Multifactor,Sequentially Releasing Scaffolds for Tissue Engineering:Fabrication Using Solvent/Nonsolvent Sintering Technology

Biodegradable constructs, providing both mechanical support to growing tissues and timed release of biological agents, are highly desired in tissue engineering. This study aimed to develop a platform technology that responds to these challenges. Accordingly, we report herein on model systems in which microspheres of poly(suberic anhydride), containing all-trans retinoic acid (atRA), and poly(d,l -lactic acid-co-glycolic acid), containing bovine serum albumin (BSA), were co-sintered at room temperature, using a solvent/nonsolvent mixture. These scaffolds release about 60% of atRA and negligible amounts of BSA within the first five days, followed by slower and steady release of BSA. They have pores of 150–500 μm and a compressive modulus of 200 kPa. Myoblasts and fibroblasts were seeded on the loaded scaffolds and both showed enhanced proliferation rates. Based on sound thermodynamic principles of polymer science, this technology demonstrates an as yet unachieved degree of versatility. It allows for the tailoring of “intelligent” scaffolds that preserve the integrity of the incorporated agents and of advanced modalities to release various drugs in a scheduled manner.     

解舒率的分布及其特征数

本文利用一粒茧的中途落绪数服从卜里耶·埃肯别尔根(Polya Eggenbergen)分布的结论,直接从解舒率的定义出发导出了解舒率的理论分布,求出其期望和方差的表达式,并证明了当n→∞时解舒率渐近地服从正态分布N(1/(1 λ),λ(1 ρ)/(n(1 λ)~4)))。最后对理论结果进行了随机模拟和检验,并讨论了分布参数的变化对解舒率的方差的影响,还讨论了应用中的一些问题。     

超高频单片集成锁相环SE564及其应用

详细介绍了锁相鉴频电路的工作原理，并以超高频单片集成锁相环SE564为例，介绍了其结构、组成与应用，具有较强的实用性。     

Practical reliable Bayesian recognition of 2D and 3D objects usingimplicit polynomials and algebraic invariants

We treat the use of more complex higher degree polynomial curves and surfaces of degree higher than 2, which have many desirable properties for object recognition and position estimation, and attack the instability problem arising in their use with partial and noisy data. The scenario discussed in this paper is one where we have a set of objects that are modeled as implicit polynomial functions, or a set of representations of classes of objects with each object in a class modeled as an implicit polynomial function, stored in the database. Then, given partial data from one of the objects, we want to recognize the object (or the object class) or collect more data in order to get better parameter estimates for more reliable recognition. Two problems arising in this scenario are discussed: 1) the problem of recognizing these polynomials by comparing them in terms of their coefficients; and 2) the problem of where to collect data so as to improve the parameter estimates as quickly as possible. We use an asymptotic Bayesian approximation for solving the two problems. The intrinsic dimensionality of polynomials and the use of the Mahalanobis distance are discussed     

Myeloma ascites--a favorable outcome with cyclophosphamide therapy

PURPOSE: To find out the role of Catalin in the prevention of posterior capsular opacification (PCO), we undertook this experimental study in rabbits. METHODS: Twenty rabbits (10 for the Catalin group and 10 for the placebo group) were operated on for extracapsular clear lens extraction in an aseptic environment. In all cases, capsulorrhexis of 8 mm diameter was carried out. Both the test drug and placebo were given at a dose of 4 times/day from the first postoperative day for 8 weeks. Common drugs in both groups were topical corticosteroid, antibiotic and cycloplegic drops. Periodic slitlamp examinations and photographic documentations were carried out to find any evidence of aftercataract. At the end ot 8 weeks, histopathological examination was carried out to document any evidence of aftercataract. RESULT: Overall, evidence of aftercataract was seen in 6 rabbits in the control group and 3 in the Catalin group; the degree of PCO was higher in the placebo group. CONCLUSION: We found that Catalin played some role in preventing PCO.     

关于焦化废水新建处理工艺选择的探讨

介绍了焦化废水的来源及所合成分、浓度，从多个方面对新建焦化废水处理工艺进行了比较和探讨，并对用户在工程规划或工程设计选择时提出了合理化建议。     

One-to-Many: Context-Oriented Code for Concurrent Error Detection

The paper deals with context-oriented codes for concurrent error detection. We consider a fault model for which, in the presence of a fault, the values on the circuit’s output are arbitrary. This model allows one to design an error detection code without analyzing sensitive parts or error cones in the synthesized circuit. Conventional coding schemes are based on a one-to-one mapping between an original output vector (information word) and a codeword. In this paper, we introduce a different approach, which we call one-to-many coding. In one-to-many code, each codeword comprises a predefined set of words. The functional unit is referred to as an encoder enabling each activation to map an information word to a different word. This flexible mapping system results in a lower implementation cost of the functional unit and its checker.     

空气锤改造为电液锤

介绍了将空气锤改造成电液锤的经验。操控性好、节能是改造后锻锤的显著优点。     

A hazard function approximation used in reliability theory

The cumulative hazard function H(n) should accumulate to infinity over the distribution support, because the survivor function is Sf(n)=exp(-H(n)). The widely used approximation for the cumulative hazard function, H(n)≈Σ_k=1ⁿh(k), for a small value of the hazard function, h(k), can be useful and reasonably accurate for computing the survivor function. For the continuous case, assuming that pdf exists, the H(n) diverges as it should. For the discrete case, two examples show the use of the hazard function approximation. In example A for the uniform probability mass function, the approximation diverges. In example B for the geometric probability mass function, the approximation converges to the finite value, 1.606695, when it should be diverging. The result is surprising in light of the difference between the continuous case, pdf, and the discrete case, pmf. Thus in practice, the approximation must be used with caution     

紫外光谱法测定芝麻素与芝麻林素含量

本实验采用紫外分光光度法测定芝麻油中木酚素类物质芝麻素与芝麻林素的含量.根据木酚素类化合物在200～400nm紫外区有特征吸收,利用其吸收的强弱,以芝麻油中含量最高的芝麻素为对照品,通过标准曲线的绘制和假设检验,得到芝麻素的浓度与吸光度之间的显著的线性关系,由回归方程计算芝麻素的最低检测极限为1.95μg/mL,平均加样回收率为99.31%,RSD为1.87%;在提取后的40分钟内进行稳定性试验,RSD（%）为0.3%.重现性试验结果RSD为2.85%,精密度试验结果RSD为0.22%.