Optimization methods in inverse problems and applications to science and engineering

Optimization and Engineering -     

Diagnostic and prognostic relevance of malignancy-associated changes in cervical smears

OBJECTIVE: For approximately 15 years, malignancy-associated changes (MACs) have been consistently found by means of high-resolution cytometry in different tissues, especially in visually normal appearing cervical cells. Their biologic nature is not yet fully understood. The aim of this investigation was to assess the expression of MACs in cervical smears and to evaluate their prognostic relevance. STUDY DESIGN: This study was performed on normal intermediate cells obtained from 53 cytologically positive and 78 cytologically negative cervical smears. From a second sample, 31 cases showing negative cytology were selected for a prospective longitudinal study. Densitometric and texture features were generated, and MACs were described on the basis of multivariate discriminant analysis. RESULTS: Discrimination between positive and negative cases was possible, with a correct classification rate of approximately 80%. After a mean period of 29.5 months, we noted no statistically significant increase in the incidence of cervical intraepithelial neoplasia in the group of healthy but MAC-positive women as compared to those who were MAC negative. CONCLUSION: MACs were constantly expressed in the epithelium of the cervix. Although their prognostic relevance remains unclear, MACs play an important role in the effort to automate cervical cytology.     

13C- and 23Na-NMR investigations on alkali cellulose

Summary Solid state ²³Na- and ¹³C-NMR spectra of alkali cellulose are presented as a function of NaOH-concentration of the steeping lye, steeping temperature and amount of adhering lye (press factor). Results are discussed with regard to chemical binding of NaOH to the cellulose chain in the system cellulose/ NaOH/H₂O.Presented at the 22nd Microsymposium, Characterization of Structure and Dynamics of Macromolecular Systems by NMR Methods, Prague, CSSR, July 20–23,1981     

Spezifische Bedarfe bei zahnärztlichen Patienten mit Demenz und ihre ethischen Implikationen

Definition of the problem

The central foundations of successful dental treatment consist of a trustful patient-dentist relationship, the professional and psychosocial expertise of the team treating the patient, and consideration of ethical aspects both during the therapeutic decision-making process and during the subsequent execution of therapy. This is especially true of the dental treatment of (mostly elder) persons with dementia, calling for an in-depth assessment of the various normative implications.

Arguments

In geriatric dentistry in particular, situational dilemmas regarding treatment often arise from specific constellations (e.?g. greatly reduced potential for dental therapy, lack of ability regarding oral hygiene and lack of individual patient responsibility) combined with an acute need for treatment and the necessary involvement of third parties. These dilemmas frequently place additional professional and normative demands on the dentist. The current contribution discusses this specific situation, first by way of theoretical discourse and subsequently with a case-related approach on the basis of two case histories.

Conclusion

It becomes clear here that classic state-of-the-art therapies are replaced by “compromise treatment” in many cases in geriatric dentistry. Such treatment follows divergent diagnostic and therapeutic rules, poses changed requirements in terms of communication and presents specific ethical challenges and pitfalls.

     

Robustness of an aerobic metabolically vinyl chloride degrading bacterial enrichment culture

Degradation of the lower chlorinated ethenes is crucial to the application of natural attenuation or in situ bioremediation on chlorinated ethene contaminated sites. Recently, within mixtures of several chloroethenes as they can occur in contaminated groundwater inhibiting effects on aerobic chloroethene degradation have been shown. The current study demonstrated that metabolic vinyl chloride (VC) degradation by an enrichment culture originating from groundwater was not affected by an equimolar concentration (50 μM) of cis-1,2-dichloroethene (cDCE). Only cDCE concentrations at a ratio of 2.4:1 (initial cDCE to VC concentration) caused minor inhibition of VC degradation. Furthermore, the degradation of VC was not affected by the presence of trans-1,2-dichloroethene (tDCE), 1,1-dichloroethene (1,1-DCE), trichloroethene (TCE), and tetrachloroethene (PCE) in equimolar concentrations (50 μM). Only cDCE and tDCE were cometabolically degraded in small amounts. The VC-degrading culture demonstrated a broad pH tolerance from 5 to 9 with an optimum between 6 and 7. Results also showed that the culture could degrade VC concentrations up to 1,800 μM (110 mg/L).     

Coherent Phonon-Induced Modulation of Charge Transfer in 2D Hybrid Perovskites

Electron–phonon interactions play an essential role in charge transport and transfer processes in semiconductors. For most structures, tailoring electron–phonon interactions for specific functionality remains elusive. Here, it is shown that, in hybrid perovskites, coherent phonon modes can be used to manipulate charge transfer. In the 2D double perovskite, (AE2T)₂AgBiI₈ (AE2T: 5,5“-diylbis(amino-ethyl)-(2,2”-(2)thiophene)), the valence band maximum derived from the [Ag_0.5Bi_0.5I₄]^2– framework lies in close proximity to the AE2T-derived HOMO level, thereby forming a type-II heterostructure. During transient absorption spectroscopy, pulsed excitation creates sustained coherent phonon modes, which periodically modulate the associated electronic levels. Thus, the energy offset at the organic–inorganic interface also oscillates periodically, providing a unique opportunity for modulation of interfacial charge transfer. Density-functional theory corroborates the mechanism and identifies specific phonon modes as likely drivers of the coherent charge transfer. These observations are a striking example of how electron–phonon interactions can be used to manipulate fundamentally important charge and energy transfer processes in hybrid perovskites.     

Changes of bone-perfusion in osteosynthesis of the femur with a marrow-nail (author's transl)

The perfusion of the bone in the hind leg after osteosynthesis (nailing of the bone-marrow) was studied. In 11 shepherd dogs (bastards) an osteotomy of the femur was done; it was treated with a marrow-nail without boring the marrow-cavity. With the "tracer-microsphere"-method the perfusion of femur, tibia and talus of both hind legs was measured. Measurements were performed before and after surgery, in 10 dogs 2 weeks and in 8 dogs 6 weeks after surgery. Immediately after the operation the perfusion was reduced considerably in all the examined bones of the operated leg. Two weeks later the perfusion was increased in all bones of both hind limbs. In the cancellous bone of the femur the perfusion reached the original preoperative values after 6 weeks; in cortical bone a further increase of the perfusion was noted. This increase was most marked in the cortical bone of the operated femur; it was less in the cortical bone of the other bones.