Assessment of physical stress during the perioperative period of endoscopic submucosal dissection

The advantage of endoscopic submucosal dissection(ESD)is that it is less invasive than surgery.ESD is one of the best treatments for older patients as surgery in this age group of patients is difficult.However,it is unclear how much lower the physical stress of ESD is compared with that of surgery.Thus,objective methods are required to assess physical stress in patients who have undergone ESD.The current review of ESD aimed to summarize the recent advancements in the assessment of physical stress during the perioperative period,focusing on changes in energy metabolism and serum opsonic activity(SOA).Based on metabolic changes,resting energy expenditure(REE)was measured using an indirect calorimeter.The stress factor calculated from the REE and the basal energy expenditure computed using the Harris-Benedict equation can be used to assess physical stress.SOA was assessed using the chemiluminescence method,wherein the use of chemiluminescent probes(i.e.,lucigenin and luminol)allowed quantification of reactive oxygen species generated by neutrophils.Using an auto luminescence analyzer,the results were evaluated based on the maximum light emission and area under the emission curve.These quantifiable results revealed the minimal invasiveness of ESD.

Effects of Tremella Polysaccharide on Immune Function of Physically-Stressed Mice

An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress were studied in mice.It was found that the spleen plaque forming cell(PFC)response to sheep red blood cells,delayed cuta- neous hypersensitivity(DCH)induced by dinitrochlorobenzene and the lymphocyte prolifer- ation stimulated by concanavalin A(Con A)were significantly decreased in stressed mice. In addition.the maximal decrease of PFC was reached in 9-12 days after stress.A- drenolectomy could not affect the decrease of PFC in stressed mice.TP(200.400mg/kg) ig for 8-14 days significantly restored the PFC.DCH and lymphocyte proliferation to nor- mal level in stressed mice.

Thermoelastic stresses in SiC single crystals grown by the physical yapor transport method

A finite element-based thermoelastic anisotropic stress model for hexagonal silicon carbide polytype is developed for the calculation of thermal stresses in SiC crystals grown by the physical vapor transport method. The composite structure of the growing SiC crystal and graphite lid is considered in the model. The thermal expansion match between the crucible lid and SiC crystal is studied for the first time. The influence of thermal stress on the dislocation density and crystal quality is discussed.

Effect of water restrictions on the physiological parameters,psychological behavior and brain c-Fos expression in rat

Objective In order to characterize the feature of stress response induced by stressor with both physical and psychological natures, the effect of water restriction performed in different experimental modes on the physiological parameters, psychological behavioral manifestations and brain c-Fos expressions were observed and compared. Methods 58 male Wistar rats were used and randomly divided into three experimental groups （n=18 for each） and a control group （n=4）. In control group, the rats were allowed to access drinking water freely at all experimental period. In the experimental groups the water supply to the rats was restricted. In timed water supply （TW） group, the water was supplied twice a day, 10 min for each in fixed hours every day. In empty bottle-served （EB） and water-restricted （WR） groups, the water was served only once a day for 10 min, either in the early morning or evening, and in the other time point scheduled for water supply only an empty bottle without water was provided in the EB group and nothing was given in the WR group. The quantities of drank water and eaten food, weight-gaining, and behavior score were observed every day. The serum level of corticosterone was assayed and the rats were sacrificed with fixative perfusion of 3 d, 7 d or 14 d respectively, following water restriction （n=6 for each time point in each group）. The brain c-Fos expressions were examined with immunohistochemistry. Results The slowing down of weight-gaining, rise of serum corticosterone level, occurrence of psychological behavioral manifestations of unpeaceful restlessness such as exploring and attacking, enhance of c-Fos expression in the subfomical organ （SFO）, median preoptic nucleus （MnPO）, area postrema （AP）, hypothalamic paraventricular nucleus （PVN）, supraoptic nucleus （SON）, medial （MeA） and central （CeA） amygdaloid nucleus and ventrolateral septum （LSV） were noticed in both EB and WR groups, except the nucleus of solitary tract （NTS） in which the Fos expression was decreased. The changes of Fos expression in most of nuclei in EB group began at day 3, at least persisted till day 7, and backed down at day 14. While in WR group, similar changes started at day 7 and reached its peak at day 14. In TW group, only the concentration of corticosterone at day 7 was slightly increased and the rest indexes observed were unchanged. Conclusion The results indicate that water restriction induces physical as well as psychological stress responses. And the water restrictions experimentally executed in different modes result in different manifestations of behavioral response and brain immediately early gene expression in discrete brain nuclei/regions.

Influence of Filtration Processes on Aqueous Nanostructures by NIR Spectroscopy

Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration processes on water structure detected by spectral variations in NIR region. Samples of ultrapure water （MilliQ-Millipore, Vimodrone, Milan, Italy） before and after iterated filtrations were analyzed. NIR spectra were collected in transmission mode in the whole NIR range, by using NIRFIex N500 spectrometer at constant temperature （40 ± 1 ℃）. NIR data were processed using Unscrambler software v. 9.2 in evaluating qualitative differences between filtered and not filtered samples. The information related to possible solvent physical stresses were highlighted in the range 6500-7500 cm^-1. The shifts observed were ascribable to a different distribution of the number of water molecules involved in hydrogen bonds in filtered and not filtered water samples, at constant temperature. NIR spectroscopy, commonly used to study relationship between spectral changes and hydrogen bonds in water at increasing temperature values, was applied to evaluate effects of filtration processes on water structure. The obtained results are in agreement with literature data and allowed the improvement of the knowledge about pure water characteristics when some mechanical perturbations are applied.

Correlation of Cooperatively Localized Rearrangement on the ＂Fluidized Domain＂ of Polymers to Their Nonexponentially Viscoelastic Behavior and Lifetime at Double Aging Processes II： Estimation of Long-term Mechanical Behavior and Lifetime of Polymeric Materials from Short-time Creep and Stress Relaxation Tests

Three kinds of polymeric materials are taken as example for the verification of linear ex-trapolation method from unified master lines with reduced universal equations on creep and stress relaxation tests. The theoretical values of long-term mechanical behavior and lifetime for a cured epoxide, polypropylene, poly（methyl-methacrylate）, and SBR rubber are directly evaluated with the universal equations on reduced creep compliance and reduced stress relax-ation modulus and are compared with their predicted values by the linear extrapolation from the unified master lines of creep and stress relaxation. The results show that the theoretical values of dimensional stability, bearing ability and lifetime are in an excellent agreement with the predicted values, it shows that the linear extrapolation method is more simple and reliable. The dependences of long-term mechanical behaviors and lifetime on the different aging times are discussed.