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  • 1
    Electronic Resource
    Electronic Resource
    Growth of high quality AlGaAs by metalorganic molecular beam epitaxy using trimethylamine alane (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 2654-2656 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: AlGaAs grown by metalorganic molecular beam epitaxy (MOMBE) has been problematic due to oxygen and carbon contamination, particularly when triethylaluminum (TEAl) has been used as the aluminum source. Consequently, we have investigated trimethylamine alane (TMAAl) as a potential replacement for the conventional metalorganic Al sources. AlGaAs films with excellent structural and optical properties have been grown with this source. Photoluminescence intensities from AlGaAs grown by MOMBE at 500 °C using TMAAl are comparable to those from material grown by metalorganic chemical vapor deposition at 675 °C using triethylaluminum (TMAl). Carbon and oxygen levels in MOMBE-grown AlGaAs are drastically reduced in comparison to similar films grown with TEAl.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102866
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  • 2
    Electronic Resource
    Electronic Resource
    Growth of GaAs and AlGaAs by metalorganic molecular beam epitaxy using tris-dimethylaminoarsenic (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 60 (1992), S. 2421-2423 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Due to the extreme toxicity of AsH3, safer alternatives for III–V epitaxy are highly desirable. In addition, the AsH3 molecule is too stable to decompose on the wafer surface at the temperature and pressure conditions normally used during growth by metalorganic molecular beam epitaxy (MOMBE). This requires the use of high-temperature cracker cells to decompose the AsH3 to elemental As prior to entry to the growth chamber and as a result leads to significant As buildup within the chamber. In this letter we report for the first time MOMBE growth at low temperatures (≤525 °C) using a novel As precursor, tris-dimethylaminoarsenic (DMAAs) without precracking. Specular surface morphologies were obtained over a wide range of growth temperatures, 375–525 °C, for both GaAs and AlGaAs. Carbon concentrations measured by SIMS analysis in GaAs layers deposited from triethylgallium were lower than those obtained using a similar flux of AsH3, while carbon was reduced more than two orders of magnitude in films grown with trimethylgallium and DMAAs as compared to AsH3. No difference in oxygen content was observed between AlGaAs grown with DMAAs and AsH3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.106992
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  • 3
    Electronic Resource
    Electronic Resource
    A 14 cm diameter sliding seal chamber for the Erlangen double scattering spectrometer
    Amsterdam : Elsevier
    Nuclear Instruments and Methods 158 (1979), S. 391-394 
    Details
    ISSN: 0029-554X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0029-554X(79)93825-4
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  • 4
    Electronic Resource
    Electronic Resource
    Investigations of the properties of blockpolymerized and injection-moulded PLLA (1995)
    Springer
    Journal of materials science 6 (1995), S. 68-70 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: The blockpolymerization and injection-moulding procedure are two main techniques used to produce PLLA for medical devices. Until now there has been no comparison of the well known data of blockpolymerized material and data of injection-moulded material. Test rods (2×3×25 mm) were made from block polymerized balls by the injection-moulding procedure. The rods were incubated in tris-buffer-saline for different periods (0, 2, 4, 6, and 8 weeks) at a pH of 7.4 and a temperature of 37°C. The test methods we used were the three-point-bending, the fatigue behaviour and the calculation of the decrease of molecular weight. Both materials under investigation are chemically similar but show very different mechanical properties, in particular the injection moulded material has a very decreased behaviour and a very low loss of molecular weight. Blockpolymerized PLLA rods show a very fast lost bending strength and after 6 weeks a low resistance against cyclic loads in the fatigue behaviour test. Injection moulded PLLA will be used in future for internal fixation of fractures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00120409
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  • 5
    Electronic Resource
    Electronic Resource
    Die retrograde Verriegelungsnagelung distaler Femurfrakturen mit dem GSH-Nagel (1996)
    Springer
    Der Chirurg 67 (1996), S. 1135-1140 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Distal femoral fractures ; Biological osteosynthesis ; Intramedullary supracondylar nail. ; Schlüsselwörter: Supra-/diacondyläre Femurfrakturen ; retrograde Verriegelungsnagelung ; biologische Osteosynthese ; indirekte Repositionstechnik.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Achtzehn Frakturen des distalen Femur wurden zwischen Juni 1993 und September 1995 am „Bergmannsheil“ Bochum mit dem intramedullären supracondylären Nagel (GSH-Nagel) stabilisiert. Es handelte sich um 8 Typ-A-Brüche und 10 Typ-C-Frakturen (AO-Klassifikation). Die operative Technik bestand in einer geschlossenen Reposition und retrograden Nagelimplantation durch die Intercondylarregion in ungebohrter Technik. Der durchschnittliche Nachuntersuchungszeitraum betrug 18,2 Monate (6–32 Monate). Alle Frakturen heilten knöchern vollständig aus. Die durchschnittliche Heilungszeit betrug 12,4 Wochen (8–16 Wochen). Spongiosaplastiken waren nicht notwendig. Sechzehn Patienten erreichten fast das gleiche Bewegungsausmaß im Kniegelenk wie vor dem Unfall. Infektionen oder Pseudarthrosen traten nicht auf. Ein Patient entwickelte eine Varusfehlstellung, die 20 Monate post operationem durch eine supracondyläre Umstellungsosteotomie korrigiert wurde. Der GSH-Nagel ist eine exzellente und biologische Alternative zur herkömmlichen Plattenosteosynthese im Management distaler Femurfrakturen.
    Notes: Summary. Between June 1993 and September 1995, 18 distal femoral fractures were treated using the supracondylar intramedullary nail. There were 8 type A fractures and 10 type C fractures (AO classification). The operative technique involved retrograde insertion of an unreamed supracondylar nail through the intercondylar notch. Follow-up was available on all patients and averaged 18.3 months (range 6–32 months). All fractures healed with an average time to union of 12.4 weeks (range 8–16 weeks). Bone grafting was not necessary in any case. Sixteen patients achieved almost the same ROM as they had had before the injury. One patient developed a varus malignment and underwent correction with a supracondylar osteotomy 20 months post trauma. There were no infections or nonunions. The retrograde supracondylar nail is an excellent alternative to plate osteosynthesis in the management of dia- and supracondylar femoral fractures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001040050115
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  • 6
    Electronic Resource
    Electronic Resource
    Die nichtbakterielle Osteomyelitis der Clavicula (1998)
    Springer
    Der Chirurg 69 (1998), S. 1244-1251 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Clavicle ; Osteomyelitis ; Chronic sclerosing osteomyelitis ; CRMO. ; Schlüsselwörter: Clavicula ; Osteomyelitis ; chronisch-sklerosierende Osteomyelitis ; CRMO.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Neben der bakteriellen exogenen (posttraumatischen/postoperativen) läßt sich die bakterielle endogene (hämatogene) Osteomyelitis und die seltenere Gruppe der abakteriellen, primär chronischen sklerosierenden Osteomyelitiden abgrenzen, die sich im Gegensatz zu den anderen bevorzugt am Schlüsselbein manifestiert. Anhand eines Literaturüberblickes werden Merkmale der verschiedenen Formen unter besonderer Berücksichtigung der chronisch-sklerosierenden Osteomyelitis kritisch analysiert. Aus der Gruppe von 17 Patienten mit Claviculaosteomyelitis, die wir von 1978–1996 behandelt haben, werden 3 Patienten mit primär chronischer sklerosierender Osteomyelitis als Kasuistiken vorgestellt. Differentialdiagnostisch muß die primär chronisch-sklerosierende Osteomyelitis der Clavicula trotz ihres seltenen Auftretens berücksichtigt werden, da sie – nach bioptischer Diagnosesicherung – eine Domäne der konservativen, medikamentösen Therapie ist.
    Notes: Summary. Osteomyelitis can be subdivided into a bacterial exogenic (post-traumatic/postoperative), bacterial endogenic (hematogenous) and an abacterial type, including the rare group containing primary chronic sclerosing osteomyelitis, which is typically localized in the clavicle. In a review of the literature, the criteria for the various types of chronic sclerosing osteomyelitis are analyzed. Out of a group of 17 patients with osteomyelitis of the clavicle treated between 1978 and 1996, three cases of primary chronic sclerosing osteomyelitis are demonstrated. In the differential diagnosis, primary chronic sclerosing osteomyelitis of the clavicle has to be taken into consideration despite its rareness. After establishing a diagnosis by biopsy, in contrast to the other forms, drug therapy will be the treatment of choice and not an operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001040050563
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  • 7
    Electronic Resource
    Electronic Resource
    Präventive Chirurgie am Skelett- und Bewegungsapparat (1999)
    Springer
    Der Chirurg 70 (1999), S. 364-372 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Osteotomy ; Joint instability ; Bone tumors ; Prophylactic surgery. ; Schlüsselwörter: Korrekturosteotomie ; Gelenkinstabilitäten ; präventive Chirurgie ; Knochentumoren.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Präventiv-chirurgische Therapie am Skelett- und Bewegungsapparat betrifft verschiedene Indikationsgebiete, die von präarthrotischen Achsenfehlern über Knochentumoren bis hin zu Gelenkinstabilitäten traumatischer oder habitueller Art oder posttraumatischen Gelenkinkongruenzen reichen. Entscheidend ist die frühzeitige Erkennung von Zuständen, die prospektiv Krankheitswert besitzen, um durch die präventiv-operative Intervention entweder eine präarthrotische Konstellation zu beseitigen oder bei einer bereits vorliegenden Schädigung die Progredienz der Erkrankung zu verzögern, im Idealfall sogar aufzuhalten.
    Notes: Summary. Prophylactic surgery on the musculoskeletal system has a wide range of indications, for example posttraumatic or non-traumatic malalignment of the lower extremities, joint instabilities or bony lesions with the risk of fracture and secondary malignant change. The goals of treatment include pain relief, improved function and redistribution of the physiological mechanical forces. Clinical experience over the past three decades has defined the current role of realignment of the lower limbs. Recent technological advances have further improved the surgical ability to assess and select patients who are candidates for realignment osteotomy or joint stabilization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001040050658
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  • 8
    Electronic Resource
    Electronic Resource
    Möglichkeiten und Grenzen der funktionell konservativen Therapie akuter Achillessehnenrupturen (1997)
    Springer
    Der Chirurg 68 (1997), S. 517-524 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Achilles tendon ; Tendon surgery ; Non-operative treatment ; Early mobilisation ; Ultrasound ; Isokinetic muscle strength. ; Schlüsselwörter: Achillessehne ; Sehnennaht ; konservative Therapie ; Sonographie ; isokinetische Muskelkraftmessung.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. In einem 2,5 jährigen Zeitraum wurden 55 Patienten mit einer frischen Achillessehnenruptur (ASR) nach definierten sonographischen Kriterien operativ und funktionell konservativ behandelt. Durchschnittlich 2,4 Jahre später konnten von 51 Patienten (operative Gruppe = 28 Patienten, konservative Gruppe = 23 Patienten) erneut klinische, funktionelle sowie isokinetische Daten der eingelenkigen Plantarflexoren erfaßt werden. Während in der operativen Gruppe insgesamt bei 10,6 % Wundheilungsstörungen mit spontanem Heilungsverlauf auftraten, betrug die Rerupturrate in der konservativen Gruppe 13 %. Die Incidenz an Achillodynien war zum Nachuntersuchungszeitpunkt in der nicht operativen Gruppe deutlich höher (p = 0,019). Durch die Cybextestung wurden durchschnittliche Kraftdefizite in der operativen Gruppe von 13,7 % und nach funktionell konservativer Behandlung von 24,7 % (p = 0,012) festgestellt. Während die Adaptationsnaht i. d. R. zum Erfolg führt, ist die Indikation zur konservativen Therapie der ASR von der Sehnendiastase, dem Aktivitätswunsch und der Kooperation abhängig.
    Notes: Summary. According to sonographic criteria, 55 patients underwent surgical treatment with mobilisation in a lower leg plaster or conservative treatment with early mobilisation in heel pad (3 cm) shoes when an acute Achilles tendon rupture (ATR) was diagnosed. The follow-up period in 51 patients was 2.4 years (operated group = 28 patients, conservative group = 23 patients) with clinical examination and testing of isokinetic muscle strength in knee joint flexion. After surgical treatment, minor wound infections occurred in 10.6 %. Reruptures occurred in 13 % of the conservative group. Following conservative treatment, the rate of stress-related achillodynia was significantly higher (P = 0.019). In the operated group mean isokinetic muscle strength was 13.7 % lower than in the uninvolved leg and decreased significantly with non-operative treatment to 75.3 % (P = 0.012). We recommend surgical treatment of acute ATR. The indications for conservative treatment depend on the extent of the rupture (measured by ultrasound in the equinus position), the desired level of daily activity and the patient's degree of compliance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001040050223
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  • 9
    Electronic Resource
    Electronic Resource
    Ist die funktionell konservative Behandlung stabiler Außenknöchelfrakturen gerechtfertigt? (1996)
    Springer
    Der Chirurg 67 (1996), S. 1255-1260 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Ankle fractures ; Classification systems ; Functional aftertreatment. ; Schlüsselwörter: Sprunggelenkfrakturen ; Klassifikation ; funktionelle Behandlung.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Für Knöchelbrüche vom Typ Weber B wird bisher eine operative Behandlung empfohlen. Von Dezember 1990 bis Mai 1994 wurden in der Universitätsklinik Bergmannsheil Bochum 85 (58 %) Weber-B-Frakturen konservativ (K-Gruppe) und 61 (42 %) Luxationsbrüche vom B-Typ operativ (OP-Gruppe) behandelt. Das Durchschnittsalter betrug 47,1 (K) und 42,3 Jahre (OP). Die mittlere Beobachtungszeit betrug 17,3 Monate für die klinische und 19,6 Monate für die radiologische Nachuntersuchung. Es gab keine Therapieversager. Basierend auf dem Olerud-Score erreichten Patienten (K) nach funktionell konservativer Behandlung durchschnittlich 95,7 Punkte, nach konservativ immobilisierender Therapie 89,4 Punkte und postoperativ (OP) mit funktioneller Nachbehandlung 92,4 Punkte sowie mit mehrwöchiger Gipsruhigstellung 85,0 Punkte. Arthrogene Begleitverletzungen und eine mehrwöchige Immobilisation korrelierten mit einem geringeren funktionellen Endresultat. In Übereinstimmung mit Langzeitergebnissen der Literatur wird der eigene Algorithmus zur funktionell konservativen Behandlung von Außenknöchelfrakturen bestätigt.
    Notes: Summary. For Weber type B ankle fractures, operative treatment is generally recommended. Yet, there is no general agreement about the role of functional treatment. In a prospective follow-up study from December 1990 to May 1994, 146 patients were reviewed. The mean follow-up time was 17.3 months for clinical examinations and 19.6 months for X-rays. There were no failures. In all, 85 patients (58 %) were treated conservatively (group K). A below-the-knee plaster was applied to 23 patients for 6 weeks, and 62 patients had functional treatment with an ankle brace. According to the Olerud Score, the first subgroup (K-plaster) achieved 89.4 points and the last (K-func.) reached 95.7 points. There were no signs of post-traumatic arthritis. 61 patients (42 %) had open reduction and internal osteosynthesis (group OP). In 19 patients a plaster immobilization was necessary, and in 42 patients early mobilization was possible. The first subgroup (OP-plaster) achieved 85.0 points in the Olerud Score; the last (OP-func.) achieved 92.4 points. According to the degree of instability following ankle injuries, a new algorithm for treatment of type B ankle fractures is described, emphasizing early mobilization and functional aftertreatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001040050135
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  • 10
    Electronic Resource
    Electronic Resource
    Monocondyläre Frakturen des Femur Therapeutische Strategie und klinische Ergebnisse (1997)
    Springer
    Der Chirurg 68 (1997), S. 72-76 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Unicondylar femoral fractures ; Screw stabilization ; Neer score ; Concomitant injuries. ; Schlüsselwörter: Monocondyläre Femurfrakturen ; Zugschraubenosteosynthese ; Neer-Score.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. 29 Patienten mit moncondylären Frakturen des distalen Femurs wurden zwischen 1981 und 1994 im Bergmannsheil Bochum behandelt. Alle Patienten erlitten ihre Verletzungen von direktem Trauma. Es handelte sich um 16 laterale Condylenfrakturen, 7 mediale Condylenfrakturen und in 6 Fällen waren tangenitale Rollenabbrüche (Hoffa-Frakturen) vorhanden. 28 Frakturen waren geschlossen, und eine Fraktur war drittgradig offen. Elf Patienten erlitten Begleitverletzungen des musculoskelettären Systems. Alle Frakturen wurden mit offener anatomischer Reposition und stabiler interner Fixation mit Spongiosazugschrauben behandelt. Die postoperative Behandlung beinhaltete frühe passive Bewegung auf der Elektroschiene und Fußsohlenkontaktbelastung für 6–8 Wochen. Der durchschnittliche Nachuntersuchungszeitraum betrug 68 Monate. Die Behandlungsergebnisse wurden nach dem Neer-Score bewertet. 27 von 29 Patienten konnten nachuntersucht werden. 23 Patienten hatten ein exzellentes Resultat, 3 Patienten ein befriedigendes Resultat, 1 Patient hatte ein unbefriedigendes Resultat. Alle Patienten ohne exzellentes Resultat hatten Begleitverletzungen. Die offene anatomische Reposition und interne Schraubenfixation bei monocondylären Femurfrakturen sorgt bei Monoverletzungen für hervorragende Langzeitresultate.
    Notes: Summary. Twenty-nine unicondylar fractures of the distal femur were treated at the Trauma Center “Bergmannsheil”, University of Bochum, Germany, between 1981 and 1994. All patients sustained their injuries from severe direct trauma. There were 16 lateral condylar fractures, 7 medial condylar fractures and 6 tangential posterior (“Hoffa-type”) fractures. Twenty-eight closed injuries and 1 grade IIIB open fracture were included. Eleven patients sustained concomitant injuries to the skeleton. All fractures were treated with open reduction and internal fixation with screws within 8 h of admission. Postoperative management consisted of early continuous passive motion and minimal weight-bearing for 6–8 weeks, progressing to full weight-bearing. The mean follow-up was 68 months (18–120). The therapeutic outcome (clinical result, radiographs) was rated by the Neer score. Twenty-seven patients were available for follow-up examination. Of these, 23 were rated as excellent. 3 achieved satisfactory results, and 1 had an unsatisfactory result. All patients who did not achieve an excellent outcome had had accompanying injuries. Open reduction and internal screw fixation of unicondylar femur fractures provided overall excellent long-term results. The therapeutic outcome was significantly affected by associated injuries of the skeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001040050153
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