Elimination of the Translational Kinetic Energy Contamination in pre-Born-Oppenheimer Calculations

In this paper we present a simple strategy for the elimination of the translational kinetic energy contamination of the total energy in pre-Born--Oppenheimer calculations carried out in laboratory-fixed Cartesian coordinates (LFCCs). The simple expressions for the coordinates and the operators are thus preserved throughout the calculations, while the mathematical form and the parametrisation of the basis functions are chosen so that the translational and rotational invariances are respected. The basis functions are constructed using explicitly correlated Gaussian functions (ECGs) and the global vector representation. First, we observe that it is not possible to parametrise the ECGs so that the system is at rest in LFCCs and at the same time the basis functions are square-integrable with a non-vanishing norm. Then, we work out a practical strategy to circumvent this problem by making use of the properties of the linear transformation between the LFCCs and translationally invariant and center-of-mass Cartesian coordinates as well as the transformation properties of the corresponding basis function parameter matrices. By exploiting these formal mathematical relationships we can identify and separate the translational contamination terms in the matrix representation of the kinetic energy operator in the LFCC formalism. We present numerical examples for the translational contamination and its elimination for the two lowest rotational energy levels of the singlet hydrogen molecule, corresponding to para- and ortho-H2, respectively, treated as four-particle quantum systems

Breathing straws

Following nasal, septal or endoscopic surgery, it is common practice to insert nasal packs in both nasal cavities to achieve haemostasis, if there has been any bleeding at the end of the procedure. However, such packs make it difficult for patients to breathe, mainly in the first post-operative night which leads to discomfort and poor sleep. To enable patients to breathe better with nasal packs in situ, we describe a simple technique using trimmed straws and wrapped Netcell® packs for post-operative care following septal surgery, rhinoplasty and endoscopic sinus surgery. These packs also assist suction of any blood or mucous from the post-nasal spac

Perforatationstrauma im Gesichtsschädel: Eine ungewöhnliche Verletzung beim Skifahren

Zusammenfassung: Pfählungsverletzungen am Kopf und im Gesicht sind selten. Wir berichten über den Fall eines 48-jährigen Patienten, der sich beim Skifahren eine Pfählungsverletzung des Gesichtschädels mit einem 11cm langen Ast zugezogen hatte. Der Patient präsentierte sich bei der Einlieferung in die Klinik neurologisch unauffällig und kreislaufstabil. In den CT-Untersuchungen des Kopfs konnten Frakturen im Gesichtschädel und ein 11cm langer Fremdkörper, ausgehend vom Sinus maxillaris durch den Gesichtschädel bis paravertebral reichend, ohne Verletzung von Gefäßen nachgewiesen werden. Zusätzlich zog sich der Patient Frakturen an der Hand und an den Rippen zu. Er wurde in ein Zentrum für Kiefer- und Gesichtschirurgie verlegt, mehrfach operiert und konnte 8Monate nach dem Unfall wieder in sein gewohntes privates und berufliches Leben zurückkehre

Focal neuromyotonia: do I love you?

We present a rare case of focal neuromyotonia in a 73-year-old woman with a follow up of 5years. The clinical picture showed a fixed contraction of the 3rd and 4th finger of the left hand. Similar to other published cases, our patient suffered from COPD and was treated with beta-2-sympathomimetics. This clinical picture shows a rare but rather salient differential diagnosis of Dupuytren's contracture. EMG of the affected muscles may yield a diagnosis and prevent the patient from a long and ineffective treatment "odyssey

Perforatationstrauma im Gesichtsschädel. Eine ungewöhnliche Verletzung beim Skifahren

Facial perforation injuries are very rare. We describe a case of a 48-year-old man who sustained a perforation trauma from an 11 cm long wooden tree branch in the middle of the face in a skiing accident. He suffered from additional injuries, such as fractures of the ribs and hand, but was neurologically without pathologic findings and was cardiopulmonary stable.The branch penetrated the head from the sinus maxillaris through the maxilla just missing the internal and external carotid arteries and ending just short of the cervical vertebra. The patient was transported to a center for oral and maxillofacial surgery and underwent several operations.He could return to his normal social and professional life 8 months after the accident

Minimal-invasive, ballonassistierte Aufrichtung und innere Fixation von Tibiaplateaufrakturen

Zusammenfassung: Aufgrund der häufig insuffizienten Weichteilsituation im Rahmen von Tibiaplateaufrakturen und der damit assoziierten höheren Rate an postoperativen Wundheilungsstörungen und Weichteilinfektionen ist ihre operative Behandlung nicht selten eine herausfordernde Aufgabe. Die klassische offene Reposition und Plattenosteosynthese beinhaltet eine ausgiebige Weichteilpräparation und partielle Periostablösung, um so die abgesunkenen Fragmente zu bergen und aufzurichten. Die Wiederherstellung der Gelenkfläche gestaltet sich dabei häufig als schwierig. In der vorliegenden Arbeit beschreiben wir eine neuartige operative Technik, in der das eingesunkene Tibiaplateau durch einen perkutan eingebrachten Ballon in Kombination mit einer minimal-invasiven Plattenosteosynthese versorgt wird. Darüber hinaus berichten wir über 5Fälle, welche mit diesem Verfahren bislang behandelt wurde

Percutaneous iliosacral screw fixation in S1 and S2 for posterior pelvic ring injuries: technique and perioperative complications

Objective: Percutaneous iliosacral screw placement allows for minimally invasive fixation of posterior pelvic ring instabilities. The objective of this study was to describe the technique for screws in S1 and S2 using conventional C-arm and to evaluate perioperative complications. Methods: Thirty-eight consecutive patients after percutaneous pelvic ring fixation with cannulated screws in S1 and S2 using conventional C-arm fluoroscopy were analysed. Accuracy of screw placement, nerval lesions, need for second surgery, operation time, and time to full weight bearing were assessed postoperatively and during regular follow-up examinations. Results: Twenty-one patients underwent unilateral screw fixation and 17 patients underwent bilateral screw fixation. In total, 83 screws were placed. Mean age of the patients was 52±19years. Mean operation time was 16±7min/screw. Mean follow-up was 5±3months. Time to full weight bearing in 28 patients was 9±4weeks. Eight patients were still not able to support full weight bearing, partially due to concomitant injuries. Patients without concomitant injuries that affected walking were able to bear full weight after 8±4weeks (n=17). Two patients had persistent postoperative hypaesthesia. No motor weakness was apparent and no postoperative bleeding was observed. Secondary surgery due to screw malpositioning or loosening had to be performed in four patients. The presence of a screw in S2 was not indicated for perioperative complications. Conclusions: Percutaneous iliosacral screw fixation is a rapid and definitive treatment for posterior pelvic ring injuries with a low risk of secondary bleeding during posterior pelvic stabilization. The technique using standard C-arm fluoroscopy was also found to be safe for screws placed in S