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1.
随着计算机和互联网技术的飞速发展,医院内外网连接更加紧密,通过双核心网络虚拟化建设、内外网连接安全措施、虚拟局域网划分、网管软件的应用、网管人才和使用人员安全意识培养等一系列安全管理措施的实施,形成了一套安全稳定的医院网络系统,提高了网络的可靠性和安全性,保障了医院信息系统不间断安全运行。  相似文献   

2.
Fistula formation after free jejunal transfer for pharyngoesophageal reconstruction is a serious complication with potentially critical consequences. Barium swallow is used postoperatively to check for anastomotic competence before feeding but has been unreliable as a predictor of leak at our institution. The objective of this study was to evaluate the role of routine postoperative barium swallow in 41 consecutive jejunal transfers. Thirty-nine patients who underwent 41 consecutive free jejunal transfers had a routine barium swallow performed between postoperative days 12 and 17. Radiologic findings and clinical outcome were evaluated and correlated. All barium swallows were reviewed by a single experienced radiologist in a blinded fashion. One total and one partial flap failure necessitated a second free jejunal transfer. Pharyngocutaneous fistulae developed after nine free jejunal transfers, of which the barium swallow was normal in four (44 percent) and showed a leak in five (56 percent). In the 32 free jejunal transfers with no clinical leaks, 6 (19 percent) had radiologic leakage of contrast. Thus, barium swallow was normal in 30 patients and showed leakage in 11 patients. Normal barium swallow correlated with uncomplicated clinical course in 26 of 30 cases. In the remaining four cases (13 percent), however, a delayed fistula developed, which was secondary to flap necrosis in one case (negative predictive value 87 percent). On the other hand, radiologic leaks corroborated clinical fistula in 5 of 11 cases (45 percent), whereas no fistula developed in 6 cases (positive predictive value 46 percent). Of the five patients with clinical fistulae, four had early leaks (within 1 week), and the barium swallow did not provide additional information. The fifth patient developed a delayed leak 2 weeks after the barium swallow. Review of these barium swallows at the time of this study reversed the initial report of leakage in three patients, improving the predictive value to 63 percent. These patients had an uncomplicated clinical course. The positive predictive value of clinical assessment alone was 63 percent. We conclude that barium studies following free jejunal transfers can be difficult to interpret, but an experienced radiologist can improve their accuracy. A normal barium swallow, however, does not ensure an uneventful clinical course. Similarly, radiologic leaks do not imply a clinical complication of fistula. Clinical judgment should therefore be exercised in initiating oral intake after free jejunal transfer. Barium swallow should be used only as an adjunct to aid in patient management.  相似文献   

3.
4.
A new method for measuring and correcting airleaks during lung-function testing in infants has been validated invitro and in vivo by using a flow-through system that measured theinflow and outflow of a face mask. An adjustable leak was quantified byusing suction flow to validate the accuracy of leak measurements. Tovalidate the leak correction, the volume of a pump was measured withdifferent air leaks (0-30%). The method developed was tested in67 infants breathing spontaneously. There was good agreement betweenmeasured and simulated leaks (r = 0.998, P < 0.001; 95% limits ofagreement were 0.3 and 0.1%, respectively). The volume wasgenerally underestimated because of leaks, and the volume error was upto 94% compared with the maximum error of 5% after leak correction.With continuous leak measurements in vivo, there were <4% actualleaks (median 2.6%), and we did not observe any leaks in >7% ofcases. The leak correction improved the accuracy of ventilatorymeasurements. The monitoring of leaks is helpful for airtight placementof the face mask and for prevention of serious measurement errorscaused by leaks.

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5.
植保植检工作如何适应社会发展的需要,不断更新工作思路,不断提高植保植检工作水平与效率,是现代植保人必须面对与解决的现实而迫切的课题.本文以重庆市秀山县为例,分析了植保植检技术人员年龄老化、队伍能力整体弱化以及经费保障问题、体制问题、管理问题等植保植检工作面临的困局和问题;提出了植保植检法制化、队伍稳定化、职能专业化、技术研究前沿化、技术应用推广适用化与集成化、农作物病虫害防治协作化、装备现代化、投入多元化、宣传培训常态化等植保植检工作新思路.  相似文献   

6.
Proton and/or sodium electrochemical gradients are critical to energy handling at the plasma membranes of all living cells. Sodium gradients are used for animal plasma membranes, all other living organisms use proton gradients. These chemical and electrical gradients are either created by a cation pumping ATPase or are created by photons or redox, used to make ATP. It has been established that both hydrogen and sodium ions leak through lipid bilayers at approximately the same rate at the concentration they occur in living organisms. Although the gradients are achieved by pumping the cations out of the cell, the plasma membrane potential enhances the leakage rate of these cations into the cell because of the orientation of the potential. This review proposes that cells use certain lipids to inhibit cation leakage through the membrane bilayers. It assumes that Na(+) leaks through the bilayer by a defect mechanism. For Na(+) leakage in animal plasma membranes, the evidence suggests that cholesterol is a key inhibitor of Na(+) leakage. Here I put forth a novel mechanism for proton leakage through lipid bilayers. The mechanism assumes water forms protonated and deprotonated clusters in the lipid bilayer. The model suggests how two features of lipid structures may inhibit H(+) leakage. One feature is the fused ring structure of sterols, hopanoids and tetrahymenol which extrude water and therefore clusters from the bilayer. The second feature is lipid structures that crowd the center of the bilayer with hydrocarbon. This can be accomplished either by separating the two monolayers with hydrocarbons such as isoprenes or isopranes in the bilayer's cleavage plane or by branching the lipid chains in the center of the bilayers with hydrocarbon. The natural distribution of lipids that contain these features are examined. Data in the literature shows that plasma membranes exposed to extreme concentrations of cations are particularly rich in the lipids containing the predicted qualities. Prokaryote plasma membranes that reside in extreme acids (acidophiles) contain both hopanoids and iso/anteiso- terminal lipid branching. Plasma membranes that reside in extreme base (alkaliphiles) contain both squalene and iso/anteiso- lipids. The mole fraction of squalene in alkaliphile bilayers increases, as they are cultured at higher pH. In eukaryotes, cation leak inhibition is here attributed to sterols and certain isoprenes, dolichol for lysosomes and peroxysomes, ubiquinone for these in addition to mitochondrion, and plastoquinone for the chloroplast. Phytosterols differ from cholesterol because they contain methyl and ethyl branches on the side chain. The proposal provides a structure-function rationale for distinguishing the structures of the phytosterols as inhibitors of proton leaks from that of cholesterol which is proposed to inhibit leaks of Na(+). The most extensively studied of sterols, cholesterol, occurs only in animal cells where there is a sodium gradient across the plasma membrane. In mammals, nearly 100 proteins participate in cholesterol's biosynthetic and degradation pathway, its regulatory mechanisms and cell-delivery system. Although a fat, cholesterol yields no energy on degradation. Experiments have shown that it reduces Na(+) and K(+) leakage through lipid bilayers to approximately one third of bilayers that lack the sterol. If sterols significantly inhibit cation leakage through the lipids of the plasma membrane, then the general role of all sterols is to save metabolic ATP energy, which is the penalty for cation leaks into the cytosol. The regulation of cholesterol's appearance in the plasma membrane and the evolution of sterols is discussed in light of this proposed role.  相似文献   

7.
The lack of empirical support for the positive economic impact of information technology (IT) has been called the IT productivity paradox. Even though output measurement problems have often been held responsible for the paradox, we conjecture that modeling limitations in production-economics-based studies and input measurement also might have contributed to the paucity of systematic evidence regarding the impact of IT. We take the position that output measurement is slightly less problematic in manufacturing than in the service sector and that there is sound a priori rationale to expect substantial productivity gains from IT investments in manufacturing and production management. We revisit the IT productivity paradox to highlight some potential limitations of earlier research and obtain empirical support for these conjectures. We apply a theoretical framework involving explicit modeling of a strategic business unit's (SBU)1 input choices to a secondary data set in the manufacturing sector. A widely cited study by Loveman (1994) with the same dataset showed that the marginal contribution of IT to productivity was negative. However, our analysis reveals a significant positive impact of IT investment on SBU output. We show that Loveman's negative results can be attributed to the deflator used for the IT capital. Further, modeling issues such as a firm's choice of inputs like IT, non-IT, and labor lead to major differences in the IT productivity estimates. The question as to whether firms actually achieved economic benefits from IT investments in the past decade has been raised in the literature, and our results provide evidence of sizable productivity gains by large successful corporations in the manufacturing sector during the same time period.  相似文献   

8.
RS Beaman  N Cellinese 《ZooKeys》2012,(209):7-17
New information technologies have enabled the scientific collections community and its stakeholders to adapt, adopt, and leverage novel approaches for a nearly 300 years old scientific discipline. Now, few can credibly question the transformational impact of technology on efforts to digitize scientific collections, as IT now reaches into almost every nook and cranny of society. Five to ten years ago this was not the case. Digitization is an activity that museums and academic institutions increasingly recognize, though many still do not embrace, as a means to boost the impact of collections to research and society through improved access. The acquisition and use of scientific collections is a global endeavor, and digitization enhances their value by improved access to core biodiversity information, increases use, relevance and potential downstream value, for example, in the management of natural resources, policy development, food security, and planetary and human health. This paper examines new opportunities to design and implement infrastructure that will support not just mass digitization efforts, but also a broad range of research on biological diversity and physical sciences in order to make scientific collections increasingly relevant to societal needs and interest.  相似文献   

9.
In recent years, two-photon imaging has become an invaluable tool in neuroscience, as it allows for chronic measurement of the activity of genetically identified cells during behavior1-6. Here we describe methods to perform two-photon imaging in mouse cortex while the animal navigates a virtual reality environment. We focus on the aspects of the experimental procedures that are key to imaging in a behaving animal in a brightly lit virtual environment. The key problems that arise in this experimental setup that we here address are: minimizing brain motion related artifacts, minimizing light leak from the virtual reality projection system, and minimizing laser induced tissue damage. We also provide sample software to control the virtual reality environment and to do pupil tracking. With these procedures and resources it should be possible to convert a conventional two-photon microscope for use in behaving mice.  相似文献   

10.
根据原卫生部提出的手术灭菌器械的可追溯管理要求,采用RFID信息化追溯管理技术,通过与医院HIS对接,结合无线网络、中间件等技术,实现了手术器械从回收、清洗、检查、包装、灭菌、发放和使用各个关键环节信息数据的全程跟踪监控,有效保证了各类手术器械的质量管理,使消毒供应中心工作更加科学、规范、高效、便捷,提升了医院手术器械的管理水平。  相似文献   

11.
Wellbore cement, a procedural component of wellbore completion operations, primarily provides zonal isolation and mechanical support of the metal pipe (casing), and protects metal components from corrosive fluids. These are essential for uncompromised wellbore integrity. Cements can undergo multiple forms of failure, such as debonding at the cement/rock and cement/metal interfaces, fracturing, and defects within the cement matrix. Failures and defects within the cement will ultimately lead to fluid migration, resulting in inter-zonal fluid migration and premature well abandonment. Currently, there are over 1.8 million operating wells worldwide and over one third of these wells have leak related problems defined as Sustained Casing Pressure (SCP)1. The focus of this research was to develop an experimental setup at bench-scale to explore the effect of mechanical manipulation of wellbore casing-cement composite samples as a potential technology for the remediation of gas leaks. The experimental methodology utilized in this study enabled formation of an impermeable seal at the pipe/cement interface in a simulated wellbore system. Successful nitrogen gas flow-through measurements demonstrated that an existing microannulus was sealed at laboratory experimental conditions and fluid flow prevented by mechanical manipulation of the metal/cement composite sample. Furthermore, this methodology can be applied not only for the remediation of leaky wellbores, but also in plugging and abandonment procedures as well as wellbore completions technology, and potentially preventing negative impacts of wellbores on subsurface and surface environments.  相似文献   

12.
Live imaging of large biological specimens is fundamentally limited by the short optical penetration depth of light microscopes. To maximize physical coverage, we developed the SiMView technology framework for high-speed in vivo imaging, which records multiple views of the specimen simultaneously. SiMView consists of a light-sheet microscope with four synchronized optical arms, real-time electronics for long-term sCMOS-based image acquisition at 175 million voxels per second, and computational modules for high-throughput image registration, segmentation, tracking and real-time management of the terabytes of multiview data recorded per specimen. We developed one-photon and multiphoton SiMView implementations and recorded cellular dynamics in entire Drosophila melanogaster embryos with 30-s temporal resolution throughout development. We furthermore performed high-resolution long-term imaging of the developing nervous system and followed neuroblast cell lineages in vivo. SiMView data sets provide quantitative morphological information even for fast global processes and enable accurate automated cell tracking in the entire early embryo.  相似文献   

13.
We investigated the contribution of the inferior temporal (IT) cortical neurons to the active maintenance of internal representations. The activity of single neurons in the IT cortex was recorded while the monkeys performed a sequential-type associative memory task in which distractor stimuli interrupted the delay epoch between the cue and target (paired-associate) stimuli. For each neuron, information about each stimulus conveyed by the delay activity was estimated as a coefficient of multiple regression analysis. We found that target information derived from long-term memory (LTM) persisted despite the distractors. By contrast, cue information derived from the visual system was attenuated and frequently replaced by distractor information. These results suggest that LTM-derived information required for upcoming behavior is actively maintained in the IT neurons, whereas visually derived information tends to be updated irrespective of behavioral relevance.  相似文献   

14.
1. Phospholipids prelabelled with [(14)C]acetate, [(32)P]phosphate, [(3)H]- or [(14)C]-choline or [(3)H]inositol are not significantly degraded during fusion of Lettrée cells mediated by Sendai virus, nor are carbohydrates prelabelled with [(3)H]fucose, [(14)C]galactose or [(3)H]glucosamine. Less than 1nmol of lysophosphatidylcholine/10(7) cells is formed during fusion. Diethyl p-nitrophenyl phosphate, which inhibits phospholipase A by more than 95% has no effect on fusion. It is concluded that none of the events leading to cell fusion is accompanied by significant turnover of phospholipids or other membrane components. 2. Intracellular K(+) leaks out during virally mediated cell fusion; the loss is not as extensive as that of intracellularly accumulated choline or deoxyglucose. Movement of Ca(2+) into or out of cells could not be detected. 3. At concentrations of Lettrée cells insufficient to be agglutinated by virus, intracellularly accumulated choline and deoxyglucose leak out. Agglutination caused by concanavalin A does not result in leakage of intracellular metabolites. 4. P815Y cells, which agglutinate but do not fuse in the presence of virus, show leakage of intracellularly accumulated metabolites. The extent of leakage does not alter during the G(1) and S periods of the cell cycle. 5. Leakage is inhibited by Ca(2+), but is unaffected by EDTA. 6. It is concluded that the interaction of Sendai virus with mammalian cells causes a weakening of membrane integrity so that intracellular metabolites leak out. Such destabilization may facilitate viral entry and is therefore an interesting system for further biochemical studies.  相似文献   

15.
Cloud computing environment came about in order to effectively manage and use enormous amount of data that have become available with the development of the Internet. Cloud computing service is widely used not only to manage the users’ IT resources, but also to use enterprise IT resources in an effective manner. Various security threats have occurred while using cloud computing and plans for reaction are much needed, since they will eventually elevate to security threats to enterprise information. Plans to strengthen the security of enterprise information by using cloud security will be proposed in this research. These cloud computing security measures must be supported by the governmental policies. Publications on guidelines to information protection will raise awareness among the users and service providers. System of reaction must be created in order to constantly monitor and to promptly respond to any security accident. Therefore, both technical countermeasures and governmental policy must be supported at the same time. Cloud computing service is expanding more than ever, thus active research on cloud computing security is expected.  相似文献   

16.
Oxidative damage by diamide, periodate and oxygen-derived reactive species, but also exposure to electroporation induce in the erythrocyte membrane dynamic, presumably fluctuating, defects having the properties of aqueous holes with definable radii and selectivities. These leaks, which can be quantified by measuring tracer fluxes or rates of colloid-osmotic lysis, are here shown to be inhibited by phloretin and a small number of related phenol compounds (phenolphthalein, hydroxyacetophenones, nitrophenol), while a host of other 'membrane-active' agents is not effective in this respect. I50 values range from about 200 microM for phloretin and phenolphthalein to about 10 mM for 4-nitrophenol. Inhibition by phloretin is reversible, not competitive and not related in its extent to the extent of leakiness. In contrast, the enhancement of transbilayer mobility of amphiphilic lipid probes, which invariably goes along with leak formation of the type described, is not affected by phloretin. Aliphatic alcohols (hexanol, butanol) have an amplifying effect on leaks induced by oxidative damage but do not affect leaks induced by electroporation. The alcohol-amplified leaks maintain the properties of aqueous holes as indicated by a low activation energy of leak fluxes. Since both, inhibition and stimulation of leak fluxes do not go along with appreciable changes of the apparent radii of the aqueous holes, changes in the dynamics (opening and closing) of the defects are proposed to underly the effects of phloretin and alkanols. The membrane lipid domain is likely to be the site of the leaks and of their modulation.  相似文献   

17.
BackgroundFibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks.MethodsA comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors.ResultsA total of 1006 database records and additional records were identified. After screening for duplicates and relevance, a total of 78 articles were assessed by the investigators for eligibility. Thirty-eight were excluded and the full-text of 40 articles were included in the qualitative synthesis. Seven of these included only safety data and were included in the safety assessment. The remaining 33 articles included findings from 32 studies that enrolled a total of 2935 patients who were exposed to fibrin sealant. Among these 33 studies there were only 3 randomized controlled trials, with the remaining being prospective cohort analysis, case controlled studies, prospective or retrospective case series. One randomized controlled trial, with 89 patients exposed to fibrin sealant, found a greater rate of intraoperative watertight dura closure in the fibrin sealant group than the control group (92.1% versus 38.0%, p<0.001); however, post-operative cerebrospinal fluid leakage occurred in more fibrin sealant than control patients (6.7% versus 2.0%, p>0.05). Other clinical trials evaluated the effect of fibrin sealant in the postoperative prevention of cerebrospinal fluid leaks. These were generally lower level evidence studies (ie, not prospective, randomized, controlled trials) that were not designed or powered to demonstrate a significant advantage to fibrin sealant use. Two small case series studies evaluated the effect of fibrin sealants in persistent cerebrospinal fluid leak treatment, but did not establish firm efficacy conclusions. Specific adverse reports where fibrin sealants were used for dura sealing were limited, with only 8 cases reported in neurosurgical procedures since 1987 and most reporting only a speculative relationship/association with fibrin sealant exposure.ConclusionsA major finding of this systematic literature review is that there is a paucity of randomized studies that have evaluated the effectiveness and safety of fibrin sealants in providing intraoperative watertight dura closure and post-operative cerebrospinal fluid leakage. Among the limited studies available, evidence from a single randomized, controlled trial indicates that fibrin sealants provide a higher rate of intraoperative watertight closure of the dura suture line than control, albeit with a higher rate of postoperative cerebrospinal fluid leakage. Evidence from non-randomized, controlled trials suggests that fibrin sealants may be effective in preventing cerebrospinal fluid leaks with an acceptable safety profile. There is a substantial need for randomized, controlled clinical trials or well-designed prospective observational trials where the conduct of a randomized trial is not feasible to fully assess the impact of fibrin sealant utilization on the rates of intraoperative dura closure, postoperative cerebrospinal leakage, and safety.  相似文献   

18.
19.
This paper is concerned with finding practical ways of incorporating human and organizational concerns during the development and use of new information technologies (IT). It is structured in four parts. First, we outline the work of the Institute of Work Psychology at the University of Sheffield. One major interest is with the human and organizational aspects of the new information technologies. We are especially interested in work organization and job design, the allocation of tasks between and among humans and computers, the roles of users, the roles of senior managers, the management of change, and the performance of new investments in information technology (IT). Second, we review the evidence from survey work and from detailed case studies concerning the performance of IT. This reveals that most IT investments do not meet their performance objectives, and that the reasons for this are rarely purely technical in origin. Change is too often technology-led, and too little attention is paid to human and organizational factors. Most companies fail to consider how work should be organized and how jobs should be designed to make the new technologies more effective. Usually, users have no substantial influence on system development. Senior managers are criticized for their lack of understanding and action in these areas. Third, we consider the potential in the United Kingdom for changing work systems incorporating new technology. One way forward is through the development and use of sets of theoretically derived tools that can be used by managers and others. To this end we are working with several collaborators on a portfolio of tools in the following areas: organizational design job design allocation of tasks between and among humans and computers. We then review our approach and offer views of the areas and ways in which this work could develop, including opportunities for international collaboration.  相似文献   

20.
Uncoupling protein-1 homologs are hypothesized to mediate mitochondrial proton leak. To test this hypothesis, we determined the effects of ATP and other nucleotides on liver and skeletal muscle mitochondrial non-phosphorylating respiration (VO(2)), membrane potential, FCCP-stimulated respiratory control ratios, and swelling. Neither ATP nor CTP affected liver or muscle proton leak, but both inhibited the respiratory chain. Unexpectedly, CMP stimulated liver proton leak (EC(50) approximately 4.4+/-0.5 mM). Using CMP chromatography, we identified two proteins (M(r)=31.2 and 32.6 kDa) from liver mitochondria that are similar in size to members of the mitochondrial carrier protein family. We conclude (a) liver and muscle mitochondrial proton leak is insensitive to ATP and CTP, and (b) CMP activates a leak in liver mitochondria. The CMP-inducible leak may be mediated by a 30-32 kDa protein. Based on the high concentrations required, CMP is unlikely to be a physiologically important leak regulator. Nonetheless, our results show that tissues other than brown fat have inducible leaks that may be protein-mediated.  相似文献   

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