Changes in self-efficacy resulting from unaided attempts to quit smoking.

Investigated changes in smoking self-efficacy as a result of successful and unsuccessful quit attempts. The sample consisted of 182 smokers (aged 19–70 yrs) who planned to quit smoking without professional assistance. Prior to a self-selected quit date, smoking self-efficacy was assessed. Quit status was determined 1, 6, and 12 mo after the quit date. Self-efficacy was reassessed at the 12-mo follow-up. At 12 mo the sample consisted of 44 quitters, 24 continuous smokers, 102 relapsers, and 12 Ss whose smoking status was uncertain. Self-reports of cessation were corroborated by collateral report and confirmed by saliva cotinine analysis. As predicted, quitters increased their self-efficacy, and continuous smokers decreased their self-efficacy from the prequit baseline to the 12-mo follow-up. Relapsers' self-efficacy also dropped significantly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in oral ethanol self-administration patterns resulting from ethanol concentration manipulations

A variety of initiation procedures have been used to develop oral ethanol consumption. Using the sucrose-substitution procedure, oral self-administration of ethanol-water solutions with ethanol concentrations as high as 40% can be initiated in food- and fluid-sated rats. An important question for these models is the relationship between ethanol concentration and self-administration patterns after initiation. This study examined the differential patterns of ethanol self-administration maintained by a range of ethanol solutions (10 to 30%) over a 5-week period, compared with rats maintained on 10% ethanol for 5 weeks. In 43 male Long Evans rats, the sucrose-substitution procedure was used to initiate responding maintained by 10% ethanol on a Fixed Ratio 4 schedule of reinforcement. The ethanol concentration presented was then increased to 30% in stepwise fashion and then returned to 10% [Ethanol Concentration Manipulation (ECM) group, n = 32], or 10% ethanol was maintained as the reinforcer for 5 weeks [Control (Con) group, n = 11]. Significant increases in ethanol intake and decreases in responding were associated with increased ethanol concentration. Although no overall differences in total session responding were observed in either group between week 1 and week 5 (10E vs. 10E), examination of changes in initial low responders of the ECM group revealed significant increases in responding that were not observed in the initial low responders of the Con group. Significant increases in momentary response rates were observed on both the ECM and Con groups, independent of the ethanol concentration presented. Increases in response rate in the ECM group were the result of increases in initial low rate and high rate responders; however, the increased response rates in the Con group were the result of increases only in the initial low rate responders. These data suggest that the ECM procedure can aid in the initiation of ethanol self-administration and may be particularly useful in rats of heterogeneous stock.     

Changes in medical students' perceptions of family practice resulting from a required clerkship

BACKGROUND: Career choice research has shown that exposing medical students to family medicine, through a special medical school emphasis or a required clerkship, correlates with an increased rate of selection of family practice. It has been hypothesized that actual exposure to family medicine mitigates the negative stereotypes held by many medical students. METHODS: This study used a qualitative strategy to examine how a family medicine clerkship altered medical students' perceptions and attitudes toward this specialty. A series of 12 focus groups were conducted with the students who had just completed a required family medicine junior core clerkship at our institution. RESULTS: Focus group findings confirmed the existence of negative stereotypes about family practice among medical students and provided additional information on their nature and origins. In addition, student comments indicated that a third-year family medicine clerkship experience dispelled this negative stereotyping and instilled in students a greater respect for and interest in family practice. CONCLUSION: Third-year clerkships can enhance students' perceptions of family practice by dispelling negative stereotypes and by providing medical students with a more accurate portrayal of the nature of this primary care specialty.     

Changes in mitochondrial function resulting from synaptic activity in the rat hippocampal slice

Digital imaging microfluorimetry was used to visualize changes in mitochondrial potential and intracellular Ca2+ concentration, [Ca2+]i, in thick slices of rat hippocampus. Electrical activity, especially stimulus train-induced bursting (STIB) activity, produced slow, prolonged changes in mitochondrial potential within hippocampal slices as revealed by fluorescence measurements with rhodamine dyes. Changes in mitochondrial potential showed both temporal and spatial correlations with the intensity of the electrical activity. Patterned changes in mitochondrial potential were observed to last from tens of seconds to minutes as the consequence of epileptiform discharges. STIB-associated elevations in [Ca2+]i were also prolonged and exhibited a spatial pattern similar to that of the mitochondrial depolarization. The mitochondrial depolarization was sensitive to TTX and glutamate receptor blockers ([Mg2+]o and CNQX or DNQX plus D-AP-5) and to the inhibition of glutamate release by activation of presynaptic NPY receptors. The monitoring of mitochondrial potential in slice preparations provides a new tool for mapping synaptic activity in the brain and for determining the roles of mitochondria in regulation of brain synaptic activity.     

Changes in forage quality, ingestive mastication, and digesta kinetics resulting from switchgrass maturity

Five maturities of switchgrass hay harvested at 14-d intervals (vegetative through 20% heading) were fed to Hereford steers (297 kg) in a 5 x 5 Latin square. Relationships with switchgrass maturity were negative and quadratic (P < .05) for DMI and cubic (P < .05) for digestible DMI. Declines in apparent digestibilities of DM, ADF, and cellulose were cubic (P < .05), whereas these were quadratic (P < .05) for NDF, hemicellulose, and CP. Whole masticates from the least, mid, and most mature hays showed linear (P < .05) declines in DM concentration and IVDMD with increasing maturity, whereas NDF concentrations increased linearly (P < .05). Mean retention time of gastrointestinal DM increased linearly (P < .01) from 64 to 94 h from the least to the most mature hay, and the associated rate of passage declined linearly (P < .01) from 3.3 to 2.1%/h. Sieving of masticate DM showed a reduced proportion of large particles (> or = 2.8 mm) and an increased proportion of small particles (< or = .5 mm) with advancing forage maturity. More than 94% of the sieved fecal DM passed a 1.0-mm sieve, but particle sizes showed the same relationship with forage maturity as noted for masticate DM. This occurred despite the comminution from the rumination and digestive processes.     

The carry-through of residues of maleic hydrazide from treated potatoes, following manufacture into potato crisps and ''jacket'' potato crisps

Primary nodal drainage basins in melanoma of the head and neck are often unpredictable. The ear is a notorious example of an anatomic site with ambiguous patterns of lymphatic drainage. Preoperative lymphoscintigraphy has recently emerged as one modality to assist in identifying clinically relevant nodes. We propose that the addition of intraoperative lymph node mapping techniques that utilize radioactive tracers ("intraoperative lymphoscintigraphy") can increase the accuracy of identifying sentinel nodes and help to determine which patients may benefit from a complete neck dissection. This report demonstrates the ambiguity in identifying drainage patterns in melanoma of the ear and offers a reliable method of sentinel lymph node mapping. This report also addresses current issues regarding treatment protocols of patients with micrometastatic disease in the periauricular region.     

Changes in steady-state conformational equilibrium resulting from cytoplasmic mutations of the Na,K-ATPase alpha-subunit

Mutations comprising either deletion of 32 amino acids from the NH2 terminus (alpha1M32) or a Glu233 --> Lys substitution in the first M2-M3 cytoplasmic loop (E233K) of the alpha1-subunit of the Na, K-ATPase result in a shift in the steady-state E1 left arrow over right arrow E2 conformational equilibrium toward E1 form(s). In the present study, the functional consequences of both NH2-terminal deletion and Glu233 substitution provide evidence for mutual interactions of these cytoplasmic regions. Following transfection and selection of HeLa cells expressing the ouabain-resistant alpha1M32E233K double mutant, growth was markedly reduced unless the K+ concentration in the culture medium was increased to at least 10 mM. Marked changes effected by this double mutation included 1) a 15-fold reduction in catalytic turnover (Vmax/EPmax), 2) a 70-fold increase in apparent affinity for ATP, 3) a marked decrease in vanadate sensitivity, and 4) marked (approximately 10-fold) K+ activation of the Na-ATPase activity measured at micromolar ATP under which condition the E2(K) --> --> E1 pathway is normally (alpha1) rate-limiting and K+ is inhibitory. The decrease in catalytic turnover was associated with a 5-fold decrease in Vmax and a compensatory approximately 3-fold increase in expressed alpha1M32E233K protein. In contrast to the behavior of either alpha1M32 or E233K, alpha1M32E233K also showed alterations in apparent cation affinities. K'Na was decreased approximately 2-fold and K'K was increased approximately 2-fold. The importance of the charge at residue 233 is underscored by the consequences of single and double mutations comprising either a conservative change (E233D) or neutral substitution (E233Q). Thus, whereas mutation to a positively charged residue (E233K) causes a drastic change in enzymatic behavior, a conservative change causes only a minor change and the neutral substitution, an intermediate effect. Overall, the combined effects of the NH2-terminal deletion and the Glu233 substitutions are synergistic rather than additive, consistent with an interaction between the NH2-terminal region, the first cytoplasmic loop, and possibly the large M4-M5 cytoplasmic loop bearing the nucleotide binding and phosphorylation sites.     

Effects of dehulling, cooking and storage conditions on protein quality and digestibility of soybeans

A monoclonal antibody against tetrodotoxin was produced. Tetrodotoxin coupled with keyhole limpet hemocyanin was used as an immunogen to BALB/c mice. These mice had no clinical signs for the toxicity of tetrodotoxin during the immunization. The reason may be that the guanidyl group of tetrodotoxin which is an important group for the toxicity was hidden by coupling with keyhole limpet hemocyanin. The monoclonal antibody was highly specific for tetrodotoxin and had no cross-reaction to tetrodotoxin derivatives, paralytic shellfish toxins, keyhole limpet hemocyanin and crude proteins from various organs of puffer fish. Also, tetrodotoxin was neutralized in vitro by this antibody. From the fact that the structural difference between tetrodotoxin and anhydro-tetrodotoxin is recognized by this antibody, it was suggested that this antibody reacted with the OH-groups on C-4 and/or C-9 of tetrodotoxin. In addition, the results from immunization and neutralization tests demonstrated that tetrodotoxin became non-toxic even when one of the active groups of tetrodotoxin was coupled by a molecule.     

Changes in the reactivity of the sensorimotor cortex resulting from the treatment of patients with depressive disorders

Changes in the mu-rhythm power in response to sound (non-specific reactivity, NR) and related with the actual and imaginary movement with the right and left hand in response to sound (specific reactivity, SR) were studied in 38 right-handed patients with subdepressive psychogenic (PD) and endogenous (ED) disorders before and after successful complex treatment (pharmacotherapy and acupuncture) in comparison with 23 healthy subjects. The successful treatment was found to be accompanied by a certain extent of normalization of the disturbed SR which was different in PD and ED. The more complete recovery of the normal reactions in PD was mainly accounted for by the relative decrease in the NR and increase in the SR. The ED treatment predominantly modified the SR. Substantial reorganization of interhemispheric relations during movements in the PD patients resulted in disappearance of the abnormal ipsilateral reactions and transition to the contralateral reactions of the sensorimotor cortex.     

Changes in the calpains and calpastatin during postmortem storage of bovine muscle

Changes in activity and protein status of micro-calpain, m-calpain, and calpastatin in bovine semimembranosus muscle during the first 7d of postmortem storage were monitored by using assays of proteolytic activity, SDS-polyacrylamide gel electrophoresis, and Western blot analysis. Extractable m-calpain activity changed slightly during the first 7d after death (decreased to 63% of at-death activity after 7d), whereas extractable calpastatin activity decreased substantially (to 60% of at-death activity after 1d and to 30% of at-death activity after 7d of postmortem storage) during this period. Extractable micro-calpain activity also decreased rapidly (to 20% of at-death activity at 1d and to less than 4% of its at-death activity at 7d after death) during postmortem storage. Western blot analysis showed that the 80-kDa subunit of m-calpain remained undegraded during the first 7d after death but that the 125- to 130-kDa calpastatin polypeptide was gone entirely at 7d after death. Hence, the calpastatin activity remaining at 7d originates from calpastatin polypeptides that are 42 kDa or smaller. The 80-kDa micro-calpain subunit was almost entirely in the 76-kDa autolyzed form at 7d after death; this form is proteolytically active in in vitro systems, and it is unclear why the postmortem, autolyzed micro-calpain is not active. Over 50% of total muscle micro-calpain is tightly bound to myofibrils 7d after death; this micro-calpain is also nearly inactive proteolytically. Unless postmortem muscle contains some factor that enables micro-calpain in this muscle to be proteolytically active, it is not clear whether micro-calpain could be responsible for any appreciable postmortem myofibrillar proteolysis.     

Structural and electronic effects resulting from metal-flavin ligation

The synthesis and physical properties of a model metalloflavin complex, [(10-methylisoalloxazine)-(NH3)4Ru](PF6)2 . 2H2O are reported. The structure of this stable, enantiomeric compound was elucidated by x-ray diffraction methods with a final unweighted R value of 0.054. Crystals belong to the triclinic space group P1 with unit cell dimensions: a = 9.631, b = 10.618, c = 13.216 A; alpha = 113.86, beta = 100.19, gamma = 94.12 degrees. Chelation of the metal ion to the flavin occurs at the N(5) and O(4) positions, with a short Ru-N(5) bond distance of 1.979 A. Steric and electronic factors induce a 9.9 degrees bend in the isoalloxazine ring system and a significant lengthening of the C(4a)-N(5) bond. The flavin absorption bands shift significantly toward lower energy on complexation and a new band occurs at 617 nm. These absorptions are pH-dependent and pK alpha values for the complex are 0.6 and 7.4. The spectra of this complex exhibit similarities to that of metallosemiquinone species and arguments are made that a significant amount of electron density is donated to the pi-system of the flavin. Proton NMR studies suggest enhanced electron density at the N(10) position, probably occurring through backbonding interactions. Cyclic voltametry studies are also consistent with substantial metal to ligand pi-electron donation, since it is significantly more difficult to reduce the coordinated flavin relative to the free ligand under the same conditions. Moreover, the complexed flavin accepts electrons in 1-electron rather than 2-electron steps. Spectroelectrochemical studies on the 1-electron reduced complex indicate a similarity with other M(II)-F1 species.     

钢中摩擦磨损白层的研究现状

综述了国内外对白层的研究现状,指出了当前白层研究中存在的分歧和争论,分析归纳了表面白层的特征和形成机制,重点讨论了钢轨运行过程中白层的组织结构及形成机制,提出了今后的研究方向.同时用扫描电镜对车轮钢切削白层和钢轨钢中的白层进行观察分析.结果表明,车轮钢切削加工和钢轨运行时,表面组织均发生动态的塑性变形和再结晶,原奥氏体晶粒细化,在随后的冷却的过程中形成马氏体.     

Changes of bromopropylate and carbendazim residues during processing of apples into apple puree

Surface perikaryal labeling on immunohistochemical assay for synaptophysin (SYN)--a glycoprotein component of synaptic vesicle membranes--has been posited to distinguish the neoplastic neuronal elements of gangliogliomas from native central nervous system neurons overrun by gliomas invasive of gray matter. To assess the validity of this criterion in the evaluation of intramedullary neoplasms, we screened formalin-fixed, paraffin-embedded sections from 35 histologically unremarkable spinal cords (removed at autopsy) using commercially available monoclonal antibodies to SYN. All specimens exhibited anti-SYN reactivity, which was confined to gray matter, and all evidenced the concentrated deposition of reaction product along the perikarya of large neurons in the anterior horns, Clarke's columns, and intermediolateral cell columns. A majority (23 specimens) contained neurons completely outlined by reaction product rings comparable to those depicted as being pathognomonic of neuronal neoplasia. This phenomenon presumably reflects the rich complement of axosomatic synapses documented in fine structural studies of the normal spinal cord. Surface perikaryal labeling for SYN is not restricted to the neoplastic neurons of ganglion cell tumors and should be cautiously interpreted, particularly when neurosurgical material derives from the spinal cord.     

Changes in the quality parameters of virgin olive oil from the Lower Aragon area of Teruel during the storage

Virgin olive oil from the Lower Aragon area, despite its excellent alimentary qualities, is a product which is sensitive to high temperatures and sunlight. In this work, during a 10 months storage period, a study was made of the variation in acidity, the index of peroxides, K270 and alpha-tocopherol in two olive oils, one of which was made from fresh olives by means of the traditional oil mill methods, a discontinuous method, and the other oil was obtained from pre-fermented olives by means of the modern centrifugation method, or the continuous method. These parameters were measured in both types of oil, in samples stored at room temperature (variable) and others stored at a constant temperature (20 degrees C + 1 degree C). A sub-sample of each of these was stored in the dark, and another in the presence of light. The variation of the parameters allows us to see the variation which takes place with regard to the nutritive properties of the oil ashen this is stored.     

Dissociation of letter and picture naming resulting from callosal disconnection

BACKGROUND: Detailed mapping of the corpus callosum for functional fractionation in humans remains incomplete. OBJECTIVE: To examine separable interhemispheric transfer of visual information by callosal fibers, especially in the splenium. METHODS: We examined callosal disconnection signs in a 14-year-old boy with a lesion confined to the posterior part of the splenium and reviewed reported cases with callosal lesions. RESULTS AND CONCLUSION: The patient presented with left hemialexia as the only manifestation of callosal disconnection syndrome. The only difficulty demonstrated was in reading aloud or copying letters, which were presented tachistoscopically to the left visual field, with his right hand. He could copy letters presented to his left visual field with his left hand, however. Therefore, left hemialexia was not due to hemiamblyopia or hemineglect. There was no anomia for pictures and colors in the left visual field. MRI revealed that the lesion was limited to the ventroposterior end of the splenium. Review of 40 reported patients with callosal lesions suggests that the anterior to middle part of the splenium is involved in transferring picture information from the language-nondominant hemisphere to the language-dominant hemisphere and that the ventroposterior part is involved in transferring letter information.     

Tryptophan residues in alpha-galactosidase from Trichoderma reesei

Tryptophan residues in alpha-galactosidase were modified with bromosuccinimide. The fact that galactose, a specific inhibitor of alpha-galactosidase, does not prevent this modification demonstrates that tryptophan residues are not located in galactose binding sites. Analysis of the inactivation kinetics revealed two groups of Trp residues (8.5 and 7.5 residues) with different accessibility for N-bromosuccinimide. We studied specific quenching of alpha-galactosidase fluorescence resulting from modification of an sulfhydryl group in the active site of the enzyme with Hg2+ and Ag+ ions. The specific quenching is due to conformational changes of the enzyme. Forster's radii were determined for various protein--chromophore complexes. Dynamic quenching of alpha-galactosidase fluorescence was investigated. To describe abnormal dynamic quenching in alpha-galactosidase, a modification of the Stern--Volmer equation is suggested.     

Evaluation of outcome improvement resulting from threats and appeals.

In a simulated industrial setting 90 college students performed a clerical task, believing that their pay was being determined by a peer allocator. After being treated inequitably, Ss were able either to threaten the (fictitious) allocator or appeal to fairness principles, or they had no say ("mute" condition). During a 2nd series of pay periods, Ss' pay either remained constant, improved such that they and the allocator received equal shares, or improved such that Ss received more than the allocator ("comprehension" condition). The total pay was identical in all conditions and created a context of overall inequity. Increased satisfaction and perceived fairness were observed with improved outcomes in both the mute and the threat conditions. In the appeal conditions, satisfaction and perceived fairness were highest in the equality cell. Results are interpreted in terms of relative deprivation. Implications for responses of recipients in ameliorative social programs are presented. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)