Synthesis and characterization of La_0.8Sr_1.2Co_0.5M_0.5O_4-? (M=Fe, Mn)

The M4+-containing K2NiF4-type phases La0.8Sr1.2Co0.5Fe0.5O4 and La0.8Sr1.2Co0.5Mn0.5O4 have been synthesized by a sol-gel procedure and characterized by X-ray powder diffraction, thermal analysis, neutron powder diffraction and Mössbauer spectroscopy. Oxide ion vacancies are created in these materials via reduction of M4+ to M3+ and of Co3+ to Co2+. The vacancies are confined to the equatorial planes of the K2NiF4-type structure. A partial reduction of Mn3+ to Mn2+ also occurs to achieve the oxygen stoichiometry in La0.8Sr1.2Co0.5Mn0.5O3.6. La0.8Sr1.2Co0.5Fe0.5O3.65 contains Co2+ and Fe3+ ions which interact antiferromagnetically and result in noncollinear magnetic order consistent with the tetragonal symmetry. Competing ferromagnetic and antiferromagnetic interactions in La0.8Sr1.2Co0.5Fe0.5O4, La0.8Sr1.2Co0.5Mn0.5O4 and La0.8Sr1.2Co0.5Mn0.5O3.6 induce spin glass properties in these phases

Thermoeconomic approach for the analysis of control system of energy plants

In this paper a thermoeconomic approach is applied to the dynamic model of a Power System in order to investigate the effects of the control system on the primary energy consumption and on the economic costs of the product. To achieve this objective, various control strategies are compared when variations of the operation condition, due to some internal or external causes, are produced. These variations cause the intervention of the control system, which rearranges the operating condition in order to have the controlled quantities within acceptable ranges. Generally the plant efficiency changes, depending on the selected strategy. A microturbine is considered as the case study. The analysis here proposed allows one to quantify the effect of the control on the performance variation of the components. The approach associates an exergetic cost and a thermoeconomic cost to the control system operation, which expresses the additional resource (primary energy and economic resources) consumptions that may be associated to the control. The impact on the initial and final steady states as well as the transient evolution are considered. This can be usefully applied to improve energy system operation acting on the control system, both in the off-design steady states and transient operations. In the particular application considered in this paper, reductions of about 8% in fuel consumption and 5% in the total costs are achieved. Concerning transient operation, it is shown that the control system can produce large variation in the operation cost

Skin flora: Differences Between People Affected by Albinism and Those with Normally Pigmented Skin in Northern Tanzania - Cross Sectional Study.

Skin flora varies from one site of the body to another. Individual's health, age and gender determine the type and the density of skin flora. A 1  cm² of the skin on the sternum was rubbed with sterile cotton swab socked in 0.9% normal saline and plated on blood agar. This was cultured at 35 °C. The bacteria were identified by culturing on MacConkey agar, coagulase test, catalase test and gram staining. Swabs were obtained from 66 individuals affected by albinism and 31 individuals with normal skin pigmentation. Those with normal skin were either relatives or staying with the individuals affected by albinism who were recruited for the study. The mean age of the 97 recruited individuals was 30.6 (SD ± 14.9) years. The mean of the colony forming units was 1580.5 per cm2. Those affected by albinism had a significantly higher mean colony forming units (1680  CFU per cm²) as compared with 453.5  CFU per cm² in those with normally pigmented skin (p = 0.023). The skin type and the severity of sun- damaged skin was significantly associated with a higher number of colony forming units (p = 0.038). Individuals affected by albinism have a higher number of colony forming units which is associated with sun- damaged skin

Cortical–subcortical interactions in hypersomnia disorders: Mechanisms underlying cognitive and behavioral aspects of the sleep–wake cycle

Subcortical circuits mediating sleep–wake functions have been well characterized in animal models, and corroborated by more recent human studies. Disruptions in these circuits have been identified in hypersomnia disorders (HDs) such as narcolepsy and Kleine–Levin Syndrome, as well as in neurodegenerative disorders expressing excessive daytime sleepiness. However, the behavioral expression of sleep–wake functions is not a simple on-or-off state determined by subcortical circuits, but encompasses a complex range of behaviors determined by the interaction between cortical networks and subcortical circuits. While conceived as disorders of sleep, HDs are equally disorders of wake, representing a fundamental instability in neural state characterized by lapses of alertness during wake. These episodic lapses in alertness and wakefulness are also frequently seen in neurodegenerative disorders where electroencephalogram demonstrates abnormal function in cortical regions associated with cognitive fluctuations (CFs). Moreover, functional connectivity MRI shows instability of cortical networks in individuals with CFs. We propose that the inability to stabilize neural state due to disruptions in the sleep–wake control networks is common to the sleep and cognitive dysfunctions seen in hypersomnia and neurodegenerative disorders

Simple Clinical Screening Underestimates Malnutrition in Surgical Patients with Inflammatory Bowel Disease-An ACS NSQIP Analysis.

The present large scale study aimed to assess the prevalence and consequences of malnutrition, based on clinical assessment (body mass index and preoperative weight loss) and severe hypoalbuminemia (<3.1 g/L), in a representative US cohort undergoing IBD surgery. The American College of Surgeons National Quality improvement program (ACS-NSQIP) Public User Files (PUF) between 2005 and 2018 were assessed. A total of 25,431 patients were identified. Of those, 6560 (25.8%) patients had severe hypoalbuminemia, 380 (1.5%) patients met ESPEN 2 criteria (≥10% weight loss over 6 months PLUS BMI < 20 kg/m <sup>2</sup> in patients <70 years OR BMI < 22 kg/m <sup>2</sup> in patients ≥70 years), and 671 (2.6%) patients met both criteria (severe hypoalbuminemia and ESPEN 2). Patients who presented with malnutrition according to any of the three definitions had higher rates of overall, minor, major, surgical, and medical complications, longer LOS, higher mortality and higher rates of readmission and reoperation. The simple clinical assessment of malnutrition based on BMI and weight loss only, considerably underestimates its true prevalence of up to 50% in surgical IBD patients and calls for dedicated nutritional assessment

Test Anxiety and Relaxation Training in Third-Grade Students

As testing becomes an achievement marker for elementary school children, test anxiety would naturally follow for these children. This study looks at test anxiety in third grade students, as well as relaxation training as a treatment modality to deal with that anxiety. One hundred and four third grade students participated in this study. Those students that received relaxation training experienced less test anxiety after the treatment. Students in the control group showed no changes in test anxiety. The use of relaxation training among third grade students may be a beneficial method for teachers to reduce anxiety in their students

Self-Similar Dynamical Relaxation of Dark Matter Halos in an Expanding Universe

We investigate the structure of cold dark matter halos using advanced models of spherical collapse and accretion in an expanding Universe. These base on solving time-dependent equations for the moments of the phase-space distribution function in the fluid approximation; our approach includes non-radial random motions, and most importantly, an advanced treatment of both dynamical relaxation effects that takes place in the infalling matter: phase-mixing associated to shell crossing, and collective collisions related to physical clumpiness. We find self-similar solutions for the spherically-averaged profiles of mass density rho(r), pseudo phase-space density Q(r) and anisotropy parameter beta(r). These profiles agree with the outcomes of state-of-the-art N-body simulations in the radial range currently probed by the latter; at smaller radii, we provide specific predictions. In the perspective provided by our self-similar solutions we link the halo structure to its two-stage growth history, and propose the following picture. During the early fast collapse of the inner region dominated by a few merging clumps, efficient dynamical relaxation plays a key role in producing a closely universal mass density and pseudo phase-space density profiles; in particular, these are found to depend only weakly on the detailed shape of the initial perturbation and the related collapse times. The subsequent inside-out growth of the outer regions feeds on the slow accretion of many small clumps and diffuse matter; thus the outskirts are only mildly affected by dynamical relaxation but are more sensitive to asymmetries and cosmological variance.Comment: 31 pages, 16 figures. Typos corrected. Accepted by Ap

Trends of complications and innovative techniques' utilization for colectomies in the United States.

Despite an increasing trend towards utilization of minimally invasive approaches (MIS), results regarding their safety profile are contradictory. All patients who underwent elective colectomy for any underlying disease with an identifiable operative approach available from the targeted colectomy files of the ACS-NSQIP PUFs 2013 to 2018 were included. The trend of utilization and complication rates of the different operative approaches (open, laparoscopic, robotic) were assessed during the inclusion period. Furthermore, overall, surgical, and medical complications were compared between the three approaches. The study cohort included 78,987 patients. Of them, 12,335 (15.6%) patients underwent open, 57,874 (73.3%) laparoscopic, and 8,778 (11.1%) robotic surgery. There was an increasing trend towards the utilization of robotic surgery (2.5% increase per year) at the expense of the other approaches. With the increasing trend toward the utilization of the robotic approach, a decreasing trend in overall and surgical complications and length of stay was observed. After adjusting for the baseline confounders, robotic surgery was associated with shorter length of stay, lower rate of overall (OR 0.397; p < 0.05 compared to open and OR: 0.763; p < 0.05 compared to laparoscopy) and surgical complications (OR: 0.464; p < 0.05 compared to open and OR: 0.734; p < 0.05 compared to laparoscopy). This study revealed an increasing trend toward the utilization of MIS for elective colectomy in the US. Robotic surgery was associated with a decreasing trend in overall and surgical morbidity and length of stay

Symptomatic Uncomplicated Diverticular Disease (SUDD): Practical Guidance and Challenges for Clinical Management

Symptomatic Uncomplicated Diverticular Disease (SUDD) is a syndrome within the diverticular disease spectrum, characterized by local abdominal pain with bowel movement changes but without systemic inflammation. This narrative review reports current knowledge, delivers practical guidance, and reveals challenges for the clinical management of SUDD. A broad and common consensus on the definition of SUDD is still needed. However, it is mainly considered a chronic condition that impairs quality of life (QoL) and is characterized by persistent left lower quadrant abdominal pain with bowel movement changes (eg, diarrhea) and low-grade inflammation (eg, elevated calprotectin) but without systemic inflammation. Age, genetic predisposition, obesity, physical inactivity, low-fiber diet, and smoking are considered risk factors. The pathogenesis of SUDD is not entirely clarified. It seems to result from an interaction between fecal microbiota alterations, neuro-immune enteric interactions, and muscular system dysfunction associated with a low-grade and local inflammatory state. At diagnosis, it is essential to assess baseline clinical and Quality of Life (QoL) scores to evaluate treatment efficacy and, ideally, to enroll patients in cohort studies, clinical trials, or registries. SUDD treatments aim to improve symptoms and QoL, prevent recurrence, and avoid disease progression and complications. An overall healthy lifestyle – physical activity and a high-fiber diet, with a focus on whole grains, fruits, and vegetables – is encouraged. Probiotics could effectively reduce symptoms in patients with SUDD, but their utility is missing adequate evidence. Using Rifaximin plus fiber and Mesalazine offers potential in controlling symptoms in patients with SUDD and might prevent acute diverticulitis. Surgery could be considered in patients with medical treatment failure and persistently impaired QoL. Still, studies with well-defined diagnostic criteria for SUDD that evaluate the safety, QoL, effectiveness, and cost-effectiveness of these interventions using standard scores and comparable outcomes are needed

Oral Antibiotics Bowel Preparation Without Mechanical Preparation For Minimally Invasive Colorectal Surgeries: Current Practice And Future Prospects.

The efficacy of preoperative oral antibiotics alone compared to mechanical bowel preparation and oral antibiotics in minimally invasive surgery is still a matter of ongoing debate. This study aimed to assess the trend of surgical site infection rates in parallel to the utilization of bowel preparation modality over time for minimally invasive surgery colorectal surgeries in the United States. Retrospective analysis. The American College of Surgeons National Surgical Quality Improvement Program database. Adult patients who underwent elective colorectal surgery and reported bowel preparation modality. The trends and compare surgical site infection rates for mutually exclusive groups according to the underlying disease (colorectal cancer, inflammatory bowel disease, and diverticular disease) who underwent bowel preparation using oral antibiotics or combined mechanical bowel preparation and oral antibiotics. Patients who had rectal surgery were analyzed separately. A total of 30,939 patients were included. Of them, 12,417 (40%) had rectal resections. Over the seven-year study period, mechanical bowel preparation and oral antibiotics utilization has increased from 29.3% in 2012 to 64.0% in 2018; p<0.0001 at the expense of no preparation and mechanical bowel preparation alone. Similarly, oral antibiotics utilization has increased from 2.3% in 2012 to 5.5% in 2018; p<0.0001. For colon cancer patients, patients who had oral antibiotics alone had higher superficial surgical site infection rates compared to patients who had combined mechanical bowel preparation and oral antibiotics (1.9% vs. 1.1%; p=0.043). Superficial, deep and organ space surgical site infection rates were similar for all other comparative colon surgery groups (cancer, inflammatory bowel disease, and diverticular disease). Patients with rectal cancer who had oral antibiotics had higher rates of deep surgical site infection (0.9% vs. 0.1%; p=0.004). However, superficial, deep and organ space surgical site infection rates were similar for all other comparative rectal surgery groups. Retrospective nature of the analysis. This study revealed widespread adoption of mechanical bowel preparation and oral antibiotics mechanical bowel preparation and oral antibiotics and increased adoption of oral antibiotics over the study period. Surgical site infection rates appear to be similar from a clinical relevance standpoint among most comparative groups, questioning systematic preoperative addition of mechanical bowel preparation to oral antibiotics alone in all patients for minimally invasive colorectal surgery. See Video Abstract at http://links.lww.com/DCR/B828