Why patients fail to attend psychiatric outpatient follow-up: a pilot study

BACKGROUND/AIM: Traditionally, orthotopic liver transplantation has consisted of a total native hepatectomy that included retrohepatic inferior vena cava. The so-called "piggyback" technique was described by Tzakis et al. (2). It consists of a recipient hepatectomy with preservation of the native retrohepatic IVC and subsequent anastomosis of the homograft suprahepatic IVC to a cuff fashioned from the recipient's suprahepatic veins. In this study, a single surgeon's experience with both techniques during the same period of time is discussed to analyze any significant differences in survival, intraoperative blood loss, length of stay in the ICU, and total length of stay in the hospital. MATERIALS AND METHODS: Over a three year period, 128 patients were transplanted at the University of Pittsburgh. Of these, 66 patients (51.6%) had a piggyback (PB) operation while the remaining 62 (48.4%) had a "standard" (ST) operation. RESULTS: The actual 6 month survival was 81.8% in the PB group (54/66) and 74.2% in the ST group (46/62), with no statistical difference between the two. The median intraoperative blood usage was 6 units for the PB group versus 10 units for the ST group (p > 0.02). The median ICU length of stay was the same at 4 days, as was the total hospitalization duration, 21 days. The in-hospital deaths were included in the analysis. CONCLUSIONS: The piggyback technique has some advantages, including less bleeding and absence of brachial plexus or phrenic nerve injury. Several other important considerations are discussed. In conclusion, the results with the piggyback technique are equivalent to those obtained with the standard approach.     

Efficient group Diffie–Hellman key agreement protocols

In a group Diffie–Hellman (GDH) key agreement protocol, all group members collaboratively establish a group key. Most GDH key agreement protocols took natural generalization of the original Diffie–Hellman (DH) key agreement protocol to arrange all group members in a logic ring or a binary tree and to exchange DH public keys. The computational cost and the communication rounds are the two most important factors that affect the efficiency of a GDH protocol when there are a large number of group members. In this paper, we propose GDH key agreement protocols based on the secret sharing scheme. In addition, we use a one-way key confirmation and digital certificates of DH public keys to provide authentication of group keys. In the proposed authenticated GDH key agreement protocol, each group member requires to broadcast three-round messages, n modular exponentiations, n polynomial interpolations and n one-way functions. Our proposed solution is efficient, robust and secure.     

随机多相材料微观结构的三维统计重构

根据材料平面图像提供的局限的统计信息重构随机材料的三维微观结构是科学与工程中广泛研究的重要课题,而仅由样本提供的信息进行统计重构一直是一个公开的问题.综述了近年来多相材料三维微观结构的统计重构所使用的Gaussian随机场、JQA法、随机优化、信息论和模式识剐等主要方法的研究情况,在此基础上,提出了一些有待解决的问题,并展望了发展前景.     

Application of nanoindentation testing to study of the interfacial transition zone in steel fiber reinforced mortar

The characteristics of the profiles of elastic modulus and hardness of the steel fiber-matrix and fiber-matrix-aggregate interfacial zones in steel fiber reinforced mortars have been investigated by using nanoindentation and Scanning Electron Microscopy (SEM), where two sets of parameters, i.e. water/binder ratio and content of silica fume were considered. Different interfacial bond conditions in the interfacial transition zones (ITZ) are discussed. For sample without silica fume, efficient interfacial bonds across the steel fiber-matrix and fiber-matrix-aggregate interfaces are shown in low water/binder ratio mortar; while in high water/binder ratio mortar, due to the discontinuous bleeding voids underneath the fiber, the fiber-matrix bond is not very good. On the other hand, for sample with silica fume, the addition of 10% silica fume leads to no distinct presence of weak ITZ in the steel fiber-matrix interface; but the effect of the silica fume on the steel fiber-matrix-aggregate interfacial zone is not obvious due to voids in the vicinity of steel fiber.     

Experiences with the New York State Bovine Leukosis Virus Eradication and Certification Program

The Diagnostic Laboratory at the Veterinary College at Cornell University has offered a bovine leukosis virus (BLV) eradication/ certification program since 1985. The program has been popular with purebred breeders since its inception. Recently, many commercial dairymen have also begun participating to reduce the high incidence of clinical leukosis observed in their heavily infected herds. Eradication is achieved through a management and testing program designed to meet the needs of each farm. Over the years, experiences and observations have elucidated a number of factors that significantly affect the rate of progress and time required for a herd to become "BLV-Free."     

Computation-efficient key establishment in wireless group communications

Wireless Networks - Efficient key establishment is an important problem for secure group communications. The communication and storage complexity of group key establishment problem has been studied...     

Task‐based conceptual graphs as a basis for automating software development

It is widely recognized that requirements engineering is a knowledge‐intensive process and cannot be dealt with using only a few general principles. Since knowledge plays a crucial role in software development, software engineers have to describe and organize various aspects of knowledge before the program can be written. A recent work by Robillard reveals that software development can be further improved by recognizing the relevant knowledge structures. In this paper, we propose the use of a task‐based conceptual graphs (TBCB) framework as a basis for automating software development. By structuring and operationalizing conceptual graphs, TBCG specifications can be transformed into executable programs automatically. To construct a conceptual model, task‐based specification methodology is used as the mechanism to structure the knowledge captured in conceptual models, whereas conceptual graphs are adopted as the formalism to express task‐based specifications and to provide a reasoning capability for the purpose of automation. Once task‐based graphs have been constructed and verified, a blackboard system will automatically transform TBCG specifications into a software system composed of database schemas, knowledge base, and user interfaces. A meeting scheduling system is used as an illustrative example to demonstrate our approach. © 2000 John Wiley & Sons, Inc.     

Growth of transplanted tumours in mice treated with macrophages and their products

The antitumour activity of peritoneal macrophages, added to tumour inocula (Winn test), was determined. Macrophages harvested from mice immunised with tumour, or from tumour-bearing mice, suppressed or inhibited tumour growth when in direct contact with tumour cells. Incubation of macrophages exhibiting antitumour activity with tumour cells yielded supernatant fluids capable of interfering with tumour growth. Consistent induction of antitumor activity required either addition of indomethacin to the incubation mixture, or collection of macrophages from immunised or tumour-bearing donors that had ingested indomethacin in the drinking water. Tumour growth was significantly inhibited when tumour inocula were suspended in supernatant fluid, or when mice were given several subcutaneous injections of supernatant prior to tumour transplantation.     

Interdisciplinary question generation: Synthesis and validity analysis of the 1993–1997 bovine mastitis-related literature

Interdisciplinary synthesis and validity analysis (ISVA), a structured learning approach which integrates learning and communication theories, meta-analytic evaluation methods, and literature management-related technologies was applied in the context of the 1993–1997 bovine mastitis research literature. This study investigated whether ISVA could: 1) facilitate the analysis and synthesis of interdisciplinary knowledge claims, and 2) generate projects or research questions. The bovine mastitis-related literature was conceptualized as composed of microbiological, immunological, and epidemiological dimensions. Keywords involving these dimensions were searched in theMedline andAgricola databases. A final list of 148 articles were retrieved, analyzed, synthesized into fifteen information sub-sets, and evaluated for construct, internal, external and statistical validity through an interdisciplinary iterative dialogical process. Validity threats were re-phrased as new research or educational projects.     

Whole milk extender with antibiotics to eliminate Campylobacter fetus from frozen bovine semen

Fresh bovine semen was contaminated with five strains of Campylobacter fetus at 10(5) to 10(6) organisms per ml of semen. The contaminated semen was processed to contain 500 units of polymyxin B, 500 units of penicillin G, and 1000 micrograms of streptomycin sulfate per ml, incubated at 35 degrees C for 10 min, and added then to whole milk extender with like units of antibiotics for further processing. Both a low and high initial sperm count requiring extension rates 1:7 and 1:39 were studied. Specimens for bacterial viability were processed for culture prior to adding bacteria, 100 min after initial antibiotic treatment, prior to freezing, and after thawed semen was centrifuged and washed to remove extender and antibiotic residue. All strains of Campylobacter fetus were not viable 6 h postantibiotic treatment prior to freezing. All nonantibiotic treated controls were viable after thawing and washing. Removal of antibiotics from thawed semen by centrifugation and washing indicated that antibiotics had bactericidal rather than only bacteriostatic activities against Campylobacter fetus.