Ion Beam Induced Charge Microscopy of Integrated Circuits

The ion beam induced charge (IBIC) microscopy technique has recently been developed as a means of imaging the depletion regions of working microelectronic devices beneath their thick metallisation and passivation layers. IBIC microscopy is analogous to electron beam induced current microscopy but has the advantages of a larger analytical depth, lower lateral scattering of the incident focused MeV ion beam and negligible charging effects. These characteristics enable IBIC to image small, buried active device regions without the need to remove the surface layers prior to analysis. The basis of this new technique is outlined and the applications for integrated circuit analysis, characterising upset mechanisms, and for imaging dislocation networks in semiconductor wafers are reviewed

Supervised physical activity and the incidence of gestational diabetes mellitus: a systematic review and meta-analysis

Background: Gestational diabetes mellitus (GDM) characterized by dysfunction in maintaining glucose homeostasis is recognized as the most common metabolic complication associated with pregnancy leading to adverse clinical outcomes for maternal and fetal health. Although previous analysis of the findings from randomized controlled trials (RCTs) support that regular physical activity reduces the incidence of GDM during pregnancy, less is known about the optimal timing of intervention with respect to trimester stage. Objectives: To examine the interaction between both the timing and volume of supervised physical activity interventions on reducing the incidence of GDM during pregnancy. Study design: Electronic databases including CINAHL, Embase, Medline and the Cochrane library were searched for records up to 29 September 2022. Eligibility criteria were RCTs including standard antenatal care þ supervised physical activity intervention without dietary modification vs. those receiving standard antenatal care alone in women with no previous diagnosis of GDM, type 1 or type 2 diabetes mellitus. Results: Of the 3411 records identified, 20 RCTs comprising 6732 participants were included. It was found that supervised physical activity interventions decreased GDM risk when started within the first trimester (RR: 0.57, 95% CI: 0.41–0.79; p ¼ .001) and by accumulating >600 METminwk1 of exercise (RR: 0.77, 95% CI: 0.60–0.98; p ¼ .03) compared with standard antenatal care alone. Women with a BMI 25 kg/m2 experienced the greatest risk reduction in GDM following supervised exercise training (RR: 0.51, 95% CI: 0.34–0.75; p ¼ .001). Conclusion: Supervised physical activity reduces the incidence of GDM during pregnancy. It is recommended that pregnant individuals achieve a minimum of 600 METminwk1 of physical activity during the first trimester in order to reduce their odds of developing GDM. Attaining a healthy pre-pregnancy BMI is also an important determinant for the prevention of GDM with exercise

Dislocation imaging of an InAlGaAs opto-electronic modulator using IBICC

This paper presents ion beam induced charge collection (IBICC) contrast images showing regions of differing charge collection efficiency within optoelectronic modulator devices. The experiments were carried out at the Sandia nuclear microprobe using 18 MeV carbon and 2 MeV helium ions. Lines of varying densities are observed to run along the different {l_brace}110{r_brace} directions which correlate with misfit dislocations within the 392nm thick strained layer superlattice quantum well of the modulator structure. Independent cross-sectional TEM studies and the electrical properties of the devices under investigation suggest the presence of threading dislocations in the active device region at a density of {approximately} 10{sup 6} cm{sup {minus}2}. However, no clear evidence of threading dislocations was observed in the IBICC images as they are possibly masked by the strong contrast of the misfit dislocations. Charge carrier transport within the modulator is used to explain the observed contrast. The different signal to noise levels and rates of damage of the incident ions are assessed

Topographic patterns of brain activity in response to swim stress: assessment by 2-deoxyglucose uptake and expression of Fos-like immunoreactivity

Alterations in brain activity patterns were assessed in response to swim stress by immunocytochemical detection of Fos-like immunoreactivity (Fos-LI) and high-resolution autoradiographic imaging of 14C-2-deoxyglucose (2-DG) uptake. The stress paradigm investigated was a classic behavioral screen for antidepressant drug activity, the forced swim test. One of the most pronounced effects produced by swim stress was an increase in 2-DG uptake and induction of Fos-LI in a restricted region of the lateral septal nucleus. Specific "limbic" cortical regions, including the medial prefrontal, ventrolateral orbital, and cingulate cortices, also exhibited both increased 2-DG uptake and expression of Fos-LI in response to swim stress. In the hypothalamic paraventricular nucleus of swim-stressed rats, Fos-LI was induced but no change in 2-DG uptake was apparent. Since the specific swim stress protocol used is a behavioral screen for antidepressant drugs, the effects of imipramine on stress-induced alterations in 2-DG uptake and induction of Fos-LI were examined. The stress-induced increase in 2-DG uptake in the lateral septum was blocked by treatment with imipramine, but treatment with imipramine had no effect on induction of Fos-LI in the same region. Neither 2-DG uptake nor Fos-LI expression was altered by imipramine treatment in the cortical regions influenced by swim stress. Administration of imipramine alone under basal conditions produced a robust induction of Fos-LI in the central nucleus of the amygdala and in the dorsal lateral subdivision of the bed nucleus of the stria terminalis. No effect of imipramine treatment on 2-DG uptake was apparent in these latter regions. The results provide insights into topographic patterns of brain activity associated with swim stress and neuroanatomically selective actions of imipramine. The different and complementary information obtained by assessment of Fos-LI and 2-DG uptake illustrates the utility of applying both functional mapping approaches to examine neuroanatomical correlates of behavioral states and drug treatment

SIMULTANEOUS QUANTIFICATION OF DOPAMINE, 5-HYDROXYTRYPTAMINE AND FOUR METABOLICALLY RELATED COMPOUNDS BY MEANS OF REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

A method for simultaneously quantifying dopamine, 5-hydroxytryptamine (5-HT) and four metabolically related compounds has been developed, permitting more efficient neurochemical examination of these often interrelated biogenic amine systems. The method uses high-performance liquid chromatographic separation of these compounds on a C18 reversed-phase column with a buffered mobile phase containing methanol as an organic modifier and heptanesulfonate as an ion-pair reagent. Using 5-hydroxy-N-methyltryptamine as an internal standard and electrochemical detection, chromatography time is less than 12 min. Sample preparation simply involves the addition of internal standard, homogenization in the mobile phase, centrifugation and injection of the supernatant into the chromatograph. The method is sensitive to a tissue content of these compounds of less than 1 ng. The utility of this method for neuropharmacological—neurochemical studies is illustrated with studies using inhibitors of monoamine oxidase (pargyline) and aromatic amino acid decarboxylase (RO 4-4602)