Diclofenac sorption from synthetic water: Kinetic and thermodynamic analysis

This work investigated diclofenac sorption on 0.5g L-1 activated carbon in a range of temperature (288-318K) and of initial sorbate concentration (24-218mgL-1). Thermodynamic modelling was carried out with the Langmuir isotherm. For kinetic modelling we compared the so-called Diffusion-Controlled Langmuir Kinetics (DCLK) and the pseudo-second order (PSO) model. The maximum sorption capacity of the sorbent, equal to 180mgg-1, was independent of temperature. Experimental data fitted well with both kinetic models, yet the DCLK model was found to be more informative about the mechanism of the process. Kinetic parameters (α, β) increased with the temperature, with α value rising from 5×10-5 to 20×10-5 L mg-1min-0.5, and β value rising from 3×10-6 to 20×10-6 L mg-1min-1 in the temperature range investigated

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission

Northrop Grumman TR202 LOX/LH2 Deep Throttling Engine Technology Project Status

NASA's Propulsion and Cryogenic Advanced Development (PCAD) project is currently developing enabling propulsion technologies in support of future lander missions. To meet lander requirements, several technical challenges need to be overcome, one of which is the ability for the descent engine(s) to operate over a deep throttle range with cryogenic propellants. To address this need, PCAD has enlisted Northrop Grumman Aerospace Systems (NGAS) in a technology development effort associated with the TR202 engine. The TR202 is a LOX/LH2 expander cycle engine driven by independent turbopump assemblies and featuring a variable area pintle injector similar to the injector used on the TR200 Apollo Lunar Module Descent Engine (LMDE). Since the Apollo missions, NGAS has continued to mature deep throttling pintle injector technology. The TR202 program has completed two series of pintle injector testing. The first series of testing used ablative thrust chambers and demonstrated igniter operation as well as stable performance at discrete points throughout the designed 10:1 throttle range. The second series was conducted with calorimeter chambers and demonstrated injector performance at discrete points throughout the throttle range as well as chamber heat flow adequate to power an expander cycle design across the throttle range. This paper provides an overview of the TR202 program, describing the different phases and key milestones. It describes how test data was correlated to the engine conceptual design. The test data obtained has created a valuable database for deep throttling cryogenic pintle technology, a technology that is readily scalable in thrust level

Robust Limits from Upcoming Neutrino Telescopes and Implications on Minimal Dark Matter Models

Experimental developments in neutrino telescopes are drastically improving their ability to constrain the annihilation cross-section of dark matter. In this paper, we employ an angular power spectrum analysis method to probe the galactic and extra-galactic dark matter signals with neutrino telescopes. We first derive projections for a next generation of neutrino telescope that is inspired by KM3NeT. We emphasise that such analysis is much less sensitive to the choice of dark matter density profile. Remarkably, the projected sensitivity is improved by more than an order of magnitude with respect to the existing limits obtained by assuming the Burkert dark matter density profile describing the galactic halo. Second, we analyse minimal extensions to the Standard Model that will be maximally probed by the next generation of neutrino telescopes. As benchmark scenarios, we consider Dirac dark matter in $s$- and $t$-channel models with vector and scalar mediators. We follow a global approach by examining all relevant complementary experimental constraints. We find that neutrino telescopes will be able to competitively probe significant portions of parameter space. Interestingly, the anomaly-free $L_{\mu}-L_{\tau}$ model can potentially be explored in regions where the relic abundance is achieved through freeze-out mechanism

Northrop Grumman TR202 LOX/LH2 Deep Throttling Engine Project Status

NASA's Propulsion and Cryogenic Advanced Development (PCAD) project is currently developing enabling propulsion technologies in support of the Exploration Initiative, with a particular focus on the needs of the Altair Project. To meet Altair requirements, several technical challenges need to be overcome, one of which is the ability for the lunar descent engine(s) to operate over a deep throttle range with cryogenic propellants. To address this need, PCAD has enlisted Northrop Grumman Aerospace Systems (NGAS) in a technology development effort associated with the TR202, a LOX/LH2 expander cycle engine driven by independent turbopump assemblies and featuring a variable area pintle injector similar to the injector used on the TR200 Apollo Lunar Module Descent Engine (LMDE). Since the Apollo missions, NGAS has continued to mature deep throttling pintle injector technology. The TR202 program has completed two phases of pintle injector testing. The first phase of testing used ablative thrust chambers and demonstrated igniter operation as well as stable performance at several power levels across the designed 10:1 throttle range. The second phase of testing was performed on a calorimeter chamber and demonstrated injector performance at various power levels (75%, 50%, 25%, 10%, and 7.5%) across the throttle range as well as chamber heat flux to show that the engine can close an expander cycle design across the throttle range. This paper provides an overview of the TR202 program. It describes the different phases of the program with the key milestones of each phase. It then shows when those milestones were met. Next, it describes how the test data was used to update the conceptual design and how the test data has created a database for deep throttling cryogenic pintle technology that is readily scaleable and can be used to again update the design once the Altair program's requirements are firm. The final section of the paper describes the path forward, which includes demonstrating continuously throttling with an actuator and pursuing a path towards integrated engine sea-level test-bed testing

Evaluating the use of graphene electrodes in sub-micrometric, high-frequency n-type organic transistors

In this work we report on fully operational sub-micrometric low voltage OFETs by using graphene as the source-drain electrodes pair and a high-κ ultra-thin dielectric in a local gate architecture. The impact of the graphene electrodes on the miniaturization of the organic devices has been assessed, with particular attention to the influence of the contact resistances as well as the parasitic overlap gate capacitance on the device bandwidth. By the use of a modified Transmission-Line-Method, contact resistances have been analyzed as function of the applied voltages, revealing characteristic functional trends that follow the doping state of graphene electrodes. Through impedance spectroscopy of the electrodes, cut-off frequencies as high as 105 Hz have been estimated, highlighting the peculiar role of quantum capacitance of graphene in such architectures

Eating Problems in Youths with Type 1 Diabetes During and After Lockdown in Italy: An 8-Month Follow-Up Study

Eighty-five youths with T1D and 176 controls aged 8–19 years were asked to complete online questionnaires (ChEAT and EAT-26) measuring disordered eating behaviors (DEBs) during (baseline) and after (8-month follow-up) the lockdown. DEB symptoms in all participants (especially younger than 13 years), glycemic control, and zBMI were found unchanged from baseline to follow-up (all p >.05). After 8 months, the ChEAT/EAT-26 critical score frequency decreased significantly in controls (p =.004), as was the score for the ChEAT/EAT-26’s Oral Control subscale in both groups (T1D: p =.005; controls: p =.01). Participants with T1D, especially those older than 13 years, had higher ChEAT/EAT-26 Dieting scores (p =.037) and lower ChEAT/EAT-26 Oral Control scores (p =.046) than controls. Unchanged DEB symptoms suggest that the COVID-19 restrictions did not significantly affect participants’ eating behaviors and that a general adaptation to the challenges of lockdown and other pandemic containment measures occurred in both T1D and control participants

Disordered eating behaviors in youths with type 1 diabetes during COVID-19 lockdown: an exploratory study

Background: Recent research indicates that patients with type 1 diabetes (T1D) are at higher risk for disordered eating behaviors (DEBs) than their peers without diabetes. The present study aimed to explore the prevalence of DEBs in a sample of Italian children and adolescents with T1D and in matched-pair healthy controls during the COVID-19 lockdown. Methods: In a cross-sectional study, 138 children and adolescents with T1D (aged 8.01–19.11 years, 65 boys) attending a Southern Italian diabetic service and 276 age- and gender-matched healthy peers voluntarily completed an online survey about eating behaviors (ChEAT and EAT-26), anthropometric characteristics, and clinical characteristics. Results: 8.69% (N = 12) of participants with T1D and 13.4% (N = 37) of controls had ChEAT/EAT-26 scores indicating presence of DEBs, with no differences between patients—whether children (total ChEAT score F(1, 157) =.104, p =.748) or adolescents (total EAT-26 score F(1, 255) =.135, p =.731)—and healthy peers. zBMI values were lower than those measured in the latest diabetes visit (p <.0001), while HbA1c values remained unchanged (p =.110). In both groups, adolescents had lower Oral Control scores than children (T1D: F(1, 138) = 20.411, p <.0001, η2 =.132, controls: F(1, 276) = 18.271, p <.0001, η2 =.063); additionally, gender (female) and age were found to be significant predictors of several ChEAT/EAT-26 scores. Conclusions: This exploratory study suggested that children and adolescents with T1D did not experience more DEB symptoms during the COVID-19 lockdown compared to healthy controls. Results revealed DEBs as more of a female adolescent developmental issue rather than a result of the challenges of living with a chronic illness under quarantine measures. Possible effects of parental pressure on their children’s eating behaviors in the context of home confinement and of using a non-diabetes-specific measure to assess DEBs are discussed

Effects of Azadirachta indica seed kernel extracts on early erythrocytic schizogony of Plasmodium berghei and pro-inflammatory response in inbred mice

Background: Medicinal plant research may contribute to develop new pharmacological control tools for vector borne diseases, such as malaria. Methods: The effects of methanol extracts (ME) obtained from seed kernel of ripe and unripe Azadirachta indica fruits were studied on erythrocytic proliferation of the rodent malaria parasite Plasmodium berghei strain ANKA and on mice pro-inflammatory response, as evaluated by measuring the matrix-metalloproteinase-9 (MMP-9) and tumour necrosis factor (TNF) plasma levels, in two mouse strains (C57BL/6 and BALB/c) which are considered as prototypical of Th1 and Th2 immune response, respectively. Results: ME obtained from seed kernel of unripe Azadirachta indica fruits decreased by about 30% the proportion of erythrocytes infected with the malaria parasite in C57BL/6 mice in the 4 days suppressive test. In this treatment group, MMP-9 and TNF levels were notably higher than those measured in the same mouse strain treated with the anti-malarial drug artesunate, Azadirachta indica kernel extracts from ripe fruits or solvent. In BALB/c mice, treatment with kernel extracts did not influence parasitaemia. MMP-9 and TNF levels measured in this mouse strain were notably lower than those recorded in C57BL/6 mice and did not vary among treatment groups. Conclusions: The effects of the ME on the parasite-host interactions appeared to be mouse strain-dependent, but also related to the ripening stage of the neem fruits, as only the unripe fruit seed kernel extracts displayed appreciable bioactivity

Impact of repeated NeemAzal®-treated blood meals on the fitness of Anopheles stephensi mosquitoes

Background: Herbal remedies are widely used in many malaria endemic countries to treat patients, in particular in the absence of anti-malarial drugs and in some settings to prevent the disease. Herbal medicines may be specifically designed for prophylaxis and/or for blocking malaria transmission to benefit both, the individual consumer and the community at large. Neem represents a good candidate for this purpose due to its inhibitory effects on the parasite stages that cause the clinical manifestations of malaria and on those responsible for infection in the vector. Furthermore, neem secondary metabolites have been shown to interfere with various physiological processes in insect vectors. This study was undertaken to assess the impact of the standardised neem extract NeemAzal® on the fitness of the malaria vector Anopheles stephensi following repeated exposure to the product through consecutive blood meals on treated mice. Methods: Batches of An. stephensi mosquitoes were offered 5 consecutive blood meals on female BALB/c mice treated with NeemAzal® at an azadirachtin A concentration of 60, 105 or 150 mg/kg. The blood feeding capacity was estimated by measuring the haematin content of the rectal fluid excreted by the mosquitoes during feeding. The number of eggs laid was estimated by image analysis and their hatchability assessed by direct observations. Results: A dose and frequency dependent impact of NeemAzal® treatment on the mosquito feeding capacity, oviposition and egg hatchability was demonstrated. In the 150 mg/kg treatment group, the mosquito feeding capacity was reduced by 50% already at the second blood meal and by 50 to 80% in all treatment groups at the fifth blood meal. Consequently, a 50 – 65% reduction in the number of eggs laid per female mosquito was observed after the fifth blood meal in all treatment groups. Similarly, after the fifth treated blood meal exposure, hatchability was found to be reduced by 62% and 70% in the 105 and 150 mg/kg group respectively. Conclusions: The findings of this study, taken together with the accumulated knowledge on neem open the challenging prospects of designing neem-based formulations as multi-target phytomedicines exhibiting preventive, parasite transmission-blocking as well as anti-vectorial properties. Keywords: Malaria, Vectors, Neem, Azadirachtin, Transmission-blocking, Anti-vectoria