Measurement of anisotropic volumetric resistivity in lithium ion electrodes.

Measurements of the electronic conductivity of lithium ion coatings are an important part of electrode development, particularly for thicker electrodes and in high power applications. A resistance measurement system with 46 probes has been used to characterise lithium ion electrodes, with different formulations and coat weights. The results show that the total through plane resistance is dominated by the interface resistance between the coating and the metal foil, rather than the volumetric resistivity of the coating. For coatings containing carbon nano-tubes, the in plane resistivities in the coating and perpendicular directions are different. A finite volume model was developed to help analyse and interpret the resistivity data.

Binder-free Sn-Si heterostructure films for high capacity Li-ion batteries.

This study fabricated and demonstrated a functional, stable electrode structure for a high capacity Li-ion battery (LIB) anode. Effective performance is assessed in terms of reversible lithiation for a significant number of charge-discharge cycles to 80% of initial capacity. The materials selected for this study are silicon and tin and are co-deposited using an advanced manufacturing technique (plasma-enhanced chemical vapour deposition), shown to be a scalable process that can facilitate film growth on 3D substrates. Uniform and hybrid crystalline-amorphous Si nanowire (SiNW) growth is achieved via a vapour-liquid-solid mechanism using a Sn metal catalyst. SiNWs of less than 300 nm diameter are known to be less susceptible to fracture and when grown this way have direct electrical conductivity to the current collector, with sufficient room for expansion. Electrochemical characterisation shows stable cycling at capacities of 1400 mA h g-1 (>4 × the capacity limit of graphite). This hybrid system demonstrates promising electrochemical performance, can be grown at large scale and has also been successfully grown on flexible carbon paper current collectors. These findings will have impact on the development of flexible batteries and wearable energy storage.

Focused time-lapse analysis reveals novel aspects of human fertilization and suggests new parameters of embryo viability.

STUDY QUESTION: Can focused application of time-lapse microscopy (TLM) lead to a more detailed map of the morphokinetics of human fertilization, revealing novel or neglected aspects of this process? SUMMARY ANSWER: Intensive harnessing of TLM reveals novel or previously poorly characterised phenomena of fertilization, such as a cytoplasmic wave (CW) preceding pronuclear formation and kinetics of pronuclear chromatin polarization, thereby suggesting novel non-invasive biomarkers of embryo quality. WHAT IS KNOWN ALREADY: In recent years, human preimplantation development has been the object of TLM studies with the intent to develop morphokinetic algorithms able to predict blastocyst formation and implantation. Regardless, our appreciation of the morphokinetics of fertilization remains rather scarce, currently including only times of polar body II (PBII) emission, pronuclear appearance and fading, and first cleavage. This is not consistent with the complexity and importance of this process, calling for further TLM studies aimed at describing previously unrecognized or undetected morphokinetic events and identifying novel developmental biomarkers. STUDY DESIGN, SIZE, DURATION: The study involved a retrospective observation by TLM of the fertilization process in 500 oocytes utilized in consecutive ICSI cycles carried out in 2016. A maximum of five fertilized oocytes per patients were included in the analysis to reduce possible patient-specific biases. Oocytes of patients with different diagnoses of infertility where included in the analysis, while cases involving cryopreserved gametes or surgically retrieved sperm were excluded. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Microinjected oocytes where assessed by a combined TLM-culture system (Embryoscope). Oocytes that were not amenable to TLM assessment, due to excess of residual corona cells or inadequate orientation for the observation of PBII emission, were not analysed. We identified and monitored 28 parameters relevant to meiotic resumption, pronuclear dynamics, chromatin organization, and cytoplasmic/cortical modifications. Times (T) were expressed as mean ± SD hours post-insemination (p.i.) and analysed, where appropriate, by Paired T Student or Fisher's exact tests. MAIN RESULTS AND ROLE OF CHANCE: PBII emission was occasionally followed (4.3% of cases) by the transient appearance of a protrusion of the cell surface, the fertilization cone (FC), probably resulting from interaction of the male chromatin with the oocyte cortex. Pronuclear formation was always preceded by a radial CW originating from the initial position of the male pronucleus (PN) and extending towards the oocyte periphery. The appearance of the CW followed a precise sequence, occurring always 2-3 h after PBII emission and shortly before PN appearance. Male and female PN appeared virtually simultaneously at approximately 6.2 h p.i. However, while the female PN always formed cortically and near the site of emission of the PBII, the initial position of the male PN was cortical, intermediate, or central (15.2%, 31.2% and 53.6%, respectively). PN juxtaposition involved rapid and straight movement of the female PN towards the male PN. In addition, the initial position of male PN formation was predictive of the position of PN juxtaposition. It was also observed that nucleolar precursor bodies (NPBs) aligned along the juxtaposition area and this happened considerably earlier for the female PN (8.2 ± 2.6 vs.11.2 ± 4.1 h, P = 0.0001). Although it occurred rarely, displacement of juxtaposed PN to the cortex was strongly associated (P < 0.0001) with direct cleavage into three blastomeres at the first cell division. The times of PN breakdown and first cleavage showed a very consistent trend, occurring earlier or progressively later depending on whether initial male PN positioning was central, intermediate or cortical, respectively. Finally, time intervals between discrete fertilization events were strongly associated with embryo quality on Day 3. For example, longer intervals between disappearance of the cytoplasmic halo and PN breakdown were highly predictive of reduced blastomere number and increased fragmentation (P = 0.0001). LARGE SCALE DATA: N/A. LIMITATIONS, REASON FOR CAUTION: Some of the morphokinetic parameters assessed in this study may require better definition to reduce inter-operator annotation variability. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, overall, these data represent the most detailed morphokinetic description of human fertilization. Many of the illustrated parameters are novel and may be amenable to further elaboration into algorithms able to predict embryo quality, as suggested by the findings presented in this study. STUDY FUNDING/COMPETING INTERESTS: None.

Towards High Capacity Li-ion Batteries Based on Silicon-Graphene Composite Anodes and Sub-micron V-doped LiFePO4 Cathodes.

Lithium iron phosphate, LiFePO4 (LFP) has demonstrated promising performance as a cathode material in lithium ion batteries (LIBs), by overcoming the rate performance issues from limited electronic conductivity. Nano-sized vanadium-doped LFP (V-LFP) was synthesized using a continuous hydrothermal process using supercritical water as a reagent. The atomic % of dopant determined the particle shape. 5 at. % gave mixed plate and rod-like morphology, showing optimal electrochemical performance and good rate properties vs. Li. Specific capacities of >160 mAh g-1 were achieved. In order to increase the capacity of a full cell, V-LFP was cycled against an inexpensive micron-sized metallurgical grade Si-containing anode. This electrode was capable of reversible capacities of approximately 2000 mAh g-1 for over 150 cycles vs. Li, with improved performance resulting from the incorporation of few layer graphene (FLG) to enhance conductivity, tensile behaviour and thus, the composite stability. The cathode material synthesis and electrode formulation are scalable, inexpensive and are suitable for the fabrication of larger format cells suited to grid and transport applications.

Effect of different gonadotrophin priming on IVM of oocytes from women with normal ovaries: a prospective randomized study.

This study was designed to determine if the efficiency of in-vitro maturation (IVM) in women with normal ovaries can be improved by gonadotrophin administration. 400 women were randomly allocated in four groups: group A, non-primed cycles; group B, human chorionic gonadotrophin (HCG)-primed cycles; group C, FSH-primed cycles; and group D, FSH- plus HCG-primed cycles. There were significant differences in the IVM rate among the groups. In groups where HCG was used, the overall maturation rate was higher (57.9% in group B and 77.4% in group D; 48.4% in group A and 50.8% in group C) and the percentage of total available metaphase II-stage oocytes was higher (60.4% in group B and 82.1% in group D; 48.4% in group A and 50.8% in group C). The overall clinical pregnancy rate per transfer (CPR) was 18.3% and the implantation rate (IR) was 10.6%. There was a difference in CPR among the groups: group D (29.9%) versus group A (15.3%), P = 0.023; group D versus group B (7.6%), P < 0.0001; group D versus group C (17.3%), P = 0.046. The results of this study are clearly in favour of FSH plus HCG priming. FSH priming and HCG priming alone showed no significant effects on clinical outcome.

Predictive factors in in-vitro maturation in unstimulated women with normal ovaries.

The in-vitro maturation protocol (IVM) is an intriguing tool in assisted reproduction since it omits the side-effects of drug stimulation and reduces the cost of the entire procedure, both in terms of time and patient/society costs. In the Biogenesi Reproductive Medicine Centre, the IVM technique has been applied for more than 3 years, obtaining successful results in terms of maturation and fertilization rates, number of pregnancies and healthy babies born. At present, IVM is widely accepted in polycystic ovary and polycystic ovarian syndrome patients but its application in other women is still controversial. This study has been carried out in order to determine the efficiency of unstimulated IVM in women with morphologically and endocrinologically normal ovaries. Body mass index, basal FSH and oestradiol concentrations, antral follicle count, endometrial thickness and lead follicle size were correlated with the outcome of the procedure so as to obtain useful criteria to select women with regular cycles for an IVM technique. It was found that basal oestradiol concentration, FSH concentration and antral follicle count are useful criteria in deciding whether to start and continue the procedure, while lead follicle size and endometrial thickness are important criteria in deciding the timing of oocyte retrieval.

Late entry into HIV/AIDS medical care: the importance of past relationships with medical providers.

Data are presented from a qualitative study that explored the impact of relationships with medical providers on late entry into HIV/AIDS medical care. In-depth interviews were conducted with ten males living on the US-Mexico border who entered medical care late in the progression of HIV. The findings focus on past relationships with medical providers and the perception of risk on both the part of the medical provider and the study participant. Current policy and programmatic trends and recommendations are discussed.

Psicosis cicloides: a propósito de un caso / Cycloid psychosis: a propos of a case

El concepto de psicosis cicloide se ha ido desarrollando y modificando a lo largo de los años. A pesar de que actualmente no se contempla como tal en los manuales diagnósticos al uso, hay numerosos pacientes que podrían ser incluidos en este diagnóstico controvertido. Se presenta el caso de una paciente que cumpliría los criterios clásicos de psicosis cicloide. Se realiza un repaso sobre esta entidad desde los puntos de vista diagnóstico y pronóstico. Se debate, además, la necesidad de instaurar un tratamiento antipsicótico y eutimizante en las fases agudas y de mantenimiento de la enfermedad (AU)

LC-MS analysis of serotonergic drugs.

Separating drugs which are both polar and basic has long been difficult because of the limited operating pH range of conventional HPLC columns. This paper describes a liquid chromatographic method capable of being used with either diode-array or mass spectrometric detection for the identification and quantitation of 10 antidepressant and 2 antipsychotic drugs, all of which have serotonergic activity. In developing the method, the effects of varying buffers and mobile phase pH and of adding modifying agents on resolution and capacity factors were investigated. The organic buffers ammonia, glycine, and triethylamine were each used in a mobile phase made up of 32.5% buffer/67.5% methanol (v/v) at a pH of 10.0. Additionally, four different concentrations each of tetrahydrofuran and acetonitrile were added to investigate the effect of a modifying agent on resolution and retention. In general, decreasing mobile phase pH reduced retention times and decreased resolution. Adding tetrahydrofuran in place of the same amount of methanol tended to decrease retention times, and adding acetonitrile tended to slightly increase retention times. However, addition of both marginally improved resolution. This method has been used to satisfactorily analyze brain, blood, liver, urine, vitreous fluid, and stomach contents in subjects known to have used these drugs.

[Cognitive impairment in a 35 years-old male]. / Deterioro cognitivo en varón de 35 años.

Cognitive impairment is a syndrome with multiple causes, presenting frequently neuropsychiatric symptoms. In these cases, the psychiatrist role is essential, including both diagnosis and therapy.HIV-associated dementia usually includes psychiatric symptoms, even in the absence of neurological symptoms in initial stages. Moreover, the prolonged life span of patients with HIV leaves the possibility that prevalence or HIV-associated neurologic disease increases in coming years. We report a case of a HIV male with insidious cognitive impairment, making diagnosis difficult due to ambiguous symptoms. The patient begins with depressive symptoms and slightly develops cognitive impairment. The presence of cognitive impairment in a young person must alert us think about HIV pathology, because it is one of the leading causes of dementia in the young.

Deterioro cognitivo en varón de 35 años / Cognitive impairment in a 35 years-old male

El deterioro cognitivo es un síndrome que puede deberse a múltiples causas, presentando frecuentemente síntomas neuropsiquiátricos añadidos. En esos casos, el papel del psiquiatra es fundamental, tanto en la vertiente diagnóstica como terapéutica.El complejo demencia-sida generalmente incluye síntomas psiquiátricos, incluso en ausencia de síntomas neurológicos en las fases iniciales.Además, la mayor esperanza de vida de los pacientes infectados por el virus de la inmunodeficiencia humana (VIH) probablemente conllevará un aumento de la prevalencia de los trastornos neurológicos asociados al VIH en los próximos años.Presentamos un caso de un varón infectado por VIH que presenta un deterioro cognitivo insidioso, que dificulta el diagnóstico inicial debido a la presencia de síntomas ambiguos. El paciente comienza con síntomas depresivos y lentamente progresa hacia un deterioro cognitivo.La presencia de deterioro cognitivo en una persona joven nos debe hacer descartar patología asociada a VIH, ya que ésta es en la actualidad una de las causas principales de demencia entre los jóvenes (AU)