bluuebunny/crossref_metadata_2025 huggingface dataset:
As-Needed Treatment with Ranibizumab 0.5 mg in Patients with Neovascular Age-Related Macular Degeneration
Authors: Biarnés Marc , Monés Jordi , Villalbi Joan R. , Arias Lluís
Published: October 2010

Purpose

TO describe the results obtained in patients with neovascular age-related macular degeneration treated with ranibizumab 0.5 mg on an as-needed basis from the start after 1 year of follow-up.

Methods

Retrospective, consecutive interventional case series of patients with all angiographic types of neovascular age-related macular degeneration (mean baseline size, 3.4 disk areas) in a tertiary retinal center (Institut de la Màcula i la Retina; Barcelona, Spain). Main outcome was mean vision change; secondary outcomes were center retinal thickness change, number of injections, adverse events, and independent covariates associated with a good response.

Results

Mean visual acuity change was an increase of 1.3 letters (95% confidence interval −2.7 to +5.3), and difference between angiographic patterns did not reach statistical significance (p=0.30). A decrease in retinal thickness of 44.6 μm was identified (p<0.001), with a median of 3 injections. Absence of baseline arterial hypertension, lower visual acuity, and lesions located outside the fovea were associated with a better response to therapy.

Conclusions

As-needed treatment from the start achieved stabilization of visual acuity and a moderate decrease of retinal thickness with a low number of injections, but did not achieve the same efficacy as regular monthly injections.
Comparing Applanation Tonometry and Rebound Tonometry in Glaucomatous and Ocular Hypertensive Eyes
Authors: Marini Marino , Da Pozzo Stefano , Accardo Agostino , Canziani Tiziana
Published: October 2010

Purpose

TO describe Goldmann applanation tonometer (GAT) and rebound tonometer (RT) agreement in measuring intraocular pressure (IOP) in glaucomatous and ocular hypertensive (OH) eyes and to evaluate central corneal thickness (CCT) influence on RT readings.

Methods

A total of 347 eyes were enrolled and IOP measured between 9 and 11 am. Rebound tonometry was performed first (RT1), followed by 3 consecutive GAT measurements and by a second RT reading (RT2), within a 5-minute span. Mean IOP (±SD) values were compared by means of paired t-test. Agreement between GAT and RT1 (test 1) and RT2 (test 2) was evaluated with Bland-Altman method, whereas a linear function described the relationship between CCT and IOP taken with RT.

Results

Mean IOP (±SD) taken with RT1, GAT, and RT2 was 18.1±4.3, 15.6±3.3, and 16.3±3.9 mmHg, respectively. Readings were within ±3 mmHg in 63.7% and 86.7% of eyes for test 1 and 2, respectively. A significant (p<0.001) proportional bias was noted on both tests (95% limits of agreement: −2.3/7.4 and −3.6/5.0 mmHg for test 1 and 2, respectively). Agreement between instruments decreased for increasing IOP. Rebound tonometry readings increased by 4.6 and 4.1 mmHg for RT1 and RT2, respectively, for each 100–μm CCT increase.

Conclusions

When used first, RT significantly overestimated IOP compared with GAT. Differences became clinically negligible when RT was used immediately after GAT. Repeated applanation tonometry may explain this observation. Agreement between instruments was acceptable for low IOP, but worsened with increasing IOP values. RT is significantly influenced by CCT. Goldmann applanation tonometer and RT should not be used interchangeably.
Trisomy 1q42-qter Associated with Monosomy 6q27-qter: A Case Report
Authors: Tartaglia Edoardo , Mastrantonio Pasquale , Costa Davide , Giugliano Brunella , Porcellini Antonio , Costagliola Ciro
Published: October 2010

Purpose

Partial trisomy 1q42-qter is a rare chromosomal aberration. Most cases arise from de novo unbalanced translocations or from unbalanced inheritance of parental balanced rearrangements.

Methods

Descriptive case report.

Results

A 4-year-old boy had shown an increased neck translucency at the fetal ultrasound examination performed at the 11th week of gestation. Amniocentesis, performed at the 18th week of gestation, did not demonstrate any genetic abnormality. A second fetal ultrasound examination, carried out at the 35th week of gestation, showed congenital clubfeet and hydrocephalus. At birth, clinical examination revealed congenital bilateral ventriculomegaly bilateral congenital equinovarus clubfeet, low-set ears, plagiocephaly micrognathia, hypertelorism, prominent forehead, broad nasal bridge, hypertonic syndrome, and inguinal hernia. Ophthalmologic consultation showed the presence of optic pit in his left eye. Genetic counseling was performed. Chromosome analysis demonstrated a partial trisomy 1 q42.2-qter associated with a partial monosomy 6q27-qter. Moreover, deletions of the distal region on the long arm of chromosome 6 are frequently associated with both ocular abnormalities and several solid tumor types. Moderate mental and psychomotor retardation has occurred.

Conclusions

This case emphasizes the importance of scheduling a screening test for eye diseases and tumor in these patients.
Vitrectomy for Vitreous Opacities and Macular Pucker in Gaucher Disease
Authors: Rapizzi Emilio , Vannozzi Lorenzo , Borgioli Vanni , Giansanti Fabrizio , Murro Vittoria , Sodi Andrea , Menchini Ugo
Published: October 2010

Purpose

TO report significant surgical results in an uncommon ophthalmologic complication of a rare disease.

Methods

Interventional case report.

Results

A 16-year-old girl with type III Gaucher disease experienced visual loss in both eyes. Ophthalmologic examination revealed dense whitish vitreous opacities and macular pucker OU. Visual acuity (VA) OD was 20/63 and OS was 20/25. She underwent 25-gauge vitrectomy with removal of the vitreous core, posterior vitreous cortex, and indocyanine green-stained internal limiting membrane OD. Visual acuity improved, reaching 20/25 1 year after surgery despite the appearance of small preretinal flecks. Visual acuity OS decreased some time later and vitrectomy was performed when VA OS was 20/100. Three years after surgery, BCVA was 20/25 OD and 20/20 OS 1 year after surgery.

Conclusions

We describe a young patient with Gaucher disease with severe bilateral vitreous opacities and macular pucker. After surgery, vitreous opacities partially and progressively recurred, but the overall favorable outcome strongly supports a surgical approach in cases of this kind.
Surgical Reposition of a Dislocated Ex-PRESS Miniature Device
Authors: Vetrugno Michele , Ferreri Paolo , Cardascia Nicola , Sborgia Carlo
Published: October 2010

Purpose

TO present a technique of surgical reposition of the Ex-PRESS miniature glaucoma device when dislocated in corneal limbus.

Methods

A 54-year-old woman diagnosed with glaucoma, with a 3-month history of Ex-PRESS miniature implant, was referred to our department because of progressive intraocular pressure (IOP) rise. Slit-lamp biomicroscopy showed the posterior flange of the implant located in the corneal limbus; IOP was 34 mmHg. Surgical technique consisted of reopening of the conjunctiva and the scleral flap, excision of the corneal tissue covering the flange, and stitching the implant to the sclera with polyprolene suture.

Results

Postoperatively, IOP rapidly reduced to 5 mmHg and was balanced to 10 mmHg in the follow-up.

Conclusions

Corneal dislocation of the Ex-PRESS implant, when associated with ocular hypertension, needs surgical treatment. Before considering a trabeculectomy, it could be valuable to attempt an implant reposition.
Intravitreal Bevacizumab in a Patient with a Macular Star in Malignant Hypertension
Authors: Zucchiatti llaria , lacono Pierluigi , Parodi Mauhzio Battaglia , Cascavilla Maria Lucia , Kontadakis Dimitris Stelios , Bandello Francesco
Published: October 2010

Purpose

TO report a case of retinopathy secondary to malignant hypertension showing a macular star, which responded favorably to a single intravitreal injection of bevacizumab (IVB).

Methods

A 46-year-old man with malignant hypertension showing incomplete macular star in his right eye with best-corrected visual acuity (BCVA) of 20/32 underwent IVB.

Results

Subsequent examinations revealed a progressive resolution of the macular star with functional recovery over the follow-up. In particular, at the 9-month examination BCVA was 20/20, fundus biomicroscopy disclosed resolution of the macular star, and the retinal sensitivity improved remarkably.

Conclusions

Intravitreal injection of bevacizumab can be a useful approach to treat the exudative manifestations of malignant hypertension.
Analysis of the Diurnal Intraocular Pressure Profile Pre and Post Trabeculectomy using 24-Hour Monitoring of Intraocular Pressure
Authors: Ross Adam H. , Jackson Thomas E. , Wertheim Michael S. , Spry Paul G.D. , Sparrow John M. , Diamond Jeremy P.
Published: October 2010

Purpose

TO compare the diurnal intraocular pressure (IOP) profile pre and post trabeculectomy with a control group of medically controlled patients. We compared the change in mean, peak, and diurnal IOP fluctuation.

Methods

This was an observational study of patients at the Bristol Eye Hospital, United Kingdom. All patients underwent initial and subsequent phasing, with surgery between for cases. The unpaired Student t test compared the changes (initial - subsequent) in mean, peak, and fluctuation between cases and controls.

Results

Fifteen eyes underwent trabeculectomy surgery while the control group contained 17 eyes controlled on topical medical treatment. There was a statistically significant reduction in both mean IOP of 3.7 mmHg (p=0.002) and peak IOP of 4.4 mmHg (p=0.025) in the surgical group compared to the medical group. There was no statistically significant change in the IOP fluctuation between the 2 study groups (p=0.296).

Conclusions

There is a significant reduction in mean IOP and peak IOP following trabeculectomy. We showed no statistically significant change in the diurnal fluctuation of IOP following trabeculectomy.
Intravitreal Injection of Bevacizumab Induces Inflammatory Alterations in a Uveitis Experimental Model
Authors: Johnsen-Soriano Siv , Arnal Emma , Sancho-Tello Maria , Muriach María , Almansa Inmaculada , Bosch-Morell Francisco , Navea Amparo , Romero Francisco J.
Published: October 2010

Purpose

Bevacizumab is currently used as an intravitreal agent in the treatment of inflammatory-associated eye diseases. The aim of the current study is to explore the effects of the intravitreal injection of bevacizumab on aqueous humour cytokines and chemokines in an experimental uveitis model.

Methods

Endotoxin-induced uveitis was induced in rats by footpad injections. Bevacizumab was administered by intravitreal injection (75 μg in 3–μL samples) and different chemokine and cytokine proteins were quantified in aqueous humor.

Results

Intravitreal administration of bevacizumab led to a several-fold increase of RANTES, MCP-1, and IFN-γ concentrations in aqueous humor of endotoxin-treated rats.

Conclusions

Given the exacerbating effect of bevacizumab on inflammation agents and considering the increasing use of bevacizumab as an off-label intravitreal agent, care should be taken if an underlying inflammatory disease is present.
An Ultrasound Biomicroscopy Study of Filtering Blebs after Deep Sclerectomy with a New Acrylic Implant
Authors: Cabrejas Laura , Rebolleda Gema , Muñoz-Negrete Francisco José , Losada Diego
Published: October 2010

Purpose

TO identify the clinical and anatomic characteristics of filtering blebs after nonpenetrating deep sclerectomy (NPDS) using ultrasound biomicroscopy, and to evaluate its influence on intraocular pressure (IOP) control.

Methods

We conducted a prospective interventional case series in 18 eyes of 18 patients who had undergone nonpenetrating deep sclerectomy with Esnoper® implant. A complete ophthalmic examination and ultrasound biomicroscopy (UBM) exploration were performed at 1, 3, and 6 months postoperatively.

Results

Intraocular pressure significantly decreased from a mean of 23.5 mmHg (SD 3.5) preoperatively to a mean of 13.1 mmHg (SD 7.6), 13.2 mmHg (SD 4.3), and 13.3 mmHg (SD 3) at 1, 3, and 6 months postoperatively, respectively. At 6 months, lower IOP levels significantly correlated with hyporeflective blebs (r=-0.82, p=0.000), with the presence of hyporeflective suprachoroidal space (r=-0.67, p=0.003) and with the presence of hyporeflective area around the scleral lake (r=-0.55, p=0.02). The presence of these 3 filtration signs together correlated with lower IOP levels compared with the presence of only 1 or 2 (p=0.000, p=0.004, p=0.0005) at 1, 3, and 6 months postoperatively, respectively. A thinner trabeculodescemetic membrane (TDM) was significantly correlated with lower postoperative IOP value at the first postoperative month (r=0.45, p=0.05). Intraocular pressure mean values and UBM characteristics were not significantly different between eyes with single NPDS and eyes following combined NPDS-phacoemulsification. At 6 months, eyes without goniopuncture had lower IOP values (p=0.02), higher bleb (p=0.015), and thinner TDM (p=0.01) than those needing goniopuncture.

Conclusions

Ultrasound biomicroscopy is a useful method to evaluate outflow mechanisms after NPDS and their correlation with postoperative IOP control.
Nerve Fiber Layer and Macular Thinning Measured with Different Imaging Methods during the Course of Acute Optic Neuritis
Authors: Garas Anita , Simó Magdolna , Holló Gábor
Published: October 2010

Purpose

TO compare retinal nerve fiber layer thickness (RNFLT) and inner macula thickness changes measured with Fourier-domain optical coherence tomography (FD-OCT) and scanning laser polarimetry during the course of acute optic neuritis (ON).

Methods

Nine eyes of 7 consecutive patients with multiple sclerosis (MS) were prospectively imaged from the onset of ON for 6 to 12 months. Nine healthy eyes were imaged for 12 to 19 months.

Results

Retinal nerve fiber layer thickness measured with FD-OCT initially increased in all eyes with diffuse optic disc edema. Inner macula thickness and Polarimetric RNFLT decreased already in the acute phase, in all eyes. All parameters stabilized at 2 to 5 months. The relative structural loss was different with the different Methods. Poor image quality with polarimetry occurred in 2 eyes in the acute phase of ON. In the control eyes all parameters were stable.

Conclusions

Change of RNFLT and macular thickness during the course of acute ON in MS strongly depends on the method used for the measurement. Inner macula thickness, measured with FD-OCT, was especially useful for the follow-up, since it was not influenced by initial disc edema and had consistently high image quality.
3D Spectral Domain Optical Coherence Tomography Findings in Choroidal Tumors
Authors: Sayanagi Kaori , Pelayes David E. , Kaiser Peter K. , Singh Arun D.
Published: October 2010

Purpose

TO report the optical coherence tomographic features differentiating choroidal nevus from choroidal melanoma by 3D spectral-domain optical coherence tomography (SD-OCT) and OCT characteristics of other choroidal tumors.

Methods

A total of 67 consecutive eyes with choroidal tumors including choroidal nevus (25 eyes), indeterminate choroidal melanocytic lesion (11 eyes), malignant melanoma (23 eyes), metastasis (4 eyes), hemangioma (2 eyes), and osteoma (2 eyes) were imaged with 3D SD-OCT (OCT-1000; Topcon Inc., Paramus, NJ). The images were analyzed for the presence or absence of SD-OCT findings such as retinal pigment epithelium (RPE)/choriocapillaris reflectivity, RPE irregularity, drusen, sub-RPE fluid, RPE thickness, subretinal deposit, subretinal fluid, intraretinal edema, retinal thickness, and photoreceptor inner and outer segment junction (IS/OS). Visualization of the choroidal tumor and its intrinsic reflectivity OCT features were also assessed.

Results

When compared with nevus, subretinal deposit, subretinal fluid, and intraretinal edema were detected significantly more frequently in the eyes with malignant melanoma (p<0.001). SD-OCT visualization of the tumor was limited only to the anterior aspect. Choroidal nevus, indeterminate lesions, melanoma, and metastatic lesions had variable intrinsic reflectivity pattern. Intrinsic features of hemangioma included choroidal hollowness whereas osteoma demonstrated high intrinsic reflectivity.

Conclusions

SD-OCT provides useful information to observe and document the retinal and RPE changes secondary to choroidal tumors that help differentiate choroidal nevus from malignant melanoma. Improvements in the current OCT systems are needed to better characterize intrinsic features of choroidal tumors.
Chronic Trichuris trichiura Infection Presenting as Ileocecal Valve Swelling Mimicking Malignancy
Authors: Tuan Sharif Sharifah Emilia , Ewe Seng Ch'ng , Mustaffa Nazri , Mohd Shah Nurul Azira , Mohamed Zeehaida
Published: October 2010

A 46-year-old man presented with a history of passing bright red blood per rectum over the last one month. He also had on and off diarrhea with visible mucus in the stool for two months' duration. Further history was unremarkable, and physical examination revealed hemorrhoids which were subsequently banded. A colonoscopy was arranged in view of the prolonged diarrhea whereby an edematous and swollen ileocecal valve was seen. This was shown to be due to Trichuris trichiura infection, confirmed on histopathological examination of biopsies taken from the site. The patient was started on oral albendazole treatment and has been asymptomatic on latest followup. This case illustrates an accidental finding of T. trichuria infection on colonoscopic examination, which was done to investigate the patient's prolonged diarrhea.
A Noval Approach of Altered Cast Technique in Bilateral Partial Maxillectomy Patient with Severely Restricted Mouth Opening
Authors: Tripathi Shuchi , Chand Pooran , Singh Raghuwar D. , Siddharth Ramashankar , Singh Balendra P.
Published: October 2010

Patients with extensive head and neck injuries due to trauma and/or extensive surgical procedures often exhibit a severely limited ability to open the mouth. For the dentist involved in prosthodontic treatment of such patients, restricted mouth opening commonly leads to compromised impressions and prostheses especially in cases where both hard and soft palatal parts have been resected. In prosthodontic treatment, the loaded impression tray is the largest item requiring intraoral placement. During impression procedures, wide mouth opening is required for proper tray insertion and alignment. This is not possible in patients with restricted mouth opening, so a modification of the standard impression procedure is often necessary to accomplish this fundamental step in the fabrication of a successful prosthesis. An alteration in the final impression procedure was made using altered cast technique for fabricating an obturator prosthesis with soft palate extension, and the result obtained was quite satisfactory.
The Role of Albumin in Human Toxicology of Cobalt: Contribution from a Clinical Case
Authors: Catalani Simona , Leone Roberto , Rizzetti Maria Cristina , Padovani Alessandro , Apostoli Pietro
Published: October 2010

The distribution and adverse effects, especially to optic and acoustic nerves, of cobalt released from a hip arthroplasty and its association with albumin were studied. The analysis of cobalt was performed in plasma, whole blood, urine, and cerebrospinal fluid by inductively coupled plasma mass spectrometry (ICP-MS). The fraction of albumin binding the metal was determined by colorimetric assay using dithiothreitol (DTT). In all the biological matrices very high levels of cobalt were measured, but contrary to expected, a higher concentration in whole blood than in plasma was observed. The determination of altered albumin confirmed this hypothesis. This evidence might indicate an alteration in the binding of cobalt to albumin and a consequent increase in the concentration of the diffusible (free) fraction of the metal. This appears an interesting starting point for further investigations for identifying and better understanding cobalt neurotoxicity, apparently not so frequent in occupational medicine and clinical practice.
Acoustic vibrations in free‐standing single‐, bi‐layer nanomembranes and patterned wires
Authors: Bandhu R.S. , Sooryakumar R. , Bussmann K.
Published: November 2010

Brillouin light scattering investigations of acoustic vibrations in freestanding membranes, soft‐hard bi‐layers and patterned wires are described. Studies of longitudinal and transverse standing wave resonances, the wave vector dependence of surface and guided waves as well as their hybridization with flexural and dilational waves are presented. Size effects and the role of reduced dimensions on the acoustic behavior are investigated in soft rectangular polymeric wires on freestanding silicon nitride membranes. The mode frequencies and amplitudes are analyzed in terms of surface Green's functions and the xyz algorithm.
Optical properties of nitride nanostructures
Authors: Cantarero A. , Cros A. , Garro N. , Gómez‐Gómez M.I. , García A. , de Lima M.M. , Daudin B. , Rizzi A. , Denker C. , Malindretos J.
Published: November 2010

In this paper we review some recent results on the optical properties of nitride nanostructures, in particular on GaN quantum dots (QDs) and InN nanocolumns (NCs). First, we will give a brief introduction on the particularities of vibrational modes of wurtzite. The GaN QDs, embedded in AlN, were grown by molecular beam epitaxy (MBE) in the Stransky‐Krastanov mode on c‐ and a‐plane 6H‐SiC. We have studied the optical properties by means of photoluminescence (PL) and performed Raman scattering measurements to analyze the strain relaxation in the dots and the barrier, the effect of the internal electric fields, and the influence of specific growth parameters, like the influence of capping or the spacer on the relaxation of the QDs. A theoretical model, based on continuous elastic theory, were developed to interpret the Raman scattering results. On the other hand, InN NCs have been grown by MBE in the vapor‐liquid‐solid mode using Au as a catalyst. The nanocolumns have different morphology depending on the growth conditions. The optical properties can be correlated to the morphology of the samples and the best growth conditions can be selected. We observe, from the analysis of the Raman data in InN NCs, the existence of two space regions contributing to the scattering: the surface and the inner region. From the inner region, uncoupled phonon modes are clearly observed, showing the high crystal quality and the complete relaxation of the NCs (no strain). The observation of a LO‐phonon‐plasmon couple in the same spectra is a fingerprint of the accumulation layer predicted at the surface of the nanocolumns.
Alkynic fatty acids: ω‐Arylation, methoxycarbonylation to α,β‐unsaturated esters, cyclotrimerization to pyridines and 2‐pyridones
Authors: Augustin Kim E. , Schäfer Hans J.
Published: November 2010

Dehydrogenation of double to triple bonds by bromination/dehydrobromination and triple bond isomerization by the alkyne zipper reaction provide a short and facile access to internal and terminal alkynic fatty acids. Thereby methyl 10‐undecynoate, methyl 9‐octadecynoate, methyl 17‐octadecynoate and derivatives have been prepared from the corresponding alkenic fatty acids. Their conversions are reported: The hydrogen in the terminal alkynic fatty compounds is substituted in a ω‐carboxylation and a palladium(0)‐catalysed ω‐arylation. With carbon monoxide/methanol internal α,β‐unsaturated monoesters and terminal unsaturated diesters are obtained under mild conditions by palladium(II)‐catalysis. Furthermore dimer fatty acids with a pyridine and a 2‐pyridone core are prepared by cyclotrimerizations of alkynic fatty compounds with alkylnitriles and N‐phenylisocyanate.
Synthesis and properties of highly branched Jatropha curcas L. oil derivatives
Authors: Daniel Louis , Ardiyanti Agnes R. , Schuur Boelo , Manurung Robert , Broekhuis Antonius A. , Heeres Hero J.
Published: November 2010

The synthesis and properties of a number of novel branched Jatropha curcas L. oil (JO) derivatives containing vicinal di‐ester units in the fatty acid chains are reported. Both the length (acetyl vs. hexanoyl) and the stereochemistry of the vicinal di‐ester units (cis vs. trans) were varied. The compounds were prepared by two different synthetic approaches using catalytic chemistry. The first approach involves epoxidation of JO using a Sharpless epoxidation with methyltrioxorhenium as the catalyst to give epoxidized JO (1), followed by an esterification reaction with the corresponding anhydrides using ammonium‐12‐molybdophosphate (AMP) as catalyst to give trans‐di‐esters of JO (4a, 4b). The second approach is based on the dihydroxylation of JO using either the Prilezhaev method, resulting in trans‐diols of JO (2), or the Upjohn method using osmium tetroxide as catalyst to give cis‐diols of JO (3). In subsequent steps, the diols were esterified with acetic‐ or hexanoic anhydride using dimethylaminopyridine as catalyst to produce the corresponding cis‐ and trans‐di‐esters of JO (5a, 5b, 6). The best cold flow properties (lowest pour‐ and cloud point, crystallization and melting temperature) were obtained for JO with hexanoyl branches in a trans orientation (5b, pour point of −14°C, melting point of −5°C, and crystallization temperature of −25°C) and these values are considerably better than for the JO source.

Practical applications: Jatropha curcas L. oil (JO) is a toxic oil with potential applications not only as a green biodiesel but also as a feedstock for the oleochemical industry. The toxicity prohibits the use in food products but does not interfere with technical applications. Here we report studies on the synthesis of interesting JO derivatives (epoxidized, dihydroxylated, and branched compounds) that could be useful starting materials for a range of derivatives with a broad application perspective. The branched JO derivatives with vicinal di‐ester units in the fatty acid chains have cold flow properties (pour‐ and cloud point, melting point and crystallization temperature) considerably better than the original JO. In addition, the oxidative stability was also improved significantly. These novel branched JO derivatives may have interesting applications as cold‐flow improvers for biodiesel or as biolubricants.
Batch‐mode microfluidic radiosynthesis of N‐succinimidyl‐4‐[18F]fluorobenzoate for protein labelling
Authors: Bejot Romain , Elizarov Arkadij M. , Ball Ed , Zhang Jianzhong , Miraghaie Reza , Kolb Hartmuth C. , Gouverneur Véronique
Published: November 2010

The batch microfluidic technology is a promising system for sequential chemical steps combining the advantages of micro‐scale reactions, while addressing some shortcomings of flow‐through systems. We report herein the convenient three‐step, one‐pot synthesis and purification of [18F]SFB. [18F]SFB is a radiolabelling agent that can be used to label sensitive biomolecules, which are not accessible by direct nucleophilic 18F‐fluorination.

Five sequential steps were performed with a batch microfluidic device to obtain the short‐lived positron‐emitter‐labelled molecule. Aqueous [18F]fluoride was concentrated and further eluted to a microreactor for evaporation. Nucleophilic 18F‐fluorination of the precursor was carried out at high temperature, prior to hydrolysis and subsequent activation of the 4‐[18F]fluorobenzoyl group. Purification on miniaturized solid‐phase finally afforded [18F]SFB in 25 min and 55±6% yield (not decay‐corrected) and >98% radiochemical purity. In this study, microfluidic prepared [18F]SFB could be further successfully used for labelling the epidermal growth factor protein.

These results illustrate how microfluidic batch devices are advantageous for producing radiotracers for molecular imaging, e.g. Positron emission tomography. The technology offers many benefits such as the possibility to use much smaller quantities of starting material, reduced reaction time combined with improved efficiency, and easier purification. Copyright © 2010 John Wiley & Sons, Ltd.
Scale growth process at 1473 K on unmodified and yttrium‐ or chromium‐implanted β‐NiAl
Authors: Jedlinski J. , Grosseau‐Poussard J.‐L. , Bonnet G. , Kowalski K. , Bernasik A. , Smola G. , Nocun M.
Published: November 2010

Early oxidation of unmodified and yttrium‐implanted or chromium‐implanted β‐NiAl intermetallic compound at 1473 K was studied using a combination of two‐stage‐oxidation exposure with 18O2 as a tracer, SIMS elemental distribution analysis (depth profiling and imaging modes) and photoluminescence spectroscopy analysis of the scale phase composition.

It was found that phase transformation of transient aluminium oxides, represented by θ‐ Al2O3 into stable and protective α‐Al2O3 occurs locally and is affected by implanted additions: Yttrium retarded while chromium appeared to accelerate it. Typical patch‐ and/or web‐like scale morphology of the growing scales was observed.
Teacher career paths, teacher quality, and persistence in the classroom: Are public schools keeping their best?
Authors: Goldhaber Dan , Gross Betheny , Player Daniel
Published: November 2010

In this paper we examine the mobility of early‐career teachers of varying quality, measured using value‐added estimates of teacher performance. Unlike previous studies that have examined these issues, we focus on the variation in these effects across the effectiveness distribution. We find that, on average, more effective teachers tend to stay in their initial schools and in the teaching profession. But there also appears to be heterogeneity in mobility behavior across the performance distribution and evidence that teacher mobility is affected by student demographics and achievement levels. © 2010 by the Association for Public Policy Analysis and Management.
A novel ion‐imprinted hydrogel for recognition of potassium ions with rapid response
Authors: Wu Han‐Guang , Ju Xiao‐Jie , Xie Rui , Liu Ying‐Mei , Deng Jin‐Gen , Niu Catherine Hui , Chu Liang‐Yin
Published: November 2010

A novel ion‐imprinted strategy is developed for synthesizing responsive hydrogels with rapid response to potassium ions. With potassium ions as templates, ion‐imprinted poly(N‐isopropylacrylamide‐co‐benzo‐15‐crown‐5‐acrylamide) (P(NIPAM‐co‐B15C5Am)) hydrogels are synthesized with 15‐crown‐5 crown ethers mounted on the polymer networks in pairs; therefore, it is very easy and fast for the crown ethers to capture potassium ions again by their Venus flytrap action and form stable 2:1 “host–guest” complexes with potassium ions in the ion‐recognition process. As a result, the response rate of the ion‐imprinted hydrogels to potassium ions is significantly faster than that of normal P(NIPAM‐co‐B15C5Am) hydrogels in which 15‐crown‐5 crown ethers are randomly pendent on the polymeric networks. Copyright © 2010 John Wiley & Sons, Ltd.
Microwave‐assisted acid extraction methodology for trace elements determination in mastic gum of Pistacia lentiscus using inductively coupled plasma atomic emission spectrometry
Authors: Zachariadis George A. , Spanou Eleni A.
Published: November 2010

Introduction – To ensure food safety, accurate knowledge of the levels of several trace elements is necessary. This is also true for natural products of plants and resins used for human consumption or therapeutic treatment, like the mastic gum of Pistacia lentiscus. The rapid analysis of gum and resin matrices is a challenge because there are problems with the decomposition of such complicated matrices.

Objective – To develop an efficient multielemental analytical method for the determination of trace elements and to compare different procedures for analyte extraction when microwave‐assisted digestion is applied.

Methodology – The inductively coupled plasma atomic emission spectrometric (ICP‐AES) technique was applied and the optimum ICP conditions like radiofrequency power, argon flow rate and nebuliser sample uptake flowrate were found. The microwave‐assisted procedure was compared with that with conventional heating. Since mastic and resinous materials are difficult for dissolution and extraction of trace element, influential acid mixtures containing hydrofluoric acid proved to be capable of quantitative extraction of the analytes.

Results – The digestion of mastic resin or similar matrices is significantly facilitated by using microwave radiation instead of conventional heating since the obtained recovery for several analytes is much higher. It was proved that the acid mixture of HCl–HNO3–HF was the most efficient for complete sample digestion and recovery of the analytes.

Conclusions The performance characteristics of the developed method were evaluated against certified reference material and the method was proved reliable and applicable to the analysis of mastic gum and possibly to similar resinous matrices. Copyright © 2010 John Wiley & Sons, Ltd.
Simultaneous determination of naphthalene and anthraquinone derivatives in Rumex nepalensis Spreng. Roots by HPLC: comparison of different extraction methods and validation
Authors: Gautam Raju , Srivastava Amit , Jachak Sanjay M.
Published: November 2010

Introduction – Rumex nepalensis contains mainly anthraquinone and naphthalene derivatives. Although HPLC methods have been reported for the analysis of anthraquinones, neither a phytochemical analysis of Rumex species nor the simultaneous determination of anthraquinone and naphthalene derivatives in other samples has been reported so far.

Objective – To develop and validate a HPLC method for the simultaneous determination of anthraquinone and naphthalene derivatives in R. nepalensis roots.

Methodology – Anthraquinones and naphthalenes were extracted from R. nepalensis roots by three methods (reflux, ultrasonication and pressurized liquid extraction) using methanol. Separation was achieved on an RP C18 column with a gradient mobile phase consisting of 0.05% orthophosphoric acid in water (solvent A) and methanol (solvent B) using a UV detector (254 nm).

Results – Small differences were observed in the contents of anthraquinone and naphthalene derivatives extracted by the three methods. Chrysophanol‐8‐O‐β‐D‐glucopyranoside and nepodin were detected as major constituents. The method showed a good linearity (r2 > 0.9992), high precision (RSD < 5%) and a good recovery (97–105%) of the compounds. The lowest detection limit was found to be 0.97 ng and the method was found to be robust.

Conclusion – Reflux and ultrasonication were found to be the best suited methods for the extraction of glycosides and aglycones, respectively. The developed and validated HPLC method is simple, precise and accurate; and can hence be recommended as the method of choice for the analysis of anthraquinones and naphthalenes in R. nepalensis and other Rumex species for both quality control as well as routine analytical purposes. Copyright © 2010 John Wiley & Sons, Ltd.
Modelling of Pressure Distribution inside the SEN in a Stopper‐rod controlled System
Authors: Savolainen J. , Rousu A. , Fabritius T. , Mattila O. , Sulasalmi P.
Published: November 2010

Shrouding tubes and submerged entry nozzles (SEN) are mainly used on steel transfer between process units of continuous casters. Molten steel flow in the SEN or shrouding tube causes a pressure drop which creates possibilities for air aspiration through refractory material. The objective of this research was to model the pressure distribution in the SEN of a continuous caster using a full scale water model. Effects of casting speed, SEN immersion depth and liquid level of tundish on the pressures at the SEN wall and centre were defined. The experiments proved that SEN immersion depth had the most remarkable effect on the pressure inside the SEN. However experiments did not show a significant effect of casting speed and tundish liquid level on the pressure inside the SEN. This research presents a simplified model for pressure distribution in SEN. The presented model agrees well with measurements at the SEN wall.
Three‐dimensional Simulation of Thermosolutal Convection and Macrosegregation in Steel Ingots
Authors: Li W. S. , Shen H. F. , Liu B. C.
Published: November 2010

Thermosolutal convection and macrosegregation formation during the solidification of steel ingots are numerically simulated in three dimensions. The simulation is based on a fully coupled model for mass, momentum, energy, and species conservation equations. The interdendritic flow in the mushy zone is governed by Darcy's law, and the permeability term is discretized using an interpolated liquid fraction method. The numerical results for a benchmark test of macrosegregation in a Pb‐Sn alloy are compared with experimental data taken from the literature. The present model is applied to simulate the solidification of industrial steel ingots. Preliminary predictions are obtained, including the positive segregation in the hot top, and the conically shaped negative segregation zone at the bottom of the ingot. The predicted variation of the segregation ratio in carbon along the vertical centreline of an ingot is compared with measurements, and generally good agreement is observed. Future attention should be paid to the precision of prediction by considering complex solidification issues, such as the sedimentation of free equiaxed grains and the formation of shrinkage cavity.
Effects of TiN and AlN Nanoparticles in Hot Deformation of Austenite in Steels
Authors: Medina S.F. , Gómez M. , Valles P.
Published: November 2010

Recrystallisation kinetics of two low‐carbon steels, of which one with Ti and the other with Al as precipitate‐forming elements was studied by means of hot torsion tests. The mean size of TiN and AlN particles that precipitate during hot deformation was analysed by transmission electron microscopy (TEM). These results, along with the determination of the activation energy, the precipitated volume fraction and the diffusion coefficients of Ti, Al and N in austenite explain the ineffectiveness of these particles to inhibit the static recrystallisation.
Numerical Cooling Strategy Design for Hot Rolled Dual Phase Steel
Authors: Suwanpinij P. , Togobytska N. , Prahl U. , Weiss W. , Hömberg D. , Bleck W.
Published: November 2010

In this article, a Mo‐Mn dual phase steel and its process parameters in hot rolling are discussed. The process window was derived by combining the experimental work in a hot deformation dilatometer and numerical calculation of the process parameters using rate law models for ferrite and martensite transformation. The ferrite formation model is based on the Leblond and Devaux approach while martensite formation is based on the Koistinen‐Marburger (K‐M) formula. The carbon enrichment during ferrite formation is taken into account for the following martensite formation. After completing the parameter identification for the rate law model, the evolution of phases in this steel can be addressed. Particularly, the simulations allow the prediction of preferable degree of retained strain and holding temperature on the run out table (ROT) for the required ferrite fraction.
Computational Modelling of Oxide Surface Tensions in Secondary Metallurgy and Continuous Casting
Authors: Heikkinen E.‐P. , Riipi J. , Fabritius T. , Pajarre R. , Koukkari P.
Published: November 2010

Two computational models were used to estimate the surface tensions of oxide systems containing SiO2, CaO, Na2O and Al2O3 as a function of temperature and composition. The compositions of the oxide melts were chosen to correspond to those of ladle slags in secondary metallurgy and to casting powders in continuous casting of steel. The first model uses Butler's equation to calculate the surface tensions of the multicomponent melts and is based on Tanaka et al.'s consideration of the ionic radii of the components as well as surface tensions and molar volumes of pure components. In the second model the same ionic radii dependent contribution is applied as activity coefficients to a constrained free energy model where the surface layer is considered as a separate phase in the system. In the model, the constrained interfacial area is analogous with a component mass balance in a traditional computation of a multiphase chemical equilibrium and surface energy with the corresponding chemical potential. Based on the results it is concluded that the effect of temperature on the surface tensions of the considered oxide melts is insignificant when compared to the effect of chemical composition. According to the validation the results agree well with published surface tension data. The multi‐component surface tension approach provides a practical method for evaluation of e.g. functioning of various casting powders in industrial steel casting practice.
Calculation of Oxygen and Sulfur Average Velocity on the Iron Surface: A Two‐dimensional Gas Model Study
Authors: Cao W. , Delin A. , Seetharaman S.
Published: November 2010

In the present work, a two‐dimensional (2D) gas model is derived and used to simulate the average velocity of individual atoms of the surface active elements oxygen and sulfur on the Fe(100) surface. The average velocity of oxygen and sulfur atoms was found to be related to the vibration frequencies and minimal energy barrier. The calculated results are based on data from density functional calculations combined with thermodynamics and statistical physics. The calculated average velocity of oxygen on the Fe (100) is lower than that of sulphur. This is because of the stronger interaction between oxygen and the first iron layer. We conclude that our simple 2D gas model may be useful for simulating and understanding the complex interfacial phenomena in the steelmaking refining process from an atomic point of view.
The Influence of Carbonaceous Material on the Melting Behaviour of Mould Powder
Authors: Singh D. , Bhardwaj P. , Yang Y. D. , McLean A. , Hasegawa M. , Iwase M.
Published: November 2010

The melting behaviour of mould powder during continuous casting is an important consideration with respect to caster performance, production rate and steel quality. In this experimental study the effect of different carbonaceous materials on the melting characteristics of mould powders was evaluated. Using X‐ray diffraction, different types of carbon were quantitatively characterized in terms of their internal structure and reactivity experiments were conducted to investigate potential relationships between the structural morphology of carbons and their reactivity. High temperature microscopy and drip test experiments were then used to investigate the melting behaviour of mould powders containing different carbonaceous materials. From the results obtained, correlations were established between the structural factors, chemical reactivity and melting behaviour.
A Hybrid Model of Steel Refining in The Ladle Furnace
Authors: Kargul T. , Falkus J.
Published: November 2010

The paper presents the concept of a new mathematical model, which has been used for the simulation of the ladle furnace steel refining process. The structure of the model contains a mathematical description of the steel stirring processes caused by the injection of argon and a thermodynamic description of the reactions occurring at the metal‐slag interface. Both models have been combined into a single hybrid model, using the SimuSage package. The hybrid model has served as the basis for the creation of a proprietary simulation tool, which has been used to assess the effectiveness of the metal bath desulfurization process in the ladle furnace. The applied mathematical description of the processes occurring in the ladle furnace enables the process simulation to be carried out in real time. The constructed model has been verified in industrial conditions for a ladle furnace of 140 t capacity.
Thirty‐Day Morbidity and Mortality of the Laparoscopic Ileal Interposition Associated with Sleeve Gastrectomy for the Treatment of Type 2 Diabetic Patients with BMI <35: An Analysis of 454 Consecutive Patients
Authors: DePaula Aureo L. , Stival Alessandro , Halpern Alfredo , Vencio Sergio
Published: November 2010

Background

The objective of this study was to evaluate the early results of the laparoscopic interposition of a segment of ileum associated with a sleeve gastrectomy (LII‐SG) in order to treat patients with type 2 diabetes mellitus (T2DM) and BMI <35. Data regarding morbidly obese diabetic patients subjected to surgery has consistently been validated. To date, there is scarce information about morbidity and mortality related to the surgical treatment of a “true” typical diabetic population with BMI <35.

Methods

The procedures were performed in 454 patients (322 male, 132 female). Mean age was 53.6 ± 8 years (range = 27–75). Mean BMI was 29.7 ± 3.6 kg/m2 (range = 19–34.8). All patients had the diagnosis of T2DM for at least 3 years. Insulin therapy was used by 45.6% of patients. Mean duration of T2DM was 10.8 ± 5.9 years (range = 3–35). Mean hemoglobin A1c was 8.8 ± 1.9%. Dyslipidemia was observed in 78.4%, hypertension in 64.8%, nephropathy in 28.6%, retinopathy in 32.6%, neuropathy in 34.6%, and coronary heart disease in 13%.

Results

There was no conversion to open surgery. All patients were evaluated postoperatively. Mortality was 0.4%. There were 29 major complications (6.4%) in 22 patients (4.8%) and 51 minor complications (11.2%). Reoperations were performed on 8 patients (1.7%). Twenty patients (4.4%) were readmitted to the hospital. Mean postoperative BMI was 25.8 ± 3.5 kg/m2. Mean fasting plasma glucose decreased from 198 ± 69 to 128 ± 67 mg/dl and mean postprandial plasma glucose decreased from 262 ± 101 to 136 ± 43 mg/dl.

Conclusions

The laparoscopic ileal interposition associated with a sleeve gastrectomy was considered a safe operation with low rates of morbidity and mortality in a diabetic population with BMI < 35. An early control of postprandial glycemia was observed.
Clinical and Histopathological Characteristics of Hyperparathyroidism‐induced Hypercalcemic Crisis
Authors: Starker Lee F. , Björklund Peyman , Theoharis Constantine , Long William D. , Carling Tobias , Udelsman Robert
Published: November 2010

Background

The clinical and pathological characteristics of hyperparathyroidism‐induced hypercalcemic crisis (HIHC) are incompletely described. The present study was designed to elucidate the nature and effects of HIHC in patients undergoing parathyroidectomy in our unit.

Methods

A prospective database of 1,754 consecutive patients with primary hyperparathyroidism (PHPT) who underwent parathyroidectomy from 1991–2009 identified 67 (41 women) patients presenting with HIHC. Hyperparathyroidism‐induced hypercalcemic crisis was defined as symptoms and signs of acute calcium intoxication with a concomitant total albumin corrected calcium level >13.5 mg/dl (range: 8.8–10.2 mg/dl). Clinical and pathological characteristics were evaluated. Data are expressed as mean ± SEM.

Results

Mean age at presentation was 56.7 ± 2.2 years. Twenty‐four of 67 patients (35%) required preoperative in‐hospital management. Of these, all were treated with saline resuscitation, whereas 20/24 (83%) were treated pharmacologically. Neurocognitive derangements and nephrolithiasis with associated hematuria were the most common presenting symptoms and signs. Preoperative serum calcium and the intact parathyroid hormone level (PTH) were 14.0 ± 0.19 mg/dl and 393 ± 43 pg/ml (reference range: 12–65 pg/ml), respectively. Minimally invasive parathyroidectomy under local cervical block was performed in 28/67 patients (42%); the remainder underwent standard cervical exploration. All patients had postoperative normalization of serum calcium and intact PTH. Hyperparathyroidism‐induced hypercalcemic crisis was due to parathyroid carcinoma in 3/67 patients (4.5%), whereas the remainder of patients displayed a single parathyroid adenoma (n = 57) or multiglandular hyperplasia (n = 7). Histopathological evaluation from HIHC patients revealed a chief cell microcystic pattern in 15/21 (71.4%) of examined parathyroid tumors.

Conclusions

Hyperparathyroidism‐induced hypercalcemic crisis is most commonly due to a single parathyroid adenoma, often associated with a microcystic histopathological pattern. The condition is optimally managed with saline hydration and urgent parathyroidectomy.