基于改进的自组织映射网络的化工过程故障分类辨识

将自组织映射网络(SOM)应用于化工过程故障数据的分类辨识,并采用粒子群优化(PSO)算法优化权重失真指数(LW D I),代替SOM的启发式训练算法,形成粒子群优化的SOM(PSO-SOM)分类算法。以某工厂甲醇合成反应器数据为研究对象,研究结果表明:对比基本SOM算法,PSO-SOM算法对复杂的故障数据能够得到较优的分类辨识结果,对甲醇合成生产中的故障诊断有非常显著的指导作用。     

Effect of the fragile X status categories and the fragile X mental retardation protein levels on executive functioning in males and females with fragile X

The effects of a fragile X disorder on executive function impairment were assessed in 144 extended families, which included individuals with fragile X premutation and full mutation and their relatives without fragile X. A modification of the maximum-likelihood estimators for pedigree data, as well as ordinal logistic regression, were used in data analysis. The most outstanding deficit, occurring especially in males, involved impaired capacity to use an intention to regulate purposeful behavior. This deficit occurred independently of general cognitive impairment but was related to depletion of fragile X mental retardation 1 gene protein product. The other executive function deficits were accounted for by the general cognitive impairment. Possible mechanisms of the effect of fragile X premutation on impairments of executive functioning are considered.     

Hyperfunctioning parathyroid tumours in patients with thyroid nodules. Sensitivity and positive predictive value of high-resolution ultrasonography and 99mTc-sestamibi scintigraphy

A series of 112 consecutive patients with primary hyperparathyroidism who underwent both high-resolution neck ultrasonography (US) and 99mTc-sestamibi/99mTc-pertechnetate subtraction scintigraphy (SS) prior to successful parathyroidectomy was reviewed. There were 29 (25.9%) men and 83 (74.1%) women, with a median age of 58 years (range 13-78 years). Patients were divided into two groups, according to the preoperative US findings: group A (87 patients, 77.7%) without thyroid diseases, and group B (25 patients, 22.3%) with either multinodular goitre or a solitary nontoxic thyroid nodule. In group B patients partial or total thyroidectomy was also performed, according to the intraoperative findings and frozen-section examination results. Final histopathology showed 99 (88.4%) solitary parathyroid (PT) adenomas and 3 (2.7%) PT carcinomas, while 10 (8.9%) patients had a multiglandular disease. The sensitivity and positive predictive value (PPV) were (group A vs group B) 79.8% vs 70.8% (P=0.25) and 95.7% vs 94.4% (P=0.58) for US, and 83.3% vs 87.0% (P=0.47) and 95.9% vs 90.9% (P=0.32) for SS respectively. Better but similar (P=not significant) results were obtained in patients with solitary PT tumours: 81.5% vs 77.8% (US) and 85.0 vs 94.1% (SS) sensitivity; 97.1% vs 93.3% (US) and 95.8% vs 88.9% (SS) PPV. Overall, the combination of US and SS was 92.9% sensitive (group A=93.1%, group B=92.0%; P=0.55), and the PPV reached 100% in each group. In conclusion, in patients with primary hyperparathyroidism the results of both US and SS are independent of coexistent thyroid disease, especially in patients with solitary PT tumours.     

The role of intravascular ultrasound in the diagnosis and treatment of patients with coronary artery disease

Approximately 95% of the coronary vasculature is atherosclerotic before lesions are visible by coronary angiography. Intravascular ultrasound assesses the burden of coronary atherosclerosis, as well as clarifying the anatomical and physiological characteristics of ambiguous lesions.     

Synthesis and PGE<Subscript>2</Subscript> Inhibitory Activity of 5,7-Dihydroxyflavones and Their<Emphasis Type="Italic">O</Emphasis>-Methylated Flavone Analogs

5,7-Dihydroxyflavones and their O-methylated flavone analogs were prepared and evaluated their anti-inflammatory activity to decipher the structure-activity relationships. Most of the analogs were achieved from 2,4,6-trihydroxyacetophenone in 4 steps. 5,7-Dihydroxy-4'-methoxyflavone (4c) and 7-hydroxy-4',5-dimethoxyflavone (6c) were prepared following a different synthetic pathway. Among the synthetic flavones tested, 5-hydroxy-7-methoxyflavone analogs (3a-3e) showed moderate inhibitory activities of PGE2 production from LPS-induced RAW 264.7 cells.     

LABAZ1: A metastatic tumor model for renal cell carcinoma expressing the carbonic anhydrase type 9 tumor antigen

A metastatic renal cell carcinoma (RCC) tumor model xenograft that expresses the targetable, membrane-bound tumor-associated antigen carbonic anhydrase type 9 (CA IX) is described. The xenograft, established from a high-grade type-2 chromophil RCC (cRCC), has been serially transplanted in immune compromised mice, in which it grows orthotopically under the renal capsule, doubling its size every 9 weeks and sending metastases to the lung and liver at approximately 20 weeks. Tumors were capable of being imaged using a micro-PET (micro-positron emission tomograph) with an 18-fluorodeoxyglucose (18-FDG) tracer. Subsequent xenograft generations have conserved immunohistochemical and ultrastructural properties typical for malignant renal epithelium-derived neoplasia (vimentin+, CK-19+, CA IX+ with hypoxia-inducible factor (HIF)-1 alpha constitutive expression) and have demonstrated extensive proliferation, lack of apoptosis, severe genetic alterations, and molecular expression alterations; transforming growth factor beta 1 (TGF-beta 1), hepatocyte growth factor (HGF), proto-oncogene (c-met), matrix metalloproteinase (MMP)-1, and vascular endothelial growth factor (VEGF) C and D were overexpressed, whereas human epidermal growth factor receptor (HER)-2, MMP-2 and MMP-9, VEGF-R3, p53, and p27 were severely down-regulated, suggesting a proangiogenic environment, local invasiveness, and facilitated lymphatic metastasis. Altogether, LABAZ1 provides a relevant and flexible model to study the biology of cRCC, the role of CA IX in RCC tumorigenesis, progression, and metastasis, and a platform for testing new targeted therapeutic strategies.     

Evidence-based radiology: requirements for electronic access

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the electronic requirements for supporting evidence-based radiology in today's medical environment. MATERIALS AND METHODS: A software engineering technique, use case modeling, was performed for several clinical settings to determine the use of imaging and its role in evidence-based practice, with particular attention to issues relating to data access and the usage of clinical information. From this basic understanding, the analysis was extended to encompass evidence-based radiologic research and teaching. RESULTS: The analysis showed that a system supporting evidence-based radiology must (a) provide a single point of access to multiple clinical data sources so that patient data can be readily used and incorporated into comprehensive radiologic consults and (b) provide quick access to external evidence in the way of similar patient cases and published medical literature, thus supporting evidence-based practice. CONCLUSION: Information infrastructures that aim to support evidence-based radiology not only must address issues related to the integration of clinical data from heterogeneous databases, but must facilitate access and filtering of patient data in order to improve radiologic consultation.     

Pharmacokinetics of paclitaxel administered by hyperthermic retrograde isolated lung perfusion techniques

OBJECTIVE: Although paclitaxel is widely used as a systemic agent for the treatment of solid tumors, limited information is available concerning administration of this taxane by regional techniques. The present study was undertaken to evaluate the pharmacokinetics and acute toxicity of paclitaxel administered by hyperthermic retrograde isolated lung perfusion techniques to ascertain its potential for the regional therapy of unresectable pulmonary neoplasms. METHODS: Adult sheep underwent 90 minutes of retrograde isolated lung perfusion with escalating doses of paclitaxel and moderate hyperthermia using a protein-free, oxygenated extracorporeal circuit and a steady perfusion pressure of 14 to 16 mm Hg. An additional animal received paclitaxel by means of 1-hour central venous infusion. Paclitaxel concentrations in lung tissues, perfusates, and systemic circulation were determined by high-performance liquid chromotography techniques. Cytotoxicity of paclitaxel in cancer cells and in normal human bronchial epithelial cells was evaluated in vitro using 4, 5-dimethylthiazo-2-yl-25-dipagnyl tetrazolium bromide assays. Lung tissues were examined by hematoxylin-and-eosin techniques. RESULTS: Paclitaxel concentrations (maximum concentration and area under the plasma concentration time curve) in perfused tissues increased with escalating perfusate doses. Uptake of drug into lung parenchyma appeared saturable at high paclitaxel exposure; a substantial pharmacokinetic advantage was observed. Paclitaxel concentrations in systemic circulation were undetectable or exceedingly low after perfusion. Histopathologic examination of lung tissues harvested 3 hours after completion of isolated lung perfusion revealed no immediate toxicity, even at a paclitaxel exposure 20-fold higher than that achievable after 1 hour of intravenous administration at the maximum tolerable dose in human subjects. Moderate hyperthermia enhanced paclitaxel-mediated cytotoxicity 5- to 100-fold in cultured cancer lines. No paclitaxel toxicity was observed in cultured normal human bronchial epithelial cells after exposure to paclitaxel under normothermic or hyperthermic conditions. CONCLUSIONS: These data support further evaluation of paclitaxel administered by hyperthermic retrograde isolated lung perfusion techniques for the treatment of unresectable malignant pulmonary tumors.     

Positive predictive value of 99mTc sestamibi scintimammography in patients with non-palpable,mammographically detected,suspicious, breast lesions

The purpose of this study was to analyse whether the use of Tc sestamibi scintimammography improves the positive predictive value of X-ray mammography. A series of 73 women (median age 51 years, range 35-79 years) with non-palpable, mammographically suspicious, breast lesions was reviewed. There were 41 (56.2%) pre-menopausal, and 32 (43.8%) post-menopausal women. All patients underwent sestamibi scintimammography prior to open breast biopsy. Definitive histology showed breast cancer (pT1a=1 (1.9%), pT1b=47 (90.4%), pT1c=4 (7.7%)) in 52 (71.2%) patients, and benign breast lesions in 21 (28.8%). Patients with cancer were significantly older (P <0.01), while the greatest dimension (size) of the excised lesion did not differ (8.47+/-1.51 vs 8.30+/-1.53 mm; P =0.66) between the two groups. Overall, the positive predictive values of mammography and sestamibi scintimammography were 71.2% and 95.7%, respectively (P =0.004). Patients with false positive mammography were significantly younger than those in whom cancer was diagnosed correctly (45.35+/-7.56 vs 53.96+/-10.60 years; P =0.001), while age did not affect the sensitivity of sestamibi scintimammography, which reached 100% in patients with breast lesions > or =8 mm in size. In this subgroup the positive predictive value of mammography, sestamibi scintimammography, and mammography+sestamibi scintimammography together were 63.4%, 95.1% (P =0.001), and 97.6%, respectively, and the majority of the patients with benign lesions (13 of 15 (86.7%)) could have avoided biopsy. It is concluded that the use of Tc sestamibi scintimammography in conjunction with mammography may potentially reduce unnecessary surgical procedures, and should be performed in all patients with mammographically suspicious breast lesions of 8 mm or greater in size.