bluuebunny/crossref_metadata_2025 huggingface dataset:
Hormonal stress in adolescent female volleyball players
Authors: Cruz-Márquez J C , Cruz-Campos J C , Cruz-Campos A , Cueto-Martín MªB , García-Jiménez Mª
Published: April 2011

Background

Catecholamine and cortisol are markers of hormonal stress in young female athletes and may indicate adaptation to an active lifestyle and sports activity.

Objective

To discover if volleyball training produces changes in catecholamine and cortisol.

Design

We performed a prospective study during a sports season (September–May) with monthly measurements of catecholamine and cortisol in urine collected over a 24-h period, on a rest day and between days 5 and 25 of the menstrual cycle.

Setting and participants

24 women (mean age 17±0.5 years; height: 172.8±4.7 cm; weight: 60.7±3.8 kg), volleyball players from two youth teams competing regionally (years of training: 3±0.4) and 24 sedentary women (ages: 17±0.9; height: 161±5.8 cm; weight: 58±5.6) selected from the high school. Participating teams: Ranked first and second last season. All players who started the study completed it. None of the participants were taking contraceptives or receiving hormonal treatments.

Interventions

The players trained four days/week (an average of 8.3 h/week) and played 24 official matches. The sedentary women attended a physical education class 2 days/week (2 h/week), along with the players. Independent Variables: exercise, volleyball training and healthy lifestyle. Dependent Variables: urinary catecholamines and cortisol.

Results

The sedentary participants had higher levels of epinephrine, norepinephrine, dopamine, metanephrine, normetanephrine and cortisol than the women athletes (p<0.05). Higher levels of catecholamines were recorded in September and October in both groups, whereas cortisol levels were higher in April and May. All levels were in normal ranges. There were no significant differences between players based on minutes of competition.

Conclusions

Playing volleyball and following a healthy lifestyle do not increase levels of catecholamines and cortisol in well-trained adolescent girls.
The effect of player position on patellar tendinopathy in volleyball
Authors: Mahieu N , De Ridder R , Reynaert L , Strubbe K , Poppe W , Cools A , Roosen P
Published: April 2011

Background

This pilot study is the first to investigate the role of player position on the development of patellar tendinopathy (PT) in competitive volleyball players.

Objective

The objective is to identify intrinsic risk factors depending on player position for developing PT.

Design

Retrospective design.

Setting

Eight male national volleyball teams participated in this study. They were tested at the beginning of the season 2009–2010.

Participants

A total of 71 male players were included. For each player the position on the field was registered. By means of questionnaires, the participants injury history was documented.

Assessment of risk factors

Anthropometrical data, muscle strength, muscle length and landing strategies were assessed.

Main outcome measurements

The strength of the hip muscles was measured with a hand-held dynamometer. Muscle length of gastrocnemius, soleus, hamstrings and quadriceps was determined by means of a plurimeter. A 2D video analyses was made of a vertical jump. Knee flexion angle, Q-angle and Ankle dorsiflexion angle during the landing were calculated.

Results

The incidence of PT is higher in outside hitters (11%) and middle blockers (12.1%) than opposites (3.2%), setters (4.8%) and libero's (6%). When taking into account the players with a history of PT, the libero has a significant higher body mass, a higher body mass index and a shorter length of quadriceps. The setter has a lower hip flexion strength. The middle blocker has a higher ankle dorsiflexion ROM and lower hip exorotation strength. The outside hitter has a smaller Q-angle when standing, a higher ankle dorsiflexion ROM, a longer soleus length and a smaller hip flexion strength.

Conclusions

This study indicates that other factors may play in the development of PT depending on player position. However, the results in this study are preliminary and needs to be confirmed by future research.
The TOPGAME-study: effectiveness of extracorporeal shockwave therapy in jumping athletes with patellar tendinopathy
Authors: Zwerver J , van den Akker-Scheek I , Hartgens F , van de Worp H , Verhagen E , Diercks R L
Published: April 2011

Background

Patellar tendinopathy is a common and often difficult-to-treat knee injury in jumping athletes. Extracorporeal shockwave therapy (ESWT) appears to be a promising treatment but its effectiveness has not been studied in athletes who keep playing sports.

Objective

To determine the effectiveness of ESWT in athletes with patellar tendinopathy with short duration of symptoms who are still in training and competition.

Design

Multicenter two armed randomized controlled trial with blinded participants and outcome assessors.

Setting and participants

Non-elite athletes aged 18–35. 57 volleyball, one handball and four basketball players with patellar tendinopathy (symptoms 3–12 months). Of these, 57 completed the study Intervention of three focused ESWT treatments (or placebo) at a weekly interval.

Main outcome measurements

VISA-P score at 1, 12 and 22 weeks after the final treatment, when athletes were still in competition.

Results

The mean VISA-P scores before and after treatment are summarized below. There was a significant effect for time (p<0.01) but no effect for treatment×time (p=0.82). One week after treatment more patients in the treatment group compared to patients in the placebo group evaluated the treatment as being beneficial (67% vs 37%, χ2=5.00 p=0.03).

Mean VISA-P scoresESWTPlaceboBefore59.4±11.762.4±13.4After 1 week66.8±16.266.3±19.0After 12 week66.7±17.568.9±20.3After 22 week70.5±18.972.7±8.0

Conclusions

There was no effect of ESWT treatment protocol on the course of symptomatic patellar tendinopathy in jumping athletes who continued to train and compete.
Dependence of human maximum vertical counter-movement jump height on activation sequence of the biarticular muscles
Authors: Bračič M , Supej M , Matjačić Z
Published: April 2011

Background

When executing vertical jumps a noticeable problem transpires in the efficient transfer of rotational energies of the trunk and the lower body segments into the largest possible vertical velocity. In the transfer of energy, the biarticular muscles rectus femoris (RF) and gastrocnemius (GAS) play an important (Bobbert & Van Ingen Schenau, 19881; Gregoireet al., 19842).

Objective

The hypothesis of the study were that athletes with greater maximum vertical counter movement jump height have better energy efficiency of two-legged jumps due to correct activation sequence of the biarticular muscles RF and GAS, which ensure a transfer of rotational kinetic energy between body segments following a proximal to distal principle.

Setting and participants

12 male elite athletes (age: 22.41±3.39 years; height 177.58±6.86 cm, body mass 74.92±5.23 kg) performed two-leg counter movement jumps (CMJ).

Methods

Eight camcorders with a frequency of 200 Hz were used for the 3D kinematic measurements of CMJ. The ground reaction forces of jumps were measured unilaterally and bilaterally using two independent and synchronized force platforms. The maximal jump height of the centre of body's mass (HCM) was determined by the time integration (tfl) of the vertical force (F=Fz-mg) signal: HCM=tfl2•g•8–1. Electromyographical data of the time to peak EMG (TTPEMG) from biarticular RF and GAS in concentric phase of the jump were analyzed.

Results

The comparison between two groups showed that athletes with greater maximum vertical counter movement jump height (group_1: 64.10±5.08 cm vs group_2: 56.41±3.88 cm; p<0.05) have different activation sequence of the biarticular RF and GAS (group_1; TTPEMG_RF=110.53±20.11 ms, TTPEMG_GAS=137.88±22.43 ms vs group_2; TTPEMG_RF=143.56 ±32.23 ms, TTPEMG_GAS=84.81±25.67 ms; p<0.05) which indirectly implicate that the transfer of rotational kinetic energy between body segments follows a proximal to distal principle.

Conclusions

It is concluded that correct activation sequence of the RF and GAS is essential in the execution of vertical counter movement jump.
Possible differences in hematological status between junior and elite female volleyball players
Authors: Milić R , Dopsaj M
Published: April 2011

Background

Iron deficiency anaemia and iron deficiency without anemia have debilitating effects on athletic performance due to decreased work capacity and impaired cognition.

Objective

The main goal of this research was to identify possible differences in haematological status between junior and elite female volleyball players.

Subjects

38 female volleyball players belonging to Junior (J) and Elite (E) Serbian and Slovenian national volleyball teams were recruited for the study. The average age of 18 E athletes was 23.8±2.9 years, body height 177.9±9.5 cm, body weight 68.9±7.9 kg and their body mass index (BMI) was 21.7±0.9 kg/m2. Training experience was 12.0±3.2 years and training load in the last micro cycle was 18.4±1.2 h per week. The age of 20 J athletes was 16.9±1.2 years, body height 177.4±5.4 cm, body weight 65.2±3.5 kg and the mean BMI was 20.8±1.4 kg/m2. Training experience was 6.4±1.4 years and training load in the last micro cycle was 15.7±1.6 h per week.

Methods

Blood collection was performed between 7 and 8 am at the beginning of the pre-competitive training period after a 12-h overnight fast. Venous blood was collected into evacuated tubes (Vacutainer, Becton Dickinson, USA) from the antecubital vein with minimal stasis. Blood analyses were performed on the instrument Advia 120 (Siemens, Tarrytown, USA), appropriately calibrated and controlled. 14 parameters were taken into account: RBC, Hb, Hct, Ret_abs and Ret (%), erythrocyte index (MCV, MCH, MCHC), RDW, TIBC, iron, ferritin, transferin saturation, soluble transferring receptor (s-TfR). Descriptive statistics and multivariate analysis of variance were employed to investigate differences between the two groups. The result was considered significant when p<0.05. SPSS 17.0 statistical package were used.

Results

Statistical analysis showed significant differences (p<0.05) between (J) and (E) female volleyball players in five parameters from performed blood analyses (RBC, Hct, MCHC, TIBC, ferritin) with lower absolute values in the elite group.

Conclusions

The current study is the first to demonstrate differences in the haematological status between junior and elite female volleyball players, the underlying reasons for which may include differences in training experience and training load.
Intrinsic risk factors for sport injuries in female volleyball
Authors: Sattler T
Published: April 2011

Background/objective

To investigate the incidence and injury mechanism as well as intrinsic risk factors for acute sports injuries in female volleyball.

Design

Prospective epidemiological study.

Setting and participants

174 female volleyball players from Slovenian Divisions I and II were prospectively monitored during 2007–2008 season.

Methods

All injuries were prospectively documented by team coaches. Prior to the season all players underwent the following tests: anthropometry, sit and reach test, isokinetic strength testing of the knee and shoulder, postural stability testing and vertical jump testing. Main outcome measure was injury incidence; binary logistic regression was used afterwards in order to evaluate the role of different parameters from functional testing on injury occurrence.

Results

The overall incidence of injuries for the females was 0.35±0.19 per 1000 h of volleyball played. The incidence of injuries in a game situation was higher than in practice (2.10±1.06 vs 0.42±0.24) The most frequent injury was acute ankle sprain 1.45 (1.98), followed by knee injury 0.69 (1.34). Majority of injuries occurred during the competition season (81.4%), in the middle of training (25.58%) or during a game (25.58%). Most injuries occurred during landing (41.4%). Risk factor analysis revealed that previous injury is an important risk factor for acute knee injuries and ankle sprains. Low hamstring quadriceps ratio was related with ankle sprains, while quadriceps strength asymmetry was related to acute knee injuries.

Conclusions

The results of our study suggest that isokinetic strength testing in previously injured female volleyball players could identify players with increased risk for acute knee injuries and ankle sprains.
Epidemiology of the injuries of the locomotor system in elite volleyball players
Authors: Aido R , Massada M , Leitão N , Magalhães C , Puga N
Published: April 2011

Background

The epidemiological study is an important tool in the understanding and development of any medical field. In Sports Medicine highlights their importance in the development of preventive strategies with the ultimate goal of protecting and enhancing the performance of athletes.

Objective

This observational study has the aim to identify the prevalence, incidence, aetiology, severity and anatomical location of injuries of the locomotor system occurred in volleyball elite players.

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 during 4 months. All the injuries were recorded and reported with their clinical diagnosis.

Results

During the study, 55 injuries were detected with an incidence rate of 6.11 injuries per athlete per 1000 h of sporting activity. An higher incidence of injuries was observed during games when compared with the training sessions (10.11 vs 5.56). The 55 lesions were diagnosed in 18 athletes (90.00%) who comprised the study, noting the prevalence of overuse injuries (72.73%). The anatomical segment most affected was the lower limb (45.54%). Lower limb anatomic area with highest number of injuries was the knee and leg (27.27%). Muscular injuries (38.18%) and tendinopathys (34.54%) were the most frequent injuries reported. There was a predominance of lesions in the dominant member (64.86%). In eight players (40.00%) recurrence of previous injuries was diagnosed. The greatest number of lesions was considered of mild (58.18%) or moderate (34.54%) severity. The analysis between the injuries and the athlete's position stated that the opposites were the most affected players. The first month of sport activity was the period with more injuries recorded.

Conclusions

The results reported in this study show a predominance of overuse and recurrent injuries in elite volleyball athletes. These finding are consistent with previously conducted epidemiological records.
The relationship between patellar tendinopathy risk factors and ground reaction forces during cross-over block jump landings
Authors: Janssen I , Steele J R , Munro B J , Brown N A T
Published: April 2011

Background

Overuse knee injuries, such as patellar tendinopathy, are one of the most prevalent and frequent injuries in volleyball with up to 50% of male indoor volleyball players sustaining this injury in their careers.

Objective

The aim of this research was to examine the intrinsic and extrinsic risk factors associated with patellar tendinopathy including muscle flexibility, muscle strength, vertical jump, and their relationship to vertical ground reaction forces (vGRF) during cross-over block jump landings.

Design

Structural alignment, lower limb flexibility, and muscle strength assessed were measured for each participant who then performed five trials of a cross-over step block. vGRF (vGRF: 1500 Hz; Kistler) were collected for takeoff and landing.

Setting

A portable volleyball net was used to simulate a typical and realistic volleyball condition in a biomechanics laboratory. A standard volleyball was mounted on a post and used as a target.

Participants

Elite male (EM) (N=10), sub-elite male (SEM) (N=10), and sub-elite female (N=10) volleyball players with no existing knee joint injury or history of lower limb surgery participated in this study.

Main outcome measurements

Magnitudes of and correlations among risk factor measures and peak vGRF.

Results

Gender differences were observed with SEM displaying significantly smaller Q-angle (p=0.04), greater strength (p=0.00), and maximal jump height (p=0.00) than SEF. EM displayed passive greater hip extension (p=0.01) and trunk flexion (p=0.05), and significantly greater strength in their non-dominant quadriceps (p=0.01) than SEM. SEM generated significantly higher vGRF compared to SEF. Significant negative correlations were found between vGRF and Q-angle and gastrocnemius flexibility for SEF but not SEM or EM.

Conclusions

The results of this study may provide further insight why and which volleyball athletes may be prone to developing overuse knee injuries.
Developing an injury tracking software system specific for volleyball: a case example
Authors: Yasher K R , Liller K , Wong S , Jang S , Morris B J , Konin J G
Published: April 2011

Background

Injury tracking systems are becoming increasingly popular in the realm of sports medicine. Identifying the prevalence and types of injuries can contribute to the identification of risk factors associated with sport specific injuries, as well as lead to the development of injury prevention programs, educational material, rule changes, and improved protective equipment.

Objective

To describe the process of creating an injury tracking system for volleyball in an effort to track variables associated with injury patterns.

Design

A software program containing over 1000variables was developed by certified athletic trainers and public health experts. Variables included demographic information, environmental factors, and sport specific movements. Standardized definitions (ie, ‘injury’) were established and pilot tested for reliability and validity purposes using internally developed case studies.

Setting

Data was collected via a web-based software program through the university academic program.

Participants

Participants included female volleyball players between 14–18 years of age.

Results

Analysis of the results identified common injuries associated with volleyball and their associated mechanisms. These findings directly led to the implementation of educational programs designed to prevent such injuries from occurring in the future. Furthermore, internal assessments of the program development noted the requirement of frequent variable modifications, standardized training necessities, and ongoing discussion to assure accurate data input.

Conclusions

The development of an injury tracking system specific to volleyball requires time, funding, ongoing re-evaluation, standardized terms, training for data collectors, and plans for implementing the findings into practical information for coaches, players, parents, and health care providers. When developed successfully, the information collected can prove to be valuable.
The relationship between different adaptational changes and injury in the dominant shoulder of female overhead athletes
Authors: Tonin K , Stražar K , Vidmar G , Tomšič I , Burger H
Published: April 2011

Background

Adaptational changes (gleno-humeral internal rotation deficit – GIRD, SICK scapula signs and muscular imbalances) develop in the dominant shoulder of overhead athletes.

Objective

To evaluate the incidence and the correlation between different adaptational changes and injury in the dominant shoulder. To evaluate the effect of (a)symmetrical hand-use on the development of adaptational changes and shoulder injury.

Design

Observational cross-sectional correlational study.

Setting and participants

36 highly competitive female overhead athletes (21 handball players, 15 volleyball players), competing in Middle European volleyball league, EHF women's champions league and Slovene National leagues and National cups. Players were divided into two groups by the symmetry of hand-use.

Interventions

Participants completed a self-reported shoulder history questionnaire. Complete clinical examination of the shoulders was performed, including passive internal (IR) and external rotation (ER), SICK scapula and GIRD evaluation. Isokinetic testing of IR and ER was performed in concentric (c) and eccentric (e) modes at two testing speeds (60°/s, 150°/s). Fatiguability of IR and ER was measured. Stability spiking (eER/cIR) and cocking ratios (eIR/cER) were calculated.

Results

All participants had decreased IR and increased ER ROM in dominant shoulders (p>0.001). Average GIRD was 20.6°, greater GIRD correlated with higher cIR peak torques (p=0.008). Dominant hand eER peak torques were lower, hence the spiking ratios were lower (p=0.015 and p=0.002). Players with previous injury showed more scapular abduction, increased ER and lower cocking ratios (p=0.04, p=0.036, p=0.06). Players with asymmetrical hand-use showed higher fatiguability of IR and ER (p=0.019, p=0.01).

Conclusions

Static and dynamic adaptational changes are found in the dominant shoulder and are positively correlated to each other and to history of injury. Hitters and throwers fatigue more. Preventive shoulder training is crucial for injury prevention of highly competitive overhead athletes with existing adaptational changes.
Anti-doping activites of volleyball in Japan
Authors: Hashimoto Y , Yamashita T , Hamu Y , Hayashi M
Published: April 2011

Background

Anti-doping activities are necessary for justice and fairness in sports. In and out of competition doping tests are now mainly responsible for anti-doping activities.

Objective

To clarify the anti-doping activities in Japan in recent years.

Design, setting, and participants

The object of the investigation is to summarize the doping tests performed after the volleyball games in Japan between 2006–2009. The anti-doping activities were mainly in the responsibility of the anti-doping subcommittee of the Japan Volleyball Association. This subcommittee is doing the coordination of drug testing in international games and domestic games. The competitions in which the doping tests were done were international games (Volleyball World Championship (VWC), World Cup (WC), World Grand Prix (WGP), Grand Champions Cup (GCC), and final preliminary qualifying contests (OQT) for the Olympic Games), and domestic games (V League, Emperor's Cup, and national constitution). Undergo doping test athletes were randomly chosen by lot from among all the participating players of the competition. Out-of-competition testing was based on the information ADAMS and whereabouts. All tests were urine, blood tests were not performed. All samples were carried to Mitsubishi Chemical Medience that was the only WADA official recognition analyzing facilities in Japan.

Results

The number of samples increased every year, and the out of competition testing became a higher percentage of the total number of samples. The number of tests each year are as follows.

Conclusions

There are many international games, and are many chances of the doping tests in Japan. Recently, the number of OOCT is increased. The most import ant thing is to raise awareness of anti-doping to individual players through the tests and the educational activities.

ICTOOCT2006 V-league+VWC201172007 V-league+WC101532008 V-league+OQT+WGP1321042009 V-league+WGP+GCC114Unpublished
The effect of progressive endurance-strength training and electrical stimulation on muscle strength and surface electromyography parameters in volleyball players with infraspinatus syndrome
Authors: Shavandi N , Hoseini R S
Published: April 2011

Background

Infraspinatus syndrome is a condition of painless weakness and atrophy of the infraspinatus muscle that results from suprascapular neuropathy.

Objectives

Survey the effects of a short term progressive endurance-strength training program and electrical stimulation on elite volleyball players with infraspinatus syndrome.

Design

Randomized clinical trial with control group.

Setting and participants

National team players.

Participants

12 volleyball players with Infraspinatus syndrome were randomly divided to two groups: progressive endurance-strength training (six persons) and electrical stimulation (six persons). 20 healthy players were also used as a control group.

Intervention

Therapeutic exercises and electrical stimulation were performed for 8 weeks in both intervention groups.

Main outcomes

Surface electromyography of infraspinatus and tress minor muscles and maximal isometric strength of external rotator muscles before and after interventions.

Results

32 players were studied in three groups: progressive endurance-strength (6 persons, age), electrical stimulation (six persons) and a control group (20 persons, age 25/1±4/2, height 187/7±3/9, weight 75/6±7/1, sport history 9±3/8 and national team history 3/9±2/3). After 8 weeks, maximal isometric strength of the external rotators in both experimental groups was increased significantly, but there were no significant changes observed in IEMG and RMSEMG.

Conclusions

Progressive endurance-strength training and electrical stimulation can result in an increase of maximal isometric strength of the shoulder external rotator muscles. But both therapeutic methods have no effect on electromyograghic parameters in infraspinatus and tress minor muscles. It seems that we can't use surface electromyography for detecting the effect of these protocols on above the muscles.
Study of proprioceptive function in professional volleyball athletes with atrophy of the infraspinatus
Authors: Salles J I , Alves H , Amaral M V , Cagy M , Cunha-Cruz V , Piedade R , Ribeiro P
Published: April 2011

Background

The isolated atrophy of the infraspinatus muscle is an uncommon clinical alteration, generally secondary to the selective lesion of the suprascapular nerve related to sport activities, especially in professional volleyball players. The lesion of the suprascapular nerve can cause kinesthetic deficits. The assessment of kinesthesia is determined by the ability to detect joint movement and has been traditionally conducted by measuring the Threshold of Perception of Passive Motion (TPPM).

Objective

The goal of the present study was to compare the TPPM among a group of healthy individuals (control group), a group of World League volleyball players with atrophy of the infraspinatus muscle on the dominant side, and group of athletes with no shoulder pathologies.

Design, setting and participants

Observational study at a controlled research laboratory at the Brazilian Volleyball Training Center (CDV – Saquarema). 12 healthy non-athlete controls, 12 athletes with atrophy of the infraspinatus muscle, and 12 athletes without the atrophy.

Interventions

A proprioception-testing device passively moved the shoulder and participants were instructed to respond as soon as movement was detected (TPPM) by pressing a button-switch. EEG and electromyographic (EMG) activities were recorded simultaneously. Response latency was established as the delay between the stimulus (movement) and the response (button press). The time-frequency dynamics of the EEG was analyzed.

Results

An analysis of variance indicated a significant latency reduction (p<0.000) in the group of athletes without the atrophy when compared both to the group of athletes with the atrophy and to the control group. Furthermore, distinct patterns of cortical activity were observed in the three experimental groups.

Conclusions

The results suggest that systematically trained motor abilities, as well as the atrophy of the infraspinatus muscle, change the cortical representation of the different stages of proprioceptive information processing and, ultimately, the cortical representation of the TPPM.
Risk factors for patellar tendinopathy in volleyball players: a cross-sectional study
Authors: van der Worp H , van Ark M , Zwerver J , van den Akker-Scheek I
Published: April 2011

Background

Patellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. Findings are conflicting though, and most research is conducted on elite athletes.

Objective

Aim of the current study is to determine risk factors for PT in a large representative sample of volleyball players.

Design

Cross-sectional study using an online questionnaire.

Setting

Volleyball players of all playing levels.

Participants

All volleyball players between ages 18 and 35 years from the Dutch Volleyball Association were invited to complete the questionnaire (n=7750). 1561 volleyball players completed the questionnaire.

Assessment of risk factors

The following independent variables were collected: Gender, age, body mass index, waist-to-hip ratio, years playing volleyball, hours of training during the last week, number of games during the last month, average hours of other sports per week, training increase compared to last year, playing surface, playing level and playing position.

Main outcome measurements

Presence of symptomatic tendinopathy was the dependent variable.

Results

Being male (OR=2.1) and playing at the national level (OR=2.1) were risk factors for PT in volleyball players. Also players that play as outside hitter (OR=2.3) or middle blocker/hitter (OR=2.8) are at a greater risk for PT than those who play as setter.

Conclusions

Several potential risk factors for PT were identified. Volleyball players that play as outside hitter or middle block/hitter have the highest odds for PT. Therefore, changing playing position to libero/opposite hitter or setter may be an option in volleyball players with PT.
A parallel comparison of T-cell clonality assessment between an in-house PCR assay and the BIOMED-2 assay leading to an efficient and cost-effective strategy
Authors: Kuo Szu-Yin , Liu Hongxiang , Liao Yung-Liang , Chang Sheng-Tsung , Hsieh Yen-Chuan , Bandoh Betty Angela Nuako , Du Ming-Qing , Chuang Shih-Sung
Published: April 2011

Aims

Diagnosis of T-cell lymphoproliferation is sometimes challenging, and in certain instances pathologists rely heavily on the clonality assessment results of T-cell receptor (TCR) gene rearrangement (TCR-GR). Many investigators have designed various in-house primer sets for PCR-based study targeting different loci of TCR genes. In recent years, the commercial BIOMED-2 protocols have become available. The in-house primers are very cheap while the BIOMED-2 primers are expensive. This parallel study aimed to compare the sensitivity of the in-houseTCRGprimers (two reactions) and the BIOMED-2 TCR primers (six reactions) in an attempt to develop a sensitive and cost-effective strategy for TCR-GR assessment.

Methods

PCR-based analysis was performed on 69 samples of T-lineage neoplasms including 60 formalin-fixed paraffin-embedded (FFPE) tissues, 5 samples from peripheral blood (PB) and 4 samples from bone marrow (BM) aspirate.

Results

Forty-seven (78%) FFPE and all PB or BM aspirate samples yielded control DNA products suitable for clonality assessment including 4 precursor and 50 mature T-cell neoplasms. The detection rates of clonal TCR-GR were 63% (34/54) by the two in-houseTCRGprimers, 85% (46/54) by all six BIOMED-2 reactions, 91% (49/54) by combining the in-house and BIOMED-2TCRGreactions and 94% (51/54) by combining the in-house and all BIOMED-2 reactions. By using the in-house and BIOMED-2TCRGreactions with a total of four tubes, clonal TCR-GR was detected in 91% of the cases. The reagent cost for this combination was one-third of that for the six BIOMED-2 reactions and the detection rate was also higher than the latter alone (91% vs 85%).

Conclusions

As the in-house primers were custom made and are much cheaper than the commercial kits, the authors concluded that this four-tube strategy was cost-effective and efficient for TCR-GR clonality assessment.
A NOTE ON NONSINGULAR CYCLIC UNIVERSES IN THE DEFORMED HOŘAVA–LIFSHITZ GRAVITY
Authors: SON EDWIN J. , KIM WONTAE
Published: April 2011

We perform the phase space analysis in terms of the linearization technique in the Hořava–Lifshitz gravity with the softly broken detailed balance condition. It can be shown that the bouncing universe appears only for the positive spatial curvature of k = +1, and it is possible to obtain oscillating universe with the help of the negative dark radiation and the negative cosmological constant.
STUDY OF THE RESISTIVITY IN A CHANNEL WITH DEPHASED RIPPLES
Authors: HERRERA-GONZÁLEZ IVÁN F. , ARROYO-CORREA GABRIEL , MENDOZA-SUÁREZ ALBERTO , TUTUTI EDUARDO S.
Published: April 2011

We study the transport properties of classical particles in the ballistic regime trapped in a two-dimensional channel with dephased ripple boundaries. By taking into account small ripple amplitudes, an analytical approximate expression for the classical resistivity is obtained. We show that the resistivity can be increased considerably by dephasing the walls of the channel. Our results are compared with those obtained for a channel composed of flat and sinusoidal boundaries.
BRIDGE BETWEEN THE HYPERCHAOTIC LORENZ SYSTEM AND THE HYPERCHAOTIC CHEN SYSTEM
Authors: MA CHAO , WANG XINGYUAN
Published: April 2011

This paper presents a novel unified hyperchaotic system that contains the hyperchaotic Lorenz system and the hyperchaotic Chen system as two dual systems at the two extremes of its parameter spectrum. The new system is hyperchaotic over almost the whole range of the system parameter and continuously transfers from the hyperchaotic Lorenz system to the hyperchaotic Chen system. The new findings are not only demonstrated by computer simulations but also verified with bifurcation analysis, Lyapunov exponents and Lyapunov dimension.
N-SOLITON-LIKE SOLUTIONS AND BÄCKLUND TRANSFORMATIONS FOR A NON-ISOSPECTRAL AND VARIABLE-COEFFICIENT MODIFIED KORTEWEG-DE VRIES EQUATION
Authors: FENG QIAN , GAO YI-TIAN , MENG XIANG-HUA , YU XIN , SUN ZHI-YUAN , XU TAO , TIAN BO
Published: April 2011

A non-isospectral and variable-coefficient modified Korteweg–de Vries (mKdV) equation is investigated in this paper. Starting from the Ablowitz–Kaup–Newell–Segur procedure, the Lax pair is established and the Bäcklund transformation in original variables is also derived. By a dependent variable transformation, the non-isospectral and variable-coefficient mKdV equation is transformed into bilinear equations, by virtue of which the N-soliton-like solution is obtained. In addition, the bilinear Bäcklund transformation gives a one-soliton-like solution from a vacuum one. Furthermore, the N-soliton-like solution in the Wronskian form is constructed and verified via the Wronskian technique.
EFFECT OF TORSION ANGLE IN 4,4′-BIPHENYLDITHIOL FUNCTIONALIZED MOLECULAR JUNCTION
Authors: XIA CAI-JUAN , FANG CHANG-FENG , ZHAO PENG , LIU DE-SHENG
Published: April 2011

Based on nonequilibrium Green's function and first-principles calculations, we investigate the electronic transport properties of 4,4′-biphenyldithiol functionalized molecular junction with different torsion angles between two phenyl rings. Numerical results show that torsion angle plays an important role in the conducting behavior of molecular junction. By changing the torsion angle, molecule can exhibit a switching behavior. Especially, when the molecule is functionalized with NO 2 side group, it will perform a molecular memory effect. Furthermore, effects of different adsorption positions of sulfur atom on molecular memory are also discussed.
REVERSE NEAREST NEIGHBOR QUERIES IN FIXED DIMENSION
Authors: CHEONG OTFRIED , VIGNERON ANTOINE , YON JUYOUNG
Published: April 2011

Reverse nearest neighbor queries are defined as follows: Given an input point set P, and a query point q, find all the points p in P whose nearest point in P ∪ {q} \ {p} is q. We give a data structure to answer reverse nearest neighbor queries in fixed-dimensional Euclidean space. Our data structure uses O(n) space, its preprocessing time is O(n log n), and its query time is O( log n).
THE SIGNED BAD NUMBERS IN GRAPHS
Authors: GHAMESHLOU A. N. , KHODKAR ABDOLLAH , SHEIKHOLESLAMI S. M.
Published: April 2011

The closed neighborhood NG[v] of a vertex v in a graph G is the set consisting of v and of all neighborhood vertices of v. Let f be a function on V(G), the vertex set of G, into the set {-1, 1}. If ∑u∈N[v] f(u) ≤ 1 for all vertices v of G, then f is called a signed bad function of G. The maximum of the values of ∑v∈V(G) f(v), taking the maximum over all signed bad functions f of G, is called the signed bad number of G and denoted by β s (G). In this paper, we establish some upper bounds on the signed bad numbers for general graphs. In addition, we determine β s (G), when G is a complete graph, a cycle or a path.
GRAPHS THAT ARE NOT DOMATICALLY CO-CRITICAL
Authors: WALIKAR H. B. , SUDERSHAN REDDY L.
Published: April 2011

A graph G is said to be domatically co-critical, if d(G + uv) > d(G), for any two non-adjacent vertices u, v in G. In this paper we present the set of graphs that are not domatically co-critical.
Low Stress Polycrystalline SiC Thin Films Suitable for MEMS Applications
Authors: Fu Xiao-An , Dunning Jeremy L. , Mehregany Mehran , Zorman Christian A.
Published: April 2011

This paper details the development of low residual stress and low stress gradient unintentionally doped polycrystalline SiC (poly-SiC) thin films. The films were deposited in a large-volume, low-pressure chemical vapor deposition (LPCVD) furnace on 100 mm-diameter silicon (Si) wafers using dichlorosilane (SiH2Cl2) and acetylene (C2H2) as precursors. We found that the flow rate of SiH2Cl2 could be used to control the residual film stress in the as-deposited films. Wafer curvature measurements for ∼2 μm-thick films indicated that tensile stress ranging from 4 to 55 MPa across a 25 wafer boat had been achieved. A variety of micromachined structures including lateral resonant structures, stress pointers and cantilevers were fabricated for characterization of the deposited SiC films. The average Young’s modulus was found to be 403 GPa. Residual stress measurements were consistent with those obtained using a wafer curvature technique. Interferometric measurements of cantilever beams indicated stress gradients with an upper bound of 52 MPa/μm for ∼2 μm-thick films with tensile stress less than 55 MPa.
Optical Transitions and Internal Vibronic Frequencies of MnF
6
2 -  Ions in Cs2SiF6 and Cs2GeF6 Red Phosphors
Authors: Arai Yusuke , Adachi Sadao
Published: April 2011

Cs2SiF6:Mn4+ and Cs2GeF6:Mn4+ red phosphors are synthesized by chemically etching Si and Ge in aqueous HF/CsMnO4 solutions. Photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and Raman scattering techniques are used to investigate the optical properties of the phosphors. The Franck–Condon analysis of the PLE data yields the Mn4+-related optical transitions to occur at ∼2.39 and ∼2.35 eV (4A2→4T2) and at ∼2.82 and ∼2.79 eV (4A2→4T1) for Cs2SiF6:Mn4+ and Cs2GeF6:Mn4+, respectively. Temperature-dependent PL measurements are performed from 20 to 450 K in increments of 10 K, and the obtained results are well interpreted by taking into account the Bose–Einstein occupation factor. A complete set of infrared and Raman active frequencies, ν
1–ν
6, are determined from the PL and Raman scattering spectra of Cs2SiF6:Mn4+ and Cs2GeF6:Mn4+.
Interference-Free Determination of Dopamine at the Poly(thionine)-Modified Glassy Carbon Electrode
Authors: Ahammad A. J. Saleh , Nath Narayan Chandra Deb , Xu Guang-Ri , Kim Sunghyun , Lee Jae-Joon
Published: April 2011

A highly selective and sensitive electrochemical method, based on a poly(thionine)-modified glassy carbon electrode (PTH-GCE), was developed for the determination of dopamine (DA). The modified electrode was characterized by electrochemical techniques and an atomic force microscope (AFM). The modified GCE exhibited catalytic behavior towards the oxidation of DA in 0.1 M pH 7.0 phosphate buffer solution (PBS). In differential pulse voltammetry (DPV) measurements, the oxidation peak potential of ascorbic acid (AA), uric acid (UA) and serotonin (5-HT) overlapped with that of DA at the bare GCE. However, the oxidation peak of 5-HT was separated from that of DA at the PTH-GCE while the oxidation of AA and UA were suppressed at the same time. The peak potential separation of ca. 0.2 V was large enough for selective determination of DA from the interference of 5-HT. A linear range of 5.0–35.0 μM and a detection limit (S/N = 3) of 0.2 μM were obtained for DA detection in PBS (pH 7.0). This approach provides a simple and easy method to detect DA selectively from the interferences of AA, UA and 5-HT.
Probing Particle Movement in CMP with Fluorescence Technique
Authors: Lei Jun , Guo Dan , Luo Jianbin , Pan Guoshun
Published: April 2011

Chemical mechanical polishing (CMP) is now widely used in semiconductor manufacturing. Characterizing the particle movement in CMP is essential to understanding of the complicated material removal mechanisms for CMP. In this study, an experimental system based on fluorescence technique has been designed and developed. The particle displacement and velocity in the interface between a transparent wafer and a polishing pad were observed in-situ with the system. It can be found that some particles were embedded on the polishing pad and rotated with the pad. And the others were able to move free in slurry flow. All the particles in the experiments could be classified into four groups. The counting procedure suggested that the percentage of free particles in the field of view was between 10 and 50%. By analyzing the velocity of free particles at various rotation speeds and applied pressure, it was found that some of the free particles were able to travel at a speed 12–18 times the linear speed. The uncertainty in the velocity measurements was less than 8%. The objective of this study was to offer deep insights into the material removal mechanisms by measuring the real-time particle movement in CMP.
Ceramide inhibits Kv currents and contributes to TP-receptor-induced vasoconstriction in rat and human pulmonary arteries
Authors: Moral-Sanz Javier , Gonzalez Teresa , Menendez Carmen , David Miren , Moreno Laura , Macias Alvaro , Cortijo Julio , Valenzuela Carmen , Perez-Vizcaino Francisco , Cogolludo Angel
Published: April 2011

Neutral sphingomyelinase (nSMase)-derived ceramide has been proposed as a mediator of hypoxic pulmonary vasoconstriction (HPV), a specific response of the pulmonary circulation. Voltage-gated K+ (Kv) channels are modulated by numerous vasoactive factors, including hypoxia, and their inhibition has been involved in HPV. Herein, we have analyzed the effects of ceramide on Kv currents and contractility in rat pulmonary arteries (PA) and in mesenteric arteries (MA). The ceramide analog C6-ceramide inhibited Kv currents in PA smooth muscle cells (PASMC). Similar effects were obtained after the addition of bacterial sphingomyelinase (SMase), indicating a role for endogenous ceramide in Kv channel regulation. Kv current was reduced by stromatoxin and diphenylphosphine oxide-1 (DPO-1), selective inhibitors of Kv2.1 and Kv1.5 channels, respectively. The inhibitory effect of ceramide was still present in the presence of stromatoxin or DPO-1, suggesting that this sphingolipid inhibited both components of the native Kv current. Accordingly, ceramide inhibited Kv1.5 and Kv2.1 channels expressed in Ltk− cells. Ceramide-induced effects were reduced in human embryonic kidney 293 cells expressing Kv1.5 channels but not the regulatory subunit Kvβ2.1. The nSMase inhibitor GW4869 reduced the thromboxane-endoperoxide receptor agonist U46619-induced, but not endothelin-1-induced pulmonary vasoconstriction that was partly restored after addition of exogenous ceramide. The PKC-ζ pseudosubstrate inhibitor (PKCζ-PI) inhibited the Kv inhibitory and contractile effects of ceramide. In MA ceramide had no effect on Kv currents and GW4869 did not affect U46619-induced contraction. The effects of SMase were also observed in human PA. These results suggest that ceramide represents a crucial signaling mediator in the pulmonary vasculature.
Cardiovascular effects of treadmill exercise in physiological and pathological preclinical settings
Authors: Perrino Cinzia , Gargiulo Giuseppe , Pironti Gianluigi , Franzone Anna , Scudiero Laura , De Laurentis Mario , Magliulo Fabio , Ilardi Federica , Carotenuto Giuseppe , Schiattarella Gabriele Giacomo , Esposito Giovanni
Published: April 2011

Exercise adaptations result from a coordinated response of multiple organ systems, including cardiovascular, pulmonary, endocrine-metabolic, immunologic, and skeletal muscle. Among these, the cardiovascular system is the most directly affected by exercise, and it is responsible for many of the important acute changes occurring during physical training. In recent years, the development of animal models of pathological or physiological cardiac overload has allowed researchers to precisely analyze the complex cardiovascular responses to stress in genetically altered murine models of human cardiovascular disease. The intensity-controlled treadmill exercise represents a well-characterized model of physiological cardiac hypertrophy because of its ability to mimic the typical responses to exercise in humans. In this review, we describe cardiovascular adaptations to treadmill exercise in mice and the most important parameters that can be used to quantify such modifications. Moreover, we discuss how treadmill exercise can be used to perform physiological testing in mouse models of disease and to enlighten the role of specific signaling pathways on cardiac function.
Extracellular pyrophosphate metabolism and calcification in vascular smooth muscle
Authors: Villa-Bellosta Ricardo , Wang Xiaonan , Millán José Luis , Dubyak George R. , O'Neill W. Charles
Published: April 2011

Extracellular inorganic pyrophosphate (ePPi) is an important endogenous inhibitor of vascular calcification, but it is not known whether systemic or local vascular PPimetabolism controls calcification. To determine the role of ePPiin vascular smooth muscle, we identified the pathways responsible for ePPiproduction and hydrolysis in rat and mouse aortas and manipulated them to demonstrate their role in the calcification of isolated aortas in culture. Rat and mouse aortas contained mRNA for ectonucleotide pyrophosphatase/phosphodiesterases (NPP1–3), the putative PPitransporter ANK, and tissue-nonspecific alkaline phosphatase (TNAP). Synthesis of PPifrom ATP in aortas was blocked by β,γ-methylene-ATP, an inhibitor of NPPs. Aortas from mice lacking NPP1 ( Enpp1−/−) did not synthesize PPifrom ATP and exhibited increased calcification in culture. Although ANK-mediated transport of PPicould not be demonstrated in aortas, aortas from mutant ( ank/ank) mice calcified more in culture than did aortas from normal (ANK/ANK) mice. Hydrolysis of PPiwas reduced 25% by β,γ-methylene-ATP and 50% by inhibition of TNAP. Hydrolysis of PPiwas increased in cells overexpressing TNAP or NPP3 but not NPP1 and was not reduced in Enpp1−/−aortas. Overexpression of TNAP increased calcification of cultured aortas. The results show that smooth muscle NPP1 and TNAP control vascular calcification through effects on synthesis and hydrolysis of ePPi, indicating an important inhibitory role of locally produced PPi. Smooth muscle ANK also affects calcification, but this may not be mediated through transport of PPi. NPP3 is identified as an additional pyrophosphatase that could influence vascular calcification.