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Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) usually employs highly crystalline small-molecule matrices, and the analyte is interpreted as being co-crystallized with the matrix. We recently showed that semi-crystalline polymers are efficient matrices for the detection of low-molecular-weight compounds (LMWCs) in MALDI MS and MALDI MS Imaging, and are dual-mode, i. e., enabling both positive and negative modes. The matrix performances of two fluorene/napthalene diimide co-polymers P(TNDIT-Fl(C 4 C 2 )) and P(TNDIT-Fl(C 10 C 8 )) were investigated and compared. Both are fully amorphous according to XRD measurements, show high relative absorption values at the wavelength of common MALDI lasers (λ Nd:YAG =355 nm: C 4 C 2 =73 %; C 10 C 8 =67 %), and are solution processable. As matrices, they are dual-mode, and enable the detection of LMWCs while being mostly MALDI-silent. Compared with semicrystalline polymer matrices, the amorphous matrices give similar or better signal intensities, thus indicating that analyte inclusion takes place in the amorphous part of the polymer matrix., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) and MALDI MS imaging are ubiquitous analytical methods in medical, pharmaceutical, biological, and environmental research. Currently, there is a strong interest in the investigation of low molecular weight compounds (LMWCs), especially to trace and understand metabolic pathways, requiring the development of new matrix systems that have favorable optical properties and a high ionization efficiency and that are MALDI silent in the LMWC area. In this paper, five conjugated polymers, poly{[ N, N'-bis(2-octyldodecyl)-naphtalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]- alt-5,5'(2,2'-bithiophene)} (PNDI(T2)), poly(3-dodecylthiophene-2,5-diyl) (P3DDT), poly{[2,3-bis(3-octyloxyphenyl)quinoxaline-5,8-diyl]- alt-(thiophene-2,5-diyl)} (PTQ1), poly{[ N, N'-bis(2-octyldodecyl)-isoindigo-5,5'-diyl] -alt-5,5'(2,2'-bithiophene)} (PII(T2)), and poly(9,9-di- n-octylfluorenyl-2,7-diyl) (P9OFl) are investigated as matrices. The polymers have a strong optical absorption, are solution processable, and can be coated into thin films, allowing a vast reduction in the amount of matrix used. All investigated polymers function as matrices in both positive and negative mode MALDI, classifying them as rare dual-mode matrices, and show a very good analyte ionization ability in both modes. PNDI(T2), P3DDT, PTQ1, and PII(T2) are MALDI silent in the full measurement range (> m/ z = 150k), except at high laser intensities. In MALDI MS experiments of single analytes and a complex biological sample, the performance of the polymers was found to be as good as two commonly used matrices (2,5-DHB for positive and 9AA for negative mode measurements). The detection limit of two standard analytes was determined as being below 164 pmol for reserpine and below 245 pmol for cholic acid. Additionally P3DDT was used successfully in first MALDI MS imaging experiments allowing the visualization of the tissue morphology of rat brain sections.

The busy atmosphere and routine of a hospital is apt to induce apprehension in a patient about to have a surgical operation. To calm and reassure him and relieve his anxiety is an important part of the anaesthetist's work.

Since 1970 all postoperative bacteriological findings recorded in surgical patients have been analyzed and compared with the postoperative course. There are also regular checks of bacterial invasion in the operating suites and in the intensive care units. By such means as systems of double lock for personnel and equipment, regular surface disinfection, frequent hand disinfection, cleaning of the respirators with antiseptics, etc., the authors have been able to reduce the incidence of hospital infection very drastically. These measures also almost eliminated cross-infections in patients on long-term ventilation and complications with long-term indwelling catheters.

Postoperative parenteral nutrition can only be optimally effective if the characteristics of post-traumatic metabolism are taken into account. Two main possibilities are discussed for the carbohydrate component of parenteral nutrition during this phase: glucose with high doses of insulin or non-glucose carbohydrates (sugar substitutes) possibly in a suitable combination with glucose. The risks as well as the technical and organisational problems involved in the use of them are discussed and the authors prefer the second of the two alternatives. Possible side effects of non-glucose carbohydrates are pointed out and it is shown how these can be avoided by observing dose guidelines. So far a combination of frucose : glucose : xylitol in a ratio of 2 : 1 :1 with a total dose of 0.50 g/kg/hour has been studied most thoroughly. This combination normalises the fat metabolism and improves glucose tolerance without requiring exogenous insulin. Experiences with this combination as well as individual non-glucose carbohydrates on operated patients have been given continuously for up to 7 days and in some cases even for several weeks. No side effects, no deviations from a steady state and no abnormal changes of the laboratory values occurred. The authors are of the opinion that non glucose carbohydrates are necessary if the facilities for frequent blood sugar controls are not available.

The decision as to operability and fitness for anaesthesia must be made jointly by the surgeon and the anaesthesiologist and only by them. They arrange for the required diagnostic and therapeutic measures to be taken to assure the success of the operation. The advice of other specialists as to the treatment of disorders unconnected with the primary disease does not extend to questions regarding operability and fitness for anaesthesia. The preparation of out-patients for surgery requires particular care on the part of the anaesthesiologist. A detailed pre-operative explanation to the patient of what is involved will greatly help to relieve the patient's anxiety.

With Vivasorb, the surgical patient's full alimentation can be maintained up to a few hours before the operation. In the postoperative phase, the nitrogen balance of patients having undergone minor surgical intervention and in a state of moderate catabolism can be kept under control in a slightly negative range by the exclusive administration of Vivasorb. In patients with more severe catabolism, the oral supply of Vivasorb cannot fully replace parenteral nutrition, it can, however, support it.