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We report the first global, time-dependent simulation of the Mars upper atmospheric responses to a realistic solar flare event, an X8.2 eruption on 10 September 2017. The Mars Global Ionosphere-Thermosphere Model runs with realistically specified flare irradiance, giving results in reasonably good agreement with the Mars Atmosphere and Volatile EvolutioN spacecraft measurements. It is found that the ionized and neutral regimes of the upper atmosphere are significantly disturbed by the flare but react differently. The ionospheric electron density enhancement is concentrated below ~110-km altitude due to enhanced solar X-rays, closely following the time evolution of the flare. The neutral atmospheric perturbation increases with altitude and is important above ~150-km altitude, in association with atmospheric upwelling driven by solar extreme ultraviolet heating. It takes ~2.5 hr past the flare peak to reach the maximum disturbance and then additional ~10 hr to generally settle down to preflare levels.

In recent years, transdermal drug delivery systems have gained considerable attention for their ability to enhance patient compliance and provide consistent drug release. However, the barrier function of the skin's outermost layer remains the foremost challenge in these systems. As a result, there is a growing interest in the use of ethosomes as a cutting-edge nanocarrier in drug delivery. This review presents the concept and mechanism of action of ethosomes as well as the numerous types and preparation techniques available. It also discusses the significance of characterization methods and how they impact ethosomal properties along with recent advancements and applications in the realm of transdermal drug delivery. Ethosomes exhibit tremendous potential for the pharmaceutical industry, and optimizing preparation methods, performing comprehensive property studies, and exploring their applications are critical areas for future research. [ABSTRACT FROM AUTHOR]

A comprehensive modeling study has been conducted to investigate space weather effects at Mars during the 10 September 2017 solar flare, utilizing an integrated framework that combines the global magnetohydrodynamic (MHD) model and Mars Global Ionosphere‐Thermosphere Model (MGITM). This is the first time the thermosphere‐ionosphere‐magnetosphere system is self‐consistently simulated under realistic, time‐varying conditions. Our simulations align well with observations from the Mars Atmosphere and Volatile EvolutioN (MAVEN). Recognizing that complexities due to highly disturbed upstream conditions and rotating crustal fields obscure solar flare effects in orbit‐to‐orbit comparisons, we perform controlled simulations of nonflare and flare cases and exploit their contrast to quantify spatiotemporal variations in flare impact. Our results highlight pronounced and rapid dayside ionospheric perturbations, contrasting with weaker and delayed nightside responses. Notably, in the topside ionosphere, O2+ ${\mathrm{O}}_{2}^{+}$ and CO2+ ${\mathrm{O}}_{2}^{+}$ densities increase primarily on the dayside below ∼ ${\sim} $300 km altitude, peaking with an increase of 20%–30%. The O+ ${\mathrm{O}}^{+}$ density shows a more significant increase of up to ∼ ${\sim} $50%, extending into the magnetosphere and nightside via plasma transport, increasing its total loss rate by 14%. We observe distinct altitude‐dependent patterns in dayside electron density enhancements in percent, characterized by a weakening with altitude and a rapid decay below ∼ ${\sim} $150 km in line with the flare development, and a gradual intensification between ∼ ${\sim} $150–300 km due to plasma transport and flare‐induced atmospheric upwelling. Earlier Mars Global Surveyor observations were limited to the low‐altitude pattern due to atmospheric expansion and missed the higher altitude variations observed by MAVEN. Plain Language Summary: This study investigates the impact of a powerful X8.2‐class solar flare on 10 September 2017 at Mars. Using an integrated modeling framework that combines two state‐of‐the‐art global models, our simulations provide insights into distinct altitude‐dependent patterns of flare‐induced ionospheric density enhancements, pronounced day‐night asymmetry, and a moderate increase in ion escape. Key findings include rapid variations in ionospheric density enhancements at lower altitudes, with a gradual intensification at higher altitudes due to plasma transport and atmospheric upwelling. These findings contribute to a better understanding of how solar flares impact the space environment of unmagnetized or weakly‐magnetized planets like Mars. Key Points: The solar flare causes pronounced and rapid dayside ionospheric perturbations and weaker and delayed effects on the nightsideO2+ and CO2+ densities increase by 20%–30% above 150 km on the dayside, while O+ increases by up to 50% and over larger spacePercentage increase of dayside e− densities decreases with altitude and decays fast below ∼150 km, and rises and decays slowly above that [ABSTRACT FROM AUTHOR]

Measurements of Ar and N2 densities at 160–250 km altitude from the Mars Atmosphere and Volatile Evolution (MAVEN) Neutral Gas and Ion Mass Spectrometer (NGIMS) during February 2015–February 2023 are analyzed to provide a comprehensive analysis of their diurnal‐ and zonal‐mean (DZM) structures, and ZM (solar‐synchronous) diurnal (DW1) and semidiurnal (SW2) tides. After applying a solar flux trend correction, multi‐year binning and averaging with respect to longitude, local solar time (LST), latitude and Ls at each height results in the first full global picture of these components of the ZM thermosphere for a single climatological Mars year. The following new observational insights into Mars thermosphere are obtained: The DZM N2 latitude versus Ls (latvsLs) structures contain a prominent latitudinally‐symmetric annual component (∼±25%–35%) due to the eccentricity of Mars orbit around the Sun, and an antisymmetric component (∼±30%–45%) below about 190 km that is seasonally‐symmetric and thus consistent with the tilt of Mars rotation axis. Aperiodic deviations from these symmetries increase with height and are tentatively attributed to dissipation of waves originating in the lower atmosphere. DW1 and SW2 maximize around 200–220 km altitude, suggesting existence of an unknown dissipation mechanism at higher altitudes. The DZM, DW1 and SW2 components of Ar generally exceed those of N2 by factors of 1.4–2.5. The scale heights of Ar and N2 between 205 and 245 km are also employed to derive DZM exosphere temperatures, which reflect aperiodic ∼±15K deviations from the annual‐mean in the latvsLs frame. Key Points: DZM of N2 and Ar densities (160–250 km) at Mars contain periodic latitude‐Ls variabilities due to Mars eccentric orbit and its axial tiltAperiodic latitude‐Ls variabilities in DZM N2 and Ar are potentially attributable to dissipation of waves from the lower atmosphereDZM exosphere temperatures derived from N2 and Ar scale heights (205–245 km) are aperiodic in the latitude‐Ls frame and are of order ±15K [ABSTRACT FROM AUTHOR]

We present a comprehensive study of the nightside aurora phenomenon on Mars, utilizing observations from EMUS onboard Emirates Mars Mission. The oxygen emission at 130.4 nm is by far the brightest FUV auroral emission line observed at Mars. Our statistical analysis reveals geographic, solar zenith angle, local time, and seasonal dependencies of auroral occurrence. Higher occurrence of aurora is observed in regions of open magnetic topology, where crustal magnetic fields are either very weak or both strong and vertical. Aurora occurs more frequently closer to the terminator and is more likely on the dusk side than on the dawn side of the night hemisphere. A pronounced auroral feature appears close to midnight local times in the southern hemisphere, consistent with the spot of energetic electron fluxes previously identified in the Mars Global Surveyor data. This auroral spot is more frequent after midnight than before. Additionally, some regions on Mars are "aurora voids" where essentially no aurora occurs. Aurora exhibits a seasonal dependence, with a major enhancement near perihelion. Non–crustal field aurora additionally shows a secondary enhancement near Ls 30°. This seasonal variability is a combination of the variability in ionospheric photoelectrons and thermospheric atomic oxygen abundance. Auroral occurrence also shows an increase with the rise of Solar Cycle 25. The brightest auroral pixels are observed during space weather events such as Coronal Mass Ejections and Stream Interaction Regions. These observations not only shed light on where and when Martian aurora occurs, but also add to our understanding of Mars' magnetic environment and its interaction with the heliosphere. Plain Language Summary: In this study, we explore the phenomenon of aurora on the nightside of Mars, using observations from the highly sensitive Emirates Mars Ultraviolet Spectrometer (EMUS) on the Emirates Mars Mission. Our analysis reveals distinct patterns in auroral occurrence on the planet. For instance, there is a higher rate of auroral activity in regions where Mars' magnetic field lines are open (i.e., connected to the collisional atmosphere at one end). We also found that aurora is more common near the terminator (with the occurrence decreasing as the solar zenith angle increases), and particularly during the evening hours, as opposed to early morning. Interestingly, these auroral events also show a seasonal dependence, peaking around perihelion in a Martian year, when Mars is closest to the sun. This seasonal pattern corresponds with the variation of photoelectrons in Mars' dayside ionosphere and the atomic oxygen abundance in the thermosphere. Auroral occurrence increases with increasing solar activity. Also, the auroral brightness increases during space weather events. Our study not only gives us a clearer picture of where and when the aurora occurs on Mars but also hints at the underlying processes influencing them, offering insights into the planet's magnetic and charged particle environment. Key Points: Higher auroral occurrence is observed in regions of open magnetic topology, where crustal fields are either very weak or primarily verticalAurora occurs more frequently near the terminator compared to deep night, with higher occurrence at dusk than at dawnAurora occurs more frequently near perihelion, with the brightest auroral pixels observed during space weather events [ABSTRACT FROM AUTHOR]

Separating plasma or serum from blood is essential for precise testing. However, extracting precise plasma quantities outside the laboratory poses challenges. A recent study has introduced a capillary force-driven membrane filtration technique to accurately separate small plasma volumes. This method efficiently isolates 100–200 μ L of pure human whole blood with a 48% hematocrit, resulting in 5–30 μ L of plasma with less than a 10% margin of error. The entire process is completed within 20 min, offering a simple and cost-effective approach to blood separation. This study has successfully addressed the bottleneck in self-service POCT, ensuring testing accuracy. This innovative method shows promise for clinical diagnostics and point-of-care testing. [ABSTRACT FROM AUTHOR]

This study examines whether board social networks are associated with executive trading profitability. Using a sample of US public firms with a history of executive trading from years 2000 to 2015, we find robust evidence that the profitability of executive trading is significantly lower in firms with higher levels of board social networks. The evidence is consistent with our view that board social networks effectively curb executives' private information advantage over outsiders, thus leading to a lower level of managerial rent‐seeking. Our research has policy implications for regulators concerned about the role of corporate board in capital markets. [ABSTRACT FROM AUTHOR]

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Measurements of CO2, Ar and N2 densities from the Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution Mission (MAVEN) between 150 and 200 km altitude during 2015–2022 are analyzed to reveal diurnal (DW1), semidiurnal (SW2) and terdiurnal (TW3) solar‐synchronous tides in Mars thermosphere. Multi‐year‐mean tidal perturbations on a diurnal‐ and zonal‐mean background, corrected for solar flux variations, are reported as a function of latitude (48°S–48°N), altitude and solar longitude (Ls). The DW1, SW2 and TW3 amplitudes at for example, 180 km altitude are of order 90%–120%, 15%–20%, and ≲10% for CO2 and Ar, and roughly 2/3 these values for N2, the latter presumably due to the difference in molecular weight from the other species. Through examination of vertical phase progressions, DW1 is concluded to be mainly excited in situ, but SW2 and TW3 contain significant contributions from tides propagating upward from lower altitudes. By analogy with studies for Earth's thermosphere, the DW1 amplitudes and phases are thought to reflect the combined influences of thermal expansion and vertical winds. Points of agreement and disagreement with DW1, SW2, and TW3 amplitudes and phases derived from the Mars Climate Database are noted and interpreted. Key Points: Global‐scale solar‐synchronous tides are derived from Mars Atmosphere and Volatile Evolution Mission/Neutral Gas and Ion Mass Spectrometer measurements of CO2, Ar, and N2 at Mars, 150–200 kmThe diurnal tide originates mainly in situ; semidiurnal and terdiurnal tides show evidence of upward propagation from belowPoints of agreement and disagreement with the Mars Climate Database are noted and interpreted [ABSTRACT FROM AUTHOR]