Description of a coverslip holder for,and observations on,the critical point drying of cell cultures

The elimination of artefact during the preparation of cell cultures for scanning electron microscopy is difficult. Collapse of cellular projections, cytoplasmic cracks, perforations and fracturing of cell-cell processes and cell-substrate attachments occur during fixation, dehydration and critical point drying. Coating and storage may cause further artefact. A specimen holder which serves to minimize turbulence in the critical point dryer and which allows for the simultaneous processing of up to five coverslips, as well as a reproducible technique for the preparation of cell cultures are described.     

Patient attitude as a function of disease state in multiple sclerosis

The present study investigated the attitude of 243 patients with Multiple Sclerosis (MS) as a function of their perceived disease state. Data was collected via a closed-format questionnaire developed through the Fishbein and Ajzen [1-3] Theory of Reasoned Action. Results indicated clearly that patients with MS are not an homogenous group and vary in characteristics across disease states and that disease state differentially affects the psycho-social attitudes of patients. Results also indicated that persons in remission were more positive in their attitude associated with their disease state than persons with a chronic progressive form of the disease.     

Virtual surgery in a (tele-)radiology framework

Presents telemedicine as an extension of a teleradiology framework through tools for virtual surgery. To classify the described methods and applications, the research field of virtual reality (VR) is broadly reviewed. Differences with respect to technical equipment, methodological requirements and areas of application are pointed out. VR, desktop VR and augmented reality are differentiated and discussed in some typical contexts of diagnostic support, surgical planning, therapeutic procedures, simulation and training. Visualization techniques are compared as a prerequisite for VR and assigned to distinct levels of immersion. The advantage of a hybrid visualization kernel is emphasized with respect to the desktop VR applications that are subsequently shown. Moreover, software design aspects are considered by outlining functional openness in the architecture of the host system. A teleradiology workstation was extended by dedicated tools for surgical planning through a plug-in mechanism. Examples of recent areas of application are introduced, such as liver tumor resection planning, diagnostic support in heart surgery, and craniofacial surgery planning. In the future, surgical planning systems will become more important. They will benefit from improvements in image acquisition and communication, new image processing approaches and techniques for data presentation. This will facilitate pre-operative planning and intra-operative applications     

The size distribution of starch granules in endosperm of different sized kernels of the wheat cultivar maris huntsman

The particle size distributions of starches prepared by proteolysis from different sized kernels of Maris Huntsman wheat, were determined by Coulter Counter. The number of starch granules was greater in “large plump” kernels than in “small plump” and “shrivelled” kernels grown under the same conditions. In all three kernel types more than one third of the total starch weight was contributed by granules less than 10 μm diameter (B type granules). The proportion of these small granules was significantly greater in “large plump” kernels than in the other two types.     

Thin film pseudomorphicAlAs/In0.53Ga0.47As/InAs resonant tunnellingdiodes integrated onto Si substrates

We report high peak-to-valley current ratio (PVR) resonant tunneling diodes (RTDs) bonded to silicon. Pseudomorphic AlAs/In_0.53Ga_0.47As/InAs resonant tunneling diode structures grown on semi-insulating InP with peak-to-valley current ratios as high as 30 at 300 K have been separated from the growth substrate and bonded to silicon substrates coated with Si₃N ₄, forming thin film devices. In addition, thin film multiple stack RTD structures have been bonded to silicon substrates. The I-V characteristics of both the single and multi-stacked thin film RTD's exhibit no signs of degradation after bonding to the host substrate. These results are the first successful demonstration of InP based electronics bonded to a silicon host substrate and enable the integration of RTDs with conventional silicon circuitry     

A comparison of 2 modes of administration of recombinant interleukin-2: continuous intravenous infusion alone versus subcutaneous administration plus interferon alpha in patients with advanced renal cell carcinoma

PURPOSE: To compare 2 treatment modalities with recombinant Interleukin-2 (rIL-2) for patients with advanced Renal Cell carcinoma (RCC): continuous intravenous infusion (CIV) alone versus subcutaneous (s/c) rIL-2 + Interferon-alpha (IFN-alpha). PATIENTS AND METHODS: Data have been collected on 425 patients with RCC, treated CIV rIL-2 alone, (225 patients), or rIL-2 by the s/c route (200 patients). Patients receiving s/c rIL-2 also received s/c IFN-alpha both drugs being administered on an outpatient basis. Patients receiving CIV rIL-2 were treated as inpatients. Patient eligibility criteria were similar on all studies, and included patients with progressive, advanced disease, but with an ambulatory performance status. RESULTS: The overall response rate for the CIV schedules was not significantly different from the s/c regimens: 15% (95% confidence limits (CL) 10-20%) vs 20% (95%CL 14-26%) with 4% CR in both approaches. Durable responses were seen in both CIV and s/c schedules and there was no evidence of a significant difference in survival in multivariate analysis. There was however an important shift in the toxicity profile. The s/c regimens do not induce a clinically detectable capillary leak syndrome, which is the dose limiting toxicity for CIV regimens. CONCLUSION: Although the introduction of CIV regimens of rIL-2 was a major step forward compared to high-dose bolus, because most patients could be treated in a normal oncology ward, the s/c schedule of rIL-2 + IFN-alpha offers the possibility of outpatient (home) therapy, with no evidence of a reduction in efficacy.     

Untersuchungen und Betrachtungen zur Anwendung von Kunststoffen für Lebensmittel XVI. Mitteilung: Diffusionsvorgänge an PVC-Schläuchen für Lebensmittel

Investigations into and considerations concerning the use of plastics in contact with foodstuffs. XVIth Communication: Diffusion processes in PVC hoses for food products Milk hoses of PVC react with the constituents of milk and – during the subsequent cleaning operations – also with water and cleaning solutions. The diffusion processes taking place in this connection are studied with the aid of specially designed simulating methods (rotating, milk- filled annular hose, testing apparatus reproducing the operation and cleaning of milking machines). After the tests one has determined in particular the transition of plasticiser into the liquid and the transition of fat into the plastic material, while in the case of cleaning solutions the water absorption by the plastic has been determined. The loss of plasticiser and the absorption of fatty materials depend primarily from the swelling condition of the PVC: the higher the swelling of the plastic, the easier the loss of plasticiser. During the contact with milk the then existing fatty film on the plastic inhibits water absorption, but this effect is eliminated by the cleaning operations. With increasing time embrittlement connected with cracking is observed.     

An Absolute Viscometer-Densimeter and Measurements of the Viscosity of Nitrogen, Methane, Helium, Neon, Argon, and Krypton over a Wide Range of Density and Temperature

An apparatus for the simultaneous measurement of viscosity and density of fluids is presented. The viscometer-densimeter covers a viscosity range up to 150 µPas and a density range up to 2000 kgm^–3 at temperatures from 233 to 523 K and pressures up to 30 MPa. Very accurate density measurements with uncertainties of ±0.02 to ±0.05% have always been carried out with this apparatus, although in its first version it was necessary to calibrate the viscosity measuring system on a reference fluid in order to achieve uncertainties of ±0.6 to ±1.0% in viscosity. After significant improvements, the apparatus now achieves uncertainties in viscosity of less than ±0.15% in the dilute gas region and less than ±0.4% for higher densities. Moreover, the viscosity measuring system can be described in an absolute way; calibration is no longer necessary. In order to test the advanced apparatus and to determine viscosity-density values of very high quality, comprehensive measurements on nitrogen, argon, and methane were carried out in the entire working range of the viscometer-densimeter. In addition, viscosity-density measurements on helium, neon, and krypton were made on two selected isotherms each. All measurements show that the estimated total uncertainty of ±0.15 to ±0.4% in viscosity and of ±0.02 to ±0.05% in density is clearly met. In order to verify the results of the combined viscometer-densimeter, a new apparatus for very accurate viscosity measurements was designed. While the working range of this apparatus is restricted to the dilute gas region, it yields uncertainties of less than ±0.07% in viscosity. Measurements carried out with this apparatus confirmed the previously measured values of the combined viscometer-densimeter within ±0.03%.