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排序方式: 共有85条查询结果,搜索用时 15 毫秒
41.
Mustafa El-Khatib Carolin Tepe Brigitte Senger Maxine Dibué-Adjei Markus Johannes Riemenschneider Walter Stummer Hans Jakob Steiger Jan Frédérick Cornelius 《International journal of molecular sciences》2015,16(5):9936-9948
Objective: Five-aminolevulinic acid (5-ALA)-induced porphyrins in malignant gliomas are potent photosensitizers. Promising results of ALA-PDT (photodynamic therapy) in recurrent glioblastomas have been published. Recently, 5-ALA-induced fluorescence was studied in meningioma surgery. Here, we present an experimental study of ALA-PDT in an in vitro model of primary meningioma cell lines. Methods: We processed native tumor material obtained intra-operatively within 24 h for cell culture. Epithelial membrane antigen (EMA) immunohistochemistry was performed after the first passage to confirm that cells were meningioma cells. For 5-ALA-PDT treatment, about 5000 cells per well were seeded in 20 wells of a blank 96-well plate. Each block of 4 wells was inoculated with 150 µL of 0, 25, 50 and 100 µg/mL 5-ALA solutions; one block was used as negative control without 5-ALA and without PDT. Following incubation for 3 h PDT was performed using a laser (635 nm, 18.75 J/cm2). The therapeutic response was analyzed by the water soluble tetrazolium salt (WST-1) cell viability assay 90 min after PDT. Results: 5-ALA-PDT was performed in 14 primary meningioma cell lines. EMA expression was verified in 10 primary cell cultures. The remaining 4 were EMA negative and PDT was without any effect in these cultures. All 10 EMA-positive cell lines showed a significant and dose-dependent decrease in viability rate (p < 0.001). Cell survival at 5-ALA concentrations of 12.5, 25, 50 and 100 μg/mL was 96.5% ± 7.6%, 67.9% ± 29.9%, 24.0% ± 16.7% and 13.8% ± 7.5%, respectively. For the negative controls (no 5-ALA/PDT and ALA/no PDT), the viability rates were 101.72% ± 3.5% and 100.17% ± 3.6%, respectively. The LD50 for 5-ALA was estimated between 25 and 50 µg/mL. Conclusion: This study reveals dose-dependent cytotoxic effects of 5-ALA-PDT on primary cell lines of meningiomas. Either 5-ALA or PDT alone did not affect cell survival. Further efforts are necessary to study the potential therapeutic effects of 5-ALA-PDT in vivo. 相似文献
42.
Rosado James; Sigmon Stacey C.; Jones Hendree E.; Stitzer Maxine L. 《Canadian Metallurgical Quarterly》2005,13(1):41
This study examined the relative reinforcing potency of vouchers and cash in drug-dependent pregnant women (N = 48) across voucher values ($10, $50, and $100) by use of a series of choices to understand how exchange-delay features of voucher reinforcers influence their reinforcing potency compared with cash. The study also examined a no delay vs. 2-day delay of the cash alternative. Generally, cash was selected at 80%-90% of voucher face values. Vouchers were also discounted less when a 2-day delay was imposed on the cash option compared to the immediately available cash. These results suggest that voucher discounting does occur among patients in drug treatment. However, vouchers retain 80%-90% of their cash value and thus remain relatively potent reinforcers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
43.
Petry Nancy M.; Roll John M.; Rounsaville Bruce J.; Ball Samuel A.; Stitzer Maxine; Peirce Jessica M.; Blaine Jack; Kirby Kimberly C.; McCarty Dennis; Carroll Kathleen M. 《Canadian Metallurgical Quarterly》2008,76(6):1076
Human subjects protection policies developed for pharmaceutical trials are now being widely applied to psychosocial intervention studies. This study examined occurrences of serious adverse events (SAEs) reported in multicenter psychosocial trials of the National Institute on Drug Abuse Clinical Trials Network. Substance-abusing participants (N = 1,687) were randomized to standard care or standard care plus either contingency management or motivational enhancement. Twelve percent of participants experienced 1 or more SAEs during the 27,198 person-weeks of follow-up. Of the 260 SAEs recorded, none were judged by the data safety monitoring board to be study related, and there were no significant differences between experimental and control conditions in SAE incidence rates. These data underscore the need to reconsider the rationale behind, and appropriate methods for, monitoring safety during psychosocial therapy trials. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
The research literature abounds with articles about distance learning from the perspectives of students, faculty, and administrators. Most of these articles discuss the details of transitioning to on‐line learning environments. Research is beginning to pay attention to quality issues in distance learning. This article discusses a three‐phase developmental study conducted in a graduate school. Students were asked to brainstorm and develop a set of quality indicators. These indicators were ranked by a second group of students. Then the indicators were given to a group of faculty for another ranking. In this study it was shown that there was a very great agreement on the relative importance of the various potential indicators of quality in courses delivered via an on‐line medium. 相似文献
45.
In individual interviews, 80 children from ages 4 to 8 yrs predicted which of 5 emotions they would feel, and how intensely, to 15 affect-laden situations. The results indicate that responses involve 3 dimensions of emotion cognition (intensity, multiplicity, and valence) that emerge in a developmental sequence. Four-year-olds predict experiencing 1 emotion of varying intensity to a situation (Level A). They also predict experiencing multiple emotions, but at maximum intensity and the same valence (Level B). By age 6, children predict experiencing multiple emotions of varying intensity but the same valence (Level C). Children around age 8 predict multiple emotions of varying intensity and opposite valence (Level D). The number of emotions experienced at one time and accuracy also increased with development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
Gail M. Bornhorst Maxine J. Roman Shane M. Rutherfurd Betty J. Burri Paul J. Moughan R. Paul Singh 《Journal of food science》2013,78(11):H1807-H1813
Almonds are an important dietary source of lipids, protein, and α‐tocopherol. It has been demonstrated that the physical form of almond kernels influences their digestion and absorption, but the role of thermal processes on the digestion of almonds has received little attention. The objectives of this study were to examine the gastric emptying and nutrient composition of gastric chyme from pigs (used as a model for the adult human) fed a single meal of either raw or roasted almonds over a 12‐h postprandial period (72 pigs total, 6 pigs at each diet–time combination). Concentrations of glucose, triacylglycerols, and α‐tocopherol in peripheral plasma during the 12‐h postprandial period were determined. For dry matter and lipid, the gastric emptying profile was not different between raw and roasted almonds. Roasting almonds also did not influence gastric pH, or plasma glucose or triacylglycerols levels. In contrast, the gastric emptying of protein was more rapid for raw almonds compared to roasted almonds (P < 0.01) and intragastric protein content exhibited segregation (P < 0.001) throughout the stomach, with raw almonds having a higher level of segregation compared to roasted almonds. Postprandial plasma α‐tocopherol levels were, on average 33% greater (P < 0.001) after consumption of raw almonds, most likely as a result of the higher concentration of α‐tocopherol in raw almonds compared to roasted almonds. Roasting of almonds did not influence the overall gastric emptying process, but did lead to differences in the distribution of protein in the stomach and to the gastric emptying of protein. 相似文献
47.
The effect of rooibos tea extract (RBTE 0%, 0.25%, 0.50%, 1.00%) as a natural antioxidant on the lipid and protein stability of ostrich droëwors (traditional South African dried sausage) after a 15 day drying period was investigated. The lipid stability of the droëwors increased with 0.25% RBTE having lower TBARS. The protein stability of the droëwors did not differ (P ≥ 0.05) between treatments. The heme–iron content did not differ (P ≥ 0.05) between the treatments and increased from day 0 to day 15. Drying resulted in a decrease in the total moisture content by 45% and a corresponding increase in all other components. There were no differences between the moisture, fat and ash contents between treatments within a specific day. The droëwors had high concentrations of oleic acid, palmitic acid and linoleic acid. The addition of RBTE also improved the sensory attributes and can thus be added and marketed as a natural flavourant from ‘out of Africa’ for a traditional South African meat product. 相似文献
48.
Discusses the lack of general awareness of women who have made major contributions to psychology. It is suggested that this lack of recognition is partially caused by the practice of appending initials only to the surnames of authors of tests and journal articles. Numerous examples are presented of women who developed tests (e.g., the Taylor Manifest Anxiety scale and the Bender Gestalt Test), wrote textbooks, and made major theoretical contributions to the study of human behavior. (59 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
49.
Goods-based contingency management interventions (e.g., those using vouchers or prizes as incentives) have demonstrated efficacy in reducing cocaine use, but cost has limited dissemination to community clinics. Recent research suggests that development of a cash-based contingency management approach may improve treatment outcomes while reducing operational costs of the intervention. However, the clinical safety of providing cash-based incentives to substance abusers has been a concern. The present 16-week study compared the effects of goods-based versus cash-based incentives worth $0, $25, $50, and $100 on short-term cocaine abstinence in a small sample of cocaine-dependent methadone patients (N = 12). A within-subject design was used; a 9-day washout period separated each of 8 incentive conditions. Higher magnitude ($50 and $100) cash-based incentives (checks) produced greater cocaine abstinence compared with the control ($0) condition, but a magnitude effect was not seen for goods-based incentives (vouchers). A trend was observed for greater rates of abstinence in the cash-based versus goods-based incentives at the $50 and $100 magnitudes. Receipt of $100 checks did not increase subsequent rates of cocaine use above those seen in control conditions. The efficacy and safety data provided in this and other recent studies suggest that use of cash-based incentives deserves consideration for clinical applications of contingency management, but additional confirmation in research using larger samples and more prolonged periods of incentive delivery is needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
Kenton O’Hara Tim Kindberg Maxine Glancy Luciana Baptista Byju Sukumaran Gil Kahana Julie Rowbotham 《Computer Supported Cooperative Work (CSCW)》2007,16(1-2):11-44
The augmentation of visitor experiences with location-based technologies has been available for some time. Through in-depth
studies of users during these experiences the field is building a rich picture of user behaviour in relation to certain location-based
technologies. However, little work has explored the use of mobile camera phones and 2D barcodes on situated signs and their
properties as a way of delivering such augmented visitor experiences. In this paper we present a study of people engaged in
such a location-based experience at London zoo in which they use mobile camera phones to read 2D barcodes on signs at the
animal enclosures in order to access related content. Through the fieldwork we highlight the social and collaborative aspects
of the experience and how particular characteristics of the mobile phone and barcode technology shape these behaviours. The
paper also highlights some of the non-instrumental aspects of the location-based experience, in particular in relation to
the importance of collecting location-based content. We explore the social aspects of collecting as well as certain competitive elements it introduces
into people’s behaviour. This creates an interesting tension in that aspects of the application encourage cooperation and
sharing among the visitors whereas others encourage competition. In the course of presenting the fieldwork, we explore this
tension further. 相似文献