Texture, twinning and metastable "tetragonal" phase in ultrathin films of HfO₂ on a Si substrate

Thin HfO<sub>2</sub> films grown on the lightly oxidised surface of (100) Si wafers have been examined using dark-field transmission electron microscopy and selected area electron diffraction in plan view. The polycrystalline film has a grain size of the order of 100 nm and many of the grains show evidence of twinning on (110) and (001) planes. Diffraction studies showed that the film had a strong [110] out-of-plane texture, and that a tiny volume fraction of a metastable (possibly tetragonal) phase was retained. The reasons for the texture, twinning and the retention of the metastable phase are discussed

Advanced nanoanalysis of a Hf-based high-<i>k</i> dielectric stack prior to activation

Analytical electron microscopy techniques are used to investigate elemental distributions across a high-&lt;i&gt;k&lt;/i&gt; dielectric stack with a metal gate. Electron energy-loss spectroscopy results from a Si(100)/SiO2/HfO2/TiN/a-Si gate stack confirm the presence of an oxide interfacial phase at the TiN/a-Si interface prior to activation of the stack

Occurrence of testicular microlithiasis in androgen insensitive hypogonadal mice

&lt;b&gt;Background&lt;/b&gt;: Testicular microliths are calcifications found within the seminiferous tubules. In humans, testicular microlithiasis (TM) has an unknown etiology but may be significantly associated with testicular germ cell tumors. Factors inducing microlith development may also, therefore, act as susceptibility factors for malignant testicular conditions. Studies to identify the mechanisms of microlith development have been hampered by the lack of suitable animal models for TM.&lt;BR/&gt; &lt;b&gt;Methods&lt;/b&gt;: This was an observational study of the testicular phenotype of different mouse models. The mouse models were: cryptorchid mice, mice lacking androgen receptors (ARs) on the Sertoli cells (SCARKO), mice with a ubiquitous loss of androgen ARs (ARKO), hypogonadal (hpg) mice which lack circulating gonadotrophins, and hpg mice crossed with SCARKO (hpg.SCARKO) and ARKO (hpg.ARKO) mice.&lt;BR/&gt; &lt;b&gt;Results&lt;/b&gt;: Microscopic TM was seen in 94% of hpg.ARKO mice (n=16) and the mean number of microliths per testis was 81 +/- 54. Occasional small microliths were seen in 36% (n=11) of hpg testes (mean 2 +/- 0.5 per testis) and 30% (n=10) of hpg.SCARKO testes (mean 8 +/- 6 per testis). No microliths were seen in cryptorchid, ARKO or SCARKO mice. There was no significant effect of FSH or androgen on TM in hpg.ARKO mice.&lt;BR/&gt; &lt;b&gt;Conclusions&lt;/b&gt;: We have identified a mouse model of TM and show that lack of endocrine stimulation is a cause of TM. Importantly, this model will provide a means with which to identify the mechanisms of TM development and the underlying changes in protein and gene expression

Term and definition of a deformity after a spine trauma: Results of an international Delphi study

Introduction: Deformity of the spinal column after trauma could lead to pain, impaired function, and may sometimes necessitate extensive and high-risk surgery. This ‘condition’ has multiple terms and definitions that are used in research and clinics. A specific term and definition of this condition however is still lacking. A uniform and internationally accepted term and definition are necessary to compare cases and treatments in the future. Research question: Reach consensus on the term and definition of this deformity after spine trauma using a Delphi approach. Material and methods: An ‘all-rounds invitation’ Delphi process was used in this study among a group of international experts. The first round consisted of an online survey using input from preparatory studies, a typical clinical case and ICD-11 codes. The second round showed the results in-person and discussion was encouraged. Participants voted for rejection of certain terms. In the third round the final vote took place. When >80 % of the votes was for or against a term the term was rejected or accepted. Results: Response rate was high (≥84 %). The 3 Delphi rounds were completed. Unanimous voting led to the acceptance of the term and abbreviation as PSD. Deformity in any plane, pain, impaired function, and neurological deficit, were deemed important to include in the definition of PSD. Discussion and conclusion: Unanimous consensus was reached on ‘Posttraumatic spinal deformity: Condition where a trauma to the spine results in a deformity in any plane and results in pain and an impaired function with or without a neurological deficit.

Clinical, radiological, and patient-reported outcomes 13 years after pedicle screw fixation with balloon-assisted endplate reduction and cement injection

Purpose: In management of traumatic thoracolumbar burst fractures, short-segment pedicle screw fixation with balloon-assisted endplate reduction (BAER) and cement injection is a safe, feasible, and effective technique to maintain radiological alignment with minimum spinal segments involved. However, 20% of patients report daily discomfort despite good spinal alignment and fusion after this technique. This study provides clinical, radiological, and patient-reported outcomes after a minimum 13 years of follow-up. Methods: Eighteen patients were invited at the outpatient clinic for clinical/radiological examinations. The cohort (originally 20 patients) was treated 13–14 years earlier with pedicle screw fixation, BAER, and cement injection for traumatic thoracolumbar burst fractures. Patient-reported outcome measures were obtained at time of examinations. Current data were compared with data obtained at 6 years of follow-up. Results: Seventeen patients (median age 50; range 32–80) cooperated. No/minimal back pain was reported by 15 patients, and 12 patients returned to their previous heavy labor work. Median visual analog score of health (80%; 50–100%) was similar to results at 6 years (80%; 60–100% p = 0.259). An Oswestry Disability Index score of less than 20% (reflecting minimal disability) was reported by 14 patients, compared with 15 patients at 6 years of follow-up. No significant differences were found in wedge or Cobb angle between the time points. Intravertebral cement resorption was not observed. Conclusion: Results from this study suggest that, 13 years after pedicle screw fixation with BAER and cement injection for traumatic thoracolumbar burst fractures, functional performance, pain and radiological outcomes of the current cohort were stable or had slightly improved. Graphic abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.]

A test-proven As-grown-Generation (A-G) model for predicting NBTI under use-bias

For the first time, we demonstrate that A-G model extracted from short Vg-accelerated stresses can predict both long term DC and AC NBTI under low and dynamic operation Vg. This is achieved by successfully separating non-saturating defects from the saturating ones, allowing reliable extraction of power exponents needed for long term prediction. Unlike R-D model, A-G model does not require solving differential equations for AC NBTI. This saves computation time significantly, especially for high-frequency that needs small time-step, and makes it readily implementable in SPICE-like simulators

Postcolonial manifestations of African spatiality in Europe : the invisible 'public' spaces of Ghent

The focus of this chapter is on everyday spaces of African migration in the mid-sized city of Ghent. One manifestation of African spatiality is discussed in-depth in relation to its (in)visibility and publicity: an African shop located in an ordinary terraced house. With no less than 12 activities taking place in the building, the shop is rather a “public” place than solely a space of commercial transactions, although this is not signaled in very visible ways. By analyzing the modest stylistic appropriations of the façade and the significant re-arrangements of the buildings’ interior spaces that challenge more conventional usages of spaces in Ghent’s ordinary houses, this chapter puts this African shop to the fore as emblematic of how the process of materialization of transnational lifestyles and connections is always a balancing act between the visibility necessary for functioning as a (semi-)pubic place and the invisibility required to circumvent hegemonic regulatory regimes

Androgen receptor signalling in Vascular Endothelial cells is dispensable for spermatogenesis and male fertility

<p>Abstract</p> <p>Background</p> <p>Androgen signalling is essential both for male development and function of the male reproductive system in adulthood. Within the adult testis, Germ cells (GC) do not express androgen receptor (AR) suggesting androgen-mediated promotion of spermatogenesis must act via AR-expressing somatic cell-types. Several recent studies have exploited the Cre/lox system of conditional gene-targeting to ablate AR function from key somatic cell-types in order to establish the cell-specific role of AR in promotion of male fertility. In this study, we have used a similar approach to specifically ablate AR-signalling from Vascular Endothelial (VE) cells, with a view to defining the significance of androgen signalling within this cell-type on spermatogenesis.</p> <p>Findings</p> <p>AR expression in VE cells of the testicular vasculature was confirmed using an antibody against AR. A Cre-inducible fluorescent reporter line was used to empirically establish the utility of a mouse line expressing Cre Recombinase driven by the Tie2-Promoter, for targeting VE cells. Immunofluorescent detection revealed expression of YFP (and therefore Cre Recombinase function) limited to VE cells and an interstitial population of cells, believed to be macrophages, that did not express AR. Mating of Tie2-Cre males to females carrying a floxed AR gene produced Vascular Endothelial Androgen Receptor Knockout (VEARKO) mice and littermate controls. Ablation of AR from all VE cells was confirmed; however, no significant differences in bodyweight or reproductive tissue weights could be detected in VEARKO animals and spermatogenesis and fertility was unaffected.</p> <p>Conclusions</p> <p>We demonstrate the successful generation and empirical validation of a cell-specific knockout of AR from VE cells, and conclude that AR expression in VE cells is not essential for spermatogenesis or male fertility.</p