Design of a novel MRI compatible manipulator for image guided prostate interventions

This paper reports a novel remotely actuated manipulator for access to prostate tissue under magnetic resonance imaging guidance (APT-MRI) device, designed for use in a standard high-field MRI scanner. The device provides three-dimensional MRI guided needle placement with millimeter accuracy under physician control. Procedures enabled by this device include MRI guided needle biopsy, fiducial marker placements, and therapy delivery. Its compact size allows for use in both standard cylindrical and open configuration MRI scanners. Preliminary in vivo canine experiments and first clinical trials are reported.     

Reproduction and fetal development in mice chronically exposed to nitrous oxide

The effects of exposure to nitrous oxide on reproductive indices, fetal development, and male fertility were examined in Swiss/ICR mice. In experiment I, female mice were exposed for 4 hours per day on days 6-15 of pregnancy, to 0.5% (5,000 ppm), 5.0% (50,000 ppm), or 50% (500,000 ppm) nitrous oxide. Control mice were untreated, exposed to compressed air, or treated with retinoic acid on day 8 of gestation. In experiment II, male mice were treated, as above, for 9 weeks and then mated nightly for 7 nights to untreated, virgin females. In experiment I, 1,761 fetuses from 154 dams were examined and found to be without evidence of adverse nitrous oxide treatment effects. In experiment II there were no differences among the groups in the ability of males to impregnate females or in litter size, fetal wastage, or fetal size. When we compare nitrous oxide with other inhalation anesthetics we have studied employing a similar protocol, we find the order of reproductive toxicity to be: halothane greater than enflurane greater than methoxyflurane greater than nitrous oxide. None of the agents were toxic, however, at the trace concentrations usually found in operating rooms.     

Urethral pressure profile in prostatic surgery

Urethral pressure profile measurements were performed in 45 men suffering from micturation disturbances with the aim of evaluating the diagnostic aid of the procedure as compared to conventional urodynamic evaluation. The urethral pressure profile seems to be of value in visualizing the diseases of the prostate and the bladder neck, but it is of no definite aid except for postprostatectomy incontinence.     

Amino acid decarboxylation by bacteria of the genus erwinia under aerobic conditions]

The expression of membrane immunoglobulin (mIg) was examined in three cloned MPC11-derived mouse myeloma cell lines. Membrane immunofluorescence studies demonstrated that IgG2b producer cells (P1) had complete IgG molecules, L-chain producer (L1) had only L-chain determinants and nonproducer (NP2) did not have any Ig determinants on the cell surface. An Ig receptor, with characteristics different from B lymphocyte Fc receptor, has been found to be present on secreting cells (P1 or L1), but not on the NP2 cell variant. The data reported in the present paper indicate that the expression of mIg and of the Ig receptor molecule is clearly correlated with the process of secretion. In the light of previous data reported on Ig secretion, a model is proposed which correlates the process of secretion with the expression not only of mIg, but also of the receptor for Ig.     

Synthesis and thermodynamics of oligonucleotides containing chirally pure R(P) methylphosphonate linkages

Methylphosphonate (MP) oligodeoxynucleotides (MPOs) are metabolically stable analogs of conventional DNA containing a methyl group in place of one of the non-bonding phosphoryl oxygens. All 16 possible chiral R(P) MP dinucleotides were synthesized and derivatized for automated oligonucleotide synthesis. These dimer synthons can be used to prepare (i) all-MP linked oligonucleotides having defined R(P) chirality at every other position (R(P) chirally enriched MPOs) or (ii) alternating R(P) MP/phosphodiester backbone oligonucleotides, depending on the composition of the 3'-coupling group. Chirally pure dimer synthons were also prepared with 2'-O-methyl sugar modifications. Oligonucleotides prepared with these R(P) chiral methylphosphonate linkage synthons bind RNA with significantly higher affinity than racemic MPOs.     

印染废水超滤工艺中操作方式对过滤速率的影响

对某印染厂废水处理站排水进行了回用处理研究.在恒压条件下,采用聚乙烯(PE)中空纤维膜,进行间歇曝气扫流过滤,分析了不同操作方式对超滤速率变化的影响.结果表明曝气在超滤中能够起到防止污染的作用,解除作用于颗粒上的抽吸力后再采用曝气扫流,则能达到更好的扫流效果.周期运行与非周期运行之间的差距较大,按"曝气过滤-暂停-曝气扫流"<"不曝气过滤-暂停-曝气扫流"<"连续曝气扫流"的顺序阻力增大,因此采用周期运行方式在一定程度上可以恢复超滤速率.印染废水过滤中,在抽吸压力小于0.08 MPa的范围内,可以不考虑沉积物的压缩性.