172 research outputs found
Point defects in silicon after zinc diffusion - a deep level transient spectroscopy and spreading-resistance profiling study
We present results from spreading-resistance profiling and deep level transient spectroscopy on Si after Zn diffusion at 1294 K. Concentration profiles of substitutional in dislocation-free and highly dislocated Si are described by a diffusion mechanism involving interstitial-substitutional exchange. Additional annealing at 873 K following quenching from the diffusion temperature is required in the case of dislocation-free Si to electrically activate . The formation of complexes of with unwanted impurities upon quenching is discussed. Additional Ni diffusion experiments as well as total energy calculations suggest that Ni is a likely candidate for the passivation of Zns. From total energy calculations we find that the formation of complexes involving Zn and Ni depends on the position of the Fermi level. This explains differences in results from spreading-resistance profiling and deep level transient spectroscopy on near-intrinsic and p-type Si, respectively
Predicting live birth, preterm and low birth weight infant after in-vitro fertilisation: a prospective study of 144018 treatment cycles
Background
The extent to which baseline couple characteristics affect the probability of live birth and adverse perinatal outcomes after assisted conception is unknown.
Methods and Findings
We utilised the Human Fertilisation and Embryology Authority database to examine the predictors of live birth in all in vitro fertilisation (IVF) cycles undertaken in the UK between 2003 and 2007 (n = 144,018). We examined the potential clinical utility of a validated model that pre-dated the introduction of intracytoplasmic sperm injection (ICSI) as compared to a novel model. For those treatment cycles that resulted in a live singleton birth (n = 24,226), we determined the associates of potential risk factors with preterm birth, low birth weight, and macrosomia. The overall rate of at least one live birth was 23.4 per 100 cycles (95% confidence interval [CI] 23.2â23.7). In multivariable models the odds of at least one live birth decreased with increasing maternal age, increasing duration of infertility, a greater number of previously unsuccessful IVF treatments, use of own oocytes, necessity for a second or third treatment cycle, or if it was not unexplained infertility. The association of own versus donor oocyte with reduced odds of live birth strengthened with increasing age of the mother. A previous IVF live birth increased the odds of future success (OR 1.58, 95% CI 1.46â1.71) more than that of a previous spontaneous live birth (OR 1.19, 95% CI 0.99â1.24); p-value for difference in estimate <0.001. Use of ICSI increased the odds of live birth, and male causes of infertility were associated with reduced odds of live birth only in couples who had not received ICSI. Prediction of live birth was feasible with moderate discrimination and excellent calibration; calibration was markedly improved in the novel compared to the established model. Preterm birth and low birth weight were increased if oocyte donation was required and ICSI was not used. Risk of macrosomia increased with advancing maternal age and a history of previous live births. Infertility due to cervical problems was associated with increased odds of all three outcomesâpreterm birth, low birth weight, and macrosomia.
Conclusions
Pending external validation, our results show that couple- and treatment-specific factors can be used to provide infertile couples with an accurate assessment of whether they have low or high risk of a successful outcome following IVF
Factors associated with failed treatment : an analysis of 121,744 women embarking on their first IVF cycles
Peer reviewedPublisher PD
Influence of severity and level of injury on the occurrence of complications during the subacute and chronic stage of traumatic spinal cord injury:a systematic review
Objective: Secondary health conditions (SHCs) are long-term complications that frequently occur due to traumatic spinal cord injury (tSCI) and can negatively affect quality of life in this patient population. This study provides an overview of the associations between the severity and level of injury and the occurrence of SHCs in tSCI. Methods: A systematic search was conducted in PubMed and Embase that retrieved 44 studies on the influence of severity and/or level of injury on the occurrence of SHCs in the subacute and chronic phase of tSCI (from 3 months after trauma). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Results: In the majority of studies, patients with motor-complete tSCI (American Spinal Injury Association [ASIA] Impairment Scale [AIS] grade A or B) had a significantly increased occurrence of SHCs in comparison to patients with motor-incomplete tSCI (AIS grade C or D), such as respiratory and urogenital complications, musculoskeletal disorders, pressure ulcers, and autonomic dysreflexia. In contrast, an increased prevalence of pain was seen in patients with motor-incomplete injuries. In addition, higher rates of pulmonary infections, spasticity, and autonomic dysreflexia were observed in patients with tetraplegia. Patients with paraplegia more commonly suffered from hypertension, venous thromboembolism, and pain. Conclusions: This review suggests that patients with a motor-complete tSCI have an increased risk of developing SHCs during the subacute and chronic stage of tSCI in comparison with patients with motor-incomplete tSCI. Future studies should examine whether systematic monitoring during rehabilitation and the subacute and chronic phase in patients with motor-complete tSCI could lead to early detection and potential prevention of SHCs in this population
Strategies to suppress A-center formation in silicon and germanium from a mass action analysis viewpoint
Point defects in silicon after zinc diffusion - a deep level transient spectroscopy and spreading-resistance profiling study
YangZheng XiaoJi exerts anti-tumour growth effects by antagonising the effects of HGF and its receptor, cMET, in human lung cancer cells
BACKGROUND: Hepatocyte growth factor (HGF) is a cytokine that has a profound effect on cancer cells by stimulating migration and invasion and acting as an angiogenic factor. In lung cancer, the factor also plays a pivotal role and is linked to a poor outcome in patients. In particular, HGF is known to work in combination with EGF on lung cancer cells. In the present study, we investigated the effect of a traditional Chinese medicine reported in cancer therapies, namely YangZheng XiaoJi (YZXJ) on lung cancer and on HGF mediated migration and invasion of lung cancer cells. METHODS: Human lung cancer cells, SKMES1 and A549 were used in the study. An extract from the medicine was used. Cell migration was investigated using the EVOS and by ECIS. Cellâmatrix adhesion and in vitro invasion were assessed. In vivo growth of lung cancer was tested using an in vivo xenograft tumour model and activation of the HGF receptor in lung tumours by an immunofluorescence method. RESULTS: Both lung cancer cells increased their migration in response to HGF and responded to YZXJ by reducing their speed of migration. YZXJ markedly reduced the migration and in vitro invasiveness induced by HGF. It worked synergistically with PHA665752 and SU11274, HGF receptor inhibitors on the lung cancer cells both on HGF receptor activation and on cell functions. A combination of HGF and EGF resulted in a greater increase in cell migration, which was similarly inhibited by YZXJ, and in combination with the HGF receptor and EGF receptor inhibitors. In vivo, YZXJ reduced the rate of tumour growth and potentiated the effects of PHA665752 on tumour growth. It was further revealed that YZXJ significantly reduced the degree of phosphorylation of the HGF receptor in lung tumours. CONCLUSION: YZXJ has a significant role in reducing the migration, invasion and in vivo tumour growth of lung cancer and acts to inhibit the migratory and invasive effects induced by HGF and indeed by HGF/EGF. This effect is likely attributed to the inhibition of the HGF receptor activation. These results indicate that YZXJ has a therapeutic role in lung cancer and that combined strategy with methods to block HGF and EGF should be considered. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12967-015-0639-1) contains supplementary material, which is available to authorized users
Mother-male bond, but not paternity, influences male-infant affiliation in wild crested macaques
In promiscuous primates, interactions between adult males and infants have rarely been investigated. However, recent evidence suggests that male affiliation towards infants has an influence on several aspects of the infantsâ life. Furthermore, affiliations may be associated with male reproductive strategy. In this study, we examined which social factors influenced male-infant affiliation initiated by either male or infant, in wild crested macaques (Macaca nigra). We combined behavioral data and genetic paternity analysis from 30 infants living in three wild groups in Tangkoko Reserve, Indonesia. Our results indicate that adult males and infants do not interact at random, but rather form preferential associations. The social factors with the highest influence on infant-initiated interactions were male rank and male association with the infantâs mother. While infants initiated affiliations with males more often in the absence of their mothers, adult males initiated more affiliations with infants when their mothers were present. Furthermore, males initiated affiliations more often when they were in the same group at the time the infant was conceived, when they held a high dominance rank or when they had a close relationship with the mother. Interestingly, paternity did not affect male-infant affiliation despite being highly skewed in this species. Overall, our results suggest that adult males potentially associate with an infant to secure future mating with the mother. Infants are more likely to associate with a male to receive better support, suggesting a strategy to increase the chance of infant survival in a primate society with high infant mortality
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