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Venous disorders as an occupational disease - a systematic review on epidemiology, pathophysiology, and modification strategies. VASA 2024; 53:172-184. [PMID: 38536202 DOI: 10.1024/0301-1526/a001116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Forced postures are common in the workplace. Work in the primary economic sector is characterised by a high degree of physical activity and movement; however, activities in the secondary and tertiary sectors commonly require workers to stand or sit. An expansion of the tertiary sector in recent decades has meant that people in industrialised and emerging economies primarily sit or stand at work. The aim of the systematic review was to identify occupational factors relating to the presence of chronic venous disease (CVD), to place these in the context of developments in the workplace, and to determine whether measures are in place to prevent CVD. We performed a systematic literature review to analyse studies assessing work-related risk factors for CVD. We searched for publications in the PubMed database, the clinic library of BG Hospital Bergmannstrost Halle, and the registry of the German Statutory Accident Insurance. Using occupation-specific keyword combinations, we identified 27,522 publications. The publications underwent an automatic and manual filtering process according to the PRISMA guidelines and 81 publications qualified for the review. Ultimately 25 studies were included in the systematic review. All of the subjects of the studies worked in the secondary and tertiary sectors. No studies looked at the relationship between venous disorders and primary sector occupations. Standing at work for more than four hours a day, repeated heavy lifting, and cumulative time working in a sitting or standing position are risk factors for the development of CVD. Sitting is less of a risk factor than standing or walking. Occupational history and the patient's activity profile are important diagnostic tools which can help confirm a diagnosis and justify treatment when findings are inconsistent. Compression therapy is the primary form of secondary and tertiary prevention. There continues to be a lack of primary preventive measures related to workplace design.
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[The crucial role of color-coded duplex sonography before planning microvascular tissue transfer in the lower extremities]. Unfallchirurg 2022; 125:422-424. [PMID: 35312795 DOI: 10.1007/s00113-022-01164-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2022] [Indexed: 12/24/2022]
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Abstract
Objective: The main risk factors for cardiac events, and particularly for the development of atherosclerosis, are diabetes mellitus, arterial hypertension, dyslipidemia and smoking. Patients with a traumatic spinal cord injury (SCI) may present with autonomic nervous system dysfunction depending on their level of spinal cord injury. Studies have found a rise in cardiovascular mortality. A systematic review was conducted that focused on this patient group's predisposition to vascular risk. Methods: We performed a PubMed and Cochrane database search. After applying specific search criteria, 42 articles were included in our analysis out of a total of 10,784 matches. The articles were selected with the aim of establishing cardiovascular risk factors in patients with traumatic spinal cord injury. Results: Patients with SCI are at an increased risk for peripheral artery disease even in the absence of cardiovascular risk factors. Major vascular changes to the arteries of patients with SCI include: a reduction in lumen size, increased vessel wall tension, higher vascular stiffness, an impaired reactive hyperemic response, and a lack of reduced vascular resistance. The findings for carotid atherosclerosis were inconclusive. This group of patients also has a higher disposition for diabetes mellitus, lipid metabolism disorders and coronary artery disease. Paraplegics are more likely to suffer from dyslipidemia, obesity and PAD, while tetraplegics are more likely to have diabetes mellitus. Conclusions: Patients with SCI are more likely to have cardiovascular risk factors and have cardiovascular disease compared to the normal population. Peripheral circulatory disorders are particularly common. Patients with SCI are now considered to be a new risk group for cardiovascular disease; however, large epidemiological studies are needed to verify in more detail the cardiovascular risk profile of this patient group.
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Organische und funktionelle Durchblutungsstörungen der Hand – differenzialdiagnostische Aspekte. PHLEBOLOGIE 2020. [DOI: 10.1055/a-1170-9250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
ZusammenfassungDie Abklärung von venösen und arteriellen Durchblutungsstörungen sowie Lymphödemen gehört zur täglichen Praxisroutine des Gefäßmediziners. Nicht selten werden von chirurgischen Kollegen Patienten mit Beschwerden im Schulter-, Arm- und Handbereich zum Ausschluss einer vaskulären Ursache vorgestellt. Der wohl häufigste Abklärungsgrund im Handbereich ist das Raynaud-Phänomen. Neben arteriosklerotischen Durchblutungsstörungen und der Thrombangiitis obliterans sind das Hypothenar-/Thenar-Hammer-Syndrom und das Vibrationssyndrom in den Fingern eher wenig bekannte Entitäten, deren Kenntnis jedoch neben dem medizinischen Vorgehen auch versicherungsrelevante Konsequenzen haben kann. Während beim Hypothenar-/Thenar-Hammer-Syndrom eine organische Durchblutungsstörung vorliegt, beinhaltet das Vibrationssyndrom der Finger eine funktionell vaskuläre sowie eine nervale Komponente, die eine Trennung vom Karpaltunnelsyndrom erschwert. Bei beiden Entitäten ist eine Berufsanamnese häufig hilfreich. Schon der Verdacht auf eine Berufskrankheit muss nach Gesetzeslage zur Anzeige gebracht werden. Der Artikel beschreibt die wesentlichen pathophysiologischen Mechanismen beider Entitäten und stellt diagnostische und therapeutische Optionen dar. Die Kenntnis beider Erkrankungen erweitert die differenzialdiagnostische Vorgehensweise in der täglichen Praxisroutine bei Patienten mit Schulter-Arm-Hand-Beschwerden und bei Patienten mit Raynaud-Phänomen.
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Direct Structural Identification and Quantification of the Split-Vacancy Configuration for Implanted Sn in Diamond. PHYSICAL REVIEW LETTERS 2020; 125:045301. [PMID: 32794782 DOI: 10.1103/physrevlett.125.045301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 05/28/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate formation of the ideal split-vacancy configuration of the Sn-vacancy center upon implantation into natural diamond. Using β^{-} emission channeling following low fluence ^{121}Sn implantation (2×10^{12} atoms/cm^{2}, 60 keV) at the ISOLDE facility at CERN, we directly identified and quantified the atomic configurations of the Sn-related centers. Our data show that the split-vacancy configuration is formed immediately upon implantation with a surprisingly high efficiency of ≈40%. Upon thermal annealing at 920 °C ≈30% of Sn is found in the ideal bond-center position. Photoluminescence revealed the characteristic SnV^{-} line at 621 nm, with an extraordinarily narrow ensemble linewidth (2.3 nm) of near-perfect Lorentzian shape. These findings further establish the SnV^{-} center as a promising candidate for single photon emission applications, since, in addition to exceptional optical properties, it also shows a remarkably simple structural formation mechanism.
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The importance of antiphospholipid syndrome testing in venous thromboembolism after varicose vein surgery. J Vasc Surg Venous Lymphat Disord 2020; 8:1097-1101. [PMID: 32381473 DOI: 10.1016/j.jvsv.2020.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/13/2020] [Indexed: 10/24/2022]
Abstract
Anticoagulation treatment after a venous thromboembolism event is usually managed on a case-by-case basis. The risk of thrombosis must be weighed against the risk of bleeding. Identifying patients who could benefit from anticoagulation therapy requires the thromboembolism event to be assessed with respect to its presentation and the severity of the triggering factors. A case report is employed to explain the important aspects of practical approaches to venous thromboembolism events after vein surgery. The Trial on Rivaroxaban in AntiPhospholipid Syndrome (TRAPS) study has prompted new considerations for anticoagulation management. Patients with antiphospholipid syndrome need to be identified early to lower the risk of thromboembolism also during anticoagulation treatment.
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[Persistent Diarrhea of an Elderly Lady - How to Combine Blood Pressure and Diarrhea]. Dtsch Med Wochenschr 2019; 144:394-397. [PMID: 30870870 DOI: 10.1055/a-0830-6521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
HISTORY AND CLINICAL FINDINGS A 72-year-old female presented with a therapy-resistant diarrhea. EXAMINATIONS In the case of negative stool cultures and inconspicuous radiological imaging, further endoscopic diagnostics were performed. Histological implicated the image of a celiac disease in the duodenum and lymphocytic colitis reaching into the terminal ileum. In the case of negative antibody detection for celiac disease, a medication side effect was considered by differential diagnosis. TREATMENT When olmesartan was discontinued, she developed a rapid improvement of the symptoms. CONCLUSION AND DIAGNOSIS For the angiotensin receptor antagonist olmesartan, the occurrence of a sprue-like enteropathy has rarely described. Microscopic colitis is an exception.
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[Finger amputation following a minor injury: insurance aspects in Germany and practical approaches]. HANDCHIR MIKROCHIR P 2019; 51:54-61. [PMID: 30836420 DOI: 10.1055/a-0826-4669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Expert medical assessments are an integral part of a physician's sphere of activity today. Since subspecialisation is constantly advancing, there is often a limited pool of medical experts available for specific assessment matters. Medical experts have to assess the full proof of facts and the probability of correlations. As regards assessments issued to the statutory accident insurance, the issue of possible pre-existing conditions/damage plays an important role in the discussion surrounding the grounds for liability. Occasional causes or minor injuries are relevant for insurance claims and must be recognised.An insured person with an acral, non-arteriosclerotic circulatory disorder (thrombangiitis obliterans) was involved in an accident at work that resulted in a soft tissue skin defect and the need to amputate the finger. A vascular medical examination found that there was no occasional cause. A hand surgery expert proposed a 25 percent reduction in earning capacity. The accident insurance company followed the decision of the medical experts.
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Abstract
Hypothenar or thenar hammer syndrome (HHS) and hand-arm vibration syndrome (HAVS) are diseases caused by acute or chronic trauma to the upper extremities. Since both diseases are generally related to occupation and are recognised as occupational diseases in most countries, vascular physicians need to be able to distinguish between the two entities and differentiate them from other diagnoses. A total of 867 articles were identified as part of an Internet search on PubMed and in non-listed occupational journals. For the analysis we included 119 entries on HHS as well as 101 papers on HAVS. A professional history and a job analysis were key components when surveying the patient's medical history. The Doppler-Allen test, duplex sonography and optical acral pulse oscillometry were suitable for finding an objective basis for the clinical tests. In the case of HHS, digital subtraction angiography was used to confirm the diagnosis and plan treatment. Radiological tomographic techniques provided very limited information distal to the wrist. The vascular component of HAVS proved to be strongly dependent on temperature and had to be differentiated from the various other causes of secondary Raynaud's phenomenon. The disease was medicated with anticoagulants and vasoactive substances. If these were not effective, a bypass was performed in addition to various endovascular interventions, especially in the case of HHS. Despite the relatively large number of people exposed, trauma-induced circulatory disorders of the hands can be observed in a comparatively small number of cases. For the diagnosis of HHS, the morphological detection of vascular lesions through imaging is essential since the disorder can be accompanied by critical limb ischaemia, which may require bypass surgery. In the case of HAVS, vascular and sensoneurological pathologies must be objectified through provocation tests. The main therapeutic approach to HAVS is preventing exposure.
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Abstract
Damage to the hand caused by vibration has been observed with a range of trades and professions and in connection with various types of sport. Osseous, neurogenic and vascular lesions can lead to chronic ailments and permanent functional impairment. Hand-arm vibration syndrome (HAVS) and hypothenar/thenar hammer syndrome (HHS, THS) are interesting for vascular medicine. From a surgical perspective, there is a special significance in the fact that both syndromes are recognised occupational diseases (BK 2104 and BK 2114) which have to be acknowledged by an accident insurance doctor and in the medical report. Hypothenar/thenar hammer syndrome is caused by repeated force exerted in the region of the small finger or the ball of the thumb and is characterised by a trauma-induced lesion of the ulnar artery or radial artery that can lead to pain due to ischaemia in the acral area supplying blood to the arteries of the affected hand, usually the dominant hand. It is considered to be hand-arm vibration syndrome when there is a heightened sensitivity to coldness with vasospastic circulatory disturbance. The paper presents various clinical and functional diagnostic tests to enable a diagnosis. Doppler and duplex ultrasound exploration play an important role. Various radiological methods can augment diagnostic testing. The symptoms can be treated using medication or physiotherapy to improve perfusion by stimulating vasodilatation. An effective causal therapy is currently not available. Thus, when drawing up the medical report, particular attention should be paid to gathering information about the patient's medical history so that an unequivocal link can be made between the cause of the damage and the physical damage, as this could have sociomedical and pension-relevant consequences for the patient.
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Lattice Location of Mg in GaN: A Fresh Look at Doping Limitations. PHYSICAL REVIEW LETTERS 2017; 118:095501. [PMID: 28306281 DOI: 10.1103/physrevlett.118.095501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 06/06/2023]
Abstract
Radioactive ^{27}Mg (t_{1/2}=9.5 min) was implanted into GaN of different doping types at CERN's ISOLDE facility and its lattice site determined via β^{-} emission channeling. Following implantations between room temperature and 800 °C, the majority of ^{27}Mg occupies the substitutional Ga sites; however, below 350 °C significant fractions were also found on interstitial positions ∼0.6 Å from ideal octahedral sites. The interstitial fraction of Mg was correlated with the GaN doping character, being highest (up to 31%) in samples doped p type with 2×10^{19} cm^{-3} stable Mg during epilayer growth, and lowest in Si-doped n-GaN, thus giving direct evidence for the amphoteric character of Mg. Implanting above 350 °C converts interstitial ^{27}Mg to substitutional Ga sites, which allows estimating the activation energy for migration of interstitial Mg as between 1.3 and 2.0 eV.
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Paramagnetism and antiferromagnetic interactions in single-phase Fe-implanted ZnO. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:416001. [PMID: 24025311 DOI: 10.1088/0953-8984/25/41/416001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
As the intrinsic origin of the high-temperature ferromagnetism often observed in wide-gap dilute magnetic semiconductors becomes increasingly debated, there is a growing need for comprehensive studies on the single-phase region of the phase diagram of these materials. Here we report on the magnetic and structural properties of Fe-doped ZnO prepared by ion implantation of ZnO single crystals. A detailed structural characterization shows that the Fe impurities substitute for Zn in ZnO in a wurtzite Zn(1-x)Fe(x)O phase which is coherent with the ZnO host. In addition, the density of beam-induced defects is progressively decreased by thermal annealing up to 900 ° C, from highly disordered after implantation to highly crystalline upon subsequent annealing. Based on a detailed analysis of the magnetometry data, we demonstrate that isolated Fe impurities occupying Zn-substitutional sites behave as localized paramagnetic moments down to 2 K, irrespective of the Fe concentration and the density of beam-induced defects. With increasing local concentration of Zn-substitutional Fe, strong nearest-cation-neighbor antiferromagnetic interactions favor the antiparallel alignment of the Fe moments.
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A versatile apparatus for on-line emission channeling experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:073506. [PMID: 23902062 DOI: 10.1063/1.4813266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The concept and functionality of an apparatus dedicated to emission channeling experiments using short-lived isotopes on-line at ISOLDE∕CERN is described. The setup is assembled in two functional blocks - (a) base stand including beam collimation, implantation and measurement chamber, cryogenic extension, and vacuum control system and (b) Panmure goniometer extension including maneuvering cradle and sample heating furnace. This setup allows for in situ implantation and sample analysis in the as-implanted state and upon cooling down to 50 K and during annealing up to 1200 K. The functionality of the setup will be illustrated with the example of establishing the lattice location of (56)Mn probes implanted into GaAs.
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Abstract
Abstract
In this paper we review materials characterization techniques using radioactive isotopes at the ISOLDE/CERN facility. At ISOLDE intense beams of chemically clean radioactive isotopes are provided by selective ion-sources and high-resolution isotope separators, which are coupled on-line with particle accelerators. There, new experiments are performed by an increasing number of materials researchers, which use nuclear spectroscopic techniques such as Mössbauer, perturbed angular correlations (PAC), β-NMR and emission channeling with short-lived isotopes not available elsewhere. Additionally, diffusion studies and traditionally non-radioactive techniques as deep level transient spectroscopy, Hall effect and photoluminescence measurements are performed on radioactive doped samples, providing in this way the element signature upon correlation of the time dependence of the signal with the isotope transmutation half-life. Current developments, applications and perspectives of using radioactive ion beams and techniques in solid state and biophysics research are presented with a few examples.
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Transition metal impurities on the bond-centered site in germanium. PHYSICAL REVIEW LETTERS 2009; 102:065502. [PMID: 19257601 DOI: 10.1103/physrevlett.102.065502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Indexed: 05/27/2023]
Abstract
We report on the lattice location of ion implanted Fe, Cu, and Ag impurities in germanium from a combined approach of emission channeling experiments and ab initio total energy calculations. Following common expectation, a fraction of these transition metals (TMs) was found on the substitutional Ge position. Less expected is the observation of a second fraction on the sixfold coordinated bond-centered site. Ab initio calculated heats of formation suggest this is the result of the trapping of a vacancy by a substitutional TM impurity, spontaneously forming an impurity-vacancy complex in the split-vacancy configuration. We also present an approach to displace the TM impurities from the electrically active substitutional site to the bond-centered site.
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Die Umsetzung der neuen Musterweiterbildungsordnung und die europarechtlichen Implikationen. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2006; 49:358-63. [PMID: 16523322 DOI: 10.1007/s00103-006-1241-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Specialized medical training serves to deepen the abilities and talents acquired during medical training. It usually takes place during professional activity under the guidance of experienced physicians authorized for specialized training and ends after a successfully completed examination with the acquisition of a specialized training title. The structural requirements, which are to be taught in the context of the specialized medical training, are specified in a statute (Weiterbildungsordnung), which was adopted by the chamber of physicians. The model Weiterbildungsordnung, decided upon by the German medical assembly (Deutscher Arztetag), serves as a recommendation in the individual States in Germany to achieve statutes as uniform as possible. The regional law bases and the implementation of the Weiterbildungsordnung in the Heilberufe-Kammergesetz are described by the example of the State of Baden-Württemberg. The extensive effects of the European law are illustrated by the example of the general practitioner (Arzt für Allgemeinmedizin).
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Direct evidence for As as a Zn-site impurity in ZnO. PHYSICAL REVIEW LETTERS 2005; 95:215503. [PMID: 16384155 DOI: 10.1103/physrevlett.95.215503] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Indexed: 05/05/2023]
Abstract
Arsenic has been reported in the literature as one of the few p-type dopants in the technologically promising II-VI semiconductor ZnO. However, there is an ongoing debate whether the p-type character is due to As simply replacing O atoms or to the formation of more complicated defect complexes, possibly involving As on Zn sites. We have determined the lattice location of implanted As in ZnO by means of conversion-electron emission channeling from radioactive (73)As. In contrast to what one might expect from its nature as a group V element, we find that As does not occupy substitutional O sites but in its large majority substitutional Zn sites. Arsenic in ZnO (and probably also in GaN) is thus an interesting example for an impurity in a semiconductor where the major impurity lattice site is determined by atomic size and electronegativity rather than its position in the periodic system.
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Lattice Location of Implanted
147
Nd and
147*
Pm in GaN Using Emission Channeling. ACTA ACUST UNITED AC 2002. [DOI: 10.1002/pssc.200390086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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[Successful cardiopulmonary resuscitation with a high-dosage bolus injection of rt-PA after fulminant pulmonary embolism]. Anasthesiol Intensivmed Notfallmed Schmerzther 2001; 36:306-8. [PMID: 11413703 DOI: 10.1055/s-2001-14453] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The fulminant pulmonary embolism is one of the most feared complications of hospitalized patients. A high percentage of those patients need resuscitation within a short period of time. In such cases, the thrombolysis is a quickly attained therapeutical alternative to pulmonary embolectomy. A 77-year-old man with a surgically managed femoral fracture who suffered a massive pulmonary embolism, had to be resuscitated on the 11th postoperative day. Because of the fast confirmation of the diagnosis with the ECG and transthoracical echocardiography, it was possible to initiate thrombolysis with a bolus of 100 mg rt-PA immediately after the beginning of cardiac arrest and resuscitation. After 20 min of cardiopulmonary resuscitation (CPR), the patient could be stabilized under high dosage of catecholamines. The patient survived after prolonged intensive care treatment without severe bleeding complications, neither did he present any neurological deficit. We conclude that in the case of massive pulmonary embolism with small chance of resuscitation, the high-dose bolus injection of rt-PA could enrich the therapeutical possibilities.
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Lattice location and stability of ion implanted Cu in Si. PHYSICAL REVIEW LETTERS 2000; 84:1495-1498. [PMID: 11017551 DOI: 10.1103/physrevlett.84.1495] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/1999] [Indexed: 05/23/2023]
Abstract
We report on the lattice location of ion implanted Cu in Si using the emission channeling technique. The angular distribution of beta(-) particles emitted by the radioactive isotope 67Cu was monitored following room temperature implantation into Si single crystals and annealing up to 600 degrees C. The majority of Cu was found close to substitutional sites, however, with a significant displacement, most likely 0.50(8) A along the <111> directions towards the bond center position. The activation energy for the dissociation of near-substitutional Cu is estimated to be 1.8-2.2 eV.
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Host-odour recognition in two tick species is coded in a blend of vertebrate volatiles. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 1999; 185:59-67. [PMID: 10450611 DOI: 10.1007/s003590050366] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The questing behaviour of ixodid ticks serves for identification and localisation of approaching hosts and is evoked by carbon dioxide, vibrations, visual and odour stimuli. In an olfactometer, we examined the specificity of the questing response of larvae of Boophilus microplus, a one-host tick which develops mainly on cattle, and Ixodes ricinus, a three-host tick with a broader host spectrum. While all mammalian odours tested were equally stimulatory for I. ricinus, B. microplus was clearly more activated by bovine odours. A phenolic fraction of bovine odour stimulated B. microplus only. Attractive components of the host odours were identified by exposing the ticks to single chemicals and mixtures. Single chemicals stimulated questing responses only at levels higher than the levels detected in the bovine odour. However, an artificial odour blend of 37 pure chemicals, diluted to concentrations at which the individual components were inactive, proved to be as effective as natural host odour for both tick species. Further fractionation of the blend revealed that the combinatory effect was achieved by only 7 compounds in both species. Although B. microplus responded to the same synergistic mixture of volatiles as I. ricinus, it showed significant higher sensitivity to the cattle-associated compounds 1-octen-3-ol and 2-nitrophenol and this might contribute to its host-specificity.
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Impurity lattice location and recovery of structural defects in semiconductors studied by emission channeling. ACTA ACUST UNITED AC 1994. [DOI: 10.1007/bf02060641] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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