Objective This study aimed to efficiently reduce the release of radon from water bodies to protect the environment.Methods Based on the sizes of the experimental setup and modular float,computational fluid dynamics(CF...Objective This study aimed to efficiently reduce the release of radon from water bodies to protect the environment.Methods Based on the sizes of the experimental setup and modular float,computational fluid dynamics(CFD)was used to assess the impact of the area coverage rate,immersion depth,diffusion coefficient,and radon transfer velocity at the gas–liquid interface on radon migration and exhalation of radon-containing water.Based on the numerical simulation results,an estimation model for the radon retardation rate was constructed.The effectiveness of the CFD simulation was evaluated by comparing the experimental and simulated variation values of the radon retardation rate with the coverage area rates.Results The effect of radon transfer velocity on radon retardation in water bodies was minor and insignificant according to the appropriate value;therefore,an estimation model of the radon retardation rate of the coverage of a radon-containing water body was constructed using the synergistic impacts of three factors:area coverage rate,immersion depth,and diffusion coefficient.The deviation between the experimental and simulated results was<4.3%.Conclusion Based on the numerical simulation conditions,an estimation model of the radon retardation rate of covering floats in water bodies under the synergistic effect of multiple factors was obtained,which provides a reference for designing covering floats for radon retardation in radoncontaining water.展开更多
Background Intrauterine growth retardation(IUGR)is one of the major constraints in animal production.Our previ-ous study showed that piglets with IUGR are associated with abnormal bile acid(BA)metabolism.This study ex...Background Intrauterine growth retardation(IUGR)is one of the major constraints in animal production.Our previ-ous study showed that piglets with IUGR are associated with abnormal bile acid(BA)metabolism.This study explored whether dietary BA supplementation could improve growth performance and colonic development,function,micro-biota,and metabolites in the normal birth weight(NBW)and IUGR piglets.A total of 48 weaned piglets(24 IUGR and 24 NBW)were allocated to four groups(12 piglets per group):(i)NBW group,(ii)NBW+BA group,(iii)IUGR group,and(iv)IUGR+BA group.Samples were collected after 28 days of feeding.Results The results showed that dietary BA supplementation increased the length and weight of the colon and colon weight to body weight ratio,while decreased the plasma diamine oxidase(DAO)concentration in the NBW pig-lets(P<0.05).Dietary BA supplementation to IUGR piglets decreased(P<0.05)the plasma concentrations of D-lactate and endotoxin and colonic DAO and endotoxin,suggesting a beneficial effect on epithelial integrity.Moreover,dietary BA supplementation to NBW and IUGR piglets increased Firmicutes abundance and decreased Bacteroidetes abundance(P<0.05),whereas Lactobacillus was the dominant genus in the colon.Metabolome analysis revealed 65 and 51 differential metabolites in the colon of piglets fed a diet with/without BA,respectively,which was associated with the colonic function of IUGR piglets.Furthermore,dietary BA supplementation to IUGR piglets upregulated the expressions of CAT,GPX,SOD,Nrf1,IL-2,and IFN-γin colonic mucosa(P<0.05).Conclusions Collectively,dietary BA supplementation could improve the colonic function of IUGR piglets,which was associated with increasing proportions of potentially beneficial bacteria and metabolites.Furthermore,BA shows a promising application prospect in improving the intestinal ecosystem and health of animals.展开更多
Background:Endoplasmic reticulum(ER)stress and autophagy are implicated in the pathophysiology of intestinal inflammation;however,their roles in intrauterine growth retardation(IUGR)-induced colon inflammation are unc...Background:Endoplasmic reticulum(ER)stress and autophagy are implicated in the pathophysiology of intestinal inflammation;however,their roles in intrauterine growth retardation(IUGR)-induced colon inflammation are unclear.This study explored the protective effects of natural stilbene pterostilbene on colon inflammation using the IUGR piglets and the tumor necrosis factor alpha(TNF-α)-treated human colonic epithelial cells(Caco-2)by targeting ER stress and autophagy.Results:Both the IUGR colon and the TNF-α-treated Caco-2 cells exhibited inflammatory responses,ER stress,and impaired autophagic flux(P<0.05).The ER stress inducer tunicamycin and the autophagy inhibitor 3-methyladenine further augmented inflammatory responses and apoptosis in the TNF-α-treated Caco-2 cells(P<0.05).Conversely,pterostilbene inhibited ER stress and restored autophagic flux in the IUGR colon and the TNF-α-treated cells(P<0.05).Pterostilbene also prevented the release of inflammatory cytokines and nuclear translocation of nuclear factor kappa B p65,reduced intestinal permeability and cell apoptosis,and facilitated the expression of intestinal tight junction proteins in the IUGR colon and the TNF-α-treated cells(P<0.05).Importantly,treatment with tunicamycin or autophagosome-lysosome binding inhibitor chloroquine blocked the positive effects of pterostilbene on inflammatory response,cell apoptosis,and intestinal barrier function in the TNF-α-exposed Caco-2 cells(P<0.05).Conclusion:Pterostilbene mitigates ER stress and promotes autophagic flux,thereby improving colon inflammation and barrier dysfunction in the IUGR piglets and the TNF-α-treated Caco-2 cells.展开更多
Background:Intrauterine growth retardation(IUGR)is associated with severely impaired nutrient metabolism and intestinal development of pigs.Our previous study found that IUGR altered intestinal microbiota and metaboli...Background:Intrauterine growth retardation(IUGR)is associated with severely impaired nutrient metabolism and intestinal development of pigs.Our previous study found that IUGR altered intestinal microbiota and metabolites in the colon.However,the consequences of IUGR on bile acid metabolism in pigs remained unclear.The present study aimed to investigate the bile acid metabolism in the liver and the profile of bile acid derivatives in the colon of grow-ing pigs with IUGR using bile acid targeted metabolomics.Furthermore,we determined correlations between colonic microbiota composition and metabolites of IUGR and normal birth weight(NBW)pigs at different growth stages that were 7,21,and 28-day-old,and the average body weight(BW)of 25,50,and 100 kg of the NBW pigs.Results:The results showed that the plasma total bile acid concentration was higher(P<0.05)at the 25 kg BW stage and tended to increase(P=0.08)at 28-day-old in IUGR pigs.The hepatic gene expressions related to bile acid synthe-sis(CYP7A1,CYP27A1,and NTCP)were up-regulated(P<0.05),and the genes related to glucose and lipid metabolism(ATGL,HSL,and PC)were down-regulated(P<0.05)at the 25 kg BW stage in IUGR pigs when compared with the NBW group.Targeted metabolomics analysis showed that 29 bile acids and related compounds were detected in the colon of pigs.The colonic concentrations of dehydrolithocholic acid and apocholic acid were increased(P<0.05),while isodeoxycholic acid and 6,7-diketolithocholic acid were decreased(P<0.05)in IUGR pigs,when compared with the NBW pigs at the 25 kg BW stage.Moreover,Spearman’s correlation analysis revealed that colonic Unclassified_[Mogi-bacteriaceae],Lachnospira,and Slackia abundances were negatively correlated(P<0.05)with dehydrolithocholic acid,as well as the Unclassified_Clostridiaceae abundance with 6,7-diketolithocholic acid at the 25 kg BW stage.Conclusions:These findings suggest that IUGR could affect bile acid and glucolipid metabolism in growing pigs,especially at the 25 kg BW stage,these effects being paralleled by a modification of bile acid derivatives concentra-tions in the colonic content.The plausible links between these modified parameters are discussed.展开更多
BACKGROUND Forkhead box protein 1(FOXP1)(OMIM:605515)at chromosomal region 3p14.1 plays an important regulatory role in cell development and functions by regulating genetic expression.Earlier studies have suggested th...BACKGROUND Forkhead box protein 1(FOXP1)(OMIM:605515)at chromosomal region 3p14.1 plays an important regulatory role in cell development and functions by regulating genetic expression.Earlier studies have suggested that FOXP1,an oncogene,is capable of initiating tumorigenicity depending on the cell type.FOXP1 also plays an important role in regulating the cell development and functions of the immune system,e.g.,regulating B-cell maturation and mononuclear phagocyte differentiation,and in the occurrence and development of various immune diseases.The mRNA of this gene is widely expressed in humans,and its differential expression is related to numerous diseases.CASE SUMMARY A 5-year-old boy mainly presented with attention deficit and hyperactivity disorder and developmental retardation accompanied by gait instability and abnormal facial features(low-set ears).DNA samples were extracted from the child’s and his parents’peripheral blood to detect whole-exome sequences and whole-genome copy number variations.Results revealed heterozygous deletions of exon 6-21 of FOXP1 gene in the child.Physical examination upon admission showed that the child was generally in good condition,had a moderate nutritional status,a slightly slow response to external stimuli,equally large and equally round bilateral pupils,was sensitive to light reflection,and had poor eye contact and joint attention.He had no meaningful utterance and could not pronounce words properly.He was able to use gestures to simply express his thoughts,to perform simple actions,and to listen to instructions.He had no rash,cafe-au-lait macules,or depigmentation spots.He had thick black hair and low-set ears.He had highly sensitive skin,especially on his face and palms.He had no abnormal palm fingerprint.Cardiopulmonary and abdominal examinations revealed no abnormalities.He had normal limb muscle strength and tension.He showed normal tendon reflexes of both knees.His bilateral Babinski and meningeal irritation signs were negative.He had a normal male vulva.CONCLUSION We report the characteristic features of autism with dysphasia accompanied by mental retardation caused by FOXP1 exon deletion.This study provides a molecular basis for etiological diagnosis and treatment of the child,as well as for genetic counseling for the pedigree.展开更多
The fatigue crack growth rate (CGR) of ultra high strength steel 30CrMnSiNi2A in distilledwater at 18,35 and 55℃ were measured.It was confirmed that the temperature is strongly af-fected on the corrosion fatigue CGR ...The fatigue crack growth rate (CGR) of ultra high strength steel 30CrMnSiNi2A in distilledwater at 18,35 and 55℃ were measured.It was confirmed that the temperature is strongly af-fected on the corrosion fatigue CGR of ultra high strength steel.An expression concerning theeffects of Δ K and temperature on the CGR was proposed.The fact that the apparentactivation energy (36.6 kJ/mol) resulted from regressive analysis of CGR data was similarto the activation energy of hydrogen diffusion in γ-Fe,strongly supporting the theory ofhydrogen-assisted crack growth.The overload retardation effect was greatly reduced in cor-rosion fatigue crack growth,especially at lower frequency,e.g.,0.1 Hz.This phenomenonmight be due to the increase of the SCC component of CGR after an overload.展开更多
Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which l...Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which leads to intellectual disability and social impairment. γ-aminobutyric acid （GABA） is the major inhibitory neuro- transmitter of the mammalian central nervous system, and its metabotropic GABAB receptor has been implicated in various mental disorders. The GABAB receptor agonist baclofen has been shown to improve FXS symptoms in a mouse model and in human patients, suggesting the role of GABAB receptor on FMRP regulation. Here we investi- gated the signaling events linking the GABAB receptor and FMRP. Methods Western blot was used in this study to detect protein expression and kinase phosphorylation in cerebellar granule neurons. For key molecules in signal- ling pathway, RNAi was used in MEFs to confirm the results in neurons. Results GABAB receptor activation up- regulated cAMP response element binding protein-dependent Fmrp expression in cultured mouse cerebellar granule neurons via two distinct mechanisms： the transactivation of insulin-like growth factor-1 receptor and activation of protein kinase C. In addition, a positive allosteric modulator of the GABAB receptor, CGP7930, stimulated Fmrp expression in neurons. Conclusion These results suggest a role for GABAB receptor in Fmrp regulation and a po- tential interest of GABAB receptor signaling in FXS improvement.展开更多
This paper studies the retardation process for photosensitized oxidation of 9,10-diphenylanthracene（9,10-DPA） induced by hypocrellin A （HA） as a sensitizer in the presence ofpraseodymium ion (Pr<sup>3+</s...This paper studies the retardation process for photosensitized oxidation of 9,10-diphenylanthracene（9,10-DPA） induced by hypocrellin A （HA） as a sensitizer in the presence ofpraseodymium ion (Pr<sup>3+</sup>).Experimental result shows that the prompt fluorescence of HA can be quenched byPr<sup>3+</sup> in methanol.Measurement of fluorescence lifetime reveals that it remains constant with increasing con-centration of Pr<sup>3+</sup>,thus a static quenching character is indicated.The thermally induced delayed fluorescenceof HA can also be quenched effectively by the Pr<sup>3+</sup>-HA complex.The delayed fluorescence lifetime is re-duced from 1744±50 ns to 700±50 ns and 500±50 ns in the presence of oxygen and Pr<sup>3+</sup> respectively,thusthe quenching of delayed fluorescence is of dynamic character.As compared with the double reciprocal rela-tionship of concentration between the oxidation product derived from singlet oxygen and the reactant,it showsthat the Pr<sup>3+</sup>-HA complex can quench not only the excited triplet of HA but also the singlet oxygen andtherefore the photosensitized oxidation of 9,10-DPA is retarded efficiently.展开更多
128 children of mental retardation were diagnosed in accordance with the diagnostic stand-ards proposed by WHO in 1985. The patients were treated compositely with acupuncture, auriculo-acupoint pellet pressure and her...128 children of mental retardation were diagnosed in accordance with the diagnostic stand-ards proposed by WHO in 1985. The patients were treated compositely with acupuncture, auriculo-acupoint pellet pressure and herbal plasters on acupoints, bringing about improved mental developments in intelligence quotient (IQ) and social adaptation behaviour (SAB), as evidenced by recognized intelligence tests for children.展开更多
An effective Hamiltonian including current-current coupling from the global color symmetry model is -R2 2derived.Retardation effects are introduced by the factor ( R/ ) e ,instead of δ (r) in the correlation kernel,f...An effective Hamiltonian including current-current coupling from the global color symmetry model is -R2 2derived.Retardation effects are introduced by the factor ( R/ ) e ,instead of δ (r) in the correlation kernel,from which the retardation gap equation with α-α coupling in the 3po vacuum is obtained,qq condensations of different retardation parameters R with or without the α-α term are calculated.The results show the effects of retardation,and indicate that the typical value of R is about 2 fm-1 at reasonable value of qq condensation.And while taking typical value 1 fm-1 of R,the condensation <qq>1/3 is about 13% larger than that with no retardation effect.With the α-αterms,the condensation (qq) 1/3 is about 17%o larger than that without it for all values of the parameter R.This shows that the retardation effects and the α-α terms are important for further studying in the Iow-energy region.展开更多
The utero-placental-fetal circulation (UPFC) of 150 subjects duringsecond and third trimester was examined by using color DOppler. Of them 89 were normal woman and 58 were patients with intrauterine growth retardation...The utero-placental-fetal circulation (UPFC) of 150 subjects duringsecond and third trimester was examined by using color DOppler. Of them 89 were normal woman and 58 were patients with intrauterine growth retardation (IUGR). Our results showed that UPFC was increased gradually during normal pregnant period. In IUGR patients it was revealed that TAV and Q of UmA,UmV and UtA decreased at 20th week of gestation, especially after 30th week.PI, RI and S/D ratio of UmA were increased, but TAV, Q of UmA and UmV were markly reduced, so was UtA. Pl were increased, but the changes of RI,S/D ratio in UtA were not significant. HemodynamicaI findings of UmA,UmV and UtA were abnormal in 92. 53 % of IUGR patients,Only 81. 03% present abnormal S/D ratio of UmA (P<0. 01) and the difference was statistically significant.Maternal serum E,, HPL level in IUGR were significantly lower than that of thenormal. 6KP level was reduced, TXB,/6KP ratio was significantly increased.TXB2/6KP ratio was markedIy related with TAV, Q of UmA, UmV and UtA.Our results suggested that using color doppler ultrasound for examination of hemodynamical changes of UmA, UmV and UtA could revealed UPFC function directly. It is one of the best methods for monitoring IUGR and might be used forearly diagnosis of IUGR. The main pathophysiological changes of IUGR were UPFC obstruction and placental disfunction.展开更多
In order to evaluate the predictive value of maternal plasma fibronectin (FN) concentration at 24-34 weeks on fetal intrauterine growth retardation (IUGR), a prospective double-blinded study was performed. The materna...In order to evaluate the predictive value of maternal plasma fibronectin (FN) concentration at 24-34 weeks on fetal intrauterine growth retardation (IUGR), a prospective double-blinded study was performed. The maternal plasma FN concentrations were measured by using a rate nephelometric procedure in the 130 initial normal nulliparous pregnant woman at 24-34 gestational weeks. The outcome of pregnancies and birth weight of their infants were followed up. IUGR was defined as that the birth weight was less than the 10th percentile for gestational age. The receiver operating characteristic curves and predictive values of FN predicting on outcome of pregnancy with IUGR were analyzed. The results showed that: (1) In a cohort of 130 initially normal nulliparous pregnant women, IUGR occurred in 14 cases during the follow-up; (2) The plasma FN levels in the women with IUGR (467.58±104.43 mg/L) were significantly higher than in the normal control group (299.44±105.55 mg/L, P<0.01). However, there was no significant difference in the mean maternal age, gravidity, sampling gestational ages, delivering gestational ages between the two groups (P>0.05); (3) The areas under ROC curve for predicting the outcome of pregnancy in IUGR was 0.893; (4) At the cut point of 475 mg/L FN level, the sensitivity, specificity, positive predictive value, negative predictive value and Kappa index for predicting the outcomes of pregnancy in IUGR were 57.14 %, 95.69 %, 61.54 %, 94.87 %, 0.5455 respectively. It was concluded that the maternal plasma FN might be used as an earlier predictor for screening of IUGR.展开更多
Background: The mental, physical and social impediments cause limitation of chances in normal life as an equal level with others of the community;particularly in relation to maintain good oral hygiene and periodontal ...Background: The mental, physical and social impediments cause limitation of chances in normal life as an equal level with others of the community;particularly in relation to maintain good oral hygiene and periodontal health among the disabled patients who were receiving fixed partial denture. So the present study was performed to evaluate the periodontal tissue status among mental retardation patients with fixed prosthodontic appliances. Subjects and Methods: A total of 400 patients between the ages 18 and 50 years were clinically selected from outpatient clinics, college of dentistry, King Khalid University and rehabilitation center in Abha city, Saudi Arabia. They were divided into two equal groups as the following: group I: Two hundred mental retardation patients without fixed prosthodontic appliances (control group) and, group II: Two hundred mental retardation patients had fixed prosthodontic appliances for at least a year ago. A complete periodontal clinical examination was performed and the following indices were recorded: plaque index (PLI), gingival index (GI), and clinical attachment loss (CAL). All data was recorded and analyzed by ANOVA test. Results: The clinical results of the present study confirmed the relationship among the mental retardation, fixed prosthodontic appliances and destruction of periodontal tissues. It has been found that the severity of periodontal disease increases among the study group compared to the control group. Statistically significant differences were found in PLI, GI and CAL in the comparison between group I and II (p Conclusion: There was a negative relationship between mental retardation with a status of periodontal tissues and oral hygiene among the patients under fixed prosthodontic management.展开更多
Background: Mental retardation is an important condition in children. People in the community need to be aware of the presence, need to act and prevent this problem. Mental retardation means mental growth of the child...Background: Mental retardation is an important condition in children. People in the community need to be aware of the presence, need to act and prevent this problem. Mental retardation means mental growth of the child is not at par with physical growth. Mental retardation is calculated as intelligence quationent. (IQ) = Mental age/chronological age × 100. There are causes and can be categorized as prenatal, natal and postnatal factors. Mental retardation is classified as Mild Mental retardation IQ of 51 - 70;Moderate Mental retardation IQ of 36 - 50;Severe Mental retardation IQ of 21 - 35;Profound Mental retardation IQ of less than 20. IQ of 71 - 89 is designated as borderline mental retardation. Objectives: Analyzing the procured data creates awareness in the society regarding mental retardation and its burden to the society. Results: The analysis is done using the data provided from the office of Deputy Director, Department of Public Instruction, Sarvashikshana Abhiyana (SSA) Shimoga District [1]. 555 children were having mental retardation ranging from mild to profound severity. The total number of children with various disabilities was 1185, mental retardation alone was nearing 50% of the total disabilities. Conclusion: 50% of total disability was found to be mental retardation which needs to proliferate.展开更多
In paper the role of excess pressures in cata- genic processes of the South-Caspian basin (SCB) is considered. The results of the carried out researches taking into account world ex- perience on the given problem allo...In paper the role of excess pressures in cata- genic processes of the South-Caspian basin (SCB) is considered. The results of the carried out researches taking into account world ex- perience on the given problem allow to con- clude, that SCB (mainly its deep-water part), as well as a number of other basins of the world with overpressures, is characterized by retarda- tion of processes cracking of kerogen and oil, and also reaction of transformation of clay minerals. Periodic intensification of these pro- cesses can provoke development of diapirs and mud volcanoes, which are the centers of pulse unloading of a hydrocarbon products from sys- tem. The conclusion about high prospects of revealing of hydrocarbon accumulations in deep buried deposits in overpressured basins is made.展开更多
Objective To investigate the relationship between intrauterine growth retardation (IUGR) and endocrine parameters so as to assess the effects or the main endocrine ractors on IUGR. The concentrations of growth hormone...Objective To investigate the relationship between intrauterine growth retardation (IUGR) and endocrine parameters so as to assess the effects or the main endocrine ractors on IUGR. The concentrations of growth hormone(GH), insulin, T3, T4 and TSH were measured in umbilical cord blood, amniotic fluid and maternal serum.Methods The samples were collected from 23 pregnant women who were diagnosed as the full term IUGR, 42 normal full term pregnant women with normal infants’ weight were taken as control. Growth hormone and insulin were measured by radioimmunoassay. T3, T4 and TSH were investigated by micro-radioimmunoassay. Results The concentrations of growth hormone, insulin and T4 in umbilical cord blood were lower in IUGR than that in control group(GH4. 63μ/L vs 7. o1μg/L, insulin 1o. 68μIU/ml vs 31. 44μIU/ml, T487. 39nmol/L vs 138. 1onmol/L. P <o. o5, o. o5 and o. o5, respectively). The TSH concentration in umbilical cord blood was higher in IUGR than in control group (1o. 84μmIU/L vs 5. 75μmIU/L, P <o. o1 ). The concentration of growth hormone in maternal serum and the concentration of insulin in amniotic fluid were also lower in IUGR group than in control group(GH 1. 77μg/L vs 2. 74μg/L,P <o. o1, insulin 5. 84μIU/ml vs 15. 64μIU/ml, P <o. o1). Conclusion This study confirms that full term neonates with IUGR are abnormal in endocrine factors. The inadequacy of growth hormone may be one of the causes of IUGR. The relatlve scarcity of growth hormone and insulin seems to be a factor to compromise the fetus’ metabolism. Besides, the early hypothyrosis of infants with IUGR might protect them from unfavorable environment in the uterine.展开更多
A 3-year-old female patient born of consanguineous parents presented to the (development and behavioral clinic) in Taif children hospital, Western Saudai Arabia, her mother complained that her daughter had speech dela...A 3-year-old female patient born of consanguineous parents presented to the (development and behavioral clinic) in Taif children hospital, Western Saudai Arabia, her mother complained that her daughter had speech delay, no eye to eye contact, and was performing stereotyped behaviors (hand flapping). The girl developed convulsions at the age of 3 months and was on anticonvulsant medication since that age;her convulsions were controlled on anti-epileptic treatment. Family history revealed that the girl had a 6-year-old male sibling who developed convulsions at the age of 4 months and is on antiepileptic medications;the boy suffered also from speech delay, absent social interaction, and repetitive behaviors. On examination the girl had characteristic features of angio-fibromas, hypo-pigmented macules on the trunk and legs, and moreover the boy had similar skin features plus hypo-pigmented tufts of hair. Both cases were diagnosed as Autistic spectrum disorder, tuberous sclerosis, and mental retardation. The family needed genetic counseling, while both cases needed as soon as possible behavioral and educational strategies.展开更多
To calibrate the phase retardance of a Liquid crystal variable retarder(LCVR),its birefringence dispersion characteristic was analyzed,and the Support vector machines(SVM) algorithm was adopted to establish the predic...To calibrate the phase retardance of a Liquid crystal variable retarder(LCVR),its birefringence dispersion characteristic was analyzed,and the Support vector machines(SVM) algorithm was adopted to establish the prediction model.The obtained SVM decision function was used as a part of LCVR phase retardance,which was generated by the driving voltage.The experimental verification was carried out with a 568 nm laser.The results show that the deviation of the experimental value and the theoretical value is about 0.0061λ.SVM method could be used as an effective method for LCVR phase retardance characteristic calibration.展开更多
The flame-retarded polycarbonate(PC) has been made with octaphenyl polyhedral silsesquioxane(OPS) and/or caged bicyclic phosphate(Trimer).Thermal gravimetric analysis(TGA),Fourier-transform infrared(FTIR),TGA-FTIR,lim...The flame-retarded polycarbonate(PC) has been made with octaphenyl polyhedral silsesquioxane(OPS) and/or caged bicyclic phosphate(Trimer).Thermal gravimetric analysis(TGA),Fourier-transform infrared(FTIR),TGA-FTIR,limiting oxygen index(LOI),and mechanical tests have been employed to characterize the modified PC.The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si.The role of OPS and Trimer in PC degradation are different:OPS participates in the charring of PC,while Trimer makes PC degrade in advance.In addition,OPS and Trimer induced obvious differences in the mechanical properties of PC.展开更多
It is an established fact that huge quantities of water are lost from lakes, reservoirs and soils by evaporation. This assumes greater significance in arid and semi-arid regions around the globe when a general scarcit...It is an established fact that huge quantities of water are lost from lakes, reservoirs and soils by evaporation. This assumes greater significance in arid and semi-arid regions around the globe when a general scarcity of water is compounded by high evaporation loss from the open water surfaces of lakes and reservoirs. The use of surface covering by a monomolecular film to reduce evaporation loss from large open water surfaces offers the greatest promise among all currently available techniques. This is the only system that retains the water surface in a state that does not interfere with other uses of the body of water such as boating, navigation recreation, fish, and wildlife propagation. Various experiments and field trials worldwide have proven conclusively that the fatty alcohols and their emulsions effectively retard water evaporation and result in saving to the tune of about 20% to 50%. An experiment was carried out at the Aji Reservoir (India) using a mixture of Cetyl and Stearyl alcohol that confirmed 19.26% saving in evaporation loss. During this six-month trial, about 0.18 mcum of water was saved which otherwise might have evaporated.展开更多
基金supported by a grant from the National Natural Science Foundation of China(Grant nos.31770907,31640022)the National Natural Science Foundation of China(Grant No.11575080)the Natural Science Foundation of Hunan Province,China(Grant No.2022JJ30482).
文摘Objective This study aimed to efficiently reduce the release of radon from water bodies to protect the environment.Methods Based on the sizes of the experimental setup and modular float,computational fluid dynamics(CFD)was used to assess the impact of the area coverage rate,immersion depth,diffusion coefficient,and radon transfer velocity at the gas–liquid interface on radon migration and exhalation of radon-containing water.Based on the numerical simulation results,an estimation model for the radon retardation rate was constructed.The effectiveness of the CFD simulation was evaluated by comparing the experimental and simulated variation values of the radon retardation rate with the coverage area rates.Results The effect of radon transfer velocity on radon retardation in water bodies was minor and insignificant according to the appropriate value;therefore,an estimation model of the radon retardation rate of the coverage of a radon-containing water body was constructed using the synergistic impacts of three factors:area coverage rate,immersion depth,and diffusion coefficient.The deviation between the experimental and simulated results was<4.3%.Conclusion Based on the numerical simulation conditions,an estimation model of the radon retardation rate of covering floats in water bodies under the synergistic effect of multiple factors was obtained,which provides a reference for designing covering floats for radon retardation in radoncontaining water.
基金the Key Project of Regional Innovation and Development Joint Fund of the National Natural Science Foundation of China(U20A2056)the Special Funds for Construction of Innovative Provinces in Hunan Province(2019RS3022).
文摘Background Intrauterine growth retardation(IUGR)is one of the major constraints in animal production.Our previ-ous study showed that piglets with IUGR are associated with abnormal bile acid(BA)metabolism.This study explored whether dietary BA supplementation could improve growth performance and colonic development,function,micro-biota,and metabolites in the normal birth weight(NBW)and IUGR piglets.A total of 48 weaned piglets(24 IUGR and 24 NBW)were allocated to four groups(12 piglets per group):(i)NBW group,(ii)NBW+BA group,(iii)IUGR group,and(iv)IUGR+BA group.Samples were collected after 28 days of feeding.Results The results showed that dietary BA supplementation increased the length and weight of the colon and colon weight to body weight ratio,while decreased the plasma diamine oxidase(DAO)concentration in the NBW pig-lets(P<0.05).Dietary BA supplementation to IUGR piglets decreased(P<0.05)the plasma concentrations of D-lactate and endotoxin and colonic DAO and endotoxin,suggesting a beneficial effect on epithelial integrity.Moreover,dietary BA supplementation to NBW and IUGR piglets increased Firmicutes abundance and decreased Bacteroidetes abundance(P<0.05),whereas Lactobacillus was the dominant genus in the colon.Metabolome analysis revealed 65 and 51 differential metabolites in the colon of piglets fed a diet with/without BA,respectively,which was associated with the colonic function of IUGR piglets.Furthermore,dietary BA supplementation to IUGR piglets upregulated the expressions of CAT,GPX,SOD,Nrf1,IL-2,and IFN-γin colonic mucosa(P<0.05).Conclusions Collectively,dietary BA supplementation could improve the colonic function of IUGR piglets,which was associated with increasing proportions of potentially beneficial bacteria and metabolites.Furthermore,BA shows a promising application prospect in improving the intestinal ecosystem and health of animals.
基金supported by grants from the National Natural Science Foundation of China (Nos.31902197 and 31802094)the Natural Science Foundation of Jiangsu Province (No.BK20180531)。
文摘Background:Endoplasmic reticulum(ER)stress and autophagy are implicated in the pathophysiology of intestinal inflammation;however,their roles in intrauterine growth retardation(IUGR)-induced colon inflammation are unclear.This study explored the protective effects of natural stilbene pterostilbene on colon inflammation using the IUGR piglets and the tumor necrosis factor alpha(TNF-α)-treated human colonic epithelial cells(Caco-2)by targeting ER stress and autophagy.Results:Both the IUGR colon and the TNF-α-treated Caco-2 cells exhibited inflammatory responses,ER stress,and impaired autophagic flux(P<0.05).The ER stress inducer tunicamycin and the autophagy inhibitor 3-methyladenine further augmented inflammatory responses and apoptosis in the TNF-α-treated Caco-2 cells(P<0.05).Conversely,pterostilbene inhibited ER stress and restored autophagic flux in the IUGR colon and the TNF-α-treated cells(P<0.05).Pterostilbene also prevented the release of inflammatory cytokines and nuclear translocation of nuclear factor kappa B p65,reduced intestinal permeability and cell apoptosis,and facilitated the expression of intestinal tight junction proteins in the IUGR colon and the TNF-α-treated cells(P<0.05).Importantly,treatment with tunicamycin or autophagosome-lysosome binding inhibitor chloroquine blocked the positive effects of pterostilbene on inflammatory response,cell apoptosis,and intestinal barrier function in the TNF-α-exposed Caco-2 cells(P<0.05).Conclusion:Pterostilbene mitigates ER stress and promotes autophagic flux,thereby improving colon inflammation and barrier dysfunction in the IUGR piglets and the TNF-α-treated Caco-2 cells.
基金supported by the National Natural Science Foundation of China(U20A2056)Special Funds for Construction of Innovative Provinces in Hunan Province(2019RS3022).
文摘Background:Intrauterine growth retardation(IUGR)is associated with severely impaired nutrient metabolism and intestinal development of pigs.Our previous study found that IUGR altered intestinal microbiota and metabolites in the colon.However,the consequences of IUGR on bile acid metabolism in pigs remained unclear.The present study aimed to investigate the bile acid metabolism in the liver and the profile of bile acid derivatives in the colon of grow-ing pigs with IUGR using bile acid targeted metabolomics.Furthermore,we determined correlations between colonic microbiota composition and metabolites of IUGR and normal birth weight(NBW)pigs at different growth stages that were 7,21,and 28-day-old,and the average body weight(BW)of 25,50,and 100 kg of the NBW pigs.Results:The results showed that the plasma total bile acid concentration was higher(P<0.05)at the 25 kg BW stage and tended to increase(P=0.08)at 28-day-old in IUGR pigs.The hepatic gene expressions related to bile acid synthe-sis(CYP7A1,CYP27A1,and NTCP)were up-regulated(P<0.05),and the genes related to glucose and lipid metabolism(ATGL,HSL,and PC)were down-regulated(P<0.05)at the 25 kg BW stage in IUGR pigs when compared with the NBW group.Targeted metabolomics analysis showed that 29 bile acids and related compounds were detected in the colon of pigs.The colonic concentrations of dehydrolithocholic acid and apocholic acid were increased(P<0.05),while isodeoxycholic acid and 6,7-diketolithocholic acid were decreased(P<0.05)in IUGR pigs,when compared with the NBW pigs at the 25 kg BW stage.Moreover,Spearman’s correlation analysis revealed that colonic Unclassified_[Mogi-bacteriaceae],Lachnospira,and Slackia abundances were negatively correlated(P<0.05)with dehydrolithocholic acid,as well as the Unclassified_Clostridiaceae abundance with 6,7-diketolithocholic acid at the 25 kg BW stage.Conclusions:These findings suggest that IUGR could affect bile acid and glucolipid metabolism in growing pigs,especially at the 25 kg BW stage,these effects being paralleled by a modification of bile acid derivatives concentra-tions in the colonic content.The plausible links between these modified parameters are discussed.
基金Supported by Natural Science Foundation of Jilin Province,No.20200201486JC.
文摘BACKGROUND Forkhead box protein 1(FOXP1)(OMIM:605515)at chromosomal region 3p14.1 plays an important regulatory role in cell development and functions by regulating genetic expression.Earlier studies have suggested that FOXP1,an oncogene,is capable of initiating tumorigenicity depending on the cell type.FOXP1 also plays an important role in regulating the cell development and functions of the immune system,e.g.,regulating B-cell maturation and mononuclear phagocyte differentiation,and in the occurrence and development of various immune diseases.The mRNA of this gene is widely expressed in humans,and its differential expression is related to numerous diseases.CASE SUMMARY A 5-year-old boy mainly presented with attention deficit and hyperactivity disorder and developmental retardation accompanied by gait instability and abnormal facial features(low-set ears).DNA samples were extracted from the child’s and his parents’peripheral blood to detect whole-exome sequences and whole-genome copy number variations.Results revealed heterozygous deletions of exon 6-21 of FOXP1 gene in the child.Physical examination upon admission showed that the child was generally in good condition,had a moderate nutritional status,a slightly slow response to external stimuli,equally large and equally round bilateral pupils,was sensitive to light reflection,and had poor eye contact and joint attention.He had no meaningful utterance and could not pronounce words properly.He was able to use gestures to simply express his thoughts,to perform simple actions,and to listen to instructions.He had no rash,cafe-au-lait macules,or depigmentation spots.He had thick black hair and low-set ears.He had highly sensitive skin,especially on his face and palms.He had no abnormal palm fingerprint.Cardiopulmonary and abdominal examinations revealed no abnormalities.He had normal limb muscle strength and tension.He showed normal tendon reflexes of both knees.His bilateral Babinski and meningeal irritation signs were negative.He had a normal male vulva.CONCLUSION We report the characteristic features of autism with dysphasia accompanied by mental retardation caused by FOXP1 exon deletion.This study provides a molecular basis for etiological diagnosis and treatment of the child,as well as for genetic counseling for the pedigree.
文摘The fatigue crack growth rate (CGR) of ultra high strength steel 30CrMnSiNi2A in distilledwater at 18,35 and 55℃ were measured.It was confirmed that the temperature is strongly af-fected on the corrosion fatigue CGR of ultra high strength steel.An expression concerning theeffects of Δ K and temperature on the CGR was proposed.The fact that the apparentactivation energy (36.6 kJ/mol) resulted from regressive analysis of CGR data was similarto the activation energy of hydrogen diffusion in γ-Fe,strongly supporting the theory ofhydrogen-assisted crack growth.The overload retardation effect was greatly reduced in cor-rosion fatigue crack growth,especially at lower frequency,e.g.,0.1 Hz.This phenomenonmight be due to the increase of the SCC component of CGR after an overload.
文摘Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which leads to intellectual disability and social impairment. γ-aminobutyric acid （GABA） is the major inhibitory neuro- transmitter of the mammalian central nervous system, and its metabotropic GABAB receptor has been implicated in various mental disorders. The GABAB receptor agonist baclofen has been shown to improve FXS symptoms in a mouse model and in human patients, suggesting the role of GABAB receptor on FMRP regulation. Here we investi- gated the signaling events linking the GABAB receptor and FMRP. Methods Western blot was used in this study to detect protein expression and kinase phosphorylation in cerebellar granule neurons. For key molecules in signal- ling pathway, RNAi was used in MEFs to confirm the results in neurons. Results GABAB receptor activation up- regulated cAMP response element binding protein-dependent Fmrp expression in cultured mouse cerebellar granule neurons via two distinct mechanisms： the transactivation of insulin-like growth factor-1 receptor and activation of protein kinase C. In addition, a positive allosteric modulator of the GABAB receptor, CGP7930, stimulated Fmrp expression in neurons. Conclusion These results suggest a role for GABAB receptor in Fmrp regulation and a po- tential interest of GABAB receptor signaling in FXS improvement.
文摘This paper studies the retardation process for photosensitized oxidation of 9,10-diphenylanthracene（9,10-DPA） induced by hypocrellin A （HA） as a sensitizer in the presence ofpraseodymium ion (Pr<sup>3+</sup>).Experimental result shows that the prompt fluorescence of HA can be quenched byPr<sup>3+</sup> in methanol.Measurement of fluorescence lifetime reveals that it remains constant with increasing con-centration of Pr<sup>3+</sup>,thus a static quenching character is indicated.The thermally induced delayed fluorescenceof HA can also be quenched effectively by the Pr<sup>3+</sup>-HA complex.The delayed fluorescence lifetime is re-duced from 1744±50 ns to 700±50 ns and 500±50 ns in the presence of oxygen and Pr<sup>3+</sup> respectively,thusthe quenching of delayed fluorescence is of dynamic character.As compared with the double reciprocal rela-tionship of concentration between the oxidation product derived from singlet oxygen and the reactant,it showsthat the Pr<sup>3+</sup>-HA complex can quench not only the excited triplet of HA but also the singlet oxygen andtherefore the photosensitized oxidation of 9,10-DPA is retarded efficiently.
文摘128 children of mental retardation were diagnosed in accordance with the diagnostic stand-ards proposed by WHO in 1985. The patients were treated compositely with acupuncture, auriculo-acupoint pellet pressure and herbal plasters on acupoints, bringing about improved mental developments in intelligence quotient (IQ) and social adaptation behaviour (SAB), as evidenced by recognized intelligence tests for children.
文摘An effective Hamiltonian including current-current coupling from the global color symmetry model is -R2 2derived.Retardation effects are introduced by the factor ( R/ ) e ,instead of δ (r) in the correlation kernel,from which the retardation gap equation with α-α coupling in the 3po vacuum is obtained,qq condensations of different retardation parameters R with or without the α-α term are calculated.The results show the effects of retardation,and indicate that the typical value of R is about 2 fm-1 at reasonable value of qq condensation.And while taking typical value 1 fm-1 of R,the condensation <qq>1/3 is about 13% larger than that with no retardation effect.With the α-αterms,the condensation (qq) 1/3 is about 17%o larger than that without it for all values of the parameter R.This shows that the retardation effects and the α-α terms are important for further studying in the Iow-energy region.
文摘The utero-placental-fetal circulation (UPFC) of 150 subjects duringsecond and third trimester was examined by using color DOppler. Of them 89 were normal woman and 58 were patients with intrauterine growth retardation (IUGR). Our results showed that UPFC was increased gradually during normal pregnant period. In IUGR patients it was revealed that TAV and Q of UmA,UmV and UtA decreased at 20th week of gestation, especially after 30th week.PI, RI and S/D ratio of UmA were increased, but TAV, Q of UmA and UmV were markly reduced, so was UtA. Pl were increased, but the changes of RI,S/D ratio in UtA were not significant. HemodynamicaI findings of UmA,UmV and UtA were abnormal in 92. 53 % of IUGR patients,Only 81. 03% present abnormal S/D ratio of UmA (P<0. 01) and the difference was statistically significant.Maternal serum E,, HPL level in IUGR were significantly lower than that of thenormal. 6KP level was reduced, TXB,/6KP ratio was significantly increased.TXB2/6KP ratio was markedIy related with TAV, Q of UmA, UmV and UtA.Our results suggested that using color doppler ultrasound for examination of hemodynamical changes of UmA, UmV and UtA could revealed UPFC function directly. It is one of the best methods for monitoring IUGR and might be used forearly diagnosis of IUGR. The main pathophysiological changes of IUGR were UPFC obstruction and placental disfunction.
文摘In order to evaluate the predictive value of maternal plasma fibronectin (FN) concentration at 24-34 weeks on fetal intrauterine growth retardation (IUGR), a prospective double-blinded study was performed. The maternal plasma FN concentrations were measured by using a rate nephelometric procedure in the 130 initial normal nulliparous pregnant woman at 24-34 gestational weeks. The outcome of pregnancies and birth weight of their infants were followed up. IUGR was defined as that the birth weight was less than the 10th percentile for gestational age. The receiver operating characteristic curves and predictive values of FN predicting on outcome of pregnancy with IUGR were analyzed. The results showed that: (1) In a cohort of 130 initially normal nulliparous pregnant women, IUGR occurred in 14 cases during the follow-up; (2) The plasma FN levels in the women with IUGR (467.58±104.43 mg/L) were significantly higher than in the normal control group (299.44±105.55 mg/L, P<0.01). However, there was no significant difference in the mean maternal age, gravidity, sampling gestational ages, delivering gestational ages between the two groups (P>0.05); (3) The areas under ROC curve for predicting the outcome of pregnancy in IUGR was 0.893; (4) At the cut point of 475 mg/L FN level, the sensitivity, specificity, positive predictive value, negative predictive value and Kappa index for predicting the outcomes of pregnancy in IUGR were 57.14 %, 95.69 %, 61.54 %, 94.87 %, 0.5455 respectively. It was concluded that the maternal plasma FN might be used as an earlier predictor for screening of IUGR.
文摘Background: The mental, physical and social impediments cause limitation of chances in normal life as an equal level with others of the community;particularly in relation to maintain good oral hygiene and periodontal health among the disabled patients who were receiving fixed partial denture. So the present study was performed to evaluate the periodontal tissue status among mental retardation patients with fixed prosthodontic appliances. Subjects and Methods: A total of 400 patients between the ages 18 and 50 years were clinically selected from outpatient clinics, college of dentistry, King Khalid University and rehabilitation center in Abha city, Saudi Arabia. They were divided into two equal groups as the following: group I: Two hundred mental retardation patients without fixed prosthodontic appliances (control group) and, group II: Two hundred mental retardation patients had fixed prosthodontic appliances for at least a year ago. A complete periodontal clinical examination was performed and the following indices were recorded: plaque index (PLI), gingival index (GI), and clinical attachment loss (CAL). All data was recorded and analyzed by ANOVA test. Results: The clinical results of the present study confirmed the relationship among the mental retardation, fixed prosthodontic appliances and destruction of periodontal tissues. It has been found that the severity of periodontal disease increases among the study group compared to the control group. Statistically significant differences were found in PLI, GI and CAL in the comparison between group I and II (p Conclusion: There was a negative relationship between mental retardation with a status of periodontal tissues and oral hygiene among the patients under fixed prosthodontic management.
文摘Background: Mental retardation is an important condition in children. People in the community need to be aware of the presence, need to act and prevent this problem. Mental retardation means mental growth of the child is not at par with physical growth. Mental retardation is calculated as intelligence quationent. (IQ) = Mental age/chronological age × 100. There are causes and can be categorized as prenatal, natal and postnatal factors. Mental retardation is classified as Mild Mental retardation IQ of 51 - 70;Moderate Mental retardation IQ of 36 - 50;Severe Mental retardation IQ of 21 - 35;Profound Mental retardation IQ of less than 20. IQ of 71 - 89 is designated as borderline mental retardation. Objectives: Analyzing the procured data creates awareness in the society regarding mental retardation and its burden to the society. Results: The analysis is done using the data provided from the office of Deputy Director, Department of Public Instruction, Sarvashikshana Abhiyana (SSA) Shimoga District [1]. 555 children were having mental retardation ranging from mild to profound severity. The total number of children with various disabilities was 1185, mental retardation alone was nearing 50% of the total disabilities. Conclusion: 50% of total disability was found to be mental retardation which needs to proliferate.
文摘In paper the role of excess pressures in cata- genic processes of the South-Caspian basin (SCB) is considered. The results of the carried out researches taking into account world ex- perience on the given problem allow to con- clude, that SCB (mainly its deep-water part), as well as a number of other basins of the world with overpressures, is characterized by retarda- tion of processes cracking of kerogen and oil, and also reaction of transformation of clay minerals. Periodic intensification of these pro- cesses can provoke development of diapirs and mud volcanoes, which are the centers of pulse unloading of a hydrocarbon products from sys- tem. The conclusion about high prospects of revealing of hydrocarbon accumulations in deep buried deposits in overpressured basins is made.
文摘Objective To investigate the relationship between intrauterine growth retardation (IUGR) and endocrine parameters so as to assess the effects or the main endocrine ractors on IUGR. The concentrations of growth hormone(GH), insulin, T3, T4 and TSH were measured in umbilical cord blood, amniotic fluid and maternal serum.Methods The samples were collected from 23 pregnant women who were diagnosed as the full term IUGR, 42 normal full term pregnant women with normal infants’ weight were taken as control. Growth hormone and insulin were measured by radioimmunoassay. T3, T4 and TSH were investigated by micro-radioimmunoassay. Results The concentrations of growth hormone, insulin and T4 in umbilical cord blood were lower in IUGR than that in control group(GH4. 63μ/L vs 7. o1μg/L, insulin 1o. 68μIU/ml vs 31. 44μIU/ml, T487. 39nmol/L vs 138. 1onmol/L. P <o. o5, o. o5 and o. o5, respectively). The TSH concentration in umbilical cord blood was higher in IUGR than in control group (1o. 84μmIU/L vs 5. 75μmIU/L, P <o. o1 ). The concentration of growth hormone in maternal serum and the concentration of insulin in amniotic fluid were also lower in IUGR group than in control group(GH 1. 77μg/L vs 2. 74μg/L,P <o. o1, insulin 5. 84μIU/ml vs 15. 64μIU/ml, P <o. o1). Conclusion This study confirms that full term neonates with IUGR are abnormal in endocrine factors. The inadequacy of growth hormone may be one of the causes of IUGR. The relatlve scarcity of growth hormone and insulin seems to be a factor to compromise the fetus’ metabolism. Besides, the early hypothyrosis of infants with IUGR might protect them from unfavorable environment in the uterine.
文摘A 3-year-old female patient born of consanguineous parents presented to the (development and behavioral clinic) in Taif children hospital, Western Saudai Arabia, her mother complained that her daughter had speech delay, no eye to eye contact, and was performing stereotyped behaviors (hand flapping). The girl developed convulsions at the age of 3 months and was on anticonvulsant medication since that age;her convulsions were controlled on anti-epileptic treatment. Family history revealed that the girl had a 6-year-old male sibling who developed convulsions at the age of 4 months and is on antiepileptic medications;the boy suffered also from speech delay, absent social interaction, and repetitive behaviors. On examination the girl had characteristic features of angio-fibromas, hypo-pigmented macules on the trunk and legs, and moreover the boy had similar skin features plus hypo-pigmented tufts of hair. Both cases were diagnosed as Autistic spectrum disorder, tuberous sclerosis, and mental retardation. The family needed genetic counseling, while both cases needed as soon as possible behavioral and educational strategies.
基金supported by the National Natural Science Foundation of China ( grant no. 91338116)the National Key Basic Research and Development Program ( 973 Plan) ( grant no. 613225)
文摘To calibrate the phase retardance of a Liquid crystal variable retarder(LCVR),its birefringence dispersion characteristic was analyzed,and the Support vector machines(SVM) algorithm was adopted to establish the prediction model.The obtained SVM decision function was used as a part of LCVR phase retardance,which was generated by the driving voltage.The experimental verification was carried out with a 568 nm laser.The results show that the deviation of the experimental value and the theoretical value is about 0.0061λ.SVM method could be used as an effective method for LCVR phase retardance characteristic calibration.
基金Sponsored by the National High Technology Research and Development Program of China("863"Program)(2007AA03Z538)
文摘The flame-retarded polycarbonate(PC) has been made with octaphenyl polyhedral silsesquioxane(OPS) and/or caged bicyclic phosphate(Trimer).Thermal gravimetric analysis(TGA),Fourier-transform infrared(FTIR),TGA-FTIR,limiting oxygen index(LOI),and mechanical tests have been employed to characterize the modified PC.The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si.The role of OPS and Trimer in PC degradation are different:OPS participates in the charring of PC,while Trimer makes PC degrade in advance.In addition,OPS and Trimer induced obvious differences in the mechanical properties of PC.
文摘It is an established fact that huge quantities of water are lost from lakes, reservoirs and soils by evaporation. This assumes greater significance in arid and semi-arid regions around the globe when a general scarcity of water is compounded by high evaporation loss from the open water surfaces of lakes and reservoirs. The use of surface covering by a monomolecular film to reduce evaporation loss from large open water surfaces offers the greatest promise among all currently available techniques. This is the only system that retains the water surface in a state that does not interfere with other uses of the body of water such as boating, navigation recreation, fish, and wildlife propagation. Various experiments and field trials worldwide have proven conclusively that the fatty alcohols and their emulsions effectively retard water evaporation and result in saving to the tune of about 20% to 50%. An experiment was carried out at the Aji Reservoir (India) using a mixture of Cetyl and Stearyl alcohol that confirmed 19.26% saving in evaporation loss. During this six-month trial, about 0.18 mcum of water was saved which otherwise might have evaporated.
