General route to design polymer molecular weight distributions through flow chemistry.

The properties of a polymer are known to be intrinsically related to its molecular weight distribution (MWD); however, previous methodologies of MWD control do not use a design and result in arbitrary shaped MWDs. Here we report a precise design to synthesis protocol for producing a targeted MWD design with a simple to use, and chemistry agnostic computer-controlled tubular flow reactor. To support the development of this protocol, we constructed general reactor design rules by combining fluid mechanical principles, polymerization kinetics, and experiments. The ring opening polymerization of lactide, the anionic polymerization of styrene, and the ring opening metathesis polymerization are used as model polymerizations to develop the reactor design rules and synthesize MWD profiles. The derivation of a mathematical model enables the quantitative prediction of the experimental results, and this model provides a tool to explore the limits of any MWD design protocol.

No effect of scapular position on 3-dimensional scapular motion in the throwing shoulder of healthy professional pitchers.

CONTEXT: Differences in 3-dimensional (3D) scapular motion have been reported between healthy baseball position players and healthy nonoverhead athletic controls, as well as players diagnosed with shoulder impingement syndrome. These alterations are theorized to be the result of adaptations due to the demands of repetitive throwing. However, comparisons between the throwing and nonthrowing shoulders are commonly used to infer normal motion. OBJECTIVE: The purpose of this study was to compare 3D scapular kinematics between the throwing and nonthrowing shoulders in asymptomatic professional male baseball pitchers. DESIGN: Cross-sectional study. SETTING: Laboratory. PARTICIPANTS: 45 asymptomatic professional baseball pitchers participating without restrictions during preseason training. INTERVENTIONS: An electromagnetic tracking system was used to assess 3D scapular orientation at rest and during weighted (2.3-kg) shoulder flexion across discrete humeral-flexion angles (rest, 30°, 60°, 90°, 120°, and maximum). MAIN OUTCOME MEASURE: 3D scapular upward/downward rotation (UR/DR), anteroposterior (AP) tilt, and internal/external rotation (IR/ER). Separate mixed-model ANOVAs (Side × Angle) for each scapular motion were used to compare the throwing and the nonthrowing shoulder across all angles. RESULTS: There were significant side-to-side differences with scapular UR/DR (P < .001), AP tilt (P < .001), and IR/ER (P < .001). The throwing scapula displayed greater mean UR (increase = 3.6°, SE = 0.50) and anterior/posterior tilt (increase = 2.1°, SE = 0.60) and less mean IR (decrease = 2.1°, SE = 0.66) than the nonthrowing shoulder averaged across all arm angles. CONCLUSIONS: In asymptomatic professional pitchers, the throwing shoulder's scapular position differs across all arm angles from that of the nonthrowing shoulder, but the motion does not differ. Scapular asymmetry that is consistent throughout arm elevation may be indicative not of pathology but, potentially, of a normal adaptation of the pitching shoulder.

Chronic renal failure: assessing the Fatigue Severity Scale for use among caregivers.

BACKGROUND: Quality of life for caregivers of end-stage renal disease patients has not been well addressed yet the physical and psychological status of this overlooked group can be important in the recovery or adaptation of patients with chronic renal failure, not to mention the caregivers themselves. One particular feature of the overall quality of life of such caregivers is that of fatigue. AIMS AND OBJECTIVES: The purpose of the study was to test the Fatigue Severity Scale for potential usefulness in assessing fatigue among a non-medical population, caregivers of end-stage renal disease patients. METHODS: Subjects completed a short battery of measures at either a dialysis centre or at home. RESULTS: The Short Form-12 of the Short Form-36 and the Center for Epidemiologic Studies Depression Scale accounted for 56% of the variance on the Fatigue Severity Scale. The results suggest that physical fatigue may be more prominent than mental fatigue as a feature of caregiver quality of life. CONCLUSIONS: The Fatigue Severity Scale which has been used for multiple sclerosis patients may prove to be useful as a short assessment of fatigue among the non-medical population of end-stage renal disease caregivers. This may result in improved interventions for the population of caregivers. RELEVANCE TO CLINICAL PRACTICE: Physicians, nurses and allied health professionals will be called on more frequently to assess and intervene with fatigued and overburdened caregivers in addition to patients themselves. A more thorough understanding of the nature of caregiver fatigue may drive changes or innovations with caregivers who are too often overlooked in the current era of scarce resources. Accordingly results of the study suggest that the direction in intervention may focus more on rest and respite as opposed to a need for psychosocial support or counselling. While there are various modes for assessing end-stage renal disease caregivers' fatigue, a simple measure like the Fatigue Severity Scale is brief enough to be administered without undue demand on practitioners or caregivers.

Prison wardens' perception of psychosocial and service needs of incarcerated women.

Wardens and administrators of 77 women's correctional facilities were mailed a questionnaire designed to assess the psychosocial and service needs of incarcerated female inmates nationally. 35 completed surveys were returned. Representativeness of the sample is discussed. Analysis identified attitudes about recent correctional trends perceived by wardens, including concerns about child care while incarcerated.

Fatigue among caregivers of chronic renal failure patients: a principal components analysis.

Quality of life for caregivers of ESRD patients has not been well addressed. The physical and psychological status of this overlooked group can be important in the recovery or adaptation of patients with chronic renal failure. One particular symptom of a reduced quality of life of such caregivers is that of fatigue. The study tested the reliability of both existing and newer fatigue measures. Measures with high reliability yielded a single construct of fatigue in a principal components analysis in this study of 99 caregivers. Implications for practice are addressed. Potential for further study is recommended.

One-arm hop test: reliability and effects of arm dominance.

STUDY DESIGN: Test-retest reliability analysis and 2-factor ANOVA contrast of athletic group and limb dominance. OBJECTIVES: To determine the reliability of the one-arm hop test and the effects of upper-extremity dominance on test scores for 2 athletic groups. BACKGROUND: Limited information is available regarding functional performance tests of the upper extremity that involve axial loading. METHODS AND MEASURES: Thirteen male collegiate wrestlers (mean age, 20.3 +/- 1.6 years) and 13 male collegiate football players (mean age, 20.0 +/-1.7 years) without upper-extremity pathology participated in the study. Subjects were trained to perform the one-arm hop test, starting from a one-arm push-up position and then hopping as quickly as possible onto and off of a 10.2-cm platform 5 times. Subjects returned to the test site 1 to 2 days later and were timed for 2 trials of the one-arm hop test for each upper extremity. RESULTS: Within-session ICC2,1 reliability values were 0.78 for the football players and 0.81 for the wrestlers. Mean absolute differences between trials were 0.64 seconds for the football players and 0.47 seconds for the wrestlers. Trial 2 performance times were significantly faster than trial 1 times for the wrestlers. Although performance time for the nondominant side was on average 4.4% slower than that of the dominant side, performance times for the dominant side were not significantly different from those of the nondominant upper extremities. CONCLUSIONS: The results provide preliminary evidence that the one-arm hop test may be a reliable upper-extremity functional performance test with sufficient training of the subject. Uninjured upper-extremity performance for the one-arm hop test may be useful as a basis for comparing performance of an injured contralateral upper extremity.