Analysis of diffuse scattering in electron diffraction data for the crystal structure determination of Pigment Orange 13, C32H24Cl2N8O2.

The crystallographic study of two polymorphs of the industrial pyrazolone Pigment Orange 13 (P.O.13) is reported. The crystal structure of the ß phase was determined using single-crystal X-ray analysis of a tiny needle. The α phase was investigated using three-dimensional electron diffraction. The electron diffraction data contain sharp Bragg reflections and strong diffuse streaks, associated with severe stacking disorder. The structure was solved by careful analysis of the diffuse scattering, and similarities of the unit-cell parameters with the ß phase. The structure solution is described in detail and this provides a didactic example of solving molecular crystal structures in the presence of diffuse scattering. Several structural models were constructed and optimized by lattice-energy minimization with dispersion-corrected DFT. A four-layer model was found, which matches the electron diffraction data, including the diffuse scattering, and agrees with X-ray powder data. Additionally, five further phases of P.O.13 are described.

Factors associated with a more rapid recovery after anterior cruciate ligament reconstruction using multivariate analysis.

BACKGROUND: In the past, several studies investigated factors that are prognostic or associated with outcome after anterior cruciate ligament (ACL) reconstruction. A recent review showed that only limited evidence is available for most studied factors, and that insufficient analysis methods were used commonly. Therefore, the aim of this study was to add more weight to the existing evidence, about factors that are associated with a more rapid outcome after ACL reconstruction. The second aim was to use multivariate analysis to study the possible factors independently. METHODS: A cohort study was conducted with a follow-up of six months. Before surgery, patient variables were scored. Surgical variables were scored during arthroscopic ACL reconstructions with a single-bundle technique and hamstring autograft. The Lysholm score and subscales of the Knee Injury Osteoarthritis Outcome Score (KOOS) were assessed six months post surgery. A multiple analysis of variance (ANOVA) model was used to identify prognostic factors for outcome. RESULTS: In total, 118 patients were included. Patients, aged ≤30years, with a subjective knee score ≥ six, with normal flexion range of motion (ROM) of the knee, with flexion and extension strength deficit of ≤20%, and those with no previous knee surgery in the same knee at baseline scored significantly higher on outcome after multivariate analysis. No significant effect of surgical factors could be found. CONCLUSION: Younger age, higher subjective knee score, normal knee flexion, normal knee flexion and extension strength, and no previous knee surgery in the patients' history at baseline are associated with a more rapid recovery after ACL reconstruction. LEVEL OF EVIDENCE: Level III, prognostic study.

Land management practices interactively affect wetland beetle ecological and phylogenetic community structure.

Management practices can disturb ecological communities in grazing lands, which represent one-quarter of land surface. But three knowledge gaps exist regarding disturbances: disturbances potentially interact but are most often studied singly; experiments with multiple ecosystems as treatment units are rare; and relatively new metrics of phylogenetic community structure have not been widely applied. We addressed all three of these needs with a factorial experiment; 40 seasonal wetlands embedded in a Florida ranch were treated with pasture intensification, cattle exclosure, and prescribed fire. Treatment responses were evaluated through four years for aquatic beetle (Coleoptera: Adephaga) assemblages using classic ecological metrics (species richness, diversity) and phylogenetic community structure (PCS) metrics. Adephagan assemblages consisted of 23 genera representing three families in a well-resolved phylogeny. Prescribed fire significantly reduced diversity one year post-fire, followed by a delayed pasture X fire interaction. Cattle exclosure significantly reduced one PCS metric after one year and a delayed pasture x fence x fire interaction was detected with another PCs metric. Overall, effects of long-term pasture intensification were modified by cattle exclosure and prescribed fire. Also, PCS metrics revealed effects otherwise undetected by classic ecological metrics. Management strategies (e.g., "flash grazing," prescribed fires) in seasonal wetlands may successfully balance economic gains from high forage quality with ecological benefits of high wetland diversity in otherwise simplified grazing lands. Effects are likely taxon specific; multiple taxa should be similarly evaluated.

On the correlation between hydrogen bonding and melting points in the inositols.

Inositol, 1,2,3,4,5,6-hexahydroxycyclohexane, exists in nine stereoisomers with different crystal structures and melting points. In a previous paper on the relationship between the melting points of the inositols and the hydrogen-bonding patterns in their crystal structures [Simperler et al. (2006 ▶). CrystEngComm 8, 589], it was noted that although all inositol crystal structures known at that time contained 12 hydrogen bonds per molecule, their melting points span a large range of about 170 °C. Our preliminary investigations suggested that the highest melting point must be corrected for the effect of molecular symmetry, and that the three lowest melting points may need to be revised. This prompted a full investigation, with additional experiments on six of the nine inositols. Thirteen new phases were discovered; for all of these their crystal structures were examined. The crystal structures of eight ordered phases could be determined, of which seven were obtained from laboratory X-ray powder diffraction data. Five additional phases turned out to be rotator phases and only their unit cells could be determined. Two previously unknown melting points were measured, as well as most enthalpies of melting. Several previously reported melting points were shown to be solid-to-solid phase transitions or decomposition points. Our experiments have revealed a complex picture of phases, rotator phases and phase transitions, in which a simple correlation between melting points and hydrogen-bonding patterns is not feasible.

4,4'-{Diazenediylbis[(1,4-phenylene)bis(carbonyloxy)]}bis(2,2,6,6-tetramethylpiperidinyloxidanyl): the first crystal structure determination from powder data of a nitroxide radical.

The title compound, C32H42N4O6, is a novel nitroxide radical used for pulsed electron-electron double resonance (PELDOR) spectroscopy. Its crystal structure was determined from laboratory X-ray powder diffraction data. The attractive forces between the molecules in the crystal structure are mainly of dispersive nature. A special interaction of the nitroxide radicals was not observed.

Effectiveness of an injury prevention programme for adult male amateur soccer players: a cluster-randomised controlled trial.

BACKGROUND: The incidence rate of soccer injuries is among the highest in sports, particularly for adult male soccer players. PURPOSE: To investigate the effect of the 'The11' injury prevention programme on injury incidence and injury severity in adult male amateur soccer players. STUDY DESIGN: Cluster-randomised controlled trial. METHODS: Teams from two high-level amateur soccer competitions were randomly assigned to an intervention (n=11 teams, 223 players) or control group (n=12 teams, 233 players). The intervention group was instructed to perform The11 in each practice session during one soccer season. The11 focuses on core stability, eccentric training of thigh muscles, proprioceptive training, dynamic stabilisation and plyometrics with straight leg alignment. All participants of the control group continued their practice sessions as usual. RESULTS: In total, 427 injuries were recorded, affecting 274 of 456 players (60.1%). Compliance with the intervention programme was good (team compliance=73%, player compliance=71%). Contrary to the hypothesis, injury incidences were almost equal between the two study groups: 9.6 per 1000 sports hours (8.4-11.0) for the intervention group and 9.7 (8.5-11.1) for the control group. No significant differences were found in injury severity, but a significant difference was observed in the location of the injuries: players in the intervention group sustained significantly less knee injuries. CONCLUSIONS: This study did not find significant differences in the overall injury incidence or injury severity between the intervention and control group of adult male soccer players. More research is recommended, focusing on injury aetiology and risk factors in adult male amateur soccer players.

Nimustine hydrochloride: the first crystal structure determination of a 2-chloroethyl-N-nitrosourea hydrochloride derivative by X-ray powder diffraction and solid-state NMR.

Nimustine hydrochloride [systematic name: 4-amino-5-({[N-(2-chloroethyl)-N-nitrosocarbamoyl]amino}methyl)-2-methylpyrimidin-1-ium chloride], C(9)H(14)ClN(6)O(2)(+)·Cl(-), is a prodrug of CENU (chloroethylnitrosourea) and is used as a cytostatic agent in cancer therapy. Its crystal structure was determined from laboratory X-ray powder diffraction data. The protonation at an N atom of the pyrimidine ring was established by solid-state NMR spectroscopy.

2-Ammonio-5-chloro-4-methylbenzenesulfonate, its 1-methyl-2-pyrrolidone and dimethyl sulfoxide monosolvates and a corrected structure of 2,2'-(1,4-phenylene)di(4,5-dihydroimidazolium) bis(4-aminobenzenesulfonate) dihydrate.

2-Ammonio-5-chloro-4-methylbenzenesulfonate, C(7)H(8)ClNO(3)S, (Ia), is an intermediate in the synthesis of lake red azo pigments. The present structure determination from single-crystal data confirms the results of a previous powder diffraction determination [Bekö, Thoms, Brüning, Alig, van de Streek, Lakatos, Glaubitz & Schmidt (2010). Z. Kristallogr. 225, 382-387]. The zwitterionic tautomeric form is confirmed. During a polymorph screening, two additional pseudopolymorphs were obtained, viz. 2-ammonio-5-chloro-4-methylbenzenesulfonate 1-methyl-2-pyrrolidone monosolvate, C(7)H(8)ClNO(3)S·C(5)H(9)NO, (Ib), and 2-ammonio-5-chloro-4-methylbenzenesulfonate dimethyl sulfoxide monosolvate, C(7)H(8)ClNO(3)S·C(2)H(6)OS, (Ic). The molecules of (Ib) have crystallographic m symmetry. The 1-methyl-2-pyrrolidone solvent molecule has an envelope conformation and is disordered around the mirror plane. The structure shows hydrogen-bonded ladders of molecules [graph-set notation C(2)(2)(6)R(2)(2)(12)] in the [010] direction. The benzene groups of adjacent ladders are also stacked in this direction. A different type of hydrogen-bonded ladder [graph-set notation C(6)R(2)(2)(4)R(4)(4)(12)] occurs in (Ic). In (Ia), (Ib) and (Ic), the molecules correspond to the zwitterionic tautomer. The structure of the cocrystal of 4-aminobenzenesulfonic acid with 1,4-bis(4,5-dihydroimidazol-2-yl)benzene [Shang, Ren, Wang, Lu & Yang (2009). Acta Cryst. E65, o2221-o2222] is corrected; it actually contains 4-aminobenzenesulfonate anions and 2,2'-(1,4-phenylene)di(dihydroimidazolium) dications, i.e. 2,2'-(1,4-phenylene)di(4,5-dihydroimidazolium) bis(4-aminobenzenesulfonate) dihydrate, C(12)H(16)N(4)(2+)·2C(6)H(6)NO(3)S(-)·2H(2)O. Hence, all known structures of aminobenzenesulfonic acid complexes contain ionic or zwitterionic molecules; there is no known structure with a neutral aminobenzenesulfonic acid molecule.

Tizanidine and tizanidine hydrochloride: on the correct tautomeric form of tizanidine.

A crystallization series of tizanidine hydrochloride, used as a muscle relaxant for spasticity acting centrally as an α(2)-adrenergic agonist, yielded single crystals of the free base and the hydrochloride salt. The crystal structures of tizanidine [systematic name: 5-chloro-N-(imidazolidin-2-ylidene)-2,1,3-benzothiadiazol-4-amine], C(9)H(8)ClN(5)S, (I), and tizanidine hydrochloride {systematic name: 2-[(5-chloro-2,1,3-benzothiadiazol-4-yl)amino]imidazolidinium chloride}, C(9)H(9)ClN(5)S(+)·Cl(-), (II), have been determined. Tizanidine crystallizes with two almost identical molecules in the asymmetric unit (r.m.s. deviation = 0.179 Å for all non-H atoms). The molecules are connected by N-H···N hydrogen bonds forming chains running along [2 ̅11]. The present structure determination corrects the structure determination of tizanidine by John et al. [Acta Cryst. (2011), E67, o838-o839], which shows an incorrect tautomeric form. Tizanidine does not crystallize as the usually drawn 2-amino-imidazoline tautomer, but as the 2-imino-imidazolidine tautomer. This tautomer is present in solution as well, as shown by (1)H NMR analysis. In tizanidine hydrochloride, cations and anions are connected by N-H···Cl hydrogen bonds to form layers parallel to (100).

Monitoring performance, pituitary-adrenal hormones and mood profiles: how to diagnose non-functional over-reaching in male elite junior soccer players.

OBJECTIVE: To verify if in male elite junior soccer players a minimum 1-month performance decrease is accompanied by a mood profile and hormone levels typical of non-functional over-reaching (NFOR). DESIGN: A prospective case-control study using a monthly performance monitor with a standardised field test to detect the performance changes. Players with a performance decrease lasting at least 1 month were compared with control players without a performance decrease on mood scores and pre-exercise and postexercise levels of stress hormones. SETTING: Sporting field and sports medical laboratory. PARTICIPANTS: Ninety-four young elite soccer players were monitored during the 2006-2008 seasons. Twenty-one players were invited to the laboratory, seven of whom showed a significant performance decrease. MAIN OUTCOME MEASURES: Performance change over time, scores on the profile of mood states and premaximal and postmaximal exercise serum levels of adrenocorticotropic hormone (ACTH), growth hormone (GH) and cortisol. RESULTS: Players with a performance decrease showed psychological and hormonal changes typical of the non-functional state of over-reaching. Scores were higher on depression and anger, whereas the resting GH levels and ACTH levels after maximal exercise were reduced. ACTH and GH were capable of classifying all but one player correctly as either NFOR or control. CONCLUSIONS: Performance-related criteria in field tests are capable of identifying players with worsened mood and adaptations of the endocrine system that fit the definition of NFOR. Performance, mood and hormone levels may therefore be considered as valid instruments to diagnose NFOR in young elite soccer players.

Can we detect non-functional overreaching in young elite soccer players and middle-long distance runners using field performance tests?

OBJECTIVE: To study whether field performance tests can make a valid distinction between non-functionally overreaching (NFO) athletes and control athletes. DESIGN: Monthly field performance tests were used to determine a performance decrement (PD) throughout a season. Athletes with a minimum of 1 month PD were compared with control athletes without a PD on mood characteristics and resting levels of stress hormones. SETTING: Sporting field and sports medical laboratory. PARTICIPANTS: 129 young elite athletes, 77 soccer players and 52 middle-long distance runners were followed prospectively during the 2006-2007 season. Fifteen of them were invited to the laboratory. Eight athletes showed a performance decrease lasting longer than 1 month, and seven athletes without a performance decrease acted as their controls. MAIN OUTCOME MEASURES: Performance changes over time were measured using field tests. Profile of Mood States and resting levels of adrenocorticotrophic hormone (ACTH) and cortisol in blood were measured in the laboratory. RESULTS: PD athletes showed several symptoms typical of the non-functional state of overreaching (OR). The PD group scored higher on depression and anger than controls. They also showed a specific pattern of correlations between negative mood subscales (tension, fatigue and depression), which was absent in controls. ACTH levels at rest were similar, but lower cortisol levels in PD athletes pointed at a blunted cortisol response. Cortisol levels were decoupled from ACTH levels only in PD athletes. CONCLUSIONS: Implementing performance-related criteria in field tests can help coaches and sports physicians to distinguish NFO athletes from athletes with balanced workload and recovery.

Injury prevention target groups in soccer: injury characteristics and incidence rates in male junior and senior players.

To identify target groups for injury prevention in male amateur soccer players under 35 years of age. A computer-assisted telephone survey with a 12-month recall period for injuries in a representative sample of Dutch citizens from the Injuries and Physical Activity Netherlands (IPAN)-database. A comparison of the volume of soccer injuries, the incidence and the need for medical attention per level of exposure and age category. The incidence in seniors was twice that of juniors (17.5% versus 8.1%; odds ratio (OR=2.4). In juniors the overall incidence was lowest in the category with the least amount of soccer exposure time (0-3 h: 2.9%; 3-5 h: 13.0%; 5+ h: 12.3%). A comparable result was found in seniors: (0-3 h: 12.0%; 3-5 h: 21.6%; 5+ h: 21.5%). Within each level of soccer exposure, a different incidence was found in juniors and seniors (0-3 h: OR=4.6; 3-5 h: OR=1.8; 5+ h: OR=1.9). Ankle, knee and upper leg injuries were most common (59.9%). Contusions, strains and sprains dominated (78.1%). Body region and type of injuries were similar in both age categories. Medical treatment for injuries was equally necessary in both age groups. Senior male amateur soccer players and particularly the more skilled seniors (involved in soccer at least 3 h per week), should be primarily targeted for studies on injury risk factors and prevention programs.

Effectiveness and cost-effectiveness of an injury prevention programme for adult male amateur soccer players: design of a cluster-randomised controlled trial.

BACKGROUND AND AIMS: Approximately 16% of all sports injuries in the Netherlands are caused by outdoor soccer. A cluster-randomised controlled trial has been designed to investigate the effectiveness and cost-effectiveness of an injury prevention programme ('The11') for male amateur soccer players. The injury prevention programme The11, developed with the support of the World Football Association FIFA, aims to reduce the impact of intrinsic injury risk factors in soccer. METHODS: Teams playing at first-class amateur level in two districts in the Netherlands are participating in the study. Teams in the intervention group were instructed to apply The11 during each practice session throughout the 2009-10 season. All participants of the control group continued their practice sessions as usual. All soccer-related injuries and related costs for each team were systematically reported online by a member of the medical staff. Player exposure to practice sessions and matches was reported weekly by the coaches. Also the use of The11 during the season after the intervention season will be monitored. DISCUSSION: Our hypothesis is that integrating the The11 exercises in the warm-up for each practice session is effective in terms of injury incidence, injury severity, healthcare use, and its associated costs and/or absenteeism. Prevention of soccer injuries is expected to be beneficial to adult soccer players, soccer clubs, the Royal Dutch Football Association (KNVB), health insurance companies and society.

Monitoring load, recovery, and performance in young elite soccer players.

The purpose of this study was to investigate the relation between training load, recovery, and monthly field test performance in young elite soccer players to develop training guidelines to enhance performance. In a prospective, nonexperimental cohort design, 18 young elite soccer players registered training and match duration for a full competitive season by means of daily training logs. Furthermore, session rating of perceived exertion (RPE) and total quality of recovery (TQR) scores were recorded. Weekly duration (TL(d)), load (duration x session RPE = TL(rpe)), and TQR scores were calculated for 1 and 2 weeks before a monthly submaximal interval shuttle run tests to determine interval endurance capacity. Participants spent on average 394.4 +/- 134.9 minutes per week on training and game play with an average session RPE of 14.4 +/- 1.2 (somewhat hard) and TQR of 14.7 +/- 1.3 (good recovery). Random intercept models showed that every extra hour training or game play resulted in enhanced field test performance (p < 0.05). Session RPE and TQR scores did not contribute to the prediction of performance. The duration of training and game play in the week before field test performance is most strongly related to interval endurance capacity. Therefore, coaches should focus on training duration to improve interval endurance capacity in elite soccer players. To evaluate the group and individual training response, field tests should be frequently executed and be incorporated in the training program.

Assessment of the effects of physical training in patients with chronic heart failure: the utility of effort-independent exercise variables.

Traditionally, the effects of physical training in patients with chronic heart failure (CHF) are evaluated by changes in peak oxygen uptake (peak VO(2)). The assessment of peak VO(2), however, is highly dependent on the patients' motivation. The aim of the present study was to evaluate the clinical utility of effort-independent exercise variables for detecting training effects in CHF patients. In a prospective controlled trial, patients with stable CHF were allocated to an intervention group (N = 30), performing a 12-week combined cycle interval and muscle resistance training program, or a control group (N = 18) that was matched for age, gender, body composition and left ventricular ejection fraction. The following effort-independent exercise variables were evaluated: the ventilatory anaerobic threshold (VAT), oxygen uptake efficiency slope (OUES), the V(E)/VCO(2) slope and the time constant of VO(2) kinetics during recovery from submaximal constant-load exercise (tau-rec). In addition to post-training increases in peak VO(2) and peak V(E), the intervention group showed significant within and between-group improvements in VAT, OUES and tau-rec. There were no significant differences between relative improvements of the effort-independent exercise variables in the intervention group. In contrast with VAT, which could not be determined in 9% of the patients, OUES and tau-rec were determined successfully in all patients. Therefore, we conclude that OUES and tau-rec are useful in clinical practice for the assessment of training effects in CHF patients, especially in cases of poor subject effort during symptom-limited exercise testing or when patients are unable to reach a maximal exercise level.

Evaluation and opportunities in overtraining approaches.

Overtraining (OT) as a sports phenomenon can be caused by stressors on various levels (physical, emotional, psychological, and social) and evokes responses on these levels. This study evaluated research and new opportunities in the field of OT by introducing an integrated multidisciplinary approach, based on the single and multistressors approach. The single stressor approach focuses on the training load-recovery imbalance, which results in a stagnating performance, excluding the etiology by nonsport-related factors. The multistressors approach includes all factors as relevant in the etiology of a stagnating performance. In future studies on OT an integrative approach should not only highlight changes in training regimes and specific responses to training stressors but also focus on the role of training-related recovery, the impact of stressors, and personality factors influencing stress appraisal. This will provide a better insight into the etiology and consequences of OT necessary for prevention and treatment in sport practice, and enhance the focus on adequate recovery (good sleep, sufficient rest periods) and athletes' stress-related responses.

Two new cobalt(II) fumarates and a redetermination of tetraaquacobalt(II) fumarate monohydrate.

Poly[triaqua-mu(4)-fumarato-cobalt(II)], [Co(C(4)H(2)O(4))(H(2)O)(3)](n), (I), contains two symmetry-independent octahedrally coordinated Co(2+) ions, both on inversion centers. One Co(2+) ion is coordinated by two water molecules and four fumarate dianions, whereas the other Co(2+) ion is surrounded by four water molecules and two fumarate dianions. Each fumarate dianion is bonded to three Co(2+) ions, leading to a two-dimensional structure. The fumarate dianions are nonplanar; the angle between the planes of the two carboxylate groups is 54.9 (2) degrees. The cobalt(II) fumarate layers are connected by hydrogen bonding into a three-dimensional network. Compound (I) is not isostructural with calcium(II) fumarate trihydrate [Gupta et al. (1972). Acta Cryst. B28, 135-139]. In poly[mu(4)-fumarato-dimethanolcobalt(II)], [Co(C(4)H(2)O(4))(CH(4)O)(2)](n), (II), the Co(2+) ions are octahedrally coordinated by four fumarate dianions and two methanol molecules, leading to a three-dimensional structure. The fumarate group is planar. The Co(2+) ions and the fumarate dianions both lie on inversion centers. Additionally, the one-dimensional structure of catena-poly[[[tetraaquacobalt(II)]-mu(2)-fumarato] monohydrate], {[Co(C(4)H(2)O(4))(H(2)O)(4)].H(2)O}(n), (III), was redetermined at a higher resolution, and the space group C2/c was confirmed.

National survey on sports injuries in the Netherlands: target populations for sports injury prevention programs.

OBJECTIVE: To define target populations for sports injury prevention programs. DESIGN: A computer-assisted telephone survey on sports injuries and sports participation during 2000-2005 using a 3-month recall period. SETTING: Data obtained from a representative sample of Dutch citizens. PARTICIPANTS: Fifty-eight thousand four hundred five Dutch citizens aged older than 3 years. ASSESSMENT OF RISK FACTORS: Age, gender, and type of sports were used to distinguish subgroups with a substantial contribution to sports injuries. MAIN OUTCOME MEASURES: The absolute number of sports injuries, the incidence of sports injuries per 10,000 hours, the severity, and costs of sports injuries. RESULTS: Sports participation was associated with 1.5 million injuries per year and 10 injuries per 10,000 hours; of these, 50% had to be treated medically. Two-thirds of all medically treated sports injuries were associated with 9 sports (representing 18 subpopulations, all younger than 55 years): outdoor soccer (males 4-54 years and females 4-17 years), indoor soccer (males 18-34 years), tennis (males/females 35-54 years), volleyball (females 18-54 years), field hockey (males 18-34 years and females 4-17 years), running/jogging (males/females 35-54 years), gymnastics (males/females 4-17 years), skiing/snowboarding (males 4-17 years and females 18-34 years), and equestrian sports (females 18-34 years). These groups showed more than average injury rates and covered two-thirds of all direct and indirect costs (euro 400 million). CONCLUSIONS: The survey identified the most important (sports-, age-, and gender-specific) target populations for injury prevention programs in the Netherlands. Sports participants aged older than 55 years were excluded from these target groups because of their limited contribution to the total sports injury problem.