Airtight Chamber Research Articles

A Novel Concept for Safe, Stiffness-Controllable Robot Links.

The recent decade has seen an astounding increase of interest and advancement in a new field of robotics, aimed at creating structures specifically for the safe interaction with humans. Softness, flexibility, and variable stiffness in robotics have been recognized as highly desirable characteristics for many applications. A number of solutions were proposed ranging from entirely soft robots (such as those composed mainly from soft materials such as silicone), via flexible continuum and snake-like robots, to rigid-link robots enhanced by joints that exhibit an elastic behavior either implemented in hardware or achieved purely by means of intelligent control. Although these are very good solutions paving the path to safe human-robot interaction, we propose here a new approach that focuses on creating stiffness controllability for the linkages between the robot joints. This article proposes a replacement for the traditionally rigid robot link-the new link is equipped with an additional capability of stiffness controllability. With this added feature, a robot can accurately carry out manipulation tasks (high stiffness), but can virtually instantaneously reduce its stiffness when a human is nearby or in contact with the robot. The key point of the invention described here is a robot link made of an airtight chamber formed by a soft and flexible, but high-strain resistant combination of a plastic mesh and silicone wall. Inflated with air to a high pressure, the mesh silicone chamber behaves like a rigid link; reducing the air pressure, softens the link and rendering the robot structure safe. This article investigates a number of link prototypes and shows the feasibility of the new concept. Stiffness tests have been performed, showing that a significant level of stiffness can be achieved-up to 40 N reaction force along the axial direction, for a 25-mm-diameter sample at 60 kPa, at an axial deformation of 5 mm. The results confirm that this novel concept to linkages for robot manipulators exhibits the beam-like behavior of traditional rigid links when fully pressurized and significantly reduced stiffness at low pressure. The proposed concept has the potential to easily create safe robots, augmenting traditional robot designs.

Photocatalytic air purifiers for indoor air: European standard and pilot room experiments.

At the European level (CEN/TC386), some efforts are currently devoted to new standards for comparing the efficiency of commercial photocatalytic material/devices in various application fields. Concerning prototype or commercial indoor photocatalytic air purifiers designed for volatile organic compounds (VOC) abatement, the methodology is based on a laboratory airtight chamber. The photocatalytic function is demonstrated by the mineralization of a mixture of five VOCs. Experimental data were obtained for four selected commercial devices and three commercial materials: drop of VOC concentration, but also identification of secondary species (with special attention to formaldehyde), mineralization rates, and Clean Air Delivery Rate (CADR). With two efficient air purifiers, these laboratory experiments were compared to the results in two experimental rooms (35-40m3) where air pollution was introduced through wooden floor and furniture. The systems' ageing was also studied. The safety of the commercial products was also assessed by the determination of nanoparticle release. Standardized tests are useful to rank photocatalytic air purifiers and passive materials and to discard inefficient ones. A good correlation between the standard experiments and the experimental room experiments was found, even if in the latter case, the concentration of lower weight VOCs drops less quickly than that of heavier VOCs.

Application of intermittent negative pressure on the lower extremity and its effect on macro- and microcirculation in the foot of healthy volunteers.

Intermittent negative pressure (INP) applied to the lower leg and foot may increase peripheral circulation. However, it is not clear how different patterns of INP affect macro‐ and microcirculation in the foot. The aim of this study was therefore to determine the effect of different patterns of negative pressure on foot perfusion in healthy volunteers. We hypothesized that short periods with INP would elicit an increase in foot perfusion compared to no negative pressure. In 23 healthy volunteers, we continuously recorded blood flow velocity in a distal foot artery, skin blood flow, heart rate, and blood pressure during application of different patterns of negative pressure (−40 mmHg) to the lower leg. Each participant had their right leg inside an airtight chamber connected to an INP generator. After a baseline period at atmospheric pressure, we applied four different 120 sec sequences with either constant negative pressure or different INP patterns, in a randomized order. The results showed corresponding fluctuations in blood flow velocity and skin blood flow throughout the INP sequences. Blood flow velocity reached a maximum at 4 sec after the onset of negative pressure (average 44% increase above baseline, P < 0.001). Skin blood flow and skin temperature increased during all INP sequences (P < 0.001). During constant negative pressure, average blood flow velocity, skin blood flow, and skin temperature decreased (P < 0.001). In conclusion, we observed increased foot perfusion in healthy volunteers after the application of INP on the lower limb.

Aerobiology of the built environment: Synergy between Legionella and fungi.

The modern built environment (BE) design creates unique ecological niches ideal for the survival and mutual interaction of microbial communities. This investigation focused on the synergistic relations between Legionella and the fungal species commonly found in BEs and the impact of these synergistic relationships on the survival and transmission of Legionella. A field study was conducted to identify the types and concentrations of fungi in BEs. The fungal isolates purified from BEs were cocultured with Legionella to study their synergistic association. Cocultured Legionella cells were aerosolized in an air-tight chamber to evaluate the efficacy of ultraviolet (UV) to inactivate these cells. Aspergillus, Alternaria, and Cladosporium were the most common fungi detected in samples that tested positive for Legionella. After coculturing, Legionella cells were detected inside fungal hyphae. The microscopic observations of Legionella internalization in fungal hyphae were confirmed by molecular analyses. UV disinfection of the aerosolized Legionella cells that were cocultured with fungi indicated that fungal spores and propagules act as a shield against UV radiation. The shield effect of fungal spores on Legionella cells was quantified at >2.5 log10. This study provides the first evidence, to our knowledge, of Legionella cell presence inside fungi detected in an indoor environment. This symbiotic relationship with fungi results in longer survival of Legionella under ambient conditions and provides protection against UV rays.

Flower opening and vase life of gladiolus cultivars: the sensitivity to ethylene and the carbohydrate content

Vase life is one of the most important characteristics in the quality of cut flowers. The carbohydrate content of petals from each cultivar can be a decisive factor to vase life of gladiolus flowers. Despite exposure to ethylene does not affect the life of open florets of gladiolus flowers, it may reduce the flower’s commercial life due the occurrence of flower buds abortion. This study thus aimed to evaluate the flower opening and the vase life of gladiolus flowers according to ethylene sensitivity and carbohydrate content of each cultivar. The gladiolus cultivars used in Experiment I were ‘Amsterdam’, ‘Blue Frost’, ‘Gold Field’, ‘Green Star’, ‘Jester’, ‘Lavender’, ‘Red Beauty’, ‘Rose Supreme’, ‘Traderhorn’, and ‘Verônica’. Stems were stored in airtight chambers and exposed to the ethylene concentrations of 0, 0.1, 1.0, 10, 100, and 1000 μL L−1 for 24 h. Subsequently, flower stem were placed in a test tube with distilled water when were evaluated for percentage of flower opening and vase life. In Experiment II, three cultivars (‘Amsterdam’, ‘Red Beauty’, and ‘Verônica’) were chosen based on the lowest, medium, and highest vase life in Experiment I, respectively. Total soluble sugars, reducing sugars, and starch contents were evaluated in five flower developmental stages. No effect of ethylene on the flower opening or alterations in flower opening between cultivars. The vase life of gladiolus flowers differed between cultivars regardless of ethylene action. ‘Verônica’ and ‘Amsterdam’, which had the highest and lowest vase life, respectively, differed as to the total soluble sugar content. Ethylene does not influence the flower opening or vase life of the gladiolus cultivars studied. In these cultivars, the maintenance of flower opening is attributed to total soluble sugars content, which, in turn, is a major determinant of the vase life.

Method of Measurement of CO2 Adsorbed into α-Cyclodextrin by Infra-Red CO2 Probe

A simple CO2 probe system for quantifying CO2 gas adsorbed in solid matrix of α-cyclodextrin powder (α-CD) by measuring the gas concentration in the headspace was developed and validated. The essential components of this system are an infrared CO2 probe and an air tight chamber equipped with a two-fan system to uniformly mix the relatively high density CO2 gas. First, a known weight of dry ice (considered as pure CO2) was used to create different amounts of CO2 in the headspace of the chamber, and the resultant gas concentrations were measured by the probe and gas chromatography. The gas concentrations measured by both methods were quite similar (R2 = 0.9950), and the calculated amount of dry-ice in the headspace using the probe was highly comparable to the amount of dry ice initially added in the chamber (R2 = 0.9970). This system was then tested to measure adsorbed CO2 content in CO2-α-CD complexed powder by using water injection to release CO2 from the complexed powder into the headspace. The measured results using this system were quite similar (R2 = 0.9972) to those determined by a conventional acid-base titration method.

Impact Of Hypoxia In The Expression And Regulation Of The TASK‐1 Potassium Channel In Cardiac Myocytes

TASK‐1 is a member of the two‐pore domain potassium channel family and strongly expressed in the heart. However, little is known about the roles and regulation of TASK‐1 channels in cardiac hypoxia. The present study was designed to investigate whether hypoxia modulated the expression and function of TASK‐1 and whether protein kinase C (PKC) was critical in hypoxia‐mediated processes in adult rat cardiac myocytes. The effects of acute hypoxia on the TASK‐1 channel function were chemically induced by sodium cyanide (NaCN). Activity of TASK‐1 in cardiomyocytes was investigated by the whole‐cell patch‐clamp technique. The current flowing through TASK‐1 channels in cardiac myocytes was quantified by analyzing the effects of extracellular pH or the selective TASK‐1 inhibitor methanandamide on the steady‐state current‐voltage relation. The voltage protocol, which included voltage ramps from +40 to −100 mV preceded by a test pulse from 0 to +40 mV, was designed to inactivate voltage‐dependent ion channels. In addition, a blocker cocktail, that had no effect on TASK‐1 channels expressed in HEK293T cells, was used to eliminate a number of ion channels in cardiac myocytes. Our data show that exposure of cardiac myocytes to NaCN for 5 minutes reduced the steady‐state outward current at +40 mV, an effect that was abolished by pretreatment with methanandamide. Either methanandamide or extracellular acidification (from pH 7.4 to 6.4) decreased the outward current, identifying TASK‐1 as the channel mediating this effect. Interestingly, the NaCN‐induced reduction in the outward current was largely prevented by pretreatment with the PKC selective inhibitor bisindolylmaleimide. To assess the expression and protective role of TASK‐1 in hypoxia, the prolonged hypoxia (4 hours) was employed by incubating cells in an airtight chamber in which O2 was replaced by N2 with glucose‐free Tyrode's solution. While 4 hours of hypoxia caused a significant reduction in the viability of cardiac myocytes, the inhibition of cardiac TASK‐1 channels by methanandamide further increased hypoxia‐induced cell death. Western blot analysis showed that 4 hours of hypoxia led to a decrease in the protein expression of TASK‐1 in cardiac myocytes. In summary, we provided the evidence that TASK‐1 channels in cardiomyocytes is regulated by hypoxia‐induced PKC signaling in cardiomyocytes. Our data are also supportive for a possible role of TASK‐1 channels in the cardioprotection against hypoxia.

Fumigant effect of sweet basil (&lt;i&gt;Ocimum basilicum&lt;/i&gt; L) leaf essential oil on the longevity and fecundity of adult cowpea bruchid &lt;i&gt;Callosobruchus maculatus&lt;/i&gt; (F) and on germination

Fresh pulverised leaves (600g) of Ocimum basilicum (L) were harvested in July, 2014. Essential oil yield from the hydro-distilled leaves after 3 hours was 0.3(w/w) %. GC/MS analysis revealed the predominance of oxygenated monoterpenes (41.0%) in the oil. Terpinen-4-ol was the major oil constituent accounting for 29.8%. Other significant constituents of the oil were γ-terpinene (9.6%), β – Caryophyllene (7.3%), α-Bergamotene (9.2%) and Sabinene Hydrate (5.0%). The oil was therefore of terpinen-4-ol chemotype. The essential oil (EO) vapour was used to generate an insecticidal atmosphere within airtight fumigation chambers (130ml). Each chamber contained 2 pairs of adult C. maculatus and ten seeds of Ife brown cowpea variety. The EO was tested at 10, 20, 30 and 40µl/130ml air. After 24 hours of exposure, the control had the lowest percentage mortality (0.00) while complete adult mortality was observed in both the 30µl and 40µl doses. The LD50 and LD99 of the EO within 24 hours of exposure were 13.33µl/130ml and 41.38µl/130ml, respectively. However, after 48 hours of exposure, all doses gave 100% mortality and were significantly different (P&lt;0.05) from the control where no mortality was observed. At the end of both exposure periods, significantly (P&lt;0.05) fewer eggs were laid on the oil treated seeds than on the control. There was however no significant difference (P&gt;0.05) in the mean percentage germination of treated and control seeds after 24 and 48 hours. Keywords: Essential oil, fumigation, Ocimum basilicum, Callosobruchus maculatus, hydrodistillation

Study on formaldehyde emissions from porous building material under non-isothermal conditions

Based on an improved model of formaldehyde emissions from building material under non-isothermal conditions, the mechanisms of formaldehyde emissions in dry porous building material are discussed. The formaldehyde emissions in an ordinary particle board are simulated under the different non-isothermal conditions, using floor heating and air circulation heating systems. The concentration of formaldehyde that remained in the board is strongly affected by the thermal boundary condition. Experiments demonstrating the emission of formaldehyde during floor heating and air circulation systems are carried out in a controlled environmental chamber. The experimental results validate the proposed model qualitatively. The present work showed that the equilibrium concentration in an airtight chamber having floor heating system is higher than that in an air circulation heating system.

The effects of cysplatin on human adipose tissue derived mesenchymal stromal cells under different oxygen levels

To evaluate the damaging effects of cisplatin on MMSCs from adipose tissue in a phase of active proliferation and the state of the monolayer, this was exposed at standard (20%) and reduced to 1% and 5% level of oxygen. The effect of cisplatin was detected on monolayer cultures in the active growth phase after 2 passages. Profile surface markers of MMSC was determined by flow cytometry. MMSCs viability after incubation with cisplatin was detected by the number of apoptotic and necrotic cells using ANNEXIN V-FITC--PI Kit (Immunotech, France). Standard culture conditions (~20% O₂) were created in a CO₂ incubator (Sanyo, Japan), 5% O₂--using multigas incubator (Sanyo, Japan), 1% O₂--using an airtight chamber (Stemcell Technologies, USA). Incubation of MMSC monolayer with cisplatin at a concentration of 10 ug/ml for 72 hours leads to death of half of the cells in the culture. Cisplatin increased thefracture of PI⁺-cell, and PI⁺/Ann⁺-cells under all culture conditions. The short-term exposure with cisplatin (24 and 48 hours) did not cause the damaging effect. Effects of cisplatin on the MMSC in the growth phase for 48 hours led to accumulation of Ann⁺-cells and PI⁺/Ann⁺-cells under all culture conditions. However, minimal noci-influence of cisplatin was observed in a culture under hypoxic conditions (1% O₂). These data suggest that MMSC monolayer dies primarily through necrosis, whereas MMSCs in the growth phase in response to cisplatin treatment dies by apoptosis, regardless the oxygen tension.

2F31 ヒト上腕動脈における平滑筋機能の非侵襲計測を目指した心電図同期チョッパ圧負荷法の開発

For early diagnosis of atherosclerosis, functional assessments of endothelial cells (ECs) and smooth muscle cells (SMCs) are important. EC function has been evaluated with flow mediated dilation (FMD) test. Evaluation of SMC function has not been established. To evaluate SMC contractility, we developed a pressure mediated contraction (PMC) method in which myogenic contraction of the human brachial artery is induced by applying 50 mmHg of negative pressure to an airtight chamber attached to the arm for 120 s. One of the problems of this method was found to be displacement of brachial artery following negative pressure application. To overcome this problem, we developed a method to evaluate SMC function by measuring myogenic response of the artery by applying chopped positive (20-30 mmHg) or negative pressure (-50 mmHg) synchronized with electrocardiogram. By measuring arterial diameter during unloading phase, the displacement of artery caused by the pressure loading could be reduced markedly from 2.98±1.17 mm (mean ± SD, n = 8) for conventional PMC to 0.20±0.09 mm (n = 8). We also observed that the rate of arterial relaxation under chopped positive pressure was 5.3 ± 1.2 % (n = 6), while that of arterial contraction under chopped negative pressure was 10.2±3.1 % (n = 6). This may indicate that artery has more room for contraction than for relaxation, which is beneficial against sudden decrease in blood pressure.

The Effect of Improving Indoor Air Quality using some C3 Plants and CAM Plants

This paper will describe the physiological characteristics of general ornamental plants and flesh plants that have contrary effects from the preceding researches, and describe the purification effects of volatile organic compound, formaldehyde. The total removal of carbon dioxide per plant was measured by adding and subtracting amount of photosynthesis and respiration for 24 hours in airtight chamber as follows: from change in concentration of carbon dioxide during the 24 hours after the chamber has been shut, the ornamental plant Spathiphyllum spp., Epipremnum aureum, Hedera helix showed decrease in carbon dioxide concentration under environment with light by photosynthesis and increase under environment without light. In case of flesh plant Sansevieria trifasciata var., Notocactus leninghausii, Myrtillocactus polylopha, opposite from the ornamental plant, carbon dioxide concentration changed due to respiration under light and photosynthesis under environment without light. For Spathiphyllum spp. 94ppm per 1,000 cm2 of leaf, and 70ppm for Epipremnum aureum, 28ppm for Hedera helix, 52ppm for Sansevieria trifasciata var., 66ppm for Notocactus leninghausii, and 114ppm for Myrtillocactus polylopha. After injecting 400ppb of formaldehyde, removal of formaldehyde due to adsorption and absorption caused by photosynthesis was calculated with comparison against standard value. Graph of change in formaldehyde concentration showed that ornamental plants Spathiphyllum spp., Epipremnum aureum, and Hedera helix flesh plants such as Sansevieria trifasciata var., Notocactus leninghausii, Myrtillocactus polylopha showed different physiological activities but removal of formaldehyde due to photosynthesis was high for both sorts. Per 1,000 cm2 of leaf area, Spthiphyllum spp., removed 173ppb of formaldehyde, Epipremnum aureum 158ppb, Hedera helix 128ppb, Sansevieria trifasciata var. 94ppb, Notocactus leninghausii 93ppb, and Myrtillocactus polylopha removed 106ppb of formaldehyde. From the above results, the air purification ability for plants can vary significantly under different conditions of temperature, humidity, radiation intensity and continuous researches on the interactions among such conditions and the complex effects of air purification ability is necessary.

English

This study aimed to evaluate the effect of low temperatures on the physiological and enzymatic changes of rice seeds. The seeds were packed in airtight chambers and maintained at temperatures of 8 and -50°C for periods of 15, 30 , 45, 60, 75 and 90 days. The same procedure was adopted for the control treatment with the seeds kept at a temperature of 25°C. The seeds were evaluated regarding germination test; seedling emergency; emergency speed index; length and dry weight of radicle; and seedling of shoot. The activity of amylase and total protein content were also evaluated. The temperatures of 8 and -50°C significantly influenced the physiological quality and the enzyme amylase activity of rice seeds, resulting in higher germination, seedling emergence and enzyme activity. The temperature is a promising alternative for the maintenance of physiological quality and enzymatic activity of rice seeds during storage. Key words : Oryza sativa L., enzymatic activity, physiological quality, storage. Abbreviation : ESI, Emergence speed index; PVP, polyvinylpyrrolidone.

A Chinese alligator in heliox: formant frequencies in a crocodilian.

ABSTRACTCrocodilians are among the most vocal non-avian reptiles. Adults of both sexes produce loud vocalizations known as ‘bellows’ year round, with the highest rate during the mating season. Although the specific function of these vocalizations remains unclear, they may advertise the caller's body size, because relative size differences strongly affect courtship and territorial behaviour in crocodilians. In mammals and birds, a common mechanism for producing honest acoustic signals of body size is via formant frequencies (vocal tract resonances). To our knowledge, formants have to date never been documented in any non-avian reptile, and formants do not seem to play a role in the vocalizations of anurans. We tested for formants in crocodilian vocalizations by using playbacks to induce a female Chinese alligator (Alligator sinensis) to bellow in an airtight chamber. During vocalizations, the animal inhaled either normal air or a helium/oxygen mixture (heliox) in which the velocity of sound is increased. Although heliox allows normal respiration, it alters the formant distribution of the sound spectrum. An acoustic analysis of the calls showed that the source signal components remained constant under both conditions, but an upward shift of high-energy frequency bands was observed in heliox. We conclude that these frequency bands represent formants. We suggest that crocodilian vocalizations could thus provide an acoustic indication of body size via formants. Because birds and crocodilians share a common ancestor with all dinosaurs, a better understanding of their vocal production systems may also provide insight into the communication of extinct Archosaurians.

Value of hyperbaric oxygen therapy in the management of malignant otitis externa patients

Abstract Malignant external otitis is a rapidly spreading bacterial infection that is aggressive in nature and may be fatal if left untreated. Hyperbaric oxygen therapy (HBOT) is a medical treatment in which the entire body is placed in an airtight chamber at increased atmospheric pressure and has been proven to be effective for a number of different medical conditions. The aim of this study was to assess the usefulness of HBOT as an adjunctive treatment in patients with malignant otitis externa. Forty-three diabetic patients, who had malignant otitis externa, underwent control of diabetes mellitus and were treated with ciprofloxacin. HBOT was administered to 15 patients as an adjunctive treatment. All the patients were evaluated clinically (in terms of ear discharge, granulations, and pain severity) and radiologically by a temporal bone computed tomography scan. The minimum follow-up duration in both groups was 2 months. HBOT was administered in one session every other day for 2 months, resulting in a total of 30 sessions. Patient factors analyzed included age, sex, ear discharge, and pain severity. A total of 43 patients (28 men, 15 women) were divided into two groups: group A (28 patients) only received the antibiotic ciprofloxacin and group B (15 patients) was treated with ciprofloxacin and hyperbaric oxygen. The severity of pain improved considerably and the pain score decreased markedly from score 3 (severe) to score 0 (no pain) after 1 month in 46.7 and 93.3% of the patients by the end of the second month in comparison with patients treated only with the antibiotic: 0% after 1 month and 28.5% after 2 months. On clinical and microscopic examination, both ear discharge and granulations in the external canal had improved considerably. There was no ear discharge in 80% of patients in group B after one month treathent, 93.3% after 2 months, in comparison with 0% after 1 month, 28.5% after 2 months treatment in group A, highly statistically significant (P<0.001). The addition of HBOT to medical treatment is highly effective and has facilitated considerable improvement in patients.

Abstract A68: Hypoxia-induced CHK1 repression may enhance the mutator phenotype of pancreatic cancer cells

Abstract Background: Dysregulation of DNA repair mechanisms are known to play a major role in tumor progression. Moreover, the tumor microenviroment itself has been shown to enhance this phenomenon. For example, studies using reporter genes and endogenous loci have demonstrated increased mutation rates in cells grown in tumors compared to the identical cells grown in culture, or a higher frequency of point mutations in cancer cells cultured under hypoxic conditions, a common feature during tumor growth. An accepted mechanism for these observations is hypoxia-induced down-regulation of MLH1, MSH2 or MSH6 leading to an increased mutation rate, or to hypoxia-induced repression of DNA double strand break repair. Methods: Expression microarrays were performed using RNA isolated from nine pancreatic cancer cell lines cultured under normoxic (Nx, 20% O2) or hypoxic conditions (Hx, 1% O2) for 24 hours to identify differentially expressed genes. Retroviruses encoding oligos for HIF-1 or HIF-2 knockdown were used to generate stable pancreatic cancer cell lines in which HIF-1 or HIF-2, respectively, expression was blocked. Alternatively, Hx was induced by culture of cells inside an air-tight chamber with inflow and outflow valves that was infused with a mixture of 1% O2, 5% CO2 and 94% N2. Protein levels of HIF-1, HIF-2, MLH1, MSH2, MSH6 and CHK1 were determined by western blotting. Cell proliferation was measured by BrdU incorporation and cell cycle analysis by flow cytometry of propidium iodide stained cells. G2/M check point was studied analyzing Histone H3 phosphorylation by flow cytometry and DNA damage was determined by immunofluorescence of cells stained with anti phospho γ-H2AX antibody (γ-H2AX foci formation) Results: We first compared the gene expression profiles of 9 different pancreatic cancer cell lines each grown under normoxic versus hypoxic conditions. As previously described, hypoxia led to down-regulation of the mRNA levels of the mismatch repair proteins MLH1, MSH2 and MSH6 as well as down-regulation of several genes involved in the DNA damage response to double strand breaks such as Brca1, Rad51, Ku70 and Ku80. Of interest, a novel downregulated gene identified was CHK1, a master coordinator of DNA repair following genotoxic stress. Growth of pancreatic cancer cells under hypoxic conditions was confirmed to decrease CHK1 mRNA and protein levels and stable knockdown of HIF-1a but not HIF-2 abolished these effects. In contrast to what have been previously reported in other cancer cell types, hypoxia had no effects on cell proliferation in pancreatic cancer cells as assessed by cell cycle analysis or by BrdU incorporation.To determine if hypoxic down-regulation of CHK1 protein levels has functional effects, we determined the ability of pancreatic cancer cells to arrest in the G2/M checkpoint after ionizing radiation. We found that cells cultured under hypoxia were significantly less arrested on G2/M check point after radiation compared to the same irradiated cells grown under normoxic conditions. This hypoxic effect on G2/M checkpoint was abolished on HIF-1 knockdown cells. Finally, pancreatic cancer cells grown under hypoxic conditions accumulated more DNA damage 24 hours after radiation compared to the same irradiated cells grown under normoxic conditions. Conclusion: Hypoxic conditions decrease CHK1 mRNA and protein levels in pancreatic cancer cells in a HIF1-dependent manner. Impairment on CHK1 function may promote the mutator phenotype of pancreatic cancer cells during tumor progression by allowing unchecked cell divisions despite ongoing DNA damage. This finding also has significance for the use of CHK1 inhibitors for this tumor type. Citation Format: Salvador Naranjo-Suarez, Elsa Callen, Yi Zhong, Alvin Makohon-Moore, Andre Nussenzweig, Christine Iacobuzio-Donahue. Hypoxia-induced CHK1 repression may enhance the mutator phenotype of pancreatic cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A68.

Autonomous Pose Detection and Alignment of Suction Modules of a Biped Wall-Climbing Robot

Vacuum adsorption is a simple but effective attaching method widely used in many fields including robotic wall climbing. It is required that the sucker is aligned well with the target surface to form airtight chamber for vacuum generation. For applications in biped wall-climbing robots, automatically aligning the sucker with the wall is beneficial and important to enhance the efficiency and effectiveness of vacuum adsorption. Especially, such a function is essential for autonomous intelligent climbing. To this end, we propose a novel and low-cost approach to perform autonomous alignment of a sucker (suction module) based on noncontact sensors. We first develop a sensing system to detect the configuration of the swinging suction module with respect to the target surface, and then present an algorithm to compute the configuration transformation and control the robot to drive the suction cups toward the target surface with a well-aligned configuration for adherence. In this paper, the basic theory for autonomous pose detection and alignment of the suction module for wall climbing with a biped robot is presented. Specifically, the key configuration of the swinging suction module for adsorption is analyzed, and the pose detection model, the conditions for forming airtight chamber, and the autonomous alignment algorithm are introduced. Calibration of the sensing system and experiments with our biped wall-climbing robot W-Climbot is conducted. The results have verified the feasibility, effectiveness and applicability of the proposed sensing system, theoretical analysis and the algorithm for autonomous pose detection and alignment of the suction modules.

Role of GRP78 in sevoflurane preconditioning-induced inhibition of apoptosis in cardiomyocytes of rats

Objective To investigate the role of glucose-regulated protein 78 (GRP78) in sevoflurane preconditioning-induced inhibition of apoptosis in cardiomyocytes of rats. Methods The cultured cardiomyocytes of Sprague-Dawley rats were randomly divided into 5 groups(n=30 each) using a random number table: control group (group C), hypoxia-reoxgenation(H/R)group, sevoflurane preconditioning group (group S), siRNA-GRP78 group and siRNA control group.H/R was produced by 2 h exposure of cells to 95% N2-5% CO2 in an air-tight chamber at 37 ℃, followed by reoxygenation with 95% O2-5% CO2 in an air-tight chamber at 37 ℃ for 1 h. In group S, the cells were incubated with 2.5% sevoflurane for 20 min, followed by 10-min washout before H/R.In siRNA-GRP78 group, the cells were transfected with siRNA-GRP78 100 nmol/L, and 24 h later preconditioning with sevoflurane was performed and H/R was produced.In siRNA group, cells were transfected with siRNA, and the other treatments were similar to those previously described in siRNA-GRP78 group.After treatment in each group, the expression of GRP78 in myocardial cells and cytochrome c in cytoplasm and mitochondria was detected by Western blot.Lactic dehydrogenase (LDH) and creatine kinase (CK) activities in the culture medium of each group were determined by ELISA.The apoptosis in myocardial cells was assessed by flow cytometry.Apoptotic rate was calculated.Intracellular free Ca2+ concentration([Ca2+ ]i) was measured with the fluorescent probe Fura-2/AM.The opening of mPTP was measured by fluorescence spectrophotometry. Results Compared to group C, the expression of GRP78 in myocardial cells and cytochrome c in cytoplasm was significantly up-regulated, LDH and CK activities in the culture medium, apoptotic rate and [Ca2+ ]i were increased, and the expression of cytochrome c in mitochondria was down-regulated in H/R group.Compared to group H/R, the expression of GRP78 in myocardial cells and cytochrome c in mitochondria was significantly up-regulated, LDH and CK activities in the culture medium, apoptotic rate, [Ca2+ ]i and opening of mPTP were decreased, and the expression of cytochrome c in cytoplasm was down-regulated in group S, and no significant change was found in the parameters mentioned above in siRNA group.Compared to group S, the expression of GRP78 in myocardial cells and cytochrome c in mitochondria was significantly down-regulated, LDH and CK activities in the culture medium, apoptotic rate, [Ca2+ ]i and opening of mPTP were increased, and the expression of cytochrome c in cytoplasm was up-regulated in group siRNA-GRP78. Conclusion GRP78 is involved in sevoflurane preconditioning-induced inhibition of apoptosis in cardiomyocytes of rats, and the mechanism is related to maintenance of intracellular Ca2+ stability and inhibition of opening of mPTP. Key words: Heat-shock proteins; Anesthetics, inhalation; Ischemic preconditioning; Myocardial reperfusion injury

Indirectly water-cooled production target at J-PARC hadron facility

After the radioactive material leak accident at the J-PARC hadron experimental facility on May 23, 2013, we designed a new production target, which is capable of a primary proton beam with the energy of 30 GeV and power of 50 kW. It is made of gold and cooled by water through a copper block. For the countermeasures of the recurrence of the accident, the target is enclosed by an airtight chamber and helium gas is circulated to monitor the target soundness. In this paper, technical details of the new target design are presented.

Experimental Study on the Formaldehyde Emission under Non-isothermal Conditions

The adverse effects of formaldehyde on the indoor air quality is of serious concern. An experimental apparatus is fabricated to investigate the features of formaldehyde migration from dry porous building materials under non-isothermal conditions. The coupled heat and formaldehyde migration process in an ordinary particle board is investigated in both floor heating system and air circulation system. The instantaneous concentration of formaldehyde in the chamber, the instantaneous temperature of the air, and the instantaneous temperature of the top surface of the board is studied. The temperature of the bottom surface of the board is maintained at 15°C throughout the process. As shown in the experimental process, the equilibrium concentration of formaldehyde increases with an increase in the temperature of air. The equilibrium concentration in an airtight chamber having floor heating system is higher than that in an air circulation heating system. The experimental results validated proposed model. Therefore, it is necessary to improve the ventilation of the rooms using such systems.