Cost-effective screen printing approach for Ce/Nd-doped ZnAl2O4 films: tuning crystallinity induced by the substrate.

Near-infrared (NIR) emitting phosphors are currently receiving considerable attention owing to their high demand in various applications, such as light detection and ranging (LiDAR), short-range communications, security, biosensing and night vision lighting applications. The miniaturization of photonic components demands the integration of thin films into exploitable devices. In this context, NIR emitting ZnAl2O4:Ce/Nd films of hundreds of nanometer thickness are synthesized using a scalable and cost-efficient approach to screen printing. Cerium co-doping is responsible for the Nd emission in the NIR through energy transfer by exciting the films under UV excitation at around 360 nm. Through the proper design of ink, dense Nd/Ce doped ZnAl2O4 ceramic films were produced using polycrystalline alumina. The use of polycrystalline alumina substrates opens up new opportunities because this ceramic is a cheap and well-known substrate for optoelectronic packaging. During manufacturing, as a direct effect of predominant crystal growth over the polycrystalline alumina substrate, an increase in emission intensity is achieved. The results obtained by X-ray photoelectron (XPS) and X-ray absorption near edge spectroscopy (XANES) serve to determine the oxidation state of Ce. The findings of this study indicate that a higher concentration of Ce4+ promotes NIR emission. This study may contribute to a better understanding of film production processes of films based on the ZnAl2O4 matrix and guide future studies on films for NIR emitters.

Type II hiatal hernias: do they exist or are they actually parahiatal hernias?

BACKGROUND: Type II hiatal hernias (HH) are characterized by a portion of the gastric fundus located above the esophageal hiatus adjacent to the esophagus while the gastroesophageal junction (GEJ) remains fixed below the esophageal hiatus. This type of HH has been called the "true" paraesophageal hernia (PEH) because the fundus appears to the side of the esophagus. In our experience, Type II HHs are occasionally identified on radiographic testing, however they are rarely, if ever, confirmed intraoperatively. This led to our question: Does Type II HH exist? METHODS: We searched for evidence of type II HH in three locations: 1. Retrospective review of all first-time PEH repairs (excluding Type I HHs and re-operative cases) performed at the University of Washington Medical Center from 1994 to 2021; 2. Operative videos available on YouTube and WebSurg websites; and 3. Abstracts from the SAGES annual meetings from 2005 to 2021. RESULTS: We found no evidence of Type II HH in any of our three searches. We performed 846 PEH repairs: 760 Type III, 75 Type IV, and 11 parahiatal. Upon website video review, we found only one possible type II hernia, though it too was likely a para-hiatal hernia. No video or case presentations of a type II HH were identified within SAGES annual meeting abstracts. CONCLUSION: Type II HHs do not exist as they are currently defined. Although uncommon, parahiatal hernia can easily be misinterpreted as Type II HH. We should consider changing the hiatal hernia classification system to prevent ongoing clinical confusion.

The cytoplasmic microtubule array in Neurospora crassa depends on microtubule-organizing centers at spindle pole bodies and microtubule +end-depending pseudo-MTOCs at septa.

γ-Tubulin ring complexes (γ-TuRC) mediate nucleation and anchorage of microtubules (MTs) to microtubule organizing centers (MTOCs). In fungi, the spindle pole body (SPB) is the functional equivalent of the centrosome, which is the main MTOC. In addition, non-centrosomal MTOCs (ncMTOCs) contribute to MT formation in some fungi like Schizosaccharomyces pombe and Aspergillus nidulans. In A. nidulans, MTOCs are anchored at septa (sMTOC) and share components of the outer plaque of the SPB. Here we show that the Neurospora crassa SPB is embedded in the nuclear envelope, with the γ-TuRC targeting proteins PCP-1Pcp1/PcpA located at the inner plaque and APS-2Mto1/ApsB located at the outer plaque of the SPB. PCP-1 was a specific component of nuclear MTOCs, while APS-2 was also present at the septal pore. Although γ-tubulin was only detected at the nucleus, spontaneous MT nucleation occurred in the apical and subapical cytoplasm during recovery from benomyl-induced MT depolymerization experiments. There was no evidence for MT nucleation at septa. However, without benomyl treatment MT plus-ends were organized in the septal pore through MTB-3EB1. Those septal MT plus ends polymerized MTs from septa in interphase cells Thus we conclude that the SPB is the only MT nucleation site in N. crassa, but the septal pore aids the MT network arrangement through the anchorage of the MT plus-ends through a pseudo-MTOC.

Phenytoin promotes the proliferation of oligodendrocytes and enhances the expression of myelin basic protein in the corpus callosum of mice demyelinated by cuprizone.

Oligodendrocyte loss and myelin sheet destruction are crucial characteristics of demyelinating diseases. Phenytoin promotes the proliferation of endogenous neural precursor cells in the ventricular-subventricular zone in the postnatal brain that help restore the oligodendroglial population. This study aimed to evaluate whether phenytoin promotes myelin recovery of the corpus callosum of demyelinated adult mice. CD1 male mice were exposed to a demyelinating agent (0.2% cuprizone) for 8 weeks. We assembled two groups: the phenytoin-treated group and the control-vehicle group. The treated group received oral phenytoin (10 mg/kg) for 4 weeks. We quantified the number of Olig2 + and NG2 + oligodendrocyte precursor cells (OPCs), Rip + oligodendrocytes, the expression level of myelin basic protein (MBP), and the muscle strength and motor coordination. The oligodendroglial lineage (Olig2 + cells, NG2 + cells, and RIP + cells) significantly increases by the phenytoin administration when compared to the control-vehicle group. The phenytoin-treated group also showed an increased expression of MBP in the corpus callosum and better functional scores in the horizontal bar test. These findings suggest that phenytoin stimulates the proliferation of OPCs, re-establishes the oligodendroglial population, promotes myelin recovery in the corpus callosum, and improves motor coordination and muscle strength.

[Profile of antimicrobial resistance in isolates of Staphylococcus spp. obtained from bovine milk in Colombia]. / Perfil de resistencia antimicrobiana en aislamientos de Staphylococcus spp. obtenidos de leche bovina en Colombia.

Staphylococcus spp. is one of the pathogens that cause bovine mastitis and may present multiple resistance to different antimicrobial groups. The aim of this study was to phenotypically identify Staphylococcus spp. isolates obtained from bovine milk and to characterize their antimicrobial resistance profile. The 101 strains were classified by phenotypic tests, their resistance to oxacillin, cefoxitin, penicillin, ampicillin, tetracycline, kanamycin, sulfamethoxazole / trimethoprim, clindamycin and erythromycin was determined by the Kirby-Bauer technique and the presence of resistance genes by PCR. A total of 65 strains was S. aureus and 36 strains were coagulase-negative staphylococci (CoNS). We found different patterns of resistance to antibiotics evaluated in strains of S. aureus and CoNS, only the resistance to ampicillin was found associated with the species (p<0.005). In the 101 strains, the mecA gene was detected in 27%, aph(3')-IIIa in 75.2%, aac(6')/aph(2")-3 in 47.4%, ant(4')-Ia in 32.7%, tetM in 63% and tetK in 43.6%; however, no association was found with the resistance to penicillin, ampicillin, cefoxitin, kanamycin and tetracycline, respectively (p>0.05). On the other hand, the blaZ gene was found in 59.4% of the 101 strains and the ermCgene in 62.3%, which was associated with resistance to ß-lactams and macrolides, respectively (p<0.001). In this study, antimicrobial multiresistance was found in S. aureus and CoNS strains. This finding impacts on the dairy industry, representing a risk to public health.

Circulating miR-146a, miR-34a and miR-375 in type 2 diabetes patients, pre-diabetic and normal-glycaemic individuals in relation to ß-cell function, insulin resistance and metabolic parameters.

The pathogenesis of type 2 diabetes (T2D) is associated with a progressive loss of pancreatic ß-cell mass. It is known that miR-146a, miR-34a, and miR-375 are involved in ß-cell functionality. In this work, we evaluated the levels of these miRNAs in normal-glycaemic individuals, pre-diabetic, and T2D patients in relation to ß-cell functionality, insulin resistance, and metabolic parameters. The relative expression of the miRNAs was evaluated in serum samples by real-time polymerase chain reaction. In a principal component analysis, we observed that T2D patients and pre-diabetic individuals were not associated with ß-cell functionality. However, in a correlation matrix analysis, we detected that miR-34a was related to miR-146a and insulin resistance. The relative expression of miR-375 was correlated with cholesterol and low-density lipoprotein levels. A decrease of ß-cell function in pre-diabetic individuals and T2D patients was observed. The insulin resistance was higher in pre-diabetic individuals and T2D patients. The relative expression of miR-146a in pre-diabetic individuals, T2D patients with insulin treatment, and T2D patients with nephropathy and diabetic foot was decreased. In addition, miR-34a was increased in T2D patients who were overweight and obese. The relative expression of miR-375 was increased in T2D patients with poor glycaemic control, while a decrease was seen in T2D patients with nephropathy and diabetic foot. Circulating miR-375, miR-34a, and miR-146a were not associated with ß-cell functionality, but their expression was differentially affected by glycaemia, obesity, insulin treatment, and the presence of nephropathy and diabetic foot.

Identification of Brucella abortus biovar 4 of bovine origin in Colombia.

The objective of this study was to identify twelve Brucella abortus isolates of bovine origin from the department of Nariño in Colombia up to the biovar level. These isolates are included in the collection of the Germplasm Bank of Microorganisms of Animal Health Interest - Bacteria and Virus (BGSA-BV). The identification was carried out through conventional methods such as macro and microscopic morphological descriptions, enzymatic activity, biochemical profile, substrate use and sensitivity to dyes. Complementary genotypic characterization was carried out using multiplex PCR for B. abortus, Brucella melitensis, Brucella ovis, and Brucella suis-Erytritol (AMOS-ERY-PCR), RFLP-IS711, by southern blot hybridization, as well as by the multiple locus variable number of tandem repeat analysis (MLVA) using the ery gene and the insertion sequence IS711 and variable number of tandem repeats (VNTR) as molecular markers. The results of the phenotypic and molecular characterization allowed to identify twelve isolates as B. abortus biovar 4 as well as to differentiate field from vaccine strains. This is the first study on the phenotypic and molecular identification of B. abortus isolates in Colombia. It was concluded that the phenotypic and molecular identification of twelve isolates as B. abortus biovar 4 could be achieved using conventional and molecular techniques with enough resolution power. The identification of these isolates to the biovar level in taxonomic and epidemiological terms will allow the use of this genetic resource as reference strains in future research. This finding constitutes the basis for identifying biotypes not previously reported in the country that might be useful to support brucellosis survey programs in Colombia.

Environmental noise exposure modifies astrocyte morphology in hippocampus of young male rats.

BACKGROUND: Chronic exposure to noise induces changes on the central nervous system of exposed animals. Those changes affect not only the auditory system but also other structures indirectly related to audition. The hippocampus of young animals represents a potential target for these effects because of its essential role in individuals' adaptation to environmental challenges. OBJECTIVE: The aim of the present study was to evaluate hippocampus vulnerability, assessing astrocytic morphology in an experimental model of environmental noise (EN) applied to rats in pre-pubescent stage. MATERIALS AND METHODS: Weaned Wistar male rats were subjected to EN adapted to the rats' audiogram for 15 days, 24 h daily. Once completed, plasmatic corticosterone (CORT) concentration was quantified, and immunohistochemistry for glial fibrillary acidic protein was taken in hippocampal DG, CA3, and CA1 subareas. Immunopositive cells and astrocyte arborizations were counted and compared between groups. RESULTS: The rats subjected to noise exhibited enlarged length of astrocytes arborizations in all hippocampal subareas. Those changes were accompanied by a marked rise in serum CORT levels. CONCLUSIONS: These findings confirm hippocampal vulnerability to EN and suggest that glial cells may play an important role in the adaptation of developing the participants to noise exposure.

Phenytoin enhances the phosphorylation of epidermal growth factor receptor and fibroblast growth factor receptor in the subventricular zone and promotes the proliferation of neural precursor cells and oligodendrocyte differentiation.

Phenytoin is a widely used antiepileptic drug that induces cell proliferation in several tissues, such as heart, bone, skin, oral mucosa and neural precursors. Some of these effects are mediated via fibroblast growth factor receptor (FGFR) and epidermal growth factor receptor (EGFR). These receptors are strongly expressed in the adult ventricular-subventricular zone (V-SVZ), the main neurogenic niche in the adult brain. The aim of this study was to determine the cell lineage and cell fate of V-SVZ neural progenitors expanded by phenytoin, as well as the effects of this drug on EGFR/FGFR phosphorylation. Male BALB/C mice received 10 mg/kg phenytoin by oral cannula for 30 days. We analysed the proliferation of V-SVZ neural progenitors by immunohistochemistry and western blot. Our findings indicate that phenytoin enhanced twofold the phosphorylation of EGFR and FGFR in the V-SVZ, increased the number of bromodeoxyuridine (BrdU)+/Sox2+ and BrdU+/doublecortin+ cells in the V-SVZ, and expanded the population of Olig2-expressing cells around the lateral ventricles. After phenytoin removal, a large number of BrdU+/Receptor interacting protein (RIP)+ cells were observed in the olfactory bulb. In conclusion, phenytoin enhanced the phosphorylation of FGFR and EGFR, and promoted the expression of neural precursor markers in the V-SVZ. In parallel, the number of oligodendrocytes increased significantly after phenytoin removal.

Neural restrictive silencer factor and choline acetyltransferase expression in cerebral tissue of Alzheimer's Disease patients: A pilot study.

Decreased Choline Acetyltransferase (ChAT) brain level is one of the main biochemical disorders in Alzheimer's Disease (AD). In rodents, recent data show that the CHAT gene can be regulated by a neural restrictive silencer factor (NRSF). The aim of the present work was to evaluate the gene and protein expression of CHAT and NRSF in frontal, temporal, entorhinal and parietal cortices of AD patient brains. Four brains from patients with AD and four brains from subjects without dementia were studied. Cerebral tissues were obtained and processed by the guanidine isothiocyanate method for RNA extraction. CHAT and NRSF gene and protein expression were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. CHAT gene expression levels were 39% lower in AD patients as compared to the control group (p < 0.05, U test). ChAT protein levels were reduced by 17% (p = 0.02, U test). NRSF gene expression levels were 86% higher in the AD group (p = 0.001, U test) as compared to the control group. In the AD subjects, the NRSF protein levels were 57% higher (p > 0.05, U test) than in the control subjects. These findings suggest for the first time that in the brain of AD patients high NRSF protein levels are related to low CHAT gene expression levels.

Management of Recurrent Paraesophageal Hernia.

Introduction: Recurrent paraesophageal hernias (rPEH) represent a clinical and surgical challenge. Even with a relatively high incidence, most of them are minimally symptomatic, and the need for reoperation is low. For those patients who are candidates for surgery, laparoscopic revision is a feasible and safe technique although there are other treatment options available. Methods: This article provides an overview of the definition, mechanisms of recurrence, epidemiology, clinical presentation, and indications for treatment of rPEH, as well as an overview of the surgical management options and a description of the technical principles of the repair and/or resection. Results: Surgeons should consider multiple factors when deciding the appropriate treatment of patients with rPEH, and all of them require a complete and comprehensive evaluation. The surgical options need to be individualized and include a redo PEH repair and revisional fundoplication, a partial or total gastrectomy with Roux-en-Y reconstruction, or an esophagectomy. There are key steps during the surgical repair that contribute to a successful operation and also auxiliary techniques that can improve postoperative outcomes. After laparoscopic redo most patients have improvement of their symptoms and an acceptable rate of perioperative complications when they are performed by experienced foregut surgeons. In obese patients with rPEH, bariatric surgery can be the best treatment option. Conclusions: Laparoscopic reoperative management should be considered in symptomatic patients who are not controlled with maximal nonoperative therapy, after a thorough work-up and appropriate counseling. In cases with multiple hernia repairs, it is important to consider alternative operations.

Is It Possible to Measure the Role of the Bystander and the Victim of Bullying in Children? Construct Validity of Two Brief Pictorial Scales With IRT and CFA Models.

The study's objective was to develop and validate the psychometric properties of two brief pictorial scales to evaluate the roles of bystanders and victims of bullying. A sample of 910 students was considered (49.6%, boys; 50.4%, girls) between the ages of 7 and 13 (M = 10, SD = 1.4). Both instruments present nine pictorial items representing two dimensions: physical bullying (items 1 to 4) and psychological bullying (items 5 to 9). An additional measure of anxiety was used to assess convergent validity. The Confirmatory Factorial Analysis shows that the two-dimensional oblique model, physical bullying and psychological bullying, presents a better fit to the bystander scale data (RMSEA = .040; CFI = .984; SRMR = .033) and in the victim scale (RMSEA = .051; CFI = .978; SRMR = .040) in comparison to other competitor models. From the perspective of the Item Response Theory (IRT), it was found that the items adequately discriminate the levels of the latent variable; therefore, items 1 (physical bullying) and 7 (psychological bullying) are the most accurate on the bystander scale, and items 3 (physical bullying) and 7 (psychological bullying), on the victim scale. It was also found that the degree of difficulty on both scales is lower for the psychological bullying dimension than for the physical bullying dimension. Both instruments demonstrated good psychometric properties; therefore, they can detect school bullying in classrooms.

Gender and Leadership Positions in Spanish Dentistry.

Dentists in Spain reached equal gender representation in 2012 and the number of female dentists has continued to grow (until 57.3% in 2020). This study aims to increase evidence about the gender distribution on the high responsibility positions and opinion leaders of the dental profession and academia. Composition of the executive comities of the main dental institutions of Spain (regional professional associations, national dental association, and scientific societies), members of the Faculty of Dentistry of the University of Granada in 2020 and speakers of the main dental congresses of 2019 (due to the lack of congress in 2020) were recorded and analyzed by genders using chi-squared test (P < .05). Mean representation of female dentists in executive committees of professional associations was 35.6%. More than 70% of presidents and vice-presidents of professional colleges and more than 60% of these positions in scientific societies were occupied by male dentists. None of dental congresses of 2019 reached equal gender participation, being 81.3% of lecturers presenting on main auditoriums male dentists. Although dental workforce in Spain is slightly overrepresented by females, leadership positions and figures among Spanish dentists doesn't seem to reflect the gender distribution of the collective. There is a lack of women occupying high-level positions in dentistry that proves the existence of the so-called "glass ceiling effect" on the profession. Further studies about sociodemographic aspects of dental workforce are needed to develop evidence-based policies for the collective.

Therapeutic Approaches for ADHD by Developmental Stage and Clinical Presentation.

Attention Deficit Hyperactivity Disorder is a neurodevelopmental disorder with three presentations: inattentive, hyperactive/impulsive and combined. These may represent an independent disease entity. Therefore, the therapeutic approach must be focused on their neurobiological, psychological and social characteristics. To date, there is no comprehensive analysis of the efficacy of different treatments for each presentation of ADHD and each stage of development. This is as narrative overview of scientific papers that summarize the most recent findings and identify the most effective pharmacological and psychosocial treatments by ADHD presentation and age range. Evidence suggests that methylphenidate is the safest and most effective drug for the clinical management of children, adolescents and adults. Atomoxetine is effective in preschoolers and maintains similar efficacy to methylphenidate in adults, whereas guanfacine has proven to be an effective monotherapy for adults and is a worthy adjuvant for the management of cognitive symptoms. The psychosocial treatments with the best results in preschoolers are behavioral interventions that include training of primary caregivers. In adolescents, the combination of cognitive and cognitive-behavioral therapies has shown the best results, whereas cognitive-behavioral interventions are the most effective in adults. Pharmacological and psychosocial treatments must be adjusted to the ADHD presentation and its neurocognitive characteristics through the patient's development.

Role of c-miR-21, c-miR-126, Redox Status, and Inflammatory Conditions as Potential Predictors of Vascular Damage in T2DM Patients.

The development of type 2 diabetes mellitus (T2DM) vascular complications (VCs) is associated with oxidative stress and chronic inflammation and can result in endothelial dysfunctions. Circulating microRNAs play an important role in epigenetic regulation of the etiology of T2DM. We studied 30 healthy volunteers, 26 T2DM patients with no complications, and 26 T2DM patients with VCs, to look for new biomarkers indicating a risk of developing VCs in T2DM patients. Peripheral blood samples were used to determine redox state, by measuring the endogenous antioxidant defense system (superoxide dismutase, SOD; catalase, CAT; glutathione reductase, GRd; glutathione peroxidase, GPx; and glucose-6-phosphate dehydrogenase, G6DP) and markers of oxidative damage (advanced oxidation protein products, AOPP; lipid peroxidation, LPO). Additionally, inflammatory marker levels (IL-1, IL-6, IL-18, and TNF-α), c-miR-21, and c-miR-126 expression were analyzed. T2DM patients showed the highest oxidative damage with increased GSSG/GSH ratios, LPO, and AOPP levels. In both diabetic groups, we found that diminished SOD activity was accompanied by increased CAT and decreased GRd and G6PD activities. Diabetic patients presented with increased relative expression of c-miR-21 and decreased relative expression of c-miR-126. Overall, c-miR-21, SOD, CAT, and IL-6 had high predictive values for diabetes diagnoses. Finally, our data demonstrated that IL-6 exhibited predictive value for VC development in the studied population. Moreover, c-miR-21 and c-miR-126, along with GPx and AOPP levels, should be considered possible markers for VC development in future studies.

A gender- based approach to the current situation of Spanish dentists.

BACKGROUND: To determine the perception of Spanish dentists about the situation of the profession nowadays and how the changes occurred in dental workforce (in number and gender of the past twenty years) have affected their personal and professional lives, under a gender-based approach. MATERIAL AND METHODS: An online survey comprising of 51 opinion and socio-economic questions, divided into 9 sections of different topics, which was administered between the members of 13 professional associations. Chi-squared tests were calculated (p<0.05). RESULTS: Valid responses were received from 422 participants with a mean age of 41 years old and 66% of female dentists. Most dentists considered their selves in a "good" position, however, 72.3% of them said the profession "has had worsened". Opinions significantly differed between women and men in gender equity and the pay gap between them could be observed (29.4% of males earned more of 4000 euros a month, while only 15.1% female dentists did). Also, 49.5% of female dentists felt underrepresented in the highest association of Spanish dentists (General Council of Dentist - Consejo General de Dentistas) and 38.4% declared they have had suffered verbal violence coming from patients repeatedly. CONCLUSIONS: A generally negative perception of dentists' work quality was found among respondents. Also, opinions between males and females differed in important aspects of professional development. Further research projects are needed to have growing evidence on problems and disparities in the dental workforce which would help the institutions to make improvement actions. Key words:Dentists, Health Workforce, Survey, Gender, Spain.

A one-arm surgical trial of obstructive sleep apnea (OSA) patients before and 12 months after Bilateral Internal Ramus Distraction of the mandible (BIRD).

BACKGROUND: An innovative approach for the primary and definitive treatment of obstructive sleep apnea (OSA) in adult patients is presented: Bilateral Internal Ramus Distraction of the mandible (BIRD), which is a slow, progressive and more stable procedure to advance the mandibular bone. This study investigated whether this surgical approach is useful to cure OSA. METHODS: Study design was of an interventional (surgical) one-arm trial of OSA patients assessed before and 12 months after BIRD. All patients were evaluated by pre- and post-operative polysomnography and three-dimensional scans. The amount of skeletal advancement, percentage of upper airway volume increase and postoperative value of mandibular occlusal plane were the predictor variables. Changes in the apnoea-hypopnoea index (AHI), oxygen desaturation index (ODI), and percentage of time with saturation under 90% (TC90) were the main outcome variables. FINDINGS: Thirty-two subjects with a mean ± SD age of 41.9 ± 13.3 years and 87.5% male were included, and they were followed-up 32 ± 14.2 months. AHI was 47.9 ± 23.1 per hour before surgery and the Epworth Sleepiness Scale (ESS) was 13.4 ± 4.4. Postoperative AHI was 4.8 ± 5.6 per hour 12 months after surgery (P < 0.001), with 81.2% of the patients considered cured (AHI<5) and 18.8% suffering from a mild-to-moderate residual OSA. ESS decreased to 1.9 ± 1.8 at the end of the surgical treatment (P < 0.001). 3D changes revealed an upper airway volume increase of 188.4% ± 73.5% (P < 0.001). INTERPRETATION: Lengthening the mandibular ramus by distraction osteogenesis to cure OSA appears to be more effective and safer when compared to other surgical protocols, especially in very severe cases with initial AHI>50/h. Titration of the mandibular advancement weekly using respiratory polygraphy allows better healing control and customization of the skeletal advancement, enhancing the aesthetic result.

Thermal Transport and Thermoelectric Effect in Composites of Alumina and Graphene-Augmented Alumina Nanofibers.

The remarkable tunability of 2D carbon structures combined with their non-toxicity renders them interesting candidates for thermoelectric applications. Despite some limitations related to their high thermal conductivity and low Seebeck coefficients, several other unique properties of the graphene-like structures could out-weight these weaknesses in some applications. In this study, hybrid structures of alumina ceramics and graphene encapsulated alumina nanofibers are processed by spark plasma sintering to exploit advantages of thermoelectric properties of graphene and high stiffness of alumina. The paper focuses on thermal and electronic transport properties of the systems with varying content of nanofillers (1-25 wt.%) and demonstrates an increase of the Seebeck coefficient and a reduction of the thermal conductivity with an increase in filler content. As a result, the highest thermoelectric figure of merit is achieved in a sample with 25 wt.% of the fillers corresponding to ~3 wt.% of graphene content. The graphene encapsulated nanofibrous fillers, thus, show promising potential for thermoelectric material designs by tuning their properties via carrier density modification and Fermi engineering through doping.

Functionally Graded Tunable Microwave Absorber with Graphene-Augmented Alumina Nanofibers.

Graphene is currently attracting attention for radiation absorption particularly at gigahertz and terahertz frequencies. In this work, composites formed by graphene-augmented γ-Al2O3 nanofibers embedded into the α-Al2O3 matrix are tested for X-band absorption efficiency. Composites with 15 and 25 wt % of graphene fillers with shielding effectiveness (SE) of 38 and 45 dB, respectively, show a high reflection coefficient, while around the electrical percolation threshold (∼1 wt %), an SE of 10 dB was achieved. Furthermore, based on the dielectric data obtained for varying fractions of graphene-/γ-Al2O3-added fillers, a functionally graded multilayer is constructed to maximize the device efficiency. The fabricated multilayer offers the highest absorption efficiency of 99.99% at ∼9.6 GHz and a full X-band absorption of >90% employing five lossy layers of 1-3-5-15 and 25 wt % of graphene/γ-Al2O3 fillers. The results prove a remarkable potential of the fillers and various multilayer designs for broad-band and frequency-specific microwave absorbers.

Biopsychological correlates of repetitive and restricted behaviors in autism spectrum disorders.

BACKGROUND: Autism Spectrum Disorder (ASD) is considered a neurodevelopmental condition that is characterized by alterations in social interaction and communication, as well as patterns of restrictive and repetitive behaviors (RRBs). RRBs are defined as broad behaviors that comprise stereotypies, insistence on sameness, and attachment to objects or routines. RRBs can be divided into lower-level behaviors (motor, sensory, and object-manipulation behaviors) and higher-level behaviors (restrictive interests, insistence on sameness, and repetitive language). According to the DSM-5, the grade of severity in ASD partially depends on the frequency of RRBs and their consequences for disrupting the life of patients, affecting their adaptive skills, and increasing the need for parental support. METHODS: We conducted a systematic review to examine the biopsychological correlates of the symptomatic domains of RRBs according to the type of RRBs (lower- or higher-level). We searched for articles from the National Library of Medicine (PubMed) using the terms: autism spectrum disorders, ASD, and autism-related to executive functions, inhibitory control, inflexibility, cognitive flexibility, hyper or hypo connectivity, and behavioral approaches. For describing the pathophysiological mechanism of ASD, we also included animal models and followed PRISMA guidelines. RESULTS: One hundred and thirty-one articles were analyzed to explain the etiology, continuance, and clinical evolution of these behaviors observed in ASD patients throughout life. CONCLUSIONS: Biopsychological correlates involved in the origin of RRBs include alterations in a) neurotransmission system, b) brain volume, c) inadequate levels of growth factors, d) hypo- or hyper-neural connectivity, e) impairments in behavioral inhibition, cognitive flexibility, and monitoring and f) non-stimulating environments. Understanding these lower- and higher-level of RRBs can help professionals to improve or design novel therapeutic strategies.