文物保护有机树脂溶液型加固剂应用过程中反迁原因的探讨

有机溶液型加固剂在使用中经常会出现反迁现象。通过对加固剂性质、被加固材料的性质及加固过程的讨论,指出由于溶剂快速挥发而造成的有机树脂在文物表面层积聚,形成了加固剂的反迁现象。通过选择使用挥发速度低的溶剂,设法减少加固剂浓度及减缓溶剂的挥发速度,可有效地抑制反迁现象。

试论三峡移民“反迁”问题及对策

浩大的三峡移民工程于2010年宣告完工,但却有许多人户口还在迁入地,人却返回家乡,这种移民"反迁"现象的出现,已经引起社会乃至全球的关注。三峡移民不只是在地理位移上的改变而算成功,乃是在于移民们的生活幸福满意程度,真正的和谐是彼此互相帮助而不是排斥或歧视,让移民们真正感受到尊重和有爱和归属感才能真正解决移民"反迁"。应该采取政府关怀与帮助、移民发展经济等措施解决反迁问题。

Optical properties and magnetic properties of antisite-disordered Ni_(1-x)Co_xCr_2O_4 spinels

From the UV?Vis absorption spectra,the FT-IR absorption spectra and the Raman spectra,it is deduced that Co ionsprimarily occupy the tetrahedral(A)site,with a minor number of them entering into the octahedral(B)site in the Ni1?xCoxCr2O4compounds.The origin of the position disorder of the Co ions is consistent with the similar ionic radii of the Co ion(0.65?)and theCr ion(0.62?)at B site.The FT-IR peak at about510cm?1shifts towards high frequency side with the increasing cobalt content.Itis resulted from the reduction of the cation?oxygen distance in the octahedron by the replacement of the Ni2+with the Co2+ions.Themagnetic measurement shows that Curie temperatures(TC)are75and90K for the compounds with x=0.2and0.8,respectively.

A novel group-based active service protocol for migrating workflows

Based on the methods of acquaintance cache and group-based intelligent forwarding of service recommendations,a novel group-based active service(GAS) protocol for migrating workflows was proposed.This protocol did not require service requesters to discover services or resources.The semantic acquaintance knowledge representation was exploited to describe service groups and this semantic information was used to recommend service to respective clients.The experimental results show that the new protocol proposed offers better performance than other protocols in terms of first-response-time,success-scope and ratio of success-packet-number to total-packet-number.When the number of service request packet is 20,the first-response-time of GAS protocol is only 5.1 s,which is significantly lower than that of other protocols.The success-scope of GAS protocol is 49.1%,showing that GAS protocol can effectively improve the reliability of mobile transactions.And the ratio of success-packet-number to total-packet-number of GAS protocol is up to 0.080,which is obviously higher than that of other protocols.

Copper-catalyzed tandem radical amination/1,2-carbon migration of allylic alcohols: Direct access to α-quaternary-β-amino ketones

A novel nitrogen‐centered radical‐induced1,2‐carbon migration reaction of allylic alcohols has been developed.This method provides easy access to a variety ofα‐quaternary‐β‐amino ketones under mild reaction conditions.The reaction has a wide substrate scope and operational simplicity.Mechanistic studies suggest that1,2‐carbon migration is induced by regioselective nitrogen‐centered radical addition to the alkene unit.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Decreased prolactin-inducible protein expression exhibits inhibitory effects on the metastatic potency of breast cancer cells

Objective:The aim of the research was to study the effects of prolactin-inducible protein(PIP) downregulation on metastatic abilities of human breast cancer MDA-MB-453 cells.Methods:PIP-siRNA was transfected into human breast cancer MDA-MB-453 cells through liposome.Reverse transcription PCR and immunocytochemistry were employed to detect the downregulated expression of PIP.Cell migration,adhesion and invasion assays were performed to assess the impacts of PIP downregulation on cell migration,adhesion and invasion respectively.Results:Knockdown of PIP obviously inhibited cell migration,the migrated cells were decreased by 83.1% compared with the negative control group.Cell adhesion was also reduced,the adhesion rates at 30 min and 60 min were decreased by 42.6% and 48.5% respectively compared with the negative control group.Moreover,PIP downregulation resulted in decreased invasion rate by 73.9%.Conclusion:Reduced PIP expression in MDA-MB-453 cells can inhibit the abilities of migration,adhesion and invasion,which suggests that PIP plays an important role in the metastatic potency of breast cancer cells.

Prevalence and risk factors of gastroesophageal reflux disease in Qashqai migrating nomads, southern Iran

AIM： To investigate the prevalence and risk factors of gastroesophageal reflux disease （GERD） symptoms in Qashqai migrating nomads with a different life style in Fars province, southern Iran. METHODS： In summer 2006, 748 Qashqai migrating nomads aged 25 years or more were enrolled using a multiple-stage stratified cluster random sampling method. A questionnaire consisting of demographic characteristics, lifestyle and GERD symptoms （heartburn, regurgitation, chest pain, dysphagia, hoarseness and cough） as completed for each subject. RESULTS： The questionnaire was completed in 717 subjects. The prevalence rate of GERD, defined as reflux occurring at least one time per week in the preceding year, was 33% （237 subjects）. The prevalence was higher in older individuals （36.0% vs 28.9%, P 〈 0.05） and in those with other gastrointestinal complaints （51.0% vs 27.8%, P 〈 0.001）, but not different in obese and non-obese subjects. It was also higher in those consuming fruits and vegetables more than once a week （36.2% vs 17.3%, P 〈 0.001）. GERD had a positive correlation with smoking （42.1% vs 27.8%, P 〈 0.001）, but a negative relation with non-alcoholic beverages. The association between GERD and non-steroidal antiinflammatory drugs （NSAIDs） consumption was also significant （40.2% vs 25.4%, P 〈 0.001）. CONCLUSION： The prevalence of GERD （33%） is very high in Qashqai migrating nomads which may be due to a lower socioeconomic and educational level of these people and difference in the life style. Older age, frequent consumption of fruits and vegetables, smoking and NSAIDs are risk factors for GERD in this population.

Arctic spring: the arrival biology of migrant birds

On arrival in the Arctic, migrant birds must adjust their physiology and behavior to unpredictable snow cover, weather, food sources and predator pressure. In other words they must be resistant to environmental perturbations (stress) so that they can migrate to their tundra nesting areas and settle on territories as soon as possible. They can then begin breeding as soon as when environmental conditions become favorable. They do this partly by using micro-habitats such as areas where snow depth is low, and patches of tundra that melt out rapidly (especially near willows Salix sp). Ground temperatures increase dramatically within hours after exposure to sun; and invertebrate activity begins simultaneously. Wind speeds are attenuated almost completely within 10 cm of the ground in willows and tussock tundra. The combination of these conditions provides an ideal refuge, especially for passerine migrants in early spring. However, if conditions worsen, the birds can leave. There are adjustments of the adrenocortical responses to stress because arctic conditions in spring are potentially severe, at least compared with wintering grounds to the south. Secretion of corticosterone in response to acute stress is enhanced at arrival in males, accompanied by a decrease in sensitivity to negative feedback and a change in responsiveness of the adrenal cortex cells to adrenocorticotropin. There is also an increase in levels of corticosterone-binding globulin (CBG) so that the actions of corticosterone are buffered according to the severity of environmental conditions. Regulation at the level of genomic receptors, particularly the low affinity glucocorticosteroid-like receptor for corticosterone in brain and liver, may be important; and non-genomic actions of corticosterone may play a major role too. In other words, the hormone-behavior system associated with arrival biology is highly flexible.

近年台湾“土地正义”运动的特征及困境

近年台湾“土地正义”运动在社运团体和民进党的双重外力介入之下,促使土地征收事务迅速从地方事件上升为全区域议题、从利益博弈转变为观念抗争、从常规治理异化为党派攻讦,但数年的运动并未推进“地尽其利”和“地利共享”,且出现多方共损的负和博弈态势:少数反对户诉求被置换、多数同意户诉求被忽略、社运团体独立性和公信度受质疑、民进党由于街头政治惯性和政治酬庸导致治理低效选情低迷。“土地正义”运动的困境,揭示了蔡英文和民进党操弄社会运动的本质和后果:只有政治斗争手腕,没有治理实务能力。

Activated focal adhesion kinase involved in adhesion and migration of vascular smooth muscle cells stimulated by fibronectin

OBJECTIVE: To study the effects of focal adhesion kinase (FAK) phosphorylation on smooth muscle cells (SMCs) adhesion and migration stimulated by fibronectin. METHODS: Adhesion and migration of cultured SMCs were stimulated by different concentrations of fibronectin (FN), FAK and its phosphorylation were detected by immunoprecipitation and Western blot. FAK antisense oligodeoxynucleotides (ODNs) were transfected into SMCs by cationic lipid to investigate its modulatory effects on tyrosine phosphorylation. SMCs adhesion and migration were also measured by morphological enumeration and modified Boyden Chambers, respectively. RESULTS: FAK were expressed when SMCs adhesion and migration were successfully simulated by different concentrations of FN. FAK phosphorylation were detected only at 20 microg/ml FN or more. FAK antisense ODNs were transfected efficiently by cationic lipid and FAK phosphorylation was inhibited substantially. The SMCs migration rate in the 5 - 60 microg/ml FN groups was reduced by 17.89% - 27.67%. Cell migration stimulated by FN at 10, 20, 40 and 60 microg/ml were reduced by 23.26%, 21.63%, 19.31% and 17.88%, respectively (P

Activated focal adhesion kinase involved in adhesion and migration of vas cular smooth muscle cells stimulated by fibronectin

To study the effects of focal adhesion kinase (FAK) phosphorylation on smooth mu scle cells (SMCs) adhesion and migration stimulated by fibronectin Methods Adhesion and migration of cultured SMCs were stimulated by different concentrati ons of fibronectin (FN), FAK and its phosphorylation were detected by immunoprec ipitation and Western blot FAK antisense oligodeoxynucleotides (ODNs) were tra nsfected into SMCs by cationic lipid to investigate its modulatory effects on ty rosine phosphorylation SMCs adhesion and migration were also measured by morph ological enumeration and modified Boyden Chambers, respectively Results FAK were expressed when SMCs adhesion and migration were successfully simulated by different concentrations of FN FAK phosphorylation were detected only at 20 ?μg/ml FN or more FAK antisense ODNs were transfected efficiently by cationi c lipid and FAK phosphorylation was inhibited substantially The SMCs migration rate in the 5-60?μg/ml FN groups was reduced by 17 89%-27 67% Cell migrat ion stimulated by FN at 10, 20, 40 and 60?μg/ml were reduced by 23 26%, 21 6 3%, 19 31% and 17 88%, respectively ( P 【0 05) Conclusions FAK phosphorylation and FAK mediated signal transduction play important roles i n SMCs adhesion and migration stimulated by ECM The process can be inhibited e ffectively by FAK antisense ODNs

Migration of multiples from the South China Sea

The South China Sea where water depth is up to 5000 m is the most promising oil and gas exploration area in China in the future.The seismic data acquired in the South China Sea contain various types of multiples that need to be removed before imaging can be developed.However,compared with the conventional reflection migration,multiples carry more information of the underground structure that helps provide better subsurface imaging.This paper presents a method to modify the conventional reverse time migration so that multiple reflections can migrate to their correct locations in the subsurface.This approach replaces the numerical impulsive source with the recorded data including primaries and multiples on the surface,and replaces the recorded primary reflection data with multiples.In the reverse time migration process,multiples recorded on the surface are extrapolated backward in time to each depth level,while primaries and multiples recorded on the surface are extrapolated forward in time to the same depth levels.By matching the difference between the primary and multiple images using an objective function,this algorithm improves the primary resultant image.Synthetic tests on Sigsbee2 B show that the proposed method can obtain a greater range and better underground illumination.Images of deep water in the South China Sea are obtained using multiples and their matching with primaries.They demonstrate that multiples can make up for the reflection illumination and the migration of multiples is an important research direction in the future.

Behavioral conditions： and life history responses to extreme climatic Studies on a migratory songbird

Behavioral responses to environmental change are the mechanisms that allow for rapid phenotypic change preventing temporary or permanent damage and hence preventing reductions in fitness. Extreme climatic events are by definition rare, although they are predicted to increase in amplitude and frequency in the coming years. However, our current knowledge about behavioral responses to such extreme events is scarce. Here I analyze two examples of the effects of extreme weather events on behavior and life history： （1） A comparison of behavior and life history during extremely warm and extremely cold years relative to normal years; and （2） a comparison of behavior before and after the extremely early snowfall in fall 1974 when numerous birds died in the Alps during September-October. Behavioral and life history responses of barn swallows Hirundo rustica to extremely cold and extremely warm years were positively correlated, with particularly large effect sizes in cold years. Extreme mortality in barn swallows during fall migration 1974 in the Alps eliminated more than 40% of the breeding population across large areas in Central and Northern Europe, and this affected first arrival date, changes in timing and extent of reproduction and changes in degree of breeding sociality supposedly as a consequence of correlated responses to selection. Finally, I provide directions for research that will allow us to better understand behavior and life history changes in response to extreme climate change [Current Zoology 57 （3）： 351-362, 2011].

Gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via an unexpected 1,2-alkyl migration

A gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via the presumable α-imino gold carbenes has been developed, providing an alternative and efficient way for the synthesis of valuable 3-amino-β-carbolines in generally good to excellent yields. Importantly, this new protocol involves an unexpected 1,2-alkyl migration pathway.

5 nm NiCoP nanoparticles coupled with g-C3N4 as high-performance photocatalyst for hydrogen evolution

Graphitic carbon nitride(g-C3N4) coupled with NiCoP nanoparticles with sizes around 5 nm have been fabricated via a controllable alcohothermal process. NiCoP is an excellent electron conductor and cocatalyst in photocatalytic reactions. The coupling between tiny NiCoP nanoparticles and g-C3N4 through in-situ fabrication strategy could be a promising way to eliminate the light screening effect, hinder the recombination of photo-induced charge carriers, and improve the charge transfer. The NiCoP/g-C3N4 nanohybrids exhibit an excellent photocatalytic activity in the hydrogen generation, with a significantly improved performance compared with original g-C3N4, CoP/g-C3N4 and Ni2P/g-C3N4, respectively. This study paves a new way to design transition metal phosphides-based photocatalysts for hydrogen production.

Esculin alleviates acute kidney injury and inflammation induced by LPS in mice and its possible mechanism

Acute kidney injury(AKI)is a common clinical serious illness.Esculin(ES)is a coumarin compound of traditional Chinese medicine Cortex Fraxini.Our previous study has found that ES protects against inflammation and renal damage in diabetic rats.In the present study,we aimed to investigate the effects and the possible mechanism of ES against lipopolysaccharides(LPS)-induced AKI in mice.Renal morphology was observed by H&E staining.Renal function was evaluated by blood urea nitrogen(BUN)level and creatinine content in serum.Inflammatory factor levels were measured by ELISA assay.The inflammatory proteins were analyzed by RT-PCR and Western blotting analysis.The results showed that ES alleviated LPS-induced pathological injury and renal dysfunction,and decreased BUN level and creatinine content in serum.In addition,ES significantly reduced the release of pro-inflammatory factors,including IL-1β,IL-6 and TNF-α,chemokine MCP-1 and cell adhesion molecule ICAM-1.Furthermore,the expressions of inflammatory pathway proteins P2 X7,HMGB1,TLR4 and MyD88 both at the mRNA and protein levels were all down-regulated by ES in the kidney tissue of LPS-challenged mice.These results suggested ES protected against LPS-induced AKI through inhibiting P2 X7 expression and HMGB1/TLR4 inflammatory pathway.

ROLE OF DISEASE PROPAGATION IN MIGRATORY BIRD POPULATION

Chatterjee considered a predator prey model with avian migration in the migration prey population IS. Chatterjee, Alternative prey source coupled with prey recovery enhance stability between migratory prey and their predator in the presence of disease, Nonlinear Anal. Real World Appl. 11 （2010） 4415-4430]. In this paper, we modify and analyze the model by taking time dependent parameters and the general flmctional response into consideration. The conditions for the persistence of the system and the extinction of the disease are obtained. The global attractivity of the system is also studied. By numerical simulations, we find that the qualitative behavior of the system independent on the choice of the functional response. Moreover, it is observed that the infection rate, recruitment rate and the predation rate play a vital role in predicting the behavior of the dynamics.