bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermorheological Simplicity and Fragility of Azobenzene Nematogenic Side‐Chain Polymers
Authors: Andreozzi L. , Autiero C. , Faetti M. , Galli G. , Giordano M. , Zulli F.
Published: March 2008

Summary: The linear viscoelastic response of polymers from a nematogenic azobenzene methacrylate and its copolymers with nonmesogenic methyl methacrylate was studied. These samples showed thermorheological simplicity in the whole investigated temperature range, even across the nematic‐isotropic transition. The temperature dependence of the zero‐shear viscosity confirmed a thermorheologically simple behavior, which allowed interpretation of η(T) in the framework of free‐volume theory. The way the relaxation mechanisms tended to their asymptotic behavior was described in terms of fragility parameters, and a comparison of fragilities of the samples was carried out. The analysis of fragility and temperature dependence of viscosity provided better understanding of the way the architecture of these nematic polymers influences free‐volume quantities and determines relaxation mechanisms.
Thermal Properties of Poly(L‐lactide)/Calcium Carbonate Nanocomposites
Authors: Andričić Branka , Kovačić Tonka , Perinović Sanja , Grgić Adela
Published: March 2008

Summary: Thermal properties of nanocomposites prepared of poly(L‐lactide) (PLLA) and CaCO3 applying differential scanning (DSC) calorimetry and thermogravimetry (TG) were studied. Nanocomposites were prepared by extrusion process at 170 °C. DSC measurements show that CaCO3 has no influence on glass transition and melting point of PLLA but lowers its cold crystallization temperature. There is no difference in glass transition temperature of PLLA before and after extrusion. High temperature thermal stability of the PLLA in the composites is poorer than neat PLLA. Kinetic parameters also indicate greater reactivity of the system upon CaCO3 addition.
Synchronous reconstruction of the floor of mouth and chin with a single skin island fibular free flap
Authors: Wein Richard O. , Lewis Andrea F.
Published: March 2008

Objectives: The goal this presentation is to: 1) Review the reconstructive options for anterior mandible through‐and‐through composite defects and 2) Instruct the audience in the application of the double‐skin paddle fibular flap in selected patients. Methods: Case presentation with review of the literature. Results: A 70‐year old male with an anterior floor of mouth squamous cell carcinoma underwent composite resection that included resection of a 5‐cm ovoid component of overlying chin skin. The defect was reconstructed with a fibular osteocutaneous flap with a double skin paddle technique. Conclusions: Several reconstructive options have been described in the literature for extended oral cavity defects including the use of multiple free flaps, combinations of regional and distant flaps, and sequential reconstruction. This case report reviews the use of a single flap reconstruction of these defects for selected patients. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Benefits of interval‐training on fatigue and functional capacities in Charcot–Marie–Tooth disease
Authors: El Mhandi Lhassan , Millet Guillaume Y. , Calmels Paul , Richard Antoine , Oullion Roger , Gautheron Vincent , Féasson Léonard
Published: March 2008

Exercise intolerance and undue fatigue are common complaints in patients with Charcot–Marie–Tooth (CMT) disease. Reduced physical ability is due directly to the disease, but it is also due to physical deconditioning. The aim of this study was to test whether 24 weeks of interval‐training exercise (ITE) cycling can significantly improve physiological, neuromuscular, and functional capacities and alleviate fatigue in CMT patients. Eight CMT patients (4 CMT1A and 4 CMT2) participated in ITE for 3 nonconsecutive days per week. Cardiovascular fitness, muscle strength, fatigue resistance, and functional capacities were measured before and after 12 weeks of supervised hospital training and again after another 12 weeks of unsupervised home training. Training was well tolerated. There were significant improvements in cardiorespiratory capacities, isokinetic concentric strength, and functional ability measurements. All patients experienced an improvement in their self‐reported visual analogic scale for fatigue and pain during training. However, there was no significant change in their isometric force production and indices of fatigue resistance after training. Although the improvement in exercise tolerance may be due in part to reversal of the deconditioning effect of their related sedentary lifestyle, this clinical trial suggests that ITE can benefit CMT patients especially in their functional performance and subjective perception of pain and fatigue. Moreover, the improvement observed at the end of the first supervised period ITE was maintained after the second unsupervised home period, although there was no further improvement in performance and tolerance. Muscle Nerve, 2008
Sporadic bulbospinal muscle atrophy with facial‐onset sensory neuropathy
Authors: Isoardo Gianluca , Troni Walter
Published: March 2008

We report a case of idiopathic severe facial‐onset sensorimotor neuropathy with no evidence of Kennedy's disease, familial amyotrophic lateral sclerosis, amyloidosis, Tangier disease, sarcoidosis, chronic basilar meningitis, or Sjögren's syndrome. Clinical and neurophysiological features of this patient resemble those of four recently reported patients who were affected with facial‐onset sensorimotor neuropathy (FOSMN), a probably novel disease. The present report provides information about a further patient with FOSMN in order to better characterize the clinical and laboratory features of this disease. Muscle Nerve, 2008
Tissue Doppler imaging for detecting onset of muscle activity
Authors: Pulkovski Natascha , Schenk Peter , Maffiuletti Nicola A. , Mannion Anne F.
Published: March 2008

Tissue Doppler imaging (TDI) is typically used to image and quantify tissue motion. We investigated whether this method would serve as a viable alternative to surface electromyography (EMG) in providing a reliable and valid measure of the onset of muscle activity. Ten healthy subjects performed maximal knee extension exercises at 0°/s (isometric), 60°/s, 120°/s, 180°/s, and 240°/s (5 times each, on each side), using an isokinetic dynamometer. Simultaneous EMG and TDI velocity (superimposed on motion‐mode ultrasound cine‐loops) recordings were made from vastus lateralis. All tests were repeated 1 week later. There was a good correlation between the onset times determined with TDI velocity and EMG: r = 0.78 (day 1), and r = 0.80 (day 2) (each P < 0.001). The mean difference (and SD) in muscle onset time between the two methods (TDI minus EMG) was −20.3 ± 31.0 ms (day 1) and −17.4 ± 27.2 ms (day 2). TDI represents a reliable and valid measure of detecting onset of muscle activity. The mean difference between EMG and TDI onset times (approximately 20 ms) is likely explained by electromechanical delay. TDI represents a viable method for measuring the onset of muscle activity; it may offer a non‐invasive alternative to fine‐wire EMG for use with small or deep muscles. Muscle Nerve, 2008
Abnormal crosstalk between pancreatic acini and macrophages during the clearance of apoptotic cells in chronic pancreatitis
Authors: Bartel M , Hänsch GM , Giese T , Penzel R , Ceyhan GO , Ketterer K , von Knebel‐Döberitz M , Friess HM , Giese NA
Published: March 2008

In chronic pancreatitis (CP), both the progressive loss of acinar parenchyma and aggressive fibro‐inflammatory reactions ultimately lead to irreversible organ destruction. Dying cells are normally removed by macrophages and elimination is associated with anti‐inflammatory cytokine switch. We investigated whether defective clearance of damaged acini by macrophages such as compromised phagocytosis or altered cytokine reaction occurs in CP and thus represents a causative link between acinar loss and fibro‐inflammation. In a checkerboard‐like co‐culture system, we assessed normal and CP macrophages for their phagocytic and cytokine responses to dying pancreatic acinar cells of normal or CP origin by FACS, confocal microscopy, QRT‐PCR, and ELISA. In CP, phagocytosis of apoptotic acini by macrophages was not impaired; however, the associated cytokine responses were gradually perturbed. Most interestingly, only normal acini suppressed TGFβ1 expression and accumulation specifically in normal macrophage cultures, while CP acini lost this ability. Both types of apoptotic acini induced pro‐inflammatory cytokine bursts of varying strength in both types of macrophages; however, the most significant difference (more than 50‐fold higher expression of IL‐1β, IL‐6, and IL‐8) was evident between CP/CP and normal/normal combinations, indicating that acinar and macrophage alterations synergistically lead to the ultimate CP‐specific bias. In combination with in situ data comparing circulating inflammatory cells to pancreatic resident ones, our results indicate that cytokine expression in inflammatory cells undergoes spatiotemporal modulation, most likely through a successive interplay of acinar, stromal, and circulating factors. Thus, clearance of injured pancreatic acini by macrophages is associated with a unique cytokine reaction which may constitute a basis for progression of SAPE (sentinel acute pancreatitis event) to the irreversible fibro‐inflammation in CP. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Factors influencing the association between active ingredient and adjuvant in the leaf deposit of adjuvant‐containing suspoemulsion formulations
Authors: Faers Malcolm A , Pontzen Rolf
Published: March 2008

BACKGROUND: For an oil adjuvant to enhance uptake of a particulate active ingredient (AI), it is hypothesised that closer association between the two should result in higher uptake. Accordingly, factors important for the spray deposit size on grapevine leaves have been investigated for a series of model suspoemulsion formulations containing colloidal crystalline AI or fluorescent pigment particles and an emulsion of an oil adjuvant with different degrees of wetting and different spray volumes.

RESULTS: Low spray volumes (<100 L ha−1) produced small deposits with high particle–adjuvant association. Complementary uptake studies showed increased uptake with decreasing deposit size, in agreement with the above hypothesis. Higher spray volumes produced larger deposits that consisted of annuli formed by pinning of the contact line by particles. Low surfactant concentrations favoured particles in the annulus and adjuvant separated in the centre. Intermediate surfactant concentrations produced annuli containing both particles and adjuvant, while with high surfactant concentrations the deposits were large with few annuli.

CONCLUSIONS: Small deposits result in high AI–adjuvant association. With larger deposits, annulus structures allow for enhanced AI–adjuvant association (5–20 times greater). The formation of annuli appears to be important in enhancing the biodelivery of particulate AIs in adjuvant‐containing suspoemulsion formulations at intermediate spray volumes. Copyright © 2008 Society of Chemical Industry
An innovative molybdenum column liner for oxygen and hydrogen stable isotope analysis by pyrolysis
Authors: Stuart‐Williams Hilary , Wong S. Chin , Farquhar Graham D. , Keitel Claudia , Clayton Stephen
Published: March 2008

The most widely used method for pyrolysing samples for hydrogen or oxygen isotopic analysis involves heating them to greater than 1300°C in a helium stream passed through a glassy carbon tube in an alumina casing. There are a number of difficulties with this. Glassy carbon tubes are expensive and interaction between the carbon tube and the outer casing produces unwanted carbon monoxide by reduction of the alumina at high temperatures. The latter effect is overwhelming if temperatures of 1400°C or greater are used for pyrolysis. We experimented with lining alumina casings with pure molybdenum sheet. It is relatively cheap, conforms well to the interior of the reactor tube (to avoid carrier and sample bypassing of the carbon pack), resists high temperatures and neither oxidises excessively nor absorbs the gases. The main disadvantages are that silver sample cups must be used and that the molybdenum degrades over time by formation of the carbide. We can maintain sharp peaks, high precision and good accuracy over more than 700 solid samples for both hydrogen and oxygen. The reactors last longer for water injections. The molybdenum in the columns does not contribute greatly to memory effects. The precision of analysis is dependent on other factors as well as the pyrolysis column, but for oxygen we typically achieve approximately <0.2‰ (sucrose), <0.25‰ (water) and <0.25‰ (leaf), sometimes using only a linear correction of drift, after dividing the run into 1 to 3 segments. Copyright © 2008 John Wiley & Sons, Ltd.
Detergent‐free biotin switch combined with liquid chromatography/tandem mass spectrometry in the analysis of S‐nitrosylated proteins
Authors: Han Peiwei , Chen Chang
Published: March 2008

High‐throughput proteomic analysis based on a biotin switch combined with liquid chromatography/tandem mass spectrometry (LC/MS/MS) enables simultaneous identification of S‐nitrosylated sites and their cognate proteins in complex biological mixtures, which is a great help in elucidating the functions and mechanisms of this redox‐based post‐translational modification. However, detergents such as sodium dodecyl sulfate (SDS) and Triton X‐100 adopted in these systems, which are hard to fully remove in the subsequent MS‐based analyses, can suppress the peptide signals and influence the SNO‐Cys site identification and the reproducibility of the experiments. Here we developed a detergent‐free biotin‐switch method, which applied urea to replace detergents, and successfully combined it with LC/MS/MS in the analysis of S‐nitrosylated proteins. With this approach, 44 SNO‐Cys sites were specified on 35 distinct proteins in S‐nitrosoglutathione (GSNO)‐treated HeLa cell extracts of proteins with good reproducibility. The LC/MS performance was greatly improved as analyzed with Pep3D and the amount of samples for analysis reduced from 40 mg used in the literature to 3–5 mg. For S‐nitrosylated targets detected both in the control sample and in the GSNO‐treated sample, extracted ion chromatography (XIC) was employed to estimate the quantitative change of S‐nitrosylation (S‐nitrosation), which facilitates the judgment on 'accept or reject' of the identified targets. Copyright © 2008 John Wiley & Sons, Ltd.
Hydrolysis of thioesters in an ion trap
Authors: Cullen Matthew , Miles Deborah , Rothwell Arlene , Bonham Connie , Wood Karl V. , Cushman Mark
Published: March 2008

The alkenyldiarylmethanes are a class of non‐nucleoside reverse transcriptase inhibitors that are currently being developed as potential antivirals for the treatment of HIV infection and AIDS. As part of our continuing investigations on the alkenyldiarylmethanes, a series of thioester analogues were prepared in an effort to improve upon the metabolic stability of the parent lead compound. Hydrolysis of the thioester moieties was consistently observed during ion trap electrospray ionization (ESI) mass spectrometry to the extent that the parent molecular ion was weak in intensity or simply could not be detected. The same hydrolysis observations were also made when the analogues were analyzed by ion trap electron impact (EI) ionization, indicating the hydrolysis event was the result of the ion trap and not ionization technique. Ion‐trap‐mediated hydrolysis has been observed previously in prior alkenyldiarylmethane studies and prevented characterization of certain intermediates; thus, we wished to investigate whether modifying instrument parameters and protocols affected the instrument‐mediated hydrolysis event. Unfortunately, varying the maximum injection time and the number of microscans performed, independent of each other, had little effect on the intensities of the parent ions [MH+] or the hydrolysis products]MH+HSCH3]. Copyright © 2008 John Wiley & Sons, Ltd.
Rapid identification of differentiation markers from whole epithelial cells by matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry and statistical analysis
Authors: Marvin‐Guy Laure F. , Duncan Peter , Wagnière Sandrine , Antille Nicolas , Porta Nadine , Affolter Michael , Kussmann Martin
Published: March 2008

Matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS) was applied to identify markers for cellular differentiation. The differentiation of a human colon epithelial carcinoma T84 cell line was monitored over a period of 28 days by transepithelial electrical resistance (TER) measurements, alkaline phosphatase (AP) assay, and MALDI‐TOF mass spectral fingerprints combined with statistical analysis. MALDI‐MS generated specific mass spectral fingerprints characteristic of cell differentiation. Twenty‐two ions were selected as diagnostic signals of fully differentiated T84 cells. Ten protein ion signals, detected by MALDI‐MS and validated by statistical analysis, were proposed as T84 cell differentiation markers. Among these signals, ubiquitin was identified as a T84 cell differentiation marker by nanospray liquid chromatography/tandem mass spectrometry (nanoLC/MS/MS). Moreover, depending on the concentration of the cells seeded on the growth support, it was possible to predict the timing of the exponential phase and of cellular differentiation by MALDI‐MS‐derived marker ions. MALDI‐TOFMS was compared to other methods for the determination of cellular differentiation: TER measurements are rapid but yield limited information as to the cellular differentiation state. AP assays are more specific for the differentiation state but take more time. By contrast, MALDI‐MS has been found to be a fast, sensitive and precise method for cell differentiation assessment and provides the opportunity for multiplexing and high throughput. Moreover, the consumable costs per assay are very low. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of wettability of surface‐modified hot‐embossed polycarbonate wafers used in microfluidic device fabrication via XPS and ToF‐SIMS
Authors: Tarik Baytekin H. , Wirth Thomas , Gross Thomas , Treu Dieter , Sahre Mario , Theisen Janko , Schmidt Martin , Unger Wolfgang E. S.
Published: March 2008

The wettability of the surfaces inside the microchannels of a microfluidic device is an important property considering a liquid flows through them. Contact angle measurements usually applied to test the wettability of surfaces cannot be used for an analysis of microchannel walls within microfluidic devices. A workaround is the use of surface analytical methods, which are able to reach points of interest in microchannels and may provide information on the surface chemistry established there. In calibrating these methods by using flat polymer wafers, where the contact angle can be measured as usual, data measured in real microchannels can be evaluated in terms of wetting properties. Reference wafers of bisphenol‐A polycarbonate, a polymeric material that is often used in fluidic microdevice fabrication, were treated under different oxygen plasma conditions. The modified surfaces were characterized by using XPS, time of flight (ToF)‐SIMS and atomic force microscope (AFM). Surface chemistry and surface topography have been correlated with contact angle measurements. In addition, effects of ageing or rinsing after plasma treatment have also been investigated. Copyright © 2008 John Wiley & Sons, Ltd.
Psychosocial factors and gender as predictors of symptoms associated with sick building syndrome
Authors: Kinman Gail , Griffin Miriam
Published: March 2008

Sick building syndrome (SBS) refers to a cluster of symptoms that typically worsen when employees are at work and diminish when they leave. A higher prevalence of symptoms is frequently observed among female employees. Although its aetiology is debated, evidence suggests that psychosocial factors might be at least as important as features of the working environment in predicting SBS symptoms. Utilizing a sample of 346 office‐based employees (55 per cent female) located in five buildings with no known environmental problems, this study examined job control, job satisfaction, work‐related mood and negative affectivity as predictors of self‐reported symptoms typical of SBS. The role played by gender in symptom‐reporting was also investigated. Findings revealed that employees who experienced more symptoms reported significantly less job control and job satisfaction and more work‐related depression and anxiety. A positive relationship was also observed between symptom‐reporting and negative affectivity. In contrast to previous research, no gender differences were observed in the prevalence of self‐reported symptoms, but men and women differed in the predictors of symptoms and the proportion of variance explained. The findings suggest that demographic and psychosocial factors, as well as features of the objective physical environment, should be considered in future investigations of SBS. Copyright © 2008 John Wiley & Sons, Ltd.
Die Al Mak Nimir Bridge über den Blauen Nil in Khartoum
Authors: Haumer Wolfram , Gebert Gregor , Reichelt Andreas , Schülke Jens , El‐Dawi Khalid
Published: March 2008

Die Al Mak Nimir Bridge befindet sich im Stadtzentrum der Sudanesischen Hauptstadt Khartoum. Sie verbindet die beiden Stadteile Khartoum und Khartoum North über den Blauen Nil, der an dieser Stelle etwa 450 m breit ist. Die Brücke, die eine Gesamtlänge von 642,5 m und eine Breite von 22 m aufweist, wurde in nur zweijähriger Bauzeit durch eine türkische Baufirma errichtet und im Oktober 2007 dem Verkehr übergeben. Große Teil e der Planung und die Bauüberwachung wurden durch das deutsche Ingenieurbüro Schüßler‐Plan als Consultant des Bauherrn erbracht.

Das Bauwerk ist in Stahlverbundbauweise mit Regelstützweiten von 50 m und einem Hauptfeld von 80 m konzipiert. Bei konstanter Bauhöhe des Brückendecks wird im Bereich des Hauptfeldes eine besondere Lösung erforderlich. Gewählt wurde eine Überspannung durch Schrägseile, die an jeweils zwei außen stehenden Stahlpylonen angreifen. Zum Einsatz kamen Litzenbündel, die am Pylon über einen Sattelpunkt geführt werden. Eine besondere Herausforderung stellte das regelmäßig wiederkehrende Hoch‐wasser des Nils mit bis zu 7 m Höhenunterschied des Wasserspiegels dar. Für die Montage der ca. 3400 t schweren Stahlkonstruktion wurde daher erstmals im Sudan das Taktschiebeverfahren angewendet.

Der Aufsatz beschreibt aus Sicht des Consultant den Entwurf mit seinen statischen und konstruktiven Besonderheiten und geht im zweiten Teil auf die Bauausführung ein, die unter schwierigen Randbedingungen zu realisieren war.
Neubau des Kaiserstegs über die Spree in Berlin
Authors: Krone Martin , Reinke Klaus‐Dieter
Published: March 2008

Der historische Kaisersteg wurde 1898 als 3‐feldrige, sehr filigrane Bogen‐/Hängewerkkonstruktion mit zwei Strompfeilern und einer Länge von 172 m eröffnet und diente den Mitarbeitern der AEG zur direkten Verbindung vom Bahnhof Schöneweide zum Kabelwerk Oberspree. Zum Ende des 2. Weltkrieges wurde das Brückenbauwerk durch die Waffen‐SS gesprengt und nach Kriegsende nicht wieder aufgebaut. Im Zuge eines Neuordnungsprogramms für das Stadtgebiet Schöneweide wurde ein Ersatzneubau des Kaiserstegs vorgesehen. Für die Planung des Ersatzneubaus waren insbesondere die Anforderungen der Schifffahrt mit einem freizuhaltenden Lichtraumprofil von 75,00 m – 5,25 m und einer außermittigen Lage des Fahrbandes zu berücksichtigen. Unter diesen Randbedingungen war abweichend von der historischen Brückenkonstruktion die Ausführung nur eines Strompfeilers möglich. Das Bauwerk wurde daher als schrägseilverspannter, 2‐Feldträger mit Stützweiten von 48,3 m – 92,0 m und einem ca. 30m hohen Pylon geplant. Im September 2007 wurde nach 2‐jähriger Bauzeit der Kaisersteg als Fußgänger‐ und Radwegbrücke eröffnet. In folgendem Aufsatz wird über Aspekte der Ausführungsplanung und Bauausführung berichtet.
Beulverhalten gedrückter Kastenprofile mit verschiedenen Steifen
Authors: Shigematsu Tsunemi , Ohga Mitao , Hara Takasi
Published: March 2008

Es wird eine analytische Methode zum linearen Beulproblem von Kastenprofilen mit Platten‐, Trapezsteifen und L‐förmigen Steifen vorgestellt. Mit Hilfe des Übertragungsmatrizenverfahrens konnte eine genaue Lösung für das Verzweigungsproblem von gedrückten Kastenprofilen mit Steifen gewonnen werden. Als Ergebnisse werden im folgenden Beitrag zwei unterschiedliche Beulverhalten und ein Knickverhalten vorgestellt. Bei dem ersten Beulphänomen tritt eine Beulform auf, so dass an jeder Stelle einer Versteifung im Kastenquerschnitt ein Knotenpunkt liegt. Als zweites Phänomen tritt eine Beulform jeder einzelnen Platte auf, aus denen sich das Kastenprofil zusammensetzt.
Attitudes of Medical Students toward Careers in General Surgery
Authors: Tambyraja Andrew L. , McCrea Caroline A. , Parks Rowan W. , Garden O. James
Published: March 2008

Background

Changes to general surgical undergraduate curricula, alongside changes in work force and postgraduate training, may be associated with a decline in interest in surgical careers. This study examines the attitudes of students toward surgical training and their career intentions.

Methods

A prospective, questionnaire‐based survey was submitted to final year students at the end of their general surgery attachment over a single academic year at a UK medical school. Career ambitions and reasoning were assessed.

Results

Of 223 eligible students, 193 (87%) completed the questionnaire. There were 118 (61%) females and 75 (39%) males with a median (range) age of 23 (21–41) years. Ninety‐eight (51%) respondents undertook their placement at a Teaching Hospital, whereas 93 (41%) were attached to a District General Hospital. One‐hundred forty‐three (74%) students felt that a four‐week attachment had given them a satisfactory exposure to General Surgery, and 36 (19%) disagreed. Sixty‐eight (53%) students were unable to select a single specialty that they would most like to pursue as a future career. Of the remainder, 23 (12%) chose general surgery, 24 (12%) chose general medicine, and 22 (11%) chose general practice. Seventy‐eight (40%) students would consider a career in general surgery, and 75 (39%) would not; 40 (29%) were undecided. The two most popular attractions to general surgery were challenging postgraduate training and highly regarded career esteem. The two most common disincentives were family considerations and the sacrifice of personal time.

Conclusions

Fewer than half of the final year medical students surveyed were willing to consider general surgery as a future career choice. Potential disincentives should be targeted to promote recruitment into the specialty
High Success Rate of Parathyroid Reoperation may be Achieved with Improved Localization Diagnosis
Authors: Hessman Ola , Stålberg Peter , Sundin Anders , Garske Ulrike , Rudberg Claes , Eriksson Lars‐Gunnar , Hellman Per , Åkerström Göran
Published: March 2008

Introduction

Because of the difficulty of reoperative parathyroid surgery, preoperative imaging studies have been increasingly adopted. We report the use of consistently applied localization diagnosis to yield high success rates in parathyroid reoperations.

Methods

Parathyroid reoperation was performed after previous parathyroid surgery in 144 patients with nonmalignant hyperparathyroidism (HPT) between 1962 and 2007. From the year 2000, 46 patients who underwent parathyroid reoperation and 14 patients who were subjected to thyroid surgery before primary parathyroid operation were investigated with sestamibi scintigraphy (MIBI), 11C‐methionine PET/CT (met‐PET), surgeon‐performed ultrasound (US), US‐guided fine‐needle aspiration biopsy (US‐FNA), and selective venous sampling (SVS) with rapid PTH (Q‐PTH) analyses. When imaging was considered adequate, additional studies were generally not obtained.

Results

Reversal of hypercalcemia was achieved by reoperation in 134 of 144 (93%) of all patients with previous parathyroid surgery. In patients operated from year 2000, MIBI had 90% sensitivity and 88% predictive value, met‐PET 79% sensitivity and 87% predictive value, and US 72% sensitivity and 93% predictive value. SVS with Q‐PTH analyses provided accurate localization or regionalization in 11 of 11 recently selected patients. Q‐PTH analyses in fine‐needle aspirations verified parathyroid origin of excised specimens, and intraoperative Q‐PTH helped decide when operations could be terminated. In patients subjected to the algorithm of imaging procedures, reversal of hypercalcemia and apparent cure was obtained after the reoperation in 45 of 46 patients with previous parathyroid surgery, implying a success rate of 98%, and in all patients with previous thyroid surgery.

Conclusions

Reoperative parathyroid surgery is challenging. Results can be improved by consistently applied sensitive methods of preoperative imaging, and reoperative procedures may then achieve nearly the same success rates as primary operations.
Syntheses and Characterization of Some Cationic Surfactants
Authors: Shehata H. A. , El‐wahab A. A. Abd , Hafiz A. A. , Aiad I. , Hegazy M. A.
Published: March 2008

A series of novel cationic surfactants were synthesized from the quaternization of triethyl amine and various long chain alkyl halide. The chemical structure of the prepared compounds was confirmed using elemental analysis, FTIR and 1H‐NMR spectra. The physical properties of the synthesized surfactants including, electrical conductivity, critical micelle concentration, (CMC) and the degree of ionization of the micelle, (β) were studied. The thermodynamic parameters of micelle formation, standard free energy ΔGm°, enthalpy ΔHm°, and entropy ΔSm° were calculated. The results of the surface parameter determination were correlated with their chemical structures. It was found that the hydrocarbon chain length is the main factor which has an effect on the value of the thermodynamic parameters.
Structural Importance of the Acyl Group in Substrate Specificity of Purified Bovine Lysophospholipase D
Authors: Liu Xi‐Wen , Sok Dai‐Eun , Yook Hong‐Sun , Sohn Cheon‐Bae , Ly Sun Yung , Kim Mee Ree
Published: March 2008

The structural importance of the acyl group in lysophosphatidylcholine (LPC) as substrate of purified bovine lysophospholipase D (lysoPLD) was investigated. Among LPCs with saturated acyl chains, the Km value decreased according to the length of the acyl chain (C12–C16) up to the palmitoyl group, while the Vm value showed no remarkable change. But, the extension of the acyl size to C18, as observed with 1‐stearoyl LPC (Km, 8.5 mM), rather resulted in a remarkable increase in the Km value. Meanwhile, the introduction of one double bond in the C18 saturated acyl chain led to a remarkable reduction in the Km value, as observed with 1‐oleoyl LPC (Km, 0.48 mM). Furthermore, 1‐linoleoyl LPC (Km, 56 μM) with two double bonds exhibited a smaller Km value than 1‐oleoyl LPC, suggesting that the unsaturation degree might be important in augmenting the binding affinity of LPCs. A similar phenomenon was also observed with 1‐arachidonoly LPC (Km, 79 μM) or 1‐docosahexaenoyl LPC (Km, 36 μM). Overall, the order of catalytic efficiency (Vm/Km value) of those LPCs seemed to be affected by the Km value rather than the Vm value, which differed by at most threefold among LPC derivatives. Next, the introduction of a hydroperoxide group into 1‐linoleoyl‐LPC or 1‐arachidonoyl LPC led to a further reduction in Km values (1‐hydroperoxylinoleoyl LPC, 26 μM; 1‐hydroperoxyarachidonoyl LPC, 33 μM), accompanied by a further increase in the Vm/Km values. Additionally, phosphatidylcholines (PCs) with an oxidized acyl chain at sn‐2 position were found to be efficient as 1‐palmitoyl LPC as substrates of lysoPLD. Taken together, the catalytic efficiency of LPCs or oxidized PCs as substrates of lysoPLD seems to be determined by the property of the acyl chain, length of the acyl chain, unsaturation degree and oxidation status.
Hepatic and Adipose Tissue Depot‐Specific Changes in Lipid Metabolism in Late‐Onset Obese (LOB) Rats
Authors: Frick Fredrik , Hume Randip , Robinson Iain C. , Edén Staffan , Oscarsson Jan
Published: March 2008

Transgenic Late‐onset OBesity (LOB) rats slowly develop a male‐specific, autosomal dominant, obesity phenotype with a specific increase in peri‐renal white adipose tissue (WAT) depot and preserved insulin sensitivity (Bains et al. in Endocrinology 145:2666–2679, 2004). To better understand the remarkable phenotype of these rats, the lipid metabolism was investigated in male LOB and non‐transgenic (NT) littermates. Total plasma cholesterol (C) levels were normal but total plasma triacylglycerol (TAG) (2.8‐fold) and hepatic TAG content (25%) was elevated in LOB males. Plasma VLDL‐C and VLDL‐TAG levels were higher while plasma apoB levels were 60% lower in LOB males. Increased hepatic TAG secretion explained the increased VLDL levels in LOB males. The hepatic gene expression of FAS, SCD‐1, mitochondrial (mt)GPAT, and DGAT2 was up‐regulated in both old obese and young non‐obese LOB rats. Lipoprotein lipase (LPL) activity in heart and epididymal white adipose tissue (WAT) was unchanged, while LPL activity was increased in peri‐renal WAT (30%) and decreased in soleus muscle (40%). Moreover, FAS, SCD‐1 and DGAT2 gene expression was increased in peri‐renal, but not in epididymal WAT. Basal lipolysis was reduced or unchanged and β‐adrenergic stimulated lipolysis was reduced in WAT from both old obese and young non‐obese LOB rats. To summarize, the obese phenotype of LOB male rats is associated with increased hepatic TAG production and secretion, a shift in LPL activity from skeletal muscle to WAT, reduced lipolytic response in WAT depots and a specific increase in expression of genes responsible for fatty acid and TAG synthesis in the peri‐renal depot.
Use of complementary and alternative medicine by patients attending a head and neck oncology clinic
Authors: Shakeel M , Newton J R , Bruce J , Ah-See K W
Published: March 2008

Introduction:

Within the United Kingdom, there are 50 000 practitioners of complementary and alternative medicine, with five million people consulting these practitioners yearly. The aim of this study was to explore the use of such therapies by patients attending a head and neck oncology clinic in Aberdeen.

Method:

Questionnaires were distributed to 200 patients over an eight-week period. The questionnaire consisted of questions regarding: demographic factors; 48 listed herbal preparations and alternative therapies; reasons for their use; and opinions on their efficacy.

Results:

One hundred and thirty-eight patients completed the questionnaires. Fifty per cent (69/138) of respondents had used complementary and alternative medicine previously, with 26 per cent having used it in the preceding year. Fifty-five per cent of respondents learned about complementary and alternative medicine use from friends, and the majority obtained such medicines by purchasing from a shop. Fifty per cent (34/69) of respondents stated that their family physician was unaware of their use of complementary and alternative medicine.

Conclusion:

All medical practitioners should be aware of increasing complementary and alternative medicine usage by the United Kingdom population, and should be able to counsel patients appropriately.
Another reason for intra-operative imaging during cochlear implantation
Authors: Viccaro M , De Seta E , Covelli E , Marvaso V , Filipo R
Published: March 2008

Objective:

We report a case of a rare cochlear implant complication: the introduction of the electrode array into the superior semicircular canal, with intra-operative measurements of neural response reactions suggesting reasonable functioning of the implant.

Case report:

A two-year old patient affected by congenital, profound, sensorineural deafness underwent bilateral cochlear implantation at the ENT clinic of the ‘La Sapienza’ University of Rome. Two Clarion 90k devices were implanted, and electrophysiological and radiological checks were performed. After the introduction of the array in the right side, neural response imaging was performed, and a neural potential was found only on two apical electrodes, at a stimulation intensity of 431 clinical units. The situation differed on the left side, where neural response imaging was present at a stimulation intensity of 300 clinical units on the two electrodes tested (one apical electrode (number three), and one middle electrode (number nine)). Intra-operative radiological assessment with a transorbital plain films was performed as usual in order to assess the position of the electrodes inside the cochlea. This radiography showed the electrode array to be in the superior semicircular canal in the right ear.

Conclusion:

Intra-operative monitoring tests during cochlear implant surgery play different roles; measurement of impedances and neural response imaging can evaluate the integrity of implant electrodes and the status of the electrode–cochlea interface, but it must not be the sole way in which correct positioning of the array is confirmed. In our opinion, intra-operative radiological assessment is mandatory during cochlear implant surgery.
Geographic distribution, habitat association, and conservation status of the Critically Endangered Minas Gerais Tyrannulet Phylloscartes roquettei
Authors: Esteves Lopes Leonardo , Hoffmann Diego , Maldonado-Coelho Marcos , Ribeiro Luiz Edson , D'angelo Neto Santos
Published: March 2008

The Minas Gerais Tyrannulet Phylloscartes roquettei is currently classified as a Critically Endangered species, and is one of the most poorly known Neotropical birds. Here we report seven new localities for the species in the São Francisco river basin, raising to 17 the number of localities where this species is known to occur. The range of this species was estimated at 33,500 km2, covering a wider habitat spectrum than previously thought, including, in addition to dry forests, riparian and semi-deciduous forests. We believe this species is overlooked because its voice is generally unknown and available plates in field guides are inaccurate.

O cara-dourada Phylloscartes roquettei é atualmente classificado como Criticamente Ameaçado, sendo uma das espécies de aves Neotropicais menos conhecidas. Neste trabalho são apresentadas sete novas localidades de ocorrência da espécie para a bacia do Rio São Francisco, elevando para 17 o número de localidades onde ela é conhecida. A área de ocorrência desta espécie foi estimada em 33,500 km2, ocupando uma gama de hábitats mais ampla do que o suposto anteriormente, incluindo, além das florestas secas, as florestas ciliares e semidecíduas. Acredita-se que esta espécie esteja passando despercebida devido ao desconhecimento de sua voz e à imprecisão das pranchas nos guias de campo disponíveis.
Taxonomic and conservation implications of ecological speciation in Nesospiza buntings on Tristan da Cunha
Authors: Ryan Peter G.
Published: March 2008

In addition to protecting species, conservation also includes the maintenance of evolutionary processes, but this aspect is often overlooked. Nesospiza buntings provide a good case study of the need to conserve evolutionary processes. They are endemic to the South Atlantic Tristan da Cunha archipelago, and traditionally have been treated as two species, with each having different subspecies on Nightingale and Inaccessible Islands. Both species are listed as Vulnerable because of their small ranges (<20 km2) and the threat posed by the possible introduction of alien organisms such as mice or rats. The two species differ markedly in size, especially bill size, related to dietary differences. However, recent research suggests that morphological diversity evolved independently on Nightingale and Inaccessible Islands, necessitating a revision of the taxonomy within the genus. I recommend that five taxa be recognized, with two endemic to Nightingale and three to Inaccessible Island. N. wilkinsi and N. questi on Nightingale are well-defined species, but there is considerable hybridization between taxa on Inaccessible Island. These three taxa may be incipient species, but are perhaps best treated as subspecies: N. acunhae acunhae, N. a. dunnei and N. a. fraseri (nom. nov.). All three species qualify as threatened, with N. acunhae and N. questi Vulnerable and N. wilkinsi Endangered. With fewer than 200 individuals, N. wilkinsi has one of the smallest natural populations of any bird. A reassessment of its population size is a conservation priority, following the 2001 storm that damaged many Phylica trees on Nightingale Island. Improved biosecurity quarantine measures are also needed for Nightingale Island. Care should be taken not to disrupt the natural processes occurring among bunting taxa on Inaccessible Island.
Waterbird population estimates for a key staging site in Kazakhstan: a contribution to wetland conservation on the Central Asian flyway
Authors: Schielzeth Holger , Eichhorn Götz , Heinicke Thomas , Kamp Johannes , Koshkin Maxim A. , Koshkin Alexej V. , Lachmann Lars
Published: March 2008

Realistic population size estimates for waterbirds are crucial for the application of wetland conservation strategies, since the identification of internationally important wetlands is based on local numbers relative to the population size of the respective species. Central Asia is a poorly surveyed region that is situated at the intersection of migration routes that lead waterbirds from Western Siberia to the south-west (South-West Asia, East Africa) and to the south-east (South Asia, India). We calculated waterbird population estimates for the Tengiz–Korgalzhyn region, a large wetland complex in the steppe zone of Central Kazakhstan, based on waterbird surveys conducted between 1999 and 2004. For 20 of 43 species analysed the region supported more than 5% of the relevant flyway populations. Five species occurred with more than 40% of the flyway totals, including the Endangered White-headed Duck Oxyura leucocephala and the Vulnerable Dalmatian Pelican Pelecanus crispus. Peak numbers were recorded in summer and autumn and for most species numbers were more than an order of magnitude lower on spring migration compared with autumn migration. We identified 72 individual sites that held more than 20,000 waterbirds or more than 1% of a particular flyway population at least once. These sites are likely to constitute priorities for conservation. The general conservation status of the region is favourable, since many of the important sites are located within a strict nature reserve. However, outside the reserve hunting, fishing and powerline casualties represent conservation issues that should be monitored more carefully in the future.
Optimization of the Media Ingredients for Cutinase Production from Colleotrichum lindemuthianum Using Mixture Design Experiments
Authors: Rispoli Fred , Shah Vishal
Published: March 2008

Optimal concentrations of yeast extract, glucose and potassium phosphate in the fermentation medium have been identified for the maximum cutinase production from the fungi Colleotrichum lindemuthianum. A simplex lattice experimental design for mixtures was used to identify concentration ranges that yield maximum production. Three sets of experiments were performed all involving three ingredients. The sets of experiments differ in the number of concentration levels considered. In the first set we consider four concentration levels (i.e., 0%, 33%, 67%, 100%), and in the second and third sets we consider five and six levels, respectively. Results showed that the interactions among the nutrient ingredients are best captured when five‐ and six‐level experiments are carried out. An algorithm has been proposed in this study to design the optimal medium. Various models were also developed to predict the enzyme production, and it is concluded that the cubic model obtained using six‐level experimental data gives the best model. The study also highlighted the synergistic interaction between yeast extract and glucose toward cutinase production.
Using topographic signatures to classify internally and externally driven tilt anomalies at Merapi Volcano, Java, Indonesia
Authors: Westerhaus Malte , Altmann Johannes , Heidbach Oliver
Published: March 2008

A 3‐dimensional Finite‐Element‐Model of Merapi Volcano was developed to calculate the surface deformation field in response to internal pressure variations. The model geometry is based on a new Digital Elevation Model with a grid size of 15 m and an accuracy of 7 m. This allows an investigation of local effects due to radially striking features like deeply eroded canyons, separated by narrow ridges. Close to the ridge margins, topographic disturbances are invoked with amplitudes comparable to the expected signal on a smooth surface. Comparison of the model results with observed tilt records at four locations reveals that topographically induced tilts exhibit a certain pattern that differs systematically from the spatial characteristics of tilt disturbances induced by meteorology. We conclude that a monitoring of the difference of two instruments located at opposite ridge margins provides a simple test to discriminate externally from internally driven tilt anomalies.
Light elements in the core: Effects of impurities on the phase diagram of iron
Authors: Côté Alexander S. , Vočadlo Lidunka , Brodholt John P.
Published: March 2008

The stable phase of iron (Fe) in the Earth's core has been the subject of extensive studies, yet still remains controversial. Hexagonal close‐packed structure (hcp) is the accepted stable form of pure Fe; however, it has been recently proposed that a body‐centered‐cubic (bcc) structured alloy of Fe with lighter elements would be a strong candidate. Experiments and ab initio calculations have shown that small amounts of silicon can stabilize the bcc phase with respect to the hcp phase. In this study we examine the effect at core conditions by adding small concentrations of carbon (C), sulphur (S) and oxygen (O) to iron using electronic structure calculations. We analyze the effect of the light elements on the energy difference between the two structures, and we conclude that the bcc phase tends to be stabilized by the alloys, strengthening the case for a bcc‐structured inner core of the Earth.
Eddy heat diffusion and Subantarctic Mode Water formation
Authors: Sallée J.‐B. , Morrow R. , Speer K.
Published: March 2008

Subantarctic mode waters (SAMW) form in the deep winter mixed layers occuring north of the Subantarctic Front (SAF). The recent increase of hydrographic and surface drifter data in the Southern Ocean allows a better spatial representation of the distinct regions of SAMW formation. This study focuses on the thermodynamical processes acting on the winter mixed layer heat budget. Eddy heat diffusion play a substantial role in the local heat balance, whereas its action vanishes with large‐scale averaging. South of the western boundary currents and north of the SAF, the eddy heating plays an important role in specific regions, counterbalancing the cooling of the mixed layer by Ekman advection and air‐sea fluxes. Specifically, the eddy diffusion term reduces the tendency for mixed layer destabilisation north of the SAF in the Western Indian Ocean downstream of the Agulhas Retroflection and in the Western Pacific downstream of Campbell Plateau. This role for mixed layer eddy fluxes emphasizes a large‐scale control of mixed layer properties by topography and mesoscale processes in the Southern Ocean.