Structural stability, elasticity, thermodynamics, and electronic structures of L12-type Ni3X (X = Al, Ti, V, Nb) phases under external pressure condition.

In this paper, the effect of pressure on the structural stability, elasticity, thermodynamics, and associated electronic structure of L12-type Ni3X (X = Al, Ti, V, Nb) phases is investigated using a first-principles approach. It is shown that pressure leads to volume compression of the Ni3X phase and reduction of the lattice parameters. The increase of pressure promotes the increase of elastic constants, bulk modulus, shear modulus, and Young's modulus. And there is an extremely strong linear correlation between the pressure and the elastic constants. The calculated elastic constants indicate that the pressure leads to strong mechanical stability and ductility of the Ni3X phase. Mechanical anisotropy of the Ni3X phase also increases with increasing pressure. The electronic analysis shows that the increase in pressure leads to enhanced Ni-d-orbitals and X-d-orbitals hybridization and increased electron transfer. The order in terms of electron accumulation intensity is Ni3Ti > Ni3Nb > Ni3V > Ni3Al. It is more directly reflected in the charge density difference diagram. This is in agreement with the results of the enthalpy of formation (ΔH) and Debye temperature (ΘD) analysis.

[A preliminary investigation on a deep learning convolutional neural networks based pulmonary tuberculosis CT diagnostic model].

Objective: To evaluate the clinical value of a pulmonary tuberculosis CT diagnostic model based on deep learning convolutional neural networks (CNN). Methods: From March 2017 to March 2018,a total of 1 764 patients with positive sputum for tuberculous bacterium and had received high-resolution chest CT scan in radiology department of Hebei province chest hospital were enrolled. Among them, 937 were male, and 827 were female, aging from 17-73 years (average 38.4). A total of 20 139 CT images (17 kinds of image features) classified by 4 radiologists were used as training dataset to create a tuberculosis CT CNN diagnostic model. The top 5 image features in training set were: infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion. A total of 302 images were randomly selected from the marked images as testing dataset. The diagnosis of 2 senior radiologists was taken as "golden standard". The differences of sensitivity and accuracy in CT diagnosis between the CNN diagnostic model and the radiologists were compared. The classification error types and numbers of the CNN diagnostic model were recorded. FROC(free response operating characteristic curve)curve was drawn and the highest diagnostic efficiency of the model was measured. Results: The diagnostic accuracy of infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion by the CNN diagnostic model were 95.33%(10 982/11 520), 73.68%(2 151/2 920), 73.07%(1 128/1544), 83.33%(1 020/1225)and 94.11%(814/865), respectively. The overall diagnostic sensitivity and accuracy of the CNN model were 95.49%(339/355)and 90.40%(339/375), respectively, and the corresponding values ​​of radiologists were 93.80%(348/371)and 92.80%(348/375), respectively, and there was no statistical difference between the CNN model and the radiologists(sensitivity χ2=1.022,P=0.312;accuracy χ2=1.404,P=0.236). FROC curve showed that when sensitivity of the CNN model was 78% and FPI value was 2.48, it reached the highest diagnostic efficiency. The classification error of CNN diagnostic models was mainly confusion of fiber stripe components, cavitary pulmonary tuberculosis, caseous pneumonia and infiltrative pulmonary tuberculosis. Conclusions: The CNN-based pulmonary tuberculosis CT diagnostic model exhibited high sensitivity and accuracy (95.49% and 90.40% respectively). It could assist radiologists in CT diagnosis of pulmonary tuberculosis and deserve further clinical application.

Transcriptome Sequencing Analysis of Chrysomyia Megacephala Pupae in Different Growing Periods.

ABSTRACT: Objective To study the growth regulation, environmental adaption and epigenetic regulation of Chrysomyia Megacephala pupae, in order to obtain the transcriptome data of Chrysomyia Megacephala in different growing periods, and lay the foundation for forensic application. Methods The Chrysomyia Megacephala was cultivated and after pupation, 3 pupae were collected every 24 h from pupation to emergence, and stored at -80 ℃ for later use. High-throughput sequencing was performed by Illumina Hiseq 4000 and Unigenes were obtained. The Unigenes were compared by comparison tool BLAST from NCBI in databases such as NR, STRING, SWISS-PROT （including Pfam）, GO, COG, KEGG in order to obtain the corresponding annotation information. The expression amount of Unigenes obtained by sequencing in Chrysomyia Megacephala in six different growing periods was calculated by FPKM method, and the discrepant genes were screened according to the following standards： the log2 multiple absolute value of FPKM expression amount between two different growing periods must be larger than 1 （log2|FC|>1）, and the false discovery rate must be less than 0.05. Results When the mean temperature was 25.6 ℃, Chrysomyia Megacephala emerged 6 d after they pupated. A total of 43 408 pieces of Unigenes were obtained and their mean length was 905 bp, of which 32 500, 18 720, 13 542, 9 191 and 18 720 pieces were annotated by NR, SWISS-PORT, Pfam, STRING and KEGG databases. According to the discrepant gene analysis of pupae in two different growing periods, the number of genes with variants ranged from 801 to 5 307, and the total number of discrepant genes was 45 676. Conclusion The gene expressions of the transcriptome data of Chrysomyia Megacephala pupae in different growing periods are different. The results provided a good foundation for further research on the transcriptome changes in each period of the pupae of sarcosaprophagous flies and provided the basis for exploring the genes associated with the growth of Chrysomyia Megacephala pupae.

PASP: Property analysis and simulation package for materials.

We have developed a software package, namely, PASP (Property Analysis and Simulation Package for materials), to analyze the structural, electronic, magnetic, and thermodynamic properties of complex condensed matter systems. Our package integrates several functionalities including symmetry analysis, global structure searching methods, effective Hamiltonian methods, and Monte Carlo simulation methods. In conjunction with first-principles calculations, PASP has been successfully applied to diverse physical systems. In this paper, we give a brief introduction to its main features and underlying theoretical formulism. Some typical applications are provided to demonstrate the usefulness, high efficiency, and reliability of PASP. We expect that further developments will make PASP a general-purpose tool for material simulation and property calculation of condensed matters.

[Study on preparation of 3D printing degradable tissue engineering ossicles].

Objective: In combination with 3D printing technology and degradable composite materials, to discuss the preparation method of tissue engineering ossicles for middle ear hearing reconstruction. Methods: Domestic polymer (polylactic acid-glycolic acid copolymer, PLGA) and degradable ceramic material (ß-tricalcium phosphate, ß-TCP) were selected and prepared by low temperature deposition method according to the design ratio to Program according to the outline design code of the required scaffold to generate appropriate print files, and then the self-developed low-temperature deposition printing device was used to prepare tissue-engineered osseous scaffolds in accordance with the print files in a low-temperature environment. The scaffolds was freeze-dried and sterilized for later use after printing. Light microscopy and scanning electron microscopy were used to observe the apparent characteristics and internal structure of the scaffolds and to check its pore size, porosity and mechanical properties. Results: After printing, a degradable scaffold was obtained. Under the optical microscope, it was a small cylindrical shape with a diameter of 1.5 mm and a length of 6.0 mm, and its surface had micropores. The degradable scaffold had a horizontal and vertical interlaced warp and weft structure, the wire spacing was 1.2 mm, and the pores were connected to each other. The surface could see circular or quadrangular pores with a pore size of about 100-400 µm. The diameter of the inter-pore cross-linked channels was about 50 µm and the diameter of the surrounding circular micropores was about 10-40 µm. ß-TCP particles with a size of about 700 nm were attached to the surface of the PLGA material. The average porosity of the whole scaffolds was (83.43±0.01)%, and the content of BMP-2 loaded was about 0.7 µg/mm(3). After freeze-drying, the mechanical strength of the scaffold was moderate, and there was no obvious deformation during stretching and compression, which met the mechanical requirements of tissue engineering ossicles. Conclusions: Using the low-temperature deposition printing method and strictly controlled processes and conditions, a polymer-degradable ceramic ossicle tissue engineering scaffold can be prepared for implantation experiments. The scaffold has suitable porosity and mechanical properties, and can be loaded with osteoinductive factors.

[Polymorphism and Forensic Application of 11 Y-SNP in Guizhou Shui Ethnic Group].

ABSTRACT: Objective To investigate the frequency distribution features of 11 Y-SNP of Guizhou Shui ethnic group, explore its genetic relationship with other ethnic groups and evaluate its forensic application value. Methods Multiplex amplification of the 11 Y-SNP of samples of 180 unrelated male individuals from Guizhou Shui ethnic group was performed with microsequencing technique. The frequency of haplogroup was calculated by direct counting method, and principal component analysis （PCA） of Guizhou Shui ethnic group and reference ethnic groups was performed by using Multi-variate statistical package （MVSP）. The Fst genetic distance between Guizhou Shui ethnic group and other ethnic groups was calculated with Arlequin v3.5. The phylogenetic tree was established with MEGA 4.0 software according to the Fst value. Results Six types of Y chromosome haplogroups were observed in total. Among which, the distribution frequency of O-M175 haplogroup was the highest （71.11%）, followed by C-M130 （25.00%）, and D-M174 （3.89%）. O1b-M268 （31.11%） and O2a2-IMS-JST021354 （28.33%） had a relatively high distribution frequency in O haplogroup. The paternal relationship between Guizhou Shui ethnic group and Guizhou Gelao ethnic group in the same language group was the closest. Conclusion The distribution of Y-SNP haplogroup of the Shui ethnic group in Guizhou has certain specificity, which can provide basic data for forensic biogeographic inference.

First Measurement of the Total Neutron Cross Section on Argon between 100 and 800 MeV.

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.

[Effect of Rab11 gene expression on the invasion and migration of cervical cancer cell line SiHa in hypoxia].

Objective: To explore the expression of Ras-related protein 11 (Rab11) in hypoxia, the effect of Rab11 on the invasion and migration of cervical cancer cell line SiHa and its possible mechanism. Methods: SiHa cells were divided into 4 groups, the normoxic blank group (normal culture in normoxia), the hypoxic blank group (normal culture in hypoxia), the negative control group [transfection of negative control small interfering RNA (siRNA) in hypoxia], the Rab11-siRNA group (transfection of Rab11 siRNA in hypoxia). Western blot was used to examine the expression of Rab11, integrin α5, integrin ß3, phosphorylated focal adhesion kinase (p-FAK), phosphorylated phosphatidylinositol 3 kinase (p-PI3K) protein, together with the expression of Ras correlative C3 creotoxin substrate 1 (Rac1), which was critical in regulating cell invasion. The mRNA expression of Rab11 in the 4 groups was detected by realtime-qPCR. The cell invasion was detected by matrigel assay, while the cell migration was detected by transwell assay. Immunofluorescence was used to identify intracellular location of Rac1 in SiHa cell. Results: (1) The expression of Rab11, intergrin α5, intergrin ß3, p-FAK, p-PI3K and Rac1 in the normoxic blank group were 0.56±0.04, 0.33±0.03, 0.32±0.03, 0.36±0.03, 0.35±0.03 and 0.47±0.03, respectively. In the hypoxic blank group, they were 0.73±0.03, 0.74±0.03, 0.61±0.03, 0.62±0.03, 0.60±0.03 and 0.73±0.03, respectively. In the negative control group, their expressions were 0.72±0.03, 0.73±0.03, 0.59±0.03, 0.61±0.03, 0.59±0.03 and 0.72±0.03, respectively. While in the Rab11-siRNA group, they were 0.44±0.03, 0.30±0.03, 0.29±0.03, 0.30±0.03, 0.30±0.03 and 0.34±0.04, respectively. The expressions of Rab11, α5, ß3, p-FAK, p-PI3K and Rac1 were significantly higher in the hypoxic blank group than in the normoxic blank group (P<0.05), and were significantly lower in the Rab11-siRNA group than in the hypoxic blank group and the negative control group (P<0.05). (2) The expressions of Rab11-mRNA were 1.000±0.000, 1.454±0.114, 1.442±0.101, 0.570± 0.046 in the normoxic blank group, the hypoxic blank group, the negative control group and the Rab11-siRNA group, respectively. It was significantly higher in the hypoxic blank group than in the normoxic blank group (P<0.05), and was significantly lower in the Rab11-siRNA group than in the hypoxic blank group and the negative control group (P<0.05). (3) By Matrigel, the invasion cell number in the normoxic blank group, the hypoxic blank group,the negative control group and the Rab11-siRNA group were 65±12, 106±16, 104± 17 and 50±11, respectively. The invasion capacity was significantly higher in the hypoxic blank group than in the normoxic blank group (P<0.05), and was significantly lower in the Rab11-siRNA group than in the hypoxic blank group and the negative control group (P<0.05). (4) By transwell assay, the migration cells in the normoxic blank group, the hypoxic blank group, the negative control group and the Rab11-siRNA group were 127±12, 169±15, 161±13 and 77±13, respectively. The capacity of invasion was significantly higher in the hypoxic blank group than in the normoxic blank group (P<0.05), and was significantly lower in the Rab11-siRNA group than in the hypoxic blank group and the negative control group (P<0.05). (5) The immunofluorescence showed that the red fluorescence intensity around nucleus was significantly increased in the normoxic blank group, the hypoxic blank group and the negative control group than in the Rab11-siRNA group. Conclusions: Hypoxia could promote the invasion and migration of SiHa cells. In hypoxia, the down regulation of Rab11 expression could inhibit the invasion and migration of SiHa cells. This might be due to the decreased expression of the intergrin α5, intergrin ß3, p-FAK, p-PI3K and Rac1 protein.

[Pharmacognostical identification of antelope horn(Cornu Saigae Tataricae) and its adulterants].

OBJECTIVE: To provide appropriate information and scientific basis for identifying antelope horn (Saiga tatarica) contained in traditional Chinese patent medicines, and formulate relevant quality criteria through experiments. METHOD: Conducting comparative identification of macroscopic and microscopic characteristics of antelope horn(Saige tatarica) and its adulterants (Procapra gutturosa, Pantholops hodgsoni, Ovis ammon and Capra hircus) and giving a comparative table and an indented key to the main characteristics. RESULT AND CONCLUSION: There are remarkable differences between the authentic product and adulterants in both macroscopic and microscopic characteristics.

Cyclin A and B functions in the early Drosophila embryo.

In eukaryotes, mitotic cyclins localize differently in the cell and regulate different aspects of the cell cycle. We investigated the relationship between subcellular localization of cyclins A and B and their functions in syncytial preblastoderm Drosophila embryos. During early embryonic cycles, cyclin A was always concentrated in the nucleus and present at a low level in the cytoplasm. Cyclin B was predominantly cytoplasmic, and localized within nuclei only during late prophase. Also, cyclin B colocalized with metaphase but not anaphase spindle microtubules. We changed maternal gene doses of cyclins A and B to test their functions in preblastoderm embryos. We observed that increasing doses of cyclin B increased cyclin B-Cdk1 activity, which correlated with shorter microtubules and slower microtubule-dependent nuclear movements. This provides in vivo evidence that cyclin B-Cdk1 regulates microtubule dynamics. In addition, the overall duration of the early nuclear cycles was affected by cyclin A but not cyclin B levels. Taken together, our observations support the hypothesis that cyclin B regulates cytoskeletal changes while cyclin A regulates the nuclear cycles. Varying the relative levels of cyclins A and B uncoupled the cytoskeletal and nuclear events, so we speculate that a balance of cyclins is necessary for proper coordination during these embryonic cycles.

Altered UV resistance and UV mutational spectrum in repair-proficient murine fibroblasts expressing endonuclease V.

In previously reported studies, we transfected repair-proficient murine fibroblasts with the denV gene of bacteriophage T4 and showed that expression of encoded endonuclease V markedly enhanced cyclobutane pyrimidine dimer (CPD) repair and reduced the frequency of ultraviolet radiation (UV)-induced mutations. In the present studies, we compared the spectra of UV-induced mutations at the hprt locus in denV-transfected and control cells. A significant difference in mutation types was observed. While multiple base deletions and single base insertions were found in denV-transfected but not control cells, multiple tandem and non-tandem point mutations identified in control cells were absent in denV-transfected cells. When we compared colony survival following UV exposure in the two cell lines, it appeared that endonuclease V expression did not enhance UV resistance, instead denV-transfected cells had increased susceptibility to low fluences of UV. The effects of endonuclease V expression on UV resistance and on UV mutational spectrum are likely to be due both to the removal of CPDs and to the novel enzymatic activity of endonuclease V.

Ca2+ binding to occluded sites in the CrATP-ATPase complex of sarcoplasmic reticulum: evidence for two independent high-affinity sites.

Occluded Ca2+ sites in the CrATP-ATPase complex are studied by first forming the complex in the presence of EGTA so that the sites can be occluded while vacant. 45Ca2+ binding to the occluded sites is then studied under equilibrium conditions. Binding curves are produced for two independent Ca2+ sites with Kd(1) = 0.2 microM and Kd(2) = 1.6 microM. When both sites are saturated, only the Ca2+ bound to the lower affinity site can exchange with free Ca2+. On addition of EGTA (15 vs 0.5 mM Ca2+) all bound Ca2+ dissociates, the net dissociation rate of one-half of the Ca2+ being approximately 10-fold greater than that of the other one-half (at 37 degrees C). When Ca2+ is bound only to the higher affinity site, this Ca2+ will exchange slowly if the concentration of free Ca2+ is below the saturation level of the lower affinity site. An ionophore dependency of the rates of binding and dissociation indicates that the access to the sites is through the interior of the vesicle. Solubilization in C12E9 releases the Ca2+ in the higher affinity site. Our observations are consistent with a model of the ATPase where the lower affinity of two transport sites is associated with the interior position (closest to the lumen) in a transmembrane channel. It is further evident that when in the occluded state, the higher affinity site is available without Ca2+ first being bound to the lower affinity site, eliminating cooperativity from the binding mechanism. In turn, this implies a connection between the integrity of the high-affinity binding site and the linking of sections of the catalytic site by CrATP.

Sarcoplasmic reticulum calcium ATPase. Labeling of a putative Mg2+ site by reaction with a carbodiimide and a spin-label.

The sarcoplasmic reticulum Ca(2+)-ATPase loses hydrolytic activity and the ability to be phosphorylated by Pi following incubation with EDC [1-ethyl-3-(3-dimethylaminopropyl)carbodiimide]. 4 nmol of tempamine per mg SR protein can be coupled to either a glu or an asp side chain through the EDC reaction. Mg2+ protects against loss of activity and tempamine labeling with a mid-point of about 3 mM in the absence of Ca2+. This is similar to the Kd for a Mg2+ that serves as a cofactor in enzyme phosphorylation. The Mg2+ protection constant is lowered by an order of magnitude when Ca2+ is bound to the transport sites. It is suggested that control of the Mg2+ binding site affinity may be part of the mechanism of enzyme activation by Ca2+.

Protein sulfhydryls are protected from irreversible oxidation by conversion to mixed disulfides.

Protein mixed thioselenides formed by reaction of sarcoplasmic reticulum (SR) with diselenide biradical spin labels were quantified by ESR. Whereas the reaction of SR membranes with the diselenide spin label led to a large ESR signal of the unbound monoselenide at equilibrium, treatment of the reaction mixture with a few millimolar hydrogen peroxide converted all of the nitroxides to protein-bound thioselenides. This technique of spin-labeling protein thiols avoids the need to remove unreacted spin labels. The bound spin labels were removable by reduction with excess mercaptoethanol, indicating a specific and reversible labeling of protein thiols. SR that had been extensively labeled with the diselenide spin label was resistant to ATPase inactivation by potent oxidants that arise when myoglobin reacts with hydroperoxides. Unmodified SR lost all activity within 10 min of exposure to either 1 mM tert-butyl hydroperoxide in the presence of 200 microM equine myoglobin or to 100 mM hydrogen peroxide in the absence of myoglobin. In both cases the loss of activity could not be reversed by subsequent treatment with mercaptoethanol. On the other hand, membranes that had been extensively treated with the diselenide spin label and were then subjected to these peroxide treatments were fully active after mercaptoethanol-mediated cleavage of the thioselenides. ESR analysis of spin-labeled SR showed no detectable oxidative cleavage of the thioselenide bonds. Sodium dodecyl sulfate gel electrophoresis showed that peroxide-mediated crosslinking of ATPase observed in unmodified SR membranes did not occur in the diselenide-modified SR membranes. Only limited protection was observed when SR pretreated with glutathione disulfide was incubated with hydroperoxides. In this case, however, the degree of protection was greatly increased when the reaction with glutathione disulfide was carried out in the presence of the supernatant of centrifuged rat liver homogenate, consistent with an acceleration of mixed disulfide formation by a factor tentatively identified as thiol transferase. It is concluded that conversion of protein thiol residues to either thioselenides or mixed disulfides confers protection against irreversible peroxide-dependent oxidation. We suggest that mixed disulfide formation by thiol transferase activity may help protect protein thiols from irreversible oxidation by heme-activated hydroperoxides.

The electron spin resonance study on primary photochemical reaction of hematoporphyrin derivative.

The rate of oxygen consumption and the yield of free radical anion of hematoporphyrin derivative (HPD) in aqueous solutions of HPD and pyrocatechol were measured by the probe 2,2,6,6-tetramethyl-4-piperidone-1-oxyl. It has been found that both singlet oxygen and free radical mechanisms exist simultaneously in primary photochemical reactions, and there is a competition between both mechanisms. When the oxygen concentration in solutions comes down to 12-14% of the stanting level, the predominant mechanism can be changed from the singlet oxygen to the free radical. Whether HPD exists in aggregation state is very important to photosensitization mechanisms. In the presence of the aggregation state of HPD, the predominant mechanism is the free radical, and photosensitization effects of HPD are all the better.