As the formation of pyridoxal phosphate, the active cofactor of vitamin B
, is dependent on riboflavin 5-phosphate, we propose a fast and simple ultra-high performance liquid chromatography method ...for the simultaneous determination of the native B
vitamers pyridoxal, pyridoxine, pyridoxamine, their mono phosphorus esters and 4-pyridoxic acid as well as vitamin B
as riboflavin and its phosphorus ester riboflavin 5-phosphate in milk. Separation was achieved under 6.0min by reversed-phase and pH gradient elution. Sample preparation was optimized regarding various acids and pH levels. Changes in those parameters led to significant deviations of sample matrix breakdown efficiency. The optimized method was then validated regarding specificity, accuracy, precision, linearity, range, detection and quantification limits. As the method performed satisfactory, is was used to study commercial liquid cow's milk (n=31), regarding effects of the employed preservation technique (pasteurization, extended shelf-life, ultra-high temperature) on the composition and content of B
and B
vitamers. In cow's milk, vitamin B
mostly consists of pyridoxal and its phosphate ester, with pyridoxal phosphate being the bulk component. The catabolite of the vitamin B
metabolism, 4-pyridoxic acid was present in significant amounts in all studied samples, with up to 2.69μmolL
. Vitamin B
was present as riboflavin and its phosphate ester up to 12.86μmolL
.
Alcohol use disorder (AUD) alters decision-making control over actions, but disruptions to the responsible neural circuit mechanisms are unclear. Premotor corticostriatal circuits are implicated in ...balancing goal-directed and habitual control over actions and show disruption in disorders with compulsive, inflexible behaviors, including AUD. However, whether there is a causal link between disrupted premotor activity and altered action control is unknown. Here, we find that mice chronically exposed to alcohol (chronic intermittent ethanol CIE) showed impaired ability to use recent action information to guide subsequent actions. Prior CIE exposure resulted in aberrant increases in the calcium activity of premotor cortex (M2) neurons that project to the dorsal medial striatum (M2-DMS) during action control. Chemogenetic reduction of this CIE-induced hyperactivity in M2-DMS neurons rescued goal-directed action control. This suggests a direct, causal relationship between chronic alcohol disruption to premotor circuits and decision-making strategy and provides mechanistic support for targeting activity of human premotor regions as a potential treatment in AUD.
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•Chronic alcohol disrupts action control•Chronic alcohol induces hyperactive M2-DMS during action control•Chemogenetic suppression of M2-DMS hyperactivity rescues action control
Appropriate action control relies on learning from recent experiences. Using a rodent model, Schreiner et al. find evidence that chronic alcohol exposure disrupts action control by inducing aberrant hyperactivity in premotor corticostriatal circuits. These findings support the targeting of premotor cortex activity for therapeutic treatment in alcohol use disorder.
Deciphering absolute configuration of a single molecule by direct visual inspection is the next step in compound identification, with far-reaching implications for medicinal chemistry, pharmacology, ...and natural product synthesis. We demonstrate the feasibility of this approach utilizing low temperature atomic force microscopy (AFM) with a CO-functionalized tip to determine the absolute configuration and orientation of a single, adsorbed 123tetramantane molecule, the smallest chiral diamondoid. We differentiate between single enantiomers on Cu(111) by direct visual inspection, and furthermore identify molecular dimers and molecular clusters. The experimental results are confirmed by a computational study that allowed quantification of the corresponding intermolecular interactions. The unique toolset of absolute configuration determination combined with AFM tip manipulation opens a route for studying molecular nucleation, including chirality-driven assembly or reaction mechanisms.
New meta‐substituted tetraaryl adamantane derivatives were synthesized through one‐step Friedel‐Crafts adamantylation by using AlCl3 in combination with t‐butyl bromide. The products exhibit improved ...(over tetraphenyl adamantane) highly directional white‐light emission upon irradiation with a continuous wave (CW) laser diode.
An easier path to organic white light emitters is accessible through the direct, meta‐selective arylation of adamantane. The combination of AlCl3 and t‐BuBr aids this reaction, which occurs smoothly, inter alia, also with fluorobenzene, which had proven to be difficult in the past and opposes the expected regioselectivity. Indeed, the products generate white light when irradiated with a continuous wave (CW) laser diode with improved intensities over the parent system, tetraphenyladamantane.
In view of industrial fractionation processes for edible insects, supercritical CO2 extraction of Tenebrio molitor larval oil was studied. The influence of extraction parameters on defatting of ...larvae was investigated using a full factorial design. Furthermore, the effect of operating conditions on extraction kinetics, fatty acid composition, and acidity of mealworm oil was evaluated. Pressure, time, and their interaction showed the most significant effects on defatting. Maximal defatting (95%) was achieved at 400/250 bar, 45°C, and 105 min. Extraction kinetics revealed that incrementing pressure increased the solubility of mealworm oil in SC–CO2 enabling faster extraction. Extracted oils contained 72% unsaturated fatty acids, and oleic acid accounted for 42% of total FAME. Oil composition and acidity were found to be affected by extraction parameters showing the highest amount of low molecular and free fatty acids after slow extraction at 250 bar and 65°C. Use of selective extraction conditions enabled simple time‐dependent fractionation and deacidification yielding fractions with tailored fatty acid profiles or facilitating subsequent refining processes, respectively. Defatting performance and oil composition were not substantially different when using hexane as a solvent in comparison to SC–CO2. Mealworm larvae can be effectively defatted using SC–CO2 at high pressure and moderate temperature, yielding two valuable fractions: oil‐ and protein‐rich residue.
Practical applications: Mealworm larvae are promising candidates for the inclusion of edible insects in the western food and feed industry due to modest breeding demands, existing rearing knowledge, and high contents of protein and fat. The development of fractionation processes for the production of standardized insect bulk materials and incorporation in feed or food in analogy to soy and other plant raw materials rich in fat and protein will help gain industrial applicability and enhance consumer acceptance. Depending on the processing approach, a defatting step is crucial prior to protein extraction. The results of this study indicate that SC–CO2 extraction is suitable for achieving a high yield of solvent‐free oil and a protein‐enriched, solvent‐free residue at low extraction temperatures. Both fractions can be further refined and purified in order to achieve valuable intermediates for food and feed applications.
The SC–CO2 extraction of mealworms yielded highly unsaturated oil and a defatted residue containing protein and chitin. The operating parameters clearly affected the defatting performance and the extraction rate.
The SC–CO2 extraction of mealworms yielded highly unsaturated oil and a defatted residue containing protein and chitin. The operating parameters clearly affected the defatting performance and the extraction rate.
Abstract
Polyhedral nitrogen containing molecules such as prismatic P
3
N
3
- a hitherto elusive isovalent species of prismane (C
6
H
6
) - have attracted particular attention from the theoretical, ...physical, and synthetic chemistry communities. Here we report on the preparation of prismatic P
3
N
3
1,2,3-triaza-4,5,6-triphosphatetracyclo2.2.0.0
2,6
.0
3,5
hexane by exposing phosphine (PH
3
) and nitrogen (N
2
) ice mixtures to energetic electrons. Prismatic P
3
N
3
was detected in the gas phase and discriminated from its isomers utilizing isomer selective, tunable soft photoionization reflectron time-of-flight mass spectrometry during sublimation of the ices along with an isomer-selective photochemical processing converting prismatic P
3
N
3
to 1,2,4-triaza-3,5,6-triphosphabicyclo2.2.0hexa-2,5-diene (P
3
N
3
). In prismatic P
3
N
3
, the P–P, P–N, and N–N bonds are lengthened compared to those in, e.g., diphosphine (P
2
H
4
), di-anthracene stabilized phosphorus mononitride (PN), and hydrazine (N
2
H
4
), by typically 0.03–0.10 Å. These findings advance our fundamental understanding of the chemical bonding of poly-nitrogen and poly-phosphorus systems and reveal a versatile pathway to produce exotic, ring-strained cage molecules.
In this paper, an ionospheric electron density reanalysis algorithm was used to generate global optimized electron density during the 17–18 March 2013 geomagnetic storm by assimilating ~10 low Earth ...orbit satellites based and ~450 ground global navigation satellite system receiver‐based total electron content into a background ionospheric model. The reanalyzed electron density could identify the large‐scale ionospheric features quite well during storm time, including the storm‐enhanced density, the positive ionospheric storm effect during the initial and main phases, and the negative ionospheric storm effect during the recovery phase. The simulations from the Thermosphere Ionosphere Electrodynamics General Circulation Model can reproduce similar large‐scale ionospheric disturbances as seen in the reanalysis results. Both the reanalysis and simulations show long‐lasting (>17 h) daytime negative storm effect over the Asia sector as well as hemispheric asymmetry during the recovery phase. Detailed analysis of the Global Ultraviolet Imager‐derived O/N2 ratio and model simulations indicate that the polar ward meridional wind disturbance, the downward E × B drift disturbance and O/N2 depletion might be responsible for the negative storm effect. The hemispheric asymmetry is mainly caused by the geomagnetic field line configuration, which could cause hemispheric asymmetry in the O/N2 depletion.
Key Points
Global ionospheric storm effects during 17 March 2013 geomagnetic storm were studied based on the data assimilation and TIEGCM simulation
Both the reanalysis and simulations show long‐lasting and hemispheric asymmetry negative storm effect during the recovery phase
The wind, E x B drift disturbance, and hemispheric asymmetry O/N2 depletion might be responsible for the negative storm effect
The FORMOSAT‐3/COSMIC (F3/C) satellites are used to study the climatology of equatorial plasma bubbles (EPBs) during the low to moderate solar flux years (2008–2013). We use the F3/C total electron ...content to identify the presence of EPBs and investigate the background conditions for the initiation of EPBs. The results reveal that the EPB activities have strong solar dependence. The longitudinal and seasonal trends of EPBs are highly correlated to the angle between the dusk solar terminator and magnetic field lines near the magnetic equator. Asymmetries of EPBs between solstices and equinoxes exist and could be due partly to the asymmetry of equatorial ionization anomaly structures, which result in longitudinal differences as well. EPBs extend to higher altitudes and latitudes during the ascending phase of Solar Cycle 24 (2011–2013) due mainly to the increase of background electron density. However, an altitudinal asymmetry of EPBs occurs in moderate solar flux years, which is likely due to the suppression or lower growth and occurrence rates of EPBs. In addition to vertical drift, tidal forcing also contributes to the longitudinal and seasonal distributions of EPBs. Upwellings and precursor waves preceding the EPBs are observed climatologically, which likely play a vital role in initiating the EPBs. This study also reveals a vertical connection between the equatorial ionospheric irregularities and atmospheric forcing on a climatological basis.
Plain Language Summary
Equatorial plasma bubbles (EPBs) are an important space weather phenomenon that are often generated over the magnetic equator around twilight. They are ionospheric irregularities that can cause plasma depletions along the geomagnetic field lines, displaying geomagnetic conjugacy in both hemispheres. Since the ionospheric plasma is one of the significant error sources of the Global Navigation Satellite System (GNSS), EPBs are considered to be a primary disrupter of GNSS communication and navigation. Postsunset rise (PSSR) of the equatorial ionosphere due to vertical ion drift is often used to explain the occurrence of EPBs; however, it cannot fully explain the day‐to‐day variability of EPBs and the features of EPBs in patches and clusters. Mysteries abound around the EPBs and the underlying physics that initiates the EPBs remain unsolved. Here we utilize the FORMOSAT‐3/COSMIC to investigate the underlying background conditions for the generation of EPBs. We find that, in addition to PSSR, symmetric equatorial ionization anomaly, as well as tidal forcing, appears to provide conditions favorable for the initiation of EPBs. Atmospheric tidal waves contribute to the longitudinal and seasonal distribution of EPBs as well. Bottomside ionospheric undulations due to atmospheric forcing are likely playing a vital role in initiating the EPBs.
Key Points
Symmetric EIA provides a condition favorable for the growth of EPBs
Longitudinal three‐ and four‐peak EPB structures related to tidal forcing are identified
Upwellings are observed in the bottomside ionosphere preceding the growth of EPBs
Soil moisture dynamics reflect the complex interactions of meteorological conditions with soil, vegetation and terrain properties. In this study, intermediate-scale soil moisture estimates from the ...cosmic-ray neutron sensing (CRNS) method are evaluated for two semiarid ecosystems in the southwestern United States: a mesquite savanna at the Santa Rita Experimental Range (SRER) and a mixed shrubland at the Jornada Experimental Range (JER). Evaluations of the CRNS method are performed for small watersheds instrumented with a distributed sensor network consisting of soil moisture sensor profiles, an eddy covariance tower, and runoff flumes used to close the water balance. We found a very good agreement between the CRNS method and the distributed sensor network (root mean square error (RMSE) of 0.009 and 0.013 m(3)m(-3) at SRER and JER, respectively) at the hourly timescale over the 19-month study period, primarily due to the inclusion of 5 cm observations of shallow soil moisture. Good agreement was also obtained in soil moisture changes estimated from the CRNS and watershed water balance methods (RMSE of 0.001 and 0.082 m(3) m(-3) at SRER and JER, respectively), with deviations due to bypassing of the CRNS measurement depth during large rainfall events. Once validated, the CRNS soil moisture estimates were used to investigate hydrological processes at the footprint scale at each site. Through the computation of the water balance, we showed that drier-than-average conditions at SRER promoted plant water uptake from deeper soil layers, while the wetter-than-average period at JER resulted in percolation towards deeper soils. The CRNS measurements were then used to quantify the link between evapotranspiration and soil moisture at a commensurate scale, finding similar predictive relations at both sites that are applicable to other semiarid ecosystems in the southwestern US.
Epidemiological data suggest that consuming diets rich in carotenoids can reduce the risk of developing several non-communicable diseases. Thus, we investigated the extent to which carotenoid ...contents of foods can be increased by the choice of food matrices with naturally high carotenoid contents and thermal processing methods that maintain their stability. For this purpose, carotenoids of 15 carrot (Daucus carota L.) cultivars of different colors were assessed with UHPLC-DAD-ToF-MS. Additionally, the processing effects of air drying, air frying, and deep frying on carotenoid stability were applied. Cultivar selection accounted for up to 12.9-fold differences in total carotenoid content in differently colored carrots and a 2.2-fold difference between orange carrot cultivars. Air frying for 18 and 25 min and deep frying for 10 min led to a significant decrease in total carotenoid contents. TEAC assay of lipophilic extracts showed a correlation between carotenoid content and antioxidant capacity in untreated carrots.
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