27—CAM-TO-NEEDLE IMPACT FORCES IN WEFT-KNITTING PART IV: FURTHER MEASUREMENTS OF STITCH-CAM IMPACT

Experiments are described in which the effects of certain needle modifications (e.g., a crimped needle, changes in butt shape, and the removal of surrounding needles) on the impact force between the stitch cam and needle were investigated. It is also shown that, although the presence of lubricating oil had a negligible effect on the magnitude of the impact force, it had a damping effect on transient oscillations and shortened the time of needle bounces on the stitch cam. Increasing the machine speed also increased the number of bounces, and their duration was longer.     

29—THE MODIFICATION OF A TASLAN JET TO OPERATATE LOW AIR-PRESSURES

Theoretical considerations of the air-jet texturing process have led to experiments with a texturing jet modified by inserting a plug to block off the secondary air-stream passing over the feed needle. This has intensified the action of the primary turbulent air-stream so that the false-untwisting mechanism, described earlier, can occur at lower air-pressures. The false-twisting of a stationary yam is compared for both the modified and the normal jets. Tests of physical-bulk and yarn-stability properties reveal that yams made with the modified jet at low air-pressure are similar to those made with the normal jet at the usual commercial pressure. This could result in a 65% saving in the air quantities used. It is also shown that the angular positioning of the feed needle is not as critical with the modified system as it is with the original system.     

Sequestration and Metabolism of Host-Plant Flavonoids by the Lycaenid Butterfly Polyommatus bellargus

Larvae of the lycaenid butterfly Polyommatus bellargus were reared on leaves of Coronilla varia that are rich in flavone C-glycosides. Six flavonoids including isovitexin and isoorientin, as well as several of their congeners were isolated and identified by spectroscopic means. Comparative HPLC analysis of the host plant and of larvae, pupae, and imagines of P. bellargus indicated selective uptake of isovitexin versus isoorientin derivatives. Isovitexin-2″-O-xyloside was the major flavonoid detected in pupae and in imagines of P. bellargus. Several minor components were tentatively identified as quercetin- and kaempferol-O-glycosides based on their on line-UV spectra and by comparison with known standards. Since leaves of the host plant accumulate exclusively flavones, the flavonol glycosides are considered to be biotransformation products that are formed by the insects and/ or by symbiotic bacteria. Imagines of P. bellargus caught in the wild exhibited similar flavonoid patterns compared to imagines reared in the laboratory. Within the imagines, approximately 80% of all flavonoids are stored in the wings (especially in the orange submarginal lunules), whereas the remaining 20% resides in the bodies. Female butterflies show a significantly higher flavonoid concentration than males. It is suggested that the sequestered flavonoids are involved in visual mate recognition.     

Hemodialysis decreases carotid‐brachial and carotid‐femoral pulse wave velocities: A 5‐year follow‐up study

Aortic stiffness is a prognostic parameter associated with patient mortality. Vascular access creation has been shown to have effects on arterial stiffness both in the aorta and in the upper limb arteries in chronically hemodialyzed patients (CHPs). However, no longitudinal studies have been conducted in order to characterize the evolution of arterial stiffness in CHPs. The aims of this work were (a) to measure baseline pulse wave velocity (PWV) in the carotid‐femoral and in right and left carotid‐brachial pathways in a cohort of CHP and (b) to conduct a 5‐year prospective study on the same cohort to determine possible time‐related differences. Pulse wave velocity was measured both in the carotid‐femoral and in the carotid‐brachial pathways, and clinical and biochemical parameters were collected in 25 CHPs, which were followed up after a 5‐year lapse. Right and left carotid‐brachial pathway PWV values showed significant decreases after the 5‐year follow‐up, independently of the presence of the vascular access (P < 0.001). Additionally, baseline carotid‐brachial PWV was significantly higher (P < 0.001) than values measured 5 years later for upper limbs with vascular access (11.97 ± 2.97 m/sec vs. 6.76 ± 1.48 m/sec, respectively) and without vascular access (12.25 ± 2.38 m/sec vs. 7.18 ± 1.88 m/sec, respectively). Similarly, PWV values in the carotid‐femoral pathway decreased significantly (P < 0.001) over the same period (13.27 ± 2.96 m/sec vs. 9.75 ± 2.99 m/sec, respectively). The 5‐year follow‐up of PWV showed significant decreases in both carotid‐brachial and carotid‐femoral pathways. The general changes in arterial stiffness could be related to the vascular access creation, hemodialysis therapy, and to the improvement of arterial pressure management.     

The association between the quality of inpatient care and early readmission: a meta-analysis of the evidence

OBJECTIVES: To help resolve the current controversy over the validity of early readmission as an indicator of the quality of care, the authors critically reviewed the literature using meta-analysis to derive summary estimates of effect and evaluate inter-study heterogeneity. METHODS: The authors selected reports meeting five criteria: (1) presentation of new data on medical-surgical hospitalization of adults; (2) measurement of outcome as a person-specific readmission; (3) readmission within < or = 31 days; (4) examination of some aspect of the process of inpatient care; (5) inclusion of a comparison group. One meta-analysis examined 13 comparisons of readmission rates after substandard versus normative care, another examined 9 comparisons of readmission rates after normative versus exceptional care, and the third examined all 22 comparisons together. Two authors applied inclusion criteria and extracted data on methods and findings. Two others classified studies on 11 methodological variables for the heterogeneity evaluation. RESULTS: The summary odds ratio for readmission after substandard care was 1.24 (0.99-1.57) relative to normative care; for readmission after normative care the summary odds ratio was 1.45 (0.90-2.33) relative to exceptional care. The individual odds ratios varied significantly (chi2, 21 df = 50.34, P = 0.0003). Most of the variance in study odds ratios could be explained by whether the study focused on the quality of patient care or the qualifications of patient care providers. The summary odds ratio for the 16 homogeneous comparisons focusing on the quality of patient care was 1.55 (1.25-1.92). CONCLUSIONS: Early readmission is significantly associated with the process of inpatient care. The risk of early readmission is increased by 55% when care is of relatively low quality, that is, substandard or normative instead of normative or exceptional.     

On the causes of collapse and sudden death by Avicenna

Avicenna's views on the causes of collapse and sudden death are presented from a literal translation of the mediaeval Arabic text. Medical knowledge based on observation mixed with pure abstract reasoning forms the essence of Avicenna's medical writings.     

Long-term outcomes of patients receiving percutaneous endoscopic gastrostomy tubes

OBJECTIVE: Percutaneous endoscopic gastrostomy (PEG) tube placement is the preferred method for long-term enteral feeding of patients who are unable to take food by mouth. Despite the widespread acceptance of the procedure, no large-scale study of the long-term outcomes of patients receiving PEG tubes has been reported. The objective of this study was to determine the survival of patients in whom PEG tubes are placed. DESIGN: Retrospective cohort study using data obtained from two computerized databases. SETTING: Department of Veterans Affairs hospitals. PATIENTS: Seven thousand three hundred sixty-nine patients who received a PEG tube in fiscal years 1990 through 1992. RESULTS: For the 7,369 patients, the mean age was 68.1 years and 98.6% were men. PEG tubes were most commonly places in patients with cerebrovascular disease (18.9%), other organic neurologic disease (28.6%), or head and neck cancer (15.7%). Although the complication rate of the procedure itself was low (4%), because of the severity of their underlying disease, 1,732 patients (23.5%) died during the hospitalization in which the PEG tube was placed. The median survival of the full cohort was 7.5 months. CONCLUSIONS: This study documents the widespread placement of PEG tubes in severely ill patients, half of whom are in the terminal phase of their illness. Further study is needed to determine whether these patients benefit from PEG tube placement in terms of their quality of life and survival.