We developed a water-in-oil-in-water (W/O/W)-type multiple emulsion of a new tacrolimus formulation. A potential approach
to avoid the complications of systemic immunosuppression and simultaneously enhance immunosuppressive efficacy is to deliver
immunosuppressive agents locally to the site of the target organs. The W/O/W emulsion is dispersed oil drops containing smaller
water droplets that allow the delivery of drugs preferentially to the reticuloendothelial system (RES). Since the liver and
the spleen are primary components of the RES, and the brain and the kidney have a poor RES, we hypothesized that a W/O/W emulsion
of tacrolimus would prossess the pharmacokinetic benefits of local immunosuppression. We evaluated this hypothesis in a rat
model. The tacrolimus levels of whole blood, the liver, spleen, brain, and kidney in rats given intravenous emulsions of tacrolimus
(W/O/W group) were compared with a group administered tacrolimus alone (T group). There were no significant differences between
the pharmacokinetic parameters of W/O/W group and T group based on whole blood data. However, the W/O/W group had significantly
decreased tacrolimus levels in the brain and kidney, and significantly increased levels in the liver and spleen compared with
the T group. These data suggest that the W/O/W emulsion is applicable as an intravenous drug carrier for local immunosuppression. 相似文献
In an effort to enhance ductility and strength of Cr-base alloys, a series of Cr-Ru alloys with Ru contents ranging from 3
to 30 at. pct were made to study their microstructure evolution and mechanical properties. The microstructure of the alloys
with 6 to 20 at. pct Ru showed signs of a eutectic structure. However, no corresponding eutectic reaction is indicated in
the published Cr-Ru phase diagram. The yield strength of the Cr-Ru alloys increased with increasing Ru content at both room
temperature and 1200 °C. The tensile ductility of Cr-3 at. pct Ru is about 1.5 pct at room temperature, while the alloys containing
6 at. pct or more Ru showed zero tensile elongation. The deformation mechanisms of the Cr-Ru alloys are discussed in terms
of the microstructure and fracture behavior.
This article is based on a presentation made in the symposium entitled “Beyond Nickel-Base Superalloys,” which took place
March 14–18, 2004, at the TMS Spring meeting in Charlotte, NC, under the auspices of the SMD-Corrosion and Environmental Effects
Committee, the SMD-High Temperature Alloys Committee, the SMD-Mechanical Behavior of Materials Committee, and the SMD-Refractory
Metals Committee. 相似文献
The fundamental characteristics are described of the quantum flux parametron (QPF), measured by a method in which the output signals of the QFP are detected with a DC SQUID. The DC SQUID linearly and continuously converts the output current of the QFP to voltage, allowing the output signal of the QFP to be measured as the voltage of the DC SQUID. The fundamental characteristics of the QFP have been experimentally confirmed in detail 相似文献
Abstract— The growth characteristics of small fatigue cracks were investigated under rotary bending in a high tensile strength steel, and the critical crack length above which linear elastic fracture mechanics (LEFM) is applicable was evaluated systematically from the results of the present study and previous studies in which two steels having different microstructures and strengths were used. It is found that the critical crack length extends over two regions each exhibiting different growth mechanisms. These regions of microstructurally small cracks and mechanically small cracks are found to be a unique function of the microstructural unit size and the yield strength of the materials, respectively. Therefore, using these relationships, it is possible to estimate the critical crack length for a given material. 相似文献
PLLA/PDLA blend films with only stereocomplex crystallites as a crystalline species together with pure PLLA and PDLA films with only homo‐crystallites as a crystalline species were prepared, and the effects of enantiomeric polymer blending, crystalline species, and crystallinity on the water vapor permeability were investigated. The WVT coefficient P of PLLA/PDLA blend films was 14–23% lower than that of pure PLLA and PDLA films in the crystallinity Xc range of 0–30%. Amorphous PLLA/PDLA blend films have a much lower P than pure PLLA and PDLA films. The dependence of P on Xc for blend films was stronger for Xc = 0–30% than for Xc = 30–100%. This dependence is discussed using the Nielsen model and the concept of “restricted” (or “restrained”) and “free” amorphous regions.
Monoclonal antibodies (MAbs) raised against Escherichia coli O6:H16 were screened against 15 strains of E. coli and 19 non-E. coli bacteria. A MAb-luminescence assay using MAb-5.8, which shows no cross-reactions with non-E. coli bacteria, and a photon-counting television camera were developed for rapid enumeration of E. coli O6:H16 in water. The membrane filter that retained bacteria was boiled for 5 min in a buffer and incubated with biotinylated MAb-5.8. After incubation with streptavidin-peroxidase conjugate, it was reacted with luminol-based reaction mixture. Luminous image and light intensity of the filter was recorded with a Biocell Counter. Levels of E. coli O6 higher than 7 x 10(3) CFU were detected by the MAb-luminescence assay when E. coli O6 was spotted onto the membrane filter. The sample that contained E. coli O6:H16 was filtered through a membrane filter, and the filter that retained bacteria was incubated on a filter paper soaked with nutrient broth supplemented with 0.5% NaCl at 37 degrees C for 6 h. The number of light emission points on the filter correlated well with initial E. coli O6:H16 counts within the range of 1 to 3 x 10(2) CFU. The correlation coefficient was 0.89. 相似文献
This study gives fundamental knowledge on the particle classification performance by centrifugal separator.It is found that the cut size of a centrifugal separator decreases as the rotational speed increases and the liquid flow rate decreases. Fitting our experimental results with the theory, they agree with each other at high flow rate. However, the difference between them generates at low flow rate. This is because dead spaces are generated in the centrifugal separator at the low flow rate. Also, the computer simulation of the fluid behavior in the centrifugal separator can find the decrease of the velocity near the wall under the low flow rate, which suggests the possibility of the formation of dead spaces in the separator. 相似文献
In an attempt to improve the guidelines for concurrent management of concomitant abdominal aortic aneurysm (AAA) and symptomatic malignancy, a retrospective study was undertaken. A total of 186 AAA repairs were performed electively, and 25 patients (13.4%) had concurrent symptomatic malignancy from April 1986 to March 1997. Fourteen patients underwent a one-stage operation, including five abdominoperineal rectal resections, four subtotal gastrectomies, three total gastrectomies, and two right hemicolectomies. Eleven others underwent a two-stage operation, including four with total gastrectomy and left hemicolectomy followed by AAA repair, as well as two with right hemicolectomy and one with left hemicolectomy prior to AAA repair. There were no operative deaths or severe postoperative complications. Of the 25 patients, 22 (88.0%) are still alive during follow-up ranging from 8 months to 11 years. Our surgical approach to both lesions is as follows: (1) Using the transperitoneal approach alone, subtotal gastrectomy and abdominoperineal rectal resection can be safely done simultaneously. (2) Although total gastrectomy can also be performed concurrently, the approach used for each lesion is separate. (3) Colorectal resection is generally done separately. However, a one-stage operation can be performed using the thromboexclusion procedure for AAA repair in patients with right-sided colonic cancer or a temporary transverse colostomy for left-sided colorectal cancer. 相似文献