following surgery. Manuka honey (MH) has been shown to be both an effective in vitro treatment agent for SA and PA biofilms and nontoxic to sinonasal respiratory mucosa. Methylglyoxal (MGO) has been reported to be the major antibacterial agent in MH. The effect of this agent against SA and PA biofilms has yet to be reported. Our objective was to determine the in vitro effect of MGO against biofilms of SA and PA, via in vitro testing of MGO against bacterial biofilms.

Methods

An established biofilm model was used to determine the effective concentration (EC) of MGO against 10 isolates of methicillin‐resistant SA (MRSA) and PA. The EC of MGO was also determined against planktonic (free‐swimming) MRSA and PA.

Results

For MRSA, the EC against planktonic organisms was a concentration of 0.08 mg/mL to 0.3 mg/mL whereas against the biofilm MRSA isolates, the EC ranged from 0.5 mg/mL to 3.6 mg/mL. For PA, the EC against planktonic organisms was a concentration of 0.15 mg/mL to 1.2 mg/mL for planktonic organisms whereas against the biofilm PA isolates, the EC ranged from 1.8 mg/mL to 7.3 mg/mL.

Conclusion

MGO, a component of MH, is an effective antimicrobial agent against both planktonic and biofilm MRSA and PA organisms in vitro.
Ontogenetic Change in Temporal Bone Pneumatization in Humans
Authors: Hill Cheryl A.
Published: May 2011

Pneumatization of the temporal bone is often included in descriptions of fossils and as a phylogenetic marker, but a number of questions about the evolution, growth, and development of the trait remain. Many studies have analyzed temporal bone pneumatization from a clinical perspective, but a systematic quantification of normal development of pneumatized spaces has not been conducted. In this study, ontogenetic change in the size and organization of temporal bone pneumatization is analyzed in a cross‐sectional sample of humans. High resolution computed tomography scans of the temporal bone were acquired from a cross‐sectional sample of humans (N = 28). Bone volume fractions, anisotropy, trabecular number, trabecular thickness, surface area, and volume were analyzed to provide information about the organization and size of pneumatized spaces across ontogeny. The results indicate that there are general and region‐specific patterns of ontogenetic changes in the organization of pneumatized spaces. These changes reflect the transition from nonpneumatized bone to pneumatized bone. It also demonstrates that those regions that are pneumatized early in ontogeny (such as the mastoid antrum) continue to remodel after the initial period of pneumatization. The dynamic nature of temporal bone pneumatization over ontogeny suggests that this character requires careful consideration when used as a character for phylogenetic analyses. These results demonstrate the importance of comparing individuals from similar developmental stages, especially when completing quantitative analyses of the extent of pneumatization or organization of the spaces. Anat Rec,, 2011. © 2011 Wiley‐Liss, Inc.
Effect of Monochromatic Light on Melatonin Secretion and Arylalkylamine N‐Acetyltransferase mRNA Expression in the Retina and Pineal Gland of Broilers
Authors: Jin Erhui , Jia Liujun , Li Jian , Yang Guang , Wang Zixu , Cao Jing , Chen Yaoxing
Published: May 2011

The goal of this study is to investigate the effects of various monochromatic lights on plasma melatonin (MT) levels and the expression of arylalkylamine N‐acetyltransferase (AANAT) mRNA in the pineal gland and retina. A total of 160 newly hatched (posthatching day 1, P1) broilers, including intact, sham‐operated, and pinealectomized groups were exposed to blue light (BL), green light (GL), red light (RL), and white light (WL) by light emitting diode (LED) system for short term (24 hr) or long term (2 weeks), separately. For intact and sham‐operated birds, the plasma MT level exhibited marked circadian rhythms at P7 and P14 regardless of short‐term and long‐term exposure to four monochromatic lights. However, WL and BL showed a faint suppression of MT secretion in contrast to GL and RL at either light or dark time points, with the following rank order: GL < RL < WL < BL. Larger circadian amplitude of MT levels was observed in GL group versus BL group (at P14: 87.70 pg/mL vs. 19.85 pg/mL, respectively). Pinealectomy disturbed the MT rhythm under different light colors, especially in RL. Additionally, consistent with the alteration of plasma MT levels, we observed increased AANAT mRNA expression and immunoreactive cell numbers of proliferating cell nuclear antigen (PCNA) and c‐Fos in the pineal gland or retina in GL than that of BL, whereas 5‐HT immunoreactive cell number was significantly decreased in GL. These data suggested that GL enhanced chick pinealocytes and retinal cells to express AANAT mRNA and to secrete MT, which may be depended on promoting c‐Fos expression and cell proliferation. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis and In‐vitro Antimicrobial Activity of Secondary and Tertiary Amines Containing 2‐Chloro‐6‐methylquinoline Moiety
Authors: Kumar Suresh , Bawa Sandhya , Kaushik Darpan , Panda Bibhu P.
Published: May 2011

A number of secondary and tertiary amines bearing 2‐chloro‐6‐methylquinoline were synthesized by nucleophilic substitution reaction of 3‐(chloromethyl)‐2‐chloro‐6‐methylquinoline with substituted aromatic primary and secondary amines in presence of catalytic amount of triethylamine (TEA) and K2CO3. All the compounds were characterized by combined use of IR, 1H‐NMR, 13C‐NMR, mass spectral data, and microanalyses. The newly synthesized quinolinyl amines were screened in vitro for their antifungal activity against Aspergillus niger MTCC 281, Aspergillus flavus MTCC 277, Monascus purpureus MTCC 369, Penicillium citrinum NCIM 768 and for antibacterial activity strains viz. Escherichia coli NCTC 10418, Staphylococcus aureus NCTC 65710, and Pseudomonas aeruginosa NCTC 10662 by agar diffusion technique. Results of the preliminary screening revealed that some of the compounds mainly those with electron withdrawing groups in the phenyl ring showed promising antifungal activity.
Surgeons as medical school educators: An untapped resource
Authors: Haubert Lisa M. , Way David , DePhilip Robert , Tam Marty , Bishop Julie , Jones Kenneth , Moffatt‐Bruce Susan D.
Published: May 2011

Despite extensive experience teaching residents, surgeons are an untapped resource for educating medical students. We hypothesized that by involving surgeons as teachers earlier in the medical school curriculum, medical students' interest in surgery will increase and their opinions of surgeons will improve. Five programs designed to involve surgeons as educators in the medical school curriculum were implemented. The first program, started in 2008, introduced surgical faculty into the first‐year medical student anatomy dissection laboratories. Other programs initiated in 2008 included: Surgical Clinical Correlates in Anatomy, which involved faculty teaching through cadaver surgery; Clinical Pathologic Conferences in Anatomy, a surgeon‐led conference based on clinical cases; and a women's faculty‐student mentorship program. Table Rounds, a surgeon‐led anatomy review that used clinical scenarios to quiz students was begun in 2009. All five programs were successfully integrated into the medical school curriculum. While student opinion of surgeons as educators improved, there were no significant changes in student interest in surgery as a career nor change in performance on written examinations over the Anatomy content covered by the surgeons. Surgical faculty and trainees can be integrated into the medical school curriculum. Involving surgeons as educators earlier in the medical school curriculum may have longer term effects than could be observed in this study. At a minimum, the experience improved student opinion of surgeons as educators. Anat Sci Educ. © 2011 American Association of Anatomists.
Medical students' perceptions of the body donor as a “First Patient” or “Teacher”: A pilot study
Authors: Bohl Michael , Bosch Peter , Hildebrandt Sabine
Published: May 2011

University of Michigan Medical School (UMMS) students attending a seminar on the history and ethics of anatomical dissection were fascinated by a report on the dissection room experience in Thailand that relates the body donor's status as a teacher. The students felt that they had naturally adopted the “body as teacher” approach in their dissection course, rather than the “body as first patient” approach that is encouraged by faculty. It was decided to explore the question whether other medical students shared these perceptions. A questionnaire was sent out to all UMMS students who had finished the anatomical dissection course. One hundred twenty‐eight responses from a population of 500 students were received. Results indicate that students believe the “body as teacher” approach is more effective in engendering respect and empathy towards the body and towards future patients, and in facilitating students' emotional development. Students also reported wanting a more personal relationship with their donors. Eighty four percent of students preferred the “body as teacher” approach to the currently taught “body as first patient” approach. The results support the hypothesis that students' desired closer personal relationship with donors might be better facilitated by the "body as teacher" approach, and that this closer relationship engenders empathy and respect towards the donor and future patients. A new model for anatomy programs could introduce the donor first as a teacher and later transition into viewing the donor as a patient. Anat Sci Educ. © 2011 American Association of Anatomists.
Yield stress of pretreated corn stover suspensions using magnetic resonance imaging
Authors: Lavenson David M. , Tozzi Emilio J. , McCarthy Michael J. , Powell Robert L.
Published: May 2011

Cellulose fibers in water form networks that give rise to an apparent yield stress, especially at high solids contents. Measuring the yield stress and correlating it with fiber concentration is important for the biomass and pulp industries. Understanding how the yield stress behaves at high solids concentrations is critical to optimize enzymatic hydrolysis of biomass in the production of biofuels. Rheological studies on pretreated corn stover and various pulp fibers have shown that yield stress values correlate with fiber mass concentration through a power‐law relationship. We use magnetic resonance imaging (MRI) as an in‐line rheometer to measure velocity profiles during pipe flow. If coupled with pressure drop measurements, these allow yield stress values to be determined. We compare our results with literature values and discuss the accuracy and precision of the rheo‐MRI measurement, along with the effects of fiber characteristics on the power‐law coefficients. Biotechnol. Bioeng. 2011;108: 2312–2319. © 2011 Wiley Periodicals, Inc.
Risk factors for conversion and complications after unilateral laparoscopic adrenalectomy
Authors: Gaujoux S , Bonnet S , Leconte M , Zohar S , Bertherat J , Bertagna X , Dousset B
Published: May 2011

Background

Laparoscopic adrenalectomy (LA) is the procedure of choice for surgical management of most benign adrenal tumours, with a reported overall complication rate around 10 per cent. The aim of this study was to determine predictive factors for postoperative complications and conversion to open surgery after unilateral LA.

Methods

From 1994 to 2009, consecutive patients undergoing unilateral LA by the lateral transabdominal approach were analysed from a prospectively maintained database. A mass larger than 12 cm in diameter and suspected primary adrenal carcinoma were considered contraindications to LA. Predictive factors for postoperative complications and conversion to open surgery were analysed.

Results

Some 462 patients were analysed. There were no postoperative deaths. Postoperative complications occurred in 53 patients (11·5 per cent), medical complications in 28, and surgical complications in 33 patients. Six patients underwent reoperation for complications. Multivariable logistic regression analysis showed that conversion to open surgery (odds ratio (OR) 6·20, 95 per cent confidence interval 2·08 to 18·53; P = 0·001) and left-sided tumour (OR 1·89, 1·02 to 3·52; P = 0·044) were independent predictive factors for overall complications. Conversion to open surgery was the only independent predictive factor for medical complications (OR 12·88, 4·21 to 39·41; P = 0·001), and left-sided LA was the only predictive factor for surgical complications (OR 2·22, 1·01 to 4·89; P = 0·047). No factor was predictive of conversion to open surgery.

Conclusion

In this single-institution study, conversion to open surgery and left-sided tumours were independent predictive factors for overall complications, but none of the variables analysed was predictive of conversion.
Solvent and TMEDA Effects on the Configurational Stability of Chiral Lithiated Aryloxiranes
Authors: Perna Filippo Maria , Salomone Antonio , Dammacco Mariangela , Florio Saverio , Capriati Vito
Published: May 2011

The employment of hexane/N,N,N′,N′‐tetramethylethylenediamine (TMEDA) dramatically hinders the racemization of those lithiated styrene oxides (trifluoromethyl‐, chloro‐, and phenylthio‐substituted) that have been proven to be configurationally unstable in THF on the timescale of their reactions. The barriers to inversion and the activation parameters, calculated (Eyring equation) for reactions performed in THF, THF/TMEDA, and hexane/TMEDA, suggest the intervention of particular enantiomerization mechanisms for each case. The role of TMEDA in both coordinating and noncoordinating solvents has also been questioned and discussed in light of the kinetic data gathered and a model for deprotonation in hexane/TMEDA has also been proposed. The synthetic benefits of our results became apparent on establishing an asymmetric synthesis of an industrially important antifungal agent.
A 18F‐Labeled Fluorobutyl‐Substituted Spirocyclic Piperidine Derivative as a Selective Radioligand for PET Imaging of Sigma1 Receptors
Authors: Maisonial Aurélie , Große Maestrup Eva , Fischer Steffen , Hiller Achim , Scheunemann Matthias , Wiese Christian , Schepmann Dirk , Steinbach Jörg , Deuther‐Conrad Winnie , Wünsch Bernhard , Brust Peter
Published: May 2011

In this study, we synthesized and evaluated a new spirocyclic piperidine derivative 3, containing a 4‐fluorobutyl side chain, as a PET radioligand for neuroimaging of σ1 receptors. In vitro, compound 3 displayed high affinity for σ1 receptors (Ki=1.2 nM) as well as high selectivity. [18F]3 radiosynthesis was performed from the corresponding tosylate precursor, with high radiochemical yield (45–51 %), purity (>98 %), and specific activity (>201 GBq μmol−1). Metabolic stability of [18F]3 in the brain of CD‐1 mice was verified, and no penetration of peripheral radiometabolites into the cerebral tissue was observed. Results of ex vivo autoradiography revealed that the distribution of [18F]3 in the brain corresponded to regions with high σ1 receptor density. The highest region‐specific total‐to‐nonspecific ratio was determined in the facial nucleus (4.00). Biodistribution studies indicated rapid and high levels in brain uptake of [18F]3 (2.2 % ID per gram at 5 min p.i.). Pre‐administration of haloperidol significantly inhibited [18F]3 uptake into the brain and σ1 receptor‐expressing organs, further confirming in vivo target specificity.
Antagonism of the Stat3–Stat3 Protein Dimer with Salicylic Acid Based Small Molecules
Authors: Fletcher Steven , Page Brent D. G. , Zhang Xialoei , Yue Peibin , Li Zhi Hua , Sharmeen Sumaiya , Singh Jagdeep , Zhao Wei , Schimmer Aaron D. , Trudel Suzanne , Turkson James , Gunning Patrick T.
Published: May 2011

More than 50 new inhibitors of the oncogenic Stat3 protein were identified through a structure–activity relationship (SAR) study based on the previously identified inhibitor S3I‐201 (IC50=86 μM, Ki>300 μM). A key structural feature of these inhibitors is a salicylic acid moiety, which, by acting as a phosphotyrosine mimetic, is believed to facilitate binding to the Stat3 SH2 domain. Several of the analogues exhibit higher potency than the lead compound in inhibiting Stat3 DNA binding activity, with an in vitro IC50 range of 18.7–51.9 μM, and disruption of Stat3–pTyr peptide interactions with Ki values in the 15.5–41 μM range. One agent in particular exhibited potent inhibition of Stat3 phosphorylation in both breast and multiple myeloma tumor cells, suppressed the expression of Stat3 target genes, and induced antitumor effects in tumor cells harboring activated Stat3 protein.
A reassessment of whether cortical motor neurons die following spinal cord injury
Authors: Nielson Jessica L. , Strong Melissa K. , Steward Oswald
Published: May 2011

Over the past century, the question of whether the cells of origin of the corticospinal tract (CST) die following spinal cord injury (SCI) has been debated. A recent study reported an approximately 20% loss of retrogradely labeled cortical motoneurons following damage to their axons resulting from SCI at T9 (Hains et al. [2003] J. Comp. Neurol. 462:328–341). In follow‐up studies, however, we failed to find any evidence of loss of CST axons in the medullary pyramid, which must occur if CST neurons die. Here, we seek to resolve the discrepancy by re‐evaluating possible loss of CST neurons using the same techniques as Hains et al. (quantitative analysis of retrograde labeling and staining for cell death markers including TUNEL and Hoechst labeling of the nuclei). Following either dorsal funiculus lesions at thoracic level 9 (T9) or lateral hemisection at cervical level 5 (C5), our results reveal no evidence for a loss of retrogradely labeled neurons and no evidence for TUNEL staining of axotomized cortical motoneurons. These results indicate that CST cell bodies do not undergo retrograde cell death following SCI, and therefore targeting such cell death is not a valid therapeutic target. J. Comp. Neurol. 519:2852–2869, 2011. © 2011 Wiley‐Liss, Inc.
Morphological and functional characterization of cholinergic interneurons in the dorsal horn of the mouse spinal cord
Authors: Mesnage Bruce , Gaillard Stéphane , Godin Antoine G. , Rodeau Jean‐Luc , Hammer Matthieu , Von Engelhardt Jakob , Wiseman Paul W. , De Koninck Yves , Schlichter Rémy , Cordero‐Erausquin Matilde
Published: May 2011

Endogenous acetylcholine is an important modulator of sensory processing, especially at the spinal level, where nociceptive (pain‐related) stimuli enter the central nervous system and are integrated before being relayed to the brain. To decipher the organization of the local cholinergic circuitry in the spinal dorsal horn, we used transgenic mice expressing enchanced green fluorescent protein specifically in cholinergic neurons (ChAT::EGFP) and characterized the morphology, neurochemistry, and firing properties of the sparse population of cholinergic interneurons in this area. Three‐dimensional reconstruction of lamina III ChAT::EGFP neurons based either on their intrinsic fluorescence or on intracellular labeling in live tissue demonstrated that these neurons have long and thin processes that grow preferentially in the dorsal direction. Their dendrites and axon are highly elongated in the rostrocaudal direction, beyond the limits of a single spinal segment. These unique morphological features suggest that dorsal horn cholinergic interneurons are the main contributors to the plexus of cholinergic processes located in lamina IIi, just dorsal to their cell bodies. In addition, immunostainings demonstrated that dorsal horn cholinergic interneurons in the mouse are γ‐aminobutyric acidergic and express nitric oxide synthase, as in rats. Finally, electrophysiological recordings from these neurons in spinal cord slices demonstrate that two‐thirds of them have a repetitive spiking pattern with frequent rebound spikes following hyperpolarization. Altogether our results indicate that, although they are rare, the morphological and functional features of cholinergic neurons enable them to collect segmental information in superficial layers of the dorsal horn and to modulate it over several segments. J. Comp. Neurol. 519:3139–3158, 2011. © 2011 Wiley‐Liss, Inc.
Connections of the terminal nerve and the olfactory system in two galeomorph sharks: An experimental study using a carbocyanine dye
Authors: Yáñez Julián , Folgueira Mónica , Köhler Elisabeth , Martínez Cristina , Anadón Ramón
Published: May 2011

In elasmobranchs the terminal nerve courses separately from the olfactory nerve. This characteristic makes elasmobranchs excellent models to study the anatomy and function of these two systems. Here we study the neural connections of the terminal nerve and olfactory system in two sharks by experimental tracing methods using carbocyanine dyes. The main projections from the terminal nerve system (consisting of three ganglia in Scyliorhinus canicula) course ipsilaterally to the medial septal nucleus and bilaterally to the ventromedial telencephalic pallial region. Minor terminal nerve projections were also traced ipsilaterally to diencephalic and mesencephalic levels. With regard to the olfactory connections, our results show that in sharks, unlike ray‐finned fishes, the primary olfactory projections are mainly restricted to the olfactory bulb. We also performed tracer application to the olfactory bulb in order to analyze the possible central neuroanatomical relationship between the projections of the terminal nerve and the olfactory bulb. In these experiments labeled neurons and fibers were observed from telencephalic to caudal mesencephalic regions. However, we observe almost no overlap between the two systems at central levels. The afferent and the putatively efferent connections of the dogfish olfactory bulb are compared with those previously reported in other elasmobranchs. The significance of the extratelencephalic secondary olfactory projections is also discussed in a comparative context. J. Comp. Neurol. 519:3202–3217, 2011. © 2011 Wiley‐Liss, Inc.
Segregation of feedforward and feedback projections in mouse visual cortex
Authors: Berezovskii Vladimir K. , Nassi Jonathan J. , Born Richard T.
Published: May 2011

Hierarchical organization is a common feature of mammalian neocortex. Neurons that send their axons from lower to higher areas of the hierarchy are referred to as “feedforward” (FF) neurons, whereas those projecting in the opposite direction are called “feedback” (FB) neurons. Anatomical, functional, and theoretical studies suggest that these different classes of projections play fundamentally different roles in perception. In primates, laminar differences in projection patterns often distinguish the two projection streams. In rodents, however, these differences are less clear, despite an established hierarchy of visual areas. Thus the rodent provides a strong test of the hypothesis that FF and FB neurons form distinct populations. We tested this hypothesis by injecting retrograde tracers into two different hierarchical levels of mouse visual cortex (area 17 and anterolateral area [AL]) and then determining the relative proportions of double‐labeled FF and FB neurons in an area intermediate to them (lateromedial area [LM]). Despite finding singly labeled neurons densely intermingled with no laminar segregation, we found few double‐labeled neurons (≈5% of each singly labeled population). We also examined the development of FF and FB connections. FF connections were present at the earliest timepoint we examined (postnatal day 2, P2), while FB connections were not detectable until P11. Our findings indicate that, even in cortices without laminar segregation of FF and FB neurons, the two projection systems are largely distinct at the neuronal level and also differ with respect to the timing of their axonal outgrowth. J. Comp. Neurol. 519:3672–3683, 2011. © 2011 Wiley‐Liss, Inc.
Slow Photoelectron Spectroscopy of δ‐Valerolactam and Its Dimer
Authors: Mahjoub Ahmed , Hochlaf Majdi , Poisson Lionel , Nieuwjaer Nicolas , Lecomte Frédéric , Schermann Jean‐Pierre , Grégoire Gilles , Manil Bruno , Garcia Gustavo A. , Nahon Laurent
Published: May 2011

We studied the single‐photon ionization of gas‐phase δ‐valerolactam (piperidin‐2‐one) and of its dimer using vacuum‐ultraviolet (VUV) synchrotron radiation coupled to a velocity map imaging electron/ion coincidence spectrometer. The slow photoelectron spectrum (SPES) of the monomer is dominated by the vibrational transitions to the ${{\rm{\tilde X}}}$ state. Moreover, several weaker and complex bands are observed, corresponding to the population of the vibrational bands (pure or combination) of the electronically excited states of the cation arising from their mutual vibronic interactions. For the dimer, we measure a unique large band. These spectra are assigned with the help of theoretical calculations dealing with the equilibrium geometries, electronic‐state patterns and evolutions, harmonic and anharmonic wavenumbers of the monomer and dimer, either neutral or positively charged. The state energies of the [δ‐valerolactam]+ cation in the ${{\rm{\tilde X}}}$ ground, ${{\rm{\tilde A}}}$, ${{\rm{\tilde B}}}$ and ${{\rm{\tilde C}}}$ excited electronic states, and of the [δ‐valerolactam]2+ cation′s lowest states are determined. After its formation, [δ‐valerolactam]2+ is subject to intramolecular isomerization, H transfer and then unimolecular fragmentation processes. Close to the ionization thresholds, the photoionization of these molecules is found to be mainly dominated by a direct process whereas the indirect route (autoionization) contributes at higher energies.
A microflow cytometer exploited for the immunological differentiation of leukocytes
Authors: Frankowski Marcin , Bock Nicole , Kummrow Andreas , Schädel‐Ebner Sandra , Schmidt Martin , Tuchscheerer Andrej , Neukammer Jörg
Published: May 2011

In this article, we demonstrate the potential of a microfluidic chip for the differentiation of immunologically stained blood cells. To this end, white blood cells stained with antibodies typically applied for the determination of the immune status were measured in the micro‐device. Relative concentrations of lymphocytes and subpopulations of lymphocytes are compared to those obtained with a conventional flow cytometer. The stability of the hydrodynamic focusing and the optical setup was determined by measuring the variation of the signal pulse height of fluorescence calibration beads, being about 2% for the micro‐device. This value and the overall performance of the micro‐device are similar to conventional flow cytometers. It follows from our results that such microfluidic structures are well suited as modules in a compact, portable read‐out instrument. The production process of the microflow cytometers, which we exploited for immunological cell differentiation, is compatible with mass production technology like injection molding and, hence, low cost disposable chips could be available in the future. © 2011 International Society for Advancement of Cytometry
Flow cytometry immunophenotyping for the evaluation of bone marrow dysplasia
Authors: Della Porta Matteo Giovanni , Lanza Francesco , Del Vecchio Luigi ,   for the Italian Society of Cytometry (GIC)
Published: May 2011

The pathological hallmark of myelodysplastic syndromes (MDS) is marrow dysplasia, which represents the basis of the WHO classification of these disorders. This classification provides clinicians with a useful tool for defining the different subtypes of MDS and determining individual prognosis. The WHO proposal has raised some concern regarding minimal diagnostic criteria particularly in patients with normal karyotype without robust morphological markers of dysplasia (such as ring sideroblasts or excess of blasts). Therefore, there is clearly a need to refine the accuracy to detect marrow dysplasia. Flow cytometry (FCM) immunophenotyping has been proposed as a tool to improve the evaluation of marrow dysplasia. Rationale for the application of FCM in the diagnostic work up of MDS is that immunophenotyping is an accurate method for quantitative and qualitative evaluation of hematopoietic cells and that MDS have been found to have abnormal expression of several cellular antigens. To become clinically applicable, FCM analysis should be based on parameters with sufficient specificity and sensitivity, data should be reproducible between different operators and the results should be easily understood by clinicians. In this report, we reviewed the most relevant progresses in detection of marrow dysplasia by FCM in MDS as defined by WHO criteria. © 2011 International Clinical Cytometry Society
Maximized achievable rate of SINR‐measurement‐based spectrum sharing with binary feedback
Authors: Wang Hanho , Ko Kyunbyoung , Woo Choongchae
Published: May 2011

Motivated by the difficulty in measuring channel state information between heterogeneous primary and secondary systems, we propose a signal‐to‐interference‐noise ratio (SINR)‐based spectrum sharing policy. In the proposed spectrum sharing policy, a secondary user who does not cause SINR outage at the primary receiver is admitted to share the primary user's spectrum. In this article, we analyze the achievable rate of a secondary user and for whom the achievable rate is maximized in the SINR‐constrained spectrum sharing. The maximized achievable rate is determined by the ratio of the distance between the secondary transmitter and the primary receiver to the distance between the secondary transmitter and receiver, and it is proportional to the distance ratio. In conclusion, secondary links with large distance ratio can support high data rate applications so long as SINR constraint of the primary user is guaranteed. Copyright © 2011 John Wiley & Sons, Ltd.
Methomyl Detection by Inhibition of Laccase Using a Carbon Ceramic Biosensor
Authors: Cadorin Fernandes Suellen , Cruz Vieira Iolanda , Barbosa Antonio Marcos Jacques , Souza Ferreira Valdir
Published: May 2011

A sol–gel derived carbon ceramic biosensor was used for methomyl determination in vegetable extract samples based on the immobilization of laccase from Aspergillus oryzae. Esculetin was chosen as the substrate for laccase in order to measure inhibition by this pesticide. The analytical curve was linear for methomyl concentrations of 0.5 to 12.2 µM with a detection limit of 0.2 µM. The lifetime of the proposed biosensor was 60 days and the recovery from vegetable extract samples ranged from 98.0 to 104.2 %. The results using the proposed method are in agreement with those using HPLC at the 95 % confidence level.
Electrochemical DNA Hybridization Assay: Enzyme‐Labeled Detection of Mutation in p53 Gene
Authors: Gupta Gautam , Atanassov Plamen
Published: May 2011

This paper discusses a new electrochemical DNA hybridization sensing approach based on the detection of a linked enzyme label. In this method we employ enzyme that is attached to a tethered ssDNA oligomer on the surface and the target analyte is a complementary ssDNA oligomer that does not require any pre‐treatment. The advantage of using of enzyme label is in its amplification of the registration of the hybridization event due to the catalytic reaction facilitated in the process. One particular novelty is associated with the use of enzymes that directly communicate with the electrode surface thus allowing for minimizing the need of additional reagents in the assay. The electrochemical assay was demonstrated when using mixed self‐assembled monolayers from thiolated oligonucleotide and 6‐mercapto 1‐hexanol on gold surfaces. Horseradish peroxidase (HRP) is attached to the surface tethered oligonucleotide using streptavidin‐biotin chemistry, and the enzyme successfully established direct electron transfer (DET) with the electrode or mediated electron transfer (MET) using a mediator. Hybridization results in increasing the angle of contact between electrode and DNA and also the stiffness of the ds DNA, which results in displacing the enzyme away from the electrode surface, and thereby reducing the occurrence of direct electron transfer between the enzyme and the electrode. The cyclic voltammetry showed a clear distinction in response between the complete complementary sequence and the two‐base mismatch sequence. Ellipsometric measurements show that the thickness of the thiol modified oligonucleotide on gold surfaces changes before and after hybridization for the complementary sequence, where as a minimal change in thickness was observed for the noncomplementary sequence. The model target analyte in this study was TP53 gene where a specific mutation is a marker for a list of cancers. Mutations of the TP53 gene have been demonstrated in tumors of the colon, breast, lung, ovary, bladder, and many other organs. Analysis of p53 mutations may provide useful information for the diagnosis, prognosis and therapy of cancer.
Enhanced Electron Transfer Rates by AC Voltammetry for Ferrocenes Attached to the End of Embedded Carbon Nanofiber Nanoelectrode Arrays
Authors: Syed Lateef U , Liu Jianwei , Prior Allan M. , Hua Duy H. , Li Jun
Published: May 2011

The effect of the interior structure of carbon nanomaterials on their electrochemical properties is not well understood. We report here the electron transfer rate (ETR) of ferrocene (Fc) molecules covalently attached to the exposed end of carbon nanofibers (CNFs) in an embedded nanoelectrode array. The ETR in normal DC voltammetry was found to be limited by the conical graphitic stacking structure interior of CNFs. AC voltammetry, however, can cope with this intrinsic materials property and provide over 100 times higher ETR, likely by a new capacitive pathway. This provides a new method for high‐performance electroanalysis using CNF nanoelectrodes.
Voltammetric Discrimination of DNA Single Base‐Pair Mismatches via Taq DNA Ligase‐Based Mismatch Recognition
Authors: Kim Jun Myung , Koo Chong Min , Kim Joohoon
Published: May 2011

An electrochemical approach for single base‐specific detection of label‐free target single‐strand DNA (ssDNA) was demonstrated. The approach was based on the high ligation selectivity of Taq DNA ligase coupled with ferrocenated gold nanoparticle/streptavidin conjugate‐based voltammetric detection method. The ferrocene (Fc) moieties of Fc‐capped gold nanoparticle/streptavidin conjugates, which were selectively bound to the biotinylated DNA layer, were found to be close enough to the underlying electrode surface for facile electron transfer. The proposed electrochemical method was evaluated with label‐free target DNA strands making all possible base pair combinations at the 3′‐OH side of capture probe, and showed significant voltammetric signals only with a perfect match target strand.
Electrochemical Determination of Cu(II) Ions by 4‐Formylphenylboronic Acid Modified Gold Electrode
Authors: Oztekin Yasemin , Ramanaviciene Almira , Ramanavicius Arunas
Published: May 2011

A self‐assembled monolayer (SAM) modified by 4‐formylphenylboronic acid was formed on the gold electrode, which was applied for the determination of trace concentrations of Cu(II). The formation of advanced SAM on the gold electrode was evidenced by electrochemical impedance spectroscopy, atomic force microscopy and contact angle measurements. Electrochemical determination of Cu(II) ions was performed by square wave voltammetry. Some mutual interferences caused by Cd(II), Co(II), Fe(II), Ni(II) and Pb(II) ions were investigated and it was demonstrated how the negative effects of these interfering ions could be eliminated by adjustment of proper parameters of square wave voltammetry.
Facile Synthesis of Pd Nanoparticle Modified Carbon Black for Electroanalysis: Application to the Detection of Hydrazine
Authors: Panchompoo Janjira , Aldous Leigh , Downing Clive , Crossley Alison , Compton Richard G.
Published: May 2011

Carbon black nanoparticles modified with palladium nanoparticles (Pd/CB) were prepared using a facile methodology. Stirring CB in an aqueous solution of palladium chloride was found to result in the spontaneous formation of Pd nanoparticles on the CB surface. The Pd/CB composite demonstrated high electrocatalytic activity towards hydrazine oxidation, with good stability and reproducibility. Three linear dynamic ranges of hydrazine determination were found between 5 µM and 50 mM. The limit of detection (LOD) for hydrazine was found to be 8.8 µM (based on 3σ). The sensitivity of unmodified CB to trace metal impurities present in certain common electrolytes is also noted.
A New Electrochemical Biosensor for Determination of Hydrogen Peroxide in Food Based on Well‐Dispersive Gold Nanoparticles on Graphene Oxide
Authors: Zhang Bing , Cui Yuling , Chen Huafeng , Liu Bingqian , Chen Guonan , Tang Dianping
Published: May 2011

Herein, we describe a new method for the detection of hydrogen peroxide (H2O2) in food by using an electrochemical biosensor. Initially, ultrafine gold nanoparticles dispersed on graphene oxide (AuNP‐GO) were synthesized by the redox reaction between AuCl4− and GO, and thionine‐catalase conjugates were then assembled onto the AuNP‐GO surface on a glassy carbon electrode. With the aid of the AuNP‐GO, the as‐prepared biosensor exhibited good electrocatalytic efficiency toward the reduction of H2O2 in pH 5.8 acetic acid buffer. Under optimal conditions, the dynamic responses of the biosensor toward H2O2 were achieved in the range from 0.1 µM to 2.3 mM, and the detection limit (LOD) was 0.01 µM at 3sB. The Michaelis–Menten constant was measured to be 0.98 mM. In addition, the repeatability, reproducibility, selectivity and stability of the biosensor were investigated and evaluated in detail. Finally, the method was applied for sensing H2O2 in spiked or naturally contaminated samples including sterilized milk, apple juices, watermelon juice, coconut milk, and mango juice, receiving good correspondence with the results from the permanganate titration method. The disposable biosensor could offer a great potential for rapid, cost‐effective and on‐field analysis of H2O2 in foodstuff.
The computation of the eddy along the upper wall in the three‐dimensional flow over a backward‐facing step
Authors: Malamataris N.A. , Löhner R.
Published: May 2011

A three‐dimensional laminar flow over a backward‐facing step is studied as a numerical experiment by solving the steady‐state, isothermal and incompressible Navier–Stokes equations using two different finite element codes. The Reynolds number ranges from 100 to 1050. The expansion ratio is 1:1.94, and the aspect ratio is 1:36.7. The numerical experiment reveals both eddies along the lower and upper walls downstream of the step. Results of computations regarding positions of detachment of the eddy along the upper wall and positions of reattachments of the eddies along both the lower and upper walls are tabulated along with positions and magnitudes of global extrema of shear rate within the eddies. The wall effects are shown by calculating streamlines along planes parallel/normal to the lateral walls of the domain and depicting how the streamlines are distorted close to the walls and how they assume a two‐dimensional configuration in the plane of symmetry. Comparisons are made with available numerical results and laboratory measurements. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation and Characterisation of Novel Composites Based on a Radiation Grafted Membrane for Fuel Cells
Authors: Çilingir Doğan H. D. , Alkan Gürsel S.
Published: May 2011

Novel composites for fuel cells were prepared via two different methods using a radiation grafted membrane, prepared from poly(ethylene‐alt‐tetrafluoroethylene) (ETFE) and styrene, and commercial Nafion®112 as the substrates. The first method was based on chemical polymerisation of pyrrole (Py) on the membrane followed by platinum (Pt) deposition by chemical reduction. The second method was based on direct deposition of Pt on the membrane by several steps of initial composite formation and surface electrodeposition. Polypyrrole (PPy) was coated as a layer only on the surface of the membrane. The thickness of PPy layer, proton conductivity of the composites and Pt loading could be controlled with Py polymerisation time. Moreover, the deposition of Pt on the surface as the granular particles was achieved by the first method while Pt deposition occurred as the aggregates of particles on the surface of the membrane by the second method which yielded wavy and rough surfaces. The first method offered a simple, quick, reproducible and effective procedure, yet some of the Pt particles peeled off from the surface of the composites. The second method required complex, multistep and tedious procedure with a high amount of Pt precursor, while Pt particles were more stable in this case.
Dynamics of Emerging Water Droplet Subjected to Sidewall with Different Wettabilities in a Fuel Cell Cathode Channel
Authors: Zhu X. , Sui P. C. , Djilali N. , Liao Q.
Published: May 2011

On‐site experiments on low temperature fuel cells revealed that water droplets tend to emerge into the gas channel at the corner. This motivates the present investigation on the effects of the location where water emerges from and the wettability of sidewall on the dynamic behaviour of liquid water in gas channel by numerical simulations that employ the volume‐of‐fluid method. A microchannel with a square cross‐section of 0.25 mm in width and a pore of 0.05 mm in diameter is adopted. The simulation results for different pore locations and wettabilities of sidewall show that the behaviour of water droplet only depends on the wettability of bottom wall when it emerges from the centreline without attaching to the sidewall and gains the highest pressure drop. When the emergence location shifts towards the corner, the water droplet unavoidably attaches to the sidewall and thus the wettability of sidewall is found to have significant effects on its dynamics: hydrophobic sidewall results in droplet detachment and fast removal with the highest pressure drop and the minimal water saturation, whereas hydrophilic sidewall leads to a water film and accumulation with the lowest pressure drop and the minimal water coverage on the bottom wall.