石灰拜尔法溶出工艺的探讨

针对我国氧化铝生产的实际情况,提出采用石灰拜尔法提高我国氧化铝生产水平的必要性.研究了管道化溶出生产工艺条件下,矿石A/S为10.53和7.59时石灰添加量对溶出赤泥N/S、A/S和赤泥产出率、矿石溶出速度、溶出液硅量指数的影响,探索了适合河南分公司中品位矿石的石灰拜尔法溶出条件.     

Importance of the colon in enteric hyperoxaluria

To investigate the role of the colon in increased oxalate absorption, we measured urinary oxalate and fecal fat excretion in 26 patients with gastrointestinal disease. Eight patients with steatorrhea of various causes (Crohn's disease [two], chronic pancreatitis [four], jejunoileal bypass [one] and extrahepatic biliary obstruction [one]) had hyperoxaluria (greater than 45 mg per 24 hours). All these patients had intact colons. In contrast, none of five patients with ileostomies and steatorrhea secondary to ileal resection had hyperoxaluria. Absorption of 14C-oxalate was increased in three patients with steatorrhea and intact colons but not in three patients with steatorrhea and an ileostomy. Thus, the colon is both the site of and required for increased oxalate absorption in enteric hyperoxaluria. The lack of a direct relation between fecal fat excretion and urinary oxalate excretion in the patients with hyperoxaluria and steatorrhea suggests that steatorrhea, although important, is not the only determinant in the pathogenesis of hyperoxaluria.     

烧结溶解法制备多孔铝材料的工艺特性研究

以纯Al粉、纯Mg粉和水溶性造孔剂为原料,利用烧结溶解法制备多孔铝材料,通过真空烧结和热压烧结两种方式,研究烧结工艺和Mg的添加对多孔铝烧结致密化及其孔结构的影响。采用扫描电子显微镜(scanning electron microscope,SEM)和X射线衍射仪(X-ray diffractometer,XRD)等设备分析多孔铝的显微组织和相成分,利用万能力学试验机和显微硬度仪等仪器检测多孔铝的压缩强度和显微硬度。结果表明:升高烧结温度和延长烧结时间均有利于多孔铝骨架的致密;随烧结温度的升高,孔隙边缘由尖锐逐渐变得圆滑;Mg的添加可破除Al颗粒表面氧化膜,并生成MgAl_2O_4尖晶石,促进烧结致密化和孔结构收缩,进而提升多孔铝的力学性能。     

氧化铝生产过程中溶出工艺流程的改进研究

有色金属铝是目前消耗量最大的金属原材料,且每年的消耗量在持续的增加。制备以及获取金属铝材料的主要方法是从氧土矿石中提取氧化铝,以此将氧化铝转换为原材料金属铝。通过对原有的氧化铝溶出工艺进行探究,找出工艺流程中的问题,并从加强矿源规范管理、提高硅量指标、避免有机物对碳酸钠结晶变性的影响、避免过多碳酸钠、硫酸钠的积累、建立应急机制等方面对其进行改进,提高氧化铝的生产质量和效率,从而减少能源的浪费以及对环境的污染。     

Inhalation route for administration of systemic drugs

A complex medical field such as Child and Adolescent Psychiatry can only meet the expanding problems of quality management by multi-disciplinary cooperation. The quality control circle is the central element of the quality control process and of further advances to quality management. In a critical experience-report the concepts, practical issues and further questions of a continuing quality management conference at a University hospital are outlined. It concentrates on practical and process-oriented problems that concern the integration of quality management in practice and research.     

Inhibition of intratracheal lung cancer development by systemic delivery of E1A

Amplification or overexpression of HER-2/neu in human lung cancer has been correlated with poor prognosis and chemoresistance. We have previously reported that the adenovirus type 5 early region 1A (E1A) gene product can suppress HER-2/neu-mediated transformation phenotypes through inhibition of HER-2/neu expression. To find an efficient way to treat HER-2/neu-overexpressing lung cancer with E1A, a replication-deficient adenovirus containing the E1A gene, Ad.E1A(+), was used to transduce E1A into HER-2/neu-overexpressing and low expressing human lung cancer cell lines. Tumour cell growth in vitro and colony formation in soft agarose were greatly inhibited by Ad.E1A(+) transduction in HER-2/neu-overexpressing lung cancer cell lines. In HER-2/neu low expressing cell lines, E1A could not inhibit cell growth in vitro but could reduce the colony formation ability in soft agarose, indicating different effects of E1A in these two types of cancer cells. To test the therapeutic efficacy of E1A to lung cancer by systemic delivery in vivo, tumor-bearing mice were established by intratracheal injection of lung cancer cells and treated by i.v. tail injections of Ad.E1A(+). As a result, Ad.E1A(+) suppressed HER-2/neu overexpression and inhibited intratracheal lung cancer growth. However, no significant tumor suppression effect of Ad.E1A(+) was observed in mice bearing HER-2/neu low expressing cell line when the same therapeutic procedure was followed. Thus, we conclude that systemic delivery of Ad.E1A(+) can efficiently achieve therapeutic effect in HER-2/neu-overexpressing lung cancer in vivo.     

Rate of tetracycline dissolution from tablets and capsules and the biological availability of the antibiotic

Relation between the rate of tetracycline dissolution from tablets and capsules and the biological acceptibility of the antibiotic in the host was studied. The antibiotic dissolution rate from the pharmaceutical forms was determined in a modernized apparatus "Rotary basket" in water, the speed of the basket rotation was 200 r.p.m. In addition the tetracycline blood levels in patients treated with the drug in the above pharmaceutical forms were estimated. It was found that the rate of the antibiotic dissolution characterized the antibiotic biological acceptibility. A test for the dissolution rate was developed. It may be used for estimation of production batches of tetracycline tablets.     

Importance of hepatic first-pass removal in metastasis of colon carcinoma cells

BACKGROUND/AIMS: It might be thought that colon carcinoma tends to metastasize to the liver because tumor cells leaving the primary colon tumor pass initially through the liver. Therefore we elucidated the kinetics of tumor cells in the body in order to understand the effect of the location of the liver on hepatic metastasis, that is to examine the hepatic first-pass effect of tumor cells. METHODS: Based on a physiological kinetic model, we examined quantitatively the hepatic metastasis and hepatic distribution of KM12-H1X cells administered by different routes. RESULTS: Both the number and incidence of colonies of hepatic metastasis were much greater after intrasplenic injection than after intravenous injection. The distribution of radioactivity to the liver after intrasplenic injection of [3H] thymidine-labeled cells was also much higher than that after intravenous injection. The number of colonies of hepatic metastasis correlated well with the area under the curve of the distributed amount of the tumor cells in the liver, regardless of the injection route; the correlation line was identical for each injection route. CONCLUSIONS: These results suggest that the hepatic first-pass effect is an important factor for the hepatic metastasis and that the cumulative number of tumor cells distributed in the liver is a determining factor for the degree of metastasis. Mathematical analysis based on a physiological model also suggests that hepatic metastasis depends on hepatic first-pass trapping of tumor cells.     

Development of drug delivery systems for macromolecular drugs

With a rapid progress in biotechnology, a variety of endogenous macromolecular substances have become a novel class of therapeutic agents. This review will focus on the development of delivery systems for macromolecular drugs. Current status and future perspectives in this research field are reviewed mainly based on the results obtained in our laboratory. First of all, we studied pharmacokinetic characteristics of macromolecules in relation to their physicochemical properties such as molecular weight and electric charge. Based on this information, we first developed macromolecular prodrugs as a delivery system for low molecular weight drugs. An antitumor antibiotic, mitomycin C (MMC) were covalently conjugated with dextran and various types of macromolecular prodrug of MMC were developed for tumor targeting. Secondly, delivery systems for protein drugs such as soybean trypsin inhibitor, uricase, and recombinant superoxide dismutase (SOD) were developed. In particular, successful targeting of SOD to the liver, kidney and blood circulation was achieved by chemical modification of the protein drug. Finally, we have been trying to develop delivery systems for nucleic acid drugs involving antisense oligonucleotides and plasmid DNA. Prior to the development of delivery systems, we found that the pharmacokinetics of the nucleic acid drugs are decided by their physicochemical properties as polyanions even if these materials contain genetic information. Several approaches were tested to control the in vivo behavior of the oligonucleotides and plasmid DNA based on the finding. Thus, we have established the strategy for rational design of delivery systems for various types of macromolecular drugs based on the pharmacokinetic considerations. This methodology can be a formidable tool for the development of clinically applicable macromolecular drugs.     

Static and dynamic energy absorption of Al foams produced by the sintering and dissolution process

This article investigates the effects of the processing conditions of the novel sintering and dissolution process (SDP), including sintering temperature, sintering time, Mg addition, and cell size, on the capacities of the as-processed Al foams for static and dynamic energy absorption. While higher temperatures generally promote better bonding between the Al particles during sintering and, therefore, improved energy-absorption capacities, there exist optimum sintering times and cell-size ranges for producing Al foams with the best energy-absorption characteristics. The optimum sintering time increases when the sintering temperature or the relative density is decreased. The addition of a small amount of Mg powder to the Al/NaCl compact can enhance the sintering markedly and increase the energy-absorbing capacity of the foam by up to 50 pct. For any Al foam, the energy absorbed in the static condition is much greater than that in the dynamic condition. The mechanisms of these effects are also discussed.     

炼钢流程钢中氮的溶解及控制技术

 氮作为钢中典型的常存元素,其含量对钢产品性能有重要影响。炼钢生产过程中,由于钢液裸露容易导致增氮,或者钢液成分不同、操作不当等使含氮合金中氮的收得率不稳定等,这些因素都会使钢液中的氮含量产生明显波动,导致成品钢材性能不稳定。因此,氮的精准控制已成为控氮钢种或含氮钢种生产中的关键问题,分析了钢中氮的来源,阐释了钢液氮溶解热力学和动力学,综述了炼钢生产流程中钢液氮变化、控氮研究现状及技术措施等,提出炼钢流程中钢液氮精准控制发展方向。     

板坯连铸机动态轻压下过程控制系统的高可用性实现

阐述了梅钢2#板坯连铸机动态轻压下过程控制系统的高可用性架构过程,提出了一种软件故障自主恢复与硬件热备冗余相结合的高可用性系统架构方案,并结合实际生产过程分析了备机切换过程中检查点数据的可用性,最后给出了系统故障测试结果。实际表明,系统投产以后运行稳定,达到了预期目标。     

Importance of abnormal fetal presentation of twins during labor and delivery

Utilizing the 18 year material of two institutions, the author investigated the effect of fetal lie and presentation on the labor and delivery process. Out of 541 pairs of twins, in 299 instances (55.27%) at least one of the fetuses occupied a transverse lie or presented by the breech. In the remaining 242 pairs (44.73%), both fetuses presented by the vertex. In association with premature labor, out of 239 sets of twins, in 134 instances (56.07%), the presentation of at least one of the twins was abnormal. The same phenomenon occurred in 165 out of 302 pairs (54.63%) when labor set in at term. The percentual frequency of abnormal presentations appeared to be positively related to maternal age and parity. In connection with abnormal presentations, there was an increase in the rate of cesarean sections (38.13% versus 13.21%) and that of low Apgar scores (18.18% versus 9.3%), as compared to those cases where both fetuses presented by the vertex. Of all cases of perinatal mortality, 57.76% involved twin pairs with abnormal presentation versus 42.24% for cases where both fetuses presented by the vertex.     

Cisplatin delivery by biodegradable polymer implant is superior to systemic delivery by osmotic pump or i.p. injection in tumor-bearing mice

The use of biodegradable polymer implants to deliver cisplatin was compared with delivery by systemic injection and by osmotic pump. Drug levels in the tumor were found to be higher than those in the blood and kidney when the drug was delivered using the polymer implant. In contrast, for the other two delivery methods blood and kidney cisplatin levels were greater than those in the tumor. It has been previously shown that tumor response, in terms of growth delay, was greatest when drug was delivered by polymer implant and least when treatment was by osmotic pump.     

New systemic drugs in the treatment of gastrointestinal cancer

Our objective was to study the antibody response to the parotiditis, rubella, measles and tetanus vaccines in HIV infected children. Forty-four children of HIV positive mothers, of which 14 were infected (SG) and 33 HIV negative (CG) were studied when they were between 2 and 3 years of age. Their response to vaccinations of four doses of tetanus toxoid and one dose of measles, rubella and parotiditis vaccines was assessed. Children in the SG were tested at the age of 5-6 years to study the evolution of the response. At the age of 2-3 years, all children had optimal protection against tetanus toxoid. The response to measles, parotiditis and rubella was poor (adequate levels of antibodies in 50%, 25% and 21%, respectively) in infected children and good (93%, 75% and 90%, respectively) in the CG. At 5-6 years of age, a decreased level of antitetanus antibodies were found in the SG, maintaining low protection levels. There was no evidence of any changes in the response to measles, while the number of cases with a good response to parotiditis and rubella increased. Further results are necessary to know the effectiveness of the booster. We conclude that: 1) The immunological response to vaccination is poor in HIV infected children. 2) There was no evidence of side effects or changes in the HIV symptoms after vaccination.     

Studies on transdermal delivery system of dihydroetorphine hydrochloride

A transdermal delivery system of dihydroetorphine hydrochloride (DHE-TDS) was developed. The DHE-TDS mainly composed of polyvinyl alcohol, polyvinyl pyrrolidone and lactose. Tests on rabbits showed only slight skin irritation according to federal hazardous substances act. By giving DHE-TDS to rabbits, DHE release was shown to be governed by first-order mechanism. When DHE-TDS was given to Wistar rats, a relatively stable blood drug concentration was observed from 4-32 h after drug administration. Writhing tests showed that one dose of DHE-TDS would maintain the narcotic action on rats for at least 48 h.