命门探源

关于命门学说的发生学原理,目前主要有两种观点。一种观点认为,《难经》《内经》命门说深受哲学界水火之争的影响,另一种观点认为《难经》命门学说起源于“水生万物说”。两种观点均有不尽完善之处。考明代孙一奎、赵献可、张景岳对命门学说的阐述,知医家的命门学说脱胎于道家的“玄牝学说”,而道家的“玄牝学说”则肇始于春秋《老子》。命门学说是道家养生理论与医学实践逐步结合的产物。     

Clinical relevance of the distribution of the lesions in 500 consecutive breast cancer cases documented in large-format histologic sections

BACKGROUND: Breast carcinoma is a heterogeneous group of diseases deviating from each other not only in their clinical manifestations and outcome but also in their histologic appearance. The submacroscopic morphology of breast carcinomas, the distribution of the lesions, and the extent of the disease are seldom studied. Even more infrequently are these parameters included in surgical pathology reports. Conversely, the routine use of large-format histologic sections in workup of operated breast specimens provides better insight into the significance of these parameters. The aim of the study was to identify breast carcinoma growth patterns indicating increased metastatic potential of the tumor and a need for more aggressive therapy. METHODS: In all, 500 consecutive breast cancer cases, all of which were documented on large-format histologic sections, were retrospectively analyzed. The distribution of both in situ and invasive components of the tumors (unifocal/multifocal/diffuse) was defined, determined, and compared with the type of surgical intervention performed and the frequency of ipsilateral lymph node metastasis as endpoints. The extent of the disease, the size of the tumor, the presence or absence of lymphovascular invasion (LVI), and the proportion of invasive lobular carcinomas in the categories with different distributions were also analyzed. RESULTS: Only 34% of the analyzed cases could be categorized as unifocal. This kind of tumor distribution was associated with lymph node metastasis in 28% of the cases, with LVI in 18%, with breast-conserving surgery in 67%, and with a proportion of 4% invasive lobular carcinomas. Tumors with a unifocal invasive component upgraded to multifocal or diffuse because of the distribution of the associated in situ component had similar characteristics. With their larger extent, tumors with a diffuse in situ component required mastectomy in 43% of cases. Multifocal distribution of the invasive component in the tumors was associated with higher frequency of LVI (42%) and lymph node metastases (48%), with a substantially lower number of cases undergoing breast-conserving surgery (33%) and with a higher proportion of lobular carcinomas (25%). If the multifocal invasive foci were associated with a diffuse in situ component, the proportion of invasive lobular carcinomas was only 5%. The extent of the lesions (defined as the area of breast tissue involved by in situ, invasive, and/or intravascular tumor foci) was >or=2 cm in >90% of multifocal cases and >or=4 cm in >70%. Diffusely growing invasive carcinomas were rare (only 20 cases), but were associated with lymph node metastasis in 60% of cases and resulted in mastectomy in 85% of the cases. Approximately two-thirds (65%) of these tumors belonged to invasive lobular carcinomas. The extent of diffusely growing invasive carcinomas was >or=4 cm in 75% of the cases. Although LVI was detected in only 10% of tumors with a diffusely growing invasive component, such tumors were found to have lymph node metastasis significantly more often (odds ratio of 2.33) and required mastectomy much more frequently (odds ratio of 2.58) compared with purely unifocal breast carcinomas. CONCLUSIONS: These results indicate that the distribution of invasive and in situ tumor structures in breast carcinomas as defined in the current study, together with the extent of disease, are important morphologic parameters which determine the required surgical intervention and are related to biologic factors such as metastatic capacity. The method of large-section histology allows the examiner to properly document and demonstrate these important parameters, thus facilitating understanding of their clinical relevance.     

Solubility Prediction of Satranidazole in Propylene Glycol-Water Mixtures Using Extended Hildebrand Solubility Approach

Extended Hildebrand solubility approach is used to estimate the solubility of satranidazole in binary solvent systems. The solubility of satranidazole in various propylene glycol-water mixtures was analyzed in terms of solute-solvent interactions using a modified version of Hildebrand-Scatchard treatment for regular solutions. The solubility equation employs term interaction energy (W) to replace the geometric mean (δ₁δ₂), where δ₁ and δ₂ are the cohesive energy densities for the solvent and solute, respectively. The new equation provides an accurate prediction of solubility once the interaction energy, W, is obtained. In this case, the energy term is regressed against a polynomial in δ₁ of the binary mixture. A quartic expression of W in terms of solvent solubility parameter was found for predicting the solubility of satranidazole in propylene glycol-water mixtures. The expression yields an error in mole fraction solubility of ~3.74%, a value approximating that of the experimentally determined solubility. The method has potential usefulness in preformulation and formulation studies during which solubility prediction is important for drug design.     

A closure scheme for chemical master equations

Probability reigns in biology, with random molecular events dictating the fate of individual organisms, and propelling populations of species through evolution. In principle, the master probability equation provides the most complete model of probabilistic behavior in biomolecular networks. In practice, master equations describing complex reaction networks have remained unsolved for over 70 years. This practical challenge is a reason why master equations, for all their potential, have not inspired biological discovery. Herein, we present a closure scheme that solves the master probability equation of networks of chemical or biochemical reactions. We cast the master equation in terms of ordinary differential equations that describe the time evolution of probability distribution moments. We postulate that a finite number of moments capture all of the necessary information, and compute the probability distribution and higher-order moments by maximizing the information entropy of the system. An accurate order closure is selected, and the dynamic evolution of molecular populations is simulated. Comparison with kinetic Monte Carlo simulations, which merely sample the probability distribution, demonstrates this closure scheme is accurate for several small reaction networks. The importance of this result notwithstanding, a most striking finding is that the steady state of stochastic reaction networks can now be readily computed in a single-step calculation, without the need to simulate the evolution of the probability distribution in time.     

Sifting,sorting and saturating data in a grounded theory study of information use by practice nurses: A worked example

The terminology used to analyse data in a grounded theory study can be confusing. Different grounded theorists use a variety of terms which all have similar meanings. In the following study, we use terms adopted by Charmaz including: initial, focused and axial coding. Initial codes are used to analyse data with an emphasis on identifying gerunds, a verb acting as a noun. If initial codes are relevant to the developing theory, they are grouped with similar codes into categories. Categories become saturated when there are no new codes identified in the data. Axial codes are used to link categories together into a grounded theory process. Memo writing accompanies this data sifting and sorting. The following article explains how one initial code became a category providing a worked example of the grounded theory method of constant comparative analysis. The interplay between coding and categorization is facilitated by the constant comparative method.     

King达标理论干预带教改善妇产科实习男护生的自我和谐状况

目的分析影响妇产科实习男护生自我和谐状况的因素,并探讨King达标理论干预带教对其自我和谐状况的影响。方法方便性抽样选择五年制滨州医学院2007、2008级护理专业本科参加妇产科临床实习的122名男护生,随机分为对照组和观察组。观察组采用King达标理论对妇产科实习带教实施干预,对照组采用传统实习带教方法。采用《自我和谐量表》(self consistency and congruence scale,SCCS)分别对两组学生进行测评,观察其自我和谐状况。结果男护生自我和谐状况受多种因素影响,其中独生子女对自我与经验的不和谐性影响较大,毕业后职业取向对自我灵活性影响较大,学生干部对自我刻板性影响较大,差异均有统计学意义(P<0.05)。观察组男护生自我和谐程度优于对照组,差异有统计学意义(P<0.05)。结论男护生自我和谐状况受多种因素影响,King达标理论用于男护生妇产科实习带教,有助于提高实习男护生的总体自我和谐度。     

The Role of Television Access in the Viewing Time of US Adolescents

We identify the adolescent and family factors that shape the time adolescents spend viewing television. Adolescent traits, family/household characteristics, television access, and TV viewing time were assessed by self-report using a web-based survey conducted with a sample of 457 14- to 16-year-old adolescents in a Northeastern US city. Bivariate analyses indicated that the number of televisions in the home, having a bedroom TV, and subscribing to premium cable/satellite channels were each positively and significantly associated with television viewing time. Regression results show that having greater access to TV significantly increased viewing independent of adolescent and family variables. In addition, the influence of different forms of access on adolescent time varied by respondent race. Having a television set in the bedroom was the strongest predictor of TV time for White adolescents, and having more television sets in the home was the strongest predictor of TV time for Black adolescents. The pattern of findings suggests that interventions should encourage parents to make their adolescents' bedrooms television free and to reduce the number of television sets in the home. Campaigns designed to reduce TV viewing may be most effective if they are tailored for distinct audiences.     

My health and theirs: clients constructing meanings for a health service programme for unemployed people

Health care research has been more interested in identifying reasons why people do not participate in health interventions than in trying to understand the reasons why they do. This study examined how unemployed people position themselves with regard to a new health service which was set up as part of an institutional strategy for delivering and enabling their access to health care. Positioning theory was used as a methodological framework to analyse participants’ responses to the novel health service. The focus was on two main issues: the way clients’ positions are established through discourse, and the range of factors that come into play in determining those positions. The analysis revealed six positions unemployed people use when encountering the studied service: the docile citizen, the rebel, the socially responsible citizen, the distinctive individual, the independent actor and the calculating client. These positions and associated discourses display the different sets of rights and duties of the client and simultaneously define the positions of the service. While illustrating how a health service engaged with the ideology of equality is integrated into the value framework of the clients, the findings contribute to the ongoing debate on need of particular health services for unemployed people.     

An atomistic picture of the regeneration process in dye sensitized solar cells

A highly efficient mechanism for the regeneration of the cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)-ruthenium(II) sensitizing dye (N3) by I^- in acetonitrile has been identified by using molecular dynamics simulation based on density functional theory. Barrier–free complex formation of the oxidized dye with both I^- and , and facile dissociation of and from the reduced dye are key steps in this process. In situ vibrational spectroscopy confirms the reversible binding of I₂ to the thiocyanate group. Additionally, simulations of the electrolyte near the interface suggest that acetonitrile is able to cover the (101) surface of anatase with a passivating layer that inhibits direct contact of the redox mediator with the oxide, and that the solvent structure specifically enhances the concentration of I^- at a distance which further favors rapid dye regeneration.