Preparation and electro-catalytic activity of nanoporous palladium by dealloying rapidly-quenched Al_(70)Pd_(17)Fe_(13) quasicrystalline alloy

The formation of nanoporous Pd was studied by electro-chemical dealloying a rapidly-quenched Al70Pd17Fe13 quasicrystal alloy in dilute NaCl aqueous solution,and the electro-catalytic activity of the nanoporous Pd towards methanol electro-oxidation was evaluated by cyclic voltammetry in 1 mol/L KOH solution.XRD and TEM analyses revealed that nano-decomposition of quasicrystal grains occurred in the initial stage of dealloying,and the fully dealloyed sample was composed of FCC-Pd phase.Scanning electron microscopy observation indicated that a maze-like nanoporous pattern was formed in the dealloyed sample,consisting of percolated pores of 5.20 nm in diameter in a skeleton of randomly-orientated Pd nano-ligaments with a uniform thickness of^5 nm.A retention of^12 at.%Al in the Pd nano-ligments was determined by energy dispersive X-ray spectroscopy(EDS).The nanoporous Pd demonstrated obvious electro-catalytic activity towards methanol electro-oxidation in alkaline environment.

Evaluation of high-risk factors and the diagnostic value of alpha-fetoprotein in the stratification of primary liver cancer

BACKGROUND Alpha-fetoprotein(AFP)is one of the diagnostic standards for primary liver cancer(PLC);however,AFP exhibits insufficient sensitivity and specificity for diagnosing PLC.AIM To evaluate the effects of high-risk factors and the diagnostic value of AFP in stratified PLC.METHODS In total,289 PLC cases from 2013 to 2019 were selected for analysis.First,the contributions of high-risk factors in stratifying PLC were compared according to the following criteria:Child–Pugh score,clinical stage of liver cirrhosis,tumor size,and Barcelona Clinic Liver Cancer(BCLC)stage.Then,the diagnostic value of AFP was evaluated in different stratifications of PLC by receiver operating characteristic curves.For PLC cases in which AFP played little role,the diagnostic values of carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA 19-9),gamma-glutamyl transferase(GGT),and AFP were analyzed.RESULTS The roles of high-risk factors differed in stratified PLC.The incidence of smoking and drinking history was higher in PLC with Child–Pugh scores of C(P<0.0167).The hepatitis B virus(HBV)infection rate in PLC with cirrhosis was more than in PLC without cirrhosis(P<0.0167).Small tumors were more prone to cirrhosis than large tumors(P<0.005).BCLC stage D PLC was more likely to be associated with HBV infection and cirrhosis(P<0.0083).AFP levels were higher in PLC with cirrhosis,diffuse tumors,and BCLC stage D disease.In diagnosing PLC defined as Child–Pugh A,B,and C,massive hepatoma,diffuse hepatoma,BCLC stage B,C,and D,and AFP showed significant diagnostic value[all area under the curve(AUC)>0.700].However,these measures were meaningless(AUC<0.600)in small hepatomas and BCLC A stage PLC,but could be replaced by the combined detection of CEA,CA 19-9,GGT,and AFP(AUC=0.810 and 0.846,respectively).CONCLUSION Stratification of PLC was essential for precise diagnoses and benefited from evaluating AFP levels.

Screening of lymph nodes metastasis associated lncRNAs in colorectal cancer patients

AIM: To screen lymph nodes metastasis associated long noncoding RNAs (lncRNAs) in colorectal cancer through microarray analysis.

Influence of spherical inclusions on effective thermoelectric properties of thermoelectric composite materials

A homogenization theory is developed to predict the influence of spherical inclusions on the effective thermoelectric properties of thermoelectric composite materials based on the general principles of thermodynamics and Mori-Tanaka method.The closed-form solutions of effective Seebeck coefficient,electric conductivity,heat conductivity,and figure of merit for such thermoelectric materials are obtained by solving the nonlinear coupled transport equations of electricity and heat.It is found that the effective figure of merit of thermoelectric material containing spherical inclusions can be higher than that of each constituent in the absence of size effect and interface effect.Some interesting examples of actual thermoelectric composites with spherical inclusions,such as insulated cavities,inclusions subjected to conductive electric and heat exchange and thermoelectric inclusions,are considered,and the numerical results lead to the conclusion that considerable enhancement of the effective figure of merit is achievable by introducing inclusions.In this paper,we provide a theoretical foundation for analytically and computationally treating the thermoelectric composites with more complicated inclusion structures,and thus pointing out a new route to their design and optimization.

Well Dispersed SnO2 Nanoclusters Preparation and Modulation of Metal-Insulator Transition Induced by Ionic Liquid

Tin dioxide (SnO2) has attracted broad interest due to its particular gas-sensor property. Nano- or atom-scale SnO2 material has always been the aim in order to ultimately improve the sensitivity. However, until now, it remains difficult to synthesize SnO2 nanoclusters by using traditional methods. In the present work, we have achieved the preparation of SnO2 nanoclusters by using the cluster beam deposition technique. The obtained nanoclusters were well characterized by high resolution transmission electron microscope HR-TEM. Results indicated the formation of the well-dispersed SnO2 nanoclusters with uniform size distribution (5-7 nm). Furthermore, an obvious metal insulator transition was observed by gating with ionic liquid. Combined with theory calculation, the corresponding mechanism was systematically analyzed from oxygen vacancy induced electron doping.

Transient thermal cracking associated with non-classical heat conduction in cylindrical coordinate system

This paper studies the fracture behavior of a thermoelastic cylinder subjected to a sudden temperature change on its outer surface within the framework of non-classical heat conduction.The heat conduction equation is solved by separation of variable technique.Closed form solution for the temperature field and the associated thermal stress are established.The critical parameter governing the level of the transient thermal stress is identified.Exact expression for the transient stress intensity factor is obtained for a crack in the cylinder.The difference between the non-classical solutions and the classical solution are discussed.It is found that the traditional classical heat conduction considerably underestimates the transient thermal stress and thermal stress intensity factor.

Laparoscopic partial splenectomy in the treatment of splenic ectopic pregnancy

Ectopic pregnancy is a pregnancy that occurred outside the uterus,usually in the fallopian tube,followed by other abdominal pregnancies.Ectopic pregnancy could not develop normally to term and requires sufficient evaluation and intervention with medication or surgery in most cases(1).As a rare form of abdominal pregnancy(2),splenic ectopic pregnancy could be treated by drug treatment(3)or surgical interventions,including laparotomy and laparoscopy,which focused on total splenectomy(4,5).A previous study(6)indicated that laparoscopic partial splenectomy for selected patients was safe and feasible.Due to the fragile texture of the spleen,the suture method during laparoscopic partial splenectomy was technically demanding since it might encounter higher risk of splenic vascular hemorrhage than total splenectomy.Hence,few reports focused on the treatment of splenic ectopic pregnancy via laparoscopic partial splenectomy(7).In order to avoid the potential severe complications such as hemoperitoneum(8)caused by drug treatment alone,and to avert impaired hematopoietic and immune function caused by total splenectomy,we herein presented a case(Video 1)of a 30-year-old woman(gravida 2,para 1)undergoing laparoscopic partial splenectomy performed by hepatobiliary surgeons to treat splenic ectopic pregnancy.