再生丝素膜的β化作用

本文研究了初生丝素膜的β化方法.经过对丝素的红外光谱、x—射线衍射、水不溶率的研究,发现汽蒸处理是丝素膜较理想的β化方法,只要汽蒸1分钟。

敷和备化方对肝癌干细胞Wnt/β-catenin通路的影响

目的探讨敷和备化方对CD+133HepG2肝癌干细胞Wnt/β-catenin通路的影响。方法通过免疫磁珠法分筛出CD+133HepG2肝癌干细胞后,在干细胞培养液中诱导和培养,流式细胞术鉴定CD+133HepG2细胞比例,将CD+133HepG2肝癌干细胞分为血清对照组、空白对照组、XVV939阳性药对照组、敷和备化方组。血清对照组加入体积分数为16%正常大鼠血清培养基,空白对照组加入相同剂量正常培养基,阳性对照组加入相同剂量含1μmol/L XVV939的培养基,敷和备化方组加入体积分数为16%敷和备化方含药血清培养基,药物作用6 d后采用RT-PCR以及Western blot检测Wnt/β-catenin通路相关因子Wnt1、β-catenin、PI3K、AKT的mRNA以及蛋白表达。结果与空白对照组和血清对照组相比,阳性药对照组和敷和备化方组皆可下调Wnt1、β-catenin、PI3K、Akt的mRNA水平(P<0.05),其中阳性药对照组对Wnt1、Akt的抑制力最强,敷和备化方组对β-catenin的抑制力最强;与空白对照组和血清对照组相比,阳性药对照组和敷和备化方组皆可下调Wnt1、PI3K、Akt的蛋白水平(P<0.05),敷和备化方组能明显下调β-catenin的蛋白水平(P<0.05)。结论相较于PI3K/Akt通路,敷和备化方可以更有效下调Wnt/β-catenin通路相关因子的mRNA和蛋白表达水平,从而降低肝癌干细胞的胚系干性水平。

补肾益气活血化痰方治疗老年全身麻醉后认知障碍及对血清E2、T、Aβ、BNP的影响

目的研究补肾益气活血化痰方治疗老年全身麻醉后认知障碍及对患者血清雌二醇(E2)、睾酮(T)、Tβ-淀粉样蛋白(Aβ)、脑钠肽(BNP)的影响。方法选择医院2017年10月—2018年9月诊治的老年全身麻醉后认知障碍96例作为研究对象,遵照知情同意原则并按照随机数字表法分为两组,每组48例。对照组采用常规西医治疗,观察组在常规西医治疗基础上采用补肾益气活血化痰方治疗。比较两组患者的治疗效果,简易精神状态量表(MMSE)与蒙特利尔认知评估量表(MoCA),患者血清E2、T、Aβ、BNP水平以及不良反应发生情况。结果观察组总有效率显著高于对照组,组间差异有统计学意义(P<0.05)。治疗前两组患者的MMSE、MoCA评分差异无统计学意义(P>0.05),两组治疗后1周、2周MMSE、MoCA评分均有改善,治疗后1周两组间MMSE、MoCA评分差异无统计学意义(P>0.05),治疗后2周观察组MMSE、MoCA评分显著优于对照组(P<0.05)。治疗前两组患者的血清E2、T、Aβ、BNP差异无统计学意义(P>0.05),治疗后1周、2周两组患者的血清E2、T、Aβ、BNP均有改善,但治疗后1周两组间各指标差异无统计学意义(P>0.05),治疗后2周观察组的血清E2、T显著高于对照组,血清Aβ、BNP显著低于对照组,组间差异有统计学意义(P<0.05)。观察组不良反应发生率为12.5%(6/48),对照组为10.4%(5/48),组间无显著性差异(P>0.05)。结论补肾益气活血化痰方治疗老年全身麻醉后认知障碍可获得满意的临床效果,能够降低患者的血清Aβ、BNP水平、升高血清E2、T水平,改善患者的认知功能,是有效安全的治疗方案。

Effect of Fe and Mo additions on microstructure and mechanical properties of TiAl intermetallics

The ductility of TiAl intermetallics can be improved through stabilizing the ductile β phase.New β-stabilized Ti-45Al-xFe-yMo（x,y=1,2,3,4） alloys were designed through adding the β stabilizing elements Fe and Mo.The microstructural evolution and deformation behavior of the Ti-45Al-xFe-yMo alloys were investigated.The results show that the amount of β（B2） phase is increased with the increase of alloying elements.Mo shows a higher capability for stabilizing the β phase than Fe.In the optimized Ti-45Al-3Fe-2Mo alloy,the grains are significantly refined to about 12 μm,and this alloy shows a very good hot ductility at the elevated temperature.

Molecular Cloning and Expression of Carotenogenic Genes in Yellowish and Mutant Whitish Loquat (Eriobotrya japonica) Fruits

ObjectiveThe study aimed to explore the factors regulating carotenoid accumulation in flesh color. MethodA loquat mutation （red-or orange-fleshed plant emerged a bud mutation of white-flesh in trunk） was used as material; HPLC analysis of β-carotene content was conducted. ResultThe β-carotene concentration in the flesh of wild and mutant types was 60.9 and 4.6 μg/g fresh weight, respectively. According to the conserved regions of genes from rose family genome, carotenogenic gene fragments in wild and mutant types were obtained. No nucleotide variation of the carotenogenic gene fragments was observed between wild and mutant genome. Real-time quantitative polymerase chain reaction （Q-PCR） was compared and one carotenogenic gene, β-ring hydroxylase （HYB） were considerably suppressed in mature mutant loquat fruits compared with that in wild. The other six carotenogenic genes were also expressed but the expression patterns appeared to be not correlated with the amount of β-carotene concentration in wild loquat flesh. ConclusionThe mutant whitish loquat lacks the ability to synthesize β-carotene because of the transcriptional down-regulation of carotenogenic gene HYB.

Triterpenes and Other Constituents from Rhaponticum uniflorum

From the roots of Rhaponticum uniflorum a new triterpene was isolated together with ursolic acid(2), 3-oxo-19a-hydroxyurs-12-en-28-oic acid (3), pomolic acid (4), 2a,3a,19a-trihydroxyurs-12-en-28-oic acid (5), arctic acid (6), catechin (7) and b-sitosterol (8). The structure of the new compound was elucidated as 2a,3a,19a,25-tetrahydroxyurs-12-en-23,28-dioic acid (1) on the basis of spectral and chemical methods.

Influence of anodization conditions on deposition of hydroxyapatite onα/βTi alloys for osseointegration:Atomic force microscopy analysis

Integrating titanium-based implants with the surrounding bone tissue remains challenging.This study aims to explore the impact of different anodization voltages(20−80 V)on the surface topography of two-phase(α/β)Ti alloys and to produce TiO_(2) films with enhanced bone formation abilities.Scanning electron microscopy coupled with energy dispersive spectroscopy(SEM−EDS)and atomic force microscopy(AFM)were applied to investigate the morphological,chemical,and surface topography of the prepared alloys and to confirm the growth of hydroxyapatite(HA)on their surfaces.Results disclosed that the surface roughness of TiO_(2) films formed on Ti−6Al−7Nb alloys was superior to that of Ti−6Al−4V alloys.Ti−6Al−7Nb alloy anodized at 80 V had the highest yields of HA after immersion in simulated body fluid with enhanced HA surface coverage.The developed HA layer had a mean thickness of(128.38±18.13)μm,suggesting its potential use as an orthopedic implantable material due to its promising bone integration and,hence,remarkable stability inside the human body.

Effect of Fish Oil on (-Adrenoceptors and the Activity of Adenylate Cyclase on Myocardial Membrane in Rats

Effects of fish oil on β-adrenoceptors as well as the activity of adenylate cyclase (AC) on rat myocardial membrane were investigated.Supplementation with fish oil had no significant effect on basal activity of AC on myocardial membrane whereas it could markedly inhibit the AC activity stimulated by isoproterenol (ISO). Radioligand binding assays showed that supplementation with fish oil had no effect on Bmax and Kd, compared with saline control. However, supplementation with sheep oil could markedly reduce both the Kd and Bmax, compared with saline control. And the Kd of sheep oil group was greatly decreased than that of fish oil group. The results suggested that supplementation with fish oil mainly affected the activation of AC, not β-adrenoceptor itself.

Enzymatic Transformation of Notoginsenoside Fe by β-Glucanase

Aim An industrial enzyme β-glucanase was used to transfortn notoginsenoside Fe for the first time. Methods Notoginsenoside Fe was isolated from the leave saponin of Panax notoginseng （Burk.） Chen FH. The enzymatically transformed compounds were detected by HPLC and two transformed compounds were identified as 20 （S） -protopanaxadiol-20- O- α-L-arabinofuranosyl （ 1→6 ） - β-gluco- pyranoside, ginsenoside-Mc） and 20（S）-protopanaxadiol-20-O-β-D-glucopyranoside compound-K （C-K） respectively on the basis of their ^1H NMR and ^13 C NMR spectral data. Results Based on the enzymolytic kinetic curve, the transformation rate of notoginsenoside Fe reached 95% after 24 h. Conclusion The enzymatic transformation pathway of notoginsenoside Fe by β-glucanase has been proposed as notoginsenoside Fe→ginsenoside Mc→C-K.

Fe-Beta zeolite for selective catalytic reduction of NO_x with NH_3:Influence of Fe content

Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of （2.6, 6.3 and 9） wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content （2.6 wt%）, Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3＋ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.

Effects of current density on preparation and performance of Al/conductive coating/α-PbO_2-Ce O_2-TiO_2/β-Pb O_2-MnO_2-WC-ZrO_2 composite electrode materials

Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy（EDXS）, anode polarization curves, quasi-stationary polarization（Tafel） curves, electrochemical impedance spectroscopy（EIS）, scanning electron microscopy（SEM）, and X-ray diffraction（XRD）. Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential（0.610 V at 500 A/m2） for oxygen evolution, the best electrocatalytic activity, the longest service life（360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2）, and the lowest cell voltage（2.75 V at 500 A/m2）. Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.

Effects of surface nanocrystallization on corrosion resistance of β-type titanium alloy

Surface mechanical attrition treatment (SMAT) was performed on biomedicalβ-type TiNbZrFe alloy for 60 min at room temperature to study the effect of surface nanocrystallization on the corrosion resistance of TiNbZrFe alloy in physiological environment. The surface nanostructure was characterized by TEM, and the electrochemical behaviors of the samples with nanocrystalline layer and coarse grain were comparatively investigated in 0.9% NaCl and 0.2% NaF solutions, respectively. The results indicate that nanocrystallines with the size of 10-30 nm are formed within the surface layer of 30 μm in depth. The nanocrystallized surface behaves higher impedance, more positive corrosion potential and lower corrosion current density in 0.9%NaCl and 0.2%NaF solutions as compared with the coarse grain surface. The improvement of the corrosion resistance is attributed to the rapid formation of stable and dense passive film on the nanocrystallized surface of TiNbZrFe alloy.

Termination of TGF-β Superfamily Signaling Through SMAD Dephosphorylation——A Functional Genomic View

The transforming growth factor-β （TGF-β） and related growth factors activate a broad range of cellular responses in metazoan organisms via autocrine, paracrine, and endocrine modes. They play key roles in the pathogenesis of many diseases especially cancer, fibrotic diseases, autoimmune diseases and cardiovascular diseases. TGF-β receptor-mediated phosphorylation of R-SMADs represents the most critical step in the TGF-β signaling pathways that triggers a cascade of intracellular events from SMAD complex assembly in the cytoplasm to transcriptional control in the nucleus. Conversely, dephosphorylafion of R-SMADs is a key mechanism for terminating TGF-β signaling. Our labs have recently taken an integrated approach combining functional genomics, biochemistry and development biology to describe the isolation and functional characterization of protein phosphatase PPM1A in controlling TGF-β signaling. This article briefly reviews how dynamic phosphorylation and dephosphorylation of SMADs control or fine-tune the signaling strength and duration and ultimately the physiological consequences in TGF-β signaling.

Effects of on-line solution and off-line heat treatment on microstructure and hardness of die-cast AZ91D alloy

The effects of on-line solution, off-line solution and aging heat treatment on the microstructure and hardness of the die-cast AZ91D alloys were investigated. Brinell hardness of die-cast AZ91D alloy increases through on-line solution and off-line aging treatment but decreases after off-line solution treatment. By X-ray diffractometry, optical microscopy, differential thermal analysis, scanning electron microscopy and X-ray energy dispersive spectroscopy, it is found that the microstructures of the die-cast AZ91D magnesium alloy before and after on-line solution and off-line aging are similar, consisting of α-Mg and β-Al12Mg17. The precipitation of Al element is prevented by on-line solution so that the effect of solid solution strengthening is enhanced. The β-Al12Mg17 phases precipitate from supersaturated Mg solid solution after off-line aging treatment, and lead to microstructure refinement of AZ91D alloy, so the effect of precipitation hardening is enhanced. The β-Al12Mg17 phases dissolve in the substructure after off-line solution treatment, which leads to that the grain boundary strengthening phase is reduced significantly and the hardness of die cast AZ91D is reduced.

Studies on the Chemical Constituents of Evodia rutaecarpa Benth

Nine indole alkaloids and one aromatic amine were isolated from Evodia rutaecarpa Benth. Their structures were identified as evodiamine(1),rutaecarpine(2),formyldihydrorutaecarpine(3),goshuyuamide I(4),evodiamide(5),hydroxyevodiamine(6),β carboline(7),1,2,3,4 tetrahydro 1 oxo β carboline(8),dehydroevodiamine(9)and N methylanthranylamide(10).Compound 8 was a new natural product. Compound 7 was for the first time isolated from Evodia.

EIS studies the effect of Zinc to Al-Zn alloy used for cathodic protection in 3% NaCl solution

Electrochemical impendence spectroscopy （EIS） is applied to investigate the dissolution behavior of Al-Zn alloys in 3% NaCl solution at different polarization potentials. A new reaction model is proposed, and the activation mechanism of zinc in Al-Zn alloys is achieved. There are three intermediates in the dissolution process： Znad^＋, Znad^2＋ and Alad^＋, ,of which only Zni can activate Al-Zn alloys. Most Znnd^＋ is produced by β-phase,and the alloys with 2. 3% - 3. 8% （wt） Zn dissolve rapidly. The Al-Zn alloys of heart-shaped EIS are active in 3% NaCl solution, thus EIS characteristic can be used to distinguish the activa-tion of Al-Zn alloys.

Phospho-control of TGF-β superfamily signaling

Members of the transforming growth factor-β （TGF-β） family control a broad range of cellular responses in metazoan organisms via autocrine, paracrine, and endocrine modes. Thus, aberrant TGF-β signaling can play a key role in the pathogenesis of several diseases, including cancer. TGF-β signaling pathways are activated by a short phospho-cascade, from receptor phosphorylation to the subsequent phosphorylation and activation of downstream signal transducers called R-Smads. R-Smad phosphorylation state determines Smad complex assembly/disassembly, nuclear import/export, transcriptional activity and stability, and is thus the most critical event in TGF-β signaling. Dephosphorylation of R-Smads by specific phosphatases prevents or terminates TGF-β signaling, highlighting the need to consider Smad （de）phosphorylation as a tightly controlled and dynamic event. This article illustrates the es- sential roles of reversible phosphorylation in controlling the strength and duration of TGF-β signaling and the ensu- ing physiological responses.

Targeted migration and differentiation of engrafted neural precursor cells in amyloid β-treated hippocampus in rats

Objective To observe the migration and differentiation of the neural precursor cells （NPCs） that derived from murine embryonic stem cells （ESCs） when they were transplanted into amyloid β （Aβ）-treated rat hippocampus. Methods MESPU35, a murine ESC cell line that express the enhanced green fluorescent protein （EGFP）, was induced differentiation into nestin-positive NPCs by modified serum-free methods. The Aβ plaques and the differentiation of the grafted cells were observed by immunofluorescent staining. Results Comparing 16 weeks with 4 weeks post-transplantation, the migration distance increased about 5 times; the rate of migratory NPCs differentiating into glial fibrillary acidic protein （GFAP）-positive cells kept rising from （30.41 ± 1.45）% to （49.25± 1.23）%, and the rate of NPCs differentiating into neurofilament 200 （NF200） positive cells increased from （16.68±0.95）% to （27.94± 1.21）%. Meanwhile, the GFAP-positive cells targeting to the ipsilateral side of Aβ plaques increased from 60.2% to 81.3 %, while the NF200-positive cells increased from 61.3% to 84.1%. The migration distance had significant positive linear correlations to the neuronal differentiation rate （r = 0.991） and to the astrocytic differentiation rate （r = 0.953）. Conclusion Engrafted NPCs migrate targetedly to the Aβ injection site and differentiate into neurons and astrocytes.

Effect of carbon on microstructures of Ti-45Al-3Fe-2Mo-xC alloy

The effect of carbon addition on the microstructures of TiAl-based alloy（Ti-45Al-3Fe-2Mo） was studied.The proportion of β/B2 phase reduces with the content of carbon increasing,while the colony size increases.With increasing the carbon content,the lamellar spacing first decreases from 267 nm（Ti-45Al-3Fe-2Mo） to 237 nm（Ti-45Al-3Fe-2Mo-0.3C） and 155 nm（Ti-45Al-3Fe-2Mo-0.5C）,but then increases to 230 nm（Ti-45Al-3Fe-2Mo-1.0C） with further increase in C level,which is affected by the inhibition of carbon atom and precipitation of carbides at the lamellar interface.Precipitation of carbides shows a response to aging time at 800 ℃.P-type carbides grow up at the boundaries and near the dislocation areas with the prolonging of aging time.And these carbides are projected different morphology in different beam directions（BD）.The effects of these microstructural modifications were examined and the observations were discussed.