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Multilayered dielectric stack structures, with a layered or crested potential profile, have been proposed for use as the tunnel dielectric of nonvolatile memories for fast low-voltage programming and longer charge retention. In this work, self-consistent quantum mechanical (QM) numerical calculations, using an in-house developed charge quantization simulation program, were conducted to analyze the gate tunneling current and capacitance of metal–insulator–semiconductor (MIS) devices with tunnel dielectric stack structures. The self-consistent QM simulator takes into account polysilicon depletion, quantization effects on the carrier density, and wave penetration effects. The gate current density–gate voltage (Jg–Vg) simulation uses a recursive method for calculating the transmission probability through the dielectric stack structure. The physical model was used to fit with capacitance–voltage and Jg–Vg measurements on MIS devices with different single-layer dielectric and multilayered dielectric stack structures. The simulation of the Jg–Vg characteristics of a layered-barrier structure of HfO2/Al2O3/HfO2, which can be potentially applied as the tunnel dielectric of nonvolatile memory devices, is also presented and compared with results from metal–oxide–semiconductor devices with a single layer of SiO2 or HfO2 as gate dielectric. It was found that the layered-barrier structure has the steepest Jg–Vg characteristics of the three structures with identical equivalent-oxide thickness. This results in a small ratio of program voltage to retention voltage for the layered-barrier structure, which makes it attractive for nonvolatile memory application. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

In this article, we show the structural and electrical characterization results on aluminum gate/ zirconium dioxide/n-type silicon (Al/ZrO[sub 2]/n-Si) metal-insulator-semiconductor (MIS) devices with equivalent-oxide thickness (EOT) of ∼2.5 nm. About 60% of the devices fabricated with the optimized process conditions showed leakage current density of less than 2 × 10[sup -5] A/cm² at 1 V accumulation bias, which is lower than devices with silicon dioxide as a gate dielectric of similar EOT. Transmission electron microscopy images showed a ∼1.7-nm-thick interfacial layer (possibly zirconium silicate) and a ∼13-nm-thick bulk ZrO[sub 2] layer for the sputter-deposited high-k film. The difference in the dc leakage current of individual devices is due to the varying degrees of crystallization of the bulk ZrO[sub 2] layer, and not related to the interface state density. It was found that the interfacial layer between the bulk ZrO[sub 2] and the silicon substrate plays an important role in determining the conduction mechanism through the high-k MIS structure. The Frenkel-Poole emission mechanism was found to fit the measured J[sub g]-V[sub g] data between electric fields of 2.0 and 3.2 MV/cm in the interfacial layer (corresponding to 0.7 < V[sub g] < 2 V). The electric field in the interfacial layer is generally larger than that in the bulk ZrO[sub 2]. The injecting field at the cathode, or the n-type silicon substrate in this case, depends on the electric field in the interfacial layer as this is directly in contact with the silicon substrate. [ABSTRACT FROM AUTHOR]

The incidence of synchronous lung tumors is rare, as reported in various clinical series, ranging from 0.2% to 8%. Most reported cases of synchronous tumors were shown to have the same histologic types of lung cancer. Among possible combinations, squamous cell carcinoma was by far the most common. Primary pulmonary lymphoma (PPL) is very rare in clinics accounting for only 0.5-1% of primary lung tumors. There is no report about synchronous primary pulmonary adenocarcinoma presenting with lung lymphoma. It can be easily misdiagnosed or missed. Although the treatment of PPL and synchronous pulmonary tumors has controversial, surgery with/without postoperative adjuvant radio-chemotherapy are used for most patients in present. We describe a case of synchronous primary lung tumors presenting with lymphoma and adenocarcinoma, in which expression of the cell surface antigens were evaluated immunohistochemically. By taking into consideration of the reported experiences, the author discusses the clinical features, prognostic criteria and therapeutic management of synchronous lung cancer and PPL. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the effects of recombinant activated coagulation factor VII (rFVIIa) on apoptosis and the expressions of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) in rats with intracerebral hemorrhage (ICH). MATERIALS AND METHODS: A total of 90 8-week-old male Sprague-Dawley (SD) rats with similar weight were selected and randomly divided into normal group (n=30), ICH control group (n=30), and rFVIIa treatment group (n=30). Five days later, hematoxylin-eosin (HE) staining was applied to observe pathological changes in rat brain in three groups. Cell apoptosis in rat brain was detected at 6 h, 12 h, 24 h, 48 h, 72 h, and 120 h, respectively. The relative expression levels of Bcl-2 and Bax in brain tissues were measured via fluorescence quantitative Polymerase Chain Reaction (qPCR) and Western blotting, respectively. RESULTS: Compared with those in ICH control group, rats in rFVIIa treatment group had fewer degenerated and necrotic nerve cells and milder pathological changes in the marginal zone. The number of apoptotic cells in ICH control group and rFVIIa group was gradually increased in a time-dependent manner, and achieved the peak at 72 h. The number of apoptotic cells in treatment group was significantly lower than that in ICH control group after 24 h (p<0.05). Both fluorescence qPCR and Western blotting results proved that in comparison with ICH control group, rFVIIa group had a higher relative expression level of Bcl-2 (p<0.05) and a lower expression level of Bax (p<0.05). CONCLUSIONS: Apoptosis mechanism may be involved in secondary brain injury after ICH. RFVIIa may have an important protective effect on neuronal injury after ICH by promoting the expression of Bcl-2 and inhibiting the expression of Bax protein. [ABSTRACT FROM AUTHOR]

In order to meet the heating requirement of EAST tokamak, ion cyclotron range of frequency (ICRF) heating is utilized as one of the main auxiliary heating methods, which plays an important role in coupling radio frequency (RF) power into the plasma. As a member of plasma facing components, ICRF antenna suffers the plasma radiation as well which is one of the causes of the thermal load on the antenna. Plasma radiation and RF thermal load during the operation of ICRF and thermal load caused by HALO current during vertical displacement event will contribute together to a huge thermal load on the surface of the antenna and consequently the structural stability and reliability of ICRF antenna will be affected. Therefore, cooling channels is needed to remove heat on the ICRF antenna. In this paper, cooling channels for straps of ICRF antenna are designed based on the thermal load on the antenna, and thermal-structural analysis of straps with cooling channels is also carried out by the finite-element method. [ABSTRACT FROM AUTHOR]

The Monkhorst–Pack scheme is applied in Phys. Chem. Chem. Phys., 2021, 23, 6717 to study superconductivity in transition metallic hydrides, implying that umklapp phonons have been excluded. But in a superconductor scattered electrons should be able to cover the entire Fermi surface so that umklapp phonons must be included. The authors should take care to explain if and how measures were taken to include umklapp phonons for electron–phonon scattering. [ABSTRACT FROM AUTHOR]

The Monkhorst–Pack scheme is applied in a recent article in (2019 Supercond. Sci. Technol. 32 125013) implying exclusion of the umklapp phonons. But in a superconductor scattered electrons can land anywhere on the Fermi surface so that umklapp phonons must be included. The authors should take care to explain if and how the original Monkhorst–Pack scheme was modified to accommodate umklapp phonons for electron-phonon scattering. [ABSTRACT FROM AUTHOR]

Serials of Mn doping by substituting Cd sites on Cu2CdSnSe4 are prepared by the melting method and the spark plasma sintering (SPS) technique to form Cu2Cd1-xMnxSnSe4. Our experimental and theoretical studies show that the moderate Mn doping by substituting Cd sites is an effective method to improve the thermoelectric performance of Cu2CdSnSe4. The electrical resistivity is decreased by about a factor of 4 at 723 K after replacing Cd with Mn, but the seebeck coefficient decreases only slightly from 356 to 289 μV/K, resulting in the significant increase of the power factor. Although the thermal conductivity increases with the doping content of Mn, the figure of merit (ZT) is still increased from 0.06 (x = 0) to 0.16 (x = 0.10) at 723 K, by a factor of 2.6. To explore the mechanisms behind the experimental results, we have performed an ab initio study on the Mn doping effect and find that the Fermi level of Cu2CdSnSe4 is shifted downward to the valence band, thus improving the hole concentration and enhancing the electrical conductivity at the low level doping content. Optimizing the synthesis process and scaling Cu2Cd1-xMnxSnSe4 to nanoparticles may further improve the ZT value significantly by improving the electrical conductivity and enhancing the phonon scattering to decrease the thermal conductivity. [ABSTRACT FROM AUTHOR]

A scalable active compensatory sub-circuit that focuses on and improves the accuracy of the GaN HEMT large signal model is proposed in this letter. Zero error between the simulated and measured dc $I$– $V$ curves is obtained. Combining empirical and table-based models, time-consuming procedures for parameters extraction and optimizing can be simplified. With a normalizing factor introduced, the scaling of the model is accomplished. The validity of the proposed model is investigated experimentally. This model can be applied for devices with different designs and technology. [ABSTRACT FROM PUBLISHER]

ABSTRACT Blue-shelled eggs are gaining popularity as the consumption demand diversifies in some countries. This study was carried out to investigate the laying performance and egg quality of the blue-shelled egg layers as well as the effects of different housing systems on egg production and quality traits. One thousand pullets from Dongxiang blue-shelled layers were divided into 2 even groups and kept in different housing systems (outdoor vs. cage). Daily laying performance was recorded from 20 to 60 wk of age. External and internal egg quality traits were examined at 26, 34, 42, and 50 wk. Yolk cholesterol concentration and whole egg cholesterol content were measured at 40 wk of age. Average laying rate from 20 to 60 wk for the cage (54.7%) was significantly higher than that of outdoor layers (39.3%). Among all of the egg quality traits, only eggshell color was affected by housing system. Interaction between housing system and layer age was found in egg weight, eggshell color, eggshell ratio, yolk color, and yolk weight. Meanwhile, cholesterol concentration in yolk was 8.64 ± 0.40 mg/g in the outdoor eggs, which was significantly lower than that of eggs from the cage birds (10.32 ± 0.48 mg/g; P < 0.05). Whole egg cholesterol content in the outdoor eggs (125.23 ± 6.32 mg/egg) was also significantly lower than that of eggs from the caged layers (158.01 ± 8.62 mg/egg). The results demonstrated that blue-shelled layers have lower productivity in the outdoor system than in the cage system. Blue-shelled layers have lower egg weight, larger yolk proportion, and lower cholesterol content compared with commercial layers. In a proper marketing system, lower productivity could be balanced by a higher price for the better quality of blue-shelled eggs. [ABSTRACT FROM AUTHOR]

As we have demonstrated, the AGIF procedure allows designers to create accurate and efficient full-wave EM structures directly from IC layouts in semiconductor processes. The template based procedure also allows batch conversion and EM-simulation of structures directly from GDS II. It makes it possible to apply full-wave EM simulation to large number of structures in industrial design environment. The precision and reliability of the CMOS manufacturing, the accuracy of full-wave EM tools, and the effectiveness of automatic conversion in AGIF are verified. [ABSTRACT FROM PUBLISHER]

The semen quality factor (SQF) takes into account 3 semen parameters as a means of predicting semen fertilizing ability: semen volume, semen concentration, and the percentage of live and morphologically normal spermatozoa. The objective of this study was to test the suitability of the SQF as an indicator of fertility for geese. Twenty-one ganders were divided into 3 groups based on their individual SQF values, and semen was pooled within each group. A fourth semen group was generated by diluting semen from the highest SQF group with 2 vol of diluent. Pooled semen was inseminated into 30 geese per treatment. Relationships between SQF and fertility were evaluated. Testosterone and estradiol levels in seminal plasma were determined by competitive immunoassays. The SQF values of the 4 diluted semen groups were 19.3, 11.3, 9.5, and 13.1, and the corresponding fertility values, determined by candling, were 83.9, 65.6, 56.8, and 74.3%, respectively. The correlation coefficient between SQF and fertility was 0.985 (P < 0.01), indicating that the SQF can be used as a good indicator of fertility for geese. The SQF values correlated well with the ratio of testosterone to estradiol in seminal plasma (r = 0.48, P < 0.05), which could also be a diagnostic tool for evaluating the reproductive potential of individual ganders. [ABSTRACT FROM AUTHOR]

Sex-linked dwarf chickens caused by the mutation of the growth hormone receptor gene are characterized by normal growth hormone (GH), very low insulin-like growth factor I (IGF-I) level in the blood, and reduced growth. It has been demonstrated that the sex-linked dwarfing gene has negative effects on female reproduction. hi the current study, dwarf cocks and their phenotypic normal siblings were used to investigate the effects of dwarf gene on male reproduction. Dwarf cocks grew slower than the normal cocks did, and at 20 wk of age, their BW were 36.4% smaller. However, all parameters for semen quality, including volume, sperm concentration, viability, mobility, pH, and percentage of abnormal sperms, examined at 30 wk of age showed no significant difference between normal and dwarf cocks. The fertility of dwarf cocks was 95.2%, and the normal was 92.4%. The concentrations of GH and IGF-I in serum and seminal plasma were measured with RIA and ELISA, respectively. The serum GH in the dwarf cocks was significantly higher than their normal siblings (P < 0.05), whereas the serum IGF-I in the dwarf cocks was very low. However, the concentration of seminal IGF-I in dwarf cocks was similar to that of their normal siblings, indicating that IGF-I might be produced and acted independently in testis. In conclusion, the deficiency in GH receptor did not affect the male reproduction in dwarf chickens, and the fertility of dwarf cocks could be satisfactory for production when artificial insemination was adopted. [ABSTRACT FROM AUTHOR]

Stress concentration damage is one of the most troublesome problems in practical engineering structures. In order to reduce damage, it is very important to determine stress concentration factors accurately. An artificial neural network (NN) technique has been used in this article to simulate the relationship between basic random variables and stress concentration factors, and the explicit expression of the stress concentration factors can be obtained directly. The expression of the stress concentration and the reliability theory have been combined to solve the structural reliability problems; then, the corresponding methods of reliability analysis and optimization design have been presented. [ABSTRACT FROM AUTHOR]

Techniques from the perturbation method, the Edgeworth series, the reliability-based design theory, and the sensitivity analysis approach are employed to present a practical and efficient method for the reliability sensitivity of automobile components with arbitrary distribution parameters. On the condition of first four moments of original random variables known, the reliability sensitivity theory and case studies are researched. The respective program can be used to obtain the reliability sensitivity of automobile components with arbitrary distribution parameters accurately and quickly. [ABSTRACT FROM AUTHOR]

A mixed-potential, spatial-domain integral equation approach is used to model the coupling and junction effects when microstrip structures in two different layers of a common substrate are crossing each other. A Galerkin method, together with the so-culled pseudo-mesh current distribution for the basis functions, is then applied to accurately characterize multiport junctions. As an example, a four-port crossover of two microstrip transmission lines is characterized in terms of the S-parameters. [ABSTRACT FROM AUTHOR]

Multiferroic La0.1Bi0.9FeO3 (LBFO) ceramics with high resistivity were synthesized by using a modified rapid thermal process. The LBFO ceramics show very low leakage and low dielectric loss. Well saturated ferroelectric hysteresis loops and polarization switching currents have been observed. For a maximum applied electric field of 145 kV/cm, the remanent polarization is 17.8 μC/cm2 and the coercive filed is 75 kV/cm. The dominant conduction mechanism in the LBFO ceramics has been found to be the space-charge-limited current mechanism rather than the thermal excitation mechanism. Electrical reliability related to the fatigue and polarization retention of the LBFO ceramics has also been discussed with the leakage mechanisms. [ABSTRACT FROM AUTHOR]

Major histocompatibility complex has previously been shown to influence the resistance of chicken to Marek's disease virus (MDV). However, little is known about expression of other genes in the MHC-I and II pathway after MDV infection. This study aimed at investigating 8 immune-related genes in the MHC core region that affects host responses to MDV. Spleens of infected and age-matched uninfected chickens were removed at 4, 7, 14, 21, and 28 d postinfection for gene expression detection using real-time PCR. Different expression patterns of MHC-I and II pathway genes were observed in the spleen. In the MHC-I pathway, the expression of transporter of antigen protein 1 (TAP1), transporter of antigen protein 2 (TAP2), and transporter of antigen protein-binding protein (TAPBP) genes was significantly increased in the spleen of MDV-infected than that of uninfected chickens. It indicated that host antivirtis responses were generated to enhance antigen presentation. However, MHC-II pathway genes showed contrarary trends. Classical MHC-II β chain major gene (BLB2) and nonclassical class II genes [DM a chain gene (IpMA), DM β chain gene-i (DMB1), and DM β chain gene-2 (DMB2)] had consistent lower transcripts in spleens of MDV-infected than that of uninfected chicken's, which reflected that MDV interfered with multiple components of the MHC-II pathway. Overall, expression of most genes in the MHC core region was altered; moreover, the genes in endogenous and exogenous antigen presentation pathways had different expression patterns in the spleen after MDV infection. [ABSTRACT FROM AUTHOR]

The tyrosinase (TYR) and melanocortin 1 receptor (MC1R) genes have been accepted as major genes involved in the plumage pigmentation of chickens. The co-segregation of plumage coloration and sequence polymorphism in TYR and MC1R genes were investigated using an intercross between black and white plumage color types of the Dongxiang blue-shelled chicken. Profiles of plumage color changing and genes expression levels of TYR and MC1R were observed from hatch to 112 d of age using quantitative real-time reverse transcription-PCR. Intercrossed offspring were classified by phenotypes of plumage colors. The phenotypes of black and amber chicks with genotypes of E̱C̱ exhibited a black feather pattern, whereas white, gray, and buff chicks with genotypes of E̱cc and eecc belonged to the white feather pattern. Although TYR in cooperation with MC1R determined the coloration feather patterns, the different phenotypes did not correspond completely with the genotypes. During the period studied, plumage phenotype changed dramatically, and the buff and gray down were gradually replaced by whiteness feathers. Real-time reverse transcriptionPCR studies showed that 1) expression levels of TYR declined dramatically with age, and expression at hatch was highest (P < 0.01) during the ages studied; 2) expression level of MC1R was higher at 28 d than at younger and older ages; and 3) expression of TYR in chickens carrying E/E and E/e alleles on MC1R loci were higher than those carrying e/e alleles from hatch to 28 d. [ABSTRACT FROM AUTHOR]

Toll-like receptors (TLR) are trans-membrane sensors recognizing invading microbes. Toll-like receptors play a central role in initiating immune responses against several pathogens. In this study, we investigated the response of TLR and downstream genes to Marek's disease virus (MDV) infection. Forty 1-d-old chicks were randomly divided into 2 groups, with 20 chicks infected with MDV and 20 chicks mock-infected. Four chickens were euthanized respectively from infected and age-matched noninfected groups at 4, 7, 14, 21. and 28 d postinfection (dpi). Bursas, spleens, and thymuses were removed. The differential expression of TLR genes, including TLR3, TLR5, TLR7, TLR15, and TLR21, and downstream genes of TLR 7, including MyD88, TRAF3, TRAF6, IFNA, IFNB, and IL6, in lymphoid tissues of MDV-infected and noninfected chickens was determined by real-time PCR. The results showed that the change of TLR genes was different in 3 lymphoid tissues. Expression of TLR7 and MyD88 was upregulated at 14 dpi and downregulated at 28 dpi in MDV-infected compared with noninfected spleens. The TRAF6 and IFNB were upregulated, and TRAF3, IFNA, and IL6 genes showed increasing trends in MDVinfected compared with noninfected spleens at 14 dpi. The expression of TLR3 and TLR 15 genes was downregulated in MDV-infected compared with noninfected spleens at 28 dpi. The results indicated that TLR7 and its downstream genes were a response to MDV infection at 14 dpi. However, the function of TLR was impaired when the infection entered the tumor transformation phase. In bursas, TLR3 and TLR 15 genes were upregulated at 7 and 4 dpi, respectively. It indicated that TLR3 and TLR 15 might be involved in response to MDV infection in bursa at early phases. However, no differential expression of TLR genes was observed between MDV-infected and noninfected thymuses, which indicated that the thymus had little response to MDV infection mediated by TLR. [ABSTRACT FROM AUTHOR]

Some members of the low-density lipoprotein receptor (LDLR) family play important roles in the regulation of lipoprotein metabolism and egg quality traits. Low-density lipoprotein receptor-related protein 2 (LRP2) gene belongs to the LDLR super family, and widely expresses in many tissues. This work identified and genotyped 1 single-nucleotide polymorphism. (SNP), T14347C, at 3'-UTR of the LRP2 using matrixassisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS), and analyzed the effects of the SNP (T14347C) on egg-quality traits in 544 dwarf hens from 44 sire families. Frequencies of this SNP in the studied population did not agree with the Hardy-Weinberg equilibrium (P < 0.0001). Egg weight, albumen weight, albumen height, and albumen ratio of the TT genotype were significantly higher than those of the CC genotype (P < 0.05), whereas eggshell ratio of the TT genotype was significantly lower than that of the CC genotype (P < 0.05). The relative expression level of the LRP~2 gene in the magnum was determined by real-time quantitative PCR. The gene expression of genotype CC individuals was significantly higher than that of TT and CT birds (P < 0.05). By combining both genetic effects and expression analyses results, we propose that the LRP2 gene is a good candidate gene, exhibiting a key role in albumen formation processes. [ABSTRACT FROM AUTHOR]

Numerical simulations are performed on the behaviour of agglomerates of nanoparticles in bubbling gas fluidized beds and spouted beds—systems that are widely used in handling and processing particulate solids in various industrial sectors including biomaterials, foods and pharmaceuticals. An Eulerian two-fluid approach is used and the cohesive force between particles is considered. An empirical expression for the solids pressure of agglomerates is used (Jung and Gidaspow, 2002). The interaction between gas and agglomerates is considered with an agglomerate-based approach. Simulated results show that the fluidized bed has a very high expansion ratio with no distinct bubbles in the bubbling fluidized bed. In the spouted bed, however, the concentration of agglomerates is nearly homogeneous in both the dilute and transitional zones. The velocity of agglomerates is found to be higher than that in the annulus region, whereas the concentration distribution shows an opposite trend with a nearly closing packing of agglomerates in the annulus region. A high spouting gas velocity is shown to be required to fluidize agglomerates in the spouted bed. Comparisons of the modelling results are also made with limited experimental results. [ABSTRACT FROM AUTHOR]