HPO Group Research Articles

Impact of try-in paste removal on the fatigue behavior of bonded lithium disilicate ceramics

This in vitro study assessed the effectiveness of three cleaning protocols (air-water spray, 37% phosphoric acid, or Ivoclean) on lithium disilicate restorations' fatigue behavior after try-in paste application, compared to a clean condition. Lithium disilicate discs (IPS e.max CAD, Ivoclar) with Ø-= 12 mm and 1 mm thickness were prepared from prefabricated CAD-CAM blocks, polished, subjected to CAD-CAM milling topography simulation and crystallization. After, etching with 5% hydrofluoric acid and the application of try-in paste (Variolink try-in paste shade white; load of 2.5 N for 5 min) was performed. Discs that received try-in paste were divided into three groups according to the removal protocol: SPRAY – air-water spray for 30 s; HPO – active application of 37% phosphoric acid for 60 s; IVOC – application of Ivoclean for 20 s. Control group (CTRL group) did not receive the try-in paste application. Half of the specimens (n= 15) were tested in the baseline condition (24 h up to 7 days), and the others underwent 25,000 thermal cycles (5 – 55 °C) + 210 days of distilled water storage (37 °C). Additional specimens (n= 3) underwent monotonic testing (1 mm/min). Fatigue testing involved a cyclic fatigue approach (20 Hz, initial load = 100 N – 5000 cycles, step size = 50 N – 10,000 cycles) until a visible crack appeared. Fractographic and topographic analyses were performed. Fatigue data were statistically analyzed with two-way ANOVA, Kaplan-Meier log-rank (Mantel-Cox), and independent t-test (α= 0.05). In the baseline condition, the IVOC group resulted in a superior fatigue behavior compared to the CTRL and SPRAY groups, but similar to the HPO group. The HPO and SPRAY presented a similar fatigue behavior to the CTRL group. It was noticed a decrease in fatigue behavior after aging, which resulted in all the cleaning protocols leading to similar fatigue behavior compared to the CTRL group. On the SPRAY group surface, try-in pastes remnants were noticed. In summary, despite a detrimental impact at baseline conditions, all tested cleaning protocols seem proper to remove the try-in paste from the ceramic's surface in the long-term evaluation.

Does the Prevalence of Obesity in the Different Regions of Spain Influence the Attitudes, Perception, and Barriers to Its Treatment?

Introduction: The differences in the prevalence of obesity between the various regions of Spain, partly attributed to socioeconomic differences, may influence the approach to this disease. The aim of this study was to compare differences in attitudes, perception, and barriers to the treatment of obesity between people with obesity (PwO) and health care professionals (HCPs), between the different regions of Spain. Methods: Sub-analysis of the ACTION-IO Spain study, which included 1,500 PwO and 306 HCP, was performed to identify differences in PwQ and HCPs belonging to regions with high prevalence of obesity (>16%, n = 9 regions, high prevalence of obesity [HPO] group) and low prevalence of obesity (<16%, n = 8 regions, low prevalence of obesity [LPO] group) (self-reported data), according to the 2017 National Health Survey of Spain. Statistics: comparison of proportions (χ2). Results: A total of 746 PwO belonged to HPO and 754 to LPO group. The PwO in HPO group were younger, had lower income, a lower level of higher education, higher unemployment rate, and fewer comorbidities. Obesity was considered a chronic disease to a higher extent in HPO compared to LPO group (62 vs. 56%), but this difference was not statistically significant. The PwO in HPO group discussed less with the HCPs about their excess weight (57 vs. 70%), did not feel motivated to lose weight in a higher percentage (26 vs. 18%), and felt less emotionally supported (16 vs. 24%). In HPO group, the preference for unhealthy food (51 vs. 36%), and the costs of healthy eating, anti-obesity drugs and bariatric surgery were perceived barriers to losing weight. A higher proportion of PwO in HPO group considered that exercise (58 vs. 40%) was more effective for achieving weight loss. In contrast, LPO group considered diet more effective (48 vs. 32%). HCPs in HPO group felt more motivated to treat obesity (83 vs. 68%) and a higher proportion (14 vs. 5%) identified the economic burden as one of the main reasons why PwO do not start conversations to lose weight. Conclusions: There is less concern and conversation about excess weight in PwO in regions with a higher prevalence of obesity, with socioeconomic limitations being one of the main perceived barriers to treatment.

Effective treatment of high-voltage pulsed radiofrequency combined with oxygen–ozone injection in acute zoster neuralgia

IntroductionPostherpetic neuralgia (PHN) is the most common and severe complication of acute herpes zoster. Early treatment of herpes zoster neuralgia is of great significance to reduce the incidence of PHN. This retrospective study evaluated the efficacy and safety of the combination of high-voltage pulsed radiofrequency (PRF) and oxygen–ozone(O2–O3) injection in patients with acute zoster neuralgia (AZN) who failed to respond to conservative treatment. MethodsOne-hundred patients diagnosed with AZN were classified into two groups (high-voltage PRF group [HP group, n = 50] and high-voltage PRF combined with O2–O3 injection group [HPO group, n = 50]) based on different treatment methods. Therapeutic effectiveness was assessed using a numerical rating scale (NRS) and the Pittsburgh Sleep Quality Index (PSQI). The dosages of gabapentin and tramadol (mg/d) before treatment and after 1 week and 1, 3, and 6 months of treatment were measured. The incidence of clinically meaningful PHN after treatment was also recorded. ResultsPain intensity and sleep quality in both groups at all time points improved after treatment compared to before treatment (P < 0.05). After 1 week and 1 month of treatment, NRS and PSQI scores in both groups decreased, but the differences were not statistically significant (P > 0.05). NRS, PSQI scores, and the dosages of gabapentin and tramadol decreased more significantly in the HPO group than those in the HP group after 3 months (P < 0.05). The incidence of PHN was significantly lower in the HPO group than in the HP group (P < 0.05). There were no significant differences in adverse events between the groups. ConclusionsHigh-voltage PRF is a safe and effective method for treating AZN. The combination of high-voltage PRF and O2–O3 injection is superior to high-voltage PRF alone for treating late-stage AZN. This approach could be recommended as an alternative treatment for patients with refractory AZN and could significantly reduce the risk of PHN.

Parabiosis Improves Endothelial Dysfunction in Aged Female Mice

IntroductionThe study aims to investigate the effect of parabiosis method on endothelial dysfunction in naturally aging mice and determine the time projections for predicted improvement in the mentioned target group. MethodsThe balb/c mice were separated into six groups, these being; isochronic old, heterochronic old (HP-O), isochronic young, heterochronic young, young control, and old control. After parabiosis protocol, animals were sacrificed at the third, fifth, seventh, and ninth weeks, and their thoracic aortas were isolated. The vasodilatation and vasoconstriction responses of the vessels were detected using potassium chloride and phenylephrine, acetylcholine (ACh), and sodium nitroprusside. ResultsAging had a significant decreasing effect on maximum ACh relaxation responses (P < 0.01). However, in the HP-O group, the maximum ACh relaxation response in the third week was significantly lower (P < 0.05), but this effect disappeared in the ninth week. Maximum phenylephrine contraction responses were lower in the heterochronic parabiosis group (P < 0.05). ConclusionsACh responses increased at the end of the ninth week in the HP-O group, therefore, the parabiosis model may have an improving effect on endothelial dysfunction seen in aging.

Enhanced Fe3+ binding through cooperativity of 3-hydroxypyridin-4-one groups within a linear co-polymer: wrapping effect leading to superior antimicrobial activity.

To tackle the rise of antibiotic resistant pathogenic microbes, iron withdrawal agents have shown considerable promise as antibiotic alternatives due to the microbes' irreplaceable metabolic need for the essential element iron. DIBI is a water-soluble, linear co-polymer functionalized with 3-hydroxy-pyridin-4-one (HPO) chelators that selectively and strongly bind iron(III) in biological environments. Compared to HPO congeners, DIBI has over 1000 times higher antimicrobial activity against a broad-spectrum of Gram-(+) and Gram-(-) bacteria including highly antibiotic resistant clinical isolates. Herein, we explain the enhanced antimicrobial activity of DIBI by a cooperativity effect of the linear co-polymer wrapping around three iron(III) centres. DIBI's structural and iron(III) binding properties were investigated by comparative experiments against HPO monomer and deferiprone using chemical and physical characterization methods with direct biological implications such as pH stability, reductive off-loading of bound iron(III), trans-membrane permeability, and competition experiments with vertebrate transferrin class iron carrier. The three iron(III) ions bound to DIBI are preferentially incorporated into a tris-bidentate chelates, which forces the linear backbone of the polymer to wrap around the complexes, as the bound iron was much less susceptible to dithionite reduction than the tris iron(III) complexes of HPO monomers and deferiprone. The results suggest a high degree of cooperativity of the polymer-bound HPO groups to effect a wrapping of the polymer backbone around the chelated iron, shielding the iron(III) centres from ready access by microbes. The structural effect of DIBI is compared to polymers containing 3-hydroxy-pyridin-4-one chelators that do not undergo this wrapping effect.

Hybrid palm oil (Elaeis oleifera × Elaeis guineensis) supplementation improves plasma antioxidant capacity in humans

Hybrid palm oil obtained from interspecific hybrid Elaeis oleifera × Elaeis guineensis palm (HPO) has been recently proved to have a favorable impact on human plasma lipids related to cardiovascular disease risk factors. In the present work, we describe for the first time, the functional effect of crude HPO supplementation on human antioxidant plasma/serum status as assessed by the total phenolic content (Folin–Ciocalteu), ORAC and TEAC assays. One hundred sixty eligible participants (&gt;50 years) were randomized and assigned to one of the two treatments: 25 mL hybrid palm oil (HPO group) or 25 mL extra virgin olive oil (EVOO group) daily for 3 months. This study showed that supplementation of 25 mL of HPO for a period of 3 months significantly increased (p &lt; 0.01) the total phenolic content (19.2%) as well as the antioxidant capacity of human plasma measured by both ORAC (92.1%) and TEAC (42.9%) methods. Furthermore, no significant differences were found between HPO and EVOO groups in a repeated measures analysis of variance for TPC (p = 0.344), TEAC (p = 0.217), and ORAC (p = 0.318) values. These results confirm that HPO can be considered a promising tropical edible oil with potential beneficial health effects.Practical applications: The understanding of the antioxidant properties of an edible oil in vivo is of primary importance when evaluating its nutritional/functional characteristics and/or its potentiality to serve as an active ingredient for functional food preparations. The results of this study confirm that HPO can be considered a promising tropical edible oil with beneficial health properties since it is able to improve the antioxidant status of plasma in humans.This 3‐month randomized trial reported examines and compares the effects of 25 mL/day supplementation of crude hybrid palm oil (Elaeis oleifera × Elaeis guineensis), thought to be a possible tropical equivalent of the Mediterranean extra‐virgin olive oil, to the ones of extra‐virgin olive oil, which is considered as a gold standard in the functional dietary oils skyline. Interestingly, at the end of the third month of study, the effects obtained by the supplementation with hybrid palm oil are similar to those provided by the extra‐virgin olive oil supplementation. In fact, hybrid palm oil consumption has been shown to significantly increase the total phenolic content (19.2%, p &lt; 0.01) as well as the antioxidant capacity of human plasma measured by both TEAC (42.9%, p &lt; 0.01) and ORAC (92.1% p &lt; 0.01) assays.

Total Worker Health Intervention Increases Activity of Sedentary Workers.

Office employees are exposed to hazardous levels of sedentary work. Interventions that integrate health promotion and health protection elements are needed to advance the health of sedentary workers. This study tested an integrated intervention on occupational sedentary/physical activity behaviors, cardiometabolic disease biomarkers, musculoskeletal discomfort, and work productivity. Two-group, RCT. Data were collected between January and August 2014. Overweight/obese adults working in sedentary desk jobs were randomized to: (1) a health protection-only group (HPO, n=27); or (2) an integrated health protection/health promotion group (HP/HP, n=27). HPO participants received an ergonomic workstation optimization intervention and three e-mails/week promoting rest breaks and posture variation. HP/HP participants received the HPO intervention plus access to a seated activity permissive workstation. Occupational sedentary and physical activity behaviors (primary outcomes), cardiometabolic health outcomes, musculoskeletal discomfort, and work productivity (secondary outcomes) were measured at baseline and post-intervention (16 weeks). The HP/HP group increased occupational light intensity physical activity over the HPO group and used the activity permissive workstations 50 minutes/work day. Significant associations were observed between activity permissive workstation adherence and improvements in several cardiometabolic biomarkers (weight, total fat mass, resting heart rate, body fat percentage) and work productivity outcomes (concentration at work, days missed because of health problems). The HP/HP group increased occupational physical activity and greater activity permissive workstation adherence was associated with improved health and work productivity outcomes. These findings are important for employers interested in advancing the well-being of sedentary office workers. This study is registered at www.clinicaltrials.gov NCT02071420.

Amino acid templating of inorganic networks: synthesis and structure of L-asparagine zinc phosphite, C4N2O3H8.ZnHPO3.

C(4)N(2)O(3)H(8).ZnHPO(3) is the first zincophosphite framework to be templated by an amino acid (l-asparagine), which bonds to Zn via a carboxyl O atom. It contains infinite, homochiral, helical 4-ring chains of ZnO(4) and HPO(3) groups, stabilized by intra- and interchain N-H.O hydrogen bonds. Crystal data: C(4)N(2)O(3)H(8).ZnHPO(3), M(r) = 277.49, orthorhombic, P2(1)2(1)2(1) (No. 19), a = 5.0349(2) A, b = 9.4539(4) A, c = 18.6092(8) A, V = 885.79 (6) A(3), Z = 4.

Macrocyclic ligands bearing two 3-(Hydroxy)-2-pyridinone moieties as side-arms. Conformational studies, synthesis, crystal structure, and alkali and alkaline earth complex formation

The synthesis and characterization of the new tetraazamacrocycle 4(N),10(N)-bis[2-(3-hydroxy-2-oxo-2H-pyridin-1-yl)ethyl]-1,7-dimethyl-1,4,7,10-tetraazacyclododecane (L1) is reported. L1 shows two 3-(hydroxy)-1-(carbonylmethylen)-2(1H)-pyridinone (HPO) moieties linked to the macrocyclic base 4,7-dimethyl-1,4,7,10-tetrazacyclododecane, as side-arms. The acid–base and coordination properties towards alkali, alkaline earth ions of L1 together with those of the structurally similar ligand 4-(N),10-(N)-bis[2-(3-hydroxy-2-oxo-2H-pyridin-1-yl)acetamido]-1,7-dimethyl-1,4,7,10-tetraazacyclododecane (L2) are reported. L2 binds all the metal ions investigated forming stable mono-nuclear complexes, while L1 binds only some alkaline earth ions with stability constants lower than those of L2. Both compounds show selectivity towards the Mg(II) ion with respect to the alkaline earth series. The binding area is formed by the four converging oxygen atoms of the two HPO groups. L2 appears to be a more efficient ligand in the coordination of hard metal ions because the two HPO binding groups are forced by the macrocyclic skeleton to stay on the same part of the macrocyclic ring, while this conformation is unfavourable for L1. These data are supported by molecular dynamics (MD) simulations performed on both ligands and by the crystal structure of the [H2L1](ClO4)2 species which shows the two side-arms displaced opposite to the macrocyclic ring. The effects of pH and metal ion coordination on the UV-Vis absorption and fluorescence emission properties of both ligands were investigated, highlighting that the optical properties changes in acid–base reactions as well as in the coordination of metal ions.

Dry mechanochemical synthesis of hydroxyapatites from dicalcium phosphate dihydrate and calcium oxide: a kinetic study.

Calcium phosphate ceramics have been used successfully as synthetic bone substitutes in orthopedics, dentistry, and maxillofacial surgery. One way of preparing these ceramics is the sintering of a calcium-deficient hydroxyapatite (CDHA), which can be obtained in different ways. Mechanochemistry is one possible means of synthesizing CDHA, with an expected molar calcium-to-phosphate (Ca/P) ratio +/- 0.005. The grinding can be carried out under dry or wet conditions. To optimize the experimental conditions of CDHA preparation by dry mechanosynthesis and for a better understanding of the DCPD/CaO mechanochemical reaction, we performed a kinetic study in which some of the experimental parameters were varied. Carried out with two different vertical rotating ball mills, this kinetic study showed that (1) experiments are reproducible and give as a final product a hydroxyapatite powder, formed of nano-sized crystals of around 20 nm, with a controlled Ca/P ratio; (2) the time for complete disappearance of DCPD and the time for complete reaction are in direct proportion to the mass of the ground powder; but (3) the time for complete disappearance of DCPD is independent of the Ca/P ratio while the time for complete reaction increases exponentially with the Ca/P ratio; and (4) the time for complete disappearance of DCPD corresponds to the time for complete reaction solely for Ca/P = 1.5. These observations suggest a reaction mechanism in two well differentiated stages: (First stage) CaO reacts with DCPD to give first an amorphous calcium phosphate (ACP) with a low Ca/P ratio that transforms into CDHA when its Ca/P ratio reaches 1.5. At the same time, CaO is hydrated into Ca(OH)(2) by the water produced by the reaction. (Second stage) If the Ca/P > 1.5 in the initial mixture, the excess Ca(OH)(2) is added to CDHA 1.5 by reacting with the HPO(4) group of CDHA until its Ca/P ratio reaches the expected value. The slower the reaction, the higher the Ca/P in the initial mixture.

Calcium phosphate interactions with titanium oxide and alumina substrates: an XPS study.

Besides the excellent mechanical properties of titanium and alumina (Al(2)O(3)) in the case of load bearing applications, their bone-bonding properties are very different. In osseous environment, Al(2)O(3) ceramic is encapsulated by fibrous tissues, whereas bone can bind directly to titanium, via its natural titanium dioxide (TiO(2)) passivation layer. So far, this calcification dissimilarity between TiO(2) and Al(2)O(3) was attributed to respectively their negative and positive surface charge under physiological conditions. The present study aims at studying the chemical interactions between TiO(2) and Al(2)O(3) (phase alpha) with the diverse ions contained in simulated body fluids (SBFs) buffered with trishydroxymethyl aminomethane (TRIS) at pH=6.0 and pH=7.4. After 1 h of immersion, TiO(2) and alpha-Al(2)O(3) powders were analyzed by X-ray photoelectron spectroscopy (XPS). The results indicated that Ca and HPO(4) groups were present on TiO(2) surface. In addition, HPO(4) groups were found to be in a higher amount than Ca on TiO(2), which does not comply with the surface charge theory. With regard to Al(2)O(3), little HPO(4) but no Ca was detected on its surface, and TRIS bound to Al(2)O(3) substrate in all of the immersion experiments. The fact that both Ca and HPO(4) were present at the vicinity of TiO(2) might be at the origin of its calcification ability. On the other hand, Al(2)O(3) did not show any affinity towards Ca and HPO(4) ions. This might explain the inability of Al(2)O(3) substrate to calcify.

Persistent Transforming Growth Factor-Beta 1 Expression May Predict Peritoneal Fibrosis in CAPD Patients with Frequent Peritonitis Occurrence

The efficiency of continuous ambulatory peritoneal dialysis depends on the permeability of the peritoneal membrane. Peritoneal fibrosis (PF) causes loss of the dialytic function. Several studies have indicated that PF is closely related to the proliferation of peritoneal fibroblasts and the deposition of extracellular matrix. Transforming growth factor-beta 1 (TGF-β1) plays a major role in stimulating extracellular matrix deposition. Frequent peritonitis occurrence may cause persistent TGF-β1 mRNA expression. In an attempt to search for a factor related to PF, we designed a longitudinal study to measure TGF-β1 levels in dialysate and TGF-β1 mRNA expression in peritoneal mononuclear cells from peritoneal dialysate before onset, once a week during peritonitis, and after peritonitis in high and low peritonitis occurrence (HPO and LPO) patients. Fifteen patients with a LPO rate and 5 patients with a HPO rate were followed up longitudinally. Meanwhile, TGF-β1 levels and TGF-β1 mRNA expression were augmented in peritoneal dialysate effluents before, during, and after the episodes of peritonitis. The peritoneal permeability was evaluated by the peritoneal equilibration test. The results revealed that in the LPO group, TGF-β1 and TGF-β1 mRNA were detectable at early stages of peritonitis, but the levels decreased rapidly and were undetectable 2 weeks after peritonitis. On the other hand, in the HPO group, TGF-β1 and TGF-β1 mRNA persisted for a long time. We could detect TGF-β1 and TGF-β1 mRNA in dialysate effluents and peritoneal mononuclear cells even 2, 3, and 4 weeks after episodes of peritonitis. When compared with that of first or second episode of peritonitis, the peritoneal function evaluated with the peritoneal equilibration test was found to obviously deteriorate during the third episode of peritonitis. These findings were confirmed by an in situ hybridization technique to evaluate the relationship between TGF-β1 mRNA expression and PF from biopsied peritoneal specimens. These findings suggest that the high TGF-β1 levels in the dialysate are related to an increased expression of TGF-β1 in the peritoneum. Thus, the persistent TGF-β1 expression in the peritoneum may serve as a useful parameter in predicting PF in continuous ambulatory peritoneal dialysis patients with frequent peritonitis occurrence.

Synthesis and Structure of [(1R,2R)-C(6)H(10)(NH(3))(2)][Ga(OH)(HPO(4))(2)].H(2)O, the First Metal Phosphate Containing a Chiral Amine.

The first metal phosphate containing a chiral amine, [(1R,2R)-C(6)H(10)(NH(3))(2)][Ga(OH)(HPO(4))(2)].H(2)O, has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2(1) with a = 8.7202(2) Å, b = 7.1276(2) Å, c = 11.1411(4) Å, beta = 96.129(1) degrees, and Z = 2. The structure consists of infinite chains of trans-corner-sharing GaO(5)(OH) octahedra with the adjacent octahedra being bridged by HPO(4) groups, which are H-bonded with amine groups of the organic cations and the lattice water. The Ga-O bond lengths along the backbone of the chain are alternately short and long. For comparison, the gallophosphate-containing racemic mix is also synthesized. [trans-1,2-C(6)H(10)(NH(3))(2)][Ga(OH)(HPO(4))(2)].H(2)O crystallizes in the centrosymmetric, orthorhombic space group Pbcm with a = 8.6993(2) Å, b = 21.8612(1) Å, c = 7.1557(2) Å, V = 1360.85(5) Å(3), and Z = 4.

Alterations of systolic time intervals in the assessment of myocardial function during hypertensive pregnancy.

The alterations in the systolic time intervals caused by hypertension during pregnancy have been investigated. A group of 20 women who developed hypertension only during pregnancy (HP), and a group of 16 women who began pregnancy with established hypertension (EHP) were matched with 25 normal pregnant women (N). the study was performed (1) during the third trimester, (2) five days after delivery and (3) five weeks after delivery, both in supine and in lateral postures. In the third trimester the two hypertensive groups, when compared with the normal group, were characterized by a shorter left ventricular ejection time (LVETi: 407 +/- 3 ms for the normal group v. 390 +/- 2 ms for the HPO group, P less than 0.001; v. 398 +/- 2 ms for the EHP group, P less than 0.02), and a longer pre-ejection period (PEPi: 138 +/- 2 ms for the normal group v. 154 +/- 2 ms for the HP group P less than 0.001; v. 145 +/- 1 ms for the EHP group, P less than 0.05). When the two hypertensive groups were compared with each other the HP group showed a shortened LVET and a prolonged PEP (P less than 0.01), and also a slower heart rate (HP 74 +/- 3 b min-1. EHP 83 +/- 3 b min-1 P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Raman and infrared spectra of spermidine and spermine and their hydrochlorides and phosphates as a basis for the study of the interactions between polyamines and nucleic acids

AbstractThe Raman and infrared spectra of the polyamines spermidine and spermine and of their corresponding hydrochlorides and phosphates have been studied. These systems can be regarded as models of the molecular interactions between polyamines and nucleic acids, and the observed spectra are discussed in relation to this. Medium strong and strong NHCl and NHO hydrogen bonds are present in both the polyamine hydrochlorides and phosphates and the proton is predominantly located on the nitrogen atom. In the case of the phosphates, the Raman spectra indicate the formation of HPO groups, which can also interact among themselves by strong OHO hydrogen bonds.

Influence of Dissolved Water on Autoxidation of Safflower Oil during Long Time Storage

It has been found that the dissolved water (141560 ppm) in safflower oil promoted the autoxidation of the oil in air at 20 and 50°C during the long time storage (45014, 000h).When those oils were stored for 450h at 20 and 50°C, there was no difference in the degree of the autoxidation of the oil dissolved the water (141560 ppm).During the long time (100014000 h), the oil contained 14 ppm H2O was little autoxidized owing to the formation of the hydrogen bond among the dissolved water and the hydroperoxide and peroxy group (HPO and PO group). At the same conditions, the autoxidation of the oils contained 2201560 ppm H2O was accelerated by the dissolved free water.In case of the equal amount of the dissolved water in these oils at 20 and 50°C, a plot of the POV (peroxide value) vs. the equivalent number of the HPO and PO group Per the mole aumber of the dissolved water gave one straight line. Therefore, when safflower oils containing water were stored at 20 and 50°C for the long time, it is thought that the mechanism of the action of the dissolved water in these oils an the autoxidation are identical.