bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement and characterization of RF nonuniformity over the heart at 3T using body coil transmission
Authors: Sung Kyunghyun , Nayak Krishna S. 
Published: February 2008

AbstractPurposeTo measure and characterize variations in the transmitted radio frequency (RF) (B1+) field in cardiac magnetic resonance imaging (MRI) at 3 Tesla. Knowledge of the B1+ field is necessary for the calibration of pulse sequences, image‐based quantitation, and signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) optimization.Materials and MethodsA variation of the saturated double‐angle method for cardiac B1+ mapping is described. A total of eight healthy volunteers and two cardiac patients were scanned using six parallel short‐axis slices spanning the left ventricle (LV). B1+ profiles were analyzed to determine the amount of variation and dominant patterns of variation across the LV. A total of five to 10 measurements were obtained in each volunteer to determine an upper bound of measurement repeatability.ResultsThe amount of flip angle variation was found to be 23% to 48% over the LV in mid‐short‐axis slices and 32% to 63% over the entire LV volume. The standard deviation (SD) of multiple flip angle measurements was <1.4° over the LV in all subjects, indicating excellent repeatability of the proposed measurement method. The pattern of in‐plane flip angle variation was found to be primarily unidirectional across the LV, with a residual variation of ≤3% in all subjects.ConclusionThe in‐plane B1+ variation over the LV at 3T with body‐coil transmission is on the order of 32% to 63% and is predominantly unidirectional in short‐axis slices. Reproducible B1+ measurements over the whole heart can be obtained in a single breathhold of 16 heartbeats. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Venomics: unravelling the complexity of animal venoms with mass spectrometry
Authors: Escoubas P. , Quinton L. , Nicholson G. M. 
Published: February 2008

AbstractAnimal venoms and toxins are now recognized as major sources of bioactive molecules that may be tomorrow's new drug leads. Their complexity and their potential as drug sources have been demonstrated by application of modern analytical technologies, which have revealed venoms to be vast peptide combinatorial libraries. Structural as well as pharmacological diversity is immense, and mass spectrometry is now one of the major investigative tools for the structural investigation of venom components. Recent advances in its use in the study of venom and toxins are reviewed. The application of mass spectrometry techniques to peptide toxin sequence determination by de novo sequencing is discussed in detail, in the light of the search for novel analgesic drugs. We also present the combined application of LC‐MALDI separation with mass fingerprinting and ISD fragmentation for the determination of structural and pharmacological classes of peptides in complex spider venoms. This approach now serves as the basis for the full investigation of complex spider venom proteomes, in combination with cDNA analysis. Copyright © 2008 John Wiley & Sons, Ltd.
Capillary electrophoretic chiral separation of Cinchona alkaloids using a cyclodextrin selector
Authors: Tsimachidis Dimitrios , Česla Petr , Hájek Tomas , Theodoridis Georgios , Jandera Pavel 
Published: February 2008

AbstractA new capillary electrophoretic method for the chiral separation of four major Cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine) was developed using heptakis‐(2,6‐di‐O‐methyl)‐β‐cyclodextrin as the chiral selector. The inner walls of the separation capillary were modified with a thin polyacrylamide layer, which substantially reduced the electroosmotic flow and improved the chiral resolution and the reproducibility of the migration time of the analytes. Various operation parameters were optimised, including the pH, the capillary temperature, the concentration of the background electrolyte, and the concentration of the chiral selector. Baseline separation of the two diastereomer pairs was achieved in 12 minutes in ammonium acetate background electrolyte pH 5.0 with addition of cyclodextrin in a concentration of 3 mM or higher.
A simple method to optimize the HSCCC two‐phase solvent system by predicting the partition coefficient for target compound
Authors: Han Quan‐Bin , Wong Lina , Yang Nian‐Yun , Song Jing‐Zheng , Qiao Chun‐Feng , Yiu Hillary , Ito Yoichiro , Xu Hong‐Xi 
Published: February 2008

AbstractA simple method was developed to optimize the solvent ratio of the two‐phase solvent system used in the high‐speed counter‐current chromatography (HSCCC) separation. Some mathematic equations, such as the exponential and the power equations, were established to describe the relationship between the solvent ratio and the partition coefficient. Using this new method, the two‐phase solvent system was easily optimized to obtain a proper partition coefficient for the CCC separation of the target compound. Furthermore, this method was satisfactorily applied in determining the two‐phase solvent system for the HSCCC preparation of pseudolaric acid B from the Chinese herb Pseudolarix kaempferi Gordon (Pinaceae). The two‐phase solvent system of n‐hexane/EtOAc/MeOH/H2O (5:5:5:5 by volume) was used with a good partition coefficient K = 1.08. As a result, 232.05 mg of pseudolaric acid B was yielded from 0.5 g of the crude extract with a purity of 97.26% by HPLC analysis.
Tourist satisfaction and beyond: tourist migrants in Mallorca
Authors: Bowen David , Schouten Alexander F. 
Published: February 2008

AbstractThis exploratory study analyses the role of tourist experience, especially tourist satisfaction, in subsequent migration from the UK to the municipality of Calviá, Mallorca, Spain. An overview and commentary is provided of theory relating to both tourist satisfaction and migration. Through a series of elite interviews, in‐depth micro‐studies and a questionnaire, which provides a small quantitative component, it is established that the motivation given by tourist satisfaction can be recognised as a key catalyst for migration. Classic migration motivations cannot be entirely discounted, and the migration decisions are multi‐stage through time. But tourist satisfaction—and particularly the two satisfaction components of performance and emotion—is especially relevant in the micro‐perspective of migration decision‐making. Copyright © 2008 John Wiley & Sons, Ltd.
A histopathologic evaluation of the plasma skin regeneration system (PSR) versus a standard carbon dioxide resurfacing laser in an animal model
Authors: Fitzpatrick R. , Bernstein E. , Iyer S. , Brown D. , Andrews P. , Penny K. 
Published: February 2008

AbstractBackground and ObjectivesA variety of high energy, pulsed, and scanned carbon dioxide lasers are available to perform cutaneous resurfacing. Rhytec has developed a device for skin regeneration that utilizes energy delivered via a burst of nitrogen plasma. This study was undertaken to benchmark the energy outputs of the plasma skin regeneration device as compared to an ultra‐short pulsed carbon dioxide laser (the control device). The two systems were compared for time to complete healing, and the healing response post‐treatment.Materials and MethodsThree Yucatan mini‐pigs were utilized for this study. Following anesthesia, five experimental sites were marked along the skin atop the psoas muscle on each side of the spine. Treatment was applied using either the plasma skin regeneration system or the carbon dioxide laser, with one site remaining untreated as a control. Biopsies were taken from all treatment sites 0, 2, 7, 14, 30, and 60 days following treatment and processed to hematoxylin‐eosin staining. Histopathologic examination was performed by observers blinded as to the treatment conditions.ResultsSkin treated with the plasma skin regeneration device showed a wider range of tissue effects across the energy settings used as compared to the laser treatment. All treatment sites had clinically regenerated epidermis by 7 days after treatment, with active cellular response below the D/E junction noted at the day 30 time‐point at energies ranging from 2 to 4 J.ConclusionThe Rhytec PSR system provides an attractive alternative to standard CO2 laser with good remodeling of tissue architecture. Epidermis regenerated after PSR treatment shows a smoother surface profile than adjacent untreated tissue. Lesers Surg. Med. 40:93–99, 2008. © 2008 Wiley‐Liss, Inc.
Histologic and ultrastructural analysis of melasma after fractional resurfacing
Authors: Goldberg David J. , Berlin Alexander L. , Phelps Robert 
Published: February 2008

AbstractBackground and ObjectiveFractional photothermolysis is a popular treatment option for photodamaged skin and other cutaneous conditions. Recently, successful improvement in melasma has been achieved with this laser system. We undertook this study to evaluate the ultrastructural changes associated with fractional laser treatment of melasma.Study Design/Materials and MethodsTen subjects with skin types III and IV and a clinical diagnosis of epidermal melasma were treated with a 1,550‐nm erbium:glass laser delivering light in a fractional manner (Fraxel SR 750, Reliant Technologies, Inc., Mountain View, CA) every 2 weeks for a total of four sessions. Biopsies were obtained from all subjects both before treatment and at 3 months following the final treatment. All biopsies were analyzed by light and electron microscopy for treatment‐induced changes. In addition, a secondary endpoint of the study was to assess for clinical improvement in melasma following fractional resurfacing. This assessment was performed by the investigator using pre‐ and post‐treatment photographs.ResultsLight microscopy on post‐treatment specimens showed a relative decrease in melanocytes compared to the pre‐treatment ones. Post‐treatment electron microscopy revealed fewer melanocytes and a relative absence of melanin in the surrounding keratinocytes compared to pre‐treatment specimens. In addition, six subjects with skin type III were determined to have good improvement, whereas four subjects with skin type IV had fair improvement, as assessed by the investigator.ConclusionPost‐treatment ultrastructural changes are consistent with an elimination process and may help to explain clinical improvement following laser treatment. Lesers Surg. Med. 40:134–138, 2008. © 2008 Wiley‐Liss, Inc.
Relevance of the structure of time‐resolved spectral output to light‐tissue interaction using intense pulsed light (IPL)
Authors: Ash Caerwyn , Town Godfrey , Bjerring Peter 
Published: February 2008

AbstractBackground and ObjectivesHigh quality IPLs can offer simple, safe and effective treatments for long‐term hair removal, removal of benign vascular and pigmented skin abnormalities, skin rejuvenation and acne treatments. Significant differences in clinical outcome have been recorded among different free‐discharge and constant current IPLs despite identical settings. We investigated the differences in optical output of 19 IPLs in normal clinical use in the UK to evaluate spectral output, energy density values and pulse structure and propose a correlation between light‐tissue interaction and spectral output as measured by time‐resolved photo‐spectrometry.Study Design/Materials and MethodsUsing a fast spectrometer, generating 1,000 full spectral scans per second, time resolved spectral data of IPL outputs was captured with a resolution of 0.035 nm. IPL spectral outputs were calculated and graphically modelled using MathCAD™ software for comparison.ResultsSeveral IPLs, which professed matching of pulse durations to the thermal relaxation times of specific follicular or vascular targets were shown to have effective pulse durations that were vastly shorter than those claimed. Some IPLs claiming ‘square pulse’ characteristics failed to show constant spectral output across the duration of the pulse or sub‐pulses.ConclusionsThis study provides a suitable method to determine accurately key parameters of the emitted light pulses from IPLs and confirms the direct correlation between the electrical discharge current profile and the output energy profile. The differences measured between first generation free discharge systems and modern square pulse systems may have important clinical consequences in terms of different light‐tissue interactions and hence clinical efficacy and safety. IPL manufacturers should provide time‐resolved spectroscopy graphs to users. Lesers Surg. Med. 40:83–92, 2008. © 2008 Wiley‐Liss, Inc.
Micro‐fractional ablative skin resurfacing with two novel erbium laser systems
Authors: Dierickx Christine C. , Khatri Khalil A. , Tannous Zeina S. , Childs James J. , Cohen Richard H. , Erofeev Andrei , Tabatadze David , Yaroslavsky Ilya V. , Altshuler Gregory B. 
Published: February 2008

AbstractBackground and ObjectivesFractional ablation offers the potential benefits of full‐surface ablative skin resurfacing while minimizing adverse effects. The purpose of this study was to evaluate the safety, damage profile, and efficacy of erbium fractional lasers.Materials and MethodsHistology from animal and human skin as well as clinical evaluations were conducted with erbium YAG (2,940 nm) and erbium YSGG (2,790 nm) fractional lasers varying pulse width, microbeam (µb) energy, number of passes, and stacking of pulses.ResultsSingle‐pulse treatment parameters from 1 to 12 mJ per 50–70 µm diameter microbeam and 0.25–5 milliseconds pulse widths produced microcolumns of ablation with border coagulation of up to 100 µm width and 450 µm depth. Stacking of pulses generated deeper microcolumns. Clinical observations and in vivo histology demonstrate rapid re‐epithelization and limited adverse side effects. Facial treatments were performed in the periorbital and perioral areas using 1–8 passes of single and stacked pulses. Treatments were well‐tolerated and subjects could resume their normal routine in 4 days. A statistically significant reduction in wrinkle scores at 3 months was observed for both periorbital and perioral wrinkles using blinded grading. For periorbital treatments of four passes or more, over 90% had ≥1 score wrinkle reduction (0–9 scale) and 42% had ≥2. For perioral wrinkles, over 50% had substantial improvements (≥2).ConclusionThe clinical observations and histology findings demonstrate that micro‐fractional ablative treatment with 2,790 and 2,940 nm erbium lasers resulted in safe and effective wrinkle reduction with minimal patient downtime. The depth and width of the ablated microcolumns and varying extent of surrounding coagulation can be controlled and used to design new treatment procedures targeted for specific indications and areas such as moderate to severe rhytides and photodamaged skin. Lesers Surg. Med. 40:113–123, 2008. © 2008 Wiley‐Liss, Inc.
Ablative targeting of fatty‐tissue using a high‐powered diode laser
Authors: O'Dey Dan mon , Prescher Andreas , Poprawe Reinhart , Gaus Sebastian , Stanzel Sven , Pallua Norbert 
Published: February 2008

AbstractBackground and ObjectiveConcerning current clinical practice, laser‐assisted lipoplasty is still secondary to other procedures. In order to evaluate effects of thermal interaction with fatty‐tissue, a near infrared diode laser was examined under reproducible conditions.MethodsBased on optical spectroscopy of fatty‐tissue, a high‐powered diode laser (λ = 940 nm) was used to irradiate n = 59 fat samples of fresh corpses in non‐contact mode. Thermal effects were histologically evaluated by computer based metric measurements. Calculated values included ablation rate (AR) and the ratio of cavity diameter to diameter of collateral damage (CCDratio). Pearson's correlation and analysis of covariance (ANCOVA) were used for statistical evaluation. P values of less than 0.05 were considered to indicate statistical significance.ResultsRegarding the conditions examined, irradiances from 250 to 400 W/cm2 revealed both increased ablation capacities and decreased collateral damages. An average irradiance of 370±0 W/cm2 shows an average CCDratio of 2:1 and an average AR of 9.98±7.65 mm3/second.ConclusionNear infrared high‐powered diode laser energy proved to be eligible for tissue protective ablation of fat in vitro. Further studies are necessary to improve efficiency and safety of this procedure. Lesers Surg. Med. 40:100–105, 2008. © 2008 Wiley‐Liss, Inc.
The short pulse carbon dioxide laser versus the colorado needle tip with electrocautery for upper and lower eyelid blepharoplasty
Authors: Rokhsar Cameron K. , Ciocon David H. , Detweiler Susan , Fitzpatrick Richard E. 
Published: February 2008

AbstractBackground/ObjectiveVarious techniques for blepharoplasty have been described, including those performed with the assistance of the short pulse carbon dioxide laser and those performed with the assistance of the Colorado microdissection needle attached to an electrocautery unit. Although the superiority of the carbon dioxide laser to cold steel has been demonstrated for the performance of eyelid blepharoplasty, no studies have ever compared the carbon dioxide laser to the Colorado needle.Study Design/Materials and MethodsThis is a paired comparison study in which 12 healthy patients underwent bilateral blepharoplasty of their upper and/or lower eyelids by a single surgeon. For each patient, a short pulse carbon dioxide laser was used on one side, and a Colorado needle attached to an electrocautery unit was used on the other. Intraoperative times were recorded. At five post‐operative visits patients were evaluated for post‐operative healing parameters including edema, erythema, scar width, and bruising. Finally, excised tissue was assessed histologically for thermal damage.ResultsComparing both techniques, no difference in patient or physician‐measured parameters of healing were noted up to 1 month post‐operatively. However, Colorado needle assisted blepharoplasty resulted in slightly shorter intraoperative times. It also resulted in less thermal damage on a histologic level, although these differences were not clinically significant.ConclusionsFor the performance of blepharoplasty, the Colorado needle tip with electrocautery offers benefits equivalent to those of the short pulsed CO2 laser but has the advantage of shorter intraoperative times and lower cost. Lesers Surg. Med. 40:159–164, 2008. © 2008 Wiley‐Liss, Inc.
Selective transcutaneous delivery of energy to porcine soft tissues using intense ultrasound (IUS)
Authors: White W. Matthew , Makin Inder Raj S. , Slayton Michael H. , Barthe Peter G. , Gliklich Richard 
Published: February 2008

AbstractObjectiveVarious energy delivery systems have been utilized to treat superficial rhytids in the aging face. The Intense Ultrasound System (IUS) is a novel modality capable of transcutaneously delivering controlled thermal energy at various depths while sparing the overlying tissues. The purpose of this feasibility study was to evaluate the response of porcine tissues to various IUS energy source conditions. Further evaluation was performed of the built‐in imaging capabilities of the device.Materials and MethodsSimulations were performed on ex vivo porcine tissues to estimate the thermal dose distribution in tissues after IUS exposures to determine the unique source settings that would produce thermal injury zones (TIZs) at given depths. Exposures were performed at escalating power settings and different exposure times (in the range of 1–7.6 J) using three IUS handpieces with unique frequencies and focal depths. Ultrasound imaging was performed before and after IUS exposures to detect changes in tissue consistency. Porcine tissues were examined using nitro‐blue tetrazolium chloride (NBTC) staining sensitive for thermal lesions, both grossly and histologically. The dimensions and depth of the TIZs were measured from digital photographs and compared.ResultsIUS can reliably achieve discrete, TIZ at various depths within tissue without surface disruption. Changes in the TIZ dimensions and shape were observed as source settings were varied. As the source energy was increased, the thermal lesions became larger by growing proximally towards the tissue surface. Maximum lesion depth closely approximated the pre‐set focal depth of a given handpiece. Ultrasound imaging detected well‐demarcated TIZ at depths within the porcine muscle tissue.ConclusionThis study demonstrates the response of porcine tissue to various energy dose levels of Intense Ultrasound. Further study, especially on human facial tissue, is necessary in order to understand the utility of this modality in treating the aging face and potentially, other cosmetic applications. Lesers Surg. Med. 40:67–75, 2008. © 2008 Wiley‐Liss, Inc.
Treatment of acne scars using the plasma skin regeneration (PSR) system
Authors: Gonzalez Michele J. , Sturgill William H. , Ross E. Victor , Uebelhoer Nathan S. 
Published: February 2008

AbstractBackground and ObjectivesAcne scarring is a common and difficult to treat condition. The plasma skin regeneration (PSR) system is a novel device that causes delayed ablation of the epidermis and controlled thermal modification to the underlying dermis. PSR has previously been shown to be a safe and effective treatment for facial rhytides and benign skin lesions. In this study, we investigated the safety and efficacy of single‐treatment, high‐energy, double‐pass PSR for the treatment of acne scarring.Study Design/Materials and MethodsTen patients with acne scarring and Fitzpatrick skin types I–III were included in the study. All patients underwent a single PSR treatment with two high‐energy passes (3.5–4.0 J). Treatments were performed in an outpatient clinic setting. Nine patients completed 6 months of follow‐up. Improvement was determined by patient questionnaires and physician evaluation of digital photographs taken prior to treatment and at 3 and 6 months post‐treatment.ResultsOn average, patients reported 34% improvement in their acne scarring at 3 months and 33% improvement at 6 months. Blinded physician ratings of patient photos demonstrated 19% improvement at 3 months and 34% at 6 months. Re‐epithelialization was complete by 4–6 days after treatment, and no serious adverse events were encountered.ConclusionPSR appears to provide a safe and effective single treatment, minimal downtime alternative for the treatment of acne scarring. Additional studies are warranted to further demonstrate the safety and efficacy of this device. Lesers Surg. Med. 40:124–127, 2008. © 2008 Wiley‐Liss, Inc.
Structures of the chain metaphosphates NaM(PO3)3 (M = Ca or Sr)
Authors: Abrahams I. , Hawkes G. E. , Ahmed A. , Di Cristina T. , Demetriou D. Z. , Ivanova G. I. 
Published: February 2008

AbstractSolid‐state 23Na and 31P magic‐angle spinning nuclear magnetic resonance spectroscopy and X‐ray crystallography have been used to study the structures of the chain metaphosphates NaCa(PO3)3 and NaSr(PO3)3. The compounds are isostructural and crystallise in space group P−1 with the following parameters: NaCa(PO3)3, a = 6.711 Å, b = 6.934 Å, c = 7.619 Å, α = 83.44° , β = 81.41° , γ = 82.80° ; NaSr(PO3)3a = 6.805 Å, b = 7.133 Å, c = 7.720 Å and α = 83.71° , β = 80.48° , γ = 82.87° . Both structures contain anionic metaphosphate chains of (PO3)nn with ionic contacts to Na+ ions in distorted octahedral sites and Ca2+ (or Sr2+) in distorted dodecahedral sites. 31P and 23Na NMR are entirely consistent with the crystallographic data and an empirical method for assigning 31P resonances to particular crystallographically unique P atoms is described. Copyright © 2008 John Wiley & Sons, Ltd.