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Using a conjunction of Cluster in the mid‐altitude dayside magnetosphere and Swarm in the low‐altitude ionosphere, we show, by employing multi‐spacecraft analysis, that matched, strong magnetic perturbations and the corresponding mesoscale field‐aligned current (FAC) structures are measured in the high latitude polar cusp region during the 7 October 2015 storm. Two pairs of opposite (positive/negative) FACs are observed by both Cluster and Swarm, which may relate to pulsed magnetic reconnection at the dayside magnetopause. Furthermore, the current intensity of these matched FACs decreases from high to low latitude, consistent with the time elapsed since reconnection. Corresponding geomagnetic disturbances are also observed by ground stations. Our observations provide direct evidence for the coupling of mesoscale FACs between the magnetosphere, ionosphere and ground in the polar cusp region, where the signatures are driven in this case by conditions suitable for inducing reconnection. Plain Language Summary: Field‐aligned currents (FACs) are the key medium for the interaction between the distant space magnetosphere (a region filled with Earth's magnetic field) and the near‐Earth space ionosphere. Magnetic reconnection is the most important process to transfer solar wind energy from dayside magnetosphere to nightside, which is accompanied by the generation of FACs extending from the high latitude region of the ionosphere to the magnetosphere. For such structures, extending across different space regions, joint observations by multiple spacecraft are necessary. Using simultaneous measurements of Cluster in the magnetosphere, Swarm in the ionosphere and geomagnetic stations on the ground, coordinated mesoscale FAC structures could show matched signatures in the magnetosphere and the ionosphere and the corresponding geomagnetic disturbances on the ground. Our observations provide direct evidence for the magnetosphere‐ionosphere‐ground coupling during the pulsed magnetic reconnection process. Key Points: Multi‐spacecraft Cluster and Swarm reveal matched magnetic perturbation and corresponding mesoscale field‐aligned currents (FACs) at different altitudes in the cusp regionMultiple pairs of opposite FACs associated with pulsed magnetic reconnection are dominant currents system at the dayside during storm timeDirect evidence for detailed dayside mesoscale FACs coupling between magnetosphere, ionosphere and ground is provided [ABSTRACT FROM AUTHOR]

OBJECTIVE: Our aim is to investigate the efficacy and safety of tirofiban in the treatment of patients experiencing progressive ischemic stroke (PIS). PATIENTS AND METHODS: A retrospective analysis was performed on the clinical data of 150 patients with ischemic stroke admitted to our hospital from May 2018 to December 2019. All the patients were divided into two groups according to different treatment methods. In Control group, conventional comprehensive treatment and antiplatelet therapy with aspirin + clopidogrel were conducted, while tirofiban was administered in Tirofiban group in addition to the treatments in Control group. Neurological deficits were scored by means of the National Institutes of Health Stroke Scale (NIHSS) at the time of progression and 30 d after treatment, and the modified Rankin Scale (mRS) and Activity of Daily Living (ADL) scale were employed to assess prognosis at 90 d after treatment. Thereafter, the platelet aggregation rate, platelet adhesion rate, plateletcrit (PCT), platelet distribution width (PDW), and platelet inhibition rate were measured before and after treatment. Finally, the patients were followed up, and the occurrence of hemorrhage events during treatment and within 90 d after discharge was recorded. RESULTS: After treatment, all the patients had significantly lower NIHSS and mRS scores and a dramatically higher Barthel index (BI) than those before treatment (p<0.001). At 90 d after treatment, Tirofiban group exhibited significantly higher BI (p<0.001) and lower mRS score than Control group (p=0.011). In addition, at 14 d after treatment, the clinical efficacy was assessed for all the patients. It was found that the overall response rate in Tirofiban group was substantially higher than that in Control group [82.7% (62/75) vs. 64.0% (48/75), p=0.009]. At 7 d after treatment, the PCT and adenosine diphosphate (ADP) platelet inhibition rate in Tirofiban group were markedly higher than those in Control group (p=0.006, p<0.001), and Tirofiban group had remarkably lower measured values of platelet aggregation rate, platelet adhesion rate and PDW than Control group (p=0.007, p=0.021, p<0.001). After treatment, the levels of serum IL-6 and hs-CRP declined notably in the two groups of patients, and the differences in their levels at 2 and 14 d after treatment between the two groups were statistically significant (p<0.05). During treatment and within 90 d after discharge, both groups of patients had no cerebral hemorrhage, gastrointestinal hemorrhage, and severe hemorrhage adverse events requiring blood transfusion, but they experienced subcutaneous ecchymosis, epistaxis, gingival hemorrhage, and hemorrhage around the infarct, which were improved after symptomatic treatment. Moreover, the occurrence rate of hemorrhage in Tirofiban group was higher than that in Control group, showing no statistically significant difference (p>0.05). CONCLUSIONS: Tirofiban combined with conventional basic treatment can greatly improve neurological deficits and disease outcomes, alleviate platelet adhesion, and reduce platelet activation without increasing the risk of hemorrhage in PIS patients. [ABSTRACT FROM AUTHOR]

We use Magnetospheric Multiscale (MMS) data to investigate the energy dissipation in a magnetopause reconnection electron diffusion region (EDR) event with moderate guide field. The four MMS spacecraft were separated by about 10 km so that comparative study among spacecraft within the EDR can be implemented. Similar magnetic field and electric current properties at each spacecraft indicate the formation of a quasi‐homogeneous magnetic and current structure in the diffusion region. However, we find that the energy dissipations detected by each spacecraft are still different due to the temporal or spatial effect of the out‐of‐plane reconnection electric field (EM) within the dissipation region. Our study suggests that the nonuniform or unsteady energy dissipation in the reconnection EDR may be a universal process. Plain Language Summary: Magnetic reconnection is a fundamental physical process during which magnetic topologies are changed and magnetic energy is transferred to plasma. Although the effects and structures created by reconnection can be very large in scales, reconnection is actually triggered within a small diffusion region. In the electron diffusion region, energy dissipation is a significant issue, which needs to be investigated further. Previous studies have shown that energy dissipation can be localized and oscillatory due to plasma waves or turbulent environment. Our study shows that the energy dissipations are still nonuniform or unsteady even under diffusion region with quasi‐homogeneous magnetic field and electric current structure. Thus, we suggest that the nonuniform or unsteady energy dissipation in the reconnection dissipation region is a universal process. Key Points: A quasi‐homogeneous magnetic field and current structure in the reconnection electron diffusion region at the magnetopause is observedThe reconnection electric field (EM) in the electron diffusion region is nonuniform among the four spacecraftThe energy dissipations are nonuniform due to the temporal or spatial effect of the reconnection electric field [ABSTRACT FROM AUTHOR]