Charge Dynamics and Optolectronic Properties in HgTe Colloidal Quantum Wells.

We investigate the electronic and transport properties of HgTe 2D colloidal quantum wells. We demonstrate that the material can be made p- or n-type depending on the capping ligands. In addition to the control of majority carrier type, the surface chemistry also strongly affects the photoconductivity of the material. These transport measurements are correlated with the electronic structure determined by high resolution X-ray photoemission. We attribute the change of majority carriers to the strong hybridization of an n-doped HgS layer resulting from capping the HgTe nanoplatelets by S2- ions. We further investigate the gate and temperature dependence of the photoresponse and its dynamics. We show that the photocurrent rise and fall times can be tuned from 100 µs to 1 ms using the gate bias. Finally, we use time-resolved photoemission spectroscopy as a probe of the transport relaxation to determine if the observed dynamics are limited by a fundamental process such as trapping. These pump probe surface photovoltage measurements show an even faster relaxation in the 100-500 ns range, which suggests that the current performances are rather limited by geometrical factors.

Strongly Confined HgTe 2D Nanoplatelets as Narrow Near-Infrared Emitters.

Two-dimensional colloidal nanoplatelets (NPLs), owing to the atomic-level control of their confined direction (i.e., no inhomogeneous broadening), have demonstrated improved photoluminescence (PL) line widths for cadmium chalcogenide-based nanocrystals. Here we use cation exchange to synthesize mercury chalcogenide NPLs. Appropriate control of reaction kinetics enables the 2D morphology of the NPLs to be maintained during the cation exchange. HgTe and HgSe NPLs have significantly improved optical features compared to existing materials with similar band gaps. The PL line width of HgTe NPLs (40 nm full width at half-maximum, centered at 880 nm) is a factor of 2 smaller than typical PbS nanocrystals (NCs) emitting at the same wavelength. The PL has a lifetime of 50 ns, almost 2 orders of magnitude shorter than small PbS colloidal quantum dots (CQDs), and a quantum yield of ∼10%, almost 2 orders of magnitude shorter than small PbS colloidal quantum dots (CQDs). These materials are promising for a large variety of applications spanning from telecommunications to the design of colloidal topological insulators.

Cobalt-catalyzed diastereoselective synthesis of C-furanosides. Total synthesis of (-)-isoaltholactone.

An array of C-aryl and C-vinyl furanosides were prepared in good yields and diastereoselectivities from C-halogeno furanosides either with aryl Grignard or with vinyl Grignard using the convenient Co(acac)3/TMEDA catalytic system. This method is illustrated by the total synthesis of the (-)-isoaltholactone.

Photoconductive focal plane array based on HgTe quantum dots for fast and cost-effective short-wave infrared imaging.

HgTe nanocrystals, thanks to quantum confinement, present a broadly tunable band gap all over the infrared spectral range. In addition, significant efforts have been dedicated to the design of infrared sensors with an absorbing layer made of nanocrystals. However, most efforts have been focused on single pixel sensors. Nanocrystals offer an appealing alternative to epitaxially grown semiconductors for infrared imaging by reducing the material growth cost and easing the coupling to the readout circuit. Here we propose a strategy to design an infrared focal plane array from a single fabrication step. The focal plane array (FPA) relies on a specifically designed readout circuit enabling in plane electric field application and operation in photoconductive mode. We demonstrate a VGA format focal plane array with a 15 µm pixel pitch presenting an external quantum efficiency of 4-5% (15% internal quantum efficiency) for a cut-off around 1.8 µm and operation using Peltier cooling only. The FPA is compatible with 200 fps imaging full frame and imaging up to 340 fps is demonstrated by driving a reduced area of the FPA. In the last part of the paper, we discuss the cost of such sensors and show that the latter is only driven by labor costs while we estimate the cost of the NC film to be in the 10-20 € range.

The complex optical index of PbS nanocrystal thin films and their use for short wave infrared sensor design.

As nanocrystals (NCs) gain maturity, they become central building blocks for optoelectronics in devices such as solar cells and, more recently, infrared focal plane arrays. Now that the proof of concept of these devices has been established, their optimization requires a deeper understanding of their electronic and optical features to engineer their optoelectronic properties accurately. Though PbS NCs have been extensively investigated, the complex optical index of PbS NC thin films remains mostly unknown. Some previous works have unveiled the optical index for this type of material optimized for solar cells (excitonic peak at 940 nm), but longer wavelengths remain scarce and surface chemistry effects, which are known to be of central importance for layer doping, are simply unexplored. Here, we conduct a systematic investigation of the complex optical index of PbS NC thin films using broadband spectrally resolved ellipsometry. The obtained results are then compared with simulations combining tight-binding (TB) modeling at the NC level and the Bruggeman model to expand the results to the film scale. While TB calculation gives the NC optical indices, we extract the key NC film parameters such as the NC volume fraction and ligand indices by fitting the Bruggeman formula to ellipsometry measurements. We also bring evidence that this joint modeling method can be conducted without the need for ellipsometry data while preserving the main feature of the experimental results. Finally, the unveiled optical indices are used to model the absorption of short-wave infrared diode stacks based on PbS NCs and are relevant for state-of-the-art devices. Our electromagnetic modeling shows that the absorption within the contact is now a major limitation of the current device operated at the telecom wavelength.

Relationship between erectile dysfunction and silent myocardial ischemia in type 2 diabetic patients with no known macrovascular complications.

INTRODUCTION: Erectile dysfunction (ED) is associated with cardiovascular disease (CVD) because it is highly prevalent among those with cardiovascular risk factors (CVRFs). Moreover, it precedes the development of CVD and is considered a subrogate marker of subclinical CVD. AIM: The aim of this study was to evaluate the presence of ED among patients with type 2 diabetes (DM2) without macroangiopathy, and to assess the association between ED and other CVRFs, chronic diabetes complications, silent myocardial ischemia (SMI), and peripheral arterial disease (PAD). METHODS: One hundred fifty-four male patients with DM2 and without clinical evidence of CVD were included in the study. The presence of ED, PAD, SMI, chronic diabetic complications, and other CVRFs was evaluated in these patients. MAIN OUTCOME MEASURES: PAD; SMI; ED; 24-hour blood pressure Holter; lipid profile; insulin resistance; testosterone; chronic inflammation; nephropathy; retinopathy; neuropathy. RESULTS: Prevalence of ED was 68.2%. Patients with ED were older and characterized by DM2, systolic blood pressure (BP), retinopathy, and insulin treatment of longer duration than patients without ED, even when adjusting for age was performed. Adjusting for duration of diabetic condition revealed significant differences in age and systolic BP. Independent factors for ED were age (57.7±7.5 years, relative risks [RR 1.1], P=0.003) and duration of diabetes (9[3-15] years, RR 1.1, P=0.006). SMI was detected in 13.6% of patients (18.1% in patients with ED vs. 4.1% in patients without ED). Asymptomatic PAD was detected in 13.2% of subjects (14.4% in patients with ED vs. 10.4% in patients without). CONCLUSIONS: ED is highly prevalent in DM2, and is associated with the presence of SMI, higher systolic BP and chronic microvascular diabetic complications.

Self-injurious and suicidal behaviour in a transsexual adolescent and young adult population, treated at a specialised gender identity unit in Spain. / Antecedentes de comportamientos autolesivos y autolíticos en población adolescente y adulta joven transexual, atendida en una unidad especializada en identidad de género en España.

INTRODUCTION: Nonsuicidal self-injury (NSSI) and suicidal behavior (SB) have a significant prevalence in transsexual people. The published data is confusing as it does not distinguish between ideation and realization, age groups, gender, or the degree of medical intervention. Their actual prevalence in Spain is unknown. OBJECTIVE: Our objective was to investigate the prevalence of NSSI behavior and SB in adolescents and young transsexual adults, differentiating between ideation and consummated behavior, prior to their receiving any type of gender-affirming medical treatment. MATERIAL AND METHODS: We retrospectively reviewed the medical history of a cohort of transsexual people aged between 10 and 35 years, treated at the Gender Identity Unit of the Valencian Community. We analyzed the data collected regarding the presence of four variables: NSSI ideation, NSSI behavior, ideas of suicide and suicide attempts, as well as differences according to age group and gender. RESULTS: The final sample consisted of 110 transsexual men and 90 transsexual women. Of these, 21% had made a suicide attempt, 50% had had suicidal ideas, 31% had a history of NSSI behavior and 35% had had NSSI ideas. No differences were found based on gender. Regarding age, subjects under 20 years of age presented a significantly higher prevalence regarding suicidal ideas compared to young adults (43% vs. 25%), while in the remaining variables, no statistically significant differences were found. CONCLUSIONS: The prevalence of a history of suicidal ideas and behavior in the Spanish adolescent and young transsexual population is significant and does not differ according to gender or age range. The prevalence of NSSI ideas and behavior differs and is more frequent in adolescent transsexuals.

Self-injurious and suicidal behaviour in a transsexual adolescent and young adult population, treated at a specialised gender identity unit in Spain.

INTRODUCTION: Nonsuicidal self-injury (NSSI) and suicidal behavior (SB) have a significant prevalence in transsexual people. The published data is confusing as it does not distinguish between ideation and realization, age groups, gender, or the degree of medical intervention. Their actual prevalence in Spain is unknown. OBJECTIVE: Our objective was to investigate the prevalence of NSSI behavior and SB in adolescents and young transsexual adults, differentiating between ideation and consummated behavior, prior to their receiving any type of gender-affirming medical treatment. MATERIAL AND METHODS: We retrospectively reviewed the medical history of a cohort of transsexual people aged between 10 and 35 years, treated at the Gender Identity Unit of the Valencian Community. We analyzed the data collected regarding the presence of four variables: NSSI ideation, NSSI behavior, ideas of suicide and suicide attempts, as well as differences according to age group and gender. RESULTS: The final sample consisted of 110 transsexual men and 90 transsexual women. Of these, 21% had made a suicide attempt, 50% had had suicidal ideas, 31% had a history of NSSI behavior and 35% had had NSSI ideas. No differences were found based on gender. Regarding age, subjects under 20 years of age presented a significantly higher prevalence regarding suicidal ideas compared to young adults (43% vs. 25%), while in the remaining variables, no statistically significant differences were found. CONCLUSIONS: The prevalence of a history of suicidal ideas and behavior in the Spanish adolescent and young transsexual population is significant and does not differ according to gender or age range. The prevalence of NSSI ideas and behavior differs and is more frequent in adolescent transsexuals.

Insulin Withdrawal in Diabetic Kidney Disease: What Are We Waiting for?

The prevalence of type 2 diabetes mellitus worldwide stands at nearly 9.3% and it is estimated that 20-40% of these patients will develop diabetic kidney disease (DKD). DKD is the leading cause of chronic kidney disease (CKD), and these patients often present high morbidity and mortality rates, particularly in those patients with poorly controlled risk factors. Furthermore, many are overweight or obese, due primarily to insulin compensation resulting from insulin resistance. In the last decade, treatment with sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP1-RA) have been shown to be beneficial in renal and cardiovascular targets; however, in patients with CKD, the previous guidelines recommended the use of drugs such as repaglinide or dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors), plus insulin therapy. However, new guidelines have paved the way for new treatments, such as SGLT2i or GLP1-RA in patients with CKD. Currently, the new evidence supports the use of GLP1-RA in patients with an estimated glomerular filtration rate (eGFR) of up to 15 mL/min/1.73 m2 and an SGLT2i should be started with an eGFR > 60 mL/min/1.73 m2. Regarding those patients in advanced stages of CKD, the usual approach is to switch to insulin. Thus, the add-on of GLP1-RA and/or SGLT2i to insulin therapy can reduce the dose of insulin, or even allow for its withdrawal, as well as achieve a good glycaemic control with no weight gain and reduced risk of hypoglycaemia, with the added advantage of cardiorenal benefits.

Testosterone levels in males with type 2 diabetes and their relationship with cardiovascular risk factors and cardiovascular disease.

INTRODUCTION: One of the factors involved in type 2 diabetes in males is a reduction in levels of testosterone, which has been shown to predict resistance to insulin and the development of cardiovascular diseases. AIM: To assess the levels of testosterone in patients with type 2 diabetes and to evaluate their relationship with cardiovascular risk factors, peripheral arterial disease (PAD) and silent myocardial ischemia (SMI). METHODS: Total testosterone and sex hormone binding globulin were measured and free and bioavailable testosterones were calculated using Vermeulen's formula. Levels of total testosterone > or = 12 nmol/L or free testosterone > 225 pmol/L were considered normal. PAD was evaluated using the ankle-brachial index. SMI was assessed using a baseline ECG, Doppler echocardiogram, 24-hour electrocardiogram (ECG) Holter, exercise stress testing (EST), nuclear stress (if EST inconclusive), and if the result was positive, a coronary angiography. MAIN OUTCOME MEASURES: PAD, SMI, testosterone, erectile dysfunction, 24-hour blood pressure Holter, body mass index (BMI), waist circumference, lipid profile, insulin resistance, chronic inflammation, United Kingdom Prospective Diabetes Study cardiovascular risk score, nephropathy, retinopathy, and neuropathy. RESULTS: The study population was composed of 192 diabetic males with a mean age of 56.1 +/- 7.8 years and without a history of vascular disease. Twenty-three percent presented total testosterone below normal and 21.8% presented low free testosterone. BMI, waist circumference, neuropathy, triglycerides, C-reactive protein (CRP), glucose, insulin, and HOMA-IR were found to be significantly incremented with respect to subjects with normal testosterone. There was a negative correlation of HOMA-IR with total testosterone. PAD was detected in 12% and SMI in 10.9% of subjects, and differences were not related to testosterone levels. CONCLUSIONS: We have verified the prevalence of low testosterone levels in male patients with type 2 diabetes and have related them to variations in BMI, waist circumference, neuropathy, triglycerides, CRP, glucose, insulin and HOMA-IR, but not with an increase of SMI or PAD.

Transsexuality: Transitions, detransitions, and regrets in Spain. / Transexualidad: transiciones, detransiciones y arrepentimientos en España.

INTRODUCTION: Health care demand by transsexual people has recently increased, mostly at the expense of young and adolescents. The number of people who report a loss of or change in the former identity feeling (identity desistance) has also increased. While these are still a minority, we face more and more cases of transsexual people who ask for detransition and reversal of the changes achieved due to regret. OBJECTIVE: To report our experience with a group of transsexual people in detransition phase, and to analyze their personal experience and their associated conflicts. MATERIAL AND METHODS: A cohort of 796 people with gender incongruence attending the Identity Gender Unit of Doctor Peset University Hospital from January 2008 to December 2018 was studied. Four of the eight documented cases of detransition and/or regret are reported as the most representative. RESULTS: Causes of detransition included identity desistance, non-binary gender variants, associated psicomorbidities, and confusion between sexual identity and sexual orientation. CONCLUSION: Detransition is a growing phenomenon that implies clinical, psychological, and social issues. Inadequate evaluation and use of medicalization as the only means to improve gender dysphoria may lead to later detransition in some teenagers. Comprehensive care by a multidisciplinary and experienced team is essential. As there are no studies reporting the factors predictive of detransition, caution is recommended in cases of atypical identity courses.

Spanish population trends in Internet searches for information on different diets. / Tendencia de la población española de búsqueda en internet sobre información relacionada con diferentes dietas.

OBJECTIVE: To use Google Trends to explore the trends of interest of the Spanish population regarding information related to different types of diets, focused on those that are popular and with evidence-based studies, over the last 10years. MATERIAL AND METHODS: The search trends referred to the terms «Mediterranean diet¼, «ketogenic diet¼, «low fat diet¼, «intermittent fasting¼ and «vegan diet¼ were analyzed. The relative search volumes (RSV) of the terms were compared. The direction of the trend was studied using the Spearman's correlation coefficient (SC). RESULTS: «Mediterranean diet¼ was the most widely searched term, with a median RSV of 16 (interquartile range [IQR] 6; range 8-100), though it exhibited a decreasing chronological trend (SC=-0.216). It was followed by «ketogenic diet¼, with an RSV of 8 (IQR 9; range 1-57); «vegan diet¼, with an RSV of 4 (IQR 5; range 0-16); «intermittent fasting¼, with an RSV of 2 (IQR 5; range 0-27), and «low fat diet¼, with an RSV of 1.16 (IQR 0; range 0-2). The term with the best correlation over time was «intermittent fasting¼ (SC=0.96), followed by «ketogenic diet¼ (SC=0.91) and «vegan diet¼ (SC=0.85). CONCLUSIONS: In Spain, the interest of the population in information about the Mediterranean diet is greater than for other diets. However, in recent years there has been a progressive increase in interest (measured as RSV) in other diets such as the ketogenic diet, vegan diet or intermittent fasting, and there has been a decrease in interest in the Mediterranean diet. The low fat diet does not generate interest in the Spanish population.

Type 1 diabetes mellitus and periodontal disease: relationship to different clinical variables.

OBJECTIVE: This study is designed to evaluate the frequency of periodontal disease in a group of patients with type 1 diabetes mellitus and how this relates with diabetes metabolic control, duration of diabetes, and presence of diabetic complications. METHODS: A comparison was made of periodontal parameters (plaque index, bleeding index, pocket depth and attachment loss) in a group of diabetic patients (n=90) versus a group of non-diabetics (n=90). Logistic regression analysis was performed to evaluate relationship between periodontal parameters and degree of metabolic control, the duration of the disease, and the appearance of complications. RESULTS: Diabetics had greater bleeding index (p< 0.01), deeper periodontal pockets (p< 0.01) and more periodontal attachment loss (p< 0.01) than non-diabetics. Deficient metabolic control and presence of diabetic complication were associated with higher bleeding index and pocket depth (p

Doping as a Strategy to Tune Color of 2D Colloidal Nanoplatelets.

Among colloidal nanocrystals, 2D nanoplatelets (NPLs) made of II-VI compounds appear as a special class of emitters with an especially narrow photoluminescence signal. However, the PL signal in the case of NPLs is only tunable by a discrete step. Here, we demonstrate that doping is a viable path to finely tune the color of these NPLs from green to red, making them extremely interesting as phosphors for wide-gamut display. In addition, using a combination of luminescence spectroscopy, tight-binding simulation, transport, and photoemission, we provide a consistent picture for the Ag+-doped CdSe NPLs. The Ag-activated state is strongly bound and located 340 meV above the valence band of the bulk material. The Ag dopant induces a relative shift of the Fermi level toward the valence band by up to 400 meV but preserves the n-type nature of the material.

Impact of dimensionality and confinement on the electronic properties of mercury chalcogenide nanocrystals.

We demonstrate the growth of 2D nanoplatelets (NPLs) made of a HgTe/CdS heterostructure, with an optical absorption reaching the shortwave infrared range. The material is an interesting platform to investigate the effect of dimensionality (0D vs. 2D) and confinement on the electronic spectrum and carrier dynamics in colloidal materials. We bring consistent evidence for the p-type nature of this material from transport and photoemission measurements. The majority carrier dynamics probed using pump-probe photoemission is found to be mostly dependent on the presence of a confinement barrier at the surface rather than on the material dimensionality. The minority carrier, on the other hand, is strongly affected by the material shape showing a longer lived minority carrier in 2D NPLs compared to their 0D equivalent with a similar band gap. Finally, we test the potential of this material for photodetection in the short-wave infrared range (SWIR) and show that fast photoresponse and detectivity reaching 109 Jones at room temperature can be achieved.

[Prevalence of metabolic syndrome in patients with coronary heart disease]. / Prevalencia del síndrome metabólico entre pacientes con cardiopatía isquémica.

BACKGROUND AND OBJECTIVE: We aimed to know the prevalence of classical cardiovascular risk factors, hyperinsulinism, insulin resistance and metabolic syndrome (MS) in a population with coronary heart disease (CHD) as compared with a population without personal or familial history of cardiovascular risk factors. SUBJECTS AND METHOD: This was an observational and transversal study of cardiovascular risk factors making up the MS in an adult population. 367 subjects aged 35-79 years (268 men and 99 women) were studied; 185 had CHD (141 men and 44 women) and 182 (127 men and 55 women) were included as a control population. 82 individuals of the control group who had no MS components were selected for the calculation of parameters of hyperinsulinism and the HOMA (Homeostasis Model Assessment) index in order to evaluate the insulin resistance. RESULTS: As compared with the control group, patients with CHD showed higher blood pressure (systolic and dyastolic), body mass index (BMI), triglicerydes and apo B100 concentrations, and lower HDL-c and apo A1 values. They also exhibited higher values of glycemia and insulinemia and consequently a higher HOMA index. The values of insulin and HOMA (percentil 75), obtained from the selected group for this purpose, were 12 U/ml and 3.03, respectively. In the CHD population, 38.28% (95% CI, 31.13-45.95) had hyperinsulinism, 47.02% (95% CI, 39.70-54.47) had insulin resistance (HOMA) and 41.08% (95% CI, 33.98-48.55) had MS. CONCLUSIONS: There was a high prevalence of cardiovascular risk factors in the CHD population. Patients with CHD have higher hyperinsulinism and insulin resistance as well as a greater prevalence of MS. Despite treatment, a clear association exists between MS and CHD in both men and women.

[Cardiovascular risk factors in patients with morbid obesity: weight loss influence]. / Factores de riesgo cardiovascular en pacientes con obesidad mórbida: influencia de la pérdida de peso.

BACKGROUND: We studied the presence of cardiovascular risk factors in patients with morbid obesity and analyzed the influence of weight loss achieved through diet on these factors. We also evaluated the influence of gender on the presence of cardiovascular risk factors and on its response to diet. PATIENTS AND METHODS: An anthropometric evaluation was performed in patients with morbid obesity (23 men and 36 women). The presence of cardiovascular risk factors was evaluated (fibrinogen, blood pressure, glucose metabolism determination by means of oral glucose tolerance test, complete lipid profile, sleep apnea syndrome), before and after following, on an alternative fashion, very-low calorie and low-calorie diets. The comparison was made with the t-test for paired samples. RESULTS: A very significant weight loss was achieved in our patients, particularly in men (decrease of 33.4 kg, 95% CI: 26.9 to 39.8). This was accompanied by a reduction in the presence of cardiovascular risk factors, particularly in men, in whom the body fat distribution improved significantly (decrease in waist: 24.8 cm, 95% CI 18.4 to 36.5), as well as the lipid profile including triglycerides, VLDLc, HDLc and B100 apoprotein. CONCLUSIONS: Patients with morbid obesity have a high prevalence of cardiovascular risk factors. A significant reduction of this prevalence can be achieved with diet during one year. This improvement is particularly significant in men.

Human leukocyte/endothelial cell interactions and mitochondrial dysfunction in type 2 diabetic patients and their association with silent myocardial ischemia.

OBJECTIVE: Diabetes is associated with oxidative stress and increased mortality, but a possible correlation between leukocyte-endothelium interactions, oxidative stress, and silent myocardial ischemia (SMI) is yet to be confirmed. RESEARCH DESIGN AND METHODS: Mitochondrial dysfunction and interactions between leukocytes and human umbilical vein endothelial cells were evaluated in 200 type 2 diabetic patients (25 with SMI) and 60 body composition- and age-matched control subjects. A possible correlation between these parameters and the onset of SMI was explored, and anthropometric and metabolic parameters were also analyzed. RESULTS: Waist, levels of triglycerides, proinflammatory cytokines (interleukin-6 and tumor necrosis factor-α), HbA1c, high-sensitivity C-reactive protein (hs-CRP), glucose, and insulin, and homeostasis model assessment of insulin resistance were higher in diabetic patients than in control subjects. However, no statistical differences in hs-CRP and insulin levels were detected when the data were adjusted for waist. None of these parameters varied between SMI and non-SMI patients. Mitochondrial function was impaired and leukocyte-endothelium interactions were more frequent among diabetic patients, which was evident in the lower mitochondrial O2 consumption, membrane potential, polymorphonuclear cell rolling velocity, and GSH/GSSG ratio, and in the higher mitochondrial reactive oxygen species production and rolling flux, adhesion, and vascular cell adhesion molecule-1 (VCAM-1) and E-selectin molecules observed in these subjects. Moreover, these differences correlated with SMI. Statistical differences were maintained after adjusting the data for BMI and waist, with the exception of VCAM-1 levels when adjusted for waist. CONCLUSIONS: Oxidative stress, mitochondrial dysfunction, and endothelium-inducing leukocyte-endothelium interactions are features of type 2 diabetes and correlate with SMI.