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21.
A new class of potent, orally active phenyl piperazine-based GH secretagogues have been discovered from attempts to mimic the arrangement of the phenyl substituent in the spiroindanyl piperidine and spiroindoline sulfonamide privileged structures of 4 and 1, respectively. The best of these compounds, 18 (EC50 = 2.8 nM) is nearly as potent as MK-0677 for releasing GH from rat pituitary cells.  相似文献   
22.
Evaluating behavioral interventions for HIV prevention   总被引:1,自引:0,他引:1  
We report a case of primary amyloidosis affecting the kidney and presenting as a renal infarction on computed tomography and ultrasound examination. To our knowledge, it is the first case in the radio-logical literature with these imaging characteristics.  相似文献   
23.
The ever-increasing number of proteins identified as belonging to the family of small heat-shock proteins (shsps) and alpha-crystallins enables us to reassess the phylogeny of this ubiquitous protein family. While the prokaryotic and fungal representatives are not properly resolved, most of the plant and animal shsps and related proteins are clearly grouped in distinct clades, reflecting a history of repeated gene duplications. The members of the shsp family are characterized by the presence of a conserved homologous "alpha-crystallin domain," which sometimes is present in duplicate. Predictions are made of secondary structure and solvent accessibility of this domain, which together with hydropathy profiles and intron positions support the presence of two similar hydrophobic beta-sheet-rich motifs, connected by a hydrophilic alpha-helical region. Together with an overview of the newly characterized members of the shsp family, these data help to define this family as being involved as stable structural proteins and as molecular chaperones during normal development and induced under pathological and stressful conditions.  相似文献   
24.
This paper describes the implementation and evaluation of a nonsanction seat belt law enforcement program in two experimental communities of contrasting size in a state with a mandatory belt law. The main ingredients of the program were seat belt "salutes," public information and education, and limited use of inexpensive economic incentives. Driver shoulder belt use data collected before, during, and after the experimental programs, compared to similar data collected in a comparison community, showed the approach to be effective. While standard seat belt enforcement activities without incentives have been shown to be effective, many police departments, especially in smaller communities, are reluctant to make wholesale increases in seat belt citations. Although requiring some additional level of manpower and resources, a nonsanction approach to seat belt law enforcement can provide an alternate way of increasing belt use in these communities.  相似文献   
25.
A technique amenable to remote sensing use which utilizes laser-induced fluorescence (LIF) properties of plants has been successfully used in the laboratory to identify five major plant types. These included herbaceous dicots, herbaceous monocots, conifers, hardwoods, and algae. Each of these plant types exhibited a characteristic LIF spectra when excited by a pulsed N2 laser emitting at 337 nm. Although monocots and dicots possess common fluorescence maxima at 440, 685, and 740 nm, they could be differentiated from one another by using the ratio of the square of the fluorescence intensity at 440 nm to the nonsquared intensity at 685 nm, i.e., (440)2/685. In all cases, monocots yielded a significantly higher ratio. Conifers have fluorescence maxima at 440, 525, and 740 nm but none at 685 nm. Hardwoods exhibited fluorescence at 440, 525, 685, and 740 nm. Algae had very low fluorescence at 440 nm, no fluorescence at 525 nm, and fluorescence maxima at 685 and 740 nm. For algae, the ratio of the fluorescence intensity at 685 nm to that at 740 nm was much greater than that for monocots, dicots, and hardwoods. The potential use of the LIF technique for individual species identification is suggested.  相似文献   
26.
27.
Necrotizing enterocolitis (NEC) usually occurs in low birth weight infants who have had perinatal stress, and the mortality remains significant. There are a few reports of NEC in the postoperative period, especially in young infants. Nine neonates developed NEC following operations and form the basis of this report. The interval between operation and the diagnosis of NEC varied from 3 days to 4 mo. The surgical lesions included one case each of esophageal atresia, tetralogy of Fallot, supralevator rectal atresia with rectourethral fistula, and multiple intestinal atresias. Three babies had gastroschisis and two had "apple peel" intestinal atresia. Only 3 of the 9 survived. The usual clinical findings of NEC, abdominal distention, bile stained gastric residuals and diarrhea (with or without blood), can occur in the postoperative period without NEC and are, therefore, not reliable diagnostic signs. Significant changes in the clinical course of these babies occurred from 7 hr to 5 days before the diagnosis was established. In these patients the roentgen findings that established the diagnosis of NEC included intestinal ileus, pneumatosis intestinalis, and portal vein gas. Pneumatosis intestinalis and portal vein gas were the most reliable diagnostic signs, but appeared relatively late in the course of the disease. In one case pneumatosis was seen only in retrospect. None of the patients had definite pneumoperitoneum. Awareness of NEC as a potential postoperative complication may result in early recognition, treatment and survival.  相似文献   
28.
108 tendons of the m. extensor hallucis longus were examined with a tensile testing machine within 36 h after death. The specimen were kept at a resting length of 20 mm. After the "steady state" was reached by cyclic loading, the tendons were stretched up to a maximum load of 18 kp, then deloaded to a certain level and after that the elongation was kept constant. At high loading level the tension of the tendon decreases with time (relaxation). At medium and low loading level the tension increases slightly (mechanical recovery). Between that two regions there is a certain load, where the tension will not change with time (isorheological point). The position of the isorheological point depends on the velocity of the elongation. At low velocity (2 mm/min) the isorheological point is situated at 70%, at high velocity (12 mm/min) at 60% of the maximum load. One will find the maximum relaxation, when no deloading occurs. The mechanical recovery, however, has its maximum at 5--25% of the maximum load. But when the tendon is totally deloaded, there seems to occur no recovery. The maximum relaxation is 5 to 6 times larger than the maximum recovery. Supposingly the relaxation- and recovery-processses will happen at the same time but with different intensity depending on the loading level. At least the relaxation-process consists of different relaxation components with different relaxation times. This will explain the phenomenon of a "secondary relaxation": After a long time of registration the recovery will turn into a slight relaxation.  相似文献   
29.
High resolution electron microscopy has been used to examine both the similarities and differences in the growth morphologies of Fe2O3, Cr2O3 as formed on iron alloys, and MgO as formed by burning Mg in moist air. A general discussion is also given of the relative advantages and disadvantages of a variety of TEM techniques as applicable to the study of oxidation phenomena.  相似文献   
30.
In the United States, mechanical foaming is the most popular method for producing warm mix asphalt, which is the latest technology implemented to reduce the production temperature and/or enhance the compactability of asphalt mixtures. Three commonly used commercially available laboratory foamers to produce asphalt foams include the Wirtgen WLB 10S (Wirtgen foamer), the InstroTek Accufoamer (InstroTek foamer) and the Pavement Technology Inc. Foamer (PTI foamer). Though these foamers have been widely used in research studies and construction practice, it is still unknown whether they produce asphalt foams with the same quality and quantity. In this study, asphalt foaming characteristics produced by these three laboratory foamers were measured using a non-contact test set-up consisting of a laser device and a digital camera, and compared in terms of instantaneous volume expansion, foam stability and surface area evolution of foam bubbles. Additionally, the workability, coatability and mechanical performance of foamed mixtures prepared using these same laboratory foamers were compared against the conventional hot mix asphalt (HMA). Test results indicated that foamed asphalts produced by the Wirtgen foamer had the largest volume expansion and greatest foam stability, followed by those produced by the InstroTek foamer and the PTI foamer. The optimum foaming water content (Wopt) was determined for each laboratory foamer based on the workability and coatability results of the corresponding foamed mixtures. In addition, the performance evaluation of the foamed mixtures produced at Wopt values indicated equivalent mixture stiffness but greater moisture susceptibility as compared to the conventional HMA.  相似文献   
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