Examining the side effects of sucrose for pain relief in preterm infants: a case-control study

Sucrose solution is recommended as relevant pain relief management in neonates during acute painful procedures; however, only a few studies have analyzed the potentially adverse effects of sucrose administration to preterm neonates. The goal of this study was to examine the potential side effects of sucrose for pain relief in preterm infants, assessing feeding and weight gain during hospitalization and their feeding patterns postdischarge. The study sample consisted of 43 preterm neonates divided into two groups: a sucrose group (SG, n=18) and a control group (CG, n=25) in which no sucrose was administered. The SG received 0.5 mL/kg 25% oral sucrose for 2 min prior to all acute painful procedures during three consecutive days. A prospective review of medical charts was performed for all samples. The study was done prior to implementation of the institutional sucrose guidelines as a routine service, and followed all ethical requirements. There were no statistically significant differences between groups in terms of weight gain, length of stay with orogastric tubes, and parenteral feeding. Postdischarge, infant nutritional intake included feeding human milk to 67% of the SG and 74% of the CG. There were no statistically significant differences between groups regarding human milk feeding patterns postdischarge. Neonate feeding patterns and weight gain were unaffected following the short-term use of sucrose for pain relief.

Relationship of inflammatory markers and pain in patients with head and neck cancer prior to anticancer therapy

Pain is a common symptom in patients with cancer, including those with head and neck cancer (HNC). While studies suggest an association between chronic inflammation and pain, levels of inflammatory cytokines, such as C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α), have not been correlated with pain in HNC patients who are not currently undergoing anticancer treatment. The purpose of this study was to examine the relationship between these inflammatory markers and perceived pain in HNC patients prior to anticancer therapy. The study group consisted of 127 HNC patients and 9 healthy controls. Pain was assessed using the Brief Pain Inventory (BPI), and serum levels of CRP and TNF-α were determined using the particle-enhanced turbidimetric immunoassay (PETIA) and ELISA techniques, respectively. Patients experiencing pain had significantly higher levels of CRP (P<0.01) and TNF-α (P<0.05) compared with controls and with patients reporting no pain. There were significantly positive associations between pain, CRP level, and tumor stage. This is the first study to report a positive association between perceived pain and CRP in HNC patients at the time of diagnosis. The current findings suggest important associations between pain and inflammatory processes in HNC patients, with potential implications for future treatment strategies.

Prevalence and conditions associated with chronic pelvic pain in women from São Luís, Brazil

The objective of the present study was to estimate the prevalence of chronic pelvic pain in the community of São Luís, capital of the State of Maranhão, Northeastern Brazil, and to identify independent conditions associated with it. A cross-sectional study was conducted, including a sample of 1470 women older than 14 years predominantly served by the public health system. The interviews were held in the subject's home by trained interviewers not affiliated with the public health services of the municipality. The homes were visited at random according to the city map and the prevalence of the condition was estimated. To identify the associated conditions, the significant variables (P=0.10) were selected and entered in a multivariate analysis model. Data are reported as odds ratio and 95% confidence interval, with the level of significance set at 0.05. The prevalence of chronic pelvic pain was 19.0%. The independent conditions associated with this diagnosis were: dyspareunia (OR=3.94), premenopausal status (OR=2.95), depressive symptoms (OR=2.33), dysmenorrhea (OR=1.77), smoking (OR=1.72), irregular menstrual flow (OR=1.62), and irritative bladder symptoms (OR=1.90). The prevalence of chronic pelvic pain in Sao Luís is high and is associated with the conditions cited above. Guidelines based on prevention and/or early identification of risk factors may reduce the prevalence of chronic pelvic pain in São Luís, Brazil.

The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

It is currently accepted that superoxide anion (O2•−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

Reduction of blood nitric oxide levels is associated with clinical improvement of the chronic pelvic pain related to endometriosis

The objective of this prospective study was to determine the plasma levels of nitric oxide (NO) in women with chronic pelvic pain secondary to endometriosis (n=24) and abdominal myofascial pain syndrome (n=16). NO levels were measured in plasma collected before and 1 month after treatment. Pretreatment NO levels (μM) were lower in healthy volunteers (47.0±12.7) than in women with myofascial pain (64.2±5.0, P=0.01) or endometriosis (99.5±12.9, P<0.0001). After treatment, plasma NO levels were reduced only in the endometriosis group (99.5±12.9 vs 61.6±5.9, P=0.002). A correlation between reduction of pain intensity and reduction of NO level was observed in the endometriosis group [correlation = 0.67 (95%CI = 0.35 to 0.85), P<0.0001]. Reduction of NO levels was associated with an increase of pain threshold in this group [correlation = -0.53 (-0.78 to -0.14), P<0.0001]. NO levels appeared elevated in women with chronic pelvic pain diagnosed as secondary to endometriosis, and were directly associated with reduction in pain intensity and increase in pain threshold after treatment. Further studies are needed to investigate the role of NO in the pathophysiology of pain in women with endometriosis and its eventual association with central sensitization.

Hypertension is associated with greater heat exchange during exercise recovery in a hot environment

Individuals with systemic arterial hypertension have a higher risk of heat-related complications. Thus, the aim of this study was to examine the thermoregulatory responses of hypertensive subjects during recovery from moderate-intensity exercise performed in the heat. A total of eight essential hypertensive (H) and eight normotensive (N) male subjects (age=46.5±1.3 and 45.6±1.4 years, body mass index=25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure=98.0±2.8 and 86.0±2.3 mmHg, respectively) rested for 30 min, performed 1 h of treadmill exercise at 50% of maximal oxygen consumption, and rested for 1 h after exercise in an environmental chamber at 38°C and 60% relative humidity. Skin and core temperatures were measured to calculate heat exchange parameters. Mean arterial pressure was higher in the hypertensive than in the normotensive subjects throughout the experiment (P<0.05, unpaired t-test). The hypertensive subjects stored less heat (H=-24.23±3.99 W·m−2vs N=-13.63±2.24 W·m−2, P=0.03, unpaired t-test), experienced greater variations in body temperature (H=-0.62±0.05°C vsN=-0.35±0.12°C, P=0.03, unpaired t-test), and had more evaporated sweat (H=-106.1±4.59 W·m−2vs N=-91.15±3.24 W·m−2, P=0.01, unpaired t-test) than the normotensive subjects during the period of recovery from exercise. In conclusion, essential hypertensive subjects showed greater sweat evaporation and increased heat dissipation and body cooling relative to normotensive subjects during recovery from moderate-intensity exercise performed in hot conditions.

Inflammatory cytokines and plasma redox status responses in hypertensive subjects after heat exposure

Hypertension is characterized by a pro-inflammatory status, including redox imbalance and increased levels of pro-inflammatory cytokines, which may be exacerbated after heat exposure. However, the effects of heat exposure, specifically in individuals with inflammatory chronic diseases such as hypertension, are complex and not well understood. This study compared the effects of heat exposure on plasma cytokine levels and redox status parameters in 8 hypertensive (H) and 8 normotensive (N) subjects (age: 46.5±1.3 and 45.6±1.4 years old, body mass index: 25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure: 98.0±2.8 and 86.0±2.3 mmHg, respectively). They remained at rest in a sitting position for 10 min in a thermoneutral environment (22°C) followed by 30 min in a heated environmental chamber (38°C and 60% relative humidity). Blood samples were collected before and after heat exposure. Plasma cytokine levels were measured using sandwich ELISA kits. Plasma redox status was determined by thiobarbituric acid reactive substances (TBARS) levels and ferric reducing ability of plasma (FRAP). Hypertensive subjects showed higher plasma levels of IL-10 at baseline (P<0.05), although levels of this cytokine were similar between groups after heat exposure. Moreover, after heat exposure, hypertensive individuals showed higher plasma levels of soluble TNF receptor (sTNFR1) and lower TBARS (P<0.01) and FRAP (P<0.05) levels. Controlled hypertensive subjects, who use angiotensin-converting-enzyme inhibitor (ACE inhibitors), present an anti-inflammatory status and balanced redox status. Nevertheless, exposure to a heat stress condition seems to cause an imbalance in the redox status and an unregulated inflammatory response.

Effects of intracutaneous injections of sterile water in patients with acute low back pain: a randomized, controlled, clinical trial

Intracutaneous sterile water injection (ISWI) is used for relief of low back pain during labor, acute attacks of urolithiasis, chronic neck and shoulder pain following whiplash injuries, and chronic myofascial pain syndrome. We conducted a randomized, double-blinded, placebo-controlled trial to evaluate the effect of ISWI for relief of acute low back pain (aLBP). A total of 68 patients (41 females and 27 males) between 18 and 55 years old experiencing aLBP with moderate to severe pain (scores ≥5 on an 11-point visual analogue scale [VAS]) were recruited and randomly assigned to receive either ISWIs (n=34) or intracutaneous isotonic saline injections (placebo treatment; n=34). The primary outcome was improvement in pain intensity using the VAS at 10, 45, and 90 min and 1 day after treatment. The secondary outcome was functional improvement, which was assessed using the Patient-Specific Functional Scale (PSFS) 1 day after treatment. The mean VAS score was significantly lower in the ISWI group than in the control group at 10, 45, and 90 min, and 1 day after injection (P<0.05, t-test). The mean increment in PSFS score of the ISWI group was 2.9±2.2 1 day after treatment, while that in the control group was 0.9±2.2. Our study showed that ISWI was effective for relieving pain and improving function in aLBP patients at short-term follow-up. ISWI might be an alternative treatment for aLBP patients, especially in areas where medications are not available, as well as in specific patients (e.g., those who are pregnant or have asthma), who are unable to receive medications or other forms of analgesia because of side effects.

Effect of heat input on the mechanical properties of welded joints in high strength steels

Experiments were carried out to determine the properties of the welded joints in 8mm thick high-strength steels produced by quenching and tempering and thermomechanical rolling with accelerated cooling (tensile strength 821–835 MPa). The dependence of the strength, elongation, hardness, impact energy and crack opening displacement on the heat input in the range 1.0–0.7 kJ mm21 was determined. The results show that the dependence of the strength of the welded joints decreases and that of the elongation increases. The heat input has only a slight effect on the impact energy and crack opening displacement in the heat-affected zone.

A Bayesian Approach for Forecasting Heat Load in a District Heating System

The growing population in cities increases the energy demand and affects the environment by increasing carbon emissions. Information and communications technology solutions which enable energy optimization are needed to address this growing energy demand in cities and to reduce carbon emissions. District heating systems optimize the energy production by reusing waste energy with combined heat and power plants. Forecasting the heat load demand in residential buildings assists in optimizing energy production and consumption in a district heating system. However, the presence of a large number of factors such as weather forecast, district heating operational parameters and user behavioural parameters, make heat load forecasting a challenging task. This thesis proposes a probabilistic machine learning model using a Naive Bayes classifier, to forecast the hourly heat load demand for three residential buildings in the city of Skellefteå, Sweden over a period of winter and spring seasons. The district heating data collected from the sensors equipped at the residential buildings in Skellefteå, is utilized to build the Bayesian network to forecast the heat load demand for horizons of 1, 2, 3, 6 and 24 hours. The proposed model is validated by using four cases to study the influence of various parameters on the heat load forecast by carrying out trace driven analysis in Weka and GeNIe. Results show that current heat load consumption and outdoor temperature forecast are the two parameters with most influence on the heat load forecast. The proposed model achieves average accuracies of 81.23 % and 76.74 % for a forecast horizon of 1 hour in the three buildings for winter and spring seasons respectively. The model also achieves an average accuracy of 77.97 % for three buildings across both seasons for the forecast horizon of 1 hour by utilizing only 10 % of the training data. The results indicate that even a simple model like Naive Bayes classifier can forecast the heat load demand by utilizing less training data.

Benefits of gas driven ground source heat pump systems

This thesis studies energy efficiencies and technical properties of gas driven ground source heat pumps and pump systems. The research focuses on two technologies: gas engine driven compressor heat pump and thermally driven gas absorption heat pump. System consist of a gas driven compressor or absorption ground source heat pump and a gas condensing boiler, which covers peak load. The reference system is a standard electrically powered compressor heat pump with electric heating elements for peak load. The systems are compared through primary energy ratios. Coefficient of performances of different heat pump technologies are also compared. At heat pump level, gas driven heat pumps are having lower coefficient of performances as compared with corresponding electric driven heat pump. However, gas heat pumps are competitive when primary energy ratios, where electricity production losses are counted in, are compared. Technically, gas heat pumps can potentially achieve a slightly higher temperatures with greater total energy efficiency as compared to the electric driven heat pump. The primary energy ratios of gas heat pump systems in relation to EHP-system improves when the share of peak load increases. Electric heat pump system's overall energy efficiency is heavily dependent on the electricity production efficiency. Economy as well as CO2-emissions were not examined in this thesis, which however, would be good topics for further study.

Effects of Fin Parameters on Gas-Side Heat Transfer Performance of H-Type Finned Tube Bundle in a Waste Heat Recovery Boiler

Alfa Laval Aalborg Oy designs and manufactures waste heat recovery systems utilizing extended surfaces. The waste heat recovery boiler considered in this thesis is a water-tube boiler where exhaust gas is used as the convective heat transfer medium and water or steam flowing inside the tubes is subject to cross-flow. This thesis aims to contribute to the design of waste heat recovery boiler unit by developing a numerical model of the H-type finned tube bundle currently used by Alfa Laval Aalborg Oy to evaluate the gas-side heat transfer performance. The main objective is to identify weaknesses and potential areas of development in the current H-type finned tube design. In addition, numerical simulations for a total of 15 cases with varying geometric parameters are conducted to investigate the heat transfer and pressure drop performance dependent on H-type fin geometry. The investigated geometric parameters include fin width and height, fin spacing, and fin thickness. Comparison between single and double tube type configuration is also conducted. Based on the simulation results, the local heat transfer and flow behaviour of the H-type finned tube is presented including boundary layer development between the fins, the formation of recirculation zone behind the tubes, and the local variations of flow velocity and temperature within the tube bundle and on the fin surface. Moreover, an evaluation of the effects of various fin parameters on heat transfer and pressure drop performance of H-type finned tube bundle has been provided. It was concluded that from the studied parameters fin spacing and fin width had the most significant effect on tube bundle performance and the effect of fin thickness was the least important. Furthermore, the results suggested that the heat transfer performance would increase due to enhanced turbulence if the current double tube configuration is replaced with single tube configuration, but further investigation and experimental measurements are required in order to validate the results.

Optimizing the Performance of a Heat Exchanger Network

This research is the continuation and a joint work with a master thesis that has been done in this department recently by Hemamali Chathurangani Yashika Jayathunga. The mathematical system of the equations in the designed Heat Exchanger Network synthesis has been extended by adding a number of equipment; such as heat exchangers, mixers and dividers. The solutions of the system is obtained and the optimal setting of the valves (Each divider contains a valve) is calculated by introducing grid-based optimization. Finding the best position of the valves will lead to maximization of the transferred heat in the hot stream and minimization of the pressure drop in the cold stream. The aim of the following thesis will be achieved by practicing the cost optimization to model an optimized network.

Introducing the concept of critical Fo in batch heat processing

The determination of the sterilization value for low acid foods in retorts includes a critical evaluation of the factory's facilities and utilities, validation of the heat processing equipment (by heat distribution assays), and finally heat penetration assays with the product. The intensity of the heat process applied to the food can be expressed by the Fo value (sterilization value, in minutes, at a reference temperature of 121.1 °C, and a thermal index, z, of 10 °C, for Clostridium botulinum spores). For safety reasons, the lowest value for Fo is frequently adopted, being obtained in heat penetration assays as indicative of the minimum process intensity applied. This lowest Fo value should always be higher than the minimum Fo recommended for the food in question. However, the use of the Fo value for the coldest can fail to statistically explain all the practical occurrences in food heat treatment processes. Thus, as a result of intense experimental work, we aimed to develop a new focus to determine the lowest Fo value, which we renamed the critical Fo. The critical Fo is based on a statistical model for the interpretation of the results of heat penetration assays in packages, and it depends not only on the Fo values found at the coldest point of the package and the coldest point of the equipment, but also on the size of the batch of packages processed in the retort, the total processing time in the retort, and the time between CIPs of the retort. In the present study, we tried to explore the results of physical measurements used in the validation of food heat processes. Three examples of calculations were prepared to illustrate the methodology developed and to introduce the concept of critical Fo for the processing of canned food.

Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

The sorption behavior of dry products is generally affected by the drying method. The sorption isotherms are useful to determine and compare thermodynamic properties of passion fruit pulp powder processed by different drying methods. The objective of this study is to analyze the effects of different drying methods on the sorption properties of passion fruit pulp powder. Passion fruit pulp powder was dehydrated using different dryers: vacuum, spray dryer, vibro-fluidized, and freeze dryer. The moisture equilibrium data of Passion Fruit Pulp (PFP) powders with 55% of maltodextrin (MD) were determined at 20, 30, 40 and 50 ºC. The behavior of the curves was type III, according to Brunauer's classification, and the GAB model was fitted to the experimental equilibrium data. The equilibrium moisture contents of the samples were little affected by temperature variation. The spray dryer provides a dry product with higher adsorption capacity than that of the other methods. The vibro-fluidized bed drying showed higher adsorption capacity than that of vacuum and freeze drying. The vacuum and freeze drying presented the same adsorption capacity. The isosteric heats of sorption were found to decrease with increasing moisture content. Considering the effect of drying methods, the highest isosteric heat of sorption was observed for powders produced by spray drying, whereas powders obtained by vacuum and freeze drying showed the lowest isosteric heats of sorption.