bluuebunny/crossref_metadata_2025 huggingface dataset:
Landing frequencies and types of landings in sub-elite male volleyball players
Authors: van Ark M , Zwerver J , Pepping G J
Published: April 2011

Background

Landings seem to be one of the important factors in the multi-factorial aetiology of patellar tendinopathy among jumping athletes.

Objective

The aim of the current study was to investigate the frequencies and types of landings in sub-elite male volleyball players in both matches and training sessions.

Design

Prospective cohort study.

Setting

All landings of players of a Dutch first division volleyball team were analysed during 2 weeks. Five training sessions and two matches took place in this period.

Participants

Players of a sub-elite male volleyball team (n=12).

Intervention and main outcome measurements

Event (match/training session), landing foot (left/right/both), player position and action for which the jump was performed were recorded for every jump. A repeated measures analysis of variance was performed to test for possible effects of the variables event (within-factor), function (between-factor) and landing foot (within-factor) on mean number of landings per person.

Results

7944 landings were evaluated, the number of landings was higher during training sessions than during matches (ratio 5.5:1). 22% of the landings occurred on the left foot, 15% on the right foot and 63% on both feet. Jumps were performed for usual actions like a spike, block or set-up. The players landed significantly more on both feet than on their left or right foot. Setters landed significantly more on both feet than players with other functions and during training sessions landings occurred more on both feet than during matches.

Conclusions

This study showed that far more landings were performed during training sessions compared to matches. Most effects of prevention programs can thus be expected from interventions on landing type and frequency during training sessions. In this way the development of overload injuries like patellar tendinopathy might be prevented.
Effect of altitude training on the renin-angiotensin-aldosterone system and blood pressure in women
Authors: Cruz-Márquez J C , Cruz-Campos J C , Cruz-Campos A , Cueto-Martín MªB , García-Jiménez Mª , Campos-Blasco MªT
Published: April 2011

Background

Altitude training produces advantages over sea level training, but athletes require acclimatization to avoid discomfort or mountain sickness, in which the blood pressure control is essential.

Objective

To investigate the influence of moderate altitude on blood pressure and renin-angiotensin-aldosterone systems in a women's volleyball team (Honor Division – Spain).

Design

We assessed 14 elite female volleyball players: 2 weeks under normoxia conditions (640 m above sea level), 2 weeks under relative hypoxia (2450 m, at the High Performance Centre of Sierra Nevada, Granada, Spain) and two final weeks back to normoxia.

Setting and participants

14 women (mean age 23±2.8 years; height: 184.9±6.9 cm; weight: 73.1±6.2 kg). All players who started the study completed it. None of the participants reported ingesting contraceptives or hormonal treatments.

Interventions

The volleyball players trained twice/day (3 h/session). The blood pressure was measured at rest in the morning, during and after physical exercise (both in the morning and in the afternoon season), as well as in urine/24 h the renin, angiotensin and aldosterone, renal water excretion and urinary volume every 5 days.

Independent variable: Altitude.

Dependent variables: Renin, angiotensin, aldosterone 24/h urinary levels; rest, pre and posttraining blood pressure.

Results

The aldosterone levels decreased in the first hypoxic week (157.09 pg/ml; p<0.05 respect to level), as well as renin levels (12.82 pg/ml p<0.05 respect to level). There was an increase in renal water excretion (25 701.36 ml/day with a p<0.05). The diastolic blood pressure posttraining showed changes between the hypoxia and normoxia (69.72±12.3 vs 73.45±14.9 mm Hg p<0.05).

Conclusions

Renin is reduced under hypoxia. Post-exercise diastolic blood pressure changes significantly at altitude with less venous return and may explain symptoms of mountain sickness.
Assessment of elite-level volleyball players' performance and fitness based on biometric data
Authors: Miyamoto D , Arima S , Ogiuchi T , Netsu M , Kanari S , Yakama K , Hamano I
Published: April 2011

Background

Improvement sought in the performance of a professional volleyball team, eighth in Japanese Premiere Volleyball League 2009-Season, based on collection and analysis of biometric data.

Objective

Physical performance and biometric data were collected from one team of the Japanese Premiere Volleyball League (CT) and the Japanese National Team (NT). The aim is to compare the fitness of CT to NT and analyze differences in athletes of high and low performance.

Design

Measure values in 10 physical performance tests and body-composition.

Setting

The study was conducted in the regular training facility of CT team. Photo-detector and yardstick were used for measurements.

Participants

18 healthy male players on the active roster of CT team were examined. The control consisted of 21 members of NT.

Intervention

Measurements for CT were taken during the 2010 off-season, with NT taken during the same period 2009. The 10 performance tests are: 20 m dash, pro agility, T test, vertical jump, medicine-ball throw, standing triple jump, standing triple long jump, block jump, sit-up, and endurance test. Body-composition parameters are age, height, weight, body mass index, standing reach, vertical jump, and running vertical jump.

Main outcome measurements

We hypothesized NT would show higher numbers than CT in both power and speed tests. Significant difference was found only in the medicine-ball throw, while other tests did not reveal significant differences.

Results

NT had higher numbers in height, weight, and standing reach, recorded higher numbers in medicine-ball throw. CT produced higher numbers in vertical jump.

Conclusions

Since NT displayed higher numbers in medicine-ball throw CT will be required to improve power in order to achieve similar performance. Results also show that NT has slightly higher values in pro agility. This suggests that CT, with their lower body composition figures, also needs to improve agility to perform at the same level as NT.
Play structure of top female volleyball players: explorative factorial approach
Authors: Nesic G , Sikimic M , Ilic V , Stojanovic T
Published: April 2011

Background

Volleyball, as a sports game, requires from the players high level preparedness with respect to all the motor abilities, as well as an efficient execution of necessary technical and tactical game elements.

Objective

The aim of this research is to establish characteristics of the competitive activity structure in female volleyball at European Senior Championships in Bulgaria 2001, in Turkey 2003 and in Croatia 2005.

Design, setting and methods

An overall of 48 games of all three championships were analyzed. Comparative analysis of the latent competitive activity structure of female volleyball players was performed by factorial data analysis (factor rotation in Varimax solution).

Results

In the latent space of competitive analysis, three independent factors were isolated, justifying 73.76% of overall system variance. Factor 1 (space-time factor) explains 36.12% of overall variance and is defined by the following manifest variables: jumps (0.934), active (0.921) and passive (0.906) time of the game and strikes at ball (0.893). Factor 2 (situational precision) explains 21.46% of all variance and is defined by the following manifest variables: efficiency coefficient (KE) of serve receiving (0.940), followed by KE of ball raising for attack (0.829), and the lowest KE is manifested in field defence (0.815). Factor 3 (technical-tactical efficiency) in latent space of competitive activity explains 16.19% of all variance and is defined by the following manifest realization of technical-tactical elements (0.685), and the smallest and negative KE drops in the variables: KE of attack (0.819), serve KE (0.803), KE block (0.711), success in field defence (−0.558).

Conclusions

All the variables significantly contribute to defining of isolated factors, but the greatest contribution belongs to jumps, active and passive time of the game and strikes at the ball, which is logical, because these variables are constant during the entire game. Other variables, that is, isolated factors of situational precision and factors of technical-tactical efficiency, are expressed through them.
Tendinopathy in volleyball elite players: prevalence of injuries, clinical and imaging evaluation
Authors: Aido R , Massada M , Leitão N , Magalhães C , Vasconcelos J C , Lourenço J M , Puga N
Published: April 2011

Background

High level volleyball players are at great risk of suffering rotator cuff and patellar tendinopathy. The symptoms are often serious resulting in long standing impairment of athletic performance.

Objective

The aim of this study was to estimate the prevalence of rotator cuff and patellar tendinopathy in volleyball elite players and correlate clinical examination with the changes observed with ultrasonography and power doppler (US+PD).

Setting, participants and methods

20 Portuguese volleyball players from the senior national team, with mean age of 24.29 years and 11.14 years of average sports volleyball, were evaluated clinically and by US+PD.

Results

80 evaluations were performed: 40 rotator cuff and 40 patellar tendons were assessed. Rotator cuff tendinopathy was diagnosed clinically in seven shoulders (17.50%), all in the dominant member. Eight rotator cuff tendons (20.00%) had structural changes and vascularity on US+PD. All the players with Jobe test painful had structural and vascularity changes on US+PD. Patellar tendinopathy was diagnosed clinically in 12 patellar tendons (30.00%), 6 on the dominant member. 20 tendons (50.00%) had structural changes and vascularity on US+PD. Only one player with patellar tendon palpation painful didn't have structural and vascularity changes on US+PD. According to the player position the opposites were the most affected players.

Conclusions

This research revealed that shoulder and knee are two frequent regions affected by overuses injuries in volleyball elite players. US+PD have good accuracy (with high sensibility) in confirming clinically diagnosed rotator cuff and patellar tendinopathy. The results reported in this study suggest that Jobe test and the palpation of patellar tendon are reliable tests in detecting rotator cuff and patellar tendinopathy.
Incidence of volleyball injuries in elite junior female players: a retrospective cohort study
Authors: Nesic G , Ilic V , Sikimic M , Dopsaj M
Published: April 2011

Background

Injuries in volleyball are quite frequent and most likely caused by increased frequency, intensity and duration of training.

Objective, setting

The aim of the present study was to examine the incidence and mechanisms of injuries among top eight European junior female national teams.

Design, methods

Injury occurrence for the 2009–2010 season were collected by using a questionnaire.

Results

Of the 84 volleyball players (87.50% response rate), a total of 66 (78.54%) female players sustained 75 injuries, representing an overall incidence of 0.89 injuries per player. The national team players of the Czech Republic and Turkey reported the highest number of injuries, while the Italian team had the lowest number of injuries in the past season. An ankle (33.33%) was the most commonly injured region, followed by a knee (20%), fingers (17.33%) and shoulder (16%). Ankle injuries seemed to be more serious problem in the National team players of the Czech Republic (8/13 or 61.53%), while shoulder injuries were most common in the Russian National team (7/12 or 58.33%). Almost half of the reported injuries (48%) occurred in contact with another player. Majority of injuries occurred during training (41.33%), and 48% of all injuries were localized on the left side of the body. Most injuries were associated with play along the net, that is, blocking (41.33%) and spiking (24%). 53% of the injuries were slight or minor causing absence from training session time of less than 1 week.

Conclusions

Although all female players participated in some kind of injury prevention training during preseason or season, more than three-quarters of the players reported an injury during the season, indicating that this vulnerable population is especially sensitive and should be better adapted to training. Also, heterogeneity in localization of incurred injuries among players of different national teams could be observed thought different training techniques.
Injuries in a Russian male professional volleyball team during the 2009–2010 season
Authors: Demin Y M , Shipulin G Y
Published: April 2011

Background

There are few studies of injury rates in Russia's Volleyball Championship.

Objective

To investigate incidence and characteristics of injuries in one male volleyball team.

Design

Prospective cohort pilot study, 2009–2010 (preseason and the competitive season).

Setting

Professional athletes of elite male division of Russia's Championship (Super League).

Participants

16 players had been taking part in preparation and competitions from 23 June 2009 to 15 May 2010 as The ‘Lokomotiv-Belogorie’ volleyball team.

Interventions

Volleyball exposure during training and matches was recorded by the coach. The team physician recorded all injuries which had occurred. The incidence of injury was expressed as number of injuries per 1000 player hours.

Results

105 injuries were recorded, 22 (20.95%) resulted in one or more days of missed practice or competition. The overall incidence of time-loss injuries was estimated as 2.37 per 1000 player hours. The game incidence was 10.7 and the practice incidence was 1.84. Majority of injuries (86.36%) had slight or minor severity. The most common location of time-loss injuries was the ankle/foot (32.82%), followed by the spine/back (27.27%) and shoulder (13.63%). The most common types were sprain (22.73%) and overuse injuries (63.64%). Many slight and overuse injuries did not cause player to stop playing (only 32.6% of the acute and 11.86% of the overuse were time-loss injuries). Among all registered injuries the prevalence locations were spine/back (22 cases or 21.95%), shoulder (21 cases or 20%) and knee (18 cases or 17.14%) and 71.43% were overuse and 28.57% traumatic.

Conclusions

The study revealed a high injury incidence rate in games compared to practice. The majority of injuries were overuse injuries. Slight and minor injuries often occurred and most of them were not time-loss. Future investigations are required.
A guidebook for volleyball-related health problems using Manga and educational activities for injury prevention: Volleyball 911
Authors: Hayashi M , Hamu Y , Hashimoto Y
Published: April 2011

Background

Many Volleyball related health problems occur when players are junior and high school students, but there is a lack of knowledge of sports health issues among players and instructors.

Objective

To educate players and instructors and therefore prevent health problems, by creating a guidebook.

Setting

Medical checkups for volleyball players at all levels often reveal sports related issues including lower back pain, knee pain such as jumper's knee, shoulder pain caused by volleyball spikes, ankle joint sprain, digital deformities and anemia. When the history is examined it is often found that many of these problems began at junior or high school level.

Result

10 years ago, a guidebook for prevention of Volleyball-related injuries and health problems was prepared using easy-to-understand ‘Manga’ (comic-book illustrations) for both junior players and instructors.

Approximately 10 000 copies of the guidebook were distributed for free. Currently, the guidebook is available on the website of the Japan Volleyball Association and educational activities for volleyball related health issues are being conducted.

Conclusions

An English version of the guidebook was prepared for this FIVB Volleyball Medicine Congress. It is our wish that the guidebook be translated into many languages in order to protect valuable junior volleyball players around the world from sports-related injuries.

With the help of the participants in the Congress, we ask that the guidebook be translated into their own languages. The goal is to promote educational activities through the website of the FIVB.
Oxidative stress status in elite female volleyball athletes with depleted iron stores
Authors: Martinovic J , Dopsaj V , Kotur-Stevuljević J , Dopsaj M , Nesic G
Published: April 2011

Background

Oxidative stress has been defined as a disturbance in the equilibrium status of pro-oxidant and antioxidant systems in favour of pro-oxidation. The elevated metabolic rate associated with exercise leads to increased mitochondrial oxygen consumption in tissues, free radical generation, metabolite oxidation and antioxidant depletion.

Objective

The aim of the present work was to examine the association of iron depletion and acute phase response with oxidative stress in female athletes.

Setting and participants

Based on serum ferritin values (cut-off 22 μg/L), 54 elite female volleyball athletes were divided into two groups: with iron depletion and with normal iron stores. Samples were taken from athletes who were members of the top two senior women volleyball teams in Serbia during the 2007/2008 competition season.

Interventions

The following parameters were measured: ferritin, C-reactive protein, interleukin-6, oxidative stress parameters (reactive oxygen metabolites – ROMs and lipid hydroperoxides – LOOH) and antioxidative defence parameters (biological antioxidative potential – BAP and superoxide-dismutase).

Results

A general linear model indicated significant differences between athletes (Wilks's λ=0.698, F=5.092, p=0.002) in reactive oxygen metabolites (278±57 vs 333±56; p=0.001) which were significantly higher in athletes with iron depletion and biological antioxidative potential (2547±257 vs 2366±297; p=0.026) which was significantly lower in this group. Besides iron depletion, multivariate analysis of covariance revealed C-reactive protein (p<0.047) to be significant covariate with 18.2% proportion of variability for superoxide-dismutase activity. Iron depletion accounted for the largest proportion of variability for all oxidative stress parameters (30.2%).

Conclusions

Oxidative stress that occurs during exercise is related to acute phase response and iron depletion plays a significant role in processes that lead to free radical generation in professional athletes. Athletes with ferritin values below 22 μg/L had a decreased antioxidatve defence and were more susceptible to oxidative stress compared to those with adequate iron status.
Two year training induced changes in anthropometric and strength characteristics of national team male volleyball players
Authors: Sheppard J M , Nolan E , Newton R U
Published: April 2011

Background

Several examinations have demonstrated differences in anthropometry, jump performance, and strength variables between developmental and elite level volleyball players. However, within the elite level of play, the magnitude of change that can occur with training is unclear.

Objective

To examine the anthropometric, vertical jump, and strength quality changes over 2 years in a group of national team volleyball players.

Design

Longitudinal analysis with pre and post measurements spanning a 2 year time period.

Setting

A male national volleyball team, involving professional players free of injury.

Participants

15 national team volleyball players (22.0±3.1 years, 1.98±0.09 m, 90.8±9.9 kg) began and completed this study. Participants had all played international matches prior to the examination time period, and continued to do so during the international season, while also playing for their professional club, through the 2 year duration of the study.

Interventions

During professional seasons, match play volume varied depending on club, with training time typically involving four to seven court and two strength sessions per week. During international seasons, participants typically engaged in seven to nine court and two to four strength sessions per week, with match involvement ranging from 15 to 40 per season. Anthropometry (stature, mass, and Σ7 skin-folds, vertical jump measures (counter-movement vertical jump; depth-jump from 0.35 m DJ; spike-jump SPJ), speed-strength (body-weight jump squat, JSBW) and ballistic-strength (jump squat+50% body-weight, JS50) measures were tested prior to and at the conclusion of the investigation period.

Results

Significant (p<0.05) improvements were observed in Σ7 skin-folds, DJ, SPJ, and JS50 performance, with large magnitude changes (Cohen's d>0.70) in the Σ7 skin-folds reduction, and increased jump height for the JS50.

Conclusions

Large improvements in DJ, SPJ, and ballistic strength performance, as well as reductions in fat-mass, can be achieved in senior male national team volleyball players.
Clinicopathological significance of Y416Src and Y527Src expression in breast cancer
Authors: Kanomata Naoki , Kurebayashi Junichi , Kozuka Yuji , Sonoo Hiroshi , Moriya Takuya
Published: April 2011

Aims

To elucidate the clinicopathological significance of Y416Src and Y527Src expression in breast cancer, and to evaluate their usefulness as potential predictive markers for Src inhibitors.

Background

c-Src is a non-receptor tyrosine kinase; the active form of c-Src can catalyse tyrosine phosphorylation. The expression and activity of c-Src correlates with cell adhesion, survival, angiogenesis, migration, invasion and osteoclast function. There are limited clinicopathological data on Src expression and breast cancer characteristics.

Methods

An immunohistochemical study was performed to determine the expression of c-Src, Y416Src, and Y527Src in 215 consecutive breast cancer cases. The correlation of their expression with various clinicopathological factors was analysed statistically.

Results

c-Src was expressed in all 215 cases (100%). Y416Src was expressed in 174 cases (80.9%) and was highly expressed in 30 cases (14.0%). Y527Src was expressed in 138 cases (64.2%) and was highly expressed in 11 cases (5.1%). High expression of Y416Src was significantly associated with metastatic disease (p=0.0327), whereas high expression of Y527Src was significantly associated with metastatic disease (p=0.0004), clinical stage (p=0.0062), as well as HER2 status (p=0.0149). High expression of either Y416Src or Y527Src was significantly correlated with poor overall survival (p=0.0049 and p<0.0001, respectively). In the 192 curatively operated cases, Y416Src expression was significantly associated with poor disease-free survival (p=0.0088).

Conclusion

Although further studies to assess Src activity are necessary, investigation of Src inhibitors for breast cancer including in-vivo models should be encouraged more.
CHANGES IN THE PHASE DIAGRAM OF Zn-DOPED YBCO SINGLE CRYSTALS
Authors: HUSSAIN MANZOOR , TAKITA KOKI
Published: April 2011

The Zn -doped YBCO single crystals were prepared with Zn contents of 0.5%, 1.5%, 2.5%, 3.0% and 4.3%. The magnetic measurements were made under magnetic field up to 5 T using SQUID. The peak effect was observed in these samples in all the measured temperature range from 0.2 ≤ T/Tc ≤ 0.95. The region between peak field Hp and irreversibility field H irr increased consistently with increasing Zn concentration showing broadening in the phase diagram and indicating increased disorder for higher Zn content samples. The anisotropy in the peak field Hp for these samples measured for applied field H along c-axis and along ab-plane (Hp‖c/Hp‖ab) was found to increase from 0.15 to 0.18 for samples with Zn concentration up to 3% and decreased to 0.142 for sample with Zn content of 4.3% at 0.9 Tc. In the temperature range of 0.8–0.95 Tc, the anisotropy in the critical current density (Jc|c/Jc‖ab) was also found to increase in the order of 1.9–2.166 for the samples with Zn content up to 3%, whereas for 4.3% Zn sample it was 0.926. The anisotropic changes in the irreversibility field H irr were also found to be in the range of 0.254–0.279 for the Zn concentration up to 3% and decreased for the 4.3% Zn sample in temp range of 0.8–0.95 Tc. In addition to the effect of local magnetic moments induced by Zn impurity, the changes in the anisotropic factor with the increase of Zn content seems to contribute effectively for increase in Hp, Jc and H irr for Zn contents up to 3% samples even at elevated temperature of 0.8–0.95 Tc. The decrease in Jc and H irr for 4.3% Zn sample may be due to increase in the impurity level beyond threshold leading to decrease in superconducting volume fraction.
THE ELECTRONIC STRUCTURE AND MAGNETISM OF CrSb WITH LATTICE CONSTANTS
Authors: CHEN LI
Published: April 2011

The electronic structure and magnetism of CrSb compounds have been studied by a periodic quantum-mechanical calculation based on density functional theory. The results show that a ferrimagnetic ordered phase of CrSb in the Zinc-blende structure (ZB) is stable with half metallic properties, whereas the antiferromagnetic phase of CrSb in the NiAs -type crystal structure is energetically favored with no-gap band. The lattice constants have significant influence on the magnetism of CrSb . The band gap and the magnetic moment of Cr atom increase with increasing lattice constant in ZB CrSb . The effects on magnetic moment in the NiAs -type crystal structure are more sensitive substantially to the change of lattice constant a as compared with that of the lattice constant c. It is found that apart from ionic or metallic bonds there are covalent bonds between Cr d and Sb p orbitals in ZB CrSb , while bonding between Cr and Sb atoms is mainly ionic or metallic in CrSb of NiAs structure.
SYNTHESIS AND CHARACTERIZATION OF n-BUTYL 4-(3,4-DIMETHOXYPHENYL)-6-METHYL-2-THIOXO-1,2,3,4 TETRAHYDROPYRIMIDINE-5-CARBOXYLATE NANOCRYSTALLINE PARTICLES BY WATER/OIL MICROEMULSION METHOD
Authors: VYAS POORVESH M. , JOSHI MIHIR J. , PANSURIYA AKSHAY M. , NALIAPARA YOGESH T.
Published: April 2011

Various pyrimidine derivatives are well known for their different pharmaceutical applications. The n-butyl 4-(3, 4-dimethoxyphenyl)-6-methyl-2-thioxo-1,2,3,4 tetrahydropyrimidine-5-carboxylate (n-butyl THPM) was synthesized by using n-butylacetoacetate. The n-butyl acetoacetate was obtained by transesterification of ethyl acetoacetate with n-butyl alcohol using Biginelli condensation. The synthesized powder was used to obtain the nanoparticles of n-butyl THPM by using water/oil microemulsion technique. The average particle size was calculated from the powder XRD pattern by applying Scherrer's formula. The nanoparticles of n-butyl THPM were observed by Transmission Electron Microscope (TEM). The diameter of the nanoparticles varied from 15 nm to 65 nm. The nanoparticles were also characterized by FT–IR spectroscopy, TG–DTA–DSC and mass spectroscopy. The n-butyl THPM nanoparticles were stable up to 280°C. Thermodynamic and kinetic parameters of decomposition were obtained by applying Coats and Redfern relation to the thermogram. The dielectric study was carried out in the frequency range of 50 Hz to 5 MHz. The dielectric constant, dielectric loss and ac conductivity decreased as the frequency of applied field increased.
SYNTHESIS OF HYBRID NANOMATERIALS USING LINEAR-DENDRITIC COPOLYMERS
Authors: BAHARI ALI , ADELI MOHSEN , HOSSEINI SONIA MOHAMAD
Published: April 2011

New types of hybrid nanomaterials consisting of CdSe and ZnS quantum dots were synthesized through noncovalent interactions. Polycitric acidpolyethylene glycolpolycitric acid linear-dendritic copolymers were synthesized and sonicated in the presence of amino-functionalized CdSe and ZnS quantum dots (QDs). Based on microscopy and spectroscopy investigations, it has been found that CdSe and ZnS QDs link together through linear-dendritic copolymers bridges. This strategy led to composites containing two types of QDs dispersed in a polymeric matrix. Optical properties of CdSe/ZnS hybrid nanomaterials depended on different factors that affect the noncovalent interactions between linear-dendritic copolymers and QDs.
A VARIATIONAL PRINCIPLE APPROACH FOR BUCKLING OF CARBON NANOTUBES BASED ON NONLOCAL TIMOSHENKO BEAM MODELS
Authors: YANG YANG , LIM C. W.
Published: April 2011

Based on the nonlocal elastic theory and variational principle, new Timoshenko beam models and analytical solutions for buckling of carbon nanotubes considering nanoscale size effect and shear deformation are established. New equilibrium equations and higher-order boundary conditions are derived and the buckling behavior of carbon nanotubes is numerically investigated. The numerical solutions confirm that nanotube stiffness is enhanced by nanoscale size effect and reduced by shear deformation. It is also concluded that nanotubes with different boundary conditions show varying sensitivity to changes in nanoscale and dimension. Comparison with molecular dynamics simulation results verifies the accuracy and reliability of this new analytical nonlocal Timoshenko beam model.
CALCULATIONS OF HIGH DEPENDABILITY ON FLOWING SYSTOLIC ARRAYS FOR TWO MATRIX MULTIPLICATION
Authors: RANDJELOVIĆ DRAGAN M.
Published: April 2011

The objective of this paper is to discuss systolic arrays (SAs) that are suitable for regular three-nested loop algorithms implementation and which enable the possibility of high dependability calculations for the SAs obtained in this way. This is made by considering the different possible values of flow period of processor for SAs synthesized on adaptable algorithms. Therefore, the algorithm for two matrix multiplication is one typical adaptable algorithm obtained results illustrated in the end of this paper by the examples of two rectangular matrix multiplication realized with the so called flowing and hexagonal two dimensional 2D SAs of planar SAs group.
Physiological roles of renal anion transporters NaS1 and Sat1
Authors: Markovich Daniel
Published: April 2011

This review will briefly summarize current knowledge on the renal anion transporters sodium-sulfate cotransporter-1 (NaS1; Slc13a1) and sulfate-anion transporter-1 (Sat1; Slc26a1). NaS1 and Sat1 mediate renal proximal tubular sulfate reabsorption and thereby regulate blood sulfate levels. Sat1 also mediates renal oxalate transport and controls blood oxalate levels. Targeted disruption of murine NaS1 and Sat1 leads to hyposulfatemia and hypersulfaturia. Sat1 null mice also exhibit hyperoxalemia, hyperoxaluria, and calcium oxalate urolithiasis. NaS1 and Sat1 null mice also have other phenotypes that result due to changes in blood sulfate and oxalate levels. Experimental data indicate that NaS1 is essential for maintaining sulfate homeostasis, whereas Sat1 controls both sulfate and oxalate homeostasis in vivo.
Colored context cues can facilitate the ability to learn and to switch between multiple dynamical force fields
Authors: Addou Touria , Krouchev Nedialko , Kalaska John F.
Published: April 2011

We tested the efficacy of color context cues during adaptation to dynamic force fields. Four groups of human subjects performed elbow flexion/extension movements to move a cursor between targets on a monitor while encountering a resistive (Vr) or assistive (Va) viscous force field. They performed two training sets of 256 trials daily, for 10 days. The monitor background color changed (red, green) every four successful trials but provided different degrees of force field context information to each group. For the irrelevant-cue groups, the color changed every four trials, but one group encountered only the Va field and the other only the Vr field. For the reliable-cue group, the force field alternated between Va and Vr each time the monitor changed color (Vr, red; Va, green). For the unreliable-cue group, the force field changed between Va and Vr pseudorandomly at each color change. All subjects made increasingly stereotyped movements over 10 training days. Reliable-cue subjects typically learned the association between color cues and fields and began to make predictive changes in motor output at each color change during the first day. Their performance continued to improve over the remaining days. Unreliable-cue subjects also improved their performance across training days but developed a strategy of probing the nature of the field at each color change by emitting a default motor response and then adjusting their motor output in subsequent trials. These findings show that subjects can extract explicit and implicit information from color context cues during force field adaptation.
A Malignant Gastrointestinal Stromal Tumor of the Gallbladder Immunoreactive for PDGFRA and Negative for CD 117 Antigen (c-KIT)
Authors: Petrou Athanasios , Alexandrou Pari , Papalambros Alexandros , Saetta Angelica , Fragkou Paraskevi , Kontos Michalis , Brennan Nicholas , Manzelli Antonio , Bramis Kostantinos , Felekouras Evangelos
Published: April 2011

Gastrointestinal stromal tumors (GISTs) compose the largest category of well-recognized nonepithelial neoplasms of the gastrointestinal tract (GI). GISTs of the gallbladder are extremely rare tumors. Only four malignant, two benign and one GIST-like tumor of the gall bladder have ever been described. The four malignant GISTs were all positive for CD 117 antigen (c-kit). We present for the first time a malignant gastrointestinal stromal tumor of the gallbladder, immunoreactive for platelet-derived growth factor receptor alpha (PDGFRA) and negative for CD 117 antigen (c-KIT).
Theoretical Study of a Thermophysical Property of Molten Semiconductors
Authors: Aqra Fathi , Ayyad Ahmed
Published: April 2011

This paper deals with theoretical approach to surface tension of molten silicon and germanium, and contributes to this field, which is very important. A theoretical calculation for determining the surface tension of high-temperature semiconductor melts, such as molten silicon and germanium, in the temperature range 1687–1825 K and 1211–1400 K, respectively, is described. The calculated temperature-dependence surface tension data for both Si and Ge are expressed as and (mJ m−2), respectively. These values are in consistence with the reported experimental data (720–875 for Si and 560–632 mJ m−2 for Ge). The calculated surface tension for both elements decreases linearly with temperature.
Gradually Guiding Nursing Students through Their Capstone Course: Registered Nurse Preceptors Share Their Experiences
Authors: Martin David L. , Brewer M. Kathleen , Barr Nancy
Published: April 2011

Professional precepted immersion courses (capstone) have become the standard as a means to prepare senior nursing students to enter the workforce. Preceptors have a significant role in developing the student nurse, yet exactly how to prepare preceptors for this role has been an ongoing discussion. This qualitative inquiry explored the educational needs of clinical registered nurse (RN) preceptors who work directly with senior nursing students in a professional precepted immersion (capstone) course. A descriptive qualitative design was used to examine preceptors responses to a prepared set of questions about their educational needs. Results showed that preceptors have three distinct sets of learning needs: the need to know the expectations of their role, wanting to know how best to role model for the student, and knowing how to socialize the student into the profession of nursing. Overall, preceptors communicated their desire and commitment to doing the best job possible. They also clearly stated their expectation of faculty to have a physical presence on the nursing unit that included being proactive in resolving mismatches and exposing the student to the roles of provider of care, leader and manager of care, and member of profession.
Transluminal Angioplasty of Transplanted Renal Artery Stenosis: A Review of the Literature for Its Safety and Efficacy
Authors: Leonardou Polytimi , Gioldasi Sofia , Pappas Paris
Published: April 2011

Transplant renal artery stenosis (TRAS) is a well-known cause of posttransplant hypertension accompanied by possible graft dysfunction and is potentially curable when is diagnosed early. Colour Doppler Ultrasonography (CDU) is the screening procedure of choice in most studies whereas some centers employ Magnetic Resonance Angiography (MRA), if available. Although both CDU and MRA can arouse suspicion of disease in less symptomatic cases, angiographic techniques are essential for confirmation of TRAS. Percutaneous Transluminal Angioplasty (PTA) is a good and widespread therapeutic approach for the treatment of TRAS due to its acceptable complication rate and high technical success rate. The purpose of this paper is to assess the safety and efficacy of PTA in the treatment of TRAS, to compare the long-term outcomes between different reports, and to examine the role of PTA with stenting in inhibiting recurrence of the disease.
Effector Caspases and Leukemia
Authors: Lu Ying , Chen Guo-Qiang
Published: April 2011

Caspases, a family of aspartate-specific cysteine proteases, play a major role in apoptosis and a variety of physiological and pathological processes. Fourteen mammalian caspases have been identified and can be divided into two groups: inflammatory caspases and apoptotic caspases. Based on the structure and function, the apoptotic caspases are further grouped into initiator/apical caspases (caspase-2, -8, -9, and -10) and effector/executioner caspases (caspase-3, -6, and -7). In this paper, we discuss what we have learned about the role of individual effector caspase in mediating both apoptotic and nonapoptotic events, with special emphasis on leukemia-specific oncoproteins in relation to effector caspases.
High-Dose Chemotherapy with Autologous Hematopoietic Stem-Cell Rescue for Pediatric Brain Tumor Patients: A Single Institution Experience from UCLA
Authors: Panosyan Eduard H. , Ikeda Alan K. , Chang Vivian Y. , Laks Dan R. , Reeb Charles L. , Bowles La Vette , Lasky Joseph L. , Moore Theodore B.
Published: April 2011

Background. Dose-dependent response makes certain pediatric brain tumors appropriate targets for high-dose chemotherapy with autologous hematopoietic stem-cell rescue (HDCT-AHSCR).Methods. The clinical outcomes and toxicities were analyzed retrospectively for 18 consecutive patients ≤19 y/o treated with HDCT-AHSCR at UCLA (1999–2009).Results. Patients' median age was 2.3 years. Fourteen had primary and 4 recurrent tumors: 12 neural/embryonal (7 medulloblastomas, 4 primitive neuroectodermal tumors, and a pineoblastoma), 3 glial/mixed, and 3 germ cell tumors. Eight patients had initial gross-total and seven subtotal resections. HDCT mostly consisted of carboplatin and/or thiotepa ± etoposide (n=16). Nine patients underwent a single AHSCR and nine ≥3 tandems. Three-year progression-free and overall survival probabilities were 60.5% ± 16 and 69.3% ± 11.5. Ten patients with pre-AHSCR complete remissions were alive/disease-free, whereas 5 of 8 with measurable disease were deceased (median followup: 2.3 yrs). Nine of 13 survivors avoided radiation. Single AHSCR regimens had greater toxicity than ≥3 AHSCR (P<.01).Conclusion. HDCT-AHSCR has a definitive, though limited role for selected pediatric brain tumors with poor prognosis and pretransplant complete/partial remissions.
Safety and Pharmacokinetics of Motesanib in Combination with Panitumumab and Gemcitabine-Cisplatin in Patients with Advanced Cancer
Authors: Burris Howard , Stephenson Joe , Otterson Gregory A. , Stein Mark , McGreivy Jesse , Sun Yu-Nien , Ingram Megan , Ye Yining , Schwartzberg Lee S.
Published: April 2011

Purpose. The aim of this study was to assess the safety and tolerability of motesanib (an orally administered small-molecule antagonist of vascular endothelial growth factor receptors 1, 2, and 3, platelet-derived growth factor receptor, and Kit) when administered in combination with panitumumab, gemcitabine, and cisplatin.Methods. This was an open-label, multicenter phase 1b study in patients with advanced solid tumors with an ECOG performance status ≤1 and for whom a gemcitabine/cisplatin regimen was indicated. Patients received motesanib (0 mg [control], 50 mg once daily [QD], 75 mg QD, 100 mg QD, 125 mg QD, or 75 mg twice daily [BID]) with panitumumab (9 mg/kg), gemcitabine (1250 mg/m2) and cisplatin (75 mg/m2) in 21-day cycles. The primary endpoint was the incidence of dose-limiting toxicities (DLTs).Results. Forty-one patients were enrolled and received treatment (including 8 control patients). One of eight patients in the 50 mg QD cohort and 5/11 patients in the 125 mg QD cohort experienced DLTs. The maximum tolerated dose was established as 100 mg QD. Among patients who received motesanib (n=33), 29 had motesanib-related adverse events. Fourteen patients had serious motesanib-related events. Ten patients had motesanib-related venous thromboembolic events and three had motesanib-related arterial thromboembolic events, two of which were considered serious. One patient had a complete response and nine had partial responses as their best objective response.Conclusions. The combination of motesanib, panitumumab, and gemcitabine/cisplatin could not be administered consistently and, at the described doses and schedule, may be intolerable. However, encouraging antitumor activity was noted in some cases.
Tyrosine Phosphorylation-Mediated Signaling Pathways in Dictyostelium
Authors: Sun Tong , Kim Leung
Published: April 2011

While studies on metazoan cell proliferation, cell differentiation, and cytokine signaling laid the foundation of the current paradigms of tyrosine kinase signaling, similar studies using lower eukaryotes have provided invaluable insight for the understanding of mammalian pathways, such as Wnt and STAT pathways. Dictyostelium is one of the leading lower eukaryotic model systems where stress-induced cellular responses, Wnt-like pathways, and STAT-mediated pathways are well investigated. These Dictyostelium pathways will be reviewed together with their mammalian counterparts to facilitate the comparative understanding of these variant and noncanonical pathways.
The Domestic Cat as a Large Animal Model for Characterization of Disease and Therapeutic Intervention in Hereditary Retinal Blindness
Authors: Narfström Kristina , Holland Deckman Koren , Menotti-Raymond Marilyn
Published: April 2011

Large mammals, including canids and felids, are affected by spontaneously occurring hereditary retinal diseases with similarities to those of humans. The large mammal models may be used for thorough clinical characterization of disease processes, understanding the effects of specific mutations, elucidation of disease mechanisms, and for development of therapeutic intervention. Two well-characterized feline models are addressed in this paper. The first model is the autosomal recessive, slowly progressive, late-onset, rod-cone degenerative disease caused by a mutation in theCEP290gene. The second model addressed in this paper is the autosomal dominant early onset rod cone dysplasia, putatively caused by the mutation found in theCRXgene. Therapeutic trials have been performed mainly in the former type including stem cell therapy, retinal transplantation, and development of ocular prosthetics. Domestic cats, having large human-like eyes with comparable spontaneous retinal diseases, are also considered useful for gene replacement therapy, thus functioning as effective model systems for further research.
Intrinsic Anticancer Drug Resistance of Malignant Melanoma Cells Is Abrogated by IFN-β and Valproic Acid
Authors: Roos Wynand P. , Jöst Eva , Belohlavek Christina , Nagel Georg , Fritz Gerhard , Kaina Bernd
Published: April 2011

Malignant melanoma, once metastasized, has a dismal prognosis because of intrinsic resistance to anticancer drugs. First-line therapy includes the methylating agents dacarbazine and temozolomide. Although DNA mismatch repair and O6-methylguanine (O6MeG)-DNA methyltransferase (MGMT) are key determinants of cellular resistance to these drugs, there is no correlation between these markers and the therapeutic response in melanoma, indicating as yet unknown mechanisms of drug resistance. We show that in malignant melanoma cells with wild-type p53, the temozolomide-induced DNA damage O6MeG triggers upregulation of the Fas/CD95/Apo-1 receptor without activating the apoptosis cascade. This is due to silencing of procaspase-8. A single treatment with IFN-β reactivated procaspase-8 and sensitized melanoma cells to temozolomide. The key role of procaspase-8 in melanoma cell sensitization was verified by experiments in which the death receptor pathway was blocked by expression of dominant-negative FADD, siRNA knockdown of procaspase-8, or stimulation with Fas/CD95/Apo-1 activating antibody. The expression of procaspase-8 could further be enhanced by additional pretreatment with the histone deacetylase inhibitor valproic acid (VPA), which together with IFN-β caused significant sensitization of melanoma cells in vitro. Sensitization of melanoma cells to temozolomide by IFN-β and VPA was also shown in a xenograft mouse model. The data provide a plausible explanation why therapy of malignant melanomas with alkylating anticancer drugs failed even in trials where the repair of the critical toxic lesion O6MeG was blocked by MGMT inhibitors and suggest approaches to abrogate intrinsic drug resistance by IFN and VPA-mediated reactivation of the death receptor pathway. Cancer Res; 71(12); 4150–60. ©2011 AACR.
The Sensitivity of [11C]Choline PET/CT to Localize Prostate Cancer Depends on the Tumor Configuration
Authors: Souvatzoglou Michael , Weirich Gregor , Schwarzenboeck Sarah , Maurer Tobias , Schuster Tibor , Bundschuh Ralph Alexander , Eiber Matthias , Herrmann Ken , Kuebler Hubert , Wester Hans Juergen , Hoefler Heinz , Gschwend Juergen , Schwaiger Markus , Treiber Uwe , Krause Bernd Joachim
Published: April 2011

Purpose: To evaluate the dependency of the sensitivity of [11C]choline positron emission tomography/computed tomography (PET/CT) for detecting and localizing primary prostate cancer (PCa) on tumor configuration in the histologic specimen.

Experimental Design: Forty-three patients with biopsy-proven PCa were included. They underwent radical prostatectomy within 31 days after [11C]choline PET/CT. The transaxial image slices and the histologic specimens were analyzed by comparing the respective slices. Maximum standardized uptake values (SUVmax) were calculated in each segment and correlated with histopathology. The tumor configuration in the histologic specimen was grouped as: I, unifocal; II, multifocal; III, rind-like shaped; IV, size <5 mm. Data analysis included the investigation of detection of PCa by SUVmax, the assessment of the influence of potential contributing factors on tumor prediction, and the evaluation of whether SUV could discriminate cancer tissue from benign prostate hyperplasia (BPH), prostatitis, HGPIN (high-grade prostate intraepithelial neoplasm), or normal prostate tissue. General estimation equation models were used for statistical analysis.

Results: Tumor configuration in histology was classified as I in 21 patients, as II in 9, as III in 5, and as IV in 8. The prostate segment involved by cancer is identified in 79% of the patients. SUVmax was located in the same side of the prostate in 95% of patients. Tumor configuration was the only factor significantly negatively influencing tumor prediction (P < 0.001). PCa-SUVmax (median SUVmax = 4.9) was not significantly different from BPH-SUV (median SUVmax = 4.5) and prostatitis-SUV (median SUVmax = 3.9), P = 0.102 and P = 0.054, respectively.

Conclusions: The detection and localization of PCa in the prostate with [11C]choline PET/CT is impaired by tumor configuration. Additionally, in our patient population, PCa tissue could not be distinguished from benign pathologies in the prostate. Clin Cancer Res; 17(11); 3751–9. ©2011 AACR.