Laser-optimized Pt-Y alloy nanoparticles embedded in Pt-Y oxide matrix for high stability and ORR electrocatalytic activity

The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday technology.While nanostructured Pt catalysts are to date the best available systems in terms of activity,the same is not true for stability,particularly under operating conditions.In this work,Pt_(Х)Y alloy nanoparticles are proposed as active and durable electrocatalysts for ORR.Pt_(Х)Y nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in liquid.The novel integrated laser-assisted methodology succeeded in producing Pt_(Х)Y nanoparticles with the ideal size(<10 nm)of commercial Pt catalysts,yet resulting remarkably more active with E_(1/2)=0.943 V vs.RHE,specific activity=1095μA cm^(-2) and mass activity>1000 A g^(-1).At the same time,the nanoalloys are embedded in a fine Pt oxide matrix,which allows a greater stability of the catalyst than the commercial Pt reference,as directly verified on a gas diffusion electrode.

Adaptive Window Based 3-D Feature Selection for Multispectral Image Classification Using Firefly Algorithm

Feature extraction is the most critical step in classification of multispectral image.The classification accuracy is mainly influenced by the feature sets that are selected to classify the image.In the past,handcrafted feature sets are used which are not adaptive for different image domains.To overcome this,an evolu-tionary learning method is developed to automatically learn the spatial-spectral features for classification.A modified Firefly Algorithm(FA)which achieves maximum classification accuracy with reduced size of feature set is proposed to gain the interest of feature selection for this purpose.For extracting the most effi-cient features from the data set,we have used 3-D discrete wavelet transform which decompose the multispectral image in all three dimensions.For selecting spatial and spectral features we have studied three different approaches namely overlapping window(OW-3DFS),non-overlapping window(NW-3DFS)adaptive window cube(AW-3DFS)and Pixel based technique.Fivefold Multiclass Support Vector Machine(MSVM)is used for classification purpose.Experiments con-ducted on Madurai LISS IV multispectral image exploited that the adaptive win-dow approach is used to increase the classification accuracy.

Growth morphology and evolution of quasicrystal in as-solidified Y-rich Mg-Zn-Y ternary alloys

A petal-like icosahedral quasicrystal with five branches,which is considered to be the representative morphology of the icosahedral quasicrystal,has been observed in the Y-rich Mg-Zn-Y ternary alloys. Moreover,the polygon-like morphology,another pattern of the icosahedral quasicrystal,has also been found in the Y-rich Mg-Zn-Y ternary alloys. The latter morphology results from the evolution of the former one. The growth mechanism of the petal-like morphology of the icosahedral quasicrystal was also discussed. Alloying composition,i.e.,Y element content,is a major factor inducing the morphology evolution of the icosahedral quasicrystal.

MICROSTRUCTURES AND PROPERTIES OF RECIPROCATINGLY EXTRUDED Mg-6.4Zn-1.1Y ALLOYS

An icosahedral Mg3 YZn6 quasicrystalline phase can be produced in Mg-Zn- Y system alloys when a proper amount of Zn and Y is contained, and it is feasible to prepare the quasicrystal phase-reinforced low-density magnesium alloy. In this article, phase constituents and the effect of reciprocating extrusion on microstructures and properties of the as-cast Mg-6.4Zn-1.1 Y alloy are analyzed. The microstructure of the as-cast Mg-6.4Zn-1.1 Y alloy consists of the α-Mg solid solution, icosahedral Mg3YZn6 quasicrystal, and Mg3 Y2Zn3 and MgZn2 compounds. After the alloy was reciprocatingly extruded for four passes, grains were refined, Mg3 Y2 Zn3 and MgZn2 phases dissolved into the matrix, whereas, Mg3 YZn6 precipitated and distributed uniformly. The alloy possesses the best performance at this state; the tensile strength, yield strength, and elongation are 323.4 MPa, 258.2 MPa, and 19.7%, respectively. In comparison with that of the as-cast alloy, the tensile strength, yield strength, and elongation of the reciprocatingly extruded alloy increase by 258.3%, 397.5%, and 18 times, respectively. It is concluded that reciprocating extrusion can substantially improve the properties of the as-cast Mg-6.4Zn-1.1 Y alloy, particularly for elongation. The high performance of the Mg-6.4Zn-1.1 Y alloy after reciprocating extrusion can be attributed to dispersion strengthening and grain-refined microstructures.

The effect of traditional Chinese medicine──Tian Gui Recipeon obesity and anovulation in androgen-sterilized rats

Objective: A traditional Chinese medicine Tian Gui Recipe (TGR) has been used to effectively treat clomiphene resistant anovulatory disease and obesity, especially in polycystic ovary syndrome (PCOS) cases with hyperinsulinemia. The effect of TGR on obesity and anovulation was investigated in androgen-sterilized rats (ASR). Methods: Female SD rats at the age of 9 days were divided into 3 groups. Group ASR (n=15): anovulation was demonstrated at the age of 70 days by vaginal smear in rats while 1. 25 mg of testosterone propionate was injected subcutaneously on its 9th neonatal day. Group A+H (n = 25): TGR were administered to ASR at the age of 80 days for 3 weeks. Rats with regular estrous cycle and ovulation after herbal treatment were included in this group. Group C (n = 15): normal ovulated rats were recruited. Around the age of 112 days or on proestrous day, all rats were sacrificed under anesthesia. Serum leptin, testosterone (T), estrogen (E2), follicular stimulating hormone (FSH), luteinizing hormone (LH) levels were measured with radioimmunoassay (RIA). Double immunofluorescent staining combined with confocal laser scanning microscope and dual in situ hybridization were carried out on sections through areas of arcuate nucleus (ARC) to determine whether estrogen receptor (ER) immunoreactivity (IR) or long form of leptin receptor (OB-Rb) mRNA were expressed in neuropeptide Y (NPY) immuno-and mRNA-containing neurons, and its relationship to proopiomelanocortin (POMC) mRNA-containing neurons. Immunohistochemistry and in situ hybridization were used to observe the levels of ER, NPY, gonadotrophin releasing hormone (GnRH) and gene expression levels on NPY, OB-Rb, POMC. Meanwhile, the criteria of energy state, including daily food intake, retroperitoneal fat depot pad and body weight, were measured and evaluated. Values of immunohistochemistry and in situ hybridization were expressed in mean optic density (MOD). Results: Seventeen out of the 25 rats (68%) in Group A+H were ovulated after herbal treatment. ASR characterized with significantly high metabolic rate, energy imbalance and obesity (P<0. 01, P<0. 01, P<0. 01). The mean serum leptin, T, E2 levels of group ASR were significantly higher than those of Group C and Group A+H (P< 0. 01,P<0. 01 ), while FSH, LH levels were lower (P<0. 01, P<0. 01 ). ERs were proved to be distributing in NPY-containing neurons, OB-Rb coexpressed in NPY-syn- thesizing neurons, and both NPY and POMC mRNA expressing neurons overlapped in ARC. Compared to Group C, levels of NPY mRNA and NPY, POMC mRNA expressions were increased (P<0. 01, P<0. 01, P<0. 01 ), OB-Rb mRNA, ER and GnRH immunoreactive expression were decreased significantly in the hypothalamus of ASR (P<0. 01, P<0. 01, P<0. 01 ). These dramatic neuroendocrine changes became normal in ovulated ASR after the herbal treatment (all P>0. 05). Conclusion: The elevated peripheral E2 caused by high T and leptin levels in ASR may down-regulate their corresponding receptors oriented on hypothalamic NPY- containing neurons respectively, therefore challenge the NPY mRNA and NPY, POMC mRNA overexpressions. The overexpression, of NPY, POMC gene transcription and translation stimulate food intake, promote the deposit of adipocyte tissue, and inhibit GnRH expression and GnRH/FSH, LH release, which contribute to the occurrence of obesity and anovulation in ASR. TGR may reverse these abnormal neuroendocrine cascades by lowering the levels of T, E2 and leptin.

Relationship between Heat Treatment and Corrosion Behavior of Mg-15Y Alloy

The corrosion behaviors of a basic type of RE-containing magnesium alloy Mg-15Y processed by different heat treatment methods were studied in 3.5% NaC1 solution at room temperature. The amount of Mg24Y5 phase decreased with the extending of homogenization treatment. The time for achieving dissolving equilibrium of homogenization treatment at 525, 535, and 545 ℃ was 24, 20, and 8 h, respectively. The corrosion behavior of Mg-15Y alloy was studied using immersion, hydrogen evolution and electrochemical tests. The experimental results revealed that the heat treatment improved the corrosion resistance, and the corrosion resistance became better with increasing the heat treatment time. The corrosion mode of the alloy after heat treatment was microgalvanic corrosion consisting of the cathodic Mg24Y5 phase and anodic α-Mg matrix, and Mg-15Y exhibited favorable uniform corrosion mode in NaC1 solution. The volume and increasing tendency of the homogenization treatment samples were both more than those of the as-cast sample.

Egg quality, fatty acid composition and immunoglobulin Y content in eggs from laying hens fed full fat camelina or flax seed

Background： The current study was conducted to evaluate egg quality and egg yolk fatty acids and immunoglobulin（Ig Y） content from laying hens fed full fat camelina or flax seed.Methods： A total of 75, 48-week-old Lohman brown hens were randomly allocated to 3 treatments, with 5replicates containing 5 laying hens each replicate. The hens were fed corn-soybean basal diet（Control）, or Control diet with 10 % of full fat camelina（Camelina） or flax seed（Flax） for a period of 16 wk. Hen production performance egg quality, egg yolk lipids, fatty acids and Ig Y were determined every 28 d during the experimental period.Results： Egg production was higher in hens fed Camelina and Flax than in Control hens（P 〈 0.05）. Egg weight and albumen weight was lowest in eggs from hens fed Camelina（P 〈 0.05）. Shell weight relative to egg weight（shell weight %）, and shell thickness was lowest in eggs from hens fed Flax（P 〈 0.05）. No difference was noted in Haugh unit, yolk：albumen ratio, and yolk weight. Significant increase in α-linolenic（18：3 n-3）, docosapentaenoic（22：5 n-3）and docoshexaenoic（22：6 n-3） acids were observed in egg yolk from hens fed Camelina and Flax. Total n-3 fatty acids constituted 1.19 % in Control eggs compared to 3.12 and 3.09 % in Camelina and Flax eggs, respectively（P 〈 0.05）. Eggs from hens fed Camelina and Flax had the higher Ig Y concentration than those hens fed Control diet when expressed on a mg/g of yolk basis（P 〈 0.05）. Although the egg weight was significantly lower in Camelina-fed hens, the total egg content of Ig Y was highest in eggs from hens fed Camelina（P 〈 0.05）.Conclusions： The egg n-3 fatty acid and Ig Y enhancing effect of dietary camelina seed warrants further attention into the potential of using camelina as a functional feed ingredient in poultry feeding.

STUDY ON MICROSTRUCTURE OF PLATINUM ALLOY ADDED WITH MINIMAL Y AND Zr

The microstructure, structural stability and second phase characteristic of platinum alloys added with minimal Zr and Y are studied in this paper.

Effect of Y and Gd content on the microstructure and mechanical properties of Mg-Y-RE alloys

In the application of WE43,it is found that Y_(2)O_(3)inclusion formed in the process of casting seriously reduced the mechanical properties of the products.The reduction of the mechanical properties is even more distinct when it comes to the application in the thin walled complex-precision castings.In order to decrease the Y_(2)O_(3)inclusions,Gd element was used to replace part of the Y element in Mg-Y-RE series alloys.The effect of Y content(Mg-x Y-1Gd-2Nd-0.5Zn-0.5Zr)and Y/Gd ratio(Mg-x Y-(5-x)Gd-2Nd-0.5Zn-0.5Zr)on the microstructure and mechanical properties of Mg-Y-RE alloys were investigated in this paper.With decreasing Y content,the grain size of the alloys increased,both ultimate tensile strength(UTS)and yield strength(YS)of alloys decreased monotonically.Replacing part of Y content with Gd and keeping the total rare earth content unchanged,the low Y content Mg-2Y-3Gd-2Nd-0.5Zn-0.5Zr alloy showed the same mechanical properties as the high Y content Mg-4Y-1Gd-2Nd-0.5Zn-0.5Zr alloy at both room and elevated temperatures.After solution treatment at 525°C for 8 h and aging treatment at 225°C for 10 h,the UTS,YS and elongation(ε)of Mg-2Y-3Gd-2Nd-0.5Zn-0.5Zr alloy reached 281.7 MPa,198 MPa and 11.1%at room temperature,and 216.7 MPa,171.6 MPa and 16.1%at 250°C.The new low Y content Mg-2Y-2Nd-3Gd-0.5Zn-0.5Zr alloy is expected to replace the high Y content WE43 alloys,which can be used in the complex thin-walled parts of aviation products.

Protective effects of Lingguizhugan decoction on amyloid-beta peptide (25-35)-induced cell injury Anti-inflammatory effects

In the present study, a human neuroblastoma cell line （SH-SY5Y） and BV-2 microglia were treated with amyloid-β peptide （25-35）, as a model of Alzheimer＇s disease, to evaluate the protective effects of 10-3-10-8 g/mL Lingguizhugan decoction and to examine the underlying anti-inflammatory mechanism. Lingguizhugan decoction significantly enhanced the viability of SH-SY5Y cells with amyloid-β peptide-induced injury, and lowered levels of interleukin-1β, interleukin-6, tumor necrosis factor-a and nitric oxide in the culture supernatant of activated BV-2 microglia. The effects of 103 g/mL Lingguizhugan decoction were more significant. These results suggest that Lingguizhugan decoction can protect SH-SY5Y cells against amyloid-β peptide （25-35）-induced injury in a dose-dependent manner by inhibiting overexpression of inflammatory factors by activated microglia.

Effects of titanium on microstructure and mechanical properties of ZnAl4Y alloy

The effect of Ti on the microstructure and mechanical properties of zinc-aluminum ZnAl4Y alloy has been investigated in this work. Small amount of Ti was added into ZnAl4Y alloy in the form of Al-10wt.%Ti alloy. The results show that Ti addition into ZnAl4Y alloy refines the primary η-Zn phase and increases the amount of η-Zn + α-Al eutectic structure. There exists a ternary T phase in Zn-Al-Ti alloy. Fine TiAl3 particles and Ti-Zn compounds can serve as the nucleation sites of the α-Al and η-Zn phase, respectively, resulting in the refining of the microstructure of ZnAl4Y alloy. Ti addition changes the fracture characteristics of ZnAl4Y alloy. With 0.05wt%Ti, the fracture surface of the alloy shows a lot of dimples and tearing ridges connecting the microscopic dimples, which is mainly ductile fracture morphology. Ti addition into ZnAl4Y alloy also increases the mechanical properties of the alloy. When the content of Ti is 0.05wt.%, the ZnAl4Y alloy possesses the best comprehensive mechanical properties.

Effects of toluene on thiophene adsorption over NaY and Ce(IV)Y zeolites

Zeolites NaY and Ce（IV）Y were employed as adsorbents to remove organic sulfur compounds from model gasoline （MG） solutions with and without toluene in static adsorption experiments at room temperature （RT） and atmospheric pressure. The adsorbents were characterized by XRD, XRF and pyridine infrared spectrum （IR）. The adsorption experiments show that the desulfurization performance of Ce（IV）Y is much better than that of NaY. The sulfur removal over both NaY and Ce（IV）Y decreases with the increase of toluene concentration in MG, however, the decline tendency on Ce（IV）Y is smooth, and it is steep on NaY. FT-IR spectra of thiophene adsorption indicate that thiophene molecules are mainly adsorbed on NaY via π electron interaction, but on Ce（IV）Y, in addition to the π electron interaction, both Ce^4＋-S direct interaction and protonation of thiophene also play important roles. Toluene molecules are adsorbed on NaY also via π electron interaction. Although the amount of Bronsted acid sites is increased due to the introduction of Ce^4＋ ions into NaY zeolite, it is not found to influence the adsorption mode of toluene over Ce（IV）Y. Compared with NaY zeolite, the improved desulfurization performance over Ce（IV）Y for removing organic sulfur compounds from MG solution, especially those containing large amount of aromatics, may be ascribed to the direct Ce（IV）-S interaction, which is much resistant to the influence resulted from toluene adsorption.

Upconversion luminescence of Y_2O_3:Er^(3+), Yb^(3+) nanoparticles prepared by a homogeneous precipitation method

Y2O3： Er^3＋, Yb^3＋ nanoparticles were synthesized by a homogeneous precipitation method without and with different concentrations of EDTA 2Na. Upconversion luminescence spectra of the samples were studied under 980 nm laser excitation. The results of XRD showed that the obtained Y2O3：Er^3＋,Yb^3＋ nanoparticles were of a cubic structure. The average crystallite sizes calculated were in the range of 28-40 nm. Green and red upconversion emission were observed, and attributed to ^2H11/2,^4S3/2→^4I15/2 and ^4F9/2→^4I15/2 transitions of the ion, respectively. The ratio of the intensity of green emission to that of red emission drastically changed with a change in the EDTA 2Na concentration. In the sample synthesized without EDTA, the relative intensity of the green emission was weaker than that of the red emission. The relative intensities of green emission increased with the increased amount of EDTA 2Na used. The possible upconversion luminescence mechanisms were discussed.

Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

Influence of Ganoderma lucidum spores on the levels of neuropeptide Y and somatostatin in brains of seizure rats

BACKGROUND： Previous research has revealed that somatostatin can induce epilepsy, and that the levels of neuropeptide Y may increase and become more active in brain areas with epileptic seizures. OBJECTIVE： To observe the effect of Ganoderma luciclum spore powder on the neuropeptide Y and somatostatin content in the cerebral cortex and hippocampal regions of seizure rats induced by pentylenetetrazol （PTZ）. Furthermore, to verify any effect of Ganoderma lucidum spore powder on inhibition of epileptic seizures. DESIGN, TIME AND SETTING： A randomized group animal study was performed in August 2007 in the School of Basic Medical Sciences, Jiamusi University （Jiamusi, Heilongjiang, China）. MATERIALS： Thirty healthy, male, Wistar rats, aged 12 weeks and weighing 180-220 g, were taken as the experimental animals. PTZ （Sigma Company, United States） was used to induce epilepsy. Ganoderma lucidum spores （Leyss, ex Fr variety） were purchased from Jiamusi City Wild Growing Case of the Ganoderma Lucidum （China）. Rabbit anti-somatostatin antibodies and secondary antibodies were purchased from Wuhan Boster Company （China）. Neuropeptide Y radioimmunoassay kit was purchased from Beijing Furui Biotechnology Company （China）. METHODS： Thirty rats were randomly divided into three groups： a control group, an epilepsy model group and a Ganoderma lucidum spore-treated group. Each group contained 10 animals. Rats in the epilepsy model group were treated with intraperitoneal injections of PTZ and gastric perfusion of physiologic saline. In the Ganoderma lucidum spore-treated group, intraperitoneal injection of PTZ and gastric perfusion of Ganoderma lucidum spore powder were administered. The blank control group was only administered with the physiological saline by intraperitoneal injection and gastric perfusion. MAIN OUTCOME MEASURES： Immunohistochemical staining and radioimmunoassay methods were used to observe the changes of somatostatin and neuropeptide Y content in brain tissue of epileptic rats, as well as the morphology of neurons. RESULTS： All 30 rats were involved in the result analysis, without any loss. The number of somatostatin immunoreacted positive cells in the cerebral cortex and hippocampus was significantly increased in the epilepsy model group compared to the blank control group （P 〈 0.01）. The number of somatostatin immunoreacted positive cells in cerebral cortex and hippocampus was significantly decreased in the Ganoderma lucidum spore-treated group compared to the epilepsy model group （P 〈 0.01）. The contents of neuropeptide Y in cerebral cortex and hippocampus were significantly increased in the epilepsy model group compared to the blank control group （P 〈 0.01）. The contents of neuropeptide Y in the cerebral cortex and hippocampus were significantly decreased in the Ganoderma lucidum spore-treated group compared to the epilepsy model group （P 〈 0.05）. The epilepsy seizures in the Ganoderma lucidum spore-treated group were obviously reduced compared to the epilepsy model group. CONCLUSION： Ganoderma lucidum spore powder was able to reduce the somatostatin and neuropeptide Y content in the cerebral cortex and hippocampus effectively, so as to achieve an anti-epileptic function and protect neurons from being damaged.

Quick recovery and characterization of cell-free DNA in seminal plasma of normozoospermia and azoospermia： implications for non-invasive genetic utilities

We established a quick and reliable method for recovering cell-free seminal DNA （cfsDNA）, by using the binding-washing-elution procedure on the DNA purification column. Low variations （below 15%） among the triplicate values of cfsDNA quantity verified the reproducibility of our cfsDNA recovery method. Similar cfsDNA yield and size distribution between seminal plasma acquired by filtration and centrifugation confirmed the presence of cfsDNA. To investigate the general characterization of cfsDNA, the quantitation and size distribution of cfsDNA from normozoospermic and azoospermic semen were analyzed by real-time PCR and electrophoresis, respectively. CfsDNA concentration in semen with normozoospermia （n = 11） was 1.34 ± 0.65 μg ·mL^-1, whereas a higher cfsDNA concentration was observed in azoospermia （2.56 ± 1.43 μg ·mL^-1, n = 9）. The continuous distribution of DNA fragments ranging from -1 kb to 15 kb and a spectrum of multiples of 180-bp fragments were observed in each normozoospermic and azoospermic sample. Distinct characteristic DNA ladder fragmentations in some azoospermic samples implicated that cfsDNA originate partly from apoptotic cells. CfsDNAs of 36 selected azoospermic patients with known information of Y chromosome microdeletion were subjected to the same microdeletion analysis by multiplex PCR and PCR amplification of sY114 （1 450 bp）. All multiplex PCR reactions with cfsDNA amplified successfully and provided the same result as leukocyte DNA. PCR amplification of sY114 gave a 1 450-bp amplicon as expected. Our data suggested the potential use of cfsDNA in search of biomarker or diagnostic procedures.

Contra-lateral liver lobe hypertrophy after unilobar Y90 radioembolization:An alternative to portal vein embolization?

Liver resection(LR) with negative margins confers survival advantage in many patients with hepatic malignancies.However,an adequate future liver remnant(FLR) is imperative for safe LR.Presently,in patients with an inadequate FLR; the 2 most established clinical techniques performed to induce liver hypertrophy are portal vein embolization(PVE) and portal vein ligation.More recently,it has been observed that patients who undergo treatment via Y90 radioembolization experience hypertrophy of the contra-lateral untreated liver lobe.Based on these observations,several investigators have proposed the potential use of this modality as an alternative technique for increasing the FLR prior to liver resection.Y90 radioembolization induces hypertrophy at a slower rate than PVE but has the added advantage of concomitant local disease control and tumour downstaging.

Grain boundary restructuring and La/Ce/Y application in Nd–Fe–B magnets

Since the 1980 s, Nd–Fe–B with largest energy product(BH)max approaching the theoretical limit has become the landmark of permanent magnetic material.The application spectrum for Nd–Fe–B continues to expand over time both in the industrial and commercial sectors, which leads to growing research interests for solving the long-standing drawbacks of Nd–Fe–B, i.e., poor corrosion resistance, low coercivity, high Dy/Tb and low La/Ce/Y consumption.Concerning the above obstacles, we aim to present the novel grain boundary restructuring(GBR) approach, from GB design, processing, to structure evolution and property evaluation with a focus on the corrosion and coercivity mechanism of the restructured 2:14:1-typed magnets.Starting with an introduction to the fundamental of GBR, two representative examples,high-electrode-potential(Pr, Nd)32.5Fe62.0Cu5.5 and low-melting-point Dy71.5Fe28.5, are given with detailed descriptions of the advantages of GBR to enhance the intrinsic anti-corrosion stability and to strengthen the coercivity at low Dy consumption.Microstructure–property correlations are established to understand the critical importance of regulating the restructured GB phase to maximize the all-round performance of the 2:14:1-typed permanent magnets.Aiming at sustainable and balanced development of rare earth(RE) industry, the proceeding section proposes new prototypes of La–Ce and Y–Ce co-substitutions with dual benefits of stabilizing the 2:14:1 tetragonal phase and strengthening the intrinsic hard magnetism.The findings of additional REFe2 intergranular phase delight that the GBR approach also opens up a new horizon of research and application to develop high-performance La/Ce/Y-rich permanent magnets with deliberately tailored GB phase.

Effect of trace yttrium on the microstructure,mechanical property and corrosion behavior of homogenized Mg-2Zn-0.1Mn-0.3Ca-xY biological magnesium alloy

The effects of trace yttrium(Y)element on the microstructure,mechanical properties,and corrosion resistance of Mg-2Zn-0.1Mn-0.3Ca-xY(x=0,0.1,0.2,0.3)biological magnesium alloys are investigated.Results show that grain size decreases from 310 to 144µm when Y content increases from 0wt%to 0.3wt%.At the same time,volume fraction of the second phase increases from 0.4%to 6.0%,yield strength of the alloy continues to increase,and ultimate tensile strength and elongation decrease initially and then increase.When the Y content increases to 0.3wt%,Mg_(3)Zn_(6)Y phase begins to precipitate in the alloy;thus,the alloy exhibits the most excellent mechanical property.At this time,its ultimate tensile strength,yield strength,and elongation are 119 MPa,69 MPa,and 9.1%,respectively.In addition,when the Y content is 0.3wt%,the alloy shows the best corrosion resistance in the simulated body fluid(SBF).This investigation has revealed that the improvement of mechanical properties and corrosion resistance is mainly attributed to the grain refinement and the precipitated Mg_(3)Zn_(6)Y phase.

Expression of Neuropeptide Y in Human Pituitary Adenoma

OBJECTIVE Neurppeptide Y (NPY) acts as a neuroendocrine modulator in the anterior pituitary, and NPY mRNA and NPY-immunoreactivity have been detected in normal human anterior pituitaries. However, only a few studies of NPY expression in human pituitary adenomas have been published. Our study was conducted to determine whether or not adenoma-tous cells express NPY, to investigate the relationship between NPY expression and the subtypes of pituitary adenoma and to explore the clinical significance of NPY. METHODS The study included tissues from 58 patients with pituitary adenomas who underwent surgery because of their clinical diagnosis. Using a highly specific anti-NPY polyclonal antibody, immunohistochemi-cal analysis was performed on the surgically removed pituitary adenomas. Six fresh specimens also were examined using immuno-electron microscopy. NPY was labeled with colloidal gold in order to study the distribution of NPY at the subcellular level. RESULTS The NPY expression level was significantly different among subgroups of pituitary adenomas (P<0.05). NPY was immuno-detected in 58.6% of all adenomas, in 91.7% of gonadotrophic adenomas and in 14.3% of prolactinomas. NPY expression was slightly lower in invasive pituitary adenomas compared to noninvasive adenomas, but the difference was not significant (t=1.81, P>0.05). Of particular interest was the finding that vascular endothelial cells showed positive NPY expression in some pituitary adenomas. Parts of strongly positive tumor cells were seen in channels formed without endothelial cells, but which contained some red blood cells in a formation similar to so-called vasculogenic mimicry. Im-muno-electron microscopy demonstrated that 4 of the 6 fresh specimens displayed positive NPY staining with a high density of gold particles located mainly in the secretory granulas. In addition, gold particles were sparsely detected in the rough endoplasmic reticulum and cell matrix. CONCLUSION NPY exists in pituitary adenomas and its expression level was related to the types and biological characteristics of the pituitary adenomas. NPY may have a depressive effect on tumor cellular proliferation in pituitary adenomas. NPY possibly participates in modulating an-giogenesis and hemodynamic changes in pituitary adenomas.