bluuebunny/crossref_metadata_2025 huggingface dataset:
Proton irradiation effect on thermoelectric properties of nanostructured n-type half-Heusler Hf0.25Zr0.75NiSn0.99Sb0.01
Authors: Kempf Nicholas , Karthik Chinnathambi , Jaques Brian J. , Gigax Jonathan , Shao Lin , Butt Darryl P. , He Ran , Wang Dezhi , Ren Zhifeng , Zhang Yanliang
Published: June 2018

Thermoelectric properties of nanostructured half-Heusler Hf0.25Zr0.75NiSn0.99Sb0.01 were characterized before and after 2.5 MeV proton irradiation. A unique high-sensitivity scanning thermal microprobe was used to simultaneously map the irradiation effect on thermal conductivity and Seebeck coefficient with spatial resolution less than 2 μm. The thermal conductivity profile along the depth from the irradiated surface shows excellent agreement with the irradiation-induced damage profile from simulation. The Seebeck coefficient was unaffected while both electrical and thermal conductivities decreased by 24%, resulting in no change in thermoelectric figure of merit ZT. Reductions in thermal and electrical conductivities are attributed to irradiation-induced defects that act as scattering sources for phonons and charge carriers.
Electron reflection effects on particle and heat fluxes to positively charged dust subject to strong electron emission
Authors: Vignitchouk L. , Delzanno G. L. , Tolias P. , Ratynskaia S.
Published: June 2018

A new model describing dust charging and heating in unmagnetized plasmas in the presence of large electron emission currents is presented. By accounting for the formation of a potential well due to trapped emitted electrons when the dust is positively charged, this model extends the so-called OML+ approach, thus far limited to thermionic emission, by including electron-induced emission processes, and in particular low-energy quasi-elastic electron reflection. Revised semi-analytical formulas for the current and heat fluxes associated with emitted electrons are successfully validated against particle-in-cell simulations and predict an overall reduction of dust heating by up to a factor of 2. When applied to tungsten dust heating in divertor-like plasmas, the new model predicts that the dust lifetime increases by up to 80%, as compared with standard orbital-motion-limited estimates.
Refractive index sensing using a light trapping cavity: A theoretical study
Authors: Kumar Samir , Das Ritwick
Published: June 2018

A refractive index sensor is proposed comprising one-dimensional photonic bandgap geometry in conjunction with a thin metal film. The refractive index sensor is based on the cavity mode formed in a thin cavity layer sandwiched between multilayers of SiO2/Ta2O5 and a metal film. The cavity structure traps light through excitation of the cavity mode and hence sharp resonance minima (maxima) are obtained in the reflection (transmission) spectrum. Our theoretical model investigates the impact of cavity thickness, nature of plasmon-active metal, the angle of incidence, and polarization of light on the sensitivity. It is found that the resonance wavelength increases linearly as the analyte refractive index increases. Additionally, the enhancement in the interaction between the analyte medium and micro-cavity mode-field further enhances the sensitivity of the proposed sensor. It is observed that as the cavity thickness increases from 200 nm to 900 nm, the sensitivity increases from 200 nm/RIU to 350 nm/RIU. The performance of the proposed photonic crystal based sensor exhibits strong polarization and angular dependences. Also, the sharp micro-cavity resonance results in improved detection accuracy as compared to surface plasmon resonance based schemes. The proposed structure advantage is an alternative to the conventional surface plasmon refractive index sensor.
Ultrasonic rheology of visco-elastic materials using shear and longitudinal waves
Authors: Lefebvre Gautier , Wunenburger Régis , Valier-Brasier Tony
Published: June 2018

We present a technique for determining the rheology of visco-elastic materials in the ultrasonic frequency range based on the measurement of the longitudinal and shear waves reflected and transmitted by a slab of material with a controlled thickness sandwiched between two delay lines. The high sensitivity of this Fabry-Pérot resonator-based technique allows one to access characteristic relaxation times associated with visco-elasticity. As a useful application of the technique, we characterize the Olympus SWC-2 shear-wave couplant in the 0.7–5 MHz frequency range.
Single-bunch imaging of detonation fronts using scattered synchrotron radiation
Authors: Nielsen Michael H. , Hammons Joshua A. , Bagge-Hansen Michael , Lauderbach Lisa M. , Hodgin Ralph L. , Champley Kyle M. , Shaw William L. , Sinclair Nicholas , Klug Jeffrey A. , Li Yuelin , Schuman Adam , van Buuren Anthony W. , Watkins Erik B. , Gustavsen Richard L. , Huber Rachel C. , Willey Trevor M.
Published: June 2018

A centimeter-scale field of view for transmission X-ray radiography from a sub-millimeter-focused synchrotron X-ray beam is achieved by placing a strongly scattering material upstream of the sample. Combining the scattered beam with a detector system synchronized and gated to acquire images from single X-ray pulses provides the capability for time-resolved observations of transient phenomena in samples larger than the native X-ray beam. Furthermore, switching between this scatter-beam imaging (SBI) and scattering modes is trivial compared to switching between unfocused white beam imaging and scattering using a focused pink beam. As a result, SBI additionally provides a straightforward method to precisely align samples relative to the focused X-ray beam for subsequent small-angle X-ray scattering measurements. This paper describes the use of glassy carbon for SBI to observe phenomena during detonation of small-scale high explosive charges and compares the technique to conventional white beam imaging. SBI image sequences from ideal versus non-ideal explosive materials provide insights into the evolution of dead zones of the undetonated material, while tomographic reconstructions of radiographs acquired as the detonation front traverses the explosive charge can provide a means for estimating the density at and behind the detonation front.
The potential relaxation instability in a helicon plasma
Authors: Desjardins T. R. , Gilmore M.
Published: June 2018

High positive grid biasing (>10Te) in a large-scale helicon plasma at the University of New Mexico has led to the excitation of large fluctuations (>50%) in ion saturation current and floating potential at a low frequency (100–300 Hz). These fluctuations have been identified as an instability and have been studied under a variety of conditions, including variations in the bias voltage, magnetic field strength, and the length of the plasma column. A series of measurements with Langmuir probes has been used to analyze the characteristics of the fluctuations. The instability has been found to travel predominately along the axis with a speed of 1–3cs, where cs is the ion sound speed. The frequency of the mode is found to be dependent on the bias voltage. Increasing the grid bias leads to an increase in the frequency until a second critical voltage causes the fluctuations to disappear. The magnetic field and plasma length are found to affect the amplitude of the mode and the voltage range over which it exists. This mode has been identified as the potential relaxation instability.
Dynamics analysis of the hybrid powertrain under multi-frequency excitations with two time scales
Authors: Hu Donghai , Yan Yanzhi , Xu Xiaoming , Wang Jing
Published: June 2018

Aiming at the dynamic behavior of hybrid powertrain under multi-frequency excitations with two time scales, this paper has carried out related research work. A nonlinear dynamic model of hybrid powertrain is established by taking engine excitation, load excitation and electromagnetic excitation into consideration. Considering the order gap between the excitation frequency and the natural frequency, slow variables are introduced to transform this model into a fast-slow model. Through introducing the De Moivre equation, slow variables are unified into a single one. The dynamic equations under different excitation frequencies and amplitudes are obtained. Bifurcation theory is applied to study the bifurcation behavior when the equilibrium point is unstable, and the conditions for the generation of fold bifurcation are derived. By means of numerical analysis, the influence of excitation frequency and amplitude on dynamics behavior is investigated by curve of equilibrium point, transformed phase portrait and time history. The simulation results show that fold bifurcation may lead to jumping phenomenon of the system trajectory and bursting oscillation is generated correspondingly. Additionally, the bifurcation characteristics of the hybrid powertrain may change with the excitation frequency and amplitude, making the pattern of bursting oscillation more complicated. The conclusion provides a reference for further analysis of dynamic behavior of hybrid powertrain.
Current-driven domain wall motion along ferromagnetic strips with periodically-modulated perpendicular anisotropy
Authors: Sánchez-Tejerina Luis , Alejos Óscar , Raposo Víctor , Martínez Eduardo
Published: June 2018

The dynamics of magnetic domain walls along ferromagnetic strips with spatially modulated perpendicular magnetic anisotropy are theoretically studied by means of micromagnetic simulations. Ferromagnetic layers with a periodic sawtooth profile of the anisotropy depict a well-defined set of energy minima where the walls are pinned in the absence of external stimuli, and favor the unidirectional propagation of domain walls. The performance of the current-driven domain wall motion along these ratchet-like systems is compared to the field-driven case. Our study indicates that the current-driven domain wall motion exhibits significant improvements with respect to the field-driven case in terms of bit shifting speed and storage density, and therefore, it is suggested for the development of novel devices. The feasibility of these current-driven ratchet devices is studied by means of realistic micromagnetic simulations and supported by a one-dimensional model updated to take into account the periodic sawthooth anisotropy profile. Finally, the current-driven domain wall motion is also evaluated in systems with a triangular modulation of the anisotropy designed to promote the bidirectional shifting of a series of walls, a functionality that cannot be achieved by magnetic fields.
Increase in depolarization temperature and improvement in ferroelectric properties by V5+ doping in lead-free 0.94(Na0.50Bi0.50)TiO3-0.06BaTiO3 ceramics
Authors: Verma Anita , Yadav Arun Kumar , Kumar Sunil , Srihari Velaga , Rajput Parasmani , Reddy V. Raghavendra , Jangir Ravindra , Poshwal Himanshu K. , Liu Shun Wei , Biring Sajal , Sen Somaditya
Published: June 2018

A detailed study was carried out to investigate the effects of poling on structure, vibrational, dielectric, and ferroelectric properties of donor-doped (V5+ at Ti4+-site) lead-free Na0.47Bi0.47Ba0.06Ti(1-x)VxO3, (x = 0, 0.01, and 0.03) ceramics fabricated via a modified sol-gel method. Rietveld refinement of synchrotron radiation source powder x-ray diffraction data showed that unpoled samples are in rhombohedral R3c phase whereas poled samples showed a mix rhombohedral R3c and tetragonal P4mm phases at ambient temperature, due to a long-range order established in lattice system after poling. V+5 doping increases the rhombohedral distortion in unpoled and poled samples while it reduces the tetragonality in poled samples. Vibrational study revealed that unpoled samples have more lattice disorder compared to poled samples. X-ray absorption near edge spectroscopy measurement confirmed that Ti and V are in 4+ and 5+ oxidation states, respectively, for all poled and unpoled samples. The average grain size was found to decrease from 5.6 ± 0.5 μm for x = 0 to 1.0 ± 0.2 μm for x = 0.03. Depolarization temperature was found to increase significantly in poled samples from ∼104 °C for undoped sample to 150 °C for the sample with 1% vanadium substitution. Drastic improvements in ferroelectric and dielectric properties are explained in terms of structural changes. High remnant polarization Pr ∼ 31.4 μC/cm2 and moderately low coercive field Ec ∼ 20 kV/cm have been observed at an applied electric field of ∼35 kV/cm for the sample with 1% vanadium substitution which makes it an attractive candidate for ferroelectric applications.
Nonlinear multi-fields coupled model of magnetoelectric coefficient and sensitivity in bilayer ME sensor
Authors: Zhou Hao-Miao , Wu Yun-Ning , Hong Yin-Qiu , Zhou Yun , Wei Jing
Published: June 2018

Aiming to design magnetostrictive/piezoelectric asymmetric bilayer laminate structure that is commonly used in magnetoelectric (ME) sensor, a bilayer static nonlinear magneto-mechanical- electro-thermal coupled theoretical model which is about calculating ME coefficient and sensitivity is established. This model is based on the mechanical-electric linear constitutive relation of piezoelectric layer and one-dimension nonlinear thermal-magneto-mechanical constitutive relation of giant magnetostrictive material (GMM), in which the bending deformation caused by asymmetric structure has also been considered. The model shows universal applicability in the magnetostrictive/piezoelectric bilayer ME structure. In order to verify the validity of the model, magnetostrictive Terfenol-D and piezoelectric PZT are selected to constitute bilayer asymmetric ME composite structure sample, whose static ME coefficient is measured under different temperatures and bias magnetic fields. The model is degenerated to the ME coefficient model without stress, which shows a good predicted result being qualitatively and quantitatively consistent with experimental result confirming the validity of the model. Therefore, the nonlinear effects of pre-stress, bias magnetic field and environmental temperature, thickness ratio, as well as different piezoelectric materials on the ME coefficient and sensitivity were systematically investigated with our established model. The predicted result provides a roadway to improve static ME coefficient and sensitivity of devices by selecting different physic fields, materials, and thickness ratio for designing future ME sensors.
Circadian rhythms of factors involved in luteal regression are modified in p55 tumour necrosis factor receptor (TNFRp55)-deficient mice
Authors: de la Vega Magali del C. , Delsouc María B. , Ponce Ivana , Ragusa Vicente , Vallcaneras Sandra , Anzulovich Ana C. , Casais Marilina
Published: June 2018

The rhythm of factors involved in luteal regression is crucial in determining the physiological duration of the oestrous cycle. Given the role of tumour necrosis factor (TNF)-α in luteal function and circadian regulation and that most of the effects of TNF-α are mediated by p55 TNF receptor (TNFRp55), the aims of the present study were to analyse the following during the luteal regression phase in the ovary of mice: (1) whether the pattern of expression of progesterone (P4) and the enzymes involved in the synthesis and degradation of P4 is circadian and endogenous (the rhythm persists in constant conditions, (i.e., constant darkness) with a period of about 24 hours); (2) circadian oscillations in clock gene expression; (3) whether there are daily variations in the expression of key genes involved in apoptosis and antioxidant mechanisms; and (4) the consequences of TNFRp55 deficiency. P4 was found to oscillate circadianally following endogenous rhythms of clock factors. Of note, TNFRp55 deficiency modified the circadian oscillation in P4 concentrations and its enzymes involved in the synthesis and degradation of P4, probably as a consequence of changes in the circadian oscillations of brain and muscle ARNT-Like protein 1 (Bmal1) and Cryptochrome 1 (Cry1). Furthermore, TNFRp55 deficiency modified the circadian rhythms of apoptosis genes, as well as antioxidant enzymes and peroxidation levels in the ovary in dioestrus. The findings of the present study strengthen the hypothesis that dysregulation of TNF-α signalling may be a potential cause for altered circadian and menstrual cycling in some gynaecological diseases.
Diffusiophoresis of charged colloidal particles in the limit of very high salinity
Authors: Prieve Dennis C. , Malone Stephanie M. , Khair Aditya S. , Stout Robert F. , Kanj Mazen Y.
Published: June 2018

Significance

Contact between low- and high-salinity water occurs in many applications including enhanced oil recovery (EOR), desalination by reverse osmosis, or electric-power production (“blue energy”) by pressure-retarded osmosis. The resulting salinity gradients can propel particles which cause fouling of osmosis membranes. In EOR the gradient can transport functionalized nanoparticles into the porous oil-bearing rock. Once transported, the nanoparticles undertake in situ sensing and intervention activities in the rock. At very high salinity, the long-range interaction needed for diffusiophoresis or electrophoresis of charged particles is expected to vanish. Nonetheless, we observed measurable speeds at salinities approaching saturation.
A disordered acidic domain in GPIHBP1 harboring a sulfated tyrosine regulates lipoprotein lipase
Authors: Kristensen Kristian K. , Midtgaard Søren Roi , Mysling Simon , Kovrov Oleg , Hansen Lars Bo , Skar-Gislinge Nicholas , Beigneux Anne P. , Kragelund Birthe B. , Olivecrona Gunilla , Young Stephen G. , Jørgensen Thomas J. D. , Fong Loren G. , Ploug Michael
Published: June 2018

Significance

Dietary fats absorbed by intestinal enterocytes are packaged into chylomicrons, which circulate in the bloodstream until docking along capillary endothelial cells, primarily in striated muscle and adipose tissue. There, a functional unit composed of lipoprotein lipase (LPL) and GPIHBP1 hydrolyzes the triglycerides in chylomicrons, releasing free fatty acids for use by surrounding parenchymal cells. The current study describes the interactions between LPL and GPIHBP1 and describes how a disordered region of GPIHBP1 results in order and functional stability within LPL. The elucidation of LPL–GPIHBP1 interactions sheds light on the regulation of intravascular triglyceride processing and provides insights into plasma triglyceride metabolism in health and disease.
SPATA7 maintains a novel photoreceptor-specific zone in the distal connecting cilium
Authors: Dharmat Rachayata , Eblimit Aiden , Robichaux Michael A. , Zhang Zhixian , Nguyen Thanh-Minh T. , Jung Sung Yun , He Feng , Jain Antrix , Li Yumei , Qin Jun , Overbeek Paul , Roepman Ronald , Mardon Graeme , Wensel Theodore G. , Chen Rui
Published: June 2018

Photoreceptor-specific ciliopathies often affect a structure that is considered functionally homologous to the ciliary transition zone (TZ) called the connecting cilium (CC). However, it is unclear how mutations in certain ciliary genes disrupt the photoreceptor CC without impacting the primary cilia systemically. By applying stochastic optical reconstruction microscopy technology in different genetic models, we show that the CC can be partitioned into two regions: the proximal CC (PCC), which is homologous to the TZ of primary cilia, and the distal CC (DCC), a photoreceptor-specific extension of the ciliary TZ. This specialized distal zone of the CC in photoreceptors is maintained by SPATA7, which interacts with other photoreceptor-specific ciliary proteins such as RPGR and RPGRIP1. The absence of Spata7 results in the mislocalization of DCC proteins without affecting the PCC protein complexes. This collapse results in destabilization of the axonemal microtubules, which consequently results in photoreceptor degeneration. These data provide a novel mechanism to explain how genetic disruption of ubiquitously present ciliary proteins exerts tissue-specific ciliopathy phenotypes.
Posttraumatic Stress Disorder
Authors: Stoddard Jr Frederick J. , Benedek David M. , Milad Mohammed R. , Ursano Robert J.
Published: June 2018

Posttraumatic stress disorder (PTSD) affects people of all ages and backgrounds and causes persistent suffering and impaired function, but its diagnosis offers the opportunity for early intervention. It is the subject of intensive developmental, epidemiological, genetic/genomic, translational, neurobiological, neuropsychological, and psychological research, and emerging computational methods with “big data,” statistical modeling, and machine learning are likely to accelerate this research. The findings from research on PTSD are changing education and the ways clinicians practice, offering the hope for improved care of those experiencing traumatic stress. Those at particular risk for PTSD include children and adolescents, women, soldiers, refugees and survivors of genocide, sexual orientation minorities, racial and ethnic minorities, patients with burns, injuries and medical trauma, and victims of rape, violence, accidents, and disasters. This chapter provides an overview of PTSD, covering Diagnostic and Statistical Manual of Mental Disorders (fifth edition) diagnostic criteria, epidemiology, neurochemistry and neurobiology, biological and psychological models, assessment, and treatment.
Epidemiology of Trauma- and Stressor-Related Disorders
Authors: Benedek David M.
Published: June 2018

This chapter begins with a review of the epidemiology of traumatic exposure (i.e., what is known about the prevalence of traumatic experience in the general population and other more specific subpopulations). It goes on to highlight the epidemiology of the specific Diagnostic and Statistical Manual of Mental Disorders (fifth edition [DSM-5]) trauma and stressor-related disorders (TSRDs) that may be diagnosed in adults: posttraumatic stress disorder (PTSD), acute stress disorder (ASD), and adjustment disorder. Most epidemiologic studies of TSRD have been based on pre-DSM-5 diagnostic definitions. But these studies must inform current clinical practice until new data emerges. In addition, much more attention has been devoted to the epidemiology of PTSD than to ASD—and even less has been devoted to the epidemiology of adjustment disorder or its specific subtypes. After highlighting the results of epidemiologic studies to date, the chapter concludes with a discussion of areas for further inquiry.
Device-Based Treatment for PTSD
Authors: Lo Meng-chen , Marin Marie-France , Widge Alik S. , Milad Mohammed R.
Published: June 2018

Device-based neuromodulation is an emerging tool with great potential for significant scientific and clinical implications for a number of mental disorders. Neuromodulation techniques deliver electro-magnetic pulses into the brain via invasive or noninvasive electrodes, with various timing and stimulation parameters. The stimulation is thought to work as a “brain pacemaker” that either activates or inactivates targeted brain regions to restore normal homeostasis. There have been significant recent efforts to explore the clinical utility of device-based approaches for the treatment of mood, anxiety disorders, and to a limited extent posttraumatic stress disorder (PTSD). This chapter outlines the scientific underpinnings and rationale for various device-based treatments of PTSD, highlights positive results of studies in other mental disorders, and summarizes the limited clinical data related specifically to the treatment of PTSD and other trauma- and stressor-related disorders to date.
Trauma- and Stress-Related Issues in the Workplace
Authors: Flynn Brian
Published: June 2018

This chapter explores the impact that trauma and stress have on the workplace, and, conversely, how the workplace impacts trauma and stress. It focuses mainly on the role of physicians but is also applicable to disciplines such as psychologists, social workers, and others. The chapter examines some of the major challenges and opportunities that workplaces—and physicians working in and with them—face with regard to mental disorders, including stress and trauma. These issues include the range of factors contributing to the reduction or exacerbation of mental disorders, providing creative and positive leadership in addressing these issues, and developing a variety of issues to enhancing mental health and preventing mental disorders.
Ethical Issues in the Forensic Assessment of Posttraumatic Symptoms
Authors: Howe Edmund G.
Published: June 2018

This chapter examines the core challenges and questions that forensic psychiatrists may encounter when making determinations of factors such as criminal responsibility and disability. It begins by addressing considerations that trauma-related symptoms and behaviors might raise in all legal contexts, for example, whether all the diagnostic criteria should be required to render diagnosis in a medico-legal assessment. It then discusses ethical and legal questions that may arise during evaluation for criminal responsibility and disability. It also considers the idea that, although psychiatrists conducting forensic exams have historically viewed themselves as adopting a different allegiance (i.e., to the state or the court), they might instead seek to find ways to retain their first loyalty to patients. Arguments justifying such alteration and examples of where—if not how—this might be operationalized are noted in the final section of this chapter.
Future Directions in Clinical Care, Research, and Nosology
Authors: Stoddard Jr Frederick J. , Benedek David M. , Milad Mohammed R. , Ursano Robert J.
Published: June 2018

The science of the study of trauma and stress has accelerated as never before, due to increased recognition of the need, greater capabilities for the research, and expanding knowledge. The increased understanding of underlying mechanisms of psychopathology may lead to better diagnostics that are biologically based and to improving the development of novel therapeutics, especially in device-based neurotherapeutics. Similarly, a greater understanding of the neurobiology of trauma- and stressor-related disorders is shifting its nosology towards a dimensional rather than categorical approach. While the acceleration of scientific discovery is exciting, much more is still needed to address the global burden of trauma and stress across all age groups. While history suggests that trauma and stressors surely lie ahead for our society, it also reminds us that our knowledge, understanding, and hope will continue to foster advances for those who need care.
Medical Evaluation of the Bariatric Surgery Patient
Authors: Cetin Derrick
Published: June 2018

Evaluation of the obese patient requires identification of all comorbidities and health conditions, including underlying cardiac and pulmonary conditions that could have a negative outcome on noncardiac surgery. Once comorbidities have been recognized, aggressive optimization of these medical conditions can provide improved outcomes after bariatric surgery. Estimating medical risk can be performed by several validated classification systems. The preoperative checklist and clinical practice guidelines (CPG) were updated in 2013. The CPG recommendations for preoperative evaluation of the bariatric surgery patient include lab testing, nutritional screening, endocrine assessment, and cardiopulmonary assessment, including sleep apnea screening. The CPG suggest an extensive multidisciplinary team approach to the preoperative bariatric surgery patient. Finally, the medical evaluation includes an algorithm for a seven-step approach to the preoperative visit. Also recommended for evaluation of the morbidly obese patient is an algorithm that uses a five-step approach after a comprehensive history and physical exam and lab testing.
Medical Complications of Bariatric Surgery
Authors: Cetin Derrick
Published: June 2018

The medical complications after bariatric surgery vary based on the procedure performed. Medical complications should be considered at specific phases after surgery. The various stages are: phase one (1 to 6 weeks), phase two (7 to 12 weeks), and phase three (13 weeks to 12 months). The various complications at each phase are discussed in this chapter, along with strategies to prevent postoperative complications. Finally, this chapter emphasizes the importance of the multidisciplinary postoperative evaluation of all bariatric surgery patients. The evaluation includes monitoring for health conditions as the patient loses weight, including hypertension, diabetes, sleep apnea, and hyperlipidemia. Monitoring the trajectory of weight loss, screening for micronutrient deficiencies, monitoring proper macronutrient intake, and assessment for development of late surgical complications are included in the multidisciplinary postoperative evaluation at all phases of follow-up.
Bariatric Surgery and Acute Cardiovascular Complications in the ICU
Authors: Khanna Ashish K. , Mathur Piyush
Published: June 2018

The increased numbers of bariatric surgical procedures worldwide have translated into a higher number of postoperative intensive care unit (ICU) admissions. The pathophysiologic perturbations in obesity mean that a large fraction of bariatric surgical patients have both diagnosed and undiagnosed underlying coronary artery disease, hypertension, cardiac rhythm disturbances, and baseline cardiac dysfunction. Manifestations of cardiac complications in this patient population are usually extremely subtle, both intraoperatively under anesthesia and in the ICU during the immediate postoperative period. Furthermore, the patients’ poor physiologic reserve does not allow for periods of hypoperfusion secondary to cardiovascular insufficiency. It is incumbent on the intensivist taking care of these patients to develop a specific skill set focused on early identification of cardiovascular complications in the postoperative period. This chapter highlights some specific cardiovascular complications in bariatric surgery patients, management of the complications, and recommendations for prevention, with a focus on some pertinent surgery-specific issues.
Management of Surgical Complications after Gastric Bypass
Authors: Andalib Amin , Khorgami Zhamak , Rogula Tomasz G. , Schauer Philip R.
Published: June 2018

This chapter discusses the main issues with a selected group of surgical complications after Roux-en-Y gastric bypass. The main focus is on diagnosis and management of anastomotic leak and stricture, marginal ulcers, and gastrogastric fistulas. Anastomotic leak is one of the most feared and potentially catastrophic complications. The most common site is at gastrojejunostomy. Avoiding devascularization of the gastric pouch, creating a tension-free anastomosis, and performing an intraoperative anastomotic leak test are crucial technical points in preventing leaks. Once the leak is highly suspected or diagnosed, it needs to be managed swiftly. Different surgical techniques have different anastomotic stricture rates, with circular staplers being associated with the highest frequency of strictures at the gastrojejunostomy. Endoscopic dilatations are the mainstay of treatment.
Intestinal Complications of Roux-en-Y Gastric Bypass
Authors: Helling Kevin D. , Shikora Scott A.
Published: June 2018

Roux-en-Y gastric bypass is a commonly performed bariatric operation, but it is a formidable procedure performed in technically challenging, medically high-risk patients. Although it is highly successful for achieving meaningful and durable weight loss, a variety of intestinal complications may occur. These include small bowel obstructions from a number of sources (internal hernias, adhesions, intussusception, incisional hernias, intestinal volvulus), anastomotic strictures, dumping syndrome, portal vein thrombosis, Roux-en-O construction, and small bowel diverticulitis. This chapter reviews several of the more commonly occurring postoperative intestinal complications. Clinicians need to understand the signs and symptoms of these complications and must be able to quickly diagnose the condition and initiate treatment.
Management of Laparoscopic Sleeve Gastrectomy Staple-Line Leak
Authors: Huaco Jorge A. , Lo Menzo Emanuele , Szomstein Samuel , Rosenthal Raul J.
Published: June 2018

Laparoscopic sleeve gastrectomy (LSG) has rapidly become the preferred procedure in bariatric surgery. Because of the increased intraluminal pressure and the presence of an intact pylorus, leaks after LSG have a tendency to perpetuate and become chronic. The management of leaks depends primarily on the clinical presentation of the patient, but a leak’s location and chronicity also play a significant role in management. In general, patients with hemodynamic instability need to be treated aggressively and expeditiously with surgical intervention, whereas more stable patients can undergo less-invasive interventions, such as percutaneous drainage and an endoscopic approach. However, once the leak becomes chronic, the role of endoscopic and percutaneous approaches is uncertain, and often more radical surgical intervention is required. Among the surgical options for chronic leaks, Roux-en-Y mucosa-to-mucosa anastomosis and proximal gastrectomy with Roux-en-Y reconstruction have delivered durable results, with acceptable complication rates.
Prevention and Management of Complications of Gastric Banding
Authors: Fielding Christine Ren , Sethi Monica
Published: June 2018

Laparoscopic adjustable gastric banding (LAGB) is an effective option for the treatment of severe obesity. Its longstanding history has allowed us to understand its advantages, limitation, complications, and management. LAGB continues to have an excellent perioperative safety record but can have delayed complications due to the nature of being a device. By understanding these complications, the clinician can easily identify, treat and prevent their occurrence. The most common complications of gastric prolapse with band slippage, device breakdown and weight loss failure can all be addressed conservatively or surgically. This chapter addresses in a systematic format the short- and long-term complications of gastric banding.t
Complications of Jejunoileal Bypass
Authors: Menon Ashok , Khwaja Haris A.
Published: June 2018

Jejunoileal bypass (JIB) was a malabsorptive bariatric procedure developed in the 1950s based on pioneering work in canine models. All described variants involved anastomosis between the proximal jejunum and terminal ileum. Long-term weight loss and improvement in hyperlipidemia were found to be particularly impressive. However, it became clear by the 1980s that morbidity and mortality associated with JIB were unacceptably high. The procedure was abandoned, and many patients underwent reversal to normal intestinal continuity, or revision to other bariatric procedures. Two main mechanisms underlie the complications with JIB. Malabsorption caused excessive diarrhea, nutritional and metabolic failure, and hyperoxaluria, leading to urolithiasis. Bacterial overgrowth in the defunctioned small intestine was thought to lead to immune complex-mediated development of inflammatory arthritis, and the so-called bypass enteritis syndrome. A combination of these two mechanisms was thought to be responsible for hepatic dysfunction and failure after JIB.
Medicolegal Issues in Bariatric Surgery
Authors: Saxton James W. , Budak Amanda R. , Finkelstein Maggie M.
Published: June 2018

Bariatric surgery is more of a service business than any other surgical specialty. From the medicolegal perspective, the risk of a complication becoming a lawsuit can be mitigated by focusing on the relationship with the patient, addressing patient expectations with specific documentation, and prompt, clear communication if a complication occurs. Studies show that when a patient complaint or dissatisfaction is coupled with an adverse event, the patient is more likely to sue. This chapter reviews the current bariatric surgery liability environment and explains how recent changes in the healthcare and liability landscapes have and will continue to affect surgical practice. The chapter introduces three important strategies to increase engagement with your bariatric surgery patient and concurrently impact your liability risk: Five-Star Service, second-generation informed consent form and process, and post-adverse event communication.
Pregnancy Physiology
Authors: Miller Lauren A. , Towner Mary N.
Published: June 2018

This chapter discusses the complex physiologic changes that take place in the immune and nervous system of the pregnant patient. Shifts in cellular production and function as well as the dramatic alterations in hormone concentrations observed in pregnancy are described. The chapter also reviews the current understanding of the major gestational hormones’ roles within the immune and nervous system. We will also summarize the current state of knowledge regarding the physiologic effects of pregnancy, focusing on the effects of estrogen, progesterone, and prolactin on the female immune system and central and peripheral nervous systems. Whenever possible, the clinical relevance of such immunologic and neurologic adaptations to pregnancy will be highlighted.
Pregnancy and Epilepsy
Authors: Tollefson Trenton , Liu Lynn
Published: June 2018

Epilepsy is the fourth most common neurologic disorder behind migraine, stroke, and Alzheimer’s disease. The Center for Disease Control (CDC) data estimates about 3.4 million people in the United States have active epilepsy. Approximately 1 million women of childbearing age in the United States have epilepsy, and about 2 to 5 infants of 1000 pregnancies are born to mothers with epilepsy. Therefore, providers should consider additional aspects of epilepsy care unique to women with epilepsy (WWE) of childbearing age such as planning for and care during pregnancy; concern how epilepsy may affect pregnancy and how pregnancy may impact seizure control. Fortunately, more than 90% of pregnant WWE will give birth to healthy infants. Providers should maintain these important items in mind when caring for a WWE of child-bearing age. This chapter focuses on the effects of pregnancy on seizures and the effects of seizures on pregnancy in pregnant WWE.
ADHD genetics
Authors: Langley Kate
Published: June 2018

This chapter reviews the evidence suggesting that there is a strong genetic component to ADHD and the efforts to identify the specific genetic factors that might be involved. It discusses the different types of genetic contributions, from common to rare variants, and the evidence that these are involved in the aetiology of the disorder. An overview of the methodological strategies employed, including genome-wide association studies (GWAS), polygenic risk score, and copy number variant (CNV) analyses, is undertaken, as well as discussion of the strengths and pitfalls of such work. The contradictory findings in the field and controversies that arise as a result are also explored. Finally, this chapter considers how the heritability of ADHD and specific genetic factors involved need to be examined in the context of clinical factors such as comorbidity and how these factors affect investigations into the genetics of ADHD.
ADHD in adults
Authors: Kooij Sandra , Asherson Philip , Rösler Michael
Published: June 2018

In this chapter, the diagnostic assessment of ADHD in adults is described, starting with the clinical picture, such as the symptoms and the areas of impairment. To start the diagnostic process, screening instruments may be used. During diagnostic assessment, collateral information and neuropsychological tests have their role. The assessment of frequently occurring comorbidity with other psychiatric disorders, such as mood, anxiety, sleep, personality, and autism spectrum disorders, as well as addiction, is necessary to complete the clinical picture. Also, differential diagnosis is part of the diagnostic process. Finally, the Diagnostic Interview for ADHD in adults (DIVA 2.0), and the Conners Adult ADHD Diagnostic Interview (CAADID) are described and discussed. Instructions for use of the DIVA are given. The adjustments in the DSM-5 criteria for ADHD, and the next edition of DIVA based on the DSM-5 criteria, DIVA-5, are described.
Behavioural interventions for preschool ADHD
Authors: Daley David , Oord Saskia Van der
Published: June 2018

The evidence supporting the validity and stability of ADHD during the preschool years is now considerable and, coupled with mounting evidence indicating long-term impairments and economic cost of ADHD, provides a clear rationale for early intervention during the preschool years. While medication is an evidenced-based intervention for older children with ADHD, higher side effects and lower levels of efficacy in preschool children make medication a less attractive option. This chapter presents the behavioural treatment options available for preschool children with ADHD and reviews the evidence base supporting their use, focusing on ADHD, conduct problems, school readiness, parenting behaviour, and parental wellbeing as outcomes. Mediators and moderators of behavioural treatments for preschool children are evaluated, with a focus on the lack of clear mediation and moderation evidence. Finally, important clinical and service delivery considerations are explored, including specialist versus generic types of behavioural interventions, mode of intervention delivery, and dose effects.
ADHD and transitions to adult mental health services
Authors: Hollis Chris
Published: June 2018

Despite the recognition of ADHD as a lifespan neurodevelopmental disorder, the majority of young people with ADHD fail to transition successfully to adult services. Health service transition marks a particularly vulnerable time for young people with ADHD, as disengagement from services and untreated ADHD lead to serious adverse psychiatric and social outcomes. Barriers to successful transition include the lack of adult ADHD services, differences in acceptance thresholds, lack of knowledge and training among practitioners in adult services, and a less family-orientated culture in adult services that may exclude parents. Young people and parents should routinely be involved in the design and evaluation of services related to transition. The role of an ADHD transition worker and increased involvement of primary care in the management of ADHD is recommended to provide greater continuity and support before and after the transfer of care from child and adolescent to adult mental health services.
Treatment in adult ADHD
Authors: Asherson Philip , Ramos-Quiroga Josep Antoni
Published: June 2018

The treatment of ADHD in adults is very similar to that recommended for children and adolescents. There have been many more clinical trials evaluating the efficacy and safety of the drugs used in ADHD treatment on children than adults. Pharmacotherapy for adults with ADHD has been shown to be effective. The National Institute of Health and Care Excellence (NICE) guidelines recommend pharmacotherapy as first-line treatment for adult ADHD. The NICE guidelines consider stimulants (methylphenidate and dexamfetamine) as the first choice for treatment of adult ADHD, and the non-stimulant atomoxetine as a second-line treatment option, followed by other non-stimulant medications such as bupropion and tricyclic antidepressants. This recommendation is in line with European Consensus as determined by the European Network of Adult ADHD. Psychological treatment programmes have been developed implementing psychoeducation, cognitive–behavioural therapy, dialectical behaviour therapy, and mindfulness. Typically, psychological treatments have been added to drug treatment.
The next steps
Authors: Coghill David , Zuddas Alessandro , Rohde Luis Augusto , Banaschewski Tobias
Published: June 2018

ADHD has been heavily researched and over the past few years this has resulted in many important advances in our understanding of this complex disorder and its management. There are, however, still many unanswered questions. Here we outline several of the key challenges facing the field and offer suggestions about potentially important future lines of research. The discussion is organized around several key topics: diagnosis, epidemiology, course, aetiology, and treatment issues. Key themes include a need for smarter, stronger, and innovative study designs across all aspects of the field and a particular need for well-designed longitudinal studies. We need greater collaboration, not just across disciplines with integration of basic and clinical science, but also between researchers and their clinical colleagues, and with patients and their families and the broader community.
Behavioural co-morbidities in epilepsy
Authors: Cavanna Andrea E.
Published: June 2018

The association between epilepsy and specific behavioural co-morbidities has long been recognized. The most common and clinically significant psychiatric disorders reported by patients with epilepsy encompass affective, anxiety, and psychotic symptoms. Behavioural co-morbidities in epilepsy can be classified according to the temporal relationship with seizures—inter-ictal, peri-ictal (pre-ictal, ictal, post-ictal), and para-ictal symptomatology. Antiepileptic drugs (AEDs) can modulate behavioural changes in patients with epilepsy through different pathways and are directly responsible for the clinical phenomenon of ‘forced normalization’ (‘alternative psychosis’).
Phenobarbital and primidone
Authors: Cavanna Andrea E.
Published: June 2018

Phenobarbital and primidone are first-generation antiepileptic drugs currently associated with restricted ranges of antiepileptic indications, despite their acceptable interaction profiles in polytherapy. Although phenobarbital is still widely prescribed as antiepileptic drug in the developing world, safety issues (including risks of dependence and overdose), together with the development of other antiepileptic drugs throughout the second half of the twentieth century, left little room for the use of barbiturates in patients with epilepsy. Both phenobarbital and primidone are barbiturates with an acceptable behavioural tolerability profile, but there are no approved indications or clinical uses for the treatment of behavioural symptoms in patients with psychiatric disorders.
Zonisamide
Authors: Cavanna Andrea E.
Published: June 2018

Zonisamide is a second-generation antiepileptic drug characterized by a few antiepileptic indications, with an acceptable interaction profile in polytherapy. Zonisamide has an acceptable tolerability profile in patients with epilepsy, with depression, irritability, agitation and psychosis as the most commonly reported psychiatric adverse effects. Zonisamide has no approved indications or clinical uses in psychiatry, as initial findings from uncontrolled studies suggesting effectiveness in the treatment of patients with bipolar disorder did not find confirmation. There is preliminary evidence for possible usefulness of zonisamide in the treatment of patients with obesity and psychotropic-associated weight gain, as well as alcohol dependence and withdrawal.
Thoracic Disc Disease
Authors: Dave Ankur P.
Published: June 2018

This chapter discusses thoracic disc disease (TDD), an overlooked condition affecting many chronic pain patients. TDD is rare and often misdiagnosed as cervical or lumbar disc disease. Given the various causes for mid-back pain, a thorough understanding of TDD is vital for the appropriate management of this patient population. This section will discuss the pathophysiology, clinical presentation, diagnostic evaluation (including imaging techniques), and treatment options for this condition. The chapter emphasizes the importance of considering TDD in the differential diagnosis for patients suffering from chronic mid-back pain.
Core Strengthening
Authors: Mehta Priyesh , Cormier David J. , Aueron Julie Ann , Singh Jaspal R.
Published: June 2018

Core strengthening remains a vital component of maintaining spine mechanics and assists in the prevention of injury. A complex group of muscles make up the core and function together to instill spine stability and assist with segmental motion. Understanding the key muscles and how they function is essential to developing a core strengthening program for patients with spinal pathology. This chapter summarizes the anatomy and biomechanics of the core involved in maintaining spine stability. It discusses electromyography and imaging data to help understand how these muscles function during specific exercises. Examples of core strengthening exercises are provided.