RESUMEN
The sandwich stent technique is a commonly used method to preserve unilateral internal iliac artery flow when treating iliac artery aneurysm. In this case, covered stent grafts (Viabahn, Gore) were used to build the iliac limb of a sandwich stent. However, if Viabahn is released without long sheath protection, the trigger wire is easily wound on another stent, resulting in the Viabahn delivery system being inseparable from the stent. If we drag it forcefully, it would easily cause the entire sandwich stent graft to shift or even fall into the thoracic aorta. This complication is catastrophic. Here we report the case of a patient whose sandwich stent system disengaged and entered the thoracic aorta. We took corresponding measures to remedy it.
RESUMEN
Phase-change random access memory is a promising technique to realize universal memory and neuromorphic computing, where the demand for robust multibit programming drives exploration for high-accuracy resistance control in memory cells. Here in ScxSb2Te3 phase-change material films, we demonstrate thickness-independent conductance evolution, presenting an unprecedently low resistance-drift coefficient in the range of â¼10-4-10-3, â¼3-2 orders of magnitude lower compared to conventional Ge2Sb2Te5. By atom probe tomography and ab initio simulations, we unveiled that nanoscale chemical inhomogeneity and constrained Peierls distortion together suppress structural relaxation, rendering an almost invariant electronic band structure and thereby the ultralow resistance drift of ScxSb2Te3 films upon aging. Associated with subnanosecond crystallization speed, ScxSb2Te3 serves as the most appropriate candidate for developing high-accuracy cache-type computing chips.
RESUMEN
OBJECTIVE: To study the histogenesis and pathological characteristics of gastrointestinal stromal tumors (GIST) and GIST type stromal tumor (ST) beyond the gastrointestinal tract. METHODS: A retrospective study was carried out on leiomyoma, leiomyosarcoma and neurilemoma (46 cases in gastrointestinal tract and l3 cases in urinary tract and perineal area). 4 antibodies (CD117, CD34, SMA, S-100) were used for immunohistochemical staining. RESULTS: Among 45 cases of GIST, the positive rate of CD117 and CD34 was 93.3% and 88.9% respectively. Among 12 cases of GIST type ST beyond the gastrointestinal tract, the positive rate of CD117 and CD34 was 83.3% and 75.0% respectively. In 2 cases (1 in gastrointestinal tract) of leiomyomas, both CD117 and CD 34 were negative in tumor cells, while SMA was extensively positive. CONCLUSIONS: CD117 and CD34 positivity are the most valuable factors in diagnosing ST. Both GIST and GIST type ST beyond the gastrointestinal tract are considered originating from a proto-interstitial stem cell with disoriented differentiation.
