Constant Temperature Water Research Articles

Optimizing the factors which modify thermal enhancement of melphalan in a spontaneous murine tumor

Hyperthermia enhances the cytotoxicity of some chemotherapeutic agents. Both clinical and laboratory studies suggest melphalan may be an important drug when hyperthermia is added to chemotherapy treatments. Factors that may modify the thermal enhancement of melphalan were studied to optimize its clinical use with hyperthermia. The tumor studied was an early-generation isotransplant of a spontaneous C3Hf/Sed mouse fibrosarcoma, Fsa-II. All studies were performed under supervision of the Animal Care and Use Committee. Hyperthermia was administered by immersing the tumor-bearing foot into a constant temperature water bath. Four factors were studied: duration of hyperthermia, sequencing of hyperthermia and melphalan, intensity of hyperthermia, and tumor size. To study duration of hyperthermia tumors were treated at 41.5 degrees C for 30 or 90 min immediately after intraperitoneal administration of melphalan. For sequencing of hyperthermia and melphalan, animals received hyperthermia treatment of tumors for 30 min at 41.5 degrees C immediately after drug administration, both immediately and 3 h after administration of drug or only at 3 h after administration of drug. Intensity of hyperthermia was studied using heat treatment of tumors for 30 min at 41.5 or 43.5 degrees C immediately following drug administration. Effect of tumor size was studied by delaying experiments until three times the tumor volume (113 mm3) was observed. Treatment of tumors was for 30 min at 41.5 degrees C immediately following drug administration. Tumor response was studied by the mean tumor growth time. Hyperthermia in the absence of melphalan had a small but significant effect on tumor growth time at 43.5 degrees C but not at 41.5 degrees C. Hyperthermia at 41.5 degrees C immediately after melphalan administration doubled mean tumor growth time at 30 min and caused a threefold increase at 90 min (P=0.0002) when compared to tumors treated with melphalan alone at room temperature. Application of hyperthermia for one-half hour immediately following drug administration was the most effective in delaying tumor growth. No significant difference in mean tumor growth time was observed with an increase in temperature from 41.5 to 43.5 degrees C. For large tumors heat alone and melphalan alone caused a moderate increase in tumor growth delay. These effects in large tumors were greatly increased by a combination of chemotherapy and hyperthermia. From our data it would appear that the administration of intraperitoneal melphalan immediately prior to 90 min of heat at 41.5 degrees C may optimize anti-neoplastic activity. These data may be useful in formulating clinical protocols in which melphalan and heat are combined.

District heating system design for a university campus

İzmir Institute of Technology campus is in use since 2000 and still under development. At present, heating is provided by individual fuel boilers. On the other hand, the campus has a geothermal resource in its borders with a temperature of 33 °C. Because of this low geothermal fluid temperature; heat pump district heating system is considered for the campus. As an alternative, fuel boiler district heating system is studied. Each heating system is simulated using hourly outdoor temperature data. For the simulations, a control system with constant flow rate and variable return water temperature is used and the main control parameter is the indoor temperature. Various heating regime alternatives have been studied for heat pump district heating system for the various condenser outlet temperature and geothermal fluid flow rate, and two of these alternatives are given in this study. Furthermore, economic analysis has also been done for each heating system alternative based on investment and operational costs. Results indicate that heat pump district heating system has the highest investment but lowest operational cost. The alternatives are evaluated according to internal rate of return method, which shows the profit of the investment and resulted that, the heat pump district heating system has minimum 3.02% profit comparing with the fuel boiler district heating system at the end of the 20-year period.

Assessing laser-tissue damage with bioluminescent imaging

Effective medical laser procedures are achieved by selecting laser parameters that minimize undesirable tissue damage. Traditionally, human subjects, animal models, and monolayer cell cultures have been used to study wound healing, tissue damage, and cellular effects of laser radiation. Each of these models has significant limitations, and consequently, a novel skin model is needed. To this end, a highly reproducible human skin model that enables noninvasive and longitudinal studies of gene expression was sought. In this study, we present an organotypic raft model (engineered skin) used in combination with bioluminescent imaging (BLI) techniques. The efficacy of the raft model was validated and characterized by investigating the role of heat shock protein 70 (hsp70) as a sensitive marker of thermal damage. The raft model consists of human cells incorporated into an extracellular matrix. The raft cultures were transfected with an adenovirus containing a murine hsp70 promoter driving transcription of luciferase. The model enables quantitative analysis of spatiotemporal expression of proteins using BLI. Thermal stress was induced on the raft cultures by means of a constant temperature water bath or with a carbon dioxide (CO2) laser (lambda=10.6 microm, 0.679 to 2.262 Wcm2, cw, unfocused Gaussian beam, omegaL=4.5 mm, 1 min exposure). The bioluminescence was monitored noninvasively with an IVIS 100 Bioluminescent Imaging System. BLI indicated that peak hsp70 expression occurs 4 to 12 h after exposure to thermal stress. A minimum irradiance of 0.679 Wcm2 activated the hsp70 response, and a higher irradiance of 2.262 Wcm2 was associated with a severe reduction in hsp70 response due to tissue ablation. Reverse transcription polymerase chain reaction demonstrated that hsp70 mRNA levels increased with prolonged heating exposures. Enzyme-linked immunosorbent protein assays confirmed that luciferase was an accurate surrogate for hsp70 intracellular protein levels. Hematoxylin and eosin stains verified the presence of the thermally denatured tissue regions. Immunohistochemical analyses confirmed that maximal hsp70 expression occurred at a depth of 150 microm. Bioluminescent microscopy was employed to corroborate these findings. These results indicate that quantitative BLI in engineered tissue equivalents provides a powerful model that enables sequential gene expression studies. Such a model can be used as a high throughput screening platform for laser-tissue interaction studies.

Effect of temperature and α-irradiation on gas permeability for polymeric membrane

In the present study the polyethersulphone (PES) membranes of thickness (35 ±2) μm were prepared by solution cast method. The permeability of these membranes was calculated by varying the temperature and by irradiation of α ions. For the variation of temperature, the gas permeation cell was dipped in a constant temperature water bath in the temperature range from 303–373 K, which is well below the glass transition temperature (498 K). The permeability of H2 and CO2 increased with increasing temperature. The PES membrane was exposed by a-source (95Am241) of strength (1 μ Ci) in vacuum of the order of 10−6 torr, with fluence 2.7 × 107 ions/cm2. The permeability of H2 and CO2 has been observed for irradiated membrane with increasing etching time. The permeability increases with increasing etching time for both gases. There was a sudden change in permeability for both the gases when observed at 18 min etching. At this stage the tracks are visible with optical instrument, which confirms that the pores are generated. Most of pores seen in the micrograph are circular cross-section ones.

Low temperature humidification dehumidification desalination process

The humidification dehumidification desalination process is viewed as a promising technique for small capacity production plants. The process has several attractive features, which include operation at low temperature, ability to utilize sustainable energy sources, i.e. solar and geothermal, and requirements of low technology level. This paper evaluates the characteristics of the humidification dehumidification desalination process as a function of operating conditions. A small capacity experimental system is used to evaluate the process characteristics as a function of the flow rate of the water and air streams, the temperature of the water stream and the temperature of the cooling water stream. The experimental system includes a packed humidification column, a double pipe glass condenser, a constant temperature water circulation tank and a chiller for cooling water. The water production is found to depend strongly on the hot water temperature. Also, the water production is found to increase upon the increase of the air flow rate and the decrease of the cooling water temperature. The measured air and water temperatures, air relative humidity and the flow rates are used to calculate the air side mass transfer coefficient and the overall heat transfer coefficient. Measured data are found to be consistent with previous literature results.

Effects of liquid VOC concentration and salt content on partitioning equilibrium of hydrophilic VOC at air–sweat interface

Volatile organic compounds (VOCs) must initially be absorbed by sweat on the surface of skin for human VOC dermal exposure . The partitioning equilibrium at the air–sweat interface is given by p c = C g * / C L , where p c is the partitioning coefficient, and C g * is the gaseous concentration in equilibrium with the aqueous VOC concentration ( C L ) at a constant water temperature ( T w ). A series of thermodynamic functions of C g * ( C L , T W ) are presented, as well as the values of p c , and the heat of gaseous–liquid phase transfer (Δ H tr ) for tested VOCs, including iso-propanol (IPA, C L =12–120 mg L −1 ) and methyl ethyl ketone (MEK, C L =10–80 mg L −1 ) to determine the effects of liquid VOC concentration and salt contents of sweat on p c of hydrophilic VOCs. Experimental data reveal that the p c values of IPA and MEK drop as the liquid VOC concentrations increasing from 10 to 120 mg L −1 . However, sodium salt content in human sweat (sodium chloride and sodium lactate) induces the effect of salt, indicating the increase in p c . Notably, neither urea nor ammonia in human sweat increase p c . Artificial sweat, consisting of sodium chloride 0.47%, urea 0.05%, ammonia 0.004% and sodium lactate 0.6%, was used to evaluate the increase in the p c values of IPA and MEK. The liquid VOC concentration effect simultaneously develops together with the salt effect on the partition at the interface of air–sweat for hydrophilic VOC solutions. The p c values of IPA for artificial sweat decrease as much as 32.5% as C L increases from 12 to 120 mg L −1 at 300 K, and those of MEK drop by as much as 70.9% as C L increases from 10 to 80 mg L −1 at 300 K. This investigation provides a basis for elucidating the assessment of human dermal exposure to hydrophilic VOCs.

A modified method for evaluation of materials containing volatile corrosion inhibitor

A systematic research on a modified method that was developed to evaluate the effectiveness of volatile corrosion inhibitor(VCI) materials was carried out. The metal specimen in size of 50 mm × 25 mm × 2 mm was level mounted on the top of a beaker by transparent adhesive tape and the assembly was placed in a constant temperature water bath and kept at approximately 40 °C to accelerate the vaporization of VCI and distilled water, which was placed at the bottom of the beaker at the same time. The experimental results show that the reproducibility of rust appearance and corrosion rate calculated by specimen’s mass loss is perfect. The outstanding characteristic of the rust appearance based on different VCI formula is discovered that is very important in studying the mechanism of VCI and the synergism of chemical reagent. The accelerated ratio is increased greatly as compared with the traditional method and the value is approximately 15 as compared with Shijiazhuang atmospheric environment corrosion test. The modified method is suitable for formula screening test and quick effectiveness evaluation of VCI materials.

SOFTENING KINETICS OF COOKED DRY BEANS AT TEMPERATURES BELOW 100C

ABSTRACT New value‐added dry bean products, such as sugar‐coated beans, require a shorter cooking time (15–30 min) and lower temperature (under 100C) than typical canned beans. Michigan bean classes navy, great white northern, small white, small red, dark red kidney, light red kidney, vine cranberry, bush cranberry, pinto and black beans were cooked at constant water temperatures of 90, 95 and 99C for 5–120 min. Isothermal rate constants for texture were estimated at each temperature for each bean class based on a modified first‐order model and an n th ‐order model. Heat transfer coefficients were estimated using aluminum beans and lumped capacity analysis. Isothermal parameters (rate constant and activation energy) and a nonisothermal parameter (activation energy) were used to predict texture from dynamic‐temperature experiments. The first‐order model (isothermal) was accurate up to 30 min, but was not appropriate for time greater than 30 min. The n th ‐order was considered superior to the modified first‐order model, because only three rather than four parameters needed to be estimated for similar accuracy. The nonisothermal method can save experimental time compared with the isothermal method, because additional experiments at different constant temperatures are unnecessary. A nomograph of equivalent heating time versus constant heating temperature was shown as a useful tool for process design.

Disparate effects of constant and annually-cycling daylength and water temperature on reproductive maturation of striped bass ( Morone saxatilis)

Adult striped bass ( Morone saxatilis) were exposed to various combinations of constant or anually-cycling daylength and water temperature. Constant conditions (15 h days, 18 °C) were those normally experienced at spawning and cycling conditions simulated natural changes at Chesapeake Bay latitude. Females exposed to constant long (15 h) days and cycling water temperature (TEMPERATURE group) had blood plasma levels of sex steroids (testosterone [T] and estradiol-17β [E 2]) and vitellogenin (Vg), and profiles of oocyte growth, that were nearly identical to those of females held under a natural photothermal cycle (CONTROL group). Several fish from these two groups were induced to spawn fertile eggs. Females constantly exposed to warm water (18 °C), with or without a natural photoperiod cycle (PHOTOPERIOD and STATIC groups, respectively), had diminished circulating levels of gonadal steroid hormones and Vg, impaired deposition of yolk granules in their ooplasm, and decreased oocyte growth, and they underwent premature ovarian atresia. Males exposed to cycling water temperature (CONTROL and TEMPERATURE groups) spermiated synchronously during the natural breeding season, at which time they also had had high plasma androgen (T and 11-ketotestosterone [11-KT]) levels. The timing of spermiation was highly asynchronous among males in groups of fish held constantly at 18 °C (STATIC and PHOTOPERIOD groups) and this asynchrony was associated with diminished plasma androgen levels. Termination of spermiation by males exposed to cycling water temperature coincided with a sharp decline in levels of plasma androgens about a month after water temperature rose above 18 °C. In contrast, most males held constantly at 18 °C sustained intermediate levels of plasma androgens and spermiated until the end of the study in late July. The annual cycle of water temperature clearly plays a prominent role in the initiation, maintenance, and termination of the striped bass reproductive cycle. In females, a decrease in water temperature below values experienced at spawning appears to be required for vitellogenesis and oocyte growth to proceed normally. Constant exposure of males to spawning temperature disrupts synchronous spermiation but also delays testicular regression, which may be useful for spawning fish after the natural reproductive season.

SU-FF-T-242: Evaluation of Implantable MOSFET Dosimeters for Conventional and Intraoperative Radiation Therapy

Purpose: To test the applicability and reliability of the manufacturer's calibration of implantable MOSFET dosimeters for use under differing clinical conditions. These include conventional radiation therapy and intraoperative radiation therapy, where the need for sterilizable, wireless telemetric sensors may make these detectors the best candidates for in vivo dosimetry. Method and Materials: The implantable dosimeters were manufactured and factory calibrated by Sicel Technologies, Inc. We tested these dosimeters for conventional radiotherapy beams, where the detectors were placed in a phantom and exposed to 20 treatment fractions with daily doses of 1, 2, or 4 Gy. We also tested the detectors for use in HDR-IORT, where the detectors were placed in a constant-temperature (37°C) water phantom and irradiated with an HDR Ir-192 source with single treatment fractions of 10, 12.5, or 15 Gy. Results: Under calibration conditions with conventional radiotherapy beams, we found the dose measured by the detectors using the manufacturer's calibration to be within ± 3% of the delivered dose, with a standard deviation of 2%. Preliminary results support the robustness of the calibration for conventional radiotherapy beams with both higher and lower daily doses, with an increase in error as the daily dose deviates from the calibrated dose. When an HDR Ir-192 source was used, the measured dose showed a linear deviation from the delivered dose due to differences in energy, dose rate, and total dose per fraction. These results suggest the need for additional correction factors when these detectors are used for HDR-IORT and most likely also for IOERT. Conclusion: We have verified the manufacturer's calibration of these dosimeters for conventional radiotherapy. With additional correction, these dosimeters appear to be an ideal choice for IORT. Conflict of Interest: ASB has a sponsored research agreement with Sicel Technologies, Inc.

Identifying Habitat Variables Important to the Rare Columbia Spotted Frog in Utah (U.S.A.): an Information‐Theoretic Approach

Abstract: We identified habitat associations of the rare Columbia spotted frog ( Rana luteiventris). We used an information‐theoretic approach that encouraged careful consideration of previous studies, demanded a priori formulation of hypotheses and models, and provided interpretable results while avoiding some criticisms of traditional statistical analyses. We formulated hypotheses about habitat associations based on conductivity, emergent vegetation, littoral zone depth, pond hydrology, and water temperature. We modeled hypothesized associations with logistic regression and used Akaike's information criterion to quantify evidence for models, weigh the relative importance of each habitat variable, and select predictive models. Although variable, results suggested that spotted frogs are more likely to occur in ponds that do not shrink in size seasonally, maintain relatively constant seasonal water temperature, and have high emergent vegetation cover. Associations we identified will assist actions in Utah that may be critical to local persistence of spotted frogs. Moreover, this approach for identifying associations has great potential for other rare species.

Distribution, development, and metabolism of larval stages of the warmwater shrimp, Caridina babaulti basrensis (Decapoda, Atyidae)

Peak release of zoea I larvae of the warmwater shrimp, Caridina babaulti basrensis (Al-Adhub AHY 1987) in the field coincided with the highest summer water temperature (33°C). Zoea I abundances did not correlate significantly with the phase of the lunar cycle (p = 0.256) and only slightly with time of day (day : night regimes, p = 0.079). Temperature correlated significantly with zoeae I larval release in the field (p < 0.0001). Development and respiration were measured at constant water temperatures ranging from 20 to 35°C in coordination with the temporal distribution of larvae in the field. Cumulative duration for the development of the larval phase of C. babaulti basrensis was 11.4, 7.7, and 6.1 days at 25, 30, and 35°C, respectively. Larvae were unable to complete development at 20°C. Respiration rate for larval C. babaulti basrensis increased in direct proportion to temperature, and revealed metabolic stress at high temperatures. Laboratory rearing supported field data, which indicated a constraint on the presence of stage I zoeae in the plankton at lower temperatures (20°C). Although some larval stages may be metabolically stressed at higher temperatures, rapid development rates accomplished at higher temperatures may be a likely mechanism for retention within the habitat and recruitment to the adult population.

The effect of uniform heating on the biomechanical properties of the intervertebral disc in a porcine model

Background context The use of minimally invasive lumbar intradiscal heating techniques, including intradiscal electro-thermal therapy (IDET), endoscopic radio-frequency annuloplasty, nucleoplasty and laser discectomy, for chronic lumbar discogenic pain and contained disc herniation has recently gained popularity. The purported therapeutic mechanisms of these interventions include subtotal nuclectomy, annular nociceptor ablation, and stabilization of the annular fibers. Basic science data elucidating the biomechanical and histomorphologic alterations of heat treatments on disc remain sparse. Purpose The purpose of this study is to examine the effects of uniform heating on biomechanical properties and histomorphology of intervertebral disc tissues using a porcine model. Study design/setting In a laboratory setting, porcine functional spinal units consisting of vertebra-nucleus pulposus-vertebra core and porcine hamstring tendons were harvested. Studies were performed on these tissue samples by uniformly heating the specimens in a constant temperature water bath. Ten porcine lumbar disc core and twenty-five porcine hamstring tendons were utilized as the subjects for this study. The effects of uniform heat treatments on disc core and hamstring tendon were measured for shrinkage, stiffness, and load to failure strength. Histomorphological study was also carried on the same specimen. Methods The porcine vertebra-nucleus pulposus-vertebra segments were cored to a uniform 1-cm diameter. The hamstring tendons were cut to uniform 1.2-inch lengths. The tendon specimens were divided into groups of five each and heated in constant temperature water baths of 60°C, 65°C, 70°C, or 75°C for 10 min. Unheated specimens served as controls. The disc core specimens were divided in two group of five each, and tested at room temperature or after immersion in a 70°C bath. The shrinkage was monitored during immersion in the water bath. Biomechanical testing to failure was carried out using mechanical loading on an MTS servohydraulic testing machine operating under stroke control. Strength and stiffness of the tissue was determined. Histomorphology was studied by staining the specimen with hematoxylin and eosin (H&E), and examined under 200 times magnification. Non-heated controls were used for comparisons. Results The porcine hamstring tendons had no measurable shrinkage in specimens heated up to 65°C. At temperatures above 65°C, the shrinkage was concluded within 2 min of immersion and 70°C appeared to be the optimal temperature, as temperatures higher than this did not demonstrate incremental effects. The disc core samples were heated to 70°C (optimum temperature), and there appeared to be gross contraction of the disc core circumference to visual inspection, but no measurable lengthwise shrinkage could be appreciated. Histologically, the specimens demonstrated progressive loss of individual collagen fiber outline as the temperature increased. In the tendons, at 75°C all of the fibers appear to be fused together, and the voids between individual collagen fibers were no longer present. Biomechanical testing revealed that the tendons undergo a substantial reduction in stiffness after heating. The mean tendon stiffness for the unheated specimens was 19,356 psi, while the corresponding value for the heated tendons was 1023 psi. These were significantly different using the paired t-test at p=0.0043. For the disc core samples, there was no significant difference in either stiffness (p=0.182) or failure strength (p=0.998) after heating. All failures occurred in mid-substance of the specimen. Conclusions The application of uniform heating to nucleus pulposus disc core caused visible contraction of its circumference but not lengthwise shrinkage. The same heating shrinks the hamstring tendon and reduces its stiffness. Ultimate failure strength of the disc core specimen remains unchanged. The failure data was not obtainable for the tendon due to premature slippage from the fixation apparatus before failure. The results of this study fail to support a biomechanical justification for the application of uniform heat treatment to the whole intervertebral disc. Heating annulus fibrosus and nucleus pulposus separately to specific temperatures may have potential clinical benefits.

The Turtles of Rainbow Run (Marion County, Florida): Observations on the Genus Pseudemys

We conducted a 13-year study of a stream community of eight turtle species in a west-central Florida spring-run. A major shift towards smaller species is apparent when this study is compared to another made at the same locality six decades earlier. Over the duration of our study, sizes of Pseudemys concinna and P. floridana populations appeared to increase, though not to the levels of six decades previously. Average adult size for both species also increased significantly; these changes may reflect enhanced levels of protection. Growth rates of P. concinna and P. floridana vary throughout life and appear to be strongly seasonal. In light of constant water temperature and abundant food, we suggest that basking behaviors may limit growth, and the availability of basking sites may be critical to the health of the population. Data on sexual dimorphism in P. concinna and P. floridana are also presented.

Humectant release from membrane materials

We report the results of membrane filtration studies designed to measure the removal of humectant preservatives (expressed as total organic carbon) from new membrane samples. Membranes with different characteristic properties, that is, relative molecular mass cutoff and material chemistry, were filtered with deionized water under constant flux and feed water temperature (in either dead-end or cross-flow devices) to determine the area-normalized filtrate volume required to remove all of the measurable organic carbon. For specific cases, the effects of changing flux and feed water temperature are also reported. Release of humectants depends on the nominal relative molecular mass cutoff and the thickness (including support) of the membrane—complete removal is not simply predicted by a soaking time or measured volume of deionized water filtered through the membrane without regard to the flux. This report provides general guidance and a suggested measurement technique for monitoring the removal of membrane preservatives prior to membrane application studies.

The effect of gluten on the retrogradation of wheat starch

The retrogradation of amylopectin in a wheat starch and a wheat starch/gluten (10:1) blend prepared by extrusion and containing 34% water (wet weight basis) was studied using X-ray diffraction, differential scanning calorimetry and NMR relaxometry during storage at constant water content and temperature (25 °C). For both samples, amylopectin ‘fully’ retrograded after ∼2–3 days storage, i.e. the different parameters monitored with time to follow the retrogradation had reached their maximum value, and crystallised predominantly into the A polymorph. Under the experimental conditions used, there was no evidence of any significant effects of the presence of gluten on the kinetics, extent or polymorphism of amylopectin retrogradation.

Docetaxel and hyperthermia: factors that modify thermal enhancement.

Hyperthermia enhances the cytotoxicity of some chemotherapeutic agents and recent studies suggest that docetaxel may show improved response at elevated temperatures. Factors that may modify the thermal enhancement of docetaxel were studied to optimize its clinical use with hyperthermia. The tumor studied was an early-generation isotransplant of a spontaneous C3Hf/Sed mouse fibrosarcoma, Fsa-II. All studies were approved by the Animal Care and Use Committee. Docetaxel was given as a single intraperitoneal injection. Hyperthermia was achieved by immersing the tumor-bearing foot into a constant temperature water bath. Four factors were studied: duration of hyperthermia, sequencing of hyperthermia with docetaxel, intensity of hyperthermia, and tumor size. To study duration of hyperthermia tumors were treated at 41.5 degrees C for 30 or 90 min immediately after intraperitoneal administration of docetaxel. For sequencing of hyperthermia and docetaxel, animals received hyperthermia treatment of tumors for 30 min at 41.5 degrees C immediately after drug administration, hyperthermia both immediately and 3 hr after docetaxel administration and hyperthermia given only at 3 hr after administration of docetaxel. Intensity of hyperthermia was studied using heat treatment of tumors for 30 min at 41.5 or 43.5 degrees C immediately following docetaxel administration. Effect of tumor size was studied by delaying experiments until three times the tumor volume (113 mm(3)) was observed. Treatment of tumors lasted for 30 min at 41.5 degrees C immediately following drug administration. Tumor response was studied using the mean tumor growth time. Hyperthermia in the absence of docetaxel had a small but significant effect on tumor growth time at 43.5 degrees C but not at 41.5 degrees C. Hyperthermia at 41.5 degrees C for 90 min immediately after docetaxel administration significantly increased mean tumor growth time (P = 0.0435) when compared to tumors treated with docetaxel at room temperature. Treatment for 30 min had no effect. Application of hyperthermia immediately and immediately plus 3 hr following docetaxel was effective in delaying tumor growth. Treatment at 3 hr only had no effect. No significant difference in mean tumor growth time was observed with docetaxel and one half hour of hyperthermia at 41.5 or 43.5 degrees C. For larger tumors, hyperthermia alone caused a significant delay in tumor growth time. Docetaxel at 41.5 degrees C for 30 min did not significantly increase mean tumor growth time compared to large tumors treated with docetaxel at room temperature. Docetaxel shows a moderate increase in anti-tumor activity with hyperthermia. At 41.5 degrees C the thermal enhancement of docetaxel is time dependent if hyperthermia is applied immediately following drug administration. With large tumors docetaxel alone or docetaxel plus hyperthemia showed the greatest delays in tumor growth time in the experiments.

Development of the common dentex (Dentex dentex) eggs in relation to temperature

Embryonic development of common dentex (Dentex dentex) was investigated at nine different constant water temperatures (8°C, 10°C, 12°C, 14°C, 16°C, 18°C, 20°C, 22°C and 24°C). The observed effects were compared using of regression analysis. Constant water temperatures between 12°C and 18°C were found to support successful embryonic development. A negative relationship between the rate of embryonic development and incubation temperature was observed. While embryonic development was completed within this range (12°C–18°C), there was no cell division at water temperatures of 8°C and 24°C. Total mortalities were observed at the 128 cleavage stage at a temperature of 10°C, and after the beginning of gastrulation at 20°C and 22°C.

Assessment of Cellular Response to Thermal Laser Injury Through Bioluminescence Imaging of Heat Shock Protein 70¶†

Assessment of laser-induced tissue damage is not complete without an investigation into the resulting cellular and molecular changes. In the past, tissue damage was quantified macroscopically by visual effects such as tissue mass removal, carbonization and melting. Microscopically, assessment of tissue damage has been typically limited to histological analysis of excised tissue samples. In this research, we used heat shock protein (hsp70) transcription to track cellular response to laser-induced injury. A stable cell line (NIH-3T3) was generated containing the firefly luciferase (luc) reporter gene attached to the hsp promoter (murine hsp70a1). After thermal injury with a pulsed holmium-yttrium aluminum garnet laser (lambda = 2.1 microm, taup = 250 micros, 30 pulses, 3 Hz), luciferase is produced on hsp70 activation and emits broad-spectrum bioluminescence over a range of 500-700 nm, with a peak at 563 nm. The onset of bioluminescence can be seen as early as 2 h after treatment and usually peaks at 8-12 h depending on the severity of heat shock. The luminescence was quantified in live cells using bioluminescence imaging. A minimum pulse energy (65 mJ/pulse [total energy 1.95 J; total radiant exposure = 6 J/cm2]) was needed to activate the hsp70 response, and a higher energy (103 mJ/pulse [total energy 3.09 J; total radiant exposure = 9.6 J/cm2]) was associated with a reduction in hsp70 response and cell death. Bioluminescence levels correlated well with actual hsp70 protein concentrations as determined by enzyme-linked immunosorbent assay. Photon counts were normalized to the percentage of live cells by means of a flow cytometry cell viability assay. Within a relatively small range between a lower activation threshold and an upper threshold that leads to cell death, the hsp70 response followed an Arrhenius relationship when constant-temperature water bath and laser experiments were carried out.

Closed loop pulsating heat pipes: Part A: parametric experimental investigations

Closed loop pulsating heat pipes (CLPHPs) are complex heat transfer devices having a strong thermo-hydrodynamic coupling governing the thermal performance. In this paper, a wide range of pulsating heat pipes is experimentally studied thereby providing vital information on the parameter dependency of their thermal performance. The influence characterization has been done for the variation of internal diameter, number of turns, working fluid and inclination angle (from vertical bottom heat mode to horizontal orientation mode) of the device. CLPHPs are made of copper tubes of internal diameters 2.0 and 1.0 mm, heated by constant temperature water bath and cooled by constant temperature water–ethylene glycol mixture (50% each by volume). The number of turns in the evaporator is varied from 5 to 23. The working fluids employed are water, ethanol and R-123. The results indicate a strong influence of gravity and number of turns on the performance. The thermophysical properties of working fluids affect the performance which also strongly depends on the boundary conditions of PHP operation. Part B of this paper, which deals with development of semi-empirical correlations to fit the data reported here coupled with some critical visualization results, will appear separately.