Si(lOO) samples have been implanted with low does (10 7 -10 9 cm -2 ) of MeV 76 Ge and ,20 Sn ions. Deep level transient spectroscopy was used for sample analysis, and the generation of vacancy-related point defects is found to increase with increasing implantation temperature and to decrease with increasing ion dose rate. These results are in direct contrast to that for damage buildup at high doses (> 10 12 cm ~2), and the effect is attributed to rapidly diffusing Si self-interstitials which overlap and annihilate vacancies created in adjacent ion tracks.PACS numbers: 61.72. Bb, 61.72.Tt, 61.80.Jh, 71.55.Ht Implantation of energetic ions into crystalline semiconductors gives rise to atomic displacements and structural defects. The generation of stable defects depends on several parameters, e.g., ion energy, ion mass, sample temperature, ion dose, and dose rate. A process of crucial importance for damage buildup in semiconductors is defect annealing during implantation [1][2][3][4]. Usually, one distinguishes between two types of annealing processes during ion implantation [5]: (i) thermal or bulk annealing and (ii) dynamic annealing. Type (i) resembles ordinary thermal annealing and is caused by a rise in target temperature during high dose rate ion bombardment. In the following, we will concentrate on type (ii), and in particular, its dependence on dose rate and sample temperature.For doses above ~10 12 cm -2 and dose rates in the range of ~10 n to 10 15 cm~2s _i it is well established that the influence of dynamic annealing in semiconductors decreases with increasing dose rate and decreasing target temperature [1-6]. Alternative explanations exist for these effects [5,6] and one among others is that at sufficiently high dose rates, collision cascades can overlap before the single cascade defects have completed their annealing process [5]. As a result, a higher concentration of defects which are more stable at (and above) room temperature (RT) is formed. At low enough target temperatures the mobility of migrating defects responsible for the annealing process decreases, and the ion-induced damage is to a large extent "frozen in" [4]. Again, a high concentration of stable defects is generated in the single cascades as dynamic annealing diminishes.Recently, Hallen et al. [7] irradiated silicon at RT with 1.3 MeV protons using a dose of only 5xl0 9 cm -2 and dose rates of 10 7 to 10 10 cm~2s _1 . In direct contrast to the results for heavier ions and higher doses and dose rates, they found a reverse dose rate dependence; i.e., for a constant dose the resulting defect density decreased with increasing dose rate.In this work silicon samples have been implanted with low doses of MeV 76 Ge and 12° Sn ions using different dose rates and sample temperatures. To the best of our knowledge, we have observed for the first time a "reverse" temperature and dose rate dependence for point defect production by heavy ions in silicon. Indeed, the generation rate of divacancy centers (V2) is reduced by a factor of -2 as the impla...

This study revealed that preoperative physiologic passive knee HE ≥5° is present in one-third of patients who undergo revision ACLR. HE ≥5° was an independent significant predictor of graft failure after revision ACLR with a >2-fold OR of subsequent graft rupture in revision ACL surgery. Registration: NCT00625885 ( ClinicalTrials.gov identifier).

Some aspects of sampling family data in human genetics are discussed. Two well-investigated ascertainment models, the complete ascertainment model and the single ascertainment model, which have been derived using restrictive sampling assumptions, are shown to hold under four more general sets of assumptions.

It is generally accepted that the presence of thoracic skeletal injuries has a predictive value for acute traumatic aortic tear (ATAT). The purpose of this study is to objectively assess the validity of that premise. The initial chest radiographs of 548 patients who underwent aortic angiography for suspected ATAT were reviewed for thoracic skeletal injuries. The incidence of thoracic skeletal injuries was compared between patients with and without angiographically confirmed ATAT. Rib fracture is the only thoracic skeletal injury whose incidence is statistically significantly higher in patients with ATAT (36 of 62, 58.1%) than in those without (207 of 486, 42.6%) (p = 0.0209). The positive predictive value of rib fractures in evaluating ATAT, however, is 14.8%, a rate similar to the incidence of ATAT at most trauma centers, and the specificity is 57.4%. The second most common finding in patients with ATAT, the absence of thoracic skeletal injury, is not statistically significantly different between patients with ATAT (24 of 62, 38.7%) and those without (220 of 486, 45.3%) (p = 0.3279). We conclude that (1) there is no clinically relevant correlation between thoracic skeletal injuries and ATAT, and (2) selection of patients requiring thoracic aortography must be based on appropriate mechanism of injury and radiographic evidence of mediastinal hematoma.

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