脑出血患者肺部感染原因分析及护理

目的探讨脑出血患者医院内肺部感染的危险因素及护理对策。方法回顾性分析2001年1月至2006年9月收治的140例脑出血患者并发肺部感染的状况。结果脑出血患者并发肺部感染以中老年患者多见,其中深昏迷80例、留置胃管患者64例、既往有肺部疾病者32例、呼吸机辅助呼吸17例。结论脑出血并发医院内肺部感染由多种病因所致,多发生在脑出血后2周内,病原体主要为革兰阴性菌,病死率高,应引起临床护理的高度重视。

Robust Delaunay Tetrahedronal Meshing Coupled with Advancing Front Method

A full automatic tetrahedronal mesh generation method for arbitrary 3D domains is described. First, the classic Delaunay method is coupled with simplified advancing front technique (AFT) to obtain the boundary mesh. Then, advancing front high quality point placement is used to generate internal points with optimal positions and a Delaunay method is used to insert them efficiently. Finally, optimization procedures are used for mesh quality improvements. Several application examples are presented to demonstrate the robustness and efficiency of the proposed meshing scheme.

The Impact of the South Asia High Bimodality on the Chemical Composition of the Upper Troposphere and Lower Stratosphere

The South Asia High （SAH） is the dominant feature of the circulation in the upper troposphere and lower stratosphere （UTLS） during the boreal summer, and the upper tropospheric anticyclonic circulation extends into the lower stratosphere. The preferred locations of the center of the SAH occur in two different regions, and the center can be located over the Iranian Plateau or over the Tibetan Plateau. This bimodality has an impact on the distribution of chemical constituents in the UTLS region. We analyzed water vapor （H20）, carbon monoxide （CO）, and ozone （03） data derived from the Aura Microwave Limb Sounder （MLS） and total column ozone data from the Ozone Monitoring Instrument （OMI）. For the Iranian Plateau mode of the SAH, the tropospheric tracers exhibited a positive anomaly over the Iranian Plateau and a negative anomaly over the Tibetan Plateau, whereas the stratospheric tracer exhibited a negative and a positive anomaly over the Iranian Plateau and the Tibetan Plateau, respectively. For the Tibetan Plateau mode, however, the distribution of the anomaly was the reverse of that found for the chemical species in the UTLS region. Furthermore, the locations of the extrema within the anomaly seemed to differ across chemical species. The anomaly extrema for H20 occurred in the vicinity of the SAH ridgeline, whereas CO and O3 exhibited a northward shift of 4-8 degrees. These impacts of the variation in the SAH on the chemical constitutes in the UTLS region can be attributed in part to the dynamical structure delineated by the tropopause field and the temperature field at 100 hPa.

Preparation of anti-mouse caspase-12 mRNA hammerhead ribozyme and identification of its activity in vitro

AIM:To prepare and identify specific anti-mouse caspase-12 hammerhead ribozymes in vitro, in order to select a more effective ribozyme against mouse caspase-12 as a potential tool to rescue cells from endoplasmic reticulum stress induced apoptosis. METHODS: Two hammerhead ribozymes directed separately against 138 and 218 site of nucleotide of mouse caspase-12 mRNA were designed by computer software, and their DNA sequences were synthesized. The synthesized ribozymes were cloned into an eukaryotic expression vector-neorpBSKU6 and embedded in U6 SnRNA context for further study. Mouse caspase-12 gene segment was cloned into PGEM-T vector under the control of T7 RNA polymerase promoter (containing gene sequence from positions nt 41 to nt 894) as target. In vitro transcription both the ribozymes and target utilize T7 promoter. The target was labeled with [α-32P]UTP, while ribozymes were not labeled. After gel purification the RNAs were dissolved in RNase free water. Ribozyme and target were incubated for 90 min at 37 ℃ in reaction buffer (40 mmol/L Tris-HCL, pH 7.5, 10 mmol/L Mg2+). Molar ratio of ribozyme vs target was 30:1. Samples were analyzed on 6% PAGE (containing 8 mol/L urea). RESULTS: Both caspase-12 and ribozyme gene sequences were successfully cloned into expression vector confirmed by sequencing. Ribozymes and caspase-12 mRNA were obtained by in vitro transcription. Cleavage experiment showed that in a physiological similar condition (37 ℃, pH 7.5), Rz138 and Rz218 both cleaved targets at predicted sites, for Rz138 the cleavage efficiency was about 100%, for Rz218 the value was 36.66%. CONCLUSION: Rzl38 prepared in vitro can site specific cleave mouse caspase-12 mRNA with an excellent efficiency. It shows a potential to suppress the expression of caspase-12 in vivo, thus provided a new way to protect cells from ER stress induced apoptosis.

The Use of Data Mining Techniques in Rockburst Risk Assessment

Rockburst is an important phenomenon that has affected many deep underground mines around the world. An understanding of this phenomenon is relevant to the management of such events, which can lead to saving both costs and lives. Laboratory experiments are one way to obtain a deeper and better understanding of the mechanisms of rockburst. In a previous study by these authors, a database of rockburst laboratory tests was created; in addition, with the use of data mining （DM） techniques, models to predict rockburst maximum stress and rockburst risk indexes were developed. In this paper, we focus on the analysis of a database of in situ cases of rockburst in order to build influence diagrams, list the factors that interact in the occurrence of rockburst, and understand the relationships between these factors. The in situ rockburst database was further analyzed using different DM techniques ranging from artificial neural networks （ANNs） to naive Bayesian classifiers. The aim was to predict the type of rockburst-that is, the rockburst level-based on geologic and construction characteristics of the mine or tunnel. Conclusions are drawn at the end of the paper.

Study on Classification of Personality-Based Brand Archetype from the Perspective of Internet

Due to the rapid development,Internet has become the main field for brand building.Under this circumstance,the image of the brand is always consistent with the consumers' perception.Therefore,this study uses the method of text mining of search engine to explore the categories of brand archetype based on Brand Personality Theory from the perspective of Internet.The results find that 12 brand archetypes,including caregiver,sage,hero,innocent,dominator,creator,vitality,explorer,stylish woman,lover,cooperator,and vogue gentleman,have a high degree explanation.Deeper study uses case study to verify the reasonability and effectiveness of the classification standard.

The Glacier Area Changes in the Qangtang Plateau Based on the Multi-temporal Grid Method and its Sensitivity to Climate Change

Glacier area changes in the Qangtang Plateau are analyzed during 1970-2000 using air photos,relevant photogrammetric maps and satellite images based on the multi-temporal grid method.The results indicate that the melting of glaciers accelerated,only a few of glaciers in an advancing state during 1970-2000 in the whole Qangtang Plateau.However,the glaciers seemed still more stable in the study area than in most areas of western China.We estimate that glacier retreat was likely due to air temperature warming during 1970-2000 in the Qangtang Plateau.Furthermore,the functional model of glacier system is applied to study climate sensitivity of glacier area changes,which indicates that glacier lifespan mainly depends on the heating rate,secondly the precipitation,and precipitation increasing can slow down glacier retreat and make glacier lifespan prolonged.

Multi-goal Control of Chaotic Connected Complex Networks

Beam transport network(BTN)with small world(SW)(so-called BTN-SW)and Lorenz chaotic connectednetwork with scale-free(SF)are taken as two typical examples,we proposed a global linear coupling and combined withlocal error feedback methods in sub-networks to realize multi-goal control method of halo and chaos in two networksabove.The simulation results show that the methods above is effective for any chaotic connected networks and has apotential of applications in based-halo-chaos secure communication.

A Non-symmetric Digital Image Secure Communication Scheme Based on Generalized Chaos Synchronization System

Based on a generalized chaos synchronization system and a discrete Sinai map, a non-symmetric true color （RGB） digital image secure communication scheme is proposed. The scheme first changes an ordinary RGB digital image with 8 bits into unrecognizable disorder codes and then transforms the disorder codes into an RGB digital image with 16 bits for transmitting. A receiver uses a non-symmetric key to verify the authentication of the received data origin, and decrypts the ciphertext. The scheme can encrypt and decz：Fpt most formatted digital RGB images recognized by computers, and recover the plaintext almost without any errors. The scheme is suitable to be applied in network image communications. The analysis of the key space, sensitivity of key parameters, and correlation of encrypted images imply that this scheme has sound security.

Efficient Selection of Linearly Independent Atomic Features for Accurate Machine Learning Potentials

Machine learning potentials are promising in atomistic simulations due to their comparable accuracy to first-principles theory but much lower computational cost.However,the reliability,speed,and transferability of atomistic machine learning potentials depend strongly on the way atomic configurations are represented.A wise choice of descriptors used as input for the machine learning program is the key for a successful machine learning representation.Here we develop a simple and efficient strategy to automatically select an optimal set of linearly-independent atomic features out of a large pool of candidates,based on the correlations that are intrinsic to the training data.Through applications to the construction of embedded atom neural network potentials for several benchmark molecules with less redundant linearly-independent embedded density descriptors,we demonstrate the efficiency and accuracy of this new strategy.The proposed algorithm can greatly simplify the initial selection of atomic features and vastly improve the performance of the atomistic machine learning potentials.

Variations in Soil Temperature at BJ Site on the Central Tibetan Plateau

The temporal and spatial variation in soil temperature play a significant role in energy and water cycle between land surface and atmosphere on the Tibetan Plateau.Based on the observed soil temperature data（hourly data from 1 January 2001 to 31 December 2005）obtained by GAME-Tibet,the diurnal,seasonal and interannual variations in soil temperature at BJ site（31.37°N,91.90°E; 4509 m a.s.l.）near Naqu in the central Tibetan Plateau were analyzed.Results showed that the average diurnal variation in soil temperature at 4 and 20 cm depth can be described as sinusoidal curve,which is consistent with the variation of solar radiation. However,the average diurnal variation in soil temperature under 60 cm was very weak.The average diurnal amplitude in soil temperature decreased by the exponential decay function with the increase of soil depth（R2=0.92,p〈0.01）.It is demonstrated that the average diurnal maximum soil temperature decreased by the exponential decay function with the increase of soil depth（R2=0.78,p〈0.01）.In contrast, the average diurnal minimum soil temperature increased by the exponential grow function with increasing of soil depth（R2=0.86,p〈0.01）.There were a linear negative correlation between the average annual maximum Ts and soil depth（R2=0.96, p〈0.01）,a logarithmic function relationship between the average annual minimum soil temperature and soil depth（R2=0.92,p〈0.01）.The average seasonal amplitude in soil temperature followed the exponential decay function with the increase of soil depth（R2=0.98,p〈0.01）.The mean annual soil temperature in each layer indicated a warming trend prominently.During the study period,the mean annual soil temperature at 4,20,40,60,80,100,130, 160,200 and 250 cm depth increased by 0.034,0.041, 0.061,0.056,0.062,0.050,0.057,0.051,0.047 and 0.042℃/a,respectively.

A Survey on Information-Centric Networking: Rationales, Designs and Debates

The basic function of the Internet is to delivery data(what) to serve the needs of all applications. IP names the attachment points(where) to facilitate ubiquitous interconnectivity as the current way to deliver data. The fundamental mismatch between data delivery and naming attachment points leads to a lot of challenges, e.g., mapping from data name to IP address, handling dynamics of underlying topology, scaling up the data distribution, and securing communication, etc. Informationcentric networking(ICN) is proposed to shift the focus of communication paradigm from where to what, by making the named data the first-class citizen in the network, The basic consensus of ICN is to name the data independent from its container(space dimension) and session(time dimension), which breaks the limitation of point-to-point IP semantic. It scales up data distribution by utilizing available resources, and facilitates communication to fit diverse connectivity and heterogeneous networks. However, there are only a few consensuses on the detailed design of ICN, and quite a few different ICN architectures are proposed. This paper reveals the rationales of ICN from the perspective of the Internet evolution, surveys different design choices, and discusses on two debatable topics in ICN, i.e.,self-certifying versus hierarchical names, and edge versus pervasive caching. We hope this survey helps clarify some mis-understandings on ICN and achieve more consensuses.

Logical Design and Control of Network in Local Mine Air-Reversing System

This paper sets up a mathematical model of switching network and switching function by utilizing graph theory to describe the logical function of different paths.The function varies with open and closed states of air doors in a complex mine air sub network, and the computer program for solving the switching function of complex networks are offered. It gives the method for discriminating a reversible branch in a complex network by means of the switching function, and the method of counter inverted logical control of airflow inversion by means of open and short circuit conversion of key branches. The research has solved the problem of the stablization of air flow for normal ventination and reversing ventination in a diagonal network.

Towards Incremental Deployment of Diverse Network Architectures on the Internet

In the past decades, many cleanslate future network architectures have gained limited deployment in current Internet, due to the stability and rigidity of TCP/IP, the narrow waist of the Internet. We first propose three principles that the future Internet architecture should obey to be well-defined network architecture, i.e. supporting service innovation and enabling evolvability. By abstracting different modes from TCP/IP network and SDN technology, we argue that the centric-distributed-centric(CDC) mode has great potential for the well-defined future network architecture in which diverse network architectures could be incrementally deployed and coexist with each other. Prototype system regulated by CDC mode was developed. Experimental results reveal that CDC can support diverse architectures to coexist in the current Internet and thus enables the Internet to evolve.

Data Mapping Principles and Algorithm for Self-Configurable Systems

With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal specification and model finding techniques.In this paper,we pay more attention to formal specifications of network information,i.e.,exploring principles and algorithm to map network information(topology,devices and status,etc.) to Alloy specifications.We first model network information in relational form,which is easy to realize because of the structured feature of network information in nature.Then we map the relational data to Alloy specifications according to our novel data mapping principles and algorithm.Based on the transition of relational data,it is possible to automatically map network information to Alloy specifications.We evaluate our data mapping principles and algorithm by applying them to a practical application scenario.The results illustrate that we can find a model for the task within a tolerant time interval,which implies that our novel approach can convert relational data to Alloy specifications correctly and efficiently.

Cloning and functional characterization of two cDNAs encoding NADPH-dependent 3-ketoacyl-CoA reductased from developing cotton fibers

Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoAreductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed duringthe cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2showed 30%-32% identity to Saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAswere cloned and expressed in yeast haploid ybr159w? mutant that was deficient in 3-ketoacyl-CoA reductase activity.Wild-type growth rate was restored in ybr159w? cells that expressed either GhKCR1 or 2. Further analysis showed thatGhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to theyeast endoplasmic reticulum marker ScKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductaseactivity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest thatGhKCR1 and 2 are functional orthologues of ScYbr159p.

Spatiotemporal distribution of 1P1 antigen expression in the plexiform layers of developing chick retina

Changes in the distribution of 1P1-antigen in the developing chick retina have been examined by indirect immunofluorescence staining technique using the novel monoclonal antibody (MAb) 1P1. Expression of the 1P1 antigen was found to be regulated in radial as well as in tangential dimension of the retina, being preferentially or exclusively located in the inner and outer plexiform layers of the neural retina depending on the stages of development. With the onset of the formation of the inner plexiform layer 1P1 antigen becomes expressed in the retina. With progressing differentiation of the inner plexiform layer 1P1 immunofluorescence revealed 2 subbands at E9 and 6 sub-bands at E18. At postnatal stages (after P3) immunoreac-tivity was reduced in an inside-outside sequence leading to the complete absence of the 1P1 antigen in adulthood. 1P1 antigen expression in the outer plexiform layer was also subject to developmental regulation. The spatio-temporal pattern of 1P1 antigen expression was correlated with the time course of histological differentiation of chick retina, namely the synapse rich plexiform layers. Whether the 1P1 antigen was functionally involved in dendrite extension and synapse formation was discussed.

Stereo garage parking space allocation model and simulation analysis

Based on grey neural network and particle swarm optimization algorithm,an automated stereo garage decision model is proposed to solve the problems of long waiting queue and low efficiency of automated parking garage.The gray neural network is used to forecast the stay time of the vehicle and particle swarm optimization algorithm is used to allocate the parking spaces in the stereo garage.The proposed stereo garage mathematical model is established on condition that vehicle arrival interval obeys Poisson distribution.The performance of stereo garage is evaluated by the average waiting time,average waiting queue length,average service time and average energy consumption of the customers.By comparing the efficiency indexes of the existing model based on near-distribution principle and the proposed model based on gray neural network and particle swarm algorithm,it is proved that the proposed model based on gray neural network and particle swarm algorithm is effective in improving the efficiency of garage operation and reducing the energy consumption of garage.

Recent Implementations in LASP 3.0:Global Neural Network Potential with Multiple Elements and Better Long-Range Description

LASP(large-scale atomistic simulation with neural network potential)software developed by our group since 2018 is a powerful platform(www.lasphub.com)for performing atomic simulation of complex materials.The software integrates the neural network(NN)potential technique with the global potential energy surface exploration method,and thus can be utilized widely for structure prediction and reaction mechanism exploration.Here we introduce our recent update on the LASP program version 3.0,focusing on the new functionalities including the advanced neuralnetwork training based on the multi-network framework,the newly-introduced S^(7) and S^(8) power type structure descriptor(PTSD).These new functionalities are designed to further improve the accuracy of potentials and accelerate the neural network training for multipleelement systems.Taking Cu-C-H-O neural network potential and a heterogeneous catalytic model as the example,we show that these new functionalities can accelerate the training of multi-element neural network potential by using the existing single-network potential as the input.The obtained double-network potential Cu CHO is robust in simulation and the introduction of S^(7) and S^(8) PTSDs can reduce the root-mean-square errors of energy by a factor of two.

Influence of site conditions on ground motion at far field loess sites during strong earthquake

Loess is widely distributed in China and the Loess Plateau is one of the major areas where strong earthquakes often take place. The seismic amplification effects were discovered in the Plateau during the Wenchuan Ms8.0 earthquake and some other strong events. Based on earth tremor observation, borehole exploration and site seismic response analysis, the site effects of topography of Loess Yuan on ground motion were investigated in details. The earth tremor investigation shows that predominant frequencies at the bottom sites of Loess Yuan are greater than those at the top obviously. The sites seismic response analysis shows that the Loess Yuan may amplify peak ground acceleration (PGA) by 1.44 2.0 times. Therefore, site effects of mountains and loess topography on ground motion should be taken account into in seismic design in loess regions.