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51.
Determination has been made of the sensitivity of LR115 type 2-track detectors (in units of m) to 222Rn, measured in the presence of 220Rn. Measurements have been made by means of a widely used diffusion chamber while Monte Carlo simulations have also been conducted. The experimentally derived sensitivities for 222Rn and 220Rn were found to be 0.470±0.022 and 0.486±0.042 m, respectively. For Monte Carlo simulations, the sensitivities to 222Rn gas were found to range from 0.618×10–2 m (assuming that all 218Po progeny decay before deposition onto the internal walls of the diffusion chamber) to 0.405×10–2 m (assuming that all 218Po progeny are deposited on the internal walls of the same containment vessel before decaying). The sensitivity to 220Rn gas of 0.465×10–2 m found from Monte Carlo simulations agrees to within uncertainty with experimental findings. The experimentally derived sensitivity value for 222Rn indicates that 30% of the 218Po progeny decay before deposition onto the internal walls of the diffusion chamber.  相似文献   
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53.
锌酞菁脂质体光动力作用引起小鼠肿瘤的细胞程序性死亡   总被引:3,自引:1,他引:3  
电镜观察了锌酞菁脂质体光动力作用引起小鼠MS-2纤维肉瘤的形态学变化。发现其作用很强,并对肿瘤细胞有明显的直接影响。肿瘤细胞的结构表现出明显的程序性细胞死亡(apoptosis,programmedceldeath)的特点:胞核染色质凝聚边集、核固缩、核破裂、染色质凝块流失、胞质内吞噬现象、胞膜表面肿胀粗钝的胞突形成、细胞碎裂等。加深了对锌酞菁脂质体光敏作用机理的认识,但其详细的发生机制和调节途径有待阐明。  相似文献   
54.
C H Cho  C W Ogle  S H Wong  M W Koo 《Digestion》1985,32(4):288-295
The effect of zinc sulphate on stomach ulceration produced by ethanol and indomethacin was examined in rats. Oral or intraperitoneal pretreatment with zinc sulphate (20 mg/kg, expressed as zinc ion) strongly prevented ethanol-, but not indomethacin-induced gastric glandular ulceration. Indomethacin given beforehand did not influence the protective action of zinc sulphate against ethanol-evoked lesions. Ethanol decreased histamine levels, whereas indomethacin reduced the prostaglandin E2 (PGE2) content in the gastric glandular mucosa. The alcohol also elevated the histamine content in gastric secretion. Zinc sulphate reversed the ethanol-induced changes in histamine levels in both mucosa and secretion, but did not modify PGE2 reduction by indomethacin. Zinc sulphate also antagonised protein leakage from the stomach following ethanol administration. It is concluded that gastric ulceration by the currently employed doses of ethanol and indomethacin is caused by different mechanisms. Zinc sulphate prevents histamine-mediated lesions produced by the alcohol, but not ulceration due to PGE2 depletion by indomethacin.  相似文献   
55.

Background

Various techniques for endoscopic thyroidectomy have been introduced in the past decade, and the cosmetic superiority of these techniques has been universally acknowledged. We developed the endoscopic thyroidectomy via bilateral axillo-breast approach (BABA) and have performed more than 500 operations. The aims of this study are to analyze the surgical outcomes and to evaluate the effectiveness and safety of BABA endoscopic thyroidectomy.

Patients and methods

Between February 2004 and March 2008, 512 patients with thyroid diseases underwent BABA endoscopic thyroidectomy. The criteria analyzed were clinicopathologic characteristics, types of operation, operation time, tumor–node–metastasis (TNM) stage on the basis of the 7th edition of the American Joint Committee on Cancer (AJCC), results after radioactive ablation therapy, and recurrence of disease in these patients.

Results

Of 512 patients, 397 had a malignant tumor and 115 had benign thyroid disease. Eight patients were diagnosed with Graves’ disease, and nine patients underwent completion thyroidectomy. Three cases were subjected to open thyroidectomy due to uncontrolled bleeding. Mean operation time was 151.2?±?38.1?min for total and near-total thyroidectomy, and 141.7?±?50.1?min for subtotal thyroidectomy and lobectomy. Regarding postoperative complications, transient hypocalcemia occurred in 31.1% of patients and permanent hypoparathyroidism occurred in 4.2% of patients. Transient hoarseness occurred in 20.3% of patients, and permanent vocal cord palsy occurred in 1.7%. Mean hospital stay after operation was 3.34?±?0.8?days (range 3–7?days), and mean follow-up period was 57.1?±?17.6?months (range 38.5–71.7?months). There were eight cases of recurrent thyroid carcinoma, and no mortality has occurred up to the present time.

Conclusions

Endoscopic thyroidectomy via bilateral axillo-breast approach is a safe and effective method that gives good surgical completeness, a low rate of postoperative complications and recurrence, and an excellent cosmetic result. Therefore, this method is a good choice for patients with surgical thyroid diseases.  相似文献   
56.
57.
Perforation of the ureter is a rare condition that causes a series of problems including retroperitoneal urinoma, urosepsis, abscess formation, infection, and subsequent renal impairment. There are causative factors that induce ureteric rupture, including malignancy, urinary calculi, idiopathic retroperitoneal fibrosis, recent iatrogenic manipulation, external trauma, degenerative kidney conditions, urography with external compression, and spontaneous causes. We report a rare case of ureteric rupture caused by urinary retention. The patient was treated with temporary percutaneous drainage and antibiotics. The present case illustrates that urinary retention can induce not only bladder rupture, but also ureteric rupture. It is thus of paramount importance to effectively manage patients with voiding problems.  相似文献   
58.
BACKGROUND: Earlier studies have provided evidence for increased production of reactive oxygen species (ROS) and altered nitric oxide (NO) metabolism in diabetes. This study was intended to explore the effect of type I diabetes and its treatment with insulin alone or insulin plus antioxidant-fortified diet on expression of NOS isoforms and ROS interactions with lipids, glucose and NO. METHODS: Rats with streptozotocin-induced diabetes were divided into once-daily insulin (ultralente)-treated, insulin plus antioxidant (vitamin E and vitamin C)-treated and untreated groups. After four weeks, plasma malondialdehyde (MDA) and tissue endothelial (eNOS), neuronal (nNOS) NO synthases, carboxymethyllysine (CML) and nitrotyrosine were determined. RESULTS: The untreated diabetic animals exhibited severe hyperglycemia, elevated blood pressure, increased plasma MDA, high tissue CML and reduced tissue nitrotyrosine denoting enhanced lipid, glucose and protein oxidation but reduced NO oxidation by ROS. This was coupled with significant reduction of eNOS and nNOS expression in renal cortex and eNOS in the left ventricle. Insulin therapy partially lowered blood pressure, tissue CML, plasma glucose and MDA, but significantly raised eNOS expression and nitrotyrosine abundance to supranormal levels. Combined insulin and antioxidant therapies resulted in normalization of blood pressure, plasma MDA, tissue CML and nitrotyrosine without affecting glucose level or NOS expression. CONCLUSION: Oxidative stress in untreated diabetes is associated with down-regulation of NOS isoforms and increased ROS-mediated oxidation of lipid and glucose, but not NO. Amelioration of hyperglycemia with once-daily insulin administration alone results in up-regulation of NOS isoforms, reduction of lipid and glucose oxidation and increased NO oxidation. However, insulin plus antioxidant supplementation can normalize all three parameters.  相似文献   
59.
We report a laparoscopic Nissen fundoplication for gastroesophageal reflux disease in a patient with situs inversus totalis. The 65-year-old man was previously diagnosed with situs inversus totalis and presented with chronic gastroesophageal reflux disease inadequately controlled by medications. The laparoscopic procedure was performed with 5 ports placed in a mirror-image configuration and with the patient in the lithotomy position. Few technical difficulties were encountered during the operation. The position of the primary surgeon, working between the lower limbs of the patient, was considered critical to the success of this case. In situs inversus totalis, this position provides the least visual disorientation from the reversed abdominal organs. We recommend this position for all upper abdominal laparoscopic procedures in patients with situs inversus totalis, including laparoscopic cholecystectomy.  相似文献   
60.

Background

Malseating of ceramic liner appeared as a matter of concern in multibearing metal, although multibearing cup can be coupled with hard liners as well as polyethylene liner. In this metal shell, the inner taper angle should be 10° for the modularity, while standard metal shells for ceramic liner have an inner taper angle of 18°. However, there has been no study in the effect of taper angle to the risk of malseating. We evaluated whether the taper angle of metal shell might affect the malseating of ceramic liner, and dissociation force of ceramic liner from metal shell.

Methods

Three surgeons manually inserted ceramic liners into two designs of metal shell with different tapers angles (10° and 18°). We compared malseating rates of ceramic liners and push-out strengths, which means dissociation force of the ceramic liner from the metal shell, between these two metal shell designs.

Results

The malseating rates in 10° metal shell were higher than those in 18° metal shell (23.3% vs 0%, P < .05). The mean dissociation force (1148.8 ± 46.7 N) in 10° taper cup was higher than that (389.7 ± 108.3 N) in 18° taper cup (P < .01).

Conclusion

Our results suggest that surgeon should be cautious about malseating of ceramic liner when using multi-bearing metal shell with inner taper angle of 10°.

Clinical relevance

When surgeon use multi-bearing metal shell with inner taper angle of 10°, our results suggest that surgeon should be cautious about malseating of ceramic liner.  相似文献   
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