Corrosion behavior of pure metals(Ni and Ti)and alloys(316H SS and GH3535)in liquid GaInSn

In this study,the interactions between a Ga-based liquid metal,GaInSn,and several metal materials,including pure metals(Ni and Ti)and alloys(316H stainless steel(SS)and GH3535),at 650℃were investigated.The aim was to evaluate the corrosion performance and select a suitable candidate material for use as a molten salt manometer diaphragm in thermal energy storage systems.The results indicated that the alloys(316H SS and GH3535)exhibited less corrosion than pure metals(Ni and Ti)in liquid GaInSn.Ga-rich binary intermetallic compounds were found to form on the surfaces of all the tested metal materials exposed to liquid GaInSn,as a result of the decomposition of liquid GaInSn and its reaction with the constituent elements of the metal materials.The corrosion mechanism for all the tested materials exposed to liquid GaInSn was also investigated and proposed,which may aid in selecting the optimal candidate material when liquid GaInSn is used as the pressure-sensing medium.

Effect of thermal exposure time on tellurium-induced embrittlement of Ni–16Mo–7Cr–4Fe alloy

The embrittlement of nickel-based structural alloys by fission-produced tellurium(Te) is a major challenge for molten salt reactors(MSR). In this study, the effects of thermal exposure time on tellurium diffusion in a candidate MSR structural alloy(Ni–16 Mo–7 Cr–4 Fe) and the consequent mechanical property degradation of the alloy were investigated through surrogate diffusion experiments at 700 °C. The results show that some tellurium reacted with the alloy to form tellurides on the surface,while some tellurium diffused into the alloy along grain boundaries. Ni_3Te_2 and CrTe were the most stable reaction products at the tested temperature, and the formation of CrTe on the surface induced the Cr depletion at grain boundaries of the alloy. The diffusion depth of Te increased gradually with thermal exposure time, and thediffusion rate kept stable within the test duration of up to3000 h. The Te diffusion in the alloy caused the embrittlement of grain boundaries, inducing crack formation and strength degradation in tensile test at room temperature.

Epidemiological Features of Nontraumatic Spontaneous Subarachnoid Hemorrhage in China： A Nationwide Hospital-based Multicenter Study

Background：Nontraumatic spontaneous subarachnoid hemorrhage （SAH） is associated with a high mortality.This study was conducted to investigate the epidemiological features of nontraumatic spontaneous SAH in China.Methods：From January 2006 to December 2008,the clinical data of patients with nontraumatic SAH from 32 major neurosurgical centers of China were evaluated.Emergent digital subtraction angiography （DSA） was performed for the diagnosis of SAH sources in the acute stage of SAH （≤3 days）.The results and complications of emergent DSA were analyzed.Repeated DSA or computed tomography angiography （CTA） was suggested 2 weeks later if initial angiographic result was negative.Results：A total of 2562 patients were enrolled,including 81.4% of aneurysmal SAH and 18.6% of nonaneurysmal SAH.The total complication rate of emergent DSA was 3.9% without any mortality.Among the patients with aneurysmal SAH,321 cases （15.4%） had multiple aneurysms,and a total of 2435 aneurysms were detected.The aneurysms mostly originated from the anterior communicating artery （30.1%）,posterior commtmicating artery （28.7%）,and middle cerebral artery （15.9%）.Among the nonaneurysmal SAH cases,76.5% （n =365） had negative initial DSA,including 62 cases with peri-mesencephalic nonaneurysmal SAH （PNSAH）.Repeated DSA or CTA was performed in 252 patients with negative initial DSA,including 45 PNSAH cases.Among them,the repeated angiographic results remained negative in 45 PNSAH cases,but 28 （13.5%） intracranial aneurysms were detected in the remaining 207 cases.In addition,brain arteriovenous malformation （AVM,7.5%）,Moyamoya disease （7.3%）,stenosis or sclerosis of the cerebral artery （2.7%）,and dural arteriovenous fistula or carotid cavernous fistula （2.3%） were the major causes of nonaneurysmal SAH.Conclusions：DSA can be performed safely for pathological diagnosis in the acute stage of SAH.Ruptured intracranial aneurysms,AVM,and Moyamoya disease are the major causes of SAH detected by emergent DSA in China.

Effect of Surface Decarburization on Corrosion Behavior of GH3535 Alloy in Molten Fluoride Salts

Corrosion test of a Ni–16Mo–7Cr alloy with a decarburized layer was conducted in FLiNaK salt at 700 °C. A detailed microstructure study was performed to investigate the corrosion behavior and mechanisms. The results show that the Ferich layers were formed on the corroded alloys with and without decarburization. The surface decarburization had little influence on the corrosion resistance of the alloy, whereas it caused more M_2C carbide formation beneath the corrosion layer. That is attributed to the higher concentration of C gradient near the alloy surface, which was resulted from the increase in C content liberated from graphite crucible wall during the corrosion process.

The cannabis paradox:contrasting role for marijuana in cardiovascular disease

In a recent study published in Cell,Wei and colleagues describe the role of canabis in mediating inflammation and oxidative stress induced endothelial dysfunction and thereby contributing to the pathogenesis of atherosclerosis.1 Cardiovascular diseases(CVDs)are still the leading cause of death globally.There is an estimated 17.9 million people died from CVDs in 2019,representing 32%of all global deaths.2 Cannabis,also known as hemp or marijuana,is the most widely cultivated,trafficked and abused illicit drug worldwide especially in Western countries.