The effect of different beryllium (Be) contents on the microstructure evolution and mechanical properties of as-cast Zr-3Al-chiBe alloys (chi = 0, 0.4, 0.6, and 0.8 wt.%) was evaluated. X-ray ...diffraction and microscopic analysis showed that significant microstructural changes were caused due to the trace amount of Be in the as-cast Zr-3Al-chiBe alloy. On one hand, with the Be increased gradually from 0 wt.% to 0.8 wt.%, the shape of prior-beta grains gradually transformed from inerratic planar crystallization to irregular arborization. On the other hand, it would have an obvious effect on grain refinement with Be added. The average grain sizes of the prior-beta and alpha (the average length) phases exceeded 1000 and 100 mum, respectively, in the as-cast Zr-3Al alloy. Dramatically, with the addition of 0.4 wt.% Be, the average grain sizes of the prior-beta and alpha phases were decreased by more than 80% and 50%, respectively. Moreover, the average size of grain decreased with increased Be. The enhancement in nucleation rate and the growth restriction factor values of Zr-3Al-chiBe alloys with Be addition were responsible for the refinement of the prior-beta and alpha grains. In addition, the tensile strength and hardness of Zr-3Al-chiBe alloys gradually increased with the increased Be content. The decrease in the alpha grain size and the presence of Be sub(2)Zr particles played identically important roles in improving the tensile strength and hardness of alloys.
We examined the effects of intrathecal (i.t.) selective opioid receptor agonists in alleviating mechanical and cold allodynia in spinally injured rats. Both DAMGO ...(D-Ala2,N-Me-Phe4,Gly5-ol-enkephalin, a mu-opioid receptor agonist) and DPDPE (D-Phe2,D-Phe5-enkephalin, a delta-opioid receptor agonist) dose-dependently relieved the chronic allodynia-like behavior at doses selective for their respective receptors. The anti-allodynic effect of DAMGO and DPDPE was reversed by the selective mu- and delta-opioid receptor antagonists CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2) and naltrindole, respectively. In contrast, the selective kappa-opioid receptor agonist U50488H did not alleviate the allodynia-like behavior, but rather enhanced it. The anti-nociceptive and anti-allodynic effect of i.t. DAMGO was blocked by U50488H. Thus, activation of spinal mu- and delta-, but not kappa-opioid receptors produced anti-allodynic effect in this model of central pain. Drugs which act selectively on opioid receptor subtypes may be useful in managing chronic central pain of spinal cord origin.
The pharmacological actions of Uncaria alkaloids, rhynchophylline and isorhynchophylline extracted from Uncaria rhynchophylla Miq Jacks were reviewed. The alkaloids mainly act on cardiovascular ...system and central nervous system including the hypotension, brachycardia, antiarrhythmia, and protection of cerebral ischemia and sedation. The active mechanisms were related to blocking of calcium channel, opening of potassium channel, and regulating of nerve transmitters transport and metabolism, etc.
Type III secretion systems are complex nanomachines used for injection of proteins from Gram-negative bacteria into eukaryotic cells. Although they are assembled when the environmental conditions are ...appropriate, they only start secreting upon contact with a host cell. Secretion is hierarchical. First, the pore-forming translocators are released. Second, effector proteins are injected. Hierarchy between these protein classes is mediated by a conserved gatekeeper protein, MxiC, in Shigella. As its molecular mechanism of action is still poorly understood, we used its structure to guide site-directed mutagenesis and to dissect its function. We identified mutants predominantly affecting all known features of MxiC regulation as follows: secretion of translocators, MxiC and/or effectors. Using molecular genetics, we then mapped at which point in the regulatory cascade the mutants were affected. Analysis of some of these mutants led us to a set of electron paramagnetic resonance experiments that provide evidence that MxiC interacts directly with IpaD. We suggest how this interaction regulates a switch in its conformation that is key to its functions.
Motivation is the impetus for patients to seek orthodontic treatment, affecting adherence, treatment outcomes, and satisfaction. The aim of this study was to assess the motivation of adult female ...patients seeking orthodontic treatment, and classify the patients according to their motivations.
This study used Q-methodology as the main tool. Q-samples were collected and categorized (35 items). Forty-two adult female patients were interviewed before treatment as the P-sample, and their responses were categorized into the Q-methodology grid. Participants were asked to rank-order a set of 35 statements (Q-sample) from "agree most" to "disagree most" (Q-sorting). The finished Q-grids were analyzed using PQ method 2.35.
Four main factors were identified based on how adult female patients ranked statements: factor 1, patients who focus on their self-perception of their appearance; factor 2, patients who are concerned about the esthetics and function of their teeth; factor 3, patients who are easily influenced by others; factor 4, patients who want to improve their confidence and avoid negative thoughts caused by their teeth. The remaining patients who had other views did not match any of the above four groups.
The motivations of adult female patients seeking orthodontic treatment are complex. This study found that most adult female patients fell into one of four typical factor groups. Our findings may improve the adherence of adult female patients by developing a more ideal treatment program.
This study was conducted to establish a feasible intraperitoneal xenograft model in nude mice which mimicked the dynamic progression of human ovarian cancer and to explore its potential for ...preclinical trials. A human ovarian tumor line SKOV3 was originally injected s.c. to develop tumors; then the tumors were harvested and minced into small particles for i.p. inoculation in three groups of nude mice which would be monitored consecutively. The intraperitoneal carcinomatosis and relevant organs were collected for histopathological dynamic comparison and CA125 immunohistochemical staining 7, 21 and 49 days after inoculation. An additional experiment with cisplatin sensitivity test was performed and tumor tissues were observed for apoptosis-Hoechst assay. The intraperitoneal carcinomatosis had a rapid progression which resulted in extensive dissemination on the peritoneal surfaces and invasion into abdominal lymph nodes, livers, pancreas and spleen. Tumor tissues revealed similar morphological features of primary tumor from which SKOV3 derived and part of in vivo tumor mass was positive for CA125. Cisplatin could significantly inhibit the intraperitoneal carcinomatosis growth. This model may provide a valuable platform to study the biological properties of ovarian cancer as well as to test new therapeutic strategies in preclinical trials.
The pyranocoumarins, (±)-3′-angeloyl-4′-acetoxy-
cis-khellactone, were isolated from Radix Peucedani, the dry root of
Peucedanum praeruptorum Dunn, through bioassay-guided fractionation. The chemical ...structure of pyranocoumarins was determined by mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. X-ray crystallography showed that there are eight molecules (i.e. two each of four conformers) in each unit cell with their optical activities equally cancelled out. The four conformers are 3′(
R)-angeloyl-4′(
R)-acetoxy-khellactone in two conformational forms, and 3′(
S)-angeloyl-4′(
S)-acetoxy-khellactone in two conformational forms. Pyranocoumarins caused apoptotic cell death with IC
50 of 41.9±2.8 and 17.3±8.2 μM for drug-sensitive KB-3-1 and multidrug resistant (MDR) KB-V1, respectively. The two- to threefold sensitivity difference between the two cell lines is interesting considering that the same ratio for doxorubicin is 50–300. Strong synergistic interactions were demonstrated when pyranocoumarins were combined with common anti-tumor drugs including doxorubicin, paclitaxel, puromycin or vincristine in MDR KB-V1 cell line, but not in drug-sensitive KB-3-1 cells. Pyranocoumarins increased doxorubicin accumulation in KB-V1 cells by about 25% after 6 h of incubation. Pyranocoumarins treatment for 24 h down-regulated the expression of P-glycoprotein in KB-V1 cells at both protein and mRNA levels. Pyranocoumarins also transiently reduced the cellular ATP contents in KB-V1 cells in a dose-dependent manner. Our results suggest that pyranocoumarins could be a potential MDR reversing agent.
Caffeine, used in many pain medications as an adjuvant analgesic, is an adenosine A
1 and A
2A receptor antagonist. Here we examined the effects of acute or chronic caffeine administration in rats ...after partial sciatic nerve injury. The hindpaw response to mechanical or cold stimulation was assessed following photochemically induced sciatic nerve injury which leads to hypersensitivity to these stimuli. Caffeine was administered i.p. acutely or in the drinking water chronically. The mechanical and cold hypersensitivity of sciatic nerve-injured rats was dose-dependently alleviated by acute systemic administration of caffeine (10–80
mg/kg). The effect of caffeine was, however, associated with side effects including locomotor stimulation or depression. Chronic oral administration (average daily doses 27.5
mg/kg/day or 61.5
mg/kg/day for 2 weeks) of caffeine starting at the time of nerve injury did not significantly affect the development of pain-like behaviors. Thus, acute, but not long term, caffeine intake reduced neuropathic pain state in nerve-injured rats, but only at very high doses. The potential hyperalgesic effect of chronic A
1 adenosine receptor blockade may have been compensated for by an antinociceptive effect of caffeine through antagonism of A
2A receptors and tolerance development.
To characterize sociodemographic variations in the prevalence of AD and VaD in China.
Data were collected in a 1997-1998, cross-sectional, door-to-door prevalence survey of 34,807 community residents ...ages > or =55 years in Beijing, Shanghai, Chengdu and Xian. Initial diagnoses of AD and VaD were assessed by clinicians using standardized protocols, according to the NINCDS-ADRDA and NINDS-AIREN criteria; diagnoses were confirmed after 6 months by repeating neuropsychological evaluations. Prevalence odds ratios were estimated in logistic models adjusting for survey design, age, and other sociodemographic factors.
We identified 732 prevalent cases of AD and 295 cases of VaD. Adjusting for all sociodemographic factors concurrently, prevalence odds of AD and VaD were higher in northern versus southern China. Age trends for AD appeared different in western and eastern China. AD also showed an age-adjusted elevation among women and, in the fully adjusted model, a gender education interaction indicating a female preponderance in the highest education group. North-south variation for VaD was age-dependent. In the fully adjusted model, for AD, widowed had significantly higher prevalence odds; for VaD, widowed persons and minorities had significantly lower prevalence odds; professionals had statistically significant and borderline lower prevalence odds for both VaD and AD; sales-service occupations had significantly lower odds for AD only.
We observed variations in prevalence for AD and VaD in different regions and demographic groups in China that persisted after controlling for potential confounding factors. Sociodemographic factors are probable surrogates for conditions such as lifestyle, environment, comorbidities, and life expectancy.
Muscle spindle density is extremely high in the deep muscles of the human neck. However, there is a paucity of information regarding the morphology and immunoreactivity of these muscle spindles. The ...objective of this study was to investigate the intrafusal fiber content and to assess the myosin heavy chain (MyHC) composition of muscle spindles from human deep neck muscles. In addition to the conventional spindles containing bag1, bag2, and chain fibers (b1b2c spindle), we observed a number of spindles lacking bag1 (b2c spindle) or bag2 (b1c spindle) fibers. Both bag1 and bag2 fibers contained slow tonic MyHCs along their entire fiber length and MyHCI, MyHCIIa, embryonic, and α-cardiac MyHC isoforms along a variable length of the fibers. Fetal MyHC was present in bag2 fibers but not in bag1 fibers. Nuclear chain fibers contained MyHCIIa, embryonic, and fetal isoforms with regional variations. We also compared the present data with our previous results obtained from muscle spindles in human biceps brachii and the first lumbrical muscles. The allotment of numbers of intrafusal fibers and the MyHC composition showed some muscle-related differences, suggesting functional specialization in the control of movement among different human muscles.
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