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Objective: Despite endovascular advances in fenestrated and branched devices, thoracic endovascular aortic repair (TEVAR) for arch pathologies remains challenging. The aim of this study was to provide a contemporary review on the current evidence for in situ fenestration during TEVAR and to evaluate its short- and mid-term clinical outcome in the management of arch pathology.Methods: A systematic literature review on in situ fenestration of thoracic aortic stent-graft from January 2003 to September 2018 was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.Results: Our initial search yielded 169 studies, of which 21 articles were relevant to the topic and were finally included. One hundred and forty-five in situ fenestration procedures in 99 patients were reviewed, involving 25 innominate arteries (17%), 33 left common carotid arteries (23%) and 87 left subclavian arteries (60%). Twelve patients (12/99, 12%) had two-vessel fenestration and three-vessel fenestration was performed in 17 patients (17/99, 17%). Technical success was achieved in 136 arteries (136/145, 93%). Talent/Valiant with monofilament twill woven polyester fabric was the most common (50/99, 51%) stent-graft used for fenestration. Three methods reported for in situ fenestration were needle, laser and radiofrequency. Needle was the most frequently used device for fenestration, which was performed in 60 patients (60/99, 61%). Three patients (3/99, 3%) died with 30 days, none were in situ fenestration TEVAR procedure-related. Perioperative complications including one (1%) retrograde type A aortic dissection, two (2%) type II endoleaks, and three (3%) strokes were reported. The pooled estimate for overall technical success, perioperative mortality and stroke was 88.3% (95% CI, 78.6%-93.9%), 5.9% (95% CI, 2.5%-13.4%) and 9.5% (95% CI, 4.1%-20.6%), respectively. Four patients (4/96, 4%) died during follow-up, none were aortic-related. All the fenestration bridging stents were reportedly patent, with only 1 (1/96, 1%) asymptomatic left subclavian stent stenosis. Two patients (2/96, 2%) with type II endoleak from left subclavian artery required secondary intervention.Conclusion: In situ fenestration appeared to be a feasible and effective method to extend proximal landing zone during TEVAR. It had an acceptable short-term result with high technical success and low fenestration related morbidity. Long-term durability data were lacking, and there was no high level evidence to recommend the routine use of in situ fenestration TEVAR for the management of arch pathology. [ABSTRACT FROM AUTHOR]

Thermomigration (TM) in Sn58Bi solder was detected in Cu/Sn58Bi/Ni solder joints supplied with direct current. Thermal electric finite-element simulation showed that a thermal gradient of 527 °C/cm existed in a solder joint when a current density of 5×103 A/cm2 was applied to the structure at 50 °C. Depending on the direction of the current, TM was found to assist or counteract electromigration (EM) on the diffusion of Bi atoms. The atomic fluxes of Bi induced by EM and TM were estimated separately. EM-enhanced cross interaction between Cu and Ni across the solder joint was also detected, which led to the intermetallic compound (IMC) at Ni side or the Cu side of the joint that electron flow was from the Cu side to the Ni side is thinner than that of corresponding IMC in the joint stressed with current in opposite direction. For the joint as reflowed, the IMC at the Ni side was (Cu,Ni)6Sn5 instead of Ni3Sn4 and the IMC at the Cu side was Cu6Sn5 without Ni atoms contained. When Ni wire set as anode, the IMC at the Ni side was still (Cu,Ni)6Sn5 even after the joint was stressed for 384 h. However, it turned into (Ni,Cu)3Sn4 if Ni wire set as cathode. Regardless of the directions of the electric current, the IMC at the Cu side was Cu6Sn5 at all time. For the joint that Cu wire set as anode, the growth of Ni3Sn4 at the cathode side was enhanced by EM and TM, while the growth of Cu6Sn5 at the anode side was retarded. [ABSTRACT FROM AUTHOR]

The thermomigration behavior of eutectic tin-lead flip chip solder joints at an ambient temperature of 150 °C was investigated in terms of microstructural evolution, atomic transport, and numerical simulation. Pb accumulation and phase separation were observed in solder joints near a melting temperature after 50 h, which was supported by energy dispersive x-ray and element mapping analysis. It is believed that Pb atoms migrated from the chip side (the hot side) to the substrate side (the cold side) under a temperature gradient. Thermal electrical finite element simulation for the real flip chip test structure showed the existence of a temperature difference between the substrate side and the chip side. In addition, a temperature gradient above 1000 °C/cm across the adjacent unpowered solder joints was predicted. This was also verified by temperature measurements with thermocouples. The atomic flux of Pb due to thermomigration was calculated here, which was agreeable with the values originally reported. Also, the driving force of thermomigration was estimated to be 10-17 N, even approaching the same order with that of electromigration under a current density of 104 A/cm2. [ABSTRACT FROM AUTHOR]

Systematic experimental work was carried out to understand the growth kinetics of Ni3Sn4 at the Sn–3.5Ag solder/Ni interface. Sn–3.5%Ag solder was reflowed over Ni metallization at 240 °C for 0.5 min and solid-state aging was carried out at 150–200 °C, for different times ranging from 0 to 400 h. Cross-sectional studies of interfaces have been conducted by scanning electron microscopy and energy dispersive x ray. The growth exponent n for Ni3Sn4 was found to be about 0.5, which indicates that it grows by a diffusion-controlled process even at a very high temperature near to the melting point of the SnAg solder. The activation energy for the growth of Ni3Sn4 was determined to be 16 kJ/mol. [ABSTRACT FROM AUTHOR]

The dissolution of thin film under-bump-metallization (UBM) by molten solder has been one of the most serious processing problems in electronic packaging technology. Due to a higher melting temperature and a greater Sn content, a molten lead-free solder such as eutectic SnAg has a faster dissolution rate of thin film UBM than the eutectic SnPb. The work presented in this paper focuses on the role of 0.5 wt % Cu in the base Sn–3.5%Ag solder to reduce the dissolution of the Cu bond pad in ball grid array applications. We found that after 0.5 wt % Cu addition, the rate of dissolution of Cu in the molten Sn–3.5%Ag solder slows down dramatically. Systematic experimental work was carried out to understand the dissolution behavior of Cu by the molten Sn–3.5%Ag and Sn–3.5%Ag–0.5%Cu solders at 230–250 °C, for different time periods ranging from 1 to 10 min. From the curves of consumed Cu thickness, it was concluded that 0.5 wt % Cu addition actually reduces the concentration gradient at the Cu metallization/molten solder interface which reduces the driving force of dissolution. During the dissolution, excess Cu was found to precipitate out due to heterogeneous nucleation and growth of Cu[sub 6]Sn[sub 5] at the solder melt/oxide interface. In turn, more Cu can be dissolved again. This process continues with time and leads to more dissolution of Cu from the bond pad than the amount expected from the solubility limit, but it occurs at a slower rate for the molten Sn–3.5%Ag–0.5%Cu solder. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This article reviews the poisoning epidemiology in Hong Kong, assessment and treatment of acute poisoning, and management of acute psychiatric medication overdose. In 2016, nearly 4000 poisoning cases involving approximately 6000 poisons were reported to Hong Kong Poison Information Centre. About 25% of the poisons involved were psychiatric-related medications. The initial medical assessment on poisoning includes history taking, vital signs monitoring, and focused physical examination. Approaches in managing acute poisoning include supportive measures, decontamination, antidote use, and enhanced elimination. Management on overdose of psychiatric medications (zopiclone, tricyclic antidepressants, selective serotonin reuptake inhibitor, antipsychotics, valproic acid, lithium, and methylphenidate) are discussed with practical tips highlighted. [ABSTRACT FROM AUTHOR]

Aim We present the clinical outcomes of patients who underwent delayed (>30 days) open surgical repair after endovascular aortic aneurysm repair. Methods All patients receiving delayed open repair of infrarenal and juxtarenal aortic aneurysms after endovascular repair from July 2001 to December 2017 were retrospectively reviewed. Patients' baseline characteristics, indications for delayed open conversion, and time between endovascular repair and open conversion are described. Early outcomes included operative approach, morbidity, and mortality. Midterm outcomes included survival. Results Twenty-two (3.3%) of 667 patients with prior infrarenal endovascular aortic aneurysm repair had delayed open conversion (20 elective and 2 emergency). The time from endovascular repair to open conversion was 60 ± 36 months. The indications were 6 (27%) type Ia endoleaks, 6 (27%) type II endoleaks with enlarging sac size, 2 (9%) endotensions, 7 (32%) unknown types of endoleak, and 1 (5%) graft infection. The 7 minutes unknown endoleaks were confirmed as lumbar leaks in 4 cases and fabric leaks in 3. Operative time was 222 ± 48 min with blood loss of 2211 ± 2057 mL. Hospital stay after conversion was 12 ± 8 days. There was no 30-day mortality. Estimated survival rates were 96%, 91%, 86%, 79% and 57% at 1, 2, 3, 4, and 5 years postoperatively. Conclusion Delayed conversion to open surgery after endovascular aortic aneurysm repair by endograft explantation appears to be safe with good short- and mid-term outcomes. With careful preoperative assessment, open conversion remained a realistic and viable option in patients with failed endovascular treatment. [ABSTRACT FROM AUTHOR]

Bovine aortic arch is known to be associated with an increased rate of aortic arch expansion. The most frequently observed human variant of bovine aortic arch is a common origin of the innominate trunk and left common carotid artery. This is a report of two patients who had successful custom-made arch branch endograft treatment for an arch aneurysm associated with bovine arch anomaly. Modular endovascular repair of aortic arch aneurysms using an inner-branched device adds to the armamentarium of treatment options, and is a minimally invasive management modality without the need for sternotomy or intraoperative extracorporeal bypass. [ABSTRACT FROM AUTHOR]

Laser-induced fluorescence (LIF) spectra of the A–X system of the LiH isotopes, excited by the UV lines of an argon and a krypton ion laser, were observed and analyzed. Three long LIF series of different LiH isotopes were taken with a 3.4 m high resolution spectrograph. The results were combined with previous experimental data to study the breakdown of the Born–Oppenheimer approximation in the X 1Σ+ electronic ground state of the isotopic LiH molecules. Using a quantum mechanical variational method, potential energy curves of the four LiH isotopes were extended almost up to the dissociation limits. [ABSTRACT FROM AUTHOR]