Simultaneous determination of typical toxic aldehydes formed during food frying and digestion using isotope dilution UHPLC-QqQ-MS/MS

An isotope dilution ultra-performance liquid chromatography-triple quadrupole mass spectrometry method was developed to simultaneously detect two typical kinds ofα,β-unsaturated aldehydes,namely 4-hydroxy-2-hexenal(4-HHE)and 4-hydroxy-2-nonenal(4-HNE),in foods.The proposed method exhibited a linear range of 10-1000 ng/mL with a limit of detection of 0.1-2.0 ng/g and a limit of quantification of 0.3-5.0 ng/g.The recovery rates of these typical toxic aldehydes(i.e.,4-HHE,4-HNE)and their d3-labeled analogues were 91.54%-105.12%with a low matrix effect.Furthermore,this proposed method was successfully applied to a real frying system and a simulated digestion system,wherein the contents of 4-HHE and 4-HNE were determined for both.Overall,the obtained results provide strong support for further research into the production of 4-HHE and 4-HNE resulting from foods during oil digestion and frying.

烷基膦酸键合的纳米氧化物上甲苯选择氧化制苯甲醛的类酶机理

在传统催化反应中,分子氧催化氧化烷烃生成目标产物的选择性最低,常产生副产物以及大量的COx和水,因需要复杂的分离过程而导致流程的投资成本高.因此,在过去几十年里,针对此类反应的研究以提高选择性为首要目标,但克服这一挑战的任务依然艰巨.在此类反应中,甲苯经O_(2)选择性催化氧化是制备苯甲醛的最佳途径,但从未实现工业化,其中的主要难点在于苯甲醛在临氧条件下的继续氧化反应速率比甲苯氧化高4个数量级以上.因此,在高甲苯转化率下高选择性获得苯甲醛是绿色化学研究中一个极具挑战性的课题.本文发现一种甲苯/水的类皮克林乳液催化体系对甲苯转化为苯甲醛有很高的活性和选择性,其中两性纳米颗粒(十六烷基膦酸,简写为HDPA,键合的纳米铁基氧化物)作为催化剂并处在乳液相界面处.在温和条件下通过O_(2)氧化,苯甲醛的时空产率大于2 g·g^(-1)·h^(-1),整个过程没有使用H_(2)O_(2)、卤素或其它自由基引发剂.实验发现,用于甲苯氧化反应的相关催化剂HDPA-FeMOx/γ-Al_(2)O_(3)(M:V和Mo等)的作用机制类似甲烷单加氧酶.在传统固定床反应器中和温和的条件下(70~160°C,常压),催化剂能将甲苯单一氧化为苯甲醛.催化剂的活性中心与HDPA以单齿态与氧化物表面键合有关,并且它的另一个磷羟基与氧化物表面在非键合态和键合态之间循环变化,分别对应甲苯反应中催化剂的氧化态和还原态,即HDPA与氧化物表面通过单齿和双齿键合循环变化,极大地提升了该铁基复合氧化物晶格氧的移动性而使得催化剂反应活性得到明显提升.透射电子显微镜、X射线衍射和氮吸附测量结果表明,铁基复合金属氧化物在γ-Al_(2)O_(3)纳米棒上具有良好的分散性和较大的比表面积.X射线光电子能谱、吡啶吸附FT-IR和31P NMR结果表明,与表面键合的HDPA保留了有机膦酸属性,没有与FeMOx/γ-Al_(2)O_(3)生成体相磷酸盐,其中,以单齿状态与表面键合HDPA分子只占总数的2%左右.H_(2)-TPR和CO-TPR结果表明,HDPA的键合强烈影响了晶格氧的流动性或金属氧化物的活性.反应条件下原位FT-IR结果表明,HDPA-FeVO_(x)/γ-Al_(2)O_(3)在70°C下即能催化甲苯氧化成苯甲醛,且不会过度氧化,该催化剂的晶格氧物种可参与甲苯转化为苯甲醛.此外,发现HDPA-Fe_(2)O_(3)/γ-Al_(2)O_(3)对甲苯的吸附具有特殊的分子识别作用,以苯甲醇氧化作为对照反应的研究结果也表明HDPA-Fe_(2)O_(3)/γ-Al_(2)O_(3)对甲苯氧化为苯甲醛的反应存特异催化作用.宏观反应动力学测试结果表明,催化剂上苯甲醛生成的表观活化能仅为~44.5 kJ/mol.在低H_(2)O浓度下,甲苯氧化速率对甲苯浓度为一级反应,对O_(2)浓度为零级反应,基元反应步骤推导出来的动力学方程与实验结果良好吻合,说明了该催化剂上类酶反应基元步骤假设的合理性。

Effect of erhuangfang on cerebral and spinal demyelination and regeneration as well as expression of glial fibrillary acidic protein in rats with experimental allergic encephalomyelitis

BACKGROUND： It demonstrates that erhuangfang can improve clinical symptoms of multiple sclerosis and relieve side effects of hormone. However, whether erhuangfang can improve experimental allergic encephalomyelitis （EAE） or not needs a further study. OBJECTIVE： To observe the effect of erhuangfang on neuro-pathology and astrocyte in EAE rats and compare with the effect of hormone. DESIGN： Randomized controlled animal study. SETTINGS： Department of Traditional Chinese Medicine, Beijing Tiantan Hospital, Capital Medical University; College of Traditional Chinese Medicine, Capital Medical University. MATERIALS： The experiment was carded out in the Laboratory Center of Capital Medical University from August to October 2005. Ten adult guinea pigs （SPF grade, weighing 400 - 450 g） and 70 adult Lewis rats （SPF grade, weighing 200- 220 g） were selected in this study. Erhuangfang consisted of fiudahuang, shengdi, shuizhi, dabeimu, etc. METHODS： ①Experimental intervention： Rats were randomly divided into normal group （n=10）, model group （n=20）, western medicine group （n=20） and Chinese herb group （n=20）. Mixed emulsion, which was consisted of Freund＇s adjuvant and spinal cord homogenate of guinea pigs, was subcutaneously injected into palms of the two hindfeet of rats in the latter three groups to establish EAE models. Foot pads were injected with saline and then rats were perfused with saline in the normal group.in the model group, models were established as the same as those mentioned above, and rats were also perfused with saline. Rats in the western medicine group were perfused with saline and then 5 mg/kg prednisone acetate suspension. Rats in the Chinese herb group were perfused with erhuangfang decoction （15 g raw materials per kilogram） at 5 days before model establishment. The dosage in the four groups was 3 mL/day per rat. ②Experimental evaluation： At 28 days after model establishment, rats were randomly selected for cerebral （mainly surrounding cerebral ventricle） and spinal cord （cervical enlargement and lumbar enlargement） collections, and then haematine-eosin （HE） staining and SLG myelin staining were used to observe demyelination and regeneration; meanwhile, immunohistochemical staining was used to observe the expression of glial fibriliary acidic protein （GFAP）. MAIN OUTCOME MEASURES： Cerebral and spinal demyelination and regeneration as well as expression of GFAP in EAE rats. RESULTS： All 70 Lewis rats were involved in the final analysis. ①Demyelination and regeneration： Infiltration of inflammatory cells surrounding cerebrum and small venous vessels of spinal cord white matter, demyelination surrounding vessels and plentiful foam cells at myelinolysis sites were observed in the model group. Symptoms were relieved in the western medicine group and the Chinese herb group as compared with those in the model group. While, numbers of inflammatory infiltrated cells and vascular cuffs were decreased in focal region as compared with those in the model group; in addition, areas of softening focus and demyelination were decreased. ②Expression of GFAP： Volumes and numbers of positive cells of GFAP in white matter region were respectively bigger and higher than those of normal cells in the model group. Plentiful positive cells of GFAP were disorderly aggregated in hippocampus and surrounding small vessel cuffs. While, expression of GFAP was mildly increased surrounding focus in the Chinese herb group; however, GFAP did not express surrounding focus in the western medicine group. In addition, expressions of GFAP were not increased in non-focal region in both Chinese herb group and western medicine group. CONCLUSION： Both erhuangfang and hormone can relieve inflammatory reaction of central nervoussystem and demyelination of EAE rats. On one hand, erhuangfang can regulate reaction of astrocyte in two ways, relieve reaction and proliferation of astrocyte in non-focal region and maintain the protective effect of astrocyte on brain tissue in focal region; on the other hand, hormone can overall inhibit reaction of astrocyte.

Transient thermo-mechanical analysis for bimorph soft robot based on thermally responsive liquid crystal elastomers

Thermally responsive liquid crystal elastomers (LCEs) hold great promise in applications of soft robots and actuators because of the induced size and shape change with temperature. Experiments have successfully demonstrated that the LCE based bimorphs can be effective soft robots once integrated with soft sensors and thermal actuators. Here, we present an analytical transient thermo-mechanical model for a bimorph structure based soft robot, which consists of a strip of LCE and a thermal inert polymer actuated by an ultra-thin stretchable open-mesh shaped heater to mimic the unique locomotion behaviors of an inchworm. The coupled mechanical and thermal analysis based on the thermo-mechanical theory is carried out to underpin the transient bending behavior, and a systematic understanding is therefore achieved. The key analytical results reveal that the thickness and the modulus ratio of the LCE and the inert polymer layer dominate the transient bending deformation. The analytical results will not only render fundamental understanding of the actuation of bimorph structures, but also facilitate the rational design of soft robotics.

绿色建筑工程造价预算与成本控制对策的研究

我国经济发展水平不断提升,人们生活水平不断攀升,但传统建筑工程发展所带来的环境污染问题也正在日益加重,能源消耗量持续增加。现如今,人们对于生活环境质量要求更高,建筑行业必须坚持走可持续发展道路,而绿色建筑正是这一背景下提出的建筑发展概念。本文首先对绿色建筑进行简单概述,然后对绿色建筑工程造价预算进行相关探讨,最后提出绿色建筑工程成本控制措施,望采纳。

Long-term application of diethylstilbestrol upregulates expressions of μ-and m-calpains in pituitary intermediate lobe of female Wistar rats

BACKGROUND： During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release prolactin （PRL） and may promote formation of prolactin neoplasia in pituitary anterior lobe. OBJECTIVE： To observe the effect of diethylstilbestrol （DES） on the expressions of μ and m-calpains in pituitary intermediate lobe of female Wistar rats. DESIGN： Observational contrast animal study. SETTING： Beijing Neurosurgical Institute. MATERIALS： A total of 21 female Wistar rats, 3 weeks old weighing 70-80 g were housed with free access to tap water and standard pellet food. They were kept in a CL-grade condition, at （24±1）℃ and a humidity of （55±5）%, and with a 12 hours day-night cycle. Caprine anti-μ- and m-calpains antibodies were provided by Santa Cruz Biotechnology, CA, USA; rabbit-anti-PRL antibodies by Dako, Denmark; rabbit-anti-ACTH antibody by Boster Company, Wuhan. METHODS： The experiment was carried out in Pathophysiological Department and Animal Laboratory, Beijing Neurosurgical Institute from August 2006 to January 2007. ① Rats were randomly divided into groups with 7 in each group, including vehicle control group, in which rats were injected intraperitoneally with sun-flower seed oil （1 mL/kg, twice a week） for 16 weeks; DES group, where animals were administered with DES （5 mg/kg, twice a week） for 16 weeks; DES ＋ vehicle control group, in which DES was administered for 12 weeks at the same dose with those in DES group, and then was discontinued and replaced by sun-flower seed oil （1 mL/kg, twice a week） for the following 4 weeks. ② At 16 weeks later, pituitary tissue was dealt with HE staining and PRL immunohistochemical examination to observe evoke of tumor; meanwhile, immunohistochemical examination was used to observe expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. MAIN OUTCOME MEASURES： ① Expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. ② Morphological observation of pituitary tissue. RESULTS： All 21 rats were involved in the final analysis. ① Results of immunohistochemical examination： Morphological changes of neoplasia in DES group were strongly positive to PRL, and this suggested that formation of prolactin adenoma was observed in pituitary tissue. As compared with vehicle control group, expression of adrenoeorticotropic hormone （ACTH） was increased in both DES group and DES ＋ vehicle control group. In addition, expressions of μ- and m-calpains in pituitary intermediate lobe were higher in DES group than that in vehicle control group. Otherwise, expressions of m-calpains in pituitary intermediate lobe was decreased in DES ＋ vehicle control group, but expression of μ-calpains was still increased. ② Morphological observation of pituitary tissue： Gland tubes were orderly arranged in rats in vehicle control group. Anterior pituitary gland in rats of DES group demonstrated an apparent disappearance of gland tubes and a relatively large-scaled vasculature formation, namely the vascular lake lined by tightly arranged endothelial cells. Local integrated tumor cell arrangements were also detected. In addition, the border between the IL and the anterior lobe was locally blurred. The definite tumor-like changes in pituitary tissueswere confirmed in 6 of 7 female Wistar rats in DES group, and one spontaneous occurrence of tumor formation was found in vehicle control group. In DES ＋ vehicle control group, DES withdrawal led to the subtile emergence of gland tube cavity, although tumor-like cells still existed in 4 of 7 rats, suggesting occurrence of the tumor regression due to the withdrawal of DES. CONCLUSION： A long-term application of DES can enhance the expressions of ubiquitours neutral cysteine protease in pituitary intermediate lobe and this suggests that both of them play a key role in release of hormone and formation of prolactin neoplasia through directly promoting PRL expression and release of neighboring pituitary intermediate lobe.

Deformation mechanisms and differential work hardening behavior of AZ31 magnesium alloy during biaxial deformation

Magnesium alloys are frequently subjected to biaxial stress during manufacturing process,however,the work hardening behavior under such circumstance are not well understood.In this study,the deformation mechanisms and differential work hardening behavior of rolled AZ31 magnesium alloy sheets under biaxial loading are investigated.The change of plastic work contours with increasing plastic strain indicates the differential work hardening behavior of AZ31 magnesium alloy under biaxial stress state,resulting in higher macroscopic work hardening rates of biaxial loading than uniaxial loading,with the elastic-plastic transition part of work hardening extended and stage Ⅲ hardly emerged.Electron backscatter diffraction and Schmid factor analysis confirm the low activation of non-basalslip during biaxial loading tests.While the thickness strain is primarily accommodated by pyramidal<c+a>slip at the initial stage of biaxial deformation,{10–11}contraction twinning is activated at larger plastic strain.The low activation of non-basalslip also retards the dynamic recovery and cross-slip of basal and prismaticslips,leading to the differential work hardening behavior of AZ31 magnesium alloy under biaxial stress state.

Berberine might block colorectal carcinogenesis by inhibiting the regulation of B-cell function by Veillonella parvula

Background:Colorectal carcinogenesis and progression are related to the gut microbiota and the tumor immune microenvironment.Our previous clinical trial demonstrated that berberine(BBR)hydrochloride might reduce the recurrence and canceration of colorectal adenoma(CRA).The present study aimed to further explore the mechanism of BBR in preventing colorectal cancer(CRC).Methods:We performed metagenomics sequencing on fecal specimens obtained from the BBR intervention trial,and the differential bacteria before and after medication were validated using quantitative polymerase chain reaction.We further performed Apc Min/+animal intervention tests,RNA sequencing,flow cytometry,immunohistochemistry,and enzyme-linked immunosorbent assays.Results:The abundance of fecal Veillonella parvula(V.parvula)decreased significantly after BBR administration(P=0.0016)and increased through the development from CRA to CRC.Patients with CRC with a higher V.parvula abundance had worse tumor staging and a higher lymph node metastasis rate.The intestinal immune pathway of Immunoglobulin A production was activated,and the expression of TNFSF13B(Tumor necrosis factor superfamily 13b,encoding B lymphocyte stimulator[BLyS]),the representative gene of this pathway,and the genes encoding its receptors(interleukin-10 and transforming growth factor beta)were significantly upregulated.Animal experiments revealed that V.parvula promoted colorectal carcinogenesis and increased BLyS levels,while BBR reversed this effect.Conclusion:BBR might inhibit V.parvula and further weaken the immunomodulatory effect of B cells induced by V.parvula,thereby blocking the development of colorectal tumors.Trial Registraion:ClinicalTrials.gov,No.NCT02226185.

Clinical evaluations of mineralized collagen in the extraction sites preservation

The purpose of this study was to explore the different effects between biomimetic mineralized collagen(MC)and ordinary physically blended hydroxyapatite/collagen(HA/Col)composite in evaluating new bone formation and regenerated bone height in human extraction sockets.Thirty-four patients who cannot retain teeth caused by trauma or decay were randomly selected from Department of Stomatology of Dongzhimen Hospital from December 2013 to December 2014.The patients were randomly divided into two groups.After the operation of tooth extraction,17 patients were implanted with biomimetic MC(MC group),and other 17 patients were implanted with ordinary physically blended nHA/Col composite(nHA/Col group).X-ray positioning projection by auto-photographing was taken to test the distance between the lowest position and the neighboring CEJm-CEJd immediately,1 month and 3 months after the operation.The height of new bone formation of the MC group was significantly higher than the nHA/Col group.Biomimetic MC showed better clinical outcomes in the bone formation for extraction site preservation and would have broad application prospect in the field of oral and maxillofacial surgeries.

柔性微型无机发光二极管的瞬态传热分析

集成在柔性衬底上的微型无机发光二极管(microscale inorganic light-emitting diodes,μ-ILED)能够承受拉、弯、扭等载荷,可以实现与人体组织直接集成,可作为一种新型光学探测器应用于人体健康监测和临床医学诊断.但这种电子器件在工作时会发出大量的热,器件的传热特性成为应用的重要问题.本文采用分离变量方法针对具有轴对称形状柔性μ-ILED瞬态传热过程建立了理论和有限元仿真模型,得到了系统温升随时间和空间坐标的变化规律,理论预测结果得到了有限元仿真的验证.通过理论模型,讨论了μ-ILED与封装层/衬底材料面内尺寸之间比值对正常工作下柔性μ-ILED温升的影响关系,这些结果能够预测基于柔性μ-ILED的微小体征探测器的发热过程,对其热管理及相应的散热设计具有一定的指导意义.

Effect of Traditional Chinese Medicine on oligoasthenospermatism:a narrative review

OBJECTIVE: To summarize the treatment of oligoasthenospermatism(OAS) with Traditional Chinese Medicine(TCM).METHODS: The literature describing OAS treatment with TCM in the past 4 years was searched.Three studies were reviewed, evaluated, and summarized. The etiology and pathogenesis, pattern differentiation, medicine administration, and combination of TCM with Western Medicine were all examined.RESULTS: TCM had an advantage in treating OAS and had fewer adverse events than conventional treatments.CONCLUSION: Although TCM has an advantage in treating OAS and fewer adverse events, the efficacy of TCM and modern medicine on OAS is unsatisfactory.

Influence of annealing temperature on the performance of TiO_(2)/SiO_(2) nanolaminated films

Different laminated structures of TiO_(2)/SiO_(2) composite film were prepared via atomic layer deposition(ALD)on alumina substrates.The effect of the annealing temperature in the air on the surface morphologies,crystal structures,binding energies,and ingredient content of these films was investigated using X-ray diffraction,field emission scanning electron microscopy,and X-ray photoelectron spectroscopy.Results showed that the binding energy of Ti and Si increased with decrease of the Ti content,and the TiO_(2)/SiO_(2) nanolaminated films exhibited a complex bonding structure.As the annealing temperature increased,the thickness of the nanolaminated films decreased,and the density and surface roughness increased.An increase in the crystallization temperature was proportional to the SiO_(2) content in TiO_(2)/SiO_(2) composite film.The annealing temperature and thin thickness strongly affected the phase structure of the ALD TiO_(2) thin film.To be specific,the TiO_(2) thin film transformed into an anatase phase from an amorphous phase after an increase in the annealing temperature from 400℃ to 550℃,and the TiO_(2) film exhibited an anatase phase until the annealing temperature reached 850℃,owing to its extremely small thickness.The annealing process caused the Al ions in the substrate to diffuse into the films and bond with 0.

Deformation mechanism of commercially pure titanium under biaxial loading at ambient and elevated temperatures

Commercially pure(CP)titanium is thermally processed and subjected to biaxial stress.However,the evolution of the microstructural deformation mechanisms under such circumstances is not adequately understood.In this study,the mechanical responses and microstructural deformation mechanisms of TA2 CP titanium sheets under equi-biaxial loading at room temperature(RT),300℃,and 400℃were studied.The activated slip and twinning systems were investigated by transmission electron microscopy(TEM)after polished cruciform specimens were biaxially tensile-tested at RT and elevated temperatures.The results show that{11¯22}contraction twinning and{10¯12}extension twinning are the main deforma-tion mechanisms of RT biaxial deformation,while dislocation glide is predominant in biaxial deformation at 300℃and 400℃.This difference yields varied work-hardening behaviors at RT and elevated tem-peratures.In biaxial deformation at 400℃,the main slip trace type is multiple slip.The interaction of different slip systems in multiple slip created shear deformation concentration areas and further induced cross-slip.However,in biaxial deformation at 300℃,the amounts of simplex and multiple slip were significantly reduced compared to those at 400℃because the lower temperature increased the critical resolved shear stress and insufficient activated slip systems were available for grain deformation.There-fore,several stress-concentration areas were generated with the activation of cross-slip.

Clinical Manifestations and Amplitude-integrated Encephalogram in Neonates with Early-onset Epileptic Encephalopathy

Background： The patients with early-onset epileptic encephalopathy （EOEE） suffer from neurodevelopmental delay. The aim of this study was to analyze the clinical manifestations and amplitude-integrated encephalogram （aEEG） characteristics of infants with EOEE with onset within the neonatal period, to make early diagnosis to improve the prognosis. Methods： One-hundred and twenty-eight patients with neonatal seizure were enrolled and followed up till 1 year old. Sixty-six neonates evolved into EOEE were as the EOEE group, the other 62 were as the non-EOEE （nEOEE） group. Then we compared the clinical and aEEG characteristics between the two groups to analyze the manifestations in neonates with EOEE. Results： Compared to the nEOEE group, the incidence of daily seizure attacks, more than two types of convulsions, more than two antiepileptic drugs （AEDs） application, severely abnormal aEEG background, absence of cyclicity, and more than two seizures detection were significantly higher in the EOEE group （P 〈 0.05） （97% vs. 54.8%; 30.3% vs. 14.5%; 97.0% vs. 25.4%; 39.4% vs. 3.2%; 57.6% vs. 9.7%; and 56% vs. 3.2%, respectively）. Severely abnormal background pattern （odds ratio [OR] = 0.081, 95% confidence interval [CI]：0.009-0.729, P = 0.025） and more than two seizures detection by aEEG （OR = 0.158, 95% CI： 0.043-0.576, P = 0.005） were the independent risk factors for the evolvement into EOEE. The upper and lower margins of active sleep （AS） and quiet sleep （QS） were significantly higher in EOEE group than those of the control group （P 〈 0.05） （34.3 ± 13.6 vs. 21.3 ± 6.4; 9.9 ± 3.7 vs. 6.7 ± 2.2; 41.2 ± 15.1 vs. 30.4 ± 11.4;and 11.9 ± 4.4 vs. 9.4 ± 4.0; unit： μV, respectively）. AS upper margin was demonstrated a higher diagnostic specificity and sensitivity for EOEE than another three parameters according to the receiver operating characteristic curves; the area under the curve was 0.827. Conclusions： The clinical characteristics of the neonatal seizure which will evolve into EOEE were more than two AEDs application, high seizure frequency （daily attack）, and more than two types of the seizure. Significant high voltage, severely abnormal background, absence of cyclicity, and more than two seizures detected on aEEG were the meaningful indicators to the prediction of EOEE.