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71.
Possibilities of involution of changes in lesser circulation after closure of experimental aortopulmonary anastomosis were studied. 37 observations at various intervals after closure of anastomosis (several minutes to 13.5 months) in 25 dogs were analyzed. Before closure the anastomosis had functioned for 1-7 months. The results of histological examinations of lungs, pressure measurements in lesser circulation, heart weight, electrocardiographic and spirographic examinations were analyzed. It was found that complete involution of changes in lesser circulation was possible only in first month of existence of anastomosis, in this case with changes of both "early" and "late" types. "Late"-type changes after four months function of anastomosis had both reversible and irreversible character, whereas "early"-type changes became irreversible already after three-month duration of anastomosis. With the "late"-type changes, the operation itself (closure of anastomosis) was accompanied by symptoms of pulmonary vasomotor paresis and heart failure, whereas in the presence of "early"-type changes the operation elicited no morphological or functional changes. 相似文献
72.
Between 1945 and 1970, 101 children (86 girls and 15 boys) with systemic lupus erythematosus were evaluated at the Mayo Clinic. Only 9 children were less than 9 years old at the time of diagnosis. The most frequent presenting complaint was arthralgia; fever, fatigue, and a "butterfly" malar rash also were common. Renal involvement, found in more than 76 per cent of patients, was a prognostically poor sign. The overall survival of children with renal involvement is improved by the use of adequate steroid therapy. 相似文献
73.
DG Pennington 《Canadian Metallurgical Quarterly》1977,60(3):468-469
A suction catheter technique is suggested as the next procedure of choice when proximal digital "milking" with wrist flexion fails to deliver the proximal end of the flexor tendon severed within the digital sheath. 相似文献
74.
Bypass surgery for vascular disease of the carotid system 总被引:2,自引:0,他引:2
TM Sundt RG Siekert DG Piepgras FW Sharbrough OW Houser 《Canadian Metallurgical Quarterly》1976,51(11):677-692
A series of 58 operations on 56 patients, in whom a branch of the superficial temporal artery was anastomosed to a branch of the middle cerebral artery (STA-MCA bypass or Yasargil procedure), is reviewed. These operations were performed chiefly for occlussions or for inaccessible stenotic lesions of the internal carotid or middle cerebral arteries. Patency in eight patients operated on from April 1971 through November 1973 was low (25%). Patency in patients operated on since July 1974 has been high (95%). There have been no deaths and no major ischemic strokes attributable to the surgery. The rationale for this procedure is considered in relationship to the anatomy and physiology of the cerebral circulation and the pathogenesis of syndromes of cerebral ischemia. The operation appears to have a low morbidity in good-risk patients. The role of this operation in managing common manifestations of cerebral vascular disease such as focal transient cerebral ischemic attacks (TIAs) and amaurosis fugax, although not fully established, appears encouraging. The procedure seems useful for orthostatic cerebral ischemia caused by multiple occlusions of major extracranial (and intracranial) vessels and, occasionally, for progressing strokes related to internal carotid artery occlusion, both of which are relatively uncommon manifestations of cerebral vascular occlusive disease. It may have application in the rare "slow stroke." The procedure is probably of limited value, if any, in the management of large completed infarcts but may be indicated in selected patients with small infarctions who have preserved most of their cerebral function and who have had evidence of subsequent focal ischemic events. The procedure is useful for bypassing giant aneurysms or basofrontal tumors invading major vessels. It may have a role in the management of fibromuscular disease of the internal carotid artery. 相似文献
75.
76.
Pavec D. Aubin C.-E. Aissaoui R. Parent F. Dansereau J. 《IEEE transactions on neural systems and rehabilitation engineering》2001,9(4):362-368
A computer kinematic model was developed to simulate the lateral and transverse stabilities of wheelchair users in order to compare the effect of different backrests. This model is composed of ellipsoids and parallelepipeds representing the main components of the human body, the seating devices and the wheelchair. A fifteen-segment three-dimensional (3-D) model linked by spherical and revolute joints was created using the ADAMS software (Mechanical Dynamics, Inc.). Torsional springs and dampers are used at the joints to represent four sets of articulation stiffness. Seating devices are represented with 45 rectangular surface patches. The interface between human body and seating devices is modeled by contact elements, which included the specification of stiffness, damping, and deformation of cushions and buttocks. Simulations of a user and his wheelchair moving at 1.4 m/s on a tilted pathway were performed. Different indexes [trunk lateral tilt (TLT) and trunk transverse rotation (TTR)] were measured and compared to those of a similar experimental study on four subjects. The effect of joint stiffness was quantified and a sensitivity study showed the importance of the hip, neck, lumbar, and thoracic joint stiffness on model response (between 16% and 68%). Two backrests (standard and highly contoured) were tested with the kinematic model and their stability compared. Overall, the coherence between the simulations and the experiments shows that this approach is appropriate to compare various seating devices (maximal difference of 1.3° between the simulated and experimental curves for the intermediate joint stiffness sets). The smallest rotations of the highly contoured backrest (6.3° versus 8.9° for TLT and 3.9° versus 6.7° for TTR) suggest that the contouring of the mid torso is more efficient than the lower torso to provide stability to the wheelchair user. This model is an adequate tool to test and improve the design of seating aids 相似文献
77.
Mohammad Shafee Alkanawati Frederik R. Wurm Héloïse Thérien‐Aubin Katharina Landfester 《大分子材料与工程》2018,303(1)
Polymer nanocarriers are used as transport modules in the design of the next generation of drug delivery technology. However, the applicability of nanocarrier‐based technology depends strongly on our ability to precisely control and reproduce their synthesis on a large scale because their properties and performances are strongly dependent on their size and shape. Fundamental studies and practical applications of polymer nanocarriers are hampered by the difficulty of using the current methods to produce monodispersed nanocarriers in large quantities and with high reproducibility. Here, a versatile and scalable approach is reported for the large‐scale synthesis of polymer nanocarriers from water‐in‐oil miniemulsions. This method uses microfluidization to perform a controlled emulsification and is proven to be effective to prepare nanocarriers of different biopolymers (polysaccharides, lignin, proteins) up to 43 g min?1 with reproducible size and distribution. 相似文献
78.
JA Turpin Y Song JK Inman M Huang A Wallqvist A Maynard DG Covell WG Rice E Appella 《Canadian Metallurgical Quarterly》1999,42(1):67-86
Nucleocapsid p7 protein (NCp7) zinc finger domains of the human immunodeficiency virus type 1 (HIV-1) are being developed as antiviral targets due to their key roles in viral replication and their mutationally nonpermissive nature. On the basis of our experience with symmetrical disulfide benzamides (DIBAs; Rice et al. Science 1995, 270, 1194-1197), we synthesized and evaluated variants of these dimers, including sets of 4,4'- and 3,3'-disubstituted diphenyl sulfones and their monomeric benzisothiazolone derivatives (BITA). BITAs generally exhibited diminished antiviral potency when compared to their disulfide precursors. Novel, monomeric structures were created by linking haloalkanoyl groups to the benzamide ring through -NH-C(=O)- (amide) or -S-C(=O)- (thiolester) bridges. Amide-linked compounds generally lacked antiviral activity, while haloalkanoyl thiolesters and non-halogen-bearing analogues frequently exhibited acceptable antiviral potency, thus establishing thiolester benzamides per se as a new anti-HIV chemotype. Pyridinioalkanoyl thiolesters (PATEs) exhibited superior anti-HIV-1 activity with minimal cellular toxicity and appreciable water solubility. PATEs were shown to preferentially target the NCp7 Zn finger when tested against other molecular targets, thus identifying thiolester benzamides, and PATEs in particular, as novel NCp7 Zn finger inhibitors for in vivo studies. 相似文献
79.
Aubin J.-P. Lygeros J. Quincampoix M. Sastry S. Seube N. 《Automatic Control, IEEE Transactions on》2002,47(1):2-20
Impulse differential inclusions are introduced as a framework for modeling hybrid phenomena. Connections to standard problems in the area of hybrid systems are discussed. Conditions are derived that allow one to determine whether a set of states is viable or invariant under the action of an impulse differential inclusion. For sets that violate these conditions, methods are developed for approximating their viability and invariance kernels, that is the largest subset that is viable or invariant under the action of the impulse differential inclusion. The results are demonstrated on examples 相似文献
80.
L. H. Greene M. Aprili M. Covington E. Badica D. E. Pugel H. Aubin Y.-M. Xia M. B. Salamon Sha Jain D. G. Hinks 《Journal of Superconductivity》2000,13(5):703-708
An emphasis on reliable materials growth and development of new fabrication techniques has allowed us to investigate the electronic structure of high-temperature superconductors by planar quasiparticle tunneling and electron paramagnetic resonance (EPR) spectroscopies. The quasiparticle (QP) density of states (DoS) is investigated by tunneling into oriented thin films of Y1Ba2Cu3O7 (YBCO) and single crystals of Ba2Sr2Ca1Cu2O8 (BSCCO). Data are obtained as a function of crystallographic orientation, temperature, doping, damage, and applied magnetic field. These data demonstrate that the observed zero-bias conductance peak (ZBCP) is composed of Andreev bound states (ABS) which intrinsically form at a symmetry-breaking interface of an unconventional superconductor, for example, a (110)-surface of d-wave YBCO. Tunneling into doped or ion-damaged YBCO provides a measure of the QP scattering rate below T
c. An applied field causes Doppler shift of the ABS, arising from the scalar product between the QP velocity and the superfluid momentum, v
F·P
s, observed as a splitting in the ZBCP. Magnetic hysteresis of the splitting is consistent with the effects of strong vortex pinning near the interface. The directional field dependence shows that the ABS is highly anisotropic in its transport. These results, plus in-plane crystallographic orientational dependence on single-crystal BSCCO, demonstrate the d-wave symmetry of this superconductor. Below 8 K and in zero applied field, the ZBCP splits, indicating a transition into a superconducting state with spontaneously broken time-reversal symmetry (BTRS). EPR experiments are used to detect directly the spontaneous formation of the magnetic moments in the BTRS state. 相似文献