bluuebunny/crossref_metadata_2025 huggingface dataset:
Methicillin-Resistant Staphylococcus aureus Endovascular Infection in a Neonate: Prolonged, Safe, and Effective Use of Daptomycin and Enoxaparin
Authors: Chan Joshua I. , Noor Asif , Clauss Christie , Aggarwal Renu , Nayak Amrita
Published: December 2019

We report on a former 28-week gestation neonate with persistent methicillin-resistant Staphylococcus aureus (MRSA) endocarditis, with a heterozygous Factor V Leiden mutation. The neonate became clinically ill after 1 week of life, with positive blood cultures for MRSA. Echocardiography revealed large thrombi in the inferior vena cava and right atrium. Bacteremia persisted despite removal of umbilical arterial and venous catheters and empiric administration of therapeutic doses of vancomycin (minimum inhibitory concentration [MIC] 2 mg/L) and ceftazidime. To narrow therapy, ceftazidime was discontinued, while gentamicin and rifampin were added. Cultures remained positive and, therefore, linezolid was added, and subsequent blood cultures became negative. Since prolonged linezolid use of 2 weeks or longer carries potential adverse effects, antibiotics were changed to daptomycin, which is bactericidal and recommended for treatment of invasive MRSA infections when vancomycin MICs are ≥2 mg/L to minimize vancomycin treatment failure.

Enoxaparin was initiated, with anti-Xa assay monitoring. A workup for thrombophilia revealed heterozygous Factor V Leiden mutation. Serial echocardiograms demonstrated decreasing size of the thrombi, which were no longer visualized at 2 months of age. Creatinine kinase remained normal. The infant had no seizures on daptomycin. The management of persistent MRSA bacteremia in neonates associated with a large thrombus poses a unique challenge due to the long duration of treatment.

To our knowledge, this is the first case of prolonged and safe daptomycin and enoxaparin use in a preterm neonate. Daptomycin may be considered in cases of clinical failure with vancomycin when a lengthy treatment course is contemplated.
Medication Use in Schools: Current Trends, Challenges, and Best Practices
Authors: Butler Susan M. , Boucher Elizabeth A. , Tobison Jennifer , Phan Hanna
Published: December 2019

There are a significant number of students on maintenance medications for chronic diseases or with diagnoses that may result in medical emergencies requiring administration of medications in school. With passing of legislation in all 50 states allowing self-administration of emergency medications for allergic reactions and asthma, the landscape of medication use in schools is changing. These changes have raised questions about the need for legislation or policy development relating to self-carrying and self-administration of medications for other disease states, undesignated stock of emergency medications, and administration of medications by non-medical personnel. Medication administration in the school setting has become a complex issue, and this review will discuss current legislation related to medication use in schools and provide best practices for administering medications to children and adolescents while at school.
An Overview of Indicators and Indices Used for Urban Mobility Assessment
Authors: Vidović Krešimir , Šoštarić Marko , Budimir Damir
Published: December 2019

The urban mobility is affected by global trends resulting in a growing passenger and freight transport demand. In order to improve the understanding of urban mobility in general, to evaluate mobility services and to quantify the overall transport system performance, it is necessary to assess urban mobility. Urban mobility assessment requires the application of methodology integrating different metrics and explicitly applying a multi-dimensional approach. Since scientific community does not define urban mobility in an unambiguous way, part of this paper is devoted to the analysis of the definition of urban mobility. This step enables better understanding of urban mobility in general, as well as understanding of the urban mobility assessment process. Usually, a three-layered approach that includes urban mobility data, indicators and indices is used for the assessment. Therefore, the aim of this paper was to perform extensive research in order to synthesize, define and organize the elements of those layers. The existing urban mobility indicators and indices have been developed for specific urban areas, taking into account local specifications, and they are not applicable in other cities. Also, the choice of urban mobility indicators is mainly related to the existence of data sources, which limits the objective and comparable assessment of the mobility of cities where such data do not exist.
Pachychoroid Spectrum Disorders: A Review of Clinical Features and Management
Authors: Kumawat Devesh , Bhayana Amber , Kumar Vinod
Published: December 2019

Pachychoroid disorders are an entity distinct from age-related macular degeneration and constitute four major variants along a continuum-pachychoroid pigment epitheliopathy, central serous chorioretinopathy (CSCR), pachychoroid neovasculopathy (PNV), and polypoidal choroidal vasculopathy (PCV). The common characteristics include presence of dilated outer choroidal vessels (pachyvessels), choriocapillaris and retinal pigment epithelium (RPE) attenuation with or without increased choroidal thickness in a focal area or diffuse in topography. Whether choroidal congestion and hyperpermeability is the primary event with consequent choriocapillaris atrophy or choriocapillaris attenuation occurs primarily with resultant compensatory outer choroidal vascular dilatation, remains poorly understood. Chronic choroidal inflammation and ischemia predispose to angiogenic factor release which together with overlying RPE-Bruch’s disruption leads to type 1 choroidal neovascular membrane (CNV) formation. Pachychoroid disorders occur in younger population, does not have multiple soft drusen, and have distinct genetic polymorphisms and favourable treatment response when compared to the age-related macular degeneration. Systemic associations are known to occur with pachychoroid disorders. The treatment is required in cases of CSCR with chronic subretinal fluid and PNV or PCV with CNV and macular exudation. While acute cases of CSCR resolves spontaneously, diffuse epitheliopathy often requires photodynamic therapy or focal laser photocoagulation depending upon the site of RPE leakage. Pachychoroid disorders with exudation from CNV respond to three monthly intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections followed by pro-re-nata treatment. The presence of polyps and branched vascular network in PCV often requires photodynamic therapy instead or in addition to anti-VEGF therapy. Significant advances have occurred in the understanding of this novel spectrum with the help of indocyanine green angiography and optical coherence tomography angiography. However, there remain several areas of uncertainty including the pathogenesis and superiority of the various treatment approaches. Specific therapies aimed at the pathological changes occurring in the pachychoroid disease are the need of future.
Occurrence of Oculo Cardiac Reflex During Strabismus Surgery
Authors: Shalini Gujjula , Chakrapani K. , Harsha Netra , Karanam Sairani , Nambula Srinivasarao
Published: December 2019

Purpose:

To evaluate the occurrence of the oculocardiac reflex (OCR) and its associated risk factors during strabismus surgery at a tertiary referral center.

Methods:

Over a 8 months period, all strabismus surgery candidates were enrolled in the study. OCR was defined as heart rate reduction ≥20% after traction on extraocular muscle(s). The rate of OCR was determined and possible associations were explored. Variables included age, gender, type of strabismus, nature of surgery (weakening versus strengthening), and specified extraocular muscle.

Results:

Eighty four patients with mean age of 17.2 ± 8.7 years were enrolled. OCR occurred in 24 (28.6%) patients, 57 (36.5%) out of 156 operated muscles, and 18 (21.4%) of 23 GA cases. OCR was more common in subjects less than 20 years of age; however, it showed a decreasing trend afterwards. Postoperative nausea and vomiting (PONV) is significantly associated with the occurrence of OCR. OCR was not correlated with gender, type of strabismus, nature of surgery.

Conclusion:

The great majority of patients undergoing strabismus surgery, especially younger subjects, and those undergoing GA experience OCR during surgery.
Oculodigital phenomenon leading to advanced keratoconus in Retinopathy of Prematurity – A case report
Authors: Kumawat Devesh , Sahay Pranita , Goel Siddhi , Kumar Vinod , Chandra Parijat
Published: December 2019

A 14-year-old male child presented with complaints of poor vision in both eyes since infancy. The child had a history of preterm delivery, neonatal intensive care unit stay, and oxygen supplementation. He was diagnosed to have cicatricial Retinopathy of Prematurity [ROP]. Keratoconus was evident in both eyes, along with oculodigital sign and enophthalmos. This case highlights the grave sequelae of untreated ROP and its complications. A varied presentation of ROP is to be borne in mind when evaluating such patients later in life. Oculodigital sign can further compromise the vision in such cases due to associated keratoconus, cataract, and retinal detachment.
Microincision vitrectomy for secondary epiretinal membrane in adult-onset Coats’ disease
Authors: Das Manmath , Chaudhary Priyanka , Varshney Abhishek
Published: December 2019

We report a case of a 20-year-old male who presented with a gradual painless decrease of vision in his left eye. Best-corrected visual acuity (BCVA) was 20/20 in the right eye and 20/200 in the left eye. Anterior segment examination was normal for both eyes. Left eye indirect ophthalmoscopy revealed the presence of a thick epiretinal membrane (ERM) along with telangiectatic vessels and subretinal lipid deposits in inferotemporal quadrant which became more obvious on Fluorescein angiography. Spectral-domain optical coherence tomography (SD-OCT) of left macula revealed a thick ERM with tangential contraction. The patient was diagnosed as adult-onset Coats' disease (Stage 2A) with ERM. The patient underwent standard 25 gauge pars plana vitrectomy with ERM peeling followed by cryotherapy of the telangiectatic vessels. Postoperatively there was a decrease in the amount of subretinal lipid deposition with scarring and obliteration of telangiectatic vessels and BCVA improved to 20/20, N6 which remained stable throughout follow-up.
Ologen in Axenfield-Rieger Anomaly with secondary Glaucoma: A case report with review of literature
Authors: Jain Vaibhav Kumar , Kesarwani Divya , Sharma Kumudini , Kanaujia Vikas , Agarwal Rachna
Published: December 2019

We report a case of Axenfield-Rieger anomaly with secondary glaucoma which was managed with trabeculectomy with adjunctive mitomycin-C and Ologen implant. A 27-year old female who was a known case of glaucoma and was on anti-glaucoma medications for last 24 years, presented with heaviness over left eye. A diagnosis of bilateral Axenfield-Rieger anomaly with secondary angle closure glaucoma was made with right eye controlled on topical anti-glaucoma medications and left eye uncontrolled (30 mm Hg) with anti-glaucoma medications. Patient underwent the above-mentioned surgery in her left eye. The IOP was controlled and bleb was well formed at one year of follow-up. This case report highlights the management of Axenfield-Rieger anomaly with secondary glaucoma with the use of Ologen implant.
Rhino-orbital Mucormycosis Manifesting as Orbital Apex Syndrome with CRAO in An Immunocompetent Patient
Authors: Vallinayagam Muthukrishnan , Balla Shravya Choudhary , Krishnagopal Srikanth , Karthikeyan P. , Sowmya S.
Published: December 2019

Rhino-orbital mucormycosis (ROM) is an uncommon opportunistic infection affecting immunocompromised individuals. Poorly controlled diabetes mellitus is the commonest predisposing factor. A 42-year-old female with well controlled diabetic status, presenting with orbital apex syndrome (OAS) and Central Retinal Artery Occlusion (CRAO) is discussed in this report. There was no evidence of cellulitis, necrotic eschar or facial palsy. There were no features suggesting immunosuppression. The biochemical parameters including blood sugar and electrolytes were normal. Serology for HIV was negative. MRI showed pan sinusitis with thickening and enhancement of extraocular muscles. Urgent debridement of paranasal sinuses was done. Histopathological examination disclosed broad based, filamentous, aseptate hyphae suggestive of mucormycosis. Prompt treatment with systemic Amphotericin B and debridement of sinuses resulted in a favourable outcome. Mucormycosis presents with a constellation of clinical features including ophthalmoplegia, proptosis, ptosis, visual loss, chemosis, nasal discharge, abducens nerve palsy, palatal necrosis, cerebral involvement, hemiparesis and eye lid gangrene. The coexistence of sinus disease with OAS in a diabetic patient should trigger a vigilant search for a fungal etiology, despite the absence of immunosuppression. Microbiological culture may yield negative results and histopathological examination is mandatory. This report emphasizes the rare occurrence of ROM in an immunocompetent diabetic patient with good metabolic control. Early diagnosis and a multidisciplinary approach with intravenous antifungals, adequate sinus drainage and surgical debridement can greatly reduce the morbidity and mortality.
A Rare Case of Ophthalmia Nodosa
Authors: Gaur Aman , Rohatgi Jolly , Srivastava Shachi
Published: December 2019

Ophthalmia Nodosa is an ocular inflammatory response to foreign bodies like insect hair. Initially it manifests as marked lid edema and intense congestion with associated multiple corneal abrasions. Later, entry of insect hair in ocular tissues may result in nodular conjunctivitis, iridocyclitis, vitritis and panophthalmitis. Here, we present a similar case of insect hair in eye with recurrent attacks of conjunctivitis and ophthalmia nodosa which required multiple follow ups of hair removal and later surgical excision of nodular conjunctival lesions containing insect hair.
iTrace – A Ray Tracing Aberrometer
Authors: Sinha Ayushi , Goel Siddhi , Gupta Vinay , Kumawat Devesh , Sahay Pranita
Published: December 2019

Modern ophthalmology focusses on visual quality and not just visual acuity. The quality of vision is affected by both lower and higher order aberrations. An optical aberration is a departure of the performance of an optical system from the prediction of paraxial optics. In this article, we analyse the iTrace Ray-tracing aberrometry and its applications in daily clinical practice. The iTrace system integrates corneal topography with wavefront aberrometry, thereby providing a unique analysis that subtracts corneal from total aberrations in order to isolate the internal aberrations of the eye. It is an extremely useful tool for objective evaluation of dysfunctional lens, improving cataract and refractive surgery outcomes and planning of premium intraocular lenses. Thus, the clinicians must explore this instrument as it is an advanced diagnostic tool that can help the surgeon at all stages of patient care in achieving premium outcomes.
Teaching/Developing Vocabulary Using Think‐Aloud and Read‐Aloud Strategies
Authors: Wolsey Thomas Devere , Lapp Diane
Published: December 2019

Thinking aloud and reading aloud are two instructional practices intended to provide models of proficient language use to listeners. Additionally, early readers are often introduced to many of the conventions of reading such as book handling, print conventions, and language and text structures during a read aloud or a think aloud. While engaging students and fostering learning and academic language development, both strategies are powerful motivational supports for students throughout the grades, especially English learners because they facilitate their hearing academic language produced by a capable reader and speaker. This entry outlines the traditions of thinking aloud and reading aloud and then focuses on the use of these two instructional practices relative to vocabulary development.
Notetaking inTESOL
Authors: Siegel Joseph
Published: December 2019

Notetaking is a complex and multifaceted activity that requires the coordination of several cognitive skills and physical movements under extreme time pressure. With the rise of English for academic purposes (EAP) courses and English medium instruction (EMI), notetaking in the TESOL field has become an important area with its own commercial textbooks, research base, and pedagogic practices. This entry reviews notetaking literature for both first language (L1) and second language (L2) contexts with a focus on intervention studies that involved teachers trialing pedagogic approaches with L2 English learners. Practical steps for notetaking in TESOL for teachers, particularly those involved in EAP or EMI courses, and students are provided.
Mercury in Water
Authors: Gu Baohua , Lu Xia , Johs Alexander , Pierce Eric M.
Published: December 2019

Mercury (Hg) is a global pollutant threatening our water resources and human health. Every one of us contains some levels of Hg or methylmercury (MeHg) in our body from consumption of contaminated food such as fish and rice in some countries. Our understanding of the behavior of Hg in natural aquatic environments is limited because the key factors controlling microbial uptake and conversion of inorganic Hg to neurotoxic MeHg remain obscure. MeHg concentrations in water can bioaccumulate up to eight orders of magnitude in the food chain. Metallic or elemental Hg can evaporate and be transported around the globe, plus it readily undergoes chemical, photochemical, and biological transformations (i.e. oxidation, reduction, methylation, and demethylation) in water and sediments. Natural dissolved organic matter (DOM) plays a critical role in mediating these transformations because of its exceptionally strong binding affinity for Hg and its dual functional roles in reducing and oxidizing Hg. Recent discovery of Hg‐methylation genes has significantly advanced our understanding of MeHg biosynthesis, although the simultaneous degradation of MeHg at low concentrations (i.e. picomolar to nanomolar) by anaerobic and methanotrophic bacteria is also recognized now as a potentially important process for controlling net MeHg production, a key factor that determines Hg concentrations and bioaccumulation in biota. Treatment technologies for Hg removal from water are available, but they are mostly applicable to industrial waste streams and at contamination sites with high Hg concentrations (i.e. micromolar to millimolar). Reductions in Hg human exposure might be achievable by decreasing anthropogenic releases, such as coal combustion, over the long‐term since Hg methylation responds to Hg inputs, particularly to freshly deposited Hg in natural aquatic systems.
Disinfection and Antimicrobial Processes
Authors: Blatchley Ernest R.
Published: December 2019

Disinfection and antimicrobial processes are applied for control of microbial populations in municipal and industrial settings. The central goal of these processes is to limit exposure to waterborne microorganisms that have the potential to adversely affect human populations, the environment, or industrial process equipment. The most commonly applied disinfectants are chlorine and ultraviolet (UV) radiation. The behavior of chlorine‐based disinfection systems is governed by the physical chemistry of chlorine and the basic principles of reactor engineering. In the case of UV‐based systems, the overall process performance is governed by the physical (optical) and (photo)chemical behavior of UV radiation, as well as the fundamental principles of reactor behavior. However, because of the geometric, physical, and photochemical characteristics of UV disinfection systems, the application of basic principles of reactor engineering to these systems differs from analogous applications to chemical disinfection systems.
Microbial Exudates
Authors: Duckworth Owen W.
Published: December 2019

Microbes actively release myriad chemicals into the environment. The compounds impact the chemical environment, biological community, and biogeochemical processes in the immediate vicinity of the cell. This entry describes five operationally defined classes of compounds (e.g. extracellular polymeric substances, metallophores, enzymes, signaling compounds, and antibiotics) that are produced and exuded by microbes. These exudates play diverse roles in adhesion, nutrient uptake, intra‐organism interactions, and microbial ecology. In turn, they have macroscale impacts on ecosystem compositions, water resources, biogeochemical processes, and human health.
Pseudomonas mendocina
: Versatile Remediator from a Versatile Genus
Authors: DuBois Jennifer L.
Published: December 2019

Pseudomonas mendocina
is a ubiquitous, metabolically versatile Gram‐negative γ‐Proteobacterium with properties making it attractive for bioremediation applications. Several sequenced genomes are now available, making it possible to understand the organism's metabolic capabilities and its place in the genus. Efforts aimed at understanding the species, directed toward possible applications in carbon or metal bioremediation, mobilization of iron, or nitrogen oxide reduction, are reviewed.
Rainfall–Runoff Modeling Based on Genetic Programming
Authors: Babovic Vladan , Li Xin , Chadalawada Jayashree
Published: December 2019

The rainfall–runoff process is highly nonlinear, time varying, spatially distributed, and not easily described by simple models. Various models have been developed to simulate this process, including lumped conceptual models, distributed physically based models, and empirical black‐box models. Either conceptual or distributed physically based models require a significant amount of data for calibration and validation, whereas in most cases, it is difficult to collect all the data necessary with sufficient accuracy for such models. Traditional black‐box models such as artificial neural networks provide means to ease the data demands for model calibration and validation; however, the information they provide add little insights for interpretation of the underlying process.

Using data‐driven techniques such asgenetic programming(GP), one can attempt to model the rainfall–runoff process based on available hydrometeorology data. Genetic programming can also be used in combination with conceptual models to discover physically interpretable models or equations describing the physical processes. After a detailed review of the conventional applications of genetic programming in rainfall–runoff modeling, this article introduces a novel scheme of conceptual rainfall–runoff modeling based on GP. A tropical case study is provided as a prototype for illustration.
The Effects of Natural Mineral Coatings on Metal Transport in Contaminated Aquifers
Authors: Singer David M.
Published: December 2019

Natural mineral coatings play an important role in controlling the transport of contaminants in soils and sediments. These materials contain complex mineral and organic components, and their formation, composition, and morphology are dependent on the mineralogical and chemical composition of the underlying grain and local (bio)geochemical conditions. Mineral coatings often have unique chemical and physical properties compared to primary minerals, which can affect their reactivity with respect to contaminant sequestration due to: (i) complex and variable porosity, which allows for limited flow potential within confined pore spaces; and (ii) a more chemically complex mineralogy and therefore type, abundance, and distribution of reactive surface sites. As the source material for mineral coatings can include both external components and material derived from the underlying surface, these materials therefore acts as a record of the recent environmental conditions to which they were exposed. Case studies are presented here highlighting the role that mineral coatings have in affecting the reactive transport of contaminants in near‐surface environments. Future work at the intersection of hydro(geo)logy, mineralogy, and (bio)geochemistry has the potential to yield a more unified understanding of contaminant transport through these complex material across a wide range of spatial regimes.
Community Science andCUAHSI
Authors: Hooper Richard P.
Published: December 2019

The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) was formed in 2002 with support from the US National Science Foundation to design and operate research facilities for the benefit of the academic water research community. Through a series of community meetings, workshops, and pilot projects, four facilities were advanced for possible funding: hydrologic observatories (highly instrumented field sites), a hydrologic measurement facility (to provide and to develop advanced field instrumentation), a data center (to publish, to access, and to provide data), and a national center for hydrologic synthesis (a facility to promote interdisciplinary scholarship in water). Only one of these facilities to support the hydrologic information system succeeded in attracting funding. The mixture of success and failure indicates fundamental challenges for hydrologic science that must be overcome to achieve its potential as a science and to advance scientific management of water resources.
Experimental Investigation of Solute Transport
Authors: McInnis Daniel P.
Published: December 2019

Laboratory column tests are often used to study transport in porous media. The basic principle is simple: solutes are passed through a bed of soil or sediment and measured in the effluent solution. However, complex behaviors within the column can be identified through certain features of the breakthrough curve. Specific aspects of experimental design will vary depending on the objectives of the study, but theoretical and empirical work has yielded a set of guidelines that should be followed for all column tests. This article reviews the theory of miscible solute transport in saturated porous media, outlines key elements of the laboratory setup, and provides a framework for data analysis and interpretation. The reader will receive an overview of the experimental process from beginning to end, and learn the dos and don'ts of column studies.
Rapid Rate Biological Filtration in Drinking Water Treatment
Authors: MacGillivray Meaghan , Stoddart Amina K. , Gagnon Graham A.
Published: December 2019

This article discusses the design and operational criteria that impact rapid‐rate biofiltration performance with a focus on the removal of two contaminants typically found in sources of drinking water: natural organic matter and manganese. Rapid‐rate biofilters must meet particle and substrate treatment goals while maintaining adequate hydraulic performance. These treatment and operational goals can be achieved through practical biofilter design and a thorough monitoring strategy for performance indicators. Key design criteria include consideration of influent water temperature, any pretreatment processes, nutrient availability, media type, contact time, and backwash strategy. Thorough monitoring should include particle removal indicators (e.g. turbidity), substrate removal indicators (e.g. substrate concentration), hydraulic performance indicators (e.g. unit filter run volume) and biomass indicators (e.g. adenosine triphosphate, extracellular polymeric substances).
Application of Nanocomposite Membranes for Non‐Pressure‐Driven Separation Processes
Authors: Brant Jonathan A. , Shahabadi Seyed M.S.
Published: December 2019

The global community grapples with a burgeoning water crisis as a result of exploding urban populations, climate change, and the finite character freshwater supplies. Despite the inherent challenges that this crisis presents, there have been many technological advancements that together give the world a new set of tools by which it may utilize nonfreshwater resources for beneficial purposes. These advancements have come in the form of new membrane‐based desalination processes, forward osmosis (FO), and membrane distillation (MD), which no longer rely on energy‐intensive hydraulic pumping to create freshwater. As such, we are now presented with the ability to desalinate water in more environmentally sustainable manners. In addition, with advancements in material science and nanotechnology we can engineer the properties of membranes to meet the unique requirements of FO and MD processes. Together, these advancements have greatly expanded the types of source waters that can be made potable. This article covers the relevant advancements in these areas to provide the reader with both the tools and the inspiration to create the separation processes of tomorrow that are needed to address the ongoing water crisis.
Utilization of Treated Wastewater for Irrigation of Agricultural Crops
Authors: Chen Yona , Tarchitzky Jorge
Published: December 2019

The application in agriculture of treated wastewater (TWW) is expanding worldwide and in particular in dryland regions such as the Mediterranean region in general and the Middle East in particular. Freshwater, which was formerly directed to agriculture, is increasingly being utilized by the ever‐increasing municipal sector as a result of population increase and improved the standard of living. A major source that can account for the demand in the agricultural sector is TWW. Therefore, the percentage of wastewater that undergoes treatment is constantly increasing. This article will focus on the need to not only increase the quantity of TWW but to thoroughly enhance their quality prior to application. This article will focus on potential adverse effects related to TWW irrigation and will briefly discuss means that can be employed to reduce or avoid their effects. A number of undesired traits are higher in TWW than in their freshwater (FW) source. Of these, the most important ones are (i) organic – suspended and dissolved organic matter (DOM) and micro pollutants; and (ii) inorganic – total soluble salts, sodium, chloride, boron, and heavy metals. All of the above pose a threat to soil quality, as well as to plant and human health.
Analysis of Phosphorus Species in Water
Authors: Packa Vlastimil , Bostan Vadim , Furdui Vasile I.
Published: December 2019

A limiting nutrient for aquatic ecosystems, the natural and anthropogenic sourced phosphorus is present in surface waters. Monitoring of phosphorus in water samples and reduction procedures were developed to minimize the occurrence of harmful algal blooms. Phosphate is the most common phosphorus species in water, being present in anionic form (inorganic phosphate) or attached to a carbon‐based molecule (organic phosphate). Although various methods have been developed for phosphate and total phosphorus analysis, the spectrophotometric and ion chromatographic methods remain the most frequently used. Other methods discussed are based on capillary electrophoresis, inductively coupled plasma coupled to atomic emission spectrometry, electrochemical, and nuclear magnetic resonance techniques. The simultaneous analysis of various phosphorus species was possible by coupling chromatographic separations with mass spectrometry, using either electrospray or inductively coupled plasma ionization.
Arsenic in Water: Speciation, Sources, Distribution, and Toxicology
Authors: Mukherjee* Sritama , Gupte* Tanvi , Jenifer Shantha Kumar , Thomas Tiju , Pradeep Thalappil
Published: December 2019

Arsenic (As), an elemental metalloid, occurs primarily in metallic and sulfide ores. Both natural (e.g. volcanoes, weathering, and leaching) and anthropogenic activities (e.g. mining, wood preservation, etc.) determine its current global distribution. Water sources (particularly groundwater), soil, and air are all likely to contain arsenic‐based species in regions near to the sources. From a human ecology standpoint,Asenters the human body primarily through food (which containsAsvia bioaccumulation) and contaminated water. The World Health Organization (WHO) and leading environmental monitoring agencies have declaredAscontamination as a serious concern. To address concerns,Asmitigation methods have been developed focusing on human beings (primarily using iron‐based supplements), and remediation of waters (primarily throughAsremoval). Ongoing scientific activities in this area include (i) research leading to increased understanding ofAsgeochemistry (e.g. occurrence, mobilization, geochemical cycles); (ii) revisiting water standards in a location‐specific manner; (iii) biochemistry/cellular toxicology, and its use in therapeutics; and (iv) efforts to mitigate impact ofAson humans subjected to chronic exposure. This article provides a comprehensive view of state‐of‐the‐art science and technology regardingAs.
Arsenic in Water: Fundamentals of Measurement and Remediation
Authors: Mukherjee Sritama , Gupte Tanvi , Jenifer Shantha Kumar , Thomas Tiju , Pradeep Thalappil
Published: December 2019

In view of the deleterious environmental and health effects associated with arsenic (As) in water, a number of technologies have been developed to forewarn and assess its concentration. These methodologies range from colorimetric methods to sophisticated biosensors. Even then, affordable and reliable methodologies in the field are yet to evolve. Several methods forAsremoval are available ranging from adsorption to reverse osmosis, but the technology that would get deployed depends on the economic situation of the regions affected. Affordability is the most important parameter limiting the implementation of in‐line and on‐siteAsdetection techniques. On the positive side, from the standpoint of providingAs‐free water, gravity‐fed affordable solutions forAs‐free drinking water are possible with nanomaterials. Such technologies have already been implemented for delivering clean water to 0.6 million people. An overview of all of the developments, including emerging technologies forAssensing and mitigation are presented in this article.
Interception: Its Importance, its Isotopic Impact, and How to Model and Measure it
Authors: Savenije Hubert H.G. , Coenders‐Gerrits Miriam
Published: December 2019

Interception of precipitation by land cover and subsequent evaporation is an essential hydrological process. In the terrestrial hydrological cycle, it is the first process after precipitation. As such, it affects all subsequent processes in the cycle. Not only does interception amount to a considerable part of the total terrestrial evaporation (about 30–35% of total terrestrial evaporation, globally) it also has a considerable impact on terrestrial moisture recycling and isotope fractionation. Furthermore, it facilitates preferential recharge, which is advantageous to ecosystem and water resources, alike. If interception is not conceptualized correctly in hydrological models, then the calibration of runoff processes is negatively affected. This article provides the theoretical background to conceptualizing the interception process, as well as methods to observe and compute interception, illustrated with global distribution maps.
Lake Balaton: Water Quality of the Largest Shallow Lake in Central Europe
Authors: Sebestyén Viktor , Németh József , Juzsakova Tatiana , Domokos Endre , Rédey Ákos
Published: December 2019

The water quality parameters of the fresh water lakes highly depend on the amount of water in the lake, hence on its depth. The shallowest lakes of the world are evaluated, and the largest shallow lake of Central Europe is chosen for the water quality study.

The
Aquatic Environmental Assessment
(
AEA
) technique is briefly summarized, and the method is demonstrated for the period of years between 1990 and 2016. The different water chemistry parameters are studied, and these are represented along the basins of the lake in the function of time. In addition to this, the aquatic environmental indices are calculated on the basis of the parameters. The measured and calculated indices clearly indicate a significant improvement of the lake that is qualified as good–excellent. On the basis of the water balance, the total nitrogen and phosphorous balances are calculated, and recommendations are given on the measures to mitigate the load of the Lake Balaton.
Nanomaterials in Water: Detection and Characterization
Authors: Gondikas Andreas , Wagner Stephan , Navratilova Jana
Published: December 2019

The analysis of engineered nanomaterials in environmental waters is a challenging task because nanomaterials are likely to be released gradually, in low numbers, and diluted into large and mobile water bodies, such as creeks, rivers, lakes, and oceans. While engineered nanomaterials are diluted in these waters, they are also mingled with a multitude of natural particles of various sizes and compositions that together with natural organic substances comprise a complex particulate matrix with regional variations. Dissolved components are also likely to adsorb and react on the nanoparticles surface, thus altering their surface characteristics. Detecting nanomaterials in such complex and dynamic systems requires the combination of several analytical techniques. This article offers an overview of the currently available techniques and provides a generic strategy that can be adjusted according to the characteristics and hydrochemical properties of the water sample.
Principles of Gas Solubility in Water: Henry's Law
Authors: Viadero Roger
Published: December 2019

Henry's law provides a basis to determine the solubility of gases in liquids. Henry found that at a constant temperature, the concentration of a soluble or semi‐soluble gas in a liquid was proportional to the partial pressure of the gas that is in equilibrium with the liquid. The proportionality constant is known as the Henry's law constant (HLC). Henry's law is applicable when there is chemical equilibrium between the gas and liquid phases, temperature is constant, and the solution is dilute (<1% solute concentration).

Data for HLCs are available for a wide range of inorganic as well as organic elements and compounds. To meet the needs of readers who work in many different fields of water science, comprehensive references to HLCs are provided. While HLC data are abundant, the application of this information is complicated by a general lack of uniformity in the way the constants are defined. Consequently, it is critical for those seeking to apply HLC data to fully understand the assumptions used to develop those data. Likewise, consideration must be given to the units in which HLC data are reported.
Arctic Shipping and Polar Seaways
Authors: Babin Julie , Lasserre Frédéric , Pic Pauline
Published: December 2019

Climate change in the Arctic triggered a series of discourses about the opening up of a previously unreachable region. Navigation remains, however, difficult in the Arctic, transits are still very limited, as sea ice is still a major constraint. How did the development policies of both the Northwest Passage and the Northern Sea Route unfold? What are the recent trends in Arctic shipping?
Tidal Efficiency
Authors: Rasmussen Todd C.
Published: December 2019

Water levels in coastal aquifers that fluctuate in rhythm with sea levels can be described using the tidal efficiency, which is the ratio of aquifer‐to‐ocean water‐level fluctuations. Unconfined aquifers that are hydraulically connected to the ocean respond due to water moving across the ocean–aquifer interface, whereas confined aquifers fluctuate due to increased surface loading that physically compresses aquifer pores. Noncoastal aquifers also respond to surface loads (e.g. barometric pressure changes, rainfall, flooding), which is termed
Loading Efficiency
.
Dew Deserts
Authors: Kidron Giora J.
Published: December 2019

With the addition of relatively substantial amounts of water through dew, dew deserts are characterized by relatively lush flora (and fauna) in comparison to deserts that do not receive dew. While facilitating the growth of plants, dew also facilitates the establishment and growth of micro‐ and small organisms, which have in turn a substantial effect of the food chain. The physical conditions that enable dew formation are discussed, as well as its effect upon lithobionts, biocrusts, and plants. Solid data, principally from the Negev Desert, assist to evaluate the role of dew upon the structure and function of dew desert ecosystems.
Nonorthogonal Multiple Access (NOMA): How It Meets 5G and Beyond
Authors: Islam S.M. Riazul , Zeng Ming , Dobre Octavia A. , Kwak Kyung‐Sup
Published: December 2019

Due to massive connectivity and increasing demands of various services and data‐hungry applications, a full‐scale implementation of the fifth‐generation (5G) wireless systems requires more effective radio access techniques. In this regard, nonorthogonal multiple access (NOMA) has recently gained ever‐growing attention from both academia and industry. Compared to orthogonal multiple access (OMA) techniques, NOMA is superior in terms of spectral efficiency and is thus appropriate for 5G and beyond. In this article, we provide an overview of NOMA principles and applications. Specifically, the article discusses the fundamentals of power‐domain NOMA with single and multiple antennas in both uplink and downlink settings. In addition, the basic principles of code‐domain NOMA are elaborated. Further, the article explains various resource allocation techniques such as user pairing and power allocation for NOMA systems; discusses the basic form of cooperative NOMA and its variants; and addresses several opportunities and challenges associated with the compatibility of NOMA with other advanced communication paradigms such as heterogeneous networks and millimeter wave communications.
Apparent Potential Difference Boosting Directional Electron Transfer for Full Solar Spectrum‐Irradiated Catalytic H2 Evolution
Authors: Lin Zhexing , Zhao Yan , Luo Jinhua , Jiang Shujuan , Sun Chuanzhi , Song Shaoqing
Published: December 2019

Directional charge transfer among nanolayers of graphitic carbon nitride (g‐C3N4) is still inefficient because of the interlayer electrostatic potential barrier, which tremendously restricts the utilization of charges in conversion of solar energy into fuel. Herein, an apparent potential among nanolayers is introduced to boost interlayer electron transfer by curving planar g‐C3N4 nanosheets into carbon nitride square tubes (C3N4Ts), and Ni2P nanoparticles as electron acceptors are loaded on C3N4Ts (Ni2P/C3N4Ts) for highly efficient H2 evolution. Study results present H2‐evolution efficiency over the constructed Ni2P/C3N4Ts up to 19.25 mmol g−1 h−1 with a large number of visible H2 bubbles, which is more than 1.9 and 2.6 times of that over g‐C3N4 supported 1 wt%Pt and 3 wt%Pd, respectively. Density functional theory (DFT) and characterizations reveal efficient directional transfer through C3N4T interlayer (001) to Ni2P (111) is achieved under the apparent potential difference of C3N4Ts, which therefore ensures the high H2‐evolution performance of Ni2P/C3N4Ts. These results in the field of material engineering supply a novel strategy to boost directional charge transfer for solar energy conversion efficiency by introducing apparent potential difference.
Non‐Native Block Copolymer Thin Film Nanostructures Derived from Iterative Self‐Assembly Processes
Authors: Demazy Nils , Cummins Cian , Aissou Karim , Fleury Guillaume
Published: December 2019

Nanostructured block copolymer (BCP) thin films constitute an elegant tool to generate complex periodic patterns with periodicities ranging from a few nanometers to hundreds of nanometers. Such well‐organized nanostructures are foreseen to enable next‐generation nanofabrication research with potent applications in the design of functional materials in biology, optics or microelectronics. This valuable platform is, however, limited by the geometric features attainable from diblock copolymer architectures considering the thermodynamic driving force leaning toward the formation of structures minimizing the interface between the blocks. Therefore, strategies to enrich the variety of structures obtained by BCP self‐assembly processes are gaining momentum and this progress report reviews the opportunities inherent to iterative BCP self‐assembly by considering the emerging strategies for the generation of “non‐native” morphologies.
Experimental characterization of liquid film behavior during droplets–polyethylene particle collision
Authors: Ren Xiang , Sun Jingyuan , Huang Zhengliang , Yang Yao , Tian Sihang , Wang Jingdai , Yang Yongrong
Published: December 2019

Nowadays, the droplet–particle collision characteristics in the gas‐phase ethylene polymerization process are still unclear. The high‐speed photography and a quasi‐circle imaging approach are employed to study the collision interaction characteristics between liquid droplets and polyethylene particles. The liquid film evolution is studied through variations of the film thickness on the particle north pole, the dynamic contact angle, center angle and film thickness at the maximum extension. Results have found that for n‐hexane the threshold temperature of the recoil happening increases with increasing initial Weber number, but for 1‐hexene it is stable. Over 70°C evaporation and splash occurs immediately. Under low Weber numbers, the water droplet stays for damping oscillations, the reference stable height of which is linearly related to temperatures. Moreover, three regimes of film thickness variation with time are identified and mathematically described, while Regime 3 characteristics are found strongly dependent on the liquid species, Weber number, and particle temperature.
Visible‐Light‐Induced Difunctionalization of Styrenes: An Efficient and Green Protocol for the Synthesis of β‐Acyloxyselenides
Authors: Chen Jinyang , Chen Rui , Mei Lan , Yan Shanshu , Wu Yan , Li Qiang , Yuan Binfang
Published: December 2019

An efficient and green protocol for synthesizing β‐acyloxyselenides was developed through the visible‐light‐induced difunctionalization of styrenes with a binary system of diaryldiselenides and carboxylic acids under mild reaction conditions, without using any transition‐metal‐catalysts. This protocol is scalable and tolerates a wide spectrum of styrenes and carboxylic acids to deliver the corresponding products in moderate to excellent yields, providing convenient approach to β‐acyloxyselenides.
Transition‐Metal‐Free Approaches to Arylsulfones using Benzylic Ammonium Salts through C−N Bond Cleavage
Authors: Liu Yishuai , Zhu Haibo , Yang Liu , Xie Zongbo , Jiang Guofang , Le Zhang‐Gao , Tu Tao
Published: December 2019

A transition‐metal‐free approach to benzyl sulfones by using sodium sulfinates and benzyl ammonium salts is described. The protocol provides a simple and direct method to realize the C−N bond cleavage in the presence of readily available Cs2CO3. During the reaction process, a range of functional groups with respect to both sodium sulfinates and benzylic ammonium salts were well compatible, leading to various benzyl sulfones in moderate to good yields.