Pain control following inguinal herniorrhaphy: current perspectives

Inguinal hernia repair is one of the most common surgeries performed worldwide. With the success of modern hernia repair techniques, recurrence rates have significantly declined, with a lower incidence than the development of chronic postherniorrhaphy inguinal pain (CPIP). The avoidance of CPIP is arguably the most important clinical outcome and has the greatest impact on patient satisfaction, health care utilization, societal cost, and quality of life. The etiology of CPIP is multifactorial, with overlapping neuropathic and nociceptive components contributing to this complex syndrome. Treatment is often challenging, and no definitive treatment algorithm exists. Multidisciplinary management of this complex problem improves outcomes, as treatment must be individualized. Current medical, pharmacologic, interventional, and surgical management strategies are reviewed

Experimental Correlation of Combined Heat and Mass Transfer for NH 3 -H 2 0 falling film absorption

vection. The main conclusion from this study is that the negative concentration gradient of the surface tension is a trigger for inducement of Marangoni convection before the additive solubility, while the imbalance of the surface tension and the interfacial tension is a trigger after the solubility limit. Acknowledgment The authors thank Mr. K. Iizuka, Tokyo University of Agriculture and Technology, for his experimental assistance. The authors acknowledge that this work has been partially funded by the Japan Science and Technology Corporation (JST). References Beutler, A., Greiter, I., Wagner, A., Hohhmann, L., Schreier, S., and Alefeld, G., 1996, "Surfactants and Fluid Properties," Int. J. Refrigeration, Vol. 19, No. 5, pp. 342-346. Chavepeyer, G" Salajan, M., Platten, J. K., and Smet, P., 1995, "InterfacialTension and Surface Adsorption in j-Heptanol/Water Systems," Journal of Colloid and Interface Science, Vol. 174, Daiguji, H,, Hihara, E., and Saito, T., 1997, "Mechanism of Absorption Enhancement by Surfactant," Int. J. Heat and Mass Transfer, Vol. 40, No. 8, pp. 1743-1752. Fujita, T., 1993, "Falling Liquid Films in Absorption Machines," Int. J. Refrigeration, Vol. 16, No. 4, pp. 282-294. Hihara, E" and Saito, T., 1993 Journal of Heat Transfer TL = temperature of the fluid far away from the plate t' = time t R = reference time u = velocity of the fluid UD = reference velocity at' = frequency X,, = distance of the transition point from the leading edge |3 = coefficient of volume expansion p = density e = amplitude (constant) 9 = nondimensional temperature u = nondimensional velocity i = y-i Introduction Transient laminar-free convection flow past an infinite vertical plate under different plate conditions was studied by many researchers. The first closed-form solutions for Prandtl number Pr = 1.0 in case of a step change in wall temperature with time was derived by Illingworth (1950) and for Pr # 1.0, he derived the solution in integral form. Siegel (1958) studied the unsteady freeconvection flow past a semi-infinite vertical plate under stepchange in wall temperature or surface heat flux by employing the momentum integral method. Experimental evidence for such a situation was presented by Goldstein and Eckert (1960). For a semi-infinite vertical plate, unsteady free-convection flow was studied analytically b

Properties of Rubble-Pile Asteroid (101955) Bennu from OSIRIS-REx Imaging and Thermal Analysis

Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. Using images and thermal data from NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft, we show that asteroid (101955) Bennu's surface is globally rough, dense with boulders, and low in albedo. The number of boulders is surprising given Bennu's moderate thermal inertia, suggesting that simple models linking thermal inertia to particle size do not adequately capture the complexity relating these properties. At the same time, we find evidence for a wide range of particle sizes with distinct albedo characteristics. Our findings imply that ages of Bennu's surface particles span from the disruption of the asteroid's parent body (boulders) to recent in situ production (micrometre-scale particles)

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids

Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth

Posttraumatic stress disorder influences the nociceptive and intrathecal cytokine response to a painful stimulus in combat veterans

ObjectiveAlthough posttraumatic stress disorder (PTSD) and chronic pain frequently occur in tandem, the pathophysiological mechanisms mediating this comorbidity are poorly understood. Because excessive inflammation occurs in both conditions, we examined the cerebrospinal fluid (CSF) concentrations of inflammatory response mediators interleukin 1-beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor-alpha (TNFα) and interleukin 10 (IL-10) after prolonged suprathreshold pain stimulus in 21 male combat veterans; 10 with PTSD and 11 combat controls (CC).MethodsAfter completing baseline quantitative sensory testing (QST) and psychological profiling, all patients received an injection of capsaicin into the quadriceps muscle. Spontaneously reported pain was measured for 30min after the capsaicin injection. The evoked pain measure of temporal summation was tested between 70 and 110min post capsaicin injection. Inflammatory (IL-1β, IL-6, IL-8 TNFα) and anti-inflammatory (IL-10) CSF cytokines were measured before (baseline) and after capsaicin injection over a time frame of 110min.ResultsFollowing intramuscular capsaicin injection, pro-inflammatory cytokines [TNFα, IL-6, IL-8] significantly increased (percent rise from baseline) in both groups, whereas IL-1β significantly increased in the PTSD group only. The anti-inflammatory cytokine IL-10 showed an immediate (within 10min) increase in the CC group; however, the IL-10 increase in the PTSD group was delayed and not consistently elevated until 70min post injection.ConclusionThese findings show significant central nervous system (CNS) differences in the inflammatory response to a deep pain stimulus in combat veterans with and without PTSD. They support the concept that abnormally elevated neuroinflammatory response to pain stimuli may be one CNS mechanism accounting for the high co-occurrence of PTSD and pain