Microstructure and mechanical properties of as-cast and extruded biomedical Mg-Zn-Y-Zr-Ca alloy at different temperatures

A type of biomedical magnesium alloy Mg-3Zn-1Y-0.6Zr-0.5Ca was cast and extruded at three extrusion temperatures of 270, 300 and 330 °C. The microstructure and mechanical properties of the cast and extruded alloys, tailored at different extrusion parameters, were investigated using tensile tests, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometry, transmission electron microscopy and electron backscattered diffraction. Optimum comprehensive mechanical properties are achieved in the alloy extruded at 270 °C, the ultimate tensile strength and the elongation reach 315 MPa and 26%, respectively, which is deemed to be associated with the grain refinement, weak basal texture and second phases strengthening. After hot extrusion, extensive dynamic recrystallization is found in the Mg-3Zn-1Y-0.6Zr-0.5Ca alloy. Continuous Mg3YZn6 phase bands are gradually broken into discontinuous chain-like or dot-like structures, and the grains distribute more uniformly. The as-extruded Mg-3Zn-1Y-0.6Zr-0.5Ca alloy exhibits a weak texture with (0001) basal planes parallel to the extrusion direction.

The effect of chelating agent on hydrodesulfurization reaction of ordered mesoporous alumina supported Ni Mo catalysts

In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence of EDTA on the physical and chemical properties of the modified catalysts was also studied.The characteristic results showed that the addition of EDTA could adjust the metal-support interaction and improved the acidity of the corresponding catalyst.Combined with the catalytic performance results,the EDTA-modified Ni Mo E(1.0)/OMA catalyst displays the highest DBT hydrodesulfurization conversion(97.7%).

Expression of multidrug-resistance associated proteins in human retinoblastoma treated by primary enucleation

AIM： To reveal the expression of multidrug-resistance associated proteins： glutathione-S-transferase π（GSTπ）, P-glycoprotein（P-gp） and vault protein lung resistance protein（LRP） in retinoblastoma（RB） without any conservative treatment before primary enucleation and to correlate this expression with histopathological tumor features. METHODS： A total of 42 specimens of RB undergone primary enucleation were selected for the research. Sections from the formalin-fixed, paraffin-embedded specimens were stained with HE and immunohistochemistry to detect the expression of GSTπ, P-gp and LRP.RESULTS： GSTπ was expressed in 39/42（92.86%） RBs and in 9/9（100%） well-differentiated RBs. P-gp/GSTπ was found in 30（71.42%） of 42 RBs. Totally 9（21.43%） tumors were well differentiated and 33（78.57%） were poorly differentiated. Totally 15（35.71%） eyes had optic nerve（ON） tumor invasion, 36（85.71%） had choroidal tumor invasion, and 14（33.33%） had simultaneous choroidal and ON invasion. There was no statistically significant relationship between P-gp, GSTπ, LRP positivity and the degree of ocular layer tumor invasion and ON tumor invasion（P〉0.05）. CONCLUSION： RB intrinsically expresses GSTπ, P-gp and LRP. GSTπ expression is positive in 100% welldifferentiation ones, so in which way it is correlated with differentiation. But the other two proteins expressions are not related to tumor differentiation and to the degree of tumor invasion. GSTπ may be a new target of chemotherapy in RB.

Minimum Time Overtaking Problem of Vehicle Handling Inverse Dynamics Based on Two Kinds of Safe Distances

Overtaking accidents caused by improper operations performed by a driver occur frequently. However, most stud?ies on overtaking safety have neglected research into driver control input. A novel method is proposed to obtain the driver control input during the overtaking process. Meanwhile, to improve the safety of overtaking, two types of safe distances, and the time of the overtaking are considered. Path constraints are established when considering the two types of safe distances. An optimal control model is established to solve the minimum time maneuver under multiple constraints. Using the Gauss pseudospectral method, the optimal control problem is converted into a nonlinear pro?gramming problem, which is then solved through sequential quadratic programming(SQP). In addition, the e ective?ness of the proposed method is verified based on the results of a Carsim simulation. The simulation results show that by adopting an inverse dynamics method to solve the manipulation problem of the vehicle’s minimum overtaking time, the manipulation capability of a vehicle in completing an overtaking safely within the minimum time can be obtained. This method can provide a reference for research into the active safety of manned and unmanned vehicles.

Expression levels of autophagy related proteins and their prognostic significance in retinocytoma and retinoblastoma

·AIM: To discuss the prognostic significant of autophagy related proteins(ARPs) in retinoblastoma(RB)and to find the molecular marker to distinguish retinocytoma(RC) and RB by investigating the different expression profiling of microtubule-associated protein light chain 3(LC3B) and other ARPs in RC and RB.·METHODS: Specimens with retinocytoma region(RCR)or mainly composed with Flexner-Winterstein rosettes(FWR) were screen out from 219 paraffin-embedded RB samples and respectively taken as RCR group and FWR group. Others were taken as undifferentiated(UD) group.Immunochemistry(IHC) of LC3 B and electronic microscopy was used to identify autophagy. The IHC scores of LC3 B and other ARPs, such as Beclin, PTEN,p27, p16INK4 a, mTOR and BCL-2 were compared and correlation analysis was applied to find potential proteins which may involve in autophagy regulation. The prognostics significance of LC3 B was evaluated by comparing the high risk features(HRFs) in 3 groups of total 219 samples.·RESULTS: Twenty-one specimens with RCR and 36 specimens mainly composed with FWR were screen out.RCR cell had a high level of LC3 B and lots of autophagic vacuoles. Beclin, PTEN, p27 had positive correlation with LC3, and p16INK4 ahad negative correlation, while the expression of mTOR and BCL-2 in RCR and RB region did not show any difference. Cases with RCR had lower rate of HRFs than undifferentiated cases.·CONCLUSION: ARPs had different expression pattern between RCR and other pathological types of RB, and could be ideal markers to distinguish RC from RB. Our finding indicated cases with RCR had favorable prognosis just like those with FWR.

Immunohistochemical features of carcinoma ex pleomorphic adenoma and pleomorphic adenoma in the lacrimal gland

AIM: To investigate C-myc, Ki-67, pan-cytokeratin, and vimentin immunohistochemical features of carcinoma ex pleomorphic adenoma(Ca-ex-PA) and pleomorphic adenoma(PA) in the lacrimal gland in order to find some clues in the differential diagnosis between them.METHODS: We reviewed microscopic slides and clinical records of 64 cases of PA and 15 cases of Ca-ex-PA in the lacrimal gland. Immunohistochemical antibodies for C-myc, Ki-67, pan-cytokeratin, and vimentin were employed.RESULTS: Median age of PA was 43.2 y(from 21 to 75). The 35 patients(54.7%) were male and 29 patients(45.3%) were female. For the PAs, the average positivity of C-myc was 4.6%;the average proliferation index of Ki-67 was 3.2%;pan-cytokeratin was positive in ductal cells, and vimentin was positive in myoepithelial cells. Median age of Ca-ex-PA was 54.3 y(from 26 to 76). There were 7 male patients(46.7%) and 8 female patients(53.3%). Among 15 Ca-ex-PAs, there were 6 myoepithelial carcinomas, 4 adenocarcinomas, 3 epithelial-myoepithelial carcinomas, and 2 squamous cell carcinomas. For the Ca-ex-PAs, the average positivity of C-myc was 36.4%;the average proliferation index of Ki-67 was 29.2%;pan-cytokeratin was positive in all cases, and vimentin was positive in myoepithelial carcinomas.CONCLUSION: PA has a lower positivity of C-myc and Ki-67, while Ca-ex-PA had a higher positivity of these two biomarkers. These four biomarkers as a set could provide valuable clues in the differential diagnosis between Ca-exPA and PA. Our results indicate that the activation of C-myc could play an important role in the pathogenesis of Ca-exPA and PA.

Auto-cortex of crystalline lens-induced iris neovascularization

AIM:To investigate auto-cortex of crystalline lens induced iris neovascularization (INV). METHODS: Thirty-six eyes of 36 guinea-pigs were included and divided into three groups randomly in this cohort study. Group A: the right lens nucleus was extracted and the remaining cortical lens material was aspirated thoroughly.. Group B: the lens was removed and 30 mu L precipitated lens cortex was injected into the anterior chamber again. Group C: aspirated the lens cortex of the left eyes and inject them into the right anterior chambers about 10 mu L. Clinical changes were followed by slit-lamp examination and photograph. The eye balls were enucleated at the day of 2, 4, 7, 11, 13, 17 after operation. HE was used to detect the pathological changes. ' RESULTS:Group A:INV had not been observed until the end of empirical study. The stromal layer contained thick wall vessels, without expansion. Group B: All eyes developed INV. Postoperative (po) 7 days; the eyes developed intense and extensive INV. The vessels of iris expanded remarkably and neovascularization was observed erupting from it's lateral wall and stretching towards the anterior surface. Poll days, INV regressed gradually after lens cortex had been absorbed. Group C: Po four (4) days, new blood vessels liking red line were presented on the anterior surface of the iris and they were not obvious. CONCLUSION: Anterior chamber inside lens coriaceous can induce iris new blood vessels.

Highly Sensitive Silver Nanorod Arrays for Rapid Surface Enhanced Raman Scattering Detection of Acetamiprid Pesticides

The determination of pesticide residue on agricultural products is increasingly important. Exposure to pesticides can cause severe acute reactions in humans, including aplastic anemia and leukemia. In this work, we developed a rapid and sensitive method to detect acetamiprid pesticide residue based on surface-enhanced Raman scattering. Silver nanorod （AgNR） arrays were fabricated by oblique angle deposition technology and were used as SERS substrates. Prior to detection, the AgNR arrays were cleaned with nitric acid solution or a mixture of methanol and acetone. Compared to the unwashed AgNR arrays, the AgNR arrays washed with methanol and acetone shows a signal enhancement 1000 times greater than the unwashed AgNR array due to the effective removal of the impurities on its surface. The limit of detection of acetamiprid was determined to be 0.05 mg/L. In addition, the molecular structure of acetamiprid was simulated and the corresponding vibration modes of the characteristic bands of acetamiprid were calculated by density function theory. To demonstrate its practical application, the AgNRs array substrates were applied successfully to the rapid identification of acetamiprid residue on a cucumber＇s surface. These results confirmed possibility of utilizing the AgNRs SERS substrates as a new method for highly sensitive pesticide residue detection.

How did high temperature extremes in southern Xinjiang,China induce the repaid rise in jujube futures prices in the summer of 2021?

In the summer of 2021,southern Xinjiang,China,experienced a temporary period of high temperature extremes.Because of this weather event,jujube futures prices rose by more than 50%in a short time.To clarify the influence mechanism of these two events,we investigated the current status of jujube farming and collected investors’online comments.We analysed these comments specifically using textual analysis tools,such as co-word networks.Results showed that the concerns of investors about the reduction in jujube production triggered by high temperature extremes were the primary reason for the rapid rise in jujube futures prices.Especially in combination with the cultivation density of jujube and their adaptability to the growing environment,a new understanding can be obtained.That is to say,when a crop is excessively densely cultivated in a region and is highly sensitive to a meteorological variable anomaly at a certain growth stage,a less destructive local extreme weather event could induce severe panic among investors regarding production reduction and thus influence the normal changes in futures price.In response to the impact mechanisms revealed in this study,we proposed policy recommendations,such as strengthening the degree of crop damage disclosure and designing weather futures derivatives,to address similar situations in the future.This study not only fills the gap in the research on the impact paths of high temperature extremes on jujube futures prices but also has a reference value for securing the stability of futures prices of related agricultural products in the future.

Liquefaction structures induced by the M5.7 earthquake on May 28, 2018 in Songyuan, Jilin Province, NE China and research implication

An earthquake of magnitude M5.7 occurred in Yamutu village,Songyuan City,Jilin Province,NE China(45°16′12″N/124°42′35″E)on May 28,2018,with a focal depth of 13 km.The epicenter is located at the intersection of the Fuyu/Songyuan-Zhaodong Fault,Second Songhua River Fault and Fuyu North Fault which lies northwest of TanchengLujiang Fault(Tan-Lu Fault).The earthquake-induced widespread liquefaction structures and ground surface fissures within 3 km from the epicenter,caused serious disasters to the local surroundings.The visible liquefied structures include sand volcanoes,liquefied sand mounds,sand dikes and sand sills.Sand volcanoes can be divided into sand volcano with a crater,sand volcano without a crater and water volcano(no sand).Other soft-sediment deformation structures(SSDS)induced by the earthquake include deformation lamination,load and flame structures,deformation folds,dish structures,convolute bedding and water-escape structures.The formation process of the sand volcanoes comprises three stages:(1)building up excess pore-fluid pressure in the liquefied layer,(2)cracking of the low-permeable overlying layer,and(3)mixture of sand-water venting out of the ground surface.During the upward movement,the liquefied sand is injected into the low-permeable layer to form sand veins,sand sills and various types of deformation structures.Vertical distribution of seismic liquefaction structure can be divided into four zones:the thoroughly liquefied zone,the lower liquefied zone with SSDS,the upper liquefied zone with SSDS,and the ground surface liquefied zone.The liquefaction occurred at a burial depth of 2–5 m,and the thickness of liquefied sand is 2 m.NE-SW(35°–215°)trending compressive stress is possibly the seismogenic trigger of the Songyuan M5.7 earthquake that caused the fault(Fuyu/Songyuan-Zhaodong Fault)to reactivate.The study of the Songyuan seismic liquefaction structures gives insight into the prediction of modern earthquakes and disasterprone areas.Meanwhile it provides abundant basic material for studying earthquake-induced SSDS in both ancient and modern sediments.The research is obviously of great significance to reveal that the northern Tan-Lu Fault has entered a stage of active seismic activity since the twenty-first century.

Estrogen modulation of visceral pain

It is commonly accepted that females and males differ in their experience of pain. Gender differences have been found in the prevalence and severity of pain in both clinical and animal studies. Sex-related hormones are found to be involved in pain transmission and have critical effects on visceral pain sensitivity. Studies have pointed out the idea that serum estrogen is closely related to visceral nociceptive sensitivity. This review aims to summarize the literature relating to the role of estrogen in modulating visceral pain with emphasis on deciphering the potential central and peripheral mechanisms.