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1.
The c-axis preferred orientation of ZnO film is the most important factor for its successful application in piezoelectric devices. The effects of surface roughness of the substrate on the c-axis preferred orientation of ZnO thin films, deposited by radio frequency magnetron sputtering, were investigated. During sputtering, the oxygen content in the argon environment used was varied from 0 to 70% at a total sputtering pressure of 10 mTorr. Very smooth Si, smooth evaporated Au/Si, smooth evaporated-Al/Si, and rough sputtered-Al/Si were used as substrates. Their r.m.s. roughnesses, as measured by atomic force microscopy, were 1.27, 17.1, 21.1 and 65-118 Å, respectively. The crystalline structure and the angular spread of the (0 0* 2) plane normal to the ZnO films were determined using X-ray diffraction and X-ray rocking curves, respectively. The crystallinity and the preferred c-axis orientation of the ZnO films were strongly dependent on the surface roughness of the substrates rather than on the oxygen content of the working environment or on the chemical nature of the substrate. 相似文献
2.
1. Intracerebroventricular (i.c.v.) injection of choline (25-150 micrograms) increased blood pressure in rats made acutely hypotensive by haemorrhage. Intraperitoneal administration of choline (60 mg kg-1) also increased blood pressure, but to a lesser extent. Following i.c.v. injection of 25 micrograms or 50 micrograms of choline, heart rate did not change, while 100 micrograms or 150 micrograms i.c.v. choline produced a slight and short lasting bradycardia. Choline (150 micrograms) failed to alter the circulating residual volume of blood in haemorrhaged rats. 2. The pressor response to i.c.v. choline (50 micrograms) in haemorrhaged rats was abolished by pretreatment with mecamylamine (50 micrograms, i.c.v.) but not atropine (10 micrograms, i.c.v.). The pressor response to choline was blocked by pretreatment with hemicholinium-3 (20 micrograms, i.c.v.). 3. The pressor response to i.c.v. choline (150 micrograms) was associated with a several fold increase in plasma levels of vasopressin and adrenaline but not of noradrenaline and plasma renin. 4. The pressor response to i.c.v. choline (150 micrograms) was not altered by bilateral adrenalectomy, but was attenuated by systemic administration of either phentolamine (10 mg kg-1) or the vasopressin antagonist [beta-mercapto-beta,beta-cyclopenta-methylenepropionyl1, O-Me-Tyr2,Arg8]-vasopressin (10 micrograms kg-1). 5. It is concluded that the precursor of acetylcholine, choline, can increase and restore blood pressure in acutely haemorrhaged rats by increasing central cholinergic neurotransmission. Nicotinic receptor activation and an increase in plasma vasopressin and adrenaline level appear to be involved in this effect of choline. 相似文献
3.
Sex-peptide (SP), which is secreted by the accessory gland of Drosophila males, is transferred to the female during copulation, thereby reducing her sexual appetite (receptivity to males) and stimulating ovulation/oviposition. SP is known to be taken up into the hemolymph of mated females, but it is not clear whether there are two separate target tissues, for behavioral changes and ovulation or only one target for both responses. We have employed the GAL4-UAS system to express SP transgene constructs, both in different tissues and in different cellular components of virgin females. A cytoplasmic form of SP lacking a signal sequence did not evoke any responses, even when expressed ubiquitously. In contrast, a membrane-bound form of SP induced typical post-mating behavior, indicating that SP must be outside the cell in order to exert its biological effects. A total of 204 randomly selected P[GAL4] enhancer-trap lines were screened for their ability to induce SP responses in combination with the membrane-bound SP expressed under GAL4 control. Thirty-three lines were associated with both behavioral change and stimulated ovulation. No line was associated with only one of the two responses, implying that the SP target(s) mediating the two responses are either identical, very closely located, or present in two distinct tissues with a common set of genetic determinants. Western blot analysis of head, thorax, and abdominal extracts revealed that the biological activity was correlated with expression in the head fraction. 相似文献
4.
Family nursing, always a component of nursing, has been recently receiving increased attention through publications, educational programs, clinical practice settings and family nursing research. Nurses are in the best position to assist families experiencing the illness of a loved one, but often lack the skills and confidence necessary to assist with the psychosocial needs. The purpose of this paper is to describe the development and implementation of a family nursing program within a large, tertiary care facility. The program's evaluation is ongoing but early outcomes indicate that day-to-day nursing practice has been positively influenced and improved job satisfaction may result. 相似文献
5.
6.
EB Poluéktova NK Khitrov VI Andreev SG Pak BK Danilkin 《Canadian Metallurgical Quarterly》1997,69(11):14-16
Changes in the activity of acid phosphatase (AP) and its isoenzymes (tartrate-insensitive AP and formalin-insensitive AP) were investigated in patients with food poisoning in the course of the disease. The activity of AP and its isoenzymes in the serum started to grow in early convalescence and reached maximum in late convalescence. Total activity of AP in food toxic infections consists primarily of the activity of its platelet fraction. AP activity may serve as an additional criterion to predict vascular platelet involvement of hemostasis. 相似文献
7.
A novel monoclonal antibody to 6 beta-hydroxycortisol (6 beta-OHC) was generated and incorporated into an antigen-coated indirect enzyme-linked immunosorbent assay (ELISA) using 6 beta-OHC-protein conjugate as the steroid-coating antigen. The monoclonal antibody is specific to 6 beta-OHC and 6 beta-OHC-3-carboxymethyloxime. Cross-reactivity with other structurally related steroids such as cortisol, cortisone, and 6 beta-hydroxycortisone was less than 10%. Two different clones (clone 5C1 and 19F) of the monoclonal anti-6 beta-OHC antibody have been developed, each with slightly different sensitivity and specificity. The sensitivity of the MAb clones was not significantly improved when compared to the rabbit polyclonal antibodies in this study, but still within the accepted detection limit for 6 beta-OHC in both human and laboratory animals. The assay had a detection limit of 200 ng/ml, an intraassay variation of 6.4% and an interassay variation of 7.3%. The application of the anti-6 beta-OHC-MAb-based-ELISA was tested by measuring the urinary output of 6 beta-OHC in human before and after enzyme induction by rifampicin treatment. The mean 24-h urine output of 6 beta-OHC in human subjects was 485 +/- 100 micrograms and 1478 +/- 281 micrograms before and after rifampicin administration, respectively. In conclusion, the monoclonal anti-6 beta-OHC antibody developed in this study has the required specificity and sensitivity as an alternative method for measuring urinary 6 beta-OHC in the detection of enzyme induction or enzyme inhibition of CYP3A in humans and laboratory animals. 相似文献
8.
MW Beatty ML Swartz BK Moore RW Phillips TA Roberts 《Canadian Metallurgical Quarterly》1993,27(3):403-413
Seven mechanical/physical properties were used to evaluate 10 unfilled resins: eight aromatic dimethacrylates and two urethane dimethacrylates. Physical property tests included compressive strength, Young's modulus in compression, uniaxial tensile strength, intrinsic yield point, toothbrush abrasion, Knoop hardness, and water sorption. Controlled changes were made in the following four material parameters: amount of crosslinking diluent present in the uncured monomer, functionality of the monomer, repeat unit chemistry of the monomer (urethane vs. aromatic structure) and mode of activation (chemical vs. visible light). Polymers containing a high concentration of crosslinking agent (50 wt%) were found to be tougher and to possess lower hardness than materials containing lesser amounts of crosslinking agent. This was attributed to the flexible nature of the triethylene glycol dimethacrylate crosslinking molecule. Exposure to water plasticized the highly crosslinked materials to the degree that the yield point and elastic modulus were effectively lowered. Most of the tested properties were unaffected by differences in functionality except resistance to toothbrush abrasion, which was enhanced for polymers derived from high functionality monomers. The urethane-based polymers sorbed substantially more water than the aromatic-based materials, which presumably resulted in lower values for surface hardness. However, the urethane resins were very tough, and excellent resistance to toothbrush abrasion was observed. Property differences caused by differences in activation mode were small, although the visible light materials did sorb more water. 相似文献
9.
G Vennarecci BK Gunson T Ismail SG Hübscher DA Kelly P McMaster E Elias 《Canadian Metallurgical Quarterly》1996,61(10):1488-1495
Alpha 1 antitrypsin deficiency (AT) is an autosomal recessive disease associated with chronic liver disease in adults and children and emphysema in adults. The disease is one of the most common inherited disorders of the Caucasian population of North Europe and North America and is the most common genetic reason for pediatric orthotopic liver transplantation (OLTx), although it is a rare indication in adults. The natural history of the disease is unpredictable and the pathogenesis of the liver injury unclear. Thirty-five patients with histologically apparent alpha 1 AT accumulation in the liver (22 adults, 13 children) have been transplanted in this center. Clinical features were correlated with the pretransplant phenotype, serum alpha 1 antitrypsin levels and potential precipitating factors. All children were PiZZ homozygotes, most of whom had presented with neonatal hepatitis. The majority of adult patients were heterozygotes presenting with portal hypertension and liver cirrhosis. Current one-year posttransplant survival figures are 73% for adults and 87.5% for children. Replacement of the cirrhotic liver results in acquisition of the donor phenotype, a rise in serum levels of alpha 1 antitrypsin, and apparent prevention of associated disease. 相似文献
10.
Seung-Yeop Kwak 《应用聚合物科学杂志》1995,55(12):1683-1690
The structural changes of poly(vinyl chloride) (PVC) plastisols during mixing of PVC with a plasticizer was investigated; as the temperature was increased, the system was found to transform from a suspension of solid particles in a liquid medium to a swollen gel and ultimately to a fused homogeneous matrix. The dynamic viscoelastic measurements were utilized to continuously monitor the changes of moduli under a controlled heating rate, employing a mechanical spectrometer. Characteristic changes in the viscoelastic behavior were associated with changes in particulate morphology as observed with a scanning electron microscope (SEM). Both viscoelastic and morphological observations were shown to provide details of structural changes in conjunction with the behavior of the PVC–plasticizer interaction, enabling a qualitative discrimination of the gelation and fusion processes. An in situ small-angle light-scattering (SALS) method was performed to make a quantitative estimate for the swollen particles of PVC while they were in the progress of gelation and fusion. From the manner of increase in correlation distances, along with the changes in viscoelastic moduli and morphology, the swelling behavior of the particulate structures were examined on the quantitative basis and brief insight into the complex behavior of the PVC–plasticizer interaction began to be unfolded. © 1995 John Wiley & Sons, Inc. 相似文献