生理信号检测中的同步工频陷波器

市电50Hz干扰一直是生理信号检测过程中最难以克服的问题之一。本文叙述了利用同步滤波器技术克服50Hz干扰的方法。同步滤波器可以自动跟踪市电频率的变化且具有极高Q值和理想的梳状滤波特性,而元件的灵敏度却很低,因而很容易获得40dB以上的陷波效果,可以从根本上克服50Hz干扰而几乎对有用信号毫无影响。     

The use of 3D surface fitting for robust polyp detection and classification in CT colonography

In this paper we describe the development of a computationally efficient computer-aided detection (CAD) algorithm based on the evaluation of the surface morphology that is employed for the detection of colonic polyps in computed tomography (CT) colonography. Initial polyp candidate voxels were detected using the surface normal intersection values. These candidate voxels were clustered using the normal direction, convexity test, region growing and Gaussian distribution. The local colonic surface was classified as polyp or fold using a feature normalized nearest neighborhood classifier. The main merit of this paper is the methodology applied to select the robust features derived from the colon surface that have a high discriminative power for polyp/fold classification. The devised polyp detection scheme entails a low computational overhead (typically takes 2.20 min per dataset) and shows 100% sensitivity for phantom polyps greater than 5 mm. It also shows 100% sensitivity for real polyps larger than 10 mm and 91.67% sensitivity for polyps between 5 to 10 mm with an average of 4.5 false positives per dataset. The experimental data indicates that the proposed CAD polyp detection scheme outperforms other techniques that identify the polyps using features that sample the colon surface curvature especially when applied to low-dose datasets.     

两种气体灭菌剂灭菌效果及评价方法

目的：探讨医院气体灭菌效果和检测方法，以保证灭菌质量。方法：对本院常用的两种低温气体灭菌剂环氧乙烷和甲醛，采用枯草杆菌黑色变种芽胞生物指示管分别选择不同时间和不同方法进行灭菌效能检测。结果：环氧乙烷全自动灭菌(全过程16h)和甲醛催化法灭菌≥2h均可达到灭菌要求，而甲醛催化法灭菌时间少于2h和甲醛自然挥发法灭菌均达不到灭菌水平。结论：环氧乙烷生物指示管可应用于甲醛气体的灭菌检测；环氧乙烷全自动灭菌和甲醛催化法灭菌可用于不耐热、不耐湿的手术器械灭菌。     

Differences in the hypothermic response to ethanol in rats selectively bred for oral ethanol preference and nonpreference

The duration of retention of tolerance to ethanol was tested in the alcohol-preferring (P) and alcohol-nonpreferring (NP) rats lines, using ethanol-induced hypothermia as a measure of tolerance. Rats received two injections of ethanol (3.5 g/kg) body wt, IP) and the time between the injections was 1, 2, or 3 days. When one day separated the two injections, tolerance to the hypothermic effect of a second “test” injection was found in both lines. When 2 or 3 days separated the two injections, the P line showed a loss of tolerance and the NP line showed sensitization to ethanol. Sensitization in the NP line grew stronger when the interval between injections was increased from 2 to 3 days. The duration of retention of tolerance to ethanol-induced hypothermia in the P line was shorter than has previously been reported for motor impairment in this line. It appears that the duration of tolerance retention in the P line depends on the test used to measure tolerance. Sensitization to ethanol in the NP line may be associated with low oral ethanol intake. This research was supported, in part, by grants AA08312, AA03243, and AA07611 from the PHS     

In vivo fluorescence spectroscopy and imaging of human skin tumours

The feasibility of using in vivo autofluorescence for the diagnosis of skin cancer was evaluated. In vivo fluorescence measurements were performed on healthy human volunteers, and patients with different types of benign and malignant skin tumours. Fluorescence spectra as well as fluorescence images were acquired. The excitation-emission matrix of normal skin (n=3) showed a broad peak at the shortest excitation wavelength (365 nm) and at 440 nm fluorescence wavelength, smoothly decreasing towards longer excitation and fluorescence wavelengths. Non-melanoma skin tumours (n=31) and control skin excited with 375 nm showed a broad fluorescence band from 400 to 700 nm, peaking around 436 nm. No significant differences in measurements between tumours and the corresponding control sites were found. A large spatial variation in the fluorescence intensity was observed both in the tumours and in the control sites. Standard deviations found ranged from 0.15 to 1.5 times the mean fluorescence. Fluorescence images, excited with 375 nm and taken with an image intensified CCD camera, on eight malignant melanomas and eight benign pigmented lesions did not indicate any fluorescence intensity distribution specific to the malignancy of the lesion. Neither the shape of the fluorescence spectra, nor the spatial distribution of the fluorescence intensity showed any signature specific to the histopathological nature of the lesions investigated. Optical diagnostics of skin tumours using the autofluorescence does not seem to be feasible at the present time.     

Comparison of redox and D29 phage methods for detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis

Rapid, accurate and inexpensive methods are essential to detect drug-resistant Mycobacterium tuberculosis and allow timely application of effective treatment and precautions to prevent transmission. The proportion method, the MTT and Alamar Blue redox methods, and the D29 mycobacteriophage assay, were compared for their ability to detect resistance to isoniazid and rifampicin. When tested against a panel of known M. tuberculosis strains, the redox methods and the D29 assay showed good sensitivity and specificity compared to the proportion method, suggesting that they could be useful alternatives for identifying multidrug resistance in M. tuberculosis.     

短期用药对幽门螺杆菌检测结果的影响

目的：研究短期不规则用药对幽门螺杆菌(Hp)检测结果的影响。方法：136名慢性胃炎及消化性溃疡的住院患，根据病史分为服药组即Hp检查前一周内接受过铅剂、抑酸剂治疗的患，共四例。对照组即Hp检查前未接受过药物治疗的患考，共37例。Hp检查方法包括①血清学方法；②快速尿素酶试验(RUT)；③组织学方法；④13c—尿素呼气试验(13C—UBT)。结果：服药组RUT，组织学，13C—UBT方法Hp检出率分别为9．0％，21．2％，27．3％，均显低于对照组相应Hp检出率37．8％、40．5％、48．6％(P＜0．01，P＜0．05，P＜0．05)。两组血清学方法Hp IgG、IgM阳性率各为48．5％，51．5％和54．1％，54．1％(P＞0．05)。单独服用质子泵抑制剂组RUT，组织学方法Hp检出率4．0％，16．0％显低于对照组相应方法Hp检出率(P＜0．01，P＜0．05)。单独服用枸橼酸铋钾、H2受体拮抗剂患中各方法Hp检出率与对照组检出率无显性差异(P＞0．05)。单独服用枸橼酸铋钾、H2受体拮抗剂、质子泵抑制剂三组Hp感染率14．3％、15．0％、16．0％均显低于对照组Hp感染率46．0％(P＜0．05)。结论：Hp检查前短期使用铋剂、抑酸剂可导致Hp检出率下降，短期使用质子泵抑制剂可显降低RUT、组织学方法Hp检出率；各方法中快速尿素酶试验检出率最低。血清学方法检测Hp抗体不受药物影响。     

Breast cancer surveillance — a cost-effective strategy

Summary The effectiveness of a surveillance program for breast cancer recurrence in extending survival is predicated on two assumptions: 1) most recurrences are detected at an early stage at surveillance visits; and 2) the early treatment of recurrence offers a better chance of cure or longer survival. However, the data suggest that neither of these two assumptions is correct, and that postoperative follow-up of patients with breast cancer is expensive and does not significantly extend survival.This minisymposium was presented December 8, 1992, at the annual San Antonio Breast Cancer Symposium, and was sponsored by educational grants from Amgen and from Bristol-Myers Oncology Division.     

High-Performance Liquid Chromatographic (HPLC) Assay Using Fluorescence Detection for the Simultaneous Determination of Gallopamil and Norgallopamil in Human Plasma

Gallopamil is a calcium-channel antagonist with reported activity in experimental animals three to five times higher than that of verapamil. An automated high-performance liquid chromatographic (HPLC) method with fluorescence detection is described for the simultaneous determination of gallopamil and its metabolite norgallopamil in plasma. Gallopamil was well resolved from norgallopamil and other metabolites, allowing simultaneous quantitation of both drugs. The detection limit for both gallopamil and norgallopamil was 0.9 ng/ml. This method has been successfully used for the determination of gallopamil and norgallopamil following the administration of 25-, 37.5-, and 50-mg oral doses of drug.