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Biomedical subjects

A Schöll

Publications and source records attributed to A Schöll.

At least 19 recordsLinked to original sources
PubMed2006

High-resolution inner-shell excitation spectroscopy of H2-phthalocyanine.

We report on a combined experimental and theoretical carbon and nitrogen K-edge near-edge x-ray absorption fine structure investigation on condensed metal-free phthalocyanine (H2Pc). Based on the results from improved virtual orbital calculations, all resonances in the experimental high-resolution data can be assigned to various electronic transitions. The comparison between experiments and calculations further shows that a significant influence of the core hole, which affects both the transition energies and the cross sections, is present and must be considered in theoretical approaches. Moreover, additional fine structure is clearly resolved for the first N 1s-->pi* transition, which can be interpreted as vibronic coupling to the electronic core excitation.

Journal Article↗
PubMed2004

Line shapes and satellites in high-resolution x-ray photoelectron spectra of large pi-conjugated organic molecules.

We present a high-resolution C1s and O1 s x-ray photoemission (XPS) study for condensed films of pi-conjugated organic molecules, namely, of the anhydrides 3,4,9,10-perylene-tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene-tetracarboxylic acid dianhydride, 1,8-naphthalene dicarboxylic acid anhydride, and benzoperylene-(1,8)-dicarboxylic acid anhydride as well as the quinoic acenaphthenequinone. Although the functional groups are identical for the anhydrides, the molecules show very different photoemission fine structure thus providing a detailed fingerprint. A simultaneous peak fit analysis of the XPS spectra of all molecules allows to consistently determine the ionization potentials of all chemically different carbon and oxygen atoms. Additional structures in the C1s and O1s spectra are interpreted as shakeup satellites and assigned with the help of singles and doubles configuration interaction calculations. These satellites provide further information on multielectron excitations and must be taken into account for quantitative investigations.

Journal Article↗
PubMed2004

Electron-vibron coupling in high-resolution X-Ray absorption spectra of organic materials: NTCDA on Ag(111).

We report additional rich fine structures in high-resolution near-edge x-ray-absorption fine structure (NEXAFS) spectra of large organic molecules using NTCDA on Ag(111) as an example. These fine structures are completely interpreted as vibronic coupling to electronic core excitations. The coupling is mode selective; predominantly one vibronic mode couples to each excitation. The fit results suggest the occurrence of a Davydov splitting, first observed for core excitons. Morphological differences substantially influence the electron-vibron coupling, indicating a strong intermolecular interaction. Thus NEXAFS becomes a more subtle probe for organic solids.

Journal Article↗
PubMed1988

[Fatal complication of fine-needle biopsy of the liver].

A 62-year-old woman with cirrhosis of the liver was suspected of also having a primary liver-cell carcinoma. After puncture of a circumscribed liver process with a biopsy fine-needle there occurred massive bleeding which could not be surgically stopped, and the patient died. This was the first fatal outcome among 2760 fine-needle punctures in the author's personal series (0.036%).

Biopsy, Needle↗
PubMed1980

Cytological tumour diagnosis in maxillo-facial surgery examinations using the fine needle aspiration technique.

Based on the question of whether fine needle aspiration cytology may also be successfully applied in the area of maxillo-facial surgery, appropriate investigations were carried out on 121 patients showing definitely localizable tumours in this area. The cytological findings of 107 aspiration biopsies were successfully compared with the results of histological examinations. This comparison showed an agreement between the cytological and histological diagnoses in 75.7 % (n = 81) of the tumours examined. No agreement with histological results due to insufficient aspirates was found in 16.8% (n = 18) of all cases, and for 7.5% (n = 8), cytological results permitted only the suspicion of the presence of a certain tumour. Results of the investigation indicates that fine needle aspiration cytology can in principle also be used effectively in the diagnosis of tumours in the oral, jaw bone and facial region. Further cytological inverstigations are still necessary to confirm the morphological basis for the cytological diagnosis of these tumours. The advantages of the uncomplicated diagnostic method are pointed out.

Biopsy, Needle↗
PubMed1979

[On the value of drill biopsy in diagnosis of breast lesions (author's transl)].

During a period of 30 months 216 drill biopsies of palpable breast lesions were carried out. By using this method sufficient tissue material for a histological examination could be acquired in all cases. Out of 106 cases, in which the histological results could exactly be proved by following excision biopsy or mastectomy, 87% were correctly diagnosed by drill biopsy. The reason for failure in all of the 14 false drill biopsy diagnoses was due to sampling error. Comparing the diagnostic results of the first 15 month after establishing the method, with the second half of the investigation period, a considerable improvement from 80% to 94% of correct diagnoses could be established. This improvement was based on increasing experience and routine. By means of drill biopsy, cosmetically and diagnostically disturbing scar formation could be avoided. Drill biopsy can be carried out in local anaesthesia and on outpatient basis as well. It is also suitable for frozen-section technique.

Biopsy, Needle↗
PubMed1978

[Rupture of the aorta complicating multiple injuries (author's transl)].

A case of subtotal circumferential rupture of the aorta is described which involved a woman who had sustained multiple injuries in a traffic accident. The rupture was discovered only during autopsy. As this type of injury is generally not diagnosed until after death, knowledge of some of the characteristics signs of rupture of the aorta is important, especially to the physician in charge of an intensive care unit. If there are suspicious signs aortography is essential. The only treatment likely to succeed is surgery, but postoperative mortality is still as high as 20--40 per cent.

Accidents, Traffic↗
PubMed1975

Histometrical glomerular studies in minimal proliferative intercapillary glomerulonephritis (minimal changes without nephrotic syndrome) with different clinical symptomatology.

Histometrical glomerular studies were carried out in minimal proliferative intercapillary glomerulonephritis (minimal changes without nephrotic syndrome) with different clinical symptomatology. Results of morphometric examinations of renal corpuscles of 58 cases of minimal proliferative ntercapillary glomerulonephritis (MPI-GN) without nephrotic syndrome were compared with those of normal and mesangiosproliferative glomerulonephritis cases and showed that MPI-GN without nephrotic syndrome is accompanied by proliferation of the glomerular cells. The cell density in the glomeruli is increased by 47% compared with the norm. Different clinical symptoms (proteinuria, haematuria, haematuria and proteinuria) have no different morphometrical correlate. A differentiation of this disease from mesangio-proliferative glomerulonephritis seems justified.

Diagnosis, Differential↗
PubMed1975

[Peroral intestinal mucosal biopsies. Comparative studies on the histological and the dissecting microscope findings (author's transl)].

From 1969 to 1973 171 peroral intestinal biopsies were carried out at the Children's Hospital Tübingen using the Crosby-Kugler capsule and the Watson intestinal biopsy capsule of paediatric size. The dissecting microscope findings were compared with the histological findings. The former correlated in stage II and III, according to the Shmerling scale, with the histological findings. Findings under the dissecting microscope, stage I, did not correlate in all cases with the histological findings. It is supposed that this results from either an inaccurate orientation or from inadequate sectioning. The plane of sectioning must be parallel to the villi. If the plane of sectioning is not parallel to the villi, the slender villi under the dissecting microscope look like plump villi when examined histologically. It is supposed that this results in a greater number of plump villi and a smaller number of slender villi in the histological findings compared with the dissecting microscope findings. The correspondence of slender villi examined under the dissecting microscope and those which are histologically examined in about 25 to 100%.

Biopsy, Needle↗