刍议计算机反病毒技术的产生、发展和现状

随着计算机病毒越来越猖撅,计算机安全越来越受到人们的重视,计算机反病毒技术也发展得越来越快。论文介绍了计算机反病毒的产生,介绍了当今最新最先进的计算机反病毒技术,有CPU反病毒技术、病毒码扫描技术、实时反病毒技术和虚拟机技术等。     

网络商店的付费机制与信息安全分析

随着因特网的发展与普及,产生了更多的商机,造就出各种不同型态的网络商店,同时也衍生出不同的付费方式,例如电子钱包、网上银行、在线ATM等等。面对众多付费方式的选择时,不同市场必须选搭各种付费制度,当市场导入新制付费制度后,除了增加新制付费制度给予消费者选择外,并能让原来的市场消费者对于新付费机制产生消费学习性,最终消费者会依个人意志选择最利己的付费机制。通过调查分析,网络商店提供付费机制使用的便利性、易用性、实时性、精确性、安全性对消费者态度有显著正向的影响。     

Superelectrophilic solvation

Nucleophilic solvation is the interaction of electron-donor solvents with electron-deficient reagents. Electrophilic solvation is the related reverse interaction. Superelectrophilic solvation involves the interaction of electron-donating groups (ligands) of overall electron-deficient species (electrophiles) with strongly electron-acceptor superacids. It occurs with liquid superacids, on solid acids, and even in some enzymatic biological systems. Diminishing neighboring group participation of the electrophilic centers by the affected groups greatly enhances their electrophilic reactivities (superelectrophilic activation), resulting in unusual reactions of substantial interest. Representative examples of superelectrophilic solvation are discussed.     

Phage mimotopes of monoclonal antibodies against plasma membrane Ca2+-ATPase

Libraries of random phage-displayed pentadeca- and hexapeptides were screened with the use of four monoclonal antibodies against the human plasma membrane Ca2(+)-ATPase. Bacteriophages specifically binding the antibodies were selected, and the amino acid sequences of the expressed peptides (mimotopes) were determined. Mimotopes for three antibodies (8B8, 2D8, F9) did not correspond to the Ca2(+)-ATPase sequence. Pentadecapeptides for the 7C8 antibodies displayed similarity to the fragment Glu1097-Arg1113 of the Ca2(+)-ATPase calmodulin-binding site. However, these antibodies failed to bind recombinant fragment Leu1069-Leu1220; therefore, the structure of this epitope remains obscure. This work opens a series of studies of the plasma membrane Ca2(+)-ATPase structure by means of monoclonal antibodies and the phage display method.     

The diagnostic importance of antibodies to the cell wall peptidoglycan of Staphylococcus in the blood serum of children with a staphylococcal infection

High titers of antibodies to peptidoglycan of staphylococcus aureus were found in children with purulent-inflammatory diseases of staphylococcal etiology. This may be used for the diagnosis of staphylococcal infection.     

Bone densitometry: patients receiving prolonged steroid therapy

Bone mass loss and osteoporosis are associated with various conditions, such as asymptomatic primary hyperparathyroidism, and treatments, such as prolonged steroid therapy. Bone densitometry is used to measure bone mass density to determine the degree of osteoporosis and to estimate fracture risk. Bone densitometers measure the radiation absorption by the skeleton to determine bone mass of the peripheral, axial, and total skeleton. Common techniques include single-photon absorptiometry (SPA) of the forearm and heel, dual-photon (DPA) and dual-energy x-ray absorptiometry (DXA) of the spine and hip, quantitative computed tomography (QCT) of the spine or forearm, and radiographic absorptiometry (RA) of the hand. Part I of this report addresses important technical considerations of bone densitometers, including radiation dose, site selection, and accuracy and precision, as well as cost and charges. Part II evaluates the clinical utility of bone densitometry in the management of patients receiving prolonged steroid therapy. Steroids have broad effects on both immune and inflammatory processes and have been used to treat a wide variety of immunologically mediated diseases. Osteoporosis and vertebral compression fractures have been considered major complications of prolonged steroid therapy. Bone loss is also a direct result of many of the diseases treated with steroids. Issues addressed are the type and extent of bone loss associated with steroid therapy, risk for fracture, whether steroid dose reduction or alternative therapy is an option, and whether osteoporosis associated with prolonged steroid use can be prevented or treated. The other assessments in this series address the clinical utility of bone densitometry for patients with: asymptomatic primary hyperparathyroidism, end-stage renal disease, vertebral abnormalities, and estrogen-deficient women.     

Host NK cells are required for the growth of the human filarial parasite Brugia malayi in mice

Human lymphatic filariasis, which afflicts an estimated 120 million people worldwide, is caused by the large nematode parasites Wuchereria bancrofti and Brugia malayi. Filarial nematodes require both an arthropod vector and a mammalian host to complete their life cycle. Within the definitive (mammalian) host, the lymphatic filarial parasites reside in the lymph nodes and lymphatics, a seemingly hostile environment for infectious agents, since the location exposes them to the immune defenses of the host. We present data here that suggest that the growth of B. malayi in the mammalian host is dependent on host NK cell function. Comparisons of worm survival and development in different strains of mice with varying levels of NK cell activity reveal that NOD/LtSz-scid/scid and NOD/LtSz-scid/scid B2m(null) mice (with diminished to absent NK cell activity respectively), are nonpermissive to worm growth, while C.B-17-scid/scid mice with normal NK cell activity are highly permissive. Depletion of NK cells in the permissive C57BL/6J-scid/scid mice renders them nonpermissive to B. malayi growth, whereas stimulation of NK cells in NOD/LtSz-scid/scid mice makes them permissive. Tg epsilon26 mice, which lack NK and T cells, are nonpermissive, but, when reconstituted with NK cells by adoptive transfer of bone marrow cells from C57BL16J-scid/scid mice, are rendered permissive. This requirement for NK cell activity may explain the site specificity of these parasites. Furthermore, these data suggest that the interaction of the host immune system with the filarial parasite is double edged, with both host protective and parasite growth-promoting activities emanating from the former.     

Immunodepressive effect of transcerebral lasers

The aim of the present paper was to study the effect of infrared laser radiation on endocrine regulation of immunogenesis and on endogenic opioid system. For this purpose experiments on rabbits were carried out. The animals underwent transcerebral radiation with subsequent induction of the primary immune response (PIR) to thymus-dependent antigen (sheep red blood cells). The PIR suppression was revealed in all test animals. It was more graphically expressed in rabbits exposed to impulse radiation. Immunodepression was combined with the increase of glucocorticoid activity of adrenal cortex, while no significant changes in thyroid hormones were registered. The 0.08 Joles impulse radiation cause a palpable fall in opioid concentration in blood plasma, the fact, which can be possibly accounted for the rapid exhaustion of opioid synthesis after their stimulation due to laser radiation.     

In vitro assessment of the biological activity of basic fibroblast growth factor released from various polymers and biomatrices

The kinetics of controlled release of basic fibroblast growth factor (bFGF) from polymers (sutures, polycarbonate, Hydron, and Elvax), biopolymers (alginate), and biomatrices (lens capsules), and conditions for storage of bFGF (temperature, plastic type, heparin) were evaluated in vitro. Tissue culture proliferation bioassays with 3T3 fibroblasts, showed that only lens capsules with bFGF had a sustained release of bFGF for up to three weeks. The other materials released all of the 'bound' bFGF with two hours or produced an inflammatory response in vivo. Therefore, the lens tissue had the most potential for controlled long-term delivery of bFGF in vivo. These studies emphasise the importance of in vitro analysis of release kinetics of growth factors from a range of materials as a basis for potential in vivo applications.