Electrochemical sensor for glutathione reductase based on screen-printed electrodes coated with 3,5-dinitrobenzoic acid-modified carbon nanotubes.

The preparation of a hybrid nanomaterial is reported by covalently attaching 3,5-dinitrobenzoic acid groups to the surface of oxidized multi-walled carbon nanotubes using 1,6-diaminohexane as cross-linking agent. This nanomaterial, modified with the redox mediator, was used as transduction element to construct an amperometric sensor for the efficient indirect determination of glutathione reductase at a low working potential of - 0.05 V, through the oxidation of unconsumed nicotinamide adenine dinucleotide phosphate (NADPH) in the enzymatic reaction. The sensor exhibited an excellent linear response in the range 1.6 to 174 µU/µL, with high reproducibility and selectivity. The developed device was successfully validated in real samples, accurately determining the active enzyme in diluted human serum, making it a promising alternative for the determination of glutathione reductase and other related NADPH-dependent enzymes with relevance in clinical analysis.

Certification system for multidisciplinary thoracic tumour boards.

In Spain, lung cancer (LC) is the fourth most common cancer. Managing LC involves different professionals, and cooperative and coordinated work is crucial. Therefore, important decisions are better made by Multidisciplinary Thoracic Tumour Boards (MTTBs). On the other hand, certification systems have proven to improve the structure of care, ultimately having a positive impact on patient survival. Herein, a multidisciplinary working group of 11 experts (a Radiologist, a Thoracic Surgeon, a Pulmonologist, a Radiotherapy Oncologist, four Medical Oncologists, a Hospital Managing Director, a Cytologist, and a Molecular Biologist specialist) proposed a standard to certify and evaluate MTTBs. The following components were suggested for the standard: minimum requirements for the MTTB, a mixed model developed in two stages (preparation and audit), a structure comprising three groups of indicators (Strategic and Management, Support, and Operational), three certification levels, and an audit process. In our opinion, certifying MTTBs is critical to improve the standard of care for LC patients.

Outbreak of dermatophilosis in horses possibly transmitted by sharing riding equipment.

The aim of this study is to describe an outbreak of dermatophilosis at an equestrian center in Castilla la Mancha (central Spain), which affected 16.6% (5/30) of the animals. Research was carried out to establish the mode of transmission and spread to other horses in the herd. Clinical features, diagnostic methods and treatment are also described.

O objetivo deste estudo é descrever um surto de dermatofilose em um centro equestre em Castilla la Mancha (centro da Espanha), no qual 16,6% (5/30) dos animais foram afetados. Foi realizada uma pesquisa para estabelecer o modo de transmissão e a disseminação para outros cavalos do rebanho. As características clínicas, os métodos de diagnóstico e o tratamento também são descritos.

Effects of different doses of caffeine on cognitive performance in healthy physically active individuals.

PURPOSE: Caffeine is a potent central nervous system stimulant that increases the activity of the prefrontal cortex and can improve various cognitive skills. An improvement in these cognitive skills can lead to further benefits in athletic performance. Therefore, it is necessary to clarify the dose-response of caffeine on cognitive performance. This study aimed to determine the effects of different doses of caffeine on sport-related cognitive aspects. METHODS: Twenty-nine healthy physically active young adults were recruited. All participants completed three trials under the following conditions: (a) placebo, (b) 3 mg/kg, or (c) 6 mg/kg body mass of caffeine. In each trial, different cognitive abilities were evaluated with the following battery of tests: reaction time (Dynavision™ D2), anticipation (Bassin Anticipation Timer), sustained attention (Go/No-Go and Eriksen Flanker Test) and memory tests. Moreover, the side effects and the perceived sensation index were recorded 24 h after each test. RESULTS: Reaction time only improved following 6 mg/kg of caffeine intake (Physical reaction time: -0.04 s, 95% CI -0.08 to -0.01 s, P = 0.036, d = 0.5; Motor reaction time: -0.04 s, 95% CI -0.07 to -0.01 s, P = 0.008, d = 0.6) compared to the placebo condition. Anticipation, sustained attention, and memory were not affected after either caffeine dose intake (all P > 0.05). In addition, the 6 mg/kg dose of caffeine augmented the occurrence of the side effects of increased activeness (P = 0.046) and nervousness (P = 0.001). CONCLUSION: Acute intake of 6 mg/kg caffeine is effective in improving reaction time despite increasing the occurrence of side effects in healthy physically active young adults. STUDY REGISTRATION: This study has been registered in ClinicalTrials whose ID is: NCT05995314 (2023-08-08).

Silicon Analogues of Cyclopropyl Radical Derived from a Highly Stable Cyclic Disilene Compound Featuring a Si-Br Bond.

A halogen-substituted cyclic disilene compound, bromocyclotrisilene, Si3Br(Eind)3 (3a), bearing fused-ring bulky Eind (a: R1 = R2 = Et) groups, has been synthesized as an extraordinarily air-stable compound by the reduction of 1,2-dibromodisilene, (Eind)BrSi═SiBr(Eind) (2a), or tribromosilane, (Eind)SiBr3 (1a), with the Mg or Li metal. The X-ray diffraction analysis of 3a showed that the disilene moiety has an almost planar, but slightly trans-bent structure. Even though 3a is quite air-stable both in solutions and in the solid state, its Si-Br bond is reactive under reducing conditions. The further treatment of 3a with the Li metal leads to the formation of room-temperature thermally stable silicon homologues of the cyclopropyl radical, i.e., the cyclotrisilanyl radicals (6a) [6a(syn) and 6a(anti)], via intramolecular C-H bond activation in a transient silicon homologue of the cyclopropenyl radical, i.e., the cyclotrisilenyl radical, [Si3(Eind)3]• (5a). The formation mechanism of 6a from 5a is discussed based on the theoretical calculations. The unique structural and electronic properties of these Si3 three-membered ring species incorporating the Eind groups have been experimentally and theoretically investigated.

General and Substantive Accountability in Nursing Home Services: Assessing Messages from the Demand Side and the Supply Side.

This study examines the extent to which general and substantive accountability is integrated into the language used by key actors involved in nursing home services. Particularly, we investigate the messages used by the supply side, which includes public and private organizations involved in residential care for older adults, and the demand side, which comprises organizations representing service beneficiaries. Moreover, we explore the alignment between the messages used by both sides of the accountability relationship. In the context of Spanish nursing homes, we analyzed a corpus of tweets by organizations from both sides of the accountability relationship, from one year before the outbreak of COVID-19 restrictions to after their implementation. Using text analysis techniques, we found that messages related to general and substantive accountability had a low priority before and after the outbreak. Public organizations were slightly more likely to employ general accountability terms than private organizations. This is particularly in non-crisis situations, although less frequently than organizations representing beneficiaries. Our analysis demonstrates a lack of convergence between the messaging on the supply and demand sides, indicating a communication breakdown between the two sides in the accountability relationship.

Self-propelled enzyme-controlled IR-mesoporous silica Janus nanomotor for smart delivery.

Here, we report the preparation of a novel Janus nanoparticle with opposite Ir and mesoporous silica nanoparticles through a partial surface masking with toposelective modification method. This nanomaterial was employed to construct an enzyme-powered nanomachine with self-propulsion properties for on-command delivery. The cargo-loaded nanoparticle was provided with a pH-sensitive gate and unit control at the mesoporous face by first attaching boronic acid residues and further immobilization of glucose oxidase through reversible boronic acid esters with the carbohydrate residues of the glycoenzyme. Addition of glucose leads to the enzymatic production of H2O2 and gluconic acid, being the first compound catalytically decomposed at the Ir nanoparticle face producing O2 and causing the nanomachine propulsion. Gluconic acid leads to a pH reduction at the nanomachine microenvironment causing the disruption of the gating mechanism with the subsequent cargo release. This work demonstrates that enzyme-mediated self-propulsion improved release efficiency being this nanomotor successfully employed for the smart release of Doxorubicin in HeLa cancer cells.

Placebo Effect of Caffeine on Physiological Parameters and Physical Performance.

This study aimed to analyse the placebo effect associated with a high dose of caffeine (9 mg/kg) on heart rate and its variability and on strength tests. METHODS: 18 participants experienced in strength training (19.7 ± 2.3 years; 72.2 ± 15.0 kg; 169.6 ± 9.0 cm) performed two days of trials (caffeine-informed/placebo-ingested (placebo) and non-ingested (control)). Firstly, heart rate and its variability were measured while participants lay down for 15 min. After that, bench press and squat tests were performed at 3 different loads (50%, 75% and 90% of 1RM). Perception of performance, effort and side effects were also evaluated. RESULTS: no differences were found in the vast majority of strength variables analysed. Resting heart rate decreased in the placebo trial (60.39 ± 10.18 bpm control vs. 57.56 ± 9.50 bpm placebo, p = 0.040), and mean RR increased (1020.1 ± 172.9 ms control vs. 1071.5 ± 185.7 ms placebo, p = 0.032). Heart rate variability and perception of performance and effort were similar between conditions (p > 0.05 in all cases). Side effects such as activeness and nervousness were reported while consuming the placebo. CONCLUSIONS: the placebo effect did not modify performance in the majority of the strength test variables, HRV and perception of performance and effort. However, resting heart rate was reduced, mean RR increased, and some side effects appeared in the placebo trial.

Difficulties on the access to innovative targeted therapies for lung cancer in Spain.

PURPOSE: Spanish Lung Cancer Group (SLCG) conducted a review to analyze the barriers to access to innovative targeted therapies for non-small cell lung cancer (NSCLC) in clinical practice in Spain. METHODS: Review all relevant content published on websites of European Commission, European Medicines Agency, and Spanish Agency of Medicines and Medical Products regarding the authorization and access to oncology treatments. RESULTS: More than 20 targeted therapies are available to treat different molecular alterations in patients with NSCLC. European Commission has approved treatments for genomic alterations involving the following genes: ALK, RET, ROS1, EGFR, BRAF, NTRK, KRAS, MET. However, the availability of these therapies in Spain is not complete, as innovative treatments are not reimbursed or funded late, with only five of these alterations currently covered by National Health System. CONCLUSION: SLCG considers imperative to improve the access in Spain to innovative treatments for NSCLC to reduce inequity across European countries.

Rescate endoscópico de endoprótesis biliar plástica fistulizante / Endoscopic rescue of a fistulizing biliary plastic stent

55-year-old male with a history of cholecystectomy complicated by perforation of the common bile duct, contained with placement of a plastic biliary stent. He presented several subsequent episodes of recurrent cholangitis secondary to biliary lithiasis and residual benign stenosis of the common bile duct, resolved with the implantation of plastic biliary prostheses. Finally, given the recurrent episodes of cholangitis, it was agreed to perform a hepaticojejunostomy. During the operation, the last implanted stent was not detected, which was identified by CT scan of the abdomen, causing a fistulous tract between the duodenum and the ascending colon. The stent was removed endoscopically, without complications, and the fistulous tract was resolved.(AU)

A Retrospective Analysis of High Resolution Ultrasound Evaluation of the "Split Fat Sign" in Peripheral Nerve Sheath Tumors.

Peripheral nerve sheath tumors (PNST) comprise schwannomas and neurofibromas. The finding of increased adipose tissue around benign PNSTs has been described as the "split fat sign" on magnetic resonance imaging exams, which is suggestive of an intramuscular or intermuscular location of the tumor. However, few studies have described this sign as a salient ultrasound feature of PNSTs. The main purpose of this study was to retrospectively evaluate the presence of increased fatty tissue deposition around benign PNSTs diagnosed by high-resolution ultrasound. In addition, we aimed to corroborate the presence of vascularization around the affected area. A retrospective analysis of ten cases of PNSTs and two cases of post-traumatic neuromas diagnosed by high-resolution ultrasound was performed with a Logiq® P8 ultrasound with a 2-11 MHz multifrequency linear probe L3-12-D (central frequency: 10 MHz). Localized types of neurofibromas and schwannomas in any location were seen as predominantly hypoechoic tumors with an oval or fusiform shape. Exiting and entering nerves (tail sign) were observed in six cases, showing localized lesions both in intermuscular and subcutaneous locations. The presence of increased hyperechoic tissue (the split fat sign) was noted in cases of solitary intermuscular and intramuscular peripheral nerve sheath tumors, mainly the schwannomas. Though small tumors did not demonstrate the tail sign, the increase in adipose tissue and vascularity on US was well demonstrated. In conclusion, the nerve in continuity forms the basis of the ultrasonographic diagnosis of PNSTs. However, high-resolution US can convincingly demonstrate the increased presence of fat in the upper and lower poles as well as circumferentially in intermuscular or intramuscular benign PNSTs.

Analysis of individual performance indicators of football goalkeeper

One of the most widely used strategies for performance analysis in different sports is notational analysis through direct observation of technical-tactical actions, which allows to understand the main indicators of sporting performance of the players, both individually and collectively. Football goalkeepers (GKs) are involved in the game differently when compared to the rest of the players in the team and, therefore, they develop different high-level and high-intensity tactical-technical actions. Therefore, the present work aimed to analyse the different performance indicators of football GKs through a search in the following databases: Web of Science (WOS), Scopus (Elsevier), PubMed (NIH) and, SPORTDiscus (EBSCO), until February 2023. The following keywords were used: "Football" or "Soccer", "Goalkeeper" and "Performance analysis". The results show that the main performance indicators are the percentage of avoided goals, the distribution of the ball at the goal kick as well as the number of offensive and defensive actions. Therefore, training sessions should be planned and implemented aimming to improve these skills. (AU)

Una de las estrategias más utilizadas para analizar el rendimiento en diferentes modalidades deportivas, es el análisis notacional a través de la observación directa de las acciones técnico-tácticas, lo que permite conocer los principales indicadores de rendimiento deportivo de los jugadores, tanto individual como colectivamente. Los porteros de fútbol tienen una involucración en el juego diferente comparativamente al resto de los jugadores del equipo, y, por ende, desarrollan diferentes acciones táctico-técnicas de alto nivel y de alta intensidad. Por ello, el objetivo del presente trabajo fui a analizar los diferentes indicadores de rendimiento de los porteros de fútbol mediante una búsqueda en las bases de datos: Web of Science (WOS), Scopus (Elsevier), PubMed (NIH) y SPORTDiscus (EBSCO), hasta febrero del 2023. Para ello, se emplearon las siguientes palabras claves, “Football” o “Soccer”, “Goalkeeper” y “Performance analysis”. Los resultados muestran como los principales indicadores de rendimiento son el porcentaje de goles evitados, la distribución del balón en el saque de portería, así como el número de acciones ofensivas y defensivas. Por tanto, se deben planificar e implementar sesiones de entrenamiento para la mejora de dichas habilidades. (AU)

PD-1/PD-L1 Inhibitors as Monotherapy in the First-Line Treatment of Advanced Non-Small Cell Lung Cancer Patients with High PD-L1 Expression: An Expert Position Statement.

INTRODUCTION: There are currently three first-line immunotherapy options used as monotherapy in advanced non-small cell lung cancer (NSCLC) patients with high programmed death ligand 1 (PD-L1) expression (≥50%). This manuscript aims to evaluate the available data on atezolizumab (AT), cemiplimab (CEMI), and pembrolizumab (PEMBRO) and to study the results obtained during pivotal trials, especially regarding patient subgroups. METHODS: Nominal group and Delphi techniques were used. Eight Spanish experts in lung cancer (the scientific committee of the project) analyzed the use of immunotherapy monotherapy as first-line treatment in patients with NSCLC and high PD-L1 expression. The expert scientific committee formulated several statements based on a scientific review and their own clinical experience. Subsequently, 17 additional Spanish lung cancer experts were selected to appraise the committee's statements through two Delphi rounds. They completed a Delphi round via an online platform and voted according to a scale from 1 (strongly disagree) to 10 (strongly agree). The statements were approved if ≥70% of experts voted 7 or more. RESULTS: A total of 20 statements were proposed covering the following areas: (1) general characteristics of pivotal clinical trials; (2) overall main outcomes of pivotal clinical trials; and (3) subgroup analysis. All statements reached consensus in the first round. CONCLUSIONS: AT, CEMI, and PEMBRO as monotherapy can be considered the standard of care in patients with advanced NSCLC and high PD-L1 expression (≥50%). Moreover, some differences noted among the drugs analyzed in this document might facilitate treatment decision-making, especially in clinically relevant patient subgroups, when using PD-1/PD-L1 inhibitors. The high level of agreement reached among experts supports the proposed statements.

An intercommunicated nanosystem for dual delivery.

Here, we describe the design of a novel particle-to-particle intercommunicated nanosystem for dual delivery, triggered by physical and chemical inputs. The nanosystem was composed of an Au-mesoporous silica Janus nanoparticle loaded with paracetamol, mechanized with light-sensitive supramolecular gates at the mesoporous face and functionalized on the metal surface with the enzyme acetylcholinesterase. The second component was a mesoporous silica nanoparticle loaded with rhodamine B and gated with thiol-sensitive ensembles. Upon irradiation of this nanosystem with a near-UV light laser, an analgesic drug was released from the Janus nanomachine due to disassembling of the photosensitive gating mechanism. Further addition of N-acetylthiocholine leads to the enzymatic production of thiocholine at the Janus nanomachine, thus acting as a "chemical messenger" causing the disruption of the gating mechanism at the second mesoporous silica nanoparticle with the subsequent dye release.

Semiempirical Two-Dimensional Model of the Bipolar Resistive Switching Process in Si-NCs/SiO2 Multilayers.

In this work, the SET and RESET processes of bipolar resistive switching memories with silicon nanocrystals (Si-NCs) embedded in an oxide matrix is simulated by a stochastic model. This model is based on the estimation of two-dimensional oxygen vacancy configurations and their relationship with the resistive state. The simulation data are compared with the experimental current-voltage data of Si-NCs/SiO2 multilayer-based memristor devices. Devices with 1 and 3 Si-NCs/SiO2 bilayers were analyzed. The Si-NCs are assumed as agglomerates of fixed oxygen vacancies, which promote the formation of conductive filaments (CFs) through the multilayer according to the simulations. In fact, an intermediate resistive state was observed in the forming process (experimental and simulated) of the 3-BL device, which is explained by the preferential generation of oxygen vacancies in the sites that form the complete CFs, through Si-NCs.

Influencia del ciclo menstrual en el rendimiento físico y cognitivo en mujeres eumenorreicas / Influence of the menstrual cycle on physical and cognitive performance in eumenorrheic women

Introducción: Las hormonas sexuales femeninas propias del ciclo menstrual no solo tienen funciones reproductivas, tambiéninfluyen en otros sistemas fisiológicos pudiendo afectar al rendimiento deportivo y cognitivo. El propósito del presente estudioha sido evaluar distintos aspectos como la composición corporal, la resistencia, la fuerza muscular y algunas capacidadescognitivas en diferentes etapas del ciclo menstrual. Material y método: En el estudio participaron ocho mujeres jóvenes eumenorreicas (edad = 23,1 ± 4,4 años) con ciclosmenstruales regulares. Se realizó una prueba de densitometría y una bioimpedancia para estudiar la composición corporal, unaprueba de memoria visual a corto plazo y un test de tiempo de reacción para evaluar habilidades cognitivas y se analizaroncaracterísticas del músculo (grosor y rigidez del recto anterior y fuerza muscular) junto a una prueba de esfuerzo para evaluarel rendimiento durante las fases folicular media (FF) y lútea media (FL) del ciclo menstrual de las participantes. Resultados: Durante la fase folicular las participantes registraron un mayor tiempo total (FF = 488,5 ± 93,18 s vs. FL = 468,6± 81,29 s; p = 0,015) y una frecuencia cardiaca inicial menor (FF = 83,3 ± 10,23 PPM vs. FL = 92,9 ± 7,67 PPM; p = 0,034) en laprueba de esfuerzo. Además, Respecto a las habilidades cognitivas, en la fase folicular se obtuvieron mejores resultados enel tiempo de reacción tanto con la mano derecha (FF = 0,426 ± 0,082 s vs. FL = 0,453 ± 0,087 s; p = 0,036) como con la manoizquierda (FF = 0,435 ± 0,096 s vs. FL = 0,466 ± 0,077 s; p = 0,034). Por otro lado, se encontró un mayor porcentaje de grasa(FF = 27,3 ± 5,1% vs. FL = 27,9 ± 5,0%; p = 0,041) en la fase lútea. Conclusión: El rendimiento en resistencia y en aspectos cognitivos como es el tiempo de reacción fue mejor en la FaseFolicular mientras que se observó un mayor porcentaje de grasa en la Fase Lútea. Sin embargo, la memoria, la fuerza y lascaracterísticas...(AU)

Introduction: The female sexual hormones typical of the menstrual cycle not only have reproductive functions, they alsoinfluence other physiological systems and can affect sports and cognitive performance. The purpose of this study has beento evaluate different aspects such as body composition, endurance, muscle strength and some cognitive abilities at differentstages of the menstrual cycle. Material and method: Eight young eumenorrheic women (age = 23.1 ± 4.4 years) with regular menstrual cycles participatedin the study. A densitometry and bioimpedance test were performed to study body composition, a short-term visual memorytest and a reaction time test to assess cognitive abilities, and muscle characteristics (thickness and stiffness of the anteriorrectus and muscle strength) along with a progressive test to exhaustion were analyzed to assess performance during themid-follicular (FF) and mid-luteal (FL) phases of the participants’ menstrual cycle. Results: During the follicular phase, the participants registered a greater total time (FF = 488.5 ± 93.18 s vs. FL = 468.6 ± 81.29 s;P = 0.015) and a lower initial heart rate (FF = 83.3 ± 10.23 PPM vs. FL = 92.9 ± 7.67 PPM; P = 0.034) in the progressive test toexhaustion. Regarding cognitive abilities, in the follicular phase, better results were obtained in reaction time both with theright hand (FF = 0.426 ± 0.082 s vs. FL = 0.453 ± 0.087 s; P = 0.036) and with the left hand (FF = 0.435 ± 0.096 s vs. FL = 0.466 ±0.077 s; P = 0.034). On the other hand, a higher percentage of fat (FF = 27.3 ± 5.1% vs. FL = 27.9 ± 5.0%; P = 0.041) was foundin the luteal phase. Conclusion: Performance in endurance and in cognitive test, such as reaction time was better in the Follicular Phase, whilea higher percentage of fat was observed in the Luteal Phase. However, memory, strength and muscular characteristics werenot affected by the hormonal fluctuations of the menstrual cycle.(AU)

Endoscopic rescue of a fistulizing biliary plastic stent.

55-year-old male with a history of cholecystectomy complicated by perforation of the common bile duct, contained with placement of a plastic biliary stent. He presented several subsequent episodes of recurrent cholangitis secondary to biliary lithiasis and residual benign stenosis of the common bile duct, resolved with the implantation of plastic biliary prostheses. Finally, given the recurrent episodes of cholangitis, it was agreed to perform a hepaticojejunostomy. During the operation, the last implanted stent was not detected, which was identified by CT scan of the abdomen, causing a fistulous tract between the duodenum and the ascending colon. The stent was removed endoscopically, without complications, and the fistulous tract was resolved.

Lysophosphatidylinositol Promotes Chemotaxis and Cytokine Synthesis in Mast Cells with Differential Participation of GPR55 and CB2 Receptors.

Mast cells (MCs) are the main participants in the control of immune reactions associated with inflammation, allergies, defense against pathogens, and tumor growth. Bioactive lipids are lipophilic compounds able to modulate MC activation. Here, we explored some of the effects of the bioactive lipid lysophosphatidylinositol (LPI) on MCs. Utilizing murine bone marrow-derived mast cells (BMMCs), we found that LPI did not cause degranulation, but slightly increased FcεRI-dependent ß-hexosaminidase release. However, LPI induced strong chemotaxis together with changes in LIM kinase (LIMK) and cofilin phosphorylation. LPI also promoted modifications to actin cytoskeleton dynamics that were detected by an increase in cell size and interruptions in the continuity of the cortical actin ring. The chemotaxis and cortical actin ring changes were dependent on GPR55 receptor activation, since the specific agonist O1602 mimicked the effects of LPI and the selective antagonist ML193 prevented them. The LPI and O1602-dependent stimulation of BMMC also led to VEGF, TNF, IL-1α, and IL-1ß mRNA accumulation, but, in contrast with chemotaxis-related processes, the effects on cytokine transcription were dependent on GPR55 and cannabinoid (CB) 2 receptors, since they were sensitive to ML193 and to the specific CB2 receptor antagonist AM630. Remarkably, GPR55-dependent BMMC chemotaxis was observed towards conditioned media from distinct mouse and human cancer cells. Our data suggest that LPI induces the chemotaxis of MCs and leads to cytokine production in MC in vitro with the differential participation of GPR55 and CB2 receptors. These effects could play a significant role in the recruitment of MCs to tumors and the production of MC-derived pro-angiogenic factors in the tumor microenvironment.

Digital and Analog Resistive Switching Behavior in Si-NCs Embedded in a Si/SiO2 Multilayer Structure for Neuromorphic Systems.

In this work, we report the digital and analog resistive-switching (RS) characteristics in a memristor based on silicon nanocrystals (Si-NCs) integrated into a complementary metal-oxide-semiconductor (MOS) structure. Si-NCs with a diameter of 5.48 ± 1.24 nm embedded in a SiO2/Si-NCs/SiO2 multilayer structure acts as an RS layer. These devices exhibit bipolar RS with an intermediate resistance step during SET and RESET processes, which is believed to lie in the Si-NCs layer acting as charge-trapping nodes. The endurance studies of about 70 DC cycles indicate an ON/OFF ratio of ~106 and a retention time larger than 104 s. Long-term potentiation (LTP, -2 V) and long-term depression (LTD, +4 V) are obtained by applying consecutive identical pulse voltages of 150 ms duration. The current value gradually increases/decreases (LTP/LTD) as the pulse number increases. Three consecutive identical pulses of -2 V/150 ms (LTP) separated by 5 and 15 min show that the last current value obtained at the end of each pulse train is kept, confirming an analog RS behavior. These characteristics provide a possible way to mimic biological synapse functions for applications in neuromorphic computing in Si-NCs-based CMOS structures.

Synthesis of (µ2,η3-allyl-η5-oxapentadienyl)diiron pentacarbonyl complexes, an unusual reaction product from η4-(vinylketene)Fe(CO)3 complexes: structure and electron density distribution analysis.

The synthesis of a series of ferrocenylvinylketenes as stable η4-[Fe(CO)3] complexes (3a-f) was successfully accomplished through the reaction of η2-[Fe(CO)4] complexes under mild carbonylation conditions. The reactivity of 3a-f under thermal conditions afforded the unexpected formation of a novel family of (µ2,η3-allyl-η5-oxapentadienyl)diiron pentacarbonyl complexes 5a-f proposed to be formed by a sequence metathesis-haptotropic rearrangement between the starting η4-vinylketene iron(0) complex 3 and a η4-vinylcarbene iron(0) complex trapped in situ after a reversible carbonylation process favored by the thermal conditions. An electron density distribution analysis (EDD) of 5e using high-resolution X-ray diffraction data in combination with the DFT framework was performed to understand the electronic communication between the two iron fragments.