Durability and Wear Resistance of Laser-Textured Hardened Stainless Steel Surfaces with Hydrophobic Properties.

Hydrophobic surfaces are of high interest to industry. While surface functionalization has attracted significant interest, from both industry and research, the durability of engineered surfaces remains a challenge, as wear and scratches deteriorate their functional response. In this work, a cost-effective combination of surface engineering processes on stainless steel was investigated. Low-temperature plasma surface alloying was applied to increase surface hardness from 172 to 305 HV. Then, near-infrared nanosecond laser patterning was deployed to fabricate channel-like patterns that enabled superhydrophobicity. Abrasion tests were carried out to examine the durability of such engineered surfaces during daily use. In particular, the evolution of surface topographies, chemical composition, and water contact angle with increasing abrasion cycles were studied. Hydrophobicity deteriorated progressively on both hardened and raw stainless steel samples, suggesting that the major contributing factor to hydrophobicity was the surface chemical composition. At the same time, samples with increased surface hardness exhibited a slower deterioration of their topographies when compared with nontreated surfaces. A conclusion is made about the durability of laser-textured hardened stainless steel surfaces produced by applying the proposed combined surface engineering approach.

Pupil constriction evoked in vitro by stimulation of the oculomotor nerve in the turtle (Trachemys scripta elegans).

The pond turtle (Trachemys scripta elegans) exhibits a notably sluggish pupillary light reflex (PLR), with pupil constriction developing over several minutes following light onset. In the present study, we examined the dynamics of the efferent branch of the reflex in vitro using preparations consisting of either the isolated head or the enucleated eye. Stimulation of the oculomotor nerve (nIII) using 100-Hz current trains resulted in a maximal pupil constriction of 17.4% compared to 27.1% observed in the intact animal in response to light. When current amplitude was systematically increased from 1 to 400 microA, mean response latency decreased from 64 to 45 ms, but this change was not statistically significant. Hill equations fitted to these responses indicated a current threshold of 3.8 microA. Stimulation using single pulses evoked a smaller constriction (3.8%) with response latencies and threshold similar to that obtained using train stimulation. The response evoked by postganglionic stimulation of the ciliary nerve using 100-Hz trains was largely indistinguishable from that of train stimulation of nIII. However, application of single-pulse stimulation postganglionically resulted in smaller pupil constriction at all current levels relative to that of nIII stimulation, suggesting that there is amplification of efferent drive at the ganglion. Time constants for constrictions ranged from 88 to 154 ms with relaxations occurring more slowly at 174-361 ms. These values for timing from in vitro are much faster than the time constant 1.66 min obtained for the light response in the intact animal. The rapid dynamics of pupil constriction observed here suggest that the slow PLR of the turtle observed in vivo is not due to limitations of the efferent pathway. Rather, the sluggish response probably results from photoreceptive mechanisms or central processing.

Do beliefs, coping, and catastrophizing independently predict functioning in patients with chronic pain?

Physical and psychosocial disability in patients with chronic pain have been shown to be associated with patients' pain-related beliefs, tendency to catastrophize, and pain coping strategy use. However, little is known about whether beliefs, catastrophizing, and coping strategies are independently associated with patient adjustment. Identification of specific beliefs, cognitive responses, and coping strategies strongly and independently associated with physical and psychosocial functioning would suggest the importance of targeting those variables for modification in treatment. One hundred sixty-nine patients entering a multidisciplinary pain treatment program completed measures of pain, beliefs, coping, catastrophizing, physical disability, and depression. Principal components analyses were used to create belief and coping components, which were then entered in multiple regression analyses predicting physical disability and depression. Belief scores significantly and independently predicted both physical disability and depression, after controlling for age, sex, pain intensity, catastrophizing, and coping. Coping scores significantly and independently predicted physical disability, but not depression, whereas catastrophizing independently predicted depression, but not physical disability. These findings suggest the importance of targeting specific pain-related beliefs and coping strategies, as well as catastrophizing, for modification in the treatment of patients with chronic pain.

Patient beliefs predict patient functioning: further support for a cognitive-behavioural model of chronic pain.

According to the cognitive-behavioral model of chronic pain, patient beliefs about their chronic pain influence their behavioral and psychological functioning. Previous correlational and longitudinal studies have supported this hypothesis. However, since previous research has relied almost exclusively on patient self-report to assess both beliefs and functioning, shared method variance may explain some of the relationships found. The aim of the current study was to replicate and extend previous research on the relationship between pain beliefs and patient functioning and behavior by assessing the latter based on three sources of information: patient report, spouse report and direct observation. A total of 121 patients with chronic pain completed self-report measures of beliefs and function. Their spouses completed a measure of patient pain behavior, and both participated in a protocol, from which patient pain behaviors were coded by trained observers. Previously reported relationships between patient beliefs about pain and patient-reported functioning were replicated. Measures of patient beliefs were more strongly associated with self-report measures of pain behaviors and functioning than with spouse and observer ratings of patient pain behaviors. However, significant associations between patient beliefs and both spouse- and observer-reported frequency of patient pain behaviors were found. These findings argue for the generalizability of the relationship found between patient beliefs and patient behaviors across assessment domains, and for the continued application of the cognitive-behavioral model to the understanding of patient adjustment to chronic pain.

Comparative reliability and validity of chronic pain intensity measures.

Reliable and valid measures of pain are essential for conducting research on chronic pain. The purpose of this longitudinal study was to compare the reliability and validity of several measures of pain intensity. One hundred twenty-three patients with chronic pain were administered telephone interview versions of 0-10 scales of current, worst, least and average pain, immediately prior to beginning a multidisciplinary treatment program. The measures were administered again to these subjects 2 weeks (n=108), 1 month (n=106) and 2 months (n=105) after the end of treatment. The validity (defined as ability to detect changes in pain intensity over the course of treatment up to the 2-month follow-up assessment) and reliability (defined as stability over time in the 2 months after treatment) of these four measures and of composite combinations of these measures were examined. Contrary to prediction, the composite measures did not show a statistically significant superiority to the individual ratings in terms of their ability to detect change in pain intensity from pre-treatment to various points after treatment. The composite scores did, however, show greater stability than did the individual ratings after treatment. The practical conclusions of this study are; (1), individual 0-10 pain intensity ratings have sufficient psychometric strengths to be used in chronic pain research, especially research that involves group comparison designs with relatively large sample sizes, but, (2), composites of 0-10 ratings may be more useful when maximal reliability is necessary, (e.g. in studies with relatively small sample sizes, or in clinical settings where monitoring of changes in pain intensity in individuals is needed).

Disseminated listeriosis presenting as acute hepatitis. Case reports and review of hepatic involvement in listeriosis.

We report three cases of disseminated listeriosis that presented as acute hepatitis characterized by striking increase of liver function test values and fever. Peak serum transaminases (SGOT) for each of three patients were 5,380, 2,350, and 443 mu/ml respectively. The correct diagnosis was not suspected in any of the patients until blood and cerebrospinal fluid cultures obtained routinely in the course of evaluation for fever grew Listeria monocytogenes. When antibiotic therapy was instituted, serum transaminase values plummeted in two patients; these two were eventually cured of their infection. The third patient succumbed to his infection; postmortem examination showed miliary abscesses of the liver which revealed L. monocytogenes. Review of the literature for previous reports of hepatic involvement in adult patients with listeriosis shows that hepatitis is an unusual mode of presentation. However, since we observed these three cases over a one-year period, we suspect this may not be an uncommon occurrence.

Correlates of improvement in multidisciplinary treatment of chronic pain.

Although multidisciplinary pain programs have been demonstrated to be effective, the processes of improvement have yet to be clarified. Cognitive-behavioral models posit that improvement is due, in part, to changes in patient pain beliefs and coping strategies. To test the relationships between treatment outcome and changes in beliefs and coping strategies, 94 chronic pain patients completed measures of physical and psychological functioning, health care utilization, pain beliefs, and use of pain coping strategies at admission and 3 to 6 months after inpatient pain treatment. Improved functioning and decreased health care use were associated with changes in both beliefs and cognitive coping strategies. However, changes in some coping strategies, such as exercise and use of rest, were not associated with improvement.

Changes in beliefs, catastrophizing, and coping are associated with improvement in multidisciplinary pain treatment.

To examine the associations between changes in cognitions and coping and multidisciplinary pain treatment outcomes, the authors had 141 patients with chronic pain complete measures of adjustment, beliefs, catastrophizing, and coping; in addition, their significant others rated patient physical functioning at pretreatment, posttreatment, and 6- and 12-month follow-ups. Decreases in guarding and resting and in the belief that pain signals damage were associated with decreases in patient disability. Increases in perceived control over pain and decreases in catastrophizing and in the belief that one is disabled were associated with decreases in self-reported patient disability, pain intensity, and depression. The results are consistent with the hypothesis, derived from cognitive-behavioral models of chronic pain, that the outcomes of multidisciplinary pain treatment are associated with changes in patient cognitions and coping responses.

Sequential analysis of chronic pain behaviors and spouse responses.

Social reinforcers such as spouse behaviors have been hypothesized to be important in maintaining chronic pain behavior. This study used direct observation to test whether solicitous and aggressive spouse behaviors systematically precede and follow patient pain behaviors. Fifty chronic pain patients and spouses and 33 control couples were videotaped performing specified tasks. Spouse solicitous behaviors were significantly more likely to precede and follow nonverbal pain behaviors, and nonverbal pain behaviors were significantly less likely to follow spouse aggressive behaviors in pain than in control couples. Within couples, spouse solicitous behaviors preceded and followed verbal and nonverbal pain behaviors beyond chance levels more often in pain than in control couples. Results support an operant conceptualization of factors maintaining chronic pain behaviors.

Creating Realistic Virtual Textures from Contact Acceleration Data.

Modern haptic interfaces are adept at conveying the large-scale shape of virtual objects, but they often provide unrealistic or no feedback when it comes to the microscopic details of surface texture. Direct texture-rendering challenges the state of the art in haptics because it requires a finely detailed model of the surface's properties, real-time dynamic simulation of complex interactions, and high-bandwidth haptic output to enable the user to feel the resulting contacts. This paper presents a new, fully realized solution for creating realistic virtual textures. Our system employs a sensorized handheld tool to capture the feel of a given texture, recording three-dimensional tool acceleration, tool position, and contact force over time. We reduce the three-dimensional acceleration signals to a perceptually equivalent one-dimensional signal, and then we use linear predictive coding to distill this raw haptic information into a database of frequency-domain texture models. Finally, we render these texture models in real time on a Wacom tablet using a stylus augmented with small voice coil actuators. The resulting virtual textures provide a compelling simulation of contact with the real surfaces, which we verify through a human subject study.

Self-report screening measures for depression in chronic pain patients.

Depression is prevalent among chronic pain patients, yet little is known about the ability of various self-report measures to detect this disorder in this population. This study investigated the relationship of several self-report depression scales (Beck Depression Inventory-standard and short forms, MMPI Depression, Depression subtle, and Depression obvious scales, and the Zung Self-Rating Depression Scale) to clinician DSM-III diagnoses of major depressive disorder in 40 chronic pain patients. Thirty percent of the Ss met criteria for major depression. Sensitivity and specificity values obtained for each scale are presented. The standard and short forms of the Beck Depression Inventory and the Zung Self-Rating Depression Scale showed good sensitivity and specificity and were comparable in detecting major depression in this sample.

Pharmacology of a new 1-oxa-beta-lactam (LY127935) in normal volunteers.

The pharmacokinetics of 1-oxa-beta-lactam (LY127935), a new semisynthetic beta-lactam antibiotic, was studied in four healthy adult volunteers (mean age of 27 years, mean body surface area +/- standard error [SE] of 1.87 +/- 0.08 m(2), and mean creatinine clearance +/- SE of 116 +/- 12 ml/min per 1.73 m(2)). Immediately after completion of a 1-g, 20-min intravenous (i.v.) infusion, the mean serum level +/- SE was 70.7 +/- 8.5 mug/ml. After a 1-g intramuscular (i.m.) injection, peak serum levels occurred from 30 min to 1 h, and the mean peak serum level +/- SE was 52.3 +/- 1.6 mug/ml. Beginning at 1 h, the serum concentrations after i.m. administration were higher than those after i.v. administration. At 8 h, the mean serum level +/- SE was 3.8 +/- 0.6 mug/ml after completion of the i.v. infusion and 4.8 +/- 0.7 mug/ml after the i.m. injection. The mean serum half-lives for the beta phase i.v. and i.m. administration were similar (2.3 +/- 0.7 h and 2.4 +/- 0.2 h, respectively). The mean apparent volume of distribution +/- SE was 16.6 +/- 1.9 liters per 1.73 m(2). The mean serum clearance +/- SE of LY127935 was 85.4 +/- 12.7 ml/min per 1.73 m(2), and the mean renal clearance +/- SE was 54.5 +/- 4.4 ml/min per 1.73 m.(2) Urine concentrations of LY127935 were at least 140 mug/ml in each volunteer during the first 12 h after i.m. or i.v. administration. The mean percentages of the dose recovered in the urine +/- SE within 2 h after i.v. or i.m. administration were similar (30 +/- 4 and 34 +/- 11, respectively). Only 67 +/- 3% and 75 +/- 13% were recovered in the urine within 24 h after i.v. and i.m. administration, respectively.

Effect of cimetidine and antacid on gastric microbial flora.

The effect of a standard regimen of cimetidine on the gastric flora of 20 male volunteers was studied in a double-blind manner and compared with the effects of a standard antacid regimen. Postprandial microbial titers in gastric aspirates were significantly higher at 4, 8, and 16 weeks of therapy in subjects taking antacids and at 4 weeks in subjects taking cimetidine when compared with their pretreatment titers. Although not significant, there was a tendency for fasting microbial titers to be higher in subjects receiving cimetidine as compared with pretreatment titers. The higher titers were primarily related to increases in survival of mouth flora (viridans streptococci and Neisseria spp.); Enterobacteriaceae and other nitrate-reducing organisms were unusual isolates. There was no significant difference in the total titers or types of organisms isolated when subjects taking cimetidine were compared with those taking antacid.

Lipid accumulation inRhodotorula glutinis on sugar cane molasses in single-stage continuous culture.

Microbial lipids produced byRhodotorula glutinis grown in continuous culture with molasses under nitrogen-limiting conditions were evaluated and the effects of growth rate on fatty acid composition were studied. As the growth rate decreased, cell biomass, lipid content and lipid yield gradually increased. The maximum lipid content recorded was 39% (w/w) of dry cell biomass at a dilution rate of 0.04 h(-1). The growth rate also affected fatty acid composition: oleic acid decreased with decreasing growth rate while stearic acid increased.

Variacion del flujo de leche materna durante la lactada. / Variations of milk flow during breast feeding

El presente estudio determina el volumen de leche materna ingerido por el recien nacido (0-28 dias) en 74 muestras en diferentes tiempos de lactada. El nino era pesado antes y luego a intervalo de tres minutos hasta alcanzar la saciedad o abandono de la succion. Las medidas se efectuaron para el periodo de leche calostral, transicional y madura.Se observo que existe un aumento significativo del volumen ingerido,cuando pasa del periodo calostral al de leche madura. Ademas se encontro que la ingestion mayor, entre un 79 y 80%, se realiza en los primeros 3 minutos. Al cambiarlo de seno, aumenta nuevamente el flujo de leche. Se plantea que este conocimiento podria ser de utilidad en el caso frecuente de disminucion de la secrecion lactea, cambiandolo de seno a los 3 o 4 minutos