Metal-assisted chemical etching (MacEtch) of silicon in oxidizing hydrofluoric acid (HF) solutions has emerged as a prominent top-down micro/nanofabrication approach for a wide variety of silicon micro/nanostructures. The popularity of the process is due to its simplicity, rapidity, versatility, and scalability. In recent years, there has been a surge of interest in developing MacEtch silicon micro/nanostructures for advanced energy conversion and storage applications, such as photovoltaic devices, thermoelectric devices, lithiumion rechargeable batteries, and supercapacitors. Particularly, MacEtch has emerged as a powerful surface micro/nanostructuring method for low-cost and scalable production of commercial black silicon (b-Si) with excellent light trapping properties. This review on MacEtch processing of silicon in oxidizing HF solutions provides a critical description of its history and origin including how it evolved into what it is today, the understanding of its mechanism and important technical advances in the field. As regards MacEtch-fabricated b-Si, its initial discovery and further improvements to its large-scale deployment in silicon photovoltaic industry are traced. Some fundamental challenges and perspectives in this exciting field are also discussed.

Background and PurposeCarotid endarterectomy (CEA) with patch angioplasty produces greater results than with primary closure; however, there remains uncertainty on the optimal patch material in CEA. A systematic review of randomized controlled trials (RCTs) was performed to evaluate the effect of angioplasty using venous patch versus synthetic patch material, and Dacron patch versus polytetrafluoroethelene (PTFE) patch material during CEA.MethodsA multiple electronic health database screening was performed including the Cochrane library, Pubmed, Ovid, EMBASE and Google Scholar on all randomized controlled trials (RCTs) published before November 2012 that compared the outcomes of patients undergoing CEA with venous patch versus synthetic patch. RCTs were included if they compared carotid patch angioplasty with autologus venous patch versus synthetic patch material, or compared one type of synthetic patch with another.ResultsThirteen RCTs were identified. Ten trials, involving 1946 CEAs, compared venous patch with synthetic patch materials. Two trials, involving 400 CEAs in 380 patients, compared Dacron patch with PTFE patch. The hemostasis time in CEA with PTFE patch was significantly longer than with venous patch (P<0.0001), and longer than with Dacron patch (P<0.0001). There was no significant difference of mortality rate, stroke rate, restenosis, and operative time in CEA with venous patch versus synthetic patch material, or in CEA with Dacron patch versus PTFE patch (all P>0.05). One RCT of 95 CEAs in 92 patients compared bovine pericardium with Dacron patch, and demonstrated a statistically significant decrease in intraoperative suture line bleeding with bovine pericardium compared with Dacron patch (P<0.001).ConclusionsThe hemostasis time in CEA with PTFE patch was longer than with venous patch or Dacron patch. The overall perioperative and long-term mortality rate, stroke rate, restenosis, and operative time were similar when using venous patch versus synthetic patch material or Dacron patch versus PTFE patch material during CEA. More data are required to clarify differences between different patch materials.

Contrast-induced encephalopathy (CIE) is a rare complication following percutaneous carotid and coronary interventions, and important diagnostic radiological signs include brain edema and cortical enhancement. In this report, we detail a case of probable CIE in an 84year-old woman following a normal diagnostic coronary angiography (CAG) that involved 20 mL of the low-osmolar, non-ionic monomeric, iodine-based contrast agent iopromide (Ultravist 370). The patient was unconscious and presented with hemiparesis, hemianopia, recurrent seizures, and cardiac and respiratory arrest within minutes to hours following the procedure. Non-contrast computed tomography (CT) of the head showed increased subarachnoid density, cortical enhancement, and brain edema in the right hemisphere. Three days of rehydration, reduction in cranial pressure, and treatment with an anticonvulsant and dexamethasone resulted in a gradual recovery with no neurological deficits. This case highlights that severe neurotoxic symptoms may occur in response to low doses of low-osmolar, nonionic, monomeric contrast agents. This finding is of importance to interventional cardiologists for diagnostic considerations and development of treatment plans.

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Objective B‐line imaging by lung ultrasound (LUS) is a new tool for evaluating subclinical pulmonary congestion. The aim of this study was to explore the prognostic value of B‐line number at admission in predicting symptomatic heart failure (HF) during hospitalization in acute anterior wall STEMI patients. Methods This was a prospective cohort study which consecutively enrolled 96 anterior wall STEMI patients without dyspnea at admission. Pulmonary auscultation, NT‐proBNP test, LUS, and echocardiography were performed within 5 hours after primary PCI. Rale occurrence, plasma NT‐proBNP levels, B‐line number, LVEF, E/e’ were recorded, and their predictive value for HF in‐hospital was analyzed. Results A total of 19 patients developed symptomatic HF. Median B‐line number, NT‐proBNP levels, and E/e’ in the HF group were higher than those of the nonheart‐failure (NHF) group (P < 0.001) while LVEF was lower (P = 0.002). There was no statistical difference in rale occurrence between the two groups. Multivariate logistic regression demonstrated that B‐lines, E/e’, and NT‐proBNP independently predicted HF during hospitalization. According to the area under the ROC curve, the strongest predictor is B‐lines (0.972), followed by NT‐proBNP (0.936) and E/e’ (0.928), and combining the three indicators was better than any single parameter (P = 0.048). B‐line cutoff ≥18 could well predict HF event with specificity and sensitivity of 94.7% and 94.8%, respectively. Conclusion Subclinical pulmonary congestion reflected by B‐lines can independently predict symptomatic HF during hospitalization in patients with anterior wall STEMI, LUS will act as a complementary tool for evaluating cardiac function.