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The Interactive Whiteboard (IWB) is now a common technological artefact in Swedish preschools and schools. This study examines preschool teachers’ thinking behind the embedding of IWB in the early years’ mathematics classroom and how preschool teachers structure their mathematical activities when using IWB. Two complementary empirical studies, that is, interviews and video observations, were conducted with four preschool teachers. The findings demonstrate that (just) having a positive attitude to technological artefacts like IWB is less likely to enrich the learning environment and lead to pedagogical change. This suggests that teachers’ IWB use is mostly informed by their pedagogical knowledge.  相似文献   
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In accordance with the two-step hypothesis of T cell activation and the observation that stimulation through the T cell receptor (TCR) alone may lead to anergy, we focused on the introduction of co-stimulatory signaling to this type of receptors to achieve optimal activation. Enhanced mRNA and cell surface receptor expression via the co-stimulatory gene fragment (OX40) was confirmed by RT-PCR and flow cytometry. Inclusion of the OX40 co-stimulatory signaling region in series with the TCR led to enhanced antigen-induced IL-2 production after stimulation by MUC1-expressing cancer cell lines as compared to the chimeric receptor without OX40. Moreover, with the aim of maintaining high efficiency, while providing a means of controlling any possible unwanted proliferation in vivo, a regulation system was used. This controls the dimerization of a membrane-bound caspase 8 protein. Toward that goal, pFKC8 and CAR constructs were co-transfected into Jurkat cells, and the level of apoptosis was measured. 24 h after addition of the dimerizer, a 91% decrease in transfected cells was observed.  相似文献   
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In order to develop a possible C-X-C chemokine receptor type 4 (CXCR4) imaging agent for oncological scintigraphy, [67Ga]-labeled 1,1′-[1,4-Phenylene-bis(methylene)]bis(1,4,8,11-tetraazacyclotetradecane) ([67Ga]-AMD3100) was prepared by using [67Ga]GaCl3 and AMD-3100 for 2 h at 50 °C (radiochemical purity: >95% ITLC, >99% HPLC, specific activity: 1800–2000 TBq/mmol) in acetate buffer. The stability of the complex was checked in the presence of human serum (37 °C) and in the final formulation for four days. The biodistribution of the labeled compound in the vital organs of wild type Sprague-Dawley rats was determined and compared with that of the free Ga3+ cation up to 48 h. Considering the spleen as the target organ, the best target:non target ratios were obtained 48 h post-injection (spleen:blood ratio; 14.5 and spleen:muscle ratio; 88.4). Initial SPECT images and biodistribution results in the wild type rats matched each other and demonstrated rapid washout of the tracer from the urinary tract. SPECT images in human breast carcinoma-bearing mice demonstrated a detectable tumor uptake in 48 h post-injection.  相似文献   
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We aimed to assess the acute cardiopulmonary effects of a 100-mg oral single dose of sildenafil in patients with idiopathic pulmonary hypertension (IPAH) using a well-validated but less-used noninvasive echocardiographic method for the measurement of both systolic and diastolic pulmonary artery pressure (PAP), by tricuspid regurgitation (TR) velocity curve analysis. We studied 12 consecutive patients with IPAH (10 patients with New York Heart Association functional class III, and 2 patients with functional class II). A 100-mg oral single dose of sildenafil was added to previous medications of all patients and its immediate effects were evaluated 1, 5, and 12 h after treatment. Using paired analysis, administration of a 100-mg oral single dose of sildenafil led to a significant reduction in mean PAP and a remarkable increase in pulmonary acceleration time (PAT) 1 h after treatment (P = 0.000; 95% confidence interval [CI] 18.99–26.00 and P = 0.005; 95% CI −12.89 to −2.95, respectively). In addition, although the right heart dimensions (right atrium and right ventricle) showed a trend toward improvement, the differences were not statistically significant (P = 0.13 and P = 0.08, respectively). Our results demonstrated that Doppler examination of TR alone can be easily used for the estimate of systolic and diastolic PAP in patients with IPAH. This study also shows that sildenafil is the only drug given orally that can evaluate the vasodilatory capacity of the pulmonary vascular bed in patients with IPAH, with promising effects on mPAP and PAT in these patients.  相似文献   
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The concentration-profile of the antineoplastic agent carboplatinum in serum and intraperitoneal-fluid (IPF) of six female patients was studied. Pharmacokinetical analysis showed a rapid distribution-phase between both compartments within the first 4h after administration (t1/2 serum = 4.4 h, t1/2 IPF = 3.3 h). Elimination half-life of carboplatinum of 20.3 h from the blood-vessel-system was significantly higher than from the intraperitoneal-compartment (t1/2 = 10.6 h). The relative bioavailability (calculated as AUC-values) was at least 6 times higher for the IPF than for serum within the first 48 h. 98% of measured amount were eliminated from both compartments within this time. The desired high IPF-levels support this route of administration.  相似文献   
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AIM: To investigate the effect of hyaluronidase use on the quality of sub-Tenon's anaesthesia for phacoemulsification. METHODS: This was a randomized, double-blind clinical trial which was conducted at Nikookari Eye Hospital for 5 months. Forty-two eyes of candidates for phacoemulsification under sub-Tenon's anaesthesia were randomly allocated to two equal groups and received either 2 mL of lidocaine 2% solution with (LH), or without (L) addition of hyaluronidase (150IU/mL). Akinesia was assessed 15 minutes after sub-Tenon’s injection. Patients and surgeon’s satisfaction, as well as the postoperative pain (the visual analogue scale, VAS) were investigated after operation. The contingency tables (including the Chi-square or Fisher's exact tests, when appropriate) and parametric analysis (the independent samples t test) were used for statistical analysis. RESULTS: Complete akinesia (33.3% vs 4.8%, P=0.04), as well as the patients (85.7% vs 57.1%, P=0.04) and surgeon’s satisfaction (87.5% vs 52.4%, P=0.02) were significantly more frequent in LH than in L group. The mean VAS was significantly lower in the same group (1.90±1.45 vs 3.00±1.55, P=0.04). CONCLUSION: Addition of hyaluronidase to lidocaine solution for sub-Tenon's anesthesia significantly improves the ocular akinesia, enhances the intra-operative patients and surgeons' satisfaction, and attenuates the postoperative pain.  相似文献   
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