Interaction-Dependent Interfacial Charge-Transfer Behavior in Solar Water-Splitting Systems.

Dual-band-gap systems are promising for solar water splitting due to their excellent light-harvesting capability and high charge-separation efficiency. However, a fundamental understanding of interfacial charge-transfer behavior in the dual-band-gap configuration is still incomplete. Taking CdS/reduced graphene oxide (CdS/RGO) nanoheterojunctions as a model solar water splitting system, we attempt here to highlight the interaction-dependent interfacial charge-transfer behavior based on both experimental observations and theoretical calculations. Experimental evidence points to charge transfer at the CdS-RGO interface playing a dominant role in the photocatalytic hydrogen production activity. By tuning the degree of reduction of RGO, the interfacial interaction, and, thereby, the charge transfer can be controlled at the CdS-RGO interface. This observation is supported by theoretical analysis, where we find that the interfacial charge transfer is a balance between the effective single-electron- and hole-transfer probability and the surface free electron and hole concentration, both of which are related to the surface potential and tailored by interfacial interaction. This mechanism is applicable to all systems for solar water splitting, providing a useful guidance for the design and study of heterointerfaces for high-efficiency energy conversion.

Facile Integration between Si and Catalyst for High-Performance Photoanodes by a Multifunctional Bridging Layer.

Designing high-quality interfaces is crucial for high-performance photoelectrochemical (PEC) water-splitting devices. Here, we demonstrate a facile integration between polycrystalline n+p-Si and NiFe-layered double hydroxide (LDH) nanosheet array by a partially activated Ni (Ni/NiOx) bridging layer for the excellent PEC water oxidation. In this model system, the thermally deposited Ni interlayer protects Si against corrosion and makes good contact with Si, and NiOx has a high capacity of hole accumulation and strong bonding with the electrodeposited NiFe-LDH due to the similarity in material composition and structure, facilitating transfer of accumulated holes to the catalyst. In addition, the back illumination configuration makes NiFe-LDH sufficiently thick for more catalytically active sites without compromising Si light absorption. This earth-abundant multicomponent photoanode affords the PEC performance with an onset potential of ∼0.78 V versus reversible hydrogen electrode (RHE), a photocurrent density of ∼37 mA cm-2 at 1.23 V versus RHE, and retains good stability in 1.0 M KOH, the highest water oxidation activity so far reported for the crystalline Si-based photoanodes. This bridging layer strategy is efficient and simple to smooth charge transfer and make robust contact at the semiconductor/electrocatalyst interface in the solar water-splitting systems.

Vertically Aligned Porous Organic Semiconductor Nanorod Array Photoanodes for Efficient Charge Utilization.

Because of inefficient charge utilization caused by localized π-electron conjugation and large exciton binding energy, the photoelectrochemical water-splitting efficiency of organic polymers is seriously limited. Taking the graphitic carbon nitride (g-CN) polymer as an example, we report a novel photoanode based on a vertically aligned g-CN porous nanorod (PNR) array prepared in situ, using a thermal polycondensation approach, with anodic aluminum oxide as the template. The g-CN PNR array exhibits an excellent photocurrent density of 120.5 µA cm-2 at 1.23 VRHE under one sun illumination, the highest reported incident photon-to-current efficiency of ∼15% at 360 nm, and an outstanding oxygen evolution reaction stability in 0.1 M Na2SO4 aqueous solution, which constitutes a benchmark performance among the reported g-CN-based polymer photoanodes without any sacrificial reagents. When compared with its planar counterpart, the enhanced performance of the PNR array results principally from its unique structure that enables a high degree of aromatic ring π-electron conjugation for higher mobility of charge carriers, provides a direct pathway for the electron transport to the substrate, produces a large portion of hole-accepting defect sites and space charge region to promote exciton dissociation, and also withstands more strain at the interface to ensure intimate contact with the substrate. This work opens a new avenue to develop nanostructured organic semiconductors for large-scale application of solar energy conversion devices.

Achromobacter pneumonia in a patient with advanced COPD, a diagnostic challenge.

Bacterial pneumonia causes significant morbidity and mortality especially in elderly and immunocompromised hosts. Achromobacter xylosoxidans denitrificans pneumonia is very rarely reported. However, the reported cases have been in patients who are either immunocompromised or have bronchiectasis. We hereby present a unique case of Achromobacter xylosoxidans denitrificans pneumonia in an immunocompetent patient with advanced chronic obstructive pulmonary disease (COPD). Our patient is a Caucasian male admitted with shortness of breath, fever and cough. Chest X-ray demonstrated right-sided infiltrates and he was treated with intravenous ceftriaxone and azithromycin. He was discharged home on oral amoxicillin-clavulanate 875-125 mg two times per day for a total of 7 days. Patient returned to emergency room after 5 weeks with persistent symptoms and chest X-ray revealed persistent right-sided infiltrate and sputum culture showed Achromobacter xylosoxidans denitrificans. The patient was started on oral levofloxacin 750 mg one time per day for 2 weeks with resolution of symptoms.

Transcending boundaries: Unleashing the potential of multi-organ point-of-care ultrasound in acute kidney injury.

Acute kidney injury (AKI) is a clinical syndrome characterized by a rapid increase in serum creatinine levels or a decrease in urine output or both. In spite of thorough history-taking, physical examination, and laboratory analysis, there are limitations in the diagnostic process and clinical monitoring of AKI. Point-of-care ultrasonography (POCUS), a limited ultrasound study performed by clinicians at the bedside, has emerged as a valuable tool in different clinical settings. In this discussion, we explore the potential of POCUS performed by nephrologists to address specific questions encountered in the diagnosis and management of AKI patients. POCUS not only aids in excluding hydronephrosis but also provides real-time insights into hemodynamics, enabling formulation of individualized treatment plans. Further studies are required to assess the impact of multi-organ POCUS on pragmatic patient outcomes related to AKI, as well as its potential in risk stratification and identification of different levels of AKI severity and pathophysiological signatures.

Autoimmune Heparin-Induced Thrombocytopenia: A Diagnostic and Management Challenge After Transcatheter Aortic Valve Replacement.

Heparin-induced thrombocytopenia (HIT) is a commonly encountered condition, especially in inpatient settings, and is often attributed to high mortality and prolonged hospital stays. A rare entity, autoimmune heparin-induced thrombocytopenia (aHIT) refers to a condition in which antiplatelet factor-4 (PF4) antibodies activate platelets even in the absence of heparin. Our patient presented 12 days after transcatheter aortic valve replacement (TAVR) with altered mental status and severe thrombocytopenia. Further work-up revealed acute thromboembolic cerebrovascular accident (CVA), and the HIT antibody was positive. He was started on intravenous argatroban infusion with poor response. Platelet factor-4 antibodies were positive as well, and he was started on intravenous immunoglobulins (IVIG) therapy resulting in platelet recovery. This case is a reminder to consider autoimmune HIT, especially when platelet count fails to improve with conventional therapy.

iELMNet: Integrating Novel Improved Extreme Learning Machine and Convolutional Neural Network Model for Traffic Sign Detection.

Traffic sign detection (TSD) in real-time environment holds great importance for applications such as automated-driven vehicles. Large variety of traffic signs, different appearances, and spatial representations causes a huge intraclass variation. In this article, an extreme learning machine (ELM), convolutional neural network (CNN), and scale transformation (ST)-based model, called improved extreme learning machine network, are proposed to detect traffic signs in real-time environment. The proposed model has a custom DenseNet-based novel CNN architecture, improved version of region proposal networks called accurate anchor prediction model (A2PM), ST, and ELM module. CNN architecture makes use of handcrafted features such as scale-invariant feature transform and Gabor to improvise the edges of traffic signs. The A2PM minimizes the redundancy among extracted features to make the model efficient and ST enables the model to detect traffic signs of different sizes. ELM module enhances the efficiency by reshaping the features. The proposed model is tested on three publicly available data sets, challenging unreal and real environments for traffic sign recognition, Tsinghua-Tencent 100K, and German traffic sign detection benchmark and achieves average precisions of 93.31%, 95.22%, and 99.45%, respectively. These results prove that the proposed model is more efficient than state-of-the-art sign detection techniques.

Anaphylactic Shock as a Rare Side Effect of Intravenous Amiodarone.

Amiodarone is a very commonly used antiarrhythmic agent. However, it has a wide variety of systemic side effects as well as many hypersensitivity and allergic reactions, ranging from angioedema to anaphylactic shock in patients who have iodine allergies. We present a rare and unique case of an 86-year-old female who developed anaphylactic shock from intravenous (IV) amiodarone. She had no reported allergies to iodine or iodinated contrast. She had a history of chronic persistent atrial fibrillation and was being maintained on oral amiodarone as an outpatient. She was admitted with shortness of breath and was found to have atrial fibrillation with rapid ventricular response. She was started on an IV amiodarone bolus. Immediately after a few milliliters of infusion, she complained of shortness of breath, with facial flushing and generalized blanching erythema, followed by severe hypotension and cardiopulmonary arrest. IV amiodarone infusion was suspected to be the culprit and was discontinued immediately. IV epinephrine 0.3 mg was administered, followed by the advanced cardiovascular life support (ACLS) protocol for cardiopulmonary arrest. She did not respond to the standard ACLS protocol and continued to remain in cardiopulmonary arrest. A spot diagnosis of anaphylactic reaction to IV amiodarone was made, and she was started on IV epinephrine infusion 0.1 µg/kg/minute, and immediate return of spontaneous circulation was achieved. She was started on IV methylprednisolone 125 mg, IV famotidine 20 mg, and IV diphenhydramine 25 mg. She was intubated and required mechanical ventilation. She was successfully extubated later and safely discharged, receiving oral metoprolol 25 mg for rate control and PO rivaroxaban 20 mg once daily. Anaphylactic shock from IV amiodarone administration is a potentially fatal complication observed in patients with prior reported allergies to iodine or iodinated contrast media. It has rarely been reported in the absence of prior allergy to iodine or iodinated contrast media. Prompt recognition by clinicians is prudent for early diagnosis and appropriate treatment.

Role of Vasodilator Therapy in Acute Heart Failure.

Over the past decade, several trials have questioned the efficacy of vasodilator therapy in acute heart failure (AHF) in the absence of uncontrolled hypertension. In this article, we provide a unique review of the most valuable four trials that present the role of vasodilator therapy in the management of patients with AHF. These four trials have evaluated the efficacy of different types of vasodilators such as nesiritide, ulatritide, and serelaxin in the setting of AHF. Also, we compared comprehensive vasodilator therapy versus standard therapy to see if there is any effect on mortality and re-hospitalization.